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Abstract Background Pulmonary embolism (PE) is a lethal type of venous thromboembolic disease. Right ventricular (RV) failure is not an uncommon complication of PE leading to higher adverse outcomes. The tricuspid annular peak systolic excursion/pulmonary artery systolic pressure (TAPSE/PASP) ratio as a surrogate for RV–pulmonary artery coupling has proven to be among the predictor of clinical outcomes in multiple patient groups. We evaluated in this study the role of TAPSE/PASP ratio in predicting adverse clinical outcomes in patients with acute PE. Results Among patients with established diagnosis of acute PE admitted to the coronary care unit, echocardiography was done within 12 h of admission and TAPSE/PASP ratio was calculated. The patients were followed during hospitalization and after discharge for 3 months for development of adverse outcomes including rehospitalization due to heart failure, recurrent PE and mortality. A total of fifty-five consecutive patients were recruited with mean age 58.3 ± 6.9 years and nearly equal male-to-female ratio. The mean ratio of TAPSE/PASP was 0.479 ± 0.206. In-hospital and 3-month follow-up showed that 10.9% needed rehospitalization with heart failure, 14.5% developed recurrent pulmonary embolism, and mortality was 9.1%. TAPSE/PASP ratio was significantly lower among the patients who developed adverse outcomes. TAPSE/PASP ratio was among the independent predictors of rehospitalization with heart failure, recurrent pulmonary embolism but not mortality at 3-month follow-up. TAPSE/PASP ratio predicted rehospitalization with heart failure at a cutoff point ≤ 0.325, with 100% sensitivity and 79.6% specificity, and predicted recurrent pulmonary embolism at a cutoff point ≤ 0.325, with 75% sensitivity and 78.7% specificity. Conclusion TAPSE/PASP ratio is a noninvasive tool that can predict the development of early adverse outcomes in patients with acute PE including rehospitalization with heart failure and recurrent pulmonary embolism.

Abstract Background Instantaneous wave-free ratio (iwFR) is a well-validated method for functional evaluation of intermediate coronary lesions. A recently developed Murray law-based QFR (µQFR) allows wire-free FFR estimation using a high-quality single angiographic projection. We aim to determine the diagnostic accuracy of µQFR as compared to wire-based iwFR for physiological assessment of coronary lesions in a sample of Egyptian patients. Results Over a one-year period, patients who previously underwent iwFR assessment of an intermediate coronary stenosis (40–90%) were retrospectively included. μQFR analysis was then performed offline using a dedicated artificial intelligence (AI)-aided computation software. All the measurements were performed blinded to iwFR results, and the agreement between iwFR and μQFR values was tested. Forty-nine patients (mean age 57.9 ± 9 years, 72.9% males) were included. Mean value of iwFR and μQFR was 0.90 ± 0.075 and 0.79 ± 0.129, respectively. There was a significant moderate positive linear correlation between μQFR and iwFR (r = 0.47, p = 0.001; 95% CI 0.22–0.68) with moderate-to-substantial agreement between the two methods (Kappa 0.6). In assessing the diagnostic accuracy of μQFR, the receiver operating characteristic (ROC) curve yielded an area under the curve (AUC) of 0.84 (95% CI 0.717–0.962) for predicting functionally significant lesions defined as iwFR

Abstract Background The reported prevalence of patent foramen ovale (PFO) in the general population is variable. It ranges between 8.6 and 42% according to the population studied and the imaging technique used. We aim to prospectively assess the prevalence and characteristics of PFO and interatrial septum (IAS) abnormalities as well as the related clinical manifestations in a sample of Egyptian population. Results This study comprised 1000 patients who were referred for CT coronary angiography (CTCA). Mean age was 52.5 ± 10.9 years. The prevalence of PFO among the studied population was 16.3%; closed PFO (grade I) 44.2%, open PFO (grade II) 50.9%, and open PFO with jet (grade III) 4.9%. Anatomical high-risk PFO features—defined as the presence of at least 2 or more of the following (diameter ≥ 2 mm, length ≥ 10 mm, septal aneurysm “ASA”, or redundant septum)—were found in 51.5% of PFOs’ population. Other IAS abnormalities as redundant septum (8.6%), ASA (5.3%), Bachmann’s bundle (4.5%), microaneurysm (2.6%), and atrial septal defect (ASD) (0.4%) were detected. There was a lower rate of coexistence of ASA with PFO (p = 0.031). Syncope was significantly higher in patients with PFO compared to those without PFO (6.7% vs. 1.6%, p = 0.001). Stroke, transient ischaemic attacks (TIA), and dizziness were similar in both groups. TIA, dizziness, and syncope were significantly higher in patients with IAS abnormalities including PFO compared to those without IAS abnormalities. Syncope was also significantly higher in PFO with high-risk anatomical features compared to those with non-high-risk PFO population (p = 0.02). Conclusion The prevalence of PFO in our study was approximately 16.3%, almost half of them showed anatomical high-risk features for stroke. Dizziness, syncope and TIA were significantly higher in patients with IAS abnormalities including PFO.

