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   4429篇
  免费   295篇
  国内免费   6篇
耳鼻咽喉   28篇
儿科学   221篇
妇产科学   183篇
基础医学   606篇
口腔科学   81篇
临床医学   777篇
内科学   716篇
皮肤病学   122篇
神经病学   344篇
特种医学   51篇
外科学   412篇
综合类   60篇
一般理论   3篇
预防医学   619篇
眼科学   32篇
药学   191篇
中国医学   1篇
肿瘤学   283篇
  2023年   21篇
  2022年   36篇
  2021年   83篇
  2020年   54篇
  2019年   84篇
  2018年   94篇
  2017年   72篇
  2016年   102篇
  2015年   106篇
  2014年   147篇
  2013年   214篇
  2012年   284篇
  2011年   325篇
  2010年   166篇
  2009年   141篇
  2008年   263篇
  2007年   303篇
  2006年   313篇
  2005年   266篇
  2004年   304篇
  2003年   247篇
  2002年   272篇
  2001年   30篇
  2000年   16篇
  1999年   37篇
  1998年   57篇
  1997年   44篇
  1996年   53篇
  1995年   46篇
  1994年   43篇
  1993年   36篇
  1992年   23篇
  1991年   27篇
  1990年   25篇
  1989年   19篇
  1988年   22篇
  1986年   21篇
  1985年   17篇
  1984年   36篇
  1983年   17篇
  1982年   26篇
  1981年   24篇
  1980年   21篇
  1979年   17篇
  1978年   19篇
  1977年   18篇
  1976年   13篇
  1974年   17篇
  1971年   9篇
  1968年   9篇
排序方式: 共有4730条查询结果,搜索用时 31 毫秒
131.
Elevated IgA and IgM anticardiolipin antibodies in acute Kawasaki disease   总被引:1,自引:0,他引:1  
There is marked activation of the endothelium and immune system in Kawasaki disease. Anticardiolipin antibodies (aCL) can cause activation of the endothelium. We measured aCL levels in acute Kawasaki disease patients and compared them to other febrile patients to see whether their aCL responses were different. Twenty-one patients with acute Kawasaki disease and 16 patients with an acute febrile illness were recruited. The aCL levels were measured in the sera of febrile patients and in Kawasaki disease patients prior to immunoglobulin therapy. There was no significant difference between the IgG aCL levels (p = 0.87) between the Kawasaki disease and febrile patients. However, the IgM (p = 0.01) and IgA (p = 0.03) aCL were significantly higher in patients with acute Kawasaki disease than in febrile children. Elevation of IgA aCL has been reported in association with other vasculitides and IgA-secreting plasma cells have been demonstrated in the vascular tissue in Kawasaki disease.  相似文献   
132.
Questionnaires will be adequately filled in by patients if they are properly motivated and will provide useful information. We have found that when patients come for further consultations, much useful information is readily available from these cards to any doctor. We think that this data helps to establish the basis of a good doctor-patient relationship.

The trainees in the Watford area were concerned about the lack of family and social history contained in patients' records which may have been known by the partners, but was often not committed to paper and, if in the notes, was usually not easily found.

As a pilot study we decided to design a card to overcome some of these problems, and to test the acceptability and benefit of this method on newly registered patients. The project was also planned as a learning situation for trainees.

