Read by QxMD icon Read

mass spec

Johannes T van Elteren, Martin Šala, Vid S Šelih
This work focuses on the structural similarity (SSIM) index as a tool for optimization of the perceived visual image quality obtainable by continuous scanning 2D LA-ICPMS bioimaging, but also other mass spec imaging techniques may benefit from this approach. This index quantifies the differences between a distorted image and a reference image based on parameters associated with luminance, contrast, and noise. Since reference images are not normally available, a protocol was developed to virtually apply distortion-related information introduced by the LA-ICPMS imaging system to a reference image of one's choice...
April 9, 2018: Analytical Chemistry
Richard D Adams, Emmanuel J Kiprotich, Mark D Smith
Reaction of Os3(CO)10(NCMe)2 with the triosmium furyne complex Os3(CO)9(μ3,η2-C4H2O)(μ-H)2, 1 yielded the bis-triosmium complex 2 containing a bridging furyenyl ligand by CH activation at the uncoordinated C-C double bond. Heating 2 led to additional CH activation with formation of the first furdiyne C4O ligand in the complex Os3(CO)9(μ-H)2(μ3-η2-2,3-μ3-η2-4,5-C4O)Os3(CO)9(μ-H)2, 3. The furdiyne ligand in 3 was subsequently ring-opened and decarbonylated to yield products 4 and 5 containing novel bridging C3 ligands...
March 21, 2018: Chemical Communications: Chem Comm
Taeik Hwang, Eunyoung Noh, Ji Hye Jeong, Sung-Kwan Park, Dongwoo Shin, Hoil Kang
A sensitive and specific high-performance liquid chromatography-quadrupole time-of-flight-mass spectrometry (LC-QTOF-MS) method combined with liquid chromatography-tandem mass spectrometry (LC-MS/MS) was developed for the determination of grayanotoxins I and III in dietary supplements and homemade wine. Grayanotoxins I and III were successfully extracted using solid-phase extraction cartridges, characterized by LC-QTOF-MS, and quantitated by LC-MS/MS. The LC-MS/MS calibration curves were linear over concentrations of 10-100 ng/mL (grayanotoxin I) and 20-400 ng/mL (grayanotoxin III)...
February 28, 2018: Journal of Agricultural and Food Chemistry
X J Feng, J T Zhang, M R Moldover, I Yang, M D Plimmer, H Lin
This article describes the accurate determination of the molar mass M of a sample of argon gas used for the determination of the Boltzmann constant. The method of one of the authors (Moldover et al 1988 J. Res. Natl. Bur. Stand. 93 85-144) uses the ratio of the square speed of sound in the gas under analysis and in a reference sample of known molar mass. A sample of argon that was isotopically-enriched in 40 Ar was used as the reference, whose unreactive impurities had been independently measured. The results for three gas samples are in good agreement with determinations by gravimetric mass spectrometry; (〈 M acoustic / M mass-spec 〉 - 1) = (-0...
June 2017: Metrologia
Huaming Sheng, Weijuan Tang, Jinshan Gao, James S Riedeman, Guannan Li, Tiffany M Jarrell, Matthew R Hurt, Linan Yang, Priya Murria, Xin Ma, John J Nash, Hilkka I Kenttämaa
Seven synthesized G-lignin oligomer model compounds (ranging in size from dimers to an octamer) with 5-5 and/or β-O-4 linkages, and three synthesized S-lignin model compounds (a dimer, trimer, and tetramer) with β-O-4 linkages, were evaporated and deprotonated using negative-ion mode ESI in a linear quadrupole ion trap/Fourier transform ion cyclotron resonance mass spectrometer. The collision-activated dissociation (CAD) fragmentation patterns (obtained in MS2 and MS3 experiments, respectively) for the negative ions were studied to develop a procedure for sequencing unknown lignin oligomers...
December 19, 2017: Analytical Chemistry
Amaroju Suresh, Singireddi Srinivasarao, Napiórkowska Agnieszka, Augustynowicz-Kopeć Ewa, Mallika Alvala, Christian Lherbet, Kondapalli Venkata Gowri Chandra Sekhar
We prepared fifty various 9H-fluorenone based 1,2,3-triazole analogues varied with NH, -S-, and -SO2 - groups using click chemistry. The target compounds were characterized by routine analytical techniques, 1 H, 13 CNMR, mass, elemental, single-crystal XRD (8a) and screened for in vitro antitubercular activity against Mycobacterium tuberculosis (MTB) H37Rv strain and two "wild" strains Spec. 210 and Spec. 192 and MIC50 was determined. Further, the compounds were evaluated for MTB InhA inhibition study as well...
