Subacute proteome changes following traumatic injury of the developing brain: Implications for a dysregulation of neuronal migration and neurite arborization

Traumatic brain injury (TBI) is a major cause of morbidity and mortality among children and adolescents. To gain insight into developmental events influenced by TBI, we analyzed subacute mouse brain proteome changes in a percussion head trauma model at P7 ipsi- and contralateral to the site of injury. The comparison of brain proteomes of trauma mice and controls revealed reproducible changes in the intensity of 28 proteins (30 protein spots) in response to trauma. The changes detected suggest that TBI leads to apoptosis, inflammation, and oxidative stress. These changes were consistent with our results of histological and biochemical evaluation of the brains which revealed widespread apoptotic neurodegeneration, microglia activation, and increased levels of protein carbonyls. Furthermore, we detected changes in proteins involved in neuronal migration as well as axonal and dendritic growth and guidance, suggesting interference of trauma with these developmental events.     

Optical properties of GaAs0.9-xNxSb0.1 alloy films studied by spectroscopic ellipsometry

Spectroscopic ellipsometry from 0.73 to 4.75 eV was used to study the optical properties of epitaxial GaAs_0.9-xN_xSb_0.1 layers with x = 0.00, 0.65, 1.06, 1.45 and 1.90%. The ellipsometric experimental spectra were fitted using a multilayer model employing the model dielectric function to describe the GaAs_0.9-xN_xSb_0.1 optical response. We have identified the Γ-point E₀, E₊, and E^# transitions of GaAs_0.9-xN_xSb_0.1 and have determined the effect of nitrogen on the respective transition energies. We have demonstrated that a lower N content can provide an equal E₊-E₀ energy splitting for GaAs_0.9-xN_xSb_0.1 with respect to GaAs_1-xN_x.     

Anti-Idiotype scFv Localizes an Autoepitope in the Globular Domain of C1q

We addressed the issue of C1q autoantigenicity by studying the structural features of the autoepitopes recognized by the polyclonal anti-C1q antibodies present in Lupus Nephritis (LN) sera. We used six fractions of anti-C1q as antigens and selected anti-idiotypic scFv antibodies from the phage library “Griffin.1”. The monoclonal scFv A1 was the most potent inhibitor of the recognition of C1q and its fragments ghA, ghB and ghC, comprising the globular domain gC1q, by the lupus autoantibodies. It was sequenced and in silico folded by molecular dynamics into a 3D structure. The generated 3D model of A1 elucidated CDR similarity to the apical region of gC1q, thus mapping indirectly for the first time a globular autoepitope of C1q. The V_H CDR2 of A1 mimicked the ghA sequence GSEAD suggested as a cross-epitope between anti-DNA and anti-C1q antibodies. Other potential inhibitors of the recognition of C1q by the LN autoantibodies among the selected recombinant antibodies were the monoclonal scFv F6, F9 and A12.     

Switching azonaphthols containing a side chain with limited flexibility. Part 1. Synthesis and tautomeric properties

A series of azo dyes, possessing amide fragments with restricted flexibility tethered to 4-(phenyldiazenyl)naphthalen-1-ol, was obtained from 1-hydroxy-2-naphthoic acid by subsequent conversion to amides and diazo coupling. It was shown that the position of the tautomeric equilibrium in solution strongly depends on the solvent in both UV and NMR concentration scale. The compounds exist as pure enol forms in chloroform and hydrocarbons, while in polar solvents (acetone, acetonitrile, alcohols) a tautomeric mixture is observed. According to the quantum-chemical calculations the aggregation of the keto tautomer is the possible reason for this shift in the position of the tautomeric equilibrium. To support the theoretical predictions, it was found that from acetone the keto form crystallizes as a dimer with hydrogen bonding between N₁-H in the one molecule and amide CO in the other forming a three-dimensional structure. The importance of the side-chain nitrogen atom on the dimer formation was confirmed by solution and solid state study of 4-(phenyldiazenyl)-2-acetylnaphthalen-1-ol. The results indicate that the new azo-dyes obtained could be suitable candidates for switching and sensing applications in non-polar solvents.     

Aging effects on gasoline-ethanol blend properties and composition

Blends of 75% gasoline and 25% ethanol (E25) are unique fuels used in Brazil. The natural E25 oxidation process due to aging under atmospheric conditions has been investigated. To evaluate aging effects on the properties of commercially available fuel blends, two samples of regular E25, one sample of regular E25 with additives, and one sample of high octane E25 were tested. The samples were analyzed as new and in aging periods of 30 and 180 days. Fuel density, distillation temperatures T₁₀, T₅₀ and T₉₀, motor and research octane number, as well as concentrations of ethanol, oxygen, olefins, total aromatics, benzene and saturates were evaluated. It was observed an increase of fuel density, distillation temperatures, aromatics and oxygen concentration, and a decrease of the concentration of olefins with aging. The results indicate that the use of aged fuel in automotive engines may increase fuel consumption, carbon deposits formation, carbon monoxide and hydrocarbon emissions.     

