2014

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A dual-ion imprinted polymer embedded in sol-gel matrix for the ultra trace simultaneous analysis of cadmium and copper
(Elsevier B.V., 2014) Bali Prasad, Bhim; Jauhari, Darshika; Verma, Archana
In simultaneous determination of group of elements, there are inter-metallic interactions which result in a non-linear relationship between the peak current and ionic concentration for each of the element, at bare (unmodified) electrode. To resolve this problem, we have resorted, for the first time, to develop a modified pencil graphite electrode using a typical ion imprinted polymer network (dual-ion imprinted polymer embedded in sol-gel matrix (inorganic-organic hybrid nano-material)) for the simultaneous analysis of a binary mixture of Cd(II) and Cu(II) ions, without any complication of inter-metallic interactions and competitive bindings, in real samples. The adequate resolution of differential pulse anodic stripping voltammetry peaks by 725 mV (cf, 615 mV with unmodified electrode), without any cross-reactivity and the stringent detection limits as low as, 0.050 and 0.034 ng mL-1 (S/N=3) for Cd(II) and Cu(II) ions, respectively by the proposed sensor can be considered useful for the primitive diagnosis of several chronic diseases in clinical settings. © 2013 Elsevier B.V.
Multifaceted half-sandwich arene-ruthenium complexes: Interactions with biomolecules, photoactivation, and multinuclearity approach
(2014) Singh, Sanjay Kumar; Pandey, Daya Shankar
Biological properties of the arene-ruthenium complexes have attracted substantial current interest. Their activity is appreciably defined and controlled by the arene moieties, organic ligands and the metal center. In this review, we discuss the interaction of arene-ruthenium complexes with significant biomolecular targets (DNA and enzymes). Principally, active complexes may interact with the biomolecular targets DNA or nucleobases either by direct coordination facilitated by aquation of the complex or by intercalation/stacking of the pendant planar part of the complex, usually from the planar ancillary ligands or arenes with extended rings, between the DNA base pairs. On the other hand, kinetically inert metal complexes can also provide a potential tool (as enzyme inhibitors) for the targeting of important biomolecules (other than DNA), such as protein kinases. At the same time, coordination with a metal facilitates the outreach of the organic molecules in the intracellular region. This review also highlights the photodriven activation of arene-ruthenium complexes, important metal-drug interactions and the potential of multinuclear scaffolds as important drug candidates (e.g., metallodendrimers) and drug carriers (e.g. metallacages) for targeted delivery and activity. © 2014 The Royal Society of Chemistry.
Synthesis and characterization of diorganolead(IV) bis-thiocarboxylate and its application as a molecular precursor of lead sulfide
(Elsevier S.A., 2014) Nayak, Mousumi; Bhattacharya, Subrato
Diphenyllead(IV) bis-thiobenzoate was synthesized by a reaction of diphenyllead dichloride in THF medium. The molecule has been characterized by spectral and single crystal X-ray diffraction analysis. Bonding of the thiocarboxylate ligand is primarily through S atom, however, Pb-O distance indicated the existence of significant PbâO interaction. Bonding features have been explained on the basis of DFT calculations. NBO analysis revealed significant second order perturbation. Electronic transitions have been calculated by TD DFT method and the results are consistent with the experimental spectrum. DSC study has been carried out to measure the heat of fusion of the compound. Room temperature hydrolysis and thermal decomposition reactions have been carried out on the compound under different conditions. The thermally decomposed product was characterized as lead sulfide by powder X-ray diffraction and transmission electron microscopic studies. © 2013 Elsevier B.V. All rights reserved.
Ultraviolet-B induced changes in morphological, physiological and biochemical parameters of two cultivars of pea (Pisum sativum L.)
(2014) Choudhary, Krishna Kumar; Agrawal, S.B.
