Read by QxMD icon Read

Atmospheric composition

Yinhong Hu, Xiaolin Dou, Juanyong Li, Feng Li
The rapid expansion of urbanization has caused land cover change, especially the increasing area of impervious surfaces. Such alterations have significant effects on the soil ecosystem by impeding the exchange of gasses, water, and materials between soil and the atmosphere. It is unclear whether impervious surfaces have any effects on soil bacterial diversity and community composition. In the present study, we conducted an investigation of bacterial communities across five typical land cover types, including impervious surfaces (concrete), permeable pavement (bricks with round holes), shrub coverage ( Buxus megistophylla Levl...
2018: Frontiers in Microbiology
Irena F Creed, Ann-Kristin Bergström, Charles G Trick, Nancy B Grimm, Dag O Hessen, Jan Karlsson, Karen A Kidd, Emma Kritzberg, Diane M McKnight, Erika C Freeman, Oscar E Senar, Agneta Andersson, Jenny Ask, Martin Berggren, Mehdi Cherif, Reiner Giesler, Erin R Hotchkiss, Pirkko Kortelainen, Monica M Palta, Tobias Vrede, Gesa A Weyhenmeyer
Northern ecosystems are experiencing some of the most dramatic impacts of global change on Earth. Rising temperatures, hydrological intensification, changes in atmospheric acid deposition and associated acidification recovery, and changes in vegetative cover are resulting in fundamental changes in terrestrial-aquatic biogeochemical linkages. The effects of global change are readily observed in alterations in the supply of dissolved organic matter (DOM) - the messenger between terrestrial and lake ecosystems - with potentially profound effects on the structure and function of lakes...
March 15, 2018: Global Change Biology
Zhishun He, Kai Wang, Shasha Zhu, Liang-Ai Huang, Miaomiao Chen, Jianfeng Guo, Shien Pei, Haibo Shao, Jianming Wang
Hierarchically nanostructured binary/multiple transition metal oxides with electrically conductive coatings are very attractive for lithium-ion batteries (LIBs) owing to their excellent electrochemical properties induced by their unique compositions and microstructures. Herein, hierarchical MnO doped Fe3O4@C composite nanospheres are prepared by a simple one-step annealing in Ar atmosphere, using Mn-doped Fe-based metal organic frameworks (Mn-doped MIL-53(Fe)) as precursor. The MnO doped Fe3O4@C composite particles have a uniform nanosphere structure with a diameter of ~100 nm, and each nanosphere is composed of clustered primary nanoparticles with an amorphous carbon shell, forming a unique hierarchical nanoarchitecture...
March 14, 2018: ACS Applied Materials & Interfaces
Michael Tchirikov, Erich Saling, Gauri Bapayeva, Michael Bucher, Oliver Thews, Gregor Seliger
In the first case, the AA and glucose were infused through a perinatal port system into the umbilical vein at 30 weeks' gestation due to severe IUGR. The patient received daily hyperbaric oxygenation (HBO, 100% O2 ) with 1.4 atmospheres absolute for 50 min for 7 days. At 31+4  weeks' gestation, the patient gave birth spontaneously to a newborn weighing 1378 g, pH 7.33, APGAR score 4/6/intubation. In follow-up examinations at 5 years of age, the boy was doing well without any neurological disturbance or developmental delay...
March 2018: Physiological Reports
Valeri Petkov, Yazan Maswadeh, Aolin Lu, Shiyao Shan, Haval Kareem, Yinguang Zhao, Jin Luo, Chuan-Jian Zhong, Kevin Beyer, Karena W Chapman
We present results from combined in situ infrared spectroscopy and total x-ray scattering studies on the evolution of catalytically active sites in exemplary binary and ternary Pt-based nanoalloys during a sequence of CO oxidation-reactivation-CO oxidation reactions. We find that, when within a particular compositional range, the fresh nanoalloys may exhibit high catalytic activity for low-temperature CO oxidation. Using surface-specific atomic pair distribution functions (PDFs) extracted from the in situ total x-ray scattering data we find that, regardless their chemical composition and initial catalytic activity, the fresh nanoalloys suffer a significant surface structural disorder during CO oxidation...
March 13, 2018: ACS Applied Materials & Interfaces
Kun Li, Junling Li, Weigang Wang, Jiangjun Li, Chao Peng, Dong Wang, Maofa Ge
The formation of secondary organic aerosol (SOA) contains partitioning processes of the oxidation products between gas and particle phase, which could change the particle-phase composition when particles grow. However, the effects of these processes on the optical properties of SOA remain poorly understood. In this study, we performed smog chamber experiments to investigate the effects of gas-particle partitioning (GPP) on the refractive index (RI) and chemical composition of the m-xylene SOA. Here, we show that the GPP processes, as organic mass increases, can increase the proportions of semi- and intermediate volatile organic compounds (SVOCs and IVOCs) in the particle phase and result in the decrease of SOA RI real part for 0...
