11 resultados para PROPORTIONS

em Repositório da Produção Científica e Intelectual da Unicamp


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This work addresses the development and characterization of porous chitosan-alginate based polyelectrolyte complexes, obtained by using two different proportions of the biocompatible surfactant Pluronic F68. These biomaterials are proposed for applications as biodegradable and biocompatible wound dressing and/or scaffolds. The results indicate that thickness, roughness, porosity and liquid uptake of the membranes increase with the amount of surfactant used, while their mechanical properties and stability in aqueous media decrease. Other important properties such as color and surface hydrophilicity (water contact angle) are not significantly altered or did not present a clear tendency of variation with the increase of the amount of surfactant added to the polyelectrolyte complexes, such as real density, average pore diameter, total pore volume and surface area. The prepared biomaterials were not cytotoxic to L929 cells. In conclusion, it is possible to tune the physicochemical properties of chitosan-alginate polyelectrolyte complexes, through the variation of the proportion of surfactant (Pluronic F68) added to the mixture, so as to enable the desired application of these biomaterials.

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The Fourier transform-infrared (FT-IR) signature of dry samples of DNA and DNA-polypeptide complexes, as studied by IR microspectroscopy using a diamond attenuated total reflection (ATR) objective, has revealed important discriminatory characteristics relative to the PO2(-) vibrational stretchings. However, DNA IR marks that provide information on the sample's richness in hydrogen bonds have not been resolved in the spectral profiles obtained with this objective. Here we investigated the performance of an all reflecting objective (ARO) for analysis of the FT-IR signal of hydrogen bonds in DNA samples differing in base richness types (salmon testis vs calf thymus). The results obtained using the ARO indicate prominent band peaks at the spectral region representative of the vibration of nitrogenous base hydrogen bonds and of NH and NH2 groups. The band areas at this spectral region differ in agreement with the DNA base richness type when using the ARO. A peak assigned to adenine was more evident in the AT-rich salmon DNA using either the ARO or the ATR objective. It is concluded that, for the discrimination of DNA IR hydrogen bond vibrations associated with varying base type proportions, the use of an ARO is recommended.

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Originally from Asia, Dovyalis hebecarpa is a dark purple/red exotic berry now also produced in Brazil. However, no reports were found in the literature about phenolic extraction or characterisation of this berry. In this study we evaluate the extraction optimisation of anthocyanins and total phenolics in D. hebecarpa berries aiming at the development of a simple and mild analytical technique. Multivariate analysis was used to optimise the extraction variables (ethanol:water:acetone solvent proportions, times, and acid concentrations) at different levels. Acetone/water (20/80 v/v) gave the highest anthocyanin extraction yield, but pure water and different proportions of acetone/water or acetone/ethanol/water (with >50% of water) were also effective. Neither acid concentration nor time had a significant effect on extraction efficiency allowing to fix the recommended parameters at the lowest values tested (0.35% formic acid v/v, and 17.6 min). Under optimised conditions, extraction efficiencies were increased by 31.5% and 11% for anthocyanin and total phenolics, respectively as compared to traditional methods that use more solvent and time. Thus, the optimised methodology increased yields being less hazardous and time consuming than traditional methods. Finally, freeze-dried D. hebecarpa showed high content of target phytochemicals (319 mg/100g and 1,421 mg/100g of total anthocyanin and total phenolic content, respectively).

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Here, we describe our experience with different therapeutic modalities used to treat cystic lymphangiomas in children in our hospital, including single therapy with OK-432, bleomycin and surgery, and a combination of the three modalities. We performed a retrospective, cross-sectional study including patients treated from 1998 to 2011. The effects on macrocystic lymphangiomas and adverse reactions were evaluated. Twenty-nine children with cystic lymphangiomas without any previous treatment were included. Under general anesthesia, patients given sclerosing agents underwent puncture of the lesion (guided by ultrasound when necessary) and complete aspiration of the intralesional liquid. The patients were evaluated with ultrasound and clinical examinations for a maximum follow-up time of 4 years. The proportions of patients considered cured after the first therapeutic approach were 44% in the surgery group, 29% in the bleomycin group and 31% in the OK-432 group. These proportions were not significantly different. Sequential treatment increased the rates of curative results to 71%, 74% and 44%, respectively, after the final treatment, which in our case was approximately 1.5 applications per patient. The results of this study indicate that most patients with cystic lymphangiomas do not show complete resolution after the initial therapy, regardless of whether the therapy is surgical or involves the use of sclerosing agents. To achieve complete resolution of the lesions, either multiple operations or a combination of surgery and sclerotherapy must be used and should be tailored to the characteristics of each patient.

