Differential synaptology of vGluT2-containing thalamostriatal afferents between the patch and matrix compartments in rats.

PubMed

Raju, Dinesh V; Shah, Deep J; Wright, Terrence M; Hall, Randy A; Smith, Yoland

2006-11-10

The striatum is divided into two compartments named the patch (or striosome) and the matrix. Although these two compartments can be differentiated by their neurochemical content or afferent and efferent projections, the synaptology of inputs to these striatal regions remains poorly characterized. By using the vesicular glutamate transporters vGluT1 and vGluT2, as markers of corticostriatal and thalamostriatal projections, respectively, we demonstrate a differential pattern of synaptic connections of these two pathways between the patch and the matrix compartments. We also demonstrate that the majority of vGluT2-immunolabeled axon terminals form axospinous synapses, suggesting that thalamic afferents, like corticostriatal inputs, terminate preferentially onto spines in the striatum. Within both compartments, more than 90% of vGluT1-containing terminals formed axospinous synapses, whereas 87% of vGluT2-positive terminals within the patch innervated dendritic spines, but only 55% did so in the matrix. To characterize further the source of thalamic inputs that could account for the increase in axodendritic synapses in the matrix, we undertook an electron microscopic analysis of the synaptology of thalamostriatal afferents to the matrix compartments from specific intralaminar, midline, relay, and associative thalamic nuclei in rats. Approximately 95% of PHA-L-labeled terminals from the central lateral, midline, mediodorsal, lateral dorsal, anteroventral, and ventral anterior/ventral lateral nuclei formed axospinous synapses, a pattern reminiscent of corticostriatal afferents but strikingly different from thalamostriatal projections arising from the parafascicular nucleus (PF), which terminated onto dendritic shafts. These findings provide the first evidence for a differential pattern of synaptic organization of thalamostriatal glutamatergic inputs to the patch and matrix compartments. Furthermore, they demonstrate that the PF is the sole source of significant axodendritic thalamic inputs to striatal projection neurons. These observations pave the way for understanding differential regulatory mechanisms of striatal outflow from the patch and matrix compartments by thalamostriatal afferents. 2006 Wiley-Liss, Inc.

Efficient Implementation of the Invariant Imbedding T-Matrix Method and the Separation of Variables Method Applied to Large Nonspherical Inhomogeneous Particles

NASA Technical Reports Server (NTRS)

Bi, Lei; Yang, Ping; Kattawar, George W.; Mishchenko, Michael I.

2012-01-01

Three terms, ''Waterman's T-matrix method'', ''extended boundary condition method (EBCM)'', and ''null field method'', have been interchangeable in the literature to indicate a method based on surface integral equations to calculate the T-matrix. Unlike the previous method, the invariant imbedding method (IIM) calculates the T-matrix by the use of a volume integral equation. In addition, the standard separation of variables method (SOV) can be applied to compute the T-matrix of a sphere centered at the origin of the coordinate system and having a maximal radius such that the sphere remains inscribed within a nonspherical particle. This study explores the feasibility of a numerical combination of the IIM and the SOV, hereafter referred to as the IIMþSOV method, for computing the single-scattering properties of nonspherical dielectric particles, which are, in general, inhomogeneous. The IIMþSOV method is shown to be capable of solving light-scattering problems for large nonspherical particles where the standard EBCM fails to converge. The IIMþSOV method is flexible and applicable to inhomogeneous particles and aggregated nonspherical particles (overlapped circumscribed spheres) representing a challenge to the standard superposition T-matrix method. The IIMþSOV computational program, developed in this study, is validated against EBCM simulated spheroid and cylinder cases with excellent numerical agreement (up to four decimal places). In addition, solutions for cylinders with large aspect ratios, inhomogeneous particles, and two-particle systems are compared with results from discrete dipole approximation (DDA) computations, and comparisons with the improved geometric-optics method (IGOM) are found to be quite encouraging.

High-dimensional statistical inference: From vector to matrix

NASA Astrophysics Data System (ADS)

Zhang, Anru

Statistical inference for sparse signals or low-rank matrices in high-dimensional settings is of significant interest in a range of contemporary applications. It has attracted significant recent attention in many fields including statistics, applied mathematics and electrical engineering. In this thesis, we consider several problems in including sparse signal recovery (compressed sensing under restricted isometry) and low-rank matrix recovery (matrix recovery via rank-one projections and structured matrix completion). The first part of the thesis discusses compressed sensing and affine rank minimization in both noiseless and noisy cases and establishes sharp restricted isometry conditions for sparse signal and low-rank matrix recovery. The analysis relies on a key technical tool which represents points in a polytope by convex combinations of sparse vectors. The technique is elementary while leads to sharp results. It is shown that, in compressed sensing, delta kA < 1/3, deltak A+ thetak,kA < 1, or deltatkA < √( t - 1)/t for any given constant t ≥ 4/3 guarantee the exact recovery of all k sparse signals in the noiseless case through the constrained ℓ1 minimization, and similarly in affine rank minimization delta rM < 1/3, deltar M + thetar, rM < 1, or deltatrM< √( t - 1)/t ensure the exact reconstruction of all matrices with rank at most r in the noiseless case via the constrained nuclear norm minimization. Moreover, for any epsilon > 0, delta kA < 1/3 + epsilon, deltak A + thetak,kA < 1 + epsilon, or deltatkA< √(t - 1) / t + epsilon are not sufficient to guarantee the exact recovery of all k-sparse signals for large k. Similar result also holds for matrix recovery. In addition, the conditions delta kA<1/3, deltak A+ thetak,kA<1, delta tkA < √(t - 1)/t and deltarM<1/3, delta rM+ thetar,rM<1, delta trM< √(t - 1)/ t are also shown to be sufficient respectively for stable recovery of approximately sparse signals and low-rank matrices in the noisy case. For the second part of the thesis, we introduce a rank-one projection model for low-rank matrix recovery and propose a constrained nuclear norm minimization method for stable recovery of low-rank matrices in the noisy case. The procedure is adaptive to the rank and robust against small perturbations. Both upper and lower bounds for the estimation accuracy under the Frobenius norm loss are obtained. The proposed estimator is shown to be rate-optimal under certain conditions. The estimator is easy to implement via convex programming and performs well numerically. The techniques and main results developed in the chapter also have implications to other related statistical problems. An application to estimation of spiked covariance matrices from one-dimensional random projections is considered. The results demonstrate that it is still possible to accurately estimate the covariance matrix of a high-dimensional distribution based only on one-dimensional projections. For the third part of the thesis, we consider another setting of low-rank matrix completion. Current literature on matrix completion focuses primarily on independent sampling models under which the individual observed entries are sampled independently. Motivated by applications in genomic data integration, we propose a new framework of structured matrix completion (SMC) to treat structured missingness by design. Specifically, our proposed method aims at efficient matrix recovery when a subset of the rows and columns of an approximately low-rank matrix are observed. We provide theoretical justification for the proposed SMC method and derive lower bound for the estimation errors, which together establish the optimal rate of recovery over certain classes of approximately low-rank matrices. Simulation studies show that the method performs well in finite sample under a variety of configurations. The method is applied to integrate several ovarian cancer genomic studies with different extent of genomic measurements, which enables us to construct more accurate prediction rules for ovarian cancer survival.

Weak Measurement and Quantum Smoothing of a Superconducting Qubit

NASA Astrophysics Data System (ADS)

Tan, Dian

In quantum mechanics, the measurement outcome of an observable in a quantum system is intrinsically random, yielding a probability distribution. The state of the quantum system can be described by a density matrix rho(t), which depends on the information accumulated until time t, and represents our knowledge about the system. The density matrix rho(t) gives probabilities for the outcomes of measurements at time t. Further probing of the quantum system allows us to refine our prediction in hindsight. In this thesis, we experimentally examine a quantum smoothing theory in a superconducting qubit by introducing an auxiliary matrix E(t) which is conditioned on information obtained from time t to a final time T. With the complete information before and after time t, the pair of matrices [rho(t), E(t)] can be used to make smoothed predictions for the measurement outcome at time t. We apply the quantum smoothing theory in the case of continuous weak measurement unveiling the retrodicted quantum trajectories and weak values. In the case of strong projective measurement, while the density matrix rho(t) with only diagonal elements in a given basis |n〉 may be treated as a classical mixture, we demonstrate a failure of this classical mixture description in determining the smoothed probabilities for the measurement outcome at time t with both diagonal rho(t) and diagonal E(t). We study the correlations between quantum states and weak measurement signals and examine aspects of the time symmetry of continuous quantum measurement. We also extend our study of quantum smoothing theory to the case of resonance fluorescence of a superconducting qubit with homodyne measurement and observe some interesting effects such as the modification of the excited state probabilities, weak values, and evolution of the predicted and retrodicted trajectories.

Comprehensive Thematic T-Matrix Reference Database: A 2014-2015 Update

NASA Technical Reports Server (NTRS)

Mishchenko, Michael I.; Zakharova, Nadezhda; Khlebtsov, Nikolai G.; Videen, Gorden; Wriedt, Thomas

2015-01-01

The T-matrix method is one of the most versatile and efficient direct computer solvers of the macroscopic Maxwell equations and is widely used for the computation of electromagnetic scattering by single and composite particles, discrete random media, and particles in the vicinity of an interface separating two half-spaces with different refractive indices. This paper is the seventh update to the comprehensive thematic database of peer-reviewed T-matrix publications initiated by us in 2004 and includes relevant publications that have appeared since 2013. It also lists a number of earlier publications overlooked previously.

Optical factors determined by the T-matrix method in turbidity measurement of absolute coagulation rate constants.

PubMed

Xu, Shenghua; Liu, Jie; Sun, Zhiwei

2006-12-01

Turbidity measurement for the absolute coagulation rate constants of suspensions has been extensively adopted because of its simplicity and easy implementation. A key factor in deriving the rate constant from experimental data is how to theoretically evaluate the so-called optical factor involved in calculating the extinction cross section of doublets formed during aggregation. In a previous paper, we have shown that compared with other theoretical approaches, the T-matrix method provides a robust solution to this problem and is effective in extending the applicability range of the turbidity methodology, as well as increasing measurement accuracy. This paper will provide a more comprehensive discussion of the physical insight for using the T-matrix method in turbidity measurement and associated technical details. In particular, the importance of ensuring the correct value for the refractive indices for colloidal particles and the surrounding medium used in the calculation is addressed, because the indices generally vary with the wavelength of the incident light. The comparison of calculated results with experiments shows that the T-matrix method can correctly calculate optical factors even for large particles, whereas other existing theories cannot. In addition, the data of the optical factor calculated by the T-matrix method for a range of particle radii and incident light wavelengths are listed.

Data-Driven Learning of Q-Matrix

PubMed Central

Liu, Jingchen; Xu, Gongjun; Ying, Zhiliang

2013-01-01

The recent surge of interests in cognitive assessment has led to developments of novel statistical models for diagnostic classification. Central to many such models is the well-known Q-matrix, which specifies the item–attribute relationships. This article proposes a data-driven approach to identification of the Q-matrix and estimation of related model parameters. A key ingredient is a flexible T-matrix that relates the Q-matrix to response patterns. The flexibility of the T-matrix allows the construction of a natural criterion function as well as a computationally amenable algorithm. Simulations results are presented to demonstrate usefulness and applicability of the proposed method. Extension to handling of the Q-matrix with partial information is presented. The proposed method also provides a platform on which important statistical issues, such as hypothesis testing and model selection, may be formally addressed. PMID:23926363

Extending the range of real time density matrix renormalization group simulations

NASA Astrophysics Data System (ADS)

Kennes, D. M.; Karrasch, C.

2016-03-01

We discuss a few simple modifications to time-dependent density matrix renormalization group (DMRG) algorithms which allow to access larger time scales. We specifically aim at beginners and present practical aspects of how to implement these modifications within any standard matrix product state (MPS) based formulation of the method. Most importantly, we show how to 'combine' the Schrödinger and Heisenberg time evolutions of arbitrary pure states | ψ 〉 and operators A in the evaluation of 〈A〉ψ(t) = 〈 ψ | A(t) | ψ 〉 . This includes quantum quenches. The generalization to (non-)thermal mixed state dynamics 〈A〉ρ(t) =Tr [ ρA(t) ] induced by an initial density matrix ρ is straightforward. In the context of linear response (ground state or finite temperature T > 0) correlation functions, one can extend the simulation time by a factor of two by 'exploiting time translation invariance', which is efficiently implementable within MPS DMRG. We present a simple analytic argument for why a recently-introduced disentangler succeeds in reducing the effort of time-dependent simulations at T > 0. Finally, we advocate the python programming language as an elegant option for beginners to set up a DMRG code.

The open quantum Brownian motions

NASA Astrophysics Data System (ADS)

Bauer, Michel; Bernard, Denis; Tilloy, Antoine

2014-09-01

Using quantum parallelism on random walks as the original seed, we introduce new quantum stochastic processes, the open quantum Brownian motions. They describe the behaviors of quantum walkers—with internal degrees of freedom which serve as random gyroscopes—interacting with a series of probes which serve as quantum coins. These processes may also be viewed as the scaling limit of open quantum random walks and we develop this approach along three different lines: the quantum trajectory, the quantum dynamical map and the quantum stochastic differential equation. We also present a study of the simplest case, with a two level system as an internal gyroscope, illustrating the interplay between the ballistic and diffusive behaviors at work in these processes. Notation H_z : orbital (walker) Hilbert space, {C}^{{Z}} in the discrete, L^2({R}) in the continuum H_c : internal spin (or gyroscope) Hilbert space H_sys=H_z\\otimesH_c : system Hilbert space H_p : probe (or quantum coin) Hilbert space, H_p={C}^2 \\rho^tot_t : density matrix for the total system (walker + internal spin + quantum coins) \\bar \\rho_t : reduced density matrix on H_sys : \\bar\\rho_t=\\int dxdy\\, \\bar\\rho_t(x,y)\\otimes | x \\rangle _z\\langle y | \\hat \\rho_t : system density matrix in a quantum trajectory: \\hat\\rho_t=\\int dxdy\\, \\hat\\rho_t(x,y)\\otimes | x \\rangle _z\\langle y | . If diagonal and localized in position: \\hat \\rho_t=\\rho_t\\otimes| X_t \\rangle _z\\langle X_t | ρt: internal density matrix in a simple quantum trajectory Xt: walker position in a simple quantum trajectory Bt: normalized Brownian motion ξt, \\xi_t^\\dagger : quantum noises

The large-N Yang-Mills S matrix is ultraviolet finite, but the large-N QCD S matrix is only renormalizable

NASA Astrophysics Data System (ADS)

Bochicchio, Marco

2017-03-01

Yang-Mills (YM) theory and QCD are known to be renormalizable, but not ultraviolet (UV) finite, order by order, in perturbation theory. It is a fundamental question whether YM theory or QCD is UV finite, or only renormalizable, order by order, in the large-N 't Hooft or Veneziano expansions. We demonstrate that the renormalization group (RG) and asymptotic freedom imply that in 't Hooft large-N expansion the S matrix in YM theory is UV finite, while in both 't Hooft and Veneziano large-N expansions, the S matrix in confining massless QCD is renormalizable but not UV finite. By the same argument, the large-N N =1 supersymmetry (SUSY) YM S matrix is UV finite as well. Besides, we demonstrate that, in both 't Hooft and Veneziano large-N expansions, the correlators of local gauge-invariant operators, as opposed to the S matrix, are renormalizable but, in general, not UV finite, either in YM theory and N =1 SUSY YM theory or a fortiori in massless QCD. Moreover, we compute explicitly the counterterms that arise from renormalizing the 't Hooft and Veneziano expansions by deriving in confining massless QCD-like theories a low-energy theorem of the Novikov-Shifman-Vainshtein-Zakharov type that relates the log derivative with respect to the gauge coupling of a k -point correlator, or the log derivative with respect to the RG-invariant scale, to a (k +1 )-point correlator with the insertion of Tr F2 at zero momentum. Finally, we argue that similar results hold in the large-N limit of a vast class of confining massive QCD-like theories, provided a renormalization scheme exists—as, for example, MS ¯ —in which the beta function is not dependent on the masses. Specifically, in both 't Hooft and Veneziano large-N expansions, the S matrix in confining massive QCD and massive N =1 SUSY QCD is renormalizable but not UV finite.

Field Trial Data Analysis and Testing (FiTAT) Tool

DTIC Science & Technology

2011-10-01

amplitude/phase pour chaque antenne du réseau) contenu dans les données acquises pourrait être faite par FiTAT et utilisé dans PAASoM pour déterminer...identity matrix, k is the loop gain, φ is the correlation matrix of the incident signals and T = [1 0 . . . 0]T . The length of vector T is equal to the

Comprehensive Thematic T-Matrix Reference Database: A 2015-2017 Update

NASA Technical Reports Server (NTRS)

Mishchenko, Michael I.; Zakharova, Nadezhda; Khlebtsov, Nikolai G.; Videen, Gorden; Wriedt, Thomas

2017-01-01

The T-matrix method pioneered by Peter C. Waterman is one of the most versatile and efficient numerically exact computer solvers of the time-harmonic macroscopic Maxwell equations. It is widely used for the computation of electromagnetic scattering by single and composite particles, discrete random media, periodic structures (including metamaterials), and particles in the vicinity of plane or rough interfaces separating media with different refractive indices. This paper is the eighth update to the comprehensive thematic database of peer-reviewed T-matrix publications initiated in 2004 and lists relevant publications that have appeared since 2015. It also references a small number of earlier publications overlooked previously.

Comprehensive thematic T-matrix reference database: A 2015-2017 update

NASA Astrophysics Data System (ADS)

Mishchenko, Michael I.; Zakharova, Nadezhda T.; Khlebtsov, Nikolai G.; Videen, Gorden; Wriedt, Thomas

2017-11-01

The T-matrix method pioneered by Peter C. Waterman is one of the most versatile and efficient numerically exact computer solvers of the time-harmonic macroscopic Maxwell equations. It is widely used for the computation of electromagnetic scattering by single and composite particles, discrete random media, periodic structures (including metamaterials), and particles in the vicinity of plane or rough interfaces separating media with different refractive indices. This paper is the eighth update to the comprehensive thematic database of peer-reviewed T-matrix publications initiated in 2004 and lists relevant publications that have appeared since 2015. It also references a small number of earlier publications overlooked previously.

The time-dependent density matrix renormalisation group method

NASA Astrophysics Data System (ADS)

Ma, Haibo; Luo, Zhen; Yao, Yao

2018-04-01

Substantial progress of the time-dependent density matrix renormalisation group (t-DMRG) method in the recent 15 years is reviewed in this paper. By integrating the time evolution with the sweep procedures in density matrix renormalisation group (DMRG), t-DMRG provides an efficient tool for real-time simulations of the quantum dynamics for one-dimensional (1D) or quasi-1D strongly correlated systems with a large number of degrees of freedom. In the illustrative applications, the t-DMRG approach is applied to investigate the nonadiabatic processes in realistic chemical systems, including exciton dissociation and triplet fission in polymers and molecular aggregates as well as internal conversion in pyrazine molecule.

Fiber study involving a polyimide matrix

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cano, R.J.; Rommel, M.; Hinkley, J.A.

1996-12-31

Mechanical properties are presented for eight different intermediate modulus carbon fiber/ polyimide matrix composites. Two unsized carbon fibers (Thornel T650-42 and Hercules IM9) and two sized carbon fibers (high temperature sized Thornel T650-42 HTS and epoxy sized Toray T1000) were prepregged on the NASA LaRC Multipurpose Tape Machine using the NASA LaRC developed polyimide resin matrix, LaRC{trademark}-PETI-5, and the DuPont developed Avitnid{reg_sign} R1-16. Composite panels fabricated from these prepregs were evaluated to determine their mechanical properties. The data show the effects of using sized fibers on the processing and mechanical properties of polyimide composites.

Coil-to-coil physiological noise correlations and their impact on fMRI time-series SNR

PubMed Central

Triantafyllou, C.; Polimeni, J. R.; Keil, B.; Wald, L. L.

2017-01-01

Purpose Physiological nuisance fluctuations (“physiological noise”) are a major contribution to the time-series Signal to Noise Ratio (tSNR) of functional imaging. While thermal noise correlations between array coil elements have a well-characterized effect on the image Signal to Noise Ratio (SNR0), the element-to-element covariance matrix of the time-series fluctuations has not yet been analyzed. We examine this effect with a goal of ultimately improving the combination of multichannel array data. Theory and Methods We extend the theoretical relationship between tSNR and SNR0 to include a time-series noise covariance matrix Ψt, distinct from the thermal noise covariance matrix Ψ0, and compare its structure to Ψ0 and the signal coupling matrix SSH formed from the signal intensity vectors S. Results Inclusion of the measured time-series noise covariance matrix into the model relating tSNR and SNR0 improves the fit of experimental multichannel data and is shown to be distinct from Ψ0 or SSH. Conclusion Time-series noise covariances in array coils are found to differ from Ψ0 and more surprisingly, from the signal coupling matrix SSH. Correct characterization of the time-series noise has implications for the analysis of time-series data and for improving the coil element combination process. PMID:26756964

Magnetic resonance microscopy for assessment of morphological changes in hydrating hydroxypropylmethylcellulose matrix tablets in situ-is it possible to detect phenomena related to drug dissolution within the hydrated matrices?

PubMed

Kulinowski, Piotr; Młynarczyk, Anna; Jasiński, Krzysztof; Talik, Przemysław; Gruwel, Marco L H; Tomanek, Bogusław; Węglarz, Władysław P; Dorożyński, Przemysław

2014-09-01

So far, the hydrated part of the HPMC matrix has commonly been denoted as a "gel" or "pseudogel" layer. No MRI-based results have been published regarding observation of internal phenomena related to drug dissolution inside swelling polymeric matrices during hydration. The purpose of the study was to detect such phenomena. Multiparametric, spatially and temporally resolved T2 MR relaxometry, in situ, was applied to study formation of the hydration progress in HPMC matrix tablets loaded with L-dopa and ketoprofen using a 11.7 T MRI system. Two spin-echo based pulse sequences were used, one of them specifically designed to study short T2 signals. Two components in the T2 decay envelope were estimated and spatial distributions of their parameters, i.e. amplitudes and T2 values, were obtained. Based on the data, different region formation patterns (i.e. multilayer structure) were registered depending on drug presence and solubility. Inside the matrix with incorporated sparingly soluble drug a specific layer formation due to drug dissolution was detected, whereas a matrix with very slightly soluble drug does not form distinct external "gel-like" layer. We have introduced a new paradigm in the characterization of hydrating matrices using (1)H MRI methods. It reflects molecular mobility and concentration of water inside the hydrated matrix. For the first time, drug dissolution related phenomena, i.e. particular front and region formation, were observed by MRI methods.

Cytotoxic T Lymphocyte Trafficking and Survival in an Augmented Fibrin Matrix Carrier

PubMed Central

Zou, Zhaoxia; Denny, Erin; Brown, Christine E.; Jensen, Michael C.; Li, Gang; Fujii, Tatsuhiro; Neman, Josh; Jandial, Rahul; Chen, Mike

2012-01-01

Cell-based therapies have intriguing potential for the treatment of a variety of neurological disorders. One such example is genetically engineered cytotoxic T lymphocytes (CTLs) that are being investigated in brain tumor clinical trials. The development of methods for CTL delivery is critical to their use in the laboratory and clinical setting. In our study, we determined whether CTLs can migrate through fibrin matrices and if their migration, survival, and function could be modulated by adding chemokines to the matrix. Our results indicated that CTLs can freely migrate through fibrin matrices. As expected, the addition of the monocyte chemotactic protein-1 (MCP-1), also known as chemokine C-C motif ligand 2 (CCL2), to the surrounding media increased egress of the CTLs out of the fibrin clot. Interleukin (IL) -2 and/or IL-15 embedded in the matrix enhanced T cell survival and further promoted T cell migration. The interleukin-13 receptor alpha 2 specific (IL-13R alpha2) T cells that traveled out of the fibrin clot retained the capacity to kill U251 glioma cells. In summary, CTLs can survive and migrate robustly in fibrin matrices. These processes can be influenced by modification of matrix constituents. We conclude that fibrin matrices may be suitable T cell carriers and can be used to facilitate understanding of T cell interaction with the surrounding microenvironment. PMID:22496835

Cytotoxic T lymphocyte trafficking and survival in an augmented fibrin matrix carrier.

PubMed

Zou, Zhaoxia; Denny, Erin; Brown, Christine E; Jensen, Michael C; Li, Gang; Fujii, Tatsuhiro; Neman, Josh; Jandial, Rahul; Chen, Mike

2012-01-01

Cell-based therapies have intriguing potential for the treatment of a variety of neurological disorders. One such example is genetically engineered cytotoxic T lymphocytes (CTLs) that are being investigated in brain tumor clinical trials. The development of methods for CTL delivery is critical to their use in the laboratory and clinical setting. In our study, we determined whether CTLs can migrate through fibrin matrices and if their migration, survival, and function could be modulated by adding chemokines to the matrix. Our results indicated that CTLs can freely migrate through fibrin matrices. As expected, the addition of the monocyte chemotactic protein-1 (MCP-1), also known as chemokine C-C motif ligand 2 (CCL2), to the surrounding media increased egress of the CTLs out of the fibrin clot. Interleukin (IL) -2 and/or IL-15 embedded in the matrix enhanced T cell survival and further promoted T cell migration. The interleukin-13 receptor alpha 2 specific (IL-13R alpha2) T cells that traveled out of the fibrin clot retained the capacity to kill U251 glioma cells. In summary, CTLs can survive and migrate robustly in fibrin matrices. These processes can be influenced by modification of matrix constituents. We conclude that fibrin matrices may be suitable T cell carriers and can be used to facilitate understanding of T cell interaction with the surrounding microenvironment.

Corrosion of Graphite Aluminum Metal Matrix Composites

DTIC Science & Technology

1991-02-01

cathodic protection of G/AI MMCs resulted in overprotection 13. Overprotection resulted from a local increase in pH near cathodic sites during...34Cathodic Overprotection of SiC/6061-T6 and G/6061- T6 Aluminum Alloy Metal Matrix Composites," Scripta Metallurgica, 22 (1988) 413-418. 14. R

Comprehensive Thematic T-matrix Reference Database: a 2013-2014 Update

NASA Technical Reports Server (NTRS)

Mishchenko, Michael I.; Zakharova, Nadezhda T.; Khlebtsov, Nikolai G.; Wriedt, Thomas; Videen, Gorden

2014-01-01

This paper is the sixth update to the comprehensive thematic database of peer-reviewedT-matrix publications initiated by us in 2004 and includes relevant publications that have appeared since 2013. It also lists several earlier publications not incorporated in the original database and previous updates.

Magnetic resonance microscopy for assessment of morphological changes in hydrating hydroxypropylmethyl cellulose matrix tablets in situ.

PubMed

Kulinowski, Piotr; Młynarczyk, Anna; Dorożyński, Przemysław; Jasiński, Krzysztof; Gruwel, Marco L H; Tomanek, Bogusław; Węglarz, Władysław P

2012-12-01

To resolve contradictions found in morphology of hydrating hydroxypropylmethyl cellulose (HPMC) matrix as studied using Magnetic Resonance Imaging (MRI) techniques. Until now, two approaches were used in the literature: either two or three regions that differ in physicochemical properties were identified. Multiparametric, spatially and temporally resolved T(2) MR relaxometry in situ was applied to study the hydration progress in HPMC matrix tablets using a 11.7 T MRI system. Two spin-echo based pulse sequences-one of them designed to specifically study short T(2) signals-were used. Two components in the T(2) decay envelope were estimated and spatial distributions of their parameters, i.e. amplitudes and T(2) values, were obtained. Based on the data, five different regions and their temporal evolution were identified: dry glassy, hydrated solid like, two interface layers and gel layer. The regions were found to be separated by four evolving fronts identified as penetration, full hydration, total gelification and apparent erosion. The MRI results showed morphological details of the hydrating HPMC matrices matching compound theoretical models. The proposed method will allow for adequate evaluation of controlled release polymeric matrix systems loaded with drug substances of different solubility.

Coulomb matrix elements in multi-orbital Hubbard models.

PubMed

Bünemann, Jörg; Gebhard, Florian

2017-04-26

Coulomb matrix elements are needed in all studies in solid-state theory that are based on Hubbard-type multi-orbital models. Due to symmetries, the matrix elements are not independent. We determine a set of independent Coulomb parameters for a d-shell and an f-shell and all point groups with up to 16 elements (O h , O, T d , T h , D 6h , and D 4h ). Furthermore, we express all other matrix elements as a function of the independent Coulomb parameters. Apart from the solution of the general point-group problem we investigate in detail the spherical approximation and first-order corrections to the spherical approximation.

The Baker-Akhiezer Function and Factorization of the Chebotarev-Khrapkov Matrix

NASA Astrophysics Data System (ADS)

Antipov, Yuri A.

2014-10-01

A new technique is proposed for the solution of the Riemann-Hilbert problem with the Chebotarev-Khrapkov matrix coefficient {G(t) = α1(t)I + α2(t)Q(t)} , {α1(t), α2(t) in H(L)} , I = diag{1, 1}, Q(t) is a {2×2} zero-trace polynomial matrix. This problem has numerous applications in elasticity and diffraction theory. The main feature of the method is the removal of essential singularities of the solution to the associated homogeneous scalar Riemann-Hilbert problem on the hyperelliptic surface of an algebraic function by means of the Baker-Akhiezer function. The consequent application of this function for the derivation of the general solution to the vector Riemann-Hilbert problem requires the finding of the {ρ} zeros of the Baker-Akhiezer function ({ρ} is the genus of the surface). These zeros are recovered through the solution to the associated Jacobi problem of inversion of abelian integrals or, equivalently, the determination of the zeros of the associated degree-{ρ} polynomial and solution of a certain linear algebraic system of {ρ} equations.

Linearized T-Matrix and Mie Scattering Computations

NASA Technical Reports Server (NTRS)

Spurr, R.; Wang, J.; Zeng, J.; Mishchenko, M. I.

2011-01-01

We present a new linearization of T-Matrix and Mie computations for light scattering by non-spherical and spherical particles, respectively. In addition to the usual extinction and scattering cross-sections and the scattering matrix outputs, the linearized models will generate analytical derivatives of these optical properties with respect to the real and imaginary parts of the particle refractive index, and (for non-spherical scatterers) with respect to the ''shape'' parameter (the spheroid aspect ratio, cylinder diameter/height ratio, Chebyshev particle deformation factor). These derivatives are based on the essential linearity of Maxwell's theory. Analytical derivatives are also available for polydisperse particle size distribution parameters such as the mode radius. The T-matrix formulation is based on the NASA Goddard Institute for Space Studies FORTRAN 77 code developed in the 1990s. The linearized scattering codes presented here are in FORTRAN 90 and will be made publicly available.

Modifying a numerical algorithm for solving the matrix equation X + AX T B = C

NASA Astrophysics Data System (ADS)

Vorontsov, Yu. O.

2013-06-01

Certain modifications are proposed for a numerical algorithm solving the matrix equation X + AX T B = C. By keeping the intermediate results in storage and repeatedly using them, it is possible to reduce the total complexity of the algorithm from O( n 4) to O( n 3) arithmetic operations.

Coil-to-coil physiological noise correlations and their impact on functional MRI time-series signal-to-noise ratio.

PubMed

Triantafyllou, Christina; Polimeni, Jonathan R; Keil, Boris; Wald, Lawrence L

2016-12-01

Physiological nuisance fluctuations ("physiological noise") are a major contribution to the time-series signal-to-noise ratio (tSNR) of functional imaging. While thermal noise correlations between array coil elements have a well-characterized effect on the image Signal to Noise Ratio (SNR 0 ), the element-to-element covariance matrix of the time-series fluctuations has not yet been analyzed. We examine this effect with a goal of ultimately improving the combination of multichannel array data. We extend the theoretical relationship between tSNR and SNR 0 to include a time-series noise covariance matrix Ψ t , distinct from the thermal noise covariance matrix Ψ 0 , and compare its structure to Ψ 0 and the signal coupling matrix SS H formed from the signal intensity vectors S. Inclusion of the measured time-series noise covariance matrix into the model relating tSNR and SNR 0 improves the fit of experimental multichannel data and is shown to be distinct from Ψ 0 or SS H . Time-series noise covariances in array coils are found to differ from Ψ 0 and more surprisingly, from the signal coupling matrix SS H . Correct characterization of the time-series noise has implications for the analysis of time-series data and for improving the coil element combination process. Magn Reson Med 76:1708-1719, 2016. © 2016 International Society for Magnetic Resonance in Medicine. © 2016 International Society for Magnetic Resonance in Medicine.

T Lymphocytes Influence the Mineralization Process of Bone

PubMed Central

El Khassawna, Thaqif; Serra, Alessandro; Bucher, Christian H.; Petersen, Ansgar; Schlundt, Claudia; Könnecke, Ireen; Malhan, Deeksha; Wendler, Sebastian; Schell, Hanna; Volk, Hans-Dieter; Schmidt-Bleek, Katharina; Duda, Georg N.

2017-01-01

Bone is a unique organ able to regenerate itself after injuries. This regeneration requires the local interplay between different biological systems such as inflammation and matrix formation. Structural reconstitution is initiated by an inflammatory response orchestrated by the host immune system. However, the individual role of T cells and B cells in regeneration and their relationship to bone tissue reconstitution remain unknown. Comparing bone and fracture healing in animals with and without mature T and B cells revealed the essential role of these immune cells in determining the tissue mineralization and thus the bone quality. Bone without mature T and B cells is stiffer when compared to wild-type bone thus lacking the elasticity that helps to absorb forces, thus preventing fractures. In-depth analysis showed dysregulations in collagen deposition and osteoblast distribution upon lack of mature T and B cells. These changes in matrix deposition have been correlated with T cells rather than B cells within this study. This work presents, for the first time, a direct link between immune cells and matrix formation during bone healing after fracture. It illustrates specifically the role of T cells in the collagen organization process and the lack thereof in the absence of T cells. PMID:28596766

Consistent force field modeling of matrix isolated molecules. V. Minimum energy path potential to the conformer conversion of 1,2-difluoroethane: Ar 364, ab initio calculation of electric multipole moments and electric polarization contribution to the conversion barrier

NASA Astrophysics Data System (ADS)

Gunde, R.; Ha, T.-K.; Günthard, H. H.

1990-08-01

In this paper results of consistent force field modeling (CFF) of the potential function to conversion of the gauche (g) to the trans (t) conformer of 1,2-difluoroethane (DFE) isolated in an argon matrix will be reported. Starting point are locally stable configurations gDFE:Ar 364 (defect GH1) and tDFE:Ar 364 (TH1) obtained in previous work from CFF modeling of a cube shaped Ar 364 fragment containing one DFE molecule in its center. Using the dihedral angle of DFE as an independent parameter the minimum energy path of the conversion process gDFE:Ar 364→tDFE:Ar 364 will be determined by CFF energy minimization. Determination of the minimum energy path is found to require large numbers of energy minimization steps and to lead to a rather complicated motion of the molecule with respect to the crystal fragment. Surprisingly the molecule-matrix interactions lead to a reduction of the g-t barrier by ≈500 cal/mol and to a stabilization of the trans species by ≈500 cal/mol. This finding is a consequence of a delicate interplay of matrix-molecule and matrix-matrix interactions. Calculation of the electric polarization energy (induced dipole-first-order polarization approximation) is based on extended ab initio calculations of dipole and quadrupole moments and a bond polarizability estimate of the first-order polarizability of DFE as a function of the internal rotation angle, on Fourier expansion of multipole components and use of symmetry for reduction of the order of the linear system defining the (self-consistent) induced dipole moments of all Ar atoms. Electric polarization is found to alter the potential function of the conversion process in a profound way: the g-t barrier and the t-g energy difference are increased to ≈3000 cal/mol and to ≈1500 cal/mol respectively (≈2500 and ≈530 cal/mol respectively for free DFE). Further applications of the technique developed in this work to related problems of matrix isolated molecules, e.g., vibrational matrix shifts will be discussed.

Studies on the compressibility of wax matrix granules of acetaminophen and their admixtures with various tableting bases.

PubMed

Uhumwangho, M U; Okor, R S

2006-04-01

Matrix granules of acetaminophen have been formed by a melt granulation process whereby the acetaminophen powder was triturated with the melted wax--goat wax, glyceryl monostearate or carnuba wax. The compressibility of the matrix granules and their admixture, with diluent granules (lactose, alpha-cellulose or microcrystalline cellulose) was investigated. The granules were compressed to tablets at a constant load (30 arbitrary units on the load scale) of a manesty single punch machine. Resulting tablets were evaluated for tensile strength (T) and disintegration times (DT). Granule flow was determined by measuring their angle of repose when allowed to fall freely on a level surface. Matrix granules prepared by melt granulation with goat wax or glyceryl monostearate were too sticky and therefore did not flow at all. They were also poorly compressible (T values = 0.20MN/m2). Inclusion of the diluent remarkably improved granule flow property and compressibility. The T values of the tablets (measure of compressibility) increased from about 0.24 to 0.65 MN/m2 during increase in diluent (lactose) content from 20 to 80 %w/w. Microcrystalline cellulose and alpha-cellulose were more effective than lactose in promoting compressibility of the granules. By contrast the matrix granules formed with carnuba wax were free flowing (angle of repose, 18.60). Addition of the diluent further improved flowability slightly. The matrix granules (without a diluent) were readily compressible (T value, 1.79MN/m2). Addition of the diluent (80%w/w) reduced T values (MN/m2) slightly to 1.32 (lactose), 1.48 (alpha-cellulose) and 1.74 (microcrystalline cellulose). Tablets of the matrix granules only, disintegrated rapidly within 3 minutes. DT was further reduced to <30 s by addition of any of the diluents. The indication is that the inclusion of the diluents studied can be used to improve the compressibility of the otherwise poorly compressible matrix granules. Based on the flowability, compressibility, and disintegration data, carnuba wax proved most promising in the melt granulation of the test drug for sustained release applications.

Obesity/Type II diabetes alters macrophage polarization resulting in a fibrotic tendon healing response

PubMed Central

Ackerman, Jessica E.; Geary, Michael B.; Orner, Caitlin A.; Bawany, Fatima

2017-01-01

Type II Diabetes (T2DM) dramatically impairs the tendon healing response, resulting in decreased collagen organization and mechanics relative to non-diabetic tendons. Despite this burden, there remains a paucity of information regarding the mechanisms that govern impaired healing of diabetic tendons. Mice were placed on either a high fat diet (T2DM) or low fat diet (lean) and underwent flexor tendon transection and repair surgery. Healing was assessed via mechanical testing, histology and changes in gene expression associated with collagen synthesis, matrix remodeling, and macrophage polarization. Obese/diabetic tendons healed with increased scar formation and impaired mechanical properties. Consistent with this, prolonged and excess expression of extracellular matrix (ECM) components were observed in obese/T2DM tendons. Macrophages are involved in both inflammatory and matrix deposition processes during healing. Obese/T2DM tendons healed with increased expression of markers of pro-inflammatory M1 macrophages, and elevated and prolonged expression of M2 macrophages markers that are involved in ECM deposition. Here we demonstrate that tendons from obese/diabetic mice heal with increased scar formation and increased M2 polarization, identifying excess M2 macrophage activity and matrix synthesis as a potential mechanism of the fibrotic healing phenotype observed in T2DM tendons, and as such a potential target to improve tendon healing in T2DM. PMID:28686669

Coherent Microwave Scattering Model of Marsh Grass

NASA Astrophysics Data System (ADS)

Duan, Xueyang; Jones, Cathleen E.

2017-12-01

In this work, we developed an electromagnetic scattering model to analyze radar scattering from tall-grass-covered lands such as wetlands and marshes. The model adopts the generalized iterative extended boundary condition method (GIEBCM) algorithm, previously developed for buried cylindrical media such as vegetation roots, to simulate the scattering from the grass layer. The major challenge of applying GIEBCM to tall grass is the extremely time-consuming iteration among the large number of short subcylinders building up the grass. To overcome this issue, we extended the GIEBCM to multilevel GIEBCM, or M-GIEBCM, in which we first use GIEBCM to calculate a T matrix (transition matrix) database of "straws" with various lengths, thicknesses, orientations, curvatures, and dielectric properties; we then construct the grass with a group of straws from the database and apply GIEBCM again to calculate the T matrix of the overall grass scene. The grass T matrix is transferred to S matrix (scattering matrix) and combined with the ground S matrix, which is computed using the stabilized extended boundary condition method, to obtain the total scattering. In this article, we will demonstrate the capability of the model by simulating scattering from scenes with different grass densities, different grass structures, different grass water contents, and different ground moisture contents. This model will help with radar experiment design and image interpretation for marshland and wetland observations.

Quantum spectral curve for ( q, t)-matrix model

NASA Astrophysics Data System (ADS)

Zenkevich, Yegor

2018-02-01

We derive quantum spectral curve equation for ( q, t)-matrix model, which turns out to be a certain difference equation. We show that in Nekrasov-Shatashvili limit this equation reproduces the Baxter TQ equation for the quantum XXZ spin chain. This chain is spectral dual to the Seiberg-Witten integrable system associated with the AGT dual gauge theory.

The condition of a finite Markov chain and perturbation bounds for the limiting probabilities

NASA Technical Reports Server (NTRS)

Meyer, C. D., Jr.

1979-01-01

The inequalities bounding the relative error the norm of w- w squiggly/the norm of w are exhibited by a very simple function of E and A. Let T denote the transition matrix of an ergodic chain, C, and let A = I - T. Let E be a perturbation matrix such that T squiggly = T - E is also the transition matrix of an ergodic chain, C squiggly. Let w and w squiggly denote the limiting probability (row) vectors for C and C squiggly. The inequality is the best one possible. This bound can be significant in the numerical determination of the limiting probabilities for an ergodic chain. In addition to presenting a sharp bound for the norm of w-w squiggly/the norm of w an explicit expression for w squiggly will be derived in which w squiggly is given as a function of E, A, w and some other related terms.

Symposium Review: Metal and Polymer Matrix Composites at MS&T 2013

NASA Astrophysics Data System (ADS)

Gupta, Nikhil; Paramsothy, Muralidharan

2014-06-01

This article reflects on the presentations made during the Metal and Polymer Matrix Composites symposium at Materials Science and Technology 2013 (MS&T'13) held in Montreal (Quebec, Canada) from October 27 to 31. The symposium had three sessions on metal matrix composites and one session on polymer matrix composites containing a total of 23 presentations. While the abstracts and full-text papers are available through databases, the discussion that took place during the symposium is often not captured in writing and gets immediately lost. We have tried to recap some of the discussion in this article and hope that it will supplement the information present in the proceedings. The strong themes in the symposium were porous composites, aluminum matrix composites, and nanocomposites. The development of processing methods was also of interest to the speakers and attendees.

Method of multivariate spectral analysis

DOEpatents

Keenan, Michael R.; Kotula, Paul G.

2004-01-06

A method of determining the properties of a sample from measured spectral data collected from the sample by performing a multivariate spectral analysis. The method can include: generating a two-dimensional matrix A containing measured spectral data; providing a weighted spectral data matrix D by performing a weighting operation on matrix A; factoring D into the product of two matrices, C and S.sup.T, by performing a constrained alternating least-squares analysis of D=CS.sup.T, where C is a concentration intensity matrix and S is a spectral shapes matrix; unweighting C and S by applying the inverse of the weighting used previously; and determining the properties of the sample by inspecting C and S. This method can be used to analyze X-ray spectral data generated by operating a Scanning Electron Microscope (SEM) with an attached Energy Dispersive Spectrometer (EDS).

Moving-Bank Multiple Model Adaptive Estimation and Control Applied to a Large Flexible Space Structure

DTIC Science & Technology

1990-12-01

was determined from the difference between the 24-state matrix product, HtP (t’)HT, and the six-state matrix product, HfPf (tT)HT’. For this...The true position for node 7, which represents the rigid body position of the structure, is not damped and can be interpreted as a rigid body...application, considering the same issues as explored in this research. Continue with a physical interpretation of the structure positions for determining the

Carrier Aviation and Hybrid Conflict: The Future of the Strike Fighter

DTIC Science & Technology

2011-05-01

MDTC NTA NTSIR OCA OEF OIF PGM. ROE SACT SAM SAR· SEAD SFARP SFTI SFWT .STW T& R TST UAS UCAS-D ULT Acronyms Anti Air Warfare...34tance ’ \\ ’ ’ of air-to-air training, or suggest a change to the training and readiness matrix (T& R ) or IDRC, but rather examine the mission...illustrate another example of the emphasis on air-to~air. In 2008, the new T & R matrix for the USMC F/ A-18 eliminated the Air Combat Tactics

Neutrino Mixing and the Double Tetrahedral Group

NASA Astrophysics Data System (ADS)

Bentov, Yoni; Zee, A.

2013-11-01

In the spirit of a previous study of the tetrahedral group T ≃A4, we discuss a minimalist scheme to derive the neutrino mixing matrix using the double tetrahedral group T‧, the double cover of T. The new features are three distinct two-dimensional representations and complex Clebsch-Gordan coefficients, which can result in a geometric source of CP violation in the neutrino mass matrix. In an appendix, we derive explicitly the relevant group theory for the tetrahedral group T and its double cover T‧.

Ab initio method for calculating total cross sections

NASA Technical Reports Server (NTRS)

Bhatia, A. K.; Schneider, B. I.; Temkin, A.

1993-01-01

A method for calculating total cross sections without formally including nonelastic channels is presented. The idea is to use a one channel T-matrix variational principle with a complex correlation function. The derived T matrix is therefore not unitary. Elastic scattering is calculated from T-parallel-squared, but total scattering is derived from the imaginary part of T using the optical theorem. The method is applied to the spherically symmetric model of electron-hydrogen scattering. No spurious structure arises; results for sigma(el) and sigma(total) are in excellent agreement with calculations of Callaway and Oza (1984). The method has wide potential applicability.

Modeling cometary photopolarimetric characteristics with Sh-matrix method

NASA Astrophysics Data System (ADS)

Kolokolova, L.; Petrov, D.

2017-12-01

Cometary dust is dominated by particles of complex shape and structure, which are often considered as fractal aggregates. Rigorous modeling of light scattering by such particles, even using parallelized codes and NASA supercomputer resources, is very computer time and memory consuming. We are presenting a new approach to modeling cometary dust that is based on the Sh-matrix technique (e.g., Petrov et al., JQSRT, 112, 2012). This method is based on the T-matrix technique (e.g., Mishchenko et al., JQSRT, 55, 1996) and was developed after it had been found that the shape-dependent factors could be separated from the size- and refractive-index-dependent factors and presented as a shape matrix, or Sh-matrix. Size and refractive index dependences are incorporated through analytical operations on the Sh-matrix to produce the elements of T-matrix. Sh-matrix method keeps all advantages of the T-matrix method, including analytical averaging over particle orientation. Moreover, the surface integrals describing the Sh-matrix elements themselves can be solvable analytically for particles of any shape. This makes Sh-matrix approach an effective technique to simulate light scattering by particles of complex shape and surface structure. In this paper, we present cometary dust as an ensemble of Gaussian random particles. The shape of these particles is described by a log-normal distribution of their radius length and direction (Muinonen, EMP, 72, 1996). Changing one of the parameters of this distribution, the correlation angle, from 0 to 90 deg., we can model a variety of particles from spheres to particles of a random complex shape. We survey the angular and spectral dependencies of intensity and polarization resulted from light scattering by such particles, studying how they depend on the particle shape, size, and composition (including porous particles to simulate aggregates) to find the best fit to the cometary observations.

Phosphate Uptake-Independent Signaling Functions of the Type III Sodium-Dependent Phosphate Transporter, PiT-1, in Vascular Smooth Muscle Cells

PubMed Central

Chavkin, Nicholas W.; Jun Chia, Jia; Crouthamel, Matthew H.; Giachelli, Cecilia M.

2015-01-01

Vascular calcification (VC) is prevalent in chronic kidney disease and elevated serum inorganic phosphate (Pi) is a recognized risk factor. The type III sodium-dependent phosphate transporter, PiT-1, is required for elevated Pi-induced osteochondrogenic differentiation and matrix mineralization in vascular smooth muscle cells (VSMCs). However, the molecular mechanism(s) by which PiT-1 promotes these processes is unclear. In the present study, we confirmed that the Pi concentration required to induce osteochondrogenic differentiation and matrix mineralization of mouse VSMCs was well above that required for maximal Pi uptake, suggesting a signaling function of PiT-1 that was independent of Pi transport. Elevated Pi-induced signaling via ERK1/2 phosphorylation was abrogated in PiT-1 deficient VSMCs, but could be rescued by wild-type (WT) and a Pi transport-deficient PiT-1 mutant. Furthermore, both WT and transport-deficient PiT-1 mutants promoted osteochondrogenic differentiation as measured by decreased SM22α and increased osteopontin mRNA expression. Finally, compared to vector alone, expression of transport-deficient PiT-1 mutants promoted VSMC matrix mineralization, but not to the extent observed with PiT-1 WT. These data suggest that both Pi uptake-dependent and -independent functions of PiT-1 are important for VSMC processes mediating vascular calcification. PMID:25684711

Oscillation of two-dimensional linear second-order differential systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kwong, M.K.; Kaper, H.G.

This article is concerned with the oscillatory behavior at infinity of the solution y: (a, infinity) ..-->.. R/sup 2/ of a system of two second-order differential equations, y''(t) + Q(t) y(t) = 0, t epsilon(a, infinity); Q is a continuous matrix-valued function on (a, infinity) whose values are real symmetric matrices of order 2. It is shown that the solution is oscillatory at infinity if the largest eigenvalue of the matrix integral/sub a//sup t/ Q(s) ds tends to infinity as t ..-->.. infinity. This proves a conjecture of D. Hinton and R.T. Lewis for the two-dimensional case. Furthermore, it ismore » shown that considerably weaker forms of the condition still suffice for oscillatory behavior at infinity. 7 references.« less

Multi-cut solutions in Chern-Simons matrix models

NASA Astrophysics Data System (ADS)

Morita, Takeshi; Sugiyama, Kento

2018-04-01

We elaborate the Chern-Simons (CS) matrix models at large N. The saddle point equations of these matrix models have a curious structure which cannot be seen in the ordinary one matrix models. Thanks to this structure, an infinite number of multi-cut solutions exist in the CS matrix models. Particularly we exactly derive the two-cut solutions at finite 't Hooft coupling in the pure CS matrix model. In the ABJM matrix model, we argue that some of multi-cut solutions might be interpreted as a condensation of the D2-brane instantons.

T-Matrix Method and its Applications to Electromagnetic Scattering by Particles: A Current Perspective

NASA Technical Reports Server (NTRS)

Mishchenko, Michael I.; Travis, Larry D.; Mackowski, Daniel W.

2010-01-01

This note serves as a short introduction to the reprint of our article "T-matrix computations of light scattering by nonspherical particles: a review" (JQSRT 1996; 55:535:75). We first discuss the motivation for writing that article and explain its historical context. This is followed by a short overview of more recent developments.

A momentum-space formulation without partial wave decomposition for scattering of two spin-half particles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fachruddin, Imam, E-mail: imam.fachruddin@sci.ui.ac.id; Salam, Agus

2016-03-11

A new momentum-space formulation for scattering of two spin-half particles, both either identical or unidentical, is formulated. As basis states the free linear-momentum states are not expanded into the angular-momentum states, the system’s spin states are described by the product of the spin states of the two particles, and the system’s isospin states by the total isospin states of the two particles. We evaluate the Lippmann-Schwinger equations for the T-matrix elements in these basis states. The azimuthal behavior of the potential and of the T-matrix elements leads to a set of coupled integral equations for the T-matrix elements in twomore » variables only, which are the magnitude of the relative momentum and the scattering angle. Some symmetry relations for the potential and the T-matrix elements reduce the number of the integral equations to be solved. A set of six spin operators to express any interaction of two spin-half particles is introduced. We show the spin-averaged differential cross section as being calculated in terms of the solution of the set of the integral equations.« less

On functions of quasi-Toeplitz matrices

NASA Astrophysics Data System (ADS)

Bini, D. A.; Massei, S.; Meini, B.

2017-11-01

Let a(z)=\\sumi\\in Za_iz^i be a complex-valued function, defined for |z|=1, such that \\sumi=-∞+∞|ia_i|<∞. Consider the semi-infinite Toeplitz matrix T(a)=(ti,j)i,j\\in Z^+ associated with the symbol a(z) such that {ti,j=aj-i}. A quasi-Toeplitz matrix associated with the symbol a(z) is a matrix of the form A=T(a)+E where E=(ei,j), \\sumi,j\\in Z^+|ei,j|<∞, and is called a {QT}-matrix. Given a function f(x) and a {QT}-matrix M, we provide conditions under which f(M) is well defined and is a {QT}-matrix. Moreover, we introduce a parametrization of {QT}-matrices and algorithms for the computation of f(M). We treat the case where f(x) is given in terms of power series and the case where f(x) is defined in terms of a Cauchy integral. This analysis is also applied to finite matrices which can be written as the sum of a Toeplitz matrix and a low rank correction. Bibliography: 27 titles.

Apparatus and system for multivariate spectral analysis

DOEpatents

Keenan, Michael R.; Kotula, Paul G.

2003-06-24

An apparatus and system for determining the properties of a sample from measured spectral data collected from the sample by performing a method of multivariate spectral analysis. The method can include: generating a two-dimensional matrix A containing measured spectral data; providing a weighted spectral data matrix D by performing a weighting operation on matrix A; factoring D into the product of two matrices, C and S.sup.T, by performing a constrained alternating least-squares analysis of D=CS.sup.T, where C is a concentration intensity matrix and S is a spectral shapes matrix; unweighting C and S by applying the inverse of the weighting used previously; and determining the properties of the sample by inspecting C and S. This method can be used by a spectrum analyzer to process X-ray spectral data generated by a spectral analysis system that can include a Scanning Electron Microscope (SEM) with an Energy Dispersive Detector and Pulse Height Analyzer.

The extracellular matrix of the oleolytic biofilms of Marinobacter hydrocarbonoclasticus comprises cytoplasmic proteins and T2SS effectors that promote growth on hydrocarbons and lipids.

PubMed

Ennouri, Habiba; d'Abzac, Paul; Hakil, Florence; Branchu, Priscilla; Naïtali, Murielle; Lomenech, Anne-Marie; Oueslati, Ridha; Desbrières, Jacques; Sivadon, Pierre; Grimaud, Régis

2017-01-01

The assimilation of the nearly water insoluble substrates hydrocarbons and lipids by bacteria entails specific adaptations such as the formation of oleolytic biofilms. The present article reports that the extracellular matrix of an oleolytic biofilm formed by Marinobacter hydrocarbonoclasticus at n-hexadecane-water interfaces is largely composed of proteins typically cytoplasmic such as translation factors and chaperones, and a lesser amount of proteins of unknown function that are predicted extra-cytoplasmic. Matrix proteins appear to form a structured film on hydrophobic interfaces and were found mandatory for the development of biofilms on lipids, alkanes and polystyrene. Exo-proteins secreted through the type-2 secretion system (T2SS) were shown to be essential for the formation of oleolytic biofilms on both alkanes and triglycerides. The T2SS effector involved in biofilm formation on triglycerides was identified as a lipase. In the case of biofilm formation on n-hexadecane, the T2SS effector is likely involved in the mass transfer, capture or transport of alkanes. We propose that M. hydrocarbonoclasticus uses cytoplasmic proteins released by cell lysis to form a proteinaceous matrix and dedicated proteins secreted through the T2SS to act specifically in the assimilation pathways of hydrophobic substrates. © 2016 Society for Applied Microbiology and John Wiley & Sons Ltd.

An Efficient Scheme for Updating Sparse Cholesky Factors

NASA Technical Reports Server (NTRS)

Raghavan, Padma

2002-01-01

Raghavan had earlier developed the software package DCSPACK which can be used for solving sparse linear systems where the coefficient matrix is symmetric and positive definite (this project was not funded by NASA but by agencies such as NSF). DSCPACK-S is the serial code and DSCPACK-P is a parallel implementation suitable for multiprocessors or networks-of-workstations with message passing using MCI. The main algorithm used is the Cholesky factorization of a sparse symmetric positive positive definite matrix A = LL(T). The code can also compute the factorization A = LDL(T). The complexity of the software arises from several factors relating to the sparsity of the matrix A. A sparse N x N matrix A has typically less that cN nonzeroes where c is a small constant. If the matrix were dense, it would have O(N2) nonzeroes. The most complicated part of such sparse Cholesky factorization relates to fill-in, i.e., zeroes in the original matrix that become nonzeroes in the factor L. An efficient implementation depends to a large extent on complex data structures and on techniques from graph theory to reduce, identify, and manage fill. DSCPACK is based on an efficient multifrontal implementation with fill-managing algorithms and implementation arising from earlier research by Raghavan and others. Sparse Cholesky factorization is typically a four step process: (1) ordering to compute a fill-reducing numbering, (2) symbolic factorization to determine the nonzero structure of L, (3) numeric factorization to compute L, and, (4) triangular solution to solve L(T)x = y and Ly = b. The first two steps are symbolic and are performed using the graph of the matrix. The numeric factorization step is of dominant cost and there are several schemes for improving performance by exploiting the nested and dense structure of groups of columns in the factor. The latter are aimed at better utilization of the cache-memory hierarchy on modem processors to prevent cache-misses and provide execution rates (operations/second) that are close to the peak rates for dense matrix computations. Currently, EPISCOPACY is being used in an application at NASA directed by J. Newman and M. James. We propose the implementation of efficient schemes for updating the LL(T) or LDL(T) factors computed in DSCPACK-S to meet the computational requirements of their project. A brief description is provided in the next section.

On the Evaluation of Certain Multivariate Normal Probabilities.

DTIC Science & Technology

1982-08-12

a "single- factor matrix" in one context of factor analysis. In this case, we have (Pk 111 n 0# td i-i 2./- jwk+lI. where the sumation is taken over...is an equicorrelation matrix with p > 0, Pk Q k .j * ~sP (t)dt For c O, we have p(n) T, tn % td Pn = tht () 1 1 -pad (3)1 it is well known that pM2 CO...ZI,*.*.,±Zn_ 1 ± Zn) and proceed as above. Another situation for which combinatorial arguments are known are for t with a j = JAJ Vij. This t is

Connective stability of competitive equilibrium

NASA Technical Reports Server (NTRS)

Siljak, D. D.

1975-01-01

The purpose of this paper is to derive necessary and sufficient conditions for the connective stability of nonlinear matrix systems described by the equation x-dot = A(t, x) x, where the matrix A(t, x) has time-varying nonlinear elements. The results obtained can be used to study the stability of competitive equilibrium in fields as diverse as economics and engineering, model ecosystems, and the arms race.-

Entropy Production and Non-Equilibrium Steady States

NASA Astrophysics Data System (ADS)

Suzuki, Masuo

2013-01-01

The long-term issue of entropy production in transport phenomena is solved by separating the symmetry of the non-equilibrium density matrix ρ(t) in the von Neumann equation, as ρ(t) = ρs(t) + ρa(t) with the symmetric part ρs(t) and antisymmetric part ρa(t). The irreversible entropy production (dS/dt)irr is given in M. Suzuki, Physica A 390(2011)1904 by (dS/dt)irr = Tr( {H}(dρ s{(t)/dt))}/T for the Hamiltonian {H} of the relevant system. The general formulation of the extended von Neumann equation with energy supply and heat extraction is reviewed from the author's paper (M. S.,Physica A391(2012)1074). irreversibility; entropy production; transport phenomena; electric conduction; thermal conduction; linear response; Kubo formula; steady state; non-equilibrium density matrix; energy supply; symmetry-separated von Neumann equation; unboundedness.

Hydrocortisone and triiodothyronine regulate hyaluronate synthesis in a tissue-engineered human dermal equivalent through independent pathways.

PubMed

Deshpande, Madhura; Papp, Suzanne; Schaffer, Lana; Pouyani, Tara

2015-02-01

Hydrocortisone (HC) and triiodothyronine (T3) have both been shown to be capable of independently inhibiting hyaluronate (HA, hyaluronic acid) synthesis in a self-assembled human dermal equivalent (human dermal matrix). We sought to investigate the action of these two hormones in concert on extracellular matrix formation and HA inhibition in the tissue engineered human dermal matrix. To this end, neonatal human dermal fibroblasts were cultured in defined serum-free medium for 21 days in the presence of each hormone alone, or in combination, in varying concentrations. Through a process of self-assembly, a substantial dermal extracellular matrix formed that was characterized. The results of these studies demonstrate that combinations of the hormones T3 and hydrocortisone showed significantly higher levels of hyaluronate inhibition as compared to each hormone alone in the human dermal matrix. In order to gain preliminary insight into the genes regulating HA synthesis in this system, a differential gene array analysis was conducted in which the construct prepared in the presence of 200 μg/mL HC and 0.2 nM T3 was compared to the normal construct (0.4 μg/mL HC and 20 pM T3). Using a GLYCOv4 gene chip containing approximately 1260 human genes, we observed differential expression of 131 genes. These data suggest that when these two hormones are used in concert a different mechanism of inhibition prevails and a combination of degradation and inhibition of HA synthesis may be responsible for HA regulation in the human dermal matrix. Copyright © 2014 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Freeman, John

A measurement of the top quark mass in tmore » $$\\bar{t}$$ → 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.« less

Energy Dissipation of Rayleigh Waves due to Absorption Along the Path by the Use of Finite Element Method

DTIC Science & Technology

1979-07-31

3 x 3 t Strain vector a ij,j Space derivative of the stress tensor Fi Force vector per unit volume o Density x CHAPTER III F Total force K Stiffness...matrix 6Vector displacements M Mass matrix B Space operating matrix DO Matrix moduli 2 x 3 DZ Operating matrix in Z direction N Matrix of shape...dissipating medium the deformation of a solid is a function of time, temperature and space . Creep phenomenon is a deformation process in which there is

Mechanical Properties of SiC, Al2O3 Reinforced Aluminium 6061-T6 Hybrid Matrix Composite

NASA Astrophysics Data System (ADS)

Murugan, S. Senthil; Jegan, V.; Velmurugan, M.

2018-04-01

This paper contains the investigation of tensile, compression and impact characterization of SiC, Al2O3 reinforced Aluminium 6061-T6 matrix hybrid composite. Hybrid matrix composite fabrication was done by stir casting method. An attempt has been made by keeping Al2O3 percentage (7%) constant and increasing SiC percentage (10, 15, and 20%). After fabricating, the samples were prepared and tested to find out the various mechanical properties like tensile, compressive, and impact strength of the developed composites of different weight % of silicon carbide and Alumina in Aluminium alloy. The main objective of the study is to compare the values obtained and choose the best composition of the hybrid matrix composite from the mechanical properties point of view.

Evaluation of oral keratinocyte progenitor and T-lymphocite cells response during early healing after augmentation of keratinized gingiva with a 3D collagen matrix - a pilot study.

PubMed

Rusu, Darian; Calenic, Bogdan; Greabu, Maria; Kralev, Alexander; Boariu, Marius; Bojin, Florina; Anghel, Simona; Paunescu, Virgil; Vela, Octavia; Calniceanu, Horia; Stratul, Stefan-Ioan

2016-07-07

The aim of the present study is to analyze the behavior of selected populations of oral keratinocytes and T-lymphocytes, responsible for re-constructing and maintaining the oral epithelial tissue architecture, following augmentation of the keratinized oral mucosa using a 3D-collagen matrix. Different groups of oral keratinocytes were isolated from biopsies harvested from 3 patients before the surgical procedure, as well as 7 and 14 days after the augmentation procedure. T-lymphocytes were isolated from peripheral blood at same timepoints. Keratinocytes were characterized for stem and differentiation markers, such as p63, cytokeratin 10 and 14, and in vitro parameters, such as cell viability, cell size and colony-forming efficiency. T-lymphocytes were analyzed for viability and the expression of various cluster of differentiation markers. The methods included magnetic separation of cell populations, immunofluorescence, flow cytometry, and histology of oral biopsies. Both at 7 and 14 days, the majority of cells that repopulate the matrix were actively proliferating/progenitor oral keratinocytes with the phenotype integrin alfa6beta4 + CD71+. These cells display in vitro characteristics similar to the progenitor cells analyzed before the matrix placement. T-lymphocytes expressed CD8 and CD69 markers, while CD25 was absent. The study shows that two weeks after the collagen membrane placement, the healing process appeared to be histologically complete, with no abnormal immune response induced by the matrix, however, with a higher than usual content of active proliferating cells, the majority of keratinocytes being characterized as transit amplifying cells.

Violations of K-Conservation in 178Hf

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hayes, A. B.; Cline, D.; Wu, C. Y.

2006-03-13

Coulomb excitation of K{pi}=6+(t1/2=77 ns), 8-(t1/2=4.0 s) and 16+(t1/2=31 y) 178Hf isomers has led to the measurement of a set of E{lambda} matrix elements, coupling the isomer bands to the {gamma}- and ground state bands. The resulting matrix elements, derived using a coupled-channel semiclassical Coulomb excitation search code, have been used to probe the K-components in the wave functions and revealed the onset and saturation of K-mixing in low-K bands, whereas K-mixing is negligible in the high-K bands. The implications can be applied to other quadrupole-deformed nuclei. An upper limit on the Coulomb depopulation yield of the 16+ isomer wasmore » calculated based on the present set of matrix elements.« less

Release of Matrix Metalloproteinases-2 and 9 by S-Nitrosylated Caveolin-1 Contributes to Degradation of Extracellular Matrix in tPA-Treated Hypoxic Endothelial Cells

PubMed Central

Bi, Gang; Zhu, Yihui; Jun, Wei; Ma, Wenlin; Wu, Huimin

2016-01-01

Intracranial hemorrhage remains the most feared complication in tissue plasminogen activator (tPA) thrombolysis for ischemic stroke. However, the underlying molecular mechanisms are still poorly elucidated. In this study, we reported an important role of caveolin-1 (Cav-1) s-nitrosylation in matrix metalloproteinase (MMP)-2 and 9 secretion from tPA-treated ischemic endothelial cells. Brain vascular endothelial cells (bEND3) were exposed to oxygen-glucose deprivation (OGD) for 2 h before adding recombinant human tPA for 6 h. This treatment induced a significant increase of MMP2 and 9 in the media of bEND3 cells and a simultaneous degradation of fibronectin and laminin β-1, the two main components of extracellular matrix (ECM). Inhibition of MMP2 and 9 with SB-3CT completely blocked the degradation of fibronectin and laminin β-1. ODG+tPA treatment led to Cav-1 shedding from bEND3 cells into the media. Notably, OGD triggered nitric oxide (NO) production and S-nitrosylationof Cav-1 (SNCav-1). Meanwhile tPA induced activation of ERK signal pathway and stimulates the secretion of SNCav-1. Pretreatment of bEND3 cells with C-PTIO (a NO scavenger) or U0126 (a specific ERK inhibitor) significantly reduced OGD-induced S-nitrosylation of Cav-1 in cells and blocked the secretion of Cav-1 and MMP2 and 9 into the media as well as the degradation of fibronectin and laminin β-1 in OGD and tPA-treated cells. These data indicate that OGD-triggered Cav-1 S-nitrosylation interacts with tPA-induced ERK activation to augment MMP2 and 9 secretion and subsequent ECM degradation, which may account for the exacerbation of ischemic blood brain barrier damage following tPA thrombolysis for ischemic stroke. PMID:26881424

Release of Matrix Metalloproteinases-2 and 9 by S-Nitrosylated Caveolin-1 Contributes to Degradation of Extracellular Matrix in tPA-Treated Hypoxic Endothelial Cells.

PubMed

Song, Haoming; Cheng, Youjun; Bi, Gang; Zhu, Yihui; Jun, Wei; Ma, Wenlin; Wu, Huimin

2016-01-01

Intracranial hemorrhage remains the most feared complication in tissue plasminogen activator (tPA) thrombolysis for ischemic stroke. However, the underlying molecular mechanisms are still poorly elucidated. In this study, we reported an important role of caveolin-1 (Cav-1) s-nitrosylation in matrix metalloproteinase (MMP)-2 and 9 secretion from tPA-treated ischemic endothelial cells. Brain vascular endothelial cells (bEND3) were exposed to oxygen-glucose deprivation (OGD) for 2 h before adding recombinant human tPA for 6 h. This treatment induced a significant increase of MMP2 and 9 in the media of bEND3 cells and a simultaneous degradation of fibronectin and laminin β-1, the two main components of extracellular matrix (ECM). Inhibition of MMP2 and 9 with SB-3CT completely blocked the degradation of fibronectin and laminin β-1. ODG+tPA treatment led to Cav-1 shedding from bEND3 cells into the media. Notably, OGD triggered nitric oxide (NO) production and S-nitrosylationof Cav-1 (SNCav-1). Meanwhile tPA induced activation of ERK signal pathway and stimulates the secretion of SNCav-1. Pretreatment of bEND3 cells with C-PTIO (a NO scavenger) or U0126 (a specific ERK inhibitor) significantly reduced OGD-induced S-nitrosylation of Cav-1 in cells and blocked the secretion of Cav-1 and MMP2 and 9 into the media as well as the degradation of fibronectin and laminin β-1 in OGD and tPA-treated cells. These data indicate that OGD-triggered Cav-1 S-nitrosylation interacts with tPA-induced ERK activation to augment MMP2 and 9 secretion and subsequent ECM degradation, which may account for the exacerbation of ischemic blood brain barrier damage following tPA thrombolysis for ischemic stroke.

Transformer-4 version 2.0.1, a free multi-platform software to quickly reformat genotype matrices of any marker type, and archive them in the Demiurge information system.

PubMed

Caujapé-Castells, Juli; Sabbagh, Izzat; Castellano, José J; Ramos, Rafael; Henríquez, Víctor; Quintana, Francisco M; Medina, Dailos A; Toledo, Javier; Ramírez, Fernando; Rodríguez, Juan F

2013-05-01

Transformer-4 version 2.0.1 (T4) is a multi-platform freeware programmed in java that can transform a genotype matrix in Excel or XML format into the input formats of one or several of the most commonly used population genetic software, for any possible combination of the populations that the matrix contains. T4 also allows the users to (i) draw allozyme gel interpretations for any number of diploid individuals, and then generate a genotype matrix ready to be used by T4; and (ii) produce basic reports about the data in the matrices. Furthermore, T4 is the only way to optionally submit 'genetic diversity digests' for publication in the Demiurge online information system (http://www.demiurge-project.org). Each such digest undergoes peer-review, and it consists of a geo-referenced data matrix in the tfm4 format plus any ancillary document or hyperlink that the digest authors see fit to include. The complementarity between T4 and Demiurge facilitates a free, safe, permanent, and standardized data archival and analysis system for researchers, and may also be a convenient resource for scientific journals, public administrations, or higher educators. T4 and its converters are freely available (at, respectively, http://www.demiurge-project.org/download_t4 and http://www.demiurge-project.org/converterstore) upon registration in the Demiurge information system (http://demiurge-project.org/register). Users have to click on the link provided on an account validation email, and accept Demiurge's terms of use (see http://www.demiurge-project.org/termsofuse). A thorough user's guide is available within T4. A 3-min promotional video about T4 and Demiurge can be seen at http://vimeo.com/29828406. © 2013 Blackwell Publishing Ltd.

Factorization and fitting of molecular scattering information

DOE Office of Scientific and Technical Information (OSTI.GOV)

Goldflam, R.; Kouri, D.J.; Green, S.

1977-12-15

The factorization of cross sections of various kinds resulting from the infinite order sudden approximation is considered in detail. Unlike the earlier study of Goldflam, Green, and Kouri, we base the present analysis on the factored IOS T-matrix rather than on the S-matrix. This enables us to obtain somewhat simpler expressions. For example, we show that the factored IOS approximation to the Arthurs--Dalgarno T-matrix involves products of dynamical coefficients T/sup L//sub l/ and Percival--Seaton coefficients f/sub L/(jlvertical-barj/sub 0/l/sub 0/vertical-barJ). It is shown that an optical theorem exists for the T/sub l//sup L/ dynamical coefficients of the T-matrix. The differential scatteringmore » amplitudes are shown to factor into dynamical coefficients q/sub L/(chi) times spectroscopic factors that are independent of the dynamics (potential). Then a generalized form of the Parker--Pack result for ..sigma../sub j/(dsigma/dR)(j/sub 0/..-->..j) is derived. It is also shown that the IOS approximation for (dsigma/dR)(j/sub 0/..-->..j) factors into sums of spectroscopic coefficients times the differential cross sections out of j/sub 0/=0. The IOS integral cross sections factor into spectroscopic coefficients times the integral cross sections out of j/sub 0/=0. The factored IOS general phenomenological cross sections are rederived using the T-matrix approach and are shown to equal sums of Percival--Seaton coefficients timesthe inelastic integral cross section out of initial rotor state j/sub 0/ = 0. This suggests that experimental measurements of line shapes and/or NMR spin--lattice relaxation can be used to directly give inelastic state-to-state degeneracy averaged integral cross sections whenever the IOS is a good approximation. Factored IOS expressions for viscosity and diffusion are derived and shown to potentially yield additional information beyond that contained in line shapes.« less

CM-like Interplanetary Dust Particles in Lower Stratosphere During 1989 October and 1991 June/July

NASA Technical Reports Server (NTRS)

Rietmeijer, Frans J. M.

1996-01-01

The stratospheric interplanetary dust particles L2005T12 and L2011O3 are linked to CM chondrite matrix. Particle L2005T12 is dominated by tabular grains of partially dehydrated greenalite-rich serpentine. Its amorphous matrix contains abundant smectite nanocrystals and annular Fe,Ni,S units. A uniquely stratified (partial) maghemite rim occurs only on S-rich parts of the matrix. Formation of this rim and Mg depletions in the matrix occurred during atmospheric entry heating of this particle. Particle L2011O3 has large iron sulfide and magnesiowustite grains in an amorphous low-Al, ferromagnesiosilica matrix. Hydrous crystallisation of this matrix produced ultrafine-grained smectites and disseminated iron sulfides. Atmospheric entry heating of both particles is indicated by the partial iron oxide rim, vesicular sulfides, and the scatter of matrix compositions due to loss of Mg. While many uncertainties remain, the high incidence of chondritic rough particles, which include an unknown amount of CM-like particles, in the lower stratosphere during 1984, 1989, and 1991 suggests annual variations in their abundances. The timing of lower stratospheric dust samplings is critical to collect these particles.

Algorithms for Solvents and Spectral Factors of Matrix Polynomials

DTIC Science & Technology

1981-01-01

spectral factors of matrix polynomials LEANG S. SHIEHt, YIH T. TSAYt and NORMAN P. COLEMANt A generalized Newton method , based on the contracted gradient...of a matrix poly- nomial, is derived for solving the right (left) solvents and spectral factors of matrix polynomials. Two methods of selecting initial...estimates for rapid convergence of the newly developed numerical method are proposed. Also, new algorithms for solving complete sets of the right

Connective stability of nonlinear matrix systems

NASA Technical Reports Server (NTRS)

Siljak, D. D.

1974-01-01

Consideration of stability under structural perturbations of free dynamic systems described by the differential equation dx/dt = A(t,x)x, where the matrix A(t,x) has time-varying nonlinear elements. The concept of 'connective stability' is introduced to study the structural properties of competitive-cooperative nonlinear matrix systems. It is shown that stability reliability in such systems is high and that they remain stable despite time-varying (including 'on-off') interaction among individual agents present in the system. The results obtained can be used to study stability aspects of mathematical models arising in as diverse fields as economics, biology, arms races, and transistor circuits.

Characterization of AA2024-T3 by scanning Kelvin probe force microscopy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schmutz, P.; Frankel, G.S.

1998-07-01

Volta potential mapping of AA2024-T3 on surfaces was performed with an atomic force microscope. A linear relation was found between the Volta potential measured in air and the corrosion potential in aqueous solution for a range of pure metal samples, indicating that this potential is a measurement of the practical nobility of the surface. Large differences in the Volta potential of intermetallic particles in AA2024-T3 and the matrix phase resulted in a potential map with high contrast that clearly identifies the location of the particles. All intermetallic particles, including the Mg-containing S-phase particles, had a Volta potential noble to thatmore » of the matrix. Surface films on the particles and the matrix were found to have strong effects on the potential, and probably explain the noble nature of the Mg-containing particles, which have been reported to be active to the matrix in solution. The effect of these surface films was examined by refreshing the sample surface using different techniques. Lateral heterogeneities in certain intermetallic particles were also revealed.« less

Integrins in T Cell Physiology

PubMed Central

Alabiso, Oscar; Galetto, Alessandra Silvia; Baldanzi, Gianluca

2018-01-01

From the thymus to the peripheral lymph nodes, integrin-mediated interactions with neighbor cells and the extracellular matrix tune T cell behavior by organizing cytoskeletal remodeling and modulating receptor signaling. LFA-1 (αLβ2 integrin) and VLA-4 (α4β1 integrin) play a key role throughout the T cell lifecycle from thymocyte differentiation to lymphocyte extravasation and finally play a fundamental role in organizing immune synapse, providing an essential costimulatory signal for the T cell receptor. Apart from tuning T cell signaling, integrins also contribute to homing to specific target organs as exemplified by the importance of α4β7 in maintaining the gut immune system. However, apart from those well-characterized examples, the physiological significance of the other integrin dimers expressed by T cells is far less understood. Thus, integrin-mediated cell-to-cell and cell-to-matrix interactions during the T cell lifespan still represent an open field of research. PMID:29415483

Matrix metalloproteinase-2 gene variants and abdominal aortic aneurysm.

PubMed

Smallwood, L; Warrington, N; Allcock, R; van Bockxmeer, F; Palmer, L J; Iacopetta, B; Golledge, J; Norman, P E

2009-08-01

To investigate associations between two polymorphisms of the matrix metalloproteinase-2 gene (MMP2) and the incidence and progression of abdominal aortic aneurysm (AAA). Cases and controls were recruited from a trial of screening for AAAs. The association between two variants of MMP2 (-1360C>T, and +649C>T) in men with AAA (n=678) and in controls (n=659) was examined using multivariate analyses. The association with AAA expansion (n=638) was also assessed. In multivariate analyses with adjustments for multiple testing, no association between either SNP and AAA presence or expansion was detected. MMP2 -1360C>T and +649C>T variants are not risk factors for AAA.

