BackgroundPost-traumatic stress disorder (PTSD) is a common psychological disorder caused by unusual threats or catastrophic events. Little is known about the combined incidence of PTSD after earthquakes. This study aimed at evaluating the combined incidence of PTSD among survivors after earthquakes using systematic review and meta-analysis.MethodsThe electronic databases of PubMed, Embase, Web of Science and PsycARTICLES were searched for relevant articles in this study. Loney criteria were used to assess the quality of eligible articles. The combined incidence of PTSD was estimated by using the Freeman-Tukey double arcsine transformation method. Subgroup analyses were conducted using the following variables: the time of PTSD assessment, gender, educational level, marital status, damage to one’s house, bereavement, injury of body and witnessing death.ResultsForty-six eligible articles containing 76,101 earthquake survivors met the inclusion criteria, of which 17,706 were diagnosed as having PTSD. Using a random effects model, the combined incidence of PTSD after earthquakes was 23.66 %. Moreover, the combined incidence of PTSD among survivors who were diagnosed at not more than 9 months after earthquake was 28.76 %, while for survivors who were diagnosed at over nine months after earthquake the combined incidence was 19.48 %. A high degree of heterogeneity (I2 = 99.5 %, p<0.001) was observed in the results, with incidence ranging from 1.20 to 82.64 %. The subgroup analyses showed that the incidence of PTSD after earthquake varied significantly across studies in relation to the time of PTSD assessment, gender, educational level, damage to one’s house, bereavement, injury of body and witnessing death. However, stratified analyses could not entirely explain the heterogeneity in the results.ConclusionsGiven the high heterogeneity observed in this study, future studies should aim at exploring more possible risk factors for PTSD after earthquakes, especially genetic factors. In spite of that, the results of this study suggest that nearly 1 in 4 earthquake survivors are diagnosed as having PTSD. Therefore, the local government should plan effective psychological interventions for earthquake survivors.Electronic supplementary materialThe online version of this article (doi:10.1186/s12888-016-0891-9) contains supplementary material, which is available to authorized users.

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Adolescents experience various forms of strain in their lives that may contribute jointly to their engagement in cyber aggression. However, little attention has been given to this idea. To address this gap in the literature, the present longitudinal study examined the moderating influence of peer rejection on the relationship between cyber victimization at Time 1 (T1) and subsequent cyber aggression at Time 2 (T2; 6 months later) among 261 (150 girls) 6th, 7th, and 8th graders. Our findings indicated that both peer rejection and cyber victimization were related to T2 peer-nominated and self-reported cyber aggression, both relational and verbal, after controlling for gender and T1 cyber aggression. Furthermore, T1 cyber victimization was related more strongly to T2 peer-nominated and self-reported cyber aggression at higher levels of T1 peer rejection. These results extend previous findings regarding the relationship between peer rejection and face-to-face aggressive behaviors to the cyber context. In addition, our findings underscore the importance of utilizing multiple methods, such as peer-nomination and self-report, to assess cyber aggression in a school setting.

Cross-situational continuity and change in anxious solitary girls' behavior and peer relations were examined in interactions with familiar versus unfamiliar playmates. Fourth-grade girls (N=209, M age=9.77 years, half African American, half European American) were identified as anxious solitary or behaviorally normative using observed and teacher-reported behavior among classmates. Subsequently, girls participated in 1-hr play groups containing 5 same-race familiar or unfamiliar girls for 5 consecutive days. Results support both cross-situational continuity and change in anxious solitary girls' behavior and peer relations. Although anxious solitary girls exhibited difficulty interacting with both familiar and unfamiliar playmates relative to behaviorally normative girls, elements of their behavior improved in unfamiliar play groups, a context in which they received less peer mistreatment.

