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https://www.readbyqxmd.com/read/28225829/inhibition-of-arabidopsis-chloroplast-%C3%AE-amylase-bam3-by-maltotriose-suggests-a-mechanism-for-the-control-of-transitory-leaf-starch-mobilisation
#1
Jing Li, Wenxu Zhou, Perigio Francisco, Russell Wong, Dongke Zhang, Steven M Smith
Starch breakdown in leaves at night is tightly matched to the duration of the dark period, but the mechanism by which this regulation is achieved is unknown. In Arabidopsis chloroplasts, β-amylase BAM3 hydrolyses transitory starch, producing maltose and residual maltotriose. The aim of the current research was to investigate the regulatory and kinetic properties of BAM3. The BAM3 protein was expressed in Escherichia coli and first assayed using a model substrate. Enzyme activity was stimulated by treatment with dithiothreitol and was increased 40% by 2-10 μM Ca2+ but did not require Mg2+...
2017: PloS One
https://www.readbyqxmd.com/read/28225553/correlations-among-mercury-concentration-and-stable-isotope-ratios-of-carbon-and-nitrogen-of-amino-acids-in-scalp-hair-from-whale-meat-eaters-and-heavy-fish-eaters
#2
Tetsuya Endo, Hideki Ogasawara, Moriaki Hayasaka, Yohei Hotta, Osamu Kimura, Klaus J Petzke
RATIONALE: As Hg accumulation in marine animals generally increases with increased trophic level (δ(15) N values) through the food web, predators accumulate higher levels of Hg. The main source of human Hg intake is the consumption of fish and other marine animals, and Hg concentration in scalp hair is the preferred marker for evaluating consumption of marine animals. Difference of δ(15) N values between trophic and source amino acids of human consumers could enable us to estimate the trophic level of consumer without knowing the bulk δ(15) N value of their prey...
February 22, 2017: Rapid Communications in Mass Spectrometry: RCM
https://www.readbyqxmd.com/read/28225098/urinary-metabolic-signatures-and-early-triage-of-acute-radiation-exposure-in-rat-model
#3
Mingxiao Zhao, Kim Kt Lau, Xian Zhou, Jianfang Wu, Jun Yang, Chang Wang
After a large-scale radiological accident, early-response biomarkers to assess radiation exposure over a broad dose range are not only the basis of rapid radiation triage, but are also the key to the rational use of limited medical resources and to the improvement of treatment efficiency. Because of its high throughput, rapid assays and minimally invasive sample collection, metabolomics has been applied to research into radiation exposure biomarkers in recent years. Due to the complexity of radiobiological effects, most of the potential biomarkers are both dose-dependent and time-dependent...
February 22, 2017: Molecular BioSystems
https://www.readbyqxmd.com/read/28224911/determination-of-total-cyanide-in-soil-by-isotope-dilution-gc-ms-following-pentafluorobenzyl-derivatization
#4
Beatrice Campanella, Lorenzo Biancalana, Lucia D'Ulivo, Massimo Onor, Emilia Bramanti, Zoltan Mester, Enea Pagliano
The high toxicity of cyanide, along with its widespread industrial use, has fuelled interest in the development of analytical methods for its determination in complex matrices. In this study, we propose a novel approach for the measurement of total cyanide in soil samples based on single-step derivatization with pentafluorobenzyl bromide (F5Bn-Br) followed by quantitation with gas chromatography mass spectrometry in negative chemical ionization mode. The reaction between CN(-) and F5Bn-Br resulted in the identification of several derivatives such as F5Bn-CN, (F5Bn)(F5Ph)CH-CN, and (F5Bn)2(F5Ph)C-CN...
April 8, 2017: Analytica Chimica Acta
https://www.readbyqxmd.com/read/28224910/identification-of-sink-spots-in-two-thermal-desorption-gc-ms-systems-for-the-analysis-of-polycyclic-aromatic-hydrocarbons
#5
Yingjie Li, Jiping Zhu
Thermal desorption (TD) GC/MS has been used for the analysis of polycyclic aromatic hydrocarbons (PAHs) and other semi-volatile organic compounds. However, thermal desorption recovery of PAHs have not been well studied and the cause of PAH residues in a TD system has not been clearly understood. Our results showed that low volatility of PAHs can lead to their incomplete recovery in a TD system: for the PAHs with low vapour pressures, up to 10% and 3% could be lost in a two-stage (TS) TD system and a short-path (SP) TD system, respectively...
