Texture zeros in neutrino mass matrix

Energy Technology Data Exchange (ETDEWEB)

Dziewit, B., E-mail: bartosz.dziewit@us.edu.pl; Holeczek, J., E-mail: jacek.holeczek@us.edu.pl; Richter, M., E-mail: monikarichter18@gmail.com [University of Silesia, Institute of Physics (Poland); Zajac, S., E-mail: s.zajac@uksw.edu.pl [Cardinal Stefan Wyszyński University in Warsaw, Faculty of Mathematics and Natural Studies (Poland); Zralek, M., E-mail: marek.zralek@us.edu.pl [University of Silesia, Institute of Physics (Poland)

2017-03-15

The Standard Model does not explain the hierarchy problem. Before the discovery of nonzero lepton mixing angle θ{sub 13} high hopes in explanation of the shape of the lepton mixing matrix were combined with non-Abelian symmetries. Nowadays, assuming one Higgs doublet, it is unlikely that this is still valid. Texture zeroes, that are combined with abelian symmetries, are intensively studied. The neutrino mass matrix is a natural way to study such symmetries.

Octopus-inspired drag cancelation by added mass pumping

Science.gov (United States)

Weymouth, Gabriel; Giorgio-Serchi, Francesco

2016-11-01

Recent work has shown that when an immersed body suddenly changes its size, such as a deflating octopus during rapid escape jetting, the body experiences large forces due to the variation of added-mass energy. We extend this line of research by investigating a spring-mass oscillator submerged in quiescent fluid subject to periodic changes in its volume. This system isolates the ability of the added-mass thrust to cancel the bluff body resistance (having no jet flow to confuse the analysis) and moves closer to studying how these effects would work in a sustained propulsion case by studying periodic shape-change instead of a "one-shot" escape maneuver. With a combination of analytical, numerical, and experimental results, we show that the recovery of added-mass kinetic energy can be used to completely cancel the drag of the fluid, driving the onset of sustained oscillations with amplitudes as large as four times the average body radius. Moreover, these results are fairly independent of the details of the shape-change kinematics as long as the Stokes number and shape-change number are large. In addition, the effective pumping frequency range based on parametric oscillator analysis is shown to predict large amplitude response region observed in the numerics and experiments.

Calculation of Added Mass for Submerged Reactor with Complex Shape

Energy Technology Data Exchange (ETDEWEB)

Sun, Jong-Oh; Kim, Gyeongho; Choo, Yeon-Seok; Yoo, Yeon-Sik [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2016-10-15

Kijang Research Reactor (KJRR) is currently under construction. Its reactor is located on the bottom of a reactor pool which is filled with water to a depth of 12m. Some components are installed on or inside the reactor and their structural integrity and safety performance need to be verified under seismic situations. For the verification, time history data or Floor Response Spectrum (FRS) on their support location, which is the reactor, should be obtained. A Finite Element (FE) model with fluid elements can give very accurate results for the matter; however, it costs too many resources and takes too much time for the transient analyses. In order to make the model more efficient and simple, added masses are often used to simulate the effect of water instead of the fluid elements. Many literatures introduce methods to calculate the added mass according to the exterior shape of structures. In this paper, how to calculate added masses for complex shaped structure was suggested. The proposed method was applied to RSA for KJRR and its accuracy was verified through comparison of the natural frequencies of RSA with fluid elements and the added masses. They showed the differences less than 1.5% between two models. Finally, it is concluded that the proposed method is quite useful to obtain added masses for complex shaped structure.

An algorithm for mass matrix calculation of internally constrained molecular geometries

International Nuclear Information System (INIS)

Aryanpour, Masoud; Dhanda, Abhishek; Pitsch, Heinz

2008-01-01

Dynamic models for molecular systems require the determination of corresponding mass matrix. For constrained geometries, these computations are often not trivial but need special considerations. Here, assembling the mass matrix of internally constrained molecular structures is formulated as an optimization problem. Analytical expressions are derived for the solution of the different possible cases depending on the rank of the constraint matrix. Geometrical interpretations are further used to enhance the solution concept. As an application, we evaluate the mass matrix for a constrained molecule undergoing an electron-transfer reaction. The preexponential factor for this reaction is computed based on the harmonic model

An algorithm for mass matrix calculation of internally constrained molecular geometries.

Science.gov (United States)

Aryanpour, Masoud; Dhanda, Abhishek; Pitsch, Heinz

2008-01-28

Dynamic models for molecular systems require the determination of corresponding mass matrix. For constrained geometries, these computations are often not trivial but need special considerations. Here, assembling the mass matrix of internally constrained molecular structures is formulated as an optimization problem. Analytical expressions are derived for the solution of the different possible cases depending on the rank of the constraint matrix. Geometrical interpretations are further used to enhance the solution concept. As an application, we evaluate the mass matrix for a constrained molecule undergoing an electron-transfer reaction. The preexponential factor for this reaction is computed based on the harmonic model.

Generalized added masses computation for fluid structure interaction

International Nuclear Information System (INIS)

Lazzeri, L.; Cecconi, S.; Scala, M.

1983-01-01

The aim of this paper a description of a method to simulate the dynamic effect of a fluid between two structures by means of an added mass and an added stiffness. The method is based on a potential theory which assumes the fluid is inviscid and incompressible (the case of compressibility is discussed); a solution of the corresponding field equation is given as a superposition of elementary conditions (i.e. applicable to elementary boundary conditions). Consequently the pressure and displacements of the fluid on the boundary are given as a function of the series coefficients; the ''work lost'' (i.e. the work done by the pressures on the difference between actual and estimated displacements) is minimized, in this way the expansion coefficients are related to the displacements on the boundaries. Virtual work procedures are then used to compute added masses. The particular case of a free surface (with gravity effects) is discussed, it is shown how the effect can be modelled by means of an added stiffness term. Some examples relative to vibrations in reservoirs are given and discussed. (orig.)

Froggatt-Nielsen hierarchy and the neutrino mass matrix

International Nuclear Information System (INIS)

Kamikado, H.; Takasugi, E.

2008-05-01

We study the neutrino mass matrix derived from the seesaw mechanism in which the neutrino Yukawa couplings and the heavy Majorana neutrino mass matrix are controlled by the Froggatt-Nielsen mechanism. In order to obtain the large neutrino mixings, two Froggatt-Nielsen fields are introduced with a complex vacuum expectation values. As a by-product, CP violation is systematically induced even if the order one couplings of FN fields are real. We show several predictions of this model, such as θ 13 , the Dirac CP phase, two Majorana CP phases, the effective mass of the neutrinoless double beta decay and the leptogenesis. The prediction of the branching ratio of μ→eγ is also given in SUSY model. (orig.)

Matrix-assisted laser desorption fourier transform mass spectrometry for biological compounds

Energy Technology Data Exchange (ETDEWEB)

Hettich, R.; Buchanan, M.

1990-01-01

The recent development of matrix-assisted UV laser desorption (LD) mass spectrometry has made possible the ionization and detection of extremely large molecules (with molecular weights exceeding 100,000 Daltons). This technique has generated enormous interest in the biological community for the direct examination of large peptides and oligonucleotides. Although this matrix-assisted ionization method has been developed and used almost exclusively with time-of-flight (TOF) mass spectrometers, research is currently in progress to demonstrate this technique with trapped ion mass spectrometers, such as Fourier transform ion cyclotron resonance mass spectrometry (FTMS). The potential capabilities of FTMS for wide mass range, high resolution measurement, and ion trapping experiments suggest that this instrumental technique should be useful for the detailed structural characterization of large ions generated by the matrix-assisted technique. We have recently demonstrated that matrix-assisted ultraviolet laser desorption can be successfully used with FTMS for the ionization of small peptides. The objective of this report is to summarize the application and current limitations of matrix-assisted laser desorption FTMS for the characterization of peptides and oligonucleotides at the isomeric level. 4 refs., 3 figs., 2 tabs.

Water-Exit Process Modeling and Added-Mass Calculation of the Submarine-Launched Missile

Directory of Open Access Journals (Sweden)

Yang Jian

2017-11-01

Full Text Available In the process that the submarine-launched missile exits the water, there is the complex fluid solid coupling phenomenon. Therefore, it is difficult to establish the accurate water-exit dynamic model. In the paper, according to the characteristics of the water-exit motion, based on the traditional method of added mass, considering the added mass changing rate, the water-exit dynamic model is established. And with help of the CFX fluid simulation software, a new calculation method of the added mass that is suit for submarine-launched missile is proposed, which can effectively solve the problem of fluid solid coupling in modeling process. Then by the new calculation method, the change law of the added mass in water-exit process of the missile is obtained. In simulated analysis, for the water-exit process of the missile, by comparing the results of the numerical simulation and the calculation of theoretical model, the effectiveness of the new added mass calculation method and the accuracy of the water-exit dynamic model that considers the added mass changing rate are verified.

Focused Electrospray Deposition for Matrix-assisted Laser Desorption/Ionization Mass Spectrometry

International Nuclear Information System (INIS)

Jeong, Kyung Hwan; Seo, Jong Cheol; Yoon, Hye Joo; Shin, Seung Koo

2010-01-01

Focused electrospray (FES) deposition method is presented for matrix-assisted laser desorption/ionization (MALDI) mass spectrometry. FES ion optics consists of two cylindrical focusing electrodes capped with a truncated conical electrode through which an electrospray emitter passes along the cylindrical axis. A spray of charged droplets is focused onto a sample well on a MALDI target plate under atmospheric pressure. The shape and size distributions of matrix crystals are visualized by scanning electron microscope and the mass spectra are obtained by time-of-flight mass spectrometry. Angiotensin II, bradykinin, and substance P are used as test samples, while α-cyano-4-hydroxycinnamic acid and dihydroxybenzoic acid are employed as matrices. FES of a sample/matrix mixture produces fine crystal grains on a 1.3 mm spot and reproducibly yields the mass spectra with little shot-to-shot and spot-to-spot variations. Although FES greatly stabilizes the signals, the space charge due to matrix ions limits the detection sensitivity of peptides. To avoid the space charge problem, we adopted a dual FES/FES mode, which separately deposits matrix and sample by FES in sequence. The dual FES/FES mode reaches the detection sensitivity of 0.88 amol, enabling ultrasensitive detection of peptides by homogeneously depositing matrix and sample under atmospheric pressure

Added Mass of a Spherical Cap Body

Czech Academy of Sciences Publication Activity Database

Šimčík, Miroslav; Punčochář, Miroslav; Růžička, Marek

2014-01-01

Roč. 118, OCT 18 (2014), s. 1-8 ISSN 0009-2509 R&D Projects: GA MŠk(CZ) LD13018 Institutional support: RVO:67985858 Keywords : spherical cap * added mass * single particle Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 2.337, year: 2014

Generalized derivation of the added-mass and circulatory forces for viscous flows

Science.gov (United States)

Limacher, Eric; Morton, Chris; Wood, David

2018-01-01

The concept of added mass arises from potential flow analysis and is associated with the acceleration of a body in an inviscid irrotational fluid. When shed vorticity is modeled as vortex singularities embedded in this irrotational flow, the associated force can be superimposed onto the added-mass force due to the linearity of the governing Laplace equation. This decomposition of force into added-mass and circulatory components remains common in modern aerodynamic models, but its applicability to viscous separated flows remains unclear. The present work addresses this knowledge gap by presenting a generalized derivation of the added-mass and circulatory force decomposition which is valid for a body of arbitrary shape in an unbounded, incompressible fluid domain, in both two and three dimensions, undergoing arbitrary motions amid continuous distributions of vorticity. From the general expression, the classical added-mass force is rederived for well-known canonical cases and is seen to be additive to the circulatory force for any flow. The formulation is shown to be equivalent to existing theoretical work under the specific conditions and assumptions of previous studies. It is also validated using a numerical simulation of a pitching plate in a steady freestream flow, conducted by Wang and Eldredge [Theor. Comput. Fluid Dyn. 27, 577 (2013), 10.1007/s00162-012-0279-5]. In response to persistent confusion in the literature, a discussion of the most appropriate physical interpretation of added mass is included, informed by inspection of the derived equations. The added-mass force is seen to account for the dynamic effect of near-body vorticity and is not (as is commonly claimed) associated with the acceleration of near-body fluid which "must" somehow move with the body. Various other consequences of the derivation are discussed, including a concept which has been labeled the conservation of image-vorticity impulse.

Global dynamics of asymptotically locally AdS spacetimes with negative mass

Science.gov (United States)

Dold, Dominic

2018-05-01

The Einstein vacuum equations in 5D with negative cosmological constant are studied in biaxial Bianchi IX symmetry. We show that if initial data of Eguchi–Hanson type, modelled after the 4D Riemannian Eguchi–Hanson space, have negative mass, the future maximal development does not contain horizons, i. e. the complement of the causal past of null infinity is empty. In particular, perturbations of Eguchi–Hanson–AdS spacetimes within the biaxial Bianchi IX symmetry class cannot form horizons, suggesting that such spacetimes are potential candidates for a naked singularity to form. The proof relies on an extension principle proven for this system and a priori estimates following from the monotonicity of the Hawking mass.

Kinetic energy and added mass of hydrodynamically interacting gas bubbles in liquid

NARCIS (Netherlands)

Kok, Jacobus B.W.

1988-01-01

By averaging the basic equations on microscale, expressions are derived for the effective added mass density and the kinetic energy density of a mixture of liquid and gas bubbles. Due to hydrodynamic interaction between the bubbles there appears to be a difference between the effective added mass

CFD Based Added Mass Prediction in Cruise Condition of Underwater Vehicle Dynamic

Science.gov (United States)

Agoes Moelyadi, Mochammad; Bambang Riswandi, Bagus

2018-04-01

One of the unsteady flow behavior on the hydrodynamic characteristics of underwater vehicle is the presence of added mass. In cruising conditions, the underwater vehicle may require the addition of speed or experience the disturbance in the form of unsteady flow so that cause the hydrodynamic interaction between the surface of the vehicle with the surrounding fluid. This leads to the rise of local velocity of flow and the great changes of hydrodynamic forces which are very influential on the stability of the underwater vehicle. One of the result is an additional force called added mass. It is very useful parameter to control underwater vehicle dynamic.This paper reports the research on the added mass coefficient of underwater vehicles obtained through the Computational Fluid Dynmaic (CFD) simulation method using CFX software. Added mass coefficient is calculated by performing an unsteady simulation or known as transient simulation. Computational simulations are based on the Reynold Average Navier- Stokes (RANS) equation solution. The simulated vehicle moves forward and backward according to the sinus function, with a frequency of 0.25 Hz, a 2 m amplitude, a cruising depth of 10 m below sea level, and Vcruise 1.54 m / s (Re = 9.000.000). Simulation result data includes velocity contour, variation of force and acceleration to frequency, and added mass coefficient.

Capsule Typing of Haemophilus influenzae by Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry.

Science.gov (United States)

Månsson, Viktor; Gilsdorf, Janet R; Kahlmeter, Gunnar; Kilian, Mogens; Kroll, J Simon; Riesbeck, Kristian; Resman, Fredrik

2018-03-01

Encapsulated Haemophilus influenzae strains belong to type-specific genetic lineages. Reliable capsule typing requires PCR, but a more efficient method would be useful. We evaluated capsule typing by using matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry. Isolates of all capsule types (a-f and nontypeable; n = 258) and isogenic capsule transformants (types a-d) were investigated. Principal component and biomarker analyses of mass spectra showed clustering, and mass peaks correlated with capsule type-specific genetic lineages. We used 31 selected isolates to construct a capsule typing database. Validation with the remaining isolates (n = 227) showed 100% sensitivity and 92.2% specificity for encapsulated strains (a-f; n = 61). Blinded validation of a supplemented database (n = 50) using clinical isolates (n = 126) showed 100% sensitivity and 100% specificity for encapsulated strains (b, e, and f; n = 28). MALDI-TOF mass spectrometry is an accurate method for capsule typing of H. influenzae.

Supergravity duals of matrix string theory

International Nuclear Information System (INIS)

Morales, Jose F.; Samtleben, Henning

2002-01-01

We study holographic duals of type II and heterotic matrix string theories described by warped AdS 3 supergravities. By explicitly solving the linearized equations of motion around near horizon D-string geometries, we determine the spectrum of Kaluza-Klein primaries for type I, II supergravities on warped AdS 3 xS 7 . The results match those coming from the dual two-dimensional gauge theories living on the D-string worldvolumes. We briefly discuss the connections with the N=(8,8), N=(8,0) orbifold superconformal field theories to which type IIB/heterotic matrix strings flow in the infrared. In particular, we associate the dimension (h,h-bar) (32,32) twisted operator which brings the matrix string theories out from the conformal point (R; 8 ) N /S N with the dilaton profile in the supergravity background. The familiar dictionary between masses and 'scaling' dimensions of field and operators are modified by the presence of non-trivial warp factors and running dilatons. These modifications are worked out for the general case of domain wall/QFT correspondences between supergravities on warped AdS d+1 xS q geometries and super Yang-Mills theories with 16 supercharges. (author)

Depletion of atmospheric muon-neutrino fluxes and structure of Majorana mass matrix

International Nuclear Information System (INIS)

Tanimoto, Morimitsu; Matsuda, Masahisa

1993-01-01

We study the structures of the Dirac and Majorana mass matrices which give rise to the large lepton mixing expected from the depleted atmospheric muonneutrino flux. In the case that the Majorana mass matrix has a hierarchy for generations, a certain kind of the neutrino Dirac mass matrix with the hierarchical structure leads to the large lepton mixing between the second generation and the third one. Our model-independent analyses serve the model-building of the mass matrices based on the quark-lepton unified theory. (orig.)

Mass spectrometry imaging of illicit drugs in latent fingerprints by matrix-free and matrix-assisted desorption/ionization techniques.

Science.gov (United States)

Skriba, Anton; Havlicek, Vladimir

2018-02-01

Compared with classical matrix-assisted laser-desorption ionization mass spectrometry (MALDI), the matrix free-based strategies generate a cleaner background, without significant noise or interference coming from an applied matrix, which is beneficial for the analysis of small molecules, such as drugs of abuse. In this work, we probed the detection efficiency of methamphetamine, heroin and cocaine in nanostructure-assisted laser desorption-ionization (NALDI) and desorption electrospray ionization and compared the sensitivity of these two matrix-free tools with a standard MALDI mass spectrometry experiment. In a typical mass spectrometry imaging (MSI) setup, papillary line latent fingerprints were recorded as a mixture a common skin fatty acid or interfering cosmetics with a drug. In a separate experiment, all drugs (1 µL of 1 μM standard solution) were detected by all three ionization techniques on a target. In the case of cocaine and heroin, NALDI mass spectrometry was the most sensitive and revealed signals even from 0.1 μM solution. The drug/drug contaminant (fatty acid or cosmetics) MSI approach could be used by law enforcement personnel to confirm drug abusers of having come into contact with the suspected drug by use of fingerprint scans at time of apprehension which can aid in reducing the work of lab officials.

Nonzero θ13 and neutrino masses from the modified tri-bi-maximal neutrino mixing matrix

International Nuclear Information System (INIS)

Damanik, A.

2014-01-01

There are 3 types of neutrino mixing matrices: tri-bi-maximal, bi-maximal and democratic. These 3 types of neutrino mixing matrices predict that the mixing angle θ 13 should be null. Motivated by the recent experimental evidence of nonzero and relatively large θ 13 , we modified the tribimaximal mixing matrix by introducing a simple perturbation matrix into tribimaximal neutrino mixing matrix. In this scenario, we obtained nonzero mixing angle θ 13 =7.9 degrees which is in agreement with the present experimental results. By imposing 2 zeros texture into the obtained neutrino mass matrix from modified tribimaximal mixing matrix, we then have the neutrino mass spectrum in normal hierarchy. Some phenomenological implications are also discussed. It appears that if we use the solar neutrino squared-mass difference to determine the values of neutrino masses, then we cannot have the correct value for the atmospheric squared-mass difference. Conversely, if we use the experimental value of the squared-mass difference to determine the neutrino masses, then we cannot have the correct value for the solar neutrino squared-mass difference

Empirical Coulomb matrix elements and the mass of 22Al

International Nuclear Information System (INIS)

Whitehead, R.R.; Watt, A.; Kelvin, D.; Rutherford, H.J.

1976-01-01

An attempt has been made to obtain a set of Coulomb matrix elements which fit the known Coulomb energy shifts in the nuclei of mass 18 to 22. The interaction obtained fits the data well with only a few exceptions, one of these being the Coulomb shift of the notorious third 0 + state in 18 Ne. These Coulomb matrix elements are used together with the Chung-Wildenthal interaction to obtain a new prediction for the mass excess of 22 Al. The results indicate that 22 Al should be bound against proton emission. (Auth.)

The Effect of an Added Mass on the Frequency Shifts of a Clamped-Clamped Microbeam for Bio-Mass Detection

KAUST Repository

Bouchaala, Adam M.

2016-12-05

We present analytical formulations to calculate the induced resonance frequency shifts of electrically actuated clamped-clamped microbeams due to an added mass. Based on the Euler-Bernoulli beam theory, we investigate the linear dynamic responses of the beams added masses, which are modeled as discrete point masses. Analytical expressions based on perturbation techniques and a one-mode Galerkin approximation are developed to calculate accurately the frequency shifts under a DC voltage as a function of the added mass and position. The analytical results are compared to numerical solution of the eigenvalue problem. Results are shown for the fundamental as well as the higher-order modes of the beams. The results indicate a significant increase in the frequency shift, and hence the sensitivity of detection, when scaling down to nano scale and using higher-order modes.

The Effect of an Added Mass on the Frequency Shifts of a Clamped-Clamped Microbeam for Bio-Mass Detection

KAUST Repository

Bouchaala, Adam M.; Nayfeh, Ali H.; Younis, Mohammad I.

2016-01-01

We present analytical formulations to calculate the induced resonance frequency shifts of electrically actuated clamped-clamped microbeams due to an added mass. Based on the Euler-Bernoulli beam theory, we investigate the linear dynamic responses of the beams added masses, which are modeled as discrete point masses. Analytical expressions based on perturbation techniques and a one-mode Galerkin approximation are developed to calculate accurately the frequency shifts under a DC voltage as a function of the added mass and position. The analytical results are compared to numerical solution of the eigenvalue problem. Results are shown for the fundamental as well as the higher-order modes of the beams. The results indicate a significant increase in the frequency shift, and hence the sensitivity of detection, when scaling down to nano scale and using higher-order modes.

Added-Mass Effects on a Horizontal-Axis Tidal Turbine Using FAST v8

Energy Technology Data Exchange (ETDEWEB)

Murray, Robynne [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Thresher, Robert W [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Jonkman, Jason [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

2018-04-09

Added mass on tidal turbine blades has the potential to alter the blade dynamic response, such as natural frequencies and vibration amplitudes, as a response to blade acceleration. Currently, most aeroelastic design tools do not consider such effects as they are complex and expensive to model, and they are not an intrinsic part of most blade-element momentum theory codes, which are commonly used in the tidal energy industry. This article outlines the addition of added-mass effects to the National Renewable Energy Laboratory's design tool FAST v8. A verification is presented for a spring-mass system with an initial displacement, and a case study is performed for the Reference Model 1 20-m-diameter tidal turbine. For the 20-m-diameter turbine, it was shown that the natural frequency of vibration is reduced by 65% when added mass is considered. Further, the thrust loads are increased by 2.5% when the blades are excited by a 5% step increase in inflow velocity when added mass is considered. This decrease can have a significant impact on the overall turbine design, as it is important to design the blades with a natural frequency so that they are not excited by the rotor speed and its harmonics, wherein aerodynamic excitation can lead to fatigue damage. However, it was shown that when turbulent inflow with an intensity of 20% was modeled, there was almost no impact on the loads and blade displacement with added-mass effects except for a small difference in the fatigue response of the blade to turbulent load fluctuations.

Effects of dynamic matrix remodelling on en masse migration of fibroblasts on collagen matrices.

Science.gov (United States)

Ozcelikkale, Altug; Dutton, J Craig; Grinnell, Frederick; Han, Bumsoo

2017-10-01

Fibroblast migration plays a key role during various physiological and pathological processes. Although migration of individual fibroblasts has been well studied, migration in vivo often involves simultaneous locomotion of fibroblasts sited in close proximity, so-called ' en masse migration', during which intensive cell-cell interactions occur. This study aims to understand the effects of matrix mechanical environments on the cell-matrix and cell-cell interactions during en masse migration of fibroblasts on collagen matrices. Specifically, we hypothesized that a group of migrating cells can significantly deform the matrix, whose mechanical microenvironment dramatically changes compared with the undeformed state, and the alteration of the matrix microenvironment reciprocally affects cell migration. This hypothesis was tested by time-resolved measurements of cell and extracellular matrix movement during en masse migration on collagen hydrogels with varying concentrations. The results illustrated that a group of cells generates significant spatio-temporal deformation of the matrix before and during the migration. Cells on soft collagen hydrogels migrate along tortuous paths, but, as the matrix stiffness increases, cell migration patterns become aligned with each other and show coordinated migration paths. As cells migrate, the matrix is locally compressed, resulting in a locally stiffened and dense matrix across the collagen concentration range studied. © 2017 The Author(s).

Organic Aerosol Component (OACOMP) Value-Added Product Report

Energy Technology Data Exchange (ETDEWEB)

Fast, J; Zhang, Q; Tilp, A; Shippert, T; Parworth, C; Mei, F

2013-08-23

Significantly improved returns in their aerosol chemistry data can be achieved via the development of a value-added product (VAP) of deriving OA components, called Organic Aerosol Components (OACOMP). OACOMP is primarily based on multivariate analysis of the measured organic mass spectral matrix. The key outputs of OACOMP are the concentration time series and the mass spectra of OA factors that are associated with distinct sources, formation and evolution processes, and physicochemical properties.

Large νμ-ντ mixing and the structure of right-handed Majorana mass matrix

International Nuclear Information System (INIS)

Matsuda, Masahisa

1993-01-01

Recent solar neutrino and atmospheric neutrino experiment suggest the existence of the large lepton mixing among 2nd and 3rd generation neutrino. This fact gives the important information on the structure of right-handed Majorana neutrino. It is shown that, if we assume that the neutrino Dirac mass matrix is similar to the mass matrix of the up-quark sector, the large lepton mixing among the 2nd and the 3rd generation requires the hierarchical structure of the Majorana mass matrix. This model-independent analyses serve the model-building of the mass matrices based on the quark-lepton unified theory. (author)

Investigation of dynamic characteristics of shells with holes and added mass

Directory of Open Access Journals (Sweden)

Seregin Sergey Valer’evich

2014-04-01

Full Text Available Thin cylindrical shells are widely used in construction, engineering and other industries. In case of designing a reservoir for the isothermal storage of liquefied gases such cases are inevitable, when housing requires various technical holes. A point wise added mass can appear into practice in the form of suspended spotlights, radar, architectural inclusions in buildings and structures of various purposes. It is known, that the dynamic asymmetry as an initial irregular geometric shape, including holes, and the added mass leads to specific effects in shells. In the paper the impact of a cut on the frequency and form of its own vibrations of thin circular cylindrical shells is theoretically examined with the help of the equations of linear shallow shell theory. For modal equations with Nav’e boundary conditions, we used the Bubnov - Galerkin method. The authors have expressed a formula for finding the lowest of the split-frequency vibrations of a shell with a cutout. It is stated, that in case of an appropriate choice of added mass value the lower frequencies are comparable with the case of vibrations of a shell with a hole. By numerical and experimental modeling and finite element method in the environment of MSC "Nastran" oscillation frequencies a shell supporting a concentrated mass and a shell with a cutout were compared. It is shown, that the results of the dynamic analysis of shells with holes with a suitable choice of the attached mass values are comparable with the results of the analysis of shells carrying a point mass. It was concluded that the edges in the holes, significantly affect the reduction in the lowest frequency, and need to be strengthened.

Neutrino mass matrices with two vanishing cofactors and Fritzsch texture for charged lepton mass matrix

Science.gov (United States)

Wang, Weijian; Guo, Shu-Yuan; Wang, Zhi-Gang

2016-04-01

In this paper, we study the cofactor 2 zero neutrino mass matrices with the Fritzsch-type structure in charged lepton mass matrix (CLMM). In the numerical analysis, we perform a scan over the parameter space of all the 15 possible patterns to get a large sample of viable scattering points. Among the 15 possible patterns, three of them can accommodate the latest lepton mixing and neutrino mass data. We compare the predictions of the allowed patterns with their counterparts with diagonal CLMM. In this case, the severe cosmology bound on the neutrino mass set a strong constraint on the parameter space, rendering two patterns only marginally allowed. The Fritzsch-type CLMM will have impact on the viable parameter space and give rise to different phenomenological predictions. Each allowed pattern predicts the strong correlations between physical variables, which is essential for model selection and can be probed in future experiments. It is found that under the no-diagonal CLMM, the cofactor zeros structure in neutrino mass matrix is unstable as the running of renormalization group (RG) from seesaw scale to the electroweak scale. A way out of the problem is to propose the flavor symmetry under the models with a TeV seesaw scale. The inverse seesaw model and a loop-induced model are given as two examples.

Carbon nanotubes as adsorbent of solid-phase extraction and matrix for laser desorption/ionization mass spectrometry.

Science.gov (United States)

Pan, Chensong; Xu, Songyun; Zou, Hanfa; Guo, Zhong; Zhang, Yu; Guo, Baochuan

2005-02-01

A method with carbon nanotubes functioning both as the adsorbent of solid-phase extraction (SPE) and the matrix for matrix assisted laser desorption/ionization mass spectrometry (MALDI-MS) to analyze small molecules in solution has been developed. In this method, 10 microL suspensions of carbon nanotubes in 50% (vol/vol) methanol were added to the sample solution to extract analytes onto surface of carbon nanotubes because of their dramatic hydrophobicity. Carbon nanotubes in solution are deposited onto the bottom of tube with centrifugation. After removing the supernatant fluid, carbon nanotubes are suspended again with dispersant and pipetted directly onto the sample target of the MALDI-MS to perform a mass spectrometric analysis. It was demonstrated by analysis of a variety of small molecules that the resolution of peaks and the efficiency of desorption/ionization on the carbon nanotubes are better than those on the activated carbon. It is found that with the addition of glycerol and sucrose to the dispersant, the intensity, the ratio of signal to noise (S/N), and the resolution of peaks for analytes by mass spectrometry increased greatly. Compared with the previously reported method by depositing sample solution onto thin layer of carbon nanotubes, it is observed that the detection limit for analytes can be enhanced about 10 to 100 times due to solid-phase extraction of analytes in solution by carbon nanotubes. An acceptable result of simultaneously quantitative analysis of three analytes in solution has been achieved. The application in determining drugs spiked into urine has also been realized.

Three loop massive operator matrix elements and asymptotic Wilson coefficients with two different masses

Directory of Open Access Journals (Sweden)

J. Ablinger

2017-08-01

Full Text Available Starting at 3-loop order, the massive Wilson coefficients for deep-inelastic scattering and the massive operator matrix elements describing the variable flavor number scheme receive contributions of Feynman diagrams carrying quark lines with two different masses. In the case of the charm and bottom quarks, the usual decoupling of one heavy mass at a time no longer holds, since the ratio of the respective masses, η=mc2/mb2∼1/10, is not small enough. Therefore, the usual variable flavor number scheme (VFNS has to be generalized. The renormalization procedure in the two-mass case is different from the single mass case derived in [1]. We present the moments N=2,4 and 6 for all contributing operator matrix elements, expanding in the ratio η. We calculate the analytic results for general values of the Mellin variable N in the flavor non-singlet case, as well as for transversity and the matrix element Agq(3. We also calculate the two-mass scalar integrals of all topologies contributing to the gluonic operator matrix element Agg. As it turns out, the expansion in η is usually inapplicable for general values of N. We therefore derive the result for general values of the mass ratio. From the single pole terms we derive, now in a two-mass calculation, the corresponding contributions to the 3-loop anomalous dimensions. We introduce a new general class of iterated integrals and study their relations and present special values. The corresponding functions are implemented in computer-algebraic form.

Complex Masses in the S-Matrix

International Nuclear Information System (INIS)

Rupp, G.; Coito, S.; Beveren, E. van

2010-01-01

Most excited hadrons have multiparticle strong decay modes, which can often be described as resulting from intermediate states containing one or two resonances. In a theoretical approach, such a description in terms of quasi-two-particle initial and final states leads to unitarity violations, because of the complex masses of the involved resonances. In the present paper, an empirical algebraic procedure is presented to restore unitarity of the S-matrix while preserving its symmetry. Preliminary results are presented in a first application to S-wave ππ scattering, in the framework of the Resonance-Spectrum Expansion. (author)

General structure of democratic mass matrix of quark sector in E{sub 6} model

Energy Technology Data Exchange (ETDEWEB)

Ciftci, R., E-mail: rciftci@cern.ch [Ankara (Turkey); Çiftci, A. K., E-mail: abbas.kenan.ciftci@cern.ch [Ankara University, Ankara (Turkey)

2016-03-25

An extension of the Standard Model (SM) fermion sector, which is inspired by the E{sub 6} Grand Unified Theory (GUT) model, might be a good candidate to explain a number of unanswered questions in SM. Existence of the isosinglet quarks might explain great mass difference of bottom and top quarks. Also, democracy on mass matrix elements is a natural approach in SM. In this study, we have given general structure of Democratic Mass Matrix (DMM) of quark sector in E6 model.

Silver nanoparticles as matrix for laser desorption/ionization mass spectrometry of peptides

International Nuclear Information System (INIS)

Hua Lin; Chen Jianrong; Ge Liya; Tan, Swee Ngin

2007-01-01

Silver nanoparticle synthesized from chemical reduction has been successfully utilized as a matrix in matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) of peptides. Acting as a substrate to adsorb analytes, as well as a transmission medium for UV laser, silver nanoparticle was found to assist in the desorption/ionization of peptides with little or no induced fragmentation. The size of the nanoparticle was typically in the range of 160 ± 20 nm. One of the key advantages of silver nanoparticle for peptides analysis is its simple step for on-probe sample preparation. In addition, it also minimizes the interferences of sodium dodecyl sulfate (SDS) surfactant background signal, resulting in cleaner mass spectra and more sensitive signal, when compared to α-cyano-4-hydroxycinnamic acid (CCA) matrix

Study of the matrix specific mass discrimination effects during inductively coupled plasma mass spectrometry isotope ratio measurements

International Nuclear Information System (INIS)

Vassileva, E.; Quetel, Ch.R.

2004-01-01

Sample matrix related effects on mass discrimination during inductively coupled plasma mass spectrometry (ICP-MS) isotope ratio measurements have only been rarely reported. However, they can lead to errors larger than the uncertainty claimed on the ratio results when not properly taken into account or corrected for. These matrix specific affects were experienced during an Isotope Dilution Mass Spectrometry (IDMS) campaign we carried out for the certification of the Cd amount content in some food digest samples (7% acidity and salts content around 450μg g -1 ). Dilution was not possible for Cd only present at the low ng g -1 level. Up to 1% difference was observed on Cd isotope ratio results between measurements performed directly or after matrix separation. This was a significant difference considering that less than 1.5% relative combined uncertainty was eventually estimated for these IDMS measurements. Similar results could be obtained either way after the implementation of necessary corrections. The direct measurement approach associated to a correction for mass discrimination effects using the food digest sample itself (and the IUPAC table values as reference for the natural Cd isotopic composition) was preferred as it was the easiest. Consequently, the impact of matrix effects on mass discrimination during isotope ratio measurements with two types of ICP- MS (quadrupole and magnetic sector instruments) was studied for 4 elements (Li, Cu, Cd and Tl). Samples of varying salinity (up to 0.25%) and acidity (up to 7%) characteristics were prepared using isotopic certified reference materials of these elements. The long term and short-term stability, respectively reproducibility and repeatability, of the results, as well as the evolution of the difference to certified ratio values were monitored. As expected the 13 investigated isotopic ratios were all sensitive to variations in salt and acid concentrations. Our experiments also showed that simultaneous variation

Three loop massive operator matrix elements and asymptotic Wilson coefficients with two different masses

Energy Technology Data Exchange (ETDEWEB)

Ablinger, J.; Hasselhuhn, A.; Schneider, C. [Johannes Kepler Univ., Linz (Austria). Research Inst. for Symbolic Computation (RISC); Bluemlein, J.; Freitas, A. de [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Wissbrock, F. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Johannes Kepler Univ., Linz (Austria). Research Inst. for Symbolic Computation (RISC); IHES, Bures-sur-Yvette (France)

2017-05-15

Starting at 3-loop order, the massive Wilson coefficients for deep-inelastic scattering and the massive operator matrix elements describing the variable flavor number scheme receive contributions of Feynman diagrams carrying quark lines with two different masses. In the case of the charm and bottom quarks, the usual decoupling of one heavy mass at a time no longer holds, since the ratio of the respective masses, η=m{sup 2}{sub c}/m{sup 2}{sub b}∝1/10, is not small enough. Therefore, the usual variable flavor number scheme (VFNS) has to be generalized. The renormalization procedure in the two-mass case is different from the single mass case derived earlier (I. Bierenbaum, J: Bluemlein, S. Klein, 2009). We present the moments N=2,4 and 6 for all contributing operator matrix elements, expanding in the ratio η. We calculate the analytic results for general values of the Mellin variable N in the flavor non-singlet case, as well as for transversity and the matrix element A{sup (3)}{sub gq}. We also calculate the two-mass scalar integrals of all topologies contributing to the gluonic operator matrix element A{sub gg}. As it turns out, the expansion in η is usually inapplicable for general values of N. We therefore derive the result for general values of the mass ratio. From the single pole terms we derive, now in a two-mass calculation, the corresponding contributions to the 3-loop anomalous dimensions. We introduce a new general class of iterated integrals and study their relations and present special values. The corresponding functions are implemented in computer-algebraic form.

Radwaste disposal by incorporation in matrix

International Nuclear Information System (INIS)

Curtiss, D.H.; Heacock, H.W.

1976-01-01

A process of safe disposal, handling, or storae of radwaste associated with nuclear power productin is described. A feature of the invention is to incorporate the radwaste in a hardenable, matrix-forming mass employing a cement-type binding agent to which alkali or alkaline-earth silicate is added, among other things, to increase liquid absorption. 9 claims

Theory for added mass of a vibrating circular rod in a two-phase air-water fluid

International Nuclear Information System (INIS)

Kohgo, Osamu; Hara, Fumio

1985-01-01

It has been well known that there are added mass and attenuation effect due to surrounding fluid in a structure vibrating in the fluid, and those are different according to the density and viscosity of the fluid and the form of the structure. In this study, in order to clarify added mass, the model of the vapor-liquid two-phase fluid with discontinuous density distribution was made. That is, bubbles were assumed to be a bubble column without bending stiffness and mass, and potential analysis was applied to a two-dimensional fluid field composed of a round section beam and the bubble column, thus their relative motion was hydrodynamically analyzed, and the theory for evaluating added mass was developed. The added mass experimentally determined from the response gain of a single round section cantilever when it was oscillated steadily, uniformly and at random in the vapor-liquid two-phase fluid being stationary as a whole and the theoretical result were examined by comparison, and equivalent bubble diameter was considered, thereafter, the validity of the model was examined. (Kako, I.)

The matrix effect in secondary ion mass spectrometry

Science.gov (United States)

Seah, M. P.; Shard, A. G.

2018-05-01

Matrix effects in the secondary ion mass spectrometry (SIMS) of selected elemental systems have been analyzed to investigate the applicability of a mathematical description of the matrix effect, called here the charge transfer (CT) model. This model was originally derived for proton exchange and organic positive secondary ions, to characterise the enhancement or suppression of intensities in organic binary systems. In the systems considered in this paper protons are specifically excluded, which enables an assessment of whether the model applies for electrons as well. The present importance is in organic systems but, here we analyse simpler inorganic systems. Matrix effects in elemental systems cannot involve proton transfer if there are no protons present but may be caused by electron transfer and so electron transfer may also be involved in the matrix effects for organic systems. There are general similarities in both the magnitudes of the ion intensities as well as the matrix effects for both positive and negative secondary ions in both systems and so the CT model may be more widely applicable. Published SIMS analyses of binary elemental mixtures are analyzed. The data of Kim et al., for the Pt/Co system, provide, with good precision, data for such a system. This gives evidence for the applicability of the CT model, where electron, rather than proton, transfer is the matrix enhancing and suppressing mechanism. The published data of Prudon et al., for the important Si/Ge system, provides further evidence for the effects for both positive and negative secondary ions and allows rudimentary rules to be developed for the enhancing and suppressing species.

Frequency Shifts of Micro and Nano Cantilever Beam Resonators Due to Added Masses

KAUST Repository

Bouchaala, Adam M.

2016-03-21

We present analytical and numerical techniques to accurately calculate the shifts in the natural frequencies of electrically actuated micro and nano (carbon nanotubes (CNTs)) cantilever beams implemented as resonant sensors for mass detection of biological entities, particularly Escherichia coli (E. coli) and prostate specific antigen (PSA) cells. The beams are modeled as Euler-Bernoulli beams, including the nonlinear electrostatic forces and the added biological cells, which are modeled as discrete point masses. The frequency shifts due to the added masses of the cells are calculated for the fundamental and higher-order modes of vibrations. Analytical expressions of the natural frequency shifts under a direct current (DC) voltage and an added mass have been developed using perturbation techniques and the Galerkin approximation. Numerical techniques are also used to calculate the frequency shifts and compared with the analytical technique. We found that a hybrid approach that relies on the analytical perturbation expression and the Galerkin procedure for calculating accurately the static behavior presents the most computationally efficient approach. We found that using higher-order modes of vibration of micro-electro-mechanical-system (MEMS) beams or miniaturizing the sizes of the beams to nanoscale leads to significant improved frequency shifts, and thus increased sensitivities. © 2016 by ASME.

Ammonium Sulfate Improves Detection of Hydrophilic Quaternary Ammonium Compounds through Decreased Ion Suppression in Matrix-Assisted Laser Desorption/Ionization Imaging Mass Spectrometry.

Science.gov (United States)

Sugiyama, Eiji; Masaki, Noritaka; Matsushita, Shoko; Setou, Mitsutoshi

2015-11-17

Hydrophilic quaternary ammonium compounds (QACs) include derivatives of carnitine (Car) or choline, which are known to have essential bioactivities. Here we developed a technique for improving the detection of hydrophilic QACs using ammonium sulfate (AS) in matrix-assisted laser desorption/ionization-imaging mass spectrometry (MALDI-IMS). In MALDI mass spectrometry for brain homogenates, the addition of AS greatly increased the signal intensities of Car, acetylcarnitine (AcCar), and glycerophosphocholine (GPC) by approximately 300-, 700-, and 2500-fold. The marked improvement required a higher AS concentration than that needed for suppressing the potassium adduction on phosphatidylcholine and 2,5-dihydroxybenzoic acid. Adding AS also increased the signal intensities of Car, AcCar, and GPC by approximately 10-, 20-, and 40-fold in MALDI-IMS. Consequently, the distributions of five hydrophilic QACs (Car, AcCar, GPC, choline, and phosphocholine) were simultaneously visualized by this technique. The distinct mechanism from other techniques such as improved matrix application, derivatization, or postionization suggests the great potential of AS addition to achieve higher sensitivity of MALDI-IMS for various analytes.

Matrix-assisted laser-desorption-ionization mass spectrometry of proteins using a free-electron laser

International Nuclear Information System (INIS)

Cramer, R.; Hillenkamp, F.; Haglund, R.

1995-01-01

Matrix-assisted laser desorption-ionization (MALDI) mass spectrometry (MS) is one of the most promising techniques for spectral fingerprinting large molecules, such as proteins, oligonucleotides and carbohydrates. In the usual implementation of this technique, the analyte molecule is dissolved in an aromatic liquid matrix material which resonantly absorbs ultraviolet laser light. Resonant absorption by π-π* transitions volatilizes the matrix and initiates subsequent charge transfer to the analyte molecules, which are detected by time-of-flight mass spectrometry. Recent MALDI-MS studies with Er:YAG (2.94 μm) and CO 2 4 (9.4-10.6 μm) lasers suggest that them is significant unexplored potential for mass spectrometry of macromolecules, including oligonucleotide, in the mid-infrared. Preliminary experiments show that it is possible to capitalize on the rich rovibronic absorption spectrum of virtually all organics to initiate resonant desorption in matrix material over the entire range of pH values. However, the mechanism of charge transfer is particularly problematic for infrared MALDI because of the low photon energy. In this paper, we report the results of MALI-MS studies on small proteins using the Vanderbilt FEL and several matrix materials. Proteins with masses up to roughly 6,000 amu were detected with high resolution in a linear time-of-flight mass spectrometer. By varying the pulse duration using a broadband Pockels cell, we have been able to compare the results of relatively long (5 μs) and short (0.1 μs) irradiation on the desorption and ionization processes. Compared to uv-MALDI spectra of identical analytes obtained with a nitrogen laser (337 nm) in the same time-of-flight spectrometer, the infrared results appear to show that the desorption and ionization process goes on over a somewhat longer time scale

Matrix-assisted laser desorption/ionization mass spectrometry for the structural characterization of modified oligonucleotides

International Nuclear Information System (INIS)

Hurst, G.B.; Hettich, R.L.; Buchanan, M.V.; Stemmler, E.A.

1993-01-01

Matrix-assisted laser desorption ionization (MALDI) Fourier transform ion cyclotron resonance mass spectrometry (FTMS) and MALDI time-of-flight mass spectrometry (TOFMS) are being used to characterize conditions for the efficient desorption and ionization of normal and modified nucleic acid components. Basic and acidic matrix materials have been evaluated on the components. Basic and acidic matrix materials have been evaluated on the FTMS and TOFMS. Using MALDI-FTMS at 355 nm, less fragmentation has been observed using 2,5-dihydroxybenzoic acid, while more extensive fragmentation is observed for basic matrices, such as 1,5-diaminonaphthalene and 9-aminophenanthrene. Elevation of the cell pressure by the addition of Ar or CO 2 provides collisional cooling of desorbed ions, resulting in an enhancement of [M--H] - and structurally significant high-mass fragment ions. Using MALDI-TOFMS at 337 nm, fragmentation is significantly reduced relative to that observed on the FTMS, perhaps as a consequence of the longer times required for FTMS detection. On the FTMS and TOFMS, cluster ions have been observed in the negative ion mode when metal ions are present in the 2,5-dihydroxybenzoic acid matrix. Metal ion additions and clusters with matrix salts have also been observed for dinucleotides. Applications of MALDI-FTMS and MALDI-TOF to the detection of hydroxylated PAH nucleoside adducts are presented

Meson effective mass in the isospin medium in hard-wall AdS/QCD model

Energy Technology Data Exchange (ETDEWEB)

Mamedov, Shahin [Gazi University, Department of Physics, Ankara (Turkey); Baku State University, Institute for Physical Problems, Baku (Azerbaijan); Azerbaijan National Academy of Sciences, Institute of Physics, Baku (Azerbaijan)

2016-02-15

We study a mass splitting of the light vector, axial-vector, and pseudoscalar mesons in the isospin medium in the framework of the hard-wall model. We write an effective mass definition for the interacting gauge fields and scalar field introduced in gauge field theory in the bulk of AdS space-time. Relying on holographic duality we obtain a formula for the effective mass of a boundary meson in terms of derivative operator over the extra bulk coordinate. The effective mass found in this way coincides with the one obtained from finding of poles of the two-point correlation function. In order to avoid introducing distinguished infrared boundaries in the quantization formula for the different mesons from the same isotriplet we introduce extra action terms at this boundary, which reduces distinguished values of this boundary to the same value. Profile function solutions and effective mass expressions were found for the in-medium ρ, a{sub 1}, an π mesons. (orig.)

Lepton mixing matrix element U13 and new assignments of universal texture for quark and lepton mass matrices

International Nuclear Information System (INIS)

Matsuda, Koichi; Nishiura, Hiroyuki

2004-01-01

We reanalyze the mass matrix model of quarks and leptons that gives a unified description of quark and lepton mass matrices with the same texture form. By investigating possible types of assignment for the texture components of the lepton mass matrix, we find that a different assignment for neutrinos than for charged leptons can also lead to consistent values of the Maki-Nakagawa-Sakata-Pontecorv (MNSP) lepton mixing matrix. We also find that the predicted value for the lepton mixing matrix element U 13 of the model depends on the assignment. A proper assignment will be discriminated by future experimental data for U 13

Identification of Enterobacteriaceae by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry using the VITEK MS system.

Science.gov (United States)

Richter, S S; Sercia, L; Branda, J A; Burnham, C-A D; Bythrow, M; Ferraro, M J; Garner, O B; Ginocchio, C C; Jennemann, R; Lewinski, M A; Manji, R; Mochon, A B; Rychert, J A; Westblade, L F; Procop, G W

2013-12-01

This multicenter study evaluated the accuracy of matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry identifications from the VITEK MS system (bioMérieux, Marcy l'Etoile, France) for Enterobacteriaceae typically encountered in the clinical laboratory. Enterobacteriaceae isolates (n = 965) representing 17 genera and 40 species were analyzed on the VITEK MS system (database v2.0), in accordance with the manufacturer's instructions. Colony growth (≤72 h) was applied directly to the target slide. Matrix solution (α-cyano-4-hydroxycinnamic acid) was added and allowed to dry before mass spectrometry analysis. On the basis of the confidence level, the VITEK MS system provided a species, genus only, or no identification for each isolate. The accuracy of the mass spectrometric identification was compared to 16S rRNA gene sequencing performed at MIDI Labs (Newark, DE). Supplemental phenotypic testing was performed at bioMérieux when necessary. The VITEK MS result agreed with the reference method identification for 96.7% of the 965 isolates tested, with 83.8% correct to the species level and 12.8% limited to a genus-level identification. There was no identification for 1.7% of the isolates. The VITEK MS system misidentified 7 isolates (0.7 %) as different genera. Three Pantoea agglomerans isolates were misidentified as Enterobacter spp. and single isolates of Enterobacter cancerogenus, Escherichia hermannii, Hafnia alvei, and Raoultella ornithinolytica were misidentified as Klebsiella oxytoca, Citrobacter koseri, Obesumbacterium proteus, and Enterobacter aerogenes, respectively. Eight isolates (0.8 %) were misidentified as a different species in the correct genus. The VITEK MS system provides reliable mass spectrometric identifications for Enterobacteriaceae.

The two-mass contribution to the three-loop pure singlet operator matrix element

Energy Technology Data Exchange (ETDEWEB)

Ablinger, J.; Schneider, C. [Johannes Kepler Univ., Linz (Austria). Research Inst. for Symbolic Computation (RISC); Bluemlein, J.; Freitas, A. de; Schoenwald, K. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany)

2017-11-15

We present the two-mass QCD contributions to the pure singlet operator matrix element at three loop order in x-space. These terms are relevant for calculating the structure function F{sub 2}(x,Q{sup 2}) at O(α{sup 3}{sub s}) as well as for the matching relations in the variable flavor number scheme and the heavy quark distribution functions at the same order. The result for the operator matrix element is given in terms of generalized iterated integrals that include square root letters in the alphabet, depending also on the mass ratio through the main argument. Numerical results are presented.

Quantitative analysis of polyhexamethylene guanidine (PHMG) oligomers via matrix-assisted laser desorption/ionization time-of-flight mass spectrometry with an ionic-liquid matrix.

Science.gov (United States)

Yoon, Donhee; Lee, Dongkun; Lee, Jong-Hyeon; Cha, Sangwon; Oh, Han Bin

2015-01-30

Quantifying polymers by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS) with a conventional crystalline matrix generally suffers from poor sample-to-sample or shot-to-shot reproducibility. An ionic-liquid matrix has been demonstrated to mitigate these reproducibility issues by providing a homogeneous sample surface, which is useful for quantifying polymers. In the present study, we evaluated the use of an ionic liquid matrix, i.e., 1-methylimidazolium α-cyano-4-hydroxycinnamate (1-MeIm-CHCA), to quantify polyhexamethylene guanidine (PHMG) samples that impose a critical health hazard when inhaled in the form of droplets. MALDI-TOF mass spectra were acquired for PHMG oligomers using a variety of ionic-liquid matrices including 1-MeIm-CHCA. Calibration curves were constructed by plotting the sum of the PHMG oligomer peak areas versus PHMG sample concentration with a variety of peptide internal standards. Compared with the conventional crystalline matrix, the 1-MeIm-CHCA ionic-liquid matrix had much better reproducibility (lower standard deviations). Furthermore, by using an internal peptide standard, good linear calibration plots could be obtained over a range of PMHG concentrations of at least 4 orders of magnitude. This study successfully demonstrated that PHMG samples can be quantitatively characterized by MALDI-TOFMS with an ionic-liquid matrix and an internal standard. Copyright © 2014 John Wiley & Sons, Ltd.

Calibration of matrix-assisted laser desorption/ionization time-of-flight peptide mass fingerprinting spectra

DEFF Research Database (Denmark)

Hjernø, Karin; Højrup, Peter

2007-01-01

This chapter describes a number of aspects important for calibration of matrix-assisted laser desorption/ionization time-of-flight spectra prior to peptide mass fingerprinting searches. Both multipoint internal calibration and mass defect-based calibration is illustrated. The chapter describes ho...

A note on physical mass and the thermodynamics of AdS-Kerr black holes

Energy Technology Data Exchange (ETDEWEB)

McInnes, Brett [Department of Mathematics, National University of Singapore, 10, Lower Kent Ridge Road, 119076 (Singapore); Ong, Yen Chin, E-mail: matmcinn@nus.edu.sg, E-mail: yenchin.ong@nordita.org [Nordic Institute for Theoretical Physics, KTH Royal Institute of Technology Stockholm University, Roslagstullsbacken 23, SE-106 91 Stockholm (Sweden)

2015-11-01

As with any black hole, asymptotically anti-de Sitter Kerr black holes are described by a small number of parameters, including a ''mass parameter'' M that reduces to the AdS-Schwarzschild mass in the limit of vanishing angular momentum. In sharp contrast to the asymptotically flat case, the horizon area of such a black hole increases with the angular momentum parameter a if one fixes M; this appears to mean that the Penrose process in this case would violate the Second Law of black hole thermodynamics. We show that the correct procedure is to fix not M but rather the ''physical'' mass E=M/(1−a{sup 2}/L{sup 2}){sup 2}; this is motivated by the First Law. For then the horizon area decreases with a. We recommend that E always be used as the mass in physical processes: for example, in attempts to ''over-spin'' AdS-Kerr black holes.

Alterations in the nuclear matrix protein mass correlate with heat-induced inhibition of DNA single-strand-break repair

International Nuclear Information System (INIS)

Warters, R.L.; Brizgys, L.M.; Lyons, B.W.

1987-01-01

The total protein mass co-isolating with the nuclear matrix or nucleoid from Chinese hamster ovary (CHO) cells was observed to increase in heated cells as a function of increasing exposure temperature between 43 0 C and 45 0 C or of exposure time at any temperature. The sedimentation distance of the CHO cell nucleoid in sucrose gradients increased with increasing exposure time at 45 0 C. Both these nuclear alterations correlated in a log-linear manner with heat-induced inhibition of DNA strand break repair. A two-fold threshold increase in nuclear matrix protein mass preceded any substantial inhibition of repair of DNA single-strand breaks. When preheated cells were incubated at 37 0 C the nuclear matrix protein mass and nucleoid sedimentation recovered with a half-time of about 5 h, while DNA single-strand-break repair recovered with a half-time of about 2 h. When preheated cells were placed at 41 0 C a further increase was observed in the nuclear matrix protein mass and the half-time of DNA strand break repair, while nucleoid sedimentation recovered toward control values. These results implicate alterations in the protein mass of the nuclear matrix in heat-induced inhibition of repair of DNA single-strand breaks. (author)

Exploring AdS waves via nonminimal coupling

International Nuclear Information System (INIS)

Ayon-Beato, Eloy; Hassaiene, Mokhtar

2006-01-01

We consider nonminimally coupled scalar fields to explore the Siklos spacetimes in three dimensions. Their interpretation as exact gravitational waves propagating on AdS space restrict the source to behave as a pure radiation field. We show that the related pure radiation constraints single out a unique self-interaction potential depending on one coupling constant. For a vanishing coupling constant, this potential reduces to a mass term with a mass fixed in terms of the nonminimal-coupling parameter. This mass dependence allows the existence of several free cases including massless and tachyonic sources. There even exists a particular value of the nonminimal-coupling parameter for which the corresponding mass exactly compensates the contribution generated by the negative scalar curvature, producing a genuinely massless field in this curved background. The self-interacting case is studied in detail for the conformal coupling. The resulting gravitational wave is formed by the superposition of the free and the self-interaction contributions, except for a critical value of the coupling constant where a nonperturbative effect relating the strong and weak regimes of the source appears. We establish a correspondence between the scalar source supporting an AdS wave and a pp wave by showing that their respective pure radiation constraints are conformally related, while their involved backgrounds are not. Finally, we consider the AdS waves for topologically massive gravity and its limit to conformal gravity

Baby Skyrmions in AdS

Energy Technology Data Exchange (ETDEWEB)

Elliot-Ripley, Matthew; Winyard, Thomas [Department of Mathematical Sciences, Durham University,South Rd, Durham (United Kingdom)

2015-09-01

We study the baby Skyrme model in a pure AdS background without a mass term. The tail decays and scalings of massless radial solutions are demonstrated to take a similar form to those of the massive flat space model, with the AdS curvature playing a similar role to the flat space pion mass. We also numerically find minimal energy solutions for a range of higher topological charges and find that they form concentric ring-like solutions. Popcorn transitions (named in analogy with studies of toy models of holographic QCD) from an n layer to an n+1-layer configuration are observed at topological charges 9 and 27 and further popcorn transitions for higher charges are predicted. Finally, a point-particle approximation for the model is derived and used to successfully predict the ring structures and popcorn transitions for higher charge solitons.

