Spatiotemporal distribution of oxidative potential in PM2.5 and its key components across six Chinese cities.

Increasing evidence has supported that oxidative potential (OP) serves as a crucial indicator of health risk of exposure to PM2.5 over mass concentration. However, there is a lack of comparative studies across multiple cities, particularly on a fine temporal scale. In this study, we aim to investigate daily variation of ambient PM2.5 OP through simultaneous samplings in six Chinese cities for one year. Results showed that more than 60 % of the sampling days exhibited non-zero ranking difference between volume-normalized oxidative potential (OPv) and mass concentration among the six cities. Key components contributing to OPv inculde Mn, NO3-, and K+, followed by Ca2+, Al, SO42-, Cl-, Fe, and NH4+. Based on these chemical components, we developed a stepwise multivariable linear regression model (R2: 0.71) for OPv prediction. The performance of the model is comparable to both species- and sources-based ones in the literature. These findings suggest that a relatively lower daily-averaged mass concentration of PM2.5 does not necessarily indicate a lower oxidative risk. Future studies and policy developments on health benefits should also consider OPv rather than mass concentration alone. Priority could be given to sources/species that contribute significantly to oxidative potential of ambient PM2.5. SYNOPSIS: This study highlights inclusion of oxidative potential as a complementary metric for air pollution assessment and control.

The burden of disease attributable to indoor air pollutants in China from 2000 to 2017.

BACKGROUND: High-level exposure to indoor air pollutants (IAPs) and their corresponding adverse health effects have become a public concern in China in the past 10 years. However, neither national nor provincial level burden of disease attributable to multiple IAPs has been reported for China. This is the first study to estimate and rank the annual burden of disease and the financial costs attributable to targeted residential IAPs at the national and provincial level in China from 2000 to 2017. METHODS: We first did a systematic review and meta-analysis of 117 articles from 37 231 articles identified in major databases, and obtained exposure-response relationships for the candidate IAPs. The exposure levels to these IAPs were then collected by another systematic review of 1864 articles selected from 52 351 articles. After the systematic review, ten IAPs with significant and robust exposure-response relationships and sufficient exposure data were finally targeted: PM2·5, nitrogen dioxide, sulphur dioxide, ozone, carbon monoxide, radon, formaldehyde, benzene, toluene, and p-dichlorobenzene. The annual exposure levels in residences were then evaluated in all 31 provinces in mainland China continuously from 2000 to 2017, using the spatiotemporal Gaussian process regression model to analyse indoor originating IAPs, and the infiltration factor method to analyse outdoor originating IAPs. The disability-adjusted life-years (DALYs) attributable to the targeted IAPs were estimated at both national and provincial levels in China, using the population attributable fraction method. Financial costs were estimated by an adapted human capital approach. FINDINGS: From 2000 to 2017, annual DALYs attributable to the ten IAPs in mainland China decreased from 4620 (95% CI 4070-5040) to 3700 (3210-4090) per 100 000. Nevertheless, in 2017, IAPs still ranked third among all risk factors, and their DALYs and financial costs accounted for 14·1% (95% CI 12·3-15·6) of total DALYs and 3·45% (3·01-3·82) of the gross domestic product. Specifically, the rank of ten targeted IAPs in order of their contribution to DALYs in 2017 was PM2·5, carbon monoxide, radon, benzene, nitrogen dioxide, ozone, sulphur dioxide, formaldehyde, toluene, and p-dichlorobenzene. The DALYs attributable to IAPs were 9·50% higher than those attributable to outdoor air pollution in 2017. For the leading IAP, PM2·5, the DALYs attributable to indoor origins are 18·3% higher than those of outdoor origins. INTERPRETATION: DALYs attributed to IAPs in China have decreased by 20·0% over the past two decades. Even so, they are still much higher than those in the USA and European countries. This study can provide a basis for determining which IAPs to target in various indoor air quality standards and for estimating the health and economic benefits of various indoor air quality control approaches, which will help to reduce the adverse health effects of IAPs in China. FUNDING: The National Key Research and Development Program of China and the National Natural Science Foundation of China.

Deep learn-based computer-assisted transthoracic echocardiography: approach to the diagnosis of cardiac amyloidosis.

