24-h Concentrations Research Articles

Effects Of 12-weeks Of Post-meal Walking On Glycemic Control And Body Composition In Older Adults

There is strong evidence that short bouts of light-intensity post-meal exercise are effective at lowering post-prandial and 24-h glucose concentrations in older people with impaired glucose tolerance (IGT). It is unknown, however, whether these transient benefits result in more enduring improvements in glycemic control after training. PURPOSE: To determine the effects of a home-based, 12-week post-meal walking program on improvements in glucose metabolism, as well as on changes in body composition in overweight (BMI=30±1.8 kg/m2) older adults (N=6; 72±5.3 years) with IGT. METHODS: Participants performed three 15-minute bouts of low-intensity (3 METs) walking beginning 30 minutes after each meal on five days per week for 12 weeks. Glucose and insulin responses to an oral glucose tolerance test were determined 48 h after the last exercise bout before and after training. Changes in body composition were determined using iDXA. RESULTS: Overall adherence to the total training program (180 post-meal walking bouts) was 65%; however, participants reported completing an average of 82% of the post-dinner walks across the 12 weeks. Total areas under the curve for both glucose [29.5±9.3 vs. 29.5±8.9 (mg·dL-1)·3h·103] and insulin [9.2±5.4 vs. 9.0±4.4 (mg·dL-1)·3h·103] responses did not change between baseline and follow-up; however, HbA1c levels (6.45% vs.5.86%) and the Whole Body Insulin Sensitivity Index (4.5± 3.6 vs. 5.8 ± 8.7) showed promising improvements following training. There were no changes to body weight, body fat, or lean mass; however, visceral fat volume decreased (688.7±311.4 vs. 584.3±306.0 cm3), and four of the six participants reduced their visceral fat mass by over 37g. CONCLUSIONS: Data from this pilot study suggest that the benefits of regular, low-intensity post-meal walking on glycemic control may not last beyond 24h in older adults with IGT. On the other hand, if performed consistently over time, the transient benefits may result in more enduring improvements in HbA1c and particularly in visceral fat mass. Supported by NIH/NIA R56 AG050661

Comparison of aggregated exposure to di(2-ethylhexyl) phthalate from diet and personal care products with urinary concentrations of metabolites using a PBPK model – Results from the Norwegian biomonitoring study in EuroMix

Phthalates are widely used as plasticisers in flexible plastics and containers for food and personal care products (PCPs) and contaminates foods and PCPs. A human biomonitoring (BM) study was performed to study exposure of chemicals from foods and PCPs. For two 24-h periods, adult volunteers (n = 144) in Norway kept diaries on food eaten and usage of PCPs, and collected 24-h urine. Aggregated exposure to di(2-ethylhexyl) phthalate (DEHP) from dietary and PCPs was estimated by Monte-Carlo simulation using Oracle Crystal Ball©. Simulated urinary concentrations using physiologically based pharmacokinetic (PBPK) models were compared with measured urinary metabolites of DEHP, mono-2-ethylhexyl phthalate (MEHP), mono-2-ethyl-5-hydroxyhexyl phthalate (MEHHP), mono-2-ethyl-5-oxohexyl phthalate (MEOHP) and mono-2-ethyl 5-carboxypentyl phthalate (MECCP). DEHP exposure from food are approximately 10 times higher than exposure than from PCPs. The main contributors to dietary exposure are dairy, grain, fruits and vegetables, meat and fish. Body lotion contribute most to the exposure of DEHP from PCPs. Forward-dosimetry gives good convergence with 24-h urinary concentrations of simulated and measured BM data. The measured concentration of the MECCP metabolite correlated well with simulated high exposure, while the measured concentrations of MEHP, MEHHP and MEOHP partly overlapped with both simulated low, medium and high metabolite exposure.

Cyanide Contamination of the Puyango-Tumbes River Caused by Artisanal Gold Mining in Portovelo-Zaruma, Ecuador.

