Changes in actin and tubulin expression in osteogenic cells cultured on bioactive glass‐based surfaces

The present study evaluated whether the changes in the labeling pattern of cytoskeletal proteins in osteogenic cells cultured on bioactive glass‐based materials are due to altered mRNA and protein levels. Primary rat‐derived osteogenic cells were plated on Bioglass® 45S5, Biosilicate®, and borosilicate (bioinert control). The following parameters were assayed: (i) qualitative epifluorescence analysis of actin and tubulin; (ii) quantitative mRNA and protein expression for actin and tubulin by real‐time PCR and ELISA, respectively, and (iii) qualitative analysis of cell morphology by scanning electron microscopy (SEM). At days 3 and 7, the cells grown on borosilicate showed typical actin and tubulin labeling patterns, whereas those on the bioactive materials showed roundish areas devoid of fluorescence signals. The cultures grown on bioactive materials showed significant changes in actin and tubulin mRNA expression that were not reflected in the corresponding protein levels. A positive correlation between the mRNA and protein as well as an association between epifluorescence imaging and quantitative data were only detected for the borosilicate. SEM imaging of the cultures on the bioactive surfaces revealed cells partly or totally coated with material aggregates, whose characteristics resembled the substrate topography. The culturing of osteogenic cells on Bioglass® 45S5 and Biosilicate® affect actin and tubulin mRNA expression but not the corresponding protein levels. Changes in the labeling pattern of these proteins should then be attributed, at least in part, to the presence of a physical barrier on the cell surface as a result of the material surface reactions, thus limiting fluorescence signals. Microsc. Res. Tech. 78:1046–1053, 2015. © 2015 Wiley Periodicals, Inc.     

Global‐view coefficients: a data management solution for parallel quantum Monte Carlo applications

Quantum Monte Carlo (QMC) applications perform simulation with respect to an initial state of the quantum mechanical system, which is often captured by using a cubic B‐spline basis. This representation is stored as a read‐only table of coefficients and accesses to the table are generated at random as part of the Monte Carlo simulation. Current QMC applications, such as QWalk and QMCPACK, replicate this table at every process or node, which limits scalability because increasing the number of processors does not enable larger systems to be run. We present a partitioned global address space approach to transparently managing this data using Global Arrays in a manner that allows the memory of multiple nodes to be aggregated. We develop an automated data management system that significantly reduces communication overheads, enabling new capabilities for QMC codes. Experimental results with QWalk and QMCPACK demonstrate the effectiveness of the data management system. Copyright © 2016 John Wiley & Sons, Ltd.     

The Reactivity of Difluorocarbene with Hydroxylamines: Synthesis of Carbamoyl Fluorides

Carbamoyl fluorides are formed in reactions of hydroxylamines with difluorocarbene generated from sodium bromodifluoroacetate as readily available and non‐toxic carbene precursor. The process shows a high functional group tolerance, and the reaction path has been rationalized by computational calculations.

     

Experimental investigation of a solar cooling absorption system operating without any backup system under tropical climate

In the last few years, thermal comfort research in summer has significantly increased the electricity consumption in buildings. This is mainly due to the use of conventional air conditioning systems operating with mechanical vapor compression. Solar cooling systems appear to be an interesting solution to solve this problem. But the understanding of this technology has to be refined through fundamental studies by developing numerical simulations. Moreover, the study of pilot plants is a practical method to gain experience by analyzing all the processes behind solar cooling technology. This paper presents an experimental study of a solar cooling absorption system implemented in Reunion Island, located in the southern hemisphere near the Capricorn Tropic. The particularity of this project is to achieve an effective cooling of classrooms, by a solar cooling system without any backup systems (hot or cold). The aim of this experimental study is to define the limits of the use of such system under tropical climate conditions without setting a set point temperature. Indoor thermal comfort is achieved by a self-stabilizing operating system that maintains the indoor temperature 6 °C below the outdoor temperature. During some critical periods of the year, when the outdoor temperature is very high and when the solar cooling system cannot provide enough refrigerating production, thermal comfort inside the building is achieved by using ceiling fans. Firstly we will present the installation and the choices we made in the control and design process. In the second part, an analysis of the experimental results will be presented.     

Brazilian red propolis: unreported substances, antioxidant and antimicrobial activities

BACKGROUND: Chloroform, ethyl acetate and methanol extracts of a sample of red propolis from the state of Alagoas (northeast Brazil) were analyzed by gas chromatography–mass spectrometry and high‐performance liquid chromatography–diode array detection–electrospray ionization‐mass spectrometry. Antimicrobial and antioxidant activities were also obtained. RESULTS: The propolis sample contained low content of narigenin‐8‐C‐hexoside, this being the first report of a C‐glycoside in propolis. The main constituent found was characterized as 3,4,2′,3′‐tetrahydroxychalcone. Other important constituents were the chalcone isoliquiritigenin, the isoflavans (3S)‐vestitol, (3S)‐7‐O‐methylvestitol, the pterocarpan medicarpin, the phenylpropenes trans‐anethol, methyl eugenol, elimicin, methoxyeugenol and cis‐asarone, and the triterpenic alcohols lupeol and α‐ and β‐ amyrins. The methanol extract exhibited high antioxidant activities by 2,2‐diphenyl‐1‐picrylhydrazyl and β‐carotene/linoleic acid assay methods, and antimicrobial activity toward Gram‐positive and Gram‐negative bacteria. CONCLUSION: Structures are suggested for new substances never before seen in any kind of propolis. This is the first report of 3,4,2′,3′‐tetrahydroxychalcone and a flavone C‐glycoside in a propolis sample. Copyright © 2011 Society of Chemical Industry     

