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Analysis of Risks in Hainan Island Typhoon Hazard Factor Based on GIS 被引量:2
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作者 ZHANG Zhong-wei ZHANG Jin-hong +2 位作者 ZHAO Zhi-zhong LIU Shao-jun XIE Rui-hong 《Meteorological and Environmental Research》 CAS 2011年第1期31-34,共4页
[Objective] The aim of this paper was to analyze the risks in the typhoon hazard factors in Hainan Island. [Method] Taking the theory and method of natural disasters evaluation as starting point and supporting point, ... [Objective] The aim of this paper was to analyze the risks in the typhoon hazard factors in Hainan Island. [Method] Taking the theory and method of natural disasters evaluation as starting point and supporting point, and selecting Hainan province as the research target, where the typhoon disaster occurred relatively serious, based on the typhoon data during 1958-2008, with happening frequency of typhoon hazard-formative factors, maximum rainfall, potentially devastating effects of typhoon winds as evaluation indexes, the typhoon disaster risk evaluation index system and evaluation model were established. And by dint of GIS technique, Hainan island typhoon disaster risk zoning of hazard-formative factors and grading were prepared. [Result] Typhoon occurred frequently in Hainan and there were no certain rules of its annual changes. The monthly changes mainly happed during July to October. The highly dangerous area of typhoon mainly distributed in east coast area. The annual daily precipitation decreased from central mountainous area to the surroundings; typhoon hided in the destructive highly risked area in east, south and west area; low disastrous area occurred in the middle area; the risks of disastrous factors weakened from east area to west area. The distribution area of each level was that low dangerous area>mild dangerous area>highly dangerous area>secondary low dangerous area>highly dangerous area. [Conclusion] The study supplied scientific reference for the government in the united organization and direction of disaster relief work. 展开更多
关键词 TYPHOON hazard-formative factors Risk assessment Hainan Island China
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The Development of Time-of-flight Mass Spectrometry( TOF-MS) and Its Applications in Screening Food Hazard Factors
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作者 Lei WANG Lixue DONG +4 位作者 Yi LI Huihui CAO Yanhua YAN Ruihuan DU Aijun LI 《Agricultural Biotechnology》 CAS 2020年第2期101-104,共4页
The time-of-flight mass spectrometry(TOF-MS),one of the mass spectrometry techniques,has been widely applied in the field of rapid screening of food hazard factors as a superior analysis technique because of its wide ... The time-of-flight mass spectrometry(TOF-MS),one of the mass spectrometry techniques,has been widely applied in the field of rapid screening of food hazard factors as a superior analysis technique because of its wide mass range,high resolution and mass measurement accuracy,high sensitivity and high analysis speed.In this paper,research progresses of TOF-MS on the detection of food additives,food contaminants and residues,illegal additives,pesticide residues,veterinary drug residues and mycotoxin were reviewed,and its probable approaching applications were prospected. 展开更多
关键词 TIME-OF-FLIGHT mass SPECTROMETRY FOOD hazard factor SCREENING Application
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Distribution Characteristics and Influencing Factors of Geological Hazards in Tibet 被引量:5
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作者 FAN Jihui WU Caiyan Cheng Genwei 《Wuhan University Journal of Natural Sciences》 EI CAS 2006年第4期806-812,共7页