To examine cyanide (CN-) contamination of a large river in southeastern Ecuador that has been severely impacted by the indiscriminate discharge of untreated gold processing effluents. Poor environmental stewardship of cyanide (CN-) use by 87 gold processing centers in Portovelo-Zaruma in southern Ecuador to leach residual gold from Hg-contaminated tailings has resulted in high CN- contamination of the Puyango-Tumbes River downstream from the centers. Free CN- concentrations were high in river surface waters for 50km below the processing plants, with the highest concentration 9088 times above the CCME standard of 5μg/L and 1136 times above the 24-h LC50 concentration of 40μg/L free CN- for some fish species. Due to cyanidation of mercury-contaminated tailings, the formation of Hg-CN complexes is a grave concern, as these complexes have been shown to be highly bioavailable. Preliminary tests conducted in a laboratory using bioassays with Danio rerio sp. and varying concentrations of synthetic Hg(CN)2 salt have shown significant THg bioaccumulation in muscle and kidney fish tissues exposed to concentrations >0.12mg/L. Furthermore, low MeHg results in fish tissues demonstrated little occurrence of methylation and that the bulk of the total mercury content was in the form of inorganic mercury. Although construction of a communal tailings facility (CTF) in Portovelo is a positive development to reduce riverine pollution, the requirement to truck tailings up to the CTF likely results in inadequate compliance of environmental regulations that are poorly enforced.

ABCG2 C421A polymorphisms affect exposure of the epidermal growth factor receptor inhibitor gefitinib.

ATP-binding castle protein G2 (ABCG2) is thought to inhibit the activities of certain gefitinib transporters, thereby affecting drug pharmacokinetics. The C421A polymorphism affects the function and expression of ABCG2 on the cell membrane. Previous studies have shown that proton-pump inhibitors (PPIs) inhibit gefitinib absorption, as well as the function of ABCG2. We evaluated the plasma concentrations of gefitinib in patients with and without the ABCG2 C421A polymorphism, who were or were not taking PPIs. In total, 61 patients with advanced epidermal-growth-factor-positive non-small-cell lung cancer were enrolled in this study. They were treated with gefitinib at a dose of 250mg per day. Plasma gefitinib concentration and ABCG2 C421A status were determined after 2weeks. The patients were divided into CC- and CA/AA genotype groups. We compared the trough and peak gefitinib levels and the area under the curve (AUC) values for 24-h gefitinib concentrations. We also compared these parameters among four groups distinguished according to the presence or absence of the polymorphism and PPI use. The mean trough gefitinib level and AUC value for 24-h gefitinib concentration were significantly lower in the CA/AA group compared to the CC group (mean trough level: 333.2 vs. 454.5ng/mL, respectively, P = 0.021; AUC: 9949.9 vs. 13,085.4ng・h/mL, respectively, P = 0.034). Among patients taking PPIs, the mean trough gefitinib level was significantly lower in the CA/AA group than the CC group (220.1 vs. 340.5ng/mL, respectively, P = 0.033). The CA/AA-type of ABCG2 C421A polymorphism may be associated with lower gefitinib plasma concentrations.

How do ultrafine particles in urban air affect ambulatory blood pressure?

Air in urban areas is usually contaminated with particle matter. High concentrations lead to a rise in the risk of cardiovascular and respiratory diseases. Some studies have reported that ultrafine particles (UFP) play a greater role in cardiovascular diseases than other particle matter, particularly regarding hypertensive crises and DBP, although in the latter such effects were described concerning clinical blood pressure (BP). In this study, we evaluate the relationship between 24-h ambulatory BP monitoring (ABPM) and atmospheric UFP concentrations in Barcelona. An observational study of individual patients' temporal and geographical characteristics attended in Primary Care Centres and Hypertensive Units during 2009-2014 was performed. The participants were 521 hypertensive patients, mean age 56.8 years (SD 14.5), 52.4% were women. Mean BMI was 28.0 kg/m and the most prominent cardiovascular risk factors were diabetes (N = 66, 12.7%) and smoking (N = 79, 15.2%). We describe UFP effects at short-term and up to 1 week (from lag 0 to 7). For every 10 000 particle/cm UFP increase measured at an urban background site, a corresponding statistically significant increase of 2.7 mmHg [95% confidence interval = (0.5-4.8)] in 24-h DBP with ABPM for the following day was observed (lag 1). We have observed that a rise in UFP concentrations during the day prior to ABPM is significantly associated with an increase in 24 h and diurnal DBP. It has been increasingly demonstrated that UFP play a key role in cardiovascular risk factors and, as we have demonstrated, in good BP control.

