全文获取类型
收费全文 | 3011667篇 |
免费 | 254545篇 |
国内免费 | 28729篇 |
专业分类
耳鼻咽喉 | 40322篇 |
儿科学 | 86912篇 |
妇产科学 | 74503篇 |
基础医学 | 486518篇 |
口腔科学 | 78597篇 |
临床医学 | 274426篇 |
内科学 | 514919篇 |
皮肤病学 | 81977篇 |
神经病学 | 254300篇 |
特种医学 | 116426篇 |
外国民族医学 | 203篇 |
外科学 | 465221篇 |
综合类 | 122127篇 |
现状与发展 | 70篇 |
一般理论 | 2077篇 |
预防医学 | 241454篇 |
眼科学 | 69913篇 |
药学 | 214408篇 |
186篇 | |
中国医学 | 20149篇 |
肿瘤学 | 150233篇 |
出版年
2022年 | 30740篇 |
2021年 | 64398篇 |
2020年 | 42249篇 |
2019年 | 63903篇 |
2018年 | 75866篇 |
2017年 | 58629篇 |
2016年 | 63656篇 |
2015年 | 81488篇 |
2014年 | 117598篇 |
2013年 | 181418篇 |
2012年 | 89218篇 |
2011年 | 87219篇 |
2010年 | 120830篇 |
2009年 | 124770篇 |
2008年 | 68558篇 |
2007年 | 69072篇 |
2006年 | 80257篇 |
2005年 | 75721篇 |
2004年 | 74050篇 |
2003年 | 64655篇 |
2002年 | 53824篇 |
2001年 | 82494篇 |
2000年 | 74529篇 |
1999年 | 79999篇 |
1998年 | 65054篇 |
1997年 | 63488篇 |
1996年 | 60104篇 |
1995年 | 55441篇 |
1994年 | 49314篇 |
1993年 | 45845篇 |
1992年 | 50868篇 |
1991年 | 47215篇 |
1990年 | 43794篇 |
1989年 | 44092篇 |
1988年 | 40705篇 |
1987年 | 39500篇 |
1986年 | 37157篇 |
1985年 | 37741篇 |
1984年 | 37226篇 |
1983年 | 34915篇 |
1982年 | 37678篇 |
1981年 | 35783篇 |
1980年 | 33775篇 |
1979年 | 28198篇 |
1978年 | 27461篇 |
1977年 | 26209篇 |
1976年 | 23285篇 |
1975年 | 21275篇 |
1974年 | 20228篇 |
1973年 | 19267篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
The distribution in renal tumours of 3-fucosyl-N-acetyl lactosamine has been studied by using the monoclonal antibodies AGF 4.36 and AGF 4.48 and immunoperoxidase methods on tissue sections. Seven of 19 nephroblastomas and 12 of 30 renal cell carcinomas contained the epitope. In nephroblastomas the epitope was found on the terminals of type B tubules in six cases and in one case on the type A or neoplastic tubules. In renal carcinoma the antigen was found on the surface of tumour cells. The results suggest that in kidneys bearing nephroblastomas ureteric bud elements may grow into the tumour from the adjacent kidney. 相似文献
992.
993.
