全文获取类型
收费全文 | 33056篇 |
免费 | 1588篇 |
国内免费 | 180篇 |
专业分类
耳鼻咽喉 | 378篇 |
儿科学 | 571篇 |
妇产科学 | 334篇 |
基础医学 | 4205篇 |
口腔科学 | 948篇 |
临床医学 | 2360篇 |
内科学 | 8136篇 |
皮肤病学 | 559篇 |
神经病学 | 2521篇 |
特种医学 | 1289篇 |
外科学 | 5311篇 |
综合类 | 215篇 |
预防医学 | 1187篇 |
眼科学 | 486篇 |
药学 | 2838篇 |
中国医学 | 76篇 |
肿瘤学 | 3410篇 |
出版年
2023年 | 164篇 |
2022年 | 329篇 |
2021年 | 583篇 |
2020年 | 271篇 |
2019年 | 420篇 |
2018年 | 538篇 |
2017年 | 432篇 |
2016年 | 529篇 |
2015年 | 552篇 |
2014年 | 742篇 |
2013年 | 923篇 |
2012年 | 1375篇 |
2011年 | 1499篇 |
2010年 | 867篇 |
2009年 | 729篇 |
2008年 | 1293篇 |
2007年 | 1372篇 |
2006年 | 1393篇 |
2005年 | 1503篇 |
2004年 | 1423篇 |
2003年 | 1377篇 |
2002年 | 1466篇 |
2001年 | 1242篇 |
2000年 | 1378篇 |
1999年 | 1215篇 |
1998年 | 429篇 |
1997年 | 328篇 |
1996年 | 328篇 |
1995年 | 280篇 |
1994年 | 268篇 |
1993年 | 258篇 |
1992年 | 810篇 |
1991年 | 726篇 |
1990年 | 745篇 |
1989年 | 785篇 |
1988年 | 718篇 |
1987年 | 646篇 |
1986年 | 611篇 |
1985年 | 574篇 |
1984年 | 450篇 |
1983年 | 339篇 |
1982年 | 192篇 |
1980年 | 165篇 |
1979年 | 290篇 |
1978年 | 228篇 |
1977年 | 174篇 |
1974年 | 173篇 |
1973年 | 153篇 |
1971年 | 153篇 |
1969年 | 171篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
92.
Tumor autocrine motility factor (AMF) is a cytokine which stimulates both random and directed cell migration by self-producing cells. AMF has been detected in and purified from serum-free conditioned medium of murine B16-F1 melanoma cells. Under nonreducing conditions AMF migrates in sodium dodecyl sulfate-polyacrylamide gel electrophoresis as a single band of Mr 55,000, whereas under reducing conditions it migrates as a single polypeptide of Mr 64,000. Two-dimensional polyacrylamide gel electrophoresis of the purified AMF resolved two polypeptides with isoelectric points of 6.35 (major) and 6.4 (minor). No carbohydrate side chains were detected in the B16-F1 AMF. Purified AMF stimulated B16-F1 cell migration in a dose-dependent fashion and bound directly in a protein-protein-binding assay to the AMF receptor, a cell surface glycoprotein of Mr 78,000 [glycoprotein (gp) 78]. The involvement of gp78 in AMF-stimulated function was demonstrated by motility assays. These results suggest that AMF is the natural ligand for the gp78-AMF receptor. 相似文献
93.
M. Eiro T. Katoh F. Ushikubi S. Narumiya T. Watanabe 《Clinical and experimental nephrology》2002,6(2):85-90
Background. Thromboxane (TX) A2 inhibition or prostaglardin (PGI2) infusion prevents ischemic acute renal failure (ARF) in animal models. However, the pathophysiological roles of the prostanoid
receptors in the development of ischemic ARF are not fully understood, partly because of the limited specificity of their
inhibitors or antagonists.
Methods. We investigated whether targeted disruption of the PGI2 receptor (IP) or TXA2 receptor (TP) genes conferred susceptibility to renal ischemic-reperfusion injury, using IP and TP knockout mice.
Results. Serum creatinine concentration in TP knockout mice was not significantly different from that in wild-type controls. There
were no significant histological differences between TP knockout and wild-type mice. Likewise, IP knockout mice showed no
significant differences from the wild-type controls in regard to creatinine concentration or histological damage.
Conclusions. Lack of TP or IP had no influence on postischemic ARF in mice, indicating that receptors for TXA2 or PGI2 may have minimal roles in the development of this mouse model of ischemic ARF.