Concentration Variability of Water-Soluble Ions during the Acceptable and Exceeded Pollution in an Industrial Region.

This study investigates the chemical composition of water-soluble inorganic ions at eight localities situated in the Moravian–Silesian Region (the Czech Republic) at the border with Poland. Water-soluble inorganic ions were monitored in the winter period of 2018 (January, 11 days and February, 5 days). The set was divided into two periods: the acceptable period (the 24-h concentration of PM10 < 50 µg/m3) and the period with exceeded pollution (PM10 ˃ 50 µg/m3). Air quality in the Moravian–Silesian Region and Upper Silesia is among the most polluted in Europe, especially in the winter season when the concentration of PM10 is repeatedly exceeded. The information on the occurrence and behaviour of water-soluble inorganic ions in the air during the smog episodes in Europe is insufficient. The concentrations of water-soluble ions (chlorides, sulphates, nitrates, ammonium ions, potassium) during the exceeded period are higher by two to three times compared with the acceptable period. The major anions for both acceptable period and exceeded pollution are nitrates. During the period of exceeded pollution, percentages of water-soluble ions in PM10 decrease while percentages of carbonaceous matter and insoluble particles (fly ash) increase.

Individual species and cumulative mixture relationships of 24-hour urine metal concentrations with DNA methylation age variables in older men

BackgroundGlobally, toxic metal exposures are a well-recognized risk factor for many adverse health outcomes. DNA methylation-based measures of biological aging are predictive of disease, but have poorly understood relationships with metal exposures. ObjectiveWe performed a pilot study examining the relationships of 24-h urine metal concentrations with three novel DNA methylation-based measures of biological aging: DNAmAge, GrimAge, and PhenoAge. MethodsWe utilized a previously established urine panel of five common metals [arsenic (As), cadmium (Cd), lead (Pb), manganese (Mn), and mercury (Hg)] found in a subset of the elderly US Veterans Affairs Normative Aging Study cohort (N = 48). The measures of DNA methylation-based biological age were calculated using CpG sites on the Illumina HumanMethylation450 BeadChip. Bayesian Kernel Machine Regression (BKMR) was used to determine metals most important to the aging outcomes and the relationship of the cumulative metal mixture with the outcomes. Individual relationships of important metals with the biological aging outcomes were modeled using fully-adjusted linear models controlling for chronological age, renal function, and lifestyle/environmental factors. ResultsMn was selected as important to PhenoAge. A 1 ng/mL increase in urine Mn was associated with a 9.93-year increase in PhenoAge (95%CI: 1.24, 18.61, p = 0.03). The cumulative urine metal mixture was associated with increases in PhenoAge. Compared to a model where each metal in the mixture is set to its 50th percentile value, every one-unit increase of the cumulative mixture with each metal at its 70th percentile was associated with a 2.53-year increase in PhenoAge (95%CI: 0.10, 4.96, P<0.05). ConclusionOur results add novel evidence that metals detected in urine are associated with increases in biological aging and suggest that these DNA methylation-based measures may be useful for identifying individuals at-risk for diseases related to toxic metal exposures. Further research is necessary to confirm these findings more broadly.

Gold nanoparticles modulate the steroidogenic and apoptotic pathway in a buffalo granulosa cell model.

Granulosa cells are associated with steroidogenesis and ovarian function in females. Aims of the study are to understand the effects of gold nanoparticles (AuNP) on steroidogenesis and apoptotic pathway associated genes in buffalo granulosa cells. The AuNP were prepared chemically and thereby characterized by transmission electron microscope (TEM) imaging, absorbance and dynamic light scattering (DLS) measurements for hydrodynamic diameter and zeta potential. The cultured buffalo granulosa cells (BGC) were co-incubated with AuNP in two concentrations (2 × 109 and 2 × 1010 AuNP/ml) for 24h. Treatment of BGC with AuNP significantly modulated the steroidogenesis associated genes (3β-Hsd and Cyp19A1) expression and progesterone accumulation in the culture fluid. AuNP affected the apoptotic pathway in BGC by affecting the gene expression of Caspase-3, Bad and Bax. The AuNP did not exert oxidative stress through anti-oxidant induction & lipid peroxidation in the buffalo GC. AuNP may modulate the endocrine system by having impact on the steroidogenesis pathway and also have the potential to affect apoptotic pathway in a buffalo granulosa cell model.

