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   533篇
  免费   30篇
  563篇
  2022年   10篇
  2021年   16篇
  2020年   11篇
  2019年   3篇
  2018年   13篇
  2017年   11篇
  2016年   24篇
  2015年   32篇
  2014年   26篇
  2013年   37篇
  2012年   39篇
  2011年   45篇
  2010年   26篇
  2009年   26篇
  2008年   43篇
  2007年   29篇
  2006年   29篇
  2005年   25篇
  2004年   19篇
  2003年   19篇
  2002年   23篇
  2001年   2篇
  2000年   4篇
  1999年   6篇
  1998年   2篇
  1997年   3篇
  1995年   5篇
  1994年   2篇
  1993年   3篇
  1992年   7篇
  1991年   3篇
  1990年   3篇
  1989年   1篇
  1988年   1篇
  1987年   4篇
  1986年   1篇
  1984年   2篇
  1983年   1篇
  1982年   1篇
  1968年   4篇
  1967年   2篇
排序方式: 共有563条查询结果,搜索用时 15 毫秒
11.
12.
13.

Background

Male breast cancer is a rare event, accounting for approximately 1% of all breast carcinomas. Although men with breast cancer had poorer survival when compared with women, data on prognosis principally derive from retrospective studies and from extrapolation of female breast cancer series. We reported the case of a very long survival patient.

Case presentation

A caucasian 42-year-old man underwent radical mastectomy with axillary dissection for breast cancer in 1993. Pathologic stage was pT4pN0M0 infiltrating ductal carcinoma of right breast without lymph nodes metastases. Biological characterization was not available. He received adjuvant treatment with chemotherapy, six cycles of cyclophosphamide, methotrexate and fluorouracil, then endocrine therapy with tamoxifen for 5 years and complementary radiotherapy. Then he began clinical-instrumental follow up. In May 1996, a computed tomography scan showed multiple lung metastases. Hereafter he received several oncologic treatment including seven chemotherapy and five endocrine therapy lines with two re-challenge of endocrine therapy. In October 2007 further lung progression was showed and a biopsy was performed to characterize the disease. Histological examination confirmed breast cancer metastases, immunohistochemistry showed positive staining for estrogen receptor, negative for progesterone receptor and human epithelial growth factor receptor 2, proliferative index was 21%. In April 2013, bone disease progression was evident and he received radiant treatment to sacral spine. In May 2014 an off-label treatment with exemestane and everolimus combination was approved by Ethics Committee of the Marche Region. The patient received treatment for 3 months with evident clinical benefit to subcutaneous lesions of the chest wall that were not visible nor palpable on physical examination after 1 month of treatment.

