全文获取类型
收费全文 | 237779篇 |
免费 | 39657篇 |
国内免费 | 9687篇 |
专业分类
耳鼻咽喉 | 5777篇 |
儿科学 | 6146篇 |
妇产科学 | 3349篇 |
基础医学 | 13548篇 |
口腔科学 | 3050篇 |
临床医学 | 39326篇 |
内科学 | 59734篇 |
皮肤病学 | 8106篇 |
神经病学 | 19828篇 |
特种医学 | 9407篇 |
外国民族医学 | 56篇 |
外科学 | 48782篇 |
综合类 | 15580篇 |
现状与发展 | 94篇 |
一般理论 | 13篇 |
预防医学 | 12695篇 |
眼科学 | 6238篇 |
药学 | 10077篇 |
102篇 | |
中国医学 | 5829篇 |
肿瘤学 | 19386篇 |
出版年
2024年 | 984篇 |
2023年 | 6193篇 |
2022年 | 5442篇 |
2021年 | 8187篇 |
2020年 | 9845篇 |
2019年 | 5289篇 |
2018年 | 10672篇 |
2017年 | 10088篇 |
2016年 | 11103篇 |
2015年 | 12587篇 |
2014年 | 20593篇 |
2013年 | 19889篇 |
2012年 | 11857篇 |
2011年 | 12896篇 |
2010年 | 14785篇 |
2009年 | 17688篇 |
2008年 | 10227篇 |
2007年 | 8315篇 |
2006年 | 10987篇 |
2005年 | 8284篇 |
2004年 | 5651篇 |
2003年 | 4562篇 |
2002年 | 4209篇 |
2001年 | 5711篇 |
2000年 | 5044篇 |
1999年 | 5351篇 |
1998年 | 5069篇 |
1997年 | 4817篇 |
1996年 | 4449篇 |
1995年 | 4218篇 |
1994年 | 2774篇 |
1993年 | 2088篇 |
1992年 | 1967篇 |
1991年 | 1907篇 |
1990年 | 1514篇 |
1989年 | 1591篇 |
1988年 | 1356篇 |
1987年 | 1142篇 |
1986年 | 1108篇 |
1985年 | 888篇 |
1984年 | 624篇 |
1983年 | 567篇 |
1982年 | 552篇 |
1981年 | 434篇 |
1980年 | 382篇 |
1979年 | 327篇 |
1978年 | 328篇 |
1977年 | 396篇 |
1975年 | 277篇 |
1972年 | 302篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
31.
BMP-2 gene polymorphisms and osteoporosis: the Rotterdam Study. 总被引:7,自引:0,他引:7
Marco Medici Joyce Bj van Meurs Fernando Rivadeneira HongYan Zhao Pascal P Arp Albert Hofman Huibert Ap Pols André G Uitterlinden 《Journal of bone and mineral research》2006,21(6):845-854
After reported associations of variations in the BMP-2 gene with osteoporosis in small populations, we studied the association of the BMP-2 gene polymorphisms Ser37Ala and Arg190Ser with osteoporosis in 6353 men and women from the Rotterdam Study. We did not observe an association of these variants with BMD, bone loss, hip structural analysis parameters, and fracture risk. INTRODUCTION: Bone morphogenetic protein 2 (BMP-2) plays a role in osteoblast differentiation. BMP-2 gene variation has previously been associated with osteoporosis in various small populations, but current evidence remains inconclusive about the exact association with osteoporosis. Therefore, we studied the association of two polymorphisms located in the BMP-2 gene (Ser37Ala and Arg190Ser) and haplotypes defined by these polymorphisms with BMD, rates of bone loss, parameters of hip structural analysis (HSA), and fractures in the Rotterdam Study, a large prospective cohort study of diseases in the elderly. MATERIALS AND METHODS: Databases were searched for polymorphisms and haplotype blocks in the BMP-2 gene region. Allele frequencies for Ser37Ala and Arg190Ser were determined in 60 blacks and 110 Chinese from Coriell panels. Genotype data on Ser37Ala and Arg190Ser were available for 6353 individuals from the Rotterdam Study population. Haplotype alleles defined by Ser37Ala and Arg190Ser were inferred using PHASE software. Genotype and haplotype analyses for BMD (measured at the lumbar spine and femoral neck), bone loss per year (measured at the femoral neck), and HSA were performed using AN(C)OVA. Fractures were analyzed using a Cox proportional-hazards model and logistic regression. All outcomes were adjusted for age, height, and weight. RESULTS: Allele frequencies were 2.5% for Ala37 and 40.2% for Ser190, whereas haplotype allele frequencies were 57.28% (Ser37Arg190), 40.19% (Ser37Ser190), 2.50% (Ala37Arg190), and 0.02% (Ala37Ser190). For BMD, bone loss, HSA outcomes, and (incident) fractures, no differences could be seen between genotype and haplotype groups. Conclusions: In this large population-based cohort of Dutch whites, we conclude that the BMP-2 Ser37Ala and Arg190Ser polymorphisms or haplotypes thereof are not associated with parameters of osteoporosis. 相似文献
32.
