High Concentrations Of NO Research Articles

A Low Temperature NO2 Sensor Based on SnSe2/SnO2 Heterojunction

IntroductionNitrogen dioxide (NO2) is one of the main air pollutants. A Higher concentration of NO2 may cause serious damage to respiratory system and even death. Therefore, it is necessary to develop a low-energy consumption gas sensor which can sensitive and accurate analysis of NO2 in the atmosphere.In this aspect, two dimensional (2D) layered nanostructured materials such as metal dichalcogenides (MX2, M=Mo, Sn etc..; X=S, Se etc..) have received widespread attentions in NO2 detection due to their high specific surface area and unique electrical properties[1]. For example, SnS2 demonstrated excellent NO2 sensing properties [2]. Moreover, as reported in literature [3], the formation of SnO2/SnS2 heterostructure is beneficial to the further improvement of sensing performance. However, the gas sensing properties of SnSe are rarely reported. Therefore, the gas sensing properties of SnSe2 and SnSe2/SnO2 heterojunctions have investigated in this work.Experiment The SnSe2 powder was purchased from Chengdu Alfa Metal Material Co. Ltd. After grinding for half an hour, the SnSe2 powder was dispersed in an alcohol solution to obtain suspension by ultrasonic treatment. The paste was deposited onto the alumina substrates with Au interdigital electrodes. Then, the sensors were dried at 70 °C for 12 h. The SnO2/SnSe2 heterojunction based sensor was obtained by in-situ oxidation SnSe2 at 500 °C for 1 h in simulation air which is composed of 84.8 % dry nitrogen and 15.2 % dry oxygen. For comparison, the SnO2 sensor was also prepared by in-situ oxidation SnSe2 at 750 °C. Results and conclusions 1. Structure and MorphologyFig.1a shows the XRD patterns of SnSe2, SnO2 and SnO2/SnSe2, respectively. For the SnO2/SnSe2 sample, the diffraction peaks located at (001), (002), (003), (004), (005) lattice planes are assigned to the hexagonal SnSe2 (JCPDS Card No. 89-2939) [4], and the other diffraction peaks are consistent with tetragonal SnO2 (JCPDS No. 41-1445). No third phase was observed in the SnO2/SnSe2 sample indicating the product with high purity. This is consistent with the HRTEM analysis. As shown in Fig. 1(b), the fringe spacing of 0.296 nm and 0.192 nm are corresponded to the d-spacing of (002) and (003) crystal planes of SnSe2, whereas the fringe spacing of 0.340 nm and 0.265 nm are assigned to the d-spacing of (110) and (101) crystal planes of SnO2. Additionally, the EDX mapping images and EDX spectrum of SnO2/SnSe2 sample are shown in Fig.1c-d. It can be noticed that there only exist Sn, Se, and O elements in the composites material, and Sn (yellow), Se(red), and O (green) elements are uniformly distributed in the material, which confirming that the formation of SnO2 nanocrystals on the surface of SnSe2 and the oxidation of SnSe2 to SnSe2/SnO2 is partial.2. Gas-Sensing PropertiesFig. 2a shows the dynamic response and recovery curve of sensors to 8 ppm NO2 at 120 °C. Compared to pristine SnSe2 and SnO2 based sensor, the SnSe2/SnO2 based sensor exhibits the highest response value (5.6), which is approximately 10 times higher than that of SnSe2 based sensor (0.54). In contrast, since SnO2 didn’t work at the optimum temperature (usually at 200-400 °C), the redox reactions to induce a sensor response were almost inertia at 120 °C. The selectivity of the SnSe2/SnO2 based sensor to several VOCs, including ethanol, ammonia, formaldehyde, acetone and methanol at 8 ppm in Fig. 2b. The response towards 8 ppm NO2 is much higher compared to the other tested gases indicating a possible excellent selectivity towards NO2. The above results fully prove that the formation of SnSe2/SnO2 heterojunctions can enhance the sensing performance of materials.

Particulate Nitrosamines and Nitramines in Seoul and Their Major Sources: Primary Emission versus Secondary Formation.

