59 results on '"Mahmoud H. Mohamed"'
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2. Finite Element Modeling of the Soil-Nailing Process in Nailed-Soil Slopes
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Mahmoud H. Mohamed, Mohd Ahmed, Javed Mallick, and Saeed AlQadhi
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soil-nailing process ,finite element models ,overburden pressure ,nailed-soil slope ,sandy soil ,nail spacing ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Biology (General) ,QH301-705.5 ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
The finite element technique has been accepted as a tool for modeling geotechnical complex processes. In this study, finite element (FE) modeling of various stages of the soil-nailing process, i.e., construction stages and overburden pressure stages, is carried out considering different soil parameters, simulating with in-house developed laboratory models. The soil-nailing process built in laboratory models is idealized as a plain strain problem and modeled in PLAXIS software. The laboratory models of the soil-nailing process consist of a Perspex sheet box containing a sandy soil slope, a Perspex sheet facing, steel bars as reinforcement and a steel plate as foundation. The stress–strain relationship of the sand is represented by a Hardening-Soil model. The interface at the soil and nail is described by the Coulomb friction model. The behavior of the soil-nailing process, during the construction stage and under varying overburden pressure and varying soil density, are investigated in terms of displacements of slope and stress conditions in slope soil mass. The slope displacements and stress conditions in slope soil mass are all well presented by the FE modeling and compared with laboratory model test data. The sensitivity analysis of the laboratory models’ dimensions is carried out by three-dimensional modeling of the nailed-soil slope. It can be concluded that the developed finite element model has the potential to simulate the performance of a field nailed-soil slope during construction and working stages and could provide guidance for the construction/maintenance of soil-nailed cut slopes in granular soils/weathered rocks.
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- 2023
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3. An Experimental Study of Nailed Soil Slope Models: Effects of Building Foundation and Soil Characteristics
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Mahmoud H. Mohamed, Mohd Ahmed, and Javed Mallick
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soil nailing system ,soil characteristics ,soil slope ,foundation pressure ,nailed soil ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Biology (General) ,QH301-705.5 ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
A soil nailing system is a proven effective and economic method used to stabilize earth slopes from the external (factors increasing the shear stress) and internal (factors decreasing material strength) failure causes. The laboratory models with scales of 1:10 are used to study the behavior of nailed soil slope with different soil and building foundation parameters. The models consist of Perspex strips as facing and steel bars as a nailing system to increase the stability of the soil slope. The models of sand beds are formed using an automatic sand raining system. Devices and instruments are installed to monitor the behavior of soil-nailed slope during and after construction. The effect of the soil type, soil slope angle, foundation width and position on the force mobilized in the nail, lateral displacement of the slope, settlement of the foundation and the earth pressure at the slope face, under and behind the soil mass at various foundation pressures, has been observed. It is found that the increase of soil density reduces both slopes facing displacement and building foundation settlements. The slope face displacement and footing settlement will increase with an increase in the width of the foundation and foundation position near the crest of the slope.
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- 2021
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4. Pullout Behavior of Nail Reinforcement in Nailed Soil Slope
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Mahmoud H. Mohamed, Mohd Ahmed, and Javed Mallick
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soil nailing system ,nails characteristics ,soil slope ,footing pressure ,nails orientation ,pullout force ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Biology (General) ,QH301-705.5 ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
The pullout resistance and displacement performance of reinforcement have significant effects on the safe and economic design of a reinforced-soil system. In this study, the nail pullout tests are conducted to assess the pullout behavior of soil nail reinforcement at different levels in the soil slope of granular materials. The similitude laboratory models of a reinforced soil system with a scale of 1:10 are prepared. The construction sequence used in a full scale slope was precisely followed in the laboratory model. The models consist of a Perspex wall box filled with sand and steel bars as a reinforcement. The models of sand beds are formed using an automatic sand raining system. Devices and instruments are installed to record the nails pullout resistance and displacement. The tests are carried out at variable footing pressures to get the pullout force of the nails based on a strain control technique. The finite element models of nailed soil slope are also analyzed to validate the laboratory model results. It infers from the numerical model results that the laboratory models underestimate the pullout behavior of nail reinforcement in nailed soil slope. The pull-out force in nail reinforcement increases as the displacement increases and then decreases slightly and becomes constant with an increase in displacement in the case of deeper placed nails, but it becomes constant immediately for upper nails.
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- 2021
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5. An Experimental Study of a Nailed Soil Slope: Effects of Surcharge Loading and Nails Characteristics
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Mahmoud H. Mohamed, Mohd Ahmed, Javed Mallick, and Pham V. Hoa
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soil nailing system ,nails characteristics ,soil slope ,surcharge loading ,nails orientation ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Biology (General) ,QH301-705.5 ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
The earth nailing system is a ground improvement technique used to stabilize earth slopes. The behavior of the earth nailing system is dependent on soil and nailing characteristics, such as the spacing between nails, the orientation, length, and method of installation of nails, soil properties, slope height and angle, and surcharge loading, among others. In the present study, a three-dimensional physical model was built to simulate a soil nailed slope with a model scale of 1:10 with various soil nail characteristics. The simulated models consist of Perspex strips as facing and steel bars as a reinforcing system to stabilize the soil slope. Sand beds in the model were formed, using a sand raining system. The performance of nailed soil slope models under three important nails characteristics, i.e., length, spacing and orientation, with varying surcharge loading were studied. It was observed that there is a reduction in the lateral movement of slope and footing settlements with an increase in length. It was found that the slope face horizontal pressure is non-linear with different nail characteristics. The increase in length and inclination of the soil nails decreased the vertical, horizontal stress and footing settlement, while the increase in spacing of the nails increased the vertical and horizontal stress behind the soil mass.
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- 2021
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6. Impact of integrated neuromuscular inhibition technique versus electro-acupuncture stimulation of posterior tibial nerve in males with chronic pelvic pain of myofascial origin
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Mohamed N Selem, Mahmoud H Mohamed, Amany M Abbas, Mohamed Mahmoud Dogha, and Abdelrazak A Ahmed
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Sports ,GV557-1198.995 - Abstract
Article accepted. The article will be published here soon. Pending final quality checks.
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- 2022
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7. Climate Change Impacts, Vulnerabilities and Adaption Measures for Egypt’s Nile Delta
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Abutaleb, Khaled Abubakr Ali, Mohammed, Asmaa Hassan El-Sayed, and Ahmed, Mahmoud H. Mohamed
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- 2018
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8. Indomethacin phonophoresis treatment of chronic nonbacterial prostatitis symptoms: randomized single blinded controlled trial
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Mahmoud H. MOHAMED, Omar M. ELSOGHIER, Atef F. ALI, Abdelrazak A. AHMED, Mahmoud S. ASAL, and Ahmed M. KADRY
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Surgery - Published
- 2023
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9. Evaluation of the efficacy and safety of injectable cross-linked hyaluronic acid compared with mitomycin C in trabeculectomy surgery
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Mahmoud H Mohamed, Mohamed A Abdelshafik, Hany M El Ibiary, and Thanaa H Mohammed
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HealaFlow ,intraocular pressure ,mitomycin C ,Glaucoma ,trabeculectomy ,Ophthalmology ,RE1-994 - Abstract
Background Trabeculectomy has been a gold standard for the treatment of glaucoma for years since its introduction to ophthalmology literature, and the outcome depends mostly on the resulting intraocular pressure (IOP). However, the most common reason for trabeculectomy failure is the development of fibrosis in the conjunctiva and episclera. Thus, glaucoma surgeons are still searching for an optimal substance for the modulation of wound-healing processes. Aim This study was conducted to evaluate the efficacy and safety of injection of cross-linked hyaluronic acid below the scleral flap and under the conjunctiva in trabeculectomy surgery compared with trabeculectomy with mitomycin C (MMC). Patients and methods A total of 24 eyes with primary open-angle glaucoma were included in this study. Patients were divided into two groups: group 1 included 12 eyes that underwent a standardized trabeculectomy surgery supplemented by the injection of cross-linked hyaluronic acid (HealaFlow) below the scleral flap and under the conjunctiva, and group 2 included 12 eyes that underwent a standardized trabeculectomy surgery with the application of MMC. The endpoints for comparison were IOP, success rates, and postoperative complications. Results The results of both groups were comparable, with no statistically significant difference between the two groups as regards IOP, success rates, and postoperative complications. Conclusion Cross-linked sodium hyaluronate (HealaFlow) injectable implant is comparable to MMC for trabeculectomy in terms of IOP-lowering efficacy, success rates, early and mid-term postoperative complications, and tolerability. However, the results should be interpreted cautiously as relevant evidence is still limited, although it is accumulating. Further large-scale, long-term, and well-designed randomized controlled trials are needed.
