RESUMEN
Magnetic refrigeration based on the magnetocaloric effect is gaining interest in orthogonal or hexagonal rare-earth manganite. However, a more comprehensive understanding of the underlying mechanism is still required. We grew a high-quality single crystal of Dy0.5Ho0.5MnO3 using the optical floating zone method, since the parent crystals DyMnO3 and HoMnO3 have orthogonal and hexagonal structures, respectively. The magnetic and magnetocaloric properties and refrigeration mechanisms are thoroughly investigated. Doping modifies the magnetism according to the results obtained from the investigation of magnetic and dielectric properties and heat capacity. The spin reorientation transition shifts towards low temperature in comparison to HoMnO3. Near the Néel temperature of rare-earth sublattices (5 K), the highest changes in negative magnetic entropy under 0-70 kOe are 18 J kg-1 K-1 and 13 J kg-1 K-1 along the a- and c-axes, respectively. The low-temperature metamagnetic phase transition caused by the alterations in the magnetic symmetry of Ho3+ contributes to an increased magnetocaloric effect in comparison to the parent crystals, rendering it a promising choice for magnetic refrigeration applications. Dy0.5Ho0.5MnO3 exhibits a clear magnetocrystalline anisotropy with enhanced refrigeration capacity and negative magnetic entropy change along the a-axis. The adiabatic temperature change of Dy0.5Ho0.5MnO3 is 8.5 K, larger than that of HoMnO3, rendering it a promising choice for low-temperature magnetic refrigeration applications.
RESUMEN
Using a mobile phone while participating in traffic is a growing safety concern all over the world. However, mobile phone use (MPU) while riding an e-bike has not yet been given enough attention by researchers and practitioners. To fill this gap, this study conducted a preliminary online interview and a questionnaire-based survey in China to study what kinds of MPU behaviors e-bikers commonly engaged in and the prevalence of these behaviors. A conceptual dual-process framework consisting of e-bikers' demographics, e-bike usage pattern, nomophobia, attitude and self-control was also proposed to analyze the psychological mechanism underlying this phenomenon. The preliminary online interview revealed 7 typical types of MPU behaviors performed by e-bikers on the road. Results of the questionnaire survey showed that though the overall frequencies of MPU behaviors were low, nearly 60% of the respondents reported a history of mobile phone use during riding in the last three months. E-bikers' MPU frequencies were significantly impacted by e-bikers' gender, attitude, self-control and information-related nomophobia. Besides, self-control also significantly moderated the predictive effects of information-related nomophobia and attitude on MPU frequencies while ring an e-bike. Fears of being unable to access information on the mobile phone only contributed to MPU at low levels of self-control. In contrast, the protective effect of unfavorable attitude against engagement in the behavior became stronger at high self-control levels. The results not only offer deeper insights into the current situation of MPU among e-bikers in China, but also could facilitate the development of intervention and safety promotion strategies targeting this specific road user group.
Asunto(s)
Uso del Teléfono Celular , Teléfono Celular , Humanos , Accidentes de Tránsito/prevención & control , Ciclismo , Asunción de Riesgos , MotocicletasRESUMEN
Two new anthraquinone derivatives, alterporriol Y (1) and macrosporin 2-O-α-D-glucopyranoside (2), together with five known analogues (3-7) were isolated from the fungus Stemphylium lycopersici associated with the gorgonian coral Dichotella gemmacea collected from the South China Sea. Their structures were determined on the basis of detailed spectroscopic analysis and comparison with reported data. The absolute configurations were determined by the ECD method. In an in vitro cytotoxic assay, compound 3 and 4 showed potent effects against HCT-116 and MCF-7 cell lines. Compound 4 also exhibited cytotoxicity toward Huh7 stem cell-like cells.
Asunto(s)
Antozoos/microbiología , Antraquinonas/aislamiento & purificación , Antineoplásicos/aislamiento & purificación , Ascomicetos/química , Hongos Mitospóricos/química , Animales , Antraquinonas/química , Antraquinonas/farmacología , Antineoplásicos/química , Antineoplásicos/farmacología , Línea Celular , Línea Celular Tumoral , China , Humanos , Conformación Molecular , Análisis EspectralRESUMEN
Objective: In the last few decades, the growing popularity of e-bikes in China has raised public concerns regarding an increasing number of fatalities and injuries involving e-bikes. Although previous studies have explored the impacts of personality on driving behaviors of automobile drivers and motorcyclists, little attention has been paid to safety-related issues involving e-bikers from the aspect of their personality traits and sociocognitive variables. The aim of this study was to examine the effects of personality on e-bikers' risk-taking behaviors and test the effectiveness of the model proposed by Ulleberg and Rundmo (2003) among e-bikers.Methods: Four hundred and five Chinese e-bikers aged 16 to 61 completed a self-administrated questionnaire, which included questions investigating their demographics, personality traits (anger, altruism, sensation-seeking, normlessness), risk perceptions, safety attitudes, and risky riding behaviors. The reliability and validity of all scales were first examined through reliability analysis and principal component analysis, respectively, and a structural equation model was developed and fitted to test the relationships among e-bikers' personality traits, risk perceptions, safety attitudes, and risky riding.Results: A satisfactory level of reliability and validity was reached for all variables. Anger, altruism, sensation-seeking, and normlessness were all significantly related to e-bikers' risk perceptions and unsafe riding, and only altruism correlated significantly to safety attitude. For 2 sociocognitive variables, safety attitudes was directly and negatively related to respondents' risky riding, and risk perception only exerted impacts on riding behaviors by affecting safety attitudes.Conclusions: Personality traits of e-bikers impacted their riding behaviors both directly and indirectly, and sociocognitive variables played an intermediate role in the personality-behavior relationship. The results revealed the importance of personality traits in influencing e-bikers' risky riding and also verified the applicability of the personality-behavior model proposed by Ulleberg and Rundmo (2003) among e-bikers. The findings of this study may provide an empirical basis for evidence-based safety interventions for e-bikers in China.