Effect of milk base and starter culture on acidification,texture, and probiotic cell counts in fermented milk processing

In the present work, the compared effect of milk base and starter culture on acidification, texture, growth, and stability of probiotic bacteria in fermented milk processing, was studied. Two strains of probiotic bacteria were used, Lactobacillus acidophilus LA5 and L. rhamnosus LR35, with two starter cultures. One starter culture consisted only of Streptococcus thermophilus ST7 (single starter culture); the other was a yogurt mixed culture with S. thermophilus ST7 and L. bulgaricus LB12 (mixed starter culture). For the milk base preparation, four commercial dairy ingredients were tested (two milk protein concentrates and two casein hydrolysates). The resulting fermented milks were compared to those obtained with control milk (without enrichment) and milk added with skim milk powder. The performance of the two probiotic strains were opposite. L. acidophilus LA5 grew well on milk but showed a poor stability during storage. L. rhamnosus LR35 grew weakly on milk but was remarkably stable during storage. With the strains tested in this study, the use of the single starter culture and the addition of casein hydrolysate gave the best probiotic cell counts. The fermentation time was of about 11 h, and the probiotic level after five weeks of storage was greater than 106 cfu/ml for L. acidophilus LA5 and 10(7) cfu/ml for L. rhamnosus LR35. However, an optimization of the level of casein hydrolysate added to milk base has to be done, in order to improve texture and flavor when using this dairy ingredient.     

A Technique for Controllable Vapor-Phase Deposition of l-Nitro[14C]pyrene and Other Polycyclic Aromatic Hydrocarbons onto Environmental Particulate Matter

To produce environmental particles fortified with a polycyclic aromatic hydrocarbon (PAH) for toxicology studies, an experimental apparatus was devised for deposition of the desired chemical species onto particles in a controlled and reproducible manner. The technique utilized consists of dispersion of the particles on a gaseous stream at a controlled rate, thermal vaporization of a solution of PAH, delivery of the vaporized PAH into the aerosol of particles at a controlled rate, subsequent condensation of the PAH onto the particles, and final recovery of the coated particles. The effectiveness of this approach was demonstrated by vapor-coating a ¹⁴C-labeled PAH (l-nitro[¹⁴C]-pyrene) onto diesel engine exhaust particles that had previously been collected by tunnel dilution sampling techniques. Using the ¹⁴C label as a tracer, the coated particles were characterized with respect to degree of coating, integrity of particle structure and absence of chemical decomposition of the coating substrate. This study demonstrates that the described method provides a controllable means for depositing a substance uniformly and with a high coating efficiency onto aerosolized particles. The technique was also used to vapor-coat benzo(a)pyrene onto diesel engine exhaust and urban ambient air particulate matter, and 2-nitrofluoranthene onto urban ambient air particulate matter. Coating efficiencies of about 400 μg/g particulate matter were routinely obtained on a single coating run, and up to 1200 μg/g (1200 ppm) were achieved after a second pass through the process. The coated particles were subsequently utilized in biological fate, distribution and metabolism studies     

Analysis of two models of (3D) Fresnel collectors operating in the fixed-aperture mode with a tracking absorber

In this paper, we study the reflection behavior of (3D) Fresnel collectors operating in the fixed-aperture mode with a tracking absorber. The aim of the study is to investigate the possibility of the use of this type of installation for applications in medium temperature processes (200–300°C). Two models of (3D) Fresnel concentrator are developed for this purpose. One is based on the approximation of the optical behavior of a parabolic concentrator, and the other on that of a spherical one. Via a computer simulation which includes ray-tracing, we evaluate the sensitivity of the geometric concentration ratio to concentrator design parameters, and the option of using curved versus flat elementary mirrors. The numerical results show that there is no large difference between the two models of Fresnel concentrator. For the spherical model, which seems to be slightly more suitable for this type of application, we propose a simple solution for the receiver displacement, which consists of a single-sided absorber moving tangentially to a sphere centered in the concentrator’s center.     

Natural Lignocellulosic Fibers as Engineering Materials—An Overview

Recent investigations on the tensile properties of natural cellulose-based fibers revealed an increasing potential as engineering materials. This is particularly the case of very thin fibers of some species such as sisal, ramie, and curaua. However, several other commonly used fibers such as flax, jute, hemp, coir, cotton, and bamboo as well as less known bagasse, piassava, sponge gourde, and buriti display tensile properties that could qualify them as engineering materials. An overview of the strength limits attained by these fibers is presented. Based on a tensile strength vs density chart, it is shown that natural fibers stand out as a relevant class of engineering materials.     

Personality development across the life span: Longitudinal analyses with a national sample from Germany.

Longitudinal data from a national sample of Germans (N = 20,434) were used to evaluate stability and change in the Big Five personality traits. Participants completed a brief measure of personality twice, 4 years apart. Structural equation modeling techniques were used to establish measurement invariance over time and across age groups. Substantive questions about differential (or rank-order) and mean-level stability and change were then evaluated. Results showed that differential stability was relatively strong among all age groups but that it increased among young adults, peaked in later life, and then declined among the oldest old. Patterns of mean-level change showed that Extraversion and Openness declined over the life span, whereas Agreeableness increased. Mean levels of Conscientiousness increased among young adults and then decreased among older adults. Trajectories for Neuroticism were relatively flat, with slight increases during middle age and a slight decline in late life. (PsycINFO Database Record (c) 2011 APA, all rights reserved)