检索结果-南通市图书馆

A Competing Risk Hazard Model for Complications of Diabetes Mellitus

Journal of Biosciences and Medicines 2014年第5期2卷 1-11页

作者： Parvin Akter Khanam Mohammed Ataharul Islam Mohammed Abu Sayeed Tanjima Begum Mohammed Golam Rabbani Subhagata Choudhury hajera mahtab Department of Applied Statistics East West University Dhaka Bangladesh Department of Community Medicine Ibrahim Medical College Dhaka Bangladesh Department of Epidemiology and Biostatistics Bangladesh Institute of Research and Rehabilitation in Diabetes Endocrine and Metabolic Disorders (BIRDEM) Dhaka Bangladesh Department of Statistics Biostatistics and Informatics University of Dhaka Dhaka Bangladesh

Diabetes mellitus is a major public health problem globally. It is the cause of serious and sometimes life-threatening complications leading to death. It is one of the most common non communicable diseases and leading cause of death in most developed countries including Bangladesh. It is associated with the increased risk of microvascular (nephropathy and retinopathy), macrovascular (cardiovascular diseases, stroke) and other mixed (cataract, pulmonary tuberculosis, foot ulcer etc.) complications. The aim of this study was to determine the risk factors related to diabetes complications and to propose competing risk models for analyzing complications of diabetes mellitus. We study 2887 diabetic patients from the BIRDEM registry record books for the period from 1984 to 1997 who have at least two follow-up visits and who are free from complications at the first visit. The data on variables such as 2-hBG, age, sex, family history of diabetes, area of residence, educational level, BMI, SBP, DBP and treatment status are obtained. Also, the time from the diagnosis of type 2 diabetes mellitus (T2DM) to the occurrence of complications was recorded. We use the competing risk hazard model and examined the potential risk factors for determining the development of such complications. This study reveals that increase in blood pressure is a potential risk factor for CHD and nephropathy in T2DM. We also found that male and illiterate patients are more affected by nephropathy. In our study, we also revealed that female and illiterate patients are also more influenced by cataract.

关键词： Family History of Diabetes Educational Level Type 2 Diabetes Mellitus Coronary Heart Disease Mean Arterial Blood Pressure

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Childhood diabetes in a Bangladeshi population

引用

Journal of Diabetes Mellitus 2013年第1期3卷 33-37页

作者： M. Abu Sayeed Mir Masudur Rhaman Nurunnahar Fayzunnessa Parvin Akter Khanam Tanjima Begum hajera mahtab Akhter Banu Community Medicine Ibrahim Medical College Dhaka Bangladesh Epidemiology and Biostatistics Bangladesh Institute of Research and Rehabilitation in Diabetes Endocrine and Metabolic Disorders Dhaka Bangladesh Epidemiology and Biostatistics Bangladesh Institute of Research and Rehabilitation in Epidemiology and Biostatistics Bangladesh Institute of Research and Rehabilitation in Diabetes Endocrine and Metabolic Disorders Dhaka Bangladesh Institute of Nutrition and Food Science University of Dhaka Dhaka Bangladesh

Backgrounds and Aims: Several epidemiological investigations revealed that the prevalence of Type 2 Diabetes Mellitus (T2DM) has been increasing in the adult population of Bangladesh. But the prevalence of diabetes among the children and adolescents in Bangladesh has not been reported. This study addressed the prevalence of diabetes among the younger people in Bangladesh. Subjects and Methods: We investigated school children of age group 10 - 18 years in rural, suburban and urban communities. Investigations included socio-demographic information, height, weight, mid-upper-arm circumference (MUAC), blood pressure (SBP, DBP) and fasting plasma glucose (FPG). We used WHO criteria (1999) for impaired fasting glucose (IFG) and diabetes mellitus (T2DM). Results: A total of 2152 students (boys/girls: 1064/1088) volunteered the study. Their mean (SD) age was 13.3 (2.0) y, BMI was 18.5 (3.1) and MUAC was 21.2 (3.4) cm. The mean (SD) of FPG was 4.6 (0.87) mmol/l. The prevalence of IFG (95% CI) was 3.4% (2.63 - 4.17) and T2DM was 1.8% (1.23 - 2.37). BMI showed no association with FPG in either sex. In assessing risk for hyperglycemia (FPG > = 5.6mmol/l), logistic regression showed [odds ratio (OR) with 95% CI] that compared with lower age (16 y) higher age had excess risk (OR 5.2, 2.92 - 9.23). Compared with the rural the urban children had higher risk (OR 14.7, 6.41 - 33.78). Higher family income was also found to have higher risk (BDT 8000: OR 2.03, 1.30 - 3.18);whereas, higher BMI and MUAC were proved to be not significant. Conclusions: The prevalence of IFG and T2DM in Bangladeshi children and adolescents appears to be high. The urban children from the higher family income are the most vulnerable for developing diabetes, obesity and hypertension. A prospective cohort including other variables like physical activities, waist-girth, insulin or macro-/micronutrients may explain which risk factors are significant for developing diabetes among children and adolescents in Bangla

