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1.
J Youth Adolesc ; 53(8): 1847-1860, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38615131

RESUMO

Parents play a crucial role in adolescents' Internet use. Both general parenting (i.e., autonomy-supportive and controlling parenting) and Internet-specific parenting (i.e., restrictive mediation, active mediation, and parental encouragement) are related to adolescents' online behaviors. However, existing studies have focused either on an Internet-specific parenting or general parenting strategy and have neglected their interaction, failing to capture the intricate nature of the parenting context of youth's online behaviors. Few studies have examined parental encouragement or acknowledged the bidirectional influence of parenting on adolescents' online behaviors. To address this gap, this study employed a cross-lagged panel network model to examine the associations among restrictive and active mediation, parental encouragement, and autonomy-supportive and controlling parenting, as well as the interplay of all five parenting strategies with adolescents' online behaviors. A total of 564 Chinese students (51.1% male; mean age = 14.54, SD = 0.7) completed the survey at two time points. The results indicate that in most cases, previous online behaviors are significant and strong predictors of subsequent parenting strategies and not vice versa, corroborating the child effect. The parent and reciprocal effects were observed in the problematic smartphone-use domain, suggesting that the effects may differ for distinct behavioral domains. The effects of parental mediation extend beyond parental encouragement, implying that risk-prevention-related parenting is an effective means of guiding adolescents' online behaviors. Autonomy-relevant general parenting is closely related to active mediation and parental encouragement, while restrictive general parenting is closely related to restrictive mediation, suggesting a consistency between Internet-specific and general parenting strategies.


Assuntos
Comportamento do Adolescente , Relações Pais-Filho , Poder Familiar , Humanos , Poder Familiar/psicologia , Adolescente , Feminino , Masculino , Comportamento do Adolescente/psicologia , Uso da Internet , Internet , Inquéritos e Questionários , China
2.
Neuroimage ; 279: 120326, 2023 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-37579997

RESUMO

Decisions that require taking effort costs into account are ubiquitous in real life. The neural common currency theory hypothesizes that a particular neural network integrates different costs (e.g., risk) and rewards into a common scale to facilitate value comparison. Although there has been a surge of interest in the computational and neural basis of effort-related value integration, it is still under debate if effort-based decision-making relies on a domain-general valuation network as implicated in the neural common currency theory. Therefore, we comprehensively compared effort-based and risky decision-making using a combination of computational modeling, univariate and multivariate fMRI analyses, and data from two independent studies. We found that effort-based decision-making can be best described by a power discounting model that accounts for both the discounting rate and effort sensitivity. At the neural level, multivariate decoding analyses indicated that the neural patterns of the dorsomedial prefrontal cortex (dmPFC) represented subjective value across different decision-making tasks including either effort or risk costs, although univariate signals were more diverse. These findings suggest that multivariate dmPFC patterns play a critical role in computing subjective value in a task-independent manner and thus extend the scope of the neural common currency theory.


Assuntos
Córtex Pré-Frontal , Recompensa , Humanos , Córtex Pré-Frontal/diagnóstico por imagem , Imageamento por Ressonância Magnética , Tomada de Decisões
3.
Brain ; 145(12): 4210-4221, 2022 12 19.
Artigo em Inglês | MEDLINE | ID: mdl-35861265

