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https://www.readbyqxmd.com/read/28741315/a-mass-spectrometry-and-dft-study-of-pyrithione-complexes-with-transition-metals-in-the-gas-phase
#1
Matias Butler, Gabriela M Cabrera
2-mercaptopyridine N-oxide (pyrithione, PTOH) along with several transition metal ions forms coordination compounds displaying notable biological activities. Gas-phase complexes formed between pyrithione and Manganese (II), Cobalt (II), Nickel (II), Copper (II) and Zinc (II) were investigated by infusion in the electrospray source of a quadrupole-time of flight mass spectrometer. Remarkably, positive ion mode spectra displayed the singly charged metal adduct ion [C10 H8 MN2 O2 S2 ](2+) ([M(PTO)2 ](+•) or [M(DPTO)](+•) ), where DPTO is dipyrithione, 2,2'-dithiobis(pyridine N-oxide), among the most abundant peaks, implying a change in the oxidation state of whether the metal ion or the ligands...
July 24, 2017: Journal of Mass Spectrometry: JMS
https://www.readbyqxmd.com/read/28740564/can-diffusion-weighted-imaging-aid-in-differentiating-benign-from-malignant-sinonasal-masses-a-useful-adjunct
#2
Abanti Das, Ashu S Bhalla, Raju Sharma, Atin Kumar, Alok Thakar, Sreenivas M Vishnubhatla, Mehar C Sharma, Suresh C Sharma
BACKGROUND: To evaluate the role of diffusion weighted imaging (DWI) and apparent diffusion coefficient (ADC) values at 3 Tesla in characterizing sinonasal masses. MATERIAL/METHODS: After ethical clearance, 79 treatment naive patients with head and neck masses underwent magnetic resonance imaging (MRI), including DWI at 3 Tesla using the following b values - 0, 500 and 1000 s/mm(2). Thirty-one patients were found to have sinonasal tumours and were subsequently analysed...
2017: Polish Journal of Radiology
https://www.readbyqxmd.com/read/28739119/structural-and-functional-empirical-and-modeled-connectivity-in-the-cerebral-cortex-of-the-rat
#3
Antonio Díaz-Parra, Zachary Osborn, Santiago Canals, David Moratal, Olaf Sporns
Connectomics data from animal models provide an invaluable opportunity to reveal the complex interplay between structure and function in the mammalian brain. In this work, we investigate the relationship between structural and functional connectivity in the rat brain cortex using a directed anatomical network generated from a carefully curated meta-analysis of published tracing data, along with resting-state functional MRI data obtained from a group of 14 anesthetized Wistar rats. We found a high correspondence between the strength of functional connections, measured as blood oxygen level dependent (BOLD) signal correlations between cortical regions, and the weight of the corresponding anatomical links in the connectome graph (maximum Spearman rank-order correlation ρ=0...
July 21, 2017: NeuroImage
https://www.readbyqxmd.com/read/28738591/procedures-for-precise-measurements-of-135-cs-137-cs-atom-ratios-in-environmental-samples-at-extreme-dynamic-ranges-and-ultra-trace-levels-by-thermal-ionization-mass-spectrometry
#4
James A Dunne, David A Richards, Hsin-Wei Chen
Determination of (135)Cs/(137)Cs atom ratios has the potential to be a powerful tool for nuclear forensics and monitoring environmental processes. We present optimized chemical separation techniques and thermal ionization mass spectrometry (TIMS) protocols to obtain precise (135)Cs/(137)Cs atom ratios for a range of environmental sample types. We use a combination of double AMP-PAN separation and Sr-spec resin column purification to yield excellent separation from the alkali metals (Rb separation factor > 600), which normally suppress ionization of Cs...
November 1, 2017: Talanta
https://www.readbyqxmd.com/read/28738557/multielemental-analysis-of-18-essential-and-toxic-elements-in-amniotic-fluid-samples-by-icp-ms-full-procedure-validation-and-estimation-of-measurement-uncertainty
#5
B Markiewicz, A Sajnóg, W Lorenc, A Hanć, I Komorowicz, J Suliburska, R Kocyłowski, D Barałkiewicz
Amniotic fluid is the substantial factor in the development of an embryo and fetus due to the fact that water and solutes contained in it penetrate the fetal membranes in an hydrostatic and osmotic way as well as being swallowed by the fetus. Elemental composition of amniotic fluid influences the growth and health of the fetus, therefore, an analysis of amniotic fluid is important because the results would indicate abnormal levels of minerals or toxic elements. Inductively coupled plasma mass spectroscopy (ICP-MS) is often used for determination of trace and ultra-trace level elements in a wide range of matrices including biological samples because of its unique analytical capabilities...
