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https://www.readbyqxmd.com/read/29785949/-the-functions-of-yhcz-gene-during-bacillus-thuringiensis-growth
#1
Lin da Jia, Tan Tan Gao, Qi Peng, Jing Lv, Jie Zhang, Min Chen, Fu Ping Song
yhcZ and yhcY genes constitute a two-component system in Bacillus subtilis and B. cereus that regulates bacterial growth. However, the exact biological function of yhcZ gene in B. thuringiensis has not been fully elucidated. In this study, we proved that HD73_5824 is an yhcZ gene in B. thuringiensis subsp. kurstaki HD73 strain by combining gene functional annotation, analysis of upstream and downstream genes arrangement, and amino acid sequence alignment. This yhcZ gene may co-regulate bacterial growth with HD73_5825 gene (yhcY gene) by constituting a two-component system...
May 20, 2018: Yi Chuan, Hereditas
https://www.readbyqxmd.com/read/29784345/development-of-dried-serum-spot-sampling-techniques-for-the-assessment-of-trace-elements-in-serum-samples-by-la-icp-ms
#2
María Pilar Chantada-Vázquez, Jorge Moreda-Piñeiro, Alicia Cantarero-Roldán, Pilar Bermejo-Barrera, Antonio Moreda-Piñeiro
A novel approach for serum analysis by dried matrix spot (DMS) technique is proposed. The methodology consists of sampling filter paper discs (2.7 mm in diameter) containing the large amount of serum retained after a single spotting. Several oxidizers (sodium chlorate, sodium azide, acetic acid, formic acid, 1-butyl-3-methylimidazoliumm chloride/bromide) were tested (oxidizers premixed with the sample before spotting, and papers previously soaked in concentrated additive/oxidizer solutions). Direct multi-element determination (Al, Be, Ca, Cu, Fe, K, Li, Mg, Mn, Mo, Na, P, Rb, Se, V, and Zn) in dried serum spots at very low levels was therefore assessed by laser ablation (LA) coupled with inductively coupled plasma - mass spectrometry (ICP-MS)...
August 15, 2018: Talanta
https://www.readbyqxmd.com/read/29784339/quantification-of-peptides-in-human-synovial-fluid-using-liquid-chromatography-tandem-mass-spectrometry
#3
Araceli Garcia-Ac, Sung Vo Duy, Sébastien Sauvé, Florina Moldovan, V Gaëlle Roullin, Xavier Banquy
A method to explore the stability of two anti-inflammatory peptides in human synovial fluid (HSF) has been developed and validated using liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). The two peptides are BQ123 Cyclo(-D-Trp-D-Asp-L-Pro-D-Val-L-Leu, Mw = 610.7) and R-954 (AcOrn[Oic2 , (αMe)Phe5 , DβNal7 , Ile8 ]desArg9 -bradykinin, Mw = 1194.4). Human synovial fluid samples were analyzed after a protein precipitation step with acetonitrile and dilution with mobile phase. DMSO was used as anti-adsorptive agent...
August 15, 2018: Talanta
https://www.readbyqxmd.com/read/29784240/role-of-reactive-oxygen-species-on-the-activity-of-noble-metal-doped-tio-2-photocatalysts
#4
Paula Ribao, Juan Corredor, Maria J Rivero, Inmaculada Ortiz
Modified TiO2 catalysts are of interest in environmental water remediation since they can lead to efficient electron-hole separation and greatly enhance the photocatalytic properties of TiO2 . Reactive oxygen species (ROS), such as the superoxide radical (O2 - ), hydroxyl radical (OH), and positive valence band holes (h+ VB ), have been reported as the main oxidative species involved in photocatalytic degradation processes. In this work, the role of these species using TiO2 , TiO2 /Pt 0.5 wt%, and TiO2 /Ag 10 wt% has been examined in order to clarify the oxidation pathways...
