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https://www.readbyqxmd.com/read/28641403/a-molasses-habitat-derived-fungus-aspergillus-tubingensis-xg21-with-high-%C3%AE-fructofuranosidase-activity-and-its-potential-use-for-fructooligosaccharides-production
#1
Yijia Xie, Huanxia Zhou, Caixia Liu, Jing Zhang, Ning Li, Zhanli Zhao, Guoyong Sun, Yaohua Zhong
The industrial microorganisms used for fructooligosaccharides (FOS) synthesis are generally fermented with sucrose as carbon source to induce the production of β-fructofuranosidase (FFase) having transfructosylation activity. Consequently, isolation of novel FFase producers from a sucrose-enriched biotope would help improve FOS productivity and reduce the process cost. Here, three fungi isolated from a unique sugarcane molasses habitat were found to possess FFase activity and one of them, XG21, exhibited a high capacity to synthesize FOS...
December 2017: AMB Express
https://www.readbyqxmd.com/read/28641319/understanding-scuba-diving-fatalities-carbon-dioxide-concentrations-in-intra-cardiac-gas
#2
Vincent Varlet, Alejandro Dominguez, Marc Augsburger, Maisy Lossois, Coraline Egger, Cristian Palmiere, Raquel Vilarino, Silke Grabherr
INTRODUCTION: Important developments in the diagnosis of scuba diving fatalities have been made thanks to forensic imaging tool improvements. Multi-detector computed tomography (MDCT) permits reliable interpretation of the overall gaseous distribution in the cadaver. However, due to post-mortem delay, the radiological interpretation is often doubtful because the distinction between gas related to the dive and post-mortem decomposition artifactual gases becomes less obvious. METHODS: We present six cases of fatal scuba diving showing gas in the heart and other vasculature...
June 2017: Diving and Hyperbaric Medicine: the Journal of the South Pacific Underwater Medicine Society
https://www.readbyqxmd.com/read/28641276/atherosclerosis-and-the-hydrogen-sulfide-signaling-pathway-therapeutic-approaches-to-disease-prevention
#3
Zhi-Jun Wang, Jian Wu, Wei Guo, Yi-Zhun Zhu
Hydrogen sulfide (H2S) is now admitted as a third gasotransmitter together with nitric oxide (NO) and carbon monoxide (CO), albeit it was originally considered as a foul and poisonous gas. Endogenous H2S production in mammalian cells is counting on the three enzymes acting on cysteine. Involvement of H2S in various physiological and pathological processes has been extensively studied in the last fifteen years. Mounting evidence suggests that H2S is able to protect against atherosclerosis development and progression...
June 23, 2017: Cellular Physiology and Biochemistry
https://www.readbyqxmd.com/read/28641229/effects-of-short-term-invasion-of-spartina-alterniflora-and-the-subsequent-restoration-of-native-mangroves-on-the-soil-organic-carbon-nitrogen-and-phosphorus-stock
#4
Jianxiang Feng, Jian Zhou, Liming Wang, Xiaowei Cui, Cunxin Ning, Hao Wu, Xiaoshan Zhu, Guanghui Lin
The exotic cordgrass Spartina alterniflora has severely invaded the mangrove wetlands in southern China and ecological restoration using native mangroves was conducted in an attempt to control this invasive species. In this study, the contents and pools of soil organic carbon (SOC), total nitrogen (TN) and total phosphorus (TP) were quantified to investigate the invasive effects of S. alterniflora and then to evaluate whether the ecological restoration of native mangrove could reverse those effects. S. alterniflora only showed significantly higher organic carbon content in the surface 0-10 cm of soil than in the uninvaded mudflat...
June 15, 2017: Chemosphere
https://www.readbyqxmd.com/read/28641225/investigation-of-dissociation-constants-for-individual-and-total-naphthenic-acids-species-using-ultra-performance-liquid-chromatography-ion-mobility-time-of-flight-mass-spectrometry-analysis
#5
Rongfu Huang, Pamela Chelme-Ayala, Yanyan Zhang, Mohamed Changalov, Mohamed Gamal El-Din
Ultra-performance liquid chromatography ion mobility time-of-flight mass spectrometry (UPLC-IM-TOFMS) was utilized for the analysis of naphthenic acids (NAs) in fractions of pH-dependent sequential liquid-liquid extractions from oil sands process-affected water. Ion-mobility separation technique allowed the differentiation of OyS-NAs (2 ≤ y ≤ 4) from Ox-NAs (2 ≤ x ≤ 5) via drift time versus retention time separations. The results indicated that the addition of S atom to the O2-NA molecule led to a lower increase in the dissociation constant (pKa) compared to that caused by the addition of O atom...