First step in developing a 3D biodegradable fibrin scaffold for an artificial ovary.

PubMed

Luyckx, Valérie; Dolmans, Marie-Madeleine; Vanacker, Julie; Scalercio, Sarah R; Donnez, Jacques; Amorim, Christiani A

2013-11-25

Although transplantation of cryopreserved ovarian tissue is a promising approach to restore fertility in cancer patients, it is not advisable for women at risk of ovarian involvement due to the threat of reintroducing malignant cells. The aim of this study was therefore to find an alternative for these patients by development of an artificial ovary. For construction of the artificial ovary matrix, we used a central composite design to investigate nine combinations of fibrinogen (mg/ml) and thrombin (IU/mL) (F/T): F1/T4, F12.5/T1, F12.5/T20, F25/T0.1, F25/T4, F25/T500, F50/T1, F50/T20 and F100/T4. From the first qualitative analyses (handling and matrix size), five combinations (F12.5/T1, F25/T4, F50/T20, F50/T1 and F100/T4) yielded positive results. They were further evaluated in order to assess fibrin matrix degradation and homogeneous cell encapsulation (density), survival and proliferation (Ki67), and atresia (TUNEL) before and after 7 days of in vitro culture. To determine the best compromise between maximizing the dynamic density (Y1) and minimizing the apoptosis rate (Y2), we used the desirability function approach. Two combinations (F12.5/T1 and F25/T4) showed greater distribution of cells before in vitro culture, reproducible degradation of the fibrin network and adequate support for isolated human ovarian stromal cells, with a high proportion of Ki67-positive cells. SEM analysis revealed a network of fibers with regular pores and healthy stromal cells after in vitro culture with both F/T combinations. This study reports two optimal F/T combinations that allow survival and proliferation of isolated human ovarian cells. Further studies are required to determine if such a scaffold will also be a suitable environment for isolated ovarian follicles.

Maximum Entropy/Optimal Projection Design Synthesis for Decentralized Control of Large Space Structures

DTIC Science & Technology

1988-05-01

M 21 M2 I SI M1l[11 II1211 - - - M= II 2+111 I11-211 NONNEGATIVE CONE ORDERING Figure 25. The Matrix Majorant Is a Bound for the Hatrix Block Norm...the with respect to the cone of nonnegative -definite matrices. inequality (1.5) by the r x r nonnegative matrix equation Indeed, the majorant bound...t) eA-) e ea ’ A rT(" 3 ds, t> O , ju E [0 , 1] 0 J(G, )= tr (0,(6)R,) which is monotonically increasing in the nonnegative -definite G , cone with

Matrix Isolation and ab initio study of the noncovalent complexes between formamide and acetylene.

PubMed

Mardyukov, Artur; Sánchez-García, Elsa; Sander, Wolfram

2009-02-12

Matrix isolation spectroscopy in combination with ab initio calculations is a powerful technique for the identification of weakly bound intermolecular complexes. Here, weak complexes between formamide and acetylene are studied, and three 1:1 complexes with binding energies of -2.96, -2.46, and -1.79 kcal/mol have been found at the MP2 level of theory (MP2/cc-pVTZ + ZPE + BSSE). The two most stable dimers A and B are identified in argon and nitrogen matrices by comparison between the experimental and calculated infrared frequencies. Both complexes are stabilized by the formamide C=O...HC acetylene and H...pi interactions. Large shifts have been observed experimentally for the C-H stretching vibrations of the acetylene molecule, in very good agreement with the calculated values. Eight 1:2 FMA-acetylene trimers (T-A to T-H) with binding energies between -5.44 and -2.62 kcal/mol (MP2/aug-cc-pVDZ + ZPE + BSSE) were calculated. The two most stable trimers T-A and T-B are very close in energy and have similar infrared spectra. Several weak bands that are in agreement with the calculated frequencies of the trimers T-A and T-B are observed under matrix isolation conditions. However, the differences are too small for a definitive assignment.

A new molecular evolution model for limited insertion independent of substitution.

PubMed

Lèbre, Sophie; Michel, Christian J

2013-10-01

We recently introduced a new molecular evolution model called the IDIS model for Insertion Deletion Independent of Substitution [13,14]. In the IDIS model, the three independent processes of substitution, insertion and deletion of residues have constant rates. In order to control the genome expansion during evolution, we generalize here the IDIS model by introducing an insertion rate which decreases when the sequence grows and tends to 0 for a maximum sequence length nmax. This new model, called LIIS for Limited Insertion Independent of Substitution, defines a matrix differential equation satisfied by a vector P(t) describing the sequence content in each residue at evolution time t. An analytical solution is obtained for any diagonalizable substitution matrix M. Thus, the LIIS model gives an expression of the sequence content vector P(t) in each residue under evolution time t as a function of the eigenvalues and the eigenvectors of matrix M, the residue insertion rate vector R, the total insertion rate r, the initial and maximum sequence lengths n0 and nmax, respectively, and the sequence content vector P(t0) at initial time t0. The derivation of the analytical solution is much more technical, compared to the IDIS model, as it involves Gauss hypergeometric functions. Several propositions of the LIIS model are derived: proof that the IDIS model is a particular case of the LIIS model when the maximum sequence length nmax tends to infinity, fixed point, time scale, time step and time inversion. Using a relation between the sequence length l and the evolution time t, an expression of the LIIS model as a function of the sequence length l=n(t) is obtained. Formulas for 'insertion only', i.e. when the substitution rates are all equal to 0, are derived at evolution time t and sequence length l. Analytical solutions of the LIIS model are explicitly derived, as a function of either evolution time t or sequence length l, for two classical substitution matrices: the 3-parameter symmetric substitution matrix [12] (LIIS-SYM3) and the HKY asymmetric substitution matrix[9] (LIIS-HKY). An evaluation of the LIIS model (precisely, LIIS-HKY) based on four statistical analyses of the GC content in complete genomes of four prokaryotic taxonomic groups, namely Chlamydiae, Crenarchaeota, Spirochaetes and Thermotogae, shows the expected improvement from the theory of the LIIS model compared to the IDIS model. Copyright © 2013 Elsevier Inc. All rights reserved.

Accuracy of whole-genome prediction using a genetic architecture-enhanced variance-covariance matrix.

PubMed

Zhang, Zhe; Erbe, Malena; He, Jinlong; Ober, Ulrike; Gao, Ning; Zhang, Hao; Simianer, Henner; Li, Jiaqi

2015-02-09

Obtaining accurate predictions of unobserved genetic or phenotypic values for complex traits in animal, plant, and human populations is possible through whole-genome prediction (WGP), a combined analysis of genotypic and phenotypic data. Because the underlying genetic architecture of the trait of interest is an important factor affecting model selection, we propose a new strategy, termed BLUP|GA (BLUP-given genetic architecture), which can use genetic architecture information within the dataset at hand rather than from public sources. This is achieved by using a trait-specific covariance matrix ( T: ), which is a weighted sum of a genetic architecture part ( S: matrix) and the realized relationship matrix ( G: ). The algorithm of BLUP|GA (BLUP-given genetic architecture) is provided and illustrated with real and simulated datasets. Predictive ability of BLUP|GA was validated with three model traits in a dairy cattle dataset and 11 traits in three public datasets with a variety of genetic architectures and compared with GBLUP and other approaches. Results show that BLUP|GA outperformed GBLUP in 20 of 21 scenarios in the dairy cattle dataset and outperformed GBLUP, BayesA, and BayesB in 12 of 13 traits in the analyzed public datasets. Further analyses showed that the difference of accuracies for BLUP|GA and GBLUP significantly correlate with the distance between the T: and G: matrices. The new strategy applied in BLUP|GA is a favorable and flexible alternative to the standard GBLUP model, allowing to account for the genetic architecture of the quantitative trait under consideration when necessary. This feature is mainly due to the increased similarity between the trait-specific relationship matrix ( T: matrix) and the genetic relationship matrix at unobserved causal loci. Applying BLUP|GA in WGP would ease the burden of model selection. Copyright © 2015 Zhang et al.

On efficient randomized algorithms for finding the PageRank vector

NASA Astrophysics Data System (ADS)

Gasnikov, A. V.; Dmitriev, D. Yu.

2015-03-01

Two randomized methods are considered for finding the PageRank vector; in other words, the solution of the system p T = p T P with a stochastic n × n matrix P, where n ˜ 107-109, is sought (in the class of probability distributions) with accuracy ɛ: ɛ ≫ n -1. Thus, the possibility of brute-force multiplication of P by the column is ruled out in the case of dense objects. The first method is based on the idea of Markov chain Monte Carlo algorithms. This approach is efficient when the iterative process p {/t+1 T} = p {/t T} P quickly reaches a steady state. Additionally, it takes into account another specific feature of P, namely, the nonzero off-diagonal elements of P are equal in rows (this property is used to organize a random walk over the graph with the matrix P). Based on modern concentration-of-measure inequalities, new bounds for the running time of this method are presented that take into account the specific features of P. In the second method, the search for a ranking vector is reduced to finding the equilibrium in the antagonistic matrix game where S n (1) is a unit simplex in ℝ n and I is the identity matrix. The arising problem is solved by applying a slightly modified Grigoriadis-Khachiyan algorithm (1995). This technique, like the Nazin-Polyak method (2009), is a randomized version of Nemirovski's mirror descent method. The difference is that randomization in the Grigoriadis-Khachiyan algorithm is used when the gradient is projected onto the simplex rather than when the stochastic gradient is computed. For sparse matrices P, the method proposed yields noticeably better results.

Chiral matrix model of the semi-QGP in QCD

DOE PAGES

Pisarski, Robert D.; Skokov, Vladimir V.

2016-08-08

Previously, a matrix model of the region near the transition temperature, in the “semi”quark gluon plasma, was developed for the theory of SU(3) gluons without quarks. In this paper we develop a chiral matrix model applicable to QCD by including dynamical quarks with 2+1 flavors. This requires adding a nonet of scalar fields, with both parities, and coupling these to quarks through a Yukawa coupling, y. Treating the scalar fields in mean field approximation, the effective Lagrangian is computed by integrating out quarks to one loop order. As is standard, the potential for the scalar fields is chosen to bemore » symmetric under the flavor symmetry of SU (3) L × SU(3) R × Z (3) A , except for a term linear in the current quark mass, m qk . In addition, at a nonzero temperature T it is necessary to add a new term, ~ m qk T 2 . The parameters of the gluon part of the matrix model are identical to those for the pure glue theory without quarks. The parameters in the chiral matrix model are fixed by the values, at zero temperature, of the pion decay constant and the masses of the pions, kaons, η , and η' . The temperature for the chiral crossover at T$χ$ = 155 MeV is determined by adjusting the Yukawa coupling y . We find reasonable agreement with the results of numerical simulations on the lattice for the pressure and related quantities. In the chiral limit, besides the divergence in the chiral susceptibility there is also a milder divergence in the susceptibility between the Polyakov loop and the chiral order parameter, with critical exponent β $-$ 1 . We compute derivatives with respect to a quark chemical potential to determine the susceptibilities for baryon number, the $χ$ 2n . Especially sensitive tests are provided by $χ$ 4 $-$ $χ$ 2 and by $χ$ 6 , which changes in sign about T$χ$ . In conclusion, the behavior of the susceptibilities in the chiral matrix model strongly suggests that as the temperature increases from T$χ$ , that the transition to deconfinement is significantly quicker than indicated by the measurements of the (renormalized) Polyakov loop on the lattice.« less

Linear dimension reduction and Bayes classification

NASA Technical Reports Server (NTRS)

Decell, H. P., Jr.; Odell, P. L.; Coberly, W. A.

1978-01-01

An explicit expression for a compression matrix T of smallest possible left dimension K consistent with preserving the n variate normal Bayes assignment of X to a given one of a finite number of populations and the K variate Bayes assignment of TX to that population was developed. The Bayes population assignment of X and TX were shown to be equivalent for a compression matrix T explicitly calculated as a function of the means and covariances of the given populations.

Strengthening of NiAl Matrix Composites

DTIC Science & Technology

1991-10-01

taille des sous-grains. Les donn&s obtenues pour une serie d’exp&iences indiquent que hit densitc de dislocations croit lorsque Ia fraction volumique de...electrical discharge 8. H. Fujita. T. Tabata , K. Yoshida. N. Summida and S. Katagiri, Japan J. appl. Phys. II, 1522 (1972).machining, dimpling and ion...milling does not intro- 9. H. Fujita and T. Tabata , Japan J. appl. Phys. 12, 471 duce dislocations into the matrix. (1973). * In order to obtain realistic

Invariant Imbedded T-Matrix Method for Axial Symmetric Hydrometeors with Extreme Aspect Ratios

NASA Technical Reports Server (NTRS)

Pelissier, Craig; Kuo, Kwo-Sen; Clune, Thomas; Adams, Ian; Munchak, Stephen

2017-01-01

The single-scattering properties (SSPs) of hydrometeors are the fundamental quantities for physics-based precipitation retrievals. Thus, efficient computation of their electromagnetic scattering is of great value. Whereas the semi-analytical T-Matrix methods are likely the most efficient for nonspherical hydrometeors with axial symmetry, they are not suitable for arbitrarily shaped hydrometeors absent of any significant symmetry, for which volume integral methods such as those based on Discrete Dipole Approximation (DDA) are required. Currently the two leading T-matrix methods are the Extended Boundary Condition Method (EBCM) and the Invariant Imbedding T-matrix Method incorporating Lorentz-Mie Separation of Variables (IITM+SOV). EBCM is known to outperform IITM+SOV for hydrometeors with modest aspect ratios. However, in cases when aspect ratios become extreme, such as needle-like particles with large height to diameter values, EBCM fails to converge. Such hydrometeors with extreme aspect ratios are known to be present in solid precipitation and their SSPs are required to model the radiative responses accurately. In these cases, IITM+SOV is shown to converge. An efficient, parallelized C++ implementation for both EBCM and IITM+SOV has been developed to conduct a performance comparison between EBCM, IITM+SOV, and DDSCAT (a popular implementation of DDA). We present the comparison results and discuss details. Our intent is to release the combined ECBM IITM+SOV software to the community under an open source license.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ray, L.; Hoffmann, G.W.; Thaler, R.M.

The treatment of the Coulomb interaction in the multiple scattering theories of Kerman-McManus-Thaler and Watson is examined in detail. By neglecting virtual Coulomb excitations, the lowest order Coulomb term in the Watson optical potential is shown to be a convolution of the point Coulomb interaction with the distributed nuclear charge, while the equivalent Kerman-McManus-Thaler Coulomb potential is obtained from an averaged, single-particle Coulombic T matrix. The Kerman-McManus-Thaler Coulomb potential is expressed as the Watson Coulomb term plus additional Coulomb-nuclear and Coulomb-Coulomb cross terms, and the omission of the extra terms in usual Kerman-McManus-Thaler applications leads to negative infinite total reactionmore » cross section predictions and incorrect pure Coulomb scattering limits. Approximations are presented which eliminate these anomalies. Using the two-potential formula, the full projectile-nucleus T matrix is separated into two terms, one resulting from the distributed nuclear charge and the other being a Coulomb distorted nuclear T matrix. It is shown that the error resulting from the omission of the Kerman-McManus-Thaler Coulomb terms is effectively removed when the pure Coulomb T matrix in Kerman-McManus-Thaler is replaced by the analogous quantity in the Watson approach. Using the various approximations, theoretical angular distributions are obtained for 800 MeV p+/sup 208/Pb elastic scattering and compared with experimental data.« less

Ultrahigh Ductility, High-Carbon Martensitic Steel

NASA Astrophysics Data System (ADS)

Qin, Shengwei; Liu, Yu; Hao, Qingguo; Zuo, Xunwei; Rong, Yonghua; Chen, Nailu

2016-10-01

Based on the proposed design idea of the anti-transformation-induced plasticity effect, both the additions of the Nb element and pretreatment of the normalization process as a novel quenching-partitioning-tempering (Q-P-T) were designed for Fe-0.63C-1.52Mn-1.49Si-0.62Cr-0.036Nb hot-rolled steel. This high-carbon Q-P-T martensitic steel exhibits a tensile strength of 1890 MPa and elongation of 29 pct accompanied by the excellent product of tensile and elongation of 55 GPa pct. The origin of ultrahigh ductility for high-carbon Q-P-T martensitic steel is revealed from two aspects: one is the softening of martensitic matrix due to both the depletion of carbon in the matensitic matrix during the Q-P-T process by partitioning of carbon from supersaturated martensite to retained austenite and the reduction of the dislocation density in a martensitic matrix by dislocation absorption by retained austenite effect during deformation, which significantly enhances the deformation ability of martensitic matrix; another is the high mechanical stability of considerable carbon-enriched retained austenite, which effectively reduces the formation of brittle twin-type martensite. This work verifies the correctness of the design idea of the anti-TRIP effect and makes the third-generation advanced high-strength steels extend to the field of high-carbon steels from low- and medium-carbon steels.

Invariant Imbedding T-Matrix Method for Axial Symmetric Hydrometeors with Extreme Aspect Ratios

NASA Astrophysics Data System (ADS)

Pelissier, C.; Clune, T.; Kuo, K. S.; Munchak, S. J.; Adams, I. S.

2017-12-01

The single-scattering properties (SSPs) of hydrometeors are the fundamental quantities for physics-based precipitation retrievals. Thus, efficient computation of their electromagnetic scattering is of great value. Whereas the semi-analytical T-Matrix methods are likely the most efficient for nonspherical hydrometeors with axial symmetry, they are not suitable for arbitrarily shaped hydrometeors absent of any significant symmetry, for which volume integral methods such as those based on Discrete Dipole Approximation (DDA) are required. Currently the two leading T-matrix methods are the Extended Boundary Condition Method (EBCM) and the Invariant Imbedding T-matrix Method incorporating Lorentz-Mie Separation of Variables (IITM+SOV). EBCM is known to outperform IITM+SOV for hydrometeors with modest aspect ratios. However, in cases when aspect ratios become extreme, such as needle-like particles with large height to diameter values, EBCM fails to converge. Such hydrometeors with extreme aspect ratios are known to be present in solid precipitation and their SSPs are required to model the radiative responses accurately. In these cases, IITM+SOV is shown to converge. An efficient, parallelized C++ implementation for both EBCM and IITM+SOV has been developed to conduct a performance comparison between EBCM, IITM+SOV, and DDSCAT (a popular implementation of DDA). We present the comparison results and discuss details. Our intent is to release the combined ECBM & IITM+SOV software to the community under an open source license.

T -matrix approach to quark-gluon plasma

NASA Astrophysics Data System (ADS)

Liu, Shuai Y. F.; Rapp, Ralf

2018-03-01

A self-consistent thermodynamic T -matrix approach is deployed to study the microscopic properties of the quark-gluon plasma (QGP), encompassing both light- and heavy-parton degrees of freedom in a unified framework. The starting point is a relativistic effective Hamiltonian with a universal color force. The input in-medium potential is quantitatively constrained by computing the heavy-quark (HQ) free energy from the static T -matrix and fitting it to pertinent lattice-QCD (lQCD) data. The corresponding T -matrix is then applied to compute the equation of state (EoS) of the QGP in a two-particle irreducible formalism, including the full off-shell properties of the selfconsistent single-parton spectral functions and their two-body interaction. In particular, the skeleton diagram functional is fully resummed to account for emerging bound and scattering states as the critical temperature is approached from above. We find that the solution satisfying three sets of lQCD data (EoS, HQ free energy, and quarkonium correlator ratios) is not unique. As limiting cases we discuss a weakly coupled solution, which features color potentials close to the free energy, relatively sharp quasiparticle spectral functions and weak hadronic resonances near Tc, and a strongly coupled solution with a strong color potential (much larger than the free energy), resulting in broad nonquasiparticle parton spectral functions and strong hadronic resonance states which dominate the EoS when approaching Tc.

Effectiveness of metal matrix and ceramic matrix composites as orbital debris shield materials

NASA Technical Reports Server (NTRS)

Mcgill, Preston B.; Mount, Angela R.

1992-01-01

The effectiveness of two metal matrix composites and one ceramic matrix material in defeating hypervelocity impacts at about 3.8 km/s are evaluated to determine the potential of these composites as spacecraft shield materials. The metal matrix composites investigated consist of SiC particles (70 percent by volume) in an aluminum matrix and Al2O3 particles (50 percent by volume) in an Al matrix. The ceramic composite consists of ZrB2 platelets in a ZrC matrix. Both the metal matrix and ceramic matrix composites are found to perform as well or better than 6061-T6 aluminum, which is presently used in the Whipple type bumper shield of Space Station Freedom. Test results indicate that the composites tested may have applications as micrometeoroid/orbital debris shield materials.

Molecular Optics Nonlinear Optical Processes in Organic and Polymeric Crystals and Films. Part 1

DTIC Science & Technology

1991-11-01

Cycio-Octateraene ........... .93 Figure3.3; THG Dispersion Curve for Cyclo-Octateraene .... ......... 94 Figure3.4; Bloch Vector in Pauli Matrix Space... Jung , P. and Hanggi, P, Phys. Rev. Lett. 61, 11 (1989) I [90] Guckenheimer, J. and Holmes, P., Nonlinear Oscillations, Dynamical Sys- tems, and...identity matrix and Pauli matrices. p(t) = 1(1 + fr(t)F * 5) (3.5.6) I where the 3-vector FF is the linear coefficients of the Pauli matrices and is

Time-Reversal Based Range Extension Technique for Ultra-Wideband (UWB) Sensors and Applications in Tactical Communications and Networking

DTIC Science & Technology

2009-01-16

i0ii ••• xNx ] T (5.11) Construct channel matrix H(NX+I)X(NP+I)’ where (•)<, denotes the entry in the i-th row and j-th column of the matrix or vector...should be minimized. The entries in x outside integration window constitute x/ as, X; = [ar0 • • E/Vjo-l xN,n+N,+l • • • xNx ] T (5.22) and the

Power-law expansion of the Universe from the bosonic Lorentzian type IIB matrix model

NASA Astrophysics Data System (ADS)

Ito, Yuta; Nishimura, Jun; Tsuchiya, Asato

2015-11-01

Recent studies on the Lorentzian version of the type IIB matrix model show that (3+1)D expanding universe emerges dynamically from (9+1)D space-time predicted by superstring theory. Here we study a bosonic matrix model obtained by omitting the fermionic matrices. With the adopted simplification and the usage of a large-scale parallel computer, we are able to perform Monte Carlo calculations with matrix size up to N = 512, which is twenty times larger than that used previously for the studies of the original model. When the matrix size is larger than some critical value N c ≃ 110, we find that (3+1)D expanding universe emerges dynamically with a clear large- N scaling property. Furthermore, the observed increase of the spatial extent with time t at sufficiently late times is consistent with a power-law behavior t 1/2, which is reminiscent of the expanding behavior of the Friedmann-Robertson-Walker universe in the radiation dominated era. We discuss possible implications of this result on the original supersymmetric model including fermionic matrices.

A Requirements Analysis for an Integrated Maintenance Information System Application Into Theater Air Control System Maintenance

DTIC Science & Technology

1994-09-01

133 v List of Tables Table Page 1. Line Item Changes in Proposed Ground TACS SSS Matrix...39 2. Percentage of Line Item Changes in Proposed SSS Matrix for G round T A C S...modified to meet Theater Air Control System requirements. The small amount of changes required to modify the aircraft matrix in order to satisfy ground

First step in developing a 3D biodegradable fibrin scaffold for an artificial ovary

PubMed Central

2013-01-01

Background Although transplantation of cryopreserved ovarian tissue is a promising approach to restore fertility in cancer patients, it is not advisable for women at risk of ovarian involvement due to the threat of reintroducing malignant cells. The aim of this study was therefore to find an alternative for these patients by development of an artificial ovary. Methods For construction of the artificial ovary matrix, we used a central composite design to investigate nine combinations of fibrinogen (mg/ml) and thrombin (IU/mL) (F/T): F1/T4, F12.5/T1, F12.5/T20, F25/T0.1, F25/T4, F25/T500, F50/T1, F50/T20 and F100/T4. From the first qualitative analyses (handling and matrix size), five combinations (F12.5/T1, F25/T4, F50/T20, F50/T1 and F100/T4) yielded positive results. They were further evaluated in order to assess fibrin matrix degradation and homogeneous cell encapsulation (density), survival and proliferation (Ki67), and atresia (TUNEL) before and after 7 days of in vitro culture. To determine the best compromise between maximizing the dynamic density (Y1) and minimizing the apoptosis rate (Y2), we used the desirability function approach. Results Two combinations (F12.5/T1 and F25/T4) showed greater distribution of cells before in vitro culture, reproducible degradation of the fibrin network and adequate support for isolated human ovarian stromal cells, with a high proportion of Ki67-positive cells. SEM analysis revealed a network of fibers with regular pores and healthy stromal cells after in vitro culture with both F/T combinations. Conclusion This study reports two optimal F/T combinations that allow survival and proliferation of isolated human ovarian cells. Further studies are required to determine if such a scaffold will also be a suitable environment for isolated ovarian follicles. PMID:24274108

Vibrio cholerae VpsT Regulates Matrix Production and Motility by Directly Sensing Cyclic di-GMP

DOE Office of Scientific and Technical Information (OSTI.GOV)

Krasteva, P.; Fong, J; Shikuma, N

2010-01-01

Microorganisms can switch from a planktonic, free-swimming life-style to a sessile, colonial state, called a biofilm, which confers resistance to environmental stress. Conversion between the motile and biofilm life-styles has been attributed to increased levels of the prokaryotic second messenger cyclic di-guanosine monophosphate (c-di-GMP), yet the signaling mechanisms mediating such a global switch are poorly understood. Here we show that the transcriptional regulator VpsT from Vibrio cholerae directly senses c-di-GMP to inversely control extracellular matrix production and motility, which identifies VpsT as a master regulator for biofilm formation. Rather than being regulated by phosphorylation, VpsT undergoes a change in oligomerizationmore » on c-di-GMP binding.« less

Top Quark Mass Measurement in the Lepton + Jets Channel Using a Matrix Element Method and \\textit{in situ} Jet Energy Calibration

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aaltonen, T.; /Helsinki Inst. of Phys.; Alvarez Gonzalez, B.

A precision measurement of the top quark mass m{sub t} is obtained using a sample of t{bar t} events from p{bar p} collisions at the Fermilab Tevatron with the CDF II detector. Selected events require an electron or muon, large missing transverse energy, and exactly four high-energy jets, at least one of which is tagged as coming from a b quark. A likelihood is calculated using a matrix element method with quasi-Monte Carlo integration taking into account finite detector resolution and jet mass effects. The event likelihood is a function of m{sub t} and a parameter {Delta}{sub JES} used tomore » calibrate the jet energy scale in situ. Using a total of 1087 events, a value of m{sub t} = 173.0 {+-} 1.2 GeV/c{sup 2} is measured.« less

Attenuation of endocrine-exocrine pancreatic communication in type 2 diabetes: pancreatic extracellular matrix ultrastructural abnormalities.

PubMed

Hayden, Melvin R; Patel, Kamlesh; Habibi, Javad; Gupta, Deepa; Tekwani, Seema S; Whaley-Connell, Adam; Sowers, James R

2008-01-01

Ultrastructural observations reveal a continuous interstitial matrix connection between the endocrine and exocrine pancreas, which is lost due to fibrosis in rodent models and humans with type 2 diabetes mellitus (T2DM). Widening of the islet-exocrine interface appears to result in loss of desmosomes and adherens junctions between islet and acinar cells and is associated with hypercellularity consisting of pericytes and inflammatory cells in T2DM pancreatic tissue. Organized fibrillar collagen was closely associated with pericytes, which are known to differentiate into myofibroblasts-pancreatic stellate cells. Of importance, some pericyte cellular processes traverse both the connecting islet-exocrine interface and the endoacinar interstitium of the exocrine pancreas. Loss of cellular paracrine communication and extracellular matrix remodeling fibrosis in young animal models and humans may result in a dysfunctional insulino-acinar-ductal-incretin gut hormone axis, resulting in pancreatic insufficiency and glucagon-like peptide deficiency, which are known to exist in prediabetes and overt T2DM in humans.

Attenuation of Endocrine-Exocrine Pancreatic Communication in Type 2 Diabetes: Pancreatic Extracellular Matrix Ultrastructural Abnormalities

PubMed Central

Hayden, Melvin R; Patel, Kamlesh; Habibi, Javad; Gupta, Deepa; Tekwani, Seema S.; Whaley-Connell, Adam; Sowers, James R.

2009-01-01

Ultrastructural observations reveal a continuous interstitial matrix connection between the endocrine and exocrine pancreas, which is lost due to fibrosis in rodent models and humans with type 2 diabetes mellitus (T2DM). Widening of the islet exocrine interface (IEI) appears to result in loss of desmosomes and adherens junctions between islet and acinar cells and is associated with hypercellularity consisting of pericytes and inflammatory cells in T2DM pancreatic tissue. Organized fibrillar collagen was closely associated with pericytes, which are known to differentiate into myofibroblasts – pancreatic stellate cells. Importantly, some pericyte cellular processes traverse both the connecting IEI and the endoacinar interstitium of the exocrine pancreas. Loss of cellular paracrine communication and extracellular matrix remodeling fibrosis in young animal models and humans may result in a dysfunctional insulino-acinar-ductal – incretin gut hormone axis resulting in pancreatic insufficiency and glucagon like peptide deficiency known to exist in prediabetes and overt T2DM in humans. PMID:19040593

Non-invasive detection of matrix-metalloproteinase activity in a mouse model of cerebral ischemia using multispectral optoacoustic tomography

NASA Astrophysics Data System (ADS)

Ni, Ruiqing; Vaas, Markus; Ren, Wuwei; Klohs, Jan

2018-02-01

Matrix metalloproteinases (MMPs) play important roles in the pathophysiology of cerebral ischemia. Here we visualized in vivo MMP activity in the transient middle cerebral artery occlusion (tMCAO) mouse model using multispectral optoacoustic imaging (MSOT) with a MMP-activatable probe. MSOT data was co-registered with structural magnetic resonance imaging (MRI) obtained at 7 T for localization of signal distribution. We demonstrated upregulated MMP signal within the focal ischemic lesion in the tMCAO mouse model using MSOT/MRI multimodal imaging. This convenient non-invasive method will allow repetitive measurement following the time course of MMP-lesion development in ischemic stroke animal model.

Differential expression of neuroleukin in osseous tissues and its involvement in mineralization during osteoblast differentiation

NASA Technical Reports Server (NTRS)

Zhi, J.; Sommerfeldt, D. W.; Rubin, C. T.; Hadjiargyrou, M.

2001-01-01

Osteoblast differentiation is a multistep process that involves critical spatial and temporal regulation of cellular processes marked by the presence of a large number of differentially expressed molecules. To identify key functional molecules, we used differential messenger RNA (mRNA) display and compared RNA populations isolated from the defined transition phases (proliferation, matrix formation, and mineralization) of the MC3T3-E1 osteoblast-like cell line. Using this approach, a complementary DNA (cDNA) fragment was isolated and identified as neuroleukin (NLK), a multifunctional cytokine also known as autocrine motility factor (AMF), phosphoglucose isomerase (PGI; phosphohexose isomerase [PHI]), and maturation factor (MF). Northern analysis showed NLK temporal expression during MC3T3-E1 cell differentiation with a 3.5-fold increase during matrix formation and mineralization. Immunocytochemical studies revealed the presence of NLK in MC3T3-E1 cells as well as in the surrounding matrix, consistent with a secreted molecule. In contrast, the NLK receptor protein was detected primarily on the cell membrane. In subsequent studies, a high level of NLK expression was identified in osteoblasts and superficial articular chondrocytes in bone of 1-, 4-, and 8-month-old normal mice, as well as in fibroblasts, proliferating chondrocytes, and osteoblasts within a fracture callus. However, NLK was not evident in hypertrophic chondrocytes or osteocytes. In addition, treatment of MC3T3 cells with 6-phosphogluconic acid (6PGA; a NLK inhibitor) resulted in diminishing alkaline phosphatase (ALP) activity and mineralization in MC3T3-E1 cells, especially during the matrix formation stage of differentiating cells. Taken together, these data show specific expression of NLK in discrete populations of bone and cartilage cells and suggest a possible role for this secreted protein in bone development and regeneration.

Initial test of a T9-like P300-based speller by an ALS patient

NASA Astrophysics Data System (ADS)

Ron-Angevin, R.; Varona-Moya, S.; da Silva-Sauer, L.

2015-08-01

Objective. Visual P300-based brain-computer interface spellers offer a useful communication channel for locked-in patients, who are completely dependent in their daily lives. One of the research goals for these systems is to achieve greater communication rates by means of modifying some features of their interfaces, e.g., reducing the matrix size. However, such modifications may not work well with disabled end-users, such as patients of amyotrophic lateral sclerosis (ALS), due to a supposed reduction of their cognitive resources. The purpose of the present study was to provide a proof of concept that ALS patients could efficiently use a P300-based speller with a 4 × 3 symbol matrix based on the T9 interface developed for mobile phones. Approach. We conducted an experiment with a sample of 11 able-bodied participants and one locked-in patient with ALS. All participants tested our T9-like visual P300-based speller and also two different 7 × 6 matrix spellers based on Farwell and Donchin’s classic proposal—one of them included a word predictor system like the T9-like speller did. Main results. The performance analyses indicated that the locked-in patient benefited from using a reduced matrix size as much as healthy users did, spelling words almost 1.6 times faster and equally accurately when using the T9-like speller than when using the alternative spellers. Significance. Due to counting on only one locked-in patient, the current work constitutes a feasibility study. The actual usability of systems such as the one proposed in this paper should be determined by means of studies with a greater number of end-users in real-life conditions.

Development of a Three-Dimensional Bone-Like Construct in a Soft Self-Assembling Peptide Matrix

PubMed Central

Marí-Buyé, Núria; Luque, Tomás; Navajas, Daniel

2013-01-01

This work describes the development of a three-dimensional (3D) model of osteogenesis using mouse preosteoblastic MC3T3-E1 cells and a soft synthetic matrix made out of self-assembling peptide nanofibers. By adjusting the matrix stiffness to very low values (around 120 Pa), cells were found to migrate within the matrix, interact forming a cell–cell network, and create a contracted and stiffer structure. Interestingly, during this process, cells spontaneously upregulate the expression of bone-related proteins such as collagen type I, bone sialoprotein, and osteocalcin, indicating that the 3D environment enhances their osteogenic potential. However, unlike MC3T3-E1 cultures in 2D, the addition of dexamethasone is required to acquire a final mature phenotype characterized by features such as matrix mineralization. Moreover, a slight increase in the hydrogel stiffness (threefold) or the addition of a cell contractility inhibitor (Rho kinase inhibitor) abrogates cell elongation, migration, and 3D culture contraction. However, this mechanical inhibition does not seem to noticeably affect the osteogenic process, at least at early culture times. This 3D bone model intends to emphasize cell–cell interactions, which have a critical role during tissue formation, by using a compliant unrestricted synthetic matrix. PMID:23157379

Shrinkage covariance matrix approach based on robust trimmed mean in gene sets detection

NASA Astrophysics Data System (ADS)

Karjanto, Suryaefiza; Ramli, Norazan Mohamed; Ghani, Nor Azura Md; Aripin, Rasimah; Yusop, Noorezatty Mohd

2015-02-01

Microarray involves of placing an orderly arrangement of thousands of gene sequences in a grid on a suitable surface. The technology has made a novelty discovery since its development and obtained an increasing attention among researchers. The widespread of microarray technology is largely due to its ability to perform simultaneous analysis of thousands of genes in a massively parallel manner in one experiment. Hence, it provides valuable knowledge on gene interaction and function. The microarray data set typically consists of tens of thousands of genes (variables) from just dozens of samples due to various constraints. Therefore, the sample covariance matrix in Hotelling's T2 statistic is not positive definite and become singular, thus it cannot be inverted. In this research, the Hotelling's T2 statistic is combined with a shrinkage approach as an alternative estimation to estimate the covariance matrix to detect significant gene sets. The use of shrinkage covariance matrix overcomes the singularity problem by converting an unbiased to an improved biased estimator of covariance matrix. Robust trimmed mean is integrated into the shrinkage matrix to reduce the influence of outliers and consequently increases its efficiency. The performance of the proposed method is measured using several simulation designs. The results are expected to outperform existing techniques in many tested conditions.

UDU/T/ covariance factorization for Kalman filtering

NASA Technical Reports Server (NTRS)

Thornton, C. L.; Bierman, G. J.

1980-01-01

There has been strong motivation to produce numerically stable formulations of the Kalman filter algorithms because it has long been known that the original discrete-time Kalman formulas are numerically unreliable. Numerical instability can be avoided by propagating certain factors of the estimate error covariance matrix rather than the covariance matrix itself. This paper documents filter algorithms that correspond to the covariance factorization P = UDU(T), where U is a unit upper triangular matrix and D is diagonal. Emphasis is on computational efficiency and numerical stability, since these properties are of key importance in real-time filter applications. The history of square-root and U-D covariance filters is reviewed. Simple examples are given to illustrate the numerical inadequacy of the Kalman covariance filter algorithms; these examples show how factorization techniques can give improved computational reliability.

SU-F-R-35: Repeatability of Texture Features in T1- and T2-Weighted MR Images

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mahon, R; Weiss, E; Karki, K

Purpose: To evaluate repeatability of lung tumor texture features from inspiration/expiration MR image pairs for potential use in patient specific care models and applications. Repeatability is a desirable and necessary characteristic of features included in such models. Methods: T1-weighted Volumetric Interpolation Breath-Hold Examination (VIBE) and/or T2-weighted MRI scans were acquired for 15 patients with non-small cell lung cancer before and during radiotherapy for a total of 32 and 34 same session inspiration-expiration breath-hold image pairs respectively. Bias correction was applied to the VIBE (VIBE-BC) and T2-weighted (T2-BC) images. Fifty-nine texture features at five wavelet decomposition ratios were extracted from themore » delineated primary tumor including: histogram(HIST), gray level co-occurrence matrix(GLCM), gray level run length matrix(GLRLM), gray level size zone matrix(GLSZM), and neighborhood gray tone different matrix (NGTDM) based features. Repeatability of the texture features for VIBE, VIBE-BC, T2-weighted, and T2-BC image pairs was evaluated by the concordance correlation coefficient (CCC) between corresponding image pairs, with a value greater than 0.90 indicating repeatability. Results: For the VIBE image pairs, the percentage of repeatable texture features by wavelet ratio was between 20% and 24% of the 59 extracted features; the T2-weighted image pairs exhibited repeatability in the range of 44–49%. The percentage dropped to 10–20% for the VIBE-BC images, and 12–14% for the T2-BC images. In addition, five texture features were found to be repeatable in all four image sets including two GLRLM, two GLZSM, and one NGTDN features. No single texture feature category was repeatable among all three image types; however, certain categories performed more consistently on a per image type basis. Conclusion: We identified repeatable texture features on T1- and T2-weighted MRI scans. These texture features should be further investigated for use in specific applications such as tissue classification and changes during radiation therapy utilizing a standard imaging protocol. Authors have the following disclosures: a research agreement with Philips Medical systems (Hugo, Weiss), a license agreement with Varian Medical Systems (Hugo, Weiss), research grants from the National Institute of Health (Hugo, Weiss), UpToDate royalties (Weiss), and none(Mahon, Ford, Karki). Authors have no potential conflicts of interest to disclose.« less

Toll-Like Receptor 4 Mediates Hemorrhagic Transformation After Delayed Tissue Plasminogen Activator Administration in In Situ Thromboembolic Stroke.

PubMed

García-Culebras, Alicia; Palma-Tortosa, Sara; Moraga, Ana; García-Yébenes, Isaac; Durán-Laforet, Violeta; Cuartero, Maria I; de la Parra, Juan; Barrios-Muñoz, Ana L; Díaz-Guzmán, Jaime; Pradillo, Jesús M; Moro, María A; Lizasoain, Ignacio

2017-06-01

Hemorrhagic transformation is the main complication of revascularization therapies after stroke. Toll-like receptor 4 (TLR4) is implicated in cerebral damage and inflammation in stroke. This study was designed to determine the role of TLR4 in hemorrhagic transformation development after tissue plasminogen activator (tPA) administration. Mice expressing (TLR4 +/+ ) or lacking functional TLR4 (TLR4 - /- ) were subjected to middle cerebral artery occlusion using an in situ thromboembolic model by thrombin injection into the middle cerebral artery, and tPA (10 mg/kg) was administered 20 minutes or 3 hours after ischemia. Infarct size, hemorrhages, IgG extravasation, matrix metalloproteinase 9 expression, and neutrophil infiltration were assessed 24 hours after ischemia. In TLR4 +/+ , early reperfusion (tPA at 20 minutes) resulted infarct volume, whereas late recanalization (tPA at 3 hours) did not modify lesion size and increased the rate of the most severe hemorrhages. In TLR4 - /- mice, both early and late reperfusion did not modify lesion size. Importantly, late tPA administration did not result in worse hemorrhages and in an increased bleeding area as occurred in TLR4 +/+ group. In TLR4 - /- animals, late reperfusion produced a lesser increase in matrix metalloproteinase 9 expression when compared with TLR4 +/+ animals. Our results demonstrate TLR4 involvement in hemorrhagic transformation induced by delayed tPA administration, very likely by increasing matrix metalloproteinase 9 expression. © 2017 American Heart Association, Inc.

Singularly Perturbed Equations in the Critical Case.

DTIC Science & Technology

1980-02-01

asymptotic properties of the differential equation (1) in the noncritical case (all ReXi (t) ɘ) . We will consider the critical case (k 0) ; the...the inequality (3), that is, ReXi (t,a) < 0 (58) The matrix ca(t,a) , consisting of the eigenvectors corresponding to w 0 , now has the form I (P -(t

Generating double knockout mice to model genetic intervention for diabetic cardiomyopathy in humans.

PubMed

Chavali, Vishalakshi; Nandi, Shyam Sundar; Singh, Shree Ram; Mishra, Paras Kumar

2014-01-01

Diabetes is a rapidly increasing disease that enhances the chances of heart failure twofold to fourfold (as compared to age and sex matched nondiabetics) and becomes a leading cause of morbidity and mortality. There are two broad classifications of diabetes: type1 diabetes (T1D) and type2 diabetes (T2D). Several mice models mimic both T1D and T2D in humans. However, the genetic intervention to ameliorate diabetic cardiomyopathy in these mice often requires creating double knockout (DKO). In order to assess the therapeutic potential of a gene, that specific gene is either overexpressed (transgenic expression) or abrogated (knockout) in the diabetic mice. If the genetic mice model for diabetes is used, it is necessary to create DKO with transgenic/knockout of the target gene to investigate the specific role of that gene in pathological cardiac remodeling in diabetics. One of the important genes involved in extracellular matrix (ECM) remodeling in diabetes is matrix metalloproteinase-9 (Mmp9). Mmp9 is a collagenase that remains latent in healthy hearts but induced in diabetic hearts. Activated Mmp9 degrades extracellular matrix (ECM) and increases matrix turnover causing cardiac fibrosis that leads to heart failure. Insulin2 mutant (Ins2+/-) Akita is a genetic model for T1D that becomes diabetic spontaneously at the age of 3-4 weeks and show robust hyperglycemia at the age of 10-12 weeks. It is a chronic model of T1D. In Ins2+/- Akita, Mmp9 is induced. To investigate the specific role of Mmp9 in diabetic hearts, it is necessary to create diabetic mice where Mmp9 gene is deleted. Here, we describe the method to generate Ins2+/-/Mmp9-/- (DKO) mice to determine whether the abrogation of Mmp9 ameliorates diabetic cardiomyopathy.

Association between matrix metalloproteinase 2 (MMP2) promoter polymorphisms and the susceptibility to non-Hodgkin's lymphoma in Egyptians.

PubMed

Gouda, Heba Mahmoud; Khorshied, Mervat Mamdooh; El Sissy, Maha Hamdi; Shaheen, Iman Abdel Mohsen; Mohsen, Mohsen Mokhtar Abdel

2014-08-01

Matrix metalloproteinases (MMPs) are zinc-dependent endopeptidases capable of extracellular matrix degradation. MMP2 is the key molecule that control invasion, tumor growth, and metastasis, and has been associated with poor prognosis in several tumors. Several epidemiological studies have focused on the associations between MMP2 promoter polymorphisms and cancer susceptibility; however, little is known about their role in hematological malignancies. The present study aimed to investigate the association of MMP2 -735C/T and -1306C/T promoter polymorphisms with B-NHL susceptibility and their clinicopathological characteristics. The study included 100 B-NHL patients and 100 healthy controls. Genotyping of MMP2 -735C/T and MMP2 -1306C/T was done by polymerase chain reaction restricted fragment length polymorphism (PCR-RFLP) technique. MMP2 -735C/T heteromutant genotype (CT) was detected in 23 % of patients, and the homomutant genotype (TT) was detected in 7 % of patients. The polymorphic allele, T allele, was associated with susceptibility to B-NHL (OR = 2.8:95 %CI = 1.48-5.28). For MMP2 -1306C/T, the frequencies of the polymorphic variants were 5 % for the heteromutant genotype (CT) and 3 % for the homomutant genotype (TT). The polymorphic allele, T allele, conferred almost fourfold increased risk of B-NHL (OR = 3.8, 95 %CI = 1.05-13.9), and the risk elevated to be almost eight folds when confined to diffuse large B-cell lymphoma (DLBCL) (OR = 7.9, 95 %CI = 1.67-32.27). MMP2 -735C/T polymorphic genotypes were correlated with advanced clinical stages of the disease (stages III and IV). In conclusion, the study revealed that the variant alleles of MMP2 -735C/T and MMP2 -1306C/T can be considered as molecular risk factors for B-NHL among Egyptians.

Cutting edge: high molecular weight hyaluronan promotes the suppressive effects of CD4+CD25+ regulatory T cells.

PubMed

Bollyky, Paul L; Lord, James D; Masewicz, Susan A; Evanko, Stephen P; Buckner, Jane H; Wight, Thomas N; Nepom, Gerald T

2007-07-15

Hyaluronan is a glycosaminoglycan present in the extracellular matrix. When hyaluronan is degraded during infection and injury, low m.w. forms are generated whose interactions influence inflammation and angiogenesis. Intact high m.w. hyaluronan, conversely, conveys anti-inflammatory signals. We demonstrate that high m.w. hyaluronan enhances human CD4(+)CD25(+) regulatory T cell functional suppression of responder cell proliferation, whereas low m.w. hyaluronan does not. High m.w. hyaluronan also up-regulates the transcription factor FOXP3 on CD4(+)CD25(+) regulatory T cells. These effects are only seen with activated CD4(+)CD25(+) regulatory T cells and are associated with the expression of CD44 isomers that more highly bind high m.w. hyaluronan. At higher concentrations, high m.w. hyaluronan also has direct suppressive effects on T cells. We propose that the state of HA in the matrix environment provides contextual cues to CD4(+)CD25(+) regulatory T cells and T cells, thereby providing a link between the innate inflammatory network and the regulation of adaptive immune responses.

A novel anti-EMMPRIN function-blocking antibody reduces T cell proliferation and neurotoxicity: relevance to multiple sclerosis

PubMed Central

2012-01-01

Background Extracellular matrix metalloproteinase inducer (EMMPRIN; CD147, basigin) is an inducer of the expression of several matrix metalloproteinases (MMPs). We reported previously that blocking EMMPRIN activity reduced neuroinflammation and severity of disease in an animal model of multiple sclerosis (MS), experimental autoimmune encephalomyelitis (EAE). Methods To improve upon EMMPRIN blockade, and to help unravel the biological functions of EMMPRIN in inflammatory disorders, we have developed several anti-EMMPRIN monoclonal antibodies. Results Of these monoclonal antibodies, a particular one, clone 10, was efficient in binding mouse and human cells using several methods of detection. The specificity of clone 10 was demonstrated by its lack of staining of EMMPRIN-null embryos compared to heterozygous and wild-type mouse samples. Functionally, human T cells activated with anti-CD3 and anti-CD28 elevated their expression of EMMPRIN and the treatment of these T cells with clone 10 resulted in decreased proliferation and matrix metalloproteinase- 9 (MMP-9) production. Activated human T cells were toxic to human neurons in culture and clone 10 pretreatment reduced T cell cytotoxicity correspondent with decrease of granzyme B levels within T cells. In vivo, EAE mice treated with clone 10 had a markedly reduced disease score compared to mice treated with IgM isotype control. Conclusions We have produced a novel anti-EMMPRIN monoclonal antibody that blocks several aspects of T cell activity, thus highlighting the multiple roles of EMMPRIN in T cell biology. Moreover, clone 10 reduces EAE scores in mice compared to controls, and has activity on human cells, potentially allowing for the testing of anti-EMMPRIN treatment not only in EAE, but conceivably also in MS. PMID:22480370

A novel anti-EMMPRIN function-blocking antibody reduces T cell proliferation and neurotoxicity: relevance to multiple sclerosis.

PubMed

Agrawal, Smriti M; Silva, Claudia; Wang, Janet; Tong, Jade Pui-Wai; Yong, V Wee

2012-04-05

Extracellular matrix metalloproteinase inducer (EMMPRIN; CD147, basigin) is an inducer of the expression of several matrix metalloproteinases (MMPs). We reported previously that blocking EMMPRIN activity reduced neuroinflammation and severity of disease in an animal model of multiple sclerosis (MS), experimental autoimmune encephalomyelitis (EAE). To improve upon EMMPRIN blockade, and to help unravel the biological functions of EMMPRIN in inflammatory disorders, we have developed several anti-EMMPRIN monoclonal antibodies. Of these monoclonal antibodies, a particular one, clone 10, was efficient in binding mouse and human cells using several methods of detection. The specificity of clone 10 was demonstrated by its lack of staining of EMMPRIN-null embryos compared to heterozygous and wild-type mouse samples. Functionally, human T cells activated with anti-CD3 and anti-CD28 elevated their expression of EMMPRIN and the treatment of these T cells with clone 10 resulted in decreased proliferation and matrix metalloproteinase- 9 (MMP-9) production. Activated human T cells were toxic to human neurons in culture and clone 10 pretreatment reduced T cell cytotoxicity correspondent with decrease of granzyme B levels within T cells. In vivo, EAE mice treated with clone 10 had a markedly reduced disease score compared to mice treated with IgM isotype control. We have produced a novel anti-EMMPRIN monoclonal antibody that blocks several aspects of T cell activity, thus highlighting the multiple roles of EMMPRIN in T cell biology. Moreover, clone 10 reduces EAE scores in mice compared to controls, and has activity on human cells, potentially allowing for the testing of anti-EMMPRIN treatment not only in EAE, but conceivably also in MS.

Alterations in intervertebral disc composition, matrix homeostasis and biomechanical behavior in the UCD-T2DM rat model of type 2 diabetes

PubMed Central

Fields, Aaron J.; Berg-Johansen, Britta; Metz, Lionel N.; Miller, Stephanie; La, Brandan; Liebenberg, Ellen C.; Coughlin, Dezba G.; Graham, James L.; Stanhope, Kimber L.; Havel, Peter J.; Lotz, Jeffrey C.

2015-01-01

Type 2 diabetes (T2D) adversely affects many tissues, and the greater incidence of discogenic low back pain among diabetic patients suggests that the intervertebral disc is affected too. Using a rat model of polygenic obese T2D, we demonstrate that diabetes compromises several aspects of disc composition, matrix homeostasis and biomechanical behavior. Coccygeal motion segments were harvested from 6-month-old lean Sprague-Dawley rats, obese Sprague-Dawley rats, and diabetic obese UCD-T2DM rats (diabetic for 69 ± 7 days). Findings indicated that diabetes but not obesity reduced disc glycosaminoglycan and water contents, and these degenerative changes correlated with increased vertebral endplate thickness and decreased endplate porosity, and with higher levels of the advanced glycation end-product (AGE) pentosidine. Consistent with their diminished glycosaminoglycan and water contents and their higher AGE levels, discs from diabetic rats were stiffer and exhibited less creep when compressed. At the matrix level, elevated expression of hypoxia-inducible genes and catabolic markers in the discs from diabetic rats coincided with increased oxidative stress and greater interactions between AGEs and one of their receptors (RAGE). Taken together, these findings indicate that endplate sclerosis, increased oxidative stress and AGE/RAGE-mediated interactions could be important factors for explaining the greater incidence of disc pathology in T2D. PMID:25641259

Life Prediction of High Temperature Polymer Matrix Composites for Aircraft Engine and Airframe Applications

DTIC Science & Technology

2008-09-01

R.d6 *RVE V 0 , aVfd(t) or< d22(t)= ir =S(t) (18) RLR Similarly, it can be shown that the component of the damage in the X3-direction...at time t is. d33(t) = 2]aSm 20.d(t).R.dd V YRVE V 0 oVfdlt) (19) RLR It is evident from equations (18) and (19) that d22 =dyi =S(t) and

Use of Collagen Matrix for Augmentation of the Peri-implant Soft Tissue at the Time of Immediate Implant Placement.

PubMed

Zafiropoulos, Gregor-Georg; John, Gordon

2017-05-01

The aim of this study was to determine the treatment outcome of the use of a porcine monolayer collagen matrix (mCM) to augment peri-implant soft tissue in conjunction with immediate implant placement as an alternative to patient's own connective tissue. A total of 27 implants were placed immediately in 27 patients (14 males and 13 females, with a mean age of 52.2 years) with simultaneous augmentation of the soft tissue by the use of a mCM. The patients were randomly divided into two groups: Group I: An envelope flap was created and mCM was left coronally uncovered, and group II: A coronally repositioned flap was created and the mCM was covered by the mucosa. Soft-tissue thickness (STTh) was measured at the time of surgery (T0) and 6 months postoperatively (T1) using a customized stent. Cone beam computed tomographies (CBCTs) were taken from 12 representative cases at T1. A stringent plaque control regimen was enforced in all the patients during the 6-month observation period. Mean STTh change was similar in both groups (0.7 ± 0.2 and 0.7 ± 0.1 mm in groups I and II respectively). The comparison of STTh between T0 and T1 showed a statistically significant increase of soft tissue in both groups I and II as well as in the total examined population (p < 0.001). The STTh change as well as matrix thickness loss were comparable in both groups (p > 0.05). The evaluation of the CBCTs did not show any signs of resorption of the buccal bone plate. Within the limitations of this study, it could be concluded that the collagen matrix used in conjunction with immediate implant placement leads to an increased thickness of peri-implant soft tissue independent of the flap creation technique and could be an alternative to connective tissue graft. The collagen matrix used seems to be a good alternative to patient's own connective tissue and could be used for the soft tissue augmentation around dental implants.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pisarski, Robert D.; Skokov, Vladimir V.

Previously, a matrix model of the region near the transition temperature, in the “semi”quark gluon plasma, was developed for the theory of SU(3) gluons without quarks. In this paper we develop a chiral matrix model applicable to QCD by including dynamical quarks with 2+1 flavors. This requires adding a nonet of scalar fields, with both parities, and coupling these to quarks through a Yukawa coupling, y. Treating the scalar fields in mean field approximation, the effective Lagrangian is computed by integrating out quarks to one loop order. As is standard, the potential for the scalar fields is chosen to bemore » symmetric under the flavor symmetry of SU (3) L × SU(3) R × Z (3) A , except for a term linear in the current quark mass, m qk . In addition, at a nonzero temperature T it is necessary to add a new term, ~ m qk T 2 . The parameters of the gluon part of the matrix model are identical to those for the pure glue theory without quarks. The parameters in the chiral matrix model are fixed by the values, at zero temperature, of the pion decay constant and the masses of the pions, kaons, η , and η' . The temperature for the chiral crossover at T$χ$ = 155 MeV is determined by adjusting the Yukawa coupling y . We find reasonable agreement with the results of numerical simulations on the lattice for the pressure and related quantities. In the chiral limit, besides the divergence in the chiral susceptibility there is also a milder divergence in the susceptibility between the Polyakov loop and the chiral order parameter, with critical exponent β $-$ 1 . We compute derivatives with respect to a quark chemical potential to determine the susceptibilities for baryon number, the $χ$ 2n . Especially sensitive tests are provided by $χ$ 4 $-$ $χ$ 2 and by $χ$ 6 , which changes in sign about T$χ$ . In conclusion, the behavior of the susceptibilities in the chiral matrix model strongly suggests that as the temperature increases from T$χ$ , that the transition to deconfinement is significantly quicker than indicated by the measurements of the (renormalized) Polyakov loop on the lattice.« less

Matrix effect and optimization of LC-MSn determination of trachylobane-360 in mice blood.

PubMed

Pita, João Carlos Lima Rodrigues; Gomes, Isis Fernandes; Dos Santos, Socrates Golzio; Tavares, Josean Fechine; da Silva, Marcelo Sobral; Diniz, Margareth de Fátima Formiga Melo; Sobral, Marianna Vieira

2014-11-01

Xylopia langsdorffiana A. St.-Hil. & Tul. (Annonaceae) is popularly known as "pimenteira-da-terra". Various constituents have been isolated from this species, including diterpenes, such as 8(17), 12E, 14-labdatrien-18-oic acid, ent-atisan-7α, 16α-diol (xylodiol), ent-7α-hydroxytrachyloban-18-oic acid (trachylobane-318) and ent-7α-acetoxytrachyloban-18-oic acid, a crystalline solid with a molecular weight of 360 and molecular formula of C22H32O4 (trachylobane-360). When administered intraperitoneally to mice, trachylobane-360 (T-360) significantly inhibits growth of the solid tumor sarcoma 180 transplanted in mice, without causing alterations in biochemical, hematological and histopathological parameters that are frequently associated with the clinical use of antineoplastic. Furthermore, this diterpene blocks voltage-dependent calcium channels (Cav), showing spasmolytic activity. The present study shows that variables such as extraction solvent (methanol, acetonitrile and chloroform), centrifugation force (1000, 7000 and 14,000×g), and centrifugation time (5, 15 and 25min), are important in the liquid-liquid extraction of T-360 from male Swiss mice blood in HPLC-MSn studies. The study confirms matrix influence on recovery and detection of T-360. The recovery for T-360 was 37.02% using chloroform as better extractor solvent, while centrifuged at 14,000×g for 15min demonstrated the importance of the parameters chosen for the extraction/recovery process of analyte. The effect of mice blood matrix for T-360 was -51.23%. This method was optimized by repeating the extraction procedure and acidification of samples. These conditions were essential in increasing recovery (49.47%) by decreasing the matrix effect (-37.60%). The efficiency of the process, after optimization with two extractions and acidification, increased by 14.19% when compared to the initial method, from 18.05% to 32.24%. According to Marchi et al. (2010), the matrix effect does not necessarily need to be reduced or eliminated, but it does need to be identified and quantified. Therefore, these findings are essential for the subsequent evaluation of the pharmacokinetic parameters of this promising natural product. Copyright © 2014 Elsevier B.V. All rights reserved.

Understanding the role of saliva in aroma release from wine by using static and dynamic headspace conditions.

PubMed

Muñoz-González, Carolina; Feron, Gilles; Guichard, Elisabeth; Rodríguez-Bencomo, J José; Martín-Álvarez, Pedro J; Moreno-Arribas, M Victoria; Pozo-Bayón, M Ángeles

2014-08-20

The aim of this work was to determine the role of saliva in wine aroma release by using static and dynamic headspace conditions. In the latter conditions, two different sampling points (t = 0 and t = 10 min) corresponding with oral (25.5 °C) and postoral phases (36 °C) were monitored. Both methodologies were applied to reconstituted dearomatized white and red wines with different nonvolatile wine matrix compositions and a synthetic wine (without matrix effect). All of the wines had the same ethanol concentration and were spiked with a mixture of 45 aroma compounds covering a wide range of physicochemical characteristics at typical wine concentrations. Two types of saliva (human and artificial) or control samples (water) were added to the wines. The adequacy of the two headspace methodologies for the purposes of the study (repeatability, linear ranges, determination coefficients, etc.) was previously determined. After application of different chemometric analysis (ANOVA, LSD, PCA), results showed a significant effect of saliva on aroma release dependent on saliva type (differences between artificial and human) and on wine matrix using static headspace conditions. Red wines were more affected than white and synthetic wines by saliva, specifically human saliva, which provoked a reduction in aroma release for most of the assayed aroma compounds independent of their chemical structure. The application of dynamic headspace conditions using a saliva bioreactor at the two different sampling points (t = 0 and t = 10 min) showed a lesser but significant effect of saliva than matrix composition and a high influence of temperature (oral and postoral phases) on aroma release.

Circulating matrix modulators (MMP-9 and TIMP-1) and their association with severity of diabetic retinopathy.

PubMed

Jayashree, Kuppuswami; Yasir, Md; Senthilkumar, Gandhipuram Periyasamy; Ramesh Babu, K; Mehalingam, Vadivelan; Mohanraj, Palani Selvam

2018-05-05

Diabetic Retinopathy (DR) is the leading cause of vision loss in the working age population. Matrix metalloproteinase-9 (MMP-9) and tissue inhibitor of metalloproteinase-1 (TIMP-1), are molecules involved in extracellular tissue matrix remodelling. They are implicated in the loss of retinal tissue integrity, a major cause of DR, that leads to retinal tissue degradation and apoptosis. This study is therefore, conducted to compare the serum levels of MMP-9 and TIMP-1 in T2DM patients without and with retinopathy, and to evaluate their association with the severity of DR. Our study comprised of 2 groups of 41 each. Group A (cases) included T2DM patients with retinopathy and Group B (controls) included T2DM patients without retinopathy. Routine parameters, mainly, fasting blood glucose, and lipid profile were measured using autoanalyzer. Serum MMP-9, TIMP-1, and insulin levels were assessed using ELISA method. Statistically significant increase in the levels of MMP-9, insulin, fasting blood glucose and lipid profile were observed in the serum of T2DM patients with retinopathy, as compared with those without retinopathy. These results help to conclude that rise in MMP-9, and associated serum markers promote disease progress in DR. These findings suggest that the elevations of our study markers in the serum of the type 2 diabetic patients with retinopathy, as compared to those without retinopathy, play important roles in aggravating tissue matrix degradation, supporting DR disease progression. Copyright © 2018. Published by Elsevier Ltd.

Quantifying economic fluctuations by adapting methods of statistical physics

NASA Astrophysics Data System (ADS)

Plerou, Vasiliki

2001-09-01

The first focus of this thesis is the investigation of cross-correlations between the price fluctuations of different stocks using the conceptual framework of random matrix theory (RMT), developed in physics to describe the statistical properties of energy-level spectra of complex nuclei. RMT makes predictions for the statistical properties of matrices that are universal, i.e., do not depend on the interactions between the elements comprising the system. In physical systems, deviations from the predictions of RMT provide clues regarding the mechanisms controlling the dynamics of a given system so this framework is of potential value if applied to economic systems. This thesis compares the statistics of cross-correlation matrix C-whose elements Cij are the correlation coefficients of price fluctuations of stock i and j-against the ``null hypothesis'' of a random matrix having the same symmetry properties. It is shown that comparison of the eigenvalue statistics of C with RMT results can be used to distinguish random and non-random parts of C. The non-random part of C which deviates from RMT results, provides information regarding genuine cross-correlations between stocks. The interpretations and potential practical utility of these deviations are also investigated. The second focus is the characterization of the dynamics of stock price fluctuations. The statistical properties of the changes G Δt in price over a time interval Δ t are quantified and the statistical relation between G Δt and the trading activity-measured by the number of transactions NΔ t in the interval Δt is investigated. The statistical properties of the volatility, i.e., the time dependent standard deviation of price fluctuations, is related to two microscopic quantities: NΔt and the variance W2Dt of the price changes for all transactions in the interval Δ t. In addition, the statistical relationship between G Δt and the number of shares QΔt traded in Δ t is investigated.

Demographic matrix model for informing swallow-wort (Vincetoxicum spp.) biological control

USDA-ARS?s Scientific Manuscript database

Demographic matrix modeling of plant populations can be a powerful tool to identify key life stage transitions that contribute the most to population growth of an invasive plant and hence should be targeted for disruption (weak links) by biological control and/or other control tactics. Therefore, t...

Role of selenium-containing proteins in T cell and macrophage function

PubMed Central

Carlson, Bradley A.; Yoo, Min-Hyuk; Shrimali, Rajeev K.; Irons, Robert; Gladyshev, Vadim N.; Hatfield, Dolph L.; Park, Jin Mo

2011-01-01

Synopsis Selenium has been known for many years to have a role in boosting immune function, but the manner in which this element acts at the molecular level in host defense and inflammatory diseases is poorly understood. To elucidate the role of selenium-containing proteins in immune function, we knocked out the expression of this protein class in T cells or macrophages of mice by targeting the removal of the selenocysteine tRNA gene using loxP-Cre technology. Mice with selenoprotein-less T cells manifested reduced pools of mature and functional T cells in lymphoid tissues and an impairment in T cell-dependent antibody responses. Furthermore, selenoprotein deficiency in T cells led to an inability of these cells to suppress reactive oxygen species (ROS) production, which in turn affected their ability to proliferate in response to T cell receptor stimulation. Selenoprotein-less macrophages, on the other hand, manifested mostly normal inflammatory responses, but this deficiency resulted in an altered regulation in extracellular matrix-related gene expression and a diminished migration of macrophages in a protein gel matrix. These observations provided novel insights into the role of selenoproteins in immune function and tissue homeostasis. PMID:20576203

[3T magnetic resonance T2 mapping for evaluation of cartilage repair after matrix-associated autologous chondrocyte transplantation].

PubMed

Zhang, Jun; Xu, Xian; Li, Xue; Chen, Min; Dong, Tian-Ming; Zuo, Pan-Li; An, Ning-Yu

2015-01-01

To assess the value of magnetic resonance imaging (MRI) T2 mapping in quantitative evaluation of cartilage repair following matrix-associated autologous chondrocyte transplantation (MACT). Six patients (with 9 plug cartilages) following MACT underwent MRI on a 3.0 Tesla MR scan system at 3, 6 and 12 months after the surgery. The full-thickness and zonal areas (deep and superficial layers) T2 values were calculated for the repaired cartilage and control cartilage. The mean T2 values of the repaired cartilage after MACT were significantly higher than that of the control cartilages at 3 and 6 months (P<0.05), but not at 12 months (P=0.063). At 6 and 12 months, the T2 values of the superficial layers were significantly higher than those of the deep layers in the repaired cartilages (P<0.05). The zonal (deep and superficial layers) T2 values of the repaired cartilages decreased significantly over time at 6 and 12 months as compared to those at 3 months after the surgery (P<0.05). MRI T2 mapping can serve as an important modality for assessing the repair of the articular cartilage following MACT.

The Mechanism of High Ductility for Novel High-Carbon Quenching-Partitioning-Tempering Martensitic Steel

NASA Astrophysics Data System (ADS)

Qin, Shengwei; Liu, Yu; Hao, Qingguo; Wang, Ying; Chen, Nailu; Zuo, Xunwei; Rong, Yonghua

2015-09-01

In this article, a novel quenching-partitioning-tempering (Q-P-T) process was applied to treat Fe-0.6C-1.5Mn-1.5Si-0.6Cr-0.05Nb hot-rolled high-carbon steel and the microstructures including retained austenite fraction and the average dislocation densities in both martensite and retained austenite were characterized by X-ray diffraction, scanning electron microscopy, and transmission electron microscopy, respectively. The Q-P-T steel exhibits high strength (1950 MPa) and elongation (12.4 pct). Comparing with the steel treated by traditional quenching and tempering (Q&T) process, the mechanism of high ductility for high-carbon Q-P-T steel is revealed as follows. Much more retained austenite existing in Q-P-T steel than in Q&T one remarkably enhances the ductility by the following two effects: the dislocation absorption by retained austenite effect and the transformation-induced plasticity effect. Besides, lower dislocation density in martensite matrix produced by Q-P-T process plays an important role in the improvement of ductility. However, some thin plates of twin-type martensite embedded in dislocation-type martensite matrix in high-carbon Q-P-T steel affect the further improvement of ductility.

Measurement of the t-channel single-top-quark production cross section and of the $$\\mid V_{tb} \\mid$$ CKM matrix element in pp collisions at $$\\sqrt{s}$$= 8 TeV

DOE PAGES

Khachatryan, Vardan

2014-06-16

Our measurements are presented of the t-channel single-top-quark production cross section in proton-proton collisions at √s = 8 TeV. The results are based on a data sample corresponding to an integrated luminosity of 19.7 fb -1 recorded with the CMS detector at the LHC. The cross section is measured inclusively, as well as separately for top (t) and antitop (t¯), in final states with a muon or an electron. The measured inclusive t-channel cross section is σ t-ch. = 83.6 ± 2.3 (stat.) ± 7.4 (syst.) pb. The single t and t¯ cross sections are measured to be σ t-ch.(t)more » = 53.8 ± 1.5 (stat.) ± 4.4 (syst.) pb and σ t-ch. (t¯) = 27.6 ± 1.3 (stat.) ± 3.7 (syst.) pb, respectively. The measured ratio of cross sections is R t-ch. = σ t-ch.(t)/σ t-ch. (t¯) = 1.95 ± 0.10 (stat.) ± 0.19 (syst.), in agreement with the standard model prediction. Finally, the modulus of the Cabibbo-Kobayashi-Maskawa matrix element V tb is extracted and, in combination with a previous CMS result at √s = 7 TeV, a value |V tb| = 0.998 ± 0.038 (exp.) ± 0.016 (theo.) is obtained.« less

Mitochondrial tRNA cleavage by tRNA-targeting ribonuclease causes mitochondrial dysfunction observed in mitochondrial disease

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ogawa, Tetsuhiro, E-mail: atetsu@mail.ecc.u-tokyo.ac.jp; Shimizu, Ayano; Takahashi, Kazutoshi

2014-08-15

Highlights: • MTS-tagged ribonuclease was translocated successfully to the mitochondrial matrix. • MTS-tagged ribonuclease cleaved mt tRNA and reduced COX activity. • Easy and reproducible method of inducing mt tRNA dysfunction. - Abstract: Mitochondrial DNA (mtDNA) is a genome possessed by mitochondria. Since reactive oxygen species (ROS) are generated during aerobic respiration in mitochondria, mtDNA is commonly exposed to the risk of DNA damage. Mitochondrial disease is caused by mitochondrial dysfunction, and mutations or deletions on mitochondrial tRNA (mt tRNA) genes are often observed in mtDNA of patients with the disease. Hence, the correlation between mt tRNA activity and mitochondrialmore » dysfunction has been assessed. Then, cybrid cells, which are constructed by the fusion of an enucleated cell harboring altered mtDNA with a ρ{sup 0} cell, have long been used for the analysis due to difficulty in mtDNA manipulation. Here, we propose a new method that involves mt tRNA cleavage by a bacterial tRNA-specific ribonuclease. The ribonuclease tagged with a mitochondrial-targeting sequence (MTS) was successfully translocated to the mitochondrial matrix. Additionally, mt tRNA cleavage, which resulted in the decrease of cytochrome c oxidase (COX) activity, was observed.« less

Modular Study of the Type III Effector Repertoire in Pseudomonas syringae pv. tomato DC3000 Reveals a Matrix of Effector Interplay in Pathogenesis.

PubMed

Wei, Hai-Lei; Zhang, Wei; Collmer, Alan

2018-05-08

The bacterial pathogen Pseudomonas syringae pv. tomato DC3000 suppresses the two-tiered innate immune system of Nicotiana benthamiana and other plants by injecting a complex repertoire of type III secretion effector (T3E) proteins. Effectorless polymutant DC3000D36E was used with a modularized system for native delivery of the 29 DC3000 T3Es singly and in pairs. Assays of the performance of this T3E library in N. benthamiana leaves revealed a matrix of T3E interplay, with six T3Es eliciting death and eight others variously suppressing the death activity of the six. The T3E library was also interrogated for effects on DC3000D36E elicitation of a reactive oxygen species burst, for growth in planta, and for T3Es that reversed these effects. Pseudomonas fluorescens and Agrobacterium tumefaciens heterologous delivery systems yielded notably different sets of death-T3Es. The DC3000D36E T3E library system highlights the importance of 13 T3Es and their interplay in interactions with N. benthamiana. Copyright © 2018 The Author(s). Published by Elsevier Inc. All rights reserved.

The single-scattering properties of black carbon aggregates determined from the geometric-optics surface-wave approach and the T-matrix method

NASA Astrophysics Data System (ADS)

Takano, Y.; Liou, K. N.; Kahnert, M.; Yang, P.

2013-08-01

The single-scattering properties of eight black carbon (BC, soot) fractal aggregates, composed of primary spheres from 7 to 600, computed by the geometric-optics surface-wave (GOS) approach coupled with the Rayleigh-Gans-Debye (RGD) adjustment for size parameters smaller than approximately 2, are compared with those determined from the superposition T-matrix method. We show that under the condition of random orientation, the results from GOS/RGD are in general agreement with those from T-matrix in terms of the extinction and absorption cross-sections, the single-scattering co-albedo, and the asymmetry factor. When compared with the specific absorption (m2/g) measured in the laboratory, we illustrate that using the observed radii of primary spheres ranging from 3.3 to 25 nm, the theoretical values determined from GOS/RGD for primary sphere numbers of 100-600 are within the range of measured values. The GOS approach can be effectively applied to aggregates composed of a large number of primary spheres (e.g., >6000) and large size parameters (≫2) in terms of computational efforts.

T-matrix method in plasmonics: An overview

NASA Astrophysics Data System (ADS)

Khlebtsov, Nikolai G.

2013-07-01

Optical properties of isolated and coupled plasmonic nanoparticles (NPs) are of great interest for many applications in nanophotonics, nanobiotechnology, and nanomedicine owing to rapid progress in fabrication, characterization, and surface functionalization technologies. To simulate optical responses from plasmonic nanostructures, various electromagnetic analytical and numerical methods have been adapted, tested, and used during the past two decades. Currently, the most popular numerical techniques are those that do not suffer from geometrical and composition limitations, e.g., the discrete dipole approximation (DDA), the boundary (finite) element method (BEM, FEM), the finite difference time domain method (FDTDM), and others. However, the T-matrix method still has its own niche in plasmonic science because of its great numerical efficiency, especially for systems with randomly oriented particles and clusters. In this review, I consider the application of the T-matrix method to various plasmonic problems, including dipolar, multipolar, and anisotropic properties of metal NPs; sensing applications; surface enhanced Raman scattering; optics of 1D-3D nanoparticle assemblies; plasmonic particles and clusters near and on substrates; and manipulation of plasmonic NPs with laser tweezers.

Analytical prediction of moisture absorption/desorption in resin matrix composites exposed to aircraft environments

NASA Technical Reports Server (NTRS)

Unnam, J.; Tenney, D. R.

1977-01-01

The moisture absorption/desorption behavior of resin matrix composites was mathematically modeled by classical diffusion theory using an effective diffusion coefficient. Good agreement was found between calculated moisture content and published data for T300/5208 graphite fiber reinforced epoxy matrix composite. Weather Bureau data for Langley Air Force Base and Norfolk, Va., were used to calculate the amount of moisture a T300/5208 composite panel would contain if exposed outdoors. Results obtained by using average monthly weather data for several high aircraft usage locations around the world suggest that, except for desert areas, geographical locations should have only minimal effect on the moisture absorption level reached in composites. Solar radiation data together with cloud and wind information were included in the analysis to estimate an effective temperature of the composite panel during ground exposure.

VizieR Online Data Catalog: Outliers and similarity in APOGEE (Reis+, 2018)

NASA Astrophysics Data System (ADS)

Reis, I.; Poznanski, D.; Baron, D.; Zasowski, G.; Shahaf, S.

2017-11-01

t-SNE is a dimensionality reduction algorithm that is particularly well suited for the visualization of high-dimensional datasets. We use t-SNE to visualize our distance matrix. A-priori, these distances could define a space with almost as many dimensions as objects, i.e., tens of thousand of dimensions. Obviously, since many stars are quite similar, and their spectra are defined by a few physical parameters, the minimal spanning space might be smaller. By using t-SNE we can examine the structure of our sample projected into 2D. We use our distance matrix as input to the t-SNE algorithm and in return get a 2D map of the objects in our dataset. For each star in a sample of 183232 APOGEE stars, the APOGEE IDs of the 99 stars with most similar spectra (according to the method described in paper), ordered by similarity. (3 data files).

Drude weight of the spin-(1)/(2) XXZ chain: Density matrix renormalization group versus exact diagonalization

NASA Astrophysics Data System (ADS)

Karrasch, C.; Hauschild, J.; Langer, S.; Heidrich-Meisner, F.

2013-06-01

We revisit the problem of the spin Drude weight D of the integrable spin-1/2 XXZ chain using two complementary approaches, exact diagonalization (ED) and the time-dependent density-matrix renormalization group (tDMRG). We pursue two main goals. First, we present extensive results for the temperature dependence of D. By exploiting time translation invariance within tDMRG, one can extract D for significantly lower temperatures than in previous tDMRG studies. Second, we discuss the numerical quality of the tDMRG data and elaborate on details of the finite-size scaling of the ED results, comparing calculations carried out in the canonical and grand-canonical ensembles. Furthermore, we analyze the behavior of the Drude weight as the point with SU(2)-symmetric exchange is approached and discuss the relative contribution of the Drude weight to the sum rule as a function of temperature.

Optimum modulation and demodulation matrices for solar polarimetry.

