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Effective damping of local low frequency oscillations in power systems integrated with bulk PV generation

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Protection and Control of Modern Power Systems 2021年第1期6卷 512-524页

作者： Ahmed Hesham abd el-kareem Mohamed abd elhameed Mahmoud M.elkholy Operation Engineer at New Capital Power Plant New Capital CityEgypt electrical Power and Machines Department Faculty of EngineeringZagazig UniversityZagazigEgypt

High penetration of renewable sources into conventional power systems results in reduction of system inertia and noticeable low-frequency oscillations (LFOs) in the rotor speed of synchronous generators. In this paper, we propose effective damping of LFOs by incorporating a supplementary damping controller with a photovoltaic (PV) generating station, where the parameters of this controller are coordinated optimally with those of a power system stabilizer (PSS). The proposed method is applied to damp local electromechanical modes by studying a system comprising a synchronous generator and a PV station connected to an infinite bus. The PV station is modeled following the instructions of the Western electricity Coordinating Council. The problem is modeled as an optimization problem, where the damping ratio of the electromechanical modes is designed as the objective function. Constraints including upper and lower limits of decision parameters and damping ratio of other modes are considered by imposing penalties on the objective function. Different optimization algorithms are used to pursue the optimal design, such as political, improved gray wolves and equilibrium optimizers. The results validate the effectiveness of the proposed controller with PSS in damping local modes of oscillations.

关键词： Low frequency oscillations Damping controller PV WECC

Physico-analytical Studies on Salicylaldehyde Thiosemicarbazone Complexes

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Journal of Materials Science & Technology 1998年第5期14卷 434-440页

作者： Abo el Fetoh, S.H. abd el-kareem, A.T. Wassel, M.A. Eid, A.E. Faculty of Girls-Ain Shams University Egypt National Research Centre Egypt Faculty of Science El-Menoufia University Egypt Faculty of Science Al-Azhar University Egypt

The complexes of salicylaldehyde thiosemicarbazone with Pd, Cu and Ru were prepared. The prepared complexes were characterized by spectroscopic, element and thermal analyses and D.C. conductivity measurements. The antimicrobial activity of all the prepared compounds against gram-positive, gram-negative and fungi was studied. From these studies, it has been obtained that the ligand is bonded to the metals through O, N and S, but to palladium in [Pd (H//2L//2)] Cl//2 only through N and O. Biological studies confirm that the organic effect on both gram-positive and gram-negative bacteria is very weak and their complexes have no effect on fungi, but Cu-complex has strong influence on both types of bacteria. (Edited author abstract) 22 Refs.

关键词： Metallorganic polymers

Differential control of growth,apoptotic activity and gene expression in human colon cancer cells by extracts derived from medicinal herbs,Rhazya stricta and Zingiber officinale and their combination

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World Journal of Gastroenterology 2014年第41期20卷 15275-15288页

作者： Ayman I elkady Rania abd el Hamid hussein Osama A Abu-Zinadah Department of Biological Sciences Faculty of SciencesKing Abdulaziz University Zoology Department Faculty of ScienceAlexandria University Department of Clinical Nutrition Faculty of Applied Medical SciencesKing Abdulaziz University Gamal abd el Nasser Hospital

AIM: To investigate the effects of extracts from Rhazya stricta (R. stricta) and Zingiber officinale (Z. officinale) on human colorectal cancer cells.

关键词： Apoptosis Colorectal cancer Oncogenes Phytochemicals Tumor suppressor proteins

Detection of virulent strains of Helicobacter pylori and its relation to symptoms and signs in children

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Asian Pacific Journal of Tropical Medicine 2010年第1期3卷 59-62页

作者： Fayed S abd el Dayem S hussein H Sherief M el-Naghi S Pediatric Department Al Azhar University Pediatric Department National Research Centre Microbiology Department Al Azhar University Pediatric Department National Hepatology and Tropical Medicine Research