AbstractPurpose Epicardial fat thickness is an interesting parameter of early atherosclerosis. We prospectively assessed whether weight loss following laparoscopic sleeve gastrectomy (LSG) leads to a significant reduction in the epicardial fat thickness (EFT) and the correlation between the decline in the epicardial fat thickness with other clinical parameters.Methods A prospective analysis of 98 cases that were scheduled to undergo LSG and followed up for 12 months was conducted. EFT was assessed using two-dimensional (2 D) echocardiography.Results A total of 98 cases and 70 controls were enrolled. EFT demonstrated a significant reduction at follow-up in the whole group (median 8.9 (1.95) versus 7.65 (1.67) mm, respectively). The degree of reduction was higher in the LSG cohort compared to control cohort 1.3 (0.4) versus 1 (0.4), respectively; p

Abstract Aims Worsening of renal function (WRF) is a common complication in patients with acute decompensated heart failure (ADHF). We aimed to evaluate the role of intrarenal Doppler ultrasound (IRD) in the early prediction of WRF in this patient group. Methods and results Among 90 patients (age: 57.5 ± 11.1 years; 62% male) hospitalized with ADHF, resistivity index (RI), acceleration time (AT), and pulsatility index (PI) were measured on admission and at 24 and 72 h. WRF was defined as increased serum creatinine ≥0.3 mg/dL from baseline. Adverse clinical outcomes were defined as the composite of death, use of vasopressors, and need for ultrafiltration for refractory oedema. WRF developed in 40% of patients. Mean values of renal AT, RI, and PI on admission were 59.7 ± 15, 0.717 ± 0.08, and 1.5 ± 0.48 ms, respectively. At 24 h, there was significant decrease in AT (to 56.7 ± 10 ms, P = 0.02) and renal RI (to 0.732 ± 0.07; P

Life cycle assessment (LCA) is a widely recognized tool for environmental assessment, which has experienced a strong development both in methodology and applications. This paper aimed to perform a bibliometric analysis of LCA research during 2000-2022, considering publication types, publication trends, subject categories, journals, institutions, countries, and author keywords. Social Network Analysis was applied to recognize mapping trends, status, and hot spots in LCA research and to discover co-authorship relations and international collaborations among countries worldwide. The results of this study showed that the number of LCA publications has remarkably increased by more than tenfold over the study period. The United States, with 5885 publications (17.3%), was the most productive country in terms of the number of publications. The keywords "sustainability," "environmental impact," "carbon footprint," "circular economy," "recycling," and "climate change" were the most occurred keywords in the literature. The keyword "sustainability," growing from 221 in 2000-2011 to 2013 in 2011-2022, was the most trending keyword. The keywords "water footprint," "biogas," and "GHG emissions" exhibited the highest increase in frequency, with growth rates of 18.5, 11.2, and 7.1 times, respectively. The outcomes of this study showed the cumulative progression of the literature, thereby establishing a framework for future works in LCA research. [ABSTRACT FROM AUTHOR]

HLA-DR/DQ haplotypes largely define genetic susceptibility to type 1 diabetes (T1D). The DQB1*06:02-positive haplotype (DR15-DQ602) common in individuals of European ancestry is very rare among children with T1D. Among 4,490 children with T1D in the Finnish Pediatric Diabetes Register, 57 (1.3%) case patients with DQB1*06:02 were identified, in comparison with 26.1% of affected family-based association control participants. There were no differences between DQB1*06:02-positive and -negative children with T1D regarding sex, age, islet autoantibody distribution, or autoantibody levels, but significant differences were seen in the frequency of second class II HLA haplotypes. The most prevalent haplotype present with DQB1*06:02 was DRB1*04:04-DQA1*03-DQB1*03:02, which was found in 27 (47.4%) of 57 children, compared with only 797 (18.0%) of 4,433 among DQB1*06:02-negative case patients (P < 0.001 by χ2 test). The other common risk-associated haplotypes, DRB1*04:01-DQA1*03-DQB1*03:02 and (DR3)-DQA1*05-DQB1*02, were less prevalent in DQB1*06:02-positive versus DQB1*06:02-negative children (P < 0.001). HLA-B allele frequencies did not differ by DQB1*06:02 haplotype between children with T1D and control participants or by DRB1*04:04-DQA1*03-DQB1*03:02 haplotype between DQB1*06:02-positive and -negative children with T1D. The increased frequency of the DRB1*04:04 allele among DQB1*06:02-positive case patients may indicate a preferential ability of the DR404 molecule to present islet antigen epitopes despite competition by DQ602. Article Highlights: The common HLA-DQB1*06:02 allele is strongly protective against type 1 diabetes (T1D), although few DQB1*06:02-positive individuals have been found. We compared the distribution of the second class II haplotypes in DQB1*06:02-positive children with T1D with the distribution of haplotypes found in in other children with T1D. HLA-DRB1*04:04-DQA1*03-DQB1*03:02 was the most common second haplotype in DQB1*06:02-positive children with T1D, whereas DRB1*04:01-DQA1*03-DQB1*03:02 was most frequent in other children with T1D. This finding suggests that the islet-specific epitopes presented by DRB1*04:04 can more efficiently avoid binding to DQB1*06:02 than epitopes presented by other risk-associated haplotypes. [ABSTRACT FROM AUTHOR]

