全文获取类型
收费全文 | 23573篇 |
免费 | 1652篇 |
国内免费 | 209篇 |
专业分类
耳鼻咽喉 | 275篇 |
儿科学 | 788篇 |
妇产科学 | 529篇 |
基础医学 | 3258篇 |
口腔科学 | 272篇 |
临床医学 | 1967篇 |
内科学 | 4755篇 |
皮肤病学 | 440篇 |
神经病学 | 1997篇 |
特种医学 | 861篇 |
外国民族医学 | 2篇 |
外科学 | 2960篇 |
综合类 | 550篇 |
一般理论 | 24篇 |
预防医学 | 3258篇 |
眼科学 | 596篇 |
药学 | 1339篇 |
2篇 | |
中国医学 | 137篇 |
肿瘤学 | 1424篇 |
出版年
2023年 | 180篇 |
2022年 | 263篇 |
2021年 | 662篇 |
2020年 | 319篇 |
2019年 | 580篇 |
2018年 | 694篇 |
2017年 | 487篇 |
2016年 | 515篇 |
2015年 | 602篇 |
2014年 | 810篇 |
2013年 | 1140篇 |
2012年 | 1689篇 |
2011年 | 1760篇 |
2010年 | 1044篇 |
2009年 | 817篇 |
2008年 | 1300篇 |
2007年 | 1386篇 |
2006年 | 1294篇 |
2005年 | 1155篇 |
2004年 | 1065篇 |
2003年 | 1001篇 |
2002年 | 881篇 |
2001年 | 533篇 |
2000年 | 491篇 |
1999年 | 410篇 |
1998年 | 161篇 |
1997年 | 153篇 |
1996年 | 119篇 |
1995年 | 107篇 |
1994年 | 108篇 |
1993年 | 78篇 |
1992年 | 295篇 |
1991年 | 265篇 |
1990年 | 308篇 |
1989年 | 289篇 |
1988年 | 240篇 |
1987年 | 240篇 |
1986年 | 216篇 |
1985年 | 192篇 |
1984年 | 153篇 |
1983年 | 115篇 |
1982年 | 73篇 |
1981年 | 75篇 |
1980年 | 61篇 |
1979年 | 122篇 |
1978年 | 75篇 |
1977年 | 61篇 |
1976年 | 58篇 |
1975年 | 66篇 |
1973年 | 75篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
5.
Facial motion is a primary source of social information about other humans. Prior fMRI studies have identified regions of the superior temporal sulcus (STS) that respond specifically to perceived face movements (termed fSTS), but little is known about the nature of motion representations in these regions. Here we use fMRI and multivoxel pattern analysis to characterize the representational content of the fSTS. Participants viewed a set of specific eye and mouth movements, as well as combined eye and mouth movements. Our results demonstrate that fSTS response patterns contain information about face movements, including subtle distinctions between types of eye and mouth movements. These representations generalize across the actor performing the movement, and across small differences in visual position. Critically, patterns of response to combined movements could be well predicted by linear combinations of responses to individual eye and mouth movements, pointing to a parts‐based representation of complex face movements. These results indicate that the fSTS plays an intermediate role in the process of inferring social content from visually perceived face movements, containing a representation that is sufficiently abstract to generalize across low‐level visual details, but still tied to the kinematics of face part movements. 相似文献
6.
7.
Amos Adler Na'ama Sturlesi Noga Fallach Deniz Zilberman-Barzilai Omar Hussein Shlomo E. Blum Eyal Klement Mitchell J. Schwaber Yehuda Carmeli 《Journal of clinical microbiology》2015,53(11):3515-3521
Our objectives were to study the prevalence, risk factors for carriage, and transmission dynamics of extended-spectrum-β-lactamase (ESBL)-producing Enterobacteriaceae (ESBLPE) in a national survey of cattle. This was a point prevalence study conducted from July to October 2013 in Israel. Stool samples were collected from 1,226 cows in 123 sections on 40 farms of all production types. ESBLPE were identified in 291 samples (23.7%): 287 contained Escherichia coli and 4 contained Klebsiella pneumoniae. The number of ESBLPE-positive cows was the highest in quarantine stations and on fattening farms and was the lowest on pasture farms (P = 0.03). The number of ESBLPE-positive cows was the lowest in sections containing adult cows (age, >25 months) and highest in sections containing calves (age, <4 months) (P < 0.001). Infrastructure variables that were significant risk factors for ESBLPE carriage included crowding, a lack of manure cleaning, and a lack of a cooling (P < 0.001 for each), all of which were more common in sections containing calves. Antimicrobial prophylaxis was given almost exclusively to calves and was associated with a high number of ESBLPE carriers (P < 0.001). The 287 E. coli isolates were typed into 106 repetitive extragenic palindromic (REP)-PCR types and mostly harbored blaCTX-M-1 or blaCTX-M-9 group genes. The isolates on the six farms with ≥15 isolates of ESBLPE were of 4 to 7 different REP-PCR types, with one dominant type being harbored by about half of the isolates. Fourteen types were identified on more than one farm, with only six of the farms being adjacent to each other. The prevalence of ESBLPE carriage is high in calves in cowsheds where the use of antimicrobial prophylaxis is common. ESBLPE disseminate within cowsheds mainly by clonal spread, with limited intercowshed transmission occurring. 相似文献
8.
This study deals with a series of operations to isolate the micro-cellulose from the palm tree spathe sheath by using a modified chemical method to take into account the low cost and the completion speed and its characterization using X-ray diffraction technique (XRD), infrared spectroscopy (FTIR) and scanning electron microscope coupled with element analyzer (SEM/EDX). The results showed that the extraction method succeeded in obtaining very pure microscopic fibers with a width of 2–10 μm with a crystallinity index equal to 79.21%, containing the two cellulose features Iβ and II, that, the conversion ratio of the first to the second was estimated at 32, 87%. 相似文献
9.
10.
Joseph M. Northey Kate L. Pumpa Clare Quinlan Ashley Ikin Kellie Toohey Disa J. Smee Ben Rattray 《Journal of Science and Medicine in Sport》2019,22(5):580-585