全文获取类型
收费全文 | 3434902篇 |
免费 | 286299篇 |
国内免费 | 13300篇 |
专业分类
耳鼻咽喉 | 46887篇 |
儿科学 | 109099篇 |
妇产科学 | 89333篇 |
基础医学 | 547863篇 |
口腔科学 | 92894篇 |
临床医学 | 313407篇 |
内科学 | 606947篇 |
皮肤病学 | 91273篇 |
神经病学 | 293960篇 |
特种医学 | 134118篇 |
外国民族医学 | 291篇 |
外科学 | 524638篇 |
综合类 | 102280篇 |
现状与发展 | 24篇 |
一般理论 | 2361篇 |
预防医学 | 294481篇 |
眼科学 | 78153篇 |
药学 | 235170篇 |
26篇 | |
中国医学 | 9345篇 |
肿瘤学 | 161951篇 |
出版年
2021年 | 54885篇 |
2020年 | 35006篇 |
2019年 | 57924篇 |
2018年 | 71185篇 |
2017年 | 54267篇 |
2016年 | 59715篇 |
2015年 | 73875篇 |
2014年 | 107955篇 |
2013年 | 173092篇 |
2012年 | 93832篇 |
2011年 | 94333篇 |
2010年 | 116867篇 |
2009年 | 121212篇 |
2008年 | 81553篇 |
2007年 | 85038篇 |
2006年 | 94926篇 |
2005年 | 90638篇 |
2004年 | 92234篇 |
2003年 | 83008篇 |
2002年 | 72829篇 |
2001年 | 102537篇 |
2000年 | 95192篇 |
1999年 | 95245篇 |
1998年 | 64548篇 |
1997年 | 62616篇 |
1996年 | 60771篇 |
1995年 | 56198篇 |
1994年 | 50460篇 |
1993年 | 47129篇 |
1992年 | 67577篇 |
1991年 | 64828篇 |
1990年 | 61456篇 |
1989年 | 60627篇 |
1988年 | 56466篇 |
1987年 | 55232篇 |
1986年 | 52660篇 |
1985年 | 52237篇 |
1984年 | 48170篇 |
1983年 | 44354篇 |
1982年 | 41720篇 |
1981年 | 39438篇 |
1980年 | 37165篇 |
1979年 | 40665篇 |
1978年 | 36266篇 |
1977年 | 32843篇 |
1976年 | 30130篇 |
1975年 | 29017篇 |
1974年 | 30492篇 |
1973年 | 29608篇 |
1972年 | 27860篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
991.
992.
Jennifer L. Brown Lisa B. Haddad Nicole K. Gause Sarah Cordes Cecilia Bess Caroline C. King 《Women & health》2019,59(3):305-317
This study qualitatively examined factors that influenced contraceptive choices in a sample of young, HIV-infected women. Individual qualitative interviews were conducted among 30 vertically and horizontally HIV-infected women (n = 26 African American) from the ages of 14 to 24 years (Mean age = 20.9 years). We recruited sample groups with the following characteristics: (a) current contraceptive/condom use with ≥1 child (n = 11); (b) current contraceptive/condom use with no children (n = 12); and (c) no current contraceptive/condom use with no children (n = 7). A semi-structured interview guide was used to ask participants about factors influencing past and current contraceptive choices. Individual interviews were digitally recorded and transcribed verbatim; analyses to identify core themes were informed by the Grounded Theoretical approach. Young, HIV-infected women did not identify their HIV serostatus or disease-related concerns as influential in their contraceptive decisions. However, they reported that recommendations from health-care providers and input from family and friends influenced their contraceptive choices. They also considered a particular method’s advantages (e.g., menstrual cycle improvements) and disadvantages (e.g., increased pill burden) when selecting a method. Findings suggested that HIV-infected young women’s contraceptive decisions were influenced by factors other than those related to their infection. 相似文献
993.
