Facile access to functionalized chiral secondary benzylic boronic esters via catalytic asymmetric hydroboration

Allylic and homoallylic phosphonates bearing an aryl or heteroaryl substituent at the γ- or δ-position undergo rhodium-catalyzed asymmetric hydroboration by pinacolborane to give functionalized chiral secondary benzylic boronic esters in yields up to 86% and enantiomer ratios up to 99 : 1. Compared to minimally-functionalized terminal and 1,1-disubstituted vinyl arenes, there are relatively few reports of efficient catalytic asymmetric hydroboration (CAHB) of more highly functionalized internal alkenes. Phosphonate substrates bearing a variety of common heterocyclic ring systems, including furan, indole, pyrrole and thiophene derivatives, as well as those bearing basic nitrogen substituents (e.g., morpholine and pyrazine) are tolerated, although donor substituents positioned in close proximity of the alkene can influence the course of the reaction. Stereoisomeric (E)- and (Z)-substrates afford the same major enantiomer of the borated product. Deuterium-labelling studies reveal that rapid (Z)- to (E)-alkene isomerization accounts for the observed (E/Z)-stereoconvergence during CAHB. The synthetic utility of the chiral boronic ester products is illustrated by stereospecific C–B bond transformations including stereoretentive electrophile promoted 1,2-B-to-C migrations, stereoinvertive SE2 reactions of boron-ate complexes with electrophiles, and stereoretentive palladium- and rhodium-catalyzed cross-coupling protocols

Organoids and bioengineered intestinal models: Potential solutions to the Cryptosporidium culturing dilemma

Cryptosporidium is a major cause of severe diarrhea-related disease in children in developing countries, but currently no vaccine or effective treatment exists for those who are most at risk of serious illness. This is partly due to the lack of in vitro culturing methods that are able to support the entire Cryptosporidium life cycle, which has led to research in Cryptosporidium biology lagging behind other protozoan parasites. In vivo models such as gnotobiotic piglets are complex, and standard in vitro culturing methods in transformed cell lines, such as HCT-8 cells, have not been able to fully support fertilization occurring in vitro. Additionally, the Cryptosporidium life cycle has also been reported to occur in the absence of host cells. Recently developed bioengineered intestinal models, however, have shown more promising results and are able to reproduce a whole cycle of infectivity in one model system. This review evaluates the recent advances in Cryptosporidium culturing techniques and proposes future directions for research that may build upon these successes

Functional Outcomes of Thoracolumbar Junction Spine Fractures

Introduction. Few studies have evaluated the functionaloutcomes of traumatic thoracic and lumbar vertebral bodyfractures. This study evaluated the functional and clinicaloutcomes of patients, who sustained a fracture to thethoracolumbar area of the spine (T10 to L2 region), with≥ 25° kyphosis versus those with less kyphotic curvature. Methods. The trauma registry records of two level 1 traumacenters using ICD-9 codes for fracture to the thoracolumbarjuncture (T10 to L2 region) were reviewed. Kyphosis anglewas measured on the standing lateral thoracolumbar (T1 -L5) radiograph at initial trauma and at clinical follow-up.Functional outcome questionnaires, including the OswestryDisability Questionnaire (ODQ), the Roland Morris DisabilityQuestionnaire (RMDQ), and the Nottingham Health Profile(NHP), were evaluated at clinical follow-up. Work statusand medication used after trauma also were recorded. Results. A total of 38 patients met the inclusive criteria. Seventeenpatients (45%) had ≥ 25° kyphosis and 21 patients (55%)had < 25° kyphosis at follow-up. These two groups were similarbased on sex and age. Based on the ODQ Score, the RMDQScore, and the NHP, no statistically significant differenceswere detected between the two groups in regards to energy,pain, mobility, emotional reaction, social isolation, and sleep. Conclusions. Patients who sustained a fracture to the thoracolumbararea of the spine with ≥ 25° kyphosis do notreport worse clinical outcomes. When using the kyphosisangle as an indication for surgery, it should be used withcaution and not exclusively. KS J Med 2017;10(2):30-34

