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   219853篇
  免费   4580篇
  国内免费   2854篇
耳鼻咽喉   1641篇
儿科学   7239篇
妇产科学   3443篇
基础医学   20455篇
口腔科学   2106篇
临床医学   18198篇
内科学   35844篇
皮肤病学   1167篇
神经病学   18206篇
特种医学   10546篇
外国民族医学   16篇
外科学   32482篇
综合类   12595篇
现状与发展   8篇
一般理论   1篇
预防医学   22148篇
眼科学   3953篇
药学   14783篇
  54篇
中国医学   3307篇
肿瘤学   19095篇
  2024年   56篇
  2023年   326篇
  2022年   1081篇
  2021年   1563篇
  2020年   1323篇
  2019年   1055篇
  2018年   22926篇
  2017年   18608篇
  2016年   20547篇
  2015年   2773篇
  2014年   3316篇
  2013年   3416篇
  2012年   10786篇
  2011年   25292篇
  2010年   22162篇
  2009年   14330篇
  2008年   22783篇
  2007年   24665篇
  2006年   3448篇
  2005年   4529篇
  2004年   5184篇
  2003年   5996篇
  2002年   3859篇
  2001年   1342篇
  2000年   1242篇
  1999年   774篇
  1998年   587篇
  1997年   579篇
  1996年   378篇
  1995年   337篇
  1994年   336篇
  1993年   175篇
  1992年   161篇
  1991年   188篇
  1990年   174篇
  1989年   121篇
  1988年   104篇
  1987年   76篇
  1986年   44篇
  1985年   54篇
  1984年   37篇
  1983年   26篇
  1982年   28篇
  1980年   43篇
  1974年   24篇
  1938年   60篇
  1937年   25篇
  1934年   30篇
  1932年   56篇
  1930年   46篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.

Introduction  

This paper presents the results of a study on the psychometric properties of an authorized Spanish version of the McMaster Family Assessment Device, a self-report measure of family functioning.  相似文献   
92.
93.
94.

Introduction  

Although ependymoma is the third most common pediatric brain tumor, we know little about the genetic/epigenetic basis of its initiation, maintenance, or progression. This is due in part to the heterogeneity of the disease, as well as the small sample size of the cohorts analyzed in most studies.  相似文献   
95.
96.
A benign esophageal leiomyoma with abnormally increased fluorine-18-fluorodeoxyglucose uptake on positron emission tomography (PET) was resected thoracoscopically. The tumor, of which the maximum standardized uptake value of the lesion was 4.7, was well defined and 38 mm in diameter. Neither mitotic activity nor degeneration was found histologically; and immunoreactivity for CD34, CD117, MIB-1, and glucose transporter-1 was negative immunohistochemically. A diagnosis of gastrointestinal stromal tumor was ruled out by an oncogenic kinase gene mutation study. This case cautions against PET-dependent evaluation for malignant potential of esophageal submucosal tumors.  相似文献   
97.
98.
Some investigators have suggested that preoperative chemotherapy for hepatic colorectal metastases may cause hepatic injury and increase perioperative morbidity and mortality. The objective of the current study was to examine whether treatment with preoperative chemotherapy was associated with hepatic injury of the nontumorous liver and whether such injury, if present, was associated with increased morbidity or mortality after hepatic resection. Two-hundred and twelve eligible patients who underwent hepatic resection for colorectal liver metastases between January 1999 and December 2005 were identified. Data on demographics, clinicopathologic characteristics, and preoperative chemotherapy details were collected and analyzed. The majority of patients received preoperative chemotherapy (n = 153; 72.2%). Chemotherapy consisted of fluoropyrimidine-based regimens: 5-FU monotherapy, 31.6%; irinotecan, 25.9%; and oxaliplatin, 14.6%. Among those patients who received chemotherapy, the type of chemotherapy regimen predicted distinct patterns of liver injury. Oxaliplatin was associated with increased likelihood of grade 3 sinusoidal dilatation (p = 0.017). Steatosis >30% was associated with irinotecan (27.3%) compared with no chemotherapy, 5-FU monotherapy, and oxaliplatin (all p < 0.05). Irinotecan also was associated with steatohepatitis, as two of the three patients with steatohepatitis had received irinotecan preoperatively. Overall, the perioperative complication rate was similar between the no-chemotherapy group (30.5%) and the chemotherapy group (35.3%) (p = 0.79). Preoperative chemotherapy was also not associated with 60-day mortality. In patients with hepatic colorectal metastases, preoperative chemotherapy is associated with hepatic injury in about 20 to 30% of patients. Furthermore, the type of hepatic injury after preoperative chemotherapy was regimen-specific. Presented at the American Hepato-Pancreato-Biliary Association 2006 Annual Meeting, March 11, Miami, Florida.  相似文献   
99.
目的 探讨维生素D受体(VDR)基因多态性与汉族人群慢性牙周炎(CP)易感性的关系。方法 收集汉族轻、中、重度CP患者共166例及80名无牙周炎对照者的颊黏膜拭子,以Chelex-100法提取DNA,采用聚合酶链反应-限制性片段长度多态性(PCR-RFLP)方法测定VDR BsmI、VDR ApaI和VDR TaqI的基因型,分析组间基因型分布和等位基因频率的差异。结果 轻、中、重度CP患者中VDR ApaI等位基因A携带者明显多于对照组,重度CP与中度CP、重度CP与轻度CP患者间VDR ApaI基因型的分布差异均有统计学意义,中度CP与轻度CP患者间VDR ApaI基因型分布差异无统计学意义,而VDR BsmI、TaqI位点的基因型分布在患者组和对照组间差异无统计学意义。结论 VDR ApaI等位基因A可能与汉族人群CP的易感性有关。  相似文献   
100.
The objective of this systematic review was to evaluate the impact of pharmacist delivered community-based services to optimise the use of medications for mental illness. Twenty-two controlled (randomised and non-randomised) studies of pharmacists' interventions in community and residential aged care settings identified in international scientific literature were included for review. Papers were assessed for study design, service recipient, country of origin, intervention type, number of participating pharmacists, methodological quality and outcome measurement. Three studies showed that pharmacists' medication counselling and treatment monitoring can improve adherence to antidepressant medications among those commencing treatment when calculated using an intention-to-treat analysis. Four trials demonstrated that pharmacist conducted medication reviews may reduce the number of potentially inappropriate medications prescribed to those at high risk of medication misadventure. The results of this review provide some evidence that pharmacists can contribute to optimising the use of medications for mental illness in the community setting. However, more well designed studies are needed to assess the impact of pharmacists as members of community mental health teams and as providers of comprehensive medicines information to people with schizophrenia and bipolar disorder  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