keyword
MENU ▼
Read by QxMD icon Read
search

cyclotron

keyword
https://www.readbyqxmd.com/read/28213728/fourier-transform-ion-cyclotron-resonance-mass-spectrometry-at-the-cyclotron-frequency
#1
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
#2
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...
February 8, 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
#3
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
#4
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
#5
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
#6
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
https://www.readbyqxmd.com/read/28186141/spatial-variations-in-the-molecular-diversity-of-dissolved-organic-matter-in-water-moving-through-a-boreal-forest-in-eastern-finland
#7
Jun'ichiro Ide, Mizue Ohashi, Katsutoshi Takahashi, Yuko Sugiyama, Sirpa Piirainen, Pirkko Kortelainen, Nobuhide Fujitake, Keitaro Yamase, Nobuhito Ohte, Mina Moritani, Miyako Hara, Leena Finér
Dissolved organic matter (DOM) strongly affects water quality within boreal forest ecosystems. However, how the quality of DOM itself changes spatially is not well understood. In this study, to examine how the diversity of DOM molecules varies in water moving through a boreal forest, the number of DOM molecules in different water samples, i.e., rainwater, throughfall, soil water, groundwater, and stream water was determined using Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) in Norway spruce and Scots pine stands in eastern Finland during May and June 2010...
February 10, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28183041/an-automated-flow-system-incorporating-in-line-acid-dissolution-of-bismuth-metal-from-a-cyclotron-irradiated-target-assembly-for-use-in-the-isolation-of-astatine-211
#8
Matthew J O'Hara, Anthony J Krzysko, Cynthia M Niver, Samuel S Morrison, Stanley L Owsley, Donald K Hamlin, Eric F Dorman, D Scott Wilbur
Astatine-211 ((211)At) is a promising cyclotron-produced radionuclide being investigated for use in targeted alpha therapy. The wet chemical isolation of trace quantities of (211)At, produced within several grams of Bi metal deposited onto an aluminum cyclotron target assembly, involves a multi-step procedure. Because the (211)At isolation method is labor-intensive and complex, automation of the method is being developed to facilitate routine processing at the University of Washington and to make it easier to transfer the process to other institutions...
February 2, 2017: Applied Radiation and Isotopes
https://www.readbyqxmd.com/read/28181913/simulation-on-the-electronic-wave-packet-cyclotron-motion-in-a-weyl-semimetal-slab
#9
Haibo Yao, Mingfeng Zhu, Liwei Jiang, Yisong Zheng
We perform a numerical simulation on time evolution of electronic wave packet in a Weyl semimetal(WSM) slab driven by a magnetic field. We find that the evolution trajectory of the wave packet depends sensitively on its initial spin state. Only the initial spin state being identical to that of the Fermi arc state at the surface it localized, does the wave packet evolution demonstrate the characteristic cyclotron orbit of WSM predicted previously from a semiclassical viewpoint. By analyzing the eigen-expansion of the electronic wave packet, we find the chiral Landau Levels(LLs) of the WSM slab, as an ingredient of the wave packet, is responsible for establishing the characteristic cyclotron orbit of Weyl semimetal...
February 9, 2017: Journal of Physics. Condensed Matter: An Institute of Physics Journal
https://www.readbyqxmd.com/read/28181731/two-dimensional-mass-spectrometry-in-a-linear-ion-trap-an-in-silico-model
#10
Maria A van Agthoven, Peter B O'Connor
RATIONALE: Two-dimensional mass spectrometry is a technique that correlates precursor and product ions in a sample without requiring prior ion isolation. Until now, this technique has only been implemented on Fourier transform ion cyclotron resonance mass spectrometers. By coupling two-dimensional mass spectrometry techniques in linear ion traps with a mass analyser with a fast duty cycle (e.g. time-of-flight), data-independent tandem mass spectrometry techniques can be compatible on an LC or GC timescale...
