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Secondary ion mass spectrometry

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https://www.readbyqxmd.com/read/28810732/tracking-radionuclide-fractionation-in-the-first-atomic-explosion-using-stable-elements
#1
Chloe E Bonamici, Richard L Hervig, William S Kinman
Compositional analysis of post-detonation fallout is a tool for forensic identification of nuclear devices. However, the relationship between device composition and fallout composition is difficult to interpret because of the complex combination of physical mixing, nuclear reactions, and chemical fractionations that occur in the chaotic nuclear fireball. Using a combination of in situ microanalytical techniques - electron microprobe analysis and secondary ion mass spectrometry - we show that some heavy stable elements (Rb, Sr, Zr, Ba, Cs, Ba, La, Ce, Nd, Sm, Dy, Lu, U, Th) in glassy fallout from the first nuclear test, Trinity, are reliable chemical proxies for radionuclides generated during the explosion...
August 16, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28808741/stable-isotope-raman-microspectroscopy-for-the-analysis-of-soil-organic-matter
#2
Alexandra C Wiesheu, Ramona Brejcha, Carsten W Mueller, Ingrid Kögel-Knabner, Martin Elsner, Reinhard Niessner, Natalia P Ivleva
We examined the potential of stable-isotope Raman microspectroscopy (SIRM) for the evaluation of differently enriched (13)C-labeled humic acids as model substances for soil organic matter (SOM). The SOM itself can be linked to the soil water holding capacity. Therefore, artificial humic acids (HA) with known isotopic compositions were synthesized and analyzed by means of SIRM. By performing a pregraphitization, a suitable analysis method was developed to cope with the high fluorescence background. Results were verified against isotope ratio mass spectrometry (IRMS)...
August 14, 2017: Analytical and Bioanalytical Chemistry
https://www.readbyqxmd.com/read/28800703/mechanism-of-the-reduction-in-the-igg-and-ige-binding-of-%C3%AE-lactoglobulin-induced-by-ultrasound-pretreatment-combined-with-dry-state-glycation-a-study-using-conventional-spectrometry-and-high-resolution-mass-spectrometry
#3
Wenhua Yang, Zongcai Tu, Hui Wang, Lu Zhang, Shengsheng Xu, Chendi Niu, Honglin Yao, Igor A Kaltashov
Bovine β-lactoglobulin (β-Lg) is one of major allergens in cow's milk. Previous study showed that ultrasound treatment induced the conformational changes of β-Lg and promoted the glycation in aqueous solutions, which is, however, less efficient compared with dry-state. In this work, the effect of ultrasound pretreatment combined with dry-state glycation on the IgG and IgE binding of β-Lg was studied. Dry-state glycation with mannose after ultrasound pretreatment at 0-600 W significantly reduced the IgG and IgE binding of β-Lg, with the lowest values observed at 400 W...
August 11, 2017: Journal of Agricultural and Food Chemistry
https://www.readbyqxmd.com/read/28777977/relationship-between-reactive-oxygen-species-and-water-soluble-organic-compounds-time-resolved-benzene-carboxylic-acids-measurement-in-the-coastal-area-during-the-korus-aq-campaign
#4
Min-Suk Bae, James J Schauer, Taehyoung Lee, Ju-Hee Jeong, Yoo-Keun Kim, Chul-Un Ro, Sang-Keun Song, Zang-Ho Shon
This study investigated the relationship between water-soluble organic compounds of ambient particulate matter (PM) and cellular redox activity collected from May 28 to June 20 of 2016 at the west coastal site in the Republic of Korea during the KORea-US Air Quality (KORUS-AQ) campaign. Automatic four-hour integrated samples operated at a flow rate of 92 L per minute for the analysis of organic carbon (OC), water-soluble organic carbon (WSOC), elemental carbon (EC), water-soluble ions (WSIs), and benzene carboxylic acids (BCAs) were collected on a 47 mm quartz fiber filter...
August 1, 2017: Environmental Pollution
https://www.readbyqxmd.com/read/28777541/uv-curable-contact-active-benzophenone-terminated-quaternary-ammonium-antimicrobials-for-applications-in-polymer-plastics-and-related-devices
#5
Lukas Porosa, Alexander Caschera, Amanda Mocella, Joseph Bedard, Evan Ronan, Alan J Lough, Gideon Wolfaardt, Daniel Foucher
A series of UV active benzophenone ([C6H5COC6H4-O-(CH2)n-N+Me2R][X-], 4: R = C12H25, n = 3, X- = Br- , 5a-c: R = C18H37, n = 3, X- = Cl-, Br-, I-; 6a-c: R = C18H37, n = 4, X- = Cl-, Br-, I- ; 7a-c: R = C18H37, n = 6, X- = Cl-, Br-, I-) terminated C12 and C18 quaternary ammonium salts (QACs) were prepared by thermal or microwave driven Menshutkin protocols of the appropriate benzophenone alkyl halide (1a-c, 2a-c, 3a-c) with the corresponding dodecyl- or octadecyl N,N-dimethylamine. All new compounds were characterized by NMR spectroscopy, HRMS spectrometry and in one instance (4) by single crystal X-ray crystallography...