Conclusion

That is the case of long survival male breast cancer patient with luminal B subtype and no BRCA mutations. He achieved higher progression free survival with endocrine therapy creating the rationale for last line treatment with everolimus and exemestane combination. Attending conclusive results from ongoing studies, everolimus and exemestane should not be used routinely in male metastatic breast cancer patients, but taking into account for selected cases. At the best of our knowledge, this is the first case of male beast cancer treated with exemestane and everolimus combination.
  相似文献   
14.
BackgroundMyocardial infarction is a public health problem. Functional food is an alternative treatment for cardiovascular diseases.ObjectiveThe objective was to analyze the functional and anatomopathological post-myocardial-infarction effects of soybean extract (SE) and isoflavone (IF).MethodsMyocardial infarction was induced in adult Wistar rats. After 5 days, an echocardiogram was performed to determine heart rate (HR), ejection fraction (EF), systolic volume (LVESV) and diastolic volume (LVEDV). Animals with ventricular dysfunction (EF<45%) were selected for study. The animals were divided into three groups: control (n=14), SE (n=15) and IF (n=12). The IF group received 120 mg/kg/day isolated IF, and the SE group received 12.52 g/day. After 30 days, a new echocardiogram was performed. A histological exam was carried out to determine the collagen. Activity of biochemical markers [arginase, lactate dehydrogenase (LDH) and malate dehydrogenase] was measured.ResultsThe animals of the control, IF and SE groups showed a reduction in EF after the infarction (P=.432, P=.017 and P=.320, respectively). An increase of LVESV and LVEDV was observed in all groups (P=.009, P=.001 and P=.140; and P=.003, P=.008 and P=.205, respectively). A reduction of HR was found in the SE group (P=.020). There was a greater activity of LDH in the SE group. A smaller quantity of mature collagen was found in the region proximal to the myocardial infarction in the SE group.ConclusionA protective effect in the SE group was observed 30 days after the myocardial infarction.  相似文献   
15.
16.
IMP preferring cytosolic 5 ′-nucleotidase II (cN-II) is a widespread enzyme whose amino acid sequence is highly conserved among vertebrates. Fluctuations of its activity have been reported in some pathological conditions and its mRNA levels have been proposed as a prognostic factor for poor outcome in patients with adult acute myeloid leukemia. As a member of the oxypurine cycle, cN-II is involved in the regulation of intracellular concentration of 5′-inosine monophosphate (IMP), 5′-guanosine monophosphate (GMP), and also 5-phosphoribose 1-pyrophosphate (PRPP) and is therefore involved in the regulation of purine and pyrimidine de novo and salvage synthesis. In addition, several studies demonstrated the involvement of cN-II in pro-drug metabolism. Notwithstanding some publications indicating that cN-II is essential for the survival of several cell types, its role in cell metabolism remains uncertain. To address this issue, we built two eucaryotic cellular models characterized by different cN-II expression levels: a constitutive cN-II knockdown in the astrocytoma cell line (ADF) by short hairpin RNA (shRNA) strategy and a cN-II expression in the diploid strain RS112 of Saccharomyces cerevisiae. Preliminary results suggest that cN-II is essential for cell viability, probably because it is directly involved in the regulation of nucleotide pools. These two experimental approaches could be very useful for the design of a personalized chemotherapy.  相似文献   
17.
Nucleoside monophosphate phosphohydrolases comprise a family of enzymes dephosphorylating nucleotides both in intracellular and extracellular compartments. Members of this family exhibit different sequence, location, substrate specificity and regulation. Besides the ectosolic 5′-nucleotidase, several cytosolic and one mitochondrial enzymes have been described. Nevertheless, researchers refer any AMP-dephosphorylating activity to as 5′-nucleotidase, lacking a more accurate identification. Increase of AMP hydrolysing activity has been associated with neurological and developmental disorders. The identification of the specific enzyme involved in these pathologies would be fundamental for the comprehension of the linkage between the enzyme activity alteration and brain functions. We demonstrate that the described neurological symptoms are associated with increased ectosolic 5′-nucleotidase activity on the basis of radiochemical assays and immunoblotting analysis. Furthermore, present data evidence that the assay conditions normally applied for the determination of cytosolic 5′-nucleotidases activity in crude extracts are affected by the presence of solubilised ectosolic nucleotidase.  相似文献   
18.
Fluorescent proteins, such as green fluorescent protein and red fluorescent protein (DsRED), have become frequently used reporters in plant biology. However, their potential to monitor dynamic gene regulation is limited by their high stability. The recently made DsRED-E5 variant overcame this problem. DsRED-E5 changes its emission spectrum over time from green to red in a concentration independent manner. Therefore, the green to red fluorescence ratio indicates the age of the protein and can be used as a fluorescent timer to monitor dynamics of gene expression. Here, we analyzed the potential of DsRED-E5 as reporter in plant cells. We showed that in cowpea (Vigna unguiculata) mesophyll protoplasts, DsRED-E5 changes its fluorescence in a way similar to animal cells. Moreover, the timing of this shift is suitable to study developmental processes in plants. To test whether DsRed-E5 can be used to monitor gene regulation in plant organs, we placed DsRED-E5 under the control of promoters that are either up- or down-regulated (MtACT4 and LeEXT1 promoters) or constitutively expressed (MtACT2 promoter) during root hair development in Medicago truncatula. Analysis of the fluorescence ratios clearly provided more accurate insight into the timing of promoter activity.  相似文献   
19.
The carcinogenic effect of asbestos has been reported in the literature since 40 years, and early studies describing the epidemic occurrence of malignant mesothelioma (MM) in asbestos workers, have become a paradigm of occupational cancer research. Research on MM was abandoned for many years since MM was considered as an asbestos-related disease, interesting only from a perspective of disease control and preventive policies. The introduction of new biological endpoints in the epidemiological studies has boosted research in the field, providing new tools for the study of emerging priority in cancer research and in public health. This approach, known as molecular epidemiology has a great potential in the study of MM, contributing to the understanding of susceptibility factors, to the evaluation of cancer risk in people occupationally or environmentally exposed to carcinogens, and to the enhancement of diagnosis and therapy. A comprehensive approach based on the use of banks of biological samples is presented and its advantages discussed here. The application of innovative endpoints, such as oncoproteins in biologic fluids, genetic polimorphisms, or gene function is discussed, and relevant literature reviewed.  相似文献   
20.
Three innovative and complementary morphological approaches were employed to study the T cell/antigen presenting cell (APC) interaction: (i) high resolution three-dimensional confocal microscopy of the T cell-APC contact site; (ii) time lapse video recording in living T cells of [Ca2+]I and changes in distribution of various GFP fusion proteins with TCR/CD3-zeta complex associated- and other signaling components; (iii) measurement of lateral TCR mobility and that of recruited signaling components using techniques based on fluorescence recovery after photo-bleaching. These approaches were combined with biochemical and functional experiments to investigate two principal issues: (A) Recruitment and the three-dimensional arrangement of receptors and signaling components at the contact site between human CD4+ T lymphocytes and APCs, (B) Structure of the immunological synapse formed at the contact site between cytotoxic T lymphocytes (CTLs) and target cells. We discuss evidence indicating that TCR engagement and triggering can occur in the absence of large-scale molecular segregation into the T cell-APC contact site. Taken together our results indicate that although not required for TCR engagement and triggering, formation of the IS is important to reinforce TCR-mediated signal transduction and achieve full T cell activation.  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