Self diffusion of particles in complex fluids: temporary cages and permanent barriers

We study the self diffusion of individual particles in dense (non-)uniform complex fluids within dynamic density functional theory and explicitly account for their coupling to the temporally fluctuating background particles. Applying the formalism to rod-like particles in uniaxial nematic and smectic liquid crystals, we find correlated diffusion in different directions: The temporary cage formed by the neighboring particles competes with permanent barriers in periodic inhomogeneous systems such as the lamellar smectic state and delays self diffusion of particles even in uniform systems. We compare our theory with recent experimental data on the self diffusion of fluorescently labelled filamentous virus particles in aqueous dispersions in the smectic phase and find qualitative agreement. This demonstrates the importance of explicitly dealing with the time-dependent self-consistent molecular field that every particle experiences.Comment: submitte

Perceptions, experiences, barriers and facilitators regarding nutritional intake of patients with chronic limb threatening ischemia:a qualitative study

Objective: Patients with chronic limb threatening ischemia (CLTI) are at high risk for amputation and other cardiovascular adverse events. Nutrition-related symptoms and malnutrition are common in the CLTI population, and lead to worse clinical outcomes. Understanding of the factors influencing nutritional intake is required to determine whether optimization of nutritional intake in this population requires interventions. Therefore, this study aimed to describe perceptions and experiences on nutrition of patients with CLTI, and to identify perceived barriers and facilitators influencing their nutritional intake.Methods: In this phenomenological qualitative study, individual semi-structured, face-to-face interviews were conducted with patients with CLTI who lived independently. Interviews were transcribed verbatim, and reflexive thematic analysis was performed.Results: Twelve participants were interviewed. Five themes were generated: (1) lack of nutritional risk perception, (2) role of nutrition for health, functioning and surviving, (3) multiple factors influencing nutritional intake, (4) limited nutritional advice, and (5) no intention to change current nutritional intake.Conclusion: Patients with CLTI perceive nutritional intake as a necessity to survive and function. Patients express limited risk perception regarding adequate nutritional intake and undernutrition. Nutritional intake is mainly based on non-health related factors, as habits and taste, and multiple barriers hinder nutritional intake. Patients received no or only limited nutritional advice. Together this leads to an expressed lack of intention to change nutritional intake. Findings of this study stress the urgency for patient-centered nutritional support, to increase nutrition-related knowledge and motivation, to prevent or treat undernutrition, and may improve clinical outcomes in patients with CLTI

Three-Dimensional Stereophotogrammetry Assessment of Facial Asymmetry in Facial Palsy

Three-dimensional stereophotogrammetry is not much used in assessing facial palsy and a comprehensive understanding of sources of variation in these measurements is lacking. The present study assessed intra- and interobserver reliability of a novel three-dimensional stereophotogrammetry measurement of facial asymmetry and examined sources of variation in these outcomes. Three photographs (rest, closed mouth smile, and maximum smile) were made of 60 participants, 30 facial palsy patients and 30 control subjects. All images were analyzed twice by 2 observers independently, to determine intra- and interobserver reliability. Variance component analysis was performed to investigate sources of variation in the outcomes. Intraobserver reliability was good with intraclass correlation coefficients ranging from 0.715 to 0.999. Interobserver reliability ranged from 0.442 to 0.929. Reliability of the smile image measurements was not clearly different from the rest images. Variation in measurement results was largely due to the status of a participant, facial palsy versus control. When splitting the sample, the facial expression was a major source of variation. Acceptable reliability of the proposed 3D facial asymmetry measurement was found, in facial palsy patients and control subjects. Interobserver reliability was marked less compared to intraobserver reliability. For follow-up data only one observer should assess 3D stereophotogrammetry measurements

Implementing positivity constraints in 4-D resistivity time-lapse inversion

Over the last 25 years 2-D and 3-D resistivity surveys have been used for a wide range of engineering, environmental, hydrological and mineral exploration surveys (Loke et al. 2013). In some surveys, the purpose includes the monitoring of subsurface changes with time (Chambers et al. 2014). The 4-D smoothness-constrained inversion method (Loke et al. 2014) has proved to be a stable and robust method for the inversion of time-lapse data sets. This method inverts the data sets measured at different times simultaneously and it includes a temporal smoothness constraint to ensure that the resistivity changes in a smooth manner with time. In some surveys, such as infiltration experiments (Kuras et al. 2016), it is known that the subsurface resistivity should only decrease (or increase) with time. As the standard 4-D inversion method does not explicitly constrain the direction of the changes with time, this could result in artefacts where an increase in the resistivity is obtained in the inverse model while it is only expected to decrease (or vice versa). In this paper we describe a modification of the 4-D smoothness-constrained inversion method to remove such temporal artefacts

