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   448篇
  免费   26篇
  国内免费   16篇
耳鼻咽喉   14篇
儿科学   24篇
妇产科学   7篇
基础医学   57篇
口腔科学   17篇
临床医学   41篇
内科学   87篇
皮肤病学   13篇
神经病学   8篇
特种医学   74篇
外科学   44篇
综合类   15篇
预防医学   21篇
眼科学   15篇
药学   25篇
中国医学   1篇
肿瘤学   27篇
  2022年   4篇
  2021年   4篇
  2019年   6篇
  2018年   10篇
  2017年   4篇
  2016年   10篇
  2015年   8篇
  2014年   17篇
  2013年   21篇
  2012年   8篇
  2011年   15篇
  2010年   34篇
  2009年   28篇
  2008年   5篇
  2007年   19篇
  2006年   12篇
  2005年   9篇
  2004年   8篇
  2003年   5篇
  2002年   9篇
  2001年   9篇
  2000年   14篇
  1999年   12篇
  1998年   37篇
  1997年   22篇
  1996年   18篇
  1995年   11篇
  1994年   14篇
  1993年   9篇
  1992年   2篇
  1991年   6篇
  1990年   5篇
  1989年   16篇
  1988年   9篇
  1987年   8篇
  1986年   5篇
  1985年   6篇
  1984年   4篇
  1983年   2篇
  1982年   6篇
  1981年   4篇
  1980年   9篇
  1978年   6篇
  1977年   4篇
  1975年   2篇
  1958年   2篇
  1957年   1篇
  1955年   1篇
  1954年   2篇
  1949年   2篇
排序方式: 共有490条查询结果,搜索用时 25 毫秒
441.
442.
Schumacher  TM; Genant  HK; Kellet  MJ; Mall  JC; Fye  KH 《Radiology》1978,126(2):289-297
The association between histo-compatibility antigens and disease is reviewed, in particular that between HLA-B27 and spondylitic disorders, i.e., ankylosing spondylitis, Reiter's arthritis, psoriatic arthritis, and ankylosing hyperostosis. We determined whether the presence of HLA-B27 predicted specific radiographic findings and, conversely, whether specific radiographic changes predicted antigenic status. The prevalences of the HLA-B27 antigen in our patients were: ankylosing spondylitis, 100%; Reiter's arthritis, 93%; psoriatic arthritis, 55%; and ankylosing hyperostosis, 12%. The only specific radiographic finding associated with B27 positivity was severe spondylitis in psoriasis.  相似文献   
443.
444.
445.
446.
It is more than a century since tympanic epithelial dispersion was first noted. This concept has not been analyzed mechanically until now. Serial photography of a circular disc holding 530 2.5 mm diameter ball-bearings, some of which were painted black to represent ink dots, has shown the centrifugal movement, enlargement and fragmentation of these marked areas when ball-bearings are added at random into the monolayer. Ink dots applied to mammalian drumheads move in a similar fashion. The model not only represented all the known tympanic epithelial phenomena faithfully, but could also be used to predict a mitotic index for the human drum. The index derived is consistent with normal human forearm skin if the dispersion of the corneocytes is due to the final shape change and insertion of lower epithelial cells into the lowest corneocyte layer.  相似文献   
447.
448.
