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https://www.readbyqxmd.com/read/28314162/evaluation-of-the-distribution-of-activation-inside-a-compact-medical-cyclotron
#1
Toshioh Fujibuchi, Takatoshi Toyoda, Shingo Baba, Yoshiyuki Umezu, Isao Komiya, Masayuki Sasaki, Hiroshi Honda
The distribution of activation inside a compact medical cyclotron was evaluated by measuring 1cm dose equivalent rates and γ-ray spectra. Analysis of the distribution of activation showed high activation at the deflector and the magnetic channel. Radionuclides (60)Co, (57)Co, (65)Zn, and (54)Mn were detected. Different radionuclides were generated from different components of the cyclotron, and low-activity radionuclides could be detected under low-background-radiation conditions.
March 9, 2017: Applied Radiation and Isotopes
https://www.readbyqxmd.com/read/28304284/scanning-gate-microscopy-of-magnetic-focusing-in-graphene-devices-quantum-vs-classical-simulation
#2
Marko D Petrović, Slaviša Milovanović, Francois Peeters
We compare classical versus quantum electron transport in recently investigated magnetic focusing devices [S. Bhandari et al., Nano Lett. 16, 1690 (2016)] exposed to the perturbing potential of a scanning gate microscope (SGM). Using the Landauer-Büttiker formalism for a multi-terminal device, we calculate resistance maps that are obtained as the SGM tip is scanned over the sample. There are three unique regimes in which the scanning tip can operate (focusing, repelling, and mixed regime) which are investigated...
March 17, 2017: Nanotechnology
https://www.readbyqxmd.com/read/28287592/chemical-analysis-of-water-accommodated-fractions-of-crude-oil-spills-using-tims-ft-icr-ms
#3
Paolo Benigni, Rebecca Marin, Kathia Sandoval, Piero Gardinali, Francisco Fernandez-Lima
Multiple chemical processes control how crude oil is incorporated into seawater and also the chemical reactions that occur overtime. Studying this system requires the careful preparation of the sample in order to accurately replicate the natural formation of the water-accommodated fraction that occurs in nature. Low-energy water-accommodated fractions (LEWAF) are carefully prepared by mixing crude oil and water at a set ratio. Aspirator bottles are then irradiated, and at set time points, the water is sampled and extracted using standard techniques...
March 3, 2017: Journal of Visualized Experiments: JoVE
https://www.readbyqxmd.com/read/28286302/recent-advances-in-the-detection-of-specific-natural-organic-compounds-as-carriers-for-radionuclides-in-soil-and-water-environments-with-examples-of-radioiodine-and-plutonium
#4
REVIEW
P H Santschi, C Xu, S Zhang, K A Schwehr, P Lin, C M Yeager, D I Kaplan
Among the key environmental factors influencing the fate and transport of radionuclides in the environment is natural organic matter (NOM). While this has been known for decades, there still remains great uncertainty in predicting NOM-radionuclide interactions because of lack of understanding of radionuclide interactions with the specific organic moieties within NOM. Furthermore, radionuclide-NOM studies conducted using modelled organic compounds or elevated radionuclide concentrations provide compromised information related to true environmental conditions...
March 9, 2017: Journal of Environmental Radioactivity
https://www.readbyqxmd.com/read/28274593/in-depth-compositional-analysis-of-water-soluble-and-insoluble-organic-substances-in-fine-pm2-5-airborne-particles-using-ultra-high-resolution-15t-ft-icr-ms-and-gc%C3%A3-gc-tofms
#5
Jung Hoon Choi, Jijeong Ryu, Sodam Jeon, Jungju Seo, Yung-Hun Yang, Seung Pil Pack, Sungwook Choung, Kyoung-Soon Jang
Airborne particulate matter consisting of ionic species, salts, heavy metals and carbonaceous material is one of the most serious environmental pollutants owing to its impacts on the environment and human health. Although elemental and organic carbon compounds are known to be major components of aerosols, information on the elemental composition of particulate matter remains limited because of the broad range of compounds involved and the limits of analytical instruments. In this study, we investigated water-soluble and -insoluble organic compounds in fine (PM2...
