scholarly journals Physics-based multiscale mass transport model in drug delivery and tumor microenvironment

2015 ◽  
Author(s):  
Arturas Ziemys ◽  
Milos Kojic ◽  
Mauro Ferrari

We describe multiscale transport model, which was developed to simulate drug diffusion and convection in tissues and drug vectors. Models rely on material properties and physical laws of transport. Our methods show that drug transport analysis may provide deep insight into mechanisms of pharmacokinetics useful in nanotherapeutics and transport study within tumor microenvironment. Because the method relies on material properties and structures, the approach can help studying phenotypical differences as well.

2019 ◽  
Author(s):  
Wei Li ◽  
Hao-Fei Wang ◽  
Zhi-Yong Li ◽  
Tong Wang ◽  
Chun-Xia Zhao

AbstractThe delivery of adequate concentration of anticancer drugs to tumor site is critical to achieve effective therapeutic treatment, but it is challenging to experimentally observe drug transport and investigate the spatial distribution of the drug in tumor microenvironment. In this study, we investigated the drug transport from a blood vessel to tumor tissue, and explored the effect of tumor size, tumor numbers and positioning on drug concentration distribution using a numerical method in combination with a microfluidic Tumor-Vasculature-on-a-Chip (TVOC) model. The TVOC model is composed of a vessel channel, a tumor channel sandwiched with a porous membrane. A species transport model based on computational fluid dynamics was adapted to investigate drug transport. The numerical simulation was firstly validated using experimental data, and then used to analyse the spatial-temporal structure of the flow, and to investigate the effect of tumor size and positioning on drug transport and drug concentration heterogeneity. We found the drug concentration surrounding the tumor is highly heterogeneous, with the most downstream point the most difficult for drugs to transport and the nearest point to the blood vessel the easiest. Moreover, tumor size and positioning contribute significantly to this drug concentration heterogeneity on tumor surface, which is dramatically augmented in large and downstream-positioned tumors. These studies established the relationship between solid tumor size/positioning and drug concentration heterogeneity in the tumor microenvironment, which could help to understand heterogenous drug distribution in tumor microenvironment.


Nature ◽  
2020 ◽  
Vol 581 (7809) ◽  
pp. 385-386
Author(s):  
Deanna M. Church
Keyword(s):  

2018 ◽  
Author(s):  
Tsair-Wei Chien ◽  
Hsien-Yi Wang ◽  
Yang Shao ◽  
Willy Chou

BACKGROUND Researchers often spend a great deal of time and effort retrieving related journals for their studies and submissions. Authors often designate one article and then retrieve other articles that are related to the given one using PubMed’s service for finding cited-by or similar articles. However, to date, none present the association between cited-by and similar journals related to a given journal. Authors need one effective and efficient way to find related journals on the topic of mobile health research. OBJECTIVE This study aims (1) to show the related journals for a given journal by both cited-by and similarity criteria; (2) to present the association between cited-by and similarity journals related to a given journal; (3) to inspect the patterns of network density indices among clusters classified by social network analysis (SNA); (4) to investigate the feature of Kendall's coefficient(W) of concordance. METHODS We obtained 676 abstracts since 2013 from Medline based on the keywords of ("JMIR mHealth and uHealth"[Journal]) on June 30, 2018, and plotted the clusters of related journals on Google Maps by using MS Excel modules. The features of network density indices were examined. The Kendall coefficient (W) was used to assess the concordance of clusters across indices. RESULTS This study found that (1) the journals related to JMIR mHealth and uHealth are easily presented on dashboards; (2) a mild association(=0.14) exists between cited-by and similar journals related to JMIR mHealth and uHealth; (3) the median Impact Factor were 3.37 and 2.183 based on the representatives of top ten clusters grouped by the cited-by and similar journals, respectively; (4) all Kendall’s coefficients(i.e., 0.82, 0.89, 0.92, and 0.75) for the four sets of density centrality have a statistically significant concordance (p < 0.05). CONCLUSIONS SNA provides deep insight into the relationships of related journals to a given journal. The results of this research can provide readers with a knowledge and concept diagram to use with future submissions to a given journal in the subject category of Mobile Health Research. CLINICALTRIAL Not available


Author(s):  
Hongnan Wu ◽  
Yajing Sun ◽  
Lingjie Sun ◽  
Liwei Wang ◽  
Xiaotao Zhang ◽  
...  

