High area nickel and cobalt surfaces were assembled using modified Tobacco mosaic virus (TMV) templates. Rod-shaped TMV templates (300 x 18 nm) engineered to encode unique cysteine residues were self-assembled onto gold patterned surfaces in a vertically oriented fashion, producing a >10-fold increase in surface area. Electroless deposition of ionic metals onto surface-assembled virus templates produced uniform metal coatings up to 40 nm in thickness. Within a nickel-zinc battery system, the incorporation of virus-assembled electrode surfaces more than doubled the total electrode capacity. When combined, these findings demonstrate that surface-assembled virus templates provide a robust platform for the fabrication of oriented high surface area materials.

The electrochemical properties of a solid polymer electrolyte consisting of a diblock copolymer and lithium bis͑oxalato͒borate, LiBC 4 O 8 ͑LiBOB͒ salt, is reported. The spherical microphase-separated diblock copolymer is composed of a majority poly͑eth-ylene oxide͒ ͑PEO͒ block and a minority random copolymer block of methyl methacrylate ͑MMA͒ and lithium salt of methacrylic acid ͑MAALi͒, PEO-b-͑PMMA-ran-PMAALi͒. Salt-optimized electrolyte membranes of the diblock copolymer and LiBOB salt exhibited an average lithium-ion transference number ͑T Li +͒ value of 0.9 at room temperature ͑21-23°C͒. The solid-state flexible, translucent polymer electrolyte shows a wide electrochemical stability window and excellent interface properties with the lithium metal electrode. The combination of these properties makes these block copolymer membranes viable electrolyte candidates for flexible lithium-ion batteries.The widespread use of high energy density lithium-ion-based batteries has been constrained by the safety concerns of its reactive components. Thus, the need to design, synthesize, and optimize polymer structures for improved energy storage is of critical importance. Also, advances in lithium cathode chemistries have led to the development of batteries that are capable of delivering a high discharge potential ͑Ͼ4.5 V͒, 1-3 driving the need for electrolyte materials that are capable of withstanding such high voltage conditions. Unlike traditional liquid electrolytes, solid-state polymer electrolytes possess the high electrochemical stability window required for application in high voltage battery setups. Electrolyte membranes incorporating poly͑ethylene oxide͒ ͑PEO͒ with a lithium salt have long been proposed as a viable candidate. 4-6 However, such materials have poor room-temperature ionic conductivity due to the semicrystalline nature of PEO. In addition, PEO-based electrolytes have the intrinsic disadvantage of possessing a low lithium-ion transference number ͑T Li +͒, exhibiting a value between 0.2 and 0.5. 7-10 These polymer-lithium salt systems behave more like an aniontransporting medium, resulting in a charge gradient across the medium. This increases the polarization across the polymer film, leading to loss of power drawn from the battery. 11-13 Studies done by Doyle et al. showed that better performance is exhibited by polymer materials with T Li + = 1.0 than those possessing an order of magnitude greater conductivity but a poorer T Li + value. 11 Hence, the interest is to develop a conductive polymer with high ionic conductivity as well as high lithium-ion transference number.Numerous electrolytes have been reported that possess single-ion transport properties with lithium-ion transference numbers approaching unity. Single-ion polyelectrolyte systems have been successfully developed where the anion or the counterion is effectively tethered to the polymer matrix. 14-16 Further, the use of various anion trappers has been shown to effectively boost the cation transference number. 17-20 These approaches, however,...

Indoor residual spraying (IRS) is used to control visceral leishmaniasis (VL) in India, but it is poorly quality assured. Quality assurance was performed in eight VL endemic districts in Bihar State, India, in 2014. Residual dichlorodiphenyltrichloroethane (DDT) was sampled from walls using Bostik tape discs, and DDT concentrations [grams of active ingredient per square meter (g ai/m 2 )] were determined using HPLC. Pre-IRS surveys were performed in three districts, and post-IRS surveys were performed in eight districts. A 20% threshold above and below the target spray of 1.0 g ai/m 2 was defined as "in range." The entomological assessments were made in four districts in IRS and non-IRS villages. Vector densities were measured: pre-IRS and 1 and 3 mo post-IRS. Insecticide susceptibility to 4% DDT and 0.05% deltamethrin WHO-impregnated papers was determined with wild-caught sand flies. The majority (329 of 360, 91.3%) of pre-IRS samples had residual DDT concentrations of <0.1 g ai/m 2 . The mean residual concentration of DDT post-IRS was 0.37 g ai/m 2 ; 84.9% of walls were undersprayed, 7.4% were sprayed in range, and 7.6% were oversprayed. The abundance of sand flies in IRS and non-IRS villages was significantly different at 1 mo post-IRS only. Sand flies were highly resistant to DDT but susceptible to deltamethrin. The Stockholm Convention, ratified by India in 2006, calls for the complete phasing out of DDT as soon as practical, with limited use in the interim where no viable IRS alternatives exist. Given the poor quality of the DDT-based IRS, ready availability of pyrethroids, and susceptibility profile of Indian sand flies, the continued use of DDT in this IRS program is questionable.leishmaniasis | elimination |

