检索结果-南通市图书馆

Hepatic and gastrointestinal disturbances in Egyptian patients infected with coronavirus disease 2019: A multicentre cohort study

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 2021年第40期27卷 6951-6966页

作者： Hend Ibrahim Shousha Shimaa Afify Rabab maher Noha Asem Eman fouad Ehab f Mostafa Mohammed A Medhat Amr Abdalazeem Hazem elmorsy Miriam M Aziz Rateba S Mohammed Mohamed Ibrahem Hassan elgarem Dalia Omran Mohamed Hassany Bassem elsayed Ahmed Y Abdelaziz Mohamed el Kassas Endemic Medicine Faculty of MedicineCairo UniversityCairo 11562Egypt Gastroenterology Department National Hepatology&Tropical Medicine Research InstituteCairo 11563Egypt Hepatology Department Students HospitalCairo UniversityGiza 12566Egypt The Public Health Department Faculty of MedicineCairo UniversityCairo 11562Egypt Egyptian Ministry of Health and PopulationCairo 11567Egypt Department of Tropical Medicine and Gastroenterology Faculty of MedicineAssiut UniversityAssiut 15655Egypt Endemic Medicine Department Faculty of MedicineHelwan UniversityCairo 13544Egypt Internal Medicine 15 Mayo Smart HospitalMinistry of Health and PopulationCairo 13488Egypt Pediatrics Department Faculty of MedicineCairo UniversityCairo 11562Egypt Occupational and Environmental Medicine Department Faculty of MedicineCairo UniversityCairo 11562Egypt Clinical Biochemistry Department Faculty of medicineCairo UniversityCairo 11562Egypt Endemic Medicine Department Faculty of MedicineCairo UniversityCairo 11562Egypt Urology Department Cairo UniversityCairo 11562Egypt

BACKGROUND Various liver and gastrointestinal involvements occur in patients with coronavirus disease 2019(COVID-19)at variable *** studies report mild liver function disturbances correlated with COVID-19 severity,though liver failure is *** To study liver and gastrointestinal dysfunctions in Egyptian patients with COVID-19 and their relation to disease outcomes METHODS This multicentre cohort study was conducted on 547 Egyptian patients from April 15,2020 to July 29,*** polymerase chain reaction-confirmed COVID-19 cases were included from four quarantine hospitals affiliated to the Egyptian ministry of *** information,laboratory characteristics,treatments,fibrosis-4(fIB-4)index,COVID-19 severity,and outcomes were recorded and compared according to the degree of liver enzyme elevation and the presence of gastrointestinal ***-ups were conducted until discharge or *** analyses were performed to determine the independent factors affecting *** This study included 547 patients,of whom 53(9.68%)died during hospitalization and 1 was discharged upon his ***’mean age was 45.04±17.61 years,and 21.98%had severe or critical *** aminotransferase(ALT)and aspartate aminotransferase(AST)were available for 430 and 428 patients,*** total,26%and 32%of patients had elevated ALT and AST,*** liver injury with ALT or AST elevation exceeding 3-fold was recorded in 21(4.91%)and 16(3.73%)patients,*** gender,smoking,hypertension,chronic hepatitis C,and lung involvement were associated with elevated AST or *** was elevated in 50%of patients over ***-4 was significantly higher in patients admitted to the intensive care unit(ICU),those with more severe COVID-19,and *** independent variables affecting outcome were supplementary vitamin C intake(1 g daily capsules)[odds ratio(OR):0.05,95%confidence interval(CI

关键词： COVID-19 Egypt Liver injury Gastrointestinal symptoms fibrosis-4 Liver enzymes

Modeling and forecasting of COVID-19 using a hybrid dynamic model based on SEIRD with ARIMA corrections

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Infectious Disease Modelling 2021年第1期6卷 98-111页

作者： maher Ala’raj Munir Majdalawieh Nishara Nizamuddin Department of Information Systems College of Technological InnovationZayed UniversityDubai19282United Arab Emirates

