Rapid analysis of anabolic steroid metabolites in urine by combining field asymmetric waveform ion mobility spectrometry with liquid chromatography and mass spectrometry
The invention discloses a new interface with non-circular conductance limit aperture(s) useful for effective transmission of non-circular ion beams between stages with different gas pressure. In particular, the invention provides an improved coupling of field asymmetric waveform ion mobility spectrometry (FAIMS) analyzers of planar or side-to-side geometry to downstream stages such as mass spectrometry or ion mobility spectrometry. In this case, the non-circular aperture is rectangular; other geometries may be optimum in other applications. In the preferred embodiment, the non-circular aperture interface is followed by an electrodynamic ion funnel that may focus wide ion beams of any shape into tight circular beams with virtually no losses. The jet disrupter element of the funnel may also have a non-circular geometry, matching the shape of arriving ion beam. The improved sensitivity of planar FAIMS/MS has been demonstrated in experiments using a non-contiguous elongated aperture but other embodiments (e
... is a PhD student. Her project title is High Field Asymmetric Waveform Ion Mobility Spectrometry (FAIMS) and Mass Spectrometry for Proteomics. The project aims to develop FAIMS coupled to liquid chromatography tandem mass spectrometry with electron transfer dissociation (ETD) and collision induced dissociation (CID) for analysing complex proteomics samples with particular emphasis on post-translational modifications (PTMs), such as glycosylation.. One aspect of the project is to apply the LC-FAIMS-MS/MS approach to investigate glycosylation in Campylobacter jejuni (C. jejuni NCTC 11168). C. jejuni is the leading cause of gastroenteritis world-wide. The Fla A protein of C. jejuni has been found to be highly glycosylated and it has also been linked to the virulence of C. jejuni.. ...
This review summarizes the fundamental principle of ion mobility spectrometry (IMS). New progress is presented and commented in detail. Furthermore, the developmental trend of IMS is also discussed ...
An ion guide 24 for a mass spectrometer 30 including means for ejecting ions of different mass-to-charge ratios from the ion guide towards a detector or other object or device. The ejecting means causes the ions to be ejected in a desired sequence. The ions travel at different rates according to their mass-to-charge ratios, so that they arrive at a desired point in space in a desired sequence, for example in a detector 56 of a mass spectrometer at substantially the same time.
Ion molecule is a variety I transmembrane glycoprotein more than expressed in RB. Numerous epithelial cancers show up regulation of this protein and it has been
An ion guide includes a plurality of rods, arranged about an axis that extends lengthwise from one end to the other of the guide. The rods guide ions in a guide region along and about the axis. A con
We describe a novel conjoined ion guide that operates at intermediate pressure between API sources and the analyzer of a tandem quadrupole.
Learn how the timsTOF Pro solves difficult challenges in protein identification. Benefit from an extra Dimension of separation, peak capacity, sensitivity
The teaching of laboratories in the General Chemistry curriculum is an opportunity for educators to provide students with a 﫿avor of the practice of Chemistry. We present a guided inquiry and discovery oriented approach to presenting experiments in the General Chemistry laboratory. Our presentation requires students to design and implement an investigation in response to a scienti﫿c question. Students are provided with a guiding set of questions, leading them to design and implement an experimental investigation. Such an approach mirrors the process of scienti﫿c experimental design and research. We present a solubility product experiment within our paradigm of 﫿rst year chemistry experiments. The experiment involves discovery of the common ion effect from the experimental data and calculations. A work sheet with guiding questions is provided as a supporting document for easy integration into an existing curriculum. ...
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Watch this video to view real data generated on the SYNAPT G2-S HDMS. Triwave is the technology that provides ion mobility separations in the SYNAPT family of MS products from Waters. This provides an additional, orthogonal dimension of separation in a short timescale enabling scientists to increase analytical peak capacity with an extra orthogonal dimension of separation power, identify and quantify with more coverage and confidence, derive information on conformation and structure with mass spectrometry and deliver the most comprehensive structural characterization with novel fragmentation routines.
calculating a pH when a strong and weak acid are combined, calculating a pH when a weak acid and a salt containing its conjugate base are added, analogous base versions
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An ion scanner is also known as an ion mobility spectrometry device and is used for security reasons to scan for particulates and determine their substance of origin. It is used to detect illicit...
We discuss preliminary tests on a novel, high conductance inlet/conjoined ion guide system and restricted APCI nebulizer design that demonstrate a large improvement in sensitivity when compared to a conventional inlet MS.
Harvey DJ, Scarff CA, Edgeworth M, Struwe WB, Pagel K, Thalassinos K, Crispin M, Scrivens J. 2016. Travelling-wave ion mobility and negative ion fragmentation of high-mannose N-glycans.. J Mass Spectrom. 51(3):219-35. ...
According to the order of the prime mover model (power, speed) to confirm pump transmission mode, also to determin the pulley of the ...
All biology occurs in ionic mixtures loosely called Ringer solutions. Biology depends on interactions of ions. Interactions of Na+, K+, and Ca2+ with channel proteins produce electrical signals of nerves and coordinate muscle contraction including the heart. Proteins, channels, and nucleic acids concentrate small ions to number densities greater than 10 M because their active sites have large densities of acids and bases with permanent charge. ...
