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Mass Spectrometry

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https://www.readbyqxmd.com/read/28149705/secondary-ion-mass-spectrometry-analysis-of-renal-cell-carcinoma-with-electrospray-droplet-ion-beams
#1
Satoshi Ninomiya, Kentaro Yoshimura, Lee Chuin Chen, Sen Takeda, Kenzo Hiraoka
Tissue samples from renal cell carcinoma patients were analyzed by electrospray droplet ion beam-induced secondary ion mass spectrometry (EDI/SIMS). Positively- and negatively-charged secondary ions were measured for the cancerous and noncancerous regions of the tissue samples. Although specific cancerous species could not be found in both the positive and negative secondary ion spectra, the spectra of the cancerous and noncancerous tissues presented different trends. For instance, in the m/z range of 500-800 of the positive secondary ion spectra for the cancerous tissues, the intensities for several m/z values were lower than those of the m/z+2 peaks (indicating one double bond loss for the species), whereas, for the noncancerous tissues, the inverse trend was obtained...
2017: Mass Spectrometry
https://www.readbyqxmd.com/read/28101442/determination-of-optimal-vapor-pressure-data-by-the-second-and-third-law-methods
#2
Kunihisa Nakajima
Though equilibrium vapor pressures are utilized to determine thermodynamic properties of not only gaseous species but also condensed phases, the obtained data often disagree by a factor of 100 and more. A new data analysis method is proposed using the so-called second and third law procedures to improve accuracy of vapor pressure measurements. It was found from examination of vapor pressures of cesium metaborate and silver that the analysis of the difference between the second and third law values can result in determination of an optimal data set...
2016: Mass Spectrometry
https://www.readbyqxmd.com/read/28101441/reduced-sampling-size-with-nanopipette-for-tapping-mode-scanning-probe-electrospray-ionization-mass-spectrometry-imaging
#3
Tsuyoshi Kohigashi, Yoichi Otsuka, Ryo Shimazu, Takuya Matsumoto, Futoshi Iwata, Hideya Kawasaki, Ryuichi Arakawa
Mass spectrometry imaging (MSI) with ambient sampling and ionization can rapidly and easily capture the distribution of chemical components in a solid sample. Because the spatial resolution of MSI is limited by the size of the sampling area, reducing sampling size is an important goal for high resolution MSI. Here, we report the first use of a nanopipette for sampling and ionization by tapping-mode scanning probe electrospray ionization (t-SPESI). The spot size of the sampling area of a dye molecular film on a glass substrate was decreased to 6 μm on average by using a nanopipette...
2016: Mass Spectrometry
https://www.readbyqxmd.com/read/28101440/high-spatial-resolution-laser-desorption-ionization-mass-spectrometry-imaging-of-organic-layers-in-an-organic-light-emitting-diode
#4
Yuko Tachibana, Yoji Nakajima, Tsuguhide Isemura, Kiyoshi Yamamoto, Takaya Satoh, Jun Aoki, Michisato Toyoda
To improve the durability of organic materials in electronic devices, an analytical method that can obtain information about the molecular structure directly from specific areas on a device is desired. For this purpose, laser desorption/ionization mass spectrometry imaging (LDI-MSI) is one of the most promising methods. The high spatial resolution stigmatic LDI-MSI with MULTUM-IMG2 in the direct analysis of organic light-emitting diodes was shown to obtain a detailed mass image of organic material in the degraded area after air exposure...
2016: Mass Spectrometry
https://www.readbyqxmd.com/read/27900236/identification-of-two-sulfated-cholesterol-metabolites-found-in-the-urine-of-a-patient-with-niemann-pick-disease-type-c-as-novel-candidate-diagnostic-markers
#5
Masamitsu Maekawa, Kaoru Omura, Shoutaro Sekiguchi, Takashi Iida, Daisuke Saigusa, Hiroaki Yamaguchi, Nariyasu Mano
In the urine of a Niemann-Pick disease type C (NPC) patient, we have identified three characteristic intense peaks that have not been observed in the urine of a 3β-hydroxysteroid-Δ(5)-C27-steroid dehydrogenase deficiency patient or a healthy infant and adult. Based on accurate masses of the protonated molecules, we focused on two of them as candidate NPC diagnostic markers. Two synthesized authentic preparations agreed with the two compounds found in NPC patient urine in regard to both chromatographic behavior and accurate masses of the deprotonated molecules...
