scholarly journals CalTOX (registered trademark), A multimedia total exposure model spreadsheet user's guide. Version 4.0(Beta)

2002 ◽  
Author(s):  
T.E. McKone ◽  
K.G. Enoch
Keyword(s):  
Exposure Model ◽  
Total Exposure ◽  
Registered Trademark

scholarly journals Refinement of a model for evaluating the population exposure in an urban area

2014 ◽  
Vol 7 (2) ◽  
pp. 2335-2375
Author(s):  
J. Soares ◽  
A. Kousa ◽  
J. Kukkonen ◽  
L. Matilainen ◽  
L. Kangas ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Air Pollution ◽  
Urban Area ◽  
Ambient Air ◽  
Ambient Air Pollution ◽  
Exposure Model ◽  
Spatial And Temporal Variation ◽  
Population Exposure ◽  
Total Exposure ◽  
Modelling System

Abstract. A mathematical model is presented for the determination of human exposure to ambient air pollution in an urban area; the model is a refined version of a previously developed mathematical model EXPAND (EXposure model for Particulate matter And Nitrogen oxiDes). The model combines predicted concentrations, information on people's activities and location of the population to evaluate the spatial and temporal variation of average exposure of the urban population to ambient air pollution in different microenvironments. The revisions of the modelling system containing the EXPAND model include improvements of the associated urban emission and dispersion modelling system, an improved treatment of the time-use of population, and better treatment for the infiltration coefficients from outdoor to indoor air. The revised model version can also be used for evaluating intake fractions for various pollutants, source categories and population subgroups. We present numerical results on annual spatial concentration, time activity and population exposures to PM2.5 in the Helsinki Metropolitan Area and Helsinki for 2008 and 2009, respectively. Approximately 60% of the total exposure occurred at home, 17% at work, 4% in traffic and 19% in other micro-environments. The population exposure originated from the long range transported background concentrations was responsible for a major fraction, 86%, of the total exposure. The largest local contributors were vehicular emissions (12%) and shipping (2%).

Omaha childhood blood lead and environmental lead: A linear total exposure model

1984 ◽  
Vol 35 (1) ◽  
pp. 160-170 ◽  
Author(s):  
Carol R. Angle ◽  
Allan Marcus ◽  
I-Hui Cheng ◽  
Matilda S. McIntire
Keyword(s):  
Blood Lead ◽  
Exposure Model ◽  
Total Exposure ◽  
Environmental Lead

scholarly journals MicroRNA-1297 suppressed the Akt/GSK3β signaling pathway and stimulated neural apoptosis in an in vivo sevoflurane exposure model

2021 ◽  
Vol 49 (4) ◽  
pp. 030006052098210
Author(s):  
Quan Wang ◽  
Jingcong Luo ◽  
Ruiqiang Sun ◽  
Jia Liu
Keyword(s):  
Protein Expression ◽  
Signaling Pathway ◽  
Neuronal Apoptosis ◽  
In Vitro Model ◽  
Nervous System Development ◽  
Exposure Model ◽  
Control Group ◽  
Pten Protein ◽  
Vitro Model

Objective Common inhalation anesthetics used for clinical anesthesia (such as sevoflurane) may induce nerve cell apoptosis during central nervous system development. Furthermore, anesthetics can produce cognitive impairments, such as learning and memory impairments, that continue into adulthood. However, the precise mechanism remains largely undefined. We aimed to determine the function of microRNA-1297 (miR-1297) in sevoflurane-induced neurotoxicity. Methods Reverse transcription-polymerase chain reaction assays were used to analyze miR-1297 expression in sevoflurane-exposed mice. MTT and lactate dehydrogenase (LDH) assays were used to measure cell growth, and neuronal apoptosis was analyzed using flow cytometry. Western blot analyses were used to measure PTEN, PI3K, Akt, and GSK3β protein expression. Results In sevoflurane-exposed mice, miR-1297 expression was up-regulated compared with the control group. MiR-1297 up-regulation led to neuronal apoptosis, inhibition of cell proliferation, and increased LDH activity in the in vitro model of sevoflurane exposure. MiR-1297 up-regulation also suppressed the Akt/GSK3β signaling pathway and induced PTEN protein expression in the in vitro model. PTEN inhibition (VO-Ohpic trihydrate) reduced PTEN protein expression and decreased the effects of miR-1297 down-regulation on neuronal apoptosis in the in vitro model. Conclusion Collectively, the results indicated that miR-1297 stimulates sevoflurane-induced neurotoxicity via the Akt/GSK3β signaling pathway by regulating PTEN expression.

scholarly journals An experimental intraradicular biofilm model in the pig for evaluating irrigation techniques

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Toshinori Tanaka ◽  
Yoshio Yahata ◽  
Keisuke Handa ◽  
Suresh V. Venkataiah ◽  
Mary M. Njuguna ◽  
...  
Keyword(s):  
16S Rrna ◽  
Root Canal ◽  
Apical Periodontitis ◽  
Exposure Model ◽  
Rrna Gene ◽  
16S Rrna Sequence ◽  
Bacterial Phyla ◽  
Biofilm Model ◽  
Biofilm Removal

Abstract Background We established an in vivo intraradicular biofilm model of apical periodontitis in pigs in which we compared the efficacy of different irrigant activation techniques for biofilm removal. Methods Twenty roots from the deciduous mandibular second premolar of 5 male pigs were used. After pulpectomy, canals were left open for 2 weeks and then sealed for 4 weeks to enable the development of an intracanal biofilm. The intraradicular biofilms was evaluated using SEM and bacterial 16S rRNA gene-sequencing. To investigate the efficacy of biofilm removal, root canal irrigations were performed using conventional needle, passive ultrasonic, subsonic, or laser-activated irrigation. Real-time PCR was conducted to quantitate the remaining biofilm components. Statistical analysis was performed using ANOVA followed by a Tukey kramer post-hoc test with α = 0.05. Results The pulp exposure model was effective in inducing apical periodontitis and SEM analysis revealed a multi-layer biofilm formation inside the root canal. 16S rRNA sequence analysis identified Firmicutes, Bacteroidetes, and Fusobacteria as the predominant bacterial phyla components, which is similar to the microbiome profile seen in humans. None of the tested irrigation techniques completely eradicated the biofilm components from the root canal, but the subsonic and laser-activated irrigation methods produced the lowest bacterial counts (p < 0.05). Conclusions An experimental intraradicular biofilm model has been successfully established in pigs. Within the limitations of the study, subsonic or laser-activated irrigation demonstrated the best biofilm removal results in the pig system.

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