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   673篇
  免费   52篇
  国内免费   2篇
耳鼻咽喉   1篇
儿科学   73篇
妇产科学   7篇
基础医学   83篇
口腔科学   11篇
临床医学   81篇
内科学   142篇
皮肤病学   21篇
神经病学   34篇
特种医学   99篇
外科学   78篇
综合类   10篇
预防医学   18篇
眼科学   1篇
药学   41篇
中国医学   1篇
肿瘤学   26篇
  2022年   7篇
  2021年   4篇
  2020年   3篇
  2019年   8篇
  2018年   13篇
  2017年   14篇
  2016年   13篇
  2015年   20篇
  2014年   13篇
  2013年   31篇
  2012年   15篇
  2011年   17篇
  2010年   32篇
  2009年   21篇
  2008年   16篇
  2007年   11篇
  2006年   15篇
  2005年   22篇
  2004年   14篇
  2003年   14篇
  2002年   18篇
  2001年   20篇
  2000年   13篇
  1999年   12篇
  1998年   22篇
  1997年   35篇
  1996年   27篇
  1995年   31篇
  1994年   23篇
  1993年   37篇
  1992年   7篇
  1991年   8篇
  1990年   16篇
  1989年   16篇
  1988年   17篇
  1987年   12篇
  1986年   13篇
  1985年   13篇
  1984年   3篇
  1983年   4篇
  1982年   6篇
  1981年   14篇
  1980年   6篇
  1978年   5篇
  1977年   8篇
  1976年   12篇
  1975年   4篇
  1965年   2篇
  1957年   2篇
  1954年   3篇
排序方式: 共有727条查询结果,搜索用时 15 毫秒
41.
The aim of our study was to investigate the immunotoxicity of benzene, styrene and polycyclic aromatic hydrocarbon exposure, to establish the correlation between immunological and genotoxicological parameters, and to assess the possible effect of confounding factors such as age and smoking. The immune status of the donors was characterized by measuring the surface antigens of peripheral lymphocytes. The studied antigens were the following: CD3, CD4, CD8, CD14, CD19, CD25, CD38, CD45, CD45RO, CD54, CD56, CD62L, CD71 and HLA-DR. In our studies, we compared the immunological and genotoxicological parameters (chromosome aberration, sister chromatid exchange frequency, unscheduled DNA synthesis) of the different groups with healthy controls. Analysis revealed changes in the expression of surface antigens on peripheral lymphocytes in correlation with exposure. Confounding factors, such as smoking, increased the proportion of CD4 positive T lymphocytes and influenced the surface expression of several antigens. In our investigation the occurrence of chromosome aberrations negatively correlated with CD25 (IL-2R) expression in both CD4 and CD8 positive T cells. The presented data suggest that solvents such as benzene, styrene and PAHs activate peripheral lymphocytes, and cause changes in the incidence of CD25+/CD4+ T lymphocytes that may represent a distinct subset of immune-regulatory T cells.  相似文献   
42.
43.
44.
In an infant with Menkes's steely-hair syndrome, early treatment (from 21 days of age) with parenteral copper failed to halt the disease. In addition to urinary tract abnormalities, panlobular emphysema was present a finding not previously noted in the syndrome.  相似文献   
45.
A history of pet contact and/or apparent clinical sensitivity was obtained in 65 (55%) of 118 unselected asthmatic children. These 65 children were skin tested and their sera examined for specific IgE using the radioallergosorbent test. Those children who had apparent clinical sensitivities had larger skin test reactions and were more likely to have positive specific IgE results than those without apparent sensitivities. Positive skin tests were very common (80%), but the larger the skin test reaction (weal diameter greater than 4 mm diameter) the more likely was there to be a positive history or a positive specific IgE result. Hence a large skin test reaction can provide a helpful pointer to animal allergy of clinical importance. Commercially available animal extracts have limitations for diagnostic tests. A questionnaire survey of 150 day schools emphasized the potential opportunities for contact with animal allergens at school.  相似文献   
46.
High-dose intravenous gammaglobulin (IVIgG) was given to 12 children and adults with chronic idiopathic thrombocytopenic purpura (ITP) to avoid splenectomy or because they either failed to respond to or required maintenance with high doses of steroids and/or immunosuppressives. The average platelet count increase to initial therapy was 239,500/microliters (range 23,000-790,000). A concomitant IgG Fc receptor blockade, measured by IgG-sensitized 51Cr-labeled autologous erythrocytes, was seen in 11 of 11 patients tested, both splenectomized and not splenectomized, lasting 3-4 wk. Six or more months after treatment, 2 children are in remission, 2 children and 2 adults are stable requiring no therapy with platelet counts of approximately 50,000 and 30,000, respectively, 3 children require maintenance IVIgG therapy at 2-10-wk intervals, and 1 child and 2 adults have become refractory to further IVIgG. Splenectomy was not performed in 4 children. Two adults were able to discontinue daily prednisone. The 3 patients who became unresponsive to Swiss Red Cross gamma-globulin (IgSRK) therapy did so in conjunction with a markedly elevated platelet-associated IgG and IgM. Serum IgM increased an average of 103 mg/dl after the IVIgG infusions. No significant side effects were seen.  相似文献   
47.
SUMMARY Serum potassium was measured within 24 hours in 156 patients (48 male, 108 female) with an average age of 81.9 years admitted to the unit with acute illness. Of the 156 patients, 88 (56.4%) were taking diuretics (none was on ACE inhibitors); 20 patients (12.8%) were also on digoxin therapy. In all, 24 patients (16%) had hypokalaemia and 3 (2%) hyperkalaemia. Hypokalaemia was seen in patients associated with acute illness. There was no significant difference between the diuretic and non-diuretic groups. Monitoring of serum potassium is not routinely indicated to detect hypokalaemia in patients on diuretic therapy except in those with severe hepatic or renal impairment or those on digoxin.  相似文献   
48.
49.
50.
Low-level echogenicity in intraventricular hemorrhage versus ventriculitis   总被引:1,自引:0,他引:1  
Grant  EG; White  EM; Schellinger  D; Rosenbach  D 《Radiology》1987,165(2):471-474
Serial cranial sonograms of 55 neonates with large perinatal intraventricular/intraparenchymal hemorrhages and moderate-to-severe posthemorrhagic hydrocephalus were reviewed. In all 55 patients, the ventricles were initially enlarged and filled with anechoic cerebrospinal fluid, which contained discrete hyperechoic fragments of hematoma. Between 7 and 25 days after the initial hemorrhagic episode, however, diffuse, low-level echogenicity appeared in the ventricles of 34 patients. The low-level echogenicity was transient and persisted for 7-59 days (average, 18 days). In 32 patients, low-level echogenicity was a benign finding associated with prior intraventricular hemorrhage. In two patients, the low-level echogenicity was associated with ventriculitis. Low-level echogenicity appeared, increased, then cleared, but reappeared with the onset of ventriculitis in these two patients. Thickening of the ependyma and abnormal periventricular echogenicity, signs of inflammation, were also present. Although low-level echogenicity may commonly be a benign finding, the possibility of ventriculitis should not be ignored.  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