Browsing by Issue Date, starting with "2009"

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Study of ionic conductivity, dielectric characteristics and capacitance measurement of -irradiated conducting polymeric electrolytes
(2009) G.K. Prajapati; P.N. Gupta
High conductivity and high specific capacitance of certain kinds of ion-conducting solid polymer electrolytes has been the subject of intensive study in recent years. These materials play an important role in understanding the polymer characteristics and its technological applications with tremendous impact on several aspects of our life. Extensive studies have been undertaken to investigate ion transport behavior and the effect of γ-irradiation on polymer materials. In this communication, an attempt has been made to study the electrical and dielectric properties including capacitance measurement for pure PVA and PVA-H3PO4 complexed electrolytes under γ-radiation. Various parameters such as conductivity, dielectric constant, dielectric loss, loss tangent and apacitance values have been determined using complex impedance method over the temperature range 303-383 K and frequency domain 10 kHz-1 MHz for different molar ratios of complexed materials. Particular attention and emphasis have been given to the conducting polymers in the capacitance performance of the polymeric system.
Fabrication of white organic light-emitting diodes by co-doping of emissive layer
(2009) Ritu Srivastava; Gayatri Chauhan; Kanchan Saxena; S.S. Bawa; P.C. Srivastava; M.N. Kamalasanan
Efficient white light emission by mixing of red emission from (Ir-BTPA) [bis(2-(2′-benzothienyl) pyridinato-N,C3) (acetyl-acetonate) iridium(III) and greenish blue from (FIrPic) [bis(2-(4,6-difluorophenyl) pyridinato-N,C2) iridium(III)] has been studied. Ir-BTPA and FIrPic are co-doped into a 4, 4′ bis 9 carbozyl (biphenyl) (CPB) host. The device emission colour is controlled by varying dopant concentration. Photoluminescence (PL), electroluminescence (EL) and colour coordinates have been studied as a function of applied voltage. The EL spectra of the devices with the co-doped emissive layer show three emission peaks at 469, 500 and 611 nm. Commission Internationale de l'Eclairage (CIE) coordinates of the devices are 0.27, 0.32 at 18 V and are well within the white region.
Synthesis, electronic and IR spectral studies of some polymeric cobalt(II), nickel(II), zinc(II) and cadmium(II) azido complexes with hydrazine
(2009) Vinod P. Singh; K.B. Singh; K.K. Narang
A series of polymeric cobalt(II), nickel(II), zinc(II) and cadmium(II) azido complexes with hydrazine of the type [M(N2H4)(H 2O)(N3)Cl]n, [M(N2H 4)(N3)2]n and [M(N2H 4)2(N3)2]n have been prepared. These were characterized by elemental analyses, magnetic susceptibility measurements, electronic and IR spectra. The complexes are highly insoluble in polar and non polar solvents. All the complexes decompose with explosion at different temperatures between 100°C to 200°C. The magnetic moment and electronic spectral data for Co(II) and Ni(II) complexes suggest that the complexes have octahedral structure. The ligand-field parameters (10 Dq, B, Β, Β° and LFSE) have also been calculated for all Co(II) and Ni(II) complexes which indicate a significant covalent character of M-L bonds. The IR spectra of the complexes show that the azide group and hydrazine molecule both act as bidentate bridging ligands in [M(N2H 4)(H2O)(N3)Cl]n and [M(N 2H4)(N3)2]n type complexes but the azide group is terminally bonded to metal in all [M(N 2H4)2(N3)2]n type complexes.
Surveillance of corporate governance compliance through a prolific advance
(SAGE Publications Ltd, 2009) Twinkle Prusty
Globalization has not only significantly heightened business risks, but has also compelled Indian companies to adopt international norms and good governance. Much has been heard, talked and said about the topic of corporate governance, but unfortunately the parameters to judge its practical implementation is still not very clear to many. It is the premise of apprehension for Indian corporates to initiate hard core action so as to evolve and devour corporate governance at a rapid speed for their survival and growth. Corporate governance is an enduring process that requires integrated efforts and in today's exceedingly specialized epoch, it is indispensable to be the specialist to achieve quality. The question arises that whether the compliance of good corporate governance has evolved and espoused with the changing circumstances of the corporate life and customized to meet those circumstances. This whole exercise calls for professional capability, deliberation, commitment of time and focused awareness with unprejudiced approach. Thus, the surfacing of a growing consensus in regard to the compliance of good corporate governance practices imbibed through appropriate reporting in Indian industries, has been studied to explore the vital dimensions of corporate governance standards for getting pledged to the ideology with the underlying effective analysis, that sets to be a way of life and not mere compliance with a set of rules. This paper presents the evaluation of the compliance of corporate governance on the basis of assigning governance scores to the sample companies as per clause 49 of the listing agreement of SEBI Act. © 2009, SAGE Publications Ltd. All rights reserved.
