全文获取类型
收费全文 | 2807篇 |
免费 | 253篇 |
国内免费 | 12篇 |
专业分类
耳鼻咽喉 | 15篇 |
儿科学 | 185篇 |
妇产科学 | 120篇 |
基础医学 | 390篇 |
口腔科学 | 52篇 |
临床医学 | 327篇 |
内科学 | 506篇 |
皮肤病学 | 28篇 |
神经病学 | 204篇 |
特种医学 | 335篇 |
外科学 | 300篇 |
综合类 | 81篇 |
预防医学 | 223篇 |
眼科学 | 23篇 |
药学 | 155篇 |
肿瘤学 | 128篇 |
出版年
2021年 | 29篇 |
2020年 | 20篇 |
2019年 | 27篇 |
2018年 | 48篇 |
2017年 | 20篇 |
2016年 | 28篇 |
2015年 | 46篇 |
2014年 | 57篇 |
2013年 | 79篇 |
2012年 | 104篇 |
2011年 | 112篇 |
2010年 | 89篇 |
2009年 | 79篇 |
2008年 | 71篇 |
2007年 | 113篇 |
2006年 | 111篇 |
2005年 | 105篇 |
2004年 | 88篇 |
2003年 | 69篇 |
2002年 | 67篇 |
2001年 | 73篇 |
2000年 | 64篇 |
1999年 | 78篇 |
1998年 | 106篇 |
1997年 | 87篇 |
1996年 | 99篇 |
1995年 | 70篇 |
1994年 | 64篇 |
1993年 | 75篇 |
1992年 | 50篇 |
1991年 | 57篇 |
1990年 | 45篇 |
1989年 | 62篇 |
1988年 | 52篇 |
1987年 | 72篇 |
1986年 | 55篇 |
1985年 | 58篇 |
1984年 | 55篇 |
1983年 | 35篇 |
1982年 | 42篇 |
1981年 | 34篇 |
1980年 | 42篇 |
1979年 | 19篇 |
1978年 | 29篇 |
1977年 | 29篇 |
1976年 | 28篇 |
1975年 | 21篇 |
1973年 | 15篇 |
1972年 | 20篇 |
1971年 | 23篇 |
排序方式: 共有3072条查询结果,搜索用时 15 毫秒
981.
France EK Smith-Ray R McClure D Hambidge S Xu S Yamasaki K Shay D Weintraub E Fry AM Black SB Shinefield HR Mullooly JP Jackson LA 《Archives of pediatrics & adolescent medicine》2006,160(12):1277-1283
OBJECTIVE: To determine whether influenza vaccination of pregnant women prevents visits for respiratory illness in their infants born during the influenza season. DESIGN: Retrospective matched cohort study. SETTING: Four managed care organizations in the United States. Patients A total of 41 129 infants (3160 and 37 969 born to vaccinated and unvaccinated mothers, respectively) born between 1995 and 2001. Main Exposure Maternal influenza vaccination. Infants were considered exposed if their gestational age at birth was at least 30 weeks, if the time from maternal vaccination to birth was at least 28 days, and if they were exposed to at least 14 days of the influenza season. MAIN OUTCOME MEASURES: Incidence of acute respiratory illnesses (outpatient, emergency department, and inpatient settings combined) and incident rate ratios (IRRs) for infants exposed and unexposed to maternal vaccination during the following 4 periods: peak influenza, respiratory syncytial virus predominant, periseasonal, and summer weeks. The time to the first acute respiratory illness during peak influenza weeks was also assessed. RESULTS: During the peak influenza weeks, infant visit rates were 15.4 and 17.1 per 100 person-months for exposed and unexposed infants, respectively (IRR, 0.90; 95% confidence interval, 0.80-1.02). Adjusted IRRs for the 4 periods found a protective effect of infant female sex, whereas Medicaid status and maternal high-risk status increased infant visit rates. Maternal influenza vaccination did not reduce visit rates during any of the 4 time periods (IRR for peak influenza season, 0.96; 95% confidence interval, 0.86-1.07) and did not delay the onset of first respiratory illness. CONCLUSION: We were unable to demonstrate that maternal influenza vaccination reduces respiratory illness visit rates among their infants. 相似文献
982.
Engaging staff nurses in evidence-based research to identify nursing practice problems and solutions
Peri Rosenfeld Elizabeth Duthie Jacqueline Bier Susan Bowar-Ferres Terry Fulmer Linda Iervolino Margaret L. McClure Diane O. McGivern Marianne Roncoli 《Applied Nursing Research》2000,13(4):197-203
This article illustrates how one academic health science center in a large metropolitan area sought to improve the quality of patient care by soliciting the input of their nursing staff in devising an action plan for change. The research model incorporated both survey and focus group methods used by nursing leaders in administration and practice to identify and prioritize nursing research and clinical needs in their organization. The goal was to establish consensus among clinicians and researchers about significant issues in the institution requiring in-depth attention. A second objective was to design a survey instrument that is easy to complete and could be distributed, collected, and analyzed easily, thereby providing empirical data to the clinicians in a timely manner and in a simple format. This expedited process enabled specific action plans to be developed around the identified problems. Moreover, the process promoted interest in advancing nursing research and evidence-based practice among the clinicians and administrators. 相似文献
983.