June 18, 2017: Chemosphere
https://www.readbyqxmd.com/read/28641206/efficacy-of-surgical-laser-therapy-in-the-management-of-oral-pigmented-lesions-a-systematic-review
#6
Tariq Abduljabbar, Fahim Vohra, Zohaib Akram, Siti Mariam Ab Ghani, Nawwaf Al-Hamoudi, Fawad Javed
BACKGROUND: Oral pigmentation, especially in the gingiva poses esthetic problems. Laser therapy has been widely used for cosmetic therapy in dentistry. The aim of the present study was to systematically review the efficacy of surgical laser therapy (SLT) in the management of oral pigmented lesions (OPL). MATERIALS AND METHODS: The addressed focused question was "Is SLT effective in the management of OPL?" Databases (MEDLINE via PubMed; EMBASE; Cochrane Central Register of Controlled Trials and Cochrane Oral Health Group Trials Register databases) were searched from 1970 up to and including February 2017...
June 15, 2017: Journal of Photochemistry and Photobiology. B, Biology
https://www.readbyqxmd.com/read/28641011/exploiting-one-dimensional-exciton-phonon-coupling-for-tunable-and-efficient-single-photon-generation-with-a-carbon-nanotube
#7
Adrien Jeantet, Yannick Chassagneux, Théo Claude, Philippe Roussignol, Jean-Sébastien Lauret, Jakob Reichel, Christophe Voisin
Condensed-matter emitters offer enriched cavity quantum electrodynamical effects due to the coupling to external degrees of freedom. In the case of carbon nanotubes a very peculiar coupling between localized excitons and the one-dimensional acoustic phonon modes can be achieved, which gives rise to pronounced phonon wings in the luminescence spectrum. By coupling an individual nanotube to a tunable optical micro-cavity, we show that this peculiar exciton-phonon coupling is a valuable resource to enlarge the tuning range of the single-photon source while keeping an excellent exciton-photon coupling efficiency and spectral purity...
June 22, 2017: Nano Letters
https://www.readbyqxmd.com/read/28640994/promotion-of-electrocatalytic-hydrogen-evolution-reaction-on-nitrogen-doped-carbon-nanosheets-with-secondary-heteroatoms
#8
Konggang Qu, Yao Zheng, Xianxi Zhang, Ken Davey, Sheng Dai, Shi Zhang Qiao
Dual heteroatom-doped carbon materials are efficient electrocatalysts via a synergistic effect. With nitrogen as the primary dopant, boron, sulfur and phosphorus can be used as secondary elements for co-doped carbons. However, evaluation and analysis of the promotional effect of B, P and S to N-doped carbons has not been widely researched. Here we report a robust platform that is constructed through polydopamine (PDA) to prepare N, B-, N, P- and N, S-co-doped carbon nanosheets, characterized by similar N species content and efficient B, P and S doping...
June 22, 2017: ACS Nano
https://www.readbyqxmd.com/read/28640943/dimensioning-the-term-carbenoid
#9
Pedro J Pérez, Ana Caballero
The current use of the term carbenoid is discussed, particularly in the context of carbene transfer reactions from diazo compounds, where intermediates of type LnM=CR1R2, or one of its resonance forms, are tagged which such name. We herein discuss this issue, on the basis of the data evidencing the metal-carbene nature of those intermediates, as well as the existence of carbenoids of type (N2)(M)C R1R2 en route to the formation to LnM=C R1R2' from diazo reagents. We propose the exclusive use of the carbenoid term to species of type (X)(M)C R1R2 with a tetrasubstituted carbon center that upon loss of X afford an effective carbene transfer process...
June 22, 2017: Chemistry: a European Journal
https://www.readbyqxmd.com/read/28640841/a-sorghum-sorghum-bicolor-mutant-with-altered-carbon-isotope-ratio
#10
Govinda Rizal, Shanta Karki, Vivek Thakur, Samart Wanchana, Hugo Alonso-Cantabrana, Jacque Dionora, John E Sheehy, Robert Furbank, Susanne von Caemmerer, William Paul Quick
Recent efforts to engineer C4 photosynthetic traits into C3 plants such as rice demand an understanding of the genetic elements that enable C4 plants to outperform C3 plants. As a part of the C4 Rice Consortium's efforts to identify genes needed to support C4 photosynthesis, EMS mutagenized sorghum populations were generated and screened to identify genes that cause a loss of C4 function. Stable carbon isotope ratio (δ13C) of leaf dry matter has been used to distinguishspecies with C3 and C4 photosynthetic pathways...