DEVELOPMENT OF NANOEMULSION TO IMPROVE THE OCULAR BIOAVAILABILITY AND PATIENT COMPLIANCE IN POSTOPERATIVE TREATMENT USING INDOMETHACIN

Objective: To develop a new cationic nanoemulsion (NE) for ophthalmic delivery of indomethacin (IND) to improve the permeability and retention time of formulations, thereby improving the drug's ocular bioavailability.&#x0D; Methods: Based on the solubility profile of indomethacin in various solvents, captex 8000 was selected as oil phase, span 20 as a surfactant and tween 20 as co-surfactant to construct pseudo ternary phase diagrams and nanoemulsion region was recognized. Sonication was used as the method of NE preparation. Optimization was done using 32 factorial designs by considering the oil and the ratio of surfactant to co-surfactant (Smix) quantities as independent variables and evaluated for different physicochemical properties. Ex vivo transcorneal permeability was studied using bovine cornea, the In vivo drug pharmacokinetics of optimized NE and marketed formulation were assessed in rabbit aqueous humor and also in plasma.&#x0D; Results: The mean globule size, zeta potential, viscosity, refractive index, pH, surface tension and the osmolarity values for the prepared indomethacin nanoemulsions (IND-NEs) were found between 129.8±1.1 to 191.4±1.6 nm,+13.20±4.6 to+23.45±4.82, 15.3±0.1 to 32.7±0.0 mPas, 1.346±0.007 to 1.386±0.005, 5.5±0.4 to 6.9±0.9, 32.0±2.6 to 52.3±3.4 mN/m and 303-395 mOsm/l respectively and all these values found to be falling under the recommended values for ophthalmic use. From the In vitro release studies, it was found that the IND-NEs exhibited sustained drug release with 67.91±2.01 to 95.90±1.93 % drug release at 24h when compared to the drug solution which showed 99.81±5.21 % drug release within 2h. The Ex vivo drug permeation through the corneal membrane at 4h from the optimized NE and drug solution was found to be 524±1.5 µg/cm2 and 175±2.6 µg/cm2 respectively. Further, the optimized NE was found to be nonirritant with the lowest ocular irritation potential (Iirr) of 1 towards the rabbit's eyes. The area under the drug concentration vs. time curve for 24h (AUC (0–24h)) for optimized NE and the marketed formulation was found to be 1514.99 ng/ml/h and 974.14 ng/ml/h in aqueous humour; 2266.83 ng/ml/h and 778.15 ng/ml/h in plasma respectively.&#x0D; Conclusion: Due to its improved corneal absorption and prolonged drug release along with less systemic absorption, the optimized NE offers an effective postoperative treatment with increased ocular bioavailability and improved patient compliance with a decrease in the number of installations per day and a decrease or disappearance of systemic side effects of IND.

A factorial cluster-randomised controlled trial combining home-environmental and early child development interventions to improve child health and development: rationale, trial design and baseline findings

BackgroundExposure to unhealthy environments and inadequate child stimulation are main risk factors that affect children’s health and wellbeing in low- and middle-income countries. Interventions that simultaneously address several risk factors at the household level have great potential to reduce these negative effects. We present the design and baseline findings of a cluster-randomised controlled trial to evaluate the impact of an integrated home-environmental intervention package and an early child development programme to improve diarrhoea, acute respiratory infections and childhood developmental outcomes in children under 36 months of age living in resource-limited rural Andean Peru.MethodsWe collected baseline data on children’s developmental performance, health status and demography as well as microbial contamination in drinking water. In a sub-sample of households, we measured indoor kitchen 24-h air concentration levels of carbon monoxide (CO) and fine particulate matter (PM2.5) and CO for personal exposure.ResultsWe recruited and randomised 317 children from 40 community-clusters to four study arms. At baseline, all arms had similar health and demographic characteristics, and the developmental status of children was comparable between arms. The analysis revealed that more than 25% of mothers completed primary education, a large proportion of children were stunted and diarrhoea prevalence was above 18%. Fifty-two percent of drinking water samples tested positive for thermo-tolerant coliforms and the occurrence of E.coli was evenly distributed between arms. The mean levels of kitchen PM2.5 and CO concentrations were 213 μg/m3 and 4.8 ppm, respectively.ConclusionsThe trial arms are balanced with respect to most baseline characteristics, such as household air and water pollution, and child development. These results ensure the possible estimation of the trial effectiveness. This trial will yield valuable information for assessing synergic, rational and cost-effective benefits of the combination of home-based interventions.Trial RegistryISRCTN-26548981.