Colonic conduit for esophageal bypass in Celphos-induced tracheoesophageal fistula: Our experience of two cases
(2009) Vivek Srivastava; Mumtaz Ansari; Somprakas Basu; Damayanti Agrawal; T.K. Lahiri; Anand Kumar
[No abstract available]
Process parameter optimization for textural properties of ready-to-eat extruded snack food from millet and legume pieces blends
(2009) Subir Kumar Chakraborty; Daya S. Singh; B.K. Kumbhar; Dheer Singh
Five blends of millets and legume pieces (viz. 12, 16, 20, 24, 28% legume pieces) at varying moisture contents (12, 15, 18, 21, 24%, wet basis [w.b.]) were subjected to extrusion cooking in a single-screw laboratory extruder Brabender DA47055. The extruder was operated at different die head temperatures (160-200C), barrel temperatures (100-140C) and screw speeds (100-140 rpm). Designed experiments were conducted based on central composite rotatable design to determine the optimum processing condition for extruded products. The processing parameters were optimized with the help of response surface methodology to obtain product with maximum crispness and with minimum hardness and cutting strength. The optimum processing conditions obtained were moisture content 24%, w.b.; blend ratio 18.7% legume pieces; die head temperature 171.2C; barrel temperature 140C; and screw speed 103.8 rpm. The corresponding textural properties of the extrudates in terms of crispness, hardness and cutting strength were 50, 48.2 N and 79.7 N, respectively. © 2009, Wiley Periodicals, Inc.
Recombinant YopJ induces apoptosis in murine peritoneal macrophages in vitro : Involvement of mitochondrial death pathway
(2009) Ashok Kumar Pandey; Ajit Sodhi
Yersinia species during infection adhere to host immune cells primarily to macrophages and employ its secretary proteins known as Yersinia outer proteins to trigger death in infected cells. In the present study, it is shown that recombinant Yersinia outer protein J (rYopJ) could induce apoptosis in murine peritoneal macrophages in vitro as assessed by morphological features, internucleosomal DNA fragmentation, change in mitochondrial membrane potential (MMP) (Δψm), activation of caspases and Annexin V binding. rYopJ-induced cell death was dose and time dependent. Pre-treatment with broad-spectrum caspase inhibitor Z-VAD-FMK, caspase-3 inhibitor Ac-DEVD-CHO and caspase-8 inhibitor Z-IETD-FMK prevented the change in MMP and DNA fragmentation, suggesting caspase-dependent apoptosis of rYopJ-treated macrophages. Blocking the endocytosis by pre-treatment of cells with cytochalasin B did not prevent the rYopJ-induced macrophages apoptosis. The data further suggest that rYopJ-induced apoptosis is mediated by molecules upstream of caspase-8 and relay through mitochondrial pathway involving Bax, Bcl-2, activation of caspase-8 and caspase-3, Bid and polyadenosine diphosphate-ribose polymerase cleavage, cytochrome c release and DNA fragmentation. The Japanese Society for Immunology. © 2009. All rights reserved.
