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https://www.readbyqxmd.com/read/29332808/a-polyethyleneimine-modified-attapulgite-as-a-novel-solid-support-in-matrix-solid-phase-dispersion-for-the-extraction-of-cadmium-traces-in-seafood-products
#1
Tingting Wang, Yihui Chen, Junfeng Ma, Zhenfeng Jin, Mengsa Chai, Xunwen Xiao, Lihua Zhang, Yukui Zhang
In current study, a new polyethyleneimine (PEI)-modified attapulgite material was prepared serving as a solid support in matrix solid-phase dispersion for the extraction and determination (by atomic absorption spectrometry) of cadmium in seafood products. The major factors affecting PEI grafting were optimized using various PEI amounts and molecular weights. Parameters pivotal to MSPD extraction efficiency, like: pH, volume of eluting solvent, and the sorbent mass-to-sample ratio were investigated. Quantitative recoveries were achieved with 0...
April 1, 2018: Talanta
https://www.readbyqxmd.com/read/29332417/-concise-history-of-toxicology-from-empiric-knowledge-to-science
#2
Anna Tompa, Péter Balázs
Toxicology is a science of poisonings by xenobiotics and endogenous physiological changes. Its empiric roots may be traced back to the emerging of the human race because the most important pledge of our predecessors' survival was the differentiation between eatable and poisonous plants and animals. In the course of social evolution, there were three main fields of using poisons: 1) hunting and warfare, 2) to settle social tensions by avoiding military conflicts through hiding strategy of eliminating enemies by toxic substances, 3) medicines applied first as anti-poisons and later by introducing strong substances to defeat diseases, but paradoxically active euthanasia is also a part of the whole story...
January 2018: Orvosi Hetilap
https://www.readbyqxmd.com/read/29331742/a-sensitive-and-selective-immunoaffinity-column-clean-up-coupled-to-uplc-ms-ms-for-determination-of-trace-methyl-3-quinoxaline-2-carboxylic-acid-in-animal-tissues
#3
Peipei Li, Xiaojun Zhang, Juanmei Zhang, Zhongyong Yan, Shuai Zhang, Si Chen, Yi Fang
This paper described a reliable and simple method for the selective determination of MQCA in animal tissues using ultra high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). A highly targeted immunoaffinity column was used for sample purification after enzymatic hydrolysis. The purified extracts were analyzed by reversed-phase HPLC-MS/MS in positive ESI and multiple reaction monitoring mode. The calibration curves showed good linearity with correlation coefficient (r2) larger than 0...
January 3, 2018: Journal of Chromatography. B, Analytical Technologies in the Biomedical and Life Sciences
https://www.readbyqxmd.com/read/29330963/metal-organic-framework-based-in-syringe-solid-phase-extraction-for-the-on-site-sampling-of-polycyclic-aromatic-hydrocarbons-from-environmental-water-samples
#4
Xiaoqiong Zhang, Peiyi Wang, Qiang Han, Hengzhen Li, Tong Wang, Mingyu Ding
In-syringe solid-phase extraction is a promising sample pretreatment method for the on-site sampling of water samples because of its outstanding advantages of portability, simple operation, short extraction time and low cost. In this work, a novel in-syringe solid-phase extraction device using metal-organic frameworks as the adsorbent was fabricated for the on-site sampling of polycyclic aromatic hydrocarbons from environmental waters. Trace polycyclic aromatic hydrocarbons were effectively extracted through the self-made device followed by gas chromatography with mass spectrometry analysis...
January 13, 2018: Journal of Separation Science
https://www.readbyqxmd.com/read/29330441/pathway-design-using-de-novo-steps-through-uncharted-biochemical-spaces
#5
Akhil Kumar, Lin Wang, Chiam Yu Ng, Costas D Maranas
Existing retrosynthesis tools generally traverse production routes from a source to a sink metabolite using known enzymes or de novo steps. Generally, important considerations such as blending known transformations with putative steps, complexity of pathway topology, mass conservation, cofactor balance, thermodynamic feasibility, microbial chassis selection, and cost are largely dealt with in a posteriori fashion. The computational procedure we present here designs bioconversion routes while simultaneously considering any combination of the aforementioned design criteria...
