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   62519篇
  免费   4403篇
  国内免费   137篇
耳鼻咽喉   508篇
儿科学   2421篇
妇产科学   2179篇
基础医学   7729篇
口腔科学   839篇
临床医学   10461篇
内科学   11018篇
皮肤病学   1004篇
神经病学   5984篇
特种医学   1129篇
外国民族医学   33篇
外科学   5283篇
综合类   739篇
现状与发展   1篇
一般理论   112篇
预防医学   8864篇
眼科学   716篇
药学   3553篇
  1篇
中国医学   99篇
肿瘤学   4386篇
  2023年   413篇
  2022年   285篇
  2021年   1168篇
  2020年   895篇
  2019年   1398篇
  2018年   1558篇
  2017年   1154篇
  2016年   1233篇
  2015年   1367篇
  2014年   1907篇
  2013年   3133篇
  2012年   4455篇
  2011年   4711篇
  2010年   2485篇
  2009年   2332篇
  2008年   4142篇
  2007年   4585篇
  2006年   4468篇
  2005年   4371篇
  2004年   4125篇
  2003年   3904篇
  2002年   3709篇
  2001年   478篇
  2000年   322篇
  1999年   457篇
  1998年   675篇
  1997年   492篇
  1996年   440篇
  1995年   440篇
  1994年   441篇
  1993年   419篇
  1992年   324篇
  1991年   271篇
  1990年   262篇
  1989年   212篇
  1988年   202篇
  1987年   212篇
  1986年   197篇
  1985年   220篇
  1984年   247篇
  1983年   259篇
  1982年   329篇
  1981年   284篇
  1980年   230篇
  1979年   158篇
  1978年   142篇
  1977年   144篇
  1976年   123篇
  1975年   99篇
  1974年   102篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
2.
3.
4.
5.
6.
Background The B-MaP-C study aimed to determine alterations to breast cancer (BC) management during the peak transmission period of the UK COVID-19 pandemic and the potential impact of these treatment decisions.Methods This was a national cohort study of patients with early BC undergoing multidisciplinary team (MDT)-guided treatment recommendations during the pandemic, designated ‘standard’ or ‘COVID-altered’, in the preoperative, operative and post-operative setting.Findings Of 3776 patients (from 64 UK units) in the study, 2246 (59%) had ‘COVID-altered’ management. ‘Bridging’ endocrine therapy was used (n = 951) where theatre capacity was reduced. There was increasing access to COVID-19 low-risk theatres during the study period (59%). In line with national guidance, immediate breast reconstruction was avoided (n = 299). Where adjuvant chemotherapy was omitted (n = 81), the median benefit was only 3% (IQR 2–9%) using ‘NHS Predict’. There was the rapid adoption of new evidence-based hypofractionated radiotherapy (n = 781, from 46 units). Only 14 patients (1%) tested positive for SARS-CoV-2 during their treatment journey.Conclusions The majority of ‘COVID-altered’ management decisions were largely in line with pre-COVID evidence-based guidelines, implying that breast cancer survival outcomes are unlikely to be negatively impacted by the pandemic. However, in this study, the potential impact of delays to BC presentation or diagnosis remains unknown.Subject terms: Breast cancer, Surgical oncology, Health care economics, Quality of life, Health policy  相似文献   
7.
According to global neuronal workspace (GNW) theory, conscious access relies on long-distance cerebral connectivity to allow a global neuronal ignition coding for conscious content. In patients with schizophrenia and bipolar disorder, both alterations in cerebral connectivity and an increased threshold for conscious perception have been reported. The implications of abnormal structural connectivity for disrupted conscious access and the relationship between these two deficits and psychopathology remain unclear. The aim of this study was to determine the extent to which structural connectivity is correlated with consciousness threshold, particularly in psychosis. We used a visual masking paradigm to measure consciousness threshold, and diffusion MRI tractography to assess structural connectivity in 97 humans of either sex with varying degrees of psychosis: healthy control subjects (n = 46), schizophrenia patients (n = 25), and bipolar disorder patients with (n = 17) and without (n = 9) a history of psychosis. Patients with psychosis (schizophrenia and bipolar disorder with psychotic features) had an elevated masking threshold compared with control subjects and bipolar disorder patients without psychotic features. Masking threshold correlated negatively with the mean general fractional anisotropy of white matter tracts exclusively within the GNW network (inferior frontal-occipital fasciculus, cingulum, and corpus callosum). Mediation analysis demonstrated that alterations in long-distance connectivity were associated with an increased masking threshold, which in turn was linked to psychotic symptoms. Our findings support the hypothesis that long-distance structural connectivity within the GNW plays a crucial role in conscious access, and that conscious access may mediate the association between impaired structural connectivity and psychosis.  相似文献   
8.
9.
10.
Optimal treatment of patients with various types of liver tumors or certain liver diseases frequently demands major liver resection, which remains a clinical challenge especially in children.Eighty seven consecutive pediatric liver resections including 51 (59%) major resections (resection of 3 or more hepatic segments) and 36 (41%) minor resections (resection of 1 or 2 segments) were analyzed. All patients were treated between January 2010 and March 2018. Perioperative outcomes were compared between major and minor hepatic resections.The male to female ratio was 1.72:1. The median age at operation was 20 months (range, 0.33–150 months). There was no significant difference in demographics including age, weight, ASA class, and underlying pathology. The surgical management included functional assessment of the future liver remnant, critical perioperative management, enhanced understanding of hepatic segmental anatomy, and bleeding control, as well as refined surgical techniques. The median estimated blood loss was 40 ml in the minor liver resection group, and 90 ml in major liver resection group (P < .001). Children undergoing major liver resection had a significantly longer median operative time (80 vs 140 minutes), anesthesia time (140 vs 205 minutes), as well as higher median intraoperative total fluid input (255 vs 450 ml) (P < .001 for all). Fourteen (16.1%) patients had postoperative complications. By Clavien-Dindo classification, there were 8 grade I, 4 grade II, and 2 grade III-a complications. There were no significant differences in complication rates between groups (P = .902). Time to clear liquid diet (P = .381) and general diet (P = .473) was not significantly different. There was no difference in hospital length of stay (7 vs 7 days, P = .450). There were no 90-day readmissions or mortalities.Major liver resection in children is not associated with an increased incidence of postoperative complications or prolonged postoperative hospital stay compared to minor liver resection. Techniques employed in this study offered good perioperative outcomes for children undergoing major liver resections.  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