development of a novel simulation reactor for chronic exposure to atmospheric particulate matter - portable ozone generator

Epidemiology studies have shown that air pollution is associated with the incidence and mortality of heart and lung diseases.
At present, limited experimental models can be used to evaluate the physiological and cellular pathways of chronic multi-cell activation
Exposure of pollutants.
This manuscript describes an atmospheric simulation reactor (ASR)
This was developed to study the health effects of air pollutants, allowing mice to be controlled for long-term exposure to particulate and gas contaminants.
Exposure to secondary organic aerosol for 3 consecutive days (
A common air pollutant of particulate matter
At 10-50 μg/m3, SOA (30u2009μg/m3)+u2009ozone (65u2009ppb)
Or ozone (65u2009ppb)
Sulfur dioxide (NO2; 100u2009ppb).
Daily exposure to SOA alone leads to increased airway hyperresponsiveness (AHR)
As the concentration of SOA increases, it becomes Azolin. Multi-
Pollutants exposed by ozone and/or NO2 with sub
The toxic concentration of SOA can lead to the additive effect of AHR on Azolin.
Recruitment of airway inflammatory cells was not observed under any exposure conditions.
ASR developed in this study allows us to evaluate the number of related
Exposure of "real" contaminants
Repetition of living standards under controlled conditions and permits-
Exposure Studies.
All animal programmes are approved by the University of Toronto's advisory board on teacher animal services and are carried out in accordance with the guidelines of the Canadian Animal Care Board (CCAC).
Pure benzene solid (99%, Sigma-Aldrich, St.
Louis, Missouri, USA)
Heat to 55-65 °c in the glass tube, and steam is gently introduced into the quartz flow tube reactor in 0.
Purified air flow 5 l/min.
Purifying air through 1 l/min to produce ozone through an ozone generator (No.
97006601, UVP, Cambridge, United Kingdom)
And exposed (λu2009=u2009180u2009nm)
The mono-State oxygen is produced, and further reacts with water vapor to produce oh free radicals.
Water vapor is produced by purifying air through custom bubblesMade a humidifier
During the Photooxidation of naphthalene, the inlet ozone concentration remained at about 1ppm ppm.
Oh-free radicals and Nayl radicals produced by the reactionSOA.
Monitoring the benzene concentration at the inlet and outlet of the flow tube by gas chromatography-flame ionization detector (
GC/FID, model 8610C, SRI instruments.
NV, Las Vegas, USA)
With Tenax®TA trap
Particle size distribution and mass concentration of N-
Continuously monitor the SOA of the reactor outlet using a scanning mobile particle analyzer (SMPS)
Assuming the particle density is 1 g/cm, it is assembled in our laboratory.
SMPS combines a long differential mobile analyzer column (
MN Shoreview TSI 3081 USA)
With flow control and condensate particle counter (
MN Shoreview TSI 3772 USA).
Perform data inversion using custom code written in Igor Pro to get the size distribution (
Bobo watch in Portland or USA).
In all the experiments, the reactor temperature (22–25u2009°C)and humidity (
Flow Tube 30-40%)
Monitor using the Omega hx94 RH c RH/T transmitter.
Particle size distribution and volume concentration of N-
SOA is stable, N-
SOA is collected at the outlet of the flow tube to 47mm PTFE or prebaked quartz fiber filters (
Pall, Ann Arbor, MI, United States of America)
Stainless steel filter bracket.
After collection, the filter is stored at-20 °c.
Extraction of SOA using a 1:3 mixture of HPLC-grade methanol before animal exposure or chemical representation (99.
9%, Sigma Aldrich, St.
Louis, Missouri, USA)and Milli-Q water (18.
Monthly MΩ Kumar cm, Billerica, MA, USA, Millipore company).
To effectively extract SOA into the solution, each quartz filter is treated with ultrasound for at least 3 min at room temperature.
Analysis of SOA components using thermal analysis-gas chromatography mass spectrometry or TD-AnalysisGC/MS (
TDS3 in lülheim, Germany, and Del Ruhr Gerstel;
S. Santa Clara Agilent 7890B and 5977A models).
In short, a small noise of SOA filters (
SOA with about 13 μg)
It was put into the thermal analytic system, heated from 40 °c to 20 °c at 60 °c/min, and then kept for 5 min at 20 °c.
Carried by the helium body, the disadsorbed organic compound is captured and re-transmitted
Concentrated in a cooled lining at 20 °c
The liner is then heated to 20 °c and kept at 20 °c for 10 minutes to transfer all organic ingredients to GC/MS. An Rxi-
5 sil ms columns with dimensions of 29 m x 250250 m x u2009 0. 25u2009μm (
PA Bell special Restek Corporation, USA)
Used during measurement.
