| 1. |
- Beal, Jacob, et al.
(författare)
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Robust estimation of bacterial cell count from optical density
- 2020
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Ingår i: Communications Biology. - : Springer Science and Business Media LLC. - 2399-3642. ; 3:1
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Tidskriftsartikel (refereegranskat)abstract
- Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data.
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| 2. |
- Eguiluz-Gracia, Ibon, et al.
(författare)
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The need for clean air : The way air pollution and climate change affect allergic rhinitis and asthma
- 2020
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Ingår i: Allergy: European Journal of Allergy and Clinical Immunology. - : Wiley. - 0105-4538. ; 75:9, s. 2170-2184
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Forskningsöversikt (refereegranskat)abstract
- Air pollution and climate change have a significant impact on human health and well-being and contribute to the onset and aggravation of allergic rhinitis and asthma among other chronic respiratory diseases. In Westernized countries, households have experienced a process of increasing insulation and individuals tend to spend most of their time indoors. These sequelae implicate a high exposure to indoor allergens (house dust mites, pets, molds, etc), tobacco smoke, and other pollutants, which have an impact on respiratory health. Outdoor air pollution derived from traffic and other human activities not only has a direct negative effect on human health but also enhances the allergenicity of some plants and contributes to global warming. Climate change modifies the availability and distribution of plant- and fungal-derived allergens and increases the frequency of extreme climate events. This review summarizes the effects of indoor air pollution, outdoor air pollution, and subsequent climate change on asthma and allergic rhinitis in children and adults and addresses the policy adjustments and lifestyle changes required to mitigate their deleterious effects.
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| 3. |
- Yang, Liu, et al.
(författare)
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Exposure to greenness, air pollution and respiratory health among pre-school children in northern China
- 2023
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Ingår i: Atmospheric Environment. - : Elsevier. - 1352-2310 .- 1873-2844. ; 298
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Tidskriftsartikel (refereegranskat)abstract
- Background: Evidence from developed countries on the association between greenspace and childhood respira-tory health has been inconsistent whilst such evidence is largely lacking in the developing world where rapid urbanization is occurring. This study aimed to investigate the associations between surrounding greenness, air pollution and respiratory health among pre-school children in a rapidly developing city in China.Methods: We recruited 2920 pre-school children in Taiyuan city. Greenness exposure was represented by the Normalized Difference Vegetation Index (NDVI) which combined estimations based on a weighted mean that children spend time both in kindergarten and home (75% home, 25% kindergarten). Air pollution exposures were estimated from a land-use-regression model which was also calculated based on a weighted mean as with greenness. Logistic regression was performed to assess the relationships between greenness, air pollution and respiratory symptoms.Results: Greenness had negatively impacted respiratory health among pre-school children in Taiyuan city, particularly for current dry cough at night. A 0.1-unit increment for NDVI300m was associated with an Odds Ratio (OR) of 2.45 (95%CI: 1.33-4.53) for dry cough at night. The associations were robust after adjusting for air pollution and road condition. No statistically significant associations were found between air pollution and any symptoms. The mediating effect of air pollution on dry cough at night with greenness was not observed.Conclusion: Our study found that within different buffers, a higher level of greenness was consistently associated with a higher risk of dry cough at night among pre-school children. This finding has indicated that environmental policies on urban greening should be scientifically justified to protect respiratory health among young children.
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