Structure and mechanical properties of blends of an amorphous polyamide and an amorphous copolyester

This article deals with the structure and mechanical properties of blends of an amorphous copolyester (PCTG) and an amorphous polyamide (aPA) which were directly prepared during the plasticization step of an injection molding process. The blends were composed by an almost pure aPA phase, and a PCTG‐rich phase where some aPA subparticles are present. The morphology of the blends showed both rather fine dispersed particles and occasionally large particles with occluded subparticles. This complex morphology indicated a low interface tension attributed to the presence of some aPA in the PCTG‐rich phase of the blends. The almost linear behavior of the modulus of elasticity was attributed to the constancy of the main structural characteristics upon blending and the equally linear ductility to the good adhesion level and the presence of thin and elongated morphologies. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40785.     

Hybridization behavior of mixed DNA/alkylthiol monolayers on gold: characterization by surface plasmon resonance and 32P radiometric assay

Nucleic acid assay from a complex biological milieu is attractive but currently difficult and far from routine. In this study, DNA hybridization from serum dilutions into mixed DNA/mercaptoundecanol (MCU) adlayers on gold was monitored by surface plasmon resonance (SPR). Immobilized DNA probe and hybridized target densities on these surfaces were quantified using 32P-radiometric assays as a function of MCU diluent exposure. SPR surface capture results correlated with radiometric analysis for hybridization performance, demonstrating a maximum DNA hybridization on DNA/MCU mixed adlayers. The maximum target surface capture produced by MCU addition to the DNA probe layer correlates with structural and conformational data on identical mixed DNA/MCU adlayers on gold derived from XPS, NEXAFS, and fluorescence intensity measurements reported in a related study (Lee, C.-Y.; Gong, P.; Harbers, G. M.; Grainger, D. W.; Castner, D. G.; Gamble, L. J. Anal. Chem. 2006, 78, 3316-3325.). MCU addition into the DNA adlayer on gold also improved surface resistance to both nonspecific DNA and serum protein adsorption. Target DNA hybridization from serum dilutions was monitored with SPR on the optimally mixed DNA/MCU adlayers. Both hybridization kinetics and efficiency were strongly affected by nonspecific protein adsorption from a complex milieu even at a minimal serum concentration (e.g., 1%). No target hybridization was detected in SPR assays from serum concentrations above 30%, indicating nonspecific protein adsorption interference of DNA capture and hybridization from complex milieu. Removal of nonsignal proteins from nucleic acid targets prior to assay represents a significant issue for direct sample-to-assay nucleic acid diagnostics from food, blood, tissue, PCR mixtures, and many other biologically complex sample formats.     

Multiresidue method for the determination of quinolone antibiotics in bovine raw milk by capillary electrophoresis-tandem mass spectrometry

A new analytical method based on capillary zone electrophoresis-tandem mass spectrometry (CZE-MS/MS) is proposed and validated for the identification and simultaneous quantification of eight quinolones for veterinary use in bovine raw milk. The studied quinolones include danofloxacin, sarafloxacin, ciprofloxacin, marbofloxacin, enrofloxacin, difloxacin, oxolinic acid, and flumequine, whose contents are regulated by the EU Council Regulation no. 2377/90 in animal edible tissues. Different parameters (i.e., separation buffer composition and electrospray conditions) were optimized in order to obtain both an adequate CE separation and a high sensitivity, using experimental design methodology to consider the interactions among the studied variables. MS/MS experiments using an ion trap as analyzer operating in the multiple reaction monitoring mode were carried out to achieve the minimum number of identification points according to the 2002/657/EC European Decision. For the quantification in bovine raw milk samples, a two-step solid-phase extraction procedure was developed using Oasis MAX and HLB cartridges without protein precipitation. Satisfactory results were obtained in terms of linearity (r2 between 0.989 and 0.992) and precision (RSD below 18%). The limits of detection and quantification (below 6 and 24 ppb, respectively) were in all cases lower than the maximum residues limits tolerated for these compounds in milk, the recoveries ranging from 81 to 110%, indicating the potential of the CZE-MS/MS for the analysis of regulated quinolone antibiotics in the food quality and safety control areas.     

Preparation and antimicrobial activity of gelatin microparticles containing propolis against oral pathogens

Gelatin microparticles containing propolis ethanolic extractive solution were prepared by spray-drying technique. Particles with regular morphology, mean diameter ranging of 2.27 μm to 2.48 μm, and good entrapment efficiency for propolis were obtained. The in vitro antimicrobial activity of microparticles was evaluated against microorganisms of oral importance (Enterococcus faecalis, Streptococcus salivarius, Streptococcus sanguinis, Streptococcus mitis, Streptococcus mutans, Streptococcus sobrinus, Candida albicans, and Lactobacillus casei). The utilized techniques were diffusion in agar and determination of minimum inhibitory concentration. The choice of the method to evaluate the antimicrobial activity of microparticles showed be very important. The microparticles displayed activity against all tested strains of similar way to the propolis, showing greater activity against the strains of E. salivarius, S. sanguinis, S. mitis, and C. albicans.     