Author(s):  
Xiaojuan Tian ◽  
Yueting Zhou ◽  
Lihua Wang ◽  
Shenghu Ding

AbstractThe contact problem for thermoelectric materials with functionally graded properties is considered. The material properties, such as the electric conductivity, the thermal conductivity, the shear modulus, and the thermal expansion coefficient, vary in an exponential function. Using the Fourier transform technique, the electro-thermo-elastic problems are transformed into three sets of singular integral equations which are solved numerically in terms of the unknown normal electric current density, the normal energy flux, and the contact pressure. Meanwhile, the complex homogeneous solutions of the displacement fields caused by the gradient parameters are simplified with the help of Euler’s formula. After addressing the non-linearity excited by thermoelectric effects, the particular solutions of the displacement fields can be assessed. The effects of various combinations of material gradient parameters and thermoelectric loads on the contact behaviors of thermoelectric materials are presented. The results give a deep insight into the contact damage mechanism of functionally graded thermoelectric materials (FGTEMs).


2020 ◽  
Vol 44 (44) ◽  
pp. 19103-19112
Author(s):  
Monika ◽  
Azaj Ansari

This work is based on a deep insight into a comparative study of C–H vs. O–H bond activation of allylic compound by the high valent iron complex. Our theoretical findings can help to design catalysts with better efficiency for catalytic reactions.


2019 ◽  
Vol 8 (4) ◽  
pp. 17-41
Author(s):  
Maria Panagiotopoulou ◽  
Margarita Kokla ◽  
Anastasia Stratigea

Despite the remarkable interest in smart cities, noticed during the last decade, a consistent comprehension of the concept is not yet fully realized. Various definitions, ranging from exclusively technology-oriented perceptions to broader views, have been introduced, establishing a definitional polyphony and causing lack of semantic interoperability. Empirical evidence witnesses the prevalence of technology-pushed smart city initiatives as well as their failure to meet expectations in several urban domains. When planning “smart,” the relevance of ICT and their applications should be in alignment with spatial and other urban peculiarities and sub-systems' interactions, implying the need for getting deep insight into the city's ontology. The paper focuses on the extension/enrichment of an existing smart city ontology, with concepts and relationships stemming from Mediterranean small and medium-sized cities, in an attempt to outline their main key drivers and their interrelationships and fully grasp the smart city concept in the particular spatial context.


2013 ◽  
Vol 14 (1) ◽  
pp. 81-90 ◽  
Author(s):  
W. R. Furnass ◽  
R. P. Collins ◽  
P. S. Husband ◽  
R. L. Sharpe ◽  
S. R. Mounce ◽  
...  

The erosion of the cohesive layers of particulate matter that causes discolouration in water distribution system mains has previously been modelled using the Prediction of Discolouration in Distribution Systems (PODDS) model. When first proposed, PODDS featured an unvalidated means by which material regeneration on pipe walls could be simulated. Field and laboratory studies of material regeneration have yielded data that suggest that the PODDS formulations incorrectly model these processes. A new model is proposed to overcome this shortcoming. It tracks the relative amount of discolouration material that is bound to the pipe wall over time at each of a number of shear strengths. The model formulations and a mass transport model have been encoded as software, which has been used to verify the model's constructs and undertake sensitivity analyses. The new formulations for regeneration are conceptually consistent with field and laboratory observed data and have potential value in the proactive management of water distribution systems, such as evaluating change in discolouration risk and planning timely interventions.


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