Read by QxMD icon Read

Secondary ion mass spectrometry

Kiyoshi Minoura, Miho Yamada, Takashi Mizoguchi, Toshihiro Kaneko, Kyoko Nishiyama, Mari Ozminskyj, Tetsuo Koshizuka, Ikuo Wada, Tatsuo Suzutani
The antibacterial effect of a nanostructured film, known as "moth-eye film," was investigated. The moth-eye film has artificially formed nano-pillars, consisting of hydrophilic resin with urethane acrylate and polyethylene glycol (PEG) derivatives, all over its surface that replicates a moth's eye. Experiments were performed to compare the moth-eye film with a flat-surfaced film produced from the same materials. The JIS Z2801 film-covering method revealed that the two films produced a decrease in Staphylococcus aureus and Esherichia coli titers of over 5 and 3 logs, respectively...
2017: PloS One
Di Huang, Xin Hua, Guang-Li Xiu, Yong-Jie Zheng, Xiao-Ying Yu, Yi-Tao Long
Currently, considerable attention has been paid to atmospheric particulate matter (PM) investigation due to its importance in human health and global climate change. Surface characterization, single particle analysis and depth profiling of PM is important for a better understanding of its formation processes and predicting its impact on the environment and human being. Secondary ion mass spectrometry (SIMS) is a surface technique with high surface sensitivity, high spatial resolution chemical imaging and unique depth profiling capabilities...
October 9, 2017: Analytica Chimica Acta
Jozef Lengyel, Jakub Med, Petr Slavíček, Martin K Beyer
The reaction of HNO3 with hydrated electrons (H2O)n(-) (n = 35-65) in the gas phase was studied using Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometry and ab initio molecular dynamics simulations. Kinetic analysis of the experimental data shows that OH(-)(H2O)m is formed primarily via a reaction of the hydrated electron with HNO3 inside the cluster, while proton transfer is not observed and NO3(-)(H2O)m is just a secondary product. The reaction enthalpy was determined using nanocalorimetry, revealing a quite exothermic charge transfer with -241 ± 69 kJ mol(-1)...
September 14, 2017: Journal of Chemical Physics
Ronald F S Lee, Tina Riedel, Stéphane Escrig, Catherine Maclachlan, Graham W Knott, Curt A Davey, Kai Johnsson, Anders Meibom, Paul J Dyson
Cisplatin is a widely used anti-cancer drug, but its effect is often limited by acquired resistance to the compound during treatment. Here, we use a combination of transmission electron microscopy (TEM) and nanoscale-secondary ion mass spectrometry (NanoSIMS) to reveal differences between cisplatin uptake in human ovarian cancers cells, which are known to be susceptible to acquired resistance to cisplatin. Both cisplatin sensitive and resistant cell lines were studied, revealing markedly less cisplatin in the resistant cell line...
September 15, 2017: Metallomics: Integrated Biometal Science
Holger Sieg, Claudia Kästner, Benjamin Christoph Krause, Thomas Meyer, Agnes Burel, Linda Böhmert, Dajana Lichtenstein, Harald Jungnickel, Jutta Tentschert, Peter Laux, Albert Braeuning, Irina Estrela-Lopis, Fabienne Gauffre, Valerie Fessard, Jan Meijer, Andreas Luch, Andreas F Thünemann, Alfonso Lampen
Aluminum has gathered toxicological attention based on relevant human exposure and its suspected hazardous potential. Nanoparticles from food supplements or food contact materials may reach the human gastrointestinal tract. Here, we monitored the physico-chemical fate of aluminum-containing nanoparticles and aluminum ions when passaging an in vitro model of the human gastrointestinal tract. Small-angle X-ray scattering (SAXS), transmission electron microscopy (TEM), ion beam microscopy (IBM), secondary ion beam mass spectrometry (TOF-SIMS), and inductively coupled plasma mass spectrometry (ICP-MS) in the single-particle mode were employed to characterize two aluminum-containing nanomaterials with different particle core materials (Al0, γAl2O3) and soluble AlCl3...