Seven nitrosamines and three nitramines in particulate matter with an aerodynamic diameter of less than or equal to 2.5 μm (PM2.5) collected in 2018 in Seoul, South Korea, were quantified. Annual mean concentrations of the sum of nitrosamines and nitramines were 9.81 ± 18.51 and 1.12 ± 0.70 ng/m3, respectively, and nitrosodi-methylamine (NDMA) and dimethyl-nitramine (DMN) comprised the largest portion of nitrosamines and nitramines, respectively. Statistical analyses such as non-parametric correlation analysis, positive matrix factorization, analysis of covariance, and orthogonal partial least squared discrimination analysis were carried out to identify contribution of the atmospheric reactions in producing NDMA and DMN. In addition, kinetic calculation using reaction information obtained from the previous chamber studies was performed to estimate concentrations of NDMA and DMN that might be produced from the atmospheric reactions. It was concluded that (1) the atmospheric reactions contributed to the concentrations of NDMA more than they did for those of DMN, (2) the contribution of atmospheric reactions to the concentrations of NDMA and DMN was significant due to high NO2 concentrations in winter, and (3) primary emissions predominantly affected the ambient concentrations of NDMA and DMN in spring, summer, and autumn.

Particle-Phase Photoreactions of HULIS and TMIs Establish a Strong Source of H2O2 and Particulate Sulfate in the Winter North China Plain.

During haze periods in the North China Plain, extremely high NO concentrations have been observed, commonly exceeding 1 ppbv, preventing the classical gas-phase H2O2 formation through HO2 recombination. Surprisingly, H2O2 mixing ratios of about 1 ppbv were observed repeatedly in winter 2017. Combined field observations and chamber experiments reveal a photochemical in-particle formation of H2O2, driven by transition metal ions (TMIs) and humic-like substances (HULIS). In chamber experiments, steady-state H2O2 mixing ratios of 116±83 pptv were observed upon the irradiation of TMI- and HULIS-containing particles. Correspondingly, H2O2 formation rates of about 0.2 ppbv h-1 during the initial irradiation periods are consistent with the H2O2 rates observed in the field. A novel chemical mechanism was developed explaining the in-particle H2O2 formation through a sequence of elementary photochemical reactions involving HULIS and TMIs. Dedicated box model studies of measurement periods with relative humidity >50% and PM2.5≥75μgm-3 agree with the observed H2O2 concentrations and time courses. The modeling results suggest about 90% of the particulate sulfate to be produced from the SO2 reaction with OH and HSO3- oxidation by H2O2. Overall, under high pollution, the H2O2-caused sulfate formation rate is above 250 ng m-3 h-1, contributing to the sulfate formation by more than 70%.

High NO2 Concentrations Measured by Passive Samplers in Czech Cities: Unresolved Aftermath of Dieselgate?

This work examines the effects of two problematic trends in diesel passenger car emissions—increasing NO2/NOx ratio by conversion of NO into NO2 in catalysts and a disparity between the emission limit and the actual emissions in everyday driving—on ambient air quality in Prague. NO2 concentrations were measured by 104 membrane-closed Palmes passive samplers at 65 locations in Prague in March–April and September–October of 2019. NO2 concentrations measured by city stations during those periods were comparable with the average values during 2016–2019. The average measured NO2 concentrations at the selected locations, after correcting for the 18.5% positive bias of samplers co-located with a monitoring station, were 36 µg/m3 (range 16–69 µg/m3, median 35 µg/m3), with the EU annual limit of 40 µg/m3 exceeded at 32% of locations. The NO2 concentrations have correlated well (R2 = 0.76) with the 2019 average daily vehicle counts, corrected for additional emissions due to uphill travel and intersections. In addition to expected “hot-spots” at busy intersections in the city center, new ones were identified, i.e., along a six-lane road V Holešovičkách. Comparison of data from six monitoring stations during 15 March–30 April 2020 travel restrictions with the same period in 2016–2019 revealed an overall reduction of NO2 and even a larger reduction of NO. The spatial analysis of data from passive samplers and time analysis of data during the travel restrictions both demonstrate a consistent positive correlation between traffic intensity and NO2 concentrations along/near the travel path. The slow pace of NO2 reductions in Prague suggests that stricter vehicle NOx emission limits, introduced in the last decade or two, have so far failed to sufficiently reduce the ambient NO2 concentrations, and there is no clear sign of remedy of Dieselgate NOx excess emissions.

