scholarly journals Persisting lung pathogenesis and minimum residual virus in hamster after acute COVID-19

2021 ◽  
Author(s):  
Lunzhi Yuan ◽  
Huachen Zhu ◽  
Ming Zhou ◽  
Jian Ma ◽  
Rirong Chen ◽  
...  
Keyword(s):  
Minimum Residual ◽  
Lung Pathogenesis

Model Characterization of Pulmonary Arterial Hypertension: Analysis of Lung Pathology with Respect to Human Disease

2020 ◽  
Author(s):  
◽  
Eptisam lambu
Keyword(s):  
Pulmonary Arterial Hypertension ◽  
Arterial Hypertension ◽  
Human Disease ◽  
Vascular Remodeling ◽  
Vascular Wall ◽  
Lung Pathology ◽  
Pulmonary Arterial ◽  
Lung Pathogenesis ◽  
Arterial Endothelial Cells

Pulmonary arterial hypertension (PAH) is a rare multifactorial disease characterized by abnormal high blood pressure in the pulmonary artery, or increased pulmonary vascular resistance (PVR), caused by obstruction in the small arteries of the lung. Increased PVR is also thought to be caused by abnormal vascular remodeling, due to thickening of the pulmonary vascular wall resulting from significant hypertrophy of pulmonary arterial smooth-muscle cells (PASMCs) and increased proliferation/impaired apoptosis of pulmonary arterial endothelial cells (PAECs). Herein, we investigated the mechanisms and explored molecular pathways mediating the lung pathogenesis in two PAH rat models: Monocrotaline (MCT) and Sugen5416/Hypoxia (SuHx). We analyzed these disease models to determine where the vasculature shows the most severe PAH pathology and which model best recapitulates the human disease. We investigated the role vascular remodeling, hypoxia, cell proliferation, apoptosis, DNA damage and inflammation play in the pathogenesis of PAH. Neither model recapitulated all features of the human disease, however each model presented with some of the pathology seen in PAH patients.

scholarly journals A Novel Single-Terminal Fault Location Method for AC Transmission Lines in a MMC-HVDC-Based AC/DC Hybrid System

Energies ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 2066 ◽  
Author(s):  
Shimin Xue ◽  
Junchi Lu ◽  
Chong Liu ◽  
Yabing Sun ◽  
Baibing Liu ◽  
...  
Keyword(s):  
Transmission Lines ◽  
Fault Location ◽  
Control Strategies ◽  
Linear Regression Analysis ◽  
Location Method ◽  
Fault Resistance ◽  
Ac Networks ◽  
Minimum Residual ◽  
Ac Transmission ◽  
Location Methods

Accurate and reliable fault location method for alternating current (AC) transmission lines is essential to the fault recovery. MMC-based converter brings exclusive non-linear characteristics to AC networks under single-phase-to-ground faults, thus influencing the performance of the fault location method. Fault characteristics are related to the control strategies of the converter. However, the existing fault location methods do not take the control strategies into account, with further study being required to solve this problem. The influence of the control strategies to the fault compound sequence network is analyzed in this paper first. Then, a unique boundary condition that the fault voltage and negative-sequence fault current merely meet the direct proportion linear relationship at the fault point, is derived. Based on these, a unary linear regression analysis is performed, and the fault can be located according to the minimum residual sum function principle. The effectiveness of the proposed method is verified by PSCAD/EMTDC simulation platform. A large number of simulation results are used to verify the advantages on sampling frequency, fault resistance, and fault distance. More importantly, it provides a higher ranging precision and has extensive applicability.

A Practical Computing Method for Residual Area of Rebar Cross-Sections under Carbonation Induced Corrosion

2012 ◽  
Vol 166-169 ◽  
pp. 1895-1899
Author(s):  
Xiao Gang Wang ◽  
De Ming Zhong
Keyword(s):  
Cross Sections ◽  
Laser Scanning ◽  
Major Axis ◽  
Structural Deterioration ◽  
Minimum Residual ◽  
Degree Of Confidence ◽  
Conservative Approximation ◽  
Rc Slabs ◽  
Computing Method ◽  
Geometric Measurement

Area loss of severely weakened rebar cross sections is a crucial variable in assessment of structural deterioration for corroded concrete structures, which is hard to be measured or estimated precisely in conventional methods. In this paper, rebar samples were taken from naturally corroded RC slabs. Their virtual models were built using 3D laser scanning technique to facilitate geometric measurement. From these models seriously weakened sections were screened out as analyzing samples, and residual areas as well as profiles of the cross-sections were derived and investigated consequently. Shown by the results, corrosion was non-uniformly distributed on rebar surface, and profiles of the residual cross-sections can hardly be formulated efficiently. However, they can be simplified into ellipse with minor axis of minimum residual diameter and major axis of diameter in perpendicular direction. This model has been proved to give an conservative approximation of residual sectional area with 4.27% underestimation and 89.2% degree of confidence.

scholarly journals A PRECONDITIONED METHOD FOR THE SOLUTION OF THE ROBBINS PROBLEM FOR THE HELMHOLTZ EQUATION

2010 ◽  
Vol 52 (1) ◽  
pp. 87-100 ◽  
Author(s):  
JIANG LE ◽  
HUANG JIN ◽  
XIAO-GUANG LV ◽  
QING-SONG CHENG
Keyword(s):  
Linear System ◽  
Helmholtz Equation ◽  
Analytical Formula ◽  
System Of Equations ◽  
Two Dimensional ◽  
Sparse System ◽  
Sine Transform ◽  
Minimum Residual ◽  
Preconditioned Matrix ◽  
Preconditioned Iterative