Tibet is one of the areas with most serious geological hazards in China, and the distribution of disasters has obvious local charac teristics. Tibet can be classified as three parts through zoning the danger degree, t... Tibet is one of the areas with most serious geological hazards in China, and the distribution of disasters has obvious local charac teristics. Tibet can be classified as three parts through zoning the danger degree, the mountain canyon high danger zone of east and southeast Tibet, the plateau mountain lake basin and valley middle danger zone of south Tibet, and the Plateau Mountain lake basin low danger zone of south Tibet. This paper takes the debris flow, collapse, landslide as the key points to analyze the distribution characteristics of geological hazards, and analyze the factors which influence the distribution of geological hazards, such as terrain landform, formation lithology, geologic structure pattern, precipitation, earthquake, human activity and so on. finally, as a conclusion., in whole Tibet, the geological hazards are more in southeast than in northwest, more in mountainous area which in the edge of plateau and river valley than in the interior of plateau and lake basin. And most hazards distribute in the regions where human activity is stronger than in other regions, for example towns or strips along the highway. 展开更多
关键词 TIBET geological hazards distribution characteristics influencing factors
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Hazardous and Harmful Factors on Construction Sites and Their Prevention
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作者 ZHENG Huanqiang ZHANG Zaiwang RONG Kun 《Journal of Landscape Research》 2019年第1期20-23,28,共5页
In this paper, the status quo of safety production on construction sites and the hazardous and harmful factors in the construction process were analyzed, and corresponding suggestions were proposed to make up for the ... In this paper, the status quo of safety production on construction sites and the hazardous and harmful factors in the construction process were analyzed, and corresponding suggestions were proposed to make up for the shortcomings of the safety production assurance system standards on construction sites. 展开更多
关键词 CONSTRUCTION SITE Safety PRODUCTION MANAGEMENT Identification of hazardous and harmful factorS
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Impact Factors on Fracturing Results of Coal Seams and Appropriate Countermeasures
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作者 X. Wang Y.H. Ding Y. Xu Y.Y. Duan 《Journal of Energy and Power Engineering》 2010年第6期16-26,共11页
Hydraulic fracturing is one of the efficient means for the abundant low-permeability CBM (coal-bed methane) reserves in China, however, due to the unique features of coal seams (i.e., low temperature, strong adsorp... Hydraulic fracturing is one of the efficient means for the abundant low-permeability CBM (coal-bed methane) reserves in China, however, due to the unique features of coal seams (i.e., low temperature, strong adsorption and abnormal development of natural fracture systems) as compared with the conventional reservoirs, the fractures propagate is difficult and the risk of damage to coal seam itself and the hydraulic fractures would be extremely high in the course of fracturing. As a result, losses would be suffered on the post-frac production of CBM wells.With the mean of numerical simulation, in this paper, the main factors have impact on the post-frac results as well as the extent to which the impact is brought were researched, and the technical solutions for the improvement of the fracturing performance was put forwards. 展开更多
关键词 Coal-seam fracturing hazard factors yield loss rate technical solutions.
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Measuring Social Vulnerability to Natural Hazards in Beijing-Tianjin-Hebei Region,China 被引量:2
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作者 HUANG Jianyi SU Fei ZHANG Pingyu 《Chinese Geographical Science》 SCIE CSCD 2015年第4期472-485,共14页
Social vulnerability in this study represents the differences between the capacity to cope with natural hazards and disaster losses suffered within and between places.The assessment of social vulnerability has been re... Social vulnerability in this study represents the differences between the capacity to cope with natural hazards and disaster losses suffered within and between places.The assessment of social vulnerability has been recognized as a critical step in understanding natural hazard risks and enhancing effective response capabilities.This article presents an initial study of the social vulnerability of the Beijing-Tianjin-Hebei(B-T-H) Region in China.The goal is to replicate and test the applicability of the United States Social Vulnerability Index(So VI) method in a Chinese cultural context.Thirty-nine variables adapted from the So VI were collected in relation to two aspects:socioeconomic