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   1610篇
  免费   133篇
  国内免费   1篇
耳鼻咽喉   17篇
儿科学   54篇
妇产科学   33篇
基础医学   322篇
口腔科学   10篇
临床医学   146篇
内科学   328篇
皮肤病学   28篇
神经病学   60篇
特种医学   69篇
外科学   152篇
综合类   78篇
预防医学   147篇
眼科学   15篇
药学   159篇
中国医学   22篇
肿瘤学   104篇
  2023年   10篇
  2022年   26篇
  2021年   75篇
  2020年   45篇
  2019年   38篇
  2018年   50篇
  2017年   43篇
  2016年   31篇
  2015年   47篇
  2014年   68篇
  2013年   68篇
  2012年   111篇
  2011年   115篇
  2010年   58篇
  2009年   55篇
  2008年   73篇
  2007年   75篇
  2006年   63篇
  2005年   53篇
  2004年   60篇
  2003年   69篇
  2002年   61篇
  2001年   46篇
  2000年   49篇
  1999年   31篇
  1998年   16篇
  1997年   12篇
  1996年   11篇
  1995年   8篇
  1994年   13篇
  1993年   11篇
  1992年   20篇
  1991年   13篇
  1990年   21篇
  1989年   22篇
  1988年   17篇
  1987年   14篇
  1986年   11篇
  1985年   7篇
  1983年   5篇
  1981年   5篇
  1978年   4篇
  1976年   5篇
  1975年   7篇
  1974年   9篇
  1973年   8篇
  1972年   5篇
  1971年   6篇
  1970年   7篇
  1968年   5篇
排序方式: 共有1744条查询结果,搜索用时 15 毫秒
1.
S Dey  R H Singh 《Neuroreport》1992,3(6):497-500
Four week swim exercise schedule (45 min day-1, 6 days each week) in rats led to a significant adaptive change in functional responsiveness of dopamine receptors (auto-receptors) in the nigrostriatal and mesolimbic system that was evident from the modification of behavioural responses elicited by a low dose of apomorphine, a direct acting dopamine receptor agonist. Thus, a remarkable increase in yawning response, development of full blown stereotypy, as well as profound attenuation of locomotory and hypothermic response was observed in exercise-trained rats as compared with the non-exercise group (control), following intraperitoneal administration of 0.3 mg kg-1 of apomorphine.  相似文献   
2.
3.
4.
Infections are a common complication of allogeneic bone marrow transplantation and the leading cause of transplantation-related mortality. It had been hypothesized that transplantation following nonmyeloablative preparative regimens would result in fewer infections by causing less mucosal injury, less graft-versus-host disease, and allowing earlier immune reconstitution. We have retrospectively reviewed the infectious complications of 65 consecutive patients with advanced hematologic malignancies who underwent bone marrow transplantation using a novel preparative regimen consisting of cyclophosphamide, thymic irradiation, and in vivo T-cell depletion. Cytomegalovirus (CMV) infection occurred in 52% of cases in which the donor or recipient had evidence of prior CMV exposure. Using a strategy of preemptive therapy and secondary prophylaxis with ganciclovir, no CMV disease occurred. Infections with gram-positive bacteria predominated over the first 100 days after bone marrow transplantation. Thereafter, the relative proportion of gram-negative infections increased without a significant increase in episodes of neutropenia. The rate of bacterial infections was not influenced by relapse of the underlying malignancy. Seven patients developed infections with Aspergillus species, which was the most common infectious cause of death in these patients. Infections with viruses other than CMV (n=10) and with protozoan organisms (n=2) also occurred. The use of HLA-mismatched donors, the occurrence of grade II-IV acute graft-versus-host disease, and treatment with corticosteroids did not influence the risk of CMV or bacterial or fungal infections in patients who underwent transplantation following this preparative regimen. Overall, the incidence and spectrum of infections in this series was similar to the reported incidence of infections following conventional myeloablative allogeneic stem cell transplantation. We conclude that a quantitative T-cell deficiency in these extensively T-cell depleted patients may be a risk factor for infection, even in the absence of graft-versus-host disease.  相似文献   
5.
6.
The histopathologic features of malignant peripheral nerve sheath tumors (MPNSTs) have been well described. There have been limited studies on the cytologic features of MPNST. In this present study, we have retrospectively reviewed eight histopathology confirmed cases of MPNST over a 5-year period. Detailed cytomorphological analysis of these cases was carried out individually by two observers. On cytology, these cases were diagnosed as benign spindle-cell tumor (two), spindle-cell tumor possibly benign (one), spindle-cell tumor possibly malignant (one), malignant spindle-cell tumor (two), spindle-cell tumor, and neural origin (two). The cardinal cytomorphologic features were loosely cohesive clusters and fascicular arrangement of spindle cells with rounded ends. The kinking of nuclei was not a conspicuous finding. Fibrillary background was noted in two of the cases. Nuclear pleomorphism was ranged from mild to moderate degree. One case exhibited extensive intranuclear pseudoinclusions. Mitotic figures (including atypical forms) were present in almost all the cases. Possibly a constellation of cytologic features such as clusters of short and long fascicles of cells admixed with dissociated spindle cells of round-ended nuclei and prominent nucleoli on myxoid or fibrillary background and frequent mitosis may be helpful in diagnosis of MPNSTs. The cytomorphologic features along with clinical correlation are necessary to increase the diagnostic accuracy of MPNST on aspiration cytology.  相似文献   
7.
8.
A state-operated residential facility has for the past five years been using performance feedback as the primary method for improving direct care staff interactions with clients. The major problem with this approach is determining when staff performance is significantly above or below average. Statistical process control charts are being used to determine whether variations in staff performance are the result of common or special causes. Analysis of staff performance for one year suggests that variation in staff performance may be due to special causes, such as the characteristics of the clients served and the type of service that is provided to these clients. Services were adapted to the characteristics of these clients, which improved staff performance and reduced variation.  相似文献   
9.
10.
Vasculogenesis was simultaneously studied with embryogenesis in in ovo chick embryo culture, which was harvested at 40 hours. Endodermal cells and vascular endothelial cells were studied using a new combination of stains, immunohistochemistry (for nuclei and basement membrane) and NADPH-diaphorase activity in whole-mounts, paraffin sections and etched semithin sections. The model can be used for the study of developmental process of blood vessels as well as embryonic physiology of blood vessels vis-a-vis organogenesis in response to different angiogenic agents, drug trials, cancer therapy by angiostatic chemicals/radiations and toxins. Considering that vasculogenesis/angiogenesis as one of the fundamental phenomena in physiology, pathophysiology, toxicology and pharmacology of developmental sciences, the model in developing embryo is presented.  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