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排序方式: 共有105条查询结果,搜索用时 15 毫秒
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BACKGROUND: Although transmission of hepatitis C virus (HCV) through parental exposure is well documented, it is still controversial whether familial clustering of HCV occurs. METHODS: To investigate risk factors for HCV infection, 109 cases and 84 non-infected controls were studied. In addition, 250 family members (104 men, 146 women) of cases and 170 family members of controls (64 men, 106 women) were tested for HCV infection using an anti-HCV antibody, alanine aminotransferase (ALT), and reverse transcribed polymerase chain reaction (RT-PCR). RESULTS: In the case-control analysis, people aged > or =60 were almost three times more likely to be infected by HCV than those aged <40. Risk of HCV infection was most strongly related to a history of blood transfusion (OR = 12.6, 95% CI: 4.3-36.5) followed by a history of jaundice (OR = 4.1, 95% CI: 1.3-12.6). Only one family member of cases and no-one related to the controls had HCV infection. CONCLUSIONS: These results suggest that, in Korea, age and parenteral exposure, such as a blood transfusion, are risk factors for HCV infection and familial clustering of HCV infection, if it occurs, is rare. 相似文献
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基于PLC的瓷砖平整度在线检测系统研究 总被引:2,自引:0,他引:2
为实现瓷砖平整度的自动在线检测及分级,设计了基于PLC、组态软件和激光位移传感器的瓷砖平整度实时检测分级系统。系统由传送、检测和分级三部分组成。该检测系统采用光学三角法检测技术,通过编码器及PLC的高速计数器功能对移动中的待检测瓷砖的采样位置进行精确定位,使用激光位移传感器对瓷砖表面进行信息采集,经AD转换后在PLC内部按照特定的算法进行平整度运算,以PLC为核心实现瓷砖的分级处理和对设备的整体控制。实验表明该检测系统高效、稳定、可靠。瓷砖平整度检测精度为±0.1 mm,多次同方向检测精度为±0.05 mm,检测速度为每分钟40片,检测准确度可达到95%以上,适用于当前瓷砖生产过程的质量控制。 相似文献
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Eun-Bi Choi Taiwo Samuel Agidigbi In-Soon Kang Chaekyun Kim 《International journal of molecular sciences》2022,23(21)
Bone absorption is necessary for the maintenance of bone homeostasis. An osteoclast (OC) is a monocyte–macrophage lineage cell that absorbs bone tissue. Extracellular signal-regulated kinases (ERKs) are known to play important roles in regulating OC growth and differentiation. In this study, we examined specific downstream signal pathways affected by ERK inhibition during OC differentiation. Our results showed that the ERK inhibitors PD98059 and U0126 increased receptor activator of NF-κB ligand (RANKL)-induced OC differentiation in RAW 264.7 cells, implying a negative role in OC differentiation. This is supported by the effect of ERK2-specific small interfering RNA on increasing OC differentiation. In contrast to our findings regarding the RAW 264.7 cells, the ERK inhibitors attenuated the differentiation of bone marrow-derived cells into OCs. The ERK inhibitors significantly increased the phosphorylation of adenosine 5′-monophosphate-activated protein kinase (AMPK) but not the activation of p38 MAPK, Lyn, and mTOR. In addition, while the ERK inhibition increased the expression of the RANKL receptor RANK, it decreased the expression of negative mediators of OC differentiation, such as interferon regulatory factor-8, B-cell lymphoma 6, and interferon-γ. These dichotomous effects of ERK inhibition suggest that while ERKs may play positive roles in bone marrow-derived cells, ERKs may also play negative regulatory roles in RAW 264.7 cells. These data provide important information for drug development utilizing ERK inhibitors in OC-related disease treatment. 相似文献
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余桂东 《昆明理工大学学报(自然科学版)》2008,33(2):118-121
本文首先给出集[1,n]上k-次幂等映射的概念,用置换群的循环分解给出集[1,n]上k-次幂等映射的计数公式,接着定义了连象映射和保小映射,不但得到它们的计数公式,还得到一个第2类斯特林数的关系式及保小映射总数指母函数系数的变化趋势,最后给出交错映射及上下置换的概念并给出关于上下置换指母函数简明表达式的一个简单证明. 相似文献
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Ibironke A Ajayi Rotimi A Oderinde Victor O Taiwo Emmanuel O Agbedana 《Journal of the science of food and agriculture》2004,84(13):1715-1721
