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https://www.readbyqxmd.com/read/28926788/study-of-the-degradation-process-of-ofloxacin-with-free-chlorine-by-using-esi-lcmsms-kinetic-study-by-products-formation-pathways-and-fragmentation-mechanisms
#1
Montaha H Yassine, Ahmad Rifai, Maha Hoteit, Patrick Mazellier, Mohammad Al Iskandarani
This study was conducted to gain a better understanding of the fate of fluoroquinolone antibacterial ofloxacin (OFX) which is the free available chlorine (FAC) in order to determine its effect during water chlorination process. The Direct reactions of FAC with OFX were quite rapid. A half-life of 7.7 s was measured under pseudo-first order conditions in the presence of an excess of total chlorine ([FAC]0 = 13 μM and [OFX]0 = 0.55 μM at pH 7.2 and 20 °C in buffered reagent water. Free chlorine reactions rates were of first-order type in both substrate and oxidant with specific second-order rate constants of 6...
September 4, 2017: Chemosphere
https://www.readbyqxmd.com/read/28925691/core-shell-mn7%C3%A2-mn-cd-12-assembled-from-core-mn7-disc
#2
Ling-Yu Guo, Hai-Feng Su, Mohamedally Kurmoo, Chen-Ho Tung, Di Sun, Lan-Sun Zheng
Post-synthetic decoration of the Mn7, {MnIII⊆MnII6}, core with CdII in the outer shell to form the next generation Mn13Cd6, {MnIII⊆MnIII3MnII3⊆ MnII6CdII6}, core-shell disc was achieved and confirmed by single-crystal X-ray diffraction. The formation of Mn13Cd6 has only been successful with Cd2+ and if the Cd salt is added within the first half hour window when the inner Mn7 has formed. EDX and ICP-AES gave the accurate content and confirm the average found by X-ray diffraction. HR-ESI-MS was even more precise by revealing three prominent molecular species, Mn13Cd6, Mn14Cd5 and Mn15Cd4, having a distribution of metals...
September 19, 2017: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/28925005/simultaneous-qualitative-and-quantitative-analyses-of-triterpenoids-in-ilex-pubescens-by-ultra-high-performance-liquid-chromatography-coupled-with-quadrupole-time-of-flight-mass-spectrometry
#3
Di Cao, Qing Wang, Jing Jin, Maosong Qiu, Lian Zhou, Xinghong Zhou, Hui Li, Zhongxiang Zhao
INTRODUCTION: Ilex pubescens Hook et Arn mainly contains triterpenoids that possess antithrombotic, anti-inflammatory and analgesic effects. Quantitative and qualitative analyses of the triterpenoids in I. pubescens can be useful for determining the authenticity and quality of raw materials and guiding its clinical preparation. OBJECTIVES: To establish a method for rapid and comprehensive analysis of triterpenoids in I. pubescens using ultra-high-performance liquid chromatography coupled to electrospray ionisation and quadrupole time-of-flight-mass spectrometry (UPLC-ESI-QTOF-MS), which will also be applied to evaluate the contents of nine triterpenoids among root, root heartwood and root bark of I...
September 18, 2017: Phytochemical Analysis: PCA
https://www.readbyqxmd.com/read/28924453/a-novel-and-efficient-fungal-delignification-strategy-based-on-versatile-peroxidase-for-lignocellulose-bioconversion
#4
Wen Kong, Xiao Fu, Lei Wang, Ahmad Alhujaily, Jingli Zhang, Fuying Ma, Xiaoyu Zhang, Hongbo Yu
BACKGROUND: The selective lignin-degrading white-rot fungi are regarded to be the best lignin degraders and have been widely used for reducing the saccharification recalcitrance of lignocellulose. However, the biological delignification and conversion of lignocellulose in biorefinery is still limited. It is necessary to develop novel and more efficient bio-delignification systems. RESULTS: Physisporinus vitreus relies on a new versatile peroxidase (VP)-based delignification strategy to remove enzymatic recalcitrance of corn stover efficiently, so that saccharification of corn stover was significantly enhanced to 349...