A β-galactosidase from pea seeds (PsBGAL): purification, stabilization, catalytic energetics, conformational heterogeneity, and its significance
(2009) Alka Dwevedi; Arvind M. Kayastha
A basic glycosylated β-galactosidase (PsBGAL) has been purified from pea seeds by 910-fold with a specific activity of 77.33 μmol min-1 mg-1 protein. The purified enzyme is an electrophoretically homogeneous protein consisting of a single protein band with an apparent Mr of 55 kDa, while the deglycosylated enzyme has a Mr of 54.2 kDa on SDS-PAGE under reducing conditions. According to MALDI-TOF measurements of the 55 kDa band, the enzyme showed a homology with BGAL from other sources present in the SWISS-PROT database, while it showed no resemblance to any lectin. The N-terminal sequence of PsBGAL was determined as TIECK and showed a resemblance to BGAL from Arabidopsis thaliana (Q93Z24). The enzyme showed an unique property of multiple banding patterns on SDS-PAGE at 20 mA current, with tryptic digests of all bands having similar m/z values (using MALDI-TOF) while it showed only a single band at 10 mA current. PsBGAL is effectively compartmentalized during seed maturation inside vacuoles (pH ∼ 5). The enzyme is capable of hydrolyzing pea seed xyloglucan, and it may be involved in modifying the cell wall architecture during seedling growth and development. The enzyme has a protonated carboxyl group at its active site as observed by ionization constant, thermodynamics, and chemical modification studies. © 2009 American Chemical Society.
Enrichment of sugar content in melon fruits by hydrogen peroxide treatment
(2009) Keiko Ozaki; Akio Uchida; Tomoko Takabe; Fumi Shinagawa; Yoshito Tanaka; Teruhiro Takabe; Takahisa Hayashi; Tasuku Hattori; Ashwani K. Rai; Tetsuko Takabe
Since sweetness is one of the most important qualities of many fruits, and since sugars are translocated from leaves to fruits, the present study investigates photosynthetic activity, activity of sugar metabolizing enzymes, sugar content in leaves and fruits and endogenous levels of hydrogen peroxide in leaves of melon plants treated with various dilutions of hydrogen peroxide, a nonspecific signaling molecule in abiotic stress. For this purpose, 4-month-old melon plants were treated with various concentrations (<50 mM) of hydrogen peroxide by applying 300 mL per day to the soil of potted plants. The treatments resulted in increased fructose, glucose, sucrose and starch in the leaves and fruits. The most effective concentration of hydrogen peroxide was 20 mM. During the day, soluble sugars in leaves were highest at 12:00 h and starch at 15:00 h. Furthermore, the peroxide treatment increased the photosynthetic activity and the activities of chloroplastic and cytosolic fructose-1,6-bisphosphatase, sucrose phosphate synthase and invertases. Thus, our data show that exogenous hydrogen peroxide, applied to the soil, can increase the soluble sugar content of melon fruits. © 2008 Elsevier GmbH. All rights reserved.
Response of melatonin receptor mt1 in spleen of a tropical indian rodent, funambulus pennanti, to natural solar insolation and different photoperiodic conditions
(2009) Sanjukta Lahiri; Chandana Haldar
We analyzed the effect of natural solar insolation and artificial photoperiodic conditions on melatonin MT1 receptor expression of a tropical rodent, Funambulus pennanti. Melatonin mediates reproductive and circadian responses and regulates the production of a large number of cytokines, including interleukin-2 (IL-2), via modulation of MT1 receptor expression. Maximum pineal activity, resulting in high melatonin level, low melatonin receptor expression, and increased splenic mass, was noted in the winter months, while an opposite effect was noted during the summer months. Further, constant light exposure mimicked an "enhanced summer"-like condition with significant hyposplenia, and an opposite effect was observed with constant dark exposure with significant splenomegaly in F. pennanti. In the annual study, a slight increase in melatonin level was noted during the monsoon period, when the duration of photoperiod was the same but the amount of solar insolation and direct radiation decreased. The present study found that not only the duration of natural sunlight (i.e., photoperiod) but the intensity of sunlight expressed by solar insolation affects the circulatory level of melatonin and melatonin receptor expression in this wild tropical rodent. An increase in the circulatory level of melatonin induced a decrease in its receptor subtype MT1 expression in splenic cells, both at the transcriptional and translational levels, thus reflecting autoregulatory down-regulation of melatonin receptors. Therefore, in our animal model, F. pennanti melatonin may be suggested as a molecular messenger of photoperiodic signals (duration and intensity) directly acting via MT1 receptor regulation to adapt the immune system of animals residing in the tropical zone. © 2009 Informa Healthcare USA, Inc.