vulnerability and built environment vulnerability.Using factor analysis,seven factors were extracted from the variable set:the structure of social development,the level of economic and government financial strength,social justice and poverty,family structure,the intensity of space development,the status of residential housing and transportation,and building structure.Factor scores were summed to get the final So VI scores and the most and least vulnerable units were identified and mapped.The highest social vulnerability is concentrated in the northwest of the study area.The least socially vulnerable areas are mainly distributed in the Beijing,Tianjin and Shijiazhuang core urban peripheral and central city areas of the prefecture-level cities.The results show that this method is a useful tool for revealing places that have a high level of vulnerability,in other words,areas which are more likely to face significant challenges in coping with a large-scale event.These findings could provide a scientific basis for policy making and the implementation of disaster prevention and mitigation in China. 展开更多
关键词 natural hazards social vulnerability factor analysis Beijing-Tianjin-Hebei Region
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Bridge pier failure probabilities under combined hazard effects of scour, truck and earthquake. Part Ⅰ: occurrence probabilities 被引量:6
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作者 Zach Liang George C. Lee 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2013年第2期229-240,共12页
In many regions of the world, a bridge will experience multiple extreme hazards during its expected service life. The current American Association of State Highway and Transportation Officials (AASHTO) load and resi... In many regions of the world, a bridge will experience multiple extreme hazards during its expected service life. The current American Association of State Highway and Transportation Officials (AASHTO) load and resistance factor design (LRFD) specifications are formulated based on failure probabilities, which are fully calibrated for dead load and nonextreme live loads. Design against earthquake loads is established separately. Design against scour effect is also formulated separately by using the concept of capacity reduction (or increased scour depth). Furthermore, scour effect cannot be linked directly to an LRFD limit state equation, because the latter is formulated using force-based analysis. This paper (in two parts) presents a probability-based procedure to estimate the combined hazard effects on bridges due to truck, earthquake and scour, by treating the effect of scour as an equivalent load effect so that it can be included in reliability-based bridge failure calculations. In Part I of this series, the general principle of treating the scour depth as an equivalent load effect is presented. The individual and combined partial failure probabilities due to truck, earthquake and scour effects are described. To explain the method of including non-force-based natural hazards effects, two types of common scour failures are considered. In Part 11, the corresponding bridge failure probability, the occurrence of scour as well as simultaneously having both truck load and equivalent scour load are quantitatively discussed. 展开更多
关键词 multi-hazards load and resistance factor design bridge scour
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Bridge pier failure probabilities under combined hazard effects of scour, truck and earthquake. Part Ⅱ: failure probabilities 被引量:3
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作者 Zach Liang George C. Lee 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2013年第2期241-250,共10页