The outbreak of novel coronavirus(COVID-19)attracted worldwide *** has posed a significant challenge for the global economies,especially the healthcare *** with a robust healthcare system,countries were not prepared for the ramifications of *** statistical,dynamic,and mathematical models of the COVID-19 outbreak including the SEIR model have been developed to analyze the infection its transmission *** objective of this research is to use public data to study the properties associated with the COVID-19 pandemic to develop a dynamic hybrid model based on SEIRD and ascertainment rate with automatically selected *** proposed model consists of two parts:the modified SEIRD dynamic model and ARIMA *** fit SEIRD model parameters against historical values of infected,recovered and deceased population divided by ascertainment rate,which,in turn,is also a parameter of the *** of the first model for infected,recovered,and deceased populations are then corrected using ARIMA *** model can analyze the input data in real-time and provide long-and short-term forecasts with confidence *** model was tested and validated on the US COVID statistics dataset from the COVID Tracking *** validation,we use unseen recent statistical *** use five common measures to estimate model prediction ability:MAE,MSE,MLSE,Normalized MAE,and Normalized *** proved a great model ability to make accurate predictions of infected,recovered,and deceased *** output of the model can be used by the government,private sectors,and policymakers to reduce health and economic risks significantly improved consumer credit scoring.

关键词： COVID 19 Coronavirus SEIRD model ARIMA Hybrid model

Recent advances in the synthesis and energetic properties of potassium-based potential green primary explosives

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2022年第11期18卷 1945-1959页

作者： Qamar-un-Nisa Tariq Saira Manzoor maher-un-Nisa Tariq Wen-Li Cao Jian-Guo Zhang State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing100081China Department of Chemistry University of OkaraOkara56300Pakistan

Primary explosives are utilized as a reliable initiator for secondary explosives in an extensive range of military and civilian operations. Heavy-metal-based primary explosives are moderate performing, more sensitive, and environmentally hazardous, posing a direct and indirect threat to health and ***, heavy-metal-based primaries have been replaced by environment-friendly metal-based primary explosives, such as potassium complexes. This review presents not only a summary of the current progress of new-generation potassium-based primary explosives and their methods of preparation, energetic properties, and applications, but also a further comparison with traditional primary explosives. In addition, this work discusses the necessity of heavy metal-free primary explosives and the major challenges faced in replacing traditional primary explosives.

关键词： Green primary explosives Heterocyclic compounds Synthesis Energetic properties

Characterization of Radiation Prepared Copolymer and Studies of Their Biodegradability

在线全文

学校读者我要写书评

暂无评论

Journal of Biosciences and Medicines 2018年第2期6卷 33-56页

作者： Nabila Ahmed Maziad Amany Badr el-Deen Abd el-Aziz Sabrnal el-Hamouly maher Abd el-Aziz Mahmoud el-Hashish Sameh A. Rizk Nada Rabie Nasef Department of Polymer Chemistry National Centre for Radiation Research and Technology Atomic Energy Authority Nasr City Egypt Microbiology Department National Centre for Radiation Research and Technology Atomic Energy Authority Nasr City Egypt Department Polymer Chemistry Faculty of Science Manoufia University Al Minufya Egypt Department Organic Chemistry Faculty of Science Ain Shams University Cairo Egypt

Blends of biodegradable copolymer based on starch, poly lactic acid (PLA), poly vinyl alcohol (PVA) and natural rubber (NR) have been prepared. Gamma radiation induced synthesis and modification of polymer hydrogel was studied. The polymer blends have been chemically surface modified by glycerol. The modified polymer blends have been investigated for swelling ratio, tensile strength and 9 scanning electron microscopy. The swelling ratio of polymer blends increased significantly after surface modification with glycerol. The swelling of polymer was decreased as a function of (NR) content in polymer blends. The gel fraction (PVA-starch-PLA) and (PVA-starch-NR) blends increased by increasing the radiation doses (kGy) to reach the maximum amount of (~99%) and (~88.2%), respectively. Addition of 2.5% (PLA) led to greater increase of the swelling ratio than 10% (NR) to blends and the maximum swelling was found at dose (5 kGy). At concentration of glycerol (5.0% w/w), tensile strength decreased and elongation at break % increased. The polymers degrading microorganisms were isolated from soil samples. The degradation ability of the microbial isolates for each polymeric material was tested on agar plates. Among these isolates, the most efficient degrader isolates for prepared blends in MSM shaking flasks were selected and the degradation was confirmed by scanning electron microscopy.

