检索结果-南通市图书馆

Refined rigorous perturbation bounds for the SR decomposition

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Applied Mathematics:A Journal of Chinese Universities 2021年第4期36卷 537-553页

作者： Mahvish samar Aamir Farooq Department of Mathematics Shantou University College of Mathematics and Statistics Chongqing University

In this article, some new rigorous perturbation bounds for the SR decomposition under normwise or componentwise perturbations for a given matrix are derived. Also, the explicit expressions for the mixed and componentwise condition numbers are presented by utilizing the block matrix-vector equation approach. Hypothetical and trial results demonstrate that these new bounds are constantly more tightly than the comparing ones in the literature.

关键词： 65F35 15A23 15A57 SR decomposition Rigorous perturbation bound Lyapunov majorant function Banach fixed point theorem Mixed and componentwise condition numbers

Flux measurements for a DD neutron generator using neutron activation analysis

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2018年第4期29卷 66-71页

作者： Walid A. Metwally samar el-Sayed Ahmad Ababneh David L. Williams Allan X. Chen Department of Nuclear Engineering University of SharjahSharjah 27272 UAE Adelphi Technology 2003 E Bayshore Rd. Redwood CityCA 94063 USA

The fast and maximum thermal neutron fluxes from the DD-109 neutron generator at the University of Sharjah were experimentally measured by the activation technique using different neutron reactions. The thermal and fast neutron fluxes were found to be 2.960 × 10~6 and6.186 × 10~7 n/cm^2 s, respectively. This was done to verify the modeling results for the optimum moderator thickness needed to maximize the thermal neutron flux. The optimum moderator thickness was found to be between 3.5 and4 cm. The present data were compared with the detailed MCNP model-based calculation performed in earlier work to simulate the generator.

关键词： Neutron activation analysis Neutron generator Neutron moderation Thermal neutron flux measurement

维普期刊数据库

Human leukocyte antigen class-Ⅱ DRB1 alleles and Giardia lamblia infection in children: A case-control study

在线全文

学校读者我要写书评

暂无评论

Asian Pacific Journal of Tropical Medicine 2020年第2期13卷 56-61页

作者： samar N.el-Beshbishi Ayat A.elBlihy Raefa A.Atia Ahmed Megahed Fatma A.Auf Department of Medical Parasitology Faculty of MedicineMansoura UniversityMansoura 35516Egypt Pediatric Gastroenterology and Hepatology Unit Mansoura University Children's HospitalFaculty of MedicineMansoura UniversityMansoura 35516Egypt Department of Clinical Pathology Faculty of MedicineMansoura UniversityMansoura 35516Egypt

Objective:To compare the genotype frequencies of HLA class-ⅡDRB1 alleles in Giardia(G.)lamblia-infected ***:A total of 490 Egyptian children aged 2-16 years were subjected to microscopic stool examination to detect *** infection,and to exclude other intestinal *** the basis of their microscopic findings,a group of 80 children were chosen as giardiasis cases,another 80 children were confirmed as Giardia free control group by immunochromatographic test,and the remaining children were *** giardiasis and control groups were then subjected to blood examination to identify their genetic type of HLA-DRB1 ***:HLA class-ⅡDRB1*03:01 and DRB1*13:01 alleles were significantly associated with *** infection(Peles were significantly demonstrated in Giardia free ***,other HLA-DRB1 alleles did not show any significant association with ***:HLA class-ⅡDRB1*03,DRB1*13,DRB1*04,DRB1*10,DRB1*14 and DRB1*15 alleles may be involved in the establishment of host immune response to *** infection.

关键词： Giardia lamblia Giardiasis Human leukocyte antigen HLA class-ⅡDRB1 alleles Children

HepG2 cells support viral replication and gene expression of hepatitis C virus genotype 4 in vitro

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2006年第30期12卷 4836-4842页

作者： Mostafa K el-Awady Ashraf A Tabll Yasmine S el-Abd Mahmoud M Bahgat Hussein A Shoeb samar S Youssef Noha G Bader el Din el-Rashdy M Redwan Maha el-Demellawy Moataza H Omran Wael T el-Garf Said A Goueli Department of Biomedical Technology National Research Center Tahrir Street PO 12622 Dokki Cairo Egypt Department of Medicinal Chemistry Na- tional Research Center Tahrir Street PO 12622 Dokki Cairo Egypt Department of Microbiology and Immunology Faculty of Pharmacy Cairo University Cairo Egypt Genetic Engineering and Biotechnology Research Institute New Borg El-Arab City Alexandria Egypt Department of Pathology School of Medicine University of Wisconsin Madison WI United States

