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   93篇
  免费   2篇
  2023年   1篇
  2022年   1篇
  2021年   3篇
  2020年   4篇
  2019年   3篇
  2018年   5篇
  2017年   1篇
  2016年   4篇
  2015年   2篇
  2013年   8篇
  2012年   4篇
  2011年   5篇
  2010年   5篇
  2009年   2篇
  2008年   4篇
  2007年   8篇
  2006年   1篇
  2005年   4篇
  2004年   3篇
  2003年   1篇
  2002年   2篇
  2001年   1篇
  1997年   1篇
  1995年   4篇
  1994年   1篇
  1993年   2篇
  1990年   1篇
  1989年   1篇
  1984年   2篇
  1982年   2篇
  1981年   1篇
  1979年   1篇
  1978年   2篇
  1977年   1篇
  1975年   2篇
  1970年   2篇
排序方式: 共有95条查询结果,搜索用时 31 毫秒
11.
Non-alcoholic fatty liver disease (NAFLD) is a condition defined by significant lipid accumulation (5–10%) in hepatic tissue in the absence of significant chronic alcohol consumption. We aim to detect frequency of fatty liver among overweight/obese adults and children and associated clinical; anthropological measures; biochemical; genetic and imaging studies. Eighty three consecutive adults and 72 children included in the study. All patients underwent clinical measurements of height, body weight, body mass index (BMI), waist and hip circumference. Biochemical investigations were done to all subjects including liver function tests; lipid profile; fasting blood glucose; insulin resistance (IR); high sensitivity C reactive protein (hs-CRP); adiponectin and genotyping of adiponectin genes. Abdominal ultrasonography was done to search for fatty liver; to measure subcutaneous fat thickness (SFT) and visceral fat thickness (VFT). Fatty liver was detected in 47 (65.3%) children and in 52 (62.7%) adults. Correlation analysis in both groups revealed that enlarged liver was highly positively correlated to age; BMI, systolic blood pressure (SBP), diastolic blood pressure (DBP); waist circumference; hip circumference, subcutaneous fat thickness (SFT) and Visceral fat thickness (VFT), alanine aminotransferase (ALT), aspartate aminotransferase/alanine aminotransferase (AST/ALT). In addition in adults to fasting blood glucose, cholesterol, triglycerides (TG), low density lipoprotein (LDL), IR and hs-CRP. Homozygous T adiponectin genotype at position +276 was significantly increased among children with enlarged liver size and hs-CRP. NAFLD affects a substantial portion of adults and children; it is associated with the metabolic syndrome.  相似文献   
12.
13.

Background

Sampling the microenvironment at sites of microbial exposure by dendritic cells (DC) and their subsequent interaction with T cells in the paracortical area of lymph nodes are key events for initiating immune responses. Most of our knowledge of such events in human is based on in vitro studies performed in the absence of extracellular matrix (ECM) proteins. ECM in basement membranes and interstitial spaces of different tissues, including lymphoid organs, plays an important role in controlling specific cellular functions such as migration, intracellular signalling and differentiation. The aim of this study was, therefore, to investigate the impact of two abundant ECM components, fibronectin and laminin, on the phenotypical and functional properties of DC and how that might influence DC induced T-cell differentiation.

Methodology/Principal Findings

Human monocyte derived DC were treated with laminin and fibronectin for up to 48 hours and their morphology and phenotype was analyzed using scanning electron microscopy, flow cytometry and real time PCR. The endocytic ability of DC was determined using flow cytometry. Furthermore, co-culture of DC and T cells were established and T cell proliferation and cytokine profile was measured using H3-thymidine incorporation and ELISA respectively. Finally, we assessed formation of DC-T cell conjugates using different cell trackers and flow cytometry. Our data show that in the presence of ECM, DC maintain a ‘more immature’ phenotype and express higher levels of key endocytic receptors, and as a result become significantly better endocytic cells, but still fully able to mature in response to stimulation as evidenced by their superior ability to induce antigen-specific T cell differentiation.

