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https://www.readbyqxmd.com/read/28424429/the-volatile-molecule-signature-of-four-mycobacteria-species
#1
Theodore Mellors, Christiaan Rees, Wendy Wieland-Alter, C Fordham von Reyn, Jane E Hill
Mycobacteria are the leading cause of death from infectious disease worldwide and limitations in current diagnostics are hampering control efforts. In recent years, the use of small volatile molecules as diagnostic biomarkers for mycobacteria has shown promise for use in the rapid analysis of in vitro cultures as well as ex vivo diagnosis using breath or sputum. In this study, 18 strains from four mycobacteria species (Mycobacterium avium, M. bovis BCG, M. intracellulare and M. xenopi) were analyzed for the first time using two-dimensional gas chromatography time-of-flight mass spectrometry (GC×GC-TOFMS)...
April 20, 2017: Journal of Breath Research
https://www.readbyqxmd.com/read/28407955/influence-of-ripeness-and-maceration-of-the-grapes-on-levels-of-furan-and-carbonyl-compounds-in-wine-simultaneous-quantitative-determination-and-assessment-of-the-exposure-risk-to-these-compounds
#2
Laura Oliveira Lago, Karine Primieri Nicolli, Aline Biasoto Marques, Claudia Alcaraz Zini, Juliane Elisa Welke
The validated method based on the use of headspace solid phase microextraction (HS-SPME) coupled with the comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometric detection (GC×GC/TOFMS) proved to be appropriate for this first simultaneous quantitative determination of six toxic compounds (formaldehyde, acetaldehyde, ethyl carbamate, furan, furfural and acrolein) found in wines. Acetaldehyde and acrolein coeluted with other wine compounds, which indicated that difficulties could arise if only one-dimensional gas chromatography was used for the determination of these compounds...
September 1, 2017: Food Chemistry
https://www.readbyqxmd.com/read/28401661/chemical-discrimination-of-lubricant-marketing-types-using-dart-tofms
#3
Mark Maric, Lauren Harvey, Maren Tomcsak, Angelique Solano, Candice Bridge
RATIONALE: In comparison to other violent crimes, sexual assaults suffer from very low prosecution and conviction rates especially in the absence of DNA evidence. As a result, the forensic community needs to utilize other forms of trace contact evidence, like lubricant evidence, in order to provide a link between the victim and the assailant. METHODS: In this study, 90 personal bottled and condom lubricants from the three main marketing types, silicone-based, water-based and condoms, were characterized by direct analysis in real time-time of flight mass spectrometry (DART-TOFMS)...
April 12, 2017: Rapid Communications in Mass Spectrometry: RCM
https://www.readbyqxmd.com/read/28396122/evaluation-of-the-impact-of-gut-microbiota-on-uremic-solute-accumulation-by-a-ce-tofms-based-metabolomics-approach
#4
Eikan Mishima, Shinji Fukuda, Chikahisa Mukawa, Akinori Yuri, Yoshitomi Kanemitsu, Yotaro Matsumoto, Yasutoshi Akiyama, Noriko N Fukuda, Hiroki Tsukamoto, Kei Asaji, Hisato Shima, Koichi Kikuchi, Chitose Suzuki, Takehiro Suzuki, Yoshihisa Tomioka, Tomoyoshi Soga, Sadayoshi Ito, Takaaki Abe
Gut microbiota is involved in the metabolism of uremic solutes. However, the precise influence of microbiota to the retention of uremic solutes in CKD is obscure. To clarify this, we compared adenine-induced renal failure and control mice under germ-free or specific pathogen-free (SPF) conditions, examining the metabolite profiles of plasma, feces, and urine using a capillary electrophoresis time-of-flight mass spectrometry-based approach. Mice with renal failure under germ-free conditions demonstrated significant changes in plasma metabolites...
April 8, 2017: Kidney International
https://www.readbyqxmd.com/read/28389915/implementation-of-data-dependent-isotopologue-fragmentation-in-13-c-based-metabolic-flux-analysis
#5
Teresa Mairinger, Stephan Hann
A novel analytical approach based on liquid chromatography coupled to quadrupole time of flight mass spectrometry, employing data-dependent triggering for analysis of isotopologue and tandem mass isotopomer fractions of metabolites of the primary carbon metabolism was developed. The implemented QTOFMS method employs automated MS/MS triggering of higher abundant, biologically relevant isotopologues for generating positional information of the respective metabolite. Using this advanced isotopologue selective fragmentation approach enables the generation of significant tandem mass isotopomer data within a short cycle time without compromising sensitivity...