关键词： Type 2 Diabetes Mellitus Impaired Fasting Glucose Family Income Geographical Area

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Enhanced adaptive nonlinear extended state observer for pure feedback systems with matched and mismatched disturbances

引用

Control Theory and Technology 2024年第2期22卷 254-268页

作者： mahtab Delpasand Mohammad Farrokhi School of Electrical Engineering Iran University of Science and TechnologyTehran16846-13114Iran Center of Excellence for Modelling and Control of Complex Systems Iran University of Science and TechnologyTehran16846-13114Iran

In this paper, an enhanced adaptive nonlinear extended state observer (EANESO) for single-input single-output pure feedback systems in the presence of external time-varying disturbances is proposed. In this paper, a nonlinear system with matched and mismatched disturbances is considered. The conventional extended state observer (ESO) can only be applied to systems that are in the form of integral chains. Moreover, this method has limitations in the face of mismatched disturbances. In the presence of time-varying disturbances, the traditional ESOs cannot estimate the disturbances accurately. To overcome this limitation, an EANESO is proposed in this paper. The main idea is to design the nonlinear ESO (NESO) to estimate the states of the system and multiple disturbances simultaneously. The observer gains are considered time-varying and adjusted with adaptation laws to improve the estimation accuracy and overcome the peaking phenomenon. Next, the proposed controller is designed based on output feedback to eliminate the effects of multiple disturbances and stabilize the closed-loop system. Subsequently, the stability analysis of the closed-loop system and convergence of the observer error are discussed. Finally, the proposed method is applied to the inverted pendulum system. The simulated results show good performance of the proposed method as compared with a recently published scheme in the related literature.

关键词： Nonlinear extended state observer Enhanced adaptive extended state observer Adaptation law Multiple-channel disturbances Inverted pendulum system Time-varying gain

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

STUDYING THE ABRASION BEHAVIOR OF RUBBERY MATERIALS WITH COMBINED DESIGN OF EXPERIMENT-ARTIFICIAL NEURAL NETWORK

引用

Chinese Journal of Polymer Science 2012年第4期30卷 520-529页

作者： Mehdi Shiva Hossein Atashi mahtab Hassanpourfard Research and Development Department ofKavir Tire Company.P.O.Box 518.Birjand Iran Department of Chemical Engineering Sistan and Baluchestan UniversityP.O.Box 98-164161ZahedanIran Departmen ofChemical Engineering Amirkabir University of TechnologyTehranlran

In this study, an application of artificial neural network （ANN） has been presented in modeling and studying the effect of compounding variables on abrasion behavior of rubber formulations. Three case studies were carried out in which the experiment data were collected according to classical response surface designs. Besides developing the ANN models, we developed response surface methodology （RSM） to confirm the ANN predictions. A simple relation was employed for determination of relative importance of each variable according to ANN models. It was shown through these case studies that ANN models delivered very good data fitting and their simulating curves could help the researchers to better understand the abrasion behavior.

