Monitoring of tissue thermal modification with a bundle-based full-field speckle analyzer

Speckle-contrast monitoring of laser-mediated tissue modification is examined for the specific case of delivery of speckle-modulated light from the tissue to detector (CCD camera) with a fiber-optic element (bundle). The influence of the transfer properties of a bundle-based optical system on the decorrelation rate of detected dynamic speckles is analyzed. Compared with the widely used method on the base of speckle-contrast analysis in the image plane, the considered technique is characterized by a more pronounced correlation between variations of the contrast of time-averaged speckle patterns and changes in the temperature of the modified tissue. The possibility of characterization of the modification kinetics (in particular, by the evaluation of the characteristic activation energy) using the developed speckle technique is demonstrated.     

Spectroscopic characterization of the electrochemical functionalization of single-walled carbon nanotubes in aqueous and organic media

An electrochemical method of functionalizing of single-walled carbon nanotubes (SWCNTs) in aqueous and organic electrolytes by the electrolysis of bromide solutions at anodic potentials is proposed. Cyclic voltammeter studies point to a substantial increase in the SWCNTs electrode capacitance after its electrochemical treatment, which is associated with an increase in the electrode working surface accessible to solution. This effect is attributed to the formation of functional groups on the SWCNTs surface. This conclusion is confirmed by analyzing the electrochemically processed SWCNTs by the methods Raman, UV–Vis–Nir and X-ray photoelectron spectroscopies. The electrolysis of potassium bromide solutions in both aqueous and nonaqueous media is shown to produce functional groups containing oxygen and, to a smaller extent, bromine. The dependence of the degree of SWCNT functionalization (the number of chemically bound foreign atoms per the number of carbon atoms) on the electrolyte nature is observed experimentally. The degree of functionalization reached in dimethyl sulfoxide is comparable with that of the original SWCNTs, whereas in aqueous solutions, the high density of functional groups (one O atom per 3–4 C atoms) is observed.     

Molecular epidemiology of microorganisms isolated from food workers and enteral feeding of public hospitals

This study aimed to compare strains of Staphylococcus aureus and E. coli isolated from food workers and enteral diet samples obtained from 2 public hospitals (H1/H2) in Goiania, Goias, Brazil, by the means of antibiogram and pulsed field gel electrophoresis (PFGE). In the H1, strains of S. aureus were present in 2 enteral diet samples and in 13 food worker swabs. Strains of E. coli were found in an enteral diet sample from H1 and in 2 enteral diet samples from H2 and in 6 food worker swabs in the H1 and in 12 food worker swabs from H2. According to the antibiogram, the 6 susceptibility profiles (A to F) of 15 S. aureus strains colonizing personnel and enteral feeding did not allow the identification of the probable source of diet contamination. All 20 E. coli strains isolated from the H1 and H2 were grouped in 4 phenotypic profiles (A to D). The phenotypes A (H1) and C (H2) showed the same profile for microorganisms isolated from handlers and diets, suggesting more phenotypic similarity among these samples. PFGE genotyping showed that S. aureus isolates from diets were related to a single strain isolated from a food worker suggesting that in this case the reason for the diet contamination may be a result of food handling. The food worker appears to be the most probable source of E. coli contamination for enteral feeding from H2. This fact emphasizes on the food workers as a risk of bacterial transmission for the diets and that the diet chain production must be controlled. PRACTICAL APPLICATION: The study emphasizes the importance of monitoring the enteral diet microbiological quality and the factors associated to its contamination. The study highlights the use of molecular biology as an instrument to correlate strains to determine the origin of the final product contamination.     

