Rajesh Kumar

Bio: Rajesh Kumar is an academic researcher from Banaras Hindu University. The author has contributed to research in topics: Grafting & Xanthan gum. The author has an hindex of 16, co-authored 56 publications receiving 702 citations. Previous affiliations of Rajesh Kumar include Noida Institute of Engineering and Technology & Jodhpur National University.

Prediction and validation of gold nanoparticles (GNPs) on plant growth promoting rhizobacteria (PGPR): a step toward development of nano-biofertilizers

Abstract: Several soil microbes are present in the rhizosphere zone, especially plant growth promoting rhizobacteria (PGPR), which are best known for their plant growth promoting activities. The present study reflects the effect of gold nanoparticles (GNPs) at various concentrations on the growth of PGPR. GNPs were synthesized chemically, by reduction of HAuCl 4, and further characterized by UV-Vis spectroscopy, X-ray diffraction technique (XRD), and transmission electron microscopy (TEM), etc. The impact of GNPs on PGPR was investigated by Clinical Laboratory Standards Institute (CLSI) recommended Broth-Microdilution technique against four selected PGPR viz., Pseudomonas fluorescens, Bacillus subtilis, Paenibacillus elgii, and Pseudomonas putida. Neither accelerating nor reducing impact was observed in P. putida due to GNPs. On the contrary, significant increase was observed in the case of P. fluorescens, P. elgii, and B. subtilis, and hence, GNPs can be exploited as nano-biofertilizers.

Detoxification and Tolerance of Heavy Metals in Plants

Abstract: Plant growth and metabolisms are regulated by some heavy metals found in Earth's crust because they are active constituents of various enzymes. However, their increased concentration may lead to different toxic effects, inhibiting plant growth and development. There are some plants that are capable of surviving in the presence of heavy metals, apparently by adapting the mechanism that involved in common homeostasis as well as removal of metal ions. Plants have diverse mechanisms for metal detoxification, enabling them to tolerate heavy metal stress. The defense systems against heavy metal stress include mycorrhizae, cellular exudates, plasma membrane, heat shock proteins, phytochelatins (PCs), metallothioneins (MTs), organic acids, and amino acids. All the mechanism involved the tolerance of heavy metal concentration at cellular level to avoid the negative impacts. Extracellular plants include roles for mycorrhizae and extracellular exudates in the plasma membrane either by dropping by absorption of heavy metal or by inducing the efflux pumping of metal ions. On the other hand, intracellularly heat shock proteins, MTs, organic acids, amino acids, and PCs also play a vital role in tolerance of different heavy metals. Few metal transporters have been identified in the past few years that actively participate in tolerance of metal specificity. Enhanced application of molecular genetics has shown their eminent contribution in understanding the mechanism of heavy metal tolerance in plants.

Biochemistry of oxidative stress

Abstract: The terms 'antioxidant', 'oxidative stress' and 'oxidative damage' are widely used but rarely defined. This brief review attempts to define them and to examine the ways in which oxidative stress and oxidative damage can affect cell behaviour both in vivo and in cell culture, using cancer as an example.

Transition probability from the ground to the first-excited 2^+ state of even-even nuclides

Abstract: Adopted values for the reduced electric quadrupole transition probability, B(E2)↑, from the ground state to the first-excited 2+ state of even–even nuclides are given in Table I. Values of τ, the mean life of the 2+ state; E, the energy; and β, the quadrupole deformation parameter, are also listed there. The ratio of β to the value expected from the single-particle model is presented. The intrinsic quadrupole moment, Q0, is deduced from the B(E2)↑ value. The product E×B(E2)↑ is expressed as a percentage of the energy-weighted total and isoscalar E2 sum-rule strengths. Table II presents the data on which Table I is based, namely the experimental results for B(E2)↑ values with quoted uncertainties. Information is also given on the quantity measured and the method used. The literature has been covered to November 2000. The adopted B(E2)↑ values are compared in Table III with the values given by systematics and by various theoretical models. Predictions of unmeasured B(E2)↑ values are also given in Table III.

RAFTing down under: Tales of missing radicals, fancy architectures, and mysterious holes

Abstract: This highlight describes recent developments in reversible addition-fragmentation transfer (RAFT) polymerization. Succinct coverage of the RAFT mechanism is supplemented by details of synthetic methodologies for making a wide range of architectures ranging from stars to combs, microgels, and blocks. In addition, RAFT reactions in different media such as emulsion and ionic liquids receive attention. Finally, a specific example of a novel material design is briefly introduced, whereas polymers prepared via RAFT are adopted for microporous/honeycomb membrane design.