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https://www.readbyqxmd.com/read/28432653/analyzing-glycopeptide-isomers-by-combining-differential-mobility-spectrometry-with-electron-and-collision-based-tandem-mass-spectrometry
#1
J Larry Campbell, Takashi Baba, Chang Liu, Catherine S Lane, J C Yves Le Blanc, James W Hager
Differential mobility spectrometry (DMS) has been employed to separate isomeric species in several studies. Under the right conditions, factors such as separation voltage, temperature, the presence of chemical modifiers, and residence time can combine to provide unique signal channels for isomeric species. In this study, we examined a set of glycopeptide isomers, MUC5AC-3 and MUC5AC-13, which bear an N-acetyl-galactosamine (GalNAc) group on either threonine-3 or threonine-13. When analyzed as a mixture, the resulting MS and MS/MS spectra yield fragmentation patterns that cannot discern these convolved species...
April 21, 2017: Journal of the American Society for Mass Spectrometry
https://www.readbyqxmd.com/read/28431777/lomefloxacin
#2
Reem I Al-Wabli
Lomefloxacin is a second-generation difluorinated broad-spectrum quinolone antibiotic. It is used for the treatment of bronchitis, urinary tract infection, conjunctivitis, otitis externa, and otitis media. A comprehensive profile was performed on lomefloxacin including nomenclature, formulae, elemental composition appearance, and physical characteristics. Spectral methods including ultraviolet spectrum, vibrational spectrum, (1)H and (13)C nuclear magnetic resonance one- and two-dimensional spectra, and mass spectrum were used for both identification and analysis of the drug...
2017: Profiles of Drug Substances, Excipients, and related Methodology
https://www.readbyqxmd.com/read/28431775/cinacalcet-hydrochloride
#3
Gamal A E Mostafa, Abdullah A Al-Badr
Cinacalcet hydrochloride is a calcimimetic agent that increases the sensitivity to the extracellular calcium of the calcium-sensing receptors of the parathyroid gland which regulates parathyroid hormone secretion. This comprehensive profile on cinacalcet hydrochloride starts with a description: nomenclature, formulae, chemical structure, elemental composition, and appearance. The uses and applications of the drug are included. The methods of preparation of cinacalcet hydrochloride are described and their respective schemes are outlined...
2017: Profiles of Drug Substances, Excipients, and related Methodology
https://www.readbyqxmd.com/read/28430435/cu-in-halide-perovskite-cihp-solar-absorbers
#4
Xin-Gang Zhao, Dongwen Yang, Yuanhui Sun, Tianshu Li, Lijun Zhang, Liping Yu, Alex Zunger
The long-term chemical instability and the presence of toxic Pb in otherwise stellar solar absorber APbX3 made of organic molecules on the A site and halogens for X have hindered their large-scale commercialization. Previously explored ways to achieve Pb-free halide perovskites involved replacing Pb(2+) with other similar M(2+) cations in ns(2) electron configuration, e.g., Sn(2+) or by Bi(3+) (plus Ag(+)), but unfortunately this showed either poor stability (M = Sn) or weakly absorbing oversized indirect gaps (M = Bi), prompting concerns that perhaps stability and good optoelectronic properties might be contraindicated...
April 21, 2017: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/28430236/spectral-characterization-and-discrimination-of-synthetic-fibers-with-near-infrared-hyperspectral-imaging-system
#5
Xiaoke Jin, Hafeezullah Memon, Wei Tian, Qinli Yin, Xiaofang Zhan, Chengyan Zhu
Synthetic fibers account for about half of all fiber usage, with applications in every textile field. The phenomenon of fiber composition not matching the label harms consumer interests and impedes market development. Hyperspectral imaging technology as a potential technique can be utilized to discriminate mass synthetic fibers rapidly and nondestructively and achieves the functions that traditional Fourier transform infrared instruments do not have. On the basis of investigating the impact of dope-dyeing and wrapping processes on spectra, the spectral features (from 900 to 2500 nm) of six categories of synthetic fibers were extracted with a hyperspectral imaging system...
April 20, 2017: Applied Optics
https://www.readbyqxmd.com/read/28429299/participation-of-c-h-protons-in-the-dissociation-of-a-proton-deficient-dipeptide
#6
Damodar Koirala, Sabyasachy Mistry, Paul G Wenthold
The dissociation of anionic dipeptides Phe*Gly and GlyPhe*, where Phe* refers to sulfonated phenyl alanine, has been investigated by using ion trap mass spectrometry. The dipeptides undergo collision-induced dissociation (CID) to give the same products, indicating that they rearrange to a common structure before dissociation. The rearrangement does not occur with the dipeptide methyl esters. The structures of the b2 ions were investigated to determine the effect that having a remote, anionic site has on product formation...