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- 2015
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10. Histological Evaluation of Bioceramic Sealer Effect in Animal Model after Exposure to Gamma Radiation
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Mervat I Fawzy, Salwa Farid Ahmed, Eman Mohamed Fathy El Maghraby, Amina M. El-Motasem, and Mahmoud H. Mohamed
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business.industry ,Significant difference ,Dentistry ,Right tibia ,Bioceramic ,Bone tissue ,Resorption ,chemistry.chemical_compound ,Animal model ,medicine.anatomical_structure ,chemistry ,Zinc oxide eugenol ,medicine ,General Materials Science ,Tibia ,business - Abstract
Purpose: This study was carried out to evaluate the bone tissue reactions to TotalFill Bioceramic (BC) and Zinc oxide eugenol (ZOE) sealers in gamma-irradiated rats. Materials and methods: In this study, round osseous bone defects were produced in the tibia of 48 male Albino rats (weighing120–150g). Group 1: 9 control non-irradiated rats, Group 2: 9 control irradiated rats, and Group 3: 30 irradiated rats in which the surgical cavities were filled with TotalFill sealer in the right tibia and ZOE in the left tibia. The assigned animals were euthanized on 7, 14, and 28 days. For histopathological examination, tissue sections stained with H & E were examined by a light microscope. Results: At 7 days, the inflammatory response of all studied groups (1, 2, and 3) showed no significant differences (p-0.092). The inflammatory response significantly decreased from 14 to 28 days in all groups, virtually disappeared in the non-irradiated group whilst intense inflammatory infiltrate was still observed in 40% of ZOE group samples with a significant difference between TotalFill vs. ZOE sealer (p- < 0.009). Bone tissue at 14 days showed severe resorption in many areas in irradiated animals that reversed at 28 days. In group 3 treated with TotalFill sealer, fiber condensation was observed in surgical cavity at 14 days which was replaced by trabeculae of bone tissue at 28 days while this event was focal in ZOE sealer. Conclusion: TotalFill sealer proved to be more compatible and has some repair potential than ZOE sealer in irradiated animals
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- 2021
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11. Effect of different periods of irrigation on growth and yield of Cenchrus ciliaris at semi-arid zone of North Darfur State, Sudan
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Mahmoud H. Mohamed and Mohamedalmontasir A. M. Mohamed
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Irrigation ,geography ,geography.geographical_feature_category ,Forage ,Biology ,biology.organism_classification ,Arid ,Pasture ,Agronomy ,Cenchrus ciliaris ,Cenchrus ,Buffel grass ,Dry matter yield ,Irrigation periods ,Plant height ,Poaceae ,Weed - Abstract
Buffel grassCenchrus ciliarisL. (Poaceae) is recognized as one of Australia's most serious environmental weeds. This introduced grass has been associated with loss of native species and alteration of fire regimes. However, it is also highly valued as a pasture species for arid and semi-arid zones and its weed status is highly controversial. This study was conducted at the private farm, Southern part of Alfashir Airport, North Darfur State, Sudan. The objective was to evaluate the effect of different periods of irrigation (DPI) on growth and forage yield ofCenchrus ciliarisduring years of 2018 and 2019. The experiment was laid-out in a randomized complete block design (RCBD) with four replicates, the plot size was 8x5 m. Data collected included plant density, plant ground cover, plant height and dry matter yield. DPI showed significant effect on plant density, plant ground cover, Plant height and dry matter yield. The study showed that irrigation every 7 days (Ir1) was suitable for buffel grass at semi-arid zone in Sudan. Quantitative studies are needed to determine its ecological effects.
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- 2021
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12. Effect of seeding rate on plant performance of Alycicarpus ovalifolius under rain-fed in Semi-arid zone, Sudan
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Mahmoud H. Mohamed and Mohamedalmontasir A. M. Mohamed
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geography ,geography.geographical_feature_category ,Agronomy ,Yield (wine) ,Randomized block design ,Plant density ,Environmental science ,Sowing ,Seeding ,Dry matter ,Forage ,Dry matter yield ,Seed rate ,Vegetation cover ,Pasture - Abstract
This study was conducted at the private farm, Southern part of Alfashir Airport, under the semi-arid condition of North Darfur State, Sudan. The objective was to test the effect of different seed rates (2, 4, 6, and 8 kg/ha) ofAlycicarpus ovalifoliuson plant growth attributes and forage yield, during two consecutive seasons (2017 and 2018) aiming to find the most suitable seed rate under rainfed condition in semi-arid zones to be used in pasture improvement. The experiment was laid-out in a randomized complete block design with four replicates, the plot size was 8x5 m. Data collected included Plant density, plant ground cover and dry matter yield. There were significant effects of seeding rates on plant density, cover and yield. Seed rate of 8kg/ha had highest plant density, cover and yield. But the seed rate of 6kg/ha had the optimum performance, this seed rate was recommended for sowingAlycicarpus ovalifoliusat semi-arid condition for range improvement. Further research work is needed to assess seeding rates across different ecological zones in North Darfur State.
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- 2021
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13. Efficacy of Low Level Laser Therapy versus Therapeutic Ultrasound on Pediatric Post Burn Hypertrophic Scars: A Scar Split Study
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Khaled M. Hassan, Roshdy M. Kamel, El-Sayed S. Mehrem, Mahmoud H. Mohamed, and Hussein G. Mogahed
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Background. The treatment of scars caused by burn is a difficult challenge in developing countries that includes enormous treatment cost. Burn scars tend to get worse with hypertrophy and contracture, leading to limitations of function. This study aimed to compare the efficacy of low-level laser therapy (LLLT) to therapeutic ultrasound (US) on hypertrophic scar in pediatric burns. Methods. 45 children participated in the study, their age ranges from 12 to 15 years of age, suffering from hypertrophic scars. Each scar divided to 2 identical halves. One half received (LLLT) with deep friction massage and the other received therapeutic ultrasound with deep friction massage. Participants were assessed pre & post two months of study by Ultrasonography and Vancouver Scar Scale. Results. Significant improvement was reported in both halves of scar but laser was more effective in decreasing scar height, and lowering Vancouver scale score (p < 0.0001). Conclusion. LLLT and US are proficient and secure modalities for post-burn hypertrophic scars treatment in children.
