Perfluoroalkyl substances exposure and the risk of breast cancer: A nested case-control study in Jinchang Cohort.

BACKGROUND: As persistent organic pollutants (POPs), perfluoroalkyl substances (PFAS) may potentially impact human health. Our study aimed to investigate the prospective association between PFAS exposure and the incidence risk of breast cancer in females. METHODS: By fully following the Jinchang Cohort after a decade, we conducted this nested case-control study with 135 incidence cases of breast cancer (BC) and 540 bias-paired controls. The PFAS levels were tested by baseline serum samples. Conditional logistic regression and a restricted cubic spline model were employed to investigate the BC incidence risks and the dose-response associated with single PFAS component exposure. Furthermore, the Quantile g-computation model (Qgc), random forest model (RFM), and bayesian kernel machine regression models (BKMR) were integrated to estimate the mixed effects of PFAS exposure on the incidence risk of BC. RESULTS: Exposures to specific PFAS components were positively associated with an increased incidence risk of breast cancer. By grouping the study population into different baseline menopausal statuses, PFHxS, PFNA, PFBA, PFUdA, PFOS, and PFDA demonstrated a similarly positive correlation with BC incidence risks. However, the increased incidence risks of BC associated with PFOA, PFOS, PFUdA, and 9CL-PF3ONS exposure were exclusively found in the premenopausal population. Both BKMR and Qgc revealed that exposure to mixed PFAS was associated with an increased risk of breast cancer, with Qgc specifically indicating an odds ratio (OR) of 2.21 (95% CI: 1.53, 3.19). Random forests showed that PFBA, PFOS, PFHxS, and PFDA emerged as predominant factors potentially influencing breast cancer incidence. CONCLUSION: Our findings suggest a strong association between PFAS exposure and the incidence of breast cancer. Premenopausal women should exercise more caution regarding PFAS exposure.

Seed soaking with melatonin promotes seed germination under chromium stress via enhancing reserve mobilization and antioxidant metabolism in wheat.

Chromium (Cr) pollution has serious harm to crop growth, while little is known on the role of melatonin (MT) on seed germination and physiology in Cr-stressed wheat. The effects of seed soaking with MT on growth, reserve mobilization, osmotic regulation and antioxidant capacity of wheat seeds during germination under hexavalent chromium (100 µM) stress were investigated. The results indicated that Cr toxicity decreased the seed germination rate by 16% and suppressed the growth of germinated seeds compared to unstressed seeds. MT in the concentration-dependent manner increased germination rate and promoted subsequent growth when seeds were exposed to Cr stress, but the effect could be counteracted at high concentration. Seed soaking with MT (100 µM) markedly decreased Cr accumulation in seeds, radicals and coleoptiles by 15%, 6% and 15%, respectively, and enhanced α-amylase activity and soluble sugar and free amino acids content in seeds to improve reserve mobilization under Cr stress, compared with Cr treatment. Furthermore, decreasing the level of osmotic regulators (soluble sugar and soluble protein) in radicles under MT combined with Cr treatment confirmed the reduction of osmotic stress caused by Cr stress. Importantly, MT pretreatment reduced H2O2 content by 19% and O2·- release rate by 45% in radicles under Cr toxicity compared with Cr-stressed wheat, in terms of promoting scavenging ability and decreasing production ability, which was to upregulate the activities and encoding genes expression levels of superoxide dismutase (SOD), catalase (CAT), ascorbic acid peroxidase (APX) and peroxidase (POD) and to downregulate plasma membrane-bound NADPH oxidase (NOX) encoding genes (TaRbohD, TaRbohF) expression, respectively. In all, these results provided evidence that seed soaking with MT could be a potentially method to protect wheat seeds from Cr toxicity, which effectively ameliorated germination under Cr stress by enhancing reserve mobilization and antioxidant metabolism in wheat.

[Trend of atmosphreic PM_(2. 5) and their components in two districts of Lanzhou City from 2015 to 2019].