A fast and efficient proteolysis approach of microwave-assisted protein digestion was developed by using trypsin-immobilized magnetic silica (MS) microspheres. In the work, immobilization of the enzyme onto MS microspheres was very simple and only through a one-step reaction with 3-glycidoxypropyltrimethoxysilane (GLYMO) which provides the epoxy group as a reactive spacer. Considering that the magnetic particles are excellent microwave absorbers, we developed a novel microwave-assisted digestion method based on the easily prepared trypsin-immobilized MS microspheres. This novel digestion method combined the advantages of immobilized trypsin and the rapid-fashion of microwave-assisted digestion, which resulted in high digestion efficiency. BSA and myoglobin were used as model proteins to optimize the conditions of this method. Peptide fragments produced in 15 s could be confidently identified by matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF MS) analysis. Equivalent or better digestion efficiency was observed comparing to current in-solution digestion. Besides, because of the unique magnetic responsivity, the immobilized trypsin can be isolated easily with the help of an external magnet and thus used repeatedly. High activity was obtained even after seven runs of the trypsin-immobilized MS microspheres. To further verify its efficiency in proteome analysis, one reversed-phase liquid chromatography (RPLC) fraction of rat liver extract was applied. After 15 s incubation, 16 totally unique peptides corresponding to two proteins were identified. Finally, the rat liver sample was used to evaluate its worth for the application. With analysis by liquid chromatography-electrospray-tandem mass spectrometry (LC-ESI-MS/MS), comparable digestion efficiency was observed with typical in-solution digestion but the incubation time was largely shortened. This new microwave-assisted digestion method will hasten the application of the proteome technique to biomedical and clinical research.

In this work, a novel and facile route was developed for the immobilization of enzyme on nanosized magnetic particles, and its application to fast protein digestion via a direct MALDI-TOF mass spectrometry analysis was demonstrated. At first, amine-functionalized magnetic particles with high magnetic responsivity and excellent dispersibility were prepared through a facile one-pot strategy. Then, magnetic nanoparticles were functionalized with numerous aldehyde(-CHO) groups by treating the as-synthesized, amine-functionalized magnetic nanoparticles with glutaraldehyde. Finally, immobilization of trypsin onto the aldehyde-functionalized magnetic nanoparticles was achieved through reaction of the aldehyde groups with amine groups of trypsin. The obtained trypsin-immobilized magnetic nanoparticles were conveniently applied for protein digestion. The digestion efficiency was demonstrated with peptide mapping analysis of three model proteins. The process of digestion is very facile due to the easy manipulation of magnetic nanoparticles. Complete protein digestion was achieved in a short time (5 min), without any complicated reduction and alkylation procedures. These results are expected to open up a new possibility for the proteolysis analysis as well as a new application of magnetic nanoparticles. Additionally, it is worth noting that, since the preparation and surface functionality of magnetic nanoparticles is low-cost and reproducible, the preparation method and application approach of the magnetic nanoparticles may find much potential in proteome research.

Sample preparation is a fundamental step in the proteomics and peptidomics workflow. Due to their good biocompatibility, superparamagnetic property, and high binding capacity, magnetic nanoparticles (MNPs) functionalized with different active moieties have been widely applied in recent years in various sample preparation procedures in proteomics and peptidomics analysis. The magnetic cores of the MNPs facilitate elegant handling using only magnetic devices and their small diameters are advantageous for increasing the sensitivity when using subsequent mass spectrometry (MS) analysis or gel electrophoresis. This review mainly focuses on overviewing present advances in the preparation and application of functionalized magnetic nanoparticles for sample preparation in proteomics and peptidomics analysis, including protein digestion, enrichment of low-abundance peptides/proteins and specific enrichment of peptides/proteins with post-translational modifications, such as phosphorylation and glycosylation.

This longitudinal study examined normative beliefs about aggression (e.g., face-to-face, cyber) in relation to the engagement in cyber aggression 6 months later among 126 (69 women) young adults. Participants completed electronically administered measures assessing their normative beliefs, face-to-face and cyber aggression at Time 1, and cyber aggression 6 months later (Time 2). We found that men reported more cyber relational and verbal aggression when compared to women. After controlling for each other, Time 1 face-to-face relational aggression was positively related to Time 2 cyber relational aggression, whereas Time 1 face-to-face verbal aggression was positively related to Time 2 cyber verbal aggression. Normative beliefs regarding cyber aggression was positively related to both forms of cyber aggression 6 months later, after controlling for normative beliefs about face-to-face aggression. Furthermore, a significant two-way interaction between Time 1 cyber relational aggression and normative beliefs about cyber relational aggression was found. Follow-up analysis showed that Time 1 cyber relational aggression was more strongly related to Time 2 cyber relational aggression when young adults held higher normative beliefs about cyber relational aggression. A similar two-way interaction was found for cyber verbal aggression such that the association between Time 1 and Time 2 cyber verbal aggression was stronger at higher levels of normative beliefs about cyber verbal aggression. Results are discussed in terms of the social cognitive and behavioral mechanisms associated with the engagement of cyber aggression.