2017: Biotechnology for Biofuels
https://www.readbyqxmd.com/read/28922554/performance-comparison-of-dispersive-solid-phase-extraction-and-multiplug-filtration-cleanup-methods-for-the-determination-of-tefuryltrione-in-plant-and-environmental-samples-using-uhplc-ms-ms
#5
Yang Yu, Yan Tao, Fengshou Dong, Jun Xu, Xingang Liu, Xiaohu Wu, Mingshan Ji, Yongquan Zheng
The detection frequencies of tefuryltrione, a new type of 4-hydroxyphenyl-pyruvate dioxygenase inhibitor herbicide, are rarely reported, probably because of the paucity of analytical methods. Herein, an effective and sensitive analytical method has been developed to detect tefuryltrione in vegetables (tomato and cucumber), cereals (rice and corn), soil and water by ultra high performance liquid chromatography coupled with tandem mass spectrometry. Comparisons of the performances of dispersive solid-phase extraction and multiplug filtration cleanup methods were carried out for tefuryltrione in complex matrices...
September 18, 2017: Journal of Separation Science
https://www.readbyqxmd.com/read/28922514/the-complexity-of-oral-physiology-and-its-impact-on-salivary-diagnostics
#6
Eva J Helmerhorst, Colin Dawes, Frank G Oppenheim
OBJECTIVES: Saliva contains biomarkers for systemic as well as oral diseases. This study was undertaken to assess the variability in the sources of such biomarkers (plasma, cells), and attempted to identify saliva deterioration markers in order to improve saliva diagnostic outcomes. MATERIALS AND METHODS: Inter- and intra-subject variation in salivary gingival crevicular fluid levels were determined by measuring salivary albumin and transferrin levels. The purity of collected glandular secretions was determined by bacterial culture, and the variability in epithelial cell numbers by cell counting and optical density measurement...
September 18, 2017: Oral Diseases
https://www.readbyqxmd.com/read/28921887/chemical-components-biological-activities-and-toxicological-evaluation-of-the-fruit-aril-of-two-precious-plant-species-from-genus-taxus
#7
Na Li, Zheng Pan, Dan Zhang, Huaxing Wang, Bao Yu, Shengping Zhao, Jiajia Guo, Jianwei Wang, Ling Yao, Weiguo Cao
The fruit (aril) of the endangered genus Taxus plants is an abandoned herbal resource. Traditionally, people enthusiasticly focus on its bark, its renewable, tremendous arils fall into the soil with seeds after they are mature. The present research investigated the fruit of two species from the genus Taxus, Taxus chinensis var. mairei and Taxus media, with regards to their antioxidant and antihyperglycaemic activities, safety, and bioactive constituents. Results showed that T. chinensis var. mairei and T. media both had certain biological activities with T...
September 18, 2017: Chemistry & Biodiversity
https://www.readbyqxmd.com/read/28920989/half-sandwich-ru-ii-acylthiourea-complexes-dna-hsa-binding-anti-migration-and-cell-death-in-a-human-breast-tumor-cell-line
#8
Legna Colina-Vegas, Liany Luna-Dulcey, Ana M Plutín, Eduardo E Castellano, Marcia R Cominetti, Alzir A Batista
Organometallic ruthenium complexes as potential anticancer agents have been explored due to their suitable properties, such as stability in the solid state and in solution, water solubility and low toxicity. In this study, eight metal complexes of this class were synthesized, characterized and their important biological activities against a human breast tumor cell line (MDA-MB-231) were studied. Complexes 1-8 were obtained in good yields and have been characterized by satisfactory elemental analyses, IR, 1D and 2D (1)H and (13)C{(1)H} NMR, UV-Vis spectroscopy, cyclic voltammetry, ESI-MS and X-ray diffractometry (1, 2, 3 and 6)...