Novel insights into the fucose metabolism – challenging the old dogma

GDP‐Fucose used for glycan fucosylation is synthesized de novo from either glucose (Glc) or mannose (Man) or utilized directly from salvaged/exogenous fucose (Fuc). Meticulous radioisotope dilution studies performed in the 1970’s only in HeLa cells using 0.3 μM Fuc showed that the de novo pathway provides &gt;90% of GDP‐Fuc and salvage &lt;10%.Employing different Fuc‐specific lectins, we showed that at low concentrations (&lt;20 μM), the entry of Fuc into cells relies on transport via GLUT1 (SLC2A1), but above this, most Fuc enters via amiloride‐sensitive macropinocytosis. Inhibitors of both clathrin‐ and caveolin‐dependent endocytosis had no effect on uptake. These findings were further confirmed using 3H Fuc in four cell lines.We used differentially labelled 13C Glc, Man and Fuc to study contributions of each pathway to Fuc in N‐glycans in six cell lines. Very low concentrations (0.5–30 μM) of exogenous Fuc progressively inhibit the de novo pathway, and completely by ~50 μM. Surprisingly, GDP‐Fuc derived from Glc is much more sensitive to this inhibition than that derived from Man, even though both contribute to GDP‐Man synthesis. When cultured in 30–50 μM Fuc, cells not only inhibit the de novo pathway, but also prefer exogenous over salvaged Fuc. Cells seem to distinguish multiple pools of GDP‐Fuc based on their origin.Using LC‐MS/MS and eight different cell lines, we studied the ongoing biosynthesis of &gt;150 fucosylated N‐glycans containing 1–4 Fuc residues by comparing the proportion of 13C Fuc incorporation at various concentrations for 24h. Over the labeling period, cells had to choose between GDP‐Fuc synthesized de novo or from exogenous fucose. N‐glycans with a single Fuc show a proportional increase in 13C‐labeled species with increasing concentration of label. To our surprise, glycans with 2, 3, and 4 Fuc each required progressively higher exogenous 13C Fuc to become fully labeled.Based on LC‐MS/MS and lectin staining, 1–6αFuc labels more efficiently with exogenous Fuc than 1–2α, 1–3α and 1–4αFuc, suggesting differential access to exogenous sugar that depends partially on Fuc linkage. Km differences between fucosyltransferases cannot explain preferential use of GDP‐Fuc synthesized from exogenous monosaccharide over de novo produced substrate. Rather, it suggests the existence of separate, ill‐defined pools of GDP‐Fuc. Altogether it raises the question whether salvaged fucose equivalent to exogenous Fuc? Their behavior clearly differs from de novo synthesized GDP‐Fuc.Support or Funding InformationThe Rocket Fund and R01DK099551.

Turbidity effects of suspended bauxite in embryonic stage of climbing perch (Anabas testudineus) post fertilization

Runoff of bauxite residues had caused severe turbidity in two rivers water near Kuantan. Such river turbidity is a global threat to aquatic fauna like fish embryo. To investigate the turbidity effects of suspended bauxite on climbing perch (Anabas testudineus) embryo, the organism was exposed to bauxite after post-fertilisation. The 24-h median lethal concentration (24-h LC50), the lowest effect concentration (LOEC), and no-observed effect concentration (NOEC) were 4.212 g L−1, 2.190 g L−1, and 0.125 g L−1, respectively. Sublethal effects observed were hatching rate and unhatched rate, and mean hatching hours. The lethal effects clearly shown in bauxite levels of 6.00–24.00 g L−1. Fatal effects were observed in these treatment groups which resulted in a mortality above 80%. Among the deadly effects recorded were malformations, shrinking of yolk, bauxite coating, and ruptured chorion. Overall, our finding suggest that the level of bauxite residues in the water should not exceed 0.125 g L−1 to ensure good development and survival of A. testudineus embryos.

