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https://www.readbyqxmd.com/read/28339664/adult-paget-s-disease-of-bone-a-review
#1
Stephen Paul Tuck, Robert Layfield, Julie Walker, Babitha Mekkayil, Roger Francis
Adult PD of bone is the second commonest metabolic bone condition after osteoporosis. The condition is characterized by increased bone cell activity, with bone-resorbing osteoclasts often larger and containing more nuclei than normal, and osteoblasts producing increased amounts of disorganized bone. This leads to expanded bone of poor quality possessing both sclerotic and lytic areas. PD of bone has a strong genetic element, with a family history being noted in 10-20% of cases. A number of genetic defects have been found to be associated with the condition...
February 17, 2017: Rheumatology
https://www.readbyqxmd.com/read/28334553/a-multi-matrix-hilic-ms-ms-method-for-the-quantitation-of-endogenous-small-molecule-neurological-biomarker-n-acetyl-aspartic-acid-naa
#2
Dewakar Sangaraju, Sheerin K Shahidi-Latham, Braydon L Burgess, Brian Dean, Xiao Ding
A multi-matrix hydrophilic interaction liquid chromatography tandem mass spectrometric method (HILIC-MS/MS) was developed for the quantitation of N-Acetyl Aspartic acid (NAA) using stable isotope labeled internal standard, D3-NAA in various biological matrices such as human plasma, human CSF, mouse plasma, brain and spinal cord. A high throughput 96-well plate format supported liquid extraction (SLE) procedure was developed and used for sample preparation. Mass spectrometric analysis of NAA was performed using selected reaction monitoring transitions in positive electrospray ionization mode...
March 14, 2017: Journal of Pharmaceutical and Biomedical Analysis
https://www.readbyqxmd.com/read/28334113/you-are-what-you-get-from-your-fungi-nitrogen-stable-isotope-patterns-in-epipactis-species
#3
Julienne M-I Schiebold, Martin I Bidartondo, Peter Karasch, Barbara Gravendeel, Gerhard Gebauer
Background and Aims: Partially mycoheterotrophic plants are enriched in 13 C and 15 N compared to autotrophic plants. Here, it is hypothesized that the type of mycorrhizal fungi found in orchid roots is responsible for variation in 15 N enrichment of leaf tissue in partially mycoheterotrophic orchids. Methods: The genus Epipactis was used as a case study and carbon and nitrogen isotope abundances of eight Epipactis species, fungal sporocarps of four Tuber species and autotrophic references were measured...
February 22, 2017: Annals of Botany
https://www.readbyqxmd.com/read/28333468/alkyl-chain-length-dependent-structural-and-orientational-transformations-of-water-at-alcohol-water-interfaces-and-its-relevance-to-atmospheric-aerosols
#4
Jahur A Mondal, Vinu Namboodiri, Mathi Pandiyathuray, Ajay K Singh
Although the hydrophobic size of an amphiphile plays a key role in various chemical, biological, and atmospheric processes, its effect at macroscopic aqueous interfaces (e.g. air-water, oil-water, cell membrane-water, etc.) which are ubiquitous in nature is not well understood. Here we report the hydrophobic alkyl chain length dependent structural and orientational transformations of water at alcohol (CnH2n+1OH, n = 1-12)-water interfaces using interface-selective heterodyne-detected vibrational sum frequency generation (HD-VSFG) and Raman multivariate curve resolution (Raman-MCR) spectroscopic techniques...
March 23, 2017: Journal of Physical Chemistry Letters
https://www.readbyqxmd.com/read/28333168/metallic-reductant-free-synthesis-of-%C3%AE-substituted-propionic-acid-derivatives-through-hydrocarboxylation-of-alkenes-with-a-formate-salt
#5
Jun Takaya, Ko Miyama, Chuan Zhu, Nobuharu Iwasawa
A PGeP-pincer palladium-catalyzed hydrocarboxylation of styrenes to obtain pharmaceutically important α-arylpropionic acid derivatives was achieved using a formate salt as both a reductant and a CO2 source. The reaction was also applicable to vinylsulfone and acrylates. Isotope labeling experiments demonstrated that a CO2-recycling mechanism is operative through generation and reaction of a benzylpalladium complex as a carbon nucleophile. This protocol has realized a mild and atom economical CO2-fixation reaction without the necessity of using strong metallic reductants...