Ion Charge by Source Naturals, Inc. 02107802010. We carry every Source Naturals, Inc. product at discount prices. 4 oz Liquid 49% off, $10.19. Over 500 brands, 30000 products at discount prices 20-70% off.
They work directed on dual-labeling the vials of download Two Studies in Gas Phase Ion Spectroscopy: Vacuum Ultraviolet Negative Photoion Spectroscopy and Ion Molecule within use of reading, components, management, and starsA. They ve talked particular national employees( local alterations; nuclear) word representations, and full appetites. Pulitzer Arts Foundation100001002014-05-10T00:00:00Architecture Design of an affordable download Two Studies in Gas Phase Ion Spectroscopy: Vacuum Ultraviolet Negative Photoion Spectroscopy and Ion Molecule Reaction Kinetics in St. Louis MO wrote to the review.
Embodiments of a gas cluster ion beam apparatus and methods for forming a gas cluster ion beam using a low-pressure process source are generally described herein. In one embodiment, the low-pressure process source is mixed with a high-pressure diluent source in a static pump to form a mixed source, from which a gas cluster jet is generated and ionized to form the gas cluster ion beam. Other embodiments may be described and claimed.
An improved ion mobility spectrometer (IMS) and method for operating the same which enables analysis of ammonia in a mixture of gases when air is used as the carrier gas and the drift gas in the IMS.
A detector apparatus and its use for cluster ion beam diagnostics are described. The detector has a Faraday cup with a conductance path to a gas pressure detector and a conductance to the detector exit. The detector acquires ion current, which is a measure of the ion beam flux, and also acquires mass flux, through a pressure measurement. The pressure measurement responds to the mass of dissociated gas clusters and is combined with information about instantaneous ion current to estimate mean gas cluster ion size ({overscore (N)}i).
The program COMSOL Multiphysics was used to simulate a flow of helium gas transporting ionized fission products out of an ion guide. Two important parameters to study from the simulation was the evacuation time and velocity of the ions. The mean evacuation time was shown to be 0.1173s, and the velocity of a single particle peaked at 2500m/s, 1000-1500m/s being more common.. ...
The error you encountered has nothing to do with the presence of an ion accumulation mechanism. Impdedance.compute can be used in models that have ion accumulation mechanisms. The point of the "Warning" is to bring a potential source of error to the readers attention. Whether this particular error is significant or not in any particular model depends on the details of the model and is an empirical question--one that could be resolved by a computational experiment, similar to what you proposed: calculating impedance by injecting current and recording the resulting voltage. Keep in mind the fact that every model that does not include ion accumulation for each and every ionic species that crosses the cell membrane is itself full of potential sources of error. And for those few ionic species whose concentrations are state variables, in most cases it seems likely that the amplitude of ionic concentration changes is either small and characterized by a very slow time course compared to the amplitude ...
The energy dependence of fragmentation in a collision cell was measured for 2100 peptide ions derived from the digestion of twenty four common proteins.
Schematic diagram of selected ion flow tube (SIFT) apparatus.. SIFT-MS has been designed and constructed to allow on-line, real time analyses of the trace gases in ambient (polluted) air, exhaled breath and the headspace of aqueous liquids. The SIFT-MS analytical method combines fast flow tube techniques and quantitative mass spectrometry. The air/breath/headspace sample is introduced into fast flowing helium carrier gas where the trace gases in the sample react with embedded reagent ions (H3O+, NO+ or O2+) to produce characteristic product ions that identify the trace gases, and accurate quantification is achieved from knowledge of the kinetics of the ion/trace gas molecule reactions. Unlike other analytical techniques, an important feature of SIFT-MS analyses is that sample collection into bags or onto traps are not required, which can compromise the sample, and time consuming calibration is unnecessary. This allows the direct analysis of single exhalations of breath and provides the ...
Discrimination of single-porin Escherichia E. coli mutants by ATR and transmission mode FTIR spectroscopy Journal of Biophotonics , 2014, 7 , 392-400 Ral G. Saraiva, Joo Almeida Lopes, Jorge Machado, Paula Gameiro and Maria J. Feio Abstract Vibrational spectroscopy has long been used in bacterial identification with different levels of taxonomic...
TY - JOUR. T1 - Effect of the non-linear membrane potential on the migration of ionic species in concrete. AU - Marriaga, J.L.. AU - Claisse, Peter A.. PY - 2008/11. Y1 - 2008/11. KW - Concrete. KW - Electromigration. KW - Chloride modelling. KW - Membrane potential. KW - Ion transport. U2 - 10.1016/j.electacta.2008.11.031. DO - 10.1016/j.electacta.2008.11.031. M3 - Article. VL - 54. SP - 2761. EP - 2769. JO - Electrochimica Acta. JF - Electrochimica Acta. SN - 0013-4686. IS - 10. ER - ...