April 7, 2017: Analytical and Bioanalytical Chemistry
https://www.readbyqxmd.com/read/28365075/determination-of-endocrine-disrupting-chemicals-and-antiretroviral-compounds-in-surface-water-a-disposable-sorptive-sampler-with-comprehensive-gas-chromatography-time-of-flight-mass-spectrometry-and-large-volume-injection-with-ultra-high-performance-liquid
#6
Madelien Wooding, Egmont R Rohwer, Yvette Naudé
Many rural dwellers and inhabitants of informal settlements in South Africa are without access to treated water and collect untreated water from rivers and dams for personal use. Endocrine disrupting chemicals (EDCs) have been detected in surface water and wildlife of South Africa. EDCs are often present in complex environmental matrices at ultra-trace levels complicating detection thereof. We report a simplified multi-residue approach for the detection and quantification of EDCs, emerging EDCs, and antiretroviral drugs in surface water...
March 24, 2017: Journal of Chromatography. A
https://www.readbyqxmd.com/read/28343228/focal-brain-injury-associated-with-a-model-of-severe-hypoxic-ischemic-encephalopathy-in-nonhuman-primates
#7
Ryan M McAdams, Ronald J McPherson, Raj P Kapur, Sandra E Juul
Worldwide, hypoxic-ischemic encephalopathy (HIE) is a major cause of neonatal mortality and morbidity. To better understand the mechanisms contributing to brain injury and improve outcomes in neonates with HIE, better preclinical animal models that mimic the clinical situation following birth asphyxia in term newborns are needed. In an effort to achieve this goal, we modified our nonhuman primate model of HIE induced by in utero umbilical cord occlusion (UCO) to include postnatal hypoxic episodes, in order to simulate apneic events in human neonates with HIE...
March 25, 2017: Developmental Neuroscience
https://www.readbyqxmd.com/read/28340471/chemotaxonomic-studies-of-nine-paris-species-from-china-based-on-ultra-high-performance-liquid-chromatography-tandem-mass-spectrometry-and-fourier-transform-infrared-spectroscopy
#8
Yuanzhong Wang, Ehu Liu, Ping Li
Paris species, which contain steroid saponins, have been used as herb folk medicines in Asia. In the present study, a comprehensive strategy based on liquid chromatography-tandem mass spectrometry (LC-MS/MS) and Fourier transform infrared (FT-IR) spectroscopy was firstly proposed to evaluate the chemotaxonomic relationships of nine Paris species sampled from different geographical regions in China. Principle component analysis (PCA) based on FT-IR data revealed chemical similarities in term of the nine species and geographical regions, indicating the accumulation of metabolites affected by the combination of geographical factors and species...
March 18, 2017: Journal of Pharmaceutical and Biomedical Analysis
https://www.readbyqxmd.com/read/28340385/experimental-study-of-polyethylene-pyrolysis-and-combustion-over-hzsm-5-husy-and-mcm-41
#9
Que Huang, Changcheng Liu, Ruichao Wei, Jian Wang
The effects of temperatures, catalysts, and catalyst contents on polyethylene (PE) pyrolysis were investigated by using single-photon ionization time-of-flight mass spectrometry (SPI-TOFMS). The mass spectra of pyrolyzed PE and PE/catalysts from 300°C to 800°C illustrate that the pyrolysis reactions were apparently promoted and varied by introducing HZSM-5, HUSY, and MCM-41. As microporous catalysts, HZSM-5 and HUSY were found to accelerate the BTX formation at 400°C, which could not be observed for pure PE until 800°C...
March 14, 2017: Journal of Hazardous Materials
https://www.readbyqxmd.com/read/28328033/effects-of-molecular-weight-and-cationization-agent-on-the-sensitivity-of-bi-cluster-secondary-ion-mass-spectrometry
#10
Makiko Fujii, Rie Shishido, Takaya Satoh, Shigeru Suzuki, Jiro Matsuo
RATIONALE: Bi cluster secondary ion mass spectrometry (SIMS) is one of the most promising tools for precise analysis of synthetic polymers. However, the sensitivity in the high-mass region is still insufficient compared with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS). Accordingly, the effects of metal assistance (cationization agents) were investigated in this study. METHODS: To investigate the effects caused by varying the ionization agent, three different polyethylene glycol (PEG) samples were prepared, one with an Ag-deposited film, and two others mixed with Ag and Na, respectively...
