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   2092篇
  免费   112篇
  国内免费   5篇
耳鼻咽喉   6篇
儿科学   92篇
妇产科学   70篇
基础医学   167篇
口腔科学   192篇
临床医学   124篇
内科学   686篇
皮肤病学   113篇
神经病学   146篇
特种医学   49篇
外科学   237篇
综合类   44篇
一般理论   2篇
预防医学   68篇
眼科学   27篇
药学   93篇
中国医学   7篇
肿瘤学   86篇
  2023年   10篇
  2022年   30篇
  2021年   41篇
  2020年   26篇
  2019年   33篇
  2018年   34篇
  2017年   36篇
  2016年   41篇
  2015年   63篇
  2014年   75篇
  2013年   98篇
  2012年   130篇
  2011年   140篇
  2010年   97篇
  2009年   72篇
  2008年   90篇
  2007年   93篇
  2006年   96篇
  2005年   100篇
  2004年   115篇
  2003年   85篇
  2002年   62篇
  2001年   49篇
  2000年   67篇
  1999年   46篇
  1998年   20篇
  1997年   13篇
  1996年   13篇
  1995年   8篇
  1994年   14篇
  1993年   6篇
  1992年   32篇
  1991年   32篇
  1990年   47篇
  1989年   28篇
  1988年   24篇
  1987年   29篇
  1986年   21篇
  1985年   19篇
  1984年   18篇
  1983年   11篇
  1982年   19篇
  1981年   7篇
  1979年   15篇
  1978年   12篇
  1977年   13篇
  1975年   11篇
  1973年   9篇
  1972年   8篇
  1969年   18篇
排序方式: 共有2209条查询结果,搜索用时 15 毫秒
61.
We describe two adult patients with left ventricular noncompaction in whom live/real time three-dimensional transthoracic echocardiography (3DTTE) supplemented two-dimensional transthoracic echocardiography in making a definitive diagnosis of clots coexisting with trabeculations in the left ventricle. Mobility of clots and the presence of central echolucencies consistent with clot lysis were best demonstrated by 3DTTE and served to confidently differentiate clots from adjacent trabeculations.  相似文献   
62.
Phenotypic evaluation of the basal-like subtype of invasive breast carcinoma.   总被引:26,自引:0,他引:26  
Microarray profiling of invasive breast carcinomas has identified five distinct subtypes of tumors (luminal A, luminal B, normal breast-like, HER2 overexpressing, and basal-like) that are associated with different clinical outcomes. The basal-like subtype is associated with poor clinical outcomes and is the subtype observed in BRCA1-related breast cancers. The aim of this study was to characterize the histologic and immunophenotypic properties of breast basal-like carcinomas that were first positively identified using DNA microarray analysis. Detailed histologic review was performed on 56 tumors with known microarray profiles (23 basal-like, 23 luminal, and 12 HER2+). Immunohistochemistry for estrogen receptor (ER), HER2, EGFR, smooth muscle actin (SMA), p63, CD10, cytokeratin 5/6, cytokeratin 8/18, and vimentin was performed on 18 basal-like, 16 luminal, and 12 HER2+ tumors. The basal-like tumors were grade 3 ductal/NOS (21/23) or metaplastic (2/23) carcinomas that frequently showed geographic necrosis (17/23), a pushing border of invasion (14/23), and a stromal lymphocytic response (13/23). Most basal-like tumors showed immunoreactivity for vimentin (17/18), luminal cytokeratin 8/18 (15/18), EGFR (13/18), and cytokeratin 5/6 (11/18), while positivity for the myoepithelial markers SMA (4/18), p63 (4/18) and CD10 (2/18) was infrequent. All basal-like tumors tested were ER- and HER2-. Morphologic features significantly associated with the basal-like subtype included markedly elevated mitotic count (P<0.0001), geographic tumor necrosis (P=0.0003), pushing margin of invasion (P=0.0001), and stromal lymphocytic response (P=0.01). The most consistent immunophenotype seen in the basal-like tumors was negativity for ER and HER2, and positivity for vimentin, EGFR, cytokeratin 8/18, and cytokeratin 5/6. The infrequent expression of myoepithelial markers in basal-like carcinomas does not support a direct myoepithelial cell derivation of these tumors. These findings should further assist in the identification of basal-like carcinomas in clinical specimens, facilitating treatment and epidemiologic studies of this tumor subtype.  相似文献   
63.