  相似文献   
133.
134.
BACKGROUND: Previous studies document neuropsychological deficits associated with stimulant abuse, but findings are inconsistent. METHODS: We identified 50 twin pairs in which only 1 member had heavy stimulant abuse (cocaine and/or amphetamines) ending at least 1 year before the evaluation. The co-twin control research design controls for familial vulnerability and makes it easier to identify neuropsychological deficits that are consequences of stimulant abuse. Subjects were administered an extensive neuropsychological test battery organized into the following 5 functions: attention, executive functioning, motor skills, intelligence, and memory. RESULTS: Multivariate tests showed that abusers performed significantly worse than nonabusers on functions of attention and motor skills. Within each of these functions, univariate tests showed that abusers performed significantly worse on certain tests of motor skills and attention. In contrast, abusers performed significantly better on one test of attention measuring visual vigilance. Within the abuser group, higher levels of stimulant use were largely uncorrelated with neuropsychological test scores, although a few significant correlations indicated better functioning with more stimulant use. CONCLUSIONS: With ideal controls, this study demonstrates that deficits in attention and motor skills persist after 1 year of abstinence from stimulant use and raises hypotheses regarding relative strengths on a vigilance task among abusers.  相似文献   
135.
The Charcot‐Marie‐Tooth disease Pediatric Scale (CMTPedS) is a Rasch‐built clinical outcome measure of disease severity. It is valid, reliable, and responsive to change for children and adolescents aged 3 to 20 years. The aim of this study was to translate and validate an Italian version of the CMTPedS using a validated framework of transcultural adaptation. The CMTPedS (Italian) was translated and culturally adapted from source into Italian by two experts in CMT with good English language proficiency. The two translations were reviewed by a panel of experts in CMT. The agreed provisional version was back translated into English by a professional translator. The definitive Italian version was developed during a consensus teleconference by the same panel. CMT patients were assessed with the final version of the outcome measure and a subset had a second assessment after 2 weeks to evaluate test‐retest reliability. Seventeen patients with CMT aged 5 to 20 years (eight female) were evaluated with the CMTPedS (Italian), and test‐retest was performed in three patients. The CMTPedS (Italian) showed a high test‐retest reliability. No patient had difficulty in completing the scale. The instructions for the different items were clearly understood by clinicians and therefore the administration of the outcome measure was straight forward and easily understood by the children assessed. The CMTPedS (Italian) will be used for clinical follow‐up and in clinical research studies in the Italian population. The data is fully comparable to that obtained from the English language version.  相似文献   
136.
137.
Ultrasound (US) B-mode images distal to smooth, rounded cavities, such as cysts, containing a fluid with a speed of sound mismatch to the surrounding tissue, often exhibit a "refractile" edge shadowing artefact. This usually appears as narrow, hypoechoic, shadow lines extending a significant distance distal to the lateral edges of the fluid cavity and parallel to the US beam. The true reasons for this artefact are likely to be complex and to vary from case to case, with many different explanations found in the literature. However, we present a simplified theoretical model for the phenomenon based on a pulsed, finite-beam solution of US scattering from circular fluid-filled cylinders that suggests that "edge" shadows can occur distal not only to edges but also to points where the incident beam intersects the cavity near to the critical angle. Both mechanisms support the view that edge shadows can arise from the combination of unusually high wavefront spreading and the speckle-generating nature of the surrounding tissue. In vitro data from a tissue-mimicking phantom confirms that the edge shadow structure depends on the sign of the speed of sound contrast between the cylinder fluid and the surrounding medium.  相似文献   
138.
139.
The incidence of oral candidosis has increased in recent years, largely as a result of the emergence of human immunodeficiency virus infection and the more widespread use of immunosuppressive chemotherapy. This development has been associated with a need for more reliable methods for the detection of Candida. The present study assessed the performance of a real-time PCR and two block-based PCRs for the detection of Candida in 193 concentrated oral rinse culture (CRC) specimens. A total of 102 CRC specimens were positive by culture for Candida; and 96, 90, and 75 of these were also positive by real-time, N18-specific, and internal transcribed spacer (ITS)-specific PCRs, respectively. The five false-negative results by the real-time PCR were all non-Candida albicans positive by culture. Of the 91 culture-negative CRC specimens, 20, 41, and 44 were positive by the real-time PCR and the N18- and ITS-specific PCRs, respectively. All three PCRs detected fungal DNA in 8 culture-negative CRC specimens, with a further 30 being positive by two of the three PCRs. A total of 32 CRC specimens were Candida free by all methods. In summary, a real-time PCR that provides a sensitive, specific, and rapid alternative technique for detection of Candida in the mouth is described.  相似文献   
140.
We have previously shown that young adults living in a rural area of northern Malawi showed greater gamma interferon (IFN-gamma) responses to purified protein derivatives (PPD) prepared from environmental mycobacteria than to PPD from Mycobacterium tuberculosis. In order to define the mycobacterial species to which individuals living in a rural African population have been exposed and sensitized, we tested T-cell recognition of recombinant and purified antigens from M. tuberculosis (38 kDa, MPT64, and ESAT-6), M. bovis (MPB70), M. bovis BCG (Ag85), and M. leprae (65 kDa, 35 kDa, and 18 kDa) in >600 non-M. bovis BCG-vaccinated young adults in the Karonga District of northern Malawi. IFN-gamma was measured by enzyme-linked immunosorbent assay (ELISA) in day 6 supernatants of diluted whole-blood cultures. The recombinant M. leprae 35-kDa and 18-kDa and purified native M. bovis BCG Ag85 antigens induced the highest percentages of responders, though both leprosy and bovine tuberculosis are now rare in this population. The M. tuberculosis antigens ESAT-6 and MPT64 and the M. bovis antigen MPB70 induced the lowest percentages of responders. One of the subjects subsequently developed extrapulmonary tuberculosis; this individual had a 15-mm-diameter reaction to the Mantoux test and responded to M. tuberculosis PPD, Ag85, MPT64, and ESAT-6 but not to any of the leprosy antigens. We conclude that in this rural African population, exposure to M. tuberculosis or M. bovis is much less frequent than exposure to environmental mycobacteria such as M. avium, which have antigens homologous to the M. leprae 35-kDa and 18-kDa antigens. M. tuberculosis ESAT-6 showed the strongest association with the size of the Mantoux skin test induration, suggesting that among the three M. tuberculosis antigens tested it provided the best indication of exposure to, or infection with, M. tuberculosis.  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