January 12, 2018: Nature Communications
https://www.readbyqxmd.com/read/29329151/gadolinium-retention-brain-t1-hyperintensity-and-endogenous-metals-a-comparative-study-of-macrocyclic-versus-linear-gadolinium-chelates-in-renally-sensitized-rats
#6
Marlène Rasschaert, Andréa Emerit, Nathalie Fretellier, Cécile Factor, Philippe Robert, Jean-Marc Idée, Claire Corot
OBJECTIVES: This preclinical study was designed to compare gadolinium (Gd) brain uptake after repeated injections of a macrocyclic Gd-based contrast agent (GBCA) (gadoterate meglumine) or 2 linear GBCAs (L-GBCAs) (gadobenate dimeglumine or gadodiamide) on a translational model of moderate renal impairment in rats. METHODS: The study was carried out in subtotally nephrectomized rats. Animals received 4 intravenous injections per week of GBCA (gadoterate meglumine, gadobenate dimeglumine, or gadodiamide) for 5 weeks, resulting in a cumulative dose of 12 mmol/kg, followed by a 1-month injection-free period...
January 12, 2018: Investigative Radiology
https://www.readbyqxmd.com/read/29328885/radiographic-emphysema-circulating-bone-biomarkers-and-progressive-bone-mineral-density-loss-in-smokers
#7
Jessica Bon, Yingze Zhang, Joseph K Leader, Carl Fuhrman, Subashan Perera, Divay Chandra, Marnie Bertolet, Brenda Diergaarde, Susan L Greenspan, Frank C Sciurba
RATIONALE: Osteoporosis is common in individuals with chronic obstructive pulmonary disease. Lung-specific factors, including radiographic emphysema, independently associate with low bone mineral density (BMD) in cross-sectional smoking cohorts. However, factors associated with progressive bone loss in smokers are under-studied and largely unknown. OBJECTIVES: To determine the relationship between radiographic emphysema, circulating bone metabolism markers, and pulmonary function and accelerated BMD loss in smokers...
January 12, 2018: Annals of the American Thoracic Society
https://www.readbyqxmd.com/read/29328674/new-insights-on-ecosystem-mercury-cycling-revealed-by-stable-isotopes-of-mercury-in-water-flowing-from-a-headwater-peatland-catchment
#8
Glenn Woerndle, Martin Tsz-Ki Tsui, Stephen Sebestyen, Joel D Blum, Xiangping Nie, Randall K Kolka
Stable isotope compositions of mercury (Hg) were measured in the outlet stream and in soil cores at different landscape positions in a 9.7-ha boreal upland-peatland catchment in northern Minnesota. An acidic permanganate/persulfate digestion procedure was validated for water samples with high dissolved organic matter (DOM) concentrations and we verified the complete breakdown of DOM through Hg spike addition analysis. We report a relatively large variation in mass-dependent fractionation (δ202Hg; from -2.12 to -1...
January 12, 2018: Environmental Science & Technology
https://www.readbyqxmd.com/read/29327028/transition-metals-and-trace-elements-in-the-retinal-pigment-epithelium-and-choroid-correlative-ultrastructural-and-chemical-analysis-by-analytical-electron-microscopy-and-nano-secondary-ion-mass-spectrometry
#9
Antje Biesemeier, Oliver Eibl, Santhana Eswara, Jean-Nicolas Audinot, Tom Wirtz, Ulrich Schraermeyer
Understanding the localisation and abundance of structural elements, trace elements and especially transition metals like Cu and Zn in ocular tissue sections is important for physiology, and also for the characterisation of diseases related to oxidative stress like age-related macular degeneration. Transition metal abundances were investigated in an aged donor eye by nano-secondary ion mass spectrometry (nano-SIMS) elemental mapping using Cs+ and O- primary ions, respectively, and correlated to their respective mole fractions investigated by analytical electron microscopy (AEM)...
January 12, 2018: Metallomics: Integrated Biometal Science
https://www.readbyqxmd.com/read/29326980/increased-fluxes-of-shelf-derived-materials-to-the-central-arctic-ocean
#10
Lauren E Kipp, Matthew A Charette, Willard S Moore, Paul B Henderson, Ignatius G Rigor
Rising temperatures in the Arctic Ocean region are responsible for changes such as reduced ice cover, permafrost thawing, and increased river discharge, which, together, alter nutrient and carbon cycles over the vast Arctic continental shelf. We show that the concentration of radium-228, sourced to seawater through sediment-water exchange processes, has increased substantially in surface waters of the central Arctic Ocean over the past decade. A mass balance model for 228Ra suggests that this increase is due to an intensification of shelf-derived material inputs to the central basin, a source that would also carry elevated concentrations of dissolved organic carbon and nutrients...
