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   571篇
  免费   46篇
  国内免费   1篇
耳鼻咽喉   8篇
儿科学   14篇
妇产科学   26篇
基础医学   127篇
口腔科学   17篇
临床医学   59篇
内科学   88篇
皮肤病学   6篇
神经病学   15篇
特种医学   12篇
外科学   91篇
综合类   4篇
预防医学   39篇
眼科学   24篇
药学   20篇
中国医学   2篇
肿瘤学   66篇
  2023年   4篇
  2021年   4篇
  2020年   7篇
  2019年   5篇
  2018年   6篇
  2017年   8篇
  2016年   7篇
  2015年   5篇
  2014年   12篇
  2013年   17篇
  2012年   26篇
  2011年   31篇
  2010年   17篇
  2009年   20篇
  2008年   26篇
  2007年   27篇
  2006年   23篇
  2005年   20篇
  2004年   25篇
  2003年   31篇
  2002年   22篇
  2001年   20篇
  2000年   18篇
  1999年   21篇
  1998年   13篇
  1997年   7篇
  1996年   9篇
  1995年   6篇
  1994年   8篇
  1993年   4篇
  1992年   12篇
  1991年   8篇
  1990年   8篇
  1989年   13篇
  1988年   8篇
  1986年   4篇
  1982年   5篇
  1978年   5篇
  1974年   5篇
  1972年   4篇
  1971年   9篇
  1970年   6篇
  1969年   11篇
  1968年   5篇
  1967年   6篇
  1966年   3篇
  1965年   3篇
  1962年   3篇
  1946年   5篇
  1925年   2篇
排序方式: 共有618条查询结果,搜索用时 31 毫秒
1.
Ohne ZusammenfassungMit 24 Textabbildungen.Vorgetragen: 1. I. Hausser, Ultraschall-Arbeitstagung Erlangen, 3. 5. 49; s. Kongreßbericht. 2. W. Doerr, ebendort; infolge Erkrankung vertreten durch I. Hausser. 3. R. Frey, Deutscher Chirurgenkongreß in Frankfurt, 9. 6. 49.  相似文献   
2.
3.
During the second half of the 19th century Donders, Snellen and co-workers of the Utrecht Eye Clinic played an important role in the development of clinical tonometry. These indefatigable researchers designed and built a number of tonometers of which most have been saved and which are now on display in a permanent exhibition in the Royal Netherlands Ophthalmic Hospital at Utrecht.  相似文献   
4.
Posttransplant lymphoproliferative disorders (PTLDs) represent a morphologic, immunophenotypic, and genotypic spectrum of disease. Most recently, Knowles et al divided PTLDs into 3 distinct categories: (1) plasmacytic hyperplasia, (2) polymorphic B-cell hyperplasia and polymorphic B-cell lymphoma, and (3) immunoblastic lymphoma and multiple myeloma. Although one form of PTLD may progress to another form, only 1 previous case has been reported in which multiple myeloma developed 14 months after an original diagnosis of plasmacytic hyperplasia. The type of solid organ transplant was not specified in that case. We report a post--cardiac transplant plasmacytic hyperplasia developing 7 years posttransplant. Six years subsequent to the plasmacytic hyperplasia, the patient developed a posttransplant plasmacytic malignancy, supported by morphology, flow cytometric immunophenotyping, and genotypic studies. Since we have no data to support disseminated bony disease or an abnormal serum protein, we have not used the term "multiple myeloma" for this case.  相似文献   
5.
BACKGROUND: Primary cutaneous T-cell-rich B-cell lymphoma is a relatively rare entity that has been diagnosed most commonly using immunohistochemical and molecular techniques. Flow cytometric immunophenotyping (FCI) has not been described in this entity. We report the demonstration of B-cell monoclonality by FCI in 3 cases of primary cutaneous T-cell-rich B-cell lymphoma. METHODS: Clinical and pathologic data were recorded for 3 cases of primary cutaneous T-cell-rich B-cell lymphoma. Immunohistochemical and FCI data were available in all cases; DNA analysis was performed in 1 case. RESULTS: Flow cytometric immunophenotyping revealed a monoclonal B-cell population exclusively in the monocyte (large cell) region in all 3 cases. Immunohistochemistry confirmed the T-cell richness of the infiltrates within the cutaneous lymphomas; T cells accounted for 65% to greater than 90% of the cells within the infiltrates. DNA analysis by polymerase chain reaction in 1 case did not demonstrate a monoclonal rearrangement of the immunoglobulin heavy-chain gene. CONCLUSIONS: Flow cytometric immunophenotyping in primary cutaneous T-cell-rich B-cell lymphoma may be useful in demonstrating monoclonality in these cases, especially if there is selective gating on the relatively small population of cells in the large cell region. The FCI data should be correlated with histology and immunohistochemistry.  相似文献   
6.
We analyzed the specific anti-Helicobacter pylori immunoglobulin G (IgG) antibody profile for a sample of 824 asymptomatic schoolchildren in southern Germany (mean age, 10.7 ± 0.65 years) with an H. pylori-specific IgG enzyme-linked immunosorbent assay and Western blot analysis. The prevalence of infection was 19.8% (95% confidence interval, 17.1 to 22.7%). The immunoresponses were characterized predominantly by antibodies against low-molecular-mass antigens of 14 and 29 kDa, with a significant difference between children of German and Turkish nationalities (P = 0.0012 and P < 0.0001, respectively).  相似文献   
7.
