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   215篇
  免费   14篇
  国内免费   5篇
耳鼻咽喉   10篇
儿科学   7篇
基础医学   38篇
口腔科学   1篇
临床医学   14篇
内科学   86篇
皮肤病学   1篇
神经病学   19篇
特种医学   5篇
外科学   14篇
综合类   1篇
预防医学   2篇
眼科学   1篇
药学   22篇
肿瘤学   13篇
  2023年   2篇
  2022年   2篇
  2021年   7篇
  2020年   7篇
  2019年   7篇
  2018年   8篇
  2017年   4篇
  2016年   7篇
  2015年   6篇
  2014年   8篇
  2013年   11篇
  2012年   7篇
  2011年   14篇
  2010年   5篇
  2009年   7篇
  2008年   7篇
  2007年   14篇
  2006年   14篇
  2005年   15篇
  2004年   13篇
  2003年   9篇
  2002年   15篇
  2001年   1篇
  2000年   3篇
  1999年   1篇
  1998年   2篇
  1997年   3篇
  1996年   4篇
  1995年   3篇
  1994年   2篇
  1993年   3篇
  1992年   5篇
  1991年   1篇
  1990年   1篇
  1988年   2篇
  1987年   1篇
  1986年   1篇
  1983年   1篇
  1982年   1篇
  1975年   1篇
  1972年   1篇
  1971年   1篇
  1968年   1篇
  1958年   2篇
  1957年   2篇
  1954年   2篇
排序方式: 共有234条查询结果,搜索用时 15 毫秒
1.
 

Aims:


The purpose of this study is to examine the relationship between immunohistochemical localization of cathepsin D (CD), proliferating cell nuclear antigen (PCNA) and epidermal growth factor receptor (EGF-R) in 65 cases of breast carcinoma in Japanese women and traditional prognostic factors such as histological grade, lymph node status, mitotic rate and clinical stage, in order to possibly identify some indicator(s) that may be specifically associated with prognosis.  

Methods and results:


Serial sections of 5-μm thick were cut from the archival formalin-fixed, paraffin-embedded tissue blocks, and processed for CD, PCNA and EGF-R immunostaining. The results were analysed by computer-based image analysis system. All samples showed a positive immunoreaction for cathepsin D in both the parenchyma and stroma. However, the staining area and intensity varied from cell to cell in the parenchyma and stroma as well as among samples. Subsequently, the evaluation of immunostaining for CD was separately performed in both the parenchyma and stroma (CDpar and CDstr, respectively) and the combination of both components (CDtotal). PCNA and EGF-R showed positive immunostaining almost exclusively in the parenchymal component of the carcinoma tissue specimens. CDtotal significantly correlated with the histological grade, PCNA index (PI), mitotic rate (MR), EGF-R and lymph node metastasis. Significant correlation was also demonstrated between CDpar and the histological grade, EGF-R and lymph node metastasis, or between CDstr and MR, EGF-R and lymph node metastasis. EGF-R correlated highly with the histological grade, MR score, lymph node metastases and recurrence-free survival.  

Conclusions:


