Molecular dynamics simulation of carbon nanotube growth under a tensile strain.

We performed molecular dynamics simulations of carbon nanotube (CNT) to elucidate the growth process in the floating catalyst chemical vapor deposition method (FCCVD). FCCVD has two features: a nanometer-sized cementite (Fe 3 C) particle whose melting point is depressed because of the larger surface-to-volume ratio and tensile strain between the growing CNT and the catalyst. The simulations, including these effects, demonstrated that the number of 6-membered rings of the (6,4) chiral CNT constantly increased at a speed of 1 mm / s at 1273 K , whereas those of the armchair and zigzag CNTs were stopped in the simulations and only reached half of the numbers for chiral CNT. Both the temperature and CNT chirality significantly affected CNT growth under tensile strain.

Suppression of Methanol and Formate Crossover through Sulfanilic-Functionalized Holey Graphene as Proton Exchange Membranes.

Proton exchange membranes with high proton conductivity and low crossover of fuel molecules are required to realize advanced fuel-cell technology. The selective transportation of protons, which occurs by blocking the transportation of fuel molecules across a proton exchange membrane, is crucial to suppress crossover while maintaining a high proton conductivity. In this study, a simple yet powerful method is proposed for optimizing the crossover-conductivity relationship by pasting sulfanilic-functionalized holey graphenes onto a Nafion membrane. The results show that the sulfanilic-functionalized holey graphenes supported by the membrane suppresses the crossover by 89% in methanol and 80% in formate compared with that in the self-assembled Nafion membrane; an ≈60% reduction is observed in the proton conductivity. This method exhibits the potential for application in advanced fuel cells that use methanol and formic acid as chemical fuels to achieve high energy efficiency.

Corrosion-Resistant and High-Entropic Non-Noble-Metal Electrodes for Oxygen Evolution in Acidic Media.

To realize a sustainable hydrogen economy, corrosion-resistant non-noble-metal catalysts are needed to replace noble-metal-based catalysts. The combination of passivation elements and catalytically active elements is crucial for simultaneously achieving high corrosion resistance and high catalytic activity. Herein, the self-selection/reconstruction characteristics of multi-element (nonary) alloys that can automatically redistribute suitable elements and rearrange surface structures under the target reaction conditions during the oxygen evolution reaction are investigated. The following synergetic effect (i.e., cocktail effect), among the elements Ti, Zr, Nb, and Mo, significantly contributes to passivation, whereas Cr, Co, Ni, Mn, and Fe enhance the catalytic activity. According to the practical water electrolysis experiments, the self-selected/reconstructed multi-element alloy demonstrates high performance under a similar condition with proton exchange membrane (PEM)-type water electrolysis without obvious degradation during stability tests. This verifies the resistance of the alloy to corrosion when used as an electrode under a practical PEM electrolysis condition.

Effectiveness of anger-focused emotional management training in reducing aggression among nurses.

AIM: The aim of this study was to conduct a 5-h training programme on anger-focused emotional management for nurses and verify its effectiveness. DESIGN: The study used a one-group pretest-posttest design. METHODS: Participants (N = 283) attended a programme comprising lectures and exercises. The Japanese version of the Buss-Perry Aggression Questionnaire was administered pre-, post- and 3-month posttraining. Regression analyses were used to assess the effects of the programme by gender. RESULTS: For the total aggression score, the difference between the pre- and posttraining scores was -2.827 points and remained at -1.602 points 3-month posttraining. Physical aggression scores decreased posttraining, but the scores increased after 3 months. There were statistically significant gender differences in hostility scores; pre-training scores were slightly higher for men than for women and lower for men after 3 months. Total and physical aggression scores were higher for men than for women. The training programme decreased aggression, and the effect persisted after 3 months.

The psychological distress and suicide-related ideation in hospital workers during the COVID-19 pandemic: Second results from repeated cross-sectional surveys.