2016: Mass Spectrometry
https://www.readbyqxmd.com/read/27900235/technical-challenges-in-mass-spectrometry-based-metabolomics
#6
Fumio Matsuda
Metabolomics is a strategy for analysis, and quantification of the complete collection of metabolites present in biological samples. Metabolomics is an emerging area of scientific research because there are many application areas including clinical, agricultural, and medical researches for the biomarker discovery and the metabolic system analysis by employing widely targeted analysis of a few hundred preselected metabolites from 10-100 biological samples. Further improvement in technologies of mass spectrometry in terms of experimental design for larger scale analysis, computational methods for tandem mass spectrometry-based elucidation of metabolites, and specific instrumentation for advanced bioanalysis will enable more comprehensive metabolome analysis for exploring the hidden secrets of metabolism...
2016: Mass Spectrometry
https://www.readbyqxmd.com/read/27900234/n-terminal-derivatization-with-structures-having-high-proton-affinity-for-discrimination-between-leu-and-ile-residues-in-peptides-by-high-energy-collision-induced-dissociation
#7
Atsushi Kitanaka, Masahiro Miyashita, Ayumi Kubo, Takaya Satoh, Michisato Toyoda, Hisashi Miyagawa
De novo sequencing is still essential in the identification of peptides and proteins from unexplored organisms whose sequence information is not available. One of the remaining problems in de novo sequencing is discrimination between Leu and Ile residues. The discrimination is possible based on differences in side chain fragmentation between Leu and Ile under high-energy collision-induced dissociation (HE-CID) conditions. However, this is observed only when basic residues, such as Arg and Lys, are present near the N- or C-terminal end...
2016: Mass Spectrometry
https://www.readbyqxmd.com/read/27843740/verification-of-ribosomal-proteins-of-aspergillus-fumigatus-for-use-as-biomarkers-in-maldi-tof-ms-identification
#8
Sayaka Nakamura, Hiroaki Sato, Reiko Tanaka, Takashi Yaguchi
We have previously proposed a rapid identification method for bacterial strains based on the profiles of their ribosomal subunit proteins (RSPs), observed using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). This method can perform phylogenetic characterization based on the mass of housekeeping RSP biomarkers, ideally calculated from amino acid sequence information registered in public protein databases. With the aim of extending its field of application to medical mycology, this study investigates the actual state of information of RSPs of eukaryotic fungi registered in public protein databases through the characterization of ribosomal protein fractions extracted from genome-sequenced Aspergillus fumigatus strains Af293 and A1163 as a model...
2016: Mass Spectrometry
https://www.readbyqxmd.com/read/27800293/multi-stage-mass-spectrometry-of-poly-vinyl-pyrrolidone-and-its-vinyl-succinimide-copolymer-formed-upon-exposure-to-sodium-hypochlorite
#9
Thierry Fouquet, Masaki Torimura, Hiroaki Sato
The degradation routes of poly(vinyl pyrrolidone) (PVP) exposed to sodium hypochlorite (bleach) have been previously investigated using chemical analyses such as infrared spectroscopy. So far, no reports have proposed mass spectrometry (MS) as an alternative tool despite its capability to provide molecular and structural information using its single stage electrospray (ESI) or matrix assisted laser desorption ionization (MALDI) and multi stage (MS (n) ) configurations, respectively. The present study thus reports on the characterization of PVP after its exposure to bleach by high resolution MALDI spiralTOF-MS and Kendrick mass defect analysis providing clues as to the formation of a vinyl pyrrolidone/vinyl succinimide copolymeric degradation product...
2016: Mass Spectrometry
https://www.readbyqxmd.com/read/27656337/a-method-for-simultaneous-determination-of-25-hydroxyvitamin-d3-and-its-3-sulfate-in-newborn-plasma-by-lc-esi-ms-ms-after-derivatization-with-a-proton-affinitive-cookson-type-reagent
#10
Tatsuya Higashi, Mai Yokota, Ayaka Goto, Kenji Komatsu, Takahiro Sugiura, Shoujiro Ogawa, Mamoru Satoh, Fumio Nomura
A method for the simultaneous determination of 25-hydroxyvitamin D3 [25(OH)D3] and its 3-sulfate [25(OH)D3S] in newborn plasma, which is expected to be helpful in the assessment of the vitamin D status, using stable isotope-dilution liquid chromatography/electrospray ionization-tandem mass spectrometry (LC/ESI-MS/MS) has been developed and validated. The plasma was pretreated based on the deproteinization and solid-phase extraction, then subjected to derivatization with 4-(4-dimethylaminophenyl)-1,2,4-triazoline-3,5-dione (DAPTAD)...
