TY - JOUR. T1 - Atmospheric pressure chemical ionization Fourier transform ion cyclotron resonance mass spectrometry for complex thiophenic mixture analysis. AU - Hourani, Nadim. AU - Andersson, Jan T.. AU - Möller, Isabelle. AU - Amad, Maan H.. AU - Witt, Matthías. AU - Sarathy, Mani. N1 - KAUST Repository Item: Exported on 2020-10-01 Acknowledgements: The work at KAUST was funded by the Clean Combustion Research Center and by Saudi Aramco under the FUELCOM program.. PY - 2013/10/1. Y1 - 2013/10/1. N2 - Rationale Polycyclic aromatic sulfur heterocycles (PASHs) are detrimental species for refining processes in petroleum industry. Current mass spectrometric Methods that determine their composition are often preceded by derivatization and dopant addition approaches. Different ionization Methods have different impact on the molecular assignment of complex PASHs. The analysis of such species under atmospheric pressure chemical ionization (APCI) is still considered limited due to uncontrolled ion ...
Search and download thousands of Swedish university dissertations (essays). Full text. Free. Dissertation: High Rate Electron Capture Dissociation Fourier Transform Ion Cyclotron Resonance Mass Spectrometry.
Abstract In this study, a reliable and sensitive ultrahigh performance liquid chromatography coupled with fourier transform ion cyclotron resonance mass spectrometry method was developed for the systematic study of the metabolic profile of Kudiezi injection in rat plasma, bile, urine, and feces after intravenous administration of a single dose....
A Top-Down Proteomics Platform Coupling Serial Size Exclusion Chromatography and Fourier Transform Ion Cyclotron Resonance Mass ...
Structural information obtained by negative-ion laser desorption ionization Fourier transform ion cyclotron resonance (l.d.i.-F.t-i.c.r.) mass spectrometry on bacterial capsular ...
Аннотация доклада: Fourier Transform Ion Cyclotron Resonance Mass spectrometry (FTICR MS) is widely used to explore molecular space of humic substances. However, it cannot easily distinguish between structural isomers. We have developed an approach of selective H/D exchange (HDX) coupled to FTICR MS, which provides information about C-H bonds of individual species. This study demonstrates feasibility of comparing structures with common molecular formulas identified in HS from different sources. We believe that combination of different selective isotope labeling techniques will enable identification of individual molecular compartments of natural HS. ...
Polyolefins such as polyethylene (PE) and polypropylene (PP) are often characterized from their pyrolysis products by Py-MS. Nowadays the development of plasma-based direct probe atmospheric pressure sources allow the direct analysis of these polymers. These sources operate at atmospheric pressure, which implies a limited control of the ionization conditions. It was shown that side reactions could occur with species present in air, such as O2, which may lead to the formation of oxidized compounds. In this work, ion mobility-mass spectrometry (IM-MS) and Fourier transform ion cyclotron resonance mass spectrometry (FTICR) were used for the exhaustive characterization of the PP and PE pyrolysis ions produced using plasma-based atmospheric pressure ion sources. Both PP and PE yielded distributions of pyrolysis products presenting different amounts of unsaturation but also different numbers of oxygen atoms. In addition, the ions produced from PP presented a lower collision cross-section (CCS) than those
This review offers an introduction to the principles and generic applications of FT-ICR mass spectrometry, directed to readers with no prior experience with the technique. We are able to explain the fundamental FT-ICR phenomena from a simplified theoretical treatment of ion behavior in idealized mag …
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The detailed glycan structural analysis of glycoprotein is amenable to glycopeptide enrichment. Here, we develop a simple, effective and economical approach to enrich glycopeptides from proteolytically digested peptide mixtures by chromatographic column packed with graphite carbon and activated charcoal (G/A-column). Glycopeptide from ovalbumin was efficiently enriched by homemade G/A-column using liquid chromatography and the structure of glycopeptide was obtained by tandem mass spectrometry using Fourier transform ion cyclotron resonance mass spectrometry. The results in this study demonstrate that G/A-column can be used to enrich N-glycolpeptides and be benefit for online identification of glycopeptide using LC-MS.