1,8-Bis(dimethylamino)naphthalene/9-aminoacridine: A new binary matrix for lipid fingerprinting of intact bacteria by matrix assisted laser desorption ionization mass spectrometry

Energy Technology Data Exchange (ETDEWEB)

Calvano, C.D., E-mail: cosimadamiana.calvano@uniba.it [Dipartimento di Chimica, Università degli Studi di Bari Aldo Moro, Via Orabona, 4, 70126 Bari (Italy); Monopoli, A.; Ditaranto, N. [Dipartimento di Chimica, Università degli Studi di Bari Aldo Moro, Via Orabona, 4, 70126 Bari (Italy); Palmisano, F. [Dipartimento di Chimica, Università degli Studi di Bari Aldo Moro, Via Orabona, 4, 70126 Bari (Italy); Centro Interdipartimentale di Ricerca S.M.A.R.T., Università degli Studi di Bari Aldo Moro, Via Orabona, 4, 70126 Bari (Italy)

2013-10-10

Graphical abstract: -- Highlights: •New binary matrix for less ionizable lipid analysis with no interfering peaks. •Combined MALDI and X-ray photoelectron spectroscopy (XPS) analyses. •Fast lipid fingerprint on Gram positive and Gram negative bacteria by MALDI MS. •Mapping of phospholipids by XPS imaging. •Very fast membrane lipid extraction procedure. -- Abstract: The effectiveness of a novel binary matrix composed of 1,8-bis(dimethylamino)naphthalene (DMAN; proton sponge) and 9-aminoacridine (9AA) for the direct lipid analysis of whole bacterial cells by matrix assisted laser desorption ionization mass spectrometry (MALDI MS) is demonstrated. Deprotonated analyte signals nearly free of matrix-related ions were observed in negative ion mode. The effect of the most important factors (laser energy, pulse voltage, DMAN/9AA ratio, analyte/matrix ratio) was investigated using a Box–Behnken response surface design followed by multi-response optimization in order to simultaneously maximize signal-to-noise (S/N) ratio and resolution. The chemical surface composition of single or mixed matrices was explored by X-ray photoelectron spectroscopy (XPS). Moreover, XPS imaging was used to map the spatial distribution of a model phospholipid in single or binary matrices. The DMAN/9AA binary matrix was then successfully applied to the analysis of intact Gram positive (Lactobacillus sanfranciscensis) or Gram negative (Escherichia coli) microorganisms. About fifty major membrane components (free fatty acids, mono-, di- and tri-glycerides, phospholipids, glycolipids and cardiolipins) were quickly and easily detected over a mass range spanning from ca. 200 to ca. 1600 m/z. Moreover, mass spectra with improved S/N ratio (compared to single matrices), reduced chemical noise and no formation of matrix-clusters were invariably obtained demonstrating the potential of this binary matrix to improve sensitivity.

1,8-Bis(dimethylamino)naphthalene/9-aminoacridine: A new binary matrix for lipid fingerprinting of intact bacteria by matrix assisted laser desorption ionization mass spectrometry

International Nuclear Information System (INIS)

Calvano, C.D.; Monopoli, A.; Ditaranto, N.; Palmisano, F.

2013-01-01

Graphical abstract: -- Highlights: •New binary matrix for less ionizable lipid analysis with no interfering peaks. •Combined MALDI and X-ray photoelectron spectroscopy (XPS) analyses. •Fast lipid fingerprint on Gram positive and Gram negative bacteria by MALDI MS. •Mapping of phospholipids by XPS imaging. •Very fast membrane lipid extraction procedure. -- Abstract: The effectiveness of a novel binary matrix composed of 1,8-bis(dimethylamino)naphthalene (DMAN; proton sponge) and 9-aminoacridine (9AA) for the direct lipid analysis of whole bacterial cells by matrix assisted laser desorption ionization mass spectrometry (MALDI MS) is demonstrated. Deprotonated analyte signals nearly free of matrix-related ions were observed in negative ion mode. The effect of the most important factors (laser energy, pulse voltage, DMAN/9AA ratio, analyte/matrix ratio) was investigated using a Box–Behnken response surface design followed by multi-response optimization in order to simultaneously maximize signal-to-noise (S/N) ratio and resolution. The chemical surface composition of single or mixed matrices was explored by X-ray photoelectron spectroscopy (XPS). Moreover, XPS imaging was used to map the spatial distribution of a model phospholipid in single or binary matrices. The DMAN/9AA binary matrix was then successfully applied to the analysis of intact Gram positive (Lactobacillus sanfranciscensis) or Gram negative (Escherichia coli) microorganisms. About fifty major membrane components (free fatty acids, mono-, di- and tri-glycerides, phospholipids, glycolipids and cardiolipins) were quickly and easily detected over a mass range spanning from ca. 200 to ca. 1600 m/z. Moreover, mass spectra with improved S/N ratio (compared to single matrices), reduced chemical noise and no formation of matrix-clusters were invariably obtained demonstrating the potential of this binary matrix to improve sensitivity

Connecting Majorana phases to the geometric parameters of the Majorana unitarity triangle in a neutrino mass matrix model

Science.gov (United States)

Verma, Surender; Bhardwaj, Shankita

2018-05-01

We have investigated a possible connection between the Majorana phases and geometric parameters of Majorana unitarity triangle (MT) in two-texture zero neutrino mass matrix. Such analytical relations can, also, be obtained for other theoretical models viz. hybrid textures, neutrino mass matrix with vanishing minors and have profound implications for geometric description of C P violation. As an example, we have considered the two-texture zero neutrino mass model to obtain a relation between Majorana phases and MT parameters that may be probed in various lepton number violating processes. In particular, we find that Majorana phases depend on only one of the three interior angles of the MT in each class of two-texture zero neutrino mass matrix. We have also constructed the MT for class A , B , and C neutrino mass matrices. Nonvanishing areas and nontrivial orientations of these Majorana unitarity triangles indicate nonzero C P violation as a generic feature of this class of mass models.

Neutrino mass from laboratory: contribution of double beta decay to the neutrino mass matrix

International Nuclear Information System (INIS)

Klapdor-Kleingrothaus, H.V.

2001-01-01

Double beta decay is indispensable to solve the question of the neutrino mass matrix together with ν oscillation experiments. The most sensitive experiment - since eight years the HEIDELBERG-MOSCOW experiment in Gran-Sasso - already now, with the experimental limit of ν > < 0.26 eV practically excludes degenerate ν mass scenarios allowing neutrinos as hot dark matter in the universe for the smallangle MSW solution of the solar neutrino problem. It probes cosmological models including hot dark matter already now on the level of future satellite experiments MAP and PLANCK. It further probes many topics of beyond SM physics at the TeV scale. Future experiments should give access to the multi-TeV range and complement on many ways the search for new physics at future colliders like LHC and NLC. For neutrino physics some of them (GENIUS) will allow to test almost all neutrino mass scenarios allowed by the present neutrino oscillation experiments

Mesoporous tungsten titanate as matrix for matrix-assisted laser desorption/ionization time-of-flight mass spectrometry analysis of biomolecules

International Nuclear Information System (INIS)

Shan Zhe; Han Lu; Yuan Minjia; Deng Chunhui; Zhao Dongyuan; Tu Bo; Yang Pengyuan

2007-01-01

In this paper, mesoporous tungsten titanate (WTiO) with different nano-pore structures was utilized as matrix for the analysis of short peptides by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS). Effect of characteristic features of mesoporous matrices on laser desorption/ionization process was investigated. Experiments showed that the ordered two-dimensional and three-dimensional mesoporous matrices were superior in performance to the non-ordered WTiO matrix. The dramatic enhancement of signal sensitivity by the ordered mesoporous matrices can be reasonably attributed to the ordered structure, which facilitated the understanding on structure-function relationship in mesoporous cavity for laser desorption process of adsorbed biomolecules. With the ordered mesoporous matrix, the short peptides are successfully detected. The presence of trace alkali metal salt effectively increased the analyte ion yields and the MALDI-TOFMS using the inorganic mesoporous matrices displayed a high salt tolerance. The developed technique also showed a satisfactory performance in peptide-mapping and amino-acid sequencing analysis

Scaling Mode Shapes in Output-Only Structure by a Mass-Change-Based Method

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Liangliang Yu

2017-01-01

Full Text Available A mass-change-based method based on output-only data for the rescaling of mode shapes in operational modal analysis (OMA is introduced. The mass distribution matrix, which is defined as a diagonal matrix whose diagonal elements represent the ratios among the diagonal elements of the mass matrix, is calculated using the unscaled mode shapes. Based on the theory of null space, the mass distribution vector or mass distribution matrix is obtained. A small mass with calibrated weight is added to a certain location of the structure, and then the mass distribution vector of the modified structure is estimated. The mass matrix is identified according to the difference of the mass distribution vectors between the original and modified structures. Additionally, the universal set of modes is unnecessary when calculating the mass distribution matrix, indicating that modal truncation is allowed in the proposed method. The mass-scaled mode shapes estimated in OMA according to the proposed method are compared with those obtained by experimental modal analysis. A simulation is employed to validate the feasibility of the method. Finally, the method is tested on output-only data from an experiment on a five-storey structure, and the results confirm the effectiveness of the method.

The mass spectrum of the Schwinger model with matrix product states

Energy Technology Data Exchange (ETDEWEB)

Banuls, M.C.; Cirac, J.I. [Max-Planck-Institut fuer Quantenoptik (MPQ), Garching (Germany); Cichy, K. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Poznan Univ. (Poland). Faculty of Physics; Jansen, K. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Cyprus Univ., Nicosia (Cyprus). Dept. of Physics

2013-07-15

We show the feasibility of tensor network solutions for lattice gauge theories in Hamiltonian formulation by applying matrix product states algorithms to the Schwinger model with zero and non-vanishing fermion mass. We introduce new techniques to compute excitations in a system with open boundary conditions, and to identify the states corresponding to low momentum and different quantum numbers in the continuum. For the ground state and both the vector and scalar mass gaps in the massive case, the MPS technique attains precisions comparable to the best results available from other techniques.

Theory of quark mixing matrix and invariant functions of mass matrices

International Nuclear Information System (INIS)

Jarlskog, C.

1987-10-01

The outline of this talk is as follows: The origin of the quark mixing matrix. Super elementary theory of flavour projection operators. Equivalences and invariances. The commutator formalism and CP violation. CP conditions for any number of families. The 'angle' between the quark mass matrices. Application to Fritzsch and Stech matrices. References. (author)

Puzzles of η-deformed AdS_5×S"5

International Nuclear Information System (INIS)

Arutyunov, Gleb; Borsato, Riccardo; Frolov, Sergey

2015-01-01

We derive the part of the Lagrangian for the sigma model on the η-deformed AdS_5×S"5 space which is quadratic in fermions and has the full dependence on bosons. We then show that there exists a field redefinition which brings the corresponding Lagrangian to the standard form of type IIB Green-Schwarz superstring. Reading off the corresponding RR couplings, we observe that they fail to satisfy the supergravity equations of motion, despite the presence of κ-symmetry. However, in a special scaling limit our solution reproduces the supergravity background found by Maldacena and Russo. Further, using the fermionic Lagrangian, we compute a number of new matrix elements of the tree level world-sheet scattering matrix. We then show that after a unitary transformation on the basis of two-particle states which is not one-particle factorisable, the corresponding T-matrix factorises into two equivalent parts. Each part satisfies the classical Yang-Baxter equation and coincides with the large tension limit of the q-deformed S-matrix.

Feasibility study of a wearable exoskeleton for children: is the gait altered by adding masses on lower limbs?

Directory of Open Access Journals (Sweden)

Stefano Rossi

Full Text Available We are designing a pediatric exoskeletal ankle robot (pediatric Anklebot to promote gait habilitation in children with Cerebral Palsy (CP. Few studies have evaluated how much or whether the unilateral loading of a wearable exoskeleton may have the unwanted effect of altering significantly the gait. The purpose of this study was to evaluate whether adding masses up to 2.5 kg, the estimated overall added mass of the mentioned device, at the knee level alters the gait kinematics. Ten healthy children and eight children with CP, with light or mild gait impairment, walked wearing a knee brace with several masses. Gait parameters and lower-limb joint kinematics were analyzed with an optoelectronic system under six conditions: without brace (natural gait and with masses placed at the knee level (0.5, 1.0, 1.5, 2.0, 2.5 kg. T-tests and repeated measures ANOVA tests were conducted in order to find noteworthy differences among the trial conditions and between loaded and unloaded legs. No statistically significant differences in gait parameters for both healthy children and children with CP were observed in the five "with added mass" conditions. We found significant differences among "natural gait" and "with added masses" conditions in knee flexion and hip extension angles for healthy children and in knee flexion angle for children with CP. This result can be interpreted as an effect of the mechanical constraint induced by the knee brace rather than the effect associated with load increase. The study demonstrates that the mechanical constraint induced by the brace has a measurable effect on the gait of healthy children and children with CP and that the added mass up to 2.5 kg does not alter the lower limb kinematics. This suggests that wearable devices weighing 25 N or less will not noticeably modify the gait patterns of the population examined here.

Neutrino oscillation observables from mass matrix structure

International Nuclear Information System (INIS)

Winter, Walter

2008-01-01

We present a systematic procedure to establish a connection between complex neutrino mass matrix textures and experimental observables, including the Dirac CP phase. In addition, we illustrate how future experimental measurements affect the selection of textures in the (θ 13 ,δ CP )-plane. For the mixing angles, we use generic assumptions motivated by quark-lepton complementarity. We allow for any combination between U l and U ν , as well as we average over all present complex phases. We find that individual textures lead to very different distributions of the observables, such as to large or small leptonic CP violation. In addition, we find that the extended quark-lepton complementarity approach motivates future precision measurements of δ CP at the level of θ C ≅11 deg

Microstructure, Friction and Wear of Aluminum Matrix Composites

Science.gov (United States)

Florea, R. M.

2018-06-01

MMCs are made by dispersing a reinforcing material into a metal matrix. They are prepared by casting, although several technical challenges exist with casting technology. Achieving a homogeneous distribution of reinforcement within the matrix is one such challenge, and this affects directly on the properties and quality of composite. The aluminum alloy composite materials consist of high strength, high stiffness, more thermal stability, more corrosion and wear resistance, and more fatigue life. Aluminum alloy materials found to be the best alternative with its unique capacity of designing the materials to give required properties. In this work a composite is developed by adding silicon carbide in Aluminum metal matrix by mass ratio 5%, 10% and 15%. Mechanical tests such as hardness test and microstructure test are conducted.

Inverse mass matrix via the method of localized lagrange multipliers

Czech Academy of Sciences Publication Activity Database

González, José A.; Kolman, Radek; Cho, S.S.; Felippa, C.A.; Park, K.C.

2018-01-01

Roč. 113, č. 2 (2018), s. 277-295 ISSN 0029-5981 R&D Projects: GA MŠk(CZ) EF15_003/0000493; GA ČR GA17-22615S Institutional support: RVO:61388998 Keywords : explicit time integration * inverse mass matrix * localized Lagrange multipliers * partitioned analysis Subject RIV: BI - Acoustics OBOR OECD: Applied mechanics Impact factor: 2.162, year: 2016 https://onlinelibrary.wiley.com/doi/10.1002/nme.5613

Generation of CsI cluster ions for mass calibration in matrix-assisted laser desorption/ionization mass spectrometry

NARCIS (Netherlands)

Lou, X.; Dongen, van J.L.J.; Meijer, E.W.

2010-01-01

A simple method was developed for the generation of cesium iodide (CsI) cluster ions up to m/z over 20,000 in matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS). Calibration ions in both positive and negative ion modes can readily be generated from a single MALDI spot of CsI(3)

Identification of Fatty Acids, Phospholipids, and Their Oxidation Products Using Matrix-Assisted Laser Desorption Ionization Mass Spectrometry and Electrospray Ionization Mass Spectrometry

Science.gov (United States)

Harmon, Christopher W.; Mang, Stephen A.; Greaves, John; Finlayson-Pitts, Barbara J.

2010-01-01

Electrospray ionization mass spectrometry (ESI-MS) and matrix-assisted laser desorption ionization mass spectrometry (MALDI-MS) have found increasing application in the analysis of biological samples. Using these techniques to solve problems in analytical chemistry should be an essential component of the training of undergraduate chemists. We…

Diagonalization of quark mass matrices and the Cabibbo-Kobayashi-Maskawa matrix

International Nuclear Information System (INIS)

Rasin, A.

1997-08-01

I discuss some general aspect of diagonalizing the quark mass matrices and list all possible parametrizations of the Cabibbo-Kobayashi-Maskawa matrix (CKM) in terms of three rotation angles and a phase. I systematically study the relation between the rotations needed to diagonalize the Yukawa matrices and various parametrizations of the CKM. (author). 17 refs, 1 tab

A Lie-Theoretic Perspective on O(n) Mass Matrix Inversion for Serial Manipulators and Polypeptide Chains.

Science.gov (United States)

Lee, Kiju; Wang, Yunfeng; Chirikjian, Gregory S

2007-11-01

Over the past several decades a number of O(n) methods for forward and inverse dynamics computations have been developed in the multi-body dynamics and robotics literature. A method was developed in 1974 by Fixman for O(n) computation of the mass-matrix determinant for a serial polymer chain consisting of point masses. In other recent papers, we extended this method in order to compute the inverse of the mass matrix for serial chains consisting of point masses. In the present paper, we extend these ideas further and address the case of serial chains composed of rigid-bodies. This requires the use of relatively deep mathematics associated with the rotation group, SO(3), and the special Euclidean group, SE(3), and specifically, it requires that one differentiates functions of Lie-group-valued argument.

Matrix-assisted laser-desorption/ionization mass spectrometric imaging of olanzapine in a single hair using esculetin as a matrix.

Science.gov (United States)

Wang, Hang; Wang, Ying; Wang, Ge; Hong, Lizhi

2017-07-15

Matrix-assisted laser desorption/ionization-mass spectrometric imaging (MALDI-MSI) for the analysis of intact hair is a powerful tool for monitoring changes in drug consumption. The embedding of a low drug concentration in the hydrophobic hair matrix makes it difficult to extract and detect, and requires an improved method to increase detection sensitivity. In this study, an MSI method using MALDI-Fourier transform ion cyclotron resonance was developed for direct identification and imaging of olanzapine in hair samples using the positive ion mode. Following decontamination, scalp hair samples from an olanzapine user were scraped from the proximal to the distal end three times, and 5mm hair sections were fixed onto an Indium-Tin-Oxide (ITO)-coated microscopic glass slide. Esculetin (6,7-dihydroxy-2H-chromen-2-one) was used as a new hydrophobic matrix to increase the affinity, extraction and ionization efficiency of olanzapine in the hair samples. The spatial distribution of olanzapine was observed using five single hairs from the same drug user. This matrix improves the affinity of olanzapine in hair for molecular imaging with mass spectrometry. This method may provide a detection power for olanzapine to the nanogram level per 5mm hair. Time course changes in the MSI results were also compared with quantitative HPLC-MS/MS for each 5mm segment of single hair shafts selected from the MALDI target. MALDI imaging intensities in single hairs showed good semi-quantitative correlation with the results from conventional HPLC-MS/MS. MALDI-MSI is suitable for monitoring drug intake with a high time resolution. Copyright © 2017 Elsevier B.V. All rights reserved.

Automated MALDI Matrix Coating System for Multiple Tissue Samples for Imaging Mass Spectrometry

Science.gov (United States)

Mounfield, William P.; Garrett, Timothy J.

2012-03-01

Uniform matrix deposition on tissue samples for matrix-assisted laser desorption/ionization (MALDI) is key for reproducible analyte ion signals. Current methods often result in nonhomogenous matrix deposition, and take time and effort to produce acceptable ion signals. Here we describe a fully-automated method for matrix deposition using an enclosed spray chamber and spray nozzle for matrix solution delivery. A commercial air-atomizing spray nozzle was modified and combined with solenoid controlled valves and a Programmable Logic Controller (PLC) to control and deliver the matrix solution. A spray chamber was employed to contain the nozzle, sample, and atomized matrix solution stream, and to prevent any interference from outside conditions as well as allow complete control of the sample environment. A gravity cup was filled with MALDI matrix solutions, including DHB in chloroform/methanol (50:50) at concentrations up to 60 mg/mL. Various samples (including rat brain tissue sections) were prepared using two deposition methods (spray chamber, inkjet). A linear ion trap equipped with an intermediate-pressure MALDI source was used for analyses. Optical microscopic examination showed a uniform coating of matrix crystals across the sample. Overall, the mass spectral images gathered from tissues coated using the spray chamber system were of better quality and more reproducible than from tissue specimens prepared by the inkjet deposition method.

Instantons from geodesics in AdS moduli spaces

Science.gov (United States)

Ruggeri, Daniele; Trigiante, Mario; Van Riet, Thomas

2018-03-01

We investigate supergravity instantons in Euclidean AdS5 × S5/ℤk. These solutions are expected to be dual to instantons of N = 2 quiver gauge theories. On the supergravity side the (extremal) instanton solutions are neatly described by the (lightlike) geodesics on the AdS moduli space for which we find the explicit expression and compute the on-shell actions in terms of the quantised charges. The lightlike geodesics fall into two categories depending on the degree of nilpotency of the Noether charge matrix carried by the geodesic: for degree 2 the instantons preserve 8 supercharges and for degree 3 they are non-SUSY. We expect that these findings should apply to more general situations in the sense that there is a map between geodesics on moduli-spaces of Euclidean AdS vacua and instantons with holographic counterparts.

Texture one zero Dirac neutrino mass matrix with vanishing determinant or trace condition

Science.gov (United States)

Singh, Madan

2018-06-01

In the light of non-zero and relatively large value of rector mixing angle (θ13), we have performed a detailed analysis of texture one zero neutrino mass matrix Mν in the scenario of vanishing determinant/trace conditions, assuming the Dirac nature of neutrinos. In both the scenarios, normal mass ordering is ruled out for all the six possibilities of Mν, however for inverted mass ordering, only two are found to be viable with the current neutrino oscillation data at 3σ confidence level. Numerical and some approximate analytical results are presented.

Using matrix peaks to map topography: Increased mass resolution and enhanced sensitivity in chemical imaging

NARCIS (Netherlands)

McDonnell, Liam A.; Mize, Todd H.; Luxembourg, Stefan L.; Koster, Sander; Eijkel, Gert B.; Verpoorte, Elisabeth; De Rooij, Nico F.; Heeren, Ron M. A.

2003-01-01

It is well known in secondary ion mass spectrometry (SIMS) that sample topography leads to decreased mass resolution. Specifically, the ion's time of flight is dependent on where it was generated. Here, using matrix-enhanced SIMS, it is demonstrated that, in addition to increasing the yield of

Foundations of the AdS5 x S5 superstring: I

International Nuclear Information System (INIS)

Arutyunov, Gleb; Frolov, Sergey

2009-01-01

We review the recent advances towards finding the spectrum of the AdS 5 x S 5 superstring. We thoroughly explain the theoretical techniques which should be useful for the ultimate solution of the spectral problem. In certain cases our exposition is original and cannot be found in the existing literature. The present part I deals with foundations of classical string theory in AdS 5 x S 5 , light-cone perturbative quantization and the derivation of the exact light-cone world-sheet scattering matrix

arXiv The S-matrix Bootstrap II: Two Dimensional Amplitudes

CERN Document Server

Paulos, Miguel F.; Toledo, Jonathan; van Rees, Balt C.; Vieira, Pedro

2017-11-22

We consider constraints on the S-matrix of any gapped, Lorentz invariant quantum field theory in 1 + 1 dimensions due to crossing symmetry and unitarity. In this way we establish rigorous bounds on the cubic couplings of a given theory with a fixed mass spectrum. In special cases we identify interesting integrable theories saturating these bounds. Our analytic bounds match precisely with numerical bounds obtained in a companion paper where we consider massive QFT in an AdS box and study boundary correlators using the technology of the conformal bootstrap.

Characterisation of bacteria by matrix-assisted laser desorption/ionisation and electrospray mass spectrometry

NARCIS (Netherlands)

Baar, B.L.M. van

2000-01-01

Chemical analysis for the characterisation of micro-organisms is rapidly evolving, after the recent advent of new ionisation methods in mass spectrometry (MS): electrospray (ES) and matrix-assisted laser desorption/ionisation (MALDI). These methods allow quick characterisation of micro-organisms,

Effects of Added Mass and Structural Damping on Dynamic Responses of a 3D Wedge Impacting on Water

Directory of Open Access Journals (Sweden)

Pengyao Yu

2018-05-01

Full Text Available The impact between the wave and the bottom of a high-speed vessel is often simplified as water-entry problems of wedges. Most investigations focus on the water entry of two dimensional (2D wedges. The effects of added mass and structural damping are still not fully investigated. By combining the normal mode method, the hydrodynamic impact model of rigid wedges and the potential flow theory, a dynamic model for predicting the response of a three dimensional (3D wedge impacting on water with a constant velocity is established in this paper. The present model can selectively consider the effects of the added mass and the structural damping. The present method has been validated through comparisons with results of published literatures and commercial software. It is found that the added mass can increase the stress response before the flow separation, and reduce the vibration frequency after the flow separation. Due to the effect of the added mass, the stress response of some positions after the flow separation is even higher than that before the flow separation. The structural damping has a negligible effect on the stress before the flow separation, but it can reduce vibration stress after the flow separation.

Finite-size effect of η-deformed AdS5×S5 at strong coupling

Directory of Open Access Journals (Sweden)

Changrim Ahn

2017-04-01

Full Text Available We compute Lüscher corrections for a giant magnon in the η-deformed (AdS5×S5η using the su(2|2q-invariant S-matrix at strong coupling and compare with the finite-size effect of the corresponding string state, derived previously. We find that these two results match and confirm that the su(2|2q-invariant S-matrix is describing world-sheet excitations of the η-deformed background.

Analytical study of the frequency shifts of micro and nano clamped–clamped beam resonators due to an added mass

KAUST Repository

Bouchaala, Adam M.

2016-03-18

We present analytical formulations to calculate the induced resonance frequency shifts of electrically actuated clamped–clamped micro and nano (Carbon nanotube) beams due to an added mass. Based on the Euler–Bernoulli beam theory, we investigate the linear dynamic responses of the beams added masses, which are modeled as discrete point masses. Analytical expressions based on perturbation techniques and a one-mode Galerkin approximation are developed to calculate accurately the frequency shifts under a DC voltage as a function of the added mass and position. The analytical results are compared to numerical solution of the eigenvalue problem. Results are shown for the fundamental as well as the higher-order modes of the beams. The results indicate a significant increase in the frequency shift, and hence the sensitivity of detection, when scaling down to nano scale and using higher-order modes. © 2016 Springer Science+Business Media Dordrecht

Matrix-assisted ultraviolet laser desorption/ionization time-of-flight mass spectrometry of beta-(1 --> 3), beta-(1 --> 4)-xylans from Nothogenia fastigiata using nor-harmane as matrix.

Science.gov (United States)

Fukuyama, Yuko; Kolender, Adriana A; Nishioka, Masae; Nonami, Hiroshi; Matulewicz, María C; Erra-Balsells, Rosa; Cerezo, Alberto S

2005-01-01

Three xylan fractions isolated from the red seaweed Nothogenia fastigiata (Nemaliales) were analyzed by ultraviolet matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (UV-MALDI-TOFMS). UV-MALDI-TOFMS was carried out in the linear and reflectron modes, and as routine in the positive and negative ion modes. Of the several matrices tested, nor-harmane was the only effective one giving good spectra in the positive ion mode. The number-average molar masses of two of the fractions, calculated from the distribution profiles, were lower than those determined previously by (1)H NMR analysis, suggesting a decrease in the ionization efficiency with increasing molecular weight; weight-average molar mass and polydispersity index were also determined. As the xylans retained small but significant quantities of calcium salts, the influence of added Ca(2+) as CaCl(2) on UV-MALDI-MS was investigated. The simultaneous addition of sodium chloride and calcium chloride was also analyzed. Addition of sodium chloride did not change the distribution profile of the native sample showing that the inhibitory effect is due to Ca(2+) and not to Cl(-). Addition of calcium chloride with 1:1 analyte/salt molar ratio gave spectra with less efficient desorption/ionization of oligomers; the signals of these oligomers were completely suppressed when the addition of the salt became massive (1:100 analyte/salt molar ratio). Copyright (c) 2005 John Wiley & Sons, Ltd.

Matrix effects in inductively coupled plasma mass spectrometry

International Nuclear Information System (INIS)

Chen, Xiaoshan.

1995-01-01

The inductively coupled plasma is an electrodeless discharge in a gas (usually Ar) at atmospheric pressure. Radio frequency energy generated by a RF power source is inductively coupled to the plasma gas through a water cooled load coil. In ICP-MS the open-quotes Fasselclose quotes TAX quartz torch commonly used in emission is mounted horizontally. The sample aerosol is introduced into the central flow, where the gas kinetic temperature is about 5000 K. The aerosol is vaporized, atomized, excited and ionized in the plasma, and the ions are subsequently extracted through two metal apertures (sampler and skimmer) into the mass spectrometer. In ICP-MS, the matrix effects, or non-spectroscopic interferences, can be defined as the type of interferences caused by dissolved concomitant salt ions in the solution. Matrix effects can be divided into two categories: (1) signal drift due to the deposition of solids on the sampling apertures; and/or (2) signal suppression or enhancement by the presence of the dissolved salts. The first category is now reasonably understood. The dissolved salts, especially refractory oxides, tend to deposit on the cool tip of the sampling cone. The clogging of the orifices reduces the ion flow into the ICP-MS, lowers the pressure in the first stage of ICP-MS, and enhances the level of metal oxide ions. Because the extent of the clogging increases with the time, the signal drifts down. Even at the very early stage of the development of ICP-MS, matrix effects had been observed. Houk et al. found out that the ICP-MS was not tolerant to solutions containing significant amounts of dissolved solids

Light-Front Holography and AdS/QCD Correspondence

Energy Technology Data Exchange (ETDEWEB)

Brodsky, Stanley J.; de Teramond, Guy F.

2008-04-23

Light-Front Holography is a remarkable consequence of the correspondence between string theory in AdS space and conformal field theories in physical-space time. It allows string modes {Phi}(z) in the AdS fifth dimension to be precisely mapped to the light-front wavefunctions of hadrons in terms of a specific light-front impact variable {zeta} which measures the separation of the quark and gluonic constituents within the hadron. This mapping was originally obtained by matching the exact expression for electromagnetic current matrix elements in AdS space with the corresponding exact expression for the current matrix element using light-front theory in physical space-time. More recently we have shown that one obtains the identical holographic mapping using matrix elements of the energy-momentum tensor, thus providing an important consistency test and verification of holographic mapping from AdS to physical observables defined on the light-front. The resulting light-front Schrodinger equations predicted from AdS/QCD give a good representation of the observed meson and baryon spectra and give excellent phenomenological predictions for amplitudes such as electromagnetic form factors and decay constants.

Electrospray ionization and matrix assisted laser desorption/ionization mass spectrometry: powerful analytical tools in recombinant protein chemistry

DEFF Research Database (Denmark)

Andersen, Jens S.; Svensson, B; Roepstorff, P

1996-01-01

Electrospray ionization and matrix assisted laser desorption/ionization are effective ionization methods for mass spectrometry of biomolecules. Here we describe the capabilities of these methods for peptide and protein characterization in biotechnology. An integrated analytical strategy is presen......Electrospray ionization and matrix assisted laser desorption/ionization are effective ionization methods for mass spectrometry of biomolecules. Here we describe the capabilities of these methods for peptide and protein characterization in biotechnology. An integrated analytical strategy...... is presented encompassing protein characterization prior to and after cloning of the corresponding gene....

Determination of microcystin-LR in drinking water using UPLC tandem mass spectrometry-matrix effects and measurement.

Science.gov (United States)

Li, Wei; Duan, Jinming; Niu, Chaoying; Qiang, Naichen; Mulcahy, Dennis

2011-10-01

A simple detection method using ultra-performance liquid chromatography electrospray ionisation tandem mass spectrometry (UPLC-ESI-MS-MS) coupled with the sample dilution method for determining trace microcystin-LR (MC-LR) in drinking water is presented. The limit of detection (LOD) was 0.04 µg/L and the limit of quantitation (LOQ) was 0.1 µg/L. Water matrix effects of ionic strength, dissolved organic carbon (DOC) and pH were examined. The results indicate that signal detection intensity for MC-LR was significantly suppressed as the ionic strength increased from ultrapure water condition, whereas it increased slightly with solution pH and DOC at low concentrations. However, addition of methanol (MeOH) into the sample was able to counter the signal suppression effects. In this study, dilution of the tap water sample by adding 4% MeOH (v/v) was observed to be adequate to compensate for the signal suppression. The recoveries of the samples fortified with MC-LR (0.2, 1, and 10 µg/L) for three different tap water samples ranged from 84.4% to 112.9%.

Coumarins as new matrices for matrix-assisted laser-desorption/ionization Fourier transform ion cyclotron resonance mass spectrometric analysis of hydrophobic compounds

Energy Technology Data Exchange (ETDEWEB)

Wang, Hang, E-mail: hangwang@sjtu.edu.cn [Instrumental Analysis Center, Shanghai Jiao Tong University, Dongchuan Road 800, Shanghai 200240 (China); Dai, Bona [Instrumental Analysis Center, Shanghai Jiao Tong University, Dongchuan Road 800, Shanghai 200240 (China); Liu, Bin [Key Laboratory of Kidney Disease Pathogenesis and Intervention of Hubei Province, College of Medicine, Hubei Polytechnic University, Huangshi, Hubei 435003 (China); Lu, Han [Department of Anesthesiology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine (SJTU-SM), 197, Rui Jin Er Road, Shanghai 200025 (China)

2015-07-02

Highlights: • Coumarins were used as new MALDI matrices. • Coumarins were used for MALDI-FT ICR MS detection of hydrophobic compounds. • DCA had improvement in detection sensitivity, stability, selectivity and reproducibility. • DCA was applied to sterols detection in yeast cells. - Abstract: Hydrophobic compounds with hydroxyl, aldehyde or ketone groups are generally difficult to detect using matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS), because these compounds have low proton affinity and are poorly ionized by MALDI. Herein, coumarins have been used as new matrices for MALDI-MS analysis of a variety of hydrophobic compounds with low ionization efficiency, including steroids, coenzyme Q10, a cyclic lipopeptide and cholesterol oleate. Five coumarins, including coumarin, umbelliferone, esculetin, 7-hydroxycoumarin-3-carboxylic acid (HCA) and 6,7-dihydroxycoumarin-3-carboxylic acid (DCA), were compared with the conventional matrices of 2,5-dihydroxybenzoic acid (DHB) and α-cyano-4-hydroxycinnamic acid (CHCA). Coumarins with hydroxyl or carboxylic acid groups enabled detection. Taking DCA as an example, this matrix proved to be superior to DHB or CHCA in detection sensitivity, stability, spot-to-spot and sample-to-sample reproducibility, and accuracy. DCA increased the stability of the target compounds and decreased the loss of water. The [M + Na]{sup +} peaks were observed for all target compounds by adding NaCl as an additive, and the [M − H{sub 2}O + H]{sup +} and [M + H]{sup +} peaks decreased. DCA was selected for the identification of sterols in yeast cells, and thirteen sterols were detected by Fourier transform ion cyclotron resonance (FT ICR) mass spectrometry. This work demonstrates the potential of DCA as a new matrix for detection of hydrophobic molecules by MALDI-MS and provides an alternative tool for screening sterols in antifungal research.

Measurement of the top quark mass in the dilepton final state using the matrix element method

Energy Technology Data Exchange (ETDEWEB)

Grohsjean, Alexander [Ludwig Maximilian Univ., Munich (Germany)

2008-12-15

The top quark, discovered in 1995 by the CDF and D0 experiments at the Fermilab Tevatron Collider, is the heaviest known fundamental particle. The precise knowledge of its mass yields important constraints on the mass of the yet-unobserved Higgs boson and allows to probe for physics beyond the Standard Model. The first measurement of the top quark mass in the dilepton channel with the Matrix Element method at the D0 experiment is presented. After a short description of the experimental environment and the reconstruction chain from hits in the detector to physical objects, a detailed review of the Matrix Element method is given. The Matrix Element method is based on the likelihood to observe a given event under the assumption of the quantity to be measured, e.g. the mass of the top quark. The method has undergone significant modifications and improvements compared to previous measurements in the lepton+jets channel: the two undetected neutrinos require a new reconstruction scheme for the four-momenta of the final state particles, the small event sample demands the modeling of additional jets in the signal likelihood, and a new likelihood is designed to account for the main source of background containing tauonic Z decay. The Matrix Element method is validated on Monte Carlo simulated events at the generator level. For the measurement, calibration curves are derived from events that are run through the full D0 detector simulation. The analysis makes use of the Run II data set recorded between April 2002 and May 2008 corresponding to an integrated luminosity of 2.8 fb^-1. A total of 107 t$\\bar{t}$ candidate events with one electron and one muon in the final state are selected. Applying the Matrix Element method to this data set, the top quark mass is measured to be m_top^{Run IIa} = 170.6 ± 6.1(stat.)_-1.5^+2.1(syst.)GeV; m_top^{Run IIb} = 174.1 ± 4.4(stat.)_-1.8^+2.5(syst.)GeV; m

Structural characterization of phospholipids by matrix-assisted laser desorption/ionization Fourier transform ion cyclotron resonance mass spectrometry.

Science.gov (United States)

Marto, J A; White, F M; Seldomridge, S; Marshall, A G

1995-11-01

Matrix-assisted laser desorption/ionization (MALDI) Fourier transform ion cyclotron resonance mass spectrometry provides for structural analysis of the principal biological phospholipids: glycerophosphatidylcholine, -ethanolamine, -serine, and -inositol. Both positive and negative molecular or quasimolecular ions are generated in high abundance. Isolated molecular ions may be collisionally activated in the source side of a dual trap mass analyzer, yielding fragments serving to identify the polar head group (positive ion mode) and fatty acid side chains (negative ion mode). Azimuthal quadrupolar excitation following collisionally activated dissociation refocuses productions close to the solenoid axis; subsequent transfer of product ions to the analyzer ion trap allows for high-resolution mass analysis. Cyro-cooling of the sample probe with liquid nitrogen greatly reduces matrix adduction encountered in the negative ion mode.

Iron oxide nanomatrix facilitating metal ionization in matrix-assisted laser desorption/ionization mass spectrometry.

Science.gov (United States)

Obena, Rofeamor P; Lin, Po-Chiao; Lu, Ying-Wei; Li, I-Che; del Mundo, Florian; Arco, Susan dR; Nuesca, Guillermo M; Lin, Chung-Chen; Chen, Yu-Ju

2011-12-15

The significance and epidemiological effects of metals to life necessitate the development of direct, efficient, and rapid method of analysis. Taking advantage of its simple, fast, and high-throughput features, we present a novel approach to metal ion detection by matrix-functionalized magnetic nanoparticle (matrix@MNP)-assisted MALDI-MS. Utilizing 21 biologically and environmentally relevant metal ion solutions, the performance of core and matrix@MNP against conventional matrixes in MALDI-MS and laser desorption ionization (LDI) MS were systemically tested to evaluate the versatility of matrix@MNP as ionization element. The matrix@MNPs provided 20- to >100-fold enhancement on detection sensitivity of metal ions and unambiguous identification through characteristic isotope patterns and accurate mass (<5 ppm), which may be attributed to its multifunctional role as metal chelator, preconcentrator, absorber, and reservoir of energy. Together with the comparison on the ionization behaviors of various metals having different ionization potentials (IP), we formulated a metal ionization mechanism model, alluding to the role of exciton pooling in matrix@MNP-assisted MALDI-MS. Moreover, the detection of Cu in spiked tap water demonstrated the practicability of this new approach as an efficient and direct alternative tool for fast, sensitive, and accurate determination of trace metal ions in real samples.

Matrix effect in the analysis of drugs of abuse from urine with desorption atmospheric pressure photoionization-mass spectrometry (DAPPI-MS) and desorption electrospray ionization-mass spectrometry (DESI-MS)

International Nuclear Information System (INIS)

Suni, Niina M.; Lindfors, Pia; Laine, Olli; Ostman, Pekka; Ojanperae, Ilkka; Kotiaho, Tapio; Kauppila, Tiina J.; Kostiainen, Risto

2011-01-01

Highlights: → DAPPI-MS and DESI-MSI in the analysis of drugs of abuse from urine. → DAPPI-MS has better urine matrix tolerance over DESI-MS. → Urine matrix can affect the ionization mechanism in DAPPI. → DAPPI-MS/MS can be used for screening of drugs from urine after sample pretreatment. - Abstract: We have studied the matrix effect within direct analysis of benzodiazepines and opioids from urine with desorption electrospray ionization-mass spectrometry (DESI-MS) and desorption atmospheric pressure photoionization-mass spectrometry (DAPPI-MS). The urine matrix was found to affect the ionization mechanism of the opioids in DAPPI-MS favoring proton transfer over charge exchange reaction. The sensitivity for the drugs in solvent matrix was at the same level with DESI-MS and DAPPI-MS (LODs 0.05-6 μg mL -1 ) but the decrease in sensitivity due to the urine matrix was higher with DESI (typically 20-160-fold) than with DAPPI (typically 2-15-fold) indicating better matrix tolerance of DAPPI over DESI. Also in MS/MS mode, DAPPI provided better sensitivity than DESI for the drugs in urine. The feasibility of DAPPI-MS/MS was then studied in screening the same drugs from five authentic, forensic post mortem urine samples. A reference measurement with gas chromatography-mass spectrometry (GC-MS) (including pretreatment) revealed 16 findings from the samples, whereas with DAPPI-MS/MS after sample pretreatment, 15 findings were made. Sample pretreatment was found necessary, since only eight findings were made from the same samples untreated.

Matrix effect in the analysis of drugs of abuse from urine with desorption atmospheric pressure photoionization-mass spectrometry (DAPPI-MS) and desorption electrospray ionization-mass spectrometry (DESI-MS)

Energy Technology Data Exchange (ETDEWEB)

Suni, Niina M.; Lindfors, Pia; Laine, Olli [Division of Pharmaceutical Chemistry, University of Helsinki, P.O. Box 56, Helsinki FI-00014 (Finland); Ostman, Pekka; Ojanperae, Ilkka [Hjelt Institute, Department of Forensic Medicine, University of Helsinki, P.O. Box 40, Helsinki FI-00014 (Finland); Kotiaho, Tapio [Division of Pharmaceutical Chemistry, University of Helsinki, P.O. Box 56, Helsinki FI-00014 (Finland); Laboratory of Analytical Chemistry, Department of Chemistry, University of Helsinki, P.O. Box 55, Helsinki FI-00014 (Finland); Kauppila, Tiina J. [Division of Pharmaceutical Chemistry, University of Helsinki, P.O. Box 56, Helsinki FI-00014 (Finland); Kostiainen, Risto, E-mail: risto.kostiainen@helsinki.fi [Division of Pharmaceutical Chemistry, University of Helsinki, P.O. Box 56, Helsinki FI-00014 (Finland)

2011-08-05

Highlights: {yields} DAPPI-MS and DESI-MSI in the analysis of drugs of abuse from urine. {yields} DAPPI-MS has better urine matrix tolerance over DESI-MS. {yields} Urine matrix can affect the ionization mechanism in DAPPI. {yields} DAPPI-MS/MS can be used for screening of drugs from urine after sample pretreatment. - Abstract: We have studied the matrix effect within direct analysis of benzodiazepines and opioids from urine with desorption electrospray ionization-mass spectrometry (DESI-MS) and desorption atmospheric pressure photoionization-mass spectrometry (DAPPI-MS). The urine matrix was found to affect the ionization mechanism of the opioids in DAPPI-MS favoring proton transfer over charge exchange reaction. The sensitivity for the drugs in solvent matrix was at the same level with DESI-MS and DAPPI-MS (LODs 0.05-6 {mu}g mL{sup -1}) but the decrease in sensitivity due to the urine matrix was higher with DESI (typically 20-160-fold) than with DAPPI (typically 2-15-fold) indicating better matrix tolerance of DAPPI over DESI. Also in MS/MS mode, DAPPI provided better sensitivity than DESI for the drugs in urine. The feasibility of DAPPI-MS/MS was then studied in screening the same drugs from five authentic, forensic post mortem urine samples. A reference measurement with gas chromatography-mass spectrometry (GC-MS) (including pretreatment) revealed 16 findings from the samples, whereas with DAPPI-MS/MS after sample pretreatment, 15 findings were made. Sample pretreatment was found necessary, since only eight findings were made from the same samples untreated.

Thymol treatment of bacteria prior to matrix-assisted laser desorption/ionization time-of-flight mass spectrometric analysis aids in identifying certain bacteria at the subspecies level.

Science.gov (United States)

Holland, Ricky D; Wilkes, Jon G; Cooper, Willie M; Alusta, Pierre; Williams, Anna; Pearce, Bruce; Beaudoin, Michael; Buzatu, Dan

2014-12-15

The identification of bacteria based on mass spectra produced by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS) has become routine since its introduction in 1996. The major drawback is that bacterial patterns produced by MALDI are dependent on sample preparation prior to analysis. This results in poor reproducibility in identifying bacterial types and between laboratories. The need for a more broadly applicable and useful sample handling procedure is warranted. Thymol was added to the suspension solvent of bacteria prior to MALDI analysis. The suspension solvent consisted of ethanol, water and TFA. The bacterium was added to the thymol suspension solvent and heated. An aliquot of the bacterial suspension was mixed directly with the matrix solution at a 9:1 ratio, matrix/bacteria solution, respectively. The mixture was then placed on the MALDI plate and allowed to air dry before MALDI analysis. The thymol method improved the quality of spectra and number of peaks when compared to other sample preparation procedures studied. The bacterium-identifying biomarkers assigned to four strains of E. coli were statistically 95% reproducible analyzed on three separate days. The thymol method successfully differentiated between the four E. coli strains. In addition, the thymol procedure could identify nine out of ten S. enterica serovars over a 3-day period and nine S. Typhimurium strains from the other ten serovars 90% of the time over the same period. The thymol method can identify certain bacteria at the sub-species level and yield reproducible results over time. It improves the quality of spectra by increasing the number of peaks when compared to the other sample preparation methods assessed in this study. Published in 2014. This article is a U.S. Government work and is in the public domain in the USA. Published in 2014. This article is a U.S. Government work and is in the public domain in the USA.

Quantitation of peptides and proteins by matrix-assisted laser desorption/ionization mass spectrometry using (18)O-labeled internal standards

DEFF Research Database (Denmark)

Mirgorodskaya, O A; Kozmin, Y P; Titov, M I

2000-01-01

A method for quantitating proteins and peptides in the low picomole and sub-picomole range has been developed using matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) with internal (18)O-labeled standards. A simple procedure is proposed to produce such internal standards for...... inhibitor, were quantified by MALDI-time-of-flight (TOF) mass spectrometry.......A method for quantitating proteins and peptides in the low picomole and sub-picomole range has been developed using matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) with internal (18)O-labeled standards. A simple procedure is proposed to produce such internal standards...

Double Beta Decay and Neutrino Masses Accuracy of the Nuclear Matrix Elements

International Nuclear Information System (INIS)

Faessler, Amand

2005-01-01

The neutrinoless double beta decay is forbidden in the standard model of the electroweak and strong interaction but allowed in most Grand Unified Theories (GUT's). Only if the neutrino is a Majorana particle (identical with its antiparticle) and if it has a mass, the neutrinoless double beta decay is allowed. Apart of one claim that the neutrinoless double beta decay in 76 Ge is measured, one has only upper limits for this transition probability. But even the upper limits allow to give upper limits for the electron Majorana neutrino mass and upper limits for parameters of GUT's and the minimal R-parity violating supersymmetric model. One further can give lower limits for the vector boson mediating mainly the right-handed weak interaction and the heavy mainly right-handed Majorana neutrino in left-right symmetric GUT's. For that one has to assume that the specific mechanism is the leading one for the neutrinoless double beta decay and one has to be able to calculate reliably the corresponding nuclear matrix elements. In the present contribution, one discusses the accuracy of the present status of calculating the nuclear matrix elements and the corresponding limits of GUT's and supersymmetric parameters

Nucleon scalar matrix elements with N{sub f}=2+1+1 twisted mass fermions

Energy Technology Data Exchange (ETDEWEB)

Dinter, Simon; Drach, Vincent; Jansen, Karl [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC

2011-12-15

We investigate scalar matrix elements of the nucleon using N{sub f}=2+1+1 flavors of maximally twisted mass fermions at a fixed value of the lattice spacing of a{approx}0.078 fm. We compute disconnected contributions to the relevant three-point functions using an efficient noise reduction technique. Using these methods together with an only multiplicative renormalization applicable for twisted mass fermions, allows us to obtain accurate results in the light and strange sector. (orig.)

Symmetric neutrino mass matrix with two zeros in SUSY SO(10) GUT

International Nuclear Information System (INIS)

Bando, Masako; Kaneko, Satoru; Obara, Midori; Tanimoto, Morimitsu

2004-01-01

We study the symmetric 2-zero texture of lepton and quark mass matrix, for the SUSY SO(10) GUT model including the Pati-Salam symmetry. We show that our model can simultaneously explain the current neutrino experimental data, predicted rate of lepton flavor violating processes are safely below the experimental bounds and baryon asymmetry of the universe can be obtained through thermal leptogenesis. (author)

An AdS3 dual for minimal model CFTs

International Nuclear Information System (INIS)

Gaberdiel, Matthias R.; Gopakumar, Rajesh

2011-01-01

We propose a duality between the 2d W N minimal models in the large N't Hooft limit, and a family of higher spin theories on AdS 3 . The 2d conformal field theories (CFTs) can be described as Wess-Zumino-Witten coset models, and include, for N=2, the usual Virasoro unitary series. The dual bulk theory contains, in addition to the massless higher spin fields, two complex scalars (of equal mass). The mass is directly related to the 't Hooft coupling constant of the dual CFT. We give convincing evidence that the spectra of the two theories match precisely for all values of the 't Hooft coupling. We also show that the renormalization group flows in the 2d CFT agree exactly with the usual AdS/CFT prediction of the gravity theory. Our proposal is in many ways analogous to the Klebanov-Polyakov conjecture for an AdS 4 dual for the singlet sector of large N vector models.

q-Poincaré supersymmetry in AdS5/CFT4

Science.gov (United States)

Borsato, Riccardo; Torrielli, Alessandro

2018-03-01

We consider the exact S-matrix governing the planar spectral problem for strings on AdS5 ×S5 and N = 4 super Yang-Mills, and we show that it is invariant under a novel "boost" symmetry, which acts as a differentiation with respect to the particle momentum. This generator leads us also to reinterpret the usual centrally extended psu (2 | 2) symmetry, and to conclude that the S-matrix is invariant under a q-Poincaré supersymmetry algebra, where the deformation parameter is related to the 't Hooft coupling. We determine the two-particle action (coproduct) that turns out to be non-local, and study the property of the new symmetry under crossing transformations. We look at both the strong-coupling (large tension in the string theory) and weak-coupling (spin-chain description of the gauge theory) limits; in the former regime we calculate the cobracket utilising the universal classical r-matrix of Beisert and Spill. In the eventuality that the boost has higher partners, we also construct a quantum affine version of 2D Poincaré symmetry, by contraction of the quantum affine algebra Uq (sl2 ˆ) in Drinfeld's second realisation.

q-Poincaré supersymmetry in AdS5/CFT4

Directory of Open Access Journals (Sweden)

Riccardo Borsato

2018-03-01

Full Text Available We consider the exact S-matrix governing the planar spectral problem for strings on AdS5×S5 and N=4 super Yang–Mills, and we show that it is invariant under a novel “boost” symmetry, which acts as a differentiation with respect to the particle momentum. This generator leads us also to reinterpret the usual centrally extended psu(2|2 symmetry, and to conclude that the S-matrix is invariant under a q-Poincaré supersymmetry algebra, where the deformation parameter is related to the 't Hooft coupling. We determine the two-particle action (coproduct that turns out to be non-local, and study the property of the new symmetry under crossing transformations. We look at both the strong-coupling (large tension in the string theory and weak-coupling (spin-chain description of the gauge theory limits; in the former regime we calculate the cobracket utilising the universal classical r-matrix of Beisert and Spill. In the eventuality that the boost has higher partners, we also construct a quantum affine version of 2D Poincaré symmetry, by contraction of the quantum affine algebra Uq(sl2ˆ in Drinfeld's second realisation.

Wess-Zumino terms for AdS D-branes

International Nuclear Information System (INIS)

Hatsuda, Machiko; Kamimura, Kiyoshi

2004-01-01

We show that Wess-Zumino terms for Dp branes with p>0 in the anti-de Sitter (AdS) space are given in terms of 'left-invariant' currents on the super-AdS group or the 'expanded' super-AdS group. As a result there is no topological extension of the super-AdS algebra. In the flat limit the global Lorentz rotational charges of the AdS space turn out to be brane charges of the supertranslation algebra representing the BPS mass. We also show that a D-instanton is described by the GL(1) degree of freedom in the Roiban-Siegel formalism based on the GL(4 vertical bar 4)/[Sp(4)xGL(1)]2 coset

Holographic description of AdS2 black holes

International Nuclear Information System (INIS)

Castro, Alejandra; Larsen, Finn; Grumiller, Daniel; McNees, Robert

2008-01-01

We develop the holographic renormalization of AdS 2 gravity systematically. We find that a bulk Maxwell term necessitates a boundary mass term for the gauge field and verify that this unusual term is invariant under gauge transformations that preserve the boundary conditions. We determine the energy-momentum tensor and the central charge, recovering recent results by Hartman and Strominger. We show that our expressions are consistent with dimensional reduction of the AdS 3 energy-momentum tensor and the Brown-Henneaux central charge. As an application of our results we interpret the entropy of AdS 2 black holes as the ground state entropy of a dual CFT.

Penrose inequality for asymptotically AdS spaces

International Nuclear Information System (INIS)

Itkin, Igor; Oz, Yaron

2012-01-01

In general relativity, the Penrose inequality relates the mass and the entropy associated with a gravitational background. If the inequality is violated by an initial Cauchy data, it suggests a creation of a naked singularity, thus providing means to consider the cosmic censorship hypothesis. We propose a general form of Penrose inequality for asymptotically locally AdS spaces.

Penrose inequality for asymptotically AdS spaces

Energy Technology Data Exchange (ETDEWEB)

Itkin, Igor [Raymond and Beverly Sackler School of Physics and Astronomy, Tel-Aviv University, Tel-Aviv 69978 (Israel); Oz, Yaron, E-mail: yaronoz@post.tau.ac.il [Raymond and Beverly Sackler School of Physics and Astronomy, Tel-Aviv University, Tel-Aviv 69978 (Israel)

2012-02-28

In general relativity, the Penrose inequality relates the mass and the entropy associated with a gravitational background. If the inequality is violated by an initial Cauchy data, it suggests a creation of a naked singularity, thus providing means to consider the cosmic censorship hypothesis. We propose a general form of Penrose inequality for asymptotically locally AdS spaces.

Metrix Matrix: A Cloud-Based System for Tracking Non-Relative Value Unit Value-Added Work Metrics.