March 12, 2018: Journal of Physical Chemistry. A
Megan Suzanne Claflin, Paul J Ziemann
Substantial amounts of gas- and particle-phase organic nitrates have been reported in field studies of atmospheric chemistry conducted around the world, and it has been proposed that a significant fraction of these may be formed from the nighttime reaction of monoterpenes with NO3 radicals. In the study presented here, β-pinene (a major global monoterpene emission) was reacted with NO3 radicals in an environmental chamber and the molecular and functional group composition of the resulting secondary organic aerosol (SOA) was determined using a variety of methods...
March 12, 2018: Journal of Physical Chemistry. A
Na Li, Deli Lu, Jinlong Zhang, Lingzhi Wang
Yolk-shell structured C@Li4 Ti5 O12 microspheres composed of carbon core (ca. 500 nm) and sea urchin-like Li4 Ti5 O12 shell (ca. 400-500 nm) are formed by hydrothermally treating the core-shell structured C@TiO2 in the EtOH/H2 O solution of LiOH and calcining it in N2 atmosphere. Yolk-shell structured TiO2 -type lithium ion sieve is further transformed from C@Li4 Ti5 O12 through the acid treatment, which have a high specific surface area of 201.74 m2 /g. The composite shows adsorption capacity towards Li+ proportional to the pH value in the range of 7-13...
February 10, 2018: Journal of Colloid and Interface Science
Jason C Marvin, Silvia I Gallegos, Shaida Parsaei, Danieli C Rodrigues
PURPOSE: To evaluate the biocompatibility of five dental cement compositions after directly exposing human gingival fibroblast (HGF) and MC3T3-E1 preosteoblast cells to cement alone and cement applied on commercially pure titanium (cpTi) specimens. MATERIALS AND METHODS: Nanostructurally integrated bioceramic (NIB), resin (R), resin-modified glass ionomer (RMGIC), zinc oxide eugenol (ZOE), and zinc phosphate (ZP) compositions were prepared according to the respective manufacturer's instructions...
March 9, 2018: Journal of Prosthodontics: Official Journal of the American College of Prosthodontists
Afshin Beheshti, Egle Cekanaviciute, David J Smith, Sylvain V Costes
Spaceflight introduces a combination of environmental stressors, including microgravity, ionizing radiation, changes in diet and altered atmospheric gas composition. In order to understand the impact of each environmental component on astronauts it is important to investigate potential influences in isolation. Rodent spaceflight experiments involve both standard vivarium cages and animal enclosure modules (AEMs), which are cages used to house rodents in spaceflight. Ground control AEMs are engineered to match the spaceflight environment...
March 8, 2018: Scientific Reports
Samah Y Mohamed, Alexander Cory Davis, Mariam J Al Rashidi, S Mani Sarathy
Hydroperoxyalkylperoxy (OOQOOH) radical isomerization is an important low-temperature chain branching reaction within the mechanism of hydrocarbon oxidation. This isomerization may proceed via the migration of the α-hydrogen to the hydroperoxide group. In this work, a combination of high level composite methods - CBS-QB3, G3 and G4 - is used to determine the high-pressure-limit rate parameters for the title reaction. Rate rules for H-migration reactions proceeding through 5-, 6-, 7- and 8-membered ring transitions states are determined...
March 8, 2018: Journal of Physical Chemistry. A
T Guillot, Y Miguel, B Militzer, W B Hubbard, Y Kaspi, E Galanti, H Cao, R Helled, S M Wahl, L Iess, W M Folkner, D J Stevenson, J I Lunine, D R Reese, A Biekman, M Parisi, D Durante, J E P Connerney, S M Levin, S J Bolton
Jupiter's atmosphere is rotating differentially, with zones and belts rotating at speeds that differ by up to 100 metres per second. Whether this is also true of the gas giant's interior has been unknown, limiting our ability to probe the structure and composition of the planet. The discovery by the Juno spacecraft that Jupiter's gravity field is north-south asymmetric and the determination of its non-zero odd gravitational harmonics J3 , J5 , J7 and J9 demonstrates that the observed zonal cloud flow must persist to a depth of about 3,000 kilometres from the cloud tops...
