Specific effects of cumulative childhood trauma on suicidality among youths.

BACKGROUND: Suicidality was very high among individuals who suffered from childhood trauma. The distribution of cumulative childhood trauma among youths remains unclear, as well as the specific effects of cumulative childhood trauma on suicidality. This study attempted to explore the distribution of cumulative childhood trauma and examine the specific effects of cumulative childhood trauma on suicidality. METHODS: A cross-sectional design was employed in this study, with 117,769 college students recruited from 63 universities in Jilin Province, China. All variables were measured by corresponding self-report questionnaires. The Venn diagram was used to represent the distribution of single and cumulative childhood trauma. ANOVA and chi-square tests were conducted to identify the high-risk suicide groups. Multiple linear regression analysis was performed to examine risk factors for suicidality for overlapping subtypes. RESULTS: 27,671 (23.5%) participants reported suffering from childhood trauma, of which 49.5% were male (Mage = 19.59, SD = 1.76). The "physical neglect" group accounted for the largest proportion (31.5%). Suicidality was the highest in the "overlap of childhood neglect, emotional abuse, and physical abuse" group (2.0%). Depression, obsessive-compulsive disorder, and post-traumatic stress disorder were common risk factors for suicidality. LIMITATIONS: This study was limited by cross-sectional studies and self-report bias. CONCLUSIONS: The childhood trauma subtype group with the largest proportion was not necessarily the highest suicidality. Both the largest group and the highest-risk suicide group require special attention to their respective risk factors.

Linear and curvilinear association of pain tolerance and social anxiety symptoms among youth with different subgroups of childhood trauma.

BACKGROUND: Social anxiety is a common symptom that occurs after exposure to childhood trauma (CT), and pain tolerance is a protective factor against social anxiety in generic populations with CT. However, few studies have investigated whether and how this association varies across different CT subgroups. Thus, this study aimed to investigate (1) the effects of pain tolerance on social anxiety symptoms among youth with different subgroups of CT; (2) the nonlinear relationship between pain tolerance and social anxiety symptoms among different CT categories. METHODS: In this study, 15,682 college or university students with experiences of CT were identified in a large sample and divided into five CT subgroups. Linear and quadratic regression models were conducted to explore the association between pain tolerance and social anxiety symptoms among youth with different CT subgroups. RESULTS: The results of model revealed a linear relationship between pain tolerance and social anxiety symptoms among youth with most CT subgroups. Notably, an inverted U-shaped curve was found between pain tolerance and social anxiety symptoms in youth with emotional abuse. Social anxiety symptoms increased gradually with pain tolerance scores between 0 and 16, and then sharply decreased when scores reached above 16. LIMITATIONS: Limited by self-report measurements, the results of this study focused only on perceived pain tolerance and ignored behavioral pain tolerance. CONCLUSION: These findings highlight the importance of assessing pain tolerance thresholds in youth with emotional abuse and improving pain tolerance to prevent social anxiety symptoms in youth with different subgroups of CT.

Longitudinal changes in mental health among medical students in China during the COVID-19 epidemic: depression, anxiety and stress at 1-year follow -up.

This study aimed to evaluate the influence of COVID-19 on the mental health of Chinese medical students at 1-year of follow-up. From 2 February 2020 to 23 February 2021, we conducted three waves of research online (T1 = during outbreak, T2 = controlling period, T3 = 1 year after outbreak). The survey collected demographic data and several self reporting questionnaires to measure the depressive, anxiety and stress symptoms. A total of 4002 participants complete the whole research phases. The study major, grade level and gender were the main factors related to psychological distress caused by the COVID-19 crisis. Importantly, medical knowledge has a protective effect on medical students' psychological distress during the COVID-19 period.

Synthesis of Benzisothiazole-Azo Disperse Dyes for High Resistance to Alkaline Treatments and Peroxide Bleaching of Polyester and Polyester/Cotton Fabric.

We proposed in this paper to design and synthesize a series of benzisothiazole-based heterocyclic azo disperse dyes with high resistance to alkali and peroxide. These newly synthesized disperse dyes were confirmed using 1H nuclear magnetic resonance (1H NMR), mass spectroscopy, and a UV-visible spectrophotometer. The resistances to alkali and peroxide were examined by dyeing polyester fabric with these synthesized disperse dyes in sodium hydroxide solution and alkaline hydrogen peroxide solution, respectively. It was found that the disperse dyes having cyano and hydroxyl groups exhibited poor resistance to alkali and peroxide. When the cyano and hydroxyl groups were substituted with ethyl, benzyl, and p-methylbenzyl groups, the synthesized disperse dyes exhibited extremely high resistance to alkali and peroxide. Utilizing the high resistance to alkali and peroxide of synthesized disperse dyes, the polyester suede fabric and polyester/cotton blended fabric could be produced by combining pretreatment with dyeing in one bath. From pilot-plant production based on 1-ton fabric, the one-bath process provided the advantages of saving electric power, steam, water, and man-hour.

