6 research outputs found

    Inverse problem and multi-compartment lung model for the estimation of lung airway resistance throughout the bronchial tree, An

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    Includes bibliographical references.2022 Fall.Mechanical ventilation is a vital treatment for patients with respiratory failure, but mechanically ventilated patients are also at risk of ventilator-induced lung injury. Optimal ventilator settings to prevent such injury could be guided by knowledge of the airway resistance throughout the lung. While the ventilator provides a single value estimating the total airway resistance of the patient, in reality the airway resistance varies along the bronchial tree. Multiple literature sources reveal a wide range of clinically used values for airway resistance along the bronchial tree, motivating an investigation to estimate the values of airway resistance in the alveolar tree and the relationship to disease state. In this work, we introduce a multi-compartment asymmetric lung model based on resistor-capacitor circuits by using an analogy between electric circuits and the human lungs. A method for solving the inverse problem of computing the vector of airway resistance values in the alveolar tree is presented. The method uses a linear least squares optimization approach with several constraints. First, a symmetric lung model that makes use of parameters supplied by the mechanical ventilator of patients with acute respiratory distress syndrome (ARDS) is used. We then generalize the model to an asymmetric lung model. The asymmetric model takes regional information data from electrical impedance tomography, a medical imaging technique, and converts them to time dependent lung airway volumes. The linear least squares optimization inverse problem is embedded in an iterative method to update unknown parameters of the forward problem for the asymmetric case

    Assurance Arguments for the Non-Graphically-Inclined: Two Approaches

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    We introduce and discuss two approaches to presenting assurance arguments. One approach is based on a monograph structure, while the other is based on a tabular structure. In today's research and academic setting, assurance cases often use a graphical notation; however for people who are not graphically inclined, these notations can be difficult to read. This document proposes, outlines, explains, and presents examples of two non-graphical assurance argument notations that may be appropriate for non-graphically-inclined readers and also provide argument writers with freedom to add details and manipulate an argument in multiple ways

    Chromosome Xq23 is associated with lower atherogenic lipid concentrations and favorable cardiometabolic indices

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    Abstract Autosomal genetic analyses of blood lipids have yielded key insights for coronary heart disease (CHD). However, X chromosome genetic variation is understudied for blood lipids in large sample sizes. We now analyze genetic and blood lipid data in a high-coverage whole X chromosome sequencing study of 65,322 multi-ancestry participants and perform replication among 456,893 European participants. Common alleles on chromosome Xq23 are strongly associated with reduced total cholesterol, LDL cholesterol, and triglycerides (min P = 8.5 × 10−72), with similar effects for males and females. Chromosome Xq23 lipid-lowering alleles are associated with reduced odds for CHD among 42,545 cases and 591,247 controls (P = 1.7 × 10−4), and reduced odds for diabetes mellitus type 2 among 54,095 cases and 573,885 controls (P = 1.4 × 10−5). Although we observe an association with increased BMI, waist-to-hip ratio adjusted for BMI is reduced, bioimpedance analyses indicate increased gluteofemoral fat, and abdominal MRI analyses indicate reduced visceral adiposity. Co-localization analyses strongly correlate increased CHRDL1 gene expression, particularly in adipose tissue, with reduced concentrations of blood lipids

    Whole Genome Sequencing Identifies CRISPLD2 as a Lung Function Gene in Children With Asthma

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    Chromosome Xq23 is associated with lower atherogenic lipid concentrations and favorable cardiometabolic indices

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