scholarly journals Margination of white blood cells: a computational approach by a hydrodynamic phase field model

2016 ◽  
Vol 790 ◽  
pp. 389-406 ◽  
Author(s):  
Wieland Marth ◽  
Sebastian Aland ◽  
Axel Voigt
Keyword(s):  
Reynolds Number ◽  
Blood Cells ◽  
Large Scale ◽  
Field Model ◽  
Single Cells ◽  
White Blood Cells ◽  
Phase Field Model ◽  
Type Model ◽  
Flow Conditions ◽  
Inertia Effects

We numerically investigate margination of white blood cells and demonstrate the dependency on a number of conditions including haematocrit, the deformability of the cells and the Reynolds number. The approach, which is based on a mesoscopic hydrodynamic Helfrich-type model, reproduces previous results, e.g. a decreasing tendency for margination with increasing deformability and a non-monotonic dependency on haematocrit. The consideration of inertia effects, which may be of relevance in various parts of the cardiovascular system, indicates a decreasing tendency for margination with increasing Reynolds number. The effect is discussed by analysing inertial and non-inertial lift forces for single cells under different flow conditions and large-scale two-dimensional simulations of interacting red blood cells and white blood cells in an idealized blood vessel.

Simulation of Ideal Grain Growth Using the Multi-Phase-Field Model

2007 ◽  
Vol 558-559 ◽  
pp. 1177-1181 ◽  
Author(s):  
Philippe Schaffnit ◽  
Markus Apel ◽  
Ingo Steinbach
Keyword(s):  
Grain Size ◽  
Grain Growth ◽  
Phase Field ◽  
Large Scale ◽  
Field Model ◽  
Three Dimensional ◽  
Phase Field Model ◽  
Two Dimensions ◽  
Von Neumann ◽  
Average Grain Size

The kinetics and topology of ideal grain growth were simulated using the phase-field model. Large scale phase-field simulations were carried out where ten thousands grains evolved into a few hundreds without allowing coalescence of grains. The implementation was first validated in two-dimensions by checking the conformance with square-root evolution of the average grain size and the von Neumann-Mullins law. Afterwards three-dimensional simulations were performed which also showed fair agreement with the law describing the evolution of the mean grain size against time and with the results of S. Hilgenfeld et al. in 'An Accurate von Neumann's Law for Three-Dimensional Foams', Phys. Rev. Letters, 86(12)/2685, March 2001. Finally the steady state grain size distribution was investigated and compared to the Hillert theory.

Computer Simulation of Grain Growth in Three Dimensions by the Phase Field Model with Anisotropic Grain-Boundary Mobilities

2007 ◽  
Vol 539-543 ◽  
pp. 2437-2442
Author(s):  
Yoshihiro Suwa ◽  
Yoshiyuki Saito ◽  
Hidehiro Onodera
Keyword(s):  
Grain Boundary ◽  
Grain Growth ◽  
Phase Field ◽  
Large Scale ◽  
Field Model ◽  
Phase Field Model ◽  
High Mobility ◽  
Minor Component ◽  
Three Dimensions ◽  
A Minor

The kinetics and topology of grain growth in three dimensions were simulated using a phase-field model with anisotropic grain-boundary mobilities. In order to perform large scale calculations we applied both modifications of algorithms and parallel coding techniques to the Fan and Chen's phase-field algorithm. Kinetics of abnormal grain growth is presented. It is observed that the grains of a minor component which are at the beginning surrounded preferentially by boundaries of high mobility grow faster than the grains of a major component until the texture reverses completely. Additionally, topological results of grain structures, such as grain size distributions and grain face distributions, are discussed

scholarly journals Prioritizing Causal Risk Factors for Severe COVID-19: An Exhaustive Mendelian Randomization Study

2021 ◽  
Author(s):  
Yitang Sun ◽  
Jingqi Zhou ◽  
Kaixiong Ye
Keyword(s):  
Risk Factors ◽  
Fat Mass ◽  
Blood Cells ◽  
Drug Targets ◽  
Large Scale ◽  
Mendelian Randomization ◽  
White Blood Cells ◽  
Fat Free Mass ◽  
Cell Counts ◽  
Increased Risk