Research on the experience of staff with disabilities within the NHS workforce

NHS England has commissioned a primarily quantitative research project, focusing on the experiences of staff with disabilities working within the NHS, drawing upon two national data sets: • The 2014 NHS staff survey, completed by 255,000 staff, reporting their experiences of working in the NHS • The Electronic Staff Record (ESR), comprising data on the entire NHS workforce, gathered for workforce planning, personnel and wage payment purposes. The research tender required a focus on the following issues: a. What is staff with disabilities’ representation at all levels of the NHS and covering different types of disability? b. Why is there a disparity between the proportion of staff who declare a disability on the Electronic Staff Record System and of those who declare a disability on the anonymous NHS staff survey? c. How well are staff supported who become disabled during the course of their employment? Is there a process for recording this on the staff survey? d. What are appraisal rates for staff with disabilities compared to non-disabled staff? e. Do staff with disabilities have similar levels of access to training and development as non-disabled staff? f. How well do NHS organisations make reasonable adjustments for staff with disabilities, from the recruitment process to the end of employment? g. What difference does the ‘two ticks’ symbol make to recruitment and employment? h. What are the numbers of staff with disabilities who are the subject of employment processes and procedures, for example disciplinary and capability processes? i. What are the turn-over, retention and stability rates for staff with disabilities within the NHS? Key findings are: Staff with disabilities’ representation at all levels of the NHS and covering different types of disability Levels of reported disability are around 17% in the NHS Staff survey, and around 3% in the ESR. Neither data set allows for more specific analysis between different types or degrees of disability. The most likely reasons for the disparity between reported levels of disability are: 1. Differences in definition of disability used in the two data sets 2. Differing conditions for self-disclosure (NHS staff survey is anonymous) 3. Time of disclosure (ESR reports disability at the time of staff appointment, and is not reliably updated) Differences in quality of support between staff with and without disabilities There was not a specific survey question that addressed this issue, but it was possible to identify a number of questions that the report argues can be taken as acting as ‘indicators’: What are the levels of bullying and harassment?; How far do staff feel ‘Pressure to work when feeling unwell’?; Do staff feel their organisation acts fairly with regard to career progression? Relative to non-disabled staff, staff with disabilities felt more bullied, in particular from their managers (12 percentage points more); more pressure to work when feeling unwell (11 percentage points more); and less confident that their organisation acts fairly with regard to career progression (8 points difference). The report concludes that, relative to non-disabled staff, staff with disabilities rate themselves as substantially less well supported. Appraisal rates Rates of appraisal between staff with and without disabilities were broadly comparable. However there were substantial differences in how the value of appraisal was rated. Staff with disabilities are less satisfied with the effects of their appraisal. 7 percentage points fewer felt that appraisals improved their performance. Moreover, 9 percentage points more disabled staff report that their appraisal left them feeling that their work is not valued by their organisation. Experience of training The NHS staff survey indicates that most staff had training within the last 12 months and only 5 - 25% staff received no training in each specified topic. There is very little disparity between disabled and non-disabled staff in the proportion not receiving training in any of the topics, or in their satisfaction with the training. Reasonable adjustments The NHS Staff survey asks if ‘employer has made adequate adjustment(s) to enable you to carry on your work’. 40% respond ‘Yes’, 14% ‘No’ and 46% ‘No adjustment required’. The proportion responding ‘No’ varies substantially depending on the Trust involved, from a low of 5% to a high of 41%. The proportion also varies by ethnicity, with white British staff with disabilities expressing the lowest rate of dissatisfaction with the adjustments their employer made, while all other ethnic categories have consistently higher rates. The relatively small groups of Bangladeshi and ‘Other black background’ staff have the highest rates of dissatisfaction. Job satisfaction Staff with disabilities rate themselves as more dissatisfied with the recognition, support, responsibility and opportunities they have in their jobs, even though there is no difference in the satisfaction they report in the quality of care they give to patients. Staff with disabilities felt less recognised for their good work undertaken (8 percentage points fewer); they felt less supported by their immediate managers (5 percentage points fewer); they felt less supported by their work colleagues (3 percentage points fewer); they were more dissatisfied with the levels of responsibility they had been given (4 percentage points fewer); they felt they had less opportunity to use their skills (5 percentage points fewer); and finally, they were substantially less satisfied with their level of remuneration, and they thought they were valued less highly by their organisation for the contribution they were making (both 9 percentage points fewer). What difference does the ‘two ticks’ symbol make to recruitment and employment? The evidence from previous studies suggests that the Two Ticks award does not make a great deal of difference in terms of an organisation’s awareness of disability issues or in its capacity to address any inequalities or inadequacies in practice. We found in our study that the great majority of Trusts now have ‘Two Tick’ status. Using the NHS Jobs website, Trust websites and other evidence available online, as well as a DWP list, an estimate was made of the current ‘Two Ticks’ status of every Trust. 18 of 244 (7%) Trusts were found to not have the award. A comparison was made between Trusts with and without the ‘Two Ticks’ award of the extent to which staff who declare a disability report that their employer failed to make ‘adequate adjustments’ to enable them to carry out their work. Although in our study, there was a consistent finding that Trusts that have the ‘Two Ticks’ award have marginally higher average rates of ‘adequate adjustments’ reported by staff with disabilities, the difference is small, the number of ‘No award’ Trusts is small (just 1 in the case of Ambulance and Community Trusts) and the range among all Trusts is very large (from 5% to 41 %). Given also that the overall performance of Trusts was poor with respect to a variety of issues summarized above, such as levels of bullying and harassment, impact of appraisal etc., it would seem that ‘Two Ticks’ status achieves relatively little in terms of improved performance against these metrics

