Advances and Applications of Biodegradable Elastomers in Regenerative Medicine

When elastomers were first proposed as useful materials for regenerative medicine a few decades ago, their high versatility and suitability for a diverse and wide range of in vivo applications could not have been predicted. Due to their ability to recover after deformation, these materials were first introduced in tissue engineering in an attempt to mimic the mechanical properties of the extracellular matrix. Furthermore, elastomeric characteristics have been described as important criteria for cell interaction by modulating cellular behavior. From soft to hard tissues, elastomers have demonstrated degradation, mechanical, and biocompatibility requirements in accordance with the target tissue. In this feature article, biodegradable synthetic polyester elastomers that have been reported in the literature are discussed, with special focus on those that show promise for in vivo tissue replacement. Their satisfactory performance in vivo shows the promise of elastomers for use in regenerative medicine. However, further investigation is required to demonstrate the prospect of elastomer‐based therapies in clinical trials.     

Assessing regulatory emotional self-efficacy in three countries.

The Regulatory Emotional Self-Efficacy (RESE) scale was developed to assess perceived self-efficacy in managing negative (NEG) and in expressing positive (POS) affect (G. V. Caprara & M. Gerbino, 2001). In this study of young adults, the factorial structure of the RESE scale was found to be similar in Italy, the United States, and Bolivia. In addition to a factor for POS, NEG was represented by a second-order factor of 2 different negative affects: despondency-distress (DES) and anger-irritation (ANG). Overall, there was partial invariance at both metric and scalar levels across gender and countries. Discriminant and convergent validity of the RESE scale was further examined in the Italian sample. Stronger patterns of association of POS with prosocial behavior, of ANG with low aggressive behavior problems and irritability, and of DES with low anxiety/depressive problems and shyness and high self-esteem were found. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Chemical changes in the volatile fractions of Brazilian honeys during storage under tropical conditions

The chemical transformations of the volatile fractions of two different Brazilian honeys (cashew and marmeleiro) were monitored during storage under tropical conditions. Five systems, namely: 1 – fresh samples; 2 and 3 – samples heated for 3 and 6 months at 35 – 40 °C; 4 and 5 – samples kept under similar conditions to systems 2 and 3, but containing sodium metabisulphite, were tested. The transformations noted in the volatile fractions of these honeys could be mainly associated to acid or enzymatic hydrolysis of glycosides, volatilization, oxidation or esterification processes. The formation of furan derivatives, linalool derivatives and esters appears to be quite affected by the sodium metabisulphite. The concentrations of most powerful odorants increased during the storage (e.g.: benzenemethanol and isovaleric acid) or remained unchangeable (e.g.: vanillin, furfuryl mercaptan, 2-methoxyphenol).     

Robust Multilayer Control for Enhanced Wireless Telemedical Video Streaming

M-health is an emerging area of research and one of the key challenges in future research in this area is medical video streaming over wireless channels. Contrasting requirements of almost lossless compression and low available bandwidth have to be tackled in medical quality video streaming in ultrasound and radiology applications. On one side, compression techniques need to be conservative, in order to avoid removing perceptively important information; on the other side, error resilience and correction should be provided, with the constraint of a limited bandwidth. A quality-driven, network-aware approach for joint source and channel coding based on a controller structure specifically designed for enhanced video streaming in a robotic teleultrasonography system is presented. The designed application based on robotic teleultrasonography is described and the proposed method is simulated in a wireless environment in two different scenarios; the video quality improvement achievable through the proposed scheme in such an application is remarkable, resulting in a peak signal-to-noise ratio (PSNR) improvement of more than 4 dB in both scenarios.     

Voces abriendo caminos (voices foraging paths): A qualitative study of the career development of notable Latinas.

This study used qualitative methodology to investigate the career development of 20 notable Latinas. The emergent theory proposed that Latina career development is influenced by sociopolitical, cultural, contextual, and personal variables. Results suggested that (a) career paths tended to be unplanned and nonlinear; (b) background variables, socioeconornic status, and educational experiences influenced the participants' sense of self and career motivation; (c) family, culture, and cultural identity werr influential; (d) relational support systems, particularly those that involved extended family, spouses, and mentors, were important; and (e) the participants' optimism, persistence, passion, and capacity for cognitive reframing helped them cope with challenges and remain true to their values, beliefs, and sense of self. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Motor sequencing deficits in schizophrenia: A comparison with Parkinson's disease.