June 2018: Chemical Biology & Drug Design
Khalfalla Awedat, Ikhlas Abdel-Qader, James R Springstead
The high dimensionality and noisy spectra of Mass Spectrometry (MS) data are two of the main challenges to achieving high accuracy recognition. The objective of this work is to produce an accurate prediction of class content by employing compressive sensing (CS). Not only can CS significantly reduce MS data dimensionality, but it will also allow for full reconstruction of original data. We are proposing a weighted mixing of L1- and L2-norms via a regularization term as a classifier within compressive sensing framework...
March 2017: Biomedical Signal Processing and Control
Laura Bree, Chiara Bergamino, Ronan Mullins, Pamela Kelly, Robert Shiel
CASE SUMMARY: A 14-year-old neutered male Siamese cat was presented with a 3 month history of lethargy, inappetence, dehydration, hindlimb ataxia and intermittent proprioceptive deficits in the hindlimbs. Physical examination revealed low body condition score (1.75/5), pallor and bilateral basilar grade II/VI systolic heart murmur. Neurological examination revealed hindlimb ataxia, severe atrophy of the hindlimb musculature, intermittent hindlimb proprioceptive deficits and normoreflexia...
July 2017: JFMS Open Reports
James A Dunne, David A Richards, Hsin-Wei Chen
Determination of135 Cs/137 Cs atom ratios has the potential to be a powerful tool for nuclear forensics and monitoring environmental processes. We present optimized chemical separation techniques and thermal ionization mass spectrometry (TIMS) protocols to obtain precise135 Cs/137 Cs atom ratios for a range of environmental sample types. We use a combination of double AMP-PAN separation and Sr-spec resin column purification to yield excellent separation from the alkali metals (Rb separation factor > 600), which normally suppress ionization of Cs...
November 1, 2017: Talanta
Ling-Yu Guo, Hai-Feng Su, Mohamedally Kurmoo, Xing-Po Wang, Quan-Qin Zhao, Shui-Chao Lin, Chen-Ho Tung, Di Sun, Lan-Sun Zheng
A family of six triple-decker complexes, {(MX)2[(pz)4]3} (Hpz = 4-nitropyrazole, MX = NaCl, 1; NaBr, 2; NaI, 3; KCl, 4; KBr, 5, and KI, 6), exhibiting inclusion of halides into inverse 12-metallacrown-4 [inv-(12-MCCu(I),pz-4)] array has been realized. Single-crystal X-ray crystallography of each compound reveals a common structural feature consisting of four Cu(I) ions bonded by four pz to form a square metallomacrocycle comprising four metal centers and eight N atoms, thus giving an inv-[12-MCCu(I),pz-4] motif...
June 1, 2017: ACS Applied Materials & Interfaces
Jian Ma, Cameron P Casey, Xueyun Zheng, Yehia M Ibrahim, Christopher S Wilkins, Ryan S Renslow, Dennis G Thomas, Samuel H Payne, Matthew E Monroe, Richard D Smith, Justin G Teeguarden, Erin S Baker, Thomas O Metz
Motivation: Drift tube ion mobility spectrometry coupled with mass spectrometry (DTIMS-MS) is increasingly implemented in high throughput omics workflows, and new informatics approaches are necessary for processing the associated data. To automatically extract arrival times for molecules measured by DTIMS at multiple electric fields and compute their associated collisional cross sections (CCS), we created the PNNL Ion Mobility Cross Section Extractor (PIXiE). The primary application presented for this algorithm is the extraction of data that can then be used to create a reference library of experimental CCS values for use in high throughput omics analyses...
September 1, 2017: Bioinformatics
Jianmin Wang, Yingli Liu, Lijuan Tang, Sufen Qi, Yingjun Mi, Dianwu Liu, Qingbao Tian
The present study aimed to identify candidate substrates of ubiquitin-specific protease (USP)13 using two-dimensional fluorescence difference gel electrophoresis (2D-DIGE). USP13 is a well-characterized member of the USP family, which regulates diverse cellular functions by cleaving ubiquitin from ubiquitinated protein substrates. However, existing studies indicate that USP13 has no detectable hydrolytic activity in vitro. This finding implies that USP13 likely has different substrate specificity. In this study, a USP cleavage assay was performed using two different types of model substrates (glutathione S-transferase-Ub52 and ubiquitin-β-galactosidase) to detect the deubiquitinating enzyme (DUB) activity of USP13...
July 2017: International Journal of Molecular Medicine
Tesla Yudhistira, Sandip V Mulay, Kyung Jin Lee, Youngsam Kim, Hee-Sung Park, David G Churchill
The role of fluorescent molecules in diagnosis, treatment as well as in biomedical research has great current medicinal significance and is the focus of concentrated effort across the scientific research spectrum. Related research continues to reveal new practical sensing systems that bear enhanced features for interfacing of substituted molecules with biological systems. As part of an effort to better understand chalcogenide systems, a new dithiomaleimide BODIPY (BDP-NGM) probe has been designed, synthesized and characterized...
