Effect of CdSe quantum dots on hole transport in poly(3-hexylthiophene) thin films

This letter demonstrates the effect of cadmium selenide (CdSe) quantum dots on hole transport in poly(3-hexylthiophene) (P3HT) thin films. Current-voltage characteristics of P3HT and P3HT:CdSe thin films have been studied in the temperature range of 288–85 K, in hole only device configurations, i.e., indium tin oxide (ITO)/poly(ethylene-dioxthiophene):polystyrenesulphonate (PEDOT:PSS)/P3HT/Au and ITO/PEDOT:PSS/P3HT:CdSe/Au. The incorporation of CdSe quantum dots in P3HT results in the enhancement in hole current and switches the transport from dual conduction mechanism, viz., trap and mobility models to only trap model. This is attributed to the reduction in characteristic trap energy from 60 to 32 meV and trap density from 2.5×1018 to 1.7×1018 cm−3

Nicotinic acetylcholine receptor is internalized via a Rac-dependent, dynamin-independent endocytic pathway

Endocytosis of the nicotinic acetylcholine receptor (AChR) is a proposed major mechanism of neuromodulation at neuromuscular junctions and in the pathology of synapses in the central nervous system. We show that binding of the competitive antagonist α-bungarotoxin (αBTX) or antibody-mediated cross-linking induces the internalization of cell surface AChR to late endosomes when expressed heterologously in Chinese hamster ovary cells or endogenously in C2C12 myocytes. Internalization occurs via sequestration of AChR–αBTX complexes in narrow, tubular, surface-connected compartments, which are indicated by differential surface accessibility of fluorescently tagged αBTX–AChR complexes to small and large molecules and real-time total internal reflection fluorescence imaging. Internalization occurs in the absence of clathrin, caveolin, or dynamin but requires actin polymerization. αBTX binding triggers c-Src phosphorylation and subsequently activates the Rho guanosine triphosphatase Rac1. Consequently, inhibition of c-Src kinase activity, Rac1 activity, or actin polymerization inhibits internalization via this unusual endocytic mechanism. This pathway may regulate AChR levels at ligand-gated synapses and in pathological conditions such as the autoimmune disease myasthenia gravis

Spectroscopic, Magnetic and Morphological studies of MgFe2O4 Nanopowder

Spinel type nano ferrite compound MgFe2O4 was synthesized through sol gel technique using metal nitrates as precursors. The phase composition, morphology and elemental analysis of magnesium ferrite (MgFe2O4) were performed by X-ray diffraction, fourier transform infrared, atomic force microscopy, energy dispersive x-ray and scanning electron microscopy, analyses.       The sample's X-ray diffraction pattern verifies the existence of single phase material, with the size of its crystallites estimated to be 39.9 nm. Fourier transform infrared examination supported metal-oxygen vibrations corresponding to tetrahedral and octahedral sites, respectively. From scanning electron microscopy image, grain size obtained about 97.7 nm. Raman spectra of the sample shows five Raman active modes (A1g + Eg + 3F2g), which is compatible with the spinel structure. Magnetic measurement study at room temperature shows a hysteresis loop behaviour with a low saturation magnetization value, 27.192 emu g-1 and a small coercivity value. The optical band gap determined using UV-visible transmittance spectra. Additionally, X-ray photoelectron spectroscopy are used to confirm oxidation states and explore the chemical composition of the sample

Rust (Uromyces viciae-fabae Pers. de-Bary) of Pea (Pisum sativum L.): Present Status and Future Resistance Breeding Opportunities

