A novel enzyme-based acidizing system: Matrix acidizing and drilling fluid damage removal
Energy Technology Data Exchange (ETDEWEB)
Harris, R.E.; McKay, D.M. [Cleansorb Limited, Surrey (United Kingdom); Moses, V. [King`s College, London (United Kingdom)
1995-12-31
A novel acidizing process is used to increase the permeability of carbonate rock cores in the laboratory and to remove drilling fluid damage from cores and wafers. Field results show the benefits of the technology as applied both to injector and producer wells.
Tenreiro Machado, J. A.
2015-08-01
This paper addresses the matrix representation of dynamical systems in the perspective of fractional calculus. Fractional elements and fractional systems are interpreted under the light of the classical Cole-Cole, Davidson-Cole, and Havriliak-Negami heuristic models. Numerical simulations for an electrical circuit enlighten the results for matrix based models and high fractional orders. The conclusions clarify the distinction between fractional elements and fractional systems.
Zimmermann, Günter; Blöcher, Guido; Reinicke, Andreas; Brandt, Wulf
2011-04-01
Enhanced geothermal systems (EGS) are engineered reservoirs developed to extract economic amounts of heat from low permeability and/or porosity geothermal resources. To enhance the productivity of reservoirs, a site specific concept is necessary to actively make reservoir conditions profitable using specially adjusted stimulation treatments, such as multi fracture concepts and site specific well path design. The results of previously performed stimulation treatments in the geothermal research well GtGrSk4/05 at Groß Schönebeck, Germany are presented. The reservoir is located at a 4100-4300 m depth within the Lower Permian of the NE German Basin with a bottom-hole temperature of 150 °C. The reservoir rock is classified by two lithological units from bottom to top: volcanic rocks (andesitic rocks) and siliciclastics ranging from conglomerates to fine-grained sandstones (fluvial sediments). The stimulation treatments included multiple hydraulic stimulations and an acid treatment. In order to initiate a cross-flow from the sandstone layer, the hydraulic stimulations were performed in different depth sections (two in the sandstone section and one in the underlying volcanic section). In low permeability volcanic rocks, a cyclic hydraulic fracturing treatment was performed over 6 days in conjunction with adding quartz in low concentrations to maintain a sustainable fracture performance. Flow rates of up to 150 l/s were realized, and a total of 13,170 m 3 of water was injected. A hydraulic connection to the sandstone layer was successfully achieved in this way. However, monitoring of the water level in the offsetting well EGrSk3/90, which is 475 m apart at the final depth, showed a very rapid water level increase due to the stimulation treatment. This can be explained by a connected fault zone within the volcanic rocks. Two gel-proppant treatments were performed in the slightly higher permeability sandstones to obtain long-term access to the reservoir rocks. During each
Yan, Xiu-Fang; Wu, Hai-Long; Qing, Xiang-Dong; Sun, Yan-Mei; Yu, Ru-Qin
2014-01-01
In this work, a simple and practicable method that combines excitation-emission matrix (EEMs) fluorescence with a second-order calibration method based on parallel factor analysis-alternative least-squares (PARAFAC-ALS) algorithm was developed for the direct interference-free determination of indole-3-acetic acid (IAA) in two real systems, coconut water (CW) and coconut milk (CM). Although the excitation and emission profiles of IAA heavily overlapped with that of unknown interferents in the complex real systems, the actual contents and satisfactory recoveries were still obtained successfully. The contents of IAA in CW and CM were 10.8 ± 0.3 and 4.9 ± 0.2 μg mL(-1), respectively, which were consistent with those reported by LC-MS/MS assays in the reference material. The average spike recoveries of IAA in the validation set based on CW and CM were 102.1 ± 3.2 and 98.0 ± 1.9%, respectively. In addition, routine experiments were performed for establishing the validity of the assay to internationally accepted criteria.
Fragmentation of extracellular matrix by hypochlorous acid
DEFF Research Database (Denmark)
Woods, Alan A; Davies, Michael Jonathan
2003-01-01
The interaction of extracellular matrix with cells regulates their adhesion, migration and proliferation, and it is believed that damage to vascular matrix components is a factor in the development of atherosclerosis. Evidence has been provided for a role for the haem enzyme MPO (myeloperoxidase)...
Oil-free hyaluronic acid matrix for serial femtosecond crystallography
Sugahara, Michihiro; Song, Changyong; Suzuki, Mamoru; Masuda, Tetsuya; Inoue, Shigeyuki; Nakane, Takanori; Yumoto, Fumiaki; Nango, Eriko; Tanaka, Rie; Tono, Kensuke; Joti, Yasumasa; Kameshima, Takashi; Hatsui, Takaki; Yabashi, Makina; Nureki, Osamu; Numata, Keiji; Iwata, So
2016-04-01
The grease matrix was originally introduced as a microcrystal-carrier for serial femtosecond crystallography and has been expanded to applications for various types of proteins, including membrane proteins. However, the grease-based matrix has limited application for oil-sensitive proteins. Here we introduce a grease-free, water-based hyaluronic acid matrix. Applications for proteinase K and lysozyme proteins were able to produce electron density maps at 2.3-Å resolution.
The Matrix exponential, Dynamic Systems and Control
DEFF Research Database (Denmark)
Poulsen, Niels Kjølstad
2004-01-01
The matrix exponential can be found in various connections in analysis and control of dynamic systems. In this short note we are going to list a few examples. The matrix exponential usably pops up in connection to the sampling process, whatever it is in a deterministic or a stochastic setting...
The Matrix exponential, Dynamic Systems and Control
DEFF Research Database (Denmark)
Poulsen, Niels Kjølstad
2004-01-01
The matrix exponential can be found in various connections in analysis and control of dynamic systems. In this short note we are going to list a few examples. The matrix exponential usably pops up in connection to the sampling process, whatever it is in a deterministic or a stochastic setting...
Preparation of coated valproic acid and sodium valproate sustained-release matrix tablets
Directory of Open Access Journals (Sweden)
Phaechamud T
2010-01-01
Full Text Available The aim of this research was to investigate the technique for preparation of coated valproic acid and sodium valproate sustained-release matrix tablets. Different diluents were tested and selected as the effective absorbent for oily valproic acid. Effect of the amount of absorbent and hydroxypropylmethylcellulose on drug release from valproic acid-sodium valproate matrix tablets prepared with wet granulation technique was evaluated in pH change system. Colloidal silicon dioxide effectively adsorbed liquid valproic acid during wet granulation and granule preparation. The amounts of colloidal silicon dioxide and hydroxypropylmethylcellulose employed in tablet formulations affected drug release from the tablets. The drug release was prominently sustained for over 12 h using hydroxypropylmethylcellulose-based hydrophilic matrix system. The mechanism of drug release through the matrix polymer was a diffusion control. The drug release profile of the developed matrix tablet was similar to Depakine Chrono; , providing the values of similarity factor (f2 and difference factor (f1 of 85.56 and 2.37, respectively. Eudragit; L 30 D-55 was used as effective subcoating material for core matrix tablets before over coating with hydroxypropylmethylcellulose film with organic base solvent. Drug release profile of coated matrix tablet was almost similar to that of Depakine Chrono; .
Embedded systems for controlling LED matrix displays
Marghescu, Cristina; Drumea, Andrei
2016-12-01
LED matrix displays are a common presence in everyday life - they can be found in trains, buses, tramways, office information tables or outdoor media. The structure of the display unit is similar for all these devices, a matrix of light emitting diodes coupled between row and column lines, but there are many options for the display controller that switches these lines. Present paper analyzes different types of embedded systems that can control the LED matrix, based on single board computers, on microcontrollers with different peripheral devices or with programmable logic devices like field programmable gate arrays with implemented soft processor cores. Scalability, easiness of implementation and costs are analyzed for all proposed solutions.
Inverse Problems for Matrix Exponential in System Identification: System Aliasing
Yue, Zuogong; Thunberg, Johan; Goncalves, Jorge
2016-01-01
This note addresses identification of the $A$-matrix in continuous time linear dynamical systems on state-space form. If this matrix is partially known or known to have a sparse structure, such knowledge can be used to simplify the identification. We begin by introducing some general conditions for solvability of the inverse problems for matrix exponential. Next, we introduce "system aliasing" as an issue in the identification of slow sampled systems. Such aliasing give rise to non-unique mat...
GLYCOLIC-FORMIC ACID FLOWSHEET SLUDGE MATRIX STUDY
Energy Technology Data Exchange (ETDEWEB)
Lambert, D.; Koopman, D.
2011-06-30
Testing was completed to demonstrate the viability of the newly developed glycolic acid/formic acid flowsheet on processing in the Defense Waste Processing Facility's (DWPF) Chemical Process Cell (CPC). The Savannah River National Laboratory (SRNL) initiated a sludge matrix study to evaluate the impact of changing insoluble solid composition on the processing characteristics of slurries in DWPF. Four sludge simulants were prepared to cover two compositional ranges in the waste. The first was high iron/low aluminum versus low iron/high aluminum (referred to as HiFe or LoFe in this report). The second was high calcium-manganese/low nickel, chromium, and magnesium versus low calcium-manganese/high nickel, chromium, and magnesium (referred to as HiMn or LoMn in this report). These two options can be combined to form four distinct sludge compositions. The sludge matrix study called for testing each of these four simulants near the minimum acid required for nitrite destruction (100% acid stoichiometry) and at a second acid level that produced significant hydrogen by noble metal catalyzed decomposition of formic acid (150% acid stoichiometry). Four simulants were prepared based on the four possible combinations of the Al/Fe and Mn-Ca/Mg-Ni-Cr options. Preliminary simulant preparation work has already been documented. The four simulants were used for high and low acid testing. Eight planned experiments (GF26 to GF33) were completed to demonstrate the viability of the glycolic-formic flowsheet. Composition and physical property measurements were made on the SRAT product. Composition measurements were made on the condensate from the Mercury Water Wash Tank (MWWT), Formic Acid Vent Condenser (FAVC), ammonia scrubber and on SRAT samples pulled throughout the SRAT cycle. Updated values for formate loss and nitrite-tonitrate conversion were found that can be used in the acid calculations for future sludge matrix process simulations with the glycolic acid/formic acid
Controllability of semilinear matrix Lyapunov systems
Directory of Open Access Journals (Sweden)
Bhaskar Dubey
2013-02-01
Full Text Available In this article, we establish some sufficient conditions for the complete controllability of semilinear matrix Lyapunov systems involving Lipschitzian and non-Lipschitzian nonlinearities. In case of non-Lipschitzian nonlinearities, we assume that nonlinearities are of monotone type.
Electromagnetic Compatibility of Matrix Converter System
Directory of Open Access Journals (Sweden)
S. Fligl
2006-12-01
Full Text Available The presented paper deals with matrix converters pulse width modulation strategies design with emphasis on the electromagnetic compatibility. Matrix converters provide an all-silicon solution to the problem of converting AC power from one frequency to another, offering almost all the features required of an ideal static frequency changer. They possess many advantages compared to the conventional voltage or current source inverters. A matrix converter does not require energy storage components as a bulky capacitor or an inductance in the DC-link, and enables the bi-directional power flow between the power supply and load. The most of the contemporary modulation strategies are able to provide practically sinusoidal waveforms of the input and output currents with negligible low order harmonics, and to control the input displacement factor. The perspective of matrix converters regarding EMC in comparison with other types of converters is brightly evident because it is no need to use any equipment for power factor correction and current and voltage harmonics reduction. Such converter with proper control is properly compatible both with the supply mains and with the supplied load. A special digital control system was developed for the realized experimental test bed which makes it possible to achieve greater throughput of the digital control system and its variability.
Omanakuttan, Athira; Nambiar, Jyotsna; Harris, Rodney M; Bose, Chinchu; Pandurangan, Nanjan; Varghese, Rebu K; Kumar, Geetha B; Tainer, John A; Banerji, Asoke; Perry, J Jefferson P; Nair, Bipin G
2012-10-01
Cashew nut shell liquid (CNSL) has been used in traditional medicine for the treatment of a wide variety of pathophysiological conditions. To further define the mechanism of CNSL action, we investigated the effect of cashew nut shell extract (CNSE) on two matrix metalloproteinases, MMP-2/gelatinase A and MMP-9/gelatinase B, which are known to have critical roles in several disease states. We observed that the major constituent of CNSE, anacardic acid, markedly inhibited the gelatinase activity of 3T3-L1 cells. Our gelatin zymography studies on these two secreted gelatinases, present in the conditioned media from 3T3-L1 cells, established that anacardic acid directly inhibited the catalytic activities of both MMP-2 and MMP-9. Our docking studies suggested that anacardic acid binds into the MMP-2/9 active site, with the carboxylate group of anacardic acid chelating the catalytic zinc ion and forming a hydrogen bond to a key catalytic glutamate side chain and the C15 aliphatic group being accommodated within the relatively large S1' pocket of these gelatinases. In agreement with the docking results, our fluorescence-based studies on the recombinant MMP-2 catalytic core domain demonstrated that anacardic acid directly inhibits substrate peptide cleavage in a dose-dependent manner, with an IC₅₀ of 11.11 μM. In addition, our gelatinase zymography and fluorescence data confirmed that the cardol-cardanol mixture, salicylic acid, and aspirin, all of which lack key functional groups present in anacardic acid, are much weaker MMP-2/MMP-9 inhibitors. Our results provide the first evidence for inhibition of gelatinase catalytic activity by anacardic acid, providing a novel template for drug discovery and a molecular mechanism potentially involved in CNSL therapeutic action.
Open quantum systems and Random Matrix Theory
Mulhall, Declan
2014-01-01
A simple model for open quantum systems is analyzed with Random Matrix Theory. The system is coupled to the continuum in a minimal way. In this paper we see the effect of opening the system on the level statistics, in particular the $\\Delta_3(L)$ statistic, width distribution and level spacing are examined as a function of the strength of this coupling. A super-radiant transition is observed, and it is seen that as it is formed, the level spacing and $\\Delta_3(L)$ statistic exhibit the signatures of missed levels.
Open quantum systems and random matrix theory
Mulhall, Declan
2015-01-01
A simple model for open quantum systems is analyzed with random matrix theory. The system is coupled to the continuum in a minimal way. In this paper the effect on the level statistics of opening the system is seen. In particular the Δ3(L ) statistic, the width distribution and the level spacing are examined as a function of the strength of this coupling. The emergence of a super-radiant transition is observed. The level spacing and Δ3(L ) statistics exhibit the signatures of missed levels or intruder levels as the super-radiant state is formed.
Generating Nice Linear Systems for Matrix Gaussian Elimination
Homewood, L. James
2004-01-01
In this article an augmented matrix that represents a system of linear equations is called nice if a sequence of elementary row operations that reduces the matrix to row-echelon form, through matrix Gaussian elimination, does so by restricting all entries to integers in every step. Many instructors wish to use the example of matrix Gaussian…
Entanglement property in matrix product spin systems
Institute of Scientific and Technical Information of China (English)
ZHU Jing-Min
2012-01-01
We study the entanglement property in matrix product spin-ring systems systemically by von Neumann entropy.We find that:(i) the Hilbert space dimension of one spin determines the upper limit of the maximal value of the entanglement entropy of one spin,while for multiparticle entanglement entropy,the upper limit of the maximal value depends on the dimension of the representation matrices.Based on the theory,we can realize the maximum of the entanglement entropy of any spin block by choosing the appropriate control parameter values.(ii) When the entanglement entropy of one spin takes its maximal value,the entanglement entropy of an asymptotically large spin block,i.e. the renormalization group fixed point,is not likely to take its maximal value,and so only the entanglement entropy Sn of a spin block that varies with size n can fully characterize the spin-ring entanglement feature.Finally,we give the entanglement dynamics,i.e.the Hamiltonian of the matrix product system.
Matrix models with Penner interaction inspired by interacting ribonucleic acid
Indian Academy of Sciences (India)
Pradeep Bhadola; N Deo
2015-02-01
The Penner interaction known in studies of moduli space of punctured Riemann surfaces is introduced and studied in the context of random matrix model of homo RNA. An analytic derivation of the generating function is given and the corresponding partition function is derived numerically. An additional dependence of the structure combinatorics factor on (related to the size of the matrix and the interaction strength) is obtained. This factor has a strong effect on the structure combinatorics in the low regime. Databases are scanned for real ribonucleic acid (RNA) structures and pairing information for these RNA structures is computationally extracted. Then the genus is calculated for every structure and plotted as a function of length. The genus distribution function is compared with the prediction from the nonlinear (NL) model. The specific heat and distribution of structure with temperature calculated from the NL model shows that the NL inter-action is biased towards planar structures. The second derivative of specific heat changes phase from a double peaked function for small to a single peak for large . Detailed analysis reveals the presence of the double peak only for genus 0 structures, the higher genii behave normally with . Comparable behaviour is found in studies involving interactions of RNA with osmolytes and monovalent cations in unfolding experiments.
Rebane, Riin; Oldekop, Maarja-Liisa; Herodes, Koit
2014-04-01
Considering the importance of derivatization in LC/ESI/MS analysis, the objective of this work was to develop a method for evaluation of matrix effect that would discriminate between matrix effect due to the derivatization reaction yield and from the ESI. Four derivatization reagents (TAHS, DEEMM, DNS, FMOC-Cl) were studied with respect to matrix effects using two selenoamino acids and onion matrix as model system. A novel method for assessing matrix effects of LC/ESI/MS analyses involving derivatization is proposed, named herein post-derivatization spiking, that allows evaluating effect of matrix on ESI ionization without derivatization reaction yield contribution. The proposed post-derivatization spiking method allowed to demonstrate that the reason of reduced analytical signal can be signal suppression in ESI (as in case of DNS derivatives with matrix effects 38-99%), alteration of derivatization reaction yield (TAHS, matrix effects 92-113%, but reaction yields 20-50%) or both (FMOC-Cl, matrix effects 28-88% and reaction yields 50-70%). In case of DEEMM derivatives, matrix reduces reaction yield but enhances ESI/MS signal. A method for matrix effect evaluation was developed. It was also confirmed that matrix effects can be reduced by dilution.
Digraph matrix analysis applications to systems interactions
Energy Technology Data Exchange (ETDEWEB)
Alesso, H.P.; Altenbach, T.; Lappa, D.; Kimura, C.; Sacks, I.J.; Ashmore, B.C.; Fromme, D.; Smith, C.F.; Williams, W.
1984-01-01
Complex events such as Three Mile Island-2, Brown's Ferry-3 and Crystal River-3 have demonstrated that previously unidentified system interdependencies can be important to safety. A major aspect of these events was dependent faults (common cause/mode failures). The term systems interactions has been introduced by the Nuclear Regulatory Commission (NRC) to identify the concepts of spatial and functional coupling of systems which can lead to system interdependencies. Spatial coupling refers to dependencies resulting from a shared environmental condition; functional coupling refers to both dependencies resulting from components shared between safety and/or support systems, and to dependencies involving human actions. The NRC is currently developing guidelines to search for and evaluate adverse systems interactions at light water reactors. One approach utilizes graph theoretical methods and is called digraph matrix analysis (DMA). This methodology has been specifically tuned to the systems interaction problem. The objective of this paper is to present results from two DMA applications and to contrast them with the results from more traditional fault tree approaches.
Poly(lactic-co-glycolic acid) matrix incorporated with nisin as a novel antimicrobial biomaterial.
Correia, Rafaela Coelho; Jozala, Angela Faustino; Martins, Kelly Fernanda; Penna, Thereza Christina Vessoni; Duek, Eliana Aparecida de Rezende; Rangel-Yagui, Carlota de Oliveira; Lopes, André Moreni
2015-04-01
The use of poly(lactic-co-glycolic acid) (PLGA) matrix as a biomolecule carrier has been receiving great attention due to its potential therapeutic application. In this context, we investigated the PLGA matrix capacity to incorporate nisin, an antimicrobial peptide capable of inhibiting the growth of Gram-positive bacteria and bacterial spores germination. Nisin-incorporated PLGA matrices were evaluated based on the inhibitory effect against the nisin-bioindicator Lactobacillus sakei. Additionally, the PLGA-nisin matrix stability over an 8-months period was investigated, as well as the nisin release profile. For the incorporation conditions, we observed that a 5 h incorporation time, at 30 °C, with 250 μg/mL nisin solution in PBS buffer pH 4.5, resulted in the highest inhibitory activity of 2.70 logAU/mL. The PLGA-nisin matrix was found to be relatively stable and showed sustained drug delivery, with continuous release of nisin for 2 weeks. Therefore, PLGA-nisin matrix is could be used as a novel antimicrobial delivery system and an alternative to antibiotics incorporated into PLGA matrices.
Solution of the Lyapunov matrix equation for a system with a time-dependent stiffness matrix
DEFF Research Database (Denmark)
Pommer, Christian; Kliem, Wolfhard
2004-01-01
The stability of the linearized model of a rotor system with non-symmetric strain and axial loads is investigated. Since we are using a fixed reference system, the differential equations have the advantage to be free of Coriolis and centrifugal forces. A disadvantage is nevertheless the occurrenc...... of time-dependent periodic terms in the stiffness matrix. However, by solving the Lyapunov matrix equation we can formulate several stability conditions for the rotor system. Hereby the positive definiteness of a certain averaged stiffness matrix plays a crucial role....
High-Speed Computer-Controlled Switch-Matrix System
Spisz, E.; Cory, B.; Ho, P.; Hoffman, M.
1985-01-01
High-speed computer-controlled switch-matrix system developed for communication satellites. Satellite system controlled by onboard computer and all message-routing functions between uplink and downlink beams handled by newly developed switch-matrix system. Message requires only 2-microsecond interconnect period, repeated every millisecond.
Random matrix theory, interacting particle systems and integrable systems
Forrester, Peter
2014-01-01
Random matrix theory is at the intersection of linear algebra, probability theory and integrable systems, and has a wide range of applications in physics, engineering, multivariate statistics and beyond. This volume is based on a Fall 2010 MSRI program which generated the solution of long-standing questions on universalities of Wigner matrices and beta-ensembles and opened new research directions especially in relation to the KPZ universality class of interacting particle systems and low-rank perturbations. The book contains review articles and research contributions on all these topics, in addition to other core aspects of random matrix theory such as integrability and free probability theory. It will give both established and new researchers insights into the most recent advances in the field and the connections among many subfields.
Polymer Matrix Composites for Propulsion Systems
Nettles, Alan T.
2003-01-01
The Access-to-Space study identified the requirement for lightweight structures to achieve orbit with a single-stage vehicle. Thus a task was undertaken to examine the use of polymer matrix composites for propulsion components. It was determined that the effort of this task would be to extend previous efforts with polymer matrix composite feedlines and demonstrate the feasibility of manufacturing large diameter feedlines with a complex shape and integral flanges, (i.e. all one piece with a 90 deg bend), and assess their performance under a cryogenic atmosphere.
Yan, Wang-Ji; Katafygiotis, Lambros S.
2016-10-01
The problem of stochastic system identification utilizing response measurements only is considered in this paper. A negative log-likelihood function utilized to determine the posterior most probable parameters and their associated uncertainties is formulated by incorporating transmissibility matrix concept, random matrix theory and Bayes’ theorem. A numerically iterative coupled method involving the optimization of the parameters in groups is proposed so as to reduce the dimension of the numerical optimization problem involved. The initial guess for the parameters to be optimized is also properly estimated through asymptotic analysis. One novel feature of the proposed method is to avoid repeated time-consuming evaluation of the determinant and inverse of the covariance matrix during optimization due to exploring the statistical properties of the trace of Wishart matrix. The proposed method requires no information about the model of the external input. The theory described in this work is illustrated with synthetic data and field data measured from a laboratory model installed with wireless sensors.
Directory of Open Access Journals (Sweden)
N. A. Vunder
2016-03-01
Full Text Available Subject of Research.The paper deals with the problem of required placement of state matrix modes in the system being designed.Methods.The problem has been solved with the use of vector matrix formalism of state space method with the dominant attention at the algebraic properties of the object control matrix. Main Results. Algebraic conditions have been obtained imposed on the matrix components of control plant and system models, which has helped to create the algorithms for solving the tasks without necessarily resorting to matrix Sylvester equation and Ackermann's formula. Practical Relevance. User’s base of algorithms for synthesis procedures of control systems with specified quality indices has been extended.
Teichoic acid is the major polysaccharide present in the Listeria monocytogenes biofilm matrix.
Brauge, Thomas; Sadovskaya, Irina; Faille, Christine; Benezech, Thierry; Maes, Emmanuel; Guerardel, Yann; Midelet-Bourdin, Graziella
2016-01-01
The aim of this study was to characterize the Listeria monocytogenes biofilm and particularly the nature of the carbohydrates in the biofilm extracellular matrix and culture supernatant versus to cell wall carbohydrates. Listeria monocytogenes serotype 1/2a and 4b strains were able to form complex biofilms embedded in an extracellular matrix. The soluble carbohydrates from biofilm extracellular matrix and culture supernatant were identified as teichoic acids, structurally identical to cell wall teichoic acids. In addition, the DSS 1130 BFA2 strain had a serotype 1/2a teichoic acid lacking N-acetyl glucosamine glycosylation due to a mutation in the lmo2550 gene. Consequently, we hypothesized that the extracellular teichoic acids in L. monocytogenes biofilms have the same origin as cell wall teichoic acid. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
Phosphoric acid as a matrix additive for MALDI MS analysis of phosphopeptides and phosphoproteins
DEFF Research Database (Denmark)
Kjellström, Sven; Jensen, Ole Nørregaard
2004-01-01
Phosphopeptides are often detected with low efficiency by MALDI MS analysis of peptide mixtures. In an effort to improve the phosphopeptide ion response in MALDI MS, we investigated the effects of adding low concentrations of organic and inorganic acids during peptide sample preparation in 2......,5-dihydroxybenzoic acid (2,5-DHB) matrix. Phosphoric acid in combination with 2,5-DHB matrix significantly enhanced phosphopeptide ion signals in MALDI mass spectra of crude peptide mixtures derived from the phosphorylated proteins alpha-casein and beta-casein. The beneficial effects of adding up to 1% phosphoric...... acid to 2,5-DHB were also observed in LC-MALDI-MS analysis of tryptic phosphopeptides of B. subtilis PrkC phosphoprotein. Finally, the mass resolution of MALDI mass spectra of intact proteins was significantly improved by using phosphoric acid in 2,5-DHB matrix....
Screw-matrix method in dynamics of multibody systems
Yanzhu, Liu
1988-05-01
In the present paper the concept of screw in classical mechanics is expressed in matrix form, in order to formulate the dynamical equations of the multibody systems. The mentioned method can retain the advantages of the screw theory and avoid the shortcomings of the dual number notation. Combining the screw-matrix method with the tool of graph theory in Roberson/Wittenberg formalism. We can expand the application of the screw theory to the general case of multibody systems. For a tree system, the dynamical equations for each j-th subsystem, composed of all the outboard bodies connected by j-th joint can be formulated without the constraint reaction forces in the joints. For a nontree system, the dynamical equations of subsystems and the kinematical consistency conditions of the joints can be derived using the loop matrix. The whole process of calculation is unified in matrix form. A three-segment manipulator is discussed as an example.
Percolation phenomena in diffusion-controlled polymer matrix systems
Institute of Scientific and Technical Information of China (English)
徐铜文; 何炳林
1997-01-01
The controlled release of two kinds of drugs,5-fluorouracil (5-FU) and hydrocortisonum (Hydro.) loaded in poly(ethylene-vinylalcohol) (EVAL) was dealt with,of which 5-FU/EVAL and Hydro /EVAL matrix systems are composed.The results were analyzed using the pseudo-steady-diffusion models coupled with the fundamental concepts of percolation theory.The percolation thresholds for the two systems were calculated,which could indicate the contributions of pore diffusion and matrix diffusion.
Citric Acid Capped Iron Oxide Nanoparticles as an Effective MALDI Matrix for Polymers
Liang, Qiaoli; Sherwood, Jennifer; Macher, Thomas; Wilson, Joseph M.; Bao, Yuping; Cassady, Carolyn J.
2016-12-01
A new matrix-assisted laser desorption ionization (MALDI) mass spectrometry matrix is proposed for molecular mass determination of polymers. This matrix contains an iron oxide nanoparticle (NP) core with citric acid (CA) molecules covalently bound to the surface. With the assistance of additives, the particulate nature of NPs allows the matrix to mix uniformly with polar or nonpolar polymer layers and promotes ionization, which may simplify matrix selection and sample preparation procedures. Several distinctively different polymer classes (polyethyleneglycol (PEG), polywax/polyethylene, perfluoropolyether, and polydimethylsiloxane) are effectively detected by the water or methanol dispersed NPCA matrix with NaCl, NaOH, LiOH, or AgNO3 as additives. Furtheremore, successful quantitative measurements of PEG1000 using polypropylene glycol 1000 as an internal standard are demonstrated.
On Controllability and Observability of Fuzzy Dynamical Matrix Lyapunov Systems
Directory of Open Access Journals (Sweden)
M. S. N. Murty
2008-04-01
Full Text Available We provide a way to combine matrix Lyapunov systems with fuzzy rules to form a new fuzzy system called fuzzy dynamical matrix Lyapunov system, which can be regarded as a new approach to intelligent control. First, we study the controllability property of the fuzzy dynamical matrix Lyapunov system and provide a sufficient condition for its controllability with the use of fuzzy rule base. The significance of our result is that given a deterministic system and a fuzzy state with rule base, we can determine the rule base for the control. Further, we discuss the concept of observability and give a sufficient condition for the system to be observable. The advantage of our result is that we can determine the rule base for the initial value without solving the system.
Amino Acids Analysis by MALDI Mass Spectrometry Using Carbon Nanotube as Matrix
Institute of Scientific and Technical Information of China (English)
张菁; 王昊阳; 郭寅龙
2005-01-01
Twenty common amino acids have been analyzed successfully by matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) using carbon nanotubes as matrix. From the spectra, little or no background interference or fragmentation of the analytes has been observed. This method was also applied to the analysis of amino acid mixture successfully. Carbon nanotubes have some features such as large surface area to disperse the analyte molecules sufficiently and prevent the sample aggregation and strong ultraviolet absorption to transfer energy easily to the analyte molecules. The present method has potential application for the rapid and sensitive analysis of amino acids and their mixture.
Directory of Open Access Journals (Sweden)
Nadie Fatimatuzzahro
2014-11-01
Full Text Available Etching agents such as ethylene diamine tetraacetic acid (EDTA and phosphoric acid which are widely used in adhesive restoration system aimed to increase for retention of restorative materials, may act a chemical irritant that induce inflammation of dental pulp. Inflammation is a body response against irritant and infectious agents. Matrix metalloproteinase-8, the major collagenolytic enzyme, degrades collagen type 1. This enzyme is expressed in low level in normal condition, however, the expression will increase during inflammation. The purpose of the present research was to study the effect of 19% EDTA and 37% phosphoric acid application as an etching agents on the MMP-8 expression of dental pulp. Forty-five male Sprague Dawley rats were divided into 3 groups. Cavity preparation was made on the occlusal surface of maxillary first molar using a round diamond bur. 19% EDTA, 37% phosphoric acid, and distilled water were applied on the surface of the cavity of the teeth in group I, II, and III subsequently. The cavity then filed by glass ionomer cements. The rats were sacrified at 1, 3, 5, 7, and 14 days after the treatment (n=3 for each day. The specimens were then processed histologically. Immunohistochemical (IHC analysis was performed using rabbit anti rat MMP-8 polyclonal antibody to examine MMP-8 expression and HE (Hematoxylen Eosin staining to observe the number of macrophages. The results showed 37% phosphoric acid application induced stronger expression of MMP-8 and higher number of macrophages than 19% EDTA. The strongest expression of MMP-8 seems on 5 days after the treatment where the highest number of macrophages were also found.
A specific measurement matrix in compressive imaging system
Wang, Fen; Wei, Ping; Ke, Jun
2011-11-01
Compressed sensing or compressive sampling (CS) is a new framework for simultaneous data sampling and compression which was proposed by Candes, Donoho, and Tao several years ago. Ever since the advent of a single-pixel camera, one of the CS applications - compressive imaging (CI, also referred as feature-specific imaging) has aroused more interest of numerous researchers. However, it is still a challenging problem to choose a simple and efficient measurement matrix in such a hardware system, especially for large scale image. In this paper, we propose a new measurement matrix whose rows are the odd rows of N order Hadamard matrix and discuss the validity of the matrix theoretically. The advantage of the matrix is its universality and easy implementation in the optical domain owing to its integer-valued elements. In addition, we demonstrate the validity of the matrix through the reconstruction of natural images using Orthogonal Matching Pursuit (OMP) algorithm. Due to the limitation of the memory of the hardware system and personal computer which is used to simulate the process, it is impossible to create such a large matrix that is used to conduct large scale images. In order to solve the problem, the block-wise notion is introduced to conduct large scale images and the experiments results present the validity of this method.
Antioxidative Properties of Stearoyl Ascorbate in a Food Matrix System.
Wiboonsirikul, Jintana; Watanabe, Yoshiyuki; Omori, Ayako; Khuwijitjaru, Pramote; Adachi, Shuji
2016-06-01
Stearoyl ascorbate or 6-O-stearoyl l-ascorbate is a lipophilic derivative of l-ascorbic acid and is commercially used in foods as a fat-soluble antioxidant and surfactant to overcome the disadvantages of using l-ascorbic acid. The objective of this research is to evaluate the antioxidative ability of stearoyl ascorbate, in the presence of wheat starch or gluten as a matrix, by measuring the unoxidized methyl linoleate available in the mixture of them after oxidation under accelerated conditions compared to that when using ascorbic acid. We observed that stearoyl ascorbate and ascorbic acid exhibited mutually adjacent antioxidative ability against oxidation of the methyl linoleate at a molar ratio of 0.0001 in presence of either wheat starch or gluten. In addition, the oxidation process in the mixture containing either stearoyl ascorbate or ascorbic acid was significantly slower than that in the mixture without stearoyl ascorbate or ascorbic acid. Moreover, by altering the initiation and propagation periods of the oxidation process, the mixture containing the stearoyl ascorbate and gluten as the matrix exhibited conspicuously slower oxidation than the mixture containing either the wheat starch or stearoyl ascorbate alone. However, increase in the ratio of stearoyl ascorbate to methyl linoleate to 0.001 or higher resulted in adverse effects due to acceleration of the oxidation process.
Stationary density matrix of a pumped polariton system.
Vera, Carlos Andrés; Cabo, Alejandro; González, Augusto
2009-03-27
The density matrix rho of a model polariton system is obtained numerically from a master equation which takes account of pumping and losses. In the stationary limit, the coherences between eigenstates of the Hamiltonian are 3 orders of magnitude smaller than the occupations, meaning that the stationary density matrix is approximately diagonal in the energy representation. A weakly distorted grand canonical Gibbs distribution fits well the occupations.
Open quantum systems and random matrix theory
Mulhall, Declan
2014-10-01
A simple model for open quantum systems is analyzed with RMT. The system is coupled to the continuum in a minimal way. In this paper we see the effect of opening the system on the level statistics, in particular the level spacing, width distribution and Δ3(L) statistic are examined as a function of the strength of this coupling. The usual super-radiant state is observed, and it is seen that as it is formed, the level spacing and Δ3(L) statistic exhibit the signatures of missed levels.
Open quantum systems and random matrix theory
Energy Technology Data Exchange (ETDEWEB)
Mulhall, Declan [Department of Physics/Engineering, University of Scranton, Scranton, Pennsylvania 18510-4642 (United States)
2014-10-15
A simple model for open quantum systems is analyzed with RMT. The system is coupled to the continuum in a minimal way. In this paper we see the effect of opening the system on the level statistics, in particular the level spacing, width distribution and Δ{sub 3}(L) statistic are examined as a function of the strength of this coupling. The usual super-radiant state is observed, and it is seen that as it is formed, the level spacing and Δ{sub 3}(L) statistic exhibit the signatures of missed levels.
Hall, Christopher J; Boyle, Rachel H; Sun, Xueying; Wicker, Sophie M; Misa, June P; Krissansen, Geoffrey W; Print, Cristin G; Crosier, Kathryn E; Crosier, Philip S
2014-05-23
In addition to satisfying the metabolic demands of cells, mitochondrial metabolism helps regulate immune cell function. To date, such cell-intrinsic metabolic-immunologic cross-talk has only been described operating in cells of the immune system. Here we show that epidermal cells utilize fatty acid β-oxidation to fuel their contribution to the immune response during cutaneous inflammation. By live imaging metabolic and immunological processes within intact zebrafish embryos during cutaneous inflammation, we uncover a mechanism where elevated β-oxidation-fuelled mitochondria-derived reactive oxygen species within epidermal cells helps guide matrix metalloproteinase-driven leukocyte recruitment. This mechanism requires the activity of a zebrafish homologue of the mammalian mitochondrial enzyme, Immunoresponsive gene 1. This study describes the first example of metabolic reprogramming operating within a non-immune cell type to help control its contribution to the immune response. Targeting of this metabolic-immunologic interface within keratinocytes may prove useful in treating inflammatory dermatoses.
Nicolai, Eleonora; Sinibaldi, Federica; Sannino, Gianpaolo; Laganà, Giuseppina; Basoli, Francesco; Licoccia, Silvia; Cozza, Paola; Santucci, Roberto; Piro, Maria Cristina
2017-08-01
Polyunsaturated fatty acids have been reported to play a protective role in a wide range of diseases characterized by an increased metalloproteinases (MMPs) activity. The recent finding that omega-3 and omega-6 fatty acids exert an anti-inflammatory effect in periodontal diseases has stimulated the present study, designed to determine whether such properties derive from a direct inhibitory action of these compounds on the activity of MMPs. To this issue, we investigated the effect exerted by omega-3 and omega-6 fatty acids on the activity of MMP-2 and MMP-9, two enzymes that actively participate to the destruction of the organic matrix of dentin following demineralization operated by bacteria acids. Data obtained (both in vitro and on ex-vivo teeth) reveal that omega-3 and omega-6 fatty acids inhibit the proteolytic activity of MMP-2 and MMP-9, two enzymes present in dentin. This observation is of interest since it assigns to these compounds a key role as MMPs inhibitors, and stimulates further study to better define their therapeutic potentialities in carious decay.
Realization of Lossless Systems Via Constant Matrix Factorizations
Rapisarda, Paolo; Rao, Shodhan
2013-01-01
We study the realization problem for linear time-invariant systems described by higher-order differential equations, which are J-lossless with constant J. Our approach is based on the factorization of a constant matrix obtained in a straightforward way from the storage function of the system. State
Linear $r$-matrix algebra for classical separable systems
Eilbeck, J C; Kuznetsov, V B; Tsiganov, A V; Kuznetsov, Vadim B.
1994-01-01
We consider a hierarchy of the natural type Hamiltonian systems of $n$ degrees of freedom with polynomial potentials separable in general ellipsoidal and general paraboloidal coordinates. We give a Lax representation in terms of $2\\times 2$ matrices for the whole hierarchy and construct the associated linear $r$-matrix algebra with the $r$-matrix dependent on the dynamical variables. A Yang-Baxter equation of dynamical type is proposed. Using the method of variable separation we provide the integration of the systems in classical mechanics conctructing the separation equations and, hence, the explicit form of action variables. The quantisation problem is discussed with the help of the separation variables.
Degenerated-Inverse-Matrix-Based Channel Estimation for OFDM Systems
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Makoto Yoshida
2009-01-01
Full Text Available This paper addresses time-domain channel estimation for pilot-symbol-aided orthogonal frequency division multiplexing (OFDM systems. By using a cyclic sinc-function matrix uniquely determined by Nc transmitted subcarriers, the performance of our proposed scheme approaches perfect channel state information (CSI, within a maximum of 0.4 dB degradation, regardless of the delay spread of the channel, Doppler frequency, and subcarrier modulation. Furthermore, reducing the matrix size by splitting the dispersive channel impulse response into clusters means that the degenerated inverse matrix estimator (DIME is feasible for broadband, high-quality OFDM transmission systems. In addition to theoretical analysis on normalized mean squared error (NMSE performance of DIME, computer simulations over realistic nonsample spaced channels also showed that the DIME is robust for intersymbol interference (ISI channels and fast time-invariant channels where a minimum mean squared error (MMSE estimator does not work well.
Fukuyama, Yuko; Funakoshi, Natsumi; Takeyama, Kohei; Hioki, Yusaku; Nishikaze, Takashi; Kaneshiro, Kaoru; Kawabata, Shin-Ichirou; Iwamoto, Shinichi; Tanaka, Koichi
2014-02-18
Glycosylation and phosphorylation are important post-translational modifications in biological processes and biomarker research. The difficulty in analyzing these modifications is mainly their low abundance and dissociation of labile regions such as sialic acids or phosphate groups. One solution in matrix-assisted laser desorption/ionization (MALDI) mass spectrometry is to improve matrices for glycopeptides, carbohydrates, and phosphopeptides by increasing the sensitivity and suppressing dissociation of the labile regions. Recently, a liquid matrix 3-aminoquinoline (3-AQ)/α-cyano-4-hydroxycinnamic acid (CHCA) (3-AQ/CHCA), introduced by Kolli et al. in 1996, has been reported to increase sensitivity for carbohydrates or phosphopeptides, but it has not been systematically evaluated for glycopeptides. In addition, 3-AQ/CHCA enhances the dissociation of labile regions. In contrast, a liquid matrix 1,1,3,3-tetramethylguanidium (TMG, G) salt of p-coumaric acid (CA) (G3CA) was reported to suppress dissociation of sulfate groups or sialic acids of carbohydrates. Here we introduce a liquid matrix 3-AQ/CA for glycopeptides, carbohydrates, and phosphopeptides. All of the analytes were detected as [M + H](+) or [M - H](-) with higher or comparable sensitivity using 3-AQ/CA compared with 3-AQ/CHCA or 2,5-dihydroxybenzoic acid (2,5-DHB). The sensitivity was increased 1- to 1000-fold using 3-AQ/CA. The dissociation of labile regions such as sialic acids or phosphate groups and the fragmentation of neutral carbohydrates were suppressed more using 3-AQ/CA than using 3-AQ/CHCA or 2,5-DHB. 3-AQ/CA was thus determined to be an effective MALDI matrix for high sensitivity and the suppression of dissociation of labile regions in glycosylation and phosphorylation analyses.
Wallenius, Janne; Pahimanolis, Nikolaos; Zoppe, Justin; Kilpeläinen, Petri; Master, Emma; Ilvesniemi, Hannu; Seppälä, Jukka; Eerikäinen, Tero; Ojamo, Heikki
2015-12-01
The cell immobilization potential of a novel xylan based disulfide-crosslinked hydrogel matrix reinforced with cellulose nanocrystals was studied with continuous cultivation of Propionibacterium acidipropionici using various dilution rates. The cells were immobilized to hydrogel beads suspended freely in the fermentation broth or else packed into a column connected to a stirred tank reactor. The maximum propionic acid productivity for the combined stirred tank and column was 0.88gL(-1)h(-1) and the maximum productivity for the column was determined to be 1.39gL(-1)h(-1). The maximum propionic acid titer for the combined system was 13.9gL(-1) with a dilution rate of 0.06h(-1). Dry cell density of 99.7gL(-1) was obtained within the column packed with hydrogel beads and productivity of 1.02gL(-1)h(-1) was maintained in the column even with the high circulation rate of 3.37h(-1).
Quantum phase transitions about parity breaking in matrix product systems
Institute of Scientific and Technical Information of China (English)
ZHU Jing-Min
2011-01-01
According to our scheme to construct quantum phase transitions (QPTs) in spin chain systems with matrix product ground states, we first successfully combine matrix product state (MPS) QPTs with spontaneous symmetry breaking. For a concrete model, we take into account a kind of MPS QPTs accompanied by spontaneous parity breaking, though for either side of the critical point the GS is typically unique, and show that the kind of MPS QPTs occur only in the thermodynamic limit and are accompanied by the appearance of singularities, diverging correlation length, vanishing energy gap and the entanglement entropy of a half-infinite chain not only staying finite but also whose first derivative discontinuous.
Constrained Solutions of a System of Matrix Equations
Directory of Open Access Journals (Sweden)
Qing-Wen Wang
2012-01-01
Full Text Available We derive the necessary and sufficient conditions of and the expressions for the orthogonal solutions, the symmetric orthogonal solutions, and the skew-symmetric orthogonal solutions of the system of matrix equations AX=B and XC=D, respectively. When the matrix equations are not consistent, the least squares symmetric orthogonal solutions and the least squares skew-symmetric orthogonal solutions are respectively given. As an auxiliary, an algorithm is provided to compute the least squares symmetric orthogonal solutions, and meanwhile an example is presented to show that it is reasonable.
Matrix embedded microspherules containing indomethacin as controlled drug delivery systems.
Swamy, K M Lokamatha; Satyanath, B; Shantakumar, S M; Manjula, D; Mohammedi, Hafsa; Farhana, Ayesha
2008-10-01
This work is focused on the development of controlled drug delivery systems using different wax/fat embedded indomethacin (IM). Discrete wax/fat embedded microspherules containing indomethacin were prepared by using cetostearyl alcohol, paraffin wax and stearic acid by employing emulsification-phase separation method. These matrices have been used as barrier coatings due to their hydrophobic nature. Chemically inert and tasteless nature of wax/fats promotes their use as taste masking agents for bitter drugs. Various waxes and fats are available having different physicochemical properties to suit the needs of formulation. Methyl cellulose (MC) 1% w/v, sodium alginate (SA) 0.5% w/v and Tween-80 (TW) 1% w/v were used as emulgents. The resulting microspherules were discrete, large, spherical and also free flowing. It is revealed from the literature that natures of wax/fat emulgents were found to influence the rate of drug release. In the present work the drug content in all the batches of microspherules were found to be uniform. The rate of drug release corresponded best to first order kinetics, followed by Higuchi and zero-order equations. The release of the model drug from these wax/fat microspherules was prolonged over an extended period of time and the drug release mechanism followed anomalous (non-Fickian) diffusion controlled as well as Super Case II transport. Among the three matrix materials used, paraffin wax retarded the drug release more than the other two. Surface characteristics of microspherules have been studied by Scanning Electron Microscope (SEM). A fair degree rank of correlation was found to exist between the size and release retardation in all the three-wax/fat emulgent combinations.
Ohta, Yuki; Iwamoto, Shinichi; Kawabata, Shin-ichirou; Tanimura, Ritsuko; Tanaka, Koichi
2014-01-01
Mass spectrometry (MS) is a highly sensitive analytical technique that is often coupled with liquid chromatography (LC). However, some buffering salts used in LC (e.g., phosphate and tris(hydroxymethyl)aminomethane (Tris)) are incompatible with MS since they cause ion-source contamination and signal suppression. In this study, we examined salt tolerance of MALDI and applied a matrix additive methylenediphosphonic acid (MDPNA) to reduce salt-induced signal suppression. MDPNA significantly improved the salt tolerance of MALDI-MS. Using ammonium formate buffer at pH 5.0, the effective range of buffering salt concentration in MALDI-MS using MDPNA was estimated up to 250 mM. MDPNA reduced signal suppression caused by buffering salts at pH 4.0 to 8.0. We observed that MDPNA effectively worked over a wide range of buffer conditions. MDPNA was further applied to hydrophilic interaction chromatography (HILIC) and chromatofocusing-MALDI-MS. As a result, the analytes in the eluent containing high-concentration salts were detected with high sensitivity. Thus, our study provides simple and fast LC-MALDI-MS analysis technique not having strict limitation of buffering condition in LC by using matrix additive MDPNA. PMID:26819873
Optimization of MIMO Systems Capacity Using Large Random Matrix Methods
Directory of Open Access Journals (Sweden)
Philippe Loubaton
2012-11-01
Full Text Available This paper provides a comprehensive introduction of large random matrix methods for input covariance matrix optimization of mutual information of MIMO systems. It is first recalled informally how large system approximations of mutual information can be derived. Then, the optimization of the approximations is discussed, and important methodological points that are not necessarily covered by the existing literature are addressed, including the strict concavity of the approximation, the structure of the argument of its maximum, the accuracy of the large system approach with regard to the number of antennas, or the justification of iterative water-filling optimization algorithms. While the existing papers have developed methods adapted to a specific model, this contribution tries to provide a unified view of the large system approximation approach.
Matrix sentence intelligibility prediction using an automatic speech recognition system.
Schädler, Marc René; Warzybok, Anna; Hochmuth, Sabine; Kollmeier, Birger
2015-01-01
The feasibility of predicting the outcome of the German matrix sentence test for different types of stationary background noise using an automatic speech recognition (ASR) system was studied. Speech reception thresholds (SRT) of 50% intelligibility were predicted in seven noise conditions. The ASR system used Mel-frequency cepstral coefficients as a front-end and employed whole-word Hidden Markov models on the back-end side. The ASR system was trained and tested with noisy matrix sentences on a broad range of signal-to-noise ratios. The ASR-based predictions were compared to data from the literature ( Hochmuth et al, 2015 ) obtained with 10 native German listeners with normal hearing and predictions of the speech intelligibility index (SII). The ASR-based predictions showed a high and significant correlation (R² = 0.95, p speech and noise signals. Minimum assumptions were made about human speech processing already incorporated in a reference-free ordinary ASR system.
Simulating quantum systems on classical computers with matrix product states
Energy Technology Data Exchange (ETDEWEB)
Kleine, Adrian
2010-11-08
In this thesis, the numerical simulation of strongly-interacting many-body quantum-mechanical systems using matrix product states (MPS) is considered. Matrix-Product-States are a novel representation of arbitrary quantum many-body states. Using quantum information theory, it is possible to show that Matrix-Product-States provide a polynomial-sized representation of one-dimensional quantum systems, thus allowing an efficient simulation of one-dimensional quantum system on classical computers. Matrix-Product-States form the conceptual framework of the density-matrix renormalization group (DMRG). After a general introduction in the first chapter of this thesis, the second chapter deals with Matrix-Product-States, focusing on the development of fast and stable algorithms. To obtain algorithms to efficiently calculate ground states, the density-matrix renormalization group is reformulated using the Matrix-Product-States framework. Further, time-dependent problems are considered. Two different algorithms are presented, one based on a Trotter decomposition of the time-evolution operator, the other one on Krylov subspaces. Finally, the evaluation of dynamical spectral functions is discussed, and a correction vector-based method is presented. In the following chapters, the methods presented in the second chapter, are applied to a number of different physical problems. The third chapter deals with the existence of chiral phases in isotropic one-dimensional quantum spin systems. A preceding analytical study based on a mean-field approach indicated the possible existence of those phases in an isotropic Heisenberg model with a frustrating zig-zag interaction and a magnetic field. In this thesis, the existence of the chiral phases is shown numerically by using Matrix-Product-States-based algorithms. In the fourth chapter, we propose an experiment using ultracold atomic gases in optical lattices, which allows a well controlled observation of the spin-charge separation (of
Transfer Matrix Method for Natural Vibration Analysis of Tree System
Directory of Open Access Journals (Sweden)
Bin He
2012-01-01
Full Text Available The application of Transfer matrix method (TMM ranges from linear/nonlinear vibration, composite structure, and multibody system to calculating static deformation, natural vibration, dynamical response, and damage identification. Generally TMM has two characteristics: (1 the TMM formulae share similarity to the chain mechanics model in terms of topology structure; then TMM often is selected as a powerful tool to analyze the chain system. (2 TMM is adopted to deal with the problems of the discrete system, continuous system, and especial discrete/continuous coupling system with the uniform matrix form. In this investigation, a novel TMM is proposed to analyze the natural vibration of the tree system. In order to make the TMM of the tree system have the two above advantages of the TMM of the chain system, the suitable state vectors and transfer matrices of the typical components of the tree system are constructed. Then the topology comparability between the mechanics model and its corresponding formulae of TMM can be adopted to assembling the transfer matrices and transfer equations of the global tree system. Two examples of natural vibration problems validating the method are given. The formulation of the proposed TMM is mathematically intuitive and can be held and applied by the engineers easily.
Computing the structural influence matrix for biological systems.
Giordano, Giulia; Cuba Samaniego, Christian; Franco, Elisa; Blanchini, Franco
2016-06-01
We consider the problem of identifying structural influences of external inputs on steady-state outputs in a biological network model. We speak of a structural influence if, upon a perturbation due to a constant input, the ensuing variation of the steady-state output value has the same sign as the input (positive influence), the opposite sign (negative influence), or is zero (perfect adaptation), for any feasible choice of the model parameters. All these signs and zeros can constitute a structural influence matrix, whose (i, j) entry indicates the sign of steady-state influence of the jth system variable on the ith variable (the output caused by an external persistent input applied to the jth variable). Each entry is structurally determinate if the sign does not depend on the choice of the parameters, but is indeterminate otherwise. In principle, determining the influence matrix requires exhaustive testing of the system steady-state behaviour in the widest range of parameter values. Here we show that, in a broad class of biological networks, the influence matrix can be evaluated with an algorithm that tests the system steady-state behaviour only at a finite number of points. This algorithm also allows us to assess the structural effect of any perturbation, such as variations of relevant parameters. Our method is applied to nontrivial models of biochemical reaction networks and population dynamics drawn from the literature, providing a parameter-free insight into the system dynamics.
Multipole Matrix Elements for Dh-Systems and Their Asymptotics
Tarasov, V. F.
A “DH-system” is defined as a multidimensional hydrogen atom (or its one-particle analogue), D≥1. Investigating many Coulomb problems in ℝD it is necessary to know exact analytical expressions of multipole matrix elements D for DH-systems, where q=(N, µ) is a set of parameters, N —"principal” and µ — "orbital” quantum numbers. The paper deals with the new method for the evaluation of similar matrix elements using new properties of Appell’s function F2(x, y) to the vicinity of the singular point (1, 1). Such approach allows: 1) to get exact analytical expressions of these matrix elements (considering the selection rules) by means of Appell’s F2 (or Clausen’s 3F2) functions; 2) to reveal “latent” symmetry of diagonal matrix elements with respect to the point k0=-3/2, the above symmetry is connected with the property of Appell’s function F2 (1,1) mirror-like symmetry; 3) to find (exact) asymptotics of the off-diagonal matrix elements in terms of Horn’s function ψ1 (x, y); 4) to prove that the orthogonality of radial functions fNµ (D, r) over N and μ for DH-systems is connected with the properties of Appell’s F2 function to the vicinity of the singular point (1, 1), it generalizes the known result for 3H-atom by Pasternack and Sternheimer, J. Math. Phys. 3, 1280 (1962).
THE BONUS-MALUS SYSTEM MODELLING USING THE TRANSITION MATRIX
Directory of Open Access Journals (Sweden)
SANDRA TEODORESCU
2012-05-01
Full Text Available The motor insurance is an important branch of non-life insurance in many countries; in some of them, coming first in total premium income category (in Romania, for example. The Bonus-Malus system implementation is one of the solutions chosen by the insurance companies in order to increase the efficiency in the motor insurance domain. This system has been recently introduced by the Romanian insurers as well. In this paper I present the means for modelling the bonus-malus system using the transition matrix.
Enzyme system comprising an enzyme bonded in a porous matrix
Ackerman, Eric [Richland, WA; Liu, Jun [West Richland, WA
2010-12-07
A protein system is described in which a protein is bound within a matrix material that has pores that are sized to achieve excellent properties such as: activity, protein density, and stability. In a preferred embodiment, the pore sizes range from 50 to 400 .ANG.. One protein that has demonstrated surprisingly good results in this system is OPH. This protein is known to degrade organophosphorus compounds such as are found in chemical weapons and pesticides. Novel methods of forming the protein system and methods of making OPH are also described.
Dynamical simulations of classical stochastic systems using matrix product states.
Johnson, T H; Clark, S R; Jaksch, D
2010-09-01
We adapt the time-evolving block decimation (TEBD) algorithm, originally devised to simulate the dynamics of one-dimensional quantum systems, to simulate the time evolution of nonequilibrium stochastic systems. We describe this method in detail; a system's probability distribution is represented by a matrix product state (MPS) of finite dimension and then its time evolution is efficiently simulated by repeatedly updating and approximately refactorizing this representation. We examine the use of MPS as an approximation method, looking at parallels between the interpretations of applying it to quantum state vectors and probability distributions. In the context of stochastic systems we consider two types of factorization for use in the TEBD algorithm: non-negative matrix factorization (NMF), which ensures that the approximate probability distribution is manifestly non-negative, and the singular value decomposition (SVD). Comparing these factorizations, we find the accuracy of the SVD to be substantially greater than current NMF algorithms. We then apply TEBD to simulate the totally asymmetric simple exclusion process (TASEP) for systems of up to hundreds of lattice sites in size. Using exact analytic results for the TASEP steady state, we find that TEBD reproduces this state such that the error in calculating expectation values can be made negligible even when severely compressing the description of the system by restricting the dimension of the MPS to be very small. Out of the steady state we show for specific observables that expectation values converge as the dimension of the MPS is increased to a moderate size.
Bonferoni, MC; Rossi, S; Ferrari, F; Bertoni, M; Bolhuis, GK; Caramella, C
1998-01-01
The lambda carrageenan/HPMC ratio in matrix tablets has been optimized in order to obtain pH-independent release profiles of chlorpheniramine maleate, a freely soluble drug. Release profiles in acidic (pH 1.2) and neutral (pH 6.8) media were fitted according to the Weibull and the power law models.
Sparse matrix methods research using the CSM testbed software system
Chu, Eleanor; George, J. Alan
1989-01-01
Research is described on sparse matrix techniques for the Computational Structural Mechanics (CSM) Testbed. The primary objective was to compare the performance of state-of-the-art techniques for solving sparse systems with those that are currently available in the CSM Testbed. Thus, one of the first tasks was to become familiar with the structure of the testbed, and to install some or all of the SPARSPAK package in the testbed. A suite of subroutines to extract from the data base the relevant structural and numerical information about the matrix equations was written, and all the demonstration problems distributed with the testbed were successfully solved. These codes were documented, and performance studies comparing the SPARSPAK technology to the methods currently in the testbed were completed. In addition, some preliminary studies were done comparing some recently developed out-of-core techniques with the performance of the testbed processor INV.
Decoherence in chaotic and integrable systems: a random matrix approach
Gorin, T.; Seligman, T. H.
2003-03-01
We study the influence of chaos and order on entanglement and decoherence. In view of applications in quantum computing and teleportation which should be able to work with arbitrarily complicated states, we pay particular attention to the behavior of random states. While studies with coherent states indicate that chaos accelerates decoherence and entanglement, we find that there is practically no difference between the chaotic and the integrable case, as far as random states are concerned. In the present studies we use unitary time evolution of the total system, and partial traces to emulate decoherence. Random matrix models are a natural choice to describe the dynamics of random states. The invariant aspects of chaos and order are then reflected in the different spectral statistics. We develop random matrix models for the evolution of entanglement for a large variety of situations, discussing the strong coupling case in full detail.
Decoherence in chaotic and integrable systems: a random matrix approach
Energy Technology Data Exchange (ETDEWEB)
Gorin, T.; Seligman, T.H
2003-03-17
We study the influence of chaos and order on entanglement and decoherence. In view of applications in quantum computing and teleportation which should be able to work with arbitrarily complicated states, we pay particular attention to the behavior of random states. While studies with coherent states indicate that chaos accelerates decoherence and entanglement, we find that there is practically no difference between the chaotic and the integrable case, as far as random states are concerned. In the present studies we use unitary time evolution of the total system, and partial traces to emulate decoherence. Random matrix models are a natural choice to describe the dynamics of random states. The invariant aspects of chaos and order are then reflected in the different spectral statistics. We develop random matrix models for the evolution of entanglement for a large variety of situations, discussing the strong coupling case in full detail.
Localized motion in random matrix decomposition of complex financial systems
Jiang, Xiong-Fei; Zheng, Bo; Ren, Fei; Qiu, Tian
2017-04-01
With the random matrix theory, we decompose the multi-dimensional time series of complex financial systems into a set of orthogonal eigenmode functions, which are classified into the market mode, sector mode, and random mode. In particular, the localized motion generated by the business sectors, plays an important role in financial systems. Both the business sectors and their impact on the stock market are identified from the localized motion. We clarify that the localized motion induces different characteristics of the time correlations for the stock-market index and individual stocks. With a variation of a two-factor model, we reproduce the return-volatility correlations of the eigenmodes.
Response matrix of an extended Bonner sphere system
Vylet, V
2002-01-01
We have developed a system of Bonner spheres designed for use around high-energy accelerators. The upper energy limit of the system was extended using a lead radiator, which acts as an energy converter via the (n,xn) reaction. In addition, we use sup 1 sup 1 C activation as an additional component integrated into the system and the spectra unfolding process. In the first version of the system, the lead radiator was present in only one sphere with diameter of 30.48 cm. The object of the present work was to investigate the geometry of the lead radiator and its use in moderators of several different sizes. As a result, we have developed a modular design and calculated the response matrix of the new system.
A ceramic matrix composite thermal protection system for hypersonic vehicles
Riccitiello, Salvatore R.; Love, Wendell L.; Pitts, William C.
1993-01-01
The next generation of hypersonic vehicles (NASP, SSTO) that require reusable thermal protection systems will experience acreage surface temperatures in excess of 1100 C. More important, they will experience a more severe physical environment than the Space Shuttle due to non-pristine launching and landing conditions. As a result, maintenance, inspection, and replacement factors must be more thoroughly incorporated into the design of the TPS. To meet these requirements, an advanced thermal protection system was conceived, designated 'TOPHAT'. This system consists of a toughened outer ceramic matrix composite (CMC) attached to a rigid reusable surface insulator (RSI) which is directly bonded to the surface. The objective of this effort was to evaluate this concept in an aeroconvective environment, to determine the effect of impacts to the CMC material, and to compare the results with existing thermal protection systems.
EFFECT OF ACIDITY ON ACID-SENSITIVE UV CURING SYSTEM
Institute of Scientific and Technical Information of China (English)
Qi-dao Chen; Bing Wu; Xiao-yin Hong
1999-01-01
By using diphenyliodonium salts with different counterions as photo acid generators (PAGs), the effect of acidity on ring-opening polymerization of epoxy monomers and polycondensation of polyol with hexamethoxymethyl melamine (HMMM) was studied. The result shows that the rate of ring-opening polymerization is evidently dependent on the acidity of the acid and strong photo-generated acid is required.However, there is a leveling effect in the polycondensation system; if the photo-generated acid is stronger than protonated HMMM, the acidity does not obviously affect the polycondensation rate.
Effect of Matrix Modification on Durability of Cementitious Composites in an Acid Rain Environment
Institute of Scientific and Technical Information of China (English)
HE Kui; YANG Hui; LU Zhenbao; JIA Fangfang; WANG Erpo; DONG Quanxiao
2014-01-01
The durability of silane-modified mortar, a cementitious composite, in acid rain environment was investigated given its extensive usage as a structural material. The results indicated that the addition of silane decreased the compressive strength of the cementitious composite. Wetting angle was increased by incorporating silane into the matrix. Decrease in both water absorption ability and coefficient of capillary suction confirmed hydrophobicity as induced by silane addition. Results of mechanical testing, scanning electron microscopy and X-ray diffraction showed that the sulfuric acid resistance of mortar was enhanced by silane. Based on these results, it is revealed that silane addition inhibits the diffusion of water, and consequently, sulfate ion diffusion rate decreases, thereby resulting in reduction in the rate of corrosion of cementitious composites by sulfuric acid.
