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   2672篇
  免费   197篇
  国内免费   15篇
耳鼻咽喉   4篇
儿科学   153篇
妇产科学   72篇
基础医学   297篇
口腔科学   59篇
临床医学   199篇
内科学   536篇
皮肤病学   54篇
神经病学   163篇
特种医学   320篇
外国民族医学   1篇
外科学   470篇
综合类   86篇
预防医学   234篇
眼科学   24篇
药学   72篇
中国医学   2篇
肿瘤学   138篇
  2023年   16篇
  2022年   28篇
  2021年   50篇
  2020年   39篇
  2019年   56篇
  2018年   70篇
  2017年   55篇
  2016年   52篇
  2015年   45篇
  2014年   55篇
  2013年   82篇
  2012年   120篇
  2011年   147篇
  2010年   91篇
  2009年   91篇
  2008年   141篇
  2007年   117篇
  2006年   114篇
  2005年   107篇
  2004年   88篇
  2003年   114篇
  2002年   88篇
  2001年   88篇
  2000年   81篇
  1999年   66篇
  1998年   44篇
  1997年   61篇
  1996年   51篇
  1995年   37篇
  1994年   33篇
  1993年   26篇
  1992年   53篇
  1991年   59篇
  1990年   39篇
  1989年   42篇
  1988年   51篇
  1987年   50篇
  1986年   50篇
  1985年   30篇
  1984年   23篇
  1983年   21篇
  1982年   27篇
  1981年   26篇
  1980年   28篇
  1979年   23篇
  1978年   13篇
  1977年   17篇
  1976年   12篇
  1972年   9篇
  1967年   10篇
排序方式: 共有2884条查询结果,搜索用时 15 毫秒
101.
102.

Introduction and aim

Operative fixation of distal radius fractures using fixed-angle devices has become increasingly common. Although good to excellent results have been reported in acute fractures, little is currently known regarding the fixation of healing displaced distal radius fractures that were presented late. The aim of this study was to evaluate the results of internal fixation of distal radius fractures presented late (>21 days) as compared with an acute-care control group.

Methods

Forty patients operated on for displaced distal radius fractures, presenting more than 21 days after injury (delayed treatment (DT) group), were compared with 75 age-matched controls with acute fracture repair (≤21 days). The same surgical approach was used in both groups, together with dorsal soft-tissue and brachioradialis release. No osteotomy was required. Direct and indirect reduction aids were used. A fixed-angle device (DVR; Biomet Inc., Warsaw, IN, USA) was used in both groups. Mean follow-up was 3.4 years. Quick DASH (Disabilities of the Arm, Shoulder and Hand) and Short Form 12 scores were used to evaluate outcome, as well as radiographic analysis for Arbeitsgemeinschaft für Osteosynthesefragen(AO)/Orthopaedic Trauma Association(OTA) classification, volar tilt, radial inclination and radial length.

Results

Average age was 53 years in both groups and male to female (M/F) ratio was similar in the study groups. Mean time to surgery was 30 days in the DT group and 8 days in the control group. There were significantly more type C (91.5% vs. 67.5%) fractures in the control group. The average quick DASH score was 27.1 in the DT group as compared with 6.3 in the control group (p < 0.03); however, when controlling for two outlier cases with complications (hardware irritation and a sensory neuropathy) there was no significant difference. Volar tilt, radial inclination and length were similar in both groups and were within normal anatomical values.

