Application of fission track technique for estimation of uranium concentration in drinking waters of Punjab

Drinking water samples were collected from four different districts, namely Bhatinda, Mansa, Faridkot and Firozpur, of Punjab for ascertaining the U(nat.) concentrations. All samples were preserved, processed and analyzed by laser fluorimetry (LF). To ensure accuracy of the data obtained by LF, few samples (10 nos) from each district were analyzed by alpha spectrometry as well as by fission track analysis (FTA) technique. For FTA technique few μl of water sample was transferred to polythene tube, lexan detector was immersed in it and the other end of the tube was also heat-sealed. Two samples and one uranium standard were irradiated in DHRUVA reactor. Irradiated detectors were chemically etched and tracks counted using an optical microscope. Uranium concentrations in samples ranged from 3.2 to 60.5 ppb and were comparable with those observed by LF.     

Heparin Gold Nanoparticles as a Colorimetric Probe for Cardiac Troponin I Detection

Journal of Analytical Chemistry - We report a simple, visual detection strategy for cardiac biomarker, troponin I (cTnI), a promising indicator of cardiac disease based on heparin gold...     

Minimum Degrees of Minimal Ramsey Graphs for Almost‐Cliques

For graphs F and H, we say F is Ramsey for H if every 2‐coloring of the edges of F contains a monochromatic copy of H. The graph F is Ramsey H‐minimal if F is Ramsey for H and there is no proper subgraph of F so that is Ramsey for H. Burr et al. defined to be the minimum degree of F over all Ramsey H‐minimal graphs F. Define to be a graph on vertices consisting of a complete graph on t vertices and one additional vertex of degree d. We show that for all values ; it was previously known that , so it is surprising that is much smaller. We also make some further progress on some sparser graphs. Fox and Lin observed that for all graphs H, where is the minimum degree of H; Szabó et al. investigated which graphs have this property and conjectured that all bipartite graphs H without isolated vertices satisfy . Fox et al. further conjectured that all connected triangle‐free graphs with at least two vertices satisfy this property. We show that d‐regular 3‐connected triangle‐free graphs H, with one extra technical constraint, satisfy ; the extra constraint is that H has a vertex v so that if one removes v and its neighborhood from H, the remainder is connected.     

Facile expeditious one-pot synthesis and antifungal evaluation of disubstituted 1,2,3-triazole with two amide linkages

A library of twenty five amide linked 1,4-disubstituted 1,2,3-triazoles have been prepared through a facile expeditious synthetic protocol involving Cu(I) mediated cyclization of N-(2-methylbut-3-yn-2-yl)aromatic amides and in situ generated 2-azido-N-substituted propanamides. Structures of newly synthesized compounds (5a–5y) were confirmed by analytical techniques, such as FTIR, ¹H NMR, ¹³C NMR, and HRMS. In vitro antifungal activity was also examined against two fungal strains Candida albicans and Aspergillus niger by serial dilution method. The compounds 5?m and 5w exhibited appreciable potent activity.     

Microwave-assisted synthesis of pyrazolo[1,5-c]quinazolines and their derivatives

Microwave accelerated and expedited cyclocondensation reactions of 2-(3-aryl-1H-pyrazol-5-yl)anilines (4) with diverse aryl aldehydes/triethyl orthoformate in water/MeCN (route D) and internal cyclocondensation and aromatization of 5-(2-aminophenyl)-4,5-dihydro-3-arylpyrazole-1-carbaldehyde (7) under MeOH (route E) for the synthesis of a series of pyrazolo[1,5-c]quinazolines and their derivatives (1a–1q) are reported.     

An experimental and theoretical reinvestigation of the Michael addition of primary and secondary amines to dimethyl acetylenedicarboxylate

Theoretical calculations of the Michael addition of diethylamine, pyrrolidine, and benzylamine to DMAD at the DFT (B3LYP/6-31+G^∗) level indicate that the reaction follows a stepwise mechanism via a zwitterionic intermediate. The reactions have low activation barriers, 13–15 kcal mol⁻¹ and are exothermic, ΔH° = −29 to −44 kcal mol⁻¹. The detailed investigation of the reaction of benzylamine with DMAD reveals participation of the reactant-, transition structure-, and the product-complexes and that the 1,3-prototropic shift occurs through the benzylamine molecule. It also predicts formation of dimethyl 2-(N-benzylimino)butane-1,4-dicarboxylate as one of the products, which has been duly isolated and characterized experimentally.     

α-Glucosidase Inhibition and Antioxidant Properties of Streptomyces sp.: In Vitro

Streptomyces strain isolated from the soil sediment was studied for its in vitro α-glucosidase and antioxidant properties. Morphological characterization and 16S rRNA partial gene sequencing were carried out to confirm that the strain Loyola AR1 belongs to genus Streptomyces sp. Modified nutrient glucose broth was used as the basal medium for growth and metabolites production. Ethyl acetate extract of Loyola AR1 (EA-Loyola AR1) showed 50 % α-glucosidase inhibition at the concentration of 860.50?±?2.68 μg/ml. Antioxidant properties such as total phenolic content of EA-Loyola AR1 was 176.83?±?1.17 mg of catechol equivalents/g extracts. EA-Loyola AR1 showed significant scavenging activity on 2,2-diphenyl-picrylhydrazyl (50 % inhibition (IC₅₀), 750.50?±?1.61 μg/ml), hydroxyl (IC₅₀, 690.20?±?2.38 μg/ml), nitric oxide (IC₅₀, 850.50?±?1.77 μg/ml), and superoxide (IC₅₀, 880.08?±?1.80 μg/ml) radicals, as well as reducing power. EA-Loyola AR1 showed strong suppressive effect on lipid peroxidation (IC₅₀, 670.50?±?2.52 μg/ml). Antioxidants of β-carotene linoleate model system reveals significantly lower than butylated hydroxyanisole.     

Total Synthesis of Antitumor Antibiotic Derhodinosylurdamycin A

The first total synthesis of derhodinosylurdamycin A, an angucycline antitumor antibiotic, has been described. The synthesis features a Hauser annulation followed by pinacol coupling to construct the tetracyclic angular aglycon, a Stille coupling of glycal stannane and tetracyclic aryliodide followed by stereoselective reduction to afford the 2‐deoxy β‐C‐arylglycoside, and a late‐stage stereoselective glycosylation for the preparation of derhodinosylurdamycin A. This synthetic strategy should be amenable to the chemical synthesis of analogs of derhodinosylurdamycin A bearing diverse 2‐deoxy sugar subunits for structure and activity relationship studies.     

Potentiostatic Electrochemical Preparation of Bismuth Nanoribbons and its Application in Biologically Poisoning Lead and Cadmium Heavy Metal Ions Detection

A simple and elegant electrochemical potentiostatic method has been described for the preparation of highly stable and electrocatalytically active bismuth nanoribbons (BiNRs). The average length and width of the BiNRs were of 100±50 nm and 10±5 µm, respectively. Here, disodium ethylene diamine tetraacetate was employed as a scaffold for the growth of BiNRs. The formation of BiNRs was confirmed by surface morphological, elemental and cyclic voltammetric analyses. The BiNRs exhibited excellent electrocatalytic ability in detecting biologically poisoning heavy metal ions such as lead and cadmium. The described BiNRs based sensor presents good linear dependence on lead and cadmium ions in the concentration range of 1–50 µg/L for both metal ions with a detection limit of 0.104 µg/L for lead and 0.145 µg/L for cadmium.