Fiber Transport and Deposition in Human Upper Tracheobronchial Airways

2010 ◽  
Author(s):  
L. Tian ◽  
G. Ahmadi ◽  
P. K. Hopke ◽  
Y.-S. Cheng
Keyword(s):  
Pathological Response ◽  
Lung Model ◽  
Deposition Pattern ◽  
Asbestos Fibers ◽  
The Past ◽  
Surrounding Environment ◽  
Multi Level ◽  
Airway Morphology ◽  
Living Being

Transport and deposition of inhaled asbestos fibers has been studied in the past few decades due to its pathological response in living being. Of the earlier study, in vitro and vivo experiments in human and animal subjects were conducted and measurements were made where carcinogenicity of these particles was investigated. In this work, the transport and deposition of elongated ellipsoidal fibers were numerically simulated in a physiological realistic multi-level lung model. Detailed motion of the inhaled fibers and their interaction with the surrounding environment were reproduced by solving the system of coupled nonlinear equations governing the fibers’ translational and rotational motion. This information has never been revealed in past studies. Correlations between the deposition pattern, fiber characteristics, breathing conditions, and airway morphology in human upper tracheobronchial airways were analyzed. The results were compared with experimental measurements, and carcinogenicity of these fibers was discussed.

Transport and Deposition of Elongated Particles in the Upper Airways

2011 ◽  
Author(s):  
L. Tian ◽  
G. Ahmadi
Keyword(s):  
Lung Model ◽  
Experimental Measurements ◽  
Deposition Pattern ◽  
Upper Airways ◽  
Coupled Equations ◽  
Surrounding Environment ◽  
Multi Level ◽  
Rotational Motions ◽  
Airway Morphology ◽  
Good Agreement

Transport and deposition of elongated particle and fibers have been of interest due to their pathological responses. In this work, the transport and deposition of elongated particles and ellipsoidal fibers were numerically simulated in a physiological realistic multi-level lung model. Detailed motion of the inhaled fibers and their interaction with the surrounding environment were reproduced by solving the system of coupled equations governing the elongated particles translational and rotational motions. Correlations between the deposition pattern, fiber characteristics, breathing rates, and airway morphology in human upper tracheobronchial airways were analyzed. The results were compared with experimental measurements, and good agreement was found.

Spatiotemporal Changes of Riverbed and Surrounding Environment in Yongding River (Beijing section) in the Past 40 Years

2020 ◽  
Vol 64 (4) ◽  
pp. 40407-1-40407-13 ◽  
Author(s):  
Ran Pang ◽  
He Huang ◽  
Tri Dev Acharya
Keyword(s):  
Economic Development ◽  
Water Conservation ◽  
Human Activities ◽  
Urban Areas ◽  
Water Volume ◽  
Cropland Area ◽  
The Past ◽  
Surrounding Environment ◽  
Spatiotemporal Changes ◽  
Yongding River

Abstract Yongding River is one of the five major river systems in Beijing. It is located to the west of Beijing. It has influenced culture along its basin. The river supports both rural and urban areas. Furthermore, it influences economic development, water conservation, and the natural environment. However, during the past few decades, due to the combined effect of increasing population and economic activities, a series of changes have led to problems such as the reduction in water volume and the exposure of the riverbed. In this study, remote sensing images were used to derive land cover maps and compare spatiotemporal changes during the past 40 years. As a result, the following data were found: forest changed least; cropland area increased to a large extent; bareland area was reduced by a maximum of 63%; surface water area in the study area was lower from 1989 to 1999 because of the excessive use of water in human activities, but it increased by 92% from 2010 to 2018 as awareness about protecting the environment arose; there was a small increase in the built-up area, but this was more planned. These results reveal that water conservancy construction, agroforestry activities, and increasing urbanization have a great impact on the surrounding environment of the Yongding River (Beijing section). This study discusses in detail how the current situation can be attributed to of human activities, policies, economic development, and ecological conservation Furthermore, it suggests improvement by strengthening the governance of the riverbed and the riverside. These results and discussion can be a reference and provide decision support for the management of southwest Beijing or similar river basins in peri-urban areas.

Bioengineered in vitro Vascular Models for Applications in Interventional Radiology

2019 ◽  
Vol 24 (45) ◽  
pp. 5367-5374 ◽  
Author(s):  
Xiaoyun Li ◽  
Seyed M. Moosavi-Basri ◽  
Rahul Sheth ◽  
Xiaoying Wang ◽  
Yu S. Zhang
Keyword(s):  
Interventional Radiology ◽  
Animal Models ◽  
Blood Vessels ◽  
In Vitro Models ◽  
The Past ◽  
Endovascular Interventions ◽  
Conventional Animal ◽  
Vascular Structures

The role of endovascular interventions has progressed rapidly over the past several decades. While animal models have long-served as the mainstay for the advancement of this field, the use of in vitro models has become increasingly widely adopted with recent advances in engineering technologies. Here, we review the strategies, mainly including bioprinting and microfabrication, which allow for fabrication of biomimetic vascular models that will potentially serve to supplement the conventional animal models for convenient investigations of endovascular interventions. Besides normal blood vessels, those in diseased states, such as thrombosis, may also be modeled by integrating cues that simulate the microenvironment of vascular disorders. These novel engineering strategies for the development of biomimetic in vitro vascular structures will possibly enable unconventional means of studying complex endovascular intervention problems that are otherwise hard to address using existing models.