Objective:To detect the prevalence of Helicobacter polori(***) in a group of pediatric patients complaining of gastrointestinal disorders,and to identify the virulent strains of H. pylori and its relation to peptic ***:The study included 60 patients(41 males and 19 females),aged from 6 months to 14 years,with complaining of different gastrointestinal *** IgG antibodies were *** examination of the oesophagus, stomach and duodenum was done in all patients using a fibreoptic *** addition, gastric antral biopsies were taken for diagnosis of *** infection in the following test: rapid urease test,histopathologic examination and *** cytotoxin assay of virulent strains was *** infection was diagnosed if 3 or more tests for diagnosis were found to be ***:33 out of 60 patients(55%) was positive.12(20%) patients had positive toxin producing strains(virulent strains).Virulent strain had a significantly closer relationship with recurrent abdominal pain,while no difference was found in other symptoms. Age of patients showed a highly significant positive correlation with virulent *** strain. Histopathological finding revealed that oesophagitis was significandy common in patients with negative *** and histopathological findings revealed that virulent strain had a significandy higher gastritis and oesophagitis ***:Infection by virulent strains of *** in children is not uncommon:It is associated with endoscopic and histopathologic *** cases infected with virulent strain showed positive results by using rapid urease test,culture and IgG antibodies.

关键词： Helicobacter pylori IgG antibody Pediatric Gastrointestinal disorder

Histopathological changes in the oesophageal mucosa in Egyptian children with corrosive strictures: A single-centre vast experience

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World Journal of Gastroenterology 2019年第7期25卷 870-879页

作者： Ayman EskANDer Carolyne Ghobrial Nabil A Mohsen Bahaa Mounir Dalia abd el-kareem Sara Tarek Mortada HF el-Shabrawi Department of Paediatrics Kasr Alainy School of Medicine Cairo University Department of Pathology Kasr Alainy School of Medicine Cairo University

BACKGROUND The caustic ingestion continues to be a major problem worldwide especially in developing countries. The long-term complications include stricture and increased life time risk of oesophageal carcinoma. Patients suffered from corrosive induced oesophageal strictures have more than a 1000-fold risk of developing carcinoma of the *** To determine the possibility of oesophageal mucosal dysplasia after prolonged dilatation in post corrosive *** This observational study was conducted at the Paediatric Endoscopy Unit in Cairo University Children's Hospital. It included children of both sexes older than 2 years of age who had an established diagnosis of post-corrosive oesophageal stricture and repeated endoscopic dilatation sessions for more than 6 mo. All patients were biopsied at the stricture site after 6 mo of endoscopic dilatation. A histopathological examination of an oesophageal mucosal biopsy was performed for the detection of chronic oesophagitis, inflammatory cellular infiltration and *** The mean age of the enrolled children was 5.9 ± 2.6 years; 90% of the patients had ingested an alkaline corrosive substance(potash). The total number of endoscopic dilatation sessions were ranging from 16 to 100 with mean number of sessionswas 37.2 ± 14.9. Histopathological examination of the specimens showed that 85%of patients had evidence of chronic oesophagitis(group A) in the form of basal cell hyperplasia, hyperkeratosis and subepithelial fibrosis. Thirteen percent of the patients had evidence of reactive atypia(group B) in the form of severe neutrophilic intraepithelial inflammatory cellular infiltration, and 2 patients(2%)had mild squamous dysplasia(group C); we rebiopsied these two patients 6 mo after the initial pathological assessment, guided by chromoendoscopy by Lugol's *** The histopathology of oesophageal mucosal biopsies in post-corrosive patients demonstrates evidence of chronic oesophagitis, intraepi

关键词： Children Endoscopic dilatation Dysplasia Oesophageal strictures Postcorrosive

Pterostilbene induces cell apoptosis and inhibits lipogenesis in SKOV3 ovarian cancer cells by activation of AMPK-induced inhibition of Akt/mTOR signaling cascade

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BIOCelL 2021年第1期45卷 89-101页

作者： ATTALLA el-KOTT EMAN elBEALY FAHMY elSAID HAITHAM el-MEKKAWY abd-el-KARIM abd-LATEIF abdULALI TAWEel HEBA KHALIFA AHMAD KANDEel kareem MORSY ESSAM IBRAHIM MASHAel MOHAMMED BIN-MEFERIJ Biology Department College of ScienceKing Khalid UniversityAbha61413Saudi Arabia Zoology Department College of ScienceDamanhour UniversityDamanhour22511Egypt Biology Department College of Science for GirlsKing Khalid UniversityAbha61413Saudi Arabia Zoology Department College of ScienceMansoura UniversityMansoura35511Egypt Zoology Department College of ScienceFayoum UniversityFayoum63511Egypt Zoology Department Faculty of ScienceAl-Zawia UniversityAl-ZawiaLibya Biology Department Faculty of ScienceCairo UniversityCairo12611Egypt Research Center for Advanced Materials Science(RCAMS) King Khalid UniversityAbha61413Saudi Arabia Blood Products Quality Control and Research Department National Organization for Research and Control of BiologicalsCairo12611Egypt Biology Department College of SciencePrincess Nourah bint Abdulrahman UniversityRiyadhSaudi Arabia