2016: Mass Spectrometry
https://www.readbyqxmd.com/read/27563510/photochemical-reactions-of-aminonaphthols-caused-by-laser-desorption-ionization
#11
Keishiro Nagoshi, Kazuma Inatomi, Issey Osaka, Mitsuo Takayama
The formation of monomeric and dimeric ions of seven different aminonaphthols (ANLs) has been studied by using laser desorption/ionization (LDI) with a nitrogen laser. The positive-ion data of all the ANLs merely showed molecular ion M(·+) without protonated molecule [M+H](+), while 1-amino-2-naphthol (1,2-ANL) and 2-amino-1-naphthol (2,1-ANL) showed an intense dimeric ion [2 M-2H2O+H](+). The negative-ion data showed deprotonated molecule [M-H](-) in common, while the spectra of 1,2-ANL, 2,1-ANL and 8-amino-2-naphthol (8,2-ANL) accompanied an intense peak corresponding to negative molecular ion M(·-) and the 8,2-ANL and 4-amino-1-naphthol (4,1-ANL) accompanied dehydrogenated anion [M-2H](·-)...
2016: Mass Spectrometry
https://www.readbyqxmd.com/read/27446770/metabolomic-analysis-of-gingival-crevicular-fluid-using-gas-chromatography-mass-spectrometry
#12
Miho Ozeki, Takenori Nozaki, Jun Aoki, Takeshi Bamba, Kirk R Jensen, Shinya Murakami, Michisato Toyoda
Periodontitis is one of the most prevalent threats to oral health as the most common cause of tooth loss. In order to perform effective treatment, a clinical test that detect sites where disease activity is high and predicts periodontal tissue destruction is strongly desired, however, it is still difficult to prognose the periodontal tissue breakdown on the basis of conventional methods. The aim of this study is to examine the usefulness of gas chromatography/mass spectrometry (GC/MS), which could eventually be used for on-site analysis of metabolites in gingival crevicular fluid (GCF) in order to objectively diagnose periodontitis at a molecular level...
2016: Mass Spectrometry
https://www.readbyqxmd.com/read/27313979/rapid-and-accurate-identification-of-animal-species-in-natural-leather-goods-by-liquid-chromatography-mass-spectrometry
#13
Yukari Izuchi, Tsuneo Takashima, Naoya Hatano
The demand for leather goods has grown globally in recent years. Industry revenue is forecast to reach $91.2 billion by 2018. There is an ongoing labelling problem in the leather items market, in that it is currently impossible to identify the species that a given piece of leather is derived from. To address this issue, we developed a rapid and simple method for the specific identification of leather derived from cattle, horses, pigs, sheep, goats, and deer by analysing peptides produced by the trypsin-digestion of proteins contained in leather goods using liquid chromatography/mass spectrometry...
2016: Mass Spectrometry
https://www.readbyqxmd.com/read/27313978/identification-of-anthropogenic-compounds-in-urban-environments-and-evaluation-of-automated-methods-for-reading-fragmentation-a-case-of-river-water
#14
Atsushi Yamamoto, Naoko Matsumoto, Hideya Kawasaki, Ryuichi Arakawa
A workflow based on liquid chromatography/high-resolution mass spectrometry (LC/HR-MS) was applied for the identification of compounds in urban environments. Substances extracted by solid-phase extraction from river water were wholly analyzed by LC/HR-MS without any purification. Fragmentation in collision-induced dissociation was manually studied for the 20 most intense ions in positive- and negative-ion electrospray ionization with accurate mass determination at a resolution of 100,000. Sixteen anthropogenic compounds in the extract were identified and confirmed using standard reference reagents...
2016: Mass Spectrometry
https://www.readbyqxmd.com/read/27162707/maldi-in-source-decay-of-protein-the-mechanism-of-c-ion-formation
#15
REVIEW
Mitsuo Takayama
The in-source decay (ISD) phenomenon, the fragmentation at an N-Cα bond of a peptide backbone that occurs within several tens of nanoseconds in the ion-source in matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS), is discussed from the standpoints of the discovery and early publications dealing with MALDI-ISD, the formation of c-ions in energy-sudden desorption/ionization methods, the formation of radical species in a MALDI, model construction for ISD, and matrix materials that are suitable for use in MALDI-ISD...