Risk of cerebrovascular accidents according to weather and pollution features

Abstract Funding Acknowledgements Type of funding sources: None. BACKGROUND Despite mounting evidence, there is uncertainty on the impact of the interplay between weather and pollution features on the risk of acute cerebrovascular events (CVE). PURPOSE We aimed at appraising role of weather and pollution on the daily risk of CVE. METHODS Anonymized data from a hub CVE center in a metropolitan area were collected analyzed according to weather and pollution on the same and the preceding days. Generalized additive models were used to explore the impact of individual and combined factors on the risk of daily CVE. RESULTS We collected data from 2012 to 2017, including a total of 2534 CVE, with a 1.56 daily rate (bootstrapped 95% confidence interval 1.48-1.64). In particular, CVE were distinguished as follows: ischemic stroke, hemorrhagic stroke, arterial dissection, ruptured aneurysm, and transient ischemic attacks, with daily rates ranging from 1.422 for stroke to 0.005 for ruptured aneurysm. Unadjusted analysis showed that daily temperature, atmospheric pressure, and humidity, among weather features, were all significantly associated with CVE (all P < 0.05). Similarly, concentrations of carbon monoxide, nitrogen dioxide, nitrogen oxides, ozone, and particulate matter <10 µm (PM10), among pollution features, were all significantly associated with CVE (all P < 0.05). Multivariable analysis, also adjusted for season, showed that CVE were significantly and inversely associated with same-day minimum temperature (P < 0.001), atmospheric pressure (P = 0.007), and humidity (P < 0.001), as well as significantly and positively associated with nitrogen dioxide (P = 0.005) and PM10 (P < 0.001). CONCLUSION Cerebrovascular events, and stroke in particular, are more common in days with lower temperature, pressure and humidity, and higher concentrations of NO2 and PM10. Abstract Figure. Association between PM10 and CVE

Short-time irrigation on young olive tree (Olea europaea L. cv. Chemlali) with untreated industrial poultry wastewater: investigation of growth parameters and leaves chemical composition.

The purpose of this study was to evaluate the short-term irrigation effect with industrial poultry wastewater on young olive trees (Olea europaea L. cv. Chemlali). Industrial poultry wastewater can be considered as a bio-fertilizer due to its richness in nutritive elements (SO42-, HCO3-, total nitrogen, and K+). The physicochemical analysis of wastewater showed a high concentration of TSS, COD, BOD, COT, NO3-, and conductivity. Measurements indicated that poultry wastewater enhanced plant growth, leaves dry matter, and ashes in comparison with tap water, as well as poultry wastewater diluted with tap water; however, a decrease in total soluble sugars (glucose and fructose) was detected in leaves. The determination of fatty acid profile of young olive trees leaves irrigated with poultry wastewater showed richness on saturated fatty acids in comparison with mono- and poly-unsaturated ones. In addition, oleic acid (C18:1) presented the lowest content in leaves of trees irrigated with poultry wastewater irrigation. According to those results, poultry wastewater lends itself to being a hydric alternative and at the same time a source of nutrients that can help fill the water deficit in semi-arid countries and avoid costly waste disposal for slaughterhouses.

High Level of Nitrogen Dioxide in Ambient Air Increased Incidence of Influenza in Children: An Observational Study in China