In many regions of the world, a bridge will experience multiple extreme hazards during its expected service life. The current American Association of State Highway and Transportation Officials (AASHTO) load and resi... In many regions of the world, a bridge will experience multiple extreme hazards during its expected service life. The current American Association of State Highway and Transportation Officials (AASHTO) load and resistance factor design (LRFD) specifications are formulated based on failure probabilities, which are fully calibrated for dead load and non-extreme live loads. Design against earthquake load effect is established separately. Design against scour effect is also formulated separately by using the concept of capacity reduction (or increased scour depth). Furthermore, scour effect cannot be linked directly to an LRFD limit state equation because the latter is formulated using force-based analysis. This paper (in two parts) presents a probability-based procedure to estimate the combined hazard effects on bridges due to truck, earthquake and scour, by treating the effect of scour as an equivalent load effect so that it can be included in reliability-based failure calculations. In Part I of this series, the general principle for treating the scour depth as an equivalent load effect is presented. In Part II, the corresponding bridge failure probability, the occurrence of scour as well as simultaneously having both truck load and equivalent scour load effect are quantitatively discussed. The key formulae of the conditional partial failure probabilities and the necessary conditions are established. In order to illustrate the methodology, an example of dead, truck, earthquake and scour effects on a simple bridge pile foundation is represented. 展开更多
关键词 multi-hazards load and resistance factor design bridge scour
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Landslide Hazard and Risk Assessment on the Northern Slope of Mt. Changbai, China 被引量:3
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作者 LIU Zhenghua ZHANG Yanbin +1 位作者 Yoshiharu ISHIKAWA Hiroyuki NAKAMURA 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2008年第1期214-224,共11页
Landslide hazard and risk assessment on the northern slope of Mt. Changbai, a well-known tourist attraction near the North Korean-Chinese border, are assessed. This study is divided into two parts, namely, landslide h... Landslide hazard and risk assessment on the northern slope of Mt. Changbai, a well-known tourist attraction near the North Korean-Chinese border, are assessed. This study is divided into two parts, namely, landslide hazard zonation and risk assessment. The 1992 Anbalagan and Singh method of landslide hazard zonation (LHZ) was modified and used in this area. In this way, an Associative Analysis Method was used in representative areas to get a measure for controlling factors (slope gradient, relative relief, vegetation, geology, discontinuity development, weak layer thickness and ground water). For the membership degree of factor to slope failure, the middle range of limited values was used to calculate LHZ. Based on an estimation of the potential damage from slope failure, a reasonable risk assessment map was obtained using the relationship of potential damage and probable hazard to aid future planning and prediction and to avert loss of life. 展开更多
关键词 Landslide hazard Zonation (LHZ) controlling factor Associative Analysis Method membership degree risk assessment TOURISM China
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A Cox Proportional Hazard Model Approach to Age at First Sexual Intercourse in Nigeria 被引量:1
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作者 Chukwudi Paul Obite Desmond Chekwube Bartholomew +2 位作者 Iheoma Blessing Duru Joan Ismaila-Cosmos Chidiebere Chukwuemeka 《Open Journal of Statistics》 2020年第2期252-260,共9页
Early age at first sexual intercourse comes with many negative sexual outcomes namely: having unprotected sex on first sexual intercourse, condom misuse, high rate of sexually transmitted infections (STIs), teenage pr... Early age at first sexual intercourse comes with many negative sexual outcomes namely: having unprotected sex on first sexual intercourse, condom misuse, high rate of sexually transmitted infections (STIs), teenage pregnancy, increased number of sexual partners, etc. In this paper, we considered some socio-demographic and cultural factors and their relationship with age at first sexual intercourse so as to reduce the numerous negative sexual outcomes of early age at first sexual intercourse using the 2018 Nigerian Demographic and Health Survey data. The analysis was made using the Cox proportional hazard model and the Kaplan-Meier plot. The result shows that some respondents started having their first sexual intercourse at the age of 8 years and about 54.4% of the respondents had their first sexual intercourse before age 17 years. The median age of first sexual intercourse is 16 years which implies that about 50% of the respondents had their first sexual intercourse on or before their 16th birthday. Education, religion, region and residence significantly affects the age of first sexual intercourse while circumcision has no significant effect. 展开更多
