Morfologia, propriedades termicas e mecanicas de filmes de proteina isolada de soja / dodecilsulfato de sodio / policaprolactona-triol

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências Físicas e Matemáticas. Programa de Pós-Graduação em Química.Neste trabalho, filmes de proteína isolada de soja (SPI)-dodecilsulfato de sódio (SDS)-policaprolactona-triol (PCL-T) foram preparados por evaporação em solvente comum a partir de soluções contendo diferentes concentrações de SDS e PCL-T. As propriedades físico-químicas dos filmes resultantes foram estudadas por métodos térmicos de análise (temperatura de transição vítrea - Tg - e degradação térmica) e ensaios mecânicos (Módulo de Young, Alongamento (L) e Tensão (T) na ruptura), também foi avaliada a quantidade de umidade e a morfologia. Os resultados foram interpretados com base nas interações intermoleculares (eletrostáticas, dipolo-dipolo e hidrofóbicas) entre os componentes do filme, considerando-se também as mudanças na estrutura da SPI conforme sugeriram as medidas de fluorescência. De acordo com os resultados obtidos, a degradação térmica dos filmes de SPI ocorre em uma única etapa que tem início em 292 ºC e atinge a máxima velocidade de degradação em 331 ºC. Quando SDS ou SDS/PCL-T são adicionados ao sistema, a estabilidade térmica do mesmo decresce, sendo que a temperatura inicial de degradação é 29 ºC menor para os filmes de SPI/SDS - 67/37, e 42 ºC menor para os filmes de SPI/SDS/PCL-T - 39/22/39 em comparação ao valor tipicamente observado para filmes de SPI. A variação da energia de ativação (E) em função da fração de perda de massa (a), assim como dos valores médios de E comportam-se de maneira similar. A energia de ativação decresce de 160 kJ mol-1 (filmes de SPI) para 128 kJ mol-1 (filmes de SPI/SDS; 67/37) (32 kJ mol-1 inferior) e para 123 kJ mol-1 (filmes de SPI/SDS/PCL-T ; 39/22/39) (37 kJ mol-1 inferior). Os espectros FTIR dos produtos gasosos liberados durante a degradação térmica de filmes submetidos à temperatura correspondente de máxima velocidade de degradação (TMAX) revelaram bandas de absorção características de CO2(g), CO(g), NH3(g), C=O, C-H, C=C e CH2, sugerindo que o mecanismo da reação de degradação compreende primeiramente a quebra de ligações mais fracas como C-N, C(O)-NH, C(O)-NH2 e -NH2, as quais estão presentes em diversas funções químicas encontradas na SPI. O efeito da presença de SDS e SDS/PCL-T sobre as propriedades mecânicas e morfológicas dos filmes mostrou-se estritamente dependente da umidade presente nos mesmos. As modificações mais importantes foram observadas para filmes de SPI/SDS/PCL-T acondicionados em umidade relativa de 75% cuja concentração de PCL-T é superior ou igual a 18%. Nestes casos, um decréscimo significante no módulo de Young de 1424 MPa (filmes de SPI) para aproximadamente 50 MPa foi observado, em paralelo à diminuição na Tg (de 150°C para to 135°C) e ao aumento de L (de 2% para 90%). O efeito plastificante da PCL-T pôde também ser evidenciado quando as amostras foram expostas à umidade relativa de 54% ou inferior. Neste caso, porém, as modificações foram menos acentuadas (Tg ~ 150°C, módulo de Young ~ 650 MPa, L ~ 5 %). As micrografias referentes à seção transversal dos filmes revelaram a formação de uma matriz porosa

Controlled One-Pot Synthesis of Polystyrene-block-Polycaprolactone Copolymers by Simultaneous RAFT and ROP

A convenient one-pot method for the controlled synthesis of polystyrene- block -polycaprolactone (PS- b -PCL) copolymers by simultaneous reversible addition?fragmentation chain transfer (RAFT) and ring-opening polymerization (ROP) processes is reported. The strategy involves the use of 2-(benzylsulfanylthiocarbonylsulfanyl)ethanol (1) for the dual roles of chain transfer agent (CTA) in the RAFT polymerization of styrene and co-initiator in the ROP of ε -caprolactone. One-pot poly merizations using the electrochemically stable ROP catalyst diphenyl phosphate (DPP) yield well-defi ned PS- b -PCL in a relatively short reaction time (≈4 h; Mn = 9600−43 600 g mol−1 ; Mw/Mn = 1.21−1.57). Because the hydroxyl group is strategically located on the Z substituent of the CTA, segments of these diblock copolymers are connected through a trithiocarbonate group, thus offering an easy way for subsequent growth of a third segment between PS and PCL. In contrast, an oxidatively unstable Sn(Oct) 2 ROP catalyst reacts with (1) leading to multimodal distributions of polymer chains with variable composition.Fil: de Freitas, Augusto G. O.. Universidade Federal de Santa Maria; BrasilFil: Trindade, Suelen G.. Universidade Federal de Santa Maria; BrasilFil: Muraro, Paulo I. R.. Universidade Federal de Santa Maria; BrasilFil: Schmidt, Vanessa. Universidade Federal de Santa Maria; BrasilFil: Satti, Angel Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahía Blanca. Planta Piloto de Ingeniería Química (i); ArgentinaFil: Villar, Marcelo Armando. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahía Blanca. Planta Piloto de Ingeniería Química (i); ArgentinaFil: Ciolino, Andrés Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahía Blanca. Planta Piloto de Ingeniería Química (i); ArgentinaFil: Giacomelli, Cristiano. Universidade Federal de Santa Maria; Brasi

