scholarly journals Evaluation of the Deposition of Nanoparticles on the Human Respiratory Tract from the Burning of Diesel/ Biodiesel/ Additive

2021 ◽  
Vol 4 (1) ◽  
pp. 2-8
Author(s):  
Clara Rodrigues Pereira ◽  
Pedro Bancillon Ventin Muniz ◽  
Katheelin Rios Santa Rosa ◽  
Lílian Lefol Nani Guarieiro ◽  
Ednildo Andrade Torres
Keyword(s):  
Binary Mixture ◽  
Respiratory Tract ◽  
Human Health ◽  
Ternary Mixture ◽  
Lung Model ◽  
Pollutant Emissions ◽  
Human Respiratory Tract ◽  
Accumulation Mode ◽  
The Impact

This study aimed to evaluate the deposition in the respiratory tract of nanoparticles (11.5nm to 365.2nm) from the burning of diesel, biodiesel, and additives. The studied fuels were pure diesel (D), a binary mixture of pure diesel with 11% biodiesel (B11), and a ternary mixture of pure diesel, with 11% biodiesel and with the biocatalyst Xmile (B11X). The impact of nanoparticles on health was assessed using the MPPD lung model. From the tests, the burning of the studied fuels showed a concentration of some particles in the accumulation mode (50nm to 120 nm). When comparing fuels, it was clear that B11 emits more particles and has a greater deposition capacity in the lung. B11X is efficient in reducing pollutant emissions as well as impacting human health.  

A theory of aerosol deposition in the human respiratory tract

1975 ◽  
Vol 38 (1) ◽  
pp. 77-85 ◽  
Author(s):  
D. B. Taulbee ◽  
C. P. Yu
Keyword(s):  
Particle Size ◽  
Respiratory Tract ◽  
Particle Deposition ◽  
Particle Concentration ◽  
Diffusion Mechanism ◽  
Aerosol Deposition ◽  
Lung Model ◽  
Brownian Diffusion ◽  
Human Respiratory Tract ◽  
Apparent Diffusion

The deposition of inhaled aerosol particles in the human respiratory tract is due to the mechanisms of inertia impaction, Brownian diffusion, and gravitational settling. A theory is developed to predict the particle deposition and its distribution in human respiratory tract for any breathing condition. A convection-diffusion equation for the particle concentration with a loss term is used to describe the transport and deposition of particles. In this equation, an apparent diffusion coefficient due to the velocity dispersion in the lung is present and found to be the dominant diffusion mechanism for the cases considered here. Expressions for deposition by various mechanisms are also derived. The governing equation is solved numerically with Weibel's lung model A. The particle concentration at the mouth is calculated during washin and washout and compared favorably with experimental recordings for 0.5-mum diameter di(2-ethylhexyl) sebacate particles. The total deposition in the lung for particle size ranging from 0.05 to 5 mum is also computed for a 500-cm-3 tidal volume and 15 breaths/min. The results in general agree with recent measurements of Heyder et al. However, a particle size of minimum deposition is found to exist theoretically near 0.3 mum.

scholarly journals The degree of inhomogeneity of the absorbed cell nucleus doses in the bronchial region of the human respiratory tract

2019 ◽  
Vol 59 (1) ◽  
pp. 173-183 ◽  
Author(s):  
Péter Füri ◽  
Árpád Farkas ◽  
Balázs G. Madas ◽  
Werner Hofmann ◽  
Renate Winkler-Heil ◽  
...  
Keyword(s):  
Respiratory Tract ◽  
Lung Model ◽  
Radiological Protection ◽  
Radon Progeny ◽  
Cell Nuclei ◽  
Human Respiratory Tract ◽  
Radiation Burden ◽  
Precise Calculation ◽  
Absorbed Doses ◽  
Regional Lung

Abstract Inhalation of short-lived radon progeny is an important cause of lung cancer. To characterize the absorbed doses in the bronchial region of the airways due to inhaled radon progeny, mostly regional lung deposition models, like the Human Respiratory Tract Model (HRTM) of the International Commission on Radiological Protection, are used. However, in this model the site specificity of radiation burden in the airways due to deposition and fast airway clearance of radon progeny is not described. Therefore, in the present study, the Radact version of the stochastic lung model was used to quantify the cellular radiation dose distribution at airway generation level and to simulate the kinetics of the deposited radon progeny resulting from the moving mucus layer. All simulations were performed assuming an isotope ratio typical for an average dwelling, and breathing mode characteristic of a healthy adult sitting man. The study demonstrates that the cell nuclei receiving high doses are non-uniformly distributed within the bronchial airway generations. The results revealed that the maximum of the radiation burden is at the first few bronchial airway generations of the respiratory tract, where most of the lung carcinomas of former uranium miners were found. Based on the results of the present simulations, it can be stated that regional lung models may not be fully adequate to describe the radiation burden due to radon progeny. A more realistic and precise calculation of the absorbed doses from the decay of radon progeny to the lung requires deposition and clearance to be simulated by realistic models of airway generations.

