Photovoltaic Properties of p-Doped GaAs Nanowire Arrays Grown on n-Type GaAs(111)B Substrate

We report on the molecular beam epitaxy growth of Au-assisted GaAs p-type-doped NW arrays on the n-type GaAs(111)B substrate and their photovoltaic properties. The samples are grown at different substrate temperature within the range from 520 to 580 °C. It is shown that the dependence of conversion efficiency on the substrate temperature has a maximum at the substrate temperature of 550 °C. For the best sample, the conversion efficiency of 1.65% and the fill factor of 25% are obtained

The effects of clinical task interruptions on subsequent performance of a medication pre-administration task

There is a surge of research exploring the role of task interruptions in the manifestation of primary task errors both in controlled experimental settings, and safety critical workplaces such as healthcare. Despite such research providing valuable insights into the disruptive properties of task interruption, and, the importance of considering the likely disruptive consequences of clinical task interruptions in healthcare environments, there is an urgent need for an approach that best mimics complex working environments such as healthcare, whilst allowing better control over experimental variables with minimal constraints. We propose that this can be achieved with ecologically sensitive experimental tasks designed to have high levels of experimental control so that theoretical as well as practical parameters and factors can be tested. We developed a theoretically and ecologically informed procedural memory-based task - the CAMROSE Medication Pre-Administration Task. Results revealed significantly more sequence errors were made on low, moderate and high complex conditions compared to no interruption condition. There was no significant difference in non-sequence errors. Findings reveal the importance of developing ecologically valid tasks to explore non-observable characteristics of clinical task interruptions. Both theoretical and possible practical implications are discussed

Performance of a combined optical coherence tomography and scanning laser ophthalmoscope with adaptive optics for human retinal imaging applications

We describe the design and performance of a recently implemented retinal imaging system for the human eye that combines adaptive optics (AO) with spectral domain optical coherence tomography (OCT) and scanning laser ophthalmoscopy (SLO). The AO-OCT-SLO system simultaneously acquires SLO frames and OCT B-scans at 60 Hz with an OCT volume acquisition scan rate of 0.24 Hz. The SLO images are used to correct for eye motion during the registration of OCT B-scans. Key optical design considerations are discussed including: minimizing system aberrations through the use of off-axis relay telescopes; choice of telescope magnification based on pupil plane requirements and restrictions; and the use of dichroic beam splitters to separate and re-combine OCT and SLO beams around the nonshared horizontal scanning mirrors. We include an analysis of closed-loop AO correction on a model eye and compare these findings with system performance in vivo. The 2D and 3D OCT scans included in this work demonstrate the ability of this system to laterally and axially resolve individual cone photoreceptors, while the corresponding SLO images show the en face mosaics at the photoreceptor layer showing rods and cones. Images from both healthy and diseased retina are presented

In Vivo Serial MR Imaging of Magnetically Labeled Endothelial Progenitor Cells Homing to the Endothelium Injured Artery in Mice

Background: Emerging evidence of histopathological analyses suggests that endothelial progenitor cells (EPCs) play an important role in vascular diseases. Neointimal hyperplasia can be reduced by intravenous transfusion of EPCs after vascular injury in mice. Therefore, it would be advantageous to develop an in vivo technique that can explore the temporal and spatial migration of EPCs homing to the damaged endothelium noninvasively. Methodology/Principal Findings: The left carotid common artery (LCCA) was injured by removal of endothelium with a flexible wire in Kunming mice. EPCs were collected by in vitro culture of spleen-derived mouse mononuclear cells (MNCs). EPCs labeling was carried out in vitro using Fe2O3-poly-L-lysine (Fe2O3-PLL). In vivo serial MR imaging was performed to follow-up the injured artery at different time points after intravenous transfusion of EPCs. Vessel wall areas of injured artery were computed on T2WI. Larger MR signal voids of vessel wall on T2WI was revealed in all 6 mice of the labeled EPC transfusion group 15 days after LCCA injury, and it was found only in 1 mouse in the unlabeled EPC transfusion group (p = 0.015). Quantitative analyses of vessel wall areas on T2WI showed that the vessel wall areas of labeled EPC transfusion group were less than those of unlabeled EPC transfusion group and control group fifteen days after artery injury (p,0.05). Histopathological analyses confirmed accumulation and distribution of transfused EPCs at the injury site of LCCA. Conclusions/Significance: These data indicate that MR imaging might be used as an in vivo method for the tracking of EPC

The communication of a secondary care diagnosis of autoimmune hepatitis to primary care practitioners: a population-based study

