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   12782篇
  免费   879篇
  国内免费   24篇
耳鼻咽喉   88篇
儿科学   408篇
妇产科学   370篇
基础医学   1570篇
口腔科学   139篇
临床医学   2244篇
内科学   2042篇
皮肤病学   165篇
神经病学   1214篇
特种医学   272篇
外科学   1308篇
综合类   223篇
一般理论   24篇
预防医学   1508篇
眼科学   283篇
药学   843篇
  2篇
中国医学   7篇
肿瘤学   975篇
  2023年   56篇
  2022年   130篇
  2021年   218篇
  2020年   139篇
  2019年   229篇
  2018年   261篇
  2017年   211篇
  2016年   205篇
  2015年   236篇
  2014年   329篇
  2013年   582篇
  2012年   780篇
  2011年   900篇
  2010年   476篇
  2009年   457篇
  2008年   815篇
  2007年   824篇
  2006年   891篇
  2005年   867篇
  2004年   913篇
  2003年   852篇
  2002年   757篇
  2001年   176篇
  2000年   117篇
  1999年   145篇
  1998年   161篇
  1997年   136篇
  1996年   99篇
  1995年   106篇
  1994年   78篇
  1993年   81篇
  1992年   110篇
  1991年   81篇
  1990年   87篇
  1989年   74篇
  1988年   78篇
  1987年   68篇
  1986年   80篇
  1985年   67篇
  1984年   66篇
  1983年   69篇
  1982年   56篇
  1981年   67篇
  1980年   72篇
  1979年   41篇
  1978年   44篇
  1977年   38篇
  1976年   31篇
  1975年   33篇
  1973年   37篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
To assess the magnitude and nature of interpersonal violence resulting in hospitalisation of children and to identify subgroups at risk of repeat hospital admissions, a population-based, retrospective study of all violence hospitalisations in Western Australia for children aged 9 years or less was undertaken, using the 1990–2004 linked data retrieved from the Western Australian Mortality Database and the Hospital Morbidity Data System.
Of the 747 patients aged <10 years incurring 834 hospitalisations for the consequences of violence during the study period, 570 (76%) were less than 4 years of age. A total of 43 deaths from violence were recorded and 74 (9%) patients were admitted for more than one episode of violence. Victims aged 0–4 years from rural (hazard ratio [HR] = 2.72; 95% confidence interval [CI] 1.35, 5.43) and remote parts (HR = 2.79; 95% CI 1.25, 6.25) of the state were at increased risk of a subsequent admission for violence compared with those residing within the metropolitan area. Indigenous children aged 5–9 years were significantly more likely (HR = 3.57; 95% CI 1.14, 11.13) to incur a second hospitalisation for violence than their non-Indigenous counterparts. The identification of young victim subgroups at high risk of repeat hospitalisations is important for developing intervention strategies to reduce the burden of interpersonal violence. Young children aged 0–4 years living in rural and remote locations and Indigenous children aged 5–9 years should be specifically targeted for attention.  相似文献   
12.
Zusammenfassung Die 20. notfallmedizinische Jahrestagung der Arbeitsgemeinschaft Südwestdeutscher Notärzte (agswn) behandelte auch in diesem Jahr aktuelle berufspolitische Themen. Aktuelle Entwicklungen zur Verbesserung der Arbeitsabläufe in den Leitstellen wurden dargestellt, EDV-gestützte Systeme zur Notrufabfrage, die Vernetzung der Leitstellen und technische Verbesserungen der Leitstellensysteme genannt. Die Gefahren im Rettungsdienst waren ein weiterer Schwerpunkt der Tagung. Eine Ansteckungsgefahr bei Infektionstransporten bei MRSA-Patienten ist bei sachgemäßem Verhalten nicht zu befürchten. Weiterhin wurden die Möglichkeiten des terroristischen Einsatzes von biologischen Waffen realistisch deutlich relativiert. Amoklagen stellen dagegen eine nur schwer kalkulierbare Gefahrensituation dar. Als 3. Themenschwerpunkt wurden die besonderen Herausforderungen der Notfallmedizin im DRG-Zeitalter umrissen. Die Änderung des Einsatzspektrums und die Reduktion von Notarztstandorten erfordert die Bildung von Kompetenzzentren und eine hohe Qualifikation der Notärzte.  相似文献   
13.
