4,418 research outputs found

    Process Intensification of Nicotinic Acid Production via Enzymatic Conversion using Reactive Extraction

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    Nicotinic acid is widely used in the food, pharmaceutical and biochemical industries. Compared to chemical methods, enzymatic conversion of 3-cyanopyridine is an advantageous alternative for the production of nicotinic acid and nicotinamide. The separation of the product is complicated, owing to its high dilution rate in fermentation broth and high cost. Reactive liquid-liquid extraction by a suitable extractant system has been found to be a promising alternative to the other conventional separation techniques. This paper gives a state-of-the-art review for manufacturing processes (chemical and enzymatic) of nicotinic acid and nicotinamide. It also focuses on the most efficient separation technique, reactive extraction. Reactive extraction has advantages of less consumption of material and energy. It also avoids product inhibition and increases the separation selectivity

    Transcriptional Control of Impaired Th1 Responses in Patent Lymphatic Filariasis by T-Box Expressed in T Cells and Suppressor of Cytokine Signaling Genes

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    T-bet (T-box expressed in T cells) and GATA-3 are transcription factors that play a critical role in the development of Th1 and Th2 cells, as do genes of the SOCS (suppressor of cytokine signaling) family, albeit indirectly. Another transcription factor, Foxp3, is a master regulator of natural regulatory T cells (Tregs). To identify the role of these factors in impaired Th1 responses of patent filarial infection, analysis of cytokine, SOCS, and transcription factor mRNA expression was performed on purified T cells of filaria-infected individuals (n � 6) and uninfected controls (n � 6). As expected (and in contrast to cells of uninfected individuals), there was a significant depression of gamma interferon (IFN-�) and a concomitant increase in interleukin-4 (IL-4), IL-5, and IL-10 mRNA expression following stimulation with parasite antigen (BmA) but not with a polyclonal T-cell (anti-CD3) stimulus. T-bet (but not GATA-3) was expressed at significantly lower levels in cells of filaria-infected individuals in response to BmA compared with those from the uninfected group, accounting, at least partially, for the diminished IFN-� expression. Second, we found no significant differences in expression of Foxp3 between the two groups, although induction of Foxp3 expression correlated with induced expression levels of IL-10, implicating Tregs in the IL-10 expression seen. Finally, parasitespecific T-cell expression of SOCS-1, SOCS-5, and SOCS-7 was significantly diminished among infected patients; in contrast, expression of SOCS-3 increased. Our data therefore indicate that the impaired Th1 responses observed in patent lymphatic filariasis are associated with decreased expression of T-bet, SOCS-1, SOCS-5, and SOCS-7 and increased expression of SOCS-3 in T cells

    Modeling charge transport in Swept Charge Devices for X-ray spectroscopy

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    We present the formulation of an analytical model which simulates charge transport in Swept Charge Devices (SCDs) to understand the nature of the spectral redistribution function (SRF). We attempt to construct the energy-dependent and position dependent SRF by modeling the photon interaction, charge cloud generation and various loss mechanisms viz., recombination, partial charge collection and split events. The model will help in optimizing event selection, maximize event recovery and improve spectral modeling for Chandrayaan-2 (slated for launch in 2014). A proto-type physical model is developed and the algorithm along with its results are discussed in this paper.Comment: 9 pages, 7 figures, Proc. SPIE 8453, High Energy, Optical, and Infrared Detectors for Astronomy

    Influence of gas flow rate on liquid distribution in trickle-beds using perforated plates as liquid distributors

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    Two wire mesh tomography devices and a liquid collector were used to study the influence of the gas flow rate on liquid distribution when fluids distribution on top of the reactor is ensured by a perforated plate. In opposition to most of the studies realized by other authors, conditions in which the gas has a negative impact in liquid distribution were evidenced. Indeed, the obtained results show that the influence of gas flow rate depends on the quality of the initial distribution, as the gas forces the liquid to "respect" the distribution imposed at the top of the reactor. Finally, a comparison between the two measuring techniques shows the limitations of the liquid collector and the improper conclusions to which its use could lead

    Low Energy Neutrino Physics after SNO and KamLAND

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    In the recent years important discoveries in the field of low energy neutrino physics (Eν_\nu in the \approx MeV range) have been achieved. Results of the solar neutrino experiment SNO show clearly flavor transitions from νe\nu_e to νμ,τ\nu_{\mu,\tau}. In addition, the long standing solar neutrino problem is basically solved. With KamLAND, an experiment measuring neutrinos emitted from nuclear reactors at large distances, evidence for neutrino oscillations has been found. The values for the oscillation parameters, amplitude and phase, have been restricted. In this paper the potential of future projects in low energy neutrino physics is discussed. This encompasses future solar and reactor experiments as well as the direct search for neutrino masses. Finally the potential of a large liquid scintillator detector in an underground laboratory for supernova neutrino detection, solar neutrino detection, and the search for proton decay pK+νp \to K^+ \nu is discussed.Comment: Invited brief review, World Scientific Publishing Compan

    Finger Ridge Count Correlations Among Four Tribes of Andhra Pradesh, India

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    The present paper reports the distribution of finger ridge count correlations among four tribal populations from Andhra Pradesh, India viz., Dulia, Kotia, Manne Dora and Manzai Mali, and examines the intra and inter population variation. Higher correlations are recorded in left hands compared to right hands, but they are not significant. The homologous fingers exhibit a stronger correlation. In all the tribes, the correlations between right hand fingers are relatively higher among women when compared to men. Regarding inter population variation Dulia men differ significantly from the men of Manne Dora and the Manzai Mali tribes, and Kotia women also differ from the women of the Manne Dora significantly. The average correlation coefficient of the present populations is similar to other Indian populations reported earlier but lower than African and European populations
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