Increase in perception of solar ultraviolet-B (UV-B) radiation on Earth's surface due to anthropogenic activities has potential in causing detrimental effects on plants. The present study was performed to evaluate the effect of elevated UV-B on Pisum sativum L., a leguminous plant with emphasis on nitrogen metabolism, flavonoids and hormonal changes. Elevated UV-B (ambient+7.2kJm-2 day-1) negatively affected the growth, biomass, yield and its quality by generating oxidative stress directly or due to elevation of salicylic acid in two cultivars with higher magnitude being observed in HUP-2 as compared to HUDP-15. The increased accumulation of flavonoids (quercetin and kaempferol) under elevated UV-B neither provided sufficient protection to the photosynthetic machinery nor helped in elevation of biological nitrogen fixation. Nitrogen fixation and its assimilation were negatively affected under elevated UV-B as observed by the decline in nitrogenase, nitrate reductase, nitrite reductase activities and leghaemoglobin contents. Higher accumulation of salicylic acid in HUP-2 might be associated with its higher degree of sensitivity against UV-B, while higher induction of jasmonic acid and antioxidative enzymes (superoxide dismutase, catalase and ascorbate peroxidase activities) provided resistance to HUDP-15 against applied stress vis-a-vis exhibited less reduction in biomass, yield and quality of produce. © 2013 Elsevier Inc.
Structural diversity in heteroleptic dipyrrinato copper(II) complexes
(Elsevier S.A., 2014) Gupta, Rakesh Kumar; Pandey, Rampal; Kumar, Amit; Ramanujachary, K.V.; Lofland, Samuel E.; Pandey, Daya Shankar
Synthesis and characterization of the heteroleptic dipyrrinato complexes [Cu2(2-pcdpm)2(acac)2] (1), [Cu 2(2-pcdpm)2(hfacac)2] (2), [Cu 3(4-OHdpm)2(acac)4] (3), [Cu 3(4-OHdpm)2(hfacac)4] (4), [Cu 2(3-OHdpm)(acac)3] (5), [Cu2(3-OHdpm)(hfacac) 3] (6), [Cu(2-OHdpm)(acac)] (7) and [Cu(2-OHdpm)(hfacac)] (8) (acac = acetylacetone; hfacac = hexafluoroacetylacetone; 2-pcdpm = 4-(2-methoxypyridyl) phenyldipyrromethene; 3-pcdpm = 4-(3-methoxypyridyl)phenyldipyrromethene; 4-pcdpm = 4-(4-methoxypyridyl)phenyldipyrromethene; 4-/3-/2-OHdpm = 4-/3-/(2-hydroxyphenyl)dipyrromethene) have been described. The complexes 1-8 have been characterized by elemental analyses, ESI-MS, IR, UV-Vis, EPR and electrochemical (CV and DPV) studies. Electronic absorption spectra of 1-8 clearly suggested that position of the absorption bands depend on the nuclearity and coordination geometry about the copper(II) centres. Structures of 1, 2, 3 and 7 have been determined by X-ray single crystal analyses. The spectral and structural studies revealed that copper(II) in 1 and 2 adopted square pyramidal geometry, whereas in 7 a square planar geometry. On the other hand in trinuclear complex 3 one copper(II) adopted square planar, while other two square pyramidal geometry. In their cyclic voltammograms, 1-6 exhibited an irreversible oxidation and two reduction waves whereas 7 and 8 displayed one oxidation and reduction wave. Variable temperature magnetic susceptibility measurements suggested paramagnetic nature of the complexes 1-3. The X-ray photoelectron spectroscopic (XPS) studies indicated that copper(II) centres in complex 3 are present in two different coordination environments. Room temperature EPR studies on 1-8 (g
Nanodiamonds activate blood platelets and induce thromboembolism
(Future Medicine Ltd., 2014) Kumari, Sharda; Singh, Manoj K; Singh, Sunil K; Grácio, José Ja; Dash, Debabrata
Aim: Nanodiamonds (NDs) have been evaluated for a wide range of biomedical applications. Thus, thorough investigation of the biocompatibility of NDs has become a research priority. Platelets are highly sensitive and are one of the most abundant cell types found in blood. They have a central role in hemostasis and arterial thrombosis. In this study, we aim to investigate the direct and acute effects of carboxylated NDs on platelet function. Methods: In this study, pro-coagulant parameters such as platelet aggregability, intracellular Ca 2+ flux, mitochondrial transmembrane potential (ΔΨ m), generation of reactive oxygen species, surface exposure of phosphatidylserine, electron microscopy, cell viability assay and in vivo thromboembolism were analyzed in great detail. Results: Carboxylated NDs evoked significant activation of human platelets. When administered intravenously in mice, NDs were found to induce widespread pulmonary thromboembolism, indicating the remarkable thrombogenic potential of this nanomaterial. Conclusion: Our findings raise concerns regarding the putative biomedical applications of NDs pertaining to diagnostics and therapeutics, and their toxicity and prothrombotic properties should be critically evaluated. Original submitted 15 June 2012; Revised submitted 22 January 2013; Published online 30 April 201. © 2014 Future Medicine Ltd.
