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   377篇
  免费   52篇
  国内免费   33篇
耳鼻咽喉   6篇
儿科学   29篇
妇产科学   2篇
基础医学   49篇
口腔科学   14篇
临床医学   63篇
内科学   81篇
皮肤病学   1篇
神经病学   21篇
特种医学   56篇
外科学   27篇
综合类   22篇
预防医学   17篇
眼科学   9篇
药学   48篇
中国医学   1篇
肿瘤学   16篇
  2020年   3篇
  2019年   4篇
  2018年   4篇
  2017年   8篇
  2016年   4篇
  2015年   6篇
  2014年   14篇
  2013年   13篇
  2012年   9篇
  2011年   10篇
  2010年   13篇
  2009年   16篇
  2008年   15篇
  2007年   24篇
  2006年   12篇
  2005年   12篇
  2004年   6篇
  2003年   9篇
  2002年   7篇
  2001年   6篇
  2000年   3篇
  1999年   18篇
  1998年   14篇
  1997年   18篇
  1996年   18篇
  1995年   15篇
  1994年   19篇
  1993年   14篇
  1992年   13篇
  1991年   11篇
  1990年   5篇
  1989年   14篇
  1988年   10篇
  1987年   10篇
  1986年   7篇
  1985年   8篇
  1984年   3篇
  1983年   3篇
  1982年   3篇
  1981年   11篇
  1979年   4篇
  1977年   8篇
  1976年   3篇
  1975年   7篇
  1974年   4篇
  1973年   3篇
  1971年   3篇
  1970年   3篇
  1968年   2篇
  1967年   2篇
排序方式: 共有462条查询结果,搜索用时 24 毫秒
21.

Background  

Studies on the impact of the 'obesogenic' environment have often used non-theoretical approaches. In this journal's debate and in other papers authors have argued the necessity of formulating conceptual models for differentiating the causal role of environmental influences on behavior.  相似文献   
22.
Positron emission tomography/CT is an established imaging method in the diagnosis and staging of cancers. 18F‐fluoro‐2‐deoxy‐d ‐glucose (FDG) is the most commonly used radiotracer in positron emission tomography/CT. It is a tumour viability agent and usually its uptake within a lesion reflects the presence of a viable tumour tissue. However, false‐positive FDG uptake is known to occur in benign processes of either inflammatory or infectious aetiology. We describe FDG uptake at the site of laparoscopic scar that mimicked Sister Mary Joseph’s nodule in a patient with gastric adenocarcinoma. Here, the knowledge of the patient’s history and subtle imaging findings helped in accurate staging of the patient. In this case report, we emphasize the value of the knowledge of the patient history and awareness of different pitfalls of FDG to achieve a correct diagnosis on positron emission tomography/CT.  相似文献   
23.
Rademaker KJ, Groenendaal F, Jansen GH, Eken P, de Vries LS. Unilateral haemorrhagic parenchymal lesions in the preterm infant: shape, site and prognosis. Acta Pædiatr 1994;83:602–8. Stockholm. ISSN 0803–5253 In a prospective cranial ultrasound study of 544 infants with a gestational age of 32 weeks or less, 20 (3.6%) infants were diagnosed as having a unilateral parenchymal lesion (PL). Based on the shape of the PL and the evolution on ultrasound, the infants were divided into three groups: group I consisted of 11 infants, in whom the PL was triangular/fan-shaped and separate from the ventricle. The PL evolved into small cystic lesions; group II comprised 3 infants who had a PL with a similar shape, but partially communicating with the ventricle; group III consisted of 6 infants who had a globular-shaped lesion in communication with the ventricle. In groups II and III, the PL evolved into one porcncephalic cyst. The PL was considered to be due to venous infarction in all cases with intraventricular haemorrhage preceding the PL in 7 cases. Sixteen infants survived. A postmortem was performed in 2 of the 4 infants who died, confirming the diagnosis of venous infarction. Neurologicdl sequelae were present in only 2 cases in the first group, while all 6 survivors of the other two groups developed mild to severe hemiplegia. Long-term follow-up was not always available and 4 of the 18 survivors were still less than 18 months when last seen. In 9 of the 11 infants in group I, the PL was localized in the frontoparietal region, while in 8 of the 9 infants in group II or III, the PL was beyond the trigone in the occipital region. The outcome of the unilateral PL is not always unfavourable. It was evident that not only the shape of the lesion and whether or not there was communication with the lateral ventricle, but also the site of the lesion (whether or not it extended into the occipital periventricular white matter) appeared to be important with regard to neurodevelopmental outcome.  相似文献   
24.
25.
26.
27.
28.
29.
We describe a middle-aged Chinese systemic lupus erythematosus (SLE) patient developing steroid refractory and transfusion dependent red cell aplasia. Oral danazol 200 mg twice per day was started together with low-dose prednisolone therapy. There was no further recurrence of anemia 1 month after this combined therapy.  相似文献   
30.
BACKGROUND: Secretory immunoglobulin A (SIgA) is the principal immunologic defense of respiratory and other mucosal surfaces in the body. SIgA is relatively stable in mucosal secretions. However, cleavage of SIgA by bacterial proteases might render it immunologically inactive and thus contribute to the development of pneumonia as well as other infections. Bacterial species and infection sites might be important in the expression of bacterial protease activity and serve as the impetus to this study. METHODS: Bacterial isolates from respiratory and nonrespiratory sites were incubated with SIgA in vitro. SIgA degradation was determined by size exclusion ultrafiltration and gel electrophoresis. RESULTS: IgA protease activity was evident in gram-negative but not gram-positive respiratory isolates. Gram-negative isolates from nonrespiratory sources did not exhibit IgA protease activity. CONCLUSIONS: Expression of IgA protease activity might be important in the development and subsequent outcome of gram-negative pneumonia in the patient in the surgical intensive care unit.  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