In situ crosslinked electrospun gelatin nanofibers for skin regeneration

Due to its intrinsic similarity to the extracellular matrix, gelatin electrospun nanofibrous meshes are promising scaffold structures for wound dressings and tissue engineering applications. However, gelatin is water soluble and presents poor mechanical properties, which generally constitute relevant limitations to its applicability. In this work, gelatin was in situ crosslinked with 1,4-butanediol diglycidyl ether (BDDGE) at different concentrations (2, 4 and 6 wt%) and incubation time-points (24, 48 and 72 h) at 37 °C. The physico-chemical and biological properties of BDDGE-crosslinked electrospun gelatin meshes were investigated. Results show that by changing the BDDGE concentration it is possible to produce nanofibers crosslinked in situ with well-defined morphology and modulate fiber size and mechanical properties. Crosslinked gelatin meshes show no toxicity towards fibroblasts, stimulating their adhesion, proliferation and synthesis of new extracellular matrix, thereby indicating the potential of this strategy for skin tissue engineering.info:eu-repo/semantics/acceptedVersio

Annual ryegrass (Lolium multiflorum lam.)-ruminant relation.

Italian ryegrass is the annual cool season forage species more cultivated for grazing in southern Brazil. Its interesting forage charac-teristics, in addition to the reduced production of native pasture species during low temperatures period (Autumn-Winter) justify its large scale utilization. However, the lack of knowledge of annual ryegrass morphophysiologic characteris-tics, as well as the grazing behavior of animals, may result in animal and vegetal production gain below the real productive potential. Research data results, up to the present time, show that the adequate management of this grass species suggests defoliation periods between 300 and 500 GD and dry matter availability between 8 and 18% of animal live weight, which allow greater animal and plant production. Dry matter offer near 8% of live weight (PV) favor animal performance per area, whereas forage offer close to 18% of animal live weight favor the individual animal performance, independently of the grazing system utilized. Other factors of important impact on morpho-physiologic characteristics of the pasture and animal grazing behavior are discussed in this paper, to serve as guideline for the management of animals, in Italian ryegrass pastures and furnish subsides to future research.O azevém anual é a espécie forrageira de estação fria mais cultivada para pastejo no Sul do Brasil. Suas interessantes características forrageiras aliadas à reduzida produção da maior parte das espécies nativas durante o período de baixas temperaturas justificam a utilização em larga escala. Entretanto, o desconhecimento de suas características morfofisiológicas, bem como do hábito de pastejo dos animais, podem resultar em ganhos de produto animal e vegetal muito inferior ao potencial produtivo. Conforme a produção literária até o presente momento, o adequado manejo desta gramínea deve ter períodos entre desfolhas de 300 a 500 GD e ofertas de matéria seca entre 8 e 18% do peso corporal dos animais, as quais possibilitam maiores produções, tanto vegetal como animal. As ofertas próximas a 8% PV favorecem o desempenho animal por área; enquanto que, as ofertas próximas a 18% PV, o desempenho individual, independe do sistema de pastoreio adotado. Outros fatores de importante impacto nas características morfofisiológicas da pastagem e no comportamento dos animais em pastejo são abordados no presente artigo para de orientar o manejo dos animais em azevém anual e fornecer subsídios para futuras pesquisas

Green manure in coffee systems in the region of Zona da Mata, Minas Gerais: characteristics and kinetics of carbon and nitrogen mineralization.

The use of green manure may contribute to reduce soil erosion and increase the soil organic matter content and N availability in coffee plantations in the Zona da Mata, State of Minas Gerais, in Southeastern Brazil. The potential of four legumes (A. pintoi, C. mucunoides, S. aterrimum and S. guianensis)to produce above-ground biomass, accumulate nutrients and mineralize N was studied in two coffee plantations of subsistence farmers under different climate conditions. The biomass production of C. mucunoides was influenced by the shade of the coffee plantation.C. mucunoides tended to mineralize more N than the other legumes due to the low polyphenol content and polyphenol/N ratio. In the first year, the crop establishment of A. pintoi in the area took longer than of the other legumes, resulting in lower biomass production and N2 fixation. In the long term, cellulose was the main factor controlling N mineralization. The biochemical characteristics, nutrient accumulation and biomass production of the legumes were greatly influenced by the altitude and position of the area relative to the sun

Decomposition and nutrient release of leguminous plants in coffee agroforestry systems.