Myocardial amyloidosis (CA) differs from other etiological pathologies of left ventricular hypertrophy in that transthoracic echocardiography is challenging to assess the texture features based on human visual observation. There are few studies on myocardial texture based on echocardiography. Therefore, this paper proposes an adaptive machine learning method based on ultrasonic image texture features to identify CA. In this retrospective study, a total of 289 participants (50 cases of myocardial amyloidosis; Hypertrophic cardiomyopathy: 70 cases; Uremic cardiomyopathy: 92 cases; Hypertensive heart disease: 77 cases). We extracted the myocardial ultrasonic imaging features of these patients and screened the features, and four models of random forest (RF), support vector machine (SVM), logistic regression (LR) and gradient decision-making lifting tree (GBDT) were established to distinguish myocardial amyloidosis from other diseases. Finally, the diagnostic efficiency of the model was evaluated and compared with the traditional ultrasonic diagnostic methods. In the overall population, the four machine learning models we established could effectively distinguish CA from nonCA diseases, AUC (RF 0.77, SVM 0.81, LR 0.81, GBDT 0.71). The LR model had the best diagnostic efficiency with recall, F1-score, sensitivity and specificity of 0.21, 0.34, 0.21 and 1.0, respectively. Slightly better than the traditional ultrasonic diagnosis model. In further subgroup analysis, the myocardial amyloidosis group was compared one-by-one with the patients with hypertrophic cardiomyopathy, uremic cardiomyopathy, and hypertensive heart disease groups, and the same method was used for feature extraction and data modeling. The diagnostic efficiency of the model was further improved. Notably, in identifying of the CA group and HHD group, AUC values reached more than 0.92, accuracy reached more than 0.87, sensitivity equal to or greater than 0.81, specificity 0.91, and F1 score higher than 0.84. This novel method based on echocardiography combined with machine learning may have the potential to be used in the diagnosis of CA.

Lung cancer as adverse health effect by indoor radon exposure in China from 2000 to 2020: A systematic review and meta-analysis.

Indoor radon exposure is thought to be associated with adverse health effect as lung cancer. Lung cancer incidences in China have been the highest worldwide during the past two decades. It is important to quantitively address indoor radon exposure and its health effect, especially in countries like China. In this paper, we have conducted a meta-analysis based on indoor radon and its health effect studies from a systematic review between 2000 and 2020. A total of 8 studies were included for lung cancer. We found that the relative risk (RR) was 1.01 (95% CI: 1.01-1.02) per 10 Bq/m3 increase of indoor radon for lung cancer in China. The subgroup analysis found no significant difference between the conclusions from the studies from China and other regions. The health effect of indoor radon exposure is relatively consistent for the low-exposure and high-exposure groups in the subgroup analysis. With a better understanding of exposure level of indoor radon, the outcomes and conclusions of this study will provide supports for next phase of researches on estimation of environmental burden of disease by indoor radon exposures in countries like China.

CD36-mediated metabolic crosstalk between tumor cells and macrophages affects liver metastasis.

Liver metastasis is highly aggressive and treatment-refractory, partly due to macrophage-mediated immune suppression. Understanding the mechanisms leading to functional reprogramming of macrophages in the tumor microenvironment (TME) will benefit cancer immunotherapy. Herein, we find that the scavenger receptor CD36 is upregulated in metastasis-associated macrophages (MAMs) and deletion of CD36 in MAMs attenuates liver metastasis in mice. MAMs contain more lipid droplets and have the unique capability in engulfing tumor cell-derived long-chain fatty acids, which are carried by extracellular vesicles. The lipid-enriched vesicles are preferentially partitioned into macrophages via CD36, that fuel macrophages and trigger their tumor-promoting activities. In patients with liver metastases, high expression of CD36 correlates with protumoral M2-type MAMs infiltration, creating a highly immunosuppressive TME. Collectively, our findings uncover a mechanism by which tumor cells metabolically interact with macrophages in TME, and suggest a therapeutic potential of targeting CD36 as immunotherapy for liver metastasis.

Indoor exposure to phthalates and its burden of disease in China.

