Mathematical medicine and biology : a journal of the IMA最新文献

On the large time behaviour of the solutions of an evolutionary-epidemic system with spatial dispersal. 关于具有空间分散性的进化-流行系统解的大时间行为。

Mathematical medicine and biology : a journal of the IMA Pub Date : 2024-11-13 DOI: 10.1093/imammb/dqae022

A Ducrot, D Manceau, A Sylla

引用次数: 0

Polymer-Interface-Tissue Model to Estimate Leachable Release from Medical Devices. 估算医疗器械可渗漏释放的聚合物-界面-组织模型。

Mathematical medicine and biology : a journal of the IMA Pub Date : 2024-10-18 DOI: 10.1093/imammb/dqae020

Martin L Tanaka, David M Saylor, Robert M Elder

{"title":"Polymer-Interface-Tissue Model to Estimate Leachable Release from Medical Devices.","authors":"Martin L Tanaka, David M Saylor, Robert M Elder","doi":"10.1093/imammb/dqae020","DOIUrl":"https://doi.org/10.1093/imammb/dqae020","url":null,"abstract":"The ability to predict clinically relevant exposure to potentially hazardous compounds that can leach from polymeric components can help reduce testing needed to evaluate the biocompatibility of medical devices. In this manuscript, we compare two physics-based exposure models: 1) a simple, one-component model that assumes the only barrier to leaching is the migration of the compound through the polymer matrix and 2) a more clinically relevant, two-component model that also considers partitioning across the polymer-tissue interface and migration in the tissue away from the interface. Using data from the literature, the variation of the model parameters with key material properties were established, enabling the models to be applied to a wide range of combinations of leachable compound, polymer matrix and tissue type. Exposure predictions based on the models suggest that the models are indistinguishable over much of the range of clinically relevant scenarios. However, for systems with low partitioning and/or slow tissue diffusion, the two-component model predicted up to three orders of magnitude less mass release over the same time period. Thus, despite the added complexity, in some scenarios it can be beneficial to use the two-component model to provide more clinically relevant estimates of exposure to leachable substances from implanted devices.","PeriodicalId":94130,"journal":{"name":"Mathematical medicine and biology : a journal of the IMA","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142484533","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Effect of diffusivity of amyloid beta monomers on the formation of senile plaques. 淀粉样 beta 单体的扩散性对老年斑形成的影响

Mathematical medicine and biology : a journal of the IMA Pub Date : 2024-10-15 DOI: 10.1093/imammb/dqae019

Andrey V Kuznetsov

{"title":"Effect of diffusivity of amyloid beta monomers on the formation of senile plaques.","authors":"Andrey V Kuznetsov","doi":"10.1093/imammb/dqae019","DOIUrl":"https://doi.org/10.1093/imammb/dqae019","url":null,"abstract":"Alzheimer's disease (AD) presents a perplexing question: why does its development span decades, even though individual amyloid beta (Aβ) deposits (senile plaques) can form rapidly in as little as 24 hours, as recent publications suggest? This study investigated whether the formation of senile plaques can be limited by factors other than polymerization kinetics alone. Instead, their formation may be limited by the diffusion-driven supply of Aβ monomers, along with the rate at which the monomers are produced from amyloid precursor protein (APP) and the rate at which Aβ monomers undergo degradation. A mathematical model incorporating the nucleation and autocatalytic process (via the Finke-Watzky model), as well as Aβ monomer diffusion, was proposed. The obtained system of partial differential equations was solved numerically, and a simplified version was investigated analytically. The computational results predicted that it takes approximately 7 years for Aβ aggregates to reach a neurotoxic concentration of 50 μM. Additionally, a sensitivity analysis was performed to examine how the diffusivity of Aβ monomers and their production rate impact the concentration of Aβ aggregates.","PeriodicalId":94130,"journal":{"name":"Mathematical medicine and biology : a journal of the IMA","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142484531","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Genesis of Intimal Thickening Due to Hemodynamical Shear Stresses. 血流动力学剪切应力导致内膜增厚的成因

Mathematical medicine and biology : a journal of the IMA Pub Date : 2024-10-15 DOI: 10.1093/imammb/dqae018