April 20, 2017: Journal of the American Society for Mass Spectrometry
https://www.readbyqxmd.com/read/28427570/high-resolution-mass-spectrometry-based-screening-reveals-lipophilic-toxins-in-multiple-trophic-levels-from-the-north-sea
#7
Gabriel Orellana, Lieven Van Meulebroek, Maarten De Rijcke, Colin R Janssen, Lynn Vanhaecke
Lipophilic marine biotoxins, which are mainly produced by small dinoflagellates, are increasingly detected in coastal waters across the globe. As these producers are consumed by zooplankton and shellfish, the toxins are introduced, bioaccumulated and possibly biomagnified throughout marine food chains. Recent research has demonstrated that ultra-high performance liquid chromatography coupled to high-resolution mass spectrometry (UHPLC-HRMS) is an excellent tool to detect marine toxins in algae and seafood. In this study, UHPLC-HRMS was used to screen lipophilic marine biotoxins in organisms from different trophic levels of the Belgian coastal zone ecosystem...
April 2017: Harmful Algae
https://www.readbyqxmd.com/read/28426182/usefulness-and-accuracy-of-maldi-tof-mass-spectrometry-as-a-supplementary-tool-to-identify-mosquito-vector-species-and-to-invest-in-development-of-international-database
#8
F N Raharimalala, T M Andrianinarivomanana, A Rakotondrasoa, J M Collard, S Boyer
Arthropod-borne diseases are important causes of morbidity and mortality. The identification of vector species relies mainly on morphological features and/or molecular biology tools. The first method requires specific technical skills and may result in misidentifications, and the second method is time-consuming and expensive. The aim of the present study is to assess the usefulness and accuracy of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) as a supplementary tool with which to identify mosquito vector species and to invest in the creation of an international database...
April 20, 2017: Medical and Veterinary Entomology
https://www.readbyqxmd.com/read/28425293/cosensitized-porphyrin-system-for-high-performance-solar-cells-with-tof-sims-analysis
#9
Wenjun Wu, Huaide Xiang, Wei Fan, Jinglin Wang, Haifeng Wang, Xin Hua, Zhaohui Wang, Yi-Tao Long, He Tian, Wei-Hong Zhu
Up to date, development of organic sensitizers has been predominately focused on light harvesting, HOMO and LUMO energy levels, and electron transferring process. In contrast, their adsorption mode as well as dynamic loading behaviour onto nanoporous TiO2 is rarely considered. Herein we have employed the time of flight secondary ion mass spectrometry (TOF-SIMS) to take insight into the competitive dye adsorption mode and kinetics in cosensitized porphyrin system. Using the novel porphyrin dye FW-1 and D-A-π-A featured dye WS-5, the different bond-breaking mode in TOF-SIMS and dynamic dye-loading amount during the coadsorption process are well compared with two different anchoring groups such as benzoic acid and cyanoacrylic acid...
April 20, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28424252/comparison-of-saramis-4-12-and-ivd-3-0-vitek-ms-matrix-assisted-laser-desorption-ionization-time-of-flight-mass-spectrometry-for-identification-of-mycobacteria-from-solid-and-liquid-culture-media
#10
Caroline Leyer, Guillaume Gregorowicz, Faiza Mougari, Laurent Raskine, Emmanuelle Cambau, Dominique de Briel
During the last decade, many publications studied the matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) for mycobacterial identification. Diverse and contradictory results indicated that optimal level for routine testing has not been reached yet. This work aimed to assess Vitek MS through two distinct versions, Saramis v4.12 RUO and the IVD v3.0, under conditions close to routine laboratory practice. Overall, 111 mycobacterial isolates were submitted to protein extraction and same spectra were matched against both databases...
April 19, 2017: Journal of Clinical Microbiology
https://www.readbyqxmd.com/read/28423217/in-vitro-discrimination-of-wound-associated-bacteria-by-volatile-compound-profiling-using-selected-ion-flow-tube-mass-spectrometry
#11
Elisabeth Alice Slade, Robin Michael Statham Thorn, Andrew M Lovering, Amber Young, Darren Michael Reynolds
AIMS: To determine if bacterial species responsible for clinically relevant wound infection produce specific volatile profiles that would allow their speciation. METHODS AND RESULTS: Selected-Ion Flow Tube-Mass Spectrometry in full mass scan mode was used to analyse headspace gases produced by wound-associated bacteria grown in vitro, so as to enable identification of bacterial volatile product ion profiles in the resulting mass spectra. Applying multivariate statistical analysis (hierarchical clustering and principal component analysis) to the resultant mass spectra enabled clear speciation...