July 30, 2016: Rapid Communications in Mass Spectrometry: RCM
https://www.readbyqxmd.com/read/28328023/identification-of-microorganisms-in-biofluids-of-individuals-with-periodontitis-and-chronic-kidney-disease-using-matrix-assisted-laser-desorption-ionization-time-of-flight-mass-spectrometry
#11
Levy Anderson César Alves, Rafael Celestino Souza, Taciana Mara Couto da Silva, Andreia Watanabe, Meriellen Dias, Maria Anita Mendes, Ana Lídia Ciamponi
RATIONALE: Chronic kidney disease (CKD) and periodontitis (PD) are important health issues. There is a large variety of microorganisms related to the pathogenesis of periodontitis, and optimising the time and the cost of laboratory assays to detect these organisms is highly valuable in the medical field. METHODS: Bacteria were isolated from saliva and oral biofilm of 30 adolescents and young adults with definite medical and dental diagnosis of CKD and PD, respectively, and proteins were extracted for microorganism identification by means of the matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS) technique...
May 30, 2016: Rapid Communications in Mass Spectrometry: RCM
https://www.readbyqxmd.com/read/28328018/abundance-correction-for-mass-discrimination-effects-in-polymer-mass-spectra
#12
Martin S Engler, Sarah Crotty, Markus J Barthel, Christian Pietsch, Ulrich S Schubert, Sebastian Böcker
RATIONALE: Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS) is frequently used to analyze homo- and copolymers, i.e. for computing copolymer fingerprints. However, the oligomer abundances are influenced by mass discrimination, i.e. mass- and composition-dependent ionization. We have developed a computational method to correct the abundance bias caused by the mass discrimination. METHODS: MALDI-TOFMS in combination with computational methods was used to investigate three random copolymers with different ratios of styrene and isoprene...
May 30, 2016: Rapid Communications in Mass Spectrometry: RCM
https://www.readbyqxmd.com/read/28315805/comprehensive-composition-of-creosote-using-comprehensive-two-dimensional-gas-chromatography-time-of-flight-mass-spectrometry-gcxgc-tofms
#13
Christopher Gallacher, Russell Thomas, Christopher Taylor, Richard Lord, Robert M Kalin
Creosote is a distillation product of coal tar and is widely used as wood preservative for railway sleepers, utility poles and for other applications. Creosote can have potentially negative effects on the environment and many of the components are toxic. This study presents the analysis of a Creosote sample from a former wood impregnation plant located in the UK. The sample was analysed using two dimensional gas chromatography time-of-flight mass spectrometry (GCxGC-TOFMS) and a database of compounds that could be detected was produced...
March 13, 2017: Chemosphere
https://www.readbyqxmd.com/read/28302985/application-of-laser-ionization-time-of-flight-mass-spectrometry-for-the-direct-measurement-of-a-silane-coupling-agent-in-slurries
#14
Takaaki Fujii, Tomohiro Uchimura
Laser ionization time-of-flight mass spectrometry (LI-TOFMS) was applied to the direct measurement of a silane coupling agent in slurries. In the present study, a slurry with dispersed TiO2 nanoparticles treated with phenyltriethoxysilane (PTES) was prepared. As a result, the peaks for PTES could be observed from the slurry sample containing unreacted PTES, and no peaks were observed from the slurry sample where unreacted PTES was removed by washing. This method can be used to directly analyze surface coating agents, such as PTES in slurries, and would be useful for obtaining a direct understanding of the characteristics of slurries...
2017: Analytical Sciences: the International Journal of the Japan Society for Analytical Chemistry
https://www.readbyqxmd.com/read/28302542/clinical-implications-associated-with-the-posttranslational-modification-induced-functional-impairment-of-albumin-in-oxidative-stress-related-diseases
#15
REVIEW
Hiroshi Watanabe, Tadashi Imafuku, Masaki Otagiri, Toru Maruyama
Recent research findings indicate that the posttranslational modification of human serum albumin (HSA) such as oxidation, glycation, truncation, dimerization and carbamylation is related to certain types of diseases. We report herein on a simple and rapid analytical method, using an ESI-TOFMS technique, that allows posttranslational modifications of HSA to be quantitatively and qualitatively evaluated with a high degree of sensitivity. In patients with chronic liver disease, chronic renal disease and diabetes mellitus, an increase in the level of oxidized Cys-34 of HSA accompanied by a decrease in the level of reduced Cys-34 was observed...