PubMed

del Toro Iniesta, J C; Collados, M

2000-04-01

Both temporal and/or spatial modulation are mandatory in current solar polarimetry [Appl. Opt. 24, 3893 (1985); 26, 3838 (1987)]. The modulating and demodulating processes are mathematically described by matrices O and D, respectively, on whose structure the accuracy of Stokes parameter measurements depend. We demonstrate, based on the definition of polarimetric efficiency [Instituto de Astrofísica de Canarias Internal Report (1994); ASP Conf. Ser. 184, 3 (1999)], that the maximum efficiencies of an ideal polarimeter are unity for Stokes I and for (Q(2) + U(2) + V(2))(1/2) and that this occurs if and only if O(T)O is diagonal; given a general (possibly nonideal) modulation matrix O, the optimum demodulation matrix turns out to be D = (O(T)O)(-1)O(T); and the maximum efficiencies in the nonideal case are given by the rms value of the column elements of matrix O and are reached by modulation matrices such that O(T)O is diagonal. From these analytical results we distill two recipes useful in the practical design of polarimeters. Their usefulness is illustrated by discussing cases of currently available solar polarimeters. Although specifically devoted to solar polarimetry, the results here may be applied in practically all other branches of science for which polarimetric measurements are needed.

Asymptotic behavior of Nambu-Bethe-Salpeter wave functions for multiparticles in quantum field theories

NASA Astrophysics Data System (ADS)

Aoki, Sinya; Ishii, Noriyoshi; Doi, Takumi; Ikeda, Yoichi; Inoue, Takashi

2013-07-01

We derive asymptotic behaviors of the Nambu-Bethe-Salpeter (NBS) wave function at large space separations for systems with more than two particles in quantum field theories. To deal with n particles in the center-of-mass frame coherently, we introduce the Jacobi coordinates of n particles and then combine their 3(n-1) coordinates into the one spherical coordinate in D=3(n-1) dimensions. We parametrize the on-shell T matrix for n scalar particles at low energy using the unitarity constraint of the S matrix. We then express asymptotic behaviors of the NBS wave function for n particles at low energy in terms of parameters of the T matrix and show that the NBS wave function carries information of the T matrix such as phase shifts and mixing angles of the n-particle system in its own asymptotic behavior, so that the NBS wave function can be considered as the scattering wave of n particles in quantum mechanics. This property is one of the essential ingredients of the HAL QCD scheme to define “potential” from the NBS wave function in quantum field theories such as QCD. Our results, together with an extension to systems with spin 1/2 particles, justify the HAL QCD’s definition of potentials for three or more nucleons (or baryons) in terms of the NBS wave functions.

Doubly differential cross sections for galactic heavy-ion fragmentation

NASA Technical Reports Server (NTRS)

Cucinotta, Francis A.; Norbury, John W.; Khandelwal, Govind S.; Townsend, Lawrence W.

1987-01-01

An abrasion-ablation T-matrix formulation is applied to the calculation of double differential-cross sections in projectile fragmentation of 2.1 GeV/nucleon O-16 on Be-9 and 86 MeV/nucleon C-12 on C-12 and Ag-108. An exponential parameterization of the ablation T-matrix is used and the total width of the intermediate states is taken as a parameter. Fitted values of the total width to experimental results are used to predict the lifetime of the ablation stage and indicate a decay time on the order of 10 to the -19th power sec.

U.S. EPA, Pesticide Product Label, DUPONT MATRIX HERBICIDE, 06/26/2007

EPA Pesticide Factsheets

2011-04-14

... Q\\Vn tOflla~~~§~9:ir~~ts~~~~ ilJl~~tra ... purse (Capsella bursa-pastoris) Wild Radish (Raphanus raphanistrum) ... t See Specific Weed Problems 9 ...

The interplay of dietary nutrient level and varying calcium to phosphorus ratios on efficacy of a bacterial phytase: 2. Ileal and total tract nutrient utilization.

PubMed

Olukosi, O A; Fru-Nji, F

2014-12-01

A 14-d broiler experiment was conducted to assess the effects of 2 dietary variables on efficacy of a bacterial 6-phytase from Citobacter braakii on nutrient and phytate P (PP) utilization. Diets were formulated with or without nutrient matrix values (matrix) for phytase as negative control (NC) or positive control (PC), respectively, and with 2 Ca:total P (tP) levels (2:1 or 2.5:1). The diets were supplemented with 0, 1,000, or 2,000 phytase units (FYT)/kg of diet, thus producing a 2 × 2 × 3 factorial arrangement. Excreta were collected on d 19 to 21 and ileal digesta on d 21. There was no 3-way interaction on digestibility of any nutrient. There was matrix × phytase (P < 0.01) interaction for Ca and DM digestibility and Ca:tP × phytase interaction (P < 0.05) for acid hydrolyzed fat and Ca and P digestibility. Prececal flow of Mn, Zn, and Na was greater (P < 0.05) in NC diets, whereas phytase increased (P < 0.05) prececal flow of Mg, Fe, Mn, and Zn but decreased (P < 0.05) prececal Na flow. Total tract PP disappearance and total tract Ca retention increased (P < 0.05) with phytase supplementation in diets with 2:1 Ca:tP, whereas there was no effect of phytase supplementation on PP disappearance or Ca retention in diets with 2.5:1 Ca:tP. Total P and Ca retention were reduced (P < 0.05) in PC and NC diets when Ca:tP increased to 2.5:1, but the depression was more pronounced in the NC diet. In addition, PP disappearance decreased (P < 0.05) with increasing Ca:tP in the PC diets, but there was no effect of widening Ca:tP on PP disappearance in NC diets. It was concluded from the current study that the effect of phytase supplementation on P utilization is reduced when diets contain adequate P as exemplified in the PC diets and that the negative impact of wide Ca:tP is more pronounced in diets with phytase matrix allowance as exemplified in the NC diets. ©2014 Poultry Science Association Inc.

The interplay of dietary nutrient specification and varying calcium to total phosphorus ratio on efficacy of a bacterial phytase: 1. Growth performance and tibia mineralization.

PubMed

Olukosi, O A; Fru-Nji, F

2014-12-01

A 14-d experiment was conducted to study the effects of 2 dietary variables on efficacy of a 6-phytase from Citrobacter braakii on broiler growth performance and tibia mineralization. Diets were formulated with or without nutrient matrix values for phytase as negative or positive control (NC or PC, respectively) and with 2 Ca:total P (tP; 2:1 or 2.5:1). The diets were supplemented with 0, 1,000, or 2,000 phytase units (FYT)/kg, thus producing a 2 × 2 × 3 factorial arrangement. Birds and feed were weighed on d 7 and 21, and tibia bones were collected from all the birds on d 21. The main effects of nutrient matrix, Ca:tP, and phytase supplementation were significant (P < 0.05) for all the growth performance responses (except for G:F for which there was no effect of matrix). The Ca:tP × phytase and matrix × phytase interactions were significant (P < 0.05) for weight gain. In the PC diets, phytase increased weight gain (P < 0.05) relative to the control only in diets with 2,000 FYT/kg, whereas in NC diets weight gain increased (P < 0.01) only from 0 to 1,000 FYT/kg levels. Broilers consuming diets with 2.5:1 Ca:tP had lower (P < 0.05) tibia ash, whereas phytase increased (P < 0.01) tibia ash, Ca, P, and Zn but decreased (P < 0.01) tibia K. Phytase supplementation of diets with 2:1 Ca:tP increased (P < 0.05) tibia P in birds receiving 1,000 FYT/kg relative to the control with no further increase at 2,000 FYT/kg, whereas each level of phytase supplementation increased (P < 0.05) tibia P in the diets with 2.5:1 Ca:tP. It was concluded that the best response to lower phytase supplementation (1,000 FYT/kg) was in NC diets with narrow Ca:tP, whereas the best response to higher level of phytase supplementation (2,000 FYT/kg) was achieved in diets in PC diets with wide Ca:tP. ©2014 Poultry Science Association Inc.

The phase transition of matrix recovery from Gaussian measurements matches the minimax MSE of matrix denoising.

PubMed

Donoho, David L; Gavish, Matan; Montanari, Andrea

2013-05-21

Let X(0) be an unknown M by N matrix. In matrix recovery, one takes n < MN linear measurements y(1),…,y(n) of X(0), where y(i) = Tr(A(T)iX(0)) and each A(i) is an M by N matrix. A popular approach for matrix recovery is nuclear norm minimization (NNM): solving the convex optimization problem min ||X||*subject to y(i) =Tr(A(T)(i)X) for all 1 ≤ i ≤ n, where || · ||* denotes the nuclear norm, namely, the sum of singular values. Empirical work reveals a phase transition curve, stated in terms of the undersampling fraction δ(n,M,N) = n/(MN), rank fraction ρ=rank(X0)/min {M,N}, and aspect ratio β=M/N. Specifically when the measurement matrices Ai have independent standard Gaussian random entries, a curve δ*(ρ) = δ*(ρ;β) exists such that, if δ > δ*(ρ), NNM typically succeeds for large M,N, whereas if δ < δ*(ρ), it typically fails. An apparently quite different problem is matrix denoising in Gaussian noise, in which an unknown M by N matrix X(0) is to be estimated based on direct noisy measurements Y =X(0) + Z, where the matrix Z has independent and identically distributed Gaussian entries. A popular matrix denoising scheme solves the unconstrained optimization problem min|| Y-X||(2)(F)/2+λ||X||*. When optimally tuned, this scheme achieves the asymptotic minimax mean-squared error M(ρ;β) = lim(M,N → ∞)inf(λ)sup(rank(X) ≤ ρ · M)MSE(X,X(λ)), where M/N → . We report extensive experiments showing that the phase transition δ*(ρ) in the first problem, matrix recovery from Gaussian measurements, coincides with the minimax risk curve M(ρ)=M(ρ;β) in the second problem, matrix denoising in Gaussian noise: δ*(ρ)=M(ρ), for any rank fraction 0 < ρ < 1 (at each common aspect ratio β). Our experiments considered matrices belonging to two constraint classes: real M by N matrices, of various ranks and aspect ratios, and real symmetric positive-semidefinite N by N matrices, of various ranks.

Nonlinear Dynamics and Control of Wings and Panels.

DTIC Science & Technology

1996-12-04

y, z, t) = fluid velocity potential d31 = piezoelectric constant T&(x, y) = modal expansion functions H,•(t) = aerodynamic influence function h...thickness Subscripts l,(t) = aerodynamic influence function a = aerodynamic i = output current vector m, n = modal indices K = stiffness matrix p...acting on a piston in a tube: As an example, suppose the values of the influence function H,,.(iT) are used to solve for the filter coefficients in Eq

Matrix Completion Optimization for Localization in Wireless Sensor Networks for Intelligent IoT

PubMed Central

Nguyen, Thu L. N.; Shin, Yoan

2016-01-01

Localization in wireless sensor networks (WSNs) is one of the primary functions of the intelligent Internet of Things (IoT) that offers automatically discoverable services, while the localization accuracy is a key issue to evaluate the quality of those services. In this paper, we develop a framework to solve the Euclidean distance matrix completion problem, which is an important technical problem for distance-based localization in WSNs. The sensor network localization problem is described as a low-rank dimensional Euclidean distance completion problem with known nodes. The task is to find the sensor locations through recovery of missing entries of a squared distance matrix when the dimension of the data is small compared to the number of data points. We solve a relaxation optimization problem using a modification of Newton’s method, where the cost function depends on the squared distance matrix. The solution obtained in our scheme achieves a lower complexity and can perform better if we use it as an initial guess for an interactive local search of other higher precision localization scheme. Simulation results show the effectiveness of our approach. PMID:27213378

Highly symmetric D-brane-anti-D-brane effective actions

NASA Astrophysics Data System (ADS)

Hatefi, Ehsan

2017-09-01

The entire S-matrix elements of four, five and six point functions of D-brane-anti D-brane system are explored. To deal with symmetries of string amplitudes as well as their all order α ' corrections we first address a four point function of one closed string Ramond-Ramond (RR) and two real tachyons on the world volume of brane-anti brane system. We then focus on symmetries of string theory as well as universal tachyon expansion to achieve both string and effective field theory of an RR and three tachyons where the complete algebraic analysis for the whole S-matrix < {V}_{C^{-1}}{V}_{T^{-1}}{V}_{T^0}{V}_{T^0}> was also revealed. Lastly, we employ all the conformal field theory techniques to < {V}_{C^{-1}}{V}_{T^{-1}}{V}_{T^0}{V}_{T^0}{V}_{T^0}> , working out with symmetries of theory and find out the expansion for the amplitude to be able to precisely discover all order singularity structures of D-brane-anti-D-brane effective actions of string theory. Various remarks about the so called generalized Veneziano amplitude and new string couplings are elaborated as well.

Role of Nuclear Matrix in Estrogen Regulated Gene Expression in Human Breast Cancer Cells

DTIC Science & Technology

1998-08-01

reticular pattern evenly distributed throughout the nucleus, excluding the nucleolus (Figure 4A). This is not so for T47D cells where a composite pattern...acetylation is required to maintain the unfolded nucleosome structure associated with transcribing DNA. Journal of Biological Chemistry 273:14516...nuclear matrix include ER, YY1, AML-1, Spl, Oct1, mutant p53, and Rb [25,28,31,34-40]. Appendix A, part 4 reviews alterations in nuclear matrix composition

Modeling the Role of Bulk and Surface Characteristics of Carbon Fiber on Thermal Conductance across the Carbon Fiber/Matrix Interface (Postprint)

DTIC Science & Technology

2015-11-09

Osguthorpe, D. J.; Wolff, J.; Genest, M.; Hagler, A. T. Structure and Energetics of Ligand Binding to Proteins: Escherichia Coli Dihydrofolate...available at DOI: 10.1021/acsami.5b08591 14. ABSTRACT (Maximum 200 words) The rapid heating of carbon-fiber-reinforced polymer matrix composites leads ...polymer matrix composites leads to complex thermophysical interactions which not only are dependent on the thermal properties of the constituents and

Quantitative T2-Mapping and T2⁎-Mapping Evaluation of Changes in Cartilage Matrix after Acute Anterior Cruciate Ligament Rupture and the Correlation between the Results of Both Methods.

PubMed

Tao, Hongyue; Qiao, Yang; Hu, Yiwen; Xie, Yuxue; Lu, Rong; Yan, Xu; Chen, Shuang

2018-01-01

To quantitatively assess changes in cartilage matrix after acute anterior cruciate ligament (ACL) rupture using T2- and T2 ⁎ -mapping and analyze the correlation between the results of both methods. Twenty-three patients and 23 healthy controls were enrolled and underwent quantitative MRI examination. The knee cartilage was segmented into six compartments, including lateral femur (LF), lateral tibia (LT), medial femur (MF), medial tibia (MT), trochlea (Tr), and patella (Pa). T2 and T2 ⁎ values were measured in full-thickness as well as superficial and deep layers of each cartilage compartment. Differences of T2 and T2 ⁎ values between patients and controls were compared using unpaired Student's t -test, and the correlation between their reciprocals was analyzed using Pearson's correlation coefficient. ACL-ruptured patients showed higher T2 and T2 ⁎ values in full-thickness and superficial layers of medial and lateral tibiofemoral joint. Meanwhile, patients exhibited higher T2 ⁎ values in deep layers of lateral tibiofemoral joint. The elevated percentages of T2 and T2 ⁎ value in superficial LT were most significant (20.738%, 17.525%). The reciprocal of T2 ⁎ value was correlated with that of T2 value ( r = 0.886, P < 0.001). The early degeneration could occur in various knee cartilage compartments after acute ACL rupture, especially in the superficial layer of LT. T2 ⁎ -mapping might be more sensitive in detecting deep layer of cartilage than T2-mapping.

Information loss in effective field theory: Entanglement and thermal entropies

NASA Astrophysics Data System (ADS)

Boyanovsky, Daniel

2018-03-01

Integrating out high energy degrees of freedom to yield a low energy effective field theory leads to a loss of information with a concomitant increase in entropy. We obtain the effective field theory of a light scalar field interacting with heavy fields after tracing out the heavy degrees of freedom from the time evolved density matrix. The initial density matrix describes the light field in its ground state and the heavy fields in equilibrium at a common temperature T . For T =0 , we obtain the reduced density matrix in a perturbative expansion; it reveals an emergent mixed state as a consequence of the entanglement between light and heavy fields. We obtain the effective action that determines the time evolution of the reduced density matrix for the light field in a nonperturbative Dyson resummation of one-loop correlations of the heavy fields. The Von-Neumann entanglement entropy associated with the reduced density matrix is obtained for the nonresonant and resonant cases in the asymptotic long time limit. In the nonresonant case the reduced density matrix displays an incipient thermalization albeit with a wave-vector, time and coupling dependent effective temperature as a consequence of memory of initial conditions. The entanglement entropy is time independent and is the thermal entropy for this effective, nonequilibrium temperature. In the resonant case the light field fully thermalizes with the heavy fields, the reduced density matrix loses memory of the initial conditions and the entanglement entropy becomes the thermal entropy of the light field. We discuss the relation between the entanglement entropy ultraviolet divergences and renormalization.

Effect of fiber reinforcements on thermo-oxidative stability and mechanical properties of polymer matrix composites

NASA Technical Reports Server (NTRS)

Bowles, Kenneth J.

1991-01-01

A number of studies have investigated the thermo-oxidative behavior of polymer matrix composites. Two significant observations have been made from these research efforts: (1) fiber reinforcement has a significant effect on composite thermal stability; and (2) geometric effects must be considered when evaluating thermal aging data. A compilation of some results from these studies is presented, and this information shows the influence of the reinforcement fibers on the oxidative degradation of various polymer matrix composites. The polyimide PMR-15 was the matrix material that was used in these studies. The control composite material was reinforced with Celion 6000 graphite fiber. T-40R graphite fibers, along with some very stable ceramic fibers were selected as reinforcing fibers because of their high thermal stability. The ceramic fibers were Nicalon (silicon carbide) and Nextel 312 (alumina-silica-boron oxide). The mechanical properties of the two graphite fiber composites were significantly different, probably owing to variations in interfacial bonding between the fibers and the polyimide matrix. The Celion 6000/PMR-15 bond is very tight but the T-40/PMR-15 bond is less tight. Three oxidation mechanisms were observed: (1) the preferential oxidation of the Celion 6000 fiber ends at cut surfaces, leaving a surface of matrix material with holes where the fiber ends were originally situated; (2) preferential oxidation of the composite matrix; and (3) interfacial degradation by oxidation. The latter two mechanisms were also observed on fiber end cut surfaces. The fiber and interface attacks appeared to initiate interfiber cracking along these surfaces.

Divvy Economies Based On (An Abstract) Temperature

NASA Astrophysics Data System (ADS)

Collins, Dennis G.

2004-04-01

The Leontief Input-Output economic system can provide a model for a one-parameter family of economic systems based on an abstract temperature T. In particular, given a normalized input-output matrix R and taking R= R(1), a family of economic systems R(1/T)=R(α) is developed that represents heating (T>1) and cooling (T<1) of the economy relative to T=1. .The economy for a given value of T represents the solution of a constrained maximum entropy problem.

Tetragonal zirconia quantum dots in silica matrix prepared by a modified sol-gel protocol

NASA Astrophysics Data System (ADS)

Verma, Surbhi; Rani, Saruchi; Kumar, Sushil

2018-05-01

Tetragonal zirconia quantum dots (t-ZrO2 QDs) in silica matrix with different compositions ( x)ZrO2-(100 - x)SiO2 were fabricated by a modified sol-gel protocol. Acetylacetone was added as a chelating agent to zirconium propoxide to avoid precipitation. The powders as well as thin films were given thermal treatment at 650, 875 and 1100 °C for 4 h. The silica matrix remained amorphous after thermal treatment and acted as an inert support for zirconia quantum dots. The tetragonal zirconia embedded in silica matrix transformed into monoclinic form due to thermal treatment ≥ 1100 °C. The stability of tetragonal phase of zirconia is found to enhance with increase in silica content. A homogenous dispersion of t-ZrO2 QDs in silica matrix was indicated by the mapping of Zr, Si and O elements obtained from scanning electron microscope with energy dispersive X-ray analyser. The transmission electron images confirmed the formation of tetragonal zirconia quantum dots embedded in silica. The optical band gap of zirconia QDs (3.65-5.58 eV) was found to increase with increase in zirconia content in silica. The red shift of PL emission has been exhibited with increase in zirconia content in silica.

Study of drug release and tablet characteristics of silicone adhesive matrix tablets.

PubMed

Tolia, Gaurav; Li, S Kevin

2012-11-01

Matrix tablets of a model drug acetaminophen (APAP) were prepared using a highly compressible low glass transition temperature (T(g)) polymer silicone pressure sensitive adhesive (PSA) at various binary mixtures of silicone PSA/APAP ratios. Matrix tablets of a rigid high T(g) matrix forming polymer ethyl cellulose (EC) were the reference for comparison. Drug release study was carried out using USP Apparatus 1 (basket), and the relationship between the release kinetic parameters of APAP and polymer/APAP ratio was determined to estimate the excipient percolation threshold. The critical points attributed to both silicone PSA and EC tablet percolation thresholds were found to be between 2.5% and 5% w/w. For silicone PSA tablets, satisfactory mechanical properties were obtained above the polymer percolation threshold; no cracking or chipping of the tablet was observed above this threshold. Rigid EC APAP tablets showed low tensile strength and high friability. These results suggest that silicone PSA could eliminate issues related to drug compressibility in the formulation of directly compressed oral controlled release tablets of poorly compressible drug powder such as APAP. No routinely used excipients such as binders, granulating agents, glidants, or lubricants were required for making an acceptable tablet matrix of APAP using silicone PSA. Copyright © 2012 Elsevier B.V. All rights reserved.

Matrix Metalloproteinases 2 and 9 Are Differentially Expressed in Patients with Indeterminate and Cardiac Clinical Forms of Chagas Disease

PubMed Central

Fares, Rafaelle Christine Gomes; Gomes, Juliana de Assis Silva; Garzoni, Luciana Ribeiro; Waghabi, Mariana Caldas; Saraiva, Roberto Magalhães; Medeiros, Nayara Ingrid; Oliveira-Prado, Roberta; Sangenis, Luiz Henrique Conde; Chambela, Mayara da Costa; de Araújo, Fernanda Fortes; Teixeira-Carvalho, Andréa; Damásio, Marcos Paulo; Valente, Vanessa Azevedo; Ferreira, Karine Silvestre; Sousa, Giovane Rodrigo; Rocha, Manoel Otávio da Costa

2013-01-01

Dilated chronic cardiomyopathy (DCC) from Chagas disease is associated with myocardial remodeling and interstitial fibrosis, resulting in extracellular matrix (ECM) changes. In this study, we characterized for the first time the serum matrix metalloproteinase 2 (MMP-2) and MMP-9 levels, as well as their main cell sources in peripheral blood mononuclear cells from patients presenting with the indeterminate (IND) or cardiac (CARD) clinical form of Chagas disease. Our results showed that serum levels of MMP-9 are associated with the severity of Chagas disease. The analysis of MMP production by T lymphocytes showed that CD8+ T cells are the main mononuclear leukocyte source of both MMP-2 and MMP-9 molecules. Using a new 3-dimensional model of fibrosis, we observed that sera from patients with Chagas disease induced an increase in the extracellular matrix components in cardiac spheroids. Furthermore, MMP-2 and MMP-9 showed different correlations with matrix proteins and inflammatory cytokines in patients with Chagas disease. Our results suggest that MMP-2 and MMP-9 show distinct activities in Chagas disease pathogenesis. While MMP-9 seems to be involved in the inflammation and cardiac remodeling of Chagas disease, MMP-2 does not correlate with inflammatory molecules. PMID:23856618

Novel hydrophobic interaction chromatography matrix for specific isolation and simple elution of immunoglobulins (A, G, and M) from porcine serum.

PubMed

Ramos-Clamont, Gabriela; del Carmen Candia-Plata, Maria; Zamudio, Roberto Guzman; Vazquez-Moreno, Luz

2006-07-28

A new, highly acetylated agarose matrix (HA-Sepharose) was synthesized and used as a hydrophobic interaction chromatography (HIC) medium to specifically isolate immunoglobulins (Igs) from porcine serum. Recovery of Igs was in a single step and under mild conditions. HA-Sepharose adsorption was studied in terms of salt, gel acetylation time, flow rate, and protein concentration on the loading buffer. At 0.5 M Na2SO4, control with unmodified Sepharose retained a small fraction (0.70 mg/mL of matrix) of serum albumin. On the contrary HA-Sepharose retained primary Igs (IgA, IgG, and 53% of IgM) as revealed by sodium dodecyl sulphate 10% polyacrylamide gel electrophoresis (SDS-PAGE), quantitative radial immunodiffusion and immunodetection. At a flow rate of 1 mL/min, the HA-Sepharose column capacity (3.9 mg/mL of matrix) was similar to the reported capacity for the commercial thiophilic T-gel. However, HA-Sepharose showed higher recovery of IgA and IgM than the T-gel in the same salt conditions, clearly an advantage in terms of immunoglobulin recovery strategies. Acetylation changed the matrix adsorption from albumin to immunoglobulins; thus, the highly acetylated gel rendered recoveries of Igs from unprocessed porcine serum practically free of albumin.

SU-F-R-32: Evaluation of MRI Acquisition Parameter Variations On Texture Feature Extraction Using ACR Phantom

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xie, Y; Wang, J; Wang, C

Purpose: To investigate the sensitivity of classic texture features to variations of MRI acquisition parameters. Methods: This study was performed on American College of Radiology (ACR) MRI Accreditation Program Phantom. MR imaging was acquired on a GE 750 3T scanner with XRM explain gradient, employing a T1-weighted images (TR/TE=500/20ms) with the following parameters as the reference standard: number of signal average (NEX) = 1, matrix size = 256×256, flip angle = 90°, slice thickness = 5mm. The effect of the acquisition parameters on texture features with and without non-uniformity correction were investigated respectively, while all the other parameters were keptmore » as reference standard. Protocol parameters were set as follows: (a). NEX = 0.5, 2 and 4; (b).Phase encoding steps = 128, 160 and 192; (c). Matrix size = 128×128, 192×192 and 512×512. 32 classic texture features were generated using the classic gray level run length matrix (GLRLM) and gray level co-occurrence matrix (GLCOM) from each image data set. Normalized range ((maximum-minimum)/mean) was calculated to determine variation among the scans with different protocol parameters. Results: For different NEX, 31 out of 32 texture features’ range are within 10%. For different phase encoding steps, 31 out of 32 texture features’ range are within 10%. For different acquisition matrix size without non-uniformity correction, 14 out of 32 texture features’ range are within 10%; for different acquisition matrix size with non-uniformity correction, 16 out of 32 texture features’ range are within 10%. Conclusion: Initial results indicated that those texture features that range within 10% are less sensitive to variations in T1-weighted MRI acquisition parameters. This might suggest that certain texture features might be more reliable to be used as potential biomarkers in MR quantitative image analysis.« less

Dynamics of asymmetric binary glass formers. I. A dielectric and nuclear magnetic resonance spectroscopy study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kahlau, R.; Bock, D.; Schmidtke, B.

2014-01-28

Dielectric spectroscopy as well as {sup 2}H and {sup 31}P nuclear magnetic resonance spectroscopy (NMR) are applied to probe the component dynamics of the binary glass former tripropyl phosphate (TPP)/polystyrene (PS/PS-d{sub 3}) in the full concentration (c{sub TPP}) range. In addition, depolarized light scattering and differential scanning calorimetry experiments are performed. Two glass transition temperatures are found: T{sub g1}(c{sub TPP}) reflects PS dynamics and shows a monotonic plasticizer effect, while the lower T{sub g2}(c{sub TPP}) exhibits a maximum and is attributed to (faster) TPP dynamics, occurring in a slowly moving or immobilized PS matrix. Dielectric spectroscopy probing solely TPP identifiesmore » two different time scales, which are attributed to two sub-ensembles. One of them, again, shows fast TPP dynamics (α{sub 2}-process), the other (α{sub 1}-process) displays time constants identical with those of the slow PS matrix. Upon heating the α{sub 1}-fraction of TPP decreases until above some temperature T{sub c} only a single α{sub 2}-population exists. Inversely, below T{sub c} a fraction of the TPP molecules is trapped by the PS matrix. At low c{sub TPP} the α{sub 2}-relaxation does not follow frequency-temperature superposition (FTS), instead it is governed by a temperature independent distribution of activation energies leading to correlation times which follow Arrhenius laws, i.e., the α{sub 2}-relaxation resembles a secondary process. Yet, {sup 31}P NMR demonstrates that it involves isotropic reorientations of TPP molecules within a slowly moving or rigid matrix of PS. At high c{sub TPP} the super-Arrhenius temperature dependence of τ{sub 2}(T), as well as FTS are recovered, known as typical of the glass transition in neat systems.« less

On the computation and updating of the modified Cholesky decomposition of a covariance matrix

NASA Technical Reports Server (NTRS)

Vanrooy, D. L.

1976-01-01

Methods for obtaining and updating the modified Cholesky decomposition (MCD) for the particular case of a covariance matrix when one is given only the original data are described. These methods are the standard method of forming the covariance matrix K then solving for the MCD, L and D (where K=LDLT); a method based on Householder reflections; and lastly, a method employing the composite-t algorithm. For many cases in the analysis of remotely sensed data, the composite-t method is the superior method despite the fact that it is the slowest one, since (1) the relative amount of time computing MCD's is often quite small, (2) the stability properties of it are the best of the three, and (3) it affords an efficient and numerically stable procedure for updating the MCD. The properties of these methods are discussed and FORTRAN programs implementing these algorithms are listed.

Improvement of Mishchenko's T-matrix code for absorbing particles.

PubMed

Moroz, Alexander

2005-06-10

The use of Gaussian elimination with backsubstitution for matrix inversion in scattering theories is discussed. Within the framework of the T-matrix method (the state-of-the-art code by Mishchenko is freely available at http://www.giss.nasa.gov/-crmim), it is shown that the domain of applicability of Mishchenko's FORTRAN 77 (F77) code can be substantially expanded in the direction of strongly absorbing particles where the current code fails to converge. Such an extension is especially important if the code is to be used in nanoplasmonic or nanophotonic applications involving metallic particles. At the same time, convergence can also be achieved for large nonabsorbing particles, in which case the non-Numerical Algorithms Group option of Mishchenko's code diverges. Computer F77 implementation of Mishchenko's code supplemented with Gaussian elimination with backsubstitution is freely available at http://www.wave-scattering.com.

Interpretation of light scattering and turbidity measurements in aggregated systems: effect of intra-cluster multiple-light scattering.

PubMed

Soos, Miroslav; Lattuada, Marco; Sefcik, Jan

2009-11-12

In this work we studied the effect of intracluster multiple-light scattering on the scattering properties of a population of fractal aggregates. To do so, experimental data of diffusion-limited aggregation for three polystyrene latexes with similar surface properties but different primary particle diameters (equal to 118, 420, and 810 nm) were obtained by static light scattering and by means of a spectrophotometer. In parallel, a population balance equation (PBE) model, which takes into account the effect of intracluster multiple-light scattering by solving the T-matrix and the mean-field version of T-matrix, was formulated and validated against time evolution of the root mean radius of gyration, , of the zero angle intensity of scattered light, I(0), and of the turbidity, tau. It was found that the mean-field version of the T-matrix theory is able to correctly predict the time evolution of all measured light scattering quantities for all sizes of primary particles without any adjustable parameter. The structure of the aggregates, characterized by fractal dimension, d(f), was independent of the primary particle size and equal to 1.7, which is in agreement with values found in literature. Since the mean-field version of the T-matrix theory used is rather complicated and requires advanced knowledge of cluster structure (i.e., the particle-particle correlation function), a simplified version of the light scattering model was proposed and tested. It was found that within the range of operating conditions investigated, the simplified version of the light scattering model was able to describe with reasonable accuracy the time evolution of all measured light scattering quantities of the cluster mass distribution (CMD) for all three sizes of primary particles and two values of the laser wavelength.

A comparison of companion matrix methods to find roots of a trigonometric polynomial

NASA Astrophysics Data System (ADS)

Boyd, John P.

2013-08-01

A trigonometric polynomial is a truncated Fourier series of the form fN(t)≡∑j=0Naj cos(jt)+∑j=1N bj sin(jt). It has been previously shown by the author that zeros of such a polynomial can be computed as the eigenvalues of a companion matrix with elements which are complex valued combinations of the Fourier coefficients, the "CCM" method. However, previous work provided no examples, so one goal of this new work is to experimentally test the CCM method. A second goal is introduce a new alternative, the elimination/Chebyshev algorithm, and experimentally compare it with the CCM scheme. The elimination/Chebyshev matrix (ECM) algorithm yields a companion matrix with real-valued elements, albeit at the price of usefulness only for real roots. The new elimination scheme first converts the trigonometric rootfinding problem to a pair of polynomial equations in the variables (c,s) where c≡cos(t) and s≡sin(t). The elimination method next reduces the system to a single univariate polynomial P(c). We show that this same polynomial is the resultant of the system and is also a generator of the Groebner basis with lexicographic ordering for the system. Both methods give very high numerical accuracy for real-valued roots, typically at least 11 decimal places in Matlab/IEEE 754 16 digit floating point arithmetic. The CCM algorithm is typically one or two decimal places more accurate, though these differences disappear if the roots are "Newton-polished" by a single Newton's iteration. The complex-valued matrix is accurate for complex-valued roots, too, though accuracy decreases with the magnitude of the imaginary part of the root. The cost of both methods scales as O(N3) floating point operations. In spite of intimate connections of the elimination/Chebyshev scheme to two well-established technologies for solving systems of equations, resultants and Groebner bases, and the advantages of using only real-valued arithmetic to obtain a companion matrix with real-valued elements, the ECM algorithm is noticeably inferior to the complex-valued companion matrix in simplicity, ease of programming, and accuracy.

The spatial QRS-T angle in the Frank vectorcardiogram: accuracy of estimates derived from the 12-lead electrocardiogram.

PubMed

Schreurs, Charlotte A; Algra, Annemijn M; Man, Sum-Che; Cannegieter, Suzanne C; van der Wall, Ernst E; Schalij, Martin J; Kors, Jan A; Swenne, Cees A

2010-01-01

The spatial QRS-T angle (SA), a predictor of sudden cardiac death, is a vectorcardiographic variable. Gold standard vertorcardiograms (VCGs) are recorded by using the Frank electrode positions. However, with the commonly available 12-lead ECG, VCGs must be synthesized by matrix multiplication (inverse Dower matrix/Kors matrix). Alternatively, Rautaharju proposed a method to calculate SA directly from the 12-lead ECG. Neither spatial angles computed by using the inverse Dower matrix (SA-D) nor by using the Kors matrix (SA-K) or by using Rautaharju's method (SA-R) have been validated with regard to the spatial angles as directly measured in the Frank VCG (SA-F). Our present study aimed to perform this essential validation. We analyzed SAs in 1220 simultaneously recorded 12-lead ECGs and VCGs, in all data, in SA-F-based tertiles, and after stratification according to pathology or sex. Linear regression of SA-K, SA-D, and SA-R on SA-F yielded offsets of 0.01 degree, 20.3 degrees, and 28.3 degrees and slopes of 0.96, 0.86, and 0.79, respectively. The bias of SA-K with respect to SA-F (mean +/- SD, -3.2 degrees +/- 13.9 degrees) was significantly (P < .001) smaller than the bias of both SA-D and SA-R with respect to SA-F (8.0 degrees +/- 18.6 degrees and 9.8 degrees +/- 24.6 degrees, respectively); tertile analysis showed a much more homogeneous behavior of the bias in SA-K than of both the bias in SA-D and in SA-R. In pathologic ECGs, there was no significant bias in SA-K; bias in men and women did not differ. SA-K resembled SA-F best. In general, when there is no specific reason either to synthesize VCGs with the inverse Dower matrix or to calculate the spatial QRS-T angle with Rautaharju's method, it seems prudent to use the Kors matrix. Copyright 2010 Elsevier Inc. All rights reserved.

Nonlinear behavior of matrix-inclusion composites under high confining pressure: application to concrete and mortar

NASA Astrophysics Data System (ADS)

Le, Tuan Hung; Dormieux, Luc; Jeannin, Laurent; Burlion, Nicolas; Barthélémy, Jean-François

2008-08-01

This paper is devoted to a micromechanics-based simulation of the response of concrete to hydrostatic and oedometric compressions. Concrete is described as a composite made up of a cement matrix in which rigid inclusions are embedded. The focus is put on the role of the interface between matrix and inclusion which represent the interfacial transition zone (ITZ). A plastic behavior is considered for both the matrix and the interfaces. The effective response of the composite is derived from the modified secant method adapted to the situation of imperfect interfaces. To cite this article: T.H. Le et al., C. R. Mecanique 336 (2008).

Annual Review of Research Under the Joint Services Electronics Program.

DTIC Science & Technology

1983-12-01

Total Number of Professionals: PI 2 RA 2 (1/2 time ) 6. Sunmmary: Our research into the theory of nonlinear control systems and appli- * cations to...known that all linear time -invariant controllable systems can be transformed to Brunovsky canonical form by a transformation consist- ing only of...estimating the impulse response ( = transfer matrix) of a discrete- time linear system x(t+l) = Fx(t) + Gu(t) y(t) = Hx(t) from a finite set of finite

Improved Assessment Strategies for Vapor Intrusion Passive Samplers and Building Pressure Control

DTIC Science & Technology

2013-09-01

pressure control. Matrix Analyte Method Container Holding Time (Days) Vapor Radon McHugh , Hammond, Nickels , and Hartman, 2008 Tedlar ® bag 14...2: Diffusive Sampling,” ISO 16017-2:2003. McHugh T. E., D. E. Hammond, T. Nickels , and B. Hartman. 2008. “Use of Radon Measurements for Evaluation...Control I. D. Rivera-Duarte D. B. Chadwick SSC Pacific T. McAlary H. Groenevelt T. Creamer D. Bertrand Geosyntec Consultants, Inc. T. McHugh

Microstructure, elastic, and inelastic properties of biomorphic carbons carbonized using a Fe-containing catalyst

NASA Astrophysics Data System (ADS)

Orlova, T. S.; Kardashev, B. K.; Smirnov, B. I.; Gutierrez-Pardo, A.; Ramirez-Rico, J.

2016-12-01

The microstructure and amplitude dependences of the Young's modulus E and internal friction (logarithmic decrement δ), and microplastic properties of biocarbon matrices BE-C(Fe) obtained by beech tree carbonization at temperatures T carb = 850-1600°C in the presence of an iron-containing catalyst are studied. By X-ray diffraction analysis and transmission electron microscopy, it is shown that the use of Fe-catalyst during carbonization with T carb ≥ 1000°C leads to the appearance of a bulk graphite phase in the form of nanoscale bulk graphite inclusions in a quasi-amorphous matrix, whose volume fraction and size increase with T carb. The correlation of the obtained dependences E( T carb) and δ( T carb) with microstructure evolution with increasing T carb is revealed. It is found that E is mainly defined by a crystalline phase fraction in the amorphous matrix, i.e., a nanocrystalline phase at T carb < 1150°C and a bulk graphite phase at T carb > 1300°C. Maximum values E = 10-12 GPa are achieved for samples with T carb ≈ 1150 and 1600°C. It is shown that the microplasticity manifest itself only in biocarbons with T carb ≥ 1300°C (upon reaching a significant volume of the graphite phase); in this case, the conditional microyield stress decreases with increasing total volume of introduced mesoporosity (free surface area).

An algorithm for the basis of the finite Fourier transform

NASA Technical Reports Server (NTRS)

Santhanam, Thalanayar S.

1995-01-01

The Finite Fourier Transformation matrix (F.F.T.) plays a central role in the formulation of quantum mechanics in a finite dimensional space studied by the author over the past couple of decades. An outstanding problem which still remains open is to find a complete basis for F.F.T. In this paper we suggest a simple algorithm to find the eigenvectors of F.T.T.

Binary blend of glyceryl monooleate and glyceryl monostearate for magnetically induced thermo-responsive local drug delivery system.

PubMed

Mengesha, Abebe E; Wydra, Robert J; Hilt, J Zach; Bummer, Paul M

2013-12-01

To develop a novel monoglycerides-based thermal-sensitive drug delivery system, specifically for local intracavitary chemotherapy. Lipid matrices containing mixtures of glyceryl monooleate (GMO) and glyceryl monostearate (GMS) were evaluated for their potential application as magnetically induced thermo-responsive local drug delivery systems using a poorly water-soluble model drug, nifedipine (NF). Oleic acid-modified iron oxide (OA-Fe3O4) nanoparticles were embedded into the GMO-GMS matrix for remote activation of the drug release using an alternating magnetic field (AMF). The crystallization behavior of binary blends of GMO and GMS as characterized by DSC did show temperature dependent phase transition. GMO-GMS (75:25 wt%) blend showed a melting (T m ) and crystallization (T c ) points at 42°C and 37°C, respectively indicating the potential of the matrix to act as an 'on-demand' drug release. The matrix released only 35% of the loaded drug slowly in 10 days at 37°C whereas 96% release was obtained at 42°C. A concentration of 0.5% OA-Fe3O4 heated the matrix to 42.3 and 45.5°C within 5 min and 10 min of AMF exposure, respectively. The in vitro NF release profiles form the monoglycerides matrix containing 0.5% OA-Fe3O4 nanoparticles after AMF activation confirmed the thermo-responsive nature of the matrix that could provide pulsatile drug release 'on-demand'.

CH stretching vibration of N-methylformamide as a sensitive probe of its complexation: infrared matrix isolation and computational study.

PubMed

Sałdyka, M; Mielke, Z; Mierzwicki, K; Coussan, S; Roubin, P

2011-08-21

The complexes between trans-N-methylformamide (t-NMF) and Ar, N(2), CO, H(2)O have been studied by infrared matrix isolation spectroscopy and/or ab initio calculations. The infrared spectra of NMF/Ne, NMF/Ar and NMF/N(2)(CO,H(2)O)/Ar matrices have been measured and the effect of the complexation on the perturbation of t-NMF frequencies was analyzed. The geometries of the complexes formed between t-NMF and Ar, N(2), CO and H(2)O were optimized in two steps at the MP2/6-311++G(2d,2p) level of theory. The four structures, found for every system at this level, were reoptimized on the CP-corrected potential energy surface; both normal and CP corrected harmonic frequencies and intensities were calculated. For every optimized structure the interaction energy was partitioned according to the SAPT scheme and the topological distribution of the charge density (AIM theory) was performed. The analysis of the experimental and theoretical results indicates that the t-NMF-N(2) and CO complexes present in the matrices are stabilized by very weak N-H···N and N-H···C hydrogen bonds in which the N-H group of t-NMF serves as a proton donor. In turn, the t-NMF-H(2)O complex present in the matrix is stabilized by O-H···O(C) hydrogen bonding in which the carbonyl group of t-NMF acts as a proton acceptor. Both, the theoretical and experimental results indicate that involvement of the NH group of t-NMF in formation of very weak hydrogen bonds with the N(2) or CO molecules leads to a clearly noticeable red shift of the CH stretching wavenumber whereas engagement of the CO group as a proton acceptor triggers a blue shift of this wavenumber.

Molecular events involved in the increased expression of matrix metalloproteinase-9 by T lymphocytes of mammary tumor-bearing mice.

PubMed

Owen, Jennifer L; Torroella-Kouri, Marta; Iragavarapu-Charyulu, Vijaya

2008-01-01

Matrix metalloproteinases (MMPs) are a family of extracellular proteinases whose contributions to cancer progression have been studied because of their matrix-degrading abilities and elevated expression in advanced stage tumors. Recent findings suggest a role for MMPs during the multiple stages of tumor progression including establishment and growth, migration, invasion, metastasis, and angiogenesis. MMP-9 regulation at the molecular level can be studied by measuring the effect(s) of a variety of physiological and pharmacological agents on cells. Multiple signaling molecules such as protein kinase C, pertussis toxin-sensitive guanine nucleotide-binding protein G, and protein tyrosine kinases are known to mediate the secretion of MMPs in cell lines. We previously reported an upregulation of MMP-9 in T cells of mammary tumor-bearing mice. In this study, pharmacologic inhibitors were used to dissect the signaling pathways involved in the upregulation of MMP-9 in the splenic T cells of normal and mammary tumor-bearing mice. Staurosporine, a protein kinase inhibitor, stimulated MMP-9 secretion by normal T lymphocytes, while the constitutively high levels of MMP-9 produced by tumor bearers' T cells were decreased by Genistein, a specific tyrosine kinase inhibitor, and Rottlerin, a PKC inhibitor. Using a NF-kappaB specific probe to the murine MMP-9 promoter, electromobility shift assays of nuclear proteins from normal and tumor bearers' splenic T cells revealed a pattern of higher intensity bands from the tumor bearers' nuclear extracts, indicating a greater amount of these transcription factors bound to the recognition motif. When mammary tumor bearers' T cells were cultured with the NF-kappaB inhibitors, N-p-Tosyl-L-lysine chloromethyl ketone hydrochloride and Bay 11-7082, there was a subsequent decreased production of MMP-9. These results suggest that the tumor burden may be activating various signaling pathways within splenic T lymphocytes to upregulate MMP-9 expression.

Tissue plasminogen activator (tPA) and matrix metalloproteinases in the pathogenesis of stroke: therapeutic strategies.

PubMed

Adibhatla, Rao Muralikrishna; Hatcher, James F

2008-06-01

Today there exists only one FDA-approved treatment for ischemic stroke; i.e., the serine protease tissue-type plasminogen activator (tPA). In the aftermath of the failed stroke clinical trials with the nitrone spin trap/radical scavenger, NXY-059, a number of articles raised the question: are we doing the right thing? Is the animal research truly translational in identifying new agents for stroke treatment? This review summarizes the current state of affairs with plasminogen activators in thrombolytic therapy. In addition to therapeutic value, potential side effects of tPA also exist that aggravate stroke injury and offset the benefits provided by reperfusion of the occluded artery. Thus, combinational options (ultrasound alone or with microspheres/nanobubbles, mechanical dissociation of clot, activated protein C (APC), plasminogen activator inhibitor-1 (PAI-1), neuroserpin and CDP-choline) that could offset tPA toxic side effects and improve efficacy are also discussed here. Desmoteplase, a plasminogen activator derived from the saliva of Desmodus rotundus vampire bat, antagonizes vascular tPA-induced neurotoxicity by competitively binding to low-density lipoprotein related-receptors (LPR) at the blood-brain barrier (BBB) interface, minimizing the tPA uptake into brain parenchyma. tPA can also activate matrix metalloproteinases (MMPs), a family of endopeptidases comprised of 24 mammalian enzymes that primarily catalyze the turnover and degradation of the extracellular matrix (ECM). MMPs have been implicated in BBB breakdown and neuronal injury in the early times after stroke, but also contribute to vascular remodeling, angiogenesis, neurogenesis and axonal regeneration during the later repair phase after stroke. tPA, directly or by activation of MMP-9, could have beneficial effects on recovery after stroke by promoting neurovascular repair through vascular endothelial growth factor (VEGF). However, any treatment regimen directed at MMPs must consider their pleiotropic nature and the likelihood of either beneficial or detrimental effects that might depend on the timing of the treatment in relation to the stage of brain injury.

SOURCE APPORTIONMENT OF PM 2.5 AND CARBON IN SEATTLE USING CHEMICAL MASS BALANCE AND POSITIVE MATRIX FACTORIZATION

EPA Science Inventory

Three years of PM2.5 speciated data were collected and chemically analyzed using the IMPROVE protocol at the Beacon Hill site in Seattle. The data were analyzed by the Chemical Mass Balance Version 8 (CMB8) and Positive Matrix Factorization (PMF) source apportionment models. T...

Modeling Radioactive Decay Chains with Branching Fraction Uncertainties

DTIC Science & Technology

2013-03-01

moments methods with transmutation matrices. Uncertainty from both half-lives and branching fractions is carried through these calculations by Monte...moment methods, method for sampling from normal distributions for half- life uncertainty, and use of transmutation matrices were leveraged. This...distributions for half-life and branching fraction uncertainties, building decay chains and generating the transmutation matrix (T-matrix

Alteration of the bone tissue material properties in type 1 diabetes mellitus: A Fourier transform infrared microspectroscopy study.

PubMed

Mieczkowska, Aleksandra; Mansur, Sity Aishah; Irwin, Nigel; Flatt, Peter R; Chappard, Daniel; Mabilleau, Guillaume

2015-07-01

Type 1 diabetes mellitus (T1DM) is a severe disorder characterized by hyperglycemia and hypoinsulinemia. A higher occurrence of bone fractures has been reported in T1DM, and although bone mineral density is reduced in this disorder, it is also thought that bone quality may be altered in this chronic pathology. Vibrational microscopies such as Fourier transform infrared microspectroscopy (FTIRM) represent an interesting approach to study bone quality as they allow investigation of the collagen and mineral compartment of the extracellular matrix in a specific bone location. However, as spectral feature arising from the mineral may overlap with those of the organic component, the demineralization of bone sections should be performed for a full investigation of the organic matrix. The aims of the present study were to (i) develop a new approach, based on the demineralization of thin bone tissue section to allow a better characterization of the bone organic component by FTIRM, (ii) to validate collagen glycation and collagen integrity in bone tissue and (iii) to better understand what alterations of tissue material properties in newly forming bone occur in T1DM. The streptozotocin-injected mouse (150 mg/kg body weight, injected at 8 weeks old) was used as T1DM model. Animals were randomly allocated to control (n = 8) or diabetic (n = 10) groups and were sacrificed 4 weeks post-STZ injection. Bones were collected at necropsy, embedded in polymethylmethacrylate and sectioned prior to examination by FTIRM. FTIRM collagen parameters were collagen maturity (area ratio between 1660 and 1690 cm(-1) subbands), collagen glycation (area ratio between the 1032 cm(-1) subband and amide I) and collagen integrity (area ratio between the 1338 cm(-1) subband and amide II). No significant differences in the mineral compartment of the bone matrix could be observed between controls and STZ-injected animals. On the other hand, as compared with controls, STZ-injected animals presented with significant higher value for collagen maturity (17%, p = 0.0048) and collagen glycation (99%, p = 0.0121), while collagen integrity was significantly lower by 170% (p = 0.0121). This study demonstrated the profound effect of early T1DM on the organic compartment of the bone matrix in newly forming bone. Further studies in humans are required to ascertain whether T1DM also lead to similar effect on the quality of the bone matrix. Copyright © 2015 Elsevier Inc. All rights reserved.

A Numerically Subdominant CD8 T Cell Response to Matrix Protein of Respiratory Syncytial Virus Controls Infection with Limited Immunopathology

PubMed Central

Liu, Jie; Haddad, Elias K.; Marceau, Joshua; Morabito, Kaitlyn M.; Rao, Srinivas S.; Filali-Mouhim, Ali; Sekaly, Rafick-Pierre; Graham, Barney S.

2016-01-01

CD8 T cells are involved in pathogen clearance and infection-induced pathology in respiratory syncytial virus (RSV) infection. Studying bulk responses masks the contribution of individual CD8 T cell subsets to protective immunity and immunopathology. In particular, the roles of subdominant responses that are potentially beneficial to the host are rarely appreciated when the focus is on magnitude instead of quality of response. Here, by evaluating CD8 T cell responses in CB6F1 hybrid mice, in which multiple epitopes are recognized, we found that a numerically subdominant CD8 T cell response against DbM187 epitope of the virus matrix protein expressed high avidity TCR and enhanced signaling pathways associated with CD8 T cell effector functions. Each DbM187 T effector cell lysed more infected targets on a per cell basis than the numerically dominant KdM282 T cells, and controlled virus replication more efficiently with less pulmonary inflammation and illness than the previously well-characterized KdM282 T cell response. Our data suggest that the clinical outcome of viral infections is determined by the integrated functional properties of a variety of responding CD8 T cells, and that the highest magnitude response may not necessarily be the best in terms of benefit to the host. Understanding how to induce highly efficient and functional T cells would inform strategies for designing vaccines intended to provide T cell-mediated immunity. PMID:26943673

Interaction effects in Aharonov-Bohm-Kondo rings

NASA Astrophysics Data System (ADS)

Komijani, Yashar; Yoshii, Ryosuke; Affleck, Ian

2013-12-01

We study the conductance through an Aharonov-Bohm ring, containing a quantum dot in the Kondo regime in one arm, at finite temperature and arbitrary electronic density. We develop a general method for this calculation based on changing the basis to the screening and nonscreening channels. We show that an unusual term appears in the conductance, involving the connected four-point Green's function of the conduction electrons. However, this term and the terms quadratic in the T matrix can be eliminated at sufficiently low temperatures, leading to an expression for the conductance linear in the Kondo T matrix. Explicit results are given for temperatures that are high compared to the Kondo temperature.

Coherent Backscattering by Polydisperse Discrete Random Media: Exact T-Matrix Results

NASA Technical Reports Server (NTRS)

Mishchenko, Michael I.; Dlugach, Janna M.; Mackowski, Daniel W.

2011-01-01

The numerically exact superposition T-matrix method is used to compute, for the first time to our knowledge, electromagnetic scattering by finite spherical volumes composed of polydisperse mixtures of spherical particles with different size parameters or different refractive indices. The backscattering patterns calculated in the far-field zone of the polydisperse multiparticle volumes reveal unequivocally the classical manifestations of the effect of weak localization of electromagnetic waves in discrete random media, thereby corroborating the universal interference nature of coherent backscattering. The polarization opposition effect is shown to be the least robust manifestation of weak localization fading away with increasing particle size parameter.

Residual Strength after Fatigue of Unidirectional and Cross-Ply Metal Matrix Composites at Elevated Temperature

DTIC Science & Technology

1996-06-01

MPO)SIT[lS A’l’ 1’IIVA tI , P R T 1R , ’[II?,I Scil.’’/e Cliou . Major, 1R. C ). 0’. ARMY AFIT/ GAE / ENY I 9(’ , 96-01650 DEPARTMENT OF THE AIR FORCE...UNIDIRECTIONAL AND CROSS-PLY METAL MATRIX COMPOSITES AT ELEVATED TEMPERATURE THESISp Sen-Tzcr Chiou, Major, R. 0. C ., ARMY AFIT GAE ENY 96 J-2 Approved for...for the Degree of’ Master of Sciene in Aeronautical Engince. ing Sen-Tzer ChioLu. Major, R. 0. C ., ARMY June, 1996 Approved for public release

MS&T'13 Symposium Preview: Metal and Polymer Matrix Composites

NASA Astrophysics Data System (ADS)

Gupta, Nikhil; Paramsothy, Muralidharan

2013-08-01

The Metal and Polymer Matrix Composites symposium at Materials Science & Technology 2013 (MS&T'13) conference is planned to provide a platform to researchers working on various aspects of composite materials and capture the state of the art in this area. The dialogue among leading researchers is expected to provide insight into the future of this field and identify the future directions in terms of research, development, and applications of composite materials. In the 2 day program, the symposium includes 34 presentations, including 10 invited presentations. The contributions have come from 16 different countries including USA, Mexico, Switzerland, India, Egypt, and Singapore.

JaSTA-2: Second version of the Java Superposition T-matrix Application

NASA Astrophysics Data System (ADS)

Halder, Prithish; Das, Himadri Sekhar

2017-12-01

In this article, we announce the development of a new version of the Java Superposition T-matrix App (JaSTA-2), to study the light scattering properties of porous aggregate particles. It has been developed using Netbeans 7.1.2, which is a java integrated development environment (IDE). The JaSTA uses double precision superposition T-matrix codes for multi-sphere clusters in random orientation, developed by Mackowski and Mischenko (1996). The new version consists of two options as part of the input parameters: (i) single wavelength and (ii) multiple wavelengths. The first option (which retains the applicability of older version of JaSTA) calculates the light scattering properties of aggregates of spheres for a single wavelength at a given instant of time whereas the second option can execute the code for a multiple numbers of wavelengths in a single run. JaSTA-2 provides convenient and quicker data analysis which can be used in diverse fields like Planetary Science, Atmospheric Physics, Nanoscience, etc. This version of the software is developed for Linux platform only, and it can be operated over all the cores of a processor using the multi-threading option.

Graph regularized nonnegative matrix factorization for temporal link prediction in dynamic networks

NASA Astrophysics Data System (ADS)

Ma, Xiaoke; Sun, Penggang; Wang, Yu

2018-04-01

Many networks derived from society and nature are temporal and incomplete. The temporal link prediction problem in networks is to predict links at time T + 1 based on a given temporal network from time 1 to T, which is essential to important applications. The current algorithms either predict the temporal links by collapsing the dynamic networks or collapsing features derived from each network, which are criticized for ignoring the connection among slices. to overcome the issue, we propose a novel graph regularized nonnegative matrix factorization algorithm (GrNMF) for the temporal link prediction problem without collapsing the dynamic networks. To obtain the feature for each network from 1 to t, GrNMF factorizes the matrix associated with networks by setting the rest networks as regularization, which provides a better way to characterize the topological information of temporal links. Then, the GrNMF algorithm collapses the feature matrices to predict temporal links. Compared with state-of-the-art methods, the proposed algorithm exhibits significantly improved accuracy by avoiding the collapse of temporal networks. Experimental results of a number of artificial and real temporal networks illustrate that the proposed method is not only more accurate but also more robust than state-of-the-art approaches.

Expression of small leucine-rich extracellular matrix proteoglycans biglycan and lumican reveals oral lichen planus malignant potential.

PubMed

Lončar-Brzak, Božana; Klobučar, Marko; Veliki-Dalić, Irena; Sabol, Ivan; Kraljević Pavelić, Sandra; Krušlin, Božo; Mravak-Stipetić, Marinka

2018-03-01

The aim of this study was to examine molecular alterations on the protein level in lesions of oral lichen planus (OLP), oral squamous cell carcinoma (OSCC) and healthy mucosa. Global protein profiling methods based on liquid chromatography coupled to mass spectrometry (LC-MS) were used, with a special emphasis on evaluation of deregulated extracellular matrix molecules expression, as well as on analyses of IG2F and IGFR2 expression in healthy mucosa, OLP and OSCC tissues by comparative semi-quantitative immunohistochemistry. Mass spectrometry-based proteomics profiling of healthy mucosa, OLP and OSCC tissues (and accompanied histologically unaltered tissues, respectively) identified 55 extracellular matrix proteins. Twenty among identified proteins were common to all groups of samples. Expression of small leucine-rich extracellular matrix proteoglycans lumican and biglycan was found both in OSCC and OLP and they were validated by Western blot analysis as putative biomarkers. A significant increase (p < 0.05) of biglycan expression in OLP-AT group was determined in comparison with OLP-T group, while lumican showed significant up-regulation (p < 0.05) in OLP-T and OSCC-T groups vs. adjacent and control tissue groups. Biglycan expression was only determined in OSCC-AT group. Immunohistochemical analysis of IGF2 and IG2FR expression revealed no significant difference among groups of samples. Biglycan and lumican were identified as important pathogenesis biomarkers of OLP that point to its malignant potential.

Matrix metalloproteinase-1 and matrix metalloproteinase-12 gene polymorphisms and the risk of ischemic stroke in a Tunisian population.

PubMed

Chehaibi, Khouloud; Hrira, Mohamed Yahia; Nouira, Samir; Maatouk, Faouzi; Ben Hamda, Khaldoun; Slimane, Mohamed Naceur

2014-07-15

Matrix metalloproteinases (MMPs) play an important role in early atherosclerosis, extracellular matrix remodeling, plaque rupture and myocardial infarction. MMP gene polymorphisms contribute to the risk of developing cardiovascular diseases. In this study, we investigated, for the first time, the association between MMP-1-16071G/2G, MMP-12 -82A/G and MMP-12 1082A/G genotypes and haplotypes and the risk of ischemic stroke (IS) among patients with type 2 diabetes mellitus (T2DM). To examine whether these genetic polymorphisms are associated with susceptibility to IS, 196 patients with IS and 192 controls were examined by PCR-based RFLP. When the analyses were adjusted for multiple risk factors, no interaction between T2DM and MMP-1-1607 1G/2G polymorphism on the risk of ischemic stroke was found (p=0.074). However, MMP-12 polymorphisms genotypes were associated with the higher risk of IS in diabetic patients compared with total patients. The -82G-1082G haplotype of MMP-12 polymorphisms was associated with higher risk of ischemic stroke in diabetic patients [AOR=2.33; 95% CI (1.25-3.62), P=0.032]. These findings showed that there was an important joint effect of the MMP-12 polymorphisms and T2DM on the risk of IS and therefore it can be considered as a potential marker of cerebrovascular disorders in diabetic patients. Copyright © 2014 Elsevier B.V. All rights reserved.

Moisture Absorption of Epoxy Matrix Composites Immersed in Liquids and in Humid Air.

DTIC Science & Technology

1979-10-01

Eq. 4). -34- TEMPERATURE, T (K) 165 40 350 300 Neat ResinA / Fit to Data 0\\ 0 o Composite Calculated 0- Data Delasi and Whiteside (1977) 168 AS/3501...moisture ab - sorption characteristics of T300/1034, AS/3501-5 and T300/5208 graphite-epoxy composites. 1) Material immersed in liquid at temperatures 300 to

Toric Calabi-Yau threefolds as quantum integrable systems. R-matrix and RTT relations

NASA Astrophysics Data System (ADS)

Awata, Hidetoshi; Kanno, Hiroaki; Mironov, Andrei; Morozov, Alexei; Morozov, Andrey; Ohkubo, Yusuke; Zenkevich, Yegor

2016-10-01

R-matrix is explicitly constructed for simplest representations of the Ding-Iohara-Miki algebra. Calculation is straightforward and significantly simpler than the one through the universal R-matrix used for a similar calculation in the Yangian case by A. Smirnov but less general. We investigate the interplay between the R-matrix structure and the structure of DIM algebra intertwiners, i.e. of refined topological vertices and show that the R-matrix is diagonalized by the action of the spectral duality belonging to the SL(2, ℤ) group of DIM algebra automorphisms. We also construct the T-operators satisfying the RTT relations with the R-matrix from refined amplitudes on resolved conifold. We thus show that topological string theories on the toric Calabi-Yau threefolds can be naturally interpreted as lattice integrable models. Integrals of motion for these systems are related to q-deformation of the reflection matrices of the Liouville/Toda theories.

Quantitative T2-Mapping and T2⁎-Mapping Evaluation of Changes in Cartilage Matrix after Acute Anterior Cruciate Ligament Rupture and the Correlation between the Results of Both Methods

PubMed Central

Tao, Hongyue; Qiao, Yang; Hu, Yiwen; Xie, Yuxue; Lu, Rong; Yan, Xu

2018-01-01

Objectives To quantitatively assess changes in cartilage matrix after acute anterior cruciate ligament (ACL) rupture using T2- and T2⁎-mapping and analyze the correlation between the results of both methods. Methods Twenty-three patients and 23 healthy controls were enrolled and underwent quantitative MRI examination. The knee cartilage was segmented into six compartments, including lateral femur (LF), lateral tibia (LT), medial femur (MF), medial tibia (MT), trochlea (Tr), and patella (Pa). T2 and T2⁎ values were measured in full-thickness as well as superficial and deep layers of each cartilage compartment. Differences of T2 and T2⁎ values between patients and controls were compared using unpaired Student's t-test, and the correlation between their reciprocals was analyzed using Pearson's correlation coefficient. Results ACL-ruptured patients showed higher T2 and T2⁎ values in full-thickness and superficial layers of medial and lateral tibiofemoral joint. Meanwhile, patients exhibited higher T2⁎ values in deep layers of lateral tibiofemoral joint. The elevated percentages of T2 and T2⁎ value in superficial LT were most significant (20.738%, 17.525%). The reciprocal of T2⁎ value was correlated with that of T2 value (r = 0.886, P < 0.001). Conclusion The early degeneration could occur in various knee cartilage compartments after acute ACL rupture, especially in the superficial layer of LT. T2⁎-mapping might be more sensitive in detecting deep layer of cartilage than T2-mapping. PMID:29888279

Improved Graphite Fiber/Acetylene Terminated Matrix Resin Prepreg Products

DTIC Science & Technology

1988-03-01

AFWAL-TR-80-4151, "The Synthesis of Polymer Precursor and Exploratory Research Based on Acetylene Displacement Reaction," E.T. Sabourin , Gulf...Acetylene Terminated Quinoxalines," E.T. Sabourin , Gulf Research and Development Co., July 1982. ACETYLENE TERMINATED TECHNOLOGY BIBLIOGRAPHY SYNTHESIS AND

Effect of electronic coupling of Watson-Crick hopping in DNA poly(dA)-poly(dT)

NASA Astrophysics Data System (ADS)

Risqi, A. M.; Yudiarsah, E.

2017-07-01

Charge transport properties of poly(dA)-poly(dT) DNA has been studied by using thigh binding Hamiltonian approach. Molecule DNA that we use consist of 32 base pair of adenine (A) and thymine (T) and backbone is consist of phosphate and sugar. The molecule DNA is contacted electrode at both ends. Charge transport in molecule DNA depend on the environment, we studied the effect of electronic coupling of Watson-Crick hopping in poly(dA)-poly(dT) DNA to transmission probability and characteristic I-V. The electronic coupling constant influence charge transport between adenine-thymine base pairs at the same site. Transmission probability is studied by using transfer matrix and scattering matrix method, and the result of transmission probability is used to calculate the characteristic I-V by using formula Landauer Buttiker. The result shows that when the electronic coupling increase then transmission probability and characteristic I-V increase slightly.

On evolutionary spatial heterogeneous games

NASA Astrophysics Data System (ADS)

Fort, H.

2008-03-01

How cooperation between self-interested individuals evolve is a crucial problem, both in biology and in social sciences, that is far from being well understood. Evolutionary game theory is a useful approach to this issue. The simplest model to take into account the spatial dimension in evolutionary games is in terms of cellular automata with just a one-parameter payoff matrix. Here, the effects of spatial heterogeneities of the environment and/or asymmetries in the interactions among the individuals are analysed through different extensions of this model. Instead of using the same universal payoff matrix, bimatrix games in which each cell at site ( i, j) has its own different ‘temptation to defect’ parameter T(i,j) are considered. First, the case in which these individual payoffs are constant in time is studied. Second, an evolving evolutionary spatial game such that T=T(i,j;t), i.e. besides depending on the position evolves (by natural selection), is used to explore the combination of spatial heterogeneity and natural selection of payoff matrices.

Accurate Exchange-Correlation Energies for the Warm Dense Electron Gas.

PubMed

Malone, Fionn D; Blunt, N S; Brown, Ethan W; Lee, D K K; Spencer, J S; Foulkes, W M C; Shepherd, James J

2016-09-09

The density matrix quantum Monte Carlo (DMQMC) method is used to sample exact-on-average N-body density matrices for uniform electron gas systems of up to 10^{124} matrix elements via a stochastic solution of the Bloch equation. The results of these calculations resolve a current debate over the accuracy of the data used to parametrize finite-temperature density functionals. Exchange-correlation energies calculated using the real-space restricted path-integral formalism and the k-space configuration path-integral formalism disagree by up to ∼10% at certain reduced temperatures T/T_{F}≤0.5 and densities r_{s}≤1. Our calculations confirm the accuracy of the configuration path-integral Monte Carlo results available at high density and bridge the gap to lower densities, providing trustworthy data in the regime typical of planetary interiors and solids subject to laser irradiation. We demonstrate that the DMQMC method can calculate free energies directly and present exact free energies for T/T_{F}≥1 and r_{s}≤2.

Schwarzschild radius from Monte Carlo calculation of the Wilson loop in supersymmetric matrix quantum mechanics.

PubMed

Hanada, Masanori; Miwa, Akitsugu; Nishimura, Jun; Takeuchi, Shingo

2009-05-08

In the string-gauge duality it is important to understand how the space-time geometry is encoded in gauge theory observables. We address this issue in the case of the D0-brane system at finite temperature T. Based on the duality, the temporal Wilson loop W in gauge theory is expected to contain the information of the Schwarzschild radius RSch of the dual black hole geometry as log(W)=RSch/(2pialpha'T). This translates to the power-law behavior log(W)=1.89(T/lambda 1/3)-3/5, where lambda is the 't Hooft coupling constant. We calculate the Wilson loop on the gauge theory side in the strongly coupled regime by performing Monte Carlo simulations of supersymmetric matrix quantum mechanics with 16 supercharges. The results reproduce the expected power-law behavior up to a constant shift, which is explainable as alpha' corrections on the gravity side. Our conclusion also demonstrates manifestly the fuzzball picture of black holes.

Droplet Evolution and Refinement During Liquid-Liquid Decomposition of Zn-6 Wt Pct Bi Immiscible Alloy Under High Static Magnetic Fields

NASA Astrophysics Data System (ADS)

Zheng, Tianxiang; Zhong, Yunbo; Wang, Jiang; Ren, Zhongming; Ren, Weili; Lei, Zuosheng; Debray, Francois; Beaugnon, Eric; Wei, Xicheng

2018-05-01

In situ solidification experiments on Zn-6 wt pct Bi immiscible alloys were conducted to investigate the droplet evolution under high static magnetic fields (HSMFs). The results showed that a microstructure with extremely fine Bi-rich particles distributed in the matrix can be obtained under an HSMF of 29 T. The average diameter of the Bi-rich phase decreased with the increasing magnetic flux density. Stokes sedimentation disappeared when the HSMF was larger than 18 T. Starting at an HSMF of 18 T, Bi-rich droplets grew via pure diffusion in the liquid matrix. The HSMF decreased the spacing of the droplet arrays when the cooling rate (R) was approximately 1600 °C/min. The formation of a Zn-rich phase surrounded by a Bi-rich shell at HSMFs below 18 T, when R was approximately 60 °C/min, was attributed to the thermoelectric magnetic force.

Engineering a collagen matrix that replicates the biological properties of native extracellular matrix.

PubMed

Nam, Kwangwoo; Sakai, Yuuki; Funamoto, Seiichi; Kimura, Tsuyoshi; Kishida, Akio

2011-01-01

In this study, we aimed to replicate the function of native tissues that can be used in tissue engineering and regenerative medicine. The key to such replication is the preparation of an artificial collagen matrix that possesses a structure resembling that of the extracellular matrix. We, therefore, prepared a collagen matrix by fibrillogenesis in a NaCl/Na(2)HPO(4) aqueous solution using a dialysis cassette and investigated its biological behavior in vitro and in vivo. The in vitro cell adhesion and proliferation did not show any significant differences. The degradation rate in the living body could be controlled according to the preparation condition, where the collagen matrix with high water content (F-collagen matrix, >98%) showed fast degradation and collagen matrix with lower water content (T-collagen matrix, >80%) showed no degradation for 8 weeks. The degradation did not affect the inflammatory response at all and relatively faster wound healing response was observed. Comparing this result with that of collagen gel and decellularized cornea, it can be concluded that the structural factor is very important and no cell abnormal behavior would be observed for quaternary structured collagen matrix.

The Eclectic Simulator Program (ESP) Usage Guide.

DTIC Science & Technology

1980-05-01

DataStorage and H-5.1 1-t- Transmission.) For example, the columns of a 3 x 3 matrix BMAT could be declared on an *INFORM card as: ’ INFORM 3 1 BMAT (1,J...but not the rows: *INFORM 1 3 BMAT (J, 1) $ because the data in a matrix row is not stored contiguously. In other words, BMAT (J, 1) is the starting...location for an array of the 3 next elements in storage, and since FORTRAN always stores a matrix such as BMAT by columns, a reference to BMAT (J, 1

The Effects of Simulated Micro-gravity on Cultured Chicken Embryonic Chondrocytes

NASA Astrophysics Data System (ADS)

Li, X.; Zhang, X.; Yang, S.; Li, S.; Peidong, J.; Lin, Z.

T he effects of simulated microgravity on the microtubular system, extracellular matrix, alkaline phosphatase activity, intracellular free calcium concentration, mitochondrial ATP synthase activity and oligomycin inhibition rate of cultured chicken embryonic chondrocytes were studied with a clinostat. The microtubular content decreased. The extracellualr matrix decreased significantly after rotating, and the fibers in the extracellular matrix were more tiny and disorderly. There was a time course decrease in alkaline phosphatase activity of chondrocytes, a marker of matrix mineralization. Meanwhile a significant drop in the intracellular calcium concentration happened at the beginning of rotation. No significant changes happened in the mitochondrial ATP synthase activity and oligomycin inhibition rate. The possible mechanisms about them were discussed.

Formulation of a Nonlinear, Compatible Finite Element for the Analysis of Laminated Composites.

DTIC Science & Technology

1982-12-01

be gained through weight savings are obvious. The other advantage, which is being exploited in the design of the forward swept wing (2), is the...components of strain can also be represented in matrix form, ’-. fe t [LJfjut W’here + ~(3.211) The L - operator matrix can be broken down into linear, Loand

"They Won't Let Us Play ... Unless You're Going out with One of Them": Girls, Boys and Butler's "Heterosexual Matrix" in the Primary Years

ERIC Educational Resources Information Center

Renold, Emma

2006-01-01

Judith Butler's conceptualisation of how gender is routinely spoken through a hegemonic heterosexual matrix has been pivotal for many social scientists researching within and beyond educational settings for exposing the ways in which children's normative gender identities ("intelligible genders") are inextricably tied to dominant notions of…

Electroluminescence from completely horizontally oriented dye molecules

DOE Office of Scientific and Technical Information (OSTI.GOV)

Komino, Takeshi; Center for Organic Photonics and Electronics Research, Kyushu University, 744 Motooka, Nishi, Fukuoka 819-0395; Japan Science and Technology Agency, ERATO, Adachi Molecular Exciton Engineering Project, 744 Motooka, Nishi, Fukuoka 819-0395

2016-06-13

A complete horizontal molecular orientation of a linear-shaped thermally activated delayed fluorescent guest emitter 2,6-bis(4-(10Hphenoxazin-10-yl)phenyl)benzo[1,2-d:5,4-d′] bis(oxazole) (cis-BOX2) was obtained in a glassy host matrix by vapor deposition. The orientational order of cis-BOX2 depended on the combination of deposition temperature and the type of host matrix. Complete horizontal orientation was obtained when a thin film with cis-BOX2 doped in a 4,4′-bis(N-carbazolyl)-1,1′-biphenyl (CBP) host matrix was fabricated at 200 K. The ultimate orientation of guest molecules originates from not only the kinetic relaxation but also the kinetic stability of the deposited guest molecules on the film surface during film growth. Utilizing the ultimatemore » orientation, a highly efficient organic light-emitting diode with the external quantum efficiency of 33.4 ± 2.0% was realized. The thermal stability of the horizontal orientation of cis-BOX2 was governed by the glass transition temperature (T{sub g}) of the CBP host matrix; the horizontal orientation was stable unless the film was annealed above T{sub g}.« less

Brueckner G -matrix approach for neutron-proton pairing correlations in the deformed BCS approach

NASA Astrophysics Data System (ADS)

Ha, Eunja; Cheoun, Myung-Ki; Šimkovic, F.

2015-10-01

Ground states of even-even Ge isotopes with mass number A =64 -76 have been studied in the deformed Bardeen-Cooper-Schrieffer (BCS) theory by taking neutron-proton (n p ) pairing correlations as well as neutron-neutron (n n ) and proton-proton (p p ) pairing correlations. The n p pairing has two different modes J =0 ,T =1 (isotriplet) and J =1 ,T =0 (isosinglet). In this work, the Brueckner G matrix, based on the CD-Bonn potential, has been exploited to reduce the ambiguity regarding nucleon-nucleon interactions inside nuclei compared to the results by a simple schematic phenomenological force. We found that the G matrix plays important roles to obtain reasonable descriptions of even-even nuclei compared to the schematic force. The n p pairing strength has been shown to have a clear correlation with quadrupole deformation parameter β2 for the isotopes, and affects the smearing of the Fermi surfaces of not only N =Z nuclei but also N ≠Z nuclei. In particular, the coexistence of the like particle (n n and p p ) and the n p pairing modes was found to become more salient by the G -matrix approach than by the schematic force approach.

Properties of five toughened matrix composite materials

NASA Technical Reports Server (NTRS)

Cano, Roberto J.; Dow, Marvin B.

1992-01-01

The use of toughened matrix composite materials offers an attractive solution to the problem of poor damage tolerance associated with advanced composite materials. In this study, the unidirectional laminate strengths and moduli, notched (open-hole) and unnotched tension and compression properties of quasi-isotropic laminates, and compression-after-impact strengths of five carbon fiber/toughened matrix composites, IM7/E7T1-2, IM7/X1845, G40-800X/5255-3, IM7/5255-3, and IM7/5260 have been evaluated. The compression-after-impact (CAI) strengths were determined primarily by impacting quasi-isotropic laminates with the NASA Langley air gun. A few CAI tests were also made with a drop-weight impactor. For a given impact energy, compression after impact strengths were determined to be dependent on impactor velocity. Properties and strengths for the five materials tested are compared with NASA data on other toughened matrix materials (IM7/8551-7, IM6/1808I, IM7/F655, and T800/F3900). This investigation found that all five materials were stronger and more impact damage tolerant than more brittle carbon/epoxy composite materials currently used in aircraft structures.

Infrared spectroscopy of water clusters isolated in methane matrices: Effects of isotope substitution and annealing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yamakawa, Koichiro, E-mail: koichiro.yamakawa@gakushuin.ac.jp; Ehara, Namika; Ozawa, Nozomi

2016-07-15

Using infrared-active solvents of CH{sub 4} and CD{sub 4} for matrix isolation, we measured infrared spectra of H{sub 2}O and D{sub 2}O clusters at 7 K. The solute-concentration dependence of the spectrum of H{sub 2}O clusters in a CH{sub 4} matrix was investigated and was used for the peak assignment. Annealing procedures were found to promote the size growth of water clusters in methane matrices for all the combinations of (H{sub 2}O, CH{sub 4}), (H{sub 2}O, CD{sub 4}), (D{sub 2}O, CH{sub 4}), and (D{sub 2}O, CD{sub 4}). We also monitored the ν{sub 3} absorption due to methane to find themore » annealing-induced structural change only of solid CH{sub 4}. The matrix effects on the vibrations of the clusters are discussed on the basis of “T{sub c} plots”, where their frequencies are plotted as a function of the square root of the matrix critical temperature, T{sub c}. The obtained plots assure the validity of the assignment of the cluster peaks.« less

Quantifying fluctuations in economic systems by adapting methods of statistical physics

NASA Astrophysics Data System (ADS)

Stanley, H. E.; Gopikrishnan, P.; Plerou, V.; Amaral, L. A. N.

