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https://www.readbyqxmd.com/read/29783197/quantification-of-21-antihypertensive-drugs-in-serum-using-uhplc-ms-ms
#1
Per Ole M Gundersen, Arne Helland, Olav Spigset, Solfrid Hegstad
BACKGROUND: Poor drug adherence in hypertensive patients can lead to treatment failure and increased cardiovascular morbidity, as well as increased costs to society. An analytical method based on ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MSMS) was developed and validated for use in routine therapeutic drug monitoring (TDM). The method includes 21 antihypertensive drugs or active metabolites from the groups beta blockers (n=5), calcium antagonists (n=5), angiotensin II receptor antagonists (n=4), angiotensin converting enzyme (ACE) inhibitors (n=3) and diuretics (n = 3), in addition to one α1-selective alpha blocker...
April 28, 2018: Journal of Chromatography. B, Analytical Technologies in the Biomedical and Life Sciences
https://www.readbyqxmd.com/read/29783130/an-explanation-of-the-methanogenic-pathway-for-methane-production-in-anaerobic-digestion-of-nitrogen-rich-materials-under-mesophilic-and-thermophilic-conditions
#2
Dong-Min Yin, Maria Westerholm, Wei Qiao, Shao-Jie Bi, Simon M Wandera, Run Fan, Meng-Meng Jiang, Ren-Jie Dong
The impact of temperature on the anaerobic digestion of chicken manure was investigated by studying the process performance and pathway for continuously-fed digesters under mesophilic and thermophilic conditions. The mesophilic digester obtained a 15% higher methane yield compared with the thermophilic digester. Mesophilic and thermophilic digester had free ammonia of 31 and 145 mg/L, respectively. The stable carbon isotope analysis indicated that 41% and 50% of acetate was converted to methane through the syntrophic acetate oxidation and hydrogenotrophic methanogenesis (SAO-HM) pathway under mesophilic and thermophilic conditions, respectively...
May 18, 2018: Bioresource Technology
https://www.readbyqxmd.com/read/29782790/magnetite-triggering-enhanced-diet-a-scavenger-for-the-blockage-of-electron-transfer-in-anaerobic-digestion-of-high-solids-sewage-sludge
#3
Tao Wang, Dong Zhang, Lingling Dai, Bin Dong, Xiaohu Dai
At present, high-solids anaerobic digestion of sewage sludge has drawn great attention due to the superiority of its small land area footprint and low energy consumption. However, a high organic loading rate may cause acids accumulation and ammonia inhibition, thus leading to an inhibited pseudo-steady state in which electron transfer through interspecies hydrogen transfer (IHT) between acetogens and methanogens is blocked. In this study, adding 50 mg/g TS (total solid) magnetite clearly reduced the accumulation of short-chain fatty acids and accelerated methane production by 26...
May 21, 2018: Environmental Science & Technology
https://www.readbyqxmd.com/read/29782704/profiling-of-new-psychoactive-substances-nps-by-using-stable-isotope-ratio-mass-spectrometry-irms-study-on-the-synthetic-cannabinoid-5f-pb-22
#4
S Münster-Müller, N Scheid, T Holdermann, S Schneiders, M Pütz
In this paper results of a pilot study on the profiling of the synthetic cannabinoid receptor agonist 5F-PB-22 (5F-QUPIC, pentylfluoro-1H-indole-3-carboxylic acid-8-quinolinyl ester) via isotope ratio mass spectrometry are presented. It is focused on δ13 C, δ15 N and δ2 H isotope ratios, which are determined using elemental analyser (EA) and high temperature elemental analyser (TC/EA) coupled to an isotope ratio mass spectrometer (IRMS). By means of a sample of pure material of 5F-PB-22 it is shown that the extraction of 5F-PB-22 from herbal material, a rapid clean-up procedure, or preparative column chromatography had no influences on the isotope ratios...
May 21, 2018: Drug Testing and Analysis
https://www.readbyqxmd.com/read/29782547/isotope-niche-dimension-and-trophic-overlap-between-bigheaded-carps-and-native-filter-feeding-fish-in-the-lower-missouri-river-usa
#5
Jianzhu Wang, Duane Chapman, Jun Xu, Yang Wang, Binhe Gu
Stable carbon and nitrogen isotope values (δ13C and δ15N) were used to evaluate trophic niche overlap between two filter-feeding fishes (known together as bigheaded carp) native to China, silver carp (Hypophthalmichthys molitrix) and bighead carp (Hypophthalmichthys nobilis), and three native filter-feeding fish including bigmouth buffalo (Ictiobus cyprinellus), gizzard shad (Dorosoma cepedianum) and paddlefish (Polyodon spathula) in the lower Missouri River, USA, using the Bayesian Stable Isotope in R statistics...
