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   296254篇
  免费   17172篇
  国内免费   412篇
耳鼻咽喉   4205篇
儿科学   10286篇
妇产科学   10244篇
基础医学   44980篇
口腔科学   7493篇
临床医学   24152篇
内科学   55772篇
皮肤病学   6310篇
神经病学   21050篇
特种医学   11612篇
外国民族医学   43篇
外科学   46651篇
综合类   7765篇
现状与发展   1篇
一般理论   160篇
预防医学   19911篇
眼科学   6943篇
药学   20863篇
中国医学   787篇
肿瘤学   14610篇
  2018年   3616篇
  2017年   2651篇
  2016年   3070篇
  2015年   3488篇
  2014年   4573篇
  2013年   7204篇
  2012年   9058篇
  2011年   9446篇
  2010年   6123篇
  2009年   5544篇
  2008年   8670篇
  2007年   9516篇
  2006年   9363篇
  2005年   8955篇
  2004年   8658篇
  2003年   8164篇
  2002年   7761篇
  2001年   13319篇
  2000年   13650篇
  1999年   11418篇
  1998年   3023篇
  1997年   2789篇
  1996年   2637篇
  1995年   2547篇
  1994年   2344篇
  1992年   8315篇
  1991年   8449篇
  1990年   8261篇
  1989年   8077篇
  1988年   7314篇
  1987年   7077篇
  1986年   6720篇
  1985年   6517篇
  1984年   4761篇
  1983年   4118篇
  1982年   2470篇
  1979年   4427篇
  1978年   3228篇
  1977年   2731篇
  1976年   2503篇
  1975年   2833篇
  1974年   3352篇
  1973年   3362篇
  1972年   3118篇
  1971年   2949篇
  1970年   2838篇
  1969年   2581篇
  1968年   2538篇
  1967年   2373篇
  1966年   2264篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
72.
BACKGROUND: Until there is a definitive demonstration that early diagnosis and treatment of prostate cancer reduces disease-related mortality, it is imperative to promote informed screening decisions by providing balanced information about the potential benefits and risks of prostate cancer screening. Within a community/academic collaboration, we conducted a randomized trial of a printed booklet and a videotape that were designed for African American (AA) men. The purpose of the trial was to determine the effect of the interventions on knowledge, decisional conflict, satisfaction with the screening decision, and self-reported screening. METHODS: Participants were 238 AA men, ages 40 to 70 years, who were members of the Prince Hall Masons in Washington, DC. Men were randomly assigned to the (a) video-based information study arm, (b) print-based information study arm, or (c) wait list control study arm. Intervention materials were mailed to men at home. Assessments were conducted at baseline, 1 month, and 12 months postintervention. Multivariate analyses, including ANCOVA and logistic regression, were used to analyze group differences. RESULTS: The booklet and video resulted in a significant improvement in knowledge and a reduction in decisional conflict about prostate cancer screening, relative to the wait list control. Satisfaction with the screening decision was not affected by the interventions. Self-reported screening rates increased between the baseline and the 1-year assessment, although screening was not differentially associated with either of the interventions. In exploratory analyses, prostate-specific antigen testing at 1 year was more likely among previously screened men and was associated with having low baseline decisional conflict. CONCLUSIONS: This study represents one of the first randomized intervention trials specifically designed to address AA men's informed decision making about prostate cancer screening. We have developed and evaluated culturally sensitive, balanced, and disseminable materials that improved knowledge and reduced decisional conflict about prostate cancer screening among AA men. Due to the high incidence and mortality rates among AA men, there is a need for targeted educational materials, particularly materials that are balanced in terms of the benefits and risks of screening.  相似文献   
73.
OBJECTIVE: To evaluate the reproducibility of sonographic measurement of the lower uterine segment in pregnant women at term. METHODS: Two independent observers performed transabdominal sonography on 129 women between 36 and 38 weeks of gestation who had had a previous Cesarean section. Sonography was performed when the patients had a full and a half-full bladder; in 100 patients, the measurements were also performed transvaginally, with the patients having an empty bladder. Agreement was quantified by the intraclass correlation coefficient and, using a cut-off of 3.5 mm, by the kappa coefficient. RESULTS: The intraobserver agreement was generally high (intraclass correlation coefficient > 0.90). The interobserver agreement was higher on transvaginal (intraclass correlation coefficient, 0.94) compared with transabdominal (0.70 and 0.84, with full and half-full bladder, respectively) ultrasound. The kappa coefficient was 0.75 transvaginally, compared with 0.34 and 0.54 using the transabdominal approach, with full and half-full bladder, respectively. CONCLUSION: The agreement between two observers for sonographic transvaginal measurement of the lower uterine segment can be considered good, compared with poor to moderate agreement using the transabdominal approach.  相似文献   
74.
75.
We report a case of a prepubertal girl with juvenile primary hypothyroidism presenting as ovarian cysts and precocious puberty. The 7-year-old female was referred to our clinic because of a pelvic/abdominal mass and vaginal bleeding. Besides these findings, on physical examination we noticed the thyroid gland globally increased and the presence of secondary sexual characteristics. Based upon the clinical profile and investigations, the patient was diagnosed with juvenile primary hypothyroidism due to autoimmune thyroiditis. The cysts and precocious puberty resolved spontaneously after the simple replacement of thyroid hormone. It is important to bear in mind hypothyroidism in cases of girls presenting ovarian cysts and precocious puberty in order to avoid unnecessary surgery on the ovaries.  相似文献   
76.
The purpose of this study was to predict lymphatic involvement in endometrial cancer using clinicopathologic variables of patients treated with surgical staging. Overall, 461 patients treated with an initial surgical staging procedure including complete pelvic-para-aortic lymphadenectomy were included. The mean number of resected lymph nodes was 27 (median 26; range 15-83), and 54 patients (12%) had lymphatic involvement. Of these patients, 32 had only pelvic, 15 had both pelvic and para-aortic, and 7 had isolated para-aortic metastases. In the multivariate analysis, deep myometrial invasion (P= 0.02), lymphvascular space invasion (P= 0.001), positive peritoneal cytology (P= 0.002), and cervical involvement (P= 0.003) predicted retroperitoneal lymph node metastasis (RLN) significantly. Two hundred seventy-four patients (59.4%) had at least one of these poor prognostic factors identified by multivariate analysis. In this patient population, 53 (19.3%) had lymphatic involvement compared to 1 patient in the group of 187 patients with low-risk criteria. Ninety-eight percent of patients with RLN were predicted by this model, and with the advent of accurate diagnostic techniques, 40% of patients could be saved from undergoing lymphadenectomy.  相似文献   
77.
The main objectives of the European Committee on Antimicrobial Susceptibility Testing (EUCAST) are to harmonise breakpoints for antimicrobial agents in Europe, and to act as the breakpoint committee for the European Medicines Agency (EMEA) during the registration of new antimicrobial agents. Detailed EUCAST procedures for harmonising and setting breakpoints for antimicrobial agents are available on the EUCAST website. Beginning with the current issue, a series of EUCAST Technical Notes will be published in CMI, based on the rationale documents produced by EUCAST for each of the antimicrobial agents studied, with the aim of highlighting important background information underlying decisions on breakpoints made by EUCAST.  相似文献   
78.
In order to assess the state and pathology of the woman's pelvis minor, a number of methods are commonly used among practitioners, encompassing clinical exploration, radiology, MRN, urodynamics, endoscopy and echography.