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- 2019
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14. Evaluation of Shear Bond Strength of Self-Adhering Flowable Composite to Mineral Trioxide Aggregate and Biodentine
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Mohsen Nour El-Din, Asmaa O. Abdel-Rhman, and Mahmoud H. Mohamed
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Mineral trioxide aggregate ,Universal testing machine ,Materials science ,Mold ,Restorative material ,medicine ,Flowable Composite ,General Materials Science ,Composite material ,medicine.disease_cause ,Shear bond ,Crosshead - Abstract
This study aimed to evaluate shear bond strength of mineral trioxide aggregate and biodentine to self-adhering flowable composite. Materials and Methods: eighty Double Split Teflon mold has been prepared with a central hole measuring (3mm in diameter and 2 mm in height) for the mold used for tested materials and (2mm in diameter and in height) for the other mold used for restorative material. The molds were filled with MTA and Biodentine. The mixing material MTA and biodentine applied to its mold (n = 40) and allocated into 2 groups. The specimens will store for72 hours at 37˚C and 100% humidity. After 72 hours, self-adhering flowable composite was applied over MTA and Biodentine with a height and diameter each of 2 mm. The samples were stored in Incubator for 24 hours at 37˚C to enhance setting and then removed from the mold. SBS was measured in a universal testing machine with a load cell of 5kN and a crosshead speed of 0.5 mm/min. Data were analyzed using Graph Pad Instat. A value of P .05).Conclusion Biodentine exhibited higher SBS than MTA; therefore, they could be preferred under flowable composites
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- 2019
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15. Morphoanatomy Studies of the Seed of Lagonychium farctum (Banks & Sol.) Bobr. Growing in Egypt
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Samia M. El-Sayyad, Ashraf Hamed, Mohamed Kamel, and Mahmoud H. Mohamed
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Horticulture ,Perennial plant ,Astringent ,ved/biology ,Prosopis ,Monopodial ,ved/biology.organism_classification_rank.species ,Acacia ,Family Leguminosae ,Biology ,biology.organism_classification ,Shrub - Abstract
Lagonychium farctum (Banks & Sol.) Bobr.is a wild plant growing in the deserts of Upper Egypt as a prickly perennial shrub with monopodial branches. It belongs to family Leguminosae. The plant is usually branching from the base and attains up to 2.5 m in height. It is used in traditional system of medicine as an astringent as well as antidysenteric. The present study investigates various standardized parameters such as macroscopic and microscopic characters which could be helpful in authentication of the seed of Lagonychium farctum. (Banks & Sol.) Bobr.
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- 2021
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16. Morphoanatomy Studies of the Pericarp of Lagonychium Farctum (Banks &Amp; Sol.) Bobr. Growing in Egypt
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Ashraf Hamed, Mahmoud H. Mohamed, Samia M. El-Sayyad, and Mohamed S. Kamel
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- 2021
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17. A proposed soft pneumatic actuator control based on angle estimation from data-driven model
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Shady A. Maged, Mahmoud H Mohamed, Mostafa A. Atalla, Aliaa Rehan Youssef, and Soha H Wagdy
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0209 industrial biotechnology ,Pneumatic actuator ,Computer science ,Mechanical Engineering ,Finite Element Analysis ,Soft robotics ,Electric Conductivity ,02 engineering and technology ,General Medicine ,Bending ,Equipment Design ,Robotics ,Models, Theoretical ,021001 nanoscience & nanotechnology ,Data-driven ,020901 industrial engineering & automation ,Control theory ,0210 nano-technology - Abstract
This article proposes a bending angle controller for soft pneumatic actuators, which could be implemented in soft robotic rehabilitation gloves to assist patients with hand impairment, such as stroke survivors. A data-driven model is used to estimate the angle as pneumatic pressure is applied to the actuator. Furthermore, a finite element model was used to manually optimize the dimensions of the actuator. An embedded flex sensor, which together with a custom testing rig, was used to gather input data for the data-driven model. This rig contains a pneumatic pressure control circuit as well as a camera for image acquisition. Collected data were fed into a linear regression model to predict the data-driven model. Experiments were carried out to validate model’s accuracy as well as modified proportional–integral–derivative controller angle controller performance. The latter controller is designed to mitigate the non-linear response of solenoid valves at different pressures of the actuator. The data-driven model along with the used controller allows more accurate estimation and quicker response.
- Published
- 2020
18. The effect of adding nanosilver particles on push out bond strength and marginal adaptation of endodontic sealers
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Ahmed D Abo Gabal, Saad-Eldin S Al-Ghazawy, Mohammad Sh Aly, and Mahmoud H Mohamed
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Materials science ,Push out ,Bond strength ,General Earth and Planetary Sciences ,Composite material ,Adaptation (computer science) ,General Environmental Science - Published
- 2018
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19. Evaluation of Sealing Ability of Zinc Oxide Nano-Particles Versus Conventional Zinc Oxide in Endodontically Treated Teeth (SEM study)
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Mahmoud H. Mohamed, Rana H. Yaseen, and Mohsen Nour El-Din
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Dye penetration ,Materials science ,Sem study ,chemistry ,Scanning electron microscope ,Stereo microscope ,Group ii ,chemistry.chemical_element ,Nanoparticle ,General Materials Science ,Penetration (firestop) ,Zinc ,Biomedical engineering - Abstract
Purpose: The aim of this study was directed to compare the sealing ability of two materials which are conventional zinc oxide and zinc oxide nanoparticles by measuring microleakage of both materials by stereo microscope and scanning electron microscope. Materials and Methods: Seventy extracted single-rooted human teeth with complete roots, fully formed apices and present a single canal without calcification were used. The crowns of all teeth were removed using a water-cooled, slow-speed diamond precision disc, so as to adjust the length of the roots to a standardized length of 16 mm. The samples were randomly divided into two main groups each one contains 35 samples according to the sealer used as follow: Group I: Conventional zinc oxide sealer & Group II: Zinc oxide nano-particles. Each main group was divided according to evaluation method as follow: Thirty roots were randomly selected from each group for the evaluation of sealing ability using dye penetration method to measure microleakage using stereo microscope and the rest (5 roots) were used in the SEM for representative evaluation of sealing ability of each sealer. In the stereo microscope part, the samples were further divided into three subdivisions according to the time of incubation period one week, one month and three months. Results: As for Dye leakage results of the sealing ability, zno nano-powder showed the statistically significantly highest sealing throughout all periods of examination, While conventional zno showed the statistically significantly lowest sealing throughout all periods of examination. For both zno nano sealer and conventional zinc oxide samples, the highest mean value of leakage was found in (After 3 months) followed by (After 1 week) while the least mean value of leakage was found in (After 1 month). Conclusion: Zinc Oxide nano particles based sealer has higher sealing ability than conventional zinc oxide based sealer.Nano sized particles allow more adaptation and penetration into dentinal tubules than macro sized one.
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- 2018
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20. The effect of incorporating nanosilver particles on antibacterial activity of endodontic sealers
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Saad-Eldin S Al-Ghazawy, Ahmed D Abo Gabal, Mohammad Sh Aly, and Mahmoud H Mohamed
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Chemistry ,General Earth and Planetary Sciences ,Antibacterial activity ,General Environmental Science ,Nuclear chemistry - Published
- 2018
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21. Cinnamyl Alcohol, Benzyl Alcohol, and Flavonoid Glycosides from Sanchezia nobilis
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Mahmoud H. Mohamed, Ahmed E. Abd Ellah, Enaam Y. Backheet, and Khaled M. Mohamed
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chemistry.chemical_classification ,Cinnamyl alcohol ,biology ,Acanthaceae ,Glycoside ,Alcohol ,Plant Science ,General Chemistry ,biology.organism_classification ,General Biochemistry, Genetics and Molecular Biology ,Syringin ,chemistry.chemical_compound ,chemistry ,Glucoside ,Benzyl alcohol ,Organic chemistry ,Sanchezia - Abstract
Further phytochemical investigation of Sanchezia nobilis Hook.f. (Acanthaceae) has afforded nine compounds, the cinnamyl alcohol glycosides: 9-O-β-glucopyranosyl trans-cinnamyl alcohol (1), 9-O-β-xylopyranosyl-(1→6)-O-β-glucopyranosyl-(1→6)-O-β-glucopyranosyl trans-cinnamyl alcohol (2), and syringin (3); the neolignan glucoside: 4-O-β-glucopyranosyl dehydrodiconiferyl alcohol (4); the benzyl alcohol glycosides: 7-O-β-glucopyranosyl benzyl alcohol (5) and 7-O-β-apiofuranosyl-(1→6)-O-β-glucopyranosyl benzyl alcohol (6), together with the flavonoid glycosides: apigenin-7-O-β-glucopyranoside (7), apigenin-7-Ogentiobioside (8), and apigenin-7-O-β-glucuronopyranoside (9). Compound 2 is isolated here for the first time from a natural source, compounds 1, 3, 4, and 8 have been isolated for the first time from the family Acanthaceae, while compounds 5–7 and 9 are reported for the first time from the genus Sanchezia.
