Ultrastructural study of mouse adipose‐derived stromal cells induced towards osteogenic direction

We investigated the ultrastructural characteristics of mouse adipose‐derived stem/stromal cells (ASCs) induced towards osteogenic lineage. ASCs were isolated from adipose tissue of FVB‐Cg‐Tg(GFPU)5Nagy/J mice and expanded in monolayer culture. Flow cytometry, histochemical staining, and electron microscopy techniques were used to characterize the ASCs with respect to their ability for osteogenic differentiation capacity. Immunophenotypically, ASCs were characterized by high expression of the CD44 and CD90 markers, while the relative content of cells expressing CD45, CD34 and CD117 markers was <2%. In assays of differentiation, the positive response to osteogenic differentiation factors was observed and characterized by deposition of calcium in the extracellular matrix and alkaline phosphatase production. Electron microscopy analysis revealed that undifferentiated ASCs had a rough endoplasmic reticulum with dilated cisterns and elongated mitochondria. At the end of the osteogenic differentiation, the ASCs transformed from their original fibroblast‐like appearance to having a polygonal osteoblast‐like morphology. Ultrastructurally, these cells were characterized by large euchromatic nucleus and numerous cytoplasm containing elongated mitochondria, a very prominent rough endoplasmic reticulum, Golgi apparatus and intermediate filament bundles. Extracellular matrix vesicles of variable size similar to the calcification nodules were observed among collagen fibrils. Our data provide the ultrastructural basis for further studies on the cellular mechanisms involved in osteogenic differentiation of mouse adipose‐derived stem/stromal cells. Microsc. Res. Tech. 79:557–564, 2016. © 2016 Wiley Periodicals, Inc.     

Fabrication of new antifungal polyamide‐12 material

Water‐resistant polymeric biocide poly(hexamethylene guanidine) dodecylbenzenesulfonate (PHMG‐DBS) was synthesized by anion metathesis between poly(hexamethylene guanidine) hydrochloride and sodium dodecylbenzenesulfonate and subsequently characterized using elemental analysis, Raman spectroscopy and thermogravimetric analysis. It is found that PHMG‐DBS is thermally stable to at least 350 °C, which makes it suitable for melt blending with polyamide (PA) resins. An antifungal PA‐12 composition was prepared by compression moulding of PA‐12 and PHMG‐DBS powder mixture at 240 °C. The characteristics of the prepared films were investigated: surface roughness and hydrophobicity using atomic force microscopy and contact angle measurements, respectively. No significant change in the material characteristics is observed compared to pure PA‐12 films. PA‐12 films containing 2 wt% of the PHMG‐DBS biocide are found to be highly resistant against Trychophyton mentagrophytes fungus. Copyright © 2012 Society of Chemical Industry     

XPS Structural Studies of Nano-composite Non-platinum Electrocatalysts for Polymer Electrolyte Fuel Cells

The chemical structure of non-platinum electrocatalysts obtained from cobalt porphyrins (CoTMPP or CoTPP) by pyrolysis is investigated by X-ray Photoelectron Spectroscopy (XPS). The catalysts represent highly dispersed, self-supported nano-composites that demonstrate electrocatalytic performance for oxygen reduction and practically no activity in methanol electro-oxidation. High-resolution Co2p, C1s, N1s and O1s XPS spectra acquired from precursors and electrocatalysts pyrolyzed at various experimental conditions were curve-fit using (a) individual peaks of constrained width and shape as well as (b) experimentally obtained photopeaks from the precursor with additional peaks required for a complete curve fit. Principal Component Analysis (PCA) applied to quantitative results from the curve-fits of both types of spectra facilitates visualization and identification of the chemical species that are formed or destroyed, and simplifies evaluation of critical correlations. As a result of these studies it is established that the catalyst is a nano-composite of highly dispersed pyropolymer with some remaining N _x -centers inserted into a graphite-like matrix. Approximately 50% of the metal is distributed as Co²⁺, associated with N₄-centers. The remaining cobalt is present in crystallites of metallic Co. A thin layer of CoO coats these metallic cobalt phases. The developed methodology, described herein, combines model curve-fits and principal component analysis (PCA), resulting in a quantitative and unambiguous understanding of the chemical composition and structure of complex electrocatalysts.     

