期刊文献+
共找到192,474篇文章
< 1 2 250 >
每页显示 20 50 100
Oxidation Kinetics of Aluminum Powders in a Gas Fluidized Bed Reactor in the Potential Application of Surge Arresting Materials
1
作者 Hong Shih 《Materials Sciences and Applications》 2019年第3期253-292,共40页
In this technical paper, the oxidation mechanism and kinetics of aluminum powders are discussed in great details. The potential applications of spherical aluminum powders after oxidation to be part of the surging arre... In this technical paper, the oxidation mechanism and kinetics of aluminum powders are discussed in great details. The potential applications of spherical aluminum powders after oxidation to be part of the surging arresting materials are discussed. Theoretical calculations of oxidation of spherical aluminum powders in a typical gas fluidization bed are demonstrated. Computer software written by the author is used to carry out the basic calculations of important parameters of a gas fluidization bed at different temperatures. A mathematical model of the dynamic system in a gas fluidization bed is developed and the analytical solution is obtained. The mathematical model can be used to estimate aluminum oxide thickness at a defined temperature. The mathematical model created in this study is evaluated and confirmed consistently with the experimental results on a gas fluidization bed. Detail technical discussion of the oxidation mechanism of aluminum is carried out. The mathematical deviations of the mathematical modeling have demonstrated in great details. This mathematical model developed in this study and validated with experimental results can bring a great value for the quantitative analysis of a gas fluidization bed in general from a theoretical point of view. It can be applied for the oxidation not only for aluminum spherical powders, but also for other spherical metal powders. The mathematical model developed can further enhance the applications of gas fluidization technology. In addition to the development of mathematical modeling of a gas fluidization bed reactor, the formation of oxide film through diffusion on both planar and spherical aluminum surfaces is analyzed through a thorough mathematical deviation using diffusion theory and Laplace transformation. The dominant defects and their impact to oxidation of aluminum are also discussed in detail. The well-controlled oxidation film on spherical metal powders such as aluminum and other metal spherical powders can potentially become an important part of switch devices of surge arresting materials, in general. 展开更多
关键词 Aluminum Spherical Power GAS FLUIDIZATION Bed Oxidation Mechanism Oxide Growth Rate Gibbs Free Energy Ellingham Diagram Mathematical Modeling Dynamic System Plasma DIFFUSION DIFFUSION Coefficient Crystallographic Defect Vacancy Pressure Temperature Flow Laplace Transform Equation Boundary Condition Ficks Second Law Software Experimental Theoretical SURGE ARRESTING MATERIALS Analytical Solution
下载PDF
The assessment of time dependent flow of Williamson fluid with radiative blood flow against a wedge 被引量:1
2
作者 K.Subbarayudu S.Suneetha P.Bala Anki Reddy 《Propulsion and Power Research》 SCIE 2020年第1期87-99,共13页
The present pagination reports both Brownian diffusion and thermophoresis aspects subject to magneto hydrodynamic Williamson fluid model.Assuming the flow is unsteady and blood is treated as Williamson fluid over a we... The present pagination reports both Brownian diffusion and thermophoresis aspects subject to magneto hydrodynamic Williamson fluid model.Assuming the flow is unsteady and blood is treated as Williamson fluid over a wedge with radiation.The governing equations are transformed into ordinary differential equations by using similarity variables.The analytical solutions of the transformed governing equations are obtained by using the RK 4th order method along with shooting technique solver.The effects of various physical parameters such as Hartmann number,local Weissenberg number,radiation parameter,unsteadiness parameter,Prandtl number,Lewis number,Brownian diffusion,thermophoresis,wedge angle parameter,moving wedge parameter,on velocity,temperature,concentration,skin friction,heat transfer rate and mass transfer rate have been discussed in detail.The velocity and temperature profile deprives for larger We and an opposite trend is observed for concentration.The radiation parameter is propositional to temperature and a counter behaviour is observed for Pr. 展开更多
关键词 The present pagination reports both Brownian diffusion and thermophoresis aspects subject to magneto hydrodynamic WILLIAMSON fluid model. Assuming the flow IS unsteady and blood IS treated as WILLIAMSON fluid over a WEDGE with radiation. The governing EQUATIONS are transformed into ordinary differential EQUATIONS by using similarity variables. The analytical solutions of the transformed governing EQUATIONS are obtained by using the RK 4th order method along with shooting technique solver. The effects of various physical parameters such as Hartmann NUMBER local Weissenberg NUMBER radiation PARAMETER unsteadiness PARAMETER Prandtl NUMBER Lewis NUMBER Brownian diffusion thermophoresis WEDGE angle PARAMETER moving WEDGE PARAMETER on velocity temperature concentration skin friction heat transfer rate and mass transfer rate have been discussed in detail. The velocity and temperature profile deprives for larger We and an opposite trend IS observed for concentration. The radiation PARAMETER IS propositional to temperature and a counter behaviour IS observed for Pr.
