Modeling And Development Of A MEMS Device For Pyroelectric Energy Scavenging

As the world faces an energy crisis with depleting fossil fuel reserves, alternate energy sources are being researched ever more seriously. In addition to renewable energy sources, energy recycling and energy scavenging technologies are also gaining importance. Technologies are being developed to scavenge energy from ambient sources such as vibration, radio frequency and low grade waste heat, etc. Waste heat is the most common form of wasted energy and is the greatest potential source of energy scavenging. Pyroelectricity is the property of some materials to change the surface charge distribution with the change in temperature. These materials produce current as temperature varies in them and can be utilized to convert thermal energy to electrical energy. In this work a novel approach to vary temperature in pyroelectric material to convert energy has been investigated. Microelectromechanical Systems or MEMS is the new technology trend that takes advantage of unique physical properties at micro scale to create mechanical systems with electrical interface using available microelectronic fabrication techniques. MEMS can accomplish functionalities that are otherwise impossible or inefficient with macroscale technologies. The energy harvesting device modeled and developed for this work takes full benefit of MEMS technology to cycle temperature in an embedded pyroelectric material to convert thermal energy from low grade waste heat to electrical energy. Use of MEMS enables improved performance and efficiency and overcomes problems plaguing previous attempts at pyroelectric energy conversion. A Numerical model provides accurate prediction of MEMS performance and sets design criteria, while physics based analytical model simplifies design steps. A SPICE model of the MEMS device incorporates electrical conversion and enables electrical interfacing for current extraction and energy storage. Experimental results provide practical implementation steps towards of the modeled device. Under ideal condition the proposed device promises to generate energy density of 400 W/L

Implications of white spot syndrome virus disease on DNA integrity, histology and biochemistry of Procambarus clarkii in Egypt

White spot syndrome virus (WSSV) is a widespread and highly pathogenic virus; that infects shrimp, crayfish and other crustaceans. The objectives of the present study were to investigate WSSV implications on some crayfish tissues, within light and sever stages of infections. Several parameters have been investigated including DNA integrity, oxidative stress, and histological changes in gills, muscles and hepatopancreas cells, using several techniques such as comet assay, DNA fragmentation assay, oxidative stress biomarkers estimation and histopathological examination. Specimens were divided into three groups according to the nested PCR results. Group I included healthy specimens whose tissues were all negative two-step PCR; Group II involved lightly infected specimens with positive two-step PCR. Group III included heavily infected specimens whose tissues were tested mostly positive one-step PCR. WSSV generates an increase in the different parameters of DNA damage (P<0.05) with abnormal histological features and notable reduction (P<0.05) of the endogenous scavengers in the tested tissues of the infected crayfish in comparison with the normal healthy ones. Furthermore, gills were found to be the most affected organ followed by muscle and finally hepatopancreas. These outcomes additionally demonstrated that comet test could profitably be utilized in genotoxicity evaluation protocols in aquatic invertebrates

Evaluation of the complications of the in situ versus uterine exteriorization repair of caesarean section uterine incision

Background: caesarean section is the most performed major operation around the world. In this study we aim to compare in situ repair of caesarean section uterine incision to repair with uterine exteriorization.Methods: The study was conducted on 200 patients at El-Shatby maternity university hospital during the period from June 2019 to June 2020 and after ethical committee approval and obtaining an informed consent. All cases were 37 weeks gestation or more with singleton fetus prepared to have caesarean section. They were randomly allocated into 2 groups each of 100 participants: group A: with exteriorization repair of the uterus, group B: with in situ repair. After history taking, examination and laboratory investigations, elective caesarean section was done under spinal anesthesia. After delivery of the fetus and placenta, the uterus was repaired either in situ or after exteriorization followed by closure of the abdomen in layers. We assessed: primary outcome: blood loss. secondary outcome: nausea or vomiting, hypotension, operative time and duration of uterine repair, tachycardia, uterine contractility and hematoma formation. Post-operative pain, febrile illness, time of ambulation, time of return of bowel function were also assessed. Data were collected and submitted to statistical analysis. Results: In situ repair had a statistically significant decrease in intra operative nausea, vomiting and tachycardia. Exteriorization resulted in significantly shorter duration of uterine repair; unlikely duration of the whole surgery was not statistically significant. Return of intestinal sounds was statistically significant in favour of in situ repair.Conclusions: There is no definite or absolute privilege of in-situ repair versus exteriorization.

Regulation of alternative polyadenylation in the yeast Saccharomyces cerevisiae by histone H3K4 and H3K36 methyltransferases.