Abstract Identifying causal risk factors for severe coronavirus disease 2019 (COVID-19) is critical for its prevention and treatment. Many associated pre-existing conditions and biomarkers have been reported, but these observational associations suffer from confounding and reverse causation. Here, we perform a large-scale two-sample Mendelian randomization (MR) analysis to evaluate the causal roles of many traits in severe COVID-19. Our results highlight multiple body mass index (BMI)-related traits as risk-increasing: BMI (OR:1.89, 95% CI:1.51–2.37), hip circumference (OR:1.46, 1.15–1.85), and waist circumference (OR:1.82, 1.36–2.43). Our multivariable MR analysis further shows that the BMI-related effect is driven by fat mass (OR:1.63, 1.03–2.58), but not fat-free mass (OR:1.00, 0.61–1.66). Several white blood cell counts are negatively associated with severe COVID-19, including those of neutrophils (OR:0.76, 0.61–0.94), granulocytes (OR:0.75, 0.601–0.93), and myeloid white blood cells (OR:0.77, 0.62–0.96). Furthermore, some circulating proteins are associated with an increased risk of (e.g., zinc-alpha-2-glycoprotein) or protection from severe COVID-19 (e.g., interleukin-3/6 receptor subunit alpha). Our study shows that fat mass and white blood cells underlie the etiology of severe COVID-19. It also identifies risk and protective factors that could serve as drug targets and guide the effective protection of high-risk individuals.

scholarly journals Hematological indices and abnormalities among patients with uncomplicated falciparum malaria in Kosti city of the White Nile State, Sudan: A comparative study

2021 ◽  
Author(s):  
Ahmed M. E. Elkhalifa ◽  
Rashad Abdul-Ghani ◽  
Abdelhakam G. Tamomh ◽  
Nur Eldin Eltaher ◽  
Nada Y. Ali ◽  
...  
Keyword(s):  
Platelet Count ◽  
Falciparum Malaria ◽  
Blood Cells ◽  
Large Scale ◽  
White Blood Cells ◽  
Hematological Indices ◽  
Low Level ◽  
White Nile ◽  
Hb Concentration ◽  
Rbc Count

Abstract Background: Hematological abnormalities are common features in falciparum malaria but vary among different populations across countries. Therefore, we compared hematological indices and abnormalities between Plasmodium falciparum-infected patients and malaria-negative subjects in Kosti city of the White Nile State, Sudan. Methods: A comparative, cross-sectional study was conducted at the Medical Technology Laboratory Unit of Kosti Teaching Hospital from June to December 2018. A total of 392 participants (192 P. falciparum-infected patients and 200 malaria-negative subjects) were recruited in the study. Hematological indices of hemoglobin (Hb), red blood cells (RBCs), white blood cells (WBCs) and platelets were measured and their median values were statistically compared. Results: The majority of P. falciparum-infected patients (64.6%) showed a low-level parasitemia. The median values of Hb concentration, RBC count, mean corpuscular Hb and mean corpuscular Hb concentration were significantly lower in P. falciparum-infected patients, with anemia being significantly higher among infected patients than malaria-negative subjects (60.4% vs. 29.5%, respectively). The median total WBC count was non-significantly higher in P. falciparum-infected patients, with leucopenia being non-significantly different between both groups. The median platelet count was significantly lower in P. falciparum-infected patients, with thrombocytopenia being significantly higher among infected patients than malaria-negative subjects (72.4% vs. 5.0%, respectively).Conclusions: Most falciparum malaria infections among patients in Kosti city of the White Nile State – Sudan are of low-level parasitemia. Nevertheless, falciparum malaria is significantly associated with anemia and thrombocytopenia with lower median values of Hb, RBC count, MCH, MCHC and platelet count in P. falciparum-infected patients than malaria-negative subjects. In contrast, leucopenia is not useful to predict falciparum malaria. Further large-scale studies in community and healthcare settings and inclusion of patients with complicated or severe malaria and those with high parasite densities are recommended.

scholarly journals Influence of Interface Proximity on Precipitation Thermodynamics

Metals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1292
Author(s):  
Kai Wang ◽  
Marc Weikamp ◽  
Mingxuan Lin ◽  
Carina Zimmermann ◽  
Ruth Schwaiger ◽  
...  
Keyword(s):  
Grain Boundary ◽  
Large Scale ◽  
Field Model ◽  
Morphological Changes ◽  
Phase Field Model ◽  
Free Surfaces ◽  
Elastic Mismatch ◽  
Boundary Relaxation ◽  
Multi Phase ◽  
Effective Description

The formation of coherent precipitates is often accompanied by large elastic mismatch stresses, which suppress phase separation. We discuss the presence of interfaces as a mechanism for stress relaxation, which can lead to preferred zones of precipitation. In particular, we discuss the proximity of free surfaces and shear-coupled grain boundaries, for which we can obtain a substantial local energy reduction and predict the influence on the local precipitation thermodynamics. The latter case is accompanied by morphological changes of the grain boundary, which are less suitable for large-scale descriptions. For that purpose, we develop an effective description through an elastic softening inside the grain boundary and map the microscopic grain boundary relaxation to a mesoscopic elastic and phase field model, which also allows generalizing the description to multi-phase situations.

