An Analysis of Nondestructive Evaluation Techniques for Polymer Matrix Composite Sandwich Materials

NASA Technical Reports Server (NTRS)

Cosgriff, Laura M.; Roberts, Gary D.; Binienda, Wieslaw K.; Zheng, Diahua; Averbeck, Timothy; Roth, Donald J.; Jeanneau, Philippe

2006-01-01

Structural sandwich materials composed of triaxially braided polymer matrix composite material face sheets sandwiching a foam core are being utilized for applications including aerospace components and recreational equipment. Since full scale components are being made from these sandwich materials, it is necessary to develop proper inspection practices for their manufacture and in-field use. Specifically, nondestructive evaluation (NDE) techniques need to be investigated for analysis of components made from these materials. Hockey blades made from sandwich materials and a flat sandwich sample were examined with multiple NDE techniques including thermographic, radiographic, and shearographic methods to investigate damage induced in the blades and flat panel components. Hockey blades used during actual play and a flat polymer matrix composite sandwich sample with damage inserted into the foam core were investigated with each technique. NDE images from the samples were presented and discussed. Structural elements within each blade were observed with radiographic imaging. Damaged regions and some structural elements of the hockey blades were identified with thermographic imaging. Structural elements, damaged regions, and other material variations were detected in the hockey blades with shearography. Each technique s advantages and disadvantages were considered in making recommendations for inspection of components made from these types of materials.

Evidence of low molecular weight components in the organic matrix of the reef building coral, Stylophora pistillata.

PubMed

Puverel, S; Houlbrèque, F; Tambutté, E; Zoccola, D; Payan, P; Caminiti, N; Tambutté, S; Allemand, D

2007-08-01

Biominerals contain both inorganic and organic components. Organic components are collectively termed the organic matrix, and this matrix has been reported to play a crucial role in mineralization. Several matrix proteins have been characterized in vertebrates, but only a few in invertebrates, primarily in Molluscs and Echinoderms. Methods classically used to extract organic matrix proteins eliminate potential low molecular weight matrix components, since cut-offs ranging from 3.5 to 10 kDa are used to desalt matrix extracts. Consequently, the presence of such components remains unknown and these are never subjected to further analyses. In the present study, we have used microcolonies from the Scleractinian coral Stylophora pistillata to study newly synthesized matrix components by labelling them with 14C-labelled amino acids. Radioactive matrix components were investigated by a method in which both total organic matrix and fractions of matrix below and above 5 kDa were analyzed. Using this method and SDS-PAGE analyses, we were able to detect the presence of low molecular mass matrix components (<3.5 kDa), but no free amino acids in the skeletal organic matrix. Since more than 98% of the 14C-labelled amino acids were incorporated into low molecular weight molecules, these probably form the bulk of newly synthesized organic matrix components. Our results suggest that these low molecular weight components may be peptides, which can be involved in the regulation of coral skeleton mineralization.

Fabrication and Testing of Ceramic Matrix Composite Propulsion Components

NASA Technical Reports Server (NTRS)

Effinger, Michael R.; Clinton, R. G., Jr.; Dennis, Jay; Elam, Sandy; Genge, Gary; Eckel, Andy; Jaskowiak, Martha H.; Kiser, J. Douglas; Lang, Jerry

2000-01-01

A viewgraph presentation outlines NASA's goals for the Second and Third Generation Reusable Launch Vehicles, placing emphasis on improving safety and decreasing the cost of transporting payloads to orbit. The use of ceramic matrix composite (CMC) technology is discussed. The development of CMC components, such as the Simplex CMC Blisk, cooled CMC nozzle ramps, cooled CMC thrust chambers, and CMC gas generators, are described, including challenges, test results, and likely future developments.

Advanced Ceramic Matrix Composites (CMCs) for High Temperature Applications

NASA Technical Reports Server (NTRS)

Singh, M.

2005-01-01

Advanced ceramic matrix composites (CMCs) are enabling materials for a number of demanding applications in aerospace, energy, and nuclear industries. In the aerospace systems, these materials are being considered for applications in hot sections of jet engines such as the combustor liner, vanes, nozzle components, nose cones, leading edges of reentry vehicles, and space propulsion components. Applications in the energy and environmental industries include radiant heater tubes, heat exchangers, heat recuperators, gas and diesel particulate filters, and components for land based turbines for power generation. These materials are also being considered for use in the first wall and blanket components of fusion reactors. In the last few years, a number of CMC components have been developed and successfully tested for various aerospace and ground based applications. However, a number of challenges still remain slowing the wide scale implementation of these materials. They include robust fabrication and manufacturing, assembly and integration, coatings, property modeling and life prediction, design codes and databases, repair and refurbishment, and cost. Fabrication of net and complex shape components with high density and tailorable matrix properties is quite expensive, and even then various desirable properties are not achievable. In this presentation, a number of examples of successful CMC component development and testing will be provided. In addition, critical need for robust manufacturing, joining and assembly technologies in successful implementation of these systems will be discussed.

System and plastic scintillator for discrimination of thermal neutron, fast neutron, and gamma radiation

DOEpatents

Zaitseva, Natalia P.; Carman, M. Leslie; Faust, Michelle A.; Glenn, Andrew M.; Martinez, H. Paul; Pawelczak, Iwona A.; Payne, Stephen A.

2017-05-16

A scintillator material according to one embodiment includes a polymer matrix; a primary dye in the polymer matrix, the primary dye being a fluorescent dye, the primary dye being present in an amount of 3 wt % or more; and at least one component in the polymer matrix, the component being selected from a group consisting of B, Li, Gd, a B-containing compound, a Li-containing compound and a Gd-containing compound, wherein the scintillator material exhibits an optical response signature for thermal neutrons that is different than an optical response signature for fast neutrons and gamma rays. A system according to one embodiment includes a scintillator material as disclosed herein and a photodetector for detecting the response of the material to fast neutron, thermal neutron and gamma ray irradiation.

Deghosting based on the transmission matrix method

NASA Astrophysics Data System (ADS)

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

2017-12-01

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

Distribution of a low dose compound within pharmaceutical tablet by using multivariate curve resolution on Raman hyperspectral images.

PubMed

Boiret, Mathieu; de Juan, Anna; Gorretta, Nathalie; Ginot, Yves-Michel; Roger, Jean-Michel

2015-01-25

In this work, Raman hyperspectral images and multivariate curve resolution-alternating least squares (MCR-ALS) are used to study the distribution of actives and excipients within a pharmaceutical drug product. This article is mainly focused on the distribution of a low dose constituent. Different approaches are compared, using initially filtered or non-filtered data, or using a column-wise augmented dataset before starting the MCR-ALS iterative process including appended information on the low dose component. In the studied formulation, magnesium stearate is used as a lubricant to improve powder flowability. With a theoretical concentration of 0.5% (w/w) in the drug product, the spectral variance contained in the data is weak. By using a principal component analysis (PCA) filtered dataset as a first step of the MCR-ALS approach, the lubricant information is lost in the non-explained variance and its associated distribution in the tablet cannot be highlighted. A sufficient number of components to generate the PCA noise-filtered matrix has to be used in order to keep the lubricant variability within the data set analyzed or, otherwise, work with the raw non-filtered data. Different models are built using an increasing number of components to perform the PCA reduction. It is shown that the magnesium stearate information can be extracted from a PCA model using a minimum of 20 components. In the last part, a column-wise augmented matrix, including a reference spectrum of the lubricant, is used before starting MCR-ALS process. PCA reduction is performed on the augmented matrix, so the magnesium stearate contribution is included within the MCR-ALS calculations. By using an appropriate PCA reduction, with a sufficient number of components, or by using an augmented dataset including appended information on the low dose component, the distribution of the two actives, the two main excipients and the low dose lubricant are correctly recovered. Copyright © 2014 Elsevier B.V. All rights reserved.

A major protein component of the Bacillus subtilis biofilm matrix.

PubMed

Branda, Steven S; Chu, Frances; Kearns, Daniel B; Losick, Richard; Kolter, Roberto

2006-02-01

Microbes construct structurally complex multicellular communities (biofilms) through production of an extracellular matrix. Here we present evidence from scanning electron microscopy showing that a wild strain of the Gram positive bacterium Bacillus subtilis builds such a matrix. Genetic, biochemical and cytological evidence indicates that the matrix is composed predominantly of a protein component, TasA, and an exopolysaccharide component. The absence of TasA or the exopolysaccharide resulted in a residual matrix, while the absence of both components led to complete failure to form complex multicellular communities. Extracellular complementation experiments revealed that a functional matrix can be assembled even when TasA and the exopolysaccharide are produced by different cells, reinforcing the view that the components contribute to matrix formation in an extracellular manner. Having defined the major components of the biofilm matrix and the control of their synthesis by the global regulator SinR, we present a working model for how B. subtilis switches between nomadic and sedentary lifestyles.

Identification of Extracellular Matrix Components and Biological Factors in Micronized Dehydrated Human Amnion/Chorion Membrane

PubMed Central

Lei, Jennifer; Priddy, Lauren B.; Lim, Jeremy J.; Massee, Michelle; Koob, Thomas J.

2017-01-01

Objective: The use of bioactive extracellular matrix (ECM) grafts such as amniotic membranes is an attractive treatment option for enhancing wound repair. In this study, the concentrations, activity, and distribution of matrix components, growth factors, proteases, and inhibitors were evaluated in PURION® Processed, micronized, dehydrated human amnion/chorion membrane (dHACM; MiMedx Group, Inc.). Approach: ECM components in dHACM tissue were assessed by using immunohistochemical staining, and growth factors, cytokines, proteases, and inhibitors were quantified by using single and multiplex ELISAs. The activities of proteases that were native to the tissue were determined via gelatin zymography and EnzChek® activity assay. Results: dHACM tissue contained the ECM components collagens I and IV, hyaluronic acid, heparin sulfate proteoglycans, fibronectin, and laminin. In addition, numerous growth factors, cytokines, chemokines, proteases, and protease inhibitors that are known to play a role in the wound-healing process were quantified in dHACM. Though matrix metalloproteinases (MMPs) were present in dHACM tissues, inhibitors of MMPs overwhelmingly outnumbered the MMP enzymes by an overall molar ratio of 28:1. Protease activity assays revealed that the MMPs in the tissue existed primarily either in their latent form or complexed with inhibitors. Innovation: This is the first study to characterize components that function in wound healing, including inhibitor and protease content and activity, in micronized dHACM. Conclusion: A variety of matrix components and growth factors, as well as proteases and their inhibitors, were identified in micronized dHACM, providing a better understanding of how micronized dHACM tissue can be used to effectively promote wound repair. PMID:28224047

Identification of Extracellular Matrix Components and Biological Factors in Micronized Dehydrated Human Amnion/Chorion Membrane.

PubMed

Lei, Jennifer; Priddy, Lauren B; Lim, Jeremy J; Massee, Michelle; Koob, Thomas J

2017-02-01

Objective: The use of bioactive extracellular matrix (ECM) grafts such as amniotic membranes is an attractive treatment option for enhancing wound repair. In this study, the concentrations, activity, and distribution of matrix components, growth factors, proteases, and inhibitors were evaluated in PURION ® Processed, micronized, dehydrated human amnion/chorion membrane (dHACM; MiMedx Group, Inc.). Approach: ECM components in dHACM tissue were assessed by using immunohistochemical staining, and growth factors, cytokines, proteases, and inhibitors were quantified by using single and multiplex ELISAs. The activities of proteases that were native to the tissue were determined via gelatin zymography and EnzChek ® activity assay. Results: dHACM tissue contained the ECM components collagens I and IV, hyaluronic acid, heparin sulfate proteoglycans, fibronectin, and laminin. In addition, numerous growth factors, cytokines, chemokines, proteases, and protease inhibitors that are known to play a role in the wound-healing process were quantified in dHACM. Though matrix metalloproteinases (MMPs) were present in dHACM tissues, inhibitors of MMPs overwhelmingly outnumbered the MMP enzymes by an overall molar ratio of 28:1. Protease activity assays revealed that the MMPs in the tissue existed primarily either in their latent form or complexed with inhibitors. Innovation: This is the first study to characterize components that function in wound healing, including inhibitor and protease content and activity, in micronized dHACM. Conclusion: A variety of matrix components and growth factors, as well as proteases and their inhibitors, were identified in micronized dHACM, providing a better understanding of how micronized dHACM tissue can be used to effectively promote wound repair.

Development and Justification of a Risk Evaluation Matrix To Guide Chemical Testing Necessary To Select and Qualify Plastic Components Used in Production Systems for Pharmaceutical Products.

PubMed

Jenke, Dennis

2015-01-01

An accelerating trend in the pharmaceutical industry is the use of plastic components in systems used to produce an active pharmaceutical ingredient or a finished drug product. If the active pharmaceutical ingredient, the finished drug product, or any solution used to generate them (for example, a process stream such as media, buffers, eluents, and the like) is contacted by a plastic component at any time during the production process, substances leached from the component may accumulate in the active pharmaceutical ingredient or finished drug product, affecting its safety and/or efficacy. In this article the author develops and justifies a semi-quantitative risk evaluation matrix that is used to determine the amount and rigor of component testing necessary and appropriate to establish that the component is chemically suitable for its intended use. By considering key properties of the component, the contact medium, the contact conditions, and the active pharmaceutical ingredient's or finished drug product's clinical conditions of use, use of the risk evaluation matrix produces a risk score whose magnitude reflects the accumulated risk that the component will interact with the contact solution to such an extent that component-related extractables will accumulate in the active pharmaceutical ingredient or finished drug product as leachables at levels sufficiently high to adversely affect user safety. The magnitude of the risk score establishes the amount and rigor of the testing that is required to select and qualify the component, and such testing is broadly grouped into three categories: baseline assessment, general testing, and full testing (extractables profiling). Production suites used to generate pharmaceuticals can include plastic components. It is possible that substances in the components could leach into manufacturing solutions and accumulate in the pharmaceutical product. In this article the author develops and justifies a semi-quantitative risk evaluation matrix that can be used to determine the amount and rigor of component testing that may be necessary and appropriate to establish that the component is suitable for its intended use. Use of the risk evaluation matrix allows a user of a component to determine the type and amount of testing that should be performed to establish the patient safety risk associated with using that component in order to manufacture an active pharmaceutical ingredient or a finished drug product. © PDA, Inc. 2015.

Microvascular Targets for Anti-Fibrotic Therapeutics

PubMed Central

Pu, Kai-Ming T.; Sava, Parid; Gonzalez, Anjelica L.

2013-01-01

Fibrosis is characterized by excessive extracellular matrix deposition and is the pathological outcome of repetitive tissue injury in many disorders. The accumulation of matrix disrupts the structure and function of the native tissue and can affect multiple organs including the lungs, heart, liver, and skin. Unfortunately, current therapies against the deadliest and most common fibrosis are ineffective. The pathogenesis of fibrosis is the result of aberrant wound healing, therefore, the microvasculature plays an important role, contributing through regulation of leukocyte recruitment, inflammation, and angiogenesis. Further exacerbating the condition, microvascular endothelial cells and pericytes can transdifferentiate into matrix depositing myofibroblasts. The contribution of the microvasculature to fibrotic progression makes its cellular components and acellular products attractive therapeutic targets. In this review, we examine many of the cytokine, matrix, and cellular microvascular components involved in fibrosis and discuss their potential as targets for fibrotic therapies with a particular focus on developing nanotechnologies. PMID:24348218

Provisional matrix: A role for versican and hyaluronan.

PubMed

Wight, Thomas N

2017-07-01

Hyaluronan and versican are extracellular matrix (ECM) components that are enriched in the provisional matrices that form during the early stages of development and disease. These two molecules interact to create pericellular "coats" and "open space" that facilitate cell sorting, proliferation, migration, and survival. Such complexes also impact the recruitment of leukocytes during development and in the early stages of disease. Once thought to be inert components of the ECM that help hold cells together, it is now quite clear that they play important roles in controlling cell phenotype, shaping tissue response to injury and maintaining tissue homeostasis. Conversion of hyaluronan-/versican-enriched provisional matrix to collagen-rich matrix is a "hallmark" of tissue fibrosis. Targeting the hyaluronan and versican content of provisional matrices in a variety of diseases including, cardiovascular disease and cancer, is becoming an attractive strategy for intervention. Copyright © 2016 Elsevier B.V. All rights reserved.

The extracellular matrix: Structure, composition, age-related differences, tools for analysis and applications for tissue engineering.

PubMed

Kular, Jaspreet K; Basu, Shouvik; Sharma, Ram I

2014-01-01

The extracellular matrix is a structural support network made up of diverse proteins, sugars and other components. It influences a wide number of cellular processes including migration, wound healing and differentiation, all of which is of particular interest to researchers in the field of tissue engineering. Understanding the composition and structure of the extracellular matrix will aid in exploring the ways the extracellular matrix can be utilised in tissue engineering applications especially as a scaffold. This review summarises the current knowledge of the composition, structure and functions of the extracellular matrix and introduces the effect of ageing on extracellular matrix remodelling and its contribution to cellular functions. Additionally, the current analytical technologies to study the extracellular matrix and extracellular matrix-related cellular processes are also reviewed.

Method of joining metallic and composite components

NASA Technical Reports Server (NTRS)

Semmes, Edmund B. (Inventor)

2010-01-01

A method is provided for joining a metallic member to a structure made of a composite matrix material. One or more surfaces of a portion of the metallic member that is to be joined to the composite matrix structure is provided with a plurality of outwardly projecting studs. The surface including the studs is brought into engagement with a portion of an uncured composite matrix material so that fibers of the composite matrix material intertwine with the studs, and the metallic member and composite structure form an assembly. The assembly is then companion cured so as to join the metallic member to the composite matrix material structure.

Emerging interactions between matrix components during biofilm development.

PubMed

Payne, David E; Boles, Blaise R

2016-02-01

Bacterial cells are most often found in the form of multicellular aggregates commonly referred to as biofilms. Biofilms offer their member cells several benefits, such as resistance to killing by antimicrobials and predation. During biofilm formation there is a production of extracellular substances that, upon assembly, constitute an extracellular matrix. The ability to generate a matrix encasing the microbial cells is a common feature of biofilms, but there is diversity in matrix composition and in interaction between matrix components. The different components of bacterial biofilm extracellular matrixes, known as matrix interactions, and resulting implications are discussed in this review.

Joint Procrustes Analysis for Simultaneous Nonsingular Transformation of Component Score and Loading Matrices

ERIC Educational Resources Information Center

Adachi, Kohei

2009-01-01

In component analysis solutions, post-multiplying a component score matrix by a nonsingular matrix can be compensated by applying its inverse to the corresponding loading matrix. To eliminate this indeterminacy on nonsingular transformation, we propose Joint Procrustes Analysis (JPA) in which component score and loading matrices are simultaneously…

Extracellular matrix components expression in human pluripotent stem cell-derived retinal organoids recapitulates retinogenesis in vivo and reveals an important role for IMPG1 and CD44 in the development of photoreceptors and interphotoreceptor matrix.

PubMed

Felemban, Majed; Dorgau, Birthe; Hunt, Nicola Claire; Hallam, Dean; Zerti, Darin; Bauer, Roman; Ding, Yuchun; Collin, Joseph; Steel, David; Krasnogor, Natalio; Al-Aama, Jumana; Lindsay, Susan; Mellough, Carla; Lako, Majlinda

2018-05-17

The extracellular matrix (ECM) plays an important role in numerous processes including cellular proliferation, differentiation, migration, maturation, adhesion guidance and axonal growth. To date, there has been no detailed analysis of the ECM distribution during retinal ontogenesis in humans and the functional importance of many ECM components is poorly understood. In this study, the expression of key ECM components in adult mouse and monkey retina, developing and adult human retina and retinal organoids derived from human pluripotent stem cells was studied. Our data indicate that basement membrane ECMs (Fibronectin and Collagen IV) were expressed in Bruch's membrane and the inner limiting membrane of the developing human retina, whilst the hyalectins (Versican and Brevican), cluster of differentiation 44 (CD44), photoreceptor-specific ECMs Interphotoreceptor Matrix Proteoglycan 1 (IMPG1) and Interphotoreceptor Matrix Proteoglycan 2 (IMPG2) were detected in the developing interphotoreceptor matrix (IPM). The expression of IMPG1, Versican and Brevican in the developing IPM was conserved between human developing retina and human pluripotent stem cell-derived retinal organoids. Blocking the action of CD44 and IMPG1 in pluripotent stem cell derived retinal organoids affected the development of photoreceptors, their inner/outer segments and connecting cilia and disrupted IPM formation, with IMPG1 having an earlier and more significant impact. Together, our data suggest an important role for IMPG1 and CD44 in the development of photoreceptors and IPM formation during human retinogenesis. The expression and the role of many extracellular matrix (ECM) components during human retinal development is not fully understood. In this study, expression of key ECM components (Collagen IV, Fibronectin, Brevican, Versican, IMPG1 and IMPG2) was investigated during human retinal ontogenesis. Collagen IV and Fibronectin were expressed in Bruch's membrane; whereas Brevican, Versican, IMPG1 & IMPG2 in the developing interphotoreceptor matrix (IPM). Retinal organoids were successfully generated from pluripotent stem cells. The expression of ECM components was examined in the retinal organoids and found to recapitulate human retinal development in vivo. Using functional blocking experiments, we were able to highlight an important role for IMPG1 and CD44 in the development of photoreceptors and IPM formation. Copyright © 2018 Acta Materialia Inc. All rights reserved.

Implementation Challenges for Ceramic Matrix Composites in High Temperature Applications

NASA Technical Reports Server (NTRS)

Singh, Mrityunjay

2004-01-01

Ceramic matrix composites are leading candidate materials for a number of applications in aeronautics, space, energy, electronics, nuclear, and transportation industries. In the aeronautics and space exploration systems, these materials are being considered for applications in hot sections of jet engines such as the combustor liner, nozzle components, nose cones, leading edges of reentry vehicles and space propulsion components. Applications in the energy and environmental industries include radiant heater tubes, heat exchangers, heat recuperators, gas and diesel particulate filters (DPFs), and components for land based turbines for power generation. These materials are also being considered for use in the first wall and blanket components of fusion reactors. There are a number of critical issues and challenges related to successful implementation of composite materials. Fabrication of net and complex shape components with high density and tailorable matrix properties is quite expensive, and even then various desirable properties are not achievable. In this presentation, microstructure and thermomechanical properties of composites fabricated by two techniques (chemical vapor infiltration and melt infiltration), will be presented. In addition, critical need for robust joining and assembly technologies in successful implementation of these systems will be discussed. Other implementation issues will be discussed along with advantages and benefits of using these materials for various components in high temperature applications.

Electric Field Activated Shape Memory Polymer Composite

NASA Technical Reports Server (NTRS)

Kang, Jin Ho (Inventor); Turner, Travis L. (Inventor); Siochi, Emilie J. (Inventor); Penner, Ronald K. (Inventor)

2017-01-01

Provided is an electrically activated shape memory polymer composite capable of thermal shape reformation using electric power to heat the composite through its matrix glass transition temperature. The composite includes an adaptable polymer matrix component using a diglycidyl ether resin, at least one substantially well-dispersed conductive or magnetic nano-filler component, and at least one elastic, laminated layer. Also provided are methods of preparing the composite and methods of activating the composite. A shape reformation of the composite is triggered by applying an electric field at DC and/or at a frequency above about 1.mu.Hz for a sufficient time.

Systems for column-based separations, methods of forming packed columns, and methods of purifying sample components

DOEpatents

Egorov, Oleg B.; O'Hara, Matthew J.; Grate, Jay W.; Chandler, Darrell P.; Brockman, Fred J.; Bruckner-Lea, Cynthia J.

2000-01-01

The invention encompasses systems for column-based separations, methods of packing and unpacking columns and methods of separating components of samples. In one aspect, the invention includes a method of packing and unpacking a column chamber, comprising: a) packing a matrix material within a column chamber to form a packed column; and b) after the packing, unpacking the matrix material from the column chamber without moving the column chamber. In another aspect, the invention includes a system for column-based separations, comprising: a) a fluid passageway, the fluid passageway comprising a column chamber and a flow path in fluid communication with the column chamber, the flow path being obstructed by a retaining material permeable to a carrier fluid and impermeable to a column matrix material suspended in the carrier fluid, the flow path extending through the column chamber and through the retaining material, the flow path being configured to form a packed column within the column chamber when a suspension of the fluid and the column matrix material is flowed along the flow path; and b) the fluid passageway extending through a valve intermediate the column chamber and the retaining material.

Systems For Column-Based Separations, Methods Of Forming Packed Columns, And Methods Of Purifying Sample Components

DOEpatents

Egorov, Oleg B.; O'Hara, Matthew J.; Grate, Jay W.; Chandler, Darrell P.; Brockman, Fred J.; Bruckner-Lea, Cynthia J.

2006-02-21

The invention encompasses systems for column-based separations, methods of packing and unpacking columns and methods of separating components of samples. In one aspect, the invention includes a method of packing and unpacking a column chamber, comprising: a) packing a matrix material within a column chamber to form a packed column; and b) after the packing, unpacking the matrix material from the column chamber without moving the column chamber. In another aspect, the invention includes a system for column-based separations, comprising: a) a fluid passageway, the fluid passageway comprising a column chamber and a flow path in fluid communication with the column chamber, the flow path being obstructed by a retaining material permeable to a carrier fluid and impermeable to a column matrix material suspended in the carrier fluid, the flow path extending through the column chamber and through the retaining material, the flow path being configured to form a packed column within the column chamber when a suspension of the fluid and the column matrix material is flowed along the flow path; and b) the fluid passageway extending through a valve intermediate the column chamber and the retaining material.

Systems For Column-Based Separations, Methods Of Forming Packed Columns, And Methods Of Purifying Sample Components.

DOEpatents

Egorov, Oleg B.; O'Hara, Matthew J.; Grate, Jay W.; Chandler, Darrell P.; Brockman, Fred J.; Bruckner-Lea, Cynthia J.

2004-08-24

The invention encompasses systems for column-based separations, methods of packing and unpacking columns and methods of separating components of samples. In one aspect, the invention includes a method of packing and unpacking a column chamber, comprising: a) packing a matrix material within a column chamber to form a packed column; and b) after the packing, unpacking the matrix material from the column chamber without moving the column chamber. In another aspect, the invention includes a system for column-based separations, comprising: a) a fluid passageway, the fluid passageway comprising a column chamber and a flow path in fluid communication with the column chamber, the flow path being obstructed by a retaining material permeable to a carrier fluid and impermeable to a column matrix material suspended in the carrier fluid, the flow path extending through the column chamber and through the retaining material, the flow path being configured to form a packed column within the column chamber when a suspension of the fluid and the column matrix material is flowed along the flow path; and b) the fluid passageway extending through a valve intermediate the column chamber and the retaining material.

