cyclotrons

..Matrix-assisted laser desorption/ionization time-of-flight and electrospray ionization time-of-flight analysis of the tryptic peptides of mononitrated lysozyme identified the site of nitration as Tyr23...

..The application of ECD to the analysis of polymers, peptide nucleic acids, and oligonucleotides is also discussed...

..Here, we discuss both the advantages and difficulties encountered in the FT-ICR/MS metabolomics studies...

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..These experimental observations provide a range for the up- and down-regulations that are possible to study with electrospray ionization LC FT-ICR mass spectrometry...

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..In this article, the basic principles are highlighted, some of the techniques employed are described and examples of applications are provided, with particular respect being paid to the field of characterization of biomolecules...

..The experimental results are compared with data obtained using conventional quadrupole ion trap MS/MS and SORI-CID MS/MS in an ICR cell...

..The utility of this method for the analysis of polyols as single-component solutions, as mixtures, or in HPLC effluent (LC-MS analysis) is demonstrated...

..Sequential neutral losses of an aminosugar, a valine, a uridine, and an ester fatty acid from the muraymycin parent ions provided diagnostic fragments for characterization...

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..In addition to amino acid sequence information, the attachment site of the labile glycan moiety is determined, and also radical-site-induced fragmentations of the glycosidic bonds are observed...

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..The utility of activated ion ECD for the characterization of tryptic phosphopeptides was then demonstrated...

..Collision-induced dissociation experiments revealed the fragmentation patterns of the resorcarene skeleton and the differences in fragmentation induced by the guest ions...

..This method can be used for observing protein dynamics in a specific cell type, tissue, or in body fluids...

..A specially developed test with scrambled MS/MS data revealed that the amount of false-positive identifications was dramatically reduced by the combined use of CAD and ECD...

..It was found that 2-microm tip diameter resulted in more reproducible spectra than the larger tip diameters tested (6-20 microm)...

..This concept of remote experimentation opens new possibilities for scientific collaborations between expert scientists at different locations and allows the efficient use of this expensive instrumentation...

..In this way, the epitope extraction technique combined with mass spectrometric analysis is shown to be an excellent base for molecular screening of potential vaccine lead proteins...

..The different sugar core types exhibit different fragmentation patterns driven by the stability of the resulting fragments allowing the discrimination of isomeric glycans...

..The mechanisms of the reactions of peptides with P(OCH(3))(2)(+) and the dissociation of the (peptide + P - 2H)(+) ions were examined by using model peptides and molecular orbital calculations...

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..This approach offers an efficient way to cleave disulfide-bridged structures using low energy MS/MS, which leads to increased sequence coverage and more confidence in peptide or protein assignments...

..The predominantly automated nature of data acquisition and handling allowed for a relatively straightforward and fast procedure, which could compete with the mainstream alternative of nucleotide sequence determination...

..Our method needs only 2.5x10(3) cells for one injection and would be applicable to the determination of NeuGc in cell therapy products...

..Because of the low cost of implementation, the new source could potentially be applied to other forms of mass spectrometry, such as electrospray ionization-time-of-flight (ESI-TOF), which can benefit from internal mass calibration...

..They also indicate the form (unionized, zwitterionic, protonated, or deprotonated) which the biomolecule may take in a nonpolar environment...

..EID may find applications in analyzing singly charged molecular ions formed by matrix-assisted laser desorption ionization...

..The envelope deconvolution method is further illustrated by detection of deamidation in intact gammaS crystallin, a 20 904 Da protein, and discovery of the principal gammaS deamidation site...

..0 ppm to 1.1 ppm, with an average of -0.9 ppm. This method requires limited modification to ESI-FT-ICR mass spectrometers and is applicable for both positive and negative ionization modes...

..In contrast, infrared-MALDI-FT-ICR-MS did not produce fragmentation of molecular ions of Tyr-nitrated peptides...

..Nevertheless, the ToF instrument appears to discriminate better between unfolded and partially unfolded forms...

..The identified intermolecular cross-linking products will give further insight into calmodulin/adenylyl cyclase 8 interaction...

..Finally, high-resolution, accurate mass measurements determined that the V(NmA) (b(2)-71) ion results from losing a portion of valine from oxazolone V(NmA) b(2) ion, rather than cross-ring cleavage of the alternate diketopiperazine...

..This chapter covers the basic principles of operation of these instruments, including the trapping/manipulation/detection of ions and various approaches used to activate ions to perform tandem mass spectrometry experiments...

..6 J x mol(-1) x K(-1). Combining this value with experimental GB(1) leads to an 'experimental' proton affinity of 819.2 kJ x mol(-1), in close agreement with the G2 expectation...

..The results offer proof of concept for the CrossSearch strategy for analyzing conjugates and are the first to reveal a tertiary structural element of either homologous alpha or beta regulatory subunit of phosphorylase kinase...

..This is consistent with deprotonated carboxylic acid groups being involved in chromium(III) coordination and with chromium existing in the 3 + state in the gas-phase ions...