China's profoundly rapid modernization in the past two decades has resulted in dramatic changes in indoor environmental exposures. Among these changes, exposure to phthalates has attracted increasing attention. We aimed to characterize indoor phthalate exposure and to estimate the disease burden attributable to indoor phthalate pollution from 2000 to 2017 in China. We integrated the national exposure level of indoor phthalates from literature through systematic review and Monte Carlo simulation. Dose-response relationships between phthalate exposure and health outcomes were obtained by systematic review and meta-analysis. Based on existing models for assessing probabilities of causation and a comprehensive review of available data, we calculated the disability-adjusted life years (DALYs) among the general Chinese population resulting from exposure to indoor phthalate pollution. We found that DnBP, DiBP, and DEHP were the most abundant phthalates in indoor environments of residences, offices, and schools with medians of national dust phase concentration from 74.5 µg/g to 96.3 µg/g, 39.6 µg/g to 162.5 µg/g, 634.2 µg/g to 1,394.7 µg/g, respectively. The national equivalent exposure for children to phthalates in settled dust was higher than that of adults except for DiBP and DnOP. Dose-response relationships associated with DEP, DiBP, DnBP, BBzP, and DEHP exposures were established. Between 2000 and 2017, indoor phthalate exposure in China has led to 3.32 million DALYs per year, accounting for 0.90% of total DALYs across China. The annual DALY associated with indoor phthalate pollution in China was over 2000 people per million, which is about 2~3 times of the DALY loss due to secondhand smoke (SHS) in six European countries or the sum of the DALY loss caused by indoor radon and formaldehyde in American homes. Our study indicates a considerable socioeconomic impact of indoor phthalate exposure for a modernizing human society. This suggest the need for relevant national standard and actions to reduce indoor phthalate exposure.

Indoor exposure levels of radon in dwellings, schools, and offices in China from 2000 to 2020: A systematic review.

After decades of development, the indoor environment in China has changed. A systematic review was conducted from peer-reviewed scientific papers with field test data of indoor radon in China from 2000 to 2020 for three types of buildings. The mean concentrations of indoor radon for dwellings, school buildings, and office buildings are 54.6, 56.1, and 54.9 Bq/m3 . The indoor radon concentration was related to seasons, climate regions, ventilation, decoration, and other factors such as soil and outdoor air. Colder seasons, especially in severe colder areas of China, newer decorated buildings, closed windows, and doors were all associated with higher indoor radon concentrations. Variables like climate region and ventilation showed statistical significance in the correlation analysis. Regarding the increasing trend of indoor radon concentration in China during the last two decades, further study of indoor radon is necessary especially for school buildings and office buildings, and will help access its environmental burden of disease in China more accurately.

Indoor exposure levels of ammonia in residences, schools, and offices in China from 1980 to 2019: A systematic review.

Indoor ammonia (NH3 ) pollution has been paid more and more attention in view of its health risk. However, few studies have investigated the exposure level in the non-occupational environment in China. This study systematically reviewed the indoor ammonia exposure level in different regions, the equivalent exposure concentration of different populations, and the factors that influence indoor air ammonia in residences, offices, and schools in China. The literature published in 1980-2019 from main databases was searched and detailed screened, and finally, 56 related studies were selected. The results illustrated that the median concentration of indoor air ammonia in residences, offices, and school buildings was 0.21 mg/m3 , 0.26 mg/m3 , and 0.15 mg/m3 . There were 46.4%, 71.4%, and 40% of these samples exceeding the NH3  standard, respectively. The national concentrations and the equivalent exposure levels of adults and children were calculated and found to be higher than 0.20 mg/m3 . The concentration of ammonia varied greatly in different climate zones and economic development regions. Higher concentrations were found in the severe cold zone and the regions with higher economic level. This review reveals a high exposure risk of indoor air ammonia and the crucial impact of human emission, indoor air temperature, new concrete, and economic level, suggesting further investigation on indoor air ammonia evaluation and health effects.

High olive oil diets enhance cervical tumour growth in mice: transcriptome analysis for potential candidate genes and pathways.

BACKGROUND: Numerous epidemiologic studies have found a close association between obesity and cancer. Dietary fat is a fundamental contributor to obesity and is a risk factor for cancer. Thus far, the impact of dietary olive oil on cancer development remains inconclusive, and little is known about its underlying mechanisms. METHODS: Nude mouse xenograft models were used to examine the effects of high olive oil diet feeding on cervical cancer (CC) development and progression. Cell proliferation, migration and invasion were observed by the methods of EdU incorporation, Wound healing and Transwell assay, separately. RNA-sequencing technology and comprehensive bioinformatics analyses were used to elucidate the molecular processes regulated by dietary fat. Differentially expressed genes (DEGs) were identified and were functionally analyzed by Gene Ontology (GO), Kyoto Enrichment of Genes and Genomes (KEGG). Then, protein-protein interaction (PPI) network and sub-PPI network analyses were conducted using the STRING database and Cytoscape software. RESULTS: A high olive oil diet aggravated tumourigenesis in an experimental xenograft model of CC. Oleic acid, the main ingredient of olive oil, promoted cell growth and migration in vitro. Transcriptome sequencing analysis of xenograft tumour tissues was then performed to elucidate the regulation of molecular events regulated by dietary fat. Dietary olive oil induced 648 DEGs, comprising 155 up-regulated DEGs and 493 down-regulated DEGs. GO and pathway enrichment analysis revealed that some of the DEGs including EGR1 and FOXN2 were involved in the transcription regulation and others, including TGFB2 and COL4A3 in cell proliferation. The 15 most strongly associated DEGs were selected from the PPI network and hub genes including JUN, TIMP3, OAS1, OASL and EGR1 were confirmed by real-time quantitative PCR analysis. CONCLUSIONS: Our study suggests that a high olive oil diet aggravates CC progression in vivo and in vitro. We provide clues to build a potential link between dietary fat and cancerogenesis and identify areas requiring further investigation.