关键词： Radiation Biodegradation (NR) (PLA) Renewable Resources Mechanical Properties Scanning electron Microscopy

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

射频感应等离子体反应沉积碳化钨

中国有色金属学报 2003年第2期13卷 289-293页

作者：蒋显亮 maher Boulos 中南大学材料科学与工程学院长沙410083 Department of Chemical Engineering University of Sherbrooke Sherbrooke

用射频感应等离子体将钨粉炭化成碳化钨,对炭化过后的粉末在氩气保护下,于1900℃进行烧结处理,并对在感应等离子体中钨粉被甲烷炭化的反应过程和在高温基体上碳与沉积物进一步反应的机理进行了研究。采用扫描电镜和X射线衍射仪分析了原... 详细信息

用射频感应等离子体将钨粉炭化成碳化钨,对炭化过后的粉末在氩气保护下,于1900℃进行烧结处理,并对在感应等离子体中钨粉被甲烷炭化的反应过程和在高温基体上碳与沉积物进一步反应的机理进行了研究。采用扫描电镜和X射线衍射仪分析了原始钨粉、炭化粉末和反应沉积物的显微组织和成分。结果表明,快速炭化反应开始于金属钨粉熔化后,颗粒尺寸为5μm的钨粉在等离子体中被部分炭化,完全炭化要靠反应沉积物在高温基体上与碳的进一步反应来实现,经炭化的钨粉在热处理时存在脱碳现象。

关键词：射频感应等离子体沉积碳化钨钨粉炭化甲烷热处理脱碳

An Improved Deep Structure for Accurately Brain Tumor Recognition

在线全文

学校读者我要写书评

暂无评论

Computer Systems Science & Engineering 2023年第8期46卷 1597-1616页

作者： Mohamed maher Ata Reem N.Yousef faten Khalid Karim Doaa Sami Khafaga Department of Communications and electronics Engineering MISR Higher Institute for Engineering and TechnologyMansoura35516Egypt Department of.electronics and Communications Delta Higher Institute for Engineering and TechnologyMansoura35516Egypt Department of Computer Sciences College of Computer and Information SciencesPrincess Nourah bint Abdulrahman UniversityP.O.Box 84428Riyadh11671Saudi Arabia

Brain neoplasms are recognized with a biopsy,which is not commonly done before decisive brain *** using Convolutional Neural Networks(CNNs)and textural features,the process of diagnosing brain tumors by radiologists would be a noninvasive *** paper proposes a features fusion model that can distinguish between no tumor and brain tumor types via a novel deep learning *** proposed model extracts Gray Level Co-occurrence Matrix(GLCM)textural features from MRI brain tumor ***,a deep neural network(DNN)model has been proposed to select the most salient features from the ***,it manipulates the extraction of the additional high levels of salient features from a proposed CNN ***,a fusion process has been utilized between these two types of features to form the input layer of additional proposed DNN model which is responsible for the recognition *** common datasets have been applied and tested,Br35H and figShare *** first dataset contains binary labels,while the second one splits the brain tumor into four classes;glioma,meningioma,pituitary,and no ***,several performance metrics have been evaluated from both datasets,including,accuracy,sensitivity,specificity,f-score,and training *** results show that the proposed methodology has achieved superior performance compared with the current state of art *** proposed system has achieved about 98.22%accuracy value in the case of the Br35H dataset however,an accuracy of 98.01%has been achieved in the case of the figShare dataset.

关键词： Brain tumor convolutional neural network gray level co-occurrence matrix noninvasive figShare dataset Br35H dataset

Image Based Smoke Detection Using Source Separation

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 2019年第3期39卷 982-989页

作者： Ouiem Bchir Mohamed maher Ben Ismail Norah Asiri Computer Science Department College of Computer and Information SciencesKing Saud University

In this paper, we propose an automatic image based smoke detection using source separation. In particular, we assume that the region of interest(smoke region) is a linear combination of smoke and background pixels, and we estimate the smoke component. More specifically, we extend the linear hyperspectral unmixing techniques to the context of image based smoke detection in order to separate the smoke component from the background. The proposed approach yields promising results especially with smoke images captured outdoor.