Diastereochemical differentiation of β-amino acids using host-guest complexes studied by fourier transform ion cyclotron resonance mass spectrometry | Anna R.M. Hyyryläinen; Jaana M.H. Pakarinen; Pirjo Vainiotalo; Géza Stájer; Ferenc Fülöp | download | BookSC. Download books for free. Find books
Electrospray ionization (ESI) was performed on a Fourier transform ion cyclotron resonance mass spectrometer for the endgroup and monomer mass determination of three poly(oxyalkylene)s in the mass range of 400-8000 Da. A combined use of the multiple charge states observed with ESI, leads to a threefold increase in accuracy of the endgroup and monomer determination. The improvement is attributed to the increased number of datapoints used for the regression procedure, yielding more accurate results. Endgroup masses are determined with a mass error better than 5 and 75 millimass units for the molecular weight range of 400-4200 and 6200-8000 Da, respectively. A mass error of better than 1 millimass unit was observed for all monomer mass determinations. With ESI, endgroup and monomer masses have been determined for poly(ethylene glycol) oligomers with a mass higher than 8000 Da. This is almost two times higher than observed with matrix-assisted laser desorption/ ionization on the same ...
article{4bf893b7-614c-4304-ae07-10d1532c9337, abstract = {,p,The feasibility of global glycoprotein analysis by electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry and infrared multiphoton dissociation (IRMPD) tandem mass spectrometry is demonstrated. Combined 2D gel glycoprotein separation and visualization, in-gel digestion, and accurate (<10 ppm) mass measurement allowed identification of human glycoproteins and revealed differences in glycosylation. IRMPD obviates the need for glycan release, which prevents sample dispersal, and allows the assignment of glycan structures to specific sites of N-glycosylation.,/p,}, author = {Håkansson, Kristina and Emmett, Mark R and Marshall, Alan G and Davidsson, Pia and Nilsson, Carol L}, issn = {1535-3893}, keyword = {Carbohydrate Conformation,Carbohydrate Sequence,Electrophoresis, Gel, Two-Dimensional,Glycoproteins,Humans,Mass Spectrometry,Molecular Sequence Data,Peptides,Protein Conformation,Protein Isoforms,Journal ...
Motivation: The development of better tests to detect cancer in its earliest stages is one of the most sought-after goals in medicine. Especially important are minimally invasive tests that require only blood or urine samples. By profiling oligosaccharides cleaved from glycosylated proteins shed by tumor cells into the blood stream, we hope to determine glycan profiles that will help identify cancer patients using a simple blood test. The data in this article were generated using matrix-assisted laser desorption/ionization Fourier transform ion cyclotron resonance mass spectrometry (MALDI FT-ICR MS). We have developed novel methods for analyzing this type of mass spectrometry data and applied it to eight datasets from three different types of cancer (breast, ovarian and prostate).. Results: The techniques we have developed appear to be effective in the analysis of MALDI FT-ICR MS data. We found significant differences between control and cancer groups in all eight datasets, including two ...
TY - CONF. T1 - Lipidomic Analysis by Liquid Chromatography-Ion Cyclotron Resonance Mass Spectrometry. AU - Fauland, Alexander. AU - Trötzmüller, Martin. AU - Guo, Xinghua. AU - Eberl, Anita. AU - Köfeler, Harald. AU - Lankmayr, Ernst. PY - 2011/9/18. Y1 - 2011/9/18. M3 - (Old data) Lecture or Presentation. ER - ...
TY - JOUR. T1 - Profiling of glycans in serum for the discovery of potential biomarkers for ovarian cancer. AU - An, Hyun Joo. AU - Miyamoto, Suzanne. AU - Lancaster, Katherine S.. AU - Kirmiz, Crystal. AU - Li, Bensheng. AU - Lam, Kit. AU - Leiserowitz, Gary S. AU - Lebrilla, Carlito B. PY - 2006/7. Y1 - 2006/7. N2 - A glycomic approach is developed to identify oligosaccharide markers for ovarian cancer by rapidly profiling globally released oligosaccharides. Glycoproteins shed by cancer cells are found in the supernatant (or conditioned media) of cultured cells. In this approach, shed glycoproteins are profiled for their oligosaccharide content using β-elimination conditions. Changes in glycosylation are monitored by matrix-assisted laser desorption/ionization Fourier transform ion cyclotron resonance mass spectrometry (MALDI-FTICR-MS). Because shed glycoproteins would also be found in serum, similar glycan profiling was performed to observe potential oligosaccharide markers. Oligosaccharide ...
