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   3456篇
  免费   211篇
  国内免费   12篇
耳鼻咽喉   24篇
儿科学   121篇
妇产科学   229篇
基础医学   426篇
口腔科学   143篇
临床医学   225篇
内科学   709篇
皮肤病学   55篇
神经病学   147篇
特种医学   60篇
外科学   389篇
综合类   119篇
一般理论   3篇
预防医学   170篇
眼科学   252篇
药学   356篇
中国医学   19篇
肿瘤学   232篇
  2023年   13篇
  2022年   50篇
  2021年   120篇
  2020年   64篇
  2019年   84篇
  2018年   107篇
  2017年   67篇
  2016年   94篇
  2015年   96篇
  2014年   140篇
  2013年   167篇
  2012年   295篇
  2011年   278篇
  2010年   136篇
  2009年   99篇
  2008年   182篇
  2007年   206篇
  2006年   193篇
  2005年   177篇
  2004年   168篇
  2003年   161篇
  2002年   108篇
  2001年   61篇
  2000年   78篇
  1999年   58篇
  1998年   34篇
  1997年   24篇
  1996年   22篇
  1995年   19篇
  1994年   13篇
  1993年   20篇
  1992年   28篇
  1991年   23篇
  1990年   27篇
  1989年   29篇
  1988年   26篇
  1987年   14篇
  1986年   23篇
  1985年   13篇
  1984年   11篇
  1983年   8篇
  1977年   8篇
  1973年   10篇
  1972年   19篇
  1971年   16篇
  1970年   11篇
  1969年   13篇
  1968年   13篇
  1967年   8篇
  1966年   10篇
排序方式: 共有3679条查询结果,搜索用时 15 毫秒
1.
2.
BACKGROUND CONTEXT: Pseudoaneurysm of the aorta in association with vertebral tuberculosis is a rare phenomenon. With the resurgence of human immunodeficiency virus (HIV) and associated resistant tuberculosis, this life-threatening complication requires greater awareness. PURPOSE: Our purpose is to report the rare presentation and successful management of tubercular pseudoaneurysm of the aorta in association with vertebral tuberculosis, and to highlight the clinicoradiological features for early and prompt diagnosis of this potentially fatal, but treatable, disease. STUDY DESIGN: A single case report and overview of the disease comprises the design of this study. PATIENT SAMPLE: The patient, already surgically intervened, is a 27-year-old male with increasing abdominal and back pain, upper motor neuron signs, and constitutional signs and symptoms. OUTCOME MEASURES: At 33 months follow-up, there is complete resolution of the signs and symptoms, and the patient is back to his previous vocation. METHODS: The diagnosis was confirmed by magnetic resonance imaging and contrast computed tomography. Endoaneurysmorrhaphy of the pseudoaneurysm along with a complete course of antitubercular treatment was given to the patient, and he has presently been followed up for 33 months. RESULTS: The patient's signs and symptoms have been completely resolved without any recurrence. CONCLUSION: Despite the use of modern chemotherapy and imaging techniques, this disastrous complication still occurs and reinforces the need for early suspicion, diagnosis, surgical resection, and antitubercular therapy along with close postoperative follow-up to prevent recurrence. With the resurgence of HIV (and other immunocompromised states) associated and resistant tuberculosis, we should be more alert than ever to this life-threatening complication.  相似文献   
3.
The present study investigated the hypothesis that Staphylococcus aureus enterotoxin B (SEE) produces epithelial cell death and releases inflammatory cytokines that produce stromal infiltration during contact lens induced peripheral ulceration. Epithelial cells were incubated with different doses of SEB for various time periods. Culture supernatants were assayed for cytokines IL- lo, IL-6 and chemotactic agents IL-8 and LTB,. SEE induced the production of IL- I p and IL-8. Epithelial cells exposed for longer periods (48 h) with low concentrations of SEB produced significantly higher levels (N0.02) of IL-Ip and IL-8 (P<0.05) compared t o a 24 h exposure. SEB did not induce the production o f IL-6 and  相似文献   
4.
5.
