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Oscillation theorems for Second-Order Nonlinear Neutral Delay Dynamic Equations on time Scales

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Acta Mathematica Sinica,English Series 2008年第9期24卷 5-1432,1410页

作者： samir h.SAKER Donal O’REGAN Ravi P.AGARWAL Department of Mathematics College of Science King Saud University Riyadh 11451 Saudi Arabia Department of Mathematics National University of Ireland Galway Ireland Department of Mathematical Sciences Florida Institute of Technology Melbourne Florida 32901 USA

By employing the generalized Riccati transformation technique,we will establish some new oscillation criteria and study the asymptotic behavior of the nonoscillatory solutions of the second-order nonlinear neutral delay dynamic equation [r(t)[y(t)+p(t)y(■(t))]~Δ]~Δ+q(t)f(y((δ(t)))=0 on a time scale■.the results improve some oscillation results for neutral delay dynamic equations and in the special case when■our results cover and improve the oscillation results for second- order neutral delay differential equations established by Li and Liu[***.,48(1996), 871 886].When■,our results cover and improve the oscillation results for second order neutral delay difference equations established by Li and Yeh[***.,36(1998),123-132].When ■ ■our results are essentially *** examples illustrating our main results are given.

关键词： oscillation neutral delay dynamic equation generalized Riccati technique time scales

Finite Elementθ-Schemes for the Acoustic Wave Equation

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Advances in Applied Mathematics and Mechanics 2011年第2期3卷 181-203页

作者： samir Karaa Department of Mathematics and Statistics Sultan Qaboos UniversityP.O.Box 36Al-Khod 123MuscatSultanate of Oman

In this paper,we investigate the stability and convergence of a family of implicit finite difference schemes in time and Galerkin finite element methods in space for the numerical solution of the acoustic wave *** schemes cover the classical explicit second-order leapfrog scheme and the fourth-order accurate scheme in time obtained by the modified equation *** derive general stability conditions for the family of implicit schemes covering some well-known CFL *** error estimates are *** sufficiently smooth solutions,we demonstrate that the maximal error in the L^(2)-norm error over a finite time interval converges optimally as O(h^(p+1)+∆t^(s)),where p denotes the polynomial degree,s=2 or 4,h the mesh size,and∆t the time step.

关键词： Finite element methods discontinuous Galerkin methods wave equation implicit methods energy method stability condition optimal error estimates

Can we improve renal function by partial nephrectomy?

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Asian Journal of Urology 2021年第4期8卷 448-449页

作者： samir Bouras samir Yebdri Kamal Adjali Department of Urology Faculty of MedicineFerhat Abbas University Setif 1SetifAlgeria Department of Urology Faculty of MedicineMouloud Mammeri UniversityTizi OuZouAlgeria Department of Urology Faculty of MedicineBenyoyucef Benkhedda University Algiers 1AlgiersAlgeria

to the editor:I had the pleasure of reading a very interesting,original article published recently by Zhang et al.[1]in your prestigious journal,entitled“Comparison of the oncological,perioperative and functional outcomes of partial nephrectomy versus radical nephrectomy for clinical t1b renal cell carcinoma:A systematic review and meta-analysis of retrospective studies”.the interest in partial nephrectomy(PN)remains relevant after all these years of standardizing PN for ct1 renal masses[2,3].As all similar publications,this technique cannot be talked about without praising it for the preservation of long-term renal function(RF)compared to radical nephrectomy,especially for patients with a chronic kidney disease(CKD)[1e3].this article contains no less than two references whose titles refer directly to the *** interest in this aspect comes from our thesis work on PN,where we noticed an improvement in postoperative RF and its maintenance over time,in some patients,even with CKD,whether in our study or elsewhere.