OBJECTIVE: To analyse the variation of the fine particulate matter(PM_(2. 5)) concentration and its chemical composition in two districts of Lanzhou City from 2015 to 2019. METHODS: From January 2015 to December 2019, two sampling points, namely residential district(Chengguan District) and industrial district(Xigu District) were selected in Lanzhou City, to collect PM_(2. 5) samples, and the mass concentrations, metals and metalloid elements, water-soluble ions and polycyclic aromatic hydrocarbons(PAHs) contents were determined. RESULTS: A total of 838 samples were collected in Chengguan District and Xigu District in Lanzhou City during 2015-2019, the average annual mass concentration and the daily average concentration of the PM_(2. 5) were decreasing year by year(P<0. 05). The higher metal content in PM_(2. 5) were Al, Pb, Mn and As during 2015-2019. Sb, Al, As, Cd, Cr, Pb, Mn and Tl element content were higher in 2015 and 2016 than in other years(P<0. 05), the average annual concentration of As were 7. 92 and 8. 63 ng/m~3 respectively, which exceeded the reference concentration limit of the ambient air quality standard. The average annual mass concentration of Cr from 2015 to 2019 was much higher than the annual average reference concentration limit of the ambient air quality standard. From 2015 to 2019, except for 2018, the highest average concentration of PAHs in atmospheric PM_(2. 5) in the two districts of Lanzhou City was Ant, B(b)F and I(cd)P mass concentration were highest in 2015, N(a)P, FI, Ace, Phe, Ant, Flu, Pyr, B(k)F and B(a)P mass concentration were highest in 2017, Acy, Chr and B(ghi)P mass concentration were highest in 2018(P<0. 05). From 2017 to 2018, the average annual content of B(a)P in the two districts of Lanzhou City were 1. 16 and 1. 11 ng/m~3, respectively, which exceeded the annual average concentration limit of the ambient air quality standard. The concentration of Cl~- in PM_(2. 5) in the two districts of Lanzhou City was decreasing year by year, the annual average concentrations of SO~2-_4, NO~-_3 and NH~+_4 from 2017 to 2019 showed a downward trend year by year. SO~2-_4, Cl~- of both districts were the highest in 2015, and NO~-_3, NH~+_4 were the highest in 2017(P<0. 05). CONCLUSION: The air quality of Lanzhou City has been improved obviously, but the pollution problem is still serious.

[The characteristics and change trends of air pollutants in Lanzhou City from 2014 to 2020].

OBJECTIVE: To study the distribution characteristics of atmospheric pollutants and their correlation with meteorological factors. METHODS: The PM_(2.5), PM_(10), NO_2, SO_2, O_(3-1 h), O_(3-8 h) and CO daily average concentration data from 2014 to 2020 were obtained from Lanzhou Environmental Protection Bureau. The interannual changes of pollutants, monthly changes, seasonal changes and trend of spatial distribution were analysed. Spearman correlation analysis was performed on the relationship among pollutants. RESULTS: The main pollutants exceeding the standard in Lanzhou from 2014 to 2020 were PM_(10), PM_(2.5) and NO_2, average annual concentration of PM_(10), PM_(2.5), NO_2 and CO were decreasing year by year, and O_3 was increasing year by year. The monthly average concentration of PM_(10) was the highest in December, January, March and November were the second highest, and it was higher in February, April and May. The monthly change trends of PM_(2.5), NO_2, SO_2 and CO concentrations were the same, and the monthly change trends of the 1 hour average and daily maximum 8-hour average concentrations of O_3 were the same. The seasonal variation of atmospheric pollutant concentration was obvious, the concentrations of PM_(10), PM_(2.5), SO_2, NO_(2 )and CO were the highest in winter and the lowest in summer. O_3 concentration was the highest in summer and lowest in winter. Average annual concentration of 6 pollutants in different regions had statistically significant differences(H=750.40, 1112.99, 1410.05, 352.04, 360.17, 619.20, 729.52; P<0.001). Among them, the average annual concentration of PM_(10), PM_(2.5), SO_(2 )and O_(3-1 h) in Xigu District were the highest. PM_(10), PM_(2.5), NO_2, SO_2, CO average annual concentration were negatively correlated with temperature and wind speed(r_s=-0.423, -0.561, -0.395, -0.660, -0.569, -0.043, -0.094, -0.130, -0.172, -0.135), the concentration of PM_(10), PM_(2.5), O_3, SO_2 concentration were negatively correlated with humidity(r_s=-0.238, -0.121, -0.110, -0.094), only O_3 was positively correlated with temperature(r_s=0.486). CONCLUSION: The primary pollutants in Lanzhou from 2014 to 2020 were PM_(10), PM_(2.5) and NO_2.O_3 had an obvious upward trend year by year. The 6 pollutants had obvious seasonal changes and regional distribution characteristics. Some pollutants had the same homology, and meteorological factors affected each pollution. The concentration of the substance had an important influence. Relevant air pollution control measures should be formulated based on the main excessive pollutants, the monthly change trend of air pollution and the seasonal pollution characteristics, the same emission sources and geographical distribution characteristics should be considered, and the meteorological factors should be combined.