原文传递
Characteristics of Patients with Decreased Cognitive Function Undergoing Treatment for Acute Exacerbation of Chronic Heart Failure—Basic Survey for Standardization of Nursing to Prevent Discontinuation of Treatment 被引量:5
3
作者 Haruka Otsu Toshiko Inoguchi +3 位作者 Michiko Moriyama Shigeko Takayama Yoko Watanabe Masayo Kume 《Health》 2018年第5期667-690,共24页
The purpose of this study is to clarify the characteristics of patients with decreased cognitive function undergoing treatment for acute exacerbation phase of chronic heart failure as a basic survey with a view to the... The purpose of this study is to clarify the characteristics of patients with decreased cognitive function undergoing treatment for acute exacerbation phase of chronic heart failure as a basic survey with a view to the standardization of nursing to prevent discontinuation of treatment of patients with declining cognitive function in the acute exacerbation phase of chronic heart failure. As the first stage of the research, using the interview guide created based on the background of discontinuation of treatment and symptomatic monitoring from 33 target literature sources, seven certified chronic heart failure nurses and 15 certified dementia nurses were given semi-structured interviews. Data obtained from the interviews was analyzed by qualitative induction. As a result, we obtained opinions/views on 8 situations namely, “cognitive function at hospitalization”, “characteristics at hospitalization, “characteristics when receiving examinations, procedures or treatment”, “characteristics of course of treatment”, “characteristics related to difficulties in grasping the symptoms of chronic heart failure and indices of deterioration”, “characteristics when using diuretics”, “characteristics concerning compliance with dietary restrictions” and “support required for discharge from hospital” concerning patients with declining cognitive function. In the future, it is necessary to prepare nursing protocols incorporating these contents for standardization of nursing. 展开更多
关键词 Heart failure ACUTE Exacerbation ACUTE Phase DEMENTIA Physical Disorder DIFFICULT to Respond DIFFICULT Care NURSING Behavioral and Psychological Symptoms of DEMENTIA (BPSD)
下载PDF
Rapid, Non-Destructive, Textile Classification Using SIMCA on Diffuse Near-Infrared Reflectance Spectra 被引量:2
4
作者 Christopher B. Davis Kenneth W. Busch +2 位作者 Dennis H. Rabbe Marianna A. Busch Judith R. Lusk 《Journal of Modern Physics》 2015年第6期711-718,共8页
Soft independent modeling of class analogy (SIMCA) was successful in classifying a large library of 758 commercially available, non-blended samples of acetate, cotton, polyester, rayon, silk and wool 89% - 98% of the ... Soft independent modeling of class analogy (SIMCA) was successful in classifying a large library of 758 commercially available, non-blended samples of acetate, cotton, polyester, rayon, silk and wool 89% - 98% of the time at the 95% confidence level (p = 0.05 significance level). In the present study, cotton and silk had a 62% and 24% chance, respectively, of being classified with their own group and also with rayon. SIMCA correctly identified a counterfeit “silk” sample as polyester. When coupled with diffuse NIR reflectance spectroscopy and a large sample library, SIMCA shows considerable promise as a quick, non-destructive, multivariate method for fiber identification. A major advantage is simplicity. No sample pretreatment of any kind was required, and no adjust-ments were made for fiber origin, manufacturing process residues, topical finishes, weave pattern, or dye content. Increasing the sample library should make the models more robust and improve identification rates over those reported in this paper. 展开更多
关键词 diffuse NEAR-INFRARED (NIR) Reflectance Spectroscopy CHEMOMETRICS Soft Independent Modeling of Class ANALOGY (SIMCA) Pattern Recognition TEXTILE Identification Multivariate Analysis
下载PDF
Study on Sinking-Sliding Failure Mechanism of Perilous Rock at Wangxia in Three Gorges of the Yangtze River, China
5
作者 Hong-Kai Chen Sheng-Juan Wang 《Journal of Geoscience and Environment Protection》 2017年第2期30-43,共14页