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- 2014
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22. 3D-Analysis of Soil-Foundation-Structure Interaction in Layered Soil
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Javed Mallick, Mahmoud H. Mohamed, Mohd. Ahmed, and Mohd. Hasan
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Engineering ,business.industry ,3d analysis ,Component (UML) ,Structure (category theory) ,Foundation (engineering) ,Geotechnical engineering ,business ,Civil engineering ,Finite element method ,Field (geography) ,Parametric statistics - Abstract
The analysis of building structure in contact with soil involves an interactive process of stresses and strains developed within the structure and the soil field. The response of Piled-Raft Foundation system to the structure is very challenging because there is an important interplay between the component of building structure and the soil field. Herein, soil-foundation-structure interaction of buildings founded on Piled-Raft Foundation is evaluated through 3D-Nonlinear Finite Element Analyses using PLAXIS3D FOUNDATION code. The soil settlements and forces demand of the high-rise building structures and foundation is computed. The parametric study affecting the soil-foundation-structure response has been carried out. The parameters such as construction phasing, sequential loading, building aspect ratios, soil failure models and thickness proportion of soil field stiff layer, are considered. It is concluded that the interaction of building foundation-soil field and super-structure has remarkable effect on the structure.
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- 2014
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23. Amelioration of panadol-induced nephrotoxicity via down-regulation of Bax/Bcl2 ratio with some antioxidants
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Nagla F. El Oraby, Mahmoud H. Mohamed, Nawal M. Al-Rasheed, Nouf M. Al-Rasheed, Hanaa M. Ali, Iman H. Hasan, and L. M. Faddah
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medicine.medical_treatment ,Down-Regulation ,Pharmacology ,Antioxidants ,Nephrotoxicity ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,medicine ,Animals ,Antidote ,Thymoquinone ,Acetaminophen ,bcl-2-Associated X Protein ,Kidney ,Biological Products ,Dose-Response Relationship, Drug ,Superoxide Dismutase ,digestive, oral, and skin physiology ,General Medicine ,Glutathione ,Rats ,medicine.anatomical_structure ,chemistry ,Gene Expression Regulation ,Proto-Oncogene Proteins c-bcl-2 ,030220 oncology & carcinogenesis ,Toxicity ,Curcumin ,Uric acid ,Kidney Diseases ,030217 neurology & neurosurgery ,Phytotherapy - Abstract
Background Overdoses of Panadol (APAP) result in hepatic and renal toxicity. Up till now, there is no effective drug for APAP-enhanced nephrotoxicity. This work aims to explore the protective effects of N-acetylcysteine, Thymoquinone (THQ), Curcumin (CUR) and α-Lipoic acid (LA) either alone or in combination against APAP nephrotoxicity, focused on modulation of Bax/Bcl2 pathway. Methods APAP was administrated at a single dose then treated with the fore mentioned antioxidants. Results APAP administration increased serum creatinine, urea, uric acid, tumor necrosis factor-α (TNF-α), and interleukin-1β (IL-1β) levels compared to control group. There is a marked depletion of reduced glutathione (GSH) levels and superoxide dismutase activity (SOD), Bax level was overexpressed, whereas Bcl2 was downregulated in renal tissue. Histopathological examination of the kidney tissue supported these biochemical findings. Treatment with the fore mentioned anti-oxidants ameliorated most of the previous evaluated parameters and returned the kidney nearly to its normal architecture. Conclusion The expression of Bax and Bcl2 is considered one of the mechanisms underlying APAP-induced nephrotoxicity. The administration of THQ along with CUR could be a promising antidote for APAP renal damage through their antioxidant potential.
- Published
- 2017
24. Matsutake alcohol glycosides from Sanchezia nobilis
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Khaled M. Mohamed, Ahmed E. Abd Ellah, Enaam Y. Backheet, and Mahmoud H. Mohamed
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chemistry.chemical_classification ,biology ,Acanthaceae ,Glycoside ,Alcohol ,Plant Science ,General Chemistry ,Matsutake ,biology.organism_classification ,General Biochemistry, Genetics and Molecular Biology ,chemistry.chemical_compound ,chemistry ,Phytochemical ,Sanchezia nobilis ,Botany ,Natural source ,Spectral analysis - Abstract
Phytochemical investigation of the aerial parts of Sanchezia nobilis Hook. (Acanthaceae) has yielded matsutake alcohol (1-octen-3-ol) (1) and four matsutake alcohol glycosides identified as 3-O-β-glucopyranosyl-1-octen-3-ol (2), 3-O-β-glucopyranosyl-(1→6)-β-glucopyranosyl-1-octen-3-ol (3), 3-O-α-arabinopyranosyl-(1→6)-β-glucopyranosyl-1-octen-3-ol (4), and 3-O-α-arabinopyranosyl-(1→6)-β-glucopyranosyl-(1→6)-β-glucopyranosyl-1-octen-3-ol (5). The structures of the isolated compounds were assigned on the basis of different techniques of NMR spectral analysis. Compounds 1–4 have been isolated here for the first time from the family Acanthaceae, while compound 5 is isolated here for the first time from a natural source.
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- 2013
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25. STEROIDAL SAPONINS GLYCOSIDES FROM FRUITS OF SOLANUM NODIFLORUM JACQ
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Hashim A. Hassanean, Mahmoud H. Mohamed, Mohamed A. El-Shanawany, and Alaa M. Nafady
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chemistry.chemical_classification ,Traditional medicine ,chemistry ,biology ,Glycoside ,Solanum ,biology.organism_classification ,Solanaceae - Abstract
From the methanolic extract of the fresh berries of Solanum nodiflorum Jacq. (Solanaceae), Four known steroidal saponins were reported and identified as: (20S)-3s, 16 s -dihydroxy preg-5-ene-22-carboxylic acid-(22,16)-lactone-3-8- chacotrioside (Dumoside 1) and 3 s - dihydroxy pregn-5,16-dien-20-one 3-0- s chacotrioside; (Aethienolone 4), 3-0-a-L- rhamnopyranosyl-(1→2)-a-L-rhamnopyranosyl-(1→4)- s -D-glucopyranosyl (25R,26R)-spirost-5-ene-3s, 17α, 26-triol 2 and s -chacotriosyl-(22,26R)-furost-5-ene-3 s,17α,22,26-tetraol-26-O- s -D-glucopyranoside 3. Their structures were identified by extensive 1H-NMR, 13C-NMR and DEPT-13C-NMR data as well as comparison with reported spectroscopic data.
- Published
- 2012
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26. Fructose-amino acid conjugate and other constituents fromCyperus rotundusL
- Author
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Hanaa M. Sayed, Gamal A. Mohamed, O.R. Omobuwajo, Mahmoud H. Mohamed, Peter Proksch, and Salwa F. Farag
- Subjects
Stereochemistry ,Isovitexin ,Vitexin ,Fructose ,Plant Science ,Biochemistry ,Antioxidants ,Analytical Chemistry ,chemistry.chemical_compound ,Glucosides ,Chlorogenic acid ,Amino Acids ,Apigenin ,Cyperus ,Nuclear Magnetic Resonance, Biomolecular ,Flavonoids ,Orientin ,Plants, Medicinal ,Molecular Structure ,Organic Chemistry ,Stereoisomerism ,chemistry ,Myricetin ,alpha-Amylases ,Luteolin ,Ellagic acid ,Cyperus rotundus - Abstract
Further phytochemical study on the aerial parts of Cyperus rotundus L. led to the isolation of a fructose-amino acid conjugate, N-(1-deoxy-alpha-D-fructos-1-yl)-L-tryptophan (16) and its tautomers, in addition to n-butyl-beta-D-fructopyranoside (1), ethyl-alpha-D-glucopyranoside (2), adenosine (3), (-)-(E)-caffeoylmalic acid (4), vitexin (5), isovitexin (6), orientin (7), epiorientin (8), myricetin 3-O-beta-D-galactopyranoside (9), luteolin 7-O-beta-D-glucuronopyranoside-6''-methyl ester (10), chlorogenic acid (11), luteolin 4'-O-beta-D-glucuronopyranoside (12), luteolin 7-O-beta-D-glucuronopyranoside (13), uridine (14) and ellagic acid (15). Their structures were elucidated on the basis of spectroscopic methods. Additionally, antioxidant and alpha-amylase inhibitory activities of some of the isolated phenolic compounds were carried out.
