全文获取类型
收费全文 | 24191篇 |
免费 | 1102篇 |
国内免费 | 167篇 |
学科分类
医药卫生 | 25460篇 |
出版年
2023年 | 128篇 |
2022年 | 116篇 |
2021年 | 573篇 |
2020年 | 275篇 |
2019年 | 368篇 |
2018年 | 461篇 |
2017年 | 382篇 |
2016年 | 484篇 |
2015年 | 538篇 |
2014年 | 661篇 |
2013年 | 780篇 |
2012年 | 1395篇 |
2011年 | 1483篇 |
2010年 | 867篇 |
2009年 | 731篇 |
2008年 | 1284篇 |
2007年 | 1471篇 |
2006年 | 1390篇 |
2005年 | 1562篇 |
2004年 | 1505篇 |
2003年 | 1364篇 |
2002年 | 1425篇 |
2001年 | 497篇 |
2000年 | 437篇 |
1999年 | 523篇 |
1998年 | 404篇 |
1997年 | 293篇 |
1996年 | 310篇 |
1995年 | 241篇 |
1994年 | 225篇 |
1993年 | 213篇 |
1992年 | 306篇 |
1991年 | 260篇 |
1990年 | 250篇 |
1989年 | 228篇 |
1988年 | 236篇 |
1987年 | 192篇 |
1986年 | 160篇 |
1985年 | 174篇 |
1984年 | 135篇 |
1983年 | 118篇 |
1982年 | 78篇 |
1981年 | 65篇 |
1979年 | 101篇 |
1978年 | 91篇 |
1977年 | 68篇 |
1976年 | 52篇 |
1974年 | 52篇 |
1973年 | 52篇 |
1972年 | 57篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
31.
32.
33.
Staging of esophageal carcinoma in vitro with 4.7-T MR imaging 总被引:4,自引:0,他引:4
34.
35.
Shoji Sunada Masahiko Miyata Yasuhiro Tanaka Kenzo Okumura Makoto Nakamuro Toru Kitagawa Ryota Shirakura Yasunaru Kawashima 《Surgery today》1992,22(1):74-77
An aggressive pancreatectomy was performed on a 53 year old Japanese man with advanced cancer of the pancreas. The tumor originated from the body of the pancreas and invaded the stomach, duodenum, left kidney, transverse colon and common hepatic artery. An unexpected cancer was also found in the head of the pancreas during the operation. Therefore, total pancreatectomy, total gastrectomy, left adrenonephrectomy, resection of the left transverse colon and dissection of the regional lymph nodes were performed. Resection of the common hepatic artery was also performed, followed by an end-to-end anastomosis between the common hepatic artery and celiac trunk. The postoperative course was uneventful and the patient was doing well until nine months after the operation when multiple metastatic lesions were noted in the liver. He died 391 days after the operation from hepatic failure. 相似文献
36.
Yoshihiro Wakayama Masahiko Inoue Makoto Murahashi Seiji Shibuya Takahiro Jimi Hiroko Kojima Hiroaki Oniki 《Annals of neurology》1996,39(2):217-223
The ultrastructural localization of adhalin and its relations to dystrophin, β-dystroglycan, and β-spectrin were studied in normal murine skeletal myofibers. The C-terminal peptides of adhalin and β-dystroglycan were synthesized based on their cDNAs, and the affinity-purified antibodies against these peptides were produced. Single-immunolabeling electron microscopy showed that the adhalin was located just inside the muscle plasma membrane or inside the myofiber a short distance from the plasma membrane. The adhalin signal was also noted at the sarcoplasmic side of plasmalemmd invaginations or at vesicular structures in subsarcolemmal areas. Double-immunogold-labeling electron microscopy disclosed a similar localization of dystrophin, β-dystroglycan, and β-spectrin. The close association of adhalin with dystrophin or β-dystroglycan was demonstrated by formation of doublets by signals of antibodies of adhalin with those of dystrophin or β-dystroglycan and was confirmed by statistical analyses. This study demonstrated that the location of adhalin is close to that of dystrophin and β-dystroglycan at the muscle plasma membrane. 相似文献
37.
38.
39.
Non-viral in vivo thrombomodulin gene transfer prevents early loss of thromboresistance of grafted veins. 总被引:1,自引:0,他引:1
Noriyuki Tabuchi Masayoshi Shichiri Aya Shibamiya Takatoshi Koyama Fumie Nakazawa Jihwa Chung Shinsaku Hirosawa Makoto Sunamori 《European journal of cardio-thoracic surgery》2004,26(5):995-1001
OBJECTIVE: Immediate loss of thrombomodulin activity in the endothelium of vein grafts has been demonstrated during 90 min exposure to arterial circulation; this loss of activity is ascribed as an important cause of early thrombosis. Conventional ex vivo gene transfection after vein harvest cannot cover this acute period immediately after implantation. We have established a highly efficient non-viral gene therapy protocol utilizing modified transferrin receptor-facilitated gene transfer. Using this technique, we examined whether in vivo thrombomodulin gene therapy, directed to the endothelium of rat veins 2 days prior to grafting, may prevent thromboresistance impairment of vein grafts under simulated arterial circulation. METHODS: Abdomen of SD rat was opened and cationic liposome:transferrin:thrombomodulin gene complexes or the vector without DNAs were applied to the inferior vena cava of rats while blood flow was reduced by proximal and distal clamping. After 2 days, the transfected veins were harvested and thrombomodulin expression and thromboresistance properties determined before and after exposure to an artificial circuit. RESULTS: The trial of gene transfection using variable doses of DNAs confirmed that 7.5 microg of total DNAs was the most efficient quantity for thrombomodulin gene transfection to IVCs, although accompanying an increase of gene expression in other downstream organs. By transfection of the thrombomodulin gene in IVCs, the generation capacity of activated protein C in venous endothelium increased three-fold compared with veins treated with vector alone (P<0.01). Under simulated arterial circulation, perfusion of veins treated with vector alone decreased thrombomodulin activity to 36% of preperfused levels (P<0.01), whereas transfected grafts preserved the activity at normal vein endothelium levels even after perfusion. Consequently, the increase in endothelial thrombin activity induced by simulated arterial circulation was markedly attenuated in transfected veins (P<0.01), while immunohistochemistry confirmed the preservation of endothelial lining. CONCLUSIONS: Transferrin receptor-facilitated in vivo gene transfer to the inferior vena cava resulted in sufficient thrombomodulin gene expression immediately after graft implantation and subsequent maintenance of thromboresistance even after exposure to arterial pressure. Although further studies are needed, the present results suggest the possibility of gene therapy targeting acute phases of vein graft disease. 相似文献