Glycomics, a comprehensive study of glycans expressed in biologic systems, is emerging as a simple yet highly sensitive diagnostic tool for disease onset and progression. This study aimed to use glycomics to investigate glycan markers that would differentiate patients with gastric cancer from those with nonatrophic gastritis. Patients with duodenal ulcer were also included because they are thought to represent a biologically different response to infection with Helicobacter pylori, a bacterial infection that can cause either gastric cancer or duodenal ulcer. We collected 72 serum samples from patients in Mexico City that presented with nonatrophic gastritis, duodenal ulcer, or gastric cancer. N-glycans were released from serum samples using the generic method with PNGase F and were analyzed by matrix-assisted laser desorption/ionization Fourier transform-ion cyclotron resonance mass spectrometry. The corresponding glycan compositions were calculated based on accurate mass. ANOVA-based ...
Positive-ion electrospray-fourier transform ion cyclotron resonance mass spectra of polypeptides and proteins.: We have determined the mass spectra of three pol
Bovine β-lactoglobulin (β-Lg) is a major allergen existing in milk and causes about 90% of IgE-mediated cows milk allergies. Previous studies showed that pulsed electric field (PEF) treatment could partially unfold the protein, which may contribute to the improvement of protein glycation. In this study, the effect of PEF pretreatment combined with glycation on the IgG/IgE-binding ability and the structure of β-Lg was investigated. The result showed that PEF pretreatment combined with glycation significantly reduced the IgG and IgE binding abilities, which was attributed to the changes of secondary and tertiary structure and the increase in glycation sites and degree of substitution per peptide (DSP) value determined by electron capture dissociation Fourier transform ion cyclotron resonance mass spectrometry (ECD/FTICR-MS ...
Beryllium-7 (Be-7) only decays by electron capture into lithium-7 (Li-7) with a half life of 53 days. We study the effect of ionization on this decay rate. We do so by trapping a Be-7 ion plasma in a cylindrical Malmberg-Penning trap and measuring Be-7 and Li-7 concentrations as functions of time by using Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS). We have simulated these signals in a 2-dimensional electrostatic particle-in-cell (PIC) code. The two spectrum peaks merge at high ion densities whereas at low ion densities they can be resolved. The merged peak shifts linearly according to the relative abundances of these species. We have also simulated singly-ionized beryllium-7 hydride (BeH+) and Li-7 ion plasmas at high densities. These two separate peaks shift according to their relative abundances. We describe an analytical model that explains how these peaks shift.
The production of biosurfactant by Bacillus subtilis LSFM-05 was carried out using raw glycerol, obtained from a vegetable oil biodiesel plant in Brazil, as the sole carbon source. Production of the biosurfactant was carried out in a 15-L bench-top fermentor and the surfactant was obtained from the foam produced. The crude surfactant was purified by silica gel column chromatography with a yield of 230 mg of the purified biosurfactant per liter of foam. TLC, IR spectroscopy. H-1 and C-13 NMR and Fourier transform ion cyclotron resonance mass spectrometry with electrospray ionization (ESI-FTMS) were used to characterize the purified surfactant. The isolated surfactant was identified as a surfactin lipopeptide. MS/MS data identified the amino acid sequence as GluOMe-Leu-Leu-Asp-Val-Leu-Leu and showed that the fatty acid moiety contained 14 carbons in iso, anteiso or normal configurations. The critical micelle concentration of the C-14/Leu(7) surfactin was 70 mu M, with emulsification efficiency ...
Characterization of oil sands naphthenic acids treated with ultraviolet and microwave radiation by negative ion electrospray Fourier transform ion cyclotron resonance mass spectrometry (pages 3121-3126). John V. Headley, Kerry M. Peru, Sabyasachi Mishra, Venkatesh Meda, Ajay K. Dalai, Dena W. McMartin, Mmilili M. Mapolelo, Ryan P. Rodgers and Alan G. Marshall. Version of Record online: 5 OCT 2010 , DOI: 10.1002/rcm.4754. ...
Native top-down electrospray ionization-mass spectrometry of 158 kDa protein complex by high-resolution Fourier transform ion cyclotron resonance mass spectrometry ...
