首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   82篇
  免费   3篇
  国内免费   1篇
耳鼻咽喉   1篇
儿科学   3篇
妇产科学   2篇
基础医学   11篇
口腔科学   2篇
临床医学   10篇
内科学   24篇
皮肤病学   2篇
特种医学   5篇
外科学   19篇
预防医学   3篇
眼科学   1篇
药学   3篇
  2022年   1篇
  2021年   2篇
  2020年   1篇
  2019年   1篇
  2018年   5篇
  2017年   6篇
  2016年   4篇
  2015年   1篇
  2014年   5篇
  2013年   6篇
  2012年   3篇
  2011年   5篇
  2010年   4篇
  2009年   3篇
  2008年   3篇
  2007年   5篇
  2006年   2篇
  2005年   2篇
  2004年   2篇
  2003年   2篇
  2002年   7篇
  2001年   1篇
  1998年   2篇
  1997年   2篇
  1995年   1篇
  1993年   1篇
  1992年   1篇
  1990年   1篇
  1989年   1篇
  1986年   1篇
  1978年   2篇
  1976年   1篇
  1955年   1篇
  1954年   1篇
排序方式: 共有86条查询结果,搜索用时 15 毫秒
1.
We investigated the effects of 12‐hour shift work for five to seven consecutive days and overtime on the prevalence of severe sleepiness in the automobile industry in Korea. [Correction added after online publication 28 Nov: Opening sentence of the summary has been rephrased for better clarity.] A total of 288 randomly selected male workers from two automobile factories were selected and investigated using questionnaires and sleep‐wake diaries in South Korea. The prevalence of severe sleepiness at work [i.e. Karolinska Sleepiness Scale (KSS) score of 7 or higher] was modeled using marginal logistic regression and included theoretical risk factors related to working hours and potential confounding factors related to socio‐economic status, work demands, and health behaviors. Factors related to working hours increased the risk for severe sleepiness at the end of the shift in the following order: the night shift [odds ratio (OR): 4.7; 95% confidence interval (CI): 3.6–6.0)], daily overtime (OR: 2.2; 95% CI: 1.7–2.9), weekly overtime (OR: 1.6; 95% CI: 1.0–2.6), and night overtime (OR: 1.6; 95% CI: 0.8–3.0). Long working hours and shift work had a significant interactive effect for severe sleepiness at work. Night shift workers who worked for 12 h or more a day were exposed to a risk of severe sleepiness that was 7.5 times greater than day shift workers who worked less than 11 h. Night shifts and long working hours were the main risk factors for severe sleepiness among automobile factory workers in Korea. Night shifts and long working hours have a high degree of interactive effects resulting in severe sleepiness at work, which highlight the need for immediate measures to address these characteristics among South Korean labor force patterns.  相似文献   
2.
3.
4.
Chest trauma in children.   总被引:3,自引:0,他引:3  
OBJECTIVES: Chest trauma in childhood is uncommon in clinical practice. The management and treatment principles of children with thoracic trauma were discussed with the data reported in the literature. METHODS: Of the chest injury diagnosed in 1653 patients, 225 were children in the last 17-year period. There were 199 boys (88.44%) and 26 girls (11.55%). The most common causes were blunt injuries in 135 cases (60%), stab wounds in 67 cases (29.77%) and gunshot wounds in 22 cases (9.77%). RESULTS: Out of 225, 217 patients were treated conservatively and eight patients were treated surgically. There was no mortality and morbidity. CONCLUSIONS: The prevalence of chest trauma in children due to blunt injuries is high in Turkey. Extremity injury is thought to be the most commonly associated extra-thoracic injury. However, thoracic trauma in children can be managed conservatively in most of the cases.  相似文献   
5.
OBJECTIVES: To compare the clinical features and the surgical approaches between single pulmonary (SPH) and hepatopulmonary hydatidosis (HPH). METHODS: The hospital and follow-up records of 141 patients who had undergone surgery for pulmonary hydatidosis in our clinic between January 1991 and January 2001 were reviewed. Forty-nine patients (34.8%) had concomitant liver cysts in addition to the pulmonary cysts and they were regarded as HPH (Group I). The remaining 92 (65.2%) patients had SPH (Group II). Both groups were compared according to their clinical, radiological and surgical features. RESULTS: Seventeen (34.7%) male and 32 (65.3%) female patients had HPH. The mean age of the patients