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   34141篇
  免费   2386篇
  国内免费   113篇
耳鼻咽喉   264篇
儿科学   1343篇
妇产科学   988篇
基础医学   4671篇
口腔科学   420篇
临床医学   4386篇
内科学   6517篇
皮肤病学   641篇
神经病学   3703篇
特种医学   773篇
外科学   3339篇
综合类   362篇
一般理论   37篇
预防医学   3991篇
眼科学   566篇
药学   2070篇
中国医学   57篇
肿瘤学   2512篇
  2024年   39篇
  2023年   257篇
  2022年   469篇
  2021年   932篇
  2020年   584篇
  2019年   968篇
  2018年   1042篇
  2017年   727篇
  2016年   848篇
  2015年   889篇
  2014年   1244篇
  2013年   1828篇
  2012年   2710篇
  2011年   2760篇
  2010年   1538篇
  2009年   1279篇
  2008年   2235篇
  2007年   2419篇
  2006年   2347篇
  2005年   2214篇
  2004年   1977篇
  2003年   1837篇
  2002年   1742篇
  2001年   259篇
  2000年   203篇
  1999年   244篇
  1998年   335篇
  1997年   297篇
  1996年   233篇
  1995年   198篇
  1994年   164篇
  1993年   191篇
  1992年   134篇
  1991年   118篇
  1990年   89篇
  1989年   83篇
  1988年   103篇
  1987年   54篇
  1986年   60篇
  1985年   59篇
  1984年   70篇
  1983年   71篇
  1982年   61篇
  1981年   51篇
  1980年   69篇
  1979年   53篇
  1978年   45篇
  1977年   38篇
  1976年   29篇
  1973年   28篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
To enhance individual and family health during recovery from heart surgery, this study employed nursing interventions based on self-efficacy and family stress theory during the hospitalization period and for 3 months thereafter. The effectiveness of the interventions were assessed through a randomized trial in which 67 prospective bypass and valve surgery patients, aged 30-77 years, and their spouses, were allocated either the experimental interventions or usual care and followed for 6 months. At 3 months post-surgery, the only statistically significant differences between the experimentals and controls were on perceived self-efficacy for lifting and tolerating emotional distress. At 6 months no significant differences were found on individual or family measures. Analyses revealed that age, gender and preoperative cardiac status significantly affected individual recovery. The study is continuing with a larger sample in order to explicate the recovery process and to better determine whether a low intensity nursing intervention can effect changes in individual and family recovery.  相似文献   
32.
33.
BALB/c mice lack a corpus callosum in about 11% of the population.Two inbred substrains of BALB/c mice, epilepsy-prone (EP) andepilepsy-resistant (ER), have been examined to determine whetherthese substrains differ in regard to corpus callosum morphology.Further, this study addressed the issue of whether misroutedcortical axons form an aberrant pathway instead of the corpuscallosum. Initial studies that examined fresh brain tissue ofadult animals revealed normal corpora callosa in all ER micebut deficient or absent corpora callosa in all EP mice. Subsequently,Dil crystals were placed in the motor cortices of aldehyde-fixedbrains of 2-week-old animals to investigate cortical projectionsin both inbred substrains of mice. Fluorescent microscopy revealedthat all of the ER animals had normal corpora callosa, whereasall EP animals exhibited either reduced corpora callosa (partiallycallosal) or an absence (acallosal) of this structure. Bothacallosal and partially callosal EP mice displayed an extensive,aberrant projection to the basal forebrain as well as bilateralprojections to midline and intralaminar thalamic nuclei. Thefibers projecting to the basal forebrain arose from the cortex,coursed toward the midline before turning ventrally along themidline, and appeared to terminate in the medial septal nucleusand the nucleus of the diagonal band. ER animals lacked thisaberrant cortical projection to the basal forebrain. Electronmicroscopic results obtained from EP mice indicated that labeledaxons in this aberrant pathway formed axosomatic, axodendritic,and axospinous synapses with the neurons in the medial septal/diagonalband complex. The function of the aberrant projection to thebasal forebrain remains unknown but it may provide an abnormalexcitatory input to a region that provides cholinergic and GABAergicinput to the cerebral cortex and hippocampus. The additionalprojections to midline and contralateral intralaminar thalamicnuclei in EP mice may function to intensify the synchronizationof bilateral discharges.  相似文献   
34.