A non-invasive diagnostic approach is crucial for the evaluation of severity of liver disease, treatment decisions, and assessing drug efficacy. This study evaluated plasma proteomic profiling via an N-terminal isotope tagging strategy coupled with liquid chromatography/Fourier transform ion cyclotron resonance mass spectrometry measurement to detect liver fibrosis staging. Pooled plasma from different liver fibrosis stages, which were assessed in advance by the current gold-standard of liver biopsy, was quantitatively analyzed. A total of 72 plasma proteins were found to be dysregulated during the fibrogenesis process, and this finding constituted a valuable candidate plasma biomarker bank for follow-up analysis. Validation results of fibronectin by Western blotting reconfirmed the mass-based data. Ingenuity Pathways Analysis showed four types of metabolic networks for the functional effect of liver fibrosis disease in chronic hepatitis B patients. Consequently, quantitative proteomics via the ...
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Hydrogen/deuterium exchange (HDX) coupled to mass spectrometry permits analysis of structure, dynamics, and molecular interactions of proteins. HDX mass spectrometry is confounded by deuterium exchange-associated peaks overlapping with peaks of heavy, natural abundance isotopes, such as carbon-13. Recent studies demonstrated that high-performance mass spectrometers could resolve isotopic fine structure and eliminate this peak overlap, allowing direct detection and quantification of deuterium incorporation. Here, we present a graphical tool that allows for a rapid and automated estimation of deuterium incorporation from a spectrum with isotopic fine structure. Given a peptide sequence (or elemental formula) and charge state, the mass-to-charge ratios of deuterium-associated peaks of the specified ion is determined. Intensities of peaks in an experimental mass spectrum within bins corresponding to these values are used to determine the distribution of deuterium incorporated. A theoretical spectrum can
With a highly sensitive electrospray ionization-Fourier transform ion cyclotron resonance mass spectrometry (ESI-FTICR MS) system, proteins were identified in minimal amounts of spinal cord from patients with the neurodegenerative disease amyotrophic lateral sclerosis (ALS) and compared to proteins in spinal cord from control subjects. The results show 18 versus 16 significantly identified (p | 0.05) proteins, respectively, all known to be found in the central nervous system. The most abundant protein in both groups was the glial fibrillary acidic protein, GFAP. Other proteins were, for example, hemoglobin alpha- and beta chain, myelin basic protein, thioredoxin, alpha enolase, and choline acetyltransferase. This study also includes the technique of laser microdissection in combination with pressure catapulting (LMPC) for the dissection of samples and specific neurons. Furthermore, complementary experiments with nanoLC-matrix assisted laser desorption ionization time-of-flight tandem mass spectrometry
To identify release points, assess fate, and monitor exposure, we need reliable methods for detecting and quantifying engineered carbon nanomaterials (ECNs) in the environment. However, quantitative extraction and separation of ECNs from environmental sample is extremely difficult. Additionally, ECNs are indistinguishable from graphitic carbon ubiquitous in the environment in regions of the electromagnetic spectrum probed by modern spectroscopy, including absorption, fluorescence, scattering (at UV, IR, and X-ray wavelengths), and NMR. We use a novel approach based upon a unique molecular signature of ECNs C zero mass defect. The detection is enabled by atmospheric pressure photoionization (APPI) coupled with ultrahigh resolution ion cyclotron resonance mass spectrometer. We were able to detect trace concentration of molecular C60 in the presence of aquatic natural organic matter ...
TY - JOUR. T1 - Conformational epitope mapping of Pru du 6, a major allergen from almond nut. AU - Willison, LeAnna N.. AU - Zhang, Qian. AU - Su, Mengna. AU - Teuber, Suzanne S. AU - Sathe, Shridhar K.. AU - Roux, Kenneth H.. PY - 2013/10. Y1 - 2013/10. N2 - Tree nuts are a widely consumed food. Although enjoyed safely by most individuals, allergic reactions to tree nuts, including almond, are not uncommon. Almond prunin (Pru du 6), an 11S globulin (legumin), is an abundant nut seed protein and a major allergen. Conformational epitope mapping studies of prunin have been performed with a murine monoclonal antibody (mAb) 4C10. This mAb reacts with non-reduced but not reduced prunin in immunoblotting assays, indicating the recognition of a conformational epitope. 4C10 competes with patient IgE, as assessed by ELISA, indicating clinical significance of the epitope. To characterize the 4C10 epitope, hydrogen/deuterium exchange (HDX) monitored by 14.5. T Fourier transform ion cyclotron resonance mass ...
