全文获取类型
收费全文 | 2670篇 |
免费 | 137篇 |
国内免费 | 7篇 |
专业分类
耳鼻咽喉 | 22篇 |
儿科学 | 70篇 |
妇产科学 | 82篇 |
基础医学 | 368篇 |
口腔科学 | 104篇 |
临床医学 | 233篇 |
内科学 | 531篇 |
皮肤病学 | 63篇 |
神经病学 | 182篇 |
特种医学 | 159篇 |
外科学 | 270篇 |
综合类 | 29篇 |
一般理论 | 1篇 |
预防医学 | 178篇 |
眼科学 | 60篇 |
药学 | 140篇 |
中国医学 | 2篇 |
肿瘤学 | 320篇 |
出版年
2023年 | 11篇 |
2022年 | 18篇 |
2021年 | 39篇 |
2020年 | 31篇 |
2019年 | 44篇 |
2018年 | 45篇 |
2017年 | 40篇 |
2016年 | 50篇 |
2015年 | 45篇 |
2014年 | 79篇 |
2013年 | 129篇 |
2012年 | 143篇 |
2011年 | 163篇 |
2010年 | 115篇 |
2009年 | 97篇 |
2008年 | 169篇 |
2007年 | 152篇 |
2006年 | 149篇 |
2005年 | 169篇 |
2004年 | 167篇 |
2003年 | 138篇 |
2002年 | 129篇 |
2001年 | 49篇 |
2000年 | 30篇 |
1999年 | 41篇 |
1998年 | 31篇 |
1997年 | 31篇 |
1996年 | 19篇 |
1995年 | 16篇 |
1994年 | 16篇 |
1993年 | 19篇 |
1992年 | 21篇 |
1991年 | 20篇 |
1990年 | 28篇 |
1989年 | 26篇 |
1988年 | 20篇 |
1987年 | 20篇 |
1986年 | 21篇 |
1985年 | 20篇 |
1984年 | 32篇 |
1983年 | 22篇 |
1982年 | 14篇 |
1981年 | 16篇 |
1979年 | 13篇 |
1978年 | 11篇 |
1977年 | 13篇 |
1976年 | 16篇 |
1975年 | 15篇 |
1971年 | 10篇 |
1970年 | 9篇 |
排序方式: 共有2814条查询结果,搜索用时 31 毫秒
1.
2.
3.
4.
National Programme of Research in Human Reproduction S.K. Banerjee R. Baveja R.V. Bhatt A. Chatterjee S.D. Choudhury B. Coyaji A.D. Engineer M.P. Gogoi V. Hingorani K. Lal M. Kochhar U. Krishna P. Misra F.S. Philips R. Rajan P.C. Sen Gupta K. Zaveri S. Datey S. Gupta S. Mehta N.C. Saxena B.N. Saxena 《Contraception》1986,34(6):573-582
The return of fertility following discontinuation of norethisterone oenanthate (NET EN) 200 mg injectable contraceptive after use for a minimum period of six months or more was studied in 69 women who discontinued the method for planning pregnancy. Former users of copper intra-uterine device (CuT 200) were enrolled as a control group. Another 161 women who had discontinued NET EN due to other reasons (e.g. amenorrhoea, excessive bleeding or personal reasons) were also studied for return of fertility after ensuring that they were not using any other method of contraception and were exposed to the risk of pregnancy. The subjects from both groups were followed for a period of one year. The cumulative conception rates at one year were 72.5 and 83.6 per 100 subjects for ex-NET EN and ex-CuT 200 users who had discontinued the method for planning pregnancy and this difference was not statistically significant (P > 0.05). The median time for conception for ex-NET EN users was 7.8 months as compared to 3.7 months in ex-CuT 200 users but the cumulative conception rates at the end of one year show that future return of fertility in NET EN users does not appear to be adversely affected.
In 51 subjects who had discontinued NET EN due to amenorrhoea, the return of fertility was predictably slower and less. The return of fertility in subjects who discontinued NET EN for other reasons (e.g. excessive bleeding and other personal reasons) was similar to ex-NET EN and ex-CuT 200 users. 相似文献
5.
Strahlentherapie und Onkologie - 相似文献
6.