The giant perilous rock at Wangxia (named Wangxia perilous rock) is representative in Three Gorges of the Yangtze River, China, has threatened badly the navigation of the Yangtze River channel for a long period. The g... The giant perilous rock at Wangxia (named Wangxia perilous rock) is representative in Three Gorges of the Yangtze River, China, has threatened badly the navigation of the Yangtze River channel for a long period. The giant perilous rock is composed of siliceous limestone and argillaceous limestone, and includes two elements marking by W1 and W2, respectively. The W1 is an isolated pillar while the W2 is in clintheriform. The linking segment of dominant fissure in the W2 is composed by moniliform solution funnels at its back, and the locked segment of the dominant fissure at the base of the W2 is composed by two parts. For the locked part of the dominant fissure of the W2, the upper segment shows the same lithology with the perilous rock and it can be simplified as an elastic medium, for the lower segment composed by argillaceous shale and mudstone can be simplified as a strain-softening medium. Introducing the water-softened function, the constitutive curves with two kinds of medium materials for the locked segment in the dominant fissure of the W2 have been proposed. Based on energy principle, the cusp catastrophe model for perilous rock rupture is built and formulas for the transient elastic and impulsive acceleration and the elastic-impulsive velocity of perilous rock catastrophe rupture have been established. By the calculation, the elastic-impulsive acceleration for the catastrophe rupture of the W2 is 531.4 m/s2, while the average elastic-impulsive velocity is 2.608 m/s. Further, it is deduced that the elastic-impulsive velocity at the base of the W2 is about 5.2 m/s. For the transient ruture of the W2, there is a greater speed difference between the top and the base of the W2, which impels the giant perilous rock to be retroverted sliding rupture, coinciding with the fact. Undoubtedly, studies in this paper must play an important role to analyze the catastrophe rupture mechanism of giant perilous rocks at both banks in Three Gorges of the Yangtze River, China. 展开更多
关键词 Sinking-Sliding failure MECHANISM Water-Softened Function CATASTROPHE Theory Energy Principle Giant Perilous Rock Three Gorges of the YANGTZE River China
下载PDF
荧光相关光谱单分子检测系统的研究 被引量:5
6
作者 张普敦 任吉存 《分析化学》 SCIE EI CAS CSCD 北大核心 2005年第7期899-903,共5页
基于激光共焦构型,构建了一套高灵敏度和高稳定性的荧光相关光谱单分子检测系统。采用高数值孔径物镜使激光束高度聚焦,并用同一物镜收集样品的荧光,单光子计数器用于实时记录荧光信号。优化系统保持物镜焦点、针孔以及单光子计数器光... 基于激光共焦构型,构建了一套高灵敏度和高稳定性的荧光相关光谱单分子检测系统。采用高数值孔径物镜使激光束高度聚焦,并用同一物镜收集样品的荧光,单光子计数器用于实时记录荧光信号。优化系统保持物镜焦点、针孔以及单光子计数器光敏区高度同轴。采用60×1.2(NA)的水浸物镜及直径为160μm的针孔得到的检测系统结构参数为ω0和z0分别为0.42μm和1.33μm,照射微区的体积为1.3fL。单个RhodamineGreen分子可获得13倍的信噪比。用该系统获得了小分子和生物大分子(DNA片段和蛋白质)的高质量荧光相关图谱,成功实现了单个分子的检测。 展开更多
关键词 Green DNA
下载PDF
急性肾功能衰竭兔血小板聚集功能、PGI_2、TXA_2、ET的变化 被引量:3
7
作者 刘久波 欧阳静萍 +4 位作者 陈林 朱少铭 李艳 彭新民 兰永社 《郧阳医学院学报》 2005年第1期6-8,F002,共4页
目的:探讨实验性急性肾功能衰竭 (Acuterenalfailure, ARF)兔血小板聚集功能、PGI2、TXA2、内皮素(Endothelins,ET)的变化与心肌组织形态学变化的关系。方法:实验分为 2组。对照组 (8只 ):用生理盐水 10ml/ 行后肢肌肉内加压注射。ARF组... 目的:探讨实验性急性肾功能衰竭 (Acuterenalfailure, ARF)兔血小板聚集功能、PGI2、TXA2、内皮素(Endothelins,ET)的变化与心肌组织形态学变化的关系。方法:实验分为 2组。对照组 (8只 ):用生理盐水 10ml/ 行后肢肌肉内加压注射。ARF组(12只):用 50%甘油 10mg/kg后肢肌肉内加压注射。检测各组不同时相血小板聚集功能等指标。结果: 2h、24hARF组与对照组比较:ARF组血小板聚集性明显增高(P<0. 01),TXA2、ET明显升高(P<0. 01), 6 Keto PGF1a明显降低(P<0. 01)。心肌组织出现严重的缺血性损害,主要为:心肌细胞弥漫性变性、心肌纤维间质水肿、血管周围水肿等。结论: ARF时血小板聚集性改变以及血管活性物质和氧自由基增高可能是造成心肌组织缺血性损害的直接原因之一。 展开更多
关键词 TXA2 PGI2 (Acute 6-KETO-PGF1A ET failure renal ARF 10ml
下载PDF
Advances in Research on Treatment of Heart Failure with Yangxinshi Tablet 被引量:1
8
作者 Jian LI Zhixiao WANG +1 位作者 Xinling ZHOU Yihong JIANG 《Medicinal Plant》 CAS 2020年第2期16-20,共5页
The advances in the treatment of heart failure with Yangxinshi tablet are reviewed in this paper.Yangxinshi tablet has effects of nourishing myocardia,improving myocardial metabolism,reducing myocardial oxygen consump... The advances in the treatment of heart failure with Yangxinshi tablet are reviewed in this paper.Yangxinshi tablet has effects of nourishing myocardia,improving myocardial metabolism,reducing myocardial oxygen consumption,dilating coronary artery,improving cardiac blood supply,reducing blood viscosity and improving microcirculation,and it can improve the functions of heart and curative effect of heart failure. 展开更多
关键词 Yangxinshi TABLET HEART failure Advance Mechanism Qi deficiency and blood STASIS type Coronary HEART failure Pulmonary HEART disease ANEMIC CARDIOPATHY