with HPH was significantly higher than the age of those with SPH (P<0.05) and the frequency of hepatopulmonary localization, which is contrary to single pulmonary cyst, was significantly higher in females (P<0.05). The majority (67.3%) of the cysts located in the liver were solitary. Multiple pulmonary cysts were in higher ratio in Group II, compared to Group I (45.7 vs. 22.8%) and bilateral pulmonary cyst ratio was higher in Group II, as well (26.5 vs. 13%) (P<0.05). In 14 patients (28.6%), the concomitant cysts localized in the dome of liver were extirpated via right thoracophrenotomy, and in one of them sternophrenotomy was performed. There was no statistically significant difference associated with the postoperative complications and hospital stay between groups. No recurrence and mortality were recorded in Group II. CONCLUSIONS: Multi-organ localizations (especially liver) should be examined in all patients with pulmonary hydatid cysts. HPH is more frequent in female patients over 40 years of age. The pulmonary cysts in HPH show a tendency to be bilateral and multiple. HPH should be regarded as a different entity since it can cause either economic or labour loss due to the multi-operations and prolonged postoperative care. The operative strategy and approach should be different in hepatopulmonary cysts especially if they locate in the right or bilateral lung. One-session operation with the improvements of its techniques and methods should be considered in selected cases.  相似文献   
6.
Summary. Sixty human premolar and canine teeth were used in this study. Class V cavities were prepared with a turbine handpiece. The experimental material was ASPA, with silicate cement and zinc oxide-eugenol cements being used as controls. The teeth were extracted approximately 4 days, 30 days or 90 days after insertion of the filling material. They were demineralized and prepared for histological examination. The test procedure and evaluation closely followed recommendations by the FDI (1980). The reaction at the short time interval for each material was similar, while at the intermediate and long periods silicate cement caused the most inflammation, zinc oxideeugenol cement the least, and ASPA an intermediate response. The reaction to ASPA was reduced at the long period compared with the intermediate period.  相似文献   
7.
星形胶质细胞在突触形成中发挥重要作用,但星形胶质细胞突起如何在发育过程中与突触结构相联系还不是很清楚。本文分析在小脑突触发生过程中Bergmann胶质细胞(BG)突起生长的类型。本文发现在这个过程中,BG突起向外生长与树突棘增多的包被作用相关。此外,双光子时间分辩显像显示BG突起是高度动态的,在棘包被过程中突起趋于稳定。虽然突触活力依赖于肌动蛋白的聚合作用,但细胞骨架调节器Rac1和RhoG的活动在胶质细胞突起的动力或密度上并未发挥作用,而是对于保持突起长度起关键性作用。本文扩展这个发现,探查突起形态和包被之间的关系,发现缩短的突起导致棘覆盖的减少。本文进一步发现在BG表达dn-Rac1和低水平突触包被的区域,显示突触数量的增加。这些分析提示BG突起如何生长并包围突触结构,阐明BG突起结构对突触包被适当发育的重要性,并提示包被在突触形成中的作用。  相似文献   
8.
A school-based study was implemented to assess the family history of coronary heart disease (CHD) and hyperlipidemia (HL) in relation to serum lipoprotein and apolipoprotein levels. One hundred and twenty-five elementary school students (aged9–10 years) and 297 junior high school students (aged12–13 years) participated. Family history was evaluated by the following scoring method: positive family history in a parent. 2 points: in a grandparent. 1 point: and onset of CHD before age 60, 1 additional point. Family history of HL was positive in 8.2% of elementary school students, and 4.2% in junior high school students. Family history of CHD was positive in 11.5% of elementary students, and 11.0% in junior students. Family history score (FHS) for HL was related to serum total cholesterol (TC), low density lipoprotein cholesterol (LDLC), high density lipoprotein cholesterol, apolipoprotein A-T, apolipoprotein B (apoB) and lipoprotein (a) in elementary students, and to TC, LDLC, triglyceride and apoB in junior students. There was no relationship between FHS for CHD and serum lipoprotein or apolipoprotein levels in any student. The children with a positive FH of HL already demonstrated an atherogenic lipid profile while those with FH of CHD did not. which was probably because lipid profiles in children are more genetically mediated by a FH of HL than of CHD.  相似文献   
9.