Background: The roles of air pollutants including nitrogen dioxide (NO2), sulfur dioxide (SO2), carbon monoxide (CO) and ozone (O3) in influenza incidence at nationwide level of China remained obscure. Methods: Data from two complementary nation-wide influenza surveillance systems were applied to examine the association between air pollutants and influenza incidences. Spatial epidemiological analyses were performed on both air pollutants and influenza incidences in 31 provinces of mainland China. Cities with consistent data patterns between the two surveillance systems were chosen to examine the effects of pollutants on monthly influenza incidences using generalized estimating equations (GEE) and on daily incidence using the distributed lag non-linear model (DLNM). Results: Out of five common air pollutants (NO2, SO2, O3, CO, PM2.5), the concentration of NO2 was found spatially correlated with annual average influenza positive rates at province level (Pearson’s correlation coefficient=0.69, P<0.001). Based on data from 134 cities, NO2 and SO2 were found positively associated with monthly influenza incidences with estimated RRs of 1.22 and 1.09, respectively. The RRs increased to 1.45 and 1.13 among children younger than 18 years. NO2 is the only pollutant that showed robust positive association with daily influenza incidence in 12 of the 18 cities with adequate daily incidence data. The positive association was found in children under 18 years but not in adults. Interpretation: A higher NO2 concentration in ambient air was associated with an increased incidence of influenza across a wide geographic range in China with more vulnerable impact in Children. These findings reflect the need for annual vaccination campaign among children and their parents as well as air pollution control in densely populated urban areas. Funding Information: The National Natural Science Foundation of China; The China Mega-Project on Infectious Disease Prevention; The Key Research and Development Program of China; The US National Institutes of Health grant. Declaration of Interests: All authors have completed the ICMJE uniform disclosure form at www.icmje.org/coi_disclosure.pdf and declare: no support from any organization for the submitted work; no financial relationships with any organizations that might have an interest in the submitted work in the previous three years; no other relationships or activities that could appear to have influenced the submitted work. Ethics Approval Statement: The current study was approved by Beijing Institute of Microbiology and Epidemiology in accordance with the medical research regulations of China.

Mechanism of nitrous oxide (N2O) production during thermal stratification of a karst, deep-water reservoir in southwestern China

Reservoirs are hotspots of greenhouse gas (GHG) emission, and the global warming potential of nitrous oxide (N2O) is higher than that of CO2 and CH4. To promote our understanding of the relationship of biotic and abiotic environments with the mechanism of N2O production in a quintessential karst reservoir, water samples were collected in a weak thermal stratification period (WTSP) and a strong thermal stratification period (STSP) in 2019 in the Longtan (LT) Reservoir. In the LT Reservoir, higher N2O concentrations and functional gene abundances (nitrification and denitrification genes) were found in the STSP than in the WTSP. In detail, the N2O concentrations were 10.45 ± 6.99 nmol L−1 and 23.77 ± 7.06 nmol L−1 in the WTSP and STSP, respectively; the functional gene abundances were higher in the STSP than in the WTSP in each water layer. During the STSP, the nitrification gene abundances were higher at a 30 m depth than at a 100 m depth, while denitrification gene abundances were higher at 100 m than at 30 m. Along the river, N2O flux was significantly higher in the LT Reservoir’s released water than in upstream water in the STSP, while it exhibited no significant difference in whole river-reservoir system in the WTSP. In conclusion, stratification and nitrogen (N) loading facilitated higher N2O production in STSP than in WTSP; different N transformation processes and sources of N2O were present between the water layers above and below the thermocline (in deep water); finally, the river-reservoir system here acted as a source of N2O release to the atmosphere in the STSP, while it exhibited different emission patterns in the WTSP. This work highlights the mechanism of N2O production and functional gene abundances in water layers during different thermal stratification periods, which will help to elucidate the biotic and abiotic environment in a karst deep-water reservoir and will help to inform N2O production mechanisms in other reservoirs worldwide. More sampling campaigns and the denitrification potential of sediment were worthy of conducting to comprehend the mechanisms of N2O production from stratification to turnover period in the reservoir.

Impact of Water Vapor on the Performance of a Cu-SSZ-13 Catalyst under Simulated Diesel Exhaust Conditions