August 4, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28776072/tof-sims-and-principal-component-analysis-of-lipids-and-amino-acids-from-inflamed-and-dysplastic-human-colonic-mucosa
#6
Marco Urbini, Valentina Petito, Francesco de Notaristefani, Franco Scaldaferri, Antonio Gasbarrini, Luca Tortora
Here, time of flight secondary ion mass spectrometry (ToF-SIMS) and multivariate analysis were combined to study the role of ulcerative colitis (UC), a type of inflammatory bowel disease (IBD), in the colon cancer progression. ToF-SIMS was used to obtain mass spectra and chemical maps from the mucosal surface of human normal (NC), inflamed (IC), and dysplastic (DC) colon tissues. Chemical mapping with a lateral resolution of ≈ 1 μm allowed to evaluate zonation of fatty acids and amino acids as well as the morphological condition of the intestinal glands...
August 3, 2017: Analytical and Bioanalytical Chemistry
https://www.readbyqxmd.com/read/28773978/roles-of-bulk-and-surface-chemistry-in-the-oxygen-exchange-kinetics-and-related-properties-of-mixed-conducting-perovskite-oxide-electrodes
#7
REVIEW
Nicola H Perry, Tatsumi Ishihara
Mixed conducting perovskite oxides and related structures serving as electrodes for electrochemical oxygen incorporation and evolution in solid oxide fuel and electrolysis cells, respectively, play a significant role in determining the cell efficiency and lifetime. Desired improvements in catalytic activity for rapid surface oxygen exchange, fast bulk transport (electronic and ionic), and thermo-chemo-mechanical stability of oxygen electrodes will require increased understanding of the impact of both bulk and surface chemistry on these properties...
October 21, 2016: Materials
https://www.readbyqxmd.com/read/28773172/ion-beam-induced-atomic-mixing-in-ge-si-and-sige-studied-by-means-of-isotope-multilayer-structures
#8
Manuel Radek, Bartosz Liedke, Bernd Schmidt, Matthias Voelskow, Lothar Bischoff, John Lundsgaard Hansen, Arne Nylandsted Larsen, Dominique Bougeard, Roman Böttger, Slawomir Prucnal, Matthias Posselt, Hartmut Bracht
Crystalline and preamorphized isotope multilayers are utilized to investigate the dependence of ion beam mixing in silicon (Si), germanium (Ge), and silicon germanium (SiGe) on the atomic structure of the sample, temperature, ion flux, and electrical doping by the implanted ions. The magnitude of mixing is determined by secondary ion mass spectrometry. Rutherford backscattering spectrometry in channeling geometry, Raman spectroscopy, and transmission electron microscopy provide information about the structural state after ion irradiation...
July 17, 2017: Materials
https://www.readbyqxmd.com/read/28772843/enhanced-ferromagnetism-in-nanoscale-gan-mn-wires-grown-on-gan-ridges
#9
Ji Cheng, Shengxiang Jiang, Yan Zhang, Zhijian Yang, Cunda Wang, Tongjun Yu, Guoyi Zhang
The problem of weak magnetism has hindered the application of magnetic semiconductors since their invention, and on the other hand, the magnetic mechanism of GaN-based magnetic semiconductors has been the focus of long-standing debate. In this work, nanoscale GaN:Mn wires were grown on the top of GaN ridges by metalorganic chemical vapor deposition (MOCVD), and the superconducting quantum interference device (SQUID) magnetometer shows that its ferromagnetism is greatly enhanced. Secondary ion mass spectrometry (SIMS) and energy dispersive spectroscopy (EDS) reveal an obvious increase of Mn composition in the nanowire part, and transmission electron microscopy (TEM) and EDS mapping results further indicate the correlation between the abundant stacking faults (SFs) and high Mn doping...
May 2, 2017: Materials
https://www.readbyqxmd.com/read/28772757/failure-mechanisms-of-the-coating-metal-interface-in-waterborne-coatings-the-effect-of-bonding
#10
Hongxia Wan, Dongdong Song, Xiaogang Li, Dawei Zhang, Jin Gao, Cuiwei Du
Waterborne coating is the most popular type of coating, and improving its performance is a key point of research. Cathodic delamination is one of the major modes of failure for organic coatings. It refers to the weakening or loss of adhesion between the coating and substrate. Physical and chemical characteristics of coatings have been studied via scanning electron microscopy (SEM), atomic force microscopy (AFM), contact angle measurements, Fourier transform infrared spectroscopy (FTIR), and secondary ion mass spectrometry (SIMS)...