Asunto(s)
Accidentes de Tránsito/psicología , Conducción de Automóvil/psicología , Ciclismo , Motocicletas , Personalidad , Asunción de Riesgos , Accidentes de Tránsito/estadística & datos numéricos , Adolescente , Adulto , Ira , Pueblo Asiatico , Actitud , Conducción de Automóvil/estadística & datos numéricos , China , Estudios Transversales , Femenino , Humanos , Masculino , Persona de Mediana Edad , Modelos Teóricos , Percepción , Reproducibilidad de los Resultados , Encuestas y Cuestionarios , Adulto JovenRESUMEN
In recent years, the increasing rate of road crashes involving cyclists with a disproportionate overrepresentation in injury statistics has become a major concern in road safety and public health. However, much remains unknown about factors contributing to cyclists' high crash rates, especially those related to personal characteristics. This study aims to explore the influence of cyclist personality traits and cycling behaviors on their road safety outcomes using a mediated model combining these constructs. A total of 628 cyclists completed an online questionnaire consisting of questions related to cycling anger, impulsiveness, normlessness, sensation seeking, risky cycling behaviors, and involvement in crash-related conditions in the past year. After the psychometric properties of the employed scales were examined, the relationships among the tested constructs were investigated using structural equation modeling. The results showed that cyclists' crash risks were directly predicted by risky cycling behaviors and cycling anger, and the effects of cycling anger, impulsiveness, as well as normlessness on crash risks, were mediated by cycling behaviors. The current findings provide insight into the importance of personality traits in impacting cycling safety and could facilitate the development of evidence-based prevention and promotion strategies targeting cyclists in China.
Asunto(s)
Accidentes de Tránsito/estadística & datos numéricos , Ciclismo/estadística & datos numéricos , Personalidad , Asunción de Riesgos , Accidentes de Tránsito/psicología , Adolescente , Adulto , Ira , Ciclismo/psicología , China , Femenino , Humanos , Masculino , Persona de Mediana Edad , Psicometría , Factores Socioeconómicos , Adulto JovenRESUMEN
OBJECTIVE: Illegal parking in emergency lanes (paved highway shoulders) is becoming a serious road safety issue in China. The aim of this study was to (1) examine the utility of the theory of planned behavior (TPB) extended with descriptive norms, past behavior, facilitating and deterring circumstances, sensation seeking, and invulnerability in predicting Chinese drivers' intentions toward illegal emergency lane parking; (2) investigate whether respondents' demographic characteristics would impact their views toward the behavior and predictive patterns of intentions; and (3) identify significant predictors of intentions. METHODS: In this cross-sectional study, eligible respondents were all qualified Chinese drivers. A self-administered questionnaire was employed to collect data, including demographic information, descriptive norms, past behavior, facilitating and deterring circumstances, sensation-seeking, and scenario-based invulnerability combined with TPB constructs. Descriptive statistics, multivariate analyses of variance (MANOVAs), and a series of hierarchical multiple linear regression analyses were conducted in SPSS. RESULTS: A total of 435 qualified drivers (234 males and 201 females) with a mean age of 35.2 years (SD =10.3) were included in analysis. The descriptive analysis showed that most participants reported weak intentions (M = 2.35) to park illegally in emergency lanes with negative attitude (M = 3.19), low perceived support (M = 2.91), and high control (M = 5.08) over the behavior. The model succeeded in explaining 64% of the variance in intentions for the whole sample, and principal TPB components accounted for 21% of variance in intentions after demographic variables were controlled for. MANOVAs revealed that significant differences of respondents' opinions toward illegal emergency lane parking were only found between better educated drivers (with college education background) and less-educated ones. Separate regression analyses revealed that the predictive pattern of better educated participants also differed significantly from that of less-educated ones. CONCLUSION: The study revealed that perceived behavioral control, past behavior, facilitating circumstance, and invulnerability emerged as consistently significant predictors of Chinese drivers' intentions to park illegally in emergency lanes. Findings of this study may have some practical implications in developing multifaceted interventions or education processes for illegal emergency lane parking in China.