Beyond Low Rank + Sparse: Multi-scale Low Rank Matrix Decomposition

PubMed Central

Ong, Frank; Lustig, Michael

2016-01-01

We present a natural generalization of the recent low rank + sparse matrix decomposition and consider the decomposition of matrices into components of multiple scales. Such decomposition is well motivated in practice as data matrices often exhibit local correlations in multiple scales. Concretely, we propose a multi-scale low rank modeling that represents a data matrix as a sum of block-wise low rank matrices with increasing scales of block sizes. We then consider the inverse problem of decomposing the data matrix into its multi-scale low rank components and approach the problem via a convex formulation. Theoretically, we show that under various incoherence conditions, the convex program recovers the multi-scale low rank components either exactly or approximately. Practically, we provide guidance on selecting the regularization parameters and incorporate cycle spinning to reduce blocking artifacts. Experimentally, we show that the multi-scale low rank decomposition provides a more intuitive decomposition than conventional low rank methods and demonstrate its effectiveness in four applications, including illumination normalization for face images, motion separation for surveillance videos, multi-scale modeling of the dynamic contrast enhanced magnetic resonance imaging and collaborative filtering exploiting age information. PMID:28450978

Giant gain from spontaneously generated coherence in Y-type double quantum dot structure

NASA Astrophysics Data System (ADS)

Al-Nashy, B.; Razzaghi, Sonia; Al-Musawi, Muwaffaq Abdullah; Rasooli Saghai, H.; Al-Khursan, Amin H.

A theoretical model was presented for linear susceptibility using density matrix theory for Y-configuration of double quantum dots (QDs) system including spontaneously generated coherence (SGC). Two SGC components are included for this system: V, and Λ subsystems. It is shown that at high V-component, the system have a giga gain. At low Λ-system component; it is possible to controls the light speed between superluminal and subluminal using one parameter by increasing SGC component of the V-system. This have applications in quantum information storage and spatially-varying temporal clock.

Method of waste stabilization with dewatered chemically bonded phosphate ceramics

DOEpatents

Wagh, Arun; Maloney, Martin D.

2010-06-29

A method of stabilizing a waste in a chemically bonded phosphate ceramic (CBPC). The method consists of preparing a slurry including the waste, water, an oxide binder, and a phosphate binder. The slurry is then allowed to cure to a solid, hydrated CBPC matrix. Next, bound water within the solid, hydrated CBPC matrix is removed. Typically, the bound water is removed by applying heat to the cured CBPC matrix. Preferably, the quantity of heat applied to the cured CBPC matrix is sufficient to drive off water bound within the hydrated CBPC matrix, but not to volatalize other non-water components of the matrix, such as metals and radioactive components. Typically, a temperature range of between 100.degree. C.-200.degree. C. will be sufficient. In another embodiment of the invention wherein the waste and water have been mixed prior to the preparation of the slurry, a select amount of water may be evaporated from the waste and water mixture prior to preparation of the slurry. Another aspect of the invention is a direct anyhydrous CBPC fabrication method wherein water is removed from the slurry by heating and mixing the slurry while allowing the slurry to cure. Additional aspects of the invention are ceramic matrix waste forms prepared by the methods disclosed above.

Advanced High Temperature Polymer Matrix Composites for Gas Turbine Engines Program Expansion

NASA Technical Reports Server (NTRS)

Hanley, David; Carella, John

1999-01-01

This document, submitted by AlliedSignal Engines (AE), a division of AlliedSignal Aerospace Company, presents the program final report for the Advanced High Temperature Polymer Matrix Composites for Gas Turbine Engines Program Expansion in compliance with data requirements in the statement of work, Contract No. NAS3-97003. This document includes: 1 -Technical Summary: a) Component Design, b) Manufacturing Process Selection, c) Vendor Selection, and d) Testing Validation: 2-Program Conclusion and Perspective. Also, see the Appendix at the back of this report. This report covers the program accomplishments from December 1, 1996, to August 24, 1998. The Advanced High Temperature PMC's for Gas Turbine Engines Program Expansion was a one year long, five task technical effort aimed at designing, fabricating and testing a turbine engine component using NASA's high temperature resin system AMB-21. The fiber material chosen was graphite T650-35, 3K, 8HS with UC-309 sizing. The first four tasks included component design and manufacturing, process selection, vendor selection, component fabrication and validation testing. The final task involved monthly financial and technical reports.

The neurovascular unit, matrix proteases, and innate inflammation.

PubMed

del Zoppo, Gregory J

2010-10-01

In the central nervous system, microvessel-neuron interactions appear highly coordinated. The rapid simultaneous responses of the microvasculature, neurons, and glia to focal ischemia in experimental ischemic stroke suggest that these responses could be viewed in a unitary fashion, rather than as individual components. The "neurovascular unit" consists of microvessels (endothelial cells-basal lamina matrix-astrocyte end-feet [and pericytes]), astrocytes, neurons and their axons, and other supporting cells that are likely to modulate the function of the "unit." Each cell component generates an inflammatory response to ischemia. Matrix metalloproteinase (MMP)-9 was first associated with hemorrhagic transformation following focal ischemia in an experimental model. A series of studies of ischemic stroke patients also suggests a relationship between MMP-9 levels and several consequences of ischemic injury, including hemorrhagic transformation. Recent experimental work suggests specific cell sources for MMP-9 generation and for matrix proteases from four distinct families that could impact neurovascular unit integrity. © 2010 New York Academy of Sciences.

Extracellular DNA facilitates the formation of functional amyloids in Staphylococcus aureus biofilms.

PubMed

Schwartz, Kelly; Ganesan, Mahesh; Payne, David E; Solomon, Michael J; Boles, Blaise R

2016-01-01

Persistent staphylococcal infections often involve surface-associated communities called biofilms. Staphylococcus aureus biofilm development is mediated by the co-ordinated production of the biofilm matrix, which can be composed of polysaccharides, extracellular DNA (eDNA) and proteins including amyloid fibers. The nature of the interactions between matrix components, and how these interactions contribute to the formation of matrix, remain unclear. Here we show that the presence of eDNA in S. aureus biofilms promotes the formation of amyloid fibers. Conditions or mutants that do not generate eDNA result in lack of amyloids during biofilm growth despite the amyloidogeneic subunits, phenol soluble modulin peptides, being produced. In vitro studies revealed that the presence of DNA promotes amyloid formation by PSM peptides. Thus, this work exposes a previously unacknowledged interaction between biofilm matrix components that furthers our understanding of functional amyloid formation and S. aureus biofilm biology. © 2015 The Authors. Molecular Microbiology published by John Wiley & Sons Ltd.

Large-scale biochemical profiling of the Candida albicans biofilm matrix: new compositional, structural, and functional insights.

PubMed

Lopez-Ribot, Jose L

2014-09-09

Among pathogenic fungi, Candida albicans is most frequently associated with biofilm formation, a lifestyle that is entirely different from the planktonic state. One of the distinguishing features of these biofilms is the presence of extracellular material, commonly referred to as the "biofilm matrix." The fungal biofilm matrix embeds sessile cells within these communities and plays important structural and physiological functions, including antifungal drug resistance with important clinical repercussions. This matrix is mostly self-produced by the fungal cells themselves and is composed of different types of biopolymers. In C. albicans, the main components of the biofilm matrix are carbohydrates, proteins, lipids, and DNA, but many of them remain unidentified and/or poorly characterized. In their recent article, Zarnowski et al. [mBio 5(4):e01333-14, 2014, doi:10.1128/mBio.01333-14] used a variety of biochemical and state-of-the-art "omic" approaches (glycomics, proteomics, and lipidomics) to identify and characterize unique biopolymers present in the C. albicans biofilm matrix. Besides generating a true "encyclopedic" catalog of individual moieties from each of the different macromolecular categories, results also provide important insights into structural and functional aspects of the fungal biofilm matrix, particularly the interaction between different components and the contribution of multiple matrix constituents to biofilm antifungal drug resistance. Copyright © 2014 Lopez-Ribot.

Condensed phase conversion and growth of nanorods and other materials instead of from vapor

DOEpatents

Geohegan, David B.; Seals, Roland D.; Puretzky, Alex A.; Fan, Xudong

2010-10-19

Compositions, systems and methods are described for condensed phase conversion and growth of nanorods and other materials. A method includes providing a condensed phase matrix material; and activating the condensed phase matrix material to produce a plurality of nanorods by condensed phase conversion and growth from the condensed phase matrix material instead of from vapor. The compositions are very strong. The compositions and methods provide advantages because they allow (1) formation rates of nanostructures necessary for reasonable production rates, and (2) the near net shaped production of component structures.

Condensed phase conversion and growth of nanorods instead of from vapor

DOEpatents

Geohegan, David B.; Seals, Roland D.; Puretzky, Alex A.; Fan, Xudong

2005-08-02

Compositions, systems and methods are described for condensed phase conversion and growth of nanorods and other materials. A method includes providing a condensed phase matrix material; and activating the condensed phase matrix material to produce a plurality of nanorods by condensed phase conversion and growth from the condensed chase matrix material instead of from vacor. The compositions are very strong. The compositions and methods provide advantages because they allow (1) formation rates of nanostructures necessary for reasonable production rates, and (2) the near net shaped production of component structures.

Factor Analysis and Counseling Research

ERIC Educational Resources Information Center

Weiss, David J.

1970-01-01

Topics discussed include factor analysis versus cluster analysis, analysis of Q correlation matrices, ipsativity and factor analysis, and tests for the significance of a correlation matrix prior to application of factor analytic techniques. Techniques for factor extraction discussed include principal components, canonical factor analysis, alpha…

Extracellular matrix structure governs invasion resistance in bacterial biofilms.

PubMed

Nadell, Carey D; Drescher, Knut; Wingreen, Ned S; Bassler, Bonnie L

2015-08-01

Many bacteria are highly adapted for life in communities, or biofilms. A defining feature of biofilms is the production of extracellular matrix that binds cells together. The biofilm matrix provides numerous fitness benefits, including protection from environmental stresses and enhanced nutrient availability. Here we investigate defense against biofilm invasion using the model bacterium Vibrio cholerae. We demonstrate that immotile cells, including those identical to the biofilm resident strain, are completely excluded from entry into resident biofilms. Motile cells can colonize and grow on the biofilm exterior, but are readily removed by shear forces. Protection from invasion into the biofilm interior is mediated by the secreted protein RbmA, which binds mother-daughter cell pairs to each other and to polysaccharide components of the matrix. RbmA, and the invasion protection it confers, strongly localize to the cell lineages that produce it.

RANDOM MATRIX DIAGONALIZATION--A COMPUTER PROGRAM

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

Fuchel, K.; Greibach, R.J.; Porter, C.E.

A computer prograra is described which generates random matrices, diagonalizes them and sorts appropriately the resulting eigenvalues and eigenvector components. FAP and FORTRAN listings for the IBM 7090 computer are included. (auth)

Damping characterization in large structures

NASA Technical Reports Server (NTRS)

Eke, Fidelis O.; Eke, Estelle M.

1991-01-01

This research project has as its main goal the development of methods for selecting the damping characteristics of components of a large structure or multibody system, in such a way as to produce some desired system damping characteristics. The main need for such an analytical device is in the simulation of the dynamics of multibody systems consisting, at least partially, of flexible components. The reason for this need is that all existing simulation codes for multibody systems require component-by-component characterization of complex systems, whereas requirements (including damping) often appear at the overall system level. The main goal was met in large part by the development of a method that will in fact synthesize component damping matrices from a given system damping matrix. The restrictions to the method are that the desired system damping matrix must be diagonal (which is almost always the case) and that interbody connections must be by simple hinges. In addition to the technical outcome, this project contributed positively to the educational and research infrastructure of Tuskegee University - a Historically Black Institution.

Ceramic Matrix Composites: High Temperature Effects. (Latest Citations from the Aerospace Database)

NASA Technical Reports Server (NTRS)

1997-01-01

The bibliography contains citations concerning the development and testing of ceramic matrix composites for high temperature use. Tests examining effects of the high temperatures on bond strength, thermal degradation, oxidation, thermal stress, thermal fatigue, and thermal expansion properties are referenced. Applications of the composites include space structures, gas turbine and engine components, control surfaces for spacecraft and transatmospheric vehicles, heat shields, and heat exchangers.

Breast carcinoma with a predominant duct-replacing component and chondroid matrix production.

PubMed

Tajima, Shogo; Koda, Kenji

2016-12-01

Breast carcinomas that produce chondroid matrix are extremely rare. If the carcinoma is invasive, it is classified as a matrix-producing carcinoma (MPC). Herein, we present a case of a breast carcinoma, which showed duct-replacing growth with chondroid matrix production. A 63-year-old woman underwent fine needle aspiration cytology for suspected malignancy, based on radiological findings. Cellular components showed sufficient atypia to allow a diagnosis of malignancy. A partial mastectomy was performed, and no mass-forming lesion was apparent in the surgically resected specimen. Histopathological examination showed that the carcinoma produced chondroid matrix and grew replacing ducts, which were associated with a small amount of an obvious invasive component without matrix production. Some parts of the duct-replacing component might take the form of expansile invasion due to the absence of residual duct-lining myoepithelial cells; it is difficult to decide whether the duct-replacing component is invasive or not. However, regarding a few tumor nests, they would be recognized as MPC-like intraductal components because of the focal presence of myoepithelial cells around them. Hence, this carcinoma could not be definitely diagnosed as a MPC, even though we believe they are closely related. This is the first reported case of a breast carcinoma displaying duct-replacing growth with chondroid matrix production.

Extracellular Matrix Degradation and Remodeling in Development and Disease

PubMed Central

Lu, Pengfei; Takai, Ken; Weaver, Valerie M.; Werb, Zena

2011-01-01

The extracellular matrix (ECM) serves diverse functions and is a major component of the cellular microenvironment. The ECM is a highly dynamic structure, constantly undergoing a remodeling process where ECM components are deposited, degraded, or otherwise modified. ECM dynamics are indispensible during restructuring of tissue architecture. ECM remodeling is an important mechanism whereby cell differentiation can be regulated, including processes such as the establishment and maintenance of stem cell niches, branching morphogenesis, angiogenesis, bone remodeling, and wound repair. In contrast, abnormal ECM dynamics lead to deregulated cell proliferation and invasion, failure of cell death, and loss of cell differentiation, resulting in congenital defects and pathological processes including tissue fibrosis and cancer. Understanding the mechanisms of ECM remodeling and its regulation, therefore, is essential for developing new therapeutic interventions for diseases and novel strategies for tissue engineering and regenerative medicine. PMID:21917992

[Network structures in biological systems].

PubMed

Oleskin, A V

2013-01-01

Network structures (networks) that have been extensively studied in the humanities are characterized by cohesion, a lack of a central control unit, and predominantly fractal properties. They are contrasted with structures that contain a single centre (hierarchies) as well as with those whose elements predominantly compete with one another (market-type structures). As far as biological systems are concerned, their network structures can be subdivided into a number of types involving different organizational mechanisms. Network organization is characteristic of various structural levels of biological systems ranging from single cells to integrated societies. These networks can be classified into two main subgroups: (i) flat (leaderless) network structures typical of systems that are composed of uniform elements and represent modular organisms or at least possess manifest integral properties and (ii) three-dimensional, partly hierarchical structures characterized by significant individual and/or intergroup (intercaste) differences between their elements. All network structures include an element that performs structural, protective, and communication-promoting functions. By analogy to cell structures, this element is denoted as the matrix of a network structure. The matrix includes a material and an immaterial component. The material component comprises various structures that belong to the whole structure and not to any of its elements per se. The immaterial (ideal) component of the matrix includes social norms and rules regulating network elements' behavior. These behavioral rules can be described in terms of algorithms. Algorithmization enables modeling the behavior of various network structures, particularly of neuron networks and their artificial analogs.

A proteomic study of the arabidopsis nuclear matrix.

PubMed

Calikowski, Tomasz T; Meulia, Tea; Meier, Iris

2003-10-01

The eukaryotic nucleus has been proposed to be organized by two interdependent nucleoprotein structures, the DNA-based chromatin and the RNA-dependent nuclear matrix. The functional composition and molecular organization of the second component have not yet been resolved. Here, we describe the isolation of the nuclear matrix from the model plant Arabidopsis, its initial characterization by confocal and electron microscopy, and the identification of 36 proteins by mass spectrometry. Electron microscopy of resinless samples confirmed a structure very similar to that described for the animal nuclear matrix. Two-dimensional gel electrophoresis resolved approximately 300 protein spots. Proteins were identified in batches by ESI tandem mass spectrometry after resolution by 1D SDS-PAGE. Among the identified proteins were a number of demonstrated or predicted Arabidopsis homologs of nucleolar proteins such as IMP4, Nop56, Nop58, fibrillarins, nucleolin, as well as ribosomal components and a putative histone deacetylase. Others included homologs of eEF-1, HSP/HSC70, and DnaJ, which have also been identified in the nucleolus or nuclear matrix of human cells, as well as a number of novel proteins with unknown function. This study is the first proteomic approach towards the characterization of a higher plant nuclear matrix. It demonstrates the striking similarities both in structure and protein composition of the operationally defined nuclear matrix across kingdoms whose unicellular ancestors have separated more than one billion years ago. Copyright 2003 Wiley-Liss, Inc.

Fast Minimum Variance Beamforming Based on Legendre Polynomials.

PubMed

Bae, MooHo; Park, Sung Bae; Kwon, Sung Jae

2016-09-01

Currently, minimum variance beamforming (MV) is actively investigated as a method that can improve the performance of an ultrasound beamformer, in terms of the lateral and contrast resolution. However, this method has the disadvantage of excessive computational complexity since the inverse spatial covariance matrix must be calculated. Some noteworthy methods among various attempts to solve this problem include beam space adaptive beamforming methods and the fast MV method based on principal component analysis, which are similar in that the original signal in the element space is transformed to another domain using an orthonormal basis matrix and the dimension of the covariance matrix is reduced by approximating the matrix only with important components of the matrix, hence making the inversion of the matrix very simple. Recently, we proposed a new method with further reduced computational demand that uses Legendre polynomials as the basis matrix for such a transformation. In this paper, we verify the efficacy of the proposed method through Field II simulations as well as in vitro and in vivo experiments. The results show that the approximation error of this method is less than or similar to those of the above-mentioned methods and that the lateral response of point targets and the contrast-to-speckle noise in anechoic cysts are also better than or similar to those methods when the dimensionality of the covariance matrices is reduced to the same dimension.

Continuous fiber ceramic matrix composites for heat engine components

NASA Technical Reports Server (NTRS)

Tripp, David E.

1988-01-01

High strength at elevated temperatures, low density, resistance to wear, and abundance of nonstrategic raw materials make structural ceramics attractive for advanced heat engine applications. Unfortunately, ceramics have a low fracture toughness and fail catastrophically because of overload, impact, and contact stresses. Ceramic matrix composites provide the means to achieve improved fracture toughness while retaining desirable characteristics, such as high strength and low density. Materials scientists and engineers are trying to develop the ideal fibers and matrices to achieve the optimum ceramic matrix composite properties. A need exists for the development of failure models for the design of ceramic matrix composite heat engine components. Phenomenological failure models are currently the most frequently used in industry, but they are deterministic and do not adequately describe ceramic matrix composite behavior. Semi-empirical models were proposed, which relate the failure of notched composite laminates to the stress a characteristic distance away from the notch. Shear lag models describe composite failure modes at the micromechanics level. The enhanced matrix cracking stress occurs at the same applied stress level predicted by the two models of steady state cracking. Finally, statistical models take into consideration the distribution in composite failure strength. The intent is to develop these models into computer algorithms for the failure analysis of ceramic matrix composites under monotonically increasing loads. The algorithms will be included in a postprocessor to general purpose finite element programs.

16 CFR 303.10 - Fiber content of special types of products.

Code of Federal Regulations, 2010 CFR

2010-01-01

... percentages of such components by weight. (2) If the components of such fibers are of a matrix-fibril configuration, the term matrix-fibril fiber or matrix fiber may be used in setting forth the information...% Biconstituent Fiber (65% Nylon, 35% Polyester) 80% Matrix Fiber (60% Nylon, 40% Polyester) 15% Polyester 5...

Precision pointing of scientific instruments on space station: The LFGGREC perspective

NASA Technical Reports Server (NTRS)

Blackwell, C. C.; Sirlin, S. W.; Laskin, R. A.

1988-01-01

An application of Lyapunov function-gradient-generated robustness-enhancing control (LFGGREC) is explored. The attention is directed to a reduced-complexity representation of the pointing problem presented by the system composed of the Space Infrared Telescope Facility gimbaled to a space station configuration. Uncertainties include disturbance forces applied in the crew compartment area and control moments applied to adjacent scientific payloads (modeled as disturbance moments). Also included are uncertainties in gimbal friction and in the structural component of the system, as reflected in the inertia matrix, the damping matrix, and the stiffness matrix, and the effect of the ignored vibrational dynamics of the structure. The emphasis is on the adaptation of LFGGREC to this particular configuration and on the robustness analysis.

Does the Coherent Lidar System Corroborate Non-Interaction of Waves (NIW)?

NASA Technical Reports Server (NTRS)

Prasad, Narasimha S.; Roychoudhari, Chandrasekhar

2013-01-01

The NIW (non-interaction of waves) property has been proposed by one of the coauthors. The NIW property states that in the absence of any "obstructing" detectors, all the Huygens-Fresnel secondary wavelets will continue to propagate unhindered and without interacting (interfering) with each other. Since a coherent lidar system incorporates complex behaviors of optical components with different polarizations including circular polarization for the transmitted radiation, then the question arises whether the NIW principle accommodate elliptical polarization of light. Elliptical polarization presumes the summation of orthogonally polarized electric field vectors which contradicts the NIW principle. In this paper, we present working of a coherent lidar system using Jones matrix formulation. The Jones matrix elements represent the anisotropic dipolar properties of molecules of optical components. Accordingly, when we use the Jones matrix methodology to analyze the coherent lidar system, we find that the system behavior is congruent with the NIW property.

Structures Division

NASA Technical Reports Server (NTRS)

1997-01-01

The NASA Lewis Research Center Structures Division is an international leader and pioneer in developing new structural analysis, life prediction, and failure analysis related to rotating machinery and more specifically to hot section components in air-breathing aircraft engines and spacecraft propulsion systems. The research consists of both deterministic and probabilistic methodology. Studies include, but are not limited to, high-cycle and low-cycle fatigue as well as material creep. Studies of structural failure are at both the micro- and macrolevels. Nondestructive evaluation methods related to structural reliability are developed, applied, and evaluated. Materials from which structural components are made, studied, and tested are monolithics and metal-matrix, polymer-matrix, and ceramic-matrix composites. Aeroelastic models are developed and used to determine the cyclic loading and life of fan and turbine blades. Life models are developed and tested for bearings, seals, and other mechanical components, such as magnetic suspensions. Results of these studies are published in NASA technical papers and reference publication as well as in technical society journal articles. The results of the work of the Structures Division and the bibliography of its publications for calendar year 1995 are presented.

Structures Division 1994 Annual Report

NASA Technical Reports Server (NTRS)

1996-01-01

The NASA Lewis Research Center Structures Division is an international leader and pioneer in developing new structural analysis, life prediction, and failure analysis related to rotating machinery and more specifically to hot section components in air-breathing aircraft engines and spacecraft propulsion systems. The research consists of both deterministic and probabilistic methodology. Studies include, but are not limited to, high-cycle and low-cycle fatigue as well as material creep. Studies of structural failure are at both the micro- and macrolevels. Nondestructive evaluation methods related to structural reliability are developed, applied, and evaluated. Materials from which structural components are made, studied, and tested are monolithics and metal-matrix, polymer-matrix, and ceramic-matrix composites. Aeroelastic models are developed and used to determine the cyclic loading and life of fan and turbine blades. Life models are developed and tested for bearings, seals, and other mechanical components, such as magnetic suspensions. Results of these studies are published in NASA technical papers and reference publication as well as in technical society journal articles. The results of the work of the Structures Division and the bibliography of its publications for calendar year 1994 are presented.

Comparative proteomic analysis of normal and collagen IX null mouse cartilage reveals altered extracellular matrix composition and novel components of the collagen IX interactome.

PubMed

Brachvogel, Bent; Zaucke, Frank; Dave, Keyur; Norris, Emma L; Stermann, Jacek; Dayakli, Münire; Koch, Manuel; Gorman, Jeffrey J; Bateman, John F; Wilson, Richard

2013-05-10

Collagen IX is an integral cartilage extracellular matrix component important in skeletal development and joint function. Proteomic analysis and validation studies revealed novel alterations in collagen IX null cartilage. Matrilin-4, collagen XII, thrombospondin-4, fibronectin, βig-h3, and epiphycan are components of the in vivo collagen IX interactome. We applied a proteomics approach to advance our understanding of collagen IX ablation in cartilage. The cartilage extracellular matrix is essential for endochondral bone development and joint function. In addition to the major aggrecan/collagen II framework, the interacting complex of collagen IX, matrilin-3, and cartilage oligomeric matrix protein (COMP) is essential for cartilage matrix stability, as mutations in Col9a1, Col9a2, Col9a3, Comp, and Matn3 genes cause multiple epiphyseal dysplasia, in which patients develop early onset osteoarthritis. In mice, collagen IX ablation results in severely disturbed growth plate organization, hypocellular regions, and abnormal chondrocyte shape. This abnormal differentiation is likely to involve altered cell-matrix interactions but the mechanism is not known. To investigate the molecular basis of the collagen IX null phenotype we analyzed global differences in protein abundance between wild-type and knock-out femoral head cartilage by capillary HPLC tandem mass spectrometry. We identified 297 proteins in 3-day cartilage and 397 proteins in 21-day cartilage. Components that were differentially abundant between wild-type and collagen IX-deficient cartilage included 15 extracellular matrix proteins. Collagen IX ablation was associated with dramatically reduced COMP and matrilin-3, consistent with known interactions. Matrilin-1, matrilin-4, epiphycan, and thrombospondin-4 levels were reduced in collagen IX null cartilage, providing the first in vivo evidence for these proteins belonging to the collagen IX interactome. Thrombospondin-4 expression was reduced at the mRNA level, whereas matrilin-4 was verified as a novel collagen IX-binding protein. Furthermore, changes in TGFβ-induced protein βig-h3 and fibronectin abundance were found in the collagen IX knock-out but not associated with COMP ablation, indicating specific involvement in the abnormal collagen IX null cartilage. In addition, the more widespread expression of collagen XII in the collagen IX-deficient cartilage suggests an attempted compensatory response to the absence of collagen IX. Our differential proteomic analysis of cartilage is a novel approach to identify candidate matrix protein interactions in vivo, underpinning further analysis of mutant cartilage lacking other matrix components or harboring disease-causing mutations.

