Banaras Hindu University

About: Banaras Hindu University is a education organization based out in Varanasi, Uttar Pradesh, India. It is known for research contribution in the topics: Population & Catalysis. The organization has 11858 authors who have published 23917 publications receiving 464677 citations. The organization is also known as: Kashi Hindu Vishvavidyalay & Benares Hindu University.

Fighting against Leishmaniasis: search of alkaloids as future true potential anti-Leishmanial agents.

Abstract: Leishmaniasis, a group of tropical diseases caused by protozoan parasites of genus Leishmania, is a major health problem worldwide that affects millions of people especially in the developing nations. Generic pentavalent antimonials have been the mainstay for therapy in the endemic regions due to efficacy and cost effectiveness, but the growing incidence of their resistance has seriously hampered their use. In many cases the drugs employed for the treatment are toxic, marginally effective, given by injection and, compromised by the development of resistance. Therefore, the development of new mechanism based safe, effective and affordable chemotherapeutic agents to fight leishmaniasis would be an urgent priority research. The recent researches focused on natural products have shown a wise way to get a true and potentially rich source of drug candidates against leishmaniasis, where alkaloids have been found more effective. The present review briefly illustrates an account on current status of leishmaniasis, life cycle of parasites and biology, synergy of the disease with HIV, therapeutic options available to cure this disease and, highlights why natural products especially alkaloids as folk medicines are so important? Additionally, the outlines for the leishmanicidal activities of various alkaloids including indole, quinoline, isoquinoline, pyrimidine-beta-carboline, steroidal and diterpene alkaloids from various plants as well as alkaloids from marine sources have been provided with their mechanistic studies.

Electrochemical genosensor based on graphene oxide modified iron oxide–chitosan hybrid nanocomposite for pathogen detection

Abstract: In this report, a nucleic acid sensor has been fabricated via covalent immobilization of Escherichia coli O157:H7 ( E. coli ) specific probe oligonucleotide sequence, onto graphene oxide modified iron oxide–chitosan hybrid nanocomposite (GIOCh) film. The size of the GIOCh, as determined by dynamic light scattering and TEM, varies from 350 to 300 nm, while the zeta potential for the composite remains near 60 mV at pH 4.0. The prepared GIOCh are electrophoretically deposited onto indium tin oxide (ITO) coated glass substrate, used as cathode, while parallel platinum plate is used as counter electrode. The pDNA immobilized onto GIOCh/ITO electrode has been characterized using scanning electron microscopy; contact angle and Fourier transform infrared spectroscopy. Further, the electrochemical response studies carried out using electrochemical impedance spectroscopy reveals that this nucleic acid sensor exhibits a linear response to complementary DNA in the concentration range of 10 −6 –10 −14 M with a detection limit of 1 × 10 −14 M. Under optimal conditions, this biosensor is found to retain about 90% of the initial activity after 6 cycles of use.

Influence of modified processing on structure and properties of hot isostatically pressed superalloy Inconel 718

Abstract: Inert gas atomized (IGA) superalloy Inconel 718 powder was consolidated by hot isostatic pressing (HIPing) at 1200 °C under 120 MPa pressure for 3 h. The HIPed alloy heat treated as per the aerospace materials specification (AMS) 5662J standard schedule, viz. solution treatment (ST) at 980 °C for 1 h/water quenching (WQ) to room temperature (RT) and a two-step ageing treatment (AT) at 720 °C for 8 h/furnace cooling (FC) at 55 °C h −1 to 620 °C and holding at 620 °C for 8 h and air cooling (AC) to room temperature has exhibited the yield strength (YS) and ultimate tensile strength (UTS) comparable to that of the conventionally processed (forged and heat treated) IN 718. However, its ductility and stress rupture properties at 650 °C were found to be poor due to the presence of prior particle boundary (PPB) networks decorated with highly stable oxides (Al 2 O 3 and TiO 2 ) and brittle MC (Nb, Ti)C carbides. To mitigate this problem, the HIPed alloy was subjected to solution treatment at 1270 °C for 1 h followed by re-HIPing at 1100 °C/130 MPa/3 h before heat-treating it as per AMS 5662J standard schedule. Optical and scanning electron microscopy (SEM) of the alloy processed under modified HIPing and heat treatment conditions have shown the dissolution of MC-carbides, breaking up of PPB networks and formation of equiaxed grains with an average diameter of about 50 μm. Transmission electron microscopy (TEM) of this alloy has revealed uniform distribution of γ″ and γ′ strengthening precipitates in the γ-matrix and the presence of δ(Ni 3 Nb) phase as well as very fine oxide particles near the grain boundaries. The tensile properties of the alloy processed under modified conditions have shown quite satisfactory levels of YS and UTS combined with a significantly improved elongation (EL) values at room temperature (19.5%) and at 650 °C (8.0%). The improvement in alloy ductility was found to correlate well with the fractography of the tensile tested specimens, which showed the predominance of transgranular fracture with fine dimples at room temperature and fine dimples together with the particle boundary facets at 650 °C. The stress rupture properties of modified processed alloy at 650 °C and at a stress level of 690 MPa have shown a vastly improved rupture life of 80 h combined with 5% ductility. The improvement in tensile and stress rupture properties accomplished by the modified processing makes it possible to explore the near net shape capability of HIP technology to its full potential in the development of alloy 718 components.