关键词： function journal editor

Protective effect of Citrus reticulata peel extract against potassium dichromate-induced reproductive toxicity in rats

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Asian pacific Journal of Reproduction 2019年第6期8卷 267-275页

作者： samir AE Bashandy Omar A-h Ahmed-Farid Enayat AOmara Sayed AEl-toumy Josline YSalib Pharmacology Department National Research Centre33 El-Bohouth St.DokkiP.O.12622GizaCairoEgypt Physiology Department National Organization for Drug Control and ResearchCairoEgypt Pathology Department National Research CentreCairoEgypt Chemistry of tannins Department National Research CentreCairoEgypt

Objective:to study the protective effect of Citrus reticulata peel extract against potassium dichromate-induced reproductive impairment in male Wistar ***:A total of 35 male Wistar rats were equally divided into 5 *** control group orally received an equivalent volume of saline(1 mL);group 2 was given potassium dichromate at 10 mg/kg/body weight(b.w.)orally for eight weeks;group 3 and 4 orally received Citrus reticulata peel extract at 200 and 400 mg/kg/***,followed by treatment with potassium *** 5 was administered with 400 mg/kg/*** reticulata peel extract *** parameters including oxidative stress(malondialdehyde,antioxidant enzymes),sex hormones(testosterone,luteinizing hormone,follicle-stimulating hormone)and inflammation indexes(tumor necrosis factor-alpha,inter leukin 6)were *** characteristics(sperm morphology,motility and count)were also ***:the decrease of male sex hormones concentration in plasma(testosterone,luteinizing hormone),testicular antioxidant parameters(reduced glutathione,catalase,superoxide dismutase,carnitine),sperm motility and sperm count induced by potassium dichromate was mitigated by Citrus reticulata peel ***,the peel extract alleviated the increase of sperm abnormalities,follicle-stimulating hormone,testicular malondialdehyde,tumor necrosis factor-alpha and nitric oxide levels caused by potassium *** sections of rats treated with the potassium dichromate were characterized by some histopathological changes as disorganization of spermatogonial cell layers and deformation of Leydig cells.A positive immune-reaction for p53 was observed in testicular cells of the rats treated with potassium *** extract of Citrus reticulata peel improved the testicular histology and decreased p53 positive immune-reaction in potassium dichromate administered ***:Citrus reticulata peel extract can alleviate the reproductive toxicity t

关键词： Citrus reticulatapeel extract Potassium dichromate Sperm testicular function Oxidative stress Anti-inflammatory

Volvulus of the ileal pouch-anal anastomosis:a meta-narrative systematic review of frequency,diagnosis,and treatment outcomes

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Gastroenterology Report 2019年第6期7卷 403-410,I0001页

作者： Muhammad Jawoosh samir haffar Parakkal Deepak Alyssa Meyers Amy L.Lightner David W.Larson Laura h.Raffals Mhassan Murad Navtej Buttar Fateh Bazerbachi Division of Gastroenterology and hepatology Dessau Municipal HospitalAuenweg 3806847 Dessau-RosslauGermany Digestive Center for Diagnosis and treatment DamascusSyrian Arab Republic Division of Gastroenterology John T.Milliken Department of MedicineWashington University School of MedicineSt.LouisMOUSA Division of Gastroenterology and hepatology Mayo ClinicRochesterMNUSA Department of Colorectal Surgery Cleveland ClinicClevelandOHUSA Division of Colon and Rectal Surgery Mayo ClinicRochesterMNUSA Robert D and Patricia E Kern Center for the Science of health Care Delivery Mayo ClinicRochesterMNUSA Division of Gastroenterology Massachusetts General HospitalBostonMAUSA

Background:Proctocolectomy with ileal pouch–anal anastomosis(IPAA)is the surgical procedure of choice for medically refractory ulcerative colitis and familial adenomatous *** rare,a pouch volvulus can *** aimed to determine the frequency,presentation,and management approach of pouch volvulus in patients with ***:A systematic search of published literature was performed by a medical reference librarian on 10 August 2018 and two independent reviewers identified relevant publications,extracted data,and assessed the methodological quality based on a validated tool.A retrospective review of the Mayo Clinic electronic medical records identified one case of pouch volvulus between January 2008 and August ***:the frequency of pouch volvulus from one large published study reporting long-termoutcomes of IPAA was 0.18%(3/1,700).A total of 22 patients(18 ulcerative colitis)were included(median age 32 years,73%females).Median time to volvulus after IPAA was 36 months while median interval to volvulus diagnosis from symptom onset was 24 *** pain was the most commonly reported symptom(76%).the diagnosis was made primarily by abdominal computed tomography(13/17 patients,76%).Endoscopic treatment was successful in 1 of 11 patients(9%).Surgery was performed in 20 patients and pouch-pexy and pouch excision were the most frequent surgical operations.A redo IPAA was performed in five patients(25%).Conclusion:Pouch volvulus is a rare but serious complication of IPAA and should be suspected even in the absence of obstruction *** treatment often fails and surgery is effective when performed early.