The COVID-19 pandemic has been affecting the mental health of hospital workers. During the prolonged pandemic, hospital workers may experience much more severe psychological distress, leading to an increased risk of suicide. This study aimed to investigate changes in psychological effects on hospital workers over 12 months from the beginning of the pandemic and clarify factors associated with psychological distress and suicide-related ideation 1-year after the pandemic's beginning. These repeated, cross-sectional surveys collected demographic, mental health, and stress-related data from workers in 2 hospitals in Yokohama, Japan. The first survey, conducted in March-April 2020, contained the 12-item General Health Questionnaire (GHQ-12) assessing general distress and the Impact of Event Scale-Revised (IES-R) assessing event-related distress. In the second survey in March 2021, hospital workers at the same two hospitals were reassessed using the same questionnaire, and Item 9 of the Patient Health Questionnaire (PHQ-9) was added to assess their suicide-related ideation. The findings of the first and second surveys revealed that the average score of GHQ-12 (3.08 and 3.73, respectively), the IES-R total score (6.8 and 12.12, respectively), and the prevalence rates of severe general distress (35.0% and 44.0%, respectively) and severe event-related distress (7.0% and 17.1%, respectively) deteriorated. The second survey showed that 8.6% of the hospital workers were experiencing suicide-related ideation. Both the general and event-related distress were associated with suicide-related ideation. In these surveys, mental health outcomes among the hospital workers deteriorated over one year from the pandemic's beginning, and their severe psychological distress was the risk factor for the suicide-related ideation. Further studies are needed to compare the psychological effects on hospital workers during and after the prolonged pandemic and to explore appropriate measures to support hospital workers' mental health.

Viscoelasticity of Low-Molecular-Weight Polyelectrolytes.

Shear-thickening fluids that absorb the impact energy of high-velocity projectiles are of great interest for aerospace and body-armor applications. In such a frame, we investigate transient states of neat and aqueous polyelectrolytes (PE) having low molecular weights and containing poly([2-(methacryloyloxy)ethyl]trimethylammonium) as polycations and poly(acrylamide-co-acrylic acid) as polyanions. We compare results with those of bulk water. We employ nonequilibrium molecular dynamics to simulate oscillatory shear, mainly in the linear viscoelastic regime. We find that neat PE exhibits properties of a viscoelastic solid, whereas water and the aqueous mixture of PE conform to viscoelastic liquids with Maxwellian behavior at low angular frequencies. Terminal relaxation times are ∼0.499 and ∼1.385 ps for water and the aqueous mixture of PE, respectively. At high angular frequencies, storage moduli show anomalous behaviors that correspond to transitions between shear thinning and shear thickening in complex shear viscosities. The change in potential energy with the increase of the angular frequency is mainly driven by intramolecular interactions for neat PE, whereas short-range Coulomb interactions are the major contributions for water and the aqueous mixture of PE. Upon observation of the molecular configurations, only the local polyionic structure in the aqueous mixture of PE shows improvement when increasing the angular frequency, whereas the rest remains barely affected. Thus, the water structure in the aqueous mixture of PE allows the storage of energy elastically through the hydrogen-bond network at large angular frequencies, whereas the mechanical contribution of polyions weakens and fully vanishes at the beginning of shear thinning, explaining the superimposed data with data of bulk water. Our method and findings set the path for future molecular simulations in the nonlinear viscoelastic regime with more complex underlying molecular mechanisms.

Problematic Internet use and daily difficulties among adolescents with school refusal behaviors: An observational cross-sectional analytical study.

ABSTRACT: Problematic Internet use (PIU) is common and likely to coexist with mental health problems among adolescents with school refusal behavior. To date, no study has revealed to what extent PIU relates to the daily burden compared with other mental health problems. This study has examined the association between daily difficulties and PIU among adolescents with school refusal behaviors.This cross-sectional study involved all first-visit patients, regardless of diagnosis, aged 10 to 18 years at 2 child/adolescent psychiatric outpatient clinics in Yokohama City, Japan, from April 2016 to March 2018. The Questionnaire-Children with Difficulties (QCD) were obtained from parents. Simultaneously, the severity of PIU was evaluated using the Internet Addiction Test and depressive and anxiety symptoms were evaluated using the Patient Health Questionnaire-9 and General Anxiety Disorder-7 scale in the 2 weeks before the first-visit. From 684 first-visit patients, 227 with school refusal behaviors were enrolled in the study.PIU was observed in 40% of adolescents with school refusal behaviors. The QCD scores among patients with PIU were significantly lower than those in patients without PIU. Linear regression analysis revealed relationships between PIU and lower QCD scores throughout the day (except at night) and the total score of the day, after controlling for confounders such as depressive and anxiety symptoms.In conclusion, among adolescents with school refusal behaviors, PIU may affect their parent-assessed daily difficulties particularly experienced throughout the day.