- Published
- 2008
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27. MACRO- AND MICROMORPHOLOGY OF SANCHEZIA NOBILIS HOOK. CULTIVATED IN EGYPT: LEAF, STEM AND FLOWER
- Author
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Khaled M. Mohamed, Ahmed E. Abd-Ellah, Enaam Y. Backheet, and Mahmoud H. Mohamed
- Subjects
Pharmacology ,Horticulture ,Hook ,Sanchezia nobilis ,Botany ,Pharmaceutical Science ,Biology - Abstract
The detailed macro- and micromorphological characters of the leaf stem and flower of Sanchezia nobilis Hook. were studied with the aim to find out the diagnostic elements of these organs, which facilitate their identification in both entire and powdered forms.
- Published
- 2006
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28. PHYTOCHEMICAL AND BIOLOGICAL INVESTIGATIONS OF FLACOURTIA CATAPHRACTA ROXB. CULTIVATED IN EGYPT
- Author
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Mahmoud H. Mohamed, Ahmed Mohamed ELHussieny Mohamed, Hanaa M. Sayed, and Faten M. Darwish
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Pharmacology ,Stigmasterol ,Chloroform ,Amyrin ,Chromatography ,biology ,Vanillin ,Ethyl acetate ,Pharmaceutical Science ,Flacourtia ,biology.organism_classification ,Protocatechuic acid ,chemistry.chemical_compound ,chemistry ,Phytochemical - Abstract
The concentrated 70% ethanolic extracts of the air-dried powdered leaves and stem bark of Flacourtia cataphracta were subjected separately to solvent fractionation by partitioning using n-hexane, chloroform and ethyl acetate respectively. Each concentrated fraction was subjected to TLC followed by isolation, purification and identification of the available constituents. Fourteen compounds were isolated and identified by different spectral tools (UV, IR, 1H-NMR, 13C-NMR, MS) and comparison with corresponding literature data. -amyrin (1), -amyrin (2), and a mixture of -sitosterol and stigmasterol (3) were isolated from nhexane fraction of both leaves and stem bark. 2-Oxo-18benzolyloxy-13(16), 14-tetrahydrocleroda-3-ene (4), 3 -acetoxyD:A friedo oleanan-27,16 -lactone (5), 4,4'-dihydroxychalcone (6), apigenin (7) and kampferol (8) were isolated from chloroform fraction of the stem bark. -Sitosterol-3-O -D-glucoside (9), 5-Ocaffeoylquinic acid (10) were isolated from the ethyl acetate fraction of the leaves in addition to vanillin (11), benzoic acid (12), protocatechuic acid (13) and flacourtin (14) from the ethyl acetate fraction of the stem bark. The different leaf extracts were subjected to biological study which revealed that n-hexane, ethyl acetate and methanol fractions of Flacourtia cataphracta Roxb. are safe to be used as antidiarrheal, anti-inflammatory and antipyretic drug.
- Published
- 2006
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29. PHENOLICS OF CYPERUS ALOPECUROIDES ROTTB. INFLORESCENCES AND THEIR BIOLOGICAL ACTIVITIES
- Author
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Gamal A. Mohamed, Rainer Ebel, O.R. Omobuwajo, Mahmoud H. Mohamed, Peter Proksch, Hanaa M. Sayed, and Salwa F. Farag
- Subjects
Pharmacology ,chemistry.chemical_compound ,chemistry ,Traditional medicine ,Scopoletin ,Apigenin ,Pharmaceutical Science ,Ether ,Kaempferol ,Quercetin ,Luteolin ,Isoliquiritigenin ,Aureusidin - Abstract
Sixteen phenolic compounds, scopoletin (1), isoliquiritigenin 4-methyl ether (2), luteolin 5,3-dimethyl ether (3), luteolin 7,3-dimethyl ether (4), aureusidin 4-methyl ether (5), apigenin (6),luteolin (7), trans-ferulic acid (8), luteolin 4-O- -D-glucopyranoside(9), luteolin 7-O- -D-glucopyranoside (10), quercetin3-O- -D-glucopyranoside (11), apigenin 7-O-neohesperidoside(12), kaempferol 3-O-rutinoside (13), quercetin 3-O-rutinoside(14), kaempferol 3-O-[2-O-D-xylopyranosyl-6-O--L-rhamnopyranosyl]- -D-glucopyranoside (15) and kaempferol 3-O-[2-OD-glucopyranosyl-6-O--L-rhamnopyranosyl]- -D-glucopyranoside(16) were isolated from the methanolic extract of theinflorescences of Cyperus alopecuroides Rottb. for the first time.Their structures have been established on the basis of physical,chemical and spectroscopic methods in addition to comparisonwith literature data and/or authentic samples. The antioxidant andcytotoxic activities in addition to -amylase inhibitory activity ofthe isolated compounds have been studied.
- Published
- 2006
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30. The biochemical and morphological alterations following administration of melatonin, retinoic acid and Nigella sativa in mammary carcinoma: an animal model
- Author
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Abdel-Raheim M.A. Meki, Mohamad A. Abd El-Aziz, Sary Kh Abd-Elghaffar, Mahmoud R. Hussein, Mahmoud H. Mohamed, and Hosny A. Hassan
- Subjects
medicine.medical_specialty ,Retinoic acid ,DMBA ,Cell Biology ,Biology ,medicine.disease ,medicine.disease_cause ,Prolactin ,Pathology and Forensic Medicine ,Lipid peroxidation ,chemistry.chemical_compound ,Endocrinology ,chemistry ,Apoptosis ,Internal medicine ,medicine ,Carcinoma ,Molecular Biology ,Oxidative stress ,Carcinogen - Abstract
Worldwide, breast cancer is the second leading cause of cancer death among women and the third most common cancer. Although our understanding of the molecular basis of this fatal disease has improved, this malignancy remains elusive. Melatonin (Mel), retinoic acid (RA) and Nigella sativa (NS) are substances with anticancer effects. To date, our understanding of the mechanisms of therapeutic effects of these products in mammary cancer is still marginal. To look at the preventive and therapeutic values of these products, we carried out this investigation. An animal model formed of 80 rats was established. The animals were divided into eight groups of 10 animals each: (a) control group injected with the same vehicle used for treatments in the relevant dosages and routes; (b) carcinogen group injected with the known carcinogenic substance 7,12-di-methylbenz(a)anthracene (DMBA) that induces mammary carcinoma; (c) three prophylactic (Pro) groups (Mel-Pro, RA-Pro and NS-Pro) injected with test substances (Mel, RA and NS, respectively) 14 days before the intake of the carcinogenic substance DMBA and then continued until the end of the experiments; and (d) three treated (Tr) groups (Mel-Tr, RA-Tr and NS-Tr) injected with the vehicles after the intake of DMBA. In both the Pro and Tr groups, the drugs were daily administered for 3 months. The animals were killed, and their serum and tissues were evaluated for (a) markers of tumorigenicity [serum levels of total sialic acid (TSA) and lipid-bound sialic acid (LSA)], (b) markers of endocrine derangement (serum prolactin, estradiol and progesterone levels), (c) apoptotic changes [serum tumour necrosis factor (TNF)-alpha, tissue caspase-3 activity, percentage of DNA fragmentation and ultrastructural features of apoptosis] and (d) markers of oxidative stress (tissue levels of lipid peroxides and nitric oxide). Carcinoma was absent both in the control and in the NS-Pro groups. Mammary carcinoma occurred in DMBA and other Pro and Tr groups. The frequency of mammary carcinoma was high in the carcinogen DMBA group (60%), followed by the Tr (56%) and finally the Pro groups (33%). These tumours included papillary, comedo and cribriform carcinomas. As compared with the control group, the development of carcinoma in the carcinogen DMBA group was associated with increased levels of (a) markers of tumorigenicity (77.0 +/- 3.3 vs. 209.0 +/- 5.6 and P < 0.05 for TSA; 28.7 +/- 1.7 vs. 41.8 +/- 1.2 and P < 0.01 for LSA), (b) markers of endocrine derangement (2.5 +/- 0.1 vs. 3.6 +/- 0.3 and P < 0.05 for prolactin; 39.6 +/- 1.3 vs. 24.8 +/- 2.1 and P < 0.01 for progesterone and 31.0 +/- 0.7 vs. 51.1 +/- 3.4 and P < 0.01 for estradiol) and (c) markers of oxidative stress (2.3 +/- 0.2 vs. 5.2 +/- 0.7 and P < 0.01 for lipid peroxides and 4.4 +/- 0.2 vs. 7.6 +/- 0.8 and P < 0.01 for nitric oxide). Also, it was associated with decreased levels of markers of apoptotic activity (20.8 +/- 1.1 vs. 13.4 +/- 0.7 and P < 0.01 for caspase-3; 29.0 +/- 1.7 vs. 20.9 +/- 1.3 and P < 0.05 for percentage of DNA fragmentation; and 9.4 +/- 0.8 vs. 52.1 +/- 3.3 and P < 0.01 for TNF-alpha). When compared with the carcinogen DMBA group, the development of carcinoma in the Pro and Tr groups was associated with decreased levels of (a) markers of tumorigenicity, (b) markers of endocrine derangement and (c) markers of oxidative stress. Alternatively, carcinogenicity was associated with statistically significant (P < 0.01) increased levels of markers of apoptotic activity. To conclude, the administration of Mel, RA and NS reduced the carcinogenic effects of DMBA, suggesting a protective role. The possible underlying mechanisms of these effects await further investigations.
