全文获取类型
收费全文 | 38769篇 |
免费 | 2578篇 |
国内免费 | 97篇 |
专业分类
耳鼻咽喉 | 448篇 |
儿科学 | 1434篇 |
妇产科学 | 945篇 |
基础医学 | 4732篇 |
口腔科学 | 463篇 |
临床医学 | 6458篇 |
内科学 | 6724篇 |
皮肤病学 | 402篇 |
神经病学 | 3724篇 |
特种医学 | 799篇 |
外国民族医学 | 1篇 |
外科学 | 3577篇 |
综合类 | 364篇 |
一般理论 | 49篇 |
预防医学 | 5513篇 |
眼科学 | 403篇 |
药学 | 2368篇 |
中国医学 | 44篇 |
肿瘤学 | 2996篇 |
出版年
2024年 | 30篇 |
2023年 | 323篇 |
2022年 | 450篇 |
2021年 | 847篇 |
2020年 | 602篇 |
2019年 | 938篇 |
2018年 | 1093篇 |
2017年 | 812篇 |
2016年 | 853篇 |
2015年 | 949篇 |
2014年 | 1330篇 |
2013年 | 2097篇 |
2012年 | 3039篇 |
2011年 | 3214篇 |
2010年 | 1713篇 |
2009年 | 1551篇 |
2008年 | 2783篇 |
2007年 | 2795篇 |
2006年 | 2734篇 |
2005年 | 2686篇 |
2004年 | 2477篇 |
2003年 | 2197篇 |
2002年 | 2107篇 |
2001年 | 235篇 |
2000年 | 202篇 |
1999年 | 274篇 |
1998年 | 438篇 |
1997年 | 338篇 |
1996年 | 261篇 |
1995年 | 212篇 |
1994年 | 216篇 |
1993年 | 208篇 |
1992年 | 129篇 |
1991年 | 115篇 |
1990年 | 95篇 |
1989年 | 105篇 |
1988年 | 90篇 |
1987年 | 79篇 |
1986年 | 83篇 |
1985年 | 82篇 |
1984年 | 99篇 |
1983年 | 77篇 |
1982年 | 91篇 |
1981年 | 99篇 |
1980年 | 70篇 |
1979年 | 41篇 |
1978年 | 31篇 |
1977年 | 38篇 |
1976年 | 21篇 |
1975年 | 24篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
32.
33.
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
34.
35.
36.
With the advent of computerized databases, medical data has become easy to accumulate; however, effective use of this data continues to pose significant problems. In other circumstances, smoothing algorithms have been used to uncover non-obvious correlations, trends and relationships in noisy data. We have applied four such algorithms to a large dataset of postoperative blood replacement in cardiopulmonary bypass patients. When applied to this dataset, one of the algorithms proved surprisingly effective. It confirmed several previously observed correlations, and also provided an additional series of counterintuitive and apparently unrelated associations. These associations have been explored in an accompanying paper. 相似文献
37.
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
38.
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
39.
The consequences of alcoholism on the mental health of spouses of lifetime at-risk drinkers are only known from studies on alcoholics already in treatment. A retrospective analysis was conducted using data from a Quebec community health survey. The purpose of this study was twofold. First, our goal was to ascertain the mental health of female spouses living with a male lifetime at-risk drinker. Secondly, we wanted to examine the relationship between male lifetime at-risk drinkers (aged 30-54 years) and the psychological distress of their nondrinking female spouses. Lifetime at-risk drinking, for the purposes of this study, was defined as having at least two positive answers to the CAGE questionnaire. Couples wherein both spouses were deemed not at-risk for problem drinking by the CAGE instrument (0 or 1 positive answer) formed the control group. Psychological distress was measured using the Indice de Détresse Psychologique de l'Enquête Santé Québec (Préville, M., Boyer, R., Potvin, L., Perreault, C., & Légaré, G. (1992). La détresse psychologique: détermination de la fiabilité et de la validité de la mesure utilisée dans l'enquête Santé Québec. Cahier de recherches #7, Montréal, Santé Québec.). It measures symptoms of anxiety, depression, aggressivity, and cognitive impairments. Scores of >or=22 (out of 100) were indicative of a high level of psychological distress. This study confirmed higher levels of psychological distress in female spouses of male lifetime at-risk drinkers in the general population. An exploratory study examined the association between the psychological distress of female spouses and each of the following nine independent variables: male partner lifetime at-risk drinker, stressful life events, job situation, socioeconomic status, perceived health status, presence of children less than 15 years, length of the marital relationship, presence of a confidant, and availability of social support. Lifetime at-risk drinking is a risk factor for the spouse's psychological distress. An examination of the demographic characteristics related to alcohol intake in male lifetime at-risk drinkers is also described in this study. 相似文献
40.
Lesley B Milgrom Jo Ann Brooks Rong Qi Karen Bunnell Susie Wuestfeld Daniel Beckman 《American journal of critical care》2004,13(2):116-125
BACKGROUND: Acute pain is common after cardiac surgery and can keep patients from participating in activities that prevent postoperative complications. Accurate assessment and understanding of pain are vital for providing satisfactory pain control and optimizing recovery. OBJECTIVES: To describe pain levels for 5 activities expected of patients after cardiac surgery on postoperative days 1 to 6 and changes in pain levels after chest tube removal and extubation. METHODS: Adults who underwent cardiac surgery were asked to rate the pain associated with various types of activities on postoperative days 1 to 6. Pain levels were compared by postoperative day, activity, and type of cardiac surgery. Pain scores before and after chest tube removal and extubation also were analyzed. RESULTS: Pain scores were higher on earlier postoperative days. The order of overall pain scores among activities (P < .01) from highest to lowest was coughing, moving or turning in bed, getting up, deep breathing or using the incentive spirometer, and resting. Changes in pain reported with coughing (P = .03) and deep breathing or using the incentive spirometer (P = .005) differed significantly over time between surgery groups. After chest tubes were discontinued, patients had lower pain levels at rest (P = .01), with coughing (P = .05), and when getting up (P = .03). CONCLUSIONS: Pain relief is an important outcome of care. A comprehensive, individualized assessment of pain that incorporates activity levels is necessary to promote satisfactory management of pain. 相似文献