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   261篇
  免费   10篇
儿科学   28篇
妇产科学   15篇
基础医学   26篇
口腔科学   1篇
临床医学   49篇
内科学   67篇
皮肤病学   8篇
神经病学   6篇
特种医学   2篇
外科学   16篇
预防医学   15篇
药学   35篇
中国医学   1篇
肿瘤学   2篇
  2020年   2篇
  2017年   2篇
  2016年   4篇
  2015年   1篇
  2014年   1篇
  2013年   2篇
  2012年   15篇
  2011年   13篇
  2010年   5篇
  2009年   4篇
  2008年   14篇
  2007年   10篇
  2006年   13篇
  2005年   10篇
  2004年   15篇
  2003年   10篇
  2002年   14篇
  2001年   13篇
  2000年   12篇
  1999年   7篇
  1998年   2篇
  1997年   5篇
  1996年   3篇
  1995年   3篇
  1994年   1篇
  1993年   1篇
  1992年   10篇
  1991年   5篇
  1990年   7篇
  1989年   6篇
  1988年   3篇
  1987年   5篇
  1986年   5篇
  1985年   7篇
  1984年   1篇
  1982年   3篇
  1981年   2篇
  1980年   3篇
  1979年   7篇
  1978年   3篇
  1977年   4篇
  1976年   4篇
  1975年   1篇
  1974年   1篇
  1973年   1篇
  1972年   1篇
  1971年   2篇
  1970年   1篇
  1968年   1篇
  1966年   2篇
排序方式: 共有271条查询结果,搜索用时 15 毫秒
1.
Background:Cardiovascular diseases (CVD), particularly the ischemic heart disease, are a growing public health issue. In addition, the return to work after an acute cardiovascular attack represents a complex challenge.Objectives:To evaluate utility and safety of cardiopulmonary exercise testing (CPET), particularly performed “on site”, to promote a return to work in line with the residual working capacity.Methods:Fifty-nine workers affected by a major cardiovascular event, aged 18-63 years, have been enrolled between 2015 and 2018. All the patients underwent a CPET in outpatient clinic. Eleven workers also underwent the “on site” CPET, recorded during their working activities.Results:Outpatient clinic CPET outcomes (i.e. normal, mild impairment or moderate/severe impairment of cardiopulmonary function) were associated with the subjective perception of workers’ health status after returning to work. The “on site” CPET was found to be safe and reliable to promote a personalized return to work of patients. In 7 out of 11 patients, the values of O2 consumption (VO2) during the working activity were higher than 40% of VO2 max as obtained from laboratory CPET.Conclusions:This study provides evidence for safety and usefulness of “on site” CPET for a personalized statement of fitness for work. This may facilitate the job retention of patients characterized by a high risk of unnecessary job loss. The use of CPET represents a first step of energy expenditure evaluation associated with specific working tasks.Key words: Acute coronary syndrome, cardiopulmonary exercise testing, return to work  相似文献   
2.
3.
Prostaglandins (PG) have been suggested to play a role in the genesis of cough induced by angiotensin-converting enzyme inhibitors (ACE-I) and that inhibition of PG synthesis can reduce or abolish the incidence of this side effect. Moreover, experimental and clinical data suggest that nifedipine, a dihydropyridine Ca antagonist, can inhibit PG synthesis. Therefore, we wished to determine whether nifedipine can reduce cough induced by ACE-I as compared with indomethacin, a known inhibitor of PG synthesis. Fourteen hypertensive patients who developed cough during captopril chronic therapy randomly received slow-release nifedipine 20 mg twice daily (b.i.d.), indomethacin 50 mg b.i.d., and placebo b.i.d. for 1 week in a double-blind, cross-over design. At the end of each treatment phase, cough was evaluated by a self-administered questionnaire containing an ordinal scale for daily cough intensity and frequency. Indomethacin abolished or markedly reduced cough induced by ACE-I, whereas nifedipine reduced it but to a lesser degree. These findings suggest that PG can play a role in cough caused by ACE-I, and a dihydropyridine Ca antagonist can reduce the occurrence of this side effect.  相似文献   
4.
Results obtained measuring blood Cyclosporine A (CsA) concentrations in transplanted patients (124 samples of cardiac, 20 samples of liver, and 10 samples of kidney transplanted patients) by the use of two monoclonal radioimmunoassay (RIA) methods have been compared with those found using the HPLC technique (considered as the reference method) and two polyclonal RIAs. In addition, results on quality control samples collected in a multicentre collaborative study for CsA assay from the users of the same monoclonal and polyclonal RIAs were analysed to evaluate the performance of the methods under study. Polyclonal RIAs, which measure both the parent molecule and its metabolites, produced results 1.5-3 times higher than HPLC or monoclonal RIAs. On the contrary the two RIAs, which use monoclonal antibodies specific for CsA, show a better correlation with HPLC; these RIAs, which measure the intact drug molecule only, are recommended when the monitoring of the native molecule of CsA is requested. As far as the reproducibility is concerned, the four RIAs (both polyclonal and monoclonal) exhibit an unsatisfactory degree of between-assay and between-lab precision, since the coefficients of variation (CVs) ranged from 19.4% to 23.1%.  相似文献   
5.