Science.gov (United States)

Kovacs, Mark D; Sheafor, Douglas H; Thacker, Paul G; Hardie, Andrew D; Costello, Philip

2018-03-01

In the era of value-based medicine, it will become increasingly important for radiologists to provide metrics that demonstrate their value beyond clinical productivity. In this article the authors describe their institution's development of an easy-to-use system for tracking value-added but non-relative value unit (RVU)-based activities. Metrix Matrix is an efficient cloud-based system for tracking value-added work. A password-protected home page contains links to web-based forms created using Google Forms, with collected data populating Google Sheets spreadsheets. Value-added work metrics selected for tracking included interdisciplinary conferences, hospital committee meetings, consulting on nonbilled outside studies, and practice-based quality improvement. Over a period of 4 months, value-added work data were collected for all clinical attending faculty members in a university-based radiology department (n = 39). Time required for data entry was analyzed for 2 faculty members over the same time period. Thirty-nine faculty members (equivalent to 36.4 full-time equivalents) reported a total of 1,223.5 hours of value-added work time (VAWT). A formula was used to calculate "value-added RVUs" (vRVUs) from VAWT. VAWT amounted to 5,793.6 vRVUs or 6.0% of total work performed (vRVUs plus work RVUs [wRVUs]). Were vRVUs considered equivalent to wRVUs for staffing purposes, this would require an additional 2.3 full-time equivalents, on the basis of average wRVU calculations. Mean data entry time was 56.1 seconds per day per faculty member. As health care reimbursement evolves with an emphasis on value-based medicine, it is imperative that radiologists demonstrate the value they add to patient care beyond wRVUs. This free and easy-to-use cloud-based system allows the efficient quantification of value-added work activities. Copyright © 2017 American College of Radiology. Published by Elsevier Inc. All rights reserved.

Thermodynamics of AdS black holes in Einstein-Scalar gravity

Energy Technology Data Exchange (ETDEWEB)

Lü, H. [Department of Physics, Beijing Normal University,Beijing 100875 (China); Pope, C.N. [George P. & Cynthia Woods Mitchell Institute for Fundamental Physics and Astronomy,Texas A& M University,College Station, TX 77843 (United States); DAMTP, Centre for Mathematical Sciences, Cambridge University,Wilberforce Road, Cambridge CB3 OWA (United Kingdom); Wen, Qiang [Department of Physics, Renmin University of China,Beijing 100872 (China)

2015-03-31

We study the thermodynamics of n-dimensional static asymptotically AdS black holes in Einstein gravity coupled to a scalar field with a potential admitting a stationary point with an AdS vacuum. Such black holes with non-trivial scalar hair can exist provided that the mass-squared of the scalar field is negative, and above the Breitenlohner-Freedman bound. We use the Wald procedure to derive the first law of thermodynamics for these black holes, showing how the scalar hair (or “charge”) contributes non-trivially in the expression. We show in general that a black hole mass can be deduced by isolating an integrable contribution to the (non-integrable) variation of the Hamiltonian arising in the Wald construction, and that this is consistent with the mass calculated using the renormalised holographic stress tensor and also, in those cases where it is defined, with the mass calculated using the conformal method of Ashtekar, Magnon and Das. Similar arguments can also be given for the smooth solitonic solutions in these theories. Neither the black hole nor the soliton solutions can be constructed explicitly, and we carry out a numerical analysis to demonstrate their existence and to provide approximate checks on some of our thermodynamic results.

Estimation of added-mass and damping coefficients of a tethered spherical float using potential flow theory

Digital Repository Service at National Institute of Oceanography (India)

Vethamony, P.; Chandramohan, P.; Sastry, J.S.; Narasimhan, S.

Added-mass (alpha) and damping coefficients (beta) of a tethered spherical float, undergoing oscillatory motion in sinusoidal waves, have been derived from the motion generated velocity potential for one degree-of-freedom (surge) using potential...

Constraints on a general 3-generation neutrino mass matrix from neutrino data application to the MSSM with R-parity violation

CERN Document Server

Abada, A

2000-01-01

We consider a general symmetric $(3\\times 3)$ mass matrix for three generations of neutrinos. Imposing the constraints, from the atmospheric neutrino and solar neutrino anomalies as well as from the CHOOZ experiment, on the mass squared differences and on the mixing angles, we identify the ranges of allowed inputs for the 6 matrix elements. We apply our results to Majorana left-handed neutrino masses generated at tree level and through The present experimental results on neutrinos from laboratories, cosmology and astrophysics are implemented to either put bounds on trilinear ($\\lambda_{ijk}, or constrain combinations of products of these couplings.

Matrix isolation-infrared and mass spectrometric studies of high-temperature molecules

International Nuclear Information System (INIS)

Dickinson, S.

1987-08-01

Matrix isolation-infrared spectroscopy and mass spectrometry have been developed at AEE Winfrith to study the high-temperature vapour species which could be generated during a hypothetical severe reactor accident. The principles of the techniques and the instruments are described in detail, and examples of their application to specific systems discussed. Although these examples refer to high-temperature chemical species which are relevant to reactor safety assessments, the techniques are equally applicable to other processes where the characterisation of transient vapour-phase species is required. (author)

Validity of M-3Y force equivalent G-matrix elements for calculations of the nuclear structure in heavy mass region

International Nuclear Information System (INIS)

Cheng Lan; Huang Weizhi; Zhou Baosen

1996-01-01

Using the matrix elements of M-3Y force as the equivalent G-matrix elements, the spectra of 210 Pb, 206 Pb, 206 Hg and 210 Po are calculated in the framework of the Folded Diagram Method. The results show that such equivalent matrix elements are suitable for microscopic calculations of the nuclear structure in heavy mass region

Alkaloid profiling of the Chinese herbal medicine Fuzi by combination of matrix-assisted laser desorption ionization mass spectrometry with liquid chromatography-mass spectrometry

NARCIS (Netherlands)

Wang, J.; Heijden, R. van der; Spijksma, G.; Reijmers, T.; Wang, M.; Xu, G.; Hankemeier, T.; Greef, J. van der

2009-01-01

A matrix-assisted laser desorption ionization mass spectrometry (MALDI-MS) method was developed for the high throughput and robust qualitative profiling of alkaloids in Fuzi-the processed lateral roots of the Chinese herbal medicine Aconitum carmichaeli Debx (A. carmichaeli). After optimization,

Physical matrix correction for RFA of mass and special glasses

International Nuclear Information System (INIS)

Medicus, G.; Ritter, R.

1984-01-01

A theoretical matrix correction model with relatively complex mass absorption coefficients is reported, which takes into account the adsorption of the stimulating radiation and the radiation in the specimen to be measured, as well as the geometry of the spectrometer. With the realized concept of an effective primary wave length, good correction results were obtained over large regions of concentrations and elements. The computer program renders possible besides of the usual reference measurement at uniform reference wave length - the reference of several elements in the specimen to one special element of the reference specimen. The correction method was tested with 42 test glasses, which were previously analyzed. (author)

Distance descending ordering method: An O(n) algorithm for inverting the mass matrix in simulation of macromolecules with long branches

Science.gov (United States)

Xu, Xiankun; Li, Peiwen

2017-11-01

Fixman's work in 1974 and the follow-up studies have developed a method that can factorize the inverse of mass matrix into an arithmetic combination of three sparse matrices-one of them is positive definite and needs to be further factorized by using the Cholesky decomposition or similar methods. When the molecule subjected to study is of serial chain structure, this method can achieve O (n) time complexity. However, for molecules with long branches, Cholesky decomposition about the corresponding positive definite matrix will introduce massive fill-in due to its nonzero structure. Although there are several methods can be used to reduce the number of fill-in, none of them could strictly guarantee for zero fill-in for all molecules according to our test, and thus cannot obtain O (n) time complexity by using these traditional methods. In this paper we present a new method that can guarantee for no fill-in in doing the Cholesky decomposition, which was developed based on the correlations between the mass matrix and the geometrical structure of molecules. As a result, the inverting of mass matrix will remain the O (n) time complexity, no matter the molecule structure has long branches or not.

Transfer matrix in 1D Schroedinger problems with constant and position-dependent mass

International Nuclear Information System (INIS)

Perez-Alvarez, R.; Rodriguez-Coppola, H.

1987-10-01

We consider the transfer matrix method for obtaining properties of standard wells and barriers in one-dimensional Schroedinger problems with constant and position-dependent mass. We report the formulae for the energy levels of a well and the transmission coefficient of a barrier. We demonstrate the continuity between virtual bound states and bound states in a well of position-dependent mass and the relation between the zero energy gap states of a periodic potential problem with the corresponding energies of the non-periodic ones with transmission coefficient equal to one. The calculations were carried out for a wide class of potential profiles. (author). 30 refs, 2 figs

Warped AdS3 black holes

International Nuclear Information System (INIS)

Anninos, Dionysios; Li Wei; Padi, Megha; Song Wei; Strominger, Andrew

2009-01-01

Three dimensional topologically massive gravity (TMG) with a negative cosmological constant -l -2 and positive Newton constant G admits an AdS 3 vacuum solution for any value of the graviton mass μ. These are all known to be perturbatively unstable except at the recently explored chiral point μl = 1. However we show herein that for every value of μl ≠ 3 there are two other (potentially stable) vacuum solutions given by SL(2,R) x U(1)-invariant warped AdS 3 geometries, with a timelike or spacelike U(1) isometry. Critical behavior occurs at μl = 3, where the warping transitions from a stretching to a squashing, and there are a pair of warped solutions with a null U(1) isometry. For μl > 3, there are known warped black hole solutions which are asymptotic to warped AdS 3 . We show that these black holes are discrete quotients of warped AdS 3 just as BTZ black holes are discrete quotients of ordinary AdS 3 . Moreover new solutions of this type, relevant to any theory with warped AdS 3 solutions, are exhibited. Finally we note that the black hole thermodynamics is consistent with the hypothesis that, for μl > 3, the warped AdS 3 ground state of TMG is holographically dual to a 2D boundary CFT with central charges c R -formula and c L -formula.

Matrix effect in analysis of pesticide residues in fruits and vegetables by high performance liquid chromatography with quadrupole-time of flight mass spectrometry

Directory of Open Access Journals (Sweden)

Andoralov A.M.

2017-03-01

Full Text Available For modern food safety control are using techniques that allow to determinate a large number of components. So for determination of pesticide residues in fruits and vegetables commonly used methods of gas and liquid chromatography with time-of-flight mass-spectrometric detection. This system allows to carry out quantitative determination several hundreds of pesticides and their identification by the characteristic fragments of the mass spectrum. The main problem when using mass spectrometric detection is a matrix effect, which is caused by the influence of matrix components extracted with pesticides from the sample. In this work, attempts have been made to reduce the influence of the matrix in the analysis of pesticide residues by high performance liquid chromatography with time of flight mass spectrometry (HPLC / TOFMS.

Matrix-Assisted Laser Desorption/Ionization Imaging Mass Spectrometry for the Investigation of Proteins and Peptides

Science.gov (United States)

Burnum, Kristin E.; Frappier, Sara L.; Caprioli, Richard M.

2008-07-01

Mass spectrometry (MS) is an excellent technology for molecular imaging because of its high data dimensionality. MS can monitor thousands of individual molecular data channels measured as mass-to-charge (m/z). We describe the use of matrix-assisted laser desorption/ionization (MALDI) MS for the image analysis of proteins, peptides, lipids, drugs, and metabolites in tissues. We discuss the basic instrumentation and sample preparation methods needed to produce high-resolution images and high image reproducibility. Matrix-addition protocols are briefly discussed along with normal operating procedures, and selected biological and medical applications of MALDI imaging MS are described. We give examples of both two- and three-dimensional imaging, including normal mouse embryo implantation, sperm maturation in mouse epididymis, protein distributions in brain sections, protein alterations as a result of drug administration, and protein changes in brain due to neurodegeneration and tumor formation. Advantages of this technology and future challenges for its improvement are discussed.

Matrix-Assisted Laser Desorption Ionization Mass Spectrometry of Compounds Containing Carboxyl Groups Using CdTe and CuO Nanoparticles

OpenAIRE

Megumi Sakurai; Taro Sato; Jiawei Xu; Soichi Sato; Tatsuya Fujino

2018-01-01

Matrix-assisted laser desorption ionization mass spectrometry of compounds containing carboxyl groups was carried out by using semiconductor nanoparticles (CdTe and CuO) as the matrix. Salicylic acid (Sal), glucuronic acid (Glu), ibuprofen (Ibu), and tyrosine (Tyr) were ionized as deprotonated species (carboxylate anions) by using electrons ejected from CdTe after the photoexcitation. When CuO was used as the matrix, the peak intensity of Tyr became high compared with that obtained with CdTe....

Laser desorption ionization mass spectrometry: Recent progress in matrix-free and label-assisted techniques.

Science.gov (United States)

Mandal, Arundhoti; Singha, Monisha; Addy, Partha Sarathi; Basak, Amit

2017-10-13

The MALDI-based mass spectrometry, over the last three decades, has become an important analytical tool. It is a gentle ionization technique, usually applicable to detect and characterize analytes with high molecular weights like proteins and other macromolecules. The earlier difficulty of detection of analytes with low molecular weights like small organic molecules and metal ion complexes with this technique arose due to the cluster of peaks in the low molecular weight region generated from the matrix. To detect such molecules and metal ion complexes, a four-prong strategy has been developed. These include use of alternate matrix materials, employment of new surface materials that require no matrix, use of metabolites that directly absorb the laser light, and the laser-absorbing label-assisted LDI-MS (popularly known as LALDI-MS). This review will highlight the developments with all these strategies with a special emphasis on LALDI-MS. © 2017 Wiley Periodicals, Inc.

AdS5 black holes with fermionic hair

International Nuclear Information System (INIS)

Burrington, Benjamin A.; Liu, James T.; Sabra, W. A.

2005-01-01

The study of new Bogomol'nyi-Prasad-Sommerfield (BPS) objects in AdS 5 has led to a deeper understanding of AdS/CFT. To help complete this picture, and to fully explore the consequences of the supersymmetry algebra, it is also important to obtain new solutions with bulk fermions turned on. In this paper we construct superpartners of the 1/2 BPS black hole in AdS 5 using a natural set of fermion zero modes. We demonstrate that these superpartners, carrying fermionic hair, have conserved charges differing from the original bosonic counterpart. To do so, we find the R-charge and dipole moment of the new system, as well as the mass and angular momentum, defined through the boundary stress tensor. The complete set of superpartners fits nicely into a chiral representation of AdS 5 supersymmetry, and the spinning solutions have the expected gyromagnetic ratio, g=1

Mixed-symmetry fields in AdS(5), conformal fields, and AdS/CFT

Energy Technology Data Exchange (ETDEWEB)

Metsaev, R.R. [Department of Theoretical Physics, P.N. Lebedev Physical Institute,Leninsky prospect 53, Moscow 119991 (Russian Federation)

2015-01-15

Mixed-symmetry arbitrary spin massive, massless, and self-dual massive fields in AdS(5) are studied. Light-cone gauge actions for such fields leading to decoupled equations of motion are constructed. Light-cone gauge formulation of mixed-symmetry anomalous conformal currents and shadows in 4d flat space is also developed. AdS/CFT correspondence for normalizable and non-normalizable modes of mixed-symmetry AdS fields and the respective boundary mixed-symmetry anomalous conformal currents and shadows is studied. We demonstrate that the light-cone gauge action for massive mixed-symmetry AdS field evaluated on solution of the Dirichlet problem amounts to the light-cone gauge 2-point vertex of mixed-symmetry anomalous shadow. Also we show that UV divergence of the action for mixed-symmetry massive AdS field with some particular value of mass parameter evaluated on the Dirichlet problem amounts to the action of long mixed-symmetry conformal field, while UV divergence of the action for mixed-symmetry massless AdS field evaluated on the Dirichlet problem amounts to the action of short mixed-symmetry conformal field. We speculate on string theory interpretation of a model which involves short low-spin conformal fields and long higher-spin conformal fields.

New supersymmetric AdS4 type II vacua

International Nuclear Information System (INIS)

Tsimpis, D.

2010-01-01

We review the supersymmetric AdS 4 x w M 6 backgrounds of type IIA/IIB supergravity constructed in[1]. In type IIA the supersymmetry is N=2, and the six-dimensional internal space is locally an S 2 bundle over a four-dimensional Kaehler-Einstein base; in IIB the internal space is the direct product of a circle and a five-dimensional squashed Sasaki-Einstein manifold. These backgrounds do not contain any sources, all fluxes (including the Romans mass in IIA) are generally non-zero, and the dilaton and warp factor are non-constant. The IIA solutions include the massive deformations of the IIA reduction of the eleven-dimensional AdS 4 x Y p,q solutions, and had been predicted to exist on the basis of the AdS 4 /CFT 3 correspondence. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

Gribov ambiguity in asymptotically AdS three-dimensional gravity

International Nuclear Information System (INIS)

Anabalon, Andres; Canfora, Fabrizio; Giacomini, Alex; Oliva, Julio

2011-01-01

In this paper the zero modes of the de Donder gauge Faddeev-Popov operator for three-dimensional gravity with negative cosmological constant are analyzed. It is found that the AdS 3 vacuum produces (infinitely many) normalizable smooth zero modes of the Faddeev-Popov operator. On the other hand, it is found that the Banados-Teitelboim-Zanelli black hole (including the zero mass black hole) does not generate zero modes. This differs from the usual Gribov problem in QCD where, close to the maximally symmetric vacuum, the Faddeev-Popov determinant is positive definite while 'far enough' from the vacuum it can vanish. This suggests that the zero mass Banados-Teitelboim-Zanelli black hole could be a suitable ground state of three-dimensional gravity with negative cosmological constant. Because of the kinematic origin of this result, it also applies for other covariant gravity theories in three dimensions with AdS 3 as maximally symmetric solution, such as new massive gravity and topologically massive gravity. The relevance of these results for supersymmetry breaking is pointed out.

Bulk Fields and Supersymmetry in a Slice of AdS

CERN Document Server

Gherghetta, Tony; Gherghetta, Tony; Pomarol, Alex

2000-01-01

Five-dimensional models where the bulk is a slice of AdS have the virtue of solving the hierarchy problem. The electroweak scale is generated by a ``warp'' factor of the induced metric on the brane where the standard model fields live. However, it is not necessary to confine the standard model fields on the brane and we analyze the possibility of having the fields actually living in the slice of AdS. Specifically, we study the behaviour of fermions, gauge bosons and scalars in this geometry and their implications on electroweak physics. These scenarios can provide an explanation of the fermion mass hierarchy by warp factors. We also consider the case of supersymmetry in the bulk, and analyze the conditions on the mass spectrum. Finally, a model is proposed where the warp factor generates a small (TeV) supersymmetry-breaking scale, with the gauge interactions mediating the breaking to the scalar sector.

Phosphoric acid as a matrix additive for MALDI MS analysis of phosphopeptides and phosphoproteins

DEFF Research Database (Denmark)

Kjellström, Sven; Jensen, Ole Nørregaard

2004-01-01

Phosphopeptides are often detected with low efficiency by MALDI MS analysis of peptide mixtures. In an effort to improve the phosphopeptide ion response in MALDI MS, we investigated the effects of adding low concentrations of organic and inorganic acids during peptide sample preparation in 2,5-di...... acid to 2,5-DHB were also observed in LC-MALDI-MS analysis of tryptic phosphopeptides of B. subtilis PrkC phosphoprotein. Finally, the mass resolution of MALDI mass spectra of intact proteins was significantly improved by using phosphoric acid in 2,5-DHB matrix....

Measurement of the Top Quark Mass Using the Matrix Element Technique in Dilepton Final States

CERN Document Server

Abazov, Victor Mukhamedovich

2016-08-18

We present a measurement of the top quark mass in ppbar collisions at a center-of-mass energy of 1.96 TeV at the Fermilab Tevatron collider. The data were collected by the D0 experiment corresponding to an integrated luminosity of 9.7 fb-1. The matrix element technique is applied to ttbar events in the final state containing leptons (electrons or muons) with high transverse momenta and at least two jets. The calibration of the jet energy scale determined in the lepton + jets final state of ttbar decays is applied to jet energies. This correction provides a substantial reduction in systematic uncertainties. We obtain a top quark mass of mt = 173.93 +- 1.84 GeV.

Matrix-assisted laser desorption/ionization mass spectrometric imaging for the rapid segmental analysis of methamphetamine in a single hair using umbelliferone as a matrix.

Science.gov (United States)

Wang, Hang; Wang, Ying

2017-07-04

Segmental hair analysis offers a longer period for retrospective drug detection than blood or urine. Hair is a keratinous fiber and is strongly hydrophobic. The embedding of drugs in hydrophobic hair at low concentrations makes it difficult for extraction and detection with matrix-assisted laser desorption/ionization (MALDI) coupled with mass spectrometric imaging (MSI). In this study, a single scalp hair was longitudinally cut with a cryostat section to a length of 4 mm and fixed onto a stainless steel MALDI plate. Umbelliferone was used as a new hydrophobic matrix to enrich and assist the ionization efficiency of methamphetamine in the hair sample. MALDI-Fourier transform ion cyclotron resonance (FTICR)-MS profiling and imaging were performed for direct detection and mapping of methamphetamine on the longitudinal sections of the single hair sample in positive ion mode. Using MALDI-MSI, the distribution of methamphetamine was observed throughout five longitudinally sectioned hair samples from a drug abuser. The changes of methamphetamine were also semi-quantified by comparing the ratios of methamphetamine/internal standard (I.S). This method improves the detection sensitivity of target drugs embedded in a hair matrix for imaging with mass spectrometry. The method could provide a detection level of methamphetamine down to a nanogram per milligram incorporated into hair. The results were also compared with the conventional high performance liquid chromatography -tandem mass spectrometry (HPLC-MS/MS) method. Changes in the imaging results over time by the MSI method showed good semi-quantitative correlation to the results from the HPLC-MS/MS method. This study provides a powerful tool for drug abuse control and forensic medicine analysis in a narrow time frame, and a reduction in the sample amount required. Copyright © 2017 Elsevier B.V. All rights reserved.

On modular properties of the AdS3 CFT

International Nuclear Information System (INIS)

Baron, Walter H.; Nunez, Carmen A.

2011-01-01

We study modular properties of the AdS 3 Wess-Zumino-Novikov-Witten model. Although the Euclidean partition function is modular invariant, the characters on the Euclidean torus diverge and the regularization proposed in the literature removes information on the spectrum and the usual one to one map between characters and representations of rational models is lost. Reconsidering the characters defined on the Lorentzian torus and focusing on their structure as distributions, we obtain expressions that recover those properties. We study their modular transformations and find a generalized S matrix, depending on the sign of the real modular parameters, which has two diagonal blocks and one off-diagonal block, mixing discrete and continuous representations, that we fully determine. We then explore the relations among the modular transformations, the fusion algebra and the boundary states. We explicitly construct Ishibashi states for the maximally symmetric D-branes and show that the generalized S matrix defines the one-point functions associated to pointlike and H 2 -branes as well as the fusion rules of the degenerate representations of sl(2,R) appearing in the open string spectrum of the pointlike D-branes, through a generalized Verlinde theorem.

arXiv The S-matrix Bootstrap I: QFT in AdS

CERN Document Server

Paulos, Miguel F.; Toledo, Jonathan; van Rees, Balt C.; Vieira, Pedro

2017-11-21

We propose a strategy to study massive Quantum Field Theory (QFT) using conformal bootstrap methods. The idea is to consider QFT in hyperbolic space and study correlation functions of its boundary operators. We show that these are solutions of the crossing equations in one lower dimension. By sending the curvature radius of the background hyperbolic space to infinity we expect to recover flat-space physics. We explain that this regime corresponds to large scaling dimensions of the boundary operators, and discuss how to obtain the flat-space scattering amplitudes from the corresponding limit of the boundary correlators. We implement this strategy to obtain universal bounds on the strength of cubic couplings in 2D flat-space QFTs using 1D conformal bootstrap techniques. Our numerical results match precisely the analytic bounds obtained in our companion paper using S-matrix bootstrap techniques.

Matrix-Assisted Laser Desorption Ionization Mass Spectrometry Imaging for Peptide and Protein Analyses: A Critical Review of On-Tissue Digestion

NARCIS (Netherlands)

Cillero-Pastor, B.; Heeren, R.M.A.

2013-01-01

Matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) has established itself among the plethora of mass spectrometry applications. In the biomedical field, MALDI-MSI is being more frequently recognized as a new method for the discovery of biomarkers and targets of

AdS5 magnetized solutions in minimal gauged supergravity

Directory of Open Access Journals (Sweden)

Jose Luis Blázquez-Salcedo

2017-08-01

Full Text Available We construct a generalization of the AdS charged rotating black holes with two equal magnitude angular momenta in five-dimensional minimal gauged supergravity. In addition to the mass, electric charge and angular momentum, the new solutions possess an extra-parameter associated with a non-zero magnitude of the magnetic potential at infinity. In contrast with the known cases, these new black holes possess a non-trivial zero-horizon size limit which describes a one parameter family of spinning charged solitons. All configurations reported in this work approach asymptotically an AdS5 spacetime in global coordinates and are free of pathologies.

A measurement of the top quark mass with a matrix element method

Energy Technology Data Exchange (ETDEWEB)

Gibson, Adam Paul [Univ. of California, Berkeley, CA (United States)

2006-01-01

The authors present a measurement of the mass of the top quark. The event sample is selected from proton-antiproton collisions, at 1.96 TeV center-of-mass energy, observed with the CDF detector at Fermilab's Tevatron. They consider a 318 pb^-1 dataset collected between March 2002 and August 2004. They select events that contain one energetic lepton, large missing transverse energy, exactly four energetic jets, and at least one displaced vertex b tag. The analysis uses leading-order t$\\bar{t}$ and background matrix elements along with parameterized parton showering to construct event-by-event likelihoods as a function of top quark mass. From the 63 events observed with the 318 pb^-1 dataset they extract a top quark mass of 172.0 ± 2.6(stat) ± 3.3(syst) GeV/c² from the joint likelihood. The mean expected statistical uncertainty is 3.2 GeV/c² for m $\\bar{t}$ = 178 GTeV/c² and 3.1 GeV/c² for m $\\bar{t}$ = 172.5 GeV/c². The systematic error is dominated by the uncertainty of the jet energy scale.

Finite temperature effective action, AdS5 black holes, and 1/N expansion

International Nuclear Information System (INIS)

Alvarez-Gaume, Luis; Gomez, Cesar; Liu Hong; Wadia, Spenta R.

2005-01-01

We propose a phenomenological matrix model to study string theory in AdS 5 xS 5 in the canonical ensemble. The model reproduces all the known qualitative features of the theory. In particular, it gives a simple effective potential description of Euclidean black hole nucleation and the tunneling between thermal anti-de Sitter (AdS) and the big black hole. It also has some interesting predictions. We find that there exists a critical temperature at which the Euclidean small black hole undergoes a Gross-Witten phase transition. We identify the phase transition with the Horowitz-Polchinski point where the black hole horizon size becomes comparable to the string scale. The appearance of the Hagedorn divergence of thermal AdS is due to the merger of saddle points corresponding to the Euclidean small black hole and thermal AdS. The merger can be described in terms of a cusp (A 3 ) catastrophe and divergences at the perturbative string level are smoothed out at finite string coupling using standard techniques of catastrophe theory

Rapid detection of undesired cosmetic ingredients by matrix-assisted laser desorption ionization time-of-flight mass spectrometry.

Science.gov (United States)

Ouyang, Jie; An, Dongli; Chen, Tengteng; Lin, Zhiwei

2017-10-01

In recent years, cosmetic industry profits soared due to the widespread use of cosmetics, which resulted in illicit manufacturers and products of poor quality. Therefore, the rapid and accurate detection of the composition of cosmetics has become crucial. At present, numerous methods, such as gas chromatography and liquid chromatography-mass spectrometry, were available for the analysis of cosmetic ingredients. However, these methods present several limitations, such as failure to perform comprehensive and rapid analysis of the samples. Compared with other techniques, matrix-assisted laser desorption ionization time-of-flight mass spectrometry offered the advantages of wide detection range, fast speed and high accuracy. In this article, we briefly summarized how to select a suitable matrix and adjust the appropriate laser energy. We also discussed the rapid identification of undesired ingredients, focusing on antibiotics and hormones in cosmetics.

Resistive thrust production can be as crucial as added mass mechanisms for inertial undulatory swimmers

Science.gov (United States)

Piñeirua, M.; Godoy-Diana, R.; Thiria, B.

2015-08-01

In this Rapid Communication, we address a crucial point regarding the description of moderate to high Reynolds numbers aquatic swimmers. For decades, swimming animals have been classified in two different families of propulsive mechanisms based on the Reynolds number: the resistive swimmers, using local friction to produce the necessary thrust force for locomotion at low Reynolds number, and the reactive swimmers, lying in the high Reynolds range, and using added mass acceleration (described by perfect fluid theory). However, inertial swimmers are also systems that dissipate energy, due to their finite size, therefore involving strong resistive contributions, even for high Reynolds numbers. Using a complete model for the hydrodynamic forces, involving both reactive and resistive contributions, we revisit here the physical mechanisms responsible for the thrust production of such swimmers. We show, for instance, that the resistive part of the force balance is as crucial as added mass effects in the modeling of the thrust force, especially for elongated species. The conclusions brought by this work may have significant contributions to the understanding of complex swimming mechanisms, especially for the future design of artificial swimmers.

Identifying modifications in RNA by MALDI mass spectrometry

DEFF Research Database (Denmark)

Douthwaite, Stephen; Kirpekar, Finn

2007-01-01

as RNA modifications added in cell-free in vitro systems. MALDI-MS is particularly useful in cases in which other techniques such as those involving primer extension or chromatographic analyses are not practicable. To date, MALDI-MS has been used to localize rRNA modifications that are involved......Posttranscriptional modifications on the base or sugar of ribonucleosides generally result in mass increases that can be measured by mass spectrometry. Matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) is a direct and accurate means of determining the masses of RNAs. Mass...... spectra produced by MALDI are relatively straightforward to interpret, because they are dominated by singly charged ions, making it possible to analyze complex mixtures of RNA oligonucleotides ranging from trinucleotides up to 20-mers. Analysis of modifications within much longer RNAs, such as ribosomal...

Quasi-normal modes from non-commutative matrix dynamics

Science.gov (United States)

Aprile, Francesco; Sanfilippo, Francesco

2017-09-01

We explore similarities between the process of relaxation in the BMN matrix model and the physics of black holes in AdS/CFT. Focusing on Dyson-fluid solutions of the matrix model, we perform numerical simulations of the real time dynamics of the system. By quenching the equilibrium distribution we study quasi-normal oscillations of scalar single trace observables, we isolate the lowest quasi-normal mode, and we determine its frequencies as function of the energy. Considering the BMN matrix model as a truncation of N=4 SYM, we also compute the frequencies of the quasi-normal modes of the dual scalar fields in the AdS5-Schwarzschild background. We compare the results, and we finda surprising similarity.

Matrix interference evaluation employing GC and LC coupled to triple quadrupole tandem mass spectrometry.

Science.gov (United States)

Uclés, S; Lozano, A; Sosa, A; Parrilla Vázquez, P; Valverde, A; Fernández-Alba, A R

2017-11-01

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. The aim of this analytical study is to provide a framework for evaluating the maximum expected errors associated with the matrix effects. The worst-case study contrived to give an estimation of the extreme errors caused by matrix effects when extraction/determination protocols are applied in routine multiresidue analysis. Twenty-five different blank matrices extracted with the four most common extraction methods used in routine analysis (citrate QuEChERS with/without PSA clean-up, ethyl acetate and the Dutch mini-Luke "NL" methods) were evaluated by both GC-QqQ-MS/MS and LC-QqQ-MS/MS. The results showed that the presence of matrix compounds with isobaric transitions to target pesticides was higher in GC than under LC in the experimental conditions tested. In a second study, the number of "potential" false negatives was evaluated. For that, ten matrices with higher percentages of natural interfering components were checked. Additionally, the results showed that for more than 90% of the cases, pesticide quantification was not affected by matrix-matched standard calibration when an interferent was kept constant along the calibration curve. The error in quantification depended on the concentration level. In a

Phenotypic identification of Porphyromonas gingivalis validated with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry

NARCIS (Netherlands)

Rams, Thomas E; Sautter, Jacqueline D; Getreu, Adam; van Winkelhoff, Arie J

OBJECTIVE: Porphyromonas gingivalis is a major bacterial pathogen in human periodontitis. This study used matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry to assess the accuracy of a rapid phenotypic identification scheme for detection of cultivable P.

Freedom in electroweak symmetry breaking and mass matrix of fermions in dimensional deconstruction model

International Nuclear Information System (INIS)

Nojiri, Shin'ichi; Odintsov, Sergei D.; Sugamoto, Akio

2004-01-01

There exists a freedom in a class of four-dimensional electroweak theories proposed by Arkani-Hamed et al. relying on deconstruction and Coleman-Weinberg mechanism. The freedom comes from the winding modes of the link variable (Wilson operator) connecting non-nearest neighbours in the discrete fifth dimension. Using this freedom, dynamical breaking of SU(2) gauge symmetry, mass hierarchy patterns of fermions and Cabbibo-Kobayashi-Maskawa matrix may be obtained

Direct Surface Analysis of Fungal Species by Matrix-assisted Laser Desorption/Ionization Mass Spectrometry

Energy Technology Data Exchange (ETDEWEB)

Valentine, Nancy B.(BATTELLE (PACIFIC NW LAB)); Wahl, Jon H.(BATTELLE (PACIFIC NW LAB)); Kingsley, Mark T.(BATTELLE (PACIFIC NW LAB)); Wahl, Karen L.(BATTELLE (PACIFIC NW LAB))

2001-12-01

Intact spores and/or hyphae of Aspergillus niger, Rhizopus oryzae, Trichoderma reesei and Phanerochaete chrysosporium are analyzed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). This study investigates various methods of sample preparation and matrices to determine optimum collection and analysis criteria for fungal analysis by MALDI-MS. Fungi are applied to the MALDI sample target as untreated, sonicated, acid/heat treated, or blotted directly from the fungal culture with double-stick tape. Ferulic acid or sinapinic acid matrix solution is layered over the dried samples and analyzed by MALDI-MS. Statistical analysis of the data show that simply using double stick tape to collect and transfer to a MALDI sample plate typically worked as well as the other preparation methods, but requires the least sample handling.

[Special application of matrix-assisted laser desorption ionization time-of-flight mass spectrometry in clinical microbiological diagnostics].

Science.gov (United States)

Nagy, Erzsébet; Abrók, Marianna; Bartha, Noémi; Bereczki, László; Juhász, Emese; Kardos, Gábor; Kristóf, Katalin; Miszti, Cecilia; Urbán, Edit

2014-09-21

Matrix-assisted laser desorption ionization time-of-flight mass spectrometry as a new possibility for rapid identification of bacteria and fungi revolutionized the clinical microbiological diagnostics. It has an extreme importance in the routine microbiological laboratories, as identification of the pathogenic species rapidly will influence antibiotic selection before the final determination of antibiotic resistance of the isolate. The classical methods for identification of bacteria or fungi, based on biochemical tests, are influenced by many environmental factors. The matrix-assisted laser desorption ionization time-of-flight mass spectrometry is a rapid method which is able to identify a great variety of the isolated bacteria and fungi based on the composition of conserved ribosomal proteins. Recently several other applications of the method have also been investigated such as direct identification of pathogens from the positive blood cultures. There are possibilities to identify bacteria from the urine samples in urinary tract infection or from other sterile body fluids. Using selective enrichment broth Salmonella sp from the stool samples can be identified more rapidly, too. The extended spectrum beta-lactamase or carbapenemase production of the isolated bacteria can be also detected by this method helping the antibiotic selection in some cases. Matrix-assisted laser desorption ionization time-of-flight mass spectrometry based methods are suitable to investigate changes in deoxyribonucleic acid or ribonucleic acid, to carry out rapid antibiotic resistance determination or other proteomic analysis. The aim of this paper is to give an overview about present possibilities of using this technique in the clinical microbiological routine procedures.

Influence of locational states of submicron fibers added into matrix on mechanical properties of plain-woven Carbon Fiber Composite

Directory of Open Access Journals (Sweden)

Kumamoto Soichiro

2016-01-01

Full Text Available The aim of this study was to show the influence of locational states of submicron fibers added into epoxy matrix on mechanical properties of modified plane-woven carbon fiber reinforced plastic (CFRP. To change the locational states of submicron fibers, two kinds of fabrication processes were applied in preparing specimen by hand lay-up method. Submicron fibers were simply added into epoxy resin with ethanol after they were stirred by a dispersion process using homogenizer to be located far from the interface between reinforcement and matrix. In contrast, submicron fibers were attached onto the carbon fibers by injecting from a spray nozzle accompanying with ethanol to be located near the interface, after they were tentatively contained in ethanol. The plain-woven CFRP plates were fabricated by hand lay-up method and cured at 80 degree-C for 1 hour and then at 150 degree-C for 3 hours. After curing, the plain-woven CFRP plates were cut into the dimension of specimen. Tensile shear strength and Mode-II fracture toughness of CFRP were determined by tensile lap-shear test and End-notched flexure(ENF test, respectively. When submicron fibers were located far from the interface between carbon fibers and epoxy resin, tensile shear strength and Mode-II fracture toughness of CFRP were improved 30% and 18% compared with those of unmodified case. The improvement ratio in modified case was rather low (about few percentages in the case where submicron fibers were located near the interface. The result suggested that crack propagation should be prevented when submicron fibers were existed far from the interface due to the effective stress state around the crack tip.

Hippocampal lipid differences in Alzheimer's disease: a human brain study using matrix?assisted laser desorption/ionization?imaging mass spectrometry

OpenAIRE

Mendis, Lakshini H. S.; Grey, Angus C.; Faull, Richard L. M.; Curtis, Maurice A.

2016-01-01

Abstract Introduction Alzheimer's disease (AD), the leading cause of dementia, is pathologically characterized by ??amyloid plaques and tau tangles. However, there is also evidence of lipid dyshomeostasis?mediated AD pathology. Given the structural diversity of lipids, mass spectrometry is a useful tool for studying lipid changes in AD. Although there have been a few studies investigating lipid changes in the human hippocampus in particular, there are few reports on how lipids change in each ...

Matrix effect on the determination of synthetic corticosteroids and diuretics by liquid chromatography-tandem mass spectrometry

Science.gov (United States)

Dikunets, M. A.; Appolonova, S. A.; Rodchenkov, G. M.

2009-04-01

This work presents a high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) procedure for selective and reliable screening of corticosteroids and diuretics in human urine. Sample preparation included the extraction, evaporation of the organic extract under nitrogen, and solution of the dry residue. The extract was analyzed by HPLC combined with tandem mass spectrometry using electro-spraying ionization at atmospheric pressure with negative ion recording. The mass spectra of all compounds were recorded, and the characteristic ions, retention times, and detection limits were determined. The procedure was validated by evaluating the degree of the matrix suppression of ionization, extraction of analytes from human biological liquid, and the selectivity and specificity of determination.

One-point functions in AdS/dCFT from matrix product states

International Nuclear Information System (INIS)

Buhl-Mortensen, Isak; Leeuw, Marius de; Kristjansen, Charlotte; Zarembo, Konstantin

2016-01-01

One-point functions of certain non-protected scalar operators in the defect CFT dual to the D3-D5 probe brane system with k units of world volume flux can be expressed as overlaps between Bethe eigenstates of the Heisenberg spin chain and a matrix product state. We present a closed expression of determinant form for these one-point functions, valid for any value of k. The determinant formula factorizes into the k=2 result times a k-dependent pre-factor. Making use of the transfer matrix of the Heisenberg spin chain we recursively relate the matrix product state for higher even and odd k to the matrix product state for k=2 and k=3 respectively. We furthermore find evidence that the matrix product states for k=2 and k=3 are related via a ratio of Baxter’s Q-operators. The general k formula has an interesting thermodynamical limit involving a non-trivial scaling of k, which indicates that the match between string and field theory one-point functions found for chiral primaries might be tested for non-protected operators as well. We revisit the string computation for chiral primaries and discuss how it can be extended to non-protected operators.

Matrix-assisted laser desorption/ionisation mass spectrometry imaging and its development for plant protein imaging

Directory of Open Access Journals (Sweden)

Millar A Harvey

2011-07-01

Full Text Available Abstract Matrix-Assisted Laser Desorption/Ionisation (MALDI mass spectrometry imaging (MSI uses the power of high mass resolution time of flight (ToF mass spectrometry coupled to the raster of lasers shots across the cut surface of tissues to provide new insights into the spatial distribution of biomolecules within biological tissues. The history of this technique in animals and plants is considered and the potential for analysis of proteins by this technique in plants is discussed. Protein biomarker identification from MALDI-MSI is a challenge and a number of different approaches to address this bottleneck are discussed. The technical considerations needed for MALDI-MSI are reviewed and these are presented alongside examples from our own work and a protocol for MALDI-MSI of proteins in plant samples.

Generalized ℤ 2 × ℤ 2 in scaling neutrino Majorana mass matrix and baryogenesis via flavored leptogenesis

Science.gov (United States)

Sinha, Roopam; Samanta, Rome; Ghosal, Ambar

2017-12-01

We investigate the consequences of a generalized ℤ 2 × ℤ 2 symmetry on a scaling neutrino Majorana mass matrix. It enables us to determine definite analytical relations between the mixing angles θ 12 and θ 13, maximal CP violation for the Dirac type and vanishing for the Majorana type. Beside the other testable predictions on the low energy neutrino parameters such as ββ 0ν decay matrix element | M ee | and the light neutrino masses m 1,2,3, the model also has intriguing consequences from the perspective of leptogenesis. With the assumption that the required CP violation for leptogenesis is created by the decay of lightest ( N 1) of the heavy Majorana neutrinos, only τ -flavored leptogenesis scenario is found to be allowed in this model. For a normal (inverted) ordering of light neutrino masses, θ 23 is found be less (greater) than its maximal value, for the final baryon asymmetry Y B to be in the observed range. Besides, an upper and a lower bound on the mass of N 1 have also been estimated. Effect of the heavier neutrinos N 2,3 on final Y B has been worked out subsequently. The predictions of this model will be tested in the experiments such as nEXO, LEGEND, GERDA-II, T2K, NO νA, DUNE etc.

Gravitational charges of transverse asymptotically AdS spacetimes

International Nuclear Information System (INIS)

Cebeci, Hakan; Sarioglu, Oezguer; Tekin, Bayram

2006-01-01

Using Killing-Yano symmetries, we construct conserved charges of spacetimes that asymptotically approach to the flat or anti-de Sitter spaces only in certain directions. In D dimensions, this allows one to define gravitational charges (such as mass and angular momenta densities) of p-dimensional branes/solitons or any other extended objects that curve the transverse space into an asymptotically flat or AdS one. Our construction answers the question of what kind of charges the antisymmetric Killing-Yano tensors lead to

AdS gravity and the scalar glueball spectrum

Energy Technology Data Exchange (ETDEWEB)

Vento, Vicente [Departament de Fisica Teorica, Universitat de Valencia y Institut de Fisica Corpuscular, Consejo Superior de Investigaciones Cientificas, Burjassot (Valencia) (Spain)

2017-09-15

The scalar glueball spectrum has attracted much attention since the formulation of Quantum Chromodynamics. Different approaches give very different results for the glueball masses. We revisit the problem from the perspective of the AdS/CFT correspondence. (orig.)

In Situ Analysis of Bacterial Lipopeptide Antibiotics by Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry Imaging.

Science.gov (United States)

Debois, Delphine; Ongena, Marc; Cawoy, Hélène; De Pauw, Edwin

2016-01-01

Matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI MSI) is a technique developed in the late 1990s enabling the two-dimensional mapping of a broad variety of biomolecules present at the surface of a sample. In many applications including pharmaceutical studies or biomarker discovery, the distribution of proteins, lipids or drugs, and metabolites may be visualized within tissue sections. More recently, MALDI MSI has become increasingly applied in microbiology where the versatility of the technique is perfectly suited to monitor the metabolic dynamics of bacterial colonies. The work described here is focused on the application of MALDI MSI to map secondary metabolites produced by Bacilli, especially lipopeptides, produced by bacterial cells during their interaction with their environment (bacteria, fungi, plant roots, etc.). This chapter addresses the advantages and challenges that the implementation of MALDI MSI to microbiological samples entails, including detailed protocols on sample preparation (from both microbiologist and mass spectrometrist points of view), matrix deposition, and data acquisition and interpretation. Lipopeptide images recorded from confrontation plates are also presented.

Effect of a new matrix system for low-polar organic compounds in fast atom bombardment mass spectrometry

International Nuclear Information System (INIS)

Takayama, Mitsuo; Fukai, Toshio; Nomura, Taro

1988-01-01

A new matrix system m-NBA-DTDE (1:1) for FABMS of low-polar compounds, such as cholesterol and stearic acid methyl ester, was prepared. The system, i.e., a 1:1 mixture of m-NBA (m-nitrobenzyl alcohol) to DTDE (2,2-dithiodiethanol or 2-hydroxyethyl disulfide), contributed to measuring the positive ion FAB mass spectra of above compounds and morusin permethyl ether, and it brought an effective result on the ion current lifetime and the reproducibility of their spectra. The positive ion FAB mass spectra of these low-polar compounds were compared with the corresponding positive ion EI and CI mass spectra. (author)

Detection of Bacteriocins by Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry

OpenAIRE

Rose, Natisha L.; Sporns, Peter; McMullen, Lynn M.

1999-01-01

The use of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) for the detection of bacteriocins was investigated. A 30-s water wash of the sample on the MALDI-TOF MS probe was effective in removing contaminants of the analyte. This method was used for rapid detection of nisin, pediocin, brochocin A and B, and enterocin A and B from culture supernatants and for detection of enterocin B throughout its purification.

Position and mass determination of multiple particles using cantilever based mass sensors

International Nuclear Information System (INIS)

Dohn, Soeren; Schmid, Silvan; Boisen, Anja; Amiot, Fabien

2010-01-01

Resonant microcantilevers are highly sensitive to added masses and have the potential to be used as mass-spectrometers. However, making the detection of individual added masses quantitative requires the position determination for each added mass. We derive expressions relating the position and mass of several added particles to the resonant frequencies of a cantilever, and an identification procedure valid for particles with different masses is proposed. The identification procedure is tested by calculating positions and mass of multiple microparticles with similar mass positioned on individual microcantilevers. Excellent agreement is observed between calculated and measured positions and calculated and theoretical masses.

Aspects of matrix effects in applications of liquid chromatography-mass spectrometry to forensic and clinical toxicology--a review.

Science.gov (United States)

Peters, Frank T; Remane, Daniela

2012-06-01

In the last decade, liquid chromatography coupled to (tandem) mass spectrometry (LC-MS(-MS)) has become a versatile technique with many routine applications in clinical and forensic toxicology. However, it is well-known that ionization in LC-MS(-MS) is prone to so-called matrix effects, i.e., alteration in response due to the presence of co-eluting compounds that may increase (ion enhancement) or reduce (ion suppression) ionization of the analyte. Since the first reports on such matrix effects, numerous papers have been published on this matter and the subject has been reviewed several times. However, none of the existing reviews has specifically addressed aspects of matrix effects of particular interest and relevance to clinical and forensic toxicology, for example matrix effects in methods for multi-analyte or systematic toxicological analysis or matrix effects in (alternative) matrices almost exclusively analyzed in clinical and forensic toxicology, for example meconium, hair, oral fluid, or decomposed samples in postmortem toxicology. This review article will therefore focus on these issues, critically discussing experiments and results of matrix effects in LC-MS(-MS) applications in clinical and forensic toxicology. Moreover, it provides guidance on performance of studies on matrix effects in LC-MS(-MS) procedures in systematic toxicological analysis and postmortem toxicology.

Black hole formation in AdS Einstein-Gauss-Bonnet gravity

Energy Technology Data Exchange (ETDEWEB)

Deppe, Nils [Cornell Center for Astrophysics and Planetary Science andDepartment of Physics, Cornell University,122 Sciences Drive, Ithaca, New York 14853 (United States); Kolly, Allison [Department of Atmospheric and Oceanic Sciences, McGill University,805 Sherbrooke Street West, Montréal, Québec H3A 0B9 (Canada); Frey, Andrew R.; Kunstatter, Gabor [Department of Physics and Winnipeg Institute for Theoretical Physics, University of Winnipeg,515 Portage Avenue, Winnipeg, Manitoba R3B 2E9 (Canada)

2016-10-17

AdS spacetime has been shown numerically to be unstable against a large class of arbitrarily small perturbations. In http://dx.doi.org/10.1103/PhysRevLett.114.071102, the authors presented a preliminary study of the effects on stability of changing the local dynamics by adding a Gauss-Bonnet term to the Einstein action. Here we provide further details as well as new results with improved numerical methods. In particular, we elucidate new structure in Choptuik scaling plots. We also provide evidence of chaotic behavior at the transition between immediate horizon formation and horizon formation after the matter pulse reflects from the AdS conformal boundary. Finally, we present data suggesting the formation of naked singularities in spacetimes with ADM mass below the algebraic bound for black hole formation.

Membranes from monopole operators in ABJM theory: Large angular momentum and M-theoretic AdS4/CFT3

International Nuclear Information System (INIS)

Kovacs, Stefano; Sato, Yuki; Shimada, Hidehiko

2014-01-01

We study the duality between M-theory in AdS 4 ×S 7 /ℤ k and the ABJM N=6 Chern–Simons-matter theory with gauge group U(N)×U(N) and level k, taking N large and k of order 1. In this M-theoretic regime the lack of an explicit formulation of M-theory in AdS 4 ×S 7 /ℤ k makes the gravity side difficult, while the CFT is strongly coupled and the planar approximation is not applicable. We focus on states on the gravity side with large angular momentum J≫1 associated with a single plane of rotation in S 7 and identify their dual operators in the CFT. We show that natural approximation schemes arise on both sides thanks to the presence of the small parameter 1/J. On the AdS side, we use the matrix model of M-theory on the maximally supersymmetric pp-wave background with matrices of size J/k. A perturbative treatment of this matrix model provides a good approximation to M-theory in AdS 4 ×S 7 /ℤ k when N 1/3 ≪J≪N 1/2 . On the CFT side, we study the theory on S 2 ×ℝ with magnetic flux J/k. A Born–Oppenheimer-type expansion arises naturally for large J in spite of the theory being strongly coupled. The energy spectra on the two sides agree at leading order. This provides a non-trivial test of the AdS 4 /CFT 3 correspondence including near-BPS observables associated with membrane degrees of freedom, thus verifying the duality beyond the previously studied sectors corresponding to either BPS observables or the type IIA string regime

Benefits of 2.94 μm infrared matrix-assisted laser desorption/ionization for analysis of labile molecules by Fourier transform mass spectrometry

DEFF Research Database (Denmark)

Budnik, Bogdan A.; Jensen, Kenneth Bendix; Jørgensen, Thomas J. D.

2000-01-01

A 2.94 microm Er:YAG laser was used together with a commercial Fourier transform mass spectrometer to study labile biomolecules. The combination has shown superior performance over conventional 337 nm ultraviolet matrix-assisted laser desorption/ionization (UV-MALDI) Fourier transform mass...

Towards a canonical Fermi mass matrix for a pure generation structure

International Nuclear Information System (INIS)

Davidson, A.; Wali, K.C.

1981-01-01

Vertical constraints on the horizontal generation structure are discussed. The minimal electro/nuclear scheme for which the generation structure must be pure is identified to be the partially unified Pati-Salam SU(4)sub(C)xSU(2)sub(L)xSU(2)sub(R). SO(10) type unification furthermore requires the horizontal group factor to be axial. This in turn crucially affects the Yukawa couplings in such a way that a minimal Higgs system with oply two conventional scalars is capable of uniquely giving rise to the 'canonical' Fritzsch-type mass matrix, for any arbitrary number of fermionic families. The anomaly free equations then provide the desired one-to-one correspondence between the mass matrices in the two charged quark sectors. The derived horizontal quantum numbers suggest that the maximal horizontal group factor be SU(2), with the generations furnishing two neighbor j and j + 1/2 representations. Finally a careful phase analysis shows that the tree-level soft and superweak CP-violation solely reflects the non-Abelian character of the horizontal group, representing an induced internal rotation which is triggered by the phase elimination performed in the vertical sector. (author)

Characterization of polyesters by matrix-assisted laser desorption/ionization and Fourier transform mass spectrometry.

Science.gov (United States)

Mize, Todd H; Simonsick, William J; Amster, I Jonathan

2003-01-01

Two homopolyesters, poly(neopentyl glycol-alt-isophthalic acid) and poly(hexanediol-alt-azelaic acid), and two copolyesters, poly(dipropoxylated bisphenol-A-alt-(isophthalic acid-co-adipic acid)) and poly(neopentyl glycol-alt-(adipic acid-co-isophthalic acid)) were analyzed by internal source matrix assisted laser desorption/ionization Fourier transform mass spectrometry (MALDI-FTMS). The high resolution and high mass accuracy provided by FTMS greatly facilitate the characterization of the polyester and copolyester samples. Isobaric resolution allows the ion abundances of overlapping isotopic envelopes to be assessed. Repeat units were confirmed and end functionality assigned. Single shot mass spectra of the entire polymeric distribution demonstrate that the dynamic range of this internal MALDI source instrument and the analyzer cell exceeds performance of those previously reported for higher field instruments. Corrections of space charge mass shift effects are demonstrated for the analytes using an external calibrant and (subsequent to confirmation of structure) via internal calibration which removes ambiguity due to space charge differences in calibrant and analyte spectra. Capillary gel permeation chromatography was used to prepare low polydispersity samples from a high polydispersity polyester, improving the measurement of molecular weight distribution two-fold while retaining the benefits of high resolution mass spectrometry for elucidation of oligomer identity.

Development of matrix-assisted laser desorption ionization-mass spectrometry imaging (MALDI-MSI) for plant metabolite analysis

Energy Technology Data Exchange (ETDEWEB)

Korte, Andrew R [Iowa State Univ., Ames, IA (United States)

2014-12-01

This thesis presents efforts to improve the methodology of matrix-assisted laser desorption ionization-mass spectrometry imaging (MALDI-MSI) as a method for analysis of metabolites from plant tissue samples. The first chapter consists of a general introduction to the technique of MALDI-MSI, and the sixth and final chapter provides a brief summary and an outlook on future work.

Enthalpy and the mechanics of AdS black holes

International Nuclear Information System (INIS)

Kastor, David; Traschen, Jennie; Ray, Sourya

2009-01-01

We present geometric derivations of the Smarr formula for static AdS black holes and an expanded first law that includes variations in the cosmological constant. These two results are further related by a scaling argument based on Euler's theorem. The key new ingredient in the constructions is a two-form potential for the static Killing field. Surface integrals of the Killing potential determine the coefficient of the variation of Λ in the first law. This coefficient is proportional to a finite, effective volume for the region outside the AdS black hole horizon, which can also be interpreted as minus the volume excluded from a spatial slice by the black hole horizon. This effective volume also contributes to the Smarr formula. Since Λ is naturally thought of as a pressure, the new term in the first law has the form of effective volume times change in pressure that arises in the variation of the enthalpy in classical thermodynamics. This and related arguments suggest that the mass of an AdS black hole should be interpreted as the enthalpy of the spacetime.

The nuclear reaction matrix

International Nuclear Information System (INIS)

Krenciglowa, E.M.; Kung, C.L.; Kuo, T.T.S.; Osnes, E.; and Department of Physics, State University of New York at Stony Brook, Stony Brook, New York 11794)

1976-01-01

Different definitions of the reaction matrix G appropriate to the calculation of nuclear structure are reviewed and discussed. Qualitative physical arguments are presented in support of a two-step calculation of the G-matrix for finite nuclei. In the first step the high-energy excitations are included using orthogonalized plane-wave intermediate states, and in the second step the low-energy excitations are added in, using harmonic oscillator intermediate states. Accurate calculations of G-matrix elements for nuclear structure calculations in the Aapprox. =18 region are performed following this procedure and treating the Pauli exclusion operator Q 2 /sub p/ by the method of Tsai and Kuo. The treatment of Q 2 /sub p/, the effect of the intermediate-state spectrum and the energy dependence of the reaction matrix are investigated in detail. The present matrix elements are compared with various matrix elements given in the literature. In particular, close agreement is obtained with the matrix elements calculated by Kuo and Brown using approximate methods

Evaluation of matrix-assisted laser desorption/ionization time of flight mass spectrometry for the identification of ceratopogonid and culicid larvae.

Science.gov (United States)

Steinmann, I C; Pflüger, V; Schaffner, F; Mathis, A; Kaufmann, C

2013-03-01

Matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF MS) was evaluated for the rapid identification of ceratopogonid larvae. Optimal sample preparation as evaluated with laboratory-reared biting midges Culicoides nubeculosus was the homogenization of gut-less larvae in 10% formic acid, and analysis of 0.2 mg/ml crude protein homogenate mixed with SA matrix at a ratio of 1:1.5. Using 5 larvae each of 4 ceratopogonid species (C. nubeculosus, C. obsoletus, C. decor, and Dasyhelea sp.) and of 2 culicid species (Aedes aegypti, Ae. japonicus), biomarker mass sets between 27 and 33 masses were determined. In a validation study, 67 larvae belonging to the target species were correctly identified by automated database-based identification (91%) or manual full comparison (9%). Four specimens of non-target species did not yield identification. As anticipated for holometabolous insects, the biomarker mass sets of adults cannot be used for the identification of larvae, and vice versa, because they share only very few similar masses as shown for C. nubeculosus, C. obsoletus, and Ae. japonicus. Thus, protein profiling by MALDI-TOF as a quick, inexpensive and accurate alternative tool is applicable to identify insect larvae of vector species collected in the field.