Enhanced luminescence of CaMoO4:Eu by core@shell formation and its hyperthermia study after hybrid formation with Fe3O4: Cytotoxicity assessment on human liver cancer cells and mesenchymal stem cells
(2014) Parchur, A.K.; Ansari, A.A.; Singh, B.P.; Hasan, T.N.; Syed, N.A.; Rai, S.B.; Ningthoujam, R.S.
Highly water dispersible Eu3+ doped CaMoO4 nanoparticles (core) covered by CaMoO4 (shell) have been prepared using the polyol method. Significant enhancement in luminescence intensity by core@shell formation is observed due to the decrease of non-radiative rate arising from surface/defect of particles. Effect of 266 nm laser excitation (Mo-O charge transfer band) on the asymmetric ratio (A21 = intensity ratio of electric to magnetic dipole transitions) has been studied and compared with a xenon lamp source. Luminescence intensity increases with the increase of power at 532 nm laser excitation. In order to explore materials, which can show dual functionalities such as luminescence as well as magnetic properties (magnetization of ∼14.2 emu g-1), water dispersible Fe 3O4-CaMoO4:Eu hybrid magnetic nanoparticles (MN) have been prepared. This shows good heating ability up to ∼42 °C (hyperthermia) and luminescence in the red region (∼612 nm), which is in a biological window (optical imaging). Biocompatibility of the synthesized Fe 3O4-CaMoO4:Eu hybrid magnetic nanoparticles has been evaluated in vitro by assessing their cytotoxicity on human liver cancer cells (HepG2 cells) and hTERT cells using the MTT assay and fluorescent microscopy studies. © 2014 The Royal Society of Chemistry.
Simple colorimetric trypanothione reductase-based assay for high-throughput screening of drugs against leishmania intracellular amastigotes
(2014) Den Bogaart, Erika Van; Schoone, Gerard J.; England, Paul; Faber, Dorien; Orrling, Kristina M.; Dujardin, Jean-Claude; Sundar, Shyam; Schallig, Henk D.F.H.; Adams, Emily R.
Critical to the search for new anti-leishmanial drugs is the availability of high-throughput screening (HTS) methods to test chemical compounds against the relevant stage for pathogenesis, the intracellular amastigotes. Recent progress in automated microscopy and genetic recombination has produced powerful tools for drug discovery. Nevertheless, a simple and efficient test for measuring drug activity against Leishmania clinical isolates is lacking. Here we describe a quantitative colorimetric assay in which the activity of a Leishmania native enzyme is used to assess parasite viability. Enzymatic reduction of disulfide trypanothione, monitored by a microtiter plate reader, was used to quantify the growth of Leishmania parasites. An excellent correlation was found between the optical density at 412 nm and the number of parasites inoculated. Pharmacological validation of the assay was performed against the conventional alamarBlue method for promastigotes and standard microscopy for intracellular amastigotes. The activity of a selected-compound panel, including several anti-leishmanial reference drugs, demonstrated high consistency between the newly developed assay and the reference method and corroborated previously published data. Quality assessment with standard measures confirmed the robustness and reproducibility of the assay, which performed in compliance with HTS requirements. This simple and rapid assay provides a reliable, accurate method for screening anti-leishmanial agents, with high throughput. The basic equipment and manipulation required to perform the assay make it easy to implement, simplifying the method for scoring inhibitor assays. © 2014, American Society for Microbiology.