RESUMO

Addiction is characterized by compulsive engagement despite adverse consequences. Psychobehavioural interventions targeting compulsivity in addictions are relatively rare, particularly for behavioural addictions like internet gaming disorder (IGD). Free from confounding drug-on-brain effects, IGD provides a promising model for understanding neuropsychological processes of addictions. IGD is a global concern in the setting of increasing internet use worldwide. Thus, developing interventions and understanding their mechanisms of action are important. Positive emotional association biases (EABs) towards addiction cues based on reward conditioning may underlie addiction-associated compulsivity. Here, we developed an EAB modification (EABM) protocol and examined whether modifying EABs via cognitive training would alter neurocognitive aspects of addiction-associated compulsivity in IGD. We recruited 90 IGD participants who were randomly assigned to receive EABM or sham training in a 1:1 ratio (clinicaltrials.gov identifier: NCT04068064). The EABM intervention involved six consecutive days of exposure to negative emotional terms linked to gaming stimuli and positive terms linked to non-gaming healthy-alternative stimuli. The sham training involved similar stimuli linked to neutral words. Participants underwent event-related functional MRI while performing a regulation-of-craving task and received several behavioural assessments pretraining and post-training. Primary efficacy measures were changes in gaming-related positive EABs, and compulsive gaming thoughts and behaviours. Behaviourally, EABM (versus sham) training decreased gaming-related positive EABs and compulsive gaming thoughts and behaviours. Neurally, EABM training involved decreased activation in the bilateral dorsal striatum in the regulation-of-craving task and altered left dorsal striatum-centric functional connectivity with ventral prefrontal cortical regions, which correlated with decreases in gaming-related EABs or compulsive gaming thoughts and behaviours. EABM training also implicated activation changes in the right medial frontal gyrus and posterior insula. EABM may reduce compulsive gaming thoughts and behaviours via reshaping functional organization of frontostriatal pathways and insular activity in IGD. The therapeutic potential of EABM should be examined in larger, longer-term studies, as should its application to other addictive disorders.


Assuntos
Comportamento Aditivo , Jogos de Vídeo , Humanos , Encéfalo , Mapeamento Encefálico/métodos , Imageamento por Ressonância Magnética/métodos , Jogos de Vídeo/efeitos adversos , Jogos de Vídeo/psicologia
4.
Fam Process ; : e12909, 2023 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-37382401

RESUMO

This study examined the reciprocal prospective associations between commitment, forgiveness, and different aspects of marital well-being (marital satisfaction and marital instability) among Chinese newlywed couples and the gender differences in these associations. The Vulnerability-Stress-Adaptation (VSA) model posits reciprocal associations between adaptive processes and relationship satisfaction. However, the directionality of the associations between adaptive processes and marital satisfaction may differ from the associations between adaptive processes and marital instability in Chinese societies due to the emphasis on relationship maintenance. Based on three annual waves of data from 268 Chinese newlywed couples (Mage = 29.59, SD = 3.25 for husbands; Mage = 28.08, SD = 2.51 for wives), a cross-lagged approach was used to examine the reciprocal associations between commitment, forgiveness, and marital satisfaction/instability. We found: (a) reciprocal associations between commitment/forgiveness and marital satisfaction (wives only); (b) reciprocal associations between forgiveness and marital instability (husbands only); and (c) wives' commitment at Wave 2 mediated the association between wives' commitment at Wave 1 and wives' marital satisfaction at Wave 3. Extending the VSA model, findings suggest different reciprocal associations between commitment, forgiveness, and different aspects of marital well-being among Chinese newlywed couples. Results highlight the important role of culture and gender in marital relationships and clinical practice.

5.
Fam Process ; : e12898, 2023 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-37246354

RESUMO

Based on three annual waves of data from 268 Chinese newlyweds (Mage = 29.59, SD = 3.25 for husbands; Mage = 28.08, SD = 2.51 for wives), the present study examined the bidirectional associations between external stressors, perceived spousal support, and marital instability by using a three-wave, cross-lagged approach. Results indicated bidirectional associations between external stressors and marital instability, and a unidirectional association linking marital instability to perceived spousal support. Additionally, external stressors at Wave 2 mediated the association between external stressors at Wave 1 and marital instability at Wave 3. Taken together, the present study contributes to an emerging body of research aimed at clarifying: (a) the directionality of the associations between external stressors, perceived spousal support, and marital instability; (b) how external stressors cumulatively affect the development of marital instability. Our study extends the Vulnerability-Stress-Adaptation (VSA) model and has developmental implications for promoting marital relationships in non-Western couples.

