Mathematical Medicine and Biology-A Journal of the Ima最新文献_第10页

Corrigendum to: A proposed fractional-order Gompertz model and its application to tumour growth data. 提出的分数阶Gompertz模型及其在肿瘤生长数据中的应用的更正。

IF 1.1 4区数学

Mathematical Medicine and Biology-A Journal of the Ima Pub Date : 2018-06-13 DOI: 10.1093/imammb/dqy002

Larisse Bolton, Alain H J J Cloot, Schalk W Schoombie, Jacobus P Slabbert

引用次数: 0

Modelling original antigenic sin in dengue viral infection. 模拟登革热病毒感染的原始抗原原罪。

IF 1.1 4区数学

Mathematical Medicine and Biology-A Journal of the Ima Pub Date : 2018-06-13 DOI: 10.1093/imammb/dqx002

Ryan Nikin-Beers, Stanca M Ciupe

引用次数: 25

Early treatment gains for antibiotic administration and within human host time series data. 早期治疗获得抗生素管理和人类宿主时间序列数据。

IF 1.1 4区数学

Mathematical Medicine and Biology-A Journal of the Ima Pub Date : 2018-06-13 DOI: 10.1093/imammb/dqw025

Todd R Young, Erik M Boczko

{"title":"Early treatment gains for antibiotic administration and within human host time series data.","authors":"Todd R Young, Erik M Boczko","doi":"10.1093/imammb/dqw025","DOIUrl":"https://doi.org/10.1093/imammb/dqw025","url":null,"abstract":"As technological improvements continue to infiltrate and impact medical practice, it has become possible to non-invasively collect dense physiological time series data from individual patients in real time. These advances continue to improve physicians' ability to detect and to treat infections early. One important benefit of early detection and treatment of nascent infections is that it leads to earlier resolution. In response to current and anticipated advances in data capture, we introduce the Early Treatment Gain (ETG) as a measure to quantify this benefit. Roughly, we define the gain to be the limiting ratio: ETG=differential change in time of resolutiondifferential change in treatment time.We study the gain using standard dynamical models and demonstrate its use with time series data from Surgical Intensive Care Unit (SICU) patients facing ventilator associated pneumonia. The main conclusion from the mathematical modelling is that the ETG is always greater than one unless there is an effective immune response, in which case the ETG can be less than one. Using real patient time series data, we observe that the formula derived for a linear model can be applied and that this produces a ETG greater than one.","PeriodicalId":49863,"journal":{"name":"Mathematical Medicine and Biology-A Journal of the Ima","volume":"35 2","pages":"203-224"},"PeriodicalIF":1.1,"publicationDate":"2018-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1093/imammb/dqw025","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"34852673","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

On tear film breakup (TBU): dynamics and imaging. 泪膜破裂(TBU):动力学和成像。

IF 1.1 4区数学

Mathematical Medicine and Biology-A Journal of the Ima Pub Date : 2018-06-13 DOI: 10.1093/imammb/dqw023

Richard J Braun, Tobin A Driscoll, Carolyn G Begley, P Ewen King-Smith, Javed I Siddique

{"title":"On tear film breakup (TBU): dynamics and imaging.","authors":"Richard J Braun, Tobin A Driscoll, Carolyn G Begley, P Ewen King-Smith, Javed I Siddique","doi":"10.1093/imammb/dqw023","DOIUrl":"10.1093/imammb/dqw023","url":null,"abstract":"We report the results of some recent experiments to visualize tear film dynamics. We then study a mathematical model for tear film thinning and tear film breakup (TBU), a term from the ocular surface literature. The thinning is driven by an imposed tear film thinning rate which is input from in vivo measurements. Solutes representing osmolarity and fluorescein are included in the model. Osmolarity causes osmosis from the model ocular surface, and the fluorescein is used to compute the intensity corresponding closely to in vivo observations. The imposed thinning can be either one-dimensional or axisymmetric, leading to streaks or spots of TBU, respectively. For a spatially-uniform (flat) film, osmosis would cease thinning and balance mass lost due to evaporation; for these space-dependent evaporation profiles TBU does occur because osmolarity diffuses out of the TBU into the surrounding tear film, in agreement with previous results. The intensity pattern predicted based on the fluorescein concentration is compared with the computed thickness profiles; this comparison is important for interpreting in vivo observations. The non-dimensionalization introduced leads to insight about the relative importance of the competing processes; it leads to a classification of large vs small TBU regions in which different physical effects are dominant. Many regions of TBU may be considered small, revealing that the flow inside the film has an appreciable influence on fluorescence imaging of the tear film.","PeriodicalId":49863,"journal":{"name":"Mathematical Medicine and Biology-A Journal of the Ima","volume":"35 2","pages":"145-180"},"PeriodicalIF":1.1,"publicationDate":"2018-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1093/imammb/dqw023","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"34853280","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 21

A Two-phase mixture model of platelet aggregation. 血小板聚集的两相混合模型。

IF 1.1 4区数学

Mathematical Medicine and Biology-A Journal of the Ima Pub Date : 2018-06-13 DOI: 10.1093/imammb/dqx001

