Insight into the transport of ions from salts of moderated solubility through nanochannels: negative incremental resistance assisted by geometry.

In this study, the transport of salt with moderate solubility through bioinspired solid-state nanochannels was comprehensively investigated. For this purpose, bullet-shaped channels were fabricated and exposed to KClO4, a monovalent salt with moderate solubility. These channels displayed the typical rectifying behavior characteristic of asymmetrical channels but with one remarkable difference, the iontronic output exhibited a negative incremental resistance phenomenon of high gating efficiency when the transmembrane voltage in the open state was increased enough, giving rise to an inactivated state characterized by a low and stable ion current. The behavior is attributed to salt precipitation inside the channel and remarkably, it is not observed in other geometries such as cylindrical or cigar-shaped channels. Considering the central role of the surface in precipitation formation, the influence of several parameters such as electrolyte concentration, pH, and channel size was studied. Under optimized conditions, this system can alternate among three different conductance states (closed, open, and inactivated) and exhibits gating ratios higher than 20. Beyond its potential application in fields related to electronics or sensing, this study provides valuable insight into the fundamental principles behind ion rectifying behavior in solid-state channels and highlights the implications of surface phenomena at the nanoscale.

Manipulating Ion Transport Regimes in Nanomembranes via a "Pore-in-Pore" Approach Enabled by the Synergy of Metal-Organic Frameworks and Solid-State Nanochannels.

Solid-state nanochannels (SSNs) have emerged as promising platforms for controlling ionic transport at the nanoscale. SSNs are highly versatile, and this feature can be enhanced through their combination with porous materials such as Metal-Organic Frameworks (MOF). By selection of specific building blocks and experimental conditions, different MOF architectures can be obtained, and this can influence the ionic transport properties through the nanochannel. Herein, we study the effects of confined synthesis of Zr-based UiO-66 MOF on the ion transport properties of single bullet-shaped poly(ethylene terephthalate) (PET) nanochannels. We have found that emerging textural properties from the MOF phase play a determinant role in controlling ionic transport through the nanochannel. We demonstrate that a transition from ion current saturation regimes to diode-like regimes can be obtained by employing different synthetic approaches, namely, counterdiffusion synthesis, where MOF precursors are kept separate and forced to diffuse through the nanochannel, and one-pot synthesis, where both precursors are placed at both ends of the channel. Also, by considering the dependence of the charge state of the UiO-66 MOF on the protonation degree, pH changes offered a mechanism to tune the iontronic output (and selectivity) among different regimes, including anion-driven rectification, cation-driven rectification, ion current saturation, and ohmic behavior. Furthermore, Poisson-Nernst-Planck (PNP) simulations were employed to rationalize the different iontronic outputs observed experimentally for membranes modified by different methods. Our results demonstrate a straightforward tool to synthesize MOF-based SSN membranes with tunable ion transport regimes.

Does parental use of harsh discipline and punishment in response to ambiguous child situations vary by child physical abuse risk?

BACKGROUND/OBJECTIVES: The present study investigated the extent to which fathers and mothers at high-risk and low-risk for child physical abuse (CPA) differed in their use of harsh discipline and punishment when presented ambiguous child situations (situations where differences in positive and negative valences are close to zero). PARTICIPANTS/METHODS: High-risk for CPA parents (N = 74: fathers, n = 41; mothers, n = 33) and low-risk parents (N = 178: fathers, n = 91; mothers, n = 87) were asked to indicate their likelihood of using harsh verbal discipline (HVD), harsh physical discipline (HPD), and punishment (i.e., retributive harm separate from HVD and HPD) after viewing each of eighteen ambiguous child situations. RESULTS: As expected, high-risk, compared to low-risk, for CPA parents were significantly (ps < 0.001) more likely to use HVD (d = 0.546), HPD (d = 0.595), and punishment (d = 0.564). Overall, fathers, relative to mothers, were significantly more likely to use HVD (d = 0.261) and HPD (d = 0.238). For punishment, however, there was no significant parental role (father, mother) difference (d = 0.136). CONCLUSIONS: Since in everyday living situations many child behaviors are ambiguous, the findings that parents, especially high-risk for CPA parents, use harsh discipline and punishment when encountering ambiguous child situations suggest that non-contingent harsh child-related parental behaviors may be frequent in the lives of some children. The findings that parents may use non-contingent discipline and punishment suggest the need to explore whether, when these parenting behaviors occur, they increase the likelihood of negative child outcomes.

Electrochemically addressed FET-like nanofluidic channels with dynamic ion-transport regimes.

