A thermoreversible supramolecular polyurethane with excellent healing ability at 45 °C

We report the synthesis and characterization of a healable, elastomeric shape recovery supramolecular polyurethane whose properties result from self-complementary π−π stacking and hydrogen bonding interactions plus phase separation. ESEM analysis and photographic images have revealed that this material can heal at 45 °C in 15 min to recover the mechanical properties of the pristine material with healing efficiencies >99%. This supramolecular polyurethane is also able to recover an applied strain of 25% within 5 min of release of the load.

Geology and geochronology of the Betara region in south-southeastern Brazil: Evidence for possible Statherian (1.80-1.75 Ga) and Calymmian (1.50-1.45 Ga) extension events

The results of geological mapping, chemical analysis and radiometric dating of metabasic rocks of Betara Formation, and mapping and dating of those present in the Betara basement nucleus together with mylonitic granodiorite and syenogranite are reported here. U-Pb analysis of bulk zircon fractions from the metabasic rocks of the basement nucleus yielded a Statherian age of 1790 +/- 22 Ma, while the metabasic rocks from the upper part of the Betara Formation yielded a Calymmian age between 1500 and 1450 Ma. This age is a minimum for the deposition of the Betara Formation. The older metabasic rocks are associated with post-tectonic, possibly anorogenic syenogranite, while the younger ones are gabbro or very porphyritic ankaramite whose REE patterns are consistent with crystallization from an N-MORB parent magma. The observations and data point to the probable events associated with extensional processes of the end of Paleoproterozoic and early Mesoproterozoic. Similar registers of Statherian (1.80-1.75 Ga) and Calymmian (1.50-1.45 Ga) extensional events are recorded in other parts of the South American and African continents. The Neoproterozoic witnessed the formation and junction of the tectonic slices which formed the Apiai domain during the assemblage of western Gondwana. (C) 2010 International Association for Gondwana Research. Published by Elsevier B.V. All rights reserved.

Structural and electrochemical characteristics of Mg((55-x))Ti(x)Ni((45-y))Pt(y) metal hydride electrodes

In recent years, Mg-Ni-based metastable alloys have been attracting attention due to their large hydrogen sorption capacities, low weight, low cost, and high availability. Despite the large discharge capacity and high activity of these alloys, the accelerated degradation of the discharge capacity after only few cycles of charge and discharge is the main shortcoming against their commercial use in batteries. The addition of alloying elements showed to be an effective way of improving the electrode performance of Mg-Ni-based alloys. In the present work, the effect of Ti and Pt alloying elements on the structure and electrode performance of a binary Mg-Ni alloy was investigated. The XRD and HRTEM revealed that all the investigated alloy compositions had multi-phase nanostructures, with crystallite size in the range of 6 nm. Moreover, the investigated alloying elements demonstrated remarkable improvements of both maximum discharge capacity and cycling life. Simultaneous addition of Ti and Pd demonstrated a synergetic effect on the electrochemical properties of the alloy electrodes. Among the investigated alloys, the best electrochemical performance was obtained for the Mg(51)Ti(4)Ni(43)Pt(2) composition (in at.%), which achieved 448 mAh g(-1) of maximum discharge capacity and retained almost 66% of this capacity after 10 cycles. In contrast, the binary Mg(55)Ni(45) alloy achieved only 248 mAh g(-1) and retained 11% of this capacity after 10 cycles. (C) 2010 Elsevier By. All rights reserved.

Quatro anos de EC 45: produtividade e presteza do magistrado e acesso à justiça como inclusão social

A emenda constitucional nº 45 trouxe sensíveis modificações à estrutura do Poder Judiciário Brasileiro e, na parte que toca ao presente trabalho, analisaremos o impacto ou as conseqüências que se poderão sentir com a introdução dos conceitos de produtividade e presteza como nortes de avaliação dos magistrados para efeitos de suas promoções na carreira. À vista de tal situação, entendemos por bem também analisar se tais mudanças geraram ou não maior acesso à Justiça e, via de conseqüência, maior inclusão social.

A reforma do estado após a emenda constitucional 45/04: a reforma do poder judiciário

Esta tese tem como propósito analisar a reforma do Poder Judiciário a partir da Emenda Constitucional 45, mais especificamente no que se refere à convivência dos critérios de eficiência e justiça. O trabalho foi estruturado com o uso do modelo teórico de formação de agenda e dados empíricos constantes de publicações, livros, decisões judiciais. A intenção foi demonstrar como foram definidos os problemas e apresentadas as soluções em um contexto de ambiguidade. Por fim, observa-se o impacto das mudanças na redefinição ainda incompleta das relações do Poder Judiciário com a sociedade.

