A Technique For The Evaluation Of Double Excitation Of Atoms By Fast Protons And Antiprotons

A technique for evaluating cross sections for two-electron excitation in collisions of atoms with fast particles of charge ZP is presented. The atomic wave function is approximated by a sum of pair products of one-electron wave functions, with the coefficients chosen by diagonalizing the fully correlated twoelectron Hamiltonian. Thus spatial correlation is included in both the asymptotic and scattering regions by using these configuration-interaction (Cl) wave functions for initial, intermediate, and final states. Use of CI wave function also allows the first-order contributions to be expressed in closed, analytical form. Both the energy-conserving and energy-nonconserving parts of the second-order amplitude are evaluated. The former (a correlated generalization of the independent-electron approximation) is analytical and the latter is a one-dimensional integral. In helium it is found that the double-excitation cross sections are sensitive to the sign of the projectile charge, but that the energy region where this sensitivity is of the same order as for double ionization is 0.1 to 0.5 Me V /amu, whereas the latter has peak charge sensitivity at 1.5 MeV /amu. Comparison is made with some experimental results

Synergistic Antitumor Activity of Vitamins C and K3 on Human Bladder Cancer Cell Lines

Copyright © 2013 Karen McGuire et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Exponentially growing cultures of human bladder tumor cells (RT4 and T24) were treated with Vitamin C (VC) alone, Vitamin K3 (VK3) alone, or with a VC:VK3 combination continuously for 5 days or treated with vitamins for 1 h, washed with PBS and then incubated in culture medium for 5 days. Co-administration of the vitamins enhanced the antitumor activity 12- to 24-fold for the RT-4 cells and 6- to 41-fold for the T24 cells. Flow cytometry of RT4 cells ex-posed to the vitamins revealed a growth arrested population and a population undergoing cell death. Growth arrested cells were blocked near the G0/G1-S-phase interface, while cell death was due to autoschizis. Catalase treatment abro-gated both cell cycle arrest and cell death which implicated hydrogen peroxide (H2O2) in these processes. The H2O2 production resulted in a moderate increase in lipid peroxidation and depletion of cell thiol levels. Analysis of cellular ATP levels revealed a transient increase in ATP production for VC and the VC:VK3 combination, but decreased ATP levels following VK3 treatment. Lipid peroxidation, thiol depletion and ATP modulation occurred at a 17-fold lower concentration in the vitamin combination than with either vitamin alone. These results suggested that the increased cy-totoxicity of the vitamin combination was due to redox cycling and increased oxidative stress

High-velocity Limits for the Ratio of Double to Single Ionisation of Helium by Projectiles with Electrons

The ratio of total double to total single ionisation cross sections, R, by high velocity projectiles containing electrons is examined in the first Born approximation. For ionisation of helium by H+, H0 and He0 impact, it is found that t filt H+ \u3c filt Ho \u3c filt Heo . Connection with Bohr\u27s free-collision model for collisions with projectile electrons is given

Recoil Distributions in Particle Transfer

Classical Thomas peaks in various fast second-order particle transfer processes are quantum mechanically broadened by energy nonconservation in the intermediate states of collision. This quantum broadening is considered in observable velocity distributions of recoil particles

What Do We Know About Online Romance Fraud Studies? A Systematic Review of the Empirical Literature (2000 to 2021)

We aimed to identify the critical insights from empirical peer-reviewed studies on online romance fraud published between 2000 and 2021 through a systematic literature review using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) protocol. The corpus of studies that met our inclusion criteria comprised twenty-six studies employing qualitative (n = 13), quantitative (n = 11), and mixed (n = 2) methods. Most studies focused on victims, with eight focusing on offenders and fewer investigating public perspectives. All the victim-focused studies relied on data from the Global North, except for Malaysia. Five offender-focused studies used online data available in the public domain, and three derived their data from West Africa. Our review highlights offenders' techniques to deceive and manipulate victims, as revealed in these studies, and highlights some limitations of offender- and victim-focused studies. The dominant framework used across the studies was found to be the “Scammers Persuasive Techniques Model.” While this framework provides a helpful way of considering the stages of victim involvement, it also faces some limitations, which we highlight. Our study reviews the current state of empirical knowledge on romance fraud and identifies certain gaps and biases in the literature. We argue there is a need for further research into online romance fraud to enhance our understanding of it both from the perspective of the offender as well as the experience of the victim. We also highlight the need for a more inclusive and greater range of regional and global diverse range of data sources and perspectives. Given the scale and impact of online romance fraud, we conclude that its study would benefit from a richer empirical engagement that recognizes it as both a regional and global phenomenon

The Role of Attachment Style, Adverse Childhood Experiences and Dissociation in Migraine

