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玉米秸秆的力学特性测试研究 被引量:150
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作者 高梦祥 郭康权 +1 位作者 杨中平 李星恕 《农业机械学报》 EI CAS CSCD 北大核心 2003年第4期47-49,52,共4页
对玉米秸秆的茎叶连接力、叶鞘的抗拉特性和茎秆、叶鞘的抗冲击特性进行了测试。结果表明 :这些力学特性是玉米秸秆的固有特性 ,具有统计规律性。茎叶连接力为 0 .7~ 16 N ,叶鞘抗拉力为 3~ 2 1N,叶鞘抗冲击能量为 0 .5~ 3.8J,茎秆... 对玉米秸秆的茎叶连接力、叶鞘的抗拉特性和茎秆、叶鞘的抗冲击特性进行了测试。结果表明 :这些力学特性是玉米秸秆的固有特性 ,具有统计规律性。茎叶连接力为 0 .7~ 16 N ,叶鞘抗拉力为 3~ 2 1N,叶鞘抗冲击能量为 0 .5~ 3.8J,茎秆抗冲击能量为 2 .3~ 4 2 .8J。并对影响这些特性的因素及其变化规律进行了分析。 展开更多
关键词 玉米秸秆 贮藏 力学特性 测试技术 茎叶连接力 叶鞘 抗拉特性 统计规律性
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冻融作用后混凝土力学性能的衰减规律 被引量:106
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作者 邹超英 赵娟 +2 位作者 梁锋 罗健林 徐天水 《建筑结构学报》 EI CAS CSCD 北大核心 2008年第1期117-123,138,共8页
开展了混凝土在冻融作用后各项基本力学性能衰减规律的试验研究,包括冻融作用对混凝土受压应力-应变关系、劈裂抗拉性能、抗重复荷载性能的损伤影响,并根据工程中结构构件的实际工作状态,进行了压应力与冻融循环双重因子作用下混凝土的... 开展了混凝土在冻融作用后各项基本力学性能衰减规律的试验研究,包括冻融作用对混凝土受压应力-应变关系、劈裂抗拉性能、抗重复荷载性能的损伤影响,并根据工程中结构构件的实际工作状态,进行了压应力与冻融循环双重因子作用下混凝土的抗冻性能及力学性能衰减规律的研究。试验现象表明:随着冻融循环次数的增多,混凝土轴心抗压强度、劈裂抗拉强度、抗重复荷载性能等力学性能指标的下降程度均逐渐加大,并根据试验结果得出了混凝土上述各项力学性能指标随冻融作用的退化规律,建立了与冻融参数相关的退化计算公式。通过试验研究还发现:混凝土在承载状态下,冻融作用对其损伤影响将加剧,混凝土承载能力的衰减幅度较单一冻融作用更显著。本文研究可为建立符合实际工程的混凝土结构抗冻耐久性设计理论提供基础资料。 展开更多
关键词 混凝土 冻融作用 试验研究 损伤 力学性能
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土工织物与土相互作用的机理 被引量:50
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作者 王伟 杨尧志 《无锡轻工大学学报(食品与生物技术)》 CSCD 1999年第3期107-112,共6页
从三个方面探讨了土与土工织物相互作用机理,即土工织物接触界面间的摩擦特征;土与土工织物拉拔试验;加筋土应力与应变关系三轴试验研究.为进一步推广应用土工织物加筋软土地基提供了可靠的依据.