Timothy C. Evans MD PhD ; Keren H. Wick PhD ; Douglas M. Brock PhD ; Douglas C. Schaad PhD ; Ruth Ballweg MPA PA-C 《The Journal of rural health》2006,22(3):212-219
CONTEXT: The physician assistant profession has been moving toward requiring master's degrees for new practitioners, but some argue this could change the face of the discipline. PURPOSE: To see if there is an association between physician assistants' academic degrees and practice in primary care, in rural areas, and with the medically underserved. METHODS: Surveys were sent to 880 graduates of the first 32 University of Washington physician assistant classes through 2000. Respondents noted their academic degree at program entry and the highest degree attained at any time up to the time of survey. Relationships between practice characteristics and academic degree levels were tested by unadjusted odds ratios and logistic regression after controlling for year of graduation and sex. RESULTS: Of the 478 respondents, 54% worked in primary care, about 30% practiced in nonmetropolitan communities, and 42% reported providing care for the medically underserved. Respondents with no degree (33% of total at entry, 24% at survey) were significantly more likely than degree holders to work in primary care and nonmetropolitan areas. Respondents with no degree at program entry were significantly more likely, and those with no degree at the time of the survey were marginally more likely, to self-report work with the medically underserved. CONCLUSION: Respondents with no academic degree are significantly more likely to demonstrate a commitment to primary, rural, and underserved health care. These findings may inform the national debate about the impact of required advanced degrees on the practice patterns of nonphysician providers. 相似文献
33.
34.
This review discusses treatment options for men with premature ejaculation (PE), a common sexual dysfunction characterized
by short ejaculatory latency, decreased sexual satisfaction, and distress. For a number of reasons, including embarrassment
and the belief that PE is a normal part of aging, that it has no effective treatment, or that it will resolve itself, few
men with PE seek treatment. Although several treatment options exist (eg, behavioral, cognitive, and sex therapy methods;
desensitizing drugs; off-label use of antidepressants, phosphodiesterase type 5 inhibitors, or à-blockers), the majority of
men with PE are not satisfied with their results. New pharmacologic drugs develped specifically for the treatment of PE are
undergoing evaluation in clinical trials. For example, recent clinical research studies have revealed on-demand administration
of one such drug, dapoxetine, which achieved significant improvements in ejaculatory latency, control over ejaculation, and
satisfaction with sexual intercourse. In addition, partners of men who received dapoxetine likewise reported improved satisfaction
with sexual intercourse. Future studies may reveal that integration of pharmacologic drugs with psychologic and/or behavioral
therapy techniques may be the optimal approach to the management of PE. PE is a treatable condition, and new drugs in development
may provide benefits over those available. 相似文献
35.
36.
37.
Vincent Chung Liang Liu Zhaoxiang Bian Zhongzhen Zhao Wai Leuk Fong Wan Fung Kum Jing Gao Min Li 《Movement disorders》2006,21(10):1709-1715
The objective of this study is to assess the efficacy and safety of herbal medicines (HMs), as a monotherapy or adjunct therapy, compared to placebo or conventional approaches in the treatment of idiopathic Parkinson's disease (PD). We conducted a systematic review of randomized controlled trials from both conventional and alternative medicine sources. Outcome measures were overall improvement, quality of life, reduction of levodopa dose, and adverse events. Nine studies were included, each testing a different HM. Six of the trials had limited internal validity due to major flaws in design, including the lack of proper randomization; insufficient blinding; unclear inclusive criteria in terms of diagnostic criteria, baseline staging, and duration of disease; lack of proper sample size calculation; and insufficient data analysis. Imbalances in gender and ethnicity among the patients in the included trials were observed. No major adverse events emerged, and no specific pattern was detected from the trials describing such data. In addition to major methodological defects, heterogeneity in (1) HM tested, (2) control treatment, and (3) outcome measure hindered in-depth data analysis and synthesis. Current evidence is insufficient to evaluate the efficacy and safety of various HMs. Further studies with improved trial design and reporting, with assessment on cost-effectiveness, quality of life, and qualitative data are warranted. 相似文献
38.
39.
40.
Prostatitis and male infertility are frequent disorders, and the role of prostatitis in male infertility has been under discussion for more than 30 years. Many researchers have shown relevant links between the two. Although a causal relationship has not been definitely demonstrated, increasing evidence shows that chronic prostatitis has a relevant negative impact on male fertility potential, at least in certain subgroups. In the following review, we focus on the present state of knowledge on the role of chronic prostatitis as an etiologic factor in male infertility. 相似文献