Mediamusic (E-Journal)
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Tuning of Morphology by Chirality in Self-Assembled Structures of Bis(Urea) Amphiphiles in Water
No full textWe present the synthesis and self-assembly of a chiral bis(urea) amphiphile and show that chirality offers a remarkable level of control towards different morphologies. Upon self-assembly in water, the molecular-scale chiral information is translated to the mesoscopic level. Both enantiomers of the amphiphile self-assemble into chiral twisted ribbons with opposite handedness, as supported by Cryo-TEM and circular dichroism (CD) measurements. The system presents thermo-responsive aggregation behavior and combined transmittance measurements, temperature-dependent UV, CD, TEM, and micro-differential scanning calorimetry (DSC) show that a ribbon-to-vesicles transition occurs upon heating. Remarkably, chirality allows easy control of morphology as the self-assembly into distinct aggregates can be tuned by varying the enantiomeric excess of the amphiphile, giving access to flat sheets, helical ribbons, and twisted ribbons.</p
Site-specific contribution of Toll-like receptor 4 to intestinal homeostasis and inflammatory disease
No full textToll-like receptor 4 (TLR4) is a highly conserved protein of innate immunity, responsible for the regulation and maintenance of homeostasis, as well as immune recognition of external and internal ligands. TLR4 is expressed on a variety of cell types throughout the gastrointestinal tract, including on epithelial and immune cell populations. In a healthy state, epithelial cell expression of TLR4 greatly assists in homeostasis by shaping the host microbiome, promoting immunoglobulin A production, and regulating follicle-associated epithelium permeability. In contrast, immune cell expression of TLR4 in healthy states is primarily centred on the maturation of dendritic cells in response to stimuli, as well as adequately priming the adaptive immune system to fight infection and promote immune memory. Hence, in a healthy state, there is a clear distinction in the site-specific roles of TLR4 expression. Similarly, recent research has indicated the importance of site-specific TLR4 expression in inflammation and disease, particularly the impact of epithelial-specific TLR4 on disease progression. However, the majority of evidence still remains ambiguous for cell-specific observations, with many studies failing to provide the distinction of epithelial versus immune cell expression of TLR4, preventing specific mechanistic insight and greatly impacting the translation of results. The following review provides a critical overview of the current understanding of site-specific TLR4 activity and its contribution to intestinal/immune homeostasis and inflammatory diseases.</p
Cross docking for libraries with a depot
No full textLibrary organizations in the Netherlands show an increasing interest to employ depots for low-cost storage and demand fulfillment of item requests. Typically, all libraries in an organization have a shared catalog, and, on local unavailability, requests can be shipped from elsewhere in the organization. The depot can be used to consolidate shipment requests by making tours along all libraries, delivering requested items, but also picking up items that have to be stored at the depot, or that have to be shipped from one library to another. Cross docking and delayed shipments are two preferred methods for fulfilling requests that cannot be directly met using on-hand stock at the depot. In this paper, we compare these two methods from an inventory control perspective. We model the library system as a Markov Decision process. For one- and two-location systems, we derive analytical results for the average-cost optimal policy, showing that the decision to store items from the location at the depot satisfies a threshold structure depending on the number of rented items. For larger instances, an effective heuristic is proposed exploiting this threshold structure. In numerical experiments, important managerial insights are obtained by comparing cross docking and delayed shipments in different situations. Cross docking is shown to add most value in systems with low total stock, however, delayed shipments may achieve similar costs as cross docking when stock is high or when tours frequently visit all locations. Furthermore, effective decisions can be based on simple model formulations with memoryless rental time distributions
Development and Evaluation of the Taxonomy of Trauma Leadership Skills-Shortened for Observation and Reflection in Training:A Practical Tool for Observing and Reflecting on Trauma Leadership Performance
