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Jitlada Vichapong, Yanawath Santaladchaiyakit, Rodjana Burakham, Supalax Srijaranai
A simple microextraction method, magnetic stirring assisted demulsification dispersive liquid⁻liquid microextraction, for preconcentration of five polycyclic aromatic hydrocarbons (fluorene, phenanthrene, anthracene, fluoranthrene, and pyrene) was investigated prior to analysis by high performance liquid chromatography. In this method, a mixture of extraction solvent and disperser solvent was rapidly injected into sample solution. The magnetic stirrer agitator aided the dispersion of the extraction solvent into the sample solution...
February 13, 2019: Toxics
Suryoday Prodhan, Sumit Mazumdar, S Ramasesha
We report studies of the correlated excited states of coronene and substituted coronene within the Pariser⁻Parr⁻Pople (PPP) correlated π -electron model employing the symmetry-adapted density matrix renormalization group technique. These polynuclear aromatic hydrocarbons can be considered as graphene nanoflakes. We review their electronic structures utilizing a new symmetry adaptation scheme that exploits electron-hole symmetry, spin-inversion symmetry, and end-to-end interchange symmetry. The study of the electronic structures sheds light on the electron correlation effects in these finite-size graphene analogues, which diminishes going from one-dimensional to higher-dimensional systems, yet is significant within these finite graphene derivatives...
February 18, 2019: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
Xin Zhao, Minshu Du, Feng Liu
As the sole metal that could reduce CO₂ to substantial amounts of hydrocarbons, Cu plays an important role in electrochemical CO₂ reduction, despite its low energy efficiency. Surface morphology modification is an effective method to improve its reaction activity and selectivity. Different from the pretreated modification method, in which the catalysts self-reconstruction process was ignored, we present operando synthesis by simultaneous electro-dissolution and electro-redeposition of copper during the CO₂ electroreduction process...
February 17, 2019: Materials
Songul Karakaya, Mehmet Koca, Serdar Volkan Yılmaz, Kadir Yıldırım, Nur Münevver Pınar, Betül Demirci, Marian Brestic, Oksana Sytar
Coumarins and essential oils are the major components of the Apiaceae family and the Zosima genus. The present study reports anticholinesterase and antioxidant activities of extracts and essential oils from aerial parts, roots, flowers, fruits and coumarins-bergapten ( 1 ); imperatorin ( 2 ), pimpinellin ( 3 ) and umbelliferone ( 4 )-isolated of the roots from Zosima absinthifolia . The investigation by light and scanning electron microscopy of the structures of secretory canals found different chemical compositions in the various types of secretory canals which present in the aerial parts, fruits and flowers...
February 17, 2019: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
Karl Walter Bock
Diverse physiologic functions of AHR, a transcription factor discovered in studies of dioxin toxicity, are currently elucidated in many laboratories including chemical and microbial defense, immunity and myelopoiesis. Accumulating evidence suggests that AHR may also be involved in obesity and TCDD-mediated lethality in sensitive species. Underlying mechanisms include NAD+ - and sirtuin-mediated deregulation of lipid, glucose and NAD+ homeostasis. Progress in NAD metabolome research suggests large consumption of NAD+ by NAD glycohydrolases (NADases) and NAD-dependent sirtuins...
February 16, 2019: Biochemical Pharmacology
Sergei Sergeevich Bystrov, Vladimir Victorovich Matveev, Yuri S Chernyshev, Vytautas Balevicius, Vladimir Ivanovich Chizhik
The detailed investigation of the local mobility in a set of dried imidazolium-based ionic liquids (1-butyl-3-methylimidazolium) in a wide temperature range and varying anions (BF<sub>4</sub>-, I-, Cl-, Br-, NO<sub>3</sub>-, TfO-) is presented. The measurements of temperature dependencies of the spin-lattice relaxation times of <sup>1</sup>H and <sup>13</sup>C nuclei are motivated by the need to obtain a fundamental characterization of molecular mobility of the substances under study, namely, to estimate the correlation times, τ</sub>c<sub>, for the motion of individual molecular groups...
February 19, 2019: Journal of Physical Chemistry. B
Keivan Mobini, Gholamhossein Tamaddon, Reza Fardid, Majid Keshavarzi, Afshin Mohammadi-Bardbori
The underlying functions of miR-206, miR-133a, miR-27b, and miR-21, and their link to the estrogen receptor alpha (ERα) and aryl hydrocarbon receptor (AhR) signaling pathways remain largely unexplored. In this study, we detect the expression of miR-206, miR-133a, miR-27b, and miR-21 in MCF-7 through quantificational real-time polymerase chain reaction assay along with the activation/inhibition of ERα and AhR receptors. Aside from this, cell proliferation and migration as well as AhR-dependent CYP1A1 enzyme activity were measured...