Cathode & Electromagnet Qualification Status and Power Processing Unit Development Update for the Ascendant Sub-kW Transcelestial Electric Propulsion System

A review of the component-level flight qualification efforts and power processing unit development status of the Ascendant Sub-kW Transcelestial Electric Propulsion System (ASTRAEUS) program is presented. Component-level qualification efforts were undertaken for the system’s ultra-compact heaterless LaB6 hollow cathode and electromagnets, both of which employ designs bespoke to ASTRAEUS, as they represent the highest failure risks for the thruster. Through parallel long-duration wear and ignition tests, the ASTRAEUS cathode demonstrated invariant discharge performance over more than 5000 h of operation at its maximum operating current of 4 A and demonstrated more than 25,000 ignition cycles. The ASTRAEUS electromagnets completed their environmental qualification through a demonstration of more than 1200 deep thermal cycles with no indication of coil degradation (the test articles previously completed qualification-level vibration and shock testing). ASTRAEUS’s prototype power processing unit has demonstrated more than 92% total power conversion efficiency and class-leading power density & specific power density of 4.5 W/cm3 & 1670 W/kg, respectively. The various power converters found in the ASTRAEUS power processing unit are reviewed with a focus on the methods by which such high performance was achieved

Walking the walk: a phenomenological study of long distance walking

Evidence suggests that regular walking can elicit significant psychological benefits although little evidence exists concerning long distance walking. The purpose of this study was to provide detailed accounts of the experiences of long distance walkers. Phenomenological interviews were conducted with six long distance walkers. Data were transcribed verbatim before researchers independently analyzed the transcripts. Participants reported a cumulative effect with positive feelings increasing throughout the duration of the walk. Long distance walking elicited positive emotions, reduced the effects of life-stress, and promoted an increased sense of well-being and personal growth. Results are aligned to theories and concepts from positive psychology

Self-similar Bianchi models: I. Class A models

We present a study of Bianchi class A tilted cosmological models admitting a proper homothetic vector field together with the restrictions, both at the geometrical and dynamical level, imposed by the existence of the simply transitive similarity group. The general solution of the symmetry equations and the form of the homothetic vector field are given in terms of a set of arbitrary integration constants. We apply the geometrical results for tilted perfect fluids sources and give the general Bianchi II self-similar solution and the form of the similarity vector field. In addition we show that self-similar perfect fluid Bianchi VII$_0$ models and irrotational Bianchi VI$_0$ models do not exist.Comment: 14 pages, Latex; to appear in Classical and Quantum Gravit