March 5, 2017: Environmental Pollution
https://www.readbyqxmd.com/read/28273861/structural-characterization-of-core-region-in-erwinia-amylovora-lipopolysaccharide
#6
Angela Casillo, Marcello Ziaco, Buko Lindner, Susana Merino, Elena Mendoza-Barberá, Juan M Tomás, Maria Michela Corsaro
Erwinia amylovora (E. amylovora) is the first bacterial plant pathogen described and demonstrated to cause fire blight, a devastating plant disease affecting a wide range of species including a wide variety of Rosaceae. In this study, we reported the lipopolysaccharide (LPS) core structure from E. amylovora strain CFBP1430, the first one for an E. amylovora highly pathogenic strain. The chemical characterization was performed on the mutants waaL (lacking only the O-antigen LPS with a complete LPS-core), wabH and wabG (outer-LPS core mutants)...
March 4, 2017: International Journal of Molecular Sciences
https://www.readbyqxmd.com/read/28265613/tuning-the-oxidative-power-of-free-iron-sulfur-clusters
#7
Sandra M Lang, Shaodong Zhou, Helmut Schwarz
The gas-phase reactions between a series of di-iron sulfur clusters Fe2Sx(+) (x = 1-3) and the small alkenes C2H4, C3H6, and C4H8 have been investigated by means of Fourier-transform ion-cyclotron resonance mass spectrometry. For all studied alkenes, the reaction efficiency is found to increase in the order Fe2S(+) < Fe2S2(+) < Fe2S3(+). In particular, Fe2S(+) and Fe2S2(+) only form simple association products, whereas the sulfur-rich Fe2S3(+) is able to dehydrogenate propene and 2-butene via desulfurization of the cluster and formation of H2S...
March 7, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28265199/topological-origin-and-not-purely-antisymmetric-wave-functions-of-many-body-states-in-the-lowest-landau-level
#8
P Łydżba, J Jacak
In this paper, we recall the topological approach to quantum Hall effects. We note that, in the presence of a magnetic field, trajectories representing elements of the system's braid group are of cyclotron orbit type. In two-dimensional spaces, this leads to the restriction of the full braid group, π1(Ω)-loopless generators (exchanges of M(N) coordinates or classical particles) are unenforceable. As a result, the identification of a possible Hall-like state comes down to the identification of a possible subgroup of π1(Ω)...
January 2017: Proceedings. Mathematical, Physical, and Engineering Sciences
https://www.readbyqxmd.com/read/28262758/manipulation-of-a-nuclear-spin-by-a-magnetic-domain-wall-in-a-quantum-hall-ferromagnet
#9
M Korkusinski, P Hawrylak, H W Liu, Y Hirayama
The manipulation of a nuclear spin by an electron spin requires the energy to flip the electron spin to be vanishingly small. This can be realized in a many electron system with degenerate ground states of opposite spin polarization in different Landau levels. We present here a microscopic theory of a domain wall between spin unpolarized and spin polarized quantum Hall ferromagnet states at filling factor two with the Zeeman energy comparable to the cyclotron energy. We determine the energies and many-body wave functions of the electronic quantum Hall droplet with up to N = 80 electrons as a function of the total spin, angular momentum, cyclotron and Zeeman energies from the spin singlet ν = 2 phase, through an intermediate polarization state exhibiting a domain wall to the fully spin-polarized phase involving the lowest and the second Landau levels...
March 6, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28249485/electro-optic-probe-measurements-of-electric-fields-in-plasmas
#10
M Nishiura, Z Yoshida, T Mushiake, Y Kawazura, R Osawa, K Fujinami, Y Yano, H Saitoh, M Yamasaki, A Kashyap, N Takahashi, M Nakatsuka, A Fukuyama
The direct measurements of high-frequency electric fields in a plasma bring about significant advances in the physics and engineering of various waves. We have developed an electro-optic sensor system based on the Pockels effect. Since the signal is transmitted through an optical fiber, the system has high tolerance for electromagnetic noises. To demonstrate its applicability to plasma experiments, we report the first result of measurement of the ion-cyclotron wave excited in the RT-1 magnetosphere device. This study compares the results of experimental field measurements with simulation results of electric fields in plasmas...
February 2017: Review of Scientific Instruments
https://www.readbyqxmd.com/read/28242974/unit-cost-analysis-of-pet-ct-at-an-apex-public-sector-health-care-institute-in-india
#11
S H Gajuryal, A Daga, V Siddharth, C S Bal, S Satpathy
CONTEXT: PET/CT scan service is one of the capital intensive and revenue-generating centres of a tertiary care hospital. The cost associated with the provisioning of PET services is dependent upon the unit costs of the resources consumed. AIMS: The study aims to determine the cost of providing PET/CT Scan services in a hospital. METHODS AND MATERIAL: This descriptive and observational study was conducted in the Department of Nuclear Medicine at a tertiary apex teaching hospital in New Delhi, India in the year 2014-15...