BACKGROUND: Angiogenesis is a critical factor in the development of malignant tumors, in arthritic joints, and in cardiovascular disease. In cardiovascular disease, angiogenesis is recognised both as a potential therapy and as a complicating factor in atherosclerotic plaque rupture and thrombotic obstruction. Serine proteases regulate thrombosis, inflammation, and cell invasion, events that trigger various stages of angiogenesis and are in turn regulated by inhibitors, termed serpins. Serp-1 is a secreted anti-inflammatory viral serpin that profoundly inhibits early mononuclear cell invasion, and the development of atherosclerosis, transplant vasculopathy, and arthritis in a range of animal models. METHODS: The capacity of Serp-1 to alter angiogenesis was evaluated in the chicken chorioallantoic membrane (CAM) model using morphometric analysis of vascular changes and RT-PCR to explore alterations in gene expression. RESULTS: Serp-1 inhibited endogenous angiogenesis in a dose-dependent manner, with associated altered expression of laminin and vascular endothelial growth factor (VEGF). Serp-1 was ineffective in CAMs no longer in the rapid growth phase. Similar inhibition of angiogenesis was detected after inhibition of VEGF, but not after treatment with the inactivated reactive center loop mutant of Serp-1. CONCLUSIONS: The angiogenic process can be controlled using Serp-1, an anti-inflammatory agent that is effective at low concentrations with rapid reversibility, targets endothelial cells, and reduces the availability of VEGF. These properties may be especially important in cardiovascular disease, reducing plaque destabilization. It is likely that the anti-angiogenic activity of Serp-1 contributes to the observed anti-inflammatory and anti-atherogenic actions with potential importance in this therapeutic setting.  相似文献   
8.
 CD56 and CD57 are commonly considered as natural killer and neuroectodermal markers, but their expression has been identified in a wide spectrum of neoplasms including some cases of Ewing’s sarcoma (ES) and primitive neuroectodermal tumor (PNET). We report two cases of small, round blue cell tumor (SRBCT), in which flow cytometry immunophenotyping (FCI) detected strong expression of CD56 and CD57 (one case). Immunohistochemical staining with Leu-19 and Leu-7 confirmed the FI results. Although CD56 and CD57 expression is consistent with ES/PNET, it can be potentially misleading if results of FCI are interpreted in the absence of other findings. These cases suggest the utility of FCI in undifferentiated SRBCT. The literature on CD56 and CD57 expression in ES/PNET is reviewed and discussed. Received: 5 January 1998 / Accepted: 19 February 1998  相似文献   
9.
Antigen-specific vaccines are one of several molecularly targeted approaches under investigation as possible treatments for prostate cancer. Important to the development of vaccines is the identification of appropriate target antigens. We hypothesized that antigens of the prostate might be identified in patients with the chronic prostatitis/pelvic pain syndrome, a syndrome for which an autoimmune pathology has been proposed. Such antigens might represent naturally recognized target antigens of the prostate that could be investigated in the future as prostate tumor antigens. In this report, we used SEREX to identify proteins expressed in a prostate cDNA expression library recognized by IgG from the sera of patients with chronic prostatitis. Candidate proteins were evaluated using a panel of sera from 62 subjects with symptomatic prostatitis and 71 control male blood donors. We identified one protein that was recognized primarily in sera from subjects with prostatitis compared with controls. MAD-PRO-34, a nucleolar autoantigen, was recognized in 6/62 subjects and 0/71 controls (p = 0.00897). This protein had previously been identified as an autoantigen in patients with prostate cancer. In addition, the NY-CO-7 protein was recognized in 9/62 subjects and 3/71 controls (p = 0.0654). Two subjects had IgG specific for both the MAD-PRO-34 and NY-CO-7 gene products. Our results demonstrate that some patients with the chronic prostatitis/pelvic pain syndrome have autoantibodies to specific proteins. Proteins identified, and MAD-PRO-34 in particular, could be further investigated as potential prostate tumor antigens.  相似文献   
10.
We present karyotypes of 15 meningiomas with structural aberrations of chromosome 7, which were taken from a consecutive series of 400 cytogenetically characterized meningiomas. Twelve of these tumors (80%) displayed partial or complete monosomy 7p with a consensus deleted region of 7p12 approximately pter, in 6 of 15 cases arising from an unbalanced whole-arm t(1;7)(q11;p11), and in 4 of 15 cases from a whole-arm translocation involving other chromosomes. Other types of partial aneusomy 7 (3/15 cases) or balanced aberrations of chromosome 7 (2/15 cases) were relatively rare. In most cases (11/15), the centromeric region of chromosome 7 was involved in the rearrangements. We conclude that in meningiomas, the near-centromeric region of chromosome 7 is particularly prone to structural rearrangements most frequently resulting in monosomy 7p. The investigation of the histopathologic features of this rare cytogenetic subgroup of meningiomas showed no clear genotype/phenotype correlation. As 7 of 11 of the meningiomas with monosomy 7p belonged to World Health Organization grades II or III, which usually comprise less than 20% of all meningiomas, partial loss of 7p appears to be involved in tumor progression in meningiomas. Because monosomy 7p is typically associated with the strongly progression-associated monosomy 1p, however, monosomy 7p represents a cofactor more than a stand-alone feature of meningioma progression.  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