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isotopic tracer method

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https://www.readbyqxmd.com/read/29422221/detecting-the-leakage-source-of-a-reservoir-using-isotopes
#1
Peng Yi, Jing Yang, Yongdong Wang, Vincent de Paul Mugwanezal, Li Chen, Ala Aldahan
A good monitoring method is vital for understanding the sources of a water reservoir leakage and planning for effective restoring. Here we present a combination of several tracers (222Rn, oxygen and hydrogen isotopes, anions and temperature) for identification of water leakage sources in the Pushihe pumped storage power station which is in the Liaoning province, China. The results show an average 222Rn activity of 6843 Bq/m3 in the leakage water, 3034 Bq/m3 in the reservoir water, and 41,759 Bq/m3 in the groundwater...
February 5, 2018: Journal of Environmental Radioactivity
https://www.readbyqxmd.com/read/29385441/anaerobic-microbial-dehalogenation-and-its-key-players-in-the-contaminated-bitterfeld-wolfen-megasite
#2
Ivonne Nijenhuis, Reiner Stollberg, Ute Lechner
The megasite Bitterfeld-Wolfen is highly contaminated as result of accidents and because of dumping of wastes from local chemical industries in the last century. A variety of contaminants including chlorinated ethenes and benzenes, hexachlorohexanes and chlorinated dioxins can still be found in the groundwater and (river) sediments. Investigations of the in situ microbial transformation of organohalides have been performed only over the last two decades at this megasite. In this review, we summarize the research on the activity of anaerobic dehalogenating bacteria at the field site in Bitterfeld-Wolfen, focusing on chlorinated ethenes, monochlorobenzene and chlorinated dioxins...
January 29, 2018: FEMS Microbiology Ecology
https://www.readbyqxmd.com/read/29362854/simultaneous-quantification-of-endogenous-and-exogenous-plasma-glucose-by-isotope-dilution-lc-ms-ms-with-indirect-mrm-of-the-derivative-tag
#3
Lingling Yu, Chao Wen, Xing Li, Shiqi Fang, Lichuan Yang, Tony Wang, Kaifeng Hu
Quantification of endogenous and exogenous plasma glucose can help more comprehensively evaluate the glucose metabolic status. A ratio-based approach using isotope dilution liquid chromatography tandem mass spectrometry (ID LC-MS/MS) with indirect multiple reaction monitoring (MRM) of the derivative tag was developed to simultaneously quantify endo-/exogenous plasma glucose. Using diluted D-[13C6] glucose as tracer of exogenous glucose, 12C6/13C6 glucoses were first derivatized and then data were acquired in MRM mode...
January 23, 2018: Analytical and Bioanalytical Chemistry
https://www.readbyqxmd.com/read/29355599/stable-isotope-compounds-production-detection-and-application
#4
REVIEW
Vilém Zachleder, Milada Vítová, Monika Hlavová, Šárka Moudříková, Peter Mojzeš, Hermann Heumann, Johannes R Becher, Kateřina Bišová
Stable isotopes are used in wide fields of application from natural tracers in biology, geology and archeology through studies of metabolic fluxes to their application as tracers in quantitative proteomics and structural biology. We review the use of stable isotopes of biogenic elements (H, C, N, O, S, Mg, Se) with the emphasis on hydrogen and its heavy isotope deuterium. We will discuss the limitations of enriching various compounds in stable isotopes when produced in living organisms. Finally, we overview methods for measuring stable isotopes, focusing on methods for detection in single cells in situ and their exploitation in modern biotechnologies...
January 19, 2018: Biotechnology Advances
https://www.readbyqxmd.com/read/29276427/quantitative-imaging-of-deuterated-metabolic-tracers-in-biological-tissues-with-nanoscale-secondary-ion-mass-spectrometry
#5
Christelle Guillermier, J Collin Poczatek, Walter R Taylor, Matthew L Steinhauser
In the field of secondary ion mass spectrometry at nanometer scale (NanoSIMS), configuration of parallel detectors to routinely measure isotope ratios in sub-100 nm domains brings classical stable isotope tracer studies from the whole tissue level down to the suborganelle level. Over the past decade, the marriage of stable isotope tracers with NanoSIMS has been applied to a range of fundamental biological questions that were largely inaccessible by other means. Although multiplexed measurement of different stable isotope tracers is feasible, in practice there remains a gap in the current analytical capacity to efficiently measure stable isotopes commonly utilized in tracer studies...