..The ion cloud evolution time-scale is inversely proportional to magnetic field. The number of ions needed for peak coalescence depends quadratically on the magnetic field...

..External ion accumulation performed at the optimal pressure resulted in an increase in both the spectrum acquisition rates and dynamic range...

..Using broadband detection, we were able to resolve ions with a difference of m/z 0.0064 to detect partially deamidated peptides formed either enzymatically or under acidic and basic conditions...

..We show that implementation of the DREAMS approach allows assignment of approximately 80% more peptide pairs, thus providing quantitative information for approximately 18,000 peptide pairs in a single analysis...

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..Further, a previously unstudied reaction of the nucleotide of thymine (T1) with charged phenyl radical was found to yield analogous products as the reaction with thymidine...

..The results suggest that LC/ECD-FTICRMS can be employed in the characterization of peptides in enzymatic digests of proteins or protein mixtures and identify and localize posttranslational modifications...

..Losses from arginine, histidine, and asparigine/glutamine can be used to ascertain their presence, as in the analysis of unknown peptides, particularly those with non-linear structures...

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..Amino acid sequence, structural flexibility and folding state of the peptides can be seen to play a part in the reactivity of such ions...

..The ECD rate improvement is not only due to the larger total electron current, but the larger emitting area as well...

..The available data have been used to calculate the molecular pair gas phase basicity of DMF and the 13 bases used and to estimate the dissociation energies of the bonds of the proton bridge in various proton bound heterodimers...

..The neutral loss involving the cleavage of two bonds was unanticipated and suggested a complex rearrangement process. A mechanism for the loss of SO(2) has been proposed...

..Libraries with more than 1000 different peptides could be screened in less than 20 min...

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..Parallel identification of proteins from complex mixtures down to low-femtomole levels makes nano-HPLC/nano-ESI-FTICRMS an attractive approach for proteome analysis...

..Here we have used titration calorimetry, analytical ultracentrifugation, and electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry to obtain evidence that such distinguishable subsites exist...

..e., neutralization of the fragment ions, might be a significant event for limiting the intensity of the fragment ions...

..The method is robust-it succeeds even with partial tryptic digestion, partial Edman derivatization, and partial MS/MS IRMPD cleavage. Improved efficiency and automation should be straightforward...

..Arg8-vasotocin isolated from the pineal gland of rainbow trout is detected, demonstrating the ability of FT-ICR to detect and identify a true endogenous biological analyte...

..This was rationalized through the lower degree of charge solvation on the backbone compared to polypeptides. Combination of both CAD and ECD data is advantageous, as these techniques produce cleavages at different sites...

..There followed a series of cyclotrons, synchrotrons and linear accelerators, culminating in the BEVALAC, which provided the first source of very heavy ..

..PET) is a rapidly expanding clinical modality worldwide thanks to the availability of compact medical cyclotrons and automated chemistry for the production of radiopharmaceuticals...

..Centers that do not have cyclotrons rely on generator-produced radioisotopes for assessment of regional myocardial perfusion with positron emission ..

..In addition to the now classical proton therapy equipments, using synchrotrons or cyclotrons as accelerators, new solutions have been proposed, claiming to be more compact and less expensive...

..With 26 MeV alpha particles, available with compact cyclotrons, the first reaction required an enriched 70Ge target of sodium metagermanate to give a production yield of 1 mCi/..

..makes it attractive to use in busy nuclear medicine departments, particularly those with limited access to cyclotrons. The recent clinical experience with (68)Ga-peptides includes imaging neuroendocrine tumours particularly ..

..studies in which fast neutrons were delivered using modern, hospital-based, high-energy, isocentric-capable cyclotrons. In locally advanced squamous cell head and neck cancers, neutrons showed no convincing advantage over photons...

..This, on the other side, opens a question of their availability on the routine basis and at reasonable prices. This matter is also discussed in the present review...

..predictions to the current state of the art, we have broken this into four key areas; commercially available cyclotrons, costs of operating cyclotron facilities, the emergence of compact accelerators, and the cyclotron production of ..

..It was expected that this new regulation would mediate the installation of clearance systems in Japan. In order to assess the current situation of radiation safety management in PET institutions, we conducted a nationwide survey...

..Early use of neutrons from radioactive sources and from cyclotrons led to a need to define risk for such exposures...

Laser plasma acceleration can potentially replace large and expensive cyclotrons or synchrotrons for radiotherapy with protons and ions...

..of machines are considered: (1) medical electron linacs for 'conventional' radiation therapy, (2) low energy cyclotrons for production of radionuclides mainly for medical diagnostics and (3) medium energy cyclotrons and synchrotrons ..

..are produced in a number of ways: as by-products of fission, by means of neutron activation, by cyclotrons, and by generators. These methods produce isotopes with both desirable and undesirable properties...

..With the increased availability of small, low-energy cyclotrons and improvements in both cyclotron targetry and purification chemistries, the use of "nonstandard" ..

