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   33305篇
  免费   2092篇
  国内免费   264篇
耳鼻咽喉   447篇
儿科学   613篇
妇产科学   504篇
基础医学   4091篇
口腔科学   1597篇
临床医学   2750篇
内科学   8949篇
皮肤病学   397篇
神经病学   3362篇
特种医学   1332篇
外科学   5299篇
综合类   94篇
一般理论   6篇
预防医学   1387篇
眼科学   546篇
药学   1726篇
中国医学   72篇
肿瘤学   2489篇
  2023年   334篇
  2022年   540篇
  2021年   1262篇
  2020年   748篇
  2019年   1025篇
  2018年   1216篇
  2017年   964篇
  2016年   1072篇
  2015年   1134篇
  2014年   1465篇
  2013年   1796篇
  2012年   2803篇
  2011年   2697篇
  2010年   1511篇
  2009年   1373篇
  2008年   2156篇
  2007年   2268篇
  2006年   2051篇
  2005年   1855篇
  2004年   1655篇
  2003年   1505篇
  2002年   1308篇
  2001年   271篇
  2000年   245篇
  1999年   246篇
  1998年   242篇
  1997年   207篇
  1996年   154篇
  1995年   140篇
  1994年   129篇
  1993年   108篇
  1992年   123篇
  1991年   104篇
  1990年   83篇
  1989年   62篇
  1988年   93篇
  1987年   68篇
  1986年   53篇
  1985年   70篇
  1984年   54篇
  1983年   46篇
  1982年   48篇
  1981年   31篇
  1980年   24篇
  1979年   44篇
  1978年   30篇
  1977年   22篇
  1974年   24篇
  1973年   31篇
  1972年   26篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Whereas there is evidence that interpersonal communication, or conversation, influences predictors of alcohol consumption, the role of involvement in conversation effects remains unclear. This study explored how three aspects of involvement (topical relevance, or how relevant the topic of alcohol is; conversational relevance, or how relevant a conversation about alcohol is; and conversational effort, or how much effort people put into such a conversation), influence conversation effects. After assessing topical relevance, 46 same-sex dyads were requested to talk about the negative consequences of heavy drinking. Within each dyad, one participant was asked to take on an active talking role and the other participant a passive listening role. Next, conversational relevance, effort, and predictors of heavy drinking were measured. Results showed that participants who drank more alcohol found the topic of heavy drinking more relevant. This topical relevance increased conversational relevance and conversational effort. Conversational effort further increased when a talking role was assigned. Furthermore, participants who put more effort in the conversation and found it more relevant had more positive norms, identified more strongly with alcohol, and had higher intentions to drink. These findings suggest that more involvement in an alcohol-related conversation does not always lead to desirable outcomes.  相似文献   
2.
Sinus venosus atrial septal defect (SV‐ASD) usually coexists with partial anomalous pulmonary vein connection (PAPVC). It is a difficult diagnosis in transthoracic echocardiography (TTE) due to eccentric position of defects. We present a rare case of atypical anatomical variation in PAPVC, which was never described before. Two right pulmonary veins drained into superior vena cava, which overrode SV‐ASD and interatrial septum, a third pulmonary vein into the right atrium. Complete diagnosis could not be set after TTE, nor transesophageal echocardiography, whereas angio‐CT was finally conclusive. This diagnostic approach allowed the surgical planning.  相似文献   
3.
Abstract

Objective: To understand the origin of extremely high gonadotropin levels in a perimenopausal woman.

Methods: A 52-year-old woman with a 2?months of amenorrhea followed spontaneous menstrual cycles recovery was referred to our outpatient clinic with elevated follicle-stimulating hormone (FSH, 483 mUI/ml), luteinizing hormone (LH, 475 mUI/ml) and prolactin (PRL, 173?ng/ml). She was known to take levosulpiride. The gonadotropin levels did not fit with the clinical features.

Results: A gonadotroph tumor was ruled out. Further analysis confirmed constantly high FSH, LH and PRL levels. The measurements were repeated using different analytical platforms with different results. After serial dilutions, nonlinearity was present suggesting an immunoassay interference. After post-polyethylene glycol recovery, hormone levels appeared in the normal range. Anti-goat antibodies were recognized in the serum of the patient.

Conclusions: This case report shows a case of falsely abnormal high gonadotropin and PRL levels in a woman during menopause transition. In the clinical practice the evaluation of gonadotropin profile is not recommended at this age, but the abnormal levels stimulated further evaluation. An interference in the assay due to anti-goat antibodies resulted in abnormally high level of FSH and LH. A strict collaboration between clinicians and the laboratory is needed, when laboratory findings do not correspond to clinical findings.  相似文献   
4.
Graefe's Archive for Clinical and Experimental Ophthalmology - To estimate the impact of delayed care during the coronavirus disease 2019 (COVID-19) pandemic on the outcomes of patients with...  相似文献   
5.
6.
7.
8.
This meta-analysis focuses on the accuracy of upgrading to clinically significant prostate cancer (PCa) by multiparametric magnetic resonance imaging-targeted biopsy (MRI-TB) versus systematic biopsy (SB). We searched the Medline, Embase, Cochrane Central Register of Controlled Trials, Web of Science, Scopus, and Literatura Latino Americana em Ciências da Saúde databases through January 2020 for comparative, retrospective/prospective, paired-cohort, and randomized clinical trials with paired comparisons. The population consisted of patients with low-risk PCa in active surveillance with at least 1 index lesion on imaging. We evaluated the quality of evidence by using the Quality Assessment of Diagnostic Accuracy Studies-2 score. Group comparisons considered the differences between the area under the curve summary receiver operating characteristic curve in a 2-tailed method. We also compared the positive predictive value of the best single method (MRI-TB or SB) and the referral study test (combined biopsy, a combination of MRI-TB and SB). The meta-analysis included 6 studies enrolling 741 patients. The pooled sensitivity for the 2 groups was 0.79 (95% confidence interval, 0.74-0.83; I2 = 75%) and 0.67 (95% confidence interval, 0.63-0.74; I2 = 55.4%), respectively. The area under the curve for the MRI-TB and SB groups were 0.99 and 0.92 (P < .001), respectively. The positive predictive value for the MRI-TB and combined biopsy groups were similar. The accumulated evidence suggests better results for MRI-TB compared with SB. Therefore, use of MRI-TB alone may be preferable in patients in active surveillance harboring low-risk PCa.  相似文献   
9.
10.
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