Impact vibration analysis of group of hexagonal bars immersed in liquid

International Nuclear Information System (INIS)

Horiuchi, Toshihiko

1994-01-01

A simulation method was studied to calculate the vibration response during seismic excitation of a group of hexagonal bars installed in a restraint immersed in liquid. In this study, the influence of fluid force on structural motion was modeled using an added mass matrix. The added mass matrix was then transferred into the space composed of the eigen modes of hexagonal bars without the added mass and introduced into eigenvalue analysis of the whole bar group structure. By means of this method, the computational time of the added mass matrix calculation and the eigenvalue analysis can be reduced. It was shown that the proposed method yielded almost the same eigenvalues as the conventional method in the physical space. Using the proposed method, added mass models to be used in the impact vibration analysis were investigated. Comparing the calculated results by the proposed method with those using a concentrated added mass, which is a simplified model, showed that the concentrated added mass can be used for a rough response calculation, although the precise calculation requires the added mass matrix. (author)

Fully developed natural convection heat and mass transfer in a vertical annular porous medium with asymmetric wall temperatures and concentrations

International Nuclear Information System (INIS)

Cheng, C.-Y.

2006-01-01

This work examines the effects of the modified Darcy number, the buoyancy ratio and the inner radius-gap ratio on the fully developed natural convection heat and mass transfer in a vertical annular non-Darcy porous medium with asymmetric wall temperatures and concentrations. The exact solutions for the important characteristics of fluid flow, heat transfer, and mass transfer are derived by using a non-Darcy flow model. The modified Darcy number is related to the flow resistance of the porous matrix. For the free convection heat and mass transfer in an annular duct filled with porous media, increasing the modified Darcy number tends to increase the volume flow rate, total heat rate added to the fluid, and the total species rate added to the fluid. Moreover, an increase in the buoyancy ratio or in the inner radius-gap ratio leads to an increase in the volume flow rate, the total heat rate added to the fluid, and the total species rate added to the fluid

MoS_2/Ag nanohybrid: A novel matrix with synergistic effect for small molecule drugs analysis by negative-ion matrix-assisted laser desorption/ionization time-of-flight mass spectrometry

International Nuclear Information System (INIS)

Zhao, Yaju; Deng, Guoqing; Liu, Xiaohui; Sun, Liang; Li, Hui; Cheng, Quan; Xi, Kai; Xu, Danke

2016-01-01

This paper reports a facile synthesis of molybdenum disulfide nanosheets/silver nanoparticles (MoS_2/Ag) hybrid and its use as an effective matrix in negative ion matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). The nanohybrid exerts a strong synergistic effect, leading to high performance detection of small molecule analytes including amino acids, peptides, fatty acids and drugs. The enhancement of laser desorption/ionization (LDI) efficiency is largely attributed to the high surface roughness and large surface area for analyte adsorption, better dispersibility, increased thermal conductivity and enhanced UV energy absorption as compared to pure MoS_2. Moreover, both Ag nanoparticles and the edge of the MoS_2 layers function as deprotonation sites for proton capture, facilitating the charging process in negative ion mode and promoting formation of negative ions. As a result, the MoS_2/Ag nanohybrid proves to be a highly attractive matrix in MALDI-TOF MS, with desired features such as high desorption/ionization efficiency, low fragmentation interference, high salt tolerance, and no sweet-spots for mass signal. These characteristic properties allowed for simultaneous analysis of eight different drugs and quantification of acetylsalicylic acid in the spiked human serum. This work demonstrates for the first time the fabrication and application of a novel MoS_2/Ag hybrid, and provides a new platform for use in the rapid and high throughput analysis of small molecules by mass spectrometry. - Highlights: • MoS_2/Ag nanohybrid was applied as a novel matrix in negative-ion MALDI-TOF MS. • The MoS_2/Ag nanohybrid exerted synergistic effect on the detection of small molecules. • The MoS_2/Ag nanohybrid showed good signal reproducibility and low background interferences comparing to organic matrices. • MoS_2/Ag allows simultaneous analysis of multiple drugs and quantification of acetylsalicylic acid in spiked serum samples.

Partition functions in even dimensional AdS via quasinormal mode methods

International Nuclear Information System (INIS)

Keeler, Cynthia; Ng, Gim Seng

2014-01-01

In this note, we calculate the one-loop determinant for a massive scalar (with conformal dimension Δ) in even-dimensional AdS d+1 space, using the quasinormal mode method developed in http://dx.doi.org/10.1088/0264-9381/27/12/125001 by Denef, Hartnoll, and Sachdev. Working first in two dimensions on the related Euclidean hyperbolic plane H 2 , we find a series of zero modes for negative real values of Δ whose presence indicates a series of poles in the one-loop partition function Z(Δ) in the Δ complex plane; these poles contribute temperature-independent terms to the thermal AdS partition function computed in http://dx.doi.org/10.1088/0264-9381/27/12/125001. Our results match those in a series of papers by Camporesi and Higuchi, as well as Gopakumar et al. http://dx.doi.org/10.1007/JHEP11(2011)010 and Banerjee et al. http://dx.doi.org/10.1007/JHEP03(2011)147. We additionally examine the meaning of these zero modes, finding that they Wick-rotate to quasinormal modes of the AdS 2 black hole. They are also interpretable as matrix elements of the discrete series representations of SO(2,1) in the space of smooth functions on S 1 . We generalize our results to general even dimensional AdS 2n , again finding a series of zero modes which are related to discrete series representations of SO(2n,1), the motion group of H 2n .

Rapid Identification of Intact Staphylococcal Bacteriophages Using Matrix-Assisted Laser Desorption Ionization-Time-of-Flight Mass Spectrometry

Directory of Open Access Journals (Sweden)

Dana Štveráková

2018-04-01

Full Text Available Staphylococcus aureus is a major causative agent of infections associated with hospital environments, where antibiotic-resistant strains have emerged as a significant threat. Phage therapy could offer a safe and effective alternative to antibiotics. Phage preparations should comply with quality and safety requirements; therefore, it is important to develop efficient production control technologies. This study was conducted to develop and evaluate a rapid and reliable method for identifying staphylococcal bacteriophages, based on detecting their specific proteins using matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS profiling that is among the suggested methods for meeting the regulations of pharmaceutical authorities. Five different phage purification techniques were tested in combination with two MALDI-TOF MS matrices. Phages, either purified by CsCl density gradient centrifugation or as resuspended phage pellets, yielded mass spectra with the highest information value if ferulic acid was used as the MALDI matrix. Phage tail and capsid proteins yielded the strongest signals whereas the culture conditions had no effect on mass spectral quality. Thirty-seven phages from Myoviridae, Siphoviridae or Podoviridae families were analysed, including 23 siphophages belonging to the International Typing Set for human strains of S. aureus, as well as phages in preparations produced by Microgen, Bohemia Pharmaceuticals and MB Pharma. The data obtained demonstrate that MALDI-TOF MS can be used to effectively distinguish between Staphylococcus-specific bacteriophages.

Pigments and proteins in green bacterial chlorosomes studied by matrix-assisted laser desorption ionization mass spectrometry

DEFF Research Database (Denmark)

Persson, S; Sönksen, C P; Frigaard, N U

2000-01-01

We have used matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS) for mass determination of pigments and proteins in chlorosomes, the light-harvesting organelles from the photosynthetic green sulfur bacterium Chlorobium tepidum. By applying a small volume (1...... microL) of a concentrated suspension of isolated chlorosomes directly to the target of the mass spectrometer we have been able to detect bacteriochlorophyll a and all the major homologs of bacteriochlorophyll c. The peak heights of the different bacteriochlorophyll c homologs in the MALDI spectra were...... proportional to peak areas obtained from HPLC analysis of the same sample. The same result was also obtained when whole cells of Chl. tepidum were applied to the target, indicating that MALDI-MS can provide a rapid method for obtaining a semiquantitative determination or finger-print of the bacteriochlorophyll...

Higher Daily Energy Expenditure and Respiratory Quotient, Rather Than Fat-Free Mass, Independently Determine Greater ad Libitum Overeating.

Science.gov (United States)

Piaggi, Paolo; Thearle, Marie S; Krakoff, Jonathan; Votruba, Susanne B

2015-08-01

Body fat-free mass (FFM), energy expenditure (EE), and respiratory quotient (RQ) are known predictors of daily food intake. Because FFM largely determines EE, it is unclear whether body composition per se or the underlying metabolism drives dietary intake. The objective of the study was to test whether 24-hour measures of EE and RQ and their components influence ad libitum food intake independently of FFM. One hundred seven healthy individuals (62 males/45 females, 84 Native Americans/23 whites; age 33 ± 8 y; body mass index 33 ± 8 kg/m(2); body fat 31% ± 8%) had 24-hour measures of EE in a whole-room indirect calorimeter during energy balance, followed by 3 days of ad libitum food intake using computerized vending machine systems. Body composition was estimated by dual-energy x-ray absorptiometry. FFM, 24-hour EE, RQ, spontaneous physical activity, sleeping EE (sleeping metabolic rate), awake and fed thermogenesis, and ad libitum food intake (INTAKE) were measured. Higher 24-hour RQ (P FFM (P = .65), were independent predictors of INTAKE. Mediation analysis demonstrated that 24-hour EE is responsible for 80% of the FFM effect on INTAKE (44.5 ± 16.9 kcal ingested per kilogram of FFM, P= .01), whereas the unique effect due to solely FFM was negligible (10.6 ± 23.2, P = .65). Spontaneous physical activity (r = 0.33, P = .001), but not sleeping metabolic rate (P = .71), positively predicted INTAKE, whereas higher awake and fed thermogenesis determined greater INTAKE only in subjects with a body mass index of 29 kg/m(2) or less (r = 0.44, P = .01). EE and RQ, rather than FFM, independently determine INTAKE, suggesting that competitive energy-sensing mechanisms driven by the preferential macronutrient oxidation and total energy demands may regulate food intake.

Leptonic CP violation phases using an ansatz for the neutrino mass matrix and application to leptogenesis

International Nuclear Information System (INIS)

Nasri, Salah; Schechter, Joseph; Moussa, Sherif

2004-01-01

We further study the previously proposed ansatz, Tr(M ν )=0, for a prediagonal light Majorana type neutrino mass matrix. If CP violation is neglected this enables one to use the existing data on squared mass differences to estimate (up to a discrete ambiguity) the neutrino masses themselves. If it is assumed that only the conventional CP phase is present, the ansatz enables us to estimate this phase in addition to all three masses. If it is assumed that only the two Majorana CP phases are present, the ansatz enables us to present a one parameter family of solutions for the masses and phases. This enables us to obtain a simple 'global' view of lepton number violation effects. Furthermore using an SO(10) motivation for the ansatz suggests an amusing toy (clone) model in which the heavy neutrinos have the same mixing pattern and mass ratios as the light ones. In this case only their overall mass scale is not known (although it is constrained by the initial motivation). Using this toy model we make a rough estimate of the magnitude of the baryon to photon ratio induced by the leptogenesis mechanism. Solutions close to the CP conserving cases seem to be favored

Diagonalization of the mass matrices

International Nuclear Information System (INIS)

Rhee, S.S.

1984-01-01

It is possible to make 20 types of 3x3 mass matrices which are hermitian. We have obtained unitary matrices which could diagonalize each mass matrix. Since the three elements of mass matrix can be expressed in terms of the three eigenvalues, msub(i), we can also express the unitary matrix in terms of msub(i). (Author)

Exact microstate counting for dyonic black holes in AdS4

Science.gov (United States)

Benini, Francesco; Hristov, Kiril; Zaffaroni, Alberto

2017-08-01

We present a counting of microstates of a class of dyonic BPS black holes in AdS4 which precisely reproduces their Bekenstein-Hawking entropy. The counting is performed in the dual boundary description, that provides a non-perturbative definition of quantum gravity, in terms of a twisted and mass-deformed ABJM theory. We evaluate its twisted index and propose an extremization principle to extract the entropy, which reproduces the attractor mechanism in gauged supergravity.

Identification of barley and rye varieties using matrix- assisted laser desorption/ionisation time-of-flight mass spectrometry with neural networks

DEFF Research Database (Denmark)

Bloch, H.A.; Petersen, Marianne Kjerstine; Sperotto, Maria Maddalena

2001-01-01

developed, which combines analysis of alcohol-soluble wheat proteins (gliadins) using matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry with neural networks. Here we have applied the same method for the identification of both barley (Hordeum vulgare L.) and rye (Secale cereale L.......) varieties. For barley, 95% of the mass spectra were correctly classified. This is an encouraging result, since in earlier experiments only a grouping into subsets of varieties was possible. However, the method was not useful in the classification of rye, due to the strong similarity between mass spectra...

MoS{sub 2}/Ag nanohybrid: A novel matrix with synergistic effect for small molecule drugs analysis by negative-ion matrix-assisted laser desorption/ionization time-of-flight mass spectrometry

Energy Technology Data Exchange (ETDEWEB)

Zhao, Yaju, E-mail: daisy19900911@hotmail.com [State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210023 (China); Deng, Guoqing, E-mail: denggqq@sina.com [Department of Polymer Science and Engineering, Nanjing University, Nanjing, 210023 (China); Liu, Xiaohui, E-mail: lcswyh@126.com [State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210023 (China); Sun, Liang, E-mail: sunliang@nju.edu.cn [State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210023 (China); Li, Hui, E-mail: lihui@nju.edu.cn [State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210023 (China); Cheng, Quan, E-mail: quan.cheng@ucr.edu [Department of Chemistry, University of California, Riverside, CA, 92521 (United States); Xi, Kai, E-mail: xikai@nju.edu.cn [Department of Polymer Science and Engineering, Nanjing University, Nanjing, 210023 (China); Xu, Danke, E-mail: xudanke@nju.edu.cn [State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210023 (China)

2016-09-21

This paper reports a facile synthesis of molybdenum disulfide nanosheets/silver nanoparticles (MoS{sub 2}/Ag) hybrid and its use as an effective matrix in negative ion matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). The nanohybrid exerts a strong synergistic effect, leading to high performance detection of small molecule analytes including amino acids, peptides, fatty acids and drugs. The enhancement of laser desorption/ionization (LDI) efficiency is largely attributed to the high surface roughness and large surface area for analyte adsorption, better dispersibility, increased thermal conductivity and enhanced UV energy absorption as compared to pure MoS{sub 2}. Moreover, both Ag nanoparticles and the edge of the MoS{sub 2} layers function as deprotonation sites for proton capture, facilitating the charging process in negative ion mode and promoting formation of negative ions. As a result, the MoS{sub 2}/Ag nanohybrid proves to be a highly attractive matrix in MALDI-TOF MS, with desired features such as high desorption/ionization efficiency, low fragmentation interference, high salt tolerance, and no sweet-spots for mass signal. These characteristic properties allowed for simultaneous analysis of eight different drugs and quantification of acetylsalicylic acid in the spiked human serum. This work demonstrates for the first time the fabrication and application of a novel MoS{sub 2}/Ag hybrid, and provides a new platform for use in the rapid and high throughput analysis of small molecules by mass spectrometry. - Highlights: • MoS{sub 2}/Ag nanohybrid was applied as a novel matrix in negative-ion MALDI-TOF MS. • The MoS{sub 2}/Ag nanohybrid exerted synergistic effect on the detection of small molecules. • The MoS{sub 2}/Ag nanohybrid showed good signal reproducibility and low background interferences comparing to organic matrices. • MoS{sub 2}/Ag allows simultaneous analysis of multiple drugs and quantification of

General property of neutrino mass matrix and CP-violation

International Nuclear Information System (INIS)

Aizawa, Ichiro; Yasue, Masaki

2005-01-01

It is found that the atmospheric neutrino mixing angle of θ atm is determined to be tanθ atm =Im(B)/Im(C) for B=M ν e ν μ and C=M ν e ν τ , where M ij is the ij element of M ν - bar M ν with M ν as a complex symmetric neutrino mass matrix in the (ν e , ν μ , ν τ )-basis. Another mixing angle, θ 13 , defined as U e3 =sinθ 13 e -iδ is subject to the condition: tan2θ 13 ∝|sinθ atm B+cosθ atm C| and the CP-violating Dirac phase of δ is identical to the phase of sinθ atm B*+cosθ atm C*. The smallest value of |sinθ 13 | is achieved at tanθ atm =-Re(C)/Re(B) that yields the maximal CP-violation and that implies C=-κB* for the maximal atmospheric neutrino mixing of tanθ atm =κ=+/-1. The generic smallness of |sinθ 13 | can be ascribed to the tiny violation of the electron number conservation

Solid phase extraction for removal of matrix effects in lipophilic marine toxin analysis by liquid chromatography-tandem mass spectrometry

NARCIS (Netherlands)

Gerssen, A.; McElhinney, M.; Mulder, P.P.J.; Bire, R.; Hess, P.; Boer, de J.

2009-01-01

The potential of solid phase extraction (SPE) clean-up has been assessed to reduce matrix effects (signal suppression or enhancement) in the liquid chromatography-tandem mass spectrometry (LC¿MS/MS) analysis of lipophilic marine toxins. A large array of ion-exchange, silica-based, and mixed-function

Solid phase extraction for removal of matrix effects in lipophilic marine toxin analysis by liquid chromatography-tandem mass spectrometry

NARCIS (Netherlands)

Gerssen, A.; McElhinney, A. M.; Mulder, P.P.J.; Bire, L.; Hess, P.; de Boer, J.

2009-01-01

The potential of solid phase extraction (SPE) clean-up has been assessed to reduce matrix effects (signal suppression or enhancement) in the liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis of lipophilic marine toxins. A large array of ion-exchange, silica-based, and mixed-function

The massive 3-loop operator matrix elements with two masses and the generalized variable flavor number scheme

Energy Technology Data Exchange (ETDEWEB)

Ablinger, J.; Schneider, C. [Johannes Kepler Univ., Linz (Austria). Research Inst. for Symbolic Computation (RISC); Bluemlein, J.; Freitas, A. de; Schoenwald, K. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Goedicke, A. [Karlsruher Institut fuer Technologie (KIT), Karlsruhe (Germany). Inst. fuer Theoretische Teilchenphysik; Wissbrock, F. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Johannes Kepler Univ., Linz (Austria). Research Inst. for Symbolic Computation (RISC)

2017-12-15

We report on our latest results in the calculation of the two-mass contributions to 3-loop operator matrix elements (OMEs). These OMEs are needed to compute the corresponding contributions to the deep-inelastic scattering structure functions and to generalize the variable flavor number scheme by including both charm and bottom quarks. We present the results for the non-singlet and A{sub gq,Q} OMEs, and compare the size of their contribution relative to the single mass case. Results for the gluonic OME A{sub gg,Q} are given in the physical case, going beyond those presented in a previous publication where scalar diagrams were computed. We also discuss our recently published two-mass contribution to the pure singlet OME, and present an alternative method of calculating the corresponding diagrams.

Closed string tachyons on AdS orbifolds and dual Yang-Mills instantons

Energy Technology Data Exchange (ETDEWEB)

Hikida, Y. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Iizuka, N. [California Univ., Santa Barbara, CA (United States). Kavli Inst. for Theoretical Physics

2007-06-15

We study the condensation of localized closed string tachyons on AdS orbifolds both from the bulk and boundary theory viewpoints. We first extend the known results for AdS{sub 5}/Z{sub k} to AdS{sub 3}/Z{sub k} case, and we proposed that the AdS{sub 3}/Z{sub k} decays into AdS{sub 3}/Z{sub k'} with k{sup '} < k. From the bulk viewpoint, we obtain a time-dependent gravity solution describing the decay of AdS orbifold numerically. From the dual gauge theory viewpoint, we calculated the Casimir energies of gauge theory vacua and it is found that their values are exactly the same as the masses of dual geometries, even though they are in different parameter regimes of 't Hooft coupling. We also consider AdS{sub 5} orbifold. The decay of AdS{sub 5}/Z{sub k} is dual to the transition between the vacua of dual gauge theory on R{sub t} x S{sup 3}/Z{sub k}. We constructed the instanton solutions describing the transitions by making use of instanton solutions on R{sub t} x S{sup 2}. (orig.)

A SIMPLE AND RAPID MATRIX-ASSISTED LASER DESORPTION/IONIZATION TIME OF FLIGHT MASS SPECTROMETRY METHOD TO SCREEN FISH PLASMA SAMPLES FOR ESTROGEN-RESPONSIVE BIOMARKERS

Science.gov (United States)

In this study, we describe and evaluate the performance of a simple and rapid mass spectral method for screening fish plasma for estrogen-responsive biomarkers using matrix assisted laster desorption/ionization time of flight mass spectrometry (MALDI-TOF-MS) couopled with a short...

Exact microstate counting for dyonic black holes in AdS4

Directory of Open Access Journals (Sweden)

Francesco Benini

2017-08-01

Full Text Available We present a counting of microstates of a class of dyonic BPS black holes in AdS4 which precisely reproduces their Bekenstein–Hawking entropy. The counting is performed in the dual boundary description, that provides a non-perturbative definition of quantum gravity, in terms of a twisted and mass-deformed ABJM theory. We evaluate its twisted index and propose an extremization principle to extract the entropy, which reproduces the attractor mechanism in gauged supergravity.

Mass matrices of weak interaction, quark flavour mixing and exponential form of Cabibbo-Kobayashi-Maskawa matrix

International Nuclear Information System (INIS)

Dattoli, G.; Torre, A.

1995-01-01

The quark mixing matrix is diagonalized. The use of the exponential parametrization leads to straightforward results, obtained in exact form, without simplifying assumptions. In this study, it is defined weak interaction eigenstates in the sense of Fritzch and Planckl. The relevant mass matrices are derived and are shown to belong to Barnhill canonical forms. It is proven that, at lowest order, these matrices exhibit a democratic structure. The mechanism of democracy breaking is finally discussed

Neutrino Mixing and Masses from a Minimum Principle

CERN Document Server

Alonso, R; Isidori, G; Maiani, L

2013-01-01

We analyze the structure of quark and lepton mass matrices under the hypothesis that they are determined from a minimum principle applied to a generic potential invariant under the $\\left[SU(3)\\right]^5\\otimes \\mathcal O(3)$ flavor symmetry, acting on Standard Model fermions and right-handed neutrinos. Unlike the quark case, we show that hierarchical masses for charged leptons are naturally accompanied by degenerate Majorana neutrinos with one mixing angle close to maximal, a second potentially large, a third one necessarily small, and one maximal relative Majorana phase. Adding small perturbations the predicted structure for the neutrino mass matrix is in excellent agreement with present observations and could be tested in the near future via neutrino-less double beta decay and cosmological measurements. The generalization of these results to arbitrary sew-saw models is also discussed.

Effects of the molar mass of the matrix on electrical properties, structure and morphology of plasticized PANI-PMMA blends

International Nuclear Information System (INIS)

Gmati, Fethi; Fattoum, Arbi; Bohli, Nadra; Mohamed, Abdellatif Belhadj

2008-01-01

The effects of the molar mass of polymethylmethacrylate (PMMA) on electrical, structural and morphological properties of conductive polyaniline-polymethylmethacrylate blends have been studied. We have plasticized the PMMA matrix by using dioctyl phthalate (DioPh). Three different molar masses of PMMA, 15 000, 120 000 and 350 000 g mol -1 , have been used. The x-ray diffraction analysis showed amorphous structure for all our studied PANI-PMMA blend films. The SEM micrographs showed more aggregation with the lowest molar mass of PMMA matrix. The direct current (dc) and alternating current (ac) electrical conductivities have been investigated in the temperature range 20-300 K and frequency range 7-1 x 10 8 Hz. The results of this study indicate an increase of the conductivity when the molar mass of PMMA decreases. With the lowest molar mass of PMMA (15 000 g mol -1 ), we obtained the lowest percolation threshold (p c ∼0.3%). The dc conductivity is governed by Mott's three-dimensional variable range hopping (3D VRH) model; different Mott's parameters have been evaluated. At high frequencies, the ac conductivity follows the power law σ(ω,T) = A(T)ω s(T,ω) , which is characteristic for charge transport in disordered materials by hopping or tunnelling processes. The observed decrease in the frequency exponent s with increasing temperature suggests that the correlated barrier hopping (CBH) model best describes the ac conduction mechanism. All our blends are well described by the scaling law σ(ω)/σ dc = 1+(ω/ω c ) n with n∼0.51-0.52

MALDI (matrix assisted laser desorption ionization) Imaging Mass Spectrometry (IMS) of skin: Aspects of sample preparation.

Science.gov (United States)

de Macedo, Cristiana Santos; Anderson, David M; Schey, Kevin L

2017-11-01

MALDI (matrix assisted laser desorption ionization) Imaging Mass Spectrometry (IMS) allows molecular analysis of biological materials making possible the identification and localization of molecules in tissues, and has been applied to address many questions on skin pathophysiology, as well as on studies about drug absorption and metabolism. Sample preparation for MALDI IMS is the most important part of the workflow, comprising specimen collection and preservation, tissue embedding, cryosectioning, washing, and matrix application. These steps must be carefully optimized for specific analytes of interest (lipids, proteins, drugs, etc.), representing a challenge for skin analysis. In this review, critical parameters for MALDI IMS sample preparation of skin samples will be described. In addition, specific applications of MALDI IMS of skin samples will be presented including wound healing, neoplasia, and infection. Copyright © 2017 Elsevier B.V. All rights reserved.

Added value of shear-wave elastography for evaluation of breast masses detected with screening US imaging.

Science.gov (United States)

Lee, Su Hyun; Chang, Jung Min; Kim, Won Hwa; Bae, Min Sun; Seo, Mirinae; Koo, Hye Ryoung; Chu, A Jung; Gweon, Hye Mi; Cho, Nariya; Moon, Woo Kyung

2014-10-01

To evaluate the additional value of shear-wave elastography (SWE) to B-mode ultrasonography (US) and to determine an appropriate guideline for the combined assessment of screening US-detected breast masses. This study was conducted with institutional review board approval, and written informed consent was obtained. From March 2010 to February 2012, B-mode US and SWE were performed in 159 US-detected breast masses before biopsy. For each lesion, Breast Imaging Reporting and Data System (BI-RADS) category on B-mode US images and the maximum stiffness color and elasticity values on SWE images were assessed. A guideline for adding SWE data to B-mode US was developed with the retrospective cohort to improve diagnostic performance in sensitivity and specificity and was validated in a distinct prospective cohort of 207 women prior to biopsy. Twenty-one of 159 masses in the development cohort and 12 of 207 breast masses in the validation cohort were malignant. In the development cohort, when BI-RADS category 4a masses showing a dark blue color or a maximum elasticity value of 30 kPa or less on SWE images were downgraded to category 3, specificity increased from 9.4% (13 of 138) to 59.4% (82 of 138) and 57.2% (79 of 138) (P breast masses. BI-RADS category 4a masses detected at US screening that showed a dark blue color or a maximum elasticity value of 30 kPa or less on SWE images can be safely followed up instead of performing biopsy. © RSNA, 2014.

Characterization of a novel miniaturized burst-mode infrared laser system for IR-MALDESI mass spectrometry imaging.

Science.gov (United States)

Ekelöf, Måns; Manni, Jeffrey; Nazari, Milad; Bokhart, Mark; Muddiman, David C

2018-03-01

Laser systems are widely used in mass spectrometry as sample probes and ionization sources. Mid-infrared lasers are particularly suitable for analysis of high water content samples such as animal and plant tissues, using water as a resonantly excited sacrificial matrix. Commercially available mid-IR lasers have historically been bulky and expensive due to cooling requirements. This work presents a novel air-cooled miniature mid-IR laser with adjustable burst-mode output and details an evaluation of its performance for mass spectrometry imaging. The miniature laser was found capable of generating sufficient energy for complete ablation of animal tissue in the context of an IR-MALDESI experiment with exogenously added ice matrix, yielding several hundred confident metabolite identifications. Graphical abstract The use of a novel miniature 2.94 μm burst-mode laser in IR-MALDESI allows for rapid and sensitive mass spectrometry imaging of a whole mouse.

Interpretation of organic components from Positive Matrix Factorization of aerosol mass spectrometric data

Directory of Open Access Journals (Sweden)

I. M. Ulbrich

2009-05-01

Full Text Available The organic aerosol (OA dataset from an Aerodyne Aerosol Mass Spectrometer (Q-AMS collected at the Pittsburgh Air Quality Study (PAQS in September 2002 was analyzed with Positive Matrix Factorization (PMF. Three components – hydrocarbon-like organic aerosol OA (HOA, a highly-oxygenated OA (OOA-1 that correlates well with sulfate, and a less-oxygenated, semi-volatile OA (OOA-2 that correlates well with nitrate and chloride – are identified and interpreted as primary combustion emissions, aged SOA, and semivolatile, less aged SOA, respectively. The complexity of interpreting the PMF solutions of unit mass resolution (UMR AMS data is illustrated by a detailed analysis of the solutions as a function of number of components and rotational forcing. A public web-based database of AMS spectra has been created to aid this type of analysis. Realistic synthetic data is also used to characterize the behavior of PMF for choosing the best number of factors, and evaluating the rotations of non-unique solutions. The ambient and synthetic data indicate that the variation of the PMF quality of fit parameter (Q, a normalized chi-squared metric vs. number of factors in the solution is useful to identify the minimum number of factors, but more detailed analysis and interpretation are needed to choose the best number of factors. The maximum value of the rotational matrix is not useful for determining the best number of factors. In synthetic datasets, factors are "split" into two or more components when solving for more factors than were used in the input. Elements of the "splitting" behavior are observed in solutions of real datasets with several factors. Significant structure remains in the residual of the real dataset after physically-meaningful factors have been assigned and an unrealistic number of factors would be required to explain the remaining variance. This residual structure appears to be due to variability in the spectra of the components

Identification of Wheat Varieties Using Matrix-assisted Laser Desorption/Ionisation Time-of-flight Mass Spectrometry and an Artificial Neural network

DEFF Research Database (Denmark)

Bloch, Helle Aagaard; Kesmir, Can; Petersen, Marianne Kjerstine

1999-01-01

A novel tool for variety identification of wheat (Triticum aestivum L,) has been developed: an artificial neural network (ANN) is used to classify the gliadin fraction analysed by matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOFMS). The robustness...

DIFFERENTIATION OF AEROMONAS ISOLATES OBTAINED FROM DRINKING WATER DISTRIBUTION SYSTEM USING MATRIX-ASSISTED LASER DESCRIPTION/IONIZATION-MASS SPECTROMETRY (MALDI-MS)

Science.gov (United States)

The genus Aeromonas is one of several medically significant genera that have gained prominence due to their evolving taxonomy and controversial role in human diseases. In this study, matrix-assisted laser desorption/ionization-mass spectrometry (MALDI-MS) was used to analyze the...

Matrix-assisted laser desorption/ionization-time of flight mass spectrometry: protocol standardization and database expansion for rapid identification of clinically important molds.

Science.gov (United States)

Paul, Saikat; Singh, Pankaj; Rudramurthy, Shivaprakash M; Chakrabarti, Arunaloke; Ghosh, Anup K

2017-12-01

To standardize the matrix-assisted laser desorption ionization-time of flight mass spectrometry protocols and expansion of existing Bruker Biotyper database for mold identification. Four different sample preparation methods (protocol A, B, C and D) were evaluated. On analyzing each protein extraction method, reliable identification and best log scores were achieved through protocol D. The same protocol was used to identify 153 clinical isolates. Of these 153, 123 (80.3%) were accurately identified by using existing database and remaining 30 (19.7%) were not identified due to unavailability in database. On inclusion of missing main spectrum profile in existing database, all 153 isolates were identified. Matrix-assisted laser desorption ionization-time of flight mass spectrometry can be used for routine identification of clinically important molds.

Schwinger-Keldysh propagators from AdS/CFT correspondence

International Nuclear Information System (INIS)

Herzog, C.P.; Son, D.T.

2003-01-01

We demonstrate how to compute real-time Green's functions for a class of finite temperature field theories from their AdS gravity duals. In particular, we reproduce the two-by-two Schwinger-Keldysh matrix propagator from a gravity calculation. Our methods should work also for computing higher point lorentzian signature correlators. We elucidate the boundary condition subtleties which hampered previous efforts to build a lorentzian-signature AdS/CFT correspondence. For two-point correlators, our construction is automatically equivalent to the previously formulated prescription for the retarded propagator. (author)

Throat quantization of the Schwarzschild–Tangherlini(-AdS) black hole

International Nuclear Information System (INIS)

Kunstatter, Gabor; Maeda, Hideki

2014-01-01

Adopting the throat quantization pioneered by Louko and Mäkelä, we derive the mass and area spectra for the Schwarzschild–Tangherlini black hole and its anti-de Sitter (AdS) generalization in arbitrary dimensions. We find that the system can be quantized exactly in three special cases: the three-dimensional BTZ black hole, toroidal black holes in any dimension, and five-dimensional Schwarzshild–Tangherlini(-AdS) black holes. For the remaining cases the spectra are obtained for large mass using the WKB approximation. For asymptotically flat black holes, the area/entropy has an equally spaced spectrum, as expected from previous work. In the asymptotically AdS case on the other hand, it is the mass spectrum that is equally spaced. Our exact results for the BTZ black hole mass with Dirichlet boundary conditions are consistent with the spectra of the corresponding operators in the dual CFT. (paper)

Mass matrix ansatz and lepton flavor violation in the two-Higgs doublet model-III

International Nuclear Information System (INIS)

Diaz-Cruz, J.L.; Noriega-Papaqui, R.; Rosado, A.

2004-01-01

Predictive Higgs-boson-fermion couplings can be obtained when a specific texture for the fermion mass matrices is included in the general two-Higgs doublet model. We derive the form of these couplings in the charged lepton sector using a Hermitian mass matrix ansatz with four-texture zeros. The presence of unconstrained phases in the vertices φ i l i l j modifies the pattern of flavor-violating Higgs boson interactions. Bounds on the model parameters are obtained from present limits on rare lepton flavor-violating processes, which could be extended further by the search for the decay τ→μμμ and μ-e conversion at future experiments. The signal from Higgs boson decays φ i →τμ could be searched for at the CERN Large Hadron Collider, while e-μ transitions could produce a detectable signal at a future eμ collider, through the reaction e + μ - →h 0 →τ + τ -

Multiresidue analysis of multiclass pesticides and polyaromatic hydrocarbons in fatty fish by gas chromatography tandem mass spectrometry and evaluation of matrix effect.

Science.gov (United States)

Chatterjee, Niladri S; Utture, Sagar; Banerjee, Kaushik; Ahammed Shabeer, T P; Kamble, Narayan; Mathew, Suseela; Ashok Kumar, K

2016-04-01

This paper reports a selective and sensitive method for multiresidue determination of 119 chemical residues including pesticides and polyaromatic hydrocarbons (PAH) in high fatty fish matrix. The novel sample preparation method involved extraction of the target analytes from homogenized fish meat (5 g) in acetonitrile (15 mL, 1% acetic acid) after three-phase partitioning with hexane (2 mL) and the remaining aqueous layer. An aliquot (1.5 mL) of the acetonitrile layer was aspirated and subjected to two-stage dispersive solid phase extraction (dSPE) cleanup and the residues were finally estimated by gas chromatography mass spectrometry with selected reaction monitoring (GC-MS/MS). The co-eluted matrix components were identified on the basis of their accurate mass by GC with quadrupole time of flight MS. Addition of hexane during extraction and optimized dSPE cleanup significantly minimized the matrix effects. Recoveries at 10, 25 and 50 μg/kg were within 60-120% with associated precision, RSD<11%. Copyright © 2015 Elsevier Ltd. All rights reserved.

Parallel O(log n) algorithms for open- and closed-chain rigid multibody systems based on a new mass matrix factorization technique

Science.gov (United States)

Fijany, Amir

1993-01-01

In this paper, parallel O(log n) algorithms for computation of rigid multibody dynamics are developed. These parallel algorithms are derived by parallelization of new O(n) algorithms for the problem. The underlying feature of these O(n) algorithms is a drastically different strategy for decomposition of interbody force which leads to a new factorization of the mass matrix (M). Specifically, it is shown that a factorization of the inverse of the mass matrix in the form of the Schur Complement is derived as M(exp -1) = C - B(exp *)A(exp -1)B, wherein matrices C, A, and B are block tridiagonal matrices. The new O(n) algorithm is then derived as a recursive implementation of this factorization of M(exp -1). For the closed-chain systems, similar factorizations and O(n) algorithms for computation of Operational Space Mass Matrix lambda and its inverse lambda(exp -1) are also derived. It is shown that these O(n) algorithms are strictly parallel, that is, they are less efficient than other algorithms for serial computation of the problem. But, to our knowledge, they are the only known algorithms that can be parallelized and that lead to both time- and processor-optimal parallel algorithms for the problem, i.e., parallel O(log n) algorithms with O(n) processors. The developed parallel algorithms, in addition to their theoretical significance, are also practical from an implementation point of view due to their simple architectural requirements.

Reactive solute transport in an asymmetrical fracture-rock matrix system

Science.gov (United States)

Zhou, Renjie; Zhan, Hongbin

2018-02-01

The understanding of reactive solute transport in a single fracture-rock matrix system is the foundation of studying transport behavior in the complex fractured porous media. When transport properties are asymmetrically distributed in the adjacent rock matrixes, reactive solute transport has to be considered as a coupled three-domain problem, which is more complex than the symmetric case with identical transport properties in the adjacent rock matrixes. This study deals with the transport problem in a single fracture-rock matrix system with asymmetrical distribution of transport properties in the rock matrixes. Mathematical models are developed for such a problem under the first-type and the third-type boundary conditions to analyze the spatio-temporal concentration and mass distribution in the fracture and rock matrix with the help of Laplace transform technique and de Hoog numerical inverse Laplace algorithm. The newly acquired solutions are then tested extensively against previous analytical and numerical solutions and are proven to be robust and accurate. Furthermore, a water flushing phase is imposed on the left boundary of system after a certain time. The diffusive mass exchange along the fracture/rock matrixes interfaces and the relative masses stored in each of three domains (fracture, upper rock matrix, and lower rock matrix) after the water flushing provide great insights of transport with asymmetric distribution of transport properties. This study has the following findings: 1) Asymmetric distribution of transport properties imposes greater controls on solute transport in the rock matrixes. However, transport in the fracture is mildly influenced. 2) The mass stored in the fracture responses quickly to water flushing, while the mass stored in the rock matrix is much less sensitive to the water flushing. 3) The diffusive mass exchange during the water flushing phase has similar patterns under symmetric and asymmetric cases. 4) The characteristic distance

Impact of model resolution on simulated wind, drifting snow and surface mass balance in Terre Adélie, East Antarctica

NARCIS (Netherlands)

Lenaerts, J.T.M.|info:eu-repo/dai/nl/314850163; van den Broeke, M.R.|info:eu-repo/dai/nl/073765643; Scarchilli, C.; Agosta, C.

2012-01-01

This paper presents the impact of model resolution on the simulated wind speed, drifting snow climate and surface mass balance (SMB) of Terre Ad´elie and its surroundings, East Antarctica. We compare regional climate model simulations at 27 and 5.5 km resolution for the year 2009. The wind speed

A Measurement of the Top Quark Mass in 1.96 TeV Proton-Antiproton Collisions Using a Novel Matrix Element Method

International Nuclear Information System (INIS)

CDF Collaboration; Freeman, John; Freeman, John

2007-01-01

A measurement of the top quark mass in t(bar t) → l + jets candidate events, obtained from p(bar p) collisions at √s = 1.96 TeV at the Fermilab Tevatron using the CDF II detector, is presented. The measurement approach is that of a matrix element method. For each candidate event, a two dimensional likelihood is calculated in the top pole mass and a constant scale factor, 'JES', where JES multiplies the input particle jet momenta and is designed to account for the systematic uncertainty of the jet momentum reconstruction. As with all matrix element techniques, the method involves an integration using the Standard Model matrix element for t(bar t) production and decay. However, the technique presented is unique in that the matrix element is modified to compensate for kinematic assumptions which are made to reduce computation time. Background events are dealt with through use of an event observable which distinguishes signal from background, as well as through a cut on the value of an event's maximum likelihood. Results are based on a 955 pb -1 data sample, using events with a high-p T lepton and exactly four high-energy jets, at least one of which is tagged as coming from a b quark; 149 events pass all the selection requirements. They find M meas = 169.8 ± 2.3(stat.) ± 1.4(syst.) GeV/c 2

A Measurement of the Top Quark Mass in 1.96 TeV Proton-Antiproton Collisions Using a Novel Matrix Element Method

Energy Technology Data Exchange (ETDEWEB)

Freeman, John [Univ. of California, Berkeley, CA (United States)

2007-01-01

A measurement of the top quark mass in t$\\bar{t}$ → l + jets candidate events, obtained from p$\\bar{p}$ collisions at √s = 1.96 TeV at the Fermilab Tevatron using the CDF II detector, is presented. The measurement approach is that of a matrix element method. For each candidate event, a two dimensional likelihood is calculated in the top pole mass and a constant scale factor, 'JES', where JES multiplies the input particle jet momenta and is designed to account for the systematic uncertainty of the jet momentum reconstruction. As with all matrix element techniques, the method involves an integration using the Standard Model matrix element for t$\\bar{t}$ production and decay. However, the technique presented is unique in that the matrix element is modified to compensate for kinematic assumptions which are made to reduce computation time. Background events are dealt with through use of an event observable which distinguishes signal from background, as well as through a cut on the value of an event's maximum likelihood. Results are based on a 955 pb^-1 data sample, using events with a high-p_T lepton and exactly four high-energy jets, at least one of which is tagged as coming from a b quark; 149 events pass all the selection requirements. They find M_meas = 169.8 ± 2.3(stat.) ± 1.4(syst.) GeV/c².

Bulk metallic glass matrix composites

International Nuclear Information System (INIS)

Choi-Yim, H.; Johnson, W.L.

1997-01-01

Composites with a bulk metallic glass matrix were synthesized and characterized. This was made possible by the recent development of bulk metallic glasses that exhibit high resistance to crystallization in the undercooled liquid state. In this letter, experimental methods for processing metallic glass composites are introduced. Three different bulk metallic glass forming alloys were used as the matrix materials. Both ceramics and metals were introduced as reinforcement into the metallic glass. The metallic glass matrix remained amorphous after adding up to a 30 vol% fraction of particles or short wires. X-ray diffraction patterns of the composites show only peaks from the second phase particles superimposed on the broad diffuse maxima from the amorphous phase. Optical micrographs reveal uniformly distributed particles in the matrix. The glass transition of the amorphous matrix and the crystallization behavior of the composites were studied by calorimetric methods. copyright 1997 American Institute of Physics

Dimensional degression in AdSd

International Nuclear Information System (INIS)

Artsukevich, A. Yu.; Vasiliev, M. A.

2009-01-01

We analyze the pattern of fields in (d+1)-dimensional anti-de Sitter space in terms of those in d-dimensional anti-de Sitter space. The procedure, which is neither dimensional reduction nor dimensional compactification, is called dimensional degression. The analysis is performed group theoretically for all totally symmetric bosonic and fermionic representations of the anti-de Sitter algebra. The field-theoretical analysis is done for a massive scalar field in AdS d+d ' and massless spin-one-half, spin-one, and spin-two fields in AdS d+1 . The mass spectra of the resulting towers of fields in AdS d are found. For the scalar field case, the obtained results extend to the shadow sector those obtained by Metsaev [Nucl. Phys. B, Proc. Suppl. 102, 100 (2001)] by a different method.

Independent assessment of matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) sample preparation quality: Effect of sample preparation on MALDI-MS of synthetic polymers.

Science.gov (United States)

Kooijman, Pieter C; Kok, Sander; Honing, Maarten

2017-02-28

Matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) provides detailed and in-depth information about the molecular characteristics of synthetic polymers. To obtain the most accurate results the sample preparation parameters should be chosen to suit the sample and the aim of the experiment. Because the underlying principles of MALDI are still not fully known, a priori determination of optimal sample preparation protocols is often not possible. Employing an automated sample preparation quality assessment method recently presented by us we quantified the sample preparation quality obtained using various sample preparation protocols. Six conventional matrices with and without added potassium as a cationization agent and six ionic liquid matrices (ILMs) were assessed using poly(ethylene glycol) (PEG), polytetrahydrofuran (PTHF) and poly(methyl methacrylate) (PMMA) as samples. All sample preparation protocols were scored and ranked based on predefined quality parameters and spot-to-spot repeatability. Clearly distinctive preferences were observed in matrix identity and cationization agent for PEG, PTHF and PMMA, as the addition of an excess of potassium cationization agent results in an increased score for PMMA and a contrasting matrix-dependent effect for PTHF and PEG. The addition of excess cationization agent to sample mixtures dissipates any overrepresentation of high molecular weight polymer species. Our results show reduced ionization efficiency and similar sample deposit homogeneity for all tested ILMs, compared with well-performing conventional MALDI matrices. The results published here represent a start in the unsupervised quantification of sample preparation quality for MALDI samples. This method can select the best sample preparation parameters for any synthetic polymer sample and the results can be used to formulate hypotheses on MALDI principles. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Analytical Model of Water Flow in Coal with Active Matrix

Science.gov (United States)

Siemek, Jakub; Stopa, Jerzy

2014-12-01

This paper presents new analytical model of gas-water flow in coal seams in one dimension with emphasis on interactions between water flowing in cleats and coal matrix. Coal as a flowing system, can be viewed as a solid organic material consisting of two flow subsystems: a microporous matrix and a system of interconnected macropores and fractures. Most of gas is accumulated in the microporous matrix, where the primary flow mechanism is diffusion. Fractures and cleats existing in coal play an important role as a transportation system for macro scale flow of water and gas governed by Darcy's law. The coal matrix can imbibe water under capillary forces leading to exchange of mass between fractures and coal matrix. In this paper new partial differential equation for water saturation in fractures has been formulated, respecting mass exchange between coal matrix and fractures. Exact analytical solution has been obtained using the method of characteristics. The final solution has very simple form that may be useful for practical engineering calculations. It was observed that the rate of exchange of mass between the fractures and the coal matrix is governed by an expression which is analogous to the Newton cooling law known from theory of heat exchange, but in present case the mass transfer coefficient depends not only on coal and fluid properties but also on time and position. The constant term of mass transfer coefficient depends on relation between micro porosity and macro porosity of coal, capillary forces, and microporous structure of coal matrix. This term can be expressed theoretically or obtained experimentally. W artykule zaprezentowano nowy model matematyczny przepływu wody i gazu w jednowymiarowej warstwie węglowej z uwzględnieniem wymiany masy między systemem szczelin i matrycą węglową. Węgiel jako system przepływowy traktowany jest jako układ o podwójnej porowatości i przepuszczalności, składający się z mikroporowatej matrycy węglowej oraz z

The investigation of added masses and damping factors for vibrations of tube and tube bundles in fluid

International Nuclear Information System (INIS)

Sinyavskii, V.F.; Fedotovskii, V.S.; Kukhtin, A.B.

1977-01-01

The vibrations of single cylinders in fluid being surrounded by the solid walls of different form as well as the bundles of cylindric rods have been considered in this report. A model is proposed for hydrodynamic damping of vibrations and the analytic solution of a problem concerning damping of cylinder vibrations in fluid surrounded by a concentric shell. It has been shown that the fluid viscosity and vibration frequency influence the value of the fluid added mass and the damping factor of vibrations

Crystal manyfold universes in /AdS space

Science.gov (United States)

Kaloper, N.

2000-02-01

We derive crystal braneworld solutions, comprising of intersecting families of parallel /n+2-branes in a /4+n-dimensional /AdS space. Each family consists of alternating positive and negative tension branes. In the simplest case of exactly orthogonal families, there arise different crystals with unbroken /4D Poincaré invariance on the intersections, where our world can reside. A crystal can be finite along some direction, either because that direction is compact, or because it ends on a segment of /AdS bulk, or infinite, where the branes continue forever. If the crystal is interlaced by connected /3-branes directed both along the intersections and orthogonal to them, it can be viewed as an example of a Manyfold universe proposed recently by Arkani-Hamed, Dimopoulos, Dvali and the author. There are new ways for generating hierarchies, since the bulk volume of the crystal and the lattice spacing affect the /4D Planck mass. The low energy physics is sensitive to the boundary conditions in the bulk, and has to satisfy the same constraints discussed in the Manyfold universe. Phenomenological considerations favor either finite crystals, or crystals which are infinite but have broken translational invariance in the bulk. The most distinctive signature of the bulk structure is that the bulk gravitons are Bloch waves, with a band spectrum, which we explicitly construct in the case of a /5-dimensional theory.

Influence of the added mass effect and boundary conditions on the dynamic response of submerged and confined structures

International Nuclear Information System (INIS)

Valentín, D; Presas, A; Egusquiza, E; Valero, C

2014-01-01

The dynamic response of submerged and confined disk-like structures is of interest in the flied of hydraulic machinery, especially in hydraulic turbine runners. This response is difficult to be estimated with accuracy due to the strong influence of the boundary conditions. Small radial gaps as well as short axial distances to rigid surfaces greatly modify the dynamic response because the fact of the added mass and damping effects. Moreover, the effect of the shaft coupling is also important for certain mode-shapes of the structure. In the present study, the influence of the added mass effect and boundary conditions on the dynamic behavior of a submerged disk attached to a shaft is evaluated through experimental tests and structural- acoustic coupling numerical simulations. For the experimentation, a test rig has been developed. It consists of a confined disk attached to a shaft inside a cylindrical container full of water. The disk can be fixed at different axial positions along the shaft. Piezoelectric patches are used to excite the disk and the response is measured with submersible accelerometers. For each configuration tested, the natural frequencies of the disk and the shaft are studied. Numerical results have been compared with experimental results

Study of the mechanisms of matrix assisted laser desorption / ionization

International Nuclear Information System (INIS)

Manuelli, Pascal

1995-01-01

This research thesis aims at a better knowledge of some aspects of a complex mechanism: the matrix-assisted laser desorption/ionization (MALDI). The author first proposes a comparative analysis of results obtained by time-of-flight (TOF) mass spectrometry and by Fourier transform mass spectrometry. He reports the study of the matrix role (notably a polymeric matrix) as a matter submitted to laser desorption. In this respect, the influence of the incident wavelength has been studied. The author also reports a comparative of ions produced by matrix laser desorption (study performed by Fourier transform mass spectrometry) and of neutral molecules (study performed by flash pyrolysis coupled with gas chromatography and with mass spectrometry). Finally, results obtained on derivatives and complexes based on beta-cyclodextrins highlight benefits as well as limitations of this technique [fr

Negative mass solitons in gravity

International Nuclear Information System (INIS)

Cebeci, Hakan; Sarioglu, Oezguer; Tekin, Bayram

2006-01-01

We first reconstruct the conserved (Abbott-Deser) charges in the spin-connection formalism of gravity for asymptotically (Anti)-de Sitter spaces, and then compute the masses of the AdS soliton and the recently found Eguchi-Hanson solitons in generic odd dimensions, unlike the previous result obtained for only five dimensions. These solutions have negative masses compared to the global AdS or AdS/Z p spacetimes. As a separate note, we also compute the masses of the recent even dimensional Taub-NUT-Reissner-Nordstroem metrics

Hawking Radiation-Quasinormal Modes Correspondence for Large AdS Black Holes

Directory of Open Access Journals (Sweden)

Dao-Quan Sun

2017-01-01

Full Text Available It is well-known that the nonstrictly thermal character of the Hawking radiation spectrum generates a natural correspondence between Hawking radiation and black hole quasinormal modes. This main issue has been analyzed in the framework of Schwarzschild black holes, Kerr black holes, and nonextremal Reissner-Nordstrom black holes. In this paper, by introducing the effective temperature, we reanalyze the nonstrictly thermal character of large AdS black holes. The results show that the effective mass corresponding to the effective temperature is approximatively the average one in any dimension. And the other effective quantities can also be obtained. Based on the known forms of frequency in quasinormal modes, we reanalyze the asymptotic frequencies of the large AdS black hole in three and five dimensions. Then we get the formulas of the Bekenstein-Hawking entropy and the horizon’s area quantization with functions of the quantum “overtone” number n.

Detection and quantification of neurotensin in human brain tissue by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry

DEFF Research Database (Denmark)

Gobom, J; Kraeuter, K O; Persson, R

2000-01-01

A method was developed for mass spectrometric detection of neurotensin (NT)-like immunoreactivity and quantification of NT in human brain tissue. The method is based on immunoprecipitation followed by analysis using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF......-MS). The identity of the major component of the immunoprecipitates as neurotensin was confirmed by fragment ion analysis on an electrospray ionization quadrupole time-of-flight instrument. MALDI-TOF-MS quantification of NT was achieved using stable-isotope-labeled NT as the internal standard, yielding an error...

A novel type of matrix for surface-assisted laser desorption-ionization mass spectrometric detection of biomolecules using metal-organic frameworks.

Science.gov (United States)

Fu, Chien-Ping; Lirio, Stephen; Liu, Wan-Ling; Lin, Chia-Her; Huang, Hsi-Ya

2015-08-12

A 3D metal-organic framework (MOF) nanomaterial as matrix for surface-assisted laser desorption/ionization mass spectrometry (SALDI-MS) and tandem mass spectrometry (MS/MS) was developed for the analysis of complex biomolecules. Unlike other nanoparticle matrices, this MOF nanomaterial does not need chemical modification prior to use. An exceptional signal reproducibility as well as very low background interferences in analyzing mono-/di-saccharides, peptides and complex starch digests demonstrate its high potential for biomolecule assays, especially for small molecules. Copyright © 2015 Elsevier B.V. All rights reserved.

Covariant anomalies and Hawking radiation from Kaluza–Klein AdS ...

Indian Academy of Sciences (India)

the 4D KK-AdS black hole solution was generalized to the one in arbitrary dimensions. [28]. After obtaining a black hole solution, it is very important to compute its thermodynam- ical quantities, such as the mass, the charge, the angular momentum, the entropy and the temperature. All these quantities are presented in ref.

Simultaneous determination of phenolic compounds in Equisetum palustre L. by ultra high performance liquid chromatography with tandem mass spectrometry combined with matrix solid-phase dispersion extraction.

Science.gov (United States)

Wei, Zuofu; Pan, Youzhi; Li, Lu; Huang, Yuyang; Qi, Xiaolin; Luo, Meng; Zu, Yuangang; Fu, Yujie

2014-11-01

A method based on matrix solid-phase dispersion extraction followed by ultra high performance liquid chromatography with tandem mass spectrometry is presented for the extraction and determination of phenolic compounds in Equisetum palustre. This method combines the high efficiency of matrix solid-phase dispersion extraction and the rapidity, sensitivity, and accuracy of ultra high performance liquid chromatography with tandem mass spectrometry. The influential parameters of the matrix solid-phase dispersion extraction were investigated and optimized. The optimized conditions were as follows: silica gel was selected as dispersing sorbent, the ratio of silica gel to sample was selected to be 2:1 (400/200 mg), and 8 mL of 80% methanol was used as elution solvent. Furthermore, a fast and sensitive ultra high performance liquid chromatography with tandem mass spectrometry method was developed for the determination of nine phenolic compounds in E. palustre. This method was carried out within <6 min, and exhibited satisfactory linearity, precision, and recovery. Compared with ultrasound-assisted extraction, the proposed matrix solid-phase dispersion procedure possessed higher extraction efficiency, and was more convenient and time saving with reduced requirements on sample and solvent amounts. All these results suggest that the developed method represents an excellent alternative for the extraction and determination of active components in plant matrices. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Analysis of Microbial Mixtures by Matrix-assisted Laser Desorption/Ionization time-of-flight Mass Spectrometry

Energy Technology Data Exchange (ETDEWEB)

Wahl, Karen L.; Wunschel, Sharon C.; Jarman, Kristin H.; Valentine, Nancy B.; Petersen, Catherine E.; Kingsley, Mark T.; Zartolas, Kimberly A.; Saenz, Adam J.

2002-12-15

Many different laboratories are currently developing mass-spectrometric techniques to analyze and identify microorganisms. However, minimal work has been done with mixtures of bacteria. To demonstrate that microbial mixtures could be analyzed by matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS), mixed bacterial cultures were analyzed in a double-blind fashion. Nine different bacterial species currently in our MALDI-MS fingerprint library were used to generate 50 different simulated mixed bacterial cultures similar to that done for an initial blind study previously reported.(1) The samples were analyzed by MALDI-MS with automated data extraction and analysis algorithms developed in our laboratory. The components present in the sample were identified correctly to the species level in all but one of the samples. However, correctly eliminating closely related organisms was challenging for the current algorithms, especially in differentiating Serratia marcescens, Escherichia coli, and Yersinia enterocolitica, which have some similarities in their MALDI-MS fingerprints. Efforts to improve the specificity of the algorithms are in progress.

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry: a new possibility for the identification and typing of anaerobic bacteria.