MALDI mechanism of dihydroxybenzoic acid isomers: desorption of neutral matrix and analyte.
Liang, Chi Wei; Lee, Chih Hao; Lin, Yu-Jiun; Lee, Yuan Tseh; Ni, Chi Kung
2013-05-01
Angular resolved velocity distributions of laser desorbed neutral matrices (dihydroxybenzoic acids, DHB) and analytes (tryptophan) embedded in these matrices were investigated at 322 nm by a modified crossed molecular beam apparatus. Desorbed ions generated from MALDI were measured by a time-of-flight mass spectrometer. Desorptions of neutral matrix and analyte from 2,3-DHB, 2,4-DHB, 2,5-DHB, 2,6-DHB, and 3,5--DHB at 322 nm have similar properties, but the ion intensities are in the order 2,3DHB ≅ 2,6-DHB > 2,5-DHB ≅ 2,4-DHB > 3,5-DHB. It indicates that the combination of various parameters related to neutral species, including absorption coefficient, sublimation energy, contact of analyte and matrix in crystal, and plume dynamics of desorbed species are not crucial in the determination of MALDI process for DHB isomers. The difference of matrix activity of DHB isomers at this wavelength must result from the other properties, like the excited state lifetime, proton affinity, gas-phase basicity, acidity, ionization energy, or the other properties related to the primary reactions in ion generation.
Energy Technology Data Exchange (ETDEWEB)
Park, Kyung Man; Ahn, Sung Hee; Bae, Yong Jin; Kim, Myung Soo [Seoul National Univ., Seoul (Korea, Republic of)
2013-03-15
Numbers of matrix- and analyte-derived ions and their sum in matrix-assisted laser desorption ionization (MALDI) of a peptide were measured using 2,5-dihydroxybenzoic acid (DHB) as matrix. As for MALDI with α-cyano-4-hydroxy cinnamic acid as matrix, the sum was independent of the peptide concentration in the solid sample, or was the same as that of pure DHB. This suggested that the matrix ion was the primary ion and that the peptide ion was generated by matrix-to-peptide proton transfer. Experimental ionization efficiencies of 10{sup -5}-10{sup -4} for peptides and 10{sup -8}-10{sup -7} for matrices are far smaller than 10.3-10.1 for peptides and 10{sup -5}-10{sup -3} for matrices speculated by Hillenkamp and Karas. Number of gas-phase ions generated by MALDI was unaffected by laser wavelength or pulse energy. This suggests that the main role of photo-absorption in MALDI is not in generating ions via a multi-photon process but in ablating materials in a solid sample to the gas phase.
Nucleic acid based logical systems.
Han, Da; Kang, Huaizhi; Zhang, Tao; Wu, Cuichen; Zhou, Cuisong; You, Mingxu; Chen, Zhuo; Zhang, Xiaobing; Tan, Weihong
2014-05-12
Researchers increasingly visualize a significant role for artificial biochemical logical systems in biological engineering, much like digital logic circuits in electrical engineering. Those logical systems could be utilized as a type of servomechanism to control nanodevices in vitro, monitor chemical reactions in situ, or regulate gene expression in vivo. Nucleic acids (NA), as carriers of genetic information with well-regulated and predictable structures, are promising materials for the design and engineering of biochemical circuits. A number of logical devices based on nucleic acids (NA) have been designed to handle various processes for technological or biotechnological purposes. This article focuses on the most recent and important developments in NA-based logical devices and their evolution from in vitro, through cellular, even towards in vivo biological applications.
Biological studies of matrix metalloproteinase sensitive drug delivery systems
DEFF Research Database (Denmark)
Johansen, Pia Thermann
due to severe side effects as a result of drug distribution to healthy tissues. To enhance ecacy of treatment and improve life quality of patients, tumor specific drug delivery strategies, such as liposome encapsulated drugs, which accumulate in tumor tissue, has gained increased attention. Several...... for delivery of drugs to specific tissues or cells utilizing biological knowledge of cancer tissue is getting increased attention. In this thesis a novel matrix metalloproteinase-2 (MMP-2) sensitive poly-ethylene glycol (PEG) coated liposomal drug delivery system for treatment of cancer was developed...... the use of MMP- 2 as a trigger for liposomal activation in tumor tissue. Thus, this new strategy provides a promising system for specific delivery of encapsulated drugs and controlled release in tumor tissues, resulting in enhanced drug bioavailability and decreased systemic side effects. In addition, we...
Regulation of ovarian function by the matrix metalloproteinase system
Institute of Scientific and Technical Information of China (English)
无
2002-01-01
@@ In most organs of mammals, cyclic remodelling of tissues after morphogenesis is minimal; however, repro-ductive tissues of female animals including endometrium, mammary gland, ovarian follicle and corpus luteum un-dergo growth, maturation and involution at various stages in the reproductive cycle or lifespan of the animal. Recon-struction of the extracellular matrix (ECM) is required for the dynamic tissue reorganization characteristic of these tissues. The ECM consists of proteinaceous and nonpro-teinaceous molecules that provide the tissue-specific, ex-tracellular architecture to which cells attach. Furthermore, interaction of cellular receptors with proteins of the ECM can regulate cellular structure, second messenger genera-tion and gene expression. Maintenance of ECM homeo-stasis depends largely on coordinated action of matrix metalloproteinases (MMPs) and tissue inhibitors of met-alloproteinases (TIMPs)-- an important proteinase sys-tem responsible for degradating and remodelling of ECM[1]. MMPs/TIMPs have been recognized as the cru-cial role players in regulating follicular and luteal function for their extensive involvements in the cyclic changes of dynamic ovarian tissues. In recent years, literature that MMP system has important roles in ovary is accumulating. The focus of this review is on the effects of MMPs and their inhibitors, TIMPs on follicular growth, atresia, ovu-lation, luteal development, and luteolysis. Emphasis has been given to the recent progress in the new field when-ever possible.
Energy Technology Data Exchange (ETDEWEB)
Paredes, Eduardo [Departamento de Quimica Analitica, Nutricion y Bromatologia, University of Alicante, 03080 Alicante (Spain); Maestre, Salvador E. [Departamento de Quimica Analitica, Nutricion y Bromatologia, University of Alicante, 03080 Alicante (Spain); Todoli, Jose L. [Departamento de Quimica Analitica, Nutricion y Bromatologia, University of Alicante, 03080 Alicante (Spain)]. E-mail: jose.todoli@ua.es
2006-03-15
A stirred tank was used for the first time to elucidate the mechanism responsible for inductively coupled plasma atomic emission spectroscopy (ICP-AES) matrix effects caused by inorganic, acids and easily ionized elements (EIEs), as well as organic, ethanol and acetic acid, compounds. In order to gradually increase the matrix concentration, a matrix solution was introduced inside a stirred container (tank) initially filled with an aqueous multielement standard. PolyTetraFluoroEthylene (PTFE) tubing was used to deliver the resulting solution to the liquid sample introduction system. Matrix concentration ranged from 0 to 2 mol l{sup -1} in the case of inorganic acids (i.e., nitric, sulfuric, hydrochloric and a mixture of them), from 0 to about 2500 mg l{sup -1} for EIEs (i.e., sodium, calcium and mixtures of both) and from 0% to 15%, w/w for organic compounds. Up to 40-50 different solutions were prepared and measured in a period of time shorter than 6-7 min. This investigation was carried out in terms of emission intensity and tertiary aerosols characteristics. The experimental setup used in the present work allowed to thoroughly study the effect of matrix concentration on analytical signal. Generally speaking, the experiments concerning tertiary aerosol characterization revealed that, in the case of inorganic acids and EIEs, the mechanism responsible for changes in aerosol characteristics was the droplet fission. In contrast, for organic matrices it was found that the interference was caused by a change in both aerosol transport and plasma thermal characteristics. The extent of the interferences caused by organic as well as inorganic compounds was compared for a set of 14 emission lines through a wide range of matrix concentrations. With a stirred tank, it is possible to choose an efficient internal standard for any given matrix composition. The time required to complete this procedure was shorter than 7 min.
Theoretical Studies of the Relaxation Matrix for Molecular Systems
Ma, Qiancheng; Boulet, C.
2016-06-01
The phenomenon of collisional transfer of intensity due to line mixing has an increasing importance for atmospheric monitoring. From a theoretical point of view, all relevant information about the collisional processes is contained in the relaxation matrix where the diagonal elements give half-widths and shifts, and the off-diagonal elements correspond to line interferences. For simple systems such as those consisting of diatom-atom or diatom-diatom, accurate fully quantum calculations based on interaction potentials are feasible. However, fully quantum calculations become unrealistic for more complex systems. On the other hand, the semi-classical Robert-Bonamy formalism, which has been widely used to calculate half-widths and shifts for decades, fails in calculating the off-diagonal matrix elements resulting from applying the isolated line approximation. As a result, in order to simulate atmospheric spectra where the effects from line mixing are important, semi-empirical fitting or scaling laws such as the energy corrected sudden (ECS) and the infinite order sudden (IOS) models are commonly used. Recently, we have found that in developing this semi-classical line shape theory, to rely on the isolated line approximation is not necessary. By eliminating this unjustified assumption, and accurately evaluating matrix elements of the exponential operators, we have developed a more capable formalism that enables one not only to reduce uncertainties for calculated half-widths and shifts, but also to calculate the whole relaxation matrix. This implies that we can address the line mixing with the semi-classical theory based on interaction potentials between molecular absorber and molecular perturber. We have applied this formalism for Raman and infrared spectra of linear and asymmetric-top molecules. Recently, the method has been extended into symmetric-tops with inverse symmetry such as the NH3 molecule. Our calculated half-widths of NH3 lines in the νb{1} and the pure
Quantum Phase Transitions in Conventional Matrix Product Systems
Zhu, Jing-Min; Huang, Fei; Chang, Yan
2017-02-01
For matrix product states(MPSs) of one-dimensional spin-1/2 chains, we investigate a new kind of conventional quantum phase transition(QPT). We find that the system has two different ferromagnetic phases; on the line of the two ferromagnetic phases coexisting equally, the system in the thermodynamic limit is in an isolated mediate-coupling state described by a paramagnetic state and is in the same state as the renormalization group fixed point state, the expectation values of the physical quantities are discontinuous, and any two spin blocks of the system have the same geometry quantum discord(GQD) within the range of open interval (0,0.25) and the same classical correlation(CC) within the range of open interval (0,0.75) compared to any phase having no any kind of correlation. We not only realize the control of QPTs but also realize the control of quantum correlation of quantum many-body systems on the critical line by adjusting the environment parameters, which may have potential application in quantum information fields and is helpful to comprehensively and deeply understand the quantum correlation, and the organization and structure of quantum correlation especially for long-range quantum correlation of quantum many-body systems.
Evaluating mirror alignment systems using the optical sensing matrix
Energy Technology Data Exchange (ETDEWEB)
Mantovani, M [Universita di Siena, INFN Pisa (Italy); Freise, A [School of Physics and Astronomy, University of Birmingham, Edgbaston, Birmingham B15 2TT (United Kingdom)], E-mail: mantovan@ego-gw.it
2008-07-15
The most sensitive gravitational-wave detectors today are based on large-scale laser interferometers whose optics are suspended from pendulums to decouple the instrument from seismic motion. Complex control systems are required to set and maintain the microscopic position of each mirror at a precisely defined value. Such control systems use the interferometer signals as input signals, and ideally it is designed such that the degrees of freedom (mirror positions) are well decoupled in the interferometer signals. However, this is not always feasible, in particular the mirror alignment control signals in interferometric gravitational wave detectors often show strong couplings between the different degrees of freedom. In this paper we will describe a simple and powerful method to quantify in advance the performances of an alignment control system by analyzing the optical matrix of the proposed read-out system. We will motivate the method using a Fabry-Perot cavity as an example, and we will further present results for the Virgo alignment system where this method was used to characterize and improve the alignment sensing scheme.
Random matrix theory for pseudo-Hermitian systems: Cyclic blocks
Indian Academy of Sciences (India)
Sudhir R Jain; Shashi C L Srivastava
2009-12-01
We discuss the relevance of random matrix theory for pseudo-Hermitian systems, and, for Hamiltonians that break parity and time-reversal invariance . In an attempt to understand the random Ising model, we present the treatment of cyclic asymmetric matrices with blocks and show that the nearest-neighbour spacing distributions have the same form as obtained for the matrices with scalar entries. We also summarize the theory for random cyclic matrices with scalar entries. We have also found that for block matrices made of Hermitian and pseudo-Hermitian sub-blocks of the form appearing in Ising model depart from the known results for scalar entries. However, there is still similarity in trends even in log–log plots.
Constantinou, Costas; Koutsidis, Georgios
2016-04-15
The formation of acrylamide in model Maillard reaction systems containing phenolic compounds was examined, with regards to phenolic type, concentration, and model system matrix. In dry glyoxal/asparagine waxy maize starch (WMS) systems, 9 out of 10 examined phenolics demonstrated an inhibiting effect, with the most significant reductions (55-60%) observed for caffeoylquinic acids. In WMS glucose/asparagine systems, examination of three different concentrations (0.1, 0.5 and 1 μmol/g WMS) suggested a 'minimum effective concentration' for epicatechin and caffeic acid, whilst addition of caffeoylquinic acids resulted in dose-dependent acrylamide reduction (25-75%). The discordant results of further studies utilising different matrices (dry and wet-to-dry) indicated that, apart from the nature and chemical reactivity, the matrix and the physical state of the reactants might be important for acrylamide formation.
Energy Technology Data Exchange (ETDEWEB)
Aguilera, Angeles [Centro de Astrobiologia (INTA-CSIC), Carretera de Ajalvir Km 4, Torrejon de Ardoz, 28850 Madrid (Spain)], E-mail: aguileraba@inta.es; Souza-Egipsy, Virginia [Centro de Astrobiologia (INTA-CSIC), Carretera de Ajalvir Km 4, Torrejon de Ardoz, 28850 Madrid (Spain); San Martin-Uriz, Patxi [Centro de Biologia Molecular (UAM-CSIC), Universidad Autonoma de Madrid, Cantoblanco, 28049 Madrid (Spain); Amils, Ricardo [Centro de Astrobiologia (INTA-CSIC), Carretera de Ajalvir Km 4, Torrejon de Ardoz, 28850 Madrid (Spain); Centro de Biologia Molecular (UAM-CSIC), Universidad Autonoma de Madrid, Cantoblanco, 28049 Madrid (Spain)
2008-07-30
To evaluate the importance of the extracellular matrix in relation to heavy metal binding capacity in extreme acidic environments, the extracellular polymeric substances (EPS) composition of 12 biofilms isolated from Rio Tinto (SW, Spain) was analyzed. Each biofilm was composed mainly by one or two species of eukaryotes, although other microorganisms were present. EPS ranged from 130 to 439 mg g{sup -1} biofilm dry weight, representing between 15% and the 40% of the total biofilm dry weight (DW). Statistically significant differences (p < 0.05) were found in the amount of total EPS extracted from biofilms dominated by the same organism at different sampling points. The amount of EPS varied among different biofilms collected from the same sampling location. Colloidal EPS ranged from 42 to 313 mg g{sup -1} dry weight; 10% to 30% of the total biofilm dry weight. Capsular EPS ranged from 50 to 318 mg g{sup -1} dry weight; 5% to 30% of the total biofilm dry weight. Seven of the 12 biofilms showed higher amounts of capsular than colloidal EPS (p < 0.05). Total amount of EPS decreased when total cell numbers and pH increased. There was a positive correlation between EPS concentration and heavy metal concentration in the water. Observations by low temperature scanning electron microscopy (LTSEM) revealed the mineral adsorption in the matrix of EPS and onto the cell walls. EPS in all biofilms were primarily composed of carbohydrates, heavy metals and humic acid, plus small quantities of proteins and DNA. After carbohydrates, heavy metals were the second main constituents of the extracellular matrix. Their total concentrations ranged from 3 to 32 mg g{sup -1} biofilm dry weight, reaching up to 16% of the total composition. In general, the heavy metal composition of the EPS extracted from the biofilms closely resembled the metal composition of the water from which the biofilms were collected.
Stokes-Mueller matrix polarimetry system for glucose sensing
Phan, Quoc-Hung; Lo, Yu-Lung
2017-05-01
A Stokes-Mueller matrix polarimetry system consisting of a polarization scanning generator (PSG) and a high-accuracy Stokes polarimeter is used to sense the glucose concentration in aqueous solutions with and without scattering effects, respectively. In the proposed system, an electro-optic (EO) modulator driven by a saw-tooth waveform voltage is used to perform full state of polarization (linear/circular) scanning, while a self-built Stokes polarimeter is used to obtain dynamic measurements of the output polarized light intensity. It is shown that the measured output Stokes vectors have an accuracy of 10-4, i.e., one order higher than that of existing commercial Stokes polarimeters. The experimental results show that the optical rotation angle varies linearly with the glucose concentration over the range of 0-0.5 g/dl. Moreover, glucose sensing is successfully achieved at concentrations as low as 0.02 g/dl with a resolution of 10-6 deg/mm and an average deviation of 10-4 deg. In general, the polarimetry system proposed in this study provides a fast and reliable method for measuring the Stokes vectors, and thus has significant potential for biological sensing applications.
Superabsorbent biphasic system based on poly(lactic acid) and poly(acrylic acid)
Sartore, Luciana; Pandini, Stefano; Baldi, Francesco; Bignotti, Fabio
2016-05-01
In this research work, biocomposites based on crosslinked particles of poly(acrylic acid), commonly used as superabsorbent polymer (SAP), and poly-L-lactic acid (PLLA) were developed to elucidate the role of the filler (i.e., polymeric crosslinked particles) on the overall physico-mechanical behavior and to obtain superabsorbent thermoplastic products. Samples prepared by melt-blending of components in different ratios showed a biphasic system with a regular distribution of particles, with diameter ranging from 5 to 10 μm, within the PLLA polymeric matrix. The polymeric biphasic system, coded PLASA i.e. superabsorbent poly(lactic acid), showed excellent swelling properties, demonstrating that cross-linked particles retain their superabsorbent ability, as in their free counterparts, even if distributed in a thermoplastic polymeric matrix. The thermal characteristics of the biocomposites evidence enhanced thermal stability in comparison with neat PLLA and also mechanical properties are markedly modified by addition of crosslinked particles which induce regular stiffening effect. Furthermore, in aqueous environments the particles swell and are leached from PLLA matrix generating very high porosity. These new open-pore PLLA foams, produced in absence of organic solvents and chemical foaming agents, with good physico-mechanical properties appear very promising for several applications, for instance in tissue engineering for scaffold production.
Institute of Scientific and Technical Information of China (English)
ZHU Jing-Min
2011-01-01
According to our scheme to construct quantum phase transitions （QPTs） in spin chain systems with matrix product ground states, we first successfully combine matrix product state （MPS） QPTs with spontaneous symmetry breaking. For a concrete model, we take
Calvano, Cosima Damiana; Ventura, Giovanni; Palmisano, Francesco; Cataldi, Tommaso R I
2016-09-01
4-Chloro-α-cyanocinnamic acid (ClCCA) is a very useful matrix able to give the protonated adduct [M+H](+) of intact cyanocobalamin (CNCbl) as the base peak (m/z 1355.58) in matrix-assisted laser desorption/ionization (MALDI) mass spectrometry (MS). The only fragment observed is [M-CN + H](+•) formed through the facile (•) CN neutral loss reflecting the fairly low Co-C bond energy. All other investigated proton transfer matrices, including α-cyano-4-hydroxycinnamic acid, para-nitroaniline and 2,5-dihydroxybenzoic acid, give rise to a complete decyanation of CNCbl with concomitant formation of [M-CN + H](+•) , [M-CN + Na](+•) and [M-CN + K](+•) adducts at m/z 1329.57, 1351.55 and 1367.51, respectively. Depending on the matrix used, a variable degree of fragmentation involving the α-side axial ligand was observed. A plausible explanation of the specific behaviour of 4-chloro-α-cyanocinnamic acid as a soft matrix is discussed. Tandem mass spectra of both [M + H](+) and [M-CN + H](+•) ions were obtained and product ions successfully assigned. The possibility of detecting the protonated adduct of intact CNCbl was exploited in foodstuff samples such as cow milk and hen egg yolk by MALDI tandem MS upon sample extraction. We believe that our data provide strong basis for the application of MALDI tandem MS in the qualitative analysis of natural CNCbl, including fish, liver and meat samples. Copyright © 2016 John Wiley & Sons, Ltd.
Marie, Benjamin; Luquet, Gilles; Pais De Barros, Jean-Paul; Guichard, Nathalie; Morel, Sylvain; Alcaraz, Gérard; Bollache, Loïc; Marin, Frédéric
2007-06-01
Among molluscs, the shell biomineralization process is controlled by a set of extracellular macromolecular components secreted by the calcifying mantle. In spite of several studies, these components are mainly known in bivalves from only few members of pteriomorph groups. In the present case, we investigated the biochemical properties of the aragonitic shell of the freshwater bivalve Unio pictorum (Paleoheterodonta, Unionoida). Analysis of the amino acid composition reveals a high amount of glycine, aspartate and alanine in the acid-soluble extract, whereas the acid-insoluble one is rich in alanine and glycine. Monosaccharidic analysis indicates that the insoluble matrix comprises a high amount of glucosamine. Furthermore, a high ratio of the carbohydrates of the soluble matrix is sulfated. Electrophoretic analysis of the acid-soluble matrix revealed discrete bands. Stains-All, Alcian Blue, periodic acid/Schiff and autoradiography with (45)Ca after electrophoretic separation revealed three major polyanionic calcium-binding glycoproteins, which exhibit an apparent molecular mass of 95, 50 and 29 kDa, respectively. Two-dimensional gel electrophoresis shows that these bands, provisionally named P95, P50 and P29, are composed of numerous isoforms, the majority of which have acidic isoelectric points. Chemical deglycosylation of the matrix with trifluoromethanesulfonic acid induces a drastic shift of both the apparent molecular mass and the isoelectric point of these matrix components. This treatment induces also a modification of the shape of CaCO(3) crystals grown in vitro and a loss of the calcium-binding ability of two of the main matrix proteins (P95 and P50). Our findings strongly suggest that post-translational modifications display important functions in mollusc shell calcification.
PHARMACODYNAMICAL EVALUATION OF MATRIX TYPE TRANSDERMAL THERAPEUTIC SYSTEMS CONTAINING CAPTOPRIL.
Kerımoğlu, Oya; Şahbaz, Sevınç; Şehırlı, Özer; Ozdemır, Zarıfe Nıgar; Çetınel, Şule; Dortunç, Betül; Şener, Göksel
2015-01-01
The objective of this study was to evaluate pharmacodynamical properties of transdermal therapeutic systems (TTS) containing captopril together with synthetic and pH independent polymers, Eudragit RL 100 and RS 100. Optimum formulation was chosen according to the results of our previous study regarding in vitro dissolution and ex vivo diffusion rate studies through excised human skin by using Franz Diffusion Cell. Control group, hypertension group (HT) and TTS containing captopril hypertension group (HT-CAP) were assessed for the pharmacodynamic activity of the study. Pharmacodynamic activity of transdermal patches containing captopril was evaluated in rats by the measurement of systolic blood pressure for 24 h with the use of the tail cuff method. Blood pressure, heart rate, body and heart weight, heart and body weight ratio were determined. Lactate dehydrogenase (LDH), creatinine phosphokinase (CPK), glutathione (GSH), malondialdehyde (MDA), myeloperoxidase (MPO) and Na+, K(+)-ATPase were measured in the serum of rats. Histopathological evaluation of the heart tissue was conducted in order to determine any tissue damage. Blood pressure values of the TTS containing captopril hypertension group were decreased significantly and became almost similar with the blood pressure values of the control group. These results indicated that matrix type transdermal patches prepared with Eudragit RL 100 and RS 100 polymers containing captopril can be considered as transdermal therapeutic systems for chronical treatment of hypertension and congestive heart failure. However, further in vivo pharmacokinetic studies should be performed in order to determine the blood level of the drug.
Hypohalous acids contribute to renal extracellular matrix damage in experimental diabetes.
Brown, Kyle L; Darris, Carl; Rose, Kristie Lindsey; Sanchez, Otto A; Madu, Hartman; Avance, Josh; Brooks, Nickolas; Zhang, Ming-Zhi; Fogo, Agnes; Harris, Raymond; Hudson, Billy G; Voziyan, Paul
2015-06-01
In diabetes, toxic oxidative pathways are triggered by persistent hyperglycemia and contribute to diabetes complications. A major proposed pathogenic mechanism is the accumulation of protein modifications that are called advanced glycation end products. However, other nonenzymatic post-translational modifications may also contribute to pathogenic protein damage in diabetes. We demonstrate that hypohalous acid-derived modifications of renal tissues and extracellular matrix (ECM) proteins are significantly elevated in experimental diabetic nephropathy. Moreover, diabetic renal ECM shows diminished binding of α1β1 integrin consistent with the modification of collagen IV by hypochlorous (HOCl) and hypobromous acids. Noncollagenous (NC1) hexamers, key connection modules of collagen IV networks, are modified via oxidation and chlorination of tryptophan and bromination of tyrosine residues. Chlorotryptophan, a relatively minor modification, has not been previously found in proteins. In the NC1 hexamers isolated from diabetic kidneys, levels of HOCl-derived oxidized and chlorinated tryptophan residues W(28) and W(192) are significantly elevated compared with nondiabetic controls. Molecular dynamics simulations predicted a more relaxed NC1 hexamer tertiary structure and diminished assembly competence in diabetes; this was confirmed using limited proteolysis and denaturation/refolding. Our results suggest that hypohalous acid-derived modifications of renal ECM, and specifically collagen IV networks, contribute to functional protein damage in diabetes.
Burgain, J; Scher, J; Francius, G; Borges, F; Corgneau, M; Revol-Junelles, A M; Cailliez-Grimal, C; Gaiani, C
2014-11-01
This review gives an overview of the importance of interactions occurring in dairy matrices between Lactic Acid Bacteria and milk components. Dairy products are important sources of biological active compounds of particular relevance to human health. These compounds include immunoglobulins, whey proteins and peptides, polar lipids, and lactic acid bacteria including probiotics. A better understanding of interactions between bioactive components and their delivery matrix may successfully improve their transport to their target site of action. Pioneering research on probiotic lactic acid bacteria has mainly focused on their host effects. However, very little is known about their interaction with dairy ingredients. Such knowledge could contribute to designing new and more efficient dairy food, and to better understand relationships between milk constituents. The purpose of this review is first to provide an overview of the current knowledge about the biomolecules produced on bacterial surface and the composition of the dairy matter. In order to understand how bacteria interact with dairy molecules, adhesion mechanisms are subsequently reviewed with a special focus on the environmental conditions affecting bacterial adhesion. Methods dedicated to investigate the bacterial surface and to decipher interactions between bacteria and abiotic dairy components are also detailed. Finally, relevant industrial implications of these interactions are presented and discussed.
Tagler, David; Makanji, Yogeshwar; Tu, Tao; Bernabé, Beatriz Peñalver; Lee, Raymond; Zhu, Jie; Kniazeva, Ekaterina; Hornick, Jessica E; Woodruff, Teresa K; Shea, Lonnie D
2014-07-01
The in vitro growth of ovarian follicles is an emerging technology for fertility preservation. Various strategies support the culture of secondary and multilayer follicles from various species including mice, non-human primate, and human; however, the culture of early stage (primary and primordial) follicles, which are more abundant in the ovary and survive cryopreservation, has been limited. Hydrogel-encapsulating follicle culture systems that employed feeder cells, such as mouse embryonic fibroblasts (MEFs), stimulated the growth of primary follicles (70-80 µm); yet, survival was low and smaller follicles (structure and degenerated. These morphologic changes were associated with a breakdown of the follicular basement membrane; hence, this study investigated ascorbic acid based on its role in extracellular matrix (ECM) deposition/remodeling for other applications. The selection of ascorbic acid was further supported by a microarray analysis that suggested a decrease in mRNA levels of enzymes within the ascorbate pathway between primordial, primary, and secondary follicles. The supplementation of ascorbic acid (50 µg/mL) significantly enhanced the survival of primary follicles (alginate hydrogels, which coincided with improved structural integrity. Follicles developed antral cavities and increased to diameters exceeding 250 µm. Consistent with improved structural integrity, the gene/protein expression of ECM and cell adhesion molecules was significantly changed. This research supports the notion that modifying the culture environment (medium components) can substantially enhance the survival and growth of early stage follicles. © 2013 Wiley Periodicals, Inc.
Iterative linear system solvers with approximate matrix-vector products
Eshof, J. van den; Sleijpen, G.L.G.; Gijzen, M.B. van
2003-01-01
There are classes of linear problems for which a matrix-vector product is a time consuming operation because an expensive approximation method is required to compute it to a given accuracy. One important example is simulations in lattice QCD with Neuberger fermions where a matrix multiply
Directory of Open Access Journals (Sweden)
Sette Alessandro
2009-11-01
Full Text Available Abstract Background Experts in peptide:MHC binding studies are often able to estimate the impact of a single residue substitution based on a heuristic understanding of amino acid similarity in an experimental context. Our aim is to quantify this measure of similarity to improve peptide:MHC binding prediction methods. This should help compensate for holes and bias in the sequence space coverage of existing peptide binding datasets. Results Here, a novel amino acid similarity matrix (PMBEC is directly derived from the binding affinity data of combinatorial peptide mixtures. Like BLOSUM62, this matrix captures well-known physicochemical properties of amino acid residues. However, PMBEC differs markedly from existing matrices in cases where residue substitution involves a reversal of electrostatic charge. To demonstrate its usefulness, we have developed a new peptide:MHC class I binding prediction method, using the matrix as a Bayesian prior. We show that the new method can compensate for missing information on specific residues in the training data. We also carried out a large-scale benchmark, and its results indicate that prediction performance of the new method is comparable to that of the best neural network based approaches for peptide:MHC class I binding. Conclusion A novel amino acid similarity matrix has been derived for peptide:MHC binding interactions. One prominent feature of the matrix is that it disfavors substitution of residues with opposite charges. Given that the matrix was derived from experimentally determined peptide:MHC binding affinity measurements, this feature is likely shared by all peptide:protein interactions. In addition, we have demonstrated the usefulness of the matrix as a Bayesian prior in an improved scoring-matrix based peptide:MHC class I prediction method. A software implementation of the method is available at: http://www.mhc-pathway.net/smmpmbec.
Gojgini, Shiva; Tokatlian, Talar; Segura, Tatiana
2011-10-01
The effective delivery of DNA locally would increase the applicability of gene therapy in tissue regeneration, where diseased tissue is to be repaired in situ. One promising approach is to use hydrogel scaffolds to encapsulate and deliver plasmid DNA in the form of nanoparticles to the diseased tissue, so that cells infiltrating the scaffold are transfected to induce regeneration. This study focuses on the design of a DNA nanoparticle-loaded hydrogel scaffold. In particular, this study focuses on understanding how cell-matrix interactions affect gene transfer to adult stem cells cultured inside matrix metalloproteinase (MMP) degradable hyaluronic acid (HA) hydrogel scaffolds. HA was cross-linked to form a hydrogel material using a MMP degradable peptide and Michael addition chemistry. Gene transfer inside these hydrogel materials was assessed as a function of polyplex nitrogen to phosphate ratio (N/P = 5 to 12), matrix stiffness (100-1700 Pa), RGD (Arg-Gly-Asp) concentration (10-400 μM), and RGD presentation (0.2-4.7 RGDs per HA molecule). All variables were found to affect gene transfer to mouse mensenchymal stem cells culture inside the DNA loaded hydrogels. As expected, higher N/P ratios lead to higher gene transfer efficiency but also higher toxicity; softer hydrogels resulted in higher transgene expression than stiffer hydrogels, and an intermediate RGD concentration and RGD clustering resulted in higher transgene expression. We believe that the knowledge gained through this in vitro model can be utilized to design better scaffold-mediated gene delivery for local gene therapy.
Tezvergil-Mutluay, Arzu; Agee, Kelli A; Hoshika, Tomohiro; Tay, Franklin R; Pashley, David H
2010-10-01
This study has examined the use of polyvinylphosphonic acid (PVPA) as a potential matrix metalloproteinase (MMP) inhibitor and how brief cross-linking of demineralized dentin matrix that did not affect its mechanical properties enhanced the anti-MMP activity of PVPA. The anti-MMP potential of five PVPA concentrations (100-3000 microgml(-1)) was initially screened using a rhMMP-9 colorimetic assay. Demineralized dentin beams were treated with the same five concentrations of PVPA to collagen and then aged for 30 days in a calcium- and zinc-containing medium. The changes in modulus of elasticity, loss of dry mass and dissolution of collagen peptides were measured via three-point bending, precision weighing and hydroxyproline assay, respectively. All tested PVPA concentrations were highly effective (P<0.05) in inhibiting MMP-9. Ageing in the incubation medium did not significantly alter the modulus of elasticity of the five PVPA treatment groups. Conversely, aged dentin beams from the control group exhibited a significant decline in their modulus of elasticity (P<0.05) over time. Mass loss from the dentin beams and the corresponding increase in hydroxyproline in the medium in the five PVPA treatment groups were significantly lower than for the control (P<0.05). PVPA is a potent inhibitor of endogenous MMP activities in demineralized dentin. It may be used as an alternative to chlorhexidine to prevent collagen degradation within hybrid layers to extend the longevity of resin-dentin bonds.
Martin, Patrick; Van Mooy, Benjamin A S
2013-01-01
Polyphosphate (polyP) is a ubiquitous biochemical with many cellular functions and comprises an important environmental phosphorus pool. However, methodological challenges have hampered routine quantification of polyP in environmental samples. We tested 15 protocols to extract inorganic polyphosphate from natural marine samples and cultured cyanobacteria for fluorometric quantification with 4',6-diamidino-2-phenylindole (DAPI) without prior purification. A combination of brief boiling and digestion with proteinase K was superior to all other protocols, including other enzymatic digestions and neutral or alkaline leaches. However, three successive extractions were required to extract all polyP. Standard addition revealed matrix effects that differed between sample types, causing polyP to be over- or underestimated by up to 50% in the samples tested here. Although previous studies judged that the presence of DNA would not complicate fluorometric quantification of polyP with DAPI, we show that RNA can cause significant interference at the wavelengths used to measure polyP. Importantly, treating samples with DNase and RNase before proteinase K digestion reduced fluorescence by up to 57%. We measured particulate polyP along a North Pacific coastal-to-open ocean transect and show that particulate polyP concentrations increased toward the open ocean. While our final method is optimized for marine particulate matter, different environmental sample types may need to be assessed for matrix effects, extraction efficiency, and nucleic acid interference.
Das, Raghunath; Pal, Sagar
2015-01-01
Hydroxypropyl methyl cellulose has been modified by grafting synthetic polyacrylamide chains [g-HPMC (M)] in presence of microwave irradiation, which has used as carrier for controlled release of 5-amino salicylic acid (5-ASA). The FTIR and UV-vis-NIR studies reveal the excellent compatibility between g-HPMC (M) and 5-ASA. Field emission scanning electron microscopy (FESEM) and UV-vis-NIR analyses suggest that physical interaction predominates between the drug and matrix. % equilibrium swelling ratio (% ESR) of g-HPMC (M) decreased with addition of salt solutions and follow the order: Na(+)>K(+)>Mg(2+)>Ca(2+)>Al(3+). The in vitro 5-ASA release studies indicate that g-HPMC (M) delivers the drug preferentially in colonic region in more sustained way than that of HPMC. The 5-ASA release follows first order kinetics and non-Fickian diffusion mechanism. These favorable features make the graft copolymer a potential matrix for colon specific delivery of 5-ASA.
Institute of Scientific and Technical Information of China (English)
无
2006-01-01
Tb(Ⅲ)-trimesic acid (TMA) luminescent complexes were synthesized in the polyvinylpyrrolidone (PVP) matrix. The elemental analysis, inductively coupled plasma-atomic emission spectroscopy (ICP-AES) and fourier-transform infrared spectroscopy (FT-IR) indicated that its chemical constitution is PVP/Tb(MTA)·4H2O. The XRD patterns showed that the complex is a new kind of crystal. The TEM image indicates that the complex is rod shaped. The rod diameter is about 200 nm, and the length ranges from hundred of nanometer to a few micrometers. In addition, the dispersity is better. TG-DTA curves indicate that the complex is thermally stable before 463 ℃. Photoluminescence analysis indicates that the complex emits Tb3+ characteristic luminescence under ultraviolet excitation.
Directory of Open Access Journals (Sweden)
Mariateresa Giustiniano
2013-01-01
Full Text Available A number of matrix metalloproteinases (MMPs are important medicinal targets for conditions ranging from rheumatoid arthritis to cardiomyopathy, periodontal disease, liver cirrhosis, multiple sclerosis, and cancer invasion and metastasis, where they showed to have a dual role, inhibiting or promoting important processes involved in the pathology. MMPs contain a zinc (II ion in the protein active site. Small-molecule inhibitors of these metalloproteins are designed to bind directly to the active site metal ions. In an effort to devise new approaches to selective inhibitors, in this paper, we describe the synthesis and preliminary biological evaluation of amino acid derivatives as new zinc binding groups (ZBGs. The incorporation of selected metal-binding functions in more complex biphenyl sulfonamide moieties allowed the identification of one compound able to interact selectively with different MMP enzymatic isoforms.
Xiang, Lei; Chen, Lei; Xiao, Tao; Mo, Ce-Hui; Li, Yan-Wen; Cai, Quan-Ying; Li, Hui; Zhou, Dong-Mei; Wong, Ming-Hung
2017-10-04
A robust method was developed for simultaneous determination of nine trace perfluoroalkyl carboxylic acids (PFCAs) in various edible crop matrices including cereal (grain), root vegetable (carrot), leafy vegetable (lettuce), and melon vegetable (pumpkin) using ultrasonic extraction followed by solid-phase extraction cleanup and high liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). The varieties of extractants and cleanup cartridges, the usage of Supelclean graphitized carbon, and the matrix effect and its potential influencing factors were estimated to gain an optimal extraction procedure. The developed method presented high sensitivity and accuracy with the method detection limits and the recoveries at four fortification levels in various matrices ranging from 0.017 to 0.180 ng/g (dry weight) and from 70% to 114%, respectively. The successful application of the developed method to determine PFCAs in various crops sampled from several farms demonstrated its practicability for regular monitoring of PFCAs in real crops.
Wu, C-W; Kang, Chao-Hsiang; Lin, Yi-Feng; Tung, Kuo-Lun; Deng, Yu-Heng; Ahamad, Tansir; Alshehri, Saad M; Suzuki, Norihiro; Yamauchi, Yusuke
2016-04-01
Prussian blue (PB) nanoparticles, one of many cyano-bridged coordination polymers, are successfully incorporated into chitosan (CS) polymer to prepare PB/CS mixed matrix membranes (MMMs). The PB nanoparticles are uniformly distributed in the MMMs without the collapse of the original PB structure. As-prepared PB/CS MMMs are used for ethanol dehydration at 25 °C in the pervaporation process. The effect of loading PB in CS matrix on pervaporation performance is carefully investigated. The PB/CS membrane with 30 wt% PB loading shows the best performance with a permeate flux of 614 g. m-2 . h-1 and a separation factor of 1472. The pervaporation using our PB/CS membranes exhibits outstanding performance in comparison with the previously reported CS-based membranes and MMMs. Furthermore, the addition of PB allows PB/CS MMMs to be tolerant of acidic environment. The present work demonstrates good pervaporation performance of PB/CS MMMs for the separation of an ethanol/water (90:10 in wt%) solution. Our new system provides an opportunity for dehydration of bioethanol in the future.
Direct Measurement of the Density Matrix of a Quantum System
Thekkadath, G. S.; Giner, L.; Chalich, Y.; Horton, M. J.; Banker, J.; Lundeen, J. S.
2016-09-01
One drawback of conventional quantum state tomography is that it does not readily provide access to single density matrix elements since it requires a global reconstruction. Here, we experimentally demonstrate a scheme that can be used to directly measure individual density matrix elements of general quantum states. The scheme relies on measuring a sequence of three observables, each complementary to the last. The first two measurements are made weak to minimize the disturbance they cause to the state, while the final measurement is strong. We perform this joint measurement on polarized photons in pure and mixed states to directly measure their density matrix. The weak measurements are achieved using two walk-off crystals, each inducing a polarization-dependent spatial shift that couples the spatial and polarization degrees of freedom of the photons. This direct measurement method provides an operational meaning to the density matrix and promises to be especially useful for large dimensional states.
Matrix factorization method for the Hamiltonian structure of integrable systems
Indian Academy of Sciences (India)
S Ghosh; B Talukdar; S Chakraborti
2003-07-01
We demonstrate that the process of matrix factorization provides a systematic mathematical method to investigate the Hamiltonian structure of non-linear evolution equations characterized by hereditary operators with Nijenhuis property.
Experimental results for improving the matrix condition using a hybrid optical system.
Klapp, Iftach; Mendlovic, David
2012-03-01
We present preliminary experimental results for implementing the "blurred trajectories" method on three parallel optics (PO) systems. The "main" system and "auxiliary" optics were simple laboratory graded lenses attached to an iris diaphragm. When applying the blurred trajectories method we first show an improvement in the matrix condition, as the matrix condition number decreased in a range of factors of 3 to 418 relative to the main system. Following that, image restoration by weak regularization was performed so that the system matrix condition dominated the restoration process. It was shown that the restoration results of the PO are better than those of the main system and the auxiliary optics separately. In addition, the quality of the restoration follows the system's matrix condition. The improvement in the matrix condition achieved by the PO system improved the immunity to detection noise. Finally, a comparison to Wiener filtering restoration shows that it is also generally inferior to the proposed method.
Li, Dan; Hui, Rui; Hu, Yongwu; Han, Yan; Guo, Shuzhong
2015-01-01
To investigate the effects of Dragon' s blood extract on proliferation and secret extracellular matrix function of fibroblasts in vitro. Dragon' s blood was extracted by chloroform, acetoacetic ester, alcohol. Human fibroblast were cultured in vitro in media containing gradient dilutions of Dragon' s blood extracts (0.002, 0.02, 0.2, 2, 20 mg/ml) , which was followed by cell proliferation assessed with MTT assay on 0, 12, 24, 36, 48, 60, 72 h. Under the optimal concentration, the cell growth curves were drawn and the flow cytometry (FCM) was used to determine the changes of cell cycle. On 0, 12, 24, 36, 48, 60, 72 h, the concentration of hyaluronic acid in the supernatant of fibroblast culture was measured by radioimmunoassay. 0.2-2 mg/ml Dragon' s blood extracts enhanced the proliferation of fibroblasts in a dose-dependent manner. 2 mg/ml was the optimal dilution of Dragon's blood extract, and it increased the ratio of S cells in cell cycle [(25.80 ± 3.10)%] than control group [(7.50 ± 0.70)%, P Dragon's blood group, concentration of Hyaluronic acid secreted by fibroblasts gradually increased, but were less than control (P Dragon's blood acetoacetic ester extract improved the proliferation of cultured human fibroblasts in vitro, might be beneficial to promote wound healing.
Knight, J Diane; Cessna, Allan J; Ngombe, Dean; Wolfe, Tom M
2016-10-01
Biobeds are used for on-farm bioremediation of pesticides in sprayer rinsate and from spills during sprayer filling. Using locally sourced materials from Saskatchewan, Canada, a biobed matrix was evaluated for its effectiveness for mineralising and degrading 2,4-dichlorophenoxyacetic acid dimethylamine salt (2,4-D DMA) compared with the topsoil used in the biobed matrix. Applying 2,4-D DMA to the biobed matrix caused a 2-3 day lag in CO2 production not observed when the herbicide was applied to topsoil. Despite the initial lag, less residual 2,4-D was measured in the biobed (0%) matrix than in the topsoil (57%) after a 28 day incubation. When the herbicide was applied 5 times to the biobed matrix, net CO2 increased immediately after each 2,4-D DMA application. Mineralisation of 2,4-D DMA was 61.9% and residual 2,4-D in the biobed matrix was 0.3% after 60 days, compared with corresponding values of 32.9 and 70.9% in topsoil. The biobed matrix enhanced the mineralisation and degradation of 2,4-D DMA, indicating the potential for successful implementation of biobeds under Canadian conditions. The biobed matrix was more effective for mineralising and degrading the herbicide compared with the topsoil used in the biobed matrix. By correcting for biobed matrix and formulation blank, CO2 evolution was a reliable indicator of 2,4-D DMA mineralisation. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.
Soy matrix drug delivery systems obtained by melt-processing techniques
Vaz, C.M.; Doeveren, van P.F.N.M.; Reis, R.L.; Cunha, A.M.
2003-01-01
The aim of this study was to develop new soy protein drug delivery matrix systems by melt-processing techniques, namely, extrusion and injection moulding. The soy matrix systems with an encapsulated drug (theophylline, TH) were previously compounded by extrusion performed at two different pH values,
Linear Matrix Inequalities for Analysis and Control of Linear Vector Second-Order Systems
DEFF Research Database (Denmark)
Adegas, Fabiano Daher; Stoustrup, Jakob
2015-01-01
the Lyapunov matrix and the system matrices by introducing matrix multipliers, which potentially reduce conservativeness in hard control problems. Multipliers facilitate the usage of parameter-dependent Lyapunov functions as certificates of stability of uncertain and time-varying vector second-order systems...
Secreted protein acidic and rich in cysteine is a matrix scavenger chaperone.
Directory of Open Access Journals (Sweden)
Alexandre Chlenski
Full Text Available Secreted Protein Acidic and Rich in Cysteine (SPARC is one of the major non-structural proteins of the extracellular matrix (ECM in remodeling tissues. The functional significance of SPARC is emphasized by its origin in the first multicellular organisms and its high degree of evolutionary conservation. Although SPARC has been shown to act as a critical modulator of ECM remodeling with profound effects on tissue physiology and architecture, no plausible molecular mechanism of its action has been proposed. In the present study, we demonstrate that SPARC mediates the disassembly and degradation of ECM networks by functioning as a matricellular chaperone. While it has low affinity to its targets inside the cells where the Ca(2+ concentrations are low, high extracellular concentrations of Ca(2+ activate binding to multiple ECM proteins, including collagens. We demonstrated that in vitro, this leads to the inhibition of collagen I fibrillogenesis and disassembly of pre-formed collagen I fibrils by SPARC at high Ca(2+ concentrations. In cell culture, exogenous SPARC was internalized by the fibroblast cells in a time- and concentration-dependent manner. Pulse-chase assay further revealed that internalized SPARC is quickly released outside the cell, demonstrating that SPARC shuttles between the cell and ECM. Fluorescently labeled collagen I, fibronectin, vitronectin, and laminin were co-internalized with SPARC by fibroblasts, and semi-quantitative Western blot showed that SPARC mediates internalization of collagen I. Using a novel 3-dimensional model of fluorescent ECM networks pre-deposited by live fibroblasts, we demonstrated that degradation of ECM depends on the chaperone activity of SPARC. These results indicate that SPARC may represent a new class of scavenger chaperones, which mediate ECM degradation, remodeling and repair by disassembling ECM networks and shuttling ECM proteins into the cell. Further understanding of this mechanism may provide
Institute of Scientific and Technical Information of China (English)
Jian Tang; Jing-Wen Niu; Dong-Hui Xu; Zhi-Xing Li; Qi-Fu Li; Jin-An Chen
2007-01-01
accompanied by the configurational changes of nuclear matrix-intermediate filament (NM-IF)system and the compositional changes of nuclear matrix protein expression. These changes may be important morphological or functional indications of the cancer cell reversion.
Matrix formulation of a universal microbial transcript profiling system
Energy Technology Data Exchange (ETDEWEB)
Fitch, J P; Ng, J; Sokhansanj, B A
2000-11-01
DNA chips and microarrays are used to profile gene transcription. Unfortunately, the initial fabrication cost for a chip and the reagent costs to amplify thousands of open reading frames for a microarray are over $100K for a typical 4 Mbase bacterial genome. To avoid these expensive steps, a matrix formulation of a universal hybrid chip-microarray approach to transcript profiling is demonstrated for synthetic data. Initial considerations for application to the 4.3 Mbase bacterium Yersinia pestis are also presented. This approach can be applied to arbitrary bacteria by recalculating a matrix and pseudoinverse. This approach avoids the large upfront expenses associated with DNA chips and microarrays.
Inactivation of Matrix-bound MMPs by Cross-linking Agents in Acid Etched Dentin
Scheffel, Débora Lopes Salles; Hebling, Josimeri; Scheffel, Régis Henke; Agee, Kelly A.; Turco, Gianluca; de Souza Costa, Carlos Alberto; Pashley, David H.
2014-01-01
Objectives Published TEM analysis of in vivo resin-dentin bonds shows that in 44 months almost 70% of collagen fibrils from the hybrid layer disappear. Matrix metalloproteinases (MMPs) play an important role in that process and are thought to be the main factor responsible for the solubitization of dentin collagen. Therefore, this study aimed to evaluate the inactivation of matrix-bound MMPs by carbodiimide (EDC) or proanthocyanidin (PA) both cross-linking agents, or the MMP-inhibitor, chlorhexidine (CHX), on acid-etched dentin using a simplified MMP assay method. Methods Dentin beams (1×1×6mm) were obtained from mid-coronal dentin of sound third molars and randomly divided into 6 groups (G) according to the dentin treatment: G1: Deionized water (control), G2: 0.1M EDC, G3: 0.5M EDC, G4: 0.5M EDC+35% HEMA, G5: 5% Proanthocyanidin (PA) and G6: 2% CHX. The beams were etched for 15s with 37% phosphoric acid, rinsed and then immersed for 60s in one of the treatment solutions. The total MMP activity of dentin was analyzed for 1 h by colorimetric assay (Sensolyte). Data were submitted to Wilcoxon non-parametric test and Mann-Whitney tests (p>0.05). Results All experimental cross-linking solutions significantly reduced MMP activity compared to control, except 0.1M EDC (53.6% ±16.1). No difference was observed between cross-linking agents and 2% CHX 0.5M EDC + 35% HEMA (92.3% ±8.0) was similar to 0.5M EDC (89.1% ±6.4), 5% PA (100.8% ±10.9) and 2% CHX (83.4% ±10.9). Conclusion Dentin treatment with cross-linking agents is effective to significantly reduce MMP activity. Mixing 0.5M EDC and 35% HEMA did not influence EDC inhibitor potential. PMID:23786610
Directory of Open Access Journals (Sweden)
T. F. Marinina
2014-01-01
Full Text Available Timeliness of double-layer matrix system (of stomatological medicated films with antiinflammatory, local anesthetic, regenerative, anti-edematous action was shown. One layer of the system includes lidocaine hydrochloride and kalanchoe sap, another contains furacilin and urea. The best possible polymer carriers of preparations under study which provide their sufficient release from matrix system. Signified antimicrobic activity of double-layer system and osmotic activity were established. Double-layer matrix systems offered may be used in stomatology with for treatment and preventive measures of different diseases of parodontium tissues
Gorbuzov, V N
2011-01-01
The questions of global topological, smooth and holomorphic classifications of the differential systems, defined by covering foliations, are considered. The received results are applied to nonautonomous linear differential systems and projective matrix Riccati equations.
Some open problems in random matrix theory and the theory of integrable systems
Deift, Percy
2007-01-01
We describe a list of open problems in random matrix theory and integrable systems which was presented at the conference ``Integrable Systems, Random Matrices, and Applications'' at the Courant Institute in May 2006.
Some open problems in random matrix theory and the theory of integrable systems
Deift, Percy
2007-01-01
We describe a list of open problems in random matrix theory and integrable systems which was presented at the conference ``Integrable Systems, Random Matrices, and Applications'' at the Courant Institute in May 2006.
On the Formulation of Flexible Multibody Systems with Constant Mass Matrix
DEFF Research Database (Denmark)
Pedersen, Niels Leergaard
1997-01-01
A flexible body in a multibody system isdescribed only by the position of the nodes in theinertial frame. With this description we can formulatethe mass matrix of the flexible multibody as aconstant matrix. This matrix can be inverted in apreprocessing stage which yields a more efficientaccelerat...... of this formulation is that neither thecentrifugal nor the Coriolis forces appear in theequations due to the description of the flexible body....
Directory of Open Access Journals (Sweden)
Baohong Jiang
Full Text Available Cardiac fibrosis is a deleterious consequence of hypertension which may further advance to heart failure and increased matrix metalloproteinase-9 (MMP-9 contributes to the underlying mechanism. Therefore, new therapeutic strategies to attenuate the effects of MMP-9 are urgently needed. In the present study, we characterize salvianolic acid A (SalA as a novel MMP-9 inhibitor at molecular, cellular and animal level. We expressed a truncated form of MMP-9 which contains only the catalytic domain (MMP-9 CD, and used this active protein for enzymatic kinetic analysis and Biacore detection. Data generated from these assays indicated that SalA functioned as the strongest competitive inhibitor of MMP-9 among 7 phenolic acids from Salvia miltiorrhiza. In neonatal cardiac fibroblast, SalA inhibited fibroblast migration, blocked myofibroblast transformation, inhibited secretion of intercellular adhesion molecule (ICAM, interleukin-6 (IL-6 and soluble vascular cell adhesion molecule-1 (sVCAM-1 as well as collagen induced by MMP-9 CD. Functional effects of SalA inhibition on MMP-9 was further confirmed in cultured cardiac H9c2 cell overexpressing MMP-9 in vitro and in heart of spontaneously hypertensive rats (SHR in vivo. Moreover, SalA treatment in SHR resulted in decreased heart fibrosis and attenuated heart hypertrophy. These results indicated that SalA is a novel inhibitor of MMP-9, thus playing an inhibitory role in hypertensive fibrosis. Further studies to develop SalA and its analogues for their potential clinical application of cardioprotection are warranted.
Deng, Yanping; Teng, Fukang; Chen, Jing; Xue, Song; Kong, Xiangqian; Luo, Cheng; Shen, Xu; Jiang, Hualiang; Xu, Feng; Yang, Wengang; Yin, Jun; Wang, Yanhui; Chen, Hui; Wu, Wanying; Liu, Xuan; Guo, De-an
2013-01-01
Cardiac fibrosis is a deleterious consequence of hypertension which may further advance to heart failure and increased matrix metalloproteinase-9 (MMP-9) contributes to the underlying mechanism. Therefore, new therapeutic strategies to attenuate the effects of MMP-9 are urgently needed. In the present study, we characterize salvianolic acid A (SalA) as a novel MMP-9 inhibitor at molecular, cellular and animal level. We expressed a truncated form of MMP-9 which contains only the catalytic domain (MMP-9 CD), and used this active protein for enzymatic kinetic analysis and Biacore detection. Data generated from these assays indicated that SalA functioned as the strongest competitive inhibitor of MMP-9 among 7 phenolic acids from Salvia miltiorrhiza. In neonatal cardiac fibroblast, SalA inhibited fibroblast migration, blocked myofibroblast transformation, inhibited secretion of intercellular adhesion molecule (ICAM), interleukin-6 (IL-6) and soluble vascular cell adhesion molecule-1 (sVCAM-1) as well as collagen induced by MMP-9 CD. Functional effects of SalA inhibition on MMP-9 was further confirmed in cultured cardiac H9c2 cell overexpressing MMP-9 in vitro and in heart of spontaneously hypertensive rats (SHR) in vivo. Moreover, SalA treatment in SHR resulted in decreased heart fibrosis and attenuated heart hypertrophy. These results indicated that SalA is a novel inhibitor of MMP-9, thus playing an inhibitory role in hypertensive fibrosis. Further studies to develop SalA and its analogues for their potential clinical application of cardioprotection are warranted. PMID:23533637
Saha, Krishnendu; Straus, Kenneth J; Chen, Yu; Glick, Stephen J
2014-08-28
To maximize sensitivity, it is desirable that ring Positron Emission Tomography (PET) systems dedicated for imaging the breast have a small bore. Unfortunately, due to parallax error this causes substantial degradation in spatial resolution for objects near the periphery of the breast. In this work, a framework for computing and incorporating an accurate system matrix into iterative reconstruction is presented in an effort to reduce spatial resolution degradation towards the periphery of the breast. The GATE Monte Carlo Simulation software was utilized to accurately model the system matrix for a breast PET system. A strategy for increasing the count statistics in the system matrix computation and for reducing the system element storage space was used by calculating only a subset of matrix elements and then estimating the rest of the elements by using the geometric symmetry of the cylindrical scanner. To implement this strategy, polar voxel basis functions were used to represent the object, resulting in a block-circulant system matrix. Simulation studies using a breast PET scanner model with ring geometry demonstrated improved contrast at 45% reduced noise level and 1.5 to 3 times resolution performance improvement when compared to MLEM reconstruction using a simple line-integral model. The GATE based system matrix reconstruction technique promises to improve resolution and noise performance and reduce image distortion at FOV periphery compared to line-integral based system matrix reconstruction.
Energy Technology Data Exchange (ETDEWEB)
Saha, Krishnendu [Ohio Medical Physics Consulting, Dublin, Ohio 43017 (United States); Straus, Kenneth J.; Glick, Stephen J. [Department of Radiology, University of Massachusetts Medical School, Worcester, Massachusetts 01655 (United States); Chen, Yu. [Department of Radiation Oncology, Columbia University, New York, New York 10032 (United States)
2014-08-28
To maximize sensitivity, it is desirable that ring Positron Emission Tomography (PET) systems dedicated for imaging the breast have a small bore. Unfortunately, due to parallax error this causes substantial degradation in spatial resolution for objects near the periphery of the breast. In this work, a framework for computing and incorporating an accurate system matrix into iterative reconstruction is presented in an effort to reduce spatial resolution degradation towards the periphery of the breast. The GATE Monte Carlo Simulation software was utilized to accurately model the system matrix for a breast PET system. A strategy for increasing the count statistics in the system matrix computation and for reducing the system element storage space was used by calculating only a subset of matrix elements and then estimating the rest of the elements by using the geometric symmetry of the cylindrical scanner. To implement this strategy, polar voxel basis functions were used to represent the object, resulting in a block-circulant system matrix. Simulation studies using a breast PET scanner model with ring geometry demonstrated improved contrast at 45% reduced noise level and 1.5 to 3 times resolution performance improvement when compared to MLEM reconstruction using a simple line-integral model. The GATE based system matrix reconstruction technique promises to improve resolution and noise performance and reduce image distortion at FOV periphery compared to line-integral based system matrix reconstruction.
Initial guidance on digraph-matrix analysis for systems interaction studies. [PWR; BWR
Energy Technology Data Exchange (ETDEWEB)
Alesso, H.P.; Sacks, I.J.; Smith, C.F.
1983-03-01
This report describes the digraph-matrix analysis for systems structural analysis. The method is useful to analysts that are searching for both single failures and paired failures that disable systems. The digraph-matrix analysis can assure the analyst that the independent functioning of a safety system is not jeopardized by design features that cause faults to be dependent. The digraph-matrix analysis facilitates the discovery and the quantification of component reachability. The guidance is sufficiently specific that the reader can make direct application. Because a systems interaction analysis of an LWR is expensive, the resource efficiency of a candidate method is important to the staff. A demonstration of the digraph-matrix analysis is part of the staffs efforts to provide a measure of its resource efficiency. Additionally, there are features within the digraph-matrix analysis itself that might be modified to enhance resource efficiency.
Effects of spray-drying on w/o/w multiple emulsions prepared from a stearic acid matrix
Directory of Open Access Journals (Sweden)
Mlalila N
2014-12-01
Full Text Available Nichrous Mlalila,1 Hulda Swai,2 Lonji Kalombo,2 Askwar Hilonga3 1School of Life Sciences and Bioengineering, Nelson Mandela African Institution of Science and Technology, Arusha, Tanzania; 2Materials Science and Manufacturing, Council for Scientific and Industrial Research, Pretoria, South Africa; 3Department of Materials Science and Engineering, Nelson Mandela African Institution of Science and Technology, Arusha, Tanzania Abstract: The goal of this study was to explore the effects of spray-drying on w/o/w double emulsions of methyltestosterone (MT loaded in a stearic acid matrix. MT-loaded nanoparticles were formulated by a water-in-oil-in-water emulsion technique using 50, 75, and 100 mg of stearic acid, 2% and 3% w/v polyvinyl alcohol, 5% w/v lactose, and 0.2% w/v chitosan. The emulsions were immediately spray-dried based on an optimized model of inlet temperature and pump rate, and characterized for optimized responses with regard to particle size, polydispersity index, and zeta potential, for both emulsion and powder samples. Dynamic light scattering analysis shown that the nanoparticles increased in size with increasing concentrations of polyvinyl alcohol and stearic acid. Scanning electron microscopy indicated that the MT-loaded nanoparticles were spherical in shape, had a smooth surface, and were in an amorphous state, which was confirmed by differential scanning calorimetry. These MT-loaded nanoparticles are a promising candidate carrier for the delivery of MT; however, further studies are needed in order to establish the stability of the system and the cargo release profile under normal conditions of use. Keywords: double emulsions, nanoparticles, pump rate, spray-drying, testosterone
Hydrophobic silica nanoparticles as reinforcing filler for poly (lactic acid polymer matrix
Directory of Open Access Journals (Sweden)
Pilić Branka M.
2016-01-01
Full Text Available Properties of poly (lactic acid (PLA and its nanocomposites, with silica nanoparticles (SiO2, as filler were investigated. Neat PLA films and PLA films with different percentage of hydrophobic fumed silica nanoparticles (0.2, 0.5, 1, 2, 3 and 5 wt. % were prepared by solution casting method. Several tools were used to characterize the influence of different silica content on crystalline behavior, and thermal, mechanical and barrier properties of PLA/SiO2 nanocomposites. Results from scanning electron microscope (SEM showed that the nanocomposite preparation and selection of specific hydrophobic spherical nano filler provide a good dispersion of the silica nanoparticles in the PLA matrix. Addition of silica nanoparticles improved mechanical properties, the most significant improvement being observed for lowest silica content (0.2wt.%. Barrier properties were improved for all measured gases at all loadings of silica nanoparticles. The degree of crystallinity for PLA slightly increased by adding 0.2 and 0.5 wt. % of nano filler. [Projekat Ministarstva nauke Republike Srbije, br. III46001
Institute of Scientific and Technical Information of China (English)
Jin Man Kim; Sang Wook Kang; Su-Mi Shin; Duck Su Kim; Kyong-Kyu Choi; Eun-Cheol Kim; Sun-Young Kim
2014-01-01
All-trans retinoic acid (ATRA) inhibits matrix metalloproteinase (MMP)-2 and MMP-9 in synovial fibroblasts, skin fibroblasts, bronchoalveolar lavage cells and cancer cells, but activates MMP-9 in neuroblast and leukemia cells. Very little is known regarding whether ATRA can activate or inhibit MMPs in human dental pulp cells (HDPCs). The purpose of this study was to determine the effects of ATRA on the production and secretion of MMP-2 and-9 in HDPCs. The productions and messenger RNA (mRNA) expressions of MMP-2 and-9 were accessed by gelatin zymography and real-time polymerase chain reaction (PCR), respectively. ATRA was found to decrease MMP-2 level in a dose-dependent manner. Significant reduction in MMP-2 mRNA expression was also observed in HDPCs treated with 25 mmol?L21 ATRA. However, HDPCs treated with ATRA had no effect on the pattern of MMP-9 produced or secreted in either cell extracts or conditioned medium fractions. Taken together, ATRA had an inhibitory effect on MMP-2 expression in HDPCs, which suggests that ATRA could be a candidate as a medicament which could control the inflammation of pulp tissue in vital pulp therapy and regenerative endodontics.