下载PDF
Application of Optical Methods in Blood Studies upon Evaluation of Severity Rate of Diffuse Liver Pathology
9
作者 Margarita Kruchinina Mikhail Voevoda +6 位作者 Sergey Peltek Svetlana Kurilovich Abdrey Gromov Vladimir Kruchinin Sergey Rykhlitsky Vladimir Volodin Vladimir Generalov 《Journal of Analytical Sciences, Methods and Instrumentation》 2013年第2期115-123,共9页
Possible early diagnostic application of optical methods (dielectrophoresis, spectral and imaging ellipsometry, Fourier-transform infrared spectroscopy, Raman spectroscopy) in studies of red blood cells and serum of p... Possible early diagnostic application of optical methods (dielectrophoresis, spectral and imaging ellipsometry, Fourier-transform infrared spectroscopy, Raman spectroscopy) in studies of red blood cells and serum of patients with diffuse liver disease with varying degrees of fibrosis has been evaluated. Application of combined optical methods was confirmed to significantly improve the performance of sensitivity, specificity, and accuracy index as well as to achieve the reliable results in diagnosis of both severe fibrosis and slight ulterior liver fibrosis. Identified diagnostic potential of optical methods can be effectively utilized in noninvasive screening evaluation of stages of diffuse liver disease of various geneses. 展开更多
关键词 Optical Methods Blood Serum STUDIES Erythrocytes diffuse Liver Disease Degree of FIBROSIS Dielectrophoresis ELLIPSOMETRY Raman SPECTROSCOPY IR Fourier SPECTROSCOPY
下载PDF
Restoring the Treg cell to Th17 cell ratio may alleviate HBV-related acute-on-chronic liver failure 被引量:35
10
作者 Ying-Hua Niu Dong-Lin Yin +7 位作者 Hong-Li Liu Rui-Tian Yi Yu-Cong Yang Hong-An Xue Tian-Yan Chen Shu-Lin Zhang Shu-Mei Lin Ying-Ren Zhao 《World Journal of Gastroenterology》 SCIE CAS 2013年第26期4146-4154,共9页
AIM: To investigate the role of T helper 17 cells (Th17) and regulatory T cells (Treg) in hepatitis B virus (HBV)-related acute-on-chronic liver failure (ACLF).METHODS: We enrolled 79 patients with HBV infection into ... AIM: To investigate the role of T helper 17 cells (Th17) and regulatory T cells (Treg) in hepatitis B virus (HBV)-related acute-on-chronic liver failure (ACLF).METHODS: We enrolled 79 patients with HBV infection into the study, 50 patients with HBV-related ACLF and 29 patients with chronic hepatitis B (CHB), from the First Affiliated Hospital of Medical College from January 2009 to June 2012. The ACLF patients were diagnosed according to the criteria recommended by The 19th Conference of the Asian Pacific Association for the Study of the Liver in 2009. Twenty healthy individuals with a similar gender and age structures to the two patient groups were also included as the normal controls (NC). Of the 50 ACLF patients, 28 were subsequently classified as non-survivors: 19 patients died from multiorgan failure, 3 underwent liver transplantation, and 6 discontinued therapy during follow-up because of financial reasons. The remaining 22 ACLF patients whose liver and anticoagulation function recovered to nearly normal levels within the next 6 mo were classified as survivors. The number of circulating Treg and Th17 cells was determined upon diagnosis and during the 8th week of follow-up through flow cytometry. RESULTS: The percentage of circulating Treg cells in the ACLF group was significantly higher than that in the CHB group (5.50% ± 1.15% vs 3.30% ± 1.13%, P < 0.01). The percentages of circulating Th17 cells in the ACLF and the CHB groups were significantly higher than that in the NC group (6.32% ± 2.22% vs 1.56% ± 0.44%, P < 0.01; 3.53% ± 1.65% vs 1.56% ± 0.44%, P < 0.01). No significant difference in Treg cell to Th17 cell ratio was observed between the ACLF group and the CHB group (0.98 ± 0.44 vs 1.12 ± 0.64, P = 0.991), whereas those in the two HBV infection groups were significantly lower than that in the NC group (1.85 ± 1.22; both P < 0.01). The percentage of Treg cells in the survivors during the 8th week of follow-up was significantly lower than that during peak ACLF severity [total bilirubin (TBIL) peak] (3.45% ± 0.97% vs 5.18% ± 1.02%, P < 0.01). The percentage of Th17 cells in survivors during the 8th week of follow-up was significantly lower than that during the peak TBIL (2.89% ±0.60% vs 5.24% ± 1.46%; P < 0.01). The Treg cell to Th17 cell ratio during the 8 th week of follow-up was significantly higher than that during the TBIL peak (1.22 ± 0.36 vs 1.10 ± 0.54; P < 0.05). CONCLUSION: Restoring the Treg cell to Th17 cell ratio during the follow-up phase of ACLF could maintain the immune system at a steady state, which favours good prognosis. 展开更多