Background Autoimmune Hepatitis is a chronic liver disease which affects young people and can result in liver failure leading to death or transplantation yet there is a lack of information on the incidence and prevalence of this disease and its natural history in the UK. A means of obtaining this information is via the use of clinical databases formed of electronic primary care records. How reliably the diagnosis is coded in such records is however unknown. The aim of this study therefore was to assess the proportion of consultant hepatologist diagnoses of Autoimmune Hepatitis which were accurately recorded in General Practice computerised records. Methods Our study population were patients with Autoimmune Hepatitis diagnosed by consultant hepatologists in the Queens Medical Centre, Nottingham University Hospitals (UK) between 2004 and 2009. We wrote to the general practitioners of these patients to obtain the percentage of patients who had a valid READ code specific for Autoimmune Hepatitis. Results We examined the electronic records of 51 patients who had biopsy evidence and a possible diagnosis of Autoimmune Hepatitis. Forty two of these patients had a confirmed clinical diagnosis of Autoimmune Hepatitis by a consultant hepatologist: we contacted the General Practitioners of these patients obtaining a response rate of 90.5% (39/42 GPs). 37/39 of these GPs responded with coding information and 89% of these patients (33/37) used Read code J638.00 (Autoimmune Hepatitis) to record a diagnosis. Conclusions The diagnosis of Autoimmune Hepatitis made by a Consultant Hepatologist is accurately communicated to and electronically recorded by primary care in the UK. As a large proportion of cases of Autoimmune Hepatitis are recorded in primary care, this minimises the risk of introducing selection bias and therefore selecting cases using these data will be a valid method of conducting population based studies on Autoimmune Hepatitis

Responsibility for managing musculoskeletal disorders – A cross-sectional postal survey of attitudes

Background: Musculoskeletal disorders are a major burden on individuals, health systems and social care systems and rehabilitation efforts in these disorders are considerable. Self-care is often considered a cost effective treatment alternative owing to limited health care resources. But what are the expectations and attitudes in this question in the general population? The purpose of this study was to describe general attitudes to responsibility for the management of musculoskeletal disorders and to explore associations between attitudes and background variables. Methods: A cross-sectional, postal questionnaire survey was carried out with a random sample of a general adult Swedish population of 1770 persons. Sixty-one percent (n = 1082) responded to the questionnaire and was included for the description of general attitudes towards responsibility for the management of musculoskeletal disorders. For the further analyses of associations to background variables 683–693 individuals could be included. Attitudes were measured by the "Attitudes regarding Responsibility for Musculoskeletal disorders" (ARM) instrument, where responsibility is attributed on four dimensions; to myself, as being out of my hands, to employers or to (medical) professionals. Multiple logistic regression was used to explore associations between attitudes to musculoskeletal disorders and the background variables age, sex, education, physical activity, presence of musculoskeletal disorders, sick leave and whether the person had visited a care provider. Results: A majority of participants had internal views, i.e. showed an attitude of taking personal responsibility for musculoskeletal disorders, and did not place responsibility for the management out of their own hands or to employers. However, attributing shared responsibility between self and medical professionals was also found.The main associations found between attitude towards responsibility for musculoskeletal disorders and investigated background variables were that physical inactivity (OR 2.92–9.20), musculoskeletal disorder related sick leave (OR 2.31–3.07) and no education beyond the compulsory level (OR 3.12–4.76) increased the odds of attributing responsibility externally, i.e placing responsibility on someone or something else.Conclusion: Respondents in this study mainly saw themselves as responsible for managing musculoskeletal disorders. The associated background variables refined this finding and one conclusion is that, to optimise outcome when planning the prevention, treatment and management of these disorders, people's attitudes should be taken into account

Expectations, perceptions, and physiotherapy predict prolonged sick leave in subacute low back pain

