keyword
MENU ▼
Read by QxMD icon Read
search

#SoMe

keyword
https://www.readbyqxmd.com/read/28738660/novel-biomimetic-enzyme-for-sensitive-detection-of-superoxide-anions
#1
Fang Peng, Tingting Xu, Fan Wu, Chunxue Ma, Yuhong Liu, Jianying Li, Bo Zhao, Chun Mao
Superoxide anion (O2(•-)), one of the most active reactive oxygen species (ROS) in micro-environment of the human body, is involved in some diseases if there is excess O2(•-) associated with oxidative stress. Accurate detection of its concentration has important medical diagnostic significance. In this work, a new electrochemical sensor was designed and fabricated for sensitive detection based on Mn-superoxide dismutase (MnSOD) that decorated onto the surface of magnetic polymeric nanotubes by surface self-assembly processes...
November 1, 2017: Talanta
https://www.readbyqxmd.com/read/28738659/sample-treatment-in-m%C3%A3-ssbauer-spectroscopy-for-protein-related-analyses-nondestructive-possibilities-to-look-inside-metal-containing-biosystems
#2
Alexander A Kamnev, Anna V Tugarova
In this review, the unique possibilities are considered of the (57)Fe transmission (TMS) and (57)Co emission (EMS) variants of Mössbauer (nuclear γ-resonance) spectroscopy as nondestructive techniques with minimal sample preparation/treatment and a significant analytical potential, with a focus on the analysis of cation-binding sites in metalloproteins. The techniques are shown to provide unique structural and quantitative information on the coordination microenvironment, the chemical state and transformations of the Mössbauer nuclides in sophisticated metal-containing proteins, including those within complicated supramolecular structures, and in microbial cells or tissues...
November 1, 2017: Talanta
https://www.readbyqxmd.com/read/28738648/matrix-interference-evaluation-employing-gc-and-lc-coupled-to-triple-quadrupole-tandem-mass-spectrometry
#3
S Uclés, A Lozano, A Sosa, P Parrilla Vázquez, A Valverde, A R Fernández-Alba
Gas and liquid chromatography coupled to triple quadrupole tandem mass spectrometry are currently the most powerful tools employed for the routine analysis of pesticide residues in food control laboratories. However, whatever the multiresidue extraction method, there will be a residual matrix effect making it difficult to identify/quantify some specific compounds in certain cases. Two main effects stand out: (i) co-elution with isobaric matrix interferents, which can be a major drawback for unequivocal identification, and therefore false negative detections, and (ii) signal suppression/enhancement, commonly called the "matrix effect", which may cause serious problems including inaccurate quantitation, low analyte detectability and increased method uncertainty...
November 1, 2017: Talanta
https://www.readbyqxmd.com/read/28738638/mixed-matrix-membranes-incorporated-with-ln-mof-for-selective-and-sensitive-detection-of-nitrofuran-antibiotics-based-on-inner-filter-effect
#4
Feng Zhang, Hua Yao, Yifan Zhao, Xing Li, Gaowei Zhang, Yangyi Yang
The detection of antibiotics is critical and challenging due to the pervasive use of antibiotics had inevitably brought some negative impacts on ecosystem and human health. Herein, we reported an anti-interfere ability enhanced luminescent sensor of lanthanide metal-organic framework (Ln-MOF) filled mixed matrix membranes (MMMs), which combining the processibility of poly(methyl methacrylate) (PMMA) polymer with Ln-MOF of {[Tb2(AIP)2(H2O)10]·(AIP)·4H2O}n (Tb-AIP, where AIP is 5-aminoisophthalate) fillers...
November 1, 2017: Talanta
https://www.readbyqxmd.com/read/28738597/sensitive-detection-of-sulfide-based-on-the-self-assembly-of-fluorescent-silver-nanoclusters-on-the-surface-of-silica-nanospheres
#5
Yehan Yan, Kui Zhang, Huan Yu, Houjuan Zhu, Mingtai Sun, Tasawar Hayat, Ahmed Alsaedi, Suhua Wang
Hydrogen sulfide is a toxic and flammable gaseous pollutant often emitted to air as a by-product of water supply, chemical, petroleum and coal industries. It can be transferred into sulfur dioxide in the air under some meteorologic conditions. Herein, we report a novel ratiometric fluorescence method for hydrogen sulfide based on silver nanoclusters and quantum dots. The silver nanoclusters have been self-assemblied onto the surface of silica spheres, which are embedded with red fluorescent quantum dots, to form a dual-emissive nanohybrid...