关键词 Hepatitis B virus Acute-on-chronic liver failure Regulatory T CELLS T HELPER 17 CELLS Treg CELL to TH17 CELL RATIO
下载PDF
Clinical characteristics and outcomes associated with nasal intermittent mandatory ventilation in acute pediatric respiratory failure 被引量:1
11
作者 Billy C Wang Theodore Pei +4 位作者 Cheryl B Lin Rong Guo David Elashoff James A Lin Carol Pineda 《World Journal of Critical Care Medicine》 2018年第4期46-51,共6页
AIM To characterize the clinical course and outcomes of nasal intermittent mandatory ventilation(NIMV) use in acute pediatric respiratory failure.METHODS We identified all patients treated with NIMV in the pediatric i... AIM To characterize the clinical course and outcomes of nasal intermittent mandatory ventilation(NIMV) use in acute pediatric respiratory failure.METHODS We identified all patients treated with NIMV in the pediatric intensive care unit(PICU) or inpatient general pediatrics between January 2013 and December 2015 at two academic centers.Patients who utilized NIMV with other modes of noninvasive ventilation during the same admission were included.Data included demographics,vital signs on admission and prior to initiation of NIMV,pediatric risk of mortality Ⅲ(PRIsM-Ⅲ) scores,complications,respiratory support characteristics,PICU and hospital length of stays,duration of respiratory support,and complications.Patients who did not require escalation to mechanical ventilation were defined as NIMV responders;those who required escalation to mechanical ventilation(MV) were defined as NIMV nonresponders.NIMV responders were compared to NIMV non-responders.RESULTS Forty-two patients met study criteria.six(14%) failed treatment and required MV.The majority of the patients(74%) had a primary diagnosis of bronchiolitis.The median age of these 42 patients was 4 mo(range 0.5-28.1 mo,IQR 7,P = 0.69).No significant difference was measured in other baseline demographics and vitals on initiation of NIMV;these included age,temperature,respiratory rate,O2 saturation,heart rate,systolic blood pressure,diastolic blood pressure,and PRIsM-Ⅲ scores.The duration of NIMV was shorter in the NIMV nonresponder vs NIMV responder group(6.5 h vs 65 h,P < 0.0005).Otherwise,NIMV failure was not associated with significant differences in PICU length of stay(LOs),hospital LOs,or total duration of respiratory support.No patients had aspiration pneumonia,pneumothorax,or skin breakdown.CONCLUSION Most of our patients responded to NIMV.NIMV failure is not associated with differences in hospital LOs,PICU LOs,or duration of respiratory support. 展开更多
关键词 Continuous POSITIVE AIRWAY PRESSURE Pediatric Noninvasive POSITIVE PRESSURE ventilation NASAL INTERMITTENT MANDATORY ventilation High flow NASAL cannula Acute respiratory failure Bilevel POSITIVE AIRWAY PRESSURE
下载PDF
End-stage liver disease score and future liver remnant volume predict post-hepatectomy liver failure in hepatocellular carcinoma 被引量:17
12
作者 Fan-Hua Kong Xiong-Ying Miao +5 位作者 Heng Zou Li Xiong Yu Wen Bo Chen Xi Liu Jiang-Jiao Zhou 《World Journal of Clinical Cases》 SCIE 2019年第22期3734-3741,共8页
BACKGROUND Hepatocellular carcinoma(HCC)is the world’s sixth most common malignant tumor and the third cause of cancer death.Although great progress has been made in hepatectomy,it is still associated with a certain ... BACKGROUND Hepatocellular carcinoma(HCC)is the world’s sixth most common malignant tumor and the third cause of cancer death.Although great progress has been made in hepatectomy,it is still associated with a certain degree of risk of posthepatectomy liver failure(PHLF),which extends the length of hospital stay and remains the leading cause of postoperative death.Studies have shown that assessment of hepatic functional reserve before hepatectomy is beneficial for reducing the incidence of PHLF.AIM To assess the value of model for end-stage liver disease(MELD)score combined with standardized future liver remnant(sFLR)volume in predicting PHLF in patients undergoing hepatectomy for HCC.METHODS This study was attended by 238 patients with HCC who underwent hepatectomy