关键词： Abrasion Feed forward neural networks Rubber compounding Central composite design.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Practical approach to 2-thioxo-2,3-dihydroquinazolin-4(1H)-one via dithiocarbamate–anthranilic acid reaction

引用

Chinese Chemical Letters 2017年第1期28卷 109-112页

作者： Najmedin Azizi mahtab Edrisi Department of Green Chemistry Chemistry & Chemical Engineering Research Center of Iran P.O. Box 14335-186 Tehran Iran

A practical and straightforward protocol has been developed for the preparation of 2-thioxo-2,3-dihydroquinazolin-4（1H）-one derivatives from dithiocarbamate chemistry. The method involves the reaction of anthranilic acid derivatives（2-aminobenzoic acid, 2-aminobenzamide and isatoic anhydride）with various dithiocarbamate derivatives using ethanol as solvent. The main advantages of this protocol include practical simplicity, good to high yields, and ease of product isolation, purification and cheapness of the solvent.

关键词： Dithiocarbamate Anthranilic acid 2-Thioxo-2,3-dihydroquinazolin- 4(1H)-one 2-Aminobenzoic acid 2-Aminobenzamide lsatoic anhydride

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Intelligent Petroleum Engineering

引用

Engineering 2022年第11期18卷 27-32页

作者： Mohammad Ali Mirza mahtab Ghoroori Zhangxin Chen Department of Chemical and Petroleum Engineering University of CalgaryCalgaryAB T2N 1N4Canada

Data-driven approaches and artificial intelligence(AI)algorithms are promising enough to be relied on even more than physics-based methods;their main feed is data which is the fundamental element of each *** algorithms learn from data and unveil unseen patterns out of it The petroleum industry as a realm where huge volumes of data are generated every second is of great interest to this new *** the oil and gas industry is in the transition phase to oilfield digitization,there has been an increased drive to integrate data-driven modeling and machine learning(ML)algorithms in different petroleum engineering *** has been widely used in different areas of the *** extensive studies have been devoted to exploring AI applicability in various disciplines of this industry;however,lack of two main features is *** of the research is either not practical enough to be applicable in real-field challenges or limited to a specific problem and not *** must be given to data itself and the way it is classified and *** there are sheer volumes of data coming from different disciplines,they reside in departmental silos and are not accessible by *** order to derive as much insight as possible out of data,the data needs to be stored in a centralized repository from where the data can be readily consumed by different applications.

关键词： Artificial intelligence Machine learning Intelligent reservoir engineering Text mining Intelligent geoscience Intelligent drilling engineering

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Algorithms for Handoff Minimization in Wireless Networks

引用

Journal of Computer Science & Technology 2019年第4期34卷 887-900页

作者： Mansoor Davoodi Esmaeil Delfaraz Sajjad Ghobadi mahtab Masoori Institute for Advanced Studies in Basic Sciences Zanjan 45137-66731Iran Gran Sasso Science Institute L'Aquila 67100Italy

This study focuses on the problem of handoff minimization for a set of users moving in a wireless *** problem is analyzed by considering two cases for the user's movement under access point capacity constraints:1)all users move together,and 2)each user can have their chosen path within the *** the first case,we propose an optimal competitive ratio algorithm for the ***,in the second case,having the connectivity assumption,that is,"if a user is connected to an access point so long that the received signal strength of the access point is not less than a specified threshold,the user should continue his/her connection",we prove that no approach can reduce the number of unnecessary handoffs in an offline ***,without connectivity assumption,we present an optimal deterministic algorithm with the competitive ratio of n?for this problem under online setting,where n is the number of users and?is the maximum number of access points which cover any single point in the ***,we prove that the randomized version of the algorithm achieves an expected competitive ratio of O(log△).

关键词： competitive ratio handoff minimization offline algorithm online algorithm wireless network

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Rule of 100:An inherent limitation or performance measure in oxidative coupling of methane?

引用

Journal of Natural Gas Chemistry 2012年第3期21卷 308-313页

作者： Saeed Sahebdelfar Maryam Takht Ravanchi mahtab Gharibi Marzieh Hamidzadeh Catalyst Research Group Petrochemical Research and Technology CompanyNational Petrochemical CompanyNo.27Sarv AlleyShirazi-southMollasadraP.O.Box ***TehranIran

The oxidative coupling of methane over La203/CaO type-catalyst in a fixed-bed reactor is studied under a wide range of operating conditions （973〈T〈 1103 K, 55〈 Ptotal 〈220 kPa, and 3.7〈 mcat/VTp 〈50 kg.s/m^3）. A ten-step kinetic model incorporating all main products was used to predict the behavior of the system. Methane conversions and C2 selectivities were calculated by varying methane to oxygen ratios in the feed under different operating conditions which were also compared with the rule of 100. The results show that deviation from this rule depends on the operating conditions. Within the range studied, an increase in pressure, temperature and contact time results in smaller deviation from the rule. This rule is best approximated when the catalyst operates near its optimal performance. For negative deviations, common to the most catalysts, it is found that the optimal performance should occur at methane conversion levels lower than 50%. A plot of selectivity versus conversion for high-yield reported performance data of a large variety of catalysts shows that data points concentrated roughly in 20%-50% methane conversion region, confirming the generality and prediction of modeling.