Leguminous plants used as green manure are an important nutrient source for coffee plantations, especially for soils with low nutrient levels. Field experiments were conducted in the Zona da Mata of Minas Gerais State, Brazil to evaluate the decomposition and nutrient release rates of four leguminous species used as green manures (Arachis pintoi, Calopogonium mucunoides, Stizolobium aterrimum and Stylosanthes guianensis) in a coffee agroforestry system under two different climate conditions. The initial N contents in plant residues varied from 25.7 to 37.0 g kg-1 and P from 2.4 to 3.0 g kg-1. The lignin/N, lignin/polyphenol and(lignin+polyphenol)/N ratios were low in all residues studied. Mass loss rates were highest in the first 15 days, when 25 % of the residues were decomposed. From 15 to 30 days, the decomposition rate decreased on both farms. On the farm in Pedra Dourada (PD), the decomposition constant k increased in the order C. mucunoides < S. aterrimum < S. guianensis < A. pintoi. On the farm in Araponga (ARA), there was no difference in the decomposition rate among leguminous plants. The N release rates varied from 0.0036 to 0.0096 d-1. Around 32 % of the total N content in the plant material was released in the first 15 days. In ARA, the N concentration in the S. aterrimum residues was always significantly higher than in the other residues. At the end of 360 days, the N released was 78 % in ARA and 89 % in PD of the initial content. Phosphorus was the most rapidly released nutrient (k values from 0.0165 to 0.0394 d-1). Residue decomposition and nutrient release did not correlate with initial residue chemistry and biochemistry, but differences in climatic conditions between the two study sites modified the decomposition rate constants

Indicadores De Desempenho Motor Como Preditores De Fragilidade Em Idosos Cadastrados Em Uma Unidade De Saúde Da Família

This study aimed to identify the motor performance tests more strongly associated with frailty and respective cut-off points and verify the best motor performance indicator as screening tool to discriminate frailty in elderly registered in Family Health Unit Participated in the study 139 elderly aged ≥60 years 105 women and 34 men The frailty was identified by the criteria of Fried et al (2001) The motor performance tests realized were: Handgrip strength (HS) sit-to-stand test walk test (WT) and pick up a pen test Logistic regression analysis was used to associate the motor performance tests and frailty The cutoff points were evaluated by parameters provided by Receiver Operating Characteristic curve (ROC) with significance level of 5% Data were analyzed using SPSS 210 and MedCalc The mean age was 7232 ± 84 The walk test was positively associated with frailty (OR 130; p <001) and handgrip strength in elderly women was inversely associated with frailty on feminine sex (OR 074; p <0001) The WT presented a cutoff 5s (sensitivity 889 and specificity 745%) and the handgrip in the women obtained a cutoff point 146 kgf (sensitivity 833 and specificity 790%) It was concluded that the walk test was the best screening indicator to discriminate the frailty in elderly both sexes registered in a Family Health Unit. © Edições Desafio Singular.122889

The Relevance of Maintaining Standing Forests for Global Climate Balance: A Case Study in Brazilian Forests

Estimate Net Ecosystem Exchange (NEE) is important to better understand carbon exchanges between terrestrial ecosystems and the atmosphere. Comprehend these dynamics is essential to better understand the responses of environments to ongoing climatic changes. This study aims to analyze, with AMERIFLUX and LBA network measurements, the variability of NEE and climate variables in four different tropical coverages: Pantanal, Amazonia, Caatinga and Cerrado (savanna). Furthermore, was estimate the Gross Primary Productivity (GPP). We found a distinct seasonality of meteorological variables and CO2 fluxes in each site. Despite acting mostly as a CO2 sink, some environments already show worrying source data in certain periods, pointed out as a direct effect of the reduction of photosynthesis caused by land use changes. The preserved forest plays an important role in maintaining rainfall at a regional and global level, and its maintenance makes it possible, by the way, an important tool in combating global warming via carbon sequestration by trees, which requires commitment and public policies of environmental preservation and recovery of degraded areas

Exclusion limits on the WIMP-nucleon cross-section from the Cryogenic Dark Matter Search

The Cryogenic Dark Matter Search (CDMS) employs low-temperature Ge and Si detectors to search for Weakly Interacting Massive Particles (WIMPs) via their elastic-scattering interactions with nuclei while discriminating against interactions of background particles. For recoil energies above 10 keV, events due to background photons are rejected with >99.9% efficiency, and surface events are rejected with >95% efficiency. The estimate of the background due to neutrons is based primarily on the observation of multiple-scatter events that should all be neutrons. Data selection is determined primarily by examining calibration data and vetoed events. Resulting efficiencies should be accurate to about 10%. Results of CDMS data from 1998 and 1999 with a relaxed fiducial-volume cut (resulting in 15.8 kg-days exposure on Ge) are consistent with an earlier analysis with a more restrictive fiducial-volume cut. Twenty-three WIMP candidate events are observed, but these events are consistent with a background from neutrons in all ways tested. Resulting limits on the spin-independent WIMP-nucleon elastic-scattering cross-section exclude unexplored parameter space for WIMPs with masses between 10-70 GeV c^{-2}. These limits border, but do not exclude, parameter space allowed by supersymmetry models and accelerator constraints. Results are compatible with some regions reported as allowed at 3-sigma by the annual-modulation measurement of the DAMA collaboration. However, under the assumptions of standard WIMP interactions and a standard halo, the results are incompatible with the DAMA most likely value at >99.9% CL, and are incompatible with the model-independent annual-modulation signal of DAMA at 99.99% CL in the asymptotic limit.Comment: 40 pages, 49 figures (4 in color), submitted to Phys. Rev. D; v.2:clarified conclusions, added content and references based on referee's and readers' comments; v.3: clarified introductory sections, added figure based on referee's comment