关键词 Sexual INTERCOURSE SOCIO-DEMOGRAPHIC and CULTURAL factors hazard Rate COX Proportional hazard Model
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Towards establishing practical multi-hazard bridge design limit states 被引量:3
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作者 Zach Liang George C.Lee 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2013年第3期333-340,共8页
In the U.S., the current Load and Resistance Factor Design (LRFD) Specifications for highway bridges is a reliability-based formulation that considers failure probabilities of bridge components due to the actions of... In the U.S., the current Load and Resistance Factor Design (LRFD) Specifications for highway bridges is a reliability-based formulation that considers failure probabilities of bridge components due to the actions of typical dead load and frequent vehicular loads. Various extreme load effects, such as earthquake and vessel collision, are on the same reliability-based platform. Since these extreme loads are time variables, combining them with not considered frequent. non- extreme loads is a significant challenge. The number of design limit state equations based on these failure probabilities can be unrealistically large and unnecessary from the view point of practical applications. Based on the opinion of AASHTO State Bridge Engineers, many load combinations are insignificant in their states. This paper describes the formulation of a criterion to include only the necessary load combinations to establish the design limit states. This criterion is established by examining the total failure probabilities for all possible time-invariant and time varying load combinations and breaking them down into partial terms. Then, important load combinations can be readily determined quantitatively, 展开更多
关键词 multi-hazards load and resistance factor design re.liability based bridge design specifications design limit state equations
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基于风雨综合指数的安徽省台风灾害房屋风险评估方法 被引量:1
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作者 宋阿伟 田红 +6 位作者 王胜 刘前 谢五三 唐为安 戴娟 丁小俊 吴蓉 《暴雨灾害》 2024年第3期363-370,共8页
台风致灾因子具有多重性,相对于其他灾种其风险评估更加复杂。采用安徽省81个国家气象站及1035个区域气象站台风过程逐日降水量、最大风速资料,构建台风风雨综合指数;利用台风风雨综合指数及孕灾环境影响系数,开展台风致灾危险性评估;... 台风致灾因子具有多重性,相对于其他灾种其风险评估更加复杂。采用安徽省81个国家气象站及1035个区域气象站台风过程逐日降水量、最大风速资料,构建台风风雨综合指数;利用台风风雨综合指数及孕灾环境影响系数,开展台风致灾危险性评估;基于自然灾害风险系统理论,综合致灾危险性、承灾体暴露度和脆弱性信息,评估安徽省台风灾害房屋风险。结果表明:影响安徽省台风年均个数为1.9个,持续天数以2~4 d居多;台风降水南部多于北部、山区多于平原。台风致灾高危险区位于皖南山区和大别山区,较高危险区位于江淮之间东部,低危险区位于沿淮淮北大部及江淮之间西北部。台风灾害房屋高及较高风险区主要分布在大别山区、江淮之间东部及皖南山区,这些区域海拔总体较高,台风过境易引发山洪地质灾害,加之房屋脆弱性较高,房屋倒塌及损毁风险高;中等风险区位于沿淮至江淮之间、江南部分地区,呈零星分布;较低和低风险区位于淮河以北中西部、沿江部分地区及城市主城区。利用全省各县区台风造成的房屋倒损数据,从空间一致性及散点相关对区划结果进行验证得到,区划结果与灾损具有高度的空间一致性,二者散点相关通过0.01的显著性水平检验,安徽省台风灾害房屋风险区划结果与实际情况基本吻合。 展开更多
关键词 台风灾害 风险评估 致灾因子 风雨综合指数 承灾体 栅格
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考虑时间变化的洪涝灾害损失评估 被引量:2
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作者 王浩 赵铜铁钢 +3 位作者 田雨 陈泽聪 郑炎辉 陈晓宏 《水利学报》 EI CSCD 北大核心 2024年第2期127-136,共10页
洪涝灾害是对我国影响最大的自然灾害之一。聚焦灾害损失评估问题,本文构建了考虑时间变化的洪涝灾害损失函数。一方面,表征灾害损失随着致灾因子强度先递增、而后增幅趋缓的静态S型曲线关系;另一方面,通过量级、形状和位置三个参数综... 洪涝灾害是对我国影响最大的自然灾害之一。聚焦灾害损失评估问题,本文构建了考虑时间变化的洪涝灾害损失函数。一方面,表征灾害损失随着致灾因子强度先递增、而后增幅趋缓的静态S型曲线关系;另一方面,通过量级、形状和位置三个参数综合考虑灾害损失随时间的动态变化情况。基于《中国水旱灾害防御公报》提供的受灾人口、直接经济损失数据,对于各省级行政区2006—2021年洪涝灾害损失进行评估分析。结果表明:通过拟合洪涝灾害损失函数,洪涝灾害损失关于致灾因子强度和时间的三维空间散点图可有效地拓展成为连续的三维空间曲面及二维空间热力图。各省级行政区受灾人口整体上呈现出逐年下降的特征,但随致灾因子强度的增加而趋于增加。各省级行政区直接经济损失则表现出明显的差异,随时间呈现出大幅下降、缓慢下降和略有增加等不同特征。考虑时间变化的洪涝灾害损失函数是变化环境下灾害评估的有效工具,可为区域洪涝灾情评估提供借鉴和参考。 展开更多
关键词 洪涝灾害 致灾因子 损失函数 受灾人口 直接经济损失 非一致性
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Risk Analysis of Chemical Hazards Based on the Case of EU Children’s Products Recalled and Study on the Reasonable Limitation of Harmful Element in Toys
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作者 Weiqiang Huo Han Fang +5 位作者 Xiaoting Chen Shan Zhao Zhiyong Ding Lin Zhe Yang Chen Jin Luo 《Journal of Biomedical Science and Engineering》 2022年第1期1-5,共5页