关键词 土工织物 作用机理 相互作用 土工布
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Animal experiment and clinical study of effect of gamma-interferon on hepatic fibrosis 被引量:53
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作者 Hong Lei Weng Wei Min Cai Rong Hua Liu Institute of Infectious Diseases, First Affiliated Hospital. Medical School. Zhejiang University, Hangzhou 310003, Zhejiang Province. China 《World Journal of Gastroenterology》 SCIE CAS CSCD 2001年第1期42-48,共7页
AIM: To evaluate the antifibrotic effect of different doses of recombinant human Gamma-Interferon (IFN-gamma) in two rat models of hepatic fibrosis, and to observe its effect on moderate chronic hepatitis B virus fibr... AIM: To evaluate the antifibrotic effect of different doses of recombinant human Gamma-Interferon (IFN-gamma) in two rat models of hepatic fibrosis, and to observe its effect on moderate chronic hepatitis B virus fibrosis. METHODS: Hepatic fibrosis was successfully induced in 150 and 196 rats by subcutaneous injection of carbon tetrachloride (CCl4) and intraperitoneal injection of dimethylnitrosamine (DMN), respectively. Each of the two model groups was divided into: (1) fibrotic model group; (2) colchicine treatment group (0.1 mg/kg/day, gastrogavage for 8 weeks); (3) high-dose IFN-gamma group (15 MU/kg per day, i.m. for 8 weeks); (4) medium-dose IFN-gamma group (5 MU/kg daily, i.m. for 8 weeks); and (5) Y low-dose IFN-gamma group (1.67 MU/kg daily, i.m. for 8 weeks). Another group of 10 rats without any treatment was used as normal controls. At the end of the experiment, semi-quantitative histopathological scores of inflammation and fibrosis, liver alpha smooth muscle actin (alpha-SMA) expression level, liver hydroxyl proline content and serum hyaluronic acid levels were compared. And 47 medium chronic hepatitis B viral fibrosis patients were studied. They were given IFN-gamma treatment, 100 MU/day i.m. for the first three months and 100 MU qod i.m. for the next six months. Semi-quantitative pathological scores of inflammation and fibrosis and serum hepatic fibrosis indices were compared within the 9 months. RESULTS: In animal experiment, the pathological fibrosis scores and liver hydroxyl proline content were found to be significantly lower in rats treated with different doses of IFN-gamma as compared with rats in fibrotic model group induced by either CCl4 or DMN, in a dose-dependent manner. For CCl4-induced model, pathological fibrosis scores in high, medium and low doses IFN-gamma groups were 5.10 +/- 2.88, 7.70 +/- 3.53 and 8.00 +/- 3.30, respectively, but the score was 14.60 +/- 7.82 in fibrotic model group. Hydroxyl proline contents were 2.83 +/- 1.18, 3.59 +/- 1.22 and 4.80 +/- 1.62, in the three IFN-ga 展开更多
关键词 Animals Antineoplastic Agents dosage Biopsy Carbon Tetrachloride DIMETHYLNITROSAMINE Disease Models Animal Female Hepatitis B Chronic Humans Hyaluronic Acid HYDROXYPROLINE Interferon-gamma Recombinant Liver Liver Cirrhosis Liver Function tests Male RATS Rats Sprague-Dawley
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Alterations in metastatic properties of hepatocellular carcinoma cell following H-ras oncogene transfection 被引量:48
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作者 Qing Wang~1 Zhi Ying Lin~2 Xiao Li Feng~3 ~1Department of Microbiology,Medical Center of Fudan University.the former Shanghai Medical University,Shanghai 200032,China ~2Liver Cancer Institute,Zhongshan Hospital,Shanghai 200032,China ~3Shanghai Institute of Biochemistry,Academy Sinica,Shanghai 200031,ChinaQing Wang earned master degree from Shanghai Medical University in 1996,now a senior lecturer of microbiology,specialized in the role of oncogcncs on tumor metastasis,having 8 papers published. 《World Journal of Gastroenterology》 SCIE CAS CSCD 2001年第3期335-339,共5页
