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排序方式: 共有170条查询结果,搜索用时 62 毫秒
81.
Leme de Calais FL Soardi FC Petroli RJ Lusa AL de Paiva E Silva RB Maciel-Guerra AT Guerra-Júnior G de Mello MP 《International journal of molecular sciences》2011,12(12):9471-9480
The steroid 5α-reductase type II enzyme catalyzes the conversion of testosterone (T) to dihydrotestosterone (DHT), and its deficiency leads to undervirilization in 46,XY individuals, due to an impairment of this conversion in genital tissues. Molecular analysis in the steroid 5α-reductase type II gene (SRD5A2) was performed in two 46,XY female siblings. SRD5A2 gene sequencing revealed that the patients were homozygous for p.Gln126Arg missense mutation, which results from the CGA > CAA nucleotide substitution. The molecular result confirmed clinical diagnosis of 46,XY disorder of sex development (DSD) for the older sister and directed the investigation to other family members. Studies on SRD5A2 protein structure showed severe changes at NADPH binding region indicating that structural modeling analysis can be useful to evaluate the deleterious role of a mutation as causing 5α-reductase type II enzyme deficiency. 相似文献
82.
Letícia Fernandes de Oliveira Jefferson Luiz Gomes Correa Poliana Gaspar Tosato Soraia Vilela Borges José Guilherme L. F. Alves Bruno Elyezer Fonseca 《Drying Technology》2013,31(8):946-952
Sugarcane bagasse is becoming more and more commonly used in generating electrical energy, steam, and bioethanol. Drying is important in sugarcane and other types of biomass because it can be used to improve the calorific value and overall energetic use. In this work, sugarcane bagasse was treated by drying in a cyclonic dryer. The influence of the geometry of the device (the conical part of the cyclone) and process parameters (bagasse mass flow rate and temperature) were tested. The modification on the conical part was related to two different angles and with two different inferior outlets (B). Experimental design was carried out for each geometry. The independent variables were the drying agent temperature (35 to 275°C) and the bagasse mass flow rate (0.1 × 10?2 to 2.9 × 10?2 kg s?1). The air flow rate was kept constant at 7.5 × 10?2 kg s?1. The dependent variables were moisture reduction (MR) and average particle residence time (tres) in the cyclonic dryer. For both cyclonic geometries, it was observed that MR was directly proportional to the temperature and inversely proportional to the bagasse mass flow rate. tres was also inversely proportional to the bagasse mass flow rate. Decreasing B tended to increase tres and MR. 相似文献
83.
Evaluation of polymerization shrinkage in dental restorative experimental composites based: BisGMA/TEGDMA,filled with MMT 下载免费PDF全文
Luiza Mello de Paiva Campos Letícia Cidreira Boaro Henrique Perez Ferreira Letícia Karine Gomes dos Santos Tamiris Ribeiro dos Santos Duclerc Fernandes Parra 《应用聚合物科学杂志》2016,133(24)
This work concerns to the investigation of the polymerization shrinkage and mechanical properties in dental restoratives experimental composites filled with nano clay Montmorilonite (MMT) Cloisite® 10A nanoparticles, in glycidyl methacrylate resin, using experimental composites filled with silanized Aerosil OX‐50 Silica as a control group. Six formulations with BisGMA/TEGDMA based polymeric matrix (three added with MMT and three added with silanized silica as filler) containing 50, 60, and 70 wt % were investigated. Characterization of the experimental composites was established with the following analyses: Scanning Electron Microscope, (SEM); Thermo‐Mechanical Analysis, (TMA) for Shrinkage Polymerization; Differential Scanning Calorimetry Analysis (DSC); Knoop Micro Hardness analysis; X‐ray Diffraction (XRD); Degree of Conversion (DC); Elastic Modulus and Flexural Strength; Transmission Electron Microscopy (TEM). Statistical Analyses were realized using two‐way ANOVA (type and amount of filler) and Tukey's test. TMA results showed that composites filled with MMT nanoparticle present statistically lower polymerization shrinkage values and statistically high degree of conversion in all formulations tested, when compared to composites filled with silanized silica. XRD and TEM analyses showed evidences of the intercalation phenomenon in the MMT nanoparticles in relation to BisGMA/TEGDMA polymeric matrix. However, for Flexural Strength, groups filled with MMT nanoparticle showed statistically lower values in all concentration tested. At high filler concentration it was observed the appearance of tactoids and functionalization of MMT nanoparticle did not promote a strong interface adhesion between polymeric matrix and filler. In order to adjust the mechanical properties, it would be convenient to promote the concentration optimization of MMT nanoparticles. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43543. 相似文献
84.
Paula G Cocate Letícia G Pereira Jo?o CB Marins Paulo R Cecon Josefina Bressan Rita CG Alfenas 《Nutrition journal》2011,10(1):1
Background
The consumption of low glycemic index (LGI) foods before exercise results in slower and more stable glycemic increases. Besides maintaining an adequate supply of energy during exercise, this response may favor an increase in fat oxidation in the postprandial period before the exercise compared to high glycemic index (HGI) foods. The majority of the studies that evaluated the effect of foods differing in glycemic index on substrate oxidation during the postprandial period before the exercise are acute studies in which a single meal is consumed right before the exercise. The purpose of this study was to investigate the effect of consuming two daily HGI or LGI meals for five consecutive days on substrate oxidation before the exercise and in the concentrations of glucose, insulin and free fatty acids before and during a high intensity exercise. 相似文献85.
Reuse of sorbitol solution in pulsed vacuum osmotic dehydration of yacon (Smallanthus sonchifolius) 下载免费PDF全文
86.