[Concentration changes of ten metal and metalloid elements in atmospheric PM_(2. 5) in two districts of Lanzhou City from 2015 to 2018].

OBJECTIVE: To detect the concentrations of ten metals and metalloid elements in the atmospheric PM_(2. 5) in Chengguan district and Xigu district of Lanzhou City from 2015 to 2018, and analyze the pollutant concentration and its change trend. METHODS: From 2015 to 2018, 662 samples of PM_(2. 5) were collected from Chengguan district and Xigu district of Lanzhou City. The concentrations of 10 kinds of metals and metalloid elements such as lead(Pb), arsenic(As), mercury(Hg), cadmium(Cd), chromium(Cr), antimony(Sb), manganese(Mn), nickel(Ni), selenium(Se), beryllium(Be) were detected, and the change trends of different monitoring points, years, seasons and months were analyzed. RESULTS: There was a significant difference in lead content between Chengguan District and Xigu District(χ~2=4. 80, P<0. 05), the median of Pb content in Chengguan and Xigu District was 45. 30 and 37. 20 ng/m~3, which was higher than that in Xigu District; the difference of Mn content in the two districts was statistically significant(χ~2=21. 28, P<0. 05), the median in two District was 32. 04 and 23. 37 ng/m~3, which was higher than that in Xigu District; the median of Be content in the two districts was statistically significant(χ~2=11. 57, P<0. 05), and the median of Be content in two districts was 0. 05 and 0. 07 ng/m~3, Xigu Distric was higher than Chengguan, there was no significant difference in other seven elements(P>0. 05). From 2015 to 2018, the element content of PM_(2. 5) in Chengguan District decreased by 47. 66% compared with 2015; Xigu District in 2018 decreased by 43. 79% compared with 2015; the higher element Pb, Mn and As in Chengguan District decreased by 52. 93%, 47. 00% and 49. 37% compared with 2015; in Xigu District, the content in 2018 decreased by 46. 87%, 47. 49% and 41. 98%compared with 2015, the contents of the remaining seven elements decreased in 2018 compared with those in 2015. There was no statistical significance(P>0. 05) in different seasons except for the difference of Ni content(P<0. 05), and the content of other elements showed a significant seasonal change: winter>spring>autumn> summer. The trend of monthly concentration change in the two regions was basically the same, the concentrations of Sb, As, Pb, Mn, Cd, Ni, Se, Hg and Cr were higher in November and February of next year. In Chengguan District and Xigu District, Ni content was higher in July and August, respectively;and Hg in Xigu District was higher in June, and Be was higher in less months, especially in February, October and December. CONCLUSION: From 2015 to 2018, the levels of 10 metals and metalloids element pollutants in PM_(2. 5) samples from Chengguan District and Xigu District of Lanzhou City showed a decreasing trend year by year, and had obvious seasonal changes.

