The Experts below are selected from a list of 4623 Experts worldwide ranked by ideXlab platform
Jianbo Cheng - One of the best experts on this subject based on the ideXlab platform.
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how do organic gold Compounds and organic Halogen molecules interact comparison with hydrogen bonds
RSC Advances, 2015Co-Authors: Meng Gao, Jianbo ChengAbstract:An Au⋯X interaction has been predicted in the complexes between the organic gold Compound RAu (R = CH3, C2H3, and C2H) and the organic Halogen Compound R′X (R′ = CH3, C2H, C2H3, and CF3; X = Cl, Br, and I) using quantum chemical calculations. Upon the basis of the anisotropic distribution of molecular electrostatic potentials on the Au and X atoms, two types of structures, represented as GB and XB, respectively, were obtained. In the GB structure, the Au atom acts as a Lewis acid and X is a Lewis base, but reversed roles are found for Au and X in XB. Interestingly, the former structure is far more stable than the latter one. Their difference in stability can be regulated by the substitution and hybridization effects, similarly to those in hydrogen bonds. The partially covalent-interaction nature of GBs was characterized with the large charge transfer and the negative energy density as well as the high interaction energy. GB interaction is dominated by electrostatic and polarization energies, whereas electrostatic and dispersion energies are responsible for the stability of most XB complexes. This is an interesting finding that both patterns of interactions are different in nature even though the two monomers are only different in the spatial orientation for both interactions.
Etienne Thiry - One of the best experts on this subject based on the ideXlab platform.
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Comparative Virucidal Efficacy of Seven Disinfectants Against Murine Norovirus and Feline Calicivirus, Surrogates of Human Norovirus
Food and Environmental Virology, 2016Co-Authors: William Zonta, Axel Mauroy, Frederic Farnir, Etienne ThiryAbstract:Human noroviruses (HuNoV) are the leading cause of acute non-bacterial gastroenteritis in humans and can be transmitted either by person-to-person contact or by consumption of contaminated food. A knowledge of an efficient disinfection for both hands and food-contact surfaces is helpful for the food sector and provides precious information for public health. The aim of this study was to evaluate the effect of seven disinfectants belonging to different groups of biocides (alcohol, Halogen, oxidizing agents, quaternary ammonium Compounds, aldehyde and biguanide) on infectious viral titre and on genomic copy number. Due to the absence of a cell culture system for HuNoV, two HuNoV surrogates, such as murine norovirus and feline calicivirus, were used and the tests were performed in suspension, on gloves and on stainless steel discs. When, as criteria of efficacy, a log reduction >3 of the infectious viral titre on both surrogates and in the three tests is used, the most efficacious disinfectants in this study appear to be biocidal products B, C and D, representing the Halogens, the oxidizing agents group and a mix of QAC, alcohol and aldehyde, respectively. In addition, these three disinfectants also elicited a significant effect on genomic copy number for both surrogate viruses and in all three tests. The results of this study demonstrate that a Halogen Compound, oxidizing agents and a mix of QAC, alcohol and aldehyde are advisable for HuNoV disinfection of either potentially contaminated surfaces or materials in contact with foodstuffs.
Rachel E. Marschang - One of the best experts on this subject based on the ideXlab platform.
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Comparison of the Sensitivities of Noroviruses and Feline Calicivirus to Chemical Disinfection under Field-Like Conditions
Applied and Environmental Microbiology, 2007Co-Authors: Lorenza Ferrero Poschetto, Tibor Papp, Ulrich Mohn, Reinhard Böhm, Rachel E. MarschangAbstract:Noroviruses (NV), in the family Caliciviridae, are an important cause of gastroenteritis in humans worldwide. Measures for prevention and control of NV dissemination are therefore necessary to ensure public safety. The abilities of an organic acid (Venno Vet 1 Super), an aldehyde (Venno FF Super), a Halogen Compound (sodium hypochlorite solution), and a peroxide (Oxystrong FG) to inactivate feline calicivirus (FCV), a cultivable virus surrogate for NV, were studied. Molecular protocols were then used for the comparative evaluation of disinfectant efficacies against NV and FCV, which were tested by reproducing NV field conditions, using human fecal material as a protein load. Generally, disinfectant efficacy was strongly reduced by the organic impurities (feces) used during tests. All disinfectants, except the aldehyde, were effective on FCV, as measured by cell culture and reverse transcription-PCR (RT-PCR), with inactivation levels of ≥99.9%. The glutaraldehyde-based Compound failed to adequately inactivate FCV according to RT-PCR results, although the infectivity in cell culture was completely abolished. Similar inactivation levels were achieved with NV, but generally NV appeared more resistant than FCV, and consequently, the suitability of FCV as a model for NV should be considered with caution. In conclusion, according to RT-PCR results, 5% Venno Vet 1 Super, 1% Oxystrong FG, and not less than 2% Venno FF Super, with a contact time of 1 h, and 1% sodium hypochlorite, with 6,000 ppm of free chlorine and a contact time of 15 min, are required for safe disinfection when a calicivirus-related outbreak is suspected.