Combined mathematical modelling and experimentation to predict polymersome uptake by oral cancer cells

This study is motivated by understanding and controlling the key physical properties underlying internalisation of nano drug delivery. We consider the internalisation of specific nanometre size delivery vehicles, comprised of self-assembling amphiphilic block copolymers, called polymersomes that have the potential to specifically deliver anticancer therapeutics to tumour cells. The possible benefits of targeted polymersome drug delivery include reduced off-target toxic effects in healthy tissue and increased drug uptake by diseased tissue. Through a combination of in vitro experimentation and mathematical modelling, we develop a validated model of nanoparticle uptake by cells via the clathrin-mediated endocytotic pathway, incorporating receptor binding, clustering and recycling. The model predicts how the characteristics of receptor targeting, and the size and concentration of polymersomes alter uptake by tumour cells. The number of receptors per cell was identified as being the dominant mechanism accounting for the difference between cell types in polymersome uptake rate. From the Clinical Editor - This article reports on a validated model developed through a combination of in vitro experimentation and mathematical modeling of nanoparticle uptake by cells via the clathrin-mediated endocytotic pathway. The model incorporates receptor binding, clustering, and recycling and predicts how the characteristics of receptor targeting, the size and concentration alter polymersome uptake by cancer cells

Differential cross section measurements for the production of a W boson in association with jets in proton–proton collisions at √s = 7 TeV

Measurements are reported of differential cross sections for the production of a W boson, which decays into a muon and a neutrino, in association with jets, as a function of several variables, including the transverse momenta (pT) and pseudorapidities of the four leading jets, the scalar sum of jet transverse momenta (HT), and the difference in azimuthal angle between the directions of each jet and the muon. The data sample of pp collisions at a centre-of-mass energy of 7 TeV was collected with the CMS detector at the LHC and corresponds to an integrated luminosity of 5.0 fb[superscript −1]. The measured cross sections are compared to predictions from Monte Carlo generators, MadGraph + pythia and sherpa, and to next-to-leading-order calculations from BlackHat + sherpa. The differential cross sections are found to be in agreement with the predictions, apart from the pT distributions of the leading jets at high pT values, the distributions of the HT at high-HT and low jet multiplicity, and the distribution of the difference in azimuthal angle between the leading jet and the muon at low values.United States. Dept. of EnergyNational Science Foundation (U.S.)Alfred P. Sloan Foundatio

Juxtaposing BTE and ATE – on the role of the European insurance industry in funding civil litigation

One of the ways in which legal services are financed, and indeed shaped, is through private insurance arrangement. Two contrasting types of legal expenses insurance contracts (LEI) seem to dominate in Europe: before the event (BTE) and after the event (ATE) legal expenses insurance. Notwithstanding institutional differences between different legal systems, BTE and ATE insurance arrangements may be instrumental if government policy is geared towards strengthening a market-oriented system of financing access to justice for individuals and business. At the same time, emphasizing the role of a private industry as a keeper of the gates to justice raises issues of accountability and transparency, not readily reconcilable with demands of competition. Moreover, multiple actors (clients, lawyers, courts, insurers) are involved, causing behavioural dynamics which are not easily predicted or influenced. Against this background, this paper looks into BTE and ATE arrangements by analysing the particularities of BTE and ATE arrangements currently available in some European jurisdictions and by painting a picture of their respective markets and legal contexts. This allows for some reflection on the performance of BTE and ATE providers as both financiers and keepers. Two issues emerge from the analysis that are worthy of some further reflection. Firstly, there is the problematic long-term sustainability of some ATE products. Secondly, the challenges faced by policymakers that would like to nudge consumers into voluntarily taking out BTE LEI

Penilaian Kinerja Keuangan Koperasi di Kabupaten Pelalawan

This paper describe development and financial performance of cooperative in District Pelalawan among 2007 - 2008. Studies on primary and secondary cooperative in 12 sub-districts. Method in this stady use performance measuring of productivity, efficiency, growth, liquidity, and solvability of cooperative. Productivity of cooperative in Pelalawan was highly but efficiency still low. Profit and income were highly, even liquidity of cooperative very high, and solvability was good

Search for stop and higgsino production using diphoton Higgs boson decays

Results are presented of a search for a "natural" supersymmetry scenario with gauge mediated symmetry breaking. It is assumed that only the supersymmetric partners of the top-quark (stop) and the Higgs boson (higgsino) are accessible. Events are examined in which there are two photons forming a Higgs boson candidate, and at least two b-quark jets. In 19.7 inverse femtobarns of proton-proton collision data at sqrt(s) = 8 TeV, recorded in the CMS experiment, no evidence of a signal is found and lower limits at the 95% confidence level are set, excluding the stop mass below 360 to 410 GeV, depending on the higgsino mass