全文获取类型
收费全文 | 4183篇 |
免费 | 334篇 |
国内免费 | 43篇 |
专业分类
耳鼻咽喉 | 48篇 |
儿科学 | 168篇 |
妇产科学 | 62篇 |
基础医学 | 617篇 |
口腔科学 | 57篇 |
临床医学 | 527篇 |
内科学 | 825篇 |
皮肤病学 | 71篇 |
神经病学 | 322篇 |
特种医学 | 236篇 |
外科学 | 518篇 |
综合类 | 38篇 |
一般理论 | 2篇 |
预防医学 | 452篇 |
眼科学 | 111篇 |
药学 | 250篇 |
中国医学 | 7篇 |
肿瘤学 | 249篇 |
出版年
2023年 | 42篇 |
2022年 | 58篇 |
2021年 | 158篇 |
2020年 | 103篇 |
2019年 | 155篇 |
2018年 | 157篇 |
2017年 | 113篇 |
2016年 | 105篇 |
2015年 | 122篇 |
2014年 | 189篇 |
2013年 | 238篇 |
2012年 | 328篇 |
2011年 | 312篇 |
2010年 | 185篇 |
2009年 | 155篇 |
2008年 | 194篇 |
2007年 | 222篇 |
2006年 | 174篇 |
2005年 | 156篇 |
2004年 | 133篇 |
2003年 | 119篇 |
2002年 | 123篇 |
2001年 | 62篇 |
2000年 | 68篇 |
1999年 | 43篇 |
1998年 | 76篇 |
1997年 | 69篇 |
1996年 | 59篇 |
1995年 | 57篇 |
1994年 | 53篇 |
1993年 | 36篇 |
1992年 | 35篇 |
1991年 | 28篇 |
1990年 | 22篇 |
1989年 | 46篇 |
1988年 | 49篇 |
1987年 | 30篇 |
1986年 | 29篇 |
1985年 | 35篇 |
1984年 | 20篇 |
1983年 | 20篇 |
1982年 | 20篇 |
1981年 | 19篇 |
1980年 | 12篇 |
1979年 | 20篇 |
1978年 | 11篇 |
1977年 | 16篇 |
1976年 | 14篇 |
1975年 | 8篇 |
1974年 | 11篇 |
排序方式: 共有4560条查询结果,搜索用时 31 毫秒
1.
Eloise R. Galligan Lindsey Fix Sameera Husain Philip Zachariah Darrell J. Yamashiro Christine T. Lauren 《Journal of cutaneous pathology》2019,46(2):159-161
We report a case of disseminated Trichosporon asahii in a patient on systemic antifungal therapy who presented with multiple cutaneous nodules suggestive of fungal infection. Histologic features resembled neutrophilic eccrine hidradenitis but staining with periodic acid‐Schiff and Gomori methenamine silver confirmed the clinical diagnosis. This case highlights the importance of maintaining suspicion for trichosporonosis and contextualizing histologic findings within the underlying clinical picture. 相似文献
2.
3.
Rebecca P. Ang Robert M. Klassen Wan Har Chong Vivien S. Huan Isabella Y.F. Wong Lay See Yeo Lindsey L. Krawchuk 《Journal of adolescence》2009,32(5):1225-1237
We provide further evidence for the two-factor structure of the 9-item Academic Expectations Stress Inventory (AESI) using confirmatory factor analysis on a sample of 289 Canadian adolescents and 310 Singaporean adolescents. Examination of measurement invariance tests the assumption that the model underlying a set of scores is directly comparable across groups. This study also examined the cross-cultural validity of the AESI using multigroup confirmatory factor analysis across both the Canadian and Singaporean adolescent samples. The results suggested cross-cultural invariance of form, factor loadings, and factor variances and covariances of the AESI across both samples. Evidence of AESI's convergent and discriminant validity was also reported. Findings from t-tests revealed that Singaporean adolescents reported a significantly higher level of academic stress arising from self expectations, other expectations, and overall academic stress, compared to Canadian adolescents. Also, a larger cross-cultural effect was associated with academic stress arising from other expectations compared with academic stress arising from self expectations. 相似文献
4.
Mark A. Trimble Salvador Borges-Neto Stuart Smallhelser Ji Chen Emily F. Honeycutt Linda K. Shaw Jaekyeong Heo Robert A. Pagnanelli E. Lindsey Tauxe Ernest V. Garcia Fabio Esteves Frank Seghatol-Eslami G. Neal Kay Ami E. Iskandrian 《Journal of nuclear cardiology》2007,14(3):298-307
Background Cardiac resynchronization therapy (CRT) is approved for the treatment of patients with advanced systolic heart failure and
evidence of dyssynchrony on electrocardiograms. However, a significant percentage of patients do not demonstrate improvement
with CRT. Echocardiographic techniques have been used for more accurate determination of dyssynchrony. Single photon emission
computed tomography (SPECT) myocardial perfusion imaging has not previously been used to evaluate cardiac dyssynchrony. The
objective of this study is to evaluate mechanical dyssynchrony as described by phase analysis of gated SPECT images in patients
with left ventricular dysfunction, conduction delays, and ventricular paced rhythms.