Comparison of the neuroprotective potential of Mucuna pruriens seed extract with estrogen in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced PD mice model
(2014) Yadav, Satyndra Kumar; Prakash, Jay; Chouhan, Shikha; Westfall, Susan; Verma, Mradul; Singh, Tryambak Deo; Singh, Surya Pratap
Parkinson's disease (PD) is one of the most common neurodegenerative disease found in the aging population. Currently, many studies are being conducted to find a suitable and effective cure for PD, with an emphasis on the use of herbal plants. In Ayurveda, Mucuna pruriens (Mp), a leguminous plant, is used as an anti-inflammatory drug. In this study, the neuroprotective effect of an ethanolic extract of Mp seed is evaluated in the 1-methyl-4-phenyl-1,2,3,6- tetrahydropyridine (MPTP) model of PD and compared to estrogen, a well reported neuroprotective agent used for treating PD. Twenty-four Swiss albino mice were randomly divided into four groups: Control, MPTP, MPTP + Mp and MPTP + estrogen. The behavioural recovery in both Mp and estrogen treated mice was investigated using the rotarod, foot printing and hanging tests. The recovery of dopamine neurons in the substantia nigra (SN) region was estimated by tyrosine hydroxylase (TH), immunostaining. Additionally inducible nitric oxide synthase (iNOS) and glial fibrillary acidic protein (GFAP) immunoreactivity was evaluated to assess the level of oxidative damage and glial activation respectively. The levels of dopamine and its metabolite in the nigrostriatal region were measured by HPLC. Mp treatment restored all the deficits induced by MPTP more effectively than estrogen. Mp treatment recovered the number of TH-positive cells in both the SN region and the striatum while reducing the expression of iNOS and GFAP in the SN. Treatment with Mp significantly increased the levels of dopamine, DOPAC and homovanillic acid compared to MPTP intoxicated mice. Notably, the effect of Mp was greater than that elicited by estrogen. Mp down regulates NO production, neuroinflammation and microglial activation and all of these actions contribute to Mp's neuroprotective activity. These results suggest that Mp can be an effective treatment for neurodegenerative diseases, especially PD by decreasing oxidative stress and possibly by implementing neuronal and glial cell crosstalk. © 2013 Elsevier B.V. All rights reserved.
Bayesian survival analysis of head and neck cancer data using lognormal model
(Taylor and Francis Inc., 2014) Makkar, Puja; Srivastava, Puneet K.; Singh, R.S.; Upadhyay, S.K.
The paper considers a lognormal model for the survival times and obtains a Bayes solution by means of Gibbs sampler algorithm when the priors for the parameters are vague. The formulation given in the paper is mainly focused for censored data problems though it is equally well applicable for complete data scenarios as well. For the purpose of numerical illustration, we considered two real data sets on head and neck cancer patients when they have been treated using either radiotherapy or chemotherapy followed by radiotherapy. The paper not only compares the survival functions for the two therapies assuming a lognormal model but also provides a model compatibility study based on predictive simulation results so that the choice of lognormal model can be justified for the two data sets. The ease of our analysis as compared to an earlier approach is certainly an advantage. © 2014 Copyright Taylor and Francis Group, LLC.
Seedling growth of five tropical dry forest tree species in relation to light and nitrogen gradients
(Oxford University Press, 2014) Tripathi, S.N.; Raghubanshi, A.S.