November 1, 2017: Talanta
https://www.readbyqxmd.com/read/28738595/compound-specific-%C3%AE-13-c-and-%C3%AE-2-h-analysis-of-olive-oil-fatty-acids
#6
Mauro Paolini, Luana Bontempo, Federica Camin
Fatty acids are the most abundant biomolecules in olive oil. In this study, we describe the analytical method developed to measure the δ(13)C, and for the first time, the δ(2)H values of fatty acid methyl esters (FAMEs) extracted from olive oil triglycerides, after base-catalysed transesterification with methanol. The extracted FAMEs are analysed using Gas Chromatography Combustion/Pyrolysis Isotope Ratio Mass Spectrometry (GC-C/Py-IRMS). The method made it possible to obtain baseline separation between the peaks of the main FAMEs (C16, C18, C18:1, C18:2)...
November 1, 2017: Talanta
https://www.readbyqxmd.com/read/28738583/application-of-headspace-and-direct-immersion-solid-phase-microextraction-in-the-analysis-of-organothiophosphates-related-to-the-chemical-weapons-convention-from-water-and-complex-matrices
#7
Marc André Althoff, Andreas Bertsch, Manfred Metzulat, Thomas M Klapötke, Konstantin L Karaghiosoff
The successful application of headspace (HS) and direct immersion (DI) solid phase microextraction (SPME) for the unambiguous identification and characterization of a series of toxic thiophosphate esters, such as Amiton (I), from aqueous phases and complex matrices (e.g. grass and foliage) has been demonstrated. A Thermo Scientific gas chromatograph (GC) - tandem mass spectrometer (MS/MS) system with a TriPlus RSH® autosampler and a SPME tool was used to investigate the effect of different parameters that influence the extraction efficiency: e...
November 1, 2017: Talanta
https://www.readbyqxmd.com/read/28738578/a-simple-method-for-the-multi-elemental-analysis-of-beer-using-total-reflection-x-ray-fluorescence
#8
Ednilton M Gama, Clésia C Nascentes, Roberta P Matos, Gabrielle de C Rodrigues, Guilherme D Rodrigues
A method of direct analysis for quantification of 15 inorganic elements (P, S, Cl, K, Ca, Mn, Fe, Ni, Cu, Zn, Br, As, Rb, Sr and Pb) in beers by Total Reflection X-Ray Fluorescence (TXRF) was developed. The experimental conditions were optimized. Direct analysis was compared with the acid digestion procedure to evaluate the effect matrix and the results were satisfactory. The evaluation of the accuracy and precision was realized by analysis of two certified reference materials of natural and waste water. For the majority of the elements, good agreement was achieved between the certified value and the value measured in the CRM´s...
November 1, 2017: Talanta
https://www.readbyqxmd.com/read/28738563/urinary-volatile-fingerprint-based-on-mass-spectrometry-for-the-discrimination-of-patients-with-lung-cancer-and-controls
#9
Álvaro García Ramos, Ana Pérez Antón, Miguel Del Nogal Sánchez, José Luis Pérez Pavón, Bernardo Moreno Cordero
Profile signals of urine samples corresponding to patients with lung cancer and controls were obtained using a non-separative methodology. The method is based on the coupling of a headspace sampler, a programed temperature vaporizer and a mass spectrometer (HS-PTV-MS). With only a centrifugation step as prior sample treatment, the samples were subjected to the headspace generation process and the volatiles generated were introduced into the PTV where they were trapped in the Tenax® packed liner while the solvent was purged...
November 1, 2017: Talanta
https://www.readbyqxmd.com/read/28738558/elemental-source-attribution-signatures-for-calcium-ammonium-nitrate-can-fertilizers-used-in-homemade-explosives
#10
Carlos G Fraga, Alexander V Mitroshkov, Nikhil S Mirjankar, Brian P Dockendorff, Angie M Melville
Calcium ammonium nitrate (CAN) is a widely available fertilizer composed of ammonium nitrate (AN) mixed with some form of calcium carbonate such as limestone or dolomite. CAN is also frequently used to make homemade explosives. The potential of using elemental profiling and chemometrics to match both pristine and reprocessed CAN fertilizers to their factories of origin for use in future forensic investigations was examined. Inductively coupled plasma-mass spectrometry (ICP-MS) was used to determine the concentrations of 64 elements in 125 samples from 11 CAN stocks from 6 different CAN factories...