Structural brain abnormalities in adolescent patients with anorexia nervosa at both the acute and weight-recovered phase.

Previous cross-sectional studies have reported that adolescent patients with anorexia nervosa (AN) showed global gray matter volume (GMV) reductions at the acute phase which were restored at the weight-recovered phase, compared with healthy controls (HC). However, few studies have investigated white matter volume (WMV) or cortical thickness in the context of AN, and results have been inconsistent. Voxel-based morphometry analyses for GM and WM, and cortical thickness analyses for GM were conducted in 31 adolescent patients with AN (vs. 18 HC) in the acute phase, and 16 patients with AN (vs. 13 HC) in the follow-up weight-recovered phase, over an approximately 1-year follow-up interval. At the acute phase, the AN patients showed significant reductions of GMVs and cortical thickness in widespread brain regions, compared with HC. Significant WMV reductions were identified in the bilateral superior longitudinal fascicle, superior thalamic radiation, corona radiata, and fornix, pons, and medulla in the patients. At the weight-recovered phase, the AN patients showed a significant GMV reduction in the left hippocampus, and a WMV reduction in the pons, compared with the HC. There was no difference in cortical thickness between two groups at the weight-recovered phase. In conclusion, the widespread volumetric reductions in GM and WM, and reduced cortical thickness observed in AN patients in the acute phase were not evident in the follow-up weight-recovered phase. The volume reductions observed in the hippocampus and pons in the weight-recovered phase could potentially reflect delayed neurogenesis or recovery from starvation in the AN patients.

One step fabrication of aligned carbon nanotubes using gas rectifier.

We report the one-step fabrication of aligned and high-quality carbon nanotubes (CNTs) using floating-catalyst chemical vapor deposition (FCCVD) with controlled fluidic properties assisted by a gas rectifier. The gas rectifier consists of one-dimensional straight channels for regulating the Reynolds number of the reaction gas. Our computational fluid dynamics simulation reveals that the narrow channels of the gas rectifier provide steady and accelerated laminar flow of the reaction gas. In addition, strong shear stress is induced near the side wall of the channels, resulting in the spontaneous formation of macroscopic CNT bundles aligned along the direction of the gas flow. After a wet-process using chlorosulfonic acid, the inter-tube voids inherently observed in as-grown CNT bundles are reduced from 16 to 0.3%. The resulting CNT fiber exhibits a tensile strength of 2.1 ± 0.1 N tex-1 with a Young's modulus of 39 ± 4 N tex-1 and an elongation of 6.3 ± 0.6%. FCCVD coupled with the strong shear stress of the reaction gas is an important pre-processing route for the fabrication of high-performance CNT fibers.

Association between suicidal behaviors and auditory and visual hallucinations in Japanese adolescent psychiatric outpatients at first visit: a cross-sectional study.

BACKGROUND: Suicide remains one of the leading causes of death among adolescents. Although recent studies have suggested a strong association between auditory hallucinations and suicidal behaviors, little is known regarding the association between suicidal behaviors and visual hallucinations, which are also common among adolescent psychiatric patients. METHOD: A cross-sectional study of all first-time patients aged 10-15 years was conducted at three child and adolescent psychiatric outpatient facilities in Kanagawa Prefecture, Japan, from April 2015 to March 2018. Self-reported questionnaires were administered to evaluate auditory and visual hallucinations, suicide planning, and suicide attempts within the two weeks prior to the first visit. Our logistic regression model included three covariates (sex, age, and presence of major depressive episode) for adjustments. Among the 1285 respondents, 37 who had moderate or severe intellectual disability were excluded, leaving 1248 for analysis. RESULTS: Among the 1069 patients who completed questionnaire items on hallucinations, 230 (21.5%) experienced auditory or visual hallucinations. After controlling for all confounders, visual hallucinations, but not auditory hallucinations, were significantly associated with increased odds of suicide planning (odds ratio [OR] 2.5, 95% confidence interval [CI] 1.5-4.1). In contrast, auditory hallucinations, but not visual hallucinations, were significantly associated with increased odds of suicide attempts (OR 2.8, 95% CI 1.3-6.1). No interaction effects were observed between suicidal behaviors and auditory or visual hallucinations. CONCLUSIONS: Clinicians should consider the prevalence of both auditory and visual hallucinations among young adolescent patients, with emphasis on auditory hallucinations, given their association with suicide attempts.