2017: PloS One
https://www.readbyqxmd.com/read/28640743/glucose-consumption-in-carbohydrate-mixtures-by-phosphotransferase-system-mutants-of-escherichia-coli
#11
Tian Xia, Neeraj Sriram, Sarah A Lee, Ronni Altman, Jeffrey L Urbauer, Elliot Altman, Mark A Eiteman
Escherichia coli lacking the glucose phosphotransferase system (PTS), mannose PTS and glucokinase are supposedly unable to grow on glucose as the sole carbon source (Curtis SJ, Epstein W. J Bacteriol 1975;122:1189-1199). We report that W ptsG manZ glk (ALS1406) grows slowly on glucose in media containing glucose with a second carbon source: ALS1406 metabolizes glucose after that other carbon source, including arabinose, fructose, glycerol, succinate or xylose, is exhausted. Galactose is an exception to this rule, as ALS1406 simultaneously consumes both galactose and glucose...
June 22, 2017: Microbiology
https://www.readbyqxmd.com/read/28640639/alkaline-earth-centered-co-homologation-reduction-and-amine-carbonylation
#12
Mathew D Anker, Christos E Kefalidis, Yan Yang, Jian Fang, Michael S Hill, Mary F Mahon, Laurent Maron
Reactions of -diketiminato magnesium and calcium hydrides with 1 atmosphere of CO result in a reductive coupling process to produce the corresponding derivatives of the cis-ethenediolate dianion. Computational (DFT) analysis of this processes mediated by Ca, Sr and Ba highlight a common mechanism and a facility for the reaction that increases with increasing alkaline earth (Ae) atomic weight. Reaction of CO with PhSiH3 in the presence of the magnesium or calcium hydrides results in catalytic reduction to methylsilane and methylene silylether products respectively...
June 22, 2017: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/28640625/dust-effects-on-nucleation-kinetics-and-nanoparticle-product-size-distributions-illustrative-case-study-of-a-prototype-ir-0-n-transition-metal-nanoparticle-formation-system
#13
Saim Özkar, Richard G Finke
The question is addressed if dust is kinetically important in the nucleation and growth of Ir(0)n nanoparticles formed from [Bu4N]5Na3(1,5-COD)Ir(I)·P2W15Nb3O62 (hereafter [(COD)Ir·POM](8-)), reduced by H2 in propylene carbonate solvent. Following a concise review of the (often-neglected) literature addressing dust in nucleation phenomena dating back to the late 1800s, the nucleation and growth kinetics of the [(COD)Ir·POM](8-) precatalyst system are examined for the effects of 0.2 μm microfiltration of the solvent and precatalyst solution, of rinsing the glassware with that microfiltered solvent, of silanizing the glass reaction vessel, for the addition of <0...
June 22, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
https://www.readbyqxmd.com/read/28640617/5-methylhydantoin-from-isolated-molecules-in-a-low-temperature-argon-matrix-to-solid-state-polymorphs-characterization
#14
Bernardo A Nogueira, Gulce O Ildiz, João Canotilho, M Ermelinda S Eusébio, Marta Sofia C Henriques, José A Paixão, Rui Fausto
The molecular structure, vibrational spectra and photochemistry of 5-methylhydantoin (C4H6N2O2; 5-MH) were studied by matrix isolation infrared spectroscopy and theoretical calculations at the DFT(B3LYP)/6-311++G(d,p) theory level. The Natural Bond Orbital (NBO) analysis approach was used to study in detail the electronic structure of the minimum energy structure of 5-MH, namely the specific characteristics of the σ and π electronic systems of the molecule, and the stabilizing orbital interactions. UV irradiation of 5-MH isolated in argon matrix resulted in its photofragmentation through a single photochemical pathway, yielding isocyanic acid, ethanimine and carbon monoxide, thus following a pattern already observed before for the parent hydantoin and 1-methylhydantoin molecules...
June 22, 2017: Journal of Physical Chemistry. A
https://www.readbyqxmd.com/read/28640603/changes-in-light-absorptivity-of-molecular-weight-separated-brown-carbon-due-to-photolytic-aging
#15
Jenny Pui Shan Wong, Athanasios Nenes, Rodney J Weber
Brown carbon (BrC) are those organic compounds in atmospheric aerosols that absorb solar radiation and may play an important role on planetary radiative forcing and climate. However, little is known about the production and loss mechanisms of BrC in the atmosphere. Here, we study how the light absorptivity of BrC from wood smoke and secondary BrC generated from reaction of ammonium sulfate with methylglyoxal changes under photolytic aging by UVA radiation in the aqueous phase. Owing to its chemical complexity, BrC is separated by molecular weight using size exclusion chromatography and the response of each molecular weight fraction to aging is studied...
