541 research outputs found

    Photophysics of some styryl thiazolo quinoxaline dyes in organic media

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    The photophysics of a new class of styryl dyes, 2-styryl thiazolo quinoxaline (STQ) based structures was investigated in organic solvents and organized molecular assemblies. The absorption, steady state and time-resolved fluorescence characteristics of the STQ dyes in low-viscosity organic solvents are consistent with a single species in the ground and excited state. The one electron electrochemical oxidation and reduction potentials of the dyes are within ±1V vs. NHE. The spectral shifts of the dyes in organic solvents are linearly correlated with the variation of solvent polarity parameters. The dipole moments in the ground and excited state of the dyes were calculated without assuming a value for the cavity radius. The temperature dependence of the nonradiative rate of STQ dye in DMSO indicated an activation barrier (ΔE=10.7 kJ/mol) which is comparable to the activation energy (Ea=13.7 kJ/mol) of viscous friction in DMSO. In dichloromethane, the activation barrier is 34.0 kJ/mol which is very high compared to Ea=6.64 kJ/mol. Formation of a dye–solvent complex is suggested in dichloromethane. The fluorescence decay of STQ dye is multiexponential in a viscous solvent (2-octanol) or when bound to a protein (Lysozyme), micelle or lipid membrane. In 2-octanol, the decay parameters are wavelength dependent and the results are consistent with the mechanism of excited state kinetics of solvent relaxation. In other systems, the multiexponential decay is due to multiple sites of solubilization of the dye in the organized molecular assembly

    User Feedback Analysis System using Natural Language Processing and Artificial Intelligence

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    The Web has dramatically changed the way that people express their views and opinions. Now if one wants to purchase a product, he/she is no longer limited to asking his/her friends and families because there are many product reviews on the Web which give opinions of existing users of the product. Here we present the system which provides us information about such products and services in summarization form. Finding opinion sources and monitoring them on the Web can still be a difficult task because there are a large number of diffrent sources, and each source may also have a huge volume of opinionated text (text with opinions or sentiments). In most cases, opinions are hidden in long forum posts and blogs. It is complicated for a human reader to find relable sources, extract related sentences with opinions, read them, summarize them, and manage them into usable forms. Thus, automated summarization systems are needed. Using this summarization we can recognize the importance, quality, popularity of product and services. In this system we make summarization for product. But, we can use this system anywhere, where text analysis is required. Sentiment analysis, also known as opinion mining, grows out of this need. It is a challenging natural language processing or text mining problem. Due to its tremendous value for practical applications, there has been an excessive growth of both research in academia and applications in the industry

    Effect of different shading intensities on growth and yield of cherry tomato

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    Cherry tomato (Solanum lycopersicon var cerasiforme) is small size fruits, with a bright red colour resembling to cherry and becoming popular in the retail chains which are marketed at a premium price. The field experiment was conducted to study the effect of different (35, 50 and 75 per cent) shading intensities on growth and yield (qha-1 ) of cherry tomato. Significantly maximum yield was recorded in 35 per cent shading intensity and genotype Kalash Seeds Product (KSP)-113 (579.44 and 503.88 q ha-1 , respectively). Among the different shading intensities and genotypes, maximum plant height was observed in 75 per cent shading intensity and genotype KSP -113 at 30 days interval (74.70 and 60.95 cm, respectively). The minimum days to 50% flowering of cherry tomato were observed in cherry tomatoes grown under 35 per cent shading intensity (45.00 days) as compared to other shading intensities while minimum days to 50% flowering were observed in genotype KSP-113 (44.00 days). The maximum length of the cluster (9.58 cm), the weight of cluster (27.67 g), number of fruits per cluster (9.42) and number of pickings (11.67) were observed in 35 per cent shading intensities and in genotype KSP-113. The cultivation of KSP-113 genotype under 35 per cent shading intensity was found to be most sustainable for improving growth and yield of cherry tomato during the summer season

    Biosynthesis of strychnine

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    Dynamic Phase Transition from Localized to Spatiotemporal Chaos in Coupled Circle Map with Feedback

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    We investigate coupled circle maps in presence of feedback and explore various dynamical phases observed in this system of coupled high dimensional maps. We observe an interesting transition from localized chaos to spatiotemporal chaos. We study this transition as a dynamic phase transition. We observe that persistence acts as an excellent quantifier to describe this transition. Taking the location of the fixed point of circle map (which does not change with feedback) as a reference point, we compute number of sites which have been greater than (less than) the fixed point till time t. Though local dynamics is high-dimensional in this case this definition of persistence which tracks a single variable is an excellent quantifier for this transition. In most cases, we also obtain a well defined persistence exponent at the critical point and observe conventional scaling as seen in second order phase transitions. This indicates that persistence could work as good order parameter for transitions from fully or partially arrested phase. We also give an explanation of gaps in eigenvalue spectrum of the Jacobian of localized state