Digestibilidade de Duas Fontes de Amido e Atividade Enzimática em Coelhos de 35 e 45 Dias de Idade

Os experimentos foram conduzidos para avaliar a digestibilidade ileal (CDILEAL) e total (CDTOTAL) do amido e a atividade das enzimas amilase (ATAM) e maltase (ATMAL) em coelhos de 35 e 45 dias alimentados com amido proveniente do milho ou da raspa de mandioca. em cada ensaio foram utilizados 20 coelhos da raça Nova Zelândia Branco, sendo dez machos e dez fêmeas, alojados individualmente em gaiolas de arame e distribuídos em um delineamento inteiramente casualizado. Ao final do período experimental, os animais foram abatidos para retirada de uma amostra do conteúdo digestivo de uma porção do jejuno e do íleo. Os CDILEAL e CDTOTAL do amido da raspa de mandioca (59,25±1,38% e 99,89±0,04%, respectivamente) foram superiores ao do milho (54,21±1,51% e 99,21±0,05%, respectivamente). O CDTOTAL dos animais com 45 dias de idade foi superior ao dos com 35 dias (99,75±0,04% vs 99,35±0,05%). A ATAM, no conteúdo do jejuno e do íleo, foi maior nos animais com 45 dias (0,952±0,118 mmol de glicose/mg/min e 0,647±0,093 mmol de glicose/mg/min, respectivamente) do que nos de 35 (0,469±0,111 mmol de glicose/mg/min e 0,375±0,088 mmol de glicose/mg/min, respectivamente). A ATMAL foi maior nos animais alimentados com raspa de mandioca do que nos que receberam milho (0,061±0,007 mmol de glicose/mg/min vs 0,032±0,007 mmol de glicose/mg/min). Conclui-se que o amido da raspa de mandioca é mais digestível que o do milho, e o sistema enzimático dos coelhos com 35 dias de idade ainda não está suficientemente desenvolvido para que ocorra otimização da digestão do amido.

Memória de reconhecimento em indivíduos adultos com mais de 45 anos

As we grow old, there are many cognitive processes which decline in the human brain. One of them is the memory, a function that allows retention and posterior use of knowledge learned during the life, understood as a result of multiple systems highly organized and spread in several neural regions. This work aimed to evaluate the recognition memory in adults over 45 years old through words and pictures recognition tasks and the use of two codification or learning conditions (same distracters and different distracters). Twelve individuals were studied (6 men and 6 women) aged between 45 and 88 years old and with similar demographic characteristics. They presented better performance on picture tasks rather than word tasks. Better results were also verified when the codification context had different distracters, which significantly reflected in a long term principally in elderly individuals. The results reached suggest that the codification context influenced the lists of pictures and words learning, mainly for the elderly ones, when compared to adults, and that these results can be related to the phenomena involved with the recognition memory, the recollection and familiarity

Crystallization and preliminary X-ray diffraction analysis of an acidic phospholipase A(2) complexed with p-bromophenacyl bromide and alpha-tocopherol inhibitors at 1.9-and 1.45-A resolution

An acidic phospholipase A(2) (PLA(2)) isolated from Bothrops jararacussu snake venom was crystallized with two inhibitors: alpha-tocopherol (vitamin E) and p-bromophenacyl bromide (BPB). The crystals diffracted at 1.45- and 1.85-Angstrom resolution, respectively, for the complexes with alpha-tocopherol and p-bromophenacyl bromide. The crystals are not isomorphous with those of the native protein, suggesting the inhibitors binding was successful and changes in the quaternary structure may have occurred. (C) 2004 Elsevier B.V. All rights reserved.

Effect of Caries Infiltration Technique and Fluoride Therapy on Microhardness of Enamel Carious Lesions

Enamel white spot subsurface lesions compromise esthetics and precede cavitation; therefore, they must be halted. The aim of this study was to evaluate the effect of a caries infiltration technique and fluoride therapy on the microhardness of enamel carious lesions. Subsurface carious lesions were produced in 60 bovine specimens with polished enamel surfaces. The specimens were divided into four groups (n=15), according to the treatment used: CON, control immersion in artificial saliva; DF, daily 0.05% fluoride solution; WF, weekly 2% fluoride gel; and IC, resin infiltration (Icon). The specimens were kept in artificial saliva and evaluated for microhardness at five points: baseline, after caries production, after four and eight weeks of treatment, and a final evaluation after being submitted to a new acid challenge. The repeated-measures analysis of variance showed significant differences according to the type of treatment (TREAT; p=0.001) and time of evaluation (EV; p=0.001). The results of the Tukey test were TREAT: CON = 45.18 (+/- 29.17)a, DF = 107.75 (+/- 67.38)b, WF = 83.25 (+/- 51.17)c, and IC = 160.83 (+/- 91.11)d. Analysis of correlation between the TREAT and EV factors showed no significant differences for DF (138.63 +/- 38.94) and IC (160.99 +/- 46.13) after the new acid challenge. The microhardness results in decreasing order after eight weeks were IC > DF > WF > CON. It was concluded that the microhardness of carious lesions increased with the infiltration of resin, while the final microhardness after a new acid challenge was similar for DF and IC.