February 9, 2017: Rapid Communications in Mass Spectrometry: RCM
https://www.readbyqxmd.com/read/28165700/intrinsic-and-stable-conjugation-of-thiolated-mesoporous-silica-nanoparticles-with-radioarsenic
#11
Paul A Ellison, Feng Chen, Shreya Goel, Todd E Barnhart, Robert J Nickles, Onofre T DeJesus, Weibo Cai
The development of new image-guided drug delivery tools to improve the therapeutic efficacy of chemotherapeutics remains an important goal in nanomedicine. Using labeling strategies that involve radioelements that have theranostic pairs of diagnostic positron-emitting isotopes and therapeutic electron-emitting isotopes has promise in achieving this goal and further enhancing drug performance through radiotherapeutic effects. The isotopes of radioarsenic offer such theranostic potential and would allow for the use of positron emission tomography (PET) for image-guided drug delivery studies of the arsenic-based chemotherapeutic arsenic trioxide (ATO)...
February 6, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28150226/can-spatiotemporal-fluoride-18-f-uptake-be-used-to-assess-bone-formation-in-the-tibia-a-longitudinal-study-using-pet-ct
#12
Henrik Lundblad, Charlotte Karlsson-Thur, Gerald Q Maguire, Cathrine Jonsson, Marilyn E Noz, Michael P Zeleznik, Lars Weidenhielm
BACKGROUND: When a bone is broken for any reason, it is important for the orthopaedic surgeon to know how bone healing is progressing. There has been resurgence in the use of the fluoride ((18)F(-)) ion to evaluate various bone conditions. This has been made possible by availability of positron emission tomography (PET)/CT hybrid scanners together with cyclotrons. Absorbed on the bone surface from blood flow, (18)F(-) attaches to the osteoblasts in cancellous bone and acts as a pharmacokinetic agent, which reflects the local physiologic activity of bone...
February 1, 2017: Clinical Orthopaedics and related Research
https://www.readbyqxmd.com/read/28147509/cooling-of-isolated-anthracene-cations-probed-with-photons-of-different-wavelengths-in-the-mini-ring
#13
M Ji, J Bernard, L Chen, R Brédy, C Ortéga, C Joblin, A Cassimi, S Martin
We report on a direct measurement of the Internal Energy Distribution (IED) shift rate of an initially hot polycyclic aromatic hydrocarbon (PAH) molecular ensemble, anthracene cations (C14H10(+)). The ions were produced in an electron cyclotron resonance (ECR) ion source and stored in an electrostatic ion storage ring, the Mini-Ring. Laser pulses of two wavelengths were sent successively to merge the stored ion bunch at different storage times to enhance the neutral fragment yield due to fast laser induced dissociation...
January 28, 2017: Journal of Chemical Physics
https://www.readbyqxmd.com/read/28138744/enumeration-of-carboxyl-groups-carried-on-individual-components-of-humic-systems-using-deuteromethylation-and-fourier-transform-mass-spectrometry
#14
Alexander Zherebker, Yury Kostyukevich, Alexey Kononikhin, Oleg Kharybin, Andrey I Konstantinov, Kirill V Zaitsev, Eugene Nikolaev, Irina V Perminova
Here, we report a novel approach to enumeration of carboxylic groups carried by individual molecules of humic substances using selective chemical modification and isotopic labeling (deuteromethylation) and high-resolution electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI FTICR MS). Esterification was conducted with a use of thionyl chloride-deuteromethanol reagent under mild conditions to avoid transesterification. The deuteromethylated products were subjected to solid phase extraction using PPL Bond Elute cartridges prior to FTICR MS analysis...
January 30, 2017: Analytical and Bioanalytical Chemistry
https://www.readbyqxmd.com/read/28130978/novel-ion-exchange-chromatography-method-for-nca-arsenic-separation
#15
Z Oláh, T Kremmer, A T Vogg, Z Varga, Z Szűcs, B Neumaier, R Dóczi
A high-performance liquid chromatography (HPLC) device equipped with an anion exchange column was used to isolate nca (77)As from reactor irradiated (nat)GeO2 targets. The oxidation states of the isotope (77)As during the process was verified by thin layer chromatography. The radionuclidic purity of the separated fractions was checked by gamma measurements and it was found to be 99.91% for the As fraction. The elaborated method was applied to separate the isotope (74)As from cyclotron irradiated (nat)GeO2 targets too...