No full textINTRODUCTION: Trauma leadership skills are increasingly being addressed in trauma courses, but few resources are available to systematically observe and debrief trainees' performances. The authors therefore translated their previously developed, extensive Taxonomy of Trauma Leadership Skills (TTLS) into a practical observation tool that is tailored to the vocabulary of clinician instructors and their workflow and workload during simulation-based training.METHODS: In 2016 to 2018, the TTLS was subjected to practical evaluation in an iterative process of 2 stages. In the first stage, testing panels of trauma specialists observed excerpts from videotaped simulations and indicated from the list of elements which behaviors they felt were being shown. Any ambiguities or redundancy were addressed by rephrasing or combining elements. In the second stage, iterations were used in actual scenario training to observe and debrief trainees' performances. The instructors' recommendations resulted in further improvements of clarity, ease of use, and usefulness, until no new suggestions were raised.RESULTS: The resultant "TTLS-Shortened for Observation and Reflection in Training" was given a simpler structure and more concrete and self-explanatory benchmarks. It contains 6 skill categories for evaluation, each with 4 to 6 benchmark behaviors.CONCLUSIONS: The TTLS-Shortened for Observation and Reflection in Training is an important addition to other trauma assessment tools because of its specific focus on leadership skills. It helps set concrete performance expectations, simplify note taking, and target observations and debriefings. One central challenge was striking a balance between its conciseness and specificity. The authors reflected on how the decisions for the resultant structure ease and leverage the conduct of observations and performance debriefing.</p
The role of device asymmetries and Schottky barriers on the helicity-dependent photoresponse of 2D phototransistors
No full textCircular photocurrents (CPC), namely circular photogalvanic (CPGE) and photon drag effects, have recently been reported both in monolayer and multilayer transition metal dichalcogenide (TMD) phototransistors. However, the underlying physics for the emergence of these effects are not yet fully understood. In particular, the emergence of CPGE is not compatible with the D3h crystal symmetry of two-dimensional TMDs, and should only be possible if the symmetry of the electronic states is reduced by influences such as an external electric field or mechanical strain. Schottky contacts, nearly ubiquitous in TMD-based transistors, can provide the high electric fields causing a symmetry breaking in the devices. Here, we investigate the effect of these Schottky contacts on the CPC by characterizing the helicity-dependent photoresponse of monolayer MoSe2 devices both with direct metal-MoSe2 Schottky contacts and with h-BN tunnel barriers at the contacts. We find that, when Schottky barriers are present in the device, additional contributions to CPC become allowed, resulting in emergence of CPC for illumination at normal incidence
Sometimes Your Best Just Ain’t Good Enough:The Worldwide Evidence on Subjective Well-being Efficiency
No full textMost of the studies on subjective well-being focus on the determinants of absolute life satisfaction or happiness levels. This paper asks an important but understudied question, namely, could countries achieve the same or even higher subjective well-being by using the same resources more efficiently? We provide the first country panel evidence on whether nations efficiently transform their endowments (income, education, and health) into subjective well-being and which factors influence the conversion efficiency. Using data on 91 countries from 2009 to 2014, we find that that well-being efficiency gains are possible worldwide. We show that poor labor market conditions as proxied by unemployment and involuntary part-time employment are associated with lower 'subjective well-being efficiency,' while social support, freedom, and the rule of law improve it. These findings are useful to policymakers in helping identify inefficiencies, reducing wasteful resource use, and developing policies that promote sustainable development and human well-being. Our results are robust to a battery of sensitivity checks and raise policy-relevant questions about the appropriate instruments to improve subjective well-being efficiency.</p
Clinical value of diffusion-weighted MRI for differentiation between benign and malignant gallbladder disease:a systematic review and meta-analysis