Health-related quality of life in facial palsy:translation and validation of the Dutch version Facial Disability Index

Contains fulltext : 229876.pdf (publisher's version ) (Open Access)PURPOSE: Patient-reported outcome measures are essential in the evaluation of facial palsy. Aim of this study was to translate and validate the Facial Disability Index (FDI) for use in the Netherlands. METHODS: The FDI was translated into Dutch according to a forward-backward method. Construct validity was assessed by formulating 22 hypotheses regarding associations of FDI scores with the Facial Clinimetric Evaluation scale, the Synkinesis Assessment Questionnaire, the Short Form-12 and the Sunnybrook Facial Grading System. Validity was considered adequate if at least 75% (i.e. 17 out of 22) of the hypotheses were confirmed. Additionally, confirmatory factor analysis was performed. Cronbach's α was calculated as a measure of internal consistency. Participants were asked to fill out the FDI a second time after 2 weeks to analyse test-retest reliability. Lastly, smallest detectable change was calculated. RESULTS: In total, 19 hypotheses (86.4%) were confirmed. Confirmatory factor analysis showed acceptable fit for the two factor structure of the original FDI (root mean square error of approximation = 0.064, standardized root mean square residual = 0.081, comparative fit index = 0.925, Chi-square = 50.22 with 34 degrees of freedom). Internal consistency for the FDI physical function scale was good (α > 0.720). Internal consistency for the FDI social/well-being scale was slightly less (α > 0.574). Test-retest reliability for both scales was good (intraclass correlation coefficients > 0.786). Smallest detectable change at the level of the individual was 17.6 points for the physical function and 17.7 points for the social/well-being function, and at group level 1.9 points for both scales. CONCLUSION: The Dutch version FDI shows good psychometric properties. The relatively large values for individual smallest detectable change may limit clinical use. The translation and widespread use of the FDI in multiple languages can help to compare treatment results internationally

Evidence based guidelines for complex regional pain syndrome type 1

Background: Treatment of complex regional pain syndrome type I (CRPS-I) is subject to discussion. The purpose of this study was to develop multidisciplinary guidelines for treatment of CRPS-I. Method: A multidisciplinary task force graded literature evaluating treatment effects for CRPS-I according to their strength of evidence, published between 1980 to June 2005. Treatment recommendations based on the literature findings were formulated and formally approved by all Dutch professional associations involved in CRPS-I treatment. Results: For pain treatment, the WHO analgesic ladder is advised with the exception of strong opioids. For neuropathic pain, anticonvulsants and tricyclic antidepressants may be considered. For inflammatory symptoms, free-radical scavengers (dimethylsulphoxide or acetylcysteine) are advised. To promote peripheral blood flow, vasodilatory medication may be considered. Percutaneous sympathetic blockades may be used to increase blood flow in case vasodilatory medication has insufficient effect. To decrease functional limitations, standardised physiotherapy and occupational therapy are advised. To prevent the occurrence of CRPS-I after wrist fractures, vitamin C is recommended. Adequate perioperative analgesia, limitation of operating time, limited use of tourniquet, and use of regional anaesthetic techniques are recommended for secondary prevention of CRPS-I. Conclusions: Based on the literature identified and the extent of evidence found for therapeutic interventions for CRPS-I, we conclude that further research is needed into each of the therapeutic modalities discussed in the guidelines

The value of routine chest radiographs after minimally invasive cardiac surgery: an observational cohort study

BACKGROUND: Chest radiographs (CXRs) are obtained frequently in postoperative cardiac surgery patients. The diagnostic and therapeutic efficacy of routine CXRs is known to be low and the discussion regarding the safety of abandoning these CXRs after cardiac surgery is still ongoing. We investigated the value of routine CXRs directly after minimally invasive cardiac surgery. METHODS: We prospectively included all patients who underwent minimally invasive cardiac surgery by port access, ministernotomy or bilateral video-assisted thoracoscopy (VATS) in the year 2012. A direct postoperative CXR was performed on all patients at ICU arrival. All CXR findings were noted, including whether they led to an intervention or not. The results were compared to the postoperative CXR results in patients who underwent conventional cardiac surgery by full median sternotomy over the same period. MAIN RESULTS: A total of 249 consecutive patients were included. Most of these patients underwent valve surgery, rhythm surgery or a combination of both. The diagnostic efficacy for minor findings was highest in the port access and bilateral VATS groups (56% and 63% versus 28% and 45%) (p < 0.005). The diagnostic efficacy for major findings was also higher in these groups (8.9% and 11% versus 4.3% and 3.8%) (p = 0.010). The need for an intervention was most common after minimally invasive surgery by port access, although this difference was not statistically significant (p = 0.056). CONCLUSIONS: The diagnostic efficacy of routine CXRs performed after minimally invasive cardiac surgery by port access or bilateral VATS is higher than the efficacy of CXRs performed after conventional cardiac surgery. A routine CXR after these procedures should still be considered