2018: PloS One
https://www.readbyqxmd.com/read/29782002/quantitative-and-qualitative-method-for-sphingomyelin-by-lc-ms-using-two-stable-isotopically-labeled-sphingomyelin-species
#6
Kotaro Hama, Yuko Fujiwara, Kazuaki Yokoyama
We present a method of analyzing sphingomyelin (SM) qualitatively and quantitatively by liquid chromatography-electrospray Ionization-tandem mass spectrometry (LC-ESI-MS/MS). SM is a common sphingolipid composed of a phosphorylcholine and a ceramide as the hydrophilic and hydrophobic component, respectively. A number of SM species are present in mammalian cells due to a variety in the sphingoid long chain base (LCB) and an N-acyl moiety in the ceramide. In this report, we show a method of estimating the number of carbon and double bonds in a LCB and an N-acyl moiety based on their corresponding product ions in MS/MS/MS (MS3 ) experiments...
May 7, 2018: Journal of Visualized Experiments: JoVE
https://www.readbyqxmd.com/read/29781400/two-step-extraction-method-for-lead-isotope-fractionation-to-reveal-anthropogenic-lead-pollution
#7
Kenshi Katahira, Hiroshi Moriwaki, Kazuo Kamura, Hideo Yamazaki
This study developed the 2-step extraction method which eluted the Pb adsorbing on the surface of sediments in the first solution by aqua regia and extracted the Pb absorbed inside particles into the second solution by mixed acid of nitric acid, hydrofluoric acid and hydrogen peroxide solution. We applied the method to sediments in the enclosed water area and found out that the isotope ratios of Pb in the second solution represented those of natural origin. This advantage of the method makes it possible to distinguish the Pb between natural origin and anthropogenic source on the basis of the isotope ratios...
May 21, 2018: Environmental Technology
https://www.readbyqxmd.com/read/29781254/determination-of-carbon-isotope-ratios-for-honey-samples-by-means-of-a-liquid-chromatography-isotope-ratio-mass-spectrometry-system-coupled-with-a-post-column-pump
#8
Hiroto Kawashima, Momoka Suto, Nana Suto
RATIONALE: Liquid chromatography/isotope ratio mass spectrometry (LC/IRMS) has been used to authenticate and trace products such as honey, wine, and lemon juice, and compounds such as caffeine and pesticides. However, LC/IRMS has several disadvantages, including the high cost of the CO2 membrane and blocking by solidified sodium persulfate. Here, we developed an improved system for determining carbon isotope ratios by LC/IRMS. METHODS: The main improvement was the use of a post-column pump...
May 20, 2018: Rapid Communications in Mass Spectrometry: RCM
https://www.readbyqxmd.com/read/29781219/disentangling-the-effects-of-acidic-air-pollution-atmospheric-co-2-and-climate-change-on-recent-growth-of-red-spruce-trees-in-the-central-appalachian-mountains
#9
Justin M Mathias, Richard B Thomas
In the 45 years after legislation of the Clean Air Act, there has been tremendous progress in reducing acidic air pollutants in the eastern United States, yet limited evidence exists that cleaner air has improved forest health. Here, we investigate the influence of recent environmental changes on the growth and physiology of red spruce (Picea rubens Sarg.) trees, a key indicator species of forest health, spanning three locations along a 100 km transect in the Central Appalachian Mountains. We incorporated a multiproxy approach using 75-year tree ring chronologies of basal tree growth, carbon isotope discrimination (∆13 C, a proxy for leaf gas exchange), and δ15 N (a proxy for ecosystem N status) to examine tree and ecosystem level responses to environmental change...
May 20, 2018: Global Change Biology
https://www.readbyqxmd.com/read/29781092/assimilation-of-nitrogen-and-carbon-isotopes-from-fish-diets-to-otoliths-as-measured-by-nanoscale-secondary-ion-mass-spectrometry
#10
Jen-Chieh Shiao, Kotaro Shirai, Kentaro Tanaka, Naoto Takahata, Yuji Sano, Sung-Yun Hsiao, Der-Chuen Lee, Yung-Che Tseng
RATIONALE: Nitrogen and carbon stable isotope ratios (δ15 N and δ13 C values) of carbonate-bound organic materials in otoliths can provide information to address the biological and ecological functions of fish. Correct interpretation of otolith δ15 N and δ13 C profiles requires knowledge of the metabolic routes of nitrogen and carbon isotopes. However, the isotopic assimilation of δ15 N and δ13 C compositions from diets to otoliths has rarely been investigated. METHODS: This study traced the daily nitrogen and carbon isotopic assimilation between diets and otoliths using nanoscale secondary ion mass spectrometry (NanoSIMS)...