between January 2015 and January 2018.Discrimination of sFLR volume,MELD score,and sFLR/MELD ratio to predict PHLF was evaluated according to the area under the receiver operating characteristic curve.RESULTS The patients were divided into two groups according to whether PHLF occurred after hepatectomy.The incidence of PHLF was 8.4%in our research.The incidence of PHLF increased with the decrease in sFLR volume and the increase in MELD score.Both sFLR volume and MELD score were considered independent predictive factors for PHLF.Moreover,the cut-off value of the sFLR/MELD score to predict PHLF was 0.078(P<0.001).This suggests that an sFLR/MELD≥0.078 indicates a higher incidence of PHLF than an sFLR/MELD<0.078.CONCLUSION MELD combined with sFLR is a reliable and effective PHLF predictor,which is superior to MELD score or sFLR volume alone. 展开更多
关键词 Post-hepatectomy LIVER failure Hepatocellular carcinoma HEPATECTOMY Model for END-STAGE LIVER disease Standardized FUTURE LIVER REMNANT Hepatitis B virus
下载PDF
连续性血液净化治疗心脏术后急性肾功能衰竭的效果评价 被引量:5
13
作者 连耀国 杜娟丽 +3 位作者 王汉民 陈威 刘晓渭 刘宏宝 《陕西医学杂志》 CAS 北大核心 2005年第7期777-780,共4页
目的:观察连续性血液净化(CBP)在心脏术后急性肾功能衰竭(ARF)患者防治中的疗效,并探讨CBP治疗的时机。方法:将18例心脏术后ARF患者分为A组(n=8,符合SIRS诊断)及B组(n=10,符合MODS诊断),对全部患者治疗前和治疗24h后进行ATN-ISI评分、AP... 目的:观察连续性血液净化(CBP)在心脏术后急性肾功能衰竭(ARF)患者防治中的疗效,并探讨CBP治疗的时机。方法:将18例心脏术后ARF患者分为A组(n=8,符合SIRS诊断)及B组(n=10,符合MODS诊断),对全部患者治疗前和治疗24h后进行ATN-ISI评分、APACHE评分,同时记录氧合指数,平均动脉压(MAP),心率(HR),中心静脉压(CVP),pH值,血尿素氮(BUN)和血肌酐(Scr)等指标进行比较。结果:1B组的病死率明显高于A组(70.0%vs12.5%);2CBP治疗24h后,A组及B组的APACHE评分、氧合指数、BUN和Scr显著改善,仅A组的MAP,pH值显著改善;而两组病人ATN-ISI评分、CVP、HR在治疗前后无明显差异。结论:CBP能改善心脏术后重症ARF的病情,但必须强调尽早认识SIRS并行CBP治疗,从而减少并发症的发生,降低病死率。 展开更多
关键词 APACHE (HR) SIRS CBP MODS 尿 ARF 24h pH B Scr BUN MAP CVP
下载PDF
Bayesian Inference and Prediction of Burr Type XII Distribution for Progressive First Failure Censored Sampling 被引量:1
14
作者 Ahmed A. Soliman A. H. Abd Ellah +1 位作者 N. A. Abou-Elheggag A. A. Modhesh 《Intelligent Information Management》 2011年第5期175-185,共11页
This paper deals with Bayesian inference and prediction problems of the Burr type XII distribution based on progressive first failure censored data. We consider the Bayesian inference under a squared error loss functi... This paper deals with Bayesian inference and prediction problems of the Burr type XII distribution based on progressive first failure censored data. We consider the Bayesian inference under a squared error loss function. We propose to apply Gibbs sampling procedure to draw Markov Chain Monte Carlo (MCMC) samples, and they have in turn, been used to compute the Bayes estimates with the help of importance sampling technique. We have performed a simulation study in order to compare the proposed Bayes estimators with the maximum likelihood estimators. We further consider two sample Bayes prediction to predicting future order statistics and upper record values from Burr type XII distribution based on progressive first failure censored data. The predictive densities are obtained and used to determine prediction intervals for unobserved order statistics and upper record values. A real life data set is used to illustrate the results derived. 展开更多
关键词 BURR TYPE XII DISTRIBUTION PROGRESSIVE First-failure Censored Sample Bayesian Estimations Gibbs Sampling Markov Chain Monte Carlo Posterior Predictive Density
下载PDF
Bayesian Joint Modelling of Survival Time and Longitudinal CD4 Cell Counts Using Accelerated Failure Time and Generalized Error Distributions 被引量:1
15
作者 Markos Abiso Erango Ayele Taye Goshu 《Open Journal of Modelling and Simulation》 2019年第1期79-95,共17页
Survival of HIV/AIDS patients is crucially dependent on comprehensive and targeted medical interventions such as supply of antiretroviral therapy and monitoring disease progression with CD4 T-cell counts. Statistical ... Survival of HIV/AIDS patients is crucially dependent on comprehensive and targeted medical interventions such as supply of antiretroviral therapy and monitoring disease progression with CD4 T-cell counts. Statistical modelling approaches are helpful towards this goal. This study aims at developing Bayesian joint models with assumed generalized error distribution (GED) for the longitudinal CD4 data and two accelerated failure time distributions, Lognormal and loglogistic, for the survival time of HIV/AIDS patients. Data are obtained from patients under antiretroviral