Previous studies following single dose administration have suggested that the pharmacokinetics of various nifedipine formulations could be influenced by the timing of associated food consumption. In order more closely to reflect the clinical situation we have carried out a study at steady state using a 'biphasic' formulation comprising 'rapid' and 'retarded' drug release components. Fifteen normal subjects took 20 mg 'biphasic' nifedipine 12 hourly for 10 days. Studies were carried out on days 4, 7 and 10. On these days the nifedipine was taken 2 h or 1 h before or immediately following a light breakfast. A light breakfast influenced neither the rate nor the extent of nifedipine absorption nor the rate or extent of major metabolite appearance. We conclude that at steady state the timing of a light meal is unlikely to alter in any clinically important manner the pharmacokinetics of nifedipine released from 'biphasic' tablets.  相似文献   
6.
The role of interleukin 6 (IL-6) in the growth of five multiple myeloma-derived cell lines was characterized. The U266 and RPMI 8226 cell lines demonstrated increased DNA synthesis when cultured with exogenous IL-6, expressed IL-6 cell surface receptors (IL-6Rs) and expressed mRNA for IL-6R. However, these cells did not secrete detectable IL-6 protein, and a neutralizing antibody to IL-6 did not inhibit their growth. Three other myeloma-derived cell lines ARH-77, IM-9 and HS-Sultan did not respond to exogenous IL-6, secrete IL-6 or express cell surface IL-6Rs. The IL-6 responsive cell lines bore late B-cell surface antigens (Ags), CD38 and PCA-1, whereas those lines which were non-IL-6 responsive strongly expressed B1 (CD20) and B4 (CD19) Ags, representing earlier stages in B-cell differentiation. Finally, the two IL-6 responsive cell lines did not express Epstein-Barr virus (EBV) proteins; in contrast, EBV encoded proteins typically expressed during latency could be detected in the three non-IL-6 responsive lines, confirming infection with virus. These studies clarify the heterogeneity observed in the myeloma cell line phenotype and biology and suggest that the U266 and RPMI 8226 cell lines, which express IL-6 cell surface receptors and are IL-6 responsive, may be useful for further study of IL-6 signal transduction in and related IL-6 mediated growth of myeloma in vivo. In contrast, those cell lines which are IL-6-independent provide a model for further study of EBV transformation and IL-6-dependent growth mechanisms in malignancy.  相似文献   
7.
8.
9.
Cluster analysis in perimetry is a technique used in the evaluation of localised visual field loss. It has previously been applied to suprathreshold data and, unlike the indices currently available to indicate localised loss, it is influenced by the relative positions of individual defects. This paper describes a cluster analysis for use with data from Program 31 of the Octopus perimeter. To demonstrate the technique, sensitivity values of normal 60-year-old subject were altered to simulate localised loss. Illustrative examples of clinical cases are given, showing differing degrees of localised loss that do not influence the corrected loss variance (CLV) but influence the computed cluster parameters. It is hoped that the value of this form of analysis will be demonstrated in clinical follow-up of glaucoma patients.  相似文献   
10.
Patient response to interactive videodisc preparation for third molar extraction surgery was examined as a function of self-reported information-seeking style. Amount learned was compared among patients informed via an interactive videodisc, noninteractive videotape of the same material, or surgeon only. Anxiety levels and satisfaction with preparation were compared between the videodisc and videotape groups. At consultation, patients (n = 35) were randomly assigned to either the disc- or the tape-viewing group. First, subjects completed a demographic survey, state anxiety scale, quiz on knowledge about third molars and surgery risks and complications, and information-seeking scales. Immediately after viewing the video, subjects completed another anxiety scale and a multiple-choice quiz covering the material presented. Subsequently, another 25 patients undergoing the routine (surgeon-only) consultation procedure were given the same multiple-choice quiz following consultation. Quiz scores differed significantly among the groups; mean percent correct for the tape-viewing subjects was 85; for disc-viewing subjects 72.6; for surgeon-only subjects, 40. Self-rated information seeking was unrelated to amount of video viewed by disc subjects (on average, 64% of the videodisc was viewed), and disc subjects who rated themselves higher in information-seeking achieved the lowest postpreparation quiz scores. Subjects in the disc group were significantly more satisfied with the amount of preparation than the tape group. Although disc group subjects were significantly less knowledgeable following consultation than were tape group subjects, interactive videodisc preparation for third molar extraction appears to have some advantages over more traditional approaches. Further research is needed to determine whether this approach to preparing patients is suitable for widespread clinical use.  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