February 19, 2019: Journal of Biochemical and Molecular Toxicology
Yuan-Yuei Chen, Tung-Wei Kao, Chung-Ching Wang, Ying-Jen Chen, Chen-Jung Wu, Ching-Huang Lai, Wei-Liang Chen
Polycyclic aromatic hydrocarbons (PAHs) are environmental pollutants. Exposure to PAHs is associated with several adverse health outcomes. However, no previous study has examined the relationship between PAH exposure and functional dependence in an elderly population. Our aim was to examine whether PAH exposure was associated with functional dependence including total disability, activities of daily living (ADL), instrumental activities of daily living (IADL), leisure and social activities (LSA), lower extremity mobility (LEM), and general physical activities (GPA) in an elderly population...
February 18, 2019: Environmental Science and Pollution Research International
Yuvarajan Devarajan, Beemkumar Nagappan, Ganesan Subbiah
The present work is aimed to analyze the performance and emission characteristics of mahua biodiesel-fueled diesel engine with copper oxide nanoparticle at various particle sizes (10 and 20 nm) and the results compared with conventional diesel fuel (BD). Experiments were conducted in a four-stroke, single-cylinder, constant speed, and naturally aspirated research diesel engine with an eddy current dynamometer. Conventional transesterification process is carried out to convert the raw mahua oil into mahua oil biodiesel (BD100)...
February 18, 2019: Environmental Science and Pollution Research International
Grzegorz Przydatek, Włodzimierz Kanownik
The aim of this paper is to analyse changes in the physicochemical elements in groundwater in the vicinity of a small municipal solid waste landfill site located within the territory of the European Union on the basis of 7-year hydrochemical research. Samples of groundwater and leachate near the examined landfill were collected four times a year during two periods, between 2008 and 2012 during the use of the landfill and between 2013 and 2014 at the stage of its closure. The research results were analysed on the basis of general physicochemical properties: pH; total organic carbon (TOC); electrical conductivity (EC); inorganic elements: Cr, Zn, Cd, Cu, Pb, Hg; and one organic element-polycyclic aromatic hydrocarbon (PAH)...
February 19, 2019: Environmental Monitoring and Assessment
Vincenzo Dinallo, Irene Marafini, Davide Di Fusco, Antonio Di Grazia, Federica Laudisi, Rami Dwairi, Omero A Paoluzi, Giovanni Monteleone, Ivan Monteleone
Aryl hydrocarbon receptor (AhR), a transcription factor activated by a large number of natural and synthetic agents, modulates the activity of immune cells in the gut and represents an important link between the environment and immune-mediated pathologies. In this study, we investigated the role of AhR in celiac disease (CD), a gluten-driven enteropathy. AhR expression was evaluated in intestinal biopsies taken from patients with CD and controls by real-time polymerase chain reaction (PCR), immunohistochemistry and flow cytometry...
2019: Frontiers in Immunology
Masoud Talebi Amiri, Graham R Dick, Ydna M Questell-Santiago, Jeremy S Luterbacher
Lignin is one of the most promising sources of renewable aromatic hydrocarbons. Current methods for its extraction from lignocellulosic biomass-which include the kraft, sulfite, and organosolv processes-result in the rapid formation of carbon-carbon bonds, leading to a condensed lignin that cannot be effectively depolymerized into its constituent monomers. Treatment of lignocellulosic biomass with aldehydes during lignin extraction generates an aldehyde-stabilized lignin that is uncondensed and can be converted into its monomers at near-theoretical yields...
February 18, 2019: Nature Protocols
K H Caesar, J R Kyle, T W Lyons, A Tripati, S J Loyd
Major hydrocarbon accumulations occur in traps associated with salt domes. Whereas some of these hydrocarbons remain to be extracted for economic use, significant amounts have degraded in the subsurface, yielding mineral precipitates as byproducts. Salt domes of the Gulf of Mexico Basin typically exhibit extensive deposits of carbonate that form as cap rock atop salt structures. Despite previous efforts to model cap rock formation, the details of subsurface reactions (including the role of microorganisms) remain largely unknown...
