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   19839篇
  免费   1560篇
  国内免费   54篇
耳鼻咽喉   152篇
儿科学   573篇
妇产科学   506篇
基础医学   2803篇
口腔科学   494篇
临床医学   2111篇
内科学   4131篇
皮肤病学   333篇
神经病学   1632篇
特种医学   739篇
外国民族医学   17篇
外科学   2425篇
综合类   170篇
一般理论   8篇
预防医学   2036篇
眼科学   276篇
药学   1328篇
中国医学   25篇
肿瘤学   1694篇
  2023年   144篇
  2022年   182篇
  2021年   387篇
  2020年   293篇
  2019年   383篇
  2018年   450篇
  2017年   338篇
  2016年   407篇
  2015年   460篇
  2014年   571篇
  2013年   809篇
  2012年   1084篇
  2011年   1136篇
  2010年   605篇
  2009年   589篇
  2008年   996篇
  2007年   1000篇
  2006年   959篇
  2005年   921篇
  2004年   844篇
  2003年   817篇
  2002年   799篇
  2001年   554篇
  2000年   591篇
  1999年   528篇
  1998年   234篇
  1997年   194篇
  1996年   185篇
  1995年   150篇
  1994年   135篇
  1993年   126篇
  1992年   381篇
  1991年   321篇
  1990年   311篇
  1989年   263篇
  1988年   278篇
  1987年   248篇
  1986年   265篇
  1985年   245篇
  1984年   200篇
  1983年   184篇
  1982年   106篇
  1981年   98篇
  1980年   105篇
  1979年   160篇
  1978年   119篇
  1977年   104篇
  1975年   91篇
  1974年   115篇
  1973年   124篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
91.
92.
93.
94.
95.
This case report describes a 4 year old boy with the unique triad of lipomatous myelomeningocele, congenital hypothyroidism secondary to thyroid agenesis, and sensorineural deafness. While associations between deafness and abnormal thyroid function and deafness and sacral lipoma have previously been described, the constellation of findings in this patient has not been reported.  相似文献   
96.
Since identification of the genes mutated in patients with Autosomal Dominant Polycystic Kidney Disease, PKD1 and PKD2, a large number of different germ line mutations in both genes have been found by conventional PCR-based mutation detection methods. Nevertheless, in approximately 40% of the PKD1 families the disease-causing mutation remains to be elucidated. Complex germ line rearrangements are often not detectable by these standard diagnostic techniques. To detect large deletions in the PKD1 gene we performed Field Inversion Gel Electrophoresis (FIGE) followed by Southern blot analysis with probes selected in the unique and in the reiterated region of this gene. Our analysis revealed 4 deletions in 125 patients, indicating that large deletions in PKD1 are rare. Likely, patients with a deletion that also affects the neighbouring Tuberous Sclerosis Complex 2 (TSC2) gene will be diagnosed as patients with tuberous sclerosis. It was speculated that the exceptional polypyrimidine tract located in intron 21 and the small tract in intron 22, might play a role in the pathogenesis of ADPKD. Since this region is extremely difficult to amplify by PCR, we analysed the 5.8 kb BamHI fragment that contains the polypyrimidine tracts. We did not observe a disease-linked alteration although we detected two different rare variants either in PKD1 or in one of its homologues.  相似文献   
97.
To investigate the distribution of a single base pair mutation within a family with one known case of Fabry disease, DNA from paraffin wax embedded necropsy material was studied using single-strand conformation polymorphism (SSCP) analysis. The proband, who presented with an atypical form of Fabry disease, had a G to A transition in exon 6 of the α-galactosidase A gene. This patient had mainly cardiac symptoms and late onset disease. Further cases of coronary disorders occurred in this family, including the proband's brother who died at 42 years of age of a cardiac disorder. Formalin fixed, paraffin wax embedded material from the brother and two more distant relatives was available for analysis. SSCP analysis showed that the proband's brother also carried the G to A transition. Thus, the atypical form of Fabry disease and unrelated cardiac diseases with similar clinical symptoms occurred within a single family. The variant form is rare but may account for a few of the numerous cases of cardiac disease in men and should be considered when clusters of cases of cardiac disease occur within a single family.  相似文献   
98.
The acid phosphatase (ACP1) locus codes for a low molecular weight protein tyrosine phosphatase (LMPTP) that is found ubiquitously in human tissues. The *A allele of the ACP1 gene is associated with lower total enzymatic activity than the *B and *C alleles. An association between the *A allele and extreme values of body-mass-index (BMI) and dyslipidemia has previously been described in several samples of obese subjects from the Italian population. In the present study, we investigated the relationship between ACP1 *A allele genotypes (*A/*A, *A/*B, and *A/*C) and non-*A allele genotypes (*B/*B, *B/*C, and *C/*C) and metabolic variables in 277 Caucasian post-menopausal subjects consisting of 82 non-obese subjects (BMI/=35) subjects. ACP1 genotypes were found to be significantly associated with total cholesterol (p相似文献   
99.
Ontogeny, differentiation and growth of the endocrine pancreas   总被引:7,自引:0,他引:7  
The pancreas develops from the primitive foregut endoderm, which differentiates into ductal, acinar and endocrine cells. This complex process is probably replicated in the adult pancreas when endocrine cell renewal is required, as may be the case in diabetes mellitus. This review describes what is known about the morphogenesis of the endocrine pancreas during ontogeny and the mechanisms regulating its differentiation and growth. Received: 23 December 1999 / Accepted: 15 February 2000  相似文献   
100.
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