Jusleen Ahluwalia Allison Han Ayan Kusari Lawrence F. Eichenfield 《Pediatric dermatology》2019,36(6):808-814
Recurrent herpes labialis (RHL) is an incredibly common condition, though the medical literature evaluating pediatric aspects is limited. This paper assesses prevalence and therapeutic studies of pediatric RHL as well as disease complications. A comprehensive literature search of English‐language citations based on PubMed queries of selected terms was performed, with exclusion if methodology was not discussed, or if studies had 10 or fewer patients. RHL prevalence in pediatrics has been assessed by measures of point and periodic prevalence, though methodologic limitations may under‐ or over‐estimate the true prevalence of RHL. Studies have been conducted to evaluate therapeutic safety, tolerability, and efficacy of antivirals in the pediatric population. Pediatric RHL point prevalence ranges from 0.72% to 5.2% depending on the population study and the methodologies used. Pediatric RHL carries a significant public health burden and is often implicated in patients with eczema herpeticum, erythema multiforme, reactive infectious mucositis eruptions, and hypersensitivity reactions. There are few studies that evaluate the rates of occurrence of these sequelae associated with pediatric RHL. 相似文献
994.
Emmi Helle Aldo Córdova-Palomera Tiina Ojala Priyanka Saha Praneetha Potiny Stefan Gustafsson Erik Ingelsson Michael Bamshad Deborah Nickerson Jessica X. Chong University of Washington Center for Mendelian Genomics Euan Ashley James R. Priest 《Genetic epidemiology》2019,43(2):215-226
Loss of function variants in NOTCH1 cause left ventricular outflow tract obstructive defects (LVOTO). However, the risk conferred by rare and noncoding variants in NOTCH1 for LVOTO remains largely uncharacterized. In a cohort of 49 families affected by hypoplastic left heart syndrome, a severe form of LVOTO, we discovered predicted loss of function NOTCH1 variants in 6% of individuals. Rare or low-frequency missense variants were found in 16% of families. To make a quantitative estimate of the genetic risk posed by variants in NOTCH1 for LVOTO, we studied associations of 400 coding and noncoding variants in NOTCH1 in 1,085 cases and 332,788 controls from the UK Biobank. Two rare intronic variants in strong linkage disequilibrium displayed significant association with risk for LVOTO amongst European-ancestry individuals. This result was replicated in an independent analysis of 210 cases and 68,762 controls of non-European and mixed ancestry. In conclusion, carrying rare predicted loss of function variants in NOTCH1 confer significant risk for LVOTO. In addition, the two intronic variants seem to be associated with an increased risk for these defects. Our approach demonstrates the utility of population-based data sets in quantifying the specific risk of individual variants for disease-related phenotypes. 相似文献
995.
Peter Marhofer Malachy Columb Phil M. Hopkins Manfred Greher Daniela Marhofer Max R. Levi Bienzle Markus Zeitlinger 《British journal of anaesthesia》2019,122(4):525-531
Background
The efficacy of dexamethasone in extending the duration of local anaesthetic block is uncertain. In a randomised controlled triple blind crossover study in volunteers, we tested the hypothesis that neither i.v. nor perineurally administered dexamethasone prolongs the sensory block achieved with ropivacaine.Methods
Ultrasound-guided ulnar nerve blocks (ropivacaine 0.75% wt/vol, 3 ml, with saline 1 ml with or without dexamethasone 4 mg) were performed on three occasions in 24 male volunteers along with an i.v. injection of saline 1 ml with or without dexamethasone 4 mg. The combinations of saline and dexamethasone were as follows: control group, perineural and i.v. saline; perineural group, perineural dexamethasone and i.v. saline; i.v. group, perineural saline and i.v. dexamethasone. Sensory block was measured using a VAS in response to pinprick testing. The duration of sensory block was the primary outcome and time to onset of sensory block the secondary outcome.Results
All 24 subjects completed the trial. The median [inter-quartile range (IQR)] duration of sensory block was 6.87 (5.85–7.62) h in the control group, 7.37 (5.78–7.93) h in the perineural group and 7.37 (6.10–7.97) h in the i.v. group (P=0.61). There was also no significant difference in block onset time between the three groups.Conclusion
Dexamethasone 4 mg has no clinically relevant effect on the duration of sensory block provided by ropivacaine applied to the ulnar nerve.Clinical trial registration
DRKS, 00014604; EudraCT, 2018-001221-98. 相似文献996.
997.
998.
999.
1000.