May 15, 2018: Journal of Hazardous Materials
https://www.readbyqxmd.com/read/29783787/plasma-pharmacokinetic-determination-of-canagliflozin-and-its-metabolites-in-a-type-2-diabetic-rat-model-by-uplc-ms-ms
#5
Song-Tao Dong, Hui-Min Niu, Yin Wu, Jia-Lei Jiang, Ying Li, Kun-Yu Jiang, Xin Wang, Mao-Fan Zhang, Ming-Feng Han, Sheng-Nan Meng
Canagliflozin is a novel, orally selective inhibitor of sodium-dependent glucose co-transporter-2 (SGLT2) for the treatment of patients with type 2 diabetes mellitus. In this study, a sensitive and efficient UPLC-MS/MS method for the quantification of canagliflozin and its metabolites in rat plasma was established and applied to pharmacokinetics in a type 2 diabetic rat model. We firstly investigated the pharmacokinetic changes of canagliflozin and its metabolites in type 2 diabetic rats in order to use canagliflozin more safely, reasonably and effectively...
May 20, 2018: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/29783197/quantification-of-21-antihypertensive-drugs-in-serum-using-uhplc-ms-ms
#6
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/29783174/facile-isolation-of-%C3%AE-ribazole-from-vitamin-b-12-hydrolysates-using-boronate-affinity-chromatography
#7
Theodoric A Mattes, Jorge C Escalante-Semerena
Alpha-ribazole (α-R) is a unique riboside found in the nucleotide loop of coenzyme B12 (CoB12 ). α-R is not an intermediate of the de novo biosynthetic pathway of coenzyme B12 , but some bacteria of the phylum Firmicutes have evolved a two-protein system (transporter, kinase) that scavenges α-R from the environment and converts it to the pathway intermediate α-RP. Since α-R is not commercially available, one must either synthesize α-R, or isolate it from hydrolysates of vitamin B12 (cyano-B12 , CNB12 ), so the function of the above-mentioned proteins can be studied...
May 16, 2018: Journal of Chromatography. B, Analytical Technologies in the Biomedical and Life Sciences
https://www.readbyqxmd.com/read/29778874/simultaneous-determination-of-dihydrotestosterone-and-its-metabolites-in-mouse-sera-by-lc-ms-ms-with-chemical-derivatization
#8
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
https://www.readbyqxmd.com/read/29776454/determination-of-three-chromium-textile-azo-dyes-in-wastewater-by-spe-lc-esi-ms-ms
#9
Florina-Maria Copaciu, Dorina Simedru, Maria-Virginia Coman
In the present work, a procedure to determine three textile azo dyes, chromium-complexes [Nylosan Dark Brown (NDB), Lanasyn Dark Brown (LDB), and Lanasyn Red (LR)], from wastewater using solid-phase extraction (SPE) followed by LC-electrospray ionization negative mode tandem mass spectrometry (LC-ESI(-)-MS/MS) has been developed. The extraction/concentration and recovery degree of these dyes from liquid matrices were done on Strata WAX/NH₂ cartridges. The chromatographic separation was performed using a Luna C18 (2) 100Å column by isocratic elution with a methanol-acetonitrile-water (0...
May 18, 2018: Journal of AOAC International
https://www.readbyqxmd.com/read/29775840/development-of-a-lc-ms-method-for-simultaneous-determination-of-amoxicillin-and-metronidazole-in-human-serum-using-hydrophilic-interaction-chromatography-hilic
#10
Udani L Kathriarachchi, Sagar S Vidhate, Naser Al-Tannak, Alison H Thomson, Michael J J da Silva Neto, David G Watson
A method was developed for the determination of amoxicillin and metronidazole in human serum. The procedure used was hydrophilic interaction chromatography (HILIC) followed by mass spectrometric (MS) detection. Chromatographic separation was achieved on a ZIC-HILIC column and the mobile phase consisted of a mixture of 0.1% (v/v) formic acid in water and 0.1% (v/v) formic acid in acetonitrile. The method was validated with regard to selectivity, accuracy, precision, calibration, lower limit of quantification (LOQ), extraction recovery and matrix effect...
May 15, 2018: Journal of Chromatography. B, Analytical Technologies in the Biomedical and Life Sciences
https://www.readbyqxmd.com/read/29775811/determination-of-docetaxel-in-dried-blood-spots-by-lc-ms-ms-method-development-validation-and-clinical-application
#11
S Raymundo, V V Muller, N B Andriguetti, M Tegner, A C Artmann, H M Kluck, M A Franzoi, R M M Vilela, G Schwartsmann, R Linden, M V Antunes
In this study, a LC-MS/MS method for the measurement of docetaxel in Dried Blood Spots (DBS) samples was developed and validated. Docetaxel was extracted from 8 mm DBS punch with a mixture of methanol and acetonitrile (9:1, v/v). The chromatographic separation occurred in an Acquity® C18 column (150 × 2.1 mm, 1.7 μm) eluted with a mixture of water and acetonitrile plus 0.1% formic acid (45:55, v/v). Total analytical run time was 7 min. The method was linear from 50 to 3000 ng ml-1 . Precision assays showed CV% < 9...