AIM: To demonstrate the relationship between H-ras oncogene and hepatocellular carcinoma (HCC) metastasis. METHODS: Activated H-ras oncogene was transfected into SMMC 7721, a cell line derived from human HCC, by calci... AIM: To demonstrate the relationship between H-ras oncogene and hepatocellular carcinoma (HCC) metastasis. METHODS: Activated H-ras oncogene was transfected into SMMC 7721, a cell line derived from human HCC, by calcium phosphate transfection method. Some metastasis-related parameters were detected in vitro, including adhesion assay, migration assay, expression of collagenase IV(c IV ase) and epidermal growth factor receptor (EGFR). RESULTS: The abilities of H-ras-transfected cell clones in adhesion to laminin (LN) or fibronectin (FN), migration, c IV ase secretion increased markedly, and the expression of EGFR elevated moderately. More importantly, these alterations were consistent positively with the expression of p21, the protein product of H-ras oncogene. CONCLUSION: H-ras oncogene could induce the metastatic phenotype of HCC cell in vitro to raise its metastatic potential. 展开更多
关键词 Carcinoma Hepatocellular Cell Adhesion Cell Movement Gelatinase A Gelatinase B Gene Expression Regulation Neoplastic Genes ras Humans In Vitro Liver Neoplasms PHENOTYPE Predictive Value of tests Receptor Epidermal Growth Factor TRANSFECTION
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Accuracy of urea breath test in Helicobacter pylori infection: Meta-analysis 被引量:48
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作者 Mazen Ferwana Imad Abdulmajeed +7 位作者 Ali Alhajiahmed Wedad Madani Belal Firwana Rim Hasan Osama Altayar Paul J Limburg Mohammad Hassan Murad Bandar Knawy 《World Journal of Gastroenterology》 SCIE CAS 2015年第4期1305-1314,共10页
AIM: To quantitatively summarize and appraise the available evidence of urea breath test(UBT) use to diagnose Helicobacter pylori(H. pylori) infection in patients with dyspepsia and provide pooled diagnostic accuracy ... AIM: To quantitatively summarize and appraise the available evidence of urea breath test(UBT) use to diagnose Helicobacter pylori(H. pylori) infection in patients with dyspepsia and provide pooled diagnostic accuracy measures.METHODS: We searched MEDLINE, EMBASE, Cochrane library and other databases for studies addressing the value of UBT in the diagnosis of H. pylori infection. We included cross-sectional studies that evaluated the diagnostic accuracy of UBT in adult patients with dyspeptic symptoms. Risk of bias was assessed using QUADAS(Quality Assessment of Diagnostic Accuracy Studies)-2 tool. Diagnostic accuracy measures were pooled using the random-effects model. Subgroup analysis was conducted by UBT type(13C vs 14C) and by measurement technique(Infrared spectrometry vs Isotope Ratio Mass Spectrometry).RESULTS: Out of 1380 studies identified, only 23 met the eligibility criteria. Fourteen studies(61%) evaluated 13 C UBT and 9 studies(39%) evaluated 14 C UBT. There was significant variation in the type of reference standard tests used across studies.Pooled sensitivity was 0.96(95%CI: 0.95-0.97) andpooled specificity was 0.93(95%CI: 0.91-0.94). Likelihood ratio for a positive test was 12 and for a negative test was 0.05 with an area under thecurve of 0.985. Meta-analyses were associated with a significant statistical heterogeneity that remained unexplained after subgroup analysis. The included studies had a moderate risk of bias.CONCLUSION: UBT has high diagnostic accuracy for detecting H. pylori infection in patients with dyspepsia. The reliability of diagnostic meta-analytic estimates however is limited by significant heterogeneity. 展开更多