Cyclotron Market - Scope of the Report. TMRs report on the global cyclotron market studies past as well as current growth trends and opportunities to gain valuable insights of the same indicators for the market during the forecast period from 2020 to 2030. The report provides revenue of the global cyclotron market for the period 2018-2030, considering 2019 as the base year and 2030 as the forecast year. The report also provides the compound annual growth rate (CAGR) for the global cyclotron market during the forecast period.. The report has been prepared after an extensive primary and secondary research. Primary research involves bulk of research efforts, wherein analysts carried out interviews with industry leaders and opinion makers. Extensive secondary research involves referring to key players product literature, annual reports, press releases, and relevant documents to understand the global cyclotron market.. Secondary research also includes Internet applications, statistical data from ...
TY - JOUR. T1 - Phase-space resolved measurement of 2nd harmonic ion cyclotron heating using FIDA tomography at the ASDEX Upgrade tokamak. T2 - Paper. AU - Weiland, M.. AU - Bilato, R.. AU - Geiger, B.. AU - Schneider, P. A.. AU - Tardini, G.. AU - Garcia-Muñoz, M.. AU - Ryter, F.. AU - Salewski, Mirko. AU - Zohm, H.. PY - 2017. Y1 - 2017. N2 - Recent upgrades to the FIDA (fast-ion D-alpha) diagnostic at ASDEX Upgrade allow to reconstruct the fast-ion phase space at several radial positions with decent energy and pitch resolution. These new diagnostic capabilities are applied to study the physics of 2nd harmonic ion cyclotron heating, which is a foreseen heating scenario for ITER. In particular, the acceleration of deuterium beam ions above the injection energy by absorption of ion cyclotron waves at the 2nd harmonic is investigated and compared to theoretical predictions by the TORIC-SSFPQL and TORIC-NUBEAM code packages. Furthermore, comparisons to other fast-ion diagnostics (neutron yield ...
The effect of ion cyclotron resonance heating (ICRH) on ((3)He)D plasmas at JET was studied with the time of flight optimized rate (TOFOR) spectrometer dedicated to 2.5 MeV dd neutron measurements. In internal transport barrier (ITB) plasma experiments with large (3)He concentrations (X((3)He),15%) an increase in neutron yield was observed after the ITB disappeared but with the auxiliary neutral beam injection and ICRH power still applied. The analysis of the TOFOR data revealed the formation of a high energy (fast) D population in this regime. The results were compared to other mode conversion experiments with similar X((3)He) but slightly different heating conditions. In this study we report on the high energy neutron tails originating from the fast D ions and their correlation with X((3)He) and discuss the light it can shed on ICRH-plasma power coupling mechanisms.. ...
Minimal staff and maintenance requirements. This is a fully-shielded system with integrated cyclotron, chemistry and quality control systems occupying minimal space in a hospital environment, and very easy to operate and maintain. The activities of the Model 200 can be remotely monitored from TBGs Support Department to assist in service and daily operation. These units are manufactured in USA using proprietary technologies.. TBG is planning to offer these units globally for medical and other institutions where availability of isotopes is often challenging - making it difficult to image patients on a timely basis to diagnose diseases at an early stage. TBG has extensive experience in the design, development and manufacture of unique accelerators, including cyclotrons for medical, research and industrial applications. TBG is in the process of expanding its manufacturing facilities in the USA to produce several cyclotron units on a monthly basis. TBG is the only cyclotron manufacturing company ...
Electromagnetic ion cyclotron (EMIC) waves and their role in governing proton populations in the ring current and radiation belt regions are of importance in understanding the dynamics of the Earths magnetosphere. The availability of SCATHA magnetic field and proton spectra data allowed us to study the electromagnetic proton cyclotron instability as a generation mechanism for EMIC waves and the relationship between EMIC waves and protons in the equatorial region of the magnetosphere. To identify EMIC waves and obtain wave power spectra from the SCATHA magnetic field data, we employed the fast Fourier transform and spectral analysis techniques. First, we studied the conditions under which the electromagnetic proton cyclotron instability acts as a generation mechanism for EMIC waves in the Earths magnetosphere. The results are consistent with those of previous studies and/or with theoretical expectations. Especially, the results show an inverse correlation between proton temperature anisotropy ...