Within the scope of the symposium “Rescue Medicine in Germany” (held at the Reisensburg near Ulm in 2002), the need for a standardized data acquisition set for prehospital cardiac arrest patients was identified. Therefore, the working group “Emergency Medicine” of the German Society of Anesthesiology and Intensive Care Medicine (DGAI) created a nationwide data acquisition system for primary medical care in prehospital cardiac arrest patients treated with cardiopulmonary resuscitation procedures. The system is in full accordance with the “Utstein style.” Integration of this data acquisition system, for example into the “Dortmund protocol,” is providing a standardized data web base of all acquired prehospital data analyze and to compare processing and structural quality. As additional modules for this nationwide data web base system, an inhospital module “further clinical treatment” and a “long-term follow-up” module are currently in the developmental process.  相似文献   
14.
15.
BACKGROUND & AIMS: The aim of this study was to assess the validity of frozen section analysis of endoscopic mucosal resection (EMR) specimens from Barrett's esophagus as compared with permanent sections for the detection of neoplasia. Frozen sections help to give immediate feedback for surgical procedures. It has not been determined whether EMR can be adequately interpreted by using frozen sections to aid endoscopists in completely resecting neoplastic lesions. METHODS: EMR specimens from Barrett's esophagus with high-grade dysplasia (HGD) and/or carcinoma were tested by frozen section. Pathologists evaluated EMR specimens for the depth of invasion as well as the appearance of clear margins of resection. The kappa statistic was calculated to assess the degree of agreement between the frozen section and permanent section diagnoses. RESULTS: Twenty-three consecutive patients underwent 30 EMRs with frozen section diagnosis. Frozen section revealed a carcinoma in 7 specimens (23%) and dysplasia in 20 (66%). Permanent sections found carcinoma in 8 specimens (26%), dysplasia in 19 specimens (63%), and normal or nondysplastic Barrett's esophagus in the remainder. The kappa statistic for the depth of invasion of EMR specimens was 0.93 (near perfect agreement). The kappa statistic for the margins of the EMR specimens was 0.80 (excellent agreement). CONCLUSIONS: This study indicated that frozen section analysis of esophageal EMR specimens is valid as compared with permanent section. This technique might allow rapid evaluation about the degree and depth of involvement of cancers. This allows physicians to make decisions regarding further therapy if margins are involved or decrease the use of EMR for histologically benign-appearing lesions.  相似文献   
16.
OBJECTIVE: The purpose of this study was to investigate the effects of therapy balls as seating on in-seat behavior and legible word productivity of students with attention deficit hyperactivity disorder (ADHD). Additionally, social validity was assessed to evaluate teacher and student opinions regarding the intervention. METHOD: A single subject, A-B-A-B interrupted time series design was employed across 3 students (2 males, 1 female) with ADHD. The study was conducted in a 4th grade inclusive classroom during daily language arts. During phases 1 and 3, the 3 participants and all other class members sat on chairs (in-seat on chair); during phases 2 and 4, everyone sat on therapy balls (in-seat on ball). Dependent variables were in-seat behavior and legible word productivity. Data were graphed and visually analyzed for differences between phases. RESULTS: Results demonstrated increases in in-seat behavior and legible word productivity for the students with ADHD when seated on therapy balls. Social validity findings indicated that generally the teacher and students preferred therapy balls. CONCLUSION: This study provides evidence that use of therapy balls for students with ADHD may facilitate in-seat behavior and legible word productivity.  相似文献   
17.
18.