2000-12-01

The emerging subfield of econophysics explores the degree to which certain concepts and methods from statistical physics can be appropriately modified and adapted to provide new insights into questions that have been the focus of interest in the economics community. Here we give a brief overview of two examples of research topics that are receiving recent attention. A first topic is the characterization of the dynamics of stock price fluctuations. For example, we investigate the relation between trading activity - measured by the number of transactions NΔ t - and the price change GΔ t for a given stock, over a time interval [t, t+ Δt] . We relate the time-dependent standard deviation of price fluctuations - volatility - to two microscopic quantities: the number of transactions NΔ t in Δ t and the variance WΔ t2 of the price changes for all transactions in Δ t. Our work indicates that while the pronounced tails in the distribution of price fluctuations arise from WΔ t, the long-range correlations found in ∣ GΔ t∣ are largely due to NΔ t. We also investigate the relation between price fluctuations and the number of shares QΔ t traded in Δ t. We find that the distribution of QΔ t is consistent with a stable Lévy distribution, suggesting a Lévy scaling relationship between QΔ t and NΔ t, which would provide one explanation for volume-volatility co-movement. A second topic concerns cross-correlations between the price fluctuations of different stocks. We adapt a conceptual framework, random matrix theory (RMT), first used in physics to interpret statistical properties of nuclear energy spectra. RMT makes predictions for the statistical properties of matrices that are universal, that is, do not depend on the interactions between the elements comprising the system. In physics systems, deviations from the predictions of RMT provide clues regarding the mechanisms controlling the dynamics of a given system, so this framework can be of potential value if applied to economic systems. We discuss a systematic comparison between the statistics of the cross-correlation matrix C - whose elements Cij are the correlation-coefficients between the returns of stock i and j - and that of a random matrix having the same symmetry properties. Our work suggests that RMT can be used to distinguish random and non-random parts of C; the non-random part of C, which deviates from RMT results provides information regarding genuine cross-correlations between stocks.

Development of a Lozenge for Oral Transmucosal Delivery of Trans-Resveratrol in Humans: Proof of Concept

PubMed Central

Blanchard, Otis L.; Friesenhahn, Gregory; Javors, Martin A.; Smoliga, James M.

2014-01-01

Resveratrol provides multiple physiologic benefits which promote healthspan in various model species and clinical trials support continued exploration of resveratrol treatment in humans. However, there remains concern regarding low bioavailability and wide inter-individual differences in absorption and metabolism in humans, which suggests a great need to develop novel methods for resveratrol delivery. We hypothesized that oral transmucosal delivery, using a lozenge composed of a resveratrol-excipient matrix, would allow resveratrol to be absorbed rapidly into the bloodstream. We pursued proof of concept through two experiments. In the first experiment, the solubility of trans-resveratrol (tRES) in water and 2.0 M solutions of dextrose, fructose, ribose, sucrose, and xylitol was determined using HPLC. Independent t-tests with a Bonferroni correction were used to compare the solubility of tRES in each of the solutions to that in water. tRES was significantly more soluble in the ribose solution (p = 0.0013) than in the other four solutions. Given the enhanced solubility of tRES in a ribose solution, a resveratrol-ribose matrix was developed into a lozenge suitable for human consumption. Lozenges were prepared, each containing 146±5.5 mg tRES per 2000 mg of lozenge mass. Two healthy human participants consumed one of the prepared lozenges following an overnight fast. Venipuncture was performed immediately before and 15, 30, 45, and 60 minutes following lozenge administration. Maximal plasma concentrations (C max) for tRES alone (i.e., resveratrol metabolites not included) were 325 and 332 ng⋅mL−1 for the two participants at 15 minute post-administration for both individuals. These results suggest a resveratrol-ribose matrix lozenge can achieve greater C max and enter the bloodstream faster than previously reported dosage forms for gastrointestinal absorption. While this study is limited by small sample size and only one method of resveratrol delivery, it does provide proof of concept to support further exploration of novel delivery methods for resveratrol administration. PMID:24587240

Characterization of the collagen component of cartilage repair tissue of the talus with quantitative MRI: comparison of T2 relaxation time measurements with a diffusion-weighted double-echo steady-state sequence (dwDESS).

PubMed

Kretzschmar, M; Bieri, O; Miska, M; Wiewiorski, M; Hainc, N; Valderrabano, V; Studler, U

2015-04-01

The purpose of this study was to characterize the collagen component of repair tissue (RT) of the talus after autologous matrix-induced chondrogenesis (AMIC) using quantitative T2 and diffusion-weighted imaging. Mean T2 values and diffusion coefficients of AMIC-RT and normal cartilage of the talus of 25 patients with posttraumatic osteochondral lesions and AMIC repair were compared in a cross-sectional design using partially spoiled steady-state free precession (pSSFP) for T2 quantification, and diffusion-weighted double-echo steady-state (dwDESS) for diffusion measurement. RT and cartilage were graded with modified Noyes and MOCART scores on morphological sequences. An association between follow-up interval and quantitative MRI measures was assessed using multivariate regression, after stratifying the cohort according to time interval between surgery and MRI. Mean T2 of the AMIC-RT and cartilage were 43.1 ms and 39.1 ms, respectively (p = 0.26). Mean diffusivity of the RT (1.76 μm(2)/ms) was significantly higher compared to normal cartilage (1.46 μm(2)/ms) (p = 0.0092). No correlation was found between morphological and quantitative parameters. RT diffusivity was lowest in the subgroup with follow-up >28 months (p = 0.027). Compared to T2-mapping, dwDESS demonstrated greater sensitivity in detecting differences in the collagen matrix between AMIC-RT and cartilage. Decreased diffusivity in patients with longer follow-up times may indicate an increased matrix organization of RT. • MRI is used to assess morphology of the repair tissue during follow-up. • Quantitative MRI allows an estimation of biochemical properties of the repair tissue. • Differences between repair tissue and cartilage were more significant with dwDESS than T2 mapping.

The MMP-9 -1562 C/T Polymorphism in the Presence of Metabolic Syndrome Increases the Risk of Clinical Events in Patients with Coronary Artery Disease

PubMed Central

Opstad, Trine B.; Arnesen, Harald; Pettersen, Alf Å.; Seljeflot, Ingebjørg

2014-01-01

Background and Objectives Elevated levels of matrix metalloproteinase (MMP)-9 have been associated with the metabolic syndrome (MetS) and cardiovascular events. The MMP-9 −1562 C/T polymorphism has furthermore been shown as a risk factor for coronary artery disease (CAD). The non-favourable cardiometabolic state in MetS may increase the risk. We aimed to investigate the influence of MMP-9 −1562 C/T polymorphism in subjects with CAD and MetS. Methods Patients (n = 1000) with verified CAD stratified in Mets +/− (n = 244/756), were analyzed for the MMP-9 −1562 C/T polymorphism and related to clinical events after 2 years follow-up. Serum levels of total MMP-9 and tissue inhibitor of matrix metalloproteinases (TIMP)-1were analyzed in all, whereas MMP-9 activity, extracellular matrix metalloproteinase inducer (EMMPRIN), and expression of the two genes were analyzed in a subset of 240 randomly selected patients. Results Totally, 106 clinical endpoints were recorded. In MetS; the T-allele associated with 5.5 fold increase in event rate (p<0.0001), increased with number of MetS components, a 117% increase in total MMP-9 levels (TT homozygous, p = 0.05), significantly higher total- and endogenous active MMP-9 and TIMP-1 levels (p<0.01 all), and EMMPRIN was inversely correlated with pro- and endogenous active MMP-9 (p<0.05, both). In non-MetS; the T-allele was not associated with new events, nor higher MMP-9 levels. EMMPRIN was significantly correlated with total MMP-9 and TIMP-1 (p<0.01, both) and the two genes were inter-correlated (p<0.001). Conclusion In CAD patients with MetS, the MMP-9 T-allele increased the risk of clinical events, probably mediated through elevated MMP-9 levels and altered MMP-9 regulation. PMID:25191702

The MMP-9 -1562 C/T polymorphism in the presence of metabolic syndrome increases the risk of clinical events in patients with coronary artery disease.

PubMed

Opstad, Trine B; Arnesen, Harald; Pettersen, Alf Å; Seljeflot, Ingebjørg

2014-01-01

Elevated levels of matrix metalloproteinase (MMP)-9 have been associated with the metabolic syndrome (MetS) and cardiovascular events. The MMP-9 -1562 C/T polymorphism has furthermore been shown as a risk factor for coronary artery disease (CAD). The non-favourable cardiometabolic state in MetS may increase the risk. We aimed to investigate the influence of MMP-9 -1562 C/T polymorphism in subjects with CAD and MetS. Patients (n = 1000) with verified CAD stratified in Mets +/- (n = 244/756), were analyzed for the MMP-9 -1562 C/T polymorphism and related to clinical events after 2 years follow-up. Serum levels of total MMP-9 and tissue inhibitor of matrix metalloproteinases (TIMP)-1 were analyzed in all, whereas MMP-9 activity, extracellular matrix metalloproteinase inducer (EMMPRIN), and expression of the two genes were analyzed in a subset of 240 randomly selected patients. Totally, 106 clinical endpoints were recorded. In MetS; the T-allele associated with 5.5 fold increase in event rate (p<0.0001), increased with number of MetS components, a 117% increase in total MMP-9 levels (TT homozygous, p = 0.05), significantly higher total- and endogenous active MMP-9 and TIMP-1 levels (p<0.01 all), and EMMPRIN was inversely correlated with pro- and endogenous active MMP-9 (p<0.05, both). In non-MetS; the T-allele was not associated with new events, nor higher MMP-9 levels. EMMPRIN was significantly correlated with total MMP-9 and TIMP-1 (p<0.01, both) and the two genes were inter-correlated (p<0.001). In CAD patients with MetS, the MMP-9 T-allele increased the risk of clinical events, probably mediated through elevated MMP-9 levels and altered MMP-9 regulation.

Design Structure Matrix (DSM) Methods and Applications for Naval Ship Design

DTIC Science & Technology

2013-05-23

Fax: 817-257-7227 E-mail: t.browninufetcu.edu Web : www. t vsonbrown i ng. com Administrative/Business Contact: Mrs. Teresa Miles Hendrix, MPA...mail: t.browninu(ajtcii.edu Web : www.tvsonbrownina.com Administrative/Business Contact: Mrs. Teresa Miles Hendrix, MPA Assistant Director of...STAKEHOLDER COM ABORDAGEM DE SISTEMAS ADAPTATIVOS A COMPLEXIDADE John Findlay, Ph D. e Abby Straus, M. Div. IMPLEMENTANDO FLEXIBILIDADE

Diagnostics for Intelligent Control of MPD Engines

DTIC Science & Technology

1988-11-15

Comparison of finite and infinite dimensional systems. -29- V r eAtvo which satisfies - ( eAtv ,,) =AeAtvo -Av where eAt is the transition matrix defined by, eA...Bu (6-1) and v(o) =v o where vER’, ueRm, Ae2(Rn,R’), and Bei(Rm,Ra). The solution of this equation at time t is t v(t) = eAtv + f eA(t-S)Bu(s) ds (6-2

Anisotropy of demineralized bone matrix under compressive load.

PubMed

Trębacz, Hanna; Zdunek, Artur

2011-01-01

Two groups of cubic specimens from diaphysis of bovine femur, intact and completely demineralized, were axially compressed. One half of the samples from each group were loaded along the axis of the femur (L) and the other - perpendicularly (T). Intact samples were characterized in terms of elastic modulus; for demineralized samples secant modulus of elasticity was calculated. During compression an acoustic emission (AE) signal was recorded and AE events and energy were analyzed. Samples of intact bone did not reveal any anisotropy under compression at the stress of 80 MPa. However, AE signal indicated an initiation of failure in samples loaded in T direction. Demineralized samples were anisotropic under compression. Both secant modulus of elasticity and AE parameters were significantly higher in T direction than in L direction, which is attributed to shifting and separation of lamellae of collagen fibrils and lamellae in bone matrix.

Tree-level disk amplitude of three closed strings

NASA Astrophysics Data System (ADS)

Mousavi, Sepideh; Velni, Komeil Babaei

2018-05-01

It has been shown that the disk-level S-matrix elements of one Ramond-Ramond (RR) and two Neveu-Schwarz-Neveu-Schwarz (NSNS) states could be found by applying the Ward identity associated with the string duality and the gauge symmetry on a given component of the S matrix. These amplitudes have appeared as the components of six different T-dual multiplets. It is predicted in the literature that there are some nonzero disk-level scattering amplitudes, such as one RR (p -1 ) form with zero transverse index and two N S N S states, could not be captured by the T-dual Ward identity. We explicitly find this amplitude in terms of a minimal context of the integral functions by the insertion of one closed string RR vertex operator and two NSNS vertex operators. From the amplitude invariance under the Ward identity associated with the NSNS gauge transformations and T-duality, we also find some integral identities.

The sensitivity of direct identification from positive BacT/ALERT™ (bioMérieux) blood culture bottles by matrix-assisted laser desorption ionization time-of-flight mass spectrometry is low.

PubMed

Szabados, F; Michels, M; Kaase, M; Gatermann, S

2011-02-01

Recently, matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) has been presented as a novel method for the direct identification of bacteria from positive blood culture bottles. The rate of the MALDI TOF MS-based identification in the present study from positive BacT/ALERT (bioMérieux, Marcy l'Etoile, France) blood culture bottles was 30%, which is far below the previously reported sensitivities using the BACTEC (Becton Dickinson, Franklin Lakes, NJ, USA) system. We also found evidence that the Biotyper algorithm did not identify a second pathogen in cases of positive BacT/ALERT blood culture bottles containing two different species. © 2010 The Authors. Journal Compilation © 2010 European Society of Clinical Microbiology and Infectious Diseases.

Top Quark Mass Measurement in the lepton+jets Channel Using a Matrix Element Method and in situ Jet Energy Calibration

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aaltonen, T.; Brucken, E.; Devoto, F.

A precision measurement of the top quark mass m{sub t} is obtained using a sample of tt events from pp collisions at the Fermilab Tevatron with the CDF II detector. Selected events require an electron or muon, large missing transverse energy, and exactly four high-energy jets, at least one of which is tagged as coming from a b quark. A likelihood is calculated using a matrix element method with quasi-Monte Carlo integration taking into account finite detector resolution and jet mass effects. The event likelihood is a function of m{sub t} and a parameter {Delta}{sub JES} used to calibrate themore » jet energy scale in situ. Using a total of 1087 events in 5.6 fb{sup -1} of integrated luminosity, a value of m{sub t}=173.0{+-}1.2 GeV/c{sup 2} is measured.« less

On the perturbation and subproper splittings for the generalized inverse AT,S(2) of rectangular matrix A

NASA Astrophysics Data System (ADS)

Wei, Yimin; Wu, Hebing

2001-12-01

In this paper, the perturbation and subproper splittings for the generalized inverse AT,S(2), the unique matrix X such that XAX=X, R(X)=T and N(X)=S, are considered. We present lower and upper bounds for the perturbation of AT,S(2). Convergence of subproper splittings for computing the special solution AT,S(2)b of restricted rectangular linear system Ax=b, x[set membership, variant]T, are studied. For the solution AT,S(2)b we develop a characterization. Therefore, we give a unified treatment of the related problems considered in literature by Ben-Israel, Berman, Hanke, Neumann, Plemmons, etc.

Direct Demonstration of the Concept of Unrestricted Effective-Medium Approximation

NASA Technical Reports Server (NTRS)

Mishchenko, Michael I.; Dlugach, Zhanna M.; Zakharova, Nadezhda T.

2014-01-01

The modified unrestricted effective-medium refractive index is defined as one that yields accurate values of a representative set of far-field scattering characteristics (including the scattering matrix) for an object made of randomly heterogeneous materials. We validate the concept of the modified unrestricted effective-medium refractive index by comparing numerically exact superposition T-matrix results for a spherical host randomly filled with a large number of identical small inclusions and Lorenz-Mie results for a homogeneous spherical counterpart. A remarkable quantitative agreement between the superposition T-matrix and Lorenz-Mie scattering matrices over the entire range of scattering angles demonstrates unequivocally that the modified unrestricted effective-medium refractive index is a sound (albeit still phenomenological) concept provided that the size parameter of the inclusions is sufficiently small and their number is sufficiently large. Furthermore, it appears that in cases when the concept of the modified unrestricted effective-medium refractive index works, its actual value is close to that predicted by the Maxwell-Garnett mixing rule.

T-matrix modeling of linear depolarization by morphologically complex soot and soot-containing aerosols

NASA Astrophysics Data System (ADS)

Mishchenko, Michael I.; Liu, Li; Mackowski, Daniel W.

2013-07-01

We use state-of-the-art public-domain Fortran codes based on the T-matrix method to calculate orientation and ensemble averaged scattering matrix elements for a variety of morphologically complex black carbon (BC) and BC-containing aerosol particles, with a special emphasis on the linear depolarization ratio (LDR). We explain theoretically the quasi-Rayleigh LDR peak at side-scattering angles typical of low-density soot fractals and conclude that the measurement of this feature enables one to evaluate the compactness state of BC clusters and trace the evolution of low-density fluffy fractals into densely packed aggregates. We show that small backscattering LDRs measured with ground-based, airborne, and spaceborne lidars for fresh smoke generally agree with the values predicted theoretically for fluffy BC fractals and densely packed near-spheroidal BC aggregates. To reproduce higher lidar LDRs observed for aged smoke, one needs alternative particle models such as shape mixtures of BC spheroids or cylinders.

T-Matrix Modeling of Linear Depolarization by Morphologically Complex Soot and Soot-Containing Aerosols

NASA Technical Reports Server (NTRS)

Mishchenko, Michael I.; Liu, Li; Mackowski, Daniel W.

2013-01-01

We use state-of-the-art public-domain Fortran codes based on the T-matrix method to calculate orientation and ensemble averaged scattering matrix elements for a variety of morphologically complex black carbon (BC) and BC-containing aerosol particles, with a special emphasis on the linear depolarization ratio (LDR). We explain theoretically the quasi-Rayleigh LDR peak at side-scattering angles typical of low-density soot fractals and conclude that the measurement of this feature enables one to evaluate the compactness state of BC clusters and trace the evolution of low-density fluffy fractals into densely packed aggregates. We show that small backscattering LDRs measured with groundbased, airborne, and spaceborne lidars for fresh smoke generally agree with the values predicted theoretically for fluffy BC fractals and densely packed near-spheroidal BC aggregates. To reproduce higher lidar LDRs observed for aged smoke, one needs alternative particle models such as shape mixtures of BC spheroids or cylinders.

Integrated Structural/Control Design via Multiobjective Optimization

DTIC Science & Technology

1990-05-10

motivation is to yield a tractable 0 problem whose solution is readily synthesized and easily implemented. Likewise, the combinatorial approaches to...stations PsI, Ps2, Ps3, Ps4 on arms 3 and 4 and stations Ps5, Ps6, Ps7, Ps8 on arms I and 2. The sensor influence matrix H is 1 oT 0T 0 UoT (psi) T H= 0...t, Ps4 ), v (t,psS) ..... v (t,Ps8) ] T (4-30a) -V = Yp (4-30b) The locations Pul and Pu2 of the torque actuators and Psi, Ps2 .... Ps8 of the sensors

Conjugate-like immunogens produced as protein capsular matrix vaccines.

PubMed

Thanawastien, Ann; Cartee, Robert T; Griffin, Thomas J; Killeen, Kevin P; Mekalanos, John J

2015-03-10

Capsular polysaccharides are the primary antigenic components involved in protective immunity against encapsulated bacterial pathogens. Although immunization of adolescents and adults with polysaccharide antigens has reduced pathogen disease burden, pure polysaccharide vaccines have proved ineffective at conferring protective immunity to infants and the elderly, age cohorts that are deficient in their adaptive immune responses to such antigens. However, T-cell-independent polysaccharide antigens can be converted into more potent immunogens by chemically coupling to a "carrier protein" antigen. Such "conjugate vaccines" efficiently induce antibody avidity maturation, isotype switching, and immunological memory in immunized neonates. These immune responses have been attributed to T-cell recognition of peptides derived from the coupled carrier protein. The covalent attachment of polysaccharide antigens to the carrier protein is thought to be imperative to the immunological properties of conjugate vaccines. Here we provide evidence that covalent attachment to carrier proteins is not required for conversion of T-independent antigens into T-dependent immunogens. Simple entrapment of polysaccharides or a d-amino acid polymer antigen in a cross-linked protein matrix was shown to be sufficient to produce potent immunogens that possess the key characteristics of conventional conjugate vaccines. The versatility and ease of manufacture of these antigen preparations, termed protein capsular matrix vaccines (PCMVs), will likely provide improvements in the manufacture of vaccines designed to protect against encapsulated microorganisms. This in turn could improve the availability of such vaccines to the developing world, which has shown only a limited capacity to afford the cost of conventional conjugate vaccines.

Enabling screening in 3D microenvironments: probing matrix and stromal effects on the morphology and proliferation of T47D breast carcinoma cells.

PubMed

Montanez-Sauri, Sara I; Sung, Kyung Eun; Berthier, Erwin; Beebe, David J

2013-03-01

During breast carcinoma progression, the three-dimensional (3D) microenvironment is continuously remodeled, and changes in the composition of the extracellular matrix (ECM) occur. High throughput screening platforms have been used to decipher the complexity of the microenvironment and to identify ECM components responsible for cancer progression. However, traditional screening platforms are typically limited to two-dimensional (2D) cultures, and often exclude the influence of ECM and stromal components. In this work, a system that integrates 3-dimensional cell culture techniques with an automated microfluidic platform was used to create a new ECM screening platform that cultures cells in more physiologically relevant 3D in vitro microenvironments containing stromal cells and different ECM molecules. This new ECM screening platform was used to culture T47D breast carcinoma cells in mono- and co-culture with human mammary fibroblasts (HMF) with seven combinations of three different ECM proteins (collagen, fibronectin, laminin). Differences in the morphology of T47D clusters, and the proliferation of T47D cells were found in ECM compositions rich in fibronectin or laminin. In addition, an MMP enzyme activity inhibition screening showed the capabilities of the platform for small molecule screening. The platform presented in this work enables screening for the effects of matrix and stromal compositions and show promises for providing new insights in the identification of key ECM components involved in breast cancer.

Molecular t-matrices for Low-Energy Electron Diffraction (TMOL v1.1)

NASA Astrophysics Data System (ADS)

Blanco-Rey, Maria; de Andres, Pedro; Held, Georg; King, David A.

2004-08-01

We describe a FORTRAN-90 program that computes scattering t-matrices for a molecule. These can be used in a Low-Energy Electron Diffraction program to solve the molecular structural problem very efficiently. The intramolecular multiple scattering is computed within a Dyson-like approach, using free space Green propagators in a basis of spherical waves. The advantage of this approach is related to exploiting the chemical identity of the molecule, and to the simplicity to translate and rotate these t-matrices without performing a new multiple-scattering calculation for each configuration. FORTRAN-90 routines for rotating the resulting t-matrices using Wigner matrices are also provided. Program summaryTitle of program: TMOL Catalogue number: ADUF Program summary URL:http://cpc.cs.qub.ac.uk/summaries/ADUF Program obtainable from: CPC Program Library, Queen's University of Belfast, N. Ireland. Computers: Alpha ev6-21264 (700 MHz) and Pentium-IV. Operating systems: Digital UNIX V5.0 and Linux (Red Hat 8.0). Programming language: FORTRAN-90/95 (Compaq True64 compiler, and Intel Fortran Compiler 7.0 for Linux). High-speed storage required for the test run: minimum 64 Mbytes, it can grow to more depending on the system considered. Disk storage required: None. No. of bits in a word: 64 and 32. No. of lines in distributed program, including test data etc.: 5404 No. of bytes in distributed program, including test data etc.: 59 856 Distribution format: tar.gz Nature of problem: We describe the FORTRAN-90 program TMOL (v1.1) for the computation of non-diagonal scattering t-matrices for molecules or any other poly-atomic sub-unit of surface structures. These matrices can be used in an standard Low-Energy Electron Diffraction program, such as LEED90 or CLEED. Method of solution: A general non-diagonal t-matrix is assumed for the atoms or more general scatterers forming the molecule. The molecular t-matrix is solved adding the possible intramolecular multiple scattering events using Green's propagator formalism. The resulting t-matrix is referred to the mass centre of the molecule and can be easily translated with these propagators and rotated applying Wigner matrices. Typical running time: Calculating the t-matrix for a single energy takes a few seconds. Time depends on the maximum angular momentum quantum number, lmax, and the number of scatterers in the molecule, N. Running time scales as lmax6 and N3. References: [1] S. Andersson, J.B. Pendry, J. Phys. C: Solid St. Phys. 13 (1980) 3547. [2] A. Gonis, W.H. Butler, Multiple Scattering in Solids, Springer-Verlag, Berlin/New York, 2000.

Strategies for reducing large fMRI data sets for independent component analysis.

PubMed

Wang, Ze; Wang, Jiongjiong; Calhoun, Vince; Rao, Hengyi; Detre, John A; Childress, Anna R

2006-06-01

In independent component analysis (ICA), principal component analysis (PCA) is generally used to reduce the raw data to a few principal components (PCs) through eigenvector decomposition (EVD) on the data covariance matrix. Although this works for spatial ICA (sICA) on moderately sized fMRI data, it is intractable for temporal ICA (tICA), since typical fMRI data have a high spatial dimension, resulting in an unmanageable data covariance matrix. To solve this problem, two practical data reduction methods are presented in this paper. The first solution is to calculate the PCs of tICA from the PCs of sICA. This approach works well for moderately sized fMRI data; however, it is highly computationally intensive, even intractable, when the number of scans increases. The second solution proposed is to perform PCA decomposition via a cascade recursive least squared (CRLS) network, which provides a uniform data reduction solution for both sICA and tICA. Without the need to calculate the covariance matrix, CRLS extracts PCs directly from the raw data, and the PC extraction can be terminated after computing an arbitrary number of PCs without the need to estimate the whole set of PCs. Moreover, when the whole data set becomes too large to be loaded into the machine memory, CRLS-PCA can save data retrieval time by reading the data once, while the conventional PCA requires numerous data retrieval steps for both covariance matrix calculation and PC extractions. Real fMRI data were used to evaluate the PC extraction precision, computational expense, and memory usage of the presented methods.

Linear Transformation Method for Multinuclide Decay Calculation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ding Yuan

2010-12-29

A linear transformation method for generic multinuclide decay calculations is presented together with its properties and implications. The method takes advantage of the linear form of the decay solution N(t) = F(t)N{sub 0}, where N(t) is a column vector that represents the numbers of atoms of the radioactive nuclides in the decay chain, N{sub 0} is the initial value vector of N(t), and F(t) is a lower triangular matrix whose time-dependent elements are independent of the initial values of the system.

Robust Estimation Based on Walsh Averages for the General Linear Model.

DTIC Science & Technology

1983-11-01

estimate of I minimizing Ip(Z ) has an influence function proportional to p(y) and its asymptotic 2 2-1 variance-covariance matrix is E(* )/(E...in particular, on the influence function h(y) and quantities appearing in the asymptotic vari- ance. Some cno-ents are made on the one- and two...for signed rank estimates. The function P2 (t) of (1.4) has derivative 2(t) = - if t < -c 0 if It < c + I if t > c. *Then the influence function is h(t

A Numerical Combination of Extended Boundary Condition Method and Invariant Imbedding Method Applied to Light Scattering by Large Spheroids and Cylinders

NASA Technical Reports Server (NTRS)

Bi, Lei; Yang, Ping; Kattawar, George W.; Mishchenko, Michael I.

2013-01-01

The extended boundary condition method (EBCM) and invariant imbedding method (IIM) are two fundamentally different T-matrix methods for the solution of light scattering by nonspherical particles. The standard EBCM is very efficient but encounters a loss of precision when the particle size is large, the maximum size being sensitive to the particle aspect ratio. The IIM can be applied to particles in a relatively large size parameter range but requires extensive computational time due to the number of spherical layers in the particle volume discretization. A numerical combination of the EBCM and the IIM (hereafter, the EBCM+IIM) is proposed to overcome the aforementioned disadvantages of each method. Even though the EBCM can fail to obtain the T-matrix of a considered particle, it is valuable for decreasing the computational domain (i.e., the number of spherical layers) of the IIM by providing the initial T-matrix associated with an iterative procedure in the IIM. The EBCM+IIM is demonstrated to be more efficient than the IIM in obtaining the optical properties of large size parameter particles beyond the convergence limit of the EBCM. The numerical performance of the EBCM+IIM is illustrated through representative calculations in spheroidal and cylindrical particle cases.

The association between MMP2 -1306 C > T (rs243865) polymorphism and risk of prostate cancer.

PubMed

Shajarehpoor Salavati, L; Tafvizi, F; Manjili, H K

2017-02-01

Prostate cancer is the second most common cancer in men. Matrix metalloproteinase-2 (MMP2) is the most important member of the matrix metalloproteinase family. MMP2 digests the basement membrane and causes changes in the extracellular matrix which in turn facilitate cancer invasion. It, therefore, has a major role in tumor angiogenesis. Previous studies have identified a single-nucleotide polymorphism C/T at position -1306 of MMP2 gene promoter which is a key regulatory factor in cancer progression. The present study aimed to determine the association between MMP2 polymorphism and the risk of prostate cancer in Iranian men. This case-control study was performed on 50 paraffin-embedded prostate cancer tissue samples and 54 blood samples from healthy men. Genotyping of the samples was performed using high-resolution melting analysis (HRM). Finally, 20 % of the genotypes were confirmed by sequencing. No significant associations were found between CT and TT genotypes and the risk of prostate cancer. However, there were no significant relationships between the genotypes and the studied factors, e.g., age, pathological stage, and Gleason Score. MMP2 -1306 C > T (rs243865) polymorphism was not significantly related with prostate cancer susceptibility in Iranian men.

Investigation of interfacial shear strength in a SiC fibre/Ti-24Al-11Nb composite by a fibre push-out technique

NASA Technical Reports Server (NTRS)

Eldridge, J. I.; Brindley, P. K.

1989-01-01

A fiber push-out technique applied at several sample thicknesses was used to determine both the debond shear stress and the frictional shear stress at the fiber-matrix interface at room temperautre for a unidirectional SiC fiber-reinforced T-24Al-11Nb (in at. pct) composite prepared by a powder cloth technique. The push-out technique measures the separate contributions of bond strength and friction to the mechanical shear strength at the fiber-matrix interface. It was found that the fiber-matrix bond shear strength of this material is significantly higher than the fiber-matrix frictional shear stress (119.2 and 47.8 MPa, respectively).

An Electromagnetically-Controlled Precision Orbital Tracking Vehicle (POTV)

DTIC Science & Technology

1992-12-01

assume that C > B > A. Then 0 1(t) is purely sinusoidal. tk2 (t) is also sinusoidal because the forcing function z(t) is sinusoidal. 03 (t) is more...an unpredictable -manner. The problem arises from the rank deficiency of the G input matrix as shown below. Remember we have shown already that its...rank can never exceed five because rows two, four, and six are linearly dependent. The rank deficiency arises from the "translational part" of the input

Characterization of the CD8{sup +} T cell responses directed against respiratory syncytial virus during primary and secondary infection in C57BL/6 mice

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lukens, Michael V.; Claassen, Erwin A.W.; Graaff, Patricia M.A. de

2006-08-15

The BALB/c mouse model for human respiratory syncytial virus infection has contributed significantly to our understanding of the relative role for CD4{sup +} and CD8{sup +} T cells to immune protection and pathogenic immune responses. To enable comparison of RSV-specific T cell responses in different mouse strains and allow dissection of immune mechanisms by using transgenic and knockout mice that are mostly available on a C57BL/6 background, we characterized the specificity, level and functional capabilities of CD8{sup +} T cells during primary and secondary responses in lung parenchyma, airways and spleens of C57BL/6 mice. During the primary response, epitopes weremore » recognized originating from the matrix, fusion, nucleo- and attachment proteins, whereas the secondary response focused predominantly on the matrix epitope. C57BL/6 mice are less permissive for hRSV infection than BALB/c mice, yet we found CD8{sup +} T cell responses in the lungs and bronchoalveolar lavage, comparable to the responses described for BALB/c mice.« less

Time-resolved diffusion tomographic imaging in highly scattering turbid media

NASA Technical Reports Server (NTRS)

Alfano, Robert R. (Inventor); Cai, Wei (Inventor); Liu, Feng (Inventor); Lax, Melvin (Inventor); Das, Bidyut B. (Inventor)

1998-01-01

A method for imaging objects in highly scattering turbid media. According to one embodiment of the invention, the method involves using a plurality of intersecting source/detectors sets and time-resolving equipment to generate a plurality of time-resolved intensity curves for the diffusive component of light emergent from the medium. For each of the curves, the intensities at a plurality of times are then inputted into the following inverse reconstruction algorithm to form an image of the medium: X.sup.(k+1).spsp.T =?Y.sup.T W+X.sup.(k).spsp.T .LAMBDA.!?W.sup.T W+.LAMBDA.!.sup.-1 wherein W is a matrix relating output at detector position r.sub.d, at time t, to source at position r.sub.s, .LAMBDA. is a regularization matrix, chosen for convenience to be diagonal, but selected in a way related to the ratio of the noise, to fluctuations in the absorption (or diffusion) X.sub.j that we are trying to determine: .LAMBDA..sub.ij =.lambda..sub.j .delta..sub.ij with .lambda..sub.j =/<.DELTA.Xj.DELTA.Xj> Here Y is the data collected at the detectors, and X.sup.k is the kth iterate toward the desired absoption information.

A Trypanosoma cruzi-secreted 80 kDa proteinase with specificity for human collagen types I and IV.

PubMed Central

Santana, J M; Grellier, P; Schrével, J; Teixeira, A R

1997-01-01

Specific interactions between parasites and extracellular matrix components are an important mechanism in the dissemination of Chagas' disease. Binding of the extracellular matrix proteins to Trypanosoma cruzi receptors has been described as a significant step in this phenomenon. In this study, a specific proteinase activity was identified in cell-free extracts of amastigote, trypomastigote and epimastigote forms of T. cruzi using the collagenase fluorogenic substrate N-Suc-Gly-Pro-Leu-Gly-Pro-7-amido-4-methylcoumarin. Isolation of this activity was achieved by a four-step FPLC procedure. Optimal enzyme activity was found to occur at pH 8.0 and was associated with a single T. cruzi 80 kDa protein (Tc 80 proteinase) on SDS/PAGE under reducing conditions. An internal peptide sequence of Tc 80 proteinase was obtained (AGDNYTPPE), and no similarity was found to previously described proteinases of T. cruzi. This enzyme activity is strongly inhibited by HgCl2, tosyl-lysylchloromethane ('TLCK') p-chloromercuribenzoate and benzyloxycarbonyl-Phe-Ala-diazomethane. The purified enzyme was able to hydrolyse purified human [14C]collagen types I and IV at neutral pH, but not 14C-labelled BSA, rat laminin, rabbit IgG or small proteins such as insulin or cytochrome c. In addition, Tc 80 proteinase activity was found to be secreted by T. cruzi forms infective to mammalian cells. Furthermore we demonstrated that purified Tc 80 proteinase mediates native collagen type I hydrolysis in rat mesentery. This feature is compared with that of Clostridium histolyticum collagenase. These findings suggest that Tc 80 proteinase may facilitate T. cruzi host-cell infection by degrading the collagens of the extracellular matrix and could represent a good target for Chagas' disease chemotherapy. PMID:9224638

Oleanolic acid acetate inhibits rheumatoid arthritis by modulating T cell immune responses and matrix-degrading enzymes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Choi, Jin Kyeong; Molecular Immunology Section, Laboratory of Immunology, National Eye Institute, National Institutes of Health, Bethesda, MD 20892; Kim, Sung-Wan

ABSTRACT: Rheumatoid arthritis (RA) is a chronic autoimmune disease associated with a combination of synovium joint inflammation, synovium hyperplasia, and destruction of cartilage and bone. Oleanolic acid acetate (OAA), a compound isolated from Vigna angularis, has been known to possess pharmacological activities, including anti-inflammation and anti-bone destruction. In this study, we investigated the effects of OAA on RA and the underlying mechanisms of action by using a type-II collagen-induced arthritis (CIA) mouse model and tumor necrosis factor (TNF)-α-stimulated RA synovial fibroblasts. Oral administration of OAA decreased the clinical arthritis symptoms, paw thickness, histologic and radiologic changes, and serum total andmore » anti-type II collagen IgG, IgG1, and IgG2a levels. OAA administration reduced Th1/Th17 phenotype CD4{sup +} T lymphocyte expansions and inflammatory cytokine productions in T cell activated draining lymph nodes and spleen. OAA reduced the expression and production of inflammatory mediators, such as cytokines and matrix metalloproteinase (MMP)-1/3, in the ankle joint tissue and RA synovial fibroblasts by down-regulating Akt, mitogen-activated protein kinases, and nuclear factor-κB. Our results clearly support that OAA plays a therapeutic role in RA pathogenesis by modulating helper T cell immune responses and matrix-degrading enzymes. The immunosuppressive effects of OAA were comparable to dexamethasone and ketoprofen. We provide evidences that OAA could be a potential therapeutic candidate for RA. - Highlights: • OAA attenuated chronic CIA symptoms. • OAA had a regulating effect on the T helper cell immune reaction for CIA. • The effect of OAA on the RA was comparable to the dexamethasone or ketoprofen. • OAA might be a candidate for the treatment of arthritic diseases.« less

Methods, Tools, and Data for Coastal System Resilience Assessments

DTIC Science & Technology

2015-10-06

Baseline Resilience Indicators for Communities ( BRIC ) BUILDING STRONG® Innovative solutions for a safer, better world ► T: SoVI® – Social...address policy  Objective, although data may be arbitrarily weighted in an index Examples: Top-Down (T) and Bottom-Up (B) Bottom-UpTop-Down BRIC ...Coastal Resilience Index USACE’s Resilience Matrix ASCE’s Infrastructure Report Card T: Baseline Resilience Index for Communities ( BRIC

Thyroid Hormone Induces Apoptosis in Primary Cell Cultures of Tadpole Intestine: Cell Type Specificity and Effects of Extracellular Matrix

PubMed Central

Su, Yuan; Shi, Yufang; Stolow, Melissa A.; Shi, Yun-Bo

1997-01-01

Thyroid hormone (T3 or 3,5,3′-triiodothyronine) plays a causative role during amphibian metamorphosis. To investigate how T3 induces some cells to die and others to proliferate and differentiate during this process, we have chosen the model system of intestinal remodeling, which involves apoptotic degeneration of larval epithelial cells and proliferation and differentiation of other cells, such as the fibroblasts and adult epithelial cells, to form the adult intestine. We have established in vitro culture conditions for intestinal epithelial cells and fibroblasts. With this system, we show that T3 can enhance the proliferation of both cell types. However, T3 also concurrently induces larval epithelial apoptosis, which can be inhibited by the extracellular matrix (ECM). Our studies with known inhibitors of mammalian cell death reveal both similarities and differences between amphibian and mammalian cell death. These, together with gene expression analysis, reveal that T3 appears to simultaneously induce different pathways that lead to specific gene regulation, proliferation, and apoptotic degeneration of the epithelial cells. Thus, our data provide an important molecular and cellular basis for the differential responses of different cell types to the endogenous T3 during metamorphosis and support a role of ECM during frog metamorphosis. PMID:9396758

Radiative-Transfer Modeling of Spectra of Densely Packed Particulate Media

NASA Astrophysics Data System (ADS)

Ito, G.; Mishchenko, M. I.; Glotch, T. D.

2017-12-01

Remote sensing measurements over a wide range of wavelengths from both ground- and space-based platforms have provided a wealth of data regarding the surfaces and atmospheres of various solar system bodies. With proper interpretations, important properties, such as composition and particle size, can be inferred. However, proper interpretation of such datasets can often be difficult, especially for densely packed particulate media with particle sizes on the order of wavelength of light being used for remote sensing. Radiative transfer theory has often been applied to the study of densely packed particulate media like planetary regoliths and snow, but with difficulty, and here we continue to investigate radiative transfer modeling of spectra of densely packed media. We use the superposition T-matrix method to compute scattering properties of clusters of particles and capture the near-field effects important for dense packing. Then, the scattering parameters from the T-matrix computations are modified with the static structure factor correction, accounting for the dense packing of the clusters themselves. Using these corrected scattering parameters, reflectance (or emissivity via Kirchhoff's Law) is computed with the method of invariance imbedding solution to the radiative transfer equation. For this work we modeled the emissivity spectrum of the 3.3 µm particle size fraction of enstatite, representing some common mineralogical and particle size components of regoliths, in the mid-infrared wavelengths (5 - 50 µm). The modeled spectrum from the T-matrix method with static structure factor correction using moderate packing densities (filling factors of 0.1 - 0.2) produced better fits to the laboratory measurement of corresponding spectrum than the spectrum modeled by the equivalent method without static structure factor correction. Future work will test the method of the superposition T-matrix and static structure factor correction combination for larger particles sizes and polydispersed clusters in search for the most effective modeling of spectra of densely packed particulate media.

Lagrange constraint neural network for audio varying BSS

NASA Astrophysics Data System (ADS)

Szu, Harold H.; Hsu, Charles C.

2002-03-01

Lagrange Constraint Neural Network (LCNN) is a statistical-mechanical ab-initio model without assuming the artificial neural network (ANN) model at all but derived it from the first principle of Hamilton and Lagrange Methodology: H(S,A)= f(S)- (lambda) C(s,A(x,t)) that incorporates measurement constraint C(S,A(x,t))= (lambda) ([A]S-X)+((lambda) 0-1)((Sigma) isi -1) using the vector Lagrange multiplier-(lambda) and a- priori Shannon Entropy f(S) = -(Sigma) i si log si as the Contrast function of unknown number of independent sources si. Szu et al. have first solved in 1997 the general Blind Source Separation (BSS) problem for spatial-temporal varying mixing matrix for the real world remote sensing where a large pixel footprint implies the mixing matrix [A(x,t)] necessarily fill with diurnal and seasonal variations. Because the ground truth is difficult to be ascertained in the remote sensing, we have thus illustrated in this paper, each step of the LCNN algorithm for the simulated spatial-temporal varying BSS in speech, music audio mixing. We review and compare LCNN with other popular a-posteriori Maximum Entropy methodologies defined by ANN weight matrix-[W] sigmoid-(sigma) post processing H(Y=(sigma) ([W]X)) by Bell-Sejnowski, Amari and Oja (BSAO) called Independent Component Analysis (ICA). Both are mirror symmetric of the MaxEnt methodologies and work for a constant unknown mixing matrix [A], but the major difference is whether the ensemble average is taken at neighborhood pixel data X's in BASO or at the a priori sources S variables in LCNN that dictates which method works for spatial-temporal varying [A(x,t)] that would not allow the neighborhood pixel average. We expected the success of sharper de-mixing by the LCNN method in terms of a controlled ground truth experiment in the simulation of variant mixture of two music of similar Kurtosis (15 seconds composed of Saint-Saens Swan and Rachmaninov cello concerto).

Insight on agglomerates of gold nanoparticles in glass based on surface plasmon resonance spectrum: study by multi-spheres T-matrix method

NASA Astrophysics Data System (ADS)

Avakyan, L. A.; Heinz, M.; Skidanenko, A. V.; Yablunovski, K. A.; Ihlemann, J.; Meinertz, J.; Patzig, C.; Dubiel, M.; Bugaev, L. A.

2018-01-01

The formation of a localized surface plasmon resonance (SPR) spectrum of randomly distributed gold nanoparticles in the surface layer of silicate float glass, generated and implanted by UV ArF-excimer laser irradiation of a thin gold layer sputter-coated on the glass surface, was studied by the T-matrix method, which enables particle agglomeration to be taken into account. The experimental technique used is promising for the production of submicron patterns of plasmonic nanoparticles (given by laser masks or gratings) without damage to the glass surface. Analysis of the applicability of the multi-spheres T-matrix (MSTM) method to the studied material was performed through calculations of SPR characteristics for differently arranged and structured gold nanoparticles (gold nanoparticles in solution, particles pairs, and core-shell silver-gold nanoparticles) for which either experimental data or results of the modeling by other methods are available. For the studied gold nanoparticles in glass, it was revealed that the theoretical description of their SPR spectrum requires consideration of the plasmon coupling between particles, which can be done effectively by MSTM calculations. The obtained statistical distributions over particle sizes and over interparticle distances demonstrated the saturation behavior with respect to the number of particles under consideration, which enabled us to determine the effective aggregate of particles, sufficient to form the SPR spectrum. The suggested technique for the fitting of an experimental SPR spectrum of gold nanoparticles in glass by varying the geometrical parameters of the particles aggregate in the recurring calculations of spectrum by MSTM method enabled us to determine statistical characteristics of the aggregate: the average distance between particles, average size, and size distribution of the particles. The fitting strategy of the SPR spectrum presented here can be applied to nanoparticles of any nature and in various substances, and, in principle, can be extended for particles with non-spherical shapes, like ellipsoids, rod-like and other T-matrix-solvable shapes.

Characterization of Anisotropic Behavior for High Grade Pipes

NASA Astrophysics Data System (ADS)

Yang, Kun; Huo, Chunyong; Ji, Lingkang; Li, Yang; Zhang, Jiming; Ma, Qiurong

With the developing requirement of nature gas, the property needs of steel for pipe line are higher and higher, especially in strength and toughness. It is necessary to improve the steel grade in order to ensure economic demand and safety. However, with the rise of steel grade, the differences on properties in different orientations (anisotropic behaviors) become more and more obvious after the process of hot rolling, which may affect the prediction of fracture for the pipes seriously (Thinking of isotropic mechanical properties for material in traditional predict way). In order to get the reason for anisotropic mechanics, a series of tests are carried out for high grade steel pipes, including not only mechanical properties but also microstructures. Result indicates that there are obviously anisotropic behaviors for high grade steel pipes in two orientations (rolling orientation and transverse orientation). Strength is better in T orientation because Rm is higher and Rt 0.5 rises more in T orientation, and toughness is better in L orientation because of the higher Akv and SA in L orientation under a same temperature. Banded structures are formed in T orientation, and the spatial distribution of inclusion and precipitated phases are different in T, L and S orientation. The anisotropic arrangement for the matrix in space (banded structures), which is formed after the process of hot rolling, may affect the mechanical properties in different orientation. Moreover, the elasticity modulus of particles is different from the elasticity modulus of matrix, deformation between particles and matrix may cause stress concentration, and damage forms in this place. Because of the different distribution of particles in space, the level of damage is anisotropic in different orientations, and the anisotropic mechanical properties occur finally. Therefore, the anisotropic mechanical properties are determined by the anisotropic microstructures, both the anisotropic of matrix and the anisotropic of particles are included.

Recent progresses of neural network unsupervised learning: I. Independent component analyses generalizing PCA

NASA Astrophysics Data System (ADS)

Szu, Harold H.

1999-03-01

The early vision principle of redundancy reduction of 108 sensor excitations is understandable from computer vision viewpoint toward sparse edge maps. It is only recently derived using a truly unsupervised learning paradigm of artificial neural networks (ANN). In fact, the biological vision, Hubel- Wiesel edge maps, is reproduced seeking the underlying independent components analyses (ICA) among 102 image samples by maximizing the ANN output entropy (partial)H(V)/(partial)[W] equals (partial)[W]/(partial)t. When a pair of newborn eyes or ears meet the bustling and hustling world without supervision, they seek ICA by comparing 2 sensory measurements (x1(t), x2(t))T equalsV X(t). Assuming a linear and instantaneous mixture model of the external world X(t) equals [A] S(t), where both the mixing matrix ([A] equalsV [a1, a2] of ICA vectors and the source percentages (s1(t), s2(t))T equalsV S(t) are unknown, we seek the independent sources approximately equals [I] where the approximated sign indicates that higher order statistics (HOS) may not be trivial. Without a teacher, the ANN weight matrix [W] equalsV [w1, w2] adjusts the outputs V(t) equals tanh([W]X(t)) approximately equals [W]X(t) until no desired outputs except the (Gaussian) 'garbage' (neither YES '1' nor NO '-1' but at linear may-be range 'origin 0') defined by Gaussian covariance G equals [I] equals [W][A] at the fixed point (partial)E/(partial)wi equals 0 resulted in an exact Toplitz matrix inversion for a stationary covariance assumption. We generalize AR by a nonlinear output vi(t+1) equals tanh(wiTX(t)) within E equals <[x(t+1) - vi(t+1)]2>, and the gradient descent (partial)E/(partial)wi equals - (partial)wi/(partial)t. Further generalization is possible because of specific image/speech having a specific histogram whose gray scale statistics departs from that of Gaussian random variable and can be measured by the fourth order cumulant, Kurtosis K(vi) equals - 3 2 (K greater than or equal to 0 super-G for speeches, K less than or equal to 0 sub-G for images). Thus, the stationary value at (partial)K/(partial)wi equals plus or minus 4 PTLwi/(partial)t can de-mix unknown mixtures of noisy images/speeches without a teacher. This stationary statistics may be parallel implemented using the 'factorized pdf code: (rho) (v1, v2) equals (rho) (v1) (rho) (v2)' occurred at a maximal entropy algorithm improved by the natural gradient of Amari. Real world applications are given in Part II, (Wavelet Appl-VI, SPIE Proc. Vol. 3723) such as remote sensing subpixel composition, speech segmentation by means of ICA de-hyphenation, and cable TV bandwidth enhancement by simultaneously mixing sport and movie entertainment events.

Random Matrix Theory and Econophysics

NASA Astrophysics Data System (ADS)

Rosenow, Bernd

2000-03-01

Random Matrix Theory (RMT) [1] is used in many branches of physics as a ``zero information hypothesis''. It describes generic behavior of different classes of systems, while deviations from its universal predictions allow to identify system specific properties. We use methods of RMT to analyze the cross-correlation matrix C of stock price changes [2] of the largest 1000 US companies. In addition to its scientific interest, the study of correlations between the returns of different stocks is also of practical relevance in quantifying the risk of a given stock portfolio. We find [3,4] that the statistics of most of the eigenvalues of the spectrum of C agree with the predictions of RMT, while there are deviations for some of the largest eigenvalues. We interpret these deviations as a system specific property, e.g. containing genuine information about correlations in the stock market. We demonstrate that C shares universal properties with the Gaussian orthogonal ensemble of random matrices. Furthermore, we analyze the eigenvectors of C through their inverse participation ratio and find eigenvectors with large ratios at both edges of the eigenvalue spectrum - a situation reminiscent of localization theory results. This work was done in collaboration with V. Plerou, P. Gopikrishnan, T. Guhr, L.A.N. Amaral, and H.E Stanley and is related to recent work of Laloux et al.. 1. T. Guhr, A. Müller Groeling, and H.A. Weidenmüller, ``Random Matrix Theories in Quantum Physics: Common Concepts'', Phys. Rep. 299, 190 (1998). 2. See, e.g. R.N. Mantegna and H.E. Stanley, Econophysics: Correlations and Complexity in Finance (Cambridge University Press, Cambridge, England, 1999). 3. V. Plerou, P. Gopikrishnan, B. Rosenow, L.A.N. Amaral, and H.E. Stanley, ``Universal and Nonuniversal Properties of Cross Correlations in Financial Time Series'', Phys. Rev. Lett. 83, 1471 (1999). 4. V. Plerou, P. Gopikrishnan, T. Guhr, B. Rosenow, L.A.N. Amaral, and H.E. Stanley, ``Random Matrix Theory Analysis of Diffusion in Stock Price Dynamics, preprint

Modulation of cardiac myocyte phenotype in vitro by the composition and orientation of the extracellular matrix.

PubMed

Simpson, D G; Terracio, L; Terracio, M; Price, R L; Turner, D C; Borg, T K

1994-10-01

Cellular phenotype is the result of a dynamic interaction between a cell's intrinsic genetic program and the morphogenetic signals that serve to modulate the extent to which that program is expressed. In the present study we have examined how morphogenetic information might be stored in the extracellular matrix (ECM) and communicated to the neonatal heart cell (NHC) by the cardiac alpha 1 beta 1 integrin molecule. A thin film of type I collagen (T1C) was prepared with a defined orientation. This was achieved by applying T1C to the peripheral edge of a 100 mm culture dish. The T1C was then drawn across the surface of the dish in a continuous stroke with a sterile cell scraper and allowed to polymerize. When NHCs were cultured on this substrate, they spread, as a population, along a common axis in parallel with the gel lattice and expressed an in vivo-like phenotype. Individual NHCs displayed an elongated, rod-like shape and disclosed parallel arrays of myofibrils. These phenotypic characteristics were maintained for at least 4 weeks in primary culture. The evolution of this tissue-like organizational pattern was dependent upon specific interactions between the NHCs and the collagen-based matrix that were mediated by the cardiac alpha 1 beta 1 integrin complex. This conclusion was supported by a variety of experimental results. Altering the tertiary structure of the matrix or blocking the extracellular domains of either the cardiac alpha 1 or beta 1 integrin chain inhibited the expression of the tissue-like pattern of organization. Neither cell-to-cell contact or contractile function were necessary to induce the formation of the rod-like cell shape. However, beating activity was necessary for the assembly of a well-differentiated myofibrillar apparatus. These data suggest that the cardiac alpha 1 beta 1 integrin complex serves to detect and transduce phenotypic information stored within the tertiary structure of the surrounding matrix.

T-matrix Study of Scattering and Absorption of Light by Biomass Burning Aerosols

NASA Astrophysics Data System (ADS)

Poudel, Samin

The uncertainty in the measurements of aerosol optical properties has made it difficult to quantify the global impact of aerosols on Earth's climate and limits our ability to predict future climate changes. Morphology, size, volume, shape, fuel type, burning conditions, aging, and changes in chemical composition due to atmospheric processing of soot play a significant part in determining the optical properties of aerosols. The T-matrix method has been successfully used to reproduce experimental results of optical properties of spherical and non-spherical particles. In this work we applied the T-matrix method to extract the refractive index of biomass burning soot (burning pine tree) by reproducing experimentally determined single scattering albedo (SSA), scattering and extinction cross section values obtained by burning pine and collecting aerosols in two different ways: (1) from an outdoor burn drum to burn pine and collect soot in distilled water using an impinger and re-aerosolized the soot after several days to measure extinction and scattering cross sections using cavity ring down spectroscopy and nephelometry and (2) from a tube furnace in the lab to burn pine and the soot was introduced into an indoor smog chamber and soot particles sampled directly into the cavity ring down system and the nephelometer to measure extinction and scattering cross sections. Filter samples were also collected from both types of burning and electron microscopy images were used to obtain morphology and size information to conduct T-Matrix calculations. The experimentally measured optical properties from the impinger samples were reproduced using a refractive index of 1.345 + i0.096 for 300 and 400nm particles, while the results from the tube furnace samples were reproduced using 1.88 + i0.024 for 200 nm particles and 1.47 + i0.047 for 300 nm particles. This suggests that the impinger samples do not represent fresh soot since they are more absorbing and have lower SSA values compared to ours and other similar laboratory and field measurements for fresh soot. Morphology information from images of filter samples was used in the T-matrix calculation using refractive index of 1.88 + i0.024 to reproduce the SSA values for the fresh soot. It is shown that refractive indices used for fresh diesel soot or soot produced from propane 1.76 + i0.57 cannot be applied to biomass burning soot, as it provides a significantly lower SSA values in both cases.

Phase diagram of matrix compressed sensing

NASA Astrophysics Data System (ADS)

Schülke, Christophe; Schniter, Philip; Zdeborová, Lenka

2016-12-01

In the problem of matrix compressed sensing, we aim to recover a low-rank matrix from a few noisy linear measurements. In this contribution, we analyze the asymptotic performance of a Bayes-optimal inference procedure for a model where the matrix to be recovered is a product of random matrices. The results that we obtain using the replica method describe the state evolution of the Parametric Bilinear Generalized Approximate Message Passing (P-BiG-AMP) algorithm, recently introduced in J. T. Parker and P. Schniter [IEEE J. Select. Top. Signal Process. 10, 795 (2016), 10.1109/JSTSP.2016.2539123]. We show the existence of two different types of phase transition and their implications for the solvability of the problem, and we compare the results of our theoretical analysis to the numerical performance reached by P-BiG-AMP. Remarkably, the asymptotic replica equations for matrix compressed sensing are the same as those for a related but formally different problem of matrix factorization.

Matrix-free mass spectrometric imaging using laser desorption ionisation Fourier transform ion cyclotron resonance mass spectrometry.

PubMed

Goodwin, Richard J A; Pitt, Andrew R; Harrison, David; Weidt, Stefan K; Langridge-Smith, Pat R R; Barrett, Michael P; Logan Mackay, C

2011-04-15

Mass spectrometry imaging (MSI) is a powerful tool in metabolomics and proteomics for the spatial localization and identification of pharmaceuticals, metabolites, lipids, peptides and proteins in biological tissues. However, sample preparation remains a crucial variable in obtaining the most accurate distributions. Common washing steps used to remove salts, and solvent-based matrix application, allow analyte spreading to occur. Solvent-free matrix applications can reduce this risk, but increase the possibility of ionisation bias due to matrix adhesion to tissue sections. We report here the use of matrix-free MSI using laser desorption ionisation performed on a 12 T Fourier transform ion cyclotron resonance (FTICR) mass spectrometer. We used unprocessed tissue with no post-processing following thaw-mounting on matrix-assisted laser desorption ionisation (MALDI) indium-tin oxide (ITO) target plates. The identification and distribution of a range of phospholipids in mouse brain and kidney sections are presented and compared with previously published MALDI time-of-flight (TOF) MSI distributions. Copyright © 2011 John Wiley & Sons, Ltd.

Matrix Effects and Interferences of Different Citrus Fruit Coextractives in Pesticide Residue Analysis Using Ultrahigh-Performance Liquid Chromatography-High-Resolution Mass Spectrometry.

PubMed

Besil, Natalia; Cesio, Verónica; Heinzen, Horacio; Fernandez-Alba, Amadeo R

2017-06-14

The matrix effects of ethyl acetate extracts from seven different citrus fruits on the determination of 80 pesticide residues using liquid chromatography coupled to high-resolution time-of-flight mass spectrometry (UHPLC-(ESI)-HR-TOF) at 4 GHz resolution mode were studied. Only 20% of the evaluated pesticides showed noticeable matrix effects (ME) due to coelution with natural products between t R = 3 and 11 min. Principal component analysis (PCA) of the detected coextractives grouped the mandarins and the orange varieties, but separated lemon, oranges, and mandarins from each other. Matrix effects were different among species but similar between varieties, forcing the determination of pesticide residues through matrix-matched calibration curves with the same fruit. Twenty-three natural products (synephrine, naringin, poncirin, glycosides of hesperitin, limonin, nomilin, and a few fatty acids, among others) were identified in the analyzed extracts. Twelve of the identified compounds coeluted with 28 of the pesticides under study, causing different matrix effects.

Fundamental Studies of Low Velocity Impact Resistance of Graphite Fiber Reinforced Polymer Matrix Composites. Ph.D. Thesis

NASA Technical Reports Server (NTRS)

Bowles, K. J.

1985-01-01

A study was conducted to relate the impact resistance of graphite fiber reinforced composites with matrix properties through gaining an understanding of the basic mechanics involved in the deformation and fracture process, and the effect of the polymer matrix structure on these mechanisms. It was found that the resin matrix structure influences the composite impact resistance in at least two ways. The integration of flexibilizers into the polymer chain structure tends to reduce the T sub g and the mechanical properties of the polymer. The reduction in the mechanical properties of the matrix does not enhance the composite impact resistance because it allows matrix controlled failure to initiate impact damage. It was found that when the instrumented dropweight impact tester is used as a means for assessing resin toughness, the resin toughness is enhanced by the ability of the clamped specimen to deflect enough to produce sufficient membrane action to support a significant amount of the load. The results of this study indicate that crossplied composite impact resistance is very much dependent on the matrix mechanical properties.

Matrix metalloproteinase-9 functional promoter polymorphism 1562C>T increased risk of early-onset coronary artery disease.

PubMed

Saedi, Massoud; Vaisi-Raygani, Asad; Khaghani, Shahnaz; Shariftabrizi, Ahmad; Rezaie, M; Pasalar, Parvin; Rahimi, Zohreh; Pourmotabbed, Tayebeh

2012-01-01

The Matrix metalloproteinase-9 functional promoter polymorphism 1562C>T may be considered an important genetic determinant of early-onset coronary artery disease (ECAD). In this study, association between MMP-9 1562C>T allele with plasma MMP-9 activity, homocysteine and lipid-lipoproteins level and ECAD in Iranian subjects was investigated. This case-control study consisted of 53 ECAD patients (age < 55 years) and unrelated late-onsets CAD (age>70 years) who angiographically had at least 50% stenosis. MMP-9 1562C>T polymorphism was detected by PCRRFLP, plasma MMP-9 activity, serum lipid and homocysteine levels were determined by gelatin gel zymography, enzyme assay and by HPLC, respectively. The presence of MMP-9 1562C>T allele was found to be associated with ECAD (OR=3.2, P=0.001). The ECAD patients with MMP-9 1562C>T allele had higher MMP-9 activity (P=0.001), LDL-C (P=0.045), TC (P=0.02) and homocysteine (P=0.01) levels than the LCAD subjects. MMP-9 1562C>T allele is a risk factor for ECAD. The carriers of this allele have high levels of MMP-9 activity, LDL-C, TC and homocysteine (P=0.01), thus, are more likely to develop myocardial infarction and CAD at young age (less than 55 years).

Influence of electron radiation and temperature on the cyclic, matrix dominated response of graphite-epoxy

NASA Technical Reports Server (NTRS)

Reed, Susan M.; Herakovich, Carl T.; Sykes, George F., Jr.

1987-01-01

The effects of electron radiation and elevated temperature on the matrix-dominated cyclic response of standard T300/934 and a chemically modified T300/934 graphite-epoxy are characterized. Both materials were subjected to 1.0 x 10 to the 10th rads of 1.0 MeV electron irradiation, under vacuum, to simulate 30 years in geosynchronous orbit. Cyclic tests were performed at room temperature and elevated temperature (121 C) on 4-ply unidirectional laminates to characterize the effects associated with irradiation and elevated temperature. Both materials exhibited energy dissipation in their response at elevated temperature. The irradiated modified material also exhibited energy dissipation at room temperature. The combination of elevated temperature and irradiation resulted in the most severe effects in the form of lower proportional limits, and greater energy dissipation. Dynamic-mechanical analysis demonstrated that the glass transition temperature, T(g), of the standard material was lowered 39 C by irradiation, wereas the T(g) of the modified material was lowered 28 C by irradiation. Thermomechanical analysis showed the occurrence of volatile products generated upon heating of the irradiated materials.

Multifilament Superconducting Wire Based on NbTi Alloy in a Combined Copper/Copper-Nickel Matrix

NASA Astrophysics Data System (ADS)

Vedernikov, G. P.; Shikov, A. K.; Potanina, L. V.; Gubkin, I. N.; Scherbakova, O. V.; Salunin, N. I.; Korpusov, V. U.; Novikov, S. I.; Novikov, M. S.

2004-06-01

Model fine filament superconducting 0.65 mm wire based on NbTi alloy, intended for operating in fields having sweep rate from 1 up to 4 T/s, has been developed and manufactured by Bochvar Institute (VNIINM). The wire was fabricated by a single stacking method. Each filament was surrounded by a matrix of commercial MN-5 alloy (Cu-5wt.%Ni). The effects of heat treatment regimes, and twist pitches within the range of 3.5 - 8 mm on Jc of the strand were investigated at fields of 2-8 T. The critical current density is more than 2700 A/mm2 at 5 T, 4.2 K. The magnetization of wire has been measured by a vibrating magnetometer at field amplitude up to ± 3 T. Hysteresis losses and effective diameter were calculated. Total and coupling losses have been determined by Fitz method on strand magnetization at fields, varying in trapezoidal mode. It was shown that the wire of this type is of potential application for the use in the magnets of the GSI-type accelerator to be constructed in Germany.

k-t Acceleration in pure phase encode MRI to monitor dynamic flooding processes in rock core plugs

NASA Astrophysics Data System (ADS)

Xiao, Dan; Balcom, Bruce J.

2014-06-01

Monitoring the pore system in sedimentary rocks with MRI when fluids are introduced is very important in the study of petroleum reservoirs and enhanced oil recovery. However, the lengthy acquisition time of each image, with pure phase encode MRI, limits the temporal resolution. Spatiotemporal correlations can be exploited to undersample the k-t space data. The stacked frames/profiles can be well approximated by an image matrix with rank deficiency, which can be recovered by nonlinear nuclear norm minimization. Sparsity of the x-t image can also be exploited for nonlinear reconstruction. In this work the results of a low rank matrix completion technique were compared with k-t sparse compressed sensing. These methods are demonstrated with one dimensional SPRITE imaging of a Bentheimer rock core plug and SESPI imaging of a Berea rock core plug, but can be easily extended to higher dimensionality and/or other pure phase encode measurements. These ideas will enable higher dimensionality pure phase encode MRI studies of dynamic flooding processes in low magnetic field systems.

Collagen-derived dipeptide prolyl-hydroxyproline promotes differentiation of MC3T3-E1 osteoblastic cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kimira, Yoshifumi, E-mail: kimira@josai.ac.jp; Ogura, Kana; Taniuchi, Yuri

Highlights: • Pro-Hyp did not affect MC3T3-E1 cell proliferation and matrix mineralization. • Pro-Hyp significantly increased alkaline phosphatase activity. • Pro-Hyp significantly upregulated gene expression of Runx2, Osterix, and Col1α1. - Abstract: Prolyl-hydroxyproline (Pro-Hyp) is one of the major constituents of collagen-derived dipeptides. The objective of this study was to investigate the effects of Pro-Hyp on the proliferation and differentiation of MC3T3-E1 osteoblastic cells. Addition of Pro-Hyp did not affect MC3T3-E1 cell proliferation and matrix mineralization but alkaline phosphatase activity was significantly increased. Furthermore, cells treated with Pro-Hyp significantly upregulated gene expression of Runx2, Osterix, and Col1α1. These results indicatemore » that Pro-Hyp promotes osteoblast differentiation. This study demonstrates for the first time that Pro-Hyp has a positive effect on osteoblast differentiation with upregulation of Runx2, Osterix, and Collα1 gene expression.« less

Pharmacologic inhibition of the enzymatic effects of tissue transglutaminase reduces cardiac fibrosis and attenuates cardiomyocyte hypertrophy following pressure overload.

PubMed

Shinde, Arti V; Su, Ya; Palanski, Brad A; Fujikura, Kana; Garcia, Mario J; Frangogiannis, Nikolaos G

2018-04-01

Tissue transglutaminase (tTG) is a multifunctional protein with a wide range of enzymatic and non-enzymatic functions. We have recently demonstrated that tTG expression is upregulated in the pressure-overloaded myocardium and exerts fibrogenic actions promoting diastolic dysfunction, while preventing chamber dilation. Our current investigation dissects the in vivo and in vitro roles of the enzymatic effects of tTG on fibrotic remodeling in pressure-overloaded myocardium. Using a mouse model of transverse aortic constriction, we demonstrated perivascular and interstitial tTG activation in the remodeling pressure-overloaded heart. tTG inhibition through administration of the selective small molecule tTG inhibitor ERW1041E attenuated left ventricular diastolic dysfunction and reduced cardiomyocyte hypertrophy and interstitial fibrosis in the pressure-overloaded heart, without affecting chamber dimensions and ejection fraction. In vivo, tTG inhibition markedly reduced myocardial collagen mRNA and protein levels and attenuated transcription of fibrosis-associated genes. In contrast, addition of exogenous recombinant tTG to fibroblast-populated collagen pads had no significant effects on collagen transcription, and instead increased synthesis of matrix metalloproteinase (MMP)3 and tissue inhibitor of metalloproteinases (TIMP)1 through transamidase-independent actions. However, enzymatic effects of matrix-bound tTG increased the thickness of pericellular collagen in fibroblast-populated pads. tTG exerts distinct enzymatic and non-enzymatic functions in the remodeling pressure-overloaded heart. The enzymatic effects of tTG are fibrogenic and promote diastolic dysfunction, but do not directly modulate the pro-fibrotic transcriptional program of fibroblasts. Targeting transamidase-dependent actions of tTG may be a promising therapeutic strategy in patients with heart failure and fibrosis-associated diastolic dysfunction. Copyright © 2018 Elsevier Ltd. All rights reserved.

Delayed-type hypersensitivity lesions in the central nervous system are prevented by inhibitors of matrix metalloproteinases.

PubMed

Matyszak, M K; Perry, V H

1996-09-01

We have studied the effect of an inhibitor of matrix metalloproleinases, BB-1101, on a delayed-type hypersensitivity (DTH) response in the CNS. We used a recently described model in which heat-killed bacillus Calmette-Guérin (BCG) sequestered behind the blood-brain barrier (BBB) is targeted by a T-cell mediated response after subcutaneous injection of BCG (Matyszak and Perry, 1995). The DTH lesions are characterised by breakdown of the BBB, macrophage and lymphocyte infiltration and tissue damage including myelin loss. Treatment with BB-1101, which is not only a potent inhibitor of matrix metalloproteinases but also strongly inhibits TNF-alpha release, dramatically attenuated the CNS lesions. Breakdown of the BBB and the recruitment of T-cells into the site of the lesion were significantly reduced. There were many fewer inflammatory macrophages in DTH lesions than in comparable lesions from untreated animals. There was also significantly less myelin damage (assessed by staining with anti-MBP antibody). The DTH response in animals treated with dexamethasone was also reduced, but to a lesser degree. No significant effect was seen after administration of pentoxifylline, a phosphodiesterase inhibitor with effects including the inhibition of TNF-alpha production. Our results suggest that inhibitors of matrix metalloproteinases may be of considerable therapeutic benefit in neuroinflammatory diseases.

Deghosting based on the transmission matrix method

NASA Astrophysics Data System (ADS)

Wang, Benfeng; Wu, Ru-Shan; Chen, Xiaohong

2017-12-01

As the developments of seismic exploration and subsequent seismic exploitation advance, marine acquisition systems with towed streamers become an important seismic data acquisition method. But the existing air-water reflective interface can generate surface related multiples, including ghosts, which can affect the accuracy and performance of the following seismic data processing algorithms. Thus, we derive a deghosting method from a new perspective, i.e. using the transmission matrix (T-matrix) method instead of inverse scattering series. The T-matrix-based deghosting algorithm includes all scattering effects and is convergent absolutely. Initially, the effectiveness of the proposed method is demonstrated using synthetic data obtained from a designed layered model, and its noise-resistant property is also illustrated using noisy synthetic data contaminated by random noise. Numerical examples on complicated data from the open SMAART Pluto model and field marine data further demonstrate the validity and flexibility of the proposed method. After deghosting, low frequency components are recovered reasonably and the fake high frequency components are attenuated, and the recovered low frequency components will be useful for the subsequent full waveform inversion. The proposed deghosting method is currently suitable for two-dimensional towed streamer cases with accurate constant depth information and its extension into variable-depth streamers in three-dimensional cases will be studied in the future.

In vitro studies on guar gum based formulation for the colon targeted delivery of Sennosides.

PubMed

Momin, Munira; Pundarikakshudu, K

2004-09-24

The objective of the present study is to develop colon targeted drug delivery systems for sennosides using guar gum as a carrier. Matrix tablets containing various proportions of guar gum were prepared by wet granulation technique using starch paste as a binder. The tablets were evaluated for content uniformity and in vitro drug release study as per BP method. T(50) % value from the dissolution studies was taken for selecting the best formulation. Guar gum matrix tablets released 4-18% sennosides in the physiological environment of gastrointestinal tract depending on the proportion of the guar gum used in the formulation. The matrix tablets containing 50% of guar gum were found to be suitable for targeting of sennosides for local action in the colon. Compared to tablets having 30% and 40% of guar gum, those with 50% guar gum gave better T(50)% (11.7 h) le and fewer amounts (5-8%) of drug release in upper GIT. These tablets with 50% guar gum released 43% and 96% sennosides with and without rat caecal fluids. This suggests the susceptibility of matrix to the colonic micro flora. The similarity factor (f2 value) for drug release with and without rat caecal fluids was found to be less than 30. When hydroxy propyl methylcellulose phthalate (10%) was used as a coat material on the matrix tablets, the initial loss of 5-8% sennosides in stomach could be completely averted. These tablets showed no change in physical appearance, content and dissolution profile upon storage at 45 degrees C / 75% relative humidity for 3 months. The results of our study indicates that matrix tablets containing 50% guar gum and coated with 10% hydroxy propyl methylcellulose phthalate are most suitable for drugs like sennosides which are mainly active in the lower GIT.

Lyophilized mucoadhesive-dendrimer enclosed matrix tablet for extended oral delivery of albendazole.

PubMed

Mansuri, Shakir; Kesharwani, Prashant; Tekade, Rakesh Kumar; Jain, Narendra Kumar

2016-05-01

Dendrimers are multifunctional carriers widely employed for delivering drugs in a variety of disease conditions including HIV/AIDS and cancer. Albendazole (ABZ) is a commonly used anthelmintic drug in human as well as veterinary medicine. In this investigation, ABZ was formulated as a "muco-dendrimer" based sustained released tablet. The mucoadhesive complex was synthesized by anchoring chitosan to fifth generation PPI dendrimer (Muco-PPI) and characterized by UV, FTIR, (1)H NMR spectroscopy and electron microscopy. ABZ was entrapped inside Muco-PPI followed by lyophilization and tableting as matrix tablet. A half-life (t1/2) of 8.06±0.15, 8.17±0.47, 11.04±0.73, 11.49±0.92, 12.52±1.04 and 16.9±1.18h was noted for ABZ (free drug), conventional ABZ tablet (F1), conventional ABZ matrix tablet (F2), PPI-ABZ complex, PPI-ABZ matrix tablet (F3) and Muco-PPI-ABZ matrix tablet (F4), respectively. Thus the novel mucoadhesive-PPI based formulation of ABZ (F4) increased the t1/2 of ABZ significantly by almost twofold as compared to the administration of free drug. The in vivo drug release data showed that the Muco-PPI based formulations have a significantly higher Cmax (2.40±0.02μg/mL) compared with orally administered free ABZ (0.19±0.07μg/mL) as well as conventional tablet (0.20±0.05μg/mL). In addition, the Muco-PPI-ABZ matrix tablet displayed increased mean residence time (MRT) and is therefore a potential candidate to appreciably improve the pharmacokinetic profile of ABZ. Copyright © 2015 Elsevier B.V. All rights reserved.

Effects of Adiabatic Heating on the High Strain Rate Deformation of Polymer Matrix Composites

NASA Technical Reports Server (NTRS)

Sorini, Chris; Chattopadhyay, Aditi; Goldberg, Robert K.

2017-01-01

Polymer matrix composites (PMCs) are increasingly being used in aerospace structures that are expected to experience complex dynamic loading conditions throughout their lifetime. As such, a detailed understanding of the high strain rate behavior of the constituents, particularly the strain rate, temperature, and pressure dependent polymer matrix, is paramount. In this paper, preliminary efforts in modeling experimentally observed temperature rises due to plastic deformation in PMCs subjected to dynamic loading are presented. To this end, an existing isothermal viscoplastic polymer constitutive formulation is extended to model adiabatic conditions by incorporating temperature dependent elastic properties and modifying the components of the inelastic strain rate tensor to explicitly depend on temperature. It is demonstrated that the modified polymer constitutive model is capable of capturing strain rate and temperature dependent yield as well as thermal softening associated with the conversion of plastic work to heat at high rates of strain. The modified constitutive model is then embedded within a strength of materials based micromechanics framework to investigate the manifestation of matrix thermal softening, due to the conversion of plastic work to heat, on the high strain rate response of a T700Epon 862 (T700E862) unidirectional composite. Adiabatic model predictions for high strain rate composite longitudinal tensile, transverse tensile, and in-plane shear loading are presented. Results show a substantial deviation from isothermal conditions; significant thermal softening is observed for matrix dominated deformation modes (transverse tension and in-plane shear), highlighting the importance of accounting for the conversion of plastic work to heat in the polymer matrix in the high strain rate analysis of PMC structures.

A new method for the calculation of the conductivity of inhomogeneous systems

NASA Astrophysics Data System (ADS)

Byshkin, M. S.; Turkin, A. A.

2005-06-01

A new method for computing the conductivity of random irregular resistor networks is developed. This method is a generalization of the transfer-matrix technique, proposed by Derrida and Vannimenus for regular 2D and 3D lattices. At the same time for large systems the method presented in this paper is more efficient than the transfer-matrix technique. To demonstrate the method it is applied to a cubic lattice at the percolation threshold and away from it. The conductivity has been found for lattices with size up to 3243. The ratio between the conductivity exponent t and the correlation length exponent η was estimated to be t/η = 2.315, in good agreement with the literature data.

Cathepsin B is the driving force of esophageal cell invasion in a fibroblast-dependent manner.

PubMed

Andl, Claudia D; McCowan, Kelsey M; Allison, Gillian L; Rustgi, Anil K

2010-06-01

Esophageal cancer, which frequently exhibits coordinated loss of E-cadherin (Ecad) and transforming growth factor beta (TGFbeta) receptor II (TbetaRII), has a high mortality rate. In a three-dimensional organotypic culture model system, esophageal keratinocytes expressing dominant-negative mutant versions of both Ecad and TbetaRII (ECdnT) invade into the underlying matrix embedded with fibroblasts. We also find that cathepsin B induction is necessary for fibroblast-mediated invasion. Furthermore, the ECdnT cells in this physiological context activate fibroblasts through the secretion of TGFbeta1, which, in turn, is activated by cathepsin B. These results suggest that the interplay between the epithelial compartment and the surrounding microenvironment is crucial to invasion into the extracellular matrix.

Enhanced Constraints for Accurate Lower Bounds on Many-Electron Quantum Energies from Variational Two-Electron Reduced Density Matrix Theory.

