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   5632篇
  免费   402篇
  国内免费   21篇
耳鼻咽喉   73篇
儿科学   115篇
妇产科学   45篇
基础医学   730篇
口腔科学   110篇
临床医学   602篇
内科学   1303篇
皮肤病学   136篇
神经病学   441篇
特种医学   365篇
外科学   832篇
综合类   27篇
一般理论   5篇
预防医学   354篇
眼科学   210篇
药学   353篇
中国医学   5篇
肿瘤学   349篇
  2023年   39篇
  2022年   72篇
  2021年   148篇
  2020年   86篇
  2019年   143篇
  2018年   177篇
  2017年   132篇
  2016年   161篇
  2015年   200篇
  2014年   225篇
  2013年   317篇
  2012年   431篇
  2011年   460篇
  2010年   261篇
  2009年   227篇
  2008年   335篇
  2007年   341篇
  2006年   356篇
  2005年   310篇
  2004年   267篇
  2003年   291篇
  2002年   238篇
  2001年   79篇
  2000年   75篇
  1999年   59篇
  1998年   49篇
  1997年   38篇
  1996年   26篇
  1995年   23篇
  1994年   22篇
  1993年   16篇
  1992年   37篇
  1991年   42篇
  1990年   32篇
  1989年   28篇
  1988年   34篇
  1987年   24篇
  1986年   16篇
  1985年   19篇
  1984年   21篇
  1983年   21篇
  1981年   11篇
  1979年   12篇
  1978年   9篇
  1977年   10篇
  1975年   9篇
  1974年   16篇
  1973年   10篇
  1972年   13篇
  1970年   9篇
排序方式: 共有6055条查询结果,搜索用时 15 毫秒
101.
Previous research stated a robust attentional bias to threat in adult anxiety. However, the number of studies analyzing attentional biases in clinically anxious children is limited and results are inconsistent. The present study aims to assess attentional biases in children with social anxiety disorder (n?=?37) and healthy control children (n?=?42) using a free-viewing eye-tracking paradigm. Children viewed different picture pairs consisting of social and non-social stimuli under two conditions (with/without a stressor to activate social threat perception). We found the direction of gaze regarding threatening stimuli to be context-dependent. Both groups showed a hypervigilance-avoidance pattern to angry faces when they were paired with houses. In face–face trials, angry faces were less often initially fixated than neutral or happy faces in both groups. However, schema activation differentially affected initial fixations in angry-neutral face pairs across groups. Children with social anxiety disorder more often initially directed their gaze to angry faces than did healthy control children, indicating a lack of inhibiting threat representations rather than a hypervigilance to threat.  相似文献   
102.
The present study aimed to elucidate the profile of coping in patients with obsessive–compulsive disorder (OCD) in order to discern whether the disorder is characterized by an excess of maladaptive coping skills and/or a lack of adaptive coping skills. Sixty individuals with OCD were compared with 110 individuals with depression and 1050 nonclinical controls on the Maladaptive and Adaptive Coping Styles Questionnaire (MAX). Psychopathology was assessed with the Obsessive–Compulsive Inventory-Revised (OCI-R), the Yale-Brown Obsessive–Compulsive Scale (Y-BOCS), and the Patient Health Questionnaire-9 for depression (PHQ-9). Individuals with OCD and depression displayed more maladaptive coping and avoidance as well as less adaptive coping than nonclinical controls. Importantly, adaptive coping was significantly lower in individuals with OCD than in those with depression at a medium effect size, whereas the clinical groups were indistinguishable on maladaptive coping and avoidance. Lack of adaptive coping was strongly correlated with resistance to symptoms and poor insight in OCD (Y-BOCS), even after controlling for depression. Lack of adaptive coping skills may represent a specific pathogenetic factor in OCD. Longitudinal studies need to clarify whether strengthening adaptive skills during childhood and adolescence may help to prevent the progression from subclinical to manifest OCD.  相似文献   
103.

Purpose

The association between severity of illness and ability to return to work is unclear. Therefore, we investigated return to work and associations with measures of illness severity in ICU survivors.

Methods

We conducted this cohort study using Danish registry data for the period 2005–2014 on ICU patients who were discharged alive from hospital, had an ICU length of stay (LOS) of at least 72 h, were not treated with dialysis before hospital admission and were working prior to admission. We assessed (1) the cumulative incidence (chance) of return to work (2005–2017) and receipt of social benefits after discharge from a hospital stay with ICU admission and (2) the association between organ support therapies (renal replacement therapy, cardiovascular support and mechanical ventilation), and during 2011–2014 SAPS II and ICU LOS, and return to work, using multivariable Cox regression.

Results

Among 5762 ICU survivors, 68% returned to work within 2 years after hospital discharge. Disability and sickness benefits constituted 89% of social benefits among patients not returning to work and 59% among patients withdrawing from work following an initial return to work. Mechanical ventilation (HR 0.70, 95% CI [0.65–0.77]), but not RRT (HR 0.85, 95% CI [0.71–1.02]), cardiovascular support (HR 0.93, 95% CI [0.82–1.07]) and increasing SAPS II, was associated with decreased chance of return to work. Increasing ICU LOS was also associated with a decreased chance of return to work.

Conclusions

The majority of a nationwide cohort of ICU survivors returned to work. Sick leave and receipt of disability pension were common following ICU admission. Mechanical ventilation and longer ICU LOS were associated with reduced chances of return to work.
  相似文献   
104.
105.
106.
107.
108.
109.
CardioVascular and Interventional Radiology - The study aimed to evaluate a new robotic assistance system (RAS) for needle placement in combination with a multi-axis C-arm angiography system for...  相似文献   
110.
Large clonal expansions of peripheral CD8+ T cells carrying receptors for single epitopes of CMV and EBV are common in the elderly and may be associated with an immune risk phenotype predicting mortality. Here we show that the frequency of CD8+ T cells expressing the inhibitory killer cell lectin-like receptor G1 (KLRG1), a marker of cells unable to undergo further clonal expansion, was markedly elevated in CD8+ T cells from old donors. Moreover, tetramer staining revealed that the elevated frequency of CMV-specific CD8+ T cells in the elderly was due to an accumulation of cells bearing this dominant negative receptor. The fraction of CMV-specific T cells able to secrete interferon-gamma after specific antigenic stimulation was significantly lower in the elderly than in the young, although the total number of functional cells was comparable. Therefore, the majority of the clonally expanded virus-specific CD8+ cells in the elderly was dysfunctional. Thus, T cell responses are altered in the aged by an accumulation of replicatively senescent dysfunctional T cells carrying receptors for persistent herpes viruses. The presence of clonal expansions of such virus-specific cells may shrink the available repertoire for other antigens and contribute to the increased incidence of infectious disease in the elderly.  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