全文获取类型
收费全文 | 1810篇 |
免费 | 177篇 |
国内免费 | 50篇 |
专业分类
耳鼻咽喉 | 13篇 |
儿科学 | 132篇 |
妇产科学 | 22篇 |
基础医学 | 170篇 |
口腔科学 | 84篇 |
临床医学 | 143篇 |
内科学 | 391篇 |
皮肤病学 | 39篇 |
神经病学 | 64篇 |
特种医学 | 249篇 |
外科学 | 352篇 |
综合类 | 108篇 |
预防医学 | 90篇 |
眼科学 | 38篇 |
药学 | 81篇 |
中国医学 | 3篇 |
肿瘤学 | 58篇 |
出版年
2023年 | 18篇 |
2022年 | 13篇 |
2021年 | 29篇 |
2020年 | 22篇 |
2019年 | 9篇 |
2018年 | 25篇 |
2017年 | 44篇 |
2016年 | 40篇 |
2015年 | 32篇 |
2014年 | 73篇 |
2013年 | 81篇 |
2012年 | 41篇 |
2011年 | 37篇 |
2010年 | 73篇 |
2009年 | 78篇 |
2008年 | 42篇 |
2007年 | 83篇 |
2006年 | 54篇 |
2005年 | 53篇 |
2004年 | 46篇 |
2003年 | 41篇 |
2002年 | 37篇 |
2001年 | 60篇 |
2000年 | 46篇 |
1999年 | 45篇 |
1998年 | 83篇 |
1997年 | 68篇 |
1996年 | 65篇 |
1995年 | 54篇 |
1994年 | 47篇 |
1993年 | 48篇 |
1992年 | 40篇 |
1991年 | 35篇 |
1990年 | 27篇 |
1989年 | 40篇 |
1988年 | 48篇 |
1987年 | 38篇 |
1986年 | 33篇 |
1985年 | 28篇 |
1984年 | 27篇 |
1983年 | 23篇 |
1982年 | 11篇 |
1981年 | 8篇 |
1980年 | 10篇 |
1979年 | 17篇 |
1978年 | 19篇 |
1977年 | 14篇 |
1976年 | 16篇 |
1975年 | 19篇 |
1922年 | 7篇 |
排序方式: 共有2037条查询结果,搜索用时 31 毫秒
1.
J.L. Bernat A.M. D'Alessandro F.K. Port T.P. Bleck S.O. Heard J. Medina S.H. Rosenbaum M.A. DeVita R.S. Gaston R.M. Merion M.L. Barr W.H. Marks H. Nathan K. O'Connor D.L. Rudow A.B. Leichtman P. Schwab N.L. Ascher R.A. Metzger V. Mc Bride W. Graham D. Wagner J. Warren F.L. Delmonico 《American journal of transplantation》2006,6(2):281-291
A national conference on organ donation after cardiac death (DCD) was convened to expand the practice of DCD in the continuum of quality end-of-life care. This national conference affirmed the ethical propriety of DCD as not violating the dead donor rule. Further, by new developments not previously reported, the conference resolved controversy regarding the period of circulatory cessation that determines death and allows administration of pre-recovery pharmacologic agents, it established conditions of DCD eligibility, it presented current data regarding the successful transplantation of organs from DCD, it proposed a new framework of data reporting regarding ischemic events, it made specific recommendations to agencies and organizations to remove barriers to DCD, it brought guidance regarding organ allocation and the process of informed consent and it set an action plan to address media issues. When a consensual decision is made to withdraw life support by the attending physician and patient or by the attending physician and a family member or surrogate (particularly in an intensive care unit), a routine opportunity for DCD should be available to honor the deceased donor's wishes in every donor service area (DSA) of the United States. 相似文献
2.
By injecting small amounts of CO2 through a needle, one can move bowel or bladder from the intended path of instruments during interventional procedures. The technique worked well in six of seven cases in the pelvis and retroperitoneum; it was not effective in the mediastinum or midabdomen (n = 6). 相似文献
3.
The rejection of sponge matrix allografts across H-2 barriers has generally been found to contain specifically sensitized cytotoxic T cells to donor alloantigen. There is one exception: sponge matrix allografts that differ only with respect to class II alloantigens do not contain specifically sensitized cytotoxic T cells. We therefore investigated the capacity of infiltrating cells removed from sponge matrix allografts to generate delayed hypersensitivity reactions after exposure to fresh alloantigen in a footpad assay. Cells infiltrating class I and II allografts were equally capable of eliciting delayed footpad reactions when injected with specific donor alloantigen into the footpads of naive responder strain mice. Allosensitized T-lymphocyte clones of helper or cytotoxic type were also capable of initiating delayed-type hypersensitivity (DTH) reactions in vivo. We conclude that rejecting allografts across class I or II alloantigenic barriers are infiltrated by cells capable of effecting DTH reactions, in addition to their capacity to exert specific helper or specific cytotoxic reactions. The results also support that both helper and cytotoxic T cells can participate in allospecific DTH reactions. 相似文献
4.
5.
外科医生和手术室人员经常接触手术设备产生的烟气,病人也会暴露于烟气中,特别是腹腔镜手术中产生的烟气滞留于腹腔内这一密闭空间并被吸收.这些烟气是一种与香烟烟气相似的毒性物质,然而对这种毒性物质的影响还未引起足够重视.应该采取必要措施尽可能减少手术中烟气的不良影响. 相似文献
6.
7.
Richard C. Semelka Nikolaos L. Kelekis Gesine John Susan M. Ascher Derek Burdeny Evan S. Siegelman 《Journal of magnetic resonance imaging : JMRI》1997,7(1):153-156
The objective of this study was to demonstrate the appearance of ampullary carcinoma using current MR techniques, including fat suppression, gadolinium enhancement, and MR cholangiography. Nine patients with ampullary carcinoma were examined by MRI at 1.5 T. MR examinations included T1-weighted spoiled gradient echo, T1-weighted fat-suppressed, and immediate postgadolinium spoiled gradient echo images for all patients and MR cholangiography for three patients. The imaging features of ampullary carcinomas, including tumor size and morphology, signal intensity, and enhancement characteristics, were determined. Ampullary carcinomas shown on MR images ranged in size from 1.5 to 5.5 cm. Tumors were low in signal intensity on precontrast T1-weighted spoiled gradient echo and T1-weighted fat-suppressed images relative to normal pancreatic tissue and enhanced less than normal pancreas on immediate postgadolinium spoiled gradient echo images. Tumor conspicuity was greatest on immediate postgadolinium spoiled gradient echo images. MR cholangiography demonstrated high grade obstruction of the common bile duct and mild dilatation of the pancreatic duct at the level of the ampulla with abrupt termination of the ducts in two untreated patients and moderate dilatation of the common bile duct in one patient who had a biliary stent. Ampullary carcinomas can be demonstrated on MR images as small masses arising at the ampulla. Tumors are well defined on immediate postgadolinium spoiled gradient echo images. 相似文献
8.
9.
10.