scholarly journals Type VI secretion system killing by commensal Neisseria is influenced by expression of type four pili

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Rafael Custodio ◽  
Rhian M Ford ◽  
Cara J Ellison ◽  
Guangyu Liu ◽  
Gerda Mickute ◽  
...  
Keyword(s):  
Respiratory Tract ◽  
Spatial Dynamics ◽  
Secretion System ◽  
Type Vi Secretion System ◽  
Secretion Systems ◽  
Spatial Constraints ◽  
Human Respiratory Tract ◽  
Type Vi Secretion ◽  
The Impact ◽  
Commensal Neisseria

Type VI Secretion Systems (T6SSs) are widespread in bacteria and can dictate the development and organisation of polymicrobial ecosystems by mediating contact dependent killing. In Neisseria species, including Neisseria cinerea a commensal of the human respiratory tract, interbacterial contacts are mediated by Type four pili (Tfp) which promote formation of aggregates and govern the spatial dynamics of growing Neisseria microcolonies. Here, we show that N. cinerea expresses a plasmid-encoded T6SS that is active and can limit growth of related pathogens. We explored the impact of Tfp on N. cinerea T6SS-dependent killing within a colony and show that pilus expression by a prey strain enhances susceptibility to T6SS compared to a non-piliated prey, by preventing segregation from a T6SS-wielding attacker. Our findings have important implications for understanding how spatial constraints during contact-dependent antagonism can shape the evolution of microbial communities.

Numerical Simulation of Tidal Breathing Through the Human Respiratory Tract

2020 ◽  
Vol 142 (6) ◽  
Author(s):  
Jamasp Azarnoosh ◽  
Kidambi Sreenivas ◽  
Abdollah Arabshahi
Keyword(s):  
Respiratory Tract ◽  
Dynamics Simulation ◽  
Regional Ventilation ◽  
Human Respiratory Tract ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Fair Comparison ◽  
Flow Features ◽  
High Turbulence ◽  
The Impact

Abstract The objective of this study is to explore the complexity of airflow through the human respiratory tract by carrying out computational fluid dynamics simulation. In order to capture the detailed physics of the flow in this complex system, large eddy simulation (LES) is performed. The crucial step in this analysis is to investigate the impact of breathing transience on the flow field. In this connection, simulations are carried out for transient breathing in addition to peak inspiration and expiration. To enable a fair comparison, the flowrates for constant inspiration/expiration are selected to be identical to the peak flowrates during the transient breathing. Physiologically appropriate regional ventilation for two different flowrates is induced. The velocity field and turbulent flow features are discussed for both flowrates. The airflow through the larynx is observed to be significantly complex with high turbulence level, recirculation, and secondary flow while the level of turbulence decreases through the higher bifurcations.

Nanoparticle Mass Transfer From Lung Airways to Systemic Regions—Part I: Whole-Lung Aerosol Dynamics

2013 ◽  
Vol 135 (12) ◽  
Author(s):  
Arun V. Kolanjiyil ◽  
Clement Kleinstreuer
Keyword(s):  
Mass Transfer ◽  
Respiratory Tract ◽  
Current Model ◽  
Lung Model ◽  
Model Parameters ◽  
Therapeutic Effects ◽  
Human Respiratory Tract ◽  
Nanoparticle Transport ◽  
Multicompartmental Model ◽  
In Series

This is a two-part paper describing inhaled nanoparticle (NP) transport and deposition in a model of a human respiratory tract (Part I) as well as NP-mass transfer across barriers into systemic regions (Part II). Specifically, combining high-resolution computer simulation results of inhaled NP deposition in the human airways (Part I) with a multicompartmental model for NP-mass transfer (Part II) allows for the prediction of temporal NP accumulation in the blood and lymphatic systems as well as in organs. An understanding of nanoparticle transport and deposition in human respiratory airways is of great importance, as exposure to nanomaterial has been found to cause serious lung diseases, while the use of nanodrugs may have superior therapeutic effects. In Part I, the fluid-particle dynamics of a dilute NP suspension was simulated for the entire respiratory tract, assuming steady inhalation and planar airways. Thus, a realistic airway configuration was considered from nose/mouth to generation 3, and then an idealized triple-bifurcation unit was repeated in series and parallel to cover the remaining generations. Using the current model, the deposition of NPs in distinct regions of the lung, namely extrathoracic, bronchial, bronchiolar, and alveolar, was calculated. The region-specific NP-deposition results for the human lung model were used in Part II to determine the multicompartmental model parameters from experimental retention and clearance data in human lungs. The quantitative, experimentally validated results are useful in diverse fields, such as toxicology for exposure-risk analysis of ubiquitous nanomaterial as well as in pharmacology for nanodrug development and targeting.