PubMed

Mazziotti, David A

2016-10-07

A central challenge of physics is the computation of strongly correlated quantum systems. The past ten years have witnessed the development and application of the variational calculation of the two-electron reduced density matrix (2-RDM) without the wave function. In this Letter we present an orders-of-magnitude improvement in the accuracy of 2-RDM calculations without an increase in their computational cost. The advance is based on a low-rank, dual formulation of an important constraint on the 2-RDM, the T2 condition. Calculations are presented for metallic chains and a cadmium-selenide dimer. The low-scaling T2 condition will have significant applications in atomic and molecular, condensed-matter, and nuclear physics.

Criteria for applicability of the impulse approach to collisions

NASA Astrophysics Data System (ADS)

Sharma, Ramesh D.; Bakshi, Pradip M.; Sindoni, Joseph M.

1990-06-01

Using an exact formulation of impulse approach (IA) to atom-diatom collisions, we assess its internal consistency. By comparing the cross sections in the forward and reverse directions for the vibrational-rotational inelastic processes, using the half-on-the-shell (post and prior) models of the two-body t matrix, we show that in both cases the IA leads to a violation of the semidetailed balance (SDB) condition for small scattering angles. An off-shell model for the two-body t matrix, which preserves SDB, is shown to have other serious shortcomings. The cross sections are studied quantitatively as a function of the relative translational energy and the mass of the incident particle, and criteria discussed for the applicability of IA.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sharma, R.D.; Bakshi, P.M.; Sindoni, J.M.

Using an exact formulation of impulse approach (IA) to atom-diatom collisions, we assess its internal consistency. By comparing the cross sections in the forward and reverse directions for the vibrational-rotational inelastic processes, using the half-on-the-shell (post and prior) models of the two-body {ital t} matrix, we show that in both cases the IA leads to a violation of the semidetailed balance (SDB) condition for small scattering angles. An off-shell model for the two-body {ital t} matrix, which preserves SDB, is shown to have other serious shortcomings. The cross sections are studied quantitatively as a function of the relative translational energymore » and the mass of the incident particle, and criteria discussed for the applicability of IA.« less

Enhanced Constraints for Accurate Lower Bounds on Many-Electron Quantum Energies from Variational Two-Electron Reduced Density Matrix Theory

NASA Astrophysics Data System (ADS)

Mazziotti, David A.

2016-10-01

A central challenge of physics is the computation of strongly correlated quantum systems. The past ten years have witnessed the development and application of the variational calculation of the two-electron reduced density matrix (2-RDM) without the wave function. In this Letter we present an orders-of-magnitude improvement in the accuracy of 2-RDM calculations without an increase in their computational cost. The advance is based on a low-rank, dual formulation of an important constraint on the 2-RDM, the T 2 condition. Calculations are presented for metallic chains and a cadmium-selenide dimer. The low-scaling T 2 condition will have significant applications in atomic and molecular, condensed-matter, and nuclear physics.

Neuropeptides, via specific receptors, regulate T cell adhesion to fibronectin.

PubMed

Levite, M; Cahalon, L; Hershkoviz, R; Steinman, L; Lider, O

1998-01-15

The ability of T cells to adhere to and interact with components of the blood vessel walls and the extracellular matrix is essential for their extravasation and migration into inflamed sites. We have found that the beta1 integrin-mediated adhesion of resting human T cells to fibronectin, a major glycoprotein component of the extracellular matrix, is induced by physiologic concentrations of three neuropeptides: calcitonin gene-related protein (CGRP), neuropeptide Y, and somatostatin; each acts via its own specific receptor on the T cell membrane. In contrast, substance P (SP), which coexists with CGRP in the majority of peripheral endings of sensory nerves, including those innervating the lymphoid organs, blocks T cell adhesion to fibronectin when induced by CGRP, neuropeptide Y, somatostatin, macrophage inflammatory protein-1beta, and PMA. Inhibition of T cell adhesion was obtained both by the intact SP peptide and by its 1-4 N-terminal and its 4-11, 5-11, and 6-11 C-terminal fragments, used at similar nanomolar concentrations. The inhibitory effects of the parent SP peptide and its fragments were abrogated by an SP NK-1 receptor antagonist, suggesting they all act through the same SP NK-1 receptor. These findings suggest that neuropeptides, by activating their specific T cell-expressed receptors, can provide the T cells with both positive (proadhesive) and negative (antiadhesive) signals and thereby regulate their function. Thus, neuropeptides may influence diverse physiologic processes involving integrins, including leukocyte-mediated migration and inflammation.

Stochastic-Constraints Method in Nonstationary Hot-Clutter Cancellation Part I: Fundamentals and Supervised Training Applications

DTIC Science & Technology

2003-04-01

any of the P interfering sources, and Hkt i (1) (P)] T is defined below. The P-variate vector = t kt , • t J consists of complex waveforms radiated by...line. More precisely, the (i, j ) t element of the matrix Hke is a complex 4-4 coefficient which is practically constant over the kth PRI, and is a...multivariate auto-regressive (AR) model of order n: Ykt + Z Bj Yk- j , t = tkt (25) j =l In the above equation, Bj are the M-variate matrices which are the

Decision Support Tools for Munitions Response Performance Prediction and Risk Assessment

DTIC Science & Technology

2013-01-01

with G, the forward modeling matrix, implicitly dependent on target location. The least squares model estimate is then given by m̂ = ( GTG )−1GTdobs = G...dobs (6) with (7) G† = ( GTG )−1GT denoting the pseudo-inverse. When inverting observed field data for a sensor with tri-axial transmit and receive coils...ities can be expressed as cov(L̂) =β G†(r) cov(d) (G†(r))T βT =β G†(r) Geq α cov(L) α T GTeq (G †(r))T βT (53) where the pseudo-inverse is G† = ( GTG )−1G

Life cycle costing as a decision making tool for technology acquisition in radio-diagnosis

PubMed Central

Chakravarty, Abhijit; Debnath, Jyotindu

2014-01-01

Background Life cycle costing analysis is an emerging conceptual tool to validate capital investment in healthcare. Methods A preliminary study was done to analyze the long-term cost impact of acquiring a new 3 T MRI system when compared to technological upgradation of the existing 1.5 T MRI system with a view to evolve a decision matrix for correct investment planning and technology management. Operating costing method was utilized to estimate cost per unit MRI scan, costing inputs were considered for the existing 1.5 T and the proposed 3 T machine. Cost for each expected year in the life span of both 1.5 T and 3 T MRI scan options were then discounted to its Net Present Value. Net Present Value thus calculated for both the alternative options of 1.5 T and 3 T MRI machine was charted along with various intangible but critical Figures of Merit (FOM) to create a decision matrix for capital investment planning. Result Considering all fixed and variable costs contributing towards assumed operation, unit cost per MRI procedure was found to be Rs. 4244.58 for the 1.5 T upgrade and Rs. 6059.37 for the new 3 T MRI machine. Life Cycle Cost Analysis of the proposed 1.5 T upgrade and new 3 T machine showed a Net Present Value of Rs. 42,148,587.80 and Rs. 27,587,842.38 respectively. Conclusion The utility of life cycle costing as a strategic decision making tool towards evaluating alternative options for capital investment planning in health care environment is reiterated. PMID:25609862

Association of functional SNP-1562C>T in MMP9 promoter with proliferative diabetic retinopathy in north Indian type 2 diabetes mellitus patients.

PubMed

Singh, Kanhaiya; Goyal, Prabhjot; Singh, Manju; Deshmukh, Sujit; Upadhyay, Divyesh; Kant, Sri; Agrawal, Neeraj K; Gupta, Sanjeev K; Singh, Kiran

2017-12-01

Retinal angiogenesis is a hallmark of diabetic retinopathy. Matrix Metalloproteinases (MMPs) are involved in degradation of extracellular matrix (ECM). Functional SNP-1562C>T in the promoter of the MMP-9 gene results increase in transcriptional activity. The present work was designed to evaluate the contribution of functional SNP-1562C>T of MMP-9 gene to the risk of proliferative diabetic retinopathy (PDR) in type 2 diabetes mellitus (T2DM) patients in north Indian Population. This Case control study comprised of a total of 645 individuals in which 320 were T2DM patients out of which 73 had PDR, 98 had non- proliferative diabetic retinopathy (NPDR), 149 T2DM cases without any eye related disease (DM) and 325 non diabetic healthy individuals as controls (non DM controls). Genotyping for SNP-1562C>T of MMP-9 was done by polymerase chain reactions followed by restriction analyses with specific endonucleases (PCR-RFLP). DNA sequencing was used to ascertain PCR-RFLP results. T allele frequency in PDR patients was 32.1%, 20.4% in NPDR, 15.4% in DM and 13.7% in controls. Statistically significant difference was observed in both allele and genotype distribution between the PDR versus non-DM control group (p<0.0001 by T allele; p=0.002 by TT and p<0.0001 by CT genotype). The present study suggests that the functional SNP-1562C>T in the promoter of the MMP-9 gene could be regarded as a major risk factor for PDR as increased MMP-9 production from high expressing T allele may promote retinal angiogenesis. Copyright © 2017 Elsevier Inc. All rights reserved.

Humanized mouse model for assessing the human immune response to xenogeneic and allogeneic decellularized biomaterials.

PubMed

Wang, Raymond M; Johnson, Todd D; He, Jingjin; Rong, Zhili; Wong, Michelle; Nigam, Vishal; Behfar, Atta; Xu, Yang; Christman, Karen L

2017-06-01

Current assessment of biomaterial biocompatibility is typically implemented in wild type rodent models. Unfortunately, different characteristics of the immune systems in rodents versus humans limit the capability of these models to mimic the human immune response to naturally derived biomaterials. Here we investigated the utility of humanized mice as an improved model for testing naturally derived biomaterials. Two injectable hydrogels derived from decellularized porcine or human cadaveric myocardium were compared. Three days and one week after subcutaneous injection, the hydrogels were analyzed for early and mid-phase immune responses, respectively. Immune cells in the humanized mouse model, particularly T-helper cells, responded distinctly between the xenogeneic and allogeneic biomaterials. The allogeneic extracellular matrix derived hydrogels elicited significantly reduced total, human specific, and CD4 + T-helper cell infiltration in humanized mice compared to xenogeneic extracellular matrix hydrogels, which was not recapitulated in wild type mice. T-helper cells, in response to the allogeneic hydrogel material, were also less polarized towards a pro-remodeling Th2 phenotype compared to xenogeneic extracellular matrix hydrogels in humanized mice. In both models, both biomaterials induced the infiltration of macrophages polarized towards a M2 phenotype and T-helper cells polarized towards a Th2 phenotype. In conclusion, these studies showed the importance of testing naturally derived biomaterials in immune competent animals and the potential of utilizing this humanized mouse model for further studying human immune cell responses to biomaterials in an in vivo environment. Copyright © 2017 Elsevier Ltd. All rights reserved.

Universality in chaos: Lyapunov spectrum and random matrix theory.

PubMed

Hanada, Masanori; Shimada, Hidehiko; Tezuka, Masaki

2018-02-01

We propose the existence of a new universality in classical chaotic systems when the number of degrees of freedom is large: the statistical property of the Lyapunov spectrum is described by random matrix theory. We demonstrate it by studying the finite-time Lyapunov exponents of the matrix model of a stringy black hole and the mass-deformed models. The massless limit, which has a dual string theory interpretation, is special in that the universal behavior can be seen already at t=0, while in other cases it sets in at late time. The same pattern is demonstrated also in the product of random matrices.

Universality in chaos: Lyapunov spectrum and random matrix theory

NASA Astrophysics Data System (ADS)

Hanada, Masanori; Shimada, Hidehiko; Tezuka, Masaki

2018-02-01

We propose the existence of a new universality in classical chaotic systems when the number of degrees of freedom is large: the statistical property of the Lyapunov spectrum is described by random matrix theory. We demonstrate it by studying the finite-time Lyapunov exponents of the matrix model of a stringy black hole and the mass-deformed models. The massless limit, which has a dual string theory interpretation, is special in that the universal behavior can be seen already at t =0 , while in other cases it sets in at late time. The same pattern is demonstrated also in the product of random matrices.

CP Violation (4/4)

ScienceCinema

Raven, G.

2018-05-23

Existence of antimatter is a consequence of the combination of special relativity and quantum mechanics. No 'primordial' antimatter's observed, need CP violation. CP broken by the charged weak interaction. The weak and mass eigenstates of quarks are different, and this difference is described by the CKM matrix. There is a clear (and unexplained!) hierarchical structure to the CKM matrix...with 3 (or more families, one can have a complex phase(s) in the CKM matrix, and this allows for CP violation! Measurements show that CKM describes the dominant (only?) source of CP violation (at the EW scale). But it doesn't explain the matter--antimatter asymmetry of the universe.

Environmentally Compliant Vinyl Ester Resin (VER) Composite Matrix Resin Derived from Renewable Resources

DTIC Science & Technology

2011-11-01

Carbon Fiber Production– 02FCC-144”; C.F. Leit- ten, Jr., W.L. Griffith, A.L. Compere , and J.T. Shaffer, Society of Automotive Engineers, Inc., 2001. 8...Cost Carbon Fiber from Renewable Resources”; A.L. Compere , W.L. Griffith, C.F. Leitten, Jr., and J.T. Shaffer, Oak Ridge National Laboratory Report

Methods for Scaling to Doubly Stochastic Form,

DTIC Science & Technology

1981-06-26

Frobenius -Konig Theorem (MARCUS and MINC [1964],p 97) A nonnegative n xn matrix without support contains an s x t zero subma- trix where: s +t =n + -3...that YA(k) has row sums 1. Then normalize the columns by a diagonal similarity transform defined as follows: Let x = (zx , • z,,) be a left Perron vector

Emergency Destruction of Information Storing Media. Appendix 1. Analysis Matrix

DTIC Science & Technology

1987-12-01

DM0F (Tow. Mm~k DW) -7 PAME COunT 7he MDA Report was prepared 1w lbs Cmrnimr Specs md Naval VUrfee Sytem Coinmd sad t&e NOSomi CMPW Seemby Come. It...destruction. B-6 - I I Destruct Method: METANICALM ATION, abm e achion Storage Medium: Magnetic, Recording, Tape, Carridps (Cassettes Wafers

Functional Assessment of Skeletal Muscle Regeneration Utilizing Homologous Extracellular Matrix as Scaffolding

DTIC Science & Technology

2010-01-01

as a biologic scaffold material. Biomaterials 28, 3587, 2007. 24. Conconi, M.T., De Coppi, P., Bellini, S., Zara , G., Sabatti, M., Marzaro, M., Zanon...full-thickness ab- dominal wall defects. Tissue Eng 12, 1929, 2006. 26. Gamba, P.G., Conconi, M.T., Lo Piccolo, R., Zara , G., Spi- nazzi, R., and

Competition Between Pairing and Ferromagnetic Instabilities in Ultracold Fermi Gases Near Feshbach Resonances

DTIC Science & Technology

2010-05-13

see the inset of Fig. 1). Thus, the two-body pairing process becomes for- bidden when the binding energy ∼ 1/ ma2 exceeds the maxi- mum energy that can...matrix in vacuum. For each value of the scattering length, the T-matrix has a line of poles on the BEC side located at ωq = Ωq+i∆q = −1/ ma2 + mq2/4

Light Scattering by Wavelength-Sized Particles "Dusted" with Subwavelength-Sized Grains

NASA Technical Reports Server (NTRS)

Mishchenko, Michael I.; Dlugach, Janna M.; Mackowski, Daniel W.

2011-01-01

The numerically exact superposition T-matrix method is used to compute the scattering cross sections and the Stokes scattering matrix for polydisperse spherical particles covered with a large number of much smaller grains. We show that the optical effect of the presence of microscopic dust on the surfaces of wavelength-sized, weakly absorbing particles is much less significant than that of a major overall asphericity of the particle shape.

Gated photochemical hole burning in photoadducts of polyacenes

NASA Technical Reports Server (NTRS)

Iannone, Mark; Scott, Gary W.; Brinza, David; Coulter, Daniel R.

1986-01-01

A photoadduct of anthracene and tetracene (A-T) in a polymer matrix at 1.5 K generates an absorption spectrum which exhibits two-color, photon-gated photochemical hole burning (PHB) when irradiated with narrowband exciting light into the 0-0 band of the S1-S0 absorption. The efficiency of this PHB process is found to be enhanced by simultaneous irradiation near the maximum of the Tn-T1 absorption of A-T; hole widths of less than 0.07/cm have been observed for this photochemical cleavage of A-T.

Longitudinal Relaxation of Ferromagnetic Grains

NASA Astrophysics Data System (ADS)

Würger, Alois

1998-07-01

We study the activated longitudinal dynamics of a small single-domain magnet with uniaxial anisotropy, coupled to quantum noise. The smallest finite eigenvalue λ1 = γ0e-EB/kBT of the relaxation matrix is evaluated in a controlled approximation. For white noise we find γ0~T-1 at moderate temperatures and γ0 = const at very low T. Coupling to elastic waves leads to a prefactor that is linear in T or constant, depending on temperature. At very low T, the discreteness of the energy spectrum is crucial.

Conformations of n-butyl imidazole: matrix isolation infrared and DFT studies.

PubMed

Ramanathan, N; Sundararajan, K; Sankaran, K

2015-03-15

Conformations of n-butyl imidazole (B-IMID) were studied using matrix isolation infrared spectroscopy by trapping in argon, xenon and nitrogen matrixes using an effusive nozzle source. The experimental studies were supported by DFT computations performed at the B3LYP/6-311++G(d,p) level. Computations identified nine unique minima for B-IMID, corresponding to conformers with tg(±)tt, tg(±)g(∓)t, tg(±)g(±)t, tg(±)tg(±), tg(±)tg(∓), tg(±)g(∓)g(∓), tg(±)g(±)g(±), tg(±)g(∓)g(±) and tg(±)g(±)g(∓) structures, given in order of increasing energy. Computations of the transition state structures connecting the higher energy conformers to the global minimum, tg(±)tt structure were carried out. The barriers for the conformer inter-conversion were found to be ∼2 kcal/mol. Natural Bond Orbital (NBO) analysis was performed to understand the reasons for conformational preferences in B-IMID. Copyright © 2014 Elsevier B.V. All rights reserved.

Friction Stir Welding of Al Alloy 2219-T8: Part II-Mechanical and Corrosion

NASA Astrophysics Data System (ADS)

Kang, Ju; Feng, Zhi-Cao; Li, Ji-Chao; Frankel, G. S.; Wang, Guo-Qing; Wu, Ai-Ping

2016-09-01

In Part I of this series, abnormal agglomerations of θ particles with size of about 100 to 1000 µm were observed in friction stir welded AA2219-T8 joints. In this work, the effects of these agglomerated θ particles on the mechanical and corrosion properties of the joints are studied. Tensile testing with in situ SEM imaging was utilized to monitor crack initiation and propagation in base metal and weld nugget zone (WNZ) samples. These tests showed that cracks initiated in the θ particles and at the θ/matrix interfaces, but not in the matrix. The WNZ samples containing abnormal agglomerated θ particles had a similar ultimate tensile stress but 3 pct less elongation than other WNZ samples with only normal θ particles. Measurements using the microcell technique indicated that the agglomerated θ particles acted as a cathode causing the dissolution of adjacent matrix. The abnormal θ particle agglomerations led to more severe localized attack due to the large cathode/anode ratio. Al preferential dissolution occurred in the abnormal θ particle agglomerations, which was different from the corrosion behavior of normal size θ particles.

Top-quark mass measurement from dilepton events at CDF II.

PubMed

Abulencia, A; Acosta, D; Adelman, J; Affolder, T; Akimoto, T; Albrow, M G; Ambrose, D; Amerio, S; Amidei, D; Anastassov, A; Anikeev, K; Annovi, A; Antos, J; Aoki, M; Apollinari, G; Arguin, J-F; Arisawa, T; Artikov, A; Ashmanskas, W; Attal, A; Azfar, F; Azzi-Bacchetta, P; Azzurri, P; Bacchetta, N; Bachacou, H; Badgett, W; Barbaro-Galtieri, A; Barnes, V E; Barnett, B A; Baroiant, S; Bartsch, V; Bauer, G; Bedeschi, F; Behari, S; Belforte, S; Bellettini, G; Bellinger, J; Belloni, A; Ben-Haim, E; Benjamin, D; Beretvas, A; Beringer, J; Berry, T; Bhatti, A; Binkley, M; Bisello, D; Bishai, M; Blair, R E; Blocker, C; Bloom, K; Blumenfeld, B; Bocci, A; Bodek, A; Boisvert, V; Bolla, G; Bolshov, A; Bortoletto, D; Boudreau, J; Bourov, S; Boveia, A; Brau, B; Bromberg, C; Brubaker, E; Budagov, J; Budd, H S; Budd, S; Burkett, K; Busetto, G; Bussey, P; Byrum, K L; Cabrera, S; Campanelli, M; Campbell, M; Canelli, F; Canepa, A; Carlsmith, D; Carosi, R; Carron, S; Casarsa, M; Castro, A; Catastini, P; Cauz, D; Cavalli-Sforza, M; Cerri, A; Cerrito, L; Chang, S H; Chapman, J; Chen, Y C; Chertok, M; Chiarelli, G; Chlachidze, G; Chlebana, F; Cho, I; Cho, K; Chokheli, D; Chou, J P; Chu, P H; Chuang, S H; Chung, K; Chung, W H; Chung, Y S; Ciljak, M; Ciobanu, C I; Ciocci, M A; Clark, A; Clark, D; Coca, M; Connolly, A; Convery, M E; Conway, J; Cooper, B; Copic, K; Cordelli, M; Cortiana, G; Cruz, A; Cuevas, J; Culbertson, R; Cyr, D; DaRonco, S; D'Auria, S; D'Onofrio, M; Dagenhart, D; de Barbaro, P; De Cecco, S; Deisher, A; De Lentdecker, G; Dell'Orso, M; Demers, S; Demortier, L; Deng, J; Deninno, M; De Pedis, D; Derwent, P F; Dionisi, C; Dittmann, J; Dituro, P; Dörr, C; Dominguez, A; Donati, S; Donega, M; Dong, P; Donini, J; Dorigo, T; Dube, S; Ebina, K; Efron, J; Ehlers, J; Erbacher, R; Errede, D; Errede, S; Eusebi, R; Fang, H C; Farrington, S; Fedorko, I; Fedorko, W T; Feild, R G; Feindt, M; Fernandez, J P; Field, R; Flanagan, G; Flores-Castillo, L R; Foland, A; Forrester, S; Foster, G W; Franklin, M; Freeman, J C; Fujii, Y; Furic, I; Gajjar, A; Gallinaro, M; Galyardt, J; Garcia, J E; Garcia Sciverez, M; Garfinkel, A F; Gay, C; Gerberich, H; Gerchtein, E; Gerdes, D; Giagu, S; Giannetti, P; Gibson, A; Gibson, K; Ginsburg, C; Giolo, K; Giordani, M; Giunta, M; Giurgiu, G; Glagolev, V; Glenzinski, D; Gold, M; Goldschmidt, N; Goldstein, J; Gomez, G; Gomez-Ceballos, G; Goncharov, M; González, O; Gorelov, I; Goshaw, A T; Gotra, Y; Goulianos, K; Gresele, A; Griffiths, M; Grinstein, S; Grosso-Pilcher, C; Grundler, U; Guimaraes da Costa, J; Haber, C; Hahn, S R; Hahn, K; Halkiadakis, E; Hamilton, A; Han, B-Y; Handler, R; Happacher, F; Hara, K; Hare, M; Harper, S; Harr, R F; Harris, R M; Hatakeyama, K; Hauser, J; Hays, C; Hayward, H; Heijboer, A; Heinemann, B; Heinrich, J; Hennecke, M; Herndon, M; Heuser, J; Hidas, D; Hill, C S; Hirschbuehl, D; Hocker, A; Holloway, A; Hou, S; Houlden, M; Hsu, S-C; Huffman, B T; Hughes, R E; Huston, J; Ikado, K; Incandela, J; Introzzi, G; Iori, M; Ishizawa, Y; Ivanov, A; Iyutin, B; James, E; Jang, D; Jayatilaka, B; Jeans, D; Jensen, H; Jeon, E J; Jones, M; Joo, K K; Jun, S Y; Junk, T R; Kamon, T; Kang, J; Karagoz-Unel, M; Karchin, P E; Kato, Y; Kemp, Y; Kephart, R; Kerzel, U; Khotilovich, V; Kilminster, B; Kim, D H; Kim, H S; Kim, J E; Kim, M J; Kim, M S; Kim, S B; Kim, S H; Kim, Y K; Kirby, M; Kirsch, L; Klimenko, S; Klute, M; Knuteson, B; Ko, B R; Kobayashi, H; Kondo, K; Kong, D J; Konigsberg, J; Kordas, K; Korytov, A; Kotwal, A V; Kovalev, A; Kraus, J; Kravchenko, I; Kreps, M; Kreymer, A; Kroll, J; Krumnack, N; Kruse, M; Krutelyov, V; Kuhlmann, S E; Kusakabe, Y; Kwang, S; Laasanen, A T; Lai, S; Lami, S; Lami, S; Lammel, S; Lancaster, M; Lander, R L; Lannon, K; Lath, A; Latino, G; Lazzizzera, I; Lecci, C; LeCompte, T; Lee, J; Lee, J; Lee, S W; Lefèvre, R; Leonardo, N; Leone, S; Levy, S; Lewis, J D; Li, K; Lin, C; Lin, C S; Lindgren, M; Lipeles, E; Liss, T M; Lister, A; Litvintsev, D O; Liu, T; Liu, Y; Lockyer, N S; Loginov, A; Loreti, M; Loverre, P; Lu, R-S; Lucchesi, D; Lujan, P; Lukens, P; Lungu, G; Lyons, L; Lys, J; Lysak, R; Lytken, E; Mack, P; MacQueen, D; Madrak, R; Maeshima, K; Maki, T; Maksimovic, P; Manca, G; Margaroli, F; Marginean, R; Marino, C; Martin, A; Martin, M; Martin, V; Martínez, M; Maruyama, T; Matsunaga, H; Mattson, M E; Mazini, R; Mazzanti, P; McFarland, K S; McGivern, D; McIntyre, P; McNamara, P; McNulty, R; Mehta, A; Menzemer, S; Menzione, A; Merkel, P; Mesropian, C; Messina, A; von der Mey, M; Miao, T; Miladinovic, N; Miles, J; Miller, R; Miller, J S; Mills, C; Milnik, M; Miquel, R; Miscetti, S; Mitselmakher, G; Miyamoto, A; Moggi, N; Mohr, B; Moore, R; Morello, M; Movilla Fernandez, P; Mülmenstädt, J; Mukherjee, A; Mulhearn, M; Muller, Th; Mumford, R; Murat, P; Nachtman, J; Nahn, S; Nakano, I; Napier, A; Naumov, D; Necula, V; Neu, C; Neubauer, M S; Nielsen, J; Nigmanov, T; Nodulman, L; Norniella, O; Ogawa, T; Oh, S H; Oh, Y D; Okusawa, T; Oldeman, R; Orava, R; Osterberg, K; Pagliarone, C; Palencia, E; Paoletti, R; Papadimitriou, V; Papikonomou, A; Paramonov, A A; Parks, B; Pashapour, S; Patrick, J; Pauletta, G; Paulini, M; Paus, C; Pellett, D E; Penzo, A; Phillips, T J; Piacentino, G; Piedra, J; Pitts, K; Plager, C; Pondrom, L; Pope, G; Portell, X; Poukhov, O; Pounder, N; Prakoshyn, F; Pronko, A; Proudfoot, J; Ptohos, F; Punzi, G; Pursley, J; Rademacker, J; Rahaman, A; Rakitin, A; Rappoccio, S; Ratnikov, F; Reisert, B; Rekovic, V; van Remortel, N; Renton, P; Rescigno, M; Richter, S; Rimondi, F; Rinnert, K; Ristori, L; Robertson, W J; Robson, A; Rodrigo, T; Rogers, E; Rolli, S; Roser, R; Rossi, M; Rossin, R; Rott, C; Ruiz, A; Russ, J; Rusu, V; Ryan, D; Saarikko, H; Sabik, S; Safonov, A; Sakumoto, W K; Salamanna, G; Salto, O; Saltzberg, D; Sanchez, C; Santi, L; Sarkar, S; Sato, K; Savard, P; Savoy-Navarro, A; Scheidle, T; Schlabach, P; Schmidt, E E; Schmidt, M P; Schmitt, M; Schwarz, T; Scodellaro, L; Scott, A L; Scribano, A; Scuri, F; Sedov, A; Seidel, S; Seiya, Y; Semenov, A; Semeria, F; Sexton-Kennedy, L; Sfiligoi, I; Shapiro, M D; Shears, T; Shepard, P F; Sherman, D; Shimojima, M; Shochet, M; Shon, Y; Shreyber, I; Sidoti, A; Sill, A; Sinervo, P; Sisakyan, A; Sjolin, J; Skiba, A; Slaughter, A J; Sliwa, K; Smirnov, D; Smith, J R; Snider, F D; Snihur, R; Soderberg, M; Soha, A; Somalwar, S; Sorin, V; Spalding, J; Spinella, F; Squillacioti, P; Stanitzki, M; Staveris-Polykalas, A; St Denis, R; Stelzer, B; Stelzer-Chilton, O; Stentz, D; Strologas, J; Stuart, D; Suh, J S; Sukhanov, A; Sumorok, K; Sun, H; Suzuki, T; Taffard, A; Tafirout, R; Takashima, R; Takeuchi, Y; Takikawa, K; Tanaka, M; Tanaka, R; Tecchio, M; Teng, P K; Terashi, K; Tether, S; Thom, J; Thompson, A S; Thomson, E; Tipton, P; Tiwari, V; Tkaczyk, S; Toback, D; Tollefson, K; Tomura, T; Tonelli, D; Tönnesmann, M; Torre, S; Torretta, D; Tourneur, S; Trischuk, W; Tsuchiya, R; Tsuno, S; Turini, N; Ukegawa, F; Unverhau, T; Uozumi, S; Usynin, D; Vacavant, L; Vaiciulis, A; Vallecorsa, S; Varganov, A; Vataga, E; Velev, G; Veramendi, G; Veszpremi, V; Vickey, T; Vidal, R; Vila, I; Vilar, R; Vollrath, I; Volobouev, I; Würthwein, F; Wagner, P; Wagner, R G; Wagner, R L; Wagner, W; Wallny, R; Walter, T; Wan, Z; Wang, M J; Wang, S M; Warburton, A; Ward, B; Waschke, S; Waters, D; Watts, T; Weber, M; Wester, W C; Whitehouse, B; Whiteson, D; Wicklund, A B; Wicklund, E; Williams, H H; Wilson, P; Winer, B L; Wittich, P; Wolbers, S; Wolfe, C; Worm, S; Wright, T; Wu, X; Wynne, S M; Yagil, A; Yamamoto, K; Yamaoka, J; Yamashita, Y; Yang, C; Yang, U K; Yao, W M; Yeh, G P; Yoh, J; Yorita, K; Yoshida, T; Yu, I; Yu, S S; Yun, J C; Zanello, L; Zanetti, A; Zaw, I; Zetti, F; Zhang, X; Zhou, J; Zucchelli, S

2006-04-21

We report a measurement of the top-quark mass using events collected by the CDF II detector from pp collisions at square root of s = 1.96 TeV at the Fermilab Tevatron. We calculate a likelihood function for the top-quark mass in events that are consistent with tt --> bl(-)nu(l)bl'+ nu'(l) decays. The likelihood is formed as the convolution of the leading-order matrix element and detector resolution functions. The joint likelihood is the product of likelihoods for each of 33 events collected in 340 pb(-1) of integrated luminosity, yielding a top-quark mass M(t) = 165.2 +/- 6.1(stat) +/- 3.4(syst) GeV/c2. This first application of a matrix-element technique to tt --> bl+ nu(l)bl'- nu(l') decays gives the most precise single measurement of M(t) in dilepton events. Combined with other CDF run II measurements using dilepton events, we measure M(t) = 167.9 +/- 5.2(stat) +/- 3.7(syst) GeV/c2.

Full Quantum Dynamics Simulation of a Realistic Molecular System Using the Adaptive Time-Dependent Density Matrix Renormalization Group Method.

PubMed

Yao, Yao; Sun, Ke-Wei; Luo, Zhen; Ma, Haibo

2018-01-18

The accurate theoretical interpretation of ultrafast time-resolved spectroscopy experiments relies on full quantum dynamics simulations for the investigated system, which is nevertheless computationally prohibitive for realistic molecular systems with a large number of electronic and/or vibrational degrees of freedom. In this work, we propose a unitary transformation approach for realistic vibronic Hamiltonians, which can be coped with using the adaptive time-dependent density matrix renormalization group (t-DMRG) method to efficiently evolve the nonadiabatic dynamics of a large molecular system. We demonstrate the accuracy and efficiency of this approach with an example of simulating the exciton dissociation process within an oligothiophene/fullerene heterojunction, indicating that t-DMRG can be a promising method for full quantum dynamics simulation in large chemical systems. Moreover, it is also shown that the proper vibronic features in the ultrafast electronic process can be obtained by simulating the two-dimensional (2D) electronic spectrum by virtue of the high computational efficiency of the t-DMRG method.

Microstrip Butler matrix design and realization for 7 T MRI.

PubMed

Yazdanbakhsh, Pedram; Solbach, Klaus

2011-07-01

This article presents the design and realization of 8 × 8 and 16 × 16 Butler matrices for 7 T MRI systems. With the focus on low insertion loss and high amplitude/phase accuracy, the microstrip line integration technology (microwave-integrated circuit) was chosen for the realization. Laminate material of high permittivity (ε(r) = 11) and large thickness (h = 3.2 mm) is shown to allow the best trade-off of circuit board size versus insertion loss, saving circuit area by extensive folding of branch-line coupler topology and meandering phase shifter and connecting strip lines and reducing mutual coupling of neighboring strip lines by shield structures between strip lines. With this approach, 8 × 8 Butler matrices were produced in single boards of 310 mm × 530 mm, whereas the 16 × 16 Butler matrices combined two submatrices of 8 × 8 with two smaller boards. Insertion loss was found at 0.73 and 1.1 dB for an 8 × 8 matrix and 16 × 16 matrix, respectively. Measured amplitude and phase errors are shown to represent highly pure mode excitation with unwanted modes suppressed by 40 and 35 dB, respectively. Both types of matrices were implemented with a 7 T MRI system and 8- and 16-element coil arrays for RF mode shimming experiments and operated successfully with 8 kW of RF power. Copyright © 2011 Wiley-Liss, Inc.

Applications of Correlation Techniques for Battlefield Identification I.

DTIC Science & Technology

1984-06-30

Participants: .. Carolynn Black Rick Clough Jeanie Fiskin Fif Ghobadian P- Bob Hammett Mary Hernried Lee Leong . Joe Martinetto. d ,i,=r:,,ti b ,: ., , . Glenn... equations . The Clinic team named the process of finding the coefficients matrix "backsolving" since the algorithm starts with the. desired result (the...independent of one another. The jth component of each vector satisfies the equation x3(t) -P + YO(t) where xj(t) is the value of the ith characteristic at

Fully constrained Majorana neutrino mass matrices using \\varvec{Σ(72× 3)}

NASA Astrophysics Data System (ADS)

Krishnan, R.; Harrison, P. F.; Scott, W. G.

2018-01-01

In 2002, two neutrino mixing ansatze having trimaximally mixed middle (ν _2) columns, namely tri-chi-maximal mixing ( {T}χ {M}) and tri-phi-maximal mixing ( {T}φ {M}), were proposed. In 2012, it was shown that {T}χ {M} with χ =± π /16 as well as {T}φ {M} with φ = ± π /16 leads to the solution, sin ^2 θ _{13} = 2/3 sin ^2 π /16, consistent with the latest measurements of the reactor mixing angle, θ _{13}. To obtain {T}χ {M}_{(χ =± π /16)} and {T}φ {M}_{(φ =± π /16)}, the type I see-saw framework with fully constrained Majorana neutrino mass matrices was utilised. These mass matrices also resulted in the neutrino mass ratios, m_1:m_2:m_3=( 2+√{2}) /1+√{2(2+√{2)}}:1:( 2+√{2}) /-1+√{2(2+√{2)}}. In this paper we construct a flavour model based on the discrete group Σ (72× 3) and obtain the aforementioned results. A Majorana neutrino mass matrix (a symmetric 3× 3 matrix with six complex degrees of freedom) is conveniently mapped into a flavon field transforming as the complex six-dimensional representation of Σ (72× 3). Specific vacuum alignments of the flavons are used to arrive at the desired mass matrices.

Thermalization and revivals after a quantum quench in conformal field theory.

PubMed

Cardy, John

2014-06-06

We consider a quantum quench in a finite system of length L described by a 1+1-dimensional conformal field theory (CFT), of central charge c, from a state with finite energy density corresponding to an inverse temperature β≪L. For times t such that ℓ/2

Detecting T-cell reactivity to whole cell vaccines

PubMed Central

Brusic, Ana; Hainz, Ursula; Wadleigh, Martha; Neuberg, Donna; Su, Mei; Canning, Christine M.; DeAngelo, Daniel J.; Stone, Richard M.; Lee, Jeng-Shin; Mulligan, Richard C.; Ritz, Jerome; Dranoff, Glenn; Sasada, Tetsuro; Wu, Catherine J.

2012-01-01

BCR-ABL+ K562 cells hold clinical promise as a component of cancer vaccines, either as bystander cells genetically modified to express immunostimulatory molecules, or as a source of leukemia antigens. To develop a method for detecting T-cell reactivity against K562 cell-derived antigens in patients, we exploited the dendritic cell (DC)-mediated cross-presentation of proteins generated from apoptotic cells. We used UVB irradiation to consistently induce apoptosis of K562 cells, which were then fed to autologous DCs. These DCs were used to both stimulate and detect antigen-specific CD8+ T-cell reactivity. As proof-of-concept, we used cross-presented apoptotic influenza matrix protein-expressing K562 cells to elicit reactivity from matrix protein-reactive T cells. Likewise, we used this assay to detect increased anti-CML antigen T-cell reactivity in CML patients that attained long-lasting clinical remissions following immunotherapy (donor lymphocyte infusion), as well as in 2 of 3 CML patients vaccinated with lethally irradiated K562 cells that were modified to secrete high levels of granulocyte macrophage colony-stimulating factor (GM-CSF). This methodology can be readily adapted to examine the effects of other whole tumor cell-based vaccines, a scenario in which the precise tumor antigens that stimulate immune responses are unknown. PMID:23170257

Genetic polymorphism in matrix metalloproteinase-9 and transforming growth factor-β1 and susceptibility to combined pulmonary fibrosis and emphysema in a Chinese population.

PubMed

Xu, Ling; Bian, Wei; Gu, Xiao-Hua; Shen, Ce

2017-03-01

In this study, we aimed to explore the association of genetic polymorphism in matrix metalloproteinase-9 (MMP-9) and transforming growth factor-β1 (TGF-β1) and the susceptibility to combined pulmonary fibrosis and emphysema (CPFE). We examined the polymorphisms of the MMP-9 C-1562T and TGF-β1 T869C in 38 CPFE patients, 50 pulmonary emphysema patients, and 34 idiopathic pulmonary fibrosis (IPF) patients. The frequencies of polymorphic genotypes in MMP-9 were 78.95% CC and 21.05% CT in CPFE group, 76.0% CC and 24.0% CT in emphysema group, and 100.0% CC in IPF group. There were highly statistically significant increased frequencies of the CT genotype and T allele in CPFE and emphysema groups compared with IPF group (p < 0.05). The frequencies of polymorphic genotypes in TGF-β1 were 2.63% CC, 28.95% CT, 68.42% TT in CPFE group, 4.00% CC, 16.00% CT, 80.00% TT in emphysema group, and 5.88% CC, 41.18% CT, 52.94% TT in IPF group. Significant increases in the TT genotype and T allele frequencies were observed in emphysema group compared with IPF group (p < 0.05). Our study has showed that T allele in MMP-9 (C-1562T) and T allele in TGF-β1 (T869C) are risk factors of pulmonary emphysema. The T allele in MMP-9 (C-1562T) possibly predisposes patients with pulmonary fibrosis to develop emphysema. Copyright © 2017. Published by Elsevier Taiwan.

[Preparation of acellular matrix from antler cartilage and its biological compatibility].

PubMed

Fu, Jing; Zhang, Wei; Zhang, Aiwu; Ma, Lijuan; Chu, Wenhui; Li, Chunyi

2017-06-01

To study the feasibility of acellular matrix materials prepared from deer antler cartilage and its biological compatibility so as to search for a new member of the extracellular matrix family for cartilage regeneration. The deer antler mesenchymal (M) layer tissue was harvested and treated through decellular process to prepare M layer acellular matrix; histologic observation and detection of M layer acellular matrix DNA content were carried out. The antler stem cells [antlerogenic periosteum (AP) cells] at 2nd passage were labelled by fluorescent stains and by PKH26. Subsequently, the M layer acellular matrix and the AP cells at 2nd passage were co-cultured for 7 days; then the samples were transplanted into nude mice to study the tissue compatibility of M layer acellular matrix in the living animals. HE and DAPI staining confirmed that the M layer acellular matrix did not contain nucleus; the DNA content of the M layer acellular matrix was (19.367±5.254) ng/mg, which was significantly lower than that of the normal M layer tissue [(3 805.500±519.119) ng/mg]( t =12.630, P =0.000). In vitro co-culture experiments showed that AP cells could adhere to or even embedded in the M layer acellular matrix. Nude mice transplantation experiments showed that the introduced AP cells could proliferate and induce angiogenesis in the M layer acellular matrix. The deer antler cartilage acellular matrix is successfully prepared. The M layer acellular matrix is suitable for adhesion and proliferation of AP cells in vitro and in vivo , and it has the function of stimulating angiogenesis. This model for deer antler cartilage acellular matrix can be applied in cartilage tissue engineering in the future.

Impact of nicotine on the interplay between human periodontal ligament cells and CD4+ T cells.

PubMed

Ge, Xin; Liu, Ying-Feng; Wong, Yong; Wu, Li-Zheng; Tan, Ling; Liu, Fen; Wang, Xiao-Jing

2016-09-01

Periodontitis is a common infectious disease associated with destruction of periodontal ligaments and alveolar bones. CD4(+) T cell-mediated immune response is involved in the progression of periodontitis. Tobacco consumption increases the risk of periodontal disease. However, the impact of nicotine on the interaction between human periodontal ligament (PDL) cells and CD4(+) T cells remains unrevealed. Our study aims to investigate the effect of nicotine on PDL cells and the cocultured CD4(+) T cells. The PDL cell cultures were established by explants from healthy individuals, exposed to nicotine or α-bungarotoxin (α-BTX), and incubated solely or in combination with CD4(+) T cells. Afterwards, cell viability, secreted cytokines, and matrix metalloproteinases (MMPs) were evaluated. In monoculture of PDL cells, nicotine dramatically repressed cell viability and increased apoptosis. Meanwhile, α-BTX largely reversed the nicotine-induced apoptosis and increased viability of PDL cells. Compared with the monoculture, MMP-1, MMP-3, interleukin (IL)-1β, IL-6, IL-17, and IL-21 in supernatant of cocultures were markedly elevated after treatment with nicotine. Moreover, α-BTX significantly attenuated nicotine-triggered production of these components either in mono- or co-cultures. In addition, PDL cell-derived CXCL12 following nicotine treatment recruited CD4(+) T cells. Above all, nicotine deteriorated periodontitis partially by promoting PDL cell-CD4(+) T cell-mediated inflammatory response and matrix degradation. © The Author(s) 2015.

The High-Temperature Wear and Oxidation Behavior of CrC-Based HVOF Coatings

NASA Astrophysics Data System (ADS)

Houdková, Šárka; Česánek, Zdeněk; Smazalová, Eva; Lukáč, František

2018-01-01

Three commercially available chromium carbide-based powders with different kinds of matrix (Cr3C2-25%NiCr; Cr3C2-25%CoNiCrAlY and Cr3C2-50%NiCrMoNb) were deposited by an HVOF JP-5000 spraying gun, evaluated and compared. The influence of heat treatment on the microstructure and properties, as well as the oxidation resistance in a hot steam environment ( p = 24 MPa; T = 609 °C), was evaluated by SEM and XRD with respect to their potential application in the steam power industry. The sliding wear resistance measured at room and elevated ( T = 600 °C) temperatures according to ASTM G-133. For all three kinds of chromium carbide-based coatings, the precipitation of secondary carbides from the supersaturated matrix was observed during the heat treatment. For Cr3C2-25%NiCr coating annealed in hot steam environment as well as for Cr3C2-25%CoNiCrAlY coating in both environments, the inner carbide oxidation was recorded. The sliding wear resistance was found equal at room temperature, regardless of the matrix composition and content, while at elevated temperatures, the higher wear was measured, varying in dependence on the matrix composition and content. The chromium carbide-based coating with modified matrix composition Cr3C2-50%NiCrMoNb is suitable to replace the Cr3C2-25%NiCr coating in a hot steam environment to eliminate the risk of failure caused by inner carbide oxidation.

Compressive Strength of Notched Poly(Phenylene Sulfide) Aerospace Composite: Influence of Fatigue and Environment

NASA Astrophysics Data System (ADS)

Niitsu, G. T.; Lopes, C. M. A.

2013-08-01

The purpose of this work is to evaluate the influences of fatigue and environmental conditions (-55 °C, 23 °C, and 82 °C/Wet) on the ultimate compression strength of notched carbon-fiber-reinforced poly(phenylene sulfide) composites by performing open-hole compression (OHC) tests. Analysis of the fatigue effect showed that at temperatures of -55 and 23 °C, the ultimate OHC strengths were higher for fatigued than for not-fatigued specimens; this could be attributed to fiber splitting and delamination during fatigue cycling, which reduces the stress concentration at the hole edge, thus increasing the composite strength. This effect of increasing strength for fatigued specimens was not observed under the 82 °C/Wet conditions, since the test temperature near the matrix glass transition temperature ( T g) together with moisture content resulted in matrix softening, suggesting a reduction in fiber splitting during cycling; similar OHC strengths were verified for fatigued and not-fatigued specimens tested at 82 °C/Wet. Analysis of the temperature effect showed that the ultimate OHC strengths decreased with increasing temperature. A high temperature together with moisture content (82 °C/Wet condition) reduced the composite compressive strengths, since a temperature close to the matrix T g resulted in matrix softening, which reduced the lateral support provided by the resin to the 0° fibers, leading to fiber instability failure at reduced applied loads. On the other hand, a low temperature (-55 °C) improved the compressive strength because of possible fiber-matrix interfacial strengthening, increasing the fiber contribution to compressive strength.

Matrix-free mass spectrometric imaging using laser desorption ionisation Fourier transform ion cyclotron resonance mass spectrometry

PubMed Central

Goodwin, Richard J A; Pitt, Andrew R; Harrison, David; Weidt, Stefan K; Langridge-Smith, Pat R R; Barrett, Michael P; Logan Mackay, C

2011-01-01

Mass spectrometry imaging (MSI) is a powerful tool in metabolomics and proteomics for the spatial localization and identification of pharmaceuticals, metabolites, lipids, peptides and proteins in biological tissues. However, sample preparation remains a crucial variable in obtaining the most accurate distributions. Common washing steps used to remove salts, and solvent-based matrix application, allow analyte spreading to occur. Solvent-free matrix applications can reduce this risk, but increase the possibility of ionisation bias due to matrix adhesion to tissue sections. We report here the use of matrix-free MSI using laser desorption ionisation performed on a 12 T Fourier transform ion cyclotron resonance (FTICR) mass spectrometer. We used unprocessed tissue with no post-processing following thaw-mounting on matrix-assisted laser desorption ionisation (MALDI) indium-tin oxide (ITO) target plates. The identification and distribution of a range of phospholipids in mouse brain and kidney sections are presented and compared with previously published MALDI time-of-flight (TOF) MSI distributions. Copyright © 2011 John Wiley & Sons, Ltd. PMID:21416534

Internal damping due to dislocation movements induced by thermal expansion mismatch between matrix and particles in metal matrix composites. [Al/SiC

DOE Office of Scientific and Technical Information (OSTI.GOV)

Girand, C.; Lormand, G.; Fougeres, R.

In metal matrix composites (MMCs), the mechanical 1 of the reinforcement-matrix interface is an important parameter because it governs the load transfer from matrix to particles, from which the mechanical properties of these materials are derived. Therefore, it would be useful to set out an experimental method able to characterize the interface and the adjacent matrix behaviors. Thus, a study has been undertaken by means of internal damping (I.D.) measurements, which are well known to be very sensitive for studying irreversible displacements at the atomic scale. More especially, this investigation is based on the fact that, during cooling of MMC's,more » stress concentrations originating from differences in coefficients of thermal expansion (C.T.E.) of matrix and particles should induce dislocation movements in the matrix surrounding the reinforcement; that is, local microplastic strains occur. Therefore, during I.D. measurements vs temperature these movements should contribute to MMCs I.D. in a process similar to those involved around first order phase transitions in solids. The aim of this paper is to present, in the case of Al/SiC particulate composites, new developments of this approach that has previously led to promising results in the case of Al-Si alloys.« less

Communication-avoiding symmetric-indefinite factorization

DOE PAGES

Ballard, Grey Malone; Becker, Dulcenia; Demmel, James; ...

2014-11-13

We describe and analyze a novel symmetric triangular factorization algorithm. The algorithm is essentially a block version of Aasen's triangular tridiagonalization. It factors a dense symmetric matrix A as the product A=PLTL TP T where P is a permutation matrix, L is lower triangular, and T is block tridiagonal and banded. The algorithm is the first symmetric-indefinite communication-avoiding factorization: it performs an asymptotically optimal amount of communication in a two-level memory hierarchy for almost any cache-line size. Adaptations of the algorithm to parallel computers are likely to be communication efficient as well; one such adaptation has been recently published. Asmore » a result, the current paper describes the algorithm, proves that it is numerically stable, and proves that it is communication optimal.« less

A covariant multiple scattering series for elastic projectile-target scattering

NASA Technical Reports Server (NTRS)

Gross, Franz; Maung-Maung, Khin

1989-01-01

A covariant formulation of the multiple scattering series for the optical potential is presented. The case of a scalar nucleon interacting with a spin zero isospin zero A-body target through meson exchange, is considered. It is shown that a covariant equation for the projectile-target t-matrix can be obtained which sums the ladder and crossed ladder diagrams efficiently. From this equation, a multiple scattering series for the optical potential is derived, and it is shown that in the impulse approximation, the two-body t-matrix associated with the first order optical potential is the one in which one particle is kept on mass-shell. The meaning of various terms in the multiple scattering series is given. The construction of the first-order optical potential for elastic scattering calculations is described.

Communication-avoiding symmetric-indefinite factorization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ballard, Grey Malone; Becker, Dulcenia; Demmel, James

We describe and analyze a novel symmetric triangular factorization algorithm. The algorithm is essentially a block version of Aasen's triangular tridiagonalization. It factors a dense symmetric matrix A as the product A=PLTL TP T where P is a permutation matrix, L is lower triangular, and T is block tridiagonal and banded. The algorithm is the first symmetric-indefinite communication-avoiding factorization: it performs an asymptotically optimal amount of communication in a two-level memory hierarchy for almost any cache-line size. Adaptations of the algorithm to parallel computers are likely to be communication efficient as well; one such adaptation has been recently published. Asmore » a result, the current paper describes the algorithm, proves that it is numerically stable, and proves that it is communication optimal.« less

Comparative test on several forms of background error covariance in 3DVar

NASA Astrophysics Data System (ADS)

Shao, Aimei

2013-04-01

The background error covariance matrix (Hereinafter referred to as B matrix) plays an important role in the three-dimensional variational (3DVar) data assimilation method. However, it is difficult to get B matrix accurately because true atmospheric state is unknown. Therefore, some methods were developed to estimate B matrix (e.g. NMC method, innovation analysis method, recursive filters, and ensemble method such as EnKF). Prior to further development and application of these methods, the function of several B matrixes estimated by these methods in 3Dvar is worth studying and evaluating. For this reason, NCEP reanalysis data and forecast data are used to test the effectiveness of the several B matrixes with VAF (Huang, 1999) method. Here the NCEP analysis is treated as the truth and in this case the forecast error is known. The data from 2006 to 2007 is used as the samples to estimate B matrix and the data in 2008 is used to verify the assimilation effects. The 48h and 24h forecast valid at the same time is used to estimate B matrix with NMC method. B matrix can be represented by a correlation part (a non-diagonal matrix) and a variance part (a diagonal matrix of variances). Gaussian filter function as an approximate approach is used to represent the variation of correlation coefficients with distance in numerous 3DVar systems. On the basis of the assumption, the following several forms of B matrixes are designed and test with VAF in the comparative experiments: (1) error variance and the characteristic lengths are fixed and setted to their mean value averaged over the analysis domain; (2) similar to (1), but the mean characteristic lengths reduce to 50 percent for the height and 60 percent for the temperature of the original; (3) similar to (2), but error variance calculated directly by the historical data is space-dependent; (4) error variance and characteristic lengths are all calculated directly by the historical data; (5) B matrix is estimated directly by the historical data; (6) similar to (5), but a localization process is performed; (7) B matrix is estimated by NMC method but error variance is reduced by 1.7 times in order that the value is close to that calculated from the true forecast error samples; (8) similar to (7), but the localization similar to (6) is performed. Experimental results with the different B matrixes show that for the Gaussian-type B matrix the characteristic lengths calculated from the true error samples don't bring a good analysis results. However, the reduced characteristic lengths (about half of the original one) can lead to a good analysis. If the B matrix estimated directly from the historical data is used in 3DVar, the assimilation effect can not reach to the best. The better assimilation results are generated with the application of reduced characteristic length and localization. Even so, it hasn't obvious advantage compared with Gaussian-type B matrix with the optimal characteristic length. It implies that the Gaussian-type B matrix, widely used for operational 3DVar system, can get a good analysis with the appropriate characteristic lengths. The crucial problem is how to determine the appropriate characteristic lengths. (This work is supported by the National Natural Science Foundation of China (41275102, 40875063), and the Fundamental Research Funds for the Central Universities (lzujbky-2010-9) )

A novel fibrin-based artificial ovary prototype resembling human ovarian tissue in terms of architecture and rigidity.

PubMed

Chiti, Maria Costanza; Dolmans, Marie-Madeleine; Mortiaux, Lucie; Zhuge, Flanco; Ouni, Emna; Shahri, Parinaz Asiabi Kohneh; Van Ruymbeke, Evelyne; Champagne, Sophie-Demoustier; Donnez, Jacques; Amorim, Christiani Andrade

2018-01-01

The aim of this study is to optimize fibrin matrix composition in order to mimic human ovarian tissue architecture for human ovarian follicle encapsulation and grafting. Ultrastructure of fresh human ovarian cortex in age-related women (n = 3) and different fibrin formulations (F12.5/T1, F30/T50, F50/T50, F75/T75), rheology of fibrin matrices and histology of isolated and encapsulated human ovarian follicles in these matrices. Fresh human ovarian cortex showed a highly fibrous and structurally inhomogeneous architecture in three age-related patients, but the mean ± SD of fiber thickness (61.3 to 72.4 nm) was comparable between patients. When the fiber thickness of four different fibrin formulations was compared with human ovarian cortex, F50/T50 and F75/T75 showed similar fiber diameters to native tissue, while F12.5/T1 was significantly different (p value < 0.01). In addition, increased concentrations of fibrin exhibited enhanced storage modulus with F50/T50, resembling physiological ovarian rigidity. Excluding F12.5/T1 from further analysis, only three remaining fibrin matrices (F30/T50, F50/T50, F75/T75) were histologically investigated. For this, frozen-thawed fragments of human ovarian tissue collected from 22 patients were used to isolate ovarian follicles and encapsulate them in the three fibrin formulations. All three yielded similar follicle recovery and loss rates soon after encapsulation. Therefore, based on fiber thickness, porosity, and rigidity, we selected F50/T50 as the fibrin formulation that best mimics native tissue. Of all the different fibrin matrix concentrations tested, F50/T50 emerged as the combination of choice in terms of ultrastructure and rigidity, most closely resembling human ovarian cortex.

Some properties of the two-body effective interaction in the /sup 208/Pb region

DOE Office of Scientific and Technical Information (OSTI.GOV)

Groleau, R.

The (/sup 3/He,d) and (/sup 4/He,t) single proton transfer reactions on /sup 208/Pb and /sup 209/Bi were studied using 30 and 40 MeV He beams from the Princeton Cyclotron Laboratory. The outgoing d and t were detected by a position sensitive proportional counter in the focal plane of a Q-3D spectrometer. The resolution varied between 10 and 14 keV (FWHM). Using the ratio of the cross-sections for the (/sup 3/He,d) and (/sup 4/He,t) reactions to determine the magnitude of the angular momentum transfers, the spectroscopic factors for the reaction on /sup 209/Bi have been measured relative to the transitions tomore » the single particle states in these reactions on /sup 208/Pb. Sum rules as developed by Bansal and French are used to study the configurations vertical bar h/sub 9/2 x h/sub 9/2/>, vertical bar h/sub 9/2/ x f/sub 7/2/>, vertical bar h/sub 9/2 x i/sub 13/2/>, vertical bar h/sub 9/2/ x f/sub 5/2/>and part of vertical bar h/sub 9/2/ x p/sub 3/2/> and vertical bar h/sub 9/2/ x p/sub 1/2>. Using the linear energy weighted sum rule, the diagonal matrix elements of the effective interaction between valence protons around the /sup 208/Pb core are deduced. The matrix elements obtained from a simple empirical interaction V/sub I//sup T=1/ of a pure Wigner type are compared to the extracted matrix elements. The interaction is characterized by an attractive short-range (0.82j and a repulsive long-range (8.2fm) potential: V/sub I//sup T = 1/ (MeV =-/96 e/sup - (r/0.82) /sup 2// + 0.51 e/sup -(r/8.2)/sup 2/. The core polarization is studied using the experimental static electric quadrupole and magnetic dipole moments of the nuclei in the /sup 208/Pb region. In general, the magnetic moments of multiple valence nucleon nuclei are well predicted by simple rules of Racah algebra. The three and four valence proton spectra (/sup 211/At and /sup 212/Rn) calculated with the experimental two particle matrix elements agree well with the experimental spectra.« less

Transfer matrix spectrum for cyclic representations of the 6-vertex reflection algebra by quantum separation of variables

NASA Astrophysics Data System (ADS)

Pezelier, Baptiste

2018-02-01

In this proceeding, we recall the notion of quantum integrable systems on a lattice and then introduce the Sklyanin’s Separation of Variables method. We sum up the main results for the transfer matrix spectral problem for the cyclic representations of the trigonometric 6-vertex reflection algebra associated to the Bazanov-Stroganov Lax operator. These results apply as well to the spectral analysis of the lattice sine-Gordon model with open boundary conditions. The transfer matrix spectrum (both eigenvalues and eigenstates) is completely characterized in terms of the set of solutions to a discrete system of polynomial equations. We state an equivalent characterization as the set of solutions to a Baxter’s like T-Q functional equation, allowing us to rewrite the transfer matrix eigenstates in an algebraic Bethe ansatz form.

Variational calculation of second-order reduced density matrices by strong N-representability conditions and an accurate semidefinite programming solver.

PubMed

Nakata, Maho; Braams, Bastiaan J; Fujisawa, Katsuki; Fukuda, Mituhiro; Percus, Jerome K; Yamashita, Makoto; Zhao, Zhengji

2008-04-28

The reduced density matrix (RDM) method, which is a variational calculation based on the second-order reduced density matrix, is applied to the ground state energies and the dipole moments for 57 different states of atoms, molecules, and to the ground state energies and the elements of 2-RDM for the Hubbard model. We explore the well-known N-representability conditions (P, Q, and G) together with the more recent and much stronger T1 and T2(') conditions. T2(') condition was recently rederived and it implies T2 condition. Using these N-representability conditions, we can usually calculate correlation energies in percentage ranging from 100% to 101%, whose accuracy is similar to CCSD(T) and even better for high spin states or anion systems where CCSD(T) fails. Highly accurate calculations are carried out by handling equality constraints and/or developing multiple precision arithmetic in the semidefinite programming (SDP) solver. Results show that handling equality constraints correctly improves the accuracy from 0.1 to 0.6 mhartree. Additionally, improvements by replacing T2 condition with T2(') condition are typically of 0.1-0.5 mhartree. The newly developed multiple precision arithmetic version of SDP solver calculates extraordinary accurate energies for the one dimensional Hubbard model and Be atom. It gives at least 16 significant digits for energies, where double precision calculations gives only two to eight digits. It also provides physically meaningful results for the Hubbard model in the high correlation limit.

High-precision half-life measurements of the T =1 /2 mirror β decays 17F and 33Cl

NASA Astrophysics Data System (ADS)

Grinyer, J.; Grinyer, G. F.; Babo, M.; Bouzomita, H.; Chauveau, P.; Delahaye, P.; Dubois, M.; Frigot, R.; Jardin, P.; Leboucher, C.; Maunoury, L.; Seiffert, C.; Thomas, J. C.; Traykov, E.

2015-10-01

Background: Measurements of the f t values for T =1 /2 mirror β+ decays offer a method to test the conserved vector current hypothesis and to determine Vud, the up-down matrix element of the Cabibbo-Kobayashi-Maskawa matrix. In most mirror decays used for these tests, uncertainties in the f t values are dominated by the uncertainties in the half-lives. Purpose: Two precision half-life measurements were performed for the T =1 /2 β+ emitters, 17F and 33Cl, in order to eliminate the half-life as the leading source of uncertainty in their f t values. Method: Half-lives of 17F and 33Cl were determined using β counting of implanted radioactive ion beam samples on a moving tape transport system at the Système de Production d'Ions Radioactifs Accélérés en Ligne low-energy identification station at the Grand Accélérateur National d'Ions Lourds. Results: The 17F half-life result, 64.347 (35) s, precise to ±0.05 % , is a factor of 5 times more precise than the previous world average. The half-life of 33Cl was determined to be 2.5038 (22) s. The current precision of ±0.09 % is nearly 2 times more precise compared to the previous world average. Conclusions: The precision achieved during the present measurements implies that the half-life no longer dominates the uncertainty of the f t values for both T =1 /2 mirror decays 17F and 33Cl.

Diagonalization of transfer matrix of supersymmetry U{sub q}(sl-caret(M+1|N+1)) chain with a boundary

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kojima, Takeo

2013-04-15

We study the supersymmetry U{sub q}(sl-caret(M+1|N+1)) analogue of the supersymmetric t-J model with a boundary. Our approach is based on the algebraic analysis method of solvable lattice models. We diagonalize the commuting transfer matrix by using the bosonizations of the vertex operators associated with the quantum affine supersymmetry U{sub q}(sl-caret(M+1|N+1)).

Comparative matrix isolation infrared spectroscopy study of 1,3- and 1,4-diene monoterpenes (α-phellandrene and γ-terpinene).

PubMed

Marzec, K M; Reva, I; Fausto, R; Proniewicz, L M

2011-05-05

In the present work, γ-terpinene (a 1,4-diene derivative) and α-phellandrene (1,3-diene derivative) were isolated in cryogenic argon matrices and their structures, vibrational spectra, and photochemistries were characterized with the aid of FTIR spectroscopy and quantum chemical calculations performed at the DFT/B3LYP/6-311++G(d,p) level of approximation. The molecules bear one conformationally relevant internal rotation axis, corresponding to the rotation of the isopropyl group. The calculations provide evidence of three minima on the potential energy surfaces of the studied molecules, where the isopropyl group assumes the trans, gauche+, and gauche- conformations (T, G+, G-). The signatures of all these conformers were identified in the experimental matrix infrared spectra, with the T forms dominating, in agreement with the theoretical predicted abundances in gas phase at room temperature. In situ UV (λ > 200 nm) irradiation of matrix-isolated α-phellandrene led to its isomerization into an open-ring species. The photoproduct was found to exhibit the ZE configuration of its backbone, which to be formed from the reactant molecule does not require extensive structural rearrangements of both the reagent and matrix. γ-Terpinene was photostable when subjected to irradiation under the same experimental conditions. In addition, the liquid compounds at room temperature were also investigated by FTIR-ATR and FT-Raman spectroscopies.

Fixed Point Problems for Linear Transformations on Pythagorean Triples

ERIC Educational Resources Information Center

Zhan, M.-Q.; Tong, J.-C.; Braza, P.

2006-01-01

In this article, an attempt is made to find all linear transformations that map a standard Pythagorean triple (a Pythagorean triple [x y z][superscript T] with y being even) into a standard Pythagorean triple, which have [3 4 5][superscript T] as their fixed point. All such transformations form a monoid S* under matrix product. It is found that S*…

Characterization of erosion of metallic materials under cavitation attack in a mineral oil

NASA Technical Reports Server (NTRS)

Rao, B. C. S.; Buckley, D. H.

1984-01-01

Cavitation erosion and erosion rates of eight metallic materials representing three crystal structures were studied using a 20-kHz ultrasonic magnetostrictive oscillator in viscous mineral oil. The erosion rates of the metals with an fcc matrix were 10 to 100 times higher than that of an hcp-matrix titanium alloy. The erosion rates of iron and molybdenum, with bcc matrices, were higher than that of the titanium alloy but lower than those of the fcc metals. Scanning electron microscopy indicates that the cavitation pits are initially formed at the grain boundaries and precipitates and that the pits that formed at the triple points grew faster than the others. Transcrystalline craters formed by cavitation attack over the surface of grains and roughened the surfaces by multiple slip and twinning. Surface roughness measurements show that the pits that formed over the grain boundaries deepended faster than other pits. Computer analysis revealed that a geometric expression describes the nondimensional erosion curves during the time period 0.5 t(0) t 2.5 t(0), where t(0) is the incubation period. The fcc metals had very short incubation periods; the titanium alloy had the longest incubation period.

Alkaline saponification results in decomposition of tocopherols in milk and ovine blood plasma.

PubMed

Czauderna, M; Kowalczyk, J

2007-10-15

Alkaline saponification of entire sample matrixes for quantification of alpha-, gamma-, delta-tocopherols (alpha-T, gamma-T, delta-T) and alpha-tocopherol acetate (alpha-TAc) was examined. High-performance liquid chromatography was used to measure alpha-T, gamma-T, delta-T and alpha-TAc in tocopherol standard solutions, milk and ovine blood plasma. Saponification in the presence of vitamin C decreases the concentration of tocopherols, especially alpha-T and gamma-T. The poor recovery of tocopherols is due to the decomposition of tocopherols in saponified standard solutions, milk or plasma. Saponification of samples in the presence of 2,[6]-ditertbutyl-p-cresol or flushed only with a stream of Ar resulted in a major decrease in the concentrations of alpha-T, gamma-T, delta-T and alpha-TAc in comparison with saponification in the presence of vitamin C.

A new bidirectional generalization of (2+1)-dimensional matrix k-constrained Kadomtsev-Petviashvili hierarchy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chvartatskyi, O. I., E-mail: alex.chvartatskyy@gmail.com; Sydorenko, Yu. M., E-mail: y-sydorenko@franko.lviv.ua

We introduce a new bidirectional generalization of (2+1)-dimensional k-constrained Kadomtsev-Petviashvili (KP) hierarchy ((2+1)-BDk-cKPH). This new hierarchy generalizes (2+1)-dimensional k-cKP hierarchy, (t{sub A}, τ{sub B}) and (γ{sub A}, σ{sub B}) matrix hierarchies. (2+1)-BDk-cKPH contains a new matrix (1+1)-k-constrained KP hierarchy. Some members of (2+1)-BDk-cKPH are also listed. In particular, it contains matrix generalizations of Davey-Stewartson (DS) systems, (2+1)-dimensional modified Korteweg-de Vries equation and the Nizhnik equation. (2+1)-BDk-cKPH also includes new matrix (2+1)-dimensional generalizations of the Yajima-Oikawa and Melnikov systems. Binary Darboux Transformation Dressing Method is also proposed for construction of exact solutions for equations from (2+1)-BDk-cKPH. As an example the exactmore » form of multi-soliton solutions for vector generalization of the DS system is given.« less

Effect of an Mg-rich matrix on the corrosion behavior of As-cast magnesium-aluminum alloys

NASA Astrophysics Data System (ADS)

Lee, Choong Do; Kang, Choon Sik; Shin, Kwang Seon

2000-10-01

In the present study, the corrosion behavior of as-cast Mg-Al and Mg-Al-Zn alloys was studied as a function of the Al content in the matrix. Corrosion properties such as the corrosion rate, corrosion potential, and repassivation tendency were estimated through immersion and electrochemical tests. The corrosion potential and corrosion rate of a solutionized alloy depend mainly on the Al content of the as-cast alloy. The variation of Al content in the Mg-rich matrix influences the stability of the passive film and the repassivation tendency, i.e., as the Al content of the matrix increases, the repassivation tendency of the surface protective film after its breakage deteriorates. Also, it was proven that the enhancement of corrosion resistance by heat treatment, as in T6, is due to the decrease of solute concentration in the matrix, in addition to the effect of the precipitate, which plays the role of a barrier against corrosion.

Dynamic heterogeneities and non-Gaussian behavior in two-dimensional randomly confined colloidal fluids

NASA Astrophysics Data System (ADS)

Schnyder, Simon K.; Skinner, Thomas O. E.; Thorneywork, Alice L.; Aarts, Dirk G. A. L.; Horbach, Jürgen; Dullens, Roel P. A.

2017-03-01

A binary mixture of superparamagnetic colloidal particles is confined between glass plates such that the large particles become fixed and provide a two-dimensional disordered matrix for the still mobile small particles, which form a fluid. By varying fluid and matrix area fractions and tuning the interactions between the superparamagnetic particles via an external magnetic field, different regions of the state diagram are explored. The mobile particles exhibit delocalized dynamics at small matrix area fractions and localized motion at high matrix area fractions, and the localization transition is rounded by the soft interactions [T. O. E. Skinner et al., Phys. Rev. Lett. 111, 128301 (2013), 10.1103/PhysRevLett.111.128301]. Expanding on previous work, we find the dynamics of the tracers to be strongly heterogeneous and show that molecular dynamics simulations of an ideal gas confined in a fixed matrix exhibit similar behavior. The simulations show how these soft interactions make the dynamics more heterogeneous compared to the disordered Lorentz gas and lead to strong non-Gaussian fluctuations.

Understanding the Mechanisms Through Which Matrix Metalloproteinases (MMPs) Contribute to Breast Cancer-Associated Osteolytic Lesions

DTIC Science & Technology

2009-03-01

Acuff, H. B., Martin, M. D., Kawai, N., Singh , R. K., Vargo-Gogola, T. C., Begtrup, J. L., Peterson, T. E., Fingleton, B., et al. (2005). MMP-7...factor alpha convertase. Journal Biological Chemistry 276, 14665-14674. Wilson, T. J., Nannuru, K. C., Futakuchi, M., Sadanandam, A., and Singh , R. K...tumor cell line (16) was kindly provided by Dr. Swati Biswas of the Vanderbilt Center for Bone Biology. All reagents were obtained from Sigma-Aldrich

The Bottlenose Dolphin (Tursiops truncatus) as a Model to Understand Variation in Stress and Reproductive Hormone Measures in Relation to Sampling Matrix, Demographics, and Environmental Factors

DTIC Science & Technology

2012-09-30

and free- ranging individuals support the existence of these same stress response pathways in marine mammals. While the HPA axis and physiological ... aldosterone , thyroid and reproductive hormones) have been routinely measured in blood as part of the health assessment which also includes a complete...was developed during the workshop held in late-August. For all stress-related hormones (cortisol, aldosterone , T3, T4, and Free T4), correlational

The Bottlenose Dolphin (Tursiops truncatus) as a Model to Understand Variation in Stress and Reproductive Hormone Measures in Relation to Sampling Matrix, Demographics, and Environmental Factors

DTIC Science & Technology

2012-09-30

support the existence of these same stress response pathways in marine mammals. While the HPA axis and physiological processes driven by the GCs are...characterization of stress and stressors, provides unique opportunities to address questions related to stress. Serum hormones (cortisol, aldosterone , thyroid...during the workshop held in late-August. For all stress-related hormones (cortisol, aldosterone , T3, T4, and Free T4), correlational tests and

Longitudinal documentation of serum cartilage oligomeric matrix protein and patient reported outcomes in collegiate soccer athletes over the course of an athletic season

PubMed Central

Hoch, Johanna M.; Mattacola, Carl G.; Bush, HeatherM.; McKeon, Jennifer Medina; Hewett, Timothy E.; Lattermann, Christian

2013-01-01

Background Serum cartilage oligomeric matrix protein (sCOMP) is a biomarker for cartilage degradation. Patient reported outcomes (PRO) are used to document post-injury recovery and may be used to prospectively identify changes in the course of a season. It is unknown what effect intense, continuous physical activity has on sCOMP levels and PRO values in athletes over the duration of a soccer season. Hypothesis/Purpose The purpose of this study was to longitudinally document sCOMP levels, and to determine if changes in PROs occur in collegiate soccer athletes during a season. The hypotheses tested were that sCOMP levels and PRO scores would remain stable over the duration of the spring soccer season. Study Design Case series; Level of evidence, 4. Methods 29 NCAA Division-I soccer athletes (18 males, 11 females, age:19.6±1.2 years, height:177.8±7.4cm, mass:73.8±10.2kg) participated in three[pre-(T1), mid-(T2), and post-season(T3)] data collection sessions. Subjects were included if they participated in the spring soccer season and were free of severe knee injury at the time of data collection. At each session subjects completed PROs (Lysholm, IKDC) before serum collection. Results For sCOMP(ng/mL) there was a significant effect for time with significant increases at T2(1723.5±257.9, p<0.0001) and T3(1624.7±231.6, p=0.002) when compared with T1(1482.9±217.9). For each of the PROs there was a significant effect for time with increases from T1-T2 and T2-T3. Conclusions These data indicate sCOMP levels increased as athletes reported an increased level of function over time. However, the differences in sCOMP levels did not reach the calculated MDC value and the differences in PRO scores did not reach previously calculated MDC values. It is unclear if these increases in sCOMP levels were due to an increase in cartilage matrix breakdown or turnover. Even though these elevations may not be clinically meaningful, this biomarker may have the potential to be used for future research studies investigating the effects of exercise on overall joint health in longitudinal studies. In addition, these results indicate fluctuations in sCOMP occur during a competitive season and must be taken into consideration for future biomarker studies. PMID:22967826

Multisensor Calibration Procedure for an All Weather Short Range Air Defense System Concept.

DTIC Science & Technology

1983-08-15

are then integrated over the rotation interval tF1 - to 1 - tR, to arrive at the following angular displacement mesasuremnts: tF 1 eAl -f WAldt - K~len...g&dt (73) tol to1 tFlAOR1 tj~ 6p’Idt "( 1 8 0 ° " l1 + 0 12 ) (74) tF1 AVAl f Aldt (75) to’ &VB1 tl(6 to1 In order to integrate Al and B1, Reneral...rotation. TFl, TF2 tF1 , tF2 Upper limit of integration during rotation. THTI2,TT13,TRT21 Elments of BCS to ACS transformation THT23,THT311,THT32 matrix

Analysis of the Barrier Properties of Polyimide-Silicate Nanocomposites

NASA Technical Reports Server (NTRS)

Campbell, Sandi; Johnston, J. Chris; Inghram, Linda; McCorkle, Linda; Silverman, Edward

2003-01-01

Montmorillonite clay was organically modified and dispersed into a thermoplastic (BPADA-BAPP) and a thermosetting (PMR-15) polyimide matrix. The barrier properties of the neat resins and the nanocomposites were evaluated. Reductions in gas permeability and water absorption were observed in thermoplastic polyimide nanocomposites. The thermosetting polyimide showed a reduction in weight loss during isothermal aging at 288 C. Carbon fabric (T650-35, 8 HS, 8 ply) composites were prepared using both the BPADE-BAPP and PMR-15 based nanocomposites. Dispersion of the layered silicate in the BPADA-BAPP matrix reduced helium permeability by up to 70 percent. The PMR-15/ silicate nanocomposite matrix had an increase in thermal oxidative stability of up to 25 percent.