关键词： oxidative coupling of methane (OCM) La203/CaO catalyst rule of 100 methane conversion C2 yield

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Effect of loading direction on interaction of two pre-existing open and closed flaws in a rock-like brittle material

引用

Underground Space 2020年第3期5卷 242-257页

作者： mahtab Alitalesh Mahmoud Yazdani Ahmadali Fakhimi Marjan Naeimabadi School of Civil and Environmental Engineering Tarbiat Modares UniversityTehranIran Department of Mineral Engineering New Mexico TechSocorroNMUSA

Investigations of the growth,interaction,and coalescence of cracks are important because they help to provide tools for the more realistic modeling of rock masses containing low persistence discontinuities and better estimations of the strength and stiffness of a rock *** the coalescence mechanism is useful for justifying the mechanism of continental crustal deformation,evaluating the structural failure of slopes with rock bridges,and analyzing the stability of tunnels when a mode I or mix mode failure mechanism is *** evaluation of crack growth can provide valuable information about the mechanism for the formation of new geological structures,and the formation,evolution,and growth of *** paper reports the results of diametrical compression tests on rocklike disk-shaped *** specimen contained two pre-existing open or closed *** growth,interaction,and coalescence of the pre-existing flaws were investigated both physically and numerically.A hybrid bonded particle-finite element system was used in the numerical *** results of the physical and numerical studies were in good *** particular,the induced crack patterns showed close agreement in the physical and numerical *** microscope image processing was used in the physical tests to study the dislocations along the initial *** was shown that wing crack formation was responsible for the failure of the specimen when flaws were inclined with respect to the loading *** crack growth and linkage were shown to be affected by the friction between faces of the *** addition,the slip distributions at the flaws surfaces were illustrated and examined to understand the crack propagation *** effects of the flaws on the disk failure loads were assessed both numerically and experimentally as well.

关键词： Pre-existing flaws Brazilian disk Fracture mechanics Crack propagation Coalescence Bonded particle simulation

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Analgesic,antibacterial and central nervous system depressant activities of Albizia procera leaves

引用

Asian Pacific Journal of Tropical Biomedicine 2014年第4期4卷 279-284页

作者： Mahfuza Khatoon hajera Khatun Ekramul Islam Shahnaj Parvin Department of Pharmacy University of Rajshahi

Objective:To ascertain analgesic,antibacterial and central nervous system(CNS)depressant activities of ethyl acetate,dichloromethane and carbon tetrachloride fractions of methanol extract of Albizia proceru(***)***:Leaves extracts of *** were tested for analgesic activity by acetic acid induced and formalin test method in *** in vitro antibacterial activity was performed by agar well diffusion *** depressant activity was evaluated by hole cross and open field ***:All the extracts at 200 mg/kg exhibited significant(P<0.01)analgesic activity in acetic acid induced and formalin tests method in *** activity of the ethyl acetate fraction was almost same like as standard drug indomelhacin in acetic acid induced *** CNS depressant activity of the extracts at 500 mg/kg was comparable to the positive control diazepam as determined by hole cross and open field test *** extracts exhibited moderate antimicrobial activity against all the tested microorganisms(Staphylococcus aureus,Bacillus cereus,Pseudomonas aeruginosa,Esherichia coli,Shigetta *** boydii)at concentration of 0.8 mg/*** measured diameter of zone of inhibition for the extracts was within the range of 7 to 12 mm which was less than the standard kanamycin(16-24 mm).Conclusions:It is concluded that all the extracts possess potential analgesic and CNS depressants *** study also showed that different fractions of methanol extract could be potential sources of new antimicrobial agents.

关键词： Analgesic CNS depressants Antimicrobial Albizia procera leaves

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：