The trade situation about China’s export of toy products to the EU was introduced. The recall characteristics of China’s toy products by the EU “Safety Gate” in terms of recall frequency, notified countries, taken... The trade situation about China’s export of toy products to the EU was introduced. The recall characteristics of China’s toy products by the EU “Safety Gate” in terms of recall frequency, notified countries, taken measures, and reasons for recall were analyzed in this paper, and the risk factors of human health of unqualified products in terms of chemical hazards were studied in this paper. It is found that phthalate, boron, plumbum and cadmium were the main factors. Assessment of risk for boron in toys was conducted. It is suggested to limit the boron element in Slime: the limit of migration of boron in Slime toys for 3- to 6-year-old children shall be less than 704 mg/kg, and the limitation of migration of boron in Slime toys for 7- to 12-year-old children shall be less than 1268 mg/kg. 展开更多
关键词 Products for Children Chemical hazard Risk factors Limitation of Boron
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Factor analysis of earthquake-induced geological disasters of the M7.0 Lushan earthquake in China 被引量:3
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作者 Li Xue Liu Xiaoli +3 位作者 Li Jinggang Wang Qiuliang Liao Wulin Zhang Lifen 《Geodesy and Geodynamics》 2013年第2期22-29,共8页
The seismic intensities, lithologic characteristics and terrain features from a 3000 km2-region near the epicenter of the Lushan earthquake are used to analyze earthquake-induced geological disaster. The preliminary r... The seismic intensities, lithologic characteristics and terrain features from a 3000 km2-region near the epicenter of the Lushan earthquake are used to analyze earthquake-induced geological disaster. The preliminary results indicate that secondary effects of the earthquake will affect specific areas, including those with glutenite and carbonate bedrock, a seismic intensity of IX, slopes between 40° and 50°, elevations of less than 2500 m, slope change rates between 20° and 30°, slope curvatures from - 1 to -0.5 and 0. 5 to 1, and relief between 50 and 100 m. Regions with susceptibility indices greater than 0.71 are prone to landslides and collapses. The secondary features are mainly distributed on both sides of the ridges that extend from Baosheng to Shuangshi and from Baosheng to Longxing. Other features are scattered on both sides of the ridges that extend from Qishuping to Baosheng and from Masangping to Lingguan. The distribution of the earthquake-related features trends in the NE direction, and the area that was most affected by the Lushan earthquake covers approximately 52.4 km^2. 展开更多
关键词 Lushan earthquake earthquake-induced geological disaster factor analysis susceptibility index hazard distribution
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糖尿病肾脏疾病预后影响因素的COX比例风险回归模型分析 被引量:2
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作者 陈占科 陈凯丽 +5 位作者 应春苗 冯素香 崔伟锋 徐江雁 袁婷婷 李耀洋 《中华中医药学刊》 CAS 北大核心 2024年第2期28-33,共6页
目的基于COX比例风险回归模型分析糖尿病肾脏疾病(diabetic kidney disease,DKD)预后的影响因素,为临床早期评估和防治DKD提供科学的依据。方法收集多中心(河南中医药大学第一附属医院、河南中医药大学第三附属医院、河南省中医院及郑... 目的基于COX比例风险回归模型分析糖尿病肾脏疾病(diabetic kidney disease,DKD)预后的影响因素,为临床早期评估和防治DKD提供科学的依据。方法收集多中心(河南中医药大学第一附属医院、河南中医药大学第三附属医院、河南省中医院及郑州市人民医院)2010—2021年就诊治疗的DKD患者资料,包括一般资料、实验室指标、中医辨证分型及中医药治疗,以肾小球滤过率(eGFR)下降≥50%、血肌酐(Scr)翻倍、DKD 5期、死亡为结局指标,随访其发生时间及情况,利用COX比例风险回归模型分析筛选DKD预后影响因素。结果本研究最终纳入1947例患者,随访时间为4.65(4.557~4.746)年,发生复合终点事件305例(15.67%)。单因素COX回归分析结果表明,不同年龄、DKD病程≥4年、饮酒史、吸烟史、高血压、冠心病、脑血管病、糖尿病足、糖尿病眼病、糖化血红蛋白(HbA1c)、血尿酸(SUA)、Scr、24 h尿蛋白定量(24 h-UTP)、eGFR、湿热血瘀证、脾肾气虚兼湿聚血瘀证、脾肾阳虚兼血瘀证、中药熏洗、服用中药患者DKD预后情况比较,差异有统计学意义(P<0.05)。多因素COX回归分析结果表明,年龄[HR(95%CI)=2.52(1.92,3.30)]、DKD病程[HR(95%CI)=1.62(1.09,2.42)]、吸烟史[HR(95%CI)=1.61(1.13,2.29)]、饮酒史[HR(95%CI)=1.41(1.01,1.95)]、脑血管病[HR(95%CI)=1.33(1.01,1.75)]、糖尿病眼病[HR(95%CI)=1.43(1.13,1.82)]、SUA[HR(95%CI)=1.72(1.26,2.33)]、24 h-UTP[HR(95%CI)=1.48(1.14,1.91)]、脾肾气虚兼湿聚血瘀证[HR(95%CI)=2.22(1.44,3.43)]与DKD发生终点事件的风险关系密切(P<0.05),服用中药[HR(95%CI)=2.57(2.00,3.31)]能够减少终点事件的发生(P<0.05)。结论年龄、DKD病程、吸烟史、饮酒史、脑血管病、糖尿病眼病、SUA、24 h-UTP、脾肾气虚兼湿聚血瘀证是影响DKD患者预后的危险因素,而服用中药治疗为其保护因素。 展开更多
关键词 糖尿病肾脏疾病 预后 影响因素 COX比例风险回归模型
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基于系统动力学的危险化学品运输风险因素研究 被引量:1
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作者 刘紫玉 乾文慧 陈军霞 《河北工业科技》 CAS 2024年第2期124-132,共9页