November 1, 2017: Talanta
https://www.readbyqxmd.com/read/28737889/application-of-resonance-ionization-mass-spectrometry-for-ultra-trace-analysis-of-technetium
#6
Pascal Schönberg, Christoph Mokry, Jörg Runke, Daniela Schönenbach, Nils Stöbener, Petra Thörle-Pospiech, Norbert Trautmann, Tobias Reich
This work shows the capability of Resonance Ionization Mass Spectrometry (RIMS) for the determination of (99g)Tc at the ultra-trace level. The characterization of the prepared samples by X-Ray Photoelectron Spectroscopy (XPS) and optimization of the RIMS setup for this purpose as well as the application of the RIMS method to a soil sample are presented. (97)Tc was used as a tracer isotope to determine the amount of (99g)Tc in a soil sample with RIMS. With 8.8 · 10(10) atoms (97)Tc as tracer, the concentration of (99g)Tc amounts to 1...
July 24, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28737378/quantitative-mid-infrared-cavity-ringdown-detection-of-methyl-iodide-for-monitoring-applications
#7
Ibrahim Sadiek, Qiang Shi, Douglas Wallace, Gernot Friedrichs
Methyl iodide is a toxic halocarbon with diverse industrial and agricultural applications and is an important ocean-derived trace gas that contributes to the iodine burden of the atmosphere. Quantitative analysis of CH3I is mostly based on gas chromatography coupled with mass spectrometry or electron capture detection (GC-MS/ECD) as yet, which often limits the ability to conduct in situ high-frequency monitoring studies. This work presents an alternative detection scheme based on mid-infrared continuous wave cavity ringdown spectroscopy (mid-IR cw-CRDS)...
July 24, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28737033/rapid-identification-of-meat-species-by-the-internal-extractive-electrospray-ionization-mass-spectrometry-of-hemoglobin-selectively-extracted-on-functionalized-graphene-oxide
#8
Lili Song, Jiaquan Xu, Konstantin Chingin, Tenggao Zhu, Yue Zhang, Yong Tian, Huanwen Chen, Xuwei Chen
Hemoglobin (Hb) present in the blood and meat juice samples was selectively adsorbed by graphene oxide (GO) particles functionalized with amylopectin (AP) and was sensitively detected by the direct internal extractive electrospray ionization mass spectrometry (iEESI-MS) analysis for the identification of meat type. Various samples including the whole blood samples of chicken, duck, sheep, mouse, pigeon, turtledove and meat juice mixtures were successfully identified based on the difference in molecular composition of Hb reflected in MS...
July 24, 2017: Journal of Agricultural and Food Chemistry
https://www.readbyqxmd.com/read/28734785/impact-of-magnetic-stirring-on-stainless-steel-integrity-effect-on-biopharmaceutical-processing
#9
Christopher Thompson, Kelly Wilson, Yoen Joo Kim, Min Xie, William K Wang, Michaela Wendeler
Stainless steel containers are widely used in the pharmaceutical and biopharmaceutical industry for the storage of buffers, process intermediates, and purified drug substance. They are generally held to be corrosion resistant, biocompatible, and non-reactive, although it is well established that trace amounts of metal ions can leach from stainless steel equipment into biopharmaceutical products. We report here that the use of stainless steel containers in conjunction with magnetic stirring bars leads to significantly aggravated metal contamination, consisting both of metal particles and significantly elevated metal ions in solution, the degree of which is several orders of magnitude higher than described for static conditions...
July 19, 2017: Journal of Pharmaceutical Sciences
https://www.readbyqxmd.com/read/28734355/highly-sensitive-strategy-for-identification-of-trace-chemicals-in-complex-matrix-application-to-analysis-of-monacolin-analogues-in-monascus-fermented-rice-product
#10
Meng-Ning Li, Chao-Ran Li, Wen Gao, Ping Li, Hua Yang
Trace analysis of chemical analogues was always a hot topic and attracted the researchers' attentions. In this study, a database/multi-step filtering strategy was developed by using HPLC-Chip-MS system for comprehensive characterization of monacolin analogues in monascus-fermented rice product (MFRP). This strategy mainly included three steps, including chemical profile of MFRP by HPLC-Chip-MS, establishment of monacolin analogue database, multi-step filtering of monacolins based on modified mass defect filtering...
