University of Rajasthan

About: University of Rajasthan is a education organization based out in Jaipur, India. It is known for research contribution in the topics: Chemical shift & Derivative (chemistry). The organization has 15058 authors who have published 15733 publications receiving 117400 citations. The organization is also known as: Rajasthan University.

Thiol terminated chitosan capped silver nanoparticles for sensitive and selective detection of mercury (II) ions in water

Abstract: In this paper, we report a simple method for the optical detection of environmentally toxic mercury (II) ions (Hg2+) in water using chitosan capped silver nanoparticles (Ch–Ag NPs). The yellow colored aqueous solution of Ch-Ag NPs instantly (10 s) became colorless with addition of Hg2+ ions. Cu2+, and Fe3+ ions also produced colorless solution after 1 min. To overcome the Cu2+ and Fe3+ interference, thiol terminated chitosan was synthesized via amide coupling formation between amine group of chitosan and carboxylic acid group of 3-Mercaptopropanoic acid (3-MPA). The detailed study of selectivity, sensitivity, effect of interfering radicals, and response time confirmed that thiol terminated chitosan capped silver nanoparticles (Mod-Ch-Ag NPs) are highly selective and speedy for Hg2+ ions detection. The limit of detection was found to be 5 ppb. Furthermore, since the change in color with addition of mercury can be observed by naked eye, the developed nanosensor can also be utilized for real field applications. Hydrogel of Mod-Ch–Ag NPs was successfully synthesized and it was also found highly specific for Hg2+ ions. It was observed that separation of Hg2+ ions is also possible by simply changing the pH of the solution containing colorless Hg2+ with Mod-Ch-Ag NPs.

Evidence of Spin-Orbital Angular Momentum Interactions in Relativistic Heavy-Ion Collisions.

Abstract: The first evidence of spin alignment of vector mesons (K0 and ϕ) in heavy-ion collisions at the Large Hadron Collider (LHC) is reported. The spin density matrix element ρ00 is measured at midrapidity (|y| < 0.5) in Pb-Pb collisions at a center-of-mass energy (√sNN) of 2.76 TeV with the ALICE detector. ρ00 values are found to be less than 1=3 (1=3 implies no spin alignment) at low transverse momentum (pT < 2 GeV/c) for K0 and ϕ at a level of 3σ and 2σ, respectively. No significant spin alignment is observed for the K^0_S meson (spin = 0) in Pb-Pb collisions and for the vector mesons in pp collisions. The measured spin alignment is unexpectedly large but qualitatively consistent with the expectation from models which attribute it to a polarization of quarks in the presence of angular momentum in heavy-ion collisions and a subsequent hadronization by the process of recombination.

Silver nanoparticle induced cytotoxicity, oxidative stress, and DNA damage in CHO cells

Abstract: Silver nanoparticles (Ag NPs) are being used increasingly in wound dressings, catheters, and in various household products due to their antimicrobial activity. The present study reports the toxicity evaluation of synthesized and well characterized Ag NPs using Chinese hamster ovary (CHO) cells. The UV–Vis spectroscopy reveals the formation of silver nanoparticles by exhibiting the typical surface plasmon absorption maxima at 408–410 nm. Transmission electron microscopy (TEM) reveals that the average diameter of silver nanoparticles is about 5.0 ± 1.0 nm and that they have spherical shape. Cell visibility and cell viability percentage show dose-dependent cellular toxicity of Ag NPs. The half maximal inhibitory concentration (IC50) for CHO cells is 68.0 ± 2.65 μg/ml after 24 h Ag NPs exposure. Toxicity evaluations, including cellular morphology, mitochondrial function (MTT assay), reactive oxygen species (ROS), and DNA fragmentation assay (Ladder pattern) were assessed in unexposed CHO cells (control) and the cells exposed to Ag NPs concentrations of 15, 30, and 60 μg/ml for 24 h. The findings may assist in the designing of Ag NPs for various applications and provide insights into their toxicity.

Plants obtained from the Khair tree (Acacia catechu Willd.) using mature nodal segments.

Abstract: An in vitro method for obtaining plants of Acacia catechu has been developed using nodal explants from mature `elite' trees growing in the field. Maximum shoot bud development (eight to ten) from a single explant was achieved on Murashige and Skoog (MS) medium supplemented with 6-benzylaminopurine (BAP) (4.0 mg/l) and α-naphthaleneacetic acid (0.5 mg/l). Addition of adenine sulphate (25.0 mg/l), ascorbic acid (20.0 mg/l) and glutamine (150.0 mg/l) to the medium was found beneficial for maximum shoot bud induction. The shoot buds developed into healthy and sturdy shoots on MS medium containing BAP and kinetin at 1.0 mg/l. Excised shoots were rooted on 1/4-strength MS medium with indole-3-acetic acid at 3.0 mg/l and 1.5% sucrose to obtain complete plants.