Enhanced Rubisco activation associated with maintenance of electron transport alleviates inhibition of photosynthesis under low nitrogen conditions in winter wheat seedlings.

Studying the response of photosynthesis to low nitrogen (N) and the underlying physiological mechanism can provide a theoretical basis for breeding N-efficient cultivars and optimizing N management. We conducted hydroponic experiments using two wheat (Triticum aestivum) cultivars, Zaoyangmai (low N sensitive) and Yangmai158 (low N tolerant), with either 0.25 mM N as a low N (LN) treatment or 5 mM N as a control. Under LN, a decrease in net photosynthetic rate (Pn) was attributed to reduction in the maximum Rubisco carboxylation rate, which then accelerated a reduction in the maximum ribulose-1,5-bisphosphate regeneration rate, and the reduction in Pn was 5-35% less in Yangmai158 than in Zaoyangmai. Yangmai158 maintained a 10-25% higher Rubisco concentration, especially in the upper leaves, and up-regulated Rubisco activase activity compared with Zaoyangmai to increase the Rubisco activation to sustain Rubisco carboxylation under LN conditions. In addition, Yangmai158 increased electron flux to the photorespiratory carbon oxidation cycle and alternative electron flux to maintain a faster electron transport rate and avoid photodamage. In conclusion, the LN-tolerant cultivar showed enhanced Rubisco activation and sustained electron transport to maintain a greater photosynthetic capacity under LN conditions.

Estimating the burden of acute gastrointestinal illness in the community in Gansu Province, northwest China, 2012-2013.

BACKGROUND: Acute gastrointestinal illness (AGI) imposes considerable social and economic burden on low and middle-income countries. This study aimed to estimate the occurrence, distribution, and burden of self-reported AGI in Gansu Province of northwest China, where economic growth rates have lagged far behind those of other regions in China and systematic studies to investigate the burden of AGI are still lacking. METHODS: Twelve-month, retrospective face-to-face surveys were conducted in three sentinel sites between June 2012 and May 2013. Respondents were asked if they had experienced diarrhoea or vomiting in the 28 days prior to the interview. RESULTS: In total, 2094 interviews were completed. The adjusted monthly prevalence was 8.5% with an incidence rate of 1.16 episodes of AGI per person-year. Healthcare was sought by 73.8% of those reporting illness. Of the cases who visited a doctor, 50.5% submitted a stool sample. The use of antibiotics was reported by 65.6% of the cases and 53.3% took antidiarrhoeals. In the multivariable model, age, household income and sentinel site were significant risk factors of being a case of AGI. CONCLUSIONS: The burden of AGI was considerable in Gansu Province of northwest China. Ongoing research to identify the main causes of AGI is needed for more accurate estimate of the burden of AGI in this region.

Pesticide residues in vegetables from Gansu province, China and risk assessment by Monte Carlo simulation.

To assess the dietary exposure risks of pesticide residues in vegetables for the general population, the presence of 39 pesticides was determined in 70 samples, of which 13 were detected. The most frequently detected pesticide was bifenthrin, with a detection rate of 35.7%, mainly found in gingers, followed by isoprocarb and acephate (11.4%) and dimethoate (8.6%). In 17.1% of the samples two or more pesticide residues were found. Acute, chronic and chronic cumulative dietary exposure risk was assessed. Chronic exposure risks were determined by Monte Carlo Simulation (MCS). Estimated chronic exposure to carbofuran, omethoate, disulfoton and dimethoate of approximately 49%, 52%, 40% and 3%, respectively, were at non-carcinogenic human risk. Acute exposure risk to acephate was considered to be of concern due to the high acute hazard quotient (aHQ).

Health-risk assessment of mercury in main market-sold foods in the Pingliang region of Gansu province, China, from 2013 to 2021.