April 8, 2017: Analytica Chimica Acta
https://www.readbyqxmd.com/read/28224723/synthetic-extreme-environments-overlooked-sources-of-potential-biotechnologically-relevant-microorganisms
#6
Timothy Sibanda, Ramganesh Selvarajan, Memory Tekere
Synthetic extreme environments like carwash effluent tanks and drains are potential sources of biotechnologically important microorganisms and molecules which have, however, remained unexplored. Using culture- and molecular-based methods, a total of 17 bacterial isolates belonging to the genera Shewanella, Proteus, Paenibacillus, Enterobacter and Citrobacter, Aeromonas, Pseudomonas and Pantoea were identified. Hydrocarbon utilization and enzyme production screening assays showed that Aeromonas sp. CAC11, Paenibacillus sp...
February 22, 2017: Microbial Biotechnology
https://www.readbyqxmd.com/read/28222613/phytochemical-investigations-and-antiproliferative-secondary-metabolites-from-thymus-alternans-growing-in-slovakia
#7
Stefano Dall'Acqua, Gregorio Peron, Sara Ferrari, Valentina Gandin, Massimo Bramucci, Luana Quassinti, Pavol Mártonfi, Filippo Maggi
CONTEXT: Thymus alternans Klokov (Lamiaceae) is a neglected species of the genus Thymus (Sect. Serpyllum) endemic to Carpathian area, where it is used as a flavouring agent and for medicinal purposes. OBJECTIVE: The aim of the work was to identify antiproliferative constituents from the flowering aerial parts of this plant. MATERIALS AND METHODS: Thymus alternans extracts were analyzed by HPLC-MS(n) and subjected to extensive chromatographic separations...
December 2017: Pharmaceutical Biology
https://www.readbyqxmd.com/read/28222592/confirmation-of-1-phenylethane-1-thiol-as-the-character-impact-aroma-compound-in-curry-leaves-and-its-behavior-during-tissue-disruption-drying-and-frying
#8
Martin Steinhaus
The most odor-active compounds previously identified by application of an aroma extract dilution analysis were quantitated in freshly picked curry leaves, either by stable isotope dilution assays in combination with GC-GC-MS or by GC-FID after simultaneous extraction/fractionation. Odor activity values (OAVs) were calculated as ratios of concentrations to odor threshold values. The topmost OAVs were obtained for (3Z)-hex-3-enal (grassy; OAV 180000), (1S)-1-phenylethane-1-thiol (sulfury, burnt; OAV 150000), (1R)-1-phenylethane-1-thiol (sulfury, burnt; OAV 120000), (3R)-linalool (citrusy; OAV 58000), and myrcene (geranium leaf-like; OAV 23000)...
February 22, 2017: Journal of Agricultural and Food Chemistry
https://www.readbyqxmd.com/read/28221781/the-relationship-between-organic-loading-and-effects-on-fish-reproduction-for-pulp-mill-effluents-across-canada
#9
Pierre H Martel, Brian I O'Connor, Tibor G Kovacs, Michael R Van Den Heuvel, Joanne L Parrott, Mark E McMaster, Deborah L MacLatchy, Glen J Van Der Kraak, L Mark Hewitt
This study builds upon the work of a multiagency consortium tasked with determining cost effective solutions for the effects of pulp mill effluents on fish reproduction. A laboratory fathead minnow egg production test and chemical characterization tools were used to benchmark eighty-one effluents from twenty mills across Canada, representing the major pulping, bleaching and effluent treatment technologies. For Kraft and mechanical pulp mills, effluents containing less than 20 mg/L BOD5 were found to have the greatest probability of having no effects...
February 21, 2017: Environmental Science & Technology
https://www.readbyqxmd.com/read/28218832/a-non-invasive-strategy-based-on-real-time-in-vivo-cataluminescence-monitoring-for-clinical-breath-analysis
#10
Runkun Zhang, Wanting Huang, Gongke Li, Yufei Hu
The development of non-invasive methods for real-time in vivo analysis is of great significant, which provides powerful tools for medical research and clinical diagnosis. In the present work, we described a new strategy based on cataluminescence (CTL) for real-time in vivo clinical breath analysis. To illustrate such strategy, a homemade real-time CTL monitoring system characterized by coupling an on-line sampling device with a CTL sensor for sevoflurane (SVF) was designed, and a real-time in vivo method for the monitoring of SVF in exhaled breath was proposed...
February 20, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28217981/composition-antifungal-and-antiproliferative-activities-of-the-hydrodistilled-oils-from-leaves-and-flower-heads-of-pterocephalus-nestorianus-nab
#11
Fuad O Abdullah, Faiq H S Hussain, Barbara Mannucci, Rosamaria Lappano, Solveig Tosi, Marcello Maggiolini, Giovanni Vidari
This paper reports the first study of the chemical composition, and antifungal and antiproliferative properties of the volatile extracts obtained by hydrodistillation of the flower heads and leaves of the traditional Kurdish medicinal plant P. nestorianus Nab., collected in the wild. A total of fifty-five constituents, 43 of the flower heads' oil (PFO) and 46 of the leaves' oil (PLO), respectively, were identified by GC/MS, constituting 99.68% and 99.04% of the two oils, respectively. The oils were obtained in 0...