6.
J Youth Adolesc ; 52(6): 1272-1286, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36773189

RESUMO

Establishing autonomy and maintaining relatedness with parents are two of the most crucial goals for adolescents and meeting these goals can be critical for academic and psychological adjustment. A two-dimensional framework was proposed for exploring the integrative synthesis of autonomy and relatedness, but its cultural applicability was limited. To better account for the situations associated with non-Western cultural context, this study extended the prior framework to three dimensions (volition, functional independence, and relatedness) and utilized latent profile analysis to explore the configurations and their concurrent and longitudinal (one year later) associations with adjustment (academic engagement, academic buoyancy, depressive symptoms, and externalizing problems). The study collected data from 3992 Chinese adolescents (51.33% girls, Mage = 15.41, SD = 0.55). Latent profile analyses identified five profiles: High, High Functional Independence, Moderate, Low Functional Independence, and Extremely Low Functional Independence. The High profile was the robust optimal pattern for academic and psychological adjustment, while the Low Functional Independence and Extremely Low Functional Independence were risk patterns over time. The High Functional Independence profile was only conducive to academic areas but not to psychological areas. Findings demonstrated the necessity of the three-dimensional framework in this field.


Assuntos
Desempenho Acadêmico , População do Leste Asiático , Ajustamento Emocional , Relações Pais-Filho , Pais , Autonomia Pessoal , Adolescente , Feminino , Humanos , Masculino , Desempenho Acadêmico/etnologia , Desempenho Acadêmico/psicologia , Sucesso Acadêmico , Povo Asiático , População do Leste Asiático/psicologia , Relações Pais-Filho/etnologia , Pais/psicologia
7.
Curr Psychol ; 42(3): 2514-2528, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-34539155

RESUMO

The present study investigated patterns of adolescent life changes across multiple life domains and utilized a holistic-interactionistic perspective to examine their individual, familial, and societal correlates with a sample of 2544 Chinese parent-adolescent dyads. Adolescents were aged from 10 to 19 years old (50.16% girls). Latent profile analysis revealed five life change profiles, including three improved profiles at various degrees, one unchanged profile, and one worsened profile. The majority of adolescents had an improved or unchanged life. Multinomial logistic regression analyses found that most of the individual, familial, and societal factors predicted the group memberships. Notably, parent-adolescent conflict was a significant factor that predicted memberships of all patterns. These findings show the resilience of adolescents and indicate the need for policies and interventions that consider the holistic nature of adolescents' person-context system, especially during a global crisis such as the COVID-19 pandemic.

8.
Dev Psychopathol ; : 1-12, 2022 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-36345660

RESUMO

Adolescence is a significant period for the formation of relationship networks and the development of internalizing problems. With a sample of Chinese adolescents (N = 3,834, 52.01% girls, Mage = 16.68 at Wave 1), the present study aimed to identify the configuration of adolescents' relationship qualities from four important domains (i.e., relationship quality with mother, father, peers, and teachers) and how distinct profiles were associated with the development of internalizing problems (indicated by depressive and anxiety symptoms) across high school years. Latent profile analysis identified a five-profile configuration with four convergent profiles (i.e., relationship qualities with others were generally good or bad) and one "Father estrangement" profile (i.e., the relationship quality with others were relatively good but that with father was particularly poor). Further conditional latent growth curve analysis indicated the "Father estrangement" profile was especially vulnerable to an increase in the internalizing problems as compared with other relationship profiles. This study contributes to understanding the characteristics of interpersonal relationship qualities and their influences on adolescent internalizing problems in a non-Western context. Results were further discussed from a culturally specific perspective.

9.
Addict Biol ; 26(2): e12917, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-32415913

RESUMO

Alterations in brain connectivity have been implicated in internet gaming disorder (IGD). However, little is known about alterations in whole-brain connectivity and their associations with long-term treatment outcomes. Here, we used a relatively new analytic approach, intrinsic connectivity distribution (ICD) analysis, to examine brain connectivity in 74 IGD participants and 41 matched healthy controls (HCs) and conducted post hoc seed-based resting-state functional connectivity (rsFC) analyses based on the ICD findings. We also examined how these findings related to outcomes involving a craving behavioral intervention (CBI) for IGD. IGD participants showed less whole-brain connectivity in the left angular gyrus and ventromedial prefrontal cortex (vmPFC) compared with HC participants. Seed-based rsFC analyses revealed that the left angular gyrus in the IGD group showed less connectivity with areas involved in the default-mode network and greater connectivity with areas in the salience and executive control networks. CBI was associated with improved connectivity within regions in the default-mode network and regions across the default-mode and salience networks. ICD-identified connectivity differences in the left angular gyrus and vmPFC were related to changes in craving and severity of addiction 6 months after the intervention. The findings suggest that IGD is associated with alterations in brain connectivity that may be sensitive to interventions. Thus, the findings have implications for understanding mechanisms underlying CBI effects and for further treatment development.