Nanofluidic channels in which the ionic transport can be modulated by the application of an external voltage to the nanochannel walls have been described as nanofluidic field effect transistors (nFETs) because of their analogy with electrolyte-gated field effect transistors. The creation of nFETs is attracting increasing attention due to the possibility of controlling ion transport by using an external voltage as a non-invasive stimulus. In this work, we show that it is possible to extend the actuation range of nFETs by using the supporting electrolyte as a "chemical effector". For this aim, a gold-coated poly(ethylene terephthalate) (PET) membrane was modified with electroactive poly-o-aminophenol. By exploiting the interaction between the electroactive poly-o-aminophenol and the ions in the electrolyte solution, the magnitude and surface charge of the nanochannels were fine-tuned. In this way, by setting the electrolyte nature it has been possible to set different ion transport regimes, i.e.: cation-selective or anion-selective ion transport, whereas the rectification efficiency of the ionic transport was controlled by the gate voltage applied to the electroactive polymer layer. Remarkably, under both regimes, the platform displays a reversible and rapid response. We believe that this strategy to preset the actuation range of nFETs by using the supporting electrolyte as a chemical effector can be extended to other devices, thus offering new opportunities for the development of stimulus-responsive solid-state nanochannels.

Switchable Ion Current Saturation Regimes Enabled via Heterostructured Nanofluidic Devices Based on Metal-Organic Frameworks.

The use of track-etched membranes allows further fine-tuning of transport regimes and thus enables their use in (bio)sensing and energy-harvesting applications, among others. Recently, metal-organic frameworks (MOFs) have been combined with such membranes to further increase their potential. Herein, the creation of a single track-etched nanochannel modified with the UiO-66 MOF is proposed. By the interfacial growth method, UiO-66-confined synthesis fills the nanochannel completely and smoothly, yet its constructional porosity renders a heterostructure along the axial coordinate of the channel. The MOF heterostructure confers notorious changes in the transport regime of the nanofluidic device. In particular, the tortuosity provided by the micro- and mesostructure of UiO-66 added to its charged state leads to iontronic outputs characterized by an asymmetric ion current saturation for transmembrane voltages exceeding 0.3 V. Remarkably, this behavior can be easily and reversibly modulated by changing the pH of the media and it can also be maintained for a wide range of KCl concentrations. In addition, it is found that the modified-nanochannel functionality cannot be explained by considering just the intrinsic microporosity of UiO-66, but rather the constructional porosity that arises during the MOF growth process plays a central and dominant role.

Exploring Positive Classical Conditioning Procedure Effects on Evaluations of Children, Thoughts About Children, and Behaviors Toward Children: Two Experiments.

Exposing parents to a positive classical conditioning (+CC) procedure can (a) prompt positive evaluations of children, (b) alter judgments made about children from their behavior, and (c) reduce harsh behaviors enacted toward children. Two studies explored possible limits of these effects. Results from Study 1 showed that only some +CC effects evinced in prior research emerged when the positive trait words used as the unconditioned stimuli in prior research were replaced with positive emojis. Results from Study 2 showed with positive trait word stimuli that a backward +CC procedure produced many of the same effects produced by the forward +CC procedure. These results collectively support the idea that +CC procedures may simultaneously prompt several different kinds of learning. From a practical perspective, consideration of these various kinds of learning is important to an understanding of when the use of the +CC procedure might reduce child abuse risk.

Child-related attributions of hostile intent and harsh discipline: Moderating effects of anger.

Two studies tested whether attributions of hostile intent (AHI) and anger for ambiguous child behaviors uniquely predict parents' harsh verbal discipline (HVD) and harsh physical discipline (HPD) or whether AHI only predicts harsh discipline when AHI occurs in conjunction with anger, as suggested by the Integrated Cognitive Model of general aggression (Wilkowski & Robinson, 2010, J. Pers., 78, 9-38). Replicating previous studies, the expected positive bivariate relationships between AHI, anger, HVD, and HPD were found in Study 1 (N = 493). However, when AHI, anger, and the AHI by anger interaction were considered simultaneously, patterns of prediction varied by discipline type. For HVD, high levels of AHI, high levels of anger, and the AHI by anger interaction (at high levels of AHI and anger) each were significant predictors. For HPD, low levels of AHI, high levels of anger, and the AHI by anger interaction (at high levels of AHI and anger) were significant predictors, suggesting a possible suppressor effect for AHI. These results were replicated in Study 2 ( N = 503). Thus, there was support for the contention that AHI only predicts harsh discipline when AHI occurs in conjunction with anger with respect to HPD but this was not the case for HVD. Since AHI suppressor effects were observed for HPD in two large sample studies, variables that may account for the AHI suppressor effects and the need for testing more complex interactive predictive models of harsh parenting behaviors are discussed.

Thinking About a Past Group Inclusion Experience or a Past Group Exclusion Experience Affects Memory Task Performance.

