1,006 results on '"Ibrahim, Ahmed A."'
Search Results
2. Analyzing the influence of expanding multispecialty adoption of robotic surgery on robotic urologic care: A decade-long assessment of two Canadian academic hospitals.
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Ibrahim, Ahmed, Matta, Imad, Zakaria, Ahmed S., Khogeer, Abdulghani, Lee, Nick, Elseherbini, Tawfik, Nguyen, David-Dan, Corsi, Nicholas J., Bouhadana, David, Arezki, Adel, Chakraborty, Anindyo, Meskawi, Malek, Elhakim, Assaad, and Zorn, Kevin C.
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UROLOGY , *SURGICAL robots , *MEDICAL specialties & specialists , *ACADEMIC medical centers , *RADICAL prostatectomy , *TREATMENT effectiveness , *RETROSPECTIVE studies , *DESCRIPTIVE statistics , *RESEARCH , *DATA analysis software , *TIME ,SURGERY practice - Abstract
INTRODUCTION: Most robot-assisted surgery (RAS) systems in Canada are donor-funded, with constraints on implementation and access due to significant costs, among other factors. Herein, we evaluated the impact of the growing multispecialty use of RAS on urologic RAS access and outcomes in the past decade. METHODS: We conducted a retrospective review of all RAS performed by different surgical specialties in two high-volume academic hospitals between 2010 and 2019 (prior to the COVID pandemic). The assessed outcomes included the effect of increased robot access over the years on annual robotic-assisted radical prostatectomy (RARP) volumes, surgical waiting times (SWT), and pathologically positive surgical margins (PSM). Data were collected and analyzed from the robotic system and hospital databases. RESULTS: In total, six specialties (urology, gynecology, general, cardiac, thoracic, and otorhinolaryngologic surgery) were included over the study period. RAS access by specialty doubled since 2010 (from three to six). The number of active robotic surgeons tripled from seven surgeons in 2010 to 20 surgeons in 2019. Moreover, there was a significant drop in average case volume, from a peak of 40 cases in 2014 to 25 cases in 2019 (p=0.02). RARP annual case volume followed a similar pattern, reaching a maximum of 166 cases in 2014, then declining to 137 cases in 2019. The mean SWT was substantially increased from 52 days in 2014 to 73 days in 2019; however, PSM rates were not affected by the reduction in surgical volumes (p<0.05). CONCLUSIONS: Over the last decade, RAS access by specialty has increased at two Canadian academic centers due to growing multispecialty use. As there was a fixed, single-robotic system at each of the hospital centers, there was a substantial reduction in the number of RAS performed per surgeon over time, as well as a gradual increase in the SWT. The current low number of available robots and unsustainable funding resources may hinder universal patient access to RAS. [ABSTRACT FROM AUTHOR]
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- 2024
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3. Impact of pH modification of the empirically used tobramycin ophthalmic solution on MIC90 concentration in tears and aqueous humor of donkeys (Equus asinus).
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Ibrahim, Ahmed, Abd-Elrasoul, Mohamed A. A., and Sabra, Mahmoud S.
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DONKEYS , *OPHTHALMIC drugs , *AQUEOUS humor , *TOBRAMYCIN , *EQUUS , *DRUG bioavailability , *TOPICAL drug administration - Abstract
Background: Commercial tobramycin ophthalmic solution is frequently used empirically to treat ocular disorders in equines, despite being primarily formulated for use in humans. It has been noted that tobramycin MIC90 concentration (minimal inhibitory concentration to 90% of microbial growth) rapidly declined following topical administration. It is hypothesized that adjustment of the pH of the empirically used tobramycin ophthalmic solution -prepared for human use- with the pH of the tears of donkeys, could increase the bioavailability of the drug and subsequently improve its penetration to the aqueous humor. Therefore, this study aimed to evaluate the impact of pH adjustment of the empirically used tobramycin ophthalmic solution on MIC90 concentration in tears and aqueous humor of donkeys (Equus asinus). The study was conducted on six (n = 6) clinically healthy donkeys. In each donkey, one eye was randomly selected to receive 210 µg tobramycin of the commercial tobramycin (CT) and used as a positive control (C group, n = 6). The other eye (treated eye) received 210 µg of the modified tobramycin ophthalmic solution (MT) (T group, n = 6). Tears and aqueous humor samples were collected 5-, 10-, 15-, 30- min, and 1-, 2-, 4-, and 6 h post-instillation. Results: Modifying the pH of the empirically used commercial tobramycin ophthalmic solution in donkeys at a pH of 8.26 enhanced the drug's bioavailability. The MIC90 of the most hazardous bacteria isolated from equines' eyes such as Pseudomonas aeruginosa (MIC90 = 128 µg/ml) and Staphylococcus aureus (MIC90 = 256 µg/ml) was covered early (5 min post-instillation) and over a longer period in donkey tears (239–342 min) and aqueous humor (238–330 min) with the modified tobramycin solution. Conclusions: Adjustment of the pH of the commercial tobramycin ophthalmic solution, empirically used by veterinarians to treat donkeys' ophthalmic infections at a pH of 8.26, isotonic with the donkeys' tears pH, resulting in higher concentrations of tobramycin in tears and aqueous humor for a longer time. [ABSTRACT FROM AUTHOR]
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- 2024
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4. Mild Solutions for w -Weighted, Φ-Hilfer, Non-Instantaneous, Impulsive, w -Weighted, Fractional, Semilinear Differential Inclusions of Order μ ∈ (1, 2) in Banach Spaces.
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Alsheekhhussain, Zainab, Ibrahim, Ahmed Gamal, Al-Sawalha, M. Mossa, and Rashedi, Khudhayr A.
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The aim of this work is to obtain novel and interesting results for mild solutions to a semilinear differential inclusion involving a w-weighted, Φ -Hilfer, fractional derivative of order μ ∈ (1 , 2) with non-instantaneous impulses in Banach spaces with infinite dimensions when the linear term is the infinitesimal generator of a strongly continuous cosine family and the nonlinear term is a multi-valued function. First, we determine the formula of the mild solution function for the considered semilinear differential inclusion. Then, we give sufficient conditions to ensure that the mild solution set is not empty or compact. The desired results are achieved by using the properties of both the w-weighted Φ -Laplace transform, w-weighted ψ -convolution and the measure of non-compactness. Since the operator, the w-weighted Φ -Hilfer, includes well-known types of fractional differential operators, our results generalize several recent results in the literature. Moreover, our results are novel because no one has previously studied these types of semilinear differential inclusions. Finally, we give an illustrative example that supports our theoretical results. [ABSTRACT FROM AUTHOR]
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- 2024
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5. Synthesis of Bitter gourd-shaped Cu-doped ZnO nanostructures and their investigation for the detection of NO2 gas at low concentrations.
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Umar, Ahmad, Ibrahim, Ahmed A., Begi, Amensisa Negasa, Alhamami, Mohsen A.M., Almehbad, Noura, Hussain, Shahid, and Akbar, Sheikh
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ZINC oxide , *SCANNING electron microscopes , *GAS detectors , *NANOSTRUCTURES , *MOMORDICA charantia , *NITROGEN dioxide - Abstract
Nitrogen dioxide (NO 2) exposure can have several adverse health impacts on people, especially the respiratory system. Low selectivity, a lack of long-term stability, and structural and morphological optimization are some challenges associated with using ZnO for NO 2 gas sensing. Therefore, we intended copper (Cu) doping in ZnO to alter its shape and gas-sensing characteristics. This study explores the synthesis, properties, and gas-sensing capabilities of bitter gourd-shaped Cu-doped zinc oxide (ZnO) nanostructures for the detection of nitrogen dioxide (NO 2). A facile hydrothermal synthesis method was employed to synthesize bitter gourd-shaped Cu-doped ZnO nanostructures and comprehensively characterized by several techniques. Comprehensive characterizations of our produced Cu-doped ZnO nanomaterial demonstrated by X-ray diffraction (XRD), Scanning electron microscope (SEM), Energy-dispersive X-ray spectroscopy (EDS), and different energy spectrum. The material was annealed at 400 °C in a controlled dry air environment to improve its suitability for gas sensor applications. A series of temperature-ranging experiments were conducted to get gas-sensing readings from 25 °C to 300 °C. The resulting sensor, founded upon the distinctive morphology of Cu-doped ZnO structures reminiscent of the intricate shape of bitter gourd, unveiled good selectivity with a pronounced affinity for detecting NO 2 gas. Notably, the zenith of its performance was attained at an operating temperature of 200 °C, where its selectivity and sensitivity were most pronounced. Even at a low concentration of 1 ppm, the sensors displayed a maximum response of 3.7, highlighting their high sensitivity. The sensors demonstrated excellent reproducibility, selectivity, and a low detection limit. These findings position bitter gourd-shaped Cu-doped ZnO nanostructures as promising candidates for NO 2 sensing applications across diverse environments. [ABSTRACT FROM AUTHOR]
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- 2024
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6. The Frequency, Predictors and Health Impact of Post-Stroke Extrapyramidal Disorders (Clinical and Epidemiological Study).
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Al Fawal, Bastawy M., Ibrahim, Ahmed K., Saber, Mostafa, El Hamed, Mohamed Abd, and Tawfik, Ahmed Mamdouh
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EXTRAPYRAMIDAL disorders , *DISEASE risk factors , *BARTHEL Index , *STROKE patients , *BRAIN damage - Abstract
Background: Post-stroke extrapyramidal disorders (PSEDs) significantly impair functional outcomes but remain poorly characterized in stroke populations. Understanding the frequency, risk factors, and health impacts of PSEDs is essential for improving stroke management and rehabilitation strategies. Objective: To assess the incidence, risk variables, and impact of post-stroke extrapyramidal illnesses on functional outcome in a hospital-based population. Patients and Methods: This nested case-control study was conducted from October 2017 to September 2020. Among 1,971 acute cerebrovascular stroke patients screened, 167 met the inclusion criteria, divided into 69 cases with PSEDs and 98 controls without. Extensive neurological exams, brain imaging, and the Abnormal Involuntary Movement Scale (AIMS) were utilized to diagnose PSEDs. Risk factors were analyzed using logistic regression in IBM SPSS 21.0. Results: PSEDs developed in 3.5% of the stroke patients. Significant risk factors included older age (OR = 1.067, 95% CI: 1.037-1.097), diabetes mellitus (OR = 4.476, 95% CI: 1.987-8.083), and deep lesion site (OR = 3.477, 95% CI: 1.683-7.184). Patients with PSEDs were more likely to exhibit dementia (47.8% vs. 19.4%, P = 0.006) and had worse functional outcomes as measured by the Barthel Index (82.6% with poor outcomes vs. 61.2% in controls, P = 0.003). Conclusion: Post-stroke extrapyramidal disorders are associated with significant functional impairment and are more likely in patients with specific risk factors such as advanced age, diabetes, and deep brain lesions. Early identification and tailored management of these risk factors may improve outcomes in stroke patients at risk of PSEDs. [ABSTRACT FROM AUTHOR]
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- 2024
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7. Debye Temperature Evaluation for Secondary Battery Cathode of α-Sn x Fe 1− x OOH Nanoparticles Derived from the 57 Fe- and 119 Sn-Mössbauer Spectra.