Echography has been poorly used in clinical pelvic exploration and its reliability is actually a matter of controversy 1. However, echographic surveys can provide us with valuable gynecological data on the state and pathologies of the soft pelvis, within the genital regions or even going beyond them, i.e. the rectal channel, bladder, urethra, anus, vascular plexuses, and all of their supporting tissues.

At our research unit, we have been employing Transvaginal Ultrasound echography (TVU) for a long time in conjunction with other pelvis-focused methods in order to study different kinds of pelvic alterations. TVU has proven to be friendly to use, fast, harmless and inexpensive, allowing serial explorations and producing high-quality dynamic images (loop-cinema, video-tape). Furthermore, this method is fairly aseptic in that the occurrence of faeces in the rectal ampolla is not a nuisance but a bonus in tracking the contours of the rectum walls and other topographical features which would be otherwise difficult to survey.

A complete pelvic floor TVU may add no longer than 5-8 minutes to a routine gynecological examination, can be implemented by the general gynecologist and generates data that can be further studied by the appropriate specialist for a more insightful evaluation 2.  相似文献   
79.
80.
Pyogenic liver abscess: an improvement in prognosis   总被引:3,自引:0,他引:3  
Forty-six patients with pyogenic liver abscess have been treated at Paul Brousse Hospital between 1966 and 1986. The overall mortality was 24 per cent, all 11 deaths occurring in 24 patients seen prior to 1978 when there was often a considerable delay in the diagnosis of liver abscess (mean 90 +/- 71 days). In seven patients the diagnosis was not made until post-mortem examination. The mainstay of treatment was surgical drainage. Since 1978 high resolution imaging techniques for the liver, and in particular ultrasound, have been available. The diagnostic delay has been significantly reduced (mean 28 +/- 20 days, P less than 0.01). Patients are receiving definitive treatment at an earlier stage in the evolution of the disease process, with fewer established complications prior to treatment (P less than 0.05). Percutaneous drainage under ultrasound control is the preferred initial drainage procedure in high-risk patients. There have been no deaths in 22 patients treated for pyogenic liver abscess since 1978 (P less than 0.001).  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