August 22, 2017: Analytica Chimica Acta
https://www.readbyqxmd.com/read/28734042/multivariate-optimization-of-conditions-for-digestion-of-wet-feeds-for-dogs-and-cats-using-a-closed-digester-block-and-multielement-determination-by-icp-oes
#11
Dayara Virgínia Lino Ávila, Sidnei Oliveira Souza, Silvlvânio Silvlvério Lopes Costa, Carlos Alexandre Borges Garcia, José do Patrocínio Hora Alvlves, Rennan Geovanny Oliveira Araujo, Elisangela Andrade Passos
A full 2⁴ factorial design was applied to find the best combination of diluted reagents (HNO₃ and H₂O₂), time, and temperature for the digestion of samples of wet feed for dogs and cats using a closed digestion block. The residual carbon concentration (RCC) was used as the response in the factorial design. All variables and their interactions significantly influenced the digestion of the feed samples, as indicated by the RCC. The conditions established for the digestion of 0.05 g (dry mass) wet feed samples were the addition of 3...
July 21, 2017: Journal of AOAC International
https://www.readbyqxmd.com/read/28733443/direct-metabolic-interrogation-of-dihydrotestosterone-biosynthesis-from-adrenal-precursors-in-primary-prostatectomy-tissues
#12
Charles Dai, Yoon-Mi Chung, Evan Kovac, Ziqi Zhu, Jianneng Li, Cristina Magi-Galluzzi, Andrew J Stephenson, Eric A Klein, Nima Sharifi
Purpose: A major mechanism of castration-resistant prostate cancer (CRPC) involves intratumoral biosynthesis of dihydrotestosterone (DHT) from adrenal precursors. We have previously shown that adrenal-derived androstenedione (AD) is the preferred substrate over testosterone (T) for 5α-reductase expressed in metastatic CRPC, bypassing T as an obligate precursor to DHT. However, the metabolic pathway of adrenal-derived DHT biosynthesis has not been rigorously investigated in the setting of primary disease in the prostate...
July 21, 2017: Clinical Cancer Research: An Official Journal of the American Association for Cancer Research
https://www.readbyqxmd.com/read/28732168/inland-sea-spray-aerosol-transport-and-incomplete-chloride-depletion-varying-degrees-of-reactive-processing-observed-during-soas
#13
Amy Lynne Bondy, Bingbing Wang, Alexander Laskin, Rebecca Lynn Craig, Manelisi Victor Nhliziyo, Steven Bertman, Kerri A Pratt, Paul B Shepson, Andrew P Ault
Multiphase reactions involving sea spray aerosol (SSA) impact trace gas budgets in coastal regions by acting as a reservoir for oxidized nitrogen and sulfur species, as well as a source of halogen gases (HCl, ClNO2, etc.). While most studies of multiphase reactions on SSA have focused on marine environments, far less is known about SSA transported inland. Herein, single particle measurements of SSA are reported at a site > 320 km from the Gulf of Mexico, with transport times of 7-68 h. Samples were collected during the Southern Oxidant and Aerosol Study (SOAS) in June-July 2013 near Centreville, Alabama...
July 21, 2017: Environmental Science & Technology
https://www.readbyqxmd.com/read/28731295/biogeochemistry-of-lead-its-release-to-the-environment-and-chemical-speciation
#14
Jay T Cullen, Jason McAlister
Lead (Pb) is a metal that is not essential for life processes and proves acutely toxic to most organisms. Compared to other metals Pb is rather immobile in the environment but still its biogeochemical cycling is greatly perturbed by human activities. In this review we present a summary of information describing the physical and chemical properties of Pb, its distribution in crustal materials, and the processes, both natural and anthropogenic, that contribute to the metal's mobilization in the biosphere. The relatively high volatility of Pb metal, low melting point, its large ionic radius, and its chemical speciation in aquatic systems contributes to its redistribution by anthropogenic and natural processes...
April 10, 2017: Metal Ions in Life Sciences
https://www.readbyqxmd.com/read/28726692/chemical-speciation-of-trace-metals-in-the-industrial-sludge-of-dhaka-city-bangladesh
#15
Md Saiful Islam, Md Habibullah Al-Mamun, Ye Feng, Masahiro Tokumura, Shigeki Masunaga
The objective of this study was to assess total concentration and chemical fractionation of trace metals in the industrial wastewater and sludge collected from seven different types of industries in Dhaka City, Bangladesh. The sludge from industries is either dumped on landfills or reused as secondary resources in order to preserve natural resources. Metals were analyzed using inductively coupled plasma mass spectrometry (ICP-MS). The ranges of Cr, Ni, Cu, As, Cd, and Pb in the sludges were 1.4-9,470, 4.8-994, 12...
