全文获取类型
收费全文 | 130711篇 |
免费 | 31561篇 |
国内免费 | 1154篇 |
专业分类
耳鼻咽喉 | 2775篇 |
儿科学 | 3401篇 |
妇产科学 | 2729篇 |
基础医学 | 6651篇 |
口腔科学 | 5731篇 |
临床医学 | 28817篇 |
内科学 | 31387篇 |
皮肤病学 | 3719篇 |
神经病学 | 15806篇 |
特种医学 | 4866篇 |
外国民族医学 | 3篇 |
外科学 | 23067篇 |
综合类 | 836篇 |
现状与发展 | 40篇 |
一般理论 | 70篇 |
预防医学 | 16235篇 |
眼科学 | 2788篇 |
药学 | 3228篇 |
中国医学 | 30篇 |
肿瘤学 | 11247篇 |
出版年
2024年 | 747篇 |
2023年 | 5100篇 |
2022年 | 1261篇 |
2021年 | 3170篇 |
2020年 | 5543篇 |
2019年 | 2440篇 |
2018年 | 7457篇 |
2017年 | 7707篇 |
2016年 | 8319篇 |
2015年 | 8464篇 |
2014年 | 11174篇 |
2013年 | 13358篇 |
2012年 | 5802篇 |
2011年 | 5706篇 |
2010年 | 7952篇 |
2009年 | 10132篇 |
2008年 | 5593篇 |
2007年 | 4660篇 |
2006年 | 5791篇 |
2005年 | 4511篇 |
2004年 | 3675篇 |
2003年 | 3223篇 |
2002年 | 3147篇 |
2001年 | 2214篇 |
2000年 | 1478篇 |
1999年 | 2086篇 |
1998年 | 2519篇 |
1997年 | 2325篇 |
1996年 | 2327篇 |
1995年 | 2065篇 |
1994年 | 1403篇 |
1993年 | 1199篇 |
1992年 | 1022篇 |
1991年 | 946篇 |
1990年 | 796篇 |
1989年 | 759篇 |
1988年 | 718篇 |
1987年 | 615篇 |
1986年 | 552篇 |
1985年 | 503篇 |
1984年 | 514篇 |
1983年 | 552篇 |
1982年 | 528篇 |
1981年 | 501篇 |
1980年 | 384篇 |
1979年 | 232篇 |
1978年 | 303篇 |
1977年 | 244篇 |
1976年 | 229篇 |
1974年 | 197篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
Priv.-Doz. Dr. Rüdiger Dissmann Joachim Schröder MD PhD Prof. Dr. med. Heinz Völler Prof. Dr. med. Steffen Behrens 《Clinical research in cardiology》2006,95(4):241-243
Summary During pacemaker implantation in a patient with permanent atrial fibrillation, it remained impossible to advance a passive
fixation lead with fins through the right atrium. However, a lead with a retractable screw easily passed the right atrium
and was positioned in the right ventricle. Transesophageal echocardiography revealed an extensive net–like perforated Eustachian
valve within the right atrium that had caused entrapment of the anchor fins during lead implantation. Remnants of embryonal
structures within the right atrium should be considered a rare possible barrier during pacemaker implantation. 相似文献
82.
83.
Bruce D. Cheson 《Seminars in Oncology Nursing》1991,7(4):235-242
The National Cancer Institute (NCI) is the largest single sponsor of studies using anti-neoplastic agents with over 100 compounds currently in various stages of clinical testing. Most of the clinical trials are conducted by the NCI sponsored cooperative oncology groups and community oncology programs, cancer centers, and the pharmaceutical industry. These organizations conduct studies both independently as well as in a collaborative fashion. 相似文献
84.
85.