Introduction: In recent decades, the rate of infection with dengue virus (DENV) has risen significantly, now affecting nearly 400 million individuals annually. Dengue fever among humans is caused via specific mosquito vectors bites. Sporadic cases have been reported in Egypt. The goal of this study was to identify the serotype of the DENV outbreak in both human and mosquito vector along the coast of the Red Sea, Upper Egypt, in 2017. Identification of the serotype of the virus may help identify its source and assist in applying epidemiological and control measures. Materials and Methods: The current study was carried out in El Quseir City, Red Sea Governorate, Upper Egypt, on 144 patients complaining of symptoms indicative of dengue fever at the time of the 2017 Egypt outbreak. Human blood samples and the mosquito reservoirs were identified as having dengue virus infection serologically and molecularly. Results: Overall, 97 (67.4%) patients were positive for dengue virus IgM antibodies. Molecular examination of the human samples and pools of mosquitoes revealed that DENV-2 virus was the serotype responsible for the outbreak. Only one pool of female mosquitoes containing Aedes aegypti was infected with dengue fever virus (DENV-2). Conclusion: This was the first serotyping of the DENV responsible for dengue virus outbreak in Egypt in 2017. Determining the serotype of dengue virus can help to avoid and monitor outbreaks. The serotype identified in this study was DENV-2, while DENV-1 was the serotype found in the previous outbreak in 2015 in the province of Assiut. This study thus raises concerns that a new dengue serotype could have been introduced into Egypt. It is necessary for a comprehensive risk assessment to be carried out in the country, including an entomological survey, to assess the presence and potential geographical expansion of mosquito vectors there. [ABSTRACT FROM AUTHOR]

Due to the higher production cost of the monolithic carbide tools as well as their brittle nature, cemented carbides such as WC-Co are frequently joined to tool steel. To overcome the joining complications that arise due to notable differences in thermal expansions between the components and the poor wettability, various investigators have used copper-based and silver-based filler metals to dissimilarly braze the cemented carbides to steels. However, researchers do not agree about the selection of filler material. This research investigates the use of pure copper, brass, and silver-based filler metals to join the WC-Co cemented carbide to AISI 1045 steel. In this regard, microstructural features and mechanical properties including microhardness and shear strength were studied. The results indicate the formation of Cu(Fe,Co) solid solution and η carbides at the joint interfaces as well as the development of various precipitated phases in the joint area comprising Fe-Zn and Co-Zn intermetallic compounds. The reaction layers at both sides of the joints accompanied by cobalt-depleted zone on the hard metal side were observed. While using the α−β brass interlayer, the increase in hardness of the joint area through the presence of (Cu,Zn) solid solution compared to pure copper, the joint shear strength was enhanced from 161 to 173 MPa. On the other hand, the utilization of silver-based filler alloy with a distribution of hard copper-rich solid solution phase (182 HV) embedded in a silver-rich ductile matrix (88 HV), presenting a dispersion hardening effect, improved the shear strength of the joint to 203 MPa.

Although the bibliometric method has been widely used in a large number of sciences, no bibliometric study has been presented on the VOSviewer application as the most prominent software in this area. This study aimed to achieve a bibliometric analysis of research using VOSviewer, emphasizing "environment" and "energy" areas. Various features, including language, chronological trends, source types, subject categories, countries, source titles, affiliations, authors, and author keywords were systematically investigated. The countries' cooperation, authors' collaborations based on citations, the author keywords' occurrences were constructed, visualized, and assessed through the VOSviewer. The study indicated that the number of VOSviewer-related publications has grown significantly. More than 97% of the total publication were journal articles and conference papers, while all publications in the mentioned fields have been in the form of articles. China was the leading country in publications, followed by Spain, Brazil, Italy, and the UK. As well, the USA and Spain had a large number of cooperation with other countries. Li, J., and Li, H. from China were the most cited authors. "Energy", and "Environmental Science" were widely used areas in the most productive journals, as "Sustainability" published the most VOSviewer articles, followed by "International Journal of Environmental Research And Public Health" and "Journal of Cleaner Production". Among the author keywords, "sustainability", "sustainable development", and "circular economy" could be recognized. Based on database comparison, the number of publications using the "Web of Science" database is higher than "Scopus". However, the increase of articles published in the "Scopus" database is more. [ABSTRACT FROM AUTHOR]