Uromyces viciae-fabae Pers. de-Bary is an important fungal pathogen causing rust in peas (Pisum sativum L.). It is reported in mild to severe forms from different parts of the world where the pea is grown. Host specificity has been indicated in this pathogen in the field but has not yet been established under controlled conditions. The uredinial states of U. viciae-fabae are infective under temperate and tropical conditions. Aeciospores are infective in the Indian subcontinent. The genetics of rust resistance was reported qualitatively. However, non-hypersensitive resistance responses and more recent studies emphasized the quantitative nature of pea rust resistance. Partial resistance/slow rusting had been described as a durable resistance in peas. Such resistance is of the pre-haustorial type and expressed as longer incubation and latent period, poor infection efficiency, a smaller number of aecial cups/pustules, and lower units of AUDPC (Area Under Disease Progress Curve). Screening techniques dealing with slow rusting should consider growth stages and environment, as both have a significant influence on the disease scores. Our knowledge about the genetics of rust resistance is increasing, and now molecular markers linked with gene/QTLs (Quantitative Trait Loci) of rust resistance have been identified in peas. The mapping efforts conducted in peas came out with some potent markers associated with rust resistance, but they must be validated under multi-location trails before use in the marker-assisted selection of rust resistance in pea breeding programs

The Science Performance of JWST as Characterized in Commissioning

This paper characterizes the actual science performance of the James Webb Space Telescope (JWST), as determined from the six month commissioning period. We summarize the performance of the spacecraft, telescope, science instruments, and ground system, with an emphasis on differences from pre-launch expectations. Commissioning has made clear that JWST is fully capable of achieving the discoveries for which it was built. Moreover, almost across the board, the science performance of JWST is better than expected; in most cases, JWST will go deeper faster than expected. The telescope and instrument suite have demonstrated the sensitivity, stability, image quality, and spectral range that are necessary to transform our understanding of the cosmos through observations spanning from near-earth asteroids to the most distant galaxies.Comment: 5th version as accepted to PASP; 31 pages, 18 figures; https://iopscience.iop.org/article/10.1088/1538-3873/acb29

The effect of hydrostatic pressure on magnetostructural transition in ferromagnetic cobaltite: Pr0.6Sr0.4CoO3

The ambient pressure temperature dependence of the magnetization (M) in P1-xSrxCoO3 series (x = 0.4, 0.5, 0.55 and 0.6) indicates the onset of ferromagnetic ordering at high temperatures (TC = 214-226K) and a step-like anomaly at lower temperatures (TS = 69-120 K). In this report we present the pressure dependence of magnetization and zero-field thermal expansion studies for a representative sample x = 0.4. The step-like anomaly in M(T) around TS = 69 K is accompanied by a pronounced peak in thermal expansion coefficient. The application of hydrostatic pressure of P = 1.16 GPa increases TS by 15 K, which is much larger than the increase of the ferromagnetic Curie temperature (ΔTC = 4 K) under the same pressure. The anomalous increase of TS under pressure is attributed to the occurrence of magnetization rotation at a temperature higher than TS = 69 K triggered by the stabilization of low temperature tetragonal phase at the expense of high temperature orthorhombic phase

Indole<b>-</b>based distinctive chemosensors for ‘naked-eye’ detection of CN and HSO₄⁻, associated with hydrogen-bonded complex and their DFT study

<p>Colorimetric detection of anions (<b>HSO</b>_<b>4</b>^<b>−</b> and <b>CN</b>^<b>−</b>) was achieved via analyte triggered colour changing of the dipodal and tripodal sensors in CH₃CN–H₂O (1:1). The sensors exhibited very sharp visual colour changes and fluorescence quenching–enhancing effect upon addition of the <b>HSO</b>_<b>4</b>^<b>−</b> and <b>CN</b>^<b>−</b>. The large downfield shift of the NH proton signals in ¹H-NMR complexation studies and quantum chemical DFT calculations proved the formation of hydrogen-bonded complexes where no proton transfer mechanism was found.</p> <p>Indole based dipodal and tripodal fluorescence ‘<i>on-off</i>’ chemosensors exhibit a selective colorimetric sensing ability towards HSO₄⁻ and CN⁻ ions. ¹H-NMR study and quantum chemical DFT calculations with MEP diagram proves the formation of hydrogen bonded complexes.</p

Electric field and temperature dependence of hole mobility in electroluminescent PDY 132 polymer thin films