Nickel-induced oxidative stress and the role of antioxidant defence in rice seedlings
(2009) Ruchi Maheshwari; R.S. Dubey
Seedlings of rice (Oryza sativa L.) cv. Pant-12 grown in sand cultures containing 200 and 400 μM NiSO4, showed a decrease in length and fresh weight of roots and shoots. Nickel was readily taken up by rice seedlings and the concentration was higher in roots than shoots. Nickel-treated seedlings showed increased rates of superoxide anion (O2•-) production, elevated levels of H2O2 and thiobarbituric acid reactive substances (TBARS) demonstrating enhanced lipid peroxidation, and a decline in protein thiol levels indicative of increased protein oxidation compared to controls. With progressively higher Ni concentrations, non-protein thiol and ascorbate (AsA) increased, whereas the level of low-molecular-weight thiols (such as glutathione and hydroxyl-methyl glutathione), the ratio of these thiols to their corresponding disulphides, and the ratio of AsA to dehydroascorbic acid declined in the seedlings. Among the antioxidant enzymes studied, the activities of all isoforms of superoxide dismutase (Cu-Zn SOD, Mn SOD and Fe SOD), guaiacol peroxidases (GPX) and ascorbate peroxidase (APX) increased in Ni-treated seedlings, while no clear alteration in catalase activity was evident. Activity of the ascorbate-glutathione cycle enzymes monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR) and glutathione reductase (GR)-significantly increased in Ni-treated seedlings. However such increase was apparently insufficient to maintain the intracellular redox balance. Results suggest that Ni induces oxidative stress in rice plants, resulting in enhanced lipid peroxidation and decline in protein thiol levels, and that (hydroxyl-methyl) glutathione and AsA in conjunction with Cu-Zn SOD, GPX and APX are involved in stress response. © Springer Science+Business Media B.V. 2009.
Biodegradation of trichloroethylene (TCE) by methanotrophic community
(2009) Awadhesh K. Shukla; Pranjali Vishwakarma; S.N. Upadhyay; Anil K Tripathi; H.C. Prasana; Suresh K. Dubey
Laboratory incubation experiments were carried out to assess the potential of methanotrophic culture for degrading TCE. Measurements of the growth rate and TCE degradation showed that the methanotrophs not only grew in presence of TCE but also degraded TCE. The rate of TCE degradation was found to be 0.19 ppm h-1. The reverse transcriptase-PCR test was conducted to quantify expression of pmoA and mmoX genes. RT-PCR revealed expression of pmoA gene only. This observation provides evidence that the pmoA gene was functionally active for pMMO enzyme during the study. The diversity of the methanotrophs involved in TCE degradation was assessed by PCR amplification, cloning, restriction fragment length polymorphism and phylogenetic analysis of pmoA genes. Results suggested the occurrence of nine different phylotypes belonging to Type II methanotrophs in the enriched cultures. Out of the nine, five clustered with, genera Methylocystis and rest got clustered in to a separate group. © 2008 Elsevier Ltd. All rights reserved.
Fluorescence quenching of 9-cyanoanthracene in presence of zinc tetraphenylporphyrin in a polar liquid medium
(2009) Paulami Mandal; Sanat Kumar Tiwari; Tapan Ganguly; Subrata Sinha
Steady-state and time-resolved techniques are used to study photoinduced electron and/or excitational energy transfer processes involved within a novel donor (zinc tetraphenylporphyrin)-acceptor (9-cyanoanthracene) system in a polar liquid medium (acetonitrile) at the ambient temperature (300 K). After photoexcitation of 9-cyanoanthracene, its fluorescence emission as well as lifetime are found to be quenched in presence of zinc tetraphenylporphyrin. The fluorescence quenching is ascribed to be due to the combined effect of electron transfer from zinc tetraphenylporphyrin to 9-cyanoanthracene and energy transfer (radiative as well as non-radiative) from 9-cyanoanthracene to zinc tetraphenylporphyrin. The highly exergonic values of Gibbs free energy change for both forward electron transfer reaction (-1.15 eV) and charge recombination reaction (-1.94 eV) indicate the possibilities of occurrences of these two processes in the Marcus inverted region. The fluorescence quenching rate due to photoinduced electron transfer reaction is found to be close to the diffusion-controlled limit within the present donor-acceptor system upon excitation of the acceptor molecules. © 2009 Elsevier B.V. All rights reserved.
