High Rectification Ratio at Room Temperature in Rhenium(I) Compound

Electrical current rectification is an interesting electronic feature, popularly known as a diode. Achieving a high rectification ratio in a molecular junction has been a long-standing goal in molecular electronics. The present work describes mimicking electrical current rectification with pi-stacked rhenium(I) compound sandwiched between two electrical contacts. Among the two mononuclear rhenium compounds studied here, [Re(CO)4(PPh3){(N)-saccharinate}] (1) and [Re(CO)3(phen){(N)-saccharinate}] (2), the latter show strong pi-pi interactions-induced high rectification ratio of ~ 4000 at 2.0 V at room temperature. Alternating current (AC)-based electrical measurements ensuring AC to DC electrical signal conversion at a frequency f of 1 KHz showing 2 can act as an excellent half-wave rectifier. Asymmetric charge injection barrier height at the electrode/Re(I) interfaces of the devices with a stacking configuration of p++-Si/Re compound31nm(2)/ITO originates the flow of electrical current unidirectionally. The charge transport mechanism governed by thermally activated hopping phenomena, and charge carrier propagation is explained through an energy profile considering the Fermi levels of two electrodes, and the energy of frontier molecular orbitals, HOMO, and LUMO, confirming rectification is of a molecular origin. The present work paves the way to combine different organometallic compounds as circuit elements in nanoelectronic devices to achieve numerous exciting electronic features.Comment: 16 pages, 5 figure

Pros and Cons of Curcumin as Bioactive Phyto-Compound for Effective Management of Insect Pests

Phyto-compounds as insecticides have expanded impetus in recent insect pest management programme owing to health hazards and perpetual toxicity of conservatively applied deleterious insecticides of diverse commercial brands. Turmeric plant produces fleshy rhizomes of bright yellow to orange color in its root system, which are the source of commercially available spice turmeric. Curcumin, a Phytochemical gives yellow colour to turmeric and is used for time immemorial for most of the remedial practices. Curcumin is also used as a spice in foods, as a dye for fleeces and as an ingredient in dietetic supplements.  As root powder, turmeric is used for its flavoring properties as a spice, food preservative and food-coloring agent. Turmeric has a long history of soothing uses as it is accredited with a diversity of imperative valuable properties such as its antioxidant, antibacterial, anti-inflammatory, analgesic and digestive properties respectively. The fresh juice, the aqueous extracts and the essential oil of the plant are endorsed with fascinating pesticidal properties against certain pests of agricultural importance as well as a perceptible repugnant activity against noxious mosquito species.  Results have exposed a pleasurable impending potentiality of turmeric as a natural pesticide for achievable use in current crop protection and thus an exceedingly promising future towards this route, that is, the possibility of effective control of certain pests of agricultural importance with the use of turmeric products as an economical and more effective eco-friendly alternative to chemical pesticides which is by now put into practice

Dielectric and Raman studies of Ba-0.06(Na1/2Bi1/2)(0.94)TiO3-NaNbO3 ceramics

In this work the X-ray diffraction, scanning electron microscopy, Raman and dielectric studies of lead free perovskite (1-x)Ba-0.06(Na1/2Bi1/2)(0.94)TiO3-xNaNbO(3) (0 <= x <= 1.0) ceramics, prepared using a standard solid state reaction method, were investigated. X-ray diffraction studies of all the ceramics suggested the formation of single phase with crystal structure transforming from rhombohedral-tetragonal to orthorhombic symmetry with the increase in NaNbO3 content. Raman spectra also confirmed the formation of solid solution without any new phase. Dielectric studies showed that the phase transition is of diffusive character and diffusivity parameter decreases with increasing NaNbO3 content. The compositional fluctuation was considered to be the main cause of diffusivity

Development of Novel Interspecific Fertile Cytotype (4X) Of \u3cem\u3ePennisetum glaucum\u3c/em\u3e X \u3cem\u3ePennisetum purpureum\u3c/em\u3e Utilizing Modified Ploidy Coupled With Embryo Rescue Technique

Interspecific hybrids of genus Pennisetum (P. glaucum x P. purpureum) is the one of the most popular manmade hybrid. It combines the unique features of both P. glaucum (Pearl millet; Bajra) and P. purpureum (Napier; Elephant grass) species, which makes it more resilient to harsh environments with superior fodder quality. Due to ploidy level variation among the parents, these hybrids are sterile and propagated vegetatively only. To overcome this, attempts were made in the present study by exploring the feasibility of novel tetraploid pearl millet (2n=4x=28; Tetra 1; INGR 09047) developed at IGFRI, as a female parent in crossing program involving different Napier genotypes as male parent. Due to limited crossability and hybrid necrosis issues among countless crosses (\u3e 1000), only 1% seed set was initially recorded that too in shriveled state and the developing embryos were aborted after 10-14 days of pollination and fertilization. To save these, embryo rescue technique was standardized and the developing embryos were dissected out aseptically and rescued after 8-10 days of pollination. Continuous crossing programme along with screening of large tissue culture raised nurseries resulted in development of a novel tetraploid seed producing BN hybrid (TBN-20-15) along with 14 novel sterile tetraploid BN hybrids. Presence of univalent chromosomes leads to sterility while proper pairing between parents of TBN-20-15 hybrid have significant effect on fertility. The fertile hybrid is able to produce \u3e15,000-20,000 seeds throughout the year with 80-90% seed germination ability. Their hybridity was confirmed by morphology, molecular and cytogenetic studies. This fertile tetraploid BN hybrid (TBN-20-15) reported for the first time globally will be very helpful in easy and cost-effective dissemination of this highly potential forage crop to the farmer’s field. It has the potential to be the game changer in biofuel production, grassland rejuvenation programs besides bridging the fodder demand supply deficit