Science.gov (United States)

Nagy, Elizabeth

2014-01-01

Anaerobic bacteria predominate in the normal flora of humans and are important, often life-threatening pathogens in mixed infections originating from the indigenous microbiota. The isolation and identification of anaerobes by phenotypic and DNA-based molecular methods at a species level is time-consuming and laborious. Following the successful adaptation of the matrix-assisted laser desorption/ionization time-of-flight mass spectrometry for the routine laboratory identification of bacteria, the extensive development of a database has been initiated to use this method for the identification of anaerobic bacteria. Not only frequently isolated anaerobic species, but also newly recognized and taxonomically rearranged genera and species can be identified using direct smear samples or whole-cell protein extraction, and even phylogenetically closely related species can be identified correctly by means of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Typing of anaerobic bacteria on a subspecies level, determination of antibiotic resistance and direct identification of blood culture isolates will revolutionize anaerobe bacteriology in the near future.

Solid-supported enzymatic synthesis of pectic oligogalacturonides and their analysis by MALDI-TOF mass spectrometry

DEFF Research Database (Denmark)

Guillaumie, Fanny; Sterling, J.D.; Jensen, K.J.

2003-01-01

Solid-phase biosynthetic reactions, followed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry analysis (MALDI-TOF), was used to gain insight into the biosynthesis of pectin oligomers. Sepharose supports bearing long pectic oligogalacturonides (OGAs) anchored through...... into the liquid phases by MALDI-TOF mass spectrometry. In time course studies conducted with an immobilized (alpha-D-GalA)(14) and limiting amounts of the glycosyl donor, the predominant product was an OGA extended by one GalA residue at the non-reducing end (i.e., (GalA)(15)). When UDP-GalA was added...

Partition functions with spin in AdS2 via quasinormal mode methods

International Nuclear Information System (INIS)

Keeler, Cynthia; Lisbão, Pedro; Ng, Gim Seng

2016-01-01

We extend the results of http://dx.doi.org/10.1007/JHEP06(2014)099, computing one loop partition functions for massive fields with spin half in AdS 2 using the quasinormal mode method proposed by Denef, Hartnoll, and Sachdev http://dx.doi.org/10.1088/0264-9381/27/12/125001. We find the finite representations of SO(2,1) for spin zero and spin half, consisting of a highest weight state |h〉 and descendants with non-unitary values of h. These finite representations capture the poles and zeroes of the one loop determinants. Together with the asymptotic behavior of the partition functions (which can be easily computed using a large mass heat kernel expansion), these are sufficient to determine the full answer for the one loop determinants. We also discuss extensions to higher dimensional AdS 2n and higher spins.

Natural products in Glycyrrhiza glabra (licorice) rhizome imaged at the cellular level by atmospheric pressure matrix-assisted laser desorption/ionization tandem mass spectrometry imaging

DEFF Research Database (Denmark)

Li, Bin; Bhandari, Dhaka Ram; Janfelt, Christian

2014-01-01

The rhizome of Glycyrrhiza glabra (licorice) was analyzed by high-resolution mass spectrometry imaging and tandem mass spectrometry imaging. An atmospheric pressure matrix-assisted laser desorption/ionization imaging ion source was combined with an orbital trapping mass spectrometer in order to o...... and saponins in legume species, combing the spatially resolved chemical information with morphological details at the microscopic level. Furthermore, the technique offers a scheme capable of high-throughput profiling of metabolites in plant tissues....

Adiabatic pumping solutions in global AdS

Energy Technology Data Exchange (ETDEWEB)

Carracedo, Pablo [Meteo-Galicia,Santiago de Compostela E-15782 (Spain); Mas, Javier; Musso, Daniele; Serantes, Alexandre [Departamento de Física de Partículas, Universidade de Santiago de Compostela,Santiago de Compostela E-15782 (Spain); Instituto Galego de Física de Altas Enerxías (IGFAE),Santiago de Compostela E-15782 (Spain)

2017-05-26

We construct a family of very simple stationary solutions to gravity coupled to a massless scalar field in global AdS. They involve a constantly rising source for the scalar field at the boundary and thereby we name them pumping solutions. We construct them numerically in D=4. They are regular and, generically, have negative mass. We perform a study of linear and nonlinear stability and find both stable and unstable branches. In the latter case, solutions belonging to different sub-branches can either decay to black holes or to limiting cycles. This observation motivates the search for non-stationary exactly time-periodic solutions which we actually construct. We clarify the role of pumping solutions in the context of quasistatic adiabatic quenches. In D=3 the pumping solutions can be related to other previously known solutions, like magnetic or translationally-breaking backgrounds. From this we derive an analytic expression.

Flavor symmetry breaking and meson masses

International Nuclear Information System (INIS)

Bhagwat, Mandar S.; Roberts, Craig D.; Chang Lei; Liu Yuxin; Tandy, Peter C.

2007-01-01

The axial-vector Ward-Takahashi identity is used to derive mass formulas for neutral pseudoscalar mesons. Flavor symmetry breaking entails nonideal flavor content for these states. Adding that the η ' is not a Goldstone mode, exact chiral-limit relations are developed from the identity. They connect the dressed-quark propagator to the topological susceptibility. It is confirmed that in the chiral limit the η ' mass is proportional to the matrix element which connects this state to the vacuum via the topological susceptibility. The implications of the mass formulas are illustrated using an elementary dynamical model, which includes an Ansatz for that part of the Bethe-Salpeter kernel related to the non-Abelian anomaly. In addition to the current-quark masses, the model involves two parameters, one of which is a mass-scale. It is employed in an analysis of pseudoscalar- and vector-meson bound-states. While the effects of SU(N f =2) and SU(N f =3) flavor symmetry breaking are emphasized, the five-flavor spectra are described. Despite its simplicity, the model is elucidative and phenomenologically efficacious; e.g., it predicts η-η ' mixing angles of ∼-15 deg. and π 0 -η angles of ∼1 deg

Measurement of the Top Quark Mass at D0 Run II with the Matrix Element Method in the Lepton+Jets Final State

Energy Technology Data Exchange (ETDEWEB)

Schieferdecker, Philipp [Ludwig Maximilian Univ. of Munich (Germany)

2005-08-05

The mass of the top quark is a fundamental parameter of the Standard Model. Its precise knowledge yields valuable insights into unresolved phenomena in and beyond the Standard Model. A measurement of the top quark mass with the matrix element method in the lepton+jets final state in D0 Run II is presented. Events are selected requiring an isolated energetic charged lepton (electron or muon), significant missing transverse energy, and exactly four calorimeter jets. For each event, the probabilities to originate from the signal and background processes are calculated based on the measured kinematics, the object resolutions and the respective matrix elements. The jet energy scale is known to be the dominant source of systematic uncertainty. The reference scale for the mass measurement is derived from Monte Carlo events. The matrix element likelihood is defined as a function of both, m{sub top} and jet energy scale JES, where the latter represents a scale factor with respect to the reference scale. The top mass is obtained from a two-dimensional correlated fit, and the likelihood yields both the statistical and jet energy scale uncertainty. Using a dataset of 320 pb^-1 of D0 Run II data, the mass of the top quark is measured to be: m$ℓ+jets\\atop{top}$ = 169.5 ± 4.4(stat. + JES)$+1.7\\atop{-1.6}$(syst.) GeV; m$e+jets\\atop{top}$ = 168.8 ± 6.0(stat. + JES)$+1.9\\atop{-1.9}$(syst.) GeV; m$μ+jets\\atop{top}$ = 172.3 ± 9.6(stat.+JES)$+3.4\\atop{-3.3}$(syst.) GeV. The jet energy scale measurement in the ℓ+jets sample yields JES = 1.034 ± 0.034, suggesting good consistency of the data with the simulation. The measurement forecasts significant improvements to the total top mass uncertainty during Run II before the startup of the LHC, as the data sample will grow by a factor of ten and D0's tracking capabilities will be employed in jet energy reconstruction and flavor identification.

Liquid Chromatography–Mass Spectrometry Based Metabolomics Study of Cloned versus Normal Pigs Fed Either Restricted or Ad Libitum High-Energy Diets

DEFF Research Database (Denmark)

Christensen, Kirstine Lykke; Hedemann, Mette Skou; Jørgensen, Henry

2012-01-01

Genetically identical cloned pigs should in principle eliminate biological variation and provide more pronounced effects when subjected to, e.g., dietary interventions, but little is known about how phenotype and phenotypic variation is affected by cloning. Therefore, an investigation...... of the metabolome of cloned pigs compared to normal control pigs was performed to elucidate the variation and possible differences in the metabolic phenotypes during a dietary intervention. A total of 19 control pigs and 17 cloned pigs were given the same high-energy dense diet either ad libitum or in a restricted...... manner (60% of ad libitum) for 6 months, and plasma was subjected to liquid chromatography–mass spectrometry nontargeted metabolomics and biochemical analyses. Low systemic levels of IGF-1 could indicate altered growth conditions and energy metabolism in cloned pigs. In response to ad libitum feeding...

Matrix-assisted laser desorption ionization-time of flight mass spectrometry for direct bacterial identification from positive blood culture pellets.

Science.gov (United States)

Prod'hom, Guy; Bizzini, Alain; Durussel, Christian; Bille, Jacques; Greub, Gilbert

2010-04-01

An ammonium chloride erythrocyte-lysing procedure was used to prepare a bacterial pellet from positive blood cultures for direct matrix-assisted laser desorption-ionization time of flight (MALDI-TOF) mass spectrometry analysis. Identification was obtained for 78.7% of the pellets tested. Moreover, 99% of the MALDI-TOF identifications were congruent at the species level when considering valid scores. This fast and accurate method is promising.

Study of ionization process of matrix molecules in matrix-assisted laser desorption ionization

Energy Technology Data Exchange (ETDEWEB)

Murakami, Kazumasa; Sato, Asami; Hashimoto, Kenro; Fujino, Tatsuya, E-mail: fujino@tmu.ac.jp

2013-06-20

Highlights: ► Proton transfer and adduction reaction of matrix in MALDI were studied. ► Hydroxyl group forming intramolecular hydrogen bond was related to the ionization. ► Intramolecular proton transfer in the electronic excited state was the initial step. ► Non-volatile analytes stabilized protonated matrix in the ground state. ► A possible mechanism, “analyte support mechanism”, has been proposed. - Abstract: Proton transfer and adduction reaction of matrix molecules in matrix-assisted laser desorption ionization were studied. By using 2,4,6-trihydroxyacetophenone (THAP), 2,5-dihydroxybenzoic acid (DHBA), and their related compounds in which the position of a hydroxyl group is different, it was clarified that a hydroxyl group forming an intramolecular hydrogen bond is related to the ionization of matrix molecules. Intramolecular proton transfer in the electronic excited state of the matrix and subsequent proton adduction from a surrounding solvent to the charge-separated matrix are the initial steps for the ionization of matrix molecules. Nanosecond pump–probe NIR–UV mass spectrometry confirmed that the existence of analyte molecules having large dipole moment in their structures is necessary for the stabilization of [matrix + H]{sup +} in the electronic ground state.

Unitary Supermultiplets of $OSp(8^{*}|4)$ and the $AdS_{7}/CFT_{6}$ Duality

CERN Document Server

Günaydin, M; Gunaydin, Murat; Takemae, Seiji

2000-01-01

We study the unitary supermultiplets of the N=4 d=7 anti-de Sitter (AdS_7) superalgebra OSp(8^*|4), with the even subalgebra SO(6,2) X USp(4), which is the symmetry superalgebra of M-theory on AdS_7 X S^4. We give a complete classification of the positive energy doubleton and massless supermultiplets of OSp(8^*|4) . The ultra-short doubleton supermultiplets do not have a Poincaré limit in AdS_7 and correspond to superconformal field theories on the boundary of AdS_7 which can be identified with d=6 Minkowski space. We show that the six dimensional Poincare mass operator vanishes identically for the doubleton representations. By going from the compact U(4) basis of SO^*(8)=SO(6,2) to the noncompact basis SU^*(4)XD (d=6 Lorentz group times dilatations) one can associate the positive (conformal) energy representations of SO^*(8) with conformal fields transforming covariantly under the Lorentz group in d=6. The oscillator method used for the construction of the unitary supermultiplets of OSp(8^*|4) can be given ...

On renormalization group flow in matrix model

International Nuclear Information System (INIS)

Gao, H.B.

1992-10-01

The renormalization group flow recently found by Brezin and Zinn-Justin by integrating out redundant entries of the (N+1)x(N+1) Hermitian random matrix is studied. By introducing explicitly the RG flow parameter, and adding suitable counter terms to the matrix potential of the one matrix model, we deduce some interesting properties of the RG trajectories. In particular, the string equation for the general massive model interpolating between the UV and IR fixed points turns out to be a consequence of RG flow. An ambiguity in the UV region of the RG trajectory is remarked to be related to the large order behaviour of the one matrix model. (author). 7 refs

Vector condensate and AdS soliton instability induced by a magnetic field

International Nuclear Information System (INIS)

Cai, Rong-Gen; Li, Li; Li, Li-Fang; Wu, You

2014-01-01

We continue to study the holographic p-wave superconductor model in the Einstein-Maxwell-complex vector field theory with a non-minimal coupling between the complex vector field and the Maxwell field. In this paper we work in the AdS soliton background which describes a conformal field theory in the confined phase and focus on the probe approximation. We find that an applied magnetic field can lead to the condensate of the vector field and the AdS soliton instability. As a result, a vortex lattice structure forms in the spatial directions perpendicular to the applied magnetic field. As a comparison, we also discuss the vector condensate in the Einstein-SU(2) Yang-Mills theory and find that in the setup of the present paper, the Einstein-Maxwell-complex vector field model is a generalization of the SU(2) model in the sense that the vector field has a general mass and gyromagnetic ratio

Casein kinase II protein kinase is bound to lamina-matrix and phosphorylates lamin-like protein in isolated pea nuclei

Science.gov (United States)

Li, H.; Roux, S. J.

1992-01-01

A casein kinase II (CK II)-like protein kinase was identified and partially isolated from a purified envelope-matrix fraction of pea (Pisum sativum L.) nuclei. When [gamma-32P]ATP was directly added to the envelope-matrix preparation, the three most heavily labeled protein bands had molecular masses near 71, 48, and 46 kDa. Protein kinases were removed from the preparation by sequential extraction with Triton X-100, EGTA, 0.3 M NaCl, and a pH 10.5 buffer, but an active kinase still remained bound to the remaining lamina-matrix fraction after these treatments. This kinase had properties resembling CK II kinases previously characterized from animal and plant sources: it preferred casein as an artificial substrate, could use GTP as efficiently as ATP as the phosphoryl donor, was stimulated by spermine, was calcium independent, and had a catalytic subunit of 36 kDa. Some animal and plant CK II kinases have regulatory subunits near 29 kDa, and a lamina-matrix-bound protein of this molecular mass was recognized on immunoblot by anti-Drosophila CK II polyclonal antibodies. Also found associated with the envelope-matrix fraction of pea nuclei were p34cdc2-like and Ca(2+)-dependent protein kinases, but their properties could not account for the protein kinase activity bound to the lamina. The 71-kDa substrate of the CK II-like kinase was lamin A-like, both in its molecular mass and in its cross-reactivity with anti-intermediate filament antibodies. Lamin phosphorylation is considered a crucial early step in the entry of cells into mitosis, so lamina-bound CK II kinases may be important control points for cellular proliferation.

Ribosomal subunit protein typing using matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) for the identification and discrimination of Aspergillus species.

Science.gov (United States)

Nakamura, Sayaka; Sato, Hiroaki; Tanaka, Reiko; Kusuya, Yoko; Takahashi, Hiroki; Yaguchi, Takashi

2017-04-26

Accurate identification of Aspergillus species is a very important subject. Mass spectral fingerprinting using matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) is generally employed for the rapid identification of fungal isolates. However, the results are based on simple mass spectral pattern-matching, with no peak assignment and no taxonomic input. We propose here a ribosomal subunit protein (RSP) typing technique using MALDI-TOF MS for the identification and discrimination of Aspergillus species. The results are concluded to be phylogenetic in that they reflect the molecular evolution of housekeeping RSPs. The amino acid sequences of RSPs of genome-sequenced strains of Aspergillus species were first verified and compared to compile a reliable biomarker list for the identification of Aspergillus species. In this process, we revealed that many amino acid sequences of RSPs (about 10-60%, depending on strain) registered in the public protein databases needed to be corrected or newly added. The verified RSPs were allocated to RSP types based on their mass. Peak assignments of RSPs of each sample strain as observed by MALDI-TOF MS were then performed to set RSP type profiles, which were then further processed by means of cluster analysis. The resulting dendrogram based on RSP types showed a relatively good concordance with the tree based on β-tubulin gene sequences. RSP typing was able to further discriminate the strains belonging to Aspergillus section Fumigati. The RSP typing method could be applied to identify Aspergillus species, even for species within section Fumigati. The discrimination power of RSP typing appears to be comparable to conventional β-tubulin gene analysis. This method would therefore be suitable for species identification and discrimination at the strain to species level. Because RSP typing can characterize the strains within section Fumigati, this method has potential as a powerful and reliable tool in

Transfer matrix in the quasiclassical approximation with constant and position-dependent mass, resonant tunneling

International Nuclear Information System (INIS)

Perez-Alvarez, R.; Rodriguez-Coppola, H.; Lopez-Gondar, J.; Izquierdo, M.L.

1987-11-01

We develop the quasiclassical approximation for the effective Hamiltonians describing nonhomogeneous systems and we deduce the wave function, the applicability conditions and the connection rules around the turning points. Based on the transfer matrix (TM) formalism we obtain expressions for the transmission coefficient of multiple barriers, the energy levels of multiple wells and the quasistationary levels of a well open by one, and by the two sides. The dispersion relation of a periodic potential profile with variable mass problem is also given. We discuss resonant tunneling for a system of multiple barriers. The transmission coefficient of such a barrier is maximum at energies close to the levels of the inner well when the end barriers are high enough and symmetric. (author). 20 refs, 1 fig

Influence of secondary structure on in-source decay of protein in matrix-assisted laser desorption/ionization mass spectrometry.

Science.gov (United States)

Takayama, Mitsuo; Osaka, Issey; Sakakura, Motoshi

2012-01-01

The susceptibility of the N-Cα bond of the peptide backbone to specific cleavage by in-source decay (ISD) in matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS) was studied from the standpoint of the secondary structure of three proteins. A naphthalene derivative, 5-amino-1-naphtol (5,1-ANL), was used as the matrix. The resulting c'-ions, which originate from the cleavage at N-Cα bonds in flexible secondary structures such as turn and bend, and are free from intra-molecular hydrogen-bonded α-helix structure, gave relatively intense peaks. Furthermore, ISD spectra of the proteins showed that the N-Cα bonds of specific amino acid residues, namely Gly-Xxx, Xxx-Asp, and Xxx-Asn, were more susceptible to MALDI-ISD than other amino acid residues. This is in agreement with the observation that Gly, Asp and Asn residues usually located in turns, rather than α-helix. The results obtained indicate that protein molecules embedded into the matrix crystal in the MALDI experiments maintain their secondary structures as determined by X-ray crystallography, and that MALDI-ISD has the capability for providing information concerning the secondary structure of protein.

Scenarios for waste management involving innovative systems (ADS)

International Nuclear Information System (INIS)

Tommasi, J.; Bottollier-Curtet, H.; Massara, S.; Varaine, F.; Delpech, M.

2001-01-01

The global performance of reactor park scenarios based on innovative systems (Accelerator-Driven Systems, ADS) for transmutation is studied, based either on equilibrium recycling states or on high burn-up systems. The results of these first studies are preliminary but allow to assess the main parameters of the fuel cycle (inventories, mass balances, mass flows...), to evaluate the specific contributions of ADS on the main scenario parameters, and to compare subcritical systems to critical ones. (author)

Shear-wave elastography quantitative assessment of the male breast: added value to distinguish benign and malignant palpable masses.

Science.gov (United States)

Crombé, Amandine; Hurtevent-Labrot, Gabrielle; Asad-Syed, Maryam; Palussière, Jean; MacGrogan, Gaetan; Kind, Michèle; Ferron, Stéphane

2018-02-01

To evaluate the ability of shear-wave elastography (SWE) to distinguish between benign and malignant palpable masses of the adult male breast. Clinical examination, mammography, B-mode and Doppler ultrasound findings and SWE quantitative parameters were compared in 50 benign lesions (including 40 gynaecomastias) and 15 malignant lesions (invasive ductal carcinomas) from 65 patients who were consecutively addressed for specialized advice at our comprehensive cancer centre. Mean elasticity (El mean), maximum elasticity (El max), El mean of the surrounding fatty tissue and lesion to fat ratio (El ratio) were reported for each patient. Malignant masses displayed significantly higher El mean (p masses without overlap of values between the two groups. By adding SWE to clinical examination, mammography and ultrasound, all the lesions would have been retrospectively correctly diagnosed as benign or malignant. One false positive could have been downstaged, 14/65 undetermined masses could have been correctly reclassified as 4 malignant and 10 benign lesions, for which biopsies could have consequently been avoided. Evaluation of male breast palpable masses by SWE demonstrates that malignant masses are significantly stiffer lesions and may improve diagnostic management when clinical examination, mammography and conventional ultrasound are doubtful. Advances in knowledge: Quantitative SWE is feasible in male breast and could be of great interest to help classify doubtful lesions after classical clinical and radiological evaluations, probably because of different anatomy and different tumours epidemiology compared with female breast.

One loop partition function of six dimensional conformal gravity using heat kernel on AdS

Energy Technology Data Exchange (ETDEWEB)

Lovreković, Iva [Institute for Theoretical Physics, Technische Universität Wien,Wiedner Hauptstrasse 8-10/136, A-1040 Vienna (Austria)

2016-10-13

We compute the heat kernel for the Laplacians of symmetric transverse traceless fields of arbitrary spin on the AdS background in even number of dimensions using the group theoretic approach introduced in http://dx.doi.org/10.1007/JHEP11(2011)010 and apply it on the partition function of six dimensional conformal gravity. The obtained partition function consists of the Einstein gravity, conformal ghost and two modes that contain mass.

Low scale gravity as the source of neutrino masses?

International Nuclear Information System (INIS)

Berezinsky, Veniamin; Narayan, Mohan; Vissani, Francesco

2005-01-01

We address the question whether low-scale gravity alone can generate the neutrino mass matrix needed to accommodate the observed phenomenology. In low-scale gravity the neutrino mass matrix in the flavor basis is characterized by one parameter (the gravity scale M X ) and by an exact or approximate flavor blindness (namely, all elements of the mass matrix are of comparable size). Neutrino masses and mixings are consistent with the observational data for certain values of the matrix elements, but only when the spectrum of mass is inverted or degenerate. For the latter type of spectra the parameter M ee probed in double beta experiments and the mass parameter probed by cosmology are close to existing upper limits

Application of targeted quantitative proteomics analysis in human cerebrospinal fluid using a liquid chromatography matrix-assisted laser desorption/ionization time-of-flight tandem mass spectrometer (LC MALDI TOF/TOF) platform.

Science.gov (United States)

Pan, Sheng; Rush, John; Peskind, Elaine R; Galasko, Douglas; Chung, Kathryn; Quinn, Joseph; Jankovic, Joseph; Leverenz, James B; Zabetian, Cyrus; Pan, Catherine; Wang, Yan; Oh, Jung Hun; Gao, Jean; Zhang, Jianpeng; Montine, Thomas; Zhang, Jing

2008-02-01

Targeted quantitative proteomics by mass spectrometry aims to selectively detect one or a panel of peptides/proteins in a complex sample and is particularly appealing for novel biomarker verification/validation because it does not require specific antibodies. Here, we demonstrated the application of targeted quantitative proteomics in searching, identifying, and quantifying selected peptides in human cerebrospinal spinal fluid (CSF) using a matrix-assisted laser desorption/ionization time-of-flight tandem mass spectrometer (MALDI TOF/TOF)-based platform. The approach involved two major components: the use of isotopic-labeled synthetic peptides as references for targeted identification and quantification and a highly selective mass spectrometric analysis based on the unique characteristics of the MALDI instrument. The platform provides high confidence for targeted peptide detection in a complex system and can potentially be developed into a high-throughput system. Using the liquid chromatography (LC) MALDI TOF/TOF platform and the complementary identification strategy, we were able to selectively identify and quantify a panel of targeted peptides in the whole proteome of CSF without prior depletion of abundant proteins. The effectiveness and robustness of the approach associated with different sample complexity, sample preparation strategies, as well as mass spectrometric quantification were evaluated. Other issues related to chromatography separation and the feasibility for high-throughput analysis were also discussed. Finally, we applied targeted quantitative proteomics to analyze a subset of previously identified candidate markers in CSF samples of patients with Parkinson's disease (PD) at different stages and Alzheimer's disease (AD) along with normal controls.

On excited states in real-time AdS/CFT

Energy Technology Data Exchange (ETDEWEB)

Botta-Cantcheff, Marcelo; Martínez, Pedro J.; Silva, Guillermo A. [Instituto de Física de La Plata - CONICET & Departamento de Física - UNLP,C.C. 67, 1900 La Plata (Argentina)

2016-02-25

The Skenderis-van Rees prescription, which allows the calculation of time-ordered correlation functions of local operators in CFT’s using holographic methods is studied and applied for excited states. Calculation of correlators and matrix elements of local CFT operators between generic in/out states are carried out in global Lorentzian AdS. We find the precise form of such states, obtain an holographic formula to compute the inner product between them, and using the consistency with other known prescriptions, we argue that the in/out excited states built according to the Skenderis-Van Rees prescription correspond to coherent states in the (large-N) AdS-Hilbert space. This is confirmed by explicit holographic computations. The outcome of this study has remarkable implications on generalizing the Hartle-Hawking construction for wave functionals of excited states in AdS quantum gravity.

Semi-analytical treatment of fracture/matrix flow in a dual-porosity simulator for unsaturated fractured rock masses

International Nuclear Information System (INIS)

Zimmerman, R.W.; Bodvarsson, G.S.

1992-04-01

A semi-analytical dual-porosity simulator for unsaturated flow in fractured rock masses has been developed. Fluid flow between the fracture network and the matrix blocks is described by analytical expressions that have been derived from approximate solutions to the imbibition equation. These expressions have been programmed into the unsaturated flow simulator, TOUGH, as a source/sink term. Flow processes are then simulated using only fracture elements in the computational grid. The modified code is used to simulate flow along single fractures, and infiltration into pervasively fractured formations

Composite glycerol/graphite/aromatic acid matrices for thin-layer chromatography/matrix-assisted laser desorption/ionization mass spectrometry of heterocyclic compounds.

Science.gov (United States)

Esparza, Cesar; Borisov, R S; Varlamov, A V; Zaikin, V G

2016-10-28

New composite matrices have been suggested for the analysis of mixtures of different synthetic organic compounds (N-containing heterocycles and erectile dysfunction drugs) by thin layer chromatography/matrix-assisted laser desorption ionization time-of-flight mass spectrometry (TLC/MALDI-TOF). Different mixtures of classical MALDI matrices and graphite particles dispersed in glycerol were used for the registration of MALDI mass spectra directly from TLC plates after analytes separation. In most of cases, the mass spectra possessed [M+H] + ions; however, for some analytes only [M+Na] + and [M+K] + ions were observed. These ions have been used to generate visualized TLC chromatograms. The described approach increases the desorption/ionization efficiencies of analytes separated by TLC, prevent spot blurring, simplifies and decrease time for sample preparation. Copyright © 2016 Elsevier B.V. All rights reserved.

Investigation of matrix effects in 193 nm laser ablation-inductively coupled plasma-mass spectrometry analysis using reference glasses of different transparencies

International Nuclear Information System (INIS)

Czas, J.; Jochum, K.P.; Stoll, B.; Weis, U.; Yang, Q.-C.; Jacob, D.E.; Andreae, M.O.

2012-01-01

The degree of transparency of glasses, which depends on the Fe content, may influence the ablation behavior during laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) analysis. To test possible matrix effects when using a 193 nm Nd:YAG laser, we have analyzed transparent and opaque NIST, BAM and USGS reference glasses. These reference materials are ideal for such investigations, because they are well characterized, most elements are homogeneously distributed at the micrometer scale, and their Fe content varies over a very large range, from 16 to 130,000 μg g −1 . Our measurements show that the fractionation factors of refractory and volatile lithophile elements, such as Sr, Ba, and Rb, are 1.00 ± 0.03 and independent of the degree of transparency. However, for volatile chalcophile/siderophile elements (e.g., Zn and Pb) the fractionation factors vary significantly between 0.7 and 1, depending on the spot sizes and the transparency of the material. Mass-load-induced matrix effects may also influence the accuracy of LA-ICP-MS analysis. They are less than 2% for the lithophile and up to 10% for volatile chalcophile/siderophile elements when the mass load varies by a factor 2.4. Relative sensitivity factors used for calibration of lithophile elements agree within uncertainty limits for transparent and opaque glasses when using a 193 nm laser. Even for volatile/chalcophile elements they differ only by 5–10%. The reliability of the LA-ICP-MS analyses is demonstrated by presenting concentration data of 27 trace elements in the NIST, BAM and USGS reference glasses using NIST SRM 612 for calibration, where highly accurate reference values are available. For trace element concentrations in the range between 1 and 500 μg g −1 , the reproducibility and the uncertainties at the 95% confidence level of the measurements vary between 1–4%, and 7–10%, respectively. - Highlights: ► Matrix effects are low for lithophile elements using a 193 nm laser

Matrix solid-phase dispersion followed by gas chromatography tandem mass spectrometry for the determination of benzotriazole UV absorbers in sediments.

Science.gov (United States)

Carpinteiro, I; Abuín, B; Ramil, M; Rodríguez, I; Cela, R

2012-01-01

A cost-effective and low solvent consumption method, based on the matrix solid-phase dispersion (MSPD) technique, for the determination of six benzotriazole UV absorbers in sediments is presented. Sieved samples (0.5 g) were first mixed in a mortar with a solid sorbent and then transferred to a polypropylene syringe containing a layer of clean-up co-sorbent. Analytes were eluted with a suitable solvent and further determined by gas chromatography with tandem mass spectrometry (GC-MS/MS). Under final conditions, diatomaceous earth and silica, deactivated to 10%, were used as inert dispersant and clean-up co-sorbent, respectively. Analytes were recovered using just 5 mL of dichloromethane, and this extract was concentrated and exchanged to 1 mL of isooctane. Further removal of co-extracted sulphur was achieved adding activated copper powder to final extracts, which were stored overnight, before injection in the GC-MS/MS system. The accuracy of the method was assessed with river and marine sediment samples showing different carbon contents and spiked at different concentrations in the range from 40 to 500 ng g(-1). Recoveries varied between 78% and 110% with associated standard deviations below 14%. The limits of quantification of the method stayed between 3 and 15 ng g(-1). Levels of target compounds in sediment samples ranged from not detected up to a maximum of 56 ng g(-1) for Tinuvin 328.

Low scale gravity as the source of neutrino masses?

Energy Technology Data Exchange (ETDEWEB)

Berezinsky, Veniamin [INFN, Laboratori Nazionali del Gran Sasso, I-67010 Assergi, AQ (Italy); Narayan, Mohan [INFN, Laboratori Nazionali del Gran Sasso, I-67010 Assergi, AQ (Italy); Vissani, Francesco [INFN, Laboratori Nazionali del Gran Sasso, I-67010 Assergi, AQ (Italy)

2005-04-01

We address the question whether low-scale gravity alone can generate the neutrino mass matrix needed to accommodate the observed phenomenology. In low-scale gravity the neutrino mass matrix in the flavor basis is characterized by one parameter (the gravity scale M{sub X}) and by an exact or approximate flavor blindness (namely, all elements of the mass matrix are of comparable size). Neutrino masses and mixings are consistent with the observational data for certain values of the matrix elements, but only when the spectrum of mass is inverted or degenerate. For the latter type of spectra the parameter M{sub ee} probed in double beta experiments and the mass parameter probed by cosmology are close to existing upper limits.

Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry for Direct Bacterial Identification from Positive Blood Culture Pellets ▿

OpenAIRE

Prod'hom, Guy; Bizzini, Alain; Durussel, Christian; Bille, Jacques; Greub, Gilbert

2010-01-01

An ammonium chloride erythrocyte-lysing procedure was used to prepare a bacterial pellet from positive blood cultures for direct matrix-assisted laser desorption-ionization time of flight (MALDI-TOF) mass spectrometry analysis. Identification was obtained for 78.7% of the pellets tested. Moreover, 99% of the MALDI-TOF identifications were congruent at the species level when considering valid scores. This fast and accurate method is promising.

Effective Majorana mass matrix from tau and pseudoscalar meson lepton number violating decays

Science.gov (United States)

Abada, Asmaa; De Romeri, Valentina; Lucente, Michele; Teixeira, Ana M.; Toma, Takashi

2018-02-01

An observation of any lepton number violating process will undoubtedly point towards the existence of new physics and indirectly to the clear Majorana nature of the exchanged fermion. In this work, we explore the potential of a minimal extension of the Standard Model via heavy sterile fermions with masses in the [0.1 - 10] GeV range concerning an extensive array of "neutrinoless" meson and tau decay processes. We assume that the Majorana neutrinos are produced on-shell, and focus on three-body decays. We conduct an update on the bounds on the active-sterile mixing elements, |{U}_{ℓ }{{}{_{α}}}_4{U}_{ℓ }{{}{_{β}}}_4| , taking into account the most recent experimental bounds (and constraints) and new theoretical inputs, as well as the effects of a finite detector, imposing that the heavy neutrino decay within the detector. This allows to establish up-to-date comprehensive constraints on the sterile fermion parameter space. Our results suggest that the branching fractions of several decays are close to current sensitivities (likely within reach of future facilities), some being already in conflict with current data (as is the case of K + → ℓ α + ℓ β + π -, and τ - → μ +π-π-). We use these processes to extract constraints on all entries of an enlarged definition of a 3 × 3 "effective" Majorana neutrino mass matrix m ν αβ .

Aroma behaviour during steam cooking within a potato starch-based model matrix.

Science.gov (United States)

Descours, Emilie; Hambleton, Alicia; Kurek, Mia; Debeaufort, Fréderic; Voilley, Andrée; Seuvre, Anne-Marie

2013-06-05

To help understand the organoleptic qualities of steam cooked foods, the kinetics of aroma release during cooking in a potato starch based model matrix was studied. Behaviour of components having a major impact in potato flavour were studied using solid phase micro extraction-gas chromatography (SPME-GC). Evolution of microstructure of potato starch model-matrix during steam cooking process was analyzed using environmental scanning electron microscopy (ESEM). Both aroma compounds that are naturally present in starch matrix and those that were added were analyzed. Both the aroma compounds naturally presented and those added had different behaviour depending on their physico-chemical properties (hydrophobicity, saturation vapour pressure, molecular weight, etc.). The physical state of potato starch influences of the retention of aromatized matrix with Starch gelatinization appearing to be the major phenomenon influencing aroma release. Copyright © 2013 Elsevier Ltd. All rights reserved.

The ADS/QCD correspondence and exclusive processes

International Nuclear Information System (INIS)

Brodsky, Stanley J.; De Teramond, Guy F.; Deur, Alexandre

2011-01-01

The AdS/CFT correspondence between theories in AdS space and conformal field theories in physical space-time provides an analytic, semi-classical, color-confining model for strongly-coupled QCD. The soft-wall AdS/QCD model, modified by a positive-sign dilaton metric, leads to a remarkable one-parameter description of nonperturbative hadron dynamics at zero quark mass, including a zero-mass pion and meson and baryon Regge spectra of linear trajectories with the same slope in orbital angular momentum L and radial quantum number n. One also predicts the form of the non-perturbative effective coupling alpha AdS/s (Q) and its Beta-function which agrees with the effective coupling alphag1 extracted from the Bjorken sum rule. Light-front holography, which connects the fifth-dimensional coordinate of AdS space z to an invariant impact separation variable zeta, allows one to compute the analytic form of the frame-independent light-front wave functions, the fundamental entities which encode hadron properties as well as decay constants, form factors, deeply-virtual Compton scattering, exclusive heavy hadron decays, and other exclusive scattering amplitudes. One thus obtains a relativistic description of hadrons in QCD at the amplitude level with dimensional counting for exclusive reactions at high momentum transfer. As specific examples, we discuss the behavior of the pion and nucleon form factors in the space-like and time-like regions. We also review the phenomenology of exclusive processes including some anomalous empirical results.

The behaviour under irradiation of molybdenum matrix for inert matrix fuel containing americium oxide (CerMet concept)

Energy Technology Data Exchange (ETDEWEB)

D' Agata, E., E-mail: elio.dagata@ec.europa.eu [European Commission, Joint Research Centre, Institute for Energy and Transport, P.O. Box 2, 1755 ZG Petten (Netherlands); Knol, S.; Fedorov, A.V. [Nuclear Research and Consultancy Group, P.O. Box 25, 1755 ZG Petten (Netherlands); Fernandez, A.; Somers, J. [European Commission, Joint Research Centre, Institute for Transuranium Elements, P.O. Box 2340, 76125 Karlsruhe (Germany); Klaassen, F. [Nuclear Research and Consultancy Group, P.O. Box 25, 1755 ZG Petten (Netherlands)

2015-10-15

Americium is a strong contributor to the long term radiotoxicity of high activity nuclear waste. Transmutation by irradiation in nuclear reactors or Accelerator Driven System (ADS, subcritical reactors dedicated to transmutation) of long-lived nuclides like {sup 241}Am is therefore an option for the reduction of radiotoxicity of waste packages to be stored in a repository. In order to safely burn americium in a fast reactor or ADS, it must be incorporated in a matrix that could be metallic (CerMet target) or ceramic (CerCer target). One of the most promising matrix to incorporate Am is molybdenum. In order to address the issues (swelling, stability under irradiation, gas retention and release) of using Mo as matrix to transmute Am, two irradiation experiments have been conducted recently at the High Flux Reactor (HFR) in Petten (The Netherland) namely HELIOS and BODEX. The BODEX experiment is a separate effect test, where the molybdenum behaviour is studied without the presence of fission products using {sup 10}B to “produce” helium, the HELIOS experiment included a more representative fuel target with the presence of Am and fission product. This paper covers the results of Post Irradiation Examination (PIE) of the two irradiation experiments mentioned above where molybdenum behaviour has been deeply investigated as possible matrix to transmute americium (CerMet fuel target). The behaviour of molybdenum looks satisfying at operating temperature but at high temperature (above 1000 °C) more investigation should be performed.

Recent advances in matrix-assisted laser desorption/ionisation mass spectrometry imaging (MALDI-MSI) for in situ analysis of endogenous molecules in plants.

Science.gov (United States)

Qin, Liang; Zhang, Yawen; Liu, Yaqin; He, Huixin; Han, Manman; Li, Yanyan; Zeng, Maomao; Wang, Xiaodong

2018-04-17

Mass spectrometry imaging (MSI) as a label-free and powerful imaging technique enables in situ evaluation of a tissue metabolome and/or proteome, becoming increasingly popular in the detection of plant endogenous molecules. The characterization of structure and spatial information of endogenous molecules in plants are both very important aspects to better understand the physiological mechanism of plant organism. Matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) is a commonly-used tissue imaging technique, which requires matrix to assist in situ detection of a variety of molecules on the surface of a tissue section. In previous studies, MALDI-MSI was mostly used for the detection of molecules from animal tissue sections, compared to plant samples due to cell structural limitations, such as plant cuticles, epicuticular waxes, and cell walls. Despite the enormous progress that has been made in tissue imaging, there is still a challenge for MALDI-MSI suitable for the imaging of endogenous compounds in plants. This review summarises the recent advances in MALDI-MSI, focusing on the application of in situ detection of endogenous molecules in different plant organs, i.e. root, stem, leaf, flower, fruit, and seed. Further improvements on instrumentation sensitivity, matrix selection, image processing and sample preparation will expand the application of MALDI-MSI in plant research. Copyright © 2018 John Wiley & Sons, Ltd.

AdS2 holographic dictionary

International Nuclear Information System (INIS)

Cvetič, Mirjam; Papadimitriou, Ioannis

2016-01-01

We construct the holographic dictionary for both running and constant dilaton solutions of the two dimensional Einstein-Maxwell-Dilaton theory that is obtained by a circle reduction from Einstein-Hilbert gravity with negative cosmological constant in three dimensions. This specific model ensures that the dual theory has a well defined ultraviolet completion in terms of a two dimensional conformal field theory, but our results apply qualitatively to a wider class of two dimensional dilaton gravity theories. For each type of solutions we perform holographic renormalization, compute the exact renormalized one-point functions in the presence of arbitrary sources, and derive the asymptotic symmetries and the corresponding conserved charges. In both cases we find that the scalar operator dual to the dilaton plays a crucial role in the description of the dynamics. Its source gives rise to a matter conformal anomaly for the running dilaton solutions, while its expectation value is the only non trivial observable for constant dilaton solutions. The role of this operator has been largely overlooked in the literature. We further show that the only non trivial conserved charges for running dilaton solutions are the mass and the electric charge, while for constant dilaton solutions only the electric charge is non zero. However, by uplifting the solutions to three dimensions we show that constant dilaton solutions can support non trivial extended symmetry algebras, including the one found by Compère, Song and Strominger http://dx.doi.org/10.1007/JHEP05(2013)152, in agreement with the results of Castro and Song http://arxiv.org/abs/1411.1948. Finally, we demonstrate that any solution of this specific dilaton gravity model can be uplifted to a family of asymptotically AdS 2 ×S 2 or conformally AdS 2 ×S 2 solutions of the STU model in four dimensions, including non extremal black holes. The four dimensional solutions obtained by uplifting the running dilaton solutions coincide

Supersymmetric AdS3, AdS2 and bubble solutions

International Nuclear Information System (INIS)

Gauntlett, Jerome P.; Waldram, Daniel; Kim, Nakwoo

2007-01-01

We present new supersymmetric AdS 3 solutions of type IIB supergravity and AdS 2 solutions of D = 11 supergravity. The former are dual to conformal field theories in two dimensions with N = (0, 2) supersymmetry while the latter are dual to conformal quantum mechanics with two supercharges. Our construction also includes AdS 2 solutions of D = 11 supergravity that have non-compact internal spaces which are dual to three-dimensional N = 2 superconformal field theories coupled to point-like defects. We also present some new bubble-type solutions, corresponding to BPS states in conformal theories, that preserve four supersymmetries

Drawing a different picture with pencil lead as matrix-assisted laser desorption/ionization matrix for fullerene derivatives.

Science.gov (United States)

Nye, Leanne C; Hungerbühler, Hartmut; Drewello, Thomas

2018-02-01

Inspired by reports on the use of pencil lead as a matrix-assisted laser desorption/ionization matrix, paving the way towards matrix-free matrix-assisted laser desorption/ionization, the present investigation evaluates its usage with organic fullerene derivatives. Currently, this class of compounds is best analysed using the electron transfer matrix trans-2-[3-(4-tert-butylphenyl)-2-methyl-2-propenylidene] malononitrile (DCTB), which was employed as the standard here. The suitability of pencil lead was additionally compared to direct (i.e. no matrix) laser desorption/ionization-mass spectrometry. The use of (DCTB) was identified as the by far gentler method, producing spectra with abundant molecular ion signals and much reduced fragmentation. Analytically, pencil lead was found to be ineffective as a matrix, however, appears to be an extremely easy and inexpensive method for producing sodium and potassium adducts.

Semiclassical S-matrix for black holes

CERN Document Server

Bezrukov, Fedor; Sibiryakov, Sergey

2015-01-01

We propose a semiclassical method to calculate S-matrix elements for two-stage gravitational transitions involving matter collapse into a black hole and evaporation of the latter. The method consistently incorporates back-reaction of the collapsing and emitted quanta on the metric. We illustrate the method in several toy models describing spherical self-gravitating shells in asymptotically flat and AdS space-times. We find that electrically neutral shells reflect via the above collapse-evaporation process with probability exp(-B), where B is the Bekenstein-Hawking entropy of the intermediate black hole. This is consistent with interpretation of exp(B) as the number of black hole states. The same expression for the probability is obtained in the case of charged shells if one takes into account instability of the Cauchy horizon of the intermediate Reissner-Nordstrom black hole. Our semiclassical method opens a new systematic approach to the gravitational S-matrix in the non-perturbative regime.

The Charged Lepton Mass Matrix and Non-zero θ13 with TeV Scale New Physics.

Science.gov (United States)

Rashed, Ahmed; Datta, Alakabha

2012-03-01

We provide an explicit structure of the charged lepton mass matrix which is 2-3 symmetric except for a single breaking of this symmetry by the muon mass. We identify a flavor symmetric limit for the mass matrices where the first generation is decoupled from the other two in the charged lepton sector while in the neutrino sector the third generation is decoupled from the first two generations. The leptonic mixing in the symmetric limit can be, among other structures, the bi-maximal (BM) or the tri-bimaximal (TBM) mixing. Symmetry breaking effects are included both in the charged lepton and the neutrino sector to produce corrections to the leptonic mixing and explain the recent θ13 measurements. A model that extends the SM by three right handed neutrinos, an extra Higgs doublet, and two singlet scalars is introduced to generate the leptonic mixing.[4pt] This work was supported in part by the US-Egypt Joint Board on Scientific and Technological Co-operation award (Project ID: 1855) administered by the US Department of Agriculture, summer grant from the College of Liberal Arts, University of Mississippi and in part by the National Science Foundation under Grant No. 1068052 and 1066293 and the hospitality of the Aspen Center for Physics.

Current status of matrix-assisted laser desorption ionisation-time of flight mass spectrometry in the clinical microbiology laboratory.

Science.gov (United States)

Kok, Jen; Chen, Sharon C A; Dwyer, Dominic E; Iredell, Jonathan R

2013-01-01

The integration of matrix-assisted laser desorption ionisation-time of flight mass spectrometry (MALDI-TOF MS) into many clinical microbiology laboratories has revolutionised routine pathogen identification. MALDI-TOF MS complements and has good potential to replace existing phenotypic identification methods. Results are available in a more clinically relevant timeframe, particularly in bacteraemic septic shock. Novel applications include strain typing and the detection of antimicrobial resistance, but these are not widely used. This review discusses the technical aspects, current applications, and limitations of MALDI-TOF MS.

A Natural Language for AdS/CFT Correlators

Energy Technology Data Exchange (ETDEWEB)

Fitzpatrick, A.Liam; /Boston U.; Kaplan, Jared; /SLAC; Penedones, Joao; /Perimeter Inst. Theor. Phys.; Raju, Suvrat; /Harish-Chandra Res. Inst.; van Rees, Balt C.; /YITP, Stony Brook

2012-02-14

We provide dramatic evidence that 'Mellin space' is the natural home for correlation functions in CFTs with weakly coupled bulk duals. In Mellin space, CFT correlators have poles corresponding to an OPE decomposition into 'left' and 'right' sub-correlators, in direct analogy with the factorization channels of scattering amplitudes. In the regime where these correlators can be computed by tree level Witten diagrams in AdS, we derive an explicit formula for the residues of Mellin amplitudes at the corresponding factorization poles, and we use the conformal Casimir to show that these amplitudes obey algebraic finite difference equations. By analyzing the recursive structure of our factorization formula we obtain simple diagrammatic rules for the construction of Mellin amplitudes corresponding to tree-level Witten diagrams in any bulk scalar theory. We prove the diagrammatic rules using our finite difference equations. Finally, we show that our factorization formula and our diagrammatic rules morph into the flat space S-Matrix of the bulk theory, reproducing the usual Feynman rules, when we take the flat space limit of AdS/CFT. Throughout we emphasize a deep analogy with the properties of flat space scattering amplitudes in momentum space, which suggests that the Mellin amplitude may provide a holographic definition of the flat space S-Matrix.

Reproducibility of serum protein profiling by systematic assessment using solid-phase extraction and matrix-assisted laser desorption/ionization mass spectrometry

DEFF Research Database (Denmark)

Callesen, Anne K; Christensen, René Depont; Madsen, Jonna S

2008-01-01

for serum protein profiling we investigated a range of sample preparation techniques and developed a statistical method based on repeated analyses for evaluation of protein-profiling performance of MALDI MS. Two different solid-phase extraction (SPE) methods were investigated, namely custom......Protein profiling of human serum by matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS) is potentially a new diagnostic tool for early detection of human diseases, including cancer. Sample preparation is a key issue in MALDI MS and the analysis of complex samples such as serum......-made microcolumns and commercially available magnetic beads. Using these two methods, nineteen different sample preparation methods for serum profiling by MALDI MS were systematically tested with regard to matrix selection, stationary phase, selectivity, and reproducibility. Microcolumns were tested with regard...

The AdS/QCD Correspondence and Exclusive Processes

International Nuclear Information System (INIS)

Brodsky, Stanley

2010-01-01

The AdS/CFT correspondence between theories in AdS space and conformal field theories in physical space-time provides an analytic, semi-classical, color-confining model for strongly-coupled QCD. The soft-wall AdS/QCD model modified by a positive-sign dilaton metric leads to a remarkable one-parameter description of nonperturbative hadron dynamics at zero quark mass, including a zero-mass pion and a Regge spectrum of linear trajectories with the same slope in orbital angular momentum L and radial quantum number n for both mesons and baryons. One also predicts the form of the non-perturbative effective coupling α s AdS (q) and its β-function which agrees with the effective coupling α ga extracted from the Bjorken sum rule. Light-front holography, which connects the fifth-dimensional coordinate of AdS space z to an invariant impact separation variable ζ, allows one to compute the analytic form of the frame-independent light-front wavefunctions, the fundamental entities which encode hadron properties as well as decay constants, form factors, deeply virtual Compton scattering, exclusive heavy hadron decays and other exclusive scattering amplitudes. One thus obtains a relativistic description of hadrons in QCD at the amplitude level with dimensional counting for hard exclusive reactions at high momentum transfer. As specific examples we discuss the behavior of the pion and nucleon form factors in the space-like and time-like regions. We also review the phenomenology of exclusive processes including some anomalous empirical results.

Independent effects of adding weight and inertia on balance during quiet standing.

Science.gov (United States)

Costello, Kerry Elizabeth; Matrangola, Sara Louise; Madigan, Michael Lawrence

2012-04-16

Human balance during quiet standing is influenced by adding mass to the body with a backpack, with symmetrically-applied loads to the trunk, or with obesity. Adding mass to the body increases both the weight and inertia of the body, which theoretically could provide counteracting effects on body dynamics and balance. Understanding the independent effects of adding weight and inertia on balance may provide additional insight into human balance that could lead to novel advancements in balance training and rehabilitation. Therefore, the purpose of this study was to investigate the independent effects of adding weight and inertia on balance during quiet standing. Sixteen normal-weight young adult participants stood as still as possible on a custom-built backboard apparatus under four experimental conditions: baseline, added inertia only, added weight only, and added inertia and weight. Adding inertia by itself had no measurable effect on center of pressure movement or backboard movement. Adding weight by itself increased center of pressure movement (indicated greater effort by the postural control system to stand as still as possible) and backboard movement (indicating a poorer ability of the body to stand as still as possible). Adding inertia and weight at the same time increased center of pressure movement but did not increase backboard movement compared to the baseline condition. Adding inertia and adding weight had different effects on balance. Adding inertia by itself had no effect on balance. Adding weight by itself had a negative effect on balance. When adding inertia and weight at the same time, the added inertia appeared to lessen (but did not eliminate) the negative effect of adding weight on balance. These results improve our fundamental understanding of how added mass influences human balance.

Evaluation of matrix effect in isotope dilution mass spectrometry based on quantitative analysis of chloramphenicol residues in milk powder

International Nuclear Information System (INIS)

Li, Xiu Qin; Yang, Zong; Zhang, Qing He; Li, Hong Mei

2014-01-01

Graphical abstract: -- Highlights: •We develop a strategy to evaluate matrix effect and its impact on the IDMS results. •Matrix effect and IDMS correction factor from different conditions are evaluated. •Ion suppression effect is observed in LLE and HLB pre-treated sample solutions. •Ion enhancement effect is found in MCX pre-treated sample solution. •IDMS correction factor in HLB and MCX solutions in three instruments is close to 1 -- Abstract: In the present study, we developed a comprehensive strategy to evaluate matrix effect (ME) and its impact on the results of isotope dilution mass spectrometry (IDMS) in analysis of chloramphenicol (CAP) residues in milk powder. Stable isotope-labeled internal standards do not always compensate ME, which brings the variation of the ratio (the peak area of analyte/the peak area of isotope). In our investigation, impact factors of this variation were studied in the extraction solution of milk powder using three mass spectrometers coupled with different ion source designs, and deuterium-labeled chloramphenicol (D5-CAP) was used as the internal standard. ME from mobile phases, sample solvents, pre-treatment methods, sample origins and instruments was evaluated, and its impact on the results of IDMS was assessed using the IDMS correction factor (θ). Our data showed that the impact of ME of mobile phase on the correction factor was significantly greater than that of sample solvent. Significant ion suppression and enhancement effects were observed in different pre-treated sample solutions. The IDMS correction factor in liquid–liquid extraction (LLE) and molecular imprinted polymer (MIP) extract with different instruments was greater or less 1.0, and the IDMS correction factor in hydrophilic lipophilic balance (HLB) and mix-mode cation exchange (MCX) extract with different instruments was all close to 1.0. To the instrument coupled with different ion source design, the impact of ME on IDMS quantitative results was

Salivary gland masses. Dynamic MR imaging and pathologic correlation

International Nuclear Information System (INIS)

Park, Jinho; Inoue, Shingo; Ishizuka, Yasuhito; Shindo, Hiroaki; Kawanishi, Masayuki; Kakizaki, Dai; Abe, Kimihiko; Ebihara, Yoshiro

1997-01-01

To evaluate the efficiency of dynamic contrast-enhanced magnetic resonance imaging (MRI) for the diagnosis of salivary gland masses. We retrospectively examined 19 salivary gland masses that were pathologically diagnosed by surgical operation or biopsy. We obtained T1- and T2-weighted images on MRI, performed dynamic studies on each mass and examined the correlation between enhancement patterns and pathological findings. Four enhancement patterns were recognized on contrast-enhanced MRI: type 1 showed marked, homogeneous enhancement; type 2 slights, homogeneous enhancement; type 3 marginal enhancement; and type 4 poor enhancement of the mass. Most pleomorphic adenomas had a type 1 enhancement pattern, but two had a type 2 pattern. Pathologically, each mass enhancement pattern had different tumor cell and matrix components. Warthin's tumor generally showed the type 4 pattern. Primary malignant tumors of the salivary gland all showed the type 3 pattern, and pathological specimens showed many tumor cells along the marginal portion of the tumor. One inflammatory cyst and one Warthin's tumor also showed the type 3 pattern. Except for metastatic renal cell carcinoma, the enhancement patterns of late phase images and dynamic study images were the same. Dynamic MRI added little diagnostic information about salivary gland masses, but the contrast-enhanced MR features correlated well with the pathological findings. (author)

Short communication: Identification of subclinical cow mastitis pathogens in milk by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry.

Science.gov (United States)

Barreiro, J R; Ferreira, C R; Sanvido, G B; Kostrzewa, M; Maier, T; Wegemann, B; Böttcher, V; Eberlin, M N; dos Santos, M V

2010-12-01

Subclinical mastitis is a common and easily disseminated disease in dairy herds. Its routine diagnosis via bacterial culture and biochemical identification is a difficult and time-consuming process. In this work, we show that matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) allows bacterial identification with high confidence and speed (1 d for bacterial growth and analysis). With the use of MALDI-TOF MS, 33 bacterial culture isolates from milk of different dairy cows from several farms were analyzed, and the results were compared with those obtained by classical biochemical methods. This proof-of-concept case demonstrates the reliability of MALDI-TOF MS bacterial identification, and its increased selectivity as illustrated by the additional identification of coagulase-negative Staphylococcus species and mixed bacterial cultures. Matrix-assisted laser desorption-ionization mass spectrometry considerably accelerates the diagnosis of mastitis pathogens, especially in cases of subclinical mastitis. More immediate and efficient animal management strategies for mastitis and milk quality control in the dairy industry can therefore be applied. Copyright © 2010 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Differentiation of Clinically Relevant mucorales Rhizopus microsporus and R. arrhizus by Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry (MALDI-TOF MS)

NARCIS (Netherlands)

Dolatabadi, S.; Kolecka, A.; Versteeg, Matthijs; de Hoog, Sybren G; Boekhout, Teun

This study addresses the usefulness of Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry (MALDI-TOF MS) for reliable identification of the two most frequently occuring clinical species of Rhizopus, namely R. arrhizus with its two varieties arrhizus and delemar and R.

Matrix-assisted laser desorption/ionization-time of flight mass spectrometry identification of large colony beta-hemolytic streptococci containing Lancefield groups A, C, and G

DEFF Research Database (Denmark)

Salgård Jensen, Christian; Dam-Nielsen, Casper; Arpi, Magnus

2015-01-01

BACKGROUND: The aim of this study was to investigate whether large colony beta-hemolytic streptococci containing Lancefield groups A, C, and G can be adequately identified using matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-ToF). Previous studies show varying...

