Novel Synthesis of Imidazo[1,2-b]Pyrazoles and Their Fused Derivatives

Sherif, Sherif-M.,Hussein, Abdel-HaLeem-M.,El-kholy, Yehya-M. The Pharmaceutical Society of Korea 1994 Archives of Pharmacal Research Vol.17 No.5

4-Arylazo-1H-pyrazol-3, 5-idimines 1a-c reacted with bromomalononitrile (2) to yield the corresponding imidazo[1, 2-b]pyrazoles 3a-c. The latter reacted with some active methylene compounds and with .alpha.-cinnamonitriles to afford the corresponding pyrazoloimidazopyridines 6, 8, 9 and 15, respectively. Compounds 3 reacted with each of formic acid, formamide, trichlo-roacetonitrile and with guanidine to yield the corresponding pyrazoloimidazopyrimidines 16-19 respectively.

UNUSUAL CASE OF COR TRIATRIATUM SINISTER

Sherif Moustafa,Nauman Ejaz,Tarek Momenah,Abdulaziz AlKhaldi,Hamed Zuhairy,Abdulrahman AlMoukirish,Farouk Mookadam 한국심초음파학회 2013 Journal of Cardiovascular Imaging (J Cardiovasc Im Vol.21 No.2

Facile Printing of Cotton Fabrics with Phenyldiazenyle Azo dyes

Sherif H. Abdelsalam,Tarek M. Abou Elmaaty 한국색채학회 2011 한국색채학회 학술대회 Vol.2011 No.10

Samples of cotton fabric were printed using two azo dyes of the phenyl diazenyle class. One phase printing technique has been used in this process instead of the troublesome two phase technique that is usually used for azodye printing. Both azo dyes were compared to evaluate the effect of the ester and cyano groups in the presence of urea, alkali and temperature. The objective measurements used for the comparison include fastness to washing, perspiration, rubbing and light respectively.

Impact of a shock wave on a structure strengthened by rigid polyurethane foam

Sherif A. Mazek,Ashraf A. Mostafa 국제구조공학회 2013 Structural Engineering and Mechanics, An Int'l Jou Vol.48 No.4

The use of the rigid polyurethane foam (RPF) to strengthen sandwich structures against blast terror has great interests from engineering experts in structural retrofitting. The aim of this study is to use the RPF to strengthen sandwich steel structure under blast load. The sandwich steel structure is assembled to study the RPF as structural retrofitting. The filed blast test is conducted. The finite element analysis (FEA) is also used to model the sandwich steel structure under shock wave. The sandwich steel structure performance is studied based on detonating different TNT explosive charges. There is a good agreement between the results obtained by both the field blast test and the numerical model. The RPF improves the sandwich steel structure performance under the blast wave propagation

Design, Synthesis, and Antibacterial Activity of Spiropyrimidinone Derivatives Incorporated Azo Sulfonamide Chromophore for Polyester Printing Application

Sherif S. Ragab,Ayman M. K. Sweed,Zeinab K. Hamza,Elkhabiry Shaban,Ahmed A. El-Sayed 한국섬유공학회 2022 Fibers and polymers Vol.23 No.8

We designed and developed a novel series of bioactive disperse dyes by conjugation of spirocyclic 2-thiopyrimidine scaffold with aryl or sulfa drug moieties in the same construct through azo linker to take advantage of thebioactive character of both motifs. The target molecules were simply approached on a gram scale via the diazocoupling ofspirocyclic 2-thiouracil 1 with aryl diazonium chloride derivatives to afford the heterocyclic azo-disperse dyes 4a-e inexcellent yield. These azo dyes were effectively utilized to make pastes for silkscreen printing of polyester fabrics. The colorcharacteristics of the dyes and their fastness properties including washing, rubbing, perspiration, sublimation, and lightfastness were also investigated. The antimicrobial activity of the produced dyes 4a-e was evaluated against some Grampositiveand Gram-negative bacteria, and the results revealed that 4d was more active than the standard drug cefoperazoneagainst the Gram-positive bacteria S. aureus. The antibacterial efficacy of the treated fabrics has also been investigatedrevealing that the dyed fabric 4b was found to have a potent inhibition on B. cereus (93 %), and against E. coli with areduction of (90 %).

Mechanisms of Preconditioning Exercise-Induced Neurovascular Protection in Stroke

Sherif Hafez,Zeina Eid,Sara Alabasi,Yasenya Darwiche,Sara Channaoui,David C. Hess 대한뇌졸중학회 2021 Journal of stroke Vol.23 No.3

Ischemic stroke is a leading cause of death and disability. Tissue plasminogen activator is the only U.S. Food and Drug Administration approved thrombolytic therapy for ischemic stroke patients till date. However, its use is limited due to increased risk of bleeding and narrow therapeutic window. Most of the preclinically tested pharmacological agents failed to be translated to the clinic. This drives the need for alternative therapeutic approaches that not only provide enhanced neuroprotection, but also reduce the risk of stroke. Physical exercise is a sort of preconditioning that provides the body with brief ischemic episodes that can protect the body from subsequent severe ischemic attacks like stroke. Physical exercise is known to improve cardiovascular health. However, its role in providing neuroprotection in stroke is not clear. Clinical observational studies showed a correlation between regular physical exercise and reduced risk and severity of ischemic stroke and better outcomes after stroke. However, the underlying mechanisms through which prestroke exercise can reduce the stroke injury and improve the outcomes are not completely understood. The purpose of this review is to: demonstrate the impact of exercise on stroke outcomes and show the potential role of exercise in stroke prevention and recovery; uncover the underlying mechanisms through which exercise reduces the neurovascular injury and improves stroke outcomes aiming to develop novel therapeutic approaches.