Anticoagulation in atrial fibrillation and cognitive decline: A systematic review and meta-analysis.

BACKGROUND: It is well known that atrial fibrillation (AF) carried a high risk of cognitive decline, which is independent of stroke or transient ischemic attack (TIA). Whether anticoagulation is associated with reduced risk of cognitive decline in participants with AF still remains controversial. We conducted a systematic review and meta-analysis to explore the effect of anticoagulation on the risk of cognitive decline in patients with AF. METHODS: We systematically searched the PubMed, Embase and the Cochrane Database for eligible studies published up to January 2018. Risk ratios (RR) with 95% confidence interval (CI) for cognitive decline were extracted, and pooled estimations were calculated using the fixed effects model. Subgroup analyses were further performed. RESULTS: Eight relevant articles involved 454,273 patients were ultimately included in this meta-analysis. We found that anticoagulation was associated with reduced risk of cognitive impairment as compared with nonanticoagulation (RR 0.72, 95% CI 0.69-0.75, I 11.5%). This reduction was still significant after adjustment for stroke and TIA (RR 0.72, 95% CI 0.69-0.74, I 0.0%). In the subgroup analyses, the incidence of cognitive decline was significantly decreased in those treated with anticoagulation compared to no treatment (RR 0.72, 95% CI 0.69-0.75, I 0.0%), but the cognitive benefit showed no significant difference between anticoagulant and antiplatelet treatment (RR 1.01, 95% CI 0.68-1.50, I 46.8%). CONCLUSION: Anticoagulation is associated with cognitive benefit in participants with AF independent of stroke and TIA, but it was not superior to antiplatelet drugs in reducing the risk of cognitive decline.

Dietary oleic acid-induced CD36 promotes cervical cancer cell growth and metastasis via up-regulation Src/ERK pathway.

Epidemiological and experimental studies have revealed strong associations between dietary lipids and cancer risk. However, the molecular mechanisms underlying the effects of dietary fatty acids on the genesis and progression of cancer have been poorly explored. In this study, we found that a high olive oil diet stimulated cervical cancer (CC) carcinogenesis, and oleic acid (OA), the main lipid in olive oil, was associated with increased malignancy in HeLa cells. OA up-regulated the expression of CD36, which is the best characterized fatty acid transporter. Inhibiting CD36 prevented the tumor-promoting effects of OA, while overexpressing CD36 mimicked the effects of OA. Clinically, CD36 expression was positively correlated with tumor progression and poor prognosis in patients with CC. Furthermore, OA induced Src kinase and downstream ERK1/2 pathway activation in a CD36-dependent manner. Pretreatment of HeLa cells with an Src kinase inhibitor largely blocked the tumor-promoting effect of OA. Our findings suggest that dietary OA exerts a stimulatory effect on CC growth and metastasis, and CD36 might be a promising therapeutic target that acts against CC through an Src/ERK-dependent signaling pathway.

Long-chain fatty acid activates hepatocytes through CD36 mediated oxidative stress.