February 18, 2019: Nature Communications
Troy D Hubbard, Qing Liu, Iain A Murray, Fangcong Dong, Charles Miller Iii, Phillip B Smith, Krishne Gowda, Jyh Ming Lin, Shantu Amin, Andrew D Patterson, Gary H Perdew
The Aryl hydrocarbon receptor (AHR) is a major regulator of immune function within the gastrointestinal tract. Resident microbiota are capable influencing AHR-dependent signaling pathways via production of an array of bioactive molecules that act as AHR agonists, such as indole or indole-3-aldehyde. Bacteria produce a number of quinoline derivatives, of which some function as quorum-sensing molecules. Thus, we screened relevant hydroxyquinoline derivatives for AHR activity using AHR responsive reporter cell lines...
February 19, 2019: Journal of Proteome Research
Katherine L Hull, Amy J Cairns, Marium Haq
A redox chemistry approach has been employed to synthesize an assortment of acids in the subterranean environment for the purpose of enhancing productivity from hydrocarbon-bearing rock formations. Experimental studies revealed that bromate selectively oxidizes a series of ammonium salts NH4 X where X = F- , Cl- , Br- , SO4 2- , and CF3 CO2 - to produce 5-17 wt % HX. Importantly, the in situ method allows strategic placement of the acid in the zone of interest where the fluid is heated, and the reaction is triggered...
February 19, 2019: Inorganic Chemistry
Samir S Radwan, Majida M Khanafer, Husain A Al-Awadhi
BACKGROUND: The group of the so-called obligate hydrocarbonoclastic bacteria (OHCB) are marine microorganisms affiliated with the genera Alcanivorax, Cycloclasticus, Oleiphilus and Thalassolituus. This small group plays a major role in oil-bioremediation in marine ecosystems. Marinobacter and Planomicrobium are considered related to this group. The OHCB are claimed to be obligate to hydrocarbon nutrition. This study argues against this claim. RESULTS: Four Alcanivorax species, three Marinobacter species and Planomicrobium okeanokoites from the Arabian/Persian Gulf proved to be not obligate to hydrocarbon nutrition...
February 18, 2019: BMC Microbiology
Hongling Liu, Laihao Shi, John P Giesy, Hongxia Yu
Polychlorinated diphenyl sulfides (PCDPSs) are a group of chemicals that can interact and activate the aryl hydrocarbon receptor (AhR). Previous studies have shown that PCDPSs can cause oxidative stress in livers. However, information on genotoxicity of PCDPSs is limited. In this study, it is hypothesized that PCDPSs can produce reactive oxygen species (ROS) by activating the AhR and inducing expression of CYP1A1, which subsequently causes genotoxicity. HepG2 cells (transfected with AhR and CYP1A1 siRNA or not) were exposed to six PCDPSs...
February 1, 2019: Chemosphere
Jana Růžičková, Marek Kucbel, Helena Raclavská, Barbora Švédová, Konstantin Raclavský, Dagmar Juchelková
The combustion of biomass in boilers of emission classes 2 and 3 produces deposits in the form of char and soot inside the combustion chamber. Char and soot differ in content of elemental carbon (EC) and organic carbon (OC) as well as in the content of organic compounds. Deposits from boilers of emission class 2 contain higher amounts of OC and EC than those from boilers of emission class 3. The only exception is deposits formed by the combustion of briquettes from hardwood in boilers of emission class 3 that contained approximately by up to 60 percent higher amount of OC and by approx...
February 15, 2019: Journal of Environmental Management
Jihong Wang, Jingxiu Zhang, Xiangguo Sun, Chengjun Liu, Xingli Li, Lei Chen
The respiratory syncytial virus fusion (RSV-F) protein is a primary target for vaccine and drug development against respiratory infection and pediatric pneumonia. The RSV-F core forms a trimer-of-hairpins (TOH) motif in post-fusion conformation, which is characterized by a six-helix bundle (6HB) where the three N-terminal HRn helices define a central coiled-coil, while three C-terminal HRc helices pack on the coiled-coil surface in an antiparallel manner. Here, one tightly packed HRn-HRc helix-helix interaction is stripped from the 6HB, which represents the minimum unit of RSV-F TOH motif...
February 18, 2019: Chemical Biology & Drug Design
M C Gryka, T J Comi, R A Forsyth, P M Hadley, S Deb, R Bhargava
Freeform 3D printing combined with sacrificial molding promises to lead advances in production of highly complex tubular systems for biomedical applications. Here we leverage a purpose-built isomalt 3D printer to generate complex channel geometries in hydrogels which would be inaccessible with other techniques. To control the dissolution of the scaffold, we propose an enabling technology consisting of an automated nebulizer coating system which applies octadecane to isomalt scaffolds. Octadecane, a saturated hydrocarbon, protects the rigid mold from dissolution and provides ample time for gels to set around the sacrificial structure...
March 2019: Additive Manufacturing
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