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This study examined the pattern of resistance to widely applied synthetic pyrethroids, i.e., cypermethrin and deltamethrin, against larvae of Rhipicephalus microplus ticks sampled from Marathwada region in Maharashtra, India. The study also examined the role of α- and β-esterases and glutathione-S-transferase (GST) in resistance development. All eight R. microplus isolates tested were resistant to deltamethrin (RL IV), having RR50 values from 6.88 to 131.26. LPT analysis exhibited the resistance level II deltamethrin resistance in Beed and Hingoli, III in Dharashiv, and IV in Sambhajinagar, Parbhani, Latur, Jalna, and Nanded isolates. The LIT analysis showed that Dharashiv field isolates had the lowest LC50 value of 229.09 ppm against cypermethrin, while Sambhajinagar field isolates had the highest at 489.78 ppm. The RR50 ranged from 1145.45 to 2448.9. Seven isolates were level I resistant to cypermethrin while the Jalna isolate was level II resistant. In larvae treated with deltamethrin and cypermethrin, the activity of α- and β-esterase enzymes increased significantly compared to control groups. The enzyme ratios in treated larvae ranged from 0.7533 to 1.7023 for α-esterase and 0.7434 to 3.2054 for β-esterase. The Hingoli isolate treated with cypermethrin exhibited the highest α-esterase activity (903.261), whereas Sambhajinagar isolate had the highest GST enzyme ratio (2.8224) after deltamethrin exposure. When exposed to cypermethrin, the Hingoli isolate showed the highest GST enzyme ratio, 2.0832. The present study provides the current resistance status in tick populations from Marathwada region indicating deltamethrin and cypermethrin to be ineffective for tick control. The results also suggest that SP compounds should be regulated in this region and alternative control strategies should be introduced. [ABSTRACT FROM AUTHOR]

The current study reports a Pickering dry emulsion (PDE) system for improved oral delivery of fenofibrate, a poorly water-soluble model drug. The silica nanoparticles were modified by surface modifiers and explored as a stabilizer for emulsion. The wetting property of modified silica nanoparticles was evaluated by contact angle study. Emulsion was spray-dried to obtain PDE. PDE was evaluated for particle size analysis, drug loading, TGA, DSC, XRPD, FEG-SEM, in vitro dissolution study, and in vivo pharmacodynamic study. The particle size of liquid emulsion was found within the range of 0.3–0.6 μm; after spray drying, the particles agglomerated and exhibited an increase in particle size (1.5 μm). The high drug loading (13% w/w) was found in PDE. DSC and XRD study confirmed the amorphous form of fenofibrate. SEM study showed the formation of a spherical porous microcapsule structure. In vitro dissolution exhibited significant enhancement in drug release for the PDE system as compared to plain fenofibrate. The PDE significantly lowered serum lipid level as compared to plain fenofibrate in a Triton-based hypercholesterolemia model in rats, which ultimately confirmed the enhancement in bioavailability. Thus, the PDE system has good potential in the drug delivery area. [ABSTRACT FROM AUTHOR]

In the present study, the crude aqueous and chloroform extracts of Annona squamosa was tested for its in-vitro acaricidal efficacy against Rhipicephalus microplus ticks. Concentrations of 2.5%, 5%, 7.5%, 10% and 12.5% were tested against adult ticks whereas 0.312%, 0.625%, 1.25% and 2.5% were tested against larvae. No significant mortality and effect on oviposition was observed using aqueous extract, however, chloroform extract showed strong activity against both viz. adults and larvae. The highest adult mortality was observed at 12.5% concentration and determined LC50 and LC90 values were 5.24% and 14.12% respectively. A dose dependent reduction in egg laying capacity of treated female was observed in all concentrations compared to control group. The recorded mean mortality of larvae was 13.45 ± 0.73, 71.04 ± 1.10, 98.28 ± 0.39 and 100 ± 0.00 observed at 0, 0.312%, 0.625%, 1.25% and 2.5% of concentrations respectively. [ABSTRACT FROM AUTHOR]

A study was conducted to investigate the tick infestation on cattle in the plain region of Chhattisgarh state. During the period of study, 832 ticks of 47 animals were examined for the different tick species. The most prominently infested ixodid tick belonged to Hyalomma anatolicum (68.38%) followed by Rhipicephalus microplus (30.40%).The females showed higher infestation than males. A single tick species infestation pattern was observed in 17 animals while 30 animals were infested by both tick species. Single species infestation of H. anatolicum was encountered in 15 animals while R. microplus was observed in 2 animals. The intensity of tick infestation on each animal varied from 6 to 65 ticks per animal at different locations. [ABSTRACT FROM AUTHOR]

