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   205190篇
  免费   3003篇
  国内免费   96篇
耳鼻咽喉   1609篇
儿科学   7366篇
妇产科学   3353篇
基础医学   20300篇
口腔科学   1986篇
临床医学   15389篇
内科学   37669篇
皮肤病学   854篇
神经病学   19464篇
特种医学   10162篇
外科学   33802篇
综合类   2590篇
一般理论   72篇
预防医学   20131篇
眼科学   3135篇
药学   11287篇
中国医学   647篇
肿瘤学   18473篇
  2023年   149篇
  2022年   235篇
  2021年   730篇
  2020年   410篇
  2019年   725篇
  2018年   22641篇
  2017年   17876篇
  2016年   20083篇
  2015年   1644篇
  2014年   1887篇
  2013年   2149篇
  2012年   9189篇
  2011年   23182篇
  2010年   20036篇
  2009年   12544篇
  2008年   21456篇
  2007年   23752篇
  2006年   2595篇
  2005年   4214篇
  2004年   5195篇
  2003年   6083篇
  2002年   4179篇
  2001年   560篇
  2000年   633篇
  1999年   456篇
  1998年   548篇
  1997年   481篇
  1996年   323篇
  1995年   336篇
  1994年   292篇
  1993年   240篇
  1992年   215篇
  1991年   273篇
  1990年   287篇
  1989年   215篇
  1988年   178篇
  1987年   163篇
  1986年   140篇
  1985年   152篇
  1984年   175篇
  1983年   142篇
  1982年   162篇
  1981年   123篇
  1980年   136篇
  1979年   69篇
  1978年   79篇
  1977年   61篇
  1974年   61篇
  1938年   65篇
  1932年   61篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
991.
Radiation-induced breast angiosarcoma, or secondary angiosarcoma (SAS), is a rare entity with a high risk of metastatic recurrence. Herein, we describe the use of intraoperative fluorescence-based skin angiography to guide surgical resection following a novel immunotherapy-based regimen for SAS resulting in a complete pathological response.  相似文献   
992.
Background: Digit replantation affords the opportunity to restore hand function following amputation. To date, however, few studies have evaluated functional outcomes following replantation. Therefore, it was the objective of this study to perform a meta-analysis to better characterize the predictors of hand function. Methods: A literature search was performed using the PubMed database to identify studies that focused on digit amputation/replantation and functional outcomes. Studies were evaluated for patient- and injury-related factors and their respective effects on clinical outcomes of sensation, grip strength, and Disabilities of the Arm, Shoulder, and Hand (DASH) scores. Statistical analysis was conducted across the pooled data set to identify significant trends. Results: Twenty-eight studies representing 618 replanted digits were included in this study. We found the average grip strength was 78.7% (relative to contralateral), the average 2-point discrimination (2PD) was 7.8 mm, and the average DASH score was 12.81. After conducting statistical analysis, we found patients with more proximal injuries had lower grip strength scores (P < .05). We found 2PD scores were influenced by age, mechanism of injury, and amputation level (P < .05). Finally, we found DASH scores after replantation were predicted by mechanism of injury and level of amputation (P < .05). The following variables did not influence outcomes: gender, tobacco use, ischemia time, and digit number. Conclusions: Digit replant does not restore premorbid hand function but does result in adequate hand function. Expected functional outcomes following replant should be considered in the decision-making process. These data can help risk-stratify patients, guide postreplant expectations, and influence the decision for replantation.  相似文献   
993.
994.
995.
996.
IntroductionPatients with renal cell carcinoma (RCC) with level 3 or 4 caval thrombus have a poor prognosis, with reported five-year survival rates of 30–40%. The aim of this study was to assess the perioperative morbidity and long-term oncological outcomes for radical nephrectomy with resection of vena cava thrombus using a combined surgical approach, including extracorporeal circulation and deep hypothermic circulatory arrest.MethodsA retrospective review was performed of the institutional case log to identify all radical nephrectomies with caval thrombus performed from January 2006 to May 2020.ResultsTwenty-five patients were identified with level 2 thrombus in one (4%), level 3 thrombus in eight (32%), and level 4 in 16 (64%). The median followup was 20.6 months (range 0.2–133.3). The median age at surgery was 68.4 years (range 44.2–85.5). Twenty-one (84%) patients were symptomatic at presentation. Six (24%) patients had distant metastases at diagnosis. The median circulatory arrest time was 15 minutes (range 6–35). The 30-day grade ≥3 complication rate was 8%. The 30-day mortality rate was 8%. The one-year, two-year, three-year, and five-year recurrence-free survival (RFS) rates were 53%, 18%, 10%, and 10%, respectively. The median time to systemic treatment was 7.7 months (range 1.2–25.7). The one-year, two-year, three-year, and five-year overall survival (OS) rates were 70%, 43%, 36%, and 31%, respectively.ConclusionsRadical nephrectomy with resection of vena cava thrombus using extracorporeal circulation and deep hypothermic circulatory arrest is associated with some morbidity and mortality but remains a safe and effective strategy for advanced RCC patients who would otherwise be managed palliatively.  相似文献   
997.
Archives of Sexual Behavior - Men who have sex with men (MSM) experience high prevalence of sexual violence (SV), and SV has well-documented effects on health. Research gaps are especially evident...  相似文献   
998.
ObjectiveTo examine transmission and evolution of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in shipboard quarantine of the Diamond Princess cruise ship.MethodsWe obtained the full SARS-CoV-2 genome sequences of 28 samples from the Global Initiative on Sharing All Influenza Data database. The samples were collected between 10 and 25 February 2020 and came for individuals who had been tested for SARS-CoV-2 during the quarantine on the cruise ship. These samples were later sequenced in either Japan or the United States of America. We analysed evolution dynamics of SARS-CoV-2 using computational tools of phylogenetics, natural selection pressure and genetic linkage.FindingsThe SARS-CoV-2 outbreak in the cruise most likely originated from either a single person infected with a virus variant identical to the WIV04 isolates, or simultaneously with another primary case infected with a virus containing the 11083G > T mutation. We identified a total of 24 new viral mutations across 64.2% (18/28) of samples, and the virus evolved into at least five subgroups. Increased positive selection of SARS-CoV-2 were statistically significant during the quarantine (Tajima’s D: −2.03, P < 0.01; Fu and Li’s D: −2.66, P < 0.01; and Zeng’s E: −2.37, P < 0.01). Linkage disequilibrium analysis confirmed that ribonucleic acid (RNA) recombination with the11083G > T mutation also contributed to the increase of mutations among the viral progeny.ConclusionThe findings indicate that the 11083G > T mutation of SARS-CoV-2 spread during shipboard quarantine and arose through de novo RNA recombination under positive selection pressure.  相似文献   
999.
1000.
The purpose of this study was to assess the results of stuttering therapy for adults when a carefully delineated approach was utilized. Evaluations and measurements of the therapy groups were made nine months before therapy began, again at the end of this “waiting period” before therapy was initiated, at the end of the nine-month therapy period, and nine months after the close of therapy. Viewing all sixteen subjects as one group, there was a statistically significant reduction in stuttering during the therapy period. Taking severity into consideration, Group I (more severe) showed a significant improvement during therapy but regressed slightly during the follow-up period. Group II (less severe) improved during therapy and continued to improve during the follow-up period; however, the change never reached statistical significance. Responses to self- report procedures revealed significant decreases in avoidance behavior and stuttering, significant increases in the enjoyment of speaking, and significant improvement in attitudes toward stuttering, which was not related differentially to stuttering severity. Certain changes to make therapy more effective are discussed.  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