September 13, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
Florian Vollnhals, Jean-Nicolas Audinot, Tom Wirtz, Muriel Mercier-Bonin, Isabelle Fourquaux, Birgit Schroeppel, Udo Kraushaar, Varda Lev-Ram, Mark H Ellisman, Santhana Eswara
Correlative microscopy combining various imaging modalities offers powerful insights to obtain a comprehensive understanding of physical, chemical and biological phenomena. In this article, we investigate two approaches for image-fusion in the context of combining the inherently lower-resolution chemical images obtained using Secondary Ion Mass Spectrometry (SIMS) with the high-resolution ultrastructural images obtained using Electron Microscopy (EM). We evaluate the image fusion methods with three different case-studies selected to broadly represent the typical samples in life science research: (i) histology (unlabeled tissue), (ii) nanotoxicology, and (iii) metabolism (isotopically labelled tissue)...
September 13, 2017: Analytical Chemistry
Yu I Kostyukevich, A S Kononikhin, M I Indeykina, I A Popov, K V Bocharov, A I Spassky, S A Kozin, A A Makarov, E N Nikolaev
Complexes of peptide fragment 1-16 of beta-amyloid with transition metals play an important role in the development of a broad class of neurodegenerative diseases, which determines the interest in investigating the structures of these complexes. In this work, we have applied the method of the deuterium/hydrogen exchange in combination with ultra-high-resolution mass spectrometry to study conformational changes in (1-16) beta-amyloid peptide induced by binding of zinc(II) atoms. The efficiency of the deuterium/hydrogen exchange depended on the number of zinc atoms bound to the peptide and on the temperature of the ionization source region...
July 2017: Molekuliarnaia Biologiia
Vytis Čižinauskas, Nicolas Elie, Alain Brunelle, Vitalis Briedis
Natural oils are commonly used in topical pharmaceutical formulations as emulsifiers, stabilizers or solubility enhancers. They are presented as safe and inert components, mainly used for formulation purposes. It is confirmed that natural oils can affect the skin penetration of various substances. Fatty acids are mainly responsible for this effect. Current understanding lacks reliable scientific data on penetration of natural oils into the skin and their skin penetration enhancement potential. In the current study, fatty acid content analysis was used to determine the principal fatty acids in soybean, olive, avocado, sea-buckthorn pulp, raspberry seed and coconut oils...
September 12, 2017: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
A V Steele, A Schwarzkopf, J J McClelland, B Knuffman
We present measurements of focal spot size and brightness in a focused ion beam system utilizing a laser-cooled atomic beam source of Cs ions. Spot sizes as small as (2.1 ± 0.2) nm (one standard deviation) and reduced brightness values as high as (2.4 ± 0.1) × 10(7) A m(-2) Sr(-1) eV(-1) are observed with a 10 keV beam. This measured brightness is over 24 times higher than the highest brightness observed in a Ga liquid metal ion source. The behavior of brightness as a function of beam current and the dependence of effective source temperature on ionization energy are examined...
June 2017: Nano Futures
Emeline Hanozin, Benoit Mignolet, Denis Morsa, Damien Sluysmans, Anne-Sophie Duwez, J Fraser Stoddart, Françoise Remacle, Edwin De Pauw
At the interface between foldamers and mechanically interlocked molecules, oligorotaxanes exhibit a spring-like folded secondary structure with remarkable mechanical and physicochemical properties. Among these properties, the ability of oligorotaxanes to act as molecular switches through controlled modulations of their spatial extension over (un)folding dynamics is of particular interest. The present study aims to assess and further characterize this remarkable feature in the gas phase using mass spectrometry tools...
