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   740篇
  免费   20篇
  国内免费   2篇
儿科学   117篇
妇产科学   1篇
基础医学   36篇
口腔科学   5篇
临床医学   82篇
内科学   178篇
皮肤病学   12篇
神经病学   60篇
外科学   127篇
综合类   4篇
预防医学   4篇
眼科学   2篇
药学   75篇
中国医学   5篇
肿瘤学   54篇
  2017年   4篇
  2016年   9篇
  2015年   14篇
  2014年   9篇
  2013年   14篇
  2012年   6篇
  2011年   3篇
  2010年   16篇
  2009年   20篇
  2008年   6篇
  2007年   28篇
  2006年   38篇
  2005年   19篇
  2004年   34篇
  2003年   25篇
  2002年   12篇
  2001年   10篇
  2000年   3篇
  1999年   32篇
  1998年   66篇
  1997年   45篇
  1996年   53篇
  1995年   43篇
  1994年   40篇
  1993年   37篇
  1992年   16篇
  1991年   15篇
  1990年   14篇
  1989年   7篇
  1988年   8篇
  1987年   10篇
  1986年   10篇
  1985年   9篇
  1984年   6篇
  1983年   5篇
  1982年   5篇
  1981年   13篇
  1980年   11篇
  1979年   14篇
  1978年   5篇
  1977年   2篇
  1976年   5篇
  1975年   2篇
  1973年   2篇
  1972年   4篇
  1971年   3篇
  1970年   2篇
  1967年   2篇
  1957年   3篇
  1954年   1篇
排序方式: 共有762条查询结果,搜索用时 15 毫秒
21.
Eight cultured cell lines were established from human smallcell lung cancers. Every cell line showed the morphologicaland biochemical characteristics of small cell cancer. Changesin cell characteristics were observed in many of these celllines when culture conditions were changed: "oat cell type"changed to "intermediate cell type" and vice versa when serum-freemedium was changed to serum-supplemented medium; a deficiencyof vitamin A in the medium caused a change to squamous cellsand vice versa; and a tumor promoter (teleocidin B) enhancedthe adherence of these cells to the surface of plastic culturedishes. These findings provide evidence that many small celllung cancer cell lines can change their morphology with changesin the environment of the cells.  相似文献   
22.
In 45 healthy Japanese volunteers, it was found that personsheterozygous for ALDH2 (ALDH2*1/ALDH2*2), and also either heterozygousor mutant homozygous for CYP2E1 (C2/C2 or C1/C2 can drink muchmore alcohol, even with (slight) flushing, than persons heterozygousfor ALDH2 (ALDH2*1/ALDH2*2) and normal homozygous for CYP2E1(C1/C1)  相似文献   
23.
Immunogenic properties of second generation human tissue plasminogenactivator (tPA) derivatives were examined in chimpanzee andmouse systems. Five species of modified tPAs (mtPAs) (designated2660, 2663, 2810, 8000, and 9200), recombinant native tPA orbovine serum albumin (BSA) as a positive control were subcutaneouslyinjected nine times at suitable intervals into chimpanzees,genetically the closest species to man. These animals were testedfor antigen(Ag)-specific antibodies to the corresponding proteinsby means of enzyme-linked immunosorbent assay and Western blotanalysis. Neither 9200, one of the five mtPAs tested, nor tPAwas immunogenic, although BSA and the other four mtPAs wereimmunogenic under these conditions. Thus, an antigenic determinant was not exposed by the modification on 9200 and thismodified tPA is expected not to be immunogenic in humans. Inthe mouse studies, mice were immunized with mtPAs. Serum sam-piesfrom these animals were tested for antibodies to the mtPAs whichdid not concomitantly recognize native tPA by immune ad sorptionof the antibodies to tPA. The amount of such antibodies alterthe elimination of native tPA-reactive antibodies was littleor none when the serum samples from 9200 and from the othermtPAs, except 8000, were tested. Taking into consideration theresults of the chimpanzee studies, it can be concluded thatAg-specific antibodies are dominantly produced to unchangedepitopes present in modified proteins in the mouse system, inwhich the native protein is immunogenic. These results suggestthat the chimpanzee model should be useful to predict immunogenicityof second generation recombinant proteins in man, while themouse system adopted by us, which determines the newly generatedepitopes of the modified proteins, is not sufficient.  相似文献   
24.
