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   49448篇
  免费   3711篇
  国内免费   203篇
耳鼻咽喉   592篇
儿科学   1044篇
妇产科学   985篇
基础医学   6828篇
口腔科学   1158篇
临床医学   4895篇
内科学   10305篇
皮肤病学   1121篇
神经病学   4747篇
特种医学   2088篇
外国民族医学   2篇
外科学   8933篇
综合类   502篇
一般理论   78篇
预防医学   2762篇
眼科学   980篇
药学   2927篇
中国医学   88篇
肿瘤学   3327篇
  2023年   425篇
  2022年   877篇
  2021年   1737篇
  2020年   1025篇
  2019年   1354篇
  2018年   1561篇
  2017年   1052篇
  2016年   1235篇
  2015年   1419篇
  2014年   1906篇
  2013年   2253篇
  2012年   3648篇
  2011年   3622篇
  2010年   1999篇
  2009年   1796篇
  2008年   2852篇
  2007年   2880篇
  2006年   2684篇
  2005年   2509篇
  2004年   2322篇
  2003年   2115篇
  2002年   1945篇
  2001年   626篇
  2000年   590篇
  1999年   608篇
  1998年   447篇
  1997年   358篇
  1996年   266篇
  1995年   260篇
  1994年   218篇
  1993年   221篇
  1992年   395篇
  1991年   373篇
  1990年   338篇
  1989年   308篇
  1988年   285篇
  1987年   278篇
  1986年   264篇
  1985年   295篇
  1984年   232篇
  1983年   227篇
  1982年   186篇
  1981年   167篇
  1980年   175篇
  1979年   199篇
  1978年   164篇
  1977年   150篇
  1976年   145篇
  1974年   148篇
  1973年   131篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
81.
Familial Sneddon's syndrome   总被引:4,自引:0,他引:4  
We report the familial occurrence and apparent autosomal dominant inheritance of Sneddon's syndrome with variable clinical expression. The proband, a 40-year-old woman, presented with livedo reticularis and progressive neurological deterioration following a stroke. The diagnosis was confirmed by cerebral angiogram and skin biopsy, both showing the characteristic findings. Two of the patient's sisters were reported to have been similarly affected in the past. Her mother, two additional siblings and five of her seven children exhibited various vasospastic skin phenomena. Familial aggregation of this disorder may be common and a genetic basis may be involved in its pathogenesis.  相似文献   
82.
In his autobiography, Dr. Wilder Penfield relates the medical history of his sister, Mrs. Ruth Inglis, who developed a right frontal oligodendroglioma. Penfield performed the initial craniotomy on her, and after her death, reported the case in a paper on frontal lobe function in humans. Although Penfield has provided more than adequate information on certain aspects of his sister's illness, little has been published concerning her subsequent operation performed by Dr. Harvey Cushing at the Peter Bent Brigham Hospital. We feel this case is significant for several reasons. First, it sheds some light on Penfield's personal relationship with Cushing and his sister; it also shows the deep interest that Dr. Cushing took in his patients. Second, this case nicely illustrates how Cushing used his postoperative drawings to make his operative notes more precise. Finally, we see a sample of the work done by Dr. Louise Eisenhardt as pathologist at the Peter Bent Brigham Hospital.  相似文献   
83.
84.
Forty-four isolates of Acinetobacter calcoaceticus var anitratus collected during hospital outbreaks were studied using polyacrylamide gel electrophoresis (PAGE), plasmid analysis, antibiograms and biochemical tests to determine their degree of similarity. Reproducibility tests were also carried out on the PAGE and biochemical techniques to determine their validity when used to compare bacteria of the same type isolated intermittently. PAGE data was analysed densitometrically and isolates compared using a similarity matrix. All methods were able to subdivide the isolates, but results did not always correlate well between methods. Reproducibility data indicated that careful attention to technique is required when organisms are examined by PAGE sequentially. Results suggest that no single biotyping technique is likely to be adequate and that electrophoretic, biochemical and antibiogram data may complement one another and other epidemiological data in the typing of these organisms.  相似文献   
85.
1. Second messenger responses to natriuretic peptides were studied in guinea-pig cerebellar slices by use of radioactive precursors. 2. The rank order of potency of the different natriuretic peptides in generating [3H]-guanosine 3':5'-cyclic monophosphate (cyclic GMP) was atrial natriuretic peptide (ANP) > brain natriuretic peptide (BNP) >> C-type natriuretic peptide (CNP) with EC50 values of 19.5 +/- 8.8 nM for ANP and 169 +/- 41 nM for BNP. CNP induced [3H]-cyclic GMP accumulation only at concentrations greater than 1 microM. 3. An additive response to ANP (1 microM) was observed in the presence of the adenosine receptor agonist, 5'-N-ethylcarboxamidoadenosine (NECA, 10 microM) or the soluble guanylyl cyclase activator, sodium nitroprusside (SNP, 100 microM) for [3H]-cyclic GMP accumulation. 4. ANP, BNP and CNP (all at 1 microM) failed to alter significantly either basal-, forskolin- (10 microM), isoprenaline- (100 microM), or NECA- (10 microM) induced [3H]-cyclic AMP generation. Natriuretic peptides also did not change the [3H]-cyclic AMP steady-state reached after 10 min of treatment with 10 microM forskolin. 5. Natriuretic peptides failed to elicit significant accumulation of [3H]-inositol phosphates at concentrations up to 10 microM. 6. These data are consistent with the presence of ANPA, rather than ANPB or clearance receptors (C-receptors), linked to second messenger cascades in guinea-pig cerebellar slices.  相似文献   
86.
The stability of phenytoin in blood collected in plain and serum separator tubes (SSTs) was investigated under simulated storage and transport conditions. The drug was generally more stable in plain collection tubes than in SSTs. No degradation occurred in plain red-top tubes or in refrigerated SSTs, but clinically significant degradation was present in SSTs stored at room temperature (25 degrees C) and at elevated temperature (32 degrees C) 24 h after collection. The mean loss was 17.9% at 25 degrees C and 25.9% at 32 degrees C. It is recommended that if blood is to be transported or stored in SSTs, the samples be refrigerated unless assay can be performed within 8 h.  相似文献   
87.
88.
89.
90.
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