Lime stabilisation for earthworks: a UK perspective

Lime stabilisation is a versatile technique applied during earthworks operations. Modern soil recycling units are much more efficient at pulverising fill material and intermixing the added binder/water than machinery available 20 years ago. While supplier innovation adds flexibility to the site working method, specifications have not been sufficiently updated to permit optimal application. This review paper details the physico-chemical changes instigated through the lime-clay soil reaction, updating previous reviews. It aims to assist scientific debate, current practitioners and future specification changes. For example, the application of the minimum 24 h mellowing periods (mandatory to UK specifications) with high reactivity, quicklime powders is concluded to cause increased air voids in the compacted fill. Increased air voids are associated with reduced long-term strength and potential volume change from water ingress, which is of particular concern for sulfate swelling. Shorter mellowing periods and/or use of hydrated lime may lesson this issue; however, a 'one size fits all' approach is discouraged in preference to site-specific methodologies refined to suit the fill material and project requirements. The discussion also summarises working methods which may lower the risk of sulfate swell and defines areas requiring further practical research

The trade-off between taxi time and fuel consumption in airport ground movement

Environmental impact is a very important agenda item in many sectors nowadays, which the air transportation sector is also trying to reduce as much as possible. One area which has remained relatively unexplored in this context is the ground movement problem for aircraft on the airport’s surface. Aircraft have to be routed from a gate to a runway and vice versa and it is still unknown whether fuel burn and environmental impact reductions will best result from purely minimising the taxi times or whether it is also important to avoid multiple acceleration phases. This paper presents a newly developed multi-objective approach for analysing the trade-off between taxi time and fuel consumption during taxiing. The approach consists of a combination of a graph-based routing algorithm and a population adaptive immune algorithm to discover different speed profiles of aircraft. Analysis with data from a European hub airport has highlighted the impressive performance of the new approach. Furthermore, it is shown that the trade-off between taxi time and fuel consumption is very sensitive to the fuel-related objective function which is used

Oxford consensus on primary cam morphology and femoroacetabular impingement syndrome: part 1—definitions, terminology, taxonomy and imaging outcomes

Introduction Primary cam morphology is a mostly benign bony prominence that develops at the femoral head-neck junction of the hip, but it is highly prevalent in many athlete populations. In the small proportion of athletes for whom it is not benign, the resulting hip osteoarthritis can be debilitating. Clinicians, athletes, patients and researchers do not yet agree on important primary cam morphology elements. We aimed to ascertain and improve the level of agreement on primary cam morphology definitions, terminology, taxonomy and imaging outcome measures. Methods To collect and aggregate informed opinions, an expert panel—the Young Athlete’s Hip Research Collaborative—rated primary cam morphology definition, terminology, taxonomy and imaging outcome statements through an online Delphi exercise followed by an online meeting to explore areas of tension and dissent. Reporting followed Conducting and REporting DElphi Studies. Results A diverse and inclusive Delphi panel (n=65 for rounds 1 and 2, representing 18 countries; 6 stakeholder groups; 40% women) agreed on 35 of 47 statements in 4 domains, while surfacing areas of tension and dissent. This Delphi panel agreed on four key issues essential to moving research and clinical care forward around primary cam morphology. They agreed on: (1) definition, confirming its conceptual attributes (tissue type, size, location, shape and ownership); (2) terminology—use ‘morphology’ and not terms with a negative connotation like ‘lesion’, ‘abnormality’ or ‘deformity’; (3) taxonomy, distinguishing between primary and secondary cam morphology, and (4) imaging outcomes, a continuous bone/cartilage alpha angle on radial femoral head-neck MRI for primary cam morphology aetiology research. Conclusion This consensus provides athletes, patients, clinicians and researchers with a strong foundation to guide more precise communication, better clinical decision-making and higher value research about primary cam morphology and its natural history