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   3066篇
  免费   160篇
  国内免费   27篇
耳鼻咽喉   57篇
儿科学   36篇
妇产科学   92篇
基础医学   441篇
口腔科学   78篇
临床医学   384篇
内科学   437篇
皮肤病学   68篇
神经病学   252篇
特种医学   116篇
外国民族医学   1篇
外科学   506篇
综合类   13篇
预防医学   222篇
眼科学   100篇
药学   170篇
中国医学   2篇
肿瘤学   278篇
  2023年   24篇
  2022年   25篇
  2021年   48篇
  2020年   34篇
  2019年   40篇
  2018年   52篇
  2017年   41篇
  2016年   51篇
  2015年   72篇
  2014年   73篇
  2013年   126篇
  2012年   164篇
  2011年   161篇
  2010年   102篇
  2009年   105篇
  2008年   187篇
  2007年   154篇
  2006年   198篇
  2005年   144篇
  2004年   139篇
  2003年   130篇
  2002年   134篇
  2001年   55篇
  2000年   79篇
  1999年   67篇
  1998年   53篇
  1997年   35篇
  1995年   19篇
  1994年   23篇
  1992年   24篇
  1991年   29篇
  1990年   31篇
  1989年   27篇
  1988年   38篇
  1987年   26篇
  1986年   24篇
  1985年   34篇
  1984年   30篇
  1983年   30篇
  1982年   26篇
  1981年   22篇
  1980年   28篇
  1979年   34篇
  1978年   26篇
  1977年   25篇
  1976年   18篇
  1975年   23篇
  1974年   20篇
  1973年   31篇
  1971年   19篇
排序方式: 共有3253条查询结果,搜索用时 15 毫秒
201.
202.
203.
PURPOSE: The risk stratification criteria of the American Association of Cardiovascular and Pulmonary Rehabilitation include guidelines to be used in stratifying cardiac rehabilitation (CR) patients for risk of disease progression (long term) and clinical events (short term). Noncardiac comorbidities are not included as indicators in these criteria. This study was designed to ascertain the prevalence of noncardiac comorbidities among CR patients, and to assess their relation to the current risk stratification algorithm for clinical events. METHODS: Patients were stratified into high-, intermediate-, and low-risk groups according to the American Association of Cardiovascular and Pulmonary Rehabilitation risk stratification criteria for clinical events (ARSE) at program entry. Within each risk group, age, gender, race, and noncardiac comorbidities were ascertained. Comorbidities were summarized in a comorbidity index (CMI). The relation between clinical events and risk status by ARSE and CMI was evaluated by logistic regression. RESULTS: Among 490 patients (age, 60 +/- 12 years; 35% women; 30% nonwhite) enrolled in CR with ischemic heart disease, the number of comorbidities ranged from 0 to 7 (median, 2; 75th percentile, 3). The patients categorized in the three ARSE groups differed significantly in age and comorbidities. Although ARSE tended to identify patients with a greater comorbidity burden, 38% of the patients with a comorbidity index exceeding the 75th percentile were not classified in the highest ARSE group. Clinical events increased across ARSE and CMI risk strata. Both ARSE and CMI were independent predictors of events in an age-, gender-, and race-adjusted logistic regression analysis (ARSE odds ratio [OR], 1.56; 95% confidence interval [CI], 1.14-2.12; CMI OR, 1.23, 95% CI, 1.03a-1.47). Events were predicted best when both classifications were combined. Exploratory gender-specific analyses suggested that ARSE performed better among men than among women, whereas CMI was a more important predictor among women. CONCLUSIONS: To appreciate more fully the overall complexity of disease among CR patients, ARSE should be supplemented not only with the inclusion of cardiac risk factors, as suggested in the current guidelines, but also with an assessment of noncardiac comorbidities.  相似文献   
204.
The morphosyntactic decomposition of German compound words and a proposed function of linking elements were examined during auditory processing using event-related brain potentials. In Experiment 1, the syntactic gender agreement was manipulated between a determiner and the initial compound constituent (the 'nonhead' constituent), and between a determiner and the last constituent ('head'). Although only the head is (morpho)syntactically relevant in German, both constituents elicited a left-anterior negativity if its gender was incongruent. This strongly suggests that compounds are morphosyntactically decomposed. Experiment 2 tested the function of those linking elements which are homophonous to plural morphemes. It has been previously suggested that these indicate the number of nonhead constituents. The number agreement was manipulated for both constituents analogous to Experiment 1. Number-incongruent heads, but not nonhead constituents, elicited an N400 and a subsequent broad negativity, suggesting that linking elements are not processed as plural morphemes. Experiment 3 showed that prosodic cues (duration and fundamental frequency) are employed to differentiate between compounds and single nouns and, thereby, between linking elements and plural morphemes. Number-incongruent words elicited a broad negativity if they were produced with a single noun prosody; the same words elicited no event-related potential effect if produced with a compound prosody. A dual-route model can account for the influence of prosody on morphosyntactic processing.  相似文献   
205.