Methods and Results A novel count-based method is used to extract regional systolic wall thickening amplitude and phase from gated SPECT images.
Five indices describing the phase dispersion of the onset of mechanical contraction are determined: peak phase, phase SD,
bandwidth, skewness, and kurtosis. These indices were determined in consecutive patients with left ventricular dysfunction
(n=120), left bundle branch block (n=33), right bundle branch block (n=19), and ventricular paced rhythms (n=23) and were
compared with normal control subjects (n=157). Phase SD, bandwidth, skewness, and kurtosis were significantly different between
patients with left ventricular dysfunction, left bundle branch block, right bundle branch block, and ventricular paced rhythms
and normal control subjects (all P<.001) Peak phase was significantly different between patients with right ventricular paced rhythms and normal control subjects
(P=.001).
Conclusions A novel SPECT technique for describing left ventricular mechanical dyssyn-chrony has been developed and may prove useful in
the evaluation of patients for CRT.
This study was funded in part by a research grant from the Medtronic-Duke Strategic Alliance, of which Dr Borges-Neto is the
primary investigator. 相似文献
5.
6.
7.
8.
INVOLVEMENT OF NON-NMDA AND NMDA RECEPTORS IN GLUTAMATE-INDUCED PRESSOR OR DEPRESSOR RESPONSES OF THE PONS AND MEDULLA 总被引:1,自引:0,他引:1
SY Chen WC Wu CJ Tseng JS Kuo CY Chai 《Clinical and experimental pharmacology & physiology》1997,24(1):46-56
1. Fifty-five intact and six baroreceptor denervated and vagotomized cats of either sex were anaesthetized intraperito-neally with urethane (400 mg/kg) and a-chloralose (40 mg/kg). Responses of the systemic arterial pressure (SAP), mean SAP (MSAP) and sympathetic vertebral nerve (VNA) and renal nerve activities (RNA) were recorded. 2. In intact animals, monosodium L-glutamate (Glu, 0.1 mol/L, 50 nL) was microinjected into pressor areas of the locus coeruleus (LC), gigantocellular tegmental field (GTF), rostral ventrolateral medulla (RVLM) and dorsomedial medulla (DM), and the depressor areas of caudal ventrolateral medulla (CVLM). The induced actions were compared before and after microinjection of either glutamate antagonists, glutamate diethylester (GDEE, 0.5 mol/L, 50–100nL), a competitive AMPA receptor blocker, or 2-amino-5-phosphonovaleric acid (D-AP5, 0.025 mol/L, 50–100 nL), a competitive N-methyl-D-aspartate (NMDA) receptor blocker. GDEE completely blocked the increases of SAP and VNA elicited from all pressor areas. D-AP5 only partially blocked the pressor but slightly blocked VNA and RNA responses from LC, GTF and DM, particularly those from RVLM. Neither GDEE nor D-AP5 blocked the depressor responses of SAP and two nerve activities elicited from CVLM. 3. In baroreceptor denervated animals, NMDA (2 mmol/L, 50–100 nL) and AMPA (0.2 mmol/L, 50–100 nL) were micro-injected into the same pressor areas of GTF, RVLM and DM and the depressor area of CVLM responsive to Glu activation (0.1 mol/L, 30 nL). In RVLM, DM and CVLM, the results of either NMDA or AMPA were similar to those induced by Glu. However, in GTF, microinjection of either NMDA or AMPA did not induce similar responses to Glu. This suggests that the nature of GTF may differ from RVLM and DM. 4. The above results suggest that the Glu-induced pressor responses from LC, GTF, DM and especially RVLM, are primarily mediated through AMPA receptors. The Glu-induced depressor responses from CVLM may not be predominantly mediated by either AMPA or NMDA receptors. 5. In both baroreceptor-intact and -denervated cats stimulation of the pressor areas often produced an increase of VNA and a decrease of RNA, while in the depressor CVLM decreased both VNA and RNA. The VNA, but not RNA were positively correlated with the pressor responses, while both VNA and RNA were positively correlated with the depressor responses. This may suggest that neurons of the sympathetic vertebral and renal nerves are topographically organized in the brain. 相似文献
9.
10.