March 13, 2017: Journal of Pharmaceutical Sciences
https://www.readbyqxmd.com/read/28274593/in-depth-compositional-analysis-of-water-soluble-and-insoluble-organic-substances-in-fine-pm2-5-airborne-particles-using-ultra-high-resolution-15t-ft-icr-ms-and-gc%C3%A3-gc-tofms
#16
Jung Hoon Choi, Jijeong Ryu, Sodam Jeon, Jungju Seo, Yung-Hun Yang, Seung Pil Pack, Sungwook Choung, Kyoung-Soon Jang
Airborne particulate matter consisting of ionic species, salts, heavy metals and carbonaceous material is one of the most serious environmental pollutants owing to its impacts on the environment and human health. Although elemental and organic carbon compounds are known to be major components of aerosols, information on the elemental composition of particulate matter remains limited because of the broad range of compounds involved and the limits of analytical instruments. In this study, we investigated water-soluble and -insoluble organic compounds in fine (PM2...
March 5, 2017: Environmental Pollution
https://www.readbyqxmd.com/read/28256828/three-dimensional-reconstruction-of-the-tissue-specific-multielemental-distribution-within-ceriodaphnia-dubia-via-multimodal-registration-using-laser-ablation-icp-mass-spectrometry-and-x-ray-spectroscopic-techniques
#17
Stijn J M Van Malderen, Brecht Laforce, Thibaut Van Acker, Charlotte Nys, Maarten De Rijcke, Riet de Rycke, Michiel De Bruyne, Matthieu N Boone, Karel De Schamphelaere, Olga Borovinskaya, Björn De Samber, Laszlo Vincze, Frank Vanhaecke
In this work, the three-dimensional elemental distribution profile within the freshwater crustacean Ceriodaphnia dubia was constructed at a spatial resolution down to 5 μm via a data fusion approach employing state-of-the-art laser ablation-inductively coupled plasma-time-of-flight mass spectrometry (LA-ICP-TOFMS) and laboratory-based absorption microcomputed tomography (μ-CT). C. dubia was exposed to elevated Cu, Ni, and Zn concentrations, chemically fixed, dehydrated, stained, and embedded, prior to μ-CT analysis...
March 16, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28256041/metabolic-characterization-of-invaded-cells-of-the-pancreatic-cancer-cell-line-panc-1
#18
Mayumi Fujita, Kaori Imadome, Takashi Imai
We previously reported that about 0.4% of cells in the cultured human pancreatic cancer cell line, PANC-1, can invade matrigel during the transwell invasion assay, suggesting that these invaded PANC-1 cells may have specific characteristics to keep their invasive potential. To identify the metabolic characterization specific in the invaded PANC-1 cells, metabolome analysis of the invaded PANC-1 compared with the whole cultured PANC-1 was performed using CE-TOFMS, and concentrations of 110 metabolites were measured...
March 3, 2017: Cancer Science
https://www.readbyqxmd.com/read/28245644/quantitation-of-4-methyl-4-sulfanylpentan-2-one-4msp-in-hops-by-a-stable-isotope-dilution-assay-in-combination-with-gc%C3%A3-gc-tofms-method-development-and-application-to-study-the-influence-of-variety-provenance-harvest-year-and-processing-on-4msp-concentrations
#19
Klaas Reglitz, Martin Steinhaus
A stable isotope dilution assay was developed for quantitation of 4-methyl-4-sulfanylpentan-2-one (4MSP) in hops. The approach included the use of 4-((13)C)methyl-4-sulfanyl(1,3,5-(13)C3)pentan-2-one as internal standard, selective isolation of hop thiols by mercurated agarose, and GC×GC-TOFMS analysis. Application of the method to 53 different hop samples revealed 4MSP concentrations between <1 and 114 μg/kg. Notably high concentrations were associated with United States varieties such as Citra, Eureka, Simcoe, and Apollo, whereas 4MSP was absent from traditional German and English varieties...
March 8, 2017: Journal of Agricultural and Food Chemistry
https://www.readbyqxmd.com/read/28208275/comprehensive-three-dimensional-gas-chromatography-with-time-of-flight-mass-spectrometry
#20
Nathanial E Watson, H Daniel Bahaghighat, Ke Cui, Robert E Synovec
Development of comprehensive, three-dimensional (3D) gas chromatography with time-of-flight mass spectrometric detection (GC(3)/TOFMS) is described. This instrument provides four dimensions (4D) of chemical selectivity and includes significant improvements to total selectivity (mass spectrometric and chromatographic), peak identification, and operational temperature range relative to previous models of the GC(3) reported. The new instrumental design and data output are evaluated and illustrated via two samples, a 115-component test mixture and a diesel fuel spiked with several compounds, for the purpose of illustrating the chemical selectivity benefits of this instrumental platform...
February 7, 2017: Analytical Chemistry
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