therapy follow-up at Shashemene referral hospital during January 2006-January 2012 and at Bale Robe general hospital during January 2008-March 2015. The Bayesian joint models are defined through latent variables and association parameters and with specified non-informative prior distributions for the model parameters. Simulations are conducted using Gibbs sampler algorithm implemented in the WinBUGS software. The results of the analyses of the two different data sets show that distributions of measurement errors of the longitudinal CD4 variable follow the generalized error distribution with fatter tails than the normal distribution. The Bayesian joint GED loglogistic models fit better to the data sets compared to the lognormal cases. Findings reveal that patients’ health can be improved over time. Compared to the males, female patients gain more CD4 counts. Survival time of a patient is negatively affected by TB infection. Moreover, increase in number of opportunistic infection implies decline of CD4 counts. Patients’ age negatively affects the disease marker with no effects on survival time. Improving weight may improve survival time of patients. Bayesian joint models with GED and AFT distributions are found to be useful in modelling the longitudinal and survival processes. Thus we recommend the generalized error distributions for measurement errors of the longitudinal data under the Bayesian joint modelling. Further studies may investigate the models with various types of shared random effects and more covariates with predictions. 展开更多
关键词 ACCELERATED failure Time BAYESIAN Joint Model CD4 Cell COUNT Generalized Error Distribution HIV/AIDS Longitudinal Survival Analysis
下载PDF
踝臂指数评价血液透析患者下肢外周动脉病多中心临床研究 被引量:13
16
作者 王领军 胡大一 +7 位作者 吴华 闫明珠 逯春鹏 魏毅东 余金明 布艾加尔 仝其广 王锦纹 《中国医刊》 CAS 2005年第6期32-34,共3页
目的通过测量踝臂指数(Anklebrachialindex,ABI)评价我国慢性肾功能不全(chronicrenalfailure,CRF)血液透析(hemodialysis,HD)患者下肢外周动脉病(peripheralarterialdisease,PAD)的患病情况。方法对连续入选的271例行HD的CRF患者进行... 目的通过测量踝臂指数(Anklebrachialindex,ABI)评价我国慢性肾功能不全(chronicrenalfailure,CRF)血液透析(hemodialysis,HD)患者下肢外周动脉病(peripheralarterialdisease,PAD)的患病情况。方法对连续入选的271例行HD的CRF患者进行踝臂指数测定,并进行资料收集和统计学处理。结果271例患者中61例合并下肢外周动脉病(平均ABI0.62),其中只有4例(6.6%)患者得到了明确的诊断。PAD组与非PAD组患者相比,年龄(P=0.000)、糖尿病史(P=0.000)、血脂异常史(P=0.000)、吸烟量(P=0.002)和血肌酐水平(P=0.000)有统计学意义,而吸烟史(P=0.087)、高血压病史(P=0.053)无统计学意义。结论血液透析患者容易合并下肢PAD,ABI筛查下肢PAD简便易行;血液透析患者合并下肢PAD多见于高龄、糖尿病、血脂异常患者和大量吸烟患者。 展开更多
关键词 arterial failure disease index renal PAD 尿 ABI CRF
下载PDF
Evaluation of the effect of geometrical parameters on stope probability of failure in the open stoping method using numerical modeling 被引量:12
17
作者 Shahriyar Heidarzadeh Ali Saeidi Alain Rouleau 《International Journal of Mining Science and Technology》 SCIE EI CSCD 2019年第3期399-408,共10页
Stress-induced failure is among the most common causes of instability in Canadian deep underground mines.Open stoping is the most widely practiced underground excavation method in these mines,and creates large stopes ... Stress-induced failure is among the most common causes of instability in Canadian deep underground mines.Open stoping is the most widely practiced underground excavation method in these mines,and creates large stopes which are subjected to stress-induced failure.The probability of failure(POF)depends on many factors,of which the geometry of an open stope is especially important.In this study,a methodology is proposed to assess the effect of stope geometrical parameters on the POF,using numerical modelling.Different ranges for each input parameter are defined according to previous surveys on open stope geometry in a number of Canadian underground mines.A Monte-Carlo simulation technique is combined with the finite difference code FLAC3D,to generate model realizations containing stopes with different geometrical features.The probability of failure(POF)for different categories of stope geometry,is calculated by considering two modes of failure;relaxation-related gravity driven(tensile)failure and rock mass brittle failure.The individual and interactive effects of stope geometrical parameters on the POF,are analyzed using a general multi-level factorial design.Finally,mathematical optimization techniques are employed to estimate the most stable stope conditions,by determining the optimal ranges for each stope’s geometrical parameter. 展开更多