January 2018: Science Advances
https://www.readbyqxmd.com/read/29324657/%C3%AE-glucosidase-inhibition-and-antibacterial-activity-of-secondary-metabolites-from-the-ecuadorian-species-clinopodium-taxifolium-kunth-govaerts
#11
Vladimir Morocho, Andrea Valle, Jessica García, Gianluca Gilardoni, Luis Cartuche, Alírica I Suárez
The phytochemical investigation of both volatile and fixed metabolites of Clinopodium taxifolium (Kunth) Govaerts (Lamiaceae) was performed for the first time. It allowed the isolation and characterization of the essential oil and six known compounds: carvacrol (1), squalane (2), uvaol (3), erythrodiol (4), ursolic acid (5), and salvigenin (6). Their structures were identified and characterized by Nuclear Magnetic Resonance (NMR) and Gas Chromatography coupled to Mass Spectroscopy (GC-MS), and corroborated by literature...
January 11, 2018: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/29324385/ameliorative-effects-of-selenium-on-arsenic-induced-cytotoxicity-in-pc12%C3%A2-cells-via-modulating-autophagy-apoptosis
#12
Md Mostafizur Rahman, Rachael A Uson-Lopez, Md Tajuddin Sikder, Gongxun Tan, Toshiyuki Hosokawa, Takeshi Saito, Masaaki Kurasaki
Arsenic is well known toxicant responsible for human diseases including cancers. On the other hand, selenium is an essential trace element with significant chemopreventive effects, anticancer potentials and antioxidant properties. Although previous studies have reported antagonism/synergism between arsenic and selenium in biological systems, the biomolecular mechanism/s is still inconclusive. Therefore, to elucidate the molecular phenomena in cellular level, we hypothesized that co-exposure of selenium with arsenic may have suppressive effects on arsenic-induced cytotoxicity...
December 28, 2017: Chemosphere
https://www.readbyqxmd.com/read/29323424/in-vitro-and-in-vivo-effects-of-ophthalmic-solutions-on-silicone-hydrogel-bandage-lens-material-senofilcon-a
#13
Nejla B Erdal, Karin H Adolfsson, Sara De Lima, Minna Hakkarainen
BACKGROUND: Acuvue Oasys silicone hydrogel contact lenses (Senofilcon A) are used as bandage lenses and often combined with ophthalmic solutions in the treatment of ocular diseases. Concerns have been raised regarding the compatibility and effect of eye-drop solutions on the bandage lenses, which have led to frequent replacement of lenses causing clinical problems. Some patients experience pain or discomfort during treatments and the accumulation of drugs and preservatives in lenses has been suggested as a possible reason...
January 11, 2018: Clinical & Experimental Optometry: Journal of the Australian Optometrical Association
https://www.readbyqxmd.com/read/29320716/distinct-roles-of-systemic-and-local-actions-of-insulin-on-pancreatic-%C3%AE-cells
#14
Takumi Kitamoto, Kenichi Sakurai, Eun Young Lee, Koutaro Yokote, Domenico Accili, Takashi Miki
OBJECTIVE: Pancreatic β-cell mass and function are critical in glucose homeostasis. Their regulatory mechanisms have been studied principally under experimental conditions of reduced β-cell numbers, such as β-cell ablation and partial pancreatectomy. In the present study, we generated an opposite mouse model with an excessive amount of ectopic β-cells, and analyzed its consequence on β-cell mass and survival. METHODS: Mice underwent sub-renal transplantation (SRT) of pseudo-islets generated from a pancreatic β-cell line MIN6 or intra-pancreatic transplantation (IPT) of MIN6 cells, and morphological and functional changes of their endocrine pancreata were analyzed...
January 7, 2018: Metabolism: Clinical and Experimental
https://www.readbyqxmd.com/read/29320168/linking-natural-oil-seeps-from-the-gulf-of-mexico-to-their-origin-by-use-of-fourier-transform-ion-cyclotron-resonance-mass-spectrometry
#15
Logan C Krajewski, Vladislav V Lobodin, Caroline Johansen, Tessa E Bartges, Ekaterina V Maksimova, Ian R MacDonald, Alan G Marshall
We report chemical characterization of natural oil seeps from the Gulf of Mexico by Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) and Gas Chromatography/Atmospheric Pressure Chemical Ionization Mass Spectrometry (GC/APCI-MS), to highlight how FT-ICR MS can also be employed as a means to determine petroleum connectivity, in addition to traditional GC/MS techniques. The source of petroleum is the Green Canyon (GC) 600 lease block in the Gulf of Mexico. Within GC600, two natural oil seepage zones, Mega Plume and Birthday Candles, continuously release hydrocarbons and develop persistent oil slicks at the sea surface above them...