为了降低危化品运输事故频次,规避危化品在运输过程中的风险,基于系统动力学模型,从人、机、环、管4个维度构建危化品运输风险因素指标体系,使用AHP法对指标权重进行赋值,结合风险因素间的因果关系构建参数方程,利用Vensim软件仿真模拟... 为了降低危化品运输事故频次,规避危化品在运输过程中的风险,基于系统动力学模型,从人、机、环、管4个维度构建危化品运输风险因素指标体系,使用AHP法对指标权重进行赋值,结合风险因素间的因果关系构建参数方程,利用Vensim软件仿真模拟危化品运输风险水平的变化趋势,确定单因素变量值和人、机、环、管风险子系统权重的变化对危化品运输风险系统动力学模型的影响程度。结果表明:安全意识薄弱、设备故障等风险因素的变动以及人、机、环、管风险子系统的权重变动都会影响危化品运输风险水平,人、机、环、管4个子系统对危化品运输风险的影响程度从高到低依次是人、管、环、机。研究结果可为降低危化品运输过程中的风险和制定危化品运输事故预防策略提供一定参考。 展开更多
关键词 物流系统管理 危险化学品 运输风险 风险因素 系统动力学
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Exploring the Impact of Factors Affecting the Lifespan of HIVs/AIDS Patient’s Survival: An Investigation Using Advanced Statistical Techniques
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作者 Christiana I. Ezeilo Edith U. Umeh +1 位作者 Daniel C. Osuagwu Chrisogonus K. Onyekwere 《Open Journal of Statistics》 2023年第4期594-618,共25页
This study investigates the impact of various factors on the lifespan and diagnostic time of HIV/AIDS patients using advanced statistical techniques. The Power Chris-Jerry (PCJ) distribution is applied to model CD4 co... This study investigates the impact of various factors on the lifespan and diagnostic time of HIV/AIDS patients using advanced statistical techniques. The Power Chris-Jerry (PCJ) distribution is applied to model CD4 counts of patients, and the goodness-of-fit test confirms a strong fit with a p-value of 0.6196. The PCJ distribution is found to be the best fit based on information criteria (AIC and BIC) with the smallest negative log-likelihood, AIC, and BIC values. The study uses datasets from St. Luke hospital Uyo, Nigeria, containing HIV/AIDS diagnosis date, age, CD4 count, gender, and opportunistic infection dates. Multiple linear regression is employed to analyze the relationship between these variables and HIV/AIDS diagnostic time. The results indicate that age, CD4 count, and opportunistic infection significantly impact the diagnostic time, while gender shows a nonsignificant relationship. The F-test confirms the model's overall significance, indicating the factors are good predictors of HIV/AIDS diagnostic time. The R-squared value of approximately 72% suggests that administering antiretroviral therapy (ART) can improve diagnostic time by suppressing the virus and protecting the immune system. Cox proportional hazard modeling is used to examine the effects of predictor variables on patient survival time. Age and CD4 count are not significant factors in the hazard of HIV/AIDS diagnostic time, while opportunistic infection is a significant predictor with a decreasing effect on the hazard rate. Gender shows a strong but nonsignificant relationship with decreased risk of death. To address the violation of the assumption of proportional hazard, the study employs an assumption-free alternative, Aalen’s model. In the Aalen model, all predictor variables except age and gender are statistically significant in relation to HIV/AIDS diagnostic time. The findings provide valuable insights into the factors influencing diagnostic time and survival of HIV/AIDS patients, which can inform interventions aimed at reducing transmission and improving early diagnosis and treatment. The Power Chris-Jerry distribution proves to be a suitable fit for modeling CD4 counts, while multiple linear regression and survival analysis techniques provide insights into the relationships between predictor variables and diagnostic time. These results contribute to the understanding of HIV/AIDS patient outcomes and can guide public health interventions to enhance early detection, treatment, and care. 展开更多
关键词 Chris-Jerry Distribution Power Chris-Jerry Distribution Cox Proportional hazard Aalen’s Model factors Affecting HIV/AIDS Patients CD4 Counts of HIV/AIDS Patients
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Exploring the Impact of Factors Affecting the Lifespan of HIVs/AIDS Patient’s Survival: An Investigation Using Advanced Statistical Techniques
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作者 Christiana I. Ezeilo Edith U. Umeh +1 位作者 Daniel C. Osuagwu Chrisogonus K. Onyekwere 《Open Journal of Endocrine and Metabolic Diseases》 2023年第4期594-618,共25页