Aims Increasing anthropogenic nitrogen (N) deposition has been claimed to induce changes in species composition and community dynamics. A greenhouse experiment was conducted to examine the effect of increased N availability on growth and functional attributes of seedlings of five tree species with different life history characteristics under varying irradiances. The following questions have been addressed: (i) how do the pioneer and non-pioneer species respond in absolute growth and relative growth rate (RGR) to the interaction of light and nitrogen? (ii) how does the interaction between irradiance and nitrogen availability modulate growth attributes (i.e. functional attributes)? (iii) is there any variation in growth responses between leguminous and non-leguminous species along the light and nitrogen gradients? Methods: Seedlings of five tree species (Acacia catechu, Bridelia retusa, Dalbergia sissoo, Lagerstroemia parviflora and Terminalia arjuna) were subjected to twelve combinations of irradiance and N levels. Various growth traits, including height (HT), basal area (BA), whole plant dry biomass (MD), leaf mass per unit area (LMA), leaf area ratio (LAR), net assimilation rate (NAR), RGR, biomass fractions, root-to-shoot ratio (R:S) and leaf nitrogen content, were studied to analyse intra- and inter-specific responses to interacting light and N gradients. Important Findings: Significant interactions for irradiance and N availability for majority of growth attributes indicates that growth and biomass allocation of seedlings were more responsive to N availability under high irradiance. However, species responded differentially to N addition and they did not follow successional status. Slow growers (B. retusa, a shade-tolerant species and L. parviflora, a light demander) exhibited greater response to N enrichment than the fast growers (A. catechu, D. sissoo and T. arjuna). However, N-mediated increment in growth traits was greater in non-legumes (B. retusa, L. parviflora and T. arjuna) compared with that of legumes (A. catechu and D. sissoo). Allocation of biomass to root was strongly suppressed at the highest N supply across species; however, at high irradiance and high N availability, a greater suppression in R:S ratio was observed for B. retusa. NAR was a stronger determinant of RGR relative to LAR, suggesting its prominent role in increased RGR along increasing irradiances. Overall, a higher growth response of slow-growing species to elevated N levels, particularly the non-pioneers (B. retusa and L. parviflora) suggests that future N deposition may lead to perturbations in competition hierarchies and species composition, ultimately affecting community dynamics in nutrient-poor tropical dry forests. © The Author 2013.
Synthesis of mono- and bi-metallic dithiocarboxylate-alkyne complexes from sunlight driven insertion reaction and their antibacterial activity
(2014) Patel, Sumanta K.; Tirkey, Vijaylakshmi; Mishra, Sasmita; Dash, Hirak R.; Das, Surajit; Shukla, Madhulata; Saha, Satyen; Mobin, Shaikh M.; Chatterjee, Saurav
Sunlight driven synthesis, characterization and antibacterial evaluation of cyclopentadienyl based metal-dithiocarboxylate alkyne complexes, [LM(CO) n(η2-S2C)CCR], [{L = η5- C5H5, M = W, R = (η5-C5H 4)Fe(η5-C5H5), n = 2}; {L = η5-C5H5, M = W, R = -C(CH 3)CH2, n = 2}; {L = η5-C5H 5, M = Mo, R = -C(CH3)CH2, n = 2}; {L = η5-C5Me5, M = Fe, R = Ph, n = 1}] (5-8) have been carried out. Reactivity of metal-dithiocarboxylate alkyne complexes towards dicobaltoctacarbonyl were studied to obtain a trimetallic dithiocarboxylate complex (9-11). Structural characterizations of 7 and 8 have been carried out crystallographically and DFT calculation was performed on compound 8 to understand the electronic properties of the complex. © 2013 Elsevier B.V. All rights reserved.
Temperature dependent action of growth hormone on somatic growth and testicular activities of the catfish, Clarias batrachus
(Academic Press Inc., 2014) Gopal, Raj Naresh; Kumar, Pankaj; Lal, Bechan
Effects of growth hormone on somatic growth and testicular activities were studied during late quiescence and early recrudescence phases of the reproductive cycle of the catfish, Clarias batrachus. The administration of exogenous growth hormone (GH) during the late quiescence phase (December-January; ambient water temperature-15.2. ±. 1. °C) did not influence the somatic growth as well as the testicular activity, as no change in body weight, testis weight, plasma level of insulin-like growth factor I (IGF-I) and testicular morphology was detected following GH treatment, though the plasma testosterone was marginally increased. While during the early recrudescence phase (March-April; ambient water temperature-28.1. ±. 2. °C), GH treatment promoted the production of insulin like growth factor-I and testicular steroidogenic activity in a dose dependent manner, as was evident from the significant increase in the circulating levels of testosterone and estradiol-17β. GH treatment also increased body weight, testicular weight and gonadosomatic index, suggesting its involvement in testicular development. The GH treatment promoted spermatogonial proliferation and accelerated the spermatogenic process in the present catfish. These results, thus, suggest that GH influences the somatic growth and testicular activities depending on the temperature of the rearing water; warmer temperature and longer photoperiod promote testicular steroidogenic and spermatogenic activities in fish. This study has immense practical use in fisheries science. © 2013 Elsevier Inc.