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Ibrahim, Ahmed, Tani, Kaoru, Hashi, Kanae, Zhang, Bofan, Homonnay, Zoltán, Kuzmann, Ernő, Bafti, Arijeta, Pavić, Luka, Krehula, Stjepko, Marciuš, Marijan, and Kubuki, Shiro
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DEBYE temperatures , *STORAGE batteries , *CATHODES , *CHEMICAL bonds , *POLARONS , *ELECTRON transport , *SUPERPARAMAGNETIC materials - Abstract
Debye temperatures of α-SnxFe1−xOOH nanoparticles (x = 0, 0.05, 0.10, 0.15 and 0.20, abbreviated as Sn100x NPs) prepared by hydrothermal reaction were estimated with 57Fe- and 119Sn-Mössbauer spectra measured by varying the temperature from 20 to 300 K. Electrical properties were studied by solid-state impedance spectroscopy (SS-IS). Together, the charge–discharge capacity of Li- and Na-ion batteries containing Sn100x NPs as a cathode were evaluated. 57Fe-Mössbauer spectra of Sn10, Sn15, and Sn20 measured at 300 K showed only one doublet due to the superparamagnetic doublet, while the doublet decomposed into a sextet due to goethite at the temperature below 50 K for Sn 10, 200 K for Sn15, and 100 K for Sn20. These results suggest that Sn10, Sn15 and Sn20 had smaller particles than Sn0. On the other hand, 20 K 119Sn-Mössbauer spectra of Sn15 were composed of a paramagnetic doublet with an isomer shift (δ) of 0.24 mm s−1 and quadrupole splitting (∆) of 3.52 mm s−1. These values were larger than those of Sn10 (δ: 0.08 mm s−1, ∆: 0.00 mm s−1) and Sn20 (δ: 0.10 mm s−1, ∆: 0.00 mm s−1), suggesting that the SnIV-O chemical bond is shorter and the distortion of octahedral SnO6 is larger in Sn15 than in Sn10 and Sn20 due to the increase in the covalency and polarization of the SnIV-O chemical bond. Debye temperatures determined from 57Fe-Mössbauer spectra measured at the low temperature were 210 K, 228 K, and 250 K for Sn10, Sn15, and Sn20, while that of α-Fe2O3 was 324 K. Similarly, the Debye temperature of 199, 251, and 269 K for Sn10, Sn15, and Sn20 were estimated from the temperature-dependent 119Sn-Mössbauer spectra, which were significantly smaller than that of BaSnO3 (=658 K) and SnO2 (=382 K). These results suggest that Fe and Sn are a weakly bound lattice in goethite NPs with low crystallinity. Modification of NPs and addition of Sn has a positive effect, resulting in an increase in DC conductivity of almost 5 orders of magnitude, from a σDC value of 9.37 × 10−7 (Ω cm)−1 for pure goethite Sn (Sn0) up to DC plateau for samples containing 0.15 and 0.20 Sn (Sn15 and Sn20) with a DC value of ~4 × 10−7 (Ω cm)−1 @423 K. This non-linear conductivity pattern and levelling at a higher Sn content suggests that structural modifications have a notable impact on electron transport, which is primarily governed by the thermally activated via three-dimensional hopping of small polarons (SPH). Measurements of SIB performance, including the Sn100x cathode under a current density of 50 mA g−1, showed initial capacities of 81 and 85 mAh g−1 for Sn0 and Sn15, which were larger than the others. The large initial capacities were measured at a current density of 5 mA g−1 found at 170 and 182 mAh g−1 for Sn15 and Sn20, respectively. It is concluded that tin-goethite NPs are an excellent material for a secondary battery cathode and that Sn15 is the best cathode among the studied Sn100x NPs. [ABSTRACT FROM AUTHOR]
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- 2024
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8. Role of Fluorine 18 Fluorodeoxy-Glucose (FDG) Positron Emission Tomography (PET)/ Computed Tomography (CT) in Evaluation of Lymphoma Patients.
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Mohamed Ibrahim, Ahmed Ibrahim, Salem, Ahmed Ferky, El-Sammak, Ahmed Abdel-Aziz, and Besar, Awad AbdelAziz
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POSITRON emission tomography , *COMPUTED tomography , *HODGKIN'S disease , *NON-Hodgkin's lymphoma , *LYMPHOMAS - Abstract
Background: Malignant lymphoma is considered the most common hematological malignancy. Lymphoma is divided into Hodgkin’s disease and non-Hodgkin’s lymphoma. Non-Hodgkin’s lymphoma forms most cases with more affinity to involve extra-nodal sites. The objective of the study was to highlight the role of 18F-FDG Positron Emission Tomography (PET)/ Computed tomography (CT) in evaluation & follow up of cases of Lymphoma. Methods: This prospective study was performed at Nasser Institute for research and treatment Hospital from January-2021 to January-2022 for staging and therapeutic assessment of lymphoma. Biopsy results were the gold standard, which compared with CT and PET results. Results: Out of 48 cases in our study came for initial staging, assessment of treatment and follow up. PET/CT showed the same results as CT in 28 cases with no changes, while 20 cases showed discordant results with CT, mostly showing changes in FDG uptake of previously noted lesion in follow up patients, which was statistically significant. PET-CT detected additional extra nodal involvement than CT in 15 cases as: 6 cases splenic infiltration, 3 bone marrow and musculoskeletal, 2 hepatic, 1 gastric, 1 nasal, 1 CNS and 1 breast. Conclusions: The present findings revealed the significance of 18F-FDG PET/CT as a potential method in lymphoma initial staging. PET/CT had remarkable indications in evaluation of treatment feedback as compared to conventional CT. PET/CT is highly specific and permits definite localization of remanent masses and detects active tumor within residual mass. PET/CT was also helpful in detection of early relapsing lymphomas in both HD and NHL. [ABSTRACT FROM AUTHOR]
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- 2024
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9. Boosting the hydrophobicity of eco‐friendly polyaniline coating using TiO2 and ZnO nanoparticles.
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Gomaa, Mona H., Ibrahim, Ahmed, El‐Sayed, Kh., and Hamid, Z. Abdel
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SCANNING transmission electron microscopy , *FOURIER transform infrared spectroscopy , *POLYANILINES , *X-ray photoelectron spectroscopy , *ATOMIC force microscopes , *ZINC oxide films , *INDIUM oxide - Abstract
This article clarifies the thin layer deposition of superhydrophobic coating using eco‐friendly polymer (polyaniline [PANI]) incorporated with TiO2 and ZnO nanoparticles on indium tin oxide substrate. Using the cyclic voltammetry method, in situ polymerization of PANI incorporated with hybrid (TiO2–ZnO) was accomplished. The morphology and hydrophobicity of electro‐deposited films were examined; the impact of deposition cycles was also investigated. The morphological structure was studied using field‐emission scanning electron microscopy and high‐resolution transmission electron microscopy. X‐ray photoelectron spectroscopy and Fourier transform infrared spectroscopy analysis proved the incorporation of nanoparticles into the composite matrix. Additionally, the water contact angle of the PANI composite was found to be 150.4°, and the findings reflected that (TiO2–ZnO) nanoparticles were significantly implicated in enhancing this superhydrophobicity. The surface roughness of the PANI matrix was increased when TiO2 and ZnO are added, as was shown by atomic force microscope investigation. [ABSTRACT FROM AUTHOR]
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- 2024
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10. Development of a chitosan derivative bearing the thiadiazole moiety and evaluation of its antifungal and larvicidal efficacy.
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Ibrahim, Ahmed G., Elgammal, Walid E., Hashem, Amr H., Mohamed, Ahmad E., Awad, Mohmed A., and Hassan, Saber M.
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THIADIAZOLES , *ANTIFUNGAL agents , *CHITOSAN , *FOURIER transform infrared spectroscopy , *X-ray photoelectron spectroscopy , *GAS chromatography/Mass spectrometry (GC-MS) , *MOIETIES (Chemistry) - Abstract
A new chitosan derivative bearing a new thiadiazole compound was developed, and its antifungal and larvicidal activities were investigated. The chitosan derivative (coded here as PTDz-Cs) was synthesized by the reaction between the carboxylic derivative of the thiadiazole moiety and chitosan. Fourier transform infrared spectroscopy (FT-IR), nuclear magnetic resonance (1H/13C-NMR), gas chromatography–mass spectrometry (GC–MS), elemental analysis, X-Ray diffraction (XRD), thermogravimetric analysis (TGA), and X-ray photoelectron spectroscopy (XPS) were used to characterize the developed derivatives. Compared to chitosan, the PTDz-Cs derivative has a less crystalline structure and less thermal stability. The antifungal results revealed that PTDz-Cs exhibited potential activity against Rhizopus microspores, Mucor racemosus, Lichtheimia corymbifera, and Syncephalastrum racemosum where inhibition zones were 17.76, 20.1, 38.2, and 18.3 mm, respectively. The larvicidal efficacy of the PTDz-Cs derivative against A. stephensi larvae was tested, and the results exposed that the LC50 and LC90 values (first instar) were 5.432 and 10.398 ppm, respectively, indicating the high susceptibility of early instar mosquito larvae to PTDz-Cs. These results emphasize that this study provided a new chitosan derivative that could be potentially used in the biomedical fields. [ABSTRACT FROM AUTHOR]
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- 2024
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11. Investigation of the electrochemical behavior of a newly designed TiMg dental implant.
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Ibrahim, Ahmed Mohamed Hassan and Balog, Martin
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DENTAL implants , *PHYSIOLOGIC salines , *ELECTROLYTIC corrosion , *OPEN-circuit voltage , *SCANNING electron microscopes , *X-ray spectrometers , *OSSEOINTEGRATION - Abstract
This study is aimed to evaluate the galvanic corrosion of a newly designed TiMg dental implant. The TiMg composite was tested in two forms: (1) cylinders (TiMg cyl) and (2) dental implants (TiMg DI). Surface roughness was measured using a confocal microscope. The electrochemical behavior was determined in a Hank's balanced salt solution (HBSS) by the open-circuit potential (OCP), potentiodynamic polarization (PDP), and electrochemical impedance spectroscopy (EIS) measurements. Surfaces after corrosion were examined by a scanning electron microscope (SEM) equipped with an energy-dispersive X-ray spectrometer (EDS). OCP of TiMg cyl and TiMg DI increased in the noble direction, indicating the formation and growth of a base film on their surfaces. After 2-h immersion, TiMg cyl had higher values of iCorr and RCorr compared with those of TiMg DI. After 24-h immersion, a prominent reduction in the values of iCorr and RCorr was observed, and ECorr shifted positively. The Nyquist plots of TiMg cyl and TiMg DI show capacitive loops that tended to close after 2-h exposure. As the time extended, TiMg DI showed higher corrosion resistance compared with that of TiMg cyl, and the linear diffusion response arose from the formation and dissolution of chemically non-stable by-products caused by the hydrogen evolution. In such a case, the involved reaction was controlled by charge transfer and diffusion processes. The formation of a film composed of stable CAp species that attached directly to the surface and chemically non-stable by-products that included (Mg3(PO4)2) and Mg(OH)2 was demonstrated. To conclude, the obtained results revealed that TiMg DI of a complicated threaded design had a more stable passive film and higher corrosion resistance in HBSS compared with those of TiMg cyl of a cylindrical design. These findings have the utmost importance for the fabrication of dental implants. [ABSTRACT FROM AUTHOR]
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- 2024
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12. New strategies for sterilization and preservation of fresh fish skin grafts.
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Ibrahim, Ahmed, Fahmy, Hossam M., Mahmoud, Ghada Abd-Elmonsef, Soliman, Mahmoud, and Elshahawy, Abdelnaby M.