May 21, 2018: Rapid Communications in Mass Spectrometry: RCM
https://www.readbyqxmd.com/read/29780468/room-temperature-olefination-of-methane-with-titanium-carbon-multiple-bonds
#11
Takashi Kurogi, Joonghee Won, Bohyun Park, Oleksandra S Trofymchuk, Patrick J Carroll, Mu-Hyun Baik, Daniel J Mindiola
C-H activation of methane followed by dehydrocoupling at room temperature led ultimately to the formation of the olefin H2 C 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 1111111111111111111111111111111111 1111111111111111111111111111111111 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 1111111111111111111111111111111111 1111111111111111111111111111111111 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 CH t Bu via the addition of redox-active ligands (L) such as thioxanthone or 2,2'-bipyridine (bipy) to (PNP)Ti 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 1111111111111111111111111111111111 1111111111111111111111111111111111 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 1111111111111111111111111111111111 1111111111111111111111111111111111 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 CH t Bu(CH3 ) ( 1 )...
April 7, 2018: Chemical Science
https://www.readbyqxmd.com/read/29780292/pathway-specific-metabolome-analysis-with-18-o-2-labeled-medicago-truncatula-via-a-mass-spectrometry-based-approach
#12
Kota Kera, Dennis D Fine, Daniel J Wherritt, Yoshiki Nagashima, Norimoto Shimada, Takeshi Ara, Yoshiyuki Ogata, Lloyd W Sumner, Hideyuki Suzuki
Introduction: Oxygen from carbon dioxide, water or molecular oxygen, depending on the responsible enzyme, can lead to a large variety of metabolites through chemical modification. Objectives: Pathway-specific labeling using isotopic molecular oxygen (18 O2 ) makes it possible to determine the origin of oxygen atoms in metabolites and the presence of biosynthetic enzymes (e.g., oxygenases). In this study, we established the basis of 18 O2 -metabolome analysis. Methods: 18 O2 labeled whole Medicago truncatula seedlings were prepared using 18 O2 -air and an economical sealed-glass bottle system...
2018: Metabolomics: Official Journal of the Metabolomic Society
https://www.readbyqxmd.com/read/29780176/sex-size-and-isotopes-cryptic-trophic-ecology-of-an-apex-predator-the-white-shark-carcharodon-carcharias
#13
G C A French, S Rizzuto, M Stürup, R Inger, S Barker, J H van Wyk, A V Towner, W O H Hughes
Demographic differences in resource use are key components of population and species ecology across the animal kingdom. White sharks ( Carcharodon carcharias ) are migratory, apex predators, which have undergone significant population declines across their range. Understanding their ecology is key to ensuring that management strategies are effective. Here, we carry out the first stable isotope analyses of free-swimming white sharks in South Africa. Biopsies were collected in Gansbaai (34.5805°S, 19.3518°E) between February and July 2015...
2018: Marine Biology
https://www.readbyqxmd.com/read/29779945/moderate-uv-exposure-enhances-learning-and-memory-by-promoting-a-novel-glutamate-biosynthetic-pathway-in-the-brain
#14
Hongying Zhu, Ning Wang, Lei Yao, Qi Chen, Ran Zhang, Junchao Qian, Yiwen Hou, Weiwei Guo, Sijia Fan, Siling Liu, Qiaoyun Zhao, Feng Du, Xin Zuo, Yujun Guo, Yan Xu, Jiali Li, Tian Xue, Kai Zhong, Xiaoyuan Song, Guangming Huang, Wei Xiong
Sunlight exposure is known to affect mood, learning, and cognition. However, the molecular and cellular mechanisms remain elusive. Here, we show that moderate UV exposure elevated blood urocanic acid (UCA), which then crossed the blood-brain barrier. Single-cell mass spectrometry and isotopic labeling revealed a novel intra-neuronal metabolic pathway converting UCA to glutamate (GLU) after UV exposure. This UV-triggered GLU synthesis promoted its packaging into synaptic vesicles and its release at glutamatergic terminals in the motor cortex and hippocampus...
May 7, 2018: Cell
https://www.readbyqxmd.com/read/29779806/iron-absorption-from-beans-with-different-contents-of-iron-evaluated-by-stable-isotopes
#15
Márcia Varella Morandi Junqueira-Franco, José Eduardo Dutra de Oliveira, Marilia Regini Nutti, Helton Santos Pereira, José Luiz Vianna de Carvalho, Steven A Abrams, Camila Fernanda Cunha Brandão, Júlio Sérgio Marchini
BACKGROUND: The introduction of biofortified foods such as beans with higher iron content may be a useful tool in preventing iron deficiency. The biofortification aims to reach the root of the problem of malnutrition, targets the neediest population, uses embedded distribution mechanisms, is scientifically feasible and effective in terms of cost, and complements other ongoing interventions to control micronutrient deficiency. However, to ensure effectiveness, measurement of the absorption of minerals is essential...
