Efficacy of a hands-free vascular ultrasound probe holder in active and inactive limbs during cycling exercise.

Measurement of blood flow during exercise is crucial for understanding physiological responses and performance outcomes. However, traditional methods are often invasive, costly, or require substantial training, limiting widespread research in this area. This study introduces the innovative use of limb-affixed ultrasound probe holders for vascular imaging during exercise to overcome these challenges.

Multidirectional blood flow in the femoral artery via vector flow imaging: Doppler ultrasound imaging insights.

The accuracy of femoral artery blood flow measurements via Doppler ultrasound hinges on assumptions of laminar flow upstream of the femoral bifurcation. Existing scanning guidelines recommend a minimum proximity to the flow divider of 2-3 cm for avoiding multidirectional blood flow yet lack experimental evidence to support this recommendation. This study aimed to determine the minimum distance required to avoid multidirectional flow contamination near the femoral bifurcation and to assess the reliability of vector flow imaging (VFI) in these measurements.

Impact of Ultrasound Scanning Plane on Common Carotid Artery Longitudinal Wall Motion.

Objective: The arterial wall not only moves in the radial direction to expand circumferentially but also moves in the axial (longitudinal) direction in a predictable bidirectional pattern during a normal cardiac cycle. While common carotid artery (CCA) longitudinal wall motion (CALM) has been described previously, there is a lack of evidence-based method standardization to align practices for human measurement. The purpose of this study was to evaluate whether different scanning planes impact CALM outcomes in healthy males and females to provide clarity on data collection strategies.

Fludrocortisone dose-response relationship in septic shock: a randomised phase II trial.

Background: The combination of intravenous hydrocortisone and enteral fludrocortisone may reduce mortality in patients with septic shock. The optimal dose and reliability of absorption of fludrocortisone in critically ill patients are unclear.

Methods: In a multi-centre, open label, phase II randomized clinical trial, intravenous hydrocortisone alone or in combination with one of three doses of enteral fludrocortisone (50 µg, 100 µg or 200 µg daily) for 7 days was compared in patients with septic shock.

Are Wearable Photoplethysmogram-Based Heart Rate Variability Measures Equivalent to Electrocardiogram? A Simulation Study.

Background: Traditional electrocardiography (ECG)-derived heart rate variability (HRV) and photoplethysmography (PPG)-derived "HRV" (termed PRV) have been reported interchangeably. Any potential dissociation between HRV and PRV could be due to the variability in pulse arrival time (PAT; time between heartbeat and peripheral pulse).

Objective: This study examined if PRV is equivalent to ECG-derived HRV and if PRV's innate error makes it a high-quality measurement separate from HRV.

Characterization of internal jugular vein region-specific distension and flow patterns during progressive volume shifting.

Blood volume shifts during postural adjustment lead to irregular distension of the internal jugular vein (IJV). In microgravity, distension may contribute to flow stasis and thromboembolism, though the regional implications and associated risk remain unexplored. We characterized regional differences in IJV volume distension and flow complexity during progressive head-down tilt (HDT) (0°, -6°, -15°, -30°) using conventional ultrasound and vector flow imaging.

A meta-analysis on global change drivers and the risk of infectious disease.

Anthropogenic change is contributing to the rise in emerging infectious diseases, which are significantly correlated with socioeconomic, environmental and ecological factors. Studies have shown that infectious disease risk is modified by changes to biodiversity, climate change, chemical pollution, landscape transformations and species introductions. However, it remains unclear which global change drivers most increase disease and under what contexts.

Are novel or locally adapted pathogens more devastating and why? Resolving opposing hypotheses.

There is a rich literature highlighting that pathogens are generally better adapted to infect local than novel hosts, and a separate seemingly contradictory literature indicating that novel pathogens pose the greatest threat to biodiversity and public health. Here, using Batrachochytrium dendrobatidis, the fungus associated with worldwide amphibian declines, we test the hypothesis that there is enough variance in "novel" (quantified by geographic and phylogenetic distance) host-pathogen outcomes to pose substantial risk of pathogen introductions despite local adaptation being common. Our continental-scale common garden experiment and global-scale meta-analysis demonstrate that local amphibian-fungal interactions result in higher pathogen prevalence, pathogen growth, and host mortality, but novel interactions led to variable consequences with especially virulent host-pathogen combinations still occurring.

Specific connectivity optimizes learning in thalamocortical loops.

Thalamocortical loops have a central role in cognition and motor control, but precisely how they contribute to these processes is unclear. Recent studies showing evidence of plasticity in thalamocortical synapses indicate a role for the thalamus in shaping cortical dynamics through learning. Since signals undergo a compression from the cortex to the thalamus, we hypothesized that the computational role of the thalamus depends critically on the structure of corticothalamic connectivity.