January 2017: Indian Journal of Nuclear Medicine: IJNM: the Official Journal of the Society of Nuclear Medicine, India
https://www.readbyqxmd.com/read/28230979/simple-expendable-3d-printed-microfluidic-systems-for-sample-preparation-of-petroleum
#12
Érica M Kataoka, Rui C Murer, Jandyson M Santos, Rogério M Carvalho, Marcos N Eberlin, Fabio Augusto, Ronei J Poppi, Angelo L Gobbi, Leandro W Hantao
In this study, we introduce a simple protocol to manufacture disposable, 3D-printed microfluidic systems for sample preparation of petroleum. This platform is produced with a consumer-grade 3D-printer, using fused deposition modeling. Successful incorporation of solid-phase extraction (SPE) to microchip was ensured by facile 3D element integration using proposed approach. This 3D-printed μSPE device was applied to challenging matrices in oil and gas industry, such as crude oil and oil-brine emulsions. Case studies investigated important limitations of nonsilicon and nonglass microchips, namely, resistance to nonpolar solvents and conservation of sample integrity...
March 8, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28225596/top-down-metabolomic-approaches-for-nitrogen-containing-metabolites
#13
Ryo Nakabayashi, Kei Hashimoto, Kiminori Toyooka, Kazuki Saito
Streamlining the processes that reveal heteroatom-containing metabolites and their biosynthetic genes is essential in integrated metabolomics studies. These metabolites are especially targeted for their potential pharmaceutical activities. By using a Fourier-transform ion cyclotron resonance-mass spectrometry (FTICR-MS) instrument, we provide top-down targeted metabolomic analyses using ultrahigh-resolution liquid chromatography-mass spectrometry (LC-MS), high-resolution matrix-assisted laser desorption/ionization (MALDI), and high-resolution imaging mass spectrometry (IMS) with (15)N labeling of nitrogen-containing metabolites...
February 22, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28215801/differences-in-dom-of-rewetted-and-natural-peatlands-results-from-high-field-ft-icr-ms-and-bulk-optical-parameters
#14
Peter Herzsprung, Katja Osterloh, Wolf von Tümpling, Mourad Harir, Norbert Hertkorn, Philippe Schmitt-Kopplin, Ralph Meissner, Sabine Bernsdorf, Kurt Friese
Peatlands can be a potential source of dissolved organic matter (DOM) in fresh water catchment areas. The quantity and quality of DOM can differ between pristine, degraded and rewetted peatlands. Due to the large scale and continuing losses of peatlands, their conservation and restoration has been increasingly emphasized. Mostly rewetting measures are required to improve the hydrology of damaged peatlands, which is a precondition for the resettlement of peat-forming plant species. Thus, in term of DOM, there is a special need to understand how rewetting measures affect DOM characteristics and concentrations...
May 15, 2017: Science of the Total Environment
https://www.readbyqxmd.com/read/28213728/fourier-transform-ion-cyclotron-resonance-mass-spectrometry-at-the-cyclotron-frequency
#15
Konstantin O Nagornov, Anton N Kozhinov, Yury O Tsybin
The phenomenon of ion cyclotron resonance allows for determining mass-to-charge ratio, m/z, of an ensemble of ions by means of measurements of their cyclotron frequency, ω c . In Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS), the ω c quantity is usually unavailable for direct measurements: the resonant state is located close to the reduced cyclotron frequency (ω+), whereas the ω c and the corresponding m/z values may be calculated via theoretical derivation from an experimental estimate of the ω+ quantity...
February 17, 2017: Journal of the American Society for Mass Spectrometry
https://www.readbyqxmd.com/read/28213336/linking-the-mobilization-of-dissolved-organic-matter-in-catchments-and-its-removal-in-drinking-water-treatment-to-its-molecular-characteristics
#16
Julia Raeke, Oliver J Lechtenfeld, Jörg Tittel, Marieke R Oosterwoud, Katrin Bornmann, Thorsten Reemtsma
Drinking water reservoirs in the Northern Hemisphere are largely affected by the decadal-long increase in riverine dissolved organic carbon (DOC) concentrations. The removal of DOC in drinking water treatment is costly and predictions are needed to link DOC removal efficiency to its mobilization in catchments, both of which are determined by the molecular composition. To study the effect of hydrological events and land use on the molecular characteristics of dissolved organic matter (DOM), 36 samples from three different catchment areas in the German low mountain ranges, with DOC concentrations ranging from 3 to 32 mg L(-1), were examined...
