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Kyle D Custard, Kerri A Pratt, Siyuan Wang, Paul B Shepson
During springtime, unique halogen chemistry involving chlorine and bromine atoms controls the prevalence of volatile organic compounds, ozone, and mercury in the Arctic lower troposphere. In situ measurements of the chlorine monoxide radical (ClO) and its precursor Cl2, along with BrO and Br2, were conducted using chemical ionization mass spectrometry (CIMS) during the BRomine, Ozone, and Mercury EXperiment (BROMEX) near Barrow, Alaska in March 2012. To our knowledge, these data represent the first ClO measurements made using CIMS...
October 21, 2016: Environmental Science & Technology
R Kelman Wieder, Melanie A Vile, Kimberli D Scott, Cara M Albright, Kelly McMillen, Dale H Vitt, Mark Fenn
Oil extraction and development activities in the Athabasca Oil Sands Region of northern Alberta, Canada release NOx, SOx, and NHx to the atmosphere, ultimately resulting in increasing N and S inputs to surrounding ecosystems through atmospheric deposition. Peatlands are a major feature of the northern Alberta landscape, with bogs covering 6-10% of the land area, and fens covering 21-53%. Bulk deposition of NH4+-N, NO3--N, total inorganic N (TIN), and SO42--S, was quantified using ion exchange resin collectors deployed at 23 locations, over 1-6 years, reveal maximum N and S deposition of 9...
October 21, 2016: Environmental Science & Technology
Scott Whitehouse, Pei-Lin Chen, Anna L Greenshields, Mat Nightingale, David W Hoskin, Karen Bedard
BACKGROUND: Many plant-derived chemicals have been studied for their potential benefits in ailments including inflammation, cancer, neurodegeneration, and cardiovascular disease. The health benefits of phytochemicals are often attributed to the targeting of reactive oxygen species (ROS). However, it is not always clear whether these agents act directly as antioxidants to remove ROS, or whether they act indirectly by blocking ROS production by enzymes such as NADPH oxidase (NOX) enzymes, or by influencing the expression of cellular pro- and anti- oxidants...
November 15, 2016: Phytomedicine: International Journal of Phytotherapy and Phytopharmacology
Francisco Molina, María Luisa Del Moral, María Ángeles Peinado, Alma Rus
BACKGROUND: Nitric oxide (NO) appears to play a key role in the hypoxic injury to the brain. We have previously reported that hypoxia/reoxygenation downregulated NO synthases (NOS) in the adult striatum. Until now, no data were available concerning the influence of aging in conjunction with hypoxia/reoxygenation on the NO system in the striatum. OBJECTIVE: The aim of this study was to assess the role of the NO pathway in the hypoxic aged striatum. METHODS: Wistar rats 24-25 months old were submitted to hypobaric hypoxia (20 min)/reoxygenation (0 h, 24 h, 5 days)...
October 20, 2016: Gerontology
Florian Rouaud, Jean-Luc Boucher, Anny Slama-Schwok, Stéphane Rocchi
Melanoma is one of the most lethal cancers when it reaches a metastatic stage. Despite the spectacular achievements of targeted therapies (BRAF inhibitors) or immuno-therapies (anti-CTLA4 or anti-PD1), most patients with melanoma will need additional treatments. Here we used a photoactive NADPH analogue called NS1 to induce cell death by inhibition of NADPH oxidases NOX in melanoma cells, including melanoma cells isolated from patients. In contrast, healthy melanocytes growth was unaffected by NS1 treatment...
October 14, 2016: Oncotarget
Jiaming Li, Robert H Grubbs, Brian M Stoltz
A mild aerobic intramolecular aminoacetoxylation method for the synthesis of pyrrolidine and indoline derivatives was achieved using molecular oxygen as the oxidant. A catalytic NOx species acts as an electron transfer mediator to access a high-valent palladium intermediate as the presumed active oxidant.
October 18, 2016: Organic Letters
Rhian M Touyz
Pathophysiological mechanisms contributing to hypertension include endothelial dysfunction and vascular ignalling. These changes are initially adaptive but chronically become maladaptive leading to vascular damage and loss of function. Common to these processes are changes in the characteristics of vascular cells to a pro-infl ammatory, vasoconstrictory and proliferative phenotype, infl uenced by activation of the RAS and oxidative stress. Increased ROS production and decreased cellular antioxidant defense mechanisms, contribute to oxidative stress, which infl uences redox-sensitive Ang II ignalling that promotes vascular injury in hypertension...
