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   1163篇
  免费   78篇
  国内免费   3篇
耳鼻咽喉   30篇
儿科学   22篇
妇产科学   37篇
基础医学   187篇
口腔科学   3篇
临床医学   83篇
内科学   246篇
皮肤病学   95篇
神经病学   99篇
特种医学   31篇
外科学   170篇
综合类   6篇
预防医学   136篇
眼科学   7篇
药学   45篇
中国医学   3篇
肿瘤学   44篇
  2023年   6篇
  2022年   12篇
  2021年   31篇
  2020年   17篇
  2019年   26篇
  2018年   46篇
  2017年   10篇
  2016年   22篇
  2015年   19篇
  2014年   35篇
  2013年   38篇
  2012年   52篇
  2011年   74篇
  2010年   41篇
  2009年   33篇
  2008年   46篇
  2007年   80篇
  2006年   74篇
  2005年   52篇
  2004年   50篇
  2003年   60篇
  2002年   49篇
  2001年   37篇
  2000年   43篇
  1999年   25篇
  1998年   9篇
  1996年   4篇
  1995年   9篇
  1994年   4篇
  1993年   2篇
  1992年   18篇
  1991年   16篇
  1990年   19篇
  1989年   17篇
  1988年   23篇
  1987年   24篇
  1986年   22篇
  1985年   18篇
  1984年   14篇
  1983年   10篇
  1981年   3篇
  1979年   4篇
  1978年   4篇
  1975年   3篇
  1974年   5篇
  1973年   3篇
  1972年   12篇
  1971年   9篇
  1970年   5篇
  1944年   1篇
排序方式: 共有1244条查询结果,搜索用时 171 毫秒
1.
Lyme arthritis     
Evanescent arthralgias and myalgias are common early symptoms of Lyme disease. Transient, intermittent episodes of monoarticular, oligoarticular, or sometimes migratory polyarticular arthritis, lasting weeks to months, with disease-free intervals, are frequently observed in untreated patients with erythema chronicum migrans. A minority of patients develop chronic joint involvement, most commonly affecting the knee. Antibiotic therapy given during erythema chronicum migrans is often protective with regard to late joint manifestations. In chronic Lyme arthritis, however, the response to antibiotics is variable.  相似文献   
2.
The diagnostic yields of bronchial washings, bronchial brushings and lung biopsy specimens were compared in 50 patients with positive Mycobacterium tuberculosis cultures. The number of positive results obtained with cultures of bronchial brushings was significantly higher than that with bronchial washings (p < 0.001). The histological study of biopsy lung material improved the rate of immediate or rapid diagnosis of tuberculosis (p<0.001).  相似文献   
3.
Primary scleroderma myocardial disease may be due in part to myocardial ischemia caused by a disturbance of the coronary microcirculation. We evaluated the effect of the calcium channel blocker nicardipine on myocardial perfusion assessed by thallium-201 scanning in 16 patients with systemic sclerosis. Thallium-201 single photon emission computerized tomography was performed at baseline and 90 min after 40 mg of oral nicardipine. The mean (+/- SD) number of left ventricular segments with perfusion defects significantly decreased from 6.0 +/- 2.0 at baseline to 4.1 +/- 2.3 after nicardipine (p less than 0.01). The mean global perfusion score significantly increased from 10.2 +/- 1.9 at baseline to 11.9 +/- 2.6 after nicardipine (p less than 0.02). Our study demonstrates short-term improvement in thallium-201 myocardial perfusion with nicardipine in patients with systemic sclerosis.  相似文献   
4.
5.
Ampicillin-resistant strains of Salmonella other than S. typhi constitute a health problem. We tested the antimicrobial susceptibilities to 10 antibiotics of 57 of these strains isolated in a 30-month period. The rates of resistance were as follows: chloramphenicol, 40.3%; tetracycline, 33.3%; gentamicin, 5.3%; co-trimoxazole, 5.3%; nalidixic acid, 1.8%; and amoxicillin-clavulanic acid, cefotaxime, ceftriaxone, aztreonam, and ciprofloxacin, 0%. In our experience, there are alternative antibiotics with excellent in vitro activities.  相似文献   
6.
