检索结果-南通市图书馆

Post-synthetic metalation of organic cage for enhanced porosity and catalytic performance

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China Chemistry 2023年第6期66卷 1763-1770页

作者： Miao Yang Xun Chen Yifei Xie el-sayed Mel-sayed Ning Xu Wenjing Wang Kongzhao Su Daqiang Yuan State Key Lab of Structure Chemistry Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou 350002China University of the Chinese Academy of Sciences Beijing 100049China College of Chemistry Fuzhou UniversityFuzhou 310116China Chemical Refining Laboratory Refining DepartmentEgyptian Petroleum Research InstituteNasr City 11727Egypt

Porous organic cages(POCs)have shown great potential in many applications,and post-synthetic modification(PSM)has been confirmed to be an effective strategy to tailor their structures and related ***,it is extremely challenging to develop a general platform for simple-to-make functional POCs for advanced applications by PSM ***,we reported that octahedral calix[4]resorcinarene-based hydrazone-linked porous organic cage(HPOC-401)provides an excellent platform for post-synthetic metalation by various transition metal(TM)ions under mild conditions due to the abundance of coordination sites in its *** metalated products(HPOC-401-TM)exhibit Brunauer-Emmett-Teller(BET)surface area up to1,456 m^(2)g^(-1),much higher than that of the pristine HPOC-401,which has a BET value of 474 m^(2)g^(-1).Moreover,the metalation and porosity increases further influence their gas capture,separation,as well as catalytic *** instance,HPOC-401-TM products exhibit higher CO_(2),H_(2),and C2 hydrocarbon gas uptake,as well as higher C_(2)H_(6)/C_(2)H_(4) selectivity than ***,the HPOC-401-TM also shows better catalytic performance in the cycloaddition of CO_(2) with epoxides compared to *** findings uncover a simple yet effective approach for modifying the porosity characteristics of organic cages,which will undoubtedly expand their future implementations.

关键词： porous organic cage(POC) calixresorcinarene post-synthetic metalation(PSM) gas adsorption and separation CO_(2)cycloaddition

Air renewal times and ventilation rate calculations for underground workings using radioactive measurement

在线全文

学校读者我要写书评

暂无评论

International Journal of Mining Science and Technology 2016年第5期26卷 843-850页

作者： Ayman A.el-Abnoudy sayed F.Hassan Production Sector Nuclear Materials Authority

Potential alpha emitters are of prime concern to the ventilation engineer due to their rapid concentration increasing once radon released in the mine atmosphere, causing tissue irradiation and lung *** of the time based variations of the natural ventilation in tunnels and their relationship to the external parameters contribute to the air circulation assessment. Due to the continuous and high fluctuation of the meteorological conditions affecting the air circulation and intensity through the underground workings, there is a difficulty in the natural ventilation assessment by only the ordinary meteorological measurements. So, in this paper, the possibility of using the radioactive measurements, allowing for the air aging and ventilation quality to be qualified, is investigated through three different underground structures. Referring to the most confined structure of them, results show that one structure has a better exchange rate by a factor 1.8 and the other has the best rate by a factor 2.1. This parameter can be linked to the operating costs and size of a future ventilation system.

关键词： Mining ventilation Air circulation Radon gas measurement Air aging

Molecular study of astrovirus, adenovirus and norovirus in community acquired diarrhea in children: One Egyptian center study

在线全文

学校读者我要写书评

暂无评论

Asian Pacific Journal of Tropical Biomedicine 2017年第11期7卷 987-990页

作者： Maysaa el sayed Zaki Nermen Abo el Kheir Clinical Pathology Department Mansoura Faculty of MedicineMansoura UniversityEgypta

Objective: To determine the prevalence of astrovirus, norovirus, adenovirus in children below five years old with diarrhea by multiplex reverse transcriptase polymerase chain reaction(RT-PCR) along with rotavirus antigen detection by enzyme linked immunosorbant ***: The study was conducted on children below five years old complaining of acute diarrhea. The study included stool examination by molecular method for detection of norovirus, adenovirus and astrovirus by multiplex RT-PCR. Rotavirus antigen was detected in the stool by enzyme linked immunosorbant ***: The study included 100 children below 5 years old with acute *** RT-PCR was positive in 34% of the children. The most frequently detected virus was rotavirus(44%), followed by norovirus(30%), adenovirus(20%) and astrovirus(14%). The clinical symptoms were more significantly associated with viral diarrhea such as fever(P = 0.03), bloody diarrhea(P = 0.025), vomiting(P = 0.000 1) and watery diarrheas(P = 0.05). The frequency of diarrhea with viral pathogen was significantly presented in winter season(39.7%). There were significant frequencies of norovirus and adenovirus in age ranging 1–2 years old(P = 0.04, P = 0.01 respectively).Conclusions: The present study spotlights on the prevalence of viral pathogens as an important etiology in diarrhea in children below five years old. Astrovirus, norovirus and adenovirus are common along with rotavirus in this group of patients. Multiplex PCR leads to improve the laboratory diagnosis of these viruses along with antigen detection method. Further longitudinal studies are required to evaluate the epidemiological data associated with these viruses and for proper management of such drastic infection.