September 2016: Journal of Hypertension
Pierre Paradis, Sofiane Ouerd, Noureddine Idris-Khodja, Michelle Trindade, Suellen C Coelho, Karin A Jandeleit-Dahm, Ernesto L Schiffrin
OBJECTIVE: The prognosis of type-1 diabetes remains poor and is primarily related to the increased risk of vascular complications. Overproduction of reactive oxygen species by NADPH oxidase (NOX) is believed to play an important role in diabetes-related vascular injury. NOX1 may play a role in the macrovascular disease, whereas NOX4 may have protective actions. Nevertheless, their role in diabetic microangiopathy is less well understood. We hypothesized that deletion of Nox1 would prevent diabetes-induced endothelial dysfunction and vascular remodeling of small arteries whereas Nox4 would exaggerate vascular injury...
September 2016: Journal of Hypertension
Adam P Harvey, Augusto Montezano, Khai C Wong, Katie Y Hood, Rheure Alves-Lopes, Graziela S Ceravolo, Chihiro Yabe-Nishimura, Delyth Graham, Rhian M Touyz
OBJECTIVE: In hypertension, the vasculature undergoes alterations that resemble those seen in aging. The involvement of aldosterone and Noxs in the mechanisms underlying age-associated vascular damage is unclear. We postulated that aging-like changes in the vasculature is amplified in hypertension due to increased aldosterone-induced Nox-redox signalling. DESIGN AND METHOD: We assessed vascular aging in arteries from adult WKY (18 weeks), aged WKY (52 weeks) and adult stroke-prone spontaneously hypertensive (SHRSP) rats...
September 2016: Journal of Hypertension
Rhian M Touyz
Pathophysiological mechanisms contributing to hypertension include injury to small arteries, characterised by endothelial dysfunction, vascular remodeling, fibrosis and inflammation, (so called hypertensive vascular phenotype). These changes are initially adaptive but in the long term become maladaptive leading to vascular damage and loss of function, particularly important in small resistance arteries, critically involved in the regulation of peripheral vascular resistance and consequently in blood pressure control...
September 2016: Journal of Hypertension
Jasjeet Bhullar, Veena M Bhopale, Ming Yang, Kinjal Sethuraman, Stephen R Thom
This investigation explored the mechanism for microparticles (MPs) production by human and murine platelets exposed to high pressures of inert gases. Results demonstrate that MPs production occurs via an oxidative stress response in a dose-dependent manner and follows the potency series N2 > Ar > He. Gases with higher van der Waals volumes or polarizability such as SF6 and N2O, or hydrostatic pressure, do not cause MPs production. Singlet O2 is generated by N2, Ar and He, which is linked to NADPH oxidase (NOX) activity...
October 14, 2016: Free Radical Biology & Medicine
Natalia D Magnani, Timoteo Marchini, Mariana Garcés, Andrea Mebert, Lourdes Cáceres, Luis Diaz, Martín Desimone, Pablo A Evelson
Several epidemiological studies have shown a positive correlation between daily increases in airborne particulate matter (PM) concentration and the occurrence of respiratory and cardiovascular diseases. Transition metals present in air PM were associated with adverse health effects after PM exposure. The aim of this work was to study lung O2 metabolism after an acute exposure to transition metal-coated nanoparticles (NPs). Female Swiss mice (25g) were intranasally instilled with a suspension of silica NP containing Ni (II), Cd (II), Fe (III), or Cr (VI) at 0, 0...
October 14, 2016: International Journal of Biochemistry & Cell Biology
Yanqin Ma, Zhenhua Ma, Shuqin Yin, Xiaoyan Yan, Jundong Wang
Excessive amount of inorganic arsenic (iAs) and fluoride (F) coexist in drinking water in many regions, which is associated with high risk of vascular diseases. However, the underlying mechanisms are not well studied. The present study was to evaluate the effects of iAs and F individual or combined exposure on endothelial activation and apoptosis in vitro. Primary human umbilical vein endothelial cells (HUVECs) were exposed to 5 μM As2O3 and/or 1 mM NaF. Changes in endothelial cell apoptosis, inflammation, oxidative stress and nitric oxide (NO) production were analyzed...
