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   6305篇
  免费   541篇
  国内免费   12篇
耳鼻咽喉   49篇
儿科学   132篇
妇产科学   104篇
基础医学   817篇
口腔科学   103篇
临床医学   847篇
内科学   1265篇
皮肤病学   94篇
神经病学   543篇
特种医学   204篇
外科学   997篇
综合类   56篇
一般理论   3篇
预防医学   588篇
眼科学   90篇
药学   456篇
中国医学   7篇
肿瘤学   503篇
  2023年   57篇
  2022年   90篇
  2021年   321篇
  2020年   188篇
  2019年   252篇
  2018年   275篇
  2017年   204篇
  2016年   173篇
  2015年   262篇
  2014年   264篇
  2013年   394篇
  2012年   482篇
  2011年   512篇
  2010年   255篇
  2009年   177篇
  2008年   331篇
  2007年   310篇
  2006年   335篇
  2005年   247篇
  2004年   244篇
  2003年   208篇
  2002年   174篇
  2001年   101篇
  2000年   89篇
  1999年   77篇
  1998年   43篇
  1997年   37篇
  1996年   35篇
  1995年   37篇
  1994年   20篇
  1993年   27篇
  1992年   52篇
  1991年   53篇
  1990年   49篇
  1989年   51篇
  1988年   35篇
  1987年   34篇
  1986年   31篇
  1985年   42篇
  1984年   34篇
  1983年   21篇
  1981年   14篇
  1979年   19篇
  1975年   19篇
  1974年   15篇
  1973年   16篇
  1971年   15篇
  1970年   16篇
  1968年   14篇
  1966年   14篇
排序方式: 共有6858条查询结果,搜索用时 15 毫秒
1.
2.
ObjectivesCocaine is the second most frequently used illicit drug worldwide (after cannabis), and cocaine use disorder (CUD)-related deaths increased globally by 80% from 1990 to 2013. There is yet to be a regulatory-approved treatment. Emerging preclinical evidence indicates that deep brain stimulation (DBS) of the nucleus accumbens may be a therapeutic option. Prior to expanding the costly investigation of DBS for treatment of CUD, it is important to ensure societal cost-effectiveness.AimsWe conducted a threshold and cost-effectiveness analysis to determine the success rate at which DBS would be equivalent to contingency management (CM), recently identified as the most efficacious therapy for treatments of CUDs.Materials and MethodsQuality of life, efficacy, and safety parameters for CM were obtained from previous literature. Costs were calculated from a societal perspective. Our model predicted the utility benefit based on quality-adjusted life-years (QALYs) and incremental-cost-effectiveness ratio resulting from two treatments on a one-, two-, and five-year timeline.ResultsOn a one-year timeline, DBS would need to impart a success rate (ie, cocaine free) of 70% for it to yield the same utility benefit (0.492 QALYs per year) as CM. At no success rate would DBS be more cost-effective (incremental-cost-effectiveness ratio <$50,000) than CM during the first year. Nevertheless, as DBS costs are front loaded, DBS would need to achieve success rates of 74% and 51% for its cost-effectiveness to exceed that of CM over a two- and five-year period, respectively.ConclusionsWe find DBS would not be cost-effective in the short term (one year) but may be cost-effective in longer timelines. Since DBS holds promise to potentially be a cost-effective treatment for CUDs, future randomized controlled trials should be performed to assess its efficacy.  相似文献   
3.
4.
Choledochal cyst is an unusual but serious condition which most commonly affects Oriental people. Recent experience of three patients with this condition in whom diagnosis was made by ultrasound examination is reported. Cholangiography (ERCP or PTC) was performed in two of the cases to define the anatomy. All three cases were successfully managed by cyst excision and biliary reconstruction by Roux-en-Y hepaticojejunostomy. The rationale for and importance of cyst excision are discussed.  相似文献   
5.
6.
This study examined the structure and symptom correlates of perfectionism in a sample of 6th-grade, urban, African American children using the Child and Adolescent Perfectionism Scale (CAPS; Flett, Hewitt, Boucher, Davidson, & Munro, 2000). Confirmatory factor analysis showed inadequate fit of the original subscales. Exploratory factor analysis suggested 3 dimensions of perfectionism: A Socially Prescribed and a Self-Oriented-Critical factor were described as maladaptive, whereas a Self-Oriented-Striving factor was proposed as adaptive. Cross-sectional correlations among the perfectionism dimensions and symptoms of psychopathology fit well with the adaptive versus maladaptive model. In addition, Socially Prescribed Perfectionism showed a robust predictive relation to 7th-grade internalizing symptoms, especially depression, in boys. Results are discussed in the context of the cultural and socioeconomic characteristics of this African American sample and suggestions for future research are provided.  相似文献   
7.