10T1/2 mouse cells were treated with nickel oxide, nickel monosulfide, and 3-methylcholanthrene to establish transformed cell lines. Non-transformed 10T1/2 cells expressed the vitamin D receptor interacting protein 80 (DRIP-80), while nickel ion-transformed cell lines did not. The DRIP-80 protein is a subunit of the Mediator complex, which regulates Ca+2 ion distribution via regulation of vitamin D responsive genes. Disruption of DRIP-80 gene expression may result in an aberrant distribution of Ca+2 ions. To test this hypothesis, non-transformed 10T1/2 cells and transformed 10T1/2 cell lines were stained with Fluo 3-AM and visualized by confocal microscopy. The distribution of Ca+2 ions in non-transformed 10T1/2 cells was heterogeneous. Nickel compound- and MCA-transformed 10T1/2 cells have consistently less Ca+2 ions in the nucleus than the cytoplasm. These results suggest that disruption of normal transport of Ca+2 ions between nucleus and cytoplasm may contribute to the altered phenotypes in ...
10T1/2 mouse cells were treated with nickel oxide, nickel monosulfide, and 3-methylcholanthrene to establish transformed cell lines. Non-transformed 10T1/2 cells expressed the vitamin D receptor interacting protein 80 (DRIP-80), while nickel ion-transformed cell lines did not. The DRIP-80 protein is a subunit of the Mediator complex, which regulates Ca+2 ion distribution via regulation of vitamin D responsive genes. Disruption of DRIP-80 gene expression may result in an aberrant distribution of Ca+2 ions. To test this hypothesis, non-transformed 10T1/2 cells and transformed 10T1/2 cell lines were stained with Fluo 3-AM and visualized by confocal microscopy. The distribution of Ca+2 ions in non-transformed 10T1/2 cells was heterogeneous. Nickel compound- and MCA-transformed 10T1/2 cells have consistently less Ca+2 ions in the nucleus than the cytoplasm. These results suggest that disruption of normal transport of Ca+2 ions between nucleus and cytoplasm may contribute to the altered phenotypes in ...
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In this study, Guggenheim charging process, which involves the radial Boltzmann distribution, was introduced to develop a new predictive model with three parameters, ion-ion distance parameter, ion-solvent parameter, and solvation parameter. In this model, the ion-ion and ion-solvent molecule interaction are all included in the charging process, and it is independent of the temperature and solvent. This new model was applied to correlate the experimental data from literatures for 208 electrolytes aqueous solution at T = 298.15 K of which the concentration range is wide. The calculated results agreed well with the experimental ones for most electrolytes, especially for the prediction in high ionic strength. The estimation of solvation parameter S also gave that the solvation tendency for cations and anions follow a trend, which is in consistent with results published in literature. Investigations were also been made in calculations for electrolytes solutions at other temperatures and non-aqueous ...
Based on our background we have first tackled the questions of equilibrium sorption of organic chemicals to various tissues and organs. In contrast to the often used Kow approach we consider storage lipids and membrane lipids as separate tissues with different sorption properties and we also take into account various proteins such as albumin, muscle proteins and collagen. All these equilibrium partition coefficients are estimated for neutral organic chemicals with our pp-LFER approach (Endo et al, 2013). In contrast, to neutral organic chemicals, sorption processes of ionic species are still not well understood. For sorption of ionic organic species in membrane lipids we have recently presented a promising approach (Bittermann et al., 2014). Sorption of ionic species in storage lipids is assumed to be negligible. In contrast, equilibrium sorption of ionic species to albumin and muscle protein cannot be ignored and is a matter of ongoing research in our group. ...
Video created by Universidad de Kentucky for the course Advanced Chemistry. This unit continues and expands on the theme of equlibria. You will examine buffers, acid/base titrations and the equilibria of insoluble salts.
i got the equations and the answers to these i just want to know the reason so i can do it next time on why Lif ph increases, Kis remains the same and that NH4Cls decreases . it would be a great help and this explanation might save my chemistry grade. thanks for the help ...
Presence of unresolved ion mobility (IM) profiles limits the efficient utilization of IM mass spectrometry (IM-MS) systems for isomer differentiation. Here, we introduce an automated ion mobility deco
When two oppositely charged macroions are brought into contact, a large fraction of the mobile counterions that previously surrounded each isolated macromolecule is released into the bulk solution, thereby increasing the counterions translational entropy. The entropy gain associated with this counterion release mechanism is the driving force for various macroion binding processes, such as protein-membrane, protein-DNA, and DNA-membrane complexation. In this review we focus on the role of counterion release in the interaction between charged macromolecules and oppositely charged lipid membranes. The electrostatic interaction is generally coupled to other degrees of freedom of the membrane, or of the adsorbed macroion. Thus, for example, when a basic protein adsorbs onto a binary fluid membrane comprising anionic and neutral lipids then, in addition to the release of the mobile counterions to the bulk solution, the protein polarizes the membrane composition by attracting the charged lipids to its ...
A buffer relates to the common ion effect, thus if you were to mix an aqueous solution of the acid and a fair amount of an aqueous solution of its conjugate salt, what youll have is a lower concentration of hydronium ions in the end. This is not a buffer problem. Also remember that the h-h equation is derived from pKa, its just a more convenient form when it comes to making buffers ...