Novel Findings of Anti-cancer Property of Propofol

2018 ◽  
Vol 18 (2) ◽  
pp. 156-165 ◽  
Author(s):  
Jiaqiang Wang ◽  
Chien-shan Cheng ◽  
Yan Lu ◽  
Xiaowei Ding ◽  
Minmin Zhu ◽  
...  
Keyword(s):  
General Anesthesia ◽  
Cancer Progression ◽  
Molecular Mechanisms ◽  
Intravenous Anesthetic ◽  
The Past ◽  
Anti Cancer ◽  
Underlying Mechanisms ◽  
Recent Attention

Background: Propofol, a widely used intravenous anesthetic agent, is traditionally applied for sedation and general anesthesia. Explanation: Recent attention has been drawn to explore the effect and mechanisms of propofol against cancer progression in vitro and in vivo. Specifically, the proliferation-inhibiting and apoptosis-inducing properties of propofol in cancer have been studied. However, the underlying mechanisms remain unclear. Conclusion: This review focused on the findings within the past ten years and aimed to provide a general overview of propofol's malignance-modulating properties and the potential molecular mechanisms.

Near Wall Turbulence Effects on Particle Transport and Deposition in Human Tracheobronchial Multi-Level Bifurcation Model

2015 ◽  
Author(s):  
Amir A. Mofakham ◽  
Lin Tian ◽  
Goodarz Ahmadi
Keyword(s):  
Boundary Conditions ◽  
Particle Deposition ◽  
Flow Simulation ◽  
Tracheobronchial Tree ◽  
Lung Model ◽  
Wall Turbulence ◽  
Nano Particles ◽  
Turbulent Regime ◽  
Computationally Efficient ◽  
Multi Level

Transport and deposition of micro and nano-particles in the upper tracheobronchial tree were analyzed using a multi-level asymmetric lung bifurcation model. The multi-level lung model is flexible and computationally efficient by fusing sequence of individual bifurcations with proper boundary conditions. Trachea and the first two generations of the tracheobronchial airway were included in the analysis. In these regions, the airflow is in turbulent regime due to the disturbances induced by the laryngeal jet. Anisotropic Reynolds stress transport turbulence model (RSTM) was used for mean the flow simulation, together with the enhanced two-layer model boundary conditions. Particular attention is given to evaluate the importance of the “quadratic variation of the turbulent fluctuations perpendicular to the wall” on particle deposition in the upper tracheobroncial airways.

scholarly journals Interfacing cells with organic transistors: a review of in vitro and in vivo applications

Lab on a Chip ◽  
2021 ◽  
Vol 21 (5) ◽  
pp. 795-820
Author(s):  
Andrea Spanu ◽  
Laura Martines ◽  
Annalisa Bonfiglio
Keyword(s):  
Organic Transistors ◽  
Future Perspectives ◽  
The Past ◽  
The Future

This review focuses on the applications of organic transistors in cellular interfacing. It offers a comprehensive retrospective of the past, an overview of the latest innovations, and a glance on the future perspectives of this fast-evolving field.

scholarly journals Network pharmacology-based analysis for unraveling potential cancer-related molecular targets of Egyptian propolis phytoconstituents accompanied with molecular docking and in vitro studies

RSC Advances ◽  
2021 ◽  
Vol 11 (19) ◽  
pp. 11610-11626
Author(s):  
Reham S. Ibrahim ◽  
Alaa A. El-Banna
Keyword(s):  
Molecular Docking ◽  
Cancer Treatment ◽  
Mechanism Of Action ◽  
Molecular Targets ◽  
Integrated Approach ◽  
In Vitro Studies ◽  
Network Pharmacology ◽  
Multi Level ◽  
Potential Cancer

Multi-level mechanism of action of propolis constituents in cancer treatment using an integrated approach of network pharmacology-based analysis, molecular docking and in vitro cytotoxicity testing.

scholarly journals Antidiscrimination Meets Integration Policies: Exploring New Diversity-Related Challenges in Europe

2021 ◽  
Vol 10 (6) ◽  
pp. 221
Author(s):  
Tina Magazzini
Keyword(s):  
Critical Race Studies ◽  
Racial Justice ◽  
Critical Race ◽  
Policy Makers ◽  
Race Studies ◽  
Managing Diversity ◽  
The Past ◽  
Migrant Integration ◽  
Multi Level ◽  
Racial Ethnic