2016: Mass Spectrometry
https://www.readbyqxmd.com/read/27162706/determination-of-detection-limits-and-quantitation-limits-for-compounds-in-a-database-of-gc-ms-by-fumi-theory
#16
Shinya Nakashima, Yuzuru Hayashi
The aim of this paper is to propose a stochastic method for estimating the detection limits (DLs) and quantitation limits (QLs) of compounds registered in a database of a GC/MS system and prove its validity with experiments. The approach described in ISO 11843 Part 7 is adopted here as an estimation means of DL and QL, and the decafluorotriphenylphosphine (DFTPP) tuning and retention time locking are carried out for adjusting the system. Coupled with the data obtained from the system adjustment experiments, the information (noise and signal of chromatograms and calibration curves) stored in the database is used for the stochastic estimation, dispensing with the repetition measurements...
2016: Mass Spectrometry
https://www.readbyqxmd.com/read/26819913/conifer-derived-monoterpenes-and-forest-walking
#17
Kazuhiro Sumitomo, Hiroaki Akutsu, Syusei Fukuyama, Akiho Minoshima, Shin Kukita, Yuji Yamamura, Yoshiaki Sato, Taiki Hayasaka, Shinobu Osanai, Hiroshi Funakoshi, Naoyuki Hasebe, Masao Nakamura
Conifer and broadleaf trees emit volatile organic compounds in the summer. The major components of these emissions are volatile monoterpenes. Using solid phase microextraction fiber as the adsorbant, monoterpenes were successfully detected and identified in forest air samples. Gas chromatography/mass chromatogram of monoterpenes in the atmosphere of a conifer forest and that of serum from subjects who were walking in a forest were found to be similar each other. The amounts of α-pinene in the subjects became several folds higher after forest walking...
2015: Mass Spectrometry
https://www.readbyqxmd.com/read/26819912/when-api-mass-spectrometry-meets-super-atmospheric-pressure-ion-sources
#18
Lee Chuin Chen
In a tutorial paper on the application of free-jet technique for API-MS, John Fenn mentioned that "…for a number of years and a number of reasons, it has been found advantageous in many situations to carry out the ionization process in gas at pressures up to 1000 Torr or more" (Int. J. Mass Spectrom. 200: 459-478, 2000). In fact, the first ESI mass spectrometer constructed by Yamashita and Fenn had a counter-flow curtain gas source at 1050 Torr (ca. 1.4 atm) to sweep away the neutral (J. Phys. Chem. 88: 4451-4459, 1984)...
2015: Mass Spectrometry
https://www.readbyqxmd.com/read/26819911/development-of-an-imaging-mass-spectrometry-technique-for-visualizing-localized-cellular-signaling-mediators-in-tissues
#19
Yuki Sugiura, Kurara Honda, Makoto Suematsu
In vivo concentrations of cellular signaling mediators such as inflammatory mediators are normally maintained at very low levels due to their strong ability to induce a biological response. The production, diffusion, and decomposition of such mediators are spatio-temporally regulated. Therefore, in order to understand biochemical basis of disease progression and develop new therapeutic strategies, it is important to understand the spatiotemporal dynamics of the signaling mediators in vivo, during the progression of disorders, e...
2015: Mass Spectrometry
https://www.readbyqxmd.com/read/26819910/middle-down-and-chemical-proteomic-approaches-to-reveal-histone-h4-modification-dynamics-in-cell-cycle-label-free-semi-quantification-of-histone-tail-peptide-modifications-including-phosphorylation-and-highly-sensitive-capture-of-histone-ptm-binding-proteins
#20
Kazuki Yamamoto, Yoko Chikaoka, Gosuke Hayashi, Ryosuke Sakamoto, Ryuji Yamamoto, Akira Sugiyama, Tatsuhiko Kodama, Akimitsu Okamoto, Takeshi Kawamura
Mass spectrometric proteomics is an effective approach for identifying and quantifying histone post-translational modifications (PTMs) and their binding proteins, especially in the cases of methylation and acetylation. However, another vital PTM, phosphorylation, tends to be poorly quantified because it is easily lost and inefficiently ionized. In addition, PTM binding proteins for phosphorylation are sometimes resistant to identification because of their variable binding affinities. Here, we present our efforts to improve the sensitivity of detection of histone H4 tail peptide phosphorylated at serine 1 (H4S1ph) and our successful identification of an H4S1ph binder candidate by means of a chemical proteomics approach...
2015: Mass Spectrometry
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