September 18, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
https://www.readbyqxmd.com/read/28920855/pfma-a-novel-quorum-quenching-n-acylhomoserine-lactone-acylase-from-pseudoalteromonas-flavipulchra
#9
Na Liu, Min Yu, Youbin Zhao, Jingguang Cheng, Ke An, Xiao-Hua Zhang
Many bacteria, such as Proteobacteria, Cyanobacteria and Bacteroidetes, use N-acylhomoserine lactones (AHLs) as quorum-sensing (QS) signal molecules for communication. Enzymatic degradation of AHLs, such as AHL acylase and AHL lactonase, can degrade AHLs (quorum quenching, QQ) to attenuate or disarm the virulence of pathogens. QQ is confirmed to be common in marine bacterial communities. Many genes encoding AHL acylases are found in marine bacteria and metagenomic collections, but only a few of these have been characterized in detail...
September 18, 2017: Microbiology
https://www.readbyqxmd.com/read/28919906/screening-for-natural-inhibitors-of-topoisomerases-i-from-rhamnus-davurica-by-affinity-ultrafiltration-and-high-performance-liquid-chromatography-mass-spectrometry
#10
Guilin Chen, Mingquan Guo
Topoisomerase I (Topo I) catalyzes topological interconversion of duplex DNA during DNA replication and transcription, and has been deemed as important antineoplastic targets. In this study, the fraction R.d-60 from ethyl acetate extracts of Rhamnus davurica showed higher inhibitory rates against SGC-7901 and HT-29 compared with the R.d-30 fraction in vitro. However, the specific active components of R.d-60 fraction remain elusive. To this end, a method based on bio-affinity ultrafiltration and high performance liquid chromatography/electrospray mass spectrometry (HPLC- ESI-MS/MS) was developed to rapidly screen and identify the Topo I inhibitors in this fraction...
2017: Frontiers in Plant Science
https://www.readbyqxmd.com/read/28918317/bithionol-residue-analysis-in-animal-derived-food-products-by-an-effective-and-rugged-extraction-method-coupled-with-liquid-chromatography-tandem-mass-spectrometry
#11
Weijia Zheng, Jin-A Park, A M Abd El-Aty, Seong-Kwan Kim, Sang-Hyun Cho, Jeong-Min Choi, Hee Yi, Soo-Min Cho, H A El-Banna, Jae-Han Shim, Byung-Joon Chang, Jing Wang, Jin-Suk Kim, Ho-Chul Shin
Herein, we developed a simple analytical procedure for the quantitation of bithionol residues in animal-derived food products such as porcine muscle, eggs, milk, eel, flatfish, and shrimp using a modified quick, easy, cheap, effective, rugged, and safe (QuEChERS) extraction method coupled with liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI(+)/MS-MS). Samples were extracted with 0.1% solution of formic acid in acetonitrile and the extract was purified using a C18 sorbent. Separation was performed on a Waters XBridge™ C18 reversed-phase analytical column using 0...
August 31, 2017: Journal of Chromatography. B, Analytical Technologies in the Biomedical and Life Sciences
https://www.readbyqxmd.com/read/28917751/structural-characterization-of-electrochemically-and-in-vivo-generated-potential-metabolites-of-selected-cardiovascular-drugs-by-ec-uhplc-esi-ms-using-an-experimental-design-approach
#12
Małgorzata Szultka-Młyńska, Sylwia Bajkacz, Irena Baranowska, Bogusław Buszewski
In the last few years, a number of studies were conducted which aimed at understanding the mechanisms of cardiovascular drug, metabolism, and there is still the need to determine the metabolites of cardiac drugs for the purpose of metabolism control. In this study, we employ a direct combination of electrochemical oxidation and mass spectrometric (EC-MS) identification for monitoring the oxidation pathway of ten cardiovascular drugs (metoprolol, propranolol, propafenone, mexiletine, oxprenolol, pirbuterol, pindolol, cicloprolol, acebutolol and atenolol)...