Structural characterization of as-deposited cesium iodide films studied by X-ray diffraction and transmission electron microscopy techniques
(2014) Triloki; Garg, P.; Rai, R.; Singh, B.K.
In the present work, cesium iodide (CsI) thin films of different thicknesses have been prepared by thermal evaporation technique. The crystallite size and grain size of these films are compared by using X-ray diffraction (XRD) profile analysis as well as by transmission electron microscopy (TEM) counting, respectively. These two methods provide less deviation between crystallite size and grain size in the case of thin CsI films of 4 nm, but there is comparatively large difference in case of thicker CsI films (20 nm, 100 nm and 500 nm). It indicates that dislocations are arranged in a configuration which causes small orientational difference between two adjacent coherent regions. The crystallite size obtained from XRD corresponds to the size of the coherent scattering region, whereas in TEM micrograph, single grain may correspond to many such coherent scattering regions. Other physical parameters such as strain, stress and deformation energy density are also estimated precisely for the prominent XRD peaks of thicker CsI films in the range 2θ=20 -80 by using a modified Williamson-Hall (W-H) analysis assuming uniform deformation model (UDM), uniform deformation stress model (UDSM) and uniform deformation energy density model (UDEDM). © 2013 Elsevier B.V. All rights reserved.
Mapping the research productivity of Banaras Hindu University: A scientometric study
(Asian Research Publishing Network (ARPN), 2014) Balasubramani, R.; Parameswaran, R.
The study presents the growth and the contribution of research carried out by the scientists of Banaras Hindu University (BHU). The pattern of communications of authors and scattering of their research output in different journals, analysis the strong and weak areas of university research. The data for the study was taken from the Web of Science online database published by Institute for Scientific information (ISI). The study shows that there was a gradual growth of publications during 2000 - 2011. The annual average research output of BHU was 578 records and the research output of the scientists is fairly collaborative. "Current Science" is one of the most preferred journals of the authors of BHU. The Institute of Technology leads in publications productivity with 1482 (21.3%) articles. The authors of BHU have been collaborated with the foreign authors for their research work. © 2005 - 2014 JATIT & LLS. All rights reserved.
Relic excavated in western India is probably of Georgian Queen Ketevan
(Elsevier B.V., 2014) Rai, Niraj; Taher, Nizamuddin; Singh, Manvendra; Chaubey, Gyaneshwer; Jha, Aditya Nath; Singh, Lalji; Thangaraj, Kumarasamy
History has well documented the execution of Queen Ketevan of Georgia by the Persian Emperor of modern day Iran. Based on historical records, in 1624 two Augustinian friars unearthed the queen's remains and one of them brought the relic to the St. Augustine convent in Goa, India. We carried out ancient DNA analysis on the human bone remains excavated from the St. Augustine convent by sequencing and genotyping of the mitochondrial DNA. The investigations of the remains revealed a unique mtDNA haplogroup U1b, which is absent in India, but present in Georgia and surrounding regions. Since our genetic analysis corroborates archaeological and literary evidence, it is likely that the excavated bone belongs to Queen Ketevan of Georgia. © 2013 Elsevier B.V. and Mitochondria Research Society. All rights reserved.