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FISH skin , *SKIN grafting , *BIOLOGICAL dressings , *AEROBIC bacteria , *INFECTIOUS disease transmission - Abstract
The introduction of fish skin as a biological dressing for treating burns and wounds holds great promise, offering an alternative to existing management strategies. However, the risk of disease transmission is a significant concern. Therefore, this study aimed to examine how established sterilization and preservation procedures affected fish skin grafts' microbiological and histological properties for long-term usage. Lyophilization of the fish skin graft followed by rehydration in normal saline for 15 min did not change the collagen content. Furthermore, gamma irradiation of the lyophilized fish skin graft at different lengths 5, 10, and 25 KGy showed a significant reduction in microbial growth (aerobic bacteria, aerobic yeasts, and fungi) at 15- and 30 days after the irradiation. However, exposure to 10 KGy was found to be the most effective intensity among the different gamma irradiation lengths since it preserved the collagen fiber content and intensity in the lyophilized fish skin grafts at 15- and 30 days after the irradiation. These findings provide efficient preservation and sterilization methods for long-term usage of the fresh Tilapia skin grafts used for biological dressings. [ABSTRACT FROM AUTHOR]
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- 2024
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13. Ultrasound irradiation of hydrothermally engineered sub-20 nm PbS nanoparticles and effect of their size on Aspergillus species morphology.
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Mahmoud, Ghada Abd-Elmonsef and Ibrahim, Ahmed B.M.
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NANOPARTICLE size , *SURFACE area measurement , *LEAD sulfide , *TRANSMISSION electron microscopy , *X-ray powder diffraction - Abstract
[Display omitted] Lead sulfide nanoparticles were hydrothermally synthesized and their size was diminished via exposure to ultrasound waves. Both h -PbS and h , us -PbS nanoparticles of different sizes were characterized using powder X-ray diffraction, TEM microscopy and surface area measurements. The nanoparticles limited the growth of Aspergillus pathogens and light microscopy proved severe morphological abnormalities in the fungal vesicles, conidiophores and mycelia in response to the nanoparticles. [ABSTRACT FROM AUTHOR]
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- 2024
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14. Tailored Ni-MgO Catalysts: Unveiling Temperature-Driven Synergy in CH 4 -CO 2 Reforming.
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Alghamdi, Ahmad M., Ibrahim, Ahmed A., Ali, Fekri Abdulraqeb Ahmed, Bamatraf, Nouf A., Fakeeha, Anis H., Osman, Ahmed I., Alreshaidan, Salwa B., Fadhillah, Farid, Al-Zahrani, Salma A., and Al-Fatesh, Ahmed S.
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STEAM reforming , *NICKEL catalysts , *CATALYSTS , *CATALYTIC activity , *TRANSMISSION electron microscopes , *CATALYST supports , *SURFACE diffusion - Abstract
This study examines nickel catalysts on two different supports—magnesium oxide (MgO) and modified MgO (with 10 wt.% MOx; M = Ti, Zr, Al)—for their effectiveness in the dry reforming of methane. The reactions were conducted at 700 °C in a tubular microreactor. The study compares the best-performing catalyst with a reference catalyst (5Ni/MgO) by conducting dry reforming of methane at different reaction temperatures. The catalysts are evaluated using surface area, porosity, X-ray diffraction, infrared spectroscopy, transmission electron microscope, thermogravimeter, and temperature-programmed techniques. The 5Ni/MgO + ZrO2 catalyst demonstrates inferior catalytic activity due to insufficient active sites. On the other hand, the 5Ni/MgO + TiO2 catalyst shows limited catalytic excellence due to excessive coke deposits, which are six times higher than other catalysts. The 5Ni/MgO and 5Ni/MgO + Al2O3 catalysts have the richest basic and acidic profiles, respectively. The 5Ni/MgO + Al2O3 catalyst is superior to other catalysts due to its stronger metal–support interaction on the expanded surface and the efficient diffusion of carbon on its less crystalline surface. At 700 °C, this catalyst achieves 73% CH4 conversion, and at 800 °C, it reaches 83% conversion. This study emphasizes the crucial role of the reaction temperature in reducing carbon deposition and enhancing the efficiency of the reforming process. [ABSTRACT FROM AUTHOR]
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- 2024
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15. Extracting behavioural features from smartphone notifications.
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Ibrahim, Ahmed, Clinch, Sarah, and Harper, Simon
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SMARTPHONES , *BEHAVIOR , *MACHINE learning , *TASK performance , *CONCEPTUAL structures , *INSTANT messaging , *COMMUNICATION , *SHOPPING , *DESCRIPTIVE statistics , *LONGITUDINAL method , *PHENOTYPES - Abstract
A significant proportion of smartphone notifications are indicative of human behaviour (e.g. delivery updates for purchased items, physical activity summaries, and notification of updates to subscribed content). However, present attempts to understand human behaviour from smartphone traces typically focus on sensors such as location, accelerometer and proximity, overlooking the potential for notifications as a valuable data source. In this paper, we propose a general framework that provides end-to-end processing of notifications to understand behavioural aspects. We realise the framework with an implementation that tackles the specific use case of establishing prior buying behaviour from associated notifications. To evaluate the framework and implementation, we conduct a longitudinal user study in which we collect more than 250, 000 notifications, from twelve users, over an average of three months. We apply knowledge-based and machine learning techniques to those notifications to assess the tasks of the proposed framework. The results show a substantial difference in the performance between the methods used to extract behavioural features from the collected notifications. [ABSTRACT FROM AUTHOR]
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- 2023
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16. Evolution of Polymorphs in Rhopalosiphum maidis (Hemiptera: Aphididae) in Response to Different Seasonal and Host Plant Conditions.
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Ibrahim, Ahmed M. A., Rasmey, Nourelhoda M., Abdelrahman, Mohamed A., Hassan, Mohamed H. A., and Ali, Ali M.
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RHOPALOSIPHUM , *HOST plants , *APHIDS , *HEMIPTERA , *CYTOCHROME oxidase , *SORGHUM - Abstract
The aphid Rhopalosiphum maidis is a serious pest against cereal plants. In Egypt, it causes serious damage to many cereal plants. The principal idea of this study was achieved based on the observation of various seasonal invasion rates of this pest on different host plants suggesting climatic adaptation by R. maidis polymorphs. The invasion rates on winter plants were higher than those of summer. Morphologically, all collections were belonging to R. maidis. The authors assumed that different biotypes of R. maidis are present in the studied area. To address this hypothesis, the mitochondrial cytochrome oxidase I (COI) gene was amplified in aphids collected from wheat, barley, sorghum and maize in Assiut, Egypt. Polymerase chain reactions (PCR) identified 687 bps products corresponding to a partial sequence of (COI). Multiple sequence alignment of the sequenced products revealed that at least five haplotypes are present on the tested plants. Phylogenetic analysis using the neighbor-joining method identified five clades that represent different biotypes. The identified clades contained mixtures between summer and winter R. maidis collections suggesting that different biotypes are present in mixtures on the same plant. Our findings showed that R. maidis develops different polymorphs on various host plants at different climatic conditions. [ABSTRACT FROM AUTHOR]
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- 2023
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17. Chronic effects induced by zinc oxide nanoparticles against larvae of the northern house mosquito Culex pipiens (Diptera: Culicidae).
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Ibrahim, Ahmed M. A., Alfuhaid, Nawal Abdulaziz, Thabet, Marwa Adel, and Ali, Ali Mohamed
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CULEX pipiens , *INSECTICIDES , *MOSQUITOES , *ZINC oxide , *DIPTERA , *LARVAE , *ALIMENTARY canal - Abstract
It is estimated that up to a million person are subject to death every year from mosquito-borne diseases. To avoid the epidemic situations arising from mosquito-borne diseases, it is necessary to reduce the mosquito populations. Challenges against efficient mosquito management are mainly related to emergence of insecticide resistance leading to increased need for the development of alternative methods. Ideal insecticides cause permanent impacts on the target insects in order to ensure powerful insecticidal effect. This study hypothesized that the impact of zinc oxide nanoparticles (ZnONPs) on the larvae of Culex pipiens Linnaeus, 1758 (Diptera: Culicidae) mosquito is irreversible and chronic. The first instar C. pipiens larvae were treated with a sublethal concentration (LC20, 0.24 g/L) of ZnONPs for 72 h and then allowed to recover for additional 72 h. Following the recovery period, the changes in zinc accumulation, growth rate, gut ultrastructure, biochemical changes in the hydrogen peroxide, antioxidant and detoxification enzymes were recorded and compared between recovered larvae and untreated (control). Recovered larvae showed significant increase in the accumulated zinc and reduced growth rate by about 50% compared to untreated (control). Furthermore, the ultrastructure of the alimentary canal epithelium showed several forms of pathological signs in different parts of the midgut of recovered larvae. Treatment with ZnONPs induced oxidative stress (OS) which appeared in the form of significant increase in hydrogen peroxide concentration. In response to OS, insects activate the detoxification system to get rid of the toxic nanoparticles. The detoxification enzyme alkaline phosphatase (ALP) and the antioxidant enzyme glutathione peroxidase (GPX) were inhibited while superoxide dismutase (SOD) was activated against ZnONPs toxicity. Additionally, recovered larvae didn't show differences in the catalase activity from untreated control. These results verified that ZnONPs induce chronic impacts on C. pipiens larvae suggesting that it can be used in their management via direct application in standing water sources including accumulated rains and swimming pools. [ABSTRACT FROM AUTHOR]
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- 2023
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18. Promotion impact of different strontium doping on Ni‐9La+Zr catalyst for dry reforming of methane.
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Ibrahim, Ahmed A., Al‐Fatesh, Ahmed S., Alwadai, Norah, Al‐Zahrani, Salma A., Abu‐Dahrieh, Jehad K., Abasaeed, Ahmed E., and Fakeeha, Anis H.
- Subjects
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STEAM reforming , *METHANE , *MATERIALS texture , *CATALYSTS , *STRONTIUM , *TUBULAR reactors , *CARBON dioxide , *NICKEL catalysts - Abstract
The potential dry reforming of methane technology allows for the synthesis of syngas from methane and carbon dioxide. Numerous investigations have been conducted on developing catalysts with exceptional activity and stability. Carbon deposition causes severe deactivation in typical nickel‐based catalysts, which is one of the most prevalent and important problems. In this study, methane was dry‐reformed over 5 wt.% Ni+xSr‐9La+Zr (x = 0–4 wt.%) catalysts for 7.5 h at 700°C and ambient pressure in a tubular fixed‐bed reactor. According to the weight percent of Sr loading, the features of the material's texture, morphology, and catalysis were investigated. N2‐physisorption, H2‐temperature programmed reduction, X‐ray diffraction, Raman, and TEM were used to evaluate the physicochemical characteristics of the catalysts. N2‐physisorption research revealed that changing the weight percentage loading of the Sr promoter had little effect on the textural qualities. The overall number of reducible NiO‐interacting species over the catalyst surface increased with increasing Sr loading. The 5Ni+2Sr‐9La+Zr catalyst exhibited the optimum CH4 and CO2 conversions of 62.9%–65.9% and 69.1%–70.3%, respectively, and the lowest deactivation factor of 4.7. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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19. The Effectiveness of Ni-Based Bimetallic Catalysts Supported by MgO-Modified Alumina in Dry Methane Reforming.
- Author
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Ibrahim, Ahmed A., Fakeeha, Anis H., Abasaeed, Ahmed E., Wazeer, Irfan, Bentalib, Abdulaziz, Siva Kumar, Nadavala, Abu-Dahrieh, Jehad K., and Al-Fatesh, Ahmed S.
