RESUMEN

A new Lysinibacillus fusiformis strain with abundant laccase activity was isolated from soil under forest rotted leaf and identified as L. fusiformis W11 based on its 16S rRNA gene sequence and physiological characteristics. The laccase LfuLac was purified and characterized. The optimum temperature and pH of LfuLac on guaiacol were 45 °C and pH 9, respectively. LfuLac kept 78%, 88%, 92%, 74%, and 47% of activity at pH 7-11, respectively, suggesting the alkali resistance of the enzyme. The effects of various metal ions on LfuLac showed that Cu2+, Mg2+, and Na+ were beneficial to laccase activity and 10 mM Cu2+ increased the activity of LfuLac to 216%. LfuLac showed about 90% activity at 5% organic solvents and more than 60% activity at 20%, indicating its resistance to organic solvents. In addition, LfuLac decolorized different kinds of dyes. This study enriched our knowledge about laccase from L. fusiformis W11 and its potential industrial applications.

Asunto(s)

RESUMEN

Abstract Moral hazard clearly exists among doctors, and it has a dramatic impact on doctor-patient relationships, medical costs and medical risks. This study explored the factors that lead to doctor moral hazard, as well as the interrelationships and internal regularity of these factors. This study takes doctor moral hazard as the research content and the inducing factors as the core theme, conducting grounded theory research on the causes of doctor moral hazard. Scientific understanding of doctor behavior would facilitate the prevention and control of doctor moral hazard behavior. This study used the principles and methodology of Glaser and Strauss's grounded theory. Theoretical and snowball samplings were used to identify 24 subjects. Semi-structured in-depth interviews were conducted with each subject. Themes were identified through substantial (open) coding and theoretical coding. The factors that lead to doctor moral hazard were categorized into five dimensions, i.e. motivation, opportunity, self-rationalization, exposure and punishment. These five factors influence each other, forming the inducing mechanism of doctor moral hazard. This will provide useful theoretical support and method guidance for the follow-up prevention and control of moral hazard for doctors.

Resumo O risco moral existe claramente entre os médicos e tem um impacto dramático nas relações médico-paciente, custos e riscos médicos. Este estudo explorou os fatores que levam ao risco moral por parte do médico, bem como as inter-relações e a regularidade interna desses fatores. Este estudo considera o risco moral do médico como o conteúdo da pesquisa e os fatores indutores como o tema central, conduzindo pesquisas de teoria fundamentada sobre as causas do risco moral do médico. A compreensão científica do comportamento do médico facilitaria a prevenção e o controle do comportamento de risco moral do médico. Este estudo usou os princípios e a metodologia da teoria fundamentada de Glaser e Strauss. Amostragens teóricas e em snowball foram utilizadas para identificar 24 sujeitos. Entrevistas semiestruturadas em profundidade foram realizadas com cada sujeito. Os temas foram identificados por meio de codificação substancial (aberta) e codificação teórica. Os fatores que levam ao risco moral do médico foram categorizados em cinco dimensões: motivação, oportunidade, autorracionalização, exposição e punição. Esses cinco fatores influenciam-se mutuamente, formando o mecanismo indutor do risco moral médico. Isso fornecerá suporte teórico útil e orientação metodológica para o acompanhamento da prevenção e controle de risco moral para os médicos.

Asunto(s)

RESUMEN

BACKGROUND: Viruses that have spent most of their evolutionary time associated with a single host lineage should have sequences that reflect codivergence of virus and host. Several examples for RNA viruses of host-virus tree congruence are being challenged. DNA viruses, such as mastreviruses, are more likely than RNA viruses to have maintained a record of host lineage association. RESULTS: The full genomes of 28 isolates of Wheat dwarf virus (WDV), a member of the Mastrevirus genus, from different regions of China were sequenced. The analysis of these 28 entire genomes and 18 entire genome sequences of cereal mastreviruses from other countries support the designation of wheat, barley and oat mastrevirus isolates as separate species. They revealed that relative divergence times for the viruses WDV, Barley dwarf virus (BDV), Oat dwarf virus (ODV) and Maize streak virus (MSV) are proportional to divergence times of their hosts, suggesting codivergence. Considerable diversity among Chinese isolates was found and was concentrated in hot spots in the Rep A, SIR, LIR, and intron regions in WDV genomes. Two probable recombination events were detected in Chinese WDV isolates. Analysis including further Mastrevirus genomes concentrated on coding regions to avoid difficulties due to recombination and hyperdiversity. The analysis demonstrated congruence of trees in two branches of the genus, but not in the third. Assuming codivergence, an evolutionary rate of 10-8 substitutions per site per year was calculated. The low rate implies stronger constraints against change than are obtained by other methods of estimating the rate. CONCLUSION: We report tests of the hypothesis that mastreviruses have codiverged with their monocotyledonous hosts over 50 million years of evolution. The tests support the hypothesis for WDV, BDV and ODV, but not for MSV and other African streak viruses.

Asunto(s)