期刊文献+
共找到2篇文章
< 1 >
每页显示 20 50 100
用于滑转率控制的拖拉机机组瞬态阻力模拟器
1
作者 张宾 余群 《中国农业大学学报》 CAS CSCD 北大核心 1997年第2期51-54,共4页
在室内土槽台车上,研制了用于滑转率控制实验的拖拉机机组瞬态阻力模拟器,利用磁粉制动器作为施力装置。它可以替代拖拉机机组中的犁和电液伺服系统,既能模拟机组静态阻力和阻力扰动,又能模拟犁调节过程中的阻力变化,加载迅速,调... 在室内土槽台车上,研制了用于滑转率控制实验的拖拉机机组瞬态阻力模拟器,利用磁粉制动器作为施力装置。它可以替代拖拉机机组中的犁和电液伺服系统,既能模拟机组静态阻力和阻力扰动,又能模拟犁调节过程中的阻力变化,加载迅速,调节中力的变化以相应的犁调节电液系统的简化数学模型为理论基础,适于对多种机型的模拟。这为研究滑转率控制系统的特征、寻求最佳控制算法提供了必要的实验手段。 展开更多
关键词 拖拉机 清转率 阻力模拟 磁粉制动器
下载PDF
Iron homeostasis and H63D mutations in alcoholics with and without liver disease 被引量:3
2
作者 Mariana Verdelho Machado Paula Ravasco +3 位作者 Alexandra Martins Maria Rosário Almeida Maria Ermelinda Camilo Helena Cortez-Pinto 《World Journal of Gastroenterology》 SCIE CAS CSCD 2009年第1期106-111,共6页
MM: To evaluate the prevalence of HFE gene mutation and indices of disturbed iron homeostasis in alcoholics with and without liver disease. METHODS: One hundred and fifty-three heavy drinkers (defined as alcohol co... MM: To evaluate the prevalence of HFE gene mutation and indices of disturbed iron homeostasis in alcoholics with and without liver disease. METHODS: One hundred and fifty-three heavy drinkers (defined as alcohol consumption 〉 80 g/d for at least 5 years) were included in the study. These comprised 78 patients with liver disease [liver disease alcoholics (LDA)] in whom the presence of liver disease was confirmed by liver biopsy or clinical evidence of hepatic decompensation, and 75 subjects with no evidence of liver disease, determined by normal liver tests on two occasions [non-liver disease alcoholics (NLDA)], were consecutively enrolled. Serum markers of iron status and HFE C282Y and H63D mutations were determined. HFE genotyping was compared with data obtained in healthy blood donors from the same geographical area. RESULTS: Gender ratio was similar in both study groups. LDA patients were older than NLDA patients (52 ± 10 years vs 48 ± 11 years, P = 0.03). One third and one fifth of the study population had serum transferrin saturation (TS) greater than 45% and 60% respectively. Serum iron levels were similar in both groups. However, LDA patients had higher TS (51 ± 27 vs 36 ± 13, P 〈 0.001) and ferritin levels (559 ± 607 ng/mL vs 159 ± 122 ng/mL, P 〈 0.001), and lower total iron binding capacity (TIBC) (241 ± 88 μg/dL vs 279 ± 40 μg/dL, P = 0.001). The odds ratio for having liver disease with TS greater than 45% was 2.20 (95% confidence interval (CI): 1.37-3.54). There was no difference in C282Y allelic frequency between the two groups. However, H63D was more frequent in LDA patients (0.25 vs 0.16, P = 0.03). LDA patients had a greater probability of carrying at least one HFE mutation than NLDA patients (49.5% vs 31.6%, P = 0.02). The odds ratio for LDA in patients with H63D mutation was 1.57 (95% CI: 1.02-2.40). CONCLUSION: The present study confirms the presence of iron overload in alcoholics, which was more severe in the subset of subjects with liver disease, in parallel with an increased frequency of H63D HFE mutation. 展开更多
关键词 Alcoholic liver disease Iron lIFE gene H63D HEMOCHROMATOSIS
下载PDF
上一页 1 下一页 到第
使用帮助 返回顶部