- Published
- 2005
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31. MACRO- AND MICROMORPHOLOGICAL CHARACTERS OF CYPERUS ROTUNDUS L. GROWING IN EGYPT
- Author
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Hanaa M. Sayed, Mahmoud H. Mohamed, Salwa F. Farag, and Gamal A. Mohamed
- Subjects
Pharmacology ,Inflorescence ,Botany ,Pharmaceutical Science ,Macro ,Biology ,Cyperus rotundus - Abstract
The macro- and micromorphology of the aerial parts (leaves, culm and inflorescence) of Cyperus rotundus L. growing in Egypt are presented aiming for the determination of the diagnostic features by which each part can be identified in the entire and powdered forms.
- Published
- 2001
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32. Quinovic acid glycosides from Zygophyllum aegyptium
- Author
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Mahmoud H. Mohamed
- Subjects
Pharmacology ,chemistry.chemical_classification ,chemistry.chemical_compound ,Ethanol ,Glucoside ,biology ,Chemistry ,Stereochemistry ,Pharmaceutical Science ,Glycoside ,Zygophyllum ,biology.organism_classification ,Quinovic acid - Abstract
Seven known quinovic acid glycosides were isolated for the first time from the n-BuOH fraction of the 70% ethanol ext. of Zygophyllum aegyptium A. Hosny sp. nov. These compds. were identified as: quinovic acid 3β-O-β-D-quinovopyranoside, quinovic acid 3β-O-β-D-glucopyranoside, 3-O-[α-L-arabinosyl-(1→2)-β-D-quinovopyranosyl]quinovic acid , 3-β-O-β-D-quinovopyranosylquinovic acid-28-O-β-D-glucopyranosyl ester, 3-β-O-[β-D-2-O-sulfonyl quinovopyranosyl]-quinovic acid-28-O-β-D-glucopyranosyl ester (zygophyloside F), 3-β-O-β-D-glucopyranosylquinovic acid 28-O-β-D-glucopyranosyl ester , 3β-O-[β-D-2-O-sulfonyl glucopyranosyl]-quinovic acid-28-O-[β-D-glucopyranosyl] ester (zygophyloside G), in addn. to, β-sitosterol glucoside. The structure elucidation of these compds. was detd. by phys., chem. and spectroscopic methods.
- Published
- 1999
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33. Megastigmane glycosides from seeds of Trifoliumalexandrinum
- Author
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Kazuhiro Ohtani, Mahmoud H. Mohamed, Kazuo Yamasaki, Ryoji Kasai, and Khaled M. Mohamed
- Subjects
chemistry.chemical_classification ,Residue (chemistry) ,chemistry ,Stereochemistry ,Glycoside ,Sugar moiety ,Plant Science ,General Medicine ,Horticulture ,Spectral data ,Molecular Biology ,Biochemistry - Abstract
Five megastigmane glycosides have been isolated from the seeds of Trifoliumalexandrinum L., of which two are known compounds, while three are new compounds showingthe presence of apiofuranosyl- (1→2)-glucopyranosyl residue as a sugar moiety. The structures ofthe isolated compounds were established on the basis of NMR and mass spectral data.
- Published
- 1999
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34. Alkaloids from seeds of Lupinus varius and L. hartwegii
- Author
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Hashem A. Hassanean and Mahmoud H. Mohamed
- Subjects
Lupinus ,biology ,Lupinus hartwegii ,Alkaloid ,Botany ,Spectral analysis ,Plant Science ,General Medicine ,Horticulture ,biology.organism_classification ,Molecular Biology ,Biochemistry - Abstract
A new lupin alkaloid, (−)-13 β -hydroxymultiflorine, was isolated from an ethanol extract of the seeds of Lupinus varius , together with 13 known lupin alkaloids. In addition, two new lupin alkaloids, (+)-2 β -hydroxyaphylline and (+)-13 α -hydroxyaphyllidine, were isolated from seeds of L. hartwegii , together with another 11 known lupin alkaloids. The identification of all compounds was established by spectral analysis.
- Published
- 1997
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35. Peculiar side-chain fission of steroidal glycosides
- Author
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Hashim A. Hassanean, Tsuyoshi Ikeda, Alaa M. Nafady, Toshihiro Nohara, Xing-Hua Zhu, Mohamed A. El-Shanawany, Tsutomu Yoshihara, Masafumi Okawa, and Mahmoud H. Mohamed
- Subjects
chemistry.chemical_classification ,Steroidal glycosides ,Fission ,Chemistry ,Stereochemistry ,Organic Chemistry ,Drug Discovery ,Side chain ,Organic chemistry ,Glycoside ,Alkaline hydrolysis (body disposal) ,Biochemistry - Abstract
The characteristic novel steroidal glycosides of the 23,26-oxygenated spirostanol-type and 16,22-dicarbonyl cholestanol-type obtained in our laboratory underwent the peculiar reactions of side-chain fission between C-22 and C-23 of the steroidal skeleton by acid or alkaline hydrolysis. These reactions would be applied to the structural determination of these sorts of glycosides and suggest the biogenetic pathway of the occurrence of C-22 lactone-type glycosides.
- Published
- 2003
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36. ChemInform Abstract: Novel Oleanene Saponins from Taverniera aegyptiaca Boiss
- Author
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Mahmoud H. Mohamed and Hashim A. Hassanean
- Subjects
Traditional medicine ,Chemistry ,Taverniera aegyptiaca ,General Medicine - Published
- 2010
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37. ChemInform Abstract: Minor Lupin Alkaloids from the Seeds of Lupinus varius and Lupinus hartwegii
- Author
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S. A. El-Moghazy, Khaled M. Mohamed, H. A. Hassanean, and Mahmoud H. Mohamed
- Subjects
Lupinus ,biology ,Chemistry ,Lupinus hartwegii ,Botany ,General Medicine ,biology.organism_classification - Published
- 2010
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38. A new oleanene triterpene from Gladiolus segetum Ker-Gawl
- Author
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Hashim A. Hassanean, Mahmoud H. Mohamed, Mohamed A. El-Shanawany, and Alaa M. Nafady
- Subjects
chemistry.chemical_classification ,Magnetic Resonance Spectroscopy ,biology ,Molecular Structure ,Stereochemistry ,Organic Chemistry ,Saponin ,Plant Science ,Saponins ,biology.organism_classification ,Biochemistry ,Hydrolysate ,Analytical Chemistry ,Medicagenic acid ,Iridaceae ,chemistry.chemical_compound ,Triterpene ,chemistry ,Oleanolic Acid ,Gladiolus ,Oleanolic acid - Abstract
A new pentacyclic oleanene triterpene, 2beta, 3beta, 16alpha, 28-tetrahydroxy-olean-12-ene-23-oic acid (1), as well as the known pentacyclic triterpene medicagenic acid (2), have been isolated by different chromatographic techniques from the acid hydrolysate of the saponin fraction of Gladiolus segetum. The identification of these compounds was established by different methods of physical, chemical and spectral evidence.