Jian Du, Aaron L Fogelson

{"title":"A Two-phase mixture model of platelet aggregation.","authors":"Jian Du, Aaron L Fogelson","doi":"10.1093/imammb/dqx001","DOIUrl":"https://doi.org/10.1093/imammb/dqx001","url":null,"abstract":"We present a two-phase model of platelet aggregation in coronary-artery-sized blood vessels. The model tracks the number densities of three platelet populations as well as the concentration of a platelet activating chemical. Through the formation of elastic bonds, activated platelets can cohere with one another to form a platelet thrombus. Bound platelets in a thrombus move in a velocity field different from that of the bulk fluid. Stresses produced by the elastic bonds act on the bound platelet material. Movement of the bound platelet material and that of the background fluid are coupled through an interphase drag and an incompressibility constraint. The relative motion between bound platelets and the background fluid permits intraclot transport of individual platelets and activating chemical, allows the bound platelet density to reach levels much higher than the platelet density in the bulk blood, and allows thrombus formation to occur on a physiological timescale, all of which were precluded by our earlier single phase model. Computational results from the two-phase model indicate that through complicated fluid-structure interactions, the platelet thrombus can develop significant spatial inhomogeneities and that the amount of intraclot flow may greatly affect the growth, density, and stability of a thrombus.","PeriodicalId":49863,"journal":{"name":"Mathematical Medicine and Biology-A Journal of the Ima","volume":"35 2","pages":"225-256"},"PeriodicalIF":1.1,"publicationDate":"2018-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1093/imammb/dqx001","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"34853060","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 14

Operations management in distribution networks within a smart city framework. 智慧城市框架下配电网的运营管理。

IF 1.1 4区数学

Mathematical Medicine and Biology-A Journal of the Ima Pub Date : 2018-04-01 Epub Date: 2017-02-20 DOI: 10.1093/imaman/dpw024

Raffaele Cerulli, Renata Paola Dameri, Anna Sciomachen

{"title":"Operations management in distribution networks within a smart city framework.","authors":"Raffaele Cerulli, Renata Paola Dameri, Anna Sciomachen","doi":"10.1093/imaman/dpw024","DOIUrl":"https://doi.org/10.1093/imaman/dpw024","url":null,"abstract":"This article studies a vehicle routing problem with environmental constraints that are motivated by the requirements for sustainable urban transport. The empirical research presents a fleet planning problem that takes into consideration both minimum cost vehicle routes and minimum pollution. The problem is formulated as a mixed integer linear programming model and experimentally validated using data collected from a real situation: a grocery company delivering goods ordered via e-channels to customers spread in the urban and metropolitan area of Genoa smart city. The proposed model is a variant of the vehicle routing problem tailored to include environmental issues and street limitations. Its novelty regards also the use of real data instances provided by the B2C grocery company. Managerial implications are the choice of both the routes and the number and type of vehicles. Results show that commercial distribution strategies achieve better results in term of both business and environmental performance, provided the smart mobility goals and constraints are included into the distribution model from the beginning.","PeriodicalId":49863,"journal":{"name":"Mathematical Medicine and Biology-A Journal of the Ima","volume":"29 2","pages":"189-205"},"PeriodicalIF":1.1,"publicationDate":"2018-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1093/imaman/dpw024","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"34853279","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 9

Extended models for nosocomial infection: parameter estimation and model selection. 医院感染的扩展模型:参数估计和模型选择。

IF 1.1 4区数学

Mathematical Medicine and Biology-A Journal of the Ima Pub Date : 2018-03-16 DOI: 10.1093/imammb/dqx010

Alun Thomas, Karim Khader, Andrew Redd, Molly Leecaster, Yue Zhang, Makoto Jones, Tom Greene, Matthew Samore

{"title":"Extended models for nosocomial infection: parameter estimation and model selection.","authors":"Alun Thomas, Karim Khader, Andrew Redd, Molly Leecaster, Yue Zhang, Makoto Jones, Tom Greene, Matthew Samore","doi":"10.1093/imammb/dqx010","DOIUrl":"https://doi.org/10.1093/imammb/dqx010","url":null,"abstract":"We consider extensions to previous models for patient level nosocomial infection in several ways, provide a specification of the likelihoods for these new models, specify new update steps required for stochastic integration, and provide programs that implement these methods to obtain parameter estimates and model choice statistics. Previous susceptible-infected models are extended to allow for a latent period between initial exposure to the pathogen and the patient becoming themselves infectious, and the possibility of decolonization. We allow for multiple facilities, such as acute care hospitals or long-term care facilities and nursing homes, and for multiple units or wards within a facility. Patient transfers between units and facilities are tracked and accounted for in the models so that direct importation of a colonized individual from one facility or unit to another might be inferred. We allow for constant transmission rates, rates that depend on the number of colonized individuals in a unit or facility, or rates that depend on the proportion of colonized individuals. Statistical analysis is done in a Bayesian framework using Markov chain Monte Carlo methods to obtain a sample of parameter values from their joint posterior distribution. Cross validation, deviance information criterion and widely applicable information criterion approaches to model choice fit very naturally into this framework and we have implemented all three. We illustrate our methods by considering model selection issues and parameter estimation for data on methicilin-resistant Staphylococcus aureus surveillance tests over 1 year at a Veterans Administration hospital comprising seven wards.","PeriodicalId":49863,"journal":{"name":"Mathematical Medicine and Biology-A Journal of the Ima","volume":"35 suppl_1","pages":"29-49"},"PeriodicalIF":1.1,"publicationDate":"2018-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1093/imammb/dqx010","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"35517355","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 10

