全文获取类型
收费全文 | 61742篇 |
免费 | 4280篇 |
国内免费 | 214篇 |
专业分类
耳鼻咽喉 | 572篇 |
儿科学 | 2061篇 |
妇产科学 | 1474篇 |
基础医学 | 8466篇 |
口腔科学 | 887篇 |
临床医学 | 5924篇 |
内科学 | 13622篇 |
皮肤病学 | 1416篇 |
神经病学 | 6581篇 |
特种医学 | 1472篇 |
外国民族医学 | 1篇 |
外科学 | 6780篇 |
综合类 | 469篇 |
一般理论 | 61篇 |
预防医学 | 7172篇 |
眼科学 | 933篇 |
药学 | 3809篇 |
中国医学 | 166篇 |
肿瘤学 | 4370篇 |
出版年
2024年 | 45篇 |
2023年 | 672篇 |
2022年 | 925篇 |
2021年 | 2502篇 |
2020年 | 1433篇 |
2019年 | 2144篇 |
2018年 | 2692篇 |
2017年 | 1713篇 |
2016年 | 1789篇 |
2015年 | 1997篇 |
2014年 | 2368篇 |
2013年 | 3199篇 |
2012年 | 5169篇 |
2011年 | 5304篇 |
2010年 | 2658篇 |
2009年 | 2254篇 |
2008年 | 3904篇 |
2007年 | 3943篇 |
2006年 | 3780篇 |
2005年 | 3648篇 |
2004年 | 3155篇 |
2003年 | 2920篇 |
2002年 | 2498篇 |
2001年 | 820篇 |
2000年 | 805篇 |
1999年 | 696篇 |
1998年 | 419篇 |
1997年 | 298篇 |
1996年 | 250篇 |
1995年 | 213篇 |
1994年 | 148篇 |
1993年 | 130篇 |
1992年 | 220篇 |
1991年 | 222篇 |
1990年 | 157篇 |
1989年 | 152篇 |
1988年 | 126篇 |
1987年 | 102篇 |
1986年 | 98篇 |
1985年 | 97篇 |
1984年 | 85篇 |
1983年 | 65篇 |
1982年 | 34篇 |
1981年 | 47篇 |
1980年 | 31篇 |
1979年 | 43篇 |
1978年 | 29篇 |
1977年 | 38篇 |
1974年 | 20篇 |
1973年 | 32篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
131.
132.
R Matorras J Diez M Saez F Montoya G Aranguren F J Rodríguez-Escudero 《International journal of gynaecology and obstetrics》1991,36(4):323-327
Two pregnancies in a patient with a fixed-rate pacemaker are reported. The first pregnancy was uneventful. The second had no maternal complications either. A moderate tachysystolia was detected during the second period. The newborn was delivered with forceps applied under spinal anesthesia. Newborn infant evolution presented no hazards, but umbilical cord analysis revealed a severe acidosis, in spite of a normal scalp analysis 45 min earlier. Epidural anesthesia is recommended for such patients. 相似文献
133.
134.
Laura K Brennan Elizabeth A Baker Debra Haire-Joshu Ross C Brownson 《Health education & behavior》2003,30(6):740-755
Although the relationship of psychosocial factors to physical activity has been explored, there is increased interest in how perceptions of the community environment influence behavior. However, few methodological studies have incorporated perceptions of the social and community environment (protective social factors) or addressed key measurement issues. Computer-assisted telephone interviews were administered to a national sample of 1,818 U.S. adults. Unadjusted and multivariate-adjusted odds ratios were calculated to compare active and inactive participants by Protective Social Factors (PSF) scores and selected sociodemographics. Confirmatory factor analysis and reliability analysis suggested strong PSF scale psychometric properties (alpha = .92). After adjustment for potential confounders, a 10-point rise in the PSF score resulted in a 12% increased likelihood of meeting Centers for Disease Control and Prevention/American College of Sports Medicine recommendations. Additional analyses indicated that greater perceived PSFs were associated with meeting these recommendations among Whites but not among African Americans. 相似文献
135.
Laura Emmons Patricia Callahan Phyllis Gorman Marcia Snyder 《Journal of Midwifery & Women's Health》1997,42(3):228-253
This article describes the clinical management of dermatologic disorders most commonly encountered in the primary care setting. The common presenting clinical signs and symptoms are reviewed, and the initial laboratory tests that may establish the diagnosis are recommended. Pharmacologic and nonpharmacologic treatments are reviewed. Diagnosis and management of disorders of the sebaceous and apocrine glands, disorders of the hair and pigmentation, fungal, viral, and bacterial infections, dermatitis, and infestations are discussed. A review of the care of skin burns and wounds is included as well as the diagnosis and management of urticaria. 相似文献
136.