April 9, 2017: Materials
https://www.readbyqxmd.com/read/28771310/janus-monolayer-transition-metal-dichalcogenides
#11
Jing Zhang, Shuai Jia, Iskandar Kholmanov, Liang Dong, Dequan Er, Weibing Chen, Hua Guo, Zehua Jin, Vivek B Shenoy, Li Shi, Jun Lou
The crystal configuration of sandwiched S-Mo-Se structure (Janus SMoSe) at the monolayer limit has been synthesized and carefully characterized in this work. By controlled sulfurization of monolayer MoSe2, the top layer of selenium atoms is substituted by sulfur atoms, while the bottom selenium layer remains intact. The structure of this material is systematically investigated by Raman, photoluminescence, transmission electron microscopy, and X-ray photoelectron spectroscopy and confirmed by time-of-flight secondary ion mass spectrometry...
August 9, 2017: ACS Nano
https://www.readbyqxmd.com/read/28771307/co-registered-in-situ-secondary-electron-and-mass-spectral-imaging-on-the-helium-ion-microscope-demonstrated-using-lithium-titanate-and-magnesium-oxide-nanoparticles
#12
David Dowsett, Tom Wirtz
The development of a high resolution elemental imaging platform combining co-registered secondary ion mass spectrometry and high resolution secondary electron imaging is reported. The basic instrument setup and operation are discussed and in-situ image correlation is demonstrated on a lithium titanate and magnesium oxide nanoparticle mixture. The instrument uses both helium and neon ion beams generated by a gas field ion source to irradiate the sample. Both secondary electrons and secondary ions may be detected...
August 3, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28758661/interpenetration-of-ch3nh3pbi3-and-tio2-improves-perovskite-solar-cells-while-tio2-expansion-leads-to-degradation
#13
W C Lin, A Kovalsky, Y C Wang, L L Wang, S Goldberg, W L Kao, C Y Wu, H Y Chang, J J Shyue, C Burda
Perovskite solar cells have drawn much attention and achieved efficiencies over 22%, but relatively little is known about the long-term stability under photovoltaic operation. So far, stability studies have reported about the importance of degradation of each layer, but little to no consideration has been given to the whole device architecture. We investigated the stability of perovskite solar cells in order to fundamentally understand the mechanism behind efficiency improvement/degradation during device operation...
August 16, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28758368/composition-and-structure-of-porcine-digital-flexor-tendon-bone-insertion-tissues
#14
Sandhya Chandrasekaran, Mark Pankow, Kara Peters, Hsiao-Ying Shadow Huang
Tendon-bone insertion is a functionally graded tissue, transitioning from 200MPa tensile modulus at the tendon end to 20GPa tensile modulus at the bone, across just a few hundred micrometers. In this study, we examine the porcine digital flexor tendon insertion tissue to provide a quantitative description of its collagen orientation and mineral concentration by using Fast Fourier Transform (FFT) based image analysis and mass spectrometry, respectively. Histological results revealed uniformity in global collagen orientation at all depths, indicative of mechanical anisotropy, although at mid-depth, the highest fiber density, least amount of dispersion, and least cellular circularity were evident...
July 31, 2017: Journal of Biomedical Materials Research. Part A
https://www.readbyqxmd.com/read/28757358/strontium-release-from-sr-2-loaded-bone-cements-and-dispersion-in-healthy-and-osteoporotic-rat-bone
#15
Marcus Rohnke, Stefanie Pfitzenreuter, Boris Mogwitz, Anja Henß, Jürgen Thomas, Dina Bieberstein, Thomas Gemming, Svenja K Otto, Seemun Ray, Matthias Schumacher, Michael Gelinsky, Volker Alt
Drug functionalization of biomaterials is a modern and popular approach in biomaterials research. Amongst others this concept is used for the functionalization of bone implants to locally stimulate the bone healing process. For example strontium ions (Sr(2+)) are administered in osteoporosis therapy to stimulate bone growth and have recently been integrated into bone cements. Based on results of different analytical experiments we developed a two-phase model for the transport of therapeutically active Sr(2+)-ions in bone in combination with Korsmeyer-Peppas kinetics for the Sr(2+) release from bone cement...