关键词： Diarrhea Astrovirus Adenovirus Norovirus Multiplex-RT PCR

Correlation of biofilm formation of uropathogenic Escherichia coli(UPEC) and fimbriae genotypes

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Asian Pacific Journal of Tropical Medicine 2009年第5期2卷 49-53页

作者： Maysaa el sayed Zaki Clinical Pathology Department Faculty of Medicine-Mansoura UniversityEgypt

Objective:In the present study we try to correlate between pathogenic intrinsic factor of Escherichia coli(***) presented with different fimbria genotyes and biofilm formation with host immune factor entitled interleukin-6(IL-6) secretion as defense ***:A total of 91 pediatrics complaining of pyuria were included in the present *** addition,20 healthy control children were *** microbiological study was performed for isolated *** alleles were studied by multiple alleles PCR and biofilm formation was ***-6 was measured in ***:IL-6 had statistically significant elevation in patients’urine compared to *** biofilm study, it was found that 19 isolated *** had formed biofilm in ***,urine samples with positive biofilm formation of *** had statistically significant lower IL-6 secretion than those with negative *** for *** distribution of fimbria genotypes showed that the frequent genotype was for alleleⅠ(34.3%) followed by mixed allelesⅠandⅡ(24.1%).There was significant correlation between mixed alleles(Ⅰ&Ⅱ)and biofilm ***: The present study highlights the presence of significant strains of *** causing urinary tract infections capable of biofilm *** formation is associated with less innate immunity manifested by lower urinary IL- *** majority of isolates had fimbria *** appears that mixed allelesⅠandⅡhave prominent virulence effect with tendency for biofilm formation.

关键词： Uropathogenic Escherichia coli Interleukin -6(IL-6) Urinary tract infection Biofilm

Otoacoustic emissions value in patients with idiopathic sudden sensorineural hearing loss

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Otology 2022年第4期17卷 183-190页

作者： Aya el-sayed el-sayed Gaafar elshahat Ibrahem Ismail Hesham Saad Zaghloul Ministry of Health Egypt ENT Department Faculty of MedicineMansoura UniversityEgypt

Objectives:This study aimed to determine the prognostic value of otoacoustic emissions(OAEs)in idiopathic sudden sensorineural hearing loss ***:The study included 30 subjects with unilateral idiopathic sudden sensorineural hearing loss(ISSNHL).Each patient was evaluated four times:at baseline and after one week,one month,and three months of *** each visit,each patient was subjected to full audiological history,otoscopic examination,basic audiological evaluations,and transiently evoked and distortion product otoacoustic emission(TEOAEs&DEOAEs).Results:The hearing thresholds(frequency range 250e8000 Hz)and word recognition scores of patients with detectable TEOAEs and DPOAEs improved significantly,whereas no significant improvements were observed in those with no ***:Hearing improvement is better in patients with detectable TEOAEs and *** a result,TEOAEs and DPOAEs are recommended as routine tests in all SSNHL patients to predict outcomes and monitor treatment as TEOAEs and DPOAEs reflect the cochlear OHCs activity.

关键词： Sudden sensorineural hearing loss Transiently evoked otoacoustic emission Distortion product otoacoustic emission Outer hair cells

Optimization Ensemble Weights Model for Wind Forecasting System

在线全文

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2022年第11期73卷 2619-2635页

作者： Amel Ali Alhussan el-sayed M.el-kenawy Hussah Nasser AlEisa M.el-SAID sayed A.Ward Doaa Sami Khafaga Department of Computer Sciences College of Computer and Information SciencesPrincess Nourah bint Abdulrahman UniversityRiyadh11671Saudi Arabia Department of Communications and electronics Delta Higher Institute of Engineering and TechnologyMansoura35111Egypt Faculty of Artificial Intelligence Delta University for Science and TechnologyMansoura35712Egypt electrical Engineering Department Faculty of EngineeringMansoura UniversityMansoura35516Egypt Delta Higher Institute of Engineering and Technology(DHIET) Mansoura35111Egypt Department of electrical Engineering Faculty of Engineering at ShoubraBenha UniversityCairo11629Egypt Faculty of Engineering Delta University for Science and TechnologyGamasaMansoura11152Egypt

Effective technology for wind direction forecasting can be realized using the recent advances in machine ***,the stability and safety of power systems are expected to be significantly ***,the unstable and unpredictable qualities of the wind predict the wind direction a challenging *** paper proposes a practical forecasting approach based on the weighted ensemble of machine learning *** weighted ensemble is optimized using a whale optimization algorithm guided by particle swarm optimization(PSO-Guided WOA).The proposed optimized weighted ensemble predicts the wind direction given a set of input *** conducted experiments employed the wind power forecasting dataset,freely available on Kaggle and developed to predict the regular power generation at seven wind farms over forty-eight *** recorded results of the conducted experiments emphasize the effectiveness of the proposed ensemble in achieving accurate predictions of the wind *** addition,a comparison is established between the proposed optimized ensemble and other competing optimized ensembles to prove its ***,statistical analysis using one-way analysis of variance(ANOVA)and Wilcoxon’s rank-sum are provided based on the recorded results to confirm the excellent accuracy achieved by the proposed optimized weighted ensemble.

