The probabilistic nature of the ventricular defibrillation threshold (DFT) remains poorly understood. We hypothesized that shock outcome is a function of the amount of myocardium in its vulnerable period (VP). The endocardial surface of five isolated, perfused swine right ventricles was mapped with 477 bipolar electrodes during ventricular fibrillation (VF). Shock parameters and VF cycle length were not significantly different in the successful (S; n = 26) and failed (F; n = 26) trials. At the instant of the shock, the number of sites with 45- to 55-ms recovery was significantly smaller in the S trials than the F trials (P < 0.04). No significant difference in the number of sites with recovery intervals outside the 45- to 55-ms range was seen in S and F shocks. Endocardial action potential showed that a recovery time of 45-55 ms corresponded to the VP spanning -15 to -60 mV in 92% of the regenerative action potentials. We conclude that the probabilistic nature of the DFT is related to the amount of myocardium in its VP.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1152/ajpheart.00742.2002 | DOI Listing |
J Chem Phys
January 2025
Department of Chemistry, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada.
We present an algorithm that combines quantum scattering calculations with probabilistic machine-learning models to predict quantum dynamics rate coefficients for a large number of state-to-state transitions in molecule-molecule collisions much faster than with direct solutions of the Schrödinger equation. By utilizing the predictive power of Gaussian process regression with kernels, optimized to make accurate predictions outside of the input parameter space, the present strategy reduces the computational cost by about 75%, with an accuracy within 5%. Our method uses temperature dependences of rate coefficients for transitions from the isolated states of initial rotational angular momentum j, determined via explicit calculations, to predict the temperature dependences of rate coefficients for other values of j.
View Article and Find Full Text PDFNat Mater
January 2025
State Key Laboratory of Surface Physics, Key Laboratory of Micro and Nano Photonic Structures (MOE), and Department of Physics, Fudan University, Shanghai, China.
Polymorphism, commonly denoting diverse molecular or crystal structures, is crucial in the natural sciences. In van der Waals antiferromagnets, a new type of magnetic polymorphism arises, presenting multiple layer-selective magnetic structures with identical total magnetization. However, resolving and manipulating such magnetic polymorphs remain challenging.
View Article and Find Full Text PDFHealth Econ Rev
January 2025
Department of Pharmacy, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, 230001, China.
Background: The ORIENT-15 double-blind randomized controlled trial demonstrated that the addition of sintilimab to chemotherapy for locally advanced or metastatic oesophageal squamous cell carcinoma (OSCC) resulted in better clinical outcomes. In this analysis, we sought to evaluate the cost-effectiveness of sintilimab as a first-line treatment for locally advanced or metastatic OSCC from a healthcare system perspective in China.
Methods: A partitioned survival model was constructed to perform a cost-effectiveness analysis comparing chemotherapy alone with sintilimab for locally advanced or metastatic OSCC patients.
Curr Microbiol
January 2025
Coastar Therapeutics, San Diego, CA, 92126, USA.
Staphylococcus epidermidis (S. epidermidis) live in different human locations and natural environments. For ribotyping S.
View Article and Find Full Text PDFBrain Behav
January 2025
Research Institute for Health Sciences and Technologies (SABITA), Neuroscience Research Center, Clinical Electrophysiology, Neuroimaging and Neuromodulation Lab, Istanbul Medipol University, Istanbul, Turkey.
Introduction: The neural substrates of reasoning, a cognitive ability we use constantly in daily life, are still unclear. Reasoning can be divided into two types according to how the inference process works and the certainty of the conclusions. In deductive reasoning, certain conclusions are drawn from premises by applying the rules of logic.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!