Heavy Anionic Complex Creates a Unique Water Structure at a Soft Charged Interface

Ion hydration and interfacial water play crucial roles in numerous phenomena ranging from biological to industrial systems. Although biologically relevant (and mostly smaller) ions have been studied extensively in this context, very little experimental data exist about molecular scale behavior of heavy ions and their complexes at interfaces, especially under technologically significant conditions. It has recently been shown that PtCl62- complexes adsorb at positively charged interfaces in a two-step process that cannot fit into well-known empirical trends, such as Hofmeister series. Here, a combined vibrational sum frequency generation and molecular dynamics study reveals that a unique interfacial water structure is connected to this peculiar adsorption behavior. A novel sub-ensemble analysis of MD simulation results show that after adsorption, PtCl62- complexes partially retain their first and second hydration spheres, and it is possible to identify three different types of water molecules around them based on their orientational structures and hydrogen bonding strengths. These results have important implications for relating interfacial water structure and hydration enthalpy to the general understanding of specific ion effects. This in turn influences interpretation of heavy metal ion distribution across and reactivity within, liquid interfaces

Exploiting Emotion-Semantic Correlations for Empathetic Response Generation

Empathetic response generation aims to generate empathetic responses by understanding the speaker's emotional feelings from the language of dialogue. Recent methods capture emotional words in the language of communicators and construct them as static vectors to perceive nuanced emotions. However, linguistic research has shown that emotional words in language are dynamic and have correlations with other grammar semantic roles, i.e., words with semantic meanings, in grammar. Previous methods overlook these two characteristics, which easily lead to misunderstandings of emotions and neglect of key semantics. To address this issue, we propose a dynamical Emotion-Semantic Correlation Model (ESCM) for empathetic dialogue generation tasks. ESCM constructs dynamic emotion-semantic vectors through the interaction of context and emotions. We introduce dependency trees to reflect the correlations between emotions and semantics. Based on dynamic emotion-semantic vectors and dependency trees, we propose a dynamic correlation graph convolutional network to guide the model in learning context meanings in dialogue and generating empathetic responses. Experimental results on the EMPATHETIC-DIALOGUES dataset show that ESCM understands semantics and emotions more accurately and expresses fluent and informative empathetic responses. Our analysis results also indicate that the correlations between emotions and semantics are frequently used in dialogues, which is of great significance for empathetic perception and expression.Comment: 12 pages, 3 figures, Findings of EMNLP 202

The prevalence of childhood sexual experiences and intimate partner violence among transgender women in China: Risk factors for lifetime suicidal ideation

ObjectiveSeveral studies highlighted childhood sexual experiences (CSEs) and intimate partner violence (IPV) as risk factors that affected lifetime suicidal ideation. TW had higher rates of CSEs and IPV than cisgender people. The aim of this study was to comprehensively assess the prevalence of CSEs and IPV among TW and their association with lifetime suicidal ideation.MethodsA cross-sectional survey was conducted among 247 TW in Shenyang and Kunming, China, from April to September 2018. CSEs, IPV, and lifetime suicidal ideation were assessed. Logistic regression models were used to examine the association between self-reported CSEs under 18 years of age, IPV in adulthood, and lifetime suicidal ideation.ResultsIn the study, 14.2% (35/247) of the sample participants reported CSEs under 18 years of age; 44.9% (111/247) reported experiencing IPV in adulthood, including 18.6% (44/247) of physical IPV, 27.1% (67/247) of trans-specific identity IPV, 31.6% (78/247) of verbal IPV, and 19.4% (48/247) of sexual IPV; and 26.3% (65/247) had thought about attempting suicide at least one time. CSEs and any form of IPV were significantly associated with suicidal ideation in this sample population. A final stepwise multivariate logistic regression model found that both physical and verbal IPVs were significantly associated with suicidal ideation when controlling for other factors (ORm1 = 2.58, 95% confidence interval (CI) = 1.163–5.724; ORm2 = 2.72, 95% CI = 1.334–5.547).ConclusionsThe findings highlight the effects of CSEs and IPV among TW and suggest the need for research on suicide in the future. Suicide prevention efforts for this invisible and vulnerable population should focus on those with physical and verbal IPV

Comparative Study on Cooling Performance of Two PCM-Assisted EAHEs and Traditional EAHE