KinD is a checkpoint protein linking spore formation to extracellular-matrix production in Bacillus subtilis biofilms.

PubMed

Aguilar, Claudio; Vlamakis, Hera; Guzman, Alejandra; Losick, Richard; Kolter, Roberto

2010-05-18

Bacillus subtilis cells form multicellular biofilm communities in which spatiotemporal regulation of gene expression occurs, leading to differentiation of multiple coexisting cell types. These cell types include matrix-producing and sporulating cells. Extracellular matrix production and sporulation are linked in that a mutant unable to produce matrix is delayed for sporulation. Here, we show that the delay in sporulation is not due to a growth advantage of the matrix-deficient mutant under these conditions. Instead, we show that the link between matrix production and sporulation is through the Spo0A signaling pathway. Both processes are regulated by the phosphorylated form of the master transcriptional regulator Spo0A. When cells have low levels of phosphorylated Spo0A (Spo0A~P), matrix genes are expressed; however, at higher levels of Spo0A~P, sporulation commences. We have found that Spo0A~P levels are maintained at low levels in the matrix-deficient mutant, thereby delaying expression of sporulation-specific genes. This is due to the activity of one of the components of the Spo0A phosphotransfer network, KinD. A deletion of kinD suppresses the sporulation defect of matrix mutants, while its overproduction delays sporulation. Our data indicate that KinD displays a dual role as a phosphatase or a kinase and that its activity is linked to the presence of extracellular matrix in the biofilms. We propose a novel role for KinD in biofilms as a checkpoint protein that regulates the onset of sporulation by inhibiting the activity of Spo0A until matrix, or a component therein, is sensed.

KinD Is a Checkpoint Protein Linking Spore Formation to Extracellular-Matrix Production in Bacillus subtilis Biofilms

PubMed Central

Aguilar, Claudio; Vlamakis, Hera; Guzman, Alejandra; Losick, Richard; Kolter, Roberto

2010-01-01

ABSTRACT Bacillus subtilis cells form multicellular biofilm communities in which spatiotemporal regulation of gene expression occurs, leading to differentiation of multiple coexisting cell types. These cell types include matrix-producing and sporulating cells. Extracellular matrix production and sporulation are linked in that a mutant unable to produce matrix is delayed for sporulation. Here, we show that the delay in sporulation is not due to a growth advantage of the matrix-deficient mutant under these conditions. Instead, we show that the link between matrix production and sporulation is through the Spo0A signaling pathway. Both processes are regulated by the phosphorylated form of the master transcriptional regulator Spo0A. When cells have low levels of phosphorylated Spo0A (Spo0A~P), matrix genes are expressed; however, at higher levels of Spo0A~P, sporulation commences. We have found that Spo0A~P levels are maintained at low levels in the matrix-deficient mutant, thereby delaying expression of sporulation-specific genes. This is due to the activity of one of the components of the Spo0A phosphotransfer network, KinD. A deletion of kinD suppresses the sporulation defect of matrix mutants, while its overproduction delays sporulation. Our data indicate that KinD displays a dual role as a phosphatase or a kinase and that its activity is linked to the presence of extracellular matrix in the biofilms. We propose a novel role for KinD in biofilms as a checkpoint protein that regulates the onset of sporulation by inhibiting the activity of Spo0A until matrix, or a component therein, is sensed. PMID:20689749

Carbon-carbon primary structure for SSTO vehicles

NASA Astrophysics Data System (ADS)

Croop, Harold C.; Lowndes, Holland B.

1997-01-01

A hot structures development program is nearing completion to validate use of carbon-carbon composite structure for primary load carrying members in a single-stage-to-orbit, or SSTO, vehicle. A four phase program was pursued which involved design development and fabrication of a full-scale wing torque box demonstration component. The design development included vehicle and component selection, design criteria and approach, design data development, demonstration component design and analysis, test fixture design and analysis, demonstration component test planning, and high temperature test instrumentation development. The fabrication effort encompassed fabrication of structural elements for mechanical property verification as well as fabrication of the demonstration component itself and associated test fixturing. The demonstration component features 3D woven graphite preforms, integral spars, oxidation inhibited matrix, chemical vapor deposited (CVD) SiC oxidation protection coating, and ceramic matrix composite fasteners. The demonstration component has been delivered to the United States Air Force (USAF) for testing in the Wright Laboratory Structural Test Facility, WPAFB, OH. Multiple thermal-mechanical load cycles will be applied simulating two atmospheric cruise missions and one orbital mission. This paper discusses the overall approach to validation testing of the wing box component and presents some preliminary analytical test predictions.

Ion processing element with composite media

DOEpatents

Mann, Nick R.; Tranter, Troy J.; Todd, Terry A.; Sebesta, Ferdinand

2003-02-04

An ion processing element employing composite media disposed in a porous substrate, for facilitating removal of selected chemical species from a fluid stream. The ion processing element includes a porous fibrous glass substrate impregnated by composite media having one or more active components supported by a matrix material of polyacrylonitrile. The active components are effective in removing, by various mechanisms, one or more constituents from a fluid stream passing through the ion processing element. Due to the porosity and large surface area of both the composite medium and the substrate in which it is disposed, a high degree of contact is achieved between the active component and the fluid stream being processed. Further, the porosity of the matrix material and the substrate facilitates use of the ion processing element in high volume applications where it is desired to effectively process a high volume flows.

Ion processing element with composite media

DOEpatents

Mann, Nick R [Blackfoot, ID; Tranter, Troy J [Idaho Falls, ID; Todd, Terry A [Aberdeen, ID; Sebesta, Ferdinand [Prague, CZ

2009-03-24

An ion processing element employing composite media disposed in a porous substrate, for facilitating removal of selected chemical species from a fluid stream. The ion processing element includes a porous fibrous glass substrate impregnated by composite media having one or more active components supported by a matrix material of polyacrylonitrile. The active components are effective in removing, by various mechanisms, one or more constituents from a fluid stream passing through the ion processing element. Due to the porosity and large surface area of both the composite medium and the substrate in which it is disposed, a high degree of contact is achieved between the active component and the fluid stream being processed. Further, the porosity of the matrix material and the substrate facilitates use of the ion processing element in high volume applications where it is desired to effectively process a high volume flows.

Laminated Object Manufacturing-Based Design Ceramic Matrix Composites

DTIC Science & Technology

2001-04-01

components for DoD applications. Program goals included the development of (1) a new LOM based design methodology for CMC, (2) optimized preceramic polymer ...3.1.1-20 3.1.1-12 Detail of LOM Composites Forming System w/ glass fiber/ polymer laminate................ 3.1.1-21 3.1.1-13...such as polymer matrix composites have faced similar barriers to implementation. These barriers have been overcome through the development of suitable

Reliability and life prediction of ceramic composite structures at elevated temperatures

NASA Technical Reports Server (NTRS)

Duffy, Stephen F.; Gyekenyesi, John P.

1994-01-01

Methods are highlighted that ascertain the structural reliability of components fabricated of composites with ceramic matrices reinforced with ceramic fibers or whiskers and subject to quasi-static load conditions at elevated temperatures. Each method focuses on a particular composite microstructure: whisker-toughened ceramics, laminated ceramic matrix composites, and fabric reinforced ceramic matrix composites. In addition, since elevated service temperatures usually involve time-dependent effects, a section dealing with reliability degradation as a function of load history has been included. A recurring theme throughout this chapter is that even though component failure is controlled by a sequence of many microfailure events, failure of ceramic composites will be modeled using macrovariables.

Matrix approach to uncertainty assessment and reduction for modeling terrestrial carbon cycle

NASA Astrophysics Data System (ADS)

Luo, Y.; Xia, J.; Ahlström, A.; Zhou, S.; Huang, Y.; Shi, Z.; Wang, Y.; Du, Z.; Lu, X.

2017-12-01

Terrestrial ecosystems absorb approximately 30% of the anthropogenic carbon dioxide emissions. This estimate has been deduced indirectly: combining analyses of atmospheric carbon dioxide concentrations with ocean observations to infer the net terrestrial carbon flux. In contrast, when knowledge about the terrestrial carbon cycle is integrated into different terrestrial carbon models they make widely different predictions. To improve the terrestrial carbon models, we have recently developed a matrix approach to uncertainty assessment and reduction. Specifically, the terrestrial carbon cycle has been commonly represented by a series of carbon balance equations to track carbon influxes into and effluxes out of individual pools in earth system models. This representation matches our understanding of carbon cycle processes well and can be reorganized into one matrix equation without changing any modeled carbon cycle processes and mechanisms. We have developed matrix equations of several global land C cycle models, including CLM3.5, 4.0 and 4.5, CABLE, LPJ-GUESS, and ORCHIDEE. Indeed, the matrix equation is generic and can be applied to other land carbon models. This matrix approach offers a suite of new diagnostic tools, such as the 3-dimensional (3-D) parameter space, traceability analysis, and variance decomposition, for uncertainty analysis. For example, predictions of carbon dynamics with complex land models can be placed in a 3-D parameter space (carbon input, residence time, and storage potential) as a common metric to measure how much model predictions are different. The latter can be traced to its source components by decomposing model predictions to a hierarchy of traceable components. Then, variance decomposition can help attribute the spread in predictions among multiple models to precisely identify sources of uncertainty. The highly uncertain components can be constrained by data as the matrix equation makes data assimilation computationally possible. We will illustrate various applications of this matrix approach to uncertainty assessment and reduction for terrestrial carbon cycle models.

Further Developments in Modeling Creep Effects Within Structural SiC/SiC Components

NASA Technical Reports Server (NTRS)

Lang, Jerry; DiCarlo, James A.

2008-01-01

Anticipating the implementation of advanced SiC/SiC composites into turbine section components of future aero-propulsion engines, the primary objective of this on-going study is to develop physics-based analytical and finite-element modeling tools to predict the effects of constituent creep on SiC/SiC component service life. A second objective is to understand how to possibly manipulate constituent materials and processes in order to minimize these effects. Focusing on SiC/SiC components experiencing through-thickness stress gradients (e.g., airfoil leading edge), prior NASA creep modeling studies showed that detrimental residual stress effects can develop globally within the component walls which can increase the risk of matrix cracking. These studies assumed that the SiC/SiC composites behaved as isotropic viscoelastic continuum materials with creep behavior that was linear and symmetric with stress and that the creep parameters could be obtained from creep data as experimentally measured in-plane in the fiber direction of advanced thin-walled 2D SiC/SiC panels. The present study expands on those prior efforts by including constituent behavior with non-linear stress dependencies in order to predict such key creep-related SiC/SiC properties as time-dependent matrix stress, constituent creep and content effects on composite creep rates and rupture times, and stresses on fiber and matrix during and after creep.

Release from or through a wax matrix system. IV. Generalized expression of the release process for a reservoir device tablet.

PubMed

Yonezawa, Yorinobu; Ishida, Sumio; Suzuki, Shinobu; Sunada, Hisakazu

2002-09-01

Generalization of the release process through the wax matrix layer was examined by use of a reservoir device tablet. The wax matrix layer of the reservoir device tablet was prepared from a physical mixture of lactose and hydrogenated castor oil to simplify the release properties. Release through the wax matrix layer showed zero-order kinetics in a steady state after a given lag time, and could be divided into two stages. The first stage was the formation process of water channel by dissolving the soluble component in the wax matrix layer. The lag time obtained by applying the square root law equation was well connected with the amount of the matrix layer and mixed weight ratio of components in this layer. The second stage was the zero-order release process of drug in the reservoir through the wax matrix layer, because the effective surface area was fixed. The release rate constants were connected with thickness of the matrix layer and permeability coefficient, and the permeability coefficients were connected with the diffusion coefficient of drug and porosity. Hence the release rate constant could be connected with the amount of matrix layer and the mixed weight ratio of components in the matrix layer. It was therefore suggested that the release process could be generalized using the amount of matrix layer and the mixed weight ratio of components in the matrix layer.

Visualization of extracellular matrix components within sectioned Salmonella biofilms on the surface of human gallstones.

PubMed

Marshall, Joanna M; Flechtner, Alan D; La Perle, Krista M; Gunn, John S

2014-01-01

Chronic carriage of Salmonella Typhi is mediated primarily through the formation of bacterial biofilms on the surface of cholesterol gallstones. Biofilms, by definition, involve the formation of a bacterial community encased within a protective macromolecular matrix. Previous work has demonstrated the composition of the biofilm matrix to be complex and highly variable in response to altered environmental conditions. Although known to play an important role in bacterial persistence in a variety of contexts, the Salmonella biofilm matrix remains largely uncharacterized under physiological conditions. Initial attempts to study matrix components and architecture of the biofilm matrix on gallstone surfaces were hindered by the auto-fluorescence of cholesterol. In this work we describe a method for sectioning and direct visualization of extracellular matrix components of the Salmonella biofilm on the surface of human cholesterol gallstones and provide a description of the major matrix components observed therein. Confocal micrographs revealed robust biofilm formation, characterized by abundant but highly heterogeneous expression of polysaccharides such as LPS, Vi and O-antigen capsule. CsgA was not observed in the biofilm matrix and flagellar expression was tightly restricted to the biofilm-cholesterol interface. Images also revealed the presence of preexisting Enterobacteriaceae encased within the structure of the gallstone. These results demonstrate the use and feasibility of this method while highlighting the importance of studying the native architecture of the gallstone biofilm. A better understanding of the contribution of individual matrix components to the overall biofilm structure will facilitate the development of more effective and specific methods to disrupt these bacterial communities.

Methods for providing ceramic matrix composite components with increased thermal capacity

NASA Technical Reports Server (NTRS)

Steibel, James Dale (Inventor); Utah, David Alan (Inventor)

2001-01-01

A method for enhancing the cooling capability of a turbine component made from a ceramic matrix composite. The method improves the thermal performance of the component by producing a surface having increased cooling capacity, thereby allowing the component to operate at a higher temperature. The method tailors the available surface area on the cooling surface of the composite component by depositing a particulate layer of coarse grained ceramic powders of preselected size onto the surface of the ceramic matrix composite component. The size of the particulate is selectively tailored to match the desired surface finish or surface roughness of the article. The article may be designed to have different surface finishes for different locations, so that the application of different sized powders can provide different cooling capabilities at different locations, if desired. The compositions of the particulates are chemically compatible with the ceramic material comprising the outer surface or portion of the ceramic matrix composite. The particulates are applied using a slurry and incorporated into the article by heating to an elevated temperature without melting the matrix, the particulates or the fiber reinforcement.

Crosstalk compensation in analysis of energy storage devices

DOEpatents

Christophersen, Jon P; Morrison, John L; Morrison, William H; Motloch, Chester G; Rose, David M

2014-06-24

Estimating impedance of energy storage devices includes generating input signals at various frequencies with a frequency step factor therebetween. An excitation time record (ETR) is generated to include a summation of the input signals and a deviation matrix of coefficients is generated relative to the excitation time record to determine crosstalk between the input signals. An energy storage device is stimulated with the ETR and simultaneously a response time record (RTR) is captured that is indicative of a response of the energy storage device to the ETR. The deviation matrix is applied to the RTR to determine an in-phase component and a quadrature component of an impedance of the energy storage device at each of the different frequencies with the crosstalk between the input signals substantially removed. This approach enables rapid impedance spectra measurements that can be completed within one period of the lowest frequency or less.

Environmental Barrier Coatings for Ceramic Matrix Composites - An Overview

NASA Technical Reports Server (NTRS)

Lee, Kang; van Roode, Mark; Kashyap, Tania; Zhu, Dongming; Wiesner, Valerie

2017-01-01

SiC/SiC Ceramic Matrix Composites (CMCs) are increasingly being considered as structural materials for advanced power generation equipment because of their light weight, higher temperature capability, and oxidation resistance. Limitations of SiC/SiC CMCs include surface recession and component cracking and associated chemical changes in the CMC. The solutions pursued to improve the life of SiC/SiC CMCs include the incorporation of coating systems that provide surface protection, which has become known as an Environmental Barrier Coating (EBC). The development of EBCs for the protection of gas turbine hot section CMC components was a continuation of coating development work for corrosion protection of silicon-based monolithics. Work on EBC development for SiC/SiC CMCs has been ongoing at several national laboratories and the original gas turbine equipment manufacturers. The work includes extensive laboratory, rig and engine testing, including testing of EBC coated SiC/SiC CMCs in actual field applications. Another EBC degradation issue which is especially critical for CMC components used in aircraft engines is the degradation from glassy deposits of calcium-magnesium-aluminosilicate (CMAS) with other minor oxides. This paper addresses the need for and properties of external coatings on SiC/SiC CMCs to extend their useful life in service and the retention of their properties.

Determining the Number of Components from the Matrix of Partial Correlations

ERIC Educational Resources Information Center

Velicer, Wayne F.

1976-01-01

A method is presented for determining the number of components to retain in a principal components or image components analysis which utilizes a matrix of partial correlations. Advantages and uses of the method are discussed and a comparison of the proposed method with existing methods is presented. (JKS)

Using Separable Nonnegative Matrix Factorization Techniques for the Analysis of Time-Resolved Raman Spectra

NASA Astrophysics Data System (ADS)

Luce, R.; Hildebrandt, P.; Kuhlmann, U.; Liesen, J.

2016-09-01

The key challenge of time-resolved Raman spectroscopy is the identification of the constituent species and the analysis of the kinetics of the underlying reaction network. In this work we present an integral approach that allows for determining both the component spectra and the rate constants simultaneously from a series of vibrational spectra. It is based on an algorithm for non-negative matrix factorization which is applied to the experimental data set following a few pre-processing steps. As a prerequisite for physically unambiguous solutions, each component spectrum must include one vibrational band that does not significantly interfere with vibrational bands of other species. The approach is applied to synthetic "experimental" spectra derived from model systems comprising a set of species with component spectra differing with respect to their degree of spectral interferences and signal-to-noise ratios. In each case, the species involved are connected via monomolecular reaction pathways. The potential and limitations of the approach for recovering the respective rate constants and component spectra are discussed.

Metal-Matrix Composite Parts With Metal Inserts

NASA Technical Reports Server (NTRS)

Majkowski, T.; Kashalikar, U.

1995-01-01

Developmental fabrication process produces metal-matrix composite (MMC) parts with integral metal inserts. With inserts, MMC parts readily joined to similar parts by use of brazing, welding, or mechanical fasteners. Process conceived to make strong, lightweight components of structures erected in outer space. Also useful on Earth, in such automotive parts as rocker arms, cylinder liners, and pistons. Potential industrial applications include parts subjected to high stresses at high temperatures, as in power-generation, mining, and oil-drilling equipment.

What is the difference in organic matrix of aragonite vs. vaterite polymorph in natural shell and pearl? Study of the pearl-forming freshwater bivalve mollusc Hyriopsis cumingii.

PubMed

Ma, Yufei; Berland, Sophie; Andrieu, Jean-Pierre; Feng, Qingling; Bédouet, Laurent

2013-04-01

Aragonite pearl, vaterite pearl and shell nacre of the freshwater mollusc Hyriopsis cumingii (Zhejiang province, China) were chosen to analyze microstructure and organic composition in the different habits of calcium carbonate. SEM and TEM were used to reveal the microstructure and mineralogical phase. We found that tablets in vaterite exhibited more irregular texture and were packaged with more organic matrices than in aragonite forms. Then a peculiar method was introduced to extract water soluble matrix (WSM), acid soluble matrix (ASM) and acid insoluble matrix (AIM) from the three samples, and biochemical analysis of these organic matrixes involved in crystal formation and polymorph selection was carried out. High performance liquid chromatography (HPLC) confirms the hydrophobic pattern of the organic matrix intermingled with mineral, the opposite of the early mobilizable water soluble fraction. Amino acid composition confirms hydrophobic residues as major components of all the extracts, but it reveals an imbalance in acidic residues rates in WSM vs. ASM and in aragonite vs. vaterite. Electrophoresis gives evidence for signatures in proteins with a 140 kDa material specific for aragonite in WSM. Conversely all ASM extracts reveal the presence of about 55 kDa components, including a discrete band in vaterite extract. Copyright © 2012 Elsevier B.V. All rights reserved.

Two-component quantum Hall effects in topological flat bands

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

Zeng, Tian-Sheng; Zhu, Wei; Sheng, D. N.

2017-03-27

Here in this paper, we study quantum Hall states for two-component particles (hardcore bosons and fermions) loading in topological lattice models. By tuning the interplay of interspecies and intraspecies interactions, we demonstrate that two-component fractional quantum Hall states emerge at certain fractional filling factors ν = 1/2 for fermions (ν = 2/3 for bosons) in the lowest Chern band, classified by features from ground states including the unique Chern number matrix (inverse of the K matrix), the fractional charge and spin pumpings, and two parallel propagating edge modes. Moreover, we also apply our strategy to two-component fermions at integer fillingmore » factor ν = 2 , where a possible topological Neel antiferromagnetic phase is under intense debate very recently. For the typical π -flux checkerboard lattice, by tuning the onsite Hubbard repulsion, we establish a first-order phase transition directly from a two-component fermionic ν = 2 quantum Hall state at weak interaction to a topologically trivial antiferromagnetic insulator at strong interaction, and therefore exclude the possibility of an intermediate topological phase for our system.« less

Robust Joining and Integration Technologies for Advanced Metallic, Ceramic, and Composite Systems

NASA Technical Reports Server (NTRS)

Singh, M.; Shpargel, Tarah; Morscher, Gregory N.; Halbig, Michael H.; Asthana, Rajiv

2006-01-01

Robust integration and assembly technologies are critical for the successful implementation of advanced metallic, ceramic, carbon-carbon, and ceramic matrix composite components in a wide variety of aerospace, space exploration, and ground based systems. Typically, the operating temperature of these components varies from few hundred to few thousand Kelvin with different working times (few minutes to years). The wide ranging system performance requirements necessitate the use of different integration technologies which includes adhesive bonding, low temperature soldering, active metal brazing, diffusion bonding, ARCJoinT, and ultra high temperature joining technologies. In this presentation, a number of joining examples and test results will be provided related to the adhesive bonding and active metal brazing of titanium to C/C composites, diffusion bonding of silicon carbide to silicon carbide using titanium interlayer, titanium and hastelloy brazing to silicon carbide matrix composites, and ARCJoinT joining of SiC ceramics and SiC matrix composites. Various issues in the joining of metal-ceramic systems including thermal expansion mismatch and resulting residual stresses generated during joining will be discussed. In addition, joint design and testing issues for a wide variety of joints will be presented.

Matrix and fine-grained rims in the unequilibrated CO3 chondrite, ALHA77307 - Origins and evidence for diverse, primitive nebular dust components

NASA Technical Reports Server (NTRS)

Brearley, Adrian J.

1993-01-01

SEM, TEM, and electron microprobe analysis were used to investigate in detail the mineralogical and chemical characteristics of dark matrix and fine-grained rims in the unequilibrated CO3 chondrite ALHA77307. Data obtained revealed that there was a remarkable diversity of distinct mineralogical components, which can be identified using their chemical and textural characteristics. The matrix and rim components in ALHA77307 formed by disequilibrium condensation process as fine-grained amorphous dust that is represented by the abundant amorphous component in the matrix. Subsequent thermal processing of this condensate material, in a variety of environments in the nebula, caused partial or complete recrystallization of the fine-grained dust.

Pattern identification in time-course gene expression data with the CoGAPS matrix factorization.

PubMed

Fertig, Elana J; Stein-O'Brien, Genevieve; Jaffe, Andrew; Colantuoni, Carlo

2014-01-01

Patterns in time-course gene expression data can represent the biological processes that are active over the measured time period. However, the orthogonality constraint in standard pattern-finding algorithms, including notably principal components analysis (PCA), confounds expression changes resulting from simultaneous, non-orthogonal biological processes. Previously, we have shown that Markov chain Monte Carlo nonnegative matrix factorization algorithms are particularly adept at distinguishing such concurrent patterns. One such matrix factorization is implemented in the software package CoGAPS. We describe the application of this software and several technical considerations for identification of age-related patterns in a public, prefrontal cortex gene expression dataset.

Ceramic Matrix Composite (CMC) Materials Development

NASA Technical Reports Server (NTRS)

DiCarlo, James

2001-01-01

Under the former NASA EPM Program, much initial progress was made in identifying constituent materials and processes for SiC/SiC ceramic composite hot-section components. This presentation discusses the performance benefits of these approaches and elaborates on further constituent and property improvements made under NASA UEET. These include specific treatments at NASA that significantly improve the creep and environmental resistance of the Sylramic(TM) Sic fiber as well as the thermal conductivity and creep resistance of the CVI Sic matrix. Also discussed are recent findings concerning the beneficial effects of certain 2D-fabric architectures and carbon between the BN interphase coating and Sic matrix.

Ceramic Matrix Composite (CMC) Materials Characterization

NASA Technical Reports Server (NTRS)

Calomino, Anthony

2001-01-01

Under the former NASA EPM Program, much initial progress was made in identifying constituent materials and processes for SiC/SiC ceramic composite hot-section components. This presentation discusses the performance benefits of these approaches and elaborates on further constituent and property improvements made under NASA UEET. These include specific treatments at NASA that significantly improve the creep and environmental resistance of the Sylramic(TM) SiC fiber as well as the thermal conductivity and creep resistance of the CVI Sic matrix. Also discussed are recent findings concerning the beneficial effects of certain 2D-fabric architectures and carbon between the BN interphase coating and Sic matrix.

The SBIRT program matrix: a conceptual framework for program implementation and evaluation.

PubMed

Del Boca, Frances K; McRee, Bonnie; Vendetti, Janice; Damon, Donna

2017-02-01

Screening, Brief Intervention and Referral to Treatment (SBIRT) is a comprehensive, integrated, public health approach to the delivery of services to those at risk for the adverse consequences of alcohol and other drug use, and for those with probable substance use disorders. Research on successful SBIRT implementation has lagged behind studies of efficacy and effectiveness. This paper (1) outlines a conceptual framework, the SBIRT Program Matrix, to guide implementation research and program evaluation and (2) specifies potential implementation outcomes. Overview and narrative description of the SBIRT Program Matrix. The SBIRT Program Matrix has five components, each of which includes multiple elements: SBIRT services; performance sites; provider attributes; patient/client populations; and management structure and activities. Implementation outcomes include program adoption, acceptability, appropriateness, feasibility, fidelity, costs, penetration, sustainability, service provision and grant compliance. The Screening, Brief Intervention and Referral to Treatment Program Matrix provides a template for identifying, classifying and organizing the naturally occurring commonalities and variations within and across SBIRT programs, and for investigating which variables are associated with implementation success and, ultimately, with treatment outcomes and other impacts. © 2017 Society for the Study of Addiction.