Decision aid development and its acceptability among adults with attention-deficit/hyperactivity disorders regarding treatment discontinuation after remission.

Aim: Current clinical guidelines for attention-deficit/hyperactivity disorder (ADHD) put shared decision making (SDM) at the center of care. However, there remain challenges in SDM in ADHD management, particularly regarding the decision to continue or discontinue medication after ADHD remission in adult patients. We aimed to develop a decision aid (DA) for adult patients with ADHD regarding the continuation or discontinuation of their ongoing ADHD medications after they have attained remission. Method: We systematically developed a DA according to the International Patient Decision Aid Standard (IPDAS). First, we created a DA prototype using the results of our previous systematic review and meta-analysis that identified the consequences of continuing and discontinuing ADHD medications. Second, we administered a mixed-method questionnaire (alpha acceptability testing) to adult patients with ADHD and healthcare providers to improve the DA prototype and develop it into a final version that is acceptable for clinical settings. Results: Our DA consisted of ADHD description, the option to continue or discontinue ADHD medications, the advantages and disadvantages of the consequences, as well as value clarification exercises for each option. Patients (n = 20) reported that the DA had acceptable language (85%), adequate information (75%), and a well-balanced presentation (53%). Healthcare providers (n = 19) provided favorable feedback. The final DA met all six IPDAS requisite criteria. Conclusions: Our results could facilitate the SDM process between patients and healthcare providers on the continuation or discontinuation of ADHD medication following remission. Further studies should verify the effects of using the DA during the SDM process among patients across the age spectrum with ADHD and healthcare providers.

Microstructure of the fluid particles around the rigid body at the shear-thickening state toward understanding of the fluid mechanics.

We studied the shear-thickening behavior of systems containing rigid spherical bodies immersed in smaller particles using non-equilibrium molecular dynamics simulations. We generated shear-thickening states through particle mass modulation of the systems. From the microstructures, i.e., two-dimensional pair distribution functions, we found anisotropic structures resulting from shear thickening, that are explained by the difference between the velocities of rigid bodies and fluid particles. The increasing viscosity in our system originated from collisions between fluid particles and rigid bodies. The lubrication forces defined in macroscale physics are then briefly discussed.

Neat and Aqueous Polyelectrolytes under a Steady-Shear Flow.

Materials enabling impact-energy absorption of high-velocity projectiles are of great interest for applications like aerospace. In such a frame, shear thickening fluids were found very useful. Here, we investigated nanorheological properties of neat and aqueous polyelectrolytes of low molecular weights containing poly([2-(methacryloyloxy) ethyl] trimethyl ammonium) as polycations and poly(acrylamide-co-acrylic acid) as polyanions. Results were compared with pure water. We employed nonequilibrium molecular dynamics with the SLLOD algorithm to compute the viscosity at various shear rates. Systems containing polyelectrolytes exhibit shear thickening. The analysis of molecular configurations revealed a strong disruption of the ionic structure and more clusters with smaller sizes on increasing the shear rate. Potential energies showed that shear thickening originates from an increase in intramolecular and van der Waals interactions resulting from the increasing difficultly of polyelectrolyte-based systems to relax at high shear rates. Our method and findings underscore the importance of accounting for the molecular scale in the design of materials absorbing the impact energy efficiently.

Catalytic activity of graphene-covered non-noble metals governed by proton penetration in electrochemical hydrogen evolution reaction.

Graphene-covering is a promising approach for achieving an acid-stable, non-noble-metal-catalysed hydrogen evolution reaction (HER). Optimization of the number of graphene-covering layers and the density of defects generated by chemical doping is crucial for achieving a balance between corrosion resistance and catalytic activity. Here, we investigate the influence of charge transfer and proton penetration through the graphene layers on the HER mechanisms of the non-noble metals Ni and Cu in an acidic electrolyte. We find that increasing the number of graphene-covering layers significantly alters the HER performances of Ni and Cu. The proton penetration explored through electrochemical experiments and simulations reveals that the HER activity of the graphene-covered catalysts is governed by the degree of proton penetration, as determined by the number of graphene-covering layers.