Antihypertensive drugs are commonly associated with adverse side effects in both clinical and laboratory studies. We investigated the sexual sequelae of several major classes of antihypertensive drugs (e.g., beta blockers, central alpha agonists, diuretics) in normal males and in hypertensive patients. We compared the effects of four widely used agents (methyldopa, propranolol, atenolol, hydrochlorothiazide-triamterene) and placebo, in a selected sample of 21 sexually dysfunctional male hypertensives, 13 of whom completed all five phases of the study. Each study drug was administered for a 1-month treatment period, followed by a 2-week, single-blind washout phase, according to a randomized, Latin square crossover design. Dependent variables for the study included a broad range of hormonal, NPT, and self-report measures of sexual response. Results indicated a lack of consistent drug effects on measures of sexual response, although more frequent sexual and nonsexual side effects were observed with methyldopa and propranolol. As in our previous studies, age was negatively correlated with both hormonal and NPT measures, whereas changes in blood pressure were not significantly related to sexual function scores. Results do not support the hypothesis that sexually dysfunctional males are at greater risk for adverse sexual sequelae when treated with centrally active agents or diuretics.  相似文献   
19.
Dysfunction of neutrophils in patients infected with human immunodeficiency virus is at least partly responsible for secondary microbial diseases in these individuals, including invasive gastrointestinal (GI) candidiasis. Immunoregulatory disturbances associated with the development of AIDS in human immunodeficiency virus-infected patients exacerbates Candida albicans infection of the upper GI tract and frequently leads to oropharyngeal and esophageal candidiasis. In this article, we present the first report of a murine model of invasive GI candidiasis associated with an AIDS-related murine immunodeficiency syndrome that results from infection of C57BL/6 mice with a previously described retrovirus complex (LP-BM5). Mice of the inbred strain were infected with C. albicans by oral-intragastric inoculation as infants and with the retrovirus by the intraperitoneal route 30 days later. Control mice of the same strain were infected with C. albicans as above and subsequently infected with the avirulent, ecotropic helper virus (MBI-5). Animals were killed 90 days after retroviral challenge. Total and differential blood cell counts, CD4+ T-cell counts in the spleen, and the histopathology of the gastric mucosa of experimental and control animals were determined. The virulent LP-BM5-infected animals developed murine AIDS and showed eruptive and suppurative lesions, with associated C. albicans mainly in regions of the cardial-atrium fold of the stomach. Well-defined abscesses with entrapped C. albicans hyphae were observed in the region of the cardial-atrium fold of control mice. A significant increase in the number of C. albicans CFU in homogenized and plated segments of the GI tract was recognized in mice with murine AIDS versus the control animals. The murine model of GI candidiasis reported here permits examination of the nature of C. albicans interaction with the gastric mucosa both in the immunocompetent host under conditions in which the yeast exists predominantly as a commensal organism and in the immunosuppressed host during progressive stages of AIDS induced by a retroviral infection.  相似文献   
20.
Women with polycystic ovary syndrome (PCOS) are markedly insulin-resistant, but the molecular mechanisms of these changes and their relationship to the hyperandrogenic state remain to be clarified. Mutations have recently been identified in the insulin receptor gene of patients with extreme forms of insulin resistance associated with hyperandrogenism (eg, type A insulin resistance), and these mutations account for the insulin resistance in such patients. We performed this study to determine whether mutations in the coding portion of the insulin receptor gene were responsible for insulin resistance in PCOS. Insulin binding studies using cultured skin fibroblasts of three obese (body mass index > 27 kg/m2) women with PCOS (ie, mild hyperandrogenemia and chronic anovulation of unknown etiology) and documented insulin resistance showed no apprarent abnormalities in either the number or affinity of insulin binding sites. Direct sequencing of all 22 exons of the insulin receptor gene from two of the women with PCOS did not reveal any mutations. Furthermore, both alleles of the gene were expressed at equal levels. In a third insulin-resistant PCOS woman, there was no evidence for a mutation in the coding portion of the insulin receptor gene as determined by denaturing gradient gel electrophoresis (DGGE). We conclude that the insulin resistance in these PCOS women was caused by a defect extrinsic to the insulin receptor.  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