January 10, 2018: Environmental Science & Technology
https://www.readbyqxmd.com/read/29316158/reduced-stroke-distance-of-the-left-ventricular-outflow-tract-is-independently-associated-with-long-term-mortality-in%C3%A2-patients-hospitalized-due-to-heart-failure
#16
You Zhong, Qays Almodares, JieFu Yang, Fang Wang, Michael Fu, Magnus C Johansson
PURPOSE: Reduced blood circulation is an important feature of heart failure, and Doppler stroke distance of the left ventricular outflow tract is a measure of forward stroke volume. Several echocardiographic parameters have known prognostic implications in heart failure, but the prognostic implications of stroke distance in relation to other parameters are insufficiently known. The aim was therefore to test the hypothesis that stroke distance is associated with five-year all-cause mortality, independently of other echocardiography variables, and that stroke distance has added long-term prognostic value...
January 9, 2018: Clinical Physiology and Functional Imaging
https://www.readbyqxmd.com/read/29315909/seeking-excellence-an-evaluation-of-235-international-laboratories-conducting-water-isotope-analyses-by-isotope-ratio-and-laser-absorption-spectrometer
#17
L I Wassenaar, S Terzer-Wassmuth, C Douence, L Araguas-Araguas, P K Aggarwal, T B Coplen
RATIONALE: Water stable isotope ratios (δ2 H and δ18 O values) are widely used tracers in environmental studies; hence, accurate and precise assays are required for providing sound scientific information. We tested the analytical performance of 235 international laboratories conducting water isotope analyses using dual-inlet and continuous-flow isotope ratio mass spectrometers and laser spectrometers through a water isotope inter-comparison test. METHODS: Eight test water samples were distributed by the IAEA to international stable isotope laboratories...
January 5, 2018: Rapid Communications in Mass Spectrometry: RCM
https://www.readbyqxmd.com/read/29313750/serum-retinol-folic-acid-and-copper-are-associated-with-sperm-abnormalities-in-men-with-obesity
#18
Berniza Calderón, Vital Hevia, Belén Vega-Piñero, Antonia Martín-Hidalgo, Helena Mendez-Del Sol, Héctor F Escobar-Morreale, José I Botella-Carretero
BACKGROUND AND OBJECTIVES: Micronutrients may influence the development and differentiation of sperm cells. The aim of this study was to assess the possible association of deficiencies in several vitamins and trace elements with sperm abnormalities in men with obesity. PARTICIPANTS AND METHODS: Thirty male patients with moderate to severe obesity and ten lean controls who gave written informed consent were included. Anthropometric parameters were recorded. Hormonal and lipid profiles were analyzed, as well as serum concentrations of zinc, copper, retinol, α-tocopherol, 25-hydroxyvitamin D, cobalamin, and folic acid...
January 9, 2018: Journal of the American College of Nutrition
https://www.readbyqxmd.com/read/29313173/dietary-deoxynivalenol-does-not-affect-mineral-element-accumulation-in-breast-and-thigh-muscles-of-broiler-chicken
#19
Manfred Sager, Annegret Lucke, Khaled Ghareeb, Manoochehr Allymehr, Qendrim Zebeli, Josef Böhm
Deoxynivalenol (DON), a well-known contaminant of feed, can have negative effects on gut permeability and function in poultry, which then could affect major and trace element content of the broilers' breast and thigh muscles, and ultimately reduce meat quality. To study this hypothesis, DON-contaminated diet was fed to broiler chicks. Two groups of birds were housed in metabolic cages with free access to water and feed, with or without DON (10 mg/kg). After 5 weeks, birds were dissected and samples of the breast and thigh muscles, feed and droppings were analysed for five macro (Ca, K, Mg, Na, and P) and ten micro elements (Al, Cr, Cu, Fe, Mn, Li, Mo, Ni, Pb, Rb, and Zn) by inductively coupled plasma optical emission spectrometry (ICP-OES) or inductively coupled plasma mass spectrometer (ICP-MS) methods...
January 8, 2018: Mycotoxin Research
https://www.readbyqxmd.com/read/29310695/understanding-the-relationship-between-egg-and-antigen-based-diagnostics-of-schistosoma-mansoni-infection-pre-and-post-treatment-in-uganda
#20
Joaquín M Prada, Panayiota Touloupou, Moses Adriko, Edridah M Tukahebwa, Poppy H L Lamberton, T Déirdre Hollingsworth
BACKGROUND: Schistosomiasis is a major socio-economic and public health problem in many sub-Saharan African countries. After large mass drug administration (MDA) campaigns, prevalence of infection rapidly returns to pre-treatment levels. The traditional egg-based diagnostic for schistosome infections, Kato-Katz, is being substituted in many settings by circulating antigen recognition-based diagnostics, usually the point-of-care circulating cathodic antigen test (CCA). The relationship between these diagnostics is poorly understood, particularly after treatment in both drug-efficacy studies and routine monitoring...
January 8, 2018: Parasites & Vectors
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