scholarly journals Peripheral Glycolysis in Neurodegenerative Diseases

2020 ◽  
Vol 21 (23) ◽  
pp. 8924 ◽  
Author(s):  
Simon M. Bell ◽  
Toby Burgess ◽  
James Lee ◽  
Daniel J. Blackburn ◽  
Scott P. Allen ◽  
...  
Keyword(s):  
Nervous System ◽  
Neurodegenerative Diseases ◽  
Neurodegenerative Disease ◽  
Blood Cells ◽  
Large Scale ◽  
White Blood Cells ◽  
Peripheral Cells ◽  
Multiple Patients ◽  
Brain And Spinal Cord ◽  
Lateral Sclerosis

Neurodegenerative diseases are a group of nervous system conditions characterised pathologically by the abnormal deposition of protein throughout the brain and spinal cord. One common pathophysiological change seen in all neurodegenerative disease is a change to the metabolic function of nervous system and peripheral cells. Glycolysis is the conversion of glucose to pyruvate or lactate which results in the generation of ATP and has been shown to be abnormal in peripheral cells in Alzheimer’s disease, Parkinson’s disease, and Amyotrophic Lateral Sclerosis. Changes to the glycolytic pathway are seen early in neurodegenerative disease and highlight how in multiple neurodegenerative conditions pathology is not always confined to the nervous system. In this paper, we review the abnormalities described in glycolysis in the three most common neurodegenerative diseases. We show that in all three diseases glycolytic changes are seen in fibroblasts, and red blood cells, and that liver, kidney, muscle and white blood cells have abnormal glycolysis in certain diseases. We highlight there is potential for peripheral glycolysis to be developed into multiple types of disease biomarker, but large-scale bio sampling and deciphering how glycolysis is inherently altered in neurodegenerative disease in multiple patients’ needs to be accomplished first to meet this aim.

scholarly journals Hematological Indices and Abnormalities Among Patients With Uncomplicated Falciparum Malaria in Kosti City of the White Nile State, Sudan: a Comparative Study

2021 ◽  
Author(s):  
Ahmed M. E. Elkhalifa ◽  
Rashad Abdul-Ghani ◽  
Abdelhakam G. Tamomh ◽  
Nur Eldin Eltaher ◽  
Nada Y. Ali ◽  
...  
Keyword(s):  
Platelet Count ◽  
Falciparum Malaria ◽  
Blood Cells ◽  
Large Scale ◽  
White Blood Cells ◽  
Hematological Indices ◽  
Low Level ◽  
White Nile ◽  
Hb Concentration ◽  
Rbc Count

Abstract Background: Hematological abnormalities are common features in falciparum malaria but vary among different populations across countries. Therefore, we compared hematological indices and abnormalities between Plasmodium falciparum-infected patients and malaria-negative subjects in Kosti city of the White Nile State, Sudan. Methods: A comparative, cross-sectional study was conducted at the Medical Technology Laboratory Unit of Kosti Teaching Hospital from June to December 2018. A total of 392 participants (192 P. falciparum-infected patients and 200 malaria-negative subjects) were recruited in the study. Hematological indices of hemoglobin (Hb), red blood cells (RBCs), white blood cells (WBCs) and platelets were measured and their median values were statistically compared.Results: The majority of P. falciparum-infected patients (64.6%) showed a low-level parasitemia. The median values of Hb concentration, RBC count, mean corpuscular Hb and mean corpuscular Hb concentration were significantly lower in P. falciparum-infected patients, with anemia being significantly higher among infected patients than malaria-negative subjects (60.4% vs. 29.5%, respectively). The median total WBC count was non-significantly higher in P. falciparum-infected patients, with leucopenia being non-significantly different between both groups. The median platelet count was significantly lower in P. falciparum-infected patients, with thrombocytopenia being significantly higher among infected patients than malaria-negative subjects (72.4% vs. 5.0%, respectively).Conclusions: Most falciparum malaria infections among patients in Kosti city of the White Nile State – Sudan are of low-level parasitemia. Nevertheless, falciparum malaria is significantly associated with anemia and thrombocytopenia with lower median values of Hb, RBC count, MCH, MCHC and platelet count in P. falciparum-infected patients than malaria-negative subjects. In contrast, leucopenia is not useful to predict falciparum malaria. Further large-scale studies in community and healthcare settings and inclusion of patients with complicated or severe malaria and those with high parasite densities are recommended.

scholarly journals Large Scale Simulation of Dendritic Growth in Pure Undercooled Melt by Phase-field Model.

1999 ◽  
Vol 39 (4) ◽  
pp. 335-340 ◽  
Author(s):  
Seong Gyoon Kim ◽  
Won Tae Kim ◽  
Jae Sang Lee ◽  
Machiko Ode ◽  
Toshio Suzuki
Keyword(s):  
Phase Field ◽  
Dendritic Growth ◽  
Large Scale ◽  
Field Model ◽  
Phase Field Model ◽  
Large Scale Simulation ◽  
Undercooled Melt
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