全文获取类型
收费全文 | 9964篇 |
免费 | 918篇 |
国内免费 | 20篇 |
专业分类
耳鼻咽喉 | 94篇 |
儿科学 | 385篇 |
妇产科学 | 242篇 |
基础医学 | 1278篇 |
口腔科学 | 145篇 |
临床医学 | 1309篇 |
内科学 | 2030篇 |
皮肤病学 | 159篇 |
神经病学 | 835篇 |
特种医学 | 389篇 |
外科学 | 1127篇 |
综合类 | 153篇 |
一般理论 | 6篇 |
预防医学 | 1355篇 |
眼科学 | 217篇 |
药学 | 459篇 |
中国医学 | 5篇 |
肿瘤学 | 714篇 |
出版年
2023年 | 104篇 |
2022年 | 166篇 |
2021年 | 441篇 |
2020年 | 240篇 |
2019年 | 381篇 |
2018年 | 377篇 |
2017年 | 276篇 |
2016年 | 299篇 |
2015年 | 303篇 |
2014年 | 412篇 |
2013年 | 545篇 |
2012年 | 782篇 |
2011年 | 743篇 |
2010年 | 387篇 |
2009年 | 372篇 |
2008年 | 541篇 |
2007年 | 529篇 |
2006年 | 464篇 |
2005年 | 480篇 |
2004年 | 430篇 |
2003年 | 380篇 |
2002年 | 282篇 |
2001年 | 126篇 |
2000年 | 100篇 |
1999年 | 118篇 |
1998年 | 104篇 |
1997年 | 88篇 |
1996年 | 96篇 |
1995年 | 62篇 |
1994年 | 67篇 |
1993年 | 79篇 |
1992年 | 60篇 |
1991年 | 61篇 |
1990年 | 82篇 |
1989年 | 80篇 |
1988年 | 61篇 |
1987年 | 70篇 |
1986年 | 69篇 |
1985年 | 51篇 |
1984年 | 33篇 |
1983年 | 39篇 |
1982年 | 34篇 |
1979年 | 25篇 |
1977年 | 39篇 |
1976年 | 32篇 |
1975年 | 23篇 |
1974年 | 35篇 |
1973年 | 38篇 |
1970年 | 23篇 |
1969年 | 23篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
991.
Waters AM Mogg K Bradley BP Pine DS 《Journal of the American Academy of Child and Adolescent Psychiatry》2008,47(4):435-442
ObjectiveTo examine attentional bias for angry and happy faces in 7- to 12-year-old children with generalized anxiety disorder (GAD; n = 23) and nonanxious controls (n = 25).MethodChildren completed a visual probe task in which pairs of face stimuli were displayed for 500 milliseconds and were replaced by a visual probe in the spatial location of one of the faces.ResultsSeverely anxious children with GAD showed an attentional bias toward both angry and happy faces. Children with GAD with a milder level of anxiety and nonanxious controls did not show an attentional bias toward emotional faces. Moreover, within the GAD group, attentional bias for angry faces was associated with increased anxiety severity and the presence of social phobia.ConclusionsBiased attention toward threat as a function of increased severity in pediatric GAD may reflect differing threat appraisal processes or emotion regulation strategies. 相似文献
992.
Some of the most complex auditory neurons known are found in the songbird forebrain, throughout the 'song system', including its basal ganglia nucleus Area X. These cells are selective for the temporal order of the bird's own song (BOS): they typically respond strongly to BOS, but more weakly when the syllable sequence of BOS is played in reverse order (roBOS), indicating that they integrate auditory information over more than single syllables. Here, studying the zebra finch Area X, we found that order selectivity strongly depends on the mean syllable duration of individual songs, decreasing markedly as this duration approaches 150–200 ms. Simply segmenting the same songs differently, creating an increase in average syllable length towards 150 ms, caused a similar decrease in order selectivity. This suggests that song neurons integrate acoustic information over a relatively limited time window, predominantly less than 150 ms. We provided further support for this by showing that a significant fraction of Area X order selectivity was accounted for by the acoustic similarity between each BOS and roBOS, measured using cross-correlation with fixed window sizes, but only when the correlation windows were at least 50 ms and no more than 200 ms long. All the same findings were evident in birds raised without tutor exposure, indicating that tutor learning has little effect on neural mechanisms underlying song temporal selectivity. Our results suggest that song-selective neurons encode much of the temporal context of song using a short, constant time window that is conserved across differences in songs, birds and learning. 相似文献
993.