AIM： TO establish a cell culture system with longterm replication of hepatitis C virus （HCV） genome and expression of viral antigens in vitro. METHODS： HepG2 cell line was tested for its susceptibility to HCV by incubation with a serum from a patient with chronic hepatitis C. Cells and supernatant were harvested at various time points during the culture. Culture supernatant was tested for its ability to infect na＇ive cells. The presence of minus （antisense） RNA strand, and the detection of core and E1 antigens in cells were examined by RT-PCR and immunological techniques （flow cytometry and Western blot） respectively. RESULTS： The intracellular HCV RNA was first detected on d 3 after infection and then could be consistently detected in both cells and supernatant over a period of at least three months. The fresh cells could be infected with supernatant from cultured infected cells. Flow cytometric analysis showed surface and intracellular HCV antigen expression using in house made polyclonal antibodies （anti-core, and anti-E1）. Western blot analysis showed the expression of a cluster of immunogenic peptides at molecular weights extended between 31 and 45 kDa in an one month old culture of infected cells whereas this cluster was undetectable in uninfected HepG2 cells. CONCLUSION： HepG2 cell line is not only susceptible to HCV infection but also supports its replication in vitro. Expression of HCV structural proteins can be detected in infected HepG2 cells. These cells are also capable of shedding viral particles into culture media which in turn become infectious to uninfected cells.

关键词： Hepatitis C virus In vitro propagation Genomic replication Gene expression HepG2 cells

A need for stratification of metastasis samples according to secondary site in gene expression studies

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

BIOCelL 2022年第7期46卷 1747-1750页

作者： IVANA samarŽIJA Laboratory for Epigenomics Division of Molecular MedicineRuđer BoškovićInstituteZagreb10000Croatia Laboratory for Cell Biology and Signaling Division of Molecular BiologyRuđer BoškovićInstituteZagreb10000Croatia

Comparisons of gene expression profiles between primary tumors and metastasis have revealed genes that are implicated in metastasis ***,gene expression studies conducted on metastasis samples from the same primary site usually do not discriminate between different secondary *** the change in the expression of number of genes is expected to be common to metastasis from the same primary but different secondary sites,herein the data that point to substantial differences are ***,the reciprocal communication between metastatic and host cells that is influencing these differences is outlined to emphasize the need for stratification of metastasis samples in gene expression studies.

关键词： Bone metastasis Brain metastasis Liver metastasis Lung metastases Gene expression

Complexity of Gold(Ⅲ)Ion With Cefotaxime and Cefepime Drugs:Spectroscopic,Antimicrobial and Antitumor Discussions

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

光谱学与光谱分析 2020年第10期40卷 3315-3320页

作者： Lamia A Albedair samar O Aljazzar Mohamed I Kobeasy Moamen S Refat College of Science Princess Nourah bint Abdulrah man UniversityDepartment of ChemistrySaudi Arabia Department of Biochemistry Faculty of AgricultureCairo UniversityGizaEgypt Department of Chemistry Faculty of ScienceTaif UniversityAl-HawiahTaif 21974Saudi Arabia Department of Chemistry Faculty of SciencePort Said UniversityPort SaidEgypt

The availability of chemical and biological data presented in this paper is the basis for understanding not only the current state of anti-cancer drugs based on gold(Ⅲ),but also the rationale for strategies for future drug *** Au(Ⅲ)nanosized complexes of cefotaxime(ceph-3)and cefepime(ceph-4)ligands as a 3rd and 4th of cephalosporin generation drugs were ***(Ⅲ)complexes were discussed based on the elemental,molar conductance,thermal and magnetic moment measurements as well as spectral(FTIR,1HNMR,UV-Vis,and XRD)***-IR spectra revealed that the ceph-3 and ceph-4 ligands reacted as a bidentate ligands through carboxylate oxygen andβ-lactam oxygen *** analytical analysis confirm that the molar ratio is 1∶1(Au 3+/ceph)with general formula[Au(L)(Cl)2]where L=ceph-3 or *** structures of Au(Ⅲ)complexes were presence as a square planar geometry.X-ray diffraction patterns referred to a crystalline nature for all synthesized *** analyses confirmed that the synthetic gold(Ⅲ)complexes have a nanosized *** vitro antimicrobial activities of Au(Ⅲ)complexes were evaluated towards two types of bacteria(G+&G-).The antitumor activities of gold(Ⅲ)complexes are appraised against breast(MCF-7)and colorectal adenocarcinoma(Caco-2)cell lines,which means that the two complexes may consider promising anticancer drugs.

