Homology modelling of the human eukaryotic initiation factor 5A (eIF-5A)

Homology modelling of the human eIF-5A protein has been performedby using a multiple predictions strategy. As the sequence identitybetween the target and the template proteins is nearly 30%,which is lower than the commonly used threshold to apply withconfidence the homology modelling method, we developed a specificpredictive scheme by combining different sequence analyses andpredictions, as well as model validation by comparison to structuralexperimental information. The target sequence has been usedto find homologues within sequence databases and a multiplealignment has been created. Secondary structure for each singleprotein has been predicted and compared on the basis of themultiple sequence alignment, in order to evaluate and adjustcarefully any gap. Therefore, comparative modelling has beenapplied to create the model of the protein on the basis of theoptimized sequence alignment. The quality of the model has beenchecked by computational methods and the structural featureshave been compared to experimental information, giving us agood validation of the reliability of the model and its correspondenceto the protein structure in solution. Last, the model was depositedin the Protein Data Bank to be accessible for studies on thestructure–function relationships of the human eIF-5A.     

Studies on near infrared optical absorption, Raman scattering, and corresponding thermal properties of single- and double-walled carbon nanotubes for possible cancer targeting and laser-based ablation

We report the photo-thermal properties of single and double wall carbon nanotubes (CNT) dispersed in various solvents with different concentrations when exposed to near infrared nm laser irradiations. All these studies were correlated to the dispersivity of CNT in various solvents. The observed temperature increase of the various nanotube solutions was found to be determined by the concentration of the optically active nanotubes, as determined from their Raman scattering spectra, which are resonant in the spectral range of the laser excitation. Such findings could significantly improve the understanding of the optically active CNT species, their overall laser induced-heating levels, and thus reducing the amount of the CNT required for bio-medical photothermal applications to limit the possible undesired cytotoxic effects that occur at high nanotube concentrations. Our studies open up the possibility of using selective species of CNT as effective low-toxic photo thermal agents for cancer targeting and ablation.     

Defined Chitosan-based networks by C-6-Azide–alkyne “click” reaction

Chitosan was converted to its –NH₂-protected derivative by reacting with phthalic anhydride and then selectively functionalized with an azido group in C-6 position. Two different procedures were employed. The first was a “one-pot” procedure and the second was a two steps reaction through the tosylated intermediate. Both methods resulted in an effective functionalization of chitosan with azido groups. For the two before mentioned procedures, the functionalization degree was estimated by elemental analysis as number of azido groups per pyranoside ring and was 0.28 mol/mol and 0.26 mol/mol, respectively. The azido-functionalized derivatives underwent further modification by Cu(I) catalyzed dipolar cycloaddition with mono- or di-alkynes. The reaction with phenylacetylene produced soluble derivatives that were fully characterized at molecular level by FT-IR and NMR spectroscopies, elemental analysis and size exclusion chromatography (SEC). Crosslinked derivatives were obtained by reactions with 1,7-octadiyne or 1,4-diethynylbenzene and subsequently deprotected to restore the free amino groups. These last systems showed selective swellability in acid medium.     

Improvements in vascular health by a low-fat diet,but not a high-fat diet,are mediated by changes in adipocyte biology

Background  

Low-fat (LF) and high-fat (HF) weight loss diets improve brachial artery flow-mediated dilation (FMD) in obese individuals, although results are conflicting. Moreover, the role that adipose tissue plays in mediating these diet-related effects are unknown.     

Removal of viable and inactivated Cryptosporidium by dual- and tri-media filtration

The limited efficacy of disinfectants, other than ultraviolet irradiation and ozonation, as a barrier against Cryptosporidium parvum in drinking water treatment has underscored the increased importance of oocyst removal by filtration. Currently, no reliable surrogates have been identified for C. parvum removal by filtration. As a result, evaluations of the Cryptosporidium removal by treatment operations have been performed using oocysts. It has typically been assumed that chemically inactivated oocysts are suitable surrogates for viable oocysts. Measurements of electrophoretic mobility, however, have shown that chemical inactivation changes the surface charge of Cryptosporidium oocysts. The present bench-scale research indicated that formalin-inactivated oocysts are reliable surrogates for viable oocysts during both stable filter operation and periods where filtration processes are challenged, such as coagulation failure. This finding is important because of the practical difficulties associated with using viable oocysts in filtration investigations. Poor coagulation conditions severely compromised removal of viable and inactivated oocysts by dual- and tri-media filters compared to stable operating conditions and filter ripening, emphasizing the importance of optimized chemical pre-treatment (coagulation) for the successful removal of oocysts during filtration. The treatment optimization experiments also indicated that tri-media filters offered only marginally higher oocyst removals than dual-media filters.     

Factorial validity and consistency of the MBI-GS across occupational groups in Norway.

The present study tested the factorial validity of the Maslach Burnout Inventory-General Survey (MBI-GS) among 694 participants from 4 different occupational groups. Confirmatory factor analyses of the total sample, as well as multigroup analyses and analyses of each of the 4 occupational groups separately, indicated that the original 3-factor model of the MBI-GS provided a good fit to the data. Internal consistencies of the subscales of the MBI-GS were acceptable, and test-retest reliability indicated relative stability of scores over a 6-month interval. These results indicate that the proposed 3-factor structure of the MBI-GS, based on 16 items, can be replicated in the total sample as well as across different occupational groups in Norway. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Method to Determine the Number of Bacterial Spores Within Aerosol Particles

We describe methodology to reveal the number of microbial spores within aerosol particles. The procedure involves visualization under differential- interference-contrast microscopy enhanced by high-resolution photography and further analysis by computer-assisted imaging. The method was used to analyze spore of Bacillus globigii in aerosols generated by a small (pressured metered-dose inhaler type) generator. Particles consisting in 1 or 2 spores accounted for 85% of all generated particles. This percentage rose to 91% when the same aerosol was collected on an Andersen cascade impactor that collected particles larger than 0.65 μm and was even higher (96%) when particles larger than 3.3 μm were also eliminated. These results demonstrate that the imaging analysis of aerosol particles collected on glass slides is sensitive to even relatively small changes in aerosol particle composition. The accuracy of the enhanced microscopic method described herein (differences between visual and computer analysis were approximately 3% of the total particle counts) seems adequate to determine the spore composition of aerosols of interest in biodefense.