Improving Impact Resistance of Polymer Concrete Using CNTs

Sherif M. Daghash,Eslam M. Soliman,Usama F. Kandil,Mahmoud M. Reda Taha 한국콘크리트학회 2016 International Journal of Concrete Structures and M Vol.10 No.4

Polymer concrete (PC) has been favoured over Portland cement concrete when low permeability, high adhesion, and/or high durability against aggressive environments are required. In this research, a new class of PC incorporating Multi-Walled Carbon Nanotubes (MWCNTs) is introduced. Four PC mixes with different MWCNTs contents were examined. MWCNTs were carefully dispersed in epoxy resin and then mixed with the hardener and aggregate to produce PC. The impact strength of the new PC was investigated by performing low-velocity impact tests. Other mechanical properties of the new PC including compressive, flexural, and shear strengths were also characterized. Moreover, microstructural characterization using scanning electron microscope and Fourier transform infrared spectroscopy of PC incorporating MWCNTs was performed. Impact test results showed that energy absorption of PC with 1.0 wt% MWCNTs by weight of epoxy resin was significantly improved by 36 % compared with conventional PC. Microstructural analysis demonstrated evidence that MWCNTs significantly altered the chemical structure of epoxy matrix. The changes in the microstructure lead to improvements in the impact resistance of PC, which would benefit the design of various PC structural elements.

INCOME DISPARITIES, ECONOMIC GROWTH, AND DEVELOPMENT AS A THRESHOLD

Sherif Khalifa,Sherine El Hag 중앙대학교 경제연구소 2010 Journal of Economic Development Vol.35 No.2

Galor and Moav (2004) argue that in the early stages of development, physical capital accumulation is the primary source of economic growth. Thus, equality enhances growth by channeling resources towards individuals whose arginal propensity to save is higher. In later stages of development, physical capital is replaced by human capital as the engine of growth. Accordingly, equality alleviates the adverse effects of credit constraints on human capital accumulation and prompts the growth process. This paper attempts to test empirically the finding that the impact of income inequality on economic growth depends on the development stage. A threshold estimation technique, developed by Hansen (1999), is utilized for a panel of 70 countries for the period between 1970 and 1999. The estimation suggests that there is a statistically significant threshold income per capita, below which the coefficient on the relationship between inequality and growth is significantly negative and above which the estimate is positive, but not statistically significant.

Strength and Durability Evaluation of Recycled Aggregate Concrete

Sherif Yehia,Kareem Helal,Anaam Abusharkh,Amani Zaher,Hiba Istaitiyeh 한국콘크리트학회 2015 International Journal of Concrete Structures and M Vol.9 No.2

This paper discusses the suitability of producing concrete with 100 % recycled aggregate to meet durability and strength requirements for different applications. Aggregate strength, gradation, absorption, specific gravity, shape and texture are some of the physical and mechanical characteristics that contribute to the strength and durability of concrete. In general, the quality of recycled aggregate depends on the loading and exposure conditions of the demolished structures. Therefore, the experimental program was focused on the evaluation of physical and mechanical properties of the recycled aggregate over a period of 6 months. In addition, concrete properties produced with fine and coarse recycled aggregate were evaluated. Several concrete mixes were prepared with 100 % recycled aggregates and the results were compared to that of a control mix. SEM was conducted to examine the microstructure of selected mixes. The results showed that concrete with acceptable strength and durability could be produced if high packing density is achieved.

OFFSHORING AND WAGE INEQUALITY IN DEVELOPING COUNTRIES

SHERIF KHALIFA,EVELINA MENGOVA 중앙대학교 경제연구소 2010 Journal of Economic Development Vol.35 No.3

The Heckscher-Ohlin model predicts that trade openness causes the skill premium to increase in skill-abundant developed countries, and to decrease in skill-scarce developing countries. Empirical evidence, however, shows that the skill premium declined in some developing countries, while others experienced an increase in wage inequality. This paper develops a North-South model, where firms produce a low-skilled and a high-skilled intensive good. The production of a unit of either good involves a continuum of L-tasks and H-tasks. The L-tasks can be performed by low-skilled workers, and the H-tasks can be performed by high-skilled workers. The Northern firms can produce the task in their headquarters, or offshore the task to the South. The results of the model suggest there is a threshold skill abundance level in the South, above which countries experience an increase in the skill premium after an improvement in the offshoring technology, and below which countries experience a decrease in the skill premium. The same pattern occurs with an improvement in the offshoring technology of tasks in the high-skilled and the low-skilled intensive industries. If wages in local production catch up with wages in the offshoring sector, offshoring does not impact wage inequality at a certain level of skill abundance. A threshold estimation, on 29 developing countries over the period 1982-2000, shows that there is a statistically significant skill abundance threshold, below which the coefficient on the relationship between offshoring and wage inequality is negative, and above which there is no impact of offshoring on wage inequality. Similar results are reached if offshoring is replaced by variables that proxy for the offshoring technology.