Probing Exciton Delocalization in Organic Semiconductors: Insight from Time-Resolved Electron Paramagnetic Resonance and Magnetophotoselection Experiments.

Delocalization of excited states of organic semiconductors is directly related to their efficiency in devices. Time-resolved electron paramagnetic resonance spectroscopy provides unique capabilities in this respect because of its high spectral resolution and capability to probe the geometry and extent of excitons. Using magnetophotoselection experiments, the mode of exciton delocalization, along the backbone or parallel to the π-π stacking direction of the conjugated polymers, can be revealed. We demonstrate the robustness of this approach by applying it to building blocks of a prototypical conjugated polymer showing a symmetry of their excited states being far from ideal for this experiment. This renders magnetophotoselection superior to other approaches because it is applicable to a wealth of other organic semiconductors. The insight gained into exciton delocalization is crucial to the structure-function relationship of organic semiconductors and directly relevant for developing highly efficient materials.

Solvent-mediated aggregate formation of PNDIT2: decreasing the available conformational subspace by introducing locally highly ordered domains.

The high-mobility n-type donor/acceptor polymer PNDIT2 is well-known to form aggregates in solution depending on the solvent used. To gain additional insight into this process, we probed the local environment of triplet excitons in two different solvents and with two different polymer chain lengths using time-resolved electron paramagnetic resonance (TREPR) spectroscopy. Results clearly show aggregation to introduce a high degree of local order in the polymer and to dramatically enhance the delocalisation of the exciton. Furthermore, triplet exciton delocalisation is only affected by the solvent used and hence by aggregate formation, not by chain length. Finally, aggregation changes the mode of delocalisation from intrachain to interchain when forming aggregates, the latter mode dominating as well in thin films. Taken together, TREPR proves to be a valuable tool for investigating aggregation and order in polymers on a molecular length-scale, ideally complementing preceding optical data.

Direct S0→T Excitation of a Conjugated Polymer Repeat Unit: Unusual Spin-Forbidden Transitions Probed by Time-Resolved Electron Paramagnetic Resonance Spectroscopy.

A detailed understanding of the electronic structure of semiconducting polymers and their building blocks is essential to develop efficient materials for organic electronics. (Time-resolved) electron paramagnetic resonance (EPR) is particularly suited to address these questions, allowing one to directly detect paramagnetic states and to reveal their spin-multiplicity, besides its clearly superior resolution compared to optical methods. We present here evidence for a direct S0→T optical excitation of distinct triplet states in the repeat unit of a conjugated polymer used in organic photovoltaics. These states differ in their electronic structure from those populated via intersystem crossing from excited singlet states. This is an additional and so far unconsidered route to triplet states with potentially high impact on efficiency of organic electronic devices.

Developing and piloting a peer mentoring intervention to reduce teenage pregnancy in looked-after children and care leavers: an exploratory randomised controlled trial.

BACKGROUND: Looked-after children (LAC) are at greater risk of teenage pregnancy than non-LAC, which is associated with adverse health and social consequences. Existing interventions have failed to reduce rates of teenage pregnancy in LAC. Peer mentoring is proposed as a means of addressing many of the factors associated with the increased risk of teenage pregnancy in this group. OBJECTIVE: To develop a peer mentoring intervention to reduce teenage pregnancy in LAC. DESIGN: Phase I and II randomised controlled trial of a peer mentoring intervention for LAC; scoping exercise and literature search; national surveys of social care professionals and LAC; and focus groups and interviews with social care professionals, mentors and mentees. SETTING: Three local authorities (LAs) in England. PARTICIPANTS: LAC aged 14-18 years (mentees/care as usual) and 19-25 years (mentors). INTERVENTION: Recruitment and training of mentors; randomisation and matching of mentors to mentees; and 1-year individual peer mentoring. PRIMARY OUTCOME: pregnancy in LAC aged 14-18 years. SECONDARY OUTCOMES: sexual attitudes, behaviour and knowledge; psychological health; help-seeking behaviour; locus of control; and attachment style. A health economic evaluation was also carried out. RESULTS: In total, 54% of target recruitment was reached for the exploratory trial and 13 out of 20 mentors (65%) and 19 out of 30 LAC aged 14-18 years (63%) (recruited during Phases I and II) were retained in the research. The training programme was acceptable and could be manualised and replicated. Recruitment and retention difficulties were attributed to systemic problems and LA lack of research infrastructure and lack of additional funding to support and sustain such an intervention. Mentees appeared to value the intervention but had difficulty in meeting weekly as required. Only one in four of the relationships continued for the full year. A future Phase III trial would require the intervention to be modified to include provision of group and individual peer mentoring; internal management of the project, with support from an external agency such as a charity or the voluntary sector; funds to cover LA research costs, including the appointment of a dedicated project co-ordinator; a reduction in the lower age for mentee recruitment and an increase in the mentor recruitment age to 21 years; and the introduction of a more formal recruitment and support structure for mentors. CONCLUSIONS: Given the problems identified and described in mounting this intervention, a new development phase followed by a small-scale exploratory trial incorporating these changes would be necessary before proceeding to a Phase III trial. FUNDING: This project was funded by the NIHR Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 19, No. 85. See the NIHR Journals Library website for further project information.