- Subjects
- *
BIMETALLIC catalysts , *CATALYST supports , *ALUMINUM oxide , *METHANE , *CARBON dioxide , *RAMAN spectroscopy - Abstract
Syngas is produced through the carbon dioxide reforming of methane. The traditional nickel-based catalysts are substantially destroyed by carbon deposition. The reforming reaction was conducted in a tubular microreactor at 700 °C using bimetallic Ni catalysts supported over 37% Al2O3 and 63% MgO mixtures. The impregnation process formed the catalysts, which were subsequently examined by N2-physisorption, XRD, H2-TPR, TGA, and Raman spectroscopy. The 2.5Ni+2.5Co/37%Al2O3+63%MgO bimetallic catalyst, which displayed 72% and 76% conversions of CH4 and CO2 over the course of a seven-hour procedure, was discovered to be the most active in DRM. The bimetallic catalyst with the largest weight loss in TGA, 2.5Ni+2.5Fe-MG63, had a loss of 61.3%, a difference of 26% and 21% in the activity performance of CH4 and CO2, respectively, of the tested bimetallic Ni catalysts was recorded. The long-time of 30 h on-stream CH4 and CO2 conversion reactions for 2.5Ni+2.5Co-MG63 and 2.5Ni+2.5Ce-MG63 catalysts showed the catalysts' high stability. The TPO analysis for the 2.5Ni+2.5Cs-MG63 catalyst showed a peak at 650 °C, attributed to the oxidation of the filamentous carbon, whereas the TPO analysis for the 2.5Ni+2.5Co-MG63 catalyst depicted a peak at 540 °C, ascribed to the presence of amorphous/graphite carbon. [ABSTRACT FROM AUTHOR]
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- 2023
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20. Photoelectric factor prediction using automated learning and uncertainty quantification.
- Author
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Alsamadony, Khalid, Ibrahim, Ahmed Farid, Elkatatny, Salaheldin, and Abdulraheem, Abdulazeez
- Subjects
- *
MACHINE learning , *KRIGING , *PHOTOELECTRICITY , *ATOMIC number , *FRICTION velocity , *RESERVOIR rocks , *GAMMA rays - Abstract
The photoelectric factor (PEF) is an important well-logging tool to distinguish between different types of reservoir rocks because PEF measurement is sensitive to elements with high atomic numbers. Furthermore, the ratio of rock minerals could be determined by combining PEF log with other well logs. However, PEF logs could be missing in some cases such as in old well logs and wells drilled with barite-based mud. Therefore, developing models for estimating missing PEF logs is essential in those circumstances. In this work, we developed various machine learning models to predict PEF values using the following well logs as inputs: bulk density (RHOB), neutron porosity (NPHI), gamma ray (GR), compressional and shear velocity. The predictions of PEF values using adaptive-network-fuzzy inference system (ANFIS) and artificial neural network (ANN) models have errors of about 16% and 14% average absolute percentage error (AAPE) in the testing dataset, respectively. Thus, a different approach was proposed that is based on the concept of automated machine learning. It works by automatically searching for the optimal model type and optimizes its hyperparameters for the dataset under investigation. This approach selected a Gaussian process regression (GPR) model for the accurate estimation of PEF values. The developed GPR model decreases the AAPE of the predicted PEF values in the testing dataset to about 10% AAPE. This error could be further decreased to about 2% by modeling the potential noise in the measurements using the GPR model. [ABSTRACT FROM AUTHOR]
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- 2023
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21. Factors Affecting Callus Induction from Anther and Ovary of Okra (Abelmoschus esculentus L.).
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Ibrahim, Ahmed Mahmood, Abbas, Ali Razzaq, Aldabbagh, Ehab Jabbar, and Mohammed, Arifullah
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OKRA , *PLANT breeding , *CALLUS , *ANTHER , *INDOLEACETIC acid , *PLANT regulators , *TISSUE culture - Abstract
Background: Okra [Abelmoschus esculentus (L.) Moench.] is a nutrient-rich vegetable crop widely grown in the tropics and subtropics mainly for its edible pods. The haploid technique has been used in plant breeding for the improvements of plants and to develop new varieties in relatively a short time. Hence, we have optimized several factors such as plant growth regulators (PGR), sucrose concentration, cold treatment, type of media and culture conditions for callus induction from the anther and ovary of okra (557 F1 hybrid). Methods: The flower buds of different sizes were collected to determine various stages of development and then subjected to cold pretreatments. The explants were then cultured on various combinations of PGRs i.e., naphthyloxy acetic (NOA), Indole acetic acid (IAA), 2, 4-Dichlorophenoxy acetic acid (2, 4-D), Benzyl amino purine (BAP), isopentenyl adenine 2iP, Kinetin (KIN) and Thidiazuron (TDZ). Result: The optimum developmental stage of microspore for callus initiation was achieved from flower buds of okra and its size was about 11 mm long. Flower buds that emerged one week after the flowering showed significantly higher percentage of callus induction. The optimum stage for ovary and ovule culture were one or two days prior to anthesis and the flower buds stage was 35±1mm. In conclusion, our study investigated the effect of several factors that affects callus induction in okra and optimized cultured conditions for future haploid development for okra. [ABSTRACT FROM AUTHOR]
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- 2023
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22. Strontium‐promoted Ni/ZrO2–Al2O3 catalysts for dry reforming of methane.
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Al‐Fatesh, Ahmed S., Ibrahim, Ahmed A., Osman, Ahmed I., Abasaeed, Ahmed E., Alotibi, Mohammed F., Alfatesh, Sadeq A., Rooney, David W., Fakeeha, Anis H., and Yin, Chun‐Yang
- Subjects
- *
STEAM reforming , *LIQUID fuels , *TEMPERATURE-programmed reduction , *METHANE , *TRANSMISSION electron microscopy , *CATALYSTS - Abstract
Dry reforming of methane (DRM) is an established process that utilizes CH4 and CO2 to produce syngas, which is subsequently used to produce liquid fuel. Developing an optimized catalyst with favorable physicochemical properties is essential to enhance the effectiveness of the DRM process. In this study, we report novel findings on Ni/ZrO2 + Al2O3 catalyst performance promoted with strontium (Sr) for DRM reaction. The characteristics of fresh and spent catalysts were evaluated via a suite of analytical characterization techniques, including physisorption analysis, temperature‐programmed reduction, transmission electron microscopy, X‐ray diffractometry, Raman spectroscopy, temperature‐programmed desorption, temperature‐programmed oxidation, and thermogravimetric analysis before actual DRM performance analysis. The integration of Sr essentially enhanced the basicity, imparted CO2 adsorption stability, and improved the reducibility of the catalyst. An optimal concentration of 3.0 wt% Sr promoted on the catalyst afforded the highest CH4 and CO2 conversions. The work presented in this contribution affords an understanding of optimum Sr loading and provides insights into the synergistic role of Sr on catalytic performances as applied to the DRM process. [ABSTRACT FROM AUTHOR]
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- 2023
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23. Calculating of treatment plant efficiency by using the Canadian council of ministers of the environment water quality index.
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Ibrahim, Ahmed Khaleel and Ahmed, Salwa Hadi
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WATER quality , *ENVIRONMENTAL quality , *BIOCHEMICAL oxygen demand , *CHEMICAL oxygen demand - Abstract
This study included measures of the water quality index for wastewater in Aldujail district treatment plant before and after treatment using the Canadian Council of Ministers of the Environment water quality index (CCMEWQI) that depends on local conditions and issues. Eight properties versus eleven times before and after processing were used for calculating CCMEWQI. The plant efficiency was calculated by using the values obtained from the available data and the water quality index. The results showed a difference between the value of the water quality index before and after treatment, the value of CCMEWQI before treatment indicated that the water quality was poor, but it was marginal after treatment. The overall efficiency was 47.4% but it was different with respect to biochemical oxygen demand (BOD) and chemical oxygen demand (COD) during months of the year, as the maximum removal efficiency of (BOD) was 89% in November while the minimum removal efficiency value was 85% in June, but the maximum and minimum removal efficiency of (COD) was 86% and 79% in May and February respectively; the other characteristics did not show any significant changes in efficiency. [ABSTRACT FROM AUTHOR]
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- 2023
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24. Photocatalytic and Cathode Active Abilities of Ni-Substituted α-FeOOH Nanoparticles.
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Ibrahim, Ahmed, Shiraishi, Mikan, Homonnay, Zoltán, Krehula, Stjepko, Marciuš, Marijan, Bafti, Arijeta, Pavić, Luka, and Kubuki, Shiro
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FOURIER transform infrared spectroscopy , *SURFACE area measurement , *DIFFERENTIAL thermal analysis , *CATHODES , *REFLECTANCE spectroscopy , *MOSSBAUER spectroscopy , *LEAD-free ceramics - Abstract
The present study investigates the relationship between the local structure, photocatalytic ability, and cathode performances in sodium-ion batteries (SIBs) and lithium-ion batteries (LIBs) using Ni-substituted goethite nanoparticles (NixFe1−xOOH NPs) with a range of 'x' values from 0 to 0.5. The structural characterization was performed applying various techniques, including X-ray diffractometry (XRD); thermogravimetry differential thermal analysis (TG-DTA); Fourier transform infrared spectroscopy (FT-IR); X-ray absorption spectroscopy (XANES/EXAFS), both measured at room temperature (RT); 57Fe Mössbauer spectroscopy recorded at RT and low temperatures (LT) from 20 K to 300 K; Brunauer–Emmett–Teller surface area measurement (BET), and diffuse reflectance spectroscopy (DRS). In addition, the electrical properties of NixFe1−xOOH NPs were evaluated by solid-state impedance spectroscopy (SS-IS). XRD showed the presence of goethite as the only crystalline phase in prepared samples with x ≤ 0.20, and goethite and α-Ni(OH)2 in the samples with x > 0.20. The sample with x = 0.10 (Ni10) showed the highest photo-Fenton ability with a first-order rate constant value (k) of 15.8 × 10−3 min−1. The 57Fe Mössbauer spectrum of Ni0, measured at RT, displayed a sextet corresponding to goethite, with an isomer shift (δ) of 0.36 mm s−1 and a hyperfine magnetic distribution (Bhf) of 32.95 T. Moreover, the DC conductivity decreased from 5.52 × 10−10 to 5.30 × 10−12 (Ω cm)–1 with 'x' increasing from 0.10 to 0.50. Ni20 showed the highest initial discharge capacity of 223 mAh g−1, attributed to its largest specific surface area of 174.0 m2 g−1. In conclusion, NixFe1−xOOH NPs can be effectively utilized as visible-light-activated catalysts and active cathode materials in secondary batteries. [ABSTRACT FROM AUTHOR]
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- 2023
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25. PRODUCTIVE AND PHYSIOLOGICAL EFFECTS OF PROBIOTICS AND APPLE VINEGAR ON BROILER CHICKENS UNDER HIGH STOCKING DENSITY.
- Author
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Ibrahim, Ahmed A., Ahmed, Samir F., and Galal, Mahmoud S.
