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   753篇
  免费   64篇
  国内免费   5篇
耳鼻咽喉   6篇
儿科学   27篇
妇产科学   33篇
基础医学   91篇
口腔科学   16篇
临床医学   90篇
内科学   226篇
皮肤病学   18篇
神经病学   28篇
特种医学   29篇
外科学   67篇
综合类   20篇
一般理论   1篇
预防医学   38篇
眼科学   32篇
药学   65篇
中国医学   1篇
肿瘤学   34篇
  2024年   2篇
  2023年   13篇
  2022年   47篇
  2021年   65篇
  2020年   43篇
  2019年   44篇
  2018年   49篇
  2017年   45篇
  2016年   38篇
  2015年   23篇
  2014年   35篇
  2013年   52篇
  2012年   56篇
  2011年   52篇
  2010年   28篇
  2009年   24篇
  2008年   23篇
  2007年   33篇
  2006年   19篇
  2005年   21篇
  2004年   9篇
  2003年   19篇
  2002年   8篇
  2001年   11篇
  2000年   10篇
  1999年   6篇
  1998年   3篇
  1997年   1篇
  1996年   2篇
  1995年   7篇
  1994年   2篇
  1993年   3篇
  1992年   9篇
  1991年   6篇
  1990年   6篇
  1989年   5篇
  1979年   1篇
  1976年   1篇
  1972年   1篇
排序方式: 共有822条查询结果,搜索用时 0 毫秒
21.
Colon cancer is a complex disease that involves numerous genetic alterations that change the normal colonic mucosa into invasive adenocarcinoma. In the current study, the protective effects of inulin (prebiotic), Lactobacillus casei (L. casei, probiotic) and their combination (synbiotic) on 1,2-dimethylhydrazine (DMH)-induced colon cancer in male Swiss mice were evaluated. Animals were divided into: Control group, DMH-treated group, DMH plus inulin, DMH plus L. casei and DMH plus inulin plus L. casei-treated groups. Fecal microbiome analysis, biochemical measurements, histopathological examination of the colon tissues, immunostaining and Western blotting analysis of β-catenin, GSK3β and JNK-1 were performed. The prebiotic-, probiotic- and synbiotic-treated groups showed decreased levels of carcinoembryonic antigen and a lower number of aberrant crypt foci compared to the DMH-treated group with the synbiotic group exhibiting a superior effect. Furthermore, all treatments showed a body weight-reducing effect. Administration of inulin, L. casei or their combination increased the expression level of phospho-JNK-1 while they decreased the expression level of β-catenin and phospho-GSK3β. Remarkably, L. casei treatment resulted in enrichment of certain beneficial bacterial genera i.e. Akkermansia and Turicibacter. Therefore, administration of L. casei and inulin as a synbiotic combination protects against colon cancer in mice.

The lactobacillus casei and inulin modulate the expression of JNK-1, GSK3β and β-catenin proteins and enrich the beneficial bacteria to protect from colon cancer in mice.  相似文献   
22.
Curcumin (CRM) is a natural polyphenol with antioxidative, anti-inflammatory, and anticancer therapeutic properties. However, CRM therapeutic potential is limited by low water solubility and bioavailability. Intraliposomal remote loading describes the retention of drugs in liposome cores in response to transmembrane pH gradient. The current study describes for the first time the remote loading of CRM into liposomes using secondary (E-βCD) and tertiary (D-βCD) amino-modified β-cyclodextrins (βCDs) as carriers and solubilizers. βCDs were chemically modified to prepare the ionizable weak base functional group followed by forming a guest-host complex of CRM in the modified βCDs hydrophobic cavities via a solvent evaporation encapsulation technique. These complexes were then actively loaded into preformed liposomes, composed of DPPC/cholesterol (65/35 molar ratio) via pH gradient. The formation of CRM-βCDs inclusion complexes was characterized using UV-Vis spectroscopy, thermal analysis, and NMR spectroscopy. The complex stoichiometric ratio was determined to be 1 : 1 of CRM-βCDs based on Job''s plot which was also confirmed by the modified Benesi–Hildebrand equation with increasing probability of forming the 1 : 2 ratio of CRM-βCDs. The apparent formation constants (Kf) of 51.6, 100.9 and 55.4 mM−2 were determined for CRM-βCD, CRM-E-βCD, and CRM-D-βCD complexes, respectively. Liposome size, charge and polydispersity index indicate the presence of a homogeneous population before and after active loading. The encapsulation efficiencies of CRM-βCD complexes into pH gradient preformed liposomes were 16.5, 51.1, and 41.7 for CRM-βCD, CRM-E-βCD, and CRM-D-βCD, respectively, showing more than 5 fold increase compared to normal liposomes. The current study provides a novel remote loading approach utilizing chemically modified cyclodextrins to incorporate hydrophobic drugs into liposomes.