July 2017: Water Science and Technology: a Journal of the International Association on Water Pollution Research
https://www.readbyqxmd.com/read/28726388/detection-of-pesticide-residues-in-food-using-surface-enhanced-raman-spectroscopy-a-review
#16
Menglei Xu, Yu Gao, Xiao Xia Han, Bing Zhao
Pesticides directly pollute the environment and contaminate foods ultimately being absorbed by the human body. Their residues contain highly toxic substances that have been found to cause serious problems to human health even at very low concentrations. The gold standard method, gas/liquid chromatography combined with mass spectroscopy, has been widely used for the detection of pesticide residues. However, these methods have some drawbacks such as complicated pre-treatment and cleanup steps. Recent technological advancements of surface-enhanced Raman spectroscopy (SERS) has promoted the creation of alternative detection techniques...
July 20, 2017: Journal of Agricultural and Food Chemistry
https://www.readbyqxmd.com/read/28725970/ion-release-in-ceramic-bearings-for-total-hip-replacement-results-from-an-in-vitro-and-an-in-vivo-study
#17
Jan Philippe Kretzer, Ulrike Mueller, Marcus R Streit, Hartmuth Kiefer, Robert Sonntag, Robert M Streicher, Joern Reinders
INTRODUCTION: Literature on the potential release of trace elements following implantation of Zirconia-platelet toughened alumina (ZPTA) ceramic components is scant. The present study therefore analysed the in vitro and in vivo potential release of ions from ZPTA bearings. MATERIAL AND METHODS: An in vitro and in vivo study was conducted. The in vitro study compared leaching in bovine serum from two groups: ZPTA ceramic heads and Co-28Cr-6Mo alloy heads, both 28-mm diameter...
July 20, 2017: International Orthopaedics
https://www.readbyqxmd.com/read/28725442/identification-of-dust-storm-origin-in-south-west-of-iran
#18
Parya Broomandi, Bahram Dabir, Babak Bonakdarpour, Yousef Rashidi
BACKGROUND: Deserts are the main sources of emitted dust, and are highly responsive to wind erosion. Low content of soil moisture and lack of vegetation cover lead to fine particle's release. One of the semi-arid bare lands in Iran, located in the South-West of Iran in Khoozestan province, was selected to investigate Sand and Dust storm potential. METHODS: This paper focused on the metrological parameters of the sampling site, their changes and the relationship between these changes and dust storm occurrence, estimation of Reconaissance Drought Index, the Atterberg limits of soil samples and their relation with soil erosion ability, the chemical composition, size distribution of soil and airborne dust samples, and estimation of vertical mass flux by COMSALT through considering the effect of saffman force and interparticle cohesion forces during warm period (April-September) in 2010...
2017: Journal of Environmental Health Science & Engineering
https://www.readbyqxmd.com/read/28722817/dispersive-solid-phase-extraction-for-the-determination-of-trace-organochlorine-pesticides-in-apple-juices-using-reduced-graphene-oxide-coated-with-zno-nanocomposites-as-sorbent
#19
Ting Sun, Hefeng Sun, Feng Zhao
In this work, reduced graphene oxide coated with ZnO nanocomposites was used as an efficient sorbent of dispersive solid-phase extraction and successfully applied to extraction of organochlorine pesticides from apple juice followed by gas chromatography with mass spectrometry. Several experimental parameters affecting the extraction efficiencies, including the amount of adsorbent, extraction time, and the pH of the sample solution, as well as the type and volume of eluent solvent, were investigated and optimized...
July 19, 2017: Journal of Separation Science
https://www.readbyqxmd.com/read/28718023/two-year-survey-of-specific-hospital-wastewater-treatment-and-its-impact-on-pharmaceutical-discharges
#20
Laure Wiest, Teofana Chonova, Alexandre Bergé, Robert Baudot, Frédérique Bessueille-Barbier, Linda Ayouni-Derouiche, Emmanuelle Vulliet
It is well known that pharmaceuticals are not completely removed by conventional activated sludge wastewater treatment plants. Hospital effluents are of major concern, as they present high concentrations of pharmaceutically active compounds. Despite this, these specific effluents are usually co-treated with domestic wastewaters. Separate treatment has been recommended. However, there is a lack of information concerning the efficiency of separate hospital wastewater treatment by activated sludge, especially on the removal of pharmaceuticals...
July 17, 2017: Environmental Science and Pollution Research International
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