Avishek Mukherjee, Navid Mohammad Mirzaei, Pak-Wing Fok

{"title":"Genesis of Intimal Thickening Due to Hemodynamical Shear Stresses.","authors":"Avishek Mukherjee, Navid Mohammad Mirzaei, Pak-Wing Fok","doi":"10.1093/imammb/dqae018","DOIUrl":"https://doi.org/10.1093/imammb/dqae018","url":null,"abstract":"This paper investigates intimal growth in arteries, induced by hemodynamical shear stress, through finite element simulation using the FEniCS computational environment. In our model, the growth of the intima depends on cross section geometry and shear stress. In this work, the arterial wall is modeled as three distinct layers: the intima, the media, and the adventitia, each with different mechanical properties. We assume that the cross section of the vessel does not change in the axial direction. We further assume that the blood flow is steady, non-turbulent, and unidirectional. Blood flow induces shear stress on the endothelium and stimulates the release of Platelet Derived Growth Factor (PDGF) which drives the growth. We simulate intimal growth for three distinct arterial cross section geometries. We show that the qualitative nature of intimal thickening varies depending on arterial geometry. For cross section geometries that are annular, the growth of the intima is uniform in the angular direction, and the endothelium stays circular as the intima grows. For non-annular cross section geometries, thicker intimas grow more compared to thinner ones, shear stress and intimal thickening are negatively correlated with the distance from the flow center, where the flow velocity is maximal. Over time, the maxima and minima of the curvature increase and decrease respectively, the PDGF concentration increases, and the lumen becomes more polygonal. The model provides a framework for coupling hemodynamics simulations to mathematical descriptions of atherosclerosis, both of which have been modeled separately in great detail.","PeriodicalId":94130,"journal":{"name":"Mathematical medicine and biology : a journal of the IMA","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142484532","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Modelling the influence of vitamin D and probiotic supplementation on the microbiome and immune response. 模拟维生素 D 和益生菌补充剂对微生物组和免疫反应的影响。

Mathematical medicine and biology : a journal of the IMA Pub Date : 2024-10-01 DOI: 10.1093/imammb/dqae017

S J Franks, J L Dunster, S R Carding, J M Lord, M Hewison, P C Calder, J R King

{"title":"Modelling the influence of vitamin D and probiotic supplementation on the microbiome and immune response.","authors":"S J Franks, J L Dunster, S R Carding, J M Lord, M Hewison, P C Calder, J R King","doi":"10.1093/imammb/dqae017","DOIUrl":"https://doi.org/10.1093/imammb/dqae017","url":null,"abstract":"The intestinal microbiota play a critical role in human health and disease, maintaining metabolic and immune/inflammatory health, synthesising essential vitamins and amino acids and maintaining intestinal barrier integrity. The aim of this paper is to develop a mathematical model to describe the complex interactions between the microbiota, vitamin D/vitamin D receptor (VDR) pathway, epithelial barrier and immune response in order to understand better the effects of supplementation with probiotics and vitamin D. This is motivated by emerging data indicating the beneficial effects of vitamin D and probiotics individually and when combined. We propose a system of ordinary differential equations determining the time evolution of intestinal bacterial populations, concentration of the VDR:1,25(OH)2D complex in epithelial and immune cells, the epithelial barrier and the immune response. The model shows that administration of probiotics and/or vitamin D upregulates the VDR complex, which enhances barrier function and protects against intestinal inflammation. The model also suggests co-supplementation to be superior to individual supplements. We explore the effects of inflammation on the populations of commensal and pathogenic bacteria and the vitamin D/VDR pathway and discuss the value of gathering additional experimental data motivated by the modelling insights.","PeriodicalId":94130,"journal":{"name":"Mathematical medicine and biology : a journal of the IMA","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142368080","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Inference on an interacting diffusion system with application to in vitro glioblastoma migration (publication template). 应用于体外胶质母细胞瘤迁移的交互扩散系统推论。

Mathematical medicine and biology : a journal of the IMA Pub Date : 2024-09-16 DOI: 10.1093/imammb/dqae010

Gustav Lindwall, Philip Gerlee

引用次数: 0

Beyond SIRD models: a novel dynamic model for epidemics, relating infected with entries to health care units and application for identification and restraining policy. 超越 SIRD 模型：一种新型的流行病动态模型，将感染者与进入医疗单位的人员联系起来，并应用于识别和限制政策。

Mathematical medicine and biology : a journal of the IMA Pub Date : 2024-09-16 DOI: 10.1093/imammb/dqae008

Christos Tsiliyannis

{"title":"Beyond SIRD models: a novel dynamic model for epidemics, relating infected with entries to health care units and application for identification and restraining policy.","authors":"Christos Tsiliyannis","doi":"10.1093/imammb/dqae008","DOIUrl":"10.1093/imammb/dqae008","url":null,"abstract":"Epidemic models of susceptibles, exposed, infected, recovered and deceased (SΕIRD) presume homogeneity, constant rates and fixed, bilinear structure. They produce short-range, single-peak responses, hardly attained under restrictive measures. Tuned via uncertain I,R,D data, they cannot faithfully represent long-range evolution. A robust epidemic model is presented that relates infected with the entry rate to health care units (HCUs) via population averages. Model uncertainty is circumvented by not presuming any specific model structure, or constant rates. The model is tuned via data of low uncertainty, by direct monitoring: (a) of entries to HCUs (accurately known, in contrast to delayed and non-reliable I,R,D data) and (b) of scaled model parameters, representing population averages. The model encompasses random propagation of infections, delayed, randomly distributed entries to HCUs and varying exodus of non-hospitalized, as disease severity subdues. It closely follows multi-pattern growth of epidemics with possible recurrency, viral strains and mutations, varying environmental conditions, immunity levels, control measures and efficacy thereof, including vaccination. The results enable real-time identification of infected and infection rate. They allow design of resilient, cost-effective policy in real time, targeting directly the key variable to be controlled (entries to HCUs) below current HCU capacity. As demonstrated in ex post case studies, the policy can lead to lower overall cost of epidemics, by balancing the trade-off between the social cost of infected and the economic contraction associated with social distancing and mobility restriction measures.","PeriodicalId":94130,"journal":{"name":"Mathematical medicine and biology : a journal of the IMA","volume":" ","pages":"192-224"},"PeriodicalIF":0.0,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142001625","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Selector of amino-acid scales set. 氨基酸刻度选择器套装。

