首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   252541篇
  免费   18616篇
  国内免费   1125篇
耳鼻咽喉   2858篇
儿科学   6576篇
妇产科学   4646篇
基础医学   33164篇
口腔科学   4617篇
临床医学   25565篇
内科学   53503篇
皮肤病学   3407篇
神经病学   24421篇
特种医学   8642篇
外国民族医学   11篇
外科学   38679篇
综合类   3482篇
一般理论   319篇
预防医学   21328篇
眼科学   6566篇
药学   17130篇
  4篇
中国医学   364篇
肿瘤学   17000篇
  2023年   1221篇
  2022年   945篇
  2021年   5338篇
  2020年   3289篇
  2019年   5351篇
  2018年   6012篇
  2017年   4521篇
  2016年   5005篇
  2015年   5900篇
  2014年   8691篇
  2013年   11899篇
  2012年   18152篇
  2011年   19065篇
  2010年   10669篇
  2009年   9531篇
  2008年   16772篇
  2007年   17617篇
  2006年   17484篇
  2005年   17456篇
  2004年   16364篇
  2003年   15190篇
  2002年   14176篇
  2001年   2278篇
  2000年   1735篇
  1999年   2437篇
  1998年   3122篇
  1997年   2589篇
  1996年   1823篇
  1995年   2075篇
  1994年   1733篇
  1993年   1553篇
  1992年   1299篇
  1991年   1234篇
  1990年   1075篇
  1989年   1035篇
  1988年   1005篇
  1987年   1002篇
  1986年   983篇
  1985年   1025篇
  1984年   1232篇
  1983年   1143篇
  1982年   1345篇
  1981年   1303篇
  1980年   1141篇
  1979年   716篇
  1978年   762篇
  1977年   646篇
  1976年   591篇
  1975年   481篇
  1974年   509篇
排序方式: 共有10000条查询结果,搜索用时 249 毫秒
101.
102.
Objectives: There is a paucity of reporting on surgical outcomes of isolated posterior cruciate ligament reconstruction (PCLR). We hypothesize that isolated PCL injuries failing nonoperative treatment achieve good outcomes and are able to return to sport following PCLR.

Methods: A retrospective analysis was performed to identify patients with isolated PCL injuries that underwent reconstruction between 2001 and 2014. Patients with multi-ligamentous injury or another concomitant knee pathology were excluded. Medical records were reviewed for demographic, clinical and operative data. Patients were contacted for administration of a telephone-based questionnaire which included the International Knee Documentation Committee (IKDC) Subjective Knee Evaluation form, Lysholm-Tegner scales, Marx activity scale (MAS), return to sport status, and patient satisfaction instruments.

Results: A total of 15 isolated PCL reconstructions in 14 patients with a mean age of 27.5 years (range 17–43) met the study inclusion criteria; mean follow up was 6.3 years (range 1.4–15.2). Pre-operatively, the primary complaint was knee instability in all patients; on physical examination, lack of a firm end point during posterior drawer testing was found in 93% (14/15) of the knees. In total, 12 of 15 knees underwent transtibial, single-bundle PCLR and three of 15 underwent tibial inlay, double bundle PCLR. Graft types included: quadriceps autograft (7/15), Achilles allograft (6/15), and hamstring autograft (2/15). There were no graft failures in our patient cohort. At most recent follow up the mean scores respectively on the IKDC form, Lysholm-Tegner scales and MAS were (standard deviation): 77.3 (16.5), 83.1 (17.9), 6.13 (2.6), and 7.1 (6.0). All fourteen patients were athletes prior to their injury and 79% (11/14) returned to sport and overall patient satisfaction was 9.2/10.

Conclusions: Isolated PCLR provides good outcomes at mean medium-term follow up with restoration of function, high rate of return to sport and overall patient satisfaction.  相似文献   

103.
The fat mass and obesity-associated gene (FTO) rs9939609 A-allele is linked to obesity and dyslipidemia, yet the independent influence of this polymorphism on blood lipids remains equivocal. We examined the influence of the FTO rs9939609 polymorphism on fasting and postprandial blood lipids in individuals homozygous for the risk A-allele or T-allele with similar anthropometric and demographic characteristics. 12 AA and 12 TT males consumed a standardized meal after fasting overnight. Blood samples were collected at baseline (−1.5 h), before the meal (0 h), and for five hours postprandially to measure lipid, glucose, and insulin concentrations. Time-averaged total area under the curve (TAUC) values (0–5 h) were calculated and compared between genotypes. Fasting triacylglycerol (TG), high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, total cholesterol, non-esterified fatty acid (NEFA), glucose, and insulin concentrations were similar between groups (p ≥ 0.293). TAUC for TG was similar in AAs and TTs (95% confidence interval (CI) −0.52 to 0.31 mmol/L/h; p = 0.606). Likewise, TAUC values were similar for NEFA (95% CI −0.04 to 0.03 mmol/L/h; p = 0.734), glucose (95% CI −0.41 to 0.44 mmol/L/h; p = 0.951), and insulin (95% CI −6.87 to 2.83 pmol/L/h; p = 0.395). Blood lipids are not influenced by the FTO rs9939609 polymorphism, suggesting the FTO-dyslipidemia link is mediated by adiposity and weight management is important in preventing FTO-related lipid variations.  相似文献   
104.
Street-connected youth in Kenya are a population potentially at risk of HIV transmission, yet little is known about their perceptions and experiences of sexually transmitted infections (STIs), despite their living in an HIV endemic region. We sought to elucidate the language and sociocultural factors rooted in street life that impact on street-connected young people’s knowledge of and perceptions about the prevention and transmission of STIs, and their diagnosis and treatment, using qualitative methods in western Kenya. We conducted a total of 25 in-depth interviews and 5 focus-group discussions with 65 participants aged 11–24 years in Eldoret, Kenya. Thematic analysis was conducted and data were coded according to themes and patterns emergent until saturation was reached. In general, street-connected young people knew of STIs and some of the common symptoms associated with these infections. However, there were many misconceptions regarding transmission and prevention. Gender inequities were prominent, as the majority of men described women as individuals who spread STIs due to unhygienic practices, urination and multiple partners. Due to misconceptions, gender inequity and lack of access to youth-friendly healthcare there is an urgent need for community-based organisations and healthcare facilities to introduce or augment their adolescent sexual and reproductive health programmes for vulnerable young people.  相似文献   
105.
106.