A series of Gd3+-doped BaMgAl10O17 phosphors have been successfully synthesized using a low-temperature solution combustion method. The crystal structure and phase purity of the samples were characterized using x-ray powder diffraction analysis. The optimal concentration of Gd3+ dopant in BaMgAl10O17 was determined through measurements of the photoluminescence spectra of the phosphors. All phosphors showed narrowband UVB emission at 313 nm with excitation wavelength at 272 nm. Relatively dominant electron spin resonance (ESR) lines were observed with geff ≈ 1.98. 2.7, 4.2, and 5.95 in phosphors with low concentration of dopant Gd3+ ion. At higher dopant concentrations, the spectrum appeared to be U-like with prominent lines at geff ≈ 1.99, 2.7, 4.2, and 5.94. Distortions in the neighborhood of Gd3+ ion led to ESR lines in the low-field region of the spectrum. [ABSTRACT FROM AUTHOR]

As the required energy demand of humans keep increasing rapidly, the quest for developing new and efficient alternative energy resources progresses. Keeping the future energy crisis in mind, solar cells, particularly the low-cost dye and quantum dot sensitized solar cells seem to be a promising solution. Using solid polymer electrolyte in such solar cells proves to be a viable alternative as it contributes to the overall stability of the cell. However, there are certain details pertaining to solar cells where polymer electrolyte is used which have not yet been discussed in length. In this paper, we discuss the polarization effect of PEO-based quasi-solid electrolyte in DSSC and QDSC. [ABSTRACT FROM AUTHOR]

The aim of present investigation was the preparation of dodecylamine template-based hexagonal mesoporous silica (HMS) as a carrier for poorly water-soluble drug (fenofibrate). HMS material has distinctive characteristics such as easy synthesis, high surface area and wormhole pores. These characteristics are highly admirable to make use of it as a carrier in drug delivery system. HMS was prepared by pH and temperature-independent process. Fenofibrate was loaded into the HMS by solvent immersion method using organic solvent. The BET surface area of HMS was evaluated by nitrogen adsorption/desorption analysis. HMS and drug-loaded HMS were characterized by differential scanning calorimetry (DSC), X-ray powder diffraction (XRPD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and contact angle study. The HMS-based system was also evaluated for in vitro and in vivo study as compared to plain drug. The BET surface area of HMS was found 974 m/g with a narrow pore size average of 2.6 nm. The DSC and XRD study confirmed the amorphization of drug within the HMS. SEM and TEM study showed morphological features of HMS as well as revealed the wormhole porous structure. Contact angle study showed improvement in aqueous wetting property of drug within the HMS (contact angle 46°). The In vitro drug release study showed a remarkable dissolution enhancement in HMS-based system as compared to plain drug. In vivo pharmacodynamic study (hyperlipidaemia model) exhibited HMS-based formulation was significantly improved the bioavailability of fenofibrate. Thus, HMS has admirable properties; makes it a potential carrier for delivery system of poorly water-soluble drugs. [ABSTRACT FROM AUTHOR]

Mesoporous ZnO nanoparticles have been synthesized with tremendous increase in specific surface area of up to 578 m/g which was 5.54 m/g in previous reports (J. Phys. Chem. C 113:14676-14680, 2009). Different mesoporous ZnO nanoparticles with average pore sizes ranging from 7.22 to 13.43 nm and specific surface area ranging from 50.41 to 578 m/g were prepared through the sol-gel method via a simple evaporation-induced self-assembly process. The hydrolysis rate of zinc acetate was varied using different concentrations of sodium hydroxide. Morphology, crystallinity, porosity, and J- V characteristics of the materials have been studied using transmission electron microscopy (TEM), X-ray diffraction (XRD), BET nitrogen adsorption/desorption, and Keithley instruments. [ABSTRACT FROM AUTHOR]

A simple electrostatic model is applied to study the solvation energy and localization energy to inorganic semiconductor nanocrystallites trapped in polymer and ion conducting polymer electrolytes. The effective mass approximation has been applied to the system. In the single charge configuration, the dielectric constant of the medium has been identified as the selection criteria for hosting the nanoparticles. Solvation energy has been shown to depend on the host medium and the size of the crystallite. [ABSTRACT FROM AUTHOR]

Stress is believed to be the main driving force for whisker formation in Sn coatings on Cu. This suggests that whiskering can be suppressed by enhancing stress relaxation in the Sn layer, which is believed to be the reason why Sn-Pb alloys do not form whiskers. However, Pb is no longer acceptable for use in electronics manufacturing. As an alternative, we used pulsed plating to create Sn-Bi coatings with an equiaxed microstructure similar to that of Sn-Pb alloys. An optical wafer curvature technique was used to measure stress relaxation kinetics in Sn, Sn-Pb and Sn-Bi alloy thin films during thermal cycles. The results show that Sn-Bi films have significantly enhanced stress relaxation relative to pure Sn films. Comparison between Sn-Bi samples with equiaxed and columnar microstructures shows that both microstructure and alloy composition play a role in enhancing the stress relaxation. [ABSTRACT FROM AUTHOR]

