Influence of polymer excluded volume on the phase behavior of colloid-polymer mixtures

We determine the depletion-induced phase-behavior of hard sphere colloids and interacting polymers by large-scale Monte Carlo simulations using very accurate coarse-graining techniques. A comparison with standard Asakura-Oosawa model theories and simulations shows that including excluded volume interactions between polymers leads to qualitative differences in the phase diagrams. These effects become increasingly important for larger relative polymer size. Our simulations results agree quantitatively with recent experiments.Comment: 5 pages, 4 figures submitted to Physical Review Letter

Infrared Reflection Spectra of (FeIn2S4)x∙(In2S3)1–x Solid Solutions

IR reflectance spectroscopy at 50–450 cm–1 was used to study homogeneous monocrystals of (FeIn2S3)x∙(In2S3)1–x grown by the method of direction melt crystallization (vertical Bridgman method). The frequencies of the transverse (ωTO) and longitudinal optical phonons (ωLO) as well as their damping coefficients were determined. Concentration dependence curves were constructed for these parameters and their behavior was established

Infrared reflection spectra of MnxFe1–xIn2S4 solid solutions

Large-block crystals of FeIn2S4 and MnIn2S4 ternary compounds and MnxFe1–xIn2S4 solid solutions are grown by irectional crystallization (horizontal Bridgman method). The structures of the obtained crystals are determined by x-ray diffraction analysis. Both the starting compounds and the solid solutions based on them are shown to crystallize in the cubic spinel structure. IR reflection spectra in the range 50–500 cm–1 of crystals of FeIn2S4 and MnIn2S4 ternary compounds and FexMn1–xIn2S4 solid solutions are studied. The frequencies of transverse (ωTO) and longitudinal (ωLO) optical phonons are determined. The concentration dependences of these parameters are plotted. The nature of their behavior is established

Effect of Silicon Content on Carbide Precipitation and Low-Temperature Toughness of Pressure Vessel Steels

Cr – Mn – Mo – Ni pressure vessel steels containing 0.54 and 1.55% Si are studied. Metallographic and fractographic analyses of the steels after tempering at 650 and 700°C are performed. The impact toughness at – 30°C and the hardness of the steels are determined. The mass fraction of the carbide phase in the steels is computed with the help of the J-MatPro 4.0 software

Mapping of polycrystalline films of biological fluids utilizing the Jones-matrix formalism

Utilizing a polarized light approach, we reconstruct the spatial distribution of birefringence and optical activity in polycrystalline films of biological fluids. The Jones-matrix formalism is used for an accessible quantitative description of these types of optical anisotropy. We demonstrate that differentiation of polycrystalline films of biological fluids can be performed based on a statistical analysis of the distribution of rotation angles and phase shifts associated with the optical activity and birefringence, respectively. Finally, practical operational characteristics, such as sensitivity, specificity and accuracy of the Jones-matrix reconstruction of optical anisotropy, were identified with special emphasis on biomedical application, specifically for differentiation of bile films taken from healthy donors and from patients with cholelithiasis

Gut Microbiome Phenotypes Driven by Host Genetics Affect Arsenic Metabolism

Large individual differences in susceptibility to arsenic-induced diseases are well-documented and frequently associated with different patterns of arsenic metabolism. In this context, the role of the gut microbiome in directly metabolizing arsenic and triggering systemic responses in diverse organs raises the possibility that gut microbiome phenotypes affect the spectrum of metabolized arsenic species. However, it remains unclear how host genetics and the gut microbiome interact to affect the biotransformation of arsenic. Using an integrated approach combining 16S rRNA gene sequencing and HPLC-ICP-MS arsenic speciation, we demonstrate that IL-10 gene knockout leads to a significant taxonomic change of the gut microbiome, which in turn substantially affects arsenic metabolism.National Institute of Environmental Health Sciences (P30 ES010126)National Institute of Environmental Health Sciences (NIEHS grant P30 ES002109)University of Georgia. College of Public Health (internal grant)University of Georgia (Faculty Research Grant (FRG)

