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Objective To construct an air health index (AHI) based on the exposure-response relationships of air pollution and ambient temperature with the years of life lost (YLL) in Tianjin. Methods The time series database of air pollution, meteorological factors, and non-accidental YLL from 2014-2019 in six urban areas of Tianjin were established. The data from 2014 to 2017 were used as the construction set to establish the exposure-response relationships of air pollution and ambient temperature with non-accidental YLL and establish the AHI model. The data from 2018 to 2019 were used as the validation set for verifying AHI. The generalized additive model (GAM) and weighted quantile sum (WQS) model were used to establish the exposure-response relationship between air pollution mixtures and non-accidental YLL. The distributed lag nonlinear model (DLNM) was fitted to assess the exposure-response relationship between ambient temperature and non-accidental YLL. Based on these obtained coefficients, the AHI and air quality health index (AQHI) were built. By comparing the associations between AHI, air quality health index (AQHI), and air quality index (AQI) with daily mortality and YLL and model goodness of fit to evaluate the validity of AHI. Results The formula for AHIt=EYLLt,air pollution+ambient temperature/475.11*10. The validation results showed that each IQR increase in AHI was associated with a higher increase in non-accidental mortality and YLL (10.61% and 353.37 person-year) compared with the corresponding values of AQHI and AQI. In addition, the model goodness of AHI was better than AQHI and AQI model. Conclusion Compared with AQHI and AQI, the AHI based on the integrating health effects of air pollution and ambient temperature has a better health risk prediction ability.
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Background Adverse health effects associated with particulate matter have been demonstrated, but findings on seasonal variation in the health impacts are inconsistent. Objective To explore potential seasonal variation in particulate matter (PM2.5 and PM10) associated daily non-accidental mortality and corresponding years of life loss (YLL) in Tianjin. Methods The daily data of non-accidental deaths, air pollution, and meteorological factors in Tianjin from 2014 to 2019 were collected. A generalized additive model, with adjusting selected confounding factors such as temperature, relative humidity, long-term trends, day of the week, and holiday, was used to quantitatively evaluate the relationships of PM2.5 and PM10 with daily non-accidental deaths and YLL. Results The effects of PM2.5 and PM10 on daily non-accidental mortality and corresponding YLL were statistically significant in full year, spring, summer, and autumn (except for the effect of PM10 on non-accidental YLL in spring), but not statistically significant in winter. The non-accidental mortality and it's 95%CI increased by 0.28% (0.11%-0.44%) and 0.24% (0.11%-0.36%) in full year, 0.44% (0.11%-0.77%) and 0.17% (0.00%-0.33%) in spring, 1.32% (0.50%-2.16%) and 2.15% (1.54%-2.76%) in summer, and 0.68% (0.30%-1.06%) and 0.57% (0.28%-0.87%) in autumn for every 10 µg·m−3 increase in PM2.5 and PM10 concentrations, respectively; the corresponding YLL and it's 95%CI increased by 7.41 (2.42-13.07) and 5.75 (1.94-9.57), 13.11 (3.00-23.22) and 2.88 (−2.82-8.59), 34.66 (11.92-57.40) and 48.12 (31.48-64.75), and 16.13 (4.57-27.70) and 12.60 (3.56-21.65) person-years, respectively. When adopting the limits in the Global Air Quality Guidelines (2021) as the reference, excess deaths and YLL caused by PM2.5 and PM10 exposure were the greatest in summer. The excess deaths and it's 95%CI were 5.38 (5.08-5.69) and 8.62 (7.95-9.28), and the excess YLL and it's 95%CI were 112.23 (105.79-118.67) and 156.94 (44.99-168.89) person-years, respectively. Conclusion The effects of particulate matter on non-accidental mortality and corresponding YLL may vary seasonally in Tianjin with the greatest effects in summer, suggesting that the health protection related to particulate matter should be strengthened in summer.
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Objective To investigate whether and what staining techniques are applied to the ultrathin sheet plastination slice and whether the stained specimen is of autofluorescences .Methods A cadaveric hand block was plastinated and then sectioned as a series of 300-400μm thick transverse sections .A total of 56 slices in total .Alternative sections were stained with hematoxylin -eosin staining ( HE) , Verhoeff -Van Gieson staining ( VVG) or methylene blue and azureⅡstaining(MA).The stained slices were examined under a light microscope and a confocal microscope .Results The plastinated slices were stained with the three staining methods .HE staining revealed the muscle and connective tissues were red or violet , bone was violet or blue;VVG staining showed the elastic fibers was black , the collagen was red , and other tissues were yellow .MA staining showed the tendon was violet , the bone was pink , cartilage was violet , and other tissues were purple.However, the intracellular structures appeared not very well stained .The collagen, elastin and muscular structures in the stained slices were observed under a confocal microscope .Conclusion The commonly used histology staining methods can be used to stain the ultrathin sheet plastination slices .The staining provides a better observation of various tissues in the slice than the unstained slice .After staining, those autofluorescent structures in the plastinated slice are detectable under a confocal microscope .