It is well known that the sensible heat storage/release process is accompanied by significant changes in the temperature of storage medium. However, this feature of the sensible heat storage medium, namely soil, is unfavorable to fully exert the potential of traditional EAHE. To overcome this deficiency, two phase change material(PCM)-assisted EAHEs are proposed, one is the hollow cylindrical PCM-assisted EAHE and the other is the cylindrical PCM-assisted EAHE. In order to investigate the actual cooling performance of these novel systems in summer, a three-dimensional numerical model based on the effective heat capacity method is established by FLUENT 16.0. And the calculation results of this model have been validated in previous studies. Then, under the condition of equal air volume, a comparative study between these PCM-assisted EAHEs and the Traditional EAHE has been conducted to evaluate their cooling performance under the high-temperature meteorological conditions in Chongqing (China). The results indicate that the cooling performance of these PCM-assisted EAHE systems has been significantly improved when compared with the Traditional EAHE. And in terms of the improvement on cooling performance, the cylindrical PCM-assisted EAHE performs better than the hollow cylindrical PCM-assisted EAHE. More specifically, the total cooling capacities contributed by the hollow cylindrical PCM-assisted EAHE and cylindrical PCM-assisted EAHE have been respectively improved by 17.68% and 20.05% during the 20-days investigated period. The excellent performance of cylindrical PCM-assisted EAHE ultimately limits the temperature fluctuation of fresh air introduced by this novel system to less than 1 °C

NETWORK ANALYSIS ALGORITHMS AND APPLICATIONS TO UNDERSTAND AQUEOUS SOLUTIONS AND THEIR INTERFACES

Computational simulations have been widely used in a variety of disciplines including physics, chemistry, materials science and biology. Intermolecular Network Theory (INT) provides a generalized multiscale analysis framework that can be utilized to investigate the associated structural and dynamic properties of the intermolecular interactions of chemical systems across different length scales and time scales. New analysis techniques within INT are described and then applied to understand the structures and dynamics of water hydrogen bond network in liquid water, its aqueous solutions and interfaces.The transitions between patterns of hydrogen bonding are shown to reveal underlying molecular motions, as demonstrated for water reorientation. This work describes the detailed network analyses of water hydrogen bond dynamics about non-polar alkanes and under hydrophobic confinement. In the former, no structure enhancement is observed for water in the first hydration shell of alkanes; while a significant dynamic retardant effect is observed in terms of the water reorientation motion. In the latter, both the structural organization of the hydrogen bond network and its dynamics are massively perturbed. Using INT in combination with second-order Møller-Plesset perturbation theory, it reveals that the effect of hydrophobic confinement is predominantly (~75%) due to geometric restriction, however the competition of intermolecular forces, specifically the weakly attractive hydrophobic interaction with the confining surface, has a significant (~25%) impact. In addition, the interfacial structures and dynamics of water at the bi-phasic water/vapor and water/organic interfaces have also been investigated using INT, wherein it is demonstrated that capillary wave fronts at the interface are both structurally and dynamically heterogeneous. This interfacial heterogeneity has been correlated with the surface-sensitive vibrational sum frequency generation experiments at a soft charged aqueous interface

Towards a unified description of the hydrogen bond network of liquid water: A dynamics based approach

The definition of a hydrogen bond (H-bond) is intimately related to the topological and dynamic properties of the hydrogen bond network within liquid water. The development of a universal H-bond definition for water is an active area of research as it would remove many ambiguities in the network properties that derive from the fixed definition employed to assign whether a water dimer is hydrogen bonded. This work investigates the impact that an electronic-structure based definition, an energetic, and a geometric definition of the H-bond has upon both topological and dynamic network behavior of simulated water. In each definition, the use of a cutoff (either geometric or energetic) to assign the presence of a H-bond leads to the formation of transiently bonded or broken dimers, which have been quantified within the simulation data. The relative concentration of transient species, and their duration, results in two of the three definitions sharing similarities in either topological or dynamic features (H-bond distribution, H-bond lifetime, etc.), however no two definitions exhibit similar behavior for both classes of network properties. In fact, two networks with similar local network topology (as indicated by similar average H-bonds) can have dramatically different global network topology (as indicated by the defect state distributions) and altered H-bond lifetimes. A dynamics based correction scheme is then used to remove artificially transient H-bonds and to repair artificially broken bonds within the network such that the corrected network exhibits the same structural and dynamic properties for two H-bond definitions (the properties of the third definition being significantly improved). The algorithm described represents a significant step forward in the development of a unified hydrogen bond network whose properties are independent of the original hydrogen bond definition that is employed. (C) 2014 AIP Publishing LLC