关键词 STOPE stability STOPE GEOMETRICAL parameters PROBABILITY of failure General FACTORIAL design Numerical modeling Sublevel OPEN STOPING
下载PDF
Increased CD163 expression is associated with acute-on-chronic hepatitis B liver failure 被引量:13
18
作者 Hong Ye Li-Yuan Wang +1 位作者 Jing Zhao Kai Wang 《World Journal of Gastroenterology》 SCIE CAS 2013年第18期2818-2825,共8页
AIM: To assess CD163 expression in plasma and peripheral blood and analyze its association with disease in acute-on-chronic hepatitis B liver failure (ACHBLF) patients. METHODS: A retrospective study was conducted fro... AIM: To assess CD163 expression in plasma and peripheral blood and analyze its association with disease in acute-on-chronic hepatitis B liver failure (ACHBLF) patients. METHODS: A retrospective study was conducted from January 1, 2011 to January 1, 2012. Forty patients with ACHBLF (mean age 44.48 ± 12.28 years, range 18-69 years), 40 patients with chronic hepatitis B (CHB) (mean age 39.45 ± 12.22 years, range 21-57 years) and 20 ageand sex-matched healthy controls (mean age 38.35 ± 11.97 years, range 28-60 years) were included in this study. Flow cytometry was used to analyze the frequency of CD163+ peripheral blood mononuclear cells (PBMCs) and surface protein expression of CD163. Real-time transcription-polymerase chain re-action was performed to assess relative CD163 mRNA levels in PBMCs. Plasma soluble CD163 (sCD163) levels were measured by enzyme-linked immunosorbent assay. Clinical variables were also recorded. Comparisons between groups were analyzed by Kruskal-Wallis H test and Mann-Whitney U test. Statistical analyses were performed using SPSS 15.0 software and a P value < 0.05 was considered statistically significant. RESULTS: Flow cytometry showed that the population of CD163+ PBMCs was significantly greater in ACHBLF patients than in CHB patients and healthy controls (47.9645% ± 17.1542%, 32.0975% ± 11.0215% vs 17.9460% ± 6.3618%, P < 0.0001). However, there were no significant differences in mean fluorescence intensity of CD163+ PBMCs within the three groups (27.4975 ± 11.3731, 25.8140 ± 10.0649 vs 20.5050 ± 6.2437, P = 0.0514). CD163 mRNA expression in ACHBLF patients was significantly increased compared with CHB patients and healthy controls (1.41 × 10 -2 ± 2.18 × 10 -2 , 5.10 × 10 -3 ± 3.61 × 10 -3 vs 37.0 × 10 -4 ± 3.55 × 10 -4 , P = 0.02). Plasma sCD163 levels in patients with ACHBLF were significantly increased compared with CHB patients and healthy controls (4706.2175 ± 1681.1096 ng/mL, 1089.7160 ± 736.8395 ng/mL vs 435.9562 ± 440.8329 ng/mL, P < 0.0001). In ACHBLF patients, plasma sCD163 levels were significantly positively associated with model for end-stage liver disease scores (r = 0.5075, P = 0.008), hepatitis B virus-DNA (r = 0.6827, P < 0.0001), and negatively associated with prothrombin activity (r = -0.3348, P = 0.0347), but had no correlation with total bilirubin (r = 0.2551, P = 0.1122). Furthermore, sCD163 was obviously elevated in non-surviving patients compared with surviving patients with ACHBLF (5344.9080 ± 1589.5199 ng/mL vs 3641.7333 ± 1264.5228 ng/mL, P = 0.0321). CONCLUSION: CD163 and sCD163 may be related to disease severity and prognosis in ACHBLF patients. 展开更多
关键词 Acute-on-chronic hepatitis B LIVER failure Model for END-STAGE LIVER disease CD163 Soluble CD163 Real-time transcription-polymerase chain reaction
下载PDF
扩散致相转化法制备结晶性聚合物多孔膜 被引量:7
19
作者 杨振生 李凭力 +1 位作者 常贺英 王世昌 《高分子通报》 CAS CSCD 2005年第3期123-127,共5页
介绍了扩散致相转化法制备结晶性聚合物多孔膜的研究现状。其三元等温成膜体系的相图包含液液分相和固液分相两种相分离方式,是理解成膜过程的重要工具,总结了成膜机理和膜的结构形貌:单纯S L相分离生成粒子状对称膜结构;单纯L L相分离... 介绍了扩散致相转化法制备结晶性聚合物多孔膜的研究现状。其三元等温成膜体系的相图包含液液分相和固液分相两种相分离方式,是理解成膜过程的重要工具,总结了成膜机理和膜的结构形貌:单纯S L相分离生成粒子状对称膜结构;单纯L L相分离生成蜂窝状非对称膜结构;两种相分离方式竞争发生将生成多样的混合膜结构。铸膜液浓度、非溶剂种类、铸膜溶剂组成、凝胶浴组成、制膜温度是影响膜结构形貌的主要因素。 展开更多
关键词 - -
下载PDF
利用总变分最小化方法的无监督纹理图像分割 被引量:4
20
作者 蔡国雷 杨鸿波 邹谋炎 《中国图象图形学报(A辑)》 CSCD 北大核心 2005年第4期489-493,共5页
纹理图像的分割是图像处理领域中的一个典型难题。不同于传统的提取纹理特征量进行纹理分割的方法,本文将图像复原和重建中的总变分最小化方法和活动围道分割方法相结合,提出了一种简单的线性纹理模型。利用总变分最小化方法在保持图像... 纹理图像的分割是图像处理领域中的一个典型难题。不同于传统的提取纹理特征量进行纹理分割的方法,本文将图像复原和重建中的总变分最小化方法和活动围道分割方法相结合,提出了一种简单的线性纹理模型。利用总变分最小化方法在保持图像大尺度棱边信息的基础上对纹理体现的局部小尺度周期性灰度振动细节进行平滑得到简化的图像原型。对其进行分割获得不同纹理区域之间的低定位精度的边界围道,再利用原始图像对围道进行高精度细化。在总变分最小化导致的非线性扩散方程求解过程中,运用AOS(additiveoperatorsplitting)数值算法以改进算法效率。实验结果表明,该方法能很快提取出纹理图像的简化图像,同时是一种无监督的纹理分割方法。 展开更多
关键词 线
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部