In the present study, we analyzed mercury concentrations in 742 samples across five main food categories from 2013 to 2021 using direct mercury analysis (DMA) to understand mercury pollution in major market-sold foods in the Pingliang region of Gansu Province and assess the health risks of mercury dietary exposure in adults. Health risks of adult dietary exposure were assessed through deterministic evaluation. Total mercury content ranged from non-detectable (ND) to 0.13 mg/kg, with a detection rate of 90.70% (673/742), the highest detection rates being in fresh edible mushrooms and nuts. The overall exceedance rate was 0.13% (1/742), with one sample of fresh edible mushrooms exceeding the regulatory limit for total mercury content. Additionally, we incorporated the average mercury content and consumption levels of meat and seafood from regions geographically close to Pingliang, as reported in the Fifth National Total Diet Study, to calculate the Estimated Daily Intake (EDI) by a deterministic evaluation. For adult males, the exposure was 0.120 µg/(kg BW), while for adult females, it was 0.141 µg/(kg BW). Both values are significantly lower than the provisional tolerable weekly intake (PTWI) of 4 µg/(kg BW) established by JECFA in 2010, indicating that the total mercury concentration from food intake does not pose a significant health risk to the residents of the Pingliang area. These findings offer valuable scientific data to inform food safety regulations in the region and can serve as a benchmark for future mercury pollution risk assessments in other locations.

Mycotoxins in grains (products), Gansu province, China and risk assessment.

This study aimed to estimate the dietary exposure towards mycotoxins of residents in Gansu province, China, from 2014-2020 through surveillance data on mycotoxins in grains and grain products. Fumonisin B1 (FB1), Deoxynivalenol (DON), 3- and 15-Acetyl-deoxynivalenol (3-ADON and 15-ADON), Tentoxin (TEN), Tenuazonic acid (TeA) and Zearalenone (ZEN) in 863 grains and grain products were detected by HPLC-MS and UPLC-MS. DON was the most detected mycotoxin of all samples. For women, the average dietary exposure to DON was 1.49 µg/kg bw/day, with 55.8% of the individuals eating dried noodles exceeding tolerable daily intake. The hazard quotient values were 1.24-12.60, so greater than 1 for DON at the average, 90th percentile, 95th percentile, and maximum levels: 44.6% of the HQ values for men and 45.7% for women were greater than 1.

Aflatoxins in dried chilli products in Gansu Province and health risk.

In order to understand the status of aflatoxin contamination in dried chilli products in Gansu Province and the risk of dietary exposure, a total of 106 samples of dried chilli products from farmers' markets and supermarkets in 14 prefecture-cities of Gansu Province were collected and analysed by isotope dilution liquid chromatography-tandem mass spectrometry. The results showed that the detection rate of aflatoxin in dried chilli products in Gansu Province was 30.2%, and the average level was 1.57 µg/kg. The detection rates of dried chillies, paprika, and chilli powders were 16.7%, 43.6%, and 46.2%, respectively. The detection rates of aflatoxin in dried chilli products from shops and farmers' markets were 22.5% and 40.0%, respectively. The dietary exposure of AFB1 was 0.0001 µg/kg bw/day, and the MOE calculated from its average concentration was 305.

Association between Exposure to Volatile Organic Compounds and the Prevalence of Sleep Problems in US Adults.