January 14, 2017: Applied Radiation and Isotopes
https://www.readbyqxmd.com/read/28121132/molecular-composition-and-photochemical-reactivity-of-size-fractionated-dissolved-organic-matter
#16
Andrew Chapin Maizel, Christina K Remucal
The photochemical production of reactive species, such as triplet dissolved organic matter ((3)DOM) and singlet oxygen ((1)O2), contributes to the degradation of aquatic contaminants and is related to an array of DOM structural characteristics, notably molecular weight. In order to relate DOM molecular weight, optical properties, and reactive species production, Suwannee River (SRFA) and Pony Lake fulvic acid (PLFA) isolates are fractionated by sequential ultrafiltration and the resultant fractions are evaluated in terms of molecular composition and photochemical reactivity...
January 25, 2017: Environmental Science & Technology
https://www.readbyqxmd.com/read/28102507/-44-sc-psma-617-for-radiotheragnostics-in-tandem-with-177-lu-psma-617-preclinical-investigations-in-comparison-with-68-ga-psma-11-and-68-ga-psma-617
#17
Christoph A Umbricht, Martina Benešová, Raffaella M Schmid, Andreas Türler, Roger Schibli, Nicholas P van der Meulen, Cristina Müller
BACKGROUND: The targeting of the prostate-specific membrane antigen (PSMA) is of particular interest for radiotheragnostic purposes of prostate cancer. Radiolabeled PSMA-617, a 1,4,7,10-tetraazacyclododecane-N,N',N'',N'''-tetraacetic acid (DOTA)-functionalized PSMA ligand, revealed favorable kinetics with high tumor uptake, enabling its successful application for PET imaging ((68)Ga) and radionuclide therapy ((177)Lu) in the clinics. In this study, PSMA-617 was labeled with cyclotron-produced (44)Sc (T 1/2 = 4...
December 2017: EJNMMI Research
https://www.readbyqxmd.com/read/28102393/chemically-reversible-binding-of-h2s-to-a-zinc-porphyrin-complex-towards-implementation-of-a-reversible-sensor-via-a-coordinative-based-approach
#18
Maria Strianese, Marina Lamberti, Claudio Pellecchia
Binding of hydrogen sulfide (H2S) to a zinc porphyrin complex and the stabilization of the related zinc hydrosulfido adduct are explored. High-resolution MALDI Fourier transform ion cyclotron resonance mass spectrometry (HR MALDI-FT-ICR) and (1)H NMR experiments provide evidence that HS(-) coordination occurs at the zinc centre. The coordination of HS(-) occurs in a reversible manner and modulates fluorescence emission of a tetra(N-methylpyridyl)porphine zinc complex (TMPyPZn). The results highlight the potential of TMPyPZn and related systems for the implementation of fast and simple H2S sensors via a coordinative-based approach...
January 19, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
https://www.readbyqxmd.com/read/28098448/new-insights-into-trihalomethane-and-haloacetic-acid-formation-potentials-correlation-with-the-molecular-composition-of-natural-organic-matter-in-source-water
#19
Xin Wang, Haifeng Zhang, Yahe Zhang, Quan Shi, Juan Wang, Jianwei Yu, Min Yang
Natural organic matter (NOM) represents the major source of precursors for disinfection byproducts (DBPs), such as trihalomethanes (THMs) and haloacetic acids (HAAs), formed during disinfection of drinking water, but the molecular composition and reactivity of NOM remain not well understood. In this study, electrospray ionization coupled to Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) was used to characterize the molecular composition of NOM of 20 source waters taken across China for the purpose of determining the major precursors of THMs and HAAs at molecular level...
February 2, 2017: Environmental Science & Technology
https://www.readbyqxmd.com/read/28070341/low-temperature-metal-free-growth-of-graphene-on-insulating-substrates-by-plasma-assisted-chemical-vapor-deposition
#20
R Muñoz, C Munuera, J I Martínez, J Azpeitia, C Gómez-Aleixandre, M García-Hernández
Direct growth of graphene films on dielectric substrates (quartz and silica) is reported, by means of remote electron cyclotron resonance plasma assisted chemical vapor deposition r-(ECR-CVD) at low temperature (650°C). Using a two step deposition process- nucleation and growth- by changing the partial pressure of the gas precursors at constant temperature, mostly monolayer continuous films, with grain sizes up to 500 nm are grown, exhibiting transmittance larger than 92% and sheet resistance as low as 900 Ω·sq(-1)...
March 2017: 2d Mater
keyword
keyword
115150
1
2
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"