Carbon fibre-reinforced polymer (CFRP) was introduced over three decades ago to the field of structural engineering. The goal of this study is to investigate the effects of different types of sands and CFRP on the interface properties of sand and CFRP using the direct shear test (DST). Various type of soils including poorly graded sand (SP), silty sand (SM) and Ottawa sand (OTS) with different moisture conditions (dry and saturate) were considered. To increase the surface roughness, a layer of sand was placed on saturated carbon fibre during the curing period (SPSCFRP) and the normal stress was applied to it. Additionally, the effect of the fibre orientation and the normal stresses on CFRP-sand during the curing time was investigated. Based on the results, the interface behaviour between sand and CFRP depended on surface roughness, fibre orientation, the normal stress level and moisture condition. The results indicated that a reduction in moisture content caused an increase in the interface friction angle of specimens. Moreover, interface behaviour between CFRP-sand compared with interface behaviour between SPSCFRP and sand. Dissipated energy values obtained from DST. Results revealed that the dissipated energy under dry condition was higher than the saturated one. [ABSTRACT FROM AUTHOR]

In this research, the effect of RSW parameters including current intensity, welding time and welding force (coded by A, B and C) on the radius, thickness and area of ​​the nugget and the radius of the HAZ of TRIP steel joints was investigated by DOE and RSM. A 3D coupled thermal-electrical-structural FEM was used to model RSW. To validate the FE model, two TRIP steel sheets were welded experimentally. During welding, the temperature was measured and the results were compared with the FE results and a good agreement was obtained. The boundaries of the welding zones were determined according to the critical temperatures and the responses in all samples were calculated. Using analysis of variance, direct, quadratic and interaction effects of parameters on the responses were studied and a mathematical model was obtained for each response. The direct linear effects of all parameters on all responses were significant. But among the interaction effects, the effect of B×C on the nugget radius, the effect of A×B on the nugget thickness, the effect of A×B on the nugget area and the effects of A×B and B×C on the HAZ radius were significant. Also, current intensity had the greatest effect on all responses.

Introduction: Schistosomiasis is an important neglected tropical disease (NTD) in several developing countries. Praziquantel is the principle and efficacious chemotherapeutic agent that has been used to treat schistosomiasis for decades. Unfortunately, emerging resistance to praziquantel with accompanying reduced efficacy is reported in some localities. Hence, genetic diversity among parasite populations is of significant interest in assessing the effects of selective pressure generated by praziquantel therapy that might result in encouraging the emergence of new genotypes that are either non-susceptible or drug-resistant. The present study aimed to investigate the genetic diversity of Schistosoma haematobium among human populations using the RAPD technique to help clarify disease epidemiology and transmission. Materials and Methods: S. haematobium eggs were isolated from 50 of 134 patients from four different localities in Qena Governorate, Upper Egypt. These patients complained of terminal hematuria and burning micturition. Samples were used for molecular analysis using RAPD-PCR primers (A02, A07, A09, A10). Results: Twenty S. haematobium isolates (40%) were amplified using the selected RAPD primers. Amplification patterns of these isolates showed distinct variation in the size and number of amplified fragments, indicating high genetic variation among these isolates. Conclusion: To the best of our knowledge, this study is the first to characterize the genetic diversity of S. haematobium in human populations in Upper Egypt. Future studies on a larger geographic scale involving many districts in Upper Egypt should be encouraged. Information from such a study would provide better insight into clonal lineages of S. haematobium in this endemic area. In turn, understanding transmission of the parasite may have a major role in establishing control strategies for urogenital schistosomiasis in Upper Egypt. [ABSTRACT FROM AUTHOR]

The diffusion couple method is an appreciated experimental approach in taking in phase relations in multi-component systems. To investigate the growth mechanism of the phases and the diffusion of the components, Ni–Ti diffusion couple experiments are carried out at four different temperatures of 750, 800, 850, and 900 °C up to 24 h. Microstructural observations using scanning electron microscopy equipped with energy dispersive spectroscopy at the interface of the nickel-titanium indicates formation of three major intermetallic compounds by the sequence of NiTi2, Ni3Ti and NiTi. Using typical marker tests with incremental diffusion couples, data about mobilities of elemental type intermetallic phase media can be attained, and tracer diffusion coefficients can be presumed. By using of cerium oxide particles as an inert marker, it is shown that the diffusion of nickel atoms toward titanium is faster than the diffusion of titanium atoms through the compound layers. The marker plane is detected at the interface of Ni/Ni3Ti.The ratio of intrinsic diffusivities indicates that Ni is the predominant diffusing element in this system. The activation energies for the formation and growth of NiTi2, NiTi, Ni3Ti, and the total interfacial layers are found to be respectively 204, 151, 38, and 154 kJ/mol. In addition, the integrated diffusion coefficients are calculated by use of Wagner method. The activation energies for the integrated diffusion coefficient of NiTi2, NiTi and Ni3Ti are calculated as 168,149 and 78 kJ/mol, respectively.