Both the CD parameters and EGF-R are valuable indicators for predicting the biological behaviour of human breast carcinoma.  相似文献   
2.
AIMS: Galectin-3, a member of the beta-galactoside binding family of lectins, has been regarded as a useful tool for discriminating malignant tumours from benign nodules of the thyroid, including the distinction between follicular carcinoma and adenoma. However, there are follicular tumours with unclear vascular or capsular invasion, which makes diagnosis more difficult. In this study, we investigated the relationship between galectin-3 expression and the degree of vascular or capsular invasion of follicular tumours. METHODS: We immunohistochemically investigated galectin-3 expression in 260 cases of follicular tumour with various degrees of vascular or capsular invasion classified into four categories. RESULTS: The galectin-3 expression level significantly increased with the degree of vascular or capsular invasion (p<0.0001). However, its diagnostic value for follicular carcinoma was not high because the sensitivity and specificity were 68.7% and 57.5%, respectively. CONCLUSIONS: Our findings suggest that galectin-3 plays a role in the transformation of follicular tumours from benign to malignant; however, when diagnosing follicular tumours, the presence of this protein should not be required for diagnosing malignant transformation in all cases. Therefore, we must conclude that galectin-3 should only be considered an adjuvant marker for follicular carcinoma.  相似文献   
3.
4.
The nucleotide sequence of chicken Mx cDNA was reported earlier using the White Leghorn breed in Germany, but it showed no enhanced resistance to viruses. In this study, the nucleotide sequences of chicken Mx cDNA were determined in many breeds. A total of 25 nucleotide substitutions, of which 14 were deduced to cause amino acid exchanges, were detected, suggesting that the chicken Mx gene is very polymorphic. Transfected cell clones expressing chicken Mx mRNA were established after the Mx cDNA was constructed with an expression vector and introduced into mouse 3T3 cells, and the Mx genes from some breeds were demonstrated to confer positive antiviral responses to influenza virus and vesicular stomatitis virus. On the basis of the comparison among the antiviral activities associated with many Mx variations, a specific amino acid substitution at position 631 (Ser to Asn) was considered to determine the antivirally positive or negative Mx gene. Thus, a single amino acid substitution influences the antiviral activity of Mx in domesticated chickens.  相似文献   
5.
Autotaxin (ATX), or nucleotide pyrophosphatase‐phosphodiesterase 2, is a secreted lysophospholipase D that generates bioactive phospholipids that act on G protein–coupled receptors. Here we show the expression patterns of the ATX gene in mouse and chicken embryos. ATX has a dynamic spatial and temporal expression pattern in both species and the expression domains during neural development are quite distinct from each other. Murine ATX (mATX) is expressed immediately rostral to the midbrain‐hindbrain boundary, whereas chicken ATX (cATX) is expressed in the diencephalon and later in the parencephalon‐synencephalon boundary. In the neural tube, cATX is expressed in the alar plate in contrast to mATX in the floor plate. ATX is also expressed in the hindbrain and various organ primordia such as face anlagen and skin appendages of the mouse and chicken. These results suggest conserved and non‐conserved roles for ATX during neural development and organogenesis in these species. Developmental Dynamics 236:1134–1143, 2007. © 2007 Wiley‐Liss, Inc.  相似文献   
6.
Rat ascites hepatoma AH7974 cells strongly expressed antilaminin antibody-reactive substances (laminin-like substances) andGriffonia simplicifolia isolectin B4 (GS)-reactive carbohydrate (alpha)-d-galactose; alpha-Gal) on their cell surface. The alpha-Gal expression was not apparently influenced by the pretreatment of cells with methanol. The cell membrane laminin-like substances had approximate molecular weights of 150, 62 and 56 kDa in denaturating reducing conditions, of which the 62 and 56 kDa bands were stained with GS. The cell membrane molecules bearing alpha-Gal were 62 and 56 kDa and were stained with antilaminin antibody. Therefore, the major molecules bearing alpha-Gal residues of AH7974 cell membrane are considered to be laminin-like substances. To determine the role of the substances in metastasis, we selected four cell lines (74AD, 74AD-f, 74FL, 74FL-a) from AH7974 in culture. 