Survey of 24-h personal formaldehyde exposures in geographically distributed urban office workers in the USA.

An air sampling study was conducted to evaluate personal formaldehyde exposures in a group of office workers spread across five geographical locations in the USA. Passive badge samples for formaldehyde were collected on three participants in each location, as well as in the office and home indoor microenvironments of each participant over 3 individual days. Median personal 24-h formaldehyde concentrations ranged from 9.9 to 18μg/m3. Personal 24-h formaldehyde concentrations in one location were significantly higher than concentrations measured in the other four locations; no significant differences existed between any of the other locations. The participants in this study spent an average of 53% of their daily time in their homes, 36% at their office, and 11% in other indoor and outdoor locations. A comparison of measured 24-h personal formaldehyde concentrations and a model of average exposure based upon measured concentrations in the indoor microenvironments suggested that both the home and office formaldehyde concentrations were a strong predictor (R2 = 0.88) of overall personal exposure. The data from this study are representative of office workers in urban environments and can be used as background formaldehyde exposure levels (in the absence of specific sources) for both occupational and nonoccupational exposure assessments.

Pre- and postnatal heat stress abatement affects dairy calf thermoregulation and performance

Prenatal heat stress during late gestation exerts long-term effects on growth and productivity of the dairy calf. Further, direct exposure to heat stress during the preweaning period impairs calf thermoregulation and performance. We examined the effects of heat stress abatement during the prenatal period, postnatal period, or both on calf performance. We hypothesized that calves exposed to pre- and postnatal heat stress abatement would perform most optimally in terms of thermoregulation, growth, and health responses when compared with calves that are heat-stressed at any time in the pre- or postnatal periods. Holstein calves born to heat-stressed (HT) or cooled (CL) dams during late gestation (44 ± 5 d; prenatal HT or CL) were exposed to heat stress or cooling postnatally for 56 d (postnatal HT or CL), resulting in 4 treatments: HT-HT, HT-CL, CL-HT, and CL-CL; n = 12/treatment. Calves were administered 4 L of pooled colostrum and after 2 d of age allotted 10 L/d milk replacer and up to 3 kg/d concentrate in automatic feeder group pens (n = 6/pen). Postnatal cooling was achieved by 2 fans (average wind speed 2 m/s). Thermoregulatory responses (respiration rate and heart rate; rectal, body, and skin temperature), feed intake, growth parameters including average daily gain and medication events were recorded, and blood samples were collected weekly. Thermoregulatory responses were lower in postnatal CL calves compared with postnatal HT. In the afternoon, HT-HT calves had the highest respiration rate and rectal temperature, HT-CL calves had the lowest respiration rate, and CL-HT calves had the lowest heart rate compared with the other treatment groups. Prenatal CL calves weighed more at birth and weaning with a tendency for greater average daily gain compared with prenatal HT calves, whereas postnatal CL calves had increased milk replacer and concentrate intake and a tendency for reduced fever, infection, and total medication events relative to postnatal HT. Prenatal HT calves were esophageal tube fed more often than prenatal CL. Blood hematocrit and 24-h serum IgG concentration were greater in prenatal CL calves relative to prenatal HT. Prenatal heat stress abatement improves weight gain, hematocrit, and immunoglobulin transfer, whereas postnatal heat stress abatement modulates thermoregulatory responses, feed intake, and calf health. This study is the first to characterize the combined effects of pre- and postnatal heat stress or active cooling on the dairy calf.