Assuntos
Transtorno de Adição à Internet/patologia , Transtorno de Adição à Internet/terapia , Córtex Pré-Frontal/patologia , Psicoterapia/métodos , Comportamento Aditivo/diagnóstico por imagem , Comportamento Aditivo/patologia , Comportamento Aditivo/terapia , Fissura , Humanos , Transtorno de Adição à Internet/diagnóstico por imagem , Imageamento por Ressonância Magnética , Masculino , Córtex Pré-Frontal/diagnóstico por imagem
10.
Addict Biol ; 26(4): e12969, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33047425

RESUMO

Internet gaming disorder (IGD), a worldwide mental health issue, has been widely studied using neuroimaging techniques during the last decade. Although dysfunctions in resting-state functional connectivity have been reported in IGD, mapping relationships from abnormal connectivity patterns to behavioral measures have not been fully investigated. Connectome-based predictive modeling (CPM)-a recently developed machine-learning approach-has been used to examine potential neural mechanisms in addictions and other psychiatric disorders. To identify the resting-state connections associated with IGD, we modified the CPM approach by replacing its core learning algorithm with a support vector machine. Resting-state functional magnetic resonance imaging (fMRI) data were acquired in 72 individuals with IGD and 41 healthy comparison participants. The modified CPM was conducted with respect to classification and regression. A comparison of whole-brain and network-based analyses showed that the default-mode network (DMN) is the most informative network in predicting IGD both in classification (individual identification accuracy = 78.76%) and regression (correspondence between predicted and actual psychometric scale score: r = 0.44, P < 0.001). To facilitate the characterization of the aberrant resting-state activity in the DMN, the identified networks have been mapped into a three-subsystem division of the DMN. Results suggest that individual differences in DMN function at rest could advance our understanding of IGD and variability in disorder etiology and intervention outcomes.


Assuntos
Comportamento Aditivo/fisiopatologia , Conectoma , Transtorno de Adição à Internet/fisiopatologia , Máquina de Vetores de Suporte , Jogos de Vídeo/psicologia , Adulto , Encéfalo/fisiopatologia , Função Executiva , Humanos , Imageamento por Ressonância Magnética , Masculino , Vias Neurais/fisiopatologia , Adulto Jovem
11.
J Adolesc ; 86: 64-76, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33360119

RESUMO

INTRODUCTION: College students are at high risk of problematic internet use (PIU). A great amount of research has focused on the PIU among college students. However, little is known about the change pattern of PIU across the college years. Moreover, how peer internet overuse behavior and peer attitude toward internet overuse work together to shape college students' PIU trajectory, and whether such peer contagion effects are equal for all students remain unclear. The present study used latent growth curve model to examine these issues. METHODS: A total of 2572 Chinese college students (Mage = 18.37, SD = 0.85; 65% girls) participated in the study. They completed questionnaires regarding demographics, peer internet overuse behavior, peer attitude toward internet overuse, and friendship satisfaction at Wave 1, and PIU at Waves 1-4. RESULTS: After controlling for covariates, the findings revealed that (a) PIU slightly increased before the second year of college and then declined rapidly; (b) both peer internet overuse behavior and peer attitude toward internet overuse were related to the PIU at baseline; however, only peer internet overuse behavior was associated with the change of PIU; and (c) the effect of peer internet overuse behavior on PIU change was moderated by friendship satisfaction and gender. CONCLUSIONS: These findings emphasized the dynamic and context-sensitive nature of PIU and clarified how peer contagion unfolded with peer internet overuse behavior and peer attitude toward internet overuse. Theoretical implications and application of these findings are discussed.