关键词 HELICOBACTER PYLORI DYSPEPSIA BREATH tests Urea/an
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兰州马兰黄土的物理力学特性 被引量:44
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作者 李保雄 牛永红 苗天德 《岩土力学》 EI CAS CSCD 北大核心 2007年第6期1077-1082,共6页
马兰黄土属水敏感性地质体,在水软化作用下,土体的物理力学与水理性质呈现出明显的规律性。采用不同的原位及室内试验方法,分别在兰州和荷兰尤怀特两地对兰州地区马兰黄土的工程地质性质进行了测试,系统研究了马兰黄土的物理力学特性。... 马兰黄土属水敏感性地质体,在水软化作用下,土体的物理力学与水理性质呈现出明显的规律性。采用不同的原位及室内试验方法,分别在兰州和荷兰尤怀特两地对兰州地区马兰黄土的工程地质性质进行了测试,系统研究了马兰黄土的物理力学特性。在大量黄土试验资料的基础上,对马兰黄土的工程地质特征进行了系统研究,重点论述了马兰黄土水敏感性和抗剪强度的变化规律,提出了马兰黄土的多项临界指标参数。 展开更多
关键词 马兰黄土 试验 物理力学性质 湿陷 界限含水率 抗剪强度
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Performance value of high risk factors in colorectal cancer screening in China 被引量:43
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作者 Wen Meng Shan-Rong Cai +3 位作者 Lun Zhou Qi Dong Shu Zheng Su-Zhan Zhang 《World Journal of Gastroenterology》 SCIE CAS CSCD 2009年第48期6111-6116,共6页
AIM:To analyze the performance value of high risk factors in population-based colorectal cancer(CRC) screening in China.METHODS:We compared the performance value of the immunochemical fecal occult blood test(iFOBT) an... AIM:To analyze the performance value of high risk factors in population-based colorectal cancer(CRC) screening in China.METHODS:We compared the performance value of the immunochemical fecal occult blood test(iFOBT) and other high risk factors questionnaire in a population sample of 13 214 community residents who completed both the iFOBT and questionnaire investigation.Patients with either a positive iFOBT and/or questionnaire were regarded as a high risk population and those eligible were asked to undergo colonoscopy.RESULTS:The iFOBT had the highest positive predictive value and negative predictive value in screening for advanced neoplasia.The iFOBT had the highest sensitivity,lowest number of extra false positive results associated with the detection of one extra abnormality for screening advanced neoplasias and adenomas.A history of chronic cholecystitis or cholecystectomy,chronic appendicitis or appendectomy,and chronic diarrhea also had a higher sensitivity than a history of adenomatous polyps in screening for advanced neoplasias and adenomas.The sensitivity of a history of chronic cholecystitis or cholecystectomy was highest among the 10 high risk factors in screening for nonadenomatous polyps.A history of chronic appendicitis or appendectomy,chronic constipation,chronic diarrhea,mucous and bloody stool,CRC in first degree relatives,malignant tumor and a positive iFOBT also had higher sensitivities than a history of adenomas polyps in screening for non-adenomatous polyps.Except for a history of malignant tumor in screening for non-adenomatous polyps,the gain in sensitivity was associated with an increase in extra false positive results associated with the detection of one extra abnormality.CONCLUSION:The iFOBT may be the best marker for screening for advanced neoplasias and adenomas.Some unique high risk factors may play an important role in CRC screening in China. 展开更多
关键词 Colorectal cancer Cancer screening FECES Occult blood Risk factors Predictive value of tests
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高温下钢筋混凝土异形柱的试验研究 被引量:39