February 19, 2017: Chemistry & Biodiversity
https://www.readbyqxmd.com/read/28217904/development-of-microextraction-techniques-in-combination-with-gc-ms-ms-for-the-determination-of-mycotoxins-and-metabolites-in-human-urine
#12
Yelko Rodríguez-Carrasco, Juan Carlos Moltó, Jordi Mañes, Houda Berrada
Simple and highly efficient sample preparation procedures, namely, dispersive liquid-liquid microextraction and salting-out liquid-liquid extraction for the analysis of ten Fusarium mycotoxins and metabolites in human urine were compared. Various parameters affecting extraction efficiency were carefully evaluated. Under optimal extraction conditions, salting-out liquid-liquid extraction showed a better accuracy (84-96%) and precision (<14%) than dispersive liquid-liquid microextraction. Hence, a multi-biomarker method based on salting-out liquid-liquid extraction followed by gas chromatography with tandem mass spectrometry was proposed...
February 20, 2017: Journal of Separation Science
https://www.readbyqxmd.com/read/28217135/tps46-a-rice-terpene-synthase-conferring-natural-resistance-to-bird-cherry-oat-aphid-rhopalosiphum-padi-linnaeus
#13
Yang Sun, Xinzheng Huang, Yuese Ning, Weixia Jing, Toby J A Bruce, Fangjun Qi, Qixia Xu, Kongming Wu, Yongjun Zhang, Yuyuan Guo
Plant terpene synthases (TPSs) are key enzymes responsible for terpene biosynthesis, and can play important roles in defense against herbivore attack. In rice, the protein sequence of TPS46 was most closely related to maize TPS10. However, unlike maize tps10, tps46 was also constitutively expressed in rice even in the absence of herbivore attack. Potential roles or constitutive emissions of specific volatiles may due to the constitutive expressions of tps46 in rice. Therefore, in the present study, RNA interference (Ri) and overexpression (Oe) rice lines were generated to investigate the potential function of TPS46 in Oryza sativa sp...
2017: Frontiers in Plant Science
https://www.readbyqxmd.com/read/28217037/lung-injury-induced-skeletal-muscle-wasting-in-aged-mice-is-linked-to-alterations-in-long-chain-fatty-acid-metabolism
#14
D Clark Files, Amro Ilaiwy, Traci L Parry, Kevin W Gibbs, Chun Liu, James R Bain, Osvaldo Delbono, Michael J Muehlbauer, Monte S Willis
INTRODUCTION: Older patients are more likely to acquire and die from acute respiratory distress syndrome (ARDS) and muscle weakness may be more clinically significant in older persons. Recent data implicate muscle ring finger protein 1 (MuRF1) in lung injury-induced skeletal muscle atrophy in young mice and identify an alternative role for MuRF1 in cardiac metabolism regulation through inhibition of fatty acid oxidation. OBJECTIVES: To develop a model of lung injury-induced muscle wasting in old mice and to evaluate the skeletal muscle metabolomic profile of adult and old acute lung injury (ALI) mice...
August 2016: Metabolomics: Official Journal of the Metabolomic Society
https://www.readbyqxmd.com/read/28216888/effect-of-absolute-from-hibiscus-syriacus-l-flower-on-wound-healing-in-keratinocytes
#15
Seok Won Yoon, Kang Pa Lee, Do-Yoon Kim, Dae Il Hwang, Kyung-Jong Won, Dae Won Lee, Hwan Myung Lee
BACKGROUND: Proliferation and migration of keratinocytes are essential for the repair of cutaneous wounds. Hibiscus syriacus L. has been used in Asian medicine; however, research on keratinocytes is inadequate. OBJECTIVE: To establish the dermatological properties of absolute from Hibiscus syriacus L. flower (HSF) and to provide fundamental research for alternative medicine. MATERIALS AND METHODS: We identified the composition of HSF absolute using gas chromatography-mass spectrometry analysis...
January 2017: Pharmacognosy Magazine
https://www.readbyqxmd.com/read/28216594/anti-hyperglycemic-activity-of-major-compounds-from-calea-ternifolia
#16
Sonia Escandón-Rivera, Araceli Pérez-Vásquez, Andrés Navarrete, Mariana Hernández, Edelmira Linares, Robert Bye, Rachel Mata
Demethylisoencecalin (1) and caleins A (4) and C (5) (3.16-31.6 mg/kg, p.o.), the major components from an infusion of Calea ternifolia controlled postprandial glucose levels during an oral sucrose tolerance test (OSTT, 3 g/kg) in normal and nicotinamide/streptozotocin (NA/STZ, 40/100 mg/kg) hyperglicemic mice. The effects were comparable to those of acarbose (5 mg/kg). During the isolation of 1, 4, and 5, four additional metabolites not previously reported for the plant, were obtained, namely 6-acetyl-5-hydroxy-2-methyl-2-hydroxymethyl-2H-chromene (3), herniarin (6), scoparone (7), and 4',7-dimethylapigenin (8)...