September 13, 2017: ACS Nano
Rachel Komorek, Wenchao Wei, Xiaofei Yu, Eric Hill, Juan Yao, Zihua Zhu, Xiao-Ying Yu
Bacterial biofilms are surface-associated communities that are vastly studied to understand their self-produced extracellular polymeric substances (EPS) and their roles in environmental microbiology. This study outlines a method to cultivate biofilm attachment to the System for Analysis at the Liquid Vacuum Interface (SALVI) and achieve in situ chemical mapping of a living biofilm by time-of-flight secondary ion mass spectrometry (ToF-SIMS). This is done through the culturing of bacteria both outside and within the SALVI channel with our specialized setup, as well as through optical imaging techniques to detect the biofilm presence and thickness before ToF-SIMS analysis...
August 18, 2017: Journal of Visualized Experiments: JoVE
Robert M T Madiona, Nicholas G Welch, Judith A Scoble, Benjamin W Muir, Paul J Pigram
Determination of a limit of detection (LoD) for surface bound antibodies is crucial for the development and deployment of sensitive bioassays. The measurement of very low concentrations of surface bound antibodies is also important in the manufacturing of pharmaceutical products such as antibody-conjugated pharmaceuticals. Low concentrations are required to avoid an immune response from the target host. Enzyme-linked immunosorbent assay (ELISA), x-ray photoelectron spectroscopy (XPS), and time-of-flight secondary ion mass spectrometry (ToF-SIMS) were used to determine the LoD for the surface bound antibody (antiepidermal growth factor receptor antibody) on silicon substrates...
August 11, 2017: Biointerphases
Satoka Aoyagi, Kiyoshi Abe, Takayuki Yamagishi, Hideo Iwai, Satoru Yamaguchi, Takashi Sunohara
Blood adsorption onto the inside surface of hollow fiber dialysis membranes was investigated by means of time-of-flight secondary ion mass spectrometry (TOF-SIMS) and near-field infrared microscopy (NFIR) in order to evaluate the biocompatibility and permeability of dialysis membranes. TOF-SIMS is useful for the imaging of particular molecules with a high spatial resolution of approximately 100 nm. In contrast, infrared spectra provide quantitative information and NFIR enables analysis with a high spatial resolution of less than 1 μm, which is close to the resolution of TOF-SIMS...
August 25, 2017: Analytical and Bioanalytical Chemistry
M A Reshchikov, A Usikov, H Helava, Yu Makarov, V Prozheeva, I Makkonen, F Tuomisto, J H Leach, K Udwary
Photoluminescence (PL) was used to estimate the concentration of point defects in GaN. The results are compared with data from positron annihilation spectroscopy (PAS), secondary ion mass spectrometry (SIMS), and deep level transient spectroscopy (DLTS). Defect-related PL intensity in undoped GaN grown by hydride vapor phase epitaxy increases linearly with the concentration of related defects only up to 10(16) cm(-3). At higher concentrations, the PL intensity associated with individual defects tends to saturate, and accordingly, does not directly correlate with the concentration of defects...
August 24, 2017: Scientific Reports
Sébastien Cambier, Marthe Røgeberg, Anastasia Georgantzopoulou, Tommaso Serchi, Camilla Karlsson, Steven Verhaegen, Tore-Geir Iversen, Cédric Guignard, Marcin Kruszewski, Lucien Hoffmann, Jean-Nicolas Audinot, Erik Ropstad, Arno C Gutleb
The use of silver nanomaterials in everyday products, such as cosmetics, textiles, certain types of packaging, etc. is increasing, leading to their release into the environment, including aquatic ecosystems. This last point initiated this investigation on the toxicological effects of Ag nanoparticles (Ag NPs) in the aquatic model organism Danio rerio. For this purpose, zebrafish larvae were exposed to 20nm bare Ag NPs at different concentrations and AgNO3, used as a positive control for Ag(+) ions toxicity, at the beginning of their foraging behaviour to determine adverse effects on fitness parameters...