Ordering of PCDTBT revealed by time-resolved electron paramagnetic resonance spectroscopy of its triplet excitons.

Time-resolved electron paramagnetic resonance (TREPR) spectroscopy is shown to be a powerful tool to characterize triplet excitons of conjugated polymers. The resulting spectra are highly sensitive to the orientation of the molecule. In thin films cast on PET film, the molecules' orientation with respect to the surface plane can be determined, providing access to sample morphology on a microscopic scale. Surprisingly, the conjugated polymer investigated here, a promising material for organic photovoltaics, exhibits ordering even in bulk samples. Orientation effects may significantly influence the efficiency of solar cells, thus rendering proper control of sample morphology highly important.

Challenges to undertaking randomised trials with looked after children in social care settings.

BACKGROUND: Randomised controlled trials (RCTs) are widely viewed as the gold standard for assessing effectiveness in health research; however many researchers and practitioners believe that RCTs are inappropriate and un-doable in social care settings, particularly in relation to looked after children. The aim of this article is to describe the challenges faced in conducting a pilot study and phase II RCT of a peer mentoring intervention to reduce teenage pregnancy in looked after children in a social care setting. METHODS: Interviews were undertaken with social care professionals and looked after children, and a survey conducted with looked after children, to establish the feasibility and acceptability of the intervention and research design. RESULTS: Barriers to recruitment and in managing the intervention were identified, including social workers acting as informal gatekeepers; social workers concerns and misconceptions about the recruitment criteria and the need for and purpose of randomisation; resource limitations, which made it difficult to prioritise research over other demands on their time and difficulties in engaging and retaining looked after children in the study. CONCLUSIONS: The relative absence of a research infrastructure and culture in social care and the lack of research support funding available for social care agencies, compared to health organisations, has implications for increasing evidence-based practice in social care settings, particularly in this very vulnerable group of young people.

Multicenter experience in hematopoietic stem cell transplantation for serious complications of common variable immunodeficiency.

BACKGROUND: Common variable immunodeficiency (CVID) is usually well controlled with immunoglobulin substitution and immunomodulatory drugs. A subgroup of patients has a complicated disease course with high mortality. For these patients, investigation of more invasive, potentially curative treatments, such as allogeneic hematopoietic stem cell transplantation (HSCT), is warranted. OBJECTIVE: We sought to define the outcomes of HSCT for patients with CVID. METHODS: Retrospective data were collected from 14 centers worldwide on patients with CVID receiving HSCT between 1993 and 2012. RESULTS: Twenty-five patients with CVID, which was defined according to international criteria, aged 8 to 50 years at the time of transplantation were included in the study. The indication for HSCT was immunologic dysregulation in the majority of patients. The overall survival rate was 48%, and the survival rate for patients undergoing transplantation for lymphoma was 83%. The major causes of death were treatment-refractory graft-versus-host disease accompanied by poor immune reconstitution and infectious complications. Immunoglobulin substitution was stopped in 50% of surviving patients. In 92% of surviving patients, the condition constituting the indication for HSCT resolved. CONCLUSION: This multicenter study demonstrated that HSCT in patients with CVID was beneficial in most surviving patients; however, there was a high mortality associated with the procedure. Therefore this therapeutic approach should only be considered in carefully selected patients in whom there has been extensive characterization of the immunologic and/or genetic defect underlying the CVID diagnosis. Criteria for patient selection, refinement of the transplantation protocol, and timing are needed for an improved outcome.