An experiment examined the impact of thinking about autobiographical group-related events (i.e., a past group inclusion experience or a past group exclusion experience) on recognition memory. After encountering the experimental manipulation, participants studied a list of words. Participants later engaged in two subsequent recognition tests: a group recognition test with a bogus confederate and a surprise individual recognition test. The memory measures were derived from signal detection theory and included hit rates, false alarm rates, and a memory discrimination index. Results showed that exposure to false information produced decreased hit rates, increased false alarms, and lowered discrimination values. Group-related thinking generally impaired recognition memory. These results are discussed in the context of prior research and in the context of theories of false memory.

Heart Rate and Heart Rate Variability in Parents at Risk for Child Physical Abuse.

The present study examined heart rate and heart rate variability (i.e., respiratory sinus arrhythmia [RSA]) in a sample of 48 general population parents (41.7% fathers), who were either at high risk (n = 24) or low risk (n = 24) for child physical abuse. During baseline assessments of heart rate and RSA, parents sat quietly for 3 min. Afterward, parents were presented with a series of anagrams (either easy or difficult) and were instructed to solve as many anagrams as possible in 3 min. As expected, high-risk (compared with low-risk) parents evinced significantly higher resting heart rate and significantly lower resting RSA. During the anagram task, high-risk parents did not evince significant changes in heart rate or RSA relative to baseline levels. In contrast, low-risk parents evinced significant increases in heart rate and significant decreases in RSA during the anagram task. Contrary to expectations, the anagram task difficulty did not moderate the study findings. Collectively, this pattern of results is consistent with the notion that high-risk parents have chronically higher levels of physiological arousal relative to low-risk parents and exhibit less physiological flexibility in response to environmental demands. High-risk parents may benefit from interventions that include components that reduce physiological arousal and increase the capacity to regulate arousal effectively.

Social influence and mental routes to the production of authentic false memories and inauthentic false memories.

Two studies assessed the extent to which people incorporated false facts provided by bogus others into their own recognition memory reports, and how these false memory reports were affected by: (a) truth of the information in others' summaries supporting the false facts, (b) motivation to process stories and summaries, (c) source credibility, and (d) ease of remembering original facts. False memory report frequency increased when false facts in a summary were supported by true information and varied inversely with the ease with which original facts could be remembered. Results from a measure probing participants' memory perceptions suggest that some false memories are authentic: People sometimes lack awareness of both the incorporation of false facts into their memory reports and where the false facts came from. However, many false memories are inauthentic: Despite reporting a false memory, people sometimes retain knowledge of the original stimulus and/or the origin of false facts.

Extreme rituals in a BDSM context: the physiological and psychological effects of the 'Dance of Souls'.

Participation in extreme rituals (e.g., fire-walking, body-piercing) has been documented throughout history. Motivations for such physically intense activities include religious devotion, sensation-seeking and social bonding. The present study aims to explore an extreme ritual within the context of bondage/discipline, dominance/submission and sadism/masochism (BDSM): the 'Dance of Souls', a 160-person ritual involving temporary piercings with weights or hooks attached and dancing to music provided by drummers. Through hormonal assays, behavioural observations and questionnaires administered before, during and after the Dance, we examine the physiological and psychological effects of the Dance, and the themes of spirituality, connectedness, transformation, release and community reported by dancers. From before to during the Dance, participants showed increases in physiological stress (measured by the hormone cortisol), self-reported sexual arousal, self-other overlap and decreases in psychological stress and negative affect. Results suggest that this group of BDSM practitioners engage in the Dance for a variety of reasons, including experiencing spirituality, deepening interpersonal connections, reducing stress and achieving altered states of consciousness.

Borderline personality features and emotion regulation deficits are associated with child physical abuse potential.

The present study extends prior research examining the association between borderline personality disorder (BPD) features and child physical abuse (CPA) risk. We hypothesized that: (1) high CPA risk parents (compared to low CPA risk parents) would more often report clinically elevated levels of BPD features; (2) high CPA risk parents with elevated BPD features would represent a particularly high-risk subgroup; and (3) the association between elevated BPD features and CPA risk would be partially explained by emotion regulation difficulties. General population parents (N=106; 41.5% fathers) completed self-report measures of BPD features, CPA risk, and emotion regulation difficulties. Results support the prediction that BPD features are more prevalent among high (compared to low) CPA risk parents. Among the parents classified as high CPA risk (n=45), one out of three (33.3%) had elevated BPD features. In contrast, none of the 61 low CPA risk parents reported elevated BPD symptoms. Moreover, 100% of the parents with elevated BPD features (n=15) were classified as high-risk for CPA. As expected, high CPA risk parents with elevated BPD features (compared to high CPA risk parents with low BPD features) obtained significantly higher scores on several Child Abuse Potential Inventory scales, including the overall abuse scale (d=1.03). As predicted, emotion regulation difficulties partially explained the association between BPD features and CPA risk. Findings from the present study suggest that a subset of high CPA risk parents in the general population possess clinically significant levels of BPD symptoms and these parents represent an especially high-risk subgroup. Interventions designed to address BPD symptoms, including emotion regulation difficulties, appear to be warranted in these cases.