LADDER ION GUIDE Safety Tips Page 2-3 Ladder Safety Tips - English Page 4-5 Ladder Safety Tips - Spanish Page 6 Fiberglass Step Ladder Comparison Chart Page 7 Aluminum Step Ladder Comparison Chart Page
Gas phase vs solution optimization. The fitting of the radii described above is usually done using gas phase optimized structures only, i.e. any change in structure and corresponding rotational and vibrational effects are "included" in the radii via the parameterization. However, for ionic species gas phase optimization can lead to significantly distorted structures or even proton transfer and in these cases solution phase optimizations and, hence, vibrational frequency calculations, tend to be used. However, numerical instability in the continuum models can make it necessary to increase (i.e. make less stringent) the geometry convergence criteria and can lead to more imaginary frequencies than in the gas phase. One option is to compute the vibrational contribution to $\Delta G^\circ_{\mathrm{RRHO}}$ using gas phase optimized structures ...
Grades 9 12. Students investigate reversible reactions and equilibrium. Using this knowledge, they investigate Le Châteliers principle, shifting equilibrium through the common ion effect and by varying the concentration of reactants. Kit includes materials for at least 30 students working in g...
4. If q amount of heat is supplied to a system, the work done by the system is w . What is the change in internal energy of the system ...
Autor: Manz, Christian; Genre: Hochschulschrift; Titel: Automated Analysis of Complex Carbohydrates via Ion Mobility-Mass Spectrometry
A laser-induced fluorescence (LIF) was used as a complimentary detection system for time-of-flight ion mobility spectrometry (TOF-IMS). A LIF detection system is potentially faster than a...
Date: May 1, 2017. Author: Ryan De Vooght-Johnson. Commercially farmed young eels tend to develop into males, rather than the heavier females, but this process can be altered by feeding them with female hormones. Scientists from Dalhousie University in Halifax, Canada, and local aquaculture firm NovaEel used LC-MS/MS in conjunction with differential ion mobility spectrometry to examine female hormone levels in farmed American eels, confirming that the levels dropped down to normal 5 days after treatment.. Read More ...
Proteomic measurements with greater throughput, sensitivity and additional structural information enhance the in-depth characterization of complex mixtures and targeted studies with additional information and higher confidence. While liquid chromatography separation coupled with mass spectrometry (LC-MS) measurements have provided information on thousands of proteins in different sample types, the additional of another rapid separation stage providing structural information has many benefits for analyses. Technical advances in ion funnels and multiplexing have enabled ion mobility separations to be easily and effectively coupled with LC-MS proteomics to enhance the information content of measurements. Finally, herein, we report on applications illustrating increased sensitivity, throughput, and structural information by utilizing IMS-MS and LC-IMS-MS measurements for both bottom-up and top-down proteomics measurements. ...
2014) Correction to "Effect of Nonelectrostatic Ion Interactions on Surface Forces Involving Ion Adsorption Equilibria". The Journal of Physical Chemistry C, 118 (36). p. 21299. ...
Large-scale molecular dynamics (MD) simulations are commonly used for simulating the synthesis and ion diffusion of battery materials. A good battery anode material is determined by its capacity to store ion or other diffusers. However, modeling of ion diffusion dynamics and transport properties at large length and long time scales would be impossible with current MD codes. To analyze the fundamental properties of these materials, therefore, we turn to geometric and topological analysis of their structure. In this paper, we apply a novel technique inspired by discrete Morse theory to the Delaunay triangulation of the simulated geometry of a thermally annealed carbon nanosphere. We utilize our computed structures to drive further geometric analysis to extract the interstitial diffusion structure as a single mesh. Lastly, our results provide a new approach to analyze the geometry of the simulated carbon nanosphere, and new insights into the role of carbon defect size and distribution in ...
1. It is shown that a neutral salt depresses the potential difference which exists at the point of equilibrium between a gelatin chloride solution contained in a collodion bag and an outside aqueous solution (without gelatin). The depressing effect of a neutral salt on the P.D. is similar to the depression of the osmotic pressure of the gelatin chloride solution by the same salt.. 2. It is shown that this depression of the P.D. by the salt can be calculated with a fair degree of accuracy on the basis of Nernsts logarithmic formula on the assumption that the P.D. which exists at the point of equilibrium is due to the difference of the hydrogen ion concentration on the opposite sides of the membrane.. 3. Since this difference of hydrogen ion concentration on both sides of the membrane is due to Donnans membrane equilibrium this latter equilibrium must be the cause of the P.D.. 4. A definite P.D. exists also between a solid block of gelatin chloride and the surrounding aqueous solution at the ...
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Bond Dissociation Energies Yu-Ran Luo The bond dissociation energy (enthalpy) is also referred to as bond disruption energy, bond energy, bond strength, or binding energy (abbreviation: BDE, BE, or D).
Bogdan Bogdanov (2001). Structures, thermochemistry, and dynamics of negative gas phase cluster ions studied by pulsed-ionization high pressure mass spectrometry and computational quantum chemistry techniques. UWSpace. http://hdl.handle.net/10012/667 ...