April 19, 2017: Journal of Applied Microbiology
https://www.readbyqxmd.com/read/28422067/synthesis-characterization-antimicrobial-and-antiproliferative-activity-evaluation-of-cu-ii-co-ii-zn-ii-ni-ii-and-pt-ii-complexes-with-isoniazid-derived-compound
#12
Elena Pahonțu, Diana-Carolina Ilieș, Sergiu Shova, Camelia Oprean, Virgil Păunescu, Octavian Tudorel Olaru, Flavian Ștefan Rădulescu, Aurelian Gulea, Tudor Roșu, Doina Drăgănescu
Hydrazone complexes of Cu(II), Co(II), Zn(II), Ni(II) and Pt(II) with N-isonicotinoyl-N'-(3-metoxy-2 hydroxybenzaldehyde)-hydrazone (HL) were synthesized and characterized by different physico-chemical techniques including elemental and thermal analysis, magnetic susceptibility measurements, molar electric conductivity, as well as IR (infrared), ¹H-NMR and (13)C-NMR (hydrogen and carbon nuclear magnetic resonance, UV-Vis (ultraviolet-visible), FAB (fast atom bombardment), EPR (electron paramagnetic resonance), and mass spectroscopies...
April 19, 2017: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/28421756/reactions-of-copper-and-silver-cations-with-carbon-dioxide-an-infrared-photodissociation-spectroscopic-and-theoretical-study
#13
Zhi Zhao, Xiangtao Kong, Dong Yang, Qinqin Yuan, Hua Xie, Hongjun Fan, Jijun Zhao, Ling Jiang
The reaction of copper and silver cations with carbon dioxide was studied by mass-selected infrared photodissociation spectroscopy. Quantum chemical calculations were performed on these products, which aided the experimental assignments of the infrared spectra and helped to elucidate the geometrical and electronic structures. The Cu(+) and Ag(+) cations bind to an oxygen atom of CO2 in an end-on configuration via a charge-quadrupole electrostatic interaction in the [M(CO2)n](+) complexes. The formation of oxide-carbonyl and carbonyl-carbonate structures is not favored for the interaction of CO2 with Cu(+) and Ag(+)...
April 21, 2017: Journal of Physical Chemistry. A
https://www.readbyqxmd.com/read/28421405/differential-fragmentation-of-mobility-selected-glycans-via-ultraviolet-photodissociation-and-ion-mobility-mass-spectrometry
#14
Kelsey A Morrison, Brian H Clowers
The alternative dissociation pathways initiated by ultraviolet photodissociation (UVPD) compared with collision-induced dissociation (CID) may provide useful diagnostic fragments for biomolecule identification, including glycans. However, underivatized glycans do not commonly demonstrate strong UV absorbance, resulting in low fragmentation yields for UVPD spectra. In contrast to UVPD experiments that leverage covalent modification of glycans, we detail the capacity of metal adduction to yield comparatively rich UVPD fragmentation patterns and enhance separation factors for an isomeric glycan set in a drift tube ion mobility system...
April 18, 2017: Journal of the American Society for Mass Spectrometry
https://www.readbyqxmd.com/read/28421209/excitation-dynamics-involving-homogeneous-multistate-interactions-one-and-two-color-vmi-and-rempi-of-hbr
#15
Helgi Rafn Hróðmarsson, Andreas Kartakoullis, Dimitris Zaouris, Pavle Glodic, Huasheng Wang, Peter C Samartzis, Ágúst Kvaran
Velocity map imaging (VMI) data and mass resolved REMPI spectra are complementarily utilized to elucidate the involvement of homogeneous multistate interactions in excited state dynamics of HBr. The H(1)Σ(+)(v' = 0) and E(1)Σ(+)(v' = 1) Rydberg states and the V(1)Σ(+)(v'= m + 7) and V(1)Σ(+)(v'= m + 8) ion-pair states are explored as a function of rotational quantum number in the two-photon excitation region of 79 100-80 700 cm(-1). H(+) and Br(+) images were recorded by one- as well as two-color excitation schemes...