March 23, 2017: Chemical Communications: Chem Comm
https://www.readbyqxmd.com/read/28333041/characterization-of-176lu-background-in-lso-based-pet-scanners
#6
Maurizio Conti, Lars Eriksson, Harold Rothfuss, Therese Sjoeholm, David Townsend, Goeran Rosenqvist, Thomas Carlier
LSO and LYSO are today the most common scintillators used in positron emission tomography. Lutetium contains traces of 176Lu, a radioactive isotope that decays - with a cascade of  photons in coincidence. Therefore, Lutetium-based scintillators are characterized by a small natural radiation background. In this paper, we investigate and characterize the 176Lu radiation background via experiments performed on LSO-based PET scanners. LSO background was measured at different energy windows and different time coincidence windows, and by using shields to alter the original spectrum...
March 23, 2017: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/28332743/nitrene-radical-approach-to-saturated-heterocycles-cobalt-porphyrin-catalysed-intramolecular-ring-closing-c-h-amination-of-aliphatic-azides
#7
Bas de Bruin, Petrus F Kuijpers, Martijn J Tiekink, Willem B Breukelaar, Daniël L J Broere, Nicolaas P van Leest, Jarl Ivar van der Vlugt, Joost N H Reek
Cobalt porphyrin catalysed intramolecular ring-closing C-H bond amination enables direct synthesis of various N-heterocycles from aliphatic azides. Pyrrolidines, oxazolidines imidazolidines, isoindolines and tetrahydroisoquinoline can be obtained in good to excellent yields in a single reaction step with an air and moisture stable catalyst. Kinetic studies of the reaction in combination with DFT calculations reveal a metallo-radical-type mechanism involving rate limiting azide activation to form the key cobalt(III)-nitrene radical intermediate...
March 23, 2017: Chemistry: a European Journal
https://www.readbyqxmd.com/read/28332244/a-fluorine-18-radiolabelling-method-enabled-by-rhenium-i-complexation-circumvents-the-requirement-of-anhydrous-conditions
#8
Mitchell Ashley Klenner, Giancarlo Pascali, Bo Zhang, Tiffany Russel Sia, Lawson Kyle Spare, Anwen M Krause-Heuer, Janice Aldrich-Wright, Ivan Greguric, Adam Guastella, Massimiliano Massi, Benjamin Hugh Fraser
Azeotropic distillation is typically required to achieve fluorine-18 radiolabelling during the production of positron emission tomography (PET) imaging agents. However, this time consuming process also limits fluorine-18 incorporation, due to radioactive decay of the isotope and its adsorption to the drying vessel. In addressing these limitations, we herein report the fluorine-18 radiolabelling of one model rhenium(I) complex, which is significantly improved under conditions that do not require azeotropic drying...
March 22, 2017: Chemistry: a European Journal
https://www.readbyqxmd.com/read/28331601/methods-to-identify-the-prey-of-invertebrate-predators-in-terrestrial-field-studies
#9
REVIEW
Klaus Birkhofer, Helena Bylund, Peter Dalin, Olga Ferlian, Vesna Gagic, Peter A Hambäck, Maartje Klapwijk, Laia Mestre, Eve Roubinet, Martin Schroeder, Johan A Stenberg, Mario Porcel, Christer Björkman, Mattias Jonsson
Predation is an interaction during which an organism kills and feeds on another organism. Past and current interest in studying predation in terrestrial habitats has yielded a number of methods to assess invertebrate predation events in terrestrial ecosystems. We provide a decision tree to select appropriate methods for individual studies. For each method, we then present a short introduction, key examples for applications, advantages and disadvantages, and an outlook to future refinements. Video and, to a lesser extent, live observations are recommended in studies that address behavioral aspects of predator-prey interactions or focus on per capita predation rates...
March 2017: Ecology and Evolution
https://www.readbyqxmd.com/read/28331578/trophic-discrimination-factor-of-nitrogen-isotopes-within-amino-acids-in-the-dobsonfly-protohermes-grandis-megaloptera-corydalidae-larvae-in-a-controlled-feeding-experiment
#10
Naoto F Ishikawa, Fumio Hayashi, Yoko Sasaki, Yoshito Chikaraishi, Naohiko Ohkouchi
The trophic discrimination factor (TDF) of nitrogen isotopes ((15)N/(14)N) within amino acids, between a stream-dwelling dobsonfly larva (Protohermes grandis: Megaloptera; Corydalidae) and its diet (chironomid larvae), was determined in controlled feeding experiments. Last-instar larvae of P. grandis were collected from the Yozawa-gawa River, central Japan, and reared in the laboratory. After fed to satiation for 1 month, one group of larvae was each fed one living chironomid larva per day for 4 weeks, while a second group was starved for 8 weeks...
