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   930篇
  免费   87篇
  国内免费   32篇
耳鼻咽喉   35篇
儿科学   7篇
妇产科学   5篇
基础医学   267篇
口腔科学   22篇
临床医学   48篇
内科学   205篇
皮肤病学   43篇
神经病学   7篇
特种医学   5篇
外科学   33篇
综合类   105篇
预防医学   18篇
眼科学   31篇
药学   76篇
中国医学   25篇
肿瘤学   117篇
  2024年   1篇
  2023年   8篇
  2022年   21篇
  2021年   29篇
  2020年   29篇
  2019年   22篇
  2018年   26篇
  2017年   30篇
  2016年   31篇
  2015年   43篇
  2014年   51篇
  2013年   61篇
  2012年   47篇
  2011年   49篇
  2010年   37篇
  2009年   30篇
  2008年   43篇
  2007年   48篇
  2006年   43篇
  2005年   31篇
  2004年   40篇
  2003年   29篇
  2002年   30篇
  2001年   30篇
  2000年   32篇
  1999年   25篇
  1998年   21篇
  1997年   16篇
  1996年   24篇
  1995年   15篇
  1994年   15篇
  1993年   19篇
  1992年   17篇
  1991年   12篇
  1990年   6篇
  1989年   5篇
  1988年   8篇
  1987年   5篇
  1986年   4篇
  1985年   5篇
  1984年   2篇
  1983年   2篇
  1982年   2篇
  1981年   1篇
  1979年   1篇
  1978年   2篇
  1977年   1篇
排序方式: 共有1049条查询结果,搜索用时 15 毫秒
1.
2.
Clinicopathologlc and mucin histochemical characteristics of 90 cases of ovarian mucinous borderline tumors (MBT) of Intestinal (IMET) and müllerian types (MMBT) were studied to determine whether IMBT and MMBT constitute distinct tumor subtypes. The IMBT (77 cases, 78 lesions) contained goblet cells, absorptive cells and endocrine cells, which represented Intestinal differentiation. The average diameter of IMBT was 13.4 cm. Five patients (6.5%) had stage III disease wtth pseudomyxoma perltonel and one of them died from tumor. Approximately 50% of IMBT demonstrated gastrointestinal characteistics on mucin histochemistry. The MMBT (13 cases, 14 lesions) consisted of mumus columnar cells and eosinophilic cells, with no Intestinal differentiation. MMBT accounted for 15.2% of MBT. MMBT averaged 8.4 cm in diameter, and 29% were associated with endometriosls of the ipsilateral ovary. All patients with MMBT had stage I disease, and none suffered from pseudomyxoma peritonel. All patients whose follow-up data were available were alive and well, without evidence of tumor recurrence. The mucin histochemical findings in MMBT resembled those of noml endocervix. Results of the present study suggest that IMBT and MMBT have different characteristics and constitute distinct subtypes of MBT.  相似文献   
3.
KL-6, a circulating mucin-like glycoprotein, is a pulmonary adenocarcinoma-associated antigen and is also regarded as an indicator of disease activity of interstitial pneumonitis. KL-6 has extensive heterogeneous antigenic determinants and consists of multiple heterogeneous antigen molecules. We have searched for circulating KL-6-associated glycoproteins with superior diagnostic value to KL-6 as a tumor marker for pulmonary adenocarcinoma. A new murine monoclonal antibody EH-123 reacting with an asialosugar chain on KL-6 was established. A new KL-6-associated molecule detected by a bimonoclonal bideterminant sandwich assay using the EH-123 antibody as a catcher and horseradish peroxidase-labeled KL-6 as a tracer was designated as CAM 123-6. In 59% (22 of 37) of patients with pulmonary adenocarcinoma, serum levels of CAM 123-6 were abnormally elevated and the positive rate increased with the progression of clinical stage. Elevated levels were not detected in normal individuals or in patients with benign lung diseases, other histologic types of lung cancer, gastric cancer, colon cancer or breast cancer. CAM 123-6 was more specific to pulmonary adenocarcinoma than carcinoembryonic antigen (CEA), but the sensitivity of CAM 123-6 for pulmonary adenocarcinoma was similar to that of CEA. CAM 123-6 is a promising candidate as a serum tumor marker for pulmonary adenocarcinoma.  相似文献   
4.
检查30例关节炎患者的关节液,结果示类风湿性关节炎患者关节液中白细胞数为330~72600/mm~3,粒细胞为9~97%,结合关节液的其它物理性质,对类风湿关节炎的诊断有一定参考价值。并观察到类风湿关节炎患者血清中IgG、IgA、IgM和关节液中IgG高于其它类型关节炎。  相似文献   
5.
In this review article, we demonstrate the mucin expression profile in normal tissue, invasive ductal carcinoma (IDC), two subtypes of intraductal papillary–mucinous neoplasm (IPMN dark cell type and IPMN clear cell type), pancreatic intraepithelial neoplasia (PanIN), and mucinous cystic neoplasm (MCN) of the pancreas. In MUC1, there are various glycoforms, such as poorly glycosylated MUC1, sialylated MUC1, and fully glycosylated MUC1. IDCs showed high expression of all the glycoforms of MUC1. IPMNs dark cell type showed no expression or low expression of all the glycoforms of MUC1. IPMNs clear cell type showed low expression of poorly glycosylated MUC1, but expression of sialylated MUC1 and fully glycosylated MUC1. Expression of MUC2 was negative in IDCs, high in IPMNs dark cell type and low in IPMNs clear cell type. MUC5AC was highly expressed in IDCs, IPMNs dark cell type, and IPMNs clear cell type. MUC6 expression was higher in IPMNs clear cell type than in IDCs and IPMNs dark cell type. Our recent study demonstrated that high expression of MUC4 in IDCs is correlated with a poor outcome for patients. In PanINs, expression of both MUC5AC and MUC6 are an early event, whereas up-regulation of MUC1 is a late event. MCNs do not look as if they will show a specific mucin expression profile according to the literature review.  相似文献   
6.