Motor abnormalities occur in schizophrenia (SZ) and may arise from striatal dysfunction. This study examined whether the pattern of performance on simple and complex motor abilities in SZ was similar to that of patients with Parkinson's disease (PD). Quantitative tests of speeded movement and motor and cognitive sequencing were used to assess 25 SZ, 16 PD, and 84 normal controls (NCs). Sequencing performance was also examined with motor rigidity taken into account. Compared with the NC group, the SZ and PD groups were impaired on measures of motor rigidity and motor sequencing. With rigidity accounted for, the SZ group was significantly more impaired than the PD group on motor sequencing; cognitive and motor processes contributed to the motor deficit. Cognitive sequencing performance predicted motor sequencing performance in PD but not SZ. Although both SZ and PD resulted in significant motor and cognitive sequencing deficits, the pattern and correlates of these deficits differ, suggesting that the affected neural systems underlying motor deficits in SZ are different from those involved in PD. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effect of excitatory amino acid, dopamine, and oxytocin receptor antagonists on noncontact penile erections and paraventricular nitric oxide production in male rats.

In male rats, noncontact erections occur concomitantly with an increase in NO?- and NO?- in the paraventricular nucleus of the hypothalamus (PVN). In the present study, both responses were reduced by the blockade of PVN excitatory amino acid receptors by dizocilpine, (+)-MK-801(1 and 5 μg), but not by 6-cyano-7-nitro-quinoxaline-2,3-dione (5 μg) or (±)-2-amino-4-phosphono-butanoic acid (5 μg). Also ineffective when injected into the PVN were the dopamine antagonists SCH 23390 (5 μg), S(+)-raclopride (10 μg), and cis-flupenthixol (10 μg), and the oxytocin antagonist d(CH?)?Tyr(Me)2-Orn?-vasotocin (1 μg). However, when the last was given into the lateral ventricles, it reduced noncontact erections without modifying NO?- and NO?- increases. These results suggest that excitatory amino acid transmission increases in the PVN during noncontact erections. This may contribute to increased NO production in the PVN, and it may activate oxytocin neurons mediating this sexual response. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

An electronically tunable microstrip bandpass filter using thin-film Barium-Strontium-Titanate (BST) varactors

A tunable third-order combline bandpass filter using thin-film barium-strontium-titanate varactors and fabricated on a sapphire substrate is reported. Application of 0-200-V bias varied the center frequency of the filter from 2.44 to 2.88 GHz (16% tuning) while achieving a 1-dB bandwidth of 400 MHz. The insertion loss varied from 5.1 dB at zero bias to 3.3 dB at full bias, while the return loss exceeded 13 dB over the range. The third-order intercept of the filter was found to be 41 dBm.     

Reliable real-time robot operation employing intelligent forward recovery

Modern computer-controlled robots typically fail at their tasks whenever they encounter an error, no matter how minor. The physical environment of a typical assembly robot is too unstructured to benefit from conventional software approaches to reliability. We present an approach which interfaces the real-time operation of the robot with an intelligent subsystem that performs error analysis and forward recovery if a failure occurs. Our approach involves a special representation of the robot's program that efficiently tracks the robot's operation in real time and is easy to modify to include automatically generated recovery procedures.     

Effects of partial closure and friction on a radial crack emanating from a circular hole

A radial crack emanating from a circular hole in an infinite sheet under tension is considered. Depending on the crack length and location, the crack may be partially or completely open or closed. In case of closure, interfacial friction influences the solution.Stress intensity factors for inclined tension or in-plane shear are computed and compared with those obtained when closure and friction are ignored.

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Résumé On considère une fissure radiale provenant d'un trou circulaire dans une tôle mince infinie sous tension. Selon la longueur et la localisation de la fissure, celle-ci peut être partiellement ou totalement ouverte ou fermeée. Dans ce dernier cas, la résolution du champ de contrainte est influencée par la friction entre faces de la fissure.On calcule les facteurs d'intensité de contrainte correspondant à une tension dont l'axe est incliné par rapport à la fissure, ou à un cisaillement dans le plan, et on compare les valeurs obtenues à celles correspondant aux cas où l'on ignore la fermeture de la fissure et la friction entre ses faces.