Objective Psychomotor Skills Assessment of Experienced, Junior,
and Novice Laparoscopists with Virtual Reality 总被引:22,自引:1,他引:21
Anthony G. Gallagher Ph.D. Karen Richie B.Sc. Neil McClure M.D. Jim McGuigan 《World journal of surgery》2001,25(11):1478-1483
Objective assessment of psychomotor
skills in surgery is now a priority; however, this assessment is
difficult to achieve because of measurement difficulties associated
with the reliability and validity of assessing surgical skills in vivo
and in the laboratory. In this study virtual reality (VR) was used to
overcome these problems in the objective psychomotor assessment of
senior, junior, and novice laparoscopists. Twelve experienced
laparoscopic surgeons (performed >50 Minimal Access Surgery (MAS)
procedures), 12 inexperienced laparoscopic surgeons (<10 MAS
procedures), and 12 laparoscopic novices (no MAS procedures)
participated in the study. Each subject completed all six tasks of the
Minimally Invasive Surgical Trainer; Virtual Reality (MIST VR). In
comparison to the other groups, experienced laparoscopic surgeons
performed the tasks significantly (p < 0.01) faster,
had a lower error rate, were more economic in their movement of
surgical instruments and in the use of diathermy. As a group they also
showed greater consistency in their performance. MIST VR distinguished
between the three groups of laparoscopists. VR provides a useful
objective assessment tool for evaluating psychomotor skills for
laparoscopic surgery. 相似文献
984.
985.
986.
Hila Renee Lutz Kelly McClure Sharon Armstrong 《Journal of child & adolescent substance abuse》2017,26(3):229-241
Social problem solving has been associated with alcohol use in adolescents, but has not been examined within the context of well-established risk factors, such as childhood conduct problems, parental history of alcohol use, association with deviant peers, and behavior undercontrol. This study surveyed 120, 18-year-old first-year college students to examine whether poor social problem solving is a risk factor for adolescent alcohol use above and beyond the other well-established risk factors and to examine whether social problem solving is a moderator between behavior undercontrol and alcohol use in adolescents. Hierarchical multiple regressions found that social problem solving was not a significant risk factor above and beyond well-established risk factors for adolescent alcohol use. Furthermore, social problem solving was not a significant moderator between behavior undercontrol and adolescent alcohol use. The results also indicated that association with deviant peers and family income accounted for significant variance in adolescent alcohol use, suggesting association with deviant peers and family income are the risk factors that are most strongly related to adolescent alcohol use. 相似文献
987.
988.
989.
990.
The t(9;22) in chronic myelogenous leukemia (CML) may be reciprocal or, in a minority of cases, may result in an extensive deletion of a portion of the major breakpoint cluster region (M-bcr) of the BCR. This report provides evidence of the duplication of small segments within the M-bcr in a small group of patients with CML. Southern blots of Bgl II and Bgl II/BamHI double-digested DNA from the blood or bone marrow of 46 patients with CML were probed with a 5' 1.4-kb Taq I/HindIII M- bcr probe and a 3' 2-kb HindIII/BamHI M-bcr probe. In three patients, rearrangements were noted with both probes in Bgl II-digested DNA, but were not present in Bgl II/BamHI-digested DNA with either probe. Southern analysis of DNA samples double-digested with Bgl II and BspHI from two of these three cases showed no rearrangements with either probe; the M-bcr BspHI site is located 26 bp 3' of the BamHI site in the second intron of the M-bcr. The presence of a rearranged M-bcr with both probes in Bgl II-digested DNA and the lack of rearrangement in Bgl II/BamHI and Bgl II/BspHI double-digested DNA suggest the presence of M- bcr BamHI and BspHI sites on both 9q+ chromosome (9q+) and the Philadelphia chromosome (Ph). This implies a duplication of at least the 26-bp M-bcr BamHI/BspHI fragment in these two samples. Sequence data from one of these two cases confirmed the M-bcr breakpoints to be staggered; the Ph M-bcr breakpoint occurred 258 bp downstream from the 9q+ M-bcr breakpoint. It is concluded that a duplication of small segments within the M-bcr occurs in a small group of patients with CML, which may lead to pseudogermline patterns on Southern blot. Such a duplication may provide insight into the mechanism of some chromosomal translocations in neoplasia. 相似文献