Association of short-term exposure to sulfur dioxide and hospitalization for ischemic and hemorrhagic stroke in Guangzhou, China

BackgroundIn developing countries, ambient sulfur dioxide (SO2) is a serious air pollutant concern, but there is no enough and consistent epidemiological evidence about its health effects on stroke hospitalization.MethodsWe collected the daily air pollution data, meteorological data and number of daily hospital admissions for ischemic and hemorrhagic stroke, in Guangzhou from January 1st 2009 to December 31st 2014. Then we applied generalized additive model with a quasi-Poisson link to assess the relationship between short-term SO2 exposure and the total number of hospital admissions for ischemic and hemorrhagic stroke. In addition, we evaluated the effect of ambient SO2 by age (< 65 years and ≥ 65 years).ResultsDuring the study period, a 24-h mean concentration of ambient SO2 of 27.82 μg/m3, a total of 58,473 ischemic stroke and 9167 hemorrhagic stroke hospital admissions hospital were recorded. Ambient SO2 was found to increase the risk for both ischemic and hemorrhagic stroke hospital admission in single pollutant model. The maximum value of percentage changes for ischemic and hemorrhagic stroke occurred in lag 0 day and lag 1 day, per 10 μg/m3 increase in SO2 concentrations was corresponded to a 1.27% (95% confidence interval (CI), 0.42–2.12%) and 1.55% (95%CI, 0.02–3.11%) increased risk, respectively. The association between SO2 and ischemic stroke hospitalization was robust to two pollutant model, but for hemorrhagic stroke it’s partially weakened after adjusting for co-pollutants. The effect of ambient SO2 on ischemic stroke appeared to be greater for people < 65 years old, but null effect on hemorrhagic stroke was identified for both age groups.ConclusionsWe found short-term exposure to ambient SO2 may significantly increase the risks of hospitalization for ischemic stroke. The findings may contribute to a better understanding of the health effects of low-levels of SO2.

Variation of indoor and outdoor carbonaceous aerosols in rural homes with strong internal solid fuel combustion sources

Organic carbon (OC) and elemental carbon (EC) are important components of particulate matter and contribute significantly to the health and climate impacts of aerosols. In this study, we evaluated indoor and outdoor OC and EC concentrations in the total suspended particle (TSP) contents and their seasonal variations in rural households with strong indoor solid fuel combustion sources. The 24-h average indoor TSP, EC and OC concentrations were 470 ± 256, 7.9 ± 10.9, and 75 ± 114 μg/m3 during the non-heating period and increased to 691 ± 287, 19 ± 9, and 192 ± 97 μg/m3 during the heating period, respectively. The seasonal differences were statistically significant (p < 0.05). The increments in OC and EC concentrations were larger in outdoor air than in indoor air. OC and EC were correlated, with more significant correlations in indoor air compared to outdoor air and stronger correlations during the heating period compared to the non-heating period. In winter, the total carbon (TC=EC+OC) mass fractions in TSP increased obviously, primarily because of coal burning for indoor environments.

Alleviation of copper toxicity in Daphnia magna by hydrogen nanobubble water

As a novel antioxidant, hydrogen water has been widely used to alleviate oxidative stress in plants as well as in the medical field. However, the function of hydrogen water in environmental toxicology remains unknown. In this study, combining nanobubbles (NBs) and hydrogen water, we investigate the effect and mechanism of hydrogen NB water on copper induced acute toxicity to water fleas (Daphnia magna). The 24-h lethal Cu concentrations at which 50 % of the population die were 84 μg/L in hydrogen NB water and 45 μg/L in control water, confirming that hydrogen NB water effectively alleviated acute Cu toxicity in D. magna. The results were consistent with a significant reduction of Cu uptake and decrease of Cu accumulation in D. magna. As confirmed in fluorescence spectrophotometry and high-content screening system analysis, the hydrogen NB water also significantly reduced the oxidative damage and improved Cu tolerance in D. magna. From the results, it can be inferred that hydrogen NB water alleviates Cu stress in D. magna by depressing Cu bioaccumulation and reducing oxidative stress. The results provide basic data of hydrogen NB water for environmental toxicologists, and also a reference for the application of hydrogen NB water in the environment.

Free nitrous acid-based suppression of sulfide production in sewer sediments: In-situ effect mechanism.