Study of acid solution bonding in epoxy matrix for sealed radioactive sources production
Energy Technology Data Exchange (ETDEWEB)
Benega, Marcos A.G.; Nagatomi, Helio R.; Rostelato, Maria Elisa C.M.; Tiezzi, Rodrigo; Rodrigues, Bruna T.; Peleias Junior, Fernando; Souza, Carla D.; Souza, Daiane C.C. de; Souza, Anderson S. de; Silva, Thais H. da, E-mail: carladdsouza@yahoo.com.br, E-mail: marcosagbenega@gmail.com, E-mail: hrnagato@ipen.br, E-mail: elisaros@ipen.br, E-mail: rktiezzi@gmail.com, E-mail: bteigarodrigues@gmail.com, E-mail: fernandopeleias@gmail.com, E-mail: dcsouza@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)
2014-07-01
The present work aims to analyze different resin formulations. These formulations are used in the production of radioactive sealed sources that are used in many fields such as nuclear medicine; environmental analyzes, radiation detectors accuracy check, and so on. These sources can be produced with different radioisotopes and different activities, it all depending on the use they will have. Certain types of resins have the same density water. This property is appreciated when we consider that radiotracers used in nuclear medicine are applied in aqueous solutions. So the sources used for checking and calibrating equipment must have their radioisotopes sealed in a material having similar properties, thus the measures are reproducible and repetitive. The most important aspect that is brought to attention in this work is the miscibility those resins have with water. The radioisotopes for the production of the sources are supplied in an aqueous form. In case the resin and the radioisotope solution do not mix, the source will not be sturdy enough to seal the radioisotopes in its structure and the source will not be safe. There were prepared different formulations with different amounts of acid solution, and the cured formulations were analyzed by Wipe Test, DSC (Differential Splanatory Calorimetry) and also, the possible volatile aspect of the radionuclide used. All to evaluate the integrity of the sources. The obtained results were satisfactory and show that when the resin is well cured, the radioisotope remains sealed in the matrix, making it possible to produce radioactive sealed sources. (author)
Matrix effect on serum uric acid determination%血清尿酸测定的基质效应
Institute of Scientific and Technical Information of China (English)
张江涛; 王冬环; 张传宝; 曾洁; 马嵘; 赵海舰; 周伟燕; 张天娇; 闫颖; 胡翠华; 汪静
2016-01-01
Objective To evaluate the matrix effect of 21 samples (sera and processed materials) on 13 routine determination systems in serum uric acid determination. Methods Determinations were performed according to the health industry standard WS/T356-2011. Isotope dilution liquid chromatography tandem mass spectrometry (ID-LC/MS/MS)was used as comparison method,and 13 kinds of uric acid kits(enzymic assay) were chosen as evaluation method with HITACHI 7180 analyzer. The 21 samples included 4 calibrators,5 kinds of external quality assessment(EQA) samples,6 kinds of quality control materials,3 processed materials (1 kind of spine serum and 2 kinds of liquid solutions),1 kind of standard reference material(SRM) 909c from the National Institute of Standards and Technology (NIST)and 2 kinds of the External Quality Assessment Scheme for Reference Laboratories in Laboratory Medicine (RELA)samples from the International Federation of Clinical Chemistry and Laboratory Medicine(IFCC). A total of 40 fresh frozen sera and the 21 samples were analyzed by comparison method and evaluation method. The results obtained by the 2 methods were analyzed by linear regression analysis. Two-tailed 95% confidence intervals for Y predictive value were computed,and the matrix effect of sera and processed materials was evaluated. Results A total of 5 kinds of evaluation samples (2 EQA samples,1 SRM 909c and 2 RELA samples)from fresh or lyophilized sera showed no matrix effect in all routine methods. Two calibrators (Landau and Dirui) showed matrix effect in 1 routine method. Of 5 EQA samples,except for fresh sera used for trueness verification,other lyophilized sera showed matrix effect in most routine methods. The 4 of 6 quality control materials showed no matrix effect,and 2 quality control materials with high values showed negative matrix effect. Conclusions Fresh serum is a reliable sample and could be used in SRM and quality control material preparation and EQA. Some calibrators could
Structure of isothiocyanic acid dimers. Theoretical and FTIR matrix isolation studies
Krupa, Justyna; Wierzejewska, Maria
2016-05-01
A quantum mechanical study of the potential energy surface for the HNCS dimer is reported. The calculations were performed using DFT and ab initio MP2 methods. The most stable is a cyclic form with a double N-H⋯S interaction and the interaction energy in the range of 16.91-18.92 kJ mol-1. An open HNCS dimer bound by the N-H⋯N hydrogen bond is by ca 3.3-5.1 kJ mol-1 less stable. Experimental FTIR matrix isolation studies of HNCS/N2 system show that exclusively less stable open dimer is formed in solid nitrogen. Possible reasons for the observed discrepancy between theory and experiment are discussed.
We previously reported the apparent formation of matrix adducts of 3,5-dimethoxy-4-hydroxy-cinnamic acid (sinapinic acid or SA) via covalent attachment to disulfide bond-containing proteins (HdeA, HdeB and YbgS) from bacterial cell lysates ionized by matrix-assisted laser desorption/ionization (MALD...
Spectroscopy of a Gamma Irradiated Poly(Acrylic Acid)-Clotrimazole System
Institute of Scientific and Technical Information of China (English)
M.Todica; C.V.Pop; Luciana Udrescu; Traian Stefan
2011-01-01
A poly(acrylic acid)-clotrimazole system,gamma irradiated at different doses,is investigated by Raman spectroscopy.Modifications of the spectrum of the polymeric matrix appear for doses of radiation greater than 333 Gy,whereas the spectrum of clotrimazole remains unaffected at these doses of radiation.These changes correlate with modification of the vibration modes of COOH and CH2 groups of a polymeric matrix after irradiation.%A poly(acrylic acid)-clotrimazole system, gamma irradiated at different doses, is investigated by Raman spec-troscopy. Modifications of the spectrum of the polymeric matrix appear for doses of radiation greater than 333 Gy, whereas the spectrum of clotrimazole remains unaffected at these doses of radiation. These changes correlate with modification of the vibration modes of COOH and CH2 groups of a polymeric matrix after irradiation.
Jiang, Zhaolin; Shen, Nuo; Zhou, Jianwei
2013-01-01
We first give the style spectral decomposition of a special skew circulant matrix C and then get the style decomposition of arbitrary skew circulant matrix by making use of the Kronecker products between the elements of first row in skew circulant and the special skew circulant C. Besides that, we obtain the singular value of skew circulant matrix as well. Finally, we deal with the optimal backward perturbation analysis for the linear system with skew circulant coefficient matrix on the base of its style spectral decomposition. PMID:24369488
The proteolytic system of lactic acid bacteria.
Mayo, B
1993-12-01
Lactic acid bacteria are widely used throughout the world, empirically or deliberately, in the manufacturing of several food and feed stuffs, including milk products (such as cheese, butter, yoghurt, buttermilk, etc.), fermented vegetables (pickles, olives and sauerkraut), sausages, sourdough bread and silage, due to their ability to convert sugars into lactic acid. Of these, dairy products are of outstanding economic importance. Starter cultures used in the dairy industry are mixtures of carefully selected lactic acid bacteria which are added to the milk to fulfil the desired fermentation. Dairy starter cultures must reach high densities in milk in order to produce lactic acid at the required rates for manufacturing. Under these conditions, amino acids supply becomes limitant due to their scarce concentration in milk and to the auxotrophies shown by many starter bacteria. This implies the necessity of a proteolytic system, able to degrade the most abundant protein in milk, casein, into assimilable amino acids and peptides. Casein degradation and utilization require the concerted action of proteinases, peptidases and amino acid and peptide uptake systems. This whole set of enzymes constitutes the proteolytic system. In this article an overview of the recent biochemical and genetic data on the proteolytic system of lactic acid bacteria will be presented.
Inoue, Motoki; Sasaki, Makoto; Katada, Yasuyuki; Taguchi, Tetsushi
2014-02-01
Novel techniques for creating a strong bond between polymeric matrices and biometals are required. We immobilized polymeric matrices on the surface of biometal for drug-eluting stents through covalent bond. We performed to improve the bonding strength between a cobalt-chromium alloy and a citric acid-crosslinked gelatin matrix by ultraviolet irradiation on the surface of cobalt-chromium alloy. The ultraviolet irradiation effectively generated hydroxyl groups on the surface of the alloy. The bonding strength between the gelatin matrix and the alloy before ultraviolet irradiation was 0.38 ± 0.02 MPa, whereas it increased to 0.48 ± 0.02 MPa after ultraviolet irradiation. Surface analysis showed that the citric acid derivatives occurred on the surface of the cobalt-chromium alloy through ester bond. Therefore, ester bond formation between the citric acid derivatives active esters and the hydroxyl groups on the cobalt-chromium alloy contributed to the enhanced bonding strength. Ultraviolet irradiation and subsequent immobilization of a gelatin matrix using citric acid derivatives is thus an effective way to functionalize biometal surfaces.
Directory of Open Access Journals (Sweden)
Soldatova S.
2015-12-01
Full Text Available This article addresses the task of creating a regional Social Accounting Matrix (SAM in the Kaliningrad region. Analyzing the behavior of economic systems of national and sub-national levels in the changing environment is one of the main objectives of macroeconomic research. Matrices are used in examining the flow of financial resources, which makes it possible to conduct a comprehensive analysis of commodity and cash flows at the regional level. The study identifies key data sources for matrix development and presents its main results: the data sources for the accounts development and filling the social accounting matrix are identified, regional accounts consolidated, the structure of regional matrix devised, and the multiplier of the regional social accounting matrix calculated. An important aspect of this approach is the set target, which determines the composition of matrix accounts representing different aspects of regional performance. The calculated multiplier suggests the possibility of modelling of a socioeconomic system for the region using a social accounting matrix. The regional modelling approach ensures the matrix compliance with the methodological requirements of the national system.
Directory of Open Access Journals (Sweden)
Soldatova S.
2015-08-01
Full Text Available This article addresses the task of creating a regional Social Accounting Matrix (SAM in the Kaliningrad region. Analyzing the behavior of economic systems of national and sub-national levels in the changing environment is one of the main objectives of macroeconomic research. Matrices are used in examining the flow of financial resources, which makes it possible to conduct a comprehensive analysis of commodity and cash flows at the regional level. The study identifies key data sources for matrix development and presents its main results: the data sources for the accounts development and filling the social accounting matrix are identified, regional accounts consolidated, the structure of regional matrix devised, and the multiplier of the regional social accounting matrix calculated. An important aspect of this approach is the set target, which determines the composition of matrix accounts representing different aspects of regional performance. The calculated multiplier suggests the possibility of modelling of a socioeconomic system for the region using a social accounting matrix. The regional modelling approach ensures the matrix compliance with the methodological requirements of the national system
Directory of Open Access Journals (Sweden)
Soldatova Svetlana
2015-09-01
Full Text Available This article addresses the task of creating a regional Social Accounting Matrix (SAM in the Kaliningrad region. Analyzing the behavior of economic systems of national and sub-national levels in the changing environment is one of the main objectives of macroeconomic research. Matrices are used in examining the flow of financial resources, which makes it possible to conduct a comprehensive analysis of commodity and cash flows at the regional level. The study identifies key data sources for matrix development and presents its main results: the data sources for the accounts development and filling the social accounting matrix are identified, regional accounts consolidated, the structure of regional matrix devised, and the multiplier of the regional social accounting matrix calculated. An important aspect of this approach is the set target, which determines the composition of matrix accounts representing different aspects of regional performance. The calculated multiplier suggests the possibility of modelling of a socioeconomic system for the region using a social accounting matrix. The regional modelling approach ensures the matrix compliance with the methodological requirements of the national system
Integrative systems and synthetic biology of cell-matrix adhesion sites.
Zamir, Eli
2016-09-02
The complexity of cell-matrix adhesion convolves its roles in the development and functioning of multicellular organisms and their evolutionary tinkering. Cell-matrix adhesion is mediated by sites along the plasma membrane that anchor the actin cytoskeleton to the matrix via a large number of proteins, collectively called the integrin adhesome. Fundamental challenges for understanding how cell-matrix adhesion sites assemble and function arise from their multi-functionality, rapid dynamics, large number of components and molecular diversity. Systems biology faces these challenges in its strive to understand how the integrin adhesome gives rise to functional adhesion sites. Synthetic biology enables engineering intracellular modules and circuits with properties of interest. In this review I discuss some of the fundamental questions in systems biology of cell-matrix adhesion and how synthetic biology can help addressing them.
Energy Technology Data Exchange (ETDEWEB)
Cai Ning; Gong Yingxue; Chan, Vincent; Liao Kin [School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore 639798 (Singapore); Chian, Kerm Sin [School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore 639798 (Singapore)], E-mail: askliao@ntu.edu.sg
2008-03-01
Effective attachment of esophageal cells on biomaterials is one important requirement in designing engineered esophagus substitute for esophageal cancer treatment. In this study, poly(lactic acid) (PLA) was subjected to surface modification by coupling extracellular matrix (ECM) proteins on its surface to promote cell adhesion. Two typical ECM proteins, collagen type I (COL) and fibronectin (FN), were immobilized on the PLA surface with the aid of glutaraldehyde as a cross linker between aminolyzed PLA and ECM proteins. By using confocal reflectance interference contrast microscopy (C-RICM) integrating with phase contrast microscopy, the long-term adhesion dynamics of porcine esophageal fibroblasts (PEFs) on four types of surfaces (unmodified PLA, PLA-COOH, PLA-COL and PLA-FN) was investigated during 24 h of culture. It is demonstrated by C-RICM results that PEFs form strong adhesion contact on all four types of surfaces at different stages of cell seeding. Among the four surfaces, PEFs on the PLA-FN surface reach the maximum adhesion energy (9.5 x 10{sup -7} J m{sup -2}) in the shortest time (20 min) during the initial stage of cell seeding. After adhesion energy reaches the maximum value, PEFs maintain their highly deformed geometries till they reached a steady state after 20 h of culture. F-actin immunostaining results show that the evolvement of spatial organization of F-actin is tightly correlated with the formation of adhesion contact and cell spreading. Furthermore, the cell attachment ratio of PEFs on PLA in 2 h is only 26% compared with 88% on PLA-FN, 73% on PLA-COL and 36% on PLA-COOH. All the results demonstrate the effect of surface functionalization on the biophysical responses of PEFs in cell adhesion. Fibronectin-immobilized PLA demonstrates promising potential for application as an engineered esophagus substitute.
21 CFR 862.1450 - Lactic acid test system.
2010-04-01
... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Lactic acid test system. 862.1450 Section 862.1450....1450 Lactic acid test system. (a) Identification. A lactic acid test system is a device intended to measure lactic acid in whole blood and plasma. Lactic acid measurements that evaluate the acid-base...
Automated MALDI Matrix Coating System for Multiple Tissue Samples for Imaging Mass Spectrometry
Mounfield, William P.; Garrett, Timothy J.
2012-03-01
Uniform matrix deposition on tissue samples for matrix-assisted laser desorption/ionization (MALDI) is key for reproducible analyte ion signals. Current methods often result in nonhomogenous matrix deposition, and take time and effort to produce acceptable ion signals. Here we describe a fully-automated method for matrix deposition using an enclosed spray chamber and spray nozzle for matrix solution delivery. A commercial air-atomizing spray nozzle was modified and combined with solenoid controlled valves and a Programmable Logic Controller (PLC) to control and deliver the matrix solution. A spray chamber was employed to contain the nozzle, sample, and atomized matrix solution stream, and to prevent any interference from outside conditions as well as allow complete control of the sample environment. A gravity cup was filled with MALDI matrix solutions, including DHB in chloroform/methanol (50:50) at concentrations up to 60 mg/mL. Various samples (including rat brain tissue sections) were prepared using two deposition methods (spray chamber, inkjet). A linear ion trap equipped with an intermediate-pressure MALDI source was used for analyses. Optical microscopic examination showed a uniform coating of matrix crystals across the sample. Overall, the mass spectral images gathered from tissues coated using the spray chamber system were of better quality and more reproducible than from tissue specimens prepared by the inkjet deposition method.
Xu, Suxin; Chen, Jiangang; Wang, Bijia; Yang, Yiqi
2015-11-15
Two predictive models were presented for the adsorption affinities and diffusion coefficients of disperse dyes in polylactic acid matrix. Quantitative structure-sorption behavior relationship would not only provide insights into sorption process, but also enable rational engineering for desired properties. The thermodynamic and kinetic parameters for three disperse dyes were measured. The predictive model for adsorption affinity was based on two linear relationships derived by interpreting the experimental measurements with molecular structural parameters and compensation effect: ΔH° vs. dye size and ΔS° vs. ΔH°. Similarly, the predictive model for diffusion coefficient was based on two derived linear relationships: activation energy of diffusion vs. dye size and logarithm of pre-exponential factor vs. activation energy of diffusion. The only required parameters for both models are temperature and solvent accessible surface area of the dye molecule. These two predictive models were validated by testing the adsorption and diffusion properties of new disperse dyes. The models offer fairly good predictive ability. The linkage between structural parameter of disperse dyes and sorption behaviors might be generalized and extended to other similar polymer-penetrant systems.
Pan, Cong; Fang, Dong; Xu, Guangrui; Liang, Jian; Zhang, Guiyou; Wang, Hongzhong; Xie, Liping; Zhang, Rongqing
2014-01-31
Magnesium is widely used to control calcium carbonate deposition in the shell of pearl oysters. Matrix proteins in the shell are responsible for nucleation and growth of calcium carbonate crystals. However, there is no direct evidence supporting a connection between matrix proteins and magnesium. Here, we identified a novel acidic matrix protein named PfN44 that affected aragonite formation in the shell of the pearl oyster Pinctada fucata. Using immunogold labeling assays, we found PfN44 in both the nacreous and prismatic layers. In shell repair, PfN44 was repressed, whereas other matrix proteins were up-regulated. Disturbing the function of PfN44 by RNAi led to the deposition of porous nacreous tablets with overgrowth of crystals in the nacreous layer. By in vitro circular dichroism spectra and fluorescence quenching, we found that PfN44 bound to both calcium and magnesium with a stronger affinity for magnesium. During in vitro calcium carbonate crystallization and calcification of amorphous calcium carbonate, PfN44 regulated the magnesium content of crystalline carbonate polymorphs and stabilized magnesium calcite to inhibit aragonite deposition. Taken together, our results suggested that by stabilizing magnesium calcite to inhibit aragonite deposition, PfN44 participated in P. fucata shell formation. These observations extend our understanding of the connections between matrix proteins and magnesium.
Energy Technology Data Exchange (ETDEWEB)
Ramasamy, Mohankandhasamy [Division of Bionanotechnology, Gachon University, Seongnam 461-701 (Korea, Republic of); Kim, Yu Jun; Gao, Haiyan [Department of Polymer Engineering, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Yi, Dong Kee, E-mail: vitalis@mju.ac.kr [Department of Chemistry, Myongji University, Yongin 449-728 (Korea, Republic of); An, Jeong Ho, E-mail: jhahn1us@skku.edu [Department of Polymer Engineering, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of)
2014-03-01
Graphical abstract: - Highlights: • Well layer thickness controlled silica shell was made on ZnO nanoparticles. • PEAA, an interfacial agent is used to make nanocomposite–polymer matrix by twin-screw extruder. • Si-ZnO/PEAA matrix is highly stable and UV protective as compared to ZnO/PEAA matrix. • Nanoparticle embedded polymer matrix is suggested to make UV shielding fabrics with Nylon4. - Abstract: Silica coated zinc oxide nanoparticles (Si-ZnO NPs) (7 nm thick) were synthesized successfully and melt blended with poly(ethylene-co-acrylic acid) (PEAA resin) to improving ultraviolet (UV) shielding of zinc oxide nanoparticles (ZnO NPs). The photostability of both the ZnO NPs and Si-ZnO NPs were analyzed by the difference in photoluminescence (PL) and by methylene blue (MB) degradation. Photo-degradation studies confirmed that Si-ZnO NPs are highly photostable compared to ZnO NPs. The melt blended matrices were characterized by field emission scanning electron microscopy interfaced with energy dispersive X-ray spectroscopy (FE-SEM-EDX). The UV shielding property was analyzed from the transmittance spectra of UV–visible (UV–vis) spectroscopy. The results confirmed fine dispersion of thick Si-ZnO NPs in the entire resin matrix. Moreover, the Si-ZnO/PEAA showed about 97% UV shielding properties than the ZnO/PEAA.
A Mathematical Model for Diffusion-Controlled Monolithic Matrix Coated with outer Membrane System
Institute of Scientific and Technical Information of China (English)
无
2001-01-01
A release model for diffusion-controlled monolithic matrix coated with outer membrane system is proposed and solved by using the refined double integral method. The calculated results are in satisfactory agreement with the experimental release data. The present model can be well used to describe the release process for all cd/cs values. In addition, the release effects of the monolithic matrix coated with outer membrane system are discussed theoretically.
New Neumann System Associated with a 3 × 3 Matrix Spectral Problem
Directory of Open Access Journals (Sweden)
Fang Li
2014-01-01
Full Text Available The nonlinearization approach of Lax pair is applied to the case of the Neumann constraint associated with a 3 × 3 matrix spectral problem, from which a new Neumann system is deduced and proved to be completely integrable in the Liouville sense. As an application, solutions of the first nontrivial equation related to the 3 × 3 matrix spectral problem are decomposed into solving two compatible Hamiltonian systems of ordinary differential equations.
Development and Clinical Evaluation of MatrixMANDIBLE Subcondylar Plates System (Synthes)
Cortelazzi, Roberto; Altacera, Mario; Turco, Monica; Antonicelli, Viviana; De Benedittis, Michele
2014-01-01
In this article, authors report the different steps of development and clinical validation of MatrixMANDIBLE Subcondylar Plates (Synthes, Soletta, Switzerland), a specialized osteosynthesis system developed by Synthes during the past 4 years. Between 2009 and 2013, a total of 62 patients were treated for subcondylar and condylar neck fractures via a preauricular or retromandibular/transparotid approach. The MatrixMANDIBLE Subcondylar Plates System consists of a Trapezoidal Plate, a three-dime...
ANALYSIS OF TWO-MACHINE CONWIP SYSTEM:MATRIX GEOMETRIC SOLUTION
Institute of Scientific and Technical Information of China (English)
LIU Bin; YUE Dequan; CAO Jinhua; WANG Huanqiu
2000-01-01
In this paper we consider a two-machine CONWIP system. Firstly, we mathematically model the system as a QBD process. By using the matrix geometric solution technique, we obtain the equilibrium conditions of the system. Next, we derive the stationary probability distribution of the process. Finally, we give some important performance measures of the system.
Linear matrix inequalities for analysis and control of linear vector second-order systems
Energy Technology Data Exchange (ETDEWEB)
Adegas, Fabiano D. [Aalborg Univ. (Denmark); Stoustrup, Jakob [Aalborg Univ. (Denmark)
2014-10-06
Many dynamical systems are modeled as vector second-order differential equations. This paper presents analysis and synthesis conditions in terms of LMI with explicit dependence in the coefficient matrices of vector second-order systems. These conditions benefit from the separation between the Lyapunov matrix and the system matrices by introducing matrix multipliers, which potentially reduce conservativeness in hard control problems. Multipliers facilitate the usage of parameter-dependent Lyapunov functions as certificates of stability of uncertain and time-varying vector second-order systems. The conditions introduced in this work have the potential to increase the practice of analyzing and controlling systems directly in vector second-order form.
Measurement system for resistive metal oxide sensors matrix
Róg, Piotr; Rydosz, Artur; Brudnik, Andrzej
2016-12-01
The measurement system for laboratory array of gas sensors was constructed. The system can be used to measure the response characteristic of resistive metal oxide (MOx) gas sensors. Proposed system is flexible and reconfigurable easy, to perform high and low resistivity measurements.
Trčka, Nikola
2009-01-01
We first study labeled transition systems with explicit successful termination. We establish the notions of strong, weak, and branching bisimulation in terms of boolean matrix theory, introducing thus a novel and powerful algebraic apparatus. Next we consider Markov reward chains which are standardly presented in real matrix theory. By interpreting the obtained matrix conditions for bisimulations in this setting, we automatically obtain the definitions of strong, weak, and branching bisimulation for Markov reward chains. The obtained strong and weak bisimulations are shown to coincide with some existing notions, while the obtained branching bisimulation is new, but its usefulness is questionable.
Energy-dependent correlations in the S-matrix of chaotic systems
Novaes, Marcel
2016-12-01
The M-dimensional unitary matrix S(E), which describes scattering of waves, is a strongly fluctuating function of the energy for complex systems such as ballistic cavities, whose geometry induces chaotic ray dynamics. Its statistical behaviour can be expressed by means of correlation functions of the kind , which have been much studied within the random matrix approach. In this work, we consider correlations involving an arbitrary number of matrix elements and express them as infinite series in 1/M, whose coefficients are rational functions of ɛ. From a mathematical point of view, this may be seen as a generalization of the Weingarten functions of circular ensembles.
Directory of Open Access Journals (Sweden)
Nikola Trčka
2009-12-01
Full Text Available We first study labeled transition systems with explicit successful termination. We establish the notions of strong, weak, and branching bisimulation in terms of boolean matrix theory, introducing thus a novel and powerful algebraic apparatus. Next we consider Markov reward chains which are standardly presented in real matrix theory. By interpreting the obtained matrix conditions for bisimulations in this setting, we automatically obtain the definitions of strong, weak, and branching bisimulation for Markov reward chains. The obtained strong and weak bisimulations are shown to coincide with some existing notions, while the obtained branching bisimulation is new, but its usefulness is questionable.
Lyapunov Functions and Solutions of the Lyapunov Matrix Equation for Marginally Stable Systems
DEFF Research Database (Denmark)
Kliem, Wolfhard; Pommer, Christian
2000-01-01
of the Lyapunov matrix equation and characterize the set of matrices $(B, C)$ which guarantees marginal stability. The theory is applied to gyroscopic systems, to indefinite damped systems, and to circulatory systems, showing how to choose certain parameter matrices to get sufficient conditions for marginal...
The noncommutative Choquet boundary III: Operator systems in matrix algebras
Arveson, William
2008-01-01
We classify operator systems $S\\subseteq \\mathcal B(H)$ that act on finite dimensional Hilbert spaces by making use of the noncommutative Choquet boundary. S is said to be {\\em reduced} when its boundary ideal is 0. In the category of operator systems, that property functions as semisimplicity does in the category of complex Banach algebras. We construct explicit examples of reduced operator systems using sequences of "parameterizing maps" $\\Gamma_k: \\mathbb C^r\\to \\mathcal B(H_k)$, $k=1,..., N$. We show that every reduced operator system is isomorphic to one of these, and that two sequences give rise to isomorphic operator systems if and only if they are "unitarily equivalent" parameterizing sequences. Finally, we construct nonreduced operator systems $S$ that have a given boundary ideal $K$ and a given reduced image in $C^*(S)/K$, and show that these constructed examples exhaust the possibilities.
Indian Academy of Sciences (India)
PUJARINI BANERJEE; INDRANI BHATTACHARYA; TAPAS CHAKRABORTY
2016-10-01
Mid infrared spectra of two O–H· · · π hydrogen-bonded binary complexes of acetic acid (AA) and trifluoroacetic acid (F₃AA) with benzene (Bz) have been measured by isolating the complexes in an argon matrix at ∼8 K. In a matrix isolation condition, the O–H stretching fundamentals (νO−H) of the carboxylic acid groups of the two molecules are observed to have almost the same value. However, the spectral red-shifts of νO−H bands of the two acids on complexation with Bz are largely different, 90 and 150 cm⁻¹ for AA and F₃AA, respectively. Thus, the O–H bond weakening of the two acids upon binding with Bz in a non-interacting environment follows the sequence of their ionic dissociation tendencies (pKa) in aqueous media. Furthermore, ΔνO−H of the latter complex is the largest among the known π-hydrogen bonded binary complexes of prototypical O–H donors reported so far with respect to Bz as acceptor. It is also observed that the spectral shifts (ΔνO−H) of phenol-Bz and carboxylic acid-Bz complexes show similar dependence on the acidity factor (pKa). Electronic structure theory has been used to suggest suitable geometries of the complexes that are consistent with the measured IR spectral changes. Calculation at MP2/6-311++G (d, p) level predicts a T-shaped geometry for both AA-Bz and F₃AA-Bz complexes, and the corresponding binding energies are 3.0 and 4.5 kcal/mol, respectively. Natural Bond Orbital (NBO) analysis has been performed to correlate the observed spectral behavior of the complexes with the electronic structure parameters.
Numerical solution of Sylvester matrix equations: Application to dynamical systems
Directory of Open Access Journals (Sweden)
Shukooh Sadat Asari
2016-01-01
Full Text Available Many problems of control theory specially dynamical system lead to Sylvester equations. In this paper, we employ an iterative method of optimization based on partial swarm theory to solve the Sylvester system. To this purpose we consider dynamical system with different construction of state observer which lead to Sylvester observer equation. Using Pso to optimize the solution, obtain the solution with high accuracy comparison with other numerical methods, since the stability analysis of particle dynamics of PSO associated with the best particle is based on nonlinear feedback systems. Finally, some examples demonstrate the efficiency of the proposed method.
MODELING OF DYNAMIC SYSTEMS WITH MODULATION BY MEANS OF KRONECKER VECTOR-MATRIX REPRESENTATION
Directory of Open Access Journals (Sweden)
A. S. Vasilyev
2015-09-01
Full Text Available The paper deals with modeling of dynamic systems with modulation by the possibilities of state-space method. This method, being the basis of modern control theory, is based on the possibilities of vector-matrix formalism of linear algebra and helps to solve various problems of technical control of continuous and discrete nature invariant with respect to the dimension of their “input-output” objects. Unfortunately, it turned its back on the wide group of control systems, which hardware environment modulates signals. The marked system deficiency is partially offset by this paper, which proposes Kronecker vector-matrix representations for purposes of system representation of processes with signal modulation. The main result is vector-matrix representation of processes with modulation with no formal difference from continuous systems. It has been found that abilities of these representations could be effectively used in research of systems with modulation. Obtained model representations of processes with modulation are best adapted to the state-space method. These approaches for counting eigenvalues of Kronecker matrix summaries, that are matrix basis of model representations of processes described by Kronecker vector products, give the possibility to use modal direction in research of dynamics for systems with modulation. It is shown that the use of controllability for eigenvalues of general matrixes applied to Kronecker structures enabled to divide successfully eigenvalue spectrum into directed and not directed components. Obtained findings including design problems for models of dynamic processes with modulation based on the features of Kronecker vector and matrix structures, invariant with respect to the dimension of input-output relations, are applicable in the development of alternate current servo drives.
Abdelhamid, Hani Nasser; Wu, Hui-Fen
2013-10-15
The present study introduces two novel organic matrices for matrix assisted laser desorption/ionization mass spectrometry (MALDI-MS) for the analysis of small molecules. The first matrix is "2-amino-4,5-diphenylfuran-3-carboxylic acid" (also called furoic acid, FA) which was synthesized and then characterized by ultraviolet (UV), infrared (FTIR), nuclear magnetic resonance NMR ((1)H and (13)C) and mass spectrometry. The compound has organic semiconductor properties and exhibits intense UV-absorption which is suitable for the UV-MALDI laser (N2 laser, 337 nm). The second matrix is mefenamic acid (MA). The two matrices can be successfully applied for various classes of compounds including adenosine-5'-triphosphate (ATP, 0.5 µL(10.0 nmol)), spectinomycin (spect, 0.5 µL(14.0 nmol)), glutathione (GSH, 0.5 µL(9.0 nmol)), sulfamethazole (SMT, 0.5 µL(2.0 nmol)) and mixture of peptides gramicidin D (GD, 0.5µL (9.0 nmol)). The two matrices can effectively absorb the laser energy, resulting in excellent desorption/ionization of small molecules. The new matrices offer a significant enhancement of ionization, less fragmentation, few interferences, nice reproducibility, and excellent stability under vacuum. Theoretical calculations of the physical parameters demonstrated increase in polarizability, molar volume and refractivity than the conventional organic matrices which can effectively enhance the proton transfer reactions between the matrices with the analyte molecules. While the reduction in density, surface tension and index of refraction can enhance homogeneity between the two new matrices with the analytes. Due to the sublimation energy of mefenamic acid is (1.2 times) higher than that of the DHB, it is more stable to be used in the vacuum.
Upper Triangular Matrix of Lie Algebra and a New Discrete Integrable Coupling System
Institute of Scientific and Technical Information of China (English)
YU Fa-Jun; ZHANG Hong-Qing
2007-01-01
The upper triangular matrix of Lie algebra is used to construct integrable couplings of discrete solition equations.Correspondingly,a feasible way to construct integrable couplings is presented.A nonlinear lattice soliton equation spectral problem is obtained and leads to a novel hierarchy of the nonlinear lattice equation hierarchy.It indicates that the study of integrable couplings using upper triangular matrix of Lie algebra is an important step towards constructing integrable systems.
A Unisonant r-Matrix Structure of Integrable Systems and Its Reductions
Institute of Scientific and Technical Information of China (English)
QIAO Zhi-Jun; Walter STRAMPP
2000-01-01
A new method is presented to generate finite dimensional integrable systems. Our starting point is a generalized Lax matrix instead of usual Lax pair. Then a unisonant r-matrix structure and a set of generalized Hamiltonian functions are constructed. It can be clearly seen that various constrained integrable flows by nonlinearization method, such as the c-AKNS, c-MKdV, c-Toda, etc., are derived from the reduction of this structure. Furthermore, some new integrable flows are produced
Dang, Cuong Cao; Lefort, Vincent; Le, Vinh Sy; Le, Quang Si; Gascuel, Olivier
2011-10-01
Amino acid replacement rate matrices are an essential basis of protein studies (e.g. in phylogenetics and alignment). A number of general purpose matrices have been proposed (e.g. JTT, WAG, LG) since the seminal work of Margaret Dayhoff and co-workers. However, it has been shown that matrices specific to certain protein groups (e.g. mitochondrial) or life domains (e.g. viruses) differ significantly from general average matrices, and thus perform better when applied to the data to which they are dedicated. This Web server implements the maximum-likelihood estimation procedure that was used to estimate LG, and provides a number of tools and facilities. Users upload a set of multiple protein alignments from their domain of interest and receive the resulting matrix by email, along with statistics and comparisons with other matrices. A non-parametric bootstrap is performed optionally to assess the variability of replacement rate estimates. Maximum-likelihood trees, inferred using the estimated rate matrix, are also computed optionally for each input alignment. Finely tuned procedures and up-to-date ML software (PhyML 3.0, XRATE) are combined to perform all these heavy calculations on our clusters. http://www.atgc-montpellier.fr/ReplacementMatrix/ olivier.gascuel@lirmm.fr Supplementary data are available at http://www.atgc-montpellier.fr/ReplacementMatrix/
Directory of Open Access Journals (Sweden)
Lynne Shinto
2011-01-01
Full Text Available In multiple sclerosis (MS, compromised blood-brain barrier (BBB integrity contributes to inflammatory T cell migration into the central nervous system. Matrix metalloproteinase-9 (MMP-9 is associated with BBB disruption and subsequent T cell migration into the CNS. The aim of this paper was to evaluate the effects of omega-3 fatty acids on MMP-9 levels and T cell migration. Peripheral blood mononuclear cells (PBMC from healthy controls were pretreated with two types of omega-3 fatty acids, eicosapentaenoic acid (EPA, and docosahexaenoic acid (DHA. Cell supernatants were used to determine MMP-9 protein and activity levels. Jurkat cells were pretreated with EPA and DHA and were added to fibronectin-coated transwells to measure T cell migration. EPA and DHA significantly decreased MMP-9 protein levels, MMP-9 activity, and significantly inhibited human T cell migration. The data suggest that omega-3 fatty acids may benefit patients with multiple sclerosis by modulating immune cell production of MMP-9.
Stabilization of pH in solid-matrix hydroponic systems
Frick, J.; Mitchell, C. A.
1993-01-01
2-[N-morpholino]ethanesulfonic acid (MES) buffer or Amberlite DP-1 (cation-exchange resin beads) were used to stabilize substrate pH of passive-wicking, solid-matrix hydroponic systems in which small canopies of Brassica napus L. (CrGC 5-2, genome : ACaacc) were grown to maturity. Two concentrations of MES (5 or 10 mM) were included in Hoagland 1 nutrient solution. Alternatively, resin beads were incorporated into the 2 vermiculite : 1 perlite (v/v) growth medium at 6% or 12% of total substrate volume. Both strategies stabilized pH without toxic side effects on plants. Average seed yield rates for all four pH stabilization treatments (13.3 to 16.9 g m-2 day-1) were about double that of the control (8.2 g m-2 day-1), for which there was no attempt to buffer substrate pH. Both the highest canopy seed yield rate (16.9 g m-2 day-1) and the highest shoot harvest index (19.5%) occurred with the 6% resin bead treatment, even though the 10 mM MES and 12% bead treatments maintained pH within the narrowest limits. The pH stabilization methods tested did not significantly affect seed oil and protein contents.
Institute of Scientific and Technical Information of China (English)
Weihai ZHANG; Xuezhen LIU; Shulan KONG; Qinghua LI
2006-01-01
This paper treats the feedback stabilization of nonlinear stochastic time-delay systems with state and control-dependent noise. Some locally (globally) robustly stabilizable conditions are given in terms of matrix inequalities that are independent of the delay size. When it is applied to linear stochastic time-delay systems, sufficient conditions for the state-feedback stabilization are presented via linear matrix inequalities. Several previous results are extended to more general systems with both state and control-dependent noise, and easy computation algorithms are also given.
The decoupling of second-order linear systems with a singular mass matrix
Kawano, Daniel T.; Morzfeld, Matthias; Ma, Fai
2013-12-01
It was demonstrated in earlier work that a nondefective, linear dynamical system with an invertible mass matrix in free or forced motion may be decoupled in the configuration space by a real and isospectral transformation. We extend this work by developing a procedure for decoupling a linear dynamical system with a singular mass matrix in the configuration space, transforming the original differential-algebraic system into decoupled sets of real, independent, first- and second-order differential equations. Numerical examples are provided to illustrate the application of the decoupling procedure.
Hessian matrix estimation in hybrid systems based on an embedded FFNN.
Baek, Seung-Mook; Park, Jung-Wook
2010-10-01
This paper describes the Hessian matrix estimation of nonsmooth nonlinear parameters by the identifier based on a feedforward neural network (FFNN) embedded in a hybrid system, which is modeled by the differential-algebraic-impulsive-switched (DAIS) structure. After identifying full dynamics of the hybrid system, the FFNN is used to estimate second-order derivatives of an objective function J with respect to the nonlinear parameters from the gradient information, which are trajectory sensitivities. Then, the estimated Hessian matrix is applied to the optimal tuning of a saturation limiter used in a practical engineering system.
Skew-orthogonal polynomials, differential systems and random matrix theory
Energy Technology Data Exchange (ETDEWEB)
Ghosh, Saugata [Abdus Salam ICTP, Strada Costiera 11, 34100, Trieste (Italy)
2007-01-26
We study skew-orthogonal polynomials with respect to the weight function exp [ - 2V(x)], with V(x) = {sigma}{sup 2d}{sub K=1}(u{sub K}/K)x{sup K}, u{sub 2d} > 0, d > 0. A finite subsequence of such skew-orthogonal polynomials arising in the study of orthogonal and symplectic ensembles of random matrices satisfies a system of differential-difference-deformation equation. The vectors formed by such subsequence have the rank equal to the degree of the potential in the quaternion sense. These solutions satisfy certain compatibility condition and hence admit a simultaneous fundamental system of solutions.
High Performance Control of Matrix Converter Fed Induction Motor Drive System
Institute of Scientific and Technical Information of China (English)
孙凯; 黄立培; MATSUSE Kouki
2007-01-01
Matrix converter fed motor drive is superior to pulse width modulation inverter drives since it not only provides bi-directional power flow, sinusoidal input/output currents, unity input power factor, but also allows a compact design due to the lack of DC-link capacitors for energy storage. In this paper, model and control of matrix converter fed induction motor drive system are analyzed. A combined control strategy is simplified and improved, which realizes space vector pulse width modulation of matrix converter and rotor flux oriented vector control technique for induction motor drive simultaneously. This control strategy combines the advantages of matrix converter with the good drive performance of vector control technique. Experimental results demonstrate the feasibility and effectiveness of the proposed control strategy.
Nucleic acid amplification using microfluidic systems.
Chang, Chen-Min; Chang, Wen-Hsin; Wang, Chih-Hung; Wang, Jung-Hao; Mai, John D; Lee, Gwo-Bin
2013-04-07
In the post-human-genome-project era, the development of molecular diagnostic techniques has advanced the frontiers of biomedical research. Nucleic-acid-based technology (NAT) plays an especially important role in molecular diagnosis. However, most research and clinical protocols still rely on the manual analysis of individual samples by skilled technicians which is a time-consuming and labor-intensive process. Recently, with advances in microfluidic designs, integrated micro total-analysis-systems have emerged to overcome the limitations of traditional detection assays. These microfluidic systems have the capability to rapidly perform experiments in parallel and with a high-throughput which allows a NAT analysis to be completed in a few hours or even a few minutes. These features have a significant beneficial influence on many aspects of traditional biological or biochemical research and this new technology is promising for improving molecular diagnosis. Thus, in the foreseeable future, microfluidic systems developed for molecular diagnosis using NAT will become an important tool in clinical diagnosis. One of the critical issues for NAT is nucleic acid amplification. In this review article, recent advances in nucleic acid amplification techniques using microfluidic systems will be reviewed. Different approaches for fast amplification of nucleic acids for molecular diagnosis will be highlighted.
The proteolytic systems of lactic acid bacteria
Kunji, Edmund R.S.; Mierau, Igor; Hagting, Anja; Poolman, Bert; Konings, Wil N.
1996-01-01
Proteolysis in dairy lactic acid bacteria has been studied in great detail by genetic, biochemical and ultrastructural methods. From these studies the picture emerges that the proteolytic systems of lactococci and lactobacilli are remarkably similar in their components and mode of action. The proteo
Uric Acid Nephrolithiasis: A Systemic Metabolic Disorder
Moe, Orson W.
2014-01-01
Uric acid nephrolithiasis is characteristically a manifestation of a systemic metabolic disorder. It has a prevalence of about 10% among all stone formers, the third most common type of kidney stone in the industrialized world. Uric acid stones form primarily due to an unduly acid urine; less deciding factors are hyperuricosuria and a low urine volume. The vast majority of uric acid stone formers have the metabolic syndrome, and not infrequently, clinical gout is present as well. A universal finding is a low baseline urine pH plus insufficient production of urinary ammonium buffer. Persons with gastrointestinal disorders, in particular chronic diarrhea or ostomies, and patients with malignancies with a large tumor mass and high cell turnover comprise a less common but nevertheless important subset. Pure uric acid stones are radiolucent but well visualized on renal ultrasound. A 24 h urine collection for stone risk analysis provides essential insight into the pathophysiology of stone formation and may guide therapy. Management includes a liberal fluid intake and dietary modification. Potassium citrate to alkalinize the urine to a goal pH between 6 and 6.5 is essential, as undissociated uric acid deprotonates into its much more soluble urate form. PMID:25045326
FUNDAMENTAL MATRIX OF LINEAR CONTINUOUS SYSTEM IN THE PROBLEM OF ESTIMATING ITS TRANSPORT DELAY
Directory of Open Access Journals (Sweden)
N. A. Dudarenko
2014-09-01
Full Text Available The paper deals with the problem of quantitative estimation for transport delay of linear continuous systems. The main result is received by means of fundamental matrix of linear differential equations solutions specified in the normal Cauchy form for the cases of SISO and MIMO systems. Fundamental matrix has the dual property. It means that the weight function of the system can be formed as a free motion of systems. Last one is generated by the vector of initial system conditions, which coincides with the matrix input of the system being researched. Thus, using the properties of the system- solving for fundamental matrix has given the possibility to solve the problem of estimating transport linear continuous system delay without the use of derivation procedure in hardware environment and without formation of exogenous Dirac delta function. The paper is illustrated by examples. The obtained results make it possible to solve the problem of modeling the pure delay links using consecutive chain of aperiodic links of the first order with the equal time constants. Modeling results have proved the correctness of obtained computations. Knowledge of transport delay can be used when configuring multi- component technological complexes and in the diagnosis of their possible functional degeneration.
Steenge, Albert E.; Thissen, Mark J.P.M.
2005-01-01
Economic systems often are described in matrix form as x = Mx. We present a new theorem for systems of this type where M is square, nonnegative and indecomposable. The theorem discloses the existence of additional economic relations that have not been discussed in the literature up to now, and gives
Classical R-matrix theory of dispersionless systems: I. (1+1)-dimension theory
Energy Technology Data Exchange (ETDEWEB)
Blaszak, Maciej; Szablikowski, Blazej M [Institute of Physics, A Mickiewicz University, Umultowska 85, 61-614 Poznan (Poland)
2002-12-06
A systematic way of construction of (1+1)-dimensional dispersionless integrable Hamiltonian systems is presented. The method is based on the classical R-matrix on Poisson algebras of formal Laurent series. Results are illustrated with the known and new (1+1)-dimensional dispersionless systems.
Classical R-matrix theory of dispersionless systems: II. (2+1) dimension theory
Energy Technology Data Exchange (ETDEWEB)
Blaszak, Maciej; Szablikowski, Blazej M [Institute of Physics, A Mickiewicz University, Umultowska 85, 61-614 Poznan (Poland)
2002-12-06
A systematic way of constructing (2+1)-dimensional dispersionless integrable Hamiltonian systems is presented. The method is based on the so-called central extension procedure and classical R-matrix applied to the Poisson algebras of formal Laurent series. Results are illustrated with the known and new (2+1)-dimensional dispersionless systems.
Computing the Moore-Penrose Inverse of a Matrix with a Computer Algebra System
Schmidt, Karsten
2008-01-01
In this paper "Derive" functions are provided for the computation of the Moore-Penrose inverse of a matrix, as well as for solving systems of linear equations by means of the Moore-Penrose inverse. Making it possible to compute the Moore-Penrose inverse easily with one of the most commonly used Computer Algebra Systems--and to have the blueprint…
On the Solution of a Class of Nonlinear Systems Governed by an -Matrix
Directory of Open Access Journals (Sweden)
Woula Themistoclakis
2012-01-01
Full Text Available We consider a weakly nonlinear system of the form (+(=, where ( is a real function of the unknown vector , and (+( is an -matrix. We propose to solve it by means of a sequence of linear systems defined by the iteration procedure (+(+1=, =0,1,…. The global convergence is proved by considering a related fixed-point problem.
Romero, Freddy; Pérez, Mariela; Chávez, Maribel; Parra, Gustavo; Durante, Paula
2009-12-01
In this work, we aimed to study the effect of uric acid on gentamicin-induced nephrotoxicity. Male Sprague-Dawley rats were assigned to one of six groups (six rats each) which received intraperitoneal injections for 9 days: (S) saline; (UA) Uric acid alone; (G) Gentamicin alone; (G + UA) Gentamicin + uric acid; (G rec) Gentamicin recovery and (G + UA rec) Gentamicin + uric acid recovery. In (G rec) and (G + UA rec), rats recovered for 7 days after the last injection. Urine and blood samples were taken on day 0 and at the end of every stage. Kidneys were harvested for histological scoring, determination of renal malondialdehyde (MDA), zymography and western blots for matrix metalloprotease (MMP)-2 and MMP-9. Uric acid alone did not provoke changes in biochemical and histological parameters when compared to controls. Gentamicin alone increased significantly plasma creatinine and blood urea nitrogen and caused a moderate histological damage. When combined with uric acid, these conditions worsened. MMP-9 activity and expression was decreased in rats from group G + UA as compared with rats from group G, while activity of MMP-2 was similarly increased in both groups when compared to controls. The increase in renal MDA induced by gentamicin was not altered when it was combined with uric acid. During the recovery stage, all biochemical parameters returned to normal levels, though a trend for delay of tubular damage recovery was observed in group G + UA rec when compared with group G rec. The results indicate that uric acid worsens gentamicin-induced nephrotoxicity. The mechanism is likely to implicate down-regulation of MMP-9.
Soni, Jalpa; Purwar, Harsh; Lakhotia, Harshit; Chandel, Shubham; Banerjee, Chitram; Kumar, Uday; Ghosh, Nirmalya
2013-07-01
A novel spectroscopic Mueller matrix system has been developed and explored for both fluorescence and elastic scattering polarimetric measurements from biological tissues. The 4 × 4 Mueller matrix measurement strategy is based on sixteen spectrally resolved (λ = 400 - 800 nm) measurements performed by sequentially generating and analyzing four elliptical polarization states. Eigenvalue calibration of the system ensured high accuracy of Mueller matrix measurement over a broad wavelength range, either for forward or backscattering geometry. The system was explored for quantitative fluorescence and elastic scattering spectroscopic polarimetric studies on normal and precancerous tissue sections from human uterine cervix. The fluorescence spectroscopic Mueller matrices yielded an interesting diattenuation parameter, exhibiting differences between normal and precancerous tissues.
Diglycolamic acid anchored on polyamine matrix for the mutual separation of Eu(III) and Am(III)
Energy Technology Data Exchange (ETDEWEB)
Suneesh, A.S.; Syamala, K.V.; Venkatesan, K.A.; Antony, M.P.; Vasudeva Rao, P.R. [Indira Gandhi Centre for Atomic Research, Kalpakkam (India). Fuel Chemistry Div.
2016-04-01
Diglycolamic acid was anchored on a polyamine matrix and the product (PA-DGAH) was characterized by ion-exchange capacity measurement, TG-DTA and FT-IR spectroscopy. The extraction behavior of Am(III) and Eu(III) in PA-DGAH was studied from dilute nitric acid medium to examine the feasibility using the anchored adsorbent for their mutual separation. The effect of various parameters such as the duration of equilibration, concentration of europium, nitric acid and diethylenetriaminepentaacetic acid (DTPA) in aqueous phase on the distribution coefficient (K{sub d}) of Am(III) and Eu(III) was studied. The distribution coefficient decreased with increase in the concentration of nitric acid. Rapid extraction of metal ions in the initial stages of equilibration followed by the establishment of equilibrium occurred within 4 h. The data on the rate of uptake of Am(III) and Eu(III) were fitted into pseudo-first order and pseudo-second order rate equation. The extraction isotherm was fitted to Langmuir and Freundlich adsorption models and the apparent europium extraction capacity was determined. The mechanism of extraction was elucidated and the conditions needed for efficient separation of Am(III) from Eu(III) was optimized using DTPA. The study indicated the possibility of using PA-DGAH for the separation of Eu(III) from Am(III) with high separation factors.
Prasad, Bhim Bali; Srivastava, Amrita; Tiwari, Mahavir Prasad
2013-10-01
A new molecularly imprinted polymer-matrix (titanium dioxide nanoparticle/multiwalled carbon nanotubes) nanocomposite was developed for the modification of pencil graphite electrode as an enantioselective sensing probe for aspartic acid isomers, prevalent at ultra trace level in aqueous and real samples. The nanocomposite having many shape complementary cavities was synthesized adopting surface initiated-activators regenerated by electron transfer for atom transfer radical polymerization. The proposed sensor has high stability, nanocomposite uniformity, good reproducibility, and enhanced electrocatalytic activity to respond oxidative peak current of L-aspartic acid quantitatively by differential pulse anodic stripping voltammetry, without any cross-reactivity in real samples. Under the optimized operating conditions, the L-aspartic acid imprinted modified electrode showed a wide linear response for L-aspartic acid within the concentration range 9.98-532.72 ng mL(-1), with the minimum detection limit of 1.73-1.79 ng mL(-1) (S/N=3) in aqueous and real samples. Almost similar stringent limit (1.79 ng mL(-1)) was obtained with cerebrospinal fluid which is typical for the primitive diagnosis of neurological disorders, caused by an acute depletion of L-aspartic acid biomarker, in clinical settings.
Motion Control for Nonholonomic Systems on Matrix Lie Groups
1998-01-01
exponentially stabilizing control law uSO(3) = H(x)ucfs(t, T (x)) (6.12) = H(x) = cosx2 cosx3 − sec x2 sinx3 − cos x2 sinx3 − sec x2 cosx3 given ω is...nilpotentization, we constructed exponentially stabilizing control laws for non-nilpotent systems by extending the region of attraction of otherwise only locally...California Institute of Technology. Morin, P., Pomet, J.-B., & Samson, C. 1996. Design of Homogeneous Time- Varying Stabilizing Control Laws for Driftless
Drug Release from Inert Spherical Matrix Systems Using Monte Carlo Simulations.
Villalobos, Rafael; Garcia, Erika V; Quintanar, David; Young, Paul M
2017-01-01
Computational approaches for predicting release properties from matrix devices have recently been purposed as an approach to better understand and predict such systems. The objective of this research is to study the behavior of drug delivery from inert spherical matrix systems of different size by means of computer simulation. To simulate the matrix medium, a simple cubic lattice was used, which was sectioned to make a spherical macroscopic system. The sites within the system were randomly occupied by drug-particles or excipient-particles in accordance with chosen drug/excipient ratios. Then, the drug was released from the matrix system simulating a diffusion process. When the released fraction was processed until 90% release, the Weibull equation suitably expressed the release profiles. On the basis of the analysis of release equations, it was found that close to the percolation threshold an anomalous released occurs, while in the systems with an initial drug load greater than 0.45, the released was Fickian type. It was also possible to determine the amount of drug trapped in the matrix, which was found to be a function of the initial drug load. The relationship between the two mentioned variables was adequately described by a model that involves the error function. Based on the these results and by means of a non-linear regression to the previous model, it was possible to determine the drug percolation threshold in these matrix devices. It was found that the percolation threshold is consistent with the value predicted by the percolation theory. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.
Energy Technology Data Exchange (ETDEWEB)
Cotte, F.P.; Doughty, C.; Birkholzer, J.
2010-11-01
The ability to reliably predict flow and transport in fractured porous rock is an essential condition for performance evaluation of geologic (underground) nuclear waste repositories. In this report, a suite of programs (TRIPOLY code) for calculating and analyzing flow and transport in two-dimensional fracture-matrix systems is used to model single-well injection-withdrawal (SWIW) tracer tests. The SWIW test, a tracer test using one well, is proposed as a useful means of collecting data for site characterization, as well as estimating parameters relevant to tracer diffusion and sorption. After some specific code adaptations, we numerically generated a complex fracture-matrix system for computation of steady-state flow and tracer advection and dispersion in the fracture network, along with solute exchange processes between the fractures and the porous matrix. We then conducted simulations for a hypothetical but workable SWIW test design and completed parameter sensitivity studies on three physical parameters of the rock matrix - namely porosity, diffusion coefficient, and retardation coefficient - in order to investigate their impact on the fracture-matrix solute exchange process. Hydraulic fracturing, or hydrofracking, is also modeled in this study, in two different ways: (1) by increasing the hydraulic aperture for flow in existing fractures and (2) by adding a new set of fractures to the field. The results of all these different tests are analyzed by studying the population of matrix blocks, the tracer spatial distribution, and the breakthrough curves (BTCs) obtained, while performing mass-balance checks and being careful to avoid some numerical mistakes that could occur. This study clearly demonstrates the importance of matrix effects in the solute transport process, with the sensitivity studies illustrating the increased importance of the matrix in providing a retardation mechanism for radionuclides as matrix porosity, diffusion coefficient, or retardation
Adaptive control of linear multivariable systems with high frequency gain matrix hurwitz
Institute of Scientific and Technical Information of China (English)
Ying ZHOU; Yuqiang WU; Shumin FEI
2005-01-01
A new adaptive control scheme is proposed for multivariable model reference adaptive control(MRAC) systems based on the nonlinear backstepping approach with vector form.The assumption on a priori knowledge of the high frequency gain matrix in existing results is relaxed and the new required condition for the high frequency gain matrix can be easily checked for certain plants so that the proposed method is widely applicable.This control scheme guarantees the global stability of the closed-loop systems and the tracking error can be arbitrary small.The simulation result for an application example shows the validity of the proposed nonlinear adaptive scheme.
Snorradóttir, Bergthóra S; Jónsdóttir, Fjóla; Sigurdsson, Sven Th; Másson, Már
2014-08-01
A model is presented for transdermal drug delivery from single-layered silicone matrix systems. The work is based on our previous results that, in particular, extend the well-known Higuchi model. Recently, we have introduced a numerical transient model describing matrix systems where the drug dissolution can be non-instantaneous. Furthermore, our model can describe complex interactions within a multi-layered matrix and the matrix to skin boundary. The power of the modelling approach presented here is further illustrated by allowing the possibility of a donor solution. The model is validated by a comparison with experimental data, as well as validating the parameter values against each other, using various configurations with donor solution, silicone matrix and skin. Our results show that the model is a good approximation to real multi-layered delivery systems. The model offers the ability of comparing drug release for ibuprofen and diclofenac, which cannot be analysed by the Higuchi model because the dissolution in the latter case turns out to be limited. The experiments and numerical model outlined in this study could also be adjusted to more general formulations, which enhances the utility of the numerical model as a design tool for the development of drug-loaded matrices for trans-membrane and transdermal delivery.
Institute of Scientific and Technical Information of China (English)
Shuang-suo Zhao; Zhang-hua Luo; Guo-feng Zhang
2000-01-01
This paper presents optimum an one-parameter iteration (OOPI) method and a multi-parameter iteration direct (MPID) method for efficiently solving linear algebraic systems with low order matrix A and high order matrix B: Y = (A B)Y +Ф. On parallel computers (also on serial computer) the former will be efficient, even very efficient under certain conditions, the latter will be universally very efficient.
A System of Four Matrix Equations over von Neumann Regular Rings and Its Applications
Institute of Scientific and Technical Information of China (English)
Qing Wen WANG
2005-01-01
We consider the system of four linear matrix equations A1X = C1, XB2 = C2, A3XB3 = C3 and A4XB4 = C4 over(R) , an arbitrary yon Neumann regular ring with identity. A necessary and sufficient condition for the existence and the expression of the general solution to the system are derived. As applications, necessary and sufficient conditions are given for the system of matrix equations A1X = C1 and A3X = C3 to have a bisymmetric solution, the system of matrix equations A1X = C1and A3XB3 = C3 to have a perselfconjugate solution over(R) with an involution and char ≠(R)2,respectively. The representations of such solutions are also presented. Moreover, some auxiliary results on other systems over(R)are obtained. The previous known results on some systems of matrix equations are special cases of the new results.
Kuş, N.; Sharma, A.; Peña, I.; Bermúdez, M. C.; Cabezas, C.; Alonso, J. L.; Fausto, R.
2013-04-01
β-aminoisobutyric acid (BAIBA) has been studied in isolation conditions: in the gas phase and trapped into a cryogenic N2 matrix. A solid sample of the compound was vaporized by laser ablation and investigated through their rotational spectra in a supersonic expansion using two different spectroscopic techniques: broadband chirped pulse Fourier transform microwave spectroscopy and conventional molecular beam Fourier transform microwave spectroscopy. Four conformers with structures of two types could be successfully identified by comparison of the experimental rotational and 14N nuclear quadruple coupling constants with those predicted theoretically: type A, bearing an OH⋯N intramolecular hydrogen bond and its carboxylic group in the trans geometry (H-O-C=O dihedral ˜180°), and type B, having an NH⋯O bond and the cis arrangement of the carboxylic group. These two types of conformers could also be trapped from the gas phase into a cryogenic N2 matrix and probed by Fourier transform infrared (IR) spectroscopy. In situ irradiation of BAIBA isolated in N2 matrix of type B conformers using near-IR radiation tuned at the frequency of the O-H stretching 1st overtone (˜6930 cm-1) of these forms allowed to selectively convert them into type A conformers and into a new type of conformers of higher energy (type D) bearing an NH⋯O=C bond and a O-H "free" trans carboxylic group.
McMillen, Chelsea L.; Wright, Patience M.; Cassady, Carolyn J.
2016-05-01
Matrix-assisted laser desorption/ionization (MALDI) in-source decay was studied in the negative ion mode on deprotonated peptides to determine its usefulness for obtaining extensive sequence information for acidic peptides. Eight biological acidic peptides, ranging in size from 11 to 33 residues, were studied by negative ion mode ISD (nISD). The matrices 2,5-dihydroxybenzoic acid, 2-aminobenzoic acid, 2-aminobenzamide, 1,5-diaminonaphthalene, 5-amino-1-naphthol, 3-aminoquinoline, and 9-aminoacridine were used with each peptide. Optimal fragmentation was produced with 1,5-diaminonphthalene (DAN), and extensive sequence informative fragmentation was observed for every peptide except hirudin(54-65). Cleavage at the N-Cα bond of the peptide backbone, producing c' and z' ions, was dominant for all peptides. Cleavage of the N-Cα bond N-terminal to proline residues was not observed. The formation of c and z ions is also found in electron transfer dissociation (ETD), electron capture dissociation (ECD), and positive ion mode ISD, which are considered to be radical-driven techniques. Oxidized insulin chain A, which has four highly acidic oxidized cysteine residues, had less extensive fragmentation. This peptide also exhibited the only charged localized fragmentation, with more pronounced product ion formation adjacent to the highly acidic residues. In addition, spectra were obtained by positive ion mode ISD for each protonated peptide; more sequence informative fragmentation was observed via nISD for all peptides. Three of the peptides studied had no product ion formation in ISD, but extensive sequence informative fragmentation was found in their nISD spectra. The results of this study indicate that nISD can be used to readily obtain sequence information for acidic peptides.
21 CFR 862.1775 - Uric acid test system.
2010-04-01
... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Uric acid test system. 862.1775 Section 862.1775....1775 Uric acid test system. (a) Identification. A uric acid test system is a device intended to measure uric acid in serum, plasma, and urine. Measurements obtained by this device are used in the diagnosis...