..Hatanaka et al., in Proceedings of the 17th International Conference on Cyclotrons and Their Applications, Tokyo, Japan, 18-22 October 2004, pp...

..The accelerator types are a combination of synchrotrons, cyclotrons, and linear accelerators; some carry advanced features such as respiration gating, intensity modulation, and ..

..For patients with sarcomas, radiotherapy can be used as neoadjuvant, adjuvant, or primary local therapy, depending on the site and type of sarcoma, the surgical approach, and the efficacy of chemotherapy...

..Recommendations have also been made to reduce personal exposure while handling the target foil rupture condition such as the use of L-Bench near the target area and participation of experienced personnel...

..radioactivity of the cyclotron itself and structures is an important issue in decommissioning of medical compact cyclotrons. To obtain basic data on the actual operational conditions of cyclotrons, we performed nationwide survey...

..in interventional radiology (IR), in vitro biomedical research and radiopharmaceutical production around cyclotrons. Besides the fact that many of the staff members, involved in these applications, are not measurably exposed, ..

..From stand-alone PET/CT systems with on-site cyclotrons, mostly in the government sector, the modality has matured to such an extent that, today, the majority of the ..

..other than FDG are significantly more limited in their availability and are limited to PET centers with on-site cyclotrons. However, these additional agents open the door to many additional studies, including more specific tumor-..

New low-cost, high-power proton cyclotrons open the opportunity for a novel precision search for CP violation in the light neutrino sector...

..The first step of this process is the isotope production by small cyclotrons. The synthons made from the isotopes react with the precursor of the given radiopharmaceutical...

..This route is therefore superior for current medical cyclotrons. Irradiation of a reusable 80Se copper selenide target also yielded multi-millicurie amounts of 80mBr, and ..

..operation and negative (vs positive) ion acceleration (and extraction) are explained, as they make dedicated PET cyclotrons a simple, reliable, and suitable tool...

..SPECT) tracers are lacking, but with the increase in the number of available PET (or PET/CT) cameras and cyclotrons thanks to the clinical successes of PET in oncology, PET may become widespread enough to overcome this ..

Production of (38)Cl and (34m)Cl via the (d, α) reaction on natural argon and (36)Ar reveal medical cyclotrons' ability to supply these isotopes in small quantities...

..high energy LINAC X-rays modified in comparison to their classical use in external radiation therapy, and, more rarely, protons produced in cyclotrons. Several teams world-wide are still perfecting and refining this developing technique.

..The proposed production energy range is too high for small cyclotrons but large quantities of 124I can be produced with medium-sized commercial machines.

..are produced in good yields at low energy cyclotrons while for production of some other radionuclides (e.g. 52Fe, 73Se, 83Sr, etc...

..UDP-GlcNAc is an activated building block for protein glycosylation, which is an important regulatory mechanism in the development of many prominent human diseases including cancer and diabetes...

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..This review covers our recent advances to scale-up the production of the heavy halogens and transition metals as feed-stock for non-conventional PET tracers that are currently attracting increased attention in oncology...

..25 (ranging from 1.25 to 3.5). Because the results reported here are not quantitative, an average ratio cannot be determined...

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..Ninety six cyclotrons in US hospitals and distribution centers currently bombard stable enriched O-18 water targets with protons to ..

..Removing more heat allows full use of the available proton beam current in the installed base of PET cyclotrons, thus at least doubling the production of O-18(p,n)F-18 for FDG (feasibility established by Phase I prototype ..

..Although it has the lowest energy of the cyclotrons we considered, it has high current output and relatively low shielding requirements and it will meet our current ..

..means that C-DTBZ clinical studies are only feasible at a limited number of centers with on-site cyclotrons. Since the PET isotope F has a 110 min...

..This project is multidisiplinary and pulls together several distinguished collaborators with focused research projects that will benefit directly from H/D exchange with high-resolution mass analysis. ..

..This project is multidisiplinary and pulls together several distinguished collaborators with focused research projects that will benefit directly from H/D exchange with high-resolution mass analysis. ..

..q the best way to incorporate knowled,qe into the desi,qn and testing of novel drugs.] ..

..Furthermore, these labeling methods should be applicable to other internalizing mAbs and fragments, increasing the potential impact of this work. ..

..In the future, we expect that the lower-risk treatments will result in fewer second cancers and this will translate into longer, higher-quality lives for survivors of childhood cancer (presently 270,000 persons in the United States). ..

..Further, this research advances the general understanding of aging and various diseases, including cancer. ..

..At present, this experimental capability is non-existent. ..

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..Finally, different methods to trap radicals are evaluated for possible application in prevention of free radical damage caused by such conditions as Alzheimer s disease and strokes. ..

..The proposed in vitro studies include characterization of binding, internalization and catabolism; the proposed in vivo studies include evaluation of tissue distribution, dosimetry, catabolism as well as therapeutic efficacy. ..

..This paradigm will be ultimately employed to design target-specific radical warheads that can be generated photolytically for site-specific tumor. ..

..The results will be used as reference materials in retrospective studies as well as ongoing clinical trials. ..

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