BACKGROUND: A retrospective analysis was made to clarify the relationship between prognosis, radiation dose and survival of brain stem gliomas. METHODS: From 1983 to 1995, 22 children with brain stem tumors were treated by radiotherapy in the Veterans General Hospital-Taipei. Twelve patients had pathology proof and the remainder were diagnosed by computerized tomography and/or magnetic resonance imaging. Seven patients had postoperative radiotherapy. Fifteen patients had radiotherapy as primary management, five of whom had adjuvant chemotherapy. All patients received 4000-7060 cGy, either in conventional daily or hyperfractionated twice daily radiotherapy. Survival from date of diagnosis was calculated by the Kaplan-Meier method. Univariate analyses and multivariate analyses were calculated by the log rank test and the Cox proportional hazard model, respectively. RESULTS: Most patients showed improvement following treatment. The overall 2-year survival rate was 55.5% with a median survival of 27.1 months. Two-year survival for patients with primary management of operation and radiotherapy (n = 7), radiotherapy alone (n = 10) and radiotherapy with adjuvant chemotherapy (n = 5) were 66.7, 50 and 53.3%, respectively. In univariate analysis, the study revealed that the growth pattern of tumors and the simultaneous presence of cranial neuropathy and long tract sign were significant prognostic factors (P = 0.017 and 0.036). A trend of better outcome with radiation dose > 6600 cGy and the hyperfractionation scheme was also noted in our study (P = 0.0573 and 0.0615). However, only the hyperfractionation scheme was also noted in our study (P = 0.0573 and 0.0615). However, only the hyperfractionation scheme showed significance in multivariate analyses (P = 0.0355). Survival was not significantly affected by age, gender or method of diagnosis. CONCLUSION: Radiotherapy appears to be an effective treatment modality of brain stem tumors. Patients with both cranial neuropathy and long tract signs had a poorer outcome. Hyperfractionated radiotherapy may give better local control and lead to better survival.   相似文献   
449.
A randomized clinical trial was carried out to compare a locally available maize-cowpea-palm oil diet (group MCP) with a commercially produced lactose-free, soy protein isolate formula (group SF) for the dietary management of 69 Nigerian boys, 6–24 months of age, hospitalized for acute, watery diarrhea. Although the treatment groups were generally similar initially, the children in group SF had slightly lower mean weight-for-age z scores ( p = O.OS), lower serum bicarbonate levels ( p = 0.04) and greater stool outputs during the period of rehydration before the diets were initiated ( p = 0.01). Rates of treatment failure in group MCP (5.7%) and group SF (8.8%) were similar ( p = 0.67). There were no significant differences in the adjusted mean stool outputs by study group on days 1–5, but the children in group SF had slightly lower fecal weights on day 6 ( p = 0.05). Children in group MCP had a substantially reduced duration of liquid stool excretion (estimated median duration 42 h versus 140 h; p < 0.001). On the other hand, children in group SF consumed considerably more of their diet, had greater net absorption of macronutrients and greater rates of weight gain than those in group MCP. We conclude that children can safely consume the MCP diet during acute, watery diarrhea without increasing their risk of treatment failure or augmenting stool output. However, the diet may not be adequate as a sole source of nutrients beyond the period of acute illness.  相似文献   
450.
Spinocerebellar ataxia type1 (SCA1) is one of several neurodegenerative disorders caused by expansions of translated CAG trinucleotide repeats which code for polyglutamine in the respective proteins. Most hypotheses about the molecular defect in these disorders suggest a gain of function, which may involve interactions with other proteins via the expanded polyglutamine tract. In this study we used ataxin-1, the SCA1 gene product, as a bait in the yeast two-hybrid system and identified the glycolytic enzyme glyceraldehyde-3-phosphate dehydrogenase as an ataxin-1 interacting protein. In addition, the yeast two hybrid data demonstrate that wild type and mutant ataxin-1 form homo and heterodimers. Physical interaction between GAPDH and ataxin-1 was also demonstrated in vitro. To investigate if GAPDH might interact with other glutamine repeat-containing proteins involved in neurodegenerative disorders, we tested its binding to the androgen receptor which is mutated in spinobulbar muscular atrophy. The androgen receptor interacts with GAPDH both in the yeast two-hybrid system and in vitro. The binding of both ataxin-1 and the androgen receptor to GAPDH does not vary with the length of the polyglutamine tract. While provocative, these findings do not address the selective neuronal loss in each of these disorders in light of the wide expression patterns of GAPDH and the respective polyglutamine containing proteins. Nonetheless, such interactions may increase the susceptibility of specific neurons to a variety of insults and initiate degeneration.   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