关键词： familial adenomatous polyposis ulcerative colitis ileal pouch–anal anastomosis pouch volvulus systematic review

Comparing the transmission potential from sequence and surveillance data of 2009 North American influenza pandemic waves

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Infectious Disease Modelling 2023年第1期8卷 240-252页

作者： Venkata R.Duvvuri Joseph t.hicks Lambodhar Damodaran Martin Grunnill thomas Braukmann Jianhong Wu Jonathan B.Gubbay samir N.Patel Justin Bahl Public health Ontario TorontoOntarioCanada Department of Laboratory Medicine and Pathobiology Faculty of MedicineUniversity of TorontoTorontoOntarioCanada Laboratory for Industrial and Applied Mathematics Department of Mathematics and StatisticsYork UniversityTorontoOntarioCanada Center for the Ecology of Infectious Disease Department of Infectious DiseasesInstitute of BioinformaticsUniversity of GeorgiaAthensGeorgia Department of Epidemiology and Biostatistics Institute of BioinformaticsUniversity of GeorgiaAthensGeorgia Duke-NUS Graduate Medical School Singapore

technological advancements in phylodynamic modeling coupled with the accessibility of real-time pathogen genetic data are increasingly important for understanding the infectious disease transmission *** this study,we compare the transmission potentials of North American influenza A(h1N1)pdm09 derived from sequence data to that derived from surveillance *** impact of the choice of tree-priors,informative epidemiological priors,and evolutionary parameters on the transmission potential estimation is *** American Influenza A(h1N1)pdm09 hemagglutinin(hA)gene sequences are analyzed using the coalescent and birth-death tree prior models to estimate the basic reproduction number(R_(0)).Epidemiological priors gathered from published literature are used to simulate the birth-death skyline ***-sampling marginal likelihood estimation is conducted to assess model fit.A bibliographic search to gather surveillancebased R_(0)values were consistently lower(mean≤1.2)when estimated by coalescent models than by the birth-death models with informative priors on the duration of infectiousness(mean≥1.3 to≤2.88 days).the user-defined informative priors for use in the birth-death model shift the directionality of epidemiological and evolutionary parameters compared to non-informative *** there was no certain impact of clock rate and tree height on the R_(0)estimation,an opposite relationship was observed between coalescent and birth-death tree *** was no significant difference(p=0.46)between the birth-death model and surveillance R0 *** study concludes that treeprior methodological differences may have a substantial impact on the transmission potential estimation as well as the evolutionary *** study also reports a consensus between the sequence-based R_(0)estimation and surveillanceased R_(0)***,these outcomes shed light on the potential role of phylodynamic modeling to augment existing surveillance

关键词： Phylodynamics Pandemic 2009 h1N1 Reproduction number Coalescent growth models Birth-death models Pathogen sequence data Public health

Antibody to El peptide of hepatitis C virus genotype 4 inhibits virus binding and entry to hepG2 cells in vitro

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World Journal of Gastroenterology 2006年第16期12卷 2530-2535页

作者： Mostafa K EL-Awady Ashraf A tabll Khaled Atef Samar S Yousef Moataza h Omran Yasmin EI-Abd Noha G Bader-Eldin Ahmad M Salem samir F Zohny Wael t EI-Garf Department of Biomedical technology National Research CenterCairoEgypt Department of Biochemistry Faculty of ScienceAin Shams UniversityCairoEgypt

AIM： to analyze the neutralizing activity of antibodies against E1 region of hepatitis C virus （hCV）. Specific polydonal antibody was raised via immunization of New Zealand rabbits with a synthetic peptide that had been derived from the E1 region of hCV and was shown to be highly conserved among hCV published genotypes. MEthODS： hyper-immune hCV E1 antibodies were incubated over night at 4 ℃ with serum samples positive for hCV RNA, with viral loads ranging from 615 to 3.2 million IU/mL. treated sera were incubated with hepG2 cells for 90 min. Blocking of viral binding and entry into cells by anti E1 antibody were tested by means of RtPCR and flow cytometry. RESULtS： Direct immunostaining using FItC conjugated E1 antibody followed by Flow cytometric analysis showed reduced mean fluorescence intensity in samples pre-incubated with E1 antibody compared with untreated samples. Furthermore, 13 out of 18 positive sera （72%） showed complete inhibition of infectivity as detected by Rt-PCR. CONCLUSION： In house produced E1 antibody, blocks binding and entry of hCV virion infection to target cells suggesting the involvement of this epitope in virus binding and entry. Isolation of these antibodies that block virus attachment to human cells are useful as therapeutic reagents.