A carbohydrate differentiation antigen (CDA-3C2) exhibits a highly specific and restricted pattern of expression during rat embryogenesis. In the periphery of the embryo, this antigen is associated transiently with the lateral ectoderm but is retained only in the olfactory and otic epithelium throughout morphogenesis. At the light microscopic level, CDA-3C2 immunoreactivity appears mostly along cell periphery and in the extracellular matrix. The aim of the present study was to determine the specific cellular and subcellular distribution of CDA-3C2 in vivo in order to identify potential sites of cellular and tissue function of the antigen during embryogenesis. There was a strikingly similar subcellular distribution of CDA-3C2 in the developing otic and olfactory systems, found mostly along cell membranes, microvillar projections and acellular secretions of the epithelium. Mature sensory components of the epithelia were not immunoreactive, whereas supportive cells and their secreted structures were densely stained. The highly coincident nature of CDA-3C2 in both sensory epithelia suggests that this carbohydrate epitope, and possibly its carrier macromolecule, participate in a morphogenetic function common to these two sensory epithelia. © Wiley-Liss, Inc.  相似文献   
7.
Differentiated gastric carcinoma (DGC) corresponds roughly to the intestinal type of gastric carcinoma described by Laurén. It has been suggested that DGCs arise from intestinalized gastric mucosa, but recent findings regarding their mucin expression do not support this hypothesis. To evaluate the histogenetic relationship between DGCs and intestinal metaplasia, lesions that are as small as possible should be examined. Twenty-five DGCs, ranging in their greatest dimension from 0.4 to 2.7 mm, were collected and divided into two groups by size. Group A consisted of 13 lesions less than 1.4 mm across, and group B of 12 lesions 1.4 mm or more. The presence of mucin and a brush border was assessed by immunostaining with antibodies against human gastric mucin, pyloric-gland-type mucin, Muc-2 glycoprotein, and CD10 antigen, and the lesions were classified as having the gastric phenotype (G-type), intestinal phenotype (I-type), mixed gastric and intestinal phenotype (M-type), or null phenotype (N-type). Thirteen (52%) of the 25 lesions were N-type, 5 (20%) lesions were G-type, 5 (20%) were I-type, and 2 (8%) were M-type. Group A had a larger proportion of N-type lesions than B (10/13, or 77%, vs. 3/12, or 25%; p = 0.027, chi-square test for proportions). Group B had a larger proportion of G-type lesions than A (5/12, or 42%, vs. 0/13, or 0%; p = 0.033). The phenotypes of the carcinomas and their surrounding mucosa were unrelated. Therefore, DGCs may arise from gastric mucosa affected by intestinal metaplasia or not, without having either the gastric or intestinal phenotype.  相似文献   
8.
应用粘液组化方法AB—PAS、HID—AB、OR—AB、PAT—KOH—PAS、PATB—KOH—PAS显示大肠上皮分泌粘液的类型。结果发现:大肠慢性炎、大肠克隆病及炎性息肉、增生性息肉、幼年性息肉分泌粘液类型与正常粘膜相似(P>0.05),而伴有异型增生的溃疡性结肠炎、管状腺瘤、绒毛状腺瘤、家族性息肉、腺瘤癌变、大肠癌及癌旁粘膜粘液分泌性质与量均有变化。在这些病变中氮乙酰化及含有邻位羟基的氧乙酰化粘液阳性率明显高于正常粘膜(P<0.05)。其检出阳性率与异型增生的程度有关。笔者认为应用粘液组化方法分析大肠癌前病变粘液性质对于判断粘膜上皮恶性倾向提供了有价值的手段。  相似文献   
9.
A simple viscometric method was used to quantify mucin-polymer bioadhesive bond strength. Viscosities of 15% (w/v) porcine gastric mucin dispersions in 0.1 N HC1 (pH 1) or 0.1 N acetate buffer (pH 5.5) were measured with a Brookfield viscometer in the absence (m) or presence (t) of selected neutral, anionic, and cationic polymers (0.1–2.5%, w/v). Viscosity components of bioadhesion (1%) were calculated from the equation, t = m + p + b, where p is the viscosity of corresponding pure polymer solution as measured by an Ostwald viscometer. The forces of bioadhesion (F) were calculated from the equation, F = b, where is the rate of shear/sec. b's and F's for polyelectrolytes, e.g., polyacrylic acid, cationic gelatin, and chitosan were always higher in acetate buffer than in HC1. Validity of the technique and the effect of ionic charge, polymer conformation, and rate of shear on b and F are discussed, as is a comparison of this method to other methods for evaluating bioadhesive materials.  相似文献   
10.
采用特异、敏感的RT-PCR技术,检测来自20例乳腺癌病人的108个HE染色阴性的腋窝淋巴结MUC1 mRNA的表达,结果MUC11 mRNA在108个HE染色阴性淋巴结中阳性检出率为66%。提示:这些淋巴结中存在肿瘤隐蔽淋巴结转移,这种转移可能是一个或数个肿瘤细胞的转移,以此来提高微转移诊断率,可指导术后治疗,延长患者生存期,结果表明:MUC11 mRNA的RT-PCR分析法可用于乳癌淋巴结微转  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