Ahmed Mohamed Hussein

Synthesis and Spectral Characterization of Novel Thiazolopyridine and Pyrimidine Derivatives

Abstract Novel thiazolo [3,2-a]pyridine and thiazolo[3,2-a]pyrimidine derivatives, pyrazolo[3,4-b]pyrano[2,3-d]thiazole, and coumarin derivatives were synthesized from readily obtainable starting materials such as (Z)-2-ethoxycarbonyl methyl-5-(4-chlorobenzylidene)-2-thiazolidin-4(H)one 3 and (Z)-4-(4-hydroxybenzylidene)-2-imino-2-thiazolidin-4(H)one 11. GRAPHICAL ABSTRACT

Development of integrated brakes and engine traction control system

Traction control system (TCS) helps regulating wheel slip when vehicle starts from rest or accelerates excessively. It limits the slip either by applying braking torque or suppressing the engine torque or by using both techniques. The brakes has faster response than the engine; however, overusing brakes decrease its lifetime and increase the fuel consumed. In this paper, a TCS is proposed that utilizes both the brakes and the engine to control the wheel slip. Fuzzy and PID control strategies are used to control the brakes and engine respectively. When slip exceeds a certain threshold, the brakes TCS is activated, after a couple seconds the control is switched smoothly to the engine TCS and then the Brakes TCS is deactivated. The controller design was verified through simulations on the Simulink environment. The results show that the controller is able to maintain slip ratio at the desired value with smooth transition during switching controllers in addition to its capability of coping with sudden change in road conditions.

SPICE Modeling of Free-Space Optical Systems

A three dimensional free-space optical library is developed and implemented using C language inside a SPICE simulator for accurate and realistic co-simulation with electronic and electromechanical elements. A parametric, transient, and Monte-Carlo simulation of a 2times2 optical switch is demonstrated using this library

Ovarian Reserve Following Laparoscopic Ovarian Cystectomy vs Cyst Deroofing for Endometriomas

STUDY OBJECTIVEnBecause laparoscopic ovarian cystectomy of endometriomas is known to adversely impact patient ovarian reserve, the search for other techniques of surgical management is ongoing. The present study was undertaken to evaluate laparoscopic cyst deroofing as a feasible alternative.nnnSTUDY DESIGNnProspective, randomized clinical trial (Canadian Task Force classification I).nnnSETTINGnUniversity maternity hospital.nnnPATIENTSnWomen diagnosed with unilateral or bilateral ovarian endometriomas.nnnINTERVENTIONSnPatients were managed with either laparoscopic ovarian cystectomy or cyst deroofing.nnnMEASUREMENTS AND MAIN RESULTSnA total of 122 women with endometriomas were randomized to either laparoscopic cystectomy (group 1) or laparoscopic cyst deroofing (group 2). The primary endpoint was the effect on ovarian reserve based on changes in anti-Müllerian hormone (AMH) values. At 1 month postsurgery, anti-Müllerian hormone values were significantly decreased (p < .001) from preoperative values, from 4.25 ± 0.87ng/mL to 1.66 ± 1.02ng/mL in group 1 and from 4.2 ± 1.69ng/mL to 2.15 ± 1.48ng/mL in group 2. In addition, antral follicle count and ovarian volume decreased significantly (p < .001) in both groups by 1 month postsurgery. The decreases in these 3 parameters were more significant (p < .001) in group 1 than in group 2.nnnCONCLUSIONnLaparoscopic cyst deroofing of endometriomas appears to be a promising alternative to laparoscopic cystectomy, with less postoperative decrease in ovarian reserve; however, the higher rate of endometrioma recurrence warrants future clinical research to determine the optimal surgical management of endometriomas.

Serum ferritin as a non-invasive marker in the prediction of hepatic fibrosis among Egyptian patients with non-alcoholic fatty liver disease: Ferritin in non-alcoholic fatty liver disease

Many studies have found a relationship between hepatic iron, serum ferritin, and non‐alcoholic fatty liver disease (NAFLD) or its progress. The aim of this study is to assess the value of serum ferritin as a non‐invasive marker in the prediction of hepatic fibrosis in NAFLD.