Insight into the heterogeneous adsorption of humic acid fluorescent components on multi-walled carbon nanotubes by excitation-emission matrix and parallel factor analysis.

PubMed

Yang, Chenghu; Liu, Yangzhi; Cen, Qiulin; Zhu, Yaxian; Zhang, Yong

2018-02-01

The heterogeneous adsorption behavior of commercial humic acid (HA) on pristine and functionalized multi-walled carbon nanotubes (MWCNTs) was investigated by fluorescence excitation-emission matrix and parallel factor (EEM- PARAFAC) analysis. The kinetics, isotherms, thermodynamics and mechanisms of adsorption of HA fluorescent components onto MWCNTs were the focus of the present study. Three humic-like fluorescent components were distinguished, including one carboxylic-like fluorophore C1 (λ ex /λ em = (250, 310) nm/428nm), and two phenolic-like fluorophores, C2 (λ ex /λ em = (300, 460) nm/552nm) and C3 (λ ex /λ em = (270, 375) nm/520nm). The Lagergren pseudo-second-order model can be used to describe the adsorption kinetics of the HA fluorescent components. In addition, both the Freundlich and Langmuir models can be suitably employed to describe the adsorption of the HA fluorescent components onto MWCNTs with significantly high correlation coefficients (R 2 > 0.94, P< 0.05). The dissimilarity in the adsorption affinity (K d ) and nonlinear adsorption degree from the HA fluorescent components to MWCNTs was clearly observed. The adsorption mechanism suggested that the π-π electron donor-acceptor (EDA) interaction played an important role in the interaction between HA fluorescent components and the three MWCNTs. Furthermore, the values of the thermodynamic parameters, including the Gibbs free energy change (ΔG°), enthalpy change (ΔH°) and entropy change (ΔS°), showed that the adsorption of the HA fluorescent components on MWCNTs was spontaneous and exothermic. Copyright © 2017 Elsevier Inc. All rights reserved.

Cell and matrix modulation in prenatal and postnatal equine growth cartilage, zones of Ranvier and articular cartilage

PubMed Central

Löfgren, Maria; Ekman, Stina; Svala, Emilia; Lindahl, Anders; Ley, Cecilia; Skiöldebrand, Eva

2014-01-01

Formation of synovial joints includes phenotypic changes of the chondrocytes and the organisation of their extracellular matrix is regulated by different factors and signalling pathways. Increased knowledge of the normal processes involved in joint development may be used to identify similar regulatory mechanisms during pathological conditions in the joint. Samples of the distal radius were collected from prenatal and postnatal equine growth plates, zones of Ranvier and articular cartilage with the aim of identifying Notch signalling components and cells with stem cell-like characteristics and to follow changes in matrix protein localisation during joint development. The localisation of the Notch signalling components Notch1, Delta4, Hes1, Notch dysregulating protein epidermal growth factor-like domain 7 (EGFL7), the stem cell-indicating factor Stro-1 and the matrix molecules cartilage oligomeric matrix protein (COMP), fibromodulin, matrilin-1 and chondroadherin were studied using immunohistochemistry. Spatial changes in protein localisations during cartilage maturation were observed for Notch signalling components and matrix molecules, with increased pericellular localisation indicating new synthesis and involvement of these proteins in the formation of the joint. However, it was not possible to characterise the phenotype of the chondrocytes based on their surrounding matrix during normal chondrogenesis. The zone of Ranvier was identified in all horses and characterised as an area expressing Stro-1, EGFL7 and chondroadherin with an absence of COMP and Notch signalling. Stro-1 was also present in cells close to the perichondrium, in the articular cartilage and in the fetal resting zone, indicating stem cell-like characteristics of these cells. The presence of stem cells in the articular cartilage will be of importance for the repair of damaged cartilage. Perivascular chondrocytes and hypertrophic cells of the cartilage bone interface displayed positive staining for EGFL7, which is a novel finding and suggests a role of EGFL7 in the vascular infiltration of growth cartilage. PMID:25175365

Chondrogenic properties of collagen type XI, a component of cartilage extracellular matrix.

PubMed

Li, Ang; Wei, Yiyong; Hung, Clark; Vunjak-Novakovic, Gordana

2018-08-01

Cartilage extracellular matrix (ECM) has been used for promoting tissue engineering. However, the exact effects of ECM on chondrogenesis and the acting mechanisms are not well understood. In this study, we investigated the chondrogenic effects of cartilage ECM on human mesenchymal stem cells (MSCs) and identified the contributing molecular components. To this end, a preparation of articular cartilage ECM was supplemented to pellets of chondrogenically differentiating MSCs, pellets of human chondrocytes, and bovine articular cartilage explants to evaluate the effects on cell proliferation and the production of cartilaginous matrix. Selective enzymatic digestion and screening of ECM components were conducted to identify matrix molecules with chondrogenic properties. Cartilage ECM promoted MSC proliferation, production of cartilaginous matrix, and maturity of chondrogenic differentiation, and inhibited the hypertrophic differentiation of MSC-derived chondrocytes. Selective digestion of ECM components revealed a contributory role of collagens in promoting chondrogenesis. The screening of various collagen subtypes revealed strong chondrogenic effect of collagen type XI. Finally, collagen XI was found to promote production and inhibit degradation of cartilage matrix in human articular chondrocyte pellets and bovine articular cartilage explants. Our results indicate that cartilage ECM promotes chondrogenesis and inhibits hypertrophic differentiation in MSCs. Collagen type XI is the ECM component that has the strongest effects on enhancing the production and inhibiting the degradation of cartilage matrix. Copyright © 2018 Elsevier Ltd. All rights reserved.

Kinetic Monte Carlo Simulations of Oxygen Diffusion in Environmental Barrier Coating Materials

NASA Technical Reports Server (NTRS)

Good, Brian S.

2017-01-01

Ceramic Matrix Composite (CMC) materials are of interest for use in next-generation turbine engine components, offering a number of significant advantages, including reduced weight and high operating temperatures. However, in the hot environment in which such components operate, the presence of water vapor can lead to corrosion and recession, limiting the useful life of the components. Such degradation can be reduced through the use of Environmental Barrier Coatings (EBCs) that limit the amount of oxygen and water vapor reaching the component. Candidate EBC materials include Yttrium and Ytterbium silicates. In this work we present results of kinetic Monte Carlo (kMC) simulations of oxygen diffusion, via the vacancy mechanism, in Yttrium and Ytterbium disilicates, along with a brief discussion of interstitial diffusion.

Free Volume Structure of Acrylic-Type Dental Nanocomposites Tested with Annihilating Positrons.

PubMed

Shpotyuk, Olha; Ingram, Adam; Shpotyuk, Oleh

2016-12-01

Positron annihilation spectroscopy in lifetime measuring mode exploring conventional fast-fast coincidence ORTEC system is employed to characterize free volume structure of commercially available acrylic-type dental restorative composite Charisma® (Heraeus Kulzer GmbH, Germany). The measured lifetime spectra for uncured and light-cured composites are reconstructed from unconstrained x3-term fitting and semi-empirical model exploring x3-x2-coupling decomposition algorithm. The governing channel of positron annihilation in the composites studied is ascribed to mixed positron-Ps trapping, where Ps decaying in the third component is caused entirely by input from free-volume holes in polymer matrix, while the second component is defined by free positron trapping in interfacial free-volume holes between filler nanoparticles and surrounded polymer matrix. Microstructure scenario of the photopolymerization shrinkage includes cross-linking of structural chains in polymer matrix followed by conversion of bound positron-electron (positronium) traps in positron-trapping interfacial free-volume voids in a vicinity of agglomerated filler nanoparticles.

Comments on: Christensen, N., and Lawrie, K., 2012. Resolution analyses for selecting an appropriate airborne electromagnetic (AEM) system, Exploration Geophysics, 43, 213-227

NASA Astrophysics Data System (ADS)

Smiarowski, Adam; Mulè, Shane

2015-06-01

The AEM in-line component is added to the posterior model covariance matrix analysis done by Christensen and Lawrie, who estimated resolution of data in an inversion program. They compared two AEM systems: SkyTEM and CGG's TEMPEST™. Here, we clarify points made about TEMPEST™ and extend the analysis to include the in-line component.

Matrix metalloproteinases in kidney homeostasis and diseases

PubMed Central

Tan, Roderick J.

2012-01-01

Matrix metalloproteinases (MMPs) are a family of zinc-dependent endopeptidases that have been increasingly linked to both normal physiology and abnormal pathology in the kidney. Collectively able to degrade all components of the extracellular matrix, MMPs were originally thought to antagonize the development of fibrotic diseases solely through digestion of excessive matrix. However, increasing evidence has shown that MMPs play a wide variety of roles in regulating inflammation, epithelial-mesenchymal transition, cell proliferation, angiogenesis, and apoptosis. We now have robust evidence for MMP dysregulation in a multitude of renal diseases including acute kidney injury, diabetic nephropathy, glomerulonephritis, inherited kidney disease, and chronic allograft nephropathy. The goal of this review is to summarize current findings regarding the role of MMPs in kidney diseases as well as the mechanisms of action of this family of proteases. PMID:22492945

Processing of Antenna-Array Signals on the Basis of the Interference Model Including a Rank-Deficient Correlation Matrix

NASA Astrophysics Data System (ADS)

Rodionov, A. A.; Turchin, V. I.

2017-06-01

We propose a new method of signal processing in antenna arrays, which is called the Maximum-Likelihood Signal Classification. The proposed method is based on the model in which interference includes a component with a rank-deficient correlation matrix. Using numerical simulation, we show that the proposed method allows one to ensure variance of the estimated arrival angle of the plane wave, which is close to the Cramer-Rao lower boundary and more efficient than the best-known MUSIC method. It is also shown that the proposed technique can be efficiently used for estimating the time dependence of the useful signal.

Printing three-dimensional tissue analogues with decellularized extracellular matrix bioink

PubMed Central

Pati, Falguni; Jang, Jinah; Ha, Dong-Heon; Won Kim, Sung; Rhie, Jong-Won; Shim, Jin-Hyung; Kim, Deok-Ho; Cho, Dong-Woo

2014-01-01

The ability to print and pattern all the components that make up a tissue (cells and matrix materials) in three dimensions to generate structures similar to tissues is an exciting prospect of bioprinting. However, the majority of the matrix materials used so far for bioprinting cannot represent the complexity of natural extracellular matrix (ECM) and thus are unable to reconstitute the intrinsic cellular morphologies and functions. Here, we develop a method for the bioprinting of cell-laden constructs with novel decellularized extracellular matrix (dECM) bioink capable of providing an optimized microenvironment conducive to the growth of three-dimensional structured tissue. We show the versatility and flexibility of the developed bioprinting process using tissue-specific dECM bioinks, including adipose, cartilage and heart tissues, capable of providing crucial cues for cells engraftment, survival and long-term function. We achieve high cell viability and functionality of the printed dECM structures using our bioprinting method. PMID:24887553

Catalytic Fast Pyrolysis of Cellulose Using Nano Zeolite and Zeolite/Matrix Catalysts in a GC/Micro-Pyrolyzer.

PubMed

Lee, Kyong-Hwan

2016-05-01

Cellulose, as a model compound of biomass, was catalyzed over zeolite (HY,.HZSM-5) and zeolite/matrix (HY/Clay, HM/Clay) in a GC/micro-pyrolyzer at 500 degrees C, to produce the valuable products. The catalysts used were pure zeolite and zeolite/matrix including 20 wt% matrix content, which were prepared into different particle sizes (average size; 0.1 mm, 1.6 mm) to study the effect of the particle size of the catalyst for the distribution of product yields. Catalytic pyrolysis had much more volatile products as light components and less content of sugars than pyrolysis only. This phenomenon was strongly influenced by the particle size of the catalyst in catalytic fast pyrolysis. Also, in zeolite and zeolite/matrix catalysts the zeolite type gave the dominant impact on the distribution of product yields.

Characteristic analysis on UAV-MIMO channel based on normalized correlation matrix.

PubMed

Gao, Xi jun; Chen, Zi li; Hu, Yong Jiang

2014-01-01

Based on the three-dimensional GBSBCM (geometrically based double bounce cylinder model) channel model of MIMO for unmanned aerial vehicle (UAV), the simple form of UAV space-time-frequency channel correlation function which includes the LOS, SPE, and DIF components is presented. By the methods of channel matrix decomposition and coefficient normalization, the analytic formula of UAV-MIMO normalized correlation matrix is deduced. This formula can be used directly to analyze the condition number of UAV-MIMO channel matrix, the channel capacity, and other characteristic parameters. The simulation results show that this channel correlation matrix can be applied to describe the changes of UAV-MIMO channel characteristics under different parameter settings comprehensively. This analysis method provides a theoretical basis for improving the transmission performance of UAV-MIMO channel. The development of MIMO technology shows practical application value in the field of UAV communication.

Characteristic Analysis on UAV-MIMO Channel Based on Normalized Correlation Matrix

PubMed Central

Xi jun, Gao; Zi li, Chen; Yong Jiang, Hu

2014-01-01

Based on the three-dimensional GBSBCM (geometrically based double bounce cylinder model) channel model of MIMO for unmanned aerial vehicle (UAV), the simple form of UAV space-time-frequency channel correlation function which includes the LOS, SPE, and DIF components is presented. By the methods of channel matrix decomposition and coefficient normalization, the analytic formula of UAV-MIMO normalized correlation matrix is deduced. This formula can be used directly to analyze the condition number of UAV-MIMO channel matrix, the channel capacity, and other characteristic parameters. The simulation results show that this channel correlation matrix can be applied to describe the changes of UAV-MIMO channel characteristics under different parameter settings comprehensively. This analysis method provides a theoretical basis for improving the transmission performance of UAV-MIMO channel. The development of MIMO technology shows practical application value in the field of UAV communication. PMID:24977185

Printing three-dimensional tissue analogues with decellularized extracellular matrix bioink

NASA Astrophysics Data System (ADS)

Pati, Falguni; Jang, Jinah; Ha, Dong-Heon; Won Kim, Sung; Rhie, Jong-Won; Shim, Jin-Hyung; Kim, Deok-Ho; Cho, Dong-Woo

2014-06-01

The ability to print and pattern all the components that make up a tissue (cells and matrix materials) in three dimensions to generate structures similar to tissues is an exciting prospect of bioprinting. However, the majority of the matrix materials used so far for bioprinting cannot represent the complexity of natural extracellular matrix (ECM) and thus are unable to reconstitute the intrinsic cellular morphologies and functions. Here, we develop a method for the bioprinting of cell-laden constructs with novel decellularized extracellular matrix (dECM) bioink capable of providing an optimized microenvironment conducive to the growth of three-dimensional structured tissue. We show the versatility and flexibility of the developed bioprinting process using tissue-specific dECM bioinks, including adipose, cartilage and heart tissues, capable of providing crucial cues for cells engraftment, survival and long-term function. We achieve high cell viability and functionality of the printed dECM structures using our bioprinting method.

STUDIES ON CARTILAGE

PubMed Central

Sheldon, Huntington; Robinson, Robert A.

1960-01-01

Electron microscope observations on rabbit ear cartilage following the administration of papain show that both the elastic component of the matrix and the amorphous material disappear leaving a matrix which consists of delicate fibrils which are presumed to be collagen. This unmasking of fibrils coincides with the appearance of an abnormal component in the electrophoretic pattern of the rabbit's serum. The chondrocytes show vacuoles in their cytoplasm which appear at the same time that the cells appear crenated in the light microscope. A ruffly appearance of the cell surface membrane coincides with this vacuolization, and vacuoles often appear open and in continuity with the extracellular space. The resurgence of the rabbit ear is accompanied by a reconstitution of both the amorphous material and the elastic component of the matrix. During this period numerous dilated cisternae of the endoplasmic reticulum which contain a moderately dense material are present in the chondrocyte cytoplasm. We have been unable to demonstrate a direct relationship between the elastic component of the matrix and a particular component of the chondrocyte cytoplasm, but it is clear that changes occur in the cartilage cell cytoplasm during both the depletion and reconstitution of the matrix. Previous studies on the effect of papain on elastic tissue are noted and the possible relationships between changes in the cells and matrix of this elastic cartilage are discussed. PMID:19866569

Oxide_Oxide Ceramic Matrix Composite (CMC) Exhaust Mixer Development in the NASA Environmentally Responsible Aviation (ERA) Project

NASA Technical Reports Server (NTRS)

Kiser, J. Douglas; Bansal, Narottam P.; Szelagowski, James; Sokhey, Jagdish; Heffernan, Tab; Clegg, Joseph; Pierluissi, Anthony; Riedell, Jim; Wyen, Travis; Atmur, Steven;

A Fully Non-Metallic Gas Turbine Engine Enabled by Additive Manufacturing Part I: System Analysis, Component Identification, Additive Manufacturing, and Testing of Polymer Composites

NASA Technical Reports Server (NTRS)

Grady, Joseph E.; Haller, William J.; Poinsatte, Philip E.; Halbig, Michael C.; Schnulo, Sydney L.; Singh, Mrityunjay; Weir, Don; Wali, Natalie; Vinup, Michael; Jones, Michael G.;

Comparative Proteomic Analysis of Normal and Collagen IX Null Mouse Cartilage Reveals Altered Extracellular Matrix Composition and Novel Components of the Collagen IX Interactome*

PubMed Central

Brachvogel, Bent; Zaucke, Frank; Dave, Keyur; Norris, Emma L.; Stermann, Jacek; Dayakli, Münire; Koch, Manuel; Gorman, Jeffrey J.; Bateman, John F.; Wilson, Richard

2013-01-01

The cartilage extracellular matrix is essential for endochondral bone development and joint function. In addition to the major aggrecan/collagen II framework, the interacting complex of collagen IX, matrilin-3, and cartilage oligomeric matrix protein (COMP) is essential for cartilage matrix stability, as mutations in Col9a1, Col9a2, Col9a3, Comp, and Matn3 genes cause multiple epiphyseal dysplasia, in which patients develop early onset osteoarthritis. In mice, collagen IX ablation results in severely disturbed growth plate organization, hypocellular regions, and abnormal chondrocyte shape. This abnormal differentiation is likely to involve altered cell-matrix interactions but the mechanism is not known. To investigate the molecular basis of the collagen IX null phenotype we analyzed global differences in protein abundance between wild-type and knock-out femoral head cartilage by capillary HPLC tandem mass spectrometry. We identified 297 proteins in 3-day cartilage and 397 proteins in 21-day cartilage. Components that were differentially abundant between wild-type and collagen IX-deficient cartilage included 15 extracellular matrix proteins. Collagen IX ablation was associated with dramatically reduced COMP and matrilin-3, consistent with known interactions. Matrilin-1, matrilin-4, epiphycan, and thrombospondin-4 levels were reduced in collagen IX null cartilage, providing the first in vivo evidence for these proteins belonging to the collagen IX interactome. Thrombospondin-4 expression was reduced at the mRNA level, whereas matrilin-4 was verified as a novel collagen IX-binding protein. Furthermore, changes in TGFβ-induced protein βig-h3 and fibronectin abundance were found in the collagen IX knock-out but not associated with COMP ablation, indicating specific involvement in the abnormal collagen IX null cartilage. In addition, the more widespread expression of collagen XII in the collagen IX-deficient cartilage suggests an attempted compensatory response to the absence of collagen IX. Our differential proteomic analysis of cartilage is a novel approach to identify candidate matrix protein interactions in vivo, underpinning further analysis of mutant cartilage lacking other matrix components or harboring disease-causing mutations. PMID:23530037

Shell extracts from the marine bivalve Pecten maximus regulate the synthesis of extracellular matrix in primary cultured human skin fibroblasts.

PubMed

Latire, Thomas; Legendre, Florence; Bigot, Nicolas; Carduner, Ludovic; Kellouche, Sabrina; Bouyoucef, Mouloud; Carreiras, Franck; Marin, Frédéric; Lebel, Jean-Marc; Galéra, Philippe; Serpentini, Antoine

2014-01-01

Mollusc shells are composed of more than 95% calcium carbonate and less than 5% of an organic matrix consisting mostly of proteins, glycoproteins and polysaccharides. Previous studies have elucidated the biological activities of the shell matrices from bivalve molluscs on skin, especially on the expression of the extracellular matrix components of fibroblasts. In this work, we have investigated the potential biological activities of shell matrix components extracted from the shell of the scallop Pecten maximus on human fibroblasts in primary culture. Firstly, we demonstrated that shell matrix components had different effects on general cellular activities. Secondly, we have shown that the shell matrix components stimulate the synthesis of type I and III collagens, as well as that of sulphated GAGs. The increased expression of type I collagen is likely mediated by the recruitment of transactivating factors (Sp1, Sp3 and human c-Krox) in the -112/-61 bp COL1A1 promoter region. Finally, contrarily to what was obtained in previous works, we demonstrated that the scallop shell extracts have only a small effect on cell migration during in vitro wound tests and have no effect on cell proliferation. Thus, our research emphasizes the potential use of shell matrix of Pecten maximus for dermo-cosmetic applications.

The Bioactivity of Cartilage Extracellular Matrix in Articular Cartilage Regeneration

PubMed Central

Sutherland, Amanda J.; Converse, Gabriel L.; Hopkins, Richard A.; Detamore, Michael S.

2014-01-01

Cartilage matrix is a particularly promising acellular material for cartilage regeneration given the evidence supporting its chondroinductive character. The ‘raw materials’ of cartilage matrix can serve as building blocks and signals for enhanced tissue regeneration. These matrices can be created by chemical or physical methods: physical methods disrupt cellular membranes and nuclei but may not fully remove all cell components and DNA, whereas chemical methods when combined with physical methods are particularly effective in fully decellularizing such materials. Critical endpoints include no detectable residual DNA or immunogenic antigens. It is important to first delineate between the sources of the cartilage matrix, i.e., derived from matrix produced by cells in vitro or from native tissue, and then to further characterize the cartilage matrix based on the processing method, i.e., decellularization or devitalization. With these distinctions, four types of cartilage matrices exist: decellularized native cartilage (DCC), devitalized native cartilage (DVC), decellularized cell derived matrix (DCCM), and devitalized cell derived matrix (DVCM). Delivery of cartilage matrix may be a straightforward approach without the need for additional cells or growth factors. Without additional biological additives, cartilage matrix may be attractive from a regulatory and commercialization standpoint. Source and delivery method are important considerations for clinical translation. Only one currently marketed cartilage matrix medical device is decellularized, although trends in filed patents suggest additional decellularized products may be available in the future. To choose the most relevant source and processing for cartilage matrix, qualifying testing needs to include targeting the desired application, optimizing delivery of the material, identify relevant FDA regulations, assess availability of raw materials, and immunogenic properties of the product. PMID:25044502

Escherichia coli biofilms have an organized and complex extracellular matrix structure.

PubMed

Hung, Chia; Zhou, Yizhou; Pinkner, Jerome S; Dodson, Karen W; Crowley, Jan R; Heuser, John; Chapman, Matthew R; Hadjifrangiskou, Maria; Henderson, Jeffrey P; Hultgren, Scott J

2013-09-10

Bacterial biofilms are ubiquitous in nature, and their resilience is derived in part from a complex extracellular matrix that can be tailored to meet environmental demands. Although common developmental stages leading to biofilm formation have been described, how the extracellular components are organized to allow three-dimensional biofilm development is not well understood. Here we show that uropathogenic Escherichia coli (UPEC) strains produce a biofilm with a highly ordered and complex extracellular matrix (ECM). We used electron microscopy (EM) techniques to image floating biofilms (pellicles) formed by UPEC. EM revealed intricately constructed substructures within the ECM that encase individual, spatially segregated bacteria with a distinctive morphology. Mutational and biochemical analyses of these biofilms confirmed curli as a major matrix component and revealed important roles for cellulose, flagella, and type 1 pili in pellicle integrity and ECM infrastructure. Collectively, the findings of this study elucidated that UPEC pellicles have a highly organized ultrastructure that varies spatially across the multicellular community. Bacteria can form biofilms in diverse niches, including abiotic surfaces, living cells, and at the air-liquid interface of liquid media. Encasing these cellular communities is a self-produced extracellular matrix (ECM) that can be composed of proteins, polysaccharides, and nucleic acids. The ECM protects biofilm bacteria from environmental insults and also makes the dissolution of biofilms very challenging. As a result, formation of biofilms within humans (during infection) or on industrial material (such as water pipes) has detrimental and costly effects. In order to combat bacterial biofilms, a better understanding of components required for biofilm formation and the ECM is required. This study defined the ECM composition and architecture of floating pellicle biofilms formed by Escherichia coli.

Using Separable Nonnegative Matrix Factorization Techniques for the Analysis of Time-Resolved Raman Spectra.

PubMed

Luce, Robert; Hildebrandt, Peter; Kuhlmann, Uwe; Liesen, Jörg

2016-09-01

The key challenge of time-resolved Raman spectroscopy is the identification of the constituent species and the analysis of the kinetics of the underlying reaction network. In this work we present an integral approach that allows for determining both the component spectra and the rate constants simultaneously from a series of vibrational spectra. It is based on an algorithm for nonnegative matrix factorization that is applied to the experimental data set following a few pre-processing steps. As a prerequisite for physically unambiguous solutions, each component spectrum must include one vibrational band that does not significantly interfere with the vibrational bands of other species. The approach is applied to synthetic "experimental" spectra derived from model systems comprising a set of species with component spectra differing with respect to their degree of spectral interferences and signal-to-noise ratios. In each case, the species involved are connected via monomolecular reaction pathways. The potential and limitations of the approach for recovering the respective rate constants and component spectra are discussed. © The Author(s) 2016.

The Use of Matrix Training to Promote Generative Language with Children with Autism

ERIC Educational Resources Information Center

Frampton, Sarah E.; Wymer, Sarah C.; Hansen, Bethany; Shillingsburg, M. Alice

2016-01-01

Matrix training consists of planning instruction by arranging components of desired skills across 2 axes. After training with diagonal targets that each combine 2 unique skill components, responses to nondiagonal targets, consisting of novel combinations of the components, may emerge. A multiple-probe design across participants was used to…

[Resolving excitation emission matrix spectroscopy of estuarine CDOM with parallel factor analysis and its application in organic pollution monitoring].