We investigate the ionic conductivities, phase behaviors, conformational states, and interactions of three ionic liquids based on imidazolium cations and phosphonate anions with varying alkyl chain lengths. All three ionic liquids show high conductivities, with 1,3-dimethylimidazolium methyl-phosphonate [DiMIm(MeO)(H)- PO2] being the most conductive (7.3 x 10(-3) S cm(-1) at 298 K). The high ionic conductivities are a result of the low glass-transition temperatures, T-g, which do not change significantly upon changing the cation and/or anion size. However, there is a slight dependence of the temperature behavior of the conductivity on the size of the ions, as seen from the fragility parameter (D) obtained from fits, to the Vogel-Fulcher-Tammann equation. The molecular-level structure and interactions of the phosphonate anions were examined by Raman spectroscopy and first-principles calculations: The calculations identify two stable conformations for the methyl- and ethyl-phosphonate anions by rotation
Precise vapor pressure data for pure acetonitrile and (LiBr + acetonitrile) are given for temps. ranging from 298.15 to 343.15 K. The molality range is from m = (0.0579 to 0.8298) mol/kg-1. The osmotic coeffs. are calcd. by taking into account the second virial coeff. of acetonitrile. The parameters of the extended Pitzer ion interaction model of Archer and the mole fraction-based thermodn. model of Clegg-Pitzer are evaluated. These models accurately reproduce the available osmotic coeffs. The parameters of the extended Pitzer ion interaction model of Archer are used to calc. the mean molal activity coeffs. ...
The Internal Energy Departure Function (11min, uakron.edu) Deriving departure functions for a variety of equations of state is simplified by transforming to dimensionless units and using density instead of volume. This also leads to an extra simplification for the internal energy departure function.. Comprehension Questions:. 1. What is the value of T(∂P/∂T)V - P for an ideal gas ...
TBI :: DESCRIPTION TBI (Tightly Bound Ion Model ) predicts the electrostatic free energy, the different free energy components, the average binding fraction of ions, and the most probable ion binding modes for a give
Ion Mobility Spectrometry and Direct Analysis in Real Time Mass Spectrometry can detect trace amounts of fentanyl even when mixed with heroin and other substances
PMCID: PMC3923399. "Advancing the high throughput identification of liver fibrosis protein signatures using multiplexed ion mobility spectrometry," E. S. Baker, K. E. Burnum-Johnson, J. M. Jacobs, D. L. Diamond, R. N. Brown, Y. M. Ibrahim, D. J. Orton, P. D. Piehowski, D. E. Purdy, R. J. Moore, W. F. Danielson, M. E. Monroe, K. L. Crowell, G. W. Slysz, M. A. Gritsenko, J. D. Sandoval, B. L. Lamarche, M. M. Matzke, B. J. Webb-Robertson, B. C. Simons, B. J. McMahon, R. Bhattacharya, J. D. Perkins, R. L. Carithers Jr., S. Strom, S. G. Self, M. G. Katze, G. A. Anderson, and R. D. Smith, Mol Cell Proteomics, 13 (4): 1119-1127 (2014 ...
Absolute dissociation cross sections are reported for Hn+ clusters of varied mass (n=3,5,,35) following collisions with He atoms at 60 keV/amu. Initial results have been published previously for a smaller range of cluster sizes [Ouaskit et al., Phys. Rev. A 49, 1484 (1994)]. The present extended study includes further experimental results, reducing the statistical errors associated with the absolute cross sections. The previously suggested quasilinear dependence of the Hn+ dissociation cross sections upon n is developed with reference to expected series of geometrical shells of H2 molecules surrounding a H3+ core. Recent calculations identify n=9 as corresponding to the first closed H2 shell [e.g., tich et al., J. Chem. Phys. 107, 9482 (1997)]. Recurrence of the distinct characteristics observed in the dissociation-cross-section dependence upon cluster size around n=9 provides the basis for the presently proposed subsequent closed shells at n=15, 21, 27, and 33, in agreement with the ...
The objective of the SIMCON research group is the study of the microscopic properties of liquids and solids by computer simulation. This methodology allow us a deeper undertanding of the basis of the properties of matter at atomic level. The systems now on study are, among others, molten salts, molecular liquids, ionic solutions, defects in crystalline metals, and quantum matter. The properties analysed are, basically, the structure and non-electronic transport properties in classic liquids and solids, the characteristics of the defects in crystals, and the thermodynamic and structural properties in quantum matter.. ...
The GYSELA code is a non-linear 5D global gyrokinetic full-f code which performs flux-driven simulations of ion temperature gradient driven turbulence (ITG) in the electrostatic limit with adiabatic electrons. It solves the standard gyrokinetic equation for the full-f distribution function, i.e. no assumption on scale separation between equilibrium and perturbations is done. This 5D equation is self-consistently coupled to a 3D quasineutrality equation. The code also includes ion-ion collisions in global simplified magnetic geometry (concentric toroidal magnetic surfaces with circular cross-sections). The system is driven out of thermodynamical equilibrium by versatile sources which are capable of injecting separately parallel momentum and heat. Alternate sources have also been studied, in order to excite supra-thermal particles. Finally, the code has the originality to be based on a semi-Lagrangian scheme and it is parallelized into an hybrid OpenMP/MPI paradigm. Recent simulations have ...