Photodissociation dynamics of CH{sub 3}C(O)SH in argon matrix: A QM/MM nonadiabatic dynamics simulation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xia, Shu-Hua; Liu, Xiang-Yang; Fang, Qiu

2015-11-21

In this work, we have first employed the combined quantum mechanics/molecular mechanics (QM/MM) method to study the photodissociation mechanism of thioacetic acid CH{sub 3}C(O)SH in the S{sub 1}, T{sub 1}, and S{sub 0} states in argon matrix. CH{sub 3}C(O)SH is treated quantum mechanically using the complete active space self-consistent field and complete active space second-order perturbation theory methods; argon matrix is described classically using Lennard-Jones potentials. We find that the C-S bond fission is predominant due to its small barriers of ca. 3.0 and 1.0 kcal/mol in the S{sub 1} and T{sub 1} states. It completely suppresses the nearby C—Cmore » bond fission. After the bond fission, the S{sub 1} radical pair of CH{sub 3}CO and SH can decay to the S{sub 0} and T{sub 1} states via internal conversion and intersystem crossing, respectively. In the S{sub 0} state, the radical pair can either recombine to form CH{sub 3}C(O)SH or proceed to form molecular products of CH{sub 2}CO and H{sub 2}S. We have further employed our recently developed QM/MM generalized trajectory-based surface-hopping method to simulate the photodissociation dynamics of CH{sub 3}C(O)SH. In 1 ps dynamics simulation, 56% trajectories stay at the Franck-Condon region; the S{sub 1} C—S bond fission takes place in the remaining 44% trajectories. Among all nonadiabatic transitions, the S{sub 1} → S{sub 0} internal conversion is major (55%) but the S{sub 1} → T{sub 1} intersystem crossing is still comparable and cannot be ignored, which accounts for 28%. Finally, we have found a radical channel generating the molecular products of CH{sub 2}CO and H{sub 2}S, which is complementary to the concerted molecular channel. The present work sets the stage for simulating photodissociation dynamics of similar thio-carbonyl systems in matrix.« less

Corrosion of Continuous Fiber Reinforced Aluminum Metal Matrix Composites (CF-AMCs)

NASA Astrophysics Data System (ADS)

Tiwari, Shruti

The first objective of this research is to study the atmospheric corrosion behavior of continuous reinforced aluminum matrix composites (CF-AMCs). The materials used for this research were alumina (Al2O3) and nickel (Ni) coated carbon (C) fibers reinforced AMCs. The major focus is to identify the correlation between atmospheric parameters and the corrosion rates of CF-AMCs in the multitude of microclimates and environments in Hawai'i. The micro-structures of CF-AMCs were obtained to correlate the microstructures with their corrosion performances. Also electrochemical polarization experiments were conducted in the laboratory to explain the corrosion mechanism of CF-AMCs. In addition, CF-AMCs were exposed to seven different test sites for three exposure periods. The various climatic conditions like temperature (T), relative humidity (RH), rainfall (RF), time of wetness (TOW), chloride (Cl- ) and sulfate (SO42-) deposition rate, and pH were monitored for three exposure period. Likewise, mass losses of CF-AMCs at each test site for three exposure periods were determined. The microstructure of the CF-AMCS showed that Al/C/50f MMCs contained a Ni-rich phase in the matrix, indicating that the Ni coating on the C fiber dissolved in the matrix. The intermetallic phases obtained in Al-2wt% Cu/Al 2O3/50f-T6 MMC and Al-2wt%-T6 monolith were rich in Cu and Fe. The intermetallic phases obtained in Al 7075/Al2O3/50f-T6 MMC and Al 7075-T6 monolith also contained traces of Mg, Zn, Ni, and Si. Electrochemical polarization experiment indicated that the Al/Al 2O3/50f Al-2wt% Cu/Al2O3/50f-T6 and Al 7075/Al2O3/50f-T6 MMC showed similar corrosion trends as their respective monoliths pure Al, Al-2wt%-T6 and Al 7075-T6 in both aerated and deaerated condition. Al2O3 fiber, being an insulator, did not have a great effect on the polarization behavior of the composites. Al/C/50f MMCs corroded at a much faster rate as compared to pure Al monolith due to the galvanic effect between C and Al. According to the mass loss data of Al/C/50f MMCs, corrosion rate was high at marine environments (high Cl-) when compared to a tropical rainforest microclimate and low in a test site with a high SO2 and acid rain. Due to presence of conductive C fiber, the galvanic corrosion was a dominating corrosion mechanism. Due to high volume fraction of C, the corrosion phenomenon was cathodically controlled. The galvanic corrosion between C fiber and Al matrix showed a strong positive correlation with Cl - deposition rate. Lower corrosion rate at volcanic test site was attributed to dissolution of Ni rich phase, a potential cathodic site that promotes corrosion of Al/C/50f MMCs. Based on the mass loss data of Al2O3 based CF-AMCs and the monoliths showed maximum corrosion at volcanic test site when compared to any other test site. Due to the small volume fraction of intermetallic phases, the corrosion was anodically controlled. And hence the maximum anodic dissolution was found at volcanic test site (high SO2 and acid rain). The second objective of this thesis is to study the effect localized deformation on the corrosion of CF-AMCs. Corrosion initiation on Al (2 wt% Cu)/Al2O3/60f (60% fiber), Al 6061/Al2O 3/60f, and Al/Al2O3/60f CF-AMCs was studied in an aqueous environment The CF-AMCs and their monolithic alloys were deformed locally using a 1/16" diameter silicon nitride ball and 15-60 Kg load in a Rockwell hardness testing machine. Corrosion initiated at the deformed sites, and after longer exposures, spread over the entire region. Localized mechanical deformation resulted in micro-crevice formations at the fiber matrix interface. When deformed material is exposed to a corrosive solution, the crevices at the fiber matrix interface likely increased the hydrogen ion concentration lowering the pH at those regions, a process that leads to premature corrosion. The copper (Cu) rich CF-AMCs in aqueous solution resulted in dissolution of Cu rich phase and their subsequent deposition and redistribution as Cu over the deformed CF-AMCs surface. The corrosion rates of deformed CF-AMCs were higher than the non-deformed CF-AMCs.

Stromal Tissue Rigidity Promotes Mesenchymal Stem Cell-Mediated Corneal Wound Healing Through the Transforming Growth Factor β Signaling Pathway.

PubMed

Yang, Yun-Hsiang; Hsieh, Ting-Lieh; Ji, Andrea Tung-Qian; Hsu, Wei-Tse; Liu, Chia-Yu; Lee, Oscar Kuang-Sheng; Ho, Jennifer Hui-Chun

2016-10-01

The healing of a corneal epithelial defect is essential for preventing infectious corneal ulcers and subsequent blindness. We previously demonstrated that mesenchymal stem cells (MSCs) in the corneal stroma, through a paracrine mechanism, yield a more favorable therapeutic benefit for corneal wound re-epithelialization than do MSCs in the corneal epithelium. In this study, MSCs were grown on a matrix with the rigidity of the physiological human vitreous (1 kPa), corneal epithelium (8 kPa), or corneal stroma (25 kPa) for investigating the role of corneal tissue rigidity in MSC functions regarding re-epithelialization promotion. MSC growth on a 25-kPa dish significantly promoted the wound healing of human corneal epithelial (HCE-T) cells. Among growth factors contributing to corneal epithelial wound healing, corneal stromal rigidity selectively enhanced transforming growth factor-beta (TGF-β) secretion from MSCs. Inhibitors of TGF-β pan receptor, TGF-β receptor 1, and Smad2 dose dependently abrogated MSC-mediated HCE-T wound healing. Furthermore, MSCs growth on a matrix with corneal stromal rigidity enhanced the ability of themselves to promote corneal re-epithelialization by activating matrix metalloproteinase (MMP) expression and integrin β1 production in HCE-T cells through TGF-β signaling pathway activation. Smad2 activation resulted in the upregulation of MMP-2 and -13 expression in HCE-T cells, whereas integrin β1 production favored a Smad2-independent TGF-β pathway. Altogether, we conclude that corneal stromal rigidity is a critical factor for MSC-induced promotion of corneal re-epithelialization. The activation of the TGF-β signaling pathway, which maintains the balance between integrin and MMP expression, in HCE-T cells is the major pathway responsible for MSC-mediated wound healing. Stem Cells 2016;34:2525-2535. © 2016 AlphaMed Press.

Infrared Matrix-Isolation Study of New Noble-Gas Compounds

NASA Astrophysics Data System (ADS)

Zhu, Cheng; Räsänen, Markku; Khriachtchev, Leonid

2016-06-01

We identify new noble-gas compounds in solid matrices using IR spectroscopy. The compounds under study belong to two types: HNgY and YNgY' where Ng is a noble-gas atom and Y and Y' are electronegative fragments. The experimental assignments are supported by ab initio calculations at the MP2(full) and CCSD(T) levels of theory with the def2-TZVPPD basis set. We have prepared and characterized two new HNgY compounds (noble-gas hydrides): HKrCCCl in a Kr matrix and HXeCCCl in a Xe matrix.I The synthesis of these compounds includes two steps: UV photolysis of HCCCl in a noble-gas matrix to form the H + CCCl fragments and annealing of the matrix to mobilize H atoms and to promote the H + Ng + CCCl = HNgCCCl reaction. An interesting observation in the experiments on HXeCCCl in a Xe matrix is the temperature-induced transformation of the three H-Xe stretching bands. This observation is explained by temperature-induced changes of local matrix morphology around the embedded HXeCCCl molecule. In these experiments, we have also obtained the IR spectrum of the CCCl radical, which is produced by photodecomposition of HCCCl. We have identified three new YNgY' compounds (fluorinated noble-gas cyanides): FKrCN in a Kr matrix and FXeCN and FXeNC in a Xe matrix.II These molecule are formed by photolysis of FCN in a noble-gas matrix due to locality of this process. The amount of these molecules increases upon thermal mobilization of the F atoms in the photolyzed matrix featuring the F + Ng + CN reaction.

Proceedings of Damping 󈨟, Held in San Diego, California on 13 - 15 February 1991. Volume 3

DTIC Science & Technology

1991-08-01

Characteristics of Metal Matrix Ccomposites, Letter Report , Martin Marietta , Denver, CO, Report no. MCR -85-721, Issue 9, 1988. 23. J.A. DiCarlo and J.E. Maisel...MIT, December 1983. 2. S.P. Rawal, T.H. Armstrong, and M.S. Misra, Interfaces and Damping in Metal Matrx Composites, Final Report , Martin Marietta ... Report , Martin Marietta Denver Aerospace, Denver, Co, November 4. I.E. Schoutens, Internal Damping in Metal Matrix Composites, MMCIAC, Kaman Sciences

Defects in Ceramic Matrix Composites and Their Impact on Elastic Properties (Postprint)

DTIC Science & Technology

2013-07-01

numerically modeled. The composite under investigation was a 10 layer T300 carbon/ SiC composite in which carbon fabric was impregnated using a polymer ...fraction. (3) Melt Infiltrated in situ BN SiC / SiC composite comprising a stochiometric SiC (Sylramic™) fiber, with an in situ boron nitride treatment...SiNC composite is listed in Table 4. Polymer derived SiC and SiNC matrix material do not ex- hibit a major change in their elastic properties at

Interfacial Studies of Refractory Glass-Ceramic Matrix/Advanced SiC fiber Reinforced Composites

DTIC Science & Technology

1991-04-30

Prepared by J. J. Brennan ANNUAL REPORT Contract N0001 4-87-C-0699 for Department of the Navy Office of Naval Research Arlington, VA 22217 April 30, 1991...1 30 April1991 I Annual 1 Feb 1990 -1 Feb 1991 4. TITLE AND SUBTITLE 5. FUNDING NUMBERS INTERFACIAL STUDIES OF REFRACTORY GLASS-CERAMIC MATRIX...composites were very similar for either Lox M Tyranno or NICALON fiber reinforcement. 14. SUBJECT TERMS IS. NUMBER OF PA~t; Crystalline SiC fibers

Entropy generation, particle creation, and quantum field theory in a cosmological spacetime: When do number and entropy increase\\?

NASA Astrophysics Data System (ADS)

Kandrup, Henry E.

1988-06-01

This paper reexamines the statistical quantum field theory of a free, minimally coupled, real scalar field Φ in a statically bounded, classical Friedmann cosmology, where the time-dependent scale factor Ω(t) tends to constant values Ω1 and Ω2 for tt2. The principal objective is to investigate the intuition that ``entropy'' S correlates with average particle number , so that increases in induced by parametric amplification manifest a one-to-one connection with increases in S. The definition of particle number Nk becomes unambiguous for t>t2 and t- is guaranteed generically to be positive only for special initial data which, in a number representation, are characterized by ``random phases'' in the sense that any relative phase for the projection of ρ(t1) into two different number eigenstates is ``random'' or ``unobservable physically,'' and averaged over in a density matrix. More importantly for the notion of entropy, random-phase initial data also guarantee an increase in the spread of P(\\{k,Nk\\}), so that, e.g., the sum of the variances Δ2N+/-k(t2) exceeds the initial Δ2N+/-k(t1). It is this increasing spread in P, rather than the growth in average numbers per se, which suggests that, for initial data manifesting random phases, SN(t2)>SN(t1), a result established rigorously in the limits of strong and weak particle creation.

Metamorphic evolution and geochronology of the Dunhuang orogenic belt in the Hongliuxia area, northwestern China

NASA Astrophysics Data System (ADS)

Wang, Hao Y. C.; Wang, Juan; Wang, Guo-Dong; Lu, Jun-Sheng; Chen, Hong-Xu; Peng, Tao; Zhang, Hui C. G.; Zhang, Qian W. L.; Xiao, Wen-Jiao; Hou, Quan-Lin; Yan, Quan-Ren; Zhang, Qing; Wu, Chun-Ming

2017-03-01

Garnet-bearing mafic granulites and amphibolites from the Hongliuxia area of the southern Dunhuang orogenic belt, northwestern China, commonly occur as lenses or boudinages enclosed within metapelite or marble, which represent the block-in-matrix feature typical of orogenic mélange. Three to four generations of metamorphic mineral assemblages are preserved in these rocks. In the high-pressure amphibolites, prograde mineral assemblages (M1) occur as inclusions (hornblende + plagioclase + quartz ± chlorite ± epidote ± ilmenite) preserved within garnet porphyroblasts, and formed at 550-590 °C and 7.7-9.2 kbar based on geothermobarometry. The metamorphic peak mineral assemblages (M2) are composed of garnet + hornblende + plagioclase + quartz + clinopyroxene, as well as titanite + zircon + rutile + apatite as accessory minerals in the matrix, and are estimated to have formed at 640-720 °C and 14.1-16.0 kbar. The first retrograde assemblages (M3) are characterized by "white-eye socket" symplectites (hornblende + plagioclase + quartz ± biotite ± epidote ± magnetite) rimming garnet porphyroblasts, which formed at the expense of the garnet rims and adjacent matrix minerals during the decompression stage under P-T conditions of 610-630 °C and 5.6-11.8 kbar. The second retrograde assemblages (M4) are intergrowths of actinolite and worm-like quartz produced by the breakdown of the matrix hornblendes, and formed under P-T conditions of ∼490 °C and ∼2.8 kbar. For the high-pressure mafic granulites, the prograde assemblages (M1) are represented by plagioclase + quartz preserved within the garnet porphyroblasts. The metamorphic peak assemblages (M2) are garnet + matrix minerals (clinopyroxene + plagioclase + quartz + hornblende + rutile + zircon) and were estimated to have formed at ∼680 °C and ∼15.4 kbar. The retrograde assemblages (M3) are characterized by fine-grained patches of hornblende + plagioclase + quartz rimming the garnet porphyroblasts, as well as hornblende rimming clinopyroxene in the matrix, and were inferred to have formed at ∼620 °C and ∼4.2 kbar. For the metapelitic gneiss, the metamorphic peak assemblages are the garnet porphyroblasts plus the matrix minerals (biotite + plagioclase + quartz + ilmenite + zircon), which were estimated to have formed at ∼630 °C and ∼8.9 kbar. The mafic granulites and amphibolites record fairly similar clockwise P-T paths that include nearly isothermal decompression processes, which suggest that they experienced subduction and subsequent rapid tectonic exhumation. SIMS and LA-ICP-MS U-Pb dating of zircons and 40Ar/39Ar dating of hornblende suggest that the metamorphism occurred at ∼430-390 Ma. Field occurrences, different protolith ages of the mafic granulites and amphibolites, and the considerable gap in peak P-T conditions between the amphibolite and mafic granulite boudinages and their country rock may suggest a mélange accumulation process during the Paleozoic caused by the Silurian-Devonian orogeny, which is possibly associated with the closure of the Liuyuan ocean, a branch of the Paleo-Asian ocean near the southern Central Asian Orogenic Belt.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liuyun, Jiang, E-mail: jlytxg@163.com; Chengdong, Xiong; Lixin, Jiang

Graphical abstract: Effect of n-HA content on the isothermal crystallization, morphology and mechanical property of n-HA/PLGA composites was studied in details. The results showed that the addition of higher content of g-n-HA was favorable to promote the crystallization better in g-n-HA/PLGA composites, but it could also cause more agglomeration in PLGA matrix, as a result of worse mechanical properties, and the addition content of 3 wt% g-n-HA to PLGA matrix was an appropriate proportion, which had the highest bending strength among these g-n-HA/PLGA composites, and it might be potential to be used in biomedical fields in future. Highlights: ► Themore » effect of n-HA content on the n-HA/PLGA composites was studied in detail. ► Isothermal crystallization, microstructure and mechanical property were studied. ► The relation between n-HA content and properties of n-HA/PLGA composite was found. ► An appropriate proportion of n-HA in n-HA/PLGA composite was obtained. - Abstract: A serials of g-n-HA/PLGA composites with surface-modified g-n-HA of 1%, 3%, 6%, 10% and 15% in weight were prepared by solution mixing. The isothermal crystallization, morphology and mechanical property of g-n-HA/PLGA composites were investigated by differential scanning calorimeter (DSC), scanning electron microscope (SEM) and electromechanical universal tester. The results showed that Avrami equation was suitable for describing the isothermal crystallization process in this system, and the crystallization rate of g-n-HA/PLGA composites containing more than 3 wt% g-n-HA was basically accord with the relational expression of T{sub 110} {sub °C} > T{sub 105°C} > T{sub 115°C} > T{sub 120°C}. Moreover, at the same Tc, crystallization rate was greatly enhanced with the increasing of g-n-HA acting as nucleate. However, the addition of higher content of g-n-HA would cause more agglomeration in PLGA matrix, so that the mechanical properties of g-n-HA/PLGA composites would gradually decrease. In conclusion, the addition of higher content of g-n-HA was favorable to promote the crystallization better in g-n-HA/PLGA composites, but it could also cause more agglomeration in PLGA matrix, result in worse mechanical properties, and the addition content of 3 wt% g-n-HA to PLGA matrix was an appropriate proportion, which had the highest bending strength among these g-n-HA/PLGA composites, and it might be potential to be used in biomedical fields in future.« less

Carbon Fibre Reinforced Aluminum Matrix Composites, A Critical Review (Les Materiaux Composites a Matrice d’Aluminum Renforcee de Fibres de Carbone, Une Critique),

DTIC Science & Technology

1984-06-01

M.K. ibid., pp. 420-442. Alekhin, V.P. * aateva.., S.M. Fedorov, V.B. Chernyshova , T.A. --. 16. Kim, W.H. ibid., pp. 487-505. Koczak, M.J. Lawley, A...International Conference on Composite Chernyshova , T.A. Materials, Japan Society for Composite Materials, Tokyo, Japan, Kobeleva, L.I. October 1982

Singularity Avoidance Strategies For Satellite Mounted Manipulators Using Attitude Control

DTIC Science & Technology

1998-05-01

raised concerns about these methods by noting the existence of dynamic singularities—SMM configura- tions where the GJM is rank deficient . They showed...form as, V = ejKi 9 T J- TK2J~ l lj-J~ TK2 j L \\J T - K2J~ l K2 Kiei 9 -xTBx (210) (211) The definiteness of the symmetric matrix B in

Off-shell single-top production at NLO matched to parton showers

DOE PAGES

Frederix, R.; Frixione, S.; Papanastasiou, A. S.; ...

2016-06-06

We study the hadroproduction of a Wb pair in association with a light jet, focusing on the dominant t-channel contribution and including exactly at the matrix-element level all non-resonant and off-shell effects induced by the finite top-quark width. Our simulations are accurate to the next-to-leading order in QCD, and are matched to the Herwig6 and Pythia8 parton showers through the MC@NLO method. We present phenomenological results relevant to the 8 TeV LHC, and carry out a thorough comparison to the case of on-shell t-channel single-top production. Furthermore, we formulate our approach so that it can be applied to the generalmore » case of matrix elements that feature coloured intermediate resonances and are matched to parton showers.« less

$$t\\bar{t}$$ Spin Correlations at D0

DOE Office of Scientific and Technical Information (OSTI.GOV)

Peters, Yvonne

2013-01-01

The heaviest known elementary particle today, the top quark, has been discovered in 1995 by the CDF and D0 collaborations at the Tevatron collider at Fermilab. Its high mass and short lifetime, shorter than the timescale for hadronization, makes the top quark a special particle to study. Due to the short lifetime, the top quark's spin information is preserved in the decay products. In this article we discuss the studies of ttbar spin correlations at D0, testing the full chain from production to decay. In particular, we present a measurement using angular information and an analysis using a matrix-element basedmore » technique. The application of the matrix-element based technique to the ttbar dilepton and semileponic final state resulted in the first evidence for non-vanishing ttbar spin correlations.« less

Accurate single-scattering simulation of ice cloud using the invariant-imbedding T-matrix method and the physical-geometric optics method

NASA Astrophysics Data System (ADS)

Sun, B.; Yang, P.; Kattawar, G. W.; Zhang, X.

2017-12-01

The ice cloud single-scattering properties can be accurately simulated using the invariant-imbedding T-matrix method (IITM) and the physical-geometric optics method (PGOM). The IITM has been parallelized using the Message Passing Interface (MPI) method to remove the memory limitation so that the IITM can be used to obtain the single-scattering properties of ice clouds for sizes in the geometric optics regime. Furthermore, the results associated with random orientations can be analytically achieved once the T-matrix is given. The PGOM is also parallelized in conjunction with random orientations. The single-scattering properties of a hexagonal prism with height 400 (in units of lambda/2*pi, where lambda is the incident wavelength) and an aspect ratio of 1 (defined as the height over two times of bottom side length) are given by using the parallelized IITM and compared to the counterparts using the parallelized PGOM. The two results are in close agreement. Furthermore, the integrated single-scattering properties, including the asymmetry factor, the extinction cross-section, and the scattering cross-section, are given in a completed size range. The present results show a smooth transition from the exact IITM solution to the approximate PGOM result. Because the calculation of the IITM method has reached the geometric regime, the IITM and the PGOM can be efficiently employed to accurately compute the single-scattering properties of ice cloud in a wide spectral range.

A new numerically stable implementation of the T-matrix method for electromagnetic scattering by spheroidal particles

NASA Astrophysics Data System (ADS)

Somerville, W. R. C.; Auguié, B.; Le Ru, E. C.

2013-07-01

We propose, describe, and demonstrate a new numerically stable implementation of the extended boundary-condition method (EBCM) to compute the T-matrix for electromagnetic scattering by spheroidal particles. Our approach relies on the fact that for many of the EBCM integrals in the special case of spheroids, a leading part of the integrand integrates exactly to zero, which causes catastrophic loss of precision in numerical computations. This feature was in fact first pointed out by Waterman in the context of acoustic scattering and electromagnetic scattering by infinite cylinders. We have recently studied it in detail in the case of electromagnetic scattering by particles. Based on this study, the principle of our new implementation is therefore to compute all the integrands without the problematic part to avoid the primary cause of loss of precision. Particular attention is also given to choosing the algorithms that minimise loss of precision in every step of the method, without compromising on speed. We show that the resulting implementation can efficiently compute in double precision arithmetic the T-matrix and therefore optical properties of spheroidal particles to a high precision, often down to a remarkable accuracy (10-10 relative error), over a wide range of parameters that are typically considered problematic. We discuss examples such as high-aspect ratio metallic nanorods and large size parameter (≈35) dielectric particles, which had been previously modelled only using quadruple-precision arithmetic codes.

Excited states in polydiacetylene chains: A density matrix renormalization group study

NASA Astrophysics Data System (ADS)

Barcza, Gergely; Barford, William; Gebhard, Florian; Legeza, Örs

2013-06-01

We study theoretically polydiacetylene chains diluted in their monomer matrix. We employ the density matrix renormalization group method on finite chains to calculate the ground state and low-lying excitations of the corresponding Peierls-Hubbard-Ohno Hamiltonian which is characterized by the electron transfer amplitude t0 between nearest neighbors, by the electron-phonon coupling constant α, by the Hubbard interaction U, and by the long-range interaction V. We treat the lattice relaxation in the adiabatic limit, i.e., we calculate the polaronic lattice distortions for each excited state. Using chains with up to 102 lattice sites, we can safely perform the extrapolation to the thermodynamic limit for the ground-state energy and conformation, the single-particle gap, and the energies of the singlet exciton, the triplet ground state, and the optical excitation of the triplet ground state. The corresponding gaps are known with high precision from experiments. We determine a coherent parameter set (t0*=2.4eV,α*=3.4eV/Å,U*=6eV,V*=3eV) from a fit of the experimental gap energies to the theoretical values which we obtain for 81 parameter points in the four-dimensional search space (t0,α,U,V). We identify dark in-gap states in the singlet and triplet sectors as seen in experiments. Using a fairly stiff spring constant, the length of our unit cell is about 1% larger than its experimental value.

Association of Common Variants in MMPs with Periodontitis Risk

PubMed Central

Li, Wenyang; Zhu, Ying; Singh, Pradeep; Ajmera, Deepal Haresh; Song, Jinlin

2016-01-01

Background. Matrix metalloproteinases (MMPs) are considered to play an important role during tissue remodeling and extracellular matrix degradation. And functional polymorphisms in MMPs genes have been reported to be associated with the increased risk of periodontitis. Recently, many studies have investigated the association between MMPs polymorphisms and periodontitis risk. However, the results remain inconclusive. In order to quantify the influence of MMPs polymorphisms on the susceptibility to periodontitis, we performed a meta-analysis and systematic review. Results. Overall, this comprehensive meta-analysis included a total of 17 related studies, including 2399 cases and 2002 healthy control subjects. Our results revealed that although studies of the association between MMP-8 −799 C/T variant and the susceptibility to periodontitis have not yielded consistent results, MMP-1 (−1607 1G/2G, −519 A/G, and −422 A/T), MMP-2 (−1575 G/A, −1306 C/T, −790 T/G, and −735 C/T), MMP-3 (−1171 5A/6A), MMP-8 (−381 A/G and +17 C/G), MMP-9 (−1562 C/T and +279 R/Q), and MMP-12 (−357 Asn/Ser), as well as MMP-13 (−77 A/G, 11A/12A) SNPs are not related to periodontitis risk. Conclusions. No association of these common MMPs variants with the susceptibility to periodontitis was found; however, further larger-scale and multiethnic genetic studies on this topic are expected to be conducted to validate our results. PMID:27194818

A space network structure constructed by tetraneedlelike ZnO whiskers supporting boron nitride nanosheets to enhance comprehensive properties of poly(L-lacti acid) scaffolds

PubMed Central

Feng, Pei; Peng, Shuping; Wu, Ping; Gao, Chengde; Huang, Wei; Deng, Youwen; Shuai, Cijun

2016-01-01

In this study, the mechanical strength and modulus of poly(L-lacti acid) (PLLA) scaffolds were enhanced with the mechanical properties of boron nitride nanosheets (BNNSs) and tetraneedlelike ZnO whiskers (T-ZnOw). The adhesion and proliferation of cells were improved as well as osteogenic differentiation of stem cells was increased. Their dispersion statues in PLLA matrix were improved through a space network structure constructed by three-dimensional T-ZnOw supporting two-dimensional BNNSs. The results showed that the compressive strength, modulus and Vickers hardness of the scaffolds with incorporation of 1 wt% BNNSs and 7 wt% T-ZnOw together were about 96.15%, 32.86% and 357.19% higher than that of the PLLA scaffolds, respectively. This might be due to the effect of the pull out and bridging of BNNSs and T-ZnOw as well as the crack deflection, facilitating the formation of effective stress transfer between the reinforcement phases and the matrix. Furthermore, incorporation of BNNSs and T-ZnOw together into PLLA scaffolds was beneficial for attachment and viability of MG-63 cells. More importantly, the scaffolds significantly increased proliferation and promoted osteogenic differentiation of human bone marrow mesenchymal stem cells (hBMSCs). The enhanced mechanical and biological properties provide the potentials of PLLA/BNNSs/T-ZnOw scaffolds for the application into bone tissue engineering. PMID:27629058

Fabrication of 6FDA-durene membrane incorporated with zeolite T and aminosilane grafted zeolite T for CO2/CH4 separation

NASA Astrophysics Data System (ADS)

Jusoh, Norwahyu; Fong Yeong, Yin; Keong Lau, Kok; Shariff, Azmi Mohd

2017-08-01

In the present work, zeolite T and aminosilane grafted zeolite T are embedded into 6FDA-durene polyimide phase for the fabrication of mixed matrix membranes (MMMs). FESEM images demonstrated that the improvement of interfacial adhesion between zeolite and polymer phases in MMM loaded with aminosilane grafted zeolite T was not significant as compared to zeolite T/6FDA-durene MMM. From the gas permeation test, CO2/CH4 selectivity up to 26.4 was achieved using MMM containing aminosilane grafted zeolite T, while MMM loaded with ungrafted zeolite T showed CO2/CH4 selectivity of 19.1. In addition, MMM incorporated with aminosilane grafted zeolite T particles successfully lies on Robeson upper bound 2008, which makes it an attractive candidate for CO2/CH4 separation.

Bioinspired Design of Polycaprolactone Composite Nanofibers as Artificial Bone Extracellular Matrix for Bone Regeneration Application.

PubMed

Gao, Xiang; Song, Jinlin; Zhang, Yancong; Xu, Xiao; Zhang, Siqi; Ji, Ping; Wei, Shicheng

2016-10-07

The design and development of functional biomimetic systems for programmed stem cell response is a field of topical interest. To mimic bone extracellular matrix, we present an innovative strategy for constructing drug-loaded composite nanofibrous scaffolds in this study, which could integrate multiple cues from calcium phosphate mineral, bioactive molecule, and highly ordered fiber topography for the control of stem cell fate. Briefly, inspired by mussel adhesion mechanism, a polydopamine (pDA)-templated nanohydroxyapatite (tHA) was synthesized and then surface-functionalized with bone morphogenetic protein-7-derived peptides via catechol chemistry. Afterward, the resulting peptide-loaded tHA (tHA/pep) particles were blended with polycaprolactone (PCL) solution to fabricate electrospun hybrid nanofibers with random and aligned orientation. Our research demonstrated that the bioactivity of grafted peptides was retained in composite nanofibers. Compared to controls, PCL-tHA/pep composite nanofibers showed improved cytocompatibility. Moreover, the incorporated tHA/pep particles in nanofibers could further facilitate osteogenic differentiation potential of human mesenchymal stem cells (hMSCs). More importantly, the aligned PCL-tHA/pep composite nanofibers showed more osteogenic activity than did randomly oriented counterparts, even under nonosteoinductive conditions, indicating excellent performance of biomimetic design in cell fate decision. After in vivo implantation, the PCL-tHA/pep composite nanofibers with highly ordered structure could significantly promote the regeneration of lamellar-like bones in a rat calvarial critical-sized defect. Accordingly, the presented strategy in our work could be applied for a wide range of potential applications in not only bone regeneration application but also pharmaceutical science.

Association of Nitric Oxide Synthase and Matrix Metalloprotease Single Nucleotide Polymorphisms with Preeclampsia and Its Complications

PubMed Central

Leonardo, Daniela P.; Albuquerque, Dulcinéia M.; Lanaro, Carolina; Baptista, Letícia C.; Cecatti, José G.; Surita, Fernanda G.; Parpinelli, Mary A.; Costa, Fernando F.; Franco-Penteado, Carla F.; Fertrin, Kleber Y.; Costa, Maria Laura

2015-01-01

Background Preeclampsia is one of the leading causes of maternal and neonatal morbidity and mortality in the world, but its appearance is still unpredictable and its pathophysiology has not been entirely elucidated. Genetic studies have associated single nucleotide polymorphisms in genes encoding nitric oxide synthase and matrix metalloproteases with preeclampsia, but the results are largely inconclusive across different populations. Objectives To investigate the association of single nucleotide polymorphisms (SNPs) in NOS3 (G894T, T-786C, and a variable number of tandem repetitions VNTR in intron 4), MMP2 (C-1306T), and MMP9 (C-1562T) genes with preeclampsia in patients from Southeastern Brazil. Methods This prospective case-control study enrolled 77 women with preeclampsia and 266 control pregnant women. Clinical data were collected to assess risk factors and the presence of severe complications, such as eclampsia and HELLP (hemolysis, elevated liver enzymes, and low platelets) syndrome. Results We found a significant association between the single nucleotide polymorphism NOS3 T-786C and preeclampsia, independently from age, height, weight, or the other SNPs studied, and no association was found with the other polymorphisms. Age and history of preeclampsia were also identified as risk factors. The presence of at least one polymorphic allele for NOS3 T-786C was also associated with the occurrence of eclampsia or HELLP syndrome among preeclamptic women. Conclusions Our data support that the NOS3 T-786C SNP is associated with preeclampsia and the severity of its complications. PMID:26317342

Safety and immunogenicity of heterologous prime-boost immunization with viral-vectored malaria vaccines adjuvanted with Matrix-M™.

PubMed

Venkatraman, Navin; Anagnostou, Nicholas; Bliss, Carly; Bowyer, Georgina; Wright, Danny; Lövgren-Bengtsson, Karin; Roberts, Rachel; Poulton, Ian; Lawrie, Alison; Ewer, Katie; V S Hill, Adrian

2017-10-27

The use of viral vectors in heterologous prime-boost regimens to induce potent T cell responses in addition to humoral immunity is a promising vaccination strategy in the fight against malaria. We conducted an open-label, first-in-human, controlled Phase I study evaluating the safety and immunogenicity of Matrix-M adjuvanted vaccination with a chimpanzee adenovirus serotype 63 (ChAd63) prime followed by a modified vaccinia Ankara (MVA) boost eight weeks later, both encoding the malaria ME-TRAP antigenic sequence (a multiple epitope string fused to thrombospondin-related adhesion protein). Twenty-two healthy adults were vaccinated intramuscularly with either ChAd63-MVA ME-TRAP alone (n=6) or adjuvanted with 25μg (n=8) or 50μg (n=8) Matrix-M. Vaccinations appeared to be safe and generally well tolerated, with the majority of local and systemic adverse events being mild in nature. The addition of Matrix-M to the vaccine did not increase local reactogenicity; however, systemic adverse events were reported more frequently by volunteers who received adjuvanted vaccine in comparison to the control group. T cell ELISpot responses peaked at 7-days post boost vaccination with MVA ME-TRAP in all three groups. TRAP-specific IgG responses were highest at 28-days post boost with MVA ME-TRAP in all three groups. There were no differences in cellular and humoral immunogenicity at any of the time points between the control group and the adjuvanted groups. We demonstrate that Matrix-M can be safely used in combination with ChAd63-MVA ME-TRAP heterologous prime-boost immunization without any reduction in cellular or humoral immunogenicity. Clinical Trials Registration NCT01669512. Copyright © 2017 Elsevier Ltd. All rights reserved.

Compression and compaction properties of plasticised high molecular weight hydroxypropylmethylcellulose (HPMC) as a hydrophilic matrix carrier.

PubMed

Hardy, I J; Cook, W G; Melia, C D

2006-03-27

The compression and compaction properties of plasticised high molecular weight USP2208 HPMC were investigated with the aim of improving tablet formation in HPMC matrices. Experiments were conducted on binary polymer-plasticiser mixtures containing 17 wt.% plasticiser, and on a model hydrophilic matrix formulation. A selection of common plasticisers, propylene glycol (PG) glycerol (GLY), dibutyl sebacate (DBS) and triacetin (TRI), were chosen to provide a range of plasticisation efficiencies. T(g) values of binary mixtures determined by Dynamic Mechanical Thermal Analysis (DMTA) were in rank order PG>GLY>DBS>TRI>unplasticised HPMC. Mean yield pressure, strain rate sensitivity (SRS) and plastic compaction energy were measured during the compression process, and matrix properties were monitored by tensile strength and axial expansion post-compression. Compression of HPMC:PG binary mixtures resulted in a marked reduction in mean yield pressure and a significant increase in SRS, suggesting a classical plasticisation of HPMC analogous to that produced by water. The effect of PG was also reflected in matrix properties. At compression pressures below 70 MPa, compacts had greater tensile strength than those from native polymer, and over the range 35 and 70 MPa, lower plastic compaction values showed that less energy was required to produce the compacts. Axial expansion was also reduced. Above 70 MPa tensile strength was limited to 3 MPa. These results suggest a useful improvement of HPMC compaction and matrix properties by PG plasticisation, with lowering of T(g) resulting in improved deformation and internal bonding. These effects were also detectable in the model formulation containing a minimal polymer content for an HPMC matrix. Other plasticisers were largely ineffective, matrix strength was poor and axial expansion high. The hydrophobic plasticisers (DBS, TRI) reduced yield pressure substantially, but were poor plasticisers and showed compaction mechanisms that could be attributed to phase separation. The effect of different plasticisers suggests that the deformation characteristics of this HPMC in the solid state is dominated by hydroxyl mediated bonding, rather than by hydrophobic interactions between methoxyl-rich regions.

Hybrid Composite Cryogenic Tank Structure

NASA Technical Reports Server (NTRS)

DeLay, Thomas

2011-01-01

A hybrid lightweight composite tank has been created using specially designed materials and manufacturing processes. The tank is produced by using a hybrid structure consisting of at least two reinforced composite material systems. The inner composite layer comprises a distinct fiber and resin matrix suitable for cryogenic use that is a braided-sleeve (and/or a filamentwound layer) aramid fiber preform that is placed on a removable mandrel (outfitted with metallic end fittings) and is infused (vacuum-assisted resin transfer molded) with a polyurethane resin matrix with a high ductility at low temperatures. This inner layer is allowed to cure and is encapsulated with a filamentwound outer composite layer of a distinct fiber resin system. Both inner and outer layer are in intimate contact, and can also be cured at the same time. The outer layer is a material that performs well for low temperature pressure vessels, and it can rely on the inner layer to act as a liner to contain the fluids. The outer layer can be a variety of materials, but the best embodiment may be the use of a continuous tow of carbon fiber (T-1000 carbon, or others), or other high-strength fibers combined with a high ductility epoxy resin matrix, or a polyurethane matrix, which performs well at low temperatures. After curing, the mandrel can be removed from the outer layer. While the hybrid structure is not limited to two particular materials, a preferred version of the tank has been demonstrated on an actual test tank article cycled at high pressures with liquid nitrogen and liquid hydrogen, and the best version is an inner layer of PBO (poly-pphenylenebenzobisoxazole) fibers with a polyurethane matrix and an outer layer of T-1000 carbon with a high elongation epoxy matrix suitable for cryogenic temperatures. A polyurethane matrix has also been used for the outer layer. The construction method is ideal because the fiber and resin of the inner layer has a high strain to failure at cryogenic temperatures, and will not crack or produce leaks. The outer layer serves as more of a high-performance structural unit for the inner layer, and can handle external environments.

An absorptive single-pole four-throw switch using multiple-contact MEMS switches and its application to a monolithic millimeter-wave beam-forming network

NASA Astrophysics Data System (ADS)

Lee, Sanghyo; Kim, Jong-Man; Kim, Yong-Kweon; Kwon, Youngwoo

2009-01-01

In this paper, a new absorptive single-pole four-throw (SP4T) switch based on multiple-contact switching is proposed and integrated with a Butler matrix to demonstrate a monolithic beam-forming network at millimeter waves (mm waves). In order to simplify the switching driving circuit and reduce the number of unit switches in an absorptive SP4T switch, the individual switches were replaced with long-span multiple-contact switches using stress-free single-crystalline-silicon MEMS technology. This approach improves the mechanical stability as well as the manufacturing yield, thereby allowing successful integration into a monolithic beam former. The fabricated absorptive SP4T MEMS switch shows insertion loss less than 1.3 dB, return losses better than 11 dB at 30 GHz and wideband isolation performance higher than 39 dB from 20 to 40 GHz. The absorptive SP4T MEMS switch is integrated with a 4 × 4 Butler matrix on a single chip to implement a monolithic beam-forming network, directing beam into four distinct angles. Array factors from the measured data show that the proposed absorptive SPnT MEMS switch can be effectively used for high-performance mm-wave beam-switching systems. This work corresponds to the first demonstration of a monolithic beam-forming network using switched beams.

Gardenia jasminoides Extract Attenuates the UVB-Induced Expressions of Cytokines in Keratinocytes and Indirectly Inhibits Matrix Metalloproteinase-1 Expression in Human Dermal Fibroblasts

PubMed Central

Seok, Jin Kyung; Suh, Hwa-Jin

2014-01-01

Ultraviolet radiation (UV) is a major cause of photoaging, which also involves inflammatory cytokines and matrix metalloproteinases (MMP). The present study was undertaken to examine the UVB-protecting effects of yellow-colored plant extracts in cell-based assays. HaCaT keratinocytes were exposed to UVB in the absence or presence of plant extracts, and resulting changes in cell viability and inflammatory cytokine expression were measured. Of the plant extracts tested, Gardenia jasminoides extract showed the lowest cytotoxicity and dose-dependently enhanced the viabilities of UVB-exposed cells. Gardenia jasminoides extract also attenuated the mRNA expressions of interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) in HaCaT cells stimulated by UVB. Conditioned medium from UVB-exposed HaCaT cells was observed to stimulate MMP-1 protein expression in human dermal fibroblasts, and this effect was much smaller for the conditioned medium of HaCaT cells exposed to UVB in the presence of Gardenia jasminoides extract. Gardenia jasminoides extract also exhibited antioxidative and antiapoptotic effects in HaCaT cells exposed to UVB. These results indicated that UVB-induced injury and inflammatory responses of skin cells can be attenuated by yellow-colored plant extracts, such as Gardenia jasminoides extract. PMID:24711853

Effects of the U boson on the inner edge of neutron star crusts

NASA Astrophysics Data System (ADS)

Zheng, Hao; Chen, Lie-Wen

2012-02-01

We explore effects of the light vector U boson, which is weakly coupled to nucleons, on the transition density ρt and pressure Pt at the inner edge separating the liquid core from the solid crust of neutron stars. Three methods, i.e., the thermodynamical approach, the curvature matrix approach, and the Vlasov equation approach, are used to determine the transition density ρt with the Skyrme effective nucleon-nucleon interactions. We find that the ρt and Pt depend on not only the ratio of coupling strength to mass squared of the U boson g2/μ2 but also its mass μ due to the finite-range interaction from the U-boson exchange. In particular, our results indicate that the ρt and Pt are sensitive to both g2/μ2 and μ if the U-boson mass μ is larger than about 2 MeV. Furthermore, we show that both g2/μ2 and μ can have significant influence on the mass-radius relation and the crustal fraction of total moment of inertia of neutron stars. In addition, we study the exchange term contribution of the U boson based on the density matrix expansion method, and demonstrate that the exchange term effects on the nuclear matter equation of state as well as the ρt and Pt are generally negligible.

Evolution equation of population genetics: Relation to the density-matrix theory of quasiparticles with general dispersion laws

NASA Astrophysics Data System (ADS)

Bezák, V.

2003-02-01

The Waxman-Peck theory of population genetics is discussed in regard of soil bacteria. Each bacterium is understood as a carrier of a phenotypic parameter p. The central objective is the calculation of the probability density with respect to p, Φ(p,t;p0), of the carriers living at time t>0, provided that initially at t0=0, all bacteria carried the phenotypic parameter p0=0. The theory involves two small parameters: the mutation probability μ and a parameter γ involved in a function w(p) defining the fitness of the bacteria to survive the generation time τ and give birth to an offspring. The mutation from a state p to a state q is defined by a Gaussian with a dispersion σ2m. The author focuses our attention on a function φ(p,t) which determines uniquely the function Φ(p,t;p0) and satisfies a linear equation (Waxman’s equation). The Green function of this equation is mathematically identical with the one-particle Bloch density matrix, where μ characterizes the order of magnitude of the potential energy. (In the x representation, the potential energy is proportional to the inverted Gaussian with the dispersion σ2m). The author solves Waxman’s equation in the standard style of a perturbation theory and discusses how the solution depends on the choice of the fitness function w(p). In a sense, the function c(p)=1-w(p)/w(0) is analogous to the dispersion function E(p) of fictitious quasiparticles. In contrast to Waxman’s approximation, where c(p) was taken as a quadratic function, c(p)≈γp2, the author exemplifies the problem with another function, c(p)=γ[1-exp(-ap2)], where γ is small but a may be large. The author shows that the use of this function in the theory of the population genetics is the same as the use of a nonparabolic dispersion law E=E(p) in the density-matrix theory. With a general function c(p), the distribution function Φ(p,t;0) is composed of a δ-function component, N(t)δ(p), and a blurred component. When discussing the limiting transition for t→∞, the author shows that his function c(p) implies that N(t)→N(∞)≠0 in contrast with the asymptotics N(t)→0 resulting from the use of Waxman’s function c(p)˜p2.

Discriminant projective non-negative matrix factorization.

PubMed

Guan, Naiyang; Zhang, Xiang; Luo, Zhigang; Tao, Dacheng; Yang, Xuejun

2013-01-01

Projective non-negative matrix factorization (PNMF) projects high-dimensional non-negative examples X onto a lower-dimensional subspace spanned by a non-negative basis W and considers W(T) X as their coefficients, i.e., X≈WW(T) X. Since PNMF learns the natural parts-based representation Wof X, it has been widely used in many fields such as pattern recognition and computer vision. However, PNMF does not perform well in classification tasks because it completely ignores the label information of the dataset. This paper proposes a Discriminant PNMF method (DPNMF) to overcome this deficiency. In particular, DPNMF exploits Fisher's criterion to PNMF for utilizing the label information. Similar to PNMF, DPNMF learns a single non-negative basis matrix and needs less computational burden than NMF. In contrast to PNMF, DPNMF maximizes the distance between centers of any two classes of examples meanwhile minimizes the distance between any two examples of the same class in the lower-dimensional subspace and thus has more discriminant power. We develop a multiplicative update rule to solve DPNMF and prove its convergence. Experimental results on four popular face image datasets confirm its effectiveness comparing with the representative NMF and PNMF algorithms.

A theoretical introduction to "combinatory SYBRGreen qPCR screening", a matrix-based approach for the detection of materials derived from genetically modified plants.

PubMed

Van den Bulcke, Marc; Lievens, Antoon; Barbau-Piednoir, Elodie; MbongoloMbella, Guillaume; Roosens, Nancy; Sneyers, Myriam; Casi, Amaya Leunda

2010-03-01

The detection of genetically modified (GM) materials in food and feed products is a complex multi-step analytical process invoking screening, identification, and often quantification of the genetically modified organisms (GMO) present in a sample. "Combinatory qPCR SYBRGreen screening" (CoSYPS) is a matrix-based approach for determining the presence of GM plant materials in products. The CoSYPS decision-support system (DSS) interprets the analytical results of SYBRGREEN qPCR analysis based on four values: the C(t)- and T(m) values and the LOD and LOQ for each method. A theoretical explanation of the different concepts applied in CoSYPS analysis is given (GMO Universe, "Prime number tracing", matrix/combinatory approach) and documented using the RoundUp Ready soy GTS40-3-2 as an example. By applying a limited set of SYBRGREEN qPCR methods and through application of a newly developed "prime number"-based algorithm, the nature of subsets of corresponding GMO in a sample can be determined. Together, these analyses provide guidance for semi-quantitative estimation of GMO presence in a food and feed product.

Robust Joining and Integration Technologies for Advanced Metallic, Ceramic, and Composite Systems

NASA Technical Reports Server (NTRS)

Singh, M.; Shpargel, Tarah; Morscher, Gregory N.; Halbig, Michael H.; Asthana, Rajiv

2006-01-01

Robust integration and assembly technologies are critical for the successful implementation of advanced metallic, ceramic, carbon-carbon, and ceramic matrix composite components in a wide variety of aerospace, space exploration, and ground based systems. Typically, the operating temperature of these components varies from few hundred to few thousand Kelvin with different working times (few minutes to years). The wide ranging system performance requirements necessitate the use of different integration technologies which includes adhesive bonding, low temperature soldering, active metal brazing, diffusion bonding, ARCJoinT, and ultra high temperature joining technologies. In this presentation, a number of joining examples and test results will be provided related to the adhesive bonding and active metal brazing of titanium to C/C composites, diffusion bonding of silicon carbide to silicon carbide using titanium interlayer, titanium and hastelloy brazing to silicon carbide matrix composites, and ARCJoinT joining of SiC ceramics and SiC matrix composites. Various issues in the joining of metal-ceramic systems including thermal expansion mismatch and resulting residual stresses generated during joining will be discussed. In addition, joint design and testing issues for a wide variety of joints will be presented.

Anomalous NMR Relaxation in Cartilage Matrix Components and Native Cartilage: Fractional-Order Models

PubMed Central

Magin, Richard L.; Li, Weiguo; Velasco, M. Pilar; Trujillo, Juan; Reiter, David A.; Morgenstern, Ashley; Spencer, Richard G.

2011-01-01

We present a fractional-order extension of the Bloch equations to describe anomalous NMR relaxation phenomena (T1 and T2). The model has solutions in the form of Mittag-Leffler and stretched exponential functions that generalize conventional exponential relaxation. Such functions have been shown by others to be useful for describing dielectric and viscoelastic relaxation in complex, heterogeneous materials. Here, we apply these fractional-order T1 and T2 relaxation models to experiments performed at 9.4 and 11.7 Tesla on type I collagen gels, chondroitin sulfate mixtures, and to bovine nasal cartilage (BNC), a largely isotropic and homogeneous form of cartilage. The results show that the fractional-order analysis captures important features of NMR relaxation that are typically described by multi-exponential decay models. We find that the T2 relaxation of BNC can be described in a unique way by a single fractional-order parameter (α), in contrast to the lack of uniqueness of multi-exponential fits in the realistic setting of a finite signal-to-noise ratio. No anomalous behavior of T1 was observed in BNC. In the single-component gels, for T2 measurements, increasing the concentration of the largest components of cartilage matrix, collagen and chondroitin sulfate, results in a decrease in α, reflecting a more restricted aqueous environment. The quality of the curve fits obtained using Mittag-Leffler and stretched exponential functions are in some cases superior to those obtained using mono- and bi-exponential models. In both gels and BNC, α appears to account for microstructural complexity in the setting of an altered distribution of relaxation times. This work suggests the utility of fractional-order models to describe T2 NMR relaxation processes in biological tissues. PMID:21498095

Fluid-driven cracks in an elastic matrix in the toughness-dominated limit

PubMed Central

Lai, Ching-Yao; Zheng, Zhong; Dressaire, Emilie

2016-01-01

The dynamics of fluid-driven cracks in an elastic matrix is studied experimentally. We report the crack radius R(t) as a function of time, as well as the crack shapes w(r,t) as a function of space and time. A dimensionless parameter, the pressure ratio Δpf/Δpv, is identified to gauge the relative importance between the toughness (Δpf) and viscous (Δpv) effects. In our previous paper (Lai et al. 2015 Proc. R. Soc. A 471, 20150255. (doi:10.1098/rspa.2015.0255)), we investigated the viscous limit experimentally when the toughness-related stresses are negligible for the crack propagation. In this paper, the experimental parameters, i.e. Young’s modulus E of the gelatin, viscosity μ of the fracturing liquid and the injection flow rate Q, were chosen so that the viscous effects in the flow are negligible compared with the toughness effects, i.e. Δpf/Δpv≫1. In this limit, the crack dynamics can be described by the toughness-dominated scaling laws, which give the crack radius R(t)∝t2/5 and the half maximum crack thickness W(t)∝t1/5. The experimental results are in good agreement with the predictions of the toughness scaling laws: the experimental data for crack radius R(t) for a wide range of parameters (E,μ,Q) collapse after being rescaled by the toughness scaling laws, and the rescaled crack shapes w(r,t) also collapse to a dimensionless shape, which demonstrates the self-similarity of the crack shape. The appropriate choice of the viscous or toughness scaling laws is important to accurately describe the crack dynamics. This article is part of the themed issue ‘Energy and the subsurface’. PMID:27597782

Anomalous NMR relaxation in cartilage matrix components and native cartilage: Fractional-order models

NASA Astrophysics Data System (ADS)

Magin, Richard L.; Li, Weiguo; Pilar Velasco, M.; Trujillo, Juan; Reiter, David A.; Morgenstern, Ashley; Spencer, Richard G.

2011-06-01

We present a fractional-order extension of the Bloch equations to describe anomalous NMR relaxation phenomena ( T1 and T2). The model has solutions in the form of Mittag-Leffler and stretched exponential functions that generalize conventional exponential relaxation. Such functions have been shown by others to be useful for describing dielectric and viscoelastic relaxation in complex, heterogeneous materials. Here, we apply these fractional-order T1 and T2 relaxation models to experiments performed at 9.4 and 11.7 Tesla on type I collagen gels, chondroitin sulfate mixtures, and to bovine nasal cartilage (BNC), a largely isotropic and homogeneous form of cartilage. The results show that the fractional-order analysis captures important features of NMR relaxation that are typically described by multi-exponential decay models. We find that the T2 relaxation of BNC can be described in a unique way by a single fractional-order parameter ( α), in contrast to the lack of uniqueness of multi-exponential fits in the realistic setting of a finite signal-to-noise ratio. No anomalous behavior of T1 was observed in BNC. In the single-component gels, for T2 measurements, increasing the concentration of the largest components of cartilage matrix, collagen and chondroitin sulfate, results in a decrease in α, reflecting a more restricted aqueous environment. The quality of the curve fits obtained using Mittag-Leffler and stretched exponential functions are in some cases superior to those obtained using mono- and bi-exponential models. In both gels and BNC, α appears to account for micro-structural complexity in the setting of an altered distribution of relaxation times. This work suggests the utility of fractional-order models to describe T2 NMR relaxation processes in biological tissues.

Thermal Conductivity and Erosion Durability of Composite Two-Phase Air Plasma Sprayed Thermal Barrier Coatings

NASA Technical Reports Server (NTRS)

Schmitt, Michael P.; Rai, Amarendra K.; Zhu, Dongming; Dorfman, Mitchell R.; Wolfe, Douglas E.

2015-01-01

To enhance efficiency of gas turbines, new thermal barrier coatings (TBCs) must be designed which improve upon the thermal stability limit of 7 wt% yttria stabilized zirconia (7YSZ), approximately 1200 C. This tenant has led to the development of new TBC materials and microstructures capable of improved high temperature performance. This study focused on increasing the erosion durability of cubic zirconia based TBCs, traditionally less durable than the metastable t' zirconia based TBCs. Composite TBC microstructures composed of a low thermal conductivity/high temperature stable cubic Low-k matrix phase and a durable t' Low-k secondary phase were deposited via APS. Monolithic coatings composed of cubic Low-k and t' Low-k were also deposited, in addition to a 7YSZ benchmark. The thermal conductivity and erosion durability were then measured and it was found that both of the Low-k materials have significantly reduced thermal conductivities, with monolithic t' Low-k and cubic Low-k improving upon 7YSZ by approximately 13 and approximately 25%, respectively. The 40 wt% t' Low-k composite (40 wt% t' Low-k - 60 wt% cubic Low-k) showed a approximately 22% reduction in thermal conductivity over 7YSZ, indicating even at high levels, the t' Low-k secondary phase had a minimal impact on thermal in the composite coating. It was observed that a mere 20 wt% t' Low-k phase addition can reduce the erosion of a cubic Low-k matrix phase composite coating by over 37%. Various mixing rules were then investigated to assess this non-linear composite behavior and suggestions were made to further improve erosion durability.

Novel actions of tissue-type plasminogen activator in chronic kidney disease: a paradigm shift

PubMed Central

Hu, Kebin; Mars, Wendy M.; Liu, Youhua

2009-01-01

Tissue-type plasminogen activator (tPA) is traditionally viewed as a simple serine protease whose main function is to convert plasminogen into biologically active plasmin. As a protease, tPA plays a crucial role in regulating blood fibrinolysis, in maintaining the homeostasis of extracellular matrix (ECM) and in modulating the post-translational activation of growth factors. However, emerging evidence indicates that tPA may also function as a cytokine that transmits its signal across the cell membrane, initiates a diverse array of intracellular signaling, and dictates gene expression in the nuclei. Structurally, tPA is a kringle-containing protein that shares significant similarity to other classic cytokines such as hepatocyte growth factor (HGF) and macrophage-stimulating protein (MSP). Although there is no dedicated receptor, tPA binds to the cell membrane low density lipoprotein (LDL) receptor-related protein-1 (LRP-1), triggers LRP-1 tyrosine phosphorylation, and activates various intracellular signaling. As a cytokine, tPA plays a pivotal role in the pathogenesis of renal interstitial fibrosis through diverse mechanisms. It induces matrix matelloproteinase-9 (MMP-9) gene expression in renal interstitial fibroblasts, which causes the destruction of the tubular basement membrane (TBM), thereby facilitating tubular epithelial to mesenchymal transition (EMT). tPA also potentiates myofibroblast activation from quiescent interstitial fibroblasts through LRP-1-mediated recruitment of β1 integrin signaling. Furthermore, tPA acts as a survival factor that protects renal interstitial fibroblasts/myofibroblasts from apoptosis, thereby resulting in an expansion of myofibroblast populations in diseased kidney. Together, a growing body of evidence has implicated tPA as a fibrogenic cytokine that promotes the progression of kidney diseases. These new findings have radically changed our conception of tPA in renal fibrogenesis and represent a paradigm shift towards uncovering its cytokine function. A better understanding of renal tPA biology will ultimately translate into more rational therapeutic remedies for patients with chronic kidney fibrosis. PMID:18508579

Control Synthesis of Discrete-Time T-S Fuzzy Systems: Reducing the Conservatism Whilst Alleviating the Computational Burden.

PubMed

Xie, Xiangpeng; Yue, Dong; Zhang, Huaguang; Peng, Chen

2017-09-01

The augmented multi-indexed matrix approach acts as a powerful tool in reducing the conservatism of control synthesis of discrete-time Takagi-Sugeno fuzzy systems. However, its computational burden is sometimes too heavy as a tradeoff. Nowadays, reducing the conservatism whilst alleviating the computational burden becomes an ideal but very challenging problem. This paper is toward finding an efficient way to achieve one of satisfactory answers. Different from the augmented multi-indexed matrix approach in the literature, we aim to design a more efficient slack variable approach under a general framework of homogenous matrix polynomials. Thanks to the introduction of a new extended representation for homogeneous matrix polynomials, related matrices with the same coefficient are collected together into one sole set and thus those redundant terms of the augmented multi-indexed matrix approach can be removed, i.e., the computational burden can be alleviated in this paper. More importantly, due to the fact that more useful information is involved into control design, the conservatism of the proposed approach as well is less than the counterpart of the augmented multi-indexed matrix approach. Finally, numerical experiments are given to show the effectiveness of the proposed approach.

PDLIM2 suppresses human T-cell leukemia virus type I Tax-mediated tumorigenesis by targeting Tax into the nuclear matrix for proteasomal degradation

PubMed Central

Yan, Pengrong; Fu, Jing; Qu, Zhaoxia; Li, Shirong; Tanaka, Takashi; Grusby, Michael J.

2009-01-01

The mechanisms by which the human T-cell leukemia virus type I (HTLV-I) Tax oncoprotein deregulates cellular signaling for oncogenesis have been extensively studied, but how Tax itself is regulated remains largely unknown. Here we report that Tax was negatively regulated by PDLIM2, which promoted Tax K48-linked polyubiquitination. In addition, PDLIM2 recruited Tax from its functional sites into the nuclear matrix where the polyubiquitinated Tax was degraded by the proteasome. Consistently, PDLIM2 suppressed Tax-mediated signaling activation, cell transformation, and oncogenesis both in vitro and in animal. Notably, PDLIM2 expression was down-regulated in HTLV-I–transformed T cells, and PDLIM2 reconstitution reversed the tumorigenicity of the malignant cells. These studies indicate that the counterbalance between HTLV-I/Tax and PDLIM2 may determine the outcome of HTLV-I infection. These studies also suggest a potential therapeutic strategy for cancers and other diseases associated with HTLV-I infection and/or PDLIM2 deregulation. PMID:19131544

Wavefront reconstruction algorithm based on Legendre polynomials for radial shearing interferometry over a square area and error analysis.

PubMed

Kewei, E; Zhang, Chen; Li, Mengyang; Xiong, Zhao; Li, Dahai

2015-08-10

Based on the Legendre polynomials expressions and its properties, this article proposes a new approach to reconstruct the distorted wavefront under test of a laser beam over square area from the phase difference data obtained by a RSI system. And the result of simulation and experimental results verifies the reliability of the method proposed in this paper. The formula of the error propagation coefficients is deduced when the phase difference data of overlapping area contain noise randomly. The matrix T which can be used to evaluate the impact of high-orders Legendre polynomial terms on the outcomes of the low-order terms due to mode aliasing is proposed, and the magnitude of impact can be estimated by calculating the F norm of the T. In addition, the relationship between ratio shear, sampling points, terms of polynomials and noise propagation coefficients, and the relationship between ratio shear, sampling points and norms of the T matrix are both analyzed, respectively. Those research results can provide an optimization design way for radial shearing interferometry system with the theoretical reference and instruction.

An efficient gridding reconstruction method for multishot non-Cartesian imaging with correction of off-resonance artifacts.

PubMed

Meng, Yuguang; Lei, Hao

2010-06-01

An efficient iterative gridding reconstruction method with correction of off-resonance artifacts was developed, which is especially tailored for multiple-shot non-Cartesian imaging. The novelty of the method lies in that the transformation matrix for gridding (T) was constructed as the convolution of two sparse matrices, among which the former is determined by the sampling interval and the spatial distribution of the off-resonance frequencies and the latter by the sampling trajectory and the target grid in the Cartesian space. The resulting T matrix is also sparse and can be solved efficiently with the iterative conjugate gradient algorithm. It was shown that, with the proposed method, the reconstruction speed in multiple-shot non-Cartesian imaging can be improved significantly while retaining high reconstruction fidelity. More important, the method proposed allows tradeoff between the accuracy and the computation time of reconstruction, making customization of the use of such a method in different applications possible. The performance of the proposed method was demonstrated by numerical simulation and multiple-shot spiral imaging on rat brain at 4.7 T. (c) 2010 Wiley-Liss, Inc.

Selective matrix metalloproteinase inhibitor, N-biphenyl sulfonyl phenylalanine hydroxamic acid, inhibits the migration of CD4+ T lymphocytes in patients with HTLV-I-associated myelopathy.

PubMed

Ikegami, Mayumi; Umehara, Fujio; Ikegami, Naohito; Maekawa, Ryuji; Osame, Mitsuhiro

2002-06-01

Matrix metalloproteinases (MMPs) have been reported to be involved in various inflammatory disorders. Previous studies revealed that MMP-2 and MMP-9 might play important roles in the breakdown of the blood-brain barrier (BBB) in the central nervous system (CNS) of patients with HTLV-I-associated myelopathy (HAM)/tropical spastic paraparesis (TSP). N-Biphenyl sulfonyl-phenylalanine hydroxamic acid (BPHA) selectively inhibits MMP-2, -9 and -14, but not MMP-1, -3 and -7. In the present study, we examined whether or not the selective MMP inhibitor BPHA could inhibit the heightened migrating activity of CD4+ T cells in HAM/TSP patients. The migration assay using an invasion chamber showed that migration of CD4+ T cells in HAM/TSP patients was inhibited by 25 microM BPHA. In addition, the inhibitory ratio of migrating CD4+ lymphocytes was higher in HAM patients compared to normal controls. These results suggest that the selective MMP inhibitor BPHA has therapeutic potential for HAM/TSP.

Tumor-derived microvesicles mediate human breast cancer invasion through differentially glycosylated EMMPRIN

PubMed Central

Menck, Kerstin; Scharf, Christian; Bleckmann, Annalen; Dyck, Lydia; Rost, Ulrike; Wenzel, Dirk; Dhople, Vishnu M.; Siam, Laila; Pukrop, Tobias; Binder, Claudia; Klemm, Florian

2015-01-01

Tumor cells secrete not only a variety of soluble factors, but also extracellular vesicles that are known to support the establishment of a favorable tumor niche by influencing the surrounding stroma cells. Here we show that tumor-derived microvesicles (T-MV) also directly influence the tumor cells by enhancing their invasion in a both autologous and heterologous manner. Neither the respective vesicle-free supernatant nor MV from benign mammary cells mediate invasion. Uptake of T-MV is essential for the proinvasive effect. We further identify the highly glycosylated form of the extracellular matrix metalloproteinase inducer (EMMPRIN) as a marker for proinvasive MV. EMMPRIN is also present at high levels on MV from metastatic breast cancer patients in vivo. Anti-EMMPRIN strategies, such as MV deglycosylation, gene knockdown, and specific blocking peptides, inhibit MV-induced invasion. Interestingly, the effect of EMMPRIN-bearing MV is not mediated by matrix metalloproteinases but by activation of the p38/MAPK signaling pathway in the tumor cells. In conclusion, T-MV stimulate cancer cell invasion via a direct feedback mechanism dependent on highly glycosylated EMMPRIN. PMID:25503107

Controlling excited-state contamination in nucleon matrix elements

DOE PAGES

Yoon, Boram; Gupta, Rajan; Bhattacharya, Tanmoy; ...

2016-06-08

We present a detailed analysis of methods to reduce statistical errors and excited-state contamination in the calculation of matrix elements of quark bilinear operators in nucleon states. All the calculations were done on a 2+1-flavor ensemble with lattices of size 32 3 × 64 generated using the rational hybrid Monte Carlo algorithm at a = 0.081 fm and with M π = 312 MeV. The statistical precision of the data is improved using the all-mode-averaging method. We compare two methods for reducing excited-state contamination: a variational analysis and a 2-state fit to data at multiple values of the source-sink separationmore » t sep. We show that both methods can be tuned to significantly reduce excited-state contamination and discuss their relative advantages and cost effectiveness. As a result, a detailed analysis of the size of source smearing used in the calculation of quark propagators and the range of values of t sep needed to demonstrate convergence of the isovector charges of the nucleon to the t sep → ∞ estimates is presented.« less

Systematic R -matrix analysis of the 13C(p ,γ )14N capture reaction

NASA Astrophysics Data System (ADS)

Chakraborty, Suprita; deBoer, Richard; Mukherjee, Avijit; Roy, Subinit

2015-04-01

Background: The proton capture reaction 13C(p ,γ )14N is an important reaction in the CNO cycle during hydrogen burning in stars with mass greater than the mass of the Sun. It also occurs in astrophysical sites such as red giant stars: the asymptotic giant branch (AGB) stars. The low energy astrophysical S factor of this reaction is dominated by a resonance state at an excitation energy of around 8.06 MeV (Jπ=1-,T =1 ) in 14N. The other significant contributions come from the low energy tail of the broad resonance with Jπ=0-,T =1 at an excitation of 8.78 MeV and the direct capture process. Purpose: Measurements of the low energy astrophysical S factor of the radiative capture reaction 13C(p ,γ )14N reported extrapolated values of S (0 ) that differ by about 30 % . Subsequent R -matrix analysis and potential model calculations also yielded significantly different values for S (0 ) . The present work intends to look into the discrepancy through a detailed R -matrix analysis with emphasis on the associated uncertainties. Method: A systematic reanalysis of the available decay data following the capture to the Jπ=1-,T =1 resonance state of 14N around 8.06 MeV excitation had been performed within the framework of the R -matrix method. A simultaneous analysis of the 13C(p ,p0 ) data, measured over a similar energy range, was carried out with the capture data. The data for the ground state decay of the broad resonance state (Jπ=0-,T =1 ) around 8.78 MeV excitations was included as well. The external capture model along with the background poles to simulate the internal capture contribution were used to estimate the direct capture contribution. The asymptotic normalization constants (ANCs) for all states were extracted from the capture data. The multichannel, multilevel R -matrix code azure2 was used for the calculation. Results: The values of the astrophysical S factor at zero relative energy, resulting from the present analysis, are found to be consistent within the error bars for the two sets of capture data used. However, it is found from the fits to the elastic scattering data that the position of the Jπ=1-,T =1 resonance state is uncertain by about 0.6 keV, preferring an excitation energy value of 8.062 MeV. Also the extracted ANC values for the states of 14N corroborate the values from the transfer reaction studies. The reaction rates from the present calculation are about 10 -15 % lower than the values of the NACRE II compilation but compare well with those from NACRE I. Conclusion: The precise energy of the Jπ=1-,T =1 resonance level around 8.06 MeV in 14N must be determined. Further measurements around and below 100 keV with precision are necessary to reduce the uncertainty in the S -factor value at zero relative energy.

T-bet-dependent NKp46+ innate lymphoid cells regulate the onset of TH17-induced neuroinflammation.

PubMed

Kwong, Brandon; Rua, Rejane; Gao, Yuanyuan; Flickinger, John; Wang, Yan; Kruhlak, Michael J; Zhu, Jinfang; Vivier, Eric; McGavern, Dorian B; Lazarevic, Vanja

2017-10-01

The transcription factor T-bet has been associated with increased susceptibility to systemic and organ-specific autoimmunity, but the mechanism by which T-bet expression promotes neuroinflammation remains unknown. In this study, we demonstrate a cardinal role of T-bet-dependent NKp46 + innate lymphoid cells (ILCs) in the initiation of CD4 + T H 17-mediated neuroinflammation. Loss of T-bet specifically in NKp46 + ILCs profoundly impaired the ability of myelin-reactive T H 17 cells to invade central nervous system (CNS) tissue and protected the mice from autoimmunity. T-bet-dependent NKp46 + ILCs localized in the meninges and acted as chief coordinators of meningeal inflammation by inducing the expression of proinflammatory cytokines, chemokines and matrix metalloproteinases, which together facilitated T cell entry into CNS parenchyma. Our findings uncover a detrimental role of T-bet-dependent NKp46 + ILCs in the development of CNS autoimmune disease.

Scattering Properties of Needle-Like and plate-like Ice Spheroids with Moderate Size Parameters

NASA Technical Reports Server (NTRS)

Zakharova, Nadia T.; Mishchenko, Michael I.; Hansen, James E. (Technical Monitor)

2000-01-01

We use the current advanced version of the T-matrix method to compute the optical cross sections, the asymmetry parameter of the phase function, and the scattering matrix elements of ice spheroids with aspect ratios up to 20 and surface-equivalent-sphere size parameters up to 12. We demonstrate that plate-like and needle-like particles with moderate size parameters possess unique scattering properties: their asymmetry parameters and phase functions are similar to those of surface-equivalent spheres, whereas all other elements of the scattering matrix are typical of particles much smaller than the wavelength (Rayleigh scatterers). This result may have important implications for optical particle sizing and remote sensing of the terrestrial and planetary atmospheres.

Effect of degree of esterification of pectin and calcium amount on drug release from pectin-based matrix tablets.

PubMed

Sungthongjeen, Srisagul; Sriamornsak, Pornsak; Pitaksuteepong, Tasana; Somsiri, Atawit; Puttipipatkhachorn, Satit

2004-02-12

The aim of this work was to assess the effect of 2 formulation variables, the pectin type (with different degrees of esterification [DEs]) and the amount of calcium, on drug release from pectin-based matrix tablets. Pectin matrix tablets were prepared by blending indomethacin (a model drug), pectin powder, and various amounts of calcium acetate and then tableting by automatic hydraulic press machine. Differential scanning calorimetry, powder x-ray diffraction, and Fourier transformed-infrared spectroscopy studies of the compressed tablets revealed no drug-polymer interaction and the existence of drug with low crystallinity. The in-vitro release studies in phosphate buffer (United States Pharmacopeia) and tris buffer indicated that the lower the DE, the greater the time for 50% of drug release (T50). This finding is probably because of the increased binding capacity of pectin to calcium. However, when the calcium was excluded, the pectins with different DEs showed similar release pattern with insignificant difference of T50. When the amount of calcium acetate was increased from 0 to 12 mg/tablet, the drug release was significantly slower. However, a large amount of added calcium (ie, 24 mg/tablet) produced greater drug release because of the partial disintegration of tablets. The results were more pronounced in phosphate buffer, where the phosphate ions induced the precipitation of calcium phosphate. In conclusion, both pectin type and added calcium affect the drug release from the pectin-based matrix tablets.

In house validation of a high resolution mass spectrometry Orbitrap-based method for multiple allergen detection in a processed model food.

PubMed

Pilolli, Rosa; De Angelis, Elisabetta; Monaci, Linda

2018-02-13

In recent years, mass spectrometry (MS) has been establishing its role in the development of analytical methods for multiple allergen detection, but most analyses are being carried out on low-resolution mass spectrometers such as triple quadrupole or ion traps. In this investigation, performance provided by a high resolution (HR) hybrid quadrupole-Orbitrap™ MS platform for the multiple allergens detection in processed food matrix is presented. In particular, three different acquisition modes were compared: full-MS, targeted-selected ion monitoring with data-dependent fragmentation (t-SIM/dd2), and parallel reaction monitoring. In order to challenge the HR-MS platform, the sample preparation was kept as simple as possible, limited to a 30-min ultrasound-aided protein extraction followed by clean-up with disposable size exclusion cartridges. Selected peptide markers tracing for five allergenic ingredients namely skim milk, whole egg, soy flour, ground hazelnut, and ground peanut were monitored in home-made cookies chosen as model processed matrix. Timed t-SIM/dd2 was found the best choice as a good compromise between sensitivity and accuracy, accomplishing the detection of 17 peptides originating from the five allergens in the same run. The optimized method was validated in-house through the evaluation of matrix and processing effects, recoveries, and precision. The selected quantitative markers for each allergenic ingredient provided quantification of 60-100 μg ingred /g allergenic ingredient/matrix in incurred cookies.

Import of desired nucleic acid sequences using addressing motif of mitochondrial ribosomal 5S-rRNA for fluorescent in vivo hybridization of mitochondrial DNA and RNA.

PubMed

Zelenka, Jaroslav; Alán, Lukáš; Jabůrek, Martin; Ježek, Petr

2014-04-01

Based on the matrix-addressing sequence of mitochondrial ribosomal 5S-rRNA (termed MAM), which is naturally imported into mitochondria, we have constructed an import system for in vivo targeting of mitochondrial DNA (mtDNA) or mt-mRNA, in order to provide fluorescence hybridization of the desired sequences. Thus DNA oligonucleotides were constructed, containing the 5'-flanked T7 RNA polymerase promoter. After in vitro transcription and fluorescent labeling with Alexa Fluor(®) 488 or 647 dye, we obtained the fluorescent "L-ND5 probe" containing MAM and exemplar cargo, i.e., annealing sequence to a short portion of ND5 mRNA and to the light-strand mtDNA complementary to the heavy strand nd5 mt gene (5'-end 21 base pair sequence). For mitochondrial in vivo fluorescent hybridization, HepG2 cells were treated with dequalinium micelles, containing the fluorescent probes, bringing the probes proximally to the mitochondrial outer membrane and to the natural import system. A verification of import into the mitochondrial matrix of cultured HepG2 cells was provided by confocal microscopy colocalizations. Transfections using lipofectamine or probes without 5S-rRNA addressing MAM sequence or with MAM only were ineffective. Alternatively, the same DNA oligonucleotides with 5'-CACC overhang (substituting T7 promoter) were transcribed from the tetracycline-inducible pENTRH1/TO vector in human embryonic kidney T-REx®-293 cells, while mitochondrial matrix localization after import of the resulting unlabeled RNA was detected by PCR. The MAM-containing probe was then enriched by three-order of magnitude over the natural ND5 mRNA in the mitochondrial matrix. In conclusion, we present a proof-of-principle for mitochondrial in vivo hybridization and mitochondrial nucleic acid import.

The effects of long-duration space exposure on the mechanical properties of some carbon-reinforced resin matrix composites

NASA Technical Reports Server (NTRS)

Vyhnal, Richard F.

1993-01-01

Long Duration Exposure Facility (LDEF) Experiment A0175 involved the non-instrumented exposure of seven carbon-fiber reinforced resin-matrix advanced composite panels contained in two trays - A7 and A1. These two trays were located, respectively, on the leading and trailing faces of LDEF, obliquely oriented to the RAM (Row 9) and WAKE (Row 3) directions. The identity and location of the seven panels, which consisted of six flat laminates of the following material systems are shown: carbon/epoxy (T300/934), carbon/bismaleimide (T300/F178), and carbon/polyimide (C6000/LARC-160 and C6000/PMR-15), plus one bonded honeycomb sandwich panel (T300/934 face sheets and Nomex core) patterned after the Space Shuttle payload bay door construction. These material systems were selected to represent a range of then-available matrix resins which, by virtue of their differing polymer chemistry, could conceivably exhibit differing susceptibility to the low-earth orbit (LEO) environment. The principal exposure conditions of the LDEF environment at these tray locations are shown. Noteworthy to some of the observations discussed is the four-orders-of magnitude difference in the atomic oxygen (AO) fluence, which made a shallow incidence angle (approximately 22 deg) to Tray A7, while Tray A1 on the trailing face was essentially shielded from AO exposure. This evaluation focused on determining the individual and relative suitability of a variety of resin-matrix composite systems for long-term space structural applications. This was accomplished primarily by measuring and comparing a range of engineering mechanical properties on over 300 test coupons sectioned from the flight panels and from identical control panels, and tested at ambient and elevated temperatures. This testing was supported by limited physical characterization, involving visual examination of flight panel surface features, measurements of weight loss and warpage, and examination for changes in internal integrity (micro cracking, delamination) by ultrasonic c-scan and polished cross-sections.

A Routing Protocol for Packet Radio Networks

DTIC Science & Technology

1995-01-01

table of node K is a matrix containing, for each destination L and each neighbor of K (say M ), the distance to L ( NEOPRQ ) and the predecessor ( S OP Q...identifier T The distance to the destination ( N OP ) T The predecessor of the shortest path chosen toward L ( S OP ) T The successor ( U OP ) of the shortest...P and the predecessor is updated as S OP À ¾ S Q P . Thus, a node can determine whether or not an update received from M affects its other distance

Flexible phosphorescent OLEDs on metal foil for military and commercial applications

NASA Astrophysics Data System (ADS)

Chwang, Anna; Lu, JengPing; Shih, Chinwen; Tung, Yeh-Jiun; Hewitt, Richard; Hack, Michael; Ho, Jackson; Brown, Julie

2005-05-01

We report recent advances in the development of low power consumption, emissive, flexible active matrix displays through integration of top emitting phosphorescent OLED (T-PHOLED) and poly-Si TFT backplane technologies. The displays are fabricated on flexible stainless steel foil. The T-PHOLEDs are based on UDC phosphorescent OLED technology, and the backplane is based on PARC's Excimer Laser Annealed (ELA) poly-Si TFT process. We also present progress in operational lifetime of encapsulated T-PHOLED pixels on planarized metal foil and discuss PHOLED encapsulation strategy.

