231 research outputs found
Conformal Mapping on Rough Boundaries II: Applications to bi-harmonic problems
We use a conformal mapping method introduced in a companion paper to study
the properties of bi-harmonic fields in the vicinity of rough boundaries. We
focus our analysis on two different situations where such bi-harmonic problems
are encountered: a Stokes flow near a rough wall and the stress distribution on
the rough interface of a material in uni-axial tension. We perform a complete
numerical solution of these two-dimensional problems for any univalued rough
surfaces. We present results for sinusoidal and self-affine surface whose slope
can locally reach 2.5. Beyond the numerical solution we present perturbative
solutions of these problems. We show in particular that at first order in
roughness amplitude, the surface stress of a material in uni-axial tension can
be directly obtained from the Hilbert transform of the local slope. In case of
self-affine surfaces, we show that the stress distribution presents, for large
stresses, a power law tail whose exponent continuously depends on the roughness
amplitude
Photonic Clusters
We show through rigorous calculations that dielectric microspheres can be
organized by an incident electromagnetic plane wave into stable cluster
configurations, which we call photonic molecules. The long-range optical
binding force arises from multiple scattering between the spheres. A photonic
molecule can exhibit a multiplicity of distinct geometries, including
quasicrystal-like configurations, with exotic dynamics. Linear stability
analysis and dynamical simulations show that the equilibrium configurations can
correspond with either stable or a type of quasi-stable states exhibiting
periodic particle motion in the presence of frictional dissipation.Comment: 4 pages, 3 figure
Testing a Model of Care for Patients on Immune Checkpoint Inhibitors Based on Electronic Patient-Reported Outcomes: Protocol for a Randomized Phase II Controlled Trial.
Management of severe symptomatic immune-related adverse events (IrAEs) related to immune checkpoint inhibitors (ICIs) can be facilitated by timely detection. As patients face a heterogeneous set of symptoms outside the clinical setting, remotely monitoring and assessing symptoms by using patient-reported outcomes (PROs) may result in shorter delays between symptom onset and clinician detection.
We assess the effect of a model of care for remote patient monitoring and symptom management based on PRO data on the time to detection of symptomatic IrAEs from symptom onset. The secondary objectives are to assess its effects on the time between symptomatic IrAE detection and intervention, IrAE grade (severity), health-related quality of life, self-efficacy, and overall survival at 6 months.
For this study, 198 patients with cancer receiving systemic treatment comprising ICIs exclusively will be recruited from 2 Swiss university hospitals. Patients are randomized (1:1) to a digital model of care (intervention) or usual care (control group). Patients are enrolled for 6 months, and they use an electronic app to complete weekly Functional Assessment of Cancer Therapy-General questionnaire and PROMIS (PROs Measurement Information System) Self-Efficacy to Manage Symptoms questionnaires. The intervention patient group completes a standard set of 37 items in a weekly PROs version of the Common Terminology Criteria for Adverse Events (PRO-CTCAE) questionnaire, and active symptoms are reassessed daily for the first 3 months by using a modified 24-hour recall period. Patients can add items from the full PRO-CTCAE item library to their questionnaire. Nurses call patients in the event of new or worsening symptoms and manage them by using a standardized triage algorithm based on the United Kingdom Oncology Nursing Society 24-hour triage tool. This algorithm provides guidance on deciding if patients should receive in-person care, if monitoring should be increased, or if self-management education should be reinforced.
The Institut Suisse de Recherche Expérimentale sur le Cancer Foundation and Kaiku Health Ltd funded this study. Active recruitment began since November 2021 and is projected to conclude in November 2023. Trial results are expected to be published in the first quarter of 2024 and will be disseminated through publications submitted at international scientific conferences.
This trial is among the first trials to use PRO data to directly influence routine care of patients treated with ICIs and addresses some limitations in previous studies. This trial collects a wider spectrum of self-reported symptom data daily. There are some methodological limitations brought by changes in evolving treatment standards for patients with cancer. This trial's results could entail further academic discussions on the challenges of diagnosing and managing symptoms associated with treatment remotely by providing further insights into the burden symptoms represent to patients and highlight the complexity of care procedures involved in managing symptomatic IrAEs.
ClinicalTrials.gov NCT05530187; https://www.clinicaltrials.gov/study/NCT05530187.