The nutritional value of Telfairia occidentalis seed and seed oil available in local market was studied in rats. The average values of the proximate analysis on dry matter basis were 203 g kg?1 crude protein, 536.3 g kg?1 fat, 39 g kg?1 ash, 95 g kg?1 crude fibre and 43.7 g kg?1 carbohydrate, while the moisture content was 75 g kg?1. The mineral analyses showed that T occidentalis seeds contain potassium (3280 mg kg?1), sodium (1230 mg kg?1), magnesium (60.8 mg kg?1), calcium (60.8 mg kg?1) and iron (13.0 mg kg?1). The oil extracted from the seed sample showed physicochemical properties that suggest its suitability for edible and industrial uses. The oil contained high levels of unsaturated fatty acids, oleic and linoleic, which accounted for 63.22% of total fatty acids recovered, while palmitic acid (27.4% of the oil by weight) was the most prevalent saturated fatty acid in the oil. No trace of eleostearic acid was detected in the oil. The effect on physical appearance, weight gain, organ weight, tissue and plasma cholesterol and triacylglycerol levels was determined in rats fed a diet containing 5% T occidentalis oil. These were compared with those of rats fed a control diet (0% T occidentalis oil) over an 8 week study period. Weekly monitoring of the rats showed good physical appearance and steady weight increase. The test rats were not anaemic and no mortality was recorded. While there was a significantly higher (p < 0.05) level of cholesterol in the heart of test rats compared with the control, there was a significantly lower (p < 0.05) plasma cholesterol level, suggesting that T occidentalis seed oil can be used to lower plasma levels of cholesterol. Histological examination of the sections of the heart, liver, kidney and spleen of the test rats revealed varying degrees of pathology. These include artherosclerotic changes in the walls of vasa vasori and lymphatics in the heart and hyaline degeneration of myofibrils, fatty infiltration of hepatocytes, and glomerular and tubular degeneration in the kidneys. These lesions may have been due to the effect of fatty acids, especially erucic acid, in the seed oil, which at 1.24% (less that the 5% conventional allowable limit for edible oils) may be intolerable for rats and may be unsuitable for human consumption. The seed oil may be used for industrial purposes such as soap making, lubrication and cosmetics for which it is well suited. Copyright © 2004 Society of Chemical Industry 相似文献
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G. Aliberti G. Palmiotti M. Salvatores T.K. Kim T.A. Taiwo M. Anitescu I. Kodeli E. Sartori J.C. Bosq J. Tommasi 《Annals of Nuclear Energy》2006
A sensitivity and uncertainty study has been performed to evaluate the impact of neutron cross-section uncertainty on the most significant integral parameters related to the core and fuel cycle. This work is a contribution to the feasibility assessment of innovative reactor and fuel cycle systems, proposed within the Generation IV initiative. Results of an extensive analysis indicate the most relevant parameters and show any potential significant problems arising from the quality of existing nuclear data, in the assessment of the systems considered. In order to perform these studies, uncertainty covariance data have been produced, mostly based on selected, high accuracy integral experiments. A target accuracy assessment has been also performed in order to evaluate nuclear data improvement requirements. The results of the assessment allows to give guidelines in order to define the most appropriate and effective strategy for data uncertainty reduction. 相似文献
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Many patients with chronic posttraumatic stress disorder (PTSD) suffer from comorbid major depression. The present study examines the responsiveness of such dual-diagnosis patients to antidepressant medication. Subjects were enrolled in the PTSD medication clinic at the San Diego Veterans Affairs Medical Center. Inclusion criteria were current diagnoses of PTSD and major depression, at least 6 months of regular participation in the clinic, and treatment with antidepressant medication at therapeutic levels and durations. Exclusion criteria were current drug or alcohol abuse, primary psychotic illness, and poor compliance or frequent missed appointments. Among 72 patients meeting inclusion and exclusion criteria, 50% were estimated to be substantially improved, on the basis of Clinical Global Evaluation (CGE) scores of 2 or 1, after remaining on the same antidepressant treatment regimen at therapeutic doses for at least 1 month. Antidepressant medications affecting predominantly serotonin reuptake (sertraline, fluoxetine) were associated with better outcomes than antidepressants affecting predominantly norepinephrine reuptake (nortriptyline, desipramine). 相似文献