May 15, 2018: Journal of Pharmaceutical and Biomedical Analysis
https://www.readbyqxmd.com/read/29775810/a-validated-uplc-ms-ms-method-for-the-quantitation-of-an-unstable-peptide-monocyte-locomotion-inhibitory-factor-mlif-in-human-plasma-and-its-application-to-a-pharmacokinetic-study
#12
Xuemei Liu, Pei Hu, Yongsheng Wang, Xizhu Wang, Jinghua Huang, Jin Li, Cheng Li, Hongyun Wang, Ji Jiang
Monocyte locomotion inhibitory factor (MLIF, Met-Gln-Cys-Asn-Ser), a pentapeptide with anti-inflammatory activity, was developed for neural protection in acute ischemic stroke. Determination of MLIF in human plasma samples is of great importance for pharmacokinetic evaluation in clinical studies. A reliable and sensitive method based on ultra-performance liquid chromatography coupled with tandem mass spectrometry (UPLC-MS/MS) was established for the measurement of MLIF in human plasma. Instability of peptide in matrix was the primary challenge in method development, which was properly resolved by addition of acidification reagents like sulfuric acid...
April 10, 2018: Journal of Pharmaceutical and Biomedical Analysis
https://www.readbyqxmd.com/read/29774326/first-identification-of-unstable-phosphino-formic-acid-h-2-pcooh
#13
Cheng Zhu, Robert Frigge, Andrew M Turner, Ralf I Kaiser, Bing-Jian Sun, Si-Ying Chen, Agnes H H Chang
The hitherto elusive phosphino formic acid molecule (H2PCOOH) was detected for the first time in the gas phase. Theoretical calculations revealed an unexpected kinetic stability of H2PCOOH compared to the isovalent carbamic acid (H2NCOOH) although the replacement of a single nitrogen atom by phosphorus decreases the bond order from a partial double (-C[double bond, length as m-dash]N-) to a single (-C-P-) bond. This work provides a fundamental framework to explore the synthesis and stability of derivatives of carbonic acid (H2CO3), in which one or both hydroxyl groups (OH) are replaced by hydride moieties involving third row atoms...
May 18, 2018: Chemical Communications: Chem Comm
https://www.readbyqxmd.com/read/29773374/electrospinning-and-wound-healing-activity-of-%C3%AE-chitin-extracted-from-cuttlefish-bone
#14
Hyeong-Seop Jung, Min Hee Kim, Ji Youn Shin, Se Ra Park, Ju-Young Jung, Won Ho Park
A nanofibrous β-chitin web was fabricated via electrospinning for use as a novel wound dressing material. β-chitin was extracted from cuttlefish bone using deproteinization and demineralization. First, cuttlefish bone was alkali-treated to remove the proteins and was then treated with the acid for demineralization. The extracted β-chitin was dissolved in formic acid as solvent to evaluate its electrospinnability, and the electrospinnability increased remarkably when β-chitin was blended with poly(ethylene oxide) (PEO) than without...
August 1, 2018: Carbohydrate Polymers
https://www.readbyqxmd.com/read/29771467/photochemically-driven-reverse-water-gas-shift-at-ambient-conditions-mediated-by-a-nickel-pincer-complex
#15
Felix Schneck, Florian Schendzielorz, Nareh Hatami, Markus Finger, Christian Würtele, Sven Schneider
The endothermic reverse water-gas shift reaction (rWGS) for direct CO2 hydrogenation to CO is an attractive approach to carbon utilization. However, direct CO2 hydrogenation with molecular catalysts generally gives formic acid instead of CO as a result of the selectivity of CO2 insertion into M-H bonds. Based on the photochemical inversion of this selectivity, several synthetic pathways are presented for CO selective CO2 reduction with a nickel pincer platform including the first example of a photodriven rWGS cycle at ambient conditions...