Background

Pulmonary hypertension (PH) caused by chronic obstructive lung disease (COLD) essentially involves the right heart. Also left ventricular (LV) systolic and diastolic functions may be affected.

Objectives

The aim of this study was to investigate the effect of on LV diastolic function in patients with COLD.

Methods

A total of 47 patients with COLD and 20 controls were included in this study. All patients underwent Doppler echocardiography, tissue Doppler imaging examinations and right cardiac catheterization. The patients were divided into 2 subgroups according to mean pulmonary arterial pressure (mPAP): patients without PH (group1, n = 25) and with PH (group 2, n = 22). The following measurements were taken: peak velocity of early diastolic filling (E), peak late filling with atrial contraction (A), E/A ratio, deceleration time (DT) of E, isovolumic relaxation time (IVRT), early (Em) and late (Am) diastolic mitral lateral annulus velocity.

Results

Mitral E/A < 1 and Em < 8 cm/sec were higher in group 2 than in group 1 and the control group. There were significant correlations between mPAP and both mitral E/A (r:? 0.60) and Em (r:? 0.45). In multivariate model, mPAP was not found to be significant on mitral E/A ratio < 1, but there was a significant effect on mitral Em < 8 cm/sec (odds ratio [OR]:1.14, P < 0.05).

Conclusion

This study shows that LV diastolic dysfunction in COLD is closely correlated to PH levels. Although increased mPAP may affect the mitral E/A ratio, it seems to have no effect on mitral E/A < 1, whereas it has an independent effect on Em < 8 cm/sec. Copyright © 2010 Wiley Periodicals, Inc.
  相似文献   
10.
There is controversial data regarding the relationship between uric acid (UA) and coronary artery disease and cardiovascular events. Despite the deleterious effects of hyperuricemia on endothelial function, the effect of UA on myocardial ischemia has not been previously studied. We aimed to investigate the relationship between UA and myocardial ischemia that was identified using dobutamine stress echocardiography (DSE). In this retrospective study, the laboratory and DSE reports of 548 patients were reviewed. The patients were divided into two groups based on the presence of ischemia and further subdivided into three groups according to the extent of ischemia (none, ischemia in 1–3 segments, ischemia in >3 segments). Serum UA levels were compared. Determinants of ischemia were assessed using a regression model. UA was increased in patients with ischemia and was correlated with the number of ischemic segments (p < 0.001). A cutoff value of UA > 5 mg/dl had 63.9 % sensitivity, 62.0 % specificity, 42.5 % positive predictive value (PPV), and 79.6 % negative predictive value for ischemia. When the positive DSE exams were further sorted according to the UA cutoff, the PPV of DSE increased from 80.2 to 94.0 %. Uric acid (odds ratio 1.51; 95 % CI 1.14–1.99), diabetes mellitus, HDL and glomerular filtration rate were found to be independent determinants of myocardial ischemia in DSE. Increased UA is associated with both the presence and extent of DSE-identified myocardial ischemia. A UA cutoff may be a good method to improve the PPV of DSE.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号