Hasan, Muhammad Sami; Ahmed, Ifty; Parsons, Andrew J; Rudd, Chris D; Walker, Gavin S; Scotchford, Colin A
2013-09-01
Eight different chemicals were investigated as potential candidate coupling agents for phosphate glass fibre reinforced polylactic acid composites. Evidence of reaction of the coupling agents with phosphate glass and their effect on surface wettability and glass degradation were studied along with their principle role of improving the interface between glass reinforcement and polymer matrix. It was found that, with an optimal amount of coupling agent on the surface of the glass/polymer, interfacial shear strength improved by a factor of 5. Evidence of covalent bonding between agent and glass was found for three of the coupling agents investigated, namely: 3-aminopropyltriethoxysilane; etidronic acid and hexamethylene diisocyanate. These three coupling agents also improved the interfacial shear strength and increased the hydrophobicity of the glass surface. It is expected that this would provide an improvement in the macroscopic properties of full-scale composites fabricated from the same materials which may also help to retain these properties for the desired length of time by retarding the breakdown of the fibre/matrix interface within these composites.
Testing the Predictions of Random Matrix Theory in Low Loss Wave Chaotic Scattering Systems
Yeh, Jen-Hao; Antonsen, Thomas; Ott, Edward; Anlage, Steven
2013-03-01
Wave chaos is a field where researchers apply random matrix theory (RMT) to predict the statistics of wave properties in complicated wave scattering systems. The RMT predictions have successfully demonstrated universality of the distributions of these wave properties, which only depend on the loss parameter of the system and the physical symmetry. Examination of these predictions in very low loss systems is interesting because extreme limits for the distribution functions and other predictions are encountered. Therefore, we use a wave-chaotic superconducting cavity to establish a low loss environment and test RMT predictions, including the statistics of the scattering (S) matrix and the impedance (Z) matrix, the universality (or lack thereof) of the Z- and S-variance ratios, and the statistics of the proper delay times of the Wigner-Smith time-delay matrix. We have applied an in-situ microwave calibration method (Thru-Reflection-Line method) to calibrate the cryostat system, and we also applied the random coupling model to remove the system-specific features. Our experimental results of different properties agree with the RMT predictions. This work is funded by the ONR/Maryland AppEl Center Task A2 (contract No. N000140911190), the AFOSR under grant FA95500710049, and Center for Nanophysics and Advanced Materials.
Peng, Li-Qing; Yi, Ling; Yang, Qiu-Cheng; Cao, Jun; Du, Li-Jing; Zhang, Qi-Dong
2017-08-08
A simple, rapid and eco-friendly approach based on matrix solid-phase dispersion microextraction (MSPDM) followed by ultrahigh performance liquid chromatography coupled with electrochemical detection (UHPLC-ECD) was presented for the microextraction and determination of six phenolic acids in a plant preparation (Danshen tablets). The parameters that influenced the extraction performance of phenolic acids were investigated and optimized. The optimal MSPDM conditions were determined as follows: sorbent, using graphene nanoplatelets with sample/sorbent ratio of 1:1, grinding time set at 60 s, and 0.2 mL of water as elution solvent. Under the optimum conditions, the validation experiments indicated that the proposed method exhibited good linearity (r(2) ≥ 0.9991), excellent precision (RSD ≤ 4.57%), and satisfactory recoveries (82.34-98.34%). The limits of detection were from 1.19 to 4.62 ng/mL for six phenolic acids. Compared with other reported methods, this proposal required less sample, solvent and extraction time. Consequently, the proposed method was successfully used to the extraction and determination of phenolic acids in Danshen tablets.
Energy Technology Data Exchange (ETDEWEB)
Prasad, Bhim Bali, E-mail: prof.bbpd@yahoo.com; Srivastava, Amrita; Tiwari, Mahavir Prasad
2013-10-15
A new molecularly imprinted polymer-matrix (titanium dioxide nanoparticle/multiwalled carbon nanotubes) nanocomposite was developed for the modification of pencil graphite electrode as an enantioselective sensing probe for aspartic acid isomers, prevalent at ultra trace level in aqueous and real samples. The nanocomposite having many shape complementary cavities was synthesized adopting surface initiated-activators regenerated by electron transfer for atom transfer radical polymerization. The proposed sensor has high stability, nanocomposite uniformity, good reproducibility, and enhanced electrocatalytic activity to respond oxidative peak current of L-aspartic acid quantitatively by differential pulse anodic stripping voltammetry, without any cross-reactivity in real samples. Under the optimized operating conditions, the L-aspartic acid imprinted modified electrode showed a wide linear response for L-aspartic acid within the concentration range 9.98–532.72 ng mL{sup −1}, with the minimum detection limit of 1.73–1.79 ng mL{sup −1} (S/N = 3) in aqueous and real samples. Almost similar stringent limit (1.79 ng mL{sup −1}) was obtained with cerebrospinal fluid which is typical for the primitive diagnosis of neurological disorders, caused by an acute depletion of L-aspartic acid biomarker, in clinical settings. Highlights: • We have adopted surface initiated-activators regenerated by electron transfer for atom transfer radical polymerization. • This approach takes advantage of the nanostructured ultrathin imprinted film. • Successful enantioselective sensing and ultratrace analysis of D- and L-aspartic acid. • Stringent detection limit without any non-specific false-positive contribution.
Lu, Zhilei; Chen, Weiyang; Hamman, Josias H; Ni, Jian; Zhai, Xiaoling
2008-01-01
The in vitro performance of monolithic matrix systems containing the interpolyelectrolyte complex between chitosan and polycarbophil as excipient was evaluated in terms of their swelling, bioadhesive, and drug release properties. The different matrix systems showed excellent swelling properties without erosion, except for the formulation containing the highest quantity chitosan-polycarbophil complex that exhibited surface erosion in addition to swelling. All the different matrix systems exhibited significantly higher bioadhesive properties than the control group. Furthermore, they showed controlled insulin release without an initial burst release effect. However, only the matrix system that exhibited surface erosion in combination with swelling approached zero-order release.
Ghasemalizadeh, Omid; Sadeghi, Hossein; Ahmadian, Mohammad Taghi
2013-01-01
One of the methods to find the natural frequencies of rotating systems is the application of the transfer matrix method. In this method the rotor is modeled as several elements along the shaft which have their own mass and moment of inertia. Using these elements, the entire continuous system is discretized and the corresponding differential equation can be stated in matrix form. The bearings at the end of the shaft are modeled as equivalent spring and dampers which are applied as boundary conditions to the discretized system. In this paper the dynamics of a rotor-bearing system is analyzed, considering the gyroscopic effect. The thickness of the disk and bearings is also taken into account. Continuous model is used for shaft. Results Show that, the stiffness of the shaft and the natural frequencies of the system increase, while the amplitude of vibration decreases as a consequence of increasing the thickness of the bearing.
Integrating random matrix theory predictions with short-time dynamical effects in chaotic systems.
Smith, A Matthew; Kaplan, Lev
2010-07-01
We discuss a modification to random matrix theory eigenstate statistics that systematically takes into account the nonuniversal short-time behavior of chaotic systems. The method avoids diagonalization of the Hamiltonian; instead it requires only knowledge of short-time dynamics for a chaotic system or ensemble of similar systems. Standard random matrix theory and semiclassical predictions are recovered in the limits of zero Ehrenfest time and infinite Heisenberg time, respectively. As examples, we discuss wave-function autocorrelations and cross correlations, and show that significant improvement in accuracy is obtained for simple chaotic systems where comparison can be made with brute-force diagonalization. The accuracy of the method persists even when the short-time dynamics of the system or ensemble is known only in a classical approximation. Further improvement in the rate of convergence is obtained when the method is combined with the correlation function bootstrapping approach introduced previously.
Global stabilization of linear periodically time-varying switched systems via matrix inequalities
Institute of Scientific and Technical Information of China (English)
无
2006-01-01
In this paper, we address the stabilization problem for linear periodically time-varying switched systems.Using discretization technique, we derive new conditions for the global stabilizability in terms of the solution of matrix inequalities. An algorithm for finding stabilizing controller and switching strategy is presented.
Chitosan-polycarbophil complexes in swellable matrix systems for controlled drug release.
Lu, Z; Chen, W; Hamman, J H
2007-10-01
A prerequisite for progress in the design of novel drug delivery systems is the development of excipients that are capable of fulfilling multifunctional roles such as controlling the release of the drug according to the therapeutic needs. Although several polymers have been utilised in the development of specialised drug delivery systems, their scope in dosage form design can be enlarged through combining different polymers. When a polymer is cross-linked or complexed with an oppositely charged polyelectrolyte, a three-dimensional network is formed in which the drug can be incorporated to control its release. The swelling properties and release kinetics of two model drugs with different water solubilities (i.e. diltiazem and ibuprofen) from monolithic matrix tablets consisting of an interpolyelectrolyte complex between chitosan and polycarbophil are reported. Matrix tablets consisting of this polymeric complex without drug or excipients exhibited extremely high swelling properties that are completely reversible upon drying. The drug release from matrix systems with different formulations depended on the concentration of the chitosan-polycarbophil interpolyelectrolyte complex and approached zero order release kinetics for both model drugs. The chitosan-polycarbophil interpolyelectrolyte complex has demonstrated a high potential as an excipient for the production of swellable matrix systems with controlled drug release properties.
Linear System of Equations, Matrix Inversion, and Linear Programming Using MS Excel
El-Gebeily, M.; Yushau, B.
2008-01-01
In this note, we demonstrate with illustrations two different ways that MS Excel can be used to solve Linear Systems of Equation, Linear Programming Problems, and Matrix Inversion Problems. The advantage of using MS Excel is its availability and transparency (the user is responsible for most of the details of how a problem is solved). Further, we…
Robust Beamforming for Amplify-and-Forward MIMO Relay Systems Based on Quadratic Matrix Programming
Xing, Chengwen; Wu, Yik-Chung; Ng, Tung-Sang
2010-01-01
In this paper, robust transceiver design based on minimum-mean-square-error (MMSE) criterion for dual-hop amplify-and-forward MIMO relay systems is investigated. The channel estimation errors are modeled as Gaussian random variables, and then the effect are incorporated into the robust transceiver based on the Bayesian framework. An iterative algorithm is proposed to jointly design the precoder at the source, the forward matrix at the relay and the equalizer at the destination, and the joint design problem can be efficiently solved by quadratic matrix programming (QMP).
Li, K; Safavi-Naeini, M; Franklin, D R; Han, Z; Rosenfeld, A B; Hutton, B; Lerch, M L F
2015-09-07
A common approach to improving the spatial resolution of small animal PET scanners is to reduce the size of scintillation crystals and/or employ high resolution pixellated semiconductor detectors. The large number of detector elements results in the system matrix--an essential part of statistical iterative reconstruction algorithms--becoming impractically large. In this paper, we propose a methodology for system matrix modelling which utilises a virtual single-layer detector ring to greatly reduce the size of the system matrix without sacrificing precision. Two methods for populating the system matrix are compared; the first utilises a geometrically-derived system matrix based on Siddon's ray tracer method with the addition of an accurate detector response function, while the second uses Monte Carlo simulation to populate the system matrix. The effectiveness of both variations of the proposed technique is demonstrated via simulations of PETiPIX, an ultra high spatial resolution small animal PET scanner featuring high-resolution DoI capabilities, which has previously been simulated and characterised using classical image reconstruction methods. Compression factors of 5 x 10(7) and 2.5 x 10(7)are achieved using this methodology for the system matrices produced using the geometric and Monte Carlo-based approaches, respectively, requiring a total of 0.5-1.2 GB of memory-resident storage. Images reconstructed from Monte Carlo simulations of various point source and phantom models, produced using system matrices generated via both geometric and simulation methods, are used to evaluate the quality of the resulting system matrix in terms of achievable spatial resolution and the CRC, CoV and CW-SSIM index image quality metrics. The Monte Carlo-based system matrix is shown to provide the best image quality at the cost of substantial one-off computational effort and a lower (but still practical) compression factor. Finally, a straightforward extension of the virtual ring
Cheng, Wei; Xu, Fang; Li, Hua; Wang, Gang
2014-04-01
Given the density matrix of a bipartite quantum state, could we decide whether it is separable, free entangled, or PPT entangled? Here, we give a negative answer to this question by providing a lot of concrete examples of density matrices, some of which are well known. We find that both separability and distillability are dependent on the decomposition of the density matrix. To be more specific, we show that if a given matrix is considered as the density operators of different composite systems, their entanglement properties might be different. In the case of density matrices, we can look them as both and bipartite quantum states and show that their entanglement properties (i.e., separable, free entangled, or PPT entangled) are completely irrelevant to each other.
Investigation of fracture-matrix interaction: Preliminary experiments in a simple system
Energy Technology Data Exchange (ETDEWEB)
Foltz, S.D. [New Mexico Univ., Albuquerque, NM (United States). Dept. of Physics and Astronomy; Tidwell, V.C.; Glass, R.J.; Sobolik, S.R. [Sandia National Labs., Albuquerque, NM (United States)
1992-12-31
Paramount to the modeling of unsaturated flow and transport through fractured porous media is a clear understanding of the processes controlling fracture-matrix interaction. As a first step toward such an understanding, two preliminary experiments have been performed to investigate the influence of matrix imbibition on water percolation through unsaturated fractures in the plane normal to the fracture. Test systems consisted of thin slabs of either tuff or an analog material cut by a single vertical fracture into which a constant fluid flux was introduced. Transient moisture content and solute concentration fields were imaged by means of x-ray absorption. Flow fields associated with the two different media were significantly different owing to differences in material properties relative to the imposed flux. Richards` equation was found to be a valid means of modeling the imbibition of water into the tuff matrix from a saturated fracture for the current experiment.
Transfer matrix analysis of backscattering and reflection effects on WDM-PON systems.
Simatupang, Joni Welman; Lee, San-Liang
2013-11-18
This paper proposes using power transfer matrix analysis to characterize the effects of Rayleigh backscattering and Fresnel reflection on WDM-PON systems. The modeling of a WDM-PON system can be carried out simply by matrix multiplication of the corresponding matrices for all the building blocks, where all possible guided backward lights and resonant configurations along the optical network can be accounted for. The total sum of all interferences affecting the bidirectional transmission that leads to an optical crosstalk-to-signal (C/S) ratio can be modeled as back-reflections through cascaded two-port networks for the downstream and upstream signals. This approach is simple, robust, efficient, and also accurate. Its accuracy is verified for simple system architectures and then applied to study more complicated cases. The results show its versatility to analyze a wide variety of bidirectional optical transmission systems.
Monteyne, Tinne; Adriaensens, Peter; Brouckaert, Davinia; Remon, Jean-Paul; Vervaet, Chris; De Beer, Thomas
2016-10-15
Granules with release-sustaining properties were developed by twin screw hot melt granulation (HMG) using a combination of stearic acid (SA) and high molecular weight polyethylene oxide (PEO) as matrix for a highly water soluble model drug, metoprolol tartrate (MPT). Earlier studies demonstrated that mixing molten SA and PEO resulted in hydrogen bond formation between hydroxyl groups of fatty acid molecules and ether groups in PEO chains. These molecular interactions might be beneficial in order to elevate the sustained release effect of drugs from a SA/PEO matrix. This study aims to investigate the continuous twin screw melt granulation technique to study the impact of a SA/PEO matrix on the dissolution rate of a highly water soluble drug (MPT). Decreasing the SA/PEO ratio improved the release-sustaining properties of the matrix. The solid state of the granules was characterized using differential scanning calorimetry (DSC), nuclear magnetic resonance (NMR), X-ray diffraction (XRD), Raman spectroscopy, Fourier transform infrared (FTIR) and near infrared chemical imaging (NIR-CI) in order to understand the dissolution behavior. The results revealed a preferential interaction of the MPT molecules with stearic acid impeding the PEO to form hydrogen bonds with the stearic acid chains. However, this allowed the PEO chains to recrystallize inside the stearic acid matrix after granulation, hence, elevating the release-sustaining characteristics of the formulation.
Matrix Factorization and Matrix Concentration
Mackey, Lester
2012-01-01
Motivated by the constrained factorization problems of sparse principal components analysis (PCA) for gene expression modeling, low-rank matrix completion for recommender systems, and robust matrix factorization for video surveillance, this dissertation explores the modeling, methodology, and theory of matrix factorization.We begin by exposing the theoretical and empirical shortcomings of standard deflation techniques for sparse PCA and developing alternative methodology more suitable for def...
A 9 × 9 Matrix Representation of Birman-Wenzl-Murakami Algebra and Berry Phase in Yang-Baxter System
Institute of Scientific and Technical Information of China (English)
GOU Li-Dan; XUE Kang; WANG Gang-Cheng
2011-01-01
We present a 9 × 9 S-matrix and E-matrix. A representation of specialized Birman-Wenzl-Murakami algebra is obtained. Starting from the given braid group representation S-matrix, we obtain the trigonometric solution of Yang-Baxter equation. A unitary matrix R(x,φ1,φ2) is generated via the Yang-Baxterization approach. Then we construct a Yang-Baxter Hamiltonian through the unitary matrixR(x, φ1, φ2). Berry phase of this Yang-Baxter system is investigated in detail.
Institute of Scientific and Technical Information of China (English)
CAO Guo-yun; ZHANG Qing; CHUNG T S; CHEN Chen
2008-01-01
Properties of the active power/angle sub-matrix in the power flow Jacobian for power system analysis are studied. The sub-matrix is a dominant and irreducible matrix under very general conditions of power systems, so that it is invertible. Also the necessary conditions for its singularity are given. These theoretical rsuts can be used to clarify the ambiguous understanding of the sub-matrix in current literature, and also provide the theoretical foundations for the applications based on reduced power flow Jacobian. Numerical simulation on the IEEE 118-bus power system is used to illustrate our results.
A matrix transformation approach to H∞ control via static output feedback for input delay systems
Du, B; Shu, Z; Lam, J.
2009-01-01
This paper addresses the static output feedback (SOF) H∞ control for continuous-time linear systems with an unknown input delay from a novel perspective. New equivalent characterizations on the stability and H∞ performance of the closed-loop system are established in terms of nonlinear matrix inequalities with free parametrization matrices. These delay-dependent characterizations possess a special monotonic structure, which leads to linearized iterative computation. The effectiveness and meri...
A matrix structured LED backlight system with 2D-DHT local dimming method
Liu, Jia; Li, Yang; Du, Sidan
To reduce the number of the drivers in the conventional local dimming method for LCDs, a novel LED backlight local dimming system is proposed in this paper. The backlight of this system is generated by 2D discrete Hadamard transform and its matrix structured LED modules. Compared with the conventional 2D local dimming method, the proposed method costs much fewer drivers but with little degradation.
Lorenzo, Jose M; Munekata, Paulo Eduardo Sichetti; Pateiro, Mirian; Campagnol, Paulo Cezar Bastianello; Domínguez, Ruben
2016-11-01
Reduction of fat content and improving fatty acid composition were the strategies used to reformulate Spanish salchichón with better lipid content by partial substitution of pork backfat by microencapsulated fish oil in konjac glucomannan matrix. For the present study, four different batches were manufactured: control (CO) with 100% of pork backfat and ME25, ME50 and ME75 where the pork backfat was replaced with 25, 50 and 75% by microencapsulated fish oil, respectively. The fat replacement by microencapsulated fish oil was accompanied by a decrease (P0.001) decreased the fat content (30.4%) as compared with the CO group. The total amount of PUFA in the modified sausages increased by 2.3% compared to the control batches. Finally, the reformulation process showed a significant (P<0.05) increase in the lipid oxidation (TBARs values and aldehydes content) related to the greater susceptibility to lipid oxidation of unsaturated (particularly EPA and DHA) fatty acids. To conclude, it is technologically feasible to develop Spanish salchichón enriched with microencapsulated n-3 fatty acids from fish oil. Copyright © 2016 Elsevier Ltd. All rights reserved.
Directory of Open Access Journals (Sweden)
Hai-gen Yang
2015-09-01
Full Text Available The complex mechanical systems such as high-speed trains, multiple launch rocket system, self-propelled artillery, and industrial robots are becoming increasingly larger in scale and more complicated in structure. Designing these products often requires complex model design, multibody system dynamics calculation, and analysis of large amounts of data repeatedly. In recent 20 years, the transfer matrix method of multibody system has been widely applied in engineering fields and welcomed at home and in abroad for the following features: without global dynamic equations of the system, low orders of involved system matrices, high computational efficiency, and high programming. In order to realize the rapid and visual simulation for complex mechanical system virtual design using transfer matrix method of multibody system, a virtual design software named MSTMMSim is designed and implemented. In the MSTMMSim, the transfer matrix method of multibody system is used as the solver for dynamic modeling and calculation; the Open CASCADE is used for solid geometry modeling. Various auxiliary analytical tools such as curve plot and animation display are provided in the post-processor to analyze and process the simulation results. Two numerical examples are given to verify the validity and accuracy of the software, and a multiple launch rocket system engineering example is given at the end of this article to show that the software provides a powerful platform for complex mechanical systems simulation and virtual design.
Directory of Open Access Journals (Sweden)
B. Grabowska
2013-04-01
Full Text Available This publication describes research on the course of the process of cross-linking new BioCo polymer binders - in the form of water-based polymer compositions of poly(acrylic acid or poly(sodium acrylate/modified polysaccharide - using selected physical and chemical factors. It has been shown that the type of cross-linking factor used influences the strength parameters of the moulding sand. The crosslinking factors selected during basic research make it possible to obtain sand strengths similar to those of samples of sands bonded with commercial binders. Microwave radiation turned out to be the most effective cross-linking factor in a binder-matrix system. It was proven that adsorption in the microwave radiation field leads to the formation of polymer lattices with hydrogen bonds which play a major role in maintaining the formed cross-linked structures in the binder-matrix system. As a result, the process improves the strength parameters of the sand, whereas the hardening process in a microwave field significantly shortens the setting time.
Institute of Scientific and Technical Information of China (English)
陈野; 蔡伟民; 孙晓君; 崔丹; 于英宁
2004-01-01
Europium ternary complex of Eu (NNA)3(NNA=o-naphthylacetic acid) was embedded in silica matrix at different ratios by sol-gel method. The luminescence properties of silica composites were studied by comparing them with those of corresponding pure complex by means of excitation, emission spectra and lifetimes. The fluorescence lifetime was prolonged when the pure complex was incorporated in silica matrix. The relative fluorescence intensity and fluorescence lifetimes increased simultaneously with the increase of Eu(NNA)3.
Parameter identification of fractional order linear system based on Haar wavelet operational matrix.
Li, Yuanlu; Meng, Xiao; Zheng, Bochao; Ding, Yaqing
2015-11-01
Fractional order systems can be more adequate for the description of dynamical systems than integer order models, however, how to obtain fractional order models are still actively exploring. In this paper, an identification method for fractional order linear system was proposed. This is a method based on input-output data in time domain. The input and output signals are represented by Haar wavelet, and then fractional order systems described by fractional order differential equations are transformed into fractional order integral equations. Taking use of the Haar wavelet operational matrix of the fractional order integration, the fractional order linear system can easily be converted into a system of algebraic equation. Finally, the parameters of the fractional order system are determined by minimizing the errors between the output of the real system and that of the identified system. Numerical simulations, involving integral and fractional order systems, confirm the efficiency of the above methodology.
Directory of Open Access Journals (Sweden)
T. Vaupel
2004-01-01
Full Text Available Using integral equation methods for the analysis of complex (MMIC structures, the computation and storage effort for the solution of the linear systems of equations with their fully populated matrices still forms the main bottleneck. In the last years, remarkable improvements could be achieved by means of diakoptic methods and related preconditiners. In this contribution, we present a method based on the optimized decomposition of the system matrix depending on the circuit topology. The system matrix is splitted in a densely populated matrix and a mainly blockdiagonal matrix with overlapping submatrices. The latter matrix is used for the generation of high performance preconditioners within Krylov subspace methods using sparsified matrix storage methods, adaptive Cholesky decompositions and optimized forward/backward substitutions. Furthermore, we present an integration technique using a complete analytical treatment for the strongly oscillating parts of the spectral domain integrands allowing the analysis of very large structures as compared to the wavelength.
Iterative solutions to the steady-state density matrix for optomechanical systems
Nation, P. D.; Johansson, J. R.; Blencowe, M. P.; Rimberg, A. J.
2015-01-01
We present a sparse matrix permutation from graph theory that gives stable incomplete lower-upper preconditioners necessary for iterative solutions to the steady-state density matrix for quantum optomechanical systems. This reordering is efficient, adding little overhead to the computation, and results in a marked reduction in both memory and runtime requirements compared to other solution methods, with performance gains increasing with system size. Either of these benchmarks can be tuned via the preconditioner accuracy and solution tolerance. This reordering optimizes the condition number of the approximate inverse and is the only method found to be stable at large Hilbert space dimensions. This allows for steady-state solutions to otherwise intractable quantum optomechanical systems.
Iterative solutions to the steady state density matrix for optomechanical systems
Nation, P D; Blencowe, M P; Rimberg, A J
2014-01-01
We present a sparse matrix permutation from graph theory that gives stable incomplete Lower-Upper (LU) preconditioners necessary for iterative solutions to the steady state density matrix for quantum optomechanical systems. This reordering is efficient, adding little overhead to the computation, and results in a marked reduction in both memory and runtime requirements compared to other solution methods, with performance gains increasing with system size. Either of these benchmarks can be tuned via the preconditioner accuracy and solution tolerance. This reordering optimizes the condition number of the approximate inverse, and is the only method found to be stable at large Hilbert space dimensions. This allows for steady state solutions to otherwise intractable quantum optomechanical systems.
Method to modify random matrix theory using short-time behavior in chaotic systems.
Smith, A Matthew; Kaplan, Lev
2009-09-01
We discuss a modification to random matrix theory (RMT) eigenstate statistics that systematically takes into account the nonuniversal short-time behavior of chaotic systems. The method avoids diagonalization of the Hamiltonian, instead requiring only knowledge of short-time dynamics for a chaotic system or ensemble of similar systems. Standard RMT and semiclassical predictions are recovered in the limits of zero Ehrenfest time and infinite Heisenberg time, respectively. As examples, we discuss wave-function autocorrelations and cross correlations and show how the approach leads to a significant improvement in the accuracy for simple chaotic systems where comparison can be made with brute-force diagonalization.
Energy Technology Data Exchange (ETDEWEB)
Ortuno, J E; Kontaxakis, G; Rubio, J L; Santos, A [Departamento de Ingenieria Electronica (DIE), Universidad Politecnica de Madrid, Ciudad Universitaria s/n, 28040 Madrid (Spain); Guerra, P [Networking Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Madrid (Spain)], E-mail: juanen@die.upm.es
2010-04-07
A fully 3D iterative image reconstruction algorithm has been developed for high-resolution PET cameras composed of pixelated scintillator crystal arrays and rotating planar detectors, based on the ordered subsets approach. The associated system matrix is precalculated with Monte Carlo methods that incorporate physical effects not included in analytical models, such as positron range effects and interaction of the incident gammas with the scintillator material. Custom Monte Carlo methodologies have been developed and optimized for modelling of system matrices for fast iterative image reconstruction adapted to specific scanner geometries, without redundant calculations. According to the methodology proposed here, only one-eighth of the voxels within two central transaxial slices need to be modelled in detail. The rest of the system matrix elements can be obtained with the aid of axial symmetries and redundancies, as well as in-plane symmetries within transaxial slices. Sparse matrix techniques for the non-zero system matrix elements are employed, allowing for fast execution of the image reconstruction process. This 3D image reconstruction scheme has been compared in terms of image quality to a 2D fast implementation of the OSEM algorithm combined with Fourier rebinning approaches. This work confirms the superiority of fully 3D OSEM in terms of spatial resolution, contrast recovery and noise reduction as compared to conventional 2D approaches based on rebinning schemes. At the same time it demonstrates that fully 3D methodologies can be efficiently applied to the image reconstruction problem for high-resolution rotational PET cameras by applying accurate pre-calculated system models and taking advantage of the system's symmetries.
Kota, V K B
2015-01-01
Embedded random matrix ensembles are generic models for describing statistical properties of finite isolated interacting quantum many-particle systems. For the simplest spinless systems, with say $m$ particles in $N$ single particle states and interacting via $k$-body interactions, we have EGUE($k$) and the embedding algebra is $U(N)$. A finite quantum system, induced by a transition operator, makes transitions from its states to the states of the same system or to those of another system. Examples are electromagnetic transitions (same initial and final systems), nuclear beta and double beta decay (different initial and final systems), particle addition to/removal from a given system and so on. Towards developing a complete statistical theory for transition strength densities, we have derived formulas for lower order bivariate moments of the strength densities generated by a variety of transition operators. For a spinless fermion system, using EGUE($k$) representation for Hamiltonian and an independent EGUE($...
Zhang, Jian; Sun, Pingping; Zhao, Xiaowei; Ma, Zhiqiang
2014-12-21
The extracellular matrix proteins (ECMs) are widely found in the tissues of multicellular organisms. They consist of various secreted proteins, mainly polysaccharides and glycoproteins. The ECMs involve the exchange of materials and information between resident cells and the external environment. Accurate identification of ECMs is a significant step in understanding the evolution of cancer as well as promises wide range of potential applications in therapeutic targets or diagnostic markers. In this paper, an accurate computational method named PECM is proposed for identifying ECMs. Here, we explore various sequence-derived discriminative features including evolutionary information, predicted secondary structure, and physicochemical properties. Rather than simply combining the features which may bring information redundancy and unwanted noises, we use Fisher-Markov selector and incremental feature selection approach to search the optimal feature subsets. Then, we train our model by the technique of support vector machine (SVM). PECM achieves good prediction performance with the ACC scores about 86% and 90% on testing and independent datasets, which are competitive with the state-of-the-art ECMs prediction tools. A web-server named PECM which implements the proposed approach is freely available at http://59.73.198.144:8088/PECM/.
Developing a Health Information Technology Systems Matrix: A Qualitative Participatory Approach.
Haun, Jolie N; Chavez, Margeaux; Nazi, Kim M; Antinori, Nicole
2016-10-06
The US Department of Veterans Affairs (VA) has developed various health information technology (HIT) resources to provide accessible veteran-centered health care. Currently, the VA is undergoing a major reorganization of VA HIT to develop a fully integrated system to meet consumer needs. Although extensive system documentation exists for various VA HIT systems, a more centralized and integrated perspective with clear documentation is needed in order to support effective analysis, strategy, planning, and use. Such a tool would enable a novel view of what is currently available and support identifying and effectively capturing the consumer's vision for the future. The objective of this study was to develop the VA HIT Systems Matrix, a novel tool designed to describe the existing VA HIT system and identify consumers' vision for the future of an integrated VA HIT system. This study utilized an expert panel and veteran informant focus groups with self-administered surveys. The study employed participatory research methods to define the current system and understand how stakeholders and veterans envision the future of VA HIT and interface design (eg, look, feel, and function). Directed content analysis was used to analyze focus group data. The HIT Systems Matrix was developed with input from 47 veterans, an informal caregiver, and an expert panel to provide a descriptive inventory of existing and emerging VA HIT in four worksheets: (1) access and function, (2) benefits and barriers, (3) system preferences, and (4) tasks. Within each worksheet is a two-axis inventory. The VA's existing and emerging HIT platforms (eg, My HealtheVet, Mobile Health, VetLink Kiosks, Telehealth), My HealtheVet features (eg, Blue Button, secure messaging, appointment reminders, prescription refill, vet library, spotlight, vitals tracker), and non-VA platforms (eg, phone/mobile phone, texting, non-VA mobile apps, non-VA mobile electronic devices, non-VA websites) are organized by row. Columns
Toda Theories, Matrix Models, Topological Strings, and N=2 Gauge Systems
Dijkgraaf, Robbert
2009-01-01
We consider the topological string partition function, including the Nekrasov deformation, for type IIB geometries with an A_{n-1} singularity over a Riemann surface. These models realize the N=2 SU(n) superconformal gauge systems recently studied by Gaiotto and collaborators. Employing large N dualities we show why the partition function of topological strings in these backgrounds is captured by the chiral blocks of A_{n-1} Toda systems and derive the dictionary recently proposed by Alday, Gaiotto and Tachikawa. For the case of genus zero Riemann surfaces, we show how these systems can also be realized by Penner-like matrix models with logarithmic potentials. The Seiberg-Witten curve can be understood as the spectral curve of these matrix models which arises holographically at large N. In this context the Nekrasov deformation maps to the beta-ensemble of generalized matrix models, that in turn maps to the Toda system with general background charge. We also point out the notion of a double holography for this...
Directory of Open Access Journals (Sweden)
Albert I. Ugochukwu
2011-06-01
Full Text Available The Nigerian rice sector has made remarkable improvementin the last decade as production has increased significantlythereby reducing the gap between domestic supply and demand.In the last three decades, rice imports make up greater proportionof Nigerian imports as rice forms a structural component ofthe Nigerian diet. Past government inconsistent policies werenot successful in securing good market share for domestic riceproducers, hence producers suffered great losses. The recentresurgence of interest by the present administration to intensifydomestic rice production has yielded positive results. The objective of this study is to analyze and assess the costs andbenefits of intensification of rice production systems in southeastern Nigeria using a policy analysis matrix approach. MultiStage sampling technique was employed in selecting 75 uplandand 75 lowland rice farmers who were interviewed withstructured and validated questionnaire. Data were analyzedusing Policy Analysis Matrix (PAM. The result shows thatupland; lowland and double rice cropping systems in southeasternNigeria are profitable based on the policy analysis matrix(PAM model, and rice production under various systems andtechnologies is socially profitable and financially competitive.While there exist comparative advantage in the variousproduction systems, with lowland and double cropping beinghighest, substantial tax was imposed on rice imports in Nigeriaand government investment in intensifying rice productionhad a positive impact on the output of local rice production.The study concludes with strategies for the development ofrice sub sector in Nigeri
Effect of Phosphoric Acid on the Degradation of Human Dentin Matrix
Tezvergil-Mutluay, A.; Mutluay, M.; Seseogullari-Dirihan, R.; Agee, K.A.; Key, W.O.; Scheffel, D.L.S.; Breschi, L.; Mazzoni, A.; Tjäderhane, L.; Nishitani, Y.; Tay, F.R.; Pashley, D.H.
2013-01-01
This study determined if dentin proteases are denatured by phosphoric acid (PA) used in etch-and-rinse dentin adhesives. Dentin beams were completely demineralized with EDTA for 30 days. We “acid-etched” experimental groups by exposing the demineralized dentin beams to 1, 10, or 37 mass% PA for 15 sec or 15 min. Control beams were not exposed to PA but were incubated in simulated body fluid for 3 days to assay their total endogenous telopeptidase activity, by their ability to solubilize C-terminal crosslinked telopeptides ICTP and CTX from insoluble dentin collagen. Control beams released 6.1 ± 0.8 ng ICTP and 0.6 ± 0.1 ng CTX/mg dry-wt/3 days. Positive control beams pre-incubated in p-aminophenylmercuric acetate, a compound known to activate proMMPs, released about the same amount of ICTP peptides, but released significantly less CTX. Beams immersed in 1, 10, or 37 mass% PA for 15 sec or 15 min released amounts of ICTP and CTX similar to that released by the controls (p > 0.05). Beams incubated in galardin, an MMP inhibitor, or E-64, a cathepsin inhibitor, blocked most of the release of ICTP and CTX, respectively. It is concluded that PA does not denature endogenous MMP and cathepsin activities of dentin matrices. PMID:23103634
DEFF Research Database (Denmark)
Pivnenko, Sergey; Nielsen, Jeppe Majlund; Breinbjerg, Olav
2011-01-01
Two higher-order probe-correction techniques for spherical near-field antenna measurements are compared in details for the accuracy they provide and their computational cost. The investigated techniques are the FFT/matrix inversion and the system matrix inversion. Each of these techniques allows...... and a higher-order probe....... correction of general high-order probes, including non-symmetric dual-polarized antennas with independent ports. The investigation was carried out by processing with each technique the same measurement data for a challenging case with an antenna under test significantly offset from the center of rotation...
Institute of Scientific and Technical Information of China (English)
Xiao-Ting Rui; Edwin Kreuzer; Bao Rong; Bin He
2012-01-01
In this paper,by defining new state vectors and developing new transfer matrices of various elements moving in space,the discrete time transfer matrix method of multi-rigid-flexible-body system is expanded to study the dynamics of muhibody system with flexible beams moving in space.Formulations and numerical example of a rigidflexible-body three pendulums system moving in space are given to validate the method. Using the new method to study the dynamics of multi-rigid-flexible-body system mov ing in space,the global dynamics equations of system are not needed,the orders of involved matrices of the system are very low and the computational speed is high,irrespective of the size of the system.The new method is simple,straightforward,practical,and provides a powerful tool for multi-rigid-flexible-body system dynamics.
Thermal front propagation in variable aperture fracture-matrix system: A numerical study
Indian Academy of Sciences (India)
Nikhil Bagalkot; G Suresh Kumar
2015-04-01
A numerical study on the effect of complex fracture aperture geometry on propagation of thermal front in a coupled single fracture-matrix system has been carried out. Sinusoidal and logarithmic functions have been used to capture the variation in fracture aperture. Modifications have been made to existing coupled partial differential governing equations to consider the variation of fracture aperture. Effect of temperature on the thermal and physical properties of rock have been incorporated. A fully implicit finite difference scheme has been used to discretize the coupled governing equations. Thermal convection, dispersion and conduction are the major transport processes within fracture, while conduction is the major transport process within rock matrix. The results suggest that variation of fracture aperture increases the heat transfer rate at the fracture-matrix interface. Sensitivity analysis on rock thermal conductivity and fracture aperture have been carried out. The results suggest that the heat transfer from rock matrix to fracture for the case of the parallel plate model is greatly dependent on the rock thermal conductivity (m) as compared to variable aperture model. Further, the thermal front propagation for both parallel plate model and variable aperture model is sensitive to changes in fracture aperture. The heat transfer rate at the interface is greater at smaller fracture apertures and decreases with increase in aperture.
The matrix representation of fuzzy knowledge and its application to the expert systems design
Directory of Open Access Journals (Sweden)
V. Levchenko
1993-02-01
Full Text Available An approach to the diagnostic type expert systems design based on the special matrix representation of fuzzy predicates in the tribute model of the problem domain is presented. Intensive representation of predicates by means of sectional matrices is an analogue of the conjunctive normal form. Rules, positive examples and negative examples (in general, all fuzzy can be used to form knowledge base. Diagnostics problem is thought of as finding some attribute values provided that the information about other attribute values is available. Logical inference is based on an equivalent transformation of the matrix to that containing all prime disjuncts by using the operation of fuzzy resolution . Two strategies to carry out such transformation are described. On the basis of formalism presented the expert system shell EDIP is developed, the first version of that is non-fuzzy and the second one allows working with fuzzy data and conclusions.
Metal-insulator transition in disordered systems from the one-body density matrix
DEFF Research Database (Denmark)
Olsen, Thomas; Resta, Raffaele; Souza, Ivo
2017-01-01
systems. In particular, for noninteracting systems the geometrical marker can be obtained from the configurational average of the norm-squared one-body density matrix, which can be calculated within open as well as periodic boundary conditions. This is in sharp contrast to a classification based...... on the static conductivity, which is only sensible within periodic boundary conditions. We exemplify the method by considering a simple lattice model, known to have a metal-insulator transition as a function of the disorder strength, and demonstrate that the transition point can be obtained accurately from...... the one-body density matrix. The approach has a general ab initio formulation and could in principle be applied to realistic disordered materials by standard electronic structure methods....
A Multi-Interference-Channel Matrix Pair Beamformer for CDMA Systems
Wang, Jian; Yuan, Jian; Ge, Ning; Wei, Shuangqing
2010-01-01
Matrix pair beamformer (MPB) is a promising blind beamformer which exploits the temporal signature of the signal of interest (SOI) to acquire its spatial statistical information. It does not need any knowledge of directional information or training sequences. However, the major problem of the existing MPBs is that they have serious threshold effects and the thresholds will grow as the interference power increases or even approach infinity. In particular, this issue prevails in scenarios with structured interference, such as, periodically repeated white noise, tones, or MAIs in multipath channels. In this paper, we will first present the principles for designing the projection space of the MPB which are closely correlated with the ability of suppressing structured interference and system finite sample performance. Then a multiple-interference-channel based matrix pair beamformer (MIC-MPB) for CDMA systems is developed according to the principles. In order to adapt to dynamic channels, an adaptive algorithm for...
(Anti-Hermitian Generalized (Anti-Hamiltonian Solution to a System of Matrix Equations
Directory of Open Access Journals (Sweden)
Juan Yu
2014-01-01
Full Text Available We mainly solve three problems. Firstly, by the decomposition of the (anti-Hermitian generalized (anti-Hamiltonian matrices, the necessary and sufficient conditions for the existence of and the expression for the (anti-Hermitian generalized (anti-Hamiltonian solutions to the system of matrix equations AX=B,XC=D are derived, respectively. Secondly, the optimal approximation solution minX∈K∥X^-X∥ is obtained, where K is the (anti-Hermitian generalized (anti-Hamiltonian solution set of the above system and X^ is the given matrix. Thirdly, the least squares (anti-Hermitian generalized (anti-Hamiltonian solutions are considered. In addition, algorithms about computing the least squares (anti-Hermitian generalized (anti-Hamiltonian solution and the corresponding numerical examples are presented.
Matrix metalloproteinases: a review of their structure and role in systemic sclerosis.
Peng, Wen-jia; Yan, Jun-wei; Wan, Ya-nan; Wang, Bing-xiang; Tao, Jin-hui; Yang, Guo-jun; Pan, Hai-feng; Wang, Jing
2012-12-01
Matrix metalloproteinases (MMPs) are the main enzymes involved in arterial wall extracellular matrix (ECM) degradation and remodeling, whose activity has been involved in various normal and pathologic processes, such as inflammation, fibrosis. As a result, the MMPs have come to consider as both therapeutic targets and diagnostic tools for the treatment and diagnosis of autoimmune diseases, including systemic lupus erythematosus and rheumatoid arthritis. Systemic sclerosis (SSc) is a rare autoimmune disease of unknown etiology characterized by an excessive over-production of collagen and other ECM, resulting in skin thickening and fibrosis of internal organs. In recent years, abnormal expression of MMPs has been demonstrated with the pathogenesis of SSc, and the association of different polymorphisms on MMPs genes with SSc has been extensively studied. This review describes the structure, function and regulation of MMPs and shortly summarizes current understanding on experimental findings, genetic associations of MMPs in SSc.
Fast and accurate generation method of PSF-based system matrix for PET reconstruction
Sun, Xiao-Li; Yun, Ming-Kai; Li, Dao-Wu; Gao, Juan; Li, Mo-Han; Chai, Pei; Tang, Hao-Hui; Zhang, Zhi-Ming; Wei, Long
2016-01-01
Positional single photon incidence response (P-SPIR) theory is researched in this paper to generate more accurate PSF-contained system matrix simply and quickly. The method has been proved highly effective to improve the spatial resolution by applying to the Eplus-260 primate PET designed by the Institute of High Energy Physics of the Chinese Academy of Sciences(IHEP). Simultaneously, to meet the clinical needs, GPU acceleration is put to use. Basically, P-SPIR theory takes both incidence angle and incidence position by crystal subdivision instead of only incidence angle into consideration based on Geant4 Application for Emission Tomography (GATE). The simulation conforms to the actual response distribution and can be completed rapidly within less than 1s. Furthermore,two-block penetration and normalization of the response probability are raised to fit the reality. With PSF obtained, the homogenization model is analyzed to calculate the spread distribution of bins within a few minutes for system matrix genera...
Hong, Seong-Min; Tanaka, Mitsuru; Yoshii, Saori; Mine, Yoshinori; Matsui, Toshiro
2013-11-05
Enhanced visualization of small peptides absorbed through a rat intestinal membrane was achieved by matrix-assisted laser desorption/ionization time-of-flight imaging mass spectrometry (MALDI-IMS) with the aid of phytic acid as a matrix additive. Penetrants through intestinal peptide transporter 1, i.e., glycyl-sarcosine (Gly-Sar, 147.1 m/z) and antihypertensive dipeptide, Val-Tyr (281.2 m/z), were chosen for MALDI-IMS. The signal-to-noise (S/N) ratios of dipeptides Gly-Sar and Val-Tyr were seen to increase by 2.4- and 8.0-fold, respectively, when using a 2',4',6'-trihydroxyacetophenone (THAP) matrix containing 5.0 mM phytic acid, instead of the THAP matrix alone. Owing to the phytic-acid-aided MALDI-IMS method, Gly-Sar and Val-Tyr absorbed in the rat intestinal membrane were successfully visualized. The proposed imaging method also provided useful information on intestinal peptide absorption; to some extent, Val-Tyr was rapidly hydrolyzed to Tyr by peptidases located at the intestinal microvillus during the absorption process. In conclusion, the strongly acidic additive, phytic acid, is beneficial for enhancing the visualization of small peptides using MALDI-IMS, owing to the suppression of ionization-interfering salts in the tissue.
Thin Film Heat Flux Sensor Development for Ceramic Matrix Composite (CMC) Systems
Wrbanek, John D.; Fralick, Gustave C.; Hunter, Gary W.; Zhu, Dongming; Laster, Kimala L.; Gonzalez, Jose M.; Gregory, Otto J.
2010-01-01
The NASA Glenn Research Center (GRC) has an on-going effort for developing high temperature thin film sensors for advanced turbine engine components. Stable, high temperature thin film ceramic thermocouples have been demonstrated in the lab, and novel methods of fabricating sensors have been developed. To fabricate thin film heat flux sensors for Ceramic Matrix Composite (CMC) systems, the rough and porous nature of the CMC system posed a significant challenge for patterning the fine features required. The status of the effort to develop thin film heat flux sensors specifically for use on silicon carbide (SiC) CMC systems with these new technologies is described.
Dominance-based Matrix algorithm for Knowledge Reductions in Incomplete Fuzzy Information System
Directory of Open Access Journals (Sweden)
Lixin Fan
2013-07-01
Full Text Available In this paper，definitions of knowledge granulation and rough entropy are proposed based on dominance relations in incomplete fuzzy information system, and important properties are obtained. It can be found that using the definitions can measure uncertainty of an attribute set in the incomplete fuzzy information systems. A matrix algorithm for attributes reduction is acquired in the systems. An example illustrates the validity of this algorithm, and results of compared with other existing methods show that the algorithm is an efficient tool for data mining.
Passivity-Based Nonlinear Excitation Control of Power Systems with Structure Matrix Reassignment
Directory of Open Access Journals (Sweden)
Bing Chu
2013-08-01
Full Text Available Passivity-based control is widely used in electronic circuit systems because it can utilize their internal structures to facilitate the controller design. In this paper, we first propose a dissipative Hamiltonian realization of power systems and discuss the disadvantages of the traditional passivity-based excitation controller. Then, a novel excitation controller is put forward to reassign the interconnection and dissipative matrix, and the corresponding Hamiltonian function. Simulation results verify that the proposed controller can effectively improve the transient stability of the power system.
Terzi, Erdinc; Guvenc, Ulas; Türsen, Belma; Kaya, Tamer İrfan; Erdem, Teoman; Türsen, Ümit
2015-01-01
Ingrown toenail is an often painful clinical condition that usually affects the big toe. Chemical matricectomy with phenol has a low recurrence rate and good cosmetic results. However, it produces extensive tissue destruction that can result in drainage and delayed healing. Alternatives such as sodium hydroxide and trichloroacetic acid (TCA) have therefore come into vogue. A total of 39 patients with 56 ingrown toenail edges underwent chemical matricectomy with 90% TCA after partial nail avulsion. In most of the patients, adverse effects such as postoperative pain and drainage were minimal. One patient who underwent matricectomy had recurrence in a single nail edge (1.8%) at 12 months follow-up. No recurrence was observed among 38 patients during the mean follow-up period. This was considered to be statistically significant (P < 0.001). Partial nail avulsion followed by TCA matricectomy is a safe, simple, and effective method with low rates of postoperative morbidity and high rates of success.
Fluorescence Properties of Eu3+/Gd3+/Citric Acid Mixed Complexes Doping in Silicon Rubber Matrix
Institute of Scientific and Technical Information of China (English)
无
2006-01-01
Series of doped rare earth complexes-EuxGd(1-x)(CA)3·nH2O (CA=citric acid) were synthesized. Some characterizations were taken for these complexes. The experimental results shows that the doped rare earth complexes have the best fluorescence property when the ratio of Eu and Gd is from 0.7 to 0.3. Silicon rubber-based composites were prepared by mechanical blending the EuxGd(1-x)(CA)3·nH2O and silicon rubber. Then, the fluorescent property of the composites was studied. It is found that the fluorescence intensity of the composites increase linearly with the contents of the rare earth complexes increasing.
Oscillation Criteria Based on a New Weighted Function for Linear Matrix Hamiltonian Systems
Directory of Open Access Journals (Sweden)
Yingxin Guo
2011-01-01
Full Text Available By employing a generalized Riccati technique and an integral averaging technique, some new oscillation criteria are established for the second-order matrix differential system U′=A(xU+B(tV, V′=C(xU−A∗(tV, where A(t, B(t, and C(t are (n×n-matrices, and B, C are Hermitian. These results are sharper than some previous results.
Sharma, Sandeep; Alavi, Ali
2015-01-01
We propose a multireference linearized coupled cluster theory using matrix product states (MPS-LCC) which provides remarkably accurate ground-state energies, at a computational cost that has the same scaling as multireference configuration interaction singles and doubles (MRCISD), for a wide variety of electronic Hamiltonians. These range from first-row dimers at equilibrium and stretched geometries, to highly multireference systems such as the chromium dimer and lattice models such as period...
Qualley, Dominic F; Lackey, Crystal M; Paterson, Justin P
2013-08-01
The matrix (MA) domain of retroviral Gag proteins plays a crucial role in virion assembly. In human immunodeficiency virus type 1 (HIV-1), a lentivirus, the presence of phosphatidylinositol-(4,5)-bisphosphate triggers a conformational change allowing the MA domain to bind the plasma membrane (PM). In this study, the MA protein from bovine leukemia virus (BLV) was used to investigate the mechanism of viral Gag binding to the membrane during replication of a deltaretrovirus. Fluorescence spectroscopy was used to measure the binding affinity of MA for two RNA constructs derived from the BLV genome as well as for single-stranded DNA (ssDNA). The importance of electrostatic interactions and the ability of inositol hexakisphosphate (IP6) to compete with nucleic acids for binding to MA were also investigated. Our data show that IP6 effectively competes with RNA and DNA for BLV MA binding, while [NaCl] of greater than 100 mM is required to produce any observable effect on DNA-MA binding. These results suggest that BLV assembly may be highly dependent on the specific interaction of the MA domain with components of the PM, as observed previously with HIV-1. The mode of MA binding to nucleic acids and the implications for BLV assembly are discussed.
Baseline Design Compliance Matrix for the Rotary Mode Core Sampling System
Energy Technology Data Exchange (ETDEWEB)
LECHELT, J.A.
2000-10-17
The purpose of the design compliance matrix (DCM) is to provide a single-source document of all design requirements associated with the fifteen subsystems that make up the rotary mode core sampling (RMCS) system. It is intended to be the baseline requirement document for the RMCS system and to be used in governing all future design and design verification activities associated with it. This document is the DCM for the RMCS system used on Hanford single-shell radioactive waste storage tanks. This includes the Exhauster System, Rotary Mode Core Sample Trucks, Universal Sampling System, Diesel Generator System, Distribution Trailer, X-Ray Cart System, Breathing Air Compressor, Nitrogen Supply Trailer, Casks and Cask Truck, Service Trailer, Core Sampling Riser Equipment, Core Sampling Support Trucks, Foot Clamp, Ramps and Platforms and Purged Camera System. Excluded items are tools such as light plants and light stands. Other items such as the breather inlet filter are covered by a different design baseline. In this case, the inlet breather filter is covered by the Tank Farms Design Compliance Matrix.
Li, Yonggao; Zhou, Yan; Yuan, Baoshan; Deng, Zhongchao; Zhang, Boyu; Li, Yuan; Deng, Wei; Wang, Haoxi; Yi, Jiang; HL-2A Team
2016-12-01
A new electron density profile reconstruction procedure based on the PARK-matrix method has been firstly exploited for the multi-chord formic acid (HCOOH, λ=432.5 μm) laser interferometry system on the HL-2A tokamak. According to the geometric coordinates of the magnetic surfaces reconstructed by the CF (current fitting) code and the assumption that the electron density between two adjacent magnetic surfaces is a constant, the local electron density is calculated layer by layer, and the electron density profile ne(Z) can be determined, as well as the density profile ne(R). The simulation result indicates that the error of the PARK-matrix method is acceptable for the four-chord HCOOH laser interferometer. In the applications, it shows that the reconstructed electron density profile agrees well with the microwave reflectometry measurement, and the sawtooth reversion radius is consistent with that deduced from the soft X-ray signals. Meanwhile, the electron density profiles with electron cyclotron resonance heating (ECRH) and supersonic molecular beam injection (SMBI) are also reconstructed and analyzed. supported by the National Magnetic Confinement Fusion Science Program of China (No. 2014GB109001), and National Natural Science Foundation of China (Nos. 11505053 and 11275059)
Twisted Six Dimensional Gauge Theories on Tori, Matrix Models,and Integrable Systems
Ganguli, S N; Gill, J A; Ganguli, Surya; Ganor, Ori J.; Gill, James A.
2004-01-01
We use the Dijkgraaf-Vafa technique to study massive vacua of 6D SU(N) SYM theories on tori with R-symmetry twists. One finds a matrix model living on the compactification torus with a genus-2 spectral curve whose Jacobian is closely related to a twisted four torus T in which the Seiberg-Witten curves of the theory are embedded. We also analyze R-symmetry twists in a bundle with nontrivial first Chern class which yields intrinsically 6D SUSY breaking and a novel matrix integral in which eigenvalues float in a sea of background charge. Next we analyze the underlying integrable system of the theory, whose phase space we show to be a system of N-1 points on T. We write down an explicit set of Poisson commuting Hamiltonians for this system for arbitrary N and use them to prove that equilbrium configurations with respect to all Hamiltonians correspond to points in moduli space where the Seiberg-Witten curve maximally degenerates to genus 2, thereby recovering the matrix model spectral curve. We also write down a c...
Development and Clinical Evaluation of MatrixMANDIBLE Subcondylar Plates System (Synthes).
Cortelazzi, Roberto; Altacera, Mario; Turco, Monica; Antonicelli, Viviana; De Benedittis, Michele
2015-06-01
In this article, authors report the different steps of development and clinical validation of MatrixMANDIBLE Subcondylar Plates (Synthes, Soletta, Switzerland), a specialized osteosynthesis system developed by Synthes during the past 4 years. Between 2009 and 2013, a total of 62 patients were treated for subcondylar and condylar neck fractures via a preauricular or retromandibular/transparotid approach. The MatrixMANDIBLE Subcondylar Plates System consists of a Trapezoidal Plate, a three-dimensional (3D) 4-hole 1.0-mm plate for smaller fracture areas, the Lambda Plate, a 7-hole 1.0-mm linear plate which mimics the two miniplates technique, and the Strut Plate, a 3D 1.0-mm plate with great versatility of employment. All devices satisfy the principles of a functionally stable osteosynthesis as stated by Champy et al. None of the plates broke and no macroscopic condylar displacement was noted on radiological follow-up. Clinical and functional parameters assessed at 6 months postoperative (mandibular range of motion, pain, dental occlusion) were almost restored. MatrixMANDIBLE Subcondylar Plates System (Synthes) has proved to provide sufficient mechanical stiffness and anatomically accurate fracture reduction to avoid major postoperative drawbacks of subcondylar and condylar neck fractures.
Directory of Open Access Journals (Sweden)
Gupta Khemchand
2011-06-01
Full Text Available The major objective of this study was to use pectin (high methoxylated in combination with guar gum to control the burst effect by promoting gelation and also to examine the release pattern of guar-pectin matrices. Guar gum has long been used to prepare matrix tablets. But its uncontrolled rate of hydration and initial slow gelling results into undesirable burst effect. Various combination of drug: polymer ratios were tried, out of which the ratio 1:2 yielded best results. The ratio of gaur: pectin in the polymer blend which gave best results was found to be 1:1.The effects of various diluents on the drug release were also determined at the same polymer level. The matrix tablet were prepared by wet granulation method using distilled water, were subjected to physical characterization and in vitro release studies. Release kinetics was evaluated by using USP apparatus type II at 100 rpm in 900 ml of acidic dissolution medium ( pH 1.2 for two hours, followed by 900 ml phosphate buffer dissolution medium (pH 6.8.The in-vitro drug release study revealed that (batch F3 combining pectin with guar gum sustained the drug release for 10 hours (87.54±2.36% release. Fitting the in-vitro drug release data to Korsmeyer-Peppas equation indicated that diffusion along with erosion could be the mechanism of drug release. At the same polymer level the order of release fell in the following manner lactose, avicel pH 101, starch and Emcompress®. It was concluded from the study that guar-pectin binary polymeric matrix system is an interesting alternative for preparing sustained release tablets.
Bahrehmand, F; Vaisi-Raygani, A; Kiani, A; Rahimi, Z; Tavilani, H; Ardalan, M; Vaisi-Raygani, H; Shakiba, E; Pourmotabbed, T
2015-05-01
Systemic lupus erythematosus (SLE) is an autoimmune disease that involves multiple organs and is characterized by persistent systemic inflammation. Among the effects of inflammatory mediators, the induction of matrix metalloproteinases-2 and -9 (MMP-2 and MMP-9) and oxidative stress has been demonstrated to be important in the development of SLE. In this study, the possible association between MMP-9 and MMP-2 functional promoter polymorphism, stress, and inflammatory markers with development of severe cardiovascular disease (CVD), high blood pressure (HBP), and lupus nephropathy (LN) in SLE patients was investigated. The present case-control study consisted of 109 SLE patients with and without CVD, HBP and LN and 101 gender- and age-matched unrelated healthy controls from a population in western Iran. MMP-2 -G1575A and MMP-9 -C1562T polymorphisms were detected by PCR-RFLP, serum MMP-2 and MMP-9, neopterin, malondialdehyde (MDA) and lipid levels were determined by ELISA, HPLC and enzyme assay, respectively. We found that MMP-9 -C1562 T and MMP-2 -G1575A alleles act synergistically to increase the risk of SLE by 2.98 times (p = 0.015). Findings of this study also demonstrated that there is a significant increase in the serum levels of MMP-2, neopterin and MDA and a significant decrease in serum level of MMP-9 in the presence of MMP-9-C1562 T and MMP-2 -G1575A alleles in SLE patients compared to controls. Further, SLE patients with MMP-9 (C/T + T/T) genotype had significantly higher serum concentrations of MMP-2, neopterin, MDA and LDL-C, but lower serum MMP-9 and HDL-C levels than corresponding members of the control group. MMP-9 (C/T + T/T) genotype increased risk of hypertension in SLE patients 2.71-fold. This study for the first time not only suggests that MMP-9 -C1562 T and MMP-2 -G1575A alleles synergistically increase the risk of SLE but also high serum levels of MDA, neopterin, and circulatory levels of MMP-2 and lower MMP-9 in SLE patients. This
Matrix-product states for strongly correlated systems and quantum information processing
Energy Technology Data Exchange (ETDEWEB)
Saberi, Hamed
2008-12-12
This thesis offers new developments in matrix-product state theory for studying the strongly correlated systems and quantum information processing through three major projects: In the first project, we perform a systematic comparison between Wilson's numerical renormalization group (NRG) and White's density-matrix renormalization group (DMRG). The NRG method for solving quantum impurity models yields a set of energy eigenstates that have the form of matrix-product states (MPS). White's DMRG for treating quantum lattice problems can likewise be reformulated in terms of MPS. Thus, the latter constitute a common algebraic structure for both approaches. We exploit this fact to compare the NRG approach for the single-impurity Anderson model to a variational matrix-product state approach (VMPS), equivalent to single-site DMRG. For the latter, we use an ''unfolded'' Wilson chain, which brings about a significant reduction in numerical costs compared to those of NRG. We show that all NRG eigenstates (kept and discarded) can be reproduced using VMPS, and compare the difference in truncation criteria, sharp vs. smooth in energy space, of the two approaches. Finally, we demonstrate that NRG results can be improved upon systematically by performing a variational optimization in the space of variational matrix-product states, using the states produced by NRG as input. In the second project we demonstrate how the matrix-product state formalism provides a flexible structure to solve the constrained optimization problem associated with the sequential generation of entangled multiqubit states under experimental restrictions. We consider a realistic scenario in which an ancillary system with a limited number of levels performs restricted sequential interactions with qubits in a row. The proposed method relies on a suitable local optimization procedure, yielding an efficient recipe for the realistic and approximate sequential generation of any
Lecht, Shimon; Cohen-Arazi, Naomi; Cohen, Gadi; Ettinger, Keren; Momic, Tatjana; Kolitz, Michal; Naamneh, Majdi; Katzhendler, Jehoshua; Domb, Abraham J; Lazarovici, Philip; Lelkes, Peter I
2014-01-01
One of the challenges in regenerative medicine is the development of novel biodegradable materials to build scaffolds that will support multiple cell types for tissue engineering. Here we describe the preparation, characterization, and cytocompatibility of homo- and hetero-polyesters of α-hydroxy amino acid derivatives with or without lactic acid conjugation. The polymers were prepared by a direct condensation method and characterized using gel permeation chromatography, (1)H-nuclear magnetic resonance spectroscopy, Fourier transform infrared spectroscopy, differential scanning calorimetry, optical activity, and solubility. The surface charge of the polymers was evaluated using zeta potential measurements. The polymers were coated onto glass cover slips followed by characterization using nano-surface profiler, thin film reflectometry, and atomic force microscopy (AFM). Their interaction with endothelial and neuronal cells was assessed using adhesion, proliferation, and differentiation assays. Of the characterized polymers, Poly-HOVal-LA, but not Poly-(D)HOPhe, significantly augmented nerve growth factor (NGF)-induced neuronal differentiation of the PC12 pheochromcytoma cells. In contrast, Poly-HOLeu increased by 20% the adhesion of endothelial cells, but did not affect PC12 cell differentiation. NGF-induced Erk1/2 phosphorylation in PC12 cells grown on the different polymers was similar to the effect observed for cells cultured on collagen type I. While no significant association could be established between charge and the differentiative/proliferative properties of the polymers, AFM analysis indicated augmentation of NGF-induced neuronal differentiation on smooth polymer surfaces. We conclude that overall selective cytocompatibility and bioactivity might render α-hydroxy amino acid polymers useful as extracellular matrix-mimicking materials for tissue engineering.