PubMed

Guo, Wei-Dong; Huang, Jian-Ping; Hong, Hua-Sheng; Xu, Jing; Deng, Xun

2010-06-01

The distribution and estuarine behavior of fluorescent components of chromophoric dissolved organic matter (CDOM) from Jiulong Estuary were determined by fluorescence excitation emission matrix spectroscopy (EEMs) combined with parallel factor analysis (PARAFAC). The feasibility of these components as tracers for organic pollution in estuarine environments was also evaluated. Four separate fluorescent components were identified by PARAFAC, including three humic-like components (C1: 240, 310/382 nm; C2: 230, 250, 340/422 nm; C4: 260, 390/482 nm) and one protein-like components (C3: 225, 275/342 nm). These results indicated that UV humic-like peak A area designated by traditional "peak-picking method" was not a single peak but actually a combination of several fluorescent components, and it also had inherent links to so-called marine humic-like peak M or terrestrial humic-like peak C. Component C2 which include peak M decreased with increase of salinity in Jiulong Estuary, demonstrating that peak M can not be thought as the specific indicator of the "marine" humic-like component. Two humic-like components C1 and C2 showed additional behavior in the turbidity maximum region (salinity < 6) and then conservative mixing behavior for the rest estuarine region, while humic-like components C4 showed conservative mixing behavior for the whole estuarine region. However, the protein-like component C3 showed nonconservative mixing behavior, suggesting it had autochthonous estuarine origin. EEMs-PARAFAC can provide fluorescent fingerprint to differentiate the DOM features for three tributaries of Jiulong River. The observed linear relationships between humic-like components and absorption coefficient a (280) with chemical oxygen demand (COD) and biological oxygen demand (BOD5) suggest that the optical properties of CDOM may provide a fast in-situ way to monitor the variation of the degree of organic pollution in estuarine environments.

High aspect ratio template and method for producing same for central and peripheral nerve repair

NASA Technical Reports Server (NTRS)

Sakamoto, Jeff S. (Inventor); Chan, Christina (Inventor); Tuszynski, Mark Henry (Inventor); Mehrotra, Sumit (Inventor); Gros, Thomas (Inventor)

2011-01-01

Millimeter to nano-scale structures manufactured using a multi-component polymer fiber matrix are disclosed. The use of dissimilar polymers allows the selective dissolution of the polymers at various stages of the manufacturing process. In one application, biocompatible matrixes may be formed with long pore length and small pore size. The manufacturing process begins with a first polymer fiber arranged in a matrix formed by a second polymer fiber. End caps may be attached to provide structural support and the polymer fiber matrix selectively dissolved away leaving only the long polymer fibers. These may be exposed to another product, such as a biocompatible gel to form a biocompatible matrix. The polymer fibers may then be selectively dissolved leaving only a biocompatible gel scaffold with the pores formed by the dissolved polymer fibers. The scaffolds may be used in, among other applications, the repair of central and peripheral nerves. Scaffolds for the repair of peripheral nerves may include a reservoir for the sustained release of nerve growth factor. The scaffolds may also include a multifunctional polyelectrolyte layer for the sustained release of nerve growth factor and enhance biocompatibility.

Application of Composite Materials to Truck Components: Leaf Springs and Propeller Shafts for 5-Ton Trucks

DTIC Science & Technology

1981-11-01

Fiberglass-Epoxy Resin Matrix Composites 2(L ABSTRACT (Caautlrue am reverse de bf IHI wee•a’y d Identify by block number) The objective of the program was to...Army truck are designed using resin matrix composite materials. Both design studies and prototype fabrication and testing are included in the program...For the leaf springs (both front and rear) a hybrid design using steel DD FOR 143 ED#T1ON OF I NOV65 IS OBSOLETE SECURITY CLASSIFICATION OF THIS PAGE

Gelatinized wheat starch influences crystallization behaviour and structure of roll-in shortenings in laminated bakery products.

PubMed

Mattice, Kristin D; Marangoni, Alejandro G

2018-03-15

One hydrogenated and one non-hydrogenated shortening were baked with isolated components of a croissant matrix, including crystalline wheat starch, gelatinized wheat starch, gluten, and formed gluten network. The impact of the matrix components on fat crystallization was analyzed for polymorphism using powder X-ray diffraction, solid fat content by pulsed nuclear magnetic resonance and thermal behaviour by differential scanning calorimetry. When compared to results obtained from croissants prepared with the respective shortenings, samples containing gelatinized wheat starch displayed notably similar results: polymorphic conversion, from the β' to β form over storage, and visually broader peaks in the melting endotherms indicating a greater temperature was required to completely melt all of the fat. All other component mixtures behaved similar to the respective fats in bulk. The measured rate of crystallization was greater in samples containing gelatinized wheat starch, indicating that the gelatinized starch could act as a nucleation site to speed crystallization. Copyright © 2017 Elsevier Ltd. All rights reserved.

Organic Aerosol Composition and Sources in Pasadena, California during the 2010 CalNex Campaign

EPA Science Inventory

Organic aerosols (OA) in Pasadena are characterized using multiple measurements from the California Research at the Nexus of Air Quality and Climate Change (CalNex) campaign. Five OA components are identified using positive matrix factorization including hydrocarbon-like OA (HOA) ...

Engineering Breast Cancer Microenvironments and 3D Bioprinting

PubMed Central

Belgodere, Jorge A.; King, Connor T.; Bursavich, Jacob B.; Burow, Matthew E.; Martin, Elizabeth C.; Jung, Jangwook P.

2018-01-01

The extracellular matrix (ECM) is a critical cue to direct tumorigenesis and metastasis. Although two-dimensional (2D) culture models have been widely employed to understand breast cancer microenvironments over the past several decades, the 2D models still exhibit limited success. Overwhelming evidence supports that three dimensional (3D), physiologically relevant culture models are required to better understand cancer progression and develop more effective treatment. Such platforms should include cancer-specific architectures, relevant physicochemical signals, stromal–cancer cell interactions, immune components, vascular components, and cell-ECM interactions found in patient tumors. This review briefly summarizes how cancer microenvironments (stromal component, cell-ECM interactions, and molecular modulators) are defined and what emerging technologies (perfusable scaffold, tumor stiffness, supporting cells within tumors and complex patterning) can be utilized to better mimic native-like breast cancer microenvironments. Furthermore, this review emphasizes biophysical properties that differ between primary tumor ECM and tissue sites of metastatic lesions with a focus on matrix modulation of cancer stem cells, providing a rationale for investigation of underexplored ECM proteins that could alter patient prognosis. To engineer breast cancer microenvironments, we categorized technologies into two groups: (1) biochemical factors modulating breast cancer cell-ECM interactions and (2) 3D bioprinting methods and its applications to model breast cancer microenvironments. Biochemical factors include matrix-associated proteins, soluble factors, ECMs, and synthetic biomaterials. For the application of 3D bioprinting, we discuss the transition of 2D patterning to 3D scaffolding with various bioprinting technologies to implement biophysical cues to model breast cancer microenvironments. PMID:29881724

Shell Extracts from the Marine Bivalve Pecten maximus Regulate the Synthesis of Extracellular Matrix in Primary Cultured Human Skin Fibroblasts

PubMed Central

Latire, Thomas; Legendre, Florence; Bigot, Nicolas; Carduner, Ludovic; Kellouche, Sabrina; Bouyoucef, Mouloud; Carreiras, Franck; Marin, Frédéric; Lebel, Jean-Marc; Galéra, Philippe; Serpentini, Antoine

2014-01-01

Mollusc shells are composed of more than 95% calcium carbonate and less than 5% of an organic matrix consisting mostly of proteins, glycoproteins and polysaccharides. Previous studies have elucidated the biological activities of the shell matrices from bivalve molluscs on skin, especially on the expression of the extracellular matrix components of fibroblasts. In this work, we have investigated the potential biological activities of shell matrix components extracted from the shell of the scallop Pecten maximus on human fibroblasts in primary culture. Firstly, we demonstrated that shell matrix components had different effects on general cellular activities. Secondly, we have shown that the shell matrix components stimulate the synthesis of type I and III collagens, as well as that of sulphated GAGs. The increased expression of type I collagen is likely mediated by the recruitment of transactivating factors (Sp1, Sp3 and human c-Krox) in the −112/−61 bp COL1A1 promoter region. Finally, contrarily to what was obtained in previous works, we demonstrated that the scallop shell extracts have only a small effect on cell migration during in vitro wound tests and have no effect on cell proliferation. Thus, our research emphasizes the potential use of shell matrix of Pecten maximus for dermo-cosmetic applications. PMID:24949635

COMPADRE: an R and web resource for pathway activity analysis by component decompositions.

PubMed

Ramos-Rodriguez, Roberto-Rafael; Cuevas-Diaz-Duran, Raquel; Falciani, Francesco; Tamez-Peña, Jose-Gerardo; Trevino, Victor

2012-10-15

The analysis of biological networks has become essential to study functional genomic data. Compadre is a tool to estimate pathway/gene sets activity indexes using sub-matrix decompositions for biological networks analyses. The Compadre pipeline also includes one of the direct uses of activity indexes to detect altered gene sets. For this, the gene expression sub-matrix of a gene set is decomposed into components, which are used to test differences between groups of samples. This procedure is performed with and without differentially expressed genes to decrease false calls. During this process, Compadre also performs an over-representation test. Compadre already implements four decomposition methods [principal component analysis (PCA), Isomaps, independent component analysis (ICA) and non-negative matrix factorization (NMF)], six statistical tests (t- and f-test, SAM, Kruskal-Wallis, Welch and Brown-Forsythe), several gene sets (KEGG, BioCarta, Reactome, GO and MsigDB) and can be easily expanded. Our simulation results shown in Supplementary Information suggest that Compadre detects more pathways than over-representation tools like David, Babelomics and Webgestalt and less false positives than PLAGE. The output is composed of results from decomposition and over-representation analyses providing a more complete biological picture. Examples provided in Supplementary Information show the utility, versatility and simplicity of Compadre for analyses of biological networks. Compadre is freely available at http://bioinformatica.mty.itesm.mx:8080/compadre. The R package is also available at https://sourceforge.net/p/compadre.

Extracellular DNA Is Essential for Maintaining Bordetella Biofilm Integrity on Abiotic Surfaces and in the Upper Respiratory Tract of Mice

PubMed Central

Deora, Rajendar

2011-01-01

Bacteria form complex and highly elaborate surface adherent communities known as biofilms which are held together by a self-produced extracellular matrix. We have previously shown that by adopting a biofilm mode of existence in vivo, the Gram negative bacterial pathogens Bordetella bronchiseptica and Bordetella pertussis are able to efficiently colonize and persist in the mammalian respiratory tract. In general, the bacterial biofilm matrix includes polysaccharides, proteins and extracellular DNA (eDNA). In this report, we investigated the function of DNA in Bordetella biofilm development. We show that DNA is a significant component of Bordetella biofilm matrix. Addition of DNase I at the initiation of biofilm growth inhibited biofilm formation. Treatment of pre-established mature biofilms formed under both static and flow conditions with DNase I led to a disruption of the biofilm biomass. We next investigated whether eDNA played a role in biofilms formed in the mouse respiratory tract. DNase I treatment of nasal biofilms caused considerable dissolution of the biofilm biomass. In conclusion, these results suggest that eDNA is a crucial structural matrix component of both in vitro and in vivo formed Bordetella biofilms. This is the first evidence for the ability of DNase I to disrupt bacterial biofilms formed on host organs. PMID:21347299

The Comprehensive Dropout Prevention Plan.

ERIC Educational Resources Information Center

Broward County School Board, Fort Lauderdale, FL.

The Comprehensive Dropout Prevention Plan utilizes the resources of Broward County public schools and the community for dropout prevention. A matrix of dropout prevention options has been assembled from both existing programs and from new program designs. General components of the plan include the following: (1) dropout retrieval activities; (2)…

Nanocomposites in food packaging – A review

USDA-ARS?s Scientific Manuscript database

A nanocomposite is a multiphase material derived from the combination of two or more components, including a matrix (continuous phase) and a discontinuous nano-dimensional phase with at least one nano-sized dimension (i.e. less than 100 nm). The main types of nanostructures are presented in this ch...

Creating Opportunities: Good Practice in Small Business Training for Australian Rural Women.

ERIC Educational Resources Information Center

Simpson, Lyn; Daws, Leonie; Wood, Leanne

2002-01-01

To overcome barriers to participation in small business training faced by rural Australian women, training needs and delivery issues were identified and a good practice matrix was developed with the following components: marketing, content, delivery, support, impact, and innovation. Underlying principles included unique needs, diversity, use of…

DYNALIST II : A Computer Program for Stability and Dynamic Response Analysis of Rail Vehicle Systems : Volume 3. Technical Report Addendum.

DOT National Transportation Integrated Search

1976-07-01

Several new capabilities have been added to the DYNALIST II computer program. These include: (1) a component matrix generator that operates as a 3-D finite element modeling program where elements consist of rigid bodies, flexural bodies, wheelsets, s...

Low-Cost Resin Transfer Molding Process Developed for High-Temperature Polyimide Matrix Composites

NASA Technical Reports Server (NTRS)

1996-01-01

The use of high-temperature polymer matrix composites (PMC's) in aircraft engine applications can significantly reduce engine weight and improve performance and fuel efficiency. High-temperature PMC's, such as those based on the PMR-15 polyimide matrix resin developed by the NASA Lewis Research Center, have been used extensively in military applications where performance improvements have justified their use regardless of the cost involved in producing the component. However, in commercial engines cost is a primary driver, and PMC components must be produced at costs comparable to those of the metal components that they will replace.

Method Developed for Improving the Thermomechanical Properties of Silicon Carbide Matrix Composites

NASA Technical Reports Server (NTRS)

Bhatt, Ramakrishna T.; DiCarlo, James A.

2004-01-01

Today, a major thrust for achieving engine components with improved thermal capability is the development of fiber-reinforced silicon-carbide (SiC) matrix composites. These materials are not only lighter and capable of higher use temperatures than state-of-the-art metallic alloys and oxide matrix composites (approx. 1100 C), but they can provide significantly better static and dynamic toughness than unreinforced silicon-based monolithic ceramics. However, for successful application in advanced engine systems, the SiC matrix composites should be able to withstand component service stresses and temperatures for the desired component lifetime. Since the high-temperature structural life of ceramic materials is typically controlled by creep-induced flaw growth, a key composite property requirement is the ability to display high creep resistance under these conditions. Also, because of the possibility of severe thermal gradients in the components, the composites should provide maximum thermal conductivity to minimize the development of thermal stresses. State-of-the-art SiC matrix composites are typically fabricated via a three-step process: (1) fabrication of a component-shaped architectural preform reinforced by high-performance fibers, (2) chemical vapor infiltration of a fiber coating material such as boron nitride (BN) into the preform, and (3) infiltration of a SiC matrix into the remaining porous areas in the preform. Generally, the highest performing composites have matrices fabricated by the CVI process, which produces a SiC matrix typically more thermally stable and denser than matrices formed by other approaches. As such, the CVI SiC matrix is able to provide better environmental protection to the coated fibers, plus provide the composite with better resistance to crack propagation. Also, the denser CVI SiC matrix should provide optimal creep resistance and thermal conductivity to the composite. However, for adequate preform infiltration, the CVI SiC matrix process typically has to be conducted at temperatures below 1100 C, which results in a SiC matrix that is fairly dense, but contains metastable atomic defects and is nonstoichiometric because of a small amount of excess silicon. Because these defects typically exist at the matrix grain boundaries, they can scatter thermal phonons and degrade matrix creep resistance by enhancing grain-boundary sliding. To eliminate these defects and improve the thermomechanical properties of ceramic composites with CVI SiC matrices, researchers at the NASA Glenn Research Center developed a high-temperature treatment process that can be used after the CVI SiC matrix is deposited into the fiber preform.

Fault detection of helicopter gearboxes using the multi-valued influence matrix method

NASA Technical Reports Server (NTRS)

Chin, Hsinyung; Danai, Kourosh; Lewicki, David G.

1993-01-01

In this paper we investigate the effectiveness of a pattern classifying fault detection system that is designed to cope with the variability of fault signatures inherent in helicopter gearboxes. For detection, the measurements are monitored on-line and flagged upon the detection of abnormalities, so that they can be attributed to a faulty or normal case. As such, the detection system is composed of two components, a quantization matrix to flag the measurements, and a multi-valued influence matrix (MVIM) that represents the behavior of measurements during normal operation and at fault instances. Both the quantization matrix and influence matrix are tuned during a training session so as to minimize the error in detection. To demonstrate the effectiveness of this detection system, it was applied to vibration measurements collected from a helicopter gearbox during normal operation and at various fault instances. The results indicate that the MVIM method provides excellent results when the full range of faults effects on the measurements are included in the training set.

3D biomaterial matrix to support long term, full thickness, immuno-competent human skin equivalents with nervous system components.

PubMed

Vidal, Sarah E Lightfoot; Tamamoto, Kasey A; Nguyen, Hanh; Abbott, Rosalyn D; Cairns, Dana M; Kaplan, David L

2018-04-24

Current commercially available human skin equivalents (HSEs) are used for relatively short term studies (∼1 week) due in part to the time-dependent contraction of the collagen gel-based matrix and the limited cell types and skin tissue components utilized. In contrast, here we describe a new matrix consisting of a silk-collagen composite system that provides long term, stable cultivation with reduced contraction and degradation over time. This matrix supports full thickness skin equivalents which include nerves. The unique silk-collagen composite system preserves cell-binding domains of collagen while maintaining the stability and mechanics of the skin system for long-term culture with silk. The utility of this new composite protein-based biomaterial was demonstrated by bioengineering full thickness human skin systems using primary cells, including nerves and immune cells to establish an HSE with a neuro-immuno-cutaneous system. The HSEs with neurons and hypodermis, compared to in vitro skin-only HSEs controls, demonstrated higher secretion of pro-inflammatory cytokines. Proteomics analysis confirmed the presence of several proteins associated with inflammation across all sample groups, but HSEs with neurons had the highest amount of detected protein due to the complexity of the model. This improved, in vitro full thickness HSE model system utilizes cross-linked silk-collagen as the biomaterial and allows reduced reliance on animal models and provides a new in vitro tissue system for the assessment of chronic responses related to skin diseases and drug discovery. Copyright © 2018 Elsevier Ltd. All rights reserved.

Teaching the extracellular matrix and introducing online databases within a multidisciplinary course with i-cell-MATRIX: A student-centered approach.

PubMed

Sousa, João Carlos; Costa, Manuel João; Palha, Joana Almeida

2010-03-01

The biochemistry and molecular biology of the extracellular matrix (ECM) is difficult to convey to students in a classroom setting in ways that capture their interest. The understanding of the matrix's roles in physiological and pathological conditions study will presumably be hampered by insufficient knowledge of its molecular structure. Internet-available resources can bridge the division between the molecular details and ECM's biological properties and associated processes. This article presents an approach to teach the ECM developed for first year medical undergraduates who, working in teams: (i) Explore a specific molecular component of the matrix, (ii) identify a disease in which the component is implicated, (iii) investigate how the component's structure/function contributes to ECM' supramolecular organization in physiological and in pathological conditions, and (iv) share their findings with colleagues. The approach-designated i-cell-MATRIX-is focused on the contribution of individual components to the overall organization and biological functions of the ECM. i-cell-MATRIX is student centered and uses 5 hours of class time. Summary of results and take home message: A "1-minute paper" has been used to gather student feedback on the impact of i-cell-MATRIX. Qualitative analysis of student feedback gathered in three consecutive years revealed that students appreciate the approach's reliance on self-directed learning, the interactivity embedded and the demand for deeper insights on the ECM. Learning how to use internet biomedical resources is another positive outcome. Ninety percent of students recommend the activity for subsequent years. i-cell-MATRIX is adaptable by other medical schools which may be looking for an approach that achieves higher student engagement with the ECM. Copyright © 2010 International Union of Biochemistry and Molecular Biology, Inc.

An Algorithm for the Hierarchical Organization of Path Diagrams and Calculation of Components of Expected Covariance.

ERIC Educational Resources Information Center

Boker, Steven M.; McArdle, J. J.; Neale, Michael

2002-01-01

Presents an algorithm for the production of a graphical diagram from a matrix formula in such a way that its components are logically and hierarchically arranged. The algorithm, which relies on the matrix equations of J. McArdle and R. McDonald (1984), calculates the individual path components of expected covariance between variables and…

A group matrix representation relevant to scales of measurement of clinical disease states via stratified vectors.

PubMed

Sawamura, Jitsuki; Morishita, Shigeru; Ishigooka, Jun

2016-02-09

Previously, we applied basic group theory and related concepts to scales of measurement of clinical disease states and clinical findings (including laboratory data). To gain a more concrete comprehension, we here apply the concept of matrix representation, which was not explicitly exploited in our previous work. Starting with a set of orthonormal vectors, called the basis, an operator Rj (an N-tuple patient disease state at the j-th session) was expressed as a set of stratified vectors representing plural operations on individual components, so as to satisfy the group matrix representation. The stratified vectors containing individual unit operations were combined into one-dimensional square matrices [Rj]s. The [Rj]s meet the matrix representation of a group (ring) as a K-algebra. Using the same-sized matrix of stratified vectors, we can also express changes in the plural set of [Rj]s. The method is demonstrated on simple examples. Despite the incompleteness of our model, the group matrix representation of stratified vectors offers a formal mathematical approach to clinical medicine, aligning it with other branches of natural science.

Activation product transport in fusion reactors. [RAPTOR

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

Klein, A.C.

1983-01-01

Activated corrosion and neutron sputtering products will enter the coolant and/or tritium breeding material of fusion reactor power plants and experiments and cause personnel access problems. Radiation levels around plant components due to these products will cause difficulties with maintenance and repair operations throughout the plant. Similar problems are experienced around fission reactor systems. The determination of the transport of radioactive corrosion and neutron sputtering products through the system is achieved using the computer code RAPTOR. This code calculates the mass transfer of a number of activation products based on the corrosion and sputtering rates through the system, the depositionmore » and release characteristics of various plant components, the neturon flux spectrum, as well as other plant parameters. RAPTOR assembles a system of first order linear differential equations into a matrix equation based upon the reactor system parameters. Included in the transfer matrix are the deposition and erosion coefficients, and the decay and activation data for the various plant nodes and radioactive isotopes. A source vector supplies the corrosion and neutron sputtering source rates. This matrix equation is then solved using a matrix operator technique to give the specific activity distribution of each radioactive species throughout the plant. Once the amount of mass transfer is determined, the photon transport due to the radioactive corrosion and sputtering product sources can be evaluated, and dose rates around the plant components of interest as a function of time can be determined. This method has been used to estimate the radiation hazards around a number of fusion reactor system designs.« less

Advanced technology for extended endurance alkaline fuel cells

NASA Technical Reports Server (NTRS)

Sheibley, D. W.; Martin, R. A.

1987-01-01

Advanced components have been developed for alkaline fuel cells with a view to the satisfaction of NASA Space Station design requirements for extended endurance. The components include a platinum-on-carbon catalyst anode, a potassium titanate-bonded electrolyte matrix, a lightweight graphite electrolyte reservoir plate, a gold-plated nickel-perforated foil electrode substrate, a polyphenylene sulfide cell edge frame material, and a nonmagnesium cooler concept. When incorporated into the alkaline fuel cell unit, these components are expected to yield regenerative operation in a low earth orbit Space Station with a design life greater than 5 years.

Two Genetic Loci Produce Distinct Carbohydrate-Rich Structural Components of the Pseudomonas aeruginosa Biofilm Matrix

PubMed Central

Friedman, Lisa; Kolter, Roberto

2004-01-01

Pseudomonas aeruginosa forms biofilms, which are cellular aggregates encased in an extracellular matrix. Molecular genetics studies of three common autoaggregative phenotypes, namely wrinkled colonies, pellicles, and solid-surface-associated biofilms, led to the identification of two loci, pel and psl, that are involved in the production of carbohydrate-rich components of the biofilm matrix. The pel gene cluster is involved in the production of a glucose-rich matrix material in P. aeruginosa strain PA14 (L. Friedman and R. Kolter, Mol. Microbiol. 51:675-690, 2004). Here we investigate the role of the pel gene cluster in P. aeruginosa strain ZK2870 and identify a second genetic locus, termed psl, involved in the production of a mannose-rich matrix material. The 11 predicted protein products of the psl genes are homologous to proteins involved in carbohydrate processing. P. aeruginosa is thus able to produce two distinct carbohydrate-rich matrix materials. Either carbohydrate-rich matrix component appears to be sufficient for mature biofilm formation, and at least one of them is required for mature biofilm formation in P. aeruginosa strains PA14 and ZK2870. PMID:15231777

Two genetic loci produce distinct carbohydrate-rich structural components of the Pseudomonas aeruginosa biofilm matrix.

PubMed

Friedman, Lisa; Kolter, Roberto

2004-07-01

Pseudomonas aeruginosa forms biofilms, which are cellular aggregates encased in an extracellular matrix. Molecular genetics studies of three common autoaggregative phenotypes, namely wrinkled colonies, pellicles, and solid-surface-associated biofilms, led to the identification of two loci, pel and psl, that are involved in the production of carbohydrate-rich components of the biofilm matrix. The pel gene cluster is involved in the production of a glucose-rich matrix material in P. aeruginosa strain PA14 (L. Friedman and R. Kolter, Mol. Microbiol. 51:675-690, 2004). Here we investigate the role of the pel gene cluster in P. aeruginosa strain ZK2870 and identify a second genetic locus, termed psl, involved in the production of a mannose-rich matrix material. The 11 predicted protein products of the psl genes are homologous to proteins involved in carbohydrate processing. P. aeruginosa is thus able to produce two distinct carbohydrate-rich matrix materials. Either carbohydrate-rich matrix component appears to be sufficient for mature biofilm formation, and at least one of them is required for mature biofilm formation in P. aeruginosa strains PA14 and ZK2870. Copyright 2004 American Society for Microbiology

CEMCAN Software Enhanced for Predicting the Properties of Woven Ceramic Matrix Composites

NASA Technical Reports Server (NTRS)

Murthy, Pappu L. N.; Mital, Subodh K.; DiCarlo, James A.