BACKGROUND: While mounting evidence suggests a connection between environmental contaminants and sleep problems, it remains uncertain whether exposure to volatile organic compounds (VOCs) specifically is associated with such problems. METHODS: Data from the National Health and Nutrition Examination Survey program's five survey cycles (2005-2006, 2011-2018) were used to conduct cross-sectional research. Data on short sleep duration (SSD) and self-reported trouble sleeping were collected from questionnaire data. Data on urine VOCs were gathered from laboratory data. The association between urinary VOCs and sleep problems was examined using weighted generalized linear models and the restricted cubic spline (RCS), weighted quantile sum (WQS), and quantile-based g-calculation (QGC) methods. RESULTS: In all, a total of 4131 general adult individuals were included in this study. The prevalence of SSD and self-reported trouble sleeping was 34.11% and 25.03%, respectively. 3,4-MHA, AAMA, AMCC, SBMA, and MA were risk factors for SSD after adjusting several covariates, with the largest effect being AMCC (OR = 1.47, 95% CI: 1.08, 2.02). Risk factors for sleep issues included AAMA, AMCC, CEMA, CYMA, DGBMA, 2HPMA, 3HPMA, MA, and PGA, with AMCC having the highest impact with an OR of 1.69 (95% CI: 1.28, 2.22). Both the WQS model and the QGC model showed that the co-exposure to VOCs was positively associated with SSD and self-reported trouble sleeping, with AMCC being the most influential VOC. CONCLUSIONS: According to our research, high levels of single or mixed urine VOCs are linked to a higher prevalence of SSD and self-reported trouble sleeping in the general adult population of the United States. Further prospective and experimental studies are needed in the future to validate these potential relationships and explore the underlying mechanisms.

Association between per- and poly-fluoroalkyl substances and nonalcoholic fatty liver disease: A nested case-control study in northwest China.

Per- and poly-fluoroalkyl substances (PFAS) have been reported to have hepatotoxic effects. However, it is unclear whether they are linked to non-alcoholic fatty liver disease (NAFLD). This nested case-control study focused on the epidemiological links between PFAS and the prevalence of NAFLD. We selected 476 new cases of NAFLD and 952 age- and sex-matched controls from the Jinchang cohort population between 2014 and 2019. Serum concentrations of PFAS were measured using high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). Only PFAS with a detection rate of ≥90 % were included for analysis, which included PFPeA, PFOA, PFNA, PFHxS, PFOS, and 9Cl-PF3ONS. The relationship between single and co-exposure to PFAS and the occurrence of NAFLD was evaluated using conditional logistic regression, Quantile g-computation (QgC), and Bayesian kernel machine regression (BKMR) model. Logistic regression indicated that PFPeA, PFOA, and 9Cl-PF3ONS were positive correlation with the incidence of NAFLD after adjusting for confounders, with odds ratios (OR) and 95 % confidence interval (CI) of 3.13 (95 % CI: 2.53, 3.86), 1.39 (95 % CI: 1.12, 1.73), and 1.41 (95 % CI: 1.20, 1.66), respectively. PFNA, PFHxS, and PFOS were nonlinearly and negatively associated with the incidence of NAFLD, with OR (95 % CI) of 0.53 (0.46, 0.62), 0.83 (0.73, 0.95), and 0.52 (0.44, 0.61), respectively. QgC showed a significant joint effect of PFAS mixture on NAFLD onset (OR: 1.52, 95 % CI: 1.24, 1.88). BKMR showed a weak positive trend between PFAS mixtures and NAFLD incidence. Positive correlations were primarily driven by PFPeA and 9Cl-PF3ONS, while negative correlations were mainly influenced by PFNA and PFOS. The BKMR model also suggested that there was an interaction between PFOS and PFNA and other four PFAS compounds. In conclusion, our findings suggest that individual and co-exposure to PFAS is associated with a risk of NAFLD onset.

Contribution of cell walls, nonprotein thiols, and organic acids to cadmium resistance in two cabbage varieties.

To study possible cadmium (Cd) resistance mechanisms in cabbage (Brassica oleracea L.), several parameters of metal uptake, distribution, and complexation were compared between two varieties Chunfeng [CF (Cd-tolerant)] and Lvfeng [LF (Cd-sensitive)]. Results showed that CF contained significantly lower Cd concentrations in leaves and higher Cd concentrations in roots than LF. Approximately 70 to 74 % and 66 to 68 % of Cd taken up by LF and CF, respectively, was transported to shoots. More Cd was bound to the cell walls of leaves, stems, and roots in CF than in LF. The higher capacity of CF to limit Cd uptake into shoots could be explained by immobilization of Cd in root cell walls. Compared with control groups, Cd treatment also significantly increased concentrations of nonprotein thiols, phytochelatins (PCs), and citric acid in the leaves and roots of the two varieties; the increases were more pronounced in CF than in LF. Taken together, the results suggest that the greater Cd resistance in CF than in LF may be attributable to the greater capacity of CF to limit Cd uptake into shoots and complex Cd in cell walls and metal binding ligands, such as PCs and citric acid. However, the contributions of PCs and citric acid to Cd detoxification might be smaller than those in cell walls.