We have studied ionic conductivity and dielectric permittivity of PEO-LiClO4 solid polymer electrolyte plasticized with propylene carbonate. Differential scanning calorimetry and X-ray diffraction studies confirm minimum volume fraction of crystalline phase for the polymer electrolyte with 40 wt. % propylene carbonate. The ionic conductivity exhibits a maximum for the same composition. The temperature dependence of the ionic conductivity has been well interpreted using Vogel-Tamman-Fulcher equation. Ion-ion interactions in the polymer electrolytes have been studied using Raman spectra and the concentrations of free ions, ion-pairs and ion-aggregates have been determined. The ionic conductivity increases due to the increase of free ions with the increase of propylene carbonate content. But for higher content of propylene carbonate, the ionic conductivity decreases due to the increase of concentrations of ion-pairs and ion-aggregates. To get further insights into the ion dynamics, the experimental data for the complex dielectric permittivity have been studied using Havriliak–Negami function. The variation of relaxation time with temperature obtained from this formalism follows Vogel-Tamman-Fulcher equation similar to the ionic conductivity.

Ion conduction and relaxation in PEO-LiTFSI-Al2O3 polymer nanocomposite electrolytes have been studied for different concentrations of Al2O3 nanoparticles. X-ray diffraction and differential scanning calorimetric studies show that the maximum amorphous phase of PEO is observed for PEO-LiTFSI embedded with 5 wt. % Al2O3. The maximum ionic conductivity ∼3.3 × 10−4 S cm−1 has been obtained for this composition. The transmission electron microscopic image shows a distribution of Al2O3 nanoparticles in all compositions with size of &lt;50 nm. The temperature dependence of the ionic conductivity follows Vogel-Tamman-Fulcher nature, indicating a strong coupling between ionic and polymer chain segmental motions. The scaling of the ac conductivity implies that relaxation dynamics follows a common mechanism for different temperatures and Al2O3 concentrations. The imaginary modulus spectra are asymmetric and skewed toward the high frequency sides of the maxima and analyzed using Havriliak-Negami formalism. The temperature dependence of the relaxation time obtained from modulus spectra also exhibits Vogel-Tamman-Fulcher nature. The values of the stretched exponent obtained from Kohlrausch-Williams-Watts fit to the modulus data are fairly low, suggesting highly non-exponential relaxation for all concentrations of Al2O3 in these electrolytes.

Sir2 plays a critical role in AmB resistance by regulating MDR1, ROS concentration and apoptosis-like phenomena and may be a new resistance marker for visceral leishmaniasis.

We report on the synthesis and characterization of a solid-state polymer electrolyte with enhanced lithium transport based on a self-assembled diblock copolymer. The diblock copolymer consists of a poly͑ethylene oxide͒ ͑PEO͒ block and a random copolymer of methyl methacylate ͑MMA͒ and lithium salt of methacrylic acid ͑MAALi͒. Lithium bis͑oxalato͒borate, LiBC 4 O 8 ͑LiBOB͒ was used as salt in the dry electrolyte. Impedance and temperature studies were carried out to characterize the conductivity performance of the electrolyte. The diblock copolymer ͓PEO-b-͑PMMA-ran-PMAALi͔͒ with added LiBOB ͑in the molar ratio ethylene oxide:LiBOB = 3:1͒ was used to form flexible translucent films, which exhibited an average ionic conductivity value of 1.26 ϫ 10 −5 S cm −1 at room temperature ͑21°C͒. Transmission electron microscopy was performed to characterize the morphology of the polymer, and differential scanning calorimetry was carried out to study the thermal properties of the electrolyte.

The growth and survival of intracellular parasites depends on the availability of extracellular nutrients. Deprivation of nutrients viz glucose or amino acid alters redox balance in mammalian cells as well as some lower organisms. To further understand the relationship, the mechanistic role of L-arginine in regulation of redox mediated survival of Leishmania donovani promastigotes was investigated. L-arginine deprivation from the culture medium was found to inhibit cell growth, reduce proliferation and increase L-arginine uptake. Relative expression of enzymes, involved in L-arginine metabolism, which leads to polyamine and trypanothione biosynthesis, were downregulated causing decreased production of polyamines in L-arginine deprived parasites and cell death. The resultant increase in reactive oxygen species (ROS), due to L-arginine deprivation, correlated with increased NADP+/NADPH ratio, decreased superoxide dismutase (SOD) level, increased lipid peroxidation and reduced thiol content. A deficiency of L-arginine triggered phosphatidyl serine externalization, a change in mitochondrial membrane potential, release of intracellular calcium and cytochrome-c. This finally led to DNA damage in Leishmania promastigotes. In summary, the growth and survival of Leishmania depends on the availability of extracellular L-arginine. In its absence the parasite undergoes ROS mediated, caspase-independent apoptosis-like cell death. Therefore, L-arginine metabolism pathway could be a probable target for controlling the growth of Leishmania parasites and disease pathogenesis.