This study investigates if the anti-tumor effect of Pterostilbene in the SKOV3 ovarian cancer(OC)cell line involves inhibition of cell metabolism and tested in this effect involves modulating AMPK and Akt-induced regulation of ***,SKOV3 cells were cultured in the humidified conditions in DMEM media for 24 h with or without increasing concentration of ***,the cells were incubated with Pterostilbene(IC_(50)=50μM)under similar conditions with or without pre-incubation with Dorsomorphin,an AMPK *** a dose-dependent manner,Pterostilbene inhibited SKOV3 cell survival and increased their lysate levels of lactate dehydrogenase(LDH)and single-stranded DNA(ssDNA).When SKOV3 cells were treated with 50μM Pterostilbene,Pterostilbene significantly suppressed cell migration and invasion,reduced lysate levels of lactic acid and the optical density of Oil Red O staining,and increased lysate glucose *** also increased levels of malondialdehyde(MDA),reactive oxygen species(ROS),and induced intrinsic cell apoptosis by upregulating protein levels of Bax and cleaved caspase-3 and reducing protein levels of ***,Pterostilbene reduced mRNA levels of sterol regulatory element-binding protein 1(SREBP-1),fatty acid synthase(FAS),acetyl CoA carboxylase-1(ACC-1),and AMP-activated protein kinase(AMPK).Furthermore,Pterostilbene increased the protein levels of p-AMPK,p-p53,p-raptor,p-TSC-2,but significantly decreased protein levels of p-Akt,p-TSC-2,p-mTOR,p-S6K1,and *** with Dorsomorphin(CC)abolished all the anti-tumorigenesis effects afforded by Pterostilbene and prevented Pterostilbene-induced phosphorylation of Akt,p53,and *** conclusion,the tumorsuppressive effect of Pterostilbene in SKOV3 cells involves the induction of ROS and inhibition of dysregulation cell metabolism mainly due to AMPK-induced Akt-dependent or independent suppression of mTOR.

关键词： Pterostilbene Ovarian cancer Lipogenesis Apoptosis AMPK

Serologic, endoscopic and pathologic findings in pediatric celiac disease: A single center experience in a low/middle income country

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World Journal of Clinical Pediatrics 2022年第3期11卷 295-306页

作者： Hala H Mansour Nabil A Mohsen Mortada HF el-Shabrawi Somia M Awad Dalia abd el-kareem Department of Pediatrics Faculty of Medicine Kasr Al AinyCairo UniversityCairo 12411Egypt Department of Pathology Cairo UniversityCairo 11562Egypt

BACKGROUND Studies in Africa,Asia,and Latin America are needed to provide a comprehensive picture of the global incidence of celiac disease(CD).AIM To describe the serology,endoscopic and histological findings in typical and atypical presentations of pediatric CD at a tertiary referral hospital in an African low/middle income country(LMIC).METHODS This observational study was conducted on 199 patients with CD from 2010 to *** patients were divided into typical and atypical groups according to the presenting symptoms including 120 and 79 patients ***,upper gastrointestinal endoscopy with duodenal biopsy were performed for patients who had symptoms suggestive of *** severity of the intestinal damage was graded according to the histo-pathologic Marsh-Oberhuber *** Chronic diarrhea was the main intestinal presentation in the typical *** was the most common extraintestinal symptom in both the typical and atypical ***-Oberhuber type 3b and 3c was significantly higher in the seropositive patients with a P value of 0.007.A significant correlation was observed between the histological grade of the biopsied duodenal mucosa and the clinical presentation(P<0.001).Age was significantly higher in the atypical group(P value<0.001).CONCLUSION Although typical CD was observed in 120 patients in this study,the clinical variability of the condition was frequently *** only was a significant predictor for the appearance of atypical ***,CD presentations in LMIC are not different from industrialized countries.