January 1, 2018: Talanta
https://www.readbyqxmd.com/read/28917733/stabilization-of-gas-phase-uranyl-complexes-enables-rapid-speciation-using-electrospray-ionization-and-ion-mobility-mass-spectrometry
#13
Austen L Davis, Brian H Clowers
Significant challenges exist when characterizing f-element complexes in solution using traditional approaches such as electrochemical and spectroscopic techniques as they do not always capture information for lower abundance species. However, provided a metal-complex with sufficient stability, soft ionization techniques such as electrospray offer a means to quantify and probe the characteristics of such systems using mass spectrometry. Unfortunately, the gas-phase species observed in ESI-MS systems do not always reflect the solution phase distributions due to the inherent electrochemical mechanism of the electrospray process, ion transfer from ambient to low pressures conditions, and other factors that are related to droplet evaporation...
January 1, 2018: Talanta
https://www.readbyqxmd.com/read/28917164/uplc-ms-ms-assay-of-riluzole-in-human-plasma-and-cerebrospinal-fluid-csf-application-in-samples-from-spinal-cord-injured-patients
#14
Mahua Sarkar, Robert G Grossman, Elizabeth G Toups, Diana S-L Chow
In the present study, a sensitive and robust LC-MS/MS method has been developed and validated for the quantification of riluzole in human plasma and cerebrospinal fluid (CSF) in clinical samples from patients with spinal cord injury (SCI). Riluzole and its labeled internal standard (IS) were isolated from plasma and CSF by liquid-liquid extraction using ethyl acetate. Riluzole (m/z 235→166) and IS (m/z 238→169) were detected by electrospray ionization (ESI) using multiple reaction monitoring (MRM) in a positive mode...
September 1, 2017: Journal of Pharmaceutical and Biomedical Analysis
https://www.readbyqxmd.com/read/28916542/comparative-effectiveness-of-tumor-necrosis-factor-agents-and-disease-modifying-antirheumatic-therapy-in-children-with-enthesitis-related-arthritis-the-first-year-after-diagnosis
#15
Pamela F Weiss, Rui Xiao, Timothy G Brandon, Ilaria Pagnini, Tracey B Wright, Timothy Beukelman, Esi Morgan-DeWitt, Chris Feudtner
OBJECTIVE: To characterize the effect of anti-tumor necrosis factor (TNF) therapy compared to conventional synthetic disease-modifying antirheumatic drugs (csDMARD) in children with enthesitis-related arthritis (ERA) over the first year after diagnosis. METHODS: We conducted a multicenter retrospective comparative effectiveness study of children diagnosed with ERA. We estimated the effect of anti-TNF therapy on clinical variables (active joint count, tender entheses count) and patient-reported pain and global assessment of disease activity over the first year after diagnosis using state-of-the-art comparative effectiveness analytic methods...
September 15, 2017: Journal of Rheumatology
https://www.readbyqxmd.com/read/28915313/a-metabolomic-approach-applied-to-a-liquid-chromatography-coupled-to-high-resolution-tandem-mass-spectrometry-method-hplc-esi-hrms-ms-towards-the-comprehensive-evaluation-of-the-chemical-composition-of-cannabis-medicinal-extracts
#16
Cinzia Citti, Umberto Maria Battisti, Daniela Braghiroli, Giuseppe Ciccarella, Martin Schmid, Maria Angela Vandelli, Giuseppe Cannazza
INTRODUCTION: Cannabis sativa L. is a powerful medicinal plant and its use has recently increased for the treatment of several pathologies. Nonetheless, side effects, like dizziness and hallucinations, and long-term effects concerning memory and cognition, can occur. Most alarming is the lack of a standardised procedure to extract medicinal cannabis. Indeed, each galenical preparation has an unknown chemical composition in terms of cannabinoids and other active principles that depends on the extraction procedure...