Progress of new-onset diabetes after liver and kidney transplantation.

Organ transplantation is currently the most effective treatment for end-stage organ failure. Post transplantation diabetes mellitus (PTDM) is a severe complication after organ transplantation that seriously affects the short-term and long-term survival of recipients. However, PTDM is often overlooked or poorly managed in its early stage. This article provides an overview of the incidence, and pathogenesis of and risk factors for PTDM, aiming to gain a deeper understanding of PTDM and improve the quality of life of recipients.

The Interactive Effects between Drought and Air Pollutants on Children's Upper Respiratory Tract Infection: A Time-Series Analysis in Gansu, China.

As a destructive and economic disaster in the world, drought shows an increasing trend under the continuous global climate change and adverse health effects have been reported. The interactive effects between drought and air pollutants, which may also be harmful to respiratory systems, remain to be discussed. We built the generalized additive model (GAM) and distributed lag nonlinear model (DLNM) to estimate the effects of drought and air pollutants on daily upper respiratory infections (URTI) outpatient visits among children under 6 in three cities of Gansu province. The Standardized Precipitation Index (SPI) based on monthly precipitation (SPI-1) was used as an indicator of drought. A non-stratified model was established to explore the interaction effect of SPI-1 and air pollutants. We illustrated the number of daily pediatric URTI outpatient visits increased with the decrease in SPI-1. The interactive effects between air pollutants and the number of daily pediatric URTIs were significant. According to the non-stratified model, we revealed highly polluted and drought environments had the most significant impact on URTI in children. The occurrence of drought and air pollutants increased URTI in children and exhibited a significant interactive effect.

Melatonin alleviates chromium toxicity by altering chromium subcellular distribution and enhancing antioxidant metabolism in wheat seedlings.

The endogenous stimulating molecule melatonin (N-acetyl-5-methoxytryptamine, MT) has an important function in mitigating the impact of multiple abiotic stressors. However, the ameliorating effect of MT on chromium (Cr) stress and its mechanisms remains unclear. Therefore, the present study aimed to clarify the mitigating effect of exogenous MT (0 µM and 100 µM) on wheat seedlings under Cr (0 µM and 50 µM) stress stemming from the growth and physiological characteristics, phytochelatin (PC) biosynthesis, Cr subcellular distribution, and antioxidant system of the plants in these treatments. The results showed that endogenous MT application significantly promoted plant growth and improved root morphology of wheat seedlings under Cr stress due to decreased Cr and reactive oxygen species (ROS) accumulation in both roots and leaves. Accumulation and transport of Cr from roots to leaves were reduced by MT, because enhanced vacuolar sequestration via upregulated PC accumulation, took place, derived from the fact that MT upregulated the expression of key genes for PC synthesis (TaPCS and Taγ-ECS). Furthermore, MT pre-treatment alleviated Cr-induced oxidative damage by diminishing lipid peroxidation and cell apoptosis, profiting from the enhanced scavenging ability of ROS as a result of the MT-induced increase in the activities of superoxide dismutase, catalase, ascorbate peroxidase, and glutathione reductase, and the related encoding gene expression levels of TaSOD2, TaCAT, TaAPX, and TaGR. In conclusion, endogenous MT application improved the growth traits, antioxidant system, and decreased Cr accumulation especially at the leaf level in wheat seedlings under Cr stress mainly through enhancing antioxidant enzyme activities and altering Cr subcellular distribution via strengthening PC biosynthesis. The mechanisms of MT-induced plant tolerance to Cr stress could help develop new strategies for secure crop production in Cr-polluted soils.