Non-therapist identification of falling hazards in older adult homes using digital photography.

Evaluation and removal of home hazards is an invaluable method for preventing in-home falls and preserving independent living. Current processes for conducting home hazard assessments are impractical from a whole population standpoint given the substantial resources required for implementation. Digital photography offers an opportunity to remotely evaluate an environment for falling hazards. However, reliability of this method has only been tested under the direction of skilled therapists. Ten community dwelling adults over the age of 65 were recruited from local primary care practices between July, 2009 and February, 2010. In-home (IH) assessments were completed immediately after a photographer, blinded to the assessment form, took digital photographs (DP) of the participant home. A different non-therapist assessor then reviewed the photographs and completed a second assessment of the home. Kappa statistic was used to analyze the reliability between the two independent assessments. Home assessments completed by a non-therapist using digital photographs had a substantial agreement (Kappa = 0.61, p < 0.001) with in-home assessments completed by another non-therapist. Additionally, the DP assessments agreed with the IH assessments on the presence or absence of items 96.8% of the time. This study showed that non-therapists can reliably conduct home hazard evaluations using digital photographs.

A group-based brief intervention for surgery patients with high-risk substance use.

OBJECTIVE: This study examined the feasibility and efficacy of a psychosocial intervention to address high-risk substance use in patients scheduled for elective surgery. METHOD: A group-format intervention, based on motivational interviewing principles, was provided prior to elective surgery to 107 participants with at-risk substance use, identified using the Alcohol Use Disorders Identification Test - Condensed (AUDIT-C) and self-report of illicit drug use. Patient satisfaction was assessed with an anonymous survey. Within-subject comparisons of substance use at baseline and at a postoperative follow-up evaluation were conducted. A control group of 67 surgery patients reporting high-risk substance use completed baseline assessments and received usual care. Medical outcomes and measures of utilization were compared between groups. RESULTS: Patient satisfaction with the brief intervention was high. A paired t test comparing average pre- and post-AUDIT-C scores showed significant reduction in substance use postsurgery (t = 9.94, P = .000), and participants reported intention to maintain reduced substance use levels. Between-group analyses revealed no significant differences in medical complications or utilization. CONCLUSION: Findings suggest that a group-based intervention for substance use disorder can be implemented as part of preoperative care and may contribute to decreased substance use prior to and following surgery. Further work is needed to identify methods to reduce adverse medical outcomes in surgical patients.

The first year: employment patterns and job perceptions of nursing assistants in a rural setting.

AIM: The aim of this study was to follow rural certified nursing assistants (CNAs) (n=123) in the United States for 1 year post-training to identify retention and turnover issues in the long-term care (LTC) setting by exploring the CNAs' perceptions of the LTC work experience. BACKGROUND: Turnover among CNAs impacts the quality of care, imposes a financial burden on facilities and taxpayers, and creates increased stress and workloads on those who remain. METHOD: A longitudinal survey design was used to track individuals completing CNA training for 1 year. RESULTS: At 1 year post-training, 53.7% of respondents currently worked in LTC, 30.9% worked in LTC and left, and the remaining 15.4% never worked in LTC. CONCLUSION: While the training site does not appear to impact retention, the first 6 months of employment appear critical. The CNAs cited pay as a reason for leaving LTC, but better pay did not characterize the jobs taken by the CNAs who left. Implications for nursing management. This study highlights the importance of the first 6 months of employment to retention and provides practical information for nurse managers evaluating the resource-effectiveness of hosting training programmes. Additionally, the key issues influencing retention were identified and practical suggestions for nurse managers to improve retention are provided.

Interexpert agreement on diagnosis of bacteriuria and urinary tract infection in hospitalized older adults.

