| 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. |
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- 2019
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Tidskriftsartikel (refereegranskat)
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| 3. |
- Chen, Gongbo, et al.
(författare)
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All-cause, cardiovascular, and respiratory mortality and wildfire-related ozone : a multicountry two-stage time series analysis
- 2024
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Ingår i: The Lancet Planetary Health. - : Elsevier. - 2542-5196. ; 8:7, s. e452-e462
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Tidskriftsartikel (refereegranskat)abstract
- Background: Wildfire activity is an important source of tropospheric ozone (O3) pollution. However, no study to date has systematically examined the associations of wildfire-related O3 exposure with mortality globally.Methods: We did a multicountry two-stage time series analysis. From the Multi-City Multi-Country (MCC) Collaborative Research Network, data on daily all-cause, cardiovascular, and respiratory deaths were obtained from 749 locations in 43 countries or areas, representing overlapping periods from Jan 1, 2000, to Dec 31, 2016. We estimated the daily concentration of wildfire-related O3 in study locations using a chemical transport model, and then calibrated and downscaled O3 estimates to a resolution of 0·25° × 0·25° (approximately 28 km2 at the equator). Using a random-effects meta-analysis, we examined the associations of short-term wildfire-related O3 exposure (lag period of 0–2 days) with daily mortality, first at the location level and then pooled at the country, regional, and global levels. Annual excess mortality fraction in each location attributable to wildfire-related O3 was calculated with pooled effect estimates and used to obtain excess mortality fractions at country, regional, and global levels.Findings: Between 2000 and 2016, the highest maximum daily wildfire-related O3 concentrations (≥30 μg/m3) were observed in locations in South America, central America, and southeastern Asia, and the country of South Africa. Across all locations, an increase of 1 μg/m3 in the mean daily concentration of wildfire-related O3 during lag 0–2 days was associated with increases of 0·55% (95% CI 0·29 to 0·80) in daily all-cause mortality, 0·44% (–0·10 to 0·99) in daily cardiovascular mortality, and 0·82% (0·18 to 1·47) in daily respiratory mortality. The associations of daily mortality rates with wildfire-related O3 exposure showed substantial geographical heterogeneity at the country and regional levels. Across all locations, estimated annual excess mortality fractions of 0·58% (95% CI 0·31 to 0·85; 31 606 deaths [95% CI 17 038 to 46 027]) for all-cause mortality, 0·41% (–0·10 to 0·91; 5249 [–1244 to 11 620]) for cardiovascular mortality, and 0·86% (0·18 to 1·51; 4657 [999 to 8206]) for respiratory mortality were attributable to short-term exposure to wildfire-related O3.Interpretation: In this study, we observed an increase in all-cause and respiratory mortality associated with short-term wildfire-related O3 exposure. Effective risk and smoke management strategies should be implemented to protect the public from the impacts of wildfires.
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| 4. |
- Lin, Dongxu, et al.
(författare)
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The selection strategy of ammonium-group organic salts in vapor deposited perovskites: From dimension regulation to passivation
- 2021
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Ingår i: Nano Energy. - : ELSEVIER. - 2211-2855 .- 2211-3282. ; 84
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Tidskriftsartikel (refereegranskat)abstract
- Dimension regulation and defect passivation are two key strategies for highly efficient and stable perovskite solar cell. Vapor deposition of perovskite is a toxic-solvent-free method for large-scale fabrication. However, without the assistance of solvent for crystal optimization, effective structural regulation and defect passivation become challenging. Here, detailed investigations on the structural evolution of perovskite thin film are carried out in sequential vapor deposition using mixed-vapor (R-NH3I/MAI). Correlation between electron donating ability of R-NH3I (BAI, PEAI, PMAI and ALI) molecule and the way of structural transition is established. It is found that RNH3I with stronger electron-donating ability promoted the phase transition from three-dimensional (3D) to twodimensional (2D) perovskite. Typically, the n value from 1 to 5 can be tuned by reaction time or component control using BAI with the strongest electron donating ability. R-NH3I with weak electron-donating ability suppresses the 3D to 2D transition, but enhances the defect passivation effect. The ALI with the weakest electron donating ability shows the best passivation effect, leading to the best device performance than that of the control 3D device, with PCE of 18.23% (0.045 cm2) and 15.48% (1 cm2) and the significantly improved stability. This study provides the evidence that the concept of Lewis acid-base reaction is applicable in vapor deposition, which provides us with the selection guide of R-NH3I molecules for structural design in vapor fabrication of perovskite thin film.