Received: July 5, 2001 / Accepted: April 8, 2002 相似文献
94.
The preoperative diagnosis of diffuse heterotopic submucosal cystic malformation of the stomach is very difficult to make with upper gastrointestinal (GI) series or endoscopy. We report a case of submucosal cysts associated with an early gastric carcinoma in which ultrasonography (US) and endoscopic ultrasonography (EUS) were very useful in the preoperative diagnosis. 相似文献
95.
The involvement of protein phosphorylation in cAMP-induced transmembrane current was tested electrophysiologically and pharmacologically in identified neurons of the Japanese land snail, Euhadra peliomphala. Intracellular injection of cAMP elicited a biphasic transmembrane current (cAMP current) which consisted of inward and outward components. The inward component was blocked with Na(+)-free, Ca2(+)-free saline and the outward component abolished by either application of tetraethylammonium or a long-lasting exposure to caffeine in Ca2(+)-free saline. The cAMP current was completely suppressed by the protein kinase inhibitors, protein kinase inhibitor isolated from rabbit muscle or isoquinoline sulfonamide (H-8). The catalytic subunit of cAMP-dependent protein kinase transiently restored the cAMP current suppressed by H-8 nearly to pre-H-8 level. These findings suggest that protein phosphorylation may be an intermediate step in the activation process of the cAMP current. 相似文献
96.
A Okumura M Hayakawa K Watanabe M Kito T Negoro M Kawamura 《No to hattatsu. Brain and development》1992,24(3):278-282
Lesions in the thalamus or basal ganglia have rarely been reported in acute disseminated encephalomyelitis (ADEM). We experienced 2 cases of ADEM, in which MRI showed lesions in the thalamus or basal ganglia. Case 1, a 4-year-old boy, had gait disturbance, hyperesthesia and hyperreflexia. MRI (T2 weighted image) showed multiple high intensity areas in the right frontal lobe, bilateral parietal lobes and bilateral thalami. Case 2, a 4-year-old girl, complained of gait disturbance following a febrile episode, and displayed hyperreflexia. Several days later, she had visual disturbance of the left eye. MRI (T2 weighted image) revealed multiple high intensity areas in the dentate nucleus of left cerebellum, left occipital lobe, bilateral caudate nuclei, and the anterior part of bilateral lenticular nuclei. In both cases, CT could not demonstrate these lesions. Both of them were treated with corticosteroid and recovered rapidly. They had no recurrence. MRI is useful in diagnosis and follow-up of ADEM and may reveal lesions other than cerebral or cerebellar white matters. 相似文献
97.
Makoto Watanabe Takashi Fujimoto Masayuki Iwano Hideo Shiiki Shinobu Nakamura 《Nihon Rinshō Men'eki Gakkai kaishi》2002,25(2):191-198
We describe the case of a 61-year-old woman diagnosed with primary Sj?gren's syndrome (SS) after an 8-year history of IgA nephropathy and a 3-year history of recurrent purpuric rashes. Her two daughters had previously been diagnosed with other autoimmune diseases. One daughter had Graves' disease and the other had Hashimoto's disease and systemic lupus erythematosus. The diagnosis of SS was made based on dryness of mucous membranes, Shirmer test, and parotid sialography. Thrombocytopenia, high platelet-aggregated IgG (PA-IgG) level, and normal megakaryocytes count in bone marrow suggested that her recurrent purpuric rashes were due to idiopathic thrombocytopenic purpura (ITP). Patients with SS may develop other autoimmune diseases. This case aids understanding of the immune pathogenesis and genetic background of SS. 相似文献
98.
99.
Glutathione peroxidase (GSH-Px) is an important selenium-containing enzyme which protects cells from oxidative damage. Two hybridoma clones (GPX-121 and GPX-347), producing mouse IgG1 monoclonal antibodies specific for GSH-Px, were established. Immunoblot analysis revealed that GPX-347 was specific for human GSH-Px, while GPX-121 cross-reacted with human, rat, mouse and rabbit GSH-Px. Correlation between GSH-Px content and its enzymatic activity was investigated in erythrocytes of 76 humans and in human lung adenocarcinoma PC-9 cells by using a sandwich type ELISA. The results indicated that GSH-Px activity was expressed higher than expected from GSH-Px content especially in the range of low GSH-Px concentration. PC-9 cells selenium depleted medium did not stain but the cytoplasm of PC-9 cells grown in medium supplemented with selenium stained strongly. 相似文献
100.