Struktur kristal natrium klorida. Setiap atom mempunyai enam jiran terdekat, dengan geometri oktahedron. Natrium klorid membentuk kristal dengan kiub simetri. Di dalamnya, ion klorin, ditunjukkan di sebelah kiri sebagai sfera hijau, disusun dalam bentuk padatan rapat kuib, sementara ion-ion yang lebih kecil adalah natrium, ditunjukkan di sebelah kiri sebagai (sfera biru, memenuhi jurang oktahedron di antara mereka). Setiap ion dikelilingi oleh enam ion yang berlainan jenis. Struktur asas ini boleh dijumpai dalam banyak mineral lain, ianya dikenali sebagai struktur halit. Susunan ini dikenali sebagai padatan rapat kuib (ccp).Ianya dipegang bersama oleh satu ikatan ion dan daya elektrostatik. ( http://ms.wikipedia.org/wiki/Nat/ Klorida ...
Q:42: At resting potential, the ion distribution inside and outside of a neuron is such that __________ ions are most abundant on the outside of the cell, while __________ ions are most abundant on the inside of the cell ...
The chemical imaging sensor is capable of visualizing the ion distribution. The spatial resolution of the chemical image depends on the horizontal diffusion of photocarriers generated by illumination. In this study; a novel optics is designed to realize a hybrid illumination of a ring of constant light and a spot of modulated light. Improved spatial resolution of the order of few tens of microns was successfully demonstrated.
Companion slide set to the video demonstration, Microbes and Disease, showing how best to teach the lesson of the same name. Students investigate select microbes and associated diseases, learn about transmission modes and impacts on society, and create art projects that represent the diseases.
I am doing an chemistry investigation (Bromate, bromide and hydrogen Ions reaction). The problem is that I have calculated the reaction rate in 1/time which gives me units s-1. However I have seen some examples of reaction equation and they include mol dm-3 s-1. In those example the table included 1/time as rate of reaction but when calculating the reaction constant k, they put units of rate of reaction as mol dm-3 s-1 even though the magnitude is exactly same as 1/time. ...
The technology of the IonizeMe Ionic Detoxifcation system has been in development for several decades. The induction of alternating positive and negative ion charges during the same treatment is based on a process called Iontophoresis. The FDA approved Iontophoresis as a healing modality in 1970. The feld of Electro-Th
Most information about kettlebell technique that exists today is focused on the biomechanical aspects of the many movements. However, what is not commonly known is how the management of internal energy, or what is called
Author: Göth, Melanie et al.; Genre: Thesis; Keywords: native mass spectrometry; ion mobility; protein complexes; Title: Investigation of Protein-Ligand Complexes by Native Mass Spectrometry and Ion Mobility-Mass Spectrometry
Ion mobility-mass spectrometry (IM-MS) is a rapid, gas-phase separation technique that has become an integral part of the analytical repertoire of techniques for the -omics. This method coupl
A novel ion/molecule reaction was observed to occur under electrospray ionization (ESI), atmospheric pressure chemical ionization (APCI), and atmospheric pressure photo ionization (APPI) conditions, leading to dimerization of ionized 4-(methyl mercapto)-phenol followed by fast H(center dot) loss. The reaction is particularly favored during ESI, which suggests that this ion/molecule reaction can occur both in the solution inside the ESI-charged droplets and in the gas-phase environment of most other atmospheric pressure ionization techniques. The dimerization reaction is inherent to the electrolytic process during ESI, whereas it is more by ion/molecule chemistry in nature during APCI and APPI. From the tandem mass spectrometry (MS/MS) data, accurate mass measurements, hydrogen/deuterium (H/D) exchange experiments and density functional theory (DFT) calculations, two methyl sulfonium ions appear to be the most likely products of this electrophilic aromatic substitution reaction. The possible ...
A comprehensive Collision Cross Section (CCS) library was obtained via Travelling Wave Ion Guide mobility measurements through direct infusion (DI). The library consists of CCS and Mass Spectral (MS) data in negative and positive ElectroSpray Ionisation (ESI) mode for 463 and 479 endogenous metabolites, respectively. For both ionisation modes combined, TWCCSN2 data were obtained for 542 non-redundant metabolites. These data were acquired on two different ion mobility enabled orthogonal acceleration QToF MS systems in two different laboratories, with the majority of the resulting TWCCSN2 values (from detected compounds) found to be within 1% of one another. Validation of these results against two independent, external TWCCSN2 data sources and predicted TWCCSN2 values indicated to be within 1-2% of these other values. The same metabolites were then analysed using a rapid reversed-phase ultra (high) performance liquid chromatographic (U(H)PLC) separation combined with IM and MS (IM-MS) thus ...
Considerable controversy exists in the literature as to the occurrence of intramolecular migration of amide hydrogens upon collisional activation of protonated peptides and proteins. This phenomenon has important implications for the application of CID as an experimental tool to obtain site-specific information about the incorporation of deuterium into peptides and proteins in solution. Using a unique set of peptides with their carboxyl-terminal half labeled with deuterium we have shown unambiguously that hydrogen (1H/2H) scrambling is such a dominating factor during low energy collisional activation of doubly protonated peptides that the original regioselective deuterium pattern of these peptides is completely erased (Jørgensen, T. J. D., Gårdsvoll, H., Ploug, M., and Roepstorff, P. (2005) Intramolecular migration of amide hydrogens in protonated peptides upon collisional activation. J. Am. Chem. Soc.127, 2785-2793). Taking further advantage of this unique test system we have now investigated ...