Rapid Identification of the Foodborne Pathogen Trichinella spp. by Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry.

Directory of Open Access Journals (Sweden)

Anne Mayer-Scholl

Full Text Available Human trichinellosis occurs through consumption of raw or inadequately processed meat or meat products containing larvae of the parasitic nematodes of the genus Trichinella. Currently, nine species and three genotypes are recognized, of which T. spiralis, T. britovi and T. pseudospiralis have the highest public health relevance. To date, the differentiation of the larvae to the species and genotype level is based primarily on molecular methods, which can be relatively time consuming and labor intensive. Due to its rapidness and ease of use a matrix assisted laser desorption / ionization time of flight mass spectrometry (MALDI-TOF MS reference spectra database using Trichinella strains of all known species and genotypes was created. A formicacid/acetonitrile protein extraction was carried out after pooling 10 larvae of each Trichinella species and genotype. Each sample was spotted 9 times using α-cyano 4-hydoxy cinnamic acid matrix and a MicroFlex LT mass spectrometer was used to acquire 3 spectra (m/z 2000 to 20000 Da from each spot resulting in 27 spectra/species or genotype. Following the spectra quality assessment, Biotyper software was used to create a main spectra library (MSP representing nine species and three genotypes of Trichinella. The evaluation of the spectra generated by MALDI-TOF MS revealed a classification which was comparable to the results obtained by molecular methods. Also, each Trichinella species utilized in this study was distinct and distinguishable with a high confidence level. Further, different conservation methods such as freezing and conservation in alcohol and the host species origin of the isolated larvae did not have a significant influence on the generated spectra. Therefore, the described MALDI-TOF MS can successfully be implemented for both genus and species level identification and represents a major step forward in the use of this technique in foodborne parasitology.

Texture zeros and hierarchical masses from flavour (mis)alignment

Science.gov (United States)

Hollik, W. G.; Saldana-Salazar, U. J.

2018-03-01

We introduce an unconventional interpretation of the fermion mass matrix elements. As the full rotational freedom of the gauge-kinetic terms renders a set of infinite bases called weak bases, basis-dependent structures as mass matrices are unphysical. Matrix invariants, on the other hand, provide a set of basis-independent objects which are of more relevance. We employ one of these invariants to give a new parametrisation of the mass matrices. By virtue of it, one gains control over its implicit implications on several mass matrix structures. The key element is the trace invariant which resembles the equation of a hypersphere with a radius equal to the Frobenius norm of the mass matrix. With the concepts of alignment or misalignment we can identify texture zeros with certain alignments whereas Froggatt-Nielsen structures in the matrix elements are governed by misalignment. This method allows further insights of traditional approaches to the underlying flavour geometry.

Influence of Culture Media on Detection of Carbapenem Hydrolysis by Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry.

Science.gov (United States)

Ramos, Ana Carolina; Carvalhaes, Cecília Godoy; Cordeiro-Moura, Jhonatha Rodrigo; Rockstroh, Anna Carolina; Machado, Antonia Maria Oliveira; Gales, Ana Cristina

2016-07-01

In this study, we evaluated the influence of distinct bacterial growth media on detection of carbapenemase hydrolysis by matrix-assisted laser desorption ionization-time of flight mass spectrometry. False-negative results were observed for OXA-25-, OXA-26-, and OXA-72-producing Acinetobacter baumannii isolates grown on MacConkey agar medium. The other culture media showed 100% sensitivity and 100% specificity for detecting carbapenemase. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Determination of rare earth elements in high purity rare earth oxides by liquid chromatography, thermionic mass spectrometry and combined liquid chromatography/thermionic mass spectrometry

International Nuclear Information System (INIS)

Stijfhoorn, D.E.; Stray, H.; Hjelmseth, H.

1993-01-01

A high-performance liquid chromatographic (HPLC) method for the determination of rare earth elements in rocks has been modified and used for the determination of rare earth elements (REE) in high purity rare earth oxides. The detection limit was 1-1.5 ng or 2-3 mg/kg when a solution corresponding to 0.5 mg of the rare earth oxide was injected. The REE determination was also carried out by adding a mixture of selected REE isotopes to the sample and analysing the collected HPLC-fractions by mass spectrometry (MS) using a thermionic source. Since the matrix element was not collected, interference from this element during the mass spectrometric analysis was avoided. Detection limits as low as 0.5 mg/kg could then be obtained. Detection limits as low as 0.05 mg/kg were possible by MS without HPLC-pre-separation, but this approach could only be used for those elements that were not affected by the matrix. Commercial samples of high purity Nd 2 O 3 , Gd 2 O 3 and Dy 2 O 3 were analysed in this study, and a comparison of results obtained by HPLC, combined HPLC/MS and direct MS is presented. (Author)

Strings on AdS2 and the high-energy limit of noncritical M-theory

International Nuclear Information System (INIS)

Horava, Petr; Horava, Petr; Keeler, Cynthia A.

2007-01-01

Noncritical M-theory in 2+1 dimensions has been defined as a double-scaling limit of a nonrelativistic Fermi liquid on a flat two-dimensional plane. Here we study this noncritical M-theory in the limit of high energies, analogous to the alpha(prime) → ∞ limit of string theory. In the related case of two-dimensional Type 0A strings, it has been argued that the conformal alpha(prime) → ∞ limit leads to AdS 2 with a propagating fermion whose mass is set by the value of the RR flux. Here we provide evidence that in the high-energy limit, the natural ground state of noncritical M-theory similarly describes the AdS 2 x S 1 spacetime, with a massless propagating fermion. We argue that the spacetime effective theory in this background is captured by a topological higher-spin extension of conformal Chern-Simons gravity in 2+1 dimensions, consistently coupled to a massless Dirac field. Intriguingly, the two-dimensional plane populated by the original nonrelativistic fermions is essentially the twistor space associated with the symmetry group of the AdS 2 x S 1 spacetime; thus, at least in the high-energy limit, noncritical M-theory can be nonperturbatively described as a 'Fermi liquid on twistor space'

Studies Involving Immobilization Of Hazardous Wastes In Cement-ilmenite Matrix

International Nuclear Information System (INIS)

El-Dakrory, A.M.; Sayed, M.S.; Adham, K.

1999-01-01

Ilmenite was added to Ordinary Portland Cement to Modify the characteristic properties of the matrix as density, compressive strength and thermal stability . Coal tar and radiocesium were solidified as hazardous waste in cement-ilmenite matrix. The physical properties as density, sitting times and porosity were studied. The mechanical properties as compressive strength values and the chemical properties as leaching were measured

Fabrication of Nano-CeO2 and Application of Nano-CeO2 in Fe Matrix Composites

International Nuclear Information System (INIS)

Tiebao, W.; Chunxiang, C.; Xiaodong, W.; Guobin, L.

2010-01-01

It is expatiated that nano-CeO2 is fabricated by the direct sedimentation method. The components and particles diameter of nano-CeO2 powders are analyzed by XRD and SEM . The thermodynamic analysis and acting mechanism of nano-CeO2 with Al in Fe matrix composites are researched, which shows that the reaction is generated between CeO2 and Al in the composite, that is, 3CeO2+4Al - 2Al2O3+3[Ce], which obtains Al2O3 and active [Ce] during the sintering process. The active [Ce] can improve the performance of CeO2/Fe matrix composites. The suitable amount of CeO2 is about 0.05% in CeO2/Fe matrix composites. SEM fracture analysis shows that the toughness sockets in nano-CeO2/Fe matrix composites are more than those in no-added nano-CeO2 composites, which can explain that adding nano-CeO2 into Fe matrix composite, the toughness of the composite is improved significantly. Applied nano-CeO2 to Fe matrix diamond saw blades shows that Fe matrix diamond saw blade is sharper and of longer cutting life than that with no-added nano-CeO2.

Imaging mass spectrometry (IMS) of cortical lipids from preclinical to severe stages of Alzheimer's disease.

Science.gov (United States)

Gónzalez de San Román, E; Manuel, I; Giralt, M T; Ferrer, I; Rodríguez-Puertas, R

2017-09-01

Alzheimer's disease (AD) is a progressive neurodegenerative disease affecting millions of patients worldwide. Previous studies have demonstrated alterations in the lipid composition of lipid extracts from plasma and brain samples of AD patients. However, there is no consensus regarding the qualitative and quantitative changes of lipids in brains from AD patients. In addition, the recent developments in imaging mass spectrometry methods are leading to a new stage in the in situ analysis of lipid species in brain tissue slices from human postmortem samples. The present study uses the matrix-assisted laser desorption/ionization imaging mass spectrometry (MALDI-IMS), permitting the direct anatomical analysis of lipids in postmortem brain sections from AD patients, which are compared with the intensity of the lipid signal in samples from matched subjects with no neurological diseases. The frontal cortex samples from AD patients were classified in three groups based on Braak's histochemical criteria, ranging from non-cognitively impaired patients to those severely affected. The main results indicate a depletion of different sulfatide lipid species from the earliest stages of the disease in both white and gray matter areas of the frontal cortex. Therefore, the decrease in sulfatides in cortical areas could be considered as a marker of the disease, but may also indicate neurochemical modifications related to the pathogenesis of the disease. This article is part of a Special Issue entitled: Membrane Lipid Therapy: Drugs Targeting Biomembranes edited by Pablo V. Escribá. Copyright © 2017 Elsevier B.V. All rights reserved.

Nonnegative Matrix Factorizations Performing Object Detection and Localization

Directory of Open Access Journals (Sweden)

G. Casalino

2012-01-01

Full Text Available We study the problem of detecting and localizing objects in still, gray-scale images making use of the part-based representation provided by nonnegative matrix factorizations. Nonnegative matrix factorization represents an emerging example of subspace methods, which is able to extract interpretable parts from a set of template image objects and then to additively use them for describing individual objects. In this paper, we present a prototype system based on some nonnegative factorization algorithms, which differ in the additional properties added to the nonnegative representation of data, in order to investigate if any additional constraint produces better results in general object detection via nonnegative matrix factorizations.

Asymptotic Bethe ansatz S-matrix and Landau-Lifshitz-type effective 2d actions

International Nuclear Information System (INIS)

Roiban, R; Tirziu, A; Tseytlin, A A

2006-01-01

Motivated by the desire to relate Bethe ansatz equations for anomalous dimensions found on the gauge-theory side of the AdS/CFT correspondence to superstring theory on AdS 5 x S 5 we explore a connection between the asymptotic S-matrix that enters the Bethe ansatz and an effective two-dimensional quantum field theory. The latter generalizes the standard 'non-relativistic' Landau-Lifshitz (LL) model describing low-energy modes of ferromagnetic Heisenberg spin chain and should be related to a limit of superstring effective action. We find the exact form of the quartic interaction terms in the generalized LL-type action whose quantum S-matrix matches the low-energy limit of the asymptotic S-matrix of the spin chain of Beisert, Dippel and Staudacher (BDS). This generalizes to all orders in the 't Hooft coupling λ an earlier computation of Klose and Zarembo of the S-matrix of the standard LL model. We also consider a generalization to the case when the spin-chain S-matrix contains an extra 'string' phase and determine the exact form of the LL 4-vertex corresponding to the low-energy limit of the ansatz of Arutyunov, Frolov and Staudacher (AFS). We explain the relation between the resulting 'non-relativistic' non-local action and the second-derivative string sigma model. We comment on modifications introduced by strong-coupling corrections to the AFS phase. We mostly discuss the SU(2) sector but also present generalizations to the SL(2) and SU(1|1) sectors, confirming universality of the dressing phase contribution by matching the low-energy limit of the AFS-type spin-chain S-matrix with tree-level string-theory S-matrix

Aspects of warped AdS3/CFT2 correspondence

Science.gov (United States)

Chen, Bin; Zhang, Jia-Ju; Zhang, Jian-Dong; Zhong, De-Liang

2013-04-01

In this paper we apply the thermodynamics method to investigate the holographic pictures for the BTZ black hole, the spacelike and the null warped black holes in three-dimensional topologically massive gravity (TMG) and new massive gravity (NMG). Even though there are higher derivative terms in these theories, the thermodynamics method is still effective. It gives consistent results with the ones obtained by using asymptotical symmetry group (ASG) analysis. In doing the ASG analysis we develop a brute-force realization of the Barnich-Brandt-Compere formalism with Mathematica code, which also allows us to calculate the masses and the angular momenta of the black holes. In particular, we propose the warped AdS3/CFT2 correspondence in the new massive gravity, which states that quantum gravity in the warped spacetime could holographically dual to a two-dimensional CFT with {c_R}={c_L}=24 /{Gm{β^2√{{2( {21-4{β^2}} )}}}}.

Independent assessment of matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) sample preparation quality : Effect of sample preparation on MALDI-MS of synthetic polymers

NARCIS (Netherlands)

Kooijman, Pieter C.; Kok, Sander; Honing, Maarten

2017-01-01

Rationale: Matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) provides detailed and in-depth information about the molecular characteristics of synthetic polymers. To obtain the most accurate results the sample preparation parameters should be chosen to suit the sample and the

Rank-Optimized Logistic Matrix Regression toward Improved Matrix Data Classification.

Science.gov (United States)

Zhang, Jianguang; Jiang, Jianmin

2018-02-01

While existing logistic regression suffers from overfitting and often fails in considering structural information, we propose a novel matrix-based logistic regression to overcome the weakness. In the proposed method, 2D matrices are directly used to learn two groups of parameter vectors along each dimension without vectorization, which allows the proposed method to fully exploit the underlying structural information embedded inside the 2D matrices. Further, we add a joint [Formula: see text]-norm on two parameter matrices, which are organized by aligning each group of parameter vectors in columns. This added co-regularization term has two roles-enhancing the effect of regularization and optimizing the rank during the learning process. With our proposed fast iterative solution, we carried out extensive experiments. The results show that in comparison to both the traditional tensor-based methods and the vector-based regression methods, our proposed solution achieves better performance for matrix data classifications.

Use of matrix-assisted laser desorption ionization-time of flight mass spectrometry for caspofungin susceptibility testing of Candida and Aspergillus species.

Science.gov (United States)

De Carolis, Elena; Vella, Antonietta; Florio, Ada R; Posteraro, Patrizia; Perlin, David S; Sanguinetti, Maurizio; Posteraro, Brunella

2012-07-01

Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) was evaluated for testing susceptibility to caspofungin of wild-type and fks mutant isolates of Candida and Aspergillus. Complete essential agreement was observed with the CLSI reference method, with categorical agreement for 94.1% of the Candida isolates tested. Thus, MALDI-TOF MS is a reliable and accurate method to detect fungal isolates with reduced caspofungin susceptibility.

Fibroblast-Derived Extracellular Matrix Induces Chondrogenic Differentiation in Human Adipose-Derived Mesenchymal Stromal/Stem Cells in Vitro

Directory of Open Access Journals (Sweden)

Kevin Dzobo

2016-08-01

Full Text Available Mesenchymal stromal/stem cells (MSCs represent an area being intensively researched for tissue engineering and regenerative medicine applications. MSCs may provide the opportunity to treat diseases and injuries that currently have limited therapeutic options, as well as enhance present strategies for tissue repair. The cellular environment has a significant role in cellular development and differentiation through cell–matrix interactions. The aim of this study was to investigate the behavior of adipose-derived MSCs (ad-MSCs in the context of a cell-derived matrix so as to model the in vivo physiological microenvironment. The fibroblast-derived extracellular matrix (fd-ECM did not affect ad-MSC morphology, but reduced ad-MSC proliferation. Ad-MSCs cultured on fd-ECM displayed decreased expression of integrins α2 and β1 and subsequently lost their multipotency over time, as shown by the decrease in CD44, Octamer-binding transcription factor 4 (OCT4, SOX2, and NANOG gene expression. The fd-ECM induced chondrogenic differentiation in ad-MSCs compared to control ad-MSCs. Loss of function studies, through the use of siRNA and a mutant Notch1 construct, revealed that ECM-mediated ad-MSCs chondrogenesis requires Notch1 and β-catenin signaling. The fd-ECM also showed anti-senescence effects on ad-MSCs. The fd-ECM is a promising approach for inducing chondrogenesis in ad-MSCs and chondrogenic differentiated ad-MSCs could be used in stem cell therapy procedures.

Rapid Differentiation of Haemophilus influenzae and Haemophilus haemolyticus by Use of Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry with ClinProTools Mass Spectrum Analysis.

Science.gov (United States)

Chen, Jonathan H K; Cheng, Vincent C C; Wong, Chun-Pong; Wong, Sally C Y; Yam, Wing-Cheong; Yuen, Kwok-Yung

2017-09-01

Haemophilus influenzae is associated with severe invasive disease, while Haemophilus haemolyticus is considered part of the commensal flora in the human respiratory tract. Although the addition of a custom mass spectrum library into the matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) system could improve identification of these two species, the establishment of such a custom database is technically complicated and requires a large amount of resources, which most clinical laboratories cannot afford. In this study, we developed a mass spectrum analysis model with 7 mass peak biomarkers for the identification of H. influenzae and H. haemolyticus using the ClinProTools software. We evaluated the diagnostic performance of this model using 408 H. influenzae and H. haemolyticus isolates from clinical respiratory specimens from 363 hospitalized patients and compared the identification results with those obtained with the Bruker IVD MALDI Biotyper. The IVD MALDI Biotyper identified only 86.9% of H. influenzae (311/358) and 98.0% of H. haemolyticus (49/50) clinical isolates to the species level. In comparison, the ClinProTools mass spectrum model could identify 100% of H. influenzae (358/358) and H. haemolyticus (50/50) clinical strains to the species level and significantly improved the species identification rate (McNemar's test, P mass spectrometry to handle closely related bacterial species when the proprietary spectrum library failed. This approach should be useful for the differentiation of other closely related bacterial species. Copyright © 2017 American Society for Microbiology.

Quasinormal-Mode Expansion of the Scattering Matrix

Directory of Open Access Journals (Sweden)

Filippo Alpeggiani

2017-06-01

Full Text Available It is well known that the quasinormal modes (or resonant states of photonic structures can be associated with the poles of the scattering matrix of the system in the complex-frequency plane. In this work, the inverse problem, i.e., the reconstruction of the scattering matrix from the knowledge of the quasinormal modes, is addressed. We develop a general and scalable quasinormal-mode expansion of the scattering matrix, requiring only the complex eigenfrequencies and the far-field properties of the eigenmodes. The theory is validated by applying it to illustrative nanophotonic systems with multiple overlapping electromagnetic modes. The examples demonstrate that our theory provides an accurate first-principles prediction of the scattering properties, without the need for postulating ad hoc nonresonant channels.

Fermion masses from dimensional reduction

International Nuclear Information System (INIS)

Kapetanakis, D.; Zoupanos, G.

1990-01-01

We consider the fermion masses in gauge theories obtained from ten dimensions through dimensional reduction on coset spaces. We calculate the general fermion mass matrix and we apply the mass formula in illustrative examples. (orig.)

Fermion masses from dimensional reduction

Energy Technology Data Exchange (ETDEWEB)

Kapetanakis, D. (National Research Centre for the Physical Sciences Democritos, Athens (Greece)); Zoupanos, G. (European Organization for Nuclear Research, Geneva (Switzerland))

1990-10-11

We consider the fermion masses in gauge theories obtained from ten dimensions through dimensional reduction on coset spaces. We calculate the general fermion mass matrix and we apply the mass formula in illustrative examples. (orig.).

The Effect of Collimating Lens Focusing on Laser Beam Shape in Matrix Assisted Laser Desorption/Ionization Mass Spectrometry (MALDI-MS).

Science.gov (United States)

O'Rourke, Matthew B; Raymond, Benjamin B A; Djordjevic, Steven P; Padula, Matthew P

2018-03-01

Tissue imaging using matrix assisted laser desorption/ionization mass spectrometry (MALDI-MS) is a well-established technique that, in recent years, has seen wider adoption and novel application. Applications such imaging mass spectrometry (IMS) and biotyping are beginning to gain greater exposure and use; however, with limitations in optimization methods, producing the best result often relies on the ability to customize the physical characteristics of the instrumentation, a task that is challenging for most mass spectrometry laboratories. With this in mind, we have described the effect of making simple adjustments to the laser optics at the final collimating lens area, to adjust the laser beam size and shape in order to allow greater customization of the instrument for improving techniques such as IMS. We have therefore been able to demonstrate that improvements can be made without requiring the help of an electrical engineer or external funding in a way that only costs a small amount of time. Graphical Abstract ᅟ.

Rapid identification of bacteria in positive blood culture broths by matrix-assisted laser desorption ionization-time of flight mass spectrometry.

Science.gov (United States)

Stevenson, Lindsay G; Drake, Steven K; Murray, Patrick R

2010-02-01

Matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry is a rapid, accurate method for identifying bacteria and fungi recovered on agar culture media. We report herein a method for the direct identification of bacteria in positive blood culture broths by MALDI-TOF mass spectrometry. A total of 212 positive cultures were examined, representing 32 genera and 60 species or groups. The identification of bacterial isolates by MALDI-TOF mass spectrometry was compared with biochemical testing, and discrepancies were resolved by gene sequencing. No identification (spectral score of blood culture broth. Of the bacteria with a spectral score of > or = 1.7, 162 (95.3%) of 170 isolates were correctly identified. All 8 isolates of Streptococcus mitis were misidentified as being Streptococcus pneumoniae isolates. This method provides a rapid, accurate, definitive identification of bacteria within 1 h of detection in positive blood cultures with the caveat that the identification of S. pneumoniae would have to be confirmed by an alternative test.

Parametrization relating the fermionic mass spectra

International Nuclear Information System (INIS)

Kleppe, A.

1993-01-01

When parametrizing the fermionic mass spectra in terms of the unit matrix and a recursive matrix scrR 0 , which corresponds to an underlying scaling pattern in the mass spectra, each fermionic sector is characterized by three parameters: k, α, and R. Using the set of relations displayed by the parameters of the different sectors, it is possible to formulate a ''family Lagrangian'' which for each sector encompasses all the families. Relations between quark masses are furthermore deduced from these ''family Lagrangians.'' Using the relations between the parameters of the different charge sectors, it is also possible to ''derive'' the quark mass spectra from the (charged) leptonic mass spectrum

Species Identification and Delineation of Pathogenic Mucorales by Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry.

Science.gov (United States)

Shao, Jin; Wan, Zhe; Li, Ruoyu; Yu, Jin

2018-04-01

This study aimed to validate the effectiveness of matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS)-based identification of filamentous fungi of the order Mucorales. A total of 111 isolates covering six genera preserved at the Research Center for Medical Mycology of Peking University were selected for MALDI-TOF MS analysis. We emphasized the study of 23 strains of Mucor irregularis predominantly isolated from patients in China. We first used the Bruker Filamentous Fungi library (v1.0) to identify all 111 isolates. To increase the identification rate, we created a compensatory in-house database, the Beijing Medical University (BMU) database, using 13 reference strains covering 6 species, including M. irregularis , Mucor hiemalis , Mucor racemosus , Cunninghamella bertholletiae , Cunninghamella phaeospora , and Cunninghamella echinulata All 111 isolates were then identified by MALDI-TOF MS using a combination of the Bruker library and BMU database. MALDI-TOF MS identified 55 (49.5%) and 74 (66.7%) isolates at the species and genus levels, respectively, using the Bruker Filamentous Fungi library v1.0 alone. A combination of the Bruker library and BMU database allowed MALDI-TOF MS to identify 90 (81.1%) and 111 (100%) isolates at the species and genus levels, respectively, with a significantly increased accuracy rate. MALDI-TOF MS poorly identified Mucorales when the Bruker library was used alone due to its lack of some fungal species. In contrast, this technique perfectly identified M. irregularis after main spectrum profiles (MSPs) of relevant reference strains were added to the Bruker library. With an expanded Bruker library, MALDI-TOF MS is an effective tool for the identification of pathogenic Mucorales. Copyright © 2018 American Society for Microbiology.

Variability of matrix effects in liquid and gas chromatography - mass spectrometry analysis of pesticide residues after QuEChERS sample preparation of different food crops

Science.gov (United States)

Gas and liquid chromatography (GC and LC) coupled to sophisticated mass spectrometry (MS) instruments are among the most powerful analytical tools currently available to monitor pesticide residues in food, among other applications. However, both GC-MS and LC-MS are susceptible to matrix effects whi...

K-matrix analysis of the (IJ sup P sup C = 00 sup + sup +)-wave in the mass region below 1900 MeV

CERN Document Server

Anisovich, V V

2003-01-01

We present the results of the current analysis of the partial wave IJ sup P sup C =00 sup + sup + based on the available data for meson spectra (pi pi, K anti K, eta eta, eta eta sup ' ,pi pi pi pi). In the framework of the K-matrix approach, the analytical amplitude has been reconstructed in the mass region 280 MeVmasses and total widths of the resonances) are determined as well as pole residues (partial widths to meson channels pi pi, anti KK,eta eta,eta eta sup ' ,pi pi pi pi). The fitted amplitude gives us the positions of the K-matrix poles (bare states) and the values of bare-state couplings to meson channels thus allowing the quark-antiquark nonet classification of bare states. On the basis of the obtained partial widths to the channels pi pi, anti KK,eta e...

A column switching ultrahigh-performance liquid chromatography-tandem mass spectrometry method to determine anandamide and 2-arachidonoylglycerol in plasma samples.

Science.gov (United States)

Marchioni, Camila; de Souza, Israel Donizeti; Grecco, Caroline Fernandes; Crippa, José Alexandre; Tumas, Vitor; Queiroz, Maria Eugênia Costa

2017-05-01

This study reports a fast, sensitive, and selective column switching ultrahigh-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method to determine the endocannabinoids (eCBs), anandamide (AEA), and 2-arachidonoylglycerol (2-AG) in plasma samples. This bidimensional system used a restricted access media column (RP-8 ADS, 25 mm × 4 mm × 25 μM) in the first dimension and a core-shell Kinetex C18 (100 mm × 2, 1.7 mm × 1 μM) column in the second dimension, followed by detection in a mass spectrometer triple quadrupole (multiple reactions monitoring mode) operating in the positive mode. RP-8 ADS was used for trace enrichment of eCBs (reverse phase partitioning) and macromolecular matrix size exclusion; the core-shell column was used for the chromatographic separation. The column switching UHPLC-MS/MS method presented a linear range spanning from 0.1 ng mL -1 (LOQ) to 6 ng mL -1 for AEA and from 0.04 ng mL -1 (LOQ) to 10 ng mL -1 for 2-AG. Excluding the LLOQ values, the precision assays provided coefficients of variation lower than 8% and accuracy with relative standard error values lower than 14%. Neither carryover nor matrix effects were detected. This high-throughput column switching method compared to conventional methods is time saving as it involves fewer steps, consumes less solvent, and presents lower LLOQ. The column switching UHPLC-MS/MS method was successfully applied to determine AEA and 2-AG in plasma samples obtained from Alzheimer's disease patients. Graphical abstract A column switching ultra high-performance liquid chromatography-tandem mass spectrometry method using RP-8 ADS column and core shell column to determine endocannabinoids in plasma samples.

Semiconductor Nanomaterials-Based Fluorescence Spectroscopic and Matrix-Assisted Laser Desorption/Ionization (MALDI Mass Spectrometric Approaches to Proteome Analysis

Directory of Open Access Journals (Sweden)

Suresh Kumar Kailasa

2013-12-01

Full Text Available Semiconductor quantum dots (QDs or nanoparticles (NPs exhibit very unusual physico-chemcial and optical properties. This review article introduces the applications of semiconductor nanomaterials (NMs in fluorescence spectroscopy and matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS for biomolecule analysis. Due to their unique physico-chemical and optical properties, semiconductors NMs have created many new platforms for investigating biomolecular structures and information in modern biology. These semiconductor NMs served as effective fluorescent probes for sensing proteins and cells and acted as affinity or concentrating probes for enriching peptides, proteins and bacteria proteins prior to MALDI-MS analysis.

Adding Insult to Imagery? Art Education and Censorship

Science.gov (United States)

Sweeny, Robert W.

2007-01-01

The "Adding Insult to Imagery? Artistic Responses to Censorship and Mass-Media" exhibition opened in January 16, 2006, Kipp Gallery on the Indiana University of Pennsylvania campus. Eleven gallery-based works, 9 videos, and 10 web-based artworks comprised the show; each dealt with the relationship between censorship and mass mediated…

Independent assessment of matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) sample preparation quality: A novel statistical approach for quality scoring.

Science.gov (United States)

Kooijman, Pieter C; Kok, Sander J; Weusten, Jos J A M; Honing, Maarten

2016-05-05

Preparation of samples according to an optimized method is crucial for accurate determination of polymer sample characteristics by Matrix-Assisted Laser Desorption Ionization (MALDI) analysis. Sample preparation conditions such as matrix choice, cationization agent, deposition technique or even the deposition volume should be chosen to suit the sample of interest. Many sample preparation protocols have been developed and employed, yet finding the optimal sample preparation protocol remains a challenge. Because an objective comparison between the results of diverse protocols is not possible, "gut-feeling" or "good enough" is often decisive in the search for an optimum. This implies that sub-optimal protocols are used, leading to a loss of mass spectral information quality. To address this problem a novel analytical strategy based on MALDI imaging and statistical data processing was developed in which eight parameters were formulated to objectively quantify the quality of sample deposition and optimal MALDI matrix composition and finally sum up to an overall quality score of the sample deposition. These parameters can be established in a fully automated way using commercially available mass spectrometry imaging instruments without any hardware adjustments. With the newly developed analytical strategy the highest quality MALDI spots were selected, resulting in more reproducible and more valuable spectra for PEG in a variety of matrices. Moreover, our method enables an objective comparison of sample preparation protocols for any analyte and opens up new fields of investigation by presenting MALDI performance data in a clear and concise way. Copyright © 2016 Elsevier B.V. All rights reserved.

Long-term behavior of stellar flare activity in AD Leo

International Nuclear Information System (INIS)

Pettersen, B.R.

1984-01-01

AD Leo is a dM4e solar neighborhood red dwarf on the main sequence. It has an effective temperature of 3500 0 K, radius of 0.44 R/sub solar/ and a bolomeric luminosity of 0.024 L/sub solar/. The mass-luminosity relation implies a mass of 0.44 M/sub solar/. Photometry of starspots indicates a rotation period of 2.7 days implying that the rotation axis of AD Leo is inclined 38 0 to the line of sight

Center of mass detection via an active pixel sensor

Science.gov (United States)

Yadid-Pecht, Orly (Inventor); Minch, Brad (Inventor); Pain, Bedabrara (Inventor); Fossum, Eric (Inventor)

2006-01-01

An imaging system for identifying the location of the center of mass (COM) in an image. In one aspect, an imaging system includes a plurality of photosensitive elements arranged in a matrix. A center of mass circuit coupled to the photosensitive elements includes a resistive network and a normalization circuit including at least one bipolar transistor. The center of mass circuit identifies a center of mass location in the matrix and includes: a row circuit, where the row circuit identifies a center of mass row value in each row of the matrix and identifies a row intensity for each row; a horizontal circuit, where the horizontal circuit identifies a center of mass horizontal value; and a vertical circuit, where the vertical circuit identifies a center of mass vertical value. The horizontal and vertical center of mass values indicate the coordinates of the center of mass location for the image.

Particle collisions near a three-dimensional warped AdS black hole

Science.gov (United States)

Bécar, Ramón; González, P. A.; Vásquez, Yerko

2018-04-01

In this paper we consider the warped AdS3 black hole solution of topologically massive gravity with a negative cosmological constant, and we study the possibility that it acts as a particle accelerator by analyzing the energy in the center of mass (CM) frame of two colliding particles in the vicinity of its horizon, which is known as the Bañnados, Silk and West (BSW) process. Mainly, we show that the critical angular momentum (L_c) of the particle decreases when the warping parameter(ν ) increases. Also, we show that despite the particle with L_c being able to exist for certain values of the conserved energy outside the horizon, it will never reach the event horizon; therefore, the black hole cannot act as a particle accelerator with arbitrarily high CM energy on the event horizon. However, such a particle could also exist inside the outer horizon, with the BSW process being possible on the inner horizon. On the other hand, for the extremal warped AdS3 black hole, the particle with L_c and energy E could exist outside the event horizon and, the CM energy blows up on the event horizon if its conserved energy fulfills the condition E2>(ν 2+3)l2/3(ν ^{2-1)}, with the BSW process being possible.

Evaluation and prevention of the negative matrix effect of terpenoids on pesticides in apples quantification by gas chromatography-tandem mass spectrometry.

Science.gov (United States)

Giacinti, Géraldine; Raynaud, Christine; Capblancq, Sophie; Simon, Valérie

2017-02-03

The sample matrix can enhance the gas chromatography signal of pesticide residues relative to that obtained with the same concentration of pesticide in solvent. This paper is related to negative matrix effects observed in coupled gas chromatography-mass spectrometry ion trap (GC/MS 2 ) quantification of pesticides in concentrated extracts of apple peel prepared by the Quick Easy Cheap Effective Rugged and Safe (QuEChERS) method. It is focused on the pesticides most frequently used on the apple varieties studied, throughout the crop cycle, right up to harvest, to combat pests and diseases and to improve fruit storage properties. Extracts from the fleshy receptacle (flesh), the epiderm (peel) and fruit of three apple varieties were studied by high-performance thin-layer chromatography hyphenated with UV-vis light detection (HPTLC/UV visible). The peel extracts had high concentrations of triterpenic acids (oleanolic and ursolic acids), reaching 25mgkg -1 , whereas these compounds were not detected in the flesh extracts (<0.05mgkg -1 ). A significant relationship has been found between the levels of these molecules and negative matrix effects in GC/MS 2 . The differences in the behavior of pesticides with respect to matrix effects can be accounted for by the physicochemical characteristics of the molecules (lone pairs, labile hydrogen, conjugation). The HPTLC/UV visible method developed here for the characterization of QuEChERS extracts acts as a complementary clean-up method, aimed to decrease the negative matrix effects of such extracts. Copyright © 2016 Elsevier B.V. All rights reserved.

On stringy AdS5 x S5 and higher spin holography

International Nuclear Information System (INIS)

Bianchi, Massimo; Morales, Jose F.; Samtleben, Henning

2003-01-01

We derive the spectrum of Kaluza-Klein descendants of string excitations on AdS 5 x S 5 . String states are organized in long multiplets of the AdS supergroup SU(2,2|4,R) with a rich pattern of shortenings at the higher spin enhancement point λ=0. The string states holographically dual to the higher spin currents of SYM theory in the strict zero coupling limit are identified together with the corresponding Goldstone particles responsible for the Higgsing of the higher spin symmetry at λ≠ 0. Exploiting higher spin symmetry we propose a very simple yet effective mass formula and establish a one-to-one correspondence between the complete spectrum of Δ 0 ≤ 4 string states and relevant/marginal single-trace deformations in N = 4 SYM theory at large N. To this end, we describe how to efficiently enumerate scaling operators in 'free' YM theory, with the inclusion of fermionic 'letters', by resorting to Polya theory. Comparison between the spectra of 1/4-BPS states is also presented. Finally, we discuss how to organize the spectrum of N = 4 SYM theory in SU(2,2|4,R) supermultiplets by means of some kind of 'Eratostenes's sieve'. (author)

Deviations of the lepton mapping matrix form the harrison-perkins-scott form

International Nuclear Information System (INIS)

Friedberg, R.; Lee, T.D.

2010-01-01

We propose a simple set of hypotheses governing the deviations of the leptonic mapping matrix from the Harrison-Perkins-Scott (HPS) form. These deviations are supposed to arise entirely from a perturbation of the mass matrix in the charged lepton sector. The perturbing matrix is assumed to be purely imaginary (thus maximally T-violating) and to have a strength in energy scale no greater (but perhaps smaller) than the muon mass. As we shall show,it then follows that the absolute value of the mapping matrix elements pertaining to the tau lepton deviate by no more than O((m μ /m τ ) 2 ) ≅ 3.5 x 10 -3 from their HPS values. Assuming that(m μ /m τ ) 2 can be neglected, we derive two simple constraints on the four parameters θ12, θ23, θ31, and δ of the mapping matrix. These constraints are independent of the details of the imaginary T-violating perturbation of the charged lepton mass matrix. We also show that the e and μ parts of the mapping matrix have a definite form governed by two parameters α and β; any deviation of order m μ /m τ can be accommodated by adjusting these two parameters. (authors)

Entanglement Entropy of AdS Black Holes

Directory of Open Access Journals (Sweden)

Maurizio Melis

2010-11-01

Full Text Available We review recent progress in understanding the entanglement entropy of gravitational configurations for anti-de Sitter gravity in two and three spacetime dimensions using the AdS/CFT correspondence. We derive simple expressions for the entanglement entropy of two- and three-dimensional black holes. In both cases, the leading term of the entanglement entropy in the large black hole mass expansion reproduces exactly the Bekenstein-Hawking entropy, whereas the subleading term behaves logarithmically. In particular, for the BTZ black hole the leading term of the entanglement entropy can be obtained from the large temperature expansion of the partition function of a broad class of 2D CFTs on the torus.

Planar plane-wave matrix theory at the four loop order: integrability without BMN scaling

International Nuclear Information System (INIS)

Fischbacher, Thomas; Klose, Thomas; Plefka, Jan

2005-01-01

We study SU(N) plane-wave matrix theory up to fourth perturbative order in its large N planar limit. The effective hamiltonian in the closed su(2) subsector of the model is explicitly computed through a specially tailored computer program to perform large scale distributed symbolic algebra and generation of planar graphs. The number of graphs here was in the deep billions. The outcome of our computation establishes the four-loop integrability of the planar plane-wave matrix model. To elucidate the integrable structure we apply the recent technology of the perturbative asymptotic Bethe ansatz to our model. The resulting S-matrix turns out to be structurally similar but nevertheless distinct to the so far considered long-range spin-chain S-matrices of Inozemtsev, Beisert-Dippel-Staudacher and Arutyunov-Frolov-Staudacher in the AdS/CFT context. In particular our result displays a breakdown of BMN scaling at the four-loop order. That is, while there exists an appropriate identification of the matrix theory mass parameter with the coupling constant of the N=4 superconformal Yang-Mills theory which yields an eighth order lattice derivative for well separated impurities (naively implying BMN scaling) the detailed impurity contact interactions ruin this scaling property at the four-loop order. Moreover we study the issue of 'wrapping' interactions, which show up for the first time at this loop-order through a Konishi descendant length four operator. (author)

Mass, angular momentum and thermodynamics in four-dimensional Kerr-AdS black holes

Energy Technology Data Exchange (ETDEWEB)

Olea, Rodrigo [Departamento de Fisica, Pontificia Universidad Catolica de Chile, Casilla 306, Santiago 22 (Chile)

2005-06-01

In this paper, the connection between the Lorentz-covariant counterterms that regularize the four-dimensional AdS gravity action and topological invariants is explored. It is shown that demanding the spacetime to have a negative constant curvature in the asymptotic region permits the explicit construction of such series of boundary terms. The orthonormal frame is adapted to appropriately describe the boundary geometry and, as a result, the boundary term can be expressed as a functional of the boundary metric, extrinsic curvature and intrinsic curvature. This choice also allows to write down the background-independent Noether charges associated to asymptotic symmetries in standard tensorial formalism. The absence of the Gibbons-Hawking term is a consequence of an action principle based on a boundary condition different than Dirichlet on the metric. This argument makes plausible the idea of regarding this approach as an alternative regularization scheme for AdS gravity in all even dimensions, different than the standard counterterms prescription. As an illustration of the finiteness of the charges and the euclidean action in this framework, the conserved quantities and black hole entropy for four-dimensional Kerr-AdS are computed.

Use of Matrix-Assisted Laser Desorption Ionization–Time of Flight Mass Spectrometry for Caspofungin Susceptibility Testing of Candida and Aspergillus Species

Science.gov (United States)

De Carolis, Elena; Vella, Antonietta; Florio, Ada R.; Posteraro, Patrizia; Perlin, David S.; Posteraro, Brunella

2012-01-01

Matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS) was evaluated for testing susceptibility to caspofungin of wild-type and fks mutant isolates of Candida and Aspergillus. Complete essential agreement was observed with the CLSI reference method, with categorical agreement for 94.1% of the Candida isolates tested. Thus, MALDI-TOF MS is a reliable and accurate method to detect fungal isolates with reduced caspofungin susceptibility. PMID:22535984

Spontaneous mirror left-right symmetry breaking for leptogenesis parametrized by Majorana neutrino mass matrix

Science.gov (United States)

Gu, Pei-Hong

2017-10-01

We introduce a mirror copy of the ordinary fermions and Higgs scalars for embedding the SU(2) L × U(1) Y electroweak gauge symmetry into an SU(2) L × SU(2) R × U(1) B-L left-right gauge symmetry. We then show the spontaneous left-right symmetry breaking can automatically break the parity symmetry motivated by solving the strong CP problem. Through the SU(2) R gauge interactions, a mirror Majorana neutrino can decay into a mirror charged lepton and two mirror quarks. Consequently we can obtain a lepton asymmetry stored in the mirror charged leptons. The Yukawa couplings of the mirror and ordinary charged fermions to a dark matter scalar then can transfer the mirror lepton asymmetry to an ordinary lepton asymmetry which provides a solution to the cosmic baryon asymmetry in association with the SU(2) L sphaleron processes. In this scenario, the baryon asymmetry can be well described by the neutrino mass matrix up to an overall factor.

Top quark mass measurement in the electron-muon channel with the matrix element method applied to the 8 TeV data of the ATLAS experiment at LHC

International Nuclear Information System (INIS)

Pires, S.

2015-01-01

The work presented in this thesis lies within the scope of the measurement of the top quark mass in the decay channel electron-muon. This experimental measurement is achieved by the use of the matrix element method with collisions produced at LHC at a centre of mass energy of 8 TeV and collected by the ATLAS detector in 2012. After introducing the theoretical context of the Standard Model and the physics of the top quark, a detailed description of the ATLAS detector design and of both the event simulation and reconstruction is given. The first analysis presented was done during the beginning of the thesis and focuses on the impact of the insertion of an innermost new pixel layer in the ATLAS detector on the b-tagging performance during the data taking starting in 2015 with a centre of mass energy of 13 TeV. The second part of the thesis is dedicated to the top quark mass measurement. After reviewing the selection procedure to which the analysis is linked, the calibration of the matrix element method is presented. The top quark mass is measured as : m(top) = [172.40 ± 0.35 (stat.) ± 1.12 (syst.)] GeV. This measurement is obtained with a precision of 0.64% and is compatible with both the World combination of the top quark mass and with recent measurements published by the ATLAS collaboration. (author)

Mass Formulae for Broken Supersymmetry in Curved Space-Time

CERN Document Server

Ferrara, Sergio

2016-01-01

We derive the mass formulae for ${\\cal N}=1$, $D=4$ matter-coupled Supergravity for broken (and unbroken) Supersymmetry in curved space-time. These formulae are applicable to de Sitter configurations as is the case for inflation. For unbroken Supersymmetry in anti-de Sitter (AdS) one gets the mass relations modified by the AdS curvature. We compute the mass relations both for the potential and its derivative non-vanishing.

[Application of precursor ion scanning method in rapid screening of illegally added phosphodiesterase-5 inhibitors and their unknown derivatives in Chinese traditional patent medicines and health foods].

Science.gov (United States)

Sun, Jing; Cao, Ling; Feng, Youlong; Tan, Li

2014-11-01

The compounds with similar structure often have similar pharmacological activities. So it is a trend for illegal addition that new derivatives of effective drugs are synthesized to avoid the statutory test. This bring challenges to crack down on illegal addition behavior, however, modified derivatives usually have similar product ions, which allow for precursor ion scanning. In this work, precursor ion scanning mode of a triple quadrupole mass spectrometer was first applied to screen illegally added drugs in complex matrix such as Chinese traditional patent medicines and healthy foods. Phosphodiesterase-5 inhibitors were used as experimental examples. Through the analysis of the structure and mass spectrum characteristics of the compounds, phosphodiesterase-5 inhibitors were classified, and their common product ions were screened by full scan of product ions of typical compounds. Then high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method with precursor ion scanning mode was established based on the optimization of MS parameters. The effect of mass parameters and the choice of fragment ions were also studied. The method was applied to determine actual samples and further refined. The results demonstrated that this method can meet the need of rapid screening of unknown derivatives of phosphodiesterase-5 inhibitors in complex matrix, and prevent unknown derivatives undetected. This method shows advantages in sensitivity, specificity and efficiency, and is worth to be further investigated.

The effects of flavour symmetry breaking on hadron matrix elements

International Nuclear Information System (INIS)

Cooke, A.N.; Horsley, R.; Pleiter, D.; Zanotti, J.M.

2012-12-01

By considering a flavour expansion about the SU(3)-flavour symmetric point, we investigate how flavour-blindness constrains octet baryon matrix elements after SU(3) is broken by the mass difference between the strange and light quarks. We find the expansions to be highly constrained along a mass trajectory where the singlet quark mass is held constant, which proves beneficial for extrapolations of 2+1 flavour lattice data to the physical point. We investigate these effects numerically via a lattice calculation of the flavour-conserving and flavour-changing matrix elements of the vector and axial operators between octet baryon states.

The effects of flavour symmetry breaking on hadron matrix elements

Energy Technology Data Exchange (ETDEWEB)

Cooke, A.N.; Horsley, R. [Edinburgh Univ. (United Kingdom). School of Physics and Astronomy; Nakamura, Y. [RIKEN Advanced Institute for Computational Science, Kobe (Japan); Pleiter, D. [Juelich Research Centre (Germany); Regensburg Univ. (Germany). Institut fuer Theoretische Physik; Rakow, P.E.L. [Liverpool Univ. (United Kingdom). Theoretical Physics Division; Schierholz, G. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Zanotti, J.M. [Adelaide Univ. (Australia). School of Chemistry and Physics

2012-12-15

By considering a flavour expansion about the SU(3)-flavour symmetric point, we investigate how flavour-blindness constrains octet baryon matrix elements after SU(3) is broken by the mass difference between the strange and light quarks. We find the expansions to be highly constrained along a mass trajectory where the singlet quark mass is held constant, which proves beneficial for extrapolations of 2+1 flavour lattice data to the physical point. We investigate these effects numerically via a lattice calculation of the flavour-conserving and flavour-changing matrix elements of the vector and axial operators between octet baryon states.

The effect of alumina nanofillers size and shape on mechanical behavior of PMMA matrix composite

Directory of Open Access Journals (Sweden)

Ben Hasan Somaya Ahmed

2014-01-01

Full Text Available Composites with the addition of alumina nanofillers show improvement in mechanical properties. The PMMA polymer was used as a matrix and two different types of nanofillers, having extremely different shapes were added in the matrix to form the composite. Reinforcements were based on alumina nanoparticles having either spherical shape or whiskers having the length to diameter ratio of 100. The influence of alumina fillers size, shape and fillers loading on mechanical properties of prepared composite were studied using the nanoindentation measurements and dynamic mechanical analysis. It was observed that both alumina whiskers and alumina spherical nanoparticles added in the PMMA matrix improved the mechanical properties of the composite but the improvement was significantly higher with alumina whisker reinforcement. The concentration of the reinforcing alumina spherical nanoparticles and alumina whiskers in PMMA matrix varied up to 5 wt. %. The best performance was obtained by the addition of 3 wt. % of alumina whiskers in the PMMA matrix with regard to mechanical properties of the obtained composite.

Origin of CP-violation through quark mass matrix

International Nuclear Information System (INIS)

Kang, K.

1990-01-01

After a brief review of the CP violation models, we trace the origin of CP-phases from the phases of a class of quark mass matrices compatible with the calculability condition. The case of three generations corresponding to the standard milliweak CP model is discussed explicitly for the generic case of Fritzsch-type mass matrices. (orig.)

Supergravity one-loop corrections on AdS7 and AdS3, higher spins and AdS/CFT

Directory of Open Access Journals (Sweden)

Matteo Beccaria

2015-03-01

Full Text Available As was shown earlier, the one-loop correction in 10d supergravity on AdS5×S5 corresponds to the contributions to the vacuum energy and 4d boundary conformal anomaly which are minus the values for one N=4 Maxwell supermultiplet, thus reproducing the subleading term in the N2−1 coefficient in the dual SU(N SYM theory. We perform similar one-loop computations in 11d supergravity on AdS7×S4 and 10d supergravity on AdS3×S3×T4. In the AdS7 case we find that the corrections to the 6d conformal anomaly a-coefficient and the vacuum energy are again minus the ones for one (2,0 tensor multiplet, suggesting that the total a-anomaly coefficient for the dual (2,0 theory is 4N3−9/4N−7/4 and thus vanishes for N=1. In the AdS3 case the one-loop correction to the vacuum energy or 2d central charge turns out to be equal to that of one free (4,4 scalar multiplet, i.e. is c=+6. This reproduces the subleading term in the central charge c=6(Q1Q5+1 of the dual 2d CFT describing decoupling limit of D5–D1 system. We also present the expressions for the 6d a-anomaly coefficient and vacuum energy contributions of general-symmetry higher spin field in AdS7 and consider their application to tests of vectorial AdS/CFT with the boundary conformal 6d theory represented by free scalars, spinors or rank-2 antisymmetric tensors.

Elimination of acoustical phonons by mass deformation

International Nuclear Information System (INIS)

Djajic, R.P.; Setrajcic, J.P.; Tosic, B.S.; Mirjanic, D.L.

1987-01-01

Cubic structure with well expressed anisotropy along one direction was analyzed. Lattice constant along z - direction is few times bigger than the planar lattice constants. If we sputter into such structure and introduce foreign atoms, it is energetically most convenient if they locate themselves along the z - axis. Basic assumption of this model is that clusters form on the boundary layers of the matrix, and that their size decreases with the depth of the structure, and consequently the reduced mass increases width the depth of the structure as well. At the center of the matrix, clusters do not form, and reduced mass is equal to μ m i.e. the mass of the molecule of the matrix

Quantum Black Holes as Holograms in AdS Braneworlds

CERN Document Server

Emparan, R; Kaloper, Nemanja; Emparan, Roberto; Fabbri, Alessandro; Kaloper, Nemanja

2002-01-01

We propose a new approach for using the AdS/CFT correspondence to study quantum black hole physics. The black holes on a brane in an AdS$_{D+1}$ braneworld that solve the classical bulk equations are interpreted as duals of {\\it quantum-corrected} $D$-dimensional black holes, rather than classical ones, of a conformal field theory coupled to gravity. We check this explicitly in D=3 and D=4. In D=3 we reinterpret the existing exact solutions on a flat membrane as states of the dual 2+1 CFT. We show that states with a sufficiently large mass really are 2+1 black holes where the quantum corrections dress the classical conical singularity with a horizon and censor it from the outside. On a negatively curved membrane, we reinterpret the classical bulk solutions as quantum-corrected BTZ black holes. In D=4 we argue that the bulk solution for the brane black hole should include a radiation component in order to describe a quantum-corrected black hole in the 3+1 dual. Hawking radiation of the conformal field is then ...

The Effective Mass of a Ball in the Air

Science.gov (United States)

Messer, J.; Pantaleone, J.

2010-01-01

The air surrounding a projectile affects the projectile's motion in three very different ways: the drag force, the buoyant force, and the added mass. The added mass is an increase in the projectile's inertia from the motion of the air around it. Here we experimentally measure the added mass of a spherical projectile in air. The results agree well…

Analysis of Phospholipid Mixtures from Biological Tissues by Matrix-Assisted Laser Desorption and Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS): A Laboratory Experiment

Science.gov (United States)

Eibisch, Mandy; Fuchs, Beate; Schiller, Jurgen; Sub, Rosmarie; Teuber, Kristin

2011-01-01

Matrix-assisted laser desorption and ionization time-of-flight mass spectrometry (MALDI-TOF MS) is increasingly used to investigate the phospholipid (PL) compositions of tissues and body fluids, often without previous separation of the total mixture into the individual PL classes. Therefore, the questions of whether all PL classes are detectable…

Discrimination of Bacillus anthracis Spores by Direct in-situ Analysis of Matrix-Assisted Laser Desorption/Ionization Time-Of-Flight Mass Spectrometry

International Nuclear Information System (INIS)

Jeong, Youngsu; Lee, Jonghee; Kim, Seongsoo

2013-01-01

The rapid and accurate identification of biological agents is a critical step in the case of bio-terror and biological warfare attacks. Recently, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry has been widely used for the identification of microorganisms. In this study, we describe a method for the rapid and accurate discrimination of Bacillus anthracis spores using MALDI-TOF MS. Our direct in-situ analysis of MALDI-TOF MS does not involve subsequent high-resolution mass analyses and sample preparation steps. This method allowed the detection of species-specific biomarkers from each Bacillus spores. Especially, B. anthracis spores had specific biomarker peaks at 2503, 3089, 3376, 6684, 6698, 6753, and 6840 m/z. Cluster and PCA analyses of the mass spectra of Bacillus spores revealed distinctively separated clusters and within-groups similarity. Therefore, we believe that this method is effective in the real-time identification of biological warfare agents such as B. anthracis as well as other microorganisms in the field

Discrimination of Bacillus anthracis Spores by Direct in-situ Analysis of Matrix-Assisted Laser Desorption/Ionization Time-Of-Flight Mass Spectrometry

Energy Technology Data Exchange (ETDEWEB)

Jeong, Youngsu; Lee, Jonghee; Kim, Seongsoo [Agency for Defense Development, Daejeon (Korea, Republic of)

2013-09-15

The rapid and accurate identification of biological agents is a critical step in the case of bio-terror and biological warfare attacks. Recently, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry has been widely used for the identification of microorganisms. In this study, we describe a method for the rapid and accurate discrimination of Bacillus anthracis spores using MALDI-TOF MS. Our direct in-situ analysis of MALDI-TOF MS does not involve subsequent high-resolution mass analyses and sample preparation steps. This method allowed the detection of species-specific biomarkers from each Bacillus spores. Especially, B. anthracis spores had specific biomarker peaks at 2503, 3089, 3376, 6684, 6698, 6753, and 6840 m/z. Cluster and PCA analyses of the mass spectra of Bacillus spores revealed distinctively separated clusters and within-groups similarity. Therefore, we believe that this method is effective in the real-time identification of biological warfare agents such as B. anthracis as well as other microorganisms in the field.

Preparation of mesoporous zirconia microspheres as inert matrix

Energy Technology Data Exchange (ETDEWEB)

Guo, Ting [State Key Laboratory of New Ceramics and Fine Processing, Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing, 100084 (China); Wang, Chen; Lv, Jinlong [Beijing Key Laboratory of Fine Ceramics, Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing, 100084 (China); Liang, Tongxiang, E-mail: txliang@tsinghua.edu.cn [State Key Laboratory of New Ceramics and Fine Processing, Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing, 100084 (China)

2016-12-01

Mesoporous zirconia microspheres, with a diameter of 900 μm, were prepared as an inert accelerator driven system (ADS) transmutation element matrix by the sol-gel method. The purpose of mesopores is to improve the adsorption capacity of inert matrix fuel (IMF) for minor actinides. The study indicated that the mesoporous zirconia performance was improved after the microspheres were hydrothermally treated at 150 °C, the specific surface area increased from 28.29 m{sup 2}/g to 61.28 m{sup 2}/g, and hydrothermal treatment avoided the cracking of the microspheres. Pre-decomposition of the organics during the hydrothermal process stabilized the mesoporous structure. The average pore diameter of mesoporous microsphere was 14.3 nm. - Highlights: • Mesoporous zirconia microspheres with a diameter of 900 μm were prepared as ADS transmutation element inert matrix. • The mesoporous performance was improved after the microspheres were hydrothermally treated at 150 °C. • The specific surface area increased from 28.29 m{sup 2}/g to 61.28 m{sup 2}/g. • The hydrothermal treatment could avoid the cracking of the microspheres. • The specific surface area of mesoporous microsphere was 61.28 m{sup 2}/g and the average pore diameter was 14.3 nm.

Improvement of non-destructive fissile mass assays in α low-level waste drums: A matrix correction method based on neutron capture gamma-rays and a neutron generator

Science.gov (United States)

Jallu, F.; Loche, F.

