Polymer network as a template for control of photoconductivity of a liquid crystal semiconductor

We report a novel method of confining a photoconducting liquid crystalline material using a polymer templating approach. The attractive feature of this approach is that the magnitude of the photocurrent of the photoconducting material does not diminish, i.e. it is unaltered by the polymer matrix. The results are compared with another method of encapsulation that was recently reported and wherein the photoconductivity decreases upon having the photoconducting material in the polymer matrix. The difference in the behaviour between the two methods is explained using a nanophase segregation model. The method described is particularly suitable for creating patterned photoconductors.     

Molecular activities and ligand-binding specificities of StAR-related lipid transfer domains: exploring integrated in silico methods and ensemble-docking approaches

In this study, cholesterol biotransformation gene-set of human steroidogenic acute regulatory protein-related lipid transfer (START) domains were evaluated from high-throughput gene screening approaches. It was shown that STARD1, STARD3 and STARD4 proteins are better effective transporters of cholesterol than STARD5 and STARD6 domains. Docking studies show a strong agreement with gene ontology enrichment data. According to both complementary strategies, it was found that only STARD1, STARD3 and STARD4 are potentially involved in cholesterol biotransformation in mitochondria through Ω1-loop of C-terminal α4-helical domain. Ensemble docking assessment for a set of selected chemicals of protein–chemical networks has shown possible binding probabilities with START domains. Among those, reproductive toxicity evoked drugs (mifepristone), insecticides (rotenone), tobacco pulmonary carcinogens (benzo(a)pyrene) and endocrine disruptor chemicals (EDCs) including perfluorooctanesulfonic acid (PFOS) and aflatoxin B₁ (AFB₁) potentially bound with novel hotspot residues of the α4-helical domain. Compound representation space and clustering approaches reveal that the START proteins show more sensitivity with these lead scaffolds, so they could provide probable barrier assets in cholesterol and steroidogenic acute regulatory (StAR) binding and leads adverse consequences in steroidogenesis. These findings indicate potential START domains and their binding levels with toxic chemicals; sorted viewpoints could be useful as a promising way to identify chemicals with related steroidogenisis impacts on human health.     

On biunitary permutation matrices and some subfactors of index 9

This paper is devoted to a study of the subfactors arising from vertex models constructed out of `biunitary' matrices which happen to be permutation matrices. After a discussion on the computation of the higher relative commutants of the associated subfactor (in the members of the tower of Jones' basic construction), we discuss the principal graphs of these subfactors for small sizes of the vertex model. Of the 18 possibly inequivalent such biunitary matrices when , we compute the principal graphs completely in 15 cases, all of which turn out to be finite. In the last section, we prove that two of the three remaining cases lead to subfactors of infinite depth and discuss their principal graphs.

     

Cytotoxic copper(II) complex of tripyridoquinoxaline with DNA hydrolase activity

A monomeric copper(II) complex, [Cu(tpq)₂(H₂O)₂](ClO₄)₂, (tpq = tripyridoquinoxaline), has been synthesized and characterized spectroscopically. This complex has been found to bind DNA intercalatively and the DNA binding constant, K_b, for this complex has been determined from absorption measurements and was found to be (5.7 ± 0.3) × 10³ M⁻¹. This complex successfully promotes hydrolytic cleavage of plasmid DNA, producing single and double DNA strand breaks in the absence of any added cofactor. The amount of conversion of the supercoiled form of plasmid to the nicked circular form depends on the concentration of the copper complex as well as the duration of the incubation of the complex with DNA. The rate of conversion of SC to NC has been determined to be 2.65 × 10⁻⁴ s⁻¹ at pH 7.2 in the presence of 80 μM of the complex. This complex has also been shown to be cytotoxic towards A549 lung adenocarcinoma cells. This complex has been shown to bring about apoptosis of the cancerous A549 cell line.     

Development and investigation of the flexible hydrogen sensor based on ZnO-decorated Sb2O3 nanobelts

Hydrogen is regarded as the next-gen fuel for vehicles to avoid the emission of toxic gases, which needs a continuous monitoring of the concentration level. In the design of the H₂ sensor, especially of flexible type, a sensing layer will be blended, which affects the sensing performance of the device. Based on this concern, the present investigation is carried out to understand the effect of the bending angle toward the sensing performance of bare and ZnO (n-type)-decorated Sb₂O₃ (p-type) nanobelt–based sensors for hydrogen gas. The sensing element was prepared by the thermal chemical vapor deposition followed by the drop-casting method. Furthermore, the role of the zinc precursor (molar concentration—1 M–3 M) on the preparation of ZnO-decorated Sb₂O₃ nanobelts was studied. Various techniques were used to confirm the formation of ZnO-decorated nanobelts such as X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDAX), and Fourier transform infrared spectroscopy (FTIR). From these analyses, 1 M concentration of the zinc precursor shows uniform distribution of nanoparticles over the surface of Sb₂O₃ nanobelts. However, agglomeration was observed when the concentration of the zinc precursor increases from 1 M to 3 M. Later, the prepared nanobelts were deposited on the OverHead Projector (OHP) sheet by the doctor blade method for sensing hydrogen gas at 100 °C at a concentration of 1000–3000 ppm. In addition to it, the effect of the substrate bending angle (0°, 45°, 60°, and 90°) was analyzed at a fixed concentration of H₂ gas (1000 ppm). From this study, it is clear that the highest sensing response was achieved for 1 M decorated nanobelts compared with bare as well as other concentrations because of uniform distribution of nanoparticles on the surface of nanobelts. Moreover, the prepared sample demonstrates better sensing performance with the bending of substrates, which suggests that the prepared sensor could be used for flexible electronic devices. The prepared nanobelts show a good H₂ gas–sensing response even with bending of the substrates. The work suggests that the prepared sensor is applicable for flexible electronic devices.     

“Seems Bad Turns Good” – traces of precursor in dicationic ionic liquid lead to analytical application

Research on Chemical Intermediates - We explored a geminal dicationic ionic liquid (DCIL), 1′-(propane-1,3-diyl)bis(4-aminopyridin-1-ium) dibromide, [C3(Amp)2][Br]2, as a fluorescent probe...     

CopperII phthalocyanine as an efficient and reusable catalyst for the N-arylation of nitrogen containing heterocycles

Copper phthalocyanine (Cu^IIPc) was found to be an efficient catalyst for the catalyzed N-arylation of NH heterocycles with aryl iodides and bromides under mild reaction conditions. A variety of hindered and functionalized NH heterocycles and aryl halides were successfully used as the substrates for the given catalytic reaction and were transformed in good to excellent yields.     

Solar neutrino problem in light of super-Kamiokande data

I discuss the status of the accepted solutions to the solar neutrino problem in light of the super-Kamiokande data.