June 2018: Clinical Nutrition ESPEN
https://www.readbyqxmd.com/read/29779659/preparation-assay-and-application-of-chlorinase-sall-for-the-chemoenzymatic-synthesis-of-s-adenosyl-l-methionine-and-analogs
#16
Tony D Davis, Sylvia Kunakom, Michael D Burkart, Alessandra S Eustaquio
S-adenosyl-l-methionine (SAM) is universal in biology, serving as the second most common cofactor in a variety of enzymatic reactions. One of the main roles of SAM is the methylation of nucleic acids, proteins, and metabolites. Methylation often imparts regulatory control to DNA and proteins, and leads to an increase in the activity of specialized metabolites such as those developed as pharmaceuticals. There has been increased interest in using SAM analogs in methyltransferase-catalyzed modification of biomolecules...
2018: Methods in Enzymology
https://www.readbyqxmd.com/read/29779374/molecularly-imprinted-polymers-for-compound-specific-isotope-analysis-of-polar-organic-micropollutants-in-aquatic-environments
#17
Rani Bakkour, Jakov Bolotin, Börje Sellergren, Thomas B Hofstetter
Compound-specific isotope analysis (CSIA) of polar organic micropollutants in environmental waters requires a processing of large sample volumes to obtain the required analyte masses for analysis by gas chromatography / isotope-ratio mass spectrometry (GC/IRMS). However, the accumulation of organic matter of unknown isotopic composition in standard enrichment procedures currently compromises the accurate determination of isotope ratios. We explored the use of molecularly-imprinted polymers (MIPs) for selective analyte enrichment for 13C/12C and 15N/14N ratio measurements by GC/IRMS using 1H-benzotriazole, a typical corrosion inhibitor in dishwashing detergents, as example of a widely detected polar organic micropollutant...
May 20, 2018: Analytical Chemistry
https://www.readbyqxmd.com/read/29779111/magnetosensitivity-of-e-coli-bacteria-in-the-presence-of-zinc-isotopes
#18
U G Letuta, D M Shailina
The combined effect of the zinc magnetic isotope 67 Zn and weak magnetic field 25-35 mT causes a 2-4-fold increase in the colony-forming ability of bacteria E. coli in comparison with the nonmagnetic isotopes 64, 66 Zn. The effects of magnetic field in the range of 2.2-8 mT were detected for all bacteria regardless of the zinc-isotope enrichment of the media. This indicates the sensitivity of intracellular processes to weak magnetic fields. An increase in the ATP concentration in E. coli cells was only detected for the bacteria grown on the medium with the magnetic zinc isotope in the range of 2...
March 2018: Doklady. Biochemistry and Biophysics
https://www.readbyqxmd.com/read/29779067/cost-effective-large-scale-expression-of-proteins-for-nmr-studies
#19
Julia Klopp, Aurélie Winterhalter, Rémy Gébleux, Daniela Scherer-Becker, Christian Ostermeier, Alvar D Gossert
We present protocols for high-level expression of isotope-labelled proteins in E. coli in cost-effective ways. This includes production of large amounts of unlabeled proteins and 13 C-methyl methionine labeling in rich media, where yields of up to a gram of soluble protein per liter of culture are reached. Procedures for uniform isotope labeling of 2 H, 13 C and 15 N using auto-induction or isopropyl-β-D-1-thiogalactopyranoside-induction are described, with primary focus on minimal isotope consumption and high reproducibility of protein expression...
May 19, 2018: Journal of Biomolecular NMR
https://www.readbyqxmd.com/read/29778874/simultaneous-determination-of-dihydrotestosterone-and-its-metabolites-in-mouse-sera-by-lc-ms-ms-with-chemical-derivatization
#20
Shashank Gorityala, Shuming Yang, Monica M Montano, Yan Xu
Androgens play a vital role in prostate cancer development, and their elimination and blockade are essential in the disease management. DHT is the key ligand for androgen receptor (AR) in the prostate. It is locally synthesized from testosterone. In the prostate, DHT is predominantly metabolized to α-diol and β-diol. Recent studies indicate that impaired DHT catabolism is associated with prostate cancer, signifying the necessity of a sensitive quantitative method for the determination of DHT and its metabolites...
May 16, 2018: Journal of Chromatography. B, Analytical Technologies in the Biomedical and Life Sciences
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