2008-08-01

Within the framework of radioactive waste control, non-destructive assay (NDA) methods may be employed. The active neutron interrogation (ANI) method is now well-known and effective in quantifying low α-activity fissile masses (mainly 235U, 239Pu, 241Pu) with low densities, i.e. less than about 0.4, in radioactive waste drums of volumes up to 200 l. The PROMpt Epithermal and THErmal interrogation Experiment (PROMETHEE [F. Jallu, A. Mariani, C. Passard, A.-C. Raoux, H. Toubon, Alpha low level waste control: improvement of the PROMETHEE 6 assay system performances. Nucl. Technol. 153 (January) (2006); C. Passard, A. Mariani, F. Jallu, J. Romeyer-Dherber, H. Recroix, M. Rodriguez, J. Loridon, C. Denis, PROMETHEE: an alpha low level waste assay system using passive and active neutron measurement methods. Nucl. Technol. 140 (December) (2002) 303-314]) based on ANI has been under development since 1996 to reach the incinerating α low level waste (LLW) criterion of about 50 Bq[α] per gram of crude waste (≈50 μg Pu) in 118 l drums on the date the drums are conditioned. Difficulties arise when dealing with matrices containing neutron energy moderators such as H and neutron absorbents such as Cl. These components may have a great influence on the fissile mass deduced from the neutron signal measured by ANI. For example, the calibration coefficient measured in a 118 l drum containing a cellulose matrix (density d = 0.144 g cm -3) may be 50 times higher than that obtained in a poly-vinyl-chloride matrix ( d = 0.253 g cm -3). Without any information on the matrix, the fissile mass is often overestimated due to safety procedures and by considering the most disadvantageous calibration coefficient corresponding to the most absorbing and moderating calibration matrix. The work discussed in this paper was performed at the CEA Nuclear Measurement Laboratory in France. It concerns the development of a matrix effect correction method, which consists in identifying and quantifying

Improvement of non-destructive fissile mass assays in α low-level waste drums: A matrix correction method based on neutron capture gamma-rays and a neutron generator

International Nuclear Information System (INIS)

Jallu, F.; Loche, F.

2008-01-01

Within the framework of radioactive waste control, non-destructive assay (NDA) methods may be employed. The active neutron interrogation (ANI) method is now well-known and effective in quantifying low α-activity fissile masses (mainly 235 U, 239 Pu, 241 Pu) with low densities, i.e. less than about 0.4, in radioactive waste drums of volumes up to 200 l. The PROMpt Epithermal and THErmal interrogation Experiment (PROMETHEE [F. Jallu, A. Mariani, C. Passard, A.-C. Raoux, H. Toubon, Alpha low level waste control: improvement of the PROMETHEE 6 assay system performances. Nucl. Technol. 153 (January) (2006); C. Passard, A. Mariani, F. Jallu, J. Romeyer-Dherber, H. Recroix, M. Rodriguez, J. Loridon, C. Denis, PROMETHEE: an alpha low level waste assay system using passive and active neutron measurement methods. Nucl. Technol. 140 (December) (2002) 303-314]) based on ANI has been under development since 1996 to reach the incinerating α low level waste (LLW) criterion of about 50 Bq[α] per gram of crude waste (∼50 μg Pu) in 118 l drums on the date the drums are conditioned. Difficulties arise when dealing with matrices containing neutron energy moderators such as H and neutron absorbents such as Cl. These components may have a great influence on the fissile mass deduced from the neutron signal measured by ANI. For example, the calibration coefficient measured in a 118 l drum containing a cellulose matrix (density d = 0.144 g cm -3 ) may be 50 times higher than that obtained in a poly-vinyl-chloride matrix (d = 0.253 g cm -3 ). Without any information on the matrix, the fissile mass is often overestimated due to safety procedures and by considering the most disadvantageous calibration coefficient corresponding to the most absorbing and moderating calibration matrix. The work discussed in this paper was performed at the CEA Nuclear Measurement Laboratory in France. It concerns the development of a matrix effect correction method, which consists in identifying and

Improvement of non-destructive fissile mass assays in {alpha} low-level waste drums: A matrix correction method based on neutron capture gamma-rays and a neutron generator

Energy Technology Data Exchange (ETDEWEB)

Jallu, F. [Commissariat a l' Energie Atomique, CEA, DEN, Nuclear Measurement Laboratory, Bat. 224, 13108 Saint Paul lez Durance (France)], E-mail: fanny.jallu@cea.fr; Loche, F. [Commissariat a l' Energie Atomique, CEA, DEN, Nuclear Measurement Laboratory, Bat. 224, 13108 Saint Paul lez Durance (France)

2008-08-15

Within the framework of radioactive waste control, non-destructive assay (NDA) methods may be employed. The active neutron interrogation (ANI) method is now well-known and effective in quantifying low {alpha}-activity fissile masses (mainly {sup 235}U, {sup 239}Pu, {sup 241}Pu) with low densities, i.e. less than about 0.4, in radioactive waste drums of volumes up to 200 l. The PROMpt Epithermal and THErmal interrogation Experiment (PROMETHEE [F. Jallu, A. Mariani, C. Passard, A.-C. Raoux, H. Toubon, Alpha low level waste control: improvement of the PROMETHEE 6 assay system performances. Nucl. Technol. 153 (January) (2006); C. Passard, A. Mariani, F. Jallu, J. Romeyer-Dherber, H. Recroix, M. Rodriguez, J. Loridon, C. Denis, PROMETHEE: an alpha low level waste assay system using passive and active neutron measurement methods. Nucl. Technol. 140 (December) (2002) 303-314]) based on ANI has been under development since 1996 to reach the incinerating {alpha} low level waste (LLW) criterion of about 50 Bq[{alpha}] per gram of crude waste ({approx}50 {mu}g Pu) in 118 l drums on the date the drums are conditioned. Difficulties arise when dealing with matrices containing neutron energy moderators such as H and neutron absorbents such as Cl. These components may have a great influence on the fissile mass deduced from the neutron signal measured by ANI. For example, the calibration coefficient measured in a 118 l drum containing a cellulose matrix (density d = 0.144 g cm{sup -3}) may be 50 times higher than that obtained in a poly-vinyl-chloride matrix (d = 0.253 g cm{sup -3}). Without any information on the matrix, the fissile mass is often overestimated due to safety procedures and by considering the most disadvantageous calibration coefficient corresponding to the most absorbing and moderating calibration matrix. The work discussed in this paper was performed at the CEA Nuclear Measurement Laboratory in France. It concerns the development of a matrix effect correction

Hairy AdS solitons

International Nuclear Information System (INIS)

Anabalón, Andrés; Astefanesei, Dumitru; Choque, David

2016-01-01

We construct exact hairy AdS soliton solutions in Einstein-dilaton gravity theory. We examine their thermodynamic properties and discuss the role of these solutions for the existence of first order phase transitions for hairy black holes. The negative energy density associated to hairy AdS solitons can be interpreted as the Casimir energy that is generated in the dual filed theory when the fermions are antiperiodic on the compact coordinate.

Hairy AdS solitons

Energy Technology Data Exchange (ETDEWEB)

Anabalón, Andrés, E-mail: andres.anabalon@uai.cl [Departamento de Ciencias, Facultad de Artes Liberales and Facultad de Ingeniería y Ciencias, Universidad Adolfo Ibáñez, Av. Padre Hurtado 750, Viña del Mar (Chile); Astefanesei, Dumitru, E-mail: dumitru.astefanesei@pucv.cl [Instituto de Física, Pontificia Universidad Católica de Valparaíso, Casilla 4059, Valparaíso (Chile); Choque, David, E-mail: brst1010123@gmail.com [Instituto de Física, Pontificia Universidad Católica de Valparaíso, Casilla 4059, Valparaíso (Chile); Universidad Técnica Federico Santa María, Av. España 1680, Valparaíso (Chile)

2016-11-10

We construct exact hairy AdS soliton solutions in Einstein-dilaton gravity theory. We examine their thermodynamic properties and discuss the role of these solutions for the existence of first order phase transitions for hairy black holes. The negative energy density associated to hairy AdS solitons can be interpreted as the Casimir energy that is generated in the dual filed theory when the fermions are antiperiodic on the compact coordinate.

The kinetic energy operator for distance-dependent effective nuclear masses: Derivation for a triatomic molecule.

Science.gov (United States)

Khoma, Mykhaylo; Jaquet, Ralph

2017-09-21

The kinetic energy operator for triatomic molecules with coordinate or distance-dependent nuclear masses has been derived. By combination of the chain rule method and the analysis of infinitesimal variations of molecular coordinates, a simple and general technique for the construction of the kinetic energy operator has been proposed. The asymptotic properties of the Hamiltonian have been investigated with respect to the ratio of the electron and proton mass. We have demonstrated that an ad hoc introduction of distance (and direction) dependent nuclear masses in Cartesian coordinates preserves the total rotational invariance of the problem. With the help of Wigner rotation functions, an effective Hamiltonian for nuclear motion can be derived. In the derivation, we have focused on the effective trinuclear Hamiltonian. All necessary matrix elements are given in closed analytical form. Preliminary results for the influence of non-adiabaticity on vibrational band origins are presented for H 3 + .

Compensation of matrix effects in gas chromatography-mass spectrometry analysis of pesticides using a combination of matrix matching and multiple isotopically labeled internal standards.

Science.gov (United States)

Tsuchiyama, Tomoyuki; Katsuhara, Miki; Nakajima, Masahiro

2017-11-17

In the multi-residue analysis of pesticides using GC-MS, the quantitative results are adversely affected by a phenomenon known as the matrix effect. Although the use of matrix-matched standards is considered to be one of the most practical solutions to this problem, complete removal of the matrix effect is difficult in complex food matrices owing to their inconsistency. As a result, residual matrix effects can introduce analytical errors. To compensate for residual matrix effects, we have developed a novel method that employs multiple isotopically labeled internal standards (ILIS). The matrix effects of ILIS and pesticides were evaluated in spiked matrix extracts of various agricultural commodities, and the obtained data were subjected to simple statistical analysis. Based on the similarities between the patterns of variation in the analytical response, a total of 32 isotopically labeled compounds were assigned to 338 pesticides as internal standards. It was found that by utilizing multiple ILIS, residual matrix effects could be effectively compensated. The developed method exhibited superior quantitative performance compared with the common single-internal-standard method. The proposed method is more feasible for regulatory purposes than that using only predetermined correction factors and is considered to be promising for practical applications. Copyright © 2017 Elsevier B.V. All rights reserved.

AdS solutions through transgression

International Nuclear Information System (INIS)

Donos, Aristomenis; Gauntlett, Jerome P.; Kim, Nakwoo

2008-01-01

We present new classes of explicit supersymmetric AdS 3 solutions of type IIB supergravity with non-vanishing five-form flux and AdS 2 solutions of D = 11 supergravity with electric four-form flux. The former are dual to two-dimensional SCFTs with (0,2) supersymmetry and the latter to supersymmetric quantum mechanics with two supercharges. We also investigate more general classes of AdS 3 solutions of type IIB supergravity and AdS 2 solutions of D = 11 supergravity which in addition have non-vanishing three-form flux and magnetic four-form flux, respectively. The construction of these more general solutions makes essential use of the Chern-Simons or 'transgression' terms in the Bianchi identity or the equation of motion of the field strengths in the supergravity theories. We construct infinite new classes of explicit examples and for some of the type IIB solutions determine the central charge of the dual SCFTs. The type IIB solutions with non-vanishing three-form flux that we construct include a two-torus, and after two T-dualities and an S-duality, we obtain new AdS 3 solutions with only the NS fields being non-trivial.

Mass formulae for broken supersymmetry in curved space-time

Energy Technology Data Exchange (ETDEWEB)

Ferrara, Sergio [Theoretical Physics Department, CERN, Geneva (Switzerland); INFN - Laboratori Nazionali di Frascati, Frascati (Italy); Department of Physics and Astronomy, U.C.L.A, Los Angeles, CA (United States); Proeyen, Antoine van [KU Leuven, Institute for Theoretical Physics, Leuven (Belgium)

2016-11-15

We derive the mass formulae for N = 1, D = 4 matter-coupled Supergravity for broken (and unbroken) Supersymmetry in curved space-time. These formulae are applicable to De Sitter configurations as is the case for inflation. For unbroken Supersymmetry in anti-de Sitter (AdS) one gets the mass relations modified by the AdS curvature. We compute the mass relations both for the potential and its derivative non-vanishing. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Trace detection of organic compounds in complex sample matrixes by single photon ionization ion trap mass spectrometry: real-time detection of security-relevant compounds and online analysis of the coffee-roasting process.

Science.gov (United States)

Schramm, Elisabeth; Kürten, Andreas; Hölzer, Jasper; Mitschke, Stefan; Mühlberger, Fabian; Sklorz, Martin; Wieser, Jochen; Ulrich, Andreas; Pütz, Michael; Schulte-Ladbeck, Rasmus; Schultze, Rainer; Curtius, Joachim; Borrmann, Stephan; Zimmermann, Ralf

2009-06-01

An in-house-built ion trap mass spectrometer combined with a soft ionization source has been set up and tested. As ionization source, an electron beam pumped vacuum UV (VUV) excimer lamp (EBEL) was used for single-photon ionization. It was shown that soft ionization allows the reduction of fragmentation of the target analytes and the suppression of most matrix components. Therefore, the combination of photon ionization with the tandem mass spectrometry (MS/MS) capability of an ion trap yields a powerful tool for molecular ion peak detection and identification of organic trace compounds in complex matrixes. This setup was successfully tested for two different applications. The first one is the detection of security-relevant substances like explosives, narcotics, and chemical warfare agents. One test substance from each of these groups was chosen and detected successfully with single photon ionization ion trap mass spectrometry (SPI-ITMS) MS/MS measurements. Additionally, first tests were performed, demonstrating that this method is not influenced by matrix compounds. The second field of application is the detection of process gases. Here, exhaust gas from coffee roasting was analyzed in real time, and some of its compounds were identified using MS/MS studies.

Matrix precipitation: a general strategy to eliminate matrix interference for pharmaceutical toxic impurities analysis.

Science.gov (United States)

Yang, Xiaojing; Xiong, Xuewu; Cao, Ji; Luan, Baolei; Liu, Yongjun; Liu, Guozhu; Zhang, Lei

2015-01-30

Matrix interference, which can lead to false positive/negative results, contamination of injector or separation column, incompatibility between sample solution and the selected analytical instrument, and response inhibition or even quenching, is commonly suffered for the analysis of trace level toxic impurities in drug substance. In this study, a simple matrix precipitation strategy is proposed to eliminate or minimize the above stated matrix interference problems. Generally, a sample of active pharmaceutical ingredients (APIs) is dissolved in an appropriate solvent to achieve the desired high concentration and then an anti-solvent is added to precipitate the matrix substance. As a result, the target analyte is extracted into the mixed solution with very less residual of APIs. This strategy has the characteristics of simple manipulation, high recovery and excellent anti-interference capability. It was found that the precipitation ratio (R, representing the ability to remove matrix substance) and the proportion of solvent (the one used to dissolve APIs) in final solution (P, affecting R and also affecting the method sensitivity) are two important factors of the precipitation process. The correlation between R and P was investigated by performing precipitation with various APIs in different solvent/anti-solvent systems. After a detailed mathematical reasoning process, P=20% was proved to be an effective and robust condition to perform the precipitation strategy. The precipitation method with P=20% can be used as a general strategy for toxic impurity analysis in APIs. Finally, several typical examples are described in this article, where the challenging matrix interference issues have been resolved successfully. Copyright © 2014 Elsevier B.V. All rights reserved.

Highly sensitive bacterial susceptibility test against penicillin using parylene-matrix chip.

Science.gov (United States)

Park, Jong-Min; Kim, Jo-Il; Song, Hyun-Woo; Noh, Joo-Yoon; Kang, Min-Jung; Pyun, Jae-Chul

2015-09-15

This work presented a highly sensitive bacterial antibiotic susceptibility test through β-lactamase assay using Parylene-matrix chip. β-lactamases (EC 3.5.2.6) are an important family of enzymes that confer resistance to β-lactam antibiotics by catalyzing the hydrolysis of these antibiotics. Here we present a highly sensitive assay to quantitate β-lactamase-mediated hydrolysis of penicillin into penicilloic acid. Typically, MALDI-TOF mass spectrometry has been used to quantitate low molecular weight analytes and to discriminate them from noise peaks of matrix fragments that occur at low m/z ratios (m/ztest was carried out using Parylene-matrix chip and MALDI-TOF mass spectrometry. The Parylene-matrix chip was successfully used to quantitate penicillin (m/z: [PEN+H](+)=335.1 and [PEN+Na](+)=357.8) and penicilloic acid (m/z: [PA+H](+)=353.1) in a β-lactamase assay with minimal interference of low molecular weight noise peaks. The β-lactamase assay was carried out with an antibiotic-resistant E. coli strain and an antibiotic-susceptible E. coli strain, revealing that the minimum number of E. coli cells required to screen for antibiotic resistance was 1000 cells for the MALDI-TOF mass spectrometry/Parylene-matrix chip assay. Copyright © 2015 Elsevier B.V. All rights reserved.

Matrix elements of Δ B =0 operators in heavy hadron chiral perturbation theory

Science.gov (United States)

Lee, Jong-Wan

2015-05-01

We study the light-quark mass and spatial volume dependence of the matrix elements of Δ B =0 four-quark operators relevant for the determination of Vu b and the lifetime ratios of single-b hadrons. To this end, one-loop diagrams are computed in the framework of heavy hadron chiral perturbation theory with partially quenched formalism for three light-quark flavors in the isospin limit; flavor-connected and -disconnected diagrams are carefully analyzed. These calculations include the leading light-quark flavor and heavy-quark spin symmetry breaking effects in the heavy hadron spectrum. Our results can be used in the chiral extrapolation of lattice calculations of the matrix elements to the physical light-quark masses and to infinite volume. To provide insight on such chiral extrapolation, we evaluate the one-loop contributions to the matrix elements containing external Bd, Bs mesons and Λb baryon in the QCD limit, where sea and valence quark masses become equal. In particular, we find that the matrix elements of the λ3 flavor-octet operators with an external Bd meson receive the contributions solely from connected diagrams in which current lattice techniques are capable of precise determination of the matrix elements. Finite volume effects are at most a few percent for typical lattice sizes and pion masses.

Detection of lung cancer using plasma protein profiling by matrix-assisted laser desorption/ionization mass spectrometry.

Science.gov (United States)

Shevchenko, Valeriy E; Arnotskaya, Natalia E; Zaridze, David G

2010-01-01

There are no satisfactory plasma biomarkers which are available for the early detection and monitoring of lung cancer, one of the most frequent cancers worldwide. The aim of this study is to explore the application of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-ToF MS) to plasma proteomic patterns to distinguish lung cancer patients from healthy individuals. The EDTA plasma samples have been pre-fractionated using magnetic bead kits functionalized with weak cation exchange coatings. We compiled MS protein profiles for 90 patients with squamous cell carcinomas (SCC) and compared them with profiles from 187 healthy controls. The MALDI-ToF spectra were analyzed statistically using ClinProTools bioinformatics software. Depending on the sample used, up to 441 peaks/spectrum could be detected in a mass range of 1000-20,000 Da; 33 of these proteins had statistically differential expression levels between SCC and control plasma (P 90%) in external validation test. These results suggest that plasma MALDI-ToF MS protein profiling can distinguish patients with SCC and also from healthy individuals with relatively high sensitivity and specificity and that MALDI- ToF MS is a potential tool for the screening of lung cancer.

Naturally Occurring Extracellular Matrix Scaffolds for Dermal Regeneration: Do They Really Need Cells?

Directory of Open Access Journals (Sweden)

A. M. Eweida

2015-01-01

Full Text Available The pronounced effect of extracellular matrix (ECM scaffolds in supporting tissue regeneration is related mainly to their maintained 3D structure and their bioactive components. These decellularized matrix scaffolds could be revitalized before grafting via adding stem cells, fibroblasts, or keratinocytes to promote wound healing. We reviewed the online published literature in the last five years for the studies that performed ECM revitalization and discussed the results of these studies and the related literature. Eighteen articles met the search criteria. Twelve studies included adding cells to acellular dermal matrix (ADM, 3 studies were on small intestinal mucosa (SIS, one study was on urinary bladder matrix (UBM, one study was on amniotic membrane, and one study included both SIS and ADM loaded constructs. We believe that, in chronic and difficult-to-heal wounds, revitalizing the ECM scaffolds would be beneficial to overcome the defective host tissue interaction. This belief still has to be verified by high quality randomised clinical trials, which are still lacking in literature.

A quantitative approach for pesticide analysis in grape juice by direct interfacing of a matrix compatible SPME phase to dielectric barrier discharge ionization-mass spectrometry.

Science.gov (United States)

Mirabelli, Mario F; Gionfriddo, Emanuela; Pawliszyn, Janusz; Zenobi, Renato

2018-02-12

We evaluated the performance of a dielectric barrier discharge ionization (DBDI) source for pesticide analysis in grape juice, a fairly complex matrix due to the high content of sugars (≈20% w/w) and pigments. A fast sample preparation method based on direct immersion solid-phase microextraction (SPME) was developed, and novel matrix compatible SPME fibers were used to reduce in-source matrix suppression effects. A high resolution LTQ Orbitrap mass spectrometer allowed for rapid quantification in full scan mode. This direct SPME-DBDI-MS approach was proven to be effective for the rapid and direct analysis of complex sample matrices, with limits of detection in the parts-per-trillion (ppt) range and inter- and intra-day precision below 30% relative standard deviation (RSD) for samples spiked at 1, 10 and 10 ng ml -1 , with overall performance comparable or even superior to existing chromatographic approaches.

The Origin of Mass

OpenAIRE

森岡, 達史

2013-01-01

The quark-lepton mass problem and the ideas of mass protection are reviewed. The hierarchy problem and suggestions for its resolution, including Little Higgs models, are discussed. The Multiple Point Principle is introduced and used within the Standard Model to predict the top quark and Higgs particle masses. Mass matrix ans\\"{a}tze are considered; in particular we discuss the lightest family mass generation model, in which all the quark mixing angles are successfully expressed in terms of si...

Suspensions of polymer-grafted nanoparticles with added polymers-Structure and effective pair-interactions.

Science.gov (United States)

Chandran, Sivasurender; Saw, Shibu; Kandar, A K; Dasgupta, C; Sprung, M; Basu, J K

2015-08-28

We present the results of combined experimental and theoretical (molecular dynamics simulations and integral equation theory) studies of the structure and effective interactions of suspensions of polymer grafted nanoparticles (PGNPs) in the presence of linear polymers. Due to the absence of systematic experimental and theoretical studies of PGNPs, it is widely believed that the structure and effective interactions in such binary mixtures would be very similar to those of an analogous soft colloidal material-star polymers. In our study, polystyrene-grafted gold nanoparticles with functionality f = 70 were mixed with linear polystyrene (PS) of two different molecular weights for obtaining two PGNP:PS size ratios, ξ = 0.14 and 2.76 (where, ξ = Mg/Mm, Mg and Mm being the molecular weights of grafting and matrix polymers, respectively). The experimental structure factor of PGNPs could be modeled with an effective potential (Model-X), which has been found to be widely applicable for star polymers. Similarly, the structure factor of the blends with ξ = 0.14 could be modeled reasonably well, while the structure of blends with ξ = 2.76 could not be captured, especially for high density of added polymers. A model (Model-Y) for effective interactions between PGNPs in a melt of matrix polymers also failed to provide good agreement with the experimental data for samples with ξ = 2.76 and high density of added polymers. We tentatively attribute this anomaly in modeling the structure factor of blends with ξ = 2.76 to the questionable assumption of Model-X in describing the added polymers as star polymers with functionality 2, which gets manifested in both polymer-polymer and polymer-PGNP interactions especially at higher fractions of added polymers. The failure of Model-Y may be due to the neglect of possible many-body interactions among PGNPs mediated by matrix polymers when the fraction of added polymers is high. These observations point to the need for a new framework to

Neutrino mass matrices with vanishing determinant

International Nuclear Information System (INIS)

Chauhan, Bhag C.; Pulido, Joao; Picariello, Marco

2006-01-01

We investigate the prospects for neutrinoless double beta decay, texture zeros. and equalities between neutrino mass matrix elements in scenarios with vanishing determinant mass matrices for vanishing and finite θ 13 mixing angles in normal and inverse mass hierarchies. For normal hierarchy and both zero and finite θ 13 it is found that neutrinoless double beta decay cannot be observed by any of the present or next generation experiments, while for inverse hierarchy it is, on the contrary, accessible to experiments. Regarding texture zeros and equalities between mass matrix elements, we find that in both normal and inverse hierarchies with θ 13 =0 no texture zeros nor any such equalities can exist apart from the obvious ones. For θ 13 ≠0 some texture zeros become possible. In normal hierarchy two texture zeros occur if 8.1x10 -2 ≤sinθ 13 ≤9.1x10 -2 while in inverse hierarchy three are possible, one with sinθ 13 ≥7x10 -3 and two others with sinθ 13 ≥0.18. All equalities between mass matrix elements are impossible with θ 13 ≠0

Evaluation of the added mass for a spheroid-type unmanned underwater vehicle by vertical planar motion mechanism test

Directory of Open Access Journals (Sweden)

Seong-Keon Lee

2011-09-01

Full Text Available This paper shows added mass and inertia can be acquired from the pure heaving motion and pure pitching motion respectively. A Vertical Planar Motion Mechanism (VPMM test for the spheroid-type Unmanned Underwater Vehicle (UUV was compared with a theoretical calculation and Computational Fluid Dynamics (CFD analysis in this paper. The VPMM test has been carried out at a towing tank with specially manufactured equipment. The linear equations of motion on the vertical plane were considered for theoretical calculation, and CFD results were obtained by commercial CFD package. The VPMM test results show good agreement with theoretical calculations and the CFD results, so that the applicability of the VPMM equipment for an underwater vehicle can be verified with a sufficient accuracy.

The characterisation of molecular boric acid by mass spectrometry and matrix isolation-infrared spectroscopy

International Nuclear Information System (INIS)

Ogden, J.S.; Young, N.A.; Bowsher, B.R.

1987-10-01

Boric acid (H 3 BO 3 ) is used as a soluble neutron absorber in the coolant of pressurised water reactors and will be an important species in defining the fission product chemistry of severe reactor accidents. Mass spectrometry and matrix isolation-infrared spectroscopy have been used to characterise boric acid in the vapour phase and hence assess the implications of any chemical interactions. Crystalline orthoboric acid vaporises to yield molecular H 3 BO 3 when heated in vacuum to approximately 40 0 C. The infrared spectrum of the vapour species isolated in low-temperature nitrogen matrices shows characteristic absorptions at 3668.5 (E'), 1426.2 (E'), 1009.9 (E'), 675.0 (A''), 513.8 (A'') and 448.9 (E') cm -1 , consistent with C 3h symmetry. These spectral assignments are supported by extensive isotope labelling, and by a partial normal co-ordinate analysis. These data will be used to quantify specific thermodynamic functions and hence assist in determining the magnitude of reactions such as boric acid with caesium iodide. (author)

Orbifold matrix models and fuzzy extra dimensions

CERN Document Server

Chatzistavrakidis, Athanasios; Zoupanos, George

2011-01-01

We revisit an orbifold matrix model obtained as a restriction of the type IIB matrix model on a Z_3-invariant sector. An investigation of its moduli space of vacua is performed and issues related to chiral gauge theory and gravity are discussed. Modifications of the orbifolded model triggered by Chern-Simons or mass deformations are also analyzed. Certain vacua of the modified models exhibit higher-dimensional behaviour with internal geometries related to fuzzy spheres.

Ghost peaks observed after atmospheric pressure matrix-assisted laser desorption/ionization experiments may disclose new ionization mechanism of matrix-assisted hypersonic velocity impact ionization.

Science.gov (United States)

Moskovets, Eugene

2015-08-30

Understanding the mechanisms of matrix-assisted laser desorption/ionization (MALDI) promises improvements in the sensitivity and specificity of many established applications in the field of mass spectrometry. This paper reports a serendipitous observation of a significant ion yield in a post-ionization experiment conducted after the sample had been removed from a standard atmospheric pressure (AP)-MALDI source. This post-ionization is interpreted in terms of collisions of microparticles moving with a hypersonic velocity into a solid surface. Calculations show that the thermal energy released during such collisions is close to that absorbed by the top matrix layer in traditional MALDI. The microparticles, containing both the matrix and analytes, could be detached from a film produced inside the inlet capillary during the sample ablation and accelerated by the flow rushing through the capillary. These observations contribute some new perspective to ion formation in both laser and laser-less matrix-assisted ionization. An AP-MALDI ion source hyphenated with a three-stage high-pressure ion funnel system was utilized for peptide mass analysis. After the laser had been turned off and the MALDI sample removed, ions were detected during a gradual reduction of the background pressure in the first funnel. The constant-rate pressure reduction led to the reproducible appearance of different singly and doubly charged peptide peaks in mass spectra taken a few seconds after the end of the MALDI analysis of a dried-droplet spot. The ion yield as well as the mass range of ions observed with a significant delay after a completion of the primary MALDI analysis depended primarily on the background pressure inside the first funnel. The production of ions in this post-ionization step was exclusively observed during the pressure drop. A lower matrix background and significant increase in relative yield of double-protonated ions are reported. The observations were partially consistent

Evaluation of Aerosol Mixing State Classes in the GISS Modele-matrix Climate Model Using Single-particle Mass Spectrometry Measurements

Science.gov (United States)

Bauer, Susanne E.; Ault, Andrew; Prather, Kimberly A.

2013-01-01

Aerosol particles in the atmosphere are composed of multiple chemical species. The aerosol mixing state, which describes how chemical species are mixed at the single-particle level, provides critical information on microphysical characteristics that determine the interaction of aerosols with the climate system. The evaluation of mixing state has become the next challenge. This study uses aerosol time-of-flight mass spectrometry (ATOFMS) data and compares the results to those of the Goddard Institute for Space Studies modelE-MATRIX (Multiconfiguration Aerosol TRacker of mIXing state) model, a global climate model that includes a detailed aerosol microphysical scheme. We use data from field campaigns that examine a variety of air mass regimens (urban, rural, and maritime). At all locations, polluted areas in California (Riverside, La Jolla, and Long Beach), a remote location in the Sierra Nevada Mountains (Sugar Pine) and observations from Jeju (South Korea), the majority of aerosol species are internally mixed. Coarse aerosol particles, those above 1 micron, are typically aged, such as coated dust or reacted sea-salt particles. Particles below 1 micron contain large fractions of organic material, internally-mixed with sulfate and black carbon, and few external mixtures. We conclude that observations taken over multiple weeks characterize typical air mass types at a given location well; however, due to the instrumentation, we could not evaluate mass budgets. These results represent the first detailed comparison of single-particle mixing states in a global climate model with real-time single-particle mass spectrometry data, an important step in improving the representation of mixing state in global climate models.

Matrix-assisted laser desorption-ionization mass spectrometry peptide mass fingerprinting for proteome analysis: identification efficiency after on-blot or in-gel digestion with and without desalting procedures.

Science.gov (United States)

Lamer, S; Jungblut, P R

2001-03-10

In theory, peptide mass fingerprinting by matrix assisted laser desorption-ionization mass spectrometry (MALDI-MS) has the potential to identify all of the proteins detected by silver staining on gels. In practice, if the genome of the organism investigated is completely sequenced, using current techniques, all proteins stained by Coomassie Brilliant Blue can be identified. This loss of identification sensitivity of ten to hundred-fold is caused by loss of peptides by surface contacts. Therefore, we performed digestion and transfer of peptides in the lower microl range and reduced the number of steps. The peptide mix obtained from in-gel or on-blot digestion was analyzed directly after digestion or after concentration on POROS R2 beads. Eight protein spots of a 2-DE gel from Mycobacterium bovis BCG were identified using these four preparation procedures for MALDI-MS. Overall, on-blot digestion was as effective as in-gel digestion. Whereas higher signal intensities resulted after concentration, hydrophilic peptides are better detected by direct measurement of the peptide mix without POROS R2 concentration.

Influence of boron on ferrite formation in copper-added spheroidal graphite cast iron

Directory of Open Access Journals (Sweden)

Ying Zou

2014-07-01

Full Text Available This paper reviews the original work of the authors published recently, describing the influence of B on the matrix of the Cuadded spheroidal graphite cast iron. The effect of Cu has been corrected as a ferrite formation promoter in the matrix of the grey cast iron by the usage of high-purity material. Also, this paper focuses on the ferrite formation and the observation of the Cu distribution in the B-added and B-free Cu-containing spheroidal graphite cast iron. The Cu film on the spheroidal graphite can be successfully observed in the B-free sample using a special etching method. However, in the B-added sample, no Cu film could be found, while the secondary graphite was formed on the surface of the spheroidal graphite. The interaction between B and Cu is stressed as a peculiar phenomenon by the employment of a contrast experiment of B and Mn. The heat treatment could make Cu precipitate more significantly in the eutectic cells and in the matrix in the form of large Cu particles because of the limited solubility of Cu.

Hidden sector behind the CKM matrix

Science.gov (United States)

Okawa, Shohei; Omura, Yuji

2017-08-01

The small quark mixing, described by the Cabibbo-Kobayashi-Maskawa (CKM) matrix in the standard model, may be a clue to reveal new physics around the TeV scale. We consider a simple scenario that extra particles in a hidden sector radiatively mediate the flavor violation to the quark sector around the TeV scale and effectively realize the observed CKM matrix. The lightest particle in the hidden sector, whose contribution to the CKM matrix is expected to be dominant, is a good dark matter (DM) candidate. There are many possible setups to describe this scenario, so that we investigate some universal predictions of this kind of model, focusing on the contribution of DM to the quark mixing and flavor physics. In this scenario, there is an explicit relation between the CKM matrix and flavor violating couplings, such as four-quark couplings, because both are radiatively induced by the particles in the hidden sector. Then, we can explicitly find the DM mass region and the size of Yukawa couplings between the DM and quarks, based on the study of flavor physics and DM physics. In conclusion, we show that DM mass in our scenario is around the TeV scale, and the Yukawa couplings are between O (0.01 ) and O (1 ). The spin-independent DM scattering cross section is estimated as O (10-9) [pb]. An extra colored particle is also predicted at the O (10 ) TeV scale.

Exploration of polyamide structure-property relationships by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry.

Science.gov (United States)

Barrère, Caroline; Rejaibi, Majed; Curat, Aurélien; Hubert-Roux, Marie; Lavanant, Hélène; Afonso, Carlos; Kebir, Nasreddine; Desilles, Nicolas; Lecamp, Laurence; Burel, Fabrice; Loutelier-Bourhis, Corinne

2014-08-15

Polyamides (PA) are among the most used classes of polymers because of their attractive properties. Depending on the nature and proportion of the co-monomers used for their synthesis, they can exhibit a very large range of melting temperatures (Tm ). This study aims at the correlation of data from mass spectrometry (MS) with differential scanning calorimetry (DSC) and X-ray diffraction analyses to relate molecular structure to physical properties such as melting temperature, enthalpy change and crystallinity rate. Six different PA copolymers with molecular weights around 3500 g mol(-1) were synthesized with varying proportions of different co-monomers (amino-acid AB/di-amine AA/di-acid BB). Their melting temperature, enthalpy change and crystallinity rate were measured by DSC and X-ray diffraction. Their structural characterization was carried out by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). Because of the poor solubility of PA, a solvent-free sample preparation strategy was used with 2,5-dihydroxybenzoic acid (2,5-DHB) as the matrix and sodium iodide as the cationizing agent. The different proportions of the repeating unit types led to the formation of PA with melting temperatures ranging from 115°C to 185°C. The structural characterization of these samples by MALDI-TOF-MS revealed a collection of different ion distributions with different sequences of repeating units (AA, BB; AB/AA, BB and AB) in different proportions according to the mixture of monomers used in the synthesis. The relative intensities of these ion distributions were related to sample complexity and structure. They were correlated to DSC and X-ray results, to explain the observed physical properties. The structural information obtained by MALDI-TOF-MS provided a better understanding of the variation of the PA melting temperature and established a structure-properties relationship. This work will allow future PA designs to be monitored. Copyright

Hawking radiation from AdS black holes

International Nuclear Information System (INIS)

Hubeny, Veronika E; Rangamani, Mukund; Marolf, Donald

2010-01-01

We study Hartle-Hawking-like states of quantum field theories on asymptotically AdS black hole backgrounds, with particular regard to the phase structure of interacting theories. By a suitable analytic continuation we show that the equilibrium dynamics of field theories on large asymptotically AdS black holes can be related to the low-temperature states of the same field theory on the AdS soliton (or pure AdS) background. This allows us to gain insight into Hartle-Hawking-like states on large-radius Schwarzschild- or rotating-AdS black holes. Furthermore, we exploit the AdS/CFT correspondence to explore the physics of strongly coupled large N theories on asymptotically AdS black holes. In particular, we exhibit a plausibly complete set of phases for the M2-brane world-volume superconformal field theory on a BTZ black hole background. Our analysis partially resolves puzzles previously raised in connection with Hawking radiation on large AdS black holes.

Acid-base-driven matrix-assisted mass spectrometry for targeted metabolomics

Czech Academy of Sciences Publication Activity Database

Shroff, R.; Rulíšek, Lubomír; Doubský, J.; Svatoš, Aleš

2009-01-01

Roč. 106, č. 25 (2009), s. 10092-10096 ISSN 0027-8424 R&D Projects: GA MŠk LC512 Institutional research plan: CEZ:AV0Z40550506 Keywords : clinical diagnostic * matrix design * positive/negative ions * MALDI Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 9.432, year: 2009

Matrix effect and correction by standard addition in quantitative liquid chromatographic-mass spectrometric analysis of diarrhetic shellfish poisoning toxins.

Science.gov (United States)

Ito, Shinya; Tsukada, Katsuo

2002-01-11

An evaluation of the feasibility of liquid chromatography-mass spectrometry (LC-MS) with atmospheric pressure ionization was made for quantitation of four diarrhetic shellfish poisoning toxins, okadaic acid, dinophysistoxin-1, pectenotoxin-6 and yessotoxin in scallops. When LC-MS was applied to the analysis of scallop extracts, large signal suppressions were observed due to coeluting substances from the column. To compensate for these matrix signal suppressions, the standard addition method was applied. First, the sample was analyzed and then the sample involving the addition of calibration standards is analyzed. Although this method requires two LC-MS runs per analysis, effective correction of quantitative errors was found.

Secondary decay of espalation in ADS reactors

International Nuclear Information System (INIS)

Rodrigues, Marcos Guedes; Santiago, A.J.; Silva, C.E. da

2013-01-01

We study the problem of evaporation in the context of nuclear spallation reactions in nuclear reactors ADS. The calculation was developed based on the theory of Weisskopf evaporation and in the model of thermal liquid drop. Evaporation affects the 'economy' of neutrons and the design of a ADS reactor in various aspects. It offers abundant amount of neutrons in the nuclear medium, with a wide energy range. For an excitation energy of 3 MeV/n a typical core evaporates about 10% of its mass in the form of light particles (mostly neutrons)

A simple algorithm improves mass accuracy to 50-100 ppm for delayed extraction linear MALDI-TOF mass spectrometry

Energy Technology Data Exchange (ETDEWEB)

Hack, Christopher A.; Benner, W. Henry

2001-10-31

A simple mathematical technique for improving mass calibration accuracy of linear delayed extraction matrix assisted laser desorption ionization time-of-flight mass spectrometry (DE MALDI-TOF MS) spectra is presented. The method involves fitting a parabola to a plot of Dm vs. mass data where Dm is the difference between the theoretical mass of calibrants and the mass obtained from a linear relationship between the square root of m/z and ion time of flight. The quadratic equation that describes the parabola is then used to correct the mass of unknowns by subtracting the deviation predicted by the quadratic equation from measured data. By subtracting the value of the parabola at each mass from the calibrated data, the accuracy of mass data points can be improved by factors of 10 or more. This method produces highly similar results whether or not initial ion velocity is accounted for in the calibration equation; consequently, there is no need to depend on that uncertain parameter when using the quadratic correction. This method can be used to correct the internally calibrated masses of protein digest peaks. The effect of nitrocellulose as a matrix additive is also briefly discussed, and it is shown that using nitrocellulose as an additive to a CHCA matrix does not significantly change initial ion velocity but does change the average position of ions relative to the sample electrode at the instant the extraction voltage is applied.

Polarised Black Holes in AdS

CERN Document Server

Costa, Miguel S.; Oliveira, Miguel; Penedones, João; Santos, Jorge E.

2016-05-03

We consider solutions in Einstein-Maxwell theory with a negative cosmological constant that asymptote to global $AdS_{4}$ with conformal boundary $S^{2}\\times\\mathbb{R}_{t}$. At the sphere at infinity we turn on a space-dependent electrostatic potential, which does not destroy the asymptotic $AdS$ behaviour. For simplicity we focus on the case of a dipolar electrostatic potential. We find two new geometries: (i) an $AdS$ soliton that includes the full backreaction of the electric field on the $AdS$ geometry; (ii) a polarised neutral black hole that is deformed by the electric field, accumulating opposite charges in each hemisphere. For both geometries we study boundary data such as the charge density and the stress tensor. For the black hole we also study the horizon charge density and area, and further verify a Smarr formula. Then we consider this system at finite temperature and compute the Gibbs free energy for both $AdS$ soliton and black hole phases. The corresponding phase diagram generalizes the Hawkin...

Comparison of matrix methods for elastic wave scattering problems

International Nuclear Information System (INIS)

Tsao, S.J.; Varadan, V.K.; Varadan, V.V.

1983-01-01

This article briefly describes the T-matrix method and the MOOT (method of optimal truncation) of elastic wave scattering as they apply to A-D, SH- wave problems as well as 3-D elastic wave problems. Two methods are compared for scattering by elliptical cylinders as well as oblate spheroids of various eccentricity as a function of frequency. Convergence, and symmetry of the scattering cross section are also compared for ellipses and spheroidal cavities of different aspect ratios. Both the T-matrix approach and the MOOT were programmed on an AMDHL 470 computer using double precision arithmetic. Although the T-matrix method and MOOT are not always in agreement, it is in no way implied that any of the published results using MOOT are in error

Performance of matrix-assisted laser desorption-time of flight mass spectrometry for identification of clinical yeast isolates

DEFF Research Database (Denmark)

Rosenvinge, Flemming S; Dzajic, Esad; Knudsen, Elisa

2013-01-01

Accurate and fast yeast identification is important when treating patients with invasive fungal disease as susceptibility to antifungal agents is highly species related. Matrix-assisted laser desorption-time of flight mass spectrometry (MALDI-TOF-MS) provides a powerful tool with a clear potential...... spectra output, all 13 isolates were correctly identified, resulting in an overall identification performance of 92%. No misidentifications occurred with the two systems. Of the routine isolates one laboratory identified 99/99 (100%) and 90/99 (91%) to species level by Saramis/Axima and conventional...... identification, respectively, whereas the other laboratory identified 83/98 (85%) to species level by both BioTyper/Bruker and conventional identification. Both MALDI-TOF-MS systems are fast, have built-in databases that cover the majority of clinically relevant Candida species, and have an accuracy...

Ambient Profiling of Phenolic Content in Tea Infusions by Matrix-Assisted Ionization in Vacuum

Science.gov (United States)

Cody, Robert B.

2018-05-01

Matrix-assisted ionization in vacuum (MAIV) was used to analyze the polyphenol content of ten different tea infusions. Nine different Camellia sinensis infusions were analyzed including three green teas, two black teas, two oolong teas, jasmine tea, and white tea. An infusion of rooibos (Aspalathus linearis) tea was also analyzed. Each freshly brewed tea was diluted 1:1 with methanol, and 100 ppm of phenolphthalein was added as an internal standard. An excess of 3-nitrobenzonitrile (NBN) was added to each vial, and the solution containing NBN crystals was analyzed by aspiration directly into the mass spectrometer sampling orifice. A working curve constructed for dilutions of catechin with phenolphthalein internal standard showed good linearity for five replicates of each concentration. The measured relative abundances of flavonoid polyphenols in each tea were in good agreement with previously reported values. Polyphenol content in tea infusions varied from 19.2 to 108.6 mg 100 mL-1. In addition to the expected catechin flavonoids, abundant quinic acid and gallic acid was detected in the C. sinensis infusions. Characteristic A. linearis flavonoids were detected in the rooibos tea.

A rotating hairy AdS3 black hole with the metric having only one Killing vector field

International Nuclear Information System (INIS)

Iizuka, Norihiro; Ishibashi, Akihiro; Maeda, Kengo

2015-01-01

We perturbatively construct a three-dimensional rotating AdS black hole with a real scalar hair. We choose the mass of a scalar field slightly above the Breitenlohner-Freedman bound and impose a general boundary condition for the bulk scalar field at AdS infinity. We first show that rotating BTZ black holes are unstable against scalar field perturbations under our more general boundary condition. Next we construct a rotating hairy black hole perturbatively with respect to a small amplitude ϵ of the scalar field, up to O(ϵ 4 ). Our hairy black hole is stationary and exhibits no dissipation, but the lumps of the non-linearly perturbed geometry break axial symmetry, thus providing the first example of a rotating black hole whose metric admits only one Killing vector field. Furthermore, we numerically show that the entropy of our hairy black hole is larger than that of the BTZ black hole with the same energy and the angular momentum. We briefly discuss if our rotating hairy black hole in lumpy geometry could be the endpoint of the instability.

Holographic thermalization and generalized Vaidya-AdS solutions in massive gravity

International Nuclear Information System (INIS)

Hu, Ya-Peng; Zeng, Xiao-Xiong; Zhang, Hai-Qing

2017-01-01

We investigate the effect of massive graviton on the holographic thermalization process. Before doing this, we first find out the generalized Vaidya-AdS solutions in the de Rham–Gabadadze–Tolley (dRGT) massive gravity by directly solving the gravitational equations. Then, we study the thermodynamics of these Vaidya-AdS solutions by using the Misner–Sharp energy and unified first law, which also shows that the massive gravity is in a thermodynamic equilibrium state. Moreover, we adopt the two-point correlation function at equal time to explore the thermalization process in the dual field theory, and to see how the graviton mass parameter affects this process from the viewpoint of AdS/CFT correspondence. Our results show that the graviton mass parameter will increase the holographic thermalization process.

Holographic thermalization and generalized Vaidya-AdS solutions in massive gravity

Science.gov (United States)

Hu, Ya-Peng; Zeng, Xiao-Xiong; Zhang, Hai-Qing

2017-02-01

We investigate the effect of massive graviton on the holographic thermalization process. Before doing this, we first find out the generalized Vaidya-AdS solutions in the de Rham-Gabadadze-Tolley (dRGT) massive gravity by directly solving the gravitational equations. Then, we study the thermodynamics of these Vaidya-AdS solutions by using the Misner-Sharp energy and unified first law, which also shows that the massive gravity is in a thermodynamic equilibrium state. Moreover, we adopt the two-point correlation function at equal time to explore the thermalization process in the dual field theory, and to see how the graviton mass parameter affects this process from the viewpoint of AdS/CFT correspondence. Our results show that the graviton mass parameter will increase the holographic thermalization process.

Holographic thermalization and generalized Vaidya-AdS solutions in massive gravity

Energy Technology Data Exchange (ETDEWEB)

Hu, Ya-Peng, E-mail: huyp@nuaa.edu.cn [College of Science, Nanjing University of Aeronautics and Astronautics, Nanjing 210016 (China); Instituut-Lorentz for Theoretical Physics, Leiden University, Niels Bohrweg 2, Leiden 2333 CA (Netherlands); State Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, Beijing, 100190 (China); Zeng, Xiao-Xiong, E-mail: xxzengphysics@163.com [State Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, Beijing, 100190 (China); School of Science, Chongqing Jiaotong University, Chongqing 400074 (China); Zhang, Hai-Qing, E-mail: H.Q.Zhang@uu.nl [Institute for Theoretical Physics, Center for Extreme Matter and Emergent Phenomena, Utrecht University, Princetonplein 5, 3584 CC Utrecht (Netherlands)

2017-02-10

We investigate the effect of massive graviton on the holographic thermalization process. Before doing this, we first find out the generalized Vaidya-AdS solutions in the de Rham–Gabadadze–Tolley (dRGT) massive gravity by directly solving the gravitational equations. Then, we study the thermodynamics of these Vaidya-AdS solutions by using the Misner–Sharp energy and unified first law, which also shows that the massive gravity is in a thermodynamic equilibrium state. Moreover, we adopt the two-point correlation function at equal time to explore the thermalization process in the dual field theory, and to see how the graviton mass parameter affects this process from the viewpoint of AdS/CFT correspondence. Our results show that the graviton mass parameter will increase the holographic thermalization process.

Nano-fillers to tune Young’s modulus of silicone matrix

International Nuclear Information System (INIS)

Xia Lijin; Xu Zhonghua; Sun Leming; Caveney, Patrick M.; Zhang Mingjun

2013-01-01

In this study, we investigated nanoparticles, nanofibers, and nanoclays for their filler effects on tuning the Young’s modulus of silicone matrix, a material with broad in vivo applications. Nano-fillers with different shapes, sizes, and surface properties were added into silicone matrix, and then their filler effects were evaluated through experimental studies. It was found that spherical nanoparticles could clearly improve Young’s modulus of the silicone matrix, while nanoclays and carbon nanofibers had limited effects. Smaller spherical nanoparticles were better in performance compared to larger nanoparticles. In addition, enhanced distribution of the nanoparticles in the matrix has been observed to improve the filler effect. In order to minimize toxicity of the nanoparticles for in vivo applications, spherical nanoparticles coated with amine, acid, or hydroxide groups were also investigated, but they were found only to diminish the filler effect of nanoparticles. This study demonstrated that spherical nanoparticles could serve as fillers to tune Young’s modulus of silicone matrix for potential applications in medicine.

Detection of lipid-induced structural changes of the Marburg virus matrix protein VP40 using hydrogen/deuterium exchange-mass spectrometry.

Science.gov (United States)

Wijesinghe, Kaveesha J; Urata, Sarah; Bhattarai, Nisha; Kooijman, Edgar E; Gerstman, Bernard S; Chapagain, Prem P; Li, Sheng; Stahelin, Robert V

2017-04-14

Marburg virus (MARV) is a lipid-enveloped virus from the Filoviridae family containing a negative sense RNA genome. One of the seven MARV genes encodes the matrix protein VP40, which forms a matrix layer beneath the plasma membrane inner leaflet to facilitate budding from the host cell. MARV VP40 (mVP40) has been shown to be a dimeric peripheral protein with a broad and flat basic surface that can associate with anionic phospholipids such as phosphatidylserine. Although a number of mVP40 cationic residues have been shown to facilitate binding to membranes containing anionic lipids, much less is known on how mVP40 assembles to form the matrix layer following membrane binding. Here we have used hydrogen/deuterium exchange (HDX) mass spectrometry to determine the solvent accessibility of mVP40 residues in the absence and presence of phosphatidylserine and phosphatidylinositol 4,5-bisphosphate. HDX analysis demonstrates that two basic loops in the mVP40 C-terminal domain make important contributions to anionic membrane binding and also reveals a potential oligomerization interface in the C-terminal domain as well as a conserved oligomerization interface in the mVP40 N-terminal domain. Lipid binding assays confirm the role of the two basic patches elucidated with HD/X measurements, whereas molecular dynamics simulations and membrane insertion measurements complement these studies to demonstrate that mVP40 does not appreciably insert into the hydrocarbon region of anionic membranes in contrast to the matrix protein from Ebola virus. Taken together, we propose a model by which association of the mVP40 dimer with the anionic plasma membrane facilitates assembly of mVP40 oligomers. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Ion yields in UV-MALDI mass spectrometry as a function of excitation laser wavelength and optical and physico-chemical properties of classical and halogen-substituted MALDI matrixes.

Science.gov (United States)

Soltwisch, Jens; Jaskolla, Thorsten W; Hillenkamp, Franz; Karas, Michael; Dreisewerd, Klaus

2012-08-07

The laser wavelength constitutes a key parameter in ultraviolet-matrix-assisted laser desorption ionization-mass spectrometry (UV-MALDI-MS). Optimal analytical results are only achieved at laser wavelengths that correspond to a high optical absorption of the matrix. In the presented work, the wavelength dependence and the contribution of matrix proton affinity to the MALDI process were investigated. A tunable dye laser was used to examine the wavelength range between 280 and 355 nm. The peptide and matrix ion signals recorded as a function of these irradiation parameters are displayed in the form of heat maps, a data representation that furnishes multidimensional data interpretation. Matrixes with a range of proton affinities from 809 to 866 kJ/mol were investigated. Among those selected are the standard matrixes 2,5-dihydroxybenzoic acid (DHB) and α-cyano-4-hydroxycinnamic acid (HCCA) as well as five halogen-substituted cinnamic acid derivatives, including the recently introduced 4-chloro-α-cyanocinnamic acid (ClCCA) and α-cyano-2,4-difluorocinnamic acid (DiFCCA) matrixes. With the exception of DHB, the highest analyte ion signals were obtained toward the red side of the peak optical absorption in the solid state. A stronger decline of the molecular analyte ion signals generated from the matrixes was consistently observed at the low wavelength side of the peak absorption. This effect is mainly the result of increased fragmentation of both analyte and matrix ions. Optimal use of multiply halogenated matrixes requires adjustment of the excitation wavelength to values below that of the standard MALDI lasers emitting at 355 (Nd:YAG) or 337 nm (N(2) laser). The combined data provide new insights into the UV-MALDI desorption/ionization processes and indicate ways to improve the analytical sensitivity.

Modeling and Inferring Aircraft Takeoff Mass from Runway ADS-B Data

NARCIS (Netherlands)

Sun, J.; Ellerbroek, J.; Hoekstra, J.M.; Lovell, D.; Fricke, H.

2016-01-01

Aircraft mass is an important parameter in many ways, either to build aircraft performance models, to predict flight trajectories, or to simulate air traffic. Mass data is usually considered as sensitive information for airlines and is, therefore, not disclosed to researchers publicly. In this

Matrix effect on emission/current correlated analysis in laser-induced breakdown spectroscopy of liquid droplets

International Nuclear Information System (INIS)

Huang, J.-S.; Ke, C.-B.; Lin, K.-C.

2004-01-01

We have investigated influence of matrix salts on the liquid droplets by laser-induced breakdown spectroscopy (LIBS). An electrospray ionization technique coupled with LIBS is employed to generate the microdroplets of the Na sample solution with various matrix salts added. A sequence of single-shot time-resolved LIB emission signals is detected. The LIB signal intensity integrated within a gate linearly correlates with the plasma-induced current response obtained simultaneously on a single-shot basis. The slopes thus obtained increase with the sample concentration, but appear to be irrespective of different matrix salts, added up to a 2000 mg/l concentration. The matrix salts involved have the same K + cation but different anions. Given a laser radiation emitting at 355 nm with the energy fixed at 23±1 mJ, a limit of detection (LOD) of 1.0 mg/l may be achieved for the Na analysis. The current normalization might have probably taken into account the ablated amount of the sample and the plasma temperature. Accordingly, the LIB/current correlated analysis becomes efficient to suppress the signal fluctuation, improve the LOD determination, and concurrently correct the matrix effect

Neutrino mass models and CP violation

International Nuclear Information System (INIS)

Joshipura, Anjan S.

2011-01-01

Theoretical ideas on the origin of (a) neutrino masses (b) neutrino mass hierarchies and (c) leptonic mixing angles are reviewed. Topics discussed include (1) symmetries of neutrino mass matrix and their origin (2) ways to understand the observed patterns of leptonic mixing angles and (3)unified description of neutrino masses and mixing angles in grand unified theories.

Neutrino mass priors for cosmology from random matrices

Science.gov (United States)

Long, Andrew J.; Raveri, Marco; Hu, Wayne; Dodelson, Scott

2018-02-01

Cosmological measurements of structure are placing increasingly strong constraints on the sum of the neutrino masses, Σ mν, through Bayesian inference. Because these constraints depend on the choice for the prior probability π (Σ mν), we argue that this prior should be motivated by fundamental physical principles rather than the ad hoc choices that are common in the literature. The first step in this direction is to specify the prior directly at the level of the neutrino mass matrix Mν, since this is the parameter appearing in the Lagrangian of the particle physics theory. Thus by specifying a probability distribution over Mν, and by including the known squared mass splittings, we predict a theoretical probability distribution over Σ mν that we interpret as a Bayesian prior probability π (Σ mν). Assuming a basis-invariant probability distribution on Mν, also known as the anarchy hypothesis, we find that π (Σ mν) peaks close to the smallest Σ mν allowed by the measured mass splittings, roughly 0.06 eV (0.1 eV) for normal (inverted) ordering, due to the phenomenon of eigenvalue repulsion in random matrices. We consider three models for neutrino mass generation: Dirac, Majorana, and Majorana via the seesaw mechanism; differences in the predicted priors π (Σ mν) allow for the possibility of having indications about the physical origin of neutrino masses once sufficient experimental sensitivity is achieved. We present fitting functions for π (Σ mν), which provide a simple means for applying these priors to cosmological constraints on the neutrino masses or marginalizing over their impact on other cosmological parameters.

Matrix separation by chelation to prepare biological materials for isotopic zinc analysis by inductively coupled plasma mass spectrometry

International Nuclear Information System (INIS)

Durrant, S.F.; Krushevska, A.; Amarasiriwardena, D.; Argentine, M.D.; Romon-Guesnier, S.; Barnes, R.M.

