Altered signaling associated with chronic arsenic exposure in human skin keratinocytes

Modulation of signaling pathways upon chronic arsenic exposure remains poorly studied. Here, we carried out SILAC‐based quantitative phosphoproteomics analysis to dissect the signaling induced upon chronic arsenic exposure in human skin keratinocyte cell line, HaCaT. We identified 4171 unique phosphosites derived from 2000 proteins. We observed differential phosphorylation of 406 phosphosites (twofold) corresponding to 305 proteins. Several pathways involved in cytoskeleton maintenance and organization were found to be significantly enriched (p<0.05). Our data revealed altered phosphorylation of proteins associated with adherens junction remodeling and actin polymerization. Kinases such as protein kinase C iota type (PRKCI), mitogen‐activated protein kinase kinase kinase 1 (MAP3K1), tyrosine‐protein kinase BAZ1B (BAZ1B) and STE20 like kinase (SLK) were found to be hyperphosphorylated. Our study provides novel insights into signaling perturbations associated with chronic arsenic exposure in human skin keratinocytes. All MS/MS data have been deposited to the ProteomeXchange with identifier PXD004868.     

Pyroelectric properties of Gd-doped KVO3 and LiVO3

Pyroelectric properties of Gd-doped and undoped potassium vanadate and lithium vanadate investigated in the temperature range covering their transition points show sharp increase at Curie temperature for undoped and for 0·025, 0·05, 0·1 mol% Gd₂O₃-doped, but no remarkable peak at Curie temperature for 0·5, 1, 3 mol% Gd₂O₃-doped KVO₃ and LiVO₃. The Curie temperature of all the samples remains the same for various concentrations of Gd.     

Ethanol gas sensing properties of Al<Subscript>2</Subscript>O<Subscript>3</Subscript>-doped ZnO thick film resistors

The characterization and ethanol gas sensing properties of pure and doped ZnO thick films were investigated. Thick films of pure zinc oxide were prepared by the screen printing technique. Pure zinc oxide was almost insensitive to ethanol. Thick films of Al₂O₃ (1 wt%) doped ZnO were observed to be highly sensitive to ethanol vapours at 300°C. Aluminium oxide grains dispersed around ZnO grains would result into the barrier height among the grains. Upon exposure of ethanol vapours, the barrier height would decrease greatly leading to drastic increase in conductance. It is reported that the surface misfits, calcination temperature and operating temperature can affect the microstructure and gas sensing performance of the sensor. The efforts are, therefore, made to create surface misfits by doping Al₂O₃ into zinc oxide and to study the sensing performance. The quick response and fast recovery are the main features of this sensor. The effects of microstructure and additive concentration on the gas response, selectivity, response time and recovery time of the sensor in the presence of ethanol vapours were studied and discussed.     

Impurity controlled diffusion reaction in thorium-vanadium system

The effect of ppm level impurities present in the thorium metal on the diffusion reaction in thorium-vanadium system has been investigated by making “sandwich” type diffusion couples and annealing them in the temperature range of 900 to 1200°C. The microstructure of the diffusion zone has been examined by optical and electron microscopy. X-ray powder techniques have been employed to detect the presence of secondary intermetallic phases in thorium metal and in the diffusion zone. The chemical composition of these phases and the elemental distribution in the diffusion zone have been established by using an electron microprobe analyzer. The time and the temperature dependence of the diffusion zone width is used to evaluate the kinetics of layer growth. Present studies have shown that impurities like iron, copper and aluminum form low melting point intermetallic compounds in thorium metal and segregate at the grain boundaries. Further in a diffusion reaction at the elevated temperatures, these thorium rich secondary phases melt and form a liquid film between the thorium and the bonding metal, vanadium in the present case. The rate controlling process appears to be an interfacial chemical reaction involving dissolution of vanadium in the thorium rich liquid.     

EVALUATION OF DIFFUSION EQUATION FOR SIMULATING MOlSTURE MOVEMENT WITHIN AN INDIVIDUAL GRAIN KERNEL

Drying of agricultural grains by and large takes place in the diffusion controlled falling rate period. Therefore, an understanding of the phenomenon of moisture transfer within an individual particles of material is desirable and should be represented precisely by a mathematical model. This paper describes a numerical solution that has been developed for solving spherical diffusion equation describing moisture movement within a grain kernel for accurately calculating bulk drying rate.

All agricultural materials in general, when drying as a single particle under constant external conditions, exhibit a constant rate moisture loss     

Microstructures of CaSO3 0·5 H2O single crystals grown in silica gel

This paper deals with the study of surface structures of silica gel grown crystals of CaSO₃ 0·5 H₂O. Various growth features such as growth layers, overgrowths and oriented and random liquid inclusions have been observed using optical and scanning electron microscopy techniques.     

On the efficiency of on-line density estimators

An on-line density estimator may be defined to be one where each update, following the arrival of a new data value, may be accomplished after no more than a fixed number of calculations. This definition should also apply to any empirical bandwidth selection rule for such an estimator. Recursive estimators comprise only a special case of on-line estimators, but even there, on-line bandwidth formulas have not been developed. The authors introduce a class of on-line estimators, and discuss efficiency in this context. It is shown that some nonrecursive members of the class achieve greater efficiency than any recursive estimators, and that efficiency increases to 100% as the order of the estimated derivative increases. On-line bandwidth selection rules, enabling these high orders of efficiency to be achieved asymptotically, are introduced     

Molecular packing at surfaces of oriented polyimide fiber and film observed by atomic force microscopy

Summary Molecular morphology of a surfaces of fibers and films from novel segmented polyimides with different rigidity of the backbones was studied by atomic force microscopy. It was observed that surface morphology on a molecular scale is formed by straight segments arranged in a {1–10} plane for polymide fiber and in a {010} plane for polyimide film. Z-shaped backbone segments at the fiber surfaces are arranged at definite angles with respect to the fiber axis. The parameters of unique cells, positional correlations and the arrangement of molecular segments at the interface are discussed.     

Glycogen--a covalently linked component of the cell wall in Saccharomyces cerevisiae.

Glycogen in Saccharomyces cerevisiae is present in two pools, one soluble and intracellular, the other present in the cell wall and rendered water-insoluble owing to its covalent linkage to cell wall beta-glucan. The insoluble glycogen fraction was solubilized using beta-1,3-glucanase. The alpha beta-glucan complex obtained showed intense red staining with iodine and was isolated from free beta-glucans by affinity chromatography using concanavalin A sepharose 4B. Further use of molecular sieving has confirmed that glycogen is linked to beta-glucan as the non-retained fraction on Biogel P2 split into two peaks on treatment with amyloglucosidase. Partial acid hydrolysis and subsequent paper chromatography of the alpha beta-glucan complex isolated revealed the presence of gentiobiose and other higher oligosaccharides, indicating that glycogen is linked to beta-1,3-glucan through a beta-1,6 branch. The insoluble glycogen can be extracted in a soluble form by acetic acid treatment and is known as acid-soluble glycogen. The presence of glycogen in the cell wall is confirmed by controlled enzymatic release of alpha beta-glucan complex using lyticase from Arthobacter luteus without disruption of the plasma membrane, as can be visualized using electron microscopy.