64.

Background  

Uterine rupture during pregnancy is a rare occurrence that frequently results in high incidence of maternal and fetal morbidity and mortality.  相似文献   
65.
Ambient temperature related sleep changes in rats neonatally treated with capsaicin. PHYSIOL BEHAV 00(0) 000-000, 2004. The study was conducted on adult male Wistar rats, neonatally treated with capsaicin to destroy the peripheral warm receptors. The sleep-wakefulness was recorded for 5 h at an ambient temperature (T(amb)) of 18, 24, 30 and 33 degrees C on different days. The rectal temperatures (T(r)) of the rats were studied on exposure to 6 and 37 degrees C for 2 h to assess their thermoregulatory ability. The changes in the behavioral thermoregulation were assessed by noting the thermal preference of rats when they were placed in an environmental chamber with 3 interconnected compartments maintained at 24, 27 and 30 degrees C. Slow wave (SWS) and rapid eye movement (REM) sleep were decreased at 18 degrees C and increased at 30 degrees C, in control rats. There was a decrease in REM sleep and no change in SWS when T(amb) was raised from 30 to 33 degrees C. However, in neonatally capsaicin treated rats, sleep was increased even at 33 degrees C, though there was no significant change in sleep when T(amb) was increased from 18 to 24 degrees C. Capsaicin treated rats showed thermoregulatory deficiency at 37 degrees C but the thermal preference was unaltered in these rats. The results suggest that the central warm receptors can produce alteration in sleep at different T(amb), even in absence of peripheral warm receptors. The behavioral thermoregulation was unaffected in these rats, though their ability to defend the body temperature in warm environment was affected.  相似文献   
66.
Peroxisomal disorders include a complex spectrum of diseases, characterized by a high heterogeneity from both the clinical and the biochemical points of view. Specific assays are required for the study of peroxisome metabolism. Among these, pipecolic acid evaluation is considered as a supplementary test. We have established the diagnostic role of pipecolic acid in 30 patients affected by a peroxisomal defect (5 Zellweger syndromes, 10 Infantile Refsum diseases, 1 neonatal adrenoleukodystrophy, 6 patients affected by a peroxisomal biogenesis disorder with unclassified phenotype, 1 case of rhizomelic chondrodysplasia punctata (RCDP), 2 acyl-CoA oxidase deficiencies, 2 bifunctional enzyme deficiencies, 2 Refsum diseases, and 1 beta-oxidation deficiency). Pipecolic acid was increased in all generalized peroxisomal disorders, while normal pipecolic acid with abnormal very long chain fatty acid concentrations was strong evidence for a single peroxisomal enzyme deficiency. Unexpectedly, hyperpipecolic acidaemia was found also in a child affected by RCDP and in two patients with Refsum disease. In six patients the suggestion of a peroxisomal disorder was raised by the fortuitous finding of a pipecolic acid peak in amino acid chromatography, routinely performed as a general metabolic screening. For all patients, pipecolic acid proved to be a useful parameter in the biochemical classification of peroxisomal disorders.  相似文献   
67.
Diffuse lipomatosis is a rare disorder of adipose tissue occurring in young people . It has a predilection for trunk and proximal extremities where it presents as poorly circumscribed overgrowth of fatty tissue. Definite diagnosis is established by histological examination of tumor. Though it attains extensive size and has a high tendency to recur, the clinical course is benign.  相似文献   
68.
69.
A case of fibromuscular dysplasia involving both carotid, one vertebral and both renal arteries is described. The important and frequent association between fibromuscular dysplasia involving both cephalic and renal arteries is emphasised. The clinical presentation of cephalic fibromuscular dysplasia is discussed.  相似文献   
70.
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