The intestinal ecosystem in chronic functional constipation   总被引:3,自引:0,他引:3  
Chronic functional constipation is common in infants, and the bacterial composition of stools in this condition is not known. The study aims were to: (i) investigate the composition of the intestinal ecosystem in chronic functional constipation; (ii) establish whether the addition of the water-holding agent calcium polycarbophil to the diet induces an improvement in constipation; and (iii) determine the composition of the intestinal ecosystem after the use of this agent. In total, 42 children (20F, 22M; mean age: 8.6±2.9y) were studied. Twenty-eight children with functional chronic constipation without anatomical disorders were treated double-blind in random sequence for 1 month with an oral preparation of calcium polycarbophil (0.62g /twice daily) or placebo. Intestinal flora composition was evaluated by standard microbiological methods and biochemical assays on faecal samples collected before and after treatment. Fourteen healthy children were studied as controls. The results show that (i) the constipated children presented a significant increase in clostridia and bifidobacteria in faeces compared to healthy subjects-different species of clostridia and enterobacteriaceae were frequently isolated; no generalized overgrowth was observed; Clostridia outnumbered bacteroides and E. coli mean counts by 2-3log, while bacteroides and E. coli counts were similar (5-6 log10/g fresh faeces); these intestinal disturbances could be defined as a dysbiosis, i.e. a quantitative alteration in the relative proportions of certain intestinal bacterial species. (ii) Clinical resolution of constipation was achieved only in 43% of treated children and an improvement in 21% (one bowel movement every 2 d). (iii) Calcium polycarbophil treatment induced no significant changes in the composition of the intestinal ecosystem, nor in blood chemistry parameters.  相似文献   
6.
7.
Serum testosterone levels and arterial blood pressure in the elderly.   总被引:2,自引:0,他引:2  
The aim of this study was to evaluate the relationship between serum testosterone levels and arterial blood pressure (BP) in the elderly. We studied 356 non-diabetic, non-smoking, non-obese men aged 60 to 80 years and untreated for hypertension. All subjects were evaluated in the morning after an overnight fast. Evaluation included measurements of the following: BP (by mercury sphygmomanometer, Korotkoff I and V), body weight, height and free testosterone (T) plasma levels (by radioimmunoassay). According to the BP values, the subjects were classified as normotensives (NT; n=112; SBP/DBP<140/90 mmHg), systolic and diastolic hypertensives (HT; n=127; SBP/DBP>140/90 mmHg), and isolated systolic hypertensives (ISH; n=117; SBP>140 mmHg and DBP<90 mmHg). T values decreased with increasing age in all 3 groups and was significantly lower in HT (-15%) and ISH men (-21%) than in NT men (p<0.05). In each group, the T levels showed a highly significant negative correlation with BMI (p<0.001). A significant negative correlation was also found between T levels and SBP in NT (r=-0.35, p<0.001), ISH (r=-0.67, p<0.001), and HT (r=-0.19, p<0.05) men, whereas a negative correlation with DBP was observed only in the NT men (r=-0.19, p<0.05). Adjusting for the BMI confirmed a significant difference in plasma T levels between ISH and NT men, but not between HT and NT men. Multiple regression analysis employing BP as a dependent variable confirmed a strong relationship between T levels and SBP in all 3 groups, whereas a significant relationship between T levels and DBP was found only in NT men. In conclusion, although further studies are needed to clarify the relationship between plasma T levels and BP, our findings suggest that in elderly men with ISH, the reduced plasma levels of testosterone might contribute to the increased arterial stiffness typical of these subjects.  相似文献   
8.
9.
We describe the first cases, to our knowledge, of C9 deficiency in Europe that were detected in a Swiss family, of which two members--one with a complete deficiency and the other with approximately half-normal C9 levels--experienced bacterial meningitis. The index patient, a 56-year-old white man with a history of purulent meningitis at the age of 23 years, presented with an acute meningococcal meningitis. No impairment of cellular immunity or immunoglobulin deficiency could be found. Complement assays showed a complete deficiency of the C9 component, while the other individual component levels were normal and the hemolytic activity (measured using the CH50 assay) was only slightly reduced. A family study revealed complete C9 deficiency in the patient's healthy brother and half-normal C9 concentrations in his sister, his son (who also had experienced an episode of bacterial meningitis), and his niece, consistent with an inherited C9 deficiency. This first case of recurrent meningitis in a white patient with complete C9 deficiency suggests that this complement defect may also be a risk factor for bacterial, especially neisserial, infections.  相似文献   
10.
Individuals with androgen resistance encompass a spectrum of phenotypic abnormalities ranging from complete testicular feminization to undervirilized men. Such subjects have been classified according to the hormone-binding characteristics in genital skin fibroblasts and on the basis of the mutation in the androgen receptor (AR) gene. Antibodies to the amino-terminal region of the human AR were used to develop an immunoblot assay for the comparison of androgen binding with the amount of AR expressed in genital skin fibroblasts. In controls and 4 androgen-resistant subjects with DNA-binding domain mutations, levels of immunoreactive AR correlated closely with androgen-binding capacity. In 15 androgen-resistant subjects with qualitatively abnormal AR, immunoreactive AR levels tended to be higher than predicted from the ligand-binding capacity. Discordance between immunoreactivity and androgen binding also occurred in fibroblasts from 3 other subjects. One carries a stop codon in the AR gene and produces a truncated AR that is immunoreactive but does not bind androgen. Two carry single point mutations in the hormone-binding domain and produce immunoreactive AR that is normal in size but does not bind androgen.  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