Philip Harber Laura Pea Paul Hsu Elizabeth Billet Deborah Greer Katty Kim 《American journal of industrial medicine》1994,25(4):519-526
Back pain among nurses is a common problem. Prior studies of this problem have been based on cross-sectional or retrospective data. This 18-month prospective study involving nurses newly graduated from nursing school investigated personal, worksite, and training factors associated with future risk of back pain. Each nurse underwent a preliminary interview and periodic follow-ups to identify those with back injuries. Contingency tables and logistic regression analyses demonstrated that prior significant back pain episodes (evidenced by previous job changes because of back pain, frequent medication use, etc.) were associated with increased future risk. Training at nursing school or on the job did not have a protective effect. This pilot study therefore suggests factors useful in placement and counseling of new nurses and indicates the need for further implementation of mechanical lift assist device use. © 1994 Wiley-Liss, Inc. 相似文献
137.
Mapping of α- and β-globin genes on Antarctic fish chromosomes by fluorescence in-situ hybridization
Eva Pisano Ennio Cocca Federico Mazzei Laura Ghigliotti Guido di Prisco H. William Detrich III Catherine Ozouf-Costaz 《Chromosome research》2003,11(6):633-640
The pathways and mechanisms of genomic change that have led to the peculiar haemoglobinless phenotype of the white-blooded
Antarctic icefishes (16 species in the family Channichthyidae) constitute an important model for understanding the rapid diversification
of the Antarctic notothenioid fish flock. To provide complementary structural information on genomic change at globin-gene
loci in Antarctic fish species, cytogenetic studies and in-situ chromosomal mapping have been undertaken. Using a DNA probe containing one α- and one β-globin gene from the embryonic/juvenile
globin gene cluster of the red-blooded species Notothenia coriiceps, we mapped the cluster on the chromosomes of Antarctic teleosts by fluorescence in-situ hybridization. As anticipated on the basis of its molecular organization, the cluster was located on a single chromosome
pair in all of the red-blooded fish species probed (N. coriiceps, N. angustata, Trematomus hansoni, T. pennellii). In contrast, the α/β-globin probe did not recognize complementary sequences on the chromosomes of the white-blooded species
Chionodraco hamatus and Channichthys rhinoceratus. These results represent the first example of chromosomal mapping of embryonic/juvenile globin genes in teleostean fishes.
Beyond its relevance to the evolutionary history of Antarctic notothenioids, this work contributes to our understanding of
the evolution of the chromosomal loci of globin genes in fishes and other vertebrates.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
138.
Angelo Pan Placido Mondello Klara Posfay-Barbe Patrizia Catenazzi Annise Grandi Silvia Lorenzotti Andrea Patroni Nadia Poli Laura Soavi Giuseppe Carnevale 《Infection control and hospital epidemiology》2007,28(9):1099-1102
In an Italian hospital, we observed that hand hygiene was performed in 638 (19.6%) of 3,253 opportunities, whereas gloves were worn in 538 (44.2%) 1,218 of opportunities. We observed an inverse correlation between the intensity of care and the rate of hand hygiene compliance (R2=0.057; P<.001), but no such association was observed for the rate of glove use compliance (R2=0.014; P=.078). Rates of compliance with hand hygiene and glove use recommendations follow different behavioral patterns. 相似文献
139.
140.
David H. Howard Laura A. Siminoff Virginia McBride Monica Lin 《Health services research》2007,42(6P1):2160-2173
Objective. The Organ Donation Breakthrough Collaborative is a quality improvement initiative to encourage adoption of "best practices" for identifying potential donors and obtaining consent for deceased organ donation. We evaluate the impact of the first phase on organ donation rates.
Setting. We study donation rates in the 95 hospitals that participated in the first phase and a control group of 125 hospitals.
Design. We use a controlled pre/post design. The preperiod is the year before the start of the Collaborative (September 2002 to August 2003), the postperiod is the final 6 months of the first phase (March 2004 to August 2004).
Data. We use administrative data from the Organ Procurement and Transplantation Network to compute the conversion rate in each hospital group and time period. The conversion rate is the proportion of eligible donors who became actual donors.
Principal Findings. Preperiod conversion rates in Collaborative and control hospitals were similar: 52 and 51 percent, respectively. In the postperiod, the conversion rate increased to 60 percent among Collaborative hospitals and remained at 51 percent among control hospitals. The relative change was 8 percentage points (95 percent confidence interval: 2–13: p <.001).
Conclusions. Our findings suggest that the Breakthrough Collaborative led to an increase in donation rates at participating hospitals. 相似文献
Setting. We study donation rates in the 95 hospitals that participated in the first phase and a control group of 125 hospitals.
Design. We use a controlled pre/post design. The preperiod is the year before the start of the Collaborative (September 2002 to August 2003), the postperiod is the final 6 months of the first phase (March 2004 to August 2004).
Data. We use administrative data from the Organ Procurement and Transplantation Network to compute the conversion rate in each hospital group and time period. The conversion rate is the proportion of eligible donors who became actual donors.
Principal Findings. Preperiod conversion rates in Collaborative and control hospitals were similar: 52 and 51 percent, respectively. In the postperiod, the conversion rate increased to 60 percent among Collaborative hospitals and remained at 51 percent among control hospitals. The relative change was 8 percentage points (95 percent confidence interval: 2–13: p <.001).
Conclusions. Our findings suggest that the Breakthrough Collaborative led to an increase in donation rates at participating hospitals. 相似文献