&lt;div class="section abstract"&gt;&lt;div class="htmlview paragraph"&gt;Cu-SSZ-13 selective catalytic reduction (SCR) catalysts are broadly applied in diesel aftertreatment systems for the catalytic conversion of oxides of nitrogen (NO + NO&lt;sub&gt;2&lt;/sub&gt;). Diesel exhaust contains a wide range of water vapor concentrations depending on the operating condition. In this study, we evaluate the impact of water vapor on the relevant SCR catalytic functions including NO&lt;sub&gt;x&lt;/sub&gt; conversion, NO oxidation, NH&lt;sub&gt;3&lt;/sub&gt; oxidation, and N&lt;sub&gt;2&lt;/sub&gt;O formation under both standard and fast SCR conditions. Reactor-based experiments are conducted in the presence and absence of water vapor. Results indicate that water vapor can have both a positive and negative impact on low temperature NO&lt;sub&gt;x&lt;/sub&gt; conversion for standard SCR reaction. At low inlet NO&lt;sub&gt;x&lt;/sub&gt; concentrations, the presence of water vapor has a negative effect on NO&lt;sub&gt;x&lt;/sub&gt; conversion, whereas, at high inlet NO concentrations, water vapor improves NO&lt;sub&gt;x&lt;/sub&gt; conversion. At high temperatures, water vapor has a beneficial effect on NO&lt;sub&gt;x&lt;/sub&gt; conversion at all NO&lt;sub&gt;x&lt;/sub&gt; inlet concentrations evaluated. Experiments under fast SCR conditions reveal that water vapor improves low temperature NO&lt;sub&gt;x&lt;/sub&gt; conversion mainly by minimizing the accumulation of ammonium nitrate, as evidenced with temperature programmed desorption (TPD) results. Furthermore, NO oxidation by ammonium nitrate formed under fast SCR conditions is shown to be significantly faster in the presence of water vapor.&lt;/div&gt;&lt;/div&gt;

Effect of Gas Components and Particulate Matter on the Conversion of Nitric Oxide by Dielectric Barrier Discharge

The conversion of nitric oxide by dielectric barrier discharge (DBD) in different reaction gases (O2, H2O, Ar, and N2) was studied. In the N2/O2 system, N and O could react to form NO; consecutively, extra O would oxidize NO to form NO2. Increase of oxygen content would promote the generation of NO, and the highest concentration of NO2 could be obtained with different oxygen contents at specific energy inputs (SEIs) of 1200 or 1440 J/L. In the N2/O2/NO system, the oxidation and reduction of NO took place simultaneously to form NO2 and N2, and NO was mainly removed by reduction when the oxygen content was lower than 6 vol %. In comparison, in the Ar/O2/NO system, NO was mainly oxidized to NO2. However, when the oxygen content exceeded 12 vol %, the increase of the SEI between 960 and 1440 J/L will increase the temperature of the DBD reactor, resulting in the restrain of the NO oxidation rate. In the SO2/N2/O2/NO system, SO2 could be oxidized by O radicals in the discharge region, leading to the restrain of NOx generation. In the H2O/N2/O2/NO system, H2O could promote the oxidation of NO so that NO conversion could reach 100% at 18 vol % O2 content. In the system of particulate matter/N2/O2/NO, particles would change the parameters in the discharge region and promote the production of N and O radicals, leading to the concentrations of NO2 and NOx being higher than those in the N2/O2/NO system. When the oxygen content was lower than 6 vol %, the conversion of NO reached 100% at 960 J/L. N2O formed in all systems as a byproduct of NO conversion by DBD. With the increase of the SEI, part of N was oxidized, resulting in the increase of NOx in all the systems containing N2.

Catalytic nonthermal plasma using efficient cobalt oxide catalyst for complete mineralization of toluene

The remarkable rise in industrial utilization of volatile organic compounds has increased their presence in environmental matrices, which is a menace for human health. Conventionally, many technologies are in practice for constricting their escape to the environment. However, due to associated adverse health hazards, more efficient technique ensuring complete mineralization is inevitably demanded. In the current study, the degradation of toluene by post-plasma catalysis using cobalt-coupled (Co3O4–CoO) catalyst was studied. Firstly, a new starch-assisted synthesis route for cobalt coupling is presented. Secondly, the research finding of this study showed that the formed cobalt couple exhibited robust performance for toluene degradation up to 99%, which was attributed to their enhanced redox property and adsorbed oxygen content. This promotion in catalytic ability is due to intrinsically greater oxygen storage capacity of coupling. Additionally, the results of this study indicated that toluene degradation was increased significantly with higher input power, whereas, without catalyst application, nonthermal plasma (NTP) alone produced other VOCs as a result of toluene degradation and higher NO concentration at high input power and higher O3 at low input power. Furthermore, it could be concluded that NTP along with cobalt-coupled catalyst promotes toluene degradation, controls the production of all other VOCs and O3 and significantly reduced the production of NO concentration.