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This study was aimed at spray drying hydrolysed casein using gum Arabic as the carrier agent, in order to decrease the bitter taste. Three formulations with differing proportions of hydrolysed casein: gum Arabic (10:90, 20:80 and 30:70) were prepared and characterized. They were evaluated for their moisture content, water activity, hygroscopicity, dispersibility in water and in oil, particle size and distribution, particle morphology, thermal behaviour (DSC) and bitter taste by a trained sensory panel using a paired-comparison test (free samples vs. spray dried samples). The proportion of hydrolysed casein did not affect the morphology of the microspheres. The spray drying process increased product stability and modified the dissolution time, but had no effect on the ability of the material to dissolve in either water or oil. The sensory tests showed that the spray drying process using gum Arabic as the carrier was efficient in attenuating or masking the bitter taste of the hydrolysed casein.

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Reports of long-term tenofovir disoproxil fumarate (TDF) treatment in HIV-infected adolescents are limited. We present final results from the open-label (OL) TDF extension following the randomized, placebo (PBO)-controlled, double-blind phase of GS-US-104-0321 (Study 321). HIV-infected 12- to 17-year-olds treated with TDF 300 mg or PBO with an optimized background regimen (OBR) for 24-48 weeks subsequently received OL TDF plus OBR in a single arm study extension. HIV-1 RNA and safety, including bone mineral density (BMD), was assessed in all TDF recipients. Eighty-one subjects received TDF (median duration 96 weeks). No subject died or discontinued OL TDF for safety/tolerability. At week 144, proportions with HIV-1 RNA <50 copies/mL were 30.4% (7 of 23 subjects with baseline HIV-1 RNA >1000 c/mL initially randomized to TDF), 41.7% (5 of 12 subjects with HIV-1 RNA <1000 c/mL who switched PBO to TDF) and 0% (0 of 2 subjects failed randomized PBO plus OBR with HIV-1 RNA >1000 c/mL and switched PBO to TDF). Viral resistance to TDF occurred in 1 subject. At week 144, median decrease in estimated glomerular filtration rate was 38.1 mL/min/1.73 m (n = 25). Increases in median spine (+12.70%, n = 26) and total body less head BMD (+4.32%, n = 26) and height-age adjusted Z-scores (n = 21; +0.457 for spine, +0.152 for total body less head) were observed at week 144. Five of 81 subjects (6%) had persistent >4% BMD decreases from baseline. Some subjects had virologic responses to TDF plus OBR, and TDF resistance was rare. TDF was well tolerated and can be considered for treatment of HIV-infected adolescents.

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This work was done with the objective of studying some physical and mechanical characteristics of the sugarcane bagasse ash added to a soil-cement mixture, in order to obtain an alternative construction material. The sugarcane bagasse ash pre-treatment included both sieving and grinding, before mixing with soil and cement. Different proportions of cement-ash were tested by determining its standard consistence and its compressive resistance at 7 and 28 days age. The various treatments were subsequently applied to the specimens molded with different soil-cement-ash mixtures which in turns were submitted to compaction, unconfined compression and water absorption laboratory tests. The results showed that it is possible to replace up to 20% of Portland cement by sugarcane bagasse ash without any damage to the mixture's compressive strength.

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Mental health problems are common in primary health care, particularly anxiety and depression. This study aims to estimate the prevalence of common mental disorders and their associations with socio-demographic characteristics in primary care in Brazil (Family Health Strategy). It involved a multicenter cross-sectional study with patients from Rio de Janeiro, São Paulo, Fortaleza (Ceará State) and Porto Alegre (Rio Grande do Sul State), assessed using the General Health Questionnaire (GHQ-12) and the Hospital Anxiety and Depression Scale (HAD). The rate of mental disorders in patients from Rio de Janeiro, São Paulo, Fortaleza and Porto Alegre were found to be, respectively, 51.9%, 53.3%, 64.3% and 57.7% with significant differences between Porto Alegre and Fortaleza compared to Rio de Janeiro after adjusting for confounders. Prevalence proportions of mental problems were especially common for females, the unemployed, those with less education and those with lower incomes. In the context of the Brazilian government's moves towards developing primary health care and reorganizing mental health policies it is relevant to consider common mental disorders as a priority alongside other chronic health conditions.

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Universidade Estadual de Campinas. Faculdade de Educação Física

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Universidade Estadual de Campinas. Faculdade de Educação Física

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Universidade Estadual de Campinas . Faculdade de Educação Física