Hydrogen production by Escherichia coli depends on glucose concentration and its combination with glycerol at different pHs

Escherichia coli produces molecular hydrogen (H₂) during glucose or mixed carbon (glucose and glycerol) fermentation. Dependence of H₂ production rate (VH₂)$\left(V_{{\text{H}}_2}\right)$ on glucose at different pHs was studied in a concentration dependent manner. During growth of wild-type on glucose, increasing glucose concentration from 0.05% to 0.2% resulted in the marked inhibition of VH₂$V_{{\text{H}}_2}$. Inhibitory effect of glucose was shown at pH 7.5 and 6.5 but not pH 5.5. However, glycerol added in the growth medium with 0.1% glucose significantly increased VH₂$V_{{\text{H}}_2}$ but different effects at different pHs were established upon glucose or glycerol assays. The results indicate that H₂ production is inhibited by glucose in a concentration dependent manner during glucose fermentation but glucose in combination with glycerol might enhance H₂ production during mixed carbon fermentation.     

Synthesis of γ-TiAl by thermal explosion + compaction route: Effect of process parameters and post-combustion treatment on product microstructure

In previous works, we suggested a method for the production of γ-TiAl alloys. This method consists of three main stages: thermal explosion + compaction, thermal treatment, and hot isostatic pressing (HIP). This processing route shows encouraging results in density, microstructure, and mechanical properties. In this work, the effect of some parameters of the thermal explosion + compaction process on the product microstructure was studied. Some interesting results were found and, overall, the significance of a load application schedule was established. Moreover, the combination of the post-combustion processes was studied. In other words, HIP and thermal treatment were carried out in one stage. The most important parameters of the cycles were optimized in order to obtain a fully lamellar microstructure.     

ToolDAy: a tool for domain analysis

Domain analysis is the process of identifying and documenting common and variable characteristics of systems in a specific domain. This process is a large and complex one, involving many interrelated activities, making it essential to have a tool support for aiding the process. We present a domain analysis tool called ToolDAy that has the purpose of making the process semi-automatic. The requirements definition presented were based on the results of a systematic review that analyzed several existing tools. Furthermore, this article describes the tool architecture, implementation and its evaluations (two as a controlled experiment and one as an industrial case study) with three different domains. The results of these evaluations indicate that the tool can aid the domain analyst to achieve systematic reuse in an effective way.     

Comprehensive Study of the Effect of Plasma Stream on Heat-Resistant Materials

An experimental set-up with a unified system of synchronized control signals was constructed to study the interaction of high-enthalpy plasma jet with the surface of heat-resistant materials. The analysis of air–plasma stream interaction with technical (isotropic) graphite is performed. The air–plasma jet has a temperature of 7000–8000 K in the interaction zone, this interaction is accompanied by destruction of the graphite material and lasts for 100–200 s. Using methods like two-positioning visualization, micropyrometry and spectroscopy the following data are obtained: temperature fields on the graphite sample’s surface and their temporal and spatial changes, dynamics of the sample’s mass loss rate, changes in the parameters (temperature and concentration of electrons, heavy particles temperature) of the incoming plasma stream.     

MMPI-A patterns of male juvenile delinquents.

The usefulness of the MMPI-Adolescent (MMPI-A [J. N. Butcher et al, 1992]) was examined for 162 delinquent boys in a state training school. Their base rates, patterns, and configurations on all the MMPI-A scales and subscales were determined and compared with those of the 805 nondelinquent male adolescents in the MMPI-A standardization sample and with the original MMPI patterns of 7,783 delinquents identified in a literature review. The most prominent clinical scales were 4, 6, and 9, and 49/94 was the most frequent 2-point code. The study confirmed 14 of 18 hypotheses for mean differences on the 38 MMPI-A validity, clinical, supplementary, and content scales, and also found significant mean differences on 33 of the other 51 MMPI-A scales and subscales, 13 of which were large enough to be clinically meaningful. Most of the MMPI-A patterns and configurations were consistent with the literature on male juvenile delinquents. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Computer Modeling of the Metrological Characteristics of Standard Measuring Instruments

The possibilities are considered of the computer modeling of the metrological characteristics of a standard instrument for measuring spectral noise power density utilizing low-temperature waveguide noise generators operating in the millimeter wavelength range.