Assuntos
Comportamento Aditivo , Uso da Internet , Adolescente , Feminino , Humanos , Masculino , Grupo Associado , Estudantes , Universidades
12.
J Res Adolesc ; 30(1): 234-248, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31215736

RESUMO

Using latent profile analyses and based on two-wave data from 5,388 Chinese adolescents (Mage  = 15.79, SD = 0.66; 51.99% females), this study examined the variety of ways in which adolescents' perceived career-related parental processes (i.e., parental expectations, support, interference, barriers to engagement, and parent-child congruence) may be configured within families and how such configurations may be associated with adolescents' career adaptability and ambivalence one year later. Three meaningful profiles were identified: the "Supportive but not Intrusive" (SNI) profile, the "Unsupportive but not Permissive" (UNP) profile, and the "Ambivalent and Controlling" (AC) profile. Adolescents in the UNP profile reported higher levels of career ambivalence and lower levels of career adaptability than did those in either the SNI or the AC profiles. Implications for career development among Chinese adolescents were discussed.


Assuntos
Escolha da Profissão , Poder Familiar/psicologia , Adolescente , China , Feminino , Humanos , Masculino , Relações Pais-Filho , Inquéritos e Questionários
13.
Fam Process ; 58(2): 478-495, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-29603205

RESUMO

On the basis of three annual waves of data obtained from 268 Chinese couples, we tested an actor-partner interdependence mediation model in which spouses' neuroticism was linked to their own and partners' marital satisfaction through both intrapersonal processes (i.e., marital attribution) and interpersonal processes (i.e., marital aggression). Considering intra- and interpersonal processes simultaneously, four indirect, mediating pathways were identified: Time 1 Wives' Neuroticism → Time 2 Wives' Attribution or Aggression, while controlling for Time 1 Wives' Attribution or Aggression → Time 3 Wives' or Husbands' Marital Satisfaction, while controlling for Time 1 Wives' or Husbands' Marital Satisfaction. This study not only adds to a limited body of research examining why neuroticism is associated with conjugal well-being, but also extends prior research by focusing on Chinese couples and utilizing a longitudinal, dyadic mediation model. Such findings have important practical implications. Couples involving neurotic partners may benefit from interventions based on cognitive-behavioral approaches. When working with couples challenged by neuroticism, practitioners need to help them address dysfunctional interactive patterns as well as distorted cognitive styles.


Sobre la base de tres series de datos anuales obtenidos de 268 parejas chinas, evaluamos un modelo de mediación e interdependencia actor-pareja en el cual el neuroticismo de los cónyuges se conectó con su propia satisfacción conyugal y la de sus parejas mediante procesos intrapersonales (p. ej.: atribución conyugal) y procesos interpersonales (p. ej.: agresión conyugal). Teniendo en cuenta los procesos intrapersonales e interpersonales simultáneamente, se identificaron cuatro vías mediadoras indirectas: Serie 1: Neuroticismo de las esposas → Serie 2: Agresión o atribución de las esposas, mientras se controla la agresión o la atribución de las esposas de la serie 1 → Serie 3: Satisfacción conyugal de las esposas o los esposos, mientras se controla la satisfacción conyugal de las esposas o los esposos de la serie 1. Este estudio no solo aporta a las escasas investigaciones que analizan por qué el neuroticismo está asociado con el bienestar conyugal, sino que también amplía investigaciones previas centrándose en las parejas chinas y utilizando un modelo de mediación diádico y longitudinal. Dichos resultados tienen implicancias prácticas importantes. Las parejas que tienen compañeros neuróticos pueden beneficiarse con intervenciones basadas en enfoques cognitivo-conductuales. Cuando se trabaja con parejas afectadas por el neuroticismo, los médicos necesitan ayudarlas a abordar los patrones interactivos disfuncionales así como los estilos cognitivos distorsionados.