Source of 226Ra in Ramsar spring water, Iran: implication of water–rock interaction and stable isotopes

This study was carried out primarily to understand the hydrogeochemical processes controlling the 226Ra anomalies in Ramsar area. Analyses revealed two types of water: (1) non-thermal Ca–HCO3 type and (2) thermal Na–Cl type, mainly of meteoric and hydrothermal origin, respectively. Non-thermal springs have higher concentrations of U due to silicate weathering. Thermal springs are characterized by high concentrations of 226Ra, As, Fe, Li, Cs, Rb, Sr, Ba, B, Br−, F−, NO3−, PO43− and SiO2 resulting from high-temperature water–rossck interaction and mixing with hydrothermal fluids. Thermal springs are manifestations of an old hydrothermal system with subsurface reservoir temperatures varying between 83 and 100 °C. Radium activity is negatively correlated with pH and positively correlated with TDS, Cl−, Ba, and Ca, reflecting competitive ion effects of alkaline-earth metals, complexing with Cl−, and co-precipitation with barite and calcite. These processes are thought to be the dominant factors in controlling 226Ra mobility in spring water.

Pelagic denitrification and methane oxidation in oxygen-depleted waters of the Louisiana shelf

Anthropogenic nutrient inputs fuel eutrophication and hypoxia ([O2] < 2 mg L−1), threatening coastal and near shore environments across the globe. The world’s second largest anthropogenic coastal hypoxic zone occurs annually along the Louisiana (LA) shelf. Springtime loading of dissolved inorganic nitrogen (DIN) from the Mississippi River, combined with summertime stratification and increased water residence time on the shelf, promotes establishment of an extensive hypoxic zone that persists throughout the summer. We investigated the patterns of pelagic denitrification and methane (CH4) oxidation along the LA shelf. Microbial activity rates were determined along with concentrations of dissolved nutrients and greenhouse gases, nitrous oxide (N2O) and CH4, during summer in 2013, 2015, and 2016. We documented denitrification rates up to 1900 nmol N L−1 d−1 and CH4 oxidation rates as high as 192 nmol L−1 d−1 in hypoxic waters characterized by high concentrations of N2O (range: 1 to 102 nM) and CH4 (range: 3 to 641 nM). Ecosystem scaling estimates suggest that pelagic denitrification could remove between 0.1 and 47% of the DIN input from the Mississippi River, whereas CH4 oxidation does not function as an effective removal process with CH4 escaping to the atmosphere. Denitrification and CH4 oxidizing bacteria within the LA shelf hypoxic zone were largely unable to keep up with the DIN and CH4 inputs to the water column. Rates were variable and physiochemical dynamics appeared to regulate the microbial removal capacity for both nitrate/nitrite and CH4 in this ecosystem.

Discovery of β-carboline-(phenylsulfonyl)furoxan hybrids as potential anti-breast cancer agents

The cytotoxicity properties of the β-carboline alkaloids have been broadly investigated. However, the potential application of β-carbolines was hindered due to the moderate activity in cancer. In the present study, thirty β-carboline-(phenylsulfonyl)furoxan hybrids (11a–j, 12a–j and 13a–j) were designed and synthesized through esterification and amidation reaction strategy, and their inhibitory activities against the human breast cancer cell lines MCF-7 and MDA-MB-231 were evaluated by CCK-8 assay. Biological evaluation presented that the most promising amide derivative 13h, substituted with p-methoxyphenyl group at position 1, generated high concentration of NO and evidently depressed the MCF-7 (IC50 = 0.89 μM) and MDA-MB-231 (IC50 = 0.62 μM) cells proliferation. Particularly, the wound healing and transwell assays demonstrated that 13h significantly inhibited the migration and invasion of MDA-MB-231cells. Furthermore, the preliminary mechanisms studies indicated that 13h induced G2/M phase arrest and apoptosis possibly causing by ROS accumulation and ROS-mediated DNA damage. Based on these considerations, 13h may be a promising antimetastatic agent for breast cancer, which is noteworthy for further exploration.