2000-01-01

Major advancements are needed in current high-temperature materials to meet the requirements of future space and aeropropulsion structural components. Ceramic matrix composites (CMC's) are one class of materials that are being evaluated as candidate materials for many high-temperature applications. Past efforts to improve the performance of CMC's focused primarily on improving the properties of the fiber, interfacial coatings, and matrix constituents as individual phases. Design and analysis tools must take into consideration the complex geometries, microstructures, and fabrication processes involved in these composites and must allow the composite properties to be tailored for optimum performance. Major accomplishments during the past year include the development and inclusion of woven CMC micromechanics methodology into the CEMCAN (Ceramic Matrix Composites Analyzer) computer code. The code enables one to calibrate a consistent set of constituent properties as a function of temperature with the aid of experimentally measured data.

Synchronized and sustained release of multiple components in silymarin from erodible glyceryl monostearate matrix system.

PubMed

Lu, Cheng; Lu, Yi; Chen, Jian; Zhang, Wentong; Wu, Wei

2007-05-01

Development of sustained delivery systems for herbal medicines was very difficult because of their complexity in composition. The concept of synchronized release from sustained release systems, which is characterized by release of multiple components in their original ratio that defines a herbal medicine, served as the basis for keeping the original pharmacological activity. In this study, erodible matrix systems based on glyceryl monostearate and polyethylene glycol 6000 or poloxamer 188 were prepared to perform strict control on synchronized release of the five active components of silymarin, i.e. taxifolin, silychrystin, silydianin, isosilybin and silybin. The matrix system was prepared by a melt fusion method. Synchronized release was achieved with high similarity factor f(2) values between each two of the five components. Erosion profiles of the matrix were in good correlation with release profiles of the five components, showing erosion-controlled release mechanisms. Through tuning some of the formulation variables, the system can be adjusted for synchronized and sustained release of silymarin for oral administration. In vitro hemolysis study indicated that the synchronized release samples showed a much better stabilizing effect on erythrocyte membrane.

Anisotropic ray trace

NASA Astrophysics Data System (ADS)

Lam, Wai Sze Tiffany

Optical components made of anisotropic materials, such as crystal polarizers and crystal waveplates, are widely used in many complex optical system, such as display systems, microlithography, biomedical imaging and many other optical systems, and induce more complex aberrations than optical components made of isotropic materials. The goal of this dissertation is to accurately simulate the performance of optical systems with anisotropic materials using polarization ray trace. This work extends the polarization ray tracing calculus to incorporate ray tracing through anisotropic materials, including uniaxial, biaxial and optically active materials. The 3D polarization ray tracing calculus is an invaluable tool for analyzing polarization properties of an optical system. The 3x3 polarization ray tracing P matrix developed for anisotropic ray trace assists tracking the 3D polarization transformations along a ray path with series of surfaces in an optical system. To better represent the anisotropic light-matter interactions, the definition of the P matrix is generalized to incorporate not only the polarization change at a refraction/reflection interface, but also the induced optical phase accumulation as light propagates through the anisotropic medium. This enables realistic modeling of crystalline polarization elements, such as crystal waveplates and crystal polarizers. The wavefront and polarization aberrations of these anisotropic components are more complex than those of isotropic optical components and can be evaluated from the resultant P matrix for each eigen-wavefront as well as for the overall image. One incident ray refracting or reflecting into an anisotropic medium produces two eigenpolarizations or eigenmodes propagating in different directions. The associated ray parameters of these modes necessary for the anisotropic ray trace are described in Chapter 2. The algorithms to calculate the P matrix from these ray parameters are described in Chapter 3 for anisotropic ray tracing. x. Chapter 4 presents the data reduction of the P matrix of a crystal waveplate. The diattenuation is embedded in the singular values of P. The retardance is divided into two parts: (A) The physical retardance induced by OPLs and surface interactions, and (B) the geometrical transformation induced by geometry of a ray path, which is calculated by the geometrical transform Q matrix. The Q matrix of an anisotropic intercept is derived from the generalization of s- and p-bases at the anisotropic intercept; the p basis is not confined to the plane of incidence due to the anisotropic refraction or reflection. Chapter 5 shows how the multiple P matrices associated with the eigenmodes resulting from propagation through multiple anisotropic surfaces can be combined into one P matrix when the multiple modes interfere in their overlapping regions. The resultant P matrix contains diattenuation induced at each surface interaction as well as the retardance due to ray propagation and total internal reflections. The polarization aberrations of crystal waveplates and crystal polarizers are studied in Chapter 6 and Chapter 7. A wavefront simulated by a grid of rays is traced through the anisotropic system and the resultant grid of rays is analyzed. The analysis is complicated by the ray doubling effects and the partially overlapping eigen-wavefronts propagating in various directions. The wavefront and polarization aberrations of each eigenmode can be evaluated from the electric field distributions. The overall polarization at the plane of interest or the image quality at the image plane are affected by each of these eigen-wavefronts. Isotropic materials become anisotropic due to stress, strain, or applied electric or magnetic fields. In Chapter 8, the P matrix for anisotropic materials is extended to ray tracing in stress birefringent materials which are treated as spatially varying anisotropic materials. Such simulations can predict the spatial retardance variation throughout the stressed optical component and its effects on the point spread function and modulation transfer function for different incident polarizations. The anisotropic extension of the P matrix also applies to other anisotropic optical components, such as anisotropic diffractive optical elements and anisotropic thin films. It systematically keeps track of polarization transformation in 3D global Cartesian coordinates of a ray propagating through series of anisotropic and isotropic optical components with arbitrary orientations. The polarization ray tracing calculus with this generalized P matrix provides a powerful tool for optical ray trace and allows comprehensive analysis of complex optical system. (Abstract shortened by UMI.).

The Performance of A Sampled Data Delay Lock Loop Implemented with a Kalman Loop Filter.

DTIC Science & Technology

1980-01-01

que for analysis is computer simulation. Other techniques include state variable techniques and z-transform methods. Since the Kalman filter is linear...LOGIC NOT SHOWN Figure 2. Block diagram of the sampled data delay lock loop (SDDLL) Es A/ A 3/A/ Figure 3. Sampled error voltage ( Es ) as a function of...from a sum of two components. The first component is the previous filtered es - timate advanced one step forward by the state transition matrix. The 8

Preliminary design of a solar central receiver for a site-specific repowering application (Saguaro Power Plant). Volume IV. Appendixes. Final report, October 1982-September 1983

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

Weber, E.R.

1983-09-01

The appendixes for the Saguaro Power Plant includes the following: receiver configuration selection report; cooperating modes and transitions; failure modes analysis; control system analysis; computer codes and simulation models; procurement package scope descriptions; responsibility matrix; solar system flow diagram component purpose list; thermal storage component and system test plans; solar steam generator tube-to-tubesheet weld analysis; pipeline listing; management control schedule; and system list and definitions.

Portable automated imaging in complex ceramics with a microwave interference scanning system

NASA Astrophysics Data System (ADS)

Goitia, Ryan M.; Schmidt, Karl F.; Little, Jack R.; Ellingson, William A.; Green, William; Franks, Lisa P.

2013-01-01

An improved portable microwave interferometry system has been automated to permit rapid examination of components with minimal operator attendance. Functionalities include stereo and multiplexed, frequency-modulated at multiple frequencies, producing layered volumetric images of complex ceramic structures. The technique has been used to image composite ceramic armor and ceramic matrix composite components, as well as other complex dielectric materials. The system utilizes Evisive Scan microwave interference scanning technique. Validation tests include artificial and in-service damage of ceramic armor, surrogates and ceramic matrix composite samples. Validation techniques include micro-focus x-ray and computed tomography imaging. The microwave interference scanning technique has demonstrated detection of cracks, interior laminar features and variations in material properties such as density. The image yields depth information through phase angle manipulation, and shows extent of feature and relative dielectric property information. It requires access to only one surface, and no coupling medium. Data are not affected by separation of layers of dielectric material, such as outer over-wrap. Test panels were provided by the US Army Research Laboratory, and the US Army Tank Automotive Research, Development and Engineering Center (TARDEC), who with the US Air Force Research Laboratory have supported this work.

A Fully Non-Metallic Gas Turbine Engine Enabled by Additive Manufacturing

NASA Technical Reports Server (NTRS)

Grady, Joseph E.

2015-01-01

The Non-Metallic Gas Turbine Engine project, funded by NASA Aeronautics Research Institute, represents the first comprehensive evaluation of emerging materials and manufacturing technologies that will enable fully nonmetallic gas turbine engines. This will be achieved by assessing the feasibility of using additive manufacturing technologies to fabricate polymer matrix composite and ceramic matrix composite turbine engine components. The benefits include: 50 weight reduction compared to metallic parts, reduced manufacturing costs, reduced part count and rapid design iterations. Two high payoff metallic components have been identified for replacement with PMCs and will be fabricated using fused deposition modeling (FDM) with high temperature polymer filaments. The CMC effort uses a binder jet process to fabricate silicon carbide test coupons and demonstration articles. Microstructural analysis and mechanical testing will be conducted on the PMC and CMC materials. System studies will assess the benefits of fully nonmetallic gas turbine engine in terms of fuel burn, emissions, reduction of part count, and cost. The research project includes a multidisciplinary, multiorganization NASA - industry team that includes experts in ceramic materials and CMCs, polymers and PMCs, structural engineering, additive manufacturing, engine design and analysis, and system analysis.

Evaluation of Ceramic Matrix Composite Technology for Aircraft Turbine Engine Applications

NASA Technical Reports Server (NTRS)

Halbig, Michael C.; Jaskowiak, Martha H.; Kiser, James D.; Zhu, Dongming

2013-01-01

The goals of the NASA Environmentally Responsible Aviation (ERA) Project are to reduce the NO(x) emissions, fuel burn, and noise from turbine engines. In order to help meet these goals, commercially-produced ceramic matrix composite (CMC) components and environmental barrier coatings (EBCs) are being evaluated as parts and panels. The components include a CMC combustor liner, a CMC high pressure turbine vane, and a CMC exhaust nozzle as well as advanced EBCs that are tailored to the operating conditions of the CMC combustor and vane. The CMC combustor (w/EBC) could provide 2700 F temperature capability with less component cooling requirements to allow for more efficient combustion and reductions in NOx emissions. The CMC vane (w/EBC) will also have temperature capability up to 2700 F and allow for reduced fuel burn. The CMC mixer nozzle will offer reduced weight and improved mixing efficiency to provide reduced fuel burn. The main objectives are to evaluate the manufacturability of the complex-shaped components and to evaluate their performance under simulated engine operating conditions. Progress in CMC component fabrication, evaluation, and testing is presented in which the goal is to advance from the proof of concept validation (TRL 3) to a system/subsystem or prototype demonstration in a relevant environment (TRL 6).

A Fully Non-Metallic Gas Turbine Engine Enabled by Additive Manufacturing

NASA Technical Reports Server (NTRS)

Grady, Joseph E.; Halbig, Michael C.; Singh, Mrityunjay

2015-01-01

In a NASA Aeronautics Research Institute (NARI) sponsored program entitled "A Fully Non-Metallic Gas Turbine Engine Enabled by Additive Manufacturing," evaluation of emerging materials and additive manufacturing technologies was carried out. These technologies may enable fully non-metallic gas turbine engines in the future. This paper highlights the results of engine system trade studies which were carried out to estimate reduction in engine emissions and fuel burn enabled due to advanced materials and manufacturing processes. A number of key engine components were identified in which advanced materials and additive manufacturing processes would provide the most significant benefits to engine operation. In addition, feasibility of using additive manufacturing technologies to fabricate gas turbine engine components from polymer and ceramic matrix composite were demonstrated. A wide variety of prototype components (inlet guide vanes (IGV), acoustic liners, engine access door, were additively manufactured using high temperature polymer materials. Ceramic matrix composite components included first stage nozzle segments and high pressure turbine nozzle segments for a cooled doublet vane. In addition, IGVs and acoustic liners were tested in simulated engine conditions in test rigs. The test results are reported and discussed in detail.

A Fully Non-Metallic Gas Turbine Engine Enabled by Additive Manufacturing

NASA Technical Reports Server (NTRS)

Grady, Joseph E.; Halbig, Michael C.; Singh, Mrityunjay

2015-01-01

In a NASA Aeronautics Research Institute (NARI) sponsored program entitled "A Fully Non-Metallic Gas Turbine Engine Enabled by Additive Manufacturing", evaluation of emerging materials and additive manufacturing technologies was carried out. These technologies may enable fully non-metallic gas turbine engines in the future. This paper highlights the results of engine system trade studies which were carried out to estimate reduction in engine emissions and fuel burn enabled due to advanced materials and manufacturing processes. A number of key engine components were identified in which advanced materials and additive manufacturing processes would provide the most significant benefits to engine operation. In addition, feasibility of using additive manufacturing technologies to fabricate gas turbine engine components from polymer and ceramic matrix composite were demonstrated. A wide variety of prototype components (inlet guide vanes (IGV), acoustic liners, engine access door) were additively manufactured using high temperature polymer materials. Ceramic matrix composite components included first stage nozzle segments and high pressure turbine nozzle segments for a cooled doublet vane. In addition, IGVs and acoustic liners were tested in simulated engine conditions in test rigs. The test results are reported and discussed in detail.

Cooled Ceramic Matrix Composite Propulsion Structures Demonstrated

NASA Technical Reports Server (NTRS)

Jaskowiak, Martha H.; Dickens, Kevin W.

2005-01-01

NASA's Next Generation Launch Technology (NGLT) Program has successfully demonstrated cooled ceramic matrix composite (CMC) technology in a scramjet engine test. This demonstration represented the world s largest cooled nonmetallic matrix composite panel fabricated for a scramjet engine and the first cooled nonmetallic composite to be tested in a scramjet facility. Lightweight, high-temperature, actively cooled structures have been identified as a key technology for enabling reliable and low-cost space access. Tradeoff studies have shown this to be the case for a variety of launch platforms, including rockets and hypersonic cruise vehicles. Actively cooled carbon and CMC structures may meet high-performance goals at significantly lower weight, while improving safety by operating with a higher margin between the design temperature and material upper-use temperature. Studies have shown that using actively cooled CMCs can reduce the weight of the cooled flow-path component from 4.5 to 1.6 lb/sq ft and the weight of the propulsion system s cooled surface area by more than 50 percent. This weight savings enables advanced concepts, increased payload, and increased range. The ability of the cooled CMC flow-path components to operate over 1000 F hotter than the state-of-the-art metallic concept adds system design flexibility to space-access vehicle concepts. Other potential system-level benefits include smaller fuel pumps, lower part count, lower cost, and increased operating margin.

Matrix MetalloProteinases (MMPs) andTissue Inhibitors of MetalloProteinases (TIMPs): positive and negative regulators intumor cell adhesion

PubMed Central

Bourboulia, Dimitra; Stetler-Stevenson, William G.

2010-01-01

Cells adhere to one another and/or to matrices that surround them. Regulation of cell-cell (intercellular) and cell-matrix adhesion is tightly controlled in normal cells, however, defects in cell adhesion are common in the majority of humancancers. Multilateral communication among tumor cells with the extracellular matrix (ECM) and neighbor cells is accomplished through adhesion molecules, ECM components, proteolytic enzymes and their endogenous inhibitors. There is sufficient evidence to suggest that reduced adherence is a tumor cell propertyengaged during tumor progression. Tumor cells acquire the ability to change shape, detach and easily move through spaces disorganizing the normal tissue architecture. This property is due to changes in expression levels of adhesion molecules and/or due to elevated levels of secreted proteolytic enzymes, including matrix metalloproteinases (MMPs). Among other roles, MMPsdegrade the ECMand, therefore, prepare the path for tumor cells to migrate, invade and spread to distant secondary areas, where they form metastasis. Tissue Inhibitors of Metalloproteinases or TIMPs control MMP activities and, therefore, minimize matrix degradation. Both MMPs and TIMPs are involved in tissue remodeling and decisively regulate tumor cell progression including tumor angiogenesis. In this review, we describe and discuss data that support the important role of MMPs and TIMPs in cancer cell adhesion and tumor progression. PMID:20470890

Atmospheric pressure matrix-assisted laser desorption ionization as a plume diagnostic tool in laser evaporation methods

NASA Astrophysics Data System (ADS)

Callahan, John H.; Galicia, Marsha C.; Vertes, Akos

2002-09-01

Laser evaporation techniques, including matrix-assisted pulsed laser evaporation (MAPLE), are attracting increasing attention due to their ability to deposit thin layers of undegraded synthetic and biopolymers. Laser evaporation methods can be implemented in reflection geometry with the laser and the substrate positioned on the same side of the target. In some applications (e.g. direct write, DW), however, transmission geometry is used, i.e. the thin target is placed between the laser and the substrate. In this case, the laser pulse perforates the target and transfers some target material to the substrate. In order to optimize evaporation processes it is important to know the composition of the target plume and the material deposited from the plume. We used a recently introduced analytical method, atmospheric pressure matrix-assisted laser desorption ionization (AP-MALDI) to characterize the ionic components of the plume both in reflection and in transmission geometry. This technique can also be used to directly probe materials deposited on surfaces (such as glass slides) by laser evaporation methods. The test compound (small peptides, e.g. Angiotensin I, ATI or Substance P) was mixed with a MALDI matrix (α-cyano-4-hydroxycinnamic acid (CHCA), sinapinic acid (SA) or 2,5-dihydroxybenzoic acid (DHB)) and applied to the stainless steel (reflection geometry) or transparent conducting (transmission geometry) target holder. In addition to the classical dried droplet method, we also used electrospray target deposition to gain better control of crystallite size, thickness and homogeneity. The target was mounted in front of the inlet orifice of an ion trap mass spectrometer (IT-MS) that sampled the ionic components of the plume generated by a nitrogen laser. We studied the effect of several parameters, such as, the orifice to target distance, illumination geometry, extracting voltage distribution and sample preparation on the generated ions. Various analyte-matrix and matrix-matrix cluster ions were observed with relatively low abundance of the matrix ions.

Emerging Applications of Ceramic and Metal Matrix Composites

NASA Astrophysics Data System (ADS)

Krishnamoorthy, Divya; Ramolina, Dheeyana; Sandou, Sherleena

2012-07-01

Almost 500 papers were presented during the 43 sessions of the 27th Annual Cocoa Beach Conference & Exposition on Advanced Ceramics & Composites, which was organized by the Engineering Ceramics Division of the American Ceramic Society and sponsored by several federal agencies: NASA Glenn Research Center, the Army Research Office, the Department of Energy, and the Air Force Office of Scientific Research. Many of these papers focused on composites, both ceramic and metal matrix, and discussed mechanical behavior, design, fibers/interfaces, processing, and applications. Potential applications under development include components for armor, nuclear energy, and automobiles. A few of these applications have reached commercialization.

Safe Life Propulsion Design Technologies (3rd Generation Propulsion Research and Technology)

NASA Technical Reports Server (NTRS)

Ellis, Rod

2000-01-01

The tasks outlined in this viewgraph presentation on safe life propulsion design technologies (third generation propulsion research and technology) include the following: (1) Ceramic matrix composite (CMC) life prediction methods; (2) Life prediction methods for ultra high temperature polymer matrix composites for reusable launch vehicle (RLV) airframe and engine application; (3) Enabling design and life prediction technology for cost effective large-scale utilization of MMCs and innovative metallic material concepts; (4) Probabilistic analysis methods for brittle materials and structures; (5) Damage assessment in CMC propulsion components using nondestructive characterization techniques; and (6) High temperature structural seals for RLV applications.

THz spectral data analysis and components unmixing based on non-negative matrix factorization methods

NASA Astrophysics Data System (ADS)

Ma, Yehao; Li, Xian; Huang, Pingjie; Hou, Dibo; Wang, Qiang; Zhang, Guangxin

2017-04-01

In many situations the THz spectroscopic data observed from complex samples represent the integrated result of several interrelated variables or feature components acting together. The actual information contained in the original data might be overlapping and there is a necessity to investigate various approaches for model reduction and data unmixing. The development and use of low-rank approximate nonnegative matrix factorization (NMF) and smooth constraint NMF (CNMF) algorithms for feature components extraction and identification in the fields of terahertz time domain spectroscopy (THz-TDS) data analysis are presented. The evolution and convergence properties of NMF and CNMF methods based on sparseness, independence and smoothness constraints for the resulting nonnegative matrix factors are discussed. For general NMF, its cost function is nonconvex and the result is usually susceptible to initialization and noise corruption, and may fall into local minima and lead to unstable decomposition. To reduce these drawbacks, smoothness constraint is introduced to enhance the performance of NMF. The proposed algorithms are evaluated by several THz-TDS data decomposition experiments including a binary system and a ternary system simulating some applications such as medicine tablet inspection. Results show that CNMF is more capable of finding optimal solutions and more robust for random initialization in contrast to NMF. The investigated method is promising for THz data resolution contributing to unknown mixture identification.

THz spectral data analysis and components unmixing based on non-negative matrix factorization methods.

PubMed

Ma, Yehao; Li, Xian; Huang, Pingjie; Hou, Dibo; Wang, Qiang; Zhang, Guangxin

2017-04-15

In many situations the THz spectroscopic data observed from complex samples represent the integrated result of several interrelated variables or feature components acting together. The actual information contained in the original data might be overlapping and there is a necessity to investigate various approaches for model reduction and data unmixing. The development and use of low-rank approximate nonnegative matrix factorization (NMF) and smooth constraint NMF (CNMF) algorithms for feature components extraction and identification in the fields of terahertz time domain spectroscopy (THz-TDS) data analysis are presented. The evolution and convergence properties of NMF and CNMF methods based on sparseness, independence and smoothness constraints for the resulting nonnegative matrix factors are discussed. For general NMF, its cost function is nonconvex and the result is usually susceptible to initialization and noise corruption, and may fall into local minima and lead to unstable decomposition. To reduce these drawbacks, smoothness constraint is introduced to enhance the performance of NMF. The proposed algorithms are evaluated by several THz-TDS data decomposition experiments including a binary system and a ternary system simulating some applications such as medicine tablet inspection. Results show that CNMF is more capable of finding optimal solutions and more robust for random initialization in contrast to NMF. The investigated method is promising for THz data resolution contributing to unknown mixture identification. Copyright © 2017 Elsevier B.V. All rights reserved.

Targeting Learning Needs in an Australian Aid Project in Thailand.

ERIC Educational Resources Information Center

Kinder, Rex; Karawanan, Chaisak

1996-01-01

The Thailand Land Titling Project includes a training and development component aimed at long-term sustainability. A training target matrix was developed to identify the knowledge, skills, experience, and performance standards required and needs for training at various levels. Six broad and flexible career paths allow for logical succession,…

Analysis of wind tunnel test results for a 9.39-per cent scale model of a VSTOL fighter/attack aircraft. Volume 3: Effects of configuration variations from baseline

NASA Technical Reports Server (NTRS)

Lummus, J. R.; Joyce, G. T.; Omalley, C. D.

1980-01-01

The aerodynamic characteristics of the components of the baseline E205 configuration is presented. Geometric variations from the baseline E205 configuration are also given including a matrix of conrad longitudinal locations and strake shapes.

Mat-Rix-Toe: Improving Writing through a Game-Based Project in Linear Algebra

ERIC Educational Resources Information Center

Graham-Squire, Adam; Farnell, Elin; Stockton, Julianna Connelly

2014-01-01

The Mat-Rix-Toe project utilizes a matrix-based game to deepen students' understanding of linear algebra concepts and strengthen students' ability to express themselves mathematically. The project was administered in three classes using slightly different approaches, each of which included some editing component to encourage the…

APPLICATION OF THE MODELS-3 COMMUNITY MULTI-SCALE AIR QUALITY (CMAQ) MODEL SYSTEM TO SOS/NASHVILLE 1999

EPA Science Inventory

The Models-3 Community Multi-scale Air Quality (CMAQ) model, first released by the USEPA in 1999 (Byun and Ching. 1999), continues to be developed and evaluated. The principal components of the CMAQ system include a comprehensive emission processor known as the Sparse Matrix O...

The Performance of the Linear Logistic Test Model When the Q-Matrix Is Misspecified: A Simulation Study

ERIC Educational Resources Information Center

MacDonald, George T.

2014-01-01

A simulation study was conducted to explore the performance of the linear logistic test model (LLTM) when the relationships between items and cognitive components were misspecified. Factors manipulated included percent of misspecification (0%, 1%, 5%, 10%, and 15%), form of misspecification (under-specification, balanced misspecification, and…

Global Analysis Reveals the Complexity of the Human Glomerular Extracellular Matrix

PubMed Central

Byron, Adam; Humphries, Jonathan D.; Randles, Michael J.; Carisey, Alex; Murphy, Stephanie; Knight, David; Brenchley, Paul E.; Zent, Roy; Humphries, Martin J.

2014-01-01

The glomerulus contains unique cellular and extracellular matrix (ECM) components, which are required for intact barrier function. Studies of the cellular components have helped to build understanding of glomerular disease; however, the full composition and regulation of glomerular ECM remains poorly understood. We used mass spectrometry-based proteomics of enriched ECM extracts for a global analysis of human glomerular ECM in vivo and identified a tissue-specific proteome of 144 structural and regulatory ECM proteins. This catalog includes all previously identified glomerular components plus many new and abundant components. Relative protein quantification showed a dominance of collagen IV, collagen I, and laminin isoforms in the glomerular ECM together with abundant collagen VI and TINAGL1. Protein network analysis enabled the creation of a glomerular ECM interactome, which revealed a core of highly connected structural components. More than one half of the glomerular ECM proteome was validated using colocalization studies and data from the Human Protein Atlas. This study yields the greatest number of ECM proteins relative to previous investigations of whole glomerular extracts, highlighting the importance of sample enrichment. It also shows that the composition of glomerular ECM is far more complex than previously appreciated and suggests that many more ECM components may contribute to glomerular development and disease processes. The mass spectrometry proteomics data have been deposited to the ProteomeXchange Consortium with the dataset identifier PXD000456. PMID:24436468

Metal Matrix Composite LOX Turbopump Housing via Novel Tool-less Net-Shape Pressure Infiltration Casting Technology

NASA Technical Reports Server (NTRS)

Shah, Sandeep; Lee, Jonathan; Bhat, Biliyar; Wells, Doug; Gregg, Wayne; Marsh, Matthew; Genge, Gary; Forbes, John; Salvi, Alex; Cornie, James A.

2003-01-01

Metal matrix composites for propulsion components offer high performance and affordability, resulting in low weight and cost. The following sections in this viewgraph presentation describe the pressure infiltration casting of a metal matrix composite LOX turbopump housing: 1) Baseline Pump Design and Stress Analysis; 2) Tool-less Advanced Pressure Infiltration Casting Process; 3) Preform Splicing and Joining for Large Components such as Pump Housing; 4) Fullscale Pump Housing Redesign.

