Assessment of the mean-value of 17-hydroxypregnenolone in the umbilical blood of newborns by the exploratory analysis of biochemical data

The main aim of data analysis in biochemical metrology is the extraction of relevant information from biochemical data measurements. A system of extended exploratory data analysis (EDA) based on the concept of graphical tools for sample data summarization and exploration is proposed and the original EDA algorithm in S-Plus is available on the Internet at http://www.trilobyte.cz/EDA. To check basic assumptions about biochemical and medical data is to examine the independence of sample elements, sample normality and homogeneity. The exact assessment of the mean-value and the variance of steroid levels in controls is necessary for the correct assessment of the samples from patients. Data examination procedures are illustrated by a determination of the mean-value of 17-hydroxypregnenolone in the umbilical blood of newborns. For an asymmetric, strongly skewed sample distribution corrupted with outliers the best estimate of location seems to be the median. The Box–Cox transformation improves a sample symmetry. The proposed procedure gives reliable estimates of a mean-value for an asymmetric distribution of 17-hydroxypregnenolone when the arithmetic mean can not be used.     

Quasicrystal–crystal structural transformation in Al–5 wt.% Mn alloy

The atomic structure of Al–5 wt.%Mn (Al–5Mn) alloy, prepared by rapid solidification, and pre-annealed at 623 and 773 K for 5 and 1 h, respectively, were characterized by X-ray powder diffraction (XRD) and extended X-ray absorption fine structure (XAFS) techniques. The sample in as-quenched stage was found crystalline, consisting of metastable α-Al (Al–Mn solid solution) and icosahedral quasicrystalline I-Al₆Mn phases. Five hours annealing at 623 K proved thermal stability of both the phases. Pre-annealing at 773 K/1 h on the other hand leads to α-Al phase decomposition and structural transformation of metastable I-Al₆Mn to stable orthorhombic Al₆Mn phase. The EXAFS results indicate that Mn atoms are located preferably on the outer shell of icosahedrons. During the I-Al₆Mn→o-Al₆Mn transformation the total Al atoms coordinating one Mn were found to be constant (∼10). Based on the results, only distance/symmetry changes in atomic arrangement around Mn atoms were suggested.     

What stimulates teachers to integrate ICT in their pedagogical practices? The use of digital learning materials in education

The question ‘What stimulates teachers to integrate Information and Communication Technologies (ICTs) in their pedagogical practices?’ was addressed in the context of teachers’ usage of digital learning materials (DLMs). We adopted Fishbein’s Integrative Model of Behavior Prediction (IMBP), to investigate the various relationships between distal and proximal variables and intention. Mediation analysis revealed that the proximal variables attitude, subjective norm, and self-efficacy towards DLMs were significant predictors of teachers’ intention to use DLMs. The contribution of subjective norm, however, was modest. Attitude, subjective norm and self-efficacy mediated the effects of the following three distal variables on intention: previous use of DLMs, perceived knowledge and skills to use DLMs, and colleagues’ usage of DLMs. Persuasive communication and skills based training seem, therefore, appropriate interventions to promote a positive attitude towards DLMs and improve self-efficacy in using DLMs.     

Polymerization of monomers initiated by silyl centers in SiO deposits prepared by pulsed laser ablation

Deposits from silicon monoxide prepared by pulsed laser ablation were allowed to react with acrylic and vinyl monomers—styrene, methyl methacrylate and 1,2 ethylene glycol dimethacrylate. It was revealed by means of FTIR, electron paramagnetic resonance (EPR), and NMR spectroscopies that silyl ?Si· reacts with monomer molecules and initiates the consecutive polymerization. Crosslinking is proved by the occurrence of bending δ(? CH₂) absorption peak at about 750 cm^?1 in FTIR spectra. Because of very low concentration of the propagating radical for styrene we used a radical scavenger N‐phenyl‐t‐butylnitrone for trapping. The measured EPR parameters were compared with the calculated ones. In case of styrene, NMR analysis manifested the presence of Si? C bonds in SiC_xO_y (x + y = 2) units, which can be taken as direct evidence of the reaction between silyl centers and monomer molecules. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4488–4492, 2006     

Changes in precipitation and corrosion characteristics of 18/10Ti austenitic stainless steel exposed to prolonged annealing at 750–850 °C

This investigation deals with the analysis of intergranular acicular precipitations by X-ray diffraction techniques and SEM. Results obtained during analysing acicular precipitate in 18/10Ti steel, isothermally annealed at 750–850 °C, can be summarised as follows: Intergranular needles are constituted by a complex phosphide of M₂P type whose chemical composition can be written as (Ti,Cr,Fe,Ni)₂P. Crystal growth direction of intergranular acicular M₂P particles in austenite is 〈 100 〉_γ. The following orientation relationship was determined between the complex phosphide of M₂P type and austenite: . Corrosion testing in boiling 65% HNO₃ revealed that there was a relationship between the occurrence of acicular precipitate and a reduction in corrosion rate to a level below 0.5 g m^?2h^?1.     

