Unsteady Heat-Flux Measurements of Second-Mode Instability Waves in a Hypersonic Boundary Layer

In this paper, we report on the application of the atomic layer thermopile (ALTP) heat-flux sensor to the measurement of laminar-to-turbulent transition in a hypersonic flat-plate boundary layer. The centerline of the flat-plate model was instrumented with a streamwise array of ALTP sensors, and the flat-plate model was exposed to a Mach 6 freestream over a range of unit Reynolds numbers. Here, we observed an unstable band of frequencies that are associated with second-mode instability waves in the laminar boundary layer that forms on the flat-plate surface. The measured frequencies, group velocities, phase speeds, and wavelengths of these instability waves are consistent with data previously reported in the literature. Heat flux time series, and the Morlet wavelet transforms of them, revealed the wave-packet nature of the second-mode instability waves. In addition, a laser-based radiative heating system was used to measure the frequency response functions (FRF) of the ALTP sensors used in the wind tunnel test. These measurements were used to assess the stability of the sensor FRFs over time and to correct spectral estimates for any attenuation caused by the finite sensor bandwidth

Unsteady Heat-Flux Measurements of Second-Mode Instability Waves in a Hypersonic Boundary Layer

In this paper we report on the application of the atomic layer thermopile (ALTP) heat- flux sensor to the measurement of laminar-to-turbulent transition in a hypersonic flat plate boundary layer. The centerline of the flat-plate model was instrumented with a streamwise array of ALTP sensors and the flat-plate model was exposed to a Mach 6 freestream over a range of unit Reynolds numbers. Here, we observed an unstable band of frequencies that are associated with second-mode instability waves in the laminar boundary layer that forms on the flat-plate surface. The measured frequencies, group velocities, phase speeds, and wavelengths of these instability waves are in agreement with data previously reported in the literature. Heat flux time series, and the Morlet-wavelet transforms of them, revealed the wave-packet nature of the second-mode instability waves. In addition, a laser-based radiative heating system was developed to measure the frequency response functions (FRF) of the ALTP sensors used in the wind tunnel test. These measurements were used to assess the stability of the sensor FRFs over time and to correct spectral estimates for any attenuation caused by the finite sensor bandwidth

Unsteady Heat-Flux Measurements of Second-Mode Instability Waves

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A multicomponent family support intervention in intensive care units: study protocol for a multicenter cluster-randomized trial (FICUS Trial)

Background: Family members of critically ill patients face considerable uncertainty and distress during their close others' intensive care unit (ICU) stay. About 20-60% of family members experience adverse mental health outcomes post-ICU, such as symptoms of anxiety, depression, and posttraumatic stress. Guidelines recommend structured family inclusion, communication, and support, but the existing evidence base around protocolized family support interventions is modest and requires substantiation. Methods: To test the clinical effectiveness and explore the implementation of a multicomponent, nurse-led family support intervention in ICUs, we will undertake a parallel, cluster-randomized, controlled, multicenter superiority hybrid-type 1 trial. It will include eight clusters (ICUs) per study arm, with a projected total sample size of 896 family members of adult, critically ill patients treated in the German-speaking part of Switzerland. The trial targets family members of critically ill patients with an expected ICU stay of 48 h or longer. Families in the intervention arm will receive a family support intervention in addition to usual care. The intervention consists of specialist nurse support that is mapped to the patient pathway with follow-up care and includes psycho-educational and relationship-focused family interventions, and structured, interprofessional communication, and shared decision-making with families. Families in the control arm will receive usual care. The primary study endpoint is quality of family care, operationalized as family members' satisfaction with ICU care at discharge. Secondary endpoints include quality of communication and nurse support, family management of critical illness (functioning, resilience), and family members' mental health (well-being, psychological distress) measured at admission, discharge, and after 3, 6, and 12 months. Data of all participants, regardless of protocol adherence, will be analyzed using linear mixed-effects models, with the individual participant as the unit of inference. Discussion: This trial will examine the effectiveness of the family support intervention and generate knowledge of its implementability. Both types of evidence are necessary to determine whether the intervention works as intended in clinical practice and could be scaled up to other ICUs. The study findings will make a significant contribution to the current body of knowledge on effective ICU care that promotes family participation and well-being. Trial registration: ClinicalTrials.gov NCT05280691 . Prospectively registered on 20 February 2022. Keywords: Anxiety (MeSH); Cluster-randomized controlled trial (non-MeSH); Depression (MeSH); Family (MeSH); Family nursing (MeSH); Intensive care (MeSH); Post-traumatic stress disorder (MeSH); Postintensive care syndrome – family (non-MeSH); Satisfaction with care (non-MeSH

A multicomponent family support intervention in intensive care units: study protocol for a multicenter cluster-randomized trial (FICUS Trial).