Relating cell shape and mechanical stress in a spatially disordered epithelium using a vertex-based model. 使用基于顶点的模型在空间紊乱的上皮中与细胞形状和机械应力相关。

IF 1.1 4区数学

Mathematical Medicine and Biology-A Journal of the Ima Pub Date : 2018-03-16 DOI: 10.1093/imammb/dqx008

Alexander Nestor-Bergmann, Georgina Goddard, Sarah Woolner, Oliver E Jensen

{"title":"Relating cell shape and mechanical stress in a spatially disordered epithelium using a vertex-based model.","authors":"Alexander Nestor-Bergmann, Georgina Goddard, Sarah Woolner, Oliver E Jensen","doi":"10.1093/imammb/dqx008","DOIUrl":"https://doi.org/10.1093/imammb/dqx008","url":null,"abstract":"Using a popular vertex-based model to describe a spatially disordered planar epithelial monolayer, we examine the relationship between cell shape and mechanical stress at the cell and tissue level. Deriving expressions for stress tensors starting from an energetic formulation of the model, we show that the principal axes of stress for an individual cell align with the principal axes of shape, and we determine the bulk effective tissue pressure when the monolayer is isotropic at the tissue level. Using simulations for a monolayer that is not under peripheral stress, we fit parameters of the model to experimental data for Xenopus embryonic tissue. The model predicts that mechanical interactions can generate mesoscopic patterns within the monolayer that exhibit long-range correlations in cell shape. The model also suggests that the orientation of mechanical and geometric cues for processes such as cell division are likely to be strongly correlated in real epithelia. Some limitations of the model in capturing geometric features of Xenopus epithelial cells are highlighted.","PeriodicalId":49863,"journal":{"name":"Mathematical Medicine and Biology-A Journal of the Ima","volume":"35 suppl_1","pages":"1-27"},"PeriodicalIF":1.1,"publicationDate":"2018-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1093/imammb/dqx008","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"35584618","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 41

Computed flow and fluorescence over the ocular surface. 眼表面的计算流量和荧光。

IF 1.1 4区数学

Mathematical Medicine and Biology-A Journal of the Ima Pub Date : 2018-03-16 DOI: 10.1093/imammb/dqx011

Longfei Li, R J Braun, W D Henshaw, P E King-Smith

引用次数: 5

Mathematical model of calcium exchange during haemodialysis using a citrate containing dialysate. 使用含柠檬酸的透析液进行血液透析时钙交换的数学模型。

IF 1.1 4区数学

Mathematical Medicine and Biology-A Journal of the Ima Pub Date : 2018-03-16 DOI: 10.1093/imammb/dqx013

Julien Aniort, Laurent Chupin, Nicolae Cîndea

{"title":"Mathematical model of calcium exchange during haemodialysis using a citrate containing dialysate.","authors":"Julien Aniort, Laurent Chupin, Nicolae Cîndea","doi":"10.1093/imammb/dqx013","DOIUrl":"https://doi.org/10.1093/imammb/dqx013","url":null,"abstract":"Calcium has two important roles in haemodialysis. It participates in the activation of blood coagulation and calcium intakes have a major impact on patient mineral and bone metabolism. The aim of this article is to propose a mathematical model for calcium ions concentration in a dialyzer during haemodialysis using a citrate dialysate. The model is composed of two elements. The first describes the flows of blood and dialysate in a dialyzer fibre. It was obtained by asymptotic analysis and takes into account the anisotropy of the fibres forming a dialyzer. Newtonian and non-Newtonian blood rheologies were tested. The second part of the model predicts the evolution of the concentration of five chemical species present in these fluids. The fluid velocity field drives the convective part of a convection-reaction-diffusion system that models the exchange of free and complexed calcium. We performed several numerical experiments to calculate the free calcium concentration in the blood in a dialyzer using dialysates with or without citrate. The choice of blood rheology had little effect on the fluid velocity field. Our model predicts that only a citrate based dialysate without calcium can decrease free calcium concentration at the blood membrane interface low enough to inhibit blood coagulation. Moreover for a given calcium dialysate concentration, adding citrate to the dialysate decreases total calcium concentration in the blood at the dialyzer outlet. This decrease of the calcium concentration can be compensated by infusing in the dialyzed blood a quantity of calcium computed from the model.","PeriodicalId":49863,"journal":{"name":"Mathematical Medicine and Biology-A Journal of the Ima","volume":"35 suppl_1","pages":"87-120"},"PeriodicalIF":1.1,"publicationDate":"2018-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1093/imammb/dqx013","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"35539162","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 7