Review on physicochemical properties of pollutants released from fireworks: environmental and health effects and prevention

2018 ◽  
Vol 26 (2) ◽  
pp. 133-155 ◽  
Author(s):  
Xinyuan Cao ◽  
Xuelei Zhang ◽  
Daniel Q. Tong ◽  
Weiwei Chen ◽  
Shichun Zhang ◽  
...  
Keyword(s):  
Human Health ◽  
Health Effects ◽  
Carbonaceous Material ◽  
Water Soluble ◽  
Pollutant Emissions ◽  
Gaseous Pollutants ◽  
Soluble Ions ◽  
Water Soluble Ions ◽  
The Government ◽  
The Impact

The pollutants released from fireworks may seriously deteriorate air quality and adversely impact human health. To aid in obtaining comprehensive observations and in establishing effective legislation aimed at controlling the short-term effects of fireworks, we systematically reviewed the findings of previous studies of the impact of fireworks. These studies, primarily located in Asia (>70% studies), Europe, and North America considered particle concentrations, size distribution, morphology, noise, and chemical composition (including water-soluble ions, elements, carbonaceous material, organic matter, and trace gases), along with the associated human health effects during a fireworks display. Forty-one percent of the studies suggested that the concentrations of firework particles were reported to be 1–5 times higher than the respective background values, and the mean ratios PM10/TSP, PM2.5/PM10, and PM1.0/PM2.5 were 0.64, 0.72, and 0.65, respectively. During festivals, the concentrations of SO42− and K+ were the highest of the water-soluble ions with the highest concentrations of K and S for major elements and CO and SO2 for gaseous pollutants. The health effects of particles and gaseous pollutants, including metals, emitted from fireworks need further epidemiological study to aid in the prevention of health problems and for the treatment of patients. Fireworks industries should use technical innovation to reduce pollutant emissions. Emissions inventories of fireworks displays should be compiled and used in Eulerian models to forecast the spatiotemporal distribution of pollutants and to further assistant the government in establishing appropriate restriction levels and legislations that balance environmental protection with the festive spirit.

Role of Nutraceuticals in Health Promotion and Disease Prevention: A Review in the Indian Context

2020 ◽  
Vol 19 (2) ◽  
pp. 139-145
Author(s):  
Sheena Chhabra ◽  
Apurva Bakshi ◽  
Ravineet Kaur
Keyword(s):  
Health Promotion ◽  
Disease Prevention ◽  
Human Health ◽  
Health Issues ◽  
Scholarly Literature ◽  
Indian Context ◽  
The Impact ◽  
Immense Potential ◽  
Specific Health

Nutraceuticals have been around for quite some time. As the nomenclature suggests, they are placed somewhere between food (nutra-) and medicine (-ceuticals) in terms of their impact on human health. Researches have focused on the impact of various types of nutraceuticals on health, their efficacy in health promotion and disease prevention, and often on suitable uses of certain categories of nutraceuticals for specific health issues. However, we are still far from utilizing the immense potential of nutraceuticals for benefiting human health in a substantial manner. We review the available scholarly literature regarding the role of nutraceuticals in health promotion, their efficacy in disease prevention and the perception of nutraceuticals' health benefits by consumers. Thereafter we analyze the need for regulation of nutraceuticals and various provisions regarding the same.

Evaluation of Nanotechniques and Conventional Techniques for the Removal of Dioxins

2018 ◽  
Vol 9 (1) ◽  
pp. 79-84
Author(s):  
Vaishali V. Shahare ◽  
Rajni Grover ◽  
Suman Meena
Keyword(s):  
Soil Sample ◽  
Human Health ◽  
Surface Area ◽  
Contaminated Soil ◽  
Conventional Treatment ◽  
Volume Ratio ◽  
Soil Samples ◽  
Dioxins And Furans ◽  
Palladized Iron ◽  
The Impact

Background: The persistent dioxins/furans has caused a worldwide concern as they influence the human health. Recent research indicates that nonmaterial may prove effective in the degradation of Dioxins/furans. The nanomaterials are very reactive owing to their large surface area to volume ratio and large number of reactive sites. However, nanotechnology applications face both the challenges and the opportunities to influence the area of environmental protection. Objective: i) To study the impact of oil mediated UV-irradiations on the removal of 2,3,7,8-TCDD, 2,3,7,8-TCDF, OCDD and OCDF in simulated soil samples. ii) To compare the conventional treatment methods with the modern available nanotechniques for the removal of selected Dioxins/furans from soil samples. Methods: The present work has investigated an opportunity of the degradation of tetra and octachlorinated dioxins and furans by using oil mediated UV radiations with subsequent extraction of respective dioxins/furans from soils. The results have been compared with the available nanotechniques. Results: The dioxin congeners in the simulated soil sample showed decrease in concentration with the increase in the exposure time and intensity of UV radiations. The dechlorination of PCDD/Fs using palladized iron has been found to be effective. Conclusion: Both the conventional methods and nanotechnology have a dramatic impact on the removal of Dioxins/furans in contaminated soil. However, the nanotechniques are comparatively costlier and despite the relatively high rates of PCDDs dechlorination by Pd/nFe, small fraction of the dioxins are recalcitrant to degradation over considerable exposure times.

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