An experimental campaign aiming to investigate electron cyclotron resonance (ECR) plasma X-ray emission has been recently carried out at the ECRISs-Electron Cyclotron Resonance Ion Sources laboratory of Atomki based on a collaboration between the Debrecen and Catania ECR teams. In a first series, the X-ray spectroscopy was performed through silicon drift detectors and high purity germanium detectors, characterizing the volumetric plasma emission. The on-purpose developed collimation system was suitable for direct plasma density evaluation, performed on-line during beam extraction and charge state distribution characterization. A campaign for correlating the plasma density and temperature with the output charge states and the beam intensity for different pumping wave frequencies, different magnetic field profiles, and single-gas/gas-mixing configurations was carried out. The results reveal a surprisingly very good agreement between warm-electron density fluctuations, output beam currents, and ...
Cisplatin is a potent anti-cancer drug, which functions by cross-linking adjacent DNA guanine residues. However within one day of injection, 65~98% of the platinum in the blood plasma is protein-bound. It is generally accepted that cisplatin binds to methionine and histidine residues, but what is often underappreciated is that platinum from cisplatin has a 2+ charge and can form up to four bonds. Thus, it has the potential to function as a cross-linker. In this report, the cross-linking ability of cisplatin is demonstrated by Fourier transform ion cyclotron resonance (FTICR) mass spectrometry (MS) with the use of standard peptides, the 16.8 kDa protein calmodulin (CaM), but was unsuccessful for the 64 kDa protein hemoglobin. The high resolution and mass accuracy of FTICR MS along with the high degree of fragmentation of large peptides afforded by collisionally activated dissociation (CAD) and electron capture dissociation (ECD) are shown to be a valuable means of characterizing cross-linking ...
Electron Induced dissociation (EID) is a method for fragmenting molecules species in mass spectrometry induced by interaction with (free) electrons (electron-induced dissociation, EID) at electron energies ranging from near 0 to >30 eV. The product-ion mass spectra exhibited EID originating from electronically excited even-electron precursor ions reduced radical cations formed by capture of low-energy electrons, and oxidized radical cations produced by interaction with high-energy electrons. Investigators have demonstrated that the spectra produced from high-energy EID EMS cell exhibit essentially the same qualitative structural information, i.e., amino acid side-chain (SC) losses and backbone cleavages, as observed with a Fourier-transform ion cyclotron resonance (FT-ICR) mass spectrometer. EMS cells incorporated into mass spectrometers could make tandem high-energy EID mass spectrometry more widely accessible for analysis of peptides, small singly charged molecules, pharmaceuticals, and ...
Dissociation of peptides induced by interaction with (free) electrons (electron-induced dissociation, EID) at electron energies ranging from near 0 to ,30 eV was carried out using a radio-frequency-free electromagnetostatic (EMS) cell retrofitted into a triple quadrupole mass spectrometer. The product-ion mass spectra exhibited EID originating from electronically excited even electron precursor ions, reduced radical cations formed by capture of low-energy electrons, and oxidized radical cations produced by interaction with high-energy electrons. The spectra demonstrate, within the limits of the triple quadrupoles resolving power, that high-energy EID product-ion spectra produced with an EMS cell exhibit essentially the same qualitative structural information, i.e. amino acid side-chain (SC) losses and backbone cleavages, as observed in high-energy EID spectra produced with a Fourier-transform ion cyclotron resonance (FT-ICR) mass spectrometer. The levels of fragmentation efficiency evident in ...
This course will introduce the basic concepts and terminology of mass spectrometry. The most important ionisation techniques used in mass spectrometry, including: electron ionisation, matrix assisted laser desorption/ionisation and atmospheric pressure ionisation techniques are introduced and details of the most common mass analysers including: quadrupoles, ion traps, time-of-flight (TOF), Orbitrap and Fourier-transform ion cyclotron resonance (FTICR) are provided.. The following topics are also covered: atomic and molecular masses, mass resolution, exact masses and isotopes, sample preparation, interfacing mass spectrometry with chromatographic techniques, ion detection, processing of mass spectral data, elementary spectral interpretation, and considerations for the mass spectrometry of large molecules. Using relevant, real-world examples such as common drugs and clinically relevant analytes, the course will illustrate both qualitative and quantitative applications of mass spectrometry.. The ...