This study investigates the impact of various factors on the lifespan and diagnostic time of HIV/AIDS patients using advanced statistical techniques. The Power Chris-Jerry (PCJ) distribution is applied to model CD4 co... This study investigates the impact of various factors on the lifespan and diagnostic time of HIV/AIDS patients using advanced statistical techniques. The Power Chris-Jerry (PCJ) distribution is applied to model CD4 counts of patients, and the goodness-of-fit test confirms a strong fit with a p-value of 0.6196. The PCJ distribution is found to be the best fit based on information criteria (AIC and BIC) with the smallest negative log-likelihood, AIC, and BIC values. The study uses datasets from St. Luke hospital Uyo, Nigeria, containing HIV/AIDS diagnosis date, age, CD4 count, gender, and opportunistic infection dates. Multiple linear regression is employed to analyze the relationship between these variables and HIV/AIDS diagnostic time. The results indicate that age, CD4 count, and opportunistic infection significantly impact the diagnostic time, while gender shows a nonsignificant relationship. The F-test confirms the model's overall significance, indicating the factors are good predictors of HIV/AIDS diagnostic time. The R-squared value of approximately 72% suggests that administering antiretroviral therapy (ART) can improve diagnostic time by suppressing the virus and protecting the immune system. Cox proportional hazard modeling is used to examine the effects of predictor variables on patient survival time. Age and CD4 count are not significant factors in the hazard of HIV/AIDS diagnostic time, while opportunistic infection is a significant predictor with a decreasing effect on the hazard rate. Gender shows a strong but nonsignificant relationship with decreased risk of death. To address the violation of the assumption of proportional hazard, the study employs an assumption-free alternative, Aalen’s model. In the Aalen model, all predictor variables except age and gender are statistically significant in relation to HIV/AIDS diagnostic time. The findings provide valuable insights into the factors influencing diagnostic time and survival of HIV/AIDS patients, which can inform interventions aimed at reducing transmission and improving early diagnosis and treatment. The Power Chris-Jerry distribution proves to be a suitable fit for modeling CD4 counts, while multiple linear regression and survival analysis techniques provide insights into the relationships between predictor variables and diagnostic time. These results contribute to the understanding of HIV/AIDS patient outcomes and can guide public health interventions to enhance early detection, treatment, and care. 展开更多
关键词 Chris-Jerry Distribution Power Chris-Jerry Distribution Cox Proportional hazard Aalen’s Model factors Affecting HIV/AIDS Patients CD4 Counts of HIV/AIDS Patients
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激素治疗慢性肾脏病进展高风险IgA肾病患者的预后分析——一项回顾性研究
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作者 高歌 张鑫越 +3 位作者 冯玉华 窦婧予 吴雪莹 程根阳 《中国全科医学》 北大核心 2024年第6期692-698,共7页
背景IgA肾病(IgAN)是世界范围内常见的原发性肾小球肾炎之一,目前糖皮质激素是否能改善慢性肾脏病(CKD)进展高风险IgAN患者肾脏预后尚无明确结论。目的本研究旨在探讨激素治疗对CKD进展高风险IgAN患者的治疗反应及肾脏预后的影响。方法... 背景IgA肾病(IgAN)是世界范围内常见的原发性肾小球肾炎之一,目前糖皮质激素是否能改善慢性肾脏病(CKD)进展高风险IgAN患者肾脏预后尚无明确结论。目的本研究旨在探讨激素治疗对CKD进展高风险IgAN患者的治疗反应及肾脏预后的影响。方法回顾性纳入2017年1月—2021年10月于郑州大学第一附属医院就诊的CKD进展高风险IgAN患者。根据是否进行激素治疗将患者分为激素治疗组和支持治疗组,采用倾向匹配法按照性别、年龄、24 h尿蛋白定量、估算肾小球滤过率(eGFR)对患者进行1∶1匹配筛选病例,收集患者的临床及病理资料,记录患者治疗1年内疾病缓解情况及不良反应发生情况。以开始支持治疗的日期作为随访起点,随访至2022-10-31,主要终点事件定义为:进展为终末期肾脏病(ESRD)或接受透析治疗。复合终点事件定义为:eGFR较基线持续下降超过30%或进入ESRD或接受透析或患者死亡;运用Kaplan-Meier法绘制生存曲线,并采用Log-rank检验比较两组患者主要/复合终点事件累积发生率的差异。运用Cox比例风险回归分析探究影响CKD进展高风险IgAN患者预后的可能因素。结果共有236例原发性IgAN患者符合纳入标准,经过1∶1匹配,激素治疗组97例与支持治疗组97患者匹配成功,两组基线数据匹配均衡。激素治疗组患者完全缓解率、部分缓解率均高于支持治疗组(χ^(2)=6.171,P=0.013;χ^(2)=3.973,P=0.046)。中位随访时间为18.00(9.75,28.00)个月。Kaplan-Meier生存分析结果显示,激素治疗组的主要终点事件累积发生率低于支持治疗组(χ^(2)=4.495,P=0.034);激素治疗组的复合终点事件累积发生率低于支持治疗组(χ^(2)=4.419,P=0.036)。符合纳入标准的236例患者中有177例中等量蛋白尿患者,采用倾向匹配法按照性别、年龄、24 h尿蛋白定量、eGFR对激素治疗和支持治疗的177例患者进行1∶1匹配后,激素治疗中等量蛋白尿者和支持治疗中等量蛋白尿者各有76例患者匹配成功。Kaplan-Meier生存曲线结果显示,激素治疗中等量蛋白尿者的主要终点事件累积发生率低于支持治疗中等量蛋白尿者(χ^(2)=4.127,P=0.042);激素治疗中等量蛋白尿者的复合终点事件累积发生率低于支持治疗中等量蛋白尿者(χ^(2)=4.934,P=0.026)。多因素Cox比例风险回归分析结果显示血红蛋白(HR=0.982)、血肌酐(HR=1.019)、eGFR(HR=1.020)、24 h尿蛋白定量(HR=1.205)是影响CKD进展高风险IgAN患者发生主要终点事件的影响因素(P<0.05)。激素治疗组感染发生率高于支持治疗组(P<0.05)。结论在CKD进展高风险IgAN肾病患者中,与单纯支持治疗相比,激素治疗可以显著提升肾脏缓解率,降低肾功能下降、肾衰竭风;但仍需警惕其不良反应的发生。 展开更多
关键词 肾小球肾炎 IgA 糖皮质激素类 蛋白尿 预后 危险因素 比例风险度模型
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