Promoting gaze toward the eyes of emotional faces in individuals with high autistic traits using group cognitive behavioral therapy: An eye-tracking study.

BACKGROUND: Individuals with subclinical autistic traits exhibit a pattern of eye avoidance similar to that of typical autism. Our study aimed to test the efficacy of group cognitive behavioral therapy (G-CBT) in promoting gaze toward the eye area of facial expressions, specifically orienting to emotional faces, in individuals with high autistic traits (high AT). METHODS: Twenty-six high AT individuals and 30 low AT individuals participated. High AT individuals were assigned to eight sessions of G-CBT intervention. Eye-tracking measurements were acquired before and after treatment. RESULTS: We observed the following: (a) the eye avoidance in high AT individuals was prominent for all facial expressions in relative to low AT individuals; (b) G-CBT primarily improved gaze toward the eyes of happy and fearful faces but not for neutral face expressions in high AT individuals; (c) after 8 sessions of G-CBT, the fixation time on the eyes of emotional faces improved significantly. For happy faces, the fixation time on the eyes of faces was markedly increased in epochs between 500 ms and 1000 ms after the face onset; for fearful faces, the improvement in participants existed between about 1000 ms and 1500 ms after the face appeared. LIMITATION: Our results may not be generalized to other patients with ASD. CONCLUSIONS: Our findings demonstrate that G-CBT significantly promotes gaze toward the eyes of emotional faces in high AT individuals. These results are encouraging, and suggest that the emotional face processing in autism spectrum disorder (ASD) might stand to benefit from similar psychotherapeutic treatment.

High-definition transcranial direct current stimulation modulates eye gaze on emotional faces in college students with alexithymia: An eye-tracking study.

BACKGROUND: Atypical eye gaze on emotional faces is a core feature of alexithymia. The inferior frontal gyrus (IFG) is considered to be the neurophysiological basis of alexithymia-related emotional face fixation. Our aim was to examine whether anodal high-definition transcranial direct current stimulation (HD-tDCS) administered to the right (r)IFG would facilitate eye gaze of emotional faces in alexithymia individuals. METHOD: Forty individuals with alexithymia were equally assigned to anodal or sham HD-tDCS of the rIFG according to the principle of randomization. The individuals then completed a free-viewing eye tracking task (including happy, sad, and neutral faces) before and after 5 consecutive days of stimulation (twice a day). RESULTS: The results showed that twice a day anodal HD-tDCS of the rIFG significantly increased the fixation time and fixation count of the eye area on happy and neutral faces, but there was no significant effect on sad faces. According to the temporal-course analysis, after the intervention, the fixation time on neutral faces increased significantly at almost all time points of the eye tracking task. For happy faces, the improvement was demonstrated between 500 and 1000 ms and between 2500 and 3500 ms. For sad faces, the fixation time improved but not significantly. CONCLUSIONS: Applying high-dose anodal HD-tDCS to the rIFG selectively facilitated eye gaze in the eye area of neutral and happy faces in individuals with alexithymia, which may improve their face processing patterns.

Enhancing the Dyeability of Polyimide Fibers with the Assistance of Swelling Agents.

Polyimide (PI) fibers have outstanding thermal stability and mechanical properties, but are difficult to dye with disperse and basic dyes. In this work, it was proposed to use N-methylformanilide (MFA), phenoxyisopropanol (PIP), and acetophenone (AP) as swelling agents to enhance the dyeability of PI fibers. The PI fibers treated with swelling agents were characterized by thermal gravimetric analysis, scanning electronic microscopy, tensile testing, and crystalline analysis. It was found that the swelling agents penetrated into the PI fibers in amounts greater than 10% (pertaining to the weight of PI fibers). The swelling agents did not really swell the PI fibers, but broke the interaction forces between the PI macromolecules. With the assistance of swelling agent, the PI fibers could be dyed with disperse and basic dyes in strong color strengths. AP exhibited the best performance for enhancing the dyeability of PI fibers, followed by MFA and PIP. The dyed PI fibers were found to have good colorfastness to washing.

A nonlinear isotherm model for sorption of anionic dyes on cellulose fibers: a case study.

The sorption data of an anionic dye on cellulose fiber are often correlated with a log-linear model to determine the internal accessible volume of the fiber to the anionic dye (V, L/kg) and as such the standard affinity of the anionic dye to the fiber (-Δµ°, J/mol), but without taking into account the influence of ionized carboxyl groups due to cellulose oxidation ([COO(-)]f, mol/kg). In this study, a nonlinear isotherm model was derived by incorporating [COO(-)]f, V and -Δµ° as three model parameters. A set of classical sorption data of C. I. Direct Blue 1 on bleached cotton was correlated with the nonlinear isotherm model. The nonlinear curve fitting analysis showed that the nonlinear isotherm model was in excellent agreement with the sorption data and robust to determine the values of [COO(-)]f, V and -Δµ° for describing the sorption behaviors of anionic dyes on cellulose fibers.