Efeito do exercício físico contínuo e intervalado no peso e perfil bioquímico de ratas Wistar prenhes e consequências no peso da prole

INTRODUÇÃO: A prática de atividade física é reconhecida como fator importante para a preservação, recuperação e manutenção da saúde. O estímulo à prática de exercícios é crescente, mas quando relacionado à gravidez, dúvidas surgem sobre os efeitos deletérios ou salutares na mãe e no feto. OBJETIVO: O objetivo deste trabalho foi avaliar os efeitos do exercício físico intervalado e contínuo no perfil bioquímico de ratas Wistar prenhes e avaliar o efeito destes exercícios no peso da placenta e dos filhotes. MÉTODOS: Utilizou-se 45 ratas Wistar divididas em grupos de 15 animais segundo o tipo de exercício: controle (GC), exercício contínuo (GCO) e exercício intermitente (GIN). Os exercícios constituíram-se de natação forçada, cinco dias por semana, em piscinas individuais: exercício contínuo (duração de 45 minutos diários com sobrecarga de 5% do peso corporal) e intermitente (45 minutos com estímulos de 15 segundos de exercício e 15 de repouso com sobrecarga de 15% do peso corporal). O exercício foi praticado do primeiro ao 20º dia de prenhez. Após este período avaliou-se o peso e os níveis de glicemia, colesterol total, LDL-C, HDL-C e triglicérides das ratas, assim como o peso da placenta e dos filhotes. RESULTADOS: Não se observou modificação no peso das mães. Houve redução significativa nos níveis de LDL-C. O peso das placentas não variou, mas os pesos dos filhotes variaram estatisticamente entre os três grupos (4,153 ± 0,649; 3,682 ± 0,070 e 3,453 ± 0,052, respectivamente, para os filhos de mães do GC, GIN e GCO). CONCLUSÕES: Conclui-se que a prática do exercício físico contínuo e intermitente por ratas prenhes, neste modelo experimental, não interferiu no peso corpóreo das mesmas, mas interferiu no peso dos filhotes ao nascer

LOW-PROTEIN DIET IMPAIRS GLUCOSE-INDUCED INSULIN-SECRETION FROM AND CA-45 UPTAKE BY PANCREATIC RAT ISLETS

Glucose-induced insulin secretion rom and Ca-45 uptake by isolated pancreatic islets, derived from rats fed with normal (NPD) or low protein diet (LPD), were studied. Insulin secretion from both types of islets in response to increasing concentrations of glucose followed an S-shaped pattern. However, basal secretion observed at substimulatory concentrations of glucose (0-5.6 mM), as well as maximal release, obtained at 16.7 mM or higher glucose concentrations were significantly reduced in islets from LPD. Furthermore, in LPD rat islets, the dose-response curve to glucose was clearly shifted to the right compared with NPD islets, with the half-maximal response occurring at 8.5 and 14.4 mM glucose for NPD and LPD islets, respectively. In islets from NPD rats, the Ca-45 content, after 5 or 90 min in the presence of 8.3 mM glucose, was higher than that observed for islets kept at 2.8 mM glucose and increased further at 16.7 mM glucose. After 5 min of incubation, the Ca-45 uptake by LPD islets in the presence of 8.3 mM glucose was slightly higher than basal values (2.8 mM glucose); however, no further increase in the Ca-45 uptake was noticed at 16.7 mM glucose. In LPD islets a significant increase in Ca-45 uptake over basal values was registered only at 16.7 mM glucose, after 90 min of incubation. These data indicate that the poor secretary response to glucose observed in islets from LPD rats may be related to a defect in the ability of glucose to increase Ca2+ uptake and/or to reduce Ca2+ efflux from beta-cells.

Structure of human uropepsin at 2.45 angstrom resolution

The molecular structure of human uropepsin, an aspartic proteinase from the urine produced in the form of pepsinogen A in the gastric mucosa, has been determined by molecular replacement using human pepsin as the search model. Crystals belong to space group P2(1)2(1)2(1), with unit-cell parameters a = 50.99, b = 75.56, c = 89.90 Angstrom. Crystallographic refinement led to an R factor of 0.161 at 2.45 Angstrom resolution. The positions of 2437 non-H protein atoms in 326 residues have been determined and the model contains 143 water molecules. The structure is bilobal, consisting of two predominantly beta -sheet lobes which, as observed in other aspartic proteinases, are related by a pseudo-twofold axis. A model of the uropepsin-pepstatin complex has been constructed based on the high-resolution crystal structure of pepsin complexed with pepstatin.