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| 5. |
- Cai, Tingting, et al.
(författare)
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Human cortical neural correlates of visual fatigue during binocular depth perception : An fNIRS study
- 2017
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Ingår i: PLOS ONE. - : PUBLIC LIBRARY SCIENCE. - 1932-6203. ; 12:2
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Tidskriftsartikel (refereegranskat)abstract
- Functional near-infrared spectroscopy (fNIRS) was adopted to investigate the cortical neural correlates of visual fatigue during binocular depth perception for different disparities (from 0.1 degrees to 1.5 degrees). By using a slow event-related paradigm, the oxyhaemoglobin (HbO) responses to fused binocular stimuli presented by the random-dot stereogram (RDS) were recorded over the whole visual dorsal area. To extract from an HbO curve the characteristics that are correlated with subjective experiences of stereopsis and visual fatigue, we proposed a novel method to fit the time-course HbO curve with various response functions which could reflect various processes of binocular depth perception. Our results indicate that the parietal-occipital cortices are spatially correlated with binocular depth perception and that the process of depth perception includes two steps, associated with generating and sustaining stereovision. Visual fatigue is caused mainly by generating stereovision, while the amplitude of the haemodynamic response corresponding to sustaining stereovision is correlated with stereopsis. Combining statistical parameter analysis and the fitted time-course analysis, fNIRS could be a promising method to study visual fatigue and possibly other multi-process neural bases.
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| 6. |
- Chen, Gongbo, et al.
(författare)
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Mortality risk attributable to wildfire-related PM2·5 pollution : a global time series study in 749 locations
- 2021
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Ingår i: The Lancet Planetary Health. - : Elsevier. - 2542-5196. ; 5:9, s. e579-e587
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Many regions of the world are now facing more frequent and unprecedentedly large wildfires. However, the association between wildfire-related PM2·5 and mortality has not been well characterised. We aimed to comprehensively assess the association between short-term exposure to wildfire-related PM2·5 and mortality across various regions of the world.METHODS: For this time series study, data on daily counts of deaths for all causes, cardiovascular causes, and respiratory causes were collected from 749 cities in 43 countries and regions during 2000-16. Daily concentrations of wildfire-related PM2·5 were estimated using the three-dimensional chemical transport model GEOS-Chem at a 0·25° × 0·25° resolution. The association between wildfire-related PM2·5 exposure and mortality was examined using a quasi-Poisson time series model in each city considering both the current-day and lag effects, and the effect estimates were then pooled using a random-effects meta-analysis. Based on these pooled effect estimates, the population attributable fraction and relative risk (RR) of annual mortality due to acute wildfire-related PM2·5 exposure was calculated.FINDINGS: 65·6 million all-cause deaths, 15·1 million cardiovascular deaths, and 6·8 million respiratory deaths were included in our analyses. The pooled RRs of mortality associated with each 10 μg/m3 increase in the 3-day moving average (lag 0-2 days) of wildfire-related PM2·5 exposure were 1·019 (95% CI 1·016-1·022) for all-cause mortality, 1·017 (1·012-1·021) for cardiovascular mortality, and 1·019 (1·013-1·025) for respiratory mortality. Overall, 0·62% (95% CI 0·48-0·75) of all-cause deaths, 0·55% (0·43-0·67) of cardiovascular deaths, and 0·64% (0·50-0·78) of respiratory deaths were annually attributable to the acute impacts of wildfire-related PM2·5 exposure during the study period.INTERPRETATION: Short-term exposure to wildfire-related PM2·5 was associated with increased risk of mortality. Urgent action is needed to reduce health risks from the increasing wildfires.
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| 7. |
- Chen, Tianyi, et al.