BACKGROUND Family members of critically ill patients face considerable uncertainty and distress during their close others' intensive care unit (ICU) stay. About 20-60% of family members experience adverse mental health outcomes post-ICU, such as symptoms of anxiety, depression, and posttraumatic stress. Guidelines recommend structured family inclusion, communication, and support, but the existing evidence base around protocolized family support interventions is modest and requires substantiation. METHODS To test the clinical effectiveness and explore the implementation of a multicomponent, nurse-led family support intervention in ICUs, we will undertake a parallel, cluster-randomized, controlled, multicenter superiority hybrid-type 1 trial. It will include eight clusters (ICUs) per study arm, with a projected total sample size of 896 family members of adult, critically ill patients treated in the German-speaking part of Switzerland. The trial targets family members of critically ill patients with an expected ICU stay of 48 h or longer. Families in the intervention arm will receive a family support intervention in addition to usual care. The intervention consists of specialist nurse support that is mapped to the patient pathway with follow-up care and includes psycho-educational and relationship-focused family interventions, and structured, interprofessional communication, and shared decision-making with families. Families in the control arm will receive usual care. The primary study endpoint is quality of family care, operationalized as family members' satisfaction with ICU care at discharge. Secondary endpoints include quality of communication and nurse support, family management of critical illness (functioning, resilience), and family members' mental health (well-being, psychological distress) measured at admission, discharge, and after 3, 6, and 12 months. Data of all participants, regardless of protocol adherence, will be analyzed using linear mixed-effects models, with the individual participant as the unit of inference. DISCUSSION This trial will examine the effectiveness of the family support intervention and generate knowledge of its implementability. Both types of evidence are necessary to determine whether the intervention works as intended in clinical practice and could be scaled up to other ICUs. The study findings will make a significant contribution to the current body of knowledge on effective ICU care that promotes family participation and well-being. TRIAL REGISTRATION ClinicalTrials.gov NCT05280691 . Prospectively registered on 20 February 2022

Spiritualität und Behandlung: Die Perspektive von Patienten mit chronischen Schmerzen

Background: Chronic pain affects all aspects of human life, which raises spiritual questions that should be included within the framework of multimodal care. Objectives: We investigated the perspective of patients with chronic pain around spiritual concerns and their potential integration into care. Materials and methods: We conducted five focus group interviews and two small group interviews. In total, 42 patients with chronic pain in outpatient or inpatient pain care at the time of the study participated. The interviews were transcribed and thematically analyzed. Results: Three themes emerged: (1) Chronic pain permeates the entity of a person's existence. (2) Spiritual resources are potentially supportive in living with chronic pain. (3) Patients appreciate the opportunity to engage with health care professionals in a dialog that encompasses spiritual concerns. For participants, these concerns have considerable relevance. In many cases participants associated them with religious convictions, but not exclusively. They often related feeling that their pain experience was dismissed. Conclusion: Finding strategies for effectively dealing with chronic pain represents a turning point in life. Open discussion with health care professionals that allow for spiritual issues facilitates this process. == Hintergrund: Chronischer Schmerz betrifft alle menschlichen Lebensdimensionen und wirft auch spirituelle Fragen auf, die im Rahmen eines multimodalen Behandlungsmodells berücksichtigt werden sollten. Ziel der Arbeit: Wir untersuchten die Perspektive von Patienten mit chronischen Schmerzen zu spirituellen Themen und deren möglicher Integration in den Behandlungsprozess. Material und Methoden: Es wurden fünf Fokusgruppen- und zwei Kleingruppeninterviews an fünf Studienzentren durchgeführt. Daran nahmen 42 Patienten mit chronischen Schmerzen teil, die aktuell in ambulanter oder stationärer Schmerzbehandlung waren. Die Interviews wurden transkribiert und einer thematischen Analyse unterzogen. Ergebnisse: Drei Themen traten hervor: 1. Chronischer Schmerz durchdringt die gesamte menschliche Existenz. 2. Spirituelle Ressourcen stellen eine Möglichkeit im Umgang mit chronischen Schmerzen dar. 3. Patienten ist es ein Anliegen, mit Fachpersonen in einen Dialog treten zu können, der auch für spirituelle Themen offen ist. Diese haben aus Sicht der Teilnehmenden große Relevanz. Sie verknüpften sie vielfach, aber nicht ausschließlich mit religiösen Überzeugungen. Häufig wurde geschildert, in der Schmerzerfahrung nicht ernst genommen zu werden. Diskussion: Strategien für einen effektiven Umgang mit chronischem Schmerz zu finden, stellt einen Wendepunkt im Leben dar. In diesem Prozess unterstützt ein offener Dialog mit Fachpersonen, der auch spirituellen Themen Rechnung trägt

Identification of Rare High-Avidity, Tumor-Reactive CD8+ T Cells by Monomeric TCR-Ligand Off-Rates Measurements on Living Cells.

The avidity of the T-cell receptor (TCR) for antigenic peptides presented by the peptide-MHC (pMHC) on cells is a key parameter for cell-mediated immunity. Yet a fundamental feature of most tumor antigen-specific CD8(+) T cells is that this avidity is low. In this study, we addressed the need to identify and select tumor-specific CD8(+) T cells of highest avidity, which are of the greatest interest for adoptive cell therapy in patients with cancer. To identify these rare cells, we developed a peptide-MHC multimer technology, which uses reversible Ni(2+)-nitrilotriacetic acid histidine tags (NTAmers). NTAmers are highly stable but upon imidazole addition, they decay rapidly to pMHC monomers, allowing flow-cytometric-based measurements of monomeric TCR-pMHC dissociation rates of living CD8(+) T cells on a wide avidity spectrum. We documented strong correlations between NTAmer kinetic results and those obtained by surface plasmon resonance. Using NTAmers that were deficient for CD8 binding to pMHC, we found that CD8 itself stabilized the TCR-pMHC complex, prolonging the dissociation half-life several fold. Notably, our NTAmer technology accurately predicted the function of large panels of tumor-specific T cells that were isolated prospectively from patients with cancer. Overall, our results demonstrated that NTAmers are effective tools to isolate rare high-avidity cytotoxic T cells from patients for use in adoptive therapies for cancer treatment