September 15, 2017: Phytochemical Analysis: PCA
https://www.readbyqxmd.com/read/28915036/collagen-peptides-from-crucian-skin-improve-calcium-bioavailability-and-structure-characterization-by-hplc-esi-ms-ms
#17
Tao Hou, Yanshuang Liu, Danjun Guo, Bo Li, Hui He
The effects of collagen peptides (CPs), which are derived from crucian skin, were investigated in a retinoic acid-induced bone loss model. The serum bone alkaline phosphatase (BALP) in model group (117.65±4.66 U/L) was significantly higher compared to other three groups (P<0.05). After treatment with 600 and 1200 mg/kg CPs, BALP decreased to 85.26±7.35 and 97.03±7.21 U/L, respectively. After treatment with 600 mg/kg CPs, bone calcium content significantly increased by 22% (femur) and 12.38% (tibia) compared to model group...
September 15, 2017: Journal of Agricultural and Food Chemistry
https://www.readbyqxmd.com/read/28913169/a-semi-virtual-two-dimensional-gel-electrophoresis-if-esi-lc-ms-ms
#18
Stanislav Naryzhny, Victor Zgoda, Artur Kopylov, Elena Petrenko, Аlexander Archakov
A method for increasing the productivity of ESI LC-MS/MS (electrospray ionization-liquid chromatography-tandem mass spectrometry) was proposed and applied. After IF (isoelectric focusing) of the sample using IPG (immobilized pH gradient) strip, the strip was cut to sections, and every section was treated according to trypsinolysis protocol for MS/MS analysis. The peptides produced were further analyzed by ESI LC-MS/MS. The procedure allows to: •identify many more proteins and proteoforms compared to shotgun analysis of extracts...
2017: MethodsX
https://www.readbyqxmd.com/read/28912066/the-camp-effectors-pka-and-epac-activate-endothelial-no-synthase-through-pi3k-akt-pathway-in-human-endothelial-cells
#19
Verónica García-Morales, María Luaces-Regueira, Manuel Campos-Toimil
3',5'-cyclic adenosine monophosphate (cAMP) exerts an endothelium-dependent vasorelaxant action by stimulating endothelial NO synthase (eNOS) activity, and the subsequent NO release, through cAMP protein kinase (PKA) and exchange protein directly activated by cAMP (Epac) activation in endothelial cells. We have here investigated the mechanism by which the cAMP-Epac/PKA pathway activates eNOS. cAMP-elevating agents (forskolin and dibutyryl-cAMP) and the joint activation of PKA (6-Bnz-cAMP) and Epac (8-pCPT-2'-O-Me-cAMP) increased cytoplasmic Ca(2+) concentration ([Ca(2+)]c) in ≤ 30% of fura-2-loaded isolated human umbilical vein endothelial cells (HUVEC)...
September 11, 2017: Biochemical Pharmacology
https://www.readbyqxmd.com/read/28910861/antioxidative-and-antiaging-activities-and-component-analysis-of-lespedeza-cuneata-g-don-extracts-fermented-with-lactobacillus-pentosus
#20
Joon Seob Seong, Song Hua Xuan, So Hyun Park, Keon Soo Lee, Young Min Park, Soo Nam Park
Lespedeza cuneata G. Don is a traditional herb that has been shown to associate with multiple biological activities. In this study, we investigated the antioxidative/antiaging activities and performed an active component analysis of the non-fermented and fermented (using Lactobacillus pentosus) extracts of Lespedeza cuneata G. Don. The antioxidative activities of the fermented extract were higher than those of non-fermented extracts. The elastase inhibitory activity, inhibitory effects on UV-induced MMP-1 expression, and ability to promote type I procollagen synthesis were investigated in Hs68 human fibroblasts cells...
September 15, 2017: Journal of Microbiology and Biotechnology
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