Sn whisker and hillock formation is a reliability risk that has become increasingly important as the electronics industry has moved toward Pb-free manufacturing. To prevent them, we would like to understand what makes specific sites susceptible to deform into whiskers. We have used in situ scanning electron microscopy (SEM)/electron backscattering diffraction (EBSD) to monitor simultaneously the evolution of surface morphology and grain orientation in Sn surfaces in order to correlate whisker/hillock initiation with the underlying microstructure. Because rough films are difficult to measure with EBSD, we developed a unique procedure to make Sn-Cu samples with ultra-flat surfaces so that a large fraction of Sn grains can be indexed over repeated scans. We find that whiskers/hillocks grow from existing grains (not re-nucleated grains) with orientations close to (001). They often rotate from the as-deposited structure so that the orientation after growth does not indicate the orientation from which the whisker initiated. We measured the interface structure after removal of the Sn layer by chemical etching and found that there is no excessive accumulation of intermetallic compound around the whisker/hillock roots. Cross-sectional measurements revealed that a large fraction of the whiskers/hillocks have oblique boundaries underneath the surface, supporting the idea that these allow whiskers/hillocks to grow with lower stress. [ABSTRACT FROM AUTHOR]

Stress is believed to provide the driving force for growth of Sn whiskers, so stress relaxation in the Sn layer plays a key role in their formation. To understand and enhance stress relaxation in Sn-based films, the effects of Pb alloying and microstructure on their mechanical properties have been studied by observing the relaxation of thermal expansion-induced strain. The relaxation rate is found to increase with film thickness and grain size in pure Sn films, and it depends on the microstructure in Pb-alloyed Sn films. Measurements of multilayered structures (Sn on Pb-Sn and Pb-Sn on Sn) show that changing the surface layer alone is not sufficient to enhance the relaxation, indicating that the Pb enhances relaxation in the bulk of the film and not by surface modification. Implications of our results for whisker mitigation strategies are discussed. [ABSTRACT FROM AUTHOR]

Compressive stress due to intermetallic (IMC) growth appears to be the main driving force for whisker formation, but many of the underlying mechanisms relating the IMC to stress and whisker formation are not understood. To better understand these fundamental processes, we have measured IMC, stress and whisker evolution in Sn layers deposited on Cu. We present systematic results of the effect of changing the Sn layer structure by modifying the grain size, thickness, Pb content, microstructure, and IMC morphology/growth kinetics. We have also made corresponding measurements of the mechanical properties of the Sn with similar changes in the structure and composition without the growth of IMC. We show that modifications that enhance the stress relaxation in the Sn also lead to reduced whisker growth. [ABSTRACT FROM AUTHOR]

The electrical, structural, and photoelectrochemical properties of the polymer electrolyte PEO:NaI/I doped with an ionic liquid 1-ethyl 3-methylimidazolium dicyanamide (EMImDCN) have been reported. Incorporation of the ionic liquid (IL) increases the membrane homogeneity, decreased surface roughness, and enhances the short current ( J). Additionally, the doping of IL provides more charge carriers which enhances overall ionic conductivity (σ). The optimized σ was found at 40 wt.% IL composition. The fabricated DSSC using this new solid electrolyte showed 1.43% efficiency at 100 mW cm. [ABSTRACT FROM AUTHOR]

We report on real-time measurements that enable us to watch the morphology of whiskers and hillocks forming in real-time and provide insight into the mechanisms controlling their growth and initiation. These measurements show that whiskers appear to grow out of a single grain on the surface with little lateral growth. To understand why whiskers initiate at specific sites, we modified the surface using the focused ion beam to remove the oxide in selected areas. Whiskers did not grow out of these uncovered areas, indicating that the underlying grain structure is important to whisker growth and it is not sufficient to just remove the oxide barrier. In comparison with whiskers, we found that hillock formation is accompanied by a large amount of grain growth and often by grain rotation at the surface. [ABSTRACT FROM AUTHOR]

We use finite element simulations to quantitatively evaluate different mechanisms for the generation of stress in Sn films due to growth of the Cu6Sn5 intermetallic phase at the Cu-Sn interface. We find that elastic and plastic behavior alone are not sufficient to reproduce the experimentally measured stress evolution. However, when grain boundary diffusion is included, the model results agree well with experimental observations. Examination of conditions necessary to produce the observed stresses provides insight into potential strategies for minimizing stress generation and thus mitigating Sn whisker growth. [ABSTRACT FROM AUTHOR]

Sn whisker formation was studied in a "bimetal ledge specimen" that consisted of a uniform layer of Sn that was covered by Cu on only half the sample. Whiskers are observed to grow in the Cu-free region of the sample, which is attributed to stress generated by the diffusion of Sn atoms along the network of columnar grain boundaries. The Sn diffusion is driven by intermetallic growth, but the whisker density extends out much further than any measurable Cu concentration. Whiskers were also observed to grow in the Cu-coated region by punching through the overlayer, leaving a Cu-grain on the tip of the Sn whisker. [ABSTRACT FROM AUTHOR]