Purpose: To determine the bacteriological pattern and antibiotic susceptibility of bacterial isolates causing neonatal sepsis in Qena University Hospitals and compare polymerase chain reaction (PCR) and blood culture results in a trial for rapid diagnosis. Patients and methods: Blood samples from 75 clinically suspected cases of neonatal sepsis were subjected to identification of bacteria and determination of their antibiotic sensitivity through blood culture, and rapid detection of 16S rRNA and the uidA gene (to confirm the presence of E. coli) by PCR from extracted bacterial DNA. Results: Most patients were preterm (64%) and low birth weight (LBW) (68%). In total, 42.7% presented with early onset sepsis (EOS). LBW was significantly associated with EOS (P-value=0.03). Although the blood culture and PCR results were similar in EOS, the PCR results were significantly higher than those of blood culture in detecting bacteria (85.3% vs 68%, respectively, P-value=0.001). Blood culture showed 100% specificity. The most common pathogen was E. coli (86.2%) in EOS and Staphylococcus spp. (45.5%) in late-onset sepsis (LOS) (P-value=0.001 and 0.02, respectively). The most effective antibiotics against Gram-negative bacteria were ofloxacin, ciprofloxacin, imipenem, and amikacin, while vancomycin, oxacillin, and imipenem were the most effective antibiotics against Gram-positive bacteria. Conclusion: EOS was mainly caused by E. coli, while LOS was mainly caused by Staphylococcus spp. The 16S rRNA PCR showed higher sensitivity with rapid and accurate diagnosis. Blood culture is the most suitable method for antimicrobial sensitivity testing. [ABSTRACT FROM AUTHOR]

Purpose: We aimed to examine the possible association role of vitamin D and vitamin D receptor (VDR) single nucleotide polymorphisms (SNPs) in type 1 diabetes mellitus (T1DM) development, glycemic control and complications among a cohort of Egyptian children. Subjects and methods: A prospective case-control study has been conducted on 50 Egyptian children with T1DM who were comparable with 50 controls. Vitamin D and HbA1c were measured. VDR-SNPs [ApaI (rs7975232), TaqI (rs731236) and BsmI (rs1544410)] detection was done by polymerase chain reaction through restriction fragment length polymorphism (PCR-RFLP) technique. Vitamin D supplements were given to the included T1DM children with low vitamin D and reassessments of both HbA1c% and 25(OH)D serum levels were performed in those children three months later. Results: Eighty percent of the included diabetic patients have poor glycemic control. Vitamin D was deficient in 68% and insufficient in 16% of diabetic patients. Significant improvements in both vitamin D and glycemic status among T1DM children, who have low vitamin D and received vitamin D supplementations. There were significantly negative correlations between serum levels of vitamin D with both HbA1c % (r= –0.358, P˂0.05) and daily insulin dose (r=−0.473, P˂0.05). Compared with controls, T1DM children presented more commonly with ApaI a allele (OR: 2.87; 95%CI: 1.39–5.91, P˂0.05) and BsmI b allele (OR: 4.38; 95%CI: 2.30–8.33, P˂0.05). TaqI t allele wasn't significantly differing among patients and controls (P˃0.05). Aa+aa and Bb+bb genotypes were significantly higher among T1DM vs the controls (OR: 3.08;, 95%CI: 1.33–7.15, P˂0.05 and OR: 9.33; 95%CI: 3.61–24.17, P˂0.05respectively). Conclusion: ApaI and BsmI were associated with risk of T1DM development among Egyptian children. Low vitamin D status was frequently occurring among T1DM with significant improvement in the glycemic control of such children when adding vitamin D supplements to the standard insulin therapy. [ABSTRACT FROM AUTHOR]

Polypropylene (PP)/acrylonitrile butadiene rubber (NBR) composite plates reinforced with halloysite nanotubes (HNTs) were manufactured in the presence of dual compatibilizers: PP-grafted maleic anhydride (PP-g-MA) and styrene ethylene butylene styrene-grafted maleic anhydride (SEBS-g-MA). The mechanical characteristics and microstructure of the PP/NBR/HNT nanocomposites were investigated as a function of NBR content (10, 20, and 30 wt.%) and HNTs content (3, 5, and 7 wt.%). The results demonstrated that the rubber particles were well dispersed over the PP matrix and that the HNTs were partly agglomerated at contents above 5%. Friction stir welding (FSW) was used to join the nanocomposite plates. A significant reduction in scattered NBR droplet size was seen in the FS-welded specimens containing 80/20 (wt/wt) PP/NBR composites in the presence of a dual compatibilizer. Considerable improvement in particle dispersion was observed in the case of PP/NBR blends filled 80/20 (wt/wt) with HNTs joined using FSW, leading to enhanced mechanical properties in the joints. This was due to the stirring action of the FSW tool. Suitable agreement between anticipated and confirmed values was observed in experiments.