Short-term association among meteorological variation, outdoor air pollution and acute bronchiolitis in children in a subtropical setting

ObjectivesTo examine the association among acute bronchiolitis-related hospitalisation in children, meteorological variation and outdoor air pollution.MethodsWe obtained the daily counts of acute bronchiolitis-related admission of children≤2 years old from all...

Association between ambient air pollution and high-risk pregnancy: A 2015–2018 national population-based cohort study in Korea

BackgroundSeveral studies have indicated that prenatal exposure to ambient air pollution is associated with an increased risk of gestational diabetes mellitus, hypertensive disorder during pregnancy, preterm birth, and stillbirth. However, no previous study has focused on the association between the number of pregnancy complications and exposure to ambient air pollution. ObjectivesTo investigate the association between prenatal exposure to ambient air pollutants and the number of pregnancy complications in high-risk pregnancies. MethodsWe collected data on gestational diabetes mellitus, hypertensive disorder during pregnancy, preterm birth, and stillbirth from the National Health Information Databases, provided by the Korean National Health Insurance Service.R To assess individual-level exposure to air pollutants, a spatial prediction model and area-averaging approach were used. ResultsFrom 2015 to 2018, data of 789,595 high-risk pregnancies were analyzed. The ratio of gestational diabetes mellitus in the country was the highest, followed by preterm birth, hypertensive disorder during pregnancy, and stillbirth. Approximately 71.7% of pregnant women (566,143) presented with one pregnancy complication in identical pregnancies, 27.5% (216,714) presented with two, and 0.9% (6738) presented with three or more. Multiple logistic regression models with adjustments for age, residence, and income variables indicated that the risk of having two or more pregnancy complications was positively associated with the exposure to higher levels of PM10 (odds ratio [OR], 1.11; 95% confidence interval [CI], 1.09–1.12) and PM2.5 (OR, 1.14; 95% CI, 1.12–1.15). The highest quartile presented higher odds of two or more pregnancy complications compared with the lower three quartiles of PM10, PM2.5, CO, NO2, and SO2 exposures (p < 0.001). ConclusionThe results indicate that the risk of pregnancy complications is positively associated with the exposure to the high concentrations of PM10, PM2.5, CO, NO2, and SO2.

Stream water chemistry changes in response to deforestation of variable origin (case study from the Carpathians, southern Poland)

The purpose of the study was to examine the effects of deforestation of variable origin on the stream water chemistry, with a special focus on the NO3– ion. The research was conducted in 8 small catchments in the Tatra Mountains and 7 small catchments in the Beskid Śląski Mountains (the Carpathians, Poland). Relevant deforestation events occurred in the Beskid Śląski Mountains in the 1980s and 1990s, and were caused by intense acidic atmospheric deposition in the 1970s and 1980s, while tree stands in the Tatra Mountains were damaged abruptly by hurricane-force winds in 2013 and gradually by the bark beetle since the late 1990s.We show the key role of deforestation in the concentration of base cations (Ca2+, Mg2+), base anions (SO42-, HCO3–), and NO3– in stream water in catchments affected by acidic deposition. The lack of forest reduces the release of Ca2+, Mg2+ and HCO3– due to lower weathering rates in deforested areas than in forested areas. The absence of trees capable of absorbing atmospheric SO42- and NO3– in deforested catchments leads to a higher proportion of stream water SO42- and NO3– in the anion total than in forested catchments.The time passed since deforestation and degree of deforestation play a key role in NO3– concentration in stream water. The highest concentrations of NO3– were noted in stream water in freshly and fully hurricane-deforested catchments in the Tatra Mountains. The stream water NO3– concentration was markedly lower in a beetle-deforested catchment where only 40% of the forest had become damaged while the lowest NO3– concentrations were noted in more than 60% forested catchments. The most distinct seasonal changes in NO3– concentrations in stream water and in soils were noted in freshly and fully hurricane-deforested catchments.

Au Catalyzing Control Release NO in vivo and Tumor Growth-Inhibiting Effect in Chemo-Photothermal Combination Therapy.

