Band structure and band topology in twisted homotrilayer transition metal dichalcogenides

We investigate a simplified continuum model of a twisted homotrilayer TMD with negligible next-nearest layer couplings. We systematically analyze band structure and topology of various stacking configurations in a twist angle range from $1^\circ$ to $4^\circ$. This allows us to uncover a plethora of topological transitions as well as various angle regimes with flat bands - some of them topologically non-trivial, which are of growing interest for the realization of exotic strongly correlated phases. Additionally, we uncover surprising properties, such as that for certain stacking configurations, some layers effectively decouple from other layers. In this case, the only remnant of coupling between layers is a layer-dependent energy shift.Comment: 12 pages, 8 figure

Factors mediating the impacts of child abuse and intimate partner violence on chronic pain: A cross-sectional study 11 Medical and Health Sciences 1117 Public Health and Health Services 17 Psychology and Cognitive Sciences 1701 Psychology

Background: Most research on the health impacts of intimate partner violence (IPV) and child abuse has been conducted in Western countries and may not be generalizable to women living in different contexts, such as Saudi Arabia. Chronic pain, a disabling health issue associated with experiences of both child abuse and IPV among women, negatively impacts women\u27s well-being, quality of life, and level of functioning. Yet, the psychosocial mechanisms that explain how abuse relates to chronic pain are poorly understood. We developed and tested a theoretical model that explains how both IPV and child abuse are related to chronic pain. Methods: We recruited a convenience sample of 299 Saudi women, who had experienced IPV in the past 12 months, from nine primary health care centers in Saudi Arabia between June and August 2015. Women completed a structured interview comprised of self-report measures of IPV, child abuse, PTSD, depressive symptoms, chronic pain, and social support. Using Structural equation modeling (SEM), we analyzed the proposed model twice with different mental health indicators as mediators: PTSD symptoms (Model 1) and depressive symptoms (Model 2). Results: Both models were found to fit the data, accounting for 31.6% (Model 1) and 32.4% (Model 2) of the variance in chronic pain severity. In both models, mental health problems (PTSD and depressive symptoms) fully mediated the relationship between severity of IPV and child abuse and chronic pain severity. Perceived family support partially mediated the relationship between abuse severity and depressive symptoms. Conclusions: These results underscore the significance of considering lifetime abuse, women\u27s mental health (depressive and PTSD symptoms) and their social resources in chronic pain management and treatment

Non-suicidal self-strangulation among adolescents in Saudi Arabia: Case series of the choking game

AbstractAdolescence is known to be a time of exploration and initiation of risky behaviors. Much attention has been given to risk behaviors such as smoking, violence, and sexual promiscuity; other serious behaviors such as self-strangulation or the choking game, which is carried out by adolescents in response to peer pressures or to gain a transient sense of euphoria, have received little attention, with the available literature coming from the developed world.This is the first report of cases of non-suicidal self-strangulation from the Arab World. In this case series, we report 5 cases of non-suicidal self-strangulation that presented to the Emergency Department of a tertiary care hospital in Riyadh, Saudi Arabia during 2010–2012. All of the 5 cases were young male adolescents aged 10–13 years. This activity resulted in the death of 2 boys; one boy sustained hypoxic ischemic insult to the brain with clinical deficits; and the remaining 2 were fortunate to be discharged home in healthy condition. None of the cases had underlying mental health problems, and multidisciplinary involvement ruled out suicide and homicide activities.Non-suicidal self-strangulation is a fatal behavior that adolescents engage in. Increased efforts are needed to address this serious and preventable public health issue. Awareness and education of adolescents and their parents is crucial. Awareness of healthcare providers is also necessary in order to avoid misdiagnosis of such cases

Inadequate timing of prophylactic antibiotics in orthopedic surgery. We can do better

Background and purpose There are rising concerns about the frequency of infection after arthroplasty surgery. Prophylactic antibiotics are an important part of the preventive measures. As their effect is related to the timing of administration, it is important to follow how the routines with preoperative prophylactic antibiotics are working