On the Deformation of the Circumflex Coronary Artery During Inflation Tests at Constant Length

Here we investigate whether the deformation observed in an experiment in which the porcine circumflex coronary artery is subjected to inflation at constant length included in the class, , , . We find that this is not the case and discuss its implications in the study of the mechanics of this artery. Moreover, we identify and quantify the uncertainty in the value of the invariants of the left Cauchy–Green tensor inferred from the 2D motion of markers affixed to the surface of the test specimen, and suggest that 3D tracking of markers is needed due to inherent bending and twisting induced by pressurization in vitro.     

Stability analysis of the Rayleigh–Bénard convection for a fluid with temperature and pressure dependent viscosity

The classical problem of thermal-convection involving the classical Navier–Stokes fluid with a constant or temperature dependent viscosity, within the context of the Oberbeck–Boussinesq approximation, is one of the most intensely studied problems in fluid mechanics. In this paper, we study thermal-convection in a fluid with a viscosity that depends on both the temperature and pressure, within the context of a generalization of the Oberbeck–Boussinesq approximation. Assuming that the viscosity is an analytic function of the temperature and pressure we study the linear as well as the non-linear stability of the problem of Rayleigh–Bénard convection. We show that the principle of exchange of stability holds and the Rayleigh numbers for the linear and non-linear stability coincide.     

<Emphasis Type="Italic">Brugia malayi</Emphasis> Thioredoxin Peroxidase as a Potential Vaccine Candidate Antigen for Lymphatic Filariasis

Attempts were made to evaluate the protective efficacy of Brugia malayi thioredoxin peroxidase (BmTPX) in a mouse model. Mice immunized with a protein vaccine containing rBmTPX developed higher titres (1:5,000/1:10,000) of anti-BmTPX antibodies, compared with the mice immunized with the alum control. There was a higher level of cellular proliferative response in mice immunized with BmTPX compared with the alum control (p?<?0.05), which was associated with a Th2-type of response. In order to compare the prophylactic efficacy of BmTPX in natural infection, we evaluated the human immune responses to these antigens in endemic normals (EN) and infected individuals (microfilaraemic and chronic pathology). Results showed that EN subjects carry BmTPX-specific IgG1 and IgG3 circulating antibodies against natural exposure to filariasis. Peripheral blood mononuclear cells from EN subjects responded strongly to rBmTPX by proliferating, as well as by secreting interferon (IFN)-γ (Th1) and IL-5 (Th2), a mixed type of response to rBmTPX. In the case of infected individuals, there was no IFN-γ or IL-5 response. Thus, there was a clear dichotomy in the cytokine production by infected versus EN individuals. Our findings suggest that BmTPX may be a suitable antigen candidate for lymphatic filariasis, but a further study is still required.     

Highly Sensitive Optical Biosensor for Thrombin Based on Structure Switching Aptamer-Luminescent Silica Nanoparticles

We describe here the construction of a sensitive and selective optical sensor system for the detection of human α-thrombin. The surface functionalized luminescent [Ru(dpsphen)₃]^4? (dpsphen-4,7-diphenyl-1,10-phenanthroline disulfonate) ion doped silica nanoparticles (SiNPs) with a size ~70 nm have been prepared. The DABCYL (2-(4-dimethylaminophenyl)diazenyl-benzoic acid) quencher labeled thrombin binding aptamer is conjugated to the surface of SiNPs using BS³ (bis(sulfosuccinimidyl) suberate) as a cross-linker, resulting in the conformational change of aptamer to form G-quadruplex structure upon the addition of thrombin. The binding event is translated into a change in the luminescence intensity of Ru(II) complex via FRET mechanism, due to the close proximity of DABCYL quencher with SiNPs. The selective detection of thrombin using the SiNPs-aptamer system up to 4 nM is confirmed by comparing its sensitivity towards other proteins. This work demonstrates the application of simple aptamer-SiNPs conjugate as a highly sensitive system for the detection of thrombin and also it is highly sensitive towards thrombin in the presence of other proteins and complex medium such as BSA.     

Emulsion polymerization of vinyl acetate

Emulsion polymerization of vinyl acetate with sodium laryl sulfate as emulsifier and potassium persulfate as initiator was studied and found to follow the rate equation suggested by Harriot:      

Furanverbindungen, 11. Mitt.

Zusammenfassung Es wird über die Synthese einiger angulärer Furoxanthone mit einer Methylgruppe in -oder -Stellung oder einer Phenylgruppe in der -Stellung des Furanrings berichtet. Ausgegangen wurde von einem Hydroxyxanthon mit einem Orcinkern.

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The synthesis of a few angular furano-xanthones carrying a methyl group either in -or in -position or a phenyl group in the -position of the furan ring, starting with an hydroxy xanthone possessing an orcinol nucleus is recorded.

     

Luminescence enhancement induced by aggregation of alkoxy-bridged rhenium(I) molecular rectangles

Self-assembly of rhenium(I)-based molecular rectangles containing long alkyl chains has been achieved in one-pot synthesis by solvothermal methods. An enormous enhancement in the emission intensity, quantum yield, and lifetime of the rectangles has been observed when the solvent medium is changed from organic to aqueous. Addition of water favors the aggregation of Re(I) molecular rectangle resulting in the luminescence enhancement, and this phenomenon has been traced out using light scattering techniques.     

Recognition of aromatic amino acids and proteins with p‐sulfonatocalix[4]arene – A luminescence and theoretical approach

The host–guest interaction of p‐sulfonatocalix[4]arene (p‐SC4) with aromatic amino acids (AAs) and two proteins has been studied using UV–Vis absorption, fluorescence, and theoretical methods. Spectral studies supported by binding constant and calculated binding energy (BE) values show that p‐SC4 binds more strongly with tyrosine compared with other AAs. The application of Bader's theory of atoms in molecule shows the involvement of various types of noncovalent interactions in the formation of the host–guest complexes. Both tyrosine and histidine have strong electrostatic interaction with the sulfonato group and other two AAs have dominant π?π interaction with the aromatic rings of calixarene. In addition, the role of C?H···O, C?H···π and lone pair···π (lp···π) interactions in the stabilization of p‐SC4‐AA complexes has also been realized from the atoms in molecule analysis. The electron density at the bond critical points varies with the calculated BEs and trend in BEs is in good agreement with the experimental binding constant values. The work has been extended to the binding of p‐SC4 with proteins, bovine serum albumin and ovalbumin. Ovalbumin exhibits stronger binding with p‐SC4 than bovine serum albumin. Copyright © 2012 John Wiley & Sons, Ltd.