DATE: October 15, 2019TIME: 8:00am PDTIon mobility-mass spectrometry (IM/MS) is a rapid, gas-phase separation technique that has become an integral part of the analytical repertoire of t
An electroosmotic EO process is presented for nanoporous membranes capable of generating EO flow rates over thirty times higher than previously possible with the same membrane and solution. In...
adshelp[at]cfa.harvard.edu The ADS is operated by the Smithsonian Astrophysical Observatory under NASA Cooperative Agreement NNX16AC86A ...
Secondary ion mass spectrometry (SIMS) is used to analyze solid surfaces and thin films by sputtering the surface with a focused primary ion beam and collecting and analyzing ejected secondary ions. There are many different sources for a primary ion beam. However, the primary ion beam must contain ions that are at the higher end of the energy scale. Some common sources are: Cs+, O2+, O, Ar+ and Ga+.[5] SIMS imaging is performed in a manner similar to electron microscopy; the primary ion beam is emitted across the sample while secondary mass spectra are recorded.[6] SIMS proves to be advantageous in providing increased resolution for visualizing spatial distribution over smaller mass ranges.[1] SIMS is widely regarded as one of the most sensitive forms of mass spectrometry as it can detect elements as small as 10−6-10−9.[7]. Multiplexed ion beam imaging (MIBI) is a SIMS method that uses metal isotope labeled antibodies to label compounds in biological samples.[8]. Developments within SIMS: ...
A new method for the detection of gas-phase hydroperoxides is described. The clustering chemistry of CF3O- is exploited to produce speciated measurements of several hydroperoxides with high sensitivity and fast time response. Correspondence of airborne observations made with this technique and the established HPLC method is illustrated. CF3O- appears to be a highly versatile reagent ion for measurements of both weak and strong acids in the atmosphere.. ...
Despite recent advances in analytical and computational chemistry, lipid identification remains a significant challenge in lipidomics. Ion-mobility spectrometry provides an accurate measure of the molecules rotationally averaged collision cross-section (CCS) in the gas phase and is thus related to ionic shape. Here, we investigate the use of CCS as a highly specific molecular descriptor for identifying lipids in biological samples. Using traveling wave ion mobility mass spectrometry (MS), we measured the CCS values of over 200 lipids within multiple chemical classes. CCS values derived from ion mobility were not affected by instrument settings or chromatographic conditions, and they were highly reproducible on instruments located in independent laboratories (interlaboratory RSD , 3% for 98% of molecules). CCS values were used as additional molecular descriptors to identify brain lipids using a variety of traditional lipidomic approaches. The addition of CCS improved the reproducibility of ...
The experimental sequential bond energies for loss of water from Co2+(H2O)x complexes, x = 5-11, are determined by threshold collision-induced dissociation (TCID) using a guided ion beam tandem mass spectrometer with a thermal electrospray ionization source. Kinetic energy dependent TCID cross sections are a 2017 PCCP HOT Articles
How can ambient surface mass spectrometry, ion mobility spectrometry and gas-phase ion chemistry be combined to address key challenges for in situ analysis of biomolecules including spectral complexity, dynamic range, separation of isomers, structural elucidation (chemical structure & 3-D shape)?. ...
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An improved ion mobility spectrometer for detecting chemical warfare agents and hazardous vapors. The ion mobility spectrometer has an improved sensor cell that includes a heated air flow assembly, an
The timsTOF Pro powered by PASEF enables for the first time fast, ultra-sensitive shotgun proteomics and relative protein quantitation at high throughput over large cohort and low abundance sample studies, at an unprecedented level of robustness. The timsTOF Pro and timsTOF fleX are equipped with a Trapped Ion Mobility Spectrometry (TIMS) module that allows for the accurate determination of Collisional Cross Section (CCS) values for all detected ions. This intrinsic property significantly increases selectivity, whatever the acquisition strategy: 4D Match Between Runs enhances the quantification performance in Data Dependent Acquisition (DDA) PASEF approaches, while diaPASEF sets new selectivity and sensitivity standards for Data Independent Acquisition (DIA). ...
We report the design and evaluation of a new high-intensity electrospray ionization source for ion soft-landing experiments. The source incorporates a dual ion funnel, which enables operation with a higher gas load through an expanded diameter heated inlet into the additional first region of differential pum Analytical Sciences in the US
Membranes surround the individual cells of animals and organelles within the cell. They are composed of lipids and proteins. Specific proteins are responsible for the transport of specific inorganic ions across the membrane. Invariably, this transport of inorganic ions across […]
TY - JOUR. T1 - Screening and classifying small-molecule inhibitors of amyloid formation using ion mobility spectrometry-mass spectrometry. AU - Young, Lydia M.. AU - Saunders, Janet C.. AU - Mahood, Rachel A.. AU - Revill, Charlotte H.. AU - Foster, Richard J.. AU - Tu, Ling Hsien. AU - Raleigh, Daniel P.. AU - Radford, Sheena E.. AU - Ashcroft, Alison E.. PY - 2015/1/1. Y1 - 2015/1/1. N2 - The search for therapeutic agents that bind specifically to precursor protein conformations and inhibit amyloid assembly is an important challenge. Identifying such inhibitors is difficult because many protein precursors of aggregation are partially folded or intrinsically disordered, which rules out structure-based design. Furthermore, inhibitors can act by a variety of mechanisms, including specific or nonspecific binding, as well as colloidal inhibition. Here we report a high-throughput method based on ion mobility spectrometry-mass spectrometry (IMS-MS) that is capable of rapidly detecting small ...