Conclusions

Delayed primary operative fixation of displaced unstable distal radial fractures is a viable option for cases that were presented late, with predictable, favourable results. Neither extensile approaches nor formal osteotomies are required.  相似文献   
103.
104.
105.
Colon  Maria  El Khoury  Lara 《Clinical rheumatology》2020,39(7):2223-2226
Clinical Rheumatology - The occurrence of orbital compartment syndrome is a rare and unusual complication of systemic lupus erythematosus (SLE). Patients will present with symptoms of ocular pain...  相似文献   
106.
107.
Disrupted maternal interaction in early infancy is associated with maladaptive child outcomes. Thus, identifying early risk factors for disrupted interaction is an important challenge. Research suggests that maternal depressive symptoms and maternal cortisol dysregulation are associated with disrupted maternal interaction, but both factors have rarely been considered together as independent or interactive predictors of disrupted interaction. In a sample of 51 women, hair cortisol concentrations (HCC) and depressive symptoms were assessed during pregnancy, and depressive symptoms were assessed again at 4-month postpartum. Maternal disrupted interaction was assessed during the Still-Face Paradigm at 4 months. Results indicated that HCC and depressive symptoms interacted to predict both maternal withdrawing and inappropriate/intrusive interaction. Withdrawing interaction was associated with high levels of HCC in pregnancy in the context of high depressive symptoms at 4 months; inappropriate/intrusive interaction was associated with high levels of HCC in the context of low depressive symptoms. Thus, high HCC potentiated both forms of disrupted interaction. Results raised questions about the meaning of very low reported depressive symptoms, and underscored the importance of chronic stress physiology and maternal depressed mood as risk factors for distinct forms of maternal disrupted interaction, both of which are deleterious for infant development.  相似文献   
108.
Biomedicine is undergoing a revolution driven by high throughput and connective computing that is transforming medical research and practice. Using oncology as an example, the speed and capacity of genomic sequencing technologies is advancing the utility of individual genetic profiles for anticipating risk and targeting therapeutics. The goal is to enable an era of “P4” medicine that will become increasingly more predictive, personalized, preemptive, and participative over time. This vision hinges on leveraging potentially innovative and disruptive technologies in medicine to accelerate discovery and to reorient clinical practice for patient-centered care. Based on a panel discussion at the Medicine 2.0 conference in Boston with representatives from the National Cancer Institute, Moffitt Cancer Center, and Stanford University School of Medicine, this paper explores how emerging sociotechnical frameworks, informatics platforms, and health-related policy can be used to encourage data liquidity and innovation. This builds on the Institute of Medicine’s vision for a “rapid learning health care system” to enable an open source, population-based approach to cancer prevention and control.  相似文献   
109.
BACKGROUND Retained common bile duct(CBD) stone after an acute episode of biliary pancreatitis is of paramount importance since stone extraction is mandatory.AIM To generate a simple non-invasive score to predict the presence of CBD stone in patients with biliary pancreatitis.METHODS We performed a retrospective study including patients with a diagnosis of biliary pancreatitis. One hundred and fifty-four patients were included. Thirty-three patients(21.5%) were diagnosed with CBD stone by endoscopic ultrasound(US).RESULTS In univariate analysis, age(OR: 1.048, P = 0.0004), aspartate transaminase(OR:1.002, P = 0.0015), alkaline phosphatase(OR: 1.005, P = 0.0005), gamma-glutamyl transferase(OR: 1.003, P = 0.0002) and CBD width by US(OR: 1.187, P = 0.0445)were associated with CBD stone. In multivariate analysis, three parameters were identified to predict CBD stone;age(OR: 1.062, P = 0.0005), gamma-glutamyl transferase level(OR: 1.003, P = 0.0003) and dilated CBD(OR: 3.685, P = 0.027),with area under the curve of 0.8433. We developed a diagnostic score that included the three significant parameters on multivariate analysis, with assignment of weights for each variable according to the co-efficient estimate. A score that ranges from 51.28 to 73.7 has a very high specificity(90%-100%) for CBD stones, while a low score that ranges from 9.16 to 41.04 has a high sensitivity(82%-100%). By performing internal validation, the negative predictive value of the low score group was 93%.CONCLUSION We recommend incorporating this score as an aid for stratifying patients with acute biliary pancreatitis into low or high probability for the presence of CBD stone.  相似文献   
110.
The role of periconceptional folic acid in the prevention of neural tube defects (NTDs) is well established. However, it is not clear whether a protective effect exists for the subset of nonsyndromic NTD with other “unrelated” major structural birth defects (NTD-multiples). This question is important to investigate because of shared pathogenetic mechanisms between NTD and other types of birth defects, and because of the epidemiologic differences that have been shown between NTD-multiples and NTD-singles. We analyzed data from two population-based case-control studies of NTDs, Atlanta 1968–1980, and California 1989–1991, to assess whether periconceptional multivitamin use reduces the risk of NTD-multiples. Maternal vitamin histories were assessed for 47 and 65 NTD-multiples cases and 3,029 and 539 control babies in Atlanta, and California, respectively. There was a substantial risk reduction associated with periconceptional multivitamin use (−3 to +3 months) for NTD-multiples (pooled odds ratio = 0.36, 95% C.I. 0.18–0.72) that persisted after adjustment for maternal race/ethnicity and education. Also, no specific types of NTDs or NTDs with specific defects explained the risk reduction with vitamin use. These data suggest that multivitamins reduce the risk of nonsyndromic NTD cases associated with other major birth defects. The implication of this finding for the role of vitamins in the prevention of non-NTD birth defects should be further explored. © 1996 Wiley-Liss, Inc.  相似文献   
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