Hydride vapor-phase epitaxial GaN thick films for quasi-substrate applications: Strain distribution and wafer bending

The strain distribution in thick hydride vapor-phase epitaxial (HVPE)-GaN layers grown on metal-organic vapor-phase epitaxial GaN templates was studied by means of photoluminescence, x-ray mapping, and lattice parameter analysis. A variable temperature x-ray study of the film curvature was used for verification of the strain type. The relation between the strain inhomogeneity and the wafer bending in films residing on sapphire and freestanding on the thickness of the layer and the substrate is analyzed. Possibilities to improve the uniformity of the film characteristics and to reduce the bending of the HVPE-GaN films are discussed.     

Tailoring Structure,Composition, and Energy Storage Properties of MXenes from Selective Etching of In‐Plane,Chemically Ordered MAX Phases

The exploration of 2D solids is one of our time's generators of materials discoveries. A recent addition to the 2D world is MXenes that possses a rich chemistry due to the large parent family of MAX phases. Recently, a new type of atomic laminated phases (coined i‐MAX) is reported, in which two different transition metal atoms are ordered in the basal planes. Herein, these i‐MAX phases are used in a new route for tailoriong the MXene structure and composition. By employing different etching protocols to the parent i‐MAX phase (Mo_2/3Y_1/3)₂AlC, the resulting MXene can be either: i) (Mo_2/3Y_1/3)₂C with in‐plane elemental order through selective removal of Al atoms or ii) Mo_1.33C with ordered vacancies through selective removal of both Al and Y atoms. When (Mo_2/3Y_1/3)₂C (ideal stoichiometry) is used as an electrode in a supercapacitor—with KOH electrolyte—a volumetric capacitance exceeding 1500 F cm^?3 is obtained, which is 40% higher than that of its Mo_1.33C counterpart. With H₂SO₄, the trend is reversed, with the latter exhibiting the higher capacitance (≈1200 F cm^?3). This additional ability for structural tailoring will indubitably prove to be a powerful tool in property‐tailoring of 2D materials, as exemplified here for supercapacitors.     

2D Transition Metal Carbides (MXenes) for Carbon Capture

Global warming caused by burning of fossil fuels is indisputably one of mankind's greatest challenges in the 21st century. To reduce the ever‐increasing CO₂ emissions released into the atmosphere, dry solid adsorbents with large surface‐to‐volume ratio such as carbonaceous materials, zeolites, and metal–organic frameworks have emerged as promising material candidates for capturing CO₂. However, challenges remain because of limited CO₂/N₂ selectivity and long‐term stability. The effective adsorption of CO₂ gas (≈12 mol kg^?1) on individual sheets of 2D transition metal carbides (referred to as MXenes) is reported here. It is shown that exposure to N₂ gas results in no adsorption, consistent with first‐principles calculations. The adsorption efficiency combined with the CO₂/N₂ selectivity, together with a chemical and thermal stability, identifies the archetype Ti₃C₂ MXene as a new material for carbon capture (CC) applications.     

Use of a Reducing Melt to Treat the Surface of High-Alloy Steels and Alloys

The technological advantages of reducing melts are readily apparent. Such melts can dissolve certain acidic oxides (Si, Mo, W, Ti), and they reduce not only the oxides dissolved in the melt (ferrates, ferrites), but also those on the surface of the steel. A reaction involving sodium hydride completely reduces oxides of iron, nickel, cobalt, and copper and partially reduces oxides of chromium, manganese, vanadium, and titanium. Pickling schemes that have been developed reduce acid consumption and metal loss during pickling and prevent over-pickling of the surface. The technology as a whole is particularly suited for metallurgical plants that produce a wide range of steels. __________ Translated from Metallurg, No. 5, pp. 63–64, May, 2005.     

Physical-chemical properties of waste cooking oil biodiesel and castor oil biodiesel blends

This work presents the physical-chemical properties of fuel blends of waste cooking oil biodiesel or castor oil biodiesel with diesel oil. The properties evaluated were fuel density, kinematic viscosity, cetane index, distillation temperatures, and sulfur content, measured according to standard test methods. The results were analyzed based on present specifications for biodiesel fuel in Brazil, Europe, and USA. Fuel density and viscosity were increased with increasing biodiesel concentration, while fuel sulfur content was reduced. Cetane index is decreased with high biodiesel content in diesel oil. The biodiesel blends distillation temperatures T₁₀ and T₅₀ are higher than those of diesel oil, while the distillation temperature T₉₀ is lower. A brief discussion on the possible effects of fuel property variation with biodiesel concentration on engine performance and exhaust emissions is presented. The maximum biodiesel concentration in diesel oil that meets the required characteristics for internal combustion engine application is evaluated, based on the results obtained.