October 14, 2016: Chemosphere
Tingting Yue, Fahe Chai, Jingnan Hu, Ming Jia, Xiaofeng Bao, Zhenhua Li, Liqang He, Lei Zu
The natural gas vehicle market is rapidly developing throughout the world, and the majority of such vehicles operate on compressed natural gas (CNG). However, most studies on the emission characteristics of CNG vehicles rely on laboratory chassis dynamometer measurements, which do not accurately represent actual road driving conditions. To further investigate the emission characteristics of CNG vehicles, two CNG city buses and two CNG coaches were tested on public urban roads and highway sections. Our results show that when speeds of 0-10km/hr were increased to 10-20km/hr, the CO2, CO, nitrogen oxide (NOx), and total hydrocarbon (THC) emission factors decreased by (71...
October 2016: Journal of Environmental Sciences (China)
Guiqian Tang, Na Chao, Yuesi Wang, Jiashan Chen
Vehicular emissions in China in 2006 and 2010 were calculated at a high spatial resolution based on the data released by the National Bureau of Statistics, by taking the emission standards into consideration. China's vehicular emissions of carbon monoxide (CO), nitrogen oxides (NOx), volatile organic compounds (VOCs), ammonia (NH3), fine particulate matters (PM2.5), inhalable particulate matters (PM10), black carbon (BC), and organic carbon (OC) were 30,113.9, 4593.7, 6838.0, 20.9, 400.2, 430.5, 285.6, and 105...
October 2016: Journal of Environmental Sciences (China)
Min Zhou, Liping Qiao, Shuhui Zhu, Li Li, Shengrong Lou, Hongli Wang, Qian Wang, Shikang Tao, Cheng Huang, Changhong Chen
In this work, a one-year observation focusing on high time resolution characteristics of components in fine particles was conducted at an urban site in Shanghai. Contributions of different components on visibility impairment were also studied. Our research indicates that the major components of PM2.5 in Shanghai are water-soluble inorganic ions and carbonaceous aerosol, accounting for about 60% and 30% respectively. Higher concentrations of sulfate (SO4(2-)) and organic carbon (OC) in PM2.5 occurred in fall and summer, while higher concentrations of nitrate (NO3(-)) were observed in winter and spring...
October 2016: Journal of Environmental Sciences (China)
Yoshihiro Nakashima, Yoshizumi Kajii
Nitrous acid (HONO) is a well-known source of hydroxyl radicals in the troposphere. Vehicle exhaust is considered to be one of the primary emission sources of HONO. In this study, measurements of HONO in gasoline vehicle exhaust were carried out using a chassis dynamometer combined with incoherent broadband cavity-enhanced absorption spectroscopy. When catalysts were warm, concentrations of HONO were higher than those prior to catalysts warming. Other species, such as CO, and total hydrocarbons (THCs), showed the opposite pattern...
October 12, 2016: Science of the Total Environment
Christa Zollbrecht, A Erik G Persson, Jon O Lundberg, Eddie Weitzberg, Mattias Carlström
BACKGROUND: Inorganic nitrite has shown beneficial effects in cardiovascular and metabolic diseases partly via attenuation of NADPH-oxidase (NOX)-mediated oxidative stress. However, the exact mechanisms are still unclear. Here we investigated the role of S-nitrosation or altered expression of NOX subunits, and the role of xanthine oxidoreductase (XOR) in nitrite-derived nitric oxide (NO) production. METHODS: Mouse macrophages were activated with LPS in the presence or absence of nitrite...
September 28, 2016: Redox Biology
Jim Antturi, Otto Hänninen, Jukka-Pekka Jalkanen, Lasse Johansson, Marje Prank, Mikhail Sofiev, Markku Ollikainen
The maximum allowable fuel sulphur content for shipping in the Baltic Sea dropped from 1%S to 0.1%S in 1 January 2015. We provide a cost-benefit analysis of the sulphur reduction policy in the Baltic Sea Sulphur Emission Control Area (SECA). We calculated the abatement costs based on shipowners' optimal decision-making in choosing between low-sulphur fuel and a sulphur scrubber, and the benefits were modelled through a high-resolution impact pathway analysis, which took into account the formation and dispersion of the emissions, and considered the positive health impacts resulting from lowered ambient PM2...
October 11, 2016: Journal of Environmental Management
Figen Sisman Nayal, Aydin Mammadov, Nilgun Ciliz
While Turkey is one of the world's largest producers and exporters of agricultural goods, it is also, at the same time a net importer of energy carriers. This dichotomy offers a strong incentive to generate energy from agricultural and farming waste; something which could provide energy security for rural areas. Combined with the enhanced energy security for farming areas, the production of energy in this manner could conceivably contribute to the overall national effort to reduce the Turkey's carbon footprint...
October 11, 2016: Journal of Environmental Management
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