31 research outputs found

    Tobacco chewing and female oral cavity cancer risk in Karunagappally cohort, India

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    This study examined oral cancer in a cohort of 78 140 women aged 30–84 years in Karunagappally, Kerala, India, on whom baseline information was collected on lifestyle, including tobacco chewing, and sociodemographic factors during the period 1990–1997. By the end of 2005, 92 oral cancer cases were identified by the Karunagappally Cancer Registry. Poisson regression analysis of grouped data, taking into account age and income, showed that oral cancer incidence was strongly related to daily frequency of tobacco chewing (P<0.001) and was increased 9.2-fold among women chewing tobacco 10 times or more a day. The risk increased with the duration of tobacco chewing during the first 20 years of tobacco chewing. Age at starting tobacco chewing was not significantly related to oral cancer risk. This is the first cohort study of oral cancer in relation to tobacco chewing among women

    Measurement of 100Mo (n, 2n) 99Mo reaction cross section and covariance analysis using extended unscented transformation technique at the incident neutron energy of 13.9 MeV

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    351-357In this paper, the measurement and covariance analysis of the cross section of 100Mo (n, 2n) 99Mo reaction, with the 197Au (n, 2n)196 Au reaction being used as the monitor, at the incident neutron energy of 13.9 MeV is reported. The 3H (d, n) 4He nuclear reaction is used as the neutron source. The experiment was performed at the Purnima neutron facility, BARC. The method of activation with off-line -ray spectrometry is used. The covariance analysis of the 100Mo (n, 2n) 99Mo reaction is also performed, for the first time, using the extended unscented transformation (EUT) technique1, which is an extension of unscented transformation (UT) technique2, for the determination of partial uncertainties arising due to attributes in combination with the micro-correlation technique of Geraldo and Smith3. The present results obtained for 100Mo (n, 2n) 99Mo reaction cross section are found to be in good agreement with EXFOR data and the theoretically calculated value using the TALYS 1. 8 code. Comparisons with the data in the available basic evaluated nuclear data libraries, such as ENDF/B-VIII.0, JEFF-3.3, JENDL-4.0, ROSFOND-2010, CENDL-3.1 and TENDL 2017 are also presented and discussed

    Measurement of 100Mo (n, 2n) 99Mo reaction cross section and covariance analysis using extended unscented transformation technique at the incident neutron energy of 13.9 MeV

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    In this paper, the measurement and covariance analysis of the cross section of 100Mo (n, 2n) 99Mo reaction, with the 197Au (n, 2n)196 Au reaction being used as the monitor, at the incident neutron energy of 13.9 MeV is reported. The 3H (d, n) 4He nuclear reaction is used as the neutron source. The experiment was performed at the Purnima neutron facility, BARC. The method of activation with off-line -ray spectrometry is used. The covariance analysis of the 100Mo (n, 2n) 99Mo reaction is also performed, for the first time, using the extended unscented transformation (EUT) technique1, which is an extension of unscented transformation (UT) technique2, for the determination of partial uncertainties arising due to attributes in combination with the micro-correlation technique of Geraldo and Smith3. The present results obtained for 100Mo (n, 2n) 99Mo reaction cross section are found to be in good agreement with EXFOR data and the theoretically calculated value using the TALYS 1. 8 code. Comparisons with the data in the available basic evaluated nuclear data libraries, such as ENDF/B-VIII.0, JEFF-3.3, JENDL-4.0, ROSFOND-2010, CENDL-3.1 and TENDL 2017 are also presented and discussed

    COMBINATORIAL EFFECT OF D-AMINOACIDS AND TETRACYCLINE AGAINST PSEUDOMONAS AERUGINOSA BIOFILM

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    Objective: The present study attempted to evaluate the anti-biofilm activity of D-amino acids (D-AAs) on Pseudomonas aeruginosa and determine if the combination of D-AAs with tetracycline enhances the anti-biofilm activity in vitro and ex vivo.Methods: Different D-AAs were tested for antibiofilm activity against wild type P. aeruginosa PAO1 and two multidrug resistant P. aeruginosa clinical strains in the presence of sub inhibitory concentrations of tetracycline using crystal violet microtitre plate assay. Results were further validated using in vitro wound dressing and ex vivo porcine skin models followed by cytotoxicity and hemocompatibility studies.Results: D-tryptophan (5 mmol) showed 61 % reduction in biofilm formation of P. aeruginosa. Interestingly combinatorial effect of 5 mmol D-tryptophan and 0.5 minimum inhibitory concentration (MIC) (7.5µg/ml) tetracycline showed 90% reduction in biofilm formation. 5 mmol D-methionine shows 28 % reduction and combination with tetracycline shows 41% reduction in biofilm formation of P. aeruginosa. D-leucine and D-tyrosine alone or in combination with tetracycline did not show significant anti-biofilm activity. D tryptophan-tetracycline combination could reduce 80 % and 77 % reduction in biofilm formation in two multi drug resistant P. aeruginosa clinical strains. D-tryptophan-tetracycline-combination could also reduce 76% and 66% reduction in biofilm formation in wound dressing model and porcine skin explant respectively. The cytotoxicity and hemocompatibility studies did not show significant toxicity when this combination was used.Conclusion: The results established the potential therapeutic application of D-tryptophan alone or in combination with tetracycline for treating biofilm associated clinical problems caused by P. aeruginosa

    Mitigation of quorum sensing mediated virulence factors of Pseudomonas aeruginosa: the role of Meldrum’s acid activated furan

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    The rapid emergence of drug resistant pathogens is a major threat which has warranted the development of alternative strategies to combat infectious diseases. In this work, we have tested the anti-virulent activity of Meldrum’s acid activated furan (MAF) and 1,3-dimethyl barbituric acid activated furan (BAF) against Chromobacterium violaceum and Pseudomonas aeruginosa. It was found that MAF significantly reduced the violacein production and biofilm formation of C. violaceum at sub-inhibitory concentrations. The quorum sensing (QS) regulated virulence factors of P. aeruginosa including biofilm formation, motility, pigment production, and elastase activity were also found to be reduced considerably at sub-inhibitory concentrations of MAF. Additionally, MAF downregulated the expression of genes in the QS circuitry of P. aeruginosa, demonstrating the potential of MAF in lowering the pathogenicity of P. aeruginosa. In silico studies demonstrated the potential of MAF to compete with the signaling molecules of C. violaceum and P. aeruginosa for the QS receptor interaction. In vivo studies using Caenorhabditis elegans demonstrated the anti-pathogenicity of MAF by enhancing the survival of P. aeruginosa-infected C. elegans. These results suggest that activated furan compounds could be potential inhibitors of QS-mediated virulence factors in C. violaceum and P. aeruginosa, encouraging their use in combating multidrug-resistant pathogens

    Regression analysis of experimental reaction cross-section data of

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    Pre-processing of neutron reaction cross-section is essential in the nuclear data evaluation. This work aims to pre-process experimental cross-section data of 241 Am (n, 2n) 240 Am neutron reaction. Pre-processing of the experimental data includes re-normalization, removal of the outliers, integrating multiple cross-section values at single energy to single cross-section value, and regression on the cleaned experimental data. To remove outliers from the data, standardized residual and studentized residual have been used. For integration of multiple cross-section values to single cross-section value, the weighted average method has been used. Regression on the cleaned experimental data has been accomplished using the Gaussian Process Regression (GPR) and Polynomial Regression (PR), and the performance of both regression methods has been studied using statistical indices such as the determination of coefficient (R2) and the sum of the square of residual (SSres)
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