Summary To characterize the pineal response to pyridoxine, plasma melatonin was measured in one hundred and twenty children 3 hours after vitamin B6 administration. The children, aged between 1.5 and 8 years, were divided in four groups as follows: a) control day group, grouping 27 children sampled at 9:00 and at 12:00; b) control night group, grouping 29 children sampled at 21:00 and at 24:00; c) pyridoxine day group, grouping 30 children sampled at 9:00, then intravenously (i.v.) injected with 3mg/kg of pyridoxine, and sampled at 12:00; and d) pyridoxine night group, grouping 34 children sampled at 21:00, i.v. injected with 3mg/kg of pyridoxine, and sampled at 24:00. Melatonin concentration was measured by radioimmuno assay. The data obtained showed a significant increase in melatonin levels after pyridoxine administration in the pyridoxine night group (39.87 ± 8.02pg/ml basal vs 88.45 ± 9.21 pg/ml after pyridoxine, p < 0.001). The other groups did not showed significant differences in melatonin concentrations. Statistical analysis shows that the administration of pyridoxine during the nocturnal hours represents a stimulating factor to increase the pineal production of melatonin in children.  相似文献   
7.
Mitochondrial DNA Heterogeneity in Tunisian Berbers   总被引:2,自引:0,他引:2  
Berbers live in groups scattered across North Africa whose origins and genetic relationships with their neighbours are not well established. The first hypervariable segment of the mitochondrial DNA (mtDNA) control region was sequenced in a total of 155 individuals from three Tunisian Berber groups and compared to other North Africans. The mtDNA lineages found belong to a common set of mtDNA haplogroups already described in North Africa. Besides the autochthonous North African U6 haplogroup, a group of L3 lineages characterized by the transition at position 16041 seems to be restricted to North Africans, suggesting that an expansion of this group of lineages took place around 10500 years ago in North Africa, and spread to neighbouring populations. Principal components and the coordinate analyses show that some Berber groups (the Tuareg, the Mozabite, and the Chenini‐Douiret) are outliers within the North African genetic landscape. This outlier position is consistent with an isolation process followed by genetic drift in haplotype frequencies, and with the high heterogeneity displayed by Berbers compared to Arab samples as shown in the AMOVA. Despite this Berber heterogeneity, no significant differences were found between Berber and Arab samples, suggesting that the Arabization was mainly a cultural process rather than a demographic replacement.  相似文献   
8.
9.
Approximately 80% of hereditary hearing loss is non-syndromic. Non-syndromic deafness is the most genetically heterogeneous trait. The most common and severe form of hereditary hearing impairment is autosomal recessive non-syndromic hearing loss (ARNSHL), accounting for approximately 80% of cases of genetic deafness. To date, 22 genes implicated in ARNSHL have been identified. Recently a gene, DFNB31/WHRN, which encodes a putative PDZ scaffold protein called whirlin, was found to be responsible for the ARNSHL DFNB31. We found evidence for linkage to the DFNB31locus in a consanguineous Tunisian family segregating congenital profound ARNSHL. Mutation screening of DFNB31/WHRNrevealed four nonpathogenic sequence variants and a novel frameshift mutation [c.2423delG] + [c.2423delG] that changed the reading frame and induced a novel stop codon at amino acid 818 ([p.Gly808AspfsX11] + [p.Gly808AspfsX11]). To determine the contribution of the DFNB31locus in the childhood deafness, we performed linkage analysis in 62 unrelated informative families affected with ARNSHL. No linkage was found to this locus. From this study, we concluded that DFNB31/WHRN is most likely to be a rare cause of ARNSHL in the Tunisian population.  相似文献   
10.
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