March 7, 2018: Nature
Xin Li, Xiaohong Sun, Zhiwen Gao, Xudong Hu, Rui Ling, Shu Cai, Chunming Zheng, Wenbin Hu
SnS2/graphene composites have attracted extensive attention in energy storage due to their excellent electrochemical performance. However, most of the previous methods to synthesize SnS2/graphene composites require long time, high temperature, or high pressure, which are obstacles for practical low-cost production. Herein, we reported a simple one-pot strategy to prepare SnS2/graphene composites, which is not time consuming (1 h) and requires moderate-temperature (75 °C) in atmosphere. Through this method, ultrafine SnS2 nanoparticles anchored on graphene nanosheets have been successfully prepared and achieved excellent electrochemical performance for both lithium/sodium storage...
March 8, 2018: ChemSusChem
Bitopan Sarma, Pranab Ram Bhattacharyya, Mantu Bhuyan
Apart from other pollutants, flaring of natural gas adds carbon dioxide into the environment and changes the atmospheric composition, including temperature and humidity. As a major gaseous product, carbon dioxide changes plant structural components as well as herbivores, i.e., insect by dilution of nitrogen under such circumstances. Present analysis demonstrated the impact of gas flaring upon adjoining biota especially Eurema hecabe butterfly and its host plant, Cassia tora in some wells (group gathering stations) of Assam, India...
March 7, 2018: Environmental Science and Pollution Research International
Saideh Ghadimi, Giti Forghani, Gholam Abbas Kazemi
The Angouran Mine, located in northwest Iran, is the largest Zn-Pb producer in the Middle East. This study was designed to investigate the distribution, geochemistry, and mineralogy of the aerosols in the mining area and to assess their likely health impacts on the local residents. For this purpose, 36 aerosol samples were collected from 2014 to 2015 at nine sites located in mine district and upwind and downwind directions. The concentration of potentially toxic elements in the aerosols was determined using AAS instrument...
March 7, 2018: Environmental Geochemistry and Health
Jonathan P Reid, Allan K Bertram, David O Topping, Alexander Laskin, Scot T Martin, Markus D Petters, Francis D Pope, Grazia Rovelli
The importance of organic aerosol particles in the environment has been long established, influencing cloud formation and lifetime, absorbing and scattering sunlight, affecting atmospheric composition and impacting on human health. Conventionally, ambient organic particles were considered to exist as liquids. Recent observations in field measurements and studies in the laboratory suggest that they may instead exist as highly viscous semi-solids or amorphous glassy solids under certain conditions, with important implications for atmospheric chemistry, climate and air quality...
March 6, 2018: Nature Communications
David V Bekaert, Michael W Broadley, Frédéric Delarue, Guillaume Avice, Francois Robert, Bernard Marty
Understanding the composition of the Archean atmosphere is vital for unraveling the origin of volatiles and the environmental conditions that led to the development of life. The isotopic composition of xenon in the Archean atmosphere has evolved through time by mass-dependent fractionation from a precursor comprising cometary and solar/chondritic contributions (referred to as U-Xe). Evaluating the composition of the Archean atmosphere is challenging because limited amounts of atmospheric gas are trapped within minerals during their formation...
February 2018: Science Advances
Sanchita Biswas Murmu, Hari Niwas Mishra
In modified atmosphere packaging of guava, moisture scavenger (MS) sachet containing 30-50 g of coarse silica gel and ethylene scavenger (ES) sachet containing 0-4 g of potassium permanganate was added as per central composite rotatable design. The headspace O2 and CO2 of the packages were studied at 4, 8 and 12 °C for 30 days and thereafter the guava were left for two days to ripen at 30 °C. After that the chilling injuries, percentage acceptable guava, peel color and pulp texture was analyzed...
July 1, 2018: Food Chemistry
Pavel Ryumin, Rainer Cramer
New liquid atmospheric pressure (AP) matrix-assisted laser desorption/ionization (MALDI) matrices that produce predominantly multiply charged ions have been developed and evaluated with respect to their performance for peptide and protein analysis by mass spectrometry (MS). Both the chromophore and the viscous support liquid in these matrices were optimized for highest MS signal intensity, S/N values and maximum charge state. The best performance in both protein and peptide analysis was achieved employing light diols as matrix support liquids (e...
July 12, 2018: Analytica Chimica Acta
Yulong Liu, Jian Liu, Jiajun Wang, Mohammad Norouzi Banis, Biwei Xiao, Andrew Lushington, Wei Xiao, Ruying Li, Tsun-Kong Sham, Guoxian Liang, Xueliang Sun
Carbon coating is a commonly employed technique for improving the conductivity of active materials in lithium ion batteries. The carbon coating process involves pyrolysis of organic substance on lithium iron phosphate particles at elevated temperature to create a highly reducing atmosphere. This may trigger the formation of secondary phases in the active materials. Here, we observe a conductive phase during the carbon coating process of lithium iron phosphate and the phase content is size, temperature, and annealing atmosphere dependent...
March 2, 2018: Nature Communications
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"