The psychological effects of COVID-19 on hospital workers at the beginning of the outbreak with a large disease cluster on the Diamond Princess cruise ship.

The aim of the present study was to investigate the psychological effects of the COVID-19 outbreak and associated factors on hospital workers at the beginning of the outbreak with a large disease cluster on the Diamond Princess cruise ship. This cross-sectional, survey-based study collected demographic data, mental health measurements, and stress-related questionnaires from workers in 2 hospitals in Yokohama, Japan, from March 23, 2020, to April 6, 2020. The prevalence rates of general psychological distress and event-related distress were assessed using the 12-item General Health Questionnaire (GHQ-12) and the 22-item Impact of Event Scale-Revised (IES-R), respectively. Exploratory factor analysis was conducted on the 26-item stress-related questionnaires. Multivariable logistic regression analysis was performed to identify factors associated with mental health outcomes for workers both at high- and low-risk for infection of COVID-19. A questionnaire was distributed to 4133 hospital workers, and 2697 (65.3%) valid questionnaires were used for analyses. Overall, 536 (20.0%) were high-risk workers, 944 (35.0%) of all hospital workers showed general distress, and 189 (7.0%) demonstrated event-related distress. Multivariable logistic regression analyses revealed that 'Feeling of being isolated and discriminated' was associated with both the general and event-related distress for both the high- and low-risk workers. In this survey, not only high-risk workers but also low-risk workers in the hospitals admitting COVID-19 patients reported experiencing psychological distress at the beginning of the outbreak.

Prescription patterns in patients with schizophrenia in Japan: First-quality indicator data from the survey of "Effectiveness of Guidelines for Dissemination and Education in psychiatric treatment (EGUIDE)" project.

BACKGROUND: Guideline for Pharmacological Therapy for Schizophrenia was published by the Japanese Society of Neuropsychopharmacology in 2015. "Effectiveness of Guidelines for Dissemination and Education in psychiatric treatment (EGUIDE)" project aimed to standardize medical practice using quality indicators (QIs) as indices to evaluate the quality of medical practice. In this study, we have reported the quality indicator values of prescription before the beginning of the guideline lectures in the EGUIDE project to ascertain the baseline status of treating patients with schizophrenia. METHODS: A cross-sectional, retrospective case record survey was conducted, involving 1164 patients with schizophrenia at the time of discharge. We checked all types and dosage of psychotropic drugs. RESULTS: Forty-three percent of patients had antipsychotic polypharmacy, and substantial concomitant medication was observed (antidepressants; 8%, mood stabilizers: 37%, anxiolytics or hypnotics: 68%). CONCLUSIONS: In the results obtained in this study, we plant to report changes in the effectiveness of education in the EGUIDE project near the future.

Understanding the Detection Mechanisms and Ability of Molecular Hydrogen on Three-Dimensional Bicontinuous Nanoporous Reduced Graphene Oxide.

Environmental safety has become increasingly important with respect to hydrogen use in society. Monitoring techniques for explosive gaseous hydrogen are essential to ensure safety in sustainable hydrogen utilization. Here, we reveal molecular hydrogen detection mechanisms with monolithic three-dimensional nanoporous reduced graphene oxide under gaseous hydrogen flow and at room temperature. Nanoporous reduced graphene oxide significantly increased molecular hydrogen physisorption without the need to employ catalytic metals or heating. This can be explained by the significantly increased surface area in comparison to two-dimensional graphene sheets and conventional reduced graphene oxide flakes. Using this large surface area, molecular hydrogen adsorption behaviors were accurately observed. In particular, we found that the electrical resistance firstly decreased and then gradually increased with higher gaseous hydrogen concentrations. The resistance decrease was due to charge transfer from the molecular hydrogen to the reduced graphene oxide at adsorbed molecular hydrogen concentrations lower than 2.8 ppm; conversely, the resistance increase was a result of Coulomb scattering effects at adsorbed molecular hydrogen concentrations exceeding 5.0 ppm, as supported by density functional theory. These findings not only provide the detailed adsorption mechanisms of molecular hydrogen, but also advance the development of catalyst-free non-heated physisorption-type molecular detection devices.