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作者 吴波 徐玉野 《建筑结构学报》 EI CAS CSCD 北大核心 2007年第5期24-31,共8页
进行了11根钢筋混凝土异形柱和1根钢筋混凝土方形柱在ISO834标准升温过程下的明火试验,分析了轴压比和受火方式对高温下不同截面形状的钢筋混凝土柱的破坏形态、轴向变形,以及耐火极限等的影响。试验结果表明:(1)钢筋混凝土异形柱的耐... 进行了11根钢筋混凝土异形柱和1根钢筋混凝土方形柱在ISO834标准升温过程下的明火试验,分析了轴压比和受火方式对高温下不同截面形状的钢筋混凝土柱的破坏形态、轴向变形,以及耐火极限等的影响。试验结果表明:(1)钢筋混凝土异形柱的耐火性能明显低于方形柱。(2)轴压比对异形柱的耐火极限影响较大。(3)一般而言,十字形柱的耐火性能比T形柱好,T形柱比L形柱好;但当轴压比较大(例如0.55)时,T形柱的耐火性能有可能好于十字形柱。最后,利用三种高温下钢筋混凝土异形柱的数值分析模型对12根试验柱的耐火极限进行了计算,比较了不同模型的模拟效果。 展开更多
关键词 钢筋混凝土 异形柱 高温 试验 力学性能
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航空发动机高、低温起动及高原起动试验技术探讨 被引量:41
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作者 郭昕 杨志军 《航空动力学报》 EI CAS CSCD 北大核心 2003年第3期327-330,共4页
根据GJB241对航空发动机高、低温起动及高原起动试验的要求,分析了高、低温及高原环境条件对航空发动机起动性能的影响机理;阐述了利用自然环境条件、低温起动室及高空模拟试验台进行航空发动机高、低温起动及高原起动试验的优、缺点;... 根据GJB241对航空发动机高、低温起动及高原起动试验的要求,分析了高、低温及高原环境条件对航空发动机起动性能的影响机理;阐述了利用自然环境条件、低温起动室及高空模拟试验台进行航空发动机高、低温起动及高原起动试验的优、缺点;结合国产斯贝MK202发动机分别在英国R.R.公司低温起动室和高空模拟试车台进行的低温起动试验方法和俄罗斯中央航空发动机研究院(CIAM)高空台的发动机高、低温起动及高原起动试验的方法,提出了符合我国国情的航空发动机高、低温起动及高原起动试验的实施途径。 展开更多
关键词 航空发动机 高温起动 低温起动 高原起动 试验
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不锈钢材料常温力学性能试验研究 被引量:41
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作者 郑宝锋 舒赣平 沈晓明 《钢结构》 2011年第5期1-6,55,共7页
不锈钢作为一种新型的建筑结构材料,其力学性能与普通低碳钢相比具有明显的差异,主要表现在:具有非线性的应力 -应变关系、较低的比例极限、一定的各向异性、明显的应变硬化特性。目前国外已经对不锈钢材料的力学性能进行比较系统的研... 不锈钢作为一种新型的建筑结构材料,其力学性能与普通低碳钢相比具有明显的差异,主要表现在:具有非线性的应力 -应变关系、较低的比例极限、一定的各向异性、明显的应变硬化特性。目前国外已经对不锈钢材料的力学性能进行比较系统的研究。基于国产的304牌号不锈钢材料,对24组平板区材料进行拉伸试验、平板区材料压缩性能试验和转角区拉伸性能试验。试验结果表明:两阶段 R-O方程能够很好地模拟国产不锈钢材料的力学性能;另外,受冷加工影响,同牌号不锈钢材料的力学性能参数差别较大。最后,对不锈钢构件设计方法进行了展望。 展开更多
关键词 不锈钢 冷成型管材 材料力学性能 试验研究
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Effects of propofol, dexmedetomidine, and midazolam on postoperative cognitive dysfunction in elderly patients: a randomized controlled preliminary trial 被引量:40
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作者 Wei-Xia Li Ru-Yi Luo +4 位作者 Chao Chert Xiang Li Jing-Sheng AO Yue Liu Yi-Qing Yin 《Chinese Medical Journal》 SCIE CAS CSCD 2019年第4期437-445,共9页
Background: Postoperative cognitive dysfunction (POCD) is a serious complication after surgery, especially in elderly patients. The anesthesia technique is a potentially modifiable risk factor for POCD. This study ass... Background: Postoperative cognitive dysfunction (POCD) is a serious complication after surgery, especially in elderly patients. The anesthesia technique is a potentially modifiable risk factor for POCD. This study assessed the effects of dexmedetomidine, propofol or midazolam sedation on POCD in elderly patients who underwent hip or knee replacement under spinal anesthesia. Methods: The present study was a prospective randomized controlled preliminary trial. From July 2013 and December 2014, a total of 164 patients aged 65 years or older who underwent hip or knee arthroplasty at China-Japan Friendship Hospital and 41 non-surgical controls were included in this study. Patients were randomized in a 1:1:1 ratio to 3 sedative groups. All the patients received combined spinal-epidural anesthesia (CSEA) with midazolam, dexmedetomidine or propofol sedation. The sedative dose was adjusted to achieve light sedation (bispectral index[BIS] score between 70 and 85). All study participants and controls completed a battery of 5 neuropsychological tests before and 7 days after surgery. One year postoperatively, the patients and controls were interviewed over the telephone using the Montreal cognitive assessment 5-minute protocol. Results: In all, 60 of 164 patients (36.6%) were diagnosed with POCD 7 days postoperatively, POCD incidence in propofol group was significantly lower than that in dexmedetomidine and midazolam groups (18.2% vs. 40.0%, 51.9%, χ^2 6.342 and 13.603, P= 0.012 and < 0.001). When the patients were re-tested 1 year postoperatively, the incidence of POCD was not significantly different among the 3 groups (14.0%, 10.6% vs. 14.9%, χ^2 0.016 and 0.382, P= 0.899 and 0.536). Conclusion: Among dexmedetomidine, propofol and midazolam sedation in elderly patients, propofol sedation shows a significant advantage in term of short-term POCD incidence. 展开更多
关键词 Cognitive dysfunction NEUROPSYCHOLOGICAL tests POSTOPERATIVE period SEDATIVES
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Indocyanine green clearance test and model for end-stage liver disease score of patients with liver cirrhosis 被引量:37
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作者 Sheng, Qin-Song Lang, Ren +3 位作者 He, Qiang Yang, Yong-Jiu Zhao, De-Fang Chen, Da-Zhi 《Hepatobiliary & Pancreatic Diseases International》 SCIE CAS 2009年第1期46-49,共4页
BACKGROUND: The indocyanine green (ICG) clearance test (clearance rate (K) and retention rate at 15 minutes (R(15))) is a sensitive indicator to evaluate liver function. The model for end-stage liver disease (MELD) sc... BACKGROUND: The indocyanine green (ICG) clearance test (clearance rate (K) and retention rate at 15 minutes (R(15))) is a sensitive indicator to evaluate liver function. The model for end-stage liver disease (MELD) score has emerged as a useful tool for estimating the mortality of patients awaiting liver transplantation and has recently been validated on patients with liver diseases of various etiologies and severity. In this study, we investigated the correlation between the ICG clearance test and MELD score of patients with liver cirrhosis. METHODS: From June 2007 to March 2008, 52 patients with liver cirrhosis admitted to our center were classified into Child-Pugh class A (8 patients), B (14) and C (30). The ICG clearance test (K value and R(15)) was performed by ICG pulse spectrophotometry (DDG-3300K), and the MELD scores of patients were calculated. RESULTS: As the Child-Pugh classification of liver function gradually deteriorated, the K value decreased, while R(15) and MELD score increased. There were significant statistical differences in K value, R(15) and MELD score in patients with different Child-Pugh classifications. Significant correlations were found between the parameters of the ICG clearance test (K value and R(15)) and MELD score. A negative correlation was observed between K value and MELD score (r=-0.892, P < 0.05), while a positive correlation was observed between R(15) and MELD score (r=0.804, P < 0.05). CONCLUSIONS: The ICG clearance test and MELD score are good parameters for evaluating liver function. Moreover, K value and R(15) have significant correlations with MELD score, especially the K value, which may be a convenient and appropriate indicator to evaluate liver function of patients with liver cirrhosis. 展开更多
关键词 liver function tests indocyanine green model for end-stage liver disease SPECTROPHOTOMETRY
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Measurement of hepatic functional mass by means of ^(13)C-methacetin and ^(13)C-phenylalanine breath tests in chronic liver disease: Comparison with Child-Pugh score and serum bile acid levels 被引量:35
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作者 D.Festi S.Capodicasa +9 位作者 L.Sandri L.Colaiocco-Ferrante T.Staniscia E.Vitacolonna A.Vestito R.Simoni G.Mazzella P.Portincasa E.Roda A.Colecchia 《World Journal of Gastroenterology》 SCIE CAS CSCD 2005年第1期142-148,共7页