Assuntos
Agressão , Conflito Familiar/psicologia , Casamento/psicologia , Neuroticismo , Satisfação Pessoal , China , Feminino , Humanos , Relações Interpessoais , Masculino , Autorrelato , Cônjuges/psicologia , Inquéritos e Questionários
14.
Addict Biol ; 23(1): 337-346, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-27894158

RESUMO

Psychobehavioral intervention is an effective treatment of Internet addiction, including Internet gaming disorder (IGD). However, the neural mechanisms underlying its efficacy remain unclear. Cortical-ventral striatum (VS) circuitry is a common target of psychobehavioral interventions in drug addiction, and cortical-VS dysfunction has been reported in IGD; hence, the primary aim of the study was to investigate how the VS circuitry responds to psychobehavioral interventions in IGD. In a cross-sectional study, we examined resting-state functional connectivity of the VS in 74 IGD subjects (IGDs) and 41 healthy controls (HCs). In a follow-up craving behavioral intervention (CBI) study, of the 74 IGD subjects, 20 IGD subjects received CBI (CBI+) and 16 IGD subjects did not (CBI-). All participants were scanned twice with similar time interval to assess the effects of CBI. IGD subjects showed greater resting-state functional connectivity of the VS to left inferior parietal lobule (lIPL), right inferior frontal gyrus and left middle frontal gyrus, in positive association with the severity of IGD. Moreover, compared with CBI-, CBI+ showed significantly greater decrease in VS-lIPL connectivity, along with amelioration in addiction severity following the intervention. These findings demonstrated that functional connectivity between VS and lIPL, each presumably mediating gaming craving and attentional bias, may be a potential biomarker of the efficacy of psychobehavioral intervention. These results also suggested that non-invasive techniques such as transcranial magnetic or direct current stimulation targeting the VS-IPL circuitry may be used in the treatment of Internet gaming disorders.


Assuntos
Terapia Comportamental , Comportamento Aditivo/reabilitação , Córtex Cerebral/diagnóstico por imagem , Fissura , Internet , Estriado Ventral/diagnóstico por imagem , Jogos de Vídeo , Comportamento Aditivo/diagnóstico por imagem , Comportamento Aditivo/fisiopatologia , Estudos de Casos e Controles , Córtex Cerebral/fisiopatologia , Estudos Transversais , Neuroimagem Funcional , Humanos , Imageamento por Ressonância Magnética , Masculino , Vias Neurais/diagnóstico por imagem , Vias Neurais/fisiopatologia , Estriado Ventral/fisiopatologia , Adulto Jovem
15.
Fam Process ; 57(1): 195-210, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-27900762

RESUMO

Family factors are closely associated with child developmental outcomes. This study examined the relationship of oppositional defiant disorder (ODD) symptoms and factors at whole family, dyadic, and individual levels in Chinese children. Participants, who were recruited from 14 primary schools in north, east, and south-west China, included 80 father-child dyads and 169 mother-child dyads. Children in the participating dyads were previously diagnosed with ODD. Results revealed that family cohesion/adaptability was indirectly associated with ODD symptoms via parent-child relationship and child emotion regulation. Parent-child relationship affected ODD symptoms directly and indirectly through child emotion regulation. In addition, the effects of family cohesion/adaptability on parent emotion regulation and child emotion regulation were mediated by the parent-child relationship. The tested model provides a comprehensive framework of how family factors at multiple levels are related to child ODD symptoms and highlights the importance of understanding child emotional and behavioral problems within the family context, more specifically within the multiple levels of family relationships.


Assuntos
Transtornos de Deficit da Atenção e do Comportamento Disruptivo/psicologia , Família/psicologia , Relações Pais-Filho , Adolescente , Adulto , Criança , China , Ajustamento Emocional , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
16.
Crit Rev Food Sci Nutr ; 57(2): 275-312, 2017 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-25831407

RESUMO

Most of the physicochemical properties in polymers such as activity and partition coefficients, diffusion coefficients, and their activation with temperature are accessible to direct calculations from first principles. Such predictions are particularly relevant for food packaging as they can be used (1) to demonstrate the compliance or safety of numerous polymer materials and of their constitutive substances (e.g. additives, residues…), when they are used: as containers, coatings, sealants, gaskets, printing inks, etc. (2) or to predict the indirect contamination of food by pollutants (e.g. from recycled polymers, storage ambiance…) (3) or to assess the plasticization of materials in contact by food constituents (e.g. fat matter, aroma…). This review article summarizes the classical and last mechanistic descriptions of diffusion in polymers and discusses the reliability of semi-empirical approaches used for compliance testing both in EU and US. It is concluded that simulation of diffusion in or through polymers is not limited to worst-case assumptions but could also be applied to real cases for risk assessment, designing packaging with low leaching risk or to synthesize plastic additives with low diffusion rates.


