Author
Mahmoud Ahmed
Other affiliations: University of Toronto, University of Baghdad, Jordan University of Science and Technology ...read more
Bio: Mahmoud Ahmed is an academic researcher from Egypt-Japan University of Science and Technology. The author has contributed to research in topics: Heat sink & Solar cell. The author has an hindex of 40, co-authored 292 publications receiving 5467 citations. Previous affiliations of Mahmoud Ahmed include University of Toronto & University of Baghdad.
Topics: Heat sink, Solar cell, Receptor, Placenta, Photovoltaic system
Papers published on a yearly basis
Papers
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TL;DR: The research presented in this paper combines the Hough transform and “Scan-vs-BIM” systems in a unified approach for more robust automated comparison of as-built and as-planned cylindrical MEP works, thereby providing the basis for automated earned value tracking, automated percent-built-as-planned measures, and assistance for the delivery of as -built BIM models from as-designed ones.
358 citations
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TL;DR: In this article, a comprehensive overview of the state-of-the-art technology for the most important factors, affecting methanol crossover in direct methanoline fuel cells is presented.
Abstract: SUMMARY
Direct methanol fuel cells have the potential to power future microelectronic and portable electronic devices because of their high energy density. One of the major obstacles that currently prevent the widespread applications of direct methanol fuel cells is the methanol crossover through the polymer-electrolyte membrane. Methanol crossover is closely related to several factors including membrane structure and morphology, membrane thickness, and fuel cell operating conditions such as temperature, pressure, and methanol feed concentration. This work presents a comprehensive overview of the state-of-the-art technology for the most important factors, affecting methanol crossover in direct methanol fuel cells. In addition, the current and future directions of the research and development activities, aiming to reduce the methanol crossover are reviewed and discussed in order to improve the performance of direct methanol fuel cells. Copyright © 2011 John Wiley & Sons, Ltd.
217 citations
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TL;DR: Pravastatin has been shown in preclinical studies to reverse various pathophysiological pathways associated with preeclampsia, providing biological plausibility for its use for preeclampia prevention as discussed by the authors.
200 citations
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TL;DR: In this paper, a new cooling technique for low concentrated photovoltaic-thermal (LCPV/T) systems is developed using a microchannel heat sink with nanofluids.
165 citations
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TL;DR: The observed low transplacental transfer of BUP to the fetal circuit may explain the moderate/absence of neonatal withdrawal in the limited number of reports on mothers treated with the drug during pregnancy.
Abstract: Information on the direct and indirect effects of buprenorphine (BUP) on the fetus is essential for determining its potential for treatment of the pregnant opiate addict. The goal of this investigation is to determine the transplacental transfer of BUP to the fetal circulation, its metabolism, and effects on the tissue. The technique of dual perfusion of placental lobule is used. The range of BUP concentrations investigated included its peak plasma levels (10 ng/ml) in patients under treatment. A biphasic decline in concentration of the drug in the maternal circulation was observed, initially rapid then slow. During the initial (60 min), the tissue sequestered most of BUP resulting in a low (<10%) transplacental transfer of the drug to the fetal circulation. The concentration ratios of the drug in tissue/maternal and tissue/fetal were 13 ± 6.5 and 27.4 ± 0.4. The drug sequestered did not have any adverse effects on placental tissue viability and functional parameters. Less than 5% of the perfused BUP was metabolized to norbuprenorphine during the 4 h of perfusion and the metabolite was distributed between the tissue, maternal, and fetal circulations. Taken together, these data suggest that the therapeutic levels of BUP in the maternal circulation may have no indirect effects (via the placenta) on the fetus. The observed low transplacental transfer of BUP to the fetal circuit may explain the moderate/absence of neonatal withdrawal in the limited number of reports on mothers treated with the drug during pregnancy.
* BUP
: buprenorphine
CYP
: cytochrome P450
hCG
: human chorionic gonadotropin
AP
: antipyrine
AUC
: area under the concentration-time curve
norBUP
: norbuprenorphine
HPLC
: high-performance liquid chromatography
142 citations
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9,185 citations
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TL;DR: The next generation of scientists and decision-makers will be shaped by the experiences of those who have gone before them and will help shape the future of medicine and science.
3,797 citations
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TL;DR: Recent progress on drug metabolism activity profiles, interindividual variability and regulation of expression, and the functional and clinical impact of genetic variation in drug metabolizing P450s are reviewed.
2,832 citations
01 Jan 1999
TL;DR: Caspases, a family of cysteine-dependent aspartate-directed proteases, are prominent among the death proteases as discussed by the authors, and they play critical roles in initiation and execution of this process.
Abstract: ■ Abstract Apoptosis is a genetically programmed, morphologically distinct form of cell death that can be triggered by a variety of physiological and pathological stimuli. Studies performed over the past 10 years have demonstrated that proteases play critical roles in initiation and execution of this process. The caspases, a family of cysteine-dependent aspartate-directed proteases, are prominent among the death proteases. Caspases are synthesized as relatively inactive zymogens that become activated by scaffold-mediated transactivation or by cleavage via upstream proteases in an intracellular cascade. Regulation of caspase activation and activity occurs at several different levels: ( a) Zymogen gene transcription is regulated; ( b) antiapoptotic members of the Bcl-2 family and other cellular polypeptides block proximity-induced activation of certain procaspases; and ( c) certain cellular inhibitor of apoptosis proteins (cIAPs) can bind to and inhibit active caspases. Once activated, caspases cleave a variety of intracellular polypeptides, including major structural elements of the cytoplasm and nucleus, components of the DNA repair machinery, and a number of protein kinases. Collectively, these scissions disrupt survival pathways and disassemble important architectural components of the cell, contributing to the stereotypic morphological and biochemical changes that characterize apoptotic cell death.
2,685 citations