关键词： Guided Whale Optimization Algorithm(Guided WOA) forecasting machine learning weighted ensemble model wind direction

Value of avidity index of IgG and polymerase chain reaction in diagnosis of herpes simplex 2 virus in pregnancy

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Asian Pacific Journal of Tropical Medicine 2009年第2期2卷 30-34页

作者： Maysaa el sayed Zaki Clinical Pathology Faculty of MedicineMansoura UniversityEgypt

Objective:The goal of the present study is to highlight the significance of the determination of IgG avidity to herpes simplex2virus(HSV2) compared to detection of viremia by polymerase chain reaction(PCR) in relation to recurrent ***:Serum samples from pregnant patients with bad obstetric histories and control subjects were analyzed for quantitative determination of IgG specific for HSV2 by using elISA with and without sample treatment with 8 M urea as protein-denaturing agents for measurement of avidity index(AI).PCR was performed for samples to determine HSV2 ***:Regarding avidity index 11.5%had avidity index = 100.0,11.5%has avidity index = 47%and 76.9%had avidity index>60%.Control group had AI>70%.There was statistically insignificant difference between OD of IgG in patients with viremia before urea treatment and after urea treatment compared to healthy *** there was statistically insignificant difference in OD before urea and after urea in patients with ***:From this study we can conclude that viremia for HSV2 is common finding in patients with bad obstetric *** avidity immunoglobulin G was not common finding in those *** may be explain that even reactivation of latent HSV 2 infection is associated with fetal loss.

关键词： Herpes simplex 2 PCR IgG avidity test

Numerical simulation and analysis of confined turbulent buoyant jet with variable source

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 2015年第6期27卷 955-968页

作者： el-AMIN Mohamed F. AL-GHAMDI Abdulmajeed salama Amgad SUN Shuyu Mathematics Department Faculty of ScienceAswan University Computational Transport Phenomena Laboratory(CTPL) Division of Physical Sciences and Engineering(PSE)King Abdullah University of Science and Technology(KAUST) College of Engineering and Islamic Architecture Umm Al-Qura University

In this work, experimental and numerical investigations are undertaken for confined buoyant turbulent jet with varying inlet temperatures. Results of the experimental work and numerical simulations for the problem under consideration are presented. Four cases of different variable inlet temperatures and different flow rates are considered. The realizable k-ε turbulence model is used to model the turbulent flow. Comparisons show good agreements between simulated and measured results. The average devia- tion of the simulated temperature by realizable k-ε turbulent model and the measured temperature is within 2%. The results indicate that temperatures along the vertical axis vary, generally, in nonlinear fashion as opposed to the approximately linear varia- tion that was observed for the constant inlet temperature that was done in a previous work. Furthermore, thermal stratification exits, particularly closer to the entrance region. Further away from the entrance region the variation in temperatures becomes relatively smaller. The stratification is observed since the start of the experiment and continues during the whole course. Numerical experime- nts for constant, monotone increasing and monotone decreasing of inlet temperature are done to show its effect on the buoyancy force in terms of Richardson number.

关键词： realizable k-ε model turbulent jet stratification heat stores CFD

Yttria Tetragonal Zirconia Biomaterials:Kinetic Investigation

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2011年第4期27卷 332-337页

作者： Ezzat S.elshazly S.M.el-Hout M.el-sayed Ali Department of Mechanical Engineering Virginia Commonwealth University Deptartment of Metallurgy Nuclear Research CenterAtomic Energy Authority

The low temperature aging behavior of polycrystalline tetragonal zirconia was investigated to explore the effects on phase transformation occurring during the process. XRD analysis was conducted for the phase identification and the tetragonal to monoclinic phase transformation was determined. The aging of tetragonal zirconia polycrystals doped with 3 mol% Y203 triggers tetragonal to monoclinic phase transformation on the surface of the specimen only, while the penetration inside the bulk of the specimen is very limited. A slight decrease in the mechanical properties was also observed after aging for 40 h. The transformation kinetics show a nucleation and growth mechanism on the specimen surface to be dominant in the low temperature aging in water environment.

关键词： Low temperature degradation 3Y-TZP Kinetics