Assuntos
Contaminação de Alimentos/prevenção & controle , Embalagem de Alimentos , Armazenamento de Alimentos , Modelos Químicos , Polímeros/química , Absorção Fisico-Química , Adsorção , Fenômenos Químicos , Árvores de Decisões , Difusão , Elastômeros/química , União Europeia , Embalagem de Alimentos/normas , Fricção , Temperatura Alta/efeitos adversos , Hidrodinâmica , Peso Molecular , Fenômenos Físicos , Plásticos/química , Solubilidade , Estados Unidos
17.
Addict Biol ; 22(3): 791-801, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-26732520

RESUMO

Studies conducted in drug addiction suggest a transition in processing of drug-related cues from the ventral to the dorsal component of the striatum. However, this process has not been studied in a behavioral addiction. Assessment of this process in a non-drug addiction can provide insight into the pathophysiology of both substance and behavioral addictions. Thirty-nine male Internet gaming disorder (IGD) subjects and 23 male matched healthy controls (HCs) participated in functional magnetic resonance imaging during performance of a cue-reactivity task involving alternating presentation of Internet gaming-related stimuli (game cues) and general Internet surfing-related stimuli (control cues). Cue-induced neural activations in the ventral and dorsal striatum (DS) were compared between IGD and HC participants. Associations between cue-reactivity within these regions and cue-induced craving and severity and duration of IGD were also explored. IGD participants exhibited higher cue-induced activations within both the ventral and DS when compared with HCs. Within the IGD group, activity within the left ventral striatum (VS) was correlated negatively with cue-induced craving; positive associations were found between activations within the DS (right putamen, pallidum and left caudate) and duration of IGD. Cue-induced activity within the left putamen was negatively associated with right VS volumes among IGD participants. Consistent with studies in substance addictions, our results suggest that a transition from ventral to dorsal striatal processing may occur among individuals with IGD, a condition without the impact of substance intake.


Assuntos
Comportamento Aditivo/fisiopatologia , Corpo Estriado/fisiopatologia , Sinais (Psicologia) , Internet , Jogos de Vídeo , Adulto , Corpo Estriado/diagnóstico por imagem , Humanos , Masculino , Estriado Ventral/diagnóstico por imagem , Estriado Ventral/fisiopatologia , Adulto Jovem
18.
Addict Biol ; 21(3): 743-51, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-25899520

RESUMO

The insula has been implicated in salience processing, craving, and interoception, all of which are critical to the clinical manifestations of drug and behavioral addiction. In this functional magnetic resonance imaging (fMRI) study, we examined resting-state functional connectivity (rsFC) of the insula and its association with Internet gaming characteristics in 74 young adults with Internet gaming disorder (IGD) and 41 age- and gender-matched healthy control subjects (HCs). In comparison with HCs, IGD subjects (IGDs) exhibited enhanced rsFC between the anterior insula and a network of regions including anterior cingulate cortex (ACC), putamen, angular gyrus, and precuneous, which are involved in salience, craving, self-monitoring, and attention. IGDs also demonstrated significantly stronger rsFC between the posterior insula and postcentral gyrus, precentral gyrus, supplemental motor area, and superior temporal gyrus (STG), which are involved in interoception, movement control, and auditory processing. Furthermore, IGD severity was positively associated with connectivity between the anterior insula and angular gyrus, and STG, and with connectivity between the posterior insula and STG. Duration of Internet gaming was positively associated with connectivity between the anterior insula and ACC. These findings highlight a key role of the insula in manifestation of the core symptoms of IGD and the importance to examine functional abnormalities of the anterior and posterior insula separately in IGDs.


