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   3223篇
  免费   219篇
  国内免费   17篇
耳鼻咽喉   41篇
儿科学   89篇
妇产科学   62篇
基础医学   371篇
口腔科学   108篇
临床医学   484篇
内科学   915篇
皮肤病学   55篇
神经病学   142篇
特种医学   221篇
外国民族医学   2篇
外科学   329篇
综合类   49篇
一般理论   5篇
预防医学   269篇
眼科学   26篇
药学   106篇
肿瘤学   185篇
  2021年   35篇
  2019年   38篇
  2018年   58篇
  2017年   35篇
  2016年   42篇
  2015年   48篇
  2014年   56篇
  2013年   88篇
  2012年   108篇
  2011年   141篇
  2010年   98篇
  2009年   108篇
  2008年   139篇
  2007年   183篇
  2006年   148篇
  2005年   136篇
  2004年   126篇
  2003年   110篇
  2002年   116篇
  2001年   75篇
  2000年   75篇
  1999年   74篇
  1998年   82篇
  1997年   71篇
  1996年   46篇
  1995年   45篇
  1994年   32篇
  1993年   23篇
  1992年   77篇
  1991年   54篇
  1990年   72篇
  1989年   59篇
  1988年   64篇
  1987年   75篇
  1986年   52篇
  1985年   63篇
  1984年   50篇
  1983年   57篇
  1982年   29篇
  1981年   21篇
  1980年   37篇
  1979年   33篇
  1978年   29篇
  1977年   36篇
  1976年   24篇
  1975年   30篇
  1974年   25篇
  1972年   25篇
  1971年   28篇
  1970年   22篇
排序方式: 共有3459条查询结果,搜索用时 0 毫秒
71.

Objective

To assess the frequency and clinical features of biopsy‐proven giant cell arteritis (GCA) patients who had fever at the time of diagnosis of the disease, and the relationship between fever, ischemic complications, and the systemic inflammatory response in GCA.

Methods

A retrospective study of biopsy‐proven GCA patients diagnosed between 1981 and 2001 was performed at the single referral hospital for a well‐defined population in the Lugo region of northwest Spain. Patients were considered as having fever if the axillary temperature at the time of admission or during the followup prior to the onset of corticosteroid therapy was ≥38°C.

Results

During the period of study, 21 (10%) of the 210 biopsy‐proven GCA patients had fever. Two of them fulfilled criteria for fever of unknown origin. Patients with fever had a lower frequency of severe ischemic manifestations than the rest of biopsy‐proven GCA patients. They also exhibited a more severe inflammatory disease, with significant abnormality in most laboratory variables, including higher elevation of erythrocyte sedimentation rate, lower values of hemoglobin, and higher proportion of patients with increased alkaline phosphatase. By logistic regression analysis, we observed that patients with fever had an increased risk of developing anemia (odds ratio [OR] 12.24). In contrast, a negative association between severe ischemic manifestations and fever was found (OR 0.41).

Conclusion

Biopsy‐proven GCA patients with fever constitute a subgroup of patients with more severe inflammatory response and less ischemic disease.
  相似文献   
72.
OBJECTIVE: To examine whether promoter polymorphisms associated with variation in interleukin-10 (IL-10) production are relevant to the development of rheumatoid arthritis (RA) or Felty's syndrome (FS). METHODS: DNA was obtained from 44 FS patients, 117 RA patients and 295 controls. The promoter region between -533 and - 1120 was amplified by polymerase chain reaction, and polymorphisms detected by restriction enzyme digest or sequence-specific oligonucleotide probing. RESULTS: We found no significant difference in allele or haplotype frequencies between the groups. CONCLUSION: There is no association between FS or RA and these recently identified IL-10 promoter polymorphisms. Other genetic or environmental factors could explain the alterations in IL-10 levels seen in these conditions.   相似文献   
73.
Quadricuspid aortic valve   总被引:1,自引:0,他引:1  
  相似文献   
74.
Over the course of 17 years, 7 women have had heart disease either during the last three months of pregnancy or during the first three months post-partum, which appear to be associated with their pregnancy. Enquiries made throughout the country and relating to the last decade have yielded 11 additional cases so far unpublished. The clinical features of these cases do not differ from those of other non-obstructive cardiomyopathies occurring other than in pregnancy. The prognosis depends essentially on the factor of cardiac volume during the first few months of the disorder: if significant cardiomegaly persists, death will follow in one case out of two. There exists the problem of the criteria for making a diagnosis of myocardial disease of pregnancy. It should be emphasised that only 4 of the 18 cases were different from the usual cases of myocardial disease, in that they progressed to recovery which is unusual in this condition. One case was particularly illustrative of this, as clinical cure was followed by a relapse at subsequent pregnancy. Because the pregnancy itself seems to be the cause in such a tiny number of cases, a new hypothesis seems right; this is that pregnancy does no more than aggravate an associated or already existent myocardial disorder.  相似文献   
75.
76.
To determine the effect of age on susceptibility to azoxymethane (AOM)-induced colonic aberrant crypt foci (ACF) formation and its underlying mechanism, young and old mice were injected with AOM weekly for 4 or 5 weeks and euthanized 5 or 6 weeks later. Given the same (12 or 15) mg/kg body weight dose of AOM, old mice had significantly more ACF than young mice. However, given the same total dose of AOM (to avoid confounding effect of higher dose to heavier old mice), at a low total dose (1.5 mg) there was no age difference, but at higher total doses (1.8 and 2.2 mg) young mice had significantly more ACF than old mice. These results indicate that the age-related susceptibility to AOM differs depending on whether administration of the carcinogen is based on weight or total dose. These age differences are not due to variations in cyclooxygenase-2 expression, cell proliferation, or AOM hydroxylase activity.  相似文献   
77.