Adjusting DNA structure via epigenetic modifications, and altering polyadenylation (pA) sites at which precursor mRNA is cleaved and polyadenylated, allows cells to quickly respond to environmental stress. Since polyadenylation occurs cotranscriptionally, and specific patterns of nucleosome positioning and chromatin modifications correlate with pA site usage, epigenetic factors potentially affect alternative polyadenylation (APA). We report that the histone H3K4 methyltransferase Set1, and the histone H3K36 methyltransferase Set2, control choice of pA site in Saccharomyces cerevisiae, a powerful model for studying evolutionarily conserved eukaryotic processes. Deletion of SET1 or SET2 causes an increase in serine-2 phosphorylation within the C-terminal domain of RNA polymerase II (RNAP II) and in the recruitment of the cleavage/polyadenylation complex, both of which could cause the observed switch in pA site usage. Chemical inhibition of TOR signaling, which causes nutritional stress, results in Set1- and Set2- dependent APA. In addition, Set1 and Set2 decrease efficiency of using single pA sites, and control nucleosome occupancy around pA sites. Overall, our study suggests that the methyltransferases Set1 and Set2 regulate APA induced by nutritional stress, affect the RNAP II C-terminal domain phosphorylation at Ser2, and control recruitment of the 3 end processing machinery to the vicinity of pA sites.post-print1.432 K

Efeect of Kegel's Exercises on First Degree Pelvic Organ Prolapse Among Women

Background: Kegel's exercises are recommended to increase the strength and elasticity of the pelvic floor muscles and decrease the incidence of prolapse and stress urinary incontince. Aim: was to assess the effect of kegel's exercises on first degree pelvic organ prolapse among women. Design: quasi-experimental, non equivalent pre-post test research design was adopted. Setting: this research was carried out at gynecological clinic at El Galaa Obstetrics and Gynecology Teaching Hospital. Sample: Convenience sample, of 110 women were recruited for this study as one group to be measured before and after according to certain criteria. Tools: three tools were used for data collection: structured interview tool; assessment &amp; follow up tool for clinical picture of prolapse and Prinometry to measure the strength of pelvic floor muscles. Result: revealed that, a statistically significantly differences were founded between before and after following of kegel's exercises in relation to sexual clinical picture P value was ≥ 0.05, urinary clinical picture was (χ2 = 145.4 and p value ≤ 0.001 and types of urinary problems. χ2 = 167.4 and p value≤ 0.001 ) . And bowel clinical picture was (χ2 =128.8 &amp; P.value ≤ 0.001). Regarding to perinometry reading, the results revealed that, highly statistically significant differences was found between the three reading of prinometry (F=68.047, p≤0.001). In Conclusion: practicing kegel's exercises lead to decrease in the clinical picture of prolapse and improve strength of pelvic floor muscles. Recommendation: based on the study findings, its recommended kegel's exercises should be followed during each development phases of women's life span, so it should form an essential part of sex education and the nurse should work as educator and counselor to teach women benefits and technique of kegel's exercises. Keywords:  kegel's exercises, prolapse, prinometry

Association between Macronutrients Intake, Visceral Obesity and Blood Pressure in a Sample of Obese Egyptian Women

AIM: Study the association between the total caloric intake, protein, lipid, and some classes of fatty acids of the diet, and their effects on blood pressure in a sample of Egyptian obese women with and without visceral obesity.METHODS: Five hundred forty-nine obese women were included in the study with mean age of 38.1 ± 11.56 years and mean Body mass index [BMI] of 36.17 ± 7.23. They enrolled in a program for losing weight. Visceral fat was determined using ultrasound. Blood pressure was measured 3 times and the mean was recorded. Twenty four hours dietary recall was reported.RESULTS: Thirty point four percentages of samples has visceral obesity ≥ 7cm; they were the older, showed higher values of BMI, visceral obesity and blood pressure. Significant difference was found between groups regarding mean value of BMI, visceral obesity, both systolic blood pressure SBP and diastolic blood pressure DBP and most of the daily macronutrients intake. In groups (2&amp;3) positive significant correlation was recorded between (SBP) &amp; (DBP) and total daily intake of total calories, carbohydrate, total fat, saturated fatty acids and cholesterol, and negative significant correlation with total daily intake of total protein, animal and vegetable protein, linolenic and linoleic fatty acids, while oleic fatty acid showed negative correlation with SBP&amp;DBP in all groups.CONCLUSION: This study emphasizes the hypothesis that the macronutrients composition of diet influences blood pressure in different ways, in obese patients with visceral obesity