- Abstract
This study aimed to assess the effect of watery supplementation of probiotic and/or apple vinegar on productive and physiological performances of broiler chickens (Ross 308) reared under high stocking density. Three hundred thirty-six unsexed one-day-old broiler chicks were randomly distributed to eight different treatments (3 replicates each) as follow: T1: Negative control (low stocking density (LSD) 12 birds/m2 ; basal diet with no studied additives in drinking water), T2: LSD + probiotic, T3: LSD + apple vinegar, T4: LSD + probiotics + apple vinegar, T5: Positive control (high stocking density (HSD), 16 birds/m2 ; basal diet with no studied additives in drinking water), T6: HSD + Probiotics, T7: HSD + apple vinegar and T8: HSD + probiotics+ apple vinegar. Probiotic mixture or/and apple vinegar were provided at a dose of 0.5% in drinking water. The body weight (BW), body weight gain (BWG), feed intake (FI) and feed conversion ratio (FCR) were measured every growth phase until the end of the study at 35 day of age. Also 6 birds of each treatment were used to evaluate carcass traits. Results revealed that administration of probiotics individually or in combined with apple vinegar significantly increased BW, BWG and FI, with a decreased FCR at grower (21 days of age) phase and market age (35 days of age), while apple vinegar additive groups had the lowest BW, BWG and FI, with increased FCR in both tested stocking density. In addition, enhanced carcass yield, some carcass parts (breast and thigh), blood constituents and beneficial bacteria count in small intestine of broilers provided by additives suggested. In conclusion, this study proves valuable effects of probiotic and apple vinegar on growth performance, carcass traits, and microbiological measurements at grower and finisher phases of broilers raised under high stocking density. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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26. Frequency reconfigurable antipodal Vivaldi 2-port antenna based on graphene for terahertz communications.
- Author
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Ibrahim, Ahmed A. and Gaber, Shaymaa M.
- Subjects
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ANTENNAS (Electronics) , *FREQUENCY selective surfaces , *GRAPHENE , *CHEMICAL potential , *COPPER , *RADIATORS , *QUANTUM cascade lasers - Abstract
A graphene-based two ports antipodal Vivaldi antenna with improved gain for THz applications is introduced. The single antenna is composed of an antipodal Vivaldi antenna with a graphene radiator on the top and copper ground plane on the back with a total size equal to 108 µm × 84 µm to achieve reconfigurable performance from 3 to 4.5 THz. The reconfigurability is validated by changing the external DC Volt which in turn changes the graphene chemical potential and then changes the operating frequency. As well, to enhance the antenna gain, frequency selective surfaces (FSS) with a metallic patch are utilized to enhance the antenna gain. The FSS performance is investigated and optimized using a finite integral technique (FIT) software to achieve a reflective feature with band rejection from 2 up to 5 THz within the operating bands of the suggested antenna. The FSS is inserted below the MIMO antenna to reflect the antenna radiation and then enhance the antenna gain. The antenna gain is increased from 6 dB (single antenna without FSS) to 10.8 dB (with FSS) at 3.4 THz. The MIMO antenna is operated from 3.2 to 4.45 THz with S11 ≤ − 10 dB, isolation ˃ 20, gain from 8 to 10.8 dB, and efficiency higher than 80%. Finally, the MIMO parameters outcomes achieved good values which suggested the antenna to be employed in IoT THz applications. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
27. Impact of Green Human Resources Management Practices on Sustainable Development: Evidence from Ma'aden Company (Waadalshamal).
- Author
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Kilase, Mohamed and Ibrahim, Ahmed
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- 2023
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28. New Functionalized Chitosan with Thio-Thiadiazole Derivative with Enhanced Inhibition of Pathogenic Bacteria, Plant Threatening Fungi, and Improvement of Seed Germination.
- Author
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Ibrahim, Ahmed G., Elgammal, Walid E., Eid, Ahmed M., Alharbi, Maha, Mohamed, Ahmad E., Alayafi, Aisha A. M., Hassan, Saber M., and Fouda, Amr
- Subjects
- *
PHYTOPATHOGENIC fungi , *GERMINATION , *PLANT-fungus relationships , *CHITOSAN , *PATHOGENIC bacteria , *SEED treatment - Abstract
In this study, a new modified chitosan conjugate (Chito-TZ) was developed via amide coupling between the acid chloride derivative of the methylthio-thidiazole compound and the free primary amino groups of chitosan. The product was characterized using several instrumental investigations, including Fourier-transform infrared spectroscopy (FT-IR), 1H-Nuclear magnetic resonance, X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA), and X-ray diffraction (XRD). XRD indicated that the crystalline pattern of chitosan was interrupted after chemical modification with the thiadiazole derivative. Broido's model was used to determine the thermal activation energy Ea, and the results showed that the Ea for the first decomposition region of Chito-TZ is 24.70 KJ mol−1 lower than that required for chitosan (95.57 KJ mol−1), indicating the accelerating effect of the thiadiazole derivative on the thermal decomposition of Chito-TZ. The modified chitosan showed better antibacterial and antifungal activities than the non-modified chitosan; except for seed germination, chitosan was better. The Chito-TZ showed a low MIC value (25–50 µg mL−1) compared to Chito (50–100 µg mL−1). Moreover, the maximum inhibition percentages for plant-pathogenic fungi, Aspergillus niger, Fusarium oxysporum, and Fusarium solani, were attained at a concentration of 300 µg mL−1 with values of 35.4 ± 0.9–39.4 ± 1.7% for Chito and 45.2 ± 1.6–52.1 ± 1.3% for Chito-TZ. The highest germination percentages (%) of broad bean, shoot and root length and weight, and seed vigor index were obtained after Chito treatment with a concentration of 200 µg mL−1 compared to Chito-TZ. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
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29. Therapeutic Outcomes of High Dose-Dexamethasone versus Prednisolone + Azathioprine, Rituximab, Eltrombopag, and Romiplostim Strategies in Persistent, Chronic, Refractory, and Relapsed Immune Thrombocytopenia Patients.
- Author
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Hamed, Eman Mostafa, Ibrahim, Ahmed R. N., Meabed, Mohamed Hussein, Khalaf, Ahmed M., El Demerdash, Doaa Mohamed, Elgendy, Marwa O., Saeed, Haitham, Salem, Heba F., and Rabea, Hoda
- Subjects
- *
THROMBOPOIETIN receptors , *IDIOPATHIC thrombocytopenic purpura , *RITUXIMAB , *ROMIPLOSTIM , *ELTROMBOPAG , *AZATHIOPRINE , *PREDNISOLONE - Abstract
Background: Primary immune thrombocytopenia (ITP) is an inflammatory autoimmune disease that can be managed with several treatment options. However, there is a lack of comparative data on the efficacy of these options in different phases of the disease. Aim of the study: This study aimed to evaluate the efficacy of high-dose Dexamethasone (HD-DXM), Prednisolone + Azathioprine, Rituximab, Eltrombopag, and Romiplostim schedules in persistent, chronic refractory or relapsed Egyptian ITP patients with a platelet count ≤30 × 109/L. The primary outcome measure was a sustained increase in platelet counts over 50 × 109/L for an additional 12 months without additional ITP regimens. The study also aimed to identify a suitable treatment regimen with a long remission duration for each phase of ITP. Results: Prednisolone + Azathioprine was significantly more effective in achieving an overall response in persistent patients than Romiplostim, high-dose Dexamethasone, and Rituximab. (90.9% vs. 66.6, [Odds ratio, OR: 5; confidence interval, CI 95% (0.866–28.86)], 45%, [OR: 0.082, CI 95% (0.015–0.448)] and, 25%, [OR: 30, CI 95% (4.24–211.8)], respectively, p-value < 0.01). Eltrombopag was significantly more effective in achieving a durable response in refractory ITP than HD-DXM, Rituximab, and Prednisolone; (80% compared to 32.2% [OR: 0.119, CI 95% (0.035–0.410)], 22.2% [OR:0.071, CI 95% (0.011–0.455)], and 18.1% [OR: 0.056, CI 95% (0.009–0.342)], respectively, p-value < 0.01). Conclusions: Finally, Eltrombopag following HD-DXM showed the highest percentage of patients with complete treatment-free survival times of at least 330 days. These findings could help clinicians choose the most appropriate treatment for their patients with ITP based on the phase of the disease. This trial is registered in clinicaltrials.gov with registration number NCT05861297. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
30. Fat enhanced leukocyte-platelet-rich fibrin versus fascia lata in endoscopic reconstruction of CSF leaks.
- Author
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Ibrahim, Ahmed Aly, Yoneis, Ahmed, Elsakka, Ahmed, and Elwany, Samy
- Subjects
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CEREBROSPINAL fluid leak , *FIBRIN , *SKULL base , *FAT , *INTRACRANIAL pressure , *MYELOGRAPHY - Abstract
Purpose: The aim of this study was to use a new biological active fat enhanced leukocyte-platelet-rich fibrin membrane (L-PRF) for skull base defect reconstruction and compare its validity and reliability with the time-honored fascia lata. Methods: This prospective study was conducted on 48 patients with spontaneous CSF leaks who were divided into 2 matched groups by stratified randomization, 24 patients in each group. In group A we performed multilayer repair using fat enhanced L-PRF membrane. In group B we used fascia lata for the multilayer repair. In both groups we enforced the repair with mucosal grafts/flaps. Results: The two groups were statistically matched for age, sex, intracranial pressure, and site and size of the skull base defect. There was no statistically significant difference between the two groups regarding the outcome of the repair or recurrence of CSF leak during the first postoperative year. Meningitis occurred in one patient in group B and was successfully treated. Another patient in group B developed thigh hematoma which resolved spontaneously. Conclusion: The fat enhanced L-PRF membrane is a valid reliable option in repair of CSF leaks. The membrane is autologous, readily available, easily prepared, and has the advange of including stromal fat, stromal vascular fraction (SVF), and leukocyte-platelet-rich fibrin (L-PRF). The present study showed that fat enhanced L-PRF membrane is stable, non-absorbable, not liable to shrink or become necrotic, and can establish good seal of the skull base defect and further enhance the healing process. The use of the membrane also has the advantage of avoiding thigh incision and possible hematoma formation. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
31. Engineered Interleaved Random Glass Fiber Composites Using Additive Manufacturing: Effect of Mat Properties, Resin Chemistry, and Resin-Rich Layer Thickness.
- Author
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Ibrahim, Ahmed M. H., Idrees, Mohanad, Tekerek, Emine, Kontsos, Antonios, Palmese, Giuseppe R., and Alvarez, Nicolas J.
