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   465篇
  免费   23篇
  国内免费   31篇
耳鼻咽喉   1篇
儿科学   45篇
妇产科学   2篇
基础医学   33篇
口腔科学   28篇
临床医学   77篇
内科学   74篇
皮肤病学   1篇
神经病学   25篇
特种医学   59篇
外科学   21篇
综合类   22篇
预防医学   18篇
眼科学   4篇
药学   53篇
中国医学   1篇
肿瘤学   55篇
  2022年   3篇
  2021年   4篇
  2019年   8篇
  2018年   6篇
  2017年   6篇
  2016年   2篇
  2015年   4篇
  2014年   12篇
  2013年   15篇
  2012年   19篇
  2011年   28篇
  2010年   10篇
  2009年   18篇
  2008年   21篇
  2007年   30篇
  2006年   17篇
  2005年   13篇
  2004年   11篇
  2003年   14篇
  2002年   8篇
  2001年   15篇
  2000年   12篇
  1999年   16篇
  1998年   12篇
  1997年   19篇
  1996年   15篇
  1995年   15篇
  1994年   21篇
  1993年   14篇
  1992年   11篇
  1991年   14篇
  1990年   5篇
  1989年   13篇
  1988年   6篇
  1987年   9篇
  1986年   11篇
  1985年   7篇
  1984年   4篇
  1983年   4篇
  1982年   3篇
  1981年   10篇
  1980年   3篇
  1979年   2篇
  1978年   2篇
  1977年   5篇
  1976年   3篇
  1975年   6篇
  1972年   5篇
  1971年   3篇
  1969年   1篇
排序方式: 共有519条查询结果,搜索用时 15 毫秒
1.
Neuroimaging in Pineal Tumors   总被引:4,自引:0,他引:4  
F Reis  MD  AV Faria  MD  PhD  VA Zanardi  MD  PhD  JR Menezes  MD  F Cendes  MD  PhD  LS Queiroz  MD  PhD 《Journal of neuroimaging》2006,16(1):52-58
BACKGROUND AND PURPOSE: The authors report radiological findings in 11 tumors in the pineal region, which were histologically diagnosed as germinomas, pineocytomas pineoblastomas, ependymomas, teratomas, and astrocytomas. METHODS: Computed tomography (CT) was performed in seven patients and magnetic resonance imaging (MRI) was performed in all patients. RESULTS: CT showed a solid or solid/cystic mass with variable contrast enhancement. MRI showed a heterogeneous mass, with hypointense signal on T1 and iso/hyperintense signal on T2-weighted images (WI) and gadolinium enhancement. Extension to adjacent structures occurred in five patients and spread through the cerebral spinal fluid (CSF) in two. CONCLUSIONS: Pineal region tumors have no pathognomonic imaging pattern. MRI and CT are complementary in diagnosis and are important to determine localization, extension, and meningeal spread.  相似文献   
2.
3.
4.
5.
6.
Regulation and targeting of antiapoptotic XIAP in acute myeloid leukemia.   总被引:18,自引:0,他引:18  
XIAP is a member of the inhibitors-of-apoptosis family of proteins, which inhibit caspases and block cell death, with prognostic importance in AML. Here we demonstrate that cytokines regulate the expression of XIAP in leukemic cell lines and primary AML blasts. Inhibition of phosphatidylinositol-3 kinase (PI3K) with LY294002 and of the mitogen-activated protein kinase (MAPK) cascade by PD98059 resulted in decreased XIAP levels (34+/-8.7 and 23+/-5.7%, respectively). We then generated OCI-AML3 cells with constitutively phosphorylated Akt (p473-Akt) by retroviral gene transfer. Neither these nor Akt inhibitor-treated OCI-AML3 cells showed changes in XIAP levels, suggesting that XIAP expression is regulated by PI3K downstream effectors other than Akt. The induction of XIAP expression by cytokines through PI3K/MAPK pathways is consistent with its role in cell survival. Exposure of leukemic cells to chemotherapeutic agents decreased XIAP protein levels by caspase-dependent XIAP cleavage. Targeting XIAP by XIAP antisense oligonucleotide resulted in downregulation of XIAP, activation of caspases and cell death, and sensitized HL-60 cells to Ara-C. Our results suggest that XIAP is regulated by cytokines through PI3K, and to a lesser degree through MAPK pathways. Selective downregulation of XIAP expression might be of therapeutic benefit to leukemic patients.  相似文献   
7.
Eutectic mixture of local anesthetics (EMLA; Astra Pharmaceuticals, Wayne, PA) has been shown to reduce the pain of blood draws in children. We investigated the use of EMLA versus IV morphine for providing analgesia during chest tube removal (CTR) in children. One hundred twenty pediatric cardiothoracic surgery patients were enrolled. Patients were randomly assigned to receive either morphine (0.1 mg/kg up to 10 mg IV 30 min before CTR) or EMLA cream (5 g per chest tube cutaneously 3 h before CTR). A single, trained observer rated the patient's pain before, during, and after CTR using a 10-cm visual analog scale. The sites were evaluated for adverse effect. Methylhemoglobin levels were monitored in infants. Before CTR, the pain scores of the children who received morphine were rated lower than those who received EMLA (P < 0.01). During CTR, there was no difference in the pain score between the morphine or EMLA group. The change from baseline pain score in the morphine group was significantly larger than in the EMLA group (P < 0.01). We conclude that EMLA is safe and useful for blunting the pain of CTR.  相似文献   
8.
To express the core protein of HIV-1 of Chinese prevalent strain (HIV-1 (CN)) in Pichia pastoris, the fulllength gag gene was inserted into the secretory expression vector pHILS1. Linearized recombinant plasmid pHILGAG by Sail was electrotransformed into the yeast strain GS115, and the yeast transformants were identified by PCR. To induce the interest protein to be expressed, the PCR positive transformants were inoculated in the medium of BMGY and BMMY, mRNA of the strain was detected by RT-PCR, and the expressed protein was analyzed by SDS-PAGE, Western blotting and thin layer scanning. mRNA (1.3 kb) was amplified by RT-PCR. SDS-PAGE and Western blotting analysis showed that the molecular mass of the expressed protein was 55 kD, which was similar to the expected value, and the expressed protein could react with McAb to HIV-1 p24. Thin layer scanning analysis demonstrated that the whole amount of the expressed protein was approximately 13 % of the soluble protein in the supernatant. The recombinant yeast had good genetic stability. The optimal expression conditions of the engineering yeast were as follows: BMMY medium, 80-90% of dissolved oxygen, 1% methanol, and 3-day-cultivation course. Gag proteins were expressed under the optimal expression condition and purified via gel filtration chromatography. The purity of the interest protein was up to 85 %. After the purified proteins were inoculated into BALB/c mice, the anti-HIV-1 antibodies in the immunized mice could be detected by Western blotting.  相似文献   
9.
10.
Modern population based oral health management requires a complete understanding of the impact of disease in order to provide efficient and effective oral health care and guidance. Periodontitis is an important cause of tooth loss and has been shown to be associated with a number of systemic conditions. The impact of oral conditions and disorders on quality of life has been extensively studied. However, the impact of periodontitis on quality of life has received less attention. This review summarizes the literature on the impact of periodontitis on oral health‐related quality of life (OHRQoL). Relevant publications were identified after searching the MEDLINE and EMBASE electronic databases. Screening of titles and abstracts and data extraction was conducted. Only observational studies were included in this review. Most of the reviewed studies reported a negative impact of periodontitis on OHRQoL. However, the reporting standards varied across studies. Moreover, most of the studies were conducted in developed countries.  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