The Cassady group uses mass spectrometry to study the gas-phase properties of biomolecules and to develop new techniques for analyzing these compounds. This work involves three higher performance mass spectrometers: a Bruker BioApex 7e Fourier transform ion cyclotron resonance spectrometer (FT-ICR or FTMS), a Bruker rapifleX dual time-of-flight (TOF-TOF) spectrometer (acquired in 2018), and a Bruker HCTultra PTM Discovery System high capacity quadrupole ion trap (QIT).. Our FT-ICR research deals with multiply-charged peptide and protein ions produced by electropsray ionization (ESI). Because FT-ICR is a trapping form of mass spectrometry, gas-phase biomolecular ions can be allowed to react with neutral molecules. The ions can also be fragmented, which is useful for obtaining structural information. Most of our recent work has centered on the reactivity and dissociation of deprotonated peptide ions. These ions are often formed in abundance from peptides with acidic residues, including phosphate ...
Autori: O. P. Balaj, C.-K. Siu, I. Balteanu, M. K. Beyer, and V. E. Bondybey. Editorial: Chem. Eur. J., 10, p.4822-4830, 2004.. Rezumat:. The gas-phase reactions of hydrated electrons with carbon dioxide and molecular oxygen were studied by Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometry. Both CO2 and O2 react efficiently with (H2O)n- because they possess low-lying empty pi* orbitals. The molecular CO2- and O2- anions are concurrently solvated and stabilized by the water ligands to form CO2-(H2O)n and O2-(H2O)n. Core exchange reactions are also observed, in which CO2-(H2O)n is transformed into O2-(H2O)n upon collision with O2. This is in agreement with the prediction based on density functional theory calculations that O2-(H2O)n clusters are thermodynamically favored with respect to CO2-(H2O)n. Electron detachment from the product species is only observed for CO2-(H2O)2, in agreement with the calculated electron affinities and solvation energies.. Cuvinte cheie: gas-phase ...
is the permeability of free space. Cyclotron radiation has a spectrum with its main spike at the same fundamental frequency as the particles orbit, and harmonics at higher integral factors. Harmonics are the result of imperfections in the actual emission environment, which also create a broadening of the spectral lines.[5] The most obvious source of line broadening is non-uniformities in the magnetic field;[6] as an electron passes from one area of the field to another, its emission frequency will change with the strength of the field. Other sources of broadening include collisional broadening[7] as the electron will invariably fail to follow a perfect orbit, distortions of the emission caused by interactions with the surrounding plasma, and relativistic effects if the charged particles are sufficiently energetic. When the electrons are moving at relativistic speeds, cyclotron radiation is known as synchrotron radiation. The recoil experienced by a particle emitting cyclotron radiation is ...
Background: Airway inflammation in cystic fibrosis (CF) is exaggerated and characterized by neutrophil-mediated tissue destruction, but its genesis and mechanisms remain poorly understood. To further define the pulmonary inflammatory response, we conducted a proteome-based screen of bronchoalveolar lavage fluid (BALF) collected from young children with and without CF experiencing endobronchial infection.. Methods: We collected BALF samples from 45 children younger than 5 years and grouped them according to the presence of respiratory pathogens: 1 x 105 colony-forming units (CFU)/mL BALF (18 and 12 samples with and without CF, respectively) and ,1 x 105 CFU/mL (23 and 15 samples). BALF proteins were analyzed with SELDI-TOF mass spectrometry (MS) and H4 ProteinChips®. Proteins were identified and characterized using trypsin digestion, tandem MS, Fourier transform ion cyclotron resonance MS, immunoblotting, and ELISA.. Results: The SELDI-TOF MS BALF profiles contained 53 unique, reliably detected ...
Best Cyclotron Systems Inc. is presently developing a 70 MeV cyclotron for radioisotope production and research purpose. The RF system comprises two separated resonators driven by independent amplifiers to allow for the phase and amplitude modulation technique to be applied for beam intensity modulation. The resonators are presently in the commissioning phase consisting of cold test measurements followed by high power commissioning in the cyclotron. Preliminary simulation results have been reported and are: 56MHz operation (fourth harmonic, half-wave resonator design), 60 to 70kV dee voltage, quality factor 8000 with the estimated dissipated power of 17kW per resonator. The electromagnetic modeling has been done with CST Microwave Studio. All simulation results showed a very conservative design with typical parameters for the energy and size of the resonators. The paper will present the measurement results on a cold test set-up configuration as well as the commissioning with high power in the ...