May 17, 2018: Angewandte Chemie
https://www.readbyqxmd.com/read/29770837/systematic-investigations-of-endogenous-cortisol-and-cortisone-in-nails-by-lc-ms-ms-and-correlation-to-hair
#16
Tina M Binz, Franziska Gaehler, Clarissa D Voegel, Mathias Hofmann, Markus R Baumgartner, Thomas Kraemer
Hair samples are increasingly used for measuring the long-term stress mediator cortisol. However, hair is not always available and nails (finger or toe), as a keratinized matrix, may be an alternative to hair. In order to measure cortisol and cortisone in the nail matrix, an LC-MS/MS method has been developed and validated using 13 C3 -labeled surrogate analytes. Both analytes were measured in ESI negative mode as formic acid adducts. Different sample preparation techniques were assessed, and single-step extraction in methanol was established for determination of cortisone and cortisol in the nail matrix...
May 17, 2018: Analytical and Bioanalytical Chemistry
https://www.readbyqxmd.com/read/29770593/stable-and-efficient-nitrogen-containing-carbon-based-electrocatalysts-for-reactions-in-energy-conversion-systems
#17
Sicong Wang, Zhenyuan Teng, Chengyin Wang, Guoxiu Wang
High activity and stability are crucial for practical electrocatalysts used for reactions in fuel cells, metal-air batteries and water electrolysis including ORR, HER, OER and oxidation reactions of formic acid and alcohols. N-C based electrocatalysts have shown promising prospects for catalyzing these reactions, however, there is no systematic review for strategies toward engineering active and stable N-C based electrocatalysts reported by far. Herein, a comprehensive comparison of recently reported N-C based electrocatalysts regarding both electrocatalytic activity and long-term stability is presented...
May 17, 2018: ChemSusChem
https://www.readbyqxmd.com/read/29768902/controlled-synthesis-of-hierarchical-pd-nanodendrites-and-their-electrocatalytic-properties
#18
Huan Wang, Beibei Zeng, Yanxi Zhao, Mei Li, Hanfan Liu, Tao Huang
Well-defined hierarchical Pd nanodendrites with (111) surface were successfully synthesized with Pd(acac)2 as a precursor, polyvinylpyrrolidone (PVP) as a stabilizer, CO as a reducing agent in the presence of appropriate amounts of NaAc and oleylamide (OAm) at 100 °C for 3 h under atmospheric pressure. OAm played an important role in controlling the growth of the hierarchical dendritic nanostructures of the final products. The formation of the hierarchical Pd dendrites was ascribed to the OAm-confined growth from the tips along 〈111〉 axis directions...
January 1, 2018: Journal of Nanoscience and Nanotechnology
https://www.readbyqxmd.com/read/29768657/simultaneous-quantification-of-fentanyl-sufentanil-cefazolin-doxapram-and-keto-doxapram-in-plasma-using-liquid-chromatography-tandem-mass-spectrometry
#19
Robert B Flint, Soma Bahmany, Bart C H van der Nagel, Birgit C P Koch
A simple and specific UPLC-MS/MS method was developed and validated for simultaneous quantification of fentanyl, sufentanil, cefazolin, doxapram and its active metabolite keto-doxapram. The internal standard was fentanyl-d5 for all analytes. Chromatographic separation was achieved with a reversed phase Acquity UPLC HSS T3 column with a run-time of only 5.0 minutes per injected sample. Gradient elution was performed with a mobile phase consisting of ammonium acetate, formic acid in Milli-Q ultrapure water or in methanol with a total flow rate of 0...
May 16, 2018: Biomedical Chromatography: BMC
https://www.readbyqxmd.com/read/29767301/capillary-electrophoresis-tandem-mass-spectrometry-for-multiclass-analysis-of-polar-marine-toxins
#20
Daniel G Beach, Elliott S Kerrin, Krista Thomas, Michael A Quilliam, Pearse McCarron
Polar marine toxins are more challenging to analyze by mass spectrometry-based methods than lipophilic marine toxins, which are now routinely measured in shellfish by multiclass reversed-phase liquid chromatography-tandem mass spectrometry (MS/MS) methods. Capillary electrophoresis (CE)-MS/MS is a technique that is well suited for the analysis of polar marine toxins, and has the potential of providing very high resolution separation. Here, we present a CE-MS/MS method developed, with use of a custom-built interface, for the sensitive multiclass analysis of paralytic shellfish toxins, tetrodotoxins, and domoic acid in seafood...
May 16, 2018: Analytical and Bioanalytical Chemistry
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