BACKGROUND: Accumulating evidence suggests that activated hepatocytes are involved in the deposition of the excess extracellular matrix during liver fibrosis via the epithelial to mesenchymal transition. Lipid accumulation in hepatocytes are implicated in the pathogenesis of chronic liver injury. CD36 is known to mediate long-chain fatty acid (LCFA) uptake and lipid metabolism. However, it is unclear whether LCFA directly promotes hepatocyte activation and the involved mechanisms have not been fully clarified. METHODS: Mice were fed with a high fat diet (HFD) and normal hepatocyte cells (Chang liver cells) were treated with palmitic acid (PA) in vivo and in vitro. Real-time polymerase chain reaction (RT-PCR) and western blotting were used to examine the gene and protein expression of molecules involved in hepatic fibrogenesis and hepatocyte activation. CD36 was knocked down by transfecting CD36 siRNA into hepatocyte cells. Hydrogen peroxide (H2O2) and reactive oxygen species (ROS) levels were detected using commercial kits. RESULTS: HFD induced a profibrogenic response and up-regulated CD36 expression in vivo. Analogously, PA increased lipid accumulation and induced human hepatocyte activation in vitro, which was also accompanied by increased CD36 expression. Interestingly, knockdown of CD36 resulted in a reduction of hepatocyte lipid deposition and decreased expression of Acta2 (34% decrease), Vimentin (29% decrease), Desmin (60% decrease), and TGF-ß signaling pathway related genes. In addition, HFD and PA increased the production of H2O2 in vivo (48% increase) and in vitro (385% increase), and the antioxidant, NAC, ameliorated PA-induced hepatocyte activation. Furthermore, silencing of CD36 in vitro markedly attenuated PA-induced oxidative stress (H2O2: 41% decrease; ROS: 39% decrease), and the anti-activation effects of CD36 knockdown could be abolished by pretreatment with H2O2. CONCLUSIONS: Our study demonstrated that LCFA facilitates hepatocyte activation by up-regulating oxidative stress through CD36, which could be an important mechanism in the development of hepatic fibrosis.

A Case Study of Upper-Room UVGI in Densely-Occupied Elementary Classrooms by Real-Time Fluorescent Bioaerosol Measurements.

Recently, the requirement to continuously collect bioaerosol samples using shorter response times has called for the use of real-time detection. The decreased cost of this technology makes it available for a wider application than military use, and makes it accessible to pharmaceutical and academic research. In this case study, real-time bioaerosol monitors (RBMs) were applied in elementary school classrooms-a densely occupied environment-along with upper-room ultraviolet germicidal irradiation (UVGI) devices. The classrooms were separated into a UVGI group and a non-UVGI control group. Fluorescent bioaerosol counts (FBCs) were monitored on 20 visiting days over a four-month period. The classroom with upper-room UVGI showed significantly lower concentrations of fine size (<3 µm) and total FBCs than the control classroom during 13 of the 20 visiting days. The results of the study indicate that the upper-room UVGI could be effective in reducing FBCs in the school environment, and RBMs may be applicable in reflecting the transient conditions of the classrooms due to the dynamic activity levels of the students and teachers.

Evaluation of ultraviolet germicidal irradiation in reducing the airborne cultural bacteria concentrations in an elementary school in the Midwestern United States.

This article describes a casestudythe authors conducted in an elementary school in the Midwest. The objective was to evaluate the performance of ultraviolet germicidal irradiation (UGVI) to reduce the bioaerosol concentration in a classroom. Two fourth grade classrooms with the same dimensions were studied. One classroom was designated as the UVGI group and the other as the control group. Two-stage Tisch culturable impactors were utilized for collecting airborne bacteria with monthly samples collected from October 2012 to January 2013. Nonparametric methods were applied and p-values smaller than .05 were deemed significant. The concentrations of airborne cultural bacteria with a smaller size (1-8 pm) and the total bacterial concentrations from the UVGI classroom were significantly lower than those of the control room in three of four sampling months. These results could provide the preliminary results necessary to determine the effectiveness of upper-room UVGI in reducing the concentration of airborne cultural bacteria in classrooms and other buildings.

Sparsely corrupted stimulated scattering signals recovery by iterative reweighted continuous basis pursuit.

In this paper, we consider the problem of extracting the desired signals from noisy measurements. This is a classical problem of signal recovery which is of paramount importance in inertial confinement fusion. To accomplish this task, we develop a tractable algorithm based on continuous basis pursuit and reweighted [script-l]1-minimization. By modeling the observed signals as superposition of scale time-shifted copies of theoretical waveform, structured noise, and unstructured noise on a finite time interval, a sparse optimization problem is obtained. We propose to solve this problem through an iterative procedure that alternates between convex optimization to estimate the amplitude, and local optimization to estimate the dictionary. The performance of the method was evaluated both numerically and experimentally. Numerically, we recovered theoretical signals embedded in increasing amounts of unstructured noise and compared the results with those obtained through popular denoising methods. We also applied the proposed method to a set of actual experimental data acquired from the Shenguang-II laser whose energy was below the detector noise-equivalent energy. Both simulation and experiments show that the proposed method improves the signal recovery performance and extends the dynamic detection range of detectors.