CONTEXT: Although bacteriuria with acute coexisting illness is common in hospitalized older adults, distinguishing it from urinary tract infection (UTI) can be challenging. OBJECTIVES: To examine the rate of agreement between two geriatricians in distinguishing UTI from asymptomatic bacteriuria (ASB). To analyze the incidence of associated acute comorbidities and determine if an association exists between clinical manifestations and bacteriuria status on acute hospital admission. METHODS: Two physicians conducted a retrospective analysis of 296 inpatient records, including 142 records from age- and condition-matched nonbacteriuria control subjects. Using consensus criteria to diagnose UTI vs ASB, these independent experts evaluated inpatient records, including admission and discharge diagnoses as well as urinalysis results. A kappa statistic was used to determine reviewer agreement. Risk assessment was measured by odds ratio with a 95% confidence interval. RESULTS: Expert agreement for the diagnosis of UTI and ASB was 98% and 44%, respectively. Agreement was reached at a level greater than chance (z=6.74, P<.001, kappa=0.49). In the 30 cases where interexpert agreement was not reached, half of the subjects had acute pulmonary disease. Symptom crossover for this comorbid condition is the likely cause for lack of diagnostic agreement. Among other conditions observed, delirium was most common in UTI subjects. CONCLUSION: Limited interexpert agreement seemed to result from difficulty in diagnosing patients who had no local symptoms but acute comorbid conditions with potential symptom crossover. Among the conditions observed in our sample population, delirium was most closely associated with UTI.

Technology, job satisfaction, and retention: rural mental health practitioners.

CONTEXT: Job satisfaction as it relates to retention of mental health professionals is a major problem in rural areas. Several authors have suggested that technology can positively influence job satisfaction and thus improve retention. OBJECTIVES: This study examined technology use and technology expertise in relationship to job satisfaction. It is based on a theoretical framework that asserts as technology use increases, communication among providers and access to educational and consultative resources increase as well, resulting in a boost in professional support and a reduction in isolation. METHODS: Surveys were sent to 320 providers in rural southeast Ohio; 163 returned usable surveys. FINDINGS: There was a statistically significant relationship between the combination of technology use and expertise and job satisfaction. Use alone, however, was not significant. Despite the fact that over 90% of respondents had access to both a computer and the Internet, just 45% used technology to communicate with peers and nearly 96% indicated that they never or rarely used the Internet for educational programs. CONCLUSIONS: The results challenge the assertion that technology plays a major role in job satisfaction and rural retention since access and perceived expertise did not guarantee technology usage. Decisions to stay or leave a rural practice involve a complex array of factors. Technology, with its ability to link providers to resources outside the geographic bounds of an individual's practice, may play a role, but since its adoption can be costly in both time and money, future studies need to determine its place in the retention model.

Recruiting and retaining mental health professionals to rural communities: an interdisciplinary course in Appalachia.

CONTEXT: Faculty from 5 disciplines (health administration, nursing, psychology, social work, and special education) collaborated to develop and teach a distance-learning course designed to encourage undergraduate and graduate students to seek mental health services employment in rural areas and to provide the skills, experience, and knowledge necessary for successful rural practice. METHODS: The primary objectives of the course, developed after thorough review of the rural retention and recruitment literature, were to (1) enhance interdisciplinary team skills, (2) employ technology as a tool for mental health practitioners, and (3) enhance student understanding of Appalachian culture and rural mental health. Didactic instruction emphasized Appalachian culture, rural mental health, teamwork and communication, professional ethics, and technology. Students were introduced to videoconferencing, asynchronous and synchronous communication, and Internet search tools. Working in teams of 3 or 4, students grappled with professional and cultural issues plus team process as they worked through a hypothetical case of a sexually abused youngster. The course required participants to engage in a nontraditional manner by immersing students in Web-based teams. FINDINGS: Student evaluations suggested that teaching facts or "content" about rural mental health and Appalachian culture was much easier than the "process" of using new technologies or working in teams. CONCLUSIONS: Given that the delivery of mental health care demands collaboration and teamwork and that rural practice relies increasingly more on the use of technology, our experience suggests that more team-based, technology-driven courses are needed to better prepare students for clinical practice.