EFFECTS OF ULTRAVIOLET LIGHT ON R-7,T-8-DIHYDROXY-T-9,10-EPOXY-7,8,9,10-TETRAHYDROBENZO[A]PYRENE (BPDE)-DNA ADDUCTS ADSORBED ON FILTER PAPER AND THE DETECTION OF TETROLS BY SYNCHRONOUS SOLID-MATRIX PHOSPHORESCENCE. (R824100)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

EUROGRAM, September-October 1994

DTIC Science & Technology

1994-10-01

finished a comprehensive report on the characteristics of mining- at the Institute, induced seismicity. The Kolar Gold Fields were first mined by the...engineering applications. Spherics standard and jets, unsteady combustion, and fuel cells. A full listing of ball products are machined and finished from...can now be directly downloaded ELO§RJ3t #94-)5 tSep-Oct 94) It chemis.r, proc:essing. finishing protocol and applications for ceramic matrix

Scattering Matrix Elements for the Nonadiabatic Collision

DTIC Science & Technology

2010-12-01

orthogonality relationship expressed in (77). This technique, known as the Channel Packet Method (CPM), is laid out by Weeks and Tannor [2...time and energy are Fourier transform pairs, and share the same relationship as the coordinate/momentum pairs: max min 2E t t π ∆ = − (99) As...elements, will exibit ringing. Selection of an inappropriatly large time step introduces an erroneous phase shift in the correlation funtion . This

Fidelity decay of the two-level bosonic embedded ensembles of random matrices

NASA Astrophysics Data System (ADS)

Benet, Luis; Hernández-Quiroz, Saúl; Seligman, Thomas H.

2010-12-01

We study the fidelity decay of the k-body embedded ensembles of random matrices for bosons distributed over two single-particle states. Fidelity is defined in terms of a reference Hamiltonian, which is a purely diagonal matrix consisting of a fixed one-body term and includes the diagonal of the perturbing k-body embedded ensemble matrix, and the perturbed Hamiltonian which includes the residual off-diagonal elements of the k-body interaction. This choice mimics the typical mean-field basis used in many calculations. We study separately the cases k = 2 and 3. We compute the ensemble-averaged fidelity decay as well as the fidelity of typical members with respect to an initial random state. Average fidelity displays a revival at the Heisenberg time, t = tH = 1, and a freeze in the fidelity decay, during which periodic revivals of period tH are observed. We obtain the relevant scaling properties with respect to the number of bosons and the strength of the perturbation. For certain members of the ensemble, we find that the period of the revivals during the freeze of fidelity occurs at fractional times of tH. These fractional periodic revivals are related to the dominance of specific k-body terms in the perturbation.

Characterization of erosion of metallic materials under cavitation attack in a mineral oil

NASA Technical Reports Server (NTRS)

Rao, B. C. S.; Buckley, D. H.

1985-01-01

Cavitation erosion and erosion rates of eight metallic materials representing three crystal structures were studied. The erosion experiments were conducted with a 20-kHz ultrasonic magnetostrictive oscillator in a viscous mineral oil. The erosion rates of the metals with an fcc matrix were 10 to 100 times higher than that of an hop-matrix titanium alloy. The erosion rates of iron and molybdenum, with bcc matrices, were higher than that of the titanium alloy but lower than those of those of the fcc materials. Studies with scanning electron microscopy indicated that the cavitation pits were initially formed at the grain boundaries and precipitates and that the pits formed at the junction of grain boundaries grew faster than the others. Transcrystalline craters formed by cavitation attack over the surface of grains and roughened the surfaces by multiple slip and twinning. Surface roughness measurements showed that the pits that formed over the grain boundaries deepened faster than pits. Computer analysis revealed that a geometric expression describes the nondimensional erosion curves during the time period 0.5 t (sub 0) t 2.5 t (sub 0), where t (sub 0) is the incubation period. The fcc metals had very short incubation periods; the titanium alloy had the longest incubation period.

Cloned cytolytic T-effector cells and their malignant variants produce an extracellular matrix degrading trypsin-like serine proteinase.

PubMed Central

Simon, M M; Simon, H G; Fruth, U; Epplen, J; Müller-Hermelink, H K; Kramer, M D

1987-01-01

This report describes the distribution of a trypsin-like proteinase in defined homogeneous cytolytic T-cell lines (CTLL) and their in vitro and in vivo derived malignant T-lymphoma variants. By means of chromogenic peptide substrates, we found the enzyme to attack preferentially at the carboxy terminus of arginine, in particular when non-polar amino acids were present in the amino terminal neighbouring position. The enzyme was identified by means of various inhibitors as a serine type proteinase having a pH optimum around 8 X 5. Affinity chromatography in connection with molecular sieving resulted in a 200-fold purification and indicated a molecular weight (MW) of about 50,000 for the proteinase. The enzyme was found to be highly expressed in antigen-specific CTLL as well as in their tumorigenic variants. Both intact lymphocytes of all CTLL tested and Triton X-100 lysates or enriched proteinase preparations thereof were able to degrade a high molecular weight protein (casein) and to release high molecular weight split products from the sulphated proteoglycans in subendothelial extracellular matrix. The results are discussed with respect to the invasiveness of normal and malignant T lymphocytes and the proteinase is suggested to be crucially involved in the process of cellular migration in vivo. Images Figure 1 PMID:3546101

Protein and modified vaccinia virus Ankara-based influenza virus nucleoprotein vaccines are differentially immunogenic in BALB/c mice.

PubMed

Altenburg, A F; Magnusson, S E; Bosman, F; Stertman, L; de Vries, R D; Rimmelzwaan, G F

2017-10-01

Because of the high variability of seasonal influenza viruses and the eminent threat of influenza viruses with pandemic potential, there is great interest in the development of vaccines that induce broadly protective immunity. Most probably, broadly protective influenza vaccines are based on conserved proteins, such as nucleoprotein (NP). NP is a vaccine target of interest as it has been shown to induce cross-reactive antibody and T cell responses. Here we tested and compared various NP-based vaccine preparations for their capacity to induce humoral and cellular immune responses to influenza virus NP. The immunogenicity of protein-based vaccine preparations with Matrix-M™ adjuvant as well as recombinant viral vaccine vector modified Vaccinia virus Ankara (MVA) expressing the influenza virus NP gene, with or without modifications that aim at optimization of CD8 + T cell responses, was addressed in BALB/c mice. Addition of Matrix-M™ adjuvant to NP wild-type protein-based vaccines significantly improved T cell responses. Furthermore, recombinant MVA expressing the influenza virus NP induced strong antibody and CD8 + T cell responses, which could not be improved further by modifications of NP to increase antigen processing and presentation. © 2017 British Society for Immunology.

Prognostic role of extracellular matrix metalloproteinase inducer/CD147 in gastrointestinal cancer: a meta-analysis of related studies.

PubMed

Huang, Xiaohui; Shen, Weisong; Xi, Hongqing; Zhang, Kecheng; Cui, Jianxin; Wei, Bo; Chen, Lin

2016-12-06

The prognostic role of Extracellular matrix metalloproteinase inducer (EMMPRIN/ CD147) in gastrointestinal cancer remains controversial. We systematically reviewed the evidence of assessment of CD147 expression in gastrointestinal cancer to help clarify this issue. Pubmed, Embase, Cochrane Library and Web of Science databases were searched to identify eligible studies to evaluate the association of CD147 expression and disease-free and overall survival of gastrointestinal cancer. Hazard ratios (HRs) were pooled to estimate the effect. CD147 overexpression was significantly correlated with poor disease-free survival (HR 2.38, 95% CI 1.43-3.97) and overall survival (HR 1.64, 95% CI 1.25-2.14) of cancer patients. Furthermore, CD147 overexpression was significantly association with TNM stage (TIII/TIV vs TI/TII: OR 3.60, 95% CI 1.85-7.01), the depth of invasion (T3/T4 vs T1/T2: OR 2.04, 95% CI 1.25-3.33), lymph node metastasis (positive vs negative: 2.35, 95% CI 1.14-4.86), distant metastasis (positive vs negative: OR 4.78, 95% CI 1.43-16.00). Our analyses demonstrate that CD147 was effectively predictive of worse prognosis in gastrointestinal cancer. Moreover, Identifying CD147 may help identify new drug targets for cancer therapy.

On the equilibrium state of a small system with random matrix coupling to its environment

NASA Astrophysics Data System (ADS)

Lebowitz, J. L.; Pastur, L.

2015-07-01

We consider a random matrix model of interaction between a small n-level system, S, and its environment, a N-level heat reservoir, R. The interaction between S and R is modeled by a tensor product of a fixed n× n matrix and a N× N Hermitian random matrix. We show that under certain ‘macroscopicity’ conditions on R, the reduced density matrix of the system {{ρ }S}=T{{r}R}ρ S\\cup R(eq), is given by ρ S(c)˜ exp \\{-β {{H}S}\\}, where HS is the Hamiltonian of the isolated system. This holds for all strengths of the interaction and thus gives some justification for using ρ S(c) to describe some nano-systems, like biopolymers, in equilibrium with their environment (Seifert 2012 Rep. Prog. Phys. 75 126001). Our results extend those obtained previously in (Lebowitz and Pastur 2004 J. Phys. A: Math. Gen. 37 1517-34) (Lebowitz et al 2007 Contemporary Mathematics (Providence RI: American Mathematical Society) pp 199-218) for a special two-level system.

Mathematical modeling of photovoltaic thermal PV/T system with v-groove collector

NASA Astrophysics Data System (ADS)

Zohri, M.; Fudholi, A.; Ruslan, M. H.; Sopian, K.

2017-07-01

The use of v-groove in solar collector has a higher thermal efficiency in references. Dropping the working heat of photovoltaic panel was able to raise the electrical efficiency performance. Electrical and thermal efficiency were produced by photovoltaic thermal (PV/T) system concurrently. Mathematical modeling based on steady-state thermal analysis of PV/T system with v-groove was conducted. With matrix inversion method, the energy balance equations are explained by means of the investigative method. The comparison results show that in the PV/T system with the V-groove collector is higher temperature, thermal and electrical efficiency than other collectors.

U.S. Navy Hindcast Spectral Ocean Wave Model Climatic Atlas: Mediterranean Sea

DTIC Science & Technology

1990-01-01

8217 (total) were obtained by summing the percent frequencies across each row. Rounding may cause minor differences between printed totals and total cell counts...34c9 3 N6 l7 4, i 5E F TI + e "t1- 4TI 3- ’$69"- -’ - + el4 𔄃 t 14 t , + t. -. ----- + 13,, 6 6 , 4- +0 2 4 9,: o . ;.. .;,+ + 5 ., 𔃿 6.--’ r’ ---- ’p...The SOWM generates ’en-.!rgy ’ariaLLcb’ cell within the 180 element matrix f The output from a SOWM hindcast includes a wind fields. There is a

A Framework for Collaborative Quadrotor - Ground Robot Missions

DTIC Science & Technology

2011-12-01

corresponds to the following criteria (117) ( ) ( ) ( )X t AX t BU t  cK ( ) ( )cU t K X t  0 ( )T TJ X QX U RU dt      2 2 1 , 1,2...pattern (wanding process), whose edges have reflectors on the top, within the whole space trying to cover every possible view angle of each of the...BR RS  , where ( ) BS  is a skew symmetric matrix. The term ( )B BS V  is the Coriolis term and can be written as: ( )B B B B qw rv S V V ru

Phase Fluctuations and a Negative U Hubbard Model: Single-Particle and Thermodyanic Properties in a Conserving Approximation

NASA Astrophysics Data System (ADS)

Serene, J. W.; Deisz, J. J.; Hess, D. W.

1997-03-01

Calculations performed in the fluctuation exchange approximation for the single-band 2D Hubbard model on a cylinder and threaded by a flux, show the appearance of a finite superfluid density below T ~ 0.13t, for U=-4t and at three-eighths filling.(J.J. Deisz, D.W. Hess, Bull. Am. Phys. Soc. 41, 239 (1996); J.J. Deisz, D.W. Hess, and J.W. Serene, in preparation.) We show the evolution, with decreasing temperature, of the single-particle spectral function, the self-energy, the particle-particle T-matrix, and thermodynamic properties as the superfluid state is approached and entered.

Innovative Seismic Array Analysis for Studies of Wave Propagation in the Earth

DTIC Science & Technology

1999-04-30

station signal power can be written as 0.5 - 3.5 Hz. 2.0 -14.0 Hz. Pmg(f,t,u) = \\d\\ 2-tr[C(f,t,u)], (6) where tr is the trace of...the matrix and d is an A^ X 1 vector N of station weights such that 2 d„ = 1. We will be using uniform weighting such that d„ = \\IN. The power of... stations SEH, SWH, and NH. Wpw 2 ukm{ uk , Uj) X m( uk , Uj) ( uk , Uj) &4 (9) where m( uk , Uj) 0 S(f, t, uk , M,.) < 0.9Speak (/, t)f S(f,

Urinary Collagen Fragments Are Significantly Altered in Diabetes: A Link to Pathophysiology

PubMed Central

Argilés, Àngel; Cerna, Marie; Delles, Christian; Dominiczak, Anna F.; Gayrard, Nathalie; Iphöfer, Alexander; Jänsch, Lothar; Jerums, George; Medek, Karel; Mischak, Harald; Navis, Gerjan J.; Roob, Johannes M.; Rossing, Kasper; Rossing, Peter; Rychlík, Ivan; Schiffer, Eric; Schmieder, Roland E.; Wascher, Thomas C.; Winklhofer-Roob, Brigitte M.; Zimmerli, Lukas U.; Zürbig, Petra; Snell-Bergeon, Janet K.

2010-01-01

Background The pathogenesis of diabetes mellitus (DM) is variable, comprising different inflammatory and immune responses. Proteome analysis holds the promise of delivering insight into the pathophysiological changes associated with diabetes. Recently, we identified and validated urinary proteomics biomarkers for diabetes. Based on these initial findings, we aimed to further validate urinary proteomics biomarkers specific for diabetes in general, and particularity associated with either type 1 (T1D) or type 2 diabetes (T2D). Methodology/Principal Findings Therefore, the low-molecular-weight urinary proteome of 902 subjects from 10 different centers, 315 controls and 587 patients with T1D (n = 299) or T2D (n = 288), was analyzed using capillary-electrophoresis mass-spectrometry. The 261 urinary biomarkers (100 were sequenced) previously discovered in 205 subjects were validated in an additional 697 subjects to distinguish DM subjects (n = 382) from control subjects (n = 315) with 94% (95% CI: 92–95) accuracy in this study. To identify biomarkers that differentiate T1D from T2D, a subset of normoalbuminuric patients with T1D (n = 68) and T2D (n = 42) was employed, enabling identification of 131 biomarker candidates (40 were sequenced) differentially regulated between T1D and T2D. These biomarkers distinguished T1D from T2D in an independent validation set of normoalbuminuric patients (n = 108) with 88% (95% CI: 81–94%) accuracy, and in patients with impaired renal function (n = 369) with 85% (95% CI: 81–88%) accuracy. Specific collagen fragments were associated with diabetes and type of diabetes indicating changes in collagen turnover and extracellular matrix as one hallmark of the molecular pathophysiology of diabetes. Additional biomarkers including inflammatory processes and pro-thrombotic alterations were observed. Conclusions/Significance These findings, based on the largest proteomic study performed to date on subjects with DM, validate the previously described biomarkers for DM, and pinpoint differences in the urinary proteome of T1D and T2D, indicating significant differences in extracellular matrix remodeling. PMID:20927192

Optically transparent semiconducting polymer nanonetwork for flexible and transparent electronics

PubMed Central

Yu, Kilho; Park, Byoungwook; Kim, Geunjin; Kim, Chang-Hyun; Park, Sungjun; Kim, Jehan; Jung, Suhyun; Jeong, Soyeong; Kwon, Sooncheol; Kang, Hongkyu; Kim, Junghwan; Yoon, Myung-Han; Lee, Kwanghee

2016-01-01

Simultaneously achieving high optical transparency and excellent charge mobility in semiconducting polymers has presented a challenge for the application of these materials in future “flexible” and “transparent” electronics (FTEs). Here, by blending only a small amount (∼15 wt %) of a diketopyrrolopyrrole-based semiconducting polymer (DPP2T) into an inert polystyrene (PS) matrix, we introduce a polymer blend system that demonstrates both high field-effect transistor (FET) mobility and excellent optical transparency that approaches 100%. We discover that in a PS matrix, DPP2T forms a web-like, continuously connected nanonetwork that spreads throughout the thin film and provides highly efficient 2D charge pathways through extended intrachain conjugation. The remarkable physical properties achieved using our approach enable us to develop prototype high-performance FTE devices, including colorless all-polymer FET arrays and fully transparent FET-integrated polymer light-emitting diodes. PMID:27911774

3D study of intermetallics and their effect on the corrosion morphology of rheocast aluminium alloy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mingo, B.; Arrabal, R., E-mail: rarrabal@ucm.es; Pardo, A.

In the present study, the effect of heat treatment T6.1 on the microstructure and corrosion behaviour of rheocast aluminium alloy A356 is investigated on the basis of 2D/3D characterization techniques and electrochemical and SKPFM measurements. Heat treatment strengthens the α-Al matrix, modifies the intermetallic particles and spheroidizes eutectic Si. These changes do not modify significantly the corrosion behaviour of the alloy. 3D SEM-Tomography clearly shows that the corrosion advances in the shape of narrow paths between closely spaced intermetallics without a major influence of eutectic Si. - Highlights: • T6.1 spheroidizes Si, strengthens the matrix and modifies the intermetallics. •more » Electrochemical behaviour of untreated and heat-treated alloys is similar. • 3D SEM-Tomography provides additional information on the corrosion morphology. • Corrosion advances as paths between intermetallics with little influence of Si.« less

Halogen atom effect on the photophysical properties of substituted aza-BODIPY derivatives.

PubMed

De Simone, B C; Mazzone, G; Pirillo, J; Russo, N; Sicilia, E

2017-01-18

The influence of halogen atom substitution (Br and I), in different amounts and positions in an aza-BODIPY skeleton, on the photophysical properties of some aza-BODIPY derivatives has been investigated by using density functional theory and its time-dependent extension. The heavy atom effect on excitation energies, singlet-triplet energy gaps and spin-orbit matrix elements has been considered. The maximum absorption within the therapeutic window has been confirmed for all the aza-BODIPY derivatives. The feasible intersystem spin crossing pathways for the population of the lowest triplet state, that will depend on the values of the spin-orbit matrix elements, the energy gap as well as the orbital composition of the involved states have been found to most likely involve the S 1 and T 1 or T 2 states. The outcomes of computations support the potential therapeutic use of these compounds as photosensitizers in photodynamic therapy.

Damped transverse oscillations of interacting coronal loops

NASA Astrophysics Data System (ADS)

Soler, Roberto; Luna, Manuel

2015-10-01

Damped transverse oscillations of magnetic loops are routinely observed in the solar corona. This phenomenon is interpreted as standing kink magnetohydrodynamic waves, which are damped by resonant absorption owing to plasma inhomogeneity across the magnetic field. The periods and damping times of these oscillations can be used to probe the physical conditions of the coronal medium. Some observations suggest that interaction between neighboring oscillating loops in an active region may be important and can modify the properties of the oscillations. Here we theoretically investigate resonantly damped transverse oscillations of interacting nonuniform coronal loops. We provide a semi-analytic method, based on the T-matrix theory of scattering, to compute the frequencies and damping rates of collective oscillations of an arbitrary configuration of parallel cylindrical loops. The effect of resonant damping is included in the T-matrix scheme in the thin boundary approximation. Analytic and numerical results in the specific case of two interacting loops are given as an application.

A model for cell migration in non-isotropic fibrin networks with an application to pancreatic tumor islets.

PubMed

Chen, Jiao; Weihs, Daphne; Vermolen, Fred J

2018-04-01

Cell migration, known as an orchestrated movement of cells, is crucially important for wound healing, tumor growth, immune response as well as other biomedical processes. This paper presents a cell-based model to describe cell migration in non-isotropic fibrin networks around pancreatic tumor islets. This migration is determined by the mechanical strain energy density as well as cytokines-driven chemotaxis. Cell displacement is modeled by solving a large system of ordinary stochastic differential equations where the stochastic parts result from random walk. The stochastic differential equations are solved by the use of the classical Euler-Maruyama method. In this paper, the influence of anisotropic stromal extracellular matrix in pancreatic tumor islets on T-lymphocytes migration in different immune systems is investigated. As a result, tumor peripheral stromal extracellular matrix impedes the immune response of T-lymphocytes through changing direction of their migration.

Properties and Residual Stresses in Angle-Ply Polymer Matrix Composites

DTIC Science & Technology

1982-03-01

AMMRC TR 82-12 PROPERTIES AND RES l DUAL STRESSES IN ANGLE-PLY POLYMER MATR l X COMPOSITES March 1982 ABDEL A. FAHMY,, HARVEY A. WEST, and MARK...m D.e. Enl.r.d) PROPERTIES AND RESIDUAL STRESSES I N ANGLE-PLY F i n a l Report POLYMER MATRIX COMPOSITES REPORTDOCUMENTATlON PAGE I 7. AUTHOR...SUPPLEMENTARV NOTES L 19. KEY WORDS (Comclrm. m r.r.r. wd. 11 ner..sw and idenllfy by blocb nmb-r) Composites Thermal expansion Epoxy l a m i n a t e s

Application of Composite Materials to Truck Components: Leaf Springs and Propeller Shafts for 5-Ton Trucks

DTIC Science & Technology

1981-11-01

Fiberglass-Epoxy Resin Matrix Composites 2(L ABSTRACT (Caautlrue am reverse de bf IHI wee•a’y d Identify by block number) The objective of the program was to...Army truck are designed using resin matrix composite materials. Both design studies and prototype fabrication and testing are included in the program...For the leaf springs (both front and rear) a hybrid design using steel DD FOR 143 ED#T1ON OF I NOV65 IS OBSOLETE SECURITY CLASSIFICATION OF THIS PAGE

Effects of ΛΛ ‑ ΞN mixing in the decay of {}_{{\\rm{\\Lambda }}{\\rm{\\Lambda }}}{}^{6}{\\rm{H}}{\\rm{e}}

NASA Astrophysics Data System (ADS)

Maneu, J.; Parreño, A.; Ramos, A.

2018-05-01

A one-meson exchange model including the ground state of the pseudoscalar octet is used to describe the weak two-body interactions responsible for the decay of {}{{Λ }{{Λ }}}{}6{{H}}{{e}}. Strong interaction effects are taken into account by a microscopic study based on the solution of G-matrix and T-matrix equations for the initial and final interacting pairs respectively. Results for the decay induced by {{Λ }}{{Λ }}\\to {{Λ }}N({{Σ }}N) transitions are given.

Transactions of the Conference on Applied Mathematics and Computing (9th) Held in Minneapolis, Minnesota on 18-21 June 1991

DTIC Science & Technology

1992-03-01

the ith row of I<. The preconditioned matrix K is thus a stochastic matrix, and by the Perron - Frobenius theorem (e.g., Horn and Johnson, 1989), K...now be determined. For equations (10) and (11) to be real, the radical must be nonnegative . This condition on d defines the index zero threshold...ddhsi: sfl] [r;I,r;I] . Since h/lh is positive-definite, (3.2) shows that a , and 13, are nonnegative . This fact can be used t~ test a candidates

Improving the interlaminar shear strength of carbon fiber-epoxy composites through carbon fiber bromination

NASA Technical Reports Server (NTRS)

Jaworske, Donald A.; Maciag, Carolyn

1987-01-01

The use of bromine to improve the interlaminar shear strength of PAN-based carbon fibers was investigated. Composite test specimens fabicated from brominated T-300 fibers and a MY720 matrix exhibited on average a 30% improvement in ILSS over their pristine counterparts. Mass, electrical resistivity, density, contact angle, and scanning Auger microscopy results suggested a mechanism in which the bromine was covalently bonded to the surface of the fiber, and this resulted in an increased van der Waal's adhesion between fiber and matrix.

Double Cantilever Beam Fracture Toughness Testing of Several Composite Materials

NASA Technical Reports Server (NTRS)

Kessler, Jeff A.; Adams, Donald F.

1992-01-01

Double-cantilever beam fracture toughness tests were performed by the Composite Materials Research Group on several different unidirectional composite materials provided by NASA Langley Research Center. The composite materials consisted of Hercules IM-7 carbon fiber and various matrix resin formulations. Multiple formulations of four different families of matrix resins were tested: LaRC - ITPI, LaRC - IA, RPT46T, and RP67/RP55. Report presents the materials tested and pertinent details supplied by NASA. For each material, three replicate specimens were tested. Multiple crack extensions were performed on each replicate.

Antisymmetric Wilson loops in N = 4 SYM beyond the planar limit

NASA Astrophysics Data System (ADS)

Gordon, James

2018-01-01

We study the 1/2 -BPS circular Wilson loop in the totally antisymmetric representation of the gauge group in N = 4 supersymmetric Yang-Mills. This observable is captured by a Gaussian matrix model with appropriate insertion. We compute the first 1 /N correction at leading order in 't Hooft coupling by means of the matrix model loop equations. Disagreement with the 1-loop effective action of the holographically dual D5-brane suggests the need to account for gravitational backreaction on the string theory side.

A Digital Algorithm for Composite Laminate Analysis - FORTRAN. Revision

DTIC Science & Technology

1983-10-01

Addition of a matrix to a scalar multiple of another matrix; C = A + Con x B, Con is scalar 16. MTDM : Translates material properties to each ply 17...1) IF(LI eLT. 8) READ 706,TH(l) NNL=1 LMPI C1)=LI PLNM(1 )1. CALL MTDM (PLNMPMGMPMITPI) CALL MODULS(ES11C1),ES22C1),VS12(1) ,GS12(1),QU) CALL...NNLNLDCNTHLMPIDTCPLNM) CALL MTDM (PLNMPMGMtPMITPI) CALL MOLS(THHLHS) CALL INVRSCSB19A) CALL MTAD(ZEROADUMH) CALL MTAD(ZEROSB1,tDUM1,PHI) CALL NORM

Three Dimensional Orbital Stability About the Earth-Moon Equilateral Libration Points.

DTIC Science & Technology

1980-12-01

need to be rotated to the ecliptic . If e is the obliquity of the ecliptic , then the transformation matrix for this is: t F e, ’ C]u 11E -12 IF I) I...the use of the above transformation matrix. The frame for the analysis of the problem will be an Earth-centered ecliptic nonrotating rectangular system...The X-axis will point toward the vernal equinox and the Z-axis will be perpendicular to the ecliptic having the XY-plane coincident with the ecliptic

Bibliography on Ceramic Matrix Composites and Reinforcing Whiskers, Platelets, and Fibers, 1970-1990

DTIC Science & Technology

1993-08-01

Ballistic A Study of the Critical Factors Controlling the Impact on Three Composite Ceramics Synthesis of Ceramic Matrix Composites from Snedeker, R. S...1.2.1.55 1.22.2 Mechanical and Structural Characterize’ion of Oxidation Kinetics of Silicon Carbide Whiskers the Nicalon Silicon Carbide Fibre Studied by X...Powders and Whiskers: An XPS Study 9 (10), 1218-20, Oct 1990 Taylor, T. N. (AD D250 694) J. Mater. Res. 4 (1), 189-203, Jan-Feb 1989 1.2.2.11 (AD D250 571

Evidence for an impact-induced magnetic fabric in Allende, and exogenous alternatives to the core dynamo theory for Allende magnetization

NASA Astrophysics Data System (ADS)

Muxworthy, Adrian R.; Bland, Phillip A.; Davison, Thomas M.; Moore, James; Collins, Gareth S.; Ciesla, Fred J.

2017-10-01

We conducted a paleomagnetic study of the matrix of Allende CV3 chondritic meteorite, isolating the matrix's primary remanent magnetization, measuring its magnetic fabric and estimating the ancient magnetic field intensity. A strong planar magnetic fabric was identified; the remanent magnetization of the matrix was aligned within this plane, suggesting a mechanism relating the magnetic fabric and remanence. The intensity of the matrix's remanent magnetization was found to be consistent and low ( 6 μT). The primary magnetic mineral was found to be pyrrhotite. Given the thermal history of Allende, we conclude that the remanent magnetization was formed during or after an impact event. Recent mesoscale impact modeling, where chondrules and matrix are resolved, has shown that low-velocity collisions can generate significant matrix temperatures, as pore-space compaction attenuates shock energy and dramatically increases the amount of heating. Nonporous chondrules are unaffected, and act as heat-sinks, so matrix temperature excursions are brief. We extend this work to model Allende, and show that a 1 km/s planar impact generates bulk porosity, matrix porosity, and fabric in our target that match the observed values. Bimodal mixtures of a highly porous matrix and nominally zero-porosity chondrules make chondrites uniquely capable of recording transient or unstable fields. Targets that have uniform porosity, e.g., terrestrial impact craters, will not record transient or unstable fields. Rather than a core dynamo, it is therefore possible that the origin of the magnetic field in Allende was the impact itself, or a nebula field recorded during transient impact heating.

Size effects in electrical and magnetic properties of quasi-one-dimensional tin wires in asbestos

NASA Astrophysics Data System (ADS)

Chernyaev, A. V.; Shamshur, D. V.; Fokin, A. V.; Kalmykov, A. E.; Kumzerov, Yu. A.; Sorokin, L. M.; Parfen'ev, R. V.; Lashkul, A.

2016-03-01

Bulk composites have been prepared based on one-dimensional fibers of natural chrisothil-asbestos with various internal diameters ( d = 6-2.5 nm) filled with tin. The electrical and magnetic properties of quasi-one-dimensional Sn wires have been studied at low temperatures. The electrical properties have been measured at T = 300 K at a pressure P = 10 kbar. It has been found that the superconducting (SC) characteristics of the nanocomposites (critical temperature T c and critical magnetic field H c) increase as the Sn filament diameter decreases. The temperature spreading of the resistive SC transition also increases as the Sn filament diameter decreases, which is explained by the SC order parameter fluctuations. The size effects (the increase in critical temperature T c and transition width Δ T c) in Sn nanofilaments are well described by the independent Aslamazov-Larkin and Langer-Ambegaokara fluctuation theories, which makes it possible to find the dependence of T c of the diffuse SC transition on the nanowire diameter. Using the temperature and magnetic-field dependences of the magnetic moment M( T, H), it has been found that the superconductor-normal metal phase diagram of the Sn-asbestos nanocomposite has a wider region of the SC state in T and H as compared to the data for bulk Sn. The magnetic properties of chrisotil-asbestos fibers unfilled with Sn have been studied. It has been found that the Curie law is fulfilled and that the superparamagnetism is absent in such samples. The obtained results indicate the absence of magnetically ordered impurities (magnetite) in the chrisotil-asbestos matrix, which allowed one to not consider the problem of the interaction of the magnetic subsystem of the asbestos matrix and the superconducting subsystem of Sn nanowires.

Caveolin-1 mediates tissue plasminogen activator-induced MMP-9 up-regulation in cultured brain microvascular endothelial cells.

PubMed

Jin, Xinchun; Sun, Yanyun; Xu, Ji; Liu, Wenlan

2015-03-01

Thrombolysis with tissue plasminogen activator (tPA) increases matrix metalloproteinase-9 (MMP-9) activity in the ischemic brain, which exacerbates blood-brain barrier injury and increases the risk of symptomatic cerebral hemorrhage. The mechanism through which tPA enhances MMP-9 activity is not well understood. Here we report an important role of caveolin-1 in mediating tPA-induced MMP-9 synthesis. Brain microvascular endothelial cell line bEnd3 cells were incubated with 5 or 20 μg/ml tPA for 24 hrs before analyzing MMP-9 levels in the conditioned media and cellular extracts by gelatin zymography. tPA at a dose of 20 μg/mL tPA, but not 5 μg/mL, significantly increased MMP-9 level in cultured media while decreasing it in cellular extracts. Concurrently, tPA treatment induced a 2.3-fold increase of caveolin-1 protein levels in endothelial cells. Interestingly, knockdown of Cav-1 with siRNA inhibited tPA-induced MMP-9 mRNA up-regulation and MMP-9 increase in the conditioned media, but did not affect MMP-9 decrease in cellular extracts. These results suggest that caveolin-1 critically contributes to tPA-mediated MMP-9 up-regulation, but may not facilitate MMP-9 secretion in endothelial cells. Thrombolysis with tissue plasminogen activator (tPA) increases matrix metalloproteinase-9 (MMP-9) activity in the ischemic brain, which exacerbates ischemic blood brain barrier (BBB) injury and increases the risk of symptomatic cerebral hemorrhage. Our results suggest a novel mechanism underlying this tPA-MMP 9 axis. In response to tPA treatment, caveolin-1 protein levels increased in endothelial cells, which mediate MMP-9 mRNA up-regulation and its secretion into extracellular space. Caveolin-1 may, however, not facilitate MMP-9 secretion in endothelial cells. Our data suggest caveolin-1 as a novel therapeutic target for protecting the BBB against ischemic damage. The schematic outlines tPA-induced MMP-9 upreguation. © 2015 International Society for Neurochemistry.

Accurate prediction of bacterial type IV secreted effectors using amino acid composition and PSSM profiles.

PubMed

Zou, Lingyun; Nan, Chonghan; Hu, Fuquan

2013-12-15

Various human pathogens secret effector proteins into hosts cells via the type IV secretion system (T4SS). These proteins play important roles in the interaction between bacteria and hosts. Computational methods for T4SS effector prediction have been developed for screening experimental targets in several isolated bacterial species; however, widely applicable prediction approaches are still unavailable In this work, four types of distinctive features, namely, amino acid composition, dipeptide composition, .position-specific scoring matrix composition and auto covariance transformation of position-specific scoring matrix, were calculated from primary sequences. A classifier, T4EffPred, was developed using the support vector machine with these features and their different combinations for effector prediction. Various theoretical tests were performed in a newly established dataset, and the results were measured with four indexes. We demonstrated that T4EffPred can discriminate IVA and IVB effectors in benchmark datasets with positive rates of 76.7% and 89.7%, respectively. The overall accuracy of 95.9% shows that the present method is accurate for distinguishing the T4SS effector in unidentified sequences. A classifier ensemble was designed to synthesize all single classifiers. Notable performance improvement was observed using this ensemble system in benchmark tests. To demonstrate the model's application, a genome-scale prediction of effectors was performed in Bartonella henselae, an important zoonotic pathogen. A number of putative candidates were distinguished. A web server implementing the prediction method and the source code are both available at http://bioinfo.tmmu.edu.cn/T4EffPred.

Comparative Oral Absorption of Curcumin in a Natural Turmeric Matrix with Two Other Curcumin Formulations: An Open-label Parallel-arm Study.

PubMed

Gopi, Sreeraj; Jacob, Joby; Varma, Karthik; Jude, Shintu; Amalraj, Augustine; Arundhathy, C A; George, Robin; Sreeraj, T R; Divya, C; Kunnumakkara, Ajaikumar B; Stohs, Sidney J

2017-12-01

Curcuminoids are the major bioactive molecules in turmeric, and poor bioavailability deters them from being the major components of many health and wellness applications. This study was conducted to assess the bioavailability of a completely natural turmeric matrix formulation (CNTMF) and compare its bioavailability with two other commercially available formulations, namely, curcumin with volatile oil (volatile oil formulation) and curcumin with phospholipids and cellulose (phospholipid formulation) in healthy human adult male subjects (15 each group) under fasting conditions. Each formulation was administrated orally as a single 500-mg dose in capsule form, and blood samples were analyzed by liquid chromatography mass spectrometry at various time intervals up to 24 h. The ingestion of the CNTMF was very well absorbed and resulted in a mean curcuminoids plasma C max of 170.14 ng/mL (T max  = 4 h) compared with 47.54 ng/mL and 69.63 ng/mL for the volatile oil (T max  = 3 h) and phospholipid (T max  = 2.25 h) formulations, respectively. The extent of absorption of total curcuminoids in the blood for the CNTMF was 6× greater than volatile oil formulation and 5× greater than phospholipids formulation. The results of this study indicate that curcumin in a natural turmeric matrix exhibited greater bioavailability than the two comparator products. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

Thread-Level Parallelization and Optimization of NWChem for the Intel MIC Architecture

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shan, Hongzhang; Williams, Samuel; Jong, Wibe de

In the multicore era it was possible to exploit the increase in on-chip parallelism by simply running multiple MPI processes per chip. Unfortunately, manycore processors' greatly increased thread- and data-level parallelism coupled with a reduced memory capacity demand an altogether different approach. In this paper we explore augmenting two NWChem modules, triples correction of the CCSD(T) and Fock matrix construction, with OpenMP in order that they might run efficiently on future manycore architectures. As the next NERSC machine will be a self-hosted Intel MIC (Xeon Phi) based supercomputer, we leverage an existing MIC testbed at NERSC to evaluate our experiments.more » In order to proxy the fact that future MIC machines will not have a host processor, we run all of our experiments in tt native mode. We found that while straightforward application of OpenMP to the deep loop nests associated with the tensor contractions of CCSD(T) was sufficient in attaining high performance, significant effort was required to safely and efficiently thread the TEXAS integral package when constructing the Fock matrix. Ultimately, our new MPI OpenMP hybrid implementations attain up to 65x better performance for the triples part of the CCSD(T) due in large part to the fact that the limited on-card memory limits the existing MPI implementation to a single process per card. Additionally, we obtain up to 1.6x better performance on Fock matrix constructions when compared with the best MPI implementations running multiple processes per card.« less

Thread-level parallelization and optimization of NWChem for the Intel MIC architecture

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shan, Hongzhang; Williams, Samuel; de Jong, Wibe

In the multicore era it was possible to exploit the increase in on-chip parallelism by simply running multiple MPI processes per chip. Unfortunately, manycore processors' greatly increased thread- and data-level parallelism coupled with a reduced memory capacity demand an altogether different approach. In this paper we explore augmenting two NWChem modules, triples correction of the CCSD(T) and Fock matrix construction, with OpenMP in order that they might run efficiently on future manycore architectures. As the next NERSC machine will be a self-hosted Intel MIC (Xeon Phi) based supercomputer, we leverage an existing MIC testbed at NERSC to evaluate our experiments.more » In order to proxy the fact that future MIC machines will not have a host processor, we run all of our experiments in native mode. We found that while straightforward application of OpenMP to the deep loop nests associated with the tensor contractions of CCSD(T) was sufficient in attaining high performance, significant e ort was required to safely and efeciently thread the TEXAS integral package when constructing the Fock matrix. Ultimately, our new MPI+OpenMP hybrid implementations attain up to 65× better performance for the triples part of the CCSD(T) due in large part to the fact that the limited on-card memory limits the existing MPI implementation to a single process per card. Additionally, we obtain up to 1.6× better performance on Fock matrix constructions when compared with the best MPI implementations running multiple processes per card.« less

Measurement of differential cross sections and spin density matrix elements along with a partial wave analysis for gammap → po using CLAS at Jefferson Lab

NASA Astrophysics Data System (ADS)

Williams, Mike

This work presents measurements of differential cross sections, dsigma/dcos qwCM , and spin density matrix elements, r0MM' , for the reaction gammap → po in the energy range 1.72 GeV< s <2.84 GeV. The data were collected at Jefferson Lab, using the CLAS detector, as part of the g11a run period in 2004. Our r0MM' measurements vastly increase the precision of the world's data and extend the large angle measurements by over 400 MeV in s . Our data confirms that for s < 2.1 GeV, the forward angle (small |t|) production amplitude is dominated by t-channel pi0 exchange. At higher energies, existing non-resonant models do a poor job of describing our data. In particular, u-channel models fail to reproduce our highest energy backwards r0MM' measurements. A mass-independent partial wave analysis has also been performed. Near threshold, the dominant resonance contributions extracted are the **** F15 (1680) and *** D 13(1700). Together with the t-channel pi0 exchange, these three waves provide a remarkably good description of our differential cross section and spin density matrix element measurements for s < 2 GeV. Strong, but not conclusive, evidence for the **** G17(2190) has also been extracted. Improved non-resonant models may be necessary to irrefutably show whether this state contributes to o photoproduction. Evidence for missing resonances is suggestive, but inconclusive without theoretical input.

Black rice (Oryza sativa L.) extract modulates ultraviolet-induced expression of matrix metalloproteinases and procollagen in a skin cell model.

PubMed

Han, Mira; Bae, Jung-Soo; Ban, Jae-Jun; Shin, Hee Soon; Lee, Dong Hun; Chung, Jin Ho

2018-05-01

Exposure of the skin to ultraviolet (UV) radiation causes extracellular matrix (ECM) collapse in the dermis, owing to an increase in matrix metalloproteinase (MMP) production in both the epidermis and dermis, and a decrease in type I collagen expression in the dermis. Recently, black rice (Oryza sativa L.) was reported to have a wide range of pharmacological effects in various settings. However, the effects of black rice extract (BRE) on UV‑irradiated skin cells have not yet been characterized. BRE treatment did not affect cell morphology and viability of HaCaT and human dermal fibroblasts (HDF). We demonstrated that BRE downregulated basal and UV‑induced MMP‑1 expression in HaCaT cells. Furthermore, BRE significantly increased type I procollagen expression, and decreased MMP‑1 and MMP‑3 expression in UV‑irradiated HDF. The underlying mechanisms of these results involve a decrease in p38 and c‑Jun N‑terminal kinase activity, and suppression of UV‑induced activation of activator protein‑1 (AP‑1). BRE reduced UV‑induced reactive oxygen species production in HaCaT cells in a dose‑dependent manner. Indeed, mass spectrometry revealed that BRE contained antioxidative flavonoid components such as cyanidin‑3‑O‑β‑D‑glycoside and taxifolin‑7‑O‑glucoside. These findings suggest that BRE attenuates UV‑induced ECM damage by modulating mitogen‑activated protein kinase and AP‑1 signaling, and could be used as an active ingredient for preventing photoaging of the skin.

Matrix metalloproteinase-7 expression in gastric carcinoma.

PubMed Central

Honda, M; Mori, M; Ueo, H; Sugimachi, K; Akiyoshi, T

1996-01-01

BACKGROUND/AIMS: Matrix metalloproteinase-7 (MMP-7) belongs to the same family as matrix degrading metalloproteinase (MMPs) that may play an important part in cancer cell invasion and metastasis. This study reports on the MMP-7 mRNA expression level both in human gastric carcinomas and the normal gastric mucosa. METHODS: From fresh specimens of 47 surgical pairs of primary gastric carcinomas and corresponding normal tissue specimens, cDNA was obtained by reverse transcription (RT) and thereafter MMP-7 mRNAs were detected by means of a polymerase chain reaction. The tumour/normal (T/N) ratio of MMP-7 expression was calculated after correcting for glyceraldehyde-3-phosphate dehydrogenase as an internal control. RESULTS: The expression corrected levels of MMP-7 mRNA of the tumour was greater than that of the normal mucosa in 41 of 47 cases (87%). The 13 cases whose T/N ratio was more than 2.1 showed a deeper invasion of the gastric wall, and more frequent lymphatic or vascular permeations than the 34 cases whose T/N ratio was less than 2.0. An immunohistochemical study showed that MMP-7 was predominantly expressed in the cancer cells, weakly expressed in normal epithelial cells, and not expressed in the surrounding stromal cells. CONCLUSIONS: These findings suggest that the overexpression of MMP-7 may thus play an important part in tumour invasion in gastric carcinomas while, in addition, MMP-7 may also prove to be a useful marker for determining the biological aggressiveness of gastric carcinoma. Images Figure 1 Figure 2 Figure 3 PMID:8949652

Association of functional MMP-2 gene variant with intracranial aneurysms: case-control genetic association study and meta-analysis.

PubMed

Alg, Varinder S; Ke, Xiayi; Grieve, Joan; Bonner, Stephen; Walsh, Daniel C; Bulters, Diederik; Kitchen, Neil; Houlden, Henry; Werring, David J

2018-01-15

Abnormalities in Matrix Metalloproteinase (MMP) genes, which are important in extracellular matrix (ECM) maintenance and therefore arterial wall integrity are a plausible underlying mechanism of intracranial aneurysm (IA) formation, growth and subsequent rupture. We investigated whether the rs243865 C > T SNP (single nucleotide polymorphism) within the MMP-2 gene (which influences gene transcription) is associated with IA compared to matched controls. We conducted a case-control genetic association study, adjusted for known IA risk factors (smoking and hypertension), in a UK Caucasian population of 1409 patients with intracranial aneurysms (IA), and 1290 matched controls, to determine the association of the rs243865 C > T functional MMP-2 gene SNP with IA (overall, and classified as ruptured and unruptured). We also undertook a meta-analysis of two previous studies examining this SNP. The rs243865 T allele was associated with IA presence in univariate (OR 1.18 [95% CI 1.04-1.33], p = .01) and in multi-variable analyses adjusted for smoking and hypertension status (OR 1.16 [95% CI 1.01-1.35], p = .042). Subgroup analysis demonstrated an association of the rs243865 SNP with ruptured IA (OR 1.18 [95% CI 1.03-1.34] p = .017), but, not unruptured IA (OR 1.17 [95% CI 0.97-1.42], p = .11). Our study demonstrated an association between the functional MMP-2 rs243865 variant and IAs. Our findings suggest a genetic role for altered extracellular matrix integrity in the pathogenesis of IA development and rupture.

Mixed-matrix membranes with enhanced antifouling activity: probing the surface-tailoring potential of Tiron and chromotropic acid for nano-TiO2.

PubMed

Pal, Avishek; Dey, T K; Debnath, A K; Bhushan, Bharat; Sahu, A K; Bindal, R C; Kar, Soumitra

2017-09-01

Mixed-matrix membranes (MMMs) were developed by impregnating organofunctionalized nanoadditives within fouling-susceptible polysulfone matrix following the non-solvent induced phase separation (NIPS) method. The facile functionalization of nanoparticles of anatase TiO 2 (nano-TiO 2 ) by using two different organoligands, viz . Tiron and chromotropic acid, was carried out to obtain organofunctionalized nanoadditives, F T -nano-TiO 2 and F C -nano-TiO 2 , respectively. The structural features of nanoadditives were evaluated by X-ray diffraction, X-ray photoelectron spectroscopy, Raman and Fourier transform infrared spectroscopy, which established that Tiron leads to the blending of chelating and bridging bidentate geometries for F T -nano-TiO 2 , whereas chromotropic acid produces bridging bidentate as well as monodentate geometries for F C -nano-TiO 2 . The surface chemistry of the studied membranes, polysulfone (Psf): F T -nano-TiO 2 UF and Psf: F C -nano-TiO 2 UF, was profoundly influenced by the benign distributions of the nanoadditives enriched with distinctly charged sites ([Formula: see text]), as evidenced by superior morphology, improved topography, enhanced surface hydrophilicity and altered electrokinetic features. The membranes exhibited enhanced solvent throughputs, viz . 3500-4000 and 3400-4300 LMD at 1 bar of transmembrane pressure, without significant compromise in their rejection attributes. The flux recovery ratios and fouling resistive behaviours of MMMs towards bovine serum albumin indicated that the nanoadditives could impart stable and appreciable antifouling activity, potentially aiding in a sustainable ultrafiltration performance.

On-line observation of cell growth in a three-dimensional matrix on surface-modified microelectrode arrays.

PubMed

Lin, Shu-Ping; Kyriakides, Themis R; Chen, Jia-Jin J

2009-06-01

Despite many successful applications of microelectrode arrays (MEAs), typical two-dimensional in-vitro cultures do not project the full scale of the cell growth environment in the three-dimensional (3D) in-vivo setting. This study aims to on-line monitor in-vitro cell growth in a 3D matrix on the surface-modified MEAs with a dynamic perfusion culture system. A 3D matrix consisting of poly(ethylene glycol) hydrogel supplemented with poly-D-lysine was subsequently synthesized in situ on the self-assembled monolayer modified MEAs. FTIR spectrum analysis revealed a peak at 2100 cm(-1) due to the degradation of the structure of the 3D matrix. After 2 wks, microscopic examination revealed that the non-degraded area was around 1500 microm(2) and provided enough space for cell growth. Fluorescence microscopy revealed that the degraded 3D matrix was non-cytotoxic allowing the growth of NIH3T3 fibroblasts and cortical neurons in vitro. Time-course changes of total impedance including resistance and reactance were recorded for 8 days to evaluate the cell growth in the 3D matrix on the MEA. A consistent trend reflecting changes of reactance and total impedance was observed. These in-vitro assays demonstrate that our 3D matrix can construct a biomimetic system for cell growth and analysis of cell surface interactions.

The effects of simulated microgravity on cultured chicken embryonic chondrocytes

NASA Astrophysics Data System (ADS)

Zhang, X.; Li, X. B.; Yang, S. Z.; Li, S. G.; Jiang, P. D.; Lin, Z. H.

2003-10-01

Using the cultured chicken embryonic chondrocytes as a model, the effects of simulated microgravity on the microtubular system of the cellular skeleton, extracellular matrix, alkaline phosphatase activity, intracellular free calcium concentration and mitochondrial ATP synthase activity with its oligomycin inhibition rate were studied with a clinostat. The microtubular content was measured by a flow cytometer. The decrease of microtubular content showed the impairment of the cellular skeleton system. Observation on the extracellualr matrix by the scanning electron microscopy showed that it decreased significantly after rotating, and the fibers in the extracellular matrix were more tiny and disorderly than that of the control group. It can be concluded that the simulated microgravity can affect the secreting and assembly of the extracellular matrix. In contrast to the control, there was a time course decrease in alkaline phosphatase activity of chondrocytes, a marker of matrix mineralization. Meanwhile a significant drop in the intracellular calcium concentration happened at the beginning of rotation. These results indicate that simulated microgravity can suppress matrix calcification of cultured chondrocytes, and intracellular free calcium may be involved in the regulation of matrix calcification as the second signal transmitter. No significant changes happened in the mitochondrial ATP synthase activity and its oligomycin inhibition rate. Perhaps the energy metabolism wasn't affected by the simulated microgravity. The possible mechanisms about them were discussed.

On a Multiphase Multicomponent Model of Biofilm Growth

NASA Astrophysics Data System (ADS)

Friedman, Avner; Hu, Bei; Xue, Chuan

2014-01-01

Biofilms are formed when free-floating bacteria attach to a surface and secrete polysaccharide to form an extracellular polymeric matrix (EPS). A general model of biofilm growth needs to include the bacteria, the EPS, and the solvent within the biofilm region Ω( t), and the solvent in the surrounding region D( t). The interface between the two regions, Γ( t), is a free boundary. In this paper, we consider a mathematical model that consists of a Stokes equation for the EPS with bacteria attached to it, a Stokes equation for the solvent in Ω( t) and another for the solvent in D( t). The volume fraction of the EPS is another unknown satisfying a reaction-diffusion equation. The entire system is coupled nonlinearly within Ω( t) and across the free surface Γ( t). We prove the existence and uniqueness of a solution, with a smooth surface Γ( t), for a small time interval.

Data Migration Strategy and Information Assurance for the Business Enterprise Information Services

DTIC Science & Technology

2009-07-30

direct questions to me at (703) 601-5868 (DSN 329-5868). t ~a/J1~ Patricia A. Marsh, CPA Assistant Inspector General Defense Business Operations ...incrcment. Additionally, a Managemen t Control Matrix has been ~ubmillcd tor the BEIS FllrTlily o( System!! on an annual basis 6ince 2006. POg< l of4...including suggestions for reducing this burden, to Washington Headquarters Services, Directorate for Information Operations and Reports, 1215

Defense Technology Security Administration Strategic Plan 2009-2010

DTIC Science & Technology

2008-12-22

NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) Defense Technology Security Administration ( DTSA ),Washington,DC 8. PERFORMING ORGANIZATION...Security Administration This document is unclassifi ed in its entirety. Photography courtesy of Defense Link and DTSA . Document printed 2009. DTSA ...STRATEGIC PLAN 2009-2010 C O N T E N T S Message from the Director 2 Envisioning 2010 3 Our Way Ahead 5 We Are DTSA 18 Metrics Matrix 24 DTSA

Compact Feed Circuit with Quarter Wavelength Transmission Line Matrix Controlling Beams in Three Directions Including Boresight

NASA Astrophysics Data System (ADS)

Tsuji, Masatoshi

A compact feed circuit with a λ/4 transmission line matrix circuit for use in array antennas to control beams in three directions, including boresight, is presented. The feed circuit antenna is composed of five switches and λ/4 transmission lines, and the feeding matrix circuit yields phase differences of ±90° and 0°. The feed circuit can obtain a reliable output signal, as there is only a small degree of deviation of output signal with variations in the line width. The feed circuit is simulated, fabricated, and evaluated for ISM band, and the measured characteristics agree well with the results of the simulation. The size of feed circuit is 45 (H) × 48 (W) × 3 (T) mm.

Ne matrix spectra of the sym-C6Br3F3+ radical cation

USGS Publications Warehouse

Bondybey, V.E.; Sears, T.J.; Miller, T.A.; Vaughn, C.; English, J.H.; Shiley, R.S.

1981-01-01

The electronic absorption and laser excited, wavelength resolved fluorescence spectra of the title cation have been observed in solid Ne matrix and vibrationally analysed. The vibrational structure of the excited B2A2??? state shows close similarity to the parent compound. The X2E??? ground state structure is strongly perturbed and irregular owing to a large Jahn-Teller distortion. The data are analysed in terms of a recently developed, sophisticated multimode Jahn-Teller theoretical model. We have generated the sym-C6Br3F3+ cations in solid Ne matrix and obtained their wavelength resolved emission and absorption spectra. T ground electronic X2E??? state exhibits an irregular and strongly perturbed vibrational structure, which can be successfully modeled using sophisticated multimode Jahn-Teller theory. ?? 1981.

Neutrino nuclear responses for double beta decays and astro neutrinos by charge exchange reactions

NASA Astrophysics Data System (ADS)

Ejiri, Hiroyasu

2014-09-01

Neutrino nuclear responses are crucial for neutrino studies in nuclei. Charge exchange reactions (CER) are shown to be used to study charged current neutrino nuclear responses associated with double beta decays(DBD)and astro neutrino interactions. CERs to be used are high energy-resolution (He3 ,t) reactions at RCNP, photonuclear reactions via IAR at NewSUBARU and muon capture reactions at MUSIC RCNP and MLF J-PARC. The Gamow Teller (GT) strengths studied by CERs reproduce the observed 2 neutrino DBD matrix elements. The GT and spin dipole (SD) matrix elements are found to be reduced much due to the nucleon spin isospin correlations and the non-nucleonic (delta isobar) nuclear medium effects. Impacts of the reductions on the DBD matrix elements and astro neutrino interactions are discussed.

Evaluation of Water Content in Lumbar Intervertebral Discs and Facet Joints Before and After Physiological Loading Using T2 Mapping MRI.

PubMed

Yamabe, Daisuke; Murakami, Hideki; Chokan, Kou; Endo, Hirooki; Oikawa, Ryosuke; Sawamura, Shoitsu; Doita, Minoru

2017-12-15

T2 mapping was used to quantify the water content of lumbar spine intervertebral discs (IVDs) and facet joints before and after physiological loading. The aim of this study was to clarify the interaction between lumbar spine IVD and facet joints as load-bearing structures by measuring the water content of their matrix after physiological loading using T2 mapping magnetic resonance imaging (MRI). To date, few reports have functionally evaluated lumbar spine IVD and facet joints, and their interaction in vivo. T2 mapping may help detect changes in the water content of IVD and articular cartilage of facet joints before and after physiological loading, thereby enabling the evaluation of changes in interacted water retention between IVD and facet joints. Twenty asymptomatic volunteers (10 female and 10 male volunteers; mean age, 19.3 years; age range, 19-20 years) underwent MRI before and after physiological loading such as lumbar flexion, extension, and rotation. Each IVD from L1/2 to L5/S1 was sliced at center of the disc space, and the T2 value was measured at the nucleus pulposus (NP), anterior annulus fibrosus (AF), posterior AF, and bilateral facet joints. In the NP, T2 values significantly decreased after exercise at every lumbar spinal level. In the anterior AF, there were no significant differences in T2 values at any level. In the posterior AF, T2 values significantly increased only at L4/5. In the bilateral facet joints, T2 values significantly decreased after exercise at every level. There was a significant decrease in the water content of facet joints and the NP at every lumbar spinal level after dynamic loading by physical lumbar exercise. These changes appear to play an important and interactional role in the maintenance of the interstitial matrix in the IVD NP and cartilage in the facet joint. 3.

Effect of fiber reinforcement on thermo-oxidative stability and mechanical properties of polymer matrix composites

NASA Technical Reports Server (NTRS)

Bowles, K. J.

1992-01-01

A number of studies have investigated the thermooxidative behavior of polymer matrix composites. Two significant observations have been made from these research efforts: (1) fiber reinforcement has a significant effect on composite thermal stability; and (2) geometric effects must be considered when evaluating thermal aging data. The polyimide PMR-15 was the matrix material used in these studies. The control composite material was reinforced with Celion 6000 graphite fiber. T-4OR graphite fibers, along with some very stable ceramic fibers were selected as reinforcing fibers because of their high thermal stability. The ceramic fibers were Nicalon (silicon carbide) and Nextel 312 (alumina-silica-boron oxide). The mechanical properties of the two graphite fiber composites were significantly different, probably owing to variations in interfacial bonding between the fibers and the polyimide matrix. Three oxidation mechanisms were observed: (1) the preferential oxidation of the Celion 6000 fiber ends at cut surfaces, leaving a surface of matrix material with holes where the fiber ends were originally situated; (2) preferential oxidation of the composite matrix; and (3) interfacial degradation by oxidation. The latter two mechanisms were also observed on fiber end cut surfaces. The fiber and interface attacks appeared to initiate interfiber cracking along these surfaces.

Matrix metalloproteinase-9 expression and release from skin fibroblasts interacting with keratinocytes: Upregulation in response to sulphur mustard.

PubMed

Ries, Christian; Popp, Tanja; Egea, Virginia; Kehe, Kai; Jochum, Marianne

2009-09-01

Matrix metalloproteinases (MMPs), especially MMP-9 and MMP-2, degrade various proteins of the extracellular matrix, including collagen type IV the major component of basement membranes which also separate the epidermis from the dermis. Although previous work indicates the contribution of MMPs and their inhibitors (TIMPs) to the pathophysiology of skin lesions induced by the toxic chemical warefare agent sulphur mustard (SM), little is known about the underlying molecular and cellular mechanisms. In this study we demonstrate in a 3D-skin model that topical application of SM significantly upregulated basal MMP-9 mRNA expression and release from the cells as shown by qRT-PCR and zymography, whereas that of MMP-2, membrane-type 1 (MT1)-MMP, TIMP-1 and TIMP-2 remained almost unaffected by SM. Further studies in neonatal human dermal fibroblasts (NHDF) and HaCaT keratinocytes revealed that MMP-9 was not secreted from these cells, neither with or without exposure to SM. However, when NHDF and HaCaT were cocultivated, MMP-9 was expressed and released from the cell mixture, suggesting that interaction between both cell types is essential for MMP-9 production. Moreover, SM-treatment of NHDF/HaCaT cocultures further upregulated MMP-9 biosynthesis and secretion, which was consistent with our findings obtained in the 3D-skin model. Addition of conditioned medium derived from SM-exposed HaCaT cells to NHDF was able to stimulate MMP-9 secretion and also increased the migratory potential of NHDF as shown in a scratch-wound healing assay and a fluorescent cell invasion assay. In contrast, culture supernatants of SM-treated NHDF had not such an effect on HaCaT cells. Taken together, our findings provide first evidence that SM exposure of skin stimulates keratinocytes to release soluble factors which in turn induce enhanced MMP-9 secretion and invasiveness of fibroblasts in vitro. This provides a potential mechanism probably contributing to SM-evoked tissue injury in vivo.

Influence of formulation technique on acrylate methacrylate copolymer modified paracetamol matrix tablets.

PubMed

Cash-Torunarigha, Omonyemen Edoise; Eichie, Florence Egbomonjiade; Arhewoh, Matthew Ikhuoria

2015-03-01

This work was designed to evaluate the influence of various methods such as dry granulation (DG), wet granulation (using the polymer in an ethanolic solution (WGO) or aqueous dispersion (WGA) and solid dispersion (SD) techniques, on properties of paracetamol matrix tablets prepared using varying concentrations of acrylate methacrylate copolymer. Tablet properties were investigated using official and unofficial standards. Drug dissolution profile assessed at pH 1.2 was studied spectrophotometrically at λ(max) of 245 nm. With the use of various kinetic models, the release mechanism of the drug was analyzed. The parameters, maximum amount of drug release (m(∞)) at time t(∞) were obtained, m(∞) was ≥ 91.36 %, while t(∞) was ≥ 4.5 h. The release rate constant (k) for DG tablets was 15.61 h(sup>-1(/sup>, while, WGO, WGA and SD tablets were 12.90, 11.03 and 10.75 h(-1) respectively. The matrix tablets, which exhibited marked retardation in drug release displayed a Higuchi square root of time model (R(2) > 0.98). The mechanism through which the drug was released was governed by Fickian diffusion release (n values < 0.5). The performance of the drug was affected by the formulation technique in the order of SD > WGO > WGA > DG.

Infrared-induced variation of the magnetic properties of a magnetoplasmonic film with a 3D sub-micron periodic triangular roof-type antireflection structure

PubMed Central

Tian, Junlong; Zhang, Wang; Huang, Yiqiao; Liu, Qinglei; Wang, Yuhua; Zhang, Zhijian; Zhang, Di

2015-01-01

A carbon-matrix nickel composite magnetoplasmonic film with a 3D sub-micron periodic triangular roof-type antireflection structure (SPTAS) was fabricated via a simple and promising method that combines chemosynthesis with biomimetic techniques. The Troides helena (Linnaeus) forewing (T_FW) was chosen as the biomimetic template. The carbon-matrix Ni wing fabricated via electroless Ni deposition for 6 h (CNMF_6h) exhibits enhanced infrared absorption. Over a wavelength range (888–2500 nm), the enhancement of the infrared absorption of CNMF_6h is up to 1.85 times compared with the T_FW. Furthermore, infrared excitation induces a photothermal effect that results in variation in the magnetic properties of the carbon-matrix Ni wing. The magnetic properties were also confirmed using atomic force microscopy (AFM) and magnetic force microscopy (MFM). The good correlation between the AFM and MFM images demonstrates that the surface of the SPTAS of CNMF_6h exhibits strong magnetic properties. The infrared induced photothermal effect that results in magnetic variation is promising for use in the design of novel magnetoplasmonic films with potential applications in infrared information recording and heat-assisted magnetic recording. PMID:25620787

STS-51, RSRM-033, 360T033 KSC processing configuration and data report

NASA Technical Reports Server (NTRS)

Hillard, Robert C.

1993-01-01

KSC Processing Configuration and Data Report is being provided as a historical document and as an enhancement to future RSRM manufacturing and processing operations. The following sections provide information on segment receipt, aft booster build up, motor assembly, and closeout for STS-51, RSRM flight set 360T033. Section 2.0 contains a summary of RSRM-033 processing. Section 3.0 discusses any significant problems or special issues that require special attention. Sections 4.0 through 6.0 contain narrative descriptions of all key events, including any related processing problems. Appendix A provides engineering specifications and changes. A list and matrix of all problem reports (PR's) pertinent to this flight set is provided in Appendix B. The matrix was provided by the Thiokol LSS Quality Engineering office. Copies of the PR's generated during the processing of RSRM-033 will be provided upon request. Appendix C contains the motor set status matrix, which provides milestone dates for the RSRM-033 flow. Section 7.0 provides recommendations for the improvement of flight hardware processing. Section 8.0 contains data sheets that provide flight hardware parts and consumable information installed during the booster build-up and stacking operations by location, lot/serial number, expiration and cure dates/times, and installation dates.

From the quantum transfer matrix to the quench action: the Loschmidt echo in XXZ Heisenberg spin chains

NASA Astrophysics Data System (ADS)

Piroli, Lorenzo; Pozsgay, Balázs; Vernier, Eric

2017-02-01

We consider the computation of the Loschmidt echo after quantum quenches in the interacting XXZ Heisenberg spin chain both for real and imaginary times. We study two-site product initial states, focusing in particular on the Néel and tilted Néel states. We apply the quantum transfer matrix (QTM) approach to derive generalized TBA equations, which follow from the fusion hierarchy of the appropriate QTM’s. Our formulas are valid for arbitrary imaginary time and for real times at least up to a time t 0, after which the integral equations have to be modified. In some regimes, t 0 is seen to be either very large or infinite, allowing to explore in detail the post-quench dynamics of the system. As an important part of our work, we show that for the Néel state our imaginary time results can be recovered by means of the quench action approach, unveiling a direct connection with the quantum transfer matrix formalism. In particular, we show that in the zero-time limit, the study of our TBA equations allows for a simple alternative derivation of the recently obtained Bethe ansatz distribution functions for the Néel, tilted Néel and tilted ferromagnet states.

Constructing the GW self-energy of a point defect from the perfect crystal and the near neighborhood of the defect

NASA Astrophysics Data System (ADS)

Skachkov, Dmitry; van Schilfgaarde, Mark; Lambrecht, Walter

The full-potential linearized muffin-tin orbital method allows for a real space representation of the GW or quasi-particle self-consistent (QS)GW self-energy ΣR , L ; R' + T , L'. This can be used to construct the self-energy matrix for a point defect system in a large supercell from that of the perfect crystal in the primitive cell and the self-energy of the defect site and its near neighborhood, obtained self-consistently in a smaller supercell. At the interface between both regions we can average the two types of ΣR , L ; R' + T , L' matrix blocks. The result relies on the limited range of the self-energy matrix in real space. It means that we can calculate the quasiparticle energy levels of the defect system at essentially the cost of a DFT calculation and a few QSGW calculations for relatively small systems. The approach presently focuses on quasiparticle energy levels of band structures of the defect system rather than total energies. We will present test results for AsGa\\ in GaAs, ZnGe in ZnGeN2, NO, VO, VZn, and NO - VZn in ZnO. Supported by the US-DOE-BES under Grant No. DE-SC0008933.

Structure of the two-neutrino double-β decay matrix elements within perturbation theory

NASA Astrophysics Data System (ADS)

Štefánik, Dušan; Šimkovic, Fedor; Faessler, Amand

2015-06-01

The two-neutrino double-β Gamow-Teller and Fermi transitions are studied within an exactly solvable model, which allows a violation of both spin-isospin SU(4) and isospin SU(2) symmetries, and is expressed with generators of the SO(8) group. It is found that this model reproduces the main features of realistic calculation within the quasiparticle random-phase approximation with isospin symmetry restoration concerning the dependence of the two-neutrino double-β decay matrix elements on isovector and isoscalar particle-particle interactions. By using perturbation theory an explicit dependence of the two-neutrino double-β decay matrix elements on the like-nucleon pairing, particle-particle T =0 and T =1 , and particle-hole proton-neutron interactions is obtained. It is found that double-β decay matrix elements do not depend on the mean field part of Hamiltonian and that they are governed by a weak violation of both SU(2) and SU(4) symmetries by the particle-particle interaction of Hamiltonian. It is pointed out that there is a dominance of two-neutrino double-β decay transition through a single state of intermediate nucleus. The energy position of this state relative to energies of initial and final ground states is given by a combination of strengths of residual interactions. Further, energy-weighted Fermi and Gamow-Teller sum rules connecting Δ Z =2 nuclei are discussed. It is proposed that these sum rules can be used to study the residual interactions of the nuclear Hamiltonian, which are relevant for charge-changing nuclear transitions.

A Model for Estimating Nonlinear Deformation and Damage in Ceramic Matrix Composites (Preprint)

DTIC Science & Technology

2011-07-01

composite along a fiber direction are given by 2 EEE TL1   (A3) 1 TTLL 1 E2 EE     (A4) and the longitudinal (L) and transverse (T...properties of a single ply are given by  fMffL v1EvEE  (A5)   ffTfM MfT T v1EvE EE E   (A6)   L fMMfff L E v1EvE     (A7

Automation of an RCS (Radar Cross Section) Measurement System and Its Application to Investigate the Electromagnetic Scattering from Scale Model Aircraft Canopies

DTIC Science & Technology

1989-12-01

8217 -E ep IP 760 7v rag-2-t 7 -vet ca vo - a~ .:cz : 112 !] 10 Star-, requency i- -in.- -,,z. 200 :1h too t rouencv, i ax. 210 N T iarizat~on i2:)15. 220... 10 2-3 Pyramidal Radar Absorbing Material (RAM) ... . 11 2-4 Hardware configuration .... ............. 13 2-5 Point source model for phase variation...two plates ....... 51 4- 10 Gated RCS of 4 inch circular flat plate a) time doi. ain and b) frequency response . . . . 52 5-1 Measurement test matrix

Single Top Quark Production at the Tevatron

DOE Office of Scientific and Technical Information (OSTI.GOV)

Peters, Yvonne

2013-01-01

While the heaviest known elementary particle, the top quark, has been discovered in 1995 by the CDF and D0 collaborations in ttbar events, it took 14 more years until the observation of single top quark production. In this article, we discuss recent studies of single top quark production by the CDF and D0 collaborations at the Tevatron. In particular, we present the measurement of single top quark s- and t-channel production combined, the first observation of t-channel production, the simultaneous measurement of s- and t-channel production cross sections as well as the extraction of the CMK matrix element |Vtb}|.

Modular Matrix Multiplication on a Linear Array.

DTIC Science & Technology

1983-11-01

is fl(n2). 2 Case e Irl __ (see Figure 5.2) 2 2 ,1 Y, " X2v- ’ Y2 -. x= -- ~ Y4 "i; Yin Figure 5Ŗ At t--xi, either all Gk, such that IkEA , have n...nat and Image Proceuing, IEEE Transactions on Computers, Vol. C-31, No. 10 22 (October, 1982), pp. IO0oo09. [41 H.T. Kung, Let’s Design Algorithms for...VLSI Systems, Proc. Caltech Conf. on Very Large Scale Integration: Architecture, Design , Fabrication (January, 1979), pp. 65. 90. 151 H.T. Kung, and

Proton Spectra from He 3 + T and He 3 + He 3 Fusion at Low Center-of-Mass Energy, with Potential Implications for Solar Fusion Cross Sections

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zylstra, A. B.; Frenje, J. A.; Gatu Johnson, M.

Few-body nuclear physics often relies upon phenomenological models, with new efforts at the ab initio theory reported recently; both need high-quality benchmark data, particularly at low center-of-mass energies. We use high-energy-density plasmas to measure the proton spectra from 3He + T and 3He + 3He fusion. The data disagree with R -matrix predictions constrained by neutron spectra from T + T fusion. Here, we present a new analysis of the 3He + 3He proton spectrum; these benchmarked spectral shapes should be used for interpreting low-resolution data, such as solar fusion cross-section measurements.

Proton Spectra from 3He + T and 3He + 3He Fusion at Low Center-of-Mass Energy, with Potential Implications for Solar Fusion Cross Sections

NASA Astrophysics Data System (ADS)

Zylstra, A. B.; Frenje, J. A.; Gatu Johnson, M.; Hale, G. M.; Brune, C. R.; Bacher, A.; Casey, D. T.; Li, C. K.; McNabb, D.; Paris, M.; Petrasso, R. D.; Sangster, T. C.; Sayre, D. B.; Séguin, F. H.

2017-12-01

Few-body nuclear physics often relies upon phenomenological models, with new efforts at the ab initio theory reported recently; both need high-quality benchmark data, particularly at low center-of-mass energies. We use high-energy-density plasmas to measure the proton spectra from 3He +T and 3He + 3He fusion. The data disagree with R -matrix predictions constrained by neutron spectra from T +T fusion. We present a new analysis of the 3He + 3He 3 proton spectrum; these benchmarked spectral shapes should be used for interpreting low-resolution data, such as solar fusion cross-section measurements.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sinitsyn, N. A.

We consider nonadiabatic transitions in explicitly time-dependent systems with Hamiltonians of the form Hˆ(t)=Aˆ+Bˆt+Cˆ/t, where t is time and Aˆ,Bˆ,Cˆ are Hermitian N × N matrices. We show that in any model of this type, scattering matrix elements satisfy nontrivial exact constraints that follow from the absence of the Stokes phenomenon for solutions with specific conditions at t→–∞. This allows one to continue such solutions analytically to t→+∞, and connect their asymptotic behavior at t→–∞ and t→+∞. This property becomes particularly useful when a model shows additional discrete symmetries. Specifically, we derive a number of simple exact constraints and explicitmore » expressions for scattering probabilities in such systems.« less

Proton Spectra from He 3 + T and He 3 + He 3 Fusion at Low Center-of-Mass Energy, with Potential Implications for Solar Fusion Cross Sections

DOE PAGES

Zylstra, A. B.; Frenje, J. A.; Gatu Johnson, M.; ...

2017-11-29

Few-body nuclear physics often relies upon phenomenological models, with new efforts at the ab initio theory reported recently; both need high-quality benchmark data, particularly at low center-of-mass energies. We use high-energy-density plasmas to measure the proton spectra from 3He + T and 3He + 3He fusion. The data disagree with R -matrix predictions constrained by neutron spectra from T + T fusion. Here, we present a new analysis of the 3He + 3He proton spectrum; these benchmarked spectral shapes should be used for interpreting low-resolution data, such as solar fusion cross-section measurements.

The acellular matrix (ACM) for bladder tissue engineering: A quantitative magnetic resonance imaging study.

PubMed

Cheng, Hai-Ling Margaret; Loai, Yasir; Beaumont, Marine; Farhat, Walid A

2010-08-01

Bladder acellular matrices (ACMs) derived from natural tissue are gaining increasing attention for their role in tissue engineering and regeneration. Unlike conventional scaffolds based on biodegradable polymers or gels, ACMs possess native biomechanical and many acquired biologic properties. Efforts to optimize ACM-based scaffolds are ongoing and would be greatly assisted by a noninvasive means to characterize scaffold properties and monitor interaction with cells. MRI is well suited to this role, but research with MRI for scaffold characterization has been limited. This study presents initial results from quantitative MRI measurements for bladder ACM characterization and investigates the effects of incorporating hyaluronic acid, a natural biomaterial useful in tissue-engineering and regeneration. Measured MR relaxation times (T(1), T(2)) and diffusion coefficient were consistent with increased water uptake and glycosaminoglycan content observed on biochemistry in hyaluronic acid ACMs. Multicomponent MRI provided greater specificity, with diffusion data showing an acellular environment and T(2) components distinguishing the separate effects of increased glycosaminoglycans and hydration. These results suggest that quantitative MRI may provide useful information on matrix composition and structure, which is valuable in guiding further development using bladder ACMs for organ regeneration and in strategies involving the use of hyaluronic acid.

Green chemistry approaches to leather tanning process for making chrome-free leather by unnatural amino acids.

PubMed

Krishnamoorthy, G; Sadulla, S; Sehgal, P K; Mandal, Asit Baran

2012-05-15

In the present study, green and sustainable method or eco-friendly approaches to tanning process based on unnatural D-amino acids (D-AA)-aldehyde (Ald) as a substitute for chrome-free tanning has been attempted. The distribution of optically active D-AA in tanned leather, the hydrothermal stability, the mechanical properties and resistance to collagenolytic activity of tanned leather, the evaluation of eco-friendly characteristics were investigated. Scanning electron microscopic (SEM) and Atomic force microscopic (AFM) analyses indicate the surface morphology and roughness, respectively, of the tanned leather collagen matrix. Shrinkage and Differential scanning calorimetric (DSC) analyses shows that the shrinkage temperature (T(s)) and denaturation temperature (T(d)) of tanned leather are related to the content of D-AA+Ald present in the leather matrix. It has been found that the T(s) of D-AA tanned leather is more than that of Ald tanned leather and also more or less equal to chrome tanned leather. Environmental impact assessment (EIA) shows that the developed process results in significant reduction in total solids content (TSC) and improves better biodegradability of organic compound present in the effluent compared to chrome tanning. Copyright © 2012 Elsevier B.V. All rights reserved.

Flexible poly(ethylene carbonate)/garnet composite solid electrolyte reinforced by poly(vinylidene fluoride-hexafluoropropylene) for lithium metal batteries

NASA Astrophysics Data System (ADS)

He, Zijian; Chen, Long; Zhang, Bochen; Liu, Yongchang; Fan, Li-Zhen

2018-07-01

Solid-state electrolytes with high ionic conductivities, great flexibility, and easy processability are needed for high-performance solid-state rechargeable lithium batteries. In this work, we synthesize nanosized cubic Li6.25Al0.25La3Zr2O12 (LLZO) by solution combustion method and develop a flexible garnet-based composite solid electrolyte composed of LLZO, poly(ethylene carbonate) (PEC), poly(vinylidene fluoride-hexafluoropropylene) (P(VdF-HFP) and lithium bis(fluorosulfonyl)imide (LiFSI)). In the flexible composite solid electrolytes, LLZO nanoparticles, as ceramic matrix, have a positive effect on ionic conductivities and lithium ion transference number (tLi+). PEC, as a fast ion-conducting polymer, possesses high tLi+ inherently. P(VdF-HFP), as a binder, can strengthen mechanical properties. Consequently, the as-prepared composite solid electrolyte demonstrates high tLi+ (0.82) and superb thermal stability (remaining LLZO matrix after burning). All-solid-state LiFePO4|Li cells assembled with the flexible composite solid electrolyte deliver a high initial discharge specific capacity of 121.4 mAh g-1 and good cycling stability at 55 °C.

Upregulation of cathepsin S in psoriatic keratinocytes.

PubMed

Schönefuss, Alexander; Wendt, Wiebke; Schattling, Benjamin; Schulten, Roxane; Hoffmann, Klaus; Stuecker, Markus; Tigges, Christian; Lübbert, Hermann; Stichel, Christine

2010-08-01

Cathepsin S (CATS) is a cysteine protease, well known for its role in MHC class II-mediated antigen presentation and extracellular matrix degradation. Disturbance of the expression or metabolism of this protease is a concomitant feature of several diseases. Given this importance we studied the localization and regulation of CATS expression in normal and pathological human/mouse skin. In normal human skin CATS-immunostaining is mainly present in the dermis and is localized in macrophages, Langerhans, T- and endothelial cells, but absent in keratinocytes. In all analyzed pathological skin biopsies, i.e. atopic dermatitis, actinic keratosis and psoriasis, CATS staining is strongly increased in the dermis. But only in psoriasis, CATS-immunostaining is also detectable in keratinocytes. We show that cocultivation with T-cells as well as treatment with cytokines can trigger expression and secretion of CATS, which is involved in MHC II processing in keratinocytes. Our data provide first evidence that CATS expression (i) is selectively induced in psoriatic keratinocytes, (ii) is triggered by T-cells and (iii) might be involved in keratinocytic MHC class II expression, the processing of the MHC class II-associated invariant chain and remodeling of the extracellular matrix. This paper expands our knowledge on the important role of keratinocytes in dermatological disease.