Conclusion

These studies underline the importance of including ECM components in in vitro studies investigating DC biology and DC-T cell interaction. Within the context of antigen specific DC induced T cell proliferation, inclusion of ECM proteins could lead to development of more sensitive assays.  相似文献   
14.
Dendritic cells are professional antigen-presenting cells that are specialized in antigen uptake and presentation. Allergy to cat has increased substantially in recent years and has been shown to be positively associated with asthma. We have recently shown that the mannose receptor (MR), a C-type lectin expressed by dendritic cells, recognizes various glycoallergens from diverse sources and is involved in promoting allergic responses to a major house dust mite allergen in vitro. Here we investigated the potential role of MR in allergic responses to Fel d 1, a major cat allergen. Fel d 1 binding to MR was confirmed by ELISA. Using blocking, gene silencing (siRNA) experiments, and MR knock-out (MR(-/-)) cells, we have demonstrated that MR plays a major role in internalization of Fel d 1 by human and mouse antigen-presenting cells. Intriguingly, unlike other glycoallergens, recognition of Fel d 1 by MR is mediated by the cysteine-rich domain, which correlates with the presence of sulfated carbohydrates in natural Fel d 1. WT and MR(-/-) mice were used to study the role of MR in allergic sensitization to Fel d 1 in vivo. MR(-/-) mice sensitized with cat dander extract and Fel d 1 produced significantly lower levels of total IgE, Fel d 1-specific-IgE and IgG1, the hallmarks of allergic response, compared with WT mice. Our data show for the first time that Fel d 1 is a novel ligand of the cysteine-rich domain of MR and that MR is likely to play a pivotal role in allergic sensitization to airborne allergens in vivo.  相似文献   
15.
BackgroundGiven the shortage of skilled healthcare providers in Nigeria, frontline community health extension workers (CHEWs) are commonly tasked with providing maternal and child health services at primary health centers. In 2012, we introduced a mobile case management and decision support application in twenty primary health centers in northern Nigeria, and conducted a pre-test/post-test study to assess whether the introduction of the app had an effect on the quality of antenatal care services provided by this lower-level cadre.MethodsUsing the CommCare mobile platform, the app dynamically guides CHEWs through antenatal care protocols and collects client data in real time. Thirteen health education audio clips are also embedded in the app for improving and standardizing client counseling. To detect changes in quality, we developed an evidence-based quality score consisting of 25 indicators, and conducted a total of 266 client exit interviews. We analyzed baseline and endline data to assess changes in the overall quality score as well as changes in the provision of key elements of antenatal care.ResultsOverall, the quality score increased from 13.3 at baseline to 17.2 at endline (p<0.0001), out of a total possible score of 25, with the most significant improvements related to health counseling, technical services provided, and quality of health education.ConclusionThese study results suggest that the introduction of a low-cost mobile case management and decision support application can spur behavior change and improve the quality of services provided by a lower level cadre of healthcare workers. Future research should employ a more rigorous experimental design to explore potential longer-term effects on client health outcomes.  相似文献   
16.
Dapsone (DPS) is a unique sulfone with antibiotic and anti-inflammatory activity. Owing to its dual action, DPS has a great potential to treat acne. Topical DPS application is expected to be effective in treatment of mild to moderate acne conditions. Invasomes are novel vesicles composed of phosphatidylcholine, ethanol, and one or mixture of terpenes of enhanced percutaneous permeation. In this study, DPS-loaded invasomes were prepared using the thin film hydration technique. The effect of different terpenes (Limonene, Cineole, Fenchone, and Citral) in different concentrations on the properties of the prepared DPS-loaded invasomes was investigated using a full factorial experimental design, namely, the particle size, drug entrapment, and release efficiency. The optimized formulation was selected for morphological evaluation which showed spherical shaped vesicles. Further solid-state characterization using differential scanning calorimetry and X-ray diffractometry revealed that the drug was dispersed in an amorphous state within the prepared invasomes. Finally, the ability of the prepared DPS-loaded invasomes to deliver DPS through the skin was investigated in vivo using wistar rats. The maximum in vivo skin deposition amount of DPS was found to be 4.11 mcg/cm2 for invasomes versus 1.71 mcg/cm2 for the drug alcoholic solution, representing about 2.5-fold higher for the invasomes compared to the drug solution. The AUC0–10 calculated for DPS-loaded invasomes was nearly 2-fold greater than that of DPS solution (14.54 and 8.01 mcg.h/cm2 for the optimized invasomes and DPS solution, respectively). These results reveal that the skin retention of DPS can be enhanced using invasomes.  相似文献   
17.