November 1, 2017: Talanta
https://www.readbyqxmd.com/read/28738544/a-xylanase-aided-enzymatic-pretreatment-facilitates-cellulose-nanofibrillation
#11
Lingfeng Long, Dong Tian, Jinguang Hu, Fei Wang, Jack Saddler
Although biological pretreatment of cellulosic fiber based on endoglucanases has shown some promise to facilitate cellulose nanofibrillation, its efficacy is still limited. In this study, a xylanase-aided endoglucanase pretreatment was assessed on the bleached hardwood and softwood Kraft pulps to facilitate the downstream cellulose nanofibrillation. Four commercial xylanase preparations were compared and the changes of major fiber physicochemical characteristics such as cellulose/hemicellulose content, gross fiber properties, fiber morphologies, cellulose accessibility/degree of polymerization (DP)/crystallinity were systematically evaluated before and after enzymatic pretreatment...
July 9, 2017: Bioresource Technology
https://www.readbyqxmd.com/read/28738514/unraveling-the-impact-of-nanoscale-zero-valent-iron-on-the-nitrogen-removal-performance-and-microbial-community-of-anammox-sludge
#12
Zheng-Zhe Zhang, Jia-Jia Xu, Zhi-Jian Shi, Yu-Hui Bai, Ya-Fei Cheng, Hai-Yan Hu, Ren-Cun Jin
Given the increasing use of nanoscale zero-valent iron (NZVI) particles for environmental remediation and wastewater treatment, their potential impact on anaerobic ammonium oxidation (anammox) bacteria was investigated in this study using anammox sludge. Batch assays showed that NZVI concentrations up to 200mgL(-1) did not affect anammox activity, reactive oxygen species production, and cell membrane integrity. The nitrogen removal efficiency of the continuous-flow reactor fluctuated in the presence of 20 or 50mgL(-1) NZVI, but it could return to normal over time, even at 200mgL(-1) NZVI...
July 11, 2017: Bioresource Technology
https://www.readbyqxmd.com/read/28738509/ambient-sediment-quality-conditions-in-minnesota-lakes-usa-effects-of-watershed-parameters-and-aquatic-health-implications
#13
Judy L Crane
Surficial sediments were collected from 50 randomly selected Minnesota lakes, plus four a priori reference lakes, in 2007. The lakes encompassed broad geographic coverage of the state and included a variety of major land uses in the surrounding watersheds. Sediment samples were analyzed for a suite of metals, metalloids, persistent organic pollutants, total organic carbon, and particle size fractions. In addition, a small fish survey was conducted to assess PBDEs in both whole fish and fish tissues. Sediment quality in this set of lakes ranged from good (43%) to moderate (57%) based on an integrative measure of multiple contaminants...
July 18, 2017: Science of the Total Environment
https://www.readbyqxmd.com/read/28738505/rethinking-aqueous-phase-diffusion-related-isotope-fractionation-contrasting-theoretical-effects-with-observations-at-the-field-scale
#14
Shu Xu, Barbara Sherwood Lollar, Brent E Sleep
Aqueous phase diffusion-related isotope fractionation (DRIF) was investigated through modelling to determine under what subsurface conditions carbon isotope DRIF effects would be observable using typical sampling approaches. A dispersive enrichment factor was defined based on heavy and light isotopologue dispersion coefficients. For a given ratio of source concentration (C0) to method detection limit (MDL), the maximum DRIF in a system increased linearly with transverse dispersive enrichment factor. Using this linear relationship, the critical dispersion enrichment factor for which DRIF would not be observable was quantified...
July 18, 2017: Science of the Total Environment
https://www.readbyqxmd.com/read/28738469/-analysis-on-geographic-distribution-of-high-blood-pressure-prevalence-in-children-and-adolescents-aged-7-18-years-in-china-2014
#15
Y H Dong, Z Y Zou, Z H Wang, S Wang, Z P Yang, Y J Chen, J Ma
Objective: To understand and evaluate the characteristics of geographic distribution of high blood pressure prevalence in children and adolescents aged 7-18 years in China in 2014, and provide evidence for the prevention of hypertension in children and adolescents. Methods: The data of 2014 Chinese National Surveys on Students Constitution and Health conducting 31 provinces (except Hong Kong, Macao and Taiwan) were collected. A total of 216 299 children and adolescents who had complete blood pressure records were selected as study subjects...