Objectives

This document offers guidance to clinicians and facilities on the use of telemedicine to deliver medically necessary evaluation and management of change of condition for nursing home residents.

Settings and participants

Members of the telemedicine workgroup of AMDA—The Society for Post-Acute Long-Term Medicine-developed this guideline through both telephonic and face-to-face meetings between April 2017 and September 2018. The guideline is based on the currently available research, experience, and expertise of the workgroup's members, including a summary of a recently completed systematic mixed studies literature review to determine evidence for telemedicine to reduce emergency department visits or hospitalizations of nursing home residents.

Results

Research and experience to date support the use of telemedicine as a tool in change of condition assessment and management as a means of reducing unnecessary emergency department visits and hospitalization. Telemedicine-delivered care should be integrated into the primary care of the resident and delivered by providers with competency in post-acute long-term care. The development and sustainability of telemedicine programs is heavily dependent on financial implications. Quality measures should be defined for telemedicine programs in nursing homes.

Conclusions/Implications

Telemedicine programs in nursing homes can contribute to the delivery of timely, high quality medical care, which reduces unnecessary hospitalization. Reimbursement for telemedicine-driven care should be based upon medical necessity of visits to care and the maintenance of quality standards. More studies are needed to understand which telemedicine tools and processes are most effective in improving outcomes for nursing home residents.  相似文献   
107.
108.
The impact of primary hand osteoarthritis (HOA) on bone mass, microstructure, and biomechanics in the affected skeletal regions is largely unknown. HOA patients and healthy controls (HCs) underwent high-resolution peripheral quantitative computed tomography (HR-pQCT). We measured total, trabecular, and cortical volumetric bone mineral densities (vBMDs), microstructural attributes, and performed micro–finite element analysis for bone strength. Failure load and scaled multivariate outcome matrices from distal radius and second metacarpal (MCP2) head measurements were analyzed using multiple linear regression adjusting for age, sex, and functional status and reported as adjusted Z-score differences for total and direct effects. A total of 105 subjects were included (76 HC: 46 women, 30 men; 29 HOA: 23 women, six men). After adjustment, HOA was associated with significant changes in the multivariate outcome matrix from the MCP2 head (p < .001) (explained by an increase in cortical vBMD (Δz = 1.07, p = .02) and reduction in the trabecular vBMD (Δz = −0.07, p = .09). Distal radius analysis did not show an overall effect of HOA; however, there was a gender-study group interaction (p = .044) explained by reduced trabecular vBMD in males (Δz = −1.23, p = .02). HOA was associated with lower failure load (−514 N; 95%CI, −1018 to −9; p = 0.05) apparent in males after adjustment for functional status. HOA is associated with reduced trabecular and increased cortical vBMD in the MCP2 head and a reduction in radial trabecular vBMD and bone strength in males. Further investigations of gender-specific changes of bone architecture in HOA are warranted. © 2020 The Authors. Journal of Bone and Mineral Research published by American Society for Bone and Mineral Research.  相似文献   
109.
Triple-negative breast cancer (TNBC) is defined as a type of breast cancer with lack of expression of estrogen receptor, progesterone receptor and human epidermal growth factor 2 protein. In comparison to other types of breast cancer, TNBC characterizes for its aggressive behavior, more prone to early recurrence and a disease with poor response to molecular target therapy. Although TNBC is identified in only 25%-30% of American breast cancer cases annually, these tumors continue to be a therapeutic challenge for clinicians for several reasons: Tumor heterogeneity, limited and toxic systemic therapy options, and often resistance to current standard therapy, characterized by progressive disease on treatment, residual tumor after cytotoxic chemotherapy, and early recurrence after complete surgical excision. Cell-surface targeted therapies have been successful for breast cancer in general, however there are currently no approved cell-surface targeted therapies specifically indicated for TNBC. Recently, several cell-surface targets have been identified as candidates for treatment of TNBC and associated targeted therapies are in development. The purpose of this work is to review the current clinical challenges posed by TNBC, the therapeutic approaches currently in use, and provide an overview of developing cell surface targeting approaches to improve outcomes for treatment resistant TNBC.  相似文献   
110.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号