IntroductionAim to obtain a NO donor that can control released NO in vivo with the high efficacy of tumor suppression and targeting, a nanoplatform consisting of FA-Fe3O4@mSiO2-Au/DOX was constructed.MethodsIn vitro, the nanoplatform catalyzed NO’s release with the maximum value of 4.91 μM within 60 min at 43°C pH=5.0, which was increased by 1.14 times when the temperature was 37°C. In vivo, 11.7 μg Au in the tumor tissue was found to catalyze S-nitrosoglutathione continuously, and 54 μM NO was checked out in the urine.Results and DiscussionThe high concentration of NO was found to increase the apoptotic rate and to reduce tumor proliferation. In the chemo-photothermal combination therapy, the tumor inhibition rate was increased up to 94.3%, and Au’s contribution from catalyzing NO release NO was 8.17%.

Patterns and trends of ozone and carbon monoxide at Ushuaia (Argentina) observatory

The behavior patterns for surface ozone (O3) and carbon monoxide (CO) were investigated with the hourly mixing ratios registered for nine years (2010 to 2018) at the GAW-WMO (Global Atmospheric Watch – World Meteorological Organization) station of Ushuaia (Argentina). Two behavior patterns were identified for these species after applying a criterion. Specific periods were analyzed in detail, in which nitrogen dioxide (NO2) was also studied. The weather conditions were explored using the ERA5 meteorological fields from the ECMWF (European Centre for Medium-Range Weather Forecasts). Outputs of the chemical transport model from the Copernicus Atmosphere Monitoring Service (CAMS) were used to investigate the spatial distribution of O3, CO and NO2. The more frequent scenario is characterized by the unaltered mixing ratios of O3 and CO for days, with values of 10–15 ppb and 60–70 ppb, respectively, and below 200 ppt for NO2. This pattern occurred with intense westerly airflows associated with the low-pressure system located in the south of the Pacific Ocean. A second pattern was observed in 45.8 ± 3.4% of the days, which was characterized by low O3 mixing ratios (~12 ppb), high NO2 concentrations (above ~3000 ppt) and CO peaks exceeding 400 ppb. This scenario was defined by a high-pressure system blocking the westerly winds, which results in atmospheric stagnation and in the accumulation of trace gases in the lower layers. Finally, the annual trend was explored; no O3 trend was obtained, although an unexpected upward CO trend was identified, with an increase of 1.75 ± 0.49 ppb year−1. To investigate its causes, the annual evolution of the temperature at 850 hPa level (T850) and geopotential height at 500 hPa level (Z500) anomalies along with the CO emissions were analyzed. While no trends were found in weather conditions, the CO emissions showed an increasing trend of 4.4% year−1; therefore, the CO increase could be attributed to the emission changes. In the future, warm climate with more frequent anticyclonic situations, together with a growing trend in emissions, could lead to a drastic change in the current levels of these trace gases, in remote regions such as Ushuaia.

Entropy-weighted water quality index (EWQI) modeling of groundwater quality and spatial mapping in Uppar Odai Sub-Basin, South India

Groundwater is the primary source of water supply in Uppar Odai Sub-basin in the Amaravati River basin in South India. In this crystalline aquifer system, groundwater occurs in joints fissures, fractures at shallow depth in the partially weathered rocks. An integrated approach of hydrochemical analysis of 32 samples with numerical indexing Entropy-weighted water quality index(EWQI) model was proposed for the study area. General hydrochemical data showed that the Na–Cl and Ca–Mg–Cl–SO4 types dominated, with most of the samples are alkaline nature. More than 50% of the samples exceeded the permissible limit of TDS, and a high concentration of Cl and NO3 showed the influence of anthropogenic influences, such as industrial effluents and agricultural fertilizers. Groundwater chemistry was found to be varying along the groundwater flow paths. Geogenic contaminant F¯ was exceeding the WHO permissible limit of 1.5 mg/L. Entropy-weighted Water Quality Index (EWQI) model showed that 53% of the samples were medium, and 22% were of poor quality. Na–Cl and mixed Ca–Mg–Cl types of water were reported with high EWQI values. A high correlation for EWQI with TDS, TH, Mg, Cl, SO4, and NO3 is an indication of the human activities on the groundwater quality. GIS-based spatial variation maps of water quality parameters and EWQI specify that northern, northwestern, and central regions are poor water quality. In those regions where water quality has deteriorated, proper treatment of water is suggested before consumption to avoid health risks.