关键词： Flow cytometry hepatitis C virus E1 envelope therapeutic antibodies Direct immuno-fluorescence hepG2 cells

Speed vernalization to accelerate generation advance in winter cereal crops

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Molecular Plant 2022年第8期15卷 1300-1309页

作者： Jin-Kyung Cha Kathryn O'Connor samir Alahmad Jong-hee Lee Eric Dinglasan hyeonjin Park So-Myeong Lee Dominique hirsz Soon-Wook Kwon Youngho Kwon Kyeong-Min Kim Jong-Min Ko Lee t.hickey Dongjin Shin Laura E.Dixon National Institute of Crop Science RDAMiryang 50424Korea School of Biology Faculty of Biological SciencesUniversity of LeedsLeeds LS29JTUK Queensland Alliance for Agriculture and Food Innovation The University of QueenslandSt.LuciaQLDAustralia Department of Plant Bioscience Pusan National UniversityMiryang 60463Korea

there are many challenges facing the development of high-yielding,nutritious crops for future *** limiting factor is generation time,which prolongs research and plant breeding *** advances in speed breeding protocols have dramatically reduced generation time for many short-day and long-day species by optimizing lightand temperature conditions during plant ***,winter crops with a vernalization requirement stillrequire upto 6-10weeks in low-temperature conditions before thetransition to ***,we tested a suite of environmental conditions and protocols to investigate whether the vernalization process can be *** identified a vernalization method consisting of exposing seeds at the soil surface to an extended photoperiod of 22 h day:2 h night at 10°C with transfer to speed breeding conditions that dramatically reduces generation time in both winter wheat(triticum aestivum)and winter barley(hordeum vulgare).Implementation of the speedvernalization protocolfollowed byspeedbreedingallowed the completion ofuptofivegenerations per yearforwinter wheat or barley,whereas only two generations can be typically completed under standard vernalization and plant growth *** speed vernalization protocol developed in this study has great potential to accelerate biological research and breeding outcomes for winter crops.

关键词： speed breeding photoperiod temperature wheat barley breeding

Association between IL-37 and VEGF Gene Expression in Psoriasis Pathogenesis in Egyptian Population

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Journal of Biosciences and Medicines 2022年第5期10卷 136-149页

作者： Sherif M. El-Sherbini Ahmed Kh. S. Salama Laila A. Rashed Mohamed h. Nafady samir A. M. El-Masry Genetic Engineering and Biotechnology Research Institute Al-Sadat University Al-Sadat Egypt Faculty of Applied Medical science Misr University for Science and Technology Giza Egypt Faculty of Medicine Cairo University Cairo Egypt

Background: Psoriasis is considered a common skin disease, marked by the production and elevation of inflammatory plaques that regularly shed scales resulting from extensive skin epithelial cell proliferation. t lymphocytes, neutrophils, and other leukocytes enter the irritated skin, resulting in epidermal keratinocyte hyperplasia, vascular hyperplasia, ectasia, and t lymphocyte, neutrophil other forms of leukocyte infiltration. Aim of the Work: the study aimed to investigate the role of IL-37 and VEGF gene expression in the pathogenesis of psoriasis in Egyptian patients. Methodology: Polymerase chain reaction techniques (PCR) were applied to detect VEGF in the skin homogenates of psoriasis patients. In addition, the ELIZA technique was applied to investigate IL-37 in skin homogenates. One hundred cases have been divided into two groups: 50 healthy volunteers as the group I healthy control;50 psoriasis patients as group II. PCR real-time technology was assessed through extracted DNA samples for VEGF amplification in skin homogenate. Result: Our results revealed that psoriasis patients significantly had a substantial reduction in IL-37 compared to the control group (p Conclusion: there is a significant inverse association between IL-37 and VEGF in psoriasis patients. Study findings revealed that IL-37 gene expression decreases while VEGF gene expression increases in psoriatic individuals. Such a measurement may be beneficial in determining the severity of the condition, as well as taking into consideration of the disease’s diagnosis.

关键词： IL-37 VEGF Gene Expression Psoriasis PCR