The temperature of the GC oven is increased from 50 °c to 300 °c at 10 °c/min and remains 5 °c min at 300 °c.
For the analysis of SOA extracts, the remaining filters are extracted in methanol/water (1:3)solution.
After ultrasonic filtration (
Clear quartz debris)
, 10 μ l of the extract (
SOA with about 7 μg)
Add to the punch of the blank prebaked quartz filter.
Then analyze the filter punch with the same method mentioned earlier.
ZnSiO of SOA (Sigma-Aldrich, St.
Louis, Missouri, USA)
Atomization of particle solutions using a collision nebulizer (
MN Shoreview TSI 3076 USA).
Remove water and methanol from particles by a custom method
Self-made diffusion dryer and charcoal diffuser (
Aerosol Dynamics Inc.
Berkeley, California, USA)Respectively ().
Simple dilution system with filter line (
Charcoal filter or Charcoal filter and metering valve)
Parallel side routes are used to control the SOA concentration within 50 μg/m of the desired concentration, ranging from 10 to 15 μg/m.
The particle flow is then mixed with ozone (
Produced by UV ozone generator)
And/or nitrogen, or enter the nose directly-
Exposure room only (Scireq Inc.
Montreal, Canada, QC).
Healthy female mice aged 8-10 weeks (
St. Charles River Laboratory
Constant, PQ, USA)
For all our studies.
To investigate the efficiency of the particle delivery method, mice were exposed to FA or znosio (
6 × 10 capsules/cm)for 2u2009hr.
Harvesting the lungs immediately and imaging under ultraviolet rays (
Excitation wavelength of 365 nm).
In a subset of mice, lung injection 1.
2 ml 5% of low melt Agar-
Hank's water solution of balance salt, cut into 50 μm thick slices using tissue slicer (EMS-
4000, electronic microscope science, Fort Washington, PA).
Image obtained using Zeiss fluorescence microscope (Observer.
John Wood Carl Zeiss microscope Z1, New York, USA)
The exposure time of fluorescence is rwms and 80 rwms (
Green, excitation wavelength 365 nm)and bright-
On-site image acquisition, respectively.
The exposure duration of 1 hour produced similar observations, so in subsequent N-SOA exposures. We chose N-
1 hour/day SOA exposure to simulate the duration of exposure to traffic-related air pollutants by the average city commuter.
Exposure for 3 consecutive days. N-SOA (
10, 30, 100, 15 μg/m), ozone (65u2009ppb)and NO (100u2009ppb)
Keep it at a constant level to simulate the level of the environment.
Particle size distribution, quantity and volume concentration during exposure were monitored using SMPS.
Monitoring of ozone and NO concentrations using an ultraviolet luminosity ozone analyzer (
American, horse, Waltham, Hot Scienceand NO-NO-NO analyzer (
42 I, Thermal Science, Waltham, MA, United States), respectively. Twenty-
After 4 hours of the last exposure, the mice were anesthesia with ketamine ketone (50u2009mg/kg i. p.
Whites' Animal Health Center, Guelph, Canada)and xylazine (10u2009mg/kg i. p. , Bayern Inc.
Toronto, Canada)
Airway reactivity to Azolin was measured using a flexiVent system (Scireq Inc.
Montreal, Canada, QC)
, As mentioned earlier. Rocuronium (2u2009mg/kg i. p.
Sandoz, Canada
QC bocherville, Canada)
Administration during the lung function test to prevent respiratory drive artifact.
Baseline lung function was evaluated and a acholine response was then evaluated.
As mentioned earlier, immediately after the assessment of lung function, the mouse lungs were rinsed to assess the total number of BAL liquid white blood cells.
In a subset of mice, the lungs were harvested for histological analysis or stored at-80 °c.
Extraction, inflation and embedding of lung with more than 4% formaldehyde (
Electronic microscope science in PA Hatfield, USA)
Pressure to reach 25 HO cm HO.
Then prepare the paraffin block and slice it (5u2009μm thickness)
Using Microm HM 325 (Microm GmbH.
Waldov, Germany).
Stained with isseri red (H&E)
As mentioned earlier, imaging with an inverted Leica dm il microscope using the inverted and 20x targets and Olympus DP71 cameras.
The average standard error of the data represented as the average value (S. E. M. ).
As mentioned earlier, statistical analysis of lung function data was performed.
Dose of Azolin-
Using F-to compare the response curve of Rtest. 1-
Way ANOVA with post
The comparison between multiple groups uses a special comparison with the multiple comparison test of Dunn.
The difference is considered to be significant when the diff