A case report is presented of a 15-year-old girl with reflex sympathetic dystrophy (RSD). She was referred to hospital because of left upper limb pain. Her left upper limb was cold, edematous and blue with a limited active range of movement. The serum concentration of noradrenaline was lower on the painful side than on the healthy side, and neurotropin, which has an antinociceptive effect to hyperalgesia, was clearly effective. Early diagnosis and management is essential in the treatment of RSD and administration of neurotropin is a useful and non-invasive treatment without severe adverse effects.  相似文献   
25.
26.
27.
28.
A sensitive sandwich enzyme-linked immunosorbent assay (ELISA) has been established to estimate serum thrombopoietin (TPO) concentrations in healthy volunteers and patients with haemopoietic disorders. The ELISA uses a mouse monoclonal antibody (Ab) as the capture Ab and a biotinylated rabbit polyclonal Ab as the detector. The ELISA was reproducible, highly sensitive and specific for human TPO. The coefficients of intra- and inter-assay variation were from 3.0% to 4.9% and from 5.9% to 6.1%, respectively. The quantitative limit of the ELISA was 0.09 fmol/ml in serum. The quantitative limit was lower than the normal level. The dose–response curves of serum samples from healthy volunteers and patients with haemopoietic disorders were parallel to the standard curves. The ELISA did not cross-react with a variety of blood components and cytokines to produce false-positive results.
The serum TPO concentrations from 29 normal males and 21 females were 0.79 ± 0.35 and 0.70 ± 0.26 fmol/ml, respectively. Serum TPO levels in patients with aplastic anaemia (AA), acute lymphocytic leukaemia (ALL) and essential thrombocythaemia (ET) were measured using the ELISA. The serum TPO levels in the patients with ET ( n  = 6, 2.80 ± 1.55 fmol/ml) were higher than the normal level. The patients with AA ( n  = 7, 18.53 ± 12.37 fmol/ml) and ALL ( n  = 5, 10.36 ± 5.57 fmol/ml) had significantly higher serum TPO levels than normal individuals. These results indicate that the ELISA specific to TPO should prove useful in measuring the TPO concentration in serum samples.  相似文献   
29.
In order to clarify the characteristics of infectious mononucleosis hepatitis (IMH) in Japan, 20 cases with IMH treated at Kamo Hospital during the past 6 years (Group I) were analysed in comparison with cases of acute viral hepatitis, especially type A. The test for heterophil antibody was positive in only two cases. During the same period 209 cases were treated for acute viral hepatitis (type A: 77 cases = Group A; type B: 61 cases; type non-A, non-B: 71 cases). In Group I the common clinical symptoms and signs were headache, sore throat and lymph node swelling; jaundice was not as common as in Group A. GOT and GPT activities increased moderately in the acute stage, but they were significantly lower than those in Group A. LDH, AP, GGT and LAP activities were disproportionately higher to GPT activity in Group I. Liver biopsy in the convalescent stage showed that lipofuscin deposition and sinusoidal mononuclear cell infiltration were more prominent in Group I, while sinusoidal neutrocyte infiltration and focal necrosis at periportal areas were more common in Group A. Differential diagnosis of the two diseases could be made using these clinical features and histological findings. However, immunological differentiation is required for specific diagnosis because some features such as fever, prolonged elevation of thymol turbidity test, atypical lymphocytes in peripheral blod and predilection for young people were observed in both groups. Furthermore, the present study indicated that IMH is no longer rare and most cases do not demonstrate heterophil antibody in Japan.  相似文献   
30.
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