Purpose

To obtain protein hydrolysates from fresh water green algae Scenedesmus obliquus by three different enzymes and evaluate its antioxidant and antiviral activity.

Methods

Enzymatic hydrolysates of green algae Scenedesmus obliquus protein were prepared by treatment with: 1.2% solution of pepsin, trypsin or papain. Protein was extracted from S. obliquus by three different extraction methods. Protein extracts and hydrolysates were assessed from stained gels following SDS–PAGE of samples. Antioxidant activity of protein hydrolysates was investigated.

Results

S. obliquus cells and protein extracts were rich in Arg, Lys, Asp, Ala, and His. Protein hydrolyzed by papain (Sd1pa) and protein hydrolyzed by trypsin (Sd2Try) induced highest antioxidant activity based on 1,1-diphenyl-2-picryl-hydrazyl (DPPH) radical-scavenging (41.41% and 40.62%) respectively, and on 2,2′-azinobis 3-ethyl-benzothiazoline-6-sulphonate (ABTS) radical (87.03% and 45.12%) respectively, at 150?µg/ml. The inhibitory effect and mode of action of protein hydrolysates were evaluated against Coxsackie B3 virus (CVB3). Protein hydrolyzed by papain (Sd2pa) and protein hydrolyzed by pepsin (Sd1pep) at 100?µg/ml exhibited antiviral activity (66.2% and 57.6%, respectively), against (CVB3) from all protein hydrolysates.

Conclusion

S. obliquus protein hydrolysates have a potential as antioxidative neutraceutical ingredients and a potential therapeutic agent against CVB3.  相似文献   
18.
The present study was designed to find a complement fixation (CF) reaction for the diagnosis of type II lymphoid leukosis, to learn some of the characteristics of the CF antigen, and to investigate the development of CF antibody response to this infection. JM virus-specific antigen was demonstrated in tumorous chicken tissue, in JM virus-infected chick embryo material, in JM virus-infected chicken kidney, and in duck embryo fibroblast tissue culture by using JM virus-immune rabbit serum. This CF antigen did not show cross-reactivity with Rous sarcoma virus or with RIF-type viruses. It was partially heat-labile. The CF activity was restored at -70 C for 10 months and was resistant to intermittent freeze-thaw treatment. The CF antigen may be denatured by ethyl alcohol, but no significant deleterious effects were noted after ether or chloroform treatment. JM virus-specific CF antibody could not be demonstrated by the direct complement dilution method or by the indirect or inhibition form of the CF test in infected or immunized chicken sera.  相似文献   
19.
In the present work, we studied the chemical modification of Posidonia with maleic (AM) and phthalic (AP) anhydrides, and in the absence of any solvent. We used tripropylamine (TPA) as a catalyst and the mixture underwent an ultrasonic pretreatment. The influence of ultrasonic pretreating time, reaction time, temperature, anhydride concentration, was investigated. The extent of maleation and phthalation was measured by the percent of ester groups (TE), which increased when there was a parallel increment of anhydride concentration, reaction time, and temperature. Evidence of maleation and phthalation of the waste Posidonia biomass was provided by FT-IR and CP/MAS13C NMR. Thermogravimetric investigation of chemically modified Posidonia indicated a better thermal stability in comparison with the untreated Posidonia.  相似文献   
20.
Using a combination of High-Performance Ion Chromatography analysis and kinetic studies, the pathway of myo-inositol hexakisphosphate dephosphorylation by a phytase from a Malaysian waste-water bacterium was established. The data demonstrate that the phytase preferably dephosphorylates myo-inositol hexakisphosphate in a stereospecific way by sequential removal of phosphate groups via D-I(1,2,3,4,5)P5, D-I(2,3,4,5)P4, D-I(2,3,4)P3, D-I(2,3)P2 to finally I(2)P. It was estimated that more than 90% of phytate hydrolysis occurs via D-I(1,2,3,4,5)P5. Thus, the phytase from the Malaysian waste-water bacterium has to be considered a 6-phytase (E.C. 3.1.3.26). A second pathway of minor importance could be proposed which is in accordance with the results obtained from analysis of the dephosphorylation products formed by the action of the phytase under investigation on myo-inositol hexakisphosphate. It proceeds via D/L-I(1,2,4,5,6)P5, D/L-I(1,2,4,5)P4, D/L-I(1,2,4)P3, D/L-I(2,4)P2 to finally I(2)P.  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