The TAED/H2O2/NaHCO3 system as an approach to low-temperature and near-neutral pH bleaching of cotton.

A low-temperature and near-neutral pH bleaching system was conceived for cotton by incorporating TAED, H2O2 and NaHCO3. The TAED/H2O2/NaHCO3 system was investigated and optimized for bleaching of cotton using a central composite design (CCD) combined with response surface methodology (RSM). CCD experimental data were fitted to create a response surface quadratic model (RSQM) describing the degree of whiteness of bleached cotton fabric. Analysis of variance for the RSQM revealed that temperature was the most significant variable, followed by [TAED] and time, while [NaHCO3] was insignificant. An effective system was conducted by adding 5.75 g L(-1) TAED together with H2O2 and NaHCO3 at a molar ratio of 1:2.4:2.8 and applied to bleaching of cotton at 70 °C for 40 min. Compared to a commercial bleaching method, the TAED/H2O2/NaHCO3 system provided cotton with comparable degree of whiteness, slightly inferior water absorbency and acceptable dyeability, but had competitive advantage in protecting cotton from severe chemical damage in bleaching.

A critical reinvestigation of the TAED-activated peroxide system for low-temperature bleaching of cotton.

There exists a misunderstanding on the TAED-activated peroxide system in the textile industry that H(2)O(2) used in excess of the stoichiometric amount could produce an addition effect on bleaching of cotton under alkaline conditions. In this study, a critical reinvestigation was carried out on the TAED-activated peroxide system for bleaching of cotton. It was found that the TAED-activated peroxide system achieved its best performance under near-neutral pH conditions. No addition effect was observed when an excessive amount of H(2)O(2) was used under alkaline conditions, which is probably due to the base-catalyzed bimolecular decomposition of peracetic acid and the nucleophilic attack by H(2)O(2) on peracetic acid. NaHCO(3) was shown to be a desired alkaline agent for maintaining near-neutral pH for the TAED-activated peroxide system. This study provides new insight into the application of the TAED-activated peroxide system for low-temperature bleaching of cotton under more environmentally benign conditions.

Profiles of liquid drops at the bottom of cylindrical fibers standing on flat substrates.

Based on Carroll's derivation that describes a symmetric liquid drop sitting on an infinite cylindrical fiber and the shape of the drop, we have extended the derivation to describe a drop located at the bottom of cylindrical fibers standing on flat substrates. According to our derivation, the shape of the drop forms a bell as predicted by Carroll but is cut off by the flat substrate. This theoretical prediction was verified experimentally using water, ethylene glycol, and Kaydol drops on glass, nylon and polypropylene cylindrical fibers, and on polytetrafluoroethylene (PTFE) and polyester (PET) flat substrates. We found that only four parameters are required to obtain agreement between the theoretical shape and the observed shape: the drop volume, the fiber radius, the liquid-fiber contact angle, and liquid-flat substrate contact angle.

Gibbs free energy of liquid drops on conical fibers.

Small drops can move spontaneously on conical fibers. As a drop moves along the cone, it must change shape to maintain a constant volume, and thus, it must change its surface energy. Simultaneously, the exposed surface area of the underlying cone must also change. The associated surface energies should balance each other, and the drop should stop moving when it reaches a location where the free energy is a minimum. In this paper, a minimum Gibbs free energy analysis has been performed to predict where a drop will stop on a conical fiber. To obtain the Gibbs free energies of a drop at different locations of a conical fiber, the theoretical expressions for the shape of a droplet on a conical fiber are derived by extending Carroll's equations for a drop on a cylindrical fiber. The predicted Gibbs free energy exhibits a minimum along the length of the cone. For a constant cone angle, as the contact angle between the liquid and the cone increases, the drop will move toward the apex of the cone. Likewise, for a constant contact angle, as the cone angle increases, the drop moves toward the apex. Experiments in which water and dodecane were placed on glass cones verify these dependencies. Thus, the final location of a drop on a conical fiber can be predicted on the basis of the geometry and surface energy of the cone, the surface tension and volume of the liquid, and the original location where the drop was deposited.

Profiles of liquid drops at the tips of cylindrical fibers.

In 1976, B. J. Carroll derived the equation to show that a symmetric liquid droplet sitting on a thin cylindrical fiber would acquire a bell shape at equilibrium. We have extended his derivation to describe a drop located at the top end of a vertical, cylindrical fiber. By minimizing the Gibbs free energy of the drop at the fiber tip, it was found that the drop consists of two portions, a spherical cap on the fiber tip and a full, symmetrical bell located on the fiber body adjacent to the fiber tip. The experimental verification of the predicted shapes was performed using water, ethylene glycol, and Kaydol drops on nylon cylindrical fibers. Only four parameters are required to obtain agreement between the theoretical shape and the observed shape: the drop volume, the fiber radius, the surface tension of the liquid, and the Young contact angle of the liquid on a flat surface of the same composition as the fiber.