As glass epoxy composites have special properties, they are used in different structures. Health monitoring of this kind of composite is very important due to its use in many industries. Acoustic emission technique is one of the best methods for health monitoring. Since flexural loading is widespread in utilization of this type of composite, in this research acoustic emission method was used to monitor and check the different failure mechanisms of glass epoxy composite flexural loading. In order to determine different failure mechanisms, the wavelet transform and Choi-Williams transform analysis was used to process acoustic signals. Three types of dominant failure mechanisms (matrix fracture, debonding and fiber breakage) in this composite were identified and the frequency ranges corresponding to these failure mechanisms were determined. Wavelet transform results showed that, this three type of dominant failure mechanisms (matrix fracture, debonding and fiber breakage) in flexural loading have frequency range of 62.5–125 kHz, 125–187.5 kHz and 187.5–250 kHz respectively. Also energy distribution of each frequency ranges obtained and fitted with fracture mechanisms. Finally the observations of scanning electron microscope from fracture surface of specimen validated the obtained results. This research showed the possibility of acoustic emission technique as a monitoring tool of glass/epoxy composite in flexural failure. Keywords: Failure mechanisms, Wavelet, Energy range, Flexural failure, Structural health monitoring

Binder-jet 3D-printing is a powder bed additive manufacturing process that selectively deposits binder on a powder bed layer-by-layer to fabricate a green part followed by a sintering step for densification. Gas-atomized alloy 625 powders of three different powder size distributions including 16–63 μm (full), 16–25 μm (fine) and 53–63 μm (coarse) powders were 3D-printed with green relative bulk densities of about 52%, 45% and 48%, respectively, followed by vacuum-sintering at temperatures between 1225 and 1300 °C for 4 h. For the fine and coarse powders with narrow size distribution, printing defects with high pore coordination numbers may form during the binder jetting process which cannot be removed during the final sintering stage even during supersolidus liquid phase sintering. However, the full particle size distribution gave higher green density with fewer large, highly coordinated pores so supersolidus liquid phase sintering was able to reach near-full density. Additionally, the fine powders gave non-uniform, anisotropic linear shrinkage during sintering which is unfavorable for designing complex structures. The results suggest that particle size distribution is a determining factor for supersolidus liquid phase sintering, pore removal and final microstructure, if printing parameters such as layer thickness, binder saturation, printhead binder droplet size and drying time are similar. Keywords: Additive manufacturing, Solid-state sintering, Supersolidus liquid phase sintering, Particle size distribution, Microstructure evolution, Inconel 625

Lithium (Li) is a metal with critical therapeutic properties ranging from the treatment of bipolar depression to antibacterial, anticancer, antiviral and pro-regenerative effects. This element can be incorporated into the structure of various biomaterials through the inclusion of Li chloride/carbonate into polymeric matrices or being doped in bioceramics. The biocompatibility and multifunctionality of Li-doped bioceramics present many opportunities for biomedical researchers and clinicians. Li-doped bioceramics (capable of immunomodulation) have been used extensively for bone and tooth regeneration, and they have great potential for cartilage/nerve regeneration, osteochondral repair, and wound healing. The synergistic effect of Li in combination with other anticancer drugs as well as the anticancer properties of Li underline the rationale that bioceramics doped with Li may be impactful in cancer treatments. The role of Li in autophagy may explain its impact in regenerative, antiviral, and anticancer research. The combination of Li-doped bioceramics with polymers can provide new biomaterials with suitable flexibility, especially as bio-ink used in 3D printing for clinical applications of tissue engineering. Such Li-doped biomaterials have significant clinical potential in the foreseeable future.