- Published
- 2009
39. Lupin alkaloids from the seeds of Lupinus termis
- Author
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Kazuki Saito, Hazem A. Kadry, Taha I. Khalifa, Mahmoud H. Mohamed, Isamu Murakoshi, and Hassan A. Ammar
- Subjects
Lupinus ,Stereochemistry ,Alkaloid ,Plant Science ,General Medicine ,Horticulture ,Biology ,biology.organism_classification ,Molecular Biology ,Biochemistry - Abstract
A new lupin alkaloid, (−)-Δ 5 -dehydroalbine, was isolated from the ethanol extract of the seeds of Lupinus termis together with some unusual lupin alkaloids, (−)-albine, (−)-11,12- seco -12,13-didehydromultiflorine and (−)-13α-hydroxymultiflorine. The structure of the new alkaloid ( 1 ) was presumed to be (−)-Δ 5 -dehydroalbine on the basis of its spectroscopic data. The unusual type of lupin alkaloids substituted at C-13 such as (−)-albine and (−)-Δ 5 -dehydroalbine are assumed to be derived possibly from (−)-13α-hydroxymultiflorine via an aza-Cope rearrangement as the key step.
- Published
- 1991
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40. A new steroid glycoside and furochromones from Cyperus rotundus L
- Author
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Salwa F. Farag, Hanaa M. Sayed, Gamal A. Mohamed, Peter Proksch, and Mahmoud H. Mohamed
- Subjects
Insecticides ,Spectrometry, Mass, Electrospray Ionization ,Khellin ,Magnetic Resonance Spectroscopy ,Optical Rotation ,Stereochemistry ,Cell Survival ,Antineoplastic Agents ,Plant Science ,Biology ,Spodoptera ,Biochemistry ,Protocatechuic acid ,Analytical Chemistry ,chemistry.chemical_compound ,Mice ,Cell Line, Tumor ,Caffeic acid ,Animals ,Visnagin ,Glycosides ,Cyperus ,Isorhamnetin ,chemistry.chemical_classification ,Plant Extracts ,fungi ,Organic Chemistry ,Glycoside ,Sitosterols ,chemistry ,Chromones ,Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization ,Spectrophotometry, Ultraviolet ,Tricin ,Artemia ,Cyperus rotundus - Abstract
Further phytochemical investigation of the aerial parts of Cyperus rotundus L. afforded a new steroid glycoside named sitosteryl (6'-hentriacontanoyl)-beta-D-galactopyranoside (4) in addition to three furochromones, khellin (2), visnagin (3) and ammiol (9). Furthermore, benzo-alpha-pyrone (coumarin) (1), salicylic acid (5), caffeic acid (6), protocatechuic acid (7), p-coumaric acid (8), tricin (10) and isorhamnetin (11) were isolated. The structures of these compounds were established by spectroscopic methods. The isolated furochromones were tested for insect antifeedant activity against larvae Spodoptera littoralis when incorporated in artificial diet and offered to larvae in a chronic feeding bioassay. Also, visnagin, khellin and sitosteryl (6'-hentriacontanoyl)-beta-D-galactopyranoside showed strong cytotoxic activity against L5178y mouse lymphoma cells and were also active in the brine shrimp lethality test.
- Published
- 2007
41. Preliminary Investigation on the Leaf Oil ofLycopersicon hirsutumHumb. et Bonpl
- Author
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S. A. El-Moghazy, Mohamed Kamel, Ari Koskinen, and Mahmoud H. Mohamed
- Subjects
biology ,Monoterpene ,General Chemistry ,biology.organism_classification ,Sesquiterpene ,Lycopersicon ,law.invention ,chemistry.chemical_compound ,chemistry ,law ,Botany ,Solanaceae ,Essential oil ,Piperitone - Abstract
The essential oil obtained from the leaves of the typical form of Lycopersicon hirstum Humb. et Bonpl. (Solanaceae) was analyzed by GC/MS. It was found to contain 48 components of which 17 have been identified. The oil was rich in oxygenated compounds with piperitone as the major component (11.66%). Sesquiterpene hydrocarbons were present in a moderate concentration while monoterpene hydrocarbons were detected only in small concentrations.
- Published
- 1995
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42. Cyclodextrin-enclosed substances of Brazilian propolis
- Author
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Hirohisa Kuroda, Hashim A. Hassanean, Mahmoud H. Mohamed, Alaa M. Nafady, Toshihiro Nohara, Masateru Ono, Mohamed A. El-Shanawany, Hiroyuki Sugimoto, Hitoshi Yoshimitsu, Ken Sasaki, and Shima Doi
- Subjects
chemistry.chemical_classification ,Cyclodextrins ,Cyclodextrin ,Stereochemistry ,General Chemistry ,General Medicine ,Aromadendrin ,Propolis ,Animal origin ,Cinnamic acid ,Inclusion compound ,chemistry.chemical_compound ,chemistry ,Drug Discovery ,Artepillin C ,Organic chemistry ,Phenols - Abstract
By using beta-cyclodextrin-inclusion as a unique technique, an efficient separation of pharmacologically active phenolic compounds from Brazilian propolis was achieved to provide one new compound, 3-(3-hydroxy-3-methyl-butyl)-5-prenyl-4-hydroxycinnamic acid, together with two common cinnamic acid derivatives, artepillin C and capillartemisin A, and two known flavanols, aromadendrin and 3,5,7-trihydroxy-4'-methoxyflavanol.
- Published
- 2003
43. (+)-15β-Hydroxy-17-oxolupanine a lupin alkaloid from the seeds ofLupinus albus
- Author
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Zedan Z. Ibraheim, Omar M. Abdallah, Isamu Murakoshi, and Mahmoud H. Mohamed
- Subjects
Lupinus ,Biochemistry ,Alkaloid ,Chemical structure ,Botany ,Plant Science ,General Medicine ,Horticulture ,Biology ,biology.organism_classification ,Molecular Biology - Abstract
A new lupin alkaloid (+)-15β-hydroxy-17-oxolupanine was isolated from the ethanol extract of the seeds of Lupinus albus together with (+)-tetrahy
- Published
- 1994
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44. 19F NMR spectrometric determination of the partition coefficients of some fluorinated psychotropic drugs between phosphatidylcholine bilayer vesicles and water
- Author
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Mohamed Abdelmottaleb, Keisuke Kitamura, Manabu Kume, Shigehiko Takegami, Ahmed Ahmed Omran, Mahmoud H. Mohamed, Megumi Yoshida, and Abdel Aziz Yousef El-Sayed
- Subjects
Liposome ,Psychotropic Drugs ,Magnetic Resonance Spectroscopy ,Chemistry ,Vesicle ,Bilayer ,Clinical Biochemistry ,Lipid Bilayers ,Analytical chemistry ,Pharmaceutical Science ,Water ,Nuclear magnetic resonance spectroscopy ,Fluorine-19 NMR ,Fluorine ,Analytical Chemistry ,Partition coefficient ,Drug Discovery ,Liposomes ,Phosphatidylcholines ,Absorption (chemistry) ,Lipid bilayer ,Spectroscopy - Abstract
A simple 19F NMR spectrometric method was proposed for the determination of the partition coefficients of fluorinated psychotropic drugs, trifluoperazine (TFPZ), flunitrazepam (FNZ) and flurazepam (FZ) between phosphatidylcholine (PC) bilayer of small unilamellar vesicles (SUVs) and water (buffer). Each 19F NMR spectrum of these drugs in the presence of PC SUV showed a single signal accompanying a PC concentration-depending shift change and broadening, which indicated a fast exchange of these drugs between the water phase and the PC bilayer of SUV. From the relationship between the 19F chemical shift change (Deltadelta) of each drug and the PC concentration, the molar partition coefficients (K(p)'s) were calculated and obtained with a good precision of RSD below 6%. The fractions of the partitioned drugs calculated by using the obtained K(p)-values were in a good agreement with the experimental values. The results demonstrate that the 19F NMR method can be usefully applied to the determination of partition coefficients of many drugs having fluorine atom(s) without any separation procedure, especially for drugs which do not have absorption in the ultraviolet or visible region, or those having absorption but show insignificant spectral changes according to their incorporation to PC bilayers (e.g. FNZ).
