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   391篇
  免费   32篇
  国内免费   13篇
儿科学   68篇
妇产科学   2篇
基础医学   35篇
口腔科学   5篇
临床医学   39篇
内科学   72篇
皮肤病学   7篇
神经病学   10篇
特种医学   91篇
外科学   42篇
综合类   10篇
预防医学   11篇
眼科学   1篇
药学   17篇
肿瘤学   26篇
  2022年   3篇
  2021年   7篇
  2016年   6篇
  2015年   6篇
  2014年   12篇
  2013年   9篇
  2012年   4篇
  2011年   7篇
  2010年   7篇
  2009年   10篇
  2008年   6篇
  2007年   15篇
  2006年   6篇
  2005年   8篇
  2004年   4篇
  2003年   9篇
  2002年   4篇
  2001年   3篇
  2000年   6篇
  1999年   16篇
  1998年   24篇
  1997年   22篇
  1996年   25篇
  1995年   25篇
  1994年   15篇
  1993年   12篇
  1992年   9篇
  1991年   4篇
  1990年   12篇
  1989年   15篇
  1988年   14篇
  1987年   11篇
  1986年   13篇
  1985年   11篇
  1984年   5篇
  1983年   6篇
  1982年   4篇
  1981年   2篇
  1980年   5篇
  1979年   7篇
  1978年   6篇
  1977年   5篇
  1976年   7篇
  1975年   2篇
  1974年   3篇
  1973年   3篇
  1972年   3篇
  1971年   5篇
  1970年   3篇
  1968年   2篇
排序方式: 共有436条查询结果,搜索用时 31 毫秒
61.
62.
63.
Hafenrichter  DG; Wu  X; Rettinger  SD; Kennedy  SC; Flye  MW; Ponder  KP 《Blood》1994,84(10):3394-3404
Hepatic gene therapy could be used to treat a number of inherited blood diseases such as hemophilia or thrombophilia. Although liver-directed retroviral transduction can result in long-term gene expression in vivo, the low level of protein production has limited its clinical application. We reasoned that the insertion of liver-specific promoters into retroviral vectors would increase gene expression in vivo. The 347- bp human alpha 1-antitrypsin (hAAT), the 810-bp murine albumin (mAIb), the 490-bp rat phosphoenolpyruvate carboxykinase (rPECK), and the 596- bp rat liver fatty acid binding protein promoters were inserted into a Moloney murine leukemia retroviral backbone containing the hAAT reporter gene. Vectors that produced appropriately sized RNA and hAAT protein in vitro were tested in vivo by transducing regenerating rat livers. Long-term serum expression of the hAAT reporter gene was normalized to retroviral transduction efficiency as determined by using a polymerase chain reaction-based assay of genomic DNA from transduced rat livers. The hAAT, mAIb, and rPEPCK promoters were, respectively, 35- , 8-, and 0.02-fold as strong as the previously studied constitutive Pol-II promoter. We conclude that the hAAT promoter resulted in the highest expression from a retroviral vector and may result in therapeutically significant expression of other clinically significant blood proteins.  相似文献   
64.
65.
Granulocyte colony-stimulating factor (G-CSF) is a candidate neuroprotective factor following cerebral ischemia. To determine whether G-CSF acts partly through the inhibition of nitric oxide synthase (NOS)-2 expression, we administered G-CSF to male NOS-2−/− mice after cerebral ischemia. Although male NOS-2−/− mice exhibit resistance to the gross effects of cerebral ischemia, they display neuronal loss and skilled motor deficits following cerebral ischemia. Administration of G-CSF during reperfusion reduced motor deficit and neuronal loss. Thus, G-CSF is still effective in NOS-2 gene-deficient mice, suggesting that part of the mechanism of action is independent of NOS-2.  相似文献   
66.

Background  

Dual antiplatelet therapy is usually superior to mono therapy in preventing recurrent vascular events (VEs). This systematic review assesses the safety and efficacy of triple antiplatelet therapy in comparison with dual therapy in reducing recurrent vascular events.  相似文献   
67.
The study investigates the correlation between oocyte maturity and fertilization and a variety of hormonal parameters in follicular fluid and ovarian granulosa cells. A methodology for purification of granulosa cells from contaminating blood cells is also established. A total of 63 follicular aspirates were collected at oocyte retrieval from 30 women superovulated using the long luteinizing hormone- releasing hormone (LHRH analogue)/human menopausal gonadotrophin regimen. Oestradiol, progesterone, testosterone and human chorionic gonadotrophin (HCG) were quantified in follicular fluid and granulosa cells were immunostained for human chorionic gonadotrophin. Immunopurification of granulosa cells from contaminating blood cells was performed. HCG in follicular fluid was significantly high in follicles yielding immature (grade 3) oocytes (P=0.002); there was no correlation with fertilization. Aspirates from follicles containing mature (grade 1) oocytes and oocytes that subsequently fertilized had significantly more granulosa cells immunobound to HCG (P < 0.001, P=0.02). Moreover, the immunomagnetic purification technique provided >98% pure population of granulosa cells. The data demonstrate that HCG in follicular fluid and on granulosa cells may help to predict oocyte maturity and fertilization. Furthermore, immunomagnetic beads provide a reliable procedure for the purification of ovarian granulosa cells.   相似文献   
68.
Plasmid DNA vectors have been constructed with minigenes encoding a single cytotoxic T lymphocyte (CTL) epitope from either the M2 protein of respiratory syncytial virus (RSV) or from the nucleoprotein of measles virus (MV) with or without a signal sequence (also called secretory or leader sequence). Following intradermal immunization, plasmids in which the CTL epitopes were expressed in-frame with the signal sequence were more effective at inducing peptide- and virus- specific CTL responses than plasmids expressing CTL epitopes without the signal sequence. This immunization resulted in protection against MV-induced encephalitis and a significant reduction in viral load following RSV challenge. The reduction of viral load following RSV challenge was abrogated by prior injection with anti-IFN-gamma antibodies. These results highlight the ability of epitope-based DNA immunization to induce protective immune responses to well-defined epitopes and indicate the potential of this approach for the development of vaccines against infectious diseases.   相似文献   
69.
阿片受体拮抗剂在TNF-α所致体温升高中的作用   总被引:1,自引:0,他引:1  
为探索细胞介素TNF-α升体温效应与下丘脑前部、视前区(POAH)中的阿片受体的关系。应用脑神经核团微量注射方法给自由状态下的雄性SD大鼠POAH区微量注射TNF-α致热源。给药前30min分别用通常阿片受体拮抗剂Nal(10~20μg)和特异性阿片受体μ、δ和κ的拮抗剂CTAP(1.0~2.5μg)、NTI(0.25~0.5μg)和nor-BNI(0.1~3μg)对POAH做预处理。结果:单独给TNF-α可致剂量相关的体温升高△T(1℃~1.4℃);经Nal10μg,CTAP1.0μg和NTI0.5μg处理后使TNF-α的升体温效应减弱;用Nal20μg,CTAP2.5μg和NTI0.25μg处理后可完全阻断TNF-α所致的体温升高;nor-BNI(0.1~3μg)对TNF-α的升体温效应无影响。  相似文献   
70.
Respond on comments on Lieberman's article: Cyclosiloxanes Produce Fatal Liver and Lung Damage in Mice. Environ Health Perspect 107:161-165  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