(författare)
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Maternal exposure to PM2.5/BC during pregnancy predisposes children to allergic rhinitis which varies by regions and exclusive breastfeeding
- 2022
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Ingår i: Environment International. - : Elsevier. - 0160-4120 .- 1873-6750. ; 165
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundIncreasing prevalence of childhood allergic rhinitis(AR) needs a deeper understanding on the potential adverse effects of early life exposure to air pollution.ObjectivesThe main aim was to evaluate the effects of maternal exposure to PM2.5 and chemical constituents during pregnancy on preschool children’s AR, and further to explore the modification effects of regions and exclusive breastfeeding.MethodsA multi-center population-based study was performed in 6 cities from 3 regions of China in 2011–2012. Maternal exposure to ambient PM2.5 and main chemical constituents(BC, OM, SO42−, NO3−, NH4+) during pregnancy was assessed and a longitudinal prospective analysis was applied on preschool children’s AR. The modification effects of regions and exclusive breastfeeding were investigated.ResultsA total of 8.8% and 9.8% of children reported doctor-diagnosed allergic rhinitis(DDAR) and current hay fever, respectively, and 48.6% had less than 6 months of exclusive breastfeeding. The means of PM2.5 during pregnancy were 52.7 μg/m3, 70.3 μg/m3 and 76.4 μg/m3 in the east, north and central south of China, respectively. Multilevel log-binomial model regression showed that each interquartile range(IQR) increase of PM2.5 during pregnancy was associated with an average increase in prevalence ratio (PR) of DDAR by 1.43(95% confidence interval(CI): 1.11, 1.84) and current hay fever by 1.79(95% CI: 1.26, 2.55), respectively. Among chemical constituents, black carbon (BC) had the strongest associations. Across 3 regions, the eastern cities had the highest associations, followed by those in the central south and the north. For those equal to or longer than 6 months of exclusive breastfeeding, the associations were significantly reduced.ConclusionsChildren in east of China had the highest risks of developing AR per unit increase of maternal exposure to PM2.5 during pregnancy, especially BC constituent. Remarkable decline was found in association with an increase in breastfeeding for ≥6 months, in particular in east of China.
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| 8. |
- Cheng, Hong, et al.
(författare)
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Home environment exposure and sick building syndrome (SBS) symptoms among adults in southern China : Health associations in 2010 and 2019
- 2024
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Ingår i: Building and Environment. - : Elsevier. - 0360-1323 .- 1873-684X. ; 248
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Tidskriftsartikel (refereegranskat)abstract
- We studied time trends in home environment and sick building syndrome (SBS) symptoms in a repeat study in five cities in southern China. Moreover, we studied associations between home environment exposure and SBS symptoms. Parents from randomly selected day care centers were invited. One parent per family answered a questionnaire on the home environment and their own SBS symptoms. Data collection was performed in two surveys in 2010 and 2019 (27,292 participants in 2010 and 32,073 in 2019). We used two-level logistic regression to analyze health associations. Asthma decreased from 1.7% to 1.5% (P < 0.05) but allergic rhinitis increased from 6.5% to 16.4% (P < 0.001). All SBS symptoms decreased from 2010 to 2019 (all P < 0.001). Most aspects of the home environment improved from 2010 to 2019 but there were less cleaning, more cats, dogs, and urbanization in 2019. Redecoration, new furniture, and pests were associated with most types of SBS symptoms, similarly in 2010 and 2019. Environmental tobacco smoke (ETS) was associated with SBS symptoms in 2019 only. In conclusion, prevalence of SBS symptoms among young parents in southern China decreased from 2010 to 2019 but allergic rhinitis increased. Cockroaches, rats, mice, mosquitoes or flies can be consistent biological risk factors for SBS symptoms. Redecoration, buying new furniture and traffic air pollution are other risk factors for SBS symptoms. Daily cleaning, frequently putting bedding to sunshine, and having a fan in the bathroom can be protective factors. ETS is an emerging risk factor for SBS symptoms.
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| 9. |
- Cong, Lin, et al.