Vesiculoviral matrix (M) protein occupies nucleic acid binding site at nucleoporin pair (Rae1∙Nup98)
Energy Technology Data Exchange (ETDEWEB)
Quan, Beili; Seo, Hyuk-Soo; Blobel, Günter; Ren, Yi [Rockefeller
2014-07-01
mRNA export factor 1 (Rae1) and nucleoporin 98 (Nup98) are host cell targets for the matrix (M) protein of vesicular stomatitis virus (VSV). How Rae1 functions in mRNA export and how M protein targets both Rae1 and Nup98 are not understood at the molecular level. To obtain structural insights, we assembled a 1:1:1 complex of M•Rae1•Nup98 and established a crystal structure at 3.15-Å resolution. We found that the M protein contacts the Rae1•Nup98 heterodimer principally by two protrusions projecting from the globular domain of M like a finger and thumb. Both projections clamp to the side of the β-propeller of Rae1, with the finger also contacting Nup98. The most prominent feature of the finger is highly conserved Methionine 51 (Met51) with upstream and downstream acidic residues. The complementary surface on Rae1 displays a deep hydrophobic pocket, into which Met51 fastens like a bolt, and a groove of basic residues on either side, which bond to the acidic residues of the finger. Notably, the M protein competed for in vitro binding of various oligonucleotides to Rae1•Nup98. We localized this competing activity of M to its finger using a synthetic peptide. Collectively, our data suggest that Rae1 serves as a binding protein for the phosphate backbone of any nucleic acid and that the finger of M mimics this ligand. In the context of mRNA export, we propose that a given mRNA segment, after having been deproteinated by helicase, is transiently reproteinated by Nup98-tethered Rae1. We suggest that such repetitive cycles provide cytoplasmic stopover sites required for ratcheting mRNA across the nuclear pore.
Chitrattha, Sasiprapa; Phaechamud, Thawatchai
2016-01-01
Poly(lactic acid) (PLA) is polymeric biomaterial that has been used for wound dressing due to its biodegradability and biocompatibility. However, PLA has some limitations including poor toughness, low degradation rate and high hydrophobicity. The aim of this study is to develop an antibiotic drug-loaded PLA porous film as wound dressing with antibacterial activity. PLA porous film was fabricated by temperature change technique using solvent casting method. Polyethylene glycol (PEG) 400 was added for improving the pore interconnectivity of film. Gentamicin sulfate (GS) or metronidazole (MZ) was incorporated into PLA porous films. PLA containing PEG 400 exhibited the more amorphous form than plain PLA film and contained 55.31 ± 2.85% porosity and 20 μm of the pore size which significantly improved the water vapor transmission rate, oxygen transmission rate, degradation rate and percentage of drug release, respectively. Drug-loaded porous films efficiently inhibited the bacteria growth. GS-loaded film inhibited Staphylococcus aureus, Proteus mirabilis, Pseudomonas aeruginosa, whereas MZ-loaded film inhibited Bacteroides fragilis and the sustainable antibacterial activity was attained for 7 days.
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Erdinc Terzi
2015-01-01
Full Text Available Ingrown toenail is an often painful clinical condition that usually affects the big toe. Chemical matricectomy with phenol has a low recurrence rate and good cosmetic results. However, it produces extensive tissue destruction that can result in drainage and delayed healing. Alternatives such as sodium hydroxide and trichloroacetic acid (TCA have therefore come into vogue. A total of 39 patients with 56 ingrown toenail edges underwent chemical matricectomy with 90% TCA after partial nail avulsion. In most of the patients, adverse effects such as postoperative pain and drainage were minimal. One patient who underwent matricectomy had recurrence in a single nail edge (1.8% at 12 months follow-up. No recurrence was observed among 38 patients during the mean follow-up period. This was considered to be statistically significant (P < 0.001. Partial nail avulsion followed by TCA matricectomy is a safe, simple, and effective method with low rates of postoperative morbidity and high rates of success.
Docosahexaenoic acid suppresses breast cancer cell metastasis by targeting matrix-metalloproteinases
Shin, Soyeon; Kim, Soyeon; Heo, Jun-Young; Kweon, Gi-Ryang; Wu, Tong; Park, Jong-Il; Lim, Kyu
2016-01-01
Breast cancer is one of the most prevalent cancers in women, and nearly half of breast cancer patients develop distant metastatic disease after therapy. Despite the significant advances that have been achieved in understanding breast cancer metastasis in the past decades, metastatic cancer is still hard to cure. Here, we demonstrated an anti-cancer mechanism of docosahexaenoic acid (DHA) that suppressed lung metastasis in breast cancer. DHA could inhibit proliferation and invasion of breast cancer cells in vitro, and this was mainly through blocking Cox-2-PGE2-NF-κB-MMPs cascades. DHA treatment significantly decreased Cox-2 and NF-κB expression as well as nuclear translocation of NF-κB in MDA-MB-231 cells. In addition, DHA also reduced NF-κB binding to DNA which may lead to inactivation of MMPs. Moreover, in vivo studies using Fat-1 transgenic mice showed remarkable decrease of tumor growth and metastasis to EO771 cells to lung in DHA-rich environment. In conclusion, DHA attenuated breast cancer progression and lung metastasis in part through suppressing MMPs, and these findings suggest chemoprevention and potential therapeutic strategy to overcome malignant breast cancer. PMID:27363023
Luciani-Giacobbe, Laura C; Ramírez-Rigo, María V; Garro-Linck, Yamila; Monti, Gustavo A; Manzo, Ruben H; Olivera, María E
2017-01-01
One of the main obstacles to the successful treatment of tuberculosis is the poor and variable oral bioavailability of rifampicin (RIF), which is mainly due to its low hydrophilicity and dissolution rate. The aim of this work was to obtain a hydrophilic new material that allows a very fast dissolution rate of RIF and therefore is potentially useful in the development of oral solid dosage forms. The acid form of carboxymethylcellulose (CMC) was co-processed with RIF by solvent impregnation to obtain CMC-RIF powder, which was characterized by polarized optical microscopy, powder x-ray diffraction, DSC-TGA, hot stage microscopy, (13)C and (15)N solid-state NMR and FT-IR spectroscopy. In addition, the CMC-RIF matrices were subjected to water uptake and dissolution studies to assess hydrophilicity and release kinetics. CMC-RIF is a crystalline solid dispersion. Solid-state characterization indicated that no ionic interaction occurred between the components, but RIF crystallized as a zwitterion over the surface of CMC, which drastically increased the hydrophilicity of the solid. The CMC-RIF matrices significantly improved the water uptake of RIF and disintegrated in a very short period immediately releasing RIF. As CMC improves the hydrophilicity and delivery properties of RIF, CMC-RIF is very useful in the design of oral solid dosage forms with very fast dissolution of RIF, either alone or in combination with other antitubercular drugs. Copyright © 2016 Elsevier B.V. All rights reserved.
Monteyne, Tinne; Adriaensens, Peter; Brouckaert, Davinia; Remon, Jean-Paul; Vervaet, Chris; De Beer, Thomas
2016-01-01
Granules with release-sustaining properties were developed by twin screw hot melt granulation (HMG) using a combination of stearic acid (SA) and high molecular weight polyethylene oxide (PEO) as matrix for a highly water soluble model drug, metoprolol tartrate (MPT). Earlier studies demonstrated that mixing molten SA and PEO resulted in hydrogen bond formation between hydroxyl groups of fatty acid molecules and ether groups in PEO chains. These molecular interactions might be beneficial in or...
A 222 energy bins response matrix for a {sup 6}Lil scintillator Bss system
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Lacerda, M. A. S. [Centro de Desenvolvimento da Tecnologia Nuclear, Laboratorio de Calibracao de Dosimetros, Av. Pte. Antonio Carlos 6627, 31270-901 Pampulha, Belo Horizonte, Minas Gerais (Brazil); Vega C, H. R. [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas, Zac. (Mexico); Mendez V, R. [Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas, Laboratorio de Patrones Neutronicos, Av. Complutense 22, 28040 Madrid (Spain); Lorente F, A.; Ibanez F, S.; Gallego D, E., E-mail: masl@cdtn.br [Universidad Politecnica de Madrid, Departamento de Ingenieria Nuclear, 28006 Madrid (Spain)
2016-10-15
A new response matrix was calculated for a Bonner Sphere Spectrometer (Bss) with a {sup 6}Lil(Eu) scintillator. We utilized the Monte Carlo N-particle radiation transport code MCNPX, version 2.7.0, with Endf/B-VII.0 nuclear data library to calculate the responses for 6 spheres and the bare detector, for energies varying from 9.441 E(-10) MeV to 105.9 MeV, with 20 equal-log(E)-width bins per energy decade, totalizing 222 energy groups. A Bss, like the modeled in this work, was utilized to measure the neutron spectrum generated by the {sup 241}AmBe source of the Universidad Politecnica de Madrid. From the count rates obtained with this Bss system we unfolded neutron spectrum utilizing the BUNKIUT code for 31 energy bins (UTA-4 response matrix) and the MAXED code with the new calculated response functions. We compared spectra obtained with these Bss system / unfold codes with that obtained from measurements performed with a Bss system constituted of 12 spheres with a spherical {sup 3}He Sp-9 counter (Centronic Ltd., UK) and MAXED code with the system-specific response functions (Bss-CIEMAT). A relatively good agreement was observed between our response matrix and that calculated by other authors. In general, we observed an improvement in the agreement as the energy increases. However, higher discrepancies were observed for energies close to 1-E(-8) MeV and, mainly, for energies above 20 MeV. These discrepancies were mainly attributed to the differences in cross-section libraries employed. The ambient dose equivalent (H (10)) calculated with the {sup 6}Lil-MAXED showed a good agreement with values measured with the neutron area monitor Bert hold Lb 6411 and within 12% the value obtained with another Bss system (Bss-CIEMAT). The response matrix calculated in this work can be utilized together with the MAXED code to generate neutron spectra with a good energy resolution up to 20 MeV. Some additional tests are being done to validate this response matrix and improve the
Miranpuri, Gurwattan S.; Meethal, Sivan Vadakkadath; Sampene, Emmanuel; Chopra, Abhishek; Buttar, Seah; Nacht, Carrie; Moreno, Neydis; Patel, Kush; Liu, Lisa; Singh, Anupama; Singh, Chandra K.; Hariharan, Nithya; Iskandar, Bermans; Resnick, Daniel K.
2017-01-01
Background The molecular underpinnings of spinal cord injury (SCI) associated with neuropathic pain (NP) are unknown. Recent studies have demonstrated that matrix metalloproteinases (MMPs) such as MMP2 play a critical role in inducing NP following SCI. Promoter methylation of MMPs is known to suppress their transcription and reduce NP. In this context, it has been shown in rodents that folic acid (FA), an FDA approved dietary supplement and key methyl donor in the central nervous system (CNS), increases axonal regeneration and repair of injured CNS in part via methylation. Purpose Based on above observations, in this study, we test whether FA could decrease MMP2 expression and thereby decrease SCI-induced NP. Methods Sprague-Dawley male rats weighing 250–270 g received contusion spinal cord injuries (cSCIs) with a custom spinal cord impactor device that drops a 10 g weight from a height of 12.5 mm. The injured rats received either i.p. injections of FA (80 µg/kg) or water (control) 3 days prior and 17 days post-cSCI (mid phase) or for 3 days pre-cSCI and 14 days post-cSCI ending on the 42nd day of cSCI (late phase). The functional neurological deficits due to cSCI were then assessed by Basso, Beattie, and Bresnahan (BBB) scores either on post-impaction days 0 through 18 post-cSCI (mid phase) or on days 0, 2, 7, 14, 21, 28, 35, and 42 (late phase). Baseline measurements were taken the day before starting treatments. Thermal hyperalgesia (TH) testing for pain was performed on 4 days pre-cSCI (baseline data) and on days 18, 21, 28, 35, and 42 post-cSCI. Following TH testing, animals were euthanized and spinal cords harvested for MMP-2 expression analysis. Result The FA-treated groups showed higher BBB scores during mid phase (day 18) and in late phase (day 42) of injury compared to controls, suggesting enhanced functional recovery. There is a transient decline in TH in animals from the FA-treated group compared to controls when tested on days 18, 21, 28, and 35
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N.Natarajan
2010-10-01
Full Text Available Modeling of solute transport through fractured rock is an important component of in many disciplines especially groundwater contamination and nuclear waste disposal. Several studies have been conducted on single rock fracture using parallel plate model and recently solute and thermal transport has been numerically modeled in the sinusoidal fracture matrix coupled system. The effect of linear sorption has been studied on the same. Results suggest the high matrix porosity and matrix diffusion coefficient enhance the sorption process and reduce the matrix diffusion of solutes. The velocity of the fluid reduces with increment in fracture aperture.
Space Vector Modulation Based Direct Matrix Converter for Stand-Alone system
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Chandra Sekhar Ajin Sekhar
2014-02-01
Full Text Available In this paper Permanent Magnet Synchronous Generator (PMSG is used for wind power generation in standalone system due to their feature of high efficiency and low maintenance cost, which was fed with smart direct matrix converter for direct AC-AC conversion, It provides sinusoidal output waveforms with minimal higher order harmonics and no sub harmonics and also it eliminate the usage of dc-link and other passive elements. Space vector modulation (SVM controlled technique is used for matrix converter switching which can eliminate the switching loses by selected switching states.Proposed work are often seen as a future concept for variable speed drives technology.The proposed model for RL load was analysed and verified by varying the resistor and inductance value and analysed using MATLAB simulation.
Numerical control matrix rotation for the LINC-NIRVANA multiconjugate adaptive optics system
Arcidiacono, Carmelo; Bertram, Thomas; Ragazzoni, Roberto; Farinato, Jacopo; Esposito, Simone; Riccardi, Armando; Pinna, Enrico; Puglisi, Alfio; Fini, Luca; Xompero, Marco; Busoni, Lorenzo; Quiros-Pacheco, Fernando; Briguglio, Runa
2010-07-01
LINC-NIRVANA will realize the interferometric imaging focal station of the Large Binocular Telescope. A double Layer Oriented multi-conjugate adaptive optics system assists the two arms of the interferometer, supplying high order wave-front correction. In order to counterbalance the field rotation, mechanical derotation for the two ground wave-front sensors, and optical derotators for the mid-high layers sensors fix the positions of the focal planes with respect to the pyramids aboard the wave-front sensors. The derotation introduces pupil images rotation on the wavefront sensors: the projection of the deformable mirrors on the sensor consequently change. The proper adjustment of the control matrix will be applied in real-time through numerical computation of the new matrix. In this paper we investigate the temporal and computational aspects related to the pupils rotation, explicitly computing the wave-front errors that may be generated.
A New Agile Radiating System Called Electromagnetic Band Gap Matrix Antenna
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Hussein Abou Taam
2014-01-01
Full Text Available Civil and military applications are increasingly in need for agile antenna devices which respond to wireless telecommunications, radars, and electronic warfare requirements. The objective of this paper is to design a new agile antenna system called electromagnetic band gap (EBG matrix. The working principle of this antenna is based on the radiating aperture theory and constitutes the subject of an accepted CNRS patent. In order to highlight the interest and the originality of this antenna, we present a comparison between it and a classical patch array only for the (one-dimensional 1D configuration by using a rigorous full wave simulation (CST Microwave software. In addition, EBG matrix antenna can be controlled by specific synthesis algorithms. These algorithms use inside their; optimization loop an analysis procedure to evaluate the radiation pattern. The analysis procedure is described and validated at the end of this paper.
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Thaiz Cristina Wypych
2011-10-01
Full Text Available The aim of this work was to study the development and evaluation of a hydrolphilic matrix as a buccoadhesive system containing diclofenac sodium. Eleven formulations were prepared containing the following bioadhesive polymers: hydroxylpropylmethylcellulose, polycarbophil, guar gum and xanthan gum individually and in combination. All the formulations were evaluated for the swelling index, adhesive index, and the time of adhesive and drug release profile (%. The results showed that the formulations that presented the most swelling index were the F3 (PAA/GX and F6 (GG/GX. The smaller index swelling was for F1 (PAA/CM and F10 (HPCMC/CM. The F4 (PAA/HPMC formulation presented the best adhesive index and F10 (HPMC/CM the worst. F1 (PAA/CM was the best matrix hydrophilic adhesive for controlled release. The hydroxylpropylmethylcellulose, guar and xanthan gum when used individually presented low adhesiveness.
Institute of Scientific and Technical Information of China (English)
刘保国; 殷学纲; 蹇开林; 吴永
2003-01-01
A general method based on Riccati transfer matrix is presented to calculate the2 nd order perturbations of eigendatas for one-dimensional structural system with parameteruncertainties. The method is applicable to both real and complex eigendatas of any one-dimensional structural system. The formulas for calculating the sensitivity derivatives ofeigendatas based on this method are also presented. The method is applied to theperturbation analysis for the eigendatas of a rotor with gyroscopic moment, and thedifferences between the perturbation results and the accurate calculating results are small.
Cal, Krzysztof; Sznitowska, Malgorzata; Janicki, Stanislaw
2008-10-01
Drug-in-adhesive matrix-type transdermal therapeutic systems for indomethacin (IND) were formulated and evaluated. Silicone and two types of polyacrylates were used as the bases of matrices. Terpinolene was used as a penetration enhancer. The physicochemical properties of matrices were determined. The bioavailability study of IND was performed in rats. The presence of IND in blood was demonstrated for each system. The calculated pharmacokinetics parameters for IND mainly depend on the solubility of IND in the adhesive layer. The positive influence of a penetration enhancer on IND bioavailability was observed only for one type of polyacrylate matrices.
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Zhenya Gao
Full Text Available All-trans retinoic acid (ATRA plays an important role in ocular development. Previous studies found that retinoic acid could influence the metabolism of scleral remodeling by promoting retinal pigment epithelium (RPE cells to secrete secondary signaling factors. The purpose of this study was to investigate whether retinoic acid affected secretion of bone morphogenetic protein 2 (BMP-2 and matrix metalloproteinase 2 (MMP-2 and to explore the signaling pathway of retinoic acid in cultured acute retinal pigment epithelial 19 (ARPE-19 cells.The effects of ATRA (concentrations from 10-9 to 10-5 mol/l on the expression of retinoic acid receptors (RARs in ARPE-19 cells were examined at the mRNA and protein levels using reverse transcription-polymerase chain reaction (RT-PCR and western blot assay, respectively. The effects of treating ARPE-19 cells with ATRA concentrations ranging from 10-9 to 10-5 mol/l for 24 h and 48 h or with 10-6mol/l ATRA at different times ranging from 6h to 72h were assessed using real-time quantitative PCR (qPCR and enzyme-linked immunosorbent assay (ELISA. The contribution of RARβ-induced activation of ARPE-19 cells was confirmed using LE135, an antagonist of RARβ.RARβ mRNA levels significantly increased in the ARPE-19 cells treated with ATRA for 24h and 48h. These increases in RARβ mRNA levels were dose dependent (at concentrations of 10-9 to 10-5 mol/l with a maximum effect observed at 10-6 mol/l. There were no significant changes in the mRNA levels of RARα and RARγ. Western blot assay revealed that RARβ protein levels were increased significantly in a time-dependent manner in ARPE-19 cells treated with 10-6 mol/l ATRA from 12 h to 72 h, with a marked increase observed at 24 h and 48 h. The upregulation of RARβ and the ATRA-induced secretion in ARPE-19 cells could be inhibited by the RARβ antagonist LE135.ATRA induced upregulation of RARβ in ARPE-19 cells and stimulated these cells to secrete BMP-2 and MMP-2.
Snorradóttir, Bergthóra S; Jónsdóttir, Fjóla; Sigurdsson, Sven Th; Thorsteinsson, Freygardur; Másson, Már
2013-07-16
Medical devices and polymeric matrix systems that release drugs or other bioactive compounds are of interest for a variety of applications. The release of the drug can be dependent on a number of factors such as the solubility, diffusivity, dissolution rate and distribution of the solid drug in the matrix. Achieving the goal of an optimal release profile can be challenging when relying solely on traditional experimental work. Accurate modelling complementing experimentation is therefore desirable. Numerical modelling is increasingly becoming an integral part of research and development due to the significant advances in computer simulation technology. This work focuses on numerical modelling and investigation of multi-layered silicone matrix systems. A numerical model that can be used to model multi-layered systems was constructed and validated by comparison with experimental data. The model could account for the limited dissolution rate and effect of the drug distribution on the release profiles. Parametric study showed how different factors affect the characteristics of drug release. Multi-layered medical silicone matrices were prepared in special moulds, where the quantity of drug in each layer could be varied, and release was investigated with Franz-diffusion cell setup. Data for long-term release was fitted to the model and the full depletion of the system predicted. The numerical model constructed for this study, whose input parameters are the diffusion, effective dissolution rate and dimensional solubility coefficients, does not require any type of steady-state approximation. These results indicate that numerical model can be used as a design tool for development of controlled release systems such as drug-loaded medical devices.
Jankiewicz, Justyna
2004-01-01
We study the properties of time evolution of the $K^{0}-\\bar{K}^{0} $ system in spectral formulation. Within the one--pole model we find the exact form of the diagonal matrix elements of the effective Hamiltonian for this system. It appears that, contrary to the Lee--Oehme--Yang (LOY) result, these exact diagonal matrix elements are different if the total system is CPT--invariant but CP--noninvariant.
Evaluation of the thermodynamics of a four level system using canonical density matrix method
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Awoga Oladunjoye A.
2013-02-01
Full Text Available We consider a four-level system with two subsystems coupled by weak interaction. The system is in thermal equilibrium. The thermodynamics of the system, namely internal energy, free energy, entropy and heat capacity, are evaluated using the canonical density matrix by two methods. First by Kronecker product method and later by treating the subsystems separately and then adding the evaluated thermodynamic properties of each subsystem. It is discovered that both methods yield the same result, the results obey the laws of thermodynamics and are the same as earlier obtained results. The results also show that each level of the subsystems introduces a new degree of freedom and increases the entropy of the entire system. We also found that the four-level system predicts a linear relationship between heat capacity and temperature at very low temperatures just as in metals. Our numerical results show the same trend.
Grid Connected Wind Energy Conversion System Using Three Phase Matrix Converter
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R.A. Priya
2015-01-01
Full Text Available A variable speed Wind Energy Conversion System (WECS with Permanent Magnet Synchronous Generator (PMSG connected to grid through Matrix Converter (MC is proposed in this study. Necessity for increased demand in electrical energy paved way for use of renewable energy sources, one of which is abundant wind energy available in ample. Various Wind Energy Conversion systems have been proposed over the decades, of which various topologies had been projected, where complex topologies are being in existence. Permanent magnet synchronous generator has substantial advantages over conventional generators like less weight and volume and exemption for separate excitation with high precision. The conventional system involves two stage of conversion involving rectification followed by inversion being coupled by a DC link capacitor before fed to a grid, which decreases the efficiency of the system due to power quality issue. To overcome this matrix converter can be utilized to transfer the power from generation stage to the grid; there by an AC-AC converter can transfer power from generator to the grid. The proposed system is designed and tested in MATALB/Simulink environment and the results are effective.
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Razvigorova, M.; Budinova, T.; Tsyntsarski, B.; Petrova, B. [Bulgarian Academy of Sciences, Institute of Organic Chemistry, 1113 Sofia, Acad. Bonchev Str., bl. 9 (Bulgaria); Ekinci, E. [ISIK University, Kumbaba Mevkii, 34980 Istanbul (Turkey); Atakul, H. [Istanbul Technical University, Department of Chemical Engineering, Maslak, 34469 Istanbul (Turkey)
2008-11-03
In order to obtain more information and to understand the nature of relation between organic and mineral matter in oil shales, the compositions of soluble bitumen fractions obtained by extraction from Bulgarian oil shales before and after demineralization with 10% HCl, concentrated HF, and a HF/HCl mixture were investigated. The four extracts were quantitatively examined by IR and {sup 1}H NMR spectroscopy. The investigation of isolated acidic material of the bitumen fractions showed that the fatty acids are present in bitumen fractions as free acids, esters and salts. The amount of free acids in bitumen is very small. The dominant part of bitumen acids is associated with mineral components of the oil shales as well as part of them is included in the mineral matrix, and can be separated only after deep demineralization. The kerogen of the oil shales, obtained after separation of the bitumen fractions and mineral components, was subjected to saponification in order to determine the amount of acids, bound as esters to the kerogen matrix. The major components found were n-carboxylic, {alpha},{omega}-di-carboxylic, and aromatic acids. The connection of kerogen with mineral components is accomplished by the participation of carboxylic and complicated ester bonds. Experimental data for the composition of bitumen acids give evidence that algae and terrestrial materials are initial sources in the formation of soluble organic matter of Bulgarian oil shale. (author)
Tirrito, Emanuele; Ran, Shi-Ju
2016-01-01
We demonstrate an efficient method that allows for simultaneous determination of the ground state, low energy excitation properties and excitation gap in quantum many body systems. To this aim we first use the \\textit{ab-initio} optimization principle of tensor networks (TN), to show that the infinite density matrix renormalization group (iDMRG) in the real space is associated in a natural manner to the infinite time-evolving block decimation (iTEBD) implemented on a continuous matrix product state (MPS), and defined in imaginary time. We illustrate this association showing that the (imaginary) time matrix product state (MPS) in iTEBD reproduces accurately the properties of the two-dimensional (2D) classical Ising model, verifying in this way that the time MPS corresponds to a well-defined physical state. We apply then our scheme to the one-dimensional (1D) quantum Ising chain, where the time MPS is defined in continuous imaginary time. It is found that the time MPS at or close to the critical point is always...
Yanto, Dede Heri Yuli; Zahara, Syifa; Laksana, Raden Permana Budi; Anita, Sita Heris; Oktaviani, Maulida; Sari, Fahriya Puspita
2017-01-01
An immobilization technique using polyvinyl alcohol (PVA) crosslinked with sodium alginate as a matrix has been developed for textile dyes decolorization. Textiles use dye as an addition to the aesthetic value of the product. Dyes are generally used is a textile dye where the waste will be released directly into the waters around 2-20%. Therefore, it is important to develop an enzyme immobilization method using PVA-Alginate as a matrix. Based on the results of the study showed that the PVA-Alginate beads produced high decolorization percent compared to beads which contains only Ca-alginate alone and formula matrix is optimum at PVA 6% and alginate 1.5%. Encapsulation with boric acid at 7% showed optimum decolorization and reduction for enzyme leakage during decolorization. This study suggested that immobilization of enzymes into PVA-alginate matrix might be used as a biodecolorating agent.
Current-induced forces in mesoscopic systems: A scattering-matrix approach
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Niels Bode
2012-02-01
Full Text Available Nanoelectromechanical systems are characterized by an intimate connection between electronic and mechanical degrees of freedom. Due to the nanoscopic scale, current flowing through the system noticeably impacts upons the vibrational dynamics of the device, complementing the effect of the vibrational modes on the electronic dynamics. We employ the scattering-matrix approach to quantum transport in order to develop a unified theory of nanoelectromechanical systems out of equilibrium. For a slow mechanical mode the current can be obtained from the Landauer–Büttiker formula in the strictly adiabatic limit. The leading correction to the adiabatic limit reduces to Brouwer’s formula for the current of a quantum pump in the absence of a bias voltage. The principal results of the present paper are the scattering-matrix expressions for the current-induced forces acting on the mechanical degrees of freedom. These forces control the Langevin dynamics of the mechanical modes. Specifically, we derive expressions for the (typically nonconservative mean force, for the (possibly negative damping force, an effective “Lorentz” force that exists even for time-reversal-invariant systems, and the fluctuating Langevin force originating from Nyquist and shot noise of the current flow. We apply our general formalism to several simple models that illustrate the peculiar nature of the current-induced forces. Specifically, we find that in out-of-equilibrium situations the current-induced forces can destabilize the mechanical vibrations and cause limit-cycle dynamics.
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Yao, Y. X. [Ames Lab., Ames, IA (United States); Liu, Jun [Ames Lab., Ames, IA (United States); Wang, Cai-Zhuang [Ames Lab., Ames, IA (United States); Ho, Kai-Ming [Ames Lab., Ames, IA (United States)
2014-01-23
We generalized the commonly used Gutzwiller approximation for calculating the electronic structure and total energy of strongly correlated electron systems. In our method, the evaluation of one-body and two-body density matrix elements of the Hamiltonian is simplified using a renormalization approximation to achieve better scaling of the computational effort as a function of system size. To achieve a clear presentation of the concept and methodology, we describe the detailed formalism for a finite hydrogen system with minimal basis set. We applied the correlation matrix renormalization approximation approach to a H_{2} dimer and H_{8} cubic fragment with minimal basis sets, as well as a H_{2} molecule with a large basis set. The results compare favorably with sophisticated quantum chemical calculations. We believe our approach can serve as an alternative way to build up the exchange-correlation energy functional for an improved density functional theory description of systems with strong electron correlations.
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D.F. Schwanzer
2011-09-01
Full Text Available We have investigated the effect of a disordered porous matrix on the cluster microphase formation of a two dimensional system where particles interact via competing interactions. To this end we have performed extensive Monte Carlo simulations and have systematically varied the densities of the fluid and of the matrix as well as the interaction between the matrix particles and between the matrix and fluid particles. Our results provide evidence that the matrix {it does} have a distinct effect on the microphase formation of the fluid particles: as long as the particles interact both among themselves as well as with the fluid particles via a simple hard sphere potential, they essentially reduce the available space, in which the fluid particles form a cluster microphase. On the other hand, if we turn on a long-range tail in the matrix-matrix and in the matrix-fluid interactions, the matrix particles become nucleation centers for the clusters formed by the fluid particles.
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R.R. Joshi
2007-06-01
Full Text Available A systematic controller design and implementation for a matrix-converter-based induction motor drive system is proposed. A nonlinear adaptive backstepping controller is proposed to improve the speed and position responses of the induction motor system. By using the proposed adaptive backstepping controller, the system can track a time-varying speed command and a time-varying position command well. Moreover, the system has a good load disturbance rejection capability. The realization of the controller is very simple. All of the control loops, including the current loop, speed loop and position loop, are implemented by a digital signal processor. Several experimental results are given to validate the theoretical analysis.
A Charrelation Matrix-Based Blind Adaptive Detector for DS-CDMA Systems.
Luo, Zhongqiang; Zhu, Lidong
2015-08-14
In this paper, a blind adaptive detector is proposed for blind separation of user signals and blind estimation of spreading sequences in DS-CDMA systems. The blind separation scheme exploits a charrelation matrix for simple computation and effective extraction of information from observation signal samples. The system model of DS-CDMA signals is modeled as a blind separation framework. The unknown user information and spreading sequence of DS-CDMA systems can be estimated only from the sampled observation signals. Theoretical analysis and simulation results show that the improved performance of the proposed algorithm in comparison with the existing conventional algorithms used in DS-CDMA systems. Especially, the proposed scheme is suitable for when the number of observation samples is less and the signal to noise ratio (SNR) is low.
Classical R-matrix theory for bi-Hamiltonian field systems
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Blaszak, Maciej [Department of Physics, Adam Mickiewicz University, Umultowska 85, 61-614 Poznan (Poland); Szablikowski, Blazej M [Department of Mathematics, University of Glasgow, Glasgow G12 8QW (United Kingdom)], E-mail: blaszakm@amu.edu.pl, E-mail: b.szablikowski@maths.gla.ac.uk
2009-10-09
This is a survey of the application of the classical R-matrix formalism to the construction of infinite-dimensional integrable Hamiltonian field systems. The main point is the study of bi-Hamiltonian structures. Appropriate constructions on Poisson, noncommutative and loop algebras as well as the central extension procedure are presented. The theory is developed for (1 + 1)- and (2 + 1)-dimensional field and lattice soliton systems as well as hydrodynamic systems. The formalism presented contains sufficiently many proofs and important details to make it self-contained and complete. The general theory is applied to several infinite-dimensional Lie algebras in order to construct both dispersionless and dispersive (soliton) integrable field systems.
Directory of Open Access Journals (Sweden)
Majeed Ullah
2015-01-01
Full Text Available The aim of current study was to explore the influence of three commonly used polymers, that is, cellulosics and noncellulosics, for example, Methocel K4M, Kollidon VA/64, and Soluplus, on the phase disproportionation and drug release profile of carbamazepine-succinic acid (CBZ-SUC cocrystal at varying drug to polymer ratios (1 : 1 to 1 : 0.25 in matrix tablets. The polymorphic phase disproportionation during in-depth dissolution studies of CBZ-SUC cocrystals and its crystalline properties were scrutinized by X-ray powder diffractrometry and Raman spectroscopy. The percent drug release from HPMC formulations (CSH showed inverse relation with the concentration of polymer; that is, drug release increased with decrease in polymer concentration. On contrary, direct relation was observed between percent drug release and polymer concentrations of Kollidon VA 64/Soluplus (CSK, CSS. At similar polymer concentration, drug release from pure carbamazepine was slightly lower with HPMC formulations than that of cocrystal; however, opposite trend in release rate was observed with Kollidon VA/64 and Soluplus. The significant increase in dissolution rate of cocrystal occurred with Kollidon VA/64 and Soluplus at higher polymer concentration. Moreover, no phase change took place in Methocel and Kollidon formulations. No tablet residue was left for Soluplus formulation so the impact of polymer on cocrystal integrity cannot be predicted.
Deegan, Daniel B; Zimmerman, Cynthia; Skardal, Aleksander; Atala, Anthony; Shupe, Thomas D
2015-03-01
Tissue engineering and cell based liver therapies have utilized primary hepatocytes with limited success due to the failure of hepatocytes to maintain their phenotype in vitro. In order to overcome this challenge, hyaluronic acid (HA) cell culture substrates were formulated to closely mimic the composition and stiffness of the normal liver cellular microenvironment. The stiffness of the substrate was modulated by adjusting HA hydrogel crosslinking. Additionally, the repertoire of bioactive molecules within the HA substrate was bolstered by supplementation with normal liver extracellular matrix (ECM). Primary human hepatocyte viability and phenotype were determined over a narrow physiologically relevant range of substrate stiffnesses from 600 to 4600Pa in both the presence and absence of liver ECM. Cell attachment, viability, and organization of the actin cytoskeleton improved with increased stiffness up to 4600Pa. These differences were not evident in earlier time points or substrates containing only HA. However, gene expression for the hepatocyte markers hepatocyte nuclear factor 4 alpha (HNF4α) and albumin significantly decreased on the 4600Pa stiffness at day 7 indicating that cells may not have maintained their phenotype long-term at this stiffness. Function, as measured by albumin secretion, varied with both stiffness and time in culture and peaked at day 7 at the 1200Pa stiffness, slightly below the stiffness of normal liver ECM at 3000Pa. Overall, gel stiffness affected primary human hepatocyte cell adhesion, functional marker expression, and morphological characteristics dependent on both the presence of liver ECM in gel substrates and time in culture.
Schwerdtfeger, Christine A; Mazziotti, David A
2011-11-03
Parametrization of the 2-electron reduced density matrix (2-RDM) rather than the many-electron wave function yields a new family of electronic-structure methods that are faster and more accurate than traditional coupled electron-pair methods including coupled cluster with single and double excitations. Deriving the parametrization from N-representability conditions generates a 2-RDM that captures significant correlation from triple and higher-order excitations at the cost of double excitations. We apply the parametric 2-RDM method to confirm recent experiments determining the relative thermodynamic populations of the cis-cis and cis-trans isomers of carbonic acid. In 2010 Bernard et al. showed by infrared spectroscopy that the populations of cis-cis and cis-trans isomers have a 10:1 ratio at 210 K. By use of the parametric 2-RDM method, we predict a 8:1 ratio at 210 K. Comparable ab initio methods overestimate the stability of the cis-cis isomer with 24:1 and 21:1 ratios. These 2-RDM-based methods promise to have significant applications throughout chemistry.
(Anti-)Hermitian Generalized (Anti-)Hamiltonian Solution to a System of Matrix Equations
Juan Yu; Qing-Wen Wang; Chang-Zhou Dong
2014-01-01
We mainly solve three problems. Firstly, by the decomposition of the (anti-)Hermitian generalized (anti-)Hamiltonian matrices, the necessary and sufficient conditions for the existence of and the expression for the (anti-)Hermitian generalized (anti-)Hamiltonian solutions to the system of matrix equations AX=B,XC=D are derived, respectively. Secondly, the optimal approximation solution minX∈K∥X^-X∥ is obtained, where K is the (anti-)Hermitian generalized (anti-)Hamiltonian solution set of t...
Superstatistical random-matrix-theory approach to transition intensities in mixed systems.
Abul-Magd, A Y
2006-05-01
We study the fluctuation properties of transition intensities applying a recently proposed generalization of the random matrix theory, which is based on Beck and Cohen's superstatistics. We obtain an analytic expression for the distribution of the reduced transition probabilities that applies to systems undergoing a transition out of chaos. The obtained distribution fits the results of a previous nuclear shell model calculations for some electromagnetic transitions that deviate from the Porter-Thomas distribution. It agrees with the experimental reduced transition probabilities for the nucleus better than the commonly used chi(2) distribution.
THE PERFORMANCE OF A NUCLEAR FUEL-MATRIX MATERIAL IN A SEALED CO2 SYSTEM
Turner, Joel David
2012-01-01
An advanced concept high temperature reactor (HTR) design has been proposed - The ‘U-Battery’, which utilises a unique sealed coolant loop, and is intended to operate with minimal human oversight. In order to reduce the need for moving parts within the design, CO2 has been selected as a candidate coolant, potentially allowing a naturally circulated system.HTR fuel is held within a semi-graphitic fuel-matrix material, and this has not previously been tested within a CO2 environment. Graphite i...
Hamiltonian Systems and Darboux Transformation Associated with a 3 × 3 Matrix Spectral Problem
Institute of Scientific and Technical Information of China (English)
无
2007-01-01
Starting from a 3 × 3 matrix spectral problem, we derive a hierarchy of nonlinear equations. It is shown that the hierarchy possesses bi-Hamiltonian structure. Under the symmetry constraints between the potentials and the eigenfunctions, Lax pair and adjoint Lax pairs including partial part and temporal part are nonlinearied into two finitedimensional Hamiltonian systems (FDHS) in Liouville sense. Moreover, an explicit N-fold Darboux transformation for CDNS equation is constructed with the help of a gauge transformation of the spectral problem.
Directory of Open Access Journals (Sweden)
M.A. Pires-Neto
1999-05-01
Full Text Available Axon growth and guidance represent complex biological processes in which probably intervene diverse sets of molecular cues that allow for the appropriate wiring of the central nervous system (CNS. The extracellular matrix (ECM represents a major contributor of molecular signals either diffusible or membrane-bound that may regulate different stages of neural development. Some of the brain ECM molecules form tridimensional structures (tunnels and boundaries that appear during time- and space-regulated events, possibly playing relevant roles in the control of axon elongation and pathfinding. This short review focuses mainly on the recognized roles played by proteoglycans, laminin, fibronectin and tenascin in axonal development during ontogenesis.
Genetics of the proteolytic system of lactic acid bacteria
Kok, Jan
1990-01-01
The proteolytic system of lactic acid bacteria is of eminent importance for the rapid growth of these organisms in protein-rich media. The combined action of proteinases and peptidases provides the cell with small peptides and essential amino acids. The amino acids and peptides thus liberated have t
Genetics of the proteolytic system of lactic acid bacteria
Kok, Jan
1990-01-01
The proteolytic system of lactic acid bacteria is of eminent importance for the rapid growth of these organisms in protein-rich media. The combined action of proteinases and peptidases provides the cell with small peptides and essential amino acids. The amino acids and peptides thus liberated have
Institute of Scientific and Technical Information of China (English)
2007-01-01
A vector radiative transfer numerical model of the coupled ocean-atmosphere system is developed based on the matrix-operator method, which is named PCOART. Using the Fourier analysis, the vector radiative transfer equation (VRTE) is separated into a set of equations depending only on the observa-tion zenith angle. Using the Gaussian-Quadrature method, VRTE is finally transferred into the matrix equation solved by the adding-doubling method. According to the reflective and refractive properties of the ocean-atmosphere interface, the vector radiative transfer numerical model of the ocean and at-mosphere is coupled in PCOART. Compared with the exact Rayleigh scattering look-up tables of MODIS (Moderate-resolution Imaging Spectroradiometer), it is shown that PCOART is an exactly numerical model, and the processing methods of the multi-scattering and polarization are correct. Also, validated with the standard problems of the radiative transfer in water, it is shown that PCOART can be used to calculate the underwater radiative transfer problems. Therefore, PCOART is a useful tool for exactly calculating the vector radiative transfer of the coupled ocean-atmosphere system, which can be used to study the polarization properties of the radiance in the whole ocean-atmosphere system and the remote sensing of the atmosphere and ocean.
Institute of Scientific and Technical Information of China (English)
HE XianQiang; PAN DeLu; BAI Yan; ZHU QianKun; GONG Fang
2007-01-01
A vector radiative transfer numerical model of the coupled ocean-atmosphere system is developed based on the matrix-operator method,which is named PCOART.Using the Fourier analysis,the vector radiative transfer equation (VRTE) is separated into a set of equations depending only on the observation zenith angle.Using the Gaussian-Quadrature method,VRTE is finally transferred into the matrix equation solved by the adding-doubling method.According to the reflective and refractive properties of the ocean-atmosphere interface,the vector radiative transfer numerical model of the ocean and atmosphere is coupled in PCOART.Compared with the exact Rayleigh scattering look-up tables of MODIS (Moderate-resolution Imaging Spectroradiometer),it is shown that PCOART is an exactly numerical model,and the processing methods of the multi-scattering and polarization are correct.Also,validated with the standard problems of the radiative transfer in water,it is shown that PCOART can be used to calculate the underwater radiative transfer problems.Therefore,PCOART is a useful tool for exactly calculating the vector radiative transfer of the coupled ocean-atmosphere system,which can be used to study the polarization properties of the radiance in the whole ocean-atmosphere system and the remote sensing of the atmosphere and ocean.
Extracellular matrix-inspired growth factor delivery systems for bone regeneration
Energy Technology Data Exchange (ETDEWEB)
Martino, Mikaël M. [Osaka Univ. (Japan). Immunology Frontier Research Center; Briquez, Priscilla S. [Ecole Polytechnique Federale de Lausanne (Switzerland). Inst. of Bioengineering; Maruyama, Kenta [Osaka Univ. (Japan). Immunology Frontier Research Center; Hubbell, Jeffrey A. [Ecole Polytechnique Federale de Lausanne (Switzerland). Inst. of Bioengineering; Univ. of Chicago, IL (United States). Inst. for Molecular Engineering; Argonne National Lab. (ANL), Argonne, IL (United States)
2015-04-17
Growth factors are very promising molecules to enhance bone regeneration. However, their translation to clinical use has been seriously limited, facing issues related to safety and cost-effectiveness. These problems derive from the vastly supra-physiological doses of growth factor used without optimized delivery systems. Therefore, these issues have motivated the development of new delivery systems allowing better control of the spatio-temporal release and signaling of growth factors. Because the extracellular matrix (ECM) naturally plays a fundamental role in coordinating growth factor activity in vivo, a number of novel delivery systems have been inspired by the growth factor regulatory function of the ECM. After introducing the role of growth factors during the bone regeneration process, this review exposes different issues that growth factor-based therapies have encountered in the clinic and highlights recent delivery approaches based on the natural interaction between growth factor and the ECM.
Institute of Scientific and Technical Information of China (English)
Wu Yunli; Li Zhibin; Duan Guangren
2006-01-01
A simple parametric approach to design a full-order observer for matrix second-order linear systems with uncertain disturbance input in the matrixsecond-order framework is proposed. The basic idea is to minimize the H2 norm of the transfer function from disturbance to estimation error using the design degrees of freedom provided by a parametric approach in the observer design. Besides the design parameters, the eigenvalues of the closed-loop system are also optimized within desired regions on the left-half of the complex plane. Using the proposed approach, additional specifications can be easily achieved. A spring-mass system is using to show the effect of the proposed approaches.
Caballero, B; Cuevas, J C
2012-01-01
We present here a generalization of the scattering-matrix approach for the description of the propagation of electromagnetic waves in nanostructured magneto-optical systems. Our formalism allows us to describe all the key magneto-optical effects in any configuration in periodically patterned multilayer structures. The method can also be applied to describe periodic multilayer systems comprising materials with any type of optical anisotropy. We illustrate the method with the analysis of a recent experiment in which the transverse magneto-optical Kerr effect was measured in a Fe film with a periodic array of subwavelength circular holes. We show, in agreement with the experiments, that the excitation of surface plasmon polaritons in this system leads to a resonant enhancement of the transverse magneto-optical Kerr effect.
Performance analysis of cross-seeding WDM-PON system using transfer matrix method
Simatupang, Joni Welman; Pukhrambam, Puspa Devi; Huang, Yen-Ru
2016-12-01
In this paper, a model based on the transfer matrix method is adopted to analyze the effects of Rayleigh backscattering and Fresnel multiple reflections on a cross-seeding WDM-PON system. As part of analytical approximation methods, this time-independent model is quite simple but very efficient when it is applied to various WDM-PON transmission systems, including the cross-seeding scheme. The cross seeding scheme is most beneficial for systems with low loop-back ONU gain or low reflection loss at the drop fiber for upstream data in bidirectional transmission. However for downstream data transmission, multiple reflections power could destroy the usefulness of the cross-seeding scheme when the reflectivity is high enough and the RN is positioned near OLT or close to ONU.
Munekata, P E S; Domínguez, R; Franco, D; Bermúdez, R; Trindade, M A; Lorenzo, Jose M
2017-02-01
The effect of natural antioxidants on physicochemical properties, lipid and protein oxidation, volatile compounds and free fatty acids (FFA) were determined in Spanish salchichón enriched with n-3 fatty acids encapsulated and stabilized in konjac matrix. Phenolic compounds of beer residue extract (BRE), chestnut leaves extract (CLE) and peanut skin extract (PSE) were also identified and quantified. Five batches of salchichón were prepared: control (CON, without antioxidants), butylated hydroxytoluene (BHT), BRE, CLE and PSE. The main phenolic compounds were catechin and benzoic acid for BRE, gallic acid and catechin for CLE and catechin and protocatechuic acid for PSE. Statistical analysis did not show significant differences on chemical composition among treatments. Reductions in luminosity (Pantioxidants. Finally, the inclusion of antioxidants (P<0.001) decreased the hexanal content, whereas the FFA content increased by the addition of natural extracts. Copyright Â© 2016 Elsevier Ltd. All rights reserved.
Indian Academy of Sciences (India)
N Deo
2002-02-01
This paper summarizes some work that I have been doing on eigenvalue correlators of random matrix models which show some interesting behavior. First we consider matrix models with gaps in their spectrum or density of eigenvalues. The density–density correlators of these models depend on whether , where is the size of the matrix, takes even or odd values. The fact that this dependence persists in the large thermodynamic limit is an unusual property and may have consequences in the study of one electron effects in mesoscopic systems. Secondly, we study the parametric and cross correlators of the Harish Chandra–Itzykson–Zuber matrix model. The analytic expressions determine how the correlators change as a parameter (e.g. the strength of a perturbation in the Hamiltonian of the chaotic system or external magnetic ﬁeld on a sample of material) is varied. The results are relevant for the conductance ﬂuctuations in disordered mesoscopic systems.
Energy Technology Data Exchange (ETDEWEB)
Ecklebe, Andreas
2009-05-22
The publication discusses a three- to two-phase matrix converter for contactless power transmission systems. Based on relevant publications, possible resonance setups for contactless power transmission systems are investigated to begin with. An analysis of relevant parameters shows the differences between the various setups, but it also shows that for an investigation focusing on the feeding converter, simple modelling of the three investigated resonance setups is possible with the aid of a serial oscillating circuit. In consequence, it should be possible to apply the results also to the matrix converter with other serially resonant loads. The second part of the investigation focuses on the matrix converter. After a theoretical description, a combination von high-frequency control - e.g. bulk pulsing - and low-frequency pulsing patterns for setting the harmonics level of the grid currents is presented. The similarity to a conventional H bridge circuit enables an assessment of commutation and the identification of the necessary inverter states. These are characterized in that a bidirectional connection between the input system and each output phase is available at any time. The functioning of the commutation and of the inverter as a whole is proved by simulation in a first step, in which also the dynamic switching characteristics of the power semiconductors is taken into account. Finally, the results of laboratory measurements are presented and compared with the theoretical results. The laboratory setup consists of the power section of the matrix converter with input filters and modular gate drivers, a DSP/FPGA control system, and a contactless power transmission system with a current inverter and load on the secondary side. The investigation thus provides information on the use of the three-to-two phase matrix converter as an interesting alternative for feeding of contactless power transmission systems and other serially resonant loads. (orig.) [German] Diese
Energy Technology Data Exchange (ETDEWEB)
Ecklebe, Andreas
2009-05-22
The publication discusses a three- to two-phase matrix converter for contactless power transmission systems. Based on relevant publications, possible resonance setups for contactless power transmission systems are investigated to begin with. An analysis of relevant parameters shows the differences between the various setups, but it also shows that for an investigation focusing on the feeding converter, simple modelling of the three investigated resonance setups is possible with the aid of a serial oscillating circuit. In consequence, it should be possible to apply the results also to the matrix converter with other serially resonant loads. The second part of the investigation focuses on the matrix converter. After a theoretical description, a combination von high-frequency control - e.g. bulk pulsing - and low-frequency pulsing patterns for setting the harmonics level of the grid currents is presented. The similarity to a conventional H bridge circuit enables an assessment of commutation and the identification of the necessary inverter states. These are characterized in that a bidirectional connection between the input system and each output phase is available at any time. The functioning of the commutation and of the inverter as a whole is proved by simulation in a first step, in which also the dynamic switching characteristics of the power semiconductors is taken into account. Finally, the results of laboratory measurements are presented and compared with the theoretical results. The laboratory setup consists of the power section of the matrix converter with input filters and modular gate drivers, a DSP/FPGA control system, and a contactless power transmission system with a current inverter and load on the secondary side. The investigation thus provides information on the use of the three-to-two phase matrix converter as an interesting alternative for feeding of contactless power transmission systems and other serially resonant loads. (orig.) [German] Diese
Temporal moment analysis of solute transport in a coupled fracture-skin-matrix system
Indian Academy of Sciences (India)
V Renu; G Suresh Kumar
2014-04-01
In the present study, method of temporal moments has been used to analyse the transport characteristics of reactive solute along fracture in a coupled fracture-skin-matrix system. In order to obtain the concentration distribution within the fracture, a system of coupled partial differential equations for fracture, fractureskin and rock-matrix has been solved numerically in a pseudo two-dimensional domain using implicit finite difference method. Subsequently, lower order temporal moments of solute have been computed from the concentration distribution to analyse the transport characteristics of solutes in the fracture. This study has been done by considering an inlet boundary condition of constant continuous source in a single fracture. The effect of various fracture-skin parameters like porosity, thickness and diffusion coefficient on the transport of solutes have been studied by doing sensitivity analyses. The effect of nonlinear sorption and radioactive decay of solutes have also been analysed by carrying out simulations for different sorption intensities and decay constants. Numerical results suggested that the presence of fracture-skin significantly influences the transport characteristics of reactive solutes along the fracture.
Interior Controllability of a 2×2 Reaction-Diffusion System with Cross-Diffusion Matrix
Directory of Open Access Journals (Sweden)
Hugo Leiva
2009-01-01
Full Text Available We prove the interior approximate controllability for the following 2×2 reaction-diffusion system with cross-diffusion matrix ut=aΔu−β(−Δ1/2u+bΔv+1ωf1(t,x in (0,τ×Ω, vt=cΔu−dΔv−β(−Δ1/2v+1ωf2(t,x in (0,τ×Ω, u=v=0, on (0,T×∂Ω, u(0,x=u0(x, v(0,x=v0(x, x∈Ω, where Ω is a bounded domain in ℝN (N≥1, u0,v0∈L2(Ω, the 2×2 diffusion matrix D=[abcd] has semisimple and positive eigenvalues 0<ρ1≤ρ2, β is an arbitrary constant, ω is an open nonempty subset of Ω, 1ω denotes the characteristic function of the set ω, and the distributed controls f1,f2∈L2([0,τ];L2(Ω. Specifically, we prove the following statement: if λ11/2ρ1+β>0 (where λ1 is the first eigenvalue of −Δ, then for all τ>0 and all open nonempty subset ω of Ω the system is approximately controllable on [0,τ].
Institute of Scientific and Technical Information of China (English)
Lyn B. Jakeman; Kent E. Williams; Bryan Brautigam
2014-01-01
Glial cells in the central nervous system (CNS) contribute to formation of the extracellular matrix, which provides adhesive sites, signaling molecules, and a diffusion barrier to enhance efifcient neurotransmission and axon potential propagation. In the normal adult CNS, the extracellular matrix (ECM) is relatively stable except in selected regions characterized by dynamic remodel-ing. However, after trauma such as a spinal cord injury or cortical contusion, the lesion epicenter becomes a focus of acute neuroinlfammation. The activation of the surrounding glial cells leads to a dramatic change in the composition of the ECM at the edges of the lesion, creating a perile-sion environment dominated by growth inhibitory molecules and restoration of the peripheral/central nervous system border. An advantage of this response is to limit the invasion of damaging cells and diffusion of toxic molecules into the spared tissue regions, but this occurs at the cost of inhibiting migration of endogenous repair cells and preventing axonal regrowth. The following review was prepared by reading and discussing over 200 research articles in the ifeld published in PubMed and selecting those with signiifcant impact and/or controversial points. This article highlights structural and functional features of the normal adult CNS ECM and then focuses on the reactions of glial cells and changes in the perilesion border that occur following spinal cord or contusive brain injury. Current research strategies directed at modifying the inhibitory perile-sion microenvironment without eliminating the protective functions of glial cell activation are discussed.
A suppository-base-matrix tablet for time-dependent colon-specific delivery system
Directory of Open Access Journals (Sweden)
Meijuan Zou
2014-09-01
Full Text Available Our research has focused on the main design features and release performances of time-dependent colon-specific (TDCS delivery tablets, which relies on the relative constancy that is observed in the small intestinal transit time of dosage forms. But inflammatory bowel disease（IBD）can affect the transit time, and usually results in watery stool. Compared to the TDCS and wax-matrix TDCS tablet, a promising time-dependent colon-specific delivery system was investigated. In our study, a suppository-base-matrix coated tablet was evaluated. Water soluble suppository-base helps the expansion of tablet, facilitates uniform film dissolution and achives high osmotic pressure. Combining the expansion of carboxymethyl starch sodium (CMS-Na and the moisture absorption of NaCl, the coated TDCS tablet obtained a burst and targeted drug delivery system. A very good correlation between in vitro drug release and in vivo outcome was observed. This TDCS coated tablet provides a promising strategy to control drug release to the desired lower gastrointestinal region.
Directory of Open Access Journals (Sweden)
Gangli Chen
2013-01-01
Full Text Available The dynamic test precision of the strapdown inertial measurement unit (SIMU is the basis of estimating accurate motion of various vehicles such as warships, airplanes, spacecrafts, and missiles. So, it is paid great attention in the above fields to increase the dynamic precision of SIMU by decreasing the vibration of the vehicles acting on the SIMU. In this paper, based on the transfer matrix method for multibody system (MSTMM, the multibody system dynamics model of laser gyro strapdown inertial measurement unit (LGSIMU is developed; the overall transfer equation of the system is deduced automatically. The computational results show that the frequency response function of the LGSIMU got by the proposed method and Newton-Euler method have good agreements. Further, the vibration reduction performance and the attitude error responses under harmonic and random excitations are analyzed. The proposed method provides a powerful technique for studying dynamics of LGSIMU because of using MSTMM and its following features: without the global dynamics equations of the system, high programming, low order of system matrix, and high computational speed.
Thoron-tartaric acid systems for spectrophotometric determination of thorium
Grimaldi, F.S.; Fletcher, M.H.
1956-01-01
Thoron is commonly used for the spectrophotometric determination of thorium. An undesirable feature of its use is its high sensitivity to zirconium. This study describes the use of tartaric acid as a masking reagent for zirconium. Three tartaric acid-thoron systems, developed for the determination of thorium, differ with respect to the concentrations of thoron and tartaric acid. Mesotartaric acid, used in one of the systems, is most effective in masking zirconium. The behavior of rarer elements, usually associated with thorium ores, is determined in two systems, and a dilution method is described for the direct determination of thorium in monazite concentrates.
Energy Technology Data Exchange (ETDEWEB)
Huang, W.; Antonuk, L.E. E-mail: antonuk@umich.edu; Berry, J.; Maolinbay, M.; Martelli, C.; Mody, P.; Nassif, S.; Yeakey, M
1999-07-11
The development of a full-custom electronic acquisition system designed for readout of large-area active matrix flat-panel imaging arrays is reported. The arrays, which comprise two-dimensional matrices of pixels utilizing amorphous silicon thin-film transistors, are themselves under development for a wide variety of X-ray imaging applications. The acquisition system was specifically designed to facilitate detailed, quantitative investigations of the properties of these novel imaging arrays and contains significant enhancements compared to a previously developed acquisition system. These enhancements include pipelined preamplifier circuits to allow faster readout speed, expanded addressing capabilities allowing a maximum of 4096 array data lines, and on-board summing of image frames. The values of many acquisition system parameters, including timings and voltages, may be specified and downloaded from a host computer. Once acquisition is enabled, the system operates asynchronously of its host computer. The system allows image capture in both radiographic mode (corresponding to the capture of individual X-ray images), and fluoroscopic mode (corresponding to the capture of a continual series of X-ray images). A detailed description of the system architecture and the underlying motivations for the design is reported in this paper. (author)
2010-01-01
Background Infarct-induced left ventricular (LV) remodeling is a deleterious consequence after acute myocardial infarction (MI) which may further advance to congestive heart failure. Therefore, new therapeutic strategies to attenuate the effects of LV remodeling are urgently needed. Salvianolic acid B (SalB) from Salviae mitiorrhizae, which has been widely used in China for the treatment of cardiovascular diseases, is a potential candidate for therapeutic intervention of LV remodeling targeting matrix metalloproteinase-9 (MMP-9). Results Molecular modeling and LIGPLOT analysis revealed in silico docking of SalB at the catalytic site of MMP-9. Following this lead, we expressed truncated MMP-9 which contains only the catalytic domain, and used this active protein for in-gel gelatin zymography, enzymatic analysis, and SalB binding by Biacore. Data generated from these assays indicated that SalB functioned as a competitive inhibitor of MMP-9. In our rat model for cardiac remodeling, western blot, echocardiography, hemodynamic measurement and histopathological detection were used to detect the effects and mechanism of SalB on cardio-protection. Our results showed that in MI rat, SalB selectively inhibited MMP-9 activities without affecting MMP-9 expression while no effect of SalB was seen on MMP-2. Moreover, SalB treatment in MI rat could efficiently increase left ventricle wall thickness, improve heart contractility, and decrease heart fibrosis. Conclusions As a competitive inhibitor of MMP-9, SalB presents significant effects on preventing LV structural damage and preserving cardiac function. Further studies to develop SalB and its analogues for their potential for cardioprotection in clinic are warranted. PMID:20735854
Two Level Versus Matrix Converters Performance in Wind Energy Conversion Systems Employing DFIG
Reddy, Gongati Pandu Ranga; Kumar, M. Vijaya
2017-05-01
Wind power capacity has received enormous growth during past decades. With substantial development of wind power, it is expected to provide a fifth of world's electricity by the end of 2030. In wind energy conversion system, the power electronic converters play an important role. This paper presents the two level and matrix converters performance in wind energy conversion system employing Doubly Fed Induction Generator (DFIG). The DFIG is a wound rotor induction generator. Because of the advantages of the DFIG over other generators it is being used for most of the wind applications. This paper also discusses control of converters using the space vector pulse width modulation technique. The MATLAB/SIMULINK ® software is used to study the performance of the converters.
High performance algorithms in the Sparse Matrix Operator Kernel Emissions (SMOKE) modeling system
Energy Technology Data Exchange (ETDEWEB)
Coats, C.J. Jr. [MCNC Environmental Programs, Research Triangle Park, NC (United States)
1996-12-31
As part of MCNC`s Environmental Decision Support System (EDSS) project, the author has constructed the area-source and point source (exclusive of plume rise) emissions model components of a new emissions model--the Sparse Matrix Operator Kernel Emissions (SMOKE) Modeling System using the new paradigm. As of this August 1995 writing, the author is working on a generalized-vertical-coordinate formulation of plume rise (so that the model can be used for multiple AQMs--UAM, ROM, RADM, RAMS, and his own EDSS AQMs), and plan to start work soon on the mobile and biogenic emissions components. The initial prototype takes the same input files as EPS, but has extensions such as time zone support for each source to support regional modeling. For each category of emissions, SMOKE splits into specific components.
An Offline Formulation of MPC for LPV Systems Using Linear Matrix Inequalities
Directory of Open Access Journals (Sweden)
P. Bumroongsri
2014-01-01
Full Text Available An offline model predictive control (MPC algorithm for linear parameter varying (LPV systems is presented. The main contribution is to develop an offline MPC algorithm for LPV systems that can deal with both time-varying scheduling parameter and persistent disturbance. The norm-bounding technique is used to derive an offline MPC algorithm based on the parameter-dependent state feedback control law and the parameter-dependent Lyapunov functions. The online computational time is reduced by solving offline the linear matrix inequality (LMI optimization problems to find the sequences of explicit state feedback control laws. At each sampling instant, a parameter-dependent state feedback control law is computed by linear interpolation between the precomputed state feedback control laws. The algorithm is illustrated with two examples. The results show that robust stability can be ensured in the presence of both time-varying scheduling parameter and persistent disturbance.
Directory of Open Access Journals (Sweden)
Gonczy Stephen T.
2015-01-01
Full Text Available Ceramic matrix composites (CMCs are being designed and developed for engine and exhaust components in commercial aviation, because they offer higher temperature capabilities, weight savings, and improved durability compared to metals. The United States Federal Aviation Administration (FAA issues and enforces regulations and minimum standards covering the safe manufacture, operation, and maintenance of civil aircraft. As new materials, these ceramic composite components will have to meet the certification regulations of the FAA for “airworthiness”. The FAA certification process is defined in the Federal Aviation Regulations (Title 14 of the Code of Federal Regulations, FAA policy statements, orders, advisory circulars, technical standard orders, and FAA airworthiness directives. These regulations and documents provide the fundamental requirements and guidelines for design, testing, manufacture, quality assurance, registration, operation, inspection, maintenance, and repair of aircraft systems and parts. For metallic parts in aircraft, the FAA certification and compliance process is well-established for type and airworthiness certification, using ASTM and SAE standards, the MMPDS data handbook, and FAA advisory circulars. In a similar manner for polymer matrix composites (PMC, the PMC industry and the FAA have jointly developed and are refining parallel guidelines for polymer matrix composites (PMCs, using guidance in FAA circulars and the CMH-17 PMC handbook. These documents discuss design methods and codes, material testing, property data development, life/durability assessment, production processes, QA procedures, inspection methods, operational limits, and repairs for PMCs. For ceramic composites, the FAA and the CMC and aerospace community are working together (primarily through the CMH-17 CMC handbook to define and codify key design, production, and regulatory issues that have to be addressed in the certification of CMC components in
Simplified LCA and matrix methods in identifying the environmental aspects of a product system.