Molecular energy dissipation in nanoscale networks of dentin matrix protein 1 is strongly dependent on ion valence

NASA Astrophysics Data System (ADS)

Adams, J.; Fantner, G. E.; Fisher, L. W.; Hansma, P. K.

2008-09-01

The fracture resistance of biomineralized tissues such as bone, dentin, and abalone is greatly enhanced through the nanoscale interactions of stiff inorganic mineral components with soft organic adhesive components. A proper understanding of the interactions that occur within the organic component, and between the organic and inorganic components, is therefore critical for a complete understanding of the mechanics of these tissues. In this paper, we use atomic force microscope (AFM) force spectroscopy and dynamic force spectroscopy to explore the effect of ionic interactions within a nanoscale system consisting of networks of dentin matrix protein 1 (DMP1) (a component of both bone and dentin organic matrix), a mica surface and an AFM tip. We find that DMP1 is capable of dissipating large amounts of energy through an ion-mediated mechanism, and that the effectiveness increases with increasing ion valence.

Characterization of PMR-15 polyimide composition in thermo-oxidatively exposed graphite fiber composites

NASA Technical Reports Server (NTRS)

Alston, W. B.

1980-01-01

The contributions of individual resin components to total resin weight loss in 600 F air aged Celion 6000/PMR-15 polyimide composites were determined from the overall resin weight loss in the composite by chemically separating the PMR-15 matrix resin into its monomeric components. The individual resin components were also analyzed by spectroscopic techniques in order to elucidate curing and degradation mechanisms of the PMR-15 matrix resin. The isothermal weight loss of the individual resin components during prolonged 600 F thermo-oxidative aging of the composite was correlated to the changes observed in the Fourier Transform infrared spectra and Fourier Transform nuclear magnetic resonance spectra of the individual resin components. The correlation was used to identify the molecular site of the thermo-oxidative changes in PMR-15 polyimide matrix resin during 600 F curing the prolonged 600 F thermo-oxidative aging.

LC-MS/MS signal suppression effects in the analysis of pesticides in complex environmental matrices.

PubMed

Choi, B K; Hercules, D M; Gusev, A I

2001-02-01

The application of LC separation and mobile phase additives in addressing LC-MS/MS matrix signal suppression effects for the analysis of pesticides in a complex environmental matrix was investigated. It was shown that signal suppression is most significant for analytes eluting early in the LC-MS analysis. Introduction of different buffers (e.g. ammonium formate, ammonium hydroxide, formic acid) into the LC mobile phase was effective in improving signal correlation between the matrix and standard samples. The signal improvement is dependent on buffer concentration as well as LC separation of the matrix components. The application of LC separation alone was not effective in addressing suppression effects when characterizing complex matrix samples. Overloading of the LC column by matrix components was found to significantly contribute to analyte-matrix co-elution and suppression of signal. This signal suppression effect can be efficiently compensated by 2D LC (LC-LC) separation techniques. The effectiveness of buffers and LC separation in improving signal correlation between standard and matrix samples is discussed.

System for solving diagnosis and hitting set problems

NASA Technical Reports Server (NTRS)

Vatan, Farrokh (Inventor); Fijany, Amir (Inventor)

2007-01-01

The diagnosis problem arises when a system's actual behavior contradicts the expected behavior, thereby exhibiting symptoms (a collection of conflict sets). System diagnosis is then the task of identifying faulty components that are responsible for anomalous behavior. To solve the diagnosis problem, the present invention describes a method for finding the minimal set of faulty components (minimal diagnosis set) that explain the conflict sets. The method includes acts of creating a matrix of the collection of conflict sets, and then creating nodes from the matrix such that each node is a node in a search tree. A determination is made as to whether each node is a leaf node or has any children nodes. If any given node has children nodes, then the node is split until all nodes are leaf nodes. Information gathered from the leaf nodes is used to determine the minimal diagnosis set.

Thermophoretically induced large-scale deformations around microscopic heat centers

NASA Astrophysics Data System (ADS)

Puljiz, Mate; Orlishausen, Michael; Köhler, Werner; Menzel, Andreas M.

2016-05-01

Selectively heating a microscopic colloidal particle embedded in a soft elastic matrix is a situation of high practical relevance. For instance, during hyperthermic cancer treatment, cell tissue surrounding heated magnetic colloidal particles is destroyed. Experiments on soft elastic polymeric matrices suggest a very long-ranged, non-decaying radial component of the thermophoretically induced displacement fields around the microscopic heat centers. We theoretically confirm this conjecture using a macroscopic hydrodynamic two-fluid description. Both thermophoretic and elastic effects are included in this theory. Indeed, we find that the elasticity of the environment can cause the experimentally observed large-scale radial displacements in the embedding matrix. Additional experiments confirm the central role of elasticity. Finally, a linearly decaying radial component of the displacement field in the experiments is attributed to the finite size of the experimental sample. Similar results are obtained from our theoretical analysis under modified boundary conditions.

Tasseled cap transformation for HJ multispectral remote sensing data

NASA Astrophysics Data System (ADS)

Han, Ling; Han, Xiaoyong

2015-12-01

The tasseled cap transformation of remote sensing data has been widely used in environment, agriculture, forest and ecology. Tasseled cap transformation coefficients matrix of HJ multi-spectrum data has been established through Givens rotation matrix to rotate principal component transform vector to whiteness, greenness and blueness direction of ground object basing on 24 scenes year-round HJ multispectral remote sensing data. The whiteness component enhances the brightness difference of ground object, and the greenness component preserves more detailed information of vegetation change while enhances the vegetation characteristic, and the blueness component significantly enhances factory with blue plastic house roof around the town and also can enhance brightness of water. Tasseled cap transformation coefficients matrix of HJ will enhance the application effect of HJ multispectral remote sensing data in their application fields.

Identification of matrix metalloproteinase inhibitors by chemical arrays.

PubMed

Kawatani, Makoto; Fukushima, Yukako; Kondoh, Yasumitsu; Honda, Kaori; Sekine, Tomomi; Yamaguchi, Yoshiki; Taniguchi, Naoyuki; Osada, Hiroyuki

2015-01-01

Matrix metalloproteinases (MMPs) are zinc-dependent endopeptidases that degrade many extracellular matrix components and that have been implicated in the pathogenesis of various human diseases including cancer metastasis. Here, we screened MMP-9 inhibitors using photo-cross-linked chemical arrays, which can detect small-molecule ligand-protein interactions on a chip in a high-throughput manner. The array slides were probed sequentially with His-MMP-9, anti-His antibody, and a Cy5-labeled secondary antibody and then scanned with a microarray scanner. We obtained 27 hits among 24,275 compounds from the NPDepo library; 2 of the identified compounds (isoxazole compound 1 and naphthofluorescein) inhibited MMP-9 enzyme activity in vitro. We further explored 17 analogs of 1 and found that compound 18 had the strongest inhibitory activity. Compound 18 also inhibited other MMPs, including MMP-2, MMP-12, and MMP-13 and significantly inhibited cell migration in human fibrosarcoma HT1080 cells. These results suggest that 18 is a broad-spectrum MMP inhibitor.

Components, structure, biogenesis and function of the Hydra extracellular matrix in regeneration, pattern formation and cell differentiation.

PubMed

Sarras, Michael P

2012-01-01

The body wall of Hydra is organized as an epithelial bilayer (ectoderm and endoderm) with an intervening extracellular matrix (ECM), termed mesoglea by early biologists. Morphological studies have determined that Hydra ECM is composed of two basal lamina layers positioned at the base of each epithelial layer with an intervening interstitial matrix. Molecular and biochemical analyses of Hydra ECM have established that it contains components similar to those seen in more complicated vertebrate species. These components include such macromolecules as laminin, type IV collagen, and various fibrillar collagens. These components are synthesized in a complicated manner involving cross-talk between the epithelial bilayer. Any perturbation to ECM biogenesis leads to a blockage in Hydra morphogenesis. Blockage in ECM/cell interactions in the adult polyp also leads to problems in epithelial transdifferentiation processes. In terms of biophysical parameters, Hydra ECM is highly flexible; a property that facilitates continuous movements along the organism's longitudinal and radial axis. This is in contrast to the more rigid matrices often found in vertebrates. The flexible nature of Hydra ECM can in part now be explained by the unique structure of the organism's type IV collagen and fibrillar collagens. This review will focus on Hydra ECM in regard to: 1) its general structure, 2) its molecular composition, 3) the biophysical basis for the flexible nature of Hydra's ECM, 4) the relationship of the biogenesis of Hydra ECM to regeneration of body form, and 5) the functional role of Hydra ECM during pattern formation and cell differentiation.

The influence of extracelluar matrix on intramuscular and extramuscular adipogenesis

USDA-ARS?s Scientific Manuscript database

The extracellular matrix (ECM) and specific ECM components can have a major influence on cell growth, development and phenotype. The influence of the ECM and ECM components on adipogenesis in vivo and in vitro will be reviewed. Engelbreth-Holm-Swarm (EHS) substratum and laminin per se markedly incre...

CCARES: A computer algorithm for the reliability analysis of laminated CMC components

NASA Technical Reports Server (NTRS)

Duffy, Stephen F.; Gyekenyesi, John P.

1993-01-01

Structural components produced from laminated CMC (ceramic matrix composite) materials are being considered for a broad range of aerospace applications that include various structural components for the national aerospace plane, the space shuttle main engine, and advanced gas turbines. Specifically, these applications include segmented engine liners, small missile engine turbine rotors, and exhaust nozzles. Use of these materials allows for improvements in fuel efficiency due to increased engine temperatures and pressures, which in turn generate more power and thrust. Furthermore, this class of materials offers significant potential for raising the thrust-to-weight ratio of gas turbine engines by tailoring directions of high specific reliability. The emerging composite systems, particularly those with silicon nitride or silicon carbide matrix, can compete with metals in many demanding applications. Laminated CMC prototypes have already demonstrated functional capabilities at temperatures approaching 1400 C, which is well beyond the operational limits of most metallic materials. Laminated CMC material systems have several mechanical characteristics which must be carefully considered in the design process. Test bed software programs are needed that incorporate stochastic design concepts that are user friendly, computationally efficient, and have flexible architectures that readily incorporate changes in design philosophy. The CCARES (Composite Ceramics Analysis and Reliability Evaluation of Structures) program is representative of an effort to fill this need. CCARES is a public domain computer algorithm, coupled to a general purpose finite element program, which predicts the fast fracture reliability of a structural component under multiaxial loading conditions.

Testing of self-repairing composite airplane components by use of CAI and the release of the repair chemicals from carefully inserted small tubes

NASA Astrophysics Data System (ADS)

Dry, Carolyn

2007-04-01

The research on self repair of airplane components, under an SBIR phase II with Wright Patterson Air Force Base, has investigated the attributes and best end use applications for such a technology. These attributes include issues related to manufacturability, cost, potential benefits such as weight reduction, and cost reduction. The goal of our research has been to develop self-repairing composites with unique strength for air vehicles. Our revolutionary approach involves the autonomous release of repair chemicals from within the composite matrix itself. The repair agents are contained in hollow, structural fibers that are embedded within the matrix. Under stress, the composite senses external environmental factors and reacts by releasing the repair agents from within the hollow vessels. This autonomous response occurs wherever and whenever cracking, debonding or other matrix damage transpires. Superior performance over the life of the composite is achieved through this self-repairing mechanism. The advantages to the military would be safely executed missions, fewer repairs and eventually lighter vehicles. In particular the research has addressed the issues by correlating the impact of the various factors, such as 1) delivery vessel placement, shape/size and effect on composite strength, chemicals released and their effect on the matrix, release trigger and efficacy and any impact on matrix properties 2) impact of composite processing methods that involve heat and pressure on the repair vessels. Our self repairing system can be processed at temperatures of 300-350F, repairs in less than 30 seconds and does not damage the composite by repair fiber insertion or chemical release. Scaling up and manufacture of components has revealed that anticipating potential problems allowed us to avoid those associated with processing temperatures and pressures. The presentation will focus on compression after impact testing and the placement of repair fibers/tubes into prepreg laminates.

Characterizing fluorescent dissolved organic matter in a membrane bioreactor via excitation-emission matrix combined with parallel factor analysis.

PubMed

Maqbool, Tahir; Quang, Viet Ly; Cho, Jinwoo; Hur, Jin

2016-06-01

In this study, we successfully tracked the dynamic changes in different constitutes of bound extracellular polymeric substances (bEPS), soluble microbial products (SMP), and permeate during the operation of bench scale membrane bioreactors (MBRs) via fluorescence excitation-emission matrix (EEM) combined with parallel factor analysis (PARAFAC). Three fluorescent groups were identified, including two protein-like (tryptophan-like C1 and tyrosine-like C2) and one microbial humic-like components (C3). In bEPS, protein-like components were consistently more dominant than C3 during the MBR operation, while their relative abundance in SMP depended on aeration intensities. C1 of bEPS exhibited a linear correlation (R(2)=0.738; p<0.01) with bEPS amounts in sludge, and C2 was closely related to the stability of sludge. The protein-like components were more greatly responsible for membrane fouling. Our study suggests that EEM-PARAFAC can be a promising monitoring tool to provide further insight into process evaluation and membrane fouling during MBR operation. Copyright © 2016 Elsevier Ltd. All rights reserved.

Programmable 3D silk bone marrow niche for platelet generation ex vivo and modeling of megakaryopoiesis pathologies

PubMed Central

Di Buduo, Christian A.; Wray, Lindsay S.; Tozzi, Lorenzo; Malara, Alessandro; Chen, Ying; Ghezzi, Chiara E.; Smoot, Daniel; Sfara, Carla; Antonelli, Antonella; Spedden, Elise; Bruni, Giovanna; Staii, Cristian; De Marco, Luigi; Magnani, Mauro; Kaplan, David L.

2015-01-01

We present a programmable bioengineered 3-dimensional silk-based bone marrow niche tissue system that successfully mimics the physiology of human bone marrow environment allowing us to manufacture functional human platelets ex vivo. Using stem/progenitor cells, megakaryocyte function and platelet generation were recorded in response to variations in extracellular matrix components, surface topography, stiffness, coculture with endothelial cells, and shear forces. Millions of human platelets were produced and showed to be functional based on multiple activation tests. Using adult hematopoietic progenitor cells our system demonstrated the ability to reproduce key steps of thrombopoiesis, including alterations observed in diseased states. A critical feature of the system is the use of natural silk protein biomaterial allowing us to leverage its biocompatibility, nonthrombogenic features, programmable mechanical properties, and surface binding of cytokines, extracellular matrix components, and endothelial-derived proteins. This in turn offers new opportunities for the study of blood component production ex vivo and provides a superior tissue system for the study of pathologic mechanisms of human platelet production. PMID:25575540

Multiple component end-member mixing model of dilution: hydrochemical effects of construction water at Yucca Mountain, Nevada, USA

NASA Astrophysics Data System (ADS)

Lu, Guoping; Sonnenthal, Eric L.; Bodvarsson, Gudmundur S.

2008-12-01

The standard dual-component and two-member linear mixing model is often used to quantify water mixing of different sources. However, it is no longer applicable whenever actual mixture concentrations are not exactly known because of dilution. For example, low-water-content (low-porosity) rock samples are leached for pore-water chemical compositions, which therefore are diluted in the leachates. A multicomponent, two-member mixing model of dilution has been developed to quantify mixing of water sources and multiple chemical components experiencing dilution in leaching. This extended mixing model was used to quantify fracture-matrix interaction in construction-water migration tests along the Exploratory Studies Facility (ESF) tunnel at Yucca Mountain, Nevada, USA. The model effectively recovers the spatial distribution of water and chemical compositions released from the construction water, and provides invaluable data on the matrix fracture interaction. The methodology and formulations described here are applicable to many sorts of mixing-dilution problems, including dilution in petroleum reservoirs, hydrospheres, chemical constituents in rocks and minerals, monitoring of drilling fluids, and leaching, as well as to environmental science studies.

Integrating Nonadditive Genomic Relationship Matrices into the Study of Genetic Architecture of Complex Traits.

PubMed

Nazarian, Alireza; Gezan, Salvador A

2016-03-01

The study of genetic architecture of complex traits has been dramatically influenced by implementing genome-wide analytical approaches during recent years. Of particular interest are genomic prediction strategies which make use of genomic information for predicting phenotypic responses instead of detecting trait-associated loci. In this work, we present the results of a simulation study to improve our understanding of the statistical properties of estimation of genetic variance components of complex traits, and of additive, dominance, and genetic effects through best linear unbiased prediction methodology. Simulated dense marker information was used to construct genomic additive and dominance matrices, and multiple alternative pedigree- and marker-based models were compared to determine if including a dominance term into the analysis may improve the genetic analysis of complex traits. Our results showed that a model containing a pedigree- or marker-based additive relationship matrix along with a pedigree-based dominance matrix provided the best partitioning of genetic variance into its components, especially when some degree of true dominance effects was expected to exist. Also, we noted that the use of a marker-based additive relationship matrix along with a pedigree-based dominance matrix had the best performance in terms of accuracy of correlations between true and estimated additive, dominance, and genetic effects. © The American Genetic Association 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Health monitoring method for composite materials

DOEpatents

Watkins, Jr., Kenneth S.; Morris, Shelby J [Hampton, VA

2011-04-12

An in-situ method for monitoring the health of a composite component utilizes a condition sensor made of electrically conductive particles dispersed in a polymeric matrix. The sensor is bonded or otherwise formed on the matrix surface of the composite material. Age-related shrinkage of the sensor matrix results in a decrease in the resistivity of the condition sensor. Correlation of measured sensor resistivity with data from aged specimens allows indirect determination of mechanical damage and remaining age of the composite component.

Wiener-matrix image restoration beyond the sampling passband

NASA Technical Reports Server (NTRS)

Rahman, Zia-Ur; Alter-Gartenberg, Rachel; Fales, Carl L.; Huck, Friedrich O.

1991-01-01

A finer-than-sampling-lattice resolution image can be obtained using multiresponse image gathering and Wiener-matrix restoration. The multiresponse image gathering weighs the within-passband and aliased signal components differently, allowing the Wiener-matrix restoration filter to unscramble these signal components and restore spatial frequencies beyond the sampling passband of the photodetector array. A multiresponse images can be reassembled into a single minimum mean square error image with a resolution that is sq rt A times finer than the photodetector-array sampling lattice.

Multi-allelic haplotype model based on genetic partition for genomic prediction and variance component estimation using SNP markers.

PubMed

Da, Yang

2015-12-18

The amount of functional genomic information has been growing rapidly but remains largely unused in genomic selection. Genomic prediction and estimation using haplotypes in genome regions with functional elements such as all genes of the genome can be an approach to integrate functional and structural genomic information for genomic selection. Towards this goal, this article develops a new haplotype approach for genomic prediction and estimation. A multi-allelic haplotype model treating each haplotype as an 'allele' was developed for genomic prediction and estimation based on the partition of a multi-allelic genotypic value into additive and dominance values. Each additive value is expressed as a function of h - 1 additive effects, where h = number of alleles or haplotypes, and each dominance value is expressed as a function of h(h - 1)/2 dominance effects. For a sample of q individuals, the limit number of effects is 2q - 1 for additive effects and is the number of heterozygous genotypes for dominance effects. Additive values are factorized as a product between the additive model matrix and the h - 1 additive effects, and dominance values are factorized as a product between the dominance model matrix and the h(h - 1)/2 dominance effects. Genomic additive relationship matrix is defined as a function of the haplotype model matrix for additive effects, and genomic dominance relationship matrix is defined as a function of the haplotype model matrix for dominance effects. Based on these results, a mixed model implementation for genomic prediction and variance component estimation that jointly use haplotypes and single markers is established, including two computing strategies for genomic prediction and variance component estimation with identical results. The multi-allelic genetic partition fills a theoretical gap in genetic partition by providing general formulations for partitioning multi-allelic genotypic values and provides a haplotype method based on the quantitative genetics model towards the utilization of functional and structural genomic information for genomic prediction and estimation.

A Noise Removal Method for Uniform Circular Arrays in Complex Underwater Noise Environments with Low SNR

PubMed Central

Xia, Huijun; Yang, Kunde; Ma, Yuanliang; Wang, Yong; Liu, Yaxiong

2017-01-01

Generally, many beamforming methods are derived under the assumption of white noise. In practice, the actual underwater ambient noise is complex. As a result, the noise removal capacity of the beamforming method may be deteriorated considerably. Furthermore, in underwater environment with extremely low signal-to-noise ratio (SNR), the performances of the beamforming method may be deteriorated. To tackle these problems, a noise removal method for uniform circular array (UCA) is proposed to remove the received noise and improve the SNR in complex noise environments with low SNR. First, the symmetrical noise sources are defined and the spatial correlation of the symmetrical noise sources is calculated. Then, based on the preceding results, the noise covariance matrix is decomposed into symmetrical and asymmetrical components. Analysis indicates that the symmetrical component only affect the real part of the noise covariance matrix. Consequently, the delay-and-sum (DAS) beamforming is performed by using the imaginary part of the covariance matrix to remove the symmetrical component. However, the noise removal method causes two problems. First, the proposed method produces a false target. Second, the proposed method would seriously suppress the signal when it is located in some directions. To solve the first problem, two methods to reconstruct the signal covariance matrix are presented: based on the estimation of signal variance and based on the constrained optimization algorithm. To solve the second problem, we can design the array configuration and select the suitable working frequency. Theoretical analysis and experimental results are included to demonstrate that the proposed methods are particularly effective in complex noise environments with low SNR. The proposed method can be extended to any array. PMID:28598386

Polymer, metal and ceramic matrix composites for advanced aircraft engine applications

NASA Technical Reports Server (NTRS)

Mcdanels, D. L.; Serafini, T. T.; Dicarlo, J. A.

1985-01-01

Advanced aircraft engine research within NASA Lewis is being focused on propulsion systems for subsonic, supersonic, and hypersonic aircraft. Each of these flight regimes requires different types of engines, but all require advanced materials to meet their goals of performance, thrust-to-weight ratio, and fuel efficiency. The high strength/weight and stiffness/weight properties of resin, metal, and ceramic matrix composites will play an increasingly key role in meeting these performance requirements. At NASA Lewis, research is ongoing to apply graphite/polyimide composites to engine components and to develop polymer matrices with higher operating temperature capabilities. Metal matrix composites, using magnesium, aluminum, titanium, and superalloy matrices, are being developed for application to static and rotating engine components, as well as for space applications, over a broad temperature range. Ceramic matrix composites are also being examined to increase the toughness and reliability of ceramics for application to high-temperature engine structures and components.

Generalization of the Jones vector-matrix method and the regularity of the Weigert effect for partially polarized light.

PubMed

Kilosanidze, Barbara

2010-06-01

Generalization of the Jones vector for partially polarized radiation carried out by Kakichashvili is given. Partially polarized light is presented as two noncoherent components of mutually orthogonal polarization. The formal operation of amplitude summation of mutually noncoherent components and the symbol of this operation are introduced. The rules of operating with this symbol are determined. The regularity of the Weigert effect is modified for partial polarization of the inducing light. On this basis the modification of the Jones matrix for partially polarized light is made. The rules for the formation of the resulting matrix from the Jones matrices corresponding to the noncoherent components of partially polarized light are determined.

Social cognition in schizophrenia: cognitive and affective factors.

PubMed

Ziv, Ido; Leiser, David; Levine, Joseph

2011-01-01

Social cognition refers to how people conceive, perceive, and draw inferences about mental and emotional states of others in the social world. Previous studies suggest that the concept of social cognition involves several abilities, including those related to affect and cognition. The present study analyses the deficits of individuals with schizophrenia in two areas of social cognition: Theory of Mind (ToM) and emotion recognition and processing. Examining the impairment of these abilities in patients with schizophrenia has the potential to elucidate the neurophysiological regions involved in social cognition and may also have the potential to aid rehabilitation. Two experiments were conducted. Both included the same five tasks: first- and second-level false-belief ToM tasks, emotion inferencing, understanding of irony, and matrix reasoning (a WAIS-R subtest). The matrix reasoning task was administered to evaluate and control for the association of the other tasks with analytic reasoning skills. Experiment 1 involved factor analysis of the task performance of 75 healthy participants. Experiment 2 compared 30 patients with schizophrenia to an equal number of matched controls. Results. (1) The five tasks were clearly divided into two factors corresponding to the two areas of social cognition, ToM and emotion recognition and processing. (2) Schizophrenics' performance was impaired on all tasks, particularly on those loading heavily on the analytic component (matrix reasoning and second-order ToM). (3) Matrix reasoning, second-level ToM (ToM2), and irony were found to distinguish patients from controls, even when all other tasks that revealed significant impairment in the patients' performance were taken into account. The two areas of social cognition examined are related to distinct factors. The mechanism for answering ToM questions (especially ToM2) depends on analytic reasoning capabilities, but the difficulties they present to individuals with schizophrenia are due to other components as well. The impairment in social cognition in schizophrenia stems from deficiencies in several mechanisms, including the ability to think analytically and to process emotion information and cues.

The Molecular Basis of Memory

PubMed Central

2012-01-01

We propose a tripartite biochemical mechanism for memory. Three physiologic components are involved, namely, the neuron (individual and circuit), the surrounding neural extracellular matrix, and the various trace metals distributed within the matrix. The binding of a metal cation affects a corresponding nanostructure (shrinking, twisting, expansion) and dielectric sensibility of the chelating node (address) within the matrix lattice, sensed by the neuron. The neural extracellular matrix serves as an electro-elastic lattice, wherein neurons manipulate multiple trace metals (n > 10) to encode, store, and decode coginive information. The proposed mechanism explains brains low energy requirements and high rates of storage capacity described in multiples of Avogadro number (NA = 6 × 1023). Supportive evidence correlates memory loss to trace metal toxicity or deficiency, or breakdown in the delivery/transport of metals to the matrix, or its degradation. Inherited diseases revolving around dysfunctional trace metal metabolism and memory dysfunction, include Alzheimer's disease (Al, Zn, Fe), Wilson’s disease (Cu), thalassemia (Fe), and autism (metallothionein). The tripartite mechanism points to the electro-elastic interactions of neurons with trace metals distributed within the neural extracellular matrix, as the molecular underpinning of “synaptic plasticity” affecting short-term memory, long-term memory, and forgetting. PMID:23050060

Grapevine tissues and phenology differentially affect soluble carbohydrates determination by capillary electrophoresis.

