1,638 research outputs found
Application of Computational Chemical Shift Prediction Techniques to the Cereoanhydride Structure Problem-Carboxylate Complications.
Despite the vast array of techniques available to modern-day chemists, structural misassignments still occur. These misassignments are often only realized upon attempted synthesis, when the spectra of synthesized products do not match previously reported spectra. This was the case with marine natural product cereoanhydride. The originally proposed 7-membered ring anhydride (1) was shown to be incorrect, although a likely precursor to the correct structure (2) in both its laboratory synthesis and biosynthesis. Herein, in addition to showing how NMR computations could have been used to arrive at the correct structure, we show that the conversion of 1 to 2 is indeed energetically viable, and we highlight complications in predicting NMR chemical shifts for molecules with acidic protons
Evaluation of a Systems Navigator Model for Transition From Pediatric to Adult Care for Young Adults With Type 1 Diabetes
OBJECTIVES— To determine whether a systems navigator service, The Maestro Project, could increase medical surveillance for young adults with type 1 diabetes who transfer from pediatric to adult care
Effective chacteristics of Iranian nursing students in their relationship with clinical nurses
Introduction: The purpose of this study was to explore the characteristics of undergraduate nursing students, which may determine the nature of their relationship with clinical nurses. Relationships between nursing students and clinical nurses are critical to maximize student learning outcomes and produce skilled graduates for the future health workforce. Methods: This qualitative content analysis study was conducted from January to August 2016. Twenty nine semi-structured in-depth interviews were conducted with 20 undergraduate nursing students in Tabriz nursing and midwifery faculty. Interviews were recorded and transcribed verbatim (in Persian), and analyzed using conventional content analysis to identify themes. Results: Four key themes emerged: educational factors (cognitive knowledge and practical skills, and learning motivation); communication skills; perceived support (perceived support from nurses and educators); and psychological state (fear of the relationship and self-confidence). Self-confidence is an emphasized concept in nursing students' willingness and ability to relate with clinical nurses. Conclusion: The results of the study showed that educational, communicative and psychological factors are important determinants of student communication with nurses. However, self-confidence is the most important factor in establishing such relationship. Self-confidence could be further assessed to identify nursing students who need greater support or would benefit from greater educational interventions to achieve relational skills
Does naltrexone treatment lead to depression? Findings from a randomized controlled trial in subjects with opioid dependence
Objective: Dysphoria and depression have been cited as side effects of the opioid antagonist naltrexone. We aimed to assess whether depressive symptoms are a clinically relevant side effect in a population receiving naltrexone as a treatment for opioid dependence. Methods: We carried out a randomized controlled, open-label trial comparing rapid opiate detoxification under anesthesia and naltrexone treatment with continued methadone maintenance at the Alcohol and Drug Service, Royal Brisbane and Women's Hospital, Brisbane, Australia. The study subjects were patients stabilized on methadone maintenance treatment for heroin dependence who wished to transfer to naltrexone treatment. The Beck Depression Inventory, State-Trait Anxiety Inventory and Opiate Treatment Index subscales for heroin use and social functioning were used at baseline and follow-up assessments at 1, 2, 3 and 6 months. Results: Forty-two participants were allocated to receive naltrexone treatment, whereas 38 continued methadone maintenance as the control condition. Participants who received naltrexone did not exhibit worsening of depressive symptoms. In participants attending all follow-up assessments, there was a trend for those receiving naltrexone to exhibit an improvement in depression over time compared with the control group. Participants who were adherent to naltrexone treatment exhibited fewer depressive symptoms than those who were nonadherent. Conclusions: These results suggest that depression need not be considered a common adverse effect of naltrexone treatment or a treatment contraindication and that engaging with or adhering to naltrexone treatment may be associated with fewer depressive symptoms
Relations Among Gender, Violence Exposure, and Mental Health: The National Survey of Adolescents
Using a nationally representative sample of 4,008 adolescents, this study examines gender differences in violence exposure, major depressive episode (MDE) and posttraumatic stress disorder (PTSD), and characteristics of violence incidents. It was hypothesized that there would be gender differences in the types of violence exposure reported as well as the prevalence of MDE and PTSD; and that gender would moderate the relationship between violence exposure and mental health outcomes. Results indicated significant gender differences in rates of violence exposure, PTSD and MDE. Additionally, gender was a moderating variable in the relation between sexual assault and PTSD, but not in the other violence exposure-mental health relations examined. It thus appears that the pathways for developing PTSD may be different for male and female victims of sexual abuse. Implications for interventions and future research are discussed
Students’ Perceptions of Online Learning to Inform Jesuit Education