June 22, 2017: Environmental Science & Technology
https://www.readbyqxmd.com/read/28640601/initiation-of-the-electrochemical-reduction-of-co2-by-a-singly-reduced-ruthenium-ii-bipyridine-complex
#16
Srinivasan Ramakrishnan, Christopher E D Chidsey
The one-electron reduction of [CpRu(bpy)NCCH3]PF6 (Cp = cyclopentadienyl; bpy = 2,2'-bipyridine), abbreviated as [Ru-S](+), where S = CH3CN, in CO2-saturated acetonitrile initiates a cascade of rapid electrochemical and chemical steps (ECEC) at an electrode potential of ca. 100 mV positive of the first reduction of the ruthenium complex. The overall two-electron process leads to the generation of a CO-bound ruthenium complex, [Ru-CO](+), and carbonate, as independently confirmed by NMR spectroscopy. Simulations of the cyclic voltammograms using DigiElch together with density functional theory based calculations reveal that the singly reduced ruthenium complex [Ru-S](0) binds CO2 at a rate of ca...
June 22, 2017: Inorganic Chemistry
https://www.readbyqxmd.com/read/28640598/structural-and-light-absorption-characteristics-of-complex-water-insoluble-organic-mixtures-in-urban-submicron-aerosols
#17
Qingcai Chen, Fumikazu Ikemori, Yuua Nakamura, Petr Vodicka, Kimitaka Kawamura, Michihiro Mochida
Submicrometer aerosols in the urban atmosphere of Nagoya, Japan, were collected in late winter and early spring, and the water-insoluble organic matter (WISOM) in the samples were fractionated into six subfractions based on their polarities by using solvent and normal-phase solid-phase extractions: non-polar (F1), low-polar (F2 and F3), and medium-polar (F4, F5, and F6) fractions. The overall structural characteristics of these subfractions were then analyzed using Fourier transform infrared spectroscopy, nuclear magnetic resonance spectroscopy, and high-resolution aerosol mass spectrometry...
June 22, 2017: Environmental Science & Technology
https://www.readbyqxmd.com/read/28640583/fluffy-and-ordered-graphene-multilayer-films-with-improved-electromagnetic-interference-shielding-over-x-band
#18
Zicheng Wang, Renbo Wei, Xiaobo Liu
Highly ordered nitrogen-doped graphene multilayer films with large interlayer void are successfully fabricated by thermal annealing the compact stacking graphene oxide/copper phthalocyanine (GO/CuPc) multilayer films. Scanning electron microscopic (SEM), X-ray diffraction (XRD), Raman, X-ray photoelectron spectroscopic (XPS) and electrical conductivity measurements indicate that the breakaway of oxygen functional groups on/in the GO sheets at high temperature and the in-situ pyrolysis of CuPc molecules in the interlayer of graphene sheets synergistically facilitate the restoration of GO in graphitization, the effective nitrogen doping by replacing carbon atoms in graphene frameworks, the retention of layer-by-layer stacking structure of graphene sheets in plane and the formation of interlayer voids, leading to the enhancement in the electrical conductivity (3...
June 22, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28637351/tuning-surface-chemistry-of-polyetheretherketone-by-gold-coating-and-plasma-treatment
#19
Zdeňka Novotná, Silvie Rimpelová, Petr Juřík, Martin Veselý, Zdeňka Kolská, Tomáš Hubáček, Jakub Borovec, Václav Švorčík
Polyetheretherketone (PEEK) has good chemical and biomechanical properties that are excellent for biomedical applications. However, PEEK exhibits hydrophobic and other surface characteristics which cause limited cell adhesion. We have investigated the potential of Ar plasma treatment for the formation of a nanostructured PEEK surface in order to enhance cell adhesion. The specific aim of this study was to reveal the effect of the interface of plasma-treated and gold-coated PEEK matrices on adhesion and spreading of mouse embryonic fibroblasts...
December 2017: Nanoscale Research Letters
https://www.readbyqxmd.com/read/28637277/measuring-co2-and-hco3-permeabilities-of-isolated-chloroplasts-using-a-mims-18o-approach
#20
Dimitri Tolleter, Vincent Chochois, Richard Poiré, G Dean Price, Murray R Badger
To support photosynthetic CO2 fixation by Rubisco, the chloroplast must be fed with inorganic carbon in the form of CO2 or bicarbonate. However, the mechanisms allowing the rapid passage of this gas and this charged molecule through the bounding membranes of the chloroplast envelope are not yet completely elucidated. We describe here a method allowing us to measure the permeability of these two molecules through the chloroplast envelope using a membrane inlet mass spectrometer and 18O-labelled inorganic carbon...
June 16, 2017: Journal of Experimental Botany
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