Free volume dilatation in polymers by ortho-positronium

The possibility of positronium induced free volume cavity expansion in some polymers above the glass transition temperature was investigated using experimental positron annihilation lifetime data from the literature for polydimethylsiloxane, polyisobutylene, and polybutadiene as function of temperature. The results suggest that free volume sites can expand towards an equilibrium size, determined as the equilibrium Ps-bubble size defined earlier for low-molecular-weight liquids. The expansion can be explained by the increase of molecular mobility and hence decrease of relaxation times, which at the higher temperatures approach the o-Ps lifetimes. Nanoscale viscosities were estimated using Navier-Stokes equation and were found to be several orders of magnitude lower than the macroscopic viscosity at the same temperature

N-{3-[2-(4-Fluoro­phen­oxy)eth­yl]-2,4-dioxo-1,3-diaza­spiro­[4.5]decan-7-yl}-4-meth­oxy­benzene­sulfonamide

In the title compound, C23H26FN3O6S, the two terminal aromatic rings form a dihedral angle of 49.26 (12)°. The cyclo­hexane ring adopts a chair conformation and the five-membered ring is essentially planar, with a maximum deviation from planarity of 0.0456 (19) Å. The dihedral angles between the five-membered ring and the meth­oxy­benzene and fluoro­benzene rings are 33.56 (11) and 81.94 (12)°, respectively. The crystal structure displays N—H⋯O hydrogen bonds as well as weak inter­molecular C—H⋯O inter­actions

Short-form measures of diabetes-related emotional distress: The Problem Areas in Diabetes Scale (PAID)-5 and PAID-1

Aims/hypothesis: We wanted to identify a five-item short form of the Problem Areas in Diabetes Scale and a single-item measure for rapid screening of diabetes-related emotional distress. Methods: Using an existing database of 1,153 patients with diabetes, we conducted a principal-components analysis to identify a set of five items and then conducted a reliability analysis and validity checks. From those five items, we identified the item with the strongest psychometric properties as a one-item screening tool. Results: We identified a reliable and valid short version of the Problem Areas in Diabetes Scale (PAID) comprising five of the emotional-distress questions of the full PAID items (PAID-5, with items 3, 6, 12, 16, 19). The PAID-5 has satisfactory sensitivity (94%) and specificity (89%) for recognition of diabetes-related emotional distress. We also identified a one-item screening tool, the PAID-1 (Question 12: Worrying about the future and the possibility of serious complications), which has concurrent sensitivity and specificity of about 80% for the recognition of diabetes-related emotional distress. Conclusions/ interpretation: The PAID-5 and PAID-1 appear to be psychometrically robust short-form measures of diabetes-related emotional distress.Centro de Endocrinología Experimental y Aplicad

Editor's Choice - Carotid Stenosis Treatment : Variation in International Practice Patterns

Objectives: The aim was to determine current practice for the treatment of carotid stenosis among 12 countries participating in the International Consortium of Vascular Registries (ICVR). Methods: Data from the United States Vascular Quality Initiative (VQI) and the Vascunet registry collaboration (including 10 registries in Europe and Australasia) were used. Variation in treatment modality of asymptomatic versus symptomatic patients was analysed between countries and among centres within each country. Results: Among 58,607 procedures, octogenarians represented 18% of all patients, ranging from 8% (Hungary) to 22% (New Zealand and Australia). Women represented 36%, ranging from 29% (Switzerland) to 40% (USA). The proportion of carotid artery stenting (CAS) among asymptomatic patients ranged from 0% (Finland) to 26% (Sweden) and among symptomatic patients from 0% (Denmark) to 19% (USA). Variation among centres within countries for CAS was highest in the United States and Australia (from 0% to 80%). The overall proportion of asymptomatic patients was 48%, but varied from 0% (Denmark) to 73% (Italy). There was also substantial centre level variation within each country in the proportion of asymptomatic patients, most pronounced in Australia (0-72%), Hungary (5-55%), and the United States (0-100%). Countries with fee for service reimbursement had higher rates of treatment in asymptomatic patients than countries with population based reimbursement (OR 5.8, 95% CI 4.4-7.7). Conclusions: Despite evidence about treatment options for carotid artery disease, the proportion of asymptomatic patients, treatment modality, and the proportion of women and octogenarians vary considerably among and within countries. There was a significant association of treating more asymptomatic patients in countries with fee for service reimbursement. The findings reflect the inconsistency of the existing guidelines and a need for cooperation among guideline committees all over the world. (C) 2017 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.Peer reviewe

