Background: Timely recognition of acute ischemic stroke (AIS) is essential to identify patients who may be eligible for acute intervention. Protocols to streamline systems-based care, such as "stroke alerts" in the emergency department (ED) can safely reduce time-to-care while enhancing safety. However, clinician adherence to stroke alert criteria is poorly described.
View Article and Find Full Text PDFEnantiornithes are the most successful early-diverging avian clade, their fossils revealing important information regarding the structure of Cretaceous avifaunas and the parallel refinement of flight alongside the ornithuromorph lineage that includes modern birds. The most diverse recognized family of Early Cretaceous enantiornithines is the Bohaiornithidae, known from the Jehol Biota in northeastern China. Members of this clade enhance our understanding of intraclade morphological diversity and elucidate the independent evolution of this unique lineage.
View Article and Find Full Text PDFCreating a sustainable residency research program is necessary to develop a sustainable research pipeline, as highlighted by the recent Society for Academic Emergency Medicine 2024 Consensus Conference. We sought to describe the implementation of a novel, immersive research program for first-year emergency medicine residents. We describe the curriculum development, rationale, implementation process, and lessons learned from the implementation of a year-long research curriculum for first-year residents.
View Article and Find Full Text PDFThe transcription factor MEF2C plays a critical role in the development of the linear heart tube, but the specific transcriptional networks controlled by MEF2C remain largely undefined. To address this, we performed combined single-nucleus RNA-and ATAC-sequencing on wild type and MEF2C-null embryos at distinct stages of development. We identified a broadly "posteriorized" cardiac gene signature and chromatin landscape throughout the heart tube in the absence of MEF2C.
View Article and Find Full Text PDFEnantiornithines were the most diverse group of birds during the Cretaceous, comprising over half of all known species from this period. The fossil record and subsequently our knowledge of this clade is heavily skewed by the wealth of material from Lower Cretaceous deposits in China. In contrast, specimens from Upper Cretaceous deposits are rare and typically fragmentary, yet critical for understanding the extinction of this clade across the K-Pg boundary.
View Article and Find Full Text PDFDiet is one of the most important aspects of an animal's ecology, as it reflects direct interactions with other organisms and shapes morphology, behavior, and other life history traits. Modern birds (Neornithes) have a highly efficient and phenotypically plastic digestive system, allowing them to utilize diverse trophic resources, and digestive function has been put forth as a factor in the selectivity of the end-Cretaceous mass extinction, in which only neornithine dinosaurs survived. Although diet is directly documented in several early-diverging avian lineages, only a single specimen preserves evidence of diet in Enantiornithes, the dominant group of terrestrial Cretaceous birds.
View Article and Find Full Text PDFCellular electrophysiology is the foundation of many fields, from basic science in neurology, cardiology, oncology to safety critical applications for drug safety testing, clinical phenotyping, etc. Patch-clamp voltage clamp is the gold standard technique for studying cellular electrophysiology. Yet, the quality of these experiments is not always transparent, which may lead to erroneous conclusions for studies and applications.
View Article and Find Full Text PDFObjectives: In the United States, studies are inconclusive regarding the indications for polyvalent antivenom administration for crotaline envenomation. We compared polyvalent antivenom administration versus observation used at 2 separate institutions. We hypothesized that deferring antivenom leads to increased hospital length of stay and surgical interventions.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
June 2024
Hydrogen isotope ratios (δH) represent an important natural tracer of metabolic processes, but quantitative models of processes controlling H-fractionation in aquatic photosynthetic organisms are lacking. Here, we elucidate the underlying physiological controls of H/H fractionation in algal lipids by systematically manipulating temperature, light, and CO(aq) in continuous cultures of the haptophyte . We analyze the hydrogen isotope fractionation in alkenones (α), a class of acyl lipids specific to this species and other haptophyte algae.
View Article and Find Full Text PDFPeople often modify the shoreline to mitigate erosion and protect property from storm impacts. The 2 main approaches to modification are gray infrastructure (e.g.
View Article and Find Full Text PDFAll new drugs must go through preclinical screening tests to determine their proarrhythmic potential. While these assays effectively filter out dangerous drugs, they are too conservative, often misclassifying safe compounds as proarrhythmic. In this study, we attempt to address this shortcoming with a novel, medium-throughput drug-screening approach: we use an automated patch-clamp system to acquire optimized voltage clamp (VC) and action potential (AP) data from human induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) at several drug concentrations (baseline, 3×, 10× and 20× the effective free plasma concentrations).