Mathematical medicine and biology : a journal of the IMA Pub Date : 2024-09-16 DOI: 10.1093/imammb/dqae007

Anton Vrdoljak, Damir Vukičević

{"title":"Selector of amino-acid scales set.","authors":"Anton Vrdoljak, Damir Vukičević","doi":"10.1093/imammb/dqae007","DOIUrl":"10.1093/imammb/dqae007","url":null,"abstract":"Experimental and theoretical properties of amino acids as building blocks of peptides and proteins have been extensively researched. Each such method assigns a number to each amino acid, and one such assignment is called amino-acid scale. Their usage in bioinformatics to explain and predict behaviour of peptides and proteins is of essential value. The number of such scales is very large. There are more than a hundred scales related just to hydrophobicity. A large number of scales can be a computational burden for algorithms that try to define peptide descriptors combining several of these scales. Hence, it is of interest to construct a smaller, but still representative set of scales. Here, we present software that does this. We test it on the set of scales using a database constructed by Kawashima and collaborators and show that it is possible to significantly reduce the number of scales observed without losing much of the information. An algorithm is implemented in C#. As a result, we provide a smaller database that might be a very useful tool for the analyses and construction of new peptides. Another interesting application of this database would be to compare the artificial intelligence construction of peptides having as an input the complete Kawashima database and this reduced one. Obtaining in both cases similar results would give much credibility to the constructs of such AI algorithms.","PeriodicalId":94130,"journal":{"name":"Mathematical medicine and biology : a journal of the IMA","volume":" ","pages":"157-168"},"PeriodicalIF":0.0,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141560650","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Infection spreading in tissue as a reaction-diffusion wave. 感染在组织中以反应-扩散波的形式传播。

Mathematical medicine and biology : a journal of the IMA Pub Date : 2024-09-16 DOI: 10.1093/imammb/dqae009

Saddam Hussain, Moitri Sen, Vitaly Volpert

引用次数: 0

Assessing marginal effects of non-pharmaceutical interventions on the transmission of SARS-CoV-2 across Africa: a hybrid modeling study. 评估非药物干预对 SARS-CoV-2 跨非洲传播的边际效应：混合模型研究

Mathematical medicine and biology : a journal of the IMA Pub Date : 2024-09-16 DOI: 10.1093/imammb/dqae013

Yvette Montcho, Sidoine Dako, Valère Kolawole Salako, Chénangnon Frédéric Tovissodé, Martin Wolkewitz, Romain Glèlè Kakaï

{"title":"Assessing marginal effects of non-pharmaceutical interventions on the transmission of SARS-CoV-2 across Africa: a hybrid modeling study.","authors":"Yvette Montcho, Sidoine Dako, Valère Kolawole Salako, Chénangnon Frédéric Tovissodé, Martin Wolkewitz, Romain Glèlè Kakaï","doi":"10.1093/imammb/dqae013","DOIUrl":"10.1093/imammb/dqae013","url":null,"abstract":"Since 2019, a new strain of coronavirus has challenged global health systems. Due its fragile healthcare systems, Africa was predicted to be the most affected continent. However, past experiences of African countries with epidemics and other factors, including actions taken by governments, have contributed to reducing the spread of SARS-CoV-2. This study aims to assess the marginal impact of non-pharmaceutical interventions in fifteen African countries during the pre-vaccination period. To describe the transmission dynamics and control of SARS-CoV-2 spread, an extended time-dependent SEIR model was used. The transmission rate of each infectious stage was obtained using a logistic model with NPI intensity as a covariate. The results revealed that the effects of NPIs varied between countries. Overall, restrictive measures related to assembly had, in most countries, the largest reducing effects on the pre-symptomatic and mild transmission, while the transmission by severe individuals is influenced by privacy measures (more than $10%$). Countries should develop efficient alternatives to assembly restrictions to preserve the economic sector. This involves e.g. training in digital tools and strengthening digital infrastructures.","PeriodicalId":94130,"journal":{"name":"Mathematical medicine and biology : a journal of the IMA","volume":" ","pages":"225-249"},"PeriodicalIF":0.0,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141857499","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0