Search results for " reactivity"

Intensive physical training reduces the airway response to methacholine in healthy subjects

2008

Effect of electron-withdrawing substituents on the electrophilicity of carbonyl carbons

2005

Indexación: Scopus The substituent effects on the carbonyl carbon atom for a series of twelve substituted phenyl acetates have been rationalized using a global electrophilicity index. This index is linearly correlated with the experimental reaction rate coefficients. We found that, in contrast to the proposed interpretation based on experimental 13C NMR chemical shifts and ground state destabilization calculations, the electrophilicity of carbonyl compounds increases due to the effect promoted by electron-withdrawing groups in these systems. https://www.sciencedirect.com/science/article/pii/S0040402004018046?via%3Dihub

Ionic liquids: “normal” solvents or nanostructured fluids?

2021

Ionic liquids (ILs) are a class of non-conventional solvents, which, for almost two decades, have continued to generate burgeoning interest in different fields of present-day chemical research with few similar precedents. Among the various aspects related to ILs, a topic worthy of in-depth analysis is their influence on organic reactivity and reaction rates. In light of this, the present short review aims to provide an overview of the literature from 2010 to the present day that addresses this issue. In particular, we herein present two main different viewpoints by which the solvent effect of ILs is explained: the first is mainly based on considering the bulk polarity of ILs and linear solv…

The Interaction of Person-Affect-Cognition-Execution (I-PACE) model for addictive behaviors: Update, generalization to addictive behaviors beyond int…

2019

We propose an updated version of the Interaction of Person-Affect-Cognition-Execution (I-PACE) model, which we argue to be valid for several types of addictive behaviors, such as gambling, gaming, buying-shopping, and compulsive sexual behavior disorders. Based on recent empirical findings and theoretical considerations, we argue that addictive behaviors develop as a consequence of the interactions between predisposing variables, affective and cognitive responses to specific stimuli, and executive functions, such as inhibitory control and decision-making. In the process of addictive behaviors, the associations between cue-reactivity/craving and diminished inhibitory control contribute to th…

Addiction Research Unit: Affective and cognitive mechanisms of specific Internet‐use disorders

2021

In the eleventh International Classification of Diseases (ICD-11) of the World Health Organization, gambling disorder and gaming disorder are included in the category 'disorders due to addictive behaviours', which can be specified further as occurring either predominantly offline or predominantly online. Other specific problematic behaviours may be considered for the category 'other specified disorders due to addictive behaviours'. The Research Unit FOR 2974, funded by the German Research Foundation (Deutsche Forschungsgemeinschaft, DFG), focuses on the most prominent online addictive behaviours: gaming, pornography use, buying-shopping and social-networks use. The main goal of the Research…

Adicción a la pornografía: interferencia atencional y gravedad del consumo

2019

Introducción: El aumento del uso de las Tecnologías de la Información y la Comunicación (TICS) e Internet en nuestra sociedad ha potenciado la aparición de nuevas formas de adicción. Una de las más relevantes por sus implicaciones sociosanitarias sería la adicción al cibersexo, y más en concreto, el visionado excesivo de pornografía online. Numerosos estudios apuntan que, en determinadas personas, el visionado de pornografía puede sobrevenir excesivo e incontrolado, generando graves problemas en las diferentes áreas de la vida. Por ello, es importante explorar aquellos factores que actúan como predisponentes o mantenedores de este problema. Se postula que uno de ellos podría ser la capacida…

Parental expectations and prosocial behavior of adolescents from low-income backgrounds. A cross-cultural comparison between three countries: Argenti…

2014

Parental expectations are influenced by cultural models, which in turn are subject to a great influence from historically fluctuating features of the socioeconomic background. Parental expectations seem to be linked to children’s social and emotional development in terms of empathy and prosocial behavior. The current study aims to (a) compare low-income adolescents’ perceptions of parental expectations of prosocial and antisocial behavior across three Latin countries (Argentina, Colombia, and Spain), (b) compare the empathy and prosocial behavior between the three countries, (c) compare the prosocial behavior between the three countries, and (d) study the effect of perceived parental expect…

Enhanced Surface Ligands Reactivity of Metal Clusters by Bulky Ligands for Controlling Optical and Chiral Properties.

2021

Surface ligands play critical roles in determining the surface properties of metal clusters. However, modulating the properties and controlling the surface structure of clusters through surface‐capping agent displacement remain a challenge. In this work, a silver cluster, [Ag 14 (SPh(CF 3 ) 2 ) 12 (PPh 3 ) 4 (DMF) 4 ] ( Ag 14 ‐DMF , where HSPh(CF 3 ) 2 is 3,5‐bis(trifluoromethyl)benzenethiol, PPh 3 is triphenylphosphine and DMF is N,N‐Dimethylformamide), with weakly coordinated DMF ligands on the surface silver sites, was synthesized by using a mixed ligands strategy (bulky thiolates, phosphines and small solvents). The as‐prepared Ag 14 ‐DMF is a racemic mixture of chiral molecules. Owing …

Dependence of the Lattice Parameter of Magnesium Oxide on Crystallite Size

1966

Lattice parameters were measured on MgO specimens prepared in air between 450° and 1200°C. The lattice parameter, a, decreases with increase in preparation temperature, Tp, and with increase in crystallite size. A hydroxide layer is present on the MgO particles. If MgO is prepared in vacuum, a increases as Tp increases and as crystallite size, D, increases. It is concluded that a dilatant volume stress is imposed by the hydroxide layer. It is also shown that the oxide surface reactivity toward water is linked to the deviation from perfect order ensuing from low preparation temperatures.

Avoidant coping style and verbal-cardiovascular response dissociation

1996

Abstract This study explored the relationship between an avoidant coping style and three responses during three experimental periods (i.e., speech preparation, speech delivery, and recovery). One response was cardiovascular reactivity, the two other responses were subjective in nature: self-reports of anxiety and self-estimations of blood pressure. Subjects were 20 male and 20 female students who scored either in the upper third (i.e., high-avoiders) or lower third (i.e., low-avoiders) on cognitive avoidance (Krohne, 1989). When compared to subjects scoring low on avoidance, those high on avoidance showed greater systolic blood pressure (SBP) reactivity and evidenced verbal-autonomic respon…