(författare)
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Use of Cardiovascular Drugs for Primary and Secondary Prevention of Cardiovascular Disease Among Rural-Dwelling Older Chinese Adults
- 2020
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Ingår i: Frontiers in Pharmacology. - : Frontiers Media SA. - 1663-9812. ; 11
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Tidskriftsartikel (refereegranskat)abstract
- Cardiovascular risk factors and related disorders are common among older adults, and use of various classes of cardiovascular (CV) drugs could reduce the risk of cardiovascular disease (CVD). However, data are sparse with regard to the use of CV drugs among rural-dwelling older adults in China. Therefore, this population-based study aimed to describe use of CV drugs among older adults living in the rural communities in China, while taking into account the use of CV drugs for primary and secondary prevention of CVDs. This study included 5,246 participants (age >= 65 years; 57.17% women; 40.68% illiteracy) in the baseline examination of the MIND-China study. In March-September 2018, data on health-related factors, CVDs (ischemic heart disease, atrial fibrillation, heart failure, and stroke), and CV drug use were collected via face-to-face survey, clinical examination, and laboratory tests. We classified CV drugs according to the Anatomical Therapeutic Chemical classification system for western medications and specific cardiovascular effects for the products of traditional Chinese medicine (TCM). We conducted descriptive analysis. The overall prevalence of major cardiovascular risk factors ranged from 14.30% in diabetes and 23.81% in dyslipidemia to 66.70% in hypertension, and CVDs affected 35.07% of all participants (36.28% in women vs. 33.47% in men, p = 0.035). In the total sample, calcium channel blockers (C08) were most commonly used (10.39%), followed by TCM products (7.64%), hypoglycemic agents (A10, 4.73%), renin-angiotensin system (RAS)-acting agents (C09, 4.61%), and lipid-lowering agents (C10, 4.17%). The proportions of CV drugs for primary prevention (i.e., use of CV drugs among people without CVD) were 3.14% for antithrombotic agents (mainly aspirin), 1.38% for lipid-lowering agents, and 3.11% for RAS-acting agents; the corresponding figures for secondary prevention (i.e., use of CV drugs among people with CVD) were 13.97%, 9.35%, and 7.39%. In conclusion, despite highly prevalent cardiovascular risk factors and CVDs, a fairly low proportion of the rural-dwelling older adults take CV medications for primary and secondary prevention. Notably, TCM products are among the most commonly used CV drugs. These results call for additional efforts to promote implementation of the evidence-based recommendations for prevention of CVDs in the primary care settings.
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| 10. |
- Du, Chenqiu, et al.
(författare)
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Home dampness/mold(D/M) improvement in children's residences over the past decade in China-a comparison of repeated surveys in 2010 and 2019
- 2021
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Ingår i: Building and Environment. - : Elsevier. - 0360-1323 .- 1873-684X. ; 205
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Tidskriftsartikel (refereegranskat)abstract
- There is mounting evidence that exposure to household dampness/mold (D/M) is the cause of respiratory, allergic diseases for children. While few research focuses on the effects caused by building environment changes, from a longitudinal investigation perspective, especially for China experiencing a rapid development in recent years. This study aimed to explore the changes of D/M in Chinese homes over the past 10 years and identify the impacts of climate, building energy efficiency and residents' behaviors. The cross-sectional surveys were repeatedly conducted in children' residences in 2010 (Period I) and 2019 (Period II), among Taiyuan, Urumqi in northern China, and Nanjing, Shanghai, Wuhan, Changsha, Chongqing in southern China. Finally, 23465 children in Period I and 34720 children in Period II were involved, with no changes of residences since birth. The results showed that the proportions for reported D/M indicators were significantly reduced in Period II: e.g., 93.8% and 84.1% residents respectively answered no visible mold spots and damp stains in current residences, compared to only 78.3% and 62.2% in Period I. Southern homes accounted for high proportions for D/M indicator occurrences; warm-humid climate, annual higher precipitation and lower sunshine hours, etc., exacerbated the indoor D/M exposure risks. While residents' behaviors like ventilation, airing quilt/beddings, regular cleaning ameliorated the reported D/M significantly. The findings, from a temporal and spacious dimension perspective, advance our understanding of indoor D/M changes, precisely improvement in children' homes over the past 10 years, benefiting to promote indoor air quality standards in China.
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