April 15, 2017: Water Research
https://www.readbyqxmd.com/read/28211563/cytotoxic-analysis-and-chemical-characterization-of-fractions-of-the-hydroalcoholic-extract-of-the-euterpe-oleracea-mart-seed-in-the-mcf-7-cell-line
#17
Dayanne da S Freitas, José A Morgado-Díaz, Adriana S Gehren, Flávia C B Vidal, Raquel Maria T Fernandes, Wanderson Romão, Lilian V Tose, Fabiola N S Frazão, Maria Célia P Costa, Dulcelena F Silva, Maria do Desterro S B Nascimento
OBJECTIVES: To analyse the antineoplastic activity of fractions derived from the hydroalcoholic extract of Euterpe oleracea Mart. seed in the MCF-7 cell line and to identify the compounds responsible for the antineoplastic action. METHODS: Cells were treated with 10, 20, 40 and 60 μg/ml with the hexane, chloroform and ethyl acetate fraction (EAF) of the hydroalcoholic extract of açaí seed, for 24 and 48 h. After treatment, cell viability was measured using MTT assay and cell death was assessed using the Annexin-Pi assay...
February 17, 2017: Journal of Pharmacy and Pharmacology
https://www.readbyqxmd.com/read/28209500/theoretical-estimation-of-64-cu-production-with-neutrons-emitted-during-18-f-production-with-a-30mev-medical-cyclotron
#18
Lucrezia Auditore, Ernesto Amato, Sergio Baldari
PURPOSE: This work presents the theoretical estimation of a combined production of (18)F and (64)Cu isotopes for PET applications. (64)Cu production is induced in a secondary target by neutrons emitted during a routine (18)F production with a 30MeV cyclotron: protons are used to produce (18)F by means of the (18)O(p,n)(18)F reaction on a [(18)O]-H2O target (primary target) and the emitted neutrons are used to produce (64)Cu by means of the (64)Zn(n,p)(64)Cu reaction on enriched zinc target (secondary target)...
February 3, 2017: Applied Radiation and Isotopes
https://www.readbyqxmd.com/read/28193065/native-ms-analysis-of-bacteriorhodopsin-and-an-empty-nanodisc-by-orthogonal-acceleration-time-of-flight-orbitrap-and-ion-cyclotron-resonance
#19
Iain D G Campuzano, Huilin Li, Dhanashri Bagal, Jennifer L Lippens, Juraj Svitel, Robert J M Kurzeja, Han Xu, Paul D Schnier, Joseph A Loo
Over the past two decades, orthogonal acceleration time-of-flight has been the de facto analyzer for solution and membrane-soluble protein native mass spectrometry (MS) studies; this however is gradually changing. Three MS instruments are compared, the Q-ToF, Orbitrap, and the FT-ICR, to analyze, under native instrument and buffer conditions, the seven-transmembrane helical protein bacteriorhodopsin-octylglucoside micelle and the empty nanodisc (MSP1D1-Nd) using both MS and tandem-MS modes of operation. Bacteriorhodopsin can be released from the octylglucoside-micelle efficiently on all three instruments (MS-mode), producing a narrow charge state distribution (z = 8+ to 10+) by either increasing the source lens or collision cell (or HCD) voltages...
December 20, 2016: Analytical Chemistry
https://www.readbyqxmd.com/read/28187357/a-simple-thick-target-for-production-of-89-zr-using-an-11mev-cyclotron
#20
Jeanne M Link, Kenneth A Krohn, Matthew J O'Hara
The growing interest but limited availability of (89)Zr for PET led us to test targets for the (89)Y(p,n) reaction. The goal was an easily constructed target for an 11MeV Siemens cyclotron. Yttrium foils were tested at different thicknesses, angles and currents. A 90° foil tolerated 41µA without damage and produced ~800 MBq/h, >20mCi, an amount adequate for radiochemistry research and human doses in a widely available accelerator. This method should translate to higher energy cyclotrons.
January 30, 2017: Applied Radiation and Isotopes
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