November 2017: International Journal of Mass Spectrometry
https://www.readbyqxmd.com/read/29260858/a-methodology-for-the-validation-of-isotopic-analyses-by-mass-spectrometry-in-stable-isotope-labelling-experiments
#6
Maud Heuillet, Floriant Bellvert, Edern Cahoreau, Fabien Letisse, Pierre Millard, Jean-Charles Portais
Stable-isotope labeling experiments (ILEs) are widely used to investigate the topology and operation of metabolic networks. The quality of isotopic data collected in ILEs is of utmost importance to guarantee the reliability of biological interpretations, but current evaluation approaches are limited due to the lack of a suitable reference material and relevant evaluation criteria. In this work, we present a complete methodology to evaluate mass spectrometry (MS) methods used for quantitative isotopic studies of metabolism...
December 20, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/29249311/determination-of-gas-recovery-efficiency-at-two-danish-landfills-by-performing-downwind-methane-measurements-and-stable-carbon-isotopic-analysis
#7
Ehsan F Aghdam, Anders M Fredenslund, Jeffrey Chanton, Peter Kjeldsen, Charlotte Scheutz
In this study, the total methane (CH4) generation rate and gas recovery efficiency at two Danish landfills were determined by field measurements. The landfills are located close to each other and are connected to the same gas collection system. The tracer gas dispersion method was used for quantification of CH4 emissions from the landfills, while the CH4 oxidation efficiency in the landfill cover layers was determined by stable carbon isotopic technique. The total CH4 generation rate was estimated by a first-order decay model (Afvalzorg) and was compared with the total CH4 generation rate determined by field measurements...
December 14, 2017: Waste Management
https://www.readbyqxmd.com/read/29233262/medicinal-chemistry-strategies-for-pet-tracer-discovery
#8
REVIEW
José Ignacio Andrés, Mark Schmidt
The detection of gamma rays, resulting from decay of positron emitting isotopes, allows exquisitely sensitive detection of probes radiolabeled with such isotopes. These probes can be designed for high affinity binding to specific molecular targets and be used as tools in the early development of drugs, particularly for neuropsychiatric disorders. Availability of novel tracers requires dedicated resources and selection assays. Many of the selection assays are similar to those used for discovery of clinical compounds, although the distribution and clearance of target specific radioligands requires different in vitro and in vivo methods and new derivatives...
November 2017: Drug Discovery Today. Technologies
https://www.readbyqxmd.com/read/29224090/men-are-from-mars-women-are-from-venus-sex-differences-in-insulin-action-and-secretion
#9
Ananda Basu, Simmi Dube, Rita Basu
Sex difference plays a substantial role in the regulation of glucose metabolism in healthy glucose-tolerant humans. The factors which may contribute to the sex-related differences in glucose metabolism include differences in lifestyle (diet and exercise), sex hormones, and body composition. Several epidemiological and observational studies have noted that impaired glucose tolerance is more common in women than men. Some of these studies have attributed this to differences in body composition, while others have attributed impaired insulin sensitivity as a cause of impaired glucose tolerance in women...
2017: Advances in Experimental Medicine and Biology
https://www.readbyqxmd.com/read/29212434/stable-isotope-pharmacokinetic-studies-provide-insight-into-effects-of-age-sex-and-weight-on-levothyroxine-metabolism
#10
Islam Younis, Mariam A Ahmed, Kenneth D Burman, Offie P Soldin, Jacqueline Jonklaas
Background We wished to determine whether levothyroxine pharmacokinetics (PKs) are affected by age, weight, and sex. Methods A pharmacokinetic study was performed after administration of a tracer dose of carbon-13- labeled LT4 (13C-LT4). The study was conducted at an academic medical center. Adults of any age being treated with levothyroxine for hypothyroidism were enrolled in the study. A single dose of 13C- LT4 was administered. Eighteen serial plasma samples were collected. One sample was obtained before the 13C- LT4 dose and the majority of the remaining samples were collected over the 120-hour period post-dosing...
December 6, 2017: Thyroid: Official Journal of the American Thyroid Association
https://www.readbyqxmd.com/read/29200272/stable-isotope-resolved-analysis-with-quantitative-dissolution-dynamic-nuclear-polarization
#11
Mathilde Hauge Lerche, Demet Yigit, Anne Birk Frahm, Jan Henrik Ardenkjær-Larsen, Ronja Maja Malinowski, Pernille Rose Jensen
Metabolite profiles and their isotopomer distributions can be studied non-invasively in complex mixtures with NMR. The advent of dissolution Dynamic Nuclear Polarization (dDNP) and isotope enrichment add sensitivity and resolution to such met-abolic studies. Metabolic pathways and networks can be mapped and quantified if protocols that control and exploit the ex situ sig-nal enhancement are created. We present a sample preparation method, including cell incubation, extraction and signal enhance-ment, to facilitate reproducible and quantitative dDNP (qdDNP) NMR-based isotope tracer analysis...