Editor's Choice - Assessment of International Outcomes of Intact Abdominal Aortic Aneurysm Repair over 9 Years

Background: Case mix and outcomes of complex surgical procedures vary over time and between regions. This study analyses peri-operative mortality after intact abdominal aortic aneurysm (AAA) repair in 11 countries over 9 years. Methods: Data on primary AAA repair from vascular surgery registries in 11 countries for the years 2005-2009 and 2010-2013 were analysed. Multivariate adjusted logistic regression analyses were carried out to adjust for variations in case mix. Results: A total of 83,253 patients were included. Over the two periods, the proportion of patients >= 80 years old increased (18.5% vs. 23.1%; p <.0001) as did the proportion of endovascular repair (EVAR) (44.3% vs. 60.6; p <.0001). In the latter period, 25.8% of AAAs were less than 5.5 cm. The mean annual volume of open repairs per centre decreased from 12.9 to 10.6 between the two periods (p <.0001), and it increased for EVAR from 10.0 to 17.1 (p <.0001). Overall, peri-operative mortality fell from 3.0% to 2.4% (p <.0001). Mortality for EVAR decreased from 1.5% to 1.1% (p <.0001), but the outcome worsened for open repair from 3.9% to 4.4% (p = .008). The peri-operative risk was greater for octogenarians (overall, 3.6% vs. 2.1%, p <.0001; open, 9.5% vs. 3.6%, p <.0001; EVAR, 1.8% vs. 0.7%, p <.0001), and women (overall, 3.8% vs. 2.2%, p <.0001; open, 6.0% vs. 4.0%, p <.0001; EVAR, 1.9% vs. 0.9%, p <.0001). Peri-operative mortality after repair of AAAs Conclusions: In this large international cohort, total peri-operative mortality continues to fall for the treatment of intact AAAs. The number of EVAR procedures now exceeds open procedures. Mortality after EVAR has decreased, but mortality for open operations has increased. The peri-operative mortality for small AM treatment, particularly open surgical repair, is still considerable and should be weighed against the risk of rupture. (C) 2017 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.Peer reviewe

Impact of COVID-19 on the Society for Vascular Surgery Vascular Quality Initiative Venous Procedure Registries (Varicose Vein and Inferior Vena Cava Filter)

In response to the pandemic, an abrupt pivot of Vascular Quality Initiative physician members away from standard clinical practice to a restrictive phase of emergent and urgent vascular procedures occurred. The Society for Vascular Surgery Patient Safety Organization queried both data managers and physicians in May 2020. Approximately three-fourths (74%) of physicians adopted restrictive operating policies for urgent and emergent cases only, whereas one-half proceeded with “time sensitive” elective cases as urgent. Data manager case entry was negatively affected by both low case volumes and staffing due to reassignment or furlough. Venous registry volumes were reduced fivefold in the first quarter of 2020 compared with a similar period in 2019. The consequences of delaying vascular procedures for ambulatory venous practice remain unknown with increased morbidity likely. Challenges to determine venous thromboembolism mortality impact exist given difficulty in verifying “in home and extended care facility” deaths. Further ramifications of a pandemic shutdown will likely be amplified if postponement of elective vascular care extends beyond a short window of time. It will be important to monitor disease progression and case severity as a result of policy shifts adopted locally in response to pandemic surges