Enhancement of Cardiac Store Operated Calcium Entry (SOCE) within Novel Intercalated Disk Microdomains in Arrhythmic Disease

Store-operated Ca2+ entry (SOCE), a major Ca2+ signaling mechanism in non-myocyte cells, has recently emerged as a component of Ca2+ signaling in cardiac myocytes. Though it has been reported to play a role in cardiac arrhythmias and to be upregulated in cardiac disease, little is known about the fundamental properties of cardiac SOCE, its structural underpinnings or effector targets. An even greater question is how SOCE interacts with canonical excitation-contraction coupling (ECC). We undertook a multiscale structural and functional investigation of SOCE in cardiac myocytes from healthy mice (wild type; WT) and from a genetic murine model of arrhythmic disease (catecholaminergic ventricular tachycardia; CPVT). Here we provide the first demonstration of local, transient Ca2+ entry (LoCE) events, which comprise cardiac SOCE. Although infrequent in WT myocytes, LoCEs occurred with greater frequency and amplitude in CPVT myocytes. CPVT myocytes also evidenced characteristic arrhythmogenic spontaneous Ca2+ waves under cholinergic stress, which were effectively prevented by SOCE inhibition. In a surprising finding, we report that both LoCEs and their underlying protein machinery are concentrated at the intercalated disk (ID). Therefore, localization of cardiac SOCE in the ID compartment has important implications for SOCE-mediated signaling, arrhythmogenesis and intercellular mechanical and electrical coupling in health and disease

Towards the growth of Cu2ZnSn1-xGexS4 thin films by a single-stage process: Effect of substrate temperature and composition

Cu2ZnSn1-xGexS4 (CZTGS) thin films prepared by flash evaporation of a Zn-rich Cu2ZnSn0.5Ge0.5S4 bulk compound in powder form, and a subsequent thermal annealing in S containing Ar atmosphere are studied. The effect of the substrate temperature during evaporation and the initial composition of the precursor powder on the growth mechanism and properties of the final CZTGS thin film are investigated. The microstructure of the films and elemental depth profiles depend strongly on the growth conditions used. Incorporation of Ge into the Cu2ZnSnS4 lattice is demonstrated by the shift of the relevant X-ray diffraction peaks and Raman vibrational modes towards higher diffraction angles and frequencies respectively. A Raman mode at around 348-351 cm-1 is identified as characteristic of CZTGS alloys for x = [Ge]/([Sn]+[Ge]) = 0.14-0.30. The supply of Ge enables the reduction of the Sn loss via a saccrifical Ge loss. This fact allows increasing the substrate temperature up to 350º C during the evaporation, forming a high quality kesterite material and therefore, reducing the deposition process to one single stageRC acknowledges financial support from Spanish MINECO within the Ramón y Cajal programme (RYC-2011-08521) and VIR for the Juan de la Cierva fellowship (JCI-2011-10782). GB also acknowledges the CSIC-JAE pre-doctoral program, co-funded by the European Social Fund. This work was supported by the Marie Curie-IRSES project (PVICOKEST, GA: 269167), Marie Curie-ITN project (KESTCELL, GA: 316488), DAAD project (INTERKEST, Ref: 57050358), and MINECO projects (SUNBEAM, ENE2013-49136-C4-3-R) (TEC2012-38901-C02-01). A. Scheu is acknowledged for GDOES measurement

Spectroscopic ellipsometry study of Cu2ZnSnSe4 bulk crystals

Using spectroscopic ellipsometry we investigated and analyzed the pseudo-optical constants of Cu2ZnSnSe4 bulk crystals, grown by the Bridgman method, over 0.8-4.5 eV photon energy range. The structures found in the spectra of the complex pseudodielectric functions were associated to E0, E1A, and E1B interband transitions and were analyzed in frame of the Adachi's model. The interband transition parameters such as strength, threshold energy, and broadening were evaluated by using the simulated annealing algorithm. In addition, the pseudo-complex refractive index, extinction coefficient, absorption coefficient, and normal-incidence reflectivity were derived over 0.8-4.5 eV photon energy rang