AIM: To evaluate and compare the clinical usefulness of 13C-phenylalanine and 13C-methacetin breath tests in quantitating functional hepatic mass in patients with chronic liver disease and to further compare these res... AIM: To evaluate and compare the clinical usefulness of 13C-phenylalanine and 13C-methacetin breath tests in quantitating functional hepatic mass in patients with chronic liver disease and to further compare these results with those of conventional tests, Child-Pugh score and serum bile acid levels.METHODS: One hundred and forty patients (50 HCV-related chronic hepatitis, 90 liver cirrhosis patients) and 40 matched healthy controls were studied. Both breath test and routine liver test, serum levels of cholic and chenodeoxycholic acid conjugates were evaluated.RESULTS: Methacetin breath test, expressed as 60 min cumulative percent of oxidation, discriminated the hepatic functional capacity not only between controls and liver disease patients, but also between different categories of chronic liver disease patients. Methacetin breath test was correlated with liver function tests and serum bile acids.Furthermore, methacetin breath test, as well as serum bile acids, were highly predictive of Child-Pugh scores. The diagnostic power of phenylalanine breath test was always less than that of methacetin breath test.CONCLUSION: Methacetin breath test represents a safe and accurate diagnostic tool in the evaluation of hepatic functional mass in chronic liver disease patients. 展开更多
关键词 Chronic hepatitis c Liver cirrhosis Breath tests Hepatic functional mass
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实施《学生体质健康标准》的测试结果分析 被引量:29
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作者 孙艳 楼晓娟 +2 位作者 徐美敏 孙润兴 杨伟春 《西安体育学院学报》 北大核心 2004年第5期65-67,共3页
对照国家教育部、体育总局新颁布的《学生体质健康标准(试行方案)》,对东华大学体育课学习的2700名大学生进行了有关学生体质健康项目测试,给出了各项测试结果并进行分析。健康测试结果表明:体质健康达到及格线以上的学生达到99 6%;在... 对照国家教育部、体育总局新颁布的《学生体质健康标准(试行方案)》,对东华大学体育课学习的2700名大学生进行了有关学生体质健康项目测试,给出了各项测试结果并进行分析。健康测试结果表明:体质健康达到及格线以上的学生达到99 6%;在体质健康测试的五项指标中,身高标准体重指标项测试有接近50%的在校学生呈现体重超重、肥胖;其它四项指标均达到99%及格线以上。本校把测试项目作为体质健康的评价指标纳入体育课成绩管理,占体育课成绩的20%。 展开更多
关键词 《学生体质健康标准》 大学生 测试项目 评定方法 身高标准体重 肺活量体重指数 握力体重指数
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Diagnosis of Helicobacter pylori : What should be the gold standard? 被引量:31
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作者 Saurabh Kumar Patel Chandra Bhan Pratap +2 位作者 Ashok Kumar Jain Anil Kumar Gulati Gopal Nath 《World Journal of Gastroenterology》 SCIE CAS 2014年第36期12847-12859,共13页
Since the discovery of Helicobacter pylori (H. pylori) in 1983, numerous detection methods for the presence of the bacterium have been developed. Each one of them has been associated with advantages and disadvantages.... Since the discovery of Helicobacter pylori (H. pylori) in 1983, numerous detection methods for the presence of the bacterium have been developed. Each one of them has been associated with advantages and disadvantages. Noninvasive tests such as serology, <sup>13</sup>C urea breath test (UBT) and stool antigen tests are usually preferred by the clinicians. Serology has its own limitation especially in endemic areas while <sup>13</sup>C UBT is technically very demanding. The stool antigen detection method, although specific, is usually associated with poor sensitivity. The <sup>13</sup>C UBT is believed to be specific, but with present revelation of the fact that stomach is colonized by many other