Oscillatory oblique stagnation-point flow toward a plane wall

Two-dimensional oscillatory oblique stagnation-point flow toward a plane wall is investigated. The problem is a eneralisation of the steady oblique stagnation-point flow examined by previous workers. Far from the wall, the flow is composed of an irrotational orthogonal stagnation-point flow with a time-periodic strength, a simple shear flow of constant vorticity, and a time-periodic uniform stream. An exact solution of the Navier-Stokes equations is sought for which the flow streamfunction depends linearly on the coordinate parallel to the wall. The problem formulation reduces to a coupled pair of partial differential equations in time and one spatial variable. The first equation describes the oscillatory orthogonal stagnation-point flow discussed by previous workers. The second equation, which couples to the first, describes the oblique component of the flow. A description of the flow velocity field, the instantaneous streamlines, and the particle paths is sought through numerical solutions of the governing equations and via asymptotic analysis

Kinematically Complete Experiment on Single Ionization in 75-keV P+He Collisions

We have measured and calculated fully differential single-ionization cross sections for the complete three-dimensional space in 75 keV p+He collisions. Several signatures of the projectile-residual-target-ion interaction, some of which are not observable for fast projectiles and for electron impact, are revealed. Some of these features are qualitatively reproduced by our calculations if this interaction is accounted for. However, overall the agreement between theory and experiment is not very good. Thus, our understanding of effects caused by the projectile-residual-target-ion interaction appears to be rather incomplete

Projectile-Residual-Target-Ion Scattering After Single Ionization of Helium by Slow Proton Impact

We have measured fully differential single ionization cross sections for 75 keV p+He collisions. At this relatively small projectile velocity, signatures of the projectile-residual-target-ion interaction, which are not observable for fast projectiles and for electron impact, are revealed rather sensitively. In fact, this interaction appears to be more important than the postcollision interaction, which so far was assumed to be the most important factor in higher-order effects for slow ion impact. These features are not well reproduced by our three-distorted-wave calculations

Resource implications of adopting a restrictive neonatal blood transfusion policy

Background. Blood transfusions (BTFs) are not without risk and pose a significant financial burden on resource-limited services. In line with current international evidence, the nursery at Groote Schuur Hospital (GSH), Cape Town, South Africa, introduced a restrictive BTF protocol to minimise transfusions and manage costs.Objective. To determine whether adopting a restrictive BTF policy results in fewer transfusions. Methods. Data were retrospectively collected on all infants who received BTFs in the GSH nursery over a 6-month period following adoption of a restrictive BTF policy in 2010. BTF figures for a similar time period before the restrictive policy, during 2008, were obtained for comparison.Results. After introduction of the restrictive BTF policy, 42 of 1 097 infants admitted (3.8%) received a total of 64 BTFs. In comparison, 102 of a total of 940 infants (10.9%) admitted during a period of the same length before introduction of the restrictive BTF policy received a total of 121 transfusions. Comparison between the number of BTFs administered before and after the restrictive policy showed a highly statistically significant difference (p<0.001). The total cost of the blood products used in the two 6-month periods was R91 870 v. R48 640, based on current prices. Conclusions. By adopting a restrictive policy, we were able to halve the number of BTFs, reduce risks associated with transfusions, and achieve significant cost benefits. Following evidence-based guidelines results in high standards of care, while also making the most effective use of resources.

Prognostic value of p53 gene mutations in a large series of node- negative breast cancer patients

The most important subgroup of breast cancer patients for which reliable prognostic factors are needed are women without axillary lymph node involvement. Although overall, these patients have a good prognosis, it is known that 20-30% will experience a recurrence of the disease. To determine the prognostic significance of P53 tumor suppressor gene mutation, specimens from 113 primary breast cancers were evaluated for the presence of P53 alterations, as detected by cDNA sequencing of the entire coding sequence of the gene. The median follow-up for patients was 105 months. P53 gene mutation was an independent prognostic marker of early relapse and death. Our results suggest that P53 gene mutations could be an important factor to identify node-negative patients who have a poor prognosis in the absence of adjuvant therapy. Prospective studies should be designed to determine which therapy should be performed in this subgroup of patients