Patient-Level Meta-Analysis of Low-Dose Hydrocortisone in Adults with Septic Shock.

BACKGROUND: Trials and study-level meta-analyses have failed to resolve the role of corticosteroids in the management of patients with septic shock. Patient-level meta-analyses may provide more precise estimates of treatment effects, particularly subgroup effects. METHODS: We pooled individual patient data from septic shock trials investigating the adjunctive use of intravenous hydrocortisone.

A Genome-Wide Association Study of Serum Metabolite Profiles in Septic Shock Patients.

Objectives: We sought to assess whether genetic associations with metabolite concentrations in septic shock patients could be used to identify pathways of potential importance for understanding sepsis pathophysiology.

Design: Retrospective multicenter cohort studies of septic shock patients.

Setting: All participants who were admitted to 27 participating hospital sites in three countries (Australia, New Zealand, and the United Kingdom) were eligible for inclusion.

free spectral unmixing with periodic absorbance changes: application for auto-calibrated intraoperative functional brain mapping.

Spectral unmixing designates techniques that allow to decompose measured spectra into linear or non-linear combination of spectra of all targets (endmembers). This technique was initially developed for satellite applications, but it is now also widely used in biomedical applications. However, several drawbacks limit the use of these techniques with standard optical devices like RGB cameras.

EARLY PERSISTENT LYMPHOPENIA AND RISK OF DEATH IN CRITICALLY ILL PATIENTS WITH AND WITHOUT SEPSIS.

Purpose: To examine the relationship of early persistent lymphopenia with hospital survival in critically ill patients with and without sepsis to assess whether it can be considered a treatable trait. Methods: Retrospective database analysis of patients with nonelective admission to intensive care units (ICUs) during January 2015 to December 2018. Patients were classified as having sepsis if the Acute Physiology and Chronic Health Evaluation III admission diagnostic code included sepsis or coded for an infection combined with a Sequential Organ Failure Assessment score of ≥2.

Spatial and seasonal variation in thermal sensitivity within North American bird species.

Responses of wildlife to climate change are typically quantified at the species level, but physiological evidence suggests significant intraspecific variation in thermal sensitivity given adaptation to local environments and plasticity required to adjust to seasonal environments. Spatial and temporal variation in thermal responses may carry important implications for climate change vulnerability; for instance, sensitivity to extreme weather may increase in specific regions or seasons. Here, we leverage high-resolution observational data from eBird to understand regional and seasonal variation in thermal sensitivity for 21 bird species.

Supporting evidence for an "arterial pump" venous return mechanism in humans.

Blood flow in large veins is dependent on arterial-atrial pressure gradients and pumping mechanisms in concert with valve recruitment. Classic descriptions of muscle and respiratory pumps describe venous transmural pressure changes that cause flow. Not often considered is the transmission of pulsatile energy from arteries to veins directly adjacent to each other.

Blood Pressure Management Goals in Critically Ill Aneurysmal Subarachnoid Hemorrhage Patients in Australia and New Zealand.

Introduction: Blood pressure (BP) management is common in patients with aneurysmal subarachnoid hemorrhage (SAH) admitted to an intensive care unit. However, the practice patterns of BP management (timing, dose, and duration) have not been studied locally.

Methods: This post hoc analysis explored BP management goals (defined as the setting of a minimum systolic BP target or application of induced hypertension) in patients enrolled into the PROMOTE-SAH study in eleven neurosurgical centers in Australia and New Zealand.

Diversity and Scale: Genetic Architecture of 2,068 Traits in the VA Million Veteran Program.

Genome-wide association studies (GWAS) have underrepresented individuals from non-European populations, impeding progress in characterizing the genetic architecture and consequences of health and disease traits. To address this, we present a population-stratified phenome-wide GWAS followed by a multi-population meta-analysis for 2,068 traits derived from electronic health records of 635,969 participants in the Million Veteran Program (MVP), a longitudinal cohort study of diverse U.S.

Time Management Strategies of Rock Climbers in World Cup Bouldering Finals.

Competitive rock climbing recently made its Olympic debut, but minimal published research exists regarding training and competition strategies. Time management strategies define the structured approach climbers take in bouldering competitions to successfully obtain a "top" or a "zone" hold. During finals rounds of the International Federation of Sport Climbing bouldering competitions, climbers are allotted 240 s to complete a boulder.

Heating-induced peripheral limb microvascular vasodilation reduces arterial wave reflection.

Arterial wave reflection augments cardiac afterload increasing myocardial demands. Mathematical models and comparative physiology suggest that the lower limbs are the primary source of reflected waves; however, in vivo human evidence corroborating these observations is lacking. This study was designed to determine whether the vasculature of the lower or upper limbs contributes more to wave reflection.