Hur, Tak; Lee, Jiyong; Ryu, Jiyeon; Kwon, Eunsun
2005-05-01
In order to effectively integrate environmental attributes into the product design and development processes, it is crucial to identify the significant environmental aspects related to a product system within a relatively short period of time. In this study, the usefulness of life cycle assessment (LCA) and a matrix method as tools for identifying the key environmental issues of a product system were examined. For this, a simplified LCA (SLCA) method that can be applied to Electrical and Electronic Equipment (EEE) was developed to efficiently identify their significant environmental aspects for eco-design, since a full scale LCA study is usually very detailed, expensive and time-consuming. The environmentally responsible product assessment (ERPA) method, which is one of the matrix methods, was also analyzed. Then, the usefulness of each method in eco-design processes was evaluated and compared using the case studies of the cellular phone and vacuum cleaner systems. It was found that the SLCA and the ERPA methods provided different information but they complemented each other to some extent. The SLCA method generated more information on the inherent environmental characteristics of a product system so that it might be useful for new design/eco-innovation when developing a completely new product or method where environmental considerations play a major role from the beginning. On the other hand, the ERPA method gave more information on the potential for improving a product so that it could be effectively used in eco-redesign which intends to alleviate environmental impacts of an existing product or process.
Relationship between fatty acids and the endocrine and neuroendocrine system.
Bhathena, Sam J
2006-01-01
Significant interactions exist between fatty acids and the endocrine system. Dietary fatty acids alter both hormone and neuropeptide concentrations and also their receptors. In addition, hormones affect the metabolism of fatty acids and the fatty acid composition of tissue lipids. The principal hormones involved in lipid metabolism are insulin, glucagon, catecholamines, cortisol and growth hormone. The concentrations of these hormones are altered in chronic degenerative conditions such as diabetes and cardiovascular disease, which in turn leads to alterations in tissue lipids. Lipogenesis and lipolysis, which modulate fatty acid concentrations in plasma and tissues, are under hormonal control. Neuropeptides are also involved in lipid metabolism in brain and other tissues. Polyunsaturated fatty acids are also precursors for eicosanoids including prostaglandins, leucotrienes, and thromboxanes, which have hormone-like activities. Fatty acids in turn affect the endocrine system. Saturated and trans fatty acids decrease insulin concentration leading to insulin resistance. In contrast, polyunsaturated fatty acids increase plasma insulin concentration and decrease insulin resistance. In humans, omega3 polyunsaturated fatty acids alter the levels of opioid peptides in plasma. Free fatty acids have been reported to inhibit glucagon release. Fatty acids also affect receptors for hormones and neuropeptides.
一矩阵方程组的反射解%Reflexive solution to a system of matrix equations
Institute of Scientific and Technical Information of China (English)
常海霞; 王卿文
2007-01-01
We derive necessary and sufficient conditions for the existence and an expression of the (anti)reflexive solution with respect to the nontrivial generalized reflection matrix P to the system of complex matrix equations AX = B and XC = D.The explicit solutions of the approximation problem minX∈φ‖X- E‖F was given, where E is a given complex matrix and o is it was pointed that some results in a recent paper are special cases of this paper.
The {P,Q,k+1}-Reflexive Solution to System of Matrix Equations AX=C, XB=D
Directory of Open Access Journals (Sweden)
Chang-Zhou Dong
2015-01-01
Full Text Available Let P∈Cm×m and Q∈Cn×n be Hermitian and {k+1}-potent matrices; that is, Pk+1=P=P⁎ and Qk+1=Q=Q⁎, where ·⁎ stands for the conjugate transpose of a matrix. A matrix X∈Cm×n is called {P,Q,k+1}-reflexive (antireflexive if PXQ=X (PXQ=-X. In this paper, the system of matrix equations AX=C and XB=D subject to {P,Q,k+1}-reflexive and antireflexive constraints is studied by converting into two simpler cases: k=1 and k=2. We give the solvability conditions and the general solution to this system; in addition, the least squares solution is derived; finally, the associated optimal approximation problem for a given matrix is considered.
ABOUT THE INFORMATIZATION MANAGING OF THE PRODUCTION SYSTEM BASED ON THE MATRIX MODEL
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Aleksandr V. Romanenko
2016-06-01
Full Text Available Introduction. The problem of formation and information management systems management of manufacturing system businesses is analyzed in the article. Existing schemes of the Russian economy increased demands for its efficiency. Stability integrative model business entity lifecycle requires a search for solutions based on new technologies in the organization and operation of information management systems. Results. On the basis of the analysis of their importance for sustainability of the entity components of its life cycle conclusions are made about the applicability of the matrix model to the production system management. Contradiction in the application of this management model are solved by separating the information on the basis of the state of product and process state. This division contributes to a better organization of the distribution of responsibility between the profit centers and cost centers. As an indicator of the efficiency of profit centers, it is proposed to use the ratio revenue net from the sale of products to the current value of the planned costs of its production. To assess the effectiveness of cost centers used index that is similar to profitability of fixed assets taking into account the cost of resources utilized by each cost center separately. Discussion and Conclusions. We analyze the relationship between goals management of the production system with the role of profit centers and cost centers. The proposed basis of the formation model information ensures the management of the production system, contributing to improve the quality of managerial decisions in implementing the competitive advantages of business entity.
Chaturvedi M.; Molino Y; Sreedhar B; Khrestchatisky M; Kaczmarek L
2014-01-01
Mayank Chaturvedi,1 Yves Molino,2 Bojja Sreedhar,3 Michel Khrestchatisky,4 Leszek Kaczmarek1 1Laboratory of Neurobiology, Nencki Institute, Warsaw, Poland; 2Vect-Horus, Marseille, France; 3Indian Institute of Chemical Technology, Hyderabad, India; 4Aix-Marseille Université, CNRS, NICN, UMR7259, Marseille, France Aim: The aim of this study was to develop poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) for delivery of a protein – tissue inhibitor of matrix metallo...
Continuous-flow free acid monitoring method and system
Strain, J.E.; Ross, H.H.
1980-01-11
A free acid monitoring method and apparatus is provided for continuously measuring the excess acid present in a process stream. The disclosed monitoring system and method is based on the relationship of the partial pressure ratio of water and acid in equilibrium with an acid solution at constant temperature. A portion of the process stream is pumped into and flows through the monitor under the influence of gravity and back to the process stream. A continuous flowing sample is vaporized at a constant temperature and the vapor is subsequently condensed. Conductivity measurements of the condensate produces a nonlinear response function from which the free acid molarity of the sample process stream is determined.
Frommer, A; Lippert, Th; Rittich, H
2012-01-01
The Lanczos process constructs a sequence of orthonormal vectors v_m spanning a nested sequence of Krylov subspaces generated by a hermitian matrix A and some starting vector b. In this paper we show how to cheaply recover a secondary Lanczos process, starting at an arbitrary Lanczos vector v_m and how to use this secondary process to efficiently obtain computable error estimates and error bounds for the Lanczos approximations to a solution of a linear system Ax = b as well as, more generally, for the Lanczos approximations to the action of a rational matrix function on a vector. Our approach uses the relation between the Lanczos process and quadrature as developed by Golub and Meurant. It is different from methods known so far because of its use of the secondary Lanczos process. With our approach, it is now in particular possible to efficiently obtain upper bounds for the error in the 2-norm, provided a lower bound on the smallest eigenvalue of A is known. This holds for the error of the cg iterates as well ...
All-order renormalization of propagator matrix for fermionic system with flavor mixing
Energy Technology Data Exchange (ETDEWEB)
Kniehl, Bernd A. [California Univ., Santa Barbara, CA (United States). Kavli Inst. for Theoretical Physics
2013-08-15
We consider a mixed system of Dirac fermions in a general parity-nonconserving theory and renormalize the propagator matrix to all orders in the pole scheme, in which the squares of the renormalized masses are identified with the complex pole positions and the wave-function renormalization (WFR) matrices are adjusted in compliance with the Lehmann-Symanzik-Zimmermann reduction formalism. We present closed analytic all-order expressions for the renormalization constants in terms of the scalar, pseudoscalar, vector, and pseudovector parts of the unrenormalized self-energy matrix, which is computable from the one-particle-irreducible Feynman diagrams of the flavor transitions. We identify residual degrees of freedom in the WFR matrices and propose an additional renormalization condition to exhaust them. We then explain how our results may be generalized to the case of unstable fermions, in which we encounter the phenomenon of WFR bifurcation. In the special case of a solitary unstable fermion, the all-order-renormalized propagator is presented in a particularly compact form.
RF Plasma Torch System for Metal Matrix Composite Production in Nuclear Fuel Cladding
Holik, Eddie, III
2007-10-01
For the first time in 30 years, plans are afoot to build new fission power plants in the US. It is timely to develop technology that could improve the safety and efficiency of new reactors. A program of development for advanced fuel cycles and Generation IV reactors is underway. The path to greater efficiency is to increase the core operating temperature. That places particular challenges to the cladding tubes that contain the fission fuel. A promising material for this purpose is a metal matrix composite (MMC) in which ceramic fibers are bonded within a high-strength steel matrix, much like fiberglass. Current MMC technology lacks the ability to effectively bond traditional high-temperature alloys to ceramic strands. The purpose of this project is to design an rf plasma torch system to use titanium as a buffer between the ceramic fibers and the refractory outer material. The design and methods of using an rf plasma torch to produce a non-equilibrium phase reaction to bond together the MMC will be discussed. The effects of having a long lived fuel cladding in the design of future reactors will also be discussed.
All-order renormalization of the propagator matrix for fermionic systems with flavor mixing.
Kniehl, Bernd A
2014-02-21
We consider a mixed system of Dirac fermions in a general parity-nonconserving theory and renormalize the propagator matrix to all orders in the pole scheme, in which the squares of the renormalized masses are identified with the complex pole positions and the wave-function renormalization (WFR) matrices are adjusted in compliance with the Lehmann-Symanzik-Zimmermann reduction formalism. We present closed analytic all-order expressions and their expansions through two loops for the renormalization constants in terms of the scalar, pseudoscalar, vector, and pseudovector parts of the unrenormalized self-energy matrix, which is computable from the one-particle-irreducible Feynman diagrams of the flavor transitions. We identify residual degrees of freedom in the WFR matrices and propose an additional renormalization condition to exhaust them. We then explain how our results may be generalized to the case of unstable fermions, in which we encounter the phenomenon of WFR bifurcation. In the special case of a solitary unstable fermion, the all-order-renormalized propagator is presented in a particularly compact form.
Ferreira, Fernanda N; Carneiro, Manuel C; Vaitsman, Delmo S; Pontes, Fernanda V M; Monteiro, Maria Inês C; Silva, Lílian Irene D da; Neto, Arnaldo Alcover
2012-02-03
A method for determination of formic, acetic, propionic and butyric acids in hypersaline waters by ion-exclusion chromatography (IEC), using steam distillation to eliminate matrix-interference, was developed. The steam distillation variables such as type of solution to collect the distillate, distillation time and volume of the 50% v/v H₂SO₄ solution were optimized. The effect of the addition of NaCl different concentrations to the calibration standards on the carboxylic acid recovery was also investigated. Detection limits of 0.2, 0.5, 0.3 and 1.5 mg L⁻¹ were obtained for formic, acetic, propionic and butyric acids, respectively. Produced waters from petroleum reservoirs in the Brazilian pre-salt layer containing about 19% m/v of NaCl were analyzed. Good recoveries (99-108%) were obtained for all acids in spiked produced water samples. Copyright © 2011 Elsevier B.V. All rights reserved.
Vogl, M.; Pankratov, O.; Shallcross, S.
2017-07-01
We present a tractable and physically transparent semiclassical theory of matrix-valued Hamiltonians, i.e., those that describe quantum systems with internal degrees of freedoms, based on a generalization of the Gutzwiller trace formula for a n ×n dimensional Hamiltonian H (p ̂,q ̂) . The classical dynamics is governed by n Hamilton-Jacobi (HJ) equations that act in a phase space endowed with a classical Berry curvature encoding anholonomy in the parallel transport of the eigenvectors of H (p ,q ) ; these vectors describe the internal structure of the semiclassical particles. At the O (ℏ1) level and for nondegenerate HJ systems, this curvature results in an additional semiclassical phase composed of (i) a Berry phase and (ii) a dynamical phase resulting from the classical particles "moving through the Berry curvature". We show that the dynamical part of this semiclassical phase will, generally, be zero only for the case in which the Berry phase is topological (i.e., depends only on the winding number). We illustrate the method by calculating the Landau spectrum for monolayer graphene, the four-band model of AB bilayer graphene, and for a more complicated matrix Hamiltonian describing the silicene band structure. Finally, we apply our method to an inhomogeneous system consisting of a strain engineered one-dimensional moiré in bilayer graphene, finding localized states near the Dirac point that arise from electron trapping in a semiclassical moiré potential. The semiclassical density of states of these localized states we show to be in perfect agreement with an exact quantum mechanical calculation of the density of states.
Directory of Open Access Journals (Sweden)
Delplanque Bernadette
2011-11-01
Full Text Available Dososahexaenoate (DHA is highly concentrated in mammalian nervous and visual systems and its deficiency during gestation, lactation and early life, could have dramatic impacts on brain functions and mental health. Achieving an appropriate DHA status in the neonatal brain is an important goal of neonatal nutrition. We evaluated how a-linolenic acid (ALA provided by different dietary fat matrices improved DHA content in the brains of both young male and female rats. Young rats born from dams fed during gestation and lactation with a low ALA diet (0.4% of fatty acids were subjected for 6 weeks after weaning to an anhydrous dairy fat blend-based diet that provided 1.5% ALA or to a palm oil blend-based diet that provided the same ALA level: either 1.5% ALA or 1.5% ALA and 0.12% DHA with 0.4% arachidonic acid (ARA. With each diet the n-6/ n-3 ratio was similar (10 to follow the values generally recommended for infant formula. Fatty acids analysis in whole brain showed that 1.5% ALA dairy fat blend was superior to both 1.5% ALA palm-oil blends, supplemented or not with dietary DHA, for increasing brain DHA. Females compared to males had significantly higher brain DHA with the 1.5% ALA palm-blend diet, but the dietary supplementation with DHA smoothed the differences by a specific increase of males DHA brain. In conclusion, dairy fat blend enriched with ALA appear to be an interesting strategy for achieving optimal DHA levels in the brain of post-weaning rats. Inclusion of dairy fat in infant formulas should be reconsidered.
Nucleic acid detection system and method for detecting influenza
Cai, Hong; Song, Jian
2015-03-17
The invention provides a rapid, sensitive and specific nucleic acid detection system which utilizes isothermal nucleic acid amplification in combination with a lateral flow chromatographic device, or DNA dipstick, for DNA-hybridization detection. The system of the invention requires no complex instrumentation or electronic hardware, and provides a low cost nucleic acid detection system suitable for highly sensitive pathogen detection. Hybridization to single-stranded DNA amplification products using the system of the invention provides a sensitive and specific means by which assays can be multiplexed for the detection of multiple target sequences.
Nucleic acid detection system and method for detecting influenza
Energy Technology Data Exchange (ETDEWEB)
Cai, Hong; Song, Jian
2015-03-17
The invention provides a rapid, sensitive and specific nucleic acid detection system which utilizes isothermal nucleic acid amplification in combination with a lateral flow chromatographic device, or DNA dipstick, for DNA-hybridization detection. The system of the invention requires no complex instrumentation or electronic hardware, and provides a low cost nucleic acid detection system suitable for highly sensitive pathogen detection. Hybridization to single-stranded DNA amplification products using the system of the invention provides a sensitive and specific means by which assays can be multiplexed for the detection of multiple target sequences.
Energy Technology Data Exchange (ETDEWEB)
Novaes, Marcel [Instituto de Física, Universidade Federal de Uberlândia, Ave. João Naves de Ávila, 2121, Uberlândia, MG 38408-100 (Brazil)
2015-06-15
We consider the statistics of time delay in a chaotic cavity having M open channels, in the absence of time-reversal invariance. In the random matrix theory approach, we compute the average value of polynomial functions of the time delay matrix Q = − iħS{sup †}dS/dE, where S is the scattering matrix. Our results do not assume M to be large. In a companion paper, we develop a semiclassical approximation to S-matrix correlation functions, from which the statistics of Q can also be derived. Together, these papers contribute to establishing the conjectured equivalence between the random matrix and the semiclassical approaches.
Novaes, Marcel
2015-06-01
We consider the statistics of time delay in a chaotic cavity having M open channels, in the absence of time-reversal invariance. In the random matrix theory approach, we compute the average value of polynomial functions of the time delay matrix Q = - iħS†dS/dE, where S is the scattering matrix. Our results do not assume M to be large. In a companion paper, we develop a semiclassical approximation to S-matrix correlation functions, from which the statistics of Q can also be derived. Together, these papers contribute to establishing the conjectured equivalence between the random matrix and the semiclassical approaches.
A Moebius-Strip Representation of the Matrix-Product Periodic System of Diatomic Molecules
Hefferlin, Ray
2007-04-01
Periodic systems of diatomic and triatomic molecules are well tested and documented [1]. The 3D form of the diatomic system consists of blocks, each having all molecules with two fixed-row atoms, on which the molecules are addressed by their atomic group numbers. The blocks can be replaced by tori [2], but in either case many redundancies exist (e.g., CO and OC). The tori [3] may be replaced by Moebius strips [4] which remove the redundancies. This representation of the periodic system will be presented. [1] Hefferlin, R., ``The Periodic Systems of Molecules, Presuppositions, Problems, and Prospects,'' Baird, D., Scerri, E., and McIntyre, L., Editors, Philosophy of Chemistry, Boston Studies in the Philosophy of Science, Springer, Dodrecht, the Netherlands, 2006. [2] Hefferlin, R,. ``Matrix-Product Periodic Systems of Molecules,'' J. Chem. Inf. Comput. Sci, 34, 314-317 (1994). [3] Hall, D. E, ``Quantitative Evaluation of Musical Scale Tunings,'' AJP, 42, 543-552 (1974). [4] Blau, S. K., ``Good Music unfolds in Small Steps,'' Physics Today, October 2006, pp. 19-21.
Evolutionary systems biology of amino acid biosynthetic cost in yeast.
Directory of Open Access Journals (Sweden)
Michael D Barton
Full Text Available Every protein has a biosynthetic cost to the cell based on the synthesis of its constituent amino acids. In order to optimise growth and reproduction, natural selection is expected, where possible, to favour the use of proteins whose constituents are cheaper to produce, as reduced biosynthetic cost may confer a fitness advantage to the organism. Quantifying the cost of amino acid biosynthesis presents challenges, since energetic requirements may change across different cellular and environmental conditions. We developed a systems biology approach to estimate the cost of amino acid synthesis based on genome-scale metabolic models and investigated the effects of the cost of amino acid synthesis on Saccharomyces cerevisiae gene expression and protein evolution. First, we used our two new and six previously reported measures of amino acid cost in conjunction with codon usage bias, tRNA gene number and atomic composition to identify which of these factors best predict transcript and protein levels. Second, we compared amino acid cost with rates of amino acid substitution across four species in the genus Saccharomyces. Regardless of which cost measure is used, amino acid biosynthetic cost is weakly associated with transcript and protein levels. In contrast, we find that biosynthetic cost and amino acid substitution rates show a negative correlation, but for only a subset of cost measures. In the economy of the yeast cell, we find that the cost of amino acid synthesis plays a limited role in shaping transcript and protein expression levels compared to that of translational optimisation. Biosynthetic cost does, however, appear to affect rates of amino acid evolution in Saccharomyces, suggesting that expensive amino acids may only be used when they have specific structural or functional roles in protein sequences. However, as there appears to be no single currency to compute the cost of amino acid synthesis across all cellular and environmental
Corrosion Inhibition by – Phthalic Acid - Zn2+ System
Directory of Open Access Journals (Sweden)
R. Mohan
2014-05-01
Full Text Available The inhibition effect of Phthalic acid(PA – Zn2+ system controls the corrosion of carbon steel has been studied by weight – loss method. The weight – loss study reveals that the formulation consisting of 60 ppm of Zn2+, 50 ppm of phthalic acid has 82 % inhibition efficiency. Synergistic effect exists between phthalic acid- Zn2+ system. The influence of N-cetyl- N, N, N-trimethylammonium bromide(CTAB on the PA- Zn2+ system control the microbial corrosion. The value of the separation factor, RL indicated the phthalic acid- Zn2+ system was favorable adsorption. The Adsorption equilibrium exhibited better fit to Langmuir isotherm than Freundlich isotherm. The protective film consists of Fe2+ - Phthalic acid and Zn(OH2 by FTIR spectroscopy.
Abscisic acid ameliorates the systemic sclerosis fibroblast phenotype in vitro
Energy Technology Data Exchange (ETDEWEB)
Bruzzone, Santina, E-mail: santina.bruzzone@unige.it [Department of Experimental Medicine, Section of Biochemistry, University of Genova, Viale Benedetto XV 1, 16132 Genova (Italy); Centre of Excellence for Biomedical Research, University of Genova, Viale Benedetto XV 9, 16132 Genova (Italy); Advanced Biotechnology Center, Largo Rosanna Benzi 10, 16132 Genova (Italy); Battaglia, Florinda [Centre of Excellence for Biomedical Research, University of Genova, Viale Benedetto XV 9, 16132 Genova (Italy); Mannino, Elena [Department of Experimental Medicine, Section of Biochemistry, University of Genova, Viale Benedetto XV 1, 16132 Genova (Italy); Parodi, Alessia [Centre of Excellence for Biomedical Research, University of Genova, Viale Benedetto XV 9, 16132 Genova (Italy); Fruscione, Floriana [Department of Experimental Medicine, Section of Biochemistry, University of Genova, Viale Benedetto XV 1, 16132 Genova (Italy); Advanced Biotechnology Center, Largo Rosanna Benzi 10, 16132 Genova (Italy); Basile, Giovanna [Department of Experimental Medicine, Section of Biochemistry, University of Genova, Viale Benedetto XV 1, 16132 Genova (Italy); Salis, Annalisa; Sturla, Laura [Department of Experimental Medicine, Section of Biochemistry, University of Genova, Viale Benedetto XV 1, 16132 Genova (Italy); Centre of Excellence for Biomedical Research, University of Genova, Viale Benedetto XV 9, 16132 Genova (Italy); Negrini, Simone; Kalli, Francesca; Stringara, Silvia [Centre of Excellence for Biomedical Research, University of Genova, Viale Benedetto XV 9, 16132 Genova (Italy); Filaci, Gilberto [Centre of Excellence for Biomedical Research, University of Genova, Viale Benedetto XV 9, 16132 Genova (Italy); Department of Internal Medicine, Viale Benedetto XV 6, 16132 Genova (Italy); and others
2012-05-25
Highlights: Black-Right-Pointing-Pointer ABA is an endogenous hormone in humans, regulating different cell responses. Black-Right-Pointing-Pointer ABA reverts some of the functions altered in SSc fibroblasts to a normal phenotype. Black-Right-Pointing-Pointer UV-B irradiation increases ABA content in SSc cultures. Black-Right-Pointing-Pointer SSc fibroblasts could benefit from exposure to ABA and/or to UV-B. -- Abstract: The phytohormone abscisic acid (ABA) has been recently identified as an endogenous hormone in humans, regulating different cell functions, including inflammatory processes, insulin release and glucose uptake. Systemic sclerosis (SSc) is a chronic inflammatory disease resulting in fibrosis of skin and internal organs. In this study, we investigated the effect of exogenous ABA on fibroblasts obtained from healthy subjects and from SSc patients. Migration of control fibroblasts induced by ABA was comparable to that induced by transforming growth factor-{beta} (TGF-{beta}). Conversely, migration toward ABA, but not toward TGF-{beta}, was impaired in SSc fibroblasts. In addition, ABA increased cell proliferation in fibroblasts from SSc patients, but not from healthy subjects. Most importantly, presence of ABA significantly decreased collagen deposition by SSc fibroblasts, at the same time increasing matrix metalloproteinase-1 activity and decreasing the expression level of tissue inhibitor of metalloproteinase (TIMP-1). Thus, exogenously added ABA appeared to revert some of the functions altered in SSc fibroblasts to a normal phenotype. Interestingly, ABA levels in plasma from SSc patients were found to be significantly lower than in healthy subjects. UV-B irradiation induced an almost 3-fold increase in ABA content in SSc cultures. Altogether, these results suggest that the fibrotic skin lesions in SSc patients could benefit from exposure to high(er) ABA levels.
Phenolic Acids in Plant-Soil-Microbe System: A Review
Institute of Scientific and Technical Information of China (English)
无
2002-01-01
Phenolic acids are very common compounds in pedosphere. The objective of this review was to summarize the current knowledge of the behaviors of phenolic acids in plant-soil-microbe system. When phenolic acids originated from leaching, decomposition and exudation of living and dead plant tissues enter soils, they can react physicochemically with soil particle surfaces and/or incorporate into humic matter. Phenolic acids desorbed from soil particle surfaces and remained in solution phase can be utilized by microbe as carbon sources and absorbed by plants. The degradation products of phenolic acids by microbe include some organic and/or inorganic compounds such as new phenolic acids. In addition, phenolic acids in soils can stimulate population and activity of microbe. Phenolic acids can inhibit plants growth by affecting ion leakage, phytohormone activity, membrane permeability, hydraulic conductivity, net nutrient uptake, and enzyme activity. Behaviors of phenolic acids in soils are influenced by other organic compounds (phenolic acids, methionine, glucose, etc.) and/or inorganic ions. The role of phenolic acids as allelopathic agents should not be neglected only based on their low specific concentrations in natural soils, because numbers and interactions of phenolic acids will increase their allelopathic activities.
Institute of Scientific and Technical Information of China (English)
Guangren DUAN; Yunli WU
2006-01-01
A type of high-order integral observers for matrix second-order linear systems is proposed on the basis of generalized eigenstructure assignment via unified parametric approaches. Through establishing two general parametric solutions to this type of generalized matrix second-order Sylvester matrix equations, two unified complete parametric methods for the proposed observer design problem are presented. Both methods give simple complete parametric expressions for the observer gain matrices. The first one mainly depends on a series of singular value decompositions, and is thus numerically simple and reliable; the second one utilizes the right factorization of the system, and allows eigenvalues of the error system to be set undetermined and sought via certain optimization procedures. A spring-mass-dashpot system is utilized to illustrate the design procedure and show the effect of the proposed approach.
Xin, Fan; Ming-Kai, Yun; Xiao-Li, Sun; Xue-Xiang, Cao; Shuang-Quanm, Liu; Pei, Chai; Dao-Wu, Li; Long, Wei
2014-01-01
In positron emission tomography (PET) imaging, statistical iterative reconstruction (IR) techniques appear particularly promising since they can provide accurate physical model and geometric system description. The reconstructed image quality mainly depends on the system matrix model which describes the relationship between image space and projection space for the IR method. The system matrix can contain some physics factors of detection such as geometrical component and blurring component. Point spread function (PSF) is generally used to describe the blurring component. This paper proposes an IR method based on the PSF system matrix, which is derived from the single photon incidence response function. More specifically, the gamma photon incidence on a crystal array is simulated by the Monte Carlo (MC) simulation, and then the single photon incidence response functions are obtained. Subsequently, using the single photon incidence response functions, the coincidence blurring factor is acquired according to the...
Huang, Hai; Kornberg, Thomas B
2016-09-03
Drosophila dorsal air sac development depends on Decapentaplegic (Dpp) and Fibroblast growth factor (FGF) proteins produced by the wing imaginal disc and transported by cytonemes to the air sac primordium (ASP). Dpp and FGF signaling in the ASP was dependent on components of the planar cell polarity (PCP) system in the disc, and neither Dpp- nor FGF-receiving cytonemes extended over mutant disc cells that lacked them. ASP cytonemes normally navigate through extracellular matrix (ECM) composed of collagen, laminin, Dally and Dally-like (Dlp) proteins that are stratified in layers over the disc cells. However, ECM over PCP mutant cells had reduced levels of laminin, Dally and Dlp, and whereas Dpp-receiving ASP cytonemes navigated in the Dally layer and required Dally (but not Dlp), FGF-receiving ASP cytonemes navigated in the Dlp layer, requiring Dlp (but not Dally). These findings suggest that cytonemes interact directly and specifically with proteins in the stratified ECM.
Input and state estimation for linear systems with a rank-deficient direct feedthrough matrix.
Wang, Haokun; Zhao, Jun; Xu, Zuhua; Shao, Zhijiang
2015-07-01
The problem of joint input and state estimation for linear stochastic systems with a rank-deficient direct feedthrough matrix is discussed in this paper. Results from previous studies only solve the state estimation problem; globally optimal estimation of the unknown input is not provided. Based on linear minimum-variance unbiased estimation, a five-step recursive filter with global optimality is proposed to estimate both the unknown input and the state. The relationship between the proposed filter and the existing results is addressed. We show that the unbiased input estimation does not require any new information or additional constraints. Both the state and the unknown input can be estimated under the same unbiasedness condition. Global optimalities of both the state estimator and the unknown input estimator are proven in the minimum-variance unbiased sense.
Matrix light and pixel light: optical system architecture and requirements to the light source
Spinger, Benno; Timinger, Andreas L.
2015-09-01
Modern Automotive headlamps enable improved functionality for more driving comfort and safety. Matrix or Pixel light headlamps are not restricted to either pure low beam functionality or pure high beam. Light in direction of oncoming traffic is selectively switched of, potential hazard can be marked via an isolated beam and the illumination on the road can even follow a bend. The optical architectures that enable these advanced functionalities are diverse. Electromechanical shutters and lens units moved by electric motors were the first ways to realize these systems. Switching multiple LED light sources is a more elegant and mechanically robust solution. While many basic functionalities can already be realized with a limited number of LEDs, an increasing number of pixels will lead to more driving comfort and better visibility. The required optical system needs not only to generate a desired beam distribution with a high angular dynamic, but also needs to guarantee minimal stray light and cross talk between the different pixels. The direct projection of the LED array via a lens is a simple but not very efficient optical system. We discuss different optical elements for pre-collimating the light with minimal cross talk and improved contrast between neighboring pixels. Depending on the selected optical system, we derive the basic light source requirements: luminance, surface area, contrast, flux and color homogeneity.
Directory of Open Access Journals (Sweden)
V. Yu. Kleshnin
2016-01-01
Full Text Available The article describes the matrix algebra libraries based on the modern technologies of parallel programming for the Spectrum software, which can use a spectral method (in the spectral form of mathematical description to analyse, synthesise and identify deterministic and stochastic dynamical systems. The developed matrix algebra libraries use the following technologies for the GPUs: OmniThreadLibrary, OpenMP, Intel Threading Building Blocks, Intel Cilk Plus for CPUs nVidia CUDA, OpenCL, and Microsoft Accelerated Massive Parallelism.The developed libraries support matrices with real elements (single and double precision. The matrix dimensions are limited by 32-bit or 64-bit memory model and computer configuration. These libraries are general-purpose and can be used not only for the Spectrum software. They can also find application in the other projects where there is a need to perform operations with large matrices.The article provides a comparative analysis of the libraries developed for various matrix operations (addition, subtraction, scalar multiplication, multiplication, powers of matrices, tensor multiplication, transpose, inverse matrix, finding a solution of the system of linear equations through the numerical experiments using different CPU and GPU. The article contains sample programs and performance test results for matrix multiplication, which requires most of all computational resources in regard to the other operations.
Ayorinde, F O; Garvin, K; Saeed, K
2000-01-01
A method using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS) for the determination of the fatty acid composition of vegetable oils is described and illustrated with the analysis of palm kernel oil, palm oil, olive oil, canola oil, soybean oil, vernonia oil, and castor oil. Solutions of the saponified oils, mixed with the matrix, meso-tetrakis(pentafluorophenyl)porphyrin, provided reproducible MALDI-TOF spectra in which the ions were dominated by sodiated sodium carboxylates [RCOONa + Na]+. Thus, palm kernel oil was found to contain capric acid, lauric acid, myristic acid, palmitic acid, oleic acid, and stearic acid. Palm oil had a fatty acid profile including palmitic, linoleic, oleic, and stearic. The relative percentages of the fatty acids in olive oil were palmitoleic (1.2 +/- 0.5), palmitic (10.9 +/- 0.8), linoleic (0.6 +/- 0.1), linoleic (16.5 +/- 0.8), and oleic (70.5 +/- 1.2). For soybean oil, the relative percentages were: palmitoleic (0.4 +/- 0.4), palmitic (6.0 +/- 1.3), linolenic (14.5 +/- 1.8), linoleic (50.1 +/- 4.0), oleic (26.1 +/- 1.2), and stearic (2.2 +/- 0.7). This method was also applied to the analysis of two commercial soap formulations. The first soap gave a fatty acid profile that included: lauric (19.4% +/- 0.8), myristic (9.6% +/- 0.5), palmitoleic (1.9% +/- 0.3), palmitic (16.3% +/- 0.9), linoleic (5.6% +/- 0.4), oleic (37.1% +/- 0.8), and stearic (10.1% +/- 0.7) and that of the second soap was: lauric (9.3% +/- 0.3), myristic (3.8% +/- 0.5), palmitoleic (3.1% +/- 0.8), palmitic (19.4% +/- 0.8), linoleic (4.9% +/- 0.7), oleic (49.5% +/- 1.1), and stearic (10.0% +/- 0.9). The MALDI-TOFMS method described in this communication is simpler and less time-consuming than the established transesterification method that is coupled with analysis by gas chromatography/mass spectrometry (GC/MS). The new method could be used routinely to determine the qualitative fatty acid composition of vegetable oils
Directory of Open Access Journals (Sweden)
Harmanescu Monica
2012-01-01
Full Text Available Abstract Background The aim of our work was to compare two methods, both based on direct transmethylation with different reagents, BF3/MeOH (boron trifluoride in methanol or HCl/MeOH (hydrochloride acid in methanol, in acid catalysis, without prior extraction, to find the fast, non-expensive but enough precise method for 9 principal fatty acids (lauric, myristic, palmitic, stearic, oleic, linoleic, linolenic, arahidic and behenic acids analysis in vegetal matrix with low fat content (forage from grassland, for nutrition and agrochemical studies. Results Comparatively, between the average values obtained for all analysed fatty acids by the two methods based on direct transmethylation without prior extraction no significantly difference was identified (p > 0.05. The results of fatty acids for the same forage sample were more closely to their average value, being more homogenous for BF3/MeOH than HCl/MeOH, because of the better accuracy and repeatability of this method. Method that uses BF3/MeOH reagent produces small amounts of interfering compounds than the method using HCl/MeOH reagent, results reflected by the better statistical parameters. Conclusion The fast and non-expensive BF3/methanol method was applied with good accuracy and sensitivity for the determination of free or combined fatty acids (saturated and unsaturated in forage matrix with low fat content from grassland. Also, the final extract obtained by this method, poorer in interfering compounds, is safer to protect the injector and column from contamination with heavy or non-volatile compounds formed by transmethylation reactions.
On the Centro-symmetric Solution of a System of Matrix Equations over a Regular Ring with Identity
Institute of Scientific and Technical Information of China (English)
Qingwen Wang; Haixia Chang; Chunyan Lin
2007-01-01
In this paper, we find the centro-symmetric solution of a system of matrix equations over an arbitrary regular ring R with identity. We first derive some necessary and sufficient conditions for the existence and an explicit expression of the general solution of the system of matrix equations A1X1 = C1, A2X1 = C2, A3X2 = C3, A4X2 = C4 and A5X1B5 + A6X2B6= C5 over R. By using the above results, we establish two criteria for the existence and the representation of the general centro-symmetric solution of the system of matrix equations AaX = Ca, AbX = Cb and AcXBc = Cc over the ring R.
Coe, Jeremy P; Almeida, Nuno M S; Paterson, Martin J
2017-09-02
We investigate if a range of challenging spin systems can be described sufficiently well using Monte Carlo configuration interaction (MCCI) and the density matrix renormalization group (DMRG) in a way that heads toward a more "black box" approach. Experimental results and other computational methods are used for comparison. The gap between the lowest doublet and quartet state of methylidyne (CH) is first considered. We then look at a range of first-row transition metal monocarbonyls: MCO when M is titanium, vanadium, chromium, or manganese. For these MCO systems we also employ partially spin restricted open-shell coupled-cluster (RCCSD). We finally investigate the high-spin low-lying states of the iron dimer, its cation and its anion. The multireference character of these molecules is also considered. We find that these systems can be computationally challenging with close low-lying states and often multireference character. For this more straightforward application and for the basis sets considered, we generally find qualitative agreement between DMRG and MCCI. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.
On the Free Vibration Modeling of Spindle Systems: A Calibrated Dynamic Stiffness Matrix
Directory of Open Access Journals (Sweden)
Omar Gaber
2014-01-01
Full Text Available The effect of bearings on the vibrational behavior of machine tool spindles is investigated. This is done through the development of a calibrated dynamic stiffness matrix (CDSM method, where the bearings flexibility is represented by massless linear spring elements with tuneable stiffness. A dedicated MATLAB code is written to develop and to assemble the element stiffness matrices for the system’s multiple components and to apply the boundary conditions. The developed method is applied to an illustrative example of spindle system. When the spindle bearings are modeled as simply supported boundary conditions, the DSM model results in a fundamental frequency much higher than the system’s nominal value. The simply supported boundary conditions are then replaced by linear spring elements, and the spring constants are adjusted such that the resulting calibrated CDSM model leads to the nominal fundamental frequency of the spindle system. The spindle frequency results are also validated against the experimental data. The proposed method can be effectively applied to predict the vibration characteristics of spindle systems supported by bearings.
Shaping the Future Landscape: Catchment Systems Engineering and the Decision Support Matrix Approach
Hewett, Caspar; Quinn, Paul; Wilkinson, Mark; Wainwright, John
2017-04-01
Land degradation is widely recognised as one of the great environmental challenges facing humanity today, much of which is directly associated with human activity. The negative impacts of climate change and of the way in which we have engineered the landscape through, for example, agriculture intensification and deforestation, need to be addressed. However, the answer is not a simple matter of doing the opposite of current practice. Nor is non-intervention a viable option. There is a need to bring together approaches from the natural and social sciences both to understand the issues and to act to solve real problems. We propose combining a Catchment Systems Engineering (CSE) approach that builds on existing approaches such as Natural Water Retention Measures, Green infrastructure and Nature-Based Solutions with a multi-scale framework for decision support that has been successfully applied to diffuse pollution and flood risk management. The CSE philosophy follows that of Earth Systems Engineering and Management, which aims to engineer and manage complex coupled human-natural systems in a highly integrated, rational manner. CSE is multi-disciplinary, and necessarily involves a wide range of subject areas including anthropology, engineering, environmental science, ethics and philosophy. It offers a rational approach which accepts the fact that we need to engineer and act to improve the functioning of the existing catchment entity on which we rely. The decision support framework proposed draws on physical and mathematical modelling; Participatory Action Research; and demonstration sites at which practical interventions are implemented. It is predicated on the need to work with stakeholders to co-produce knowledge that leads to proactive interventions to reverse the land degradation we observe today while sustaining the agriculture humanity needs. The philosophy behind CSE and examples of where it has been applied successfully are presented. The Decision Support Matrix
Phase diagram of the ternary system lauric acid-capric acid-naphthalene
Energy Technology Data Exchange (ETDEWEB)
Longfei, Jin; Fengping, Xiao [College of Chemistry, Central China Normal University, Wuhan 430079 (China)
2004-12-15
The mixture of lauric acid and capric acid is a potential latent heat storage material. However, its eutectic melting temperature is quite high for low-temperature thermal energy storage. Addition of naphthalene is proposed. The ternary system lauric acid-capric acid-naphthalene has been investigated by differential scanning calorimetry (DSC), visual polythermal and chromatography of gases. The phase diagram is of an incongruent eutectic type. The eutectic mixture contains 18.4mol% lauric acid, 63.1mol% capric acid and 18.5mol% naphthalene and melts at 13.3{sup o}C. The peritectic mixture contains 32.4mol% lauric acid, 48.2mol% capric acid and 19.4mol% naphthalene and peritectic temperature of 16.2{sup o}C. The incongruent compound was analysed to be CH{sub 3}(CH{sub 2}){sub 10}COOH.CH{sub 3}(CH{sub 2}){sub 8}COOH. The melting temperature of the lauric acid-capric acid-naphthalene eutectic mixture makes it suitable for cooling applications.
Liu, Li; Song, Cunyi; Yan, Zengguang; Li, Fasheng
2009-09-01
Although excitation-emission matrix spectroscopy (EEMS) has been widely used to characterize dissolved organic matter (DOM), there has no report that EEMS has been used to study the effects of acid rain on DOM and its composition in soil. In this work, we employed three-dimensional EEMS to characterize the compositions of DOM leached by simulated acid rain from red soil. The red soil was subjected to leaching of simulated acid rain of different acidity, and the leached DOM presented five main peaks in its EEMS: peak-A, related to humic acid-like (HA-like) material, at Ex/Em of 310-330/395-420nm; peak-B, related to UV fulvic acid-like (FA-like) material, at Ex/Em of 230-280/400-435nm; peak-C and peak-D, both related to microbial byproduct-like material, at Ex/Em of 250-280/335-355nm and 260-280/290-320nm, respectively; and peak-E, related to simple aromatic proteins, at Ex/Em of 210-240/290-340nm. EEMS analysis results indicated that most DOM could be lost from red soil in the early phase of acid rain leaching. In addition to the effects of the pH of acid rain, the loss of DOM also depended on the properties of its compositions and the solubility of their complexes with aluminum. HA-like and microbial byproduct-like materials could be more easily released from red soil by acid rain at both higher pH (4.5 and 5.6) and lower pH (2.5 and 3) than that at middle pH (3.5). On the contrary, FA-like material lost in a similar manner under the action of different acid rains with pH ranging from 2.5 to 5.6.
Sun, Zhao-Yang; Shen, Ming-Xing; Yang, An-Wen; Liang, Cong-Qiang; Wang, Nan; Cao, Gui-Ping
2011-01-21
Biodegradable copolymers with molecule inclusion ability was prepared by introduction of β-cyclodextrin into poly(aspartic acid) matrices. The ibuprofen loading and dissolution properties of poly(aspartic acid)-β-cyclodextrin were investigated.
Amino Acid Synthesis in a Supercritical Carbon Dioxide - Water System
2009-01-01
Mars is a CO2-abundant planet, whereas early Earth is thought to be also CO2-abundant. In addition, water was also discovered on Mars in 2008. From the facts and theory, we assumed that soda fountains were present on both planets, and this affected amino acid synthesis. Here, using a supercritical CO2/liquid H2O (10:1) system which mimicked crust soda fountains, we demonstrate production of amino acids from hydroxylamine (nitrogen source) and keto acids (oxylic acid sources). In this research...
Shishkov, Alexander; Bogacheva, Elena; Fedorova, Natalia; Ksenofontov, Alexander; Badun, Gennadii; Radyukhin, Victor; Lukashina, Elena; Serebryakova, Marina; Dolgov, Alexey; Chulichkov, Alexey; Dobrov, Evgeny; Baratova, Lyudmila
2011-12-01
The structure of the C-terminal domain of the influenza virus A matrix M1 protein, for which X-ray diffraction data were still missing, was studied in acidic solution. Matrix M1 protein was bombarded with thermally-activated tritium atoms, and the resulting intramolecular distribution of the tritium label was analyzed to assess the steric accessibility of the amino acid residues in this protein. This technique revealed that interdomain loops and the C-terminal domain of the protein are the most accessible to labeling with tritium atoms. A model of the spatial arrangement of the C-terminal domain of matrix M1 protein was generated using rosetta software adjusted to the data obtained by tritium planigraphy experiments. This model suggests that the C-terminal domain is an almost flat layer with a three-α-helical structure. To explain the high level of tritium label incorporation into the C-terminal domain of the M1 protein in an acidic solution, we also used independent experimental approaches (CD spectroscopy, limited proteolysis and MALDI-TOF MS analysis of the proteolysis products, dynamic light scattering and analytical ultracentrifugation), as well as multiple computational algorithms, to analyse the intrinsic protein disorder. Taken together, the results obtained in the present study indicate that the C-terminal domain is weakly structured. We hypothesize that the specific 3D structural peculiarities of the M1 protein revealed in acidic pH solution allow the protein greater structural flexibility and enable it to interact effectively with the components of the host cell.
Herrin, Stephanie; Iverson, David; Spukovska, Lilly; Souza, Kenneth A. (Technical Monitor)
1994-01-01
Failure Modes and Effects Analysis contain a wealth of information that can be used to create the knowledge base required for building automated diagnostic Expert systems. A real time monitoring and diagnosis expert system based on an actual NASA project's matrix failure modes and effects analysis was developed. This Expert system Was developed at NASA Ames Research Center. This system was first used as a case study to monitor the Research Animal Holding Facility (RAHF), a Space Shuttle payload that is used to house and monitor animals in orbit so the effects of space flight and microgravity can be studied. The techniques developed for the RAHF monitoring and diagnosis Expert system are general enough to be used for monitoring and diagnosis of a variety of other systems that undergo a Matrix FMEA. This automated diagnosis system was successfully used on-line and validated on the Space Shuttle flight STS-58, mission SLS-2 in October 1993.
300 Area waste acid treatment system closure plan. Revision 1
Energy Technology Data Exchange (ETDEWEB)
NONE
1996-03-01
This section provides a description of the Hanford Site, identifies the proposed method of 300 Area Waste Acid Treatment System (WATS) closure, and briefly summarizes the contents of each chapter of this plan.
Amino Acid Synthesis in a Supercritical Carbon Dioxide - Water System
Directory of Open Access Journals (Sweden)
Akiyoshi Hoshino
2009-06-01
Full Text Available Mars is a CO2-abundant planet, whereas early Earth is thought to be also CO2-abundant. In addition, water was also discovered on Mars in 2008. From the facts and theory, we assumed that soda fountains were present on both planets, and this affected amino acid synthesis. Here, using a supercritical CO2/liquid H2O (10:1 system which mimicked crust soda fountains, we demonstrate production of amino acids from hydroxylamine (nitrogen source and keto acids (oxylic acid sources. In this research, several amino acids were detected with an amino acid analyzer. Moreover, alanine polymers were detected with LC-MS. Our research lights up a new pathway in the study of life’s origin.
Alvarez, G.
2009-09-01
The purpose of this paper is (i) to present a generic and fully functional implementation of the density-matrix renormalization group (DMRG) algorithm, and (ii) to describe how to write additional strongly-correlated electron models and geometries by using templated classes. Besides considering general models and geometries, the code implements Hamiltonian symmetries in a generic way and parallelization over symmetry-related matrix blocks. Program summaryProgram title: DMRG++ Catalogue identifier: AEDJ_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEDJ_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: See file LICENSE No. of lines in distributed program, including test data, etc.: 15 795 No. of bytes in distributed program, including test data, etc.: 83 454 Distribution format: tar.gz Programming language: C++, MPI Computer: PC, HP cluster Operating system: Any, tested on Linux Has the code been vectorized or parallelized?: Yes RAM: 1 GB (256 MB is enough to run included test) Classification: 23 External routines: BLAS and LAPACK Nature of problem: Strongly correlated electrons systems, display a broad range of important phenomena, and their study is a major area of research in condensed matter physics. In this context, model Hamiltonians are used to simulate the relevant interactions of a given compound, and the relevant degrees of freedom. These studies rely on the use of tight-binding lattice models that consider electron localization, where states on one site can be labeled by spin and orbital degrees of freedom. The calculation of properties from these Hamiltonians is a computational intensive problem, since the Hilbert space over which these Hamiltonians act grows exponentially with the number of sites on the lattice. Solution method: The DMRG is a numerical variational technique to study quantum many body Hamiltonians. For one-dimensional and quasi one-dimensional systems, the
Mixed solvent system for treating acidic gas
Energy Technology Data Exchange (ETDEWEB)
Capobianco, P.J.; Butwell, K.F.; Kossakowski, E.J.
1987-11-10
This invention discloses mixtures of alkyl dialcohol amines and mono alkyl ethers of polyethylene glycols which are useful in removing acidic gases from gaseous mixtures. The solvent mixtures contain between 1.5 N and 5.0 N methyl diethanolamine (MDEA), 10 to 40 percent water and the balance is methoxytriglycol (MTG). The overall heat of reaction of the solution is typically less than 500 BTU/lb CO/sub 2/, and remains as a single liquid phase during normal gas scrubber operating conditions.
Acid-base homeostasis in the human system
White, R. J.
1974-01-01
Acid-base regulation is a cooperative phenomena in vivo with body fluids, extracellular and intracellular buffers, lungs, and kidneys all playing important roles. The present account is much too brief to be considered a review of present knowledge of these regulatory systems, and should be viewed, instead, as a guide to the elements necessary to construct a simple model of the mutual interactions of the acid-base regulatory systems of the body.
Giesbertz, K J H; Pernal, K; Gritsenko, O V; Baerends, E J
2009-03-21
Time-dependent density functional theory in its current adiabatic implementations exhibits three striking failures: (a) Totally wrong behavior of the excited state surface along a bond-breaking coordinate, (b) lack of doubly excited configurations, affecting again excited state surfaces, and (c) much too low charge transfer excitation energies. We address these problems with time-dependent density matrix functional theory (TDDMFT). For two-electron systems the exact exchange-correlation functional is known in DMFT, hence exact response equations can be formulated. This affords a study of the performance of TDDMFT in the TDDFT failure cases mentioned (which are all strikingly exhibited by prototype two-electron systems such as dissociating H(2) and HeH(+)). At the same time, adiabatic approximations, which will eventually be necessary, can be tested without being obscured by approximations in the functional. We find the following: (a) In the fully nonadiabatic (omega-dependent, exact) formulation of linear response TDDMFT, it can be shown that linear response (LR)-TDDMFT is able to provide exact excitation energies, in particular, the first order (linear response) formulation does not prohibit the correct representation of doubly excited states; (b) within previously formulated simple adiabatic approximations the bonding-to-antibonding excited state surface as well as charge transfer excitations are described without problems, but not the double excitations; (c) an adiabatic approximation is formulated in which also the double excitations are fully accounted for.
Classical integrable systems and soliton equations related to eleven-vertex R-matrix
Directory of Open Access Journals (Sweden)
A. Levin
2014-10-01
Full Text Available In our recent paper we suggested a natural construction of the classical relativistic integrable tops in terms of the quantum R-matrices. Here we study the simplest case – the 11-vertex R-matrix and related gl2 rational models. The corresponding top is equivalent to the 2-body Ruijsenaars–Schneider (RS or the 2-body Calogero–Moser (CM model depending on its description. We give different descriptions of the integrable tops and use them as building blocks for construction of more complicated integrable systems such as Gaudin models and classical spin chains (periodic and with boundaries. The known relation between the top and CM (or RS models allows to rewrite the Gaudin models (or the spin chains in the canonical variables. Then they assume the form of n-particle integrable systems with 2n constants. We also describe the generalization of the top to 1+1 field theories. It allows us to get the Landau–Lifshitz type equation. The latter can be treated as non-trivial deformation of the classical continuous Heisenberg model. In a similar way the deformation of the principal chiral model is described.
Hollstein, André; Fischer, Jürgen
2012-05-01
Accurate radiative transfer models are the key tools for the understanding of radiative transfer processes in the atmosphere and ocean, and for the development of remote sensing algorithms. The widely used scalar approximation of radiative transfer can lead to errors in calculated top of atmosphere radiances. We show results with errors in the order of±8% for atmosphere ocean systems with case one waters. Variations in sea water salinity and temperature can lead to variations in the signal of similar magnitude. Therefore, we enhanced our scalar radiative transfer model MOMO, which is in use at Freie Universität Berlin, to treat these effects as accurately as possible. We describe our one-dimensional vector radiative transfer model for an atmosphere ocean system with a rough interface. We describe the matrix operator scheme and the bio-optical model for case one waters. We discuss some effects of neglecting polarization in radiative transfer calculations and effects of salinity changes for top of atmosphere radiances. Results are shown for the channels of the satellite instruments MERIS and OLCI from 412.5 nm to 900 nm.
Classical integrable systems and soliton equations related to eleven-vertex R-matrix
Energy Technology Data Exchange (ETDEWEB)
Levin, A., E-mail: alevin@hse.ru [NRU HSE, Department of Mathematics, Myasnitskaya str. 20, Moscow, 101000 (Russian Federation); ITEP, B. Cheremushkinskaya str. 25, Moscow, 117218 (Russian Federation); Olshanetsky, M., E-mail: olshanet@itep.ru [ITEP, B. Cheremushkinskaya str. 25, Moscow, 117218 (Russian Federation); MIPT, Institutskii per. 9, Dolgoprudny, Moscow Region, 141700 (Russian Federation); Zotov, A., E-mail: zotov@mi.ras.ru [Steklov Mathematical Institute RAS, Gubkina str. 8, Moscow, 119991 (Russian Federation); ITEP, B. Cheremushkinskaya str. 25, Moscow, 117218 (Russian Federation); MIPT, Institutskii per. 9, Dolgoprudny, Moscow Region, 141700 (Russian Federation)
2014-10-15
In our recent paper we suggested a natural construction of the classical relativistic integrable tops in terms of the quantum R-matrices. Here we study the simplest case – the 11-vertex R-matrix and related gl{sub 2} rational models. The corresponding top is equivalent to the 2-body Ruijsenaars–Schneider (RS) or the 2-body Calogero–Moser (CM) model depending on its description. We give different descriptions of the integrable tops and use them as building blocks for construction of more complicated integrable systems such as Gaudin models and classical spin chains (periodic and with boundaries). The known relation between the top and CM (or RS) models allows to rewrite the Gaudin models (or the spin chains) in the canonical variables. Then they assume the form of n-particle integrable systems with 2n constants. We also describe the generalization of the top to 1+1 field theories. It allows us to get the Landau–Lifshitz type equation. The latter can be treated as non-trivial deformation of the classical continuous Heisenberg model. In a similar way the deformation of the principal chiral model is described.
Classical integrable systems and soliton equations related to eleven-vertex R-matrix
Levin, A.; Olshanetsky, M.; Zotov, A.
2014-10-01
In our recent paper we suggested a natural construction of the classical relativistic integrable tops in terms of the quantum R-matrices. Here we study the simplest case - the 11-vertex R-matrix and related gl2 rational models. The corresponding top is equivalent to the 2-body Ruijsenaars-Schneider (RS) or the 2-body Calogero-Moser (CM) model depending on its description. We give different descriptions of the integrable tops and use them as building blocks for construction of more complicated integrable systems such as Gaudin models and classical spin chains (periodic and with boundaries). The known relation between the top and CM (or RS) models allows to rewrite the Gaudin models (or the spin chains) in the canonical variables. Then they assume the form of n-particle integrable systems with 2n constants. We also describe the generalization of the top to 1+1 field theories. It allows us to get the Landau-Lifshitz type equation. The latter can be treated as non-trivial deformation of the classical continuous Heisenberg model. In a similar way the deformation of the principal chiral model is described.
Classical integrable systems and soliton equations related to eleven-vertex R-matrix
Levin, A; Zotov, A
2014-01-01
In our recent paper we suggested a natural construction of the classical relativistic integrable tops in terms of the quantum $R$-matrices. Here we study the simplest case -- the 11-vertex $R$-matrix and related ${\\rm gl}_2$ rational models. The corresponding top is equivalent to the 2-body Ruijsenaars-Schneider (RS) or the 2-body Calogero-Moser (CM) model depending on its description. We give different descriptions of the integrable tops and use them as building blocks for construction of more complicated integrable systems such as Gaudin models and classical spin chains (periodic and with boundaries). The known relation between the top and CM (or RS) models allows to re-write the Gaudin models (or the spin chains) in the canonical variables. Then they assume the form of $n$-particle integrable systems with $2n$ constants. We also describe the generalization of the top to 1+1 field theories. It allows us to get the Landau-Lifshitz type equation. The latter can be treated as non-trivial deformation of the cla...
Reduced-density-matrix spectrum and block entropy of permutationally invariant many-body systems.
Salerno, Mario; Popkov, Vladislav
2010-07-01
Spectral properties of the reduced density matrix (RDM) of permutational invariant quantum many-body systems are investigated. The RDM block diagonalization which accounts for all symmetries of the Hamiltonian is achieved. The analytical expression of the RDM spectrum is provided for arbitrary parameters and rigorously proved in the thermodynamical limit. The existence of several sum rules and recurrence relations among RDM eigenvalues is also demonstrated and the distribution function of RDM eigenvalues (including degeneracies) characterized. In particular, we prove that the distribution function approaches a two-dimensional Gaussian in the limit of large subsystem sizes n>1. As a physical application we discuss the von Neumann entropy (VNE) of a block of size n for a system of hard-core bosons on a complete graph, as a function of n and of the temperature T. The occurrence of a crossover of VNE from purely logarithmic behavior at T=0 to a purely linear behavior in n for T≥Tc, is demonstrated.
Equivalence of matrix product ensembles of trajectories in open quantum systems.
Kiukas, Jukka; Guţă, Mădălin; Lesanovsky, Igor; Garrahan, Juan P
2015-07-01
The equivalence of thermodynamic ensembles is at the heart of statistical mechanics and central to our understanding of equilibrium states of matter. Recently, a formal connection has been established between the dynamics of open quantum systems and statistical mechanics in an extra dimension: an open system dynamics generates a matrix product state (MPS) encoding all possible quantum jump trajectories which allows to construct generating functions akin to partition functions. For dynamics generated by a Lindblad master equation, the corresponding MPS is a so-called continuous MPS which encodes the set of continuous measurement records terminated at some fixed total observation time. Here, we show that if one instead terminates trajectories after a fixed total number of quantum jumps, e.g., emission events into the environment, the associated MPS is discrete. The continuous and discrete MPS correspond to different ensembles of quantum trajectories, one characterized by total time, the other by total number of quantum jumps. Hence, they give rise to quantum versions of different thermodynamic ensembles, akin to "grand canonical" and "isobaric," but for trajectories. Here, we prove that these trajectory ensembles are equivalent in a suitable limit of long time or large number of jumps. This is in direct analogy to equilibrium statistical mechanics where equivalence between ensembles is only strictly established in the thermodynamic limit. An intrinsic quantum feature is that the equivalence holds only for all observables that commute with the number of quantum jumps.
DEFF Research Database (Denmark)
Meyer, Anne Merete Boye; Jacobsen, Charlotte Munch
1996-01-01
Meyer, A. S. & C. Jacobsen, 1996. Fate of the synergistic antioxidant system ascorbic acid, lecithin, and tocopherol in mayonnaise: Partion of ascorbic acid, J. Food Lipids, 3, 139-147.......Meyer, A. S. & C. Jacobsen, 1996. Fate of the synergistic antioxidant system ascorbic acid, lecithin, and tocopherol in mayonnaise: Partion of ascorbic acid, J. Food Lipids, 3, 139-147....
DEFF Research Database (Denmark)
Meyer, Anne Merete Boye; Jacobsen, Charlotte Munch
1996-01-01
Meyer, A. S. & C. Jacobsen, 1996. Fate of the synergistic antioxidant system ascorbic acid, lecithin, and tocopherol in mayonnaise: Partion of ascorbic acid, J. Food Lipids, 3, 139-147.......Meyer, A. S. & C. Jacobsen, 1996. Fate of the synergistic antioxidant system ascorbic acid, lecithin, and tocopherol in mayonnaise: Partion of ascorbic acid, J. Food Lipids, 3, 139-147....
Aqueous flow and transport in analog systems of fractures embedded in permeable matrix
DEFF Research Database (Denmark)
Sonnenborg, Torben Obel; Butts, Michael Brian; Jensen, Karsten Høgh
1999-01-01
different configurations: (1) matrix only, (2) and (3) matrix blocks containing single fractures of different mean apertures, and (4) a brickwork pattern setup simulating a tortuous multiple fracture network. The observed partitioning of flow and solute concentrations suggested mass exchange between...
Development of an integrated system for activity-based profiling of matrix metallo-proteases
Freije, Jan Robert
2006-01-01
Matrix metallo-proteases constitute a family of extracellular zinc-dependent endopeptidases that are involved in degradation of extracellular matrix (ECM) components and other bioactive non-ECM molecules. A plethora of studies have implicated important roles for MMPs in many diseases (including
Development of an integrated system for activity-based profiling of matrix metallo-proteases
Freije, Jan Robert
2006-01-01
Matrix metallo-proteases constitute a family of extracellular zinc-dependent endopeptidases that are involved in degradation of extracellular matrix (ECM) components and other bioactive non-ECM molecules. A plethora of studies have implicated important roles for MMPs in many diseases (including canc
Institute of Scientific and Technical Information of China (English)
Zhi Hua WANG; Min CAI; Shu Jun WANG
2006-01-01
The effects of matrix silicate and experimental conditions on the determination of iron in flame atomic absorption spectrometry (FAAS) were investigated. It was found that boric acid as a matrix modifier obviously eliminated silicate interference. Under the optimum operating conditions, the determination results of iron in layered crystal sodium disilicate and sodium silicate samples by FAAS were satisfactory. The linear range of calibration curve is 0-10.5 μg.mL-1, the relative standard deviation of method is 1.2%-2.2%, the recovery of added iron is 96.0%-101%, the of iron of the standard curve method, standard addition calibration and colorimetry method was the same, but the first has the merits of rapid sample preparation, reduced contamination risks and fast analysis.
Institute of Scientific and Technical Information of China (English)
Wu Yunli; Duan Guangren
2006-01-01
A simple method for disturbance decoupling for matrix second-order linear systems is proposed directly in matrix second-order framework via Luenberger function observers based on complete parametric eigenstructure assignment.By introducing the H2 norm of the transfer function from disturbance to estimation error, sufficient and necessary conditions for disturbance decoupling in matrix second-order linear systems are established and are arranged into constraints on the design parameters via Luenberger function observers in terms of the closed-loop eigenvalues and the group of design parameters provided by the eigenstructure assignment approach. Therefore, the disturbance decoupling problem is converted into an eigenstructure assignment problem with extra parameter constraints. A simple example is investigated to show the effect and simplicity of the approach.
DEFF Research Database (Denmark)
Chambon, Julie Claire Claudia; Broholm, Mette Martina; Binning, Philip John;
2010-01-01
and the contaminant flux out of the clay system are assessed for different distributions of microbial degradation. Results from a set of scenarios show that time to remove 90% of the initial mass is halved when dechlorination occurs in a 5 cm reaction zone in the clay at the fracture-matrix interface (from 419 to 195...... to the physical processes, mainly diffusion in the matrix, than to the biogeochemical processes, when dechlorination is assumed to take place in a limited reaction zone only. The inclusion of sequential dechlorination in clay fracture transport models is crucial, as the contaminant flux to the aquifer...... of a contaminant in a single fracture-clay matrix system coupled with a reactive model for anaerobic dechlorination. The model takes into account microbially driven anaerobic dechlorination, where sequential Monod kinetics with competitive inhibition is used to model the reaction rates, and degradation...