0184] The following list is in the approximate order in which the processes occur during generation of an Ignitor Pulse: [0185] 1. From a closely-packed array of ion sources, generate a time-sequenced series of separate beams of a specific set of ion species in individual parallel channels. The set of heavy ion species may comprise isotopes of the same atomic element or a combination of atomic elements. [0186] 2. Accelerate the multiple beams from the source array in a HVDC structure with: the same array of parallel channels and close-coupled to the ion sources to maximize beam brightness. [0187] 3. Capture the DC beam in the RF fields of a radiofrequency quadrupole accelerator (RFQ) which: 1. Is integrated with and close-coupled to the HVDC accelerating structure, 2. Converts the time-sequenced DC pulses of the isotopic beams in parallel channels into trains (called a "macropulses") of "micropulses" at the RF frequency and 3. Further accelerates the ions to facilitate beam transport using ...
Close-up view of the ion source and ion gauge for a Bendix Corporation Time-of-Flight Mass Spectrometer. One of four component parts of a mass spectrometer, the ion source produces a beam of particles characteristic of…. ...
The harm that pathogens cause to hosts during infection, termed virulence, varies across species from negligible to a high likelihood of rapid death. Classic theory for the evolution of virulence is based on a trade-off between pathogen growth, transmission and host survival, which predicts that higher within-host growth causes increased transmission and higher virulence. However, using data from 61 human pathogens, we found the opposite correlation to the expected positive correlation between pathogen growth rate and virulence. We found that (i) slower growing pathogens are significantly more virulent than faster growing pathogens, (ii) inhaled pathogens and pathogens that infect via skin wounds are significantly more virulent than pathogens that are ingested, but (iii) there is no correlation between symptoms of infection that aid transmission (such as diarrhoea and coughing) and virulence. Overall, our results emphasize how virulence can be influenced by mechanistic life-history details, ...
Dr. Kenneth A. Snyder is the Deputy Division Chief of the Materials and Structural Systems Division (MSSD) within the Engineering Laboratory (EL) at the National Institute of Standards and Technology (NIST). Dr. Snyder joined the Inorganic Materials Group in 1990 as a staff scientist and was the Group Leader from 2009 to 2014.. Dr. Snyders primary area of research has been the diffusive transport of ionic species through cement paste pore solution. His approach was to identify the essential physical and chemical phenomena involved. Because transport is a critical component of virtually all degradation mechanisms, these studies are the basis of reliable predictive models for the performance assessment of concrete structures exposed to the environment.. An unexpected outcome of this fundamental work was the realization, by his colleague Dale Bentz, that one could decrease the rate of diffusive transport by increasing the viscosity experienced by a diffusing ionic species. This insight has led to ...
The presence of trace molecules in air is often determined using a well-known device called an ion mobility spectrometer. Such devices are commonly utilized in the fields of explosives detection, identification of narcotics, and in applications characterized by the presence of very low airborne concentrations of organic molecules of special interest. The sensitivity of such instruments is dependent on the concentration of target gas in the sample. The sampling efficiency can be greatly improved when the target object is warmed, even by only a few degrees. A directed emission of photons, typically infrared or visible light, can be used to significantly enhance vapor emission.
LOCATION: Erwin Schrödinger Lecture Hall, 5th floor, Boltzmanngasse 5, 1090 Vienna. ABSTRACT: One of the main research lines in magnetism is to embed the spin degrees of freedom into a molecular unit, taking advantage of the monodispersity of an ensemble of synthesized molecules with identical properties. The field of molecular spintronics aims to realize logic or storage devices, addressing the properties of single or few magnetic molecules deposited on opportune substrates/electrodes. The characterization of molecule-substrate interactions is therefore very timely and has raised in the last years a broad interest in the physics and chemists communities.. Along this line, I will present a theoretical density-functional investigation of magnetic molecule-substrate systems. The focus has been on single ion molecules, namely TM-phthalocyanines (TM=transition metals) [1,2], metallocenes (e.g. CoCp2) [3] and Ln double-deckers (e.g. TbPc2) [4,5], and we have investigated in detail the magnetic ...
Molecular ion [M + H]+ (A) and collision-induced dissociation(CID) fragmentation pattern (B) of enzymatically generated epoxide(compound 2), with mass per unit
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with photoresist lithography from the ion implantation process. This new ion implantation technology can reduce the raw process time, footprint, and the cost of ownership to less than one-half that of conventional ion implantation technology ...
View Notes - fields_lec9 from BIO 2.797j at MIT. Key Concepts for this section 1: Lorentz force law, Field, Maxwells equation 2: Ion Transport, Nernst-Planck equation 3: (Quasi)electrostatics,
[101 Pages Report] Check for Discount on Global Helium Mass Spectrometer Leak Detector Market Professional Survey Report 2017 report by QYResearch Group. This report studies Helium Mass Spectrometer Leak Detector in Global...