July 10, 2017: Zhonghua Liu Xing Bing Xue za Zhi, Zhonghua Liuxingbingxue Zazhi
https://www.readbyqxmd.com/read/28738458/-associations-between-season-of-birth-and-age-both-at-menarche-and-at-menopause
#16
J H Si, R R Meng, J Lyu, Y Guo, Z Bian, C Q Yu, L Yang, Y L Tan, P Pei, J S Chen, Z M Chen, L M Li
Objective: To examine the associations between season of birth and factors as age at menarche, age at menopause and reproductive span. Methods: A total of 285 186 female from the China Kadoorie Biobank, with complete data on critical variables and had menarche at 9-18 years old, were included. A total of 132 373 female with natural menopause were included for the analysis on age at menopause and reproductive span. Multiple linear regression models were used to assess the associations of birth season and the age at menarche, menopause, and reproductive span...
July 10, 2017: Zhonghua Liu Xing Bing Xue za Zhi, Zhonghua Liuxingbingxue Zazhi
https://www.readbyqxmd.com/read/28738450/the-effect-of-pressure-on-organic-reactions-in-fluids-a-new-theoretical-perspective
#17
REVIEW
Bo Chen, Roald Hoffmann, Roberto Cammi
This Review brings a new perspective to the study of chemical reactions in compressed fluid media. We begin by reviewing the substantial insight gained from more than 50 years of experimental studies on organic reactions in solution under pressure. These led to a proper estimation of the critical roles of volume of activation (Δ(≠) V) and reaction volume (ΔV) in understanding pressure effect on rates and equilibria of organic reactions. A recently developed computational method, the XP-PCM (extreme pressure polarizable continuum model) method, capable of carrying out quantum mechanical calculations of reaction pathways of molecules under pressure, is introduced...
July 24, 2017: Angewandte Chemie
https://www.readbyqxmd.com/read/28738410/no-large-population-of-unbound-or-wide-orbit-jupiter-mass-planets
#18
Przemek Mróz, Andrzej Udalski, Jan Skowron, Radosław Poleski, Szymon Kozłowski, Michał K Szymański, Igor Soszyński, Łukasz Wyrzykowski, Paweł Pietrukowicz, Krzysztof Ulaczyk, Dorota Skowron, Michał Pawlak
Planet formation theories predict that some planets may be ejected from their parent systems as result of dynamical interactions and other processes. Unbound planets can also be formed through gravitational collapse, in a way similar to that in which stars form. A handful of free-floating planetary-mass objects have been discovered by infrared surveys of young stellar clusters and star-forming regions as well as wide-field surveys, but these studies are incomplete for objects below five Jupiter masses. Gravitational microlensing is the only method capable of exploring the entire population of free-floating planets down to Mars-mass objects, because the microlensing signal does not depend on the brightness of the lensing object...
July 24, 2017: Nature
https://www.readbyqxmd.com/read/28738399/use-of-smartphones-for-clinical-and-medical-education
#19
Jazmine Valle, Tyler Godby, David P Paul, Harlan Smith, Alberto Coustasse
Smartphone use in clinical settings and in medical education has been on the rise, benefiting both health care and health care providers. Studies have shown, however, that some health care facilities and providers are reluctant to switch to smartphones due to the threat of mixing personal apps with clinical care applications and the possibility that distraction created by smartphone use could lead to medication errors and errors linked to procedures, treatments, or tests. The purpose of this research was to examine the effects of smartphones in a clinical setting and for medical education, to determine their overall impact...
July 2017: Health Care Manager
https://www.readbyqxmd.com/read/28738388/updated-friedman-staging-system-for-obstructive-sleep-apnea
#20
Michael Friedman, Anna M Salapatas, Lauren B Bonzelaar
In the practice of sleep medicine, the first step is identification of those patients at high risk for sleep apnea. Nearly every physician and every hospital has preferred methods of screening. Many patient questionnaires or surveys as well as some objective physical measurements have been suggested to predict the presence of sleep apnea. Screening is well established, and laboratory and home testing are widely available. An early assessment with a physical examination can help direct treatment planning. The Friedman tongue position, lingual tonsil hypertrophy grading, and the effects of oral positioning on the hypopharynx should be used in early assessment for treatment planning, and as screening tools to assess the sight of obstruction...
2017: Advances in Oto-rhino-laryngology
keyword
keyword
82681
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"