Objective

Cardiovascular disease is the major cause of excessive mortality in rheumatoid arthritis (RA). Atherosclerosis and RA share similar inflammatory mechanisms that include involvement of tumor necrosis factor α (TNFα). Anti‐TNFα antibody improved endothelial function in RA patients after a 12‐week treatment. The aim of the present study was to assess whether improvement of endothelial function is still effective in long‐term infliximab‐treated RA patients.

Methods

Seven RA patients (5 women; age range 25–73 years) were studied. They had been treated with infliximab for at least 1 year and were currently being treated with this drug every 8 weeks. Endothelial‐dependent and independent vasodilatation were measured by brachial ultrasonography.

Results

Following infliximab infusion, a rapid increase in the percentage of endothelial‐dependent vasodilatation was found in all patients (mean ± SD 9.4 ± 5.5% 2 days postinfusion compared with 2.8 ± 2.5% 2 days before infusion). However, values returned to baseline by 4 weeks after infusion. There were no differences in the percentage of endothelial‐independent vasodilatation prior to and after infusion. A decrease in the individual disease activity score for each patient was observed at day 7 postinfusion (P = 0.02).

Conclusion

Our study confirms an active but transient effect of infliximab on endothelial function in RA patients treated periodically with this drug. It may support long‐term use of drugs that block TNFα function to reduce the high incidence of cardiovascular complications in RA.
  相似文献   
78.
79.
OBJECTIVE: The aim of this study was to test the effect of gut manipulation by either novel synbiotics or by metronidazole on either endotoxemia or the severity of liver damage in the course of acute pancreatitis from alcohol ingestion. METHODS: Sprague–Dawley rats were fed for 1 week through an intragastric tube a liquid diet with either: (i) 1 mL t.i.d. of a mixture of synbiotics (Lactobacillus acidophilus, Lactobacillus helveticus and Bifidobacterium in an enriched medium); (ii) 20 mg/kg t.i.d. metronidazole; or (iii) standard diet. Then, acute pancreatitis was induced by caerulein and when the disease was full‐blown, rats were fed an alcohol‐rich diet. Synbiotic and metronidazole treatment was given for a further 2 weeks. Transaminase and endotoxemia levels were measured before treatment, after 6 h, after 24 h and 2 weeks later, at the time the rats were killed. Liver samples were obtained for histological analysis. RESULTS: Synbiotics but not metronidazole improved the acute pancreatitis‐induced increase in endotoxemia and transaminase levels. The addition of alcohol worsened these variables to a limited extent in the synbiotic‐treated group, while metronidazole had a negative effect on liver damage. CONCLUSIONS: Gut flora pretreatment with synbiotics was able to effectively protect against endotoxin/bacterial translocation, as well as liver damage in the course of acute pancreatitis and concomitant heavy alcohol consumption. The beneficial effect of synbiotics on liver histology seems to be correlated with endotoxemia. Metronidazole did not produce such a beneficial effect; in fact, it further worsened liver damage when alcohol was added to the background of ongoing acute pancreatic inflammation.  相似文献   
80.
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