A small group of faculty, staff, and administrators, known as the Online Learning Community (OLC) were collectively interested in enriching online learning at a Jesuit university. With a culture at this Jesuit and Mercy university driven by face-to-face (F2F) learning, the first step was to assess students’ perceptions of online learning from students who have taken online courses at the university. The survey, guided by best instructor practices in online learning and Jesuit philosophy, traditions, and concepts, was designed to explore students’ perceptions, experiences, and practices in online learning. Students (N=484) self-enrolled in the study and included students from all the colleges in the university and across four campuses. The most notable response in the data was students’ (72%) desire for more online learning opportunities at the host university. The freedom and flexibility afforded in online classes was prevalent in students open-ended statements about online learning but additionally emphasized the importance of instructor qualities of being organized in course delivery, availability, and effective communication skills. In this study, OLC members sought to place students’ perceptions at the core of efforts to inform online learning at this Jesuit and Mercy university. The findings enrich and demonstrate linkages with core Jesuit traditions and concepts
Overscreening and Underscreening in Solid-Electrolyte Grain Boundary Space-Charge Layers
Polycrystalline solids can exhibit material properties that differ
significantly from those of equivalent single-crystal samples, in part, because
of a spontaneous redistribution of mobile point defects into so-called
space-charge regions adjacent to grain boundaries. The general analytical form
of these space-charge regions is known only in the dilute limit, where
defect-defect correlations can be neglected. Using kinetic Monte Carlo
simulations of a three-dimensional Coulomb lattice gas, we show that
grain-boundary space-charge regions in non-dilute solid electrolytes exhibit
overscreening -- damped oscillatory space-charge profiles -- and underscreening
-- decay lengths that are longer than the corresponding Debye length and that
increase with increasing defect-defect interaction strength. Overscreening and
underscreening are known phenomena in concentrated liquid electrolytes, and the
observation of functionally analogous behaviour in solid electrolyte
space-charge regions suggests that the same underlying physics drives behaviour
in both classes of systems. We therefore expect theoretical approaches
developed to study non-dilute liquid electrolytes to be equally applicable to
future studies of solid electrolytes
Taxometric Investigation of PTSD: Data From Two Nationally Representative Samples
Current psychiatric nosology depicts posttraumatic stress disorder (PTSD) as a discrete diagnostic category. However, only one study has examined the latent structure of PTSD, and this study suggested that PTSD may be more accurately conceptualized as an extreme reaction to traumatic life events rather than a discrete clinical syndrome. To build on the existing literature base, the present research examined the latent structure of posttraumatic stress reactions by applying three taxometric procedures (MAXEIG, MAMBAC, and L-Mode) to data collected from large nationally representative samples of women (ns = 2684 and 3033) and adolescents (n = 3775). Results consistently provided evidence for a dimensional PTSD solution across samples and statistical procedures. These findings have important implications for the theory, assessment, and investigation of posttraumatic stress reactions
Identifying factors associated with sedentary time after stroke. Secondary analysis of pooled data from nine primary studies.
<p><b>Background</b>: High levels of sedentary time increases the risk of cardiovascular disease, including recurrent stroke.</p> <p><b>Objective</b>: This study aimed to identify factors associated with high sedentary time in community-dwelling people with stroke.</p> <p><b>Methods</b>: For this data pooling study, authors of published and ongoing trials that collected sedentary time data, using the activPAL monitor, in community-dwelling people with stroke were invited to contribute their raw data. The data was reprocessed, algorithms were created to identify sleep-wake time and determine the percentage of waking hours spent sedentary. We explored demographic and stroke-related factors associated with total sedentary time and time in uninterrupted sedentary bouts using unique, both univariable and multivariable, regression analyses.</p> <p><b>Results</b>: The 274 included participants were from Australia, Canada, and the United Kingdom, and spent, on average, 69% (SD 12.4) of their waking hours sedentary. Of the demographic and stroke-related factors, slower walking speeds were significantly and independently associated with a higher percentage of waking hours spent sedentary (p = 0.001) and uninterrupted sedentary bouts of <i>>30</i> and <i>>60 min</i> (p = 0.001 and p = 0.004, respectively). Regression models explained 11–19% of the variance in total sedentary time and time in prolonged sedentary bouts.</p> <p><b>Conclusion</b>: We found that variability in sedentary time of people with stroke was largely unaccounted for by demographic and stroke-related variables. Behavioral and environmental factors are likely to play an important role in sedentary behavior after stroke. Further work is required to develop and test effective interventions to address sedentary behavior after stroke.</p
Control de estímulos de efectos del castigo: Determinando las variables controladoras
El estudio del control discriminativo de estímulos de una respuesta mantenidapor reforzamiento positivo ha jugado un papel extenso y dominante en laliteratura conductual. En contraste, la literatura sobre el control discriminativode la respuesta de supresión por castigo es pequeña y moribunda. Investigarla forma del control de estímulos que se desarrolla bajo condiciones de castigoes un tópico que necesita más atención por razones teóricas y prácticas.En preparaciones en las cuales el control de estímulos se puede desarrollar(e.g., programas múltiples), al menos dos estímulos pueden llegar a ejercerun control discriminativo sobre la supresión de la respuesta: un estímulo discriminativoantecedente (e.g., estímulos en programas múltiples) y la entregamisma del castigador. Revisamos la literatura básica y aplicada sobre el castigoy encontramos sólo unas pocas demostraciones claras de control de estímulosoperante por un estímulo antecedente. Discutimos las limitaciones delos métodos, así como las convenciones de análisis y presentación de datos,que impiden conclusiones claras sobre el establecimiento de un control deestímulo antecedente con el castigo. Una consideración de estas limitacioneses importante porque son relevantes para problemas básicos y aplicados enel análisis de la conducta
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