377 research outputs found
Collective diffusion coefficient of proteins with hydrodynamic, electrostatic and adhesive interactions
A theory is presented for lambda_C, the coefficient of the first-order
correction in the density of the collective diffusion coefficient, for protein
spheres interacting by electrostatic and adhesive forces. An extensive
numerical analysis of the Stokesian hydrodynamics of two moving spheres is
given so as to gauge the precise impact of lubrication forces. An effective
stickiness is introduced and a simple formula for lambda_C in terms of this
variable is put forward. A precise though more elaborate approximation for
lambda_C is also developed. These and numerically exact expressions for
lambda_C are compared with experimental data on lysozyme at pH 4.5 and a range
of ionic strengths between 0.05 M and 2 M.Comment: 8 pages, 3 figures, 1 tabl
Macroporous materials: microfluidic fabrication, functionalization and applications
This article provides an up-to-date highly comprehensive overview (594 references) on the state of the art of the synthesis and design of macroporous materials using microfluidics and their applications in different fields
Mesoscale simulations of surfactant dissolution and mesophase formation
The evolution of the contact zone between pure surfactant and solvent has
been studied by mesoscale simulation. It is found that mesophase formation
becomes diffusion controlled and follows the equilibrium phase diagram
adiabatically almost as soon as individual mesophases can be identified,
corresponding to times in real systems of order 10 microseconds.Comment: 4 pages, 2 figures, ReVTeX
Methods used in the selection of instruments for outcomes included in core outcome sets have improved since the publication of the COSMIN/COMET guideline
Objectives: Once a core outcome set (COS) has been defined, it is important to achieve consensus on how these outcomes should be measured. The aims of this systematic review were to gain insight into the methods used to select outcome measurement instruments and to determine whether methods have improved following the COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN)/Core Outcome Measures in Effectiveness Trials (COMET) guideline publication. Study Design and Setting: Eligible articles, which were identified from the annual COMET systematic review, concerned any COS development studies that provided a recommendation on how to measure the outcomes included in the COS. Data were extracted on the methods used to select outcome measurement instruments in accordance with the COSMIN/COMET guideline. Results: Of the 118 studies included in the review, 48% used more than one source of information when finding outcome measurement instruments, and 74% performed some form of quality assessment of the measurement instruments. Twenty-three studies recommended one single instrument for each core outcome included in the COS. Clinical experts and public representatives were involved in selecting instruments in 62% and 28% of studies, respectively. Conclusion: Methods used to select outcome measurement instruments have improved since the publication of the COSMIN/COMET guideline. Going forward, COS developers should ensure that recommended outcome measurement instruments have sufficient content validity. In addition, COS developers should recommend one instrument for each core outcome to contribute to the overarching goal of uniformity in outcome reporting
Standardized reporting of the Eczema Area and Severity Index (EASI) and the Patient-Oriented Eczema Measure (POEM): a recommendation by the Harmonising Outcome Measures for Eczema (HOME) Initiative
Several organizations from multiple fields of medicine are setting standards for clinical research including protocol development,1 harmonization of outcome reporting,2 statistical analysis,3 quality assessment4 and reporting of findings.1 Clinical research standardization facilitates the interpretation and synthesis of data, increases the usability of trial results for guideline groups and shared decision‐making, and reduces selective outcome reporting bias. The mission of the Harmonising Outcome Measures for Eczema (HOME) initiative is to establish an agreed‐upon core set of outcomes to be measured and reported in all clinical trials of atopic dermatitis (AD)
Dietary iron intakes based on food composition data may underestimate the contribution of potentially exchangeable contaminant iron from soil
Iron intakes calculated from one-day weighed records were compared with those from same day analyzed duplicate diet composites collected from 120 Malawian women living in two rural districts with contrasting soil mineralogy and where threshing may contaminate cereals with soil iron. Soils and diet composites from the two districts were then subjected to a simulated gastrointestinal digestion and iron availability in the digests measured using a Caco-2 cell model. Median analyzed iron intakes (mg/d) were higher (p < 0.001) than calculated intakes in both Zombwe (16.6 vs. 10.1 mg/d) and Mikalango (29.6 vs. 19.1 mg/d), attributed to some soil contaminant iron based on high Al and Ti concentrations in diet composites. A small portion of iron in acidic soil from Zombwe, but not Mikalango calcareous soil, was bioavailable, as it induced ferritin expression in the cells, and may have contributed to higher plasma ferritin and total body iron for the Zombwe women reported earlier, despite lower iron intakes. In conclusion, iron intakes calculated from food composition data were underestimated, highlighting the importance of analyzing duplicate diet composites where extraneous contaminant iron from soil is likely. Acidic contaminant soil may make a small but useful contribution to iron nutrition
Vapour-liquid coexistence in many-body dissipative particle dynamics
Many-body dissipative particle dynamics is constructed to exhibit
vapour-liquid coexistence, with a sharp interface, and a vapour phase of
vanishingly small density. In this form, the model is an unusual example of a
soft-sphere liquid with a potential energy built out of local-density dependent
one-particle self energies. The application to fluid mechanics problems
involving free surfaces is illustrated by simulation of a pendant drop.Comment: 8 pages, 6 figures, revtex
A Robot based Hybrid Lower-Limb System for Assist-As-Needed Rehabilitation of Stroke Patients:Technical Evaluation and Clinical Feasibility
Background: Although early rehabilitation is important following a stroke, severely affected patients have limited options for intensive rehabilitation as they are often bedridden. To create a system for early rehabilitation of lower extremities in severely affected patients, we have combined the robotic manipulator ROBERT® and EMG-triggered FES and developed a novel user-driven Assist- As-Needed (AAN) control approach. The method is based on a state machine that can detect user movement capability and provide different levels of assistance, as required by the patient (no support, FES only, and simultaneous FES and mechanical support).
Methods: To technically validate the system, we tested 10 able-bodied participants who were instructed to perform specific behaviors to trigger the desired system states while conducting knee extension and ankle dorsal flexion exercise. In addition, the system was tested on two stroke patients to establish the clinical feasibility.
Results: The technical validation showed that the state machine correctly detected the participants’ behavior and activated the target AAN state in more than 96% of the exercise repetitions. The clinical feasibility test showed that the system successfully recognized the patients’ movement capacity and activated assistive states according to their needs, providing the minimal level of support required to perform the exercise successfully.
Conclusions: The system was technically validated and preliminarily proven clinically feasible. The present study shows that the novel system can be used to deliver exercises with a high number of repetitions while engaging the participants’ residual capabilities through an effective AAN strategy.</p
The COMET Handbook: version 1.0
The selection of appropriate outcomes is crucial when designing clinical trials in order to compare the effects of different interventions directly. For the findings to influence policy and practice, the outcomes need to be relevant and important to key stakeholders including patients and the public, health care professionals and others making decisions about health care. It is now widely acknowledged that insufficient attention has been paid to the choice of outcomes measured in clinical trials. Researchers are increasingly addressing this issue through the development and use of a core outcome set, an agreed standardised collection of outcomes which should be measured and reported, as a minimum, in all trials for a specific clinical area. Accumulating work in this area has identified the need for guidance on the development, implementation, evaluation and updating of core outcome sets. This Handbook, developed by the COMET Initiative, brings together current thinking and methodological research regarding those issues. We recommend a four-step process to develop a core outcome set. The aim is to update the contents of the Handbook as further research is identified
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