- Subjects
- *
GLASS composites , *FIBROUS composites , *TRANSFER molding , *AUTOMATIC control systems , *FRACTURE toughness , *GLASS fibers , *PRINT materials , *FLUOROSCOPY - Abstract
Standard lay-up fabrication of fiber-reinforced composites (FRCs) suffer from poor out-of-plane properties and delamination resistance. While advanced manufacturing techniques (e.g., interleaving, braiding, and z-pinning) increase delamination resistance in FRCs, they typically result in significant fabrication complexity and limitations, increased manufacturing costs, and/or overall stiffness reduction. In this work, we demonstrate the use of facile digital light processing (DLP) technique to additively manufacture (AM) random glass FRCs with engineered interleaves. This work demonstrates how vat photo-polymerization techniques can be used to build composites layer-by-layer with controlled interleaf material, thickness, and placement. Note that this engineering control is almost impossible to achieve with traditional manufacturing techniques. A range of specimens were printed to measure the effect of interleaf thickness and material on tensile/flexural properties as well as fracture toughness. One important observation was the ≈60% increase in interlaminar fracture toughness achieved by using a tough resin material in the interleaf. The comparison between AM and traditionally manufactured specimens via vacuum-assisted resin transfer molding (VARTM) highlighted the limitation of AM techniques in achieving high mat consolidation. In other words, the volume fraction of AM parts is limited by the wet fiber mat process, and engineering solutions are discussed. Overall, this technique offers engineering control of FRC design and fabrication that is not available with traditional methods. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
32. Enhanced Autonomous Vehicle Positioning Using a Loosely Coupled INS/GNSS-Based Invariant-EKF Integration.
- Author
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Ibrahim, Ahmed, Abosekeen, Ashraf, Azouz, Ahmed, and Noureldin, Aboelmagd
- Subjects
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GLOBAL Positioning System , *LIE groups , *INERTIAL navigation systems , *TUNNELS , *KALMAN filtering - Abstract
High-precision navigation solutions are a main requirement for autonomous vehicle (AV) applications. Global navigation satellite systems (GNSSs) are the prime source of navigation information for such applications. However, some places such as tunnels, underpasses, inside parking garages, and urban high-rise buildings suffer from GNSS signal degradation or unavailability. Therefore, another system is required to provide a continuous navigation solution, such as the inertial navigation system (INS). The vehicle's onboard inertial measuring unit (IMU) is the main INS input measurement source. However, the INS solution drifts over time due to IMU-associated errors and the mechanization process itself. Therefore, INS/GNSS integration is the proper solution for both systems' drawbacks. Traditionally, a linearized Kalman filter (LKF) such as the extended Kalman filter (EKF) is utilized as a navigation filter. The EKF deals only with the linearized errors and suppresses the higher orders using the Taylor expansion up to the first order. This paper introduces a loosely coupled INS/GNSS integration scheme using the invariant extended Kalman filter (IEKF). The IEKF state estimate is independent of the Jacobians that are derived in the EKF; instead, it uses the matrix Lie group. The proposed INS/GNSS integration using IEKF is applied to a real road trajectory for performance validation. The results show a significant enhancement when using the proposed system compared to the traditional INS/GNSS integrated system that uses EKF in both GNSS signal presence and blockage cases. The overall trajectory 2D-position RMS error reduced from 19.4 m to 3.3 m with 82.98 % improvement and the 2D-position max error reduced from 73.9 m to 14.2 m with 80.78 % improvement. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
33. Topological Properties of Solution Sets for τ -Fractional Non-Instantaneous Impulsive Semi-Linear Differential Inclusions with Infinite Delay †.
- Author
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Alsheekhhussain, Zainab, Ibrahim, Ahmed Gamal, and Jawarneh, Yousef
- Subjects
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DIFFERENTIAL inclusions , *TOPOLOGICAL property , *FRACTIONAL calculus - Abstract
The knowledge of fractional calculus can be useful in developing models that allow us to better understand and manage some phenomena. In the present paper, we study the topological structure of the mild solution set for a semi-linear differential inclusion containing the τ -Caputo fractional derivative in the presence of non-instantaneous impulses and an infinite delay. We demonstrate that this set is non-empty and an R δ -set. We use a recent result regarding the existence of solutions for τ -Caputo fractional semi-linear differential inclusions. Unlike many results, we do not suppose that the generating semigroup is compact. An illustrative example is given as an application of our results. [ABSTRACT FROM AUTHOR]
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- 2023
- Full Text
- View/download PDF
34. Effect of Crude Oil Properties on the Interfacial Tension of Crude Oil/CO2 Under HPHT Conditions.
- Author
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Ibrahim, Ahmed F., Abdelgawad, Khaled Z., Al-Anazi, Amer, and Al Hamad, Jafar S.
- Subjects
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PETROLEUM , *INTERFACIAL tension , *CARBON dioxide injection , *HYDROCARBON reservoirs , *PETROLEUM reservoirs - Abstract
Injection of carbon dioxide (CO2) is an effective method to improve oil recovery from hydrocarbon reservoirs. The interfacial tension (IFT) between CO2 and crude oil is a critical parameter during CO2 flooding. IFT of different crude oils in compressed carbon dioxide was measured at different pressures and temperatures. The minimum miscibility and first-contact miscibility pressures were calculated using vanishing IFT analysis. The minimum miscibility pressure is significantly affected by temperature with less dependency on the crude oil composition. The first-contact miscibility pressure was found to be more sensitive to temperature and crude composition. Measured IFT values at different pressure and temperature conditions were correlated to crude oil density and acid number using a wide range of crude gravity and total acid number. These properties are simple and less costly to measure but they directly reflect the effect of crude oil composition on IFT as a function of pressure. This new approach of correlating IFT between CO2 and crude oil under reservoir conditions will improve the simulation of CO2 EOR projects under reservoir conditions. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
35. Synthesis of Acrylamide-co-3-Allyloxy-2-hydroxy-1-propanesulfonic acid sodium salt Hydrogel for efficient Adsorption of Methylene blue dye.
- Author
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Elkony, Amin Mohamed, Ibrahim, Ahmed G., Abu El-Farh, Maher Hamed, and Abdelhai, Farag
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SODIUM salts , *ADSORPTION kinetics , *HYDROGELS , *ADSORPTION , *METHYLENE blue , *ADSORPTION isotherms , *ADSORPTION capacity - Abstract
In this work, novel copolymer hydrogel was designed from acrylamide (AAm) and 3-Allyloxy-2-hydroxy-1-propanesulfonic acid sodium salt (AHPS) through the free radical mechanism to produce an efficient adsorbent for removing the methylene blue dye from its aqueous solution. Tracking the gel fraction showed a decrease by increasing the AHPS concentration. The obtained polymers were characterised by FTIR, TGA, and SEM. The swelling behaviour was investigated, and the results indicated the enhancement in the swelling ratio for the hydrogels containing AHPS, and the maximum swelling ratio (4353.8%) was achieved after increasing the molar ratio of AHPS to 15%. The influence of different parameters such as contact time, dye concentration, pH, polymer dose, and temperature on the adsorption of methylene blue was studied. Studying the adsorption kinetics and isotherm showed that the adsorption process was well described by the pseudo-second-order and the Langmuir model, and the maximum adsorption capacity (qm) was 703.2 mg/g. Estimation of the thermodynamic parameters showed negative values of ∆G indicating the spontaneous nature of the adsorption process, the positive ∆H value (13.7 kJ mol−1) confirming the endothermic nature of MB adsorption, and the positive value of ∆S (0.048 KJ K−1 mol−1) indicating increased randomness at the solid/solution interface. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
36. NANOMATERIALS IMPLANTATION FOR ACCELERATING BONE HEALING.
- Author
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IBRAHIM, AHMED, ELSHAHAWY, ABDELNABY, HASSANEIN, KHALED M. A., HUSSEIN, SHEREEN IBRAHIM ZAKARIA, and SEMIEKA, MOHAMMED M. A.
- Subjects
- *
RADIAL bone , *NANOSTRUCTURED materials , *HEALING , *GRAPHENE oxide , *INTRAVENOUS anesthesia - Abstract
The present study was conducted on 9 non-medicated, clinically healthy, adult mongrel male dogs. The dogs had no orthopedic abnormalities. Dogs were subjected to mid-diaphyseal circular bone defect (0.8 cm in diameter) in the left radius bones under general anesthesia. Dogs were divided randomly to be allocated into two groups, each of 3 dogs. The treated group (group T, n = 3), in which bone defects were implanted with the titanium oxide/graphene oxide/chitosan nanocomposite. The control group (group C, n = 3), in which bone defects were allowed for spontaneous healing. Dogs were subjected to clinical and radiographical evaluation 30 days postoperatively. All surgical procedures were conducted under the effect of total intravenous anesthesia (TIVA). Digital cranio-palmar and lateral views were taken for the operated limbs. Cortical defects and depth of the bone defects were recorded using the RadiAnt DICOM viewer version 1.1.2022 software. There was a significant decrease (P < 0.05) in the cortical defect in the treated group compared with the control groups 30 days postoperatively. The treated group recorded a significant decrease (P < 0.05) in 30 days compared to the baseline value. The depth of the bone defects decreased significantly (P < 0.05) in the treated group compared with the untreated group 30 days post-induction of the bone defects. There was a significant decrease (P < 0.05) in the treated group on 30 days compared to the baseline value. The titanium oxide/graphene oxide/chitosan nanocomposite accelerates the healing of bone defects. [ABSTRACT FROM AUTHOR]
- Published
- 2023
37. Natural convection from a horizontal cylinder placed in a square enclosure: CFD simulations.
- Author
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Mahmood, Raid Ahmed, Ibrahim, Ahmed Khalid, Kamilxy, Ali Ghazi Mohammed, and Saeed, Ramiz Ibraheem
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RAYLEIGH number , *NATURAL heat convection , *HEAT conduction , *NUSSELT number , *HEAT transfer , *HEAT transfer fluids , *SURFACE temperature - Abstract
Natural convection from a horizontal cylinder placed in a square enclosure is numerically investigated using two different fluids as a heat transfer medium. Water and air are used as two different heat transfer mediums. The diameter and length of the cylinder are 50 mm and 500 mm respectively. The cylinder is placed in a close square enclosure of 300 mm x 300 mm. The range of operating conditions covered different surface temperature from 303 K to 414 K. Two-dimensional Computational Fluid Dynamic (CFD) approach is used to predict the natural convection when water and air are the heat transfer mediums. The Nusselt number is estimated and compared with the experimental result which is obtained from previous study with maximum absolute percentage error of 13%. The results show that the surface temperature has a direct and significant effect on the Nusselt number when the cylinder is surrounded by air as a medium for the heat transfer with maximum velocity varied from 0.007 m/s to 0.11 m/s. Conduction heat transfer mode is the dominant mod when the cylinder is surrounded by water with maximum velocity of 0.3 m/s. at surface temperature of 350 K. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
38. Data-driven models to predict shale wettability for CO2 sequestration applications.
- Author
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Ibrahim, Ahmed Farid and Elkatatny, Salaheldin
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SHALE , *MACHINE learning , *WETTING , *ARTIFICIAL neural networks , *SUPPORT vector machines , *CONTACT angle - Abstract
The significance of CO2 wetting behavior in shale formations has been emphasized in various CO2 sequestration applications. Traditional laboratory experimental techniques used to assess shale wettability are complex and time-consuming. To overcome these limitations, the study proposes the use of machine learning (ML); artificial neural networks (ANN), support vector machines (SVM), and adaptive neuro-fuzzy inference systems (ANFIS) tools to estimate the contact angle, a key indicator of shale wettability, providing a more efficient alternative to conventional laboratory methods. A dataset comprising various shale samples under different conditions was collected to predict shale-water-CO2 wettability by considering shale properties, operating pressure and temperature, and brine salinity. Pearson's correlation coefficient (R) was utilized to assess the linearity between the contact angle (CA) value and other input parameters. Initial data analysis showed that the elements affecting the shale wettability are primarily reliant on the pressure and temperature at which it operates, the total organic content (TOC), and the mineral composition of the rock. Between the different ML models, the artificial neural network (ANN) model performed the best, achieving a training R2 of 0.99, testing R2 of 0.98 and a validation R2 of 0.96, with an RMSE below 5. The adaptive neuro-fuzzy inference system (ANFIS) model also accurately predicted the contact angle, obtaining a training R2 of 0.99, testing R2 of 0.97 and a validation R2 of 0.95. Conversely, the support vector machine (SVM) model displayed signs of overfitting, as it achieved R2 values of 0.99 in the training dataset, which decreased to 0.94 in the testing dataset, and 0.88 in the validation dataset. To avoid rerunning the ML models, an empirical correlation was developed based on the optimized weights and biases obtained from the ANN model to predict contact angle values using input parameters and the validation data set revealed R2 of 0.96. The parametric study showed that, among the factors influencing shale wettability at a constant TOC, pressure had the most significant impact, and the dependency of the contact angle on pressure increased when TOC values were high. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