    TITLE PAGE α-AMINOAZAHETEROCYCLIC-METHYLGLYOXAL ADDUCTS DO NOT INHIBIT CFTR CHLORIDE CHANNEL ACTIVITY

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    ABSTRACT Inhibitors of the cystic fibrosis transmembrane conductance regulator (CFTR) chloride channel have potential applications in the therapy of secretory diarrheas and polycystic kidney disease. Recently, several highly polar α-aminoazaheterocyclic-methylglyoxal adducts were reported to reversibly inhibit CFTR chloride channel activity with IC50 values in the low picomolar range (Routaboul et al. J. Pharmacol. Exp. Ther. 322:1023-1035, more than 10,000-fold better than that of thiazolidionone and glycine hydrazide CFTR inhibitors identified previously by highthroughout screening. Here, we resynthesized and evaluated the α-aminoazaheterocyclicmethylglyoxal adducts of Routaboul et al. reported to have high CFTR inhibition potency (compounds 5, 7 and 8). We verified that the reported synthesis procedures produced the target compounds in high yield. However, we found that these compounds did not inhibit CFTR chloride channel function in multiple cell lines at up to 100 µM concentration, using three independent assays of CFTR function including short-circuit current analysis, whole-cell patch-clamp and YFPfluorescence quenching. As positive controls, near 100% CFTR inhibition was found by thiazolidionone and glycine hydrazide CFTR inhibitors. Our data provide direct evidence against CFTR inhibition by α-aminoazaheterocyclic-methylglyoxal adducts

    Simultaneous estimation of simvastatin and labetalol in bulk and solid dosage form

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    A simple, accurate, precise, sensitive, and highly selective ultra violet spectrometer method has been developed for the simultaneous estimation of simvastatin and labetalol in bulk and solid dosage form. The estimation of simvastatin was carried out at 239 nm while labetalol was estimated at 222.4 nm. The developed method was validated for linearity range, precision, recovery studies and interference study for mixture, all these parameter showed the adaptability of the method for the method quality analysis of the drug in bulk and combination formulation. Keywords: Simvastatin, Labetalol, UV Spectrophotometric, Dosage form

    Characterization of CDK(5) Inhibitor, 20-223 (aka CP668863) for Colorectal Cancer Therapy

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    Colorectal cancer (CRC) remains one of the leading causes of cancer related deaths in the United States. Currently, there are limited therapeutic options for patients suffering from CRC, none of which focus on the cell signaling mechanisms controlled by the popular kinase family, cyclin dependent kinases (CDKs). Here we evaluate a Pfizer developed compound, CP668863, that inhibits cyclin-dependent kinase 5 (CDK5) in neurodegenerative disorders. CDK5 has been implicated in a number of cancers, most recently as an oncogene in colorectal cancers. Our lab synthesized and characterized CP668863 – now called 20-223. In our established colorectal cancer xenograft model, 20-223 reduced tumor growth and tumor weight indicating its value as a potential anti-CRC agent. We subjected 20-223 to a series of cell-free and cell-based studies to understand the mechanism of its anti-tumor effects. In our hands, in vitro 20-223 is most potent against CDK2 and CDK5. The clinically used CDK inhibitor AT7519 and 20-223 share the aminopyrazole core and we used it to benchmark the 20-223 potency. In CDK5 and CDK2 kinase assays, 20-223 was ~3.5-fold and ~65.3-fold more potent than known clinically used CDK inhibitor, AT7519, respectively. Cell-based studies examining phosphorylation of downstream substrates revealed 20-223 inhibits the kinase activity of CDK5 and CDK2 in multiple CRC cell lines. Consistent with CDK5 inhibition, 20-223 inhibited migration of CRC cells in a wound-healing assay. Profiling a panel of CRC cell lines for growth inhibitory effects showed that 20-223 has nanomolar potency across multiple CRC cell lines and was on an average \u3e2-fold more potent than AT7519. Cell cycle analyses in CRC cells revealed that 20-223 phenocopied the effects associated with AT7519. Collectively, these findings suggest that 20-223 exerts anti-tumor effects against CRC by targeting CDK 2/5 and inducing cell cycle arrest. Our studies also indicate that 20-223 is a suitable lead compound for colorectal cancer therapy
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