Laboratory routines cause animal stress. 总被引:8,自引:0,他引:8
Jonathan P Balcombe Neal D Barnard Chad Sandusky 《Contemporary topics in laboratory animal science》2004,43(6):42-51
Eighty published studies were appraised to document the potential stress associated with three routine laboratory procedures commonly performed on animals: handling, blood collection, and orogastric gavage. We defined handling as any non-invasive manipulation occurring as part of routine husbandry, including lifting an animal and cleaning or moving an animal's cage. Significant changes in physiologic parameters correlated with stress (e.g., serum or plasma concentrations of corticosterone, glucose, growth hormone or prolactin, heart rate, blood pressure, and behavior) were associated with all three procedures in multiple species in the studies we examined. The results of these studies demonstrated that animals responded with rapid, pronounced, and statistically significant elevations in stress-related responses for each of the procedures, although handling elicited variable alterations in immune system responses. Changes from baseline or control measures typically ranged from 20% to 100% or more and lasted at least 30 min or longer. We interpret these findings to indicate that laboratory routines are associated with stress, and that animals do not readily habituate to them. The data suggest that significant fear, stress, and possibly distress are predictable consequences of routine laboratory procedures, and that these phenomena have substantial scientific and humane implications for the use of animals in laboratory research. 相似文献
86.
During much of the past century, the microbe itself stood at the heart of microbial pathogenesis. Little thought was devoted
to the host per se, though it was granted that differences in susceptibility to certain infections did exist between individuals,
and between different ethnic groups. During the past 20 years, extraordinary strides in our grasp of mammalian genetics have
made the host side of the equation far more approachable. A restricted collection of genes now presents itself as the likely
repository for genetic differences that foretell susceptibility to infectious disease. The Toll-like receptors, of which 10
are presently known to exist in humans, offer an excellent example of this genetic reductionism, in that they embody the afferent
component of the innate immune system, and strongly influence the containment of an infection from its earliest stages. The
Toll-like receptors were identified as the culmination of a long and relentless inquiry into the yet-unsolved clinical problem
of sepsis. 相似文献
87.
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
88.
89.
Neal G Palmer James R Yacyshyn Herbert C Northcott Brian Nebbe Paul W Major 《American journal of orthodontics and dentofacial orthopedics》2005,128(2):163-167
INTRODUCTION: To plan for future acceptance and implementation of computer-related technology, it is necessary to understand orthodontists' current perceptions and attitudes toward emerging technologies. METHODS: An anonymous, self-administered, mail-out survey of Canadian orthodontists was conducted. The response rate was 45.6% (304/667). RESULTS: Most orthodontists indicated that computer technology could improve current practice efficiency and quality of patient care. Only 15% reported that digital models are quite or very useful; 73.6%, 69.1%, 55%, and 37.4% agreed or strongly agreed with using digital and electronic technology to consult with other dental specialists, other orthodontists, general dentists, and the public, respectively. Cost of the technology was reported as a significant or insurmountable obstacle by 54% of the respondents. Interprovincial legislation, unclear consultation remuneration guidelines, and lack of comfort with the technology were not perceived as significant obstacles. Only 36% reported security or privacy issues as a significant or insurmountable obstacle. CONCLUSIONS: Canadian orthodontists seem to view digital and electronic technology as useful and capable of improving their offices' efficiency and production. Although they are sensitive to some potential obstacles, they are willing to overcome these and incorporate the technology into their practices. 相似文献
90.
Single parent women 总被引:1,自引:1,他引:0
Myrna M. Weissman Philip J. Leaf Martha Livingston Bruce 《Social psychiatry and psychiatric epidemiology》1987,22(1):29-36
Summary While there has been considerable interest in the problems of single parent families, no study has yet determined if the problems are due to increased risk of specific psychiatric disorders in single parents as compared to their married counterparts. Data collected as part of the National Institute of Mental Health Epidemiologic Catchment Area (ECA) Project are presented to compare the psychiatric as well as economic and social functioning of single vs. married parent women ages 18–44, based on a probability sample of members of the greater New Haven community. The major finding between groups is their relative similarity in psychiatric as well as social functioning. The major difference is economic. Single parents, both Black and White, more frequently are less educated and poorer. While many are on welfare, single compared to married female parents are more likely to be working and to report insufficient income to meet their needs. There are no appreciable differences in social contacts, use of health services or six-month prevalence rates of psychiatric disorders including major depression, alcohol or drug abuse. The data suggest that the problems faced by single parent women and their children may be a reflection of poverty and stress in families and not of psychiatric disorders or poor social relations in mothers. 相似文献