Continuous flow removal of acid fuchsine by dielectric barrier discharge plasma water bed enhanced by activated carbon adsorption

Continuous processes which allow for large amount of wastewater to be treated to meet drainage standards while reducing treatment time and energy consumption are urgently needed. In this study, a dielectric barrier discharge plasma water bed system was designed and then coupled with granular activated carbon (GAC) adsorption to rapidly remove acid fuchsine (AF) with high efficiency. Effects of feeding gases, treatment time and initial concentration of AF on removal efficiency were investigated. Results showed that compared to the N2 and air plasmas treatments, O2 plasma processing was most effective for AF degradation due to the strong oxidation ability of generated activated species, especially the OH radicals. The addition of GAC significantly enhanced the removal efficiency of AF in aqueous solution and shorten the required time by 50%. The effect was attributed to the ability of porous carbon to trap and concentrate the dye, increasing the time dye molecules were exposed to the plasma discharge zone, and to enhance the production of OH radicals on/in GAC to boost the degradation of dyes by plasma as well as in situ regenerate the exhausted GAC. The study offers a new opportunity for continuous effective remediation of wastewater contaminated with organic dyes using plasma technologies.     

Interfacial phase formation of Al-Cu bimetal by solid-liquid casting method

The solid-liquid method was used to prepare the continuous casting of copper cladding aluminium by liquid aluminum alloy and solid copper, and the interfacial phase formation of Al-Cu bimetal at different pouring temperatures (700, 750, 800 ℃) was investigated by means of metallograph, scanning electron microscopy (SEM) and energy dispersive spectrometry (EDS) methods. The results showed that the pouring temperature of aluminum melt had an important influence on the element diffusion of Cu from the solid Cu to Al alloy melt and the reactions between Al and Cu, as well as the morphology of the Al-Cu interface. When the pouring temperature was 800 oC, there were abundant Al-Cu intermetallic compounds (IMCs) near the interface. However, a lower pouring temperature (700 ℃) resulted in the formation of cavities which was detrimental to the bonding and mechanical properties. Under the conditions in this study, the good metallurgical bonding of Al-Cu was achieved at a pouring temperature of 750 ℃.     

Can alexithymia be assessed in adolescents? Psychometric properties of the 20-item Toronto Alexithymia Scale in younger, middle, and older adolescents.

The 20-item Toronto Alexithymia Scale (TAS-20; Bagby, Parker, & Taylor, 1994; Bagby, Taylor, & Parker, 1994) is the most widely used self-report measure of the alexithymia construct. The TAS-20 comprises 3 factors that assess difficulty identifying feelings, difficulty describing feelings, and externally oriented thinking. Although the instrument is being increasingly used with adolescent respondents, the psychometric properties of the TAS-20 have not been systematically evaluated in preadult populations. In the present study, we examined measurement invariance of the factor structure, internal reliability, and mean levels of responses on the TAS-20 in groups of younger adolescents (aged 13–14 years), middle adolescents (aged 15–16 years), and older adolescents (aged 17–18 years), as well as in a comparison group of young adults (aged 19–21 years). Formal readability analysis of the TAS-20 assessment was also conducted. Results revealed systematic age differences in the factor structure and psychometric properties of the TAS-20, with the quality of measurement progressively deteriorating with younger age. Much of this effect could be attributed to the reading difficulty of the scale. The use of the TAS-20 with teenage respondents is not recommended without appropriate adaptation and further psychometric validation. Several adaptation strategies are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Growth of phthalocyanine doped and undoped nanotubes using mild synthesis conditions for development of novel oxygen reduction catalysts