March 2017: Ecology and Evolution
https://www.readbyqxmd.com/read/28331178/habitat-filtering-and-exclusion-of-weak-competitors-jointly-explain-fern-species-assemblage-along-a-light-and-water-gradient
#11
Hui Zhang, Shidan Zhu, Robert John, Ronghua Li, Hui Liu, Qing Ye
Fern species are an important component of the diversity of forest plant communities, but very little is known about how fern communities assemble in different environments. In this study, we use multiple trait-based tests to examine the relationships between several key eco-physiological traits which are direct indicators of shade and drought tolerance, and the abundance of fern species in pine forest (PF), pine and mixed broad leaf forest (PMBF) and matured broad leaf forest (MBF) in southern China. These forests are characterized by decreasing light but increasing water availability during succession, and the fern communities correspondingly differ in species composition...
March 22, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28331001/quantitative-tyrosine-phosphoproteomics-of-egfr-tyrosine-kinase-inhibitor-treated-lung-adenocarcinoma-cells-reveals-potential-novel-biomarkers-of-therapeutic-response
#12
Xu Zhang, Tapan Maity, Manoj K Kashyap, Mukesh Bansal, Abhilash Venugopalan, Sahib Singh, Shivangi Awasthi, Arivusudar Marimuthu, Harrys Kishore Charles Jacob, Natalya Belkina, Stephanie Pitts, Constance M Cultraro, Shaojian Gao, Fatos Kirkali, Romi Biswas, Raghothama Chaerkady, Andrea Califano, Akhilesh Pandey, Udayan Guha
Mutations in the Epidermal growth factor receptor (EGFR) kinase domain, such as the L858R missense mutation and deletions spanning the conserved sequence 747LREA750, are sensitive to tyrosine kinase inhibitors (TKIs). The gatekeeper site residue mutation, T790M accounts for around 60% of acquired resistance to EGFR TKIs. The first generation EGFR TKIs, erlotinib and gefitinib, and the second generation inhibitor, afatinib are FDA approved for initial treatment of EGFR mutated lung adenocarcinoma. The predominant biomarker of EGFR TKI responsiveness is the presence of EGFR TKI-sensitizing mutations...
March 22, 2017: Molecular & Cellular Proteomics: MCP
https://www.readbyqxmd.com/read/28330994/combining-dnp-nmr-with-segmental-and-specific-labeling-to-study-a-yeast-prion-protein-strain-that-is-not-parallel-in-register
#13
Kendra K Frederick, Vladimir K Michaelis, Marc A Caporini, Loren B Andreas, Galia T Debelouchina, Robert G Griffin, Susan Lindquist
The yeast prion protein Sup35NM is a self-propagating amyloid. Despite intense study, there is no consensus on the organization of monomers within Sup35NM fibrils. Some studies point to a β-helical arrangement, whereas others suggest a parallel in-register organization. Intermolecular contacts are often determined by experiments that probe long-range heteronuclear contacts for fibrils templated from a 1:1 mixture of (13)C- and (15)N-labeled monomers. However, for Sup35NM, like many large proteins, chemical shift degeneracy limits the usefulness of this approach...
March 22, 2017: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/28330337/co-generating-synthetic-parts-toward-a-self-replicating-system
#14
Jun Li, Wilhelm Haas, Kirsten Jackson, Erkin Kuru, Michael C Jewett, Z Hugh Fan, Steven P Gygi, George M Church
To build replicating systems with new functions, the engineering of existing biological machineries requires a sensible strategy. Protein synthesis Using Recombinant Elements (PURE) system consists of the desired components for transcription, translation, aminoacylation and energy regeneration. PURE, might be the basis for a radically alterable, lifelike system after optimization. Here, we regenerated 54 E. coli ribosomal (r-) proteins individually from DNA templates in the PURE system. We show that using stable isotope labeling with amino acids, mass spectrometry based quantitative proteomics could detect 26 of the 33 50S and 20 of the 21 30S subunit r-proteins when co-expressed in batch format PURE system...
March 23, 2017: ACS Synthetic Biology
https://www.readbyqxmd.com/read/28329723/analysis-of-synthetic-phenethylamine-street-drugs-using-direct-sample-analysis-coupled-to-accurate-mass-time-of-flight-mass-spectrometry
#15
Maura K McGonigal, Joshua A Wilhide, Philip B Smith, Noelle M Elliott, Frank L Dorman
Serious health complications and fatal overdoses have brought phenethylamine, otherwise known as 2C, drug abuse to the public's attention. These compounds are 2C-X series analogs of mescaline. The name "2C" results from the two carbons in the ethyl chain. The substituents on these emerging drugs are constantly changed in order to avoid listing as controlled substances. These synthetic drugs are marketed as having affects similar to LSD and MDMA and are typically consumed sublingually via blotter paper. Twenty-six commercially available standards were analyzed using a direct sample analysis technique coupled to accurate mass time of flight mass spectrometry...