Genetic predisposition for adult lactose intolerance and relation to diet, bone density, and bone fractures. 总被引:8,自引:0,他引:8
Barbara M Obermayer-Pietsch Christine M Bonelli Daniela E Walter Regina J Kuhn Astrid Fahrleitner-Pammer Andrea Berghold Walter Goessler Vinzenz Stepan Harald Dobnig Georg Leb Wilfried Renner 《Journal of bone and mineral research》2004,19(1):42-47
Evidence that genetic disposition for adult lactose intolerance significantly affects calcium intake, bone density, and fractures in postmenopausal women is presented. PCR-based genotyping of lactase gene polymorphisms may complement diagnostic procedures to identify persons at risk for both lactose malabsorption and osteoporosis. INTRODUCTION: Lactase deficiency is a common autosomal recessive condition resulting in decreased intestinal lactose degradation. A -13910 T/C dimorphism (LCT) near the lactase phlorizin hydrolase gene, reported to be strongly associated with adult lactase nonpersistence, may have an impact on calcium supply, bone density, and osteoporotic fractures in the elderly. MATERIALS AND METHODS: We determined LCT genotypes TT, TC, and CC in 258 postmenopausal women using a polymerase chain reaction-based assay. Genotypes were related to milk intolerance, nutritional calcium intake, intestinal calcium absorption, bone mineral density (BMD), and nonvertebral fractures. RESULTS: Twenty-four percent of all women were found to have CC genotypes and genetic lactase deficiency. Age-adjusted BMD at the hip in CC genotypes and at the spine in CC and TC genotypes was reduced by -7% to -11% depending on the site measured (p = 0.04). LCT(T/C-13910) polymorphisms alone accounted for 2-4% of BMD in a multiple regression model. Bone fracture incidence was significantly associated with CC genotypes (p = 0.001). Milk calcium intake was significantly lower (-55%, p = 0.004) and aversion to milk consumption was significantly higher (+166%, p = 0.01) in women with the CC genotype, but there were no differences in overall dietary calcium intake or in intestinal calcium absorption test values. CONCLUSION: The LCT(T/C-13910) polymorphism is associated with subjective milk intolerance, reduced milk calcium intake, and reduced BMD at the hip and the lumbar spine and may predispose to bone fractures. Genetic testing for lactase deficiency may complement indirect methods in the detection of individuals at risk for both lactose malabsorption and osteoporosis. 相似文献
7.
8.
9.
Lieve Peremans Veronique Verhoeven Hilde Philips Joke Denekens Paul Van Royen 《The European journal of contraception & reproductive health care》2007,12(4):317-325
OBJECTIVE: To evaluate how Belgian health care providers deal with a request for emergency contraception. METHOD: In 2002-2003 we conducted 12 focus groups with pharmacists, general practitioners and school physicians. A skilled moderator accompanied by an observer conducted the focus groups using a semi-structured screenplay. RESULTS: All these health care providers agree with the free access to emergency contraception (EC), but experience considerable frustration with regard to the practical aspects and the legal framework. General practitioners (GPs) claim to spend a lot of time on requests for EC and they are concerned about the quality of the counselling provided in pharmacies. Pharmacists are creative when giving counselling in the pharmacy, but there is, nevertheless, a problem with a lack of privacy. School physicians are frustrated that there is no legal possibility to respond to a request for EC when they feel they are ideally placed to advise adolescents. CONCLUSION: The over-the-counter sale of EC offers women better access, but many barriers still interfere with optimal care. Pharmacists experience a lack of skills to communicate with adolescents and a lack of privacy to give counselling. GPs have good intentions, but are confronted with a lack of willingness on the part of the patients and also financial barriers. School physicians want more possibilities to help adolescents. 相似文献
10.
Andreas Ritsch Christoph Ebenbichler Elisabeth Naschberger Wilfried Schgoer Ursula Stanzl Hermann Dietrich Peter C Heinrich Kazunori Saito Josef R Patsch 《Clinical chemistry and laboratory medicine》2004,42(3):247-255
Cholesteryl ester transfer protein (CETP) greatly affects the metabolism of all lipoprotein classes including low-density lipoprotein (LDL) and high-density lipoprotein (HDL), both known to constitute powerful risk factors for coronary artery disease (CAD). We now report the successful first cloning and characterization of single-chain antibody fragments specific for CETP. A recombinant phage display library was generated using spleen mRNA isolated from BALB/c mice that had been immunized with highly purified CETP. Screening of the library yielded two single-chain antibody fragments with high affinity for CETP, termed 1CL8 and 1CL10, displaying respective KD values of 4.36 x 10(-9) M and 4.64 x 10(-9) M as determined by affinity sensor technology. Amino acid sequence comparison indicated the complementarity-determining regions of the respective heavy chains to be responsible for CETP high affinity binding. Fragment 1CL8 was successfully employed in clinical chemical quantification systems that uncovered an association in humans between plasma CETP concentration and total body fat mass (r=0.50, p<0.002). Because of the demonstrated superb CETP capturing capacity, combined with high binding affinity to CETP, ready access and unlimited supply, 1CL8 and 1CL10 are expected to prove powerful tools for studies on the role of CETP in atherogenesis. 相似文献