Contemporary European societies are increasingly diverse. Migration both within and to Europe has contributed over the past decades to the rise of new religious, racial, ethnic, social, cultural and economic inequality. Such transformations have raised questions about the (multi-level) governance of diversity in Europe, thus determining new challenges for both scholars and policy-makers. Whilst the debate around diversity stemming from migration has become a major topic in urban studies, political science and sociology in Europe, Critical Race Studies and Intersectionality have become central in US approaches to understanding inequality and social injustice. Among the fields where ‘managing diversity’ has become particularly pressing, methodological issues on how to best approach minorities that suffer from multiple discrimination represent some of the hottest subjects of concern. Stemming from the interest in putting into dialogue the existing American scholarship on CRT and anti-discrimination with the European focus on migrant integration, this paper explores the issue of integration in relation to intersectionality by merging the two frames. In doing so, it provides some observations about the complementarity of a racial justice approach for facing the new diversity-related challenges in European polity. In particular, it illustrates how Critical Race Studies can contribute to the analysis of inequality in Europe while drawing on the integration literature.

Potential of enzymes or a centrifuged rumen fluid to estimate proteolysis of foods

1998 ◽  
Vol 22 ◽  
pp. 120-122
Author(s):  
A. S. Chaudhry
Keyword(s):  
Rumen Fluid ◽  
Food Proteins ◽  
The Past ◽  
Ruminal Digestion ◽  
Selection Of ◽  
In Sacco

The need to develop an in vitro method to simulate ruminal digestion of protein foods has long been recognized. An in vitro method must be more rapid, consistent and convenient than in sacco methods. Purified enzymes have been examined in the past to estimate in vitro degradability of protein foods (Poos-Floyd et al., 1985; Aufrere et al., 1991; Luchini et al., 1996) or their fractions (Chaudhry and Webster, 1994). However, the selection of an appropriate enzyme for a range of foodstuffs remains to be realized. This study examined the potential of two enzymes and a centrifuged rumen fluid (CRF) to estimate proteolysis of food proteins.

scholarly journals In Vivo Pharmacodynamics of Ceftobiprole against Multiple Bacterial Pathogens in Murine Thigh and Lung Infection Models

2008 ◽  
Vol 52 (10) ◽  
pp. 3492-3496 ◽  
Author(s):  
W. A. Craig ◽  
D. R. Andes
Keyword(s):  
Serum Levels ◽  
Lung Infection ◽  
Lung Model ◽  
Dose Fractionation ◽  
Time Curve ◽  
Gram Negative ◽  
Infection Models ◽  
Bactericidal Activities

ABSTRACT Ceftobiprole medocaril is the parenteral prodrug of ceftobiprole, a novel pyrrolidinone broad-spectrum cephalosporin with in vitro and in vivo bactericidal activities against methicillin-resistant Staphylococcus aureus (MRSA) and penicillin-resistant Streptococcus pneumoniae (PRSP). We have used murine thigh and lung infection models in neutropenic and normal mice to characterize the in vivo pharmacokinetic (PK)-pharmacodynamic (PD) activities of ceftobiprole against multiple strains of S. aureus (including MRSA), S. pneumoniae (including PRSP), and gram-negative bacilli. Serum levels of ceftobiprole following the administration of multiple doses were determined by a microbiological assay. In vivo bactericidal activities and postantibiotic effects (PAEs) of ceftobiprole against MRSA and PRSP strains were determined from serial CFU/thigh values following single doses of ceftobiprole (40 and 160 mg/kg of body weight). Dose fractionation studies were used to determine which PK-PD index correlated best with activity. Magnitudes of the PK-PD indices were calculated from MICs and PK parameters. A sigmoid dose-response model was used to estimate the dose (mg/kg/24 h) required to achieve a static and 2-log10 kill effects over 24 h. PK results showed area under the concentration-time curve/dose values of 1.8 to 2.8 and half-lives of 0.29 to 0.51 h. MICs ranged from 0.015 to 2 μg/ml. Ceftobiprole demonstrated time-dependent killing; its in vivo PAEs varied from 3.8 h to 4.8 h for MRSA and from 0 to 0.8 h for PRSP. The time above MIC (T > MIC) correlated best with efficacy for both MRSA and PRSP. The T > MIC values required for the static doses were significantly longer (P < 0.001) for Enterobacteriaceae (36 to 45%) than for S. aureus (14 to 28%) and S. pneumoniae (15 to 22%). The drug showed activities in the lung model similar to those in the thigh model. The presence of neutrophils significantly enhanced the activity of ceftobiprole against S. pneumoniae but only slightly against Klebsiella pneumoniae. Based on its PD profile, ceftobiprole is a promising new β-lactam agent with activity against gram-negative and gram-positive organisms including MRSA and PRSP.

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