Role of gamma radiation in changing phytotoxic effect of elevated level of ozone in Trifolium alexandrinum L. (Clover)
(Dokuz Eylul University, 2014) Chaudhary, Nivedita; Agrawal, Shashi Bhushan
The present study was conducted on clover (Trifolium alexandrinum L. cv Wardan), to investigate the effect of ambient and elevated (ambient +10 ppb O3) ozone (O3) on plants grown in open top chambers (OTCs) germinated from gamma (γ) irradiated seeds. Dry seeds were subjected to irradiation with 0, 5, 10 and 20 krad doses of γ rays from 60Co source. Dose dependent differential responses were observed on growth and biomass, photosynthetic pigments, metabolites, antioxidative defense system of plant. Growth parameters and biomass of plants were severely affected under elevated O3 with increasing radiation doses, except, 5 krad which showed a reverse trend of response. Photosynthetic pigments and total soluble proteins were also reduced with higher dose of γ radiation and elevated O3. Reactive oxygen species formation and membrane damage increased significantly to different extents. Plants grown from seeds irradiated with low dose (5 krad) of γ irradiation depicted more induction of antioxidants (enzymatic and non- enzymatic) than higher doses suggesting their high ameliorative capability against elevated O3. Principal component analysis has also confirmed that plants grown from 5 krad γ irradiated seeds performed better against O3 depicting reduction in negative effect against elevated O3. The experimental findings evidently showed that 5 krad γ radiations altered the O3 induced stress and thus minimized the loss in biomass of the test plant. © Author(s) 2014.
Removal of barium ions from aqueous solutions by barium titanate using radiotracer technique:
(2014) Mishra, S.P.; Srinivasu, N.
The adsorption of barium ions on barium titanate in an aqueous solution was studied by means of batch technique as a function of Ba(II) concentration, temperature and solution pH using Ba-140 as radiotracer. The results show that adsorption is essentially complete in ca 180min and the steady state values of adsorption at various concentrations agree well with the classical Freundlich isotherm and follow first order kinetics. The pH and temperature of the solution markedly affect the extent of adsorption. Exposure of the activated barium titanate adsorbent to neutrons and γ irradiation from a (Ra-Be) neutrons source having an integral flux of 3.85x106 neutrons/cm2 sec and associated with a nominal γ does of Ca 172 rads/h, affects its adsorption capacity markedly.
Experimental and theoretical studies of vibrational spectrum and molecular structure and related properties of pyridoxine (vitamin B6)
(Elsevier, 2014) Srivastava, Mayuri; Rani, P.; Singh, N.P.; Yadav, R.A.
Vibrational spectrum of pyridoxine has been investigated using experimental IR and Raman spectroscopic and density functional theory (DFT) methods. Vibrational assignments of the observed IR and Raman bands have been proposed in light of the results obtained from computations. In order to assign the observed IR and Raman frequencies the potential energy distributions (PEDs) have also been computed. Optimized geometrical parameters suggest that if the OH groups of the two methyl groups are replaced by H atoms the resulting molecule has Cs point group symmetry. To investigate molecular stability and bond strength we have used natural bond orbital analysis (NBO). Charge transfer occurs in the molecule have been shown by the calculated highest occupied molecular orbital-lowest unoccupied molecular orbital (HOMO-LUMO) energies. The mapping of electron density iso-surface with electrostatic potential (ESP), has been carried out to get the information about the size, shape, charge density distribution and site of chemical reactivity of the molecule. © 2013 Elsevier Ltd. All rights reserved.
Enhanced luminescence and energy transfer study in Tb:Sm codoped lead fluorotellurite glass
(2014) Bahadur, A.; Dwivedi, Y.; Rai, S.B.
Spectroscopic properties of Sm3+, Tb3+ doped and Tb3+:Sm3+ co-doped lead fluorotellurite glasses have been studied in detail. On the excitation with 355 and 532 nm laser wavelengths, the luminescence properties of the singly and doubly doped glasses have been analyzed. Intensity of characteristic emission bands due to Sm3+ ions is appreciably enhanced in the presence of Tb3+ ions. This is due to the energy transfer from Tb3+ to Sm3+ ions. Different energy transfer parameters have also been calculated, which affirm an efficient energy transfer from Tb3+ to Sm3+ ions. © 2013 Elsevier B.V. All rights reserved.

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