Catherine Jackson  Brian Lipworth 《Annals of allergy, asthma & immunology》2003,90(6):674; author reply 674-674; author reply 675
  相似文献   
35.
36.
Many techniques of magnetic resonance angiography depend on flow velocity. The broad normal range of venous flow velocities and preferential patterns of drainage, particularly in the transverse sinuses, may produce images that are diagnostically misleading. This reports such a case, with samples of various flow patterns in the transverse sinuses of other individuals, as demonstrated by one magnetic resonance angiographic technique (time-of-flight).  相似文献   
37.
PURPOSE: The purpose of this study was to identify significant predictors of 4 outcomes in patients with severe odontogenic infections: abscess formation, penicillin therapeutic failure (PTF), length of hospital stay (LOS), and need for reoperation. PATIENTS AND METHODS: We used a prospective case series study design and enrolled 37 consecutive patients admitted for severe odontogenic infection between March 1996 and June 1999. Treatment consisted of intravenous penicillin (PCN) or clindamycin in PCN-allergic patients, surgical incision and drainage, and extraction(s) as soon as possible. Study variables were categorized as demographic, preadmission, time-related, preoperative, anatomic, treatment, microbiologic, and complications. The primary outcome variables were abscess formation, PTF, LOS, and reoperation. Multivariate linear and logistic regression techniques were used to measure associations between study variables and the outcome variables. RESULTS: The sample consisted of 37 subjects (23 male, 14 female) with a mean age of 34.9 +/- 15.8 years. Multivariate analyses, controlling for confounding variables, indicated that culture of Peptostreptococci was a negative predictor of abscess formation. LOS was predicted by the number of infected spaces and duration of operation. There was no significant predictor of PTF or reoperation on multivariate analysis, although PCN-resistant organisms were isolated in all cases of PTF. CONCLUSION: Increased LOS in severe odontogenic infections is predicted by the anatomic extent and severity of the infection and the occurrence of complications such as PTF and the need for reoperation. PTF is significantly associated with later identification of PCN-resistant organisms. The role of Peptostreptococci in abscess formation warrants further investigation.  相似文献   
38.
The absence of critical dialogue regarding what constitutes family nursing prevents the further development of the specialty area of family nursing. In this essay, the author issues nine challenges faced by those who would contribute to the development of family nursing.  相似文献   
39.
The goal of this work was to investigate preference techniques to value potential health gains from treatments of Kaposi sarcoma (KS). The study was designed to take the form of face-to-face interviews with a sample of men with a history of HIV/AIDS ( n=15) or HIV/AIDS and KS ( n=17). The main outcome measure was quality of life (QoL) associated with various KS disease states expressed on a scale from 0 (death) to 1 (perfect health), obtained though time trade-off (TTO) and rating scale techniques. For cutaneous lesions only, the mean TTO preference score value was 0.27. In other words, the men were willing to trade a life expectancy of 5 years for a shorter period (1.4 years) in perfect health. More severe KS health states were rated lower (0.07-0.09). The mean rating scale value for cutaneous lesions only was 0.11 and ranged from -0.10 to -0.04 for the more severe conditions; these values were systematically lower than the TTO ( P=0.014). A large overall potential gain in QoL from treatment (partial response minus stable disease) was found for each condition to be reflected in both the TTO (from 0.31 to 0.55) and the rating scale (from 0.38 to 0.44). Respondents associate KS health states with extremely poor QoL and indicate that large gains are possible through modest treatment effects. While TTO returns higher values than the rating scale, potential gains from treatments were similar. The techniques appear to be suitable for application to QoL and economic evaluation of treatments of KS.  相似文献   
40.
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