Irene Stemmler - One of the best experts on this subject based on the ideXlab platform.
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methyl iodide production in the open ocean
Biogeosciences, 2014Co-Authors: Irene Stemmler, Inga Hense, Birgit Quack, Ernst MaierreimerAbstract:Production pathways of the prominent volatile organic Halogen Compound methyl iodide (CH3I) are not fully understood. Based on observations, production of CH3I via photochemical degradation of organic material or via phytoplankton production has been proposed. Additional insights could not be gained from correlations between observed biological and environmental variables or from biogeochemical modeling to identify unambiguously the source of methyl iodide. In this study, we aim to address this question of source mechanisms with a three-dimensional global ocean general circulation model including biogeochemistry (MPIOM-HAMOCC (MPIOM - Max Planck Institute Ocean Model HAMOCC - HAMburg Ocean Carbon Cycle model)) by carrying out a series of sensitivity experiments. The simulated fields are compared with a newly available global data set. Simulated distribution patterns and emissions of CH3I differ largely for the two different production pathways. The evaluation of our model results with observations shows that, on the global scale, observed surface concentrations of CH3I can be best explained by the photochemical production pathway. Our results further emphasize that correlations between CH3I and abiotic or biotic factors do not necessarily provide meaningful insights concerning the source of origin. Overall, we find a net global annual CH3I air-sea flux that ranges between 70 and 260 Gg yr(-1). On the global scale, the ocean acts as a net source of methyl iodide for the atmosphere, though in some regions in boreal winter, fluxes are of the opposite direction (from the atmosphere to the ocean).
Markus Nagl - One of the best experts on this subject based on the ideXlab platform.
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Superior bactericidal activity of N-bromine Compounds compared to their N-chlorine analogues can be reversed under protein load.
Journal of applied microbiology, 2014Co-Authors: Waldemar Gottardi, S. Klotz, Markus NaglAbstract:AIMS To investigate and compare the bactericidal activity (BA) of active bromine and chlorine Compounds in the absence and presence of protein load. METHODS AND RESULTS Quantitative killing tests against Escherichia coli and Staphylococcus aureus were performed both in the absence and in the presence of peptone with pairs of isosteric active chlorine and bromine Compounds: hypochlorous and hypobromous acid (HOCl and HOBr), dichloro- and dibromoisocyanuric acid, chlorantine and bromantine (1,3-dibromo- and 1,3 dichloro-5,5-dimethylhydantoine), chloramine T and bromamine T (N-chloro- and N-bromo-4-methylbenzenesulphonamide sodium), and N-chloro- and N-bromotaurine sodium. To classify the bactericidal activities on a quantitative basis, an empirical coefficient named specific bactericidal activity (SBA), founded on the parameters of killing curves, was defined: SBA= mean log reductions/(mean exposure times x concentration) [mmol 1(-1) min (-1)]. In the absence of peptone, tests with washed micro-organisms revealed a throughout higher BA of bromine Compounds with only slight differences between single substances. This was in contrast to chlorine Compounds, whose killing times differed by a factor of more than four decimal powers. As a consequence, also the isosteric pairs showed according differences. In the presence of peptone, however, bromine Compounds showed an increased loss of BA, which partly caused a reversal of efficacy within isosteric pairs. CONCLUSIONS In medical practice, weakly oxidizing active chlorine Compounds like chloramines have the highest potential as topical anti-infectives in the presence of proteinaceous material (mucous membranes, open wounds). Active bromine Compounds, on the other hand, have their chance at insensitive body regions with low organic matter, for example skin surfaces. SIGNIFICANCE AND IMPACT OF THE STUDY The expected protein load is one of the most important parameters for selection of a suited active Halogen Compound.