39. Optimizing barium promoter for nickel catalyst supported on yttria‐stabilized zirconia in dry reforming of methane.
- Author
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Al‐Fatesh, Ahmed Sadeq, Ibrahim, Ahmed Aidid, Osman, Ahmed I., Albaqi, Fahad, Arasheed, Rasheed, Francesco, Frusteri, Serena, Todaro, Anojaidi, Khalid, Lanre, Mahmud Sofiu, Abasaeed, Ahmed Elhag, Fakeeha, Anis Hamza, Bentalib, Abdulaziz, and Bagabas, Abdulaziz
- Subjects
- *
CATALYST supports , *NICKEL catalysts , *YTTRIA stabilized zirconium oxide , *BARIUM , *MULTIWALLED carbon nanotubes , *CATALYTIC activity , *ZIRCONIUM oxide - Abstract
Barium doping effect on the activity and stability of nickel‐based catalysts, supported on yttria‐stabilized zirconia (Ni‐YZr), was investigated in dry reforming of methane. Catalysts were characterized by several techniques (nitrogen sorption, X‐ray diffraction [XRD], scanning electron microscopy with energy dispersive X‐ray, transmission electron microscopy [TEM], thermogravimetric analysis [TGA], temperature programmed oxidation, CO2‐TPD, H2‐TPR) and were tested in a fixed‐bed reactor at 800°C and 42,000 mL/h gcat. Barium played a crucial role in enhancing catalyst reducibility and CO2 adsorption at high temperatures, as indicated by the activity and stability of the Ni‐YZr catalyst. The addition of 4.0 wt% of barium appeared to be the optimal loading, allowing for CH4 conversion of 82%, which remained constant for 7 h of reaction, compared with 72% of barium‐unpromoted Ni‐YZr at 800°C. TEM images of the spent catalysts revealed the formation of multiwalled carbon nanotubes on all samples. The TGA analysis showed, however, that an increase in baria loading significantly reduced the coke formation amount, indicating the inhibition of coke formation and the enhancement of the catalytic activity. Such improvement in activity and stability was attributed to the incorporation of barium into YZr support, as revealed by XRD analysis, which inhibited the sintering of the catalysts support. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
40. The Outcomes and Adverse Drug Patterns of Immunomodulators and Thrombopoietin Receptor Agonists in Primary Immune Thrombocytopenia Egyptian Patients with Hemorrhage Comorbidity.
- Author
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Hamed, Eman Mostafa, Ibrahim, Ahmed R. N., Meabed, Mohamed Hussein, Khalaf, Ahmed M., El Demerdash, Doaa Mohamed, Elgendy, Marwa O., Saeed, Haitham, Salem, Heba F., and Rabea, Hoda
- Subjects
- *
THROMBOPOIETIN receptors , *THROMBOPOIETIN receptor agonists , *IDIOPATHIC thrombocytopenic purpura , *EGYPTIANS , *IMMUNOMODULATORS , *LUTEINIZING hormone releasing hormone , *ROMIPLOSTIM - Abstract
Immune thrombocytopenia (ITP) treatment has evolved recently. However, none of the treatments have only benefits without drawbacks. This study aimed to compare the clinical outcomes and adverse drug patterns of Eltrombopag, Romiplostim, Prednisolone + Azathioprine, High Dose-dexamethasone (HD-DXM) (control group), and Rituximab in primary ITP Egyptian patients. All patients were initiated with corticosteroids, HD-DXM, as a first-line treatment for the first month immediately following diagnosis. Four hundred sixty-seven ITP patients were randomly assigned to five groups. The outcome measures were judged at baseline, at the end of treatment (6 months), and after an additional 6-month free treatment period. The follow-up period for which relapse is noted was 6 months after the end of treatment. Eltrombopag and Romiplostim resulted in a significantly higher incidence of sustained response than Rituximab, HD-DXM, and Prednisolone + Azathioprine (55.2% and 50.6% vs. 29.2%, 29.1%, and 18%, respectively; p-value < 0.001). More patients on immunomodulators (Prednisolone+ Azathioprine, HD-DXM, and Rituximab) relapsed than those on Romiplostim and Eltrombopag (81.9%, 70.8%, and 70.7% vs. 49.3%, and 44.7%, respectively; p-value < 0.01). We also describe 23 reports of pulmonary hypertension with Prednisolone+ Azathioprine and 13 reports with HD-DXM. The thrombotic events occurred in 16.6% and 13% of patients who received Eltrombopag and Romiplostim treatment, respectively. Most patients had at least one or two risk factors (92.8% of cases). Corticosteroids are effective first-line therapy in primary ITP patients. However, relapse is frequent. Eltrombopag and Romiplostim are safer and more effective than Prednisolone, HD-DXM, and Rituximab. They might be reasonable beneficial options after a one-month HD-DXM regimen. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
41. Flexible and frequency reconfigurable CPW-fed monopole antenna with frequency selective surface for IoT applications.
- Author
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Ibrahim, Ahmed A., Mohamed, Hesham. A., Abdelghany, Mahmoud A., and Tammam, Emad
- Subjects
- *
FREQUENCY selective surfaces , *MONOPOLE antennas , *ANTENNA design , *ANTENNAS (Electronics) , *PIN diodes , *INTERNET of things , *WIRELESS LANs , *BEAM steering - Abstract
This paper proposes a flexible, frequency-reconfigurable monopole antenna design with frequency selective surface (FSS) for Internet of Things (IoT) applications. The proposed antenna operates at three of the IoT frequency bands. This antenna is a coplanar waveguide (CPW)-fed monopole with two balanced arms printed on a thin ROGERS 3003 flexible substrate. The length of the right-hand arm of the antenna is used to achieve frequency reconfiguration by using PIN diodes. Three frequency modes of operation have been obtained; the 2.4 GHz frequency band with the right-hand arm is fully truncated, the 3.5 GHz frequency band with the two arms is completely maintained, and the 4 GHz frequency band with the right-hand arm is partially truncated. To improve the gain of the antenna, a simple FSS surface is designed to be placed under the antenna at a distance of 15 mm. The FSS operates efficiently from 2 to 4.5 GHz and has improved the gain of the antenna. A maximum gain of 6.5 dBi, 7.52 dBi, and 7.91 dBi has been achieved at the three frequency bands respectively. The behavior of the flexible antenna has been evaluated in both the flat and bent states, and stable performance has been observed in both cases. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
42. A correlation coefficient-based feature selection approach for virus-host protein-protein interaction prediction.
- Author
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Ibrahim, Ahmed Hassan, Karabulut, Onur Can, Karpuzcu, Betül Asiye, Türk, Erdem, and Süzek, Barış Ethem
- Subjects
- *
FEATURE selection , *CLASSIFICATION algorithms , *RANDOM forest algorithms , *PREDICTION models , *FORECASTING , *STATISTICAL correlation , *PROTEIN-protein interactions , *TRIPEPTIDES - Abstract
Prediction of virus-host protein-protein interactions (PPI) is a broad research area where various machine-learning-based classifiers are developed. Transforming biological data into machine-usable features is a preliminary step in constructing these virus-host PPI prediction tools. In this study, we have adopted a virus-host PPI dataset and a reduced amino acids alphabet to create tripeptide features and introduced a correlation coefficient-based feature selection. We applied feature selection across several correlation coefficient metrics and statistically tested their relevance in a structural context. We compared the performance of feature-selection models against that of the baseline virus-host PPI prediction models created using different classification algorithms without the feature selection. We also tested the performance of these baseline models against the previously available tools to ensure their predictive power is acceptable. Here, the Pearson coefficient provides the best performance with respect to the baseline model as measured by AUPR; a drop of 0.003 in AUPR while achieving a 73.3% (from 686 to 183) reduction in the number of tripeptides features for random forest. The results suggest our correlation coefficient-based feature selection approach, while decreasing the computation time and space complexity, has a limited impact on the prediction performance of virus-host PPI prediction tools. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
43. (NH4)2[Co(H2O)6]2V10O28·4H2O Vs. (NH4)2[Ni(H2O)6]2V10O28·4H2O: Structural, Spectral and Thermal Analyses and Evaluation of Their Antibacterial Activities
- Author
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Mamdouh, Ayat-Allah, Ibrahim, Ahmed B. M., Reyad, Nour El-Houda A., Elsayed, Tarek R., Santos, Isabel Cordeiro, Paulo, António, and Mahfouz, Refaat M.
- Subjects
- *
PHYTOPATHOGENIC bacteria , *ESCHERICHIA coli O157:H7 , *ESCHERICHIA coli , *DRUG standards , *ANTIBACTERIAL agents , *RALSTONIA solanacearum - Abstract
This paper presents the synthesis of two cluster compounds {(NH4)2[Co(H2O)6]2V10O28·4H2O (C1) and (NH4)2[Ni(H2O)6]2V10O28·4H2O (C2)} which were obtained as single crystals suitable for XRD analysis that revealed their crystallization in the monoclinic (C2/c) and triclinic (P-1) space groups, respectively. Additionally, C1 and C2 were characterized using CHN analysis and FT-IR spectroscopy and their thermal decomposition mechanisms were investigated. The antibacterial activities of both compounds were determined against three human pathogenic bacterial strains {Bacillus cereus ATCC 33,018, Escherichia coli O157:H7 and Pseudomonas aeruginosa ATCC 9027} and one phytopathogenic bacterial strain {Ralstonia solanacearum}, while drug standards {chloramphenicol and streptomycin} were used as control. The inhibitory activity and the minimum inhibitory concentration (MIC) values of the tested compounds clearly indicated higher antibacterial activities of the nickel compound against B. cereus ATCC 33,018, E. coli O157 and R. solanacearum with MIC values of 3.150, 3.150 and 6.300 mg/ml, respectively. On the other hand, (NH4)2[Co(H2O)6]2V10O28·4H2O exhibited higher antibacterial activity against P. aeruginosa ATCC 9027 (MIC value of 6.300 mg/ml) in comparison to the nickel analog. In general, the measured activities are lower than that obtained for the standards except for the higher activity given by C2 in comparison to streptomycin against the R. solanacearum strain. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
44. Four-Port 38 GHz MIMO Antenna with High Gain and Isolation for 5G Wireless Networks.
- Author
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Ibrahim, Ahmed A., Ali, Wael A. E., Alathbah, Moath, and Sabek, Ayman R.