AbstractA preconditioned iterative method for the two-dimensional Helmholtz equation with Robbins boundary conditions is discussed. Using a finite-difference method to discretize the Helmholtz equation leads to a sparse system of equations which is too large to solve directly. The approach taken in this paper is to precondition this linear system with a sine transform based preconditioner and then solve it using the generalized minimum residual method (GMRES). An analytical formula for the eigenvalues of the preconditioned matrix is derived and it is shown that the eigenvalues are clustered around 1 except for some outliers. Numerical results are reported to demonstrate the effectiveness of the proposed method.

scholarly journals COVID-19-related anosmia is associated with viral persistence and inflammation in human olfactory epithelium and brain infection in hamsters

2021 ◽  
pp. eabf8396
Author(s):  
Guilherme Dias de Melo ◽  
Françoise Lazarini ◽  
Sylvain Levallois ◽  
Charlotte Hautefort ◽  
Vincent Michel ◽  
...  
Keyword(s):  
Olfactory Epithelium ◽  
Cell Types ◽  
Brain Infection ◽  
Olfactory Neuroepithelium ◽  
Optimal Medical Management ◽  
Infected Cells ◽  
Multiple Cell ◽  
Lung Pathogenesis ◽  
Taste Dysfunction

Whereas recent investigations have revealed viral, inflammatory and vascular factors involved in SARS-CoV-2 lung pathogenesis, the pathophysiology of neurological disorders in COVID-19 remains poorly understood. Olfactory and taste dysfunction are common in COVID-19, especially in mildly symptomatic patients. Here, we conducted a virologic, molecular, and cellular study of the olfactory neuroepithelium of seven patients with COVID-19 presenting with acute loss of smell. We report evidence that the olfactory neuroepithelium may be a major site of SARS-CoV2 infection with multiple cell types, including olfactory sensory neurons, support cells, and immune cells, becoming infected. SARS-CoV-2 replication in the olfactory neuroepithelium was associated with local inflammation. Furthermore, we showed that SARS-CoV-2 induced acute anosmia and ageusia in golden Syrian hamsters, lasting as long as the virus remained in the olfactory epithelium and the olfactory bulb. Finally, olfactory mucosa sampling from patients showing long-term persistence of COVID-19-associated anosmia revealed the presence of virus transcripts and of SARS-CoV-2-infected cells, together with protracted inflammation. SARS-CoV-2 persistence and associated inflammation in the olfactory neuroepithelium may account for prolonged or relapsing symptoms of COVID-19, such as loss of smell, which should be considered for optimal medical management of this disease.

scholarly journals Liquid biopsy in NSCLC: a new challenge in radiation therapy

2021 ◽  
Author(s):  
Annarita Perillo ◽  
Mohamed Vincenzo Agbaje Olufemi ◽  
Jacopo De Robbio ◽  
Rossella Margherita Mancuso ◽  
Anna Roscigno ◽  
...  
Keyword(s):  
Lung Cancer ◽  
Liquid Biopsy ◽  
Residual Disease ◽  
Biological Fluids ◽  
Circulating Tumor Dna ◽  
Minimum Residual ◽  
Nsclc Patients ◽  
Choice Of Therapy ◽  
Tumor Dna

Lung cancer is the most common cancer and the leading cause of cancer mortality worldwide. To date, tissue biopsy has been the gold standard for the diagnosis and the identification of specific molecular mutations, to guide choice of therapy. However, this procedure has several limitations. Liquid biopsy could represent a solution to the intrinsic limits of traditional biopsy. It can detect cancer markers such as circulating tumor DNA or RNA (ctDNA, ctRNA), and circulating tumor cells, in plasma, serum or other biological fluids. This procedure is minimally invasive, reproducible and can be used repeatedly. The main clinical applications of liquid biopsy in non-small cell lung cancer (NSCLC) patients are the early diagnosis, stratification of the risk of relapse, identification of mutations to guide application of targeted therapy and the evaluation of the minimum residual disease. In this review, the current role of liquid biopsy and associated markers in the management of NSCLC patients was analyzed, with emphasis on ctDNA and CTCs, and radiotherapy.

Thermomechanical Simulation of Single Splat Solidification and Cooling in Plasma Spray Forming

2010 ◽  
Vol 102-104 ◽  
pp. 719-723
Author(s):  
Liang Rong Zhu ◽  
Hao Ping Zeng ◽  
Wen Ji Xu ◽  
Hong You Li
Keyword(s):  
Residual Stress ◽  
Plasma Spray ◽  
Steel Substrate ◽  
Element Model ◽  
Spray Forming ◽  
Plasma Spray Forming ◽  
Initial Stage ◽  
Minimum Residual ◽  
Thermomechanical Simulation ◽  
Stress States

Mechanical strength and service life of the coatings manufactured by plasma spray forming are significantly reduced by residual stresses. A 2D finite element model constructed for temperature and residual stress simulation of a single stainless steel splat solidifying and cooling on the carbon steel substrate is presented in this paper. Simulated results show that the temperature of the splat rim is higher than that of the central part during the initial stage of solidification, and the temperature difference between the two parts reverse thereafter. The minimum residual stress locates at the rim of the top surface of the splat, and the maximum residual stress, which decreases when the substrate is preheated to a higher temperature, situates at the rim of the interface. Stresses appear as tensile stresses within the splat and compressive stresses within the substrate. The research can provide quantitative understanding of the temperature and residual stress states at the splat level.

Sign in / Sign up

Export Citation Format

Share Document