The complex light-curve of the afterglow of GRB071010A

We present and discuss the results of an extensive observational campaign devoted to GRB071010A, a long-duration gamma-ray burst detected by the Swift satellite. This event was followed for almost a month in the optical/near-infrared (NIR) with various telescopes starting from about 2min after the high-energy event. Swift-XRT observations started only later at about 0.4d. The light-curve evolution allows us to single out an initial rising phase with a maximum at about 7min, possibly the afterglow onset in the context of the standard fireball model, which is then followed by a smooth decay interrupted by a sharp rebrightening at about 0.6d. The rebrightening was visible in both the optical/NIR and X-rays and can be interpreted as an episode of discrete energy injection, although various alternatives are possible. A steepening of the afterglow light curve is recorded at about 1d. The entire evolution of the optical/NIR afterglow is consistent with being achromatic. This could be one of the few identified GRB afterglows with an achromatic break in the X-ray through the optical/NIR bands. Polarimetry was also obtained at about 1d, just after the rebrightening and almost coincident with the steepening. This provided a fairly tight upper limit of 0.9% for the polarized-flux fraction.Comment: 11 pages, 3 figures, MNRAS, in pres

The complex light-curve of the afterglow of GRB071010A

We present and discuss the results of an extensive observational campaign devoted to GRB071010A, a long-duration gamma-ray burst detected by the Swift satellite. This event was followed for almost a month in the optical/near-infrared (NIR) with various telescopes starting from about 2min after the high-energy event. Swift-XRT observations started only later at about 0.4d. The light-curve evolution allows us to single out an initial rising phase with a maximum at about 7min, possibly the afterglow onset in the context of the standard fireball model, which is then followed by a smooth decay interrupted by a sharp rebrightening at about 0.6d. The rebrightening was visible in both the optical/NIR and X-rays and can be interpreted as an episode of discrete energy injection, although various alternatives are possible. A steepening of the afterglow light curve is recorded at about 1d. The entire evolution of the optical/NIR afterglow is consistent with being achromatic. This could be one of the few identified GRB afterglows with an achromatic break in the X-ray through the optical/NIR bands. Polarimetry was also obtained at about 1d, just after the rebrightening and almost coincident with the steepening. This provided a fairly tight upper limit of 0.9% for the polarized-flux fraction.Comment: 11 pages, 3 figures, MNRAS, in pres

Purification and Characterization of a Sperm Motility Inhibiting Factor from Caprine Epididymal Plasma

Several studies have been reported on the occurrence of sperm motility inhibiting factors in the male reproductive fluids of different mammalian species, but these proteins have not been adequately purified and characterized. A novel sperm motility inhibiting factor (MIF-II) has been purified from caprine epididymal plasma (EP) by Hydroxylapatite gel adsorption chromatography, DEAE-Cellulose ion-exchange chromatography and chromatofocusing. The MIF-II has been purified to apparent homogeneity and the molecular weight estimated by Sephacryl S-300 gel filtration is 160 kDa. MIF-II is a dimeric protein, made up of two subunits each having a molecular mass of 80 kDa as shown by SDS-PAGE. The isoelectric point of MIF-II is 5.1 as determined by chromatofocusing and isoelectric focusing. It is a heat labile protein and maximal active at the pH 6.9 to 7.5. The sperm motility inhibiting protein factor at 2 µg/ml (12.5 nM) level showed maximal motility-inhibiting activity. The observation that the epididymal plasma factor lowered the intracellular cAMP level of spermatozoa in a concentration-dependent manner suggests that it may block the motility of caprine cauda spermatozoa by interfering the cAMP dependent motility function. The results revealed that the purified protein factor has the potential of sperm motility inhibition and may serve as a vaginal contraceptive. The antibody raised against the MIF-II has the potential for enhancement of forward motility of cauda-spermatozoa. This antibody may thus be useful for solving some of the problems of male infertility due to low sperm motility

Targeting spike glycans to inhibit SARS-CoV2 viral entry

SARS-CoV-2 spike harbors glycans which function as ligands for lectins. Therefore, it should be possible to exploit lectins to target SARS-CoV-2 and inhibit cellular entry by binding glycans on the spike protein. Burkholderia oklahomensis agglutinin (BOA) is an antiviral lectin that interacts with viral glycoproteins via N-linked high mannose glycans. Here, we show that BOA binds to the spike protein and is a potent inhibitor of SARS-CoV-2 viral entry at nanomolar concentrations. Using a variety of biophysical approaches, we demonstrate that the interaction is avidity driven and that BOA cross-links the spike protein into soluble aggregates. Furthermore, using virus neutralization assays, we demonstrate that BOA effectively inhibits all tested variants of concern as well as SARS-CoV 2003, establishing that multivalent glycan-targeting molecules have the potential to act as pan-coronavirus inhibitors