The current study provides a novel remote loading approach utilizing chemically modified cyclodextrins to incorporate hydrophobic drugs into liposomes.  相似文献   
23.
24.
25.
Age changes affect the oral mucosa (the protective lining of the oral cavity), but few of these have been studied objectively. The aim of this study was to quantitatively analyse a number of morphometric parameters of the ageing oral mucosa. The fractal dimension of the epithelial connective tissue interface (ECTI) was estimated in 42 samples of normal buccal mucosa to correlate any changes in their irregularity to the age of the individuals. Morphometric parameters extracted from theoretical cell areas computed programatically were also analysed. Results showed no significant change in ECTI complexity associated with age; however, there was indication that epithelial cells tended to become larger and flatter with age. Interestingly, while some parameters did not show significant differences case wise, cluster analysis showed that the data clustered the cases into three main age groups: one representing the first two decades of life, another group represents adult life (21–50 years) and the last group representing the ageing population (50–90 years).  相似文献   
26.
To investigate the role of high-frequency ultrasonography in the diagnosis of calcium pyrophosphate dihydrate (CPPD) calcifications, in the most commonly affected joints in CPPD disease. Sixty patients with knee effusion were included in the study. All patients underwent musculoskeletal ultrasonography (on the shoulder, elbow, wrist, and knee joints), radiological examination of the sites examined by US, and synovial fluid analysis (using polarized light microscopy). Out of 60 patients with knee effusion, ultrasonographic calcifications (knees, shoulders, and wrists) were present in 38 patients (63.3%) and out of those patients; 32 had calcification characteristic of CPPD crystals deposition (hyperechoic deposits) in the knee and wrist joints. Pattern II (punctate pattern) was the most common pattern of calcification. It was present in all patients who had wrist calcification (18 patients) and in the knee in either alone (21 patients) or in association with pattern I (hyperechoic band) and/or pattern III (hyperechoic nodular or oval deposits) (9 patients). The sensitivity of ultrasonography for the detection of calcification was 84.2% while that of plain radiography was 13.2%, the specificity of both ultrasonography and plain radiography for the detection of calcification was 100%, and ultrasonography is valuable for diagnosing articular chondrocalcinosis via the detection of calcifications within the joint cartilage and fibrocartilage. Both sensitivity and specificity are high for detecting CPPD deposits.  相似文献   
27.
Phenotyping is commonly used for detection of extended-spectrum beta-lactamase (ESBL) production in gram-negative isolates. ESBLs are mainly coded for by four important genes, namely bla (TEM), bla (SHV), bla (CTX-M), and bla (OXA). Our aim in this study is to assess use of a multiplex PCR as a rapid method to identify four common genes responsible for ESBL production in different gram-negative isolates. All 793 clinical isolates are subjected to both screen and confirmatory testing for ESBL production using double disc synergy testing (DDST). Two hundred isolates with the ESBL phenotype are subjected to multiplex PCR for detection of the four genes bla (TEM, SHV, CTX-M, and OXA). The isolates were obtained from various clinical specimens: 68 (34 %) were isolated from urine cultures, 43 (21.5 %) from sputum, 26 (13 %) from wounds, 34 (17 %) from blood culture, 20 (10 %) from stool of healthy carrier and nine (4.5 %) from bronchoalveolar lavages. In this study, 83 isolates (41.5 %) were from outpatients (urine and stool specimens only), and the remaining 117 isolates (58.5) were from inpatients. By PCR technique, 181 isolates were found to be ESBL producers. blaTEM was the commonest genotype (39.2 %), followed by blaSHV (32.5 %) and blaCTX-M (30.9 %), either alone or in combination. Acinetobacter baumannii isolate had none of the ESBL genes. Eighteen (9.9 %) out of 181 isolates carried more than one type of beta-lactamase genes. Our study demonstrated rapid detection of bla (TEM, SHV, CTX-M, and OXA) in isolates belonging to Enterobacteriaceae and other nonfermenting clinical isolates using multiplex PCR. This genotypic method provided a rapid and efficient differentiation of ESBLs in the laboratory.  相似文献   
28.
29.
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