Emissions of biogenic volatile organic compounds and subsequent photochemical production of secondary organic aerosol in mesocosm studies of temperate and tropical plant species

Silver birch (Betula pendula) and three Southeast Asian tropical plant species (Ficus cyathistipula, Ficus benjamina and Caryota millis) from the pantropical fig and palm genera were grown in a purpose-built and environment-controlled whole-tree chamber. The volatile organic compounds emitted from these trees were characterised and fed into a linked photochemical reaction chamber where they underwent photo-oxidation under a range of controlled conditions (relative humidity or RH ~65–89%, volatile organic compound-to-NOx or VOC / NOx ~3–9 and NOx ~2 ppbV). Both the gas phase and the aerosol phase of the reaction chamber were monitored in detail using a comprehensive suite of on-line and off-line chemical and physical measurement techniques. Silver birch was found to be a high monoterpene and sesquiterpene but low isoprene emitter, and its emissions were observed to produce measurable amounts of secondary organic aerosol (SOA) via both nucleation and condensation onto pre-existing seed aerosol (YSOA 26–39%). In contrast, all three tropical species were found to be high isoprene emitters with trace emissions of monoterpenes and sesquiterpenes. In tropical plant experiments without seed aerosol there was no measurable SOA nucleation, but aerosol mass was shown to increase when seed aerosol was present. Although principally isoprene emitting, the aerosol mass produced from tropical fig was mostly consistent (i.e. in 78 out of 120 aerosol mass calculations using plausible parameter sets of various precursor specific yields) with condensation of photo-oxidation products of the minor volatile organic compounds (VOCs) co-emitted; no significant aerosol yield from condensation of isoprene oxidation products was required in the interpretations of the experimental results. This finding is in line with previous reports of organic aerosol loadings consistent with production from minor biogenic VOCs co-emitted with isoprene in principally isoprene-emitting landscapes in Southeast Asia. Moreover, in general the amount of aerosol mass produced from the emissions of the principally isoprene-emitting plants was less than would be expected from published single-VOC experiments, if co-emitted species were solely responsible for the final SOA mass. Interpretation of the results obtained from the fig data sets leaves room for a potential role for isoprene in inhibiting SOA formation under certain ambient atmospheric conditions, although instrumental and experimental constraints impose a level of caution in the interpretation of the results. Concomitant gas- and aerosol-phase composition measurements also provide a detailed overview of numerous key oxidation mechanisms at work within the systems studied, and their combined analysis provides insight into the nature of the SOA formed

The Influence of Sonographer Experience on Skeletal Muscle Image Acquisition and Analysis

The amount of experience with ultrasonography may influence measurement outcomes while images are acquired or analyzed. The purpose of this study was to identify the interrater reliability of ultrasound image acquisition and image analysis between experienced and novice sonographers and image analysts, respectively. Following a brief hands-on training session (2 h), the experienced and novice sonographers and analysts independently performed image acquisition and analyses on the biceps brachii, vastus lateralis, and medial gastrocnemius in a sample of healthy participants (n = 17). Test–retest reliability statistics were computed for muscle thickness (transverse and sagittal planes), muscle cross-sectional area, echo intensity and subcutaneous adipose tissue thickness. The results show that image analysis experience generally has a greater impact on measurement outcomes than image acquisition experience. Interrater reliability for measurements of muscle size during image acquisition was generally good–excellent (ICC2,1: 0.82–0.98), but poor–moderate for echo intensity (ICC2,1: 0.43–0.77). For image analyses, interrater reliability for measurements of muscle size for the vastus lateralis and biceps brachii was poor–moderate (ICC2,1: 0.48–0.70), but excellent for echo intensity (ICC2,1: 0.90–0.98). Our findings have important implications for laboratories and clinics where members possess varying levels of ultrasound experience