全文获取类型
收费全文 | 131420篇 |
免费 | 31089篇 |
国内免费 | 1139篇 |
专业分类
耳鼻咽喉 | 2866篇 |
儿科学 | 3870篇 |
妇产科学 | 3128篇 |
基础医学 | 6610篇 |
口腔科学 | 5418篇 |
临床医学 | 31553篇 |
内科学 | 30199篇 |
皮肤病学 | 3595篇 |
神经病学 | 15544篇 |
特种医学 | 4285篇 |
外国民族医学 | 1篇 |
外科学 | 20688篇 |
综合类 | 465篇 |
现状与发展 | 40篇 |
一般理论 | 49篇 |
预防医学 | 18288篇 |
眼科学 | 2461篇 |
药学 | 3177篇 |
1篇 | |
中国医学 | 49篇 |
肿瘤学 | 11361篇 |
出版年
2024年 | 841篇 |
2023年 | 5461篇 |
2022年 | 1664篇 |
2021年 | 3478篇 |
2020年 | 5794篇 |
2019年 | 2807篇 |
2018年 | 7752篇 |
2017年 | 7942篇 |
2016年 | 8539篇 |
2015年 | 8686篇 |
2014年 | 11421篇 |
2013年 | 13800篇 |
2012年 | 6352篇 |
2011年 | 6292篇 |
2010年 | 8212篇 |
2009年 | 10319篇 |
2008年 | 5877篇 |
2007年 | 4848篇 |
2006年 | 5960篇 |
2005年 | 4483篇 |
2004年 | 3693篇 |
2003年 | 3120篇 |
2002年 | 2964篇 |
2001年 | 2005篇 |
2000年 | 1299篇 |
1999年 | 1909篇 |
1998年 | 2433篇 |
1997年 | 2177篇 |
1996年 | 2160篇 |
1995年 | 1855篇 |
1994年 | 1264篇 |
1993年 | 1092篇 |
1992年 | 851篇 |
1991年 | 728篇 |
1990年 | 586篇 |
1989年 | 603篇 |
1988年 | 585篇 |
1987年 | 454篇 |
1986年 | 430篇 |
1985年 | 373篇 |
1984年 | 346篇 |
1983年 | 370篇 |
1982年 | 317篇 |
1981年 | 299篇 |
1980年 | 190篇 |
1979年 | 108篇 |
1978年 | 155篇 |
1977年 | 155篇 |
1976年 | 110篇 |
1974年 | 87篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
A convenience sample of hospital workers, those receiving influenza vaccine and those not receiving vaccine, were asked to complete questionnaires delineating the occurrence of symptoms (e.g., fever, headache, extreme tiredness, dry cough, sore throat, runny nose, stuffy nose, muscle aches) and absenteeism in the 7-day period post-vaccination if vaccinated. Those unvaccinated completed the questionnaire in a self-selected 7 consecutive day period during the study conducted from November 2004 to February 2005. Those receiving either Fluzone or FluMist reported significantly fewer symptoms and related absenteeism than the unvaccinated group (p < .05). Administration of influenza vaccine did not result in higher rates of post-vaccination symptoms as compared to an unvaccinated group. Further, vaccinated employees did not experience higher absenteeism rates as a result of receiving either influenza vaccine. However, for those reporting absenteeism as a result of symptoms, mean absenteeism days were highest in the FluMist group (4.5 days) compared to the unvaccinated group (2.1 days) and the Fluzone group (1.9 days). 相似文献
32.
33.
Usher syndrome: clinical findings and gene localization studies 总被引:3,自引:0,他引:3
William J. Kimberling Sandra L. H. Davenport Ira Priluck Valorie White Karen Biscone-Halterman Patrick E. Brookhouser Claes G. Mller Gunnar Lund Timothy J. Grissom Michael D. Weston 《The Laryngoscope》1989,99(1):66-72
The issue of genetic heterogeneity is a critical problem in the localization of the gene(s) for Usher syndrome. Based on the data obtained on families studied to date, the differences between type I and type II Usher syndrome appear quite distinct with regard to auditory and vestibular function. Although the majority of families can be confidently diagnosed as typical type I or type II, clinical investigations revealed four families with findings that did not fit into either of the two more common subtypes. These findings emphasize the critical importance of an in-depth clinical analysis concomitant with the linkage investigation to assure accurate subtyping of Usher syndrome. Based on an analysis of only those families with definite type I or type II Usher syndrome, approximately 17% of the genome can be excluded as a potential site of the gene for type I, and 14% can be excluded as the site for the type II gene. This study will continue until the Usher gene(s) is successfully localized. 相似文献
34.
35.
John P Elliott Hugh S Miller Suzanne Coleman Debbie Rhea Diana Abril Karen Hallbauer Niki B Istwan Gary J Stanziano 《Journal of perinatology》2005,25(10):626-630
OBJECTIVE: To assess the impact of activity restriction (AR) on the incidence of preterm birth in women treated for preterm labor testing negative for fetal fibronectin (fFN). STUDY DESIGN: Women who were diagnosed with preterm labor and tocolyzed with magnesium sulfate were concurrently screened with fFN for the purpose of subsequent management. Included were consenting patients with negative fFN, gestational age 23 0/7-33 6/7 weeks, cervical dilation < or =3 cm, and minimal vaginal bleeding. Patients were randomized to AR or no AR. Primary study outcome was incidence of preterm delivery and interval from randomization to delivery. RESULTS: A total of 73 women with negative fFN were randomized (36 with AR, 37 without AR). The overall preterm birth rate was 40%, with 44.4% of patients with AR and 35.1% of patients without AR delivering preterm, p=0.478. CONCLUSION: Maternal AR did not impact pregnancy outcome. The incidence of preterm birth in symptomatic women testing fFN negative was higher than previously reported. 相似文献
36.
37.
This column contains the presidential address presented during the Third Annual Meeting of the American Association of Heart Failure Nurses on June 28, 2007, in San Diego, California, titled "Building the Foundation of Excellence in Heart Failure Nursing." 相似文献
38.
39.
40.
Robert P. Kusy BS MS PhD 《American journal of orthodontics and dentofacial orthopedics》2004,125(6):726-732
Using an earlier model, which described the critical contact angle for binding from second-order angulation alone, a more generalized model is derived that combines the effects of angulation and torque. From this vantage point, the onset of binding is evaluated for 3 scenarios: second-order angulation alone, third-order torque only, and a combination of second-order angulation and third-order torque. These scenarios are detailed by plotting the critical contact angle for binding against the torque angle as a function of 10 wire dimensions (16 x 16, 16 x 22, 17 x 17, 17 x 22, 17 x 25, 18 x 18, 18 x 22, 18 x 25, 19 x 25, and 21 x 25 mil), 4 bracket widths (70, 100, 130, and 160 mil), and 4 bracket slots (18, 20.5, 22, and 24.5 mil). From these plots, we learn that each wire base dimension (eg, an 18-mil base as found in 18 x 18-mil, 18 x 22-mil and 18 x 25-mil archwires) has a common maximum critical contact angle for binding. Moreover, each wire-slot combination has a common maximum torque angle, which is independent of bracket width. Finally, we learn that archwire-bracket combinations that use a metric 0.5-mm slot might have some advantages with regard to torquing--given the current philosophy that light, continuous forces are more favorable. 相似文献