<p>Abstract</p> <p>Background</p> <p>Brief intervention programs for subacute low back pain (LBP) result in significant reduction of sick leave compared to treatment as usual. Although effective, a substantial proportion of the patients do not return to work. This study investigates predictors of return to work in LBP patients participating in a randomized controlled trial comparing a brief intervention program (BI) with BI and physical exercise.</p> <p>Methods</p> <p>Predictors for not returning to work was examined in 246 patients sick listed 8-12 weeks for low back pain. The patients had participated in a randomized controlled trial, with BI (n = 122) and BI + physical exercise (n = 124). There were no significant differences between the two intervention groups on return to work. The groups were therefore merged in the analyses of predictors. Multiple logistic regression analysis was used to identify predictors for non return to work at 3, 12, and 24 months of follow-up.</p> <p>Results</p> <p>At 3 months of follow-up, the strongest predictors for not returning to work were pain intensity while resting (OR = 5.6; CI = 1.7-19), the perception of constant back strain when working (OR = 4.1; CI = 1.5-12), negative expectations for return to work (OR = 4.2; CI = 1.7-10), and having been to a physiotherapist prior to participation in the trial (OR = 3.3; CI = 1.3-8.3). At 12 months, perceived reduced ability to walk far due to the complaints (OR = 2.6; CI = 1.3-5.4), pain during activities (OR = 2.4; CI = 1.1-5.1), and having been to a physiotherapist prior to participation in the trial (OR = 2.1; CI = 1.1-4.3) were the strongest predictors for non return to work. At 24 months age below 41 years (OR = 2.9; CI = 1.4-6.0) was the only significant predictor for non return to work.</p> <p>Conclusion</p> <p>It appears that return to work is highly dependant on individual and cognitive factors. Patients not returning to work after the interventions were characterized by negative expectations, perceptions about pain and disability, and previous physiotherapy treatment. This is the first study reporting that previous treatment by physiotherapists is a risk factor for long-term sick leave. This has not been reported before and is an interesting finding that deserves more scrutiny.</p

Infrared composition of the Large Magellanic Cloud

The evolution of galaxies and the history of star formation in the Universe are among the most important topics in today's astrophysics. Especially, the role of small, irregular galaxies in the star-formation history of the Universe is not yet clear. Using the data from the AKARI IRC survey of the Large Magellanic Cloud at 3.2, 7, 11, 15, and 24 {\mu}m wavelengths, i.e., at the mid- and near-infrared, we have constructed a multiwavelength catalog containing data from a cross-correlation with a number of other databases at different wavelengths. We present the separation of different classes of stars in the LMC in color-color, and color-magnitude, diagrams, and analyze their contribution to the total LMC flux, related to point sources at different infrared wavelengths

Emergent complex neural dynamics

A large repertoire of spatiotemporal activity patterns in the brain is the basis for adaptive behaviour. Understanding the mechanism by which the brain's hundred billion neurons and hundred trillion synapses manage to produce such a range of cortical configurations in a flexible manner remains a fundamental problem in neuroscience. One plausible solution is the involvement of universal mechanisms of emergent complex phenomena evident in dynamical systems poised near a critical point of a second-order phase transition. We review recent theoretical and empirical results supporting the notion that the brain is naturally poised near criticality, as well as its implications for better understanding of the brain

Differences in pregnancy outcomes in donor egg frozen embryo transfer (FET) cycles following preimplantation genetic screening (PGS): a single center retrospective study

PURPOSE: This study aims to test the hypothesis, in a single-center retrospective analysis, that live birth rates are significantly different when utilizing preimplantation genetic screening (PGS) compared to not utilizing PGS in frozen–thawed embryo transfers in our patients that use eggs from young, anonymous donors. The question therefore arises of whether PGS is an appropriate intervention for donor egg cycles. METHODS: Live birth rates per cycle and live birth rates per embryo transferred after 398 frozen embryo transfer (FET) cycles were examined from patients who elected to have PGS compared to those who did not. Blastocysts derived from donor eggs underwent trophectoderm biopsy and were tested for aneuploidy using array comparative genomic hybridization (aCGH) or next-generation sequencing (NGS), then vitrified for future use (test) or were vitrified untested (control). Embryos were subsequently warmed and transferred into a recipient or gestational carrier uterus. Data was analyzed separately for single embryo transfer (SET), double embryo transfer (DET), and for own recipient uterus and gestational carrier (GC) uterus recipients. RESULTS: Rates of implantation of embryos leading to a live birth were significantly higher in the PGS groups transferring two embryos (DET) compared to the no PGS group (GC, 72 vs. 56 %; own uterus, 60 vs. 36 %). The live birth implantation rate in the own uterus group for SET was higher in the PGS group compared to the control (58 vs. 36 %), and this almost reached significance but the live birth implantation rate for the SET GC group remained the same for both tested and untested embryos. Live births per cycle were nominally higher in the PGS GC DET and own uterus SET and DET groups compared to the non-PGS embryo transfers. These differences almost reached significance. The live birth rate per cycle in the SET GC group was almost identical. CONCLUSIONS: Significant differences were noted only for DET; however, benefits need to be balanced against risks associated with multiple pregnancies. Results observed for SET need to be confirmed on larger series and with randomized cohorts