Choledochojejunostomy is commonly performed for biliary bypass for benign and malignant disease. Anastomotic stricture is a known complication of enteric surgery. We report the use of the laparoscopic linear cutter at laparotomy to revise a choledochojejunostomy created 12 years previously for benign disease. 相似文献
994.
A patient admitted repetitively for vomiting was found to have a radiologic abnormality in the lesser sac, initially interpreted as a pancreatic mass. At exploration, intestinal obstruction due to transmesocolonic herniation of the jejunum explained both the symptoms and the radiologic finding. 相似文献
995.
Baker RA Dickinson TA Shann KG Likosky DS Spiwak AB 《The Annals of thoracic surgery》2008,85(1):359; author reply 359-359; author reply 360
996.
Price CS Williams A Philips G Dayton M Smith W Morgan S 《Clinical orthopaedics and related research》2008,466(11):2842-2847
Nasal colonization with Staphylococcus aureus (SA) increases the risk of surgical site infection (SSI). We first (1) determined the prevalence of asymptomatic nasal colonization
with SA, (2) assessed trends in methicillin resistance with time, (3) ascertained risk factors for nasal colonization; and
(4) correlated SSI to nasal colonization status and procedure. We performed a cross-sectional analysis of SA nasal colonization
among healthy preoperative orthopaedic outpatients between 2003–2005 who were within 2 weeks of surgery. Of 284 patients,
86 (30%) carried SA; of these, 81 (94%) were colonized with methicillin-sensitive and five (6%) with methicillin-resistant
SA (MRSA). Total SA colonization increased from 25/78 (32%) in 2003 to 37/97 (38%) in 2005, and colonization with MRSA increased
from 0/78 (0%) to four of 97 (4%), respectively. We found no associations between nasal carriage and demographics or procedures.
Surgical site infection occurred in nine of 282 (3%), four of which were attributable to SA; these included 0/43 (0%) carriers
who received decolonization with 2% mupirocin, two of 43 (4.7%) who declined decolonization, and two of 196 (1.0%) who were
noncarriers. Nasal colonization with SA, including MRSA, among preoperative orthopaedic outpatients is increasing and their
rates reflect community rates. Knowledge of colonization status may be important in decolonization, choosing perioperative
or any subsequent empiric antibiotics.
One of the authors (CSP) has received funding from GlaxoSmithKline Pharmaceuticals. 相似文献
997.
998.
999.
Fry RB Ray MN Cobaugh DJ Weissman NW Kiefe CI Shewchuk RM Saag KG Curtis JR Allison JJ 《Arthritis and rheumatism》2007,57(8):1539-1545
1000.
Curtis JR Patkar N Xie A Martin C Allison JJ Saag M Shatin D Saag KG 《Arthritis and rheumatism》2007,56(4):1125-1133
OBJECTIVE: To evaluate the risk of serious bacterial infections associated with tumor necrosis factor alpha (TNFalpha) antagonists among rheumatoid arthritis (RA) patients. METHODS: A retrospective cohort study of US RA patients enrolled in a large health care organization identified patients who received either TNFalpha antagonists or methotrexate (MTX). Administrative data were used to identify hospitalizations with possible bacterial infections; corresponding medical records were abstracted and reviewed by infectious disease specialists for evidence of definite infections. Proportional hazards models evaluated time-dependent infection risks associated with TNFalpha antagonists. RESULTS: Hospital medical records with claims-identified suspected bacterial infections were abstracted (n=187) among RA patients who received TNFalpha antagonists (n=2,393; observation time 3,894 person-years) or MTX (n=2,933; 4,846 person-years). Over a median followup time of 17 months, the rate of hospitalization with a confirmed bacterial infection was 2.7% among the patients treated with TNFalpha antagonists compared with 2.0% among the patients treated with MTX only. The multivariable-adjusted hazard ratio (HR) of infection among the patients who received TNFalpha antagonists was 1.9 (95% confidence interval [95% CI] 1.3-2.8) compared with patients who received MTX only. The incidence of infections was highest within 6 months after initiating TNFalpha antagonist therapy (2.9 versus 1.4 infections per 100 person-years; multivariable-adjusted HR 4.2, 95% CI 2.0-8.8). CONCLUSION: The multivariable-adjusted risk of hospitalization with a physician-confirmed definite bacterial infection was approximately 2-fold higher overall and 4-fold higher in the first 6 months among patients receiving TNFalpha antagonists versus those receiving MTX alone. RA patients were at increased risk of serious infections, irrespective of the method used to define an infectious outcome. Patients and physicians should vigilantly monitor for signs of infection when using TNFalpha antagonists, particularly shortly after treatment initiation. 相似文献