Sulfide production control in gravity sewer sediments is more complex and difficult due to the greater spatial complexity of biological processes as a result of the abundant microflora inside the sediments. In this study, a promising and cost-effective free nitrous acid (FNA)-based suppression strategy for sulfide production in sewer sediments was proposed. Novel in-situ measurement methods were implemented by incorporating the diffusive gradients in thin films (DGT) technique and high-resolution dialysis (HR-Peeper) with microbial characterization analysis along the vertical sediment profile to examine the effect mechanism of the FNA-based inhibition process on sulfide production in the sediments. The results revealed that the FNA-based exposure strategy could effectively suppress the sulfidogenic activity across the whole shallow active layer (approximately 0.5cm below the surface) in the sediments. An initial high FNA concentration up to 2.5mg HNO2-N/L was required to maintain a critical inhibition level (24-h average concentration>0.2mg HNO2-N/L) across the whole active sediment zone. The FNA concentration decreased sharply deeper than 0.5cm with a significant pH increase, resulting in FNA inactivation only reducing the microbial live/total ratio and shifting the microbial community structure near the sediment surface. Maintaining a low pH is the critical factor for the FNA-based suppression strategy of the sulfidogenic activity in the shallow sediment zone.

Increased frequency of PD-1hiCXCR5- T cells and B cells in patients with newly diagnosed IgA nephropathy

Recent research has identified a population of PD-1hiCXCR5− ‘peripheral helper’ T (Tph) cells that simulate plasma cell differentiation by interactions between IL-21 and SLAMF5. However, the alteration of circulating Tph and CD138+ B in IgA nephropathy (IgAN) remains poorly understood. Flow cytometry analysis was used to measure the frequency of circulating PD-1hiCXCR5− T cells and CD138+ B cells in 37 patients with IgAN and 23 healthy controls (HCs). Estimated glomerular filtration rate (eGFR), 24 h urinary protein and serum cytokine concentrations were measured. The percentage of different subsets of circulating PD-1hiCXCR5− T cells and CD138+ B cells were significantly higher in patients with IgAN compared to HCs. Pretreatment, the percentage of different subsets of circulating PD-1hiCXCR5− T cells and CD138+ B cells were negatively correlated with eGFR, the percentage of circulating CD138+ B cells was positively correlated with 24-h urinary protein concentration, and the percentage of circulating PD-1hiCXCR5−, CD28+ and ICOS+ T cells. Posttreatment, the percentage of different subsets of circulating PD-1hiCXCR5− T cells and CD138+ B cells and serum IL-21 concentration were significantly reduced. Different subsets of circulating PD-1hiCXCR5− T cells contribute to the progression and pathogenesis of IgAN by regulating the differentiation of CD138+ B cells through a combination of surface molecules.

Prediction of Potentially High PM2.5 Concentrations in Chengdu, China

Daily exposure to high ambient PM2.5 increases the mortality rate and contributes significantly to the burden of disease. In basin-situated cities with high local emissions of air pollutants, meteorological conditions play a crucial role in forming air pollution. One such city is Chengdu, which is located in the Sichuan Basin and serves as the economic, educational, and transportation hub of western China. Particulate matter with an aerodynamic diameter of < 2.5 µm (PM2.5) is the most critical pollutant in this city. Although the annually averaged PM2.5 concentrations declined from 92 to 57 µg m–3 between 2013 and 2017, the city still suffers from haze and smog, with 85 days during 2017 displaying 24-h PM2.5 concentrations > 75 µg m–3. To better understand the influence of meteorological factors on PM2.5 pollution with the goal of easily and reliably predicting the latter, we examined the relationships between the 24-h concentration and a variety of meteorological parameters in Chengdu. We found that the strongest predictors of the PM2.5 concentration were the temperature, precipitation, wind speed, and trajectory direction and distance. Furthermore, although the same-day sea-level pressure (SLP) was a weak predictor, the SLP 5 days in advance performed better. We developed generalized additive models (GAMs) that predicted the PM2.5 concentration as a function of multiple meteorological parameters. One of the GAMs developed in this study exhibited an adjusted correlation coefficient (R2) of 0.73 and captured up to 73.9% of the variance in the daily averaged PM2.5 concentrations. The model performance was improved by using the ΔSLP (i.e., mean pressure difference) for 5 days instead of the SLP, suggesting that ΔSLP5d is a good predictor of high concentration days in Chengdu. This study provides a useful tool for controlling emissions in advance to prevent heavy pollution days and issuing outdoor activity warnings to protect public health.