View Article and Find Full Text PDFHuman induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) offer potential as an in vitro model for studying drug cardiotoxicity and patient-specific cardiovascular disease. The inherent electrophysiological heterogeneity of these cells limits the depth of insights that can be drawn from well-designed experiments. In this review, we provide our perspective on some sources and the consequences of iPSC-CM heterogeneity.
View Article and Find Full Text PDFHuman induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) are a promising tool to study arrhythmia-related factors, but the variability of action potential (AP) recordings from these cells limits their use as an in vitro model. In this study, we use recently published brief (10 s), dynamic voltage-clamp (VC) data to provide mechanistic insights into the ionic currents contributing to AP heterogeneity; we call this approach rapid ionic current phenotyping (RICP). Features of this VC data were correlated to AP recordings from the same cells, and we used computational models to generate mechanistic insights into cellular heterogeneity.
View Article and Find Full Text PDFBackground: Overuse of sedation and anesthesia causes delays in gastrojejunostomy tube (GJ) exchanges, increased risk of complications, unnecessary use of resources, preventable hospital admissions, and an adverse impact on patient and family experience. Our hospital was over-utilizing sedation and anesthesia, and we aimed to decrease this use from 78% to 20% within two years.
Methods: An interdisciplinary quality improvement team comprehensively evaluated current processes for GJ tube exchanges through a retrospective chart review for baseline data with prospective time series analysis after improvement implementation.
Molecular signaling networks drive a diverse range of cellular decisions, including whether to proliferate, how and when to die, and many processes in between. Such networks often connect hundreds of proteins, genes, and processes. Understanding these complex networks is aided by computational modeling, but these tools require extensive programming knowledge.
View Article and Find Full Text PDFBackground: Communities of practice could contribute to transformations in health professions education to meet complex and emerging challenges. However, little is known about the underlying mechanisms of communities of practice in this setting, and how context influences outcomes.
Objective: To understand when, why and how communities of practice with health professions education faculty work to facilitate higher education change.
Am J Physiol Heart Circ Physiol
February 2024
Cardiac ion currents may compensate for each other when one is compromised by a congenital or drug-induced defect. Such redundancy contributes to a robust repolarization reserve that can prevent the development of lethal arrhythmias. Most efforts made to describe this phenomenon have quantified contributions by individual ion currents.
View Article and Find Full Text PDFPurpose: The objective of this report was to identify the main mechanisms of home-based remote monitoring programs for cardiac rehabilitation (RM CR) and examine how these mechanisms vary by context.
Methods: This was a systematic review using realist synthesis. To be included, articles had to be published in English between 2010 and November 2020 and contain specific data related to mechanisms of effect of programs.
As a renewable, easily accessible, human-derived model, human induced pluripotent stem cell derived cardiomyocytes (iPSC-CMs) are a promising tool for studying arrhythmia-related factors, including cardiotoxicity and congenital proarrhythmia risks. An oft-mentioned limitation of iPSC-CMs is the abundant cell-to-cell variability in recordings of their electrical activity. Here, we develop a new method, rapid ionic current phenotyping (RICP), that utilizes a short (10 s) voltage clamp protocol to quantify cell-to-cell heterogeneity in key ionic currents.
View Article and Find Full Text PDFWe extend a recently proposed kinetic theory of virus capsid assembly based on Model A kinetics and study the dynamics of the interconversion of virus capsids of different sizes triggered by a quench, that is, by sudden changes in the solution conditions. The work is inspired by in vitro experiments on functionalized coat proteins of the plant virus cowpea chlorotic mottle virus, which undergo a reversible transition between two different shell sizes (T = 1 and T = 3) upon changing the acidity and salinity of the solution. We find that the relaxation dynamics are governed by two time scales that, in almost all cases, can be identified as two distinct processes.
View Article and Find Full Text PDFAims: Human-induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) have become an essential tool to study arrhythmia mechanisms. Much of the foundational work on these cells, as well as the computational models built from the resultant data, has overlooked the contribution of seal-leak current on the immature and heterogeneous phenotype that has come to define these cells. The aim of this study is to understand the effect of seal-leak current on recordings of action potential (AP) morphology.
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