December 4, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/29159966/interrogating-marine-virus-host-interactions-and-elemental-transfer-with-boncat-and-nanosims-based-methods
#12
Alexis L Pasulka, Kimberlee Thamatrakoln, Sebastian H Kopf, Yunbin Guan, Bonnie Poulos, Annie Moradian, Michael J Sweredoski, Sonja Hess, Mathew B Sullivan, Kay D Bidle, Victoria J Orphan
While the collective impact of marine viruses has become more apparent over the last decade, a deeper understanding of virus-host dynamics and the role of viruses in nutrient cycling would benefit from direct observations at the single-virus level. We describe two new complementary approaches - stable isotope probing coupled with nanoscale secondary ion mass spectrometry (nanoSIMS) and fluorescence-based biorthogonal non-canonical amino acid tagging (BONCAT) - for studying the activity and biogeochemical influence of marine viruses...
November 21, 2017: Environmental Microbiology
https://www.readbyqxmd.com/read/29158483/noninvasive-liquid-diet-delivery-of-stable-isotopes-into-mouse-models-for-deep-metabolic-network-tracing
#13
Ramon C Sun, Teresa W-M Fan, Pan Deng, Richard M Higashi, Andrew N Lane, Anh-Thu Le, Timothy L Scott, Qiushi Sun, Marc O Warmoes, Ye Yang
Delivering isotopic tracers for metabolic studies in rodents without overt stress is challenging. Current methods achieve low label enrichment in proteins and lipids. Here, we report noninvasive introduction of (13)C6-glucose via a stress-free, ad libitum liquid diet. Using NMR and ion chromatography-mass spectrometry, we quantify extensive (13)C enrichment in products of glycolysis, the Krebs cycle, the pentose phosphate pathway, nucleobases, UDP-sugars, glycogen, lipids, and proteins in mouse tissues during 12 to 48 h of (13)C6-glucose feeding...
November 21, 2017: Nature Communications
https://www.readbyqxmd.com/read/29149751/massive-arrival-of-desalinated-seawater-in-a-regional-urban-water-cycle-a-multi-isotope-study-b-s-o-h
#14
W Kloppmann, Ido Negev, Joseph Guttman, Orly Goren, Ittai Gavrieli, Catherine Guerrot, Christine Flehoc, Marie Pettenati, Avihu Burg
"Man-made" or unconventional freshwater, like desalinated seawater or reclaimed effluents, is increasingly introduced into regional water cycles in arid or semi-arid countries. We show that the breakthrough of reverse osmosis-derived freshwater in the largely engineered water cycle of the greater Tel Aviv region (Dan Region) has profoundly changed previous isotope fingerprints. This new component can be traced throughout the system, from the drinking water supply, through sewage, treated effluents, and artificially recharged groundwater at the largest Soil-Aquifer Treatment system in the Middle East (Shafdan) collecting all the Dan region sewage...
November 14, 2017: Science of the Total Environment
https://www.readbyqxmd.com/read/29131928/n-and-o-isotope-%C3%AE-15-n-%C3%AE-%C3%AE-15-n-%C3%AE-%C3%AE-18-o-%C3%AE-17-o-analyses-of-dissolved-no3-and-no2-by-the-cd-azide-reduction-method-and-n2-o-laser-spectrometry
#15
Leonard I Wassenaar, Cedric Douence, Mark Altabet, Pradeep Aggarwal
RATIONALE: The nitrogen and oxygen (δ(15) N, δ(18) O, δ(17) O) isotopic compositions of NO3(-) and NO2(-) are important tracers of nutrient dynamics in soil, rain, groundwater and the oceans. The Cd-azide method was used to convert NO3 or NO2 to N2 O for N and triple-O isotopic analyses by N2 O-laser spectrometry. A protocol for laser-based headspace isotope analyses was compared with isotope-ratio mass spectrometry. Lasers provide the ability to directly measure (17) O anomalies which can help discern atmospheric N sources...