April 19, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28420285/dry-powders-for-the-inhalation-of-ciprofloxacin-or-levofloxacin-combined-with-a-mucolytic-agent-for-cystic-fibrosis-patients
#16
Yagmur Akdag Cayli, Selma Sahin, Francesca Buttini, Anna Giulia Balducci, Serena Montanari, Imran Vural, Levent Oner
OBJECTIVE: This study aimed to design and characterize an inhalable dry powder of ciprofloxacin or levofloxacin combined with the mucolytics acetylcysteine and dornase alfa for the management of pulmonary infections in patients with cystic fibrosis. METHODS: Ball milling, homogenization in isopropyl alcohol, and spray drying processes were used to prepare dry powders for inhalation. Physico-chemical characteristics of the dry powders were assessed via thermogravimetric analysis, differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FT-IR), X-ray diffractometry, and scanning electron microscopy...
April 19, 2017: Drug Development and Industrial Pharmacy
https://www.readbyqxmd.com/read/28420234/raman-spectroscopy-of-fish-oil-capsules-pufa-quantitation-plus-detection-of-ethyl-esters-and-oxidation
#17
Daniel P Killeen, Susan N Marshall, Elaine J Burgess, Keith C Gordon, Nigel B Perry
Fish oils are the primary dietary source of ω-3 polyunsaturated fatty acids (PUFA), but these compounds are prone to oxidation, and commercial fish oil supplements sometimes contain less PUFA than claimed. These supplements are predominantly sold in softgel capsules. In this work we show that Fourier-Transform (FT)-Raman spectra of fish oils (n=5) and ω-3 PUFA concentrates (n=6) can be acquired directly through intact softgel (gelatin) capsules. These spectra could be used to rapidly distinguish supplements containing ethyl esters from those triacylglyceride oils...
April 19, 2017: Journal of Agricultural and Food Chemistry
https://www.readbyqxmd.com/read/28420113/synthesis-and-spectral-properties-of-meso-arylbacteriochlorins-including-insights-into-essential-motifs-of-their-hydrodipyrrin-precursors
#18
Muthyala Nagarjuna Reddy, Shaofei Zhang, Han-Je Kim, Olga Mass, Masahiko Taniguchi, Jonathan S Lindsey
Synthetic bacteriochlorins-analogues of bacteriochlorophylls, Nature's near-infrared absorbers-are attractive for diverse photochemical studies. meso-Arylbacteriochlorins have been prepared by the self-condensation of a dihydrodipyrrin-carbinol or dihydrodipyrrin-acetal following an Eastern-Western (E-W) or Northern-Southern (N-S) joining process. The bacteriochlorins bear a gem-dimethyl group in each pyrroline ring to ensure stability toward oxidation. The two routes differ in the location of the gem-dimethyl group at the respective 3- or 2-position in the dihydrodipyrrin, and the method of synthesis of the dihydrodipyrrin...
April 14, 2017: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/28419111/time-resolved-and-label-free-monitoring-of-extracellular-metabolites-by-surface-enhanced-raman-spectroscopy
#19
Victoria Shalabaeva, Laura Lovato, Rosanna La Rocca, Gabriele C Messina, Michele Dipalo, Ermanno Miele, Michela Perrone, Francesco Gentile, Francesco De Angelis
Metabolomics is an emerging field of cell biology that aims at the comprehensive identification of metabolite levels in biological fluids or cells in a specific functional state. Currently, the major tools for determining metabolite concentrations are mass spectrometry coupled with chromatographic techniques and nuclear magnetic resonance, which are expensive, time consuming and destructive for the samples. Here, we report a time resolved approach to monitor metabolite dynamics in cell cultures, based on Surface Enhanced Raman Scattering (SERS)...
2017: PloS One
https://www.readbyqxmd.com/read/28418253/species-level-discrimination-of-psychrotrophic-pathogenic-and-spoilage-gram-negative-raw-milk-isolates-using-a-combined-maldi-tof-ms-proteomics-bioinformatics-based-approach
#20
Nuwan R Vithanage, Thomas Richard Yeager, Jeevana Bhongir, Snehal R Jadhav, Chaminda Senaka Ranadheera, Enzo A Palombo, Nivedita Datta
Identification of psychrotrophic pathogenic and spoilage Gram-negative bacteria using rapid and reliable techniques is important in commercial milk processing, as these bacteria can produce heat-resistant proteases and act as post-processing contaminants in pasteurised milk. Matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) is a proven technology for identification of bacteria in food, however may require optimisation for identification of pathogenic and spoilage bacteria in milk and dairy products...
April 18, 2017: Journal of Proteome Research
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