Purpose To perform an audit of paediatric surgical patients in a provincial general surgical unit. Methodology Data was prospectively recorded using a standardized proforma on all children aged up to 15 yrs, seen between 11th December 2005 and 11th December 2006. Results There were 209 admissions (194 children), median age 8 yrs (6 wks–15 yrs) with 153 (73%) acutes. 37 children (18%) were under 2 yrs. Male : female ratio was 3 : 2. Procedures (n = 119) were appendicectomy (35), inguinal herniotomy (30), skin procedures (29), endoscopy (10), testicular (10) and others (5). The commonest acute and elective operations were appendicectomy and inguinal herniotomy respectively. 51% of operations were acute. There were 10 tertiary hospital transfers (5%) for burns (4), pyloric stenosis (3), intussusseption (1), neonatal inguinal hernia (1) and pyoderma gangrenosum (1). Median age of transfers was 11 months (6 wks–14 yrs). Complications were wound infection (1), post‐operative ileus (2) and infarcted ovary (1). Conclusion There are increasing moves towards centralization in paediatric surgery. 1 With only 4 paediatric tertiary centres in NZ, many general surgeons routinely perform paediatric surgery. A large number of children presented to our surgical department. Around half of these children required surgery and half of operations were acute. There is still a significant need for general paediatric surgery in the provinces and hence close collaboration with specialist paediatric surgeons.  相似文献   
8.
Fracture risk in monoclonal gammopathy of undetermined significance.   总被引:3,自引:0,他引:3  
To assess fractures in monoclonal gammopathy of undetermined significance (MGUS), the precursor of multiple myeloma, we followed 488 Olmsted County, MN, residents with MGUS in a retrospective cohort study. There was a 2.7-fold increase in the risk of axial fractures but no increase in limb fractures. The pathophysiologic basis for the increased axial fractures should be determined. INTRODUCTION: Multiple myeloma is often preceded by monoclonal gammopathy of undetermined significance (MGUS). Fractures are common in myeloma as a result of lytic bone lesions, generalized bone loss, and elevated bone turnover from excessive cytokine production. Whether fractures are also increased in MGUS is unknown. MATERIALS AND METHODS: In a population-based retrospective cohort study, 488 Olmsted County, MN, residents with MGUS first diagnosed in 1960-1994 (52% men; mean age, 71.4 +/- 12.8 years) were followed for 3901 person-years; follow-up was censored at progression to myeloma. The relative risk of fractures was assessed by standardized incidence ratios (SIRs), and risk factors were evaluated in proportional hazards models. RESULTS AND CONCLUSIONS: Altogether, 200 patients experienced 385 fractures. Compared with expected rates in the community, statistically significant increases were seen for fractures at most axial sites, for example, vertebrae (SIR, 6.3; 95% CI, 5.2-7.5). There was a slight increase in hip (SIR, 1.6; 95% CI, 1.2-2.2) but not distal forearm fractures (SIR, 0.8; 95% CI, 0.4-1.5). The relative risk (SIR) of any axial fracture was 2.7 (95% CI, 2.3-3.1) compared with only 1.1 (95% CI, 0.9-1.4) for all limb fractures combined. In a multivariate analysis, the independent predictors of any subsequent fracture were age (hazard ratio [HR] per 10-year increase, 1.4; 95% CI, 1.2-1.6) and corticosteroid use (HR, 1.8; 95% CI, 1.2-2.6); greater weight at diagnosis (HR per 10 kg, 0.8; 95% CI, 0.8-0.9), and IgG monoclonal protein (HR, 0.7; 95% CI, 0.5-0.97) were protective. Baseline monoclonal protein level, a determinant of myeloma progression, did not predict fracture risk. Thus, the risk of axial, but not peripheral, fractures is increased among MGUS patients even before progression to myeloma. The pathophysiologic basis for this should be determined because elevated bone turnover, for example, might be treatable.  相似文献   
9.
10.
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