August 20, 2017: Science of the Total Environment
Satvika Burugupalli, Mark B Richardson, Spencer J Williams
We report the total synthesis of (R)-tuberculostearic acid-containing Mycobacterium tuberculosis phosphatidylglycerol (PG). The approach features a two-step synthesis of (R)-tuberculostearic acid, involving an (S)-citronellyl bromide linchpin, and the phosphoramidite-assisted assembly of the full PG structure. Collision-induced dissociation mass spectrometry of two chemically-synthesized PG acyl regioisomers revealed diagnostic product ions formed by preferential loss of carboxylate at the secondary (sn-2) position...
September 13, 2017: Organic & Biomolecular Chemistry
DanDan Yan, Yong Foo Wong, Laura Tedone, Robert A Shellie, Philip J Marriott, Simon P Whittock, Anthony Koutoulis
Comprehensive two-dimensional gas chromatography with quadrupole accurate mass time-of-flight mass spectrometry (GC×GC-Q-TOFMS) is employed to profile Humulus lupulus L. (hop) essential oils. Comparison of characterised essential oils allows discrimination among chemotypes. Experimental and commercial hop genotypes displayed distinguishable chemotypic patterns among the volatile secondary metabolites making up their essential oils. In total, 210-306 unique compounds were detected (depending on specific genotype), with 99 of these compounds either positively or tentatively identified...
August 9, 2017: Journal of Chromatography. A
Kyle D Duncan, Hilde-Marléne Bergman, Ingela Lanekoff
Nanospray desorption electrospray ionization (nano-DESI) has been established as a powerful technique for mass spectrometry imaging (MSI) of biomolecules from tissue samples. The direct liquid extraction of analytes from a surface at ambient pressure negates the need for significant sample preparation or matrix application. Although many recent studies have applied nano-DESI to new and exciting applications, there has not been much work in the development and improvement of the nano-DESI source. Here, we incorporate a nebulizer to replace the self-aspirating secondary capillary in the conventional nano-DESI setup, and characterize the device by use of rat kidney tissue sections...
August 22, 2017: Analyst
Hui-Ting Cao, Hua-Xu Zhu, Qi-Chun Zhang, Li-Wei Guo
The metabolic effect of Huanglian-Huangqin herb pairs on cerebral ischemia rats was studied by using metabolomic method. The rat model of ischemia reperfusion injury induced by introduction of transient middle cerebral artery occlusion (MCAO) followed by reperfusion. Ultra high performance liquid chromatography-series four pole time of flight mass spectrometry method(UPLC-Q-TOF/MS), Markerlynx software, and principal component analysis and partial least-squares discriminant analysis were used to analyze the different endogenous metabolites among the urine samples of sham rats, cerebral ischemia model rats, Huanglian groups (HL), Huangqin groups (HQ) and Huanglian-Huangqin herb pairs groups (LQ) was achieved, combined with accurate information about the endogenous metabolites level and secondary fragment ions, retrieval and identification of possible biological markers, metabolic pathway which build in MetPA database...
June 2017: Zhongguo Zhong Yao za Zhi, Zhongguo Zhongyao Zazhi, China Journal of Chinese Materia Medica
Wenchao Wei, Yanyan Zhang, Rachel Komorek, Andrew Plymale, Rujia Yu, Bingchen Wang, Zihua Zhu, Fanghua Liu, Xiao-Ying Yu
The aggregation of syntrophic Geobacter metallireducens and Geobacter sulfurreducens is beneficial for enhancing direct interspecies electron transfer (DIET). Although DIET was suspected to occur on the microbial community surface, the surface chemical speciation of such cocultured communities remains unclear. In order to better understand surface interactions related to DIET, the authors characterized a series of samples associated with syntrophic G. metallireducens and G. sulfurreducens using surface sensitive time-of-flight secondary ion mass spectrometry (ToF-SIMS)...
August 18, 2017: Biointerphases
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"