Precious metal alloys have been the predominant electrocatalyst used for oxygen reduction in fuel cells since the 1960s. Although performance of these catalysts is high, they do have drawbacks. The two main problems with precious metal alloys are catalyst passivation and cost. This is why new novel catalysts are being developed and employed for oxygen reduction. This paper details the low temperature solvothermal synthesis and characterization of carbon nanotubes that have been doped with both iron and cobalt centered phthalocyanine. The synthesis is a novel low-temperature, supercritical solvent synthesis that reduces halocarbons to form a metal chloride byproduct and carbon nanotubes. Perchlorinated phthalocyanine was added to the nanotube synthesis to incorporate the phthalocyanine structure into the graphene sheets of the nanotubes to produce doped nanotubes that have the catalytic oxygen reduction capabilities of the metallo-phthalocyanine and the advantageous material qualities of carbon nanotubes. The cobalt phthalocyanine doped carbon nanotubes showed a half wave oxygen reduction potential of -0.050 ± 0.005 V vs Hg\HgO, in comparison to platinum's half wave oxygen reduction potential of -0.197 ± 0.002 V vs Hg\HgO.     

Stimulation of tumor-specific immunity using tumor cell plasma membrane antigen

An improved methodology is described for the separation of yolk IgG into subpopulations using immobilized metal ion (Fe3+) affinity chromatography. The yolk IgG was first extracted using a prechilled, pre-acidified method. After extraction, the yolk IgG was then fractionated using an Fe3+ column. Using an ascending pH gradient, four IgG containing peaks were well resolved based upon the elution pH, specific activity and the relative avidity index.     

Automatic ectopic beat elimination in short-term heart rate variability measurement

Our studies deal with fully automatic measurement of heart rate variability (HRV) in short term electrocardiograms. Presently, all existing HRV analysis programs require user intervention for ectopic beat identification, especially of supraventricular ectopic beats (SVE). This makes the HRV measurement in large, e.g. epidemiological studies problematic. In this paper, we present a fully automatic algorithm for the discrimination of the ventricular (VE) and SVE ectopic beats from the normal QRS complexes suited for a reliable HRV analysis. The QRS identification is based on the template matching method. The ectopic beats are identified based on several morphological and timing properties of the electrocardiogram (ECG) signal. The method incorporates several approaches and makes HRV analysis of large numbers of electrocardiograms feasible. It uses the template matching for the basic morphology check of the QRS complex and the P-wave, the timing information to avoid unnecessary ectopic beat checks and to adjust thresholds and it also looks for a special QRS morphology, which is common in VEs. We used a testing set of 69 electrocardiograms selected from a large number of recordings. The selected ECGs contained abnormalities including ectopic beats, right branch bundle block, respiratory arrhythmia, blocked atrial extrasystole, high amplitude and wide T-waves. The evaluation of our method showed a specificity of 0.99, supraventricular ectopic beat sensitivity of 0.99 and ventricular ectopic beat sensitivity of 0.98.     

Printing Inks＇ Characteristics

Hybrid inks are often used for the advertising products because a variety of effects can serve as an added value. Much attention is paid to the inks application settings, using the hybrid inks at the hi-tech offset equipment and color features of images. The thorough research of the different printing settings with the use of modern inks and efficient equipment, is an urgent problem. Work reveals some new facts about characteristics for printability such as emulsification and influences of ink＇s additives on color characteristics of imprints. The experimental inks were developed to define the technological settings of offset printing. The result of research showed that conventional inks have the considerably high degree of emulsification comparing to experimental hybrid inks. Also it was discovered that the UV components influence the emulsification. An optimal water-ink balance and stable printing process can be achieved with adding of 2%-10% of the UV-component to the hybrid inks. Inks application and drying settings as well as color features of the imprints are analyzed in the context of offset printing.