Tumor-derived microvesicles mediate human breast cancer invasion through differentially glycosylated EMMPRIN.

PubMed

Menck, Kerstin; Scharf, Christian; Bleckmann, Annalen; Dyck, Lydia; Rost, Ulrike; Wenzel, Dirk; Dhople, Vishnu M; Siam, Laila; Pukrop, Tobias; Binder, Claudia; Klemm, Florian

2015-04-01

Tumor cells secrete not only a variety of soluble factors, but also extracellular vesicles that are known to support the establishment of a favorable tumor niche by influencing the surrounding stroma cells. Here we show that tumor-derived microvesicles (T-MV) also directly influence the tumor cells by enhancing their invasion in a both autologous and heterologous manner. Neither the respective vesicle-free supernatant nor MV from benign mammary cells mediate invasion. Uptake of T-MV is essential for the proinvasive effect. We further identify the highly glycosylated form of the extracellular matrix metalloproteinase inducer (EMMPRIN) as a marker for proinvasive MV. EMMPRIN is also present at high levels on MV from metastatic breast cancer patients in vivo. Anti-EMMPRIN strategies, such as MV deglycosylation, gene knockdown, and specific blocking peptides, inhibit MV-induced invasion. Interestingly, the effect of EMMPRIN-bearing MV is not mediated by matrix metalloproteinases but by activation of the p38/MAPK signaling pathway in the tumor cells. In conclusion, T-MV stimulate cancer cell invasion via a direct feedback mechanism dependent on highly glycosylated EMMPRIN. © The Author (2014). Published by Oxford University Press on behalf of Journal of Molecular Cell Biology, IBCB, SIBS, CAS.

Determination of the width of the top quark.

PubMed

Abazov, V M; Abbott, B; Abolins, M; Acharya, B S; Adams, M; Adams, T; Alexeev, G D; Alkhazov, G; Alton, A; Alverson, G; Alves, G A; Ancu, L S; Aoki, M; Arnoud, Y; Arov, M; Askew, A; Åsman, B; Atramentov, O; Avila, C; BackusMayes, J; Badaud, F; Bagby, L; Baldin, B; Bandurin, D V; Banerjee, S; Barberis, E; Baringer, P; Barreto, J; Bartlett, J F; Bassler, U; Bazterra, V; Beale, S; Bean, A; Begalli, M; Begel, M; Belanger-Champagne, C; Bellantoni, L; Beri, S B; Bernardi, G; Bernhard, R; Bertram, I; Besançon, M; Beuselinck, R; Bezzubov, V A; Bhat, P C; Bhatnagar, V; Blazey, G; Blessing, S; Bloom, K; Boehnlein, A; Boline, D; Bolton, T A; Boos, E E; Borissov, G; Bose, T; Brandt, A; Brandt, O; Brock, R; Brooijmans, G; Bross, A; Brown, D; Brown, J; Bu, X B; Buchholz, D; Buehler, M; Buescher, V; Bunichev, V; Burdin, S; Burnett, T H; Buszello, C P; Calpas, B; Camacho-Pérez, E; Carrasco-Lizarraga, M A; Casey, B C K; Castilla-Valdez, H; Chakrabarti, S; Chakraborty, D; Chan, K M; Chandra, A; Chen, G; Chevalier-Théry, S; Cho, D K; Cho, S W; Choi, S; Choudhary, B; Christoudias, T; Cihangir, S; Claes, D; Clutter, J; Cooke, M; Cooper, W E; Corcoran, M; Couderc, F; Cousinou, M-C; Croc, A; Cutts, D; Ćwiok, M; Das, A; Davies, G; De, K; de Jong, S J; De la Cruz-Burelo, E; Déliot, F; Demarteau, M; Demina, R; Denisov, D; Denisov, S P; Desai, S; DeVaughan, K; Diehl, H T; Diesburg, M; Dominguez, A; Dorland, T; Dubey, A; Dudko, L V; Duggan, D; Duperrin, A; Dutt, S; Dyshkant, A; Eads, M; Edmunds, D; Ellison, J; Elvira, V D; Enari, Y; Eno, S; Evans, H; Evdokimov, A; Evdokimov, V N; Facini, G; Ferbel, T; Fiedler, F; Filthaut, F; Fisher, W; Fisk, H E; Fortner, M; Fox, H; Fuess, S; Gadfort, T; Garcia-Bellido, A; Gavrilov, V; Gay, P; Geist, W; Geng, W; Gerbaudo, D; Gerber, C E; Gershtein, Y; Ginther, G; Golovanov, G; Goussiou, A; Grannis, P D; Greder, S; Greenlee, H; Greenwood, Z D; Gregores, E M; Grenier, G; Gris, Ph; Grivaz, J-F; Grohsjean, A; Grünendahl, S; Grünewald, M W; Guo, F; Guo, J; Gutierrez, G; Gutierrez, P; Haas, A; Hagopian, S; Haley, J; Han, L; Harder, K; Harel, A; Hauptman, J M; Hays, J; Head, T; Hebbeker, T; Hedin, D; Hegab, H; Heinson, A P; Heintz, U; Hensel, C; Heredia-De la Cruz, I; Herner, K; Hesketh, G; Hildreth, M D; Hirosky, R; Hoang, T; Hobbs, J D; Hoeneisen, B; Hohlfeld, M; Hossain, S; Hubacek, Z; Huske, N; Hynek, V; Iashvili, I; Illingworth, R; Ito, A S; Jabeen, S; Jaffré, M; Jain, S; Jamin, D; Jesik, R; Johns, K; Johnson, M; Johnston, D; Jonckheere, A; Jonsson, P; Joshi, J; Juste, A; Kaadze, K; Kajfasz, E; Karmanov, D; Kasper, P A; Katsanos, I; Kehoe, R; Kermiche, S; Khalatyan, N; Khanov, A; Kharchilava, A; Kharzheev, Y N; Khatidze, D; Kirby, M H; Kohli, J M; Kozelov, A V; Kraus, J; Kumar, A; Kupco, A; Kurča, T; Kuzmin, V A; Kvita, J; Lammers, S; Landsberg, G; Lebrun, P; Lee, H S; Lee, S W; Lee, W M; Lellouch, J; Li, L; Li, Q Z; Lietti, S M; Lim, J K; Lincoln, D; Linnemann, J; Lipaev, V V; Lipton, R; Liu, Y; Liu, Z; Lobodenko, A; Lokajicek, M; Love, P; Lubatti, H J; Luna-Garcia, R; Lyon, A L; Maciel, A K A; Mackin, D; Madar, R; Magaña-Villalba, R; Malik, S; Malyshev, V L; Maravin, Y; Martínez-Ortega, J; McCarthy, R; McGivern, C L; Meijer, M M; Melnitchouk, A; Menezes, D; Mercadante, P G; Merkin, M; Meyer, A; Meyer, J; Mondal, N K; Muanza, G S; Mulhearn, M; Nagy, E; Naimuddin, M; Narain, M; Nayyar, R; Neal, H A; Negret, J P; Neustroev, P; Novaes, S F; Nunnemann, T; Obrant, G; Orduna, J; Osman, N; Osta, J; Otero y Garzón, G J; Owen, M; Padilla, M; Pangilinan, M; Parashar, N; Parihar, V; Park, S K; Parsons, J; Partridge, R; Parua, N; Patwa, A; Penning, B; Perfilov, M; Peters, K; Peters, Y; Petrillo, G; Pétroff, P; Piegaia, R; Piper, J; Pleier, M-A; Podesta-Lerma, P L M; Podstavkov, V M; Pol, M-E; Polozov, P; Popov, A V; Prewitt, M; Price, D; Protopopescu, S; Qian, J; Quadt, A; Quinn, B; Rangel, M S; Ranjan, K; Ratoff, P N; Razumov, I; Renkel, P; Rich, P; Rijssenbeek, M; Ripp-Baudot, I; Rizatdinova, F; Rominsky, M; Royon, C; Rubinov, P; Ruchti, R; Safronov, G; Sajot, G; Sánchez-Hernández, A; Sanders, M P; Sanghi, B; Santos, A S; Savage, G; Sawyer, L; Scanlon, T; Schamberger, R D; Scheglov, Y; Schellman, H; Schliephake, T; Schlobohm, S; Schwanenberger, C; Schwienhorst, R; Sekaric, J; Severini, H; Shabalina, E; Shary, V; Shchukin, A A; Shivpuri, R K; Simak, V; Sirotenko, V; Skubic, P; Slattery, P; Smirnov, D; Smith, K J; Snow, G R; Snow, J; Snyder, S; Söldner-Rembold, S; Sonnenschein, L; Sopczak, A; Sosebee, M; Soustruznik, K; Spurlock, B; Stark, J; Stolin, V; Stoyanova, D A; Strauss, E; Strauss, M; Strom, D; Stutte, L; Svoisky, P; Takahashi, M; Tanasijczuk, A; Taylor, W; Titov, M; Tokmenin, V V; Tsybychev, D; Tuchming, B; Tully, C; Tuts, P M; Uvarov, L; Uvarov, S; Uzunyan, S; Van Kooten, R; van Leeuwen, W M; Varelas, N; Varnes, E W; Vasilyev, I A; Verdier, P; Vertogradov, L S; Verzocchi, M; Vesterinen, M; Vilanova, D; Vint, P; Vokac, P; Wahl, H D; Wang, M H L S; Warchol, J; Watts, G; Wayne, M; Weber, M; Welty-Rieger, L; Wetstein, M; White, A; Wicke, D; Williams, M R J; Wilson, G W; Wimpenny, S J; Wobisch, M; Wood, D R; Wyatt, T R; Xie, Y; Xu, C; Yacoob, S; Yamada, R; Yang, W-C; Yasuda, T; Yatsunenko, Y A; Ye, Z; Yin, H; Yip, K; Yoo, H D; Youn, S W; Yu, J; Zelitch, S; Zhao, T; Zhou, B; Zhu, J; Zielinski, M; Zieminska, D; Zivkovic, L

2011-01-14

We extract the total width of the top quark, Γ(t), from the partial decay width Γ(t → Wb) measured using the t-channel cross section for single top-quark production and from the branching fraction B(t → Wb) measured in tt events using up to 2.3  fb(-1) of integrated luminosity collected by the D0 Collaboration at the Tevatron pp Collider. The result is Γ(t) = 1.99(-0.55)(+0.69)  GeV, which translates to a top-quark lifetime of τ(t) = (3.3(-0.9)(+1.3)) × 10(-25)   s. Assuming a high mass fourth generation b' quark and unitarity of the four-generation quark-mixing matrix, we set the first upper limit on |V(tb')| < 0.63 at 95% C.L.

Linear absorptive dielectrics

NASA Astrophysics Data System (ADS)

Tip, A.

1998-06-01

Starting from Maxwell's equations for a linear, nonconducting, absorptive, and dispersive medium, characterized by the constitutive equations D(x,t)=ɛ1(x)E(x,t)+∫t-∞dsχ(x,t-s)E(x,s) and H(x,t)=B(x,t), a unitary time evolution and canonical formalism is obtained. Given the complex, coordinate, and frequency-dependent, electric permeability ɛ(x,ω), no further assumptions are made. The procedure leads to a proper definition of band gaps in the periodic case and a new continuity equation for energy flow. An S-matrix formalism for scattering from lossy objects is presented in full detail. A quantized version of the formalism is derived and applied to the generation of Čerenkov and transition radiation as well as atomic decay. The last case suggests a useful generalization of the density of states to the absorptive situation.

Effect of Vacuum-Sintering Temperature on Magnetic and Mechanical Properties of TiC-TiN-Ni-Mo-C Cermets

NASA Astrophysics Data System (ADS)

Zhang, Man; Yang, Qingqing; Xiong, Weihao; Zhou, Shiquan; Wang, Shengqing; Luo, Haifeng; Ruan, Linji

2018-05-01

The effect of vacuum-sintering temperature (T vs ), ranging from 1390 °C to 1470 °C, on magnetic and mechanical properties of TiC-10TiN-30Ni-6Mo-4C (mol pct) cermet was investigated in the present article. Room-temperature (RT) magnetization and maximum susceptibility decreased with increasing T vs up to 1450 °C, and then increased. This was mainly attributed to the fact that Ti content in the Ni-based binder phase increased with increasing T vs up to 1450 °C, suppressing ferromagnetism of the Ni matrix. RT ferromagnetism disappeared at T vs ≥ 1430 °C. Transverse rupture strength (TRS) reached a peak value at T vs = 1430 °C, and hardness did not significantly vary with T vs .

Calculations of Flowfield About Indented Nosetips,

DTIC Science & Technology

1982-08-23

agreement is good. UNCLASSIFIED SECURITY CLASSIFICATION OF THIS PAOE(ft,. Date E -t. , - NSWC TR 82-286 FOREWORD A finite difference computer program has been...Specific heat at constant pressure and volume respectively e Total energy per unit volume E ,F,H,R,S,T Functions of U AHT, HT Error in total enthalpy and...total enthalpy respectively ijGrid index in E and n directions respectively SI Identity matrix J,K Maximum grid point in E and n directions respectively

User-Friendly Tools for Random Matrices: An Introduction

DTIC Science & Technology

2012-12-03

T 2011 , Oliveira 2010, Mackey et al . 2012, ... Joel A. Tropp, User-Friendly Tools for Random Matrices, NIPS, 3 December 2012 47 To learn more... E...the matrix product Y = AΩ 3. Construct an orthonormal basis Q for the range of Y [Ref] Halko –Martinsson–T, SIAM Rev. 2011 . Joel A. Tropp, User-Friendly...concentration inequalities...” with L. Mackey et al .. Submitted 2012. § “User-Friendly Tools for Random Matrices: An Introduction.” 2012. See also

A Fundamental Study of P/M Processed Elevated Temperature Aluminum Alloys.

DTIC Science & Technology

1984-10-01

carried out on a SATEC model M3 creep testing machine. The creep extensometer was attached to a shoulder on the tensile specimen. 2 kil The complete matrix...Temperature Stress Es tOo5** t1.0 (OC) (MPa) (secŕ) (mins.) (mins.) 250 103.4 6.0 x 10-9 950.8 250 151.6 1.8 x 10-6 9.9 40.7 350 34.5 1.5 x 10 9 - - 350

Coupled Mode Formalism: Connecting Phasor, Matrix, and Geometrical Approaches

DTIC Science & Technology

2014-05-30

the Poincare sphere in classical optics, and was generalized to incoherent light as the Stokes and Mueller approach [4]. The Stokes description reduces...to the Poincare sphere description when one treats monochromatic light, and we restrict ourselves to this case. Background There are several...waves, cast as plane waves of the form g(z, t) = f(z − vt) = Aej(ω t −k z) , (1) namely a sinusoidal wave travelling in the positive z direction at phase

Symmetry of Isoscalar Matrix Elements and Systematics in the sd and beginning of fp shells

NASA Astrophysics Data System (ADS)

Orce, J. N.; Petkov, P.; Velázquez, V.; McKay, C. J.; Lesher, S. R.; Choudry, S.; Mynk, M.; Linnemann, A.; Jolie, J.; von Brentano, P.; Werner, V.; Yates, S. W.; McEllistrem, M. T.

2006-03-01

A careful determination of the lifetime and measurement of the branching ratio for decay of the first 2T=1+ state in 42Sc has allowed an accurate experimental test of charge independence in the A = 42 isobaric triplet. A lifetime of 69(17) fs was measured at the University of Kentucky, while relative intensities for the 975 keV and 1586 keV transitions depopulating the first 2T=1+ state have been determined at the University of Cologne as 100(1) and 8(1), respectively. Both measurements give an isoscalar matrix element, M0, of 6.4(9) (W.u.)1/2. This result confirms charge independence for the A=42 isobaric triplet. Shell model calculations have been carried out for understanding the global trend of M0 values for A = 4n + 2 isobaric triplets ranging from A = 18 to A = 42. The 21 (T=1)+ → 01 (T=1)+ transition energies, reduced transition probabilities and M0 values are reproduced to a high degree of accuracy. The trend of M0 strength along the sd shell is interpreted in terms of the shell structure. Certain discrepancies arise at the extremes of the sd shell, for the A = 18 and A = 38 isobaric triplets, which might be explained in terms of the low valence space at the extremes of the sd shell.

The Saccharomyces cerevisiae LOS1 gene involved in pre-tRNA splicing encodes a nuclear protein that behaves as a component of the nuclear matrix.

PubMed

Shen, W C; Selvakumar, D; Stanford, D R; Hopper, A K

1993-09-15

Mutations of the Saccharomyces cerevisiae LOS1 gene cause the accumulation of end matured intron-containing pre-tRNAs at elevated temperatures. In an effort to decipher the role of the LOS1 protein in pre-tRNA splicing, we have analyzed the LOS1 gene and its protein product. The LOS1 gene is located on the left arm of chromosome XI and the order of genes in this area of the chromosome is .... URA1 ... SAC1 TRP3 UBA1 STE6 LOS1 .... FAS1..... The LOS1 open reading frame encodes a putative protein of 1100 amino acids that shows no significant homology to other genes. The LOS1 open reading frame was tagged with the influenza virus hemagglutinin epitope recognized by the 12CA5 antibody. The 12CA5 antibody recognizes an epitope-tagged protein of the size predicted by the LOS1 open reading frame. Using this antibody for indirect immunofluorescence and cell fractionation studies we show that the LOS1 protein is located in nuclei. Los1p cannot be extracted from nuclei by treatment with nucleases, salts, or Triton X-100. This insolubility suggests that Los1p is a component of the nucleoskeleton. We propose that LOS1 mutations may affect pre-tRNA processing via alteration of the nuclear matrix.

A Transition in the Cumulative Reaction Rate of Two Species Diffusion with Bimolecular Reaction

NASA Astrophysics Data System (ADS)

Rajaram, Harihar; Arshadi, Masoud

2015-04-01

Diffusion and bimolecular reaction between two initially separated reacting species is a prototypical small-scale description of reaction induced by transverse mixing. It is also relevant to diffusion controlled transport regimes as encountered in low-permeability matrix blocks in fractured media. In previous work, the reaction-diffusion problem has been analyzed as a Stefan problem involving a distinct moving boundary (reaction front), which predicts that front motion scales as √t, and the cumulative reaction rate scales as 1/√t-. We present a general non-dimensionalization of the problem and a perturbation analysis to show that there is an early time regime where the cumulative reaction rate scales as √t- rather than 1/√t. The duration of this early time regime (where the cumulative rate is kinetically rather than diffusion controlled) depends on the rate parameter, in a manner that is consistently predicted by our non-dimensionalization. We also present results on the scaling of the reaction front width. We present numerical simulations in homogeneous and heterogeneous porous media to demonstrate the limited influence of heterogeneity on the behavior of the reaction-diffusion system. We illustrate applications to the practical problem of in-situ chemical oxidation of TCE and PCE by permanganate, which is employed to remediate contaminated sites where the DNAPLs are largely dissolved in the rock matrix.

Polymorphisms of the matrix metalloproteinase 9 gene and abdominal aortic aneurysm.

PubMed

Smallwood, L; Allcock, R; van Bockxmeer, F; Warrington, N; Palmer, L J; Iacopetta, B; Golledge, J; Norman, P E

2008-10-01

Increased matrix metalloproteinase (MMP) 9 activity has been implicated in the formation of abdominal aortic aneurysm (AAA). The aim was to explore the association between potentially functional variants of the MMP-9 gene and AAA. The -1562C > T and -1811A > T variants of the MMP-9 gene were genotyped in 678 men with an AAA (at least 30 mm in diameter) and 659 control subjects (aortic diameter 19-22 mm) recruited from a population-based trial of screening for AAA. Levels of MMP-9 were measured in a random subset of 300 cases and 84 controls. The association between genetic variants (including haplotypes) and AAA was assessed by multivariable logistic regression. There was no association between the MMP-9-1562C > T (odds ratio (OR) 0.70 (95 per cent confidence interval (c.i.) 0.27 to 1.82)) or -1811A > T (OR 0.71 (95 per cent c.i. 0.28 to 1.85)) genotypes, or the most common haplotype (OR 0.81 (95 per cent c.i. 0.62 to 1.05)) and AAA. The serum MMP-9 concentration was higher in cases than controls, and in minor allele carriers in cases and controls, although the differences were not statistically significant. In this study, the genetic tendency to higher levels of circulating MMP-9 was not associated with AAA.

MO-F-CAMPUS-I-04: Magnetic Resonance Imaging of An in Vitro 3D Tumor Model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Veiga, C; Long, T; Siow, B

Purpose: To investigate the use of an in vitro 3D tumor model (tumoroid) as a bio-phantom for repetitive and sequential magnetic resonance imaging (MRI) studies. Methods: The tissue engineered tumoroid comprised an artificial cancer mass (ACM) containing 30 million HT29 cancer cells seeded in a collagen type I matrix, whose density was increased by plastic compression (dry/wet weight=40%). The ACM was embedded in an uncompressed collagen gel that mimicked the tumor stroma, and the tumoroid was incubated for 24h before imaging. Images were acquired using the 1T ICON™ (Bruker Corporation, Billerica, MA) MRI scanner. T1 maps were calculated using anmore » IR-RARE sequence (TE=12ms, TR=10000ms, 7 inversion times), while for T2 maps a MSME technique (TR=6000ms, 16 echoes) was used. T1 and T2 fittings were performed using a pixel-wise approach to produce relaxometric parametric maps. Results: The images acquired and corresponding T1 and T2 maps indicate contrast between the ACM and the stroma. T1 was 2500 and 2800ms, while T2 was 520 and 760ms, for the ACM and stroma respectively. The ACM construct was not homogenous and internal features were visible, which can be explained by local gradients of cell and/or collagen density. The viability of the cells was confirmed via confocal microscopy for several days after the imaging session, demonstrating the suitability of the tumoroid for sequential imaging studies. Conclusions: We have engineered a tumor model compatible with repetitive and sequential MRI. We found T1 and T2 contrast between the ACM and stroma using a pre-clinical MRI scanner. The model, which enables controllable cell and matrix densities, has potential for a wide range of applications in radiotherapy, such as to study tumor progression and to validate imaging biomarkers. Further work is necessary to understand the mechanisms behind the contrast achieved, and to correlate findings with biology and histology data.« less

Design, Development and Optimization of S (-) Atenolol Floating Sustained Release Matrix Tablets Using Surface Response Methodology

PubMed Central

Gunjal, P. T.; Shinde, M. B.; Gharge, V. S.; Pimple, S. V.; Gurjar, M. K.; Shah, M. N.

2015-01-01

The objective of this present investigation was to develop and formulate floating sustained release matrix tablets of s (-) atenolol, by using different polymer combinations and filler, to optimize by using surface response methodology for different drug release variables and to evaluate the drug release pattern of the optimized product. Floating sustained release matrix tablets of various combinations were prepared with cellulose-based polymers: Hydroxypropyl methylcellulose, sodium bicarbonate as a gas generating agent, polyvinyl pyrrolidone as a binder and lactose monohydrate as filler. The 32 full factorial design was employed to investigate the effect of formulation variables on different properties of tablets applicable to floating lag time, buoyancy time, % drug release in 1 and 6 h (D1 h,D6 h) and time required to 90% drug release (t90%). Significance of result was analyzed using analysis of non variance and P < 0.05 was considered statistically significant. S (-) atenolol floating sustained release matrix tablets followed the Higuchi drug release kinetics that indicates the release of drug follows anomalous (non-Fickian) diffusion mechanism. The developed floating sustained release matrix tablet of improved efficacy can perform therapeutically better than a conventional tablet. PMID:26798171

Rice Protein Matrix Enhances Circulating Levels of Xanthohumol Following Acute Oral Intake of Spent Hops in Humans.

PubMed

O'Connor, Annalouise; Konda, Veera; Reed, Ralph L; Christensen, J Mark; Stevens, Jan F; Contractor, Nikhat

2018-03-01

Xanthohumol (XN), a prenylated flavonoid found in hops, exhibits anti-inflammatory and antioxidant properties. However, poor bioavailability may limit therapeutic applications. As food components are known to modulate polyphenol absorption, the objective is to determine whether a protein matrix could enhance the bioavailability of XN post oral consumption in humans. This is a randomized, double-blind, crossover study in healthy participants (n = 6) evaluating XN and its major metabolites (isoxanthohumol [IX], 6- and 8-prenylnaringenin [6-PN, 8-PN]) for 6 h following consumption of 12.4 mg of XN delivered via a spent hops-rice protein matrix preparation or a control spent hops preparation. Plasma XN and metabolites are measured by LC-MS/MS. C max , T max , and area-under-the-curve (AUC) values were determined. Circulating XN and metabolite response to each treatment was not bioequivalent. Plasma concentrations of XN and XN + metabolites (AUC) are greater with consumption of the spent hops-rice protein matrix preparation. Compared to a standard spent hops powder, a protein-rich spent hops matrix demonstrates enhanced plasma levels of XN and metabolites following acute oral intake. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Design, Development and Optimization of S (-) Atenolol Floating Sustained Release Matrix Tablets Using Surface Response Methodology.

PubMed

Gunjal, P T; Shinde, M B; Gharge, V S; Pimple, S V; Gurjar, M K; Shah, M N

2015-01-01

The objective of this present investigation was to develop and formulate floating sustained release matrix tablets of s (-) atenolol, by using different polymer combinations and filler, to optimize by using surface response methodology for different drug release variables and to evaluate the drug release pattern of the optimized product. Floating sustained release matrix tablets of various combinations were prepared with cellulose-based polymers: Hydroxypropyl methylcellulose, sodium bicarbonate as a gas generating agent, polyvinyl pyrrolidone as a binder and lactose monohydrate as filler. The 3(2) full factorial design was employed to investigate the effect of formulation variables on different properties of tablets applicable to floating lag time, buoyancy time, % drug release in 1 and 6 h (D1 h,D6 h) and time required to 90% drug release (t90%). Significance of result was analyzed using analysis of non variance and P < 0.05 was considered statistically significant. S (-) atenolol floating sustained release matrix tablets followed the Higuchi drug release kinetics that indicates the release of drug follows anomalous (non-Fickian) diffusion mechanism. The developed floating sustained release matrix tablet of improved efficacy can perform therapeutically better than a conventional tablet.

Enhanced osteoprogenitor elongated collagen fiber matrix formation by bioactive glass ionic silicon dependent on Sp7 (osterix) transcription.

PubMed

Varanasi, Venu G; Odatsu, Tetsurou; Bishop, Timothy; Chang, Joyce; Owyoung, Jeremy; Loomer, Peter M

2016-10-01

Bioactive glasses release ions, those enhance osteoblast collagen matrix synthesis and osteogenic marker expression during bone healing. Collagen matrix density and osteogenic marker expression depend on osteogenic transcription factors, (e.g., Osterix (OSX)). We hypothesize that enhanced expression and formation of collagen by Si(4+) depends on enhanced expression of OSX transcription. Experimental bioactive glass (6P53-b) and commercial Bioglass(TM) (45S5) were dissolved in basal medium to make glass conditioned medium (GCM). ICP-MS analysis was used to measure bioactive glass ion release rates. MC3T3-E1 cells were cultured for 20 days, and gene expression and extracellular matrix collagen formation was analyzed. In a separate study, siRNA was used to determine the effect of OSX knockdown on impacting the effect of Si(4+) on osteogenic markers and matrix collagen formation. Each bioactive glass exhibited similar ion release rates for all ions, except Mg(2+) released by 6P53-b. Gene expression results showed that GCM markedly enhanced many osteogenic markers, and 45S5 GCM showed higher levels of expression and collagen matrix fiber bundle density than 6P53-b GCM. Upon knockdown of OSX transcription, collagen type 5, alkaline phosphatase, and matrix density were not enhanced as compared to wild type cells. This study illustrates that the enhancement of elongated collagen fiber matrix formation by Si(±) depends on OSX transcription. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 2604-2615, 2016. © 2016 Wiley Periodicals, Inc.

Multichannel Compressive Sensing MRI Using Noiselet Encoding

PubMed Central

Pawar, Kamlesh; Egan, Gary; Zhang, Jingxin

2015-01-01

The incoherence between measurement and sparsifying transform matrices and the restricted isometry property (RIP) of measurement matrix are two of the key factors in determining the performance of compressive sensing (CS). In CS-MRI, the randomly under-sampled Fourier matrix is used as the measurement matrix and the wavelet transform is usually used as sparsifying transform matrix. However, the incoherence between the randomly under-sampled Fourier matrix and the wavelet matrix is not optimal, which can deteriorate the performance of CS-MRI. Using the mathematical result that noiselets are maximally incoherent with wavelets, this paper introduces the noiselet unitary bases as the measurement matrix to improve the incoherence and RIP in CS-MRI. Based on an empirical RIP analysis that compares the multichannel noiselet and multichannel Fourier measurement matrices in CS-MRI, we propose a multichannel compressive sensing (MCS) framework to take the advantage of multichannel data acquisition used in MRI scanners. Simulations are presented in the MCS framework to compare the performance of noiselet encoding reconstructions and Fourier encoding reconstructions at different acceleration factors. The comparisons indicate that multichannel noiselet measurement matrix has better RIP than that of its Fourier counterpart, and that noiselet encoded MCS-MRI outperforms Fourier encoded MCS-MRI in preserving image resolution and can achieve higher acceleration factors. To demonstrate the feasibility of the proposed noiselet encoding scheme, a pulse sequences with tailored spatially selective RF excitation pulses was designed and implemented on a 3T scanner to acquire the data in the noiselet domain from a phantom and a human brain. The results indicate that noislet encoding preserves image resolution better than Fouirer encoding. PMID:25965548

Advanced Ceramic Matrix Composites with Multifunctional and Hybrid Structures

NASA Technical Reports Server (NTRS)

Singh, Mrityunjay; Morscher, Gregory N.

2004-01-01

Ceramic matrix composites are leading candidate materials for a number of applications in aeronautics, space, energy, and nuclear industries. Potential composite applications differ in their requirements for thickness. For example, many space applications such as "nozzle ramps" or "heat exchangers" require very thin (< 1 mm) structures whereas turbine blades would require very thick parts (> or = 1 cm). Little is known about the effect of thickness on stress-strain behavior or the elevated temperature tensile properties controlled by oxidation diffusion. In this study, composites consisting of woven Hi-Nicalon (trademark) fibers a carbon interphase and CVI SiC matrix were fabricated with different numbers of plies and thicknesses. The effect of thickness on matrix crack formation, matrix crack growth and diffusion kinetics will be discussed. In another approach, hybrid fiber-lay up concepts have been utilized to "alloy" desirable properties of different fiber types for mechanical properties, thermal stress management, and oxidation resistance. Such an approach has potential for the C(sub I)-SiC and SiC(sub f)-SiC composite systems. CVI SiC matrix composites with different stacking sequences of woven C fiber (T300) layers and woven SiC fiber (Hi-Nicalon (trademark)) layers were fabricated. The results will be compared to standard C fiber reinforced CVI SiC matrix and Hi-Nicalon reinforced CVI SiC matrix composites. In addition, shear properties of these composites at different temperatures will also be presented. Other design and implementation issues will be discussed along with advantages and benefits of using these materials for various components in high temperature applications.

POTHMF: A program for computing potential curves and matrix elements of the coupled adiabatic radial equations for a hydrogen-like atom in a homogeneous magnetic field

NASA Astrophysics Data System (ADS)

Chuluunbaatar, O.; Gusev, A. A.; Gerdt, V. P.; Rostovtsev, V. A.; Vinitsky, S. I.; Abrashkevich, A. G.; Kaschiev, M. S.; Serov, V. V.

2008-02-01

A FORTRAN 77 program is presented which calculates with the relative machine precision potential curves and matrix elements of the coupled adiabatic radial equations for a hydrogen-like atom in a homogeneous magnetic field. The potential curves are eigenvalues corresponding to the angular oblate spheroidal functions that compose adiabatic basis which depends on the radial variable as a parameter. The matrix elements of radial coupling are integrals in angular variables of the following two types: product of angular functions and the first derivative of angular functions in parameter, and product of the first derivatives of angular functions in parameter, respectively. The program calculates also the angular part of the dipole transition matrix elements (in the length form) expressed as integrals in angular variables involving product of a dipole operator and angular functions. Moreover, the program calculates asymptotic regular and irregular matrix solutions of the coupled adiabatic radial equations at the end of interval in radial variable needed for solving a multi-channel scattering problem by the generalized R-matrix method. Potential curves and radial matrix elements computed by the POTHMF program can be used for solving the bound state and multi-channel scattering problems. As a test desk, the program is applied to the calculation of the energy values, a short-range reaction matrix and corresponding wave functions with the help of the KANTBP program. Benchmark calculations for the known photoionization cross-sections are presented. Program summaryProgram title:POTHMF Catalogue identifier:AEAA_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEAA_v1_0.html Program obtainable from:CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions:Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.:8123 No. of bytes in distributed program, including test data, etc.:131 396 Distribution format:tar.gz Programming language:FORTRAN 77 Computer:Intel Xeon EM64T, Alpha 21264A, AMD Athlon MP, Pentium IV Xeon, Opteron 248, Intel Pentium IV Operating system:OC Linux, Unix AIX 5.3, SunOS 5.8, Solaris, Windows XP RAM:Depends on the number of radial differential equations; the number and order of finite elements; the number of radial points. Test run requires 4 MB Classification:2.5 External routines:POTHMF uses some Lapack routines, copies of which are included in the distribution (see README file for details). Nature of problem:In the multi-channel adiabatic approach the Schrödinger equation for a hydrogen-like atom in a homogeneous magnetic field of strength γ ( γ=B/B, B≅2.35×10 T is a dimensionless parameter which determines the field strength B) is reduced by separating the radial coordinate, r, from the angular variables, (θ,φ), and using a basis of the angular oblate spheroidal functions [3] to a system of second-order ordinary differential equations which contain first-derivative coupling terms [4]. The purpose of this program is to calculate potential curves and matrix elements of radial coupling needed for calculating the low-lying bound and scattering states of hydrogen-like atoms in a homogeneous magnetic field of strength 0<γ⩽1000 within the adiabatic approach [5]. The program evaluates also asymptotic regular and irregular matrix radial solutions of the multi-channel scattering problem needed to extract from the R-matrix a required symmetric shortrange open-channel reaction matrix K [6] independent from matching point [7]. In addition, the program computes the dipole transition matrix elements in the length form between the basis functions that are needed for calculating the dipole transitions between the low-lying bound and scattering states and photoionization cross sections [8]. Solution method:The angular oblate spheroidal eigenvalue problem depending on the radial variable is solved using a series expansion in the Legendre polynomials [3]. The resulting tridiagonal symmetric algebraic eigenvalue problem for the evaluation of selected eigenvalues, i.e. the potential curves, is solved by the LDLT factorization using the DSTEVR program [2]. Derivatives of the eigenfunctions with respect to the radial variable which are contained in matrix elements of the coupled radial equations are obtained by solving the inhomogeneous algebraic equations. The corresponding algebraic problem is solved by using the LDLT factorization with the help of the DPTTRS program [2]. Asymptotics of the matrix elements at large values of radial variable are computed using a series expansion in the associated Laguerre polynomials [9]. The corresponding matching points between the numeric and asymptotic solutions are found automatically. These asymptotics are used for the evaluation of the asymptotic regular and irregular matrix radial solutions of the multi-channel scattering problem [7]. As a test desk, the program is applied to the calculation of the energy values of the ground and excited bound states and reaction matrix of multi-channel scattering problem for a hydrogen atom in a homogeneous magnetic field using the KANTBP program [10]. Restrictions:The computer memory requirements depend on: the number of radial differential equations; the number and order of finite elements; the total number of radial points. Restrictions due to dimension sizes can be changed by resetting a small number of PARAMETER statements before recompiling (see Introduction and listing for details). Running time:The running time depends critically upon: the number of radial differential equations; the number and order of finite elements; the total number of radial points on interval [r,r]. The test run which accompanies this paper took 7 s required for calculating of potential curves, radial matrix elements, and dipole transition matrix elements on a finite-element grid on interval [ r=0, r=100] used for solving discrete and continuous spectrum problems and obtaining asymptotic regular and irregular matrix radial solutions at r=100 for continuous spectrum problem on the Intel Pentium IV 2.4 GHz. The number of radial differential equations was equal to 6. The accompanying test run using the KANTBP program took 2 s for solving discrete and continuous spectrum problems using the above calculated potential curves, matrix elements and asymptotic regular and irregular matrix radial solutions. Note, that in the accompanied benchmark calculations of the photoionization cross-sections from the bound states of a hydrogen atom in a homogeneous magnetic field to continuum we have used interval [ r=0, r=1000] for continuous spectrum problem. The total number of radial differential equations was varied from 10 to 18. References:W.H. Press, S.A. Teukolsky, W.T. Vetterling, B.P. Flannery, Numerical Recipes: The Art of Scientific Computing, Cambridge University Press, Cambridge, 1986. http://www.netlib.org/lapack/. M. Abramovits, I.A. Stegun, Handbook of Mathematical Functions, Dover, New York, 1965. U. Fano, Colloq. Int. C.N.R.S. 273 (1977) 127; A.F. Starace, G.L. Webster, Phys. Rev. A 19 (1979) 1629-1640; C.V. Clark, K.T. Lu, A.F. Starace, in: H.G. Beyer, H. Kleinpoppen (Eds.), Progress in Atomic Spectroscopy, Part C, Plenum, New York, 1984, pp. 247-320; U. Fano, A.R.P. Rau, Atomic Collisions and Spectra, Academic Press, Florida, 1986. M.G. Dimova, M.S. Kaschiev, S.I. Vinitsky, J. Phys. B 38 (2005) 2337-2352; O. Chuluunbaatar, A.A. Gusev, V.L. Derbov, M.S. Kaschiev, V.V. Serov, T.V. Tupikova, S.I. Vinitsky, Proc. SPIE 6537 (2007) 653706-1-18. M.J. Seaton, Rep. Prog. Phys. 46 (1983) 167-257. M. Gailitis, J. Phys. B 9 (1976) 843-854; J. Macek, Phys. Rev. A 30 (1984) 1277-1278; S.I. Vinitsky, V.P. Gerdt, A.A. Gusev, M.S. Kaschiev, V.A. Rostovtsev, V.N. Samoylov, T.V. Tupikova, O. Chuluunbaatar, Programming and Computer Software 33 (2007) 105-116. H. Friedrich, Theoretical Atomic Physics, Springer, New York, 1991. R.J. Damburg, R.Kh. Propin, J. Phys. B 1 (1968) 681-691; J.D. Power, Phil. Trans. Roy. Soc. London A 274 (1973) 663-702. O. Chuluunbaatar, A.A. Gusev, A.G. Abrashkevich, A. Amaya-Tapia, M.S. Kaschiev, S.Y. Larsen, S.I. Vinitsky, Comput. Phys. Comm. 177 (2007) 649-675.

[50 years of connective tissue research: from the French Connective Tissue Club to the French Society of Extracellular Matrix Biology].

PubMed

Maquart, François-Xavier; Borel, Jacques-Paul

2012-01-01

The history of connective tissue research began in the late 18th century. However, it is only 50 years later that the concept of connective tissue was shaped. It took another fifty years before biochemical knowledge of extracellular matrix macromolecules began to emerge in the first half of the 20th century. In 1962, thanks to Ladislas and Barbara Robert, back from the US, the first society called "French Connective Tissue Club" was created in Paris. The first board was constituted of Albert Delaunay, Suzanne Bazin and Ladislas Robert. Very quickly, under the influence of these pioneers, national and international meetings were organized and, in 1967, a "Federation of the European Connective Tissue Clubs" was created at the initiative of Ladislas Robert (Paris) and John Scott (Manchester). It spread rapidly to the major European nations. In 1982 the transformation of "Clubs" in "Societies" occurred, a name more in line with the requirements of the time. In 2008, the "French Connective Tissue Society" became the "French Society of Extracellular Matrix Biology" ("Société Française de Biologie de la Matrice Extracellulaire", SFBMEc), to better highlight the importance of the extracellular matrix in the biology of living organisms. The SFBMEc's mission today is to promote and develop scientific exchanges between academic, industrial, and hospital laboratories involved in research on the extracellular matrix. SFBMEc organizes or subsidizes scientific meetings and awards scholarships to Ph.D. students or post-docs to participate in international conferences. It includes 200 to 250 members from different disciplines, developing strong interactions between scientists, clinicians and pathologists. It is present all around the French territory in many research laboratories. During these last 50 years, the extraordinary advances made possible by the development of new investigation techniques, in particular molecular biology, cell and tissue imaging, molecular modeling, etc., have permitted a considerable increase of the knowledge in the field of connective tissue. © Société de Biologie, 2012.

Effect of Shear Strain on the Structure and Properties of Chromium-Nickel Corrosion-Resistant Steels

NASA Astrophysics Data System (ADS)

Dobatkin, S. V.; Rybal'chenko, O. V.; Kliauga, A.; Tokar', A. A.

2015-07-01

The structure and properties of metastable austenitic steel 08Kh18N10T and stable austenitic steel ASTM F138 under shear deformation implemented by torsion under hydrostatic pressure (THP) at T = 300 and 450°C and by equichannel angular pressing (ECAP) at T = 400°C are studied. The THP yields an ultrafine-grain structure in a fully austenitic matrix with grain size 45 - 70 nm in steel ASTM F138 and 87 - 123 nm in steel 08Kh1810T. The ECAP at 400°C yields a grain-subgrain structure with structural elements 100 - 300 nm in size in steel 08Kh18N10T and 200 - 400 nm in size in steel ASTM F138.

DIRECT ELECTROCHEMICAL IMMUNOSENSOR FOR POLYCHLORINATED BIPHENYLS. (R825323)

EPA Science Inventory

A direct electrochemical immunosensor has been developed for the determination of polychlorinated biphenyls (PCBs) in water. The assay is based on the measurement of the current due to the specific binding between PCB and anti-PCB antibody-immobilized conducting polymer matrix. T...

Dynamical system modeling to simulate donor T cell response to whole exome sequencing-derived recipient peptides: Understanding randomness in alloreactivity incidence following stem cell transplantation.

PubMed

Koparde, Vishal; Abdul Razzaq, Badar; Suntum, Tara; Sabo, Roy; Scalora, Allison; Serrano, Myrna; Jameson-Lee, Max; Hall, Charles; Kobulnicky, David; Sheth, Nihar; Feltz, Juliana; Contaifer, Daniel; Wijesinghe, Dayanjan; Reed, Jason; Roberts, Catherine; Qayyum, Rehan; Buck, Gregory; Neale, Michael; Toor, Amir

2017-01-01

Quantitative relationship between the magnitude of variation in minor histocompatibility antigens (mHA) and graft versus host disease (GVHD) pathophysiology in stem cell transplant (SCT) donor-recipient pairs (DRP) is not established. In order to elucidate this relationship, whole exome sequencing (WES) was performed on 27 HLA matched related (MRD), & 50 unrelated donors (URD), to identify nonsynonymous single nucleotide polymorphisms (SNPs). An average 2,463 SNPs were identified in MRD, and 4,287 in URD DRP (p<0.01); resulting peptide antigens that may be presented on HLA class I molecules in each DRP were derived in silico (NetMHCpan ver2.0) and the tissue expression of proteins these were derived from determined (GTex). MRD DRP had an average 3,670 HLA-binding-alloreactive peptides, putative mHA (pmHA) with an IC50 of <500 nM, and URD, had 5,386 (p<0.01). To simulate an alloreactive donor cytotoxic T cell response, the array of pmHA in each patient was considered as an operator matrix modifying a hypothetical cytotoxic T cell clonal vector matrix; each responding T cell clone's proliferation was determined by the logistic equation of growth, accounting for HLA binding affinity and tissue expression of each alloreactive peptide. The resulting simulated organ-specific alloreactive T cell clonal growth revealed marked variability, with the T cell count differences spanning orders of magnitude between different DRP. Despite an estimated, uniform set of constants used in the model for all DRP, and a heterogeneously treated group of patients, higher total and organ-specific T cell counts were associated with cumulative incidence of moderate to severe GVHD in recipients. In conclusion, exome wide sequence differences and the variable alloreactive peptide binding to HLA in each DRP yields a large range of possible alloreactive donor T cell responses. Our findings also help understand the apparent randomness observed in the development of alloimmune responses.

Dynamical system modeling to simulate donor T cell response to whole exome sequencing-derived recipient peptides: Understanding randomness in alloreactivity incidence following stem cell transplantation

PubMed Central

Suntum, Tara; Sabo, Roy; Scalora, Allison; Serrano, Myrna; Jameson-Lee, Max; Hall, Charles; Kobulnicky, David; Sheth, Nihar; Feltz, Juliana; Contaifer, Daniel; Wijesinghe, Dayanjan; Reed, Jason; Roberts, Catherine; Qayyum, Rehan; Buck, Gregory; Neale, Michael

2017-01-01

Quantitative relationship between the magnitude of variation in minor histocompatibility antigens (mHA) and graft versus host disease (GVHD) pathophysiology in stem cell transplant (SCT) donor-recipient pairs (DRP) is not established. In order to elucidate this relationship, whole exome sequencing (WES) was performed on 27 HLA matched related (MRD), & 50 unrelated donors (URD), to identify nonsynonymous single nucleotide polymorphisms (SNPs). An average 2,463 SNPs were identified in MRD, and 4,287 in URD DRP (p<0.01); resulting peptide antigens that may be presented on HLA class I molecules in each DRP were derived in silico (NetMHCpan ver2.0) and the tissue expression of proteins these were derived from determined (GTex). MRD DRP had an average 3,670 HLA-binding-alloreactive peptides, putative mHA (pmHA) with an IC50 of <500 nM, and URD, had 5,386 (p<0.01). To simulate an alloreactive donor cytotoxic T cell response, the array of pmHA in each patient was considered as an operator matrix modifying a hypothetical cytotoxic T cell clonal vector matrix; each responding T cell clone’s proliferation was determined by the logistic equation of growth, accounting for HLA binding affinity and tissue expression of each alloreactive peptide. The resulting simulated organ-specific alloreactive T cell clonal growth revealed marked variability, with the T cell count differences spanning orders of magnitude between different DRP. Despite an estimated, uniform set of constants used in the model for all DRP, and a heterogeneously treated group of patients, higher total and organ-specific T cell counts were associated with cumulative incidence of moderate to severe GVHD in recipients. In conclusion, exome wide sequence differences and the variable alloreactive peptide binding to HLA in each DRP yields a large range of possible alloreactive donor T cell responses. Our findings also help understand the apparent randomness observed in the development of alloimmune responses. PMID:29194460

Early reduction of matrix metalloproteinase-8 serum levels is associated with leptin drop and predicts diabetes remission after bariatric surgery.

PubMed

Liberale, Luca; Bonaventura, Aldo; Carbone, Federico; Bertolotto, Maria; Contini, Paola; Scopinaro, Nicola; Camerini, Giovanni Bruno; Papadia, Francesco Saverio; Cordera, Renzo; Camici, Giovanni Guido; Dallegri, Franco; Adami, Gian Franco; Montecucco, Fabrizio

2017-10-15

We aimed at investigating whether the acute abrogation of leptin after bariatric surgery is able to reduce neutrophil activation and potentially affect type 2 diabetes mellitus (T2DM) remission. Metabolic and inflammatory parameters (i.e. leptin, IL-6 and neutrophil products) were compared at baseline (before bariatric surgery), one month, one and three years after surgery in morbid obese (MOB) T2DM patients (n=12) and non-MOB controls (n=32). In vitro, the effects of leptin on Il-6-induced human neutrophil degranulation and integrin upregulation were assessed. At baseline, MOB T2DM patients had a similar demographic, lipid and glycemic profiles than non-MOB T2DM controls, but higher levels of inflammatory mediators, such as CRP, fibrinogen, neutrophil-to-lymphocyte ratio (NLR), matrix metalloproteinase (MMP)-8 and leptin. One month after surgery, CRP, fibrinogen and MMP-8 were reduced only in MOB T2DM patients, while serum leptin was reduced in both groups. In the overall cohort, leptin and MMP-8 drops from baseline to one month post-surgery were positively correlated (Δleptin vs. ΔMMP8: r=0.391, p=0.025). Moreover, ΔMMP8 inversely correlated with fasting glucose levels at one-year follow-up and with glycated hemoglobin at both one- and three-year. At the cut-off point identified by ROC curve analysis (>0ng/mL), ΔMMP8 predicted complete T2DM remission at 3-year follow-up. In vitro, leptin increased IL-6-induced MMP-8 release and abrogated CD18 up-regulation. Bariatric surgery is associated to an acute abrogation of leptin that could affect MMP-8 levels, particularly in MOB T2DM patients. This beneficial event is associated with T2DM remission at 3-year follow-up. Copyright © 2017 Elsevier B.V. All rights reserved.

Compressed sensing for high-resolution nonlipid suppressed 1 H FID MRSI of the human brain at 9.4T.

PubMed

Nassirpour, Sahar; Chang, Paul; Avdievitch, Nikolai; Henning, Anke

2018-04-29

The aim of this study was to apply compressed sensing to accelerate the acquisition of high resolution metabolite maps of the human brain using a nonlipid suppressed ultra-short TR and TE 1 H FID MRSI sequence at 9.4T. X-t sparse compressed sensing reconstruction was optimized for nonlipid suppressed 1 H FID MRSI data. Coil-by-coil x-t sparse reconstruction was compared with SENSE x-t sparse and low rank reconstruction. The effect of matrix size and spatial resolution on the achievable acceleration factor was studied. Finally, in vivo metabolite maps with different acceleration factors of 2, 4, 5, and 10 were acquired and compared. Coil-by-coil x-t sparse compressed sensing reconstruction was not able to reliably recover the nonlipid suppressed data, rather a combination of parallel and sparse reconstruction was necessary (SENSE x-t sparse). For acceleration factors of up to 5, both the low-rank and the compressed sensing methods were able to reconstruct the data comparably well (root mean squared errors [RMSEs] ≤ 10.5% for Cre). However, the reconstruction time of the low rank algorithm was drastically longer than compressed sensing. Using the optimized compressed sensing reconstruction, acceleration factors of 4 or 5 could be reached for the MRSI data with a matrix size of 64 × 64. For lower spatial resolutions, an acceleration factor of up to R∼4 was successfully achieved. By tailoring the reconstruction scheme to the nonlipid suppressed data through parameter optimization and performance evaluation, we present high resolution (97 µL voxel size) accelerated in vivo metabolite maps of the human brain acquired at 9.4T within scan times of 3 to 3.75 min. © 2018 International Society for Magnetic Resonance in Medicine.

The stress, surface spin and dipolar interaction in the diluted NiFe{sub 2}O{sub 4} nanoparticles by the SiO{sub 2} matrix: Characterization and analyses

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sun, X.; Ma, Y.Q., E-mail: yqma@ahu.edu.cn; Xu, S.T.

2015-09-15

Well-dispersed uniform NiFe{sub 2}O{sub 4} nanoparticles (NPs) with an average particle size of 15.4 nm were synthesized by thermal decomposition of a metal–organic salt, and then were diluted in a SiO{sub 2} matrix via a sol–gel method with different concentration. The magnetization (M) dependence of NiFe{sub 2}O{sub 4}/SiO{sub 2} on the temperature (T) and on the applied magnetic field (H) was systematically characterized by the Quantum Design superconducting quantum interference device (SQUID) PPMS system. The results of M ~ H/T divide the magnetic properties between 10 K and 300 K into two regions: the low temperature blocked-particle regime below themore » blocking temperature T{sub B} and the interacting superparamagnetic (ISP) regime above T{sub B}. In the ISP regime, all samples deviate from the ideal Langevin superparamagnetic behavior due to the effective anisotropy induced by the stress, surface spins and interparticle dipolar interaction. The Raman spectra indicate that the stress in all samples exhibits the vibration behavior, which leads to the effective anisotropy and hence coercivity vibration. - Graphical abstract: Display Omitted - Highlights: • Increase of NiFe{sub 2}O{sub 4} NPs' concentration elevates T{sub B} and broadens ZFC peak. • NiFe{sub 2}O{sub 4}/SiO{sub 2} samples do not exhibit the ideal superparamagnetism above T{sub B}. • Stress leads to the effective anisotropy and hence H{sub c} vibration. • Stress vibration was characterized in detail by the Raman spectra.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Khadjavi, Amina; Magnetto, Chiara; Panariti, Alice

Background: : In chronic wounds, efficient epithelial tissue repair is hampered by hypoxia, and balances between the molecules involved in matrix turn-over such as matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) are seriously impaired. Intriguingly, new oxygenating nanocarriers such as 2H,3H-decafluoropentane-based oxygen-loaded nanodroplets (OLNs) might effectively target chronic wounds. Objective: : To investigate hypoxia and chitosan-shelled OLN effects on MMP/TIMP production by human keratinocytes. Methods: : HaCaT cells were treated for 24 h with 10% v/v OLNs both in normoxia or hypoxia. Cytotoxicity and cell viability were measured through biochemical assays; cellular uptake by confocal microscopy; and MMPmore » and TIMP production by enzyme-linked immunosorbent assay or gelatin zymography. Results: : Normoxic HaCaT cells constitutively released MMP-2, MMP-9, TIMP-1 and TIMP-2. Hypoxia strongly impaired MMP/TIMP balances by reducing MMP-2, MMP-9, and TIMP-2, without affecting TIMP-1 release. After cellular uptake by keratinocytes, nontoxic OLNs abrogated all hypoxia effects on MMP/TIMP secretion, restoring physiological balances. OLN abilities were specifically dependent on time-sustained oxygen diffusion from OLN core. Conclusion: : Chitosan-shelled OLNs effectively counteract hypoxia-dependent dysregulation of MMP/TIMP balances in human keratinocytes. Therefore, topical administration of exogenous oxygen, properly encapsulated in nanodroplet formulations, might be a promising adjuvant approach to promote healing processes in hypoxic wounds. - Highlights: • Hypoxia impairs MMP9/TIMP1 and MMP2/TIMP2 balances in HaCaT human keratinocytes. • Chitosan-shelled oxygen-loaded nanodroplets (OLNs) are internalised by HaCaT cells. • OLNs are not toxic to HaCaT cells. • OLNs effectively counteract hypoxia effects on MMP/TIMP balances in HaCaT cells. • OLNs appear as promising and cost-effective therapeutic tools for hypoxic wounds.« less

Off surface matrix based on-chip electrochemical biosensor platform for protein biomarker detection in undiluted serum.

PubMed

Arya, Sunil K; Kongsuphol, Patthara; Park, Mi Kyoung

2017-06-15

The manuscript describes a concept of using off surface matrix modified with capturing biomolecule for on-chip electrochemical biosensing. 3D matrix made by laser engraving of polymethyl methacrylate (PMMA) sheet as off surface matrix was integrated in very close vicinity of the electrode surface. Laser engraving and holes in PMMA along with spacing from surface provide fluidic channel and incubation chamber. Covalent binding of capturing biomolecule (anti-TNF-α antibody) on off-surface matrix was achieved via azide group activity of 4-fluoro-3-nitro-azidobenzene (FNAB), which act as cross-linker and further covalently binds to anti-TNF-α antibody via thermal reaction. Anti-TNF-α/FNAB/PMMA matrix was then integrated over comb structured gold electrode array based sensor chip. Separate surface modification followed by integration of sensor helped to prevent the sensor chip surface from fouling during functionalization. Nonspecific binding was prevented using starting block T20 (PBS). Results for estimating protein biomarker (TNF-α) in undiluted serum using Anti-TNF-α/FNAB/PMMA/Au reveal that system can detect TNF-α in 100pg/ml to 100ng/ml range with high sensitivity of 119nA/(ng/ml), with negligible interference from serum proteins and other cytokines. Thus, use of off surface matrix may provide the opportunity to electrochemically sense biomarkers sensitively to ng/ml range with negligible nonspecific binding and false signal in undiluted serum. Copyright © 2016 Elsevier B.V. All rights reserved.

Highly accelerated cardiac cine parallel MRI using low-rank matrix completion and partial separability model

NASA Astrophysics Data System (ADS)

Lyu, Jingyuan; Nakarmi, Ukash; Zhang, Chaoyi; Ying, Leslie

2016-05-01

This paper presents a new approach to highly accelerated dynamic parallel MRI using low rank matrix completion, partial separability (PS) model. In data acquisition, k-space data is moderately randomly undersampled at the center kspace navigator locations, but highly undersampled at the outer k-space for each temporal frame. In reconstruction, the navigator data is reconstructed from undersampled data using structured low-rank matrix completion. After all the unacquired navigator data is estimated, the partial separable model is used to obtain partial k-t data. Then the parallel imaging method is used to acquire the entire dynamic image series from highly undersampled data. The proposed method has shown to achieve high quality reconstructions with reduction factors up to 31, and temporal resolution of 29ms, when the conventional PS method fails.

A solver for General Unilateral Polynomial Matrix Equation with Second-Order Matrices Over Prime Finite Fields

NASA Astrophysics Data System (ADS)

Burtyka, Filipp

2018-03-01

The paper firstly considers the problem of finding solvents for arbitrary unilateral polynomial matrix equations with second-order matrices over prime finite fields from the practical point of view: we implement the solver for this problem. The solver’s algorithm has two step: the first is finding solvents, having Jordan Normal Form (JNF), the second is finding solvents among the rest matrices. The first step reduces to the finding roots of usual polynomials over finite fields, the second is essentially exhaustive search. The first step’s algorithms essentially use the polynomial matrices theory. We estimate the practical duration of computations using our software implementation (for example that one can’t construct unilateral matrix polynomial over finite field, having any predefined number of solvents) and answer some theoretically-valued questions.

Scalable Nonparametric Low-Rank Kernel Learning Using Block Coordinate Descent.

PubMed

Hu, En-Liang; Kwok, James T

2015-09-01

Nonparametric kernel learning (NPKL) is a flexible approach to learn the kernel matrix directly without assuming any parametric form. It can be naturally formulated as a semidefinite program (SDP), which, however, is not very scalable. To address this problem, we propose the combined use of low-rank approximation and block coordinate descent (BCD). Low-rank approximation avoids the expensive positive semidefinite constraint in the SDP by replacing the kernel matrix variable with V(T)V, where V is a low-rank matrix. The resultant nonlinear optimization problem is then solved by BCD, which optimizes each column of V sequentially. It can be shown that the proposed algorithm has nice convergence properties and low computational complexities. Experiments on a number of real-world data sets show that the proposed algorithm outperforms state-of-the-art NPKL solvers.

Role of Matrix Metalloproteinase-2, Matrix Metalloproteinase-9, and Vascular Endothelial Growth Factor in the Development of Chronic Subdural Hematoma

PubMed Central

Hua, Cong; Feng, Yan; Yuan, Hongyan; Song, Hongmei

2016-01-01

Abstract Chronic subdural hematoma (CSDH) is an inflammatory and angiogenic disease. Vascular endothelial growth factor (VEGF) has an important effect on the pathological progression of CSDH. The matrix metalloproteinases (MMPs) and VEGF also play a significant role in pathological angiogenesis. Our research was to investigate the level of MMPs and VEGF in serum and hematoma fluid. Magnetic Resonance Imaging (MRI) shows the characteristics of different stages of CSDH. We also analyzed the relationship between the level of VEGF in subdural hematoma fluid and the appearances of the patients' MRI. We performed a study comparing serum and hematoma fluid in 37 consecutive patients with primary CSDHs using enzyme-linked immunosorbent assay (ELISA). MMP-2 and MMP-9 activity was assayed by the gelatin zymography method. The patients were divided into five groups according to the appearance of the hematomas on MRI: group 1 (T1-weighted low, T2-weighted low, n=4), group 2 (T1-weighted high, T2-weighted low, n=11), group 3 (T1-weighted mixed, T2-weighted mixed, n=9), group 4 (T1-weighted high, T2-weighted high, n=5), and group 5 (T1-weighted low, T2-weighted high, n=8). Neurological status was assessed by Markwalder score on admission and at follow-up. The mean age, sex, and Markwalder score were not significantly different among groups. The mean concentration of VEGF, MMP-2, and MMP-9 were significantly higher in hematoma fluid than in serum (p<0.01). The level of pro-MMP-2 was higher in hematoma fluid (p<0.01). Measurement of MMP-9 showed both pro and active forms in both groups, but levels were higher in hematoma fluid (p<0.01 and p<0.01, respectively). Mean VEGF concentration was highest in group 1 (21,979.3±1387.3 pg/mL), followed by group 2 (20,060.1±1677.2 pg/mL), group 3 (13,746.5±3529.7 pg/mL), group 4 (7523.2±764.9 pg/mL), and lowest in group 5 (6801.9±618.7 pg/mL). There was a significant correlation between VEGF concentrations and MRI type (r=0.854). The present investigation is the first report showing that the concentrations of MMP-2 and MMP-9 are significantly elevated in hematoma fluid, suggesting that the MMPs/VEGF system may be involved in the angiogenesis of CSDH. We also demonstrate a significant correlation between the concentrations of VEGF and MRI appearance. This finding supports the hypothesis that high VEGF concentration in the hematoma fluid is of major pathophysiological importance in the generation and steady increase of the hematoma volume, as well as the determination of MRI appearance. PMID:25646653

Olivine-melt relationships and syneruptive redox variations in the 1959 eruption of Kīlauea Volcano as revealed by XANES

NASA Astrophysics Data System (ADS)

Helz, R. T.; Cottrell, E.; Brounce, M. N.; Kelley, K. A.

2017-03-01

The 1959 summit eruption of Kīlauea Volcano exhibited high lava fountains of gas-rich, primitive magma, containing olivine + chromian spinel in highly vesicular brown glass. Microprobe analysis of these samples shows that euhedral rims on olivine phenocrysts, in direct contact with glass, vary significantly in forsterite (Fo) content, at constant major-element melt composition, as do unzoned groundmass olivine crystals. Ferric/total iron (Fe+ 3/FeT)ratios for matrix and interstitial glasses, plus olivine-hosted glass inclusions in eight 1959 scoria samples have been determined by micro X-ray absorption near-edge structure spectroscopy (μ-XANES). These data show that much of the variation in Fo content reflects variation in oxidation state of iron in the melt, which varies with sulfur concentration in the glass and (locally) with proximity to scoria edges in contact with air. Data for 24 olivine-melt pairs in the better-equilibrated samples from later in the eruption show KD averaging 0.280 ± 0.03 for the exchange of Fe and Mg between olivine and melt, somewhat displaced from the value of 0.30 ± 0.03 given by Roeder and Emslie (1970). This may reflect the low SiO2 content of the 1959 magmas, which is lower than that in most Kīlauea tholeiites. More broadly, we show the potential of μ-XANES and electron microprobe to revisit and refine the value of KD in natural systems. The observed variations of Fe+ 3/FeT ratios in the glasses reflect two distinct processes. The main process, sulfur degassing, produces steady decrease of the Fe+ 3/FeT ratio. Melt inclusions in olivine are high in sulfur (1060-1500 ppm S), with Fe+ 3/FeT = 0.160-0.175. Matrix glasses are degassed (mostly S < 200 ppm) with generally lower Fe+ 3/FeT (0.114-0.135). Interstitial glasses within clumps of olivine crystals locally show intermediate levels of sulfur and Fe+ 3/FeT ratio. The correlation suggests that (1) the 1959 magma was significantly reduced by sulfur degassing during the eruption and (2) the melts originally had Fe+ 3/FeT ≥ 0.175, consistent with oxygen fugacity (fO2) at least 0.4 log units above the fayalite-magnetite-quartz (FMQ) buffer at 1 atm and magmatic temperature of 1200 °C. The second process is interaction between the melts and atmospheric oxygen, which results in higher Fe+ 3/FeT ratios. Detailed μ-XANES traverses show gradients in Fe+ 3/FeT of 0.145 to 0.628 over distances of 100-150 μm in thin, visibly reddened matrix glass bordering some scoriae, presumably caused by contact with air. This process was extremely rapid, giving insight into how fast the Fe+ 3/FeT ratio can change in response to changes in external conditions.

Influence of extremely low frequency, low energy electromagnetic fields and combined mechanical stimulation on chondrocytes in 3-D constructs for cartilage tissue engineering.

PubMed

Hilz, Florian M; Ahrens, Philipp; Grad, Sibylle; Stoddart, Martin J; Dahmani, Chiheb; Wilken, Frauke L; Sauerschnig, Martin; Niemeyer, Philipp; Zwingmann, Jörn; Burgkart, Rainer; von Eisenhart-Rothe, Rüdiger; Südkamp, Norbert P; Weyh, Thomas; Imhoff, Andreas B; Alini, Mauro; Salzmann, Gian M

2014-02-01

Articular cartilage, once damaged, has very low regenerative potential. Various experimental approaches have been conducted to enhance chondrogenesis and cartilage maturation. Among those, non-invasive electromagnetic fields have shown their beneficial influence for cartilage regeneration and are widely used for the treatment of non-unions, fractures, avascular necrosis and osteoarthritis. One very well accepted way to promote cartilage maturation is physical stimulation through bioreactors. The aim of this study was the investigation of combined mechanical and electromagnetic stress affecting cartilage cells in vitro. Primary articular chondrocytes from bovine fetlock joints were seeded into three-dimensional (3-D) polyurethane scaffolds and distributed into seven stimulated experimental groups. They either underwent mechanical or electromagnetic stimulation (sinusoidal electromagnetic field of 1 mT, 2 mT, or 3 mT; 60 Hz) or both within a joint-specific bioreactor and a coil system. The scaffold-cell constructs were analyzed for glycosaminoglycan (GAG) and DNA content, histology, and gene expression of collagen-1, collagen-2, aggrecan, cartilage oligomeric matrix protein (COMP), Sox9, proteoglycan-4 (PRG-4), and matrix metalloproteinases (MMP-3 and -13). There were statistically significant differences in GAG/DNA content between the stimulated versus the control group with highest levels in the combined stimulation group. Gene expression was significantly higher for combined stimulation groups versus static control for collagen 2/collagen 1 ratio and lower for MMP-13. Amongst other genes, a more chondrogenic phenotype was noticed in expression patterns for the stimulated groups. To conclude, there is an effect of electromagnetic and mechanical stimulation on chondrocytes seeded in a 3-D scaffold, resulting in improved extracellular matrix production. © 2013 Wiley Periodicals, Inc.

Numerical simulations of electromagnetic scattering by Solar system objects

NASA Astrophysics Data System (ADS)

Dlugach, Janna M.

2016-11-01

Having been profoundly stimulated by the seminal work of Viktor V. Sobolev, I have been involved in multi-decadal research in the fields of radiative transfer, electromagnetic scattering by morphologically complex particles and particulate media, and planetary remote sensing. Much of this research has been done in close collaboration with other "descendants" of Academician Sobolev. This tutorial paper gives a representative overview of the results of extensive numerical simulations (in the vast majority carried out in collaboration with Michael Mishchenko) used to analyze remote-sensing observations of Solar system objects and based on highly accurate methods of the radiative transfer theory and direct computer solvers of the Maxwell equations. Using the atmosphere of Jupiter as a proving ground and performing T-matrix and radiative-transfer calculations helps demonstrate the strong effect of aerosol-particle shapes on the accuracy of remote-sensing retrievals. I then discuss the application of the T-matrix method, a numerically exact solution of the vector radiative transfer equation, and the theory of coherent backscattering to an analysis of polarimetric radar observations of Saturn's rings. Numerical modeling performed by using the superposition T-matrix method in application to cometary dust in the form of aggregates serves to reproduce the results of polarimetric observations of the distant comet C/2010 S1. On the basis of direct computer solutions of the Maxwell equations, it is demonstrated that all backscattering effects predicted by the low-density theories of radiative transfer and coherent backscattering can also be identified for media with volume packing densities typically encountered in natural and artificial environments. This result implies that spectacular opposition effects observed for some high-albedo atmoshereless Solar system bodies can be attributed to coherent backscattering of sunlight by regolith layers composed of microscopic particles.

Correlation of pretreatment 18F-FDG PET tumor textural features with gene expression in pharyngeal cancer and implications for radiotherapy-based treatment outcomes.

PubMed

Chen, Shang-Wen; Shen, Wei-Chih; Lin, Ying-Chun; Chen, Rui-Yun; Hsieh, Te-Chun; Yen, Kuo-Yang; Kao, Chia-Hung

2017-04-01

This study investigated the correlation of the matrix heterogeneity of tumors on 18 F-fluorodeoxyglucose positron emission tomography-computed tomography (PET-CT) with gene-expression profiling in patients with pharyngeal cancer and determined the prognostic factors for radiotherapy-based treatment outcomes. We retrospectively reviewed the records of 57 patients with stage III-IV oropharyngeal or hypopharyngeal cancer who had completed definitive therapy. Four groups of the textural features as well as 31 indices were studied in addition to maximum standard uptake value, metastatic tumor volume, and total lesion glycolysis. Immunohistochemical data from pretreatment biopsy specimens (Glut1, CAIX, VEGF, HIF-1α, EGFR, Ki-67, Bcl-2, CLAUDIN-4, YAP-1, c-Met, and p16) were analyzed. The relationships between the indices and genomic expression were studied, and the robustness of various textural features relative to cause-specific survival and primary relapse-free survival was analyzed. The overexpression of VEGF was positively associated with the increased values of the matrix heterogeneity obtained using gray-level nonuniformity for zone (GLNUz) and run-length nonuniformity (RLNU). Advanced T stage (p = 0.01, hazard ratio [HR] = 3.38), a VEGF immunoreactive score of >2 (p = 0.03, HR = 2.79), and a higher GLNUz value (p = 0.04, HR = 2.51) were prognostic factors for low cause-specific survival, whereas advanced T stage, a HIF-1α staining percentage of ≥80%, and a higher GLNUz value were prognostic factors for low primary-relapse free survival. The overexpression of VEGF was associated with the increased matrix index of GLNUz and RLNU. For patients with pharyngeal cancer requiring radiotherapy, the treatment outcome can be stratified according to the textural features, T stage, and biomarkers.

Structures and vibrational spectra of pinacol.. 1. Infrared and matrix infrared spectra of monomeric pinacol. Ab initio calculations on conformers and vibrational frequencies

NASA Astrophysics Data System (ADS)

Dahlqvist, Martti; Hotokka, Matti; Räsänen, Markku

1998-04-01

The infrared spectra of monomeric pinacol molecules (2,3-dimethyl-2,3-butanediol; (CH 3) 2C(OH)C(OH)(CH 3) 2) have been recorded in the gas phase and dilute nonpolar solutions, and in an argon matrix. The vibrational data are consistent with the intramolecularly hydrogen-bonded G-type (gauche with respect to the central C-C bond) conformers and there is no evidence for the T-type (trans with respect to the central C-C bond) conformers, which have been observed in the condensed phases. This was confirmed by studying the infrared region 835-815 cm -1, which was found to be the most indicative to show spectral changes within the type of the conformers. In this region the band of the T-type conformers (assigned to the hybridized asymmetric vibration of the central CC and CO stretching modes) disappears when going from the condensed phases to phases, where pinacol molecules are monomeric. Ab initio HF/6-311G** (MP2/6-311G**) calculations support the experimental findings; the calculated relative energies for the tGg', gGg', g'Gg', tTt, and gTg' conformers are 0.0 (0.0), 3.4 (3.4), 5.1 (5.9), 7.9 (11.3), and 12.0 (14.0) kJ mol -1, respectively. Consequently, only the G-type conformers are sufficiently populated to give rise to observable spectral lines. Both experimental findings and theoretical calculations demonstrated that the bands in the argon matrix spectrum of pinacol are due to the most stable tGg' conformer. Although the ab initio calculations predict that also the gGg' and g'Gg' conformers are present in the gas phase and in dilute nonpolar solutions their existence could not be confirmed experimentally. Hence, we conclude that the conformation sensitive bands may coincide in the spectra. The HF/6-311G** ab initio calculations for vibrational frequencies of pinacol are consistent with this conclusion, suggesting only small differences between the wavenumbers of the G-type conformers. Pinacol does not show infrared-induced photorotamerization in the low-temperature argon matrix. This is due to the high energy barrier to internal rotation around the central C-C bond as demonstrated by ab initio calculations. Assignments of the vibrational bands were made with the aid of computer animations of the ab initio calculated harmonic vibrations, common group frequencies, and analogy conclusions from related compounds. The deuterium derivatives [(CD 3) 2C(OH)C(OH)(CD 3) 2 and (CH 3) 2C(OD)C(OD)(CH 3) 2] of pinacol were also utilized even though their spectra were recorded only in the condensed phases.

Developmental Programming: Gestational Exposure to Excess Testosterone Alters Expression of Ovarian Matrix Metalloproteases and Their Target Proteins.

PubMed

Puttabyatappa, Muraly; Irwin, Ashleigh; Martin, Jacob D; Mesquitta, Makeda; Veiga-Lopez, Almudena; Padmanabhan, Vasantha

2018-06-01

Prenatal testosterone (T)-treated sheep, similar to women with polycystic ovary syndrome (PCOS), manifests reproductive defects that include multifollicular ovarian phenotype. Women with PCOS manifest increased ovarian matrix metalloproteinases (MMPs) activity. We tested the hypothesis that gestational T excess in sheep would alter ovarian expression of MMPs, tissue inhibitors of MMP (TIMP) and their target proteins laminin B (LAMB), collagen, tumor necrosis factor alpha (TNF), and connexin 43 (GJA1) consistent with increased MMP activity and that these changes are developmentally regulated. The ovarian content of these proteins was quantified by immunohistochemistry in fetal day 90, 140, and adult (21 months of age) ovaries. Prenatal T excess lowered GJA1 protein content in stroma and granulosa cells of primary follicles from fetal day 90 ovaries and decreased stromal MMP9, TIMP1, and LAMB in fetal day 140 ovaries. In the adult, prenatal T-treatment (1) increased MMP9 in theca cells of large preantral follicles and stroma, TNF in granulosa cells of small and large preantral follicles and theca cells of large preantral and antral follicles, and GJA1 in stroma, theca cells of large preantral follicles, and granulosa cells of antral follicles and (2) reduced TIMP1 in stroma, theca cells of large preantral and antral follicles, LAMB in stroma and small prenatral follicles, and collagen content in stroma and around antral follicles. These findings suggest a net increase in MMP activity and its target proteins TNF and GJA1 in prenatal T-treated adult but not in fetal ovaries and their potential involvement in the development of multifollicular morphology.

High Temperature Advanced Structural Composites. Volume 2. Ceramic Matrix Composites, Fiber Processing and Properties, and Interfaces

DTIC Science & Technology

1993-04-02

1977) 97. 3 W. Wieswieler, E. Fitzer, G . Nagel, and H. Jager, Thin Solid Film, 148 (1987) 93. 4 T. A. Chernyshova , L. I. Kobelova, J. Mater. Scl., 20...AD-A267 023 I[E[gh ’Temperature kdvanced Structural (Composites Rensselaer Polytechnic Institute , \\ G Troy, N. Y. 12180-3590 - Final Report -- Book 2...thermodynamic data (heats of forma- ,(T p, comp.) °+p, comp.) (1) tion, absolute entropies, heat capacities) of reactants where g ’ is the chemical

Optimal Recovery Trajectories for Automatic Ground Collision Avoidance Systems (Auto GCAS)

DTIC Science & Technology

2015-03-01

the Multi-Trajectory path uses a sphere buffer (with a 350 ft radius) around each time point in the propagated path. Hence, the yellow Xs indicate the...the HUD as well as a matrix/line of Xs on the radar electro optical (REO) display. Enhanced ground clobber (EGC) mechanization was integrated on the F...reachable in the timespan t ∈ [t0, tf ], and dthreshold is a scalar user-defined terrain buffer. For the work de- veloped herein, dthreshold was set to 350

Imaging and Non-Imaging Polarimetric Methods for Remote Sensing

DTIC Science & Technology

2016-02-09

2013. 12. T. Wakayama, K. Komaki, I. Vaughn, J. S. Tyo, Y. Otani, T. Yoshizawa, Evaluation of Mueller matrix of achromatic axially symmetric...integral over all time in Eq. 4.6 can be computed by evaluating the Fourier transform of the integrand at f = 0: I[n] = ( h̃(f)P̃ (f) ) ∗ X̃(n, f) ∣∣∣ f...Variance (EWV) as an appropriate metric to evaluate Stokes polarime- ters,32 and Twietmeyer later adopted a similar metric for use with Mueller polarimeters

ACOSS Eleven (Active Control of Space Structures)

DTIC Science & Technology

1985-09-01

M . J . Vill.a lba T. C. Henderson I. G. Rosen I). B. Kasle J . 1). I’rner J . P. Govignon Contractor: The Charles...Michael J . Villalba (Section 8), Dr. 1. Gary Rosen (Section 9), and Dr. James D. Turner and Mr. Hion M . Chun (Section 10). Assistance from Mr. Saul Serben...matrix Riccati-like equations are discussed in detail. 47/48 -,.-. I. 4. , J ,. M S a C. t ’S a..S." a-- a.,. I w *.* -a .4 a, . .,- -..... s .’. J

Proceedings of the Army Symposium on Solid Mechanics, 1989 - Mechanics of Engineering Materials and Applications Held in Newport, Rhode Island on 16-18 May 1989

DTIC Science & Technology

1989-04-01

conventional fracture mechanics procedures, in conjuction with the superposition principle shown in Fig 2, it is then possible to compute the eigenstrains ...free strain eT ( eigenstrain , transformation strain) then, for the inclusion-matrix system the transformation strain eT induces constrained displacements...the equivalent body: The equivalent body contains elastically homogeneous inclusions with proper eigenstrains . Next, the average of the stress and

Damage Accumulation Process in Advanced Metal Matrix Composite Under Thermal Cycling

DTIC Science & Technology

1991-11-20

are calculated using the Eshelby’s equivalent inclusion method, (30) see Appendix A, where the eigenstrain eT is replaced by a °, Eq.(1). Oy - (1-Cm...and (2) e* is the fictitious eigenstrain introduced into the fiber domain (see Appendix A). The dots used in Eqs. (2) and (3) are inner product...Equivalent Inclusion Method Here we consider a composite which consists of aligned ellipsoidal inhomogeneities !a with a prescribed eigenstrain eT (called an