Energy Technology Data Exchange (ETDEWEB)
Zhang, Yaping [Department of Biophysics and Structural Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and School of Basic Medicine, Peking Union Medical College, 5 Dongdan San Tiao, Beijing 100005 (China); Wang, Yanmin [Department of Clinical Laboratory, Heze Municipal Hospital, Shandong (China); Guo, Shuai; Guo, Yumei; Liu, Hui [Department of Biophysics and Structural Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and School of Basic Medicine, Peking Union Medical College, 5 Dongdan San Tiao, Beijing 100005 (China); Li, Zhili, E-mail: lizhili@ibms.pumc.edu.cn [Department of Biophysics and Structural Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and School of Basic Medicine, Peking Union Medical College, 5 Dongdan San Tiao, Beijing 100005 (China)
2013-09-10
Graphical abstract: -- Highlights: •A novel MALDI matrix for the detection of serum free fatty acids is ammonia-treated N-(1-naphthyl) ethylenediamine dihydrochloride. •Multiple point internal standard calibration curves were constructed for nine FFAs, respectively, with excellent correlation coefficients between 0.991 and 0.999. •The MALDI-MS approach was used to rapidly differentiate the patients with and without hyperglycemia and healthy controls. -- Abstract: The blood free fatty acids (FFAs), which provide energy to the cell and act as substrates in the synthesis of fats, lipoproteins, liposaccharides, and eicosanoids, involve in a number of important physiological processes. In the present study, matrix-assisted laser desorption/ionization-Fourier transform ion cyclotron resonance mass spectrometry (MALDI-FTICR MS) with ammonia-treated N-(1-naphthyl) ethylenediamine dihydrochloride (ATNEDC) as a novel MALDI matrix in a negative ion mode was employed to directly quantify serum FFAs. Multiple point internal standard calibration curves between the concentration ratios of individual fatty acids to internal standard (IS, C{sub 17:0}) versus their corresponding intensity ratios were constructed for C{sub 14:0}, C{sub 16:1}, C{sub 16:0}, C{sub 18:0}, C{sub 18:1}, C{sub 18:2}, C{sub 18:3}, C{sub 20:4}, and C{sub 22:6}, respectively, in their mixture, with correlation coefficients between 0.991 and 0.999 and limits of detection (LODs) between 0.2 and 5.4 μM, along with the linear dynamic range of more than two orders of magnitude. The results indicate that the multiple point internal standard calibration could reduce the impact of ion suppression and improve quantification accuracy in the MALDI mode. The quantitative results of nine FFAs from 339 serum samples, including 161 healthy controls, 118 patients with hyperglycemia and 60 patients without hyperglycemia show that FFAs levels in hyperglycemic patient sera are significantly higher than those in healthy
Energy Technology Data Exchange (ETDEWEB)
Sacks, I.J.; Ashmore, B.C.; Alesso, H.P.
1983-07-01
Spatial and functional coupling (including human actions) of nuclear power plant systems that lead to interdependencies are called Systems Interactions. At present, the US Nuclear Regulatory Commission (NRC) is investigating ways of integrating a systems interactions study with existing Probabilistic Risk Assessment efforts. One approach is based on graph-theoretic methods utilizing matrix representations of logic diagrams called Digraph Matrix Analysis (DMA). The objective in this report is to demonstrate the capabilities of Digraph Matrix Analysis to model an accident sequence (including front-line systems, support systems and human actions) as a continuous, well-integrated logic model in order to identify and evaluate functional systems interactions. The selected accident sequence, loss of high pressure safety injection during a LOCA, was modeled and qualitative and quantitative comparisons were made to the Reactor Safety Study (WASH 1400) and other studies.
Energy Technology Data Exchange (ETDEWEB)
Sacks, I.J.; Ashmore, B.C.; Alesso, H.P.
1983-07-01
Spatial and functional coupling of nuclear power plant systems that lead to interdependencies are called Systems Interactions. At present, the US Nuclear Regulatory Commission (NRC) is investigating ways of integrating a systems interactions study with existing Probabilistic Risk Assessment efforts. One approach is based on graph-theoretic methods utilizing matrix representations of logic diagrams called Digraph Matrix Analysis (DMA). The objective in this report is to demonstrate the capabilities of Digraph Matrix Analysis to model an accident sequence (including front line systems, support systems and human actions) as a continuous, well-integrated logic model in order to identify and evaluate functional systems interactions. The selected accident sequence, loss of high pressure safety injection during an S1 LOCA, was modeled and qualitative and quantitative comparisons were made to WASH 1400 aand other studies.
Teh, Hui Boon; Li, Sam Fong Yau
2015-02-27
A new, highly sensitive and reliable two-dimensional matrix elimination ion chromatography (IC) method was developed for simultaneous detection of bromate, chlorite and five haloacetic acids. This method combined the conventional IC in first dimension with capillary IC in the second dimension coupled with suppressed conductivity detection. The first dimension utilizes a high capacity column to partially resolve matrix from target analytes. By optimizing the cut window, the target analytes were selectively cut and trapped in a trap column through the use of a six-port valve, while the separated matrix were diverted to waste. The trapped target analytes were delivered on to the capillary column for further separation and detection. Temperature programming was used to improve selectivity in second dimension column to obtain complete resolution of the target analytes. Compared to the performance of one-dimensional IC, the two-dimensional approach resulted in a significant increase in sensitivity for all target analytes with limit of detection ranging from 0.30 to 0.64μg/L and provided more reliable analysis due to second column confirmation. Good linearity was obtained for all the target analytes with correlation coefficients >0.998. The proposed method was successfully applied to the determination of oxyhalides and haloacetic acids in various matrices with recoveries ranging from 90 to 116% and RSD less than 6.1%. The method allows direct injection of samples and the use of columns with different selectivity, thus significantly reduces the level of false positive results. The method is fully automated and simple, making it practical for routine monitoring of water quality. The satisfactory results also demonstrated that the two-dimensional matrix elimination method coupled with capillary IC is a promising approach for detection of trace substances in complex matrices.
Margaris, G.; Vasilakaki, M.; Peddis, D.; Trohidou, K. N.; Laureti, S.; Binns, C.; Agostinelli, E.; Rinaldi, D.; Mathieu, R.; Fiorani, D.
2017-01-01
In nanoparticle systems consisting of two magnetic materials (bi-magnetic nanoparticles or nanoparticles embedded in a magnetic matrix), there is a constantly growing interest in the investigation of the interplay between interparticle interactions and the nanoparticle-matrix interface exchange coupling, because of its enormous impact on a number of technological applications. The understanding of the mechanisms of such interplay is a great challenge, as it would allow controlling equilibrium and non-equilibrium magnetization dynamics of exchange coupled nanoparticles systems and finely tuning their anisotropy. Here, we provide evidence that this interplay leads to a collective superspin glass (SSG) behavior in a system of diluted ferromagnetic (FM) nanoparticles embedded in an antiferromagnetic (AFM) matrix (5% volume fraction of Co particles in Mn film matrix). We have developed a novel mesoscopic model to study the influence of interparticle interaction on the exchange bias (EB) and the dynamical behavior of assemblies of FM nanoparticles embedded in a granular AFM matrix. Our mesoscopic model is based on reducing the amount of simulated spins to the minimum number necessary to describe the magnetic structure of the system and introducing the adequate exchange parameters between the different spins. The model replicates remarkably well the observed static and dynamical SSG properties as well as the EB behavior. In addition, the proposed model well explains the role of the significant Co/Mn alloying and of the granularity of the matrix in mediating interparticle interactions through exchange and dipole-dipole coupling between the uncompensated moments of its grains and the exchange interaction at the Co/Mn interface.
Arhun, Neslihan; Cehreli, Sevi Burcak
2013-01-01
Reestablishing proximal contacts with composite resins may prove challenging since the applied adhesives may lead to resin coating that produces additional thickness. The aim of this study was to investigate the surface of metal matrix bands after application of adhesive systems and blowing or wiping off the adhesive before polymerization. Seventeen groups of matrix bands were prepared. The remnant particles were characterized by energy dispersive spectrum and scanning electron microscopy. Total etch and two-step self-etch adhesives did not leave any resin residues by wiping and blowing off. All-in-one adhesive revealed resin residues despite wiping off. Prime and Bond NT did not leave any remnant with compomer. Clinicians must be made aware of the consequences of possible adhesive remnants on matrix bands that may lead to a defective definitive restoration. The adhesive resin used for Class II restorations may leave resin coats on metal matrix bands after polymerization, resulting in additional thickness on the metal matrix bands and poor quality of the proximal surface of the definitive restoration when the adhesive system is incorporated in the restoration.
Directory of Open Access Journals (Sweden)
2009-05-01
Full Text Available Poly(carboxylic acid-polysaccharide compositions have been found suitable for obtaining drug formulations with controlled release, most formulations being therapeutically efficacious, stable, and non-irritant. The influence of the characteristics of the aqueous solutions from which the polymer matrix is prepared (i.e. the total concentration of polymer in solutions and the mixing ratio between the partners, hydroxypropyl cellulose, HPC and maleic acid-alternating-styrene copolymer, MAc-alt-S on the kinetics of some drugs release in acidic environment (pH = 2 has been followed by ‘in vitro’ dissolution tests. It has been established that the kinetics of procaine hydrochloride release from HPC/MAc-alt-S matrix depends on its composition; the diffusion exponent, n is close to 0.5 for matrices where one of the components is in large excess and n~0.02 for middle composition range. The lower value of diffusion exponent for middle composition range could be caused by the so called ‘burst effect’, therefore the kinetic evaluation is difficult.
Wu, Qian; Comi, Troy J; Li, Bin; Rubakhin, Stanislav S; Sweedler, Jonathan V
2016-06-07
Matrix-assisted laser desorption/ionization (MALDI) mass spectrometry imaging (MSI) is used for the multiplex detection and characterization of diverse analytes over a wide mass range directly from tissues. However, analyte coverage with MALDI MSI is typically limited to the more abundant compounds, which have m/z values that are distinct from MALDI matrix-related ions. On-tissue analyte derivatization addresses these issues by selectively tagging functional groups specific to a class of analytes, while simultaneously changing their molecular masses and improving their desorption and ionization efficiency. We evaluated electrospray deposition of liquid-phase derivatization agents as a means of on-tissue analyte derivatization using 2-picolylamine; we were able to detect a range of endogenous fatty acids with MALDI MSI. When compared with airbrush application, electrospray led to a 3-fold improvement in detection limits and decreased analyte delocalization. Six fatty acids were detected and visualized from rat cerebrum tissue using a MALDI MSI instrument operating in positive mode. MALDI MSI of the hippocampal area allowed targeted fatty acid analysis of the dentate gyrus granule cell layer and the CA1 pyramidal layer with a 20-μm pixel width, without degrading the localization of other lipids during liquid-phase analyte derivatization.
Choi, Jiyeon; Jang, Bu Nam; Park, Bang Ju; Joung, Yoon Ki; Han, Dong Keun
2014-08-26
Sirolimus (SRL) release from the biodegradable poly(l-lactic-co-glycolic acid) (PLGA) matrix was investigated for the application of drug-eluting stents (DES). In particular, this study focused on whether various organic solvents affect the interaction between SRL and PLGA and the formation of microstructures during ultrasonic coating. The SRL-loaded PLGA coated by tetrahydrofuran or acetone showed a significant initial burst, whereas that from acetonitrile was constantly released during a period of 21 days. On the basis of these results, the interactions at the molecular level of SRL with the polymer matrix were estimated according to various organic solvents. Although the topographies of the coated surface were obviously different, the correlation between surface roughness and SRL release was very poor. Irrespective of organic solvents, FT-IR data showed significantly weak SRL-PLGA interactions. From the result of wide-angle X-ray diffraction, it was confirmed that SRL was dispersed in an amorphous state in the polymer matrix after ultrasonic coating. The glass-transition temperature was also influenced by organic solvents, resulting in a plasticizing effect. The particle size of SRL appeared to determine the release profile from the PLGA matrix, which was the combination of diffusion and polymer degradation at an SRL size of more than 800 nm and the Fickian release at that of less than 300 nm. Therefore, organic solvents can lead to a heterogeneous microstructure in the SRL-loaded PLGA matrix, which is at or near the surface, consisting of aggregated drug- and polymer-rich regions. It is expected that the drug release can be controlled by physicochemical properties of organic solvents, and this study can be used effectively for localized drug release in biomedical devices such as drug-eluting stents.
D-Amino Acids in the Nervous and Endocrine Systems
Directory of Open Access Journals (Sweden)
Yoshimitsu Kiriyama
2016-01-01
Full Text Available Amino acids are important components for peptides and proteins and act as signal transmitters. Only L-amino acids have been considered necessary in mammals, including humans. However, diverse D-amino acids, such as D-serine, D-aspartate, D-alanine, and D-cysteine, are found in mammals. Physiological roles of these D-amino acids not only in the nervous system but also in the endocrine system are being gradually revealed. N-Methyl-D-aspartate (NMDA receptors are associated with learning and memory. D-Serine, D-aspartate, and D-alanine can all bind to NMDA receptors. H2S generated from D-cysteine reduces disulfide bonds in receptors and potentiates their activity. Aberrant receptor activity is related to diseases of the central nervous system (CNS, such as Alzheimer’s disease, amyotrophic lateral sclerosis, and schizophrenia. Furthermore, D-amino acids are detected in parts of the endocrine system, such as the pineal gland, hypothalamus, pituitary gland, pancreas, adrenal gland, and testis. D-Aspartate is being investigated for the regulation of hormone release from various endocrine organs. Here we focused on recent findings regarding the synthesis and physiological functions of D-amino acids in the nervous and endocrine systems.
Pototzky, Anthony S.
2008-01-01
A simple matrix polynomial approach is introduced for approximating unsteady aerodynamics in the s-plane and ultimately, after combining matrix polynomial coefficients with matrices defining the structure, a matrix polynomial of the flutter equations of motion (EOM) is formed. A technique of recasting the matrix-polynomial form of the flutter EOM into a first order form is also presented that can be used to determine the eigenvalues near the origin and everywhere on the complex plane. An aeroservoelastic (ASE) EOM have been generalized to include the gust terms on the right-hand side. The reasons for developing the new matrix polynomial approach are also presented, which are the following: first, the "workhorse" methods such as the NASTRAN flutter analysis lack the capability to consistently find roots near the origin, along the real axis or accurately find roots farther away from the imaginary axis of the complex plane; and, second, the existing s-plane methods, such as the Roger s s-plane approximation method as implemented in ISAC, do not always give suitable fits of some tabular data of the unsteady aerodynamics. A method available in MATLAB is introduced that will accurately fit generalized aerodynamic force (GAF) coefficients in a tabular data form into the coefficients of a matrix polynomial form. The root-locus results from the NASTRAN pknl flutter analysis, the ISAC-Roger's s-plane method and the present matrix polynomial method are presented and compared for accuracy and for the number and locations of roots.
Directory of Open Access Journals (Sweden)
Athanasios A. Pantelous
2010-01-01
Full Text Available In some interesting applications in control and system theory, linear descriptor (singular matrix differential equations of higher order with time-invariant coefficients and (non- consistent initial conditions have been used. In this paper, we provide a study for the solution properties of a more general class of the Apostol-Kolodner-type equations with consistent and nonconsistent initial conditions.
DEFF Research Database (Denmark)
Cao, Qian; Song, Y. D.; Guerrero, Josep M.;
2016-01-01
This paper proposes a distributed algorithm for coordination of flywheel energy storage matrix system (FESMS) cooperated with wind farm. A simple and distributed ratio consensus algorithm is proposed to solve FESMS dispatch problem. The algorithm is based on average consensus for both undirected...
Directory of Open Access Journals (Sweden)
Ashis De
2014-01-01
Full Text Available In this paper a detailed comparison between the estimation results of unknown inputs of a linear time invariant system using projection operator approach and using the method of generalized matrix inverse have been discussed. The full order observer constructed using projection operator approach has been extended and implemented for this purpose.
Directory of Open Access Journals (Sweden)
Salem Abdelmalek
2014-11-01
Full Text Available In this article we construct the invariant regions for m-component reaction-diffusion systems with a tridiagonal symmetric Toeplitz matrix of diffusion coefficients and with nonhomogeneous boundary conditions. We establish the existence of global solutions, and use Lyapunov functional methods. The nonlinear reaction term is assumed to be of polynomial growth.
Wirsching, E.; Loomans, B.A.C.; Klaiber, B.; Dorfer, C.E.
2011-01-01
OBJECTIVES: To investigate the influence of cavity preparation (MO/DO/MOD) and type of matrix system on proximal contact tightness of direct posterior composite restorations. MATERIALS AND METHODS: 85 patients in need of a two- or three surface Class II direct composite restoration were randomly div
Concentric Gel System to Study the Biophysical Role of Matrix Microenvironment on 3D Cell Migration
Kurniawan, Nicholas Agung; Chaudhuri, Parthiv Kant; Lim, Chwee Teck
2015-01-01
The ability of cells to migrate is crucial in a wide variety of cell functions throughout life from embryonic development and wound healing to tumor and cancer metastasis. Despite intense research efforts, the basic biochemical and biophysical principles of cell migration are still not fully understood, especially in the physiologically relevant three-dimensional (3D) microenvironments. Here, we describe an in vitro assay designed to allow quantitative examination of 3D cell migration behaviors. The method exploits the cell’s mechanosensing ability and propensity to migrate into previously unoccupied extracellular matrix (ECM). We use the invasion of highly invasive breast cancer cells, MDA-MB-231, in collagen gels as a model system. The spread of cell population and the migration dynamics of individual cells over weeks of culture can be monitored using live-cell imaging and analyzed to extract spatiotemporally-resolved data. Furthermore, the method is easily adaptable for diverse extracellular matrices, thus offering a simple yet powerful way to investigate the role of biophysical factors in the microenvironment on cell migration. PMID:25867104
Blade system design studies volume II : preliminary blade designs and recommended test matrix.
Energy Technology Data Exchange (ETDEWEB)
Griffin, Dayton A. (Global Energy Concepts, LLC, Kirkland, WA)
2004-06-01
As part of the U.S. Department of Energy's Wind Partnerships for Advanced Component Technologies (WindPACT) program, Global Energy Concepts, LLC is performing a Blade System Design Study (BSDS) concerning innovations in materials, processes and structural configurations for application to wind turbine blades in the multi-megawatt range. The BSDS Volume I project report addresses issues and constraints identified to scaling conventional blade designs to the megawatt size range, and evaluated candidate materials, manufacturing and design innovations for overcoming and improving large blade economics. The current report (Volume II), presents additional discussion of materials and manufacturing issues for large blades, including a summary of current trends in commercial blade manufacturing. Specifications are then developed to guide the preliminary design of MW-scale blades. Using preliminary design calculations for a 3.0 MW blade, parametric analyses are performed to quantify the potential benefits in stiffness and decreased gravity loading by replacement of a baseline fiberglass spar with carbon-fiberglass hybrid material. Complete preliminary designs are then presented for 3.0 MW and 5.0 MW blades that incorporate fiberglass-to-carbon transitions at mid-span. Based on analysis of these designs, technical issues are identified and discussed. Finally, recommendations are made for composites testing under Part I1 of the BSDS, and the initial planned test matrix for that program is presented.
Sharma, Sandeep
2015-01-01
We propose a multireference linearized coupled cluster theory using matrix product states (MPS-LCC) which provides remarkably accurate ground-state energies, at a computational cost that has the same scaling as multireference configuration interaction singles and doubles (MRCISD), for a wide variety of electronic Hamiltonians. These range from first-row dimers at equilibrium and stretched geometries, to highly multireference systems such as the chromium dimer and lattice models such as periodic two-dimensional 1-band and 3-band Hubbard models. The MPS-LCC theory shows a speed up of several orders of magnitude over the usual DMRG algorithm while delivering energies in excellent agreement with converged DMRG calculations. Also, in all the benchmark calculations presented here MPS-LCC outperformed the commonly used multi-reference quantum chemistry methods in some cases giving energies in excess of an order of magnitude more accurate. As a size-extensive method that can treat large active spaces, MPS-LCC opens u...
Singular-potential random-matrix model arising in mean-field glassy systems.
Akemann, Gernot; Villamaina, Dario; Vivo, Pierpaolo
2014-06-01
We consider an invariant random matrix ensemble where the standard Gaussian potential is distorted by an additional single pole of arbitrary fixed order. Potentials with first- and second-order poles have been considered previously and found applications in quantum chaos and number theory. Here we present an application to mean-field glassy systems. We derive and solve the loop equation in the planar limit for the corresponding class of potentials. We find that the resulting mean or macroscopic spectral density is generally supported on two disconnected intervals lying on the two sides of the repulsive pole, whose edge points can be completely determined imposing the additional constraint of traceless matrices on average. For an unbounded potential with an attractive pole, we also find a possible one-cut solution for certain values of the couplings, which is ruled out when the traceless condition is imposed. Motivated by the calculation of the distribution of the spin-glass susceptibility in the Sherrington-Kirkpatrick spin-glass model, we consider in detail a second-order pole for a zero-trace model and provide the most explicit solution in this case. In the limit of a vanishing pole, we recover the standard semicircle. Working in the planar limit, our results apply to matrices with orthogonal, unitary, and symplectic invariance. Numerical simulations and an independent analytical Coulomb fluid calculation for symmetric potentials provide an excellent confirmation of our results.
The Spin Density Matrix II: Application to a system of two quantum dots
Kunikeev, Sharif D
2007-01-01
This work is a sequel to our work "The Spin Density Matrix I: General Theory and Exact Master Equations" (eprint cond-mat/0708.0644). Here we compare pure- and pseudo-spin dynamics using as an example a system of two quantum dots, a pair of localized conduction-band electrons in an n-doped GaAs semiconductor. Pure-spin dynamics is obtained by tracing out the orbital degrees of freedom, whereas pseudo-spin dynamics retains (as is conventional) an implicit coordinate dependence. We show that magnetic field inhomogeneity and spin-orbit interaction result in a non-unitary evolution in pure-spin dynamics, whereas these interactions contribute to the effective pseudo-spin Hamiltonian via terms that are asymmetric in spin permutations, in particular, the Dzyaloshinskii-Moriya (DM) spin-orbit interaction. We numerically investigate the non-unitary effects in the dynamics of the triplet states population, purity, and Lamb energy shift, as a function of interdot distance and magnetic field difference. The spin-orbit in...
Bakun, M; Senatorski, G; Rubel, T; Lukasik, A; Zielenkiewicz, P; Dadlez, M; Paczek, L
2014-02-01
Aging is a complex physiological process that poses considerable conundrums to rapidly aging societies. For example, the risk of dying from cardiovascular diseases and/or cancer steadily declines for people after their 60s, and other causes of death predominate for seniors older than 80 years of age. Thus, physiological aging presents numerous unanswered questions, particularly with regard to changing metabolic patterns. Urine proteomics analysis is becoming a non-invasive and reproducible diagnostic method. We investigated the urine proteomes in healthy elderly people to determine which metabolic processes were weakened or strengthened in aging humans. Urine samples from 37 healthy volunteers aged 19-90 years (19 men, 18 women) were analyzed for protein expression by liquid chromatography-tandem mass spectrometry. This generated a list of 19 proteins that were differentially expressed in different age groups (young, intermediate, and old age). In particular, the oldest group showed protein changes reflective of altered extracellular matrix turnover and declining immune function, in which changes corresponded to reported changes in cardiovascular tissue remodeling and immune disorders in the elderly. Thus, urinary proteome changes in the elderly appear to reflect the physiological processes of aging and are particularly clearly represented in the circulatory and immune systems. Detailed identification of "protein trails" creates a more global picture of metabolic changes that occur in the elderly.
Haylock-Jacobs, Sarah; Keough, Michael B; Lau, Lorraine; Yong, V Wee
2011-10-01
The extracellular matrix (ECM) is a complex network of scaffolding molecules that also plays an important role in cell signalling, migration and tissue structure. In the central nervous system (CNS), the ECM is integral to the efficient development/guidance and survival of neurons and axons. However, changes in distribution of the ECM in the CNS may significantly enhance pathology in CNS disease or following injury. One group of ECM proteins that is important for CNS homeostasis is the chondroitin sulphate proteoglycans (CSPGs). Up-regulation of these molecules has been demonstrated to be both desirable and detrimental following CNS injury. Taking cues from arthritis, where there is a strong anti-CSPG immune response, there is evidence that suggests that CSPGs may influence immunity during CNS pathological conditions. This review focuses on the role of CSPGs in CNS pathologies as well as in immunity, both from a viewpoint of how they may inhibit repair and exacerbate damage in the CNS, and how they are involved in activation and function of peripheral immune cells, particularly in multiple sclerosis. Lastly, we address how CSPGs may be manipulated to improve disease outcomes.
Fast and accurate generation method of PSF-based system matrix for PET reconstruction
Sun, Xiao-Li; Liu, Shuang-Quan; Yun, Ming-Kai; Li, Dao-Wu; Gao, Juan; Li, Mo-Han; Chai, Pei; Tang, Hao-Hui; Zhang, Zhi-Ming; Wei, Long
2017-04-01
This work investigates the positional single photon incidence response (P-SPIR) to provide an accurate point spread function (PSF)-contained system matrix and its incorporation within the image reconstruction framework. Based on the Geant4 Application for Emission Tomography (GATE) simulation, P-SPIR theory takes both incidence angle and incidence position of the gamma photon into account during crystal subdivision, instead of only taking the former into account, as in single photon incidence response (SPIR). The response distribution obtained in this fashion was validated using Monte Carlo simulations. In addition, two-block penetration and normalization of the response probability are introduced to improve the accuracy of the PSF. With the incorporation of the PSF, the homogenization model is then analyzed to calculate the spread distribution of each line-of-response (LOR). A primate PET scanner, Eplus-260, developed by the Institute of High Energy Physics, Chinese Academy of Sciences (IHEP), was employed to evaluate the proposed method. The reconstructed images indicate that the P-SPIR method can effectively mitigate the depth-of-interaction (DOI) effect, especially at the peripheral area of field-of-view (FOV). Furthermore, the method can be applied to PET scanners with any other structures and list-mode data format with high flexibility and efficiency. Supported by National Natural Science Foundation of China (81301348) and China Postdoctoral Science Foundation (2015M570154)
Singular-potential random-matrix model arising in mean-field glassy systems
Akemann, Gernot; Villamaina, Dario; Vivo, Pierpaolo
2014-06-01
We consider an invariant random matrix ensemble where the standard Gaussian potential is distorted by an additional single pole of arbitrary fixed order. Potentials with first- and second-order poles have been considered previously and found applications in quantum chaos and number theory. Here we present an application to mean-field glassy systems. We derive and solve the loop equation in the planar limit for the corresponding class of potentials. We find that the resulting mean or macroscopic spectral density is generally supported on two disconnected intervals lying on the two sides of the repulsive pole, whose edge points can be completely determined imposing the additional constraint of traceless matrices on average. For an unbounded potential with an attractive pole, we also find a possible one-cut solution for certain values of the couplings, which is ruled out when the traceless condition is imposed. Motivated by the calculation of the distribution of the spin-glass susceptibility in the Sherrington-Kirkpatrick spin-glass model, we consider in detail a second-order pole for a zero-trace model and provide the most explicit solution in this case. In the limit of a vanishing pole, we recover the standard semicircle. Working in the planar limit, our results apply to matrices with orthogonal, unitary, and symplectic invariance. Numerical simulations and an independent analytical Coulomb fluid calculation for symmetric potentials provide an excellent confirmation of our results.
Mounier, S; Nicolodelli, G; Redon, R; Milori, D M B P
2017-04-15
The front face fluorescence spectroscopy is often used to quantify chemicals in well-known matrices as it is a rapid and powerful technique, with no sample preparation. However it was not used to investigate extracted organic matter like humic substances. This work aims to fully investigate for the first time front face fluorescence spectroscopy response of a ternary system including boric acid, tryptophan and humic substances, and two binaries system containing quinine sulfate or humic substance in boric acid. Pure chemicals, boric acid, tryptophan, quinine sulfate and humic acid were mixed together in solid pellet at different contents from 0 to 100% in mass. The measurement of excitation emission matrix of fluorescence (3D fluorescence) and laser induced fluorescence were then done in the front face mode. Fluorescence matrices were decomposed using the CP/PARAFAC tools after scattering treatments. Results show that for 3D fluorescence there is no specific component for tryptophan and quinine sulfate, and that humic substances lead to a strong extinction effect for mixture containing quinine sulfate. Laser induced fluorescence gives a very good but non-specific related response for both quinine sulfate and tryptophan. No humic substances fluorescence response was found, but extinction effect is observed as for 3D fluorescence. This effect is stronger for quinine sulfate than for tryptophan. These responses were modeled using a simple absorbance versus emission model.
Mounier, S.; Nicolodelli, G.; Redon, R.; Milori, D. M. B. P.
2017-04-01
The front face fluorescence spectroscopy is often used to quantify chemicals in well-known matrices as it is a rapid and powerful technique, with no sample preparation. However it was not used to investigate extracted organic matter like humic substances. This work aims to fully investigate for the first time front face fluorescence spectroscopy response of a ternary system including boric acid, tryptophan and humic substances, and two binaries system containing quinine sulfate or humic substance in boric acid. Pure chemicals, boric acid, tryptophan, quinine sulfate and humic acid were mixed together in solid pellet at different contents from 0 to 100% in mass. The measurement of excitation emission matrix of fluorescence (3D fluorescence) and laser induced fluorescence were then done in the front face mode. Fluorescence matrices were decomposed using the CP/PARAFAC tools after scattering treatments. Results show that for 3D fluorescence there is no specific component for tryptophan and quinine sulfate, and that humic substances lead to a strong extinction effect for mixture containing quinine sulfate. Laser induced fluorescence gives a very good but non-specific related response for both quinine sulfate and tryptophan. No humic substances fluorescence response was found, but extinction effect is observed as for 3D fluorescence. This effect is stronger for quinine sulfate than for tryptophan. These responses were modeled using a simple absorbance versus emission model.
Lam, P-L; Gambari, R; Kok, S H-L; Lam, K-H; Tang, J C-O; Bian, Z-X; Lee, K K-H; Chui, C-H
2015-02-01
Aspergillus niger (A. niger) is a common species of Aspergillus molds. Cutaneous aspergillosis usually occurs in skin sites near intravenous injection and approximately 6% of cutaneous aspergillosis cases which do not involve burn or HIV-infected patients are caused by A. niger. Biomaterials and biopharmaceuticals produced from microparticle-based drug delivery systems have received much attention as microencapsulated drugs offer an improvement in therapeutic efficacy due to better human absorption. The frequently used crosslinker, glutaraldehyde, in gelatin-based microencapsulation systems is considered harmful to human beings. In order to tackle the potential risks, agarose has become an alternative polymer to be used with gelatin as wall matrix materials of microcapsules. In the present study, we report the eco-friendly use of an agarose/gelatin-based microencapsulation system to enhance the antifungal activity of gallic acid and reduce its potential cytotoxic effects towards human skin keratinocytes. We used optimal parameter combinations, such as an agarose/gelatin ratio of 1:1, a polymer/oil ratio of 1:60, a surfactant volume of 1% w/w and a stirring speed of 900 rpm. The minimum inhibitory concentration of microencapsulated gallic acid (62.5 µg/ml) was significantly improved when compared with that of the original drug (>750 µg/ml). The anti-A. niger activity of gallic acid -containing microcapsules was much stronger than that of the original drug. Following 48 h of treatment, skin cell survival was approximately 90% with agarose/gelatin microcapsules containing gallic acid, whereas cell viability was only 25-35% with free gallic acid. Our results demonstrate that agarose/gelatin-based microcapsules containing gallic acid may prove to be helpful in the treatment of A. niger-induced skin infections near intravenous injection sites.
Directory of Open Access Journals (Sweden)
Millward Jason M
2007-09-01
Full Text Available Abstract Background Matrix metalloproteinases (MMPs are thought to mediate cellular infiltration in central nervous system (CNS inflammation by cleaving extracellular matrix proteins associated with the blood-brain barrier. The family of MMPs includes 23 proteinases, including six membrane type-MMPs (MT-MMPs. Leukocyte infiltration is an integral part of the pathogenesis of autoimmune inflammation in the CNS, as occurs in multiple sclerosis and its animal model experimental autoimmune encephalomyelitis (EAE, as well as in the response to brain trauma and injury. We have previously shown that gene expression of the majority of MMPs was upregulated in the spinal cord of SJL mice with severe EAE induced by adoptive transfer of myelin basic protein-reactive T cells, whereas four of the six MT-MMPs (MMP-15, 16, 17 and 24 were downregulated. The two remaining MT-MMPs (MMP-14 and 25 were upregulated in whole tissue. Methods We used in vivo models of CNS inflammation and injury to study expression of MT-MMP and cytokine mRNA by real-time RT-PCR. Expression was also assessed in microglia sorted from CNS by flow cytometry, and in primary microglia cultures following treatment with IFNγ. Results We now confirm the expression pattern of MT-MMPs in the B6 mouse, independent of effects of adjuvant. We further show expression of all the MT-MMPs, except MMP-24, in microglia. Microglia isolated from mice with severe EAE showed statistically significant downregulation of MMP-15, 17 and 25 and lack of increase in levels of other MT-MMPs. Downregulation of MT-MMPs was also apparent following CNS injury. The pattern of regulation of MT-MMPs in neuroinflammation showed no association with expression of the proinflammatory cytokines TNFα, IL-1β, or IFNγ. Conclusion CNS inflammation and injury leads to downregulation in expression of the majority of MT-MMPs. Microglia in EAE showed a general downregulation of MT-MMPs, and our findings suggest that MT-MMP levels may
DEFF Research Database (Denmark)
Mariotti, María; Granby, Kit; Fromberg, Arvid
2012-01-01
Furan, a potential carcinogen, has been detected in highly consumed starchy foods, such as bread and snacks; however, research on furan generation in these food matrixes has not been undertaken, thus far. The present study explored the effect of ascorbic acid addition and cooking methods (frying...... and baking) over furan occurrence and its relation with the non-enzymatic browning in a wheat flour starchy food model system. Results showed that furan generation significantly increased in the presence of ascorbic acid after 7 min of heating (p
Boisson, F.; Bekaert, V.; Brasse, D.
2016-03-01
Nowadays, Single Photon imaging has become an essential part of molecular imaging and nuclear medicine. Whether to establish a diagnosis or in the therapeutic monitoring, this modality presents performance that continues to improve. For over 50 years, several collimators have been proposed. Mainly governed by collimation parameters, the resolution-sensitivity trade-off is the factor determining the collimator the most suitable for an intended study. One alternative to the common approaches is the rotating slat collimator (RSC). In the present study, we are aiming at developing a preclinical system equipped with a RSC dedicated to mice and rats imaging, which requires both high sensitivity and spatial resolution. We investigated the resolution-sensitivity trade-offs obtained by varying different collimation parameters: (i) the slats height (H), and (ii) the gap between two consecutive slats (g), considering different intrinsic spatial resolutions. One system matrix was generated for each set of collimation parameters (H,g). Spatial resolutions, Signal-to-Noise Ratio (SNR) and sensitivity obtained for all the set of collimation parameters (H,g) were measured in the 2D projections reconstructed with ML-EM. According to our results, 20 mm high slats and a 1 mm gap were chosen as a good RSC candidate for a preclinical detection module. This collimator will ensure a sensitivity greater than 0.2% and a system spatial resolution below 1 mm, considering an intrinsic spatial resolution below 0.8 mm.
Anastasia, Davide
2011-01-01
The generic matrix multiply (GEMM) function is the core element of high-performance linear algebra libraries used in many computationally-demanding digital signal processing (DSP) systems. We propose an acceleration technique for GEMM based on dynamically adjusting the imprecision (distortion) of computation. Our technique employs adaptive scalar companding and rounding to input matrix blocks followed by two forms of packing in floating-point that allow for concurrent calculation of multiple results. Since the adaptive companding process controls the increase of concurrency (via packing), the increase in processing throughput (and the corresponding increase in distortion) depends on the input data statistics. To demonstrate this, we derive the optimal throughput-distortion control framework for GEMM for the broad class of zero-mean, independent identically distributed, input sources. Our approach converts matrix multiplication in programmable processors into a computation channel: when increasing the processi...
Gabboun, N H; Najib, N M; Ibrahim, H G; Assaf, S
2001-01-01
Release of salicylic acid, diclofenac acid, diclofenac diethylamine and diclofenac sodium, from lyotropic structured systems, namely; neat and middle liquid crystalline phases, across mid-dorsal hairless rat skin into aqueous buffer were studied. Release results were compared with those from the isotropic systems. The donor systems composed of the surfactant polyoxyethylene (20) isohexadecyl ether, HCl buffer of pH 1 or distilled water and the specific drug. High performance liquid chromatography (HPLC) methods were used to monitor the transfer of the drugs across the skin barrier. Results indicated that the rate-determining step in the transport process was the release of the drug from the specified donor system. Further, apparent zero order release was demonstrated with all systems. Except for diclofenac sodium, drug fluxes decreased as the donor medium changed from isotropic to anisotropic. The decrease in fluxes was probably due to the added constrains on the movement of drug molecules. By changing the anisotropic donor medium from neat to middle phase, drug flux decreased in case of salicylic acid and diclofenac sodium. In the mean time, flux increased in case of the diethylamine salt and appeared nearly similar in case of diclofenac acid. Rates of drug transfer across the skin from the anisotropic donors seemed to be largely controlled by the entropy contribution to the transport process. The type and extent of drug-liquid crystal interactions probably influenced the latter.
Energy Technology Data Exchange (ETDEWEB)
Shakib-Manesh, T.E.; Hirvonen, K.O.; Jalava, K.J.; Ålander, T.; Kuitunen, M.T., E-mail: markku.kuitunen@jyu.fi
2014-11-15
Environmental impacts of small scale projects are often assessed poorly, or not assessed at all. This paper examines the usability of the Rapid Impact Assessment Matrix (RIAM) as a tool to prioritize project proposals for small scale water restoration projects in relation to proposals' potential to improve the environment. The RIAM scoring system was used to assess and rank the proposals based on their environmental impacts, the costs of the projects to repair the harmful impacts, and the size of human population living around the sites. A four-member assessment group (The expert panel) gave the RIAM-scores to the proposals. The assumed impacts of the studied projects at the Eastern Finland water systems were divided into the ecological and social impacts. The more detailed assessment categories of the ecological impacts in this study were impacts on landscape, natural state, and limnology. The social impact categories were impacts to recreational use of the area, fishing, industry, population, and economy. These impacts were scored according to their geographical and social significance, their magnitude of change, their character, permanence, reversibility, and cumulativeness. The RIAM method proved to be an appropriate and recommendable method for the small-scale assessment and prioritizing of project proposals. If the assessments are well documented, the RIAM can be a method for easy assessing and comparison of the various kinds of projects. In the studied project proposals there were no big surprises in the results: the best ranks were received by the projects, which were assumed to return watersheds toward their original state.
A computerised system for the identification of lactic acid bacteria.
Wijtzes, T.; Bruggeman, M.R.; Nout, M.J.R.; Zwietering, M.H.
1997-01-01
A generic computerised system for the identification of bacteria was developed. The system is equipped with a key to the identification of lactic acid bacteria. The identification is carried out in two steps. The first step distinguishes groups of bacteria by following a decision tree with general i
21 CFR 862.1290 - Fatty acids test system.
2010-04-01
... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Fatty acids test system. 862.1290 Section 862.1290 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test Systems § 862...
21 CFR 862.1320 - Gastric acidity test system.
2010-04-01
... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Gastric acidity test system. 862.1320 Section 862.1320 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test Systems §...
21 CFR 862.1295 - Folic acid test system.
2010-04-01
... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Folic acid test system. 862.1295 Section 862.1295 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test Systems §...
21 CFR 862.1095 - Ascorbic acid test system.
2010-04-01
... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ascorbic acid test system. 862.1095 Section 862.1095 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test Systems §...
Microbial Nucleic Acid Sensing in Oral and Systemic Diseases.
Crump, K E; Sahingur, S E
2016-01-01
One challenge in studying chronic infectious and inflammatory disorders is understanding how host pattern recognition receptors (PRRs), specifically toll-like receptors (TLRs), sense and respond to pathogen- or damage-associated molecular patterns, their communication with each other and different components of the immune system, and their role in propagating inflammatory stages of disease. The discovery of innate immune activation through nucleic acid recognition by intracellular PRRs such as endosomal TLRs (TLR3, TLR7, TLR8, and TLR9) and cytoplasmic proteins (absent in melanoma 2 and DNA-dependent activator of interferon regulatory factor) opened a new paradigm: Nucleic acid sensing is now implicated in multiple immune and inflammatory conditions (e.g., atherosclerosis, cancer), viral (e.g., human papillomavirus, herpes virus) and bacterial (e.g., Helicobacter pylori, pneumonia) diseases, and autoimmune disorders (e.g., systemic lupus erythematosus, rheumatoid arthritis). Clinical investigations reveal the overexpression of specific nucleic acid sensors in diseased tissues. In vivo animal models show enhanced disease progression associated with receptor activation. The involvement of nucleic acid sensors in various systemic conditions is further supported by studies reporting receptor knockout mice being either protected from or prone to disease. TLR9-mediated inflammation is also implicated in periodontal diseases. Considering that persistent inflammation in the oral cavity is associated with systemic diseases and that oral microbial DNA is isolated at distal sites, nucleic acid sensing may potentially be a link between oral and systemic diseases. In this review, we discuss recent advances in how intracellular PRRs respond to microbial nucleic acids and emerging views on the role of nucleic acid sensors in various systemic diseases. We also highlight new information on the role of intracellular PRRs in the pathogenesis of oral diseases including periodontitis
Optimal Pole Assignment of Linear Systems by the Sylvester Matrix Equations
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Hua-Feng He
2014-01-01
class of linear matrix equations, necessary and sufficient conditions for the existence of a solution to the optimal pole assignment problem are proposed in this paper. By properly choosing the free parameters in the parametric solutions to this class of linear matrix equations, complete solutions to the optimal pole assignment problem can be obtained. A numerical example is used to illustrate the effectiveness of the proposed approach.
Souza, Luiz C. G.; Bigot, P.
2016-10-01
One of the most well-known techniques of optimal control is the theory of Linear Quadratic Regulator (LQR). This method was originally applied only to linear systems but has been generalized for non-linear systems: the State Dependent Riccati Equation (SDRE) technique. One of the advantages of SDRE is that the weight matrix selection is the same as in LQR. The difference is that weights are not necessarily constant: they can be state dependent. Then, it gives an additional flexibility to design the control law. Many are applications of SDRE for simulation or real time control but generally SDRE weights are chosen constant so no advantage of this flexibility is taken. This work serves to show through simulation that state dependent weights matrix can improve SDRE control performance. The system is a non-linear flexible rotatory beam. In a brief first part SDRE theory will be explained and the non-linear model detailed. Then, influence of SDRE weight matrix associated with the state Q will be analyzed to get some insight in order to assume a state dependent law. Finally, these laws are tested and compared to constant weight matrix Q. Based on simulation results; one concludes showing the benefits of using an adaptive weight Q rather than a constant one.
Guan, Xiaoning; Liu, Bo; Zhang, Lijia; Xin, Xiangjun; Tian, Qinghua; Zhang, Qi; Tian, Feng; Li, Dengao; Zhao, Jumin; Wang, Renfan
2016-10-01
A novel training sequence is designed for the space division multiplexed fiber-optic transmission system in this paper. The training block is consisting of segmented sequence, which can be used to compensate time offset and distortion (such as dispersion) in the transmission link. The channel function can be obtained by one tap equalization in the receiver side. This paper designs the training sequence by adjusting the length of the training signals and implementing matrix transformation, to obtain the coefficient of equalizer for channel detect and equalization. This new training sequence reduces system complexity and improves transmission efficiency at the same time. Compared with blind equalization, the matrix transformation based training sequence can reduce system complexity, and perform targeted equalization to the mechanism of mode coupling in the space division optical fiber system. As a result, it can effectively improve signal transmission quality and reduce bit error rate.
Gou, Li-Dan; Xue, Kang; Wang, Gang-Cheng
2011-02-01
We present a 9 × 9 S-matrix and E-matrix. A representation of specialized Birman—Wenzl—Murakami algebra is obtained. Starting from the given braid group representation S-matrix, we obtain the trigonometric solution of Yang-Baxter equation. A unitary matrix Ř(x, ϕ1,ϕ2) is generated via the Yang—Baxterization approach. Then we construct a Yang—Baxter Hamiltonian through the unitary matrix Ř(x, ϕ1,ϕ2). Berry phase of this Yang—Baxter system is investigated in detail.
Directory of Open Access Journals (Sweden)
McKeown-Longo Paula J
2006-03-01
Full Text Available Abstract Background Plasminogen activators are known to play a key role in the remodeling of bone matrix which occurs during tumor progression, bone metastasis and bone growth. Dysfunctional remodeling of bone matrix gives rise to the osteoblastic and osteolytic lesions seen in association with metastatic cancers. The molecular mechanisms responsible for the development of these lesions are not well understood. Studies were undertaken to address the role of the plasminogen activator system in the regulation of fibronectin matrix assembly in the osteoblast-like cell line, MG-63. Results Treatment of MG-63 cells with P25, a peptide ligand for uPAR, resulted in an increase in assembly of fibronectin matrix which was associated with an increase in the number of activated β1 integrins on the cell surface. Overexpression of uPAR in MG-63 cells increased the effect of P25 on fibronectin matrix assembly and β1 integrin activation. P25 had no effect on uPAR null fibroblasts, confirming a role for uPAR in this process. The addition of plasminogen activator inhibitor Type I (PAI-1 to cells increased the P25-induced fibronectin polymerization, as well as the number of activated integrins. This positive regulation of PAI-1 on fibronectin assembly was independent of PAI-1's anti-proteinase activity, but acted through PAI-1 binding to the somatomedin B domain of vitronectin. Conclusion These results indicate that vitronectin modulates fibronectin matrix assembly in osteosarcoma cells through a novel mechanism involving cross-talk through the plasminogen activator system.
Extraction of L-Aspartic Acid with Reverse Micelle System
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Özlem AYDOĞAN
2009-02-01
Full Text Available The aim of this study is to investigate the extraction L-aspartic acid which is a hydrophobic amino acid with reverse micelle system. Production of amino acids by fermentation has been more important in recent years. These amino acids are obtained in dilute aqueous solutions and have to be separated from excess substrate, inorganic salts and by-products. Recently, separation of amino acids from fermentation media by reverse micelle extraction has received a great deal of attention. In this study, reverse micelle phase includes aliquat-336 as a surfactant, 1-decanol as a co-surfactant and isooctane as an apolar solvent. Experiments were performed at 150 rpm stirring rate, at 30 oC, for 30 min extraction time with equal volumes of reverse micelle and aqueous phases. Concentration of L-aspartic acid was analyzed by liquid chromatography (HPLC. The extraction yield increased with increasing pH and aliquat-336 concentration and with decreasing initial amino acid concentration. Maximum ekstraction yield (68 % was obtained at pH of 12, surfactant concentration of 200 mM and an initial amino acid concentration of 5 mM.
Hwang, Hye Jin; Park, Hyen Joo; Chung, Hwa-Jin; Min, Hye-Young; Park, Eun-Jung; Hong, Ji-Young; Lee, Sang Kook
2006-05-01
Caffeic acid phenethyl ester (CAPE) derived from honeybee propolis has been used as a folk medicine. Recent study also revealed that CAPE has several biological activities including antioxidation, anti-inflammation and inhibition of tumor growth. The present study investigated the effect of CAPE on tumor invasion and metastasis by determining the regulation of matrix metalloproteinases (MMPs). Matrix metalloproteinases, which are zinc-dependent proteolytic enzymes, play a pivotal role in tumor metastasis by cleavage of extracellular matrix (ECM) as well as nonmatrix substrates. On this line, we examined the influence of CAPE on the gene expression of MMPs (MMP-2, MMP-9, MT1-MMP), tissue inhibitor of metalloproteinase-2 (TIMP-2) and in vitro invasiveness of human fibrosarcoma cells. Dose-dependent decreases in MMP and TIMP-2 mRNA levels were observed in CAPE-treated HT1080 human fibrosarcoma cells as detected by reverse transcriptase-polymerase chain reaction (RT-PCR). Gelatin zymography analysis also exhibited a significant down-regulation of MMP-2 and MMP-9 expression in HT1080 cells treated with CAPE compared to controls. In addition, CAPE inhibited the activated MMP-2 activity as well as invasion, motility, cell migration and colony formation of tumor cells. These data therefore provide direct evidence for the role of CAPE as a potent antimetastatic agent, which can markedly inhibit the metastatic and invasive capacity of malignant cells.
Chen, Ying-Jung; Lin, Ku-Nan; Jhang, Li-Mei; Huang, Chia-Hui; Lee, Yuan-Chin; Chang, Long-Sen
2016-05-25
Several studies have revealed that natural compounds are valuable resources to develop novel agents against dysregulation of the EGF/EGFR-mediated matrix metalloproteinase-9 (MMP-9) expression in cancer cells. In view of the findings that EGF/EGFR-mediated MMP-9 expression is closely related to invasion and metastasis of breast cancer. To determine the beneficial effects of gallic acid on the suppression of breast cancer metastasis, we explored the effect of gallic acid on MMP-9 expression in EGF-treated MCF-7 breast cancer cells. Treatment with EGF up-regulated MMP-9 mRNA and protein levels in MCF-7 cells. EGF treatment induced phosphorylation of EGFR and elicited Src activation, subsequently promoting Akt/NFκB (p65) and ERK/c-Jun phosphorylation in MCF-7 cells. Activation of Akt/p65 and ERK/c-Jun was responsible for the MMP-9 up-regulation in EGF-treated cells. Gallic acid repressed the EGF-induced activation of EGFR and Src; furthermore, inactivation of Akt/p65 and ERK/c-Jun was a result of the inhibitory effect of gallic acid on the EGF-induced MMP-9 up-regulation. Over-expression of constitutively active Akt and MEK1 or over-expression of constitutively active Src eradicated the inhibitory effect of gallic acid on the EGF-induced MMP-9 up-regulation. A chromosome conformation capture assay showed that EGF induced a chromosomal loop formation in the MMP-9 promoter via NFκB/p65 and AP-1/c-Jun activation. Treatment with gallic acid, EGFR inhibitor, or Src inhibitor reduced DNA looping. Taken together, our data suggest that gallic acid inhibits the activation of EGFR/Src-mediated Akt and ERK, leading to reduced levels of p65/c-Jun-mediated DNA looping and thus inhibiting MMP-9 expression in EGF-treated MCF-7 cells.
Energy Technology Data Exchange (ETDEWEB)
Lambert, D.; Stone, M.; Newell, J.; Best, D.
2012-05-07
Savannah River Remediation (SRR) is evaluating changes to its current DWPF flowsheet to improve processing cycle times. This will enable the facility to support higher canister production while maximizing waste loading. Higher throughput is needed in the CPC since the installation of the bubblers into the melter has increased melt rate. Due to the significant maintenance required for the DWPF gas chromatographs (GC) and the potential for production of flammable quantities of hydrogen, reducing or eliminating the amount of formic acid used in the CPC is being developed. Earlier work at Savannah River National Laboratory has shown that replacing formic acid with an 80:20 molar blend of glycolic and formic acids has the potential to remove mercury in the SRAT without any significant catalytic hydrogen generation. This report summarizes the research completed to determine the feasibility of processing without formic acid. In earlier development of the glycolic-formic acid flowsheet, one run (GF8) was completed without formic acid. It is of particular interest that mercury was successfully removed in GF8, no formic acid at 125% stoichiometry. Glycolic acid did not show the ability to reduce mercury to elemental mercury in initial screening studies, which is why previous testing focused on using the formic/glycolic blend. The objective of the testing detailed in this document is to determine the viability of the nitric-glycolic acid flowsheet in processing sludge over a wide compositional range as requested by DWPF. This work was performed under the guidance of Task Technical and Quality Assurance Plan (TT and QAP). The details regarding the simulant preparation and analysis have been documented previously.
Kun, David William
Unmanned aircraft systems (UASs) are gaining popularity in civil and commercial applications as their lightweight on-board computers become more powerful and affordable, their power storage devices improve, and the Federal Aviation Administration addresses the legal and safety concerns of integrating UASs in the national airspace. Consequently, many researchers are pursuing novel methods to control UASs in order to improve their capabilities, dependability, and safety assurance. The nonlinear control approach is a common choice as it offers several benefits for these highly nonlinear aerospace systems (e.g., the quadrotor). First, the controller design is physically intuitive and is derived from well known dynamic equations. Second, the final control law is valid in a larger region of operation, including far from the equilibrium states. And third, the procedure is largely methodical, requiring less expertise with gain tuning, which can be arduous for a novice engineer. Considering these facts, this thesis proposes a nonlinear controller design method that combines the advantages of adaptive robust control (ARC) with the powerful design tools of linear matrix inequalities (LMI). The ARC-LMI controller is designed with a discontinuous projection-based adaptation law, and guarantees a prescribed transient and steady state tracking performance for uncertain systems in the presence of matched disturbances. The norm of the tracking error is bounded by a known function that depends on the controller design parameters in a known form. Furthermore, the LMI-based part of the controller ensures the stability of the system while overcoming polytopic uncertainties, and minimizes the control effort. This can reduce the number of parameters that require adaptation, and helps to avoid control input saturation. These desirable characteristics make the ARC-LMI control algorithm well suited for the quadrotor UAS, which may have unknown parameters and may encounter external
Third generation capture system: precipitating amino acid solvent systems
Sanchez Fernandez, E.; Misiak, K.; Ham, L. van der; Goetheer, E.L.V.
2013-01-01
This work summarises the results of the design of novel separation processes for CO2 removal from flue gas based on precipitating amino acid solvents. The processes here described (DECAB, DECAB Plus and pH-swing) use a combination of enhanced CO2 absorption (based on the Le Chatelier’s principle) an
Sifaou, Houssem
2016-05-01
Massive MIMO systems are shown to be a promising technology for next generations of wireless communication networks. The realization of the attractive merits promised by massive MIMO systems requires advanced linear precoding and receiving techniques in order to mitigate the interference in downlink and uplink transmissions. This work considers the precoder and receiver design in massive MIMO systems. We first consider the design of the linear precoder and receiver that maximize the minimum signal-to-interference-plus-noise ratio (SINR) subject to a given power constraint. The analysis is carried out under the asymptotic regime in which the number of the BS antennas and that of the users grow large with a bounded ratio. This allows us to leverage tools from random matrix theory in order to approximate the parameters of the optimal linear precoder and receiver by their deterministic approximations. Such a result is of valuable practical interest, as it provides a handier way to implement the optimal precoder and receiver. To reduce further the complexity, we propose to apply the truncated polynomial expansion (TPE) concept on a per-user basis to approximate the inverse of large matrices that appear on the expressions of the optimal linear transceivers. Using tools from random matrix theory, we determine deterministic approximations of the SINR and the transmit power in the asymptotic regime. Then, the optimal per-user weight coe cients that solve the max-min SINR problem are derived. The simulation results show that the proposed precoder and receiver provide very close to optimal performance while reducing signi cantly the computational complexity. As a second part of this work, the TPE technique in a per-user basis is applied to the optimal linear precoding that minimizes the transmit power while satisfying a set of target SINR constraints. Due to the emerging research eld of green cellular networks, such a problem is receiving increasing interest nowadays. Closed
Directory of Open Access Journals (Sweden)
Chih-Peng Huang
2016-01-01
Full Text Available Stability analysis issues and controller synthesis for descriptor systems with parametric uncertainty in the derivative matrix are discussed in this paper. The proposed descriptor system can extend the system’s modeling extent of physical and engineering systems from the traditional state-space model. First, based on the extended D-stability definitions for the descriptor model, necessary and sufficient admissibility and D-admissibility conditions for the unforced nominal descriptor system are derived and formulated by compact forms with strict linear matrix inequality (LMI manner. In contrast, existing results need to involve nonstrict LMIs, which cannot be evaluated by current LMI solvers and need some extra treatments. Deducing from the obtained distinct results, the roust admissibility and D-admissibility of the descriptor system with uncertainties in both the derivative matrix and the system’s matrices thus can be coped. Furthermore, by involving a proportional and derivative state feedback (PDSF control law, we further address the controller design for the resulting closed-loop systems. Since all the proposed criteria are explicitly expressed in terms of the strict LMIs, we can use applicable LMI solvers for evaluating the feasible solutions. Finally, the efficiency and practicability of the proposed approach are demonstrated by two illustrative examples.
Energy Technology Data Exchange (ETDEWEB)
Sacks, I.J.; Ashmore, B.C.; Champney, J.M.; Alesso, H.P.
1983-06-01
This report provides preliminary results generated by a Digraph Matrix Analysis (DMA) for a Systems Interaction analysis performed on the Safety Injection System of the Tennessee Valley Authority Watts Bar Nuclear Power Plant. An overview of DMA is provided along with a brief description of the computer codes used in DMA.
Energy Technology Data Exchange (ETDEWEB)
Sacks, I.J.; Ashmore, B.C.; Champney, J.M.; Alesso, H.P.
1983-06-01
This report provides preliminary results generated by a Digraph Matrix Analysis (DMA) for a Systems Interaction analysis performed on the Safety Injection System of the Tennessee Valley Authority Watts Bar Nuclear Power Plant. An overview of DMA is provided along with a brief description of the computer codes used in DMA.
Toomey, Niamh; Monaghan, Aine; Fanning, Séamus; Bolton, Declan J
2009-10-01
The transferability of antimicrobial resistance from lactic acid bacteria (LAB) to potential pathogenic strains was studied using in vitro methods and mating in a food matrix. Five LAB donors containing either erythromycin or tetracycline resistance markers on transferable elements were conjugally mated with LAB (Enterococcus faecalis, Lactococcus lactis) and pathogenic strains (Listeria spp., Salmonella ssp., Staphylococcus aureus, and Escherichia coli). In vitro transfer experiments were carried out with the donors and recipients using both the filter and plate mating methods. The food matrix consisted of fermented whole milk (fermented with the LAB donors) with the pathogenic recipients added as contaminants during the production process. All transconjugants were confirmed by phenotypic and molecular methods. Erythromycin resistance transfer from LAB strains to Listeria spp. was observed using both in vitro mating methods at high transfer frequencies of up to 5.1 x 10(-4) transconjugants per recipient. Also, high frequency transfer (ranging from 2.7 x 10(-8) up to 1.1 x 10(-3) transconjugants per recipient) of both erythromycin and tetracycline-resistance was observed between LAB species using in vitro methods. No resistance transfer was observed to Salmonella spp., Staphylococcus aureus, and E. coli. The only conjugal transfer observed in the fermented milk matrix was for tetracycline resistance between two LAB strains (at a transfer frequency of 2.6 x 10(-7) transconjugants per recipients). This study demonstrates the transfer of antimicrobial resistance from LAB to Listeria spp. using in vitro methods and also the transfer of resistance between LAB species in a food matrix. It highlights the involvement of LAB as a potential source of resistance determinants that may be disseminated between LAB and pathogenic strains including Listeria spp. Furthermore, it indicates that food matrices such as fermented milks may provide a suitable environment to support gene
Bile acid nuclear receptor FXR and digestive system diseases
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Lili Ding
2015-03-01
Full Text Available Bile acids (BAs are not only digestive surfactants but also important cell signaling molecules, which stimulate several signaling pathways to regulate some important biological processes. The bile-acid-activated nuclear receptor, farnesoid X receptor (FXR, plays a pivotal role in regulating bile acid, lipid and glucose homeostasis as well as in regulating the inflammatory responses, barrier function and prevention of bacterial translocation in the intestinal tract. As expected, FXR is involved in the pathophysiology of a wide range of diseases of gastrointestinal tract, including inflammatory bowel disease, colorectal cancer and type 2 diabetes. In this review, we discuss current knowledge of the roles of FXR in physiology of the digestive system and the related diseases. Better understanding of the roles of FXR in digestive system will accelerate the development of FXR ligands/modulators for the treatment of digestive system diseases.
300 Area waste acid treatment system closure plan
Energy Technology Data Exchange (ETDEWEB)
LUKE, S.N.
1999-05-17
The Hanford Facility Dangerous Waste Permit Application is considered to be a single application organized into a General Information Portion (document number DOERL-91-28) and a Unit-Specific Portion. The scope of the Unit-Specific Portion includes closure plan documentation submitted for individual, treatment, storage, and/or disposal units undergoing closure, such as the 300 Area Waste Acid Treatment System. Documentation contained in the General Information Portion is broader in nature and could be used by multiple treatment, storage, and/or disposal units (e.g., the glossary provided in the General Information Portion). Whenever appropriate, 300 Area Waste Acid Treatment System documentation makes cross-reference to the General Information Portion, rather than duplicating text. This 300 Area Waste Acid Treatment System Closure Plan (Revision 2) includes a Hanford Facility Dangerous Waste Permit Application, Part A, Form 3. Information provided in this closure plan is current as of April 1999.
NMF-mGPU: non-negative matrix factorization on multi-GPU systems.
Mejía-Roa, Edgardo; Tabas-Madrid, Daniel; Setoain, Javier; García, Carlos; Tirado, Francisco; Pascual-Montano, Alberto
2015-02-13
In the last few years, the Non-negative Matrix Factorization ( NMF ) technique has gained a great interest among the Bioinformatics community, since it is able to extract interpretable parts from high-dimensional datasets. However, the computing time required to process large data matrices may become impractical, even for a parallel application running on a multiprocessors cluster. In this paper, we present NMF-mGPU, an efficient and easy-to-use implementation of the NMF algorithm that takes advantage of the high computing performance delivered by Graphics-Processing Units ( GPUs ). Driven by the ever-growing demands from the video-games industry, graphics cards usually provided in PCs and laptops have evolved from simple graphics-drawing platforms into high-performance programmable systems that can be used as coprocessors for linear-algebra operations. However, these devices may have a limited amount of on-board memory, which is not considered by other NMF implementations on GPU. NMF-mGPU is based on CUDA ( Compute Unified Device Architecture ), the NVIDIA's framework for GPU computing. On devices with low memory available, large input matrices are blockwise transferred from the system's main memory to the GPU's memory, and processed accordingly. In addition, NMF-mGPU has been explicitly optimized for the different CUDA architectures. Finally, platforms with multiple GPUs can be synchronized through MPI ( Message Passing Interface ). In a four-GPU system, this implementation is about 120 times faster than a single conventional processor, and more than four times faster than a single GPU device (i.e., a super-linear speedup). Applications of GPUs in Bioinformatics are getting more and more attention due to their outstanding performance when compared to traditional processors. In addition, their relatively low price represents a highly cost-effective alternative to conventional clusters. In life sciences, this results in an excellent opportunity to facilitate the
The Matrix Rib Plating System: improving aesthetic outcomes in microvascular breast reconstruction.