关键词： Cefotaxime sodium Cefepime hydrochloride Complexity Gold(Ⅲ)ions Nanoscale Structure anticancer

维普期刊数据库

Structured condition numbers and statistical condition estimation for the LDU factorization

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics(A Journal of Chinese Universities) 2020年第3期35卷 332-348页

作者： Mahvish samar Aamir Farooq MU Chun-lai College of Mathematics and Statistics Chongqing UniversityChongqing 401331China

In this article, we consider the structured condition numbers for LDU, factorization by using the modified matrix-vector approach and the differential calculus, which can be represented by sets of parameters. By setting the specific norms and weight parameters, we present the expressions of the structured normwise, mixed, componentwise condition numbers and the corresponding results for unstructured ones. In addition, we investigate the statistical estimation of condition numbers of LDU factorization using the probabilistic spectral norm estimator and the small-sample statistical condition estimation method, and devise three algorithms. Finally, we compare the structured condition numbers with the corresponding unstructured ones in numerical experiments.

关键词： LDU factorization Structured condition number Normwise condition number Mixed condition number Componentwise condition number

维普期刊数据库

Chemiluminescence Determination of Cefixime Trihydrate Based on Acidic Diperiodatoargentate(Ⅲ)-Rhodamine 6-G System

在线全文

学校读者我要写书评

暂无评论

Chemical Research in Chinese Universities 2019年第5期35卷 775-781页

作者： MUHAMMAD Yousaf MOHAMMED Yaqoob MUHAMMAD Asghar samar Ali Department of Chemistry University cf BalochistanQuetta 87300Pakistan

A novel chemiluminescence(CL) method is proposed for cefixime trihydrate(CFX) determination based on its eiiliancement effect on diperiodatoargentate(III)(DPA)-rhodamine 6-G(Rh6-G) reaction in conjunction with flow injection analysis(FIA). A linear calibration curve was achieved over the range from 0.01 mg/L to 2.5 mg/L CFX(R^2=0.999,n=8) with relative standard deviation(RSD) of 1.4%-3.8%(n=4)), limit of detection(LOD) of 3.0×10^-3 mg/L(S/N=3),injection tliroughput of 180/h and regression equation of y=1113.2x-14.596[y=CL intensity (mV) and x=concentration of CFX(mg/L)]. The method was successfully applied to CFX determination in pharmaceutical formulations and the recoveries(%) for proposed FI-CL and a reported spectrophotometric method by applying the Student t-test [calculated t-test value: t=1.079215, and tabulated t-distributed(95%)=2.200985] were not significantly diflerent. The CFX was efficiently extracted and no significant effect of commonly found excipients in the pharmaceutical formulations was observed. The mechanism of CL reaction is discussed briefly.

关键词： Cehxime trihydrate Diperiodatoargentate(Ⅲ) Rhodamine 6-G Chemiluminescence Flow injection analysis Phannaceutical formulation

An Automated Real-Time Face Mask Detection System Using Transfer Learning with Faster-RCNN in the Era of the COVID-19 Pandemic

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2022年第5期71卷 4151-4166页

作者： Maha Farouk S.Sabir Irfan Mehmood Wafaa Adnan Alsaggaf Enas Fawai Khairullah samar Alhuraiji Ahmed S.Alghamdi Ahmed A.Abd el-Latif Department of Information Systems Faculty of Computing and Information TechnologyKing Abdulaziz UniversitySaudi Arabia Centre for Visual Computing Faculty of Engineering and InformaticsUniversity of BradfordBradfordU.K Department of Information Technology Faculty of Computing and Information TechnologyKing Abdulaziz UniversityJeddahP.O.Box 23713Saudi Arabia Department of Computer Science Faculty of Computing and Information TechnologyKing Abdulaziz UniversityJeddahSaudi Arabia Department of Cybersecurity College of Computer Science and EngineeringUniversity of JeddahSaudi Arabia Department of Mathematics and Computer Science Faculty of ScienceMenoufia University32511Egypt

Today,due to the pandemic of COVID-19 the entire world is facing a serious health *** to the World Health Organization(WHO),people in public places should wear a face mask to control the rapid transmission of *** governmental bodies of different countries imposed that wearing a face mask is compulsory in public ***,it is very difficult to manually monitor people in overcrowded *** research focuses on providing a solution to enforce one of the important preventative measures of COVID-19 in public places,by presenting an automated system that automatically localizes masked and unmasked human faces within an image or video of an area which assist in this outbreak of *** paper demonstrates a transfer learning approach with the Faster-RCNN model to detect faces that are masked or *** proposed framework is built by fine-tuning the state-of-the-art deep learning model,Faster-RCNN,and has been validated on a publicly available dataset named Face Mask Dataset(FMD)and achieving the highest average precision(AP)of 81%and highest average Recall(AR)of 84%.This shows the strong robustness and capabilities of the Faster-RCNN model to detect individuals with masked and un-masked ***,this work applies to real-time and can be implemented in any public service area.

关键词： COIVD-19 deep learning faster-RCNN object detection transfer learning face mask