293 research outputs found

    Kinetics and mechanism of oxidation of erythro-series pentoses and hexoses by N-chloro-p-toluenesulfonamide

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    The kinetics and mechanism of oxidation of D-glucose, D-mannose, D-fructose, D-arabinose, and D-ribose with chloramine-T in alkaline medium were studied. The rate law, rate = k Chloramine-T] Sugar] HO-](2), was observed. The rate of the reaction was influenced by a change in ionic strength of the medium, and the dielectric effect was found to be negative. The latter enabled the computation of d(AB), the size of the activated complex. The reaction rate was almost doubled in deuterium oxide. Activation energies were calculated from the Arrhenius plots. HPLC and GLC-MS analyses of the products indicated that the sugars were oxidized to a mixture of aldonic acids, consisting of arabinonic, ribonic, erythronic, and glyceric acids. Based on these data, a plausible mechanism involving the aldo-enolic anions of pentoses and keto-enolic anions of hexoses is suggested. (C) 1998 Elsevier Science Ltd. All rights reserved

    The prognostic significance of Cdc6 and Cdt1 in breast cancer

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    DNA replication is a critical step in cell proliferation. Overexpression of MCM2-7 genes correlated with poor prognosis in breast cancer patients. However, the roles of Cdc6 and Cdt1, which work with MCMs to regulate DNA replication, in breast cancers are largely unknown. In the present study, we have shown that the expression levels of Cdc6 and Cdt1 were both significantly correlated with an increasing number of MCM2-7 genes overexpression. Both Cdc6 and Cdt1, when expressed in a high level, alone or in combination, were significantly associated with poorer survival in the breast cancer patient cohort (n = 1441). In line with this finding, the expression of Cdc6 and Cdt1 was upregulated in breast cancer cells compared to normal breast epithelial cells. Expression of Cdc6 and Cdt1 was significantly higher in ER negative breast cancer, and was suppressed when ER signalling was inhibited either by tamoxifen in vitro or letrozole in human subjects. Importantly, breast cancer patients who responded to letrozole expressed significantly lower Cdc6 than those patients who did not respond. Our results suggest that Cdc6 is a potential prognostic marker and therapeutic target in breast cancer patients.</p

    Kinetics of Oxidation of Cinnamyl Alcohol with Chloramine- T in Hydrochloric Acid Medium

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    Simulation of Electrode-Tissue Interface with Biphasic Pulse Train for Epiretinal Prosthesis

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    Abstract: Retinitis Pigmentosa (RP) and Agerelated Macular Degeneration (AMD) are diseases causing blindness in a large number of people. In this type of degenerative disease, mostly the photoreceptors are damaged, and thus attempts have been made to electrically stimulate the surviving inner retinal neurons and retinal ganglion cells (RGC) in order to restore vision. In this paper, the electrode-tissue interface is modeled to study the effect of electrode size and distance between the electrode and retina by applying biphasic pulse trains similar to in-vitro experiments and in-vivo trials. Simulations were carried out using the AC/DC module of COMSOL v4.3a with planer electrodes placed over the constitutive layers of retina. Biphasic pulses with varying pulse width, inter pulse interval and amplitude were applied to the stimulating electrode. The model is solved for time and frequency domain. Electric potential in the RGC layer was found to vary both as a function of electrode diameter and distance of the electrode

    Effect of organic and nano trace minerals at reduced levels in layer diets on egg quality characteristics and its trace mineral content

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    An experiment was conducted to assess the effect of organic and nano trace minerals (copper, zinc, manganese and iron) at reduced levels in layer diets on various egg quality characteristics and its trace mineral content. 240 Hy- Line W80 layer birds of 29 weeks old were randomly distributed to five treatment groups with four replicates having twelve birds each. Basal diet was supplemented with inorganic trace minerals to meet 100 per cent requirement to form control diet or with organic trace minerals at 75 and 50% of requirement or with nano trace minerals at 50 and 25% of requirement to form four test diets. Each diet was offered to four replicate groups for 84 days which was conveniently divided into three phases of 28 days each. Egg quality parameters, viz. egg weight, egg shape index, albumen index, yolk index, yolk color score, Haugh unit score, egg shell weight, albumen weight and yolk weight among the treatment groups were not affected by source and level of trace minerals. However, egg shell thickness was significantly higher in 25% nano trace mineral group on 28th day. The trace minerals (Zn and Fe) in the yolk were significantly lower at reduced trace mineral levels (50% organic or nano and 25% nano form) when compared to 100% (inorganic) and 75% levels (organic form). It was concluded that the substitution of inorganic trace minerals with organic or nano trace minerals at reduced levels (50 or 25%, respectively) in layer diets does not affect the egg quality parameters, but reduces Zn and Fe content in egg yolk

    For reproductive justice in an era of Gates and Modi – the violence of India’s population policies

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    This article addresses India’s contemporary population control policies and practices as a form of gendered violence perpetrated by the state and transnational actors, arguing that the targeting of poor, Adivasi and Dalit women for coercive mass sterilizations and unsafe injectable and implantable contraceptives is made possible by the long-term construction of particular women’s lives as devalued and disposable, and of their bodies as excessively fertile and therefore inimical to development and progress. It further considers how population policy is currently embedded in the neoliberal framework of development being pursued by the Indian state. In particular, it argues that the violence of population policies is being deepened as a result of three central and interrelated aspects of this framework: corporate dispossession and displacement, the intensification and extension of women’s labour for global capital, and the discourses and embodied practices of Hindu supremacism. At the same time, India’s population policies cannot be understood in isolation from the global population control establishment, which is increasingly corporate led, and from broader structures of racialised global capital accumulation. The gendered violence of India’s contemporary population policies and the practices they produce operates at several different scales, all of which involve the construction of certain bodies as ‘unfit’ to reproduce and requiring intervention and control

    Racial differences in human platelet PAR4 reactivity reflect expression of PCTP and miR-376c.

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    Racial differences in the pathophysiology of atherothrombosis are poorly understood. We explored the function and transcriptome of platelets in healthy black (n = 70) and white (n = 84) subjects. Platelet aggregation and calcium mobilization induced by the PAR4 thrombin receptor were significantly greater in black subjects. Numerous differentially expressed RNAs were associated with both race and PAR4 reactivity, including PCTP (encoding phosphatidylcholine transfer protein), and platelets from black subjects expressed higher levels of PC-TP protein. PC-TP inhibition or depletion blocked PAR4- but not PAR1-mediated activation of platelets and megakaryocytic cell lines. miR-376c levels were differentially expressed by race and PAR4 reactivity and were inversely correlated with PCTP mRNA levels, PC-TP protein levels and PAR4 reactivity. miR-376c regulated the expression of PC-TP in human megakaryocytes. A disproportionately high number of microRNAs that were differentially expressed by race and PAR4 reactivity, including miR-376c, are encoded in the DLK1-DIO3 locus and were expressed at lower levels in platelets from black subjects. These results suggest that PC-TP contributes to the racial difference in PAR4-mediated platelet activation, indicate a genomic contribution to platelet function that differs by race and emphasize a need to consider the effects of race when developing anti-thrombotic drugs
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