关键词： Typical Atypical celiac disease Celiac serology Marsh-Oberhuber histopathology

Impact of COVID-19 infection during pregnancy on maternal and fetal outcomes

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Reproductive and Developmental Medicine 2023年第2期7卷 108-114页

作者： Mohamed elsibai Anter Nasser Kamal abd el-Aal Mohamed abd Allah Rezk hussein Fahmy Moawad Ahmed Tharwat Abudakika Obstetrics and Gynecology Department Faculty of MedicineElkom CityMenoufia UniversityMenoufiaEgypt Resident of Obstetrics and Gynecology at al-Bagour General Hospital al-Bagour CityMenoufiaEgypt

Objectives:The objective of this study is to assess the impact of coronavirus disease 2019(COVID-19)infection during pregnancy on maternal and fetal outcome in relation to gestational ***:This retrospective study was conducted between May 2020 and July ***-five women infected with severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)and hospitalized at a quarantine hospital were ***-four women received prenatal care at the hospital until delivery,while 31 dropped out from the study due to COVID-19 recovery and discharge before ***:COVID-19 was found in 83%of the pregnant women after 20 weeks of *** most common symptoms were cough and *** complications included severe pneumonia and *** maternal mortality rate was 9.2%.Premature rupture of membranes and severe hypertension during labor affected nearly 9%of the pregnant women who completed prenatal care until delivery at the *** labor occurred at a rate of 38.2%.There were seven(20.8%)stillbirths and two cases of infant ***:Hospitalized pregnant women who have coronavirus infection,lymphopenia,and a high C-reactive protein level were at a higher risk of developing severe illness,which can lead to maternal and neonatal complications.

关键词： COVID-19 Hospitals Infant Quarantine Pregnancy outcome Prenatal care Women

Bitter gourd extract improves glucose homeostasis and lipid profile via enhancing insulin signaling in the liver and skeletal muscles of diabetic rats

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Asian Pacific Journal of Tropical Biomedicine 2021年第8期11卷 344-352页

作者： Saber Mohamed Eweda Mennatallah Ahmed Ali Hala Mohamed abd el-Bary Nahed hussein el-Sokkary Madiha Hassan Helmy Maher abdel-Nabi Kamel Department of Biochemistry Faculty of ScienceAlexandria UniversityAlexandriaEgypt Department of Pharmacology&Therapeutics Faculty of Pharmacy and Drug ManufacturingPharos University in AlexandriaAlexandriaEgypt Department of Biochemistry Medical Research InstituteAlexandria UniversityAlexandriaEgypt Department of Physiology Faculty of MedicineAlexandria UniversityAlexandriaEgypt Medical Laboratories Technology College of Applied Medical SciencesTaibah UniversityMadinahKSA

Objective:To investigate the modulatory effects of bitter gourd extract on the insulin signaling pathway in the liver and skeletal muscle tissues of diabetic ***:The ethanolic extract of bitter gourd was prepared and its contents of total polyphenols and flavonoids were assayed.A neonatal streptozotocin-induced diabetic rat model was established and the diabetic rats were assigned into different groups and were treated with different doses of bitter gourd extract(100,200,400,or 600 mg/kg)or with glibenclamide(0.1 mg/kg)for 30 *** blood glucose,insulin,and lipid profile were evaluated and the insulin signaling pathway in the liver and skeletal muscle of rats was *** correlations between homeostasis model assessment(HOMA)and the components of insulin signaling pathway were also ***:Different doses of bitter gourd extract significantly ameliorated fasting blood glucose level and HOMA index for insulin ***,bitter gourd extract increased serum insulin and improved disrupted serum lipid *** levels of insulin receptor substrate-1(IRS-1),p-insulin receptorβ(p-IR-β),protein kinase C(PKC),GLUT2,and GLUT4 were improved by treatment with bitter gourd *** best results were obtained with 400 mg/kg dose of the extract,the effect of which was equivalent to that of *** in the bitter gourd treated rats was negatively correlated with p-IR-β,IRS-1 and PKC in hepatic and skeletal *** was also negatively correlated with skeletal muscle ***:Bitter gourd extract improves glucose homeostasis and lipid profile in diabetic rats via enhancement of insulin secretion and ***,bitter gourd can be used as a potential pharmacological agent for the treatment of type 2 diabetes mellitus.

关键词： Neonatal Streptozotocin Diabetic Sulfonylurea Bitter gourd Phosphorylated insulin receptor Protein kinase C IRS-1 GLUT2/GLUT4 Insulin signaling