ZnO Nanorods via Spray Deposition of Solutions Containing Zinc Chloride and Thiocarbamide

In this work we present the results on formation of ZnO nanorods prepared by spray of aqueous solutions containing ZnCl2and thiocarbamide (tu) at different molar ratios. It has been observed that addition of thiocarbamide into the spray solution has great impact on the size, shape and phase composition of the ZnO crystals. Obtained layers were characterized by scanning electron microscopy (SEM) equipped with energy selected backscattered electron detection system (ESB), X-ray diffraction (XRD) and photoluminescence spectroscopy (PL). Small addition of thiocarbamide into ZnCl2solution (ZnCl2:tu = 1:0.25) supports development of significantly thinner ZnO nanorods with higher aspect ratio compared to those obtained from ZnCl2solution. Diameter of ZnO rods decreases from 270 to 100 nm and aspect ratio increases from ∼2.5 to 12 spraying ZnCl2and ZnCl2:tu solutions, respectively. According to XRD, well crystallized (002) orientated pure wurtzite ZnO crystals have been formed. However, tiny ‘spot’—like formations of ZnS were detected on the side planes of hexagonal rods prepared from the thiocarbamide containing solutions. Being adsorbed on the side facets of the crystals ZnS inhibits width growth and promotes longitudinalc-axis growth

THE OPTIMIZATION OF THE PARAMETERS OF CULTIVATION OF THE RECOMBINANT HES+STRAIN B. SUBTILIS AND THE DEVELOPMENT OF THE INDUSTRIAL TECHNOLOGY OF RIBOFLAVINE BIOSYNTHESIS ON ITS BASE

For the first time, the possibility of the controllable cultivation and industrial application of the hes+strain-producers of riboflavine has been determined. First the supersynthesis of levanes (to 40 g/l) has been detected with cultures of kin Bacillus. The industrial technology of biosynthesis of riboflavine has been developed on the base of hes+strain and successfully and approved under the plant conditions. The possibility of creation of the industrial superproducer of levanes has been shown. The developed industrial technology has undergone the successful tests on the plant pilot unit and is on the stage of introduction on the industrial fermentersAvailable from VNTIC / VNTIC - Scientific & Technical Information Centre of RussiaSIGLERURussian Federatio

Selective performance of sol-gel synthesised titanium dioxide photocatalysts in aqueous oxidation of various-type organic pollutants

Photocatalysts synthesized by sol-gel method inevitably incorporate carbon together with dopants. The objective of the research consists in the synthesis and testing of photocatalytic activity of carbon-containing titanium dioxide photocatalysts calcinated at various temperatures. The optical and structural properties of the catalysts were also studied. The activity was tested in visible light in aqueous photocatalytic oxidation of three various-type pollutants, methyl-tert-butyl ether, p-toluidine and phenol, where the divergent character of the C-TiO catalysts was distinctively observed: methyl-tert-butyl ether and p-toluidine were oxidized with the efficiency close to or even surpassing that of UV-irradiated P25 (Evonik), whereas phenol was oxidized poorly. The observed photocatalytic activity, where quantum efficiency varied from 0.6 to 2.3 and from 0.1 to 1.2% for p-toluidine and phenol degradation respectively, may be explained by the different electrostatic properties of the catalysts surface and the tested substances, i.e. their interaction. This compromises the widespread usage of phenol as a reference substance for comparison of catalytic activities of catalysts

Thymosin β(4) Induces a Conformational Change in Actin Monomers

Using fluorescence resonance energy transfer spectroscopy we demonstrate that thymosin β(4) (tβ(4)) binding induces spatial rearrangements within the small domain (subdomains 1 and 2) of actin monomers in solution. Tβ(4) binding increases the distance between probes attached to Gln-41 and Cys-374 of actin by 2 Å and decreases the distance between the purine base of bound ATP (ɛATP) and Lys-61 by 1.9 Å, whereas the distance between Cys-374 and Lys-61 is minimally affected. Distance determinations are consistent with tβ(4) binding being coupled to a rotation of subdomain 2. By differential scanning calorimetry, tβ(4) binding increases the cooperativity of ATP-actin monomer denaturation, consistent with conformational rearrangements in the tβ(4)-actin complex. Changes in fluorescence resonance energy transfer are accompanied by marked reduction in solvent accessibility of the probe at Gln-41, suggesting it forms part of the binding interface. Tβ(4) and cofilin compete for actin binding. Tβ(4) concentrations that dissociate cofilin from actin do not dissociate the cofilin-DNase I-actin ternary complex, consistent with the DNase binding loop contributing to high-affinity tβ(4)-binding. Our results favor a model where thymosin binding changes the average orientation of actin subdomain 2. The tβ(4)-induced conformational change presumably accounts for the reduced rate of amide hydrogen exchange from actin monomers and may contribute to nucleotide-dependent, high affinity binding

Assembly of high-affinity insulin receptor agonists and antagonists from peptide building blocks

Insulin is thought to elicit its effects by crosslinking the two extracellular α-subunits of its receptor, thereby inducing a conformational change in the receptor, which activates the intracellular tyrosine kinase signaling cascade. Previously we identified a series of peptides binding to two discrete hotspots on the insulin receptor. Here we show that covalent linkage of such peptides into homodimers or heterodimers results in insulin agonists or antagonists, depending on how the peptides are linked. An optimized agonist has been shown, both in vitro and in vivo, to have a potency close to that of insulin itself. The ability to construct such peptide derivatives may offer a path for developing agonists or antagonists for treatment of a wide variety of diseases