Ni–Mn–Ga Heusler alloys are multifunctional materials that demonstrate macroscopic strain under an externally applied magnetic field through the motion of martensite twin boundaries within the microstructure. This study sought to comprehensively characterize the microstructural, mechanical, thermal, and magnetic properties near the solidus in binder-jet 3D printed 14M Ni50Mn30Ga20. Neutron diffraction data were analyzed to identify the martensite modulation and observe the grain size evolution in samples sintered at temperatures of 1080 °C and 1090 °C. Large clusters of high neutron-count pixels in samples sintered at 1090 °C were identified, suggesting Bragg diffraction of large grains (near doubling in size) compared to 1080 °C sintered samples. The grain size was confirmed through quantitative stereology of polished surfaces for differently sintered and heat-treated samples. Nanoindentation testing revealed a greater resistance to plasticity and a larger elastic modulus in 1090 °C sintered samples (relative density ~95%) compared to the samples sintered at 1080 °C (relative density ~80%). Martensitic transformation temperatures were lower for samples sintered at 1090 °C than 1080 °C, though a further heat treatment step could be added to tailor the transformation temperature. Microstructurally, twin variants ≤10 μm in width were observed and the presence of magnetic anisotropy was confirmed through magnetic force microscopy. This study indicates that a 10 °C sintering temperature difference can largely affect the microstructure and mechanical properties (including elastic modulus and hardness) while still allowing for the presence of magnetic twin variants in the resulting modulated martensite.

Binder jet printing (BJP) is a metal additive manufacturing method that manufactures parts with complex geometry by depositing powder layer-by-layer, selectively joining particles in each layer with a polymeric binder and finally curing the binder. After the printing process, the parts still in the powder bed must be sintered to achieve full densification (A. Mostafaei, Y. Behnamian, Y.L. Krimer, E.L. Stevens, J.L. Luo, M. Chmielus, 2016; A. Mostafaei, E. Stevens, E. Hughes, S. Biery, C. Hilla, M. Chmielus, 2016; A. Mostafaei, Y. Behnamian, Y.L. Krimer, E.L. Stevens, J.L. Luo, M. Chmielus, 2016) [1–3]. The collected data presents the characterization of the as-received gas- and water-atomized alloy 625 powders, BJP processing parameters and density of the sintered samples. The effect of sintering temperatures on the microstructure and the relative density of binder jet printed parts made from differently atomized nickel-based superalloy 625 powders are briefly compared in this paper. Detailed data can be found in the original published papers by authors in (A. Mostafaei, J. Toman, E.L. Stevens, E.T. Hughes, Y.L. Krimer, M. Chmielus, 2017) [4].

A full factorial design of experiment was applied running 36 experiments to investigate the effects of milling parameters including cutting speed with three levels of 62.83, 94.24 and 125.66 m/min, feed rate with three levels of 0.1, 0.2 and 0.3 mm/tooth, cutting depth with two levels of 0.5 and 1 mm and machining media with two levels, on surface integration properties of magnesium AZ91C alloy such as grain size, secondary phase percent, surface microhardness and surface roughness. In all cases, a fine grained surface with higher secondary phase sediment and microhardness obtained comparing the raw material. According to analysis of variance results, the most effective parameter on grain size, secondary phase percent and microhardness was cutting depth and the most effective parameter on surface roughness was feed rate. although the grain size in all machined samples was smaller than that of the raw material but due to the dual effect of cryogenic conditions, which both cool and lubricate and reduce the temperature and strain rate at the same time, the direct effect of this parameter on grain size was not significant. Also, the all interaction effects of parameters on grain size and microhardness were significant.

Powder bed binder jet printing (BJP) is an additive manufacturing method in which powder is deposited layer-by-layer and selectively joined in each layer with binder. The data presented here relates to the characterization of the as-received feedstock powder, BJP processing parameters, sample preparation and sintering profile (“Effect of solutionizing and aging on the microstructure and mechanical properties of powder bed binder jet printed nickel-based superalloy 625” (A. Mostafaei, Y. Behnamian, Y.L. Krimer, E.L. Stevens, J.L. Luo, M. Chmielus, 2016) [1], “Powder bed binder jet printed alloy 625: densification, microstructure and mechanical properties” (A. Mostafaei, E. Stevens, E. Hughes, S. Biery, C. Hilla, M. Chmielus, 2016) [2]). The data presented here relates to the characterization of the as-received feedstock powder, BJP processing parameters, sample preparation and sintering profile. Effect of post heat treatments including solutionizing and aging on the microstructure and mechanical properties of powder bed binder jet printed nickel-based superalloy 625 were compared to that of sintered samples.

In this study, thermoplastic polyolefin elastomeric (TPO) nanocomposites were fabricated by friction stir processing. The effect of different pin geometries on clay dispersion and mechanical properties of the TPO nanocomposite reinforced with 3% wt nanoclay has been first investigated. The optimum pin geometry namely threaded cylindrical pin was then used to fabricate the nanocomposites containing 3, 5 and 7 wt% nanoclay. The results showed that increase in the clay content increased the tensile strength and tensile modulus of the nanocomposite from 15.8 to 22.76 MPa and 568 to 751 MPa, respectively. The experimental stress – strain curves of nanocomposites were compared with eight constitutive models including Mooney – Rivlin, the second-order polynomial, Neo – Hookean, Yeoh, Arruda – Boyce, Van der Waals and the third- and sixth-order Ogden. The comparisons showed that there was an agreement between the experimental data and the sixth-order Ogden model. Three micromechanical models Halpin – Tsai, inverse rule of mixture and linear rule of mixture were applied to investigate the Young’s modulus of nanocomposites. Because of the significant difference between the Young’s modulus obtained from these models and the ones obtained from experimental data, a modifying factor was used to improve the theoretical predictions obtained from the models.