- Published
- 2002
45. Stilbene and 2-arylbenzofuran glucosides from the rhizomes of Schoenocaulon officinale
- Author
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Kazuo Yamasaki, Ryoji Kasai, Mahmoud H. Mohamed, Kotomi Suga, Tripetch Kanchanapoom, and Mohamed Kamel
- Subjects
chemistry.chemical_classification ,Mulberroside A ,Stereochemistry ,Glycoside ,General Chemistry ,General Medicine ,Resveratrol ,Pharmacognosy ,Oxyresveratrol ,Rhizome ,chemistry.chemical_compound ,chemistry ,Glucoside ,Drug Discovery ,Stilbenes ,Liliaceae ,Organic chemistry ,Phenols ,Benzofurans ,Rhizobium - Abstract
Two stilbene glucosides, oxyresveratrol 2-O-beta-glucopyranoside and resveratrol 3,4'-O,O'-di-beta-D-glucopyranoside, and a 2-arylbenzofuran glucoside, schoenoside, were isolated from the rhizomes of Schoenocaulon officinale, along with five known compounds, oxyresveratrol 3'-O-beta-D-glucopyranoside, oxyresveratrol, resveratrol 3-O-beta-D-glucopyranoside, mulberroside A and moracin M 3'-O-beta-D-glucopyranoside. The structural elucidations were based on analyses of both physical and spectroscopic data.
- Published
- 2002
46. Effect of phosphatidylserine content on the partition coefficients of diazepam and flurazepam between phosphatidylcholine-phosphatidylserine bilayer of small unilamellar vesicles and water studied by second derivative spectrophotometry
- Author
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Keisuke Kitamura, A. Y. El-Sayed, Shigehiko Takegami, Mohamed Abdelmottaleb, Mahmoud H. Mohamed, Tatsuya Kitade, and Ahmed Ahmed Omran
- Subjects
Isosbestic point ,Liposome ,Diazepam ,Bilayer ,Lipid Bilayers ,Phospholipid ,Analytical chemistry ,Water ,General Chemistry ,General Medicine ,Phosphatidylserine ,Phosphatidylserines ,Flurazepam ,chemistry.chemical_compound ,Membrane ,chemistry ,Spectrophotometry ,Phosphatidylcholine ,Drug Discovery ,Second derivative - Abstract
The affinity of the psychotropic benzodiazepine drugs diazepam (DZ) and flurazepam (FZ) to phosphatidylserine (PS) was examined since PS is abundantly contained in brain membranes. The effect of PS content on the partition coefficients (K(p)s) of these drugs between phosphatidylcholine (PC)-PS bilayer membranes of small unilamellar vesicles (SUV) and water was measured using second derivative spectrophotometry. The second derivative spectra of DZ and FZ measured in the solutions containing various amounts of PC-PS SUV clearly showed derivative isosbestic points and a distinct derivative intensity change depending on the amount of the SUV added. The derivative intensity differences (AD) of the drugs before and after addition of the SUV suspension were measured at a specific wavelength. Using the AD values, the Kp values were calculated and obtained with relative standard deviation of below 10%. The Kp values of both drugs increased according to the PS content in the PS-PC bilayer membranes of the SUV proving that both have higher affinity to the PC-PS bilayer membranes than to PC membranes. The effect was much larger for FZ, i.e., the Kp value of FZ at 30 mol% PS content increased to about five times the value for the PC SUV. This can be explained by the fact that at the experimental pH of 7.4, 80% of FZ molecules are in a cationic form (pKa=8.1), so that these molecules are highly accessible to the negatively charged PS molecules. The results support the rapid and high distribution of DZ and FZ in the central nervous system after their administration.
- Published
- 2002
47. A New Lupine Alkaloid, (-)-Δ5S-Dehydromultiflorine, from the Seeds of Lupinus termis
- Author
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Hazem A. Kadry, Isamu Murakoshi, Taha I. Khalifa, Hassan A. Ammar, Mahmoud H. Mohamed, and Kazuki Saito
- Subjects
Pharmacology ,biology ,Alkaloid ,Organic Chemistry ,Pharmaceutical Science ,Pharmacognosy ,biology.organism_classification ,Isolation (microbiology) ,Analytical Chemistry ,Lupinus ,Complementary and alternative medicine ,Drug Discovery ,Botany ,Molecular Medicine ,Medicinal plants - Published
- 1990
- Full Text
- View/download PDF
48. Predictors of cardiovascular risks in obstructive sleep apnea syndrome
- Author
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Mahmoud H Mohamed, Ashraf G Dala, Sanaa S Gazareen, and Ehab A Abdel Atty
- Subjects
medicine.medical_specialty ,business.industry ,Materials Science (miscellaneous) ,Sleep apnea ,Intermittent hypoxia ,medicine.disease ,Systemic inflammation ,respiratory tract diseases ,Obstructive sleep apnea ,Systematic review ,medicine ,Physical therapy ,Breathing ,Endothelial dysfunction ,medicine.symptom ,Intensive care medicine ,Airway ,business - Abstract
Objective The aim of the study was to assess the predictors of cardiovascular risks in obstructive sleep apnea (OSA) syndrome. Data sources They included medical text books, medical journals, and medical websites that have updated research with keywords 'cardiovascular risks' in the title of the paper. Study selection Systematic reviews that addressed OSA syndrome and studies that addressed cardiovascular risks in OSA syndrome were included. Data extraction Special search was performed at midline with keywords 'cardiovascular risks' in the title of the papers; extraction was made, including assessment of the quality and validity of papers that met with the prior criteria that describe cardiovascular risks in OSA syndrome. Data synthesis Each study was reviewed independently; obtained data were rebuilt in new language according to the need of the researcher and arranged in topics through the article. Recent findings There is also strong evidence supporting the association between sleep apnea and hypertension, arrhythmias, and coronary heart disease, as well as overall cardiovascular mortality. OSA is accompanied by activation of multiple cardiovascular disease mechanisms. Conclusion OSA, presumably mainly through intermittent hypoxia, is associated with oxidative stress, systemic inflammation, and vascular endothelium damage and dysfunction. Both systemic inflammation and endothelial dysfunction are aggravated when sleep-disordered breathing is associated with other comorbid conditions, such as morbid obesity. There are new directions regarding upper airway collapse mechanisms, such as pharyngeal denervation. There is also strong evidence supporting the association between sleep apnea and hypertension, arrhythmias, and coronary heart disease, as well as overall cardiovascular mortality.
- Published
- 2014
- Full Text
- View/download PDF
49. Efficacy of Pulsed Electromagnetic Field Therapy on Acute Radiodermatitis in Breast Cancer Patients
- Author
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Mahmoud H Mohamed, PhD, Assistant Professor of Physical Therapy
- Published
- 2024
50. THE LUPIN ALKALOIDS OF SOPHORA SECUNDIFLORA IN EGYPT(ลูปีนแอลคาลอยด์จากตัน Sophora secundiflora ที่ขึ้นในประเทศอียิปต์
- Author
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Sekine, Toshikazu, primary, Arai, Noriko, additional, Saito, Kazuki, additional, Makboul, Mahmoud H. Mohamed M.A., additional, and Murakoshi, Isamu, additional
- Published
- 1992
- Full Text
- View/download PDF
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