Alterations in Retinal Microvascular Geometry in Young Type 1 Diabetes

OBJECTIVE - To describe retinal microvascular geometric parameters in young patients with type 1 diabetes. RESEARCH DESIGN AND METHODS - Patients with type 1 diabetes (aged 12-20 years) had clinical assessments and retinal photography following standardized protocol at a tertiary-care hospital in Sydney. Retinal microvascular geometry, including arteriolar and venular tortuosity, branching angles, optimality deviation, and length-to-diameter ratio (LDR), were measured from digitized photographs. Associations of these geometric characteristics with diabetes duration, A1C level, systolic blood pressure (SBP), and other risk factors were assessed. RESULTS - Of 1,159 patients enrolled, 944 (81.4%) had gradable photographs and 170 (14.7%) had retinopathy. Older age was associated with decreased arteriolar (P = 0.024) and venular (P = 0.002) tortuosity, and female subjects had larger arteriolar branching angle than male subjects (P = 0.03). After adjusting for age and sex, longer diabetes duration was associated with larger arteriolar branching angle (P ≤ 0.001) and increased arteriolar optimality deviation (P = 0.018), higher A1C was associated with increased arteriolar tortuosity (>8.5 vs. ≤8.5%, P = 0.008), higher SBP was associated with decreased arteriolar LDR (P = 0.002), and higher total cholesterol levels were associated with increased arteriolar LDR (P = 0.044) and decreased venular optimality deviation (P = 0.044). These associations remained after controlling for A1C, retinal vessel caliber, and retinopathy status and were seen in subjects without retinopathy. CONCLUSIONS - Key diabetes-related factors affect retinal microvascular geometry in young type 1 diabetes, even in those without evidence of retinopathy. These early retinal alterations may be markers of diabetes microvascular complications. © 2010 by the American Diabetes Association.link_to_OA_fulltex

Does dissemination extend beyond publication: a survey of a cross section of public funded research in the UK

Background: In the UK, most funding bodies now expect a commitment or effort on the part of grant holders to disseminate the findings of their research. The emphasis is on ensuring that publicly funded research is made available, can be used to support decision making, and ultimately improve the quality and delivery of healthcare provided. In this study, we aimed to describe the dissemination practices and impacts of applied and public health researchers working across the UK.Methods: We conducted a survey of 485 UK-based principal investigators of publicly funded applied and public health research. Participants were contacted by email and invited to complete an online questionnaire via an embedded URL. Gift vouchers were given to all participants who completed the questionnaire. Four reminder emails were sent out to non-respondents at one, two, three, and four weeks; a fifth postal reminder was also undertaken.Results: A total of 243/485 (50%) questionnaires were returned (232 completed, 11 declining to participate). Most researchers recognise the importance of and appear committed to research dissemination. However, most dissemination activity beyond the publishing of academic papers appears to be undertaken an ad hoc fashion. There is some evidence that access to dissemination advice and support may facilitate more policy interactions; though access to such resources is lacking at an institutional level, and advice from funders can be variable. Although a minority of respondents routinely record details about the impact of their research, when asked about impact in relation to specific research projects most were able to provide simple narrative descriptions.Conclusions: Researchers recognise the importance of and appear committed to disseminating the findings of their work. Although researchers are focussed on academic publication, a range of dissemination activities are being applied albeit in an ad hoc fashion. However, what constitutes effective dissemination (in terms of impact and return on investment) remains unclear. Researchers need greater and clearer guidance on how best to plan, resource, and facilitate their dissemination activities

Clinical experience in T cell deficient patients

T cell disorders have been poorly understood until recently. Lack of knowledge of underlying molecular mechanisms together with incomplete data on long term outcome have made it difficult to assess prognosis and give the most effective treatment. Rapid progress in defining molecular defects, improved supportive care and much improved results from hematopoietic stem cell transplantation (HSCT) now mean that curative treatment is possible for many patients. However, this depends on prompt recognition, accurate diagnosis and careful treatment planning

The international Perinatal Outcomes in the Pandemic (iPOP) study: protocol

Preterm birth is the leading cause of infant death worldwide, but the causes of preterm birth are largely unknown. During the early COVID-19 lockdowns, dramatic reductions in preterm birth were reported; however, these trends may be offset by increases in stillbirth rates. It is important to study these trends globally as the pandemic continues, and to understand the underlying cause(s). Lockdowns have dramatically impacted maternal workload, access to healthcare, hygiene practices, and air pollution - all of which could impact perinatal outcomes and might affect pregnant women differently in different regions of the world. In the international Perinatal Outcomes in the Pandemic (iPOP) Study, we will seize the unique opportunity offered by the COVID-19 pandemic to answer urgent questions about perinatal health. In the first two study phases, we will use population-based aggregate data and standardized outcome definitions to: 1) Determine rates of preterm birth, low birth weight, and stillbirth and describe changes during lockdowns; and assess if these changes are consistent globally, or differ by region and income setting, 2) Determine if the magnitude of changes in adverse perinatal outcomes during lockdown are modified by regional differences in COVID-19 infection rates, lockdown stringency, adherence to lockdown measures, air quality, or other social and economic markers, obtained from publicly available datasets. We will undertake an interrupted time series analysis covering births from January 2015 through July 2020. The iPOP Study will involve at least 121 researchers in 37 countries, including obstetricians, neonatologists, epidemiologists, public health researchers, environmental scientists, and policymakers. We will leverage the most disruptive and widespread “natural experiment” of our lifetime to make rapid discoveries about preterm birth. Whether the COVID-19 pandemic is worsening or unexpectedly improving perinatal outcomes, our research will provide critical new information to shape prenatal care strategies throughout (and well beyond) the pandemic