urease producing bacteria makes it questionable. Histology, culture, rapid urease test and polymerase chain reaction (PCR) are the tests which are carried out on antral biopsies collected by invasive means. Histology has been proposed to be very sensitive and specific but the question is how by simply looking the morphology of the bacteria in the microscope, one can claim that the curved bacterium is exclusively H. pylori. Rapid urease test (RUT), the doctor&#x02019;s test, is also challenged because the presence of other urease producing bacteria in the stomach cannot be denied. Moreover, RUT has been reported with poor sensitivity specially, when density of the bacterium is low. Isolation of H. pylori is essential to investigate its growth requirements, antibiotic susceptibility testing, studying virulence factor to develop vaccine and many more explorations. It has also got several disadvantages i.e., special condition for transporting, media, incubation and few days waiting for the colonies to appear, apart from the speed essentially needed to process the specimens. Till date, majority of the microbiological laboratories in the world are not equipped and trained to isolate such fastidious bacterium. The option left is PCR methods to detect H. pylori&#x02019;s DNA in gastric mucosa, gastric juice, saliva, dental plaques 展开更多
关键词 Helicobacter pylori review Invasive tests Non-invasive tests Gold standard Polymerase chain reaction detection Nested polymerase chain reaction
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电动轮驱动电动汽车差速技术研究 被引量:31
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作者 靳立强 王庆年 +1 位作者 张缓缓 王军年 《汽车工程》 EI CSCD 北大核心 2007年第8期700-704,共5页
提出了电动轮旋转动力学方程和对驱动电机采用转矩指令控制及车轮转速随动的方法,实现电动轮系统的自适应差速。进行了转向行驶、路面不平及不同车轮半径等工况的道路试验,试验结果表明:电动轮汽车在各种工况下都能保持良好的差速性能,... 提出了电动轮旋转动力学方程和对驱动电机采用转矩指令控制及车轮转速随动的方法,实现电动轮系统的自适应差速。进行了转向行驶、路面不平及不同车轮半径等工况的道路试验,试验结果表明:电动轮汽车在各种工况下都能保持良好的差速性能,具有自适应差速特性。 展开更多
关键词 电动轮驱动 电子差速 自适应差速 试验
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液舱流体晃荡的模型试验 被引量:25
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作者 王德禹 金咸定 李龙渊 《上海交通大学学报》 EI CAS CSCD 北大核心 1998年第11期114-117,共4页
液舱晃荡问题是近年来液货船设计中十分关注的课题之一,它涉及到自由液面的大幅度运动等一系列非线性问题,因此在理论上具有较大的难度,试验研究显得至关重要.文中对已有针对船舶与海洋工程领域的典型液舱晃荡模拟试验进行了简要的... 液舱晃荡问题是近年来液货船设计中十分关注的课题之一,它涉及到自由液面的大幅度运动等一系列非线性问题,因此在理论上具有较大的难度,试验研究显得至关重要.文中对已有针对船舶与海洋工程领域的典型液舱晃荡模拟试验进行了简要的总结,并提出了今后应考虑的几个问题. 展开更多
关键词 船舶结构 波舱 晃荡 模型试验 液货船 设计
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宁波海相软土工程特性研究 被引量:29
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作者 王文军 刘用海 朱向荣 《工程勘察》 CSCD 北大核心 2008年第10期19-24,共6页
根据宁波地区120余项实际工程的勘察资料,从地质成因、颗粒级配、矿物成分、土性指标、微观结构及结构性等方面系统分析了宁波海相软土的工程特性,并与我国沿海典型软土进行了比较。选取宁波地区典型软土,通过室内试验,从内因和外因两... 根据宁波地区120余项实际工程的勘察资料,从地质成因、颗粒级配、矿物成分、土性指标、微观结构及结构性等方面系统分析了宁波海相软土的工程特性,并与我国沿海典型软土进行了比较。选取宁波地区典型软土,通过室内试验,从内因和外因两方面分析研究了含水量、干密度、围压、应力路径、排水条件以及剪切速率等因素对应力应变曲线的影响。宁波海相软土工程特性研究对该区今后的工程建设具有实际意义。 展开更多
关键词 宁波 海相软土 工程特性 应力应变关系 试验
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HRB400级钢筋混凝土短柱抗震试验研究 被引量:31
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作者 王全凤 沈章春 +2 位作者 杨勇新 黄奕辉 曾志兴 《建筑结构学报》 EI CAS CSCD 北大核心 2008年第2期114-117,共4页
通过对HRB400级钢筋混凝土短柱在水平反复荷载作用下的抗震试验研究,分析了HRB400级钢筋和C60,C70,C80高强混凝土匹配下的配箍率为0.269%、剪跨比为1.9的混凝土短柱破坏形态、滞回特性,并将试验得到的承载力与采用现行规范公式计算结果... 通过对HRB400级钢筋混凝土短柱在水平反复荷载作用下的抗震试验研究,分析了HRB400级钢筋和C60,C70,C80高强混凝土匹配下的配箍率为0.269%、剪跨比为1.9的混凝土短柱破坏形态、滞回特性,并将试验得到的承载力与采用现行规范公式计算结果进行了比较。研究结果表明:试验柱承载力随混凝土强度的增大而增大;试验柱在水平反复荷载作用下发生的都是脆性的剪切破坏,延性极差;采用现行规范计算HRB400级钢筋混凝土短柱的受剪承载力过于保守。 展开更多
关键词 高强混凝土 短柱 试验研究 延性 抗震性能
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