PubMed

Moreno, Daniela; Berli, Federico; Bottini, Rubén; Piccoli, Patricia N; Silva, María F

2017-09-01

Soluble carbohydrates distribution depends on plant physiology and, among other important factors, determines fruit yield and quality. In plant biology, the analysis of sugars is useful for many purposes, including metabolic studies. Capillary electrophoresis (CE) proved to be a powerful green separation technique with minimal sample preparation, even in complex plant tissues, that can provide high-resolution efficiency. Matrix effect refers to alterations in the analytical response caused by components of a sample other than the analyte of interest. Thus, the assessment and reduction of the matrix factor is fundamental for metabolic studies in different matrices. The present study evaluated the source and levels of matrix effects in the determination of most abundant sugars in grapevine tissues (mature and young leaves, berries and roots) at two phenological growth stages. Sucrose was the sugar that showed the least matrix effects, while fructose was the most affected analyte. Based on plant tissues, young leaves presented the smaller matrix effects, irrespectively of the phenology. These changes may be attributed to considerable differences at chemical composition of grapevine tissues with plant development. Therefore, matrix effect should be an important concern for plant metabolomics. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Cellulose biosynthesis by the beta-proteobacterium, Chromobacterium violaceum.

PubMed

Recouvreux, Derce O S; Carminatti, Claudimir A; Pitlovanciv, Ana K; Rambo, Carlos R; Porto, Luismar M; Antônio, Regina V

2008-11-01

The Chromobacterium violaceum ATCC 12472 genome was sequenced by The Brazilian National Genome Project Consortium. Previous annotation reported the presence of cellulose biosynthesis genes in that genome. Analysis of these genes showed that, as observed in other bacteria, they are organized in two operons. In the present work, experimental evidences of the presence of cellulose in the extracellular matrix of the biofilm produced by C. violaceum in static cultures are shown. Biofilm samples were enzymatically digested by cellulase, releasing glucose units, suggesting the presence of cellulose as an extracellular matrix component. Fluorescence microscopy observations showed that C. violaceum produces a cellulase-sensitive extracellular matrix composed of fibers able to bind calcofluor. C. violaceum grows on medium containing Congo red, forming brown-red colonies. Together, these results suggest that cellulase-susceptible matrix material is cellulose. Scanning electronic microscopy analysis showed that the extracellular matrix exhibited a network of microfibrils, typical of bacterial cellulose. Although cellulose production is widely distributed between several bacterial species, including at least the groups of Gram-negative proteobacteria alpha and gamma, we give for the first time experimental evidence for cellulose production in beta-proteobacteria.

Program For Analysis Of Metal-Matrix Composites

NASA Technical Reports Server (NTRS)

Murthy, P. L. N.; Mital, S. K.

1994-01-01

METCAN (METal matrix Composite ANalyzer) is computer program used to simulate computationally nonlinear behavior of high-temperature metal-matrix composite structural components in specific applications, providing comprehensive analyses of thermal and mechanical performances. Written in FORTRAN 77.

Application of Wave Distribution Function Method to the ERG/PWE Data

NASA Astrophysics Data System (ADS)

Ota, M.; Kasahara, Y.; Matsuda, S.; Kojima, H.; Matsuoka, A.; Hikishima, M.; Kasaba, Y.; Ozaki, M.; Yagitani, S.; Tsuchiya, F.; Kumamoto, A.

2017-12-01

The ERG (Arase) satellite was launched on 20 December 2016 to study acceleration and loss mechanisms of relativistic electrons in the Earth's magnetosphere. The Plasma Wave Experiment (PWE), which is one of the science instruments on board the ERG satellite, measures electric field and magnetic field. The PWE consists of three sub-systems; EFD (Electric Field Detector), OFA/WFC (Onboard Frequency Analyzer and Waveform Capture), and HFA (High Frequency Analyzer).The OFA/WFC measures electromagnetic field spectra and raw waveforms in the frequency range from few Hz to 20 kHz. The OFA produces three kind of data; OFA-SPEC (power spectrum), OFA-MATRIX (spectral matrix), and OFA-COMPLEX (complex spectrum). The OFA-MATRIX measures ensemble averaged complex cross-spectra of two electric field components, and of three magnetic field components. The OFA-COMPLEX measures instantaneous complex spectra of electric and magnetic fields. These data are produced every 8 seconds in the nominal mode, and it can be used for polarization analysis and wave propagation direction finding.In general, spectral matrix composed by cross-spectra of observed signals is used for direction finding, and many algorithms have been proposed. For example, Means method and SVD method can be applied on the assumption that the spectral matrix is consists of a single plane wave, while wave distribution function (WDF) method is applicable even to the data in which multiple numbers of plane waves are simultaneously included. In this presentation, we introduce the results when the WDF method is applied to the ERG/PWE data.

Genetic Relationships Between Chondrules, Rims and Matrix

NASA Technical Reports Server (NTRS)

Huss, G. R.; Alexander, C. M. OD.; Palme, H.; Bland, P. A.; Wasson, J. T.

2004-01-01

The most primitive chondrites are composed of chondrules and chondrule fragments, various types of inclusions, discrete mineral grains, metal, sulfides, and fine-grained materials that occur as interchondrule matrix and as chondrule/inclusion rims. Understanding how these components are related is essential for understanding how chondrites and their constituents formed and were processed in the solar nebula. For example, were the first generations of chondrules formed by melting of matrix or matrix precursors? Did chondrule formation result in appreciable transfer of chondrule material into the matrix? Here, we consider three types of data: 1) compositional data for bulk chondrites and matrix, 2) mineralogical and textural information, and 3) the abundances and characteristics of presolar materials that reside in the matrix and rims. We use these data to evaluate the roles of evaporation and condensation, chondrule formation, mixing of different nebular components, and secondary processing both in the nebula and on the parent bodies. Our goal is to identify the things that are reasonably well established and to point out the areas that need additional work.

Morphology of LDPE-poly(3-hydroxybutyrate) films

NASA Astrophysics Data System (ADS)

Ol'khov, A. A.; Vlasov, S. V.; Shibryaeva, L. S.; Kosenko, R. Yu.; Iordanskii, A. L.

2012-07-01

The structure and morphology of biodegradable extruded polymeric films based on LDPE and (PHB) were studied by a combination of methods including polarization IR spectroscopy, DSC, and scanning electron microscopy (SEM). The components of LDPE-PHB blends containing 1-32% PHB are immiscible and form morphological structures (phases) with well distinguishable phase boundaries between dispersed phase and dispersion matrix.

Relative Contribution of Matrix Structure, Patch Resources and Management to the Local Densities of Two Large Blue Butterfly Species

PubMed Central

Skórka, Piotr; Nowicki, Piotr; Bonk, Maciej; Król, Wiesław; Szpiłyk, Damian; Woyciechowski, Michal

2016-01-01

The type of matrix, the landscape surrounding habitat patches, may determine the distribution and function of local populations. However, the matrix is often heterogeneous, and its various components may differentially contribute to metapopulation processes at different spatial scales, a phenomenon that has rarely been investigated. The aim of this study was to estimate the relative importance of matrix composition and spatial scale, habitat quality, and management intensity on the occurrence and density of local populations of two endangered large blue butterflies: Phengaris teleius and P. nausithous. Presence and abundance data were assessed over two years, 2011–12, in 100 local patches within two heterogeneous regions (near Kraków and Tarnów, southern Poland). The matrix composition was analyzed at eight spatial scales. We observed high occupancy rates in both species, regions and years. With the exception of area and isolation, almost all of the matrix components contributed to Phengaris sp. densities. The different matrix components acted at different spatial scales (grassland cover within 4 and 3 km, field cover within 0.4 and 0.3 km and water cover within 4 km radii for P. teleius and P. nausithous, respectively) and provided the highest independent contribution to the butterfly densities. Additionally, the effects of a 0.4 km radius of forest cover and a food plant cover on P. teleius, and a 1 km radius of settlement cover and management intensity on P. nausithous densities were observed. Contrary to former studies we conclude that the matrix heterogeneity and spatial scale rather than general matrix type are of relevance for densities of butterflies. Conservation strategies for these umbrella species should concentrate on maintaining habitat quality and managing matrix composition at the most appropriate spatial scales. PMID:28005942

Relative Contribution of Matrix Structure, Patch Resources and Management to the Local Densities of Two Large Blue Butterfly Species.

PubMed

Kajzer-Bonk, Joanna; Skórka, Piotr; Nowicki, Piotr; Bonk, Maciej; Król, Wiesław; Szpiłyk, Damian; Woyciechowski, Michal

2016-01-01

The type of matrix, the landscape surrounding habitat patches, may determine the distribution and function of local populations. However, the matrix is often heterogeneous, and its various components may differentially contribute to metapopulation processes at different spatial scales, a phenomenon that has rarely been investigated. The aim of this study was to estimate the relative importance of matrix composition and spatial scale, habitat quality, and management intensity on the occurrence and density of local populations of two endangered large blue butterflies: Phengaris teleius and P. nausithous. Presence and abundance data were assessed over two years, 2011-12, in 100 local patches within two heterogeneous regions (near Kraków and Tarnów, southern Poland). The matrix composition was analyzed at eight spatial scales. We observed high occupancy rates in both species, regions and years. With the exception of area and isolation, almost all of the matrix components contributed to Phengaris sp. densities. The different matrix components acted at different spatial scales (grassland cover within 4 and 3 km, field cover within 0.4 and 0.3 km and water cover within 4 km radii for P. teleius and P. nausithous, respectively) and provided the highest independent contribution to the butterfly densities. Additionally, the effects of a 0.4 km radius of forest cover and a food plant cover on P. teleius, and a 1 km radius of settlement cover and management intensity on P. nausithous densities were observed. Contrary to former studies we conclude that the matrix heterogeneity and spatial scale rather than general matrix type are of relevance for densities of butterflies. Conservation strategies for these umbrella species should concentrate on maintaining habitat quality and managing matrix composition at the most appropriate spatial scales.

Metal-matrix composites: Status and prospects

NASA Technical Reports Server (NTRS)

1974-01-01

Applications of metal matrix composites for air frames and jet engine components are discussed. The current state of the art in primary and secondary fabrication is presented. The present and projected costs were analyzed to determine the cost effectiveness of metal matrix composites. The various types of metal matrix composites and their characteristics are described.

An introduction of component fusion extend Kalman filtering method

NASA Astrophysics Data System (ADS)

Geng, Yue; Lei, Xusheng

2018-05-01

In this paper, the Component Fusion Extend Kalman Filtering (CFEKF) algorithm is proposed. Assuming each component of error propagation are independent with Gaussian distribution. The CFEKF can be obtained through the maximum likelihood of propagation error, which can adjust the state transition matrix and the measured matrix adaptively. With minimize linearization error, CFEKF can an effectively improve the estimation accuracy of nonlinear system state. The computation of CFEKF is similar to EKF which is easy for application.

Research on graphite reinforced glass matrix composites

NASA Technical Reports Server (NTRS)

Prewo, K. M.; Thompson, E. R.

1980-01-01

High levels of mechanical performance in tension, flexure, fatigue, and creep loading situations of graphite fiber reinforced glass matrix composites are discussed. At test temperatures of up to 813 K it was found that the major limiting factor was the oxidative instability of the reinforcing graphite fibers. Particular points to note include the following: (1) a wide variety of graphite fibers were found to be comparable with the glass matrix composite fabrication process; (2) choice of fiber, to a large extent, controlled resultant composite performance; (3) composite fatigue performance was found to be excellent at both 300 K and 703 K; (4) composite creep and stress rupture at temperatures of up to 813 K was limited by the oxidative stability of the fiber; (5) exceptionally low values of composite thermal expansion coefficient were attributable to the dimensional stability of both matrix and fiber; and (6) component fabricability was demonstrated through the hot pressing of hot sections and brazing using glass and metal joining phases.

Matrix Metalloproteinases in Non-Neoplastic Disorders

PubMed Central

Tokito, Akinori; Jougasaki, Michihisa

2016-01-01

The matrix metalloproteinases (MMPs) are zinc-dependent endopeptidases belonging to the metzincin superfamily. There are at least 23 members of MMPs ever reported in human, and they and their substrates are widely expressed in many tissues. Recent growing evidence has established that MMP not only can degrade a variety of components of extracellular matrix, but also can cleave and activate various non-matrix proteins, including cytokines, chemokines and growth factors, contributing to both physiological and pathological processes. In normal conditions, MMP expression and activity are tightly regulated via interactions between their activators and inhibitors. Imbalance among these factors, however, results in dysregulated MMP activity, which causes tissue destruction and functional alteration or local inflammation, leading to the development of diverse diseases, such as cardiovascular disease, arthritis, neurodegenerative disease, as well as cancer. This article focuses on the accumulated evidence supporting a wide range of roles of MMPs in various non-neoplastic diseases and provides an outlook on the therapeutic potential of inhibiting MMP action. PMID:27455234

Thermal expansion of composites: Methods and results. [large space structures

NASA Technical Reports Server (NTRS)

Bowles, D. E.; Tenney, D. R.

1981-01-01

The factors controlling the dimensional stability of various components of large space structures were investigated. Cyclic, thermal and mechanical loading were identified as the primary controlling factors of the dimensional stability of cables. For organic matrix composites, such as graphite-epoxy, it was found that these factors include moisture desorption in the space environment, thermal expansion as the structure moves from the sunlight to shadow in its orbit, mechanical loading, and microyielding of the material caused by microcracking of the matrix material. The major focus was placed on the thermal expansion of composites and in particular the development and testing of a method for its measurement.

Matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs): Positive and negative regulators in tumor cell adhesion.

PubMed

Bourboulia, Dimitra; Stetler-Stevenson, William G

2010-06-01

Cells adhere to one another and/or to matrices that surround them. Regulation of cell-cell (intercellular) and cell-matrix adhesion is tightly controlled in normal cells, however, defects in cell adhesion are common in the majority of human cancers. Multilateral communication among tumor cells with the extracellular matrix (ECM) and neighbor cells is accomplished through adhesion molecules, ECM components, proteolytic enzymes and their endogenous inhibitors. There is sufficient evidence to suggest that reduced adherence is a tumor cell property engaged during tumor progression. Tumor cells acquire the ability to change shape, detach and easily move through spaces disorganizing the normal tissue architecture. This property is due to changes in expression levels of adhesion molecules and/or due to elevated levels of secreted proteolytic enzymes, including matrix metalloproteinases (MMPs). Among other roles, MMPs degrade the ECM and, therefore, prepare the path for tumor cells to migrate, invade and spread to distant secondary areas, where they form metastasis. Tissue inhibitors of metalloproteinases or TIMPs control MMP activities and, therefore, minimize matrix degradation. Both MMPs and TIMPs are involved in tissue remodeling and decisively regulate tumor cell progression including tumor angiogenesis. In this review, we describe and discuss data that support the important role of MMPs and TIMPs in cancer cell adhesion and tumor progression. Published by Elsevier Ltd.

Optical Spectroscopy of New Materials

NASA Technical Reports Server (NTRS)

White, Susan M.; Arnold, James O. (Technical Monitor)

1993-01-01

Composites are currently used for a rapidly expanding number of applications including aircraft structures, rocket nozzles, thermal protection of spacecraft, high performance ablative surfaces, sports equipment including skis, tennis rackets and bicycles, lightweight automobile components, cutting tools, and optical-grade mirrors. Composites are formed from two or more insoluble materials to produce a material with superior properties to either component. Composites range from dispersion-hardened alloys to advanced fiber-reinforced composites. UV/VIS and FTIR spectroscopy currently is used to evaluate the bonding between the matrix and the fibers, monitor the curing process of a polymer, measure surface contamination, characterize the interphase material, monitor anion transport in polymer phases, characterize the void formation (voids must be minimized because, like cracks in a bulk material, they lead to failure), characterize the surface of the fiber component, and measure the overall optical properties for energy balances.

Accurate and efficient modeling of the detector response in small animal multi-head PET systems.

PubMed

Cecchetti, Matteo; Moehrs, Sascha; Belcari, Nicola; Del Guerra, Alberto

2013-10-07

In fully three-dimensional PET imaging, iterative image reconstruction techniques usually outperform analytical algorithms in terms of image quality provided that an appropriate system model is used. In this study we concentrate on the calculation of an accurate system model for the YAP-(S)PET II small animal scanner, with the aim to obtain fully resolution- and contrast-recovered images at low levels of image roughness. For this purpose we calculate the system model by decomposing it into a product of five matrices: (1) a detector response component obtained via Monte Carlo simulations, (2) a geometric component which describes the scanner geometry and which is calculated via a multi-ray method, (3) a detector normalization component derived from the acquisition of a planar source, (4) a photon attenuation component calculated from x-ray computed tomography data, and finally, (5) a positron range component is formally included. This system model factorization allows the optimization of each component in terms of computation time, storage requirements and accuracy. The main contribution of this work is a new, efficient way to calculate the detector response component for rotating, planar detectors, that consists of a GEANT4 based simulation of a subset of lines of flight (LOFs) for a single detector head whereas the missing LOFs are obtained by using intrinsic detector symmetries. Additionally, we introduce and analyze a probability threshold for matrix elements of the detector component to optimize the trade-off between the matrix size in terms of non-zero elements and the resulting quality of the reconstructed images. In order to evaluate our proposed system model we reconstructed various images of objects, acquired according to the NEMA NU 4-2008 standard, and we compared them to the images reconstructed with two other system models: a model that does not include any detector response component and a model that approximates analytically the depth of interaction as detector response component. The comparisons confirm previous research results, showing that the usage of an accurate system model with a realistic detector response leads to reconstructed images with better resolution and contrast recovery at low levels of image roughness.

Accurate and efficient modeling of the detector response in small animal multi-head PET systems

NASA Astrophysics Data System (ADS)

Cecchetti, Matteo; Moehrs, Sascha; Belcari, Nicola; Del Guerra, Alberto

2013-10-01

In fully three-dimensional PET imaging, iterative image reconstruction techniques usually outperform analytical algorithms in terms of image quality provided that an appropriate system model is used. In this study we concentrate on the calculation of an accurate system model for the YAP-(S)PET II small animal scanner, with the aim to obtain fully resolution- and contrast-recovered images at low levels of image roughness. For this purpose we calculate the system model by decomposing it into a product of five matrices: (1) a detector response component obtained via Monte Carlo simulations, (2) a geometric component which describes the scanner geometry and which is calculated via a multi-ray method, (3) a detector normalization component derived from the acquisition of a planar source, (4) a photon attenuation component calculated from x-ray computed tomography data, and finally, (5) a positron range component is formally included. This system model factorization allows the optimization of each component in terms of computation time, storage requirements and accuracy. The main contribution of this work is a new, efficient way to calculate the detector response component for rotating, planar detectors, that consists of a GEANT4 based simulation of a subset of lines of flight (LOFs) for a single detector head whereas the missing LOFs are obtained by using intrinsic detector symmetries. Additionally, we introduce and analyze a probability threshold for matrix elements of the detector component to optimize the trade-off between the matrix size in terms of non-zero elements and the resulting quality of the reconstructed images. In order to evaluate our proposed system model we reconstructed various images of objects, acquired according to the NEMA NU 4-2008 standard, and we compared them to the images reconstructed with two other system models: a model that does not include any detector response component and a model that approximates analytically the depth of interaction as detector response component. The comparisons confirm previous research results, showing that the usage of an accurate system model with a realistic detector response leads to reconstructed images with better resolution and contrast recovery at low levels of image roughness.

Multi-spectrometer calibration transfer based on independent component analysis.

PubMed

Liu, Yan; Xu, Hao; Xia, Zhenzhen; Gong, Zhiyong

2018-02-26

Calibration transfer is indispensable for practical applications of near infrared (NIR) spectroscopy due to the need for precise and consistent measurements across different spectrometers. In this work, a method for multi-spectrometer calibration transfer is described based on independent component analysis (ICA). A spectral matrix is first obtained by aligning the spectra measured on different spectrometers. Then, by using independent component analysis, the aligned spectral matrix is decomposed into the mixing matrix and the independent components of different spectrometers. These differing measurements between spectrometers can then be standardized by correcting the coefficients within the independent components. Two NIR datasets of corn and edible oil samples measured with three and four spectrometers, respectively, were used to test the reliability of this method. The results of both datasets reveal that spectra measurements across different spectrometers can be transferred simultaneously and that the partial least squares (PLS) models built with the measurements on one spectrometer can predict that the spectra can be transferred correctly on another.

Aerospace Ceramic Materials: Thermal, Environmental Barrier Coatings and SiC/SiC Ceramic Matrix Composites for Turbine Engine Applications

NASA Technical Reports Server (NTRS)

Zhu, Dongming

2018-01-01

Ceramic materials play increasingly important roles in aerospace applications because ceramics have unique properties, including high temperature capability, high stiffness and strengths, excellent oxidation and corrosion resistance. Ceramic materials also generally have lower densities as compared to metallic materials, making them excellent candidates for light-weight hot-section components of aircraft turbine engines, rocket exhaust nozzles, and thermal protection systems for space vehicles when they are being used for high-temperature and ultra-high temperature ceramics applications. Ceramic matrix composites (CMCs), including non-oxide and oxide CMCs, are also recently being incorporated in gas turbine engines for high pressure and high temperature section components and exhaust nozzles. However, the complexity and variability of aerospace ceramic processing methods, compositions and microstructures, the relatively low fracture toughness of the ceramic materials, still remain the challenging factors for ceramic component design, validation, life prediction, and thus broader applications. This ceramic material section paper presents an overview of aerospace ceramic materials and their characteristics. A particular emphasis has been placed on high technology level (TRL) enabling ceramic systems, that is, turbine engine thermal and environmental barrier coating systems and non-oxide type SiC/SiC CMCs. The current status and future trend of thermal and environmental barrier coatings and SiC/SiC CMC development and applications are described.

On the additive and dominant variance and covariance of individuals within the genomic selection scope.

PubMed

Vitezica, Zulma G; Varona, Luis; Legarra, Andres

2013-12-01

Genomic evaluation models can fit additive and dominant SNP effects. Under quantitative genetics theory, additive or "breeding" values of individuals are generated by substitution effects, which involve both "biological" additive and dominant effects of the markers. Dominance deviations include only a portion of the biological dominant effects of the markers. Additive variance includes variation due to the additive and dominant effects of the markers. We describe a matrix of dominant genomic relationships across individuals, D, which is similar to the G matrix used in genomic best linear unbiased prediction. This matrix can be used in a mixed-model context for genomic evaluations or to estimate dominant and additive variances in the population. From the "genotypic" value of individuals, an alternative parameterization defines additive and dominance as the parts attributable to the additive and dominant effect of the markers. This approach underestimates the additive genetic variance and overestimates the dominance variance. Transforming the variances from one model into the other is trivial if the distribution of allelic frequencies is known. We illustrate these results with mouse data (four traits, 1884 mice, and 10,946 markers) and simulated data (2100 individuals and 10,000 markers). Variance components were estimated correctly in the model, considering breeding values and dominance deviations. For the model considering genotypic values, the inclusion of dominant effects biased the estimate of additive variance. Genomic models were more accurate for the estimation of variance components than their pedigree-based counterparts.

Tracing and separating plasma components causing matrix effects in hydrophilic interaction chromatography-electrospray ionization mass spectrometry.

PubMed

Ekdahl, Anja; Johansson, Maria C; Ahnoff, Martin

2013-04-01

Matrix effects on electrospray ionization were investigated for plasma samples analysed by hydrophilic interaction chromatography (HILIC) in gradient elution mode, and HILIC columns of different chemistries were tested for separation of plasma components and model analytes. By combining mass spectral data with post-column infusion traces, the following components of protein-precipitated plasma were identified and found to have significant effect on ionization: urea, creatinine, phosphocholine, lysophosphocholine, sphingomyelin, sodium ion, chloride ion, choline and proline betaine. The observed effect on ionization was both matrix-component and analyte dependent. The separation of identified plasma components and model analytes on eight columns was compared, using pair-wise linear correlation analysis and principal component analysis (PCA). Large changes in selectivity could be obtained by change of column, while smaller changes were seen when the mobile phase buffer was changed from ammonium formate pH 3.0 to ammonium acetate pH 4.5. While results from PCA and linear correlation analysis were largely in accord, linear correlation analysis was judged to be more straight-forward in terms of conduction and interpretation.

Randomized subspace-based robust principal component analysis for hyperspectral anomaly detection

NASA Astrophysics Data System (ADS)

Sun, Weiwei; Yang, Gang; Li, Jialin; Zhang, Dianfa

2018-01-01

A randomized subspace-based robust principal component analysis (RSRPCA) method for anomaly detection in hyperspectral imagery (HSI) is proposed. The RSRPCA combines advantages of randomized column subspace and robust principal component analysis (RPCA). It assumes that the background has low-rank properties, and the anomalies are sparse and do not lie in the column subspace of the background. First, RSRPCA implements random sampling to sketch the original HSI dataset from columns and to construct a randomized column subspace of the background. Structured random projections are also adopted to sketch the HSI dataset from rows. Sketching from columns and rows could greatly reduce the computational requirements of RSRPCA. Second, the RSRPCA adopts the columnwise RPCA (CWRPCA) to eliminate negative effects of sampled anomaly pixels and that purifies the previous randomized column subspace by removing sampled anomaly columns. The CWRPCA decomposes the submatrix of the HSI data into a low-rank matrix (i.e., background component), a noisy matrix (i.e., noise component), and a sparse anomaly matrix (i.e., anomaly component) with only a small proportion of nonzero columns. The algorithm of inexact augmented Lagrange multiplier is utilized to optimize the CWRPCA problem and estimate the sparse matrix. Nonzero columns of the sparse anomaly matrix point to sampled anomaly columns in the submatrix. Third, all the pixels are projected onto the complemental subspace of the purified randomized column subspace of the background and the anomaly pixels in the original HSI data are finally exactly located. Several experiments on three real hyperspectral images are carefully designed to investigate the detection performance of RSRPCA, and the results are compared with four state-of-the-art methods. Experimental results show that the proposed RSRPCA outperforms four comparison methods both in detection performance and in computational time.

Background recovery via motion-based robust principal component analysis with matrix factorization

NASA Astrophysics Data System (ADS)

Pan, Peng; Wang, Yongli; Zhou, Mingyuan; Sun, Zhipeng; He, Guoping

2018-03-01

Background recovery is a key technique in video analysis, but it still suffers from many challenges, such as camouflage, lighting changes, and diverse types of image noise. Robust principal component analysis (RPCA), which aims to recover a low-rank matrix and a sparse matrix, is a general