Advanced Spectrum Functionalities for Future Radio Networks

The IST WINNER (WINNER is part of the European Union research programme within the Sixth Framework Programme (FP6) of the European Information Society Technology (IST) programme. Accepted for the Wireless World Research Forum (WWRF) 2006 Industrial Forum (Kermoal, J.-P. et al. (2006). Spectrum deployment scenarios and advanced functionalities development in WINNER.) project is a major European research activity to develop a flexible and scalable radio access system for 4G, which is addressing the challenging requirements for future systems such as those of the International Telecommunication Union (ITU) in terms of overall performance, flexibility, scalability and optimized spectrum usage. In this article, the Radio Resource Management (RRM) spectrum functionalities are defined and subsequently analyzed. The proposed RRM spectrum architecture developed will result in reducing the time required to tailor new services to network operators. Furthermore, the flexible spectrum access and usage leads to more capable and faster services with high Quality-of-Service (QoS) giving more user satisfaction than conventional networks. The inherent centralization and decentralization degree for the functionalities is outlined and discussed since flexible spectrum techniques on both fast and slow basis will lead to a better utilization of spectrum.

A construct validation study of the Response Styles Questionnaire Rumination scale in participants with a recent-onset major depressive episode.

This study examined the construct validity and clinical utility of S. Nolen-Hoeksema's (1991) Response Styles Questionnaire (RSQ) Rumination scale. Eighty-eight participants with recent-onset major depressive episodes were assessed and followed for 6 months, using semistructured interviews and self-report inventories. The RSQ Rumination scale exhibited poor 6-month stability and appeared to be closely linked to participants' clinical status–mood state. The scale was significantly correlated with conceptually related constructs such as emotion-focused coping, negative affectivity–temperament, and self-criticism. However, baseline negative temperament and self-criticism predicted key aspects of the 6-month course and outcome of major depressive episodes, whereas baseline rumination did not. Finally, rumination appeared to be closely associated with the severity of the depressive episode, rather than defining a distinct clinical subtype. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Robustness margin for attitude control of a four rotor mini-rotorcraft: Case of study

In this paper we present new results to compute the robustness margin of an attitude control algorithm for a quad-rotor mini-rotorcraft known as X4-flyer. The maximum parametric uncertainty is calculated when multivariable PD controller is used to stabilize the attitude of the aerial vehicle. This work is based on the value set characterization approach of the mathematical model for the closed-loop control system, which is represented by an interval plant with time delay. The zero exclusion principle is used to compute the robustness margin of the closed-loop system. This approach transforms the original robust stability problem into simple problem of graphic inspection, where we only needed to verify if a graph on the complex plane does not contain the origin of the plane. Additionally, different experiments were made in order to validate theoretical results; these experimental results will be presented at the end of this work.     

创意设计“六诫律”

德国设计大师Dieter Rams在上世纪八十年代初期曾对其当时所出的现实环境深感忧虑，他形容设计行业仿佛是一个“充斥着奇异形状，色彩和噪音的让人无法理解的混沌世界”。而他始终在考虑着一个问题：“我的设计到底是不是好设计？”带着这个问题他开始重新审视自己和同时代设计师所走过的轨迹，在进行了大量的考察研究后，总结出了优秀设计的十大诫律。     

Testing a social-cognitive model of HIV transmission risk behaviors in HIV-infected MSM with and without depression.

Objective: Social-cognitive models have been used to explain health risk behaviors in numerous populations, including people with HIV. However, these models generally do not account for the influence of clinically significant psychological problems such as major depression. Design: This study examined whether a social-cognitive model would explain recent sexual transmission risk behavior among sexually active HIV-infected men who have sex with men (MSM) who meet or do not meet screening criteria for major depression. Main Outcome Measures: Participants (n = 403) completed self-report assessments of negative expectancy, social models, and self-efficacy (SE) related to condom use, as well as recent STRB and a screening measure for major depression. Multiple group modeling was used to examine whether condom use SE explained associations of negative expectancy and social models for condom use with recent STRB among participants who screened positive (n = 47) or negative (n = 356) for major depression. Results: The multiple group model fit the data well (χ2(36) = 30.55, p = .73; CFI = 1.00; RMSEA     

Further validation of a cigarette purchase task for assessing the relative reinforcing efficacy of nicotine in college smokers.

The authors sought to further validate a cigarette purchase task (CPT), a self-report analogue of a progressive-ratio operant schedule, for the assessment of the relative reinforcing efficacy (RRE) of nicotine in smokers. The measure was assessed in terms of its correspondence to typically observed operant behavior, convergent validity, and divergent validity. Participants were 33 individuals (58% male, age M = 19.30 years) who smoked at least weekly (M = 5.31 cigarettes/day) and underwent a single assessment session. Data from the CPT exhibited the predicted inverse relationship between consumption and price, the predicted relationship between consumption and expenditure, and a heterogeneous pattern of interrelationships among the indices of reinforcement. In addition, 2 indices from the measure, intensity of demand and maximum expenditure for cigarettes, exhibited robust convergent and divergent validity. Although this is an incipient research area and the current study used a relatively small sample, these findings support the validity of a CPT as a time- and cost-efficient method for assessing nicotine reinforcement. Theoretical implications of the findings, limitations, and future directions are also discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)