February 14, 2017: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/28216091/enantiomeric-and-quantitative-analysis-of-volatile-terpenoids-in-different-teas-camellia-sinensis
#17
Yin Zhu, Chen-Yang Shao, Hai-Peng Lv, Yue Zhang, Wei-Dong Dai, Li Guo, Jun-Feng Tan, Qun-Hua Peng, Zhi Lin
Volatile terpenoids play important roles in the formation of tea aroma quality due to their pleasant scents and low odor thresholds. Most volatile terpenoids contain stereogenic centers, which results in various stereo distributions of their enantiomers and diastereoisomers in different types of tea. However, the distribution characteristics of terpenoid enantiomers in teas were still unclear, which poses an obstacle to the scientific understanding of tea aroma. In this work, a new and efficient analysis approach based on headspace solid phase microextraction (HS-SPME)-chiral gas chromatography-mass spectrometry (GC-MS) was established to analyze 12 pairs of familiar terpenoid enantiomers in different teas...
February 10, 2017: Journal of Chromatography. A
https://www.readbyqxmd.com/read/28215803/polycyclic-aromatic-hydrocarbons-pahs-produced-in-the-combustion-of-fatty-acid-alkyl-esters-from-different-feedstocks-quantification-statistical-analysis-and-mechanisms-of-formation
#18
Alberto Llamas, Ana-María Al-Lal, María-Jesús García-Martínez, Marcelo F Ortega, Juan F Llamas, Magín Lapuerta, Laureano Canoira
Polycyclic Aromatic Hydrocarbons (PAHs) are pollutants of concern due to their carcinogenic and mutagenic activity. Their emissions are mainly related with the combustion or pyrolysis of the organic matter, such as in fossil fuels combustion. It is important to characterize PAHs in the combustions of biofuels due to their increasing importance in the actual energetic setting. There is a lot of research focused in PAHs emission due to the combustion in diesel engines; but only few of them have analyzed the effect of raw material and type of alcohol used in the transesterification process...
February 16, 2017: Science of the Total Environment
https://www.readbyqxmd.com/read/28215548/identification-of-highly-sensitive-biomarkers-that-can-aid-the-early-detection-of-pancreatic-cancer-using-gc-ms-ms-based-targeted-metabolomics
#19
Yuichi Hirata, Takashi Kobayashi, Shin Nishiumi, Kodai Yamanaka, Takashi Nakagawa, Seiji Fujigaki, Takao Iemoto, Makoto Kobayashi, Takuji Okusaka, Shoji Nakamori, Masashi Shimahara, Takaaki Ueno, Akihiko Tsuchida, Naohiro Sata, Tatsuya Ioka, Yohichi Yasunami, Tomoo Kosuge, Takashi Kaneda, Takao Kato, Kazuhiro Yagihara, Shigeyuki Fujita, Tesshi Yamada, Kazufumi Honda, Takeshi Azuma, Masaru Yoshida
BACKGROUND: To improve prognosis of pancreatic cancer (PC) patients, the discovery of more reliable biomarkers for the early detection is desired. METHODS: Blood samples were collected by 2 independent groups. The 1st set was included 55 early PC and 58 healthy volunteers (HV), and the 2nd set was included 16 PC and 16HV. The 16 targeted metabolites were quantitatively analyzed by gas chromatography/tandem mass spectrometry together with their corresponding stable isotopes...
February 16, 2017: Clinica Chimica Acta; International Journal of Clinical Chemistry
https://www.readbyqxmd.com/read/28214830/hyper-elongation-in-colorectal-cancer-tissue-cerotic-acid-is-a-potential-novel-serum-metabolic-marker-of-colorectal-malignancies
#20
Adriana Mika, Jaroslaw Kobiela, Aleksandra Czumaj, Michał Chmielewski, Piotr Stepnowski, Tomasz Sledzinski
BACKGROUNDS/AIMS: Colorectal cancer (CRC) cells show some alterations of lipid metabolism. Elongation of fatty acids (FA) has not been studied in CRC tissues thus far. The aim of this study was to verify if CRC specimens and normal colon mucosa differ in terms of their levels of very long-chain FAs, a product of FA elongation. Moreover, the expression of elongase genes has been studied in normal tissue and CRC. Finally, we searched for some specific products of FA elongation in serum of CRC patients...
February 8, 2017: Cellular Physiology and Biochemistry
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