Influence of hydrogen contamination by mercury on the lifetime of the PEM-type fuel cell

The subject of this study is the influence of traces of mercury present in the hydrogen originating e.g. from the amalgam technology of brine electrolysis on the lifetime of PEM-type fuel cell. Accelerated tests were used in order to record deterioration of laboratory fuel cells’ performance. The power output decrease observed was only partly reversible. As was proven by XPS spectroscopy, the cell performance deterioration originates from the interaction between mercury and the platinum catalyst. The lifetime of the fuel cell was assessed on the basis of the experiments performed as 7000 h for an average mercury concentration in the hydrogen of 10 μg N m⁻³. This is a sufficient value to permit utilization of the hydrogen from this source as a fuel for the fuel cell. It should be kept in the mind, however, that this value was obtained on the basis of the accelerated durability tests.     

Attitude, knowledge, and skill competencies for practice in professional geropsychology: Implications for training and building a geropsychology workforce.

Professional geropsychology is a growing area of practice and training. To meet the mental health needs of an aging population, increasing numbers of psychologists need to develop competence to work with older adults, their families, and related care systems. The Pikes Peak model for geropsychology training (Knight, Karel, Hinrichsen, Qualls, & Duffy, 2009) delineates attitude, knowledge, and skill competencies for professional geropsychology practice and makes recommendations for training. In this paper, we define and illustrate the Pikes Peak geropsychology practice competencies through a case example. In the case, an older man with complex needs seeks care through a generalist psychologist in an outpatient setting. The attitudes, knowledge, and skills that the psychologist needs to consider, and implications for training, are reviewed. Training recommendations and resources are provided, with a focus on the training needs of psychologists who wish to expand their practices to include older adults. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Crystallization of Pd40Cu30Ni10P20 bulk metallic glass with and without pressure

The glass-transition behavior of Pd40Cu30Ni10P20 bulk metallic glass was investigated by differential scanning calorimetry （DSC） and X-ray powder diffraction （XRD）. The effect of pressure on the crystallization behavior of Pd40Cu30Ni10P20 bulk glass was studied by in situ high-pressure and high-temperature X-ray powder diffraction using synchrotron radiation. Phase analyses show at least six crystalline phases in the crystallized sample, namely, monoclinic, tetragonal CuaPd-like, rhombohedral, fcc-Ni2Pd2P, fcc-（Ni, Pd） solid solution, and body-centered tetragonal （bct） NiaP-like phases. The onset crystallization temperature increases with pressure having a slope of 1 1 K/GPa in the range of 0 to 4 GPa. The results are attributed to the competing process between the thermodynamic potential barrier and the diffusion activation energy under pressure.     

Silica Nanoparticles Inhibit Responses to ATP in Human Airway Epithelial 16HBE Cells

Because of their low cost and easy production, silica nanoparticles (SiNPs) are widely used in multiple manufacturing applications as anti-caking, densifying and hydrophobic agents. However, this has increased the exposure levels of the general population and has raised concerns about the toxicity of this nanomaterial. SiNPs affect the function of the airway epithelium, but the biochemical pathways targeted by these particles remain largely unknown. Here we investigated the effects of SiNPs on the responses of 16HBE14o- cultured human bronchial epithelial (16HBE) cells to the damage-associated molecular pattern ATP, using fluorometric measurements of intracellular Ca²⁺ concentration. Upon stimulation with extracellular ATP, these cells displayed a concentration-dependent increase in intracellular Ca²⁺, which was mediated by release from intracellular stores. SiNPs inhibited the Ca²⁺ responses to ATP within minutes of application and at low micromolar concentrations, which are significantly faster and more potent than those previously reported for the induction of cellular toxicity and pro-inflammatory responses. SiNPs-induced inhibition is independent from the increase in intracellular Ca²⁺ they produce, is largely irreversible and occurs via a non-competitive mechanism. These findings suggest that SiNPs reduce the ability of airway epithelial cells to mount ATP-dependent protective responses.