74AD and 74FL-a are adherent lines and 74AD-f and 74FL are floating lines. All of these cell lines strongly expressed laminin-like substances, but a marked difference was found in expression of alpha-Gal, which was most strongly expressed by 74FL, followed by 74AD, and rarely by 74AD-f and 74FL-a; the staining intensity was positively correlated with their experimental lung-colonizing potential. Cell membrane laminin-like substances were 200, 97, 62, 56 and 46 kDa and among them 62 and 56 kDa molecules were glycosylated with alpha-Gal. The pretreatment of 74FL cells with antilaminin antibody or with human type A serum (containing natural antibody to alpha-Gal epitope) depressed remarkably the lung-colonizing potential of the cells. These results suggest that the expression of 62 and 56 kDa laminin-like substances with alpha-Gal residues on tumor cell surfaces is one of the determinants associated with lung-colonizing potential of these cells.  相似文献   
7.
A case of anglomyofibroblastoma of the vulva in a 49-year-old woman was examined. The tumor measured 3×2.5×2 cm and appeared light gray to tan In color on the cut surface. Light microscopic examinations revealed that spindle or oval shaped tumor cells were arranged in loose edematous stroma with numerous thin-walled vessels. Ultrastructurally, cell organellae were not well developed but intracytoplasmic filaments of intermediate size were abundant in the tumor cells. Desmin, CD34 and vimentin immunoreactivity were detected in almost all of the tumor cells. Both estrogen and progesterone receptors were diffusely expressed In the tumor, suggestive of the sex sterold-dependency of this tumor. The Ki-67 labeling index was less than 1% and the DNA content of the tumor cells, which was examined by image cytometry, demonstrated diploidy (DNA index=0.97). These findings may reflect the quiescent or slow growing features of angiomyofibroblastoma.  相似文献   
8.
Two autopsy cases of leiomyosarcoma of the liver in a 49-year old female and 63-year-old male are reported. Both of the liver tumors showed electron microscopically dense patches in the cytoplasm and intermediate junctions between the tumor cells, suggesting a smooth muscle cell origin, irrespective of their different histological features. The nature of both tumors was confirmed by positive immunoreactivity for muscle-specific actin in the tumor cells, whereas desmin immunoreactivity was labile in both cases, showing a higher diagnostic value of the former compared with the latter in these leiomyosarcomas. Both cases, showed extensive distant metastases in spite of an evident difference in their mitotic indices, indicating that this index is not reliable for judging the metastatic potential of these tumors. Acta Pathol Jpn 41: 461–465, 1991.  相似文献   
9.
10.
BACKGROUND/AIMS: Recently liver regeneration by bone marrow transplantation has been proposed as an alternative source of functional liver cells. We investigate commitment of bone marrow cells (BMCs) to liver regeneration and the effect of dalteparin sodium (DS) on regeneration of the damaged liver caused by carbon tetrachloride (CCl(4)) administration in the mice. METHODS: Liver injury was produced in 8-week-old mice by treating with CCl(4) for 4 weeks. Thereafter, mice received a lethal dose of irradiation (10Gy) to whole body, followed by injection of 1x10(7) green fluorescent protein (GFP)-positive BMCs via the tail vein. DS (50IU/kg, intraperitoneally) was administered daily for 28 consecutive days starting at 1 day post-BMC transplantation. Lineage marker analysis of GFP-positive liver cells was performed immunostaining with a CD31 antibody. RESULT: Four weeks after BMC transplantation, GFP-positive cells in the CCl(4)-damaged liver could be detected in the lobule displaying a meshwork architecture extending from the periportal to pericentral regions, a pattern simulating sinusoidal lining. This localization of GFP-positive cells suggested that these cells were closely associated with sinusoidal endothelial cells. By staining the GFP-positive cells for CD31, it was confirmed that the majority of the GFP-positive cells are also positive for CD31. The GFP(+)CD31(+) cells were barely detected in the control group (1.0+/-1.2 per field). In marked contrast, a numerous number of GFP(+)CD31(+) cells were detected in the liver section obtained from the CCl(4)-induced liver damage group (3.8+/-1.3 per field, P<0.05 versus control). The number of GFP(+)CD31(+) cells in CCl(4) plus DS-treated group was further increased to 8.3+/-1.3 per field (P<0.05 versus CCl(4)-induced liver damage group). CONCLUSION: The majority of GFP-positive BMCs was committed to sinusoidal endothelial cells. DS promoted BMC differentiation into sinusoidal endothelial cells in the CCl(4)-damaged liver.  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