November 13, 2017: Rapid Communications in Mass Spectrometry: RCM
https://www.readbyqxmd.com/read/29054406/a-novel-puromycin-decorporation-method-to-quantify-skeletal-muscle-protein-breakdown-a-proof-of-concept-study
#16
Hannah Crossland, Kenneth Smith, Philip J Atherton, Daniel J Wilkinson
The precise roles that the major proteolytic pathways play in the regulation of skeletal muscle mass remain incompletely understood, in part due to technical limitations associated with current techniques used to quantify muscle protein breakdown (MPB). We aimed to develop a method to assess MPB in cells, based on loss of puromycin labelling of translated polypeptide chains. Following an initial 24 h incubation period with puromycin (1 μM), loss of puromycin labelling from murine C2C12 myotubes was assessed over 48 h, both in the presence or absence of protein synthesis inhibitor cycloheximide (CHX)...
October 17, 2017: Biochemical and Biophysical Research Communications
https://www.readbyqxmd.com/read/29039106/improved-ultrafiltration-method-to-measure-drug-release-from-nanomedicines-utilizing-a-stable-isotope-tracer
#17
Sarah L Skoczen, Stephan T Stern
An important step in the early development of a nanomedicine formulation is the evaluation of stability and drug release in biological matrices. Additionally, the measurement of encapsulated and unencapsulated nanomedicine drug fractions is important for the determination of bioequivalence (pharmacokinetic equivalence) of generic nanomedicines. Unfortunately, current methods to measure drug release in plasma are limited, and all have fundamental disadvantages including non-equilibrium conditions and process-induced artifacts...
2018: Methods in Molecular Biology
https://www.readbyqxmd.com/read/29035267/coastal-ocean-and-shelf-sea-biogeochemical-cycling-of-trace-elements-and-isotopes-lessons-learned-from-geotraces
#18
REVIEW
Matthew A Charette, Phoebe J Lam, Maeve C Lohan, Eun Young Kwon, Vanessa Hatje, Catherine Jeandel, Alan M Shiller, Gregory A Cutter, Alex Thomas, Philip W Boyd, William B Homoky, Angela Milne, Helmuth Thomas, Per S Andersson, Don Porcelli, Takahiro Tanaka, Walter Geibert, Frank Dehairs, Jordi Garcia-Orellana
Continental shelves and shelf seas play a central role in the global carbon cycle. However, their importance with respect to trace element and isotope (TEI) inputs to ocean basins is less well understood. Here, we present major findings on shelf TEI biogeochemistry from the GEOTRACES programme as well as a proof of concept for a new method to estimate shelf TEI fluxes. The case studies focus on advances in our understanding of TEI cycling in the Arctic, transformations within a major river estuary (Amazon), shelf sediment micronutrient fluxes and basin-scale estimates of submarine groundwater discharge...
November 28, 2016: Philosophical Transactions. Series A, Mathematical, Physical, and Engineering Sciences
https://www.readbyqxmd.com/read/29027346/application-of-stable-isotope-labelling-techniques-for-the-detection-of-active-diazotrophs
#19
Roey Angel, Christopher Panhölzl, Raphael Gabriel, Craig Herbold, Wolfgang Wanek, Andreas Richter, Stephanie A Eichorst, Dagmar Woebken
Investigating active participants in the fixation of dinitrogen gas is vital as N is often a limiting factor for primary production. Biological nitrogen fixation (BNF) is performed by a diverse guild of bacteria and archaea (diazotrophs), which can be free-living or symbionts. Free-living diazotrophs are widely distributed in the environment, yet our knowledge about their identity and ecophysiology is still limited. A major challenge in investigating this guild is inferring activity from genetic data as this process is highly regulated...
October 13, 2017: Environmental Microbiology
https://www.readbyqxmd.com/read/28983702/measurement-of-the-15-n-14-n-ratio-of-phenylalanine-in-fermentation-matrix-by-isotope-ratio-mass-spectrometry
#20
Shiwei Zhang, Qiding Zhong, Daobing Wang, Zhanbin Huang, Guohui Li
OBJECTIVES: To determine the origin of (15)N-labeled phenylalanine in microbial metabolic flux analysis using (15)N as a tracer, a method for measuring phenylalanine δ(15)N using HPLC coupled with elemental analysis-isotope ratio mass spectrometry (EA-IRMS) was developed. RESULTS: The original source of the (15)N-labeled phenylalanine was determined using this new method that consists of three steps: optimization of the HPLC conditions, evaluation of the isotope fractionation effects, and evaluation of the effect of pre-processing on the phenylalanine nitrogen stable isotope...
October 5, 2017: Biotechnology Letters
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