August 4, 2017: Chemistry, An Asian Journal
Jin-Young Cho, Hyoung-Joo Lee, Seul-Ki Jeong, Young-Ki Paik
Mass spectrometry (MS) is a widely used proteome analysis tool for biomedical science. In an MS-based bottom-up proteomic approach to protein identification, sequence database (DB) searching has been routinely used because of its simplicity and convenience. However, searching a sequence DB with multiple variable modification options can increase processing time, false-positive errors in large and complicated MS data sets. Spectral library searching is an alternative solution, avoiding the limitations of sequence DB searching and allowing the detection of more peptides with high sensitivity...
December 1, 2017: Journal of Proteome Research
Shraddha S Vadvalkar, Satoshi Matsuzaki, Craig A Eyster, Jennifer R Giorgione, Lee B Bockus, Caroline S Kinter, Michael Kinter, Kenneth M Humphries
Alterations in mitochondrial function contribute to diabetic cardiomyopathy. We have previously shown that heart mitochondrial proteins are hyperacetylated in OVE26 mice, a transgenic model of type 1 diabetes. However, the universality of this modification and its functional consequences are not well established. In this study, we demonstrate that Akita type 1 diabetic mice exhibit hyperacetylation. Functionally, isolated Akita heart mitochondria have significantly impaired maximal (state 3) respiration with physiological pyruvate (0...
March 17, 2017: Journal of Biological Chemistry
Madoka Chinen, Elissa P Lei
Argonaute (AGO) proteins play a central role in the RNA interference (RNAi) pathway, which is a cytoplasmic mechanism important for post-transcriptional regulation of gene expression. In Drosophila, AGO2 also functions in the nucleus to regulate chromatin insulator activity and transcription. Although there are a number of studies focused on AGO2 function, the regulation of AGO2 turnover is not well understood. We found that mutation of T1149 or R1158 in the conserved PIWI domain causes AGO2 protein instability, but only T1149 affects RNAi activity...
February 12, 2017: Biochemical and Biophysical Research Communications
Ruben Epping, Ulrich Panne, Jana Falkenhagen
Statistical ethylene oxide (EO) and propylene oxide (PO) copolymers of different monomer compositions and different average molar masses additionally containing two kinds of end groups (FTD) were investigated by ultra high pressure liquid chromatography under critical conditions (UP-LCCC) combined with electrospray ionization time-of flight mass spectrometry (ESI-TOF-MS). Theoretical predictions of the existence of a critical adsorption point (CPA) for statistical copolymers with a given chemical and sequence distribution1 could be studied and confirmed...
February 7, 2017: Analytical Chemistry
Alperen Serdaroglu, Stephan A Müller, Ute Schepers, Stefan Bräse, Wilko Weichert, Stefan F Lichtenthaler, Peer-Hendrik Kuhn
The secretome, the entirety of all soluble proteins either being secreted or proteolytically released by a cell, plays a key role in inter-cellular communication of multi-cellular organisms. Pathological alterations contribute to diseases such as hypertension, cancer, autoimmune disorders or neurodegenerative diseases. Hence, studying disease-related perturbations of the secretome and the secretome itself covers an important aspect of cellular physiology. We recently developed the secretome protein enrichment with click sugars (SPECS) method that enables the analysis of secretomes of in vitro cell cultures even in the presence of FCS with MS...
March 2017: Proteomics
Camille Maumet, Tibor Auer, Alexander Bowring, Gang Chen, Samir Das, Guillaume Flandin, Satrajit Ghosh, Tristan Glatard, Krzysztof J Gorgolewski, Karl G Helmer, Mark Jenkinson, David B Keator, B Nolan Nichols, Jean-Baptiste Poline, Richard Reynolds, Vanessa Sochat, Jessica Turner, Thomas E Nichols
Only a tiny fraction of the data and metadata produced by an fMRI study is finally conveyed to the community. This lack of transparency not only hinders the reproducibility of neuroimaging results but also impairs future meta-analyses. In this work we introduce NIDM-Results, a format specification providing a machine-readable description of neuroimaging statistical results along with key image data summarising the experiment. NIDM-Results provides a unified representation of mass univariate analyses including a level of detail consistent with available best practices...
December 6, 2016: Scientific Data
Pere Ràfols, Dídac Vilalta, Jesús Brezmes, Nicolau Cañellas, Esteban Del Castillo, Oscar Yanes, Noelia Ramírez, Xavier Correig
Mass spectrometry imaging (MSI) is a label-free analytical technique capable of molecularly characterizing biological samples, including tissues and cell lines. The constant development of analytical instrumentation and strategies over the previous decade makes MSI a key tool in clinical research. Nevertheless, most MSI studies are limited to targeted analysis or the mere visualization of a few molecular species (proteins, peptides, metabolites, or lipids) in a region of interest without fully exploiting the possibilities inherent in the MSI technique, such as tissue classification and segmentation or the identification of relevant biomarkers from an untargeted approach...
November 9, 2016: Mass Spectrometry Reviews
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"