Synthesis and characterization of ultra fine barium calcium titanate, barium strontium titanate and Ba1-2xCaxSrxTiO3 (x = 0.05, 0.10)
(2009) Alok Kumar Rai; K.N. Rao; L. Vinoth Kumar; K.D. Mandal
Many desirable features can be brought in when certain ferroelectric materials are doped with calculated amount of foreign atoms. Ba1-2xCaxSrxTiO3 (BCST), Ba0.8Ca0.2TiO3 (BCT) and Ba0.8Sr0.2TiO3 (BST) have been synthesized via Pechini precursor route. It has been found that single phase was formed at 820-860 °C, which was confirmed by the XRD analysis. FTIR studies confirmed the presence of functional groups such as O-H, carboxylate ester and the carbonate in dry samples. Crystallite sizes of these ceramics were calculated by X-ray line broadening analysis, which were also confirmed by SEM studies. EDX studies confirmed the high purity of the synthesized materials. © 2008 Elsevier B.V. All rights reserved.
Comparative response of seedlings of selected native dry tropical and alien invasive species to CO2 enrichment
(2009) Purnima Raizada; Anamika Singh; A.S. Raghubanshi
Aims Global climate change and ongoing plant invasion are the two prominent ecological issues threatening biodiversity world wide. Among invasive species, Lantana camara and Hyptis suaveolens are the two most important invaders in the dry deciduous forest in India. We monitored the growth of these two invasive species and seedlings of four native dry deciduous species (Acacia catechu, Bauhinia variegata, Dalbergia latifolia and Tectona grandis) under ambient (375-395 μ mol mol-1) and elevated CO2 (700-750 μ mol mol-1) to study the differential growth response of invasive and native seedlings. Methods Seedlings of all the species were exposed to ambient and elevated CO2. After 60 days of exposure, seedlings were harvested and all the growth-related parameters like plant height; biomass of root, stem and leaves; total seedling biomass; R/S ratio; allocation parameters; net assimilation rate (NAR) and relative growth rate (RGR) were determined. Important Findings Biomass, RGR and NAR of all the species increased under elevated CO2 but the increase was higher in invasive species and they formed larger seedlings than natives. Therefore under the CO 2-enriched future atmosphere, competitive hierarchies could change and may interfere with the species composition of the invaded area.
Osteogenic activity of constituents from Butea monosperma
(2009) Rakesh Maurya; Dinesh K. Yadav; Geetu Singh; Biju Bhargavan; P.S. Narayana Murthy; Mahendra Sahai; Man Mohan Singh
Phytochemical investigation from the stem bark of Butea monosperma, led to the isolation and identification of three new compounds named buteaspermin A (1), buteaspermin B (2) and buteaspermanol (3), along with 19 known compounds. The structure of compounds 1-22 were established on the basis of their spectroscopic data. The isolated compounds 2-17 were evaluated using neonatal (1-3 day old) rat calvaria derived primary osteoblast cultures. Five of these compounds 7, 10-13 showed promising osteogenic activity, attributed to increased osteoblast proliferation, differentiation and mineralization as evidenced by marked increase in expression of alkaline phosphatase, an early phase differentiation marker, and alizarin Red S staining of osteoblasts cultured for 48 h and von Kossa silver staining of nodules formed 15 days after culture with these compounds. Quantification of mineralization by optical density measurement of Alizarin Red S extracted from stained osteoblasts cultured for 7 days in presence of these compounds showed significant (P < 0.05, vs corresponding vehicle control group) increase in mineralization. On the basis of biological results, structure-activity relationships are discussed. © 2009 Elsevier Ltd. All rights reserved.