First total synthesis of a naturally occurring iodinated 5'-deoxyxylofuranosyl marine nucleoside.

4-Amino-7-(5'-deoxy-ß-D-xylofuranosyl)-5-iodo-pyrrolo[2,3-d]pyrimidine 1, an unusual naturally occurring marine nucleoside isolated from an ascidan, Diplosoma sp., was synthesized from D-xylose in seven steps with 28% overall yield on 10 g scale. The key step was Vorbrüggen glycosylation of 5-iodo-pyrrolo[2,3-d]pyrimidine with 5-deoxy-1,2-O-diacetyl-3-O-benzoyl-D-xylofuranose. Its absolute configuration was confirmed.

The Association of Paraoxonase-1 Polymorphism with Carotid Artery Stenosis among Elderly Chinese Population.

Elderly population is in high risk of carotid atherosclerosis and artery stenosis (CAS). It has been proved that PON1 polymorphism is associated with low-density lipoprotein (LDL) oxidation, which plays an important role in artery atherosclerosis. CAS is an important cause of ischemic stroke. This study is aimed at investigating the association of PON1 (rs662) polymorphism with the risk of CAS among elderly Chinese population. Consecutive elderly patients with CAS were enrolled into the study. Genotyping for PON1 (rs662) polymorphism was performed on all participants. There were 310 CAS patients in this study, with 88 symptomatic CAS and 222 asymptomatic CAS. G allele had a frequency of 59.66% in symptomatic CAS (sCAS); and A allele had an incidence of 36.93% in asymptomatic CAS (aCAS) (P < 0.05). In all CAS patients with and without symptom, no associations were found in any genotype comparison. However, among aCAS subjects, based on GA phenotype, the odds ratio (OR) of the mutant GG with stenosis severity was 0.20 (P = 0.01). The OR of GG+GA mutation was 0.28 for moderate/severe severity, compared with GA type (P = 0.03). This study indicates that PON1 (rs662) polymorphism is not associated with the presence of symptom among CAS patients. Moreover, PON1 (rs662) polymorphism correlates with stenosis severity among aCAS.

Short-term effects of particulate matter exposure on emergency room visits for cardiovascular disease in Lanzhou, China: a time series analysis.

Cardiovascular disease (CVD) has been the leading cause of death in China. Identifying the relationship between particulate matter (PM) and CVD in China is a significant challenge. In this study, daily CVD emergency room visit, environmental monitoring, and weather data from January 1, 2017, to December 31, 2018, in Lanzhou were collected. Generalized additive models (GAMs) were constructed to estimate the short-term effects of daily PM2.5, PMC, and PM10 concentrations on CVD emergency room visits with different lag structures after controlling for the influence of meteorological elements and gaseous pollutants. Stratified analyses were conducted according to age (≥ 65 years and < 65 years), sex (male and female), cold season (from November to April), and warm season (from May to October). The results showed that each 10 µg/m3 increase in PM2.5 was associated with a 1.93% (95% CI 0.12-3.78%) increase in CVD emergency room visits at lag03, and no single lag model was statistically significant. The excess relative risks (ERRs) of PM10 and PMC were not statistically significant at any lag pattern. The exposure-response curves demonstrated a nonlinear upward trend for these three PM pollutants. When adjusting for other gaseous pollutants, such as NO2, SO2, CO, and O3, in the two-pollutant models, the associations between PM10 and PMC and CVD emergency room visits did not change compared with the single-pollutant models. The ERRs of PM2.5 were 1.67% (95% CI 0.03-3.34%) at lag02 after adjustment for NO2 and 1.65% (95% CI 0.02-3.30%) at lag02 after adjustment for SO2. The ERRs of PM2.5 were still statistically significant at lag03 when we adjusted for any one of the gaseous pollutants. Susceptibility to PM2.5 was increased in people aged < 65 years, in males, and in the warm season. The findings are very important for local governments to develop environmental policies and strategies to reduce ambient PM2.5 levels.