March 8, 2017: Forensic Science International
https://www.readbyqxmd.com/read/28328951/practising-pastoralism-in-an-agricultural-environment-an-isotopic-analysis-of-the-impact-of-the-hunnic-incursions-on-pannonian-populations
#16
Susanne E Hakenbeck, Jane Evans, Hazel Chapman, Erzsébet Fóthi
We conducted a multi-isotope study of five fifth-century AD cemeteries in modern-day Hungary to determine relationships between nomadic-pastoralist incomers-the historically documented Huns and other nomadic groups-and the sedentary agricultural population of the late Roman province of Pannonia. Contemporary historical sources describe this relationship as adversarial and destructive for the late Roman population, but archaeological evidence indicates high levels of hybridity between different groups. We undertook carbon, nitrogen, strontium and oxygen isotope analyses of bone collagen, dentine and tooth enamel at Keszthely-Fenékpuszta, Hács-Béndekpuszta, Győr-Széchenyi Square, Mözs and Szolnok-Szanda to examine these relationships through past subsistence practices...
2017: PloS One
https://www.readbyqxmd.com/read/28328764/simultaneous-determination-of-protein-unbound-cyclosporine-a-and-mycophenolic-acid-in-kidney-transplant-patients-using-liquid-chromatography-tandem-mass-spectrometry
#17
Heike Bittersohl, Juliane Herbinger, Ming Wen, Lutz Renders, Werner Steimer, Peter B Luppa
BACKGROUND: Therapeutic drug monitoring (TDM) of immunosuppressants is essential to optimize patient care after organ transplantation. In blood, most immunosuppressive drugs are bound to plasma proteins or located inside blood cells. However, it is generally assumed that only protein-unbound (free) drug concentrations are pharmacologically active and could therefore better reflect the clinical outcome. Study data are still limited due to lacking rapid analytical methods. Therefore, a simple multiplex method for direct measurement of free cyclosporine A (CsA) and mycophenolic acid (MPA) has been developed...
March 21, 2017: Therapeutic Drug Monitoring
https://www.readbyqxmd.com/read/28328524/paramagnetic-micro-particles-as-a-tool-for-rapid-quantification-of-apixaban-dabigatran-edoxaban-and-rivaroxaban-in-human-plasma-by-uhplc-ms-ms
#18
Martin H J Wiesen, Cornelia Blaich, Thomas Streichert, Guido Michels, Carsten Müller
BACKGROUND: Assessment of the anticoagulant activity of direct oral anticoagulants (DOACs) is justified in special clinical situations. Here, we evaluated two independent extraction methods and developed a multi-analyte ultra-high performance liquid chromatography tandem mass (UHPLC-MS/MS) method for the quantification of apixaban, dabigatran, edoxaban and rivaroxaban in human plasma. METHODS: Routine extraction based on protein precipitation with acetonitrile and subsequent centrifugation was compared to sample clean-up using commercial paramagnetic micro-particles and subsequent magnetic depletion...
March 22, 2017: Clinical Chemistry and Laboratory Medicine: CCLM
https://www.readbyqxmd.com/read/28328156/one-pot-multicomponent-synthesis-of-%C3%AE-amino-amides
#19
Bo Huang, Linwei Zeng, Yangyong Shen, Sunliang Cui
Multicomponent reactions are excellent tools for rapid generation of small molecules with broad chemical diversity and molecular complexity. Herein, a novel one-pot multicomponent synthesis of β-amino amides from aldehydes, anilines, carboxylic acids and ynamides has been successfully developed. This process is practical and efficient to unravel synthetic utility and scalability. Moreover, an isotope labeling reaction was conducted to elucidate a plausible reaction mechanism.
March 22, 2017: Angewandte Chemie
https://www.readbyqxmd.com/read/28328040/purification-of-baso4-precipitate-contaminated-with-organic-matter-for-oxygen-isotope-measurements-%C3%AE-18-o-and-%C3%AE-17-o
#20
Luhua Xie, Baruch Spiro, Gangjian Wei
RATIONALE: Sulfate precipitates are often contaminated with nitrates and organic materials (OM), which reduce the precision and accuracy of measurements of δ(18) O and Δ(17) O values in the sulfate. Although nitrates can be effectively removed using diethylenetriaminepentaacetic acid solution, removing OM from the precipitates is often difficult. One effective approach is to heat powdered precipitates to high temperatures. In this study, the effect of this procedure on the δ(18) O and Δ(17) O values of BaSO4 precipitate was fully examined...
July 30, 2016: Rapid Communications in Mass Spectrometry: RCM
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