Alignment among all the strategies of different sectors in every organization is now being one of the challenges of today’s organizational management. This paper aims to develop an integrated model of manufacturing strategy in coordination with marketing and business strategies. According to the obtained results, the mentioned coordination has a meaningful impact on organizational performance.Our research strategy is survey, and the method used, in terms of results is developmental, descriptive-oriented in terms of goal, and quantitative in terms of data. Measurement tools are questionnaire andinterview. Our statistical population consists of the manufacturing companies admitted in the Tehran Stock Exchange. For measuring the companies’ performances, we calculated the growth rate of sales acquired from financial statements of five years. Descriptive and inferential statistics were used for data analysis. The research results verified the integrated model of manufacturing strategy. Findings also indicate that the companies incorporating a coordinative combination of business, marketing, and manufacturing strategies have a higher performance.

This study was performed to determine the role of autophagy-related 16-like 1 (ATG16L1, rs2241880) and IL10 (rs1800872) polymorphisms in the susceptibility to and early prediction of breast cancer in Egyptians. The study included 50 breast cancer patients and 50 apparently healthy controls. The PCR-RFLP technique was used to detect ATG16L1 (rs2241880) and IL10 (rs1800872) genotypes. IL10 level was determined in serum by ELISA. The mean age of the patients was 54.2 years. Among the patients, 80% had no family history for breast cancer, 70% were postmenopausal, and 72% exhibited grade II tumors. Metastasis was detected in 18% of the patients, and 6% of the cases exhibited triple-negative receptor (TNR) status. In the ATG16LI (rs2241880) gene, the GG genotype frequency was significantly higher in patients than in controls (14% in patients versus 2% in controls, P =0.02), and no metastasis was observed in patients with the AA genotype (P=0.03). In the IL10 (rs1800872) gene, the A allele was observed in 30% of patients and 23% of controls, but the difference was insignificant (P=0.26). Also, the prevalence of the AA genotype was 8% in patients and 4% in controls (P=0.54). Serum IL10 levels were higher in patients than in controls (P < 0.001). Within the patient group, individuals with the IL10 (rs1800872) AA genotype showed significantly higher serum IL10 levels than those with the CC and CA+CC genotypes (P =0.03 and 0.04, respectively). In conclusion, in Egyptian breast cancer patients, the GG genotype of ATG16LI (rs2241880) may be associated with increased disease risk, and the AA genotype could be protective against metastasis., (Copyright© by the Egyptian Association of Immunologists.)

Type 1 diabetes (T1D) is an autoimmune disease associated with multiple genetics and environmental factors. The aim of the study is to determine the frequency of HLA-B*08 and HLA-B*39 and its linkage disequilibrium with common risk haplotypes DR3-DQA1*05-DQB1*02, and DR4-DQA1-03-DQB1*0302 among T1D Egyptian infants. And assess different environmental factors as early exposure to cow's milk, exclusive breast feeding, mode of delivery and low birth weight. Sixty eight diabetic infants and 120 healthy controls were studied. HLA-DQB1, and DQA1 alleles were identified using homogeneous PCR and oligonucleotide hybridization assays. HLA-B*08 and HLA-B*39 genes were identified using multiplex PCR. The results showed that early exposure to cow's milk before 6 months carry a significant risk for T1D (16% in patients versus 6.6%in control group, P value=0.03). HLA-B*08 frequency was significantly higher among T1D infants than in control group (14.5% in diabetic infants versus 5%in control group, P value=0.024). DR3-DQA1*05-DQB1*02, and DR4-DQA1-03-DQB1*0302 were significantly higher in diabetic infants than controls (P value < 0.001 and 0.004 respectively). HLA-B*08 gene was found in (15.5%) of DR3-DQA1*05-DQB1*02 positive cases while in control group it was found in (13.5%) (P value=0.8). In conclusion, HLA-B*08 gene carry a risk for T1D in Egyptian infants, while DR3-DQA1*05-DQB1*02 haplotype lacks linkage disequilibrium with HLA-B*08 among T1D infants. Further studies are needed to determine which HLA-B gene is strongly linked to DR3-DQA1*05-DQB1*02 haplotype in T1D infants other than HLA-B*08 and HLA-B*18., (Copyright© by the Egyptian Association of Immunologists.)