1. Quantitative properties of neuronal activity related to a visual reaction time task were studied in the monkey prefrontal cortex. The task consisted of an initial waiting phase (3.0-s period), a warning phase (green lamp, a variable period of 1.5-3.5 s), a go phase (red lamp), and a reward phase. 2. A total of 189 task-related neurons showed 233 changes in discharge rates during the warning (n = 86), GO (n = 103), and reward (n = 44) phases of the task. Most of the task-related neurons (145/189, 77%) showed changes during only one of the task phases, and were designated W (warning phase)-type (n = 42), GO (go phase)-type (n = 59), and RE (reward phase)-type (n = 44) neurons. The remainder (n = 44, 23%) showed changes during both the warning and the go phases, and were designated WG (warning and go phase)-type neurons. In each phase, onset latencies, peak latencies, and decay times of each change were measured and compared. 3. The changes during the warning phase (n = 86) were separated into three groups based on decay time; that is, phasic changes (n = 31), phasic-tonic changes (n = 23), and tonic changes (n = 32). Onset latencies and peak latencies were homogeneously distributed, and there were no clear groupings, although phasic and phasic-tonic changes tended to show shorter latencies than tonic changes. 4. The changes during the go phase (n = 103) did not show distinct differences, either in terms of decay time or of latency. The changes during the go phase showed various degrees of coupling to both the visual go signal (GS) and lever-release hand movement. To quantitate the coupling, a value to indicate the degrees of coupling (coupling index) was calculated. The changes coupled more strongly to the GS (cue coupled), those coupled more closely to the lever release (movement coupled), and intermediate changes could be distinguished from each other. The cue-coupled changes showed shorter latencies from the time onset of the GS than the movement-coupled changes, and the intermediate changes showed intermediate latencies. The decay time and the duration of the intermediate changes were longer than those of the cue-coupled changes and the movement-coupled changes. 5. The properties of WG-type neurons were compared with those of W-type and GO-type neurons.(ABSTRACT TRUNCATED AT 400 WORDS) 相似文献
994.
995.
996.
997.
998.
Neuropsychiatric disturbances are extremely common in Alzheimer’s disease (AD), and represent integral features of the illness,
as well as appropriate targets for therapy. We are interested in designing trials aimed at preventing or delaying the emergence
of psychopathology in AD. For symptomatic treatment of agitation, mood stabilizers, particularly sodium valproate, have proved
to be beneficial in some patients. Since these effects take several weeks to emerge, we considered that they might be dependent
on potentially neuroprotective actions of valproate, such as inhibition of apoptosis and slowing of neurofibrillary tangle
formation. In this article we present the rationale for testing the neuroprotective potential of valproate experimentally
in mouse models of tauopathy and in a clinical trial of patients with AD who lack psychopathology at baseline. Together, these
studies will provide important tests of the hypothesis that valproate, either through inhibition of tau phosphorylation or
some other mechanism, is a useful therapeutic agent to modify disease progression in AD. 相似文献
999.
With the increased use of indwelling central venous catheters, increasing numbers of cases of Rhodotorula fungemia have been observed in patients with neoplasia and neutropenia. In most patients with catheter-related Rhodotorula fungemia, the condition has been treated with broadspectrum antibiotics. We report two cases of central venous catheter-related
Rhodotorula rubra fungemia that occurred in patients with acute myeloblastic leukemia. Both patients were in a state of neutropenia. One patient
was treated with amphotericin B and his central venous catheter was removed, but he died of Klebsiella pneumoniae bacteremia. The other patient was treated with amphotericin B and discharged, with a central venous catheter, after recovery
from neutropenia. Although the management of catheter-related Rhodotorula fungemia infections remains controversial, resolution of the underlying disease is more important than catheter removal for
recovery from Rhodotorula rubra fungemia.
Received: August 22, 2001 / Accepted: October 8, 2001 相似文献
1000.
David C. Cone MD Susan M. Nedza MD MBA James J. Augustine MD Steven J. Davidson MD MBA 《Academic emergency medicine》2002,9(11):1085-1090
This paper reports the proceedings of the discussion panel assigned to look at clinical aspects of quality in emergency medicine. One of the seven stated objectives of the Academic Emergency Medicine consensus conference on quality in emergency medicine was to educate emergency physicians regarding quality measures and quality improvement as essential aspects of the practice of emergency medicine. Another topic of interest was a discussion of the value of information technology in facilitating quality care in the clinical practice of emergency medicine. It is important to note that this is not intended to be a comprehensive review of this extensive topic, but instead is designed to report the discussion that occurred at this session of the consensus conference. 相似文献