July 27, 2017: Journal of Controlled Release: Official Journal of the Controlled Release Society
https://www.readbyqxmd.com/read/28756320/surface-tailoring-of-polyacrylate-grafted-graphene-oxide-for-controlled-interactions-at-the-biointerface
#16
Giuseppe Consiglio, Patrizia Di Pietro, Luisa D'Urso, Giuseppe Forte, Giuseppe Grasso, Carmelo Sgarlata, Damien Cossement, Rony Snyders, Cristina Satriano
The actual surface termination and lateral size of a nanomaterial is crucial in its interaction with biomolecules at the aqueous interface. Graphene oxide (GO) nanosheets have been demonstrated as promising nanoplatform for both diagnostic and therapeutic applications. To this respect, 'smart' GO nanocarriers have been obtained by the surface functionalisation with polymers sensitive, e.g., to pH, as the polyacrylate (PAA) case. In this work, hybrid GO/PAA samples prepared respectively at low (GOPAAthin) or high (GOPAAthick) monomer grafting ratio, were scrutinised both theoretically, by molecular dynamic calculations, and experimentally by a multitechnique approach, including spectroscopic (UV-visible, fluorescence, Raman, Attenuated-total reflectance-Fourier transformed infrared and X-ray photoelectron spectroscopies), spectrometric (time-of-flight secondary ion and electrospray ionisation mass spectrometries) and microscopic (atomic force and confocal microscopies) methods...
July 21, 2017: Journal of Colloid and Interface Science
https://www.readbyqxmd.com/read/28755479/identifying-exposition-to-low-oxygen-environment-in-human-macrophages-using-secondary-ion-mass-spectrometry-and-multivariate-analysis
#17
Magali Court, Jean-Paul Barnes, Arnaud Millet
RATIONALE: Macrophages are innate immune cells presenting a strong phenotypic plasticity and deeply involved in tissue homeostasis. Oxygen environmental tension is a physical parameter that could influence their polarizations. In this study we use ToF-SIMS to describe how various polarizations are modified by a low oxygen exposure. METHODS: ToF-SIMS experiments were performed using an IONTOF ToF-SIMS 5-100 (ION-TOF GmbH, Munster, Germany). Analysis was performed using a pulsed 25 keV Bi(3+) beam, sputtering was performed using a 250 eV Cs beam...
July 29, 2017: Rapid Communications in Mass Spectrometry: RCM
https://www.readbyqxmd.com/read/28753276/sequencing-and-identification-of-endogenous-neuropeptides-with-matrix-enhanced-secondary-ion-mass-spectrometry-tandem-mass-spectrometry
#18
Nina Ogrinc Potočnik, Gregory L Fisher, Arnoud Prop, Ron M A Heeren
Matrix-enhanced secondary ion mass spectrometry (ME-SIMS) has overcome one of the biggest disadvantages of SIMS analysis by providing the ability to detect intact biomolecules at high spatial resolution. By increasing ionization efficiency and minimizing primary ion beam-induced fragmentation of analytes, ME-SIMS has proven useful for detection of numerous biorelevant species, now including peptides. We report here the first demonstration of tandem ME-SIMS for de novo sequencing of endogenous neuropeptides from tissue in situ (i...
August 3, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28752562/gas-phase-chemical-ionization-of-4-alkyl-branched-chain-carboxylic-acids-and-3-methylindole-using-h3-o-no-and-o2-ions
#19
Hardy Z Castada, Sheryl Barringer, Macdonald Wick
RATIONALE: 4-methyloctanoic acid, 4-ethyloctanoic acid, 4-methylnonanoic acid, and 3-methylindole are primary contributors to the distinctive aroma and flavor of lamb meat. The reactions of H3 O(+) , NO(+) , and O2(+) with these compounds, and identification of the product ions and their distribution, are fundamental to their characterization and rapid, real-time trace analysis using SIFT-MS. METHODS: The chemical ionization of pure standards of 4-ethyloctanoic acid, 4-methyloctanoic acid, 4-ethylnonanoic acid, and 3-methylindole was carried out using the H3 O(+) , NO(+) , and O2(+) reagent ions of a V200(TM) selected ion flow tube-mass spectrometer...
July 28, 2017: Rapid Communications in Mass Spectrometry: RCM
https://www.readbyqxmd.com/read/28744481/visualizing-antimicrobials-in-bacterial-biofilms-three-dimensional-biochemical-imaging-using-tof-sims
#20
Sarah K Davies, Sarah Fearn, Luke P Allsopp, Freya Harrison, Ecaterina Ware, Stephen P Diggle, Alain Filloux, David S McPhail, Jacob G Bundy
Bacterial biofilms are groups of bacteria that exist within a self-produced extracellular matrix, adhering to each other and usually to a surface. They grow on medical equipment and inserts such as catheters and are responsible for many persistent infections throughout the body, as they can have high resistance to many antimicrobials. Pseudomonas aeruginosa is an opportunistic pathogen that can cause both acute and chronic infections and is used as a model for research into biofilms. Direct biochemical methods of imaging of molecules in bacterial biofilms are of high value in gaining a better understanding of the fundamental biology of biofilms and biochemical gradients within them...
July 2017: MSphere
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