Assuntos
Comportamento Aditivo/fisiopatologia , Encéfalo/fisiopatologia , Internet , Jogos de Vídeo , Adulto , Comportamento Aditivo/diagnóstico por imagem , Encéfalo/diagnóstico por imagem , Estudos de Casos e Controles , Córtex Cerebral/diagnóstico por imagem , Córtex Cerebral/fisiopatologia , Lobo Frontal/diagnóstico por imagem , Lobo Frontal/fisiopatologia , Neuroimagem Funcional , Humanos , Imageamento por Ressonância Magnética , Masculino , Córtex Motor/diagnóstico por imagem , Córtex Motor/fisiopatologia , Lobo Parietal/diagnóstico por imagem , Lobo Parietal/fisiopatologia , Índice de Gravidade de Doença , Córtex Somatossensorial/diagnóstico por imagem , Córtex Somatossensorial/fisiopatologia , Lobo Temporal/diagnóstico por imagem , Lobo Temporal/fisiopatologia , Fatores de Tempo , Adulto Jovem
19.
Community Ment Health J ; 52(4): 457-65, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26002087

RESUMO

This study addressed the issue of disclosing HIV status and sexual orientation, and explored the consequences of such disclosures among HIV-positive men who have sex with men (MSM) in China. In-depth individual interviews were conducted with 37 HIV-positive MSM. Of these participants, 3 (8.1%) disclosed neither their HIV status nor their sexual orientation to anyone; 24 (64.9%) voluntarily disclosed both their HIV-positive status and their sexual orientation; 7 (18.9%) voluntarily disclosed their HIV status only, and 3 (8.1%) involuntarily disclosed their HIV status and sexual orientation. Parents, partners, siblings and close friends were the most common disclosure targets. HIV-positive MSM were less likely to disclose their sexual orientation than their HIV status. The positive consequences of disclosure included receiving support, acquiring family care, reducing stress, improving mood and developing more positive values and beliefs. The negative consequences included the participants' perception of rejection and stigma toward themselves and their families. However, the stigma mainly comes from "outsiders" rather than family members and close friends. We did not find any differences with respect to consequences between participants who disclosed their HIV status only and those who disclosed both their HIV status and sexual orientation. In conclusion, partners, siblings and friends were main disclosure targets, and HIV positive MSM preferred to disclose their HIV serostatus than their sexual orientation. Voluntarily disclosing one's HIV status to significant others resulted in more positive consequences than negative consequences. Theses results were informative for developing mental health and coping interventions.


Assuntos
Soropositividade para HIV/psicologia , Homossexualidade Masculina/psicologia , Autorrevelação , Adulto , China , Humanos , Entrevistas como Assunto , Masculino , Adulto Jovem
20.
J Neurosci ; 34(22): 7522-30, 2014 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-24872557

RESUMO

The ability to resist current temptations in favor of long-term benefits is a critical human capacity. Despite the extensive studies on the neural mechanisms of intertemporal choices, how the subjective value of immediate and delayed rewards is represented and compared in the brain remains to be elucidated. The present fMRI study addressed this question by simultaneously and independently manipulating the magnitude of immediate and delayed rewards in an intertemporal decision task, combined with univariate analysis and multiple voxel pattern analysis. We found that activities in the posterior portion of the dorsal medial prefrontal cortex (DmPFC) were modulated by the value of immediate options, whereas activities in the adjacent anterior DmPFC were modulated by the subjective value of delayed options. Brain signal change in the ventral mPFC was positively correlated with the "relative value" (the absolute difference of subjective value between two intertemporal alternatives). In contrast, the dorsal anterior cingulate cortex activity was negatively correlated with the relative value. These results suggest that immediate and delayed rewards are separately represented in the dorsal mPFC and compared in the ventral mPFC to guide decisions. The functional dissociation of posterior and anterior DmPFC in representing immediate and delayed reward is consistent with the general structural and functional architecture of the prefrontal cortex and may provide a neural basis for human's unique capacity to delayed gratification.


Assuntos
Comportamento de Escolha/fisiologia , Imageamento por Ressonância Magnética/métodos , Córtex Pré-Frontal/fisiologia , Tempo de Reação/fisiologia , Recompensa , Feminino , Humanos , Masculino , Estimulação Luminosa/métodos , Projetos Piloto , Adulto Jovem
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