35 pagesMigraine and chronic migraine are caused by a combination of modifiable and non-modifiable genetic, social, behavioral and environmental risk factors. Further research of possible modifiable risk factors for this headache disorder is merited, given its role as one of the leading causes of years lived with disability per year. The first aim of this online cross-sectional study was to investigate the psychosocial risk factors that predicted chronic migraine and severe migraine-related disability in 507 Irish and UK participants, focusing specifically on childhood maltreatment, attachment and tendency to dissociate, or experience depressed mood and/or anxiety. Additionally, this study aimed to examine variables that mediated the relationships between these psychosocial risk factors and migraine chronicity or severe migraine-related disability. Adjusted binary logistic regression revealed that shutdown dissociation (Odds Ratio [OR] 4.57, 95% Confidence Interval [CI] 2.66–7.85) and severe physical abuse (OR 4.30, 95% CI 1.44–12.83 had significant odds of predicting migraine chronicity, while depression (OR 3.28, 95% CI 1.86–5.77) significantly predicted severe migraine-related disability. Mediation analyses indicated that shutdown dissociation mediated the relationship between seven predictor variables and both chronicity and severe disability including possible predisposing factors emotional abuse, physical neglect, avoidant attachment and anxious attachment. These findings suggest that early life stressors (such as childhood trauma and avoidant attachment style), shutdown dissociation and depression may impact on migraine trajectory. To investigate whether these psychosocial factors are risk factors for migraine chronicity or disability, prospective research should be conducted in this area to account for fluctuations in migraine chronicity over time

Adverse effects of cannabidiol:a systematic review and meta-analysis of randomized clinical trials

Cannabidiol (CBD) is being investigated as a treatment for several medical disorders but there is uncertainty about its safety. We conducted the first systematic review and meta-analysis of the adverse effects of CBD across all medical indications. Double-blind randomized placebo-controlled clinical trials lasting ≥7 days were included. Twelve trials contributed data from 803 participants to the meta-analysis. Compared with placebo, CBD was associated with an increased likelihood of withdrawal for any reason (OR 2.61, 95% CI: 1.38-4.96) or due to adverse events (OR 2.65, 95% CI: 1.04-6.80), any serious adverse event (OR 2.30, 95% CI: 1.18-4.48), serious adverse events related to abnormal liver function tests (OR 11.19, 95% CI: 2.09-60.02) or pneumonia (OR 5.37, 95% CI: 1.17-24.65), any adverse event (OR 1.55, 95% CI: 1.03-2.33), adverse events due to decreased appetite (OR 3.56, 95% CI: 1.94-6.53), diarrhoea (OR 2.61, 95% CI: 1.46-4.67), somnolence (OR 2.23, 95% CI: 1.07-4.64) and sedation (OR 4.21, 95% CI: 1.18-15.01). Associations with abnormal liver function tests, somnolence, sedation and pneumonia were limited to childhood epilepsy studies, where CBD may have interacted with other medications such as clobazam and/or sodium valproate. After excluding studies in childhood epilepsy, the only adverse outcome associated with CBD treatment was diarrhoea (OR 5.03, 95% CI: 1.44-17.61). In summary, the available data from clinical trials suggest that CBD is well tolerated and has relatively few serious adverse effects, however interactions with other medications should be monitored carefully. Additional safety data from clinical trials outside of childhood epilepsy syndromes and from studies of over-the-counter CBD products are needed to assess whether the conclusions drawn from clinical trials can be applied more broadly.</p

Structural Framework for Flight: NASA's Role in Development of Advanced Composite Materials for Aircraft and Space Structures

This serves as a source of collated information on Composite Research over the past four decades at NASA Langley Research Center, and is a key reference for readers wishing to grasp the underlying principles and challenges associated with developing and applying advanced composite materials to new aerospace vehicle concepts. Second, it identifies the major obstacles encountered in developing and applying composites on advanced flight vehicles, as well as lessons learned in overcoming these obstacles. Third, it points out current barriers and challenges to further application of composites on future vehicles. This is extremely valuable for steering research in the future, when new breakthroughs in materials or processing science may eliminate/minimize some of the barriers that have traditionally blocked the expanded application of composite to new structural or revolutionary vehicle concepts. Finally, a review of past work and identification of future challenges will hopefully inspire new research opportunities and development of revolutionary materials and structural concepts to revolutionize future flight vehicles

Exploring the Perceived Impact of Parental PTSD on Parents and Parenting Behaviours—A Qualitative Study

A considerable number of adults who are currently living with posttraumatic stress disorder (PTSD) are also parents caring for at least one biological child. Evidence suggests that parental PTSD can be associated with impairments to certain parenting behaviours, particularly increasing the use of more negative practices. However, most of the evidence to date has been collected using quantitative methodology, which gives limited insight into why such effects might occur. The current study qualitatively explored study the lived experiences of parents currently living with PTSD, within the United Kingdom. Interviews were conducted with 30 parents (16 mothers, 14 fathers) who were recruited via a PTSD research registry, and who had children living at home under the age of 18 years at the time they experienced their trauma. Three main themes were identified: key impacts of the trauma to the parent personally; negative changes to specific parenting outcomes; impact of these parenting changes on the parent’s sense of parental efficacy; and recovery and coping. These findings provide novel insight into the experiences of both mothers and fathers with PTSD, and highlight the multiple challenges faced by parents living with PTSD that extend beyond impairments to themselves as individuals. Potential implications for the implementation of effective support for parents and their families following trauma exposure are considered