关键词： Pattern recognition Computer science Hyperspectral

Evaluation of Cyber Security Based on Niagara framework

在线全文

学校读者我要写书评

暂无评论

Evaluation of Cyber Security Based on Niagara Framework

作者：马和（ALBETTAR maher）兰州理工大学

学位级别：硕士

物联网(Internet of Things)作为新一代信息技术的重要组成部分,逐渐被应用到环境监测、智能交通、工业生产、物流跟踪等领域。Tridium公司研发了Niagara物联网框架用于搭建物联网监控系统,以实现泛在网络异构设备互联互通。Niagara框... 详细信息

物联网(Internet of Things)作为新一代信息技术的重要组成部分,逐渐被应用到环境监测、智能交通、工业生产、物流跟踪等领域。Tridium公司研发了Niagara物联网框架用于搭建物联网监控系统,以实现泛在网络异构设备互联互通。Niagara框架作为一套开放的物联网平台,使用Java虚拟机作为跨操作系统和硬件平台的通用运行的环境,该框架设计兼容所有网络集成协议,也适用于能够运行Java虚拟机的嵌入式系统。该框架实现了自下而上各个功能的模块化开发和封装,并以Java库的方式开放出来,供第三方开发者调用。但是这给安全漏洞和隐患的产生提供了条件,基于Niagara框架的应用系统也将面临很多安全风险和威胁。目前,Niagara框架的研发和应用还处在起步阶段,框架本身也存在一些潜在安全漏洞,需要进一步的修复和完善工作。在2018年6月发布的新版本中,Tridium公司对Niagara AX和Niagara 4中存在的安全漏洞进行了修复工作。其中威胁级别较高的一个是路径遍历漏洞,该漏洞存在于Niagara 4 framework 4.4之前版本中。该漏洞源于程序未能充分的过滤用户提交的输入。远程攻击者可借助合法的平台管理员凭证利用该漏洞获取敏感信息。目前Tridium公司已发布升级补丁修复了该安全漏洞。随着Niagara物联网框架的版本升级和监控系统中的应用部署,会出现各种不同类型的安全漏洞,需要研发人员持续的检查和修复工作,研究该框架的安全问题也是一项有意义的工作。本文分析了针对Niagara物联网框架的典型安全威胁和攻击方式,包括通过公司信息系统去访问未经授权访问工业网络,从而对Niagara框架及其网络系统进行攻击。本文首先描述了Niagara框架的基本组成结构,在此基础上讨论了与Niagara框架有关的典型威胁。针对不同安全威胁,本文提出了各自的解决方案。本文主要涉及三种安全威胁以及解决方案。第一种是Cookie和会话ID攻击。为了避免Cookie和会话ID攻击,我们需要避免会话劫持,并确保登录页面中涉及经过身份验证的Cookie。第二种是CSRf攻击,当使用Servlet页面时会发生该种攻击。为了避免这种攻击,本文提出了向Servlet页面添加一个身份验证令牌的方案。第三种攻击是网络攻击,发生在请求权限的时候,为了避免这种攻击,需要检查Niagara框架模块上的请求权限。本文对上述三种安全威胁做了安全评估,分析了存在的Niagara框架的潜在安全漏洞,研究了针对Niagara物联网框架可能攻击因素。针对三种不同的安全漏洞,提出了解决方案,并做了安全验证实验。测试实验表明,本文提出的应对方案是有效的,可以消除潜在的安全漏洞,在一定程度上可以提高Niagara框架的安全性能。

关键词：网络安全物联网安全 Niagara框架嵌入式系统 JACE控制器

同方学位论文库评论

在线全文

同方学位论文库

学校读者我要写书评

暂无评论

内植物的材料学（上）

中华骨科杂志 2007年第3期27卷 238-240页

作者： Timothy M Wright Suzanne maher Robert f Closkey Department of Biomechanics Hospital for Special SurgeryNew York

介绍：用于矫形外科植入物的生物材料必须具有生物相容性，即在体内不引起局部或全身的不良反应。要有很好的抗侵蚀和抗化学降解性能，具有足够的机械强度以承载从骨骼传递来的较强的力；在关节置换中作为负重关节面的材料必须能够承受... 详细信息

介绍：用于矫形外科植入物的生物材料必须具有生物相容性，即在体内不引起局部或全身的不良反应。要有很好的抗侵蚀和抗化学降解性能，具有足够的机械强度以承载从骨骼传递来的较强的力；在关节置换中作为负重关节面的材料必须能够承受数千万次的循环使用；另外必须能在相对较低的成本下制造高质量的产品。

关键词：材料学内植物生物相容性外科植入物生物材料不良反应降解性能机械强度