A cyclotron that includes a magnet yoke having a yoke body that surrounds an acceleration chamber. The cyclotron also includes a magnet assembly to produce magnetic fields to direct charged particles along a desired path. The magnet assembly is located in the acceleration chamber. The magnetic fields propagate through the acceleration chamber and within the magnet yoke, wherein a portion of the magnetic fields escapes outside of the magnet yoke as stray fields. The cyclotron also includes a vacuum pump that is coupled to the yoke body. The vacuum pump is configured to introduce a vacuum into the acceleration chamber. The magnet yoke is dimensioned such that the vacuum pump does not experience magnetic fields in excess of 75 Gauss.
March 23, 1965 R. J. BURLEIGH ETAL MAGNET CONSTRUCTION FOR A VARIABLE ENERGY CYCLOIRON 2 Sheets-Sheet 1 Filed Feb. 8. 1961 POWER SUPPLY m 0 C H N G A M INVENTORS RICHARD J. BURLEGH ELMER L. KELLY BY JOSEPH H. DORST CHARLES a. DOLS /4 MQ-QM ATTORNEY March 23, 1965 J, BURLEIGH ETAL 3,175,131 MAGNET CONSTRUCTION FOR A VARIABLE ENERGY CYCLOTRON Filed Feb. 8, 1961 2 Sheets-Sheet 2 Useful Rad/us O Radius of Pale, I RADIAL POSITION 4 INVENTORS RICHARD J. BURLE/GH ELMER L. KELLY BY JOSEPH H. DORST CHARLES G. DOLS ATTORNEY United States Patent 0 MAGNET CQNSTRUCTEON FOR A VARIABLE ENERGY CYCLOTRON Richard J. Burleigh, Elmer L. Kelly, Joseph H. Durst, and Qharles G. Dole, all of Berkeley, Calif., assignors to the United States of America as represented by the United States Atomic Energy Commission Filed Feb. 8, 1961, Ser. No. 87,980 1% tllaims. (Cl. 317-458) This invention relates to charge particle accelerators and more particularly to magnetic pole pieces for cyclotrons and like accelerators which ...
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We present timing and broad band spectral studies of the high-mass X-ray binary pulsar 4U 1909+07 using data from Suzaku observations during 2010 November 2-3. The pulse period of the pulsar is estimated to be 604.11 ± 0.14 s. Pulsations are seen in the X-ray light curve up to ∼70 keV. The pulse profile is found to be strongly energy-dependent: a complex, multi-peaked structure at low energy becomes a simple single peak at higher energy. We found that the 1-70 keV pulse-averaged continuum can be fit by the sum of a blackbody and a partial covering Negative and Positive power law with Exponential cutoff model. A weak iron fluorescence emission line at 6.4 keV was detected in the spectrum. An absorption-like feature at ∼44 keV was clearly seen in the residuals of the spectral fitting, independent of the continuum model adopted. To check the possible presence of a cyclotron resonance scattering feature (CRSF) in the spectrum, we normalized the pulsar spectrum with the spectrum of the Crab ...
We present the first measurements of cyclotron resonance of electrons and holes in bilayer graphene. In magnetic fields up to B=18 T, we observe four distinct intraband t
The cyclotron is the only practical source of many carrier-free radioisotopes. The preparation and radiochemical isolation of a number of these activities, produced in the 60-inch cyclotron of Crocker Laboratory, will be presented in this paper and in subsequent papers of this series. In most cases the carrier-free radioisotopes were prepared for use in biological systems and the final preparations were in the form of isotonic saline solutions at a range of pH from 5 to 8. The present paper reports the radiochemical isolation of carrier-free Sn{sup 113} and In{sup 114} produced by bombarding cadmium with 38 Mev alpha-particles. At this energy, Sn{sup 113} and In{sup 114} are produced in a thick target by the nuclear reactions; Cd{sup 110}({alpha},n)Sn{sup 113}, Cd{sup 111}({alpha},2n)Sn{sup 113}, Cd{sup 112}({alpha},3n)Sn{sup 113}, Cd{sup 111}({alpha},p)In{sup 114}, Cd{sup 112}({alpha},pn) In{sup 114}. The shorter-lived tin and indium activities together with the possible radioisotopes of silver