Evaluation of changes in oil cells and composition of essential oil in lemongrass (Cymbopogon citratus (D.C.) Stapf.) due to supplemental ultraviolet-B irradiation
(2009) Rima Kumari; S.B. Agrawal; Abhijit Sarkar
Field grown lemongrass (Cymbopogon citratus (D.C.) Stapf.) was exposed for a short duration (3 h/day) to supplemental ultraviolet-B (sUV-B) to evaluate its effect on oil cells and chemical composition of essential oils. Histochemical studies showed an increase in number of oil cells in tissues under sUV-B treatment. Estimation of essential oil content also demonstrated an increase of 25.7% in sUV-B treated plants over its control. Gas chromatography-mass spectrometric (GC/MS) analysis of essential oils demonstrated significant variations in qualitative and quantitative expression of oil constituents of sUV-B exposed plants. sUV-B irradiation induced the formation of major compound z-citral within the investigated oil samples by 117.56% as compared to oil obtained from nonirradiated plants. Geraniol formate, pulegol, linalyl formate and other compounds also showed significant variations after sUV-B treatment. Results suggest that sUV-B exposure stimulated the production of oil cells vis-à-vis positive change in quality and percentage of essential oil contents of lemongrass. The results suggest some future prospects for better economical utilization of lemongrass after irradiation with low doses of sUV-B for its commercial exploitation.
Effect of surgical traumas on microcirculation
(2009) Visweswar Bhattacharya; Biswajit Mishra; Binayak Mishra; Umesh Kumar; Siddhartha Bhattacharya
Background: Adequate microcirculation in different tissues maintains the physiological function and heals surgical wounds. In any surgical procedure, the commonly used instruments are cautery, tissue forceps, and clamps. The fact that their inappropriate use produces an adverse effect on microcirculation is often not realized. By this study, we could demonstrate live, the effect of these surgical traumas. Methods: The study was conducted on the inferiorly based fasciocutaneous flap with a fascial extension in patients with a distal leg defect. The extended fascial flap was mounted on a glass slide and observed for live microcirculation under x160 magnification. Three methods were used: (a) cautery in low power, (b) microcrushing forceps to crush the vessels, and (c) noncrushing clamps at the base of the fascial flap. Results: It was observed that the vessels are well protected within the deep fascia. Once the fascia was pierced the current damaged the vessel wall. As the wattage was increased, it caused charring of the tissue and multiple vessels ultimately leading to cessation of blood flow. Once the vessel wall was crushed by forceps, blood extravasated in a variable intensity depending upon the size of the vessel. Clamping led to gradual slowing of blood flow with microclot formation. In certain vessels, there was discontinuity in the blood column and ultimately the blood flow stopped. Conclusion: This study showed live demonstration of the effect of surgical traumas on microcirculation. It should guide the surgeons to select the use of appropriate instruments which will cause minimal damage to vascularity and thereby lead to a better surgical outcome.
Pharmaceutical stability aspects of nanomedicines
(2009) Madaswamy S. Muthu; Si-Shen Feng
[No abstract available]
Cervical epidural anaesthesia for thyroid surgery
(Kathmandu University, 2009) Rahul Khanna; D.K. Singh
Background: Cervical epidural anaesthesia is a regional anaesthesia technique which has been used for upper limb surgery, upper thoracic wall surgery, carotid artery surgery and neck dissections. Anaesthesia for thyroid surgery can be complicated due to the altered functional status of the thyroid or its large size. Objective: This prospective study was designed to assess the effectiveness and safety of cervical epidural anaesthesia for thyroid surgery. Materials and methods: Cervical epidural anaesthesia was attempted in 9 patients and the results compared with 44 patients who underwent thyroid surgery under conventional general anaesthesia with endotracheal intubation. The epidural catheter was placed in the C7-T1 vertebral interspace and 10-15 ml of 1% Lignocaine with adrenaline was injected. Results: The technique of cervical epidural anaesthesia was successfully used in 8 out of 9 patients in whom it was attempted All patients were maintained in a state of conscious-sedation and effective analgesia was obtained in all 8 patients. There were no significant complications especially those related to diaphragmatic function and cardiovascular stability. In contrast patients undergoing surgery under conventional general anaesthesia had complications related to endotracheal intubation, cardiac arrhythmias and hypotension Conclusion: The technique of cervical epidural anaesthesia should be considered in thyroid patients where difficult endotracheal intubation is anticipated and in those in whom alterations in thyroid functional state make them vulnerable to cardiovascular complications under conventional general anaesthesia.