全文获取类型
收费全文 | 4137篇 |
免费 | 313篇 |
国内免费 | 126篇 |
专业分类
耳鼻咽喉 | 28篇 |
儿科学 | 123篇 |
妇产科学 | 61篇 |
基础医学 | 517篇 |
口腔科学 | 60篇 |
临床医学 | 531篇 |
内科学 | 863篇 |
皮肤病学 | 70篇 |
神经病学 | 331篇 |
特种医学 | 519篇 |
外国民族医学 | 2篇 |
外科学 | 426篇 |
综合类 | 117篇 |
预防医学 | 336篇 |
眼科学 | 43篇 |
药学 | 319篇 |
中国医学 | 2篇 |
肿瘤学 | 228篇 |
出版年
2022年 | 40篇 |
2021年 | 94篇 |
2020年 | 52篇 |
2019年 | 64篇 |
2018年 | 100篇 |
2017年 | 41篇 |
2016年 | 70篇 |
2015年 | 80篇 |
2014年 | 101篇 |
2013年 | 174篇 |
2012年 | 171篇 |
2011年 | 234篇 |
2010年 | 139篇 |
2009年 | 141篇 |
2008年 | 147篇 |
2007年 | 246篇 |
2006年 | 174篇 |
2005年 | 216篇 |
2004年 | 142篇 |
2003年 | 115篇 |
2002年 | 132篇 |
2001年 | 81篇 |
2000年 | 90篇 |
1999年 | 75篇 |
1998年 | 128篇 |
1997年 | 125篇 |
1996年 | 121篇 |
1995年 | 81篇 |
1994年 | 71篇 |
1993年 | 81篇 |
1992年 | 45篇 |
1991年 | 65篇 |
1990年 | 48篇 |
1989年 | 73篇 |
1988年 | 72篇 |
1987年 | 78篇 |
1986年 | 53篇 |
1985年 | 65篇 |
1984年 | 54篇 |
1983年 | 43篇 |
1982年 | 37篇 |
1981年 | 40篇 |
1980年 | 41篇 |
1979年 | 36篇 |
1978年 | 31篇 |
1977年 | 44篇 |
1976年 | 45篇 |
1975年 | 28篇 |
1973年 | 18篇 |
1970年 | 16篇 |
排序方式: 共有4576条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
5.
6.
7.
Drew T. Marshall John D. Gilbert Roger W. Byard 《Forensic science, medicine, and pathology》2007,3(1):53-55
A 26-year-old man who presented with a 2-year history of intermittent gynecomastia with recent onset of fever, night sweats,
and abdominal distension was found to have a left-sided adrenocortical carcinoma with metastases to the liver and spine. Sudden
death occurred 1 month after his presentation. At autopsy a saddle pulmonary thromboembolus was found occluding the pulmonary
outflow tract, with smaller more peripheral pulmonary thromboemboli. No tumor deposits were identified in the thromboemboli.
The thromboemboli had arisen from a tongue of tumor that had grown through the left adrenal vein into the inferior vena cava.
Despite a high rate of angio-invasion there are very few reports of sudden death resulting from this phenomenon in patients
with adrenocortical carcinoma. 相似文献
8.
Summary— To investigate if the functional alterations observed in resistance arteries of spontaneously hypertensive rats (SHRs) were also present at the coronary level, in vitro experiments were performed in mesenteric resistance arteries (MRA) and in right (RIC) and left interventricular coronary (LIC) arteries taken from 15–25-week-old SHR and age-matched Wistar Kyoto rats WKYs. Using a passive extension protocol, internal diameters corresponding to 100 mmHg intraluminal pressure (D100) were determined and vessels were set up to a normalized internal diameter (0.9 D100). SHR mesenteric resistance arteries had a significantly smaller diameter compared to WKY arteries, whereas both types of SHR coronary arteries had a greater diameter compared to those of WKY rats. In arteries in the absence of contracting agonist, nitro-L-arginine (NOLA, 100 μM) induced a progressive rise in basal tone, which could be reversed by subsequent addition of L-arginine (100 μM) but not D-arginine (100 μM). When expressed as percent of maximal contractions induced by agonists (noradrenaline, NA [10 μM] in MRA; serotonin, 5-HT [10 μM], in RIC and LIC), these contractions were significantly stronger in WKY compared to SHR coronary and mesenteric resistance arteries. In NA-precontracted MRA and 5HT-precontracted coronary arteries in the presence of indomethacin (10 μM), the magnitude of acetylcholine-induced maximal relaxations (expressed as percent of maximal contractions induced by agonists) was greater in WKY compared to SHR arteries. After a 30-min incubation period, NOLA (100 μM) completely inhibited relaxations induced by acetylcholine (0.01–10 μM) in all types of precontracted arteries. Subsequent additions of sodium nitroprusside, (SNP, 10 μM) induced complete relaxations in all preparations. These results show that a basal release of NO or NO-like compound by endothelial cells is present in isolated mesenteric resistance and coronary arteries of WKY rats and SHRs. The contribution of endothelium-derived relaxing factor-nitric oxide (EDRF-NO) to arterial tone was lower in MRA compared to coronary arteries in both strains and in SHR compared to WKY arteries. In the SHR preparations, the impaired relaxation induced by acetylcholine appeared to be due to a functional alteration of the endothelium in the presence of normal reactivity of the smooth muscle cells. 相似文献
9.
10.
Kevin G Becker Insong J Lee James W Nagle Rachel D Canning Ameer M Gado Rosarelis Torres Mihael H Polymeropoulos Paul T Massa WilliamE Biddison Paul D Drew 《International journal of developmental neuroscience》1997,15(7):73
We describe a novel human zinc finger cNDA, C2H2-171. This cDNA represents an mRNA which encodes a protein of 484 amino acids and a calculated molecular weight of 54 kD. Four zinc finger-like domains are found in the C-terminal end of the protein. At the N-terminus, C2H2-171 contains a POZ/tramtrack-like domain similar to that found in the tumor associated zinc finger proteins LAZ-3/BCL-6 and PLZ-F, as well as in non-zinc finger proteins. C2H2-171 RNA is preferentially expressed in the brain, and increases during the course of murine development, with maximal expression in the adult. C2H2-171 RNA is differentially expressed in brain regions, with the highest level of expression in the cerebellum. C2H2-171 RNA was expressed at high levels in primary cerebellar granule cell neurons compared to astrocytes. The gene encoding C2H2-171 is highly conserved in vertebrates, and maps to the terminus of human chromosome 1 (1q44-ter). This chromosomal location is associated with a number of cytogenetic aberrations including those involving brain developmental anomalies and tumorigenesis. These data suggest that C2H2-171 may play an important role in vertebrate brain development and function. 相似文献