1994-01-01

Following an evaluation of three chelating resins [Chelex-100, poly(dithiocarbamate) (PDTC) and carboxymethylated poly(ethyleneimine)-poly(methylenepolyphenylene) isocyanate (CPPI)], a procedure was established with the last of these for the separation of Zn from biological matrix elements prior to 70 Zn: 68 Zn isotopic analysis by inductively coupled plasma mass spectrometry (ICP-MS). The method was verified by establishing Zn recoveries and by determining its effectiveness in removing Cl and Na from buffered test solutions. Calcium, Na, and Zn concentration data were determined by inductively coupled plasma atomic emission spectrometry. Chlorine was measured by electrothermal vaporization ICP-MS. The efficacy of the technique was demonstrated by the determination of zinc isotope ratios in bovine milk and human urine. (Author)

Multi-class multi-residue analysis of veterinary drugs in meat using enhanced matrix removal lipid cleanup and liquid chromatography-tandem mass spectrometry.

Science.gov (United States)

Zhao, Limian; Lucas, Derick; Long, David; Richter, Bruce; Stevens, Joan

2018-05-11

This study presents the development and validation of a quantitation method for the analysis of multi-class, multi-residue veterinary drugs using lipid removal cleanup cartridges, enhanced matrix removal lipid (EMR-Lipid), for different meat matrices by liquid chromatography tandem mass spectrometry detection. Meat samples were extracted using a two-step solid-liquid extraction followed by pass-through sample cleanup. The method was optimized based on the buffer and solvent composition, solvent additive additions, and EMR-Lipid cartridge cleanup. The developed method was then validated in five meat matrices, porcine muscle, bovine muscle, bovine liver, bovine kidney and chicken liver to evaluate the method performance characteristics, such as absolute recoveries and precision at three spiking levels, calibration curve linearity, limit of quantitation (LOQ) and matrix effect. The results showed that >90% of veterinary drug analytes achieved satisfactory recovery results of 60-120%. Over 97% analytes achieved excellent reproducibility results (relative standard deviation (RSD) meat matrices. The matrix co-extractive removal efficiency by weight provided by EMR-lipid cartridge cleanup was 42-58% in samples. The post column infusion study showed that the matrix ion suppression was reduced for samples with the EMR-Lipid cartridge cleanup. The reduced matrix ion suppression effect was also confirmed with 30%) for all tested veterinary drugs in all of meat matrices. The results showed that the two-step solid-liquid extraction provides efficient extraction for the entire spectrum of veterinary drugs, including the difficult classes such as tetracyclines, beta-lactams etc. EMR-Lipid cartridges after extraction provided efficient sample cleanup with easy streamlined protocol and minimal impacts on analytes recovery, improving method reliability and consistency. Copyright © 2018 Elsevier B.V. All rights reserved.

Q Value of the Superallowed Decay of 46V and Its Influence on Vud and the Unitarity of the Cabibbo-Kobayashi-Maskawa Matrix

International Nuclear Information System (INIS)

Savard, G.; Buchinger, F.; Crawford, J.E.; Gulick, S.; Lee, J.K.P.; Clark, J.A.; Sharma, H.; Sharma, K.S.; Hardy, J.C.; Hecht, A.A.; Levand, A.F.; Scielzo, N.D.; Tanihata, I.; Villari, A.C.C.; Wang, Y.

2005-01-01

The masses of the radioactive nuclei 46 V and its decay daughter 46 Ti have been measured with the Canadian Penning Trap on-line Penning trap mass spectrometer to a precision of 1x10 -8 . A Q EC value of 7052.90(40) keV for the superallowed beta decay of 46 V is obtained from the difference of these two masses. With this precise Q value, the Ft value for this decay is determined with improved precision. An investigation of an earlier Q-value measurement for 46 V uncovers a set of 7 measurements that cannot be reconciled with modern data and affects previous evaluations of V ud from superallowed Fermi decays. A new evaluation, adding our new data and removing the discredited subset, yields new values for G V and V ud . When combined with recent results for V us , this yields modified constraints for the unitarity of the Cabibbo-Kobayashi-Maskawa matrix and other extensions of the standard model

Arbitrary spin conformal fields in (A)dS

International Nuclear Information System (INIS)

Metsaev, R.R.

2014-01-01

Totally symmetric arbitrary spin conformal fields in (A)dS space of even dimension greater than or equal to four are studied. Ordinary-derivative and gauge invariant Lagrangian formulation for such fields is obtained. Gauge symmetries are realized by using auxiliary fields and Stueckelberg fields. We demonstrate that Lagrangian of conformal field is decomposed into a sum of gauge invariant Lagrangians for massless, partial-massless, and massive fields. We obtain a mass spectrum of the partial-massless and massive fields and confirm the conjecture about the mass spectrum made in the earlier literature. In contrast to conformal fields in flat space, the kinetic terms of conformal fields in (A)dS space turn out to be diagonal with respect to fields entering the Lagrangian. Explicit form of conformal transformation which maps conformal field in flat space to conformal field in (A)dS space is obtained. Covariant Lorentz-like and de-Donder like gauge conditions leading to simple gauge-fixed Lagrangian of conformal fields are proposed. Using such gauge-fixed Lagrangian, which is invariant under global BRST transformations, we explain how the partition function of conformal field is obtained in the framework of our approach

A survey of useful salt additives in matrix-assisted laser desorption/ionization mass spectrometry and tandem mass spectrometry of lipids: introducing nitrates for improved analysis.

Science.gov (United States)

Griffiths, Rian L; Bunch, Josephine

2012-07-15

Matrix-assisted laser desorption/ionization (MALDI) is a powerful technique for the direct analysis of lipids in complex mixtures and thin tissue sections, making it an extremely attractive method for profiling lipids in health and disease. Lipids are readily detected as [M+H](+), [M+Na](+) and [M+K](+) ions in positive ion MALDI mass spectrometry (MS) experiments. This not only decreases sensitivity, but can also lead to overlapping m/z values of the various adducts of different lipids. Additives can be used to promote formation of a particular adduct, improving sensitivity, reducing spectral complexity and enhancing structural characterization in collision-induced dissociation (CID) experiments. Li(+), Na(+), K(+), Cs(+) and NH(4)(+) cations were considered as a range of salt types (acetates, chlorides and nitrates) incorporated into DHB matrix solutions at concentrations between 5 and 80 mM. The study was extended to evaluate the effect of these additives on CID experiments of a lipid standard, after optimization of collision energy parameters. Experiments were performed on a hybrid quadrupole time-of-flight (QqTOF) instrument. The systematic evaluation of new and existing additives in MALDI-MS and MS/MS of lipids demonstrated the importance of additive cation and anion choice and concentration for tailoring spectral results. The recommended choice of additive depends on the desired outcomes of the experiment to be performed (MS or MS/MS). Nitrates are found to be particularly useful additives for lipid analysis. Copyright © 2012 John Wiley & Sons, Ltd.

Efficiency criterion for teleportation via channel matrix, measurement matrix and collapsed matrix

Directory of Open Access Journals (Sweden)

Xin-Wei Zha

Full Text Available In this paper, three kinds of coefficient matrixes (channel matrix, measurement matrix, collapsed matrix associated with the pure state for teleportation are presented, the general relation among channel matrix, measurement matrix and collapsed matrix is obtained. In addition, a criterion for judging whether a state can be teleported successfully is given, depending on the relation between the number of parameter of an unknown state and the rank of the collapsed matrix. Keywords: Channel matrix, Measurement matrix, Collapsed matrix, Teleportation

Superconformal Chern-Simons theories and AdS4/CFT3 correspondence

International Nuclear Information System (INIS)

Benna, Marcus; Klebanov, Igor; Klose, Thomas; Smedbaeck, Mikael

2008-01-01

We discuss the N = 2 superspace formulation of the N = 8 superconformal Bagger-Lambert-Gustavsson theory, and of the N = 6 superconformal Aharony-Bergman-Jafferis-Maldacena U(N) x U(N) Chern-Simons theory. In particular, we prove the full SU(4) R-symmetry of the ABJM theory. We then consider orbifold projections of this theory that give non-chiral and chiral (U(N) x U(N)) n superconformal quiver gauge theories. We argue that these theories are dual to certain AdS 4 x S 7 /(Z n x Z k -tilde) backgrounds of M-theory. We also study a SU(3) invariant mass term in the superpotential that makes the N = 8 theory flow to a N = 2 superconformal gauge theory with a sextic superpotential. We conjecture that this gauge theory is dual to the U(1) R x SU(3) invariant extremum of the N = 8 gauged supergravity, which was discovered by N. Warner 25 years ago and whose uplifting to 11 dimensions was found more recently.

String Theory on AdS Spaces

NARCIS (Netherlands)

de Boer, J.

2000-01-01

In these notes we discuss various aspects of string theory in AdS spaces. We briefly review the formulation in terms of Green-Schwarz, NSR, and Berkovits variables, as well as the construction of exact conformal field theories with AdS backgrounds. Based on lectures given at the Kyoto YITP Workshop

In situ analysis of plant tissue underivatized carbohydrates and on-probe enzymatic degraded starch by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry by using carbon nanotubes as matrix.

Science.gov (United States)

Gholipour, Yousef; Nonami, Hiroshi; Erra-Balsells, Rosa

2008-12-15

Underivatized carbohydrates of tulip bulb and leaf tissues were characterized in situ by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) by using carbon nanotubes (CNTs) as matrix. Two sample preparation methods--(i) depositing CNTs on the fresh tissue slices placed on the probe and (ii) locating semitransparent tissues on a dried layer of CNTs on the probe--were examined. Furthermore, practicability of in situ starch analysis by MALDI-TOF MS was examined by detection of glucose originated from on-probe amyloglucosidase-catalyzed degradation of starch on the tissue surface. Besides, CNTs could efficiently desorb/ionize natural mono-, di-, and oligosaccharides extracted from tulip bulb tissues as well as glucose resulting from starch enzymatic degradation in vitro. These results were compared with those obtained by in situ MALDI-TOF MS analysis of similar tissues. Positive ion mode showed superior signal reproducibility. CNTs deposited under semitransparent tissue could also desorb/ionize neutral carbohydrates, leading to nearly complete elimination of matrix cluster signals but with an increase in tissue-originated signals. Furthermore, several experiments were carried out to compare the efficiency of 2,5-dihydroxybenzoic acid, nor-harmane, alpha-cyano-4-hydroxycinnamic acid, and CNTs as matrices for MALDI of neutral carbohydrates from the intact plant tissue surface and for enzymatic tissue starch degradation; these results are discussed in brief. Among matrices studied, the lowest laser power was needed to acquire carbohydrate signals with high signal-to-noise ratio and resolution when CNTs were used.

Open strings on AdS2 branes

International Nuclear Information System (INIS)

Lee, Peter; Ooguri, Hirosi.; Park, Jongwon; Tannenhauser, Jonathan

2001-01-01

We study the spectrum of open strings on AdS 2 branes in AdS 3 in an NS-NS background, using the SL(2,R) WZW model. When the brane carries no fundamental string charge, the open string spectrum is the holomorphic square root of the spectrum of closed strings in AdS 3 . It contains short and long strings, and is invariant under spectral flow. When the brane carries fundamental string charge, the open string spectrum again contains short and long strings in all winding sectors. However, branes with fundamental string charge break half the spectral flow symmetry. This has different implications for short and long strings. As the fundamental string charge increases, the brane approaches the boundary of AdS 3 . In this limit, the induced electric field on the worldvolume reaches its critical value, producing noncommutative open string theory on AdS 2

Evaluation of matrix-assisted laser desorption ionization-time of flight mass spectrometry for identification of clinically important yeast species.

Science.gov (United States)

Stevenson, Lindsay G; Drake, Steven K; Shea, Yvonne R; Zelazny, Adrian M; Murray, Patrick R

2010-10-01

We evaluated the use of matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) for the rapid identification of yeast species. Using Bruker Daltonics MALDI BioTyper software, we created a spectral database library with m/z ratios of 2,000 to 20,000 Da for 109 type and reference strains of yeast (44 species in 8 genera). The database was tested for accuracy by use of 194 clinical isolates (23 species in 6 genera). A total of 192 (99.0%) of the clinical isolates were identified accurately by MALDI-TOF MS. The MALDI-TOF MS-based method was found to be reproducible and accurate, with low consumable costs and minimal preparation time.

Neutrino mass sum rules and symmetries of the mass matrix

Energy Technology Data Exchange (ETDEWEB)

Gehrlein, Julia [Karlsruhe Institute of Technology, Institut fuer Theoretische Teilchenphysik, Karlsruhe (Germany); Universidad Autonoma de Madrid, Departamento de Fisica Teorica, Madrid (Spain); Instituto de Fisica Teorica UAM/CSIC, Madrid (Spain); Spinrath, Martin [Karlsruhe Institute of Technology, Institut fuer Theoretische Teilchenphysik, Karlsruhe (Germany); National Center for Theoretical Sciences, Physics Division, Hsinchu (China)

2017-05-15

Neutrino mass sum rules have recently gained again more attention as a powerful tool to discriminate and test various flavour models in the near future. A related question which has not yet been discussed fully satisfactorily was the origin of these sum rules and if they are related to any residual or accidental symmetry. We will address this open issue here systematically and find previous statements confirmed. Namely, the sum rules are not related to any enhanced symmetry of the Lagrangian after family symmetry breaking but they are simply the result of a reduction of free parameters due to skillful model building. (orig.)

A Measurement of the Top Quark Mass with the D0 Detector at s**(1/2) = 1.96-TeV using the Matrix Element Method

Energy Technology Data Exchange (ETDEWEB)

Kroeninger, Kevin Alexander; /Bonn U.

2004-04-01

Using a data set of 158 and 169 pb{sup -1} of D0 Run-II data in the electron and muon plus jets channel, respectively, the top quark mass has been measured using the Matrix Element Method. The method and its implementation are described. Its performance is studied in Monte Carlo using ensemble tests and the method is applied to the Moriond 2004 data set.

Conical singularities in AdS space time

International Nuclear Information System (INIS)

Ferreira, Cristine Nunes

2011-01-01

Full text: In recent years, the study of conformal gauge theories from 10-D has been motivated by the AdS d+1 /CFT d correspondence, first conjectured by J. Maldacena. The aim of this work is to consider the d = 4 case by analysing the configuration of the N coincident D3 branes. In this context, the work shows that there is a duality between type IIB string theory in AdS 5 x S 5 and N = 4 SU(N) Super Yang-Mills Theory in the IR. The AdS 5 /CFT 4 correspondence brought also new approaches to the strong coupling problem in QCD. Nowadays, there is a whole line of works that focus on the low dimensional correspondence AdS 4 /CFT 3 , like the application to graphene and topological insulators, and the AdS 3 /CFT 2 correspondence, related with the entanglement entropy. In this work, we consider the vortex configuration solution to the AdS 4 and AdS 3 space-time. The most important motivation is to discuss the boundary theory resulting from these solutions. We have examined a straightforward approach to a holographic computation of the graphene and entanglement entropy in the presence of the conical singularity. After this analysis, we consider the scalar field in the bulk in the presence of this metrics and work out the compactification modes. Taking the holographic point of view, we study and discuss the resulting Green function. (author)

More about unphysical zeroes in quark mass matrices

Energy Technology Data Exchange (ETDEWEB)

Emmanuel-Costa, David, E-mail: david.costa@tecnico.ulisboa.pt [Departamento de Física and Centro de Física Teórica de Partículas - CFTP, Instituto Superior Técnico, Universidade de Lisboa, Avenida Rovisco Pais, 1049-001 Lisboa (Portugal); González Felipe, Ricardo, E-mail: ricardo.felipe@tecnico.ulisboa.pt [Departamento de Física and Centro de Física Teórica de Partículas - CFTP, Instituto Superior Técnico, Universidade de Lisboa, Avenida Rovisco Pais, 1049-001 Lisboa (Portugal); ISEL - Instituto Superior de Engenharia de Lisboa, Instituto Politécnico de Lisboa, Rua Conselheiro Emídio Navarro, 1959-007 Lisboa (Portugal)

2017-01-10

We look for all weak bases that lead to texture zeroes in the quark mass matrices and contain a minimal number of parameters in the framework of the standard model. Since there are ten physical observables, namely, six nonvanishing quark masses, three mixing angles and one CP phase, the maximum number of texture zeroes in both quark sectors is altogether nine. The nine zero entries can only be distributed between the up- and down-quark sectors in matrix pairs with six and three texture zeroes or five and four texture zeroes. In the weak basis where a quark mass matrix is nonsingular and has six zeroes in one sector, we find that there are 54 matrices with three zeroes in the other sector, obtainable through right-handed weak basis transformations. It is also found that all pairs composed of a nonsingular matrix with five zeroes and a nonsingular and nondecoupled matrix with four zeroes simply correspond to a weak basis choice. Without any further assumptions, none of these pairs of up- and down-quark mass matrices has physical content. It is shown that all non-weak-basis pairs of quark mass matrices that contain nine zeroes are not compatible with current experimental data. The particular case of the so-called nearest-neighbour-interaction pattern is also discussed.

Mass spectrometry

DEFF Research Database (Denmark)

Nyvang Hartmeyer, Gitte; Jensen, Anne Kvistholm; Böcher, Sidsel

2010-01-01

Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) is currently being introduced for the rapid and accurate identification of bacteria. We describe 2 MALDI-TOF MS identification cases - 1 directly on spinal fluid and 1 on grown bacteria. Rapidly obtained...

Top quark mass measurement in the dilepton electron-muon channel with the matrix element method in the ATLAS experiment at LHC

International Nuclear Information System (INIS)

Demilly, A.

2014-01-01

The LHC produced proton-proton collisions data at 7 TeV of center of mass energy in 2011 and 8 TeV in 2012, corresponding to an integrated luminosity of, respectively, 5 fb"-"1 and 23 fb"-"1. Data acquired by ATLAS have led to a better understanding of the detector and its performance, to many measurements of physical quantities and the discovery of the Higgs boson. Top quark is involved in many processes beyond the Standard Model. Its mass is an important parameter for the Standard Model and any New Physics theory, thus measuring its mass accurately is necessary. After a description of the Standard Model of Particle Physics, and the role of the top quark in it, the first half of this thesis describes the ATLAS detector and its electromagnetic calorimeter, for which a study of the calibration constant patching is detailed. The second half details top quark physics events detected in ATLAS and their selection. Theoretical aspects of the matrix element method and its implementation for the top quark mass measurement in the dilepton electron-muon channel in the experimental framework of ATLAS are discussed. The measurement calibration and optimisation studies for the analysis are presented. Finally, systematic uncertainties are described and estimated. This measurement yields a top quark mass of (173.65 ± 0.70 ± 2.36) GeV ; showing no discrepancy with current worldwide measurements. (author)

Gravitational lensing by eigenvalue distributions of random matrix models

Science.gov (United States)

Martínez Alonso, Luis; Medina, Elena

2018-05-01

We propose to use eigenvalue densities of unitary random matrix ensembles as mass distributions in gravitational lensing. The corresponding lens equations reduce to algebraic equations in the complex plane which can be treated analytically. We prove that these models can be applied to describe lensing by systems of edge-on galaxies. We illustrate our analysis with the Gaussian and the quartic unitary matrix ensembles.

The importance of matrix-assisted laser desorption ionization–time of flight mass spectrometry for correct identification of Clostridium difficile isolated from chromID C. difficile chromogenic agar

Directory of Open Access Journals (Sweden)

Jonathan H.K. Chen

2017-10-01

Full Text Available The clinical workflow of using chromogenic agar and matrix-assisted laser desorption ionization time-of-fight mass spectrometry (MALDI-TOF MS for Clostridium difficile identification was evaluated. The addition of MALDI-TOF MS identification after the chromID C. difficile chromogenic agar culture could significantly improve the diagnostic accuracy of C. difficile.

Direct Analyses of Secondary Metabolites by Mass Spectrometry Imaging (MSI) from Sunflower (Helianthus annuus L.) Trichomes.

Science.gov (United States)

Brentan Silva, Denise; Aschenbrenner, Anna-Katharina; Lopes, Norberto Peporine; Spring, Otmar

2017-05-10

Helianthus annuus (sunflower) displays non-glandular trichomes (NGT), capitate glandular trichomes (CGT), and linear glandular trichomes (LGT), which reveal different chemical compositions and locations in different plant tissues. With matrix-assisted laser desorption/ionization (MALDI) and laser desorption/ionization (LDI) mass spectrometry imaging (MSI) techniques, efficient methods were developed to analyze the tissue distribution of secondary metabolites (flavonoids and sesquiterpenes) and proteins inside of trichomes. Herein, we analyzed sesquiterpene lactones, present in CGT, from leaf transversal sections using the matrix 2,5-dihydroxybenzoic acid (DHB) and α-cyano-4-hydroxycinnamic acid (CHCA) (mixture 1:1) with sodium ions added to increase the ionization in positive ion mode. The results observed for sesquiterpenes and polymethoxylated flavones from LGT were similar. However, upon desiccation, LGT changed their shape in the ionization source, complicating analyses by MSI mainly after matrix application. An alternative method could be applied to LGT regions by employing LDI (without matrix) in negative ion mode. The polymethoxylated flavones were easily ionized by LDI, producing images with higher resolution, but the sesquiterpenes were not observed in spectra. Thus, the application and viability of MALDI imaging for the analyses of protein and secondary metabolites inside trichomes were confirmed, highlighting the importance of optimization parameters.

Microstructure and Strengthening Mechanisms of Carbon Nanotube Reinforced Magnesium Matrix Composites Fabricated by Accumulative Roll Bonding

International Nuclear Information System (INIS)

Yoo, Seong Jin; Kim, Woo Jin

2014-01-01

A combination of accumulative roll bonding (ARB) and high-energy ball milling was used to fabricate carbon nano tube (CNT)-reinforced Mg composites in sheet form. CNT-Al composite powders synthesized using the high-energy ball-milling process, were coated on the surface of Mg sheets using either spraying or dipping methods. The coated sheets were stacked and then subjected to ARB. Formation of CNT-intermetallic compounds through inter-diffusion between Al and Mg, fragmentation of the CNTintermetallic compounds, and their dispersion into the matrix by plastic flow; as well as dissolution of the intermetallic compound particles into the matrix while leaving CNTs in the matrix, occurred in sequence during the ARB process. This eventually resulted in the uniform distribution of nano-sized CNT particles in the Mg matrix. As the thickness of the Mg sheet and of the coating layer of Al-CNT powder on the surface of the Mg sheet were similar, the dispersion of CNTs into the Mg matrix occurred more uniformly and the strengthening effect of adding CNTs was greater. The strengthening gained by adding CNTs was attributed to Orowan strengthening and dislocation-density increase due to a thermal mismatch between the matrix and the CNTs.

Flavor symmetries and fermion masses

International Nuclear Information System (INIS)

Rasin, A.

1994-04-01

We introduce several ways in which approximate flavor symmetries act on fermions and which are consistent with observed fermion masses and mixings. Flavor changing interactions mediated by new scalars appear as a consequence of approximate flavor symmetries. We discuss the experimental limits on masses of the new scalars, and show that the masses can easily be of the order of weak scale. Some implications for neutrino physics are also discussed. Such flavor changing interactions would easily erase any primordial baryon asymmetry. We show that this situation can be saved by simply adding a new charged particle with its own asymmetry. The neutrality of the Universe, together with sphaleron processes, then ensures a survival of baryon asymmetry. Several topics on flavor structure of the supersymmetric grand unified theories are discussed. First, we show that the successful predictions for the Kobayashi-Maskawa mixing matrix elements, V ub /V cb = √m u /m c and V td /V ts = √m d /m s , are a consequence of a large class of models, rather than specific properties of a few models. Second, we discuss how the recent observation of the decay β → sγ constrains the parameter space when the ratio of the vacuum expectation values of the two Higgs doublets, tanΒ, is large. Finally, we discuss the flavor structure of proton decay. We observe a surprising enhancement of the branching ratio for the muon mode in SO(10) models compared to the same mode in the SU(5) model

A correction technique for the dispersive effects of mass lumping for transport problems

KAUST Repository

Guermond, Jean-Luc

2013-01-01

This paper addresses the well-known dispersion effect that mass lumping induces when solving transport-like equations. A simple anti-dispersion technique based on the lumped mass matrix is proposed. The method does not require any non-trivial matrix inversion and has the same anti-dispersive effects as the consistent mass matrix. A novel quasi-lumping technique for P2 finite elements is introduced. Higher-order extensions of the method are also discussed. © 2012 Elsevier B.V.

Quantification of the PR-39 cathelicidin compound in porcine blood by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry.

Science.gov (United States)

Smolira, Anna; Hałas, Stanisław; Wessely-Szponder, Joanna

2015-10-15

The PR-39 porcine cathelicidin occurs naturally in animal neutrophils. Its main function is antimicrobial activity, which potentially can be used in antibiotic treatments in veterinary medicine. Investigations concerning such a use require the detection and quantification of PR-39 in a given sample. The aim of this work is to determine the concentration of PR-39 contained in porcine blood. Prior to matrix-assisted laser desorption/ionization (MALDI) analysis, the porcine blood sample was subjected to crude extraction in order to release the active form of PR-39 from the neutrophil granules. Next, gel filtration chromatography was performed to separate PR-39 from other cathelicidins present in porcine blood. Positive ion MALDI time-of-flight (TOF) mass spectra of the resulting portion of lyophilisate with unknown PR-39 content were acquired in linear mode. To quantify PR-39 in the lyophilisate sample, the standard addition method was applied. The PR-39 concentration obtained in the lyophilisate sample was then converted into the peptide concentration in porcine blood. The linear fit function of the constructed calibration curve indicates an excellent correlation between the PR-39 peak intensity and the added quantity of synthetic PR-39 (R(2) = 0.994) and a low relative standard deviation of the slope = 1.98%. From the x-intercept of the straight line, we estimated the PR-39 concentration in porcine blood to be 20.5 ± 4.6 ng/mL. The MALDI method was successfully applied for the quantitative analysis of PR-39 found in porcine blood. Compared with other available methods, it is relatively easy, inexpensive and not time-consuming. Despite the method having lower accuracy than the enzyme-linked immunosorbent assay (ELISA), the results obtained here, by a much simpler method, are in good agreement with the literature data. Copyright © 2015 John Wiley & Sons, Ltd.

Systematics of quark mass

International Nuclear Information System (INIS)

Frampton, P.H.; Jarlskog, C.

1985-01-01

It is shown that the quark mass matrices in the Standard Electroweak Model satisfy the empirical relation M = M 1 + Ψ(Λ 2 ), where M(M sp (')) refers to the mass matrix of the charge 2/3(-1/3) quarks normalized to the largest eigenvalue, m sub (t)(m sub (b)), and Λ = V sub (us) = 0.22

Globally regular instability of AdS_3

OpenAIRE

Bizon, P.; Jałmużna, J.

2013-01-01

We consider three-dimensional AdS gravity minimally coupled to a massless scalar field and study numerically the evolution of small smooth circularly symmetric perturbations of the $AdS_3$ spacetime. As in higher dimensions, for a large class of perturbations, we observe a turbulent cascade of energy to high frequencies which entails instability of $AdS_3$. However, in contrast to higher dimensions, the cascade cannot be terminated by black hole formation because small perturbations have ener...

Appetite and food intake after consumption of sausages with 10% fat and added wheat or rye bran.

Science.gov (United States)

Vuholm, Stine; Arildsen Jakobsen, Louise Margrethe; Vejrum Sørensen, Karina; Kehlet, Ursula; Raben, Anne; Kristensen, Mette

2014-02-01

The use of dietary fibers as fat-replacers in sausages gives less energy-dense and thereby healthier foods. Also, dietary fibers have been shown to induce satiety. The objectives of this study were to investigate if appetite sensations and energy intake was affected by (1) addition of dietary fibers to sausages, (2) type of dietary fibers and (3) the food matrix of the dietary fibers. In this randomized cross-over study 25 young men were served four test meals; wheat bran sausages, rye bran sausages, rye bran bread and wheat flour sausages. The test meals were served as breakfast after an overnight fast. Appetite sensations were evaluated by visual analogue scales (VAS) assessed every 30 min for 240 min followed by an ad libitum lunch meal where energy intake was calculated. Both rye bran and wheat bran sausages increased satiety (P appetite sensations and thereby has a potential added health benefit beyond the role as fat-replacer. The satisfying effect of dietary fibers appears to be more pronounced when added to sausages than when added to bread, stressing the importance of food matrix and food processing.

Manifestly T-dual formulation of AdS space

International Nuclear Information System (INIS)

Hatsuda, Machiko; Kamimura, Kiyoshi; Siegel, Warren

2017-01-01

We present a manifestly T-dual formulation of curved spaces such as an AdS space. For group manifolds related by the orthogonal vielbein fields the three form H=dB in the doubled space is universal at least locally. We construct an affine nondegenerate doubled bosonic AdS algebra to define the AdS space with the Ramond-Ramond flux. The non-zero commutator of the left and right momenta leads to that the left momentum is in an AdS space while the right momentum is in a dS space. Dimensional reduction constraints and the physical AdS algebra are shown to preserve all the doubled coordinates.

Manifestly T-dual formulation of AdS space

Energy Technology Data Exchange (ETDEWEB)

Hatsuda, Machiko [Physics Division, Faculty of Medicine, Juntendo University,Chiba 270-1695 (Japan); KEK Theory Center, High Energy Accelerator Research Organization,Tsukuba, Ibaraki 305-0801 (Japan); Kamimura, Kiyoshi [Physics Division, Faculty of Medicine, Juntendo University,Chiba 270-1695 (Japan); Siegel, Warren [C.N. Yang Institute for Theoretical Physics, Stony Brook University,Stony Brook, NY 11794-3840 (United States)

2017-05-12

We present a manifestly T-dual formulation of curved spaces such as an AdS space. For group manifolds related by the orthogonal vielbein fields the three form H=dB in the doubled space is universal at least locally. We construct an affine nondegenerate doubled bosonic AdS algebra to define the AdS space with the Ramond-Ramond flux. The non-zero commutator of the left and right momenta leads to that the left momentum is in an AdS space while the right momentum is in a dS space. Dimensional reduction constraints and the physical AdS algebra are shown to preserve all the doubled coordinates.

Finite size effects of a pion matrix element

International Nuclear Information System (INIS)

Guagnelli, M.; Jansen, K.; Palombi, F.; Petronzio, R.; Shindler, A.; Wetzorke, I.

2004-01-01

We investigate finite size effects of the pion matrix element of the non-singlet, twist-2 operator corresponding to the average momentum of non-singlet quark densities. Using the quenched approximation, they come out to be surprisingly large when compared to the finite size effects of the pion mass. As a consequence, simulations of corresponding nucleon matrix elements could be affected by finite size effects even stronger which could lead to serious systematic uncertainties in their evaluation

Ubiquitination of specific mitochondrial matrix proteins

International Nuclear Information System (INIS)

Lehmann, Gilad; Ziv, Tamar; Braten, Ori; Admon, Arie; Udasin, Ronald G.; Ciechanover, Aaron

2016-01-01

Several protein quality control systems in bacteria and/or mitochondrial matrix from lower eukaryotes are absent in higher eukaryotes. These are transfer-messenger RNA (tmRNA), The N-end rule ATP-dependent protease ClpAP, and two more ATP-dependent proteases, HslUV and ClpXP (in yeast). The lost proteases resemble the 26S proteasome and the role of tmRNA and the N-end rule in eukaryotic cytosol is performed by the ubiquitin proteasome system (UPS). Therefore, we hypothesized that the UPS might have substituted these systems – at least partially – in the mitochondrial matrix of higher eukaryotes. Using three independent experimental approaches, we demonstrated the presence of ubiquitinated proteins in the matrix of isolated yeast mitochondria. First, we show that isolated mitochondria contain ubiquitin (Ub) conjugates, which remained intact after trypsin digestion. Second, we demonstrate that the mitochondrial soluble fraction contains Ub-conjugates, several of which were identified by mass spectrometry and are localized to the matrix. Third, using immunoaffinity enrichment by specific antibodies recognizing digested ubiquitinated peptides, we identified a group of Ub-modified matrix proteins. The modification was further substantiated by separation on SDS-PAGE and immunoblots. Last, we attempted to identify the ubiquitin ligase(s) involved, and identified Dma1p as a trypsin-resistant protein in our mitochondrial preparations. Taken together, these data suggest a yet undefined role for the UPS in regulation of the mitochondrial matrix proteins. -- Highlights: •Mitochondrial matrix contains ubiquitinated proteins. •Ubiquitination occurs most probably in the matrix. •Dma1p is a ubiquitin ligase present in mitochondrial preparations.

Ubiquitination of specific mitochondrial matrix proteins

Energy Technology Data Exchange (ETDEWEB)

Lehmann, Gilad [The Janet and David Polak Tumor and Vascular Biology Research Center and the Technion Integrated Cancer Center (TICC), The Rappaport Faculty of Medicine and Research Institute, Haifa, 31096 (Israel); Ziv, Tamar [The Smoler Proteomics Center, Faculty of Biology – Technion-Israel Institute of Technology, Haifa, 32000 (Israel); Braten, Ori [The Janet and David Polak Tumor and Vascular Biology Research Center and the Technion Integrated Cancer Center (TICC), The Rappaport Faculty of Medicine and Research Institute, Haifa, 31096 (Israel); Admon, Arie [The Smoler Proteomics Center, Faculty of Biology – Technion-Israel Institute of Technology, Haifa, 32000 (Israel); Udasin, Ronald G. [The Janet and David Polak Tumor and Vascular Biology Research Center and the Technion Integrated Cancer Center (TICC), The Rappaport Faculty of Medicine and Research Institute, Haifa, 31096 (Israel); Ciechanover, Aaron, E-mail: aaroncie@tx.technion.ac.il [The Janet and David Polak Tumor and Vascular Biology Research Center and the Technion Integrated Cancer Center (TICC), The Rappaport Faculty of Medicine and Research Institute, Haifa, 31096 (Israel)

2016-06-17

Several protein quality control systems in bacteria and/or mitochondrial matrix from lower eukaryotes are absent in higher eukaryotes. These are transfer-messenger RNA (tmRNA), The N-end rule ATP-dependent protease ClpAP, and two more ATP-dependent proteases, HslUV and ClpXP (in yeast). The lost proteases resemble the 26S proteasome and the role of tmRNA and the N-end rule in eukaryotic cytosol is performed by the ubiquitin proteasome system (UPS). Therefore, we hypothesized that the UPS might have substituted these systems – at least partially – in the mitochondrial matrix of higher eukaryotes. Using three independent experimental approaches, we demonstrated the presence of ubiquitinated proteins in the matrix of isolated yeast mitochondria. First, we show that isolated mitochondria contain ubiquitin (Ub) conjugates, which remained intact after trypsin digestion. Second, we demonstrate that the mitochondrial soluble fraction contains Ub-conjugates, several of which were identified by mass spectrometry and are localized to the matrix. Third, using immunoaffinity enrichment by specific antibodies recognizing digested ubiquitinated peptides, we identified a group of Ub-modified matrix proteins. The modification was further substantiated by separation on SDS-PAGE and immunoblots. Last, we attempted to identify the ubiquitin ligase(s) involved, and identified Dma1p as a trypsin-resistant protein in our mitochondrial preparations. Taken together, these data suggest a yet undefined role for the UPS in regulation of the mitochondrial matrix proteins. -- Highlights: •Mitochondrial matrix contains ubiquitinated proteins. •Ubiquitination occurs most probably in the matrix. •Dma1p is a ubiquitin ligase present in mitochondrial preparations.

Identification of wheat varieties using matrix-assisted laserdesorption/ionisation time-of-flight mass spectrometry and anartificial neural network

DEFF Research Database (Denmark)

Bloch, Helle Aagaard; Kesmir, Can; Petersen, Marianne Kjerstine

1999-01-01

of this novelmethod with respect to various experimental parameters has been tested. The results can be summarised: (i)With this approach 97% of the wheat varieties can be classified correctly with a corresponding correlationcoefficient of 1.0, (ii) The method is fast since the time of extracting gliadins from flour......A novel tool for variety identification of wheat (Triticum aestivum L.) has been developed: an artificialneural network (ANN) is used to classify the gliadin fraction analysed by matrix-assisted laserdesorption/ionisation time-of-flight mass spectrometry (MALDI-TOFMS). The robustness...... by the identity of the operator making theanalysis. This study demonstrates that a combination of an ANN and MALDI-TOFMS analysis of thegliadin fraction provides a fast and reliable tool for the variety identification of wheat. Copyright 1999 JohnWiley & Sons, Ltd....

Identification and localization of trauma-related biomarkers using matrix assisted laser desorption/ionization imaging mass spectrometry

Science.gov (United States)

Jones, Kirstin; Reilly, Matthew A.; Glickman, Randolph D.

2017-02-01

Current treatments for ocular and optic nerve trauma are largely ineffective and may have adverse side effects; therefore, new approaches are needed to understand trauma mechanisms. Identification of trauma-related biomarkers may yield insights into the molecular aspects of tissue trauma that can contribute to the development of better diagnostics and treatments. The conventional approach for protein biomarker measurement largely relies on immunoaffinity methods that typically can only be applied to analytes for which antibodies or other targeting means are available. Matrix assisted laser-assisted desorption/ionization imaging mass spectrometry (MALDI-IMS) is a specialized application of mass spectrometry that not only is well suited to the discovery of novel or unanticipated biomarkers, but also provides information about the spatial localization of biomarkers in tissue. We have been using MALDI-IMS to find traumarelated protein biomarkers in retina and optic nerve tissue from animal models subjected to ocular injury produced by either blast overpressure or mechanical torsion. Work to date by our group, using MALDI-IMS, found that the pattern of protein expression is modified in the injured ocular tissue as soon as 24 hr post-injury, compared to controls. Specific proteins may be up- or down-regulated by trauma, suggesting different tissue responses to a given injury. Ongoing work is directed at identifying the proteins affected and mapping their expression in the ocular tissue, anticipating that systematic analysis can be used to identify targets for prospective therapies for ocular trauma.

Mass spectrometry and tandem mass spectrometry of citrus limonoids.

Science.gov (United States)

Tian, Qingguo; Schwartz, Steven J

2003-10-15

Methods for atmospheric pressure chemical ionization tandem mass spectrometry (APCI-MS/MS) of citrus limonoid aglycones and electrospray ionization tandem mass spectrometry (ESI-MS/MS) of limonoid glucosides are reported. The fragmentation patterns of four citrus limonoid aglycones (limonin, nomilin, obacunone, and deacetylnomilin) and six limonoid glucosides, that is, limonin 17-beta-D-glucopyranoside (LG), nomilin 17-beta-D-glucopyranoside (NG), nomilinic acid 17-beta-D-glucopyranoside (NAG), deacetyl nomilinic acid 17-beta-D-glucopyranoside (DNAG), obacunone 17-beta-D-glucopyranoside (OG), and obacunoic acid 17-beta-D-glucopyranoside (OAG) were investigated using a quadruple mass spectrometer in low-energy collisionally activated dissociation (CAD). The four limonoid aglycones and four limonoid glucosides (LG, OG, NAG, and DNAG) were purified from citrus seeds; the other two limonoid glucosides (NG and OAG) were tentatively identified in the crude extract of grapefruit seeds by ESI mass spectrometry in both positive and negative ion analysis. Ammonium hydroxide or acetic acid was added to the mobile phase to facilitate ionization. During positive ion APCI analysis of limonoid aglycones, protonated molecular ion, [M + H]+, or adduct ion, [M + NH3 + H]-, was formed as base peaks when ammonium hydroxide was added to the mobile phase. Molecular anions or adduct ions with acetic acid ([M + HOAc - H] and [M + HOAc]-) or a deprotonated molecular ion were produced during negative ion APCI analysis of limonoid aglycones, depending on the mobile-phase modifier used. Positive ion ESI-MS of limonoid glucosides produced adduct ions of [M + H + NH3]+, [M + Na]+, and [M + K]+ when ammonium hydroxide was added to the mobile phase. After collisionally activated dissociation (CAD) of the limonoid aglycone molecular ions in negative ion APCI analysis, fragment ions indicated structural information of the precursor ions, showing the presence of methyl, carboxyl, and oxygenated ring

Lorentzian AdS, Wormholes and Holography

CERN Document Server

Arias, Raul E; Silva, Guillermo A

2011-01-01

We investigate the structure of two point functions for the QFT dual to an asymptotically Lorentzian AdS-wormhole. The bulk geometry is a solution of 5-dimensional second order Einstein Gauss Bonnet gravity and causally connects two asymptotically AdS space times. We revisit the GKPW prescription for computing two-point correlation functions for dual QFT operators O in Lorentzian signature and we propose to express the bulk fields in terms of the independent boundary values phi_0^\\pm at each of the two asymptotic AdS regions, along the way we exhibit how the ambiguity of normalizable modes in the bulk, related to initial and final states, show up in the computations. The independent boundary values are interpreted as sources for dual operators O^\\pm and we argue that, apart from the possibility of entanglement, there exists a coupling between the degrees of freedom leaving at each boundary. The AdS_(1+1) geometry is also discussed in view of its similar boundary structure. Based on the analysis, we propose a ...

Comments on Cosmic Censorship in AdS/CFT

Energy Technology Data Exchange (ETDEWEB)

Hubeny, V.

2004-04-06

Recently Hertog, Horowitz, and Maeda (HHM) (hep-th/0310054) have proposed that cosmic censorship can be violated in the AdS/CFT context. They argue that for certain initial data there is insufficient energy available to make a black hole whose horizon is big enough to cloak the singularity that forms. We have investigated this proposal in the models HHM discuss and have thus far been unable to find initial data that provably satisfy this criterion, despite our development of an improved lower bound on the size of the singular region. This is consistent with recent numerical results (hep-th/0402109). For certain initial data, the energies of our configurations are not far above the lower bound on the requisite black hole mass, and so it is possible that in the exact time development naked singularities do form. We go on to argue that the finite radius cut-off AdS5 situation discussed by HHM displays instabilities when the full 10D theory is considered. We propose an AdS3 example that may well be free of this instability.

Comments on Cosmic Censorship in AdS/CFT

Energy Technology Data Exchange (ETDEWEB)

Hubeny, Veronika E.; Liu, Xiao; Rangamani, Mukund; Shenker, Stephen

2004-03-21

Recently Hertog, Horowitz, and Maeda (HHM) (hep-th/0310054) have proposed that cosmic censorship can be violated in the AdS/CFT context. They argue that for certain initial data there is insufficient energy available to make a black hole whose horizon is big enough to cloak the singularity that forms. We have investigated this proposal in the models HHM discuss and have thus far been unable to find initial data that provably satisfy this criterion, despite our development of an improved lower bound on the size of the singular region. This is consistent with recent numerical results (hep-th/0402109). For certain initial data, the energies of our configurations are not far above the lower bound on the requisite black hole mass, and so it is possible that in the exact time development naked singularities do form. We go on to argue that the finite radius cut-off AdS_5 situation discussed by HHM displays instabilities when the full 10D theory is considered. We propose an AdS_3 example that may well be free of this instability.

Comments on cosmic censorship in AdS/CFT

International Nuclear Information System (INIS)

Hubeny, Veronika E.; Shenker, Stephen; Liu Xiao; Rangamani, Mukund

2004-01-01

Recently Hertog, Horowitz, and Maeda (HHM) have proposed that cosmic censorship can be violated in the AdS/CFT context. They argue that for certain initial data there is insufficient energy available to make a black hole whose horizon is big enough to cloak the singularity that forms. We have investigated this proposal in the models HHM discuss and have thus far been unable to find initial data that provably satisfy this criterion, despite our development of an improved lower bound on the size of the singular region. This is consistent with recent numerical results. For certain initial data, the energies of our configurations are not far above the lower bound on the requisite black hole mass, and so it is possible that in the exact time development naked singularities do form. We go on to argue that the finite radius cut-off AdS 5 situation discussed by HHM displays instabilities when the full 10D theory is considered. We propose an AdS 3 example that may well be free of this instability. (author)

Nonlinear realization of supersymmetric AdS space isometries

International Nuclear Information System (INIS)

Clark, T. E.; Love, S. T.

2006-01-01

The isometries of AdS 5 space and supersymmetric AdS 5 xS 1 space are nonlinearly realized on four-dimensional Minkowski space. The resultant effective actions in terms of the Nambu-Goldstone modes are constructed. The dilatonic mode governing the motion of the Minkowski space probe brane into the covolume of supersymmetric AdS 5 space is found to be unstable and the bulk of the AdS 5 space is unable to sustain the brane. No such instability appears in the nonsupersymmetric case

Two-body density matrix for closed s-d shell nuclei

International Nuclear Information System (INIS)

Dimitrova, S.S.; Kadrev, D.N.; Antonov, A.N.; Stoitsov, M.V.

2000-01-01

The two-body density matrix for 4 He, 16 O and 40 Ca within the Low-order approximation of the Jastrow correlation method is considered. Closed analytical expressions for the two-body density matrix, the center of mass and relative local densities and momentum distributions are presented. The effects of the short-range correlations on the two-body nuclear characteristics are investigated. (orig.)

Seismic structural response analysis using consistent mass matrices having dynamic coupling

International Nuclear Information System (INIS)

Shaw, D.E.

1977-01-01

The basis for the theoretical development of this paper is the linear matrix equations of motion for an unconstrained structure subject to support excitation. The equations are formulated in terms of absolute displacement, velocity and acceleration vectors. By means of a transformation of the absolute response vectors into displacements, velocities and accelerations relative to the support motions, the homogeneous equations become non-homogeneous and the non-homogeneous boundary conditions become homogeneous with relative displacements, velocities and accelerations being zero at support points. The forcing function or inertial loading vector is shown to consist of two parts. The first part is comprised of the mass matrix times the suppport acceleration function times a vector of structural displacements resulting from a unit vector of support displacements in the direction of excitation. This inertial loading corresponds to the classical seismic loading vector and is indeed the only loading vector for lumped-mass systems. The second part of he inertial loading vectors consists of the mass matrix times the support acceleration function times a vector of structural accelerations resulting from unit support accelerations in the direction of excitation. This term is not present in classical seismic analysis formulations and results from the presence of off-diagonal terms in the mass matrices which give rise to dynamic coupling through the mass matrix. Thus, for lumped-mass models, the classical formulation of the inertial loading vector is correct. However, if dynamic coupling terms are included through off-diagonal terms in the mass matrix, an additional inertia loading vector must be considered

Boundary conditions and dualities: vector fields in AdS/CFT

International Nuclear Information System (INIS)

Marolf, Donald; Ross, Simo F.

2006-01-01

In AdS, scalar fields with masses slightly above the Breitenlohner-Freedman bound admit a variety of possible boundary conditions which are reflected in the Lagrangian of the dual field theory. Generic small changes in the AdS boundary conditions correspond to deformations of the dual field theory by multi-trace operators. Here we extend this discussion to the case of vector gauge fields in the bulk spacetime using the results of Ishibashi and Wald [hep-th/0402184]. As in the context of scalar fields, general boundary conditions for vector fields involve multi-trace deformations which lead to renormalization-group flows. Such flows originate in ultra-violet CFTs which give new gauge/gravity dualities. At least for AdS 4 /CFT 3 , the dual of the bulk photon appears to be a propagating gauge field instead of the usual R-charge current. Applying similar reasoning to tensor fields suggests the existence of a duality between string theory on AdS 4 and a quantum gravity theory in three dimensions

Matrix-assisted laser desorption/ionization time of flight mass spectrometry peptide mass fingerprints and post source decay: a tool for the identification and analysis of phloem proteins from Cucurbita maxima Duch. separated by two-dimensional polyacrylamide gel electrophoresis.

Science.gov (United States)

Haebel, S; Kehr, J

2001-08-01

A combination of gel electrophoresis and mass spectrometry was used to analyze the soluble proteins from phloem sap of Cucurbita maxima Duch. Phloem proteins were separated using two-dimensional gel electrophoresis. Coomassie-stained spots were cut out and subjected to tryptic digestion. To identify proteins, peptide mass fingerprints were determined by matrix-assisted laser desorption/ionization time of flight (MALDI-TOF) mass spectrometry. In addition, MALDI-TOF post source decay measurements were used to obtain partial sequence information for the proteins. Results from both approaches were used for database searches. In this study, 17 proteins in the mass range 5-50 kDa were analyzed. Of these proteins six could be clearly identified, seven showed significant homologies to known plant proteins, and four were not significantly homologous to database entries. The present study suggests that the applied method is feasible for a large-scale analysis and identification of phloem proteins derived from different organs or from plants kept under various physiological conditions.

Effect of particulate matrix inhibitors on microstructure and properties of 2-D carbon-carbon composites

International Nuclear Information System (INIS)

Tlomak, P.; Takano, Shigeru; Wright, M.A.; Ju, Chien-Ping.

1991-01-01

Extended-life applications of structural carbon-carbon (C-C) composites involve multiple periods of operation in high-temperature oxidizing environments and as such require a reliable oxidation protection system (OPS). Advanced OPS's generally consist of an external ceramic coating combined with an in-depth matrix inhibitor. This work investigated the effects produced by particulate inhibitors doped on the matrix on the microstructure of 2D, PAN fiber-pitch matrix C-C's. Boron and zirconium-based particulate inhibitors were added to the matrix material prior to heat treatment. A process was developed to assure a uniform distribution of the inhibitors. Oxidation behavior of such matrix-inhibited composites was evaluated using isothermal oxidation tests. 5 refs

Non-relativistic AdS branes and Newton-Hooke superalgebra

International Nuclear Information System (INIS)

Sakaguchi, Makoto; Yoshida, Kentaroh

2006-01-01

We examine a non-relativistic limit of D-branes in AdS 5 x S 5 and M-branes in AdS 4/7 x S 7/4 . First, Newton-Hooke superalgebras for the AdS branes are derived from AdS x S superalgebras as Inoenue-Wigner contractions. It is shown that the directions along which the AdS-brane worldvolume extends are restricted by requiring that the isometry on the AdS-brane worldvolume and the Lorentz symmetry in the transverse space naturally extend to the super-isometry. We also derive Newton-Hooke superalgebras for pp-wave branes and show that the directions along which a brane worldvolume extends are restricted. Then the Wess-Zumino terms of the AdS branes are derived by using the Chevalley-Eilenberg cohomology on the super-AdS x S algebra, and the non-relativistic limit of the AdS-brane actions is considered. We show that the consistent limit is possible for the following branes: Dp (even,even) for p = 1 mod 4 and Dp (odd,odd) for p = 3 mod 4 in AdS 5 x S 5 , and M2 (0,3), M2 (2,1), M5 (1,5) and M5 (3,3) in AdS 4 x S 7 and S 4 x AdS 7 . We furthermore present non-relativistic actions for the AdS branes

Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry Analysis of Gram-Positive, Catalase-Negative Cocci Not Belonging to the Streptococcus or Enterococcus Genus and Benefits of Database Extension

DEFF Research Database (Denmark)

Christensen, Jens Jørgen; Dargis, Rimtas; Hammer, Monja

2012-01-01

Matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry with a Bruker Daltonics microflex LT system was applied to 90 well-characterized catalase-negative, Gram-positive cocci not belonging to the streptococci or enterococci. Biotyper version 2.0.43.1 software...

Measurement of the top quark mass with the matrix element method in the semileptonic decay channel at D0

Energy Technology Data Exchange (ETDEWEB)

Haefner, Petra

2008-07-31

The top quark plays a special role in the Standard Model of Particle Physics. With its enormous mass of about 170 GeV it is as heavy as a gold atom and is the only quark with a mass near the electroweak scale. Together with the W boson mass, the top quark mass allows indirect constraints on the mass of the hypothetical Higgs boson, which might hold the clue to the origin of mass. Top pair production with a semileptonic decay t anti t{yields}W{sup {+-}}W{sup -+}b anti b{yields}q anti ql{nu}b anti b is the ''golden channel'' for mass measurements, due to a large branching fraction and a relatively low background contamination compared to other decay channels. Top mass measurements based on this decay, performed with the matrix element method, have always been among the single best measurements in the world. In 2007, the top mass world average broke the 1% level of precision. Its measurement is no longer dominated by statistical but instead by systematic uncertainties. The reduction of systematic uncertainties has therefore become a key issue for further progress. This thesis introduces two new developments in the treatment of b jets. The first improvement is an optimization in the way b identification information is used. It leads to an enhanced separation between signal and background processes and reduces the statistical uncertainty by about 16%. The second improvement determines differences in the detector response and thus the energy scales of light jets and b jets. Thereby, it addresses the major source of systematic uncertainty in the latest top mass measurements. The method was validated on Monte Carlo events at the generator level, calibrated with fully simulated events, including detector simulation, and applied to D0 Run II data corresponding to 1 fb{sup -1} of integrated luminosity. Possible sources of systematic uncertainties were studied. The top mass is measured to be: m{sub t}=(169.2{+-}3.5(stat.){+-}1.0(syst.)) GeV. The

Measurement of the top quark mass with the matrix element method in the semileptonic decay channel at D0

Energy Technology Data Exchange (ETDEWEB)

Haefner, Petra [Ludwig Maximilian Univ., Munich (Germany)

2008-07-31

The top quark plays a special role in the Standard Model of Particle Physics. With its enormous mass of about 170 GeV it is as heavy as a gold atom and is the only quark with a mass near the electroweak scale. Together with theW boson mass, the top quark mass allows indirect constraints on the mass of the hypothetical Higgs boson, which might hold the clue to the origin of mass. Top pair production with a semileptonic decay t $\\bar{t}$ →W^±W^∓ b$\\bar{b}$ →q $\\bar{t}$lnb$\\bar{b}$ is the ”golden channel” for mass measurements, due to a large branching fraction and a relatively low background contamination compared to other decay channels. Top mass measurements based on this decay, performed with the matrix element method, have always been among the single best measurements in the world. In 2007, the top mass world average broke the 1% level of precision. Its measurement is no longer dominated by statistical but instead by systematic uncertainties. The reduction of systematic uncertainties has therefore become a key issue for further progress. This thesis introduces two new developments in the treatment of b jets. The first improvement is an optimization in the way b identification information is used. It leads to an enhanced separation between signal and background processes and reduces the statistical uncertainty by about 16%. The second improvement determines differences in the detector response and thus the energy scales of light jets and b jets. Thereby, it addresses the major source of systematic uncertainty in the latest top mass measurements. The method was validated on Monte Carlo events at the generator level, calibrated with fully simulated events, including detector simulation, and applied to D0 Run II data corresponding to 1 fb^-1 of integrated luminosity. Possible sources of systematic uncertainties were studied. The top mass is measured to be: m_t = (169.2±3.5(stat.)±1.0(syst.)) GeV . The

Measurement of the top quark mass with the matrix element method in the semileptonic decay channel at D0

International Nuclear Information System (INIS)

Haefner, Petra

2008-01-01

The top quark plays a special role in the Standard Model of Particle Physics. With its enormous mass of about 170 GeV it is as heavy as a gold atom and is the only quark with a mass near the electroweak scale. Together with the W boson mass, the top quark mass allows indirect constraints on the mass of the hypothetical Higgs boson, which might hold the clue to the origin of mass. Top pair production with a semileptonic decay t anti t→W ± W -+ b anti b→q anti qlνb anti b is the ''golden channel'' for mass measurements, due to a large branching fraction and a relatively low background contamination compared to other decay channels. Top mass measurements based on this decay, performed with the matrix element method, have always been among the single best measurements in the world. In 2007, the top mass world average broke the 1% level of precision. Its measurement is no longer dominated by statistical but instead by systematic uncertainties. The reduction of systematic uncertainties has therefore become a key issue for further progress. This thesis introduces two new developments in the treatment of b jets. The first improvement is an optimization in the way b identification information is used. It leads to an enhanced separation between signal and background processes and reduces the statistical uncertainty by about 16%. The second improvement determines differences in the detector response and thus the energy scales of light jets and b jets. Thereby, it addresses the major source of systematic uncertainty in the latest top mass measurements. The method was validated on Monte Carlo events at the generator level, calibrated with fully simulated events, including detector simulation, and applied to D0 Run II data corresponding to 1 fb -1 of integrated luminosity. Possible sources of systematic uncertainties were studied. The top mass is measured to be: m t =(169.2±3.5(stat.)±1.0(syst.)) GeV. The simultaneous measurement of a scaling factor for the jet energy

Metabolomic Analysis of Oxidative and Glycolytic Skeletal Muscles by Matrix-Assisted Laser Desorption/IonizationMass Spectrometric Imaging (MALDI MSI)

Science.gov (United States)

Tsai, Yu-Hsuan; Garrett, Timothy J.; Carter, Christy S.; Yost, Richard A.

2015-06-01

Skeletal muscles are composed of heterogeneous muscle fibers that have different physiological, morphological, biochemical, and histological characteristics. In this work, skeletal muscles extensor digitorum longus, soleus, and whole gastrocnemius were analyzed by matrix-assisted laser desorption/ionization mass spectrometry to characterize small molecule metabolites of oxidative and glycolytic muscle fiber types as well as to visualize biomarker localization. Multivariate data analysis such as principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA) were performed to extract significant features. Different metabolic fingerprints were observed from oxidative and glycolytic fibers. Higher abundances of biomolecules such as antioxidant anserine as well as acylcarnitines were observed in the glycolytic fibers, whereas taurine and some nucleotides were found to be localized in the oxidative fibers.