Ahdoot, Michael A; Echo, Anthony; Otake, Leo R; Son, Ji; Zeidler, Kamakshi R; Saadian, Isaac; Lee, Gordon K
2013-04-01
During microvascular breast reconstruction, exposure of internal mammary vessels (IMVs) is facilitated by the removal of a portion of the rib resulting in occasional chest contour deformity (CCD). The use of rib plating may reduce CCD and reduce postoperative pain. All patients underwent microvascular breast reconstruction using IMVs. In the retrospective arm, photographs were assessed by a blinded reviewer for CCDs. In the prospective cohort, patients were randomized to rib plating with the Synthes Matrix Rib Plating System or no rib plating. Postoperatively, patients were assessed for CCD and pain. In the retrospective arm, 11 of 98 (11.2%) patients representing 12 of 130 (9.2%) breast reconstructions had a noticeable contour deformity. The average body mass index (BMI) of patients with CCDs was 26.6 kg/m. In the prospective arm, there was 16% (3 of 19) rate of visible and palpable CCDs among controls, compared to 0% rate of palpable and visible contour deformity in the rib plating group. Pain was decreased in the rib plating group on all postoperative days. The pain reduction was statistically significant at rest by postoperative day 30. The majority of patients (9 of 11) with compromised aesthetic outcomes had a BMI less than 30 kg/m, suggesting a paucity of overlying soft tissue contributed to visibility of these bony defects. Rib plating prevented chest contour deformity, reduced postoperative pain, and added limited additional morbidity. We believe that rib plating is a safe, useful adjunct to microvascular breast reconstruction using IMVs, as it may improve aesthetic outcomes and reduce postoperative pain.
A fully automatic system for acid-base coulometric titrations
1990-01-01
An automatic system for acid-base titrations by electrogeneration of H+ and OH- ions, with potentiometric end-point detection, was developed. The system includes a PC-compatible computer for instrumental control, data acquisition and processing, which allows up to 13 samples to be analysed sequentially with no human intervention. The system performance was tested on the titration of standard solutions, which it carried out with low errors and RSD. It was subsequently applied to the analysis o...
Status of commercial phosphoric acid fuel cell system development
Warshay, M.; Prokopius, P. R.; Simons, S. N.; King, R. B.
1981-01-01
A review of the current commercial phosphoric acid fuel cell system development efforts is presented. In both the electric utility and on-site integrated energy system applications, reducing cost and increasing reliability are important. The barrier to the attainment of these goals has been materials. The differences in approach among the three major participants are their technological features, including electrodes, matrices, intercell cooling, bipolar/separator plates, electrolyte management, fuel selection and system design philosophy.
Vermeiren, Koen
2005-08-26
Since years, ion exclusion chromatography (ICE) has been the standard method to separate strong acid analyte anions from concentrated weak acid matrices such as hydrofluoric acid (HF). In this work, the commercially available IonPac ICE-AS 1 column was used to separate trace levels of chloride, nitrate, sulfate and phosphate from HF solutions at 20% (w/w). The efficiency of the separation was studied in more detail using techniques such as ion chromatography (IC), inductively coupled plasma optical emission spectrometry (ICP-OES) and ICP-mass spectrometry (ICP-MS). For 20% (w/w) HF solutions and at a water carrier flow-rate of 0.50 ml/min, the cut window was set from 8.5 to 14.5 min. Under these conditions, analyte recoveries of better than 90% were obtained for chloride, nitrate and sulfate, but only about 75% for phosphate. The HF rejection efficiency was better than 99.9%. It was found that the ICP techniques, measuring total element levels and not species, yielded significantly higher recoveries for phosphorus and sulfur compared to IC. Evidence will be given that part of the added phosphorus (approximately 15% for an addition of 10 mg PO4/kg) is present as mono-fluorophosphoric acid (H2FPO3). In the case of sulfate, the difference between IC and ICP-MS could be attributed to an important matrix effect from the residual HF concentration.
Directory of Open Access Journals (Sweden)
Mariana Ferreira Rocha
Full Text Available The objective of our work was to verify the value of the vegetation corridor in the conservation of small mammals in fragmented tropical landscapes, using a model system in the southeastern Minas Gerais. We evaluated and compared the composition and structure of small mammals in a vegetation corridor, forest fragments and a coffee matrix. A total of 15 species were recorded, and the highest species richness was observed in the vegetation corridor (13 species, followed by the forest fragments (10 and the coffee matrix (6. The absolute abundance was similar between the vegetation corridor and fragments (F = 22.94; p = 0.064, and the greatest differences occurred between the vegetation corridor and the matrix (F = 22.94; p = 0.001 and the forest fragments and the matrix (F = 22.94; p = 0.007. Six species showed significant habitat preference possibly related to the sensitivity of the species to the forest disturbance. Marmosops incanus was the species most sensitive to disturbance; Akodon montensis, Cerradomys subflavus, Gracilinanus microtarsus and Rhipidomys sp. displayed little sensitivity to disturbance, with a high relative abundance in the vegetation corridor. Calomys sp. was the species least affected by habitat disturbance, displaying a high relative abundance in the coffee matrix. Although the vegetation corridors are narrow (4 m width, our results support the hypothesis in which they work as a forest extension, share most species with the forest fragment and support species richness and abundance closer to forest fragments than to the coffee matrix. Our work highlights the importance and cost-effectiveness of these corridors to biodiversity management in the fragmented Atlantic Forest landscapes and at the regional level.
Directory of Open Access Journals (Sweden)
Javier Andrés Arias Sanabria
2010-10-01
Full Text Available Strategic information systems planning (SISP allows an organisation to determine a portfolio of computer-based applications to help it achieve its business objectives. IBM’s business system planning for strategic alignment (BSP/SA is an important technique for developing a strategic plan for an entire company’s information resource. BSP/SA has been described in terms of stages and the specific tasks within them. Tasks are usually done manually and require some experience. This work was thus aimed at presenting a computer-based application that automates two of the most important tasks in BSP/SA methodology: process-organisation matrix (POM and processes-data classes–matrix (PDM. Special emphasis was placed on analysing, designing and implementing systems development life-cycle for developing the software. An important part of the analysis consisted of conducting a literature review and the semi-structured interviews with some experts in SISP. A special contribution of the present work is the design and implementation of statistical reports associated with each matrix. Automating this task has facilitated students being able to analyse POM and PDM during SISP workshops forming part of the Information Systems Management course (Systems Engineering, Universidad Nacional de Colombia. Results arising from the workshops have also been improved.
Directory of Open Access Journals (Sweden)
Saied Mostafa Moazzami
2014-09-01
Full Text Available Direct restoration of severely damaged endodontically treated teeth (ETT using available and conventional and current matrix systems is sometimes impractical and in some clinical cases is impossible. The aim of this paper is to introduce and describe a new matrix system based on Rigid Tray Technique (RTT for dealing with such difficult clinical cases.
Homogeneous vs. heterogeneous nucleation in water-dicarboxylic acid systems
Directory of Open Access Journals (Sweden)
A. I. Hienola
2008-10-01
Full Text Available Binary heterogeneous nucleation of water-succinic/glutaric/malonic/adipic acid on nanometer-sized particles is investigated within the frame of classical heterogeneous nucleation theory. Homogeneous nucleation is also included for comparison. It is found that the nucleation probabilities depend on the contact angle and on the size of the seed particles. New thermodynamical properties, such as saturation vapor pressure, density and surface tension for all the dicarboxylic acid aqueous solutions are included in the calculations. While the new surface tension and density formulations do not bring any significant difference in the computed nucleation rate for homogeneous nucleation for succinic and glutaric acids, the use of the newly derived equations for the vapor pressure decrease the acid concentrations in gas phase with 3 orders of magnitude. According to our calculations, the binary heterogeneous nucleation of succinic acid-water and glutaric acid-water – although it requires a 3–4 orders of magnitude lower vapor concentrations than the homogeneous nucleation – cannot take place in atmospheric conditions. On the other hand binary homogeneous nucleation of adipic acid-water systems might be possible in conditions occuring in upper boundary layer. However, a more detailed characterization of the interaction between the surface and the molecules of the nucleating vapor should be considered in the future.
Zhang, Feng; Meng, Fan; Lubach, Joseph; Koleng, Joseph; Watson, N A
2016-08-01
The interactions between poly(ethylene oxide) (PEO) and poly(acrylic acid) (PAA) in aqueous medium at pH 6.8 were investigated in the current study. We have also studied the effect of interpolymer interactions and various formulation variables, including the molecular weight of PEO, the ratio between PEO and PAA, the crystallinity of PEO, and the presence of an acidifying agent, on the release of theophylline from matrix tablets containing both PEO and PAA as release retardants. At pH 6.8, the synergy in solution viscosity between PEO and PAA as the result of ion-dipole interaction was observed in this study. The release of theophylline from the matrix tablets containing physical mixtures of PEO and PAA was found to be a function of dissolution medium pH because of the pH-dependent interactions between these two polymers. Because of the formation of water insoluble interpolymer complex between PEO and PAA in aqueous medium at pH below 4.0, the release of theophylline was independent of PEO molecular weight and was controlled by Fickian diffusion mechanism in 0.01N hydrochloric acid solution. In comparison, the drug release was a function of PEO molecular weight and followed the anomalous transport mechanism in phosphate buffer pH 6.8. The presence of PAA exerted opposite effects on the release of theophylline in phosphate buffer pH 6.8. In one aspect, theophylline release was accelerated because the erosion of PAA was much faster than that of PEO at pH6.8. On the opposite aspect, theophylline release was slowed down because of the formation of insoluble complex inside the gel layer as the result of the acidic microenvironment induced by PAA, and the increase in the viscosity of the gel layer as the result of the synergy between PEO and PAA. These two opposite effects offset each other. As a result, the release of theophylline remained statistically the same even when 75% PEO in the formulation was replaced with PAA. In phosphate buffer pH 6.8, the release of
Exploitation of Bile Acid Transport Systems in Prodrug Design
Directory of Open Access Journals (Sweden)
Elina SievÃƒÂ¤nen
2007-08-01
Full Text Available The enterohepatic circulation of bile acids is one of the most efficient recycling routes in the human body. It is a complex process involving numerous transport proteins, which serve to transport bile acids from the small intestine into portal circulation, from the portal circulation into the hepatocyte, from the hepatocyte into the bile, and from the gall bladder to the small intestine. The tremendous transport capacity and organ specificity of enterohepatic circulation combined with versatile derivatization possibilities, rigid steroidal backbone, enantiomeric purity, availability, and low cost have made bile acids attractive tools in designing pharmacological hybrid molecules and prodrugs with the view of improving intestinal absorption, increasing the metabolic stability of pharmaceuticals, specifically targeting drugs to organs involved in enterohepatic circulation, as well as sustaining therapeutically reasonable systemic concentrations of active agents. This article briefly describes bile acid transport proteins involved in enterohepatic circulation, summarizes the key factors affecting on the transport by these proteins, and reviews the use of bile acids and their derivatives in designing prodrugs capable of exploiting the bile acid transport system.
Lead/acid batteries in systems to improve power quality
Taylor, P.; Butler, P.; Nerbun, W.
Increasing dependence on computer technology is driving needs for extremely high-quality power to prevent loss of information, material, and workers' time that represent billions of dollars annually. This cost has motivated commercial and Federal research and development of energy storage systems that detect and respond to power-quality failures in milliseconds. Electrochemical batteries are among the storage media under investigation for these systems. Battery energy storage systems that employ either flooded lead/acid or valve-regulated lead/acid battery technologies are becoming commercially available to capture a share of this emerging market. Cooperative research and development between the US Department of Energy and private industry have led to installations of lead/acid-based battery energy storage systems to improve power quality at utility and industrial sites and commercial development of fully integrated, modular battery energy storage system products for power quality. One such system by AC Battery Corporation, called the PQ2000, is installed at a test site at Pacific Gas and Electric Company (San Ramon, CA, USA) and at a customer site at Oglethorpe Power Corporation (Tucker, GA, USA). The PQ2000 employs off-the-shelf power electronics in an integrated methodology to control the factors that affect the performance and service life of production-model, low-maintenance, flooded lead/acid batteries. This system, and other members of this first generation of lead/acid-based energy storage systems, will need to compete vigorously for a share of an expanding, yet very aggressive, power quality market.
GFT projection NMR for efficient (1)H/ (13)C sugar spin system identification in nucleic acids.
Atreya, Hanudatta S; Sathyamoorthy, Bharathwaj; Jaipuria, Garima; Beaumont, Victor; Varani, Gabriele; Szyperski, Thomas
2012-12-01
A newly implemented G-matrix Fourier transform (GFT) (4,3)D HC(C)CH experiment is presented in conjunction with (4,3)D HCCH to efficiently identify (1)H/(13)C sugar spin systems in (13)C labeled nucleic acids. This experiment enables rapid collection of highly resolved relay 4D HC(C)CH spectral information, that is, shift correlations of (13)C-(1)H groups separated by two carbon bonds. For RNA, (4,3)D HC(C)CH takes advantage of the comparably favorable 1'- and 3'-CH signal dispersion for complete spin system identification including 5'-CH. The (4,3)D HC(C)CH/HCCH based strategy is exemplified for the 30-nucleotide 3'-untranslated region of the pre-mRNA of human U1A protein.
Motuku, Molefi
The low velocity impact response and damage evolution in unreinforced polymer matrices, conventional polymer matrix composites, and self-repairing polymer matrix composites was investigated. The impact response study of unreinforced matrices and conventional laminates was undertaken because the failure initiation energies, threshold energy levels, failure characteristics and damage evolution in both the matrix material (unreinforced resin plaques) and the composite are intrinsic to proper design of a self-repairing composite. The self-repairing concept was investigated due to its attractive potential to alleviate damage problems in polymer matrix composites. Self-repairing composites, which fall under the category of passive smart polymer composites, have the potential to self repair both micro- and macro-damage resulting from impacts as well as non-impact loading. The self-repairing mechanism is achieved through the incorporation of hollow fibers in addition to the normal solid reinforcing fibers. The hollow fibers store the damage-repairing solution or chemicals that are released into the matrix or damaged zone upon fiber failure to repair and/or arrest damage progression. The room temperature low velocity impact response and damage evolution in DERAKANE 411-350 and 411-C50 vinyl ester unreinforced resin systems was investigated as a function of impact energy level, sample thickness, matrix material and catalyst system. The low velocity impact response of conventional and self-repairing glass reinforced polymer composites was investigated by addressing the fabrication and some of the parameters that influence their response to low velocity impact loading. Specific issues addressed by this study include developing a process to fabricate self-repairing laminates, processing quality; selection of storage material for the repairing solution; release and transportation of repairing solution; the effect of the number, type and spatial distribution of the repairing
Yankovskaya, A.; Cherepanov, D.; Selivanikova, O.
2016-08-01
An extended matrix model of data and knowledge representation on the investigated area, as well as a matrix model of data representation on the territory under investigation, are proposed for the intelligent system of road-climatic zoning of territories (RCZT) - the main information technology of RCZT. A part of the West Siberian region has been selected as the investigated territory. The extended matrix model of knowledge representation is filled out by knowledge engineers with participation of highly qualified experts in the field of RCZT. The matrix model of data representation on the territory under investigation is filled out by persons concerned in RCZT of the motor-roads management system.
Difference between Chitosan Hydrogels via Alkaline and Acidic Solvent Systems
Nie, Jingyi; Wang, Zhengke; Hu, Qiaoling
2016-10-01
Chitosan (CS) has generated considerable interest for its desirable properties and wide applications. Hydrogel has been proven to be a major and vital form in the applications of CS materials. Among various types of CS hydrogels, physical cross-linked CS hydrogels are popular, because they avoided the potential toxicity and sacrifice of intrinsic properties caused by cross-linking or reinforcements. Alkaline solvent system and acidic solvent system are two important solvent systems for the preparation of physical cross-linked CS hydrogels, and also lay the foundations of CS hydrogel-based materials in many aspects. As members of physical cross-linked CS hydrogels, gel material via alkaline solvent system showed significant differences from that via acidic solvent system, but the reasons behind are still unexplored. In the present work, we studied the difference between CS hydrogel via alkaline system and acidic system, in terms of gelation process, hydrogel structure and mechanical property. In-situ/pseudo in-situ studies were carried out, including fluorescent imaging of gelation process, which provided dynamic visualization. Finally, the reasons behind the differences were explained, accompanied by the discussion about design strategy based on gelation behavior of the two systems.
Directory of Open Access Journals (Sweden)
Hasreet K Gill
2016-08-01
Full Text Available Most epithelial cells secrete a glycoprotein-rich apical extracellular matrix that can have diverse but still poorly understood roles in development and physiology. Zona Pellucida (ZP domain glycoproteins are common constituents of these matrices, and their loss in humans is associated with a number of diseases. Understanding of the functions, organization and regulation of apical matrices has been hampered by difficulties in imaging them both in vivo and ex vivo. We identified the PAN-Apple, mucin and ZP domain glycoprotein LET-653 as an early and transient apical matrix component that shapes developing epithelia in C. elegans. LET-653 has modest effects on shaping of the vulva and epidermis, but is essential to prevent lumen fragmentation in the very narrow, unicellular excretory duct tube. We were able to image the transient LET-653 matrix by both live confocal imaging and transmission electron microscopy. Structure/function and fluorescence recovery after photobleaching studies revealed that LET-653 exists in two separate luminal matrix pools, a loose fibrillar matrix in the central core of the lumen, to which it binds dynamically via its PAN domains, and an apical-membrane-associated matrix, to which it binds stably via its ZP domain. The PAN domains are both necessary and sufficient to confer a cyclic pattern of duct lumen localization that precedes each molt, while the ZP domain is required for lumen integrity. Ectopic expression of full-length LET-653, but not the PAN domains alone, could expand lumen diameter in the developing gut tube, where LET-653 is not normally expressed. Together, these data support a model in which the PAN domains regulate the ability of the LET-653 ZP domain to interact with other factors at the apical membrane, and this ZP domain interaction promotes expansion and maintenance of lumen diameter. These data identify a transient apical matrix component present prior to cuticle secretion in C. elegans, demonstrate
Gill, Hasreet K; Cohen, Jennifer D; Ayala-Figueroa, Jesus; Forman-Rubinsky, Rachel; Poggioli, Corey; Bickard, Kevin; Parry, Jean M; Pu, Pu; Hall, David H; Sundaram, Meera V
2016-08-01
Most epithelial cells secrete a glycoprotein-rich apical extracellular matrix that can have diverse but still poorly understood roles in development and physiology. Zona Pellucida (ZP) domain glycoproteins are common constituents of these matrices, and their loss in humans is associated with a number of diseases. Understanding of the functions, organization and regulation of apical matrices has been hampered by difficulties in imaging them both in vivo and ex vivo. We identified the PAN-Apple, mucin and ZP domain glycoprotein LET-653 as an early and transient apical matrix component that shapes developing epithelia in C. elegans. LET-653 has modest effects on shaping of the vulva and epidermis, but is essential to prevent lumen fragmentation in the very narrow, unicellular excretory duct tube. We were able to image the transient LET-653 matrix by both live confocal imaging and transmission electron microscopy. Structure/function and fluorescence recovery after photobleaching studies revealed that LET-653 exists in two separate luminal matrix pools, a loose fibrillar matrix in the central core of the lumen, to which it binds dynamically via its PAN domains, and an apical-membrane-associated matrix, to which it binds stably via its ZP domain. The PAN domains are both necessary and sufficient to confer a cyclic pattern of duct lumen localization that precedes each molt, while the ZP domain is required for lumen integrity. Ectopic expression of full-length LET-653, but not the PAN domains alone, could expand lumen diameter in the developing gut tube, where LET-653 is not normally expressed. Together, these data support a model in which the PAN domains regulate the ability of the LET-653 ZP domain to interact with other factors at the apical membrane, and this ZP domain interaction promotes expansion and maintenance of lumen diameter. These data identify a transient apical matrix component present prior to cuticle secretion in C. elegans, demonstrate critical roles for
Random matrix models for decoherence and fidelity decay in quantum information systems
Pineda, Carlos; Seligman, Thomas H.
2008-03-01
This course aims to introduce the student to random matrix models for decoherence and fidelity decay. They present a very powerful alternate approach, that emphasizes the disordered character of many environments and uncontrollable perturbations/couplings. The inherent integrability of such models makes analytic studies possible. We limit our considerations to linear response treatment, as high fidelity and small decoherence are the backbone of quantum information processes. For fidelity decay, where experimental results are available, a comparison with experiments shows excellent agreement with random matrix theory predictions.
Seraji, H.
1987-01-01
Given a multivariable system, it is proved that the numerator matrix N(s) of the transfer function evaluated at any system pole either has unity rank or is a null matrix. It is also shown that N(s) evaluated at any transmission zero of the system has rank deficiency. Examples are given for illustration.
Thermodynamic properties of citric acid and the system citric acid-water
Kruif, C.G. de; Miltenburg, J.C. van; Sprenkels, A.J.J.; Stevens, G.; Graaf, W. de; Wit, H.G.M. de
1982-01-01
The binary system citric acid-water has been investigated with static vapour pressure measurements, adiabatic calorimetry, solution calorimetry, solubility measurements and powder X-ray measurements. The data are correlated by thermodynamics and a large part of the phase diagram is given. Molar heat
Thermodynamic properties of citric acid and the system citric acid-water
Kruif, C.G. de; Miltenburg, J.C. van; Sprenkels, A.J.J.; Stevens, G.; Graaf, W. de; Wit, H.G.M. de
1982-01-01
The binary system citric acid-water has been investigated with static vapour pressure measurements, adiabatic calorimetry, solution calorimetry, solubility measurements and powder X-ray measurements. The data are correlated by thermodynamics and a large part of the phase diagram is given. Molar heat
Analytical, experimental, and Monte Carlo system response matrix for pinhole SPECT reconstruction
Energy Technology Data Exchange (ETDEWEB)
Aguiar, Pablo, E-mail: pablo.aguiar.fernandez@sergas.es [Fundación Ramón Domínguez, Medicina Nuclear, CHUS, Spain and Grupo de Imaxe Molecular, IDIS, Santiago de Compostela 15706 (Spain); Pino, Francisco [Unitat de Biofísica, Facultat de Medicina, Universitat de Barcelona, Spain and Servei de Física Médica i Protecció Radiológica, Institut Catalá d' Oncologia, Barcelona 08036 (Spain); Silva-Rodríguez, Jesús [Fundación Ramón Domínguez, Medicina Nuclear, CHUS, Santiago de Compostela 15706 (Spain); Pavía, Javier [Servei de Medicina Nuclear, Hospital Clínic, Barcelona (Spain); Institut d' Investigacions Biomèdiques August Pí i Sunyer (IDIBAPS) (Spain); CIBER en Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Barcelona 08036 (Spain); Ros, Doménec [Unitat de Biofísica, Facultat de Medicina, Casanova 143 (Spain); Institut d' Investigacions Biomèdiques August Pí i Sunyer (IDIBAPS) (Spain); CIBER en Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Barcelona 08036 (Spain); Ruibal, Álvaro [Servicio Medicina Nuclear, CHUS (Spain); Grupo de Imaxe Molecular, Facultade de Medicina (USC), IDIS, Santiago de Compostela 15706 (Spain); Fundación Tejerina, Madrid (Spain); and others
2014-03-15
Purpose: To assess the performance of two approaches to the system response matrix (SRM) calculation in pinhole single photon emission computed tomography (SPECT) reconstruction. Methods: Evaluation was performed using experimental data from a low magnification pinhole SPECT system that consisted of a rotating flat detector with a monolithic scintillator crystal. The SRM was computed following two approaches, which were based on Monte Carlo simulations (MC-SRM) and analytical techniques in combination with an experimental characterization (AE-SRM). The spatial response of the system, obtained by using the two approaches, was compared with experimental data. The effect of the MC-SRM and AE-SRM approaches on the reconstructed image was assessed in terms of image contrast, signal-to-noise ratio, image quality, and spatial resolution. To this end, acquisitions were carried out using a hot cylinder phantom (consisting of five fillable rods with diameters of 5, 4, 3, 2, and 1 mm and a uniform cylindrical chamber) and a custom-made Derenzo phantom, with center-to-center distances between adjacent rods of 1.5, 2.0, and 3.0 mm. Results: Good agreement was found for the spatial response of the system between measured data and results derived from MC-SRM and AE-SRM. Only minor differences for point sources at distances smaller than the radius of rotation and large incidence angles were found. Assessment of the effect on the reconstructed image showed a similar contrast for both approaches, with values higher than 0.9 for rod diameters greater than 1 mm and higher than 0.8 for rod diameter of 1 mm. The comparison in terms of image quality showed that all rods in the different sections of a custom-made Derenzo phantom could be distinguished. The spatial resolution (FWHM) was 0.7 mm at iteration 100 using both approaches. The SNR was lower for reconstructed images using MC-SRM than for those reconstructed using AE-SRM, indicating that AE-SRM deals better with the
High Level Waste System Impacts from Acid Dissolution of Sludge
Energy Technology Data Exchange (ETDEWEB)
KETUSKY, EDWARD
2006-04-20
This research evaluates the ability of OLI{copyright} equilibrium based software to forecast Savannah River Site High Level Waste system impacts from oxalic acid dissolution of Tank 1-15 sludge heels. Without further laboratory and field testing, only the use of oxalic acid can be considered plausible to support sludge heel dissolution on multiple tanks. Using OLI{copyright} and available test results, a dissolution model is constructed and validated. Material and energy balances, coupled with the model, identify potential safety concerns. Overpressurization and overheating are shown to be unlikely. Corrosion induced hydrogen could, however, overwhelm the tank ventilation. While pH adjustment can restore the minimal hydrogen generation, resultant precipitates will notably increase the sludge volume. OLI{copyright} is used to develop a flowsheet such that additional sludge vitrification canisters and other negative system impacts are minimized. Sensitivity analyses are used to assess the processability impacts from variations in the sludge/quantities of acids.
Richter, S S; Sercia, L; Branda, J A; Burnham, C-A D; Bythrow, M; Ferraro, M J; Garner, O B; Ginocchio, C C; Jennemann, R; Lewinski, M A; Manji, R; Mochon, A B; Rychert, J A; Westblade, L F; Procop, G W
2013-12-01
This multicenter study evaluated the accuracy of matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry identifications from the VITEK MS system (bioMérieux, Marcy l'Etoile, France) for Enterobacteriaceae typically encountered in the clinical laboratory. Enterobacteriaceae isolates (n = 965) representing 17 genera and 40 species were analyzed on the VITEK MS system (database v2.0), in accordance with the manufacturer's instructions. Colony growth (≤72 h) was applied directly to the target slide. Matrix solution (α-cyano-4-hydroxycinnamic acid) was added and allowed to dry before mass spectrometry analysis. On the basis of the confidence level, the VITEK MS system provided a species, genus only, or no identification for each isolate. The accuracy of the mass spectrometric identification was compared to 16S rRNA gene sequencing performed at MIDI Labs (Newark, DE). Supplemental phenotypic testing was performed at bioMérieux when necessary. The VITEK MS result agreed with the reference method identification for 96.7% of the 965 isolates tested, with 83.8% correct to the species level and 12.8% limited to a genus-level identification. There was no identification for 1.7% of the isolates. The VITEK MS system misidentified 7 isolates (0.7 %) as different genera. Three Pantoea agglomerans isolates were misidentified as Enterobacter spp. and single isolates of Enterobacter cancerogenus, Escherichia hermannii, Hafnia alvei, and Raoultella ornithinolytica were misidentified as Klebsiella oxytoca, Citrobacter koseri, Obesumbacterium proteus, and Enterobacter aerogenes, respectively. Eight isolates (0.8 %) were misidentified as a different species in the correct genus. The VITEK MS system provides reliable mass spectrometric identifications for Enterobacteriaceae.
Clements, R L
1988-02-01
A polyacrylamide gel electrophoresis system buffered by acetic acid alone was developed for electrophoresis of prolamines. When applied to gliadin electrophoresis, the acetic acid system produces more bands than does a conventional aluminum lactate-lactic acid system (using 12% acrylamide gels). The acetic acid system is relatively simple, requiring a single buffer component that is universally available in high purity.
21 CFR 862.3580 - Lysergic acid diethylamide (LSD) test system.
2010-04-01
... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Lysergic acid diethylamide (LSD) test system. 862... Test Systems § 862.3580 Lysergic acid diethylamide (LSD) test system. (a) Identification. A lysergic acid diethylamide (LSD) test system is a device intended to measure lysergic acid diethylamide, a...
21 CFR 862.1390 - 5-Hydroxyindole acetic acid/serotonin test system.
2010-04-01
... 21 Food and Drugs 8 2010-04-01 2010-04-01 false 5-Hydroxyindole acetic acid/serotonin test system... Test Systems § 862.1390 5-Hydroxyindole acetic acid/serotonin test system. (a) Identification. A 5-hydroxyindole acetic acid/serotonin test system is a device intended to measure 5-hydroxyindole acetic acid...
Institute of Scientific and Technical Information of China (English)
Min WU; Yong HE; Jinhua SHE
2004-01-01
Necessary and suffcient conditions for the existence of a Lyapunov function in the Lur'e form to guarantee the absolute stability ofLur' e control systems with multiple non-linearities are discussed in this paper. It simplifies the existence problem to one of solving a set of linear matrix inequalities (LMIs). If those LMIs are feasible, free parameters in the Lyapunov function,such as the positive definite matrix and the coefficients of the integral terms, are given by the solution of the LMIs. Otherwise, this Lyapunov function does not exist. Some sufficient conditions are also obtained for the robust absolute stability of uncertain systems.A numerical example is provided to demonstrate the effectiveness of the proposed method.
Chandel, Shubham; Ray, Subir K; Das, Anwesh; Ghosh, Anirudha; Raj, Satyabrata; Ghosh, Nirmalya
2015-01-01
Information on the polarization properties of scattered light from plasmonic systems are of paramount importance due to fundamental interest and potential applications. However, such studies are severely compromised due to the experimental difficulties in recording full polarization response of plasmonic nanostructures. Here, we report on a novel Mueller matrix spectroscopic system capable of acquiring complete polarization information from single isolated plasmonic nanoparticle/nanostructure. The outstanding issues pertaining to reliable measurements of full 4X4 spectroscopic scattering Mueller matrices from single nanoparticle/nanostructures are overcome by integrating an efficient Mueller matrix measurement scheme and a robust calibration method with a dark-field microscopic spectroscopy arrangement.The spectral polarization responses of the required polarization state generator, analyzer units, the imaging and the detection systemsare taken care off by eigenvalue calibration, thus enabling recording of th...
21 CFR 862.1305 - Formiminoglutamic acid (FIGLU) test system.
2010-04-01
... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Formiminoglutamic acid (FIGLU) test system. 862.1305 Section 862.1305 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry...
Konno, T
1998-04-01
The singular value decomposition (SVD) analysis was applied to a large set of far-ultraviolet circular dichroism (far-UV CD) spectra (100-400 spectra) of horse heart cytochrome c (cyt c). The spectra were collected at pH 1.7-5.0 in (NH4)2SO4, sorbitol and 2,2,2-trifluoroethanol (TFE) solutions. The present purpose is to develop a rigorous matrix method applied to far-UV CD spectra to resolve in details conformational properties of proteins in the non-native (or denatured) regions. The analysis established that three basis spectral components are contained in a data set of difference spectra (referred to the spectrum of the native state) used here. By a further matrix transformation, any observed spectrum could be decomposed into fractions of the native (N), the molten-globule (MG), the highly denatured (D), and the alcohol-induced helical (H) spectral forms. This method could determine fractional transition curves of each conformer as a function of solution conditions, which gave the results consistent with denaturation curves of cyt c monitored by other spectroscopic methods. The results in sorbitol solutions, for example, suggested that the preferential hydration effect of the co-solvent stabilizes the MG conformer of cyt c. This report has found that the systematic SVD analysis of the far-UV CD spectra is a powerful tool for the conformational analysis of the non-native species of a protein when it is suitably supplemented with other experimental methods.
Developing nucleic acid-based electrical detection systems
Gabig-Ciminska Magdalena
2006-01-01
Abstract Development of nucleic acid-based detection systems is the main focus of many research groups and high technology companies. The enormous work done in this field is particularly due to the broad versatility and variety of these sensing devices. From optical to electrical systems, from label-dependent to label-free approaches, from single to multi-analyte and array formats, this wide range of possibilities makes the research field very diversified and competitive. New challenges and r...
Developing nucleic acid-based electrical detection systems
Gabig-Ciminska Magdalena
2006-01-01
Abstract Development of nucleic acid-based detection systems is the main focus of many research groups and high technology companies. The enormous work done in this field is particularly due to the broad versatility and variety of these sensing devices. From optical to electrical systems, from label-dependent to label-free approaches, from single to multi-analyte and array formats, this wide range of possibilities makes the research field very diversified and competitive. New challenges and r...
Acidic phospholipid bicelles: a versatile model membrane system.
Struppe, J; Whiles, J A; Vold, R R
2000-01-01
With the aim of establishing acidic bicellar solutions as a useful membrane model system, we have used deuterium NMR spectroscopy to investigate the properties of dimyristoyl/dihexanoylphosphatidylcholine (DMPC/DHPC) bicelles containing 25% (w/w in H(2)O) of either dimyristoylphosphatidylserine (DMPS) or dimyristoylphosphatidylglycerol (DMPG). The addition of the acidic lipid component to this lyotropic liquid crystalline system reduces its range of stability because of poor miscibility of the two dimyristoylated phospholipids. Compared to the neutral bicelles, which are stable at pH 4 to pH 7, acidic bicelles are stable only from pH 5.5 to pH 7. Solid-state deuterium NMR analysis of d(54)-DMPC showed similar ordering in neutral and acidic bicelles. Fully deuterated DMPS or DMPG is ordered in a way similar to that of DMPC. Study of the binding of the myristoylated N-terminal 14-residue peptide mu-GSSKSKPKDPSQRR from pp60(nu-src) to both neutral and acidic bicelles shows the utility of these novel membrane mimetics. PMID:10620292
改性乳酸菌微胶囊壁材的研究进展%Research Progress on Modified Matrix of Lactic Acid Bacteria Microcapsule
Institute of Scientific and Technical Information of China (English)
刘媛; 孙也; 李淑雅; 王晶; 王艳萍
2016-01-01
乳酸菌微胶囊所用壁材主要为生物相容性良好的天然高分子材料.然而天然材料的结构种类有限,不能持续地提高微胶囊对乳酸菌活菌数量的保护作用.改性壁材可以根据用途对原有材料进行结构改造,在保持良好生物相容性的前提下,赋予壁材更好的保护功能.该文综述了国内外改性微胶囊壁材在乳酸菌微胶囊化方面的研究进展.%Biocompatible natural polymer materials are mainly uesd as the matrix of lactic acid bacteria micro-capsule. However, the protective effect on the viability of lactic acid bateria could not be consistently improved becasue of the limited structure of natural materials. Modified polymers with good biocompatibility and better protective effect could be obtained by modifying the original materials according to the application purpose. This paper reviewed the research progress of some modified polymer materials for lactic acid bacteria microencapsu-lation.
Cid, A; Morales, J; Mejuto, J C; Briz-Cid, N; Rial-Otero, R; Simal-Gándara, J
2014-05-15
Micellar systems have excellent food applications due to their capability to solubilise a large range of hydrophilic and hydrophobic substances. In this work, the mixed micelle formation between the ionic surfactant sodium dodecyl sulphate (SDS) and the phenolic acid salicylic acid have been studied at several temperatures in aqueous solution. The critical micelle concentration and the micellization degree were determined by conductometric techniques and the experimental data used to calculate several useful thermodynamic parameters, like standard free energy, enthalpy and entropy of micelle formation. Salicylic acid helps the micellization of SDS, both by increasing the additive concentration at a constant temperature and by increasing temperature at a constant concentration of additive. The formation of micelles of SDS in the presence of salicylic acid was a thermodynamically spontaneous process, and is also entropically controlled. Salicylic acid plays the role of a stabilizer, and gives a pathway to control the three-dimensional water matrix structure. The driving force of the micellization process is provided by the hydrophobic interactions. The isostructural temperature was found to be 307.5 K for the mixed micellar system. This article explores the use of SDS-salicylic acid based micellar systems for their potential use in fruits postharvest.
Initial guidance on digraph-matrix analysis for systems interaction studies at selected LWR's
Energy Technology Data Exchange (ETDEWEB)
Alesso, H.P.; Sacks, I.J.; Smith, C.F.
1982-08-12
The Nuclear Regulatory Commission (NRC) is currently developing guidance to search for and evaluate systems interactions at light water reactors (LWRs). In addition, related efforts are being made to incorporate such analyses into the framework of Probabilistic Risk Assessment (PRA). Preliminary results indicate that there are at least three concepts on how systems interactions can be analyzed independently or incorporated into an overall PRA. One point of view is that systems interactions can be adequately analyzed by enhancing existing PRAs. A second and closely related point of view is that systems interactions can be incorporated into a PRA in the event-tree stage of analysis. This approach attempts to capture systems interactions at an earlier stage of analysis. By treating dependencies in the event tree analysis portion of a PRA, the requirement of fault tree modeling at additional levels of detail is reduced. A third point of view about the Systems Interaction problem is that a new technique, called Digraph-Matrix Analysis (DMA), which utilizes matrix representation of logic diagrams, may offer a more complete and possibly more efficient analysis in certain areas. This report will present proposed initial guidance on DMA for application to systems interactions. DMA will be presented as a procedure independent from PRA. Peer review and later sample applications can provide useful feedback for refining the final guidance.
Energy Technology Data Exchange (ETDEWEB)
Matei, Andreea [INFLPR - National Institute for Laser, Plasma and Radiation Physics, 409 Atomistilor Str., Magurele RO-077125, Bucharest (Romania); Marinescu, Maria, E-mail: maria.marinescu@chimie.unibuc.ro [UB - University of Bucharest, Faculty of Chemistry, 90-92 Şoseaua Panduri, Sector 5, RO-010184, Bucharest (Romania); Constantinescu, Catalin, E-mail: catalin.constantinescu@inflpr.ro [INFLPR - National Institute for Laser, Plasma and Radiation Physics, 409 Atomistilor Str., Magurele RO-077125, Bucharest (Romania); Ion, Valentin; Mitu, Bogdana [INFLPR - National Institute for Laser, Plasma and Radiation Physics, 409 Atomistilor Str., Magurele RO-077125, Bucharest (Romania); Ionita, Iulian [INFLPR - National Institute for Laser, Plasma and Radiation Physics, 409 Atomistilor Str., Magurele RO-077125, Bucharest (Romania); UB - University of Bucharest, Faculty of Physics, 405 Atomistilor Str., Magurele RO-077125, Bucharest (Romania); Dinescu, Maria [INFLPR - National Institute for Laser, Plasma and Radiation Physics, 409 Atomistilor Str., Magurele RO-077125, Bucharest (Romania); Emandi, Ana [INFLPR - National Institute for Laser, Plasma and Radiation Physics, 409 Atomistilor Str., Magurele RO-077125, Bucharest (Romania); UB - University of Bucharest, Faculty of Chemistry, 90-92 Şoseaua Panduri, Sector 5, RO-010184, Bucharest (Romania)
2016-06-30
Graphical abstract: - Highlights: • A newly synthesized ferrocene-derivative exhibits SHG potential. • Matrix-assisted pulsed laser evaporation is employed for thin film fabrication. • The optical properties of the films are investigated, presented and discussed. • At maximum laser output power, the SHG signal is strongly influenced by thin film thickness. - Abstract: We present results on a new, laboratory synthesized ferrocene-derivative, i.e. 4-(ferrocenylmethylimino)-2-hydroxy-benzoic acid. Thin films with controlled thickness are deposited by matrix-assisted pulsed laser evaporation (MAPLE), on quartz and silicon substrates, with the aim of evaluating the nonlinear optical properties for potential optoelectronic applications. Dimethyl sulfoxide was used as matrix, with 1% wt. concentration of the guest compound. The frozen target is irradiated by using a Nd:YAG laser (4ω/266 nm, 7 ns pulse duration, 10 Hz repetition rate), at low fluences ranging from 0.1 to 1 J/cm{sup 2}. Atomic force microscopy (AFM) and scanning electron microscopy (SEM) are used to probe the surface morphology of the films. Fourier transform infrared (FTIR) and Raman spectroscopy reveal similar structure of the thin film material when compared to the starting material. The optical properties of the thin films are investigated by spectroscopic-ellipsometry (SE), and the refractive index dependence with respect to temperature is studied. The second harmonic generation (SHG) potential is assessed by using a femtosecond Ti:sapphire laser (800 nm, 60–100 fs pulse duration, 80 MHz repetition rate), at 200 mW maximum output power, revealing that the SHG signal intensity is strongly influenced by the films’ thickness.
Wang, Shu; Liu, Baomin; Yuan, Dongxing; Ma, Jian
2016-12-01
Glyphosate (GLYP) is an important herbicide which is also used as the phosphorus source for marine organisms. The wide applications of GLYP can lead to its accumulation in oceans and coastal waters, thus creating environmental issues. However, there is limited methods for detection of GLYP and its degradation product, aminomethylphosphonic acid (AMPA) in saline samples. Therefore, a simple and fast method for the quantification of GLYP and AMPA in seawater matrix has been developed based on the derivatization with 9-fluorenylmethylchloroformate (FMOC-Cl), separation with high performance liquid chromatography (HPLC) and detection with fluorescence detector (FLD). In order to maximize sensitivity, the derivatization procedure was carefully optimized regarding concentration of FMOC-Cl, volume of borate buffer, pH of borate buffer, mixing and derivatization time. The derivatization reaction could be completed within 30min in seawater samples without any additional clean-up or desalting steps. Under the optimized conditions, the developed HPLC method showed a wide linear response (up to several mg/L, R(2)>0.99). The limits of detection were 0.60μg/L and 0.30μg/L for GLYP and AMPA in seawater matrix, respectively. The relative standard deviation was 14.0% for GLYP (1.00mg/L) and 3.1% for AMPA (100μg/L) in saline samples with three different operators (n=24). This method was applied to determine the concentration of GLYP and AMPA in seawater culture media and the recovery data indicated minimal matrix interference. Due to its simplicity, high reproducibility and successful application in seawater culture media analysis, this method is a potentially useful analytical technique for both marine research and environmental science.
Tam, E; Pate, J L
1985-10-01
Prosthecae purified from cells of Asticcaulis biprosthecum possess active transport systems that transport all 20 amino acids tested. Using ascorbate-reduced phenazine methosulphate in the presence of oxygen, all 20 amino acids are accumulated against a concentration gradient by isolated prosthecae. Results of experiments testing the inhibition of transport of one amino acid by another, and of experiments testing the exchange of exogenous amino acids with those preloaded in prosthecae, along with characteristics of mutants defective in amino acid transport, suggest the presence in prosthecae of three amino acid transport systems. One, the general or G system, transports at least 18 of the 20 amino acids tested. Another system, referred to as the proline or P system, transports seven amino acids (including proline) that are also transported by the G system. The third system transports only glutamate and aspartate, and is referred to as the acidic amino acid transport system or A system.
Parallelism in matrix computations
Gallopoulos, Efstratios; Sameh, Ahmed H
2016-01-01
This book is primarily intended as a research monograph that could also be used in graduate courses for the design of parallel algorithms in matrix computations. It assumes general but not extensive knowledge of numerical linear algebra, parallel architectures, and parallel programming paradigms. The book consists of four parts: (I) Basics; (II) Dense and Special Matrix Computations; (III) Sparse Matrix Computations; and (IV) Matrix functions and characteristics. Part I deals with parallel programming paradigms and fundamental kernels, including reordering schemes for sparse matrices. Part II is devoted to dense matrix computations such as parallel algorithms for solving linear systems, linear least squares, the symmetric algebraic eigenvalue problem, and the singular-value decomposition. It also deals with the development of parallel algorithms for special linear systems such as banded ,Vandermonde ,Toeplitz ,and block Toeplitz systems. Part III addresses sparse matrix computations: (a) the development of pa...
[Modern polymers in matrix tablets technology].
Zimmer, Łukasz; Kasperek, Regina; Poleszak, Ewa
2014-01-01
Matrix tablets are the most popular method of oral drug administration, and polymeric materials have been used broadly in matrix formulations to modify and modulate drug release rate. The main goal of the system is to extend drug release profiles to maintain a constant in vivo plasma drug concentration and a consistent pharmacological effect. Polymeric matrix tablets offer a great potential as oral controlled drug delivery systems. Cellulose derivatives, like hydroxypropyl methylcellulose (HPMC) are often used as matrix formers. However, also other types of polymers can be used for this purpose including: Kollidon SR, acrylic acid polymers such as Eudragits and Carbopols. Nevertheless, polymers of natural origin like: carragens, chitosan and alginates widely used in the food and cosmetics industry are now coming to the fore of pharmaceutical research and are used in matrix tablets technology. Modern polymers allow to obtain matrix tablets by 3D printing, which enables to develop new formulation types. In this paper, the polymers used in matrix tablets technology and examples of their applications were described.
Directory of Open Access Journals (Sweden)
Eliana Esposito
2016-05-01
Full Text Available In composite materials made of polymer matrices and micro-nano dispersed compartments, the morphology of the dispersed phase can strongly affect several features of the final material, including stability, loading efficiency, and kinetic release of the embedded molecules. Such a polymer matrix composite can be obtained through the consolidation of the continuous polymer phase of a water-in-oil (W/O emulsion. Here, we show that the morphology of the dispersed phase in a poly(lactic-co-glycolic acid, PLGA matrix can be optimized by combining an effective mild temperature drying process with the addition of maltose as a densifying compound for the water phase of the emulsion. The influence of this addition on final stability and consequent optimal pore distribution was theoretically and experimentally confirmed. Samples were analyzed in terms of morphology on dried flat substrates and in terms of rheology and interfacial tension at the liquid state. While an increase of interfacial tension was found following the addition of maltose, the lower difference in density between the two emulsion phases coming from the addition of maltose allowed us to estimate a reduced creaming tendency confirmed by the experimental observations. Rheological measurements also confirmed an improved elastic behavior for the maltose-containing emulsion.
Oh, Hyeon-Jeong; Kang, Young-Gyu; Na, Tae-Young; Kim, Hyeon-Ji; Park, Jun Seong; Cho, Won-Jea; Lee, Mi-Ock
2013-08-25
Retinoids have been used as therapeutics for diverse skin diseases, but their side effects limit clinical usage. Here, we report that extracts of two soybeans, Glycine max and Rhynchosia nulubilis, and their ethyl acetate fractions increased the transcriptional activity of retinoic acid receptors (RARs), and that daidzin and genistin were the major constituents of the active fractions. Daidzin and its aglycone, daidzein, induced transcriptional activity of RAR and RARγ. FRET analysis demonstrated that daidzein, but not daidzin, bound both RAR and RARγ with EC50 values of 28μM and 40μM, respectively. Daidzein increased expression of mRNA of RARγ through direct binding of RAR and recruitment of p300 to the RARγ2 promoter. Further, mRNA and gelatinolytic activity of matrix metalloproteinase-9 were decreased by daidzein in HaCaT cells. Together, these results indicate that daidzein functions as a ligand of RAR that could be a candidate therapeutic for skin diseases.
Energy Technology Data Exchange (ETDEWEB)
Ishimaru, Masachika; Yokoyama, Ryuichi [Tokyo Metropolitan Univ., Hachioji, Tokyo (Japan); Shirai, Goro [Hosei Univ., Koganei, Tokyo (Japan); Niimura, Takahide [British Columbia Univ., Vancouver, BC (Canada)
2002-10-01
Power system stabilizing control has an important role in maintaining synchronism in power systems during major disturbances resulting from sudden changes of load and configuration. The thyristor- controlled series capacitor (TCSC) is one of the representative devices in flexible AC transmission systems. In this paper, robust TCSC controllers are applied to suppress disturbances in realistic power systems. H{sub {infinity}} control is adopted as the methodology of the robust controller design along with a linear matrix inequality (LMI), which solves the Lyapunov inequality without the weighting coefficients used in other control theories. In the proposed design, load changes are treated as a system uncertainty in the LMI approach. The proposed LMI -based approach is shown to be effective in the design of TCSC controllers to enhance robustness and response by simulations on a test system. (Author)
From Function to System: Advances in Choosing a Matrix Structure of the Translation Process
Directory of Open Access Journals (Sweden)
Ирина Николаевна Ремхе
2016-12-01
Full Text Available This article presents the authors’ view on the transition towards a new paradigm in the study of the translation process based on synergy, collaboration, networking and the cognitive structure of the translator’s mind. In the search for a hypothetical cognitive model of translation, a matrix model is represented to further enrich the interdisciplinary platform through understanding the conglomerate of the many sources involved in the act of translation and focusing on the role of the individual human being in translational cognition. The Map-Matrix Model comprises three levels of the translator’s mental space: Neurological, Representational and Conceptual. Each level corresponds to the inheritance relations between mapping patterns, clusters and frames. The model will be presented and interrogated through the results of a practical Think-aloud protocols experiment in order to give a better insight into the translation efficiency in terms of information processing and a clearer assumption of the feasibility of the concept.
Shunmuganathan, K. L.; A. Suresh
2012-01-01
In this study, an efficient feature fusion based technique for the classification of colour texture images in VisTex album is presented. Gray Level Co-occurrence Matrix (GLCM) and its associated texture features contrast, correlation, energy and homogeneity are used in the proposed approach. The proposed GLCM texture features are obtained from the original colour texture as well as the first non singleton dimension of the same image. These features are fused at feature level to classify the c...
Takahashi, Daisuke A
2015-01-01
The matrix-generalized Bogoliubov-de Gennes systems are recently considered by the present author [arXiv:1509.04242], and the time-dependent and self-consistent multi-soliton solutions are constructed based on the ansatz method. In this paper, restricting the problem to the static case, we exhaustively determine the self-consistent solutions using the inverse scattering theory. Solving the gap equation, we rigorously prove that the self-consistent potential must be reflectionless. As a supplementary topic, we elucidate the relation between the stationary self-consistent potentials and the soliton solutions in the matrix nonlinear Schr\\"odinger equation. The asymptotic formulae of multi-soliton solutions for sufficiently isolated solitons are also presented.
Giesbertz, Klaas J H; Baerends, Evert Jan
2013-01-01
Recently, we have demonstrated that the problems finding a suitable adiabatic approximation in time-dependent one-body reduced density matrix functional theory can be remedied by introducing an additional degree of freedom to describe the system: the phase of the natural orbitals [Phys. Rev. Lett. 105, 013002 (2010), J. Chem. Phys. 133, 174119 (2010)]. In this article we will show in detail how the frequency-dependent response equations give the proper static limit ($\\omega\\to0$), including the perturbation in the chemical potential, which is required in static response theory to ensure the correct number of particles. Additionally we show results for the polarizability for H$_2$ and compare the performance of two different two-electron functionals: the phase-including L\\"owdin-Shull functional and the density matrix form of the L\\"owdin-Shull functional.
Koo, Min-Sung; Choi, Ho-Lim
2016-04-01
We consider the global regulation problem of uncertain systems with both triangular and non-triangular nonlinearities. For the global regulation in the presence of non-triangular nonlinearities, we propose a dynamic gain controller designed by using power order conditions and a matrix inequality condition imposed on non-triangular nonlinearities. Compared with the existing results, the proposed control method allows a class of nonlinear systems that have not been treated before. Analysis and examples are given to prove the general applicability of our control method.
Institute of Scientific and Technical Information of China (English)
Cai-Zhi SUN; Wei ZOU; Xue-Yu LIN
2004-01-01
In the management of unconfined aquifer systems, if the thickness of the aquifer is very small and the drawdown is relatively big, errors may arise when the superposition principle is adopted.directly. In allusion to this limitation, a new management model for the management of unconfined aquifer systems called two-level response matrix method is put forward. This method is applied in groundwater resources management in Shenyang city. The managing results show that this methodcan, in some degree, increase the efficiency of management and decrease the risk of management.
Directory of Open Access Journals (Sweden)
Guohu Feng
2012-06-01
Full Text Available A matrix Kalman filter (MKF has been implemented for an integrated navigation system using visual/inertial/magnetic sensors. The MKF rearranges the original nonlinear process model in a pseudo-linear process model. We employ the observability rank criterion based on Lie derivatives to verify the conditions under which the nonlinear system is observable. It has been proved that such observability conditions are: (a at least one degree of rotational freedom is excited, and (b at least two linearly independent horizontal lines and one vertical line are observed. Experimental results have validated the correctness of these observability conditions.
Franklin, Joel N
2003-01-01
Mathematically rigorous introduction covers vector and matrix norms, the condition-number of a matrix, positive and irreducible matrices, much more. Only elementary algebra and calculus required. Includes problem-solving exercises. 1968 edition.
2015-01-01
In this paper, a robust algorithm for fault diagnosis of power system equipment based on a failure-sensitive matrix (FSM) is presented. The FSM is a dynamic matrix structure updated by multiple measurements (online) and test results (offline) on the systems. The algorithm uses many different artificial intelligence and expert system methods for adaptively detecting the location of faults, emerging failures, and causes of failures. In this algorithm, all data obtained from the power transforme...
Hepatic Fatty Acid Oxidation Restrains Systemic Catabolism during Starvation
Directory of Open Access Journals (Sweden)
Jieun Lee
2016-06-01
Full Text Available The liver is critical for maintaining systemic energy balance during starvation. To understand the role of hepatic fatty acid β-oxidation on this process, we generated mice with a liver-specific knockout of carnitine palmitoyltransferase 2 (Cpt2L−/−, an obligate step in mitochondrial long-chain fatty acid β-oxidation. Fasting induced hepatic steatosis and serum dyslipidemia with an absence of circulating ketones, while blood glucose remained normal. Systemic energy homeostasis was largely maintained in fasting Cpt2L−/− mice by adaptations in hepatic and systemic oxidative gene expression mediated in part by Pparα target genes including procatabolic hepatokines Fgf21, Gdf15, and Igfbp1. Feeding a ketogenic diet to Cpt2L−/− mice resulted in severe hepatomegaly, liver damage, and death with a complete absence of adipose triglyceride stores. These data show that hepatic fatty acid oxidation is not required for survival during acute food deprivation but essential for constraining adipocyte lipolysis and regulating systemic catabolism when glucose is limiting.
Systems solutions by lactic acid bacteria: from paradigms to practice.
de Vos, Willem M
2011-08-30
Lactic acid bacteria are among the powerhouses of the food industry, colonize the surfaces of plants and animals, and contribute to our health and well-being. The genomic characterization of LAB has rocketed and presently over 100 complete or nearly complete genomes are available, many of which serve as scientific paradigms. Moreover, functional and comparative metagenomic studies are taking off and provide a wealth of insight in the activity of lactic acid bacteria used in a variety of applications, ranging from starters in complex fermentations to their marketing as probiotics. In this new era of high throughput analysis, biology has become big science. Hence, there is a need to systematically store the generated information, apply this in an intelligent way, and provide modalities for constructing self-learning systems that can be used for future improvements. This review addresses these systems solutions with a state of the art overview of the present paradigms that relate to the use of lactic acid bacteria in industrial applications. Moreover, an outlook is presented of the future developments that include the transition into practice as well as the use of lactic acid bacteria in synthetic biology and other next generation applications.
Labrecque, Charles; Whitty-Léveillé, Laurence; Larivière, Dominic
2013-11-01
A new cloud point extraction procedure has been developed for the quantification of plutonium(IV) in environmental samples. The separation procedure can be either coupled to inductively coupled plasma mass spectrometry (ICPMS) or α spectrometry for plutonium quantification. The method uses a combination of selective ligand (P,P'-di(2-ethylhexyl) methanediphosphonic acid (H2DEH[MDP])) and micelle shielding by bromine formation to enable quantitative extraction of Pu in highly acidic solutions. Cross-optimization of all parameters (nonionic and ionic surfactant, chelating agent, bromate, bromide, and pH) led to optimal of the extraction conditions. Figures of merit of the method for the detection using α spectrometry and ICPMS are reported (limit of detection, limit of quantification, minimal detectable activity, and recovery). Quantitative extractions (>95%) were obtained for a wide variety of aqueous and digested samples (synthetic urine, wastewater, drinking water, seawater, and soil samples). The method features the first successful coupling between α spectrometry and cloud point extraction and is the first demonstration of CPE suitability with metaborate fusion as a sample preparation approach, techniques used extensively in nuclear industries.
Maxim, Voichita; Lojacono, Xavier; Hilaire, Estelle; Krimmer, Jochen; Testa, Etienne; Dauvergne, Denis; Magnin, Isabelle; Prost, Rémy
2016-01-01
This paper addresses the problem of evaluating the system matrix and the sensitivity for iterative reconstruction in Compton camera imaging. Proposed models and numerical calculation strategies are compared through the influence they have on the three-dimensional reconstructed images. The study attempts to address four questions. First, it proposes an analytic model for the system matrix. Second, it suggests a method for its numerical validation with Monte Carlo simulated data. Third, it compares analytical models of the sensitivity factors with Monte Carlo simulated values. Finally, it shows how the system matrix and the sensitivity calculation strategies influence the quality of the reconstructed images.
Eichler, C.; Mlynek, J.; Butscher, J.; Kurpiers, P.; Hammerer, K.; Osborne, T. J.; Wallraff, A.
2015-10-01
Improving the understanding of strongly correlated quantum many-body systems such as gases of interacting atoms or electrons is one of the most important challenges in modern condensed matter physics, materials research, and chemistry. Enormous progress has been made in the past decades in developing both classical and quantum approaches to calculate, simulate, and experimentally probe the properties of such systems. In this work, we use a combination of classical and quantum methods to experimentally explore the properties of an interacting quantum gas by creating experimental realizations of continuous matrix product states—a class of states that has proven extremely powerful as a variational ansatz for numerical simulations. By systematically preparing and probing these states using a circuit quantum electrodynamics system, we experimentally determine a good approximation to the ground-state wave function of the Lieb-Liniger Hamiltonian, which describes an interacting Bose gas in one dimension. Since the simulated Hamiltonian is encoded in the measurement observable rather than the controlled quantum system, this approach has the potential to apply to a variety of models including those involving multicomponent interacting fields. Our findings also hint at the possibility of experimentally exploring general properties of matrix product states and entanglement theory. The scheme presented here is applicable to a broad range of systems exploiting strong and tunable light-matter interactions.
Prasetyo, Adri D; Prager, Welf; Rubin, Mark G; Moretti, Ernesto A; Nikolis, Andreas
2016-01-01
Background Cohesive monophasic polydensified fillers show unique viscoelastic properties and variable density of hyaluronic acid, allowing for a homogeneous tissue integration and distribution of the material. Objective The aim of this paper was to review the clinical data regarding the performance, tolerability, and safety of the Belotero® fillers for soft-tissue augmentation and rejuvenation. Methods A literature search was performed up until May 31, 2015 to identify all relevant articles on Belotero® fillers (Basic/Balance, Hydro, Soft, Intense, Volume) and equivalent products (Esthélis®, Mesolis®, Fortélis®, Modélis®). Results This comprehensive review included 26 papers. Findings from three randomized controlled trials showed a greater reduction in nasolabial fold severity with Belotero® Basic/Balance than with collagen (at 8, 12, 16, and 24 weeks, n=118) and Restylane® (at 4 weeks, n=40), and higher patient satisfaction with Belotero® Intense than with Perlane® (at 2 weeks, n=20). With Belotero® Basic/Balance, an improvement of at least 1 point on the severity scale can be expected in ~80% of patients 1–6 months after injection, with an effect still visible at 8–12 months. Positive findings were also reported with Belotero® Volume (no reduction in hyaluronic acid volume at 12 months, as demonstrated by magnetic resonance imaging), Soft (improvement in the esthetic outcomes when used in a sequential approach), and Hydro (improvement in skin appearance in all patients). The most common adverse effects were mild-to-moderate erythema, edema, and hematoma, most of which were temporary. There were no reports of Tyndall effect, nodules, granulomas, or tissue necrosis. Conclusion Clinical evidence indicates sustainable esthetic effects, good safety profile, and long-term tolerability of the Belotero® fillers, particularly Belotero® Basic/Balance and Intense. PMID:27660479
Developing nucleic acid-based electrical detection systems
Directory of Open Access Journals (Sweden)
Gabig-Ciminska Magdalena
2006-03-01
Full Text Available Abstract Development of nucleic acid-based detection systems is the main focus of many research groups and high technology companies. The enormous work done in this field is particularly due to the broad versatility and variety of these sensing devices. From optical to electrical systems, from label-dependent to label-free approaches, from single to multi-analyte and array formats, this wide range of possibilities makes the research field very diversified and competitive. New challenges and requirements for an ideal detector suitable for nucleic acid analysis include high sensitivity and high specificity protocol that can be completed in a relatively short time offering at the same time low detection limit. Moreover, systems that can be miniaturized and automated present a significant advantage over conventional technology, especially if detection is needed in the field. Electrical system technology for nucleic acid-based detection is an enabling mode for making miniaturized to micro- and nanometer scale bio-monitoring devices via the fusion of modern micro- and nanofabrication technology and molecular biotechnology. The electrical biosensors that rely on the conversion of the Watson-Crick base-pair recognition event into a useful electrical signal are advancing rapidly, and recently are receiving much attention as a valuable tool for microbial pathogen detection. Pathogens may pose a serious threat to humans, animal and plants, thus their detection and analysis is a significant element of public health. Although different conventional methods for detection of pathogenic microorganisms and their toxins exist and are currently being applied, improvements of molecular-based detection methodologies have changed these traditional detection techniques and introduced a new era of rapid, miniaturized and automated electrical chip detection technologies into pathogen identification sector. In this review some developments and current directions in
Institute of Scientific and Technical Information of China (English)
Haifeng Zhu; Liren Wang; Pinggui Tang; Yongjun Feng; Dianqing Li
2012-01-01
Incorporation of anions of Acid Red 114 dye (1,3-naphthalenedisulfonic acid,8-[2-[3,3'-dimethyl-4'-[2-[4-[[(4-methylphenyl)sulfonyl]oxy] phenyl]diazenyl] [1,1'-biphenyl]-4-yl]diazenyl]-7-hydroxy-,disodium salt) (denoted as NPDA) into ZnAl-layered double hydroxides (LDHs) has been carried out by an anionexchange method in an effort to improve their thermal stability and light fastness.After intercalation of NPDA anions,the interlayer distance of the LDHs increases from 0.87 to 2.18nm,confirming their incorporation into the interlayer galleries of the LDHs host.Infrared spectroscopy and thermogravimetric analysis revealed the presence of host-guest interactions between LDHs layers and NPDA anions.The thermal stability of NPDA and ZnAl-NPDA-LDHs was compared by thermogravimetric-differential thermal analysis,UV-visible spectroscopy and infrared spectroscopy.It was found that the thermal stability of NPDA anions was markedly improved by incorporation into the ZnAl-LDHs matrix,while the light fastness was also enhanced.
Directory of Open Access Journals (Sweden)
K. L. Shunmuganathan
2012-01-01
Full Text Available In this study, an efficient feature fusion based technique for the classification of colour texture images in VisTex album is presented. Gray Level Co-occurrence Matrix (GLCM and its associated texture features contrast, correlation, energy and homogeneity are used in the proposed approach. The proposed GLCM texture features are obtained from the original colour texture as well as the first non singleton dimension of the same image. These features are fused at feature level to classify the colour texture image using nearest neighbor classifier. The results demonstrate that the proposed fusion of difference image GLCM features is much more efficient than the original GLCM features.