进行了MTBE裂解制异丁烯催化剂的试生产和寿命试验。在国内首套异丁烯工业装置(醚解法)上的应用证明其性能优异,转化率 》90%,异丁烯选择性近100%,甲醉选择性 》98%,运行一年后温升仅7 ℃,仍处于初期反应温度阶段,稳定性良好。 相似文献
87.
Camila F. Nascimento Letícia N. Gama‐De‐Souza Vanessa M. Freitas Ruy G. Jaeger 《Microscopy research and technique》2010,73(2):99-108
Migration, invasion and protease activity are essential for tumor progression and metastasis. Metastatic cells rely on invadopodia to degrade and invade extracellular matrix (ECM). Invadopodia are membrane protrusions with enzymes required for ECM degradation. These protrusions contain cortactin and membrane type 1 matrix metalloproteinase (MT1‐MMP) superimposed to areas of digested matrix. Here we characterized invadopodia in a cell line (CAC2) derived from human adenoid cystic carcinoma. We carried out fluorescent‐substrate degradation assay to assess in situ protease activity of CAC2 cells. Digestion spots in fluorescent substrate appear as black areas in green background. Cells were cultured on Matrigel‐gelatin‐FITC and fixed after 1 h and 3 h. CAC2 cells were double labeled to actin and cortactin. Cells were also double stained to actin and MT1‐MMP. Samples were studied by laser scanning confocal microscopy. In all time points CAC2 cells showed actin, cortactin, and MT1‐MMP colocalized with digestion spots in fluorescent substrate. We searched for other proteases involved in invadopodia activity. We have previously demonstrated that MMP9 influences adenoid cystic carcinoma behavior. This prompted us to investigate role played by MMP9 on invadopodia formation. CAC2 cells had MMP9 silenced by siRNA. After 1 h in fluorescent substrate, cells with silenced MMP9 showed clear decrease in matrix digestion compared with controls. No differences were found in cells with silenced MMP9 grown for 3 h on fluorescent substrate. Our results showed that CAC2 cells exhibit functional invadopodia containing cortactin and MT1‐MMP. Furthermore, MMP9 would be required in the initial steps of invadopodia formation. Microsc. Res. Tech., 2010. © 2009 Wiley‐Liss, Inc. 相似文献
88.
The term CLA (conjugated linoleic acid) corresponds to a mixture of positional and geometric isomers of linoleic acid, of which two (9/c/, 11/t/ and 10/t/, 12/c/) have biological activity. This review covers aspects related to CLA (sources, synthesis, distribution in human tissues, physiological activity), as well as its relationship with cardiovascular diseases. Most studies attribute the beneficial effects associated to the consumption of CLA to the reduction of risk factors for the development of cardiovascular diseases, such as the reduction of plasmatic triacylglycerols and cholesterol. Other research demonstrates the reduction of atherosclerotic processes. However, many studies indicate that CLA does not present beneficial effects or may even present negative effects. Thus, although there are a great number of studies related to CLA, we consider it premature to make any recommendation for the ingestion of these compounds, apart from those naturally present in a healthy diet. 相似文献
89.
Rosal R Rodríguez A Perdigón-Melón JA Mezcua M Hernando MD Letón P García-Calvo E Agüera A Fernández-Alba AR 《Water research》2008,42(14):3719-3728
The ozonation of an effluent from the secondary clarifier of two Municipal Wastewater Treatment Plants was performed by using alkaline ozone and a combination of ozone and hydrogen peroxide. Alkaline ozonation achieved only a moderate degree of mineralization, essentially concentrated during the first few minutes; but the addition of hydrogen peroxide eventually led to a complete mineralization. The evolution of total organic carbon (TOC) as a measure of the extent of mineralization and the concentration of dissolved ozone were analyzed and linked in a kinetic model whose parameter represented the product of the exposure to hydroxyl radicals and the kinetic constant of indirect ozonation. This rate parameter yielded the highest values during the first part of O(3)/H(2)O(2) runs. The kinetic constant for the decomposition of ozone at the end of the run was also measured and computed for the non-oxidizable water matrix and yielded essentially the same values regardless of whether or not hydrogen peroxide was used. A group of 33 organic compounds, mainly pharmaceuticals and some relevant metabolites present in the wastewater effluents, were evaluated before and after the ozonation process using a liquid chromatography-hybrid triple-quadrupole linear ion trap system (LC-QqLIT-MS). The results demonstrate that the ozonation degrades these compounds with efficiencies of over 99% in most cases, even under low mineralization conditions in alkaline ozonation. 相似文献
90.
Márcia Antoniazi Michelin Letícia Montes Rosekeila Sim?es Nomelini Marco Aurélio Trovó Eddie Fernando Candido Murta 《International journal of molecular sciences》2015,16(3):5497-5509
Immunotherapy in cancer patients is a very promising treatment and the development of new protocols and the study of the mechanisms of regression is imperative. The objective of this study was to evaluate the production of cytokines in helper T (CD4+) lymphocytes during immunotherapy with pegylated IFN-α in patients with cervical intraepithelial neoplasia (CIN). We conducted a prospective study with 17 patients with CIN II-III using immunotherapy with pegylated IFN-α subcutaneouly weekly, and using flow cytometry we evaluated the peripheric CD4+ T lymphocytes. The results show that in the regression group the patients presented a significant increase in the amount of IFN-γ during the entire immunotherapy, compared with the group without a response. The amount of CD4+ T lymphocytes positive for IL-2, IL-4, IL-10 and TGF-β is significantly lower in patients with good clinical response. The results also demonstrate that patients with regression have a higher amount of intracellular TNF-α in CD4+ T lymphocytes before the start of treatment. Analyzing these data sets, it can be concluded that immunotherapy is a viable clinical treatment for patients with high-grade CIN and that the regression is dependent on the change in the immune response to a Th1 pattern. 相似文献