The current density–voltage (J–V) behavior of polymer PDY 132 thin films has been investigated in hole-only device configuration, viz., ITO/poly(ethylene-dioxthiophene):polystyrenesulphonate (PEDOT:PSS)/PDY 132/Au, as a function of polymer (PDY) film thickness (150 nm and 200 nm) and temperature (290–90 K). Hole current density was found to follow two distinct modes of conduction, (i) low electric field region I: ohmic conduction where slope ∼1, and (ii) intermediate and high electric field region II: non ohmic conduction where slope ∼2. Region I has been attributed to the transport of intrinsic background charge carriers while region II has been found to be governed by space charge limited currents (SCLC) with hole mobility strongly dependent on electric field and temperature. The respective hole transport parameters determined from the SCLC regime, μp0 is View the MathML source, μp(0,T) is View the MathML source, and zero field activation energy (Δ0) of 0.48 eV is obtained

ddRAD sequencing based genotyping of six indigenous dairy cattle breeds of India to infer existing genetic diversity and population structure

Abstract The present investigation aimed to identify genome wide SNPs and to carry out diversity and population structure study using ddRAD-seq based genotyping of 58 individuals of six indigenous milch cattle breeds (Bos indicus) such as Sahiwal, Gir, Rathi, Tharparkar, Red Sindhi and Kankrej of India. A high percentage of reads (94.53%) were mapped to the Bos taurus (ARS-UCD1.2) reference genome assembly. Following filtration criteria, a total of 84,027 high quality SNPs were identified across the genome of 6 cattle breeds with the highest number of SNPs observed in Gir (34,743), followed by Red Sindhi (13,092), Kankrej (12,812), Sahiwal (8956), Tharparkar (7356) and Rathi (7068). Most of these SNPs were distributed in the intronic regions (53.87%) followed by intergenic regions (34.94%) while only 1.23% were located in the exonic regions. Together with analysis of nucleotide diversity (π = 0.373), Tajima’s D (D value ranging from − 0.295 to 0.214), observed heterozygosity (HO ranging from 0.464 to 0.551), inbreeding coefficient (FIS ranging from − 0.253 to 0.0513) suggested for the presence of sufficient within breed diversity in the 6 major milch breeds of India. The phylogenetic based structuring, principal component and admixture analysis revealed genetic distinctness as well as purity of almost all of the 6 cattle breeds. Overall, our strategy has successfully identified thousands of high-quality genome wide SNPs that will further enrich the Bos indicus representation basic information about genetic diversity and structure of 6 major Indian milch cattle breeds which should have implications for better management and conservation of valuable indicine cattle diversity

DataSheet1_Phyto-fabrication of silver nanoparticles and their catalytic dye degradation and antifungal efficacy.docx

The biogenic synthesis of silver nanoparticles (AgNPs) and their potent application against dye degradation and phytopathogens are attracting many scientists to nanotechnology. An attempt was made to synthesize silver nanoparticles using Plantago ovata leaf extract and test their effectiveness in removing organic dyes and antifungal activity. In the present study, stable AgNPs were synthesized from 0.1 mM AgNO3 and authenticated by observing the color change from yellow to red-brown, which was confirmed with wavelength UV-Vis spectrophotometer detection. The crystalline nature of the particles was characterized by x-ray diffraction (XRD) patterns. Furthermore, the AgNPs were characterized by high-resolution transmission electron microscope and scanning electron microscope investigations. Atomic force microscopy (AFM) and Raman spectra were also used to confirm the size and structure of the synthesized AgNPs. The elemental analysis and functional groups responsible for the reduction of AgNPs were analyzed by electron dispersive spectroscopy and fourier transform infra-red spectroscopy Fourier transforms infrared, respectively. A new biological approach was taken by breaking down organic dyes such as methylene blue and congo red. The AgNPs effectively inhibit the fungal growth of Alternaria alternata. This could be a significant achievement in the fight against many dynamic pathogens and reduce dye contamination from waste water.</p