- Subjects
- *
ANTENNAS (Electronics) , *REFLECTOR antennas , *5G networks , *MONOPOLE antennas , *MICROSTRIP antennas , *WIRELESS communications - Abstract
In this paper, a 38 GHz 4-port multiple-input multiple-output (MIMO) antenna with considerable isolation and gain enhancement for 5G applications is introduced. The suggested antenna element is a monopole antenna composed of a circular patch with a rectangular slot etched from it and a partial ground plane is used to extend the desired frequency to operate from 36.6 GHz to 39.5 GHz with a center frequency of 38 GHz. The high isolation is achieved by arranging the four elements orthogonally and adding four stubs to reduce mutual coupling between elements at the desired frequency bands. The gain improvement is also introduced by placing a frequency selective structure (FSS) which is designed at the same frequency bands of the antenna under the suggested MIMO antenna to act as a reflector. The proposed four-element MIMO with the FSS prototype is built and tested in order to confirm the simulated results. The suggested antenna operated from 37.2 GHz to 39.2 GHz with an isolation of less than 25 dB across the obtained frequency range. The peak gain of the antenna is enhanced from 5.5 dBi to around 10 dBi by utilizing the FSS structure; furthermore, the back radiation is enhanced. The MIMO performance is validated by extracting its parameters and comparing with the simulated results. The results extracted from the simulation and the measurement show satisfactory matching along with the target band, indicating that the proposed structure could be used for 5G communications. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
45. Role of Ultrasound and Computed Tomography in Evaluation of Salivary Glands Lesions.
- Author
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Abdellatif, Hayam Abdelmonsif, Ibrahim, Ahmed Sameh Mohamed, and Dessuky, Basma Abdelmoneim
- Subjects
- *
SALIVARY glands , *COMPUTED tomography , *SIALOLITHIASIS , *SIALADENITIS , *ULTRASONIC imaging , *PAROTID glands , *VIRUS diseases - Abstract
Background: The most typical reason for salivary gland swellings is mumps, one of the viral diseases of the salivary gland. Another reason for swelling is a tumor. The parotid glands are the primary source of around 70% of salivary gland tumors. The initial imaging technique for swollen salivary glands is ultrasound. Examining the deep lobe of the parotid with ultrasound (U/S) is challenging. Objective: The aim of the current work was to evaluate the role of ultrasound and computed tomography (CT) in the differentiation between benign and malignant salivary glands lesions. Patients and Methods: A cross sectional analytic study was conducted on 46 patients with swellings in the head and neck of either gender referred from the outpatient clinics of ENT, head and neck surgery and dentists to Radiology Department, Faculty of Medicine, Menoufia university, Sheikh Zayed Specialized Hospital, and some private center during the period from November 2021 to November 2022. Results: showed that, primary and final diagnoses of salivary gland lesions by ultrasound and computed tomography were the same, that (39.1%) of patients suffered from sialadenitis, followed by both of sialolithiasis and benign tumor (21.7%), followed by malignant tumors (8.7%), and abscess and cystic lesion (4.3%). Inflammatory lymph nodes was significantly higher in ultrasound than computed tomography versus pathological lymph nodes, it was significantly higher in CT than U/S (p=0.032). Conclusions: It could be concluded that CT and ultrasonography can be used to diagnose abnormalities of the salivary glands accurately. It is a helpful imaging technique for evaluating salivary gland masses. It could assist in distinguishing between benign and malignant tumors and reduce the range of possible diagnosis. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
46. Serum Osteoprotegerin (OPG) as a Potential Biomarker for Disease Activity in Ulcerative Colitis.
- Author
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Ibrahim, Ahmed Ahmed Al-said, El-Azab, Gasser Ibrahim, Allam, Naglaa Allam Ahmed, Hassouna, Mona Mahmoud, and Edrees, Ahmed Mohamed
- Subjects
- *
ULCERATIVE colitis , *OSTEOPROTEGERIN , *BIOMARKERS , *INTESTINAL mucosa , *AGE groups - Abstract
Background: Inflammation and ulceration of the intestinal mucosa occur repeatedly in patients with ulcerative colitis (UC), leading to numerous bouts of bleeding per rectum. Objective: To evaluate serum osteoprotegerin (OPG) level in cases who had ulcerative colitis and its correlation with disease activity. Patients and Methods: This case control was conducted at the National Liver Institute, Menoufia University on 89 patients. They were divided into two groups and were matched in age and gender: Group I: 50 patients with ulcerative colitis diagnosed utilizing colonoscopy and histopathological examination. Group II: 39 individuals who had normal colonoscopic findings (grossly and histopathologically) as a control group. Results: Differences in OPG readings between the control group and UC subgroups were statistically significant. The mean OPG level in patients with extraintestinal manifestations (EIM) was 596 ± 365 pg/ml, while the mean OPG level in patients without EIM was 384 ± 333 pg/ml. OPG levels were not significantly linked to the prevalence of extraintestinal symptoms. The concentration of OPG was positively correlated with disease severity. Conclusion: The present study suggested that serum osteoprotegerin can be considered as a novel biomarker for assessing ulcerative colitis activity. [ABSTRACT FROM AUTHOR]
- Published
- 2023
47. Effect of milling time and boron carbide content on some physical and mechanical properties of an aluminum-based system.
- Author
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Ibrahim, Ahmed M., Allah, Sabah Mahmoud Aman, and Darweesh, Salih Y.
- Subjects
- *
BORON carbides , *INTERNAL combustion engines , *MECHANICAL wear , *HYDRAULIC presses , *FIXED interest rates , *LIGHT aircraft - Abstract
Powder technology is characterized by the production of models with multiple application characteristics in different industries that require strength in durability and light weight such as aircraft parts and internal combustion engines. The current study employs this technology to produce models from a mineral base of aluminum (Al) reinforced with Al2O3 with a fixed rate of 5%, and in different proportions of B4C boron carbide of % (0,5,10,15,20). The preparation process was conducted by mixing the powders for three consecutive times (2,4,6) hours with a homemade mill containing steel powder and steel balls. Hydraulic press is used to generate samples at a pressure (100 bar) and for a time of one minute; the samples produced from the mold are of green density and require a sintering process for the purpose of increasing the hardness and durability. The physical characteristics of the samples included (Bulk density and true porosity). The wear rate was studied and the samples produced good results after the sintering procedure at six hours of milling. The results showed a bulk density of (2.128g/cm3), a true porosity (9.98%) and lower wear rate of (1.59×10-8 g/cm). It was thus found that the best grinding time that produced good physical and mechanical properties is six hours, and the best strengthening ratio is 20% B4C when sintering at 560°C. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
48. Synthesized Zeolite Based on Egyptian Boiler Ash Residue and Kaolin for the Effective Removal of Heavy Metal Ions from Industrial Wastewater.
- Author
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Ibrahim, Ahmed H., Lyu, Xianjun, and ElDeeb, Amr B.
- Subjects
- *
LEAD removal (Water purification) , *SEWAGE , *INDUSTRIAL wastes , *METAL ions , *ZEOLITES , *HEAVY metals - Abstract
The increase of global environmental restrictions concerning solid and liquid industrial waste, in addition to the problem of climate change, which leads to a shortage of clean water resources, has raised interest in developing alternative and eco-friendly technologies for recycling and reducing the amount of these wastes. This study aims to utilize Sulfuric acid solid residue (SASR), which is produced as a useless waste in the multi-processing of Egyptian boiler ash. A modified mixture of SASR and kaolin was used as the basic component for synthesizing cost-effective zeolite using the alkaline fusion-hydrothermal method for the removal of heavy metal ions from industrial wastewater. The factors affecting the synthesis of zeolite, including the fusion temperature and SASR: kaolin mixing ratios, were investigated. The synthesized zeolite was characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), particle size analysis (PSD) and N2 adsorption-desorption. The SASR: kaolin weight ratio of 1:1.5 yields faujasite and sodalite zeolite with 85.21% crystallinity, which then shows the best composition and characteristics of the synthesized zeolite. The factors affecting the adsorption of Zn2+, Pb2+, Cu2+, and Cd2+ ions from wastewater on synthesized zeolite surfaces, including the effect of pH, adsorbent dosage, contact time, initial concentration, and temperature, have been investigated. The obtained results indicate that a pseudo-second-order kinetic model and Langmuir isotherm model describe the adsorption process. The maximum adsorption capacities of Zn2+, Pb2+, Cu2+, and Cd2+ ions onto zeolite at 20 °C were 12.025, 15.96, 12.247, and 16.17 mg·g−1, respectively. The main mechanisms controlling the removal of these metal ions from aqueous solution by synthesized zeolite were proposed to be either surface adsorption, precipitation, or ion exchange. The quality of the wastewater sample obtained from the Egyptian General Petroleum Corporation (Eastern Desert, Egypt) was highly improved using the synthesized zeolite and the content of heavy metal ions was significantly reduced, which enhances the utilization of the treated water in agriculture. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
49. Estimation of rocks' failure parameters from drilling data by using artificial neural network.
- Author
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Siddig, Osama, Ibrahim, Ahmed Farid, and Elkatatny, Salaheldin
- Subjects
- *
HYDRAULIC fracturing , *ROCK properties , *ROCK deformation , *ROCK testing , *OIL well drilling rigs , *ESTIMATION theory , *PENETRATION mechanics - Abstract
Comprehensive and precise knowledge about rocks' mechanical properties facilitate the drilling performance optimization, and hydraulic fracturing design and reduces the risk of wellbore-related problems. This paper is concerned with the failure parameters, namely, cohesion and friction angle which are conventionally estimated using Mohr's cycles that are drawn using compressional tests on rock samples. The availability, continuity and representability, and cost of acquiring those samples are major concerns. The objective of this paper is to investigate an alternative technique to estimate these parameters from the drilling data. In this work, more than 2200 data points were used to develop and test the correlations built by the artificial neural network. Each data point comprises the failure parameters and five drilling records that are available instantaneously in drilling rigs such as rate of penetration, weight on bit, and torque. The data were grouped into three datasets, training, testing, and validation with a corresponding percentage of 60/20/20, the former two sets were utilized in the models' building while the last one was hidden as a final check afterward. The models were optimized and evaluated using the correlation coefficient (R) and average absolute percentage error (AAPE). In general, the two models yielded good fits with the actual values. The friction angle model yielded R values around 0.86 and AAPE values around 4% for the three datasets. While the model for cohesion resulted in R values around 0.89 and APPE values around 6%. The equation and the parameters of those models are reported in the paper. These results show the ability of in-situ and instantaneous rock mechanical properties estimation with good reliability and at no additional costs. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
50. Serum Ferritin Levels and Other Associated Parameters with Diabetes Mellitus in Adult Patients Suffering from Beta Thalassemia Major.
- Author
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Ibrahim, Ahmed Saleh, El-Fatah, Azza Hasan Abd, El-Halim, Ayman Fathy Abd, and Mohamed, Farid Fawzy
- Subjects
- *
BETA-Thalassemia , *CARDIAC magnetic resonance imaging , *DIABETES , *FERRITIN , *IRON - Abstract
Background: Although beta thalassemia major (BTM) patients are properly treated with blood transfusions in accompany with iron chelation therapy, they suffer from complications, such as diabetes mellitus (DM). Purpose: The purpose was to detect the critical serum ferritin level and other parameters correlated with DM among adult BTM patients. Also, it was to study whether each of these parameters is associated with a certain period of age. Patients and Methods: This study included 200 adult BTM patients. A cross-sectional study was carried out. Patients clinical and laboratory variables, such as ferritin levels, and fasting blood glucose (FBS) were extracted from medical records at Zagazig University Hospital, Egypt. Liver and cardiac iron contents were assessed using MRI T2* methods. Statistical analysis was performed using IBM SPSS V26.0 software package. Results: The overall frequency of DM over the total sample equals 6.5%. There were no impaired fasting glucose (IFG) in the medical records. Statistical significance between serum ferritin and DM was (P = 0.014). The serum ferritin 2500 ng/mL with age group (27–< 32) years-old were risk factors. The distributions of DM according to BMI were (3.5%) of class overweight. Significant association between DM and BMI was (r = 0.357, P < 0.001). Liver MRI T2* has significant correlation with serum ferritin, but cardiac MRI T2* was poorly correlated. Association between liver and cardiac MRI T2* was not found. Conclusion: Age group (27–< 32) years-old and ferritin > 2500 ng/mL should be properly treated immediately. The serum ferritin and BMI of class "overweight" were risk factors for DM. Factors such as diet should be followed. Serum ferritin can be used for estimating liver iron content for economic factors. But cardiac MRI T2* must be performed for evaluating cardiac iron accurately. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
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