DERR1-10.2196/48386
Order-of-magnitude speedup for steady states and traveling waves via Stokes preconditioning in Channelflow and Openpipeflow
Steady states and traveling waves play a fundamental role in understanding
hydrodynamic problems. Even when unstable, these states provide the
bifurcation-theoretic explanation for the origin of the observed states. In
turbulent wall-bounded shear flows, these states have been hypothesized to be
saddle points organizing the trajectories within a chaotic attractor. These
states must be computed with Newton's method or one of its generalizations,
since time-integration cannot converge to unstable equilibria. The bottleneck
is the solution of linear systems involving the Jacobian of the Navier-Stokes
or Boussinesq equations. Originally such computations were carried out by
constructing and directly inverting the Jacobian, but this is unfeasible for
the matrices arising from three-dimensional hydrodynamic configurations in
large domains. A popular method is to seek states that are invariant under
numerical time integration. Surprisingly, equilibria may also be found by
seeking flows that are invariant under a single very large Backwards-Euler
Forwards-Euler timestep. We show that this method, called Stokes
preconditioning, is 10 to 50 times faster at computing steady states in plane
Couette flow and traveling waves in pipe flow. Moreover, it can be carried out
using Channelflow (by Gibson) and Openpipeflow (by Willis) without any changes
to these popular spectral codes. We explain the convergence rate as a function
of the integration period and Reynolds number by computing the full spectra of
the operators corresponding to the Jacobians of both methods.Comment: in Computational Modelling of Bifurcations and Instabilities in Fluid
Dynamics, ed. Alexander Gelfgat (Springer, 2018
Liposomes: a new non-pharmacological therapy concept for seasonal-allergic-rhinoconjunctivitis
Mucosal barrier disorders play an important role in the pathomechanism of the allergic disease. A new approach for their treatment uses liposomes, which consist of phospholipids that make up 75% of the protective nasal surfactant layer. Our aim was to investigate the efficacy of liposomal-based therapy, as a comprehensive treatment alternative to guideline cromoglycate-based therapy, in the treatment of seasonal allergic rhinoconjunctivitis (SAR). We compared nasal and conjunctival symptom reduction with LipoNasal n nasal spray used as monotherapy (LNM), or LipoNasal n nasal spray and Tears Again eye spray combination therapy (LTC), against standard cromoglycate combination therapy (CGC). This prospective, controlled, open observational study was conducted monocentrically. According to their symptoms and preferences 72 patients with SAR were distributed in three equal groups. The study comprised two visits at an interval of 7 days. The efficacy was examined by daily documenting nasal and conjunctival symptom scores. The Nasal-Spray-Sensory-Scale and the Eye-Drops/Spray-Sensory-Scale were used to investigate the tolerability. Quality of life (QoL) was evaluated, using the RHINASTHMA QoL German adapted version. LNM achieved significant improvement in nasal (p < 0.001) and conjunctival symptoms (p = 0.050). The symptom reduction using CGC was equally significant. LTC led to significant nasal symptom relief (p = 0.045). QoL did not improve significantly in all groups (p > 0.05). The tolerability of all treatments was good and no adverse reactions were observed. In all treatment groups the improvement of the nasal and conjunctival symptom scores exceeds the minimal clinically important difference (MCID). The results demonstrate good tolerability and efficacy of non-pharmaceutical liposomal-based treatment (LipoNasal n and Tears Again), given as monotherapy or combination therapy, for nasal and conjunctival symptoms caused by SAR. This study indicates that liposomal-based treatment for SAR may be a comparable alternative to cromoglycate therapy. Further studies are needed to verify these findings
Copernicus Marine Service Ocean State Report
This is the final version. Available from Taylor & Francis via the DOI in this record
A multi-center study on the attitudes of Malaysian emergency health care staff towards allowing family presence during resuscitation of adult patients
BACKGROUND
The practice of allowing family members to witness on-going active resuscitation has been gaining ground in many developed countries since it was first introduced in the early 1990s. In many Asian countries, the acceptability of this practice has not been well studied.
AIM
We conducted a multi-center questionnaire study to determine the attitudes of health care professionals in Malaysia towards family presence to witness ongoing medical procedures during resuscitation.
METHODS
Using a bilingual questionnaire (in Malay and English language), we asked our respondents about their attitudes towards allowing family presence (FP) as well as their actual experience of requests from families to be allowed to witness resuscitations. Multiple logistic regression was used to analyze the association between the many variables and a positive attitude towards FP.
RESULTS
Out of 300 health care professionals who received forms, 270 responded (a 90% response rate). Generally only 15.8% of our respondents agreed to allow relatives to witness resuscitations, although more than twice the number (38.5%) agreed that relatives do have a right to be around during resuscitation. Health care providers are significantly more likely to allow FP if the procedures are perceived as likely to be successful (e.g., intravenous cannulation and blood taking as compared to chest tube insertion). Doctors were more than twice as likely as paramedics to agree to FP (p-value = 0.002). This is probably due to the Malaysian work culture in our health care systems in which paramedics usually adopt a 'follow-the-leader' attitude in their daily practice.
CONCLUSION
The concept of allowing FP is not well accepted among our Malaysian health care providers
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