The relation between nonalcoholic fatty liver disease and carotid intima-media thickness in Egyptian patients

Background and aim Nonalcoholic fatty liver disease (NAFLD) is strongly associated with obesity, type II diabetes, and dyslipidemia. Thus, NAFLD shares many features of the metabolic syndrome, a highly atherogenic condition, and its presence could signify a substantial cardiovascular risk. The intima-media thickness (IMT) of the carotid artery is a reliable indicator of subclinical atherosclerosis, and it has been shown that increased IMT is associated with increased prevalence and incidence of myocardial infarction and stroke. In recent years, carotid artery IMT measurements by high-resolution carotid B-mode ultrasonography have been widely used to study the severity and progression of atherosclerosis. This study was designed to assess the correlation between NAFLD as a cardiovascular risk factor and carotid atherosclerosis. Patients and methods A hospital-based case–control analytical study was conducted on 60 participants who were divided into three groups as follows. Group I included 20 diabetic patients with NAFLD. Group II included 20 nondiabetic patients with NAFLD. Group III included 20 healthy participants who served as a control group. The right and left carotid intima-media thickness (CIMTs) and their maximum reading (CIMTmax) was measured by a skilled sonographer blind to the groups. Pelviabdominal ultrasound was performed for all participants, and the sonographic grading of the NAFLD was determined in groups I and II. Histological grading of hepatic steatosis was done by liver biopsy in groups I and II. Results In comparison with the control group, the median CIMTmax was significantly higher in group I and group II (P<0.001), but there was no statistically significant difference between groups I and II (P<0.792). There was a statistically significant positive correlation between CIMT and severity of NAFLD (P<0.001). Strong association is found between the increase of liver enzymes level and increase of carotid IMT in patients of NAFLD, which was highly significant (P<0.001). Conclusion There is a significant association between the presence of NAFLD and atherosclerosis; this association was independent of diabetes mellitus presence. The grade of NAFLD and elevated liver enzymes have a significant effect on severity of atherosclerosis.

Relation between hepatitis B viral load and liver fibrosis assessed using transient elastography in patients with chronic hepatitis B virus infection

Background Several hepatitis B (HB) viral factors such as viral load and genotype were shown to anticipate clinical outcomes. Noninvasive tests assessing liver fibrosis are widely preferred. Aim The aim of this study was to find the relation between HB viral load and liver fibrosis stage assessed using transient elastography in chronic HB patients. Patients and methods This study included 60 chronic HB patients who were divided into two groups. Thirty patients with fibrosis stages F1–F2 constituted group 1, and 30 patients with fibrosis stages F3–F4 constituted group 2. The stage of liver fibrosis was assessed using FibroScan. HB viral load was measured with PCR. Results The median (interquartile range) of HB virus PCR in groups 1 and 2 was 33.5 (16.0–515.5) and 82.5 (16.0–535.0), respectively, with a nonsignificant difference between the two groups (P=0.834). It was 220.0 (16.0–1014.0) and 77.0 (16.0–335.0) in patients with and those without cirrhosis, respectively, with a nonsignificant difference (P=0.552). Receiver operating characteristic analysis showed area under curve of 0.516 for differentiating between the two groups. Conclusion HB viral load was nonsignificantly higher in patients with higher grades of liver fibrosis and cirrhosis with weak diagnostic performance in differentiation between different fibrosis stages.

Safety factor maximization for trusses subjected to fatigue stresses

This article presents a mathematical model for sizing optimization of undamped trusses subjected to dynamic loading leading to fatigue. The combined effect of static and dynamic loading, at steady state, is considered. An optimization model, whose objective is the maximization of the safety factor of these trusses, is developed. A new quantity (equivalent fatigue strain energy) combining the effects of static and dynamic stresses is presented. This quantity is used as a global measure of the proximity of fatigue failure. Therefore, the equivalent fatigue strain energy is minimized, and this seems to give a good value for the maximal equivalent static stress. This assumption is verified through two simple examples. The method of moving asymptotes is used in the optimization of trusses. The applicability of the proposed approach is demonstrated through two numerical examples; a 10-bar truss with different loading cases and a helicopter tail subjected to dynamic loading.