No full textBACKGROUND: Radiological differentiation between benign and malignant gallbladder disease is important but remains challenging. Furthermore, the clinical value of diffusion-weighted imaging (DWI) remains unclear.PURPOSE: To determine the value of DWI in discriminating benign from malignant gallbladder disease by conducting a systematic review and meta-analysis.MATERIAL AND METHODS: The literature was systematically searched. Studies analyzing diagnostic value of DWI in gallbladder disease with histopathology or follow-up as reference standard were included. Study selection and data extraction were done by two reviewers independently. Methodological quality was assessed using the QUADAS-2 tool. Sensitivity and specificity were calculated and displayed in a forest plot. A sensitivity analysis was performed in case of outliers. Pooled sensitivity and specificity of DWI were plotted on a hierarchical summary receiver operating characteristic curve. If available, the added value of DWI to conventional magnetic resonance imaging (MRI) sequences was analyzed.RESULTS: Out of 2456 articles, eight studies fulfilled the inclusion criteria; 592 patients with 221 malignant lesions were included. Pooled sensitivity and specificity rates were 0.87 and 0.84, respectively. In two studies, diagnostic accuracy rates improved after adding DWI to conventional MRI (64% and 75% for conventional MRI vs. 89% and 94% after combining conventional MRI with DWI). In another study, the area under the curve increased from 0.92 to 0.95.CONCLUSION: DWI appears to be an accurate imaging technique in discriminating benign from malignant gallbladder disease. To achieve optimal patient care, it should be part of multiparametric MRI and should be combined with other imaging modalities.</p
Effects of macronutrient intake in obesity:A meta-analysis of low-carbohydrate and low-fat diets on markers of the metabolic syndrome
No full textThe metabolic syndrome (MetS) comprises cardiometabolic risk factors frequently found in individuals with obesity. Guidelines to prevent or reverse MetS suggest limiting fat intake, however, lowering carbohydrate intake has gained attention too. The aim for this review was to determine to what extent either weight loss, reduction in caloric intake, or changes in macronutrient intake contribute to improvement in markers of MetS in persons with obesity without cardiometabolic disease. A meta-analysis was performed across a spectrum of studies applying low-carbohydrate (LC) and low-fat (LF) diets. PubMed searches yielded 17 articles describing 12 separate intervention studies assessing changes in MetS markers of persons with obesity assigned to LC (<40% energy from carbohydrates) or LF (<30% energy from fat) diets. Both diets could lead to weight loss and improve markers of MetS. Meta-regression revealed that weight loss most efficaciously reduced fasting glucose levels independent of macronutrient intake at the end of the study. Actual carbohydrate intake and actual fat intake at the end of the study, but not the percent changes in intake of these macronutrients, improved diastolic blood pressure and circulating triglyceride levels, without an effect of weight loss. The homeostatic model assessment of insulin resistance improved with both diets, whereas high-density lipoprotein cholesterol only improved in the LC diet, both irrespective of aforementioned factors. Remarkably, changes in caloric intake did not play a primary role in altering MetS markers. Taken together, these data suggest that, beyond the general effects of the LC and LF diet categories to improve MetS markers, there are also specific roles for weight loss, LC and HF intake, but not reduced caloric intake, that improve markers of MetS irrespective of diet categorization. On the basis of the results from this meta-analysis, guidelines to prevent MetS may need to be re-evaluated.</p
Effectiveness of a Tailored Work-Related Support Intervention for Patients Diagnosed with Gastrointestinal Cancer:A Multicenter Randomized Controlled Trial
No full textPurpose The aim of this research was to study the effectiveness on return to work (RTW) of an early tailored work-related support intervention in patients diagnosed with curative gastrointestinal cancer. Methods A multicenter randomized controlled trial was undertaken, in which patients were assigned randomly to the intervention or the control group (usual care). The intervention encompassed three psychosocial work-related support meetings, starting before treatment. Five self-reported questionnaires were sent over twelve months of follow-up. Primary outcome was days until RTW (fulltime or partial) and secondary outcomes included work status, quality of life, work ability, and work limitations. Descriptive analysis, Kaplan–Meier analysis, relative risk ratio and linear mixed models were applied. Results Participants (N = 88) had a mean age of 55 years; 67% were male and the most common cancer type was colon cancer (66%). Of the participants, 42 were randomized to the intervention group. The median time from sick leave until RTW was 233 days (range 187–279 days) for the control group, versus 190 days (range 139–240 days) for the intervention group (log-rank p = 0.37). The RTW rate at twelve months after baseline was 83.3% for the intervention group and 73.5% for the control group. Work limitations did statistically differ between the groups over time (p = 0.01), but quality of life and work ability did not. Conclusion Patients in the intervention group seem to take fewer days to RTW, albeit not to a statistically significant extent. Trial registration Trial NL4920 (NTR5022) (Dutch Trial Register https://www.trialregister.nl).</p