Therapy outcome is analysed according to the main diagnoses in a 5 years' sample of psychodynamic inpatient psychotherapy (n=461) and controlled in a 6-9 months follow-up (n=312). Therapy effects, as measured in a pre-post comparison of the patients' self-rating, are generally good and especially noticeable for affective and anxiety disorders, whereas the effects for somatoform disorders are relatively low. The opposite tendencies are seen in follow-up, i.e. relapses in anxiety and affective disorders, and further improvement in somatoform disorders. A surprisingly positive outcome is shown for personality disorders and especially for severe personality disorders (e.g. Borderline). Regardless of the diagnoses, 80% of the patients show a high degree of satisfaction with their treatment and its outcome.  相似文献   
206.
207.
Lipopolysaccharide binding protein (LBP) has a well-established role in LPS-induced immune responses. Here, we report that LBP also plays an essential role in the innate immune response to Gram-positive pneumococci, specifically to their major inflammatory component, pneumococcal cell wall (PCW). LBP was present in the CSF of patients with meningitis, and LBP-deficient mice failed to develop meningeal inflammation. LBP enhanced PCW-induced cell signaling and TNF-alpha release. LBP bound specifically to PCW multimers, indicating novel lipid-independent binding capability for LBP. We propose the iterative anionic groups along the glycan backbone of the cell wall are a crucial structure for recognition by LBP. Such a function for LBP expands its role to Gram-positive infections.  相似文献   
208.
Chronic pelvic pain affects upward of 15% of women and is a frustrating condition for both patients and physicians. Chronic pelvic pain is not a disease, but a syndrome that results from a complex interaction between neurologic, musculoskeletal, and endocrine systems that is further influenced by behavioral and psychologic factors. Traditional approaches to this disorder have been surgical, although long-term success rates have been disappointing. Placebo response to surgery is common, and many conditions that contribute to the pain cannot be identified or treated with a surgical approach. Many patients will require a combination of both pharmacologic and nonpharmacologic treatments in addition to various types of invasive procedures. It is now recognized that many disorders contribute to the chronic pelvic pain symptom complex; thus, an integrated multidisciplinary approach to diagnosis and treatment is essential to achieve the greatest success. TARGET AUDIENCE: Obstetricians & Gynecologists, Family Physicians. LEARNING OBJECTIVES: After completion of this article, the reader will be able to describe the pathophysiology of chronic pelvic pain, to outline the evaluation of a patient with chronic pelvic pain, and to explain the treatment options for patients with chronic pelvic pain.  相似文献   
209.
210.
OBJECTIVES: The purpose of this study was to assess ventricular mass, volume, and systolic function in patients late after Fontan operation by cardiac magnetic resonance imaging. BACKGROUND: An assessment of determinants for ventricular function in post-Fontan patients was intended. METHODS: Twenty-three unselected patients (9 female, 14 male) at a median age of 19.4 years (range, 7.8 to 31.3 years), at a median time of 10.5 years (range, 4.1 to 18 years) after Fontan operation were studied. A standard 1.5-T scanner was used, and analysis was performed using dedicated software. Ten healthy volunteers (median age 26.4, range 18 to 39.3 years) served as the control group. RESULTS: Median end-systolic mass index was 72.2 g/m(2) (range, 43 to 138 g/m(2)) and 86.6 g/m(2) (range, 52 to 123 g/m(2)) in the control group (p = NS). Median end-diastolic ventricular volume was 64 ml/m(2) (range, 32 to 117 ml/m(2)) compared with 67.7 ml/m(2) (range, 59 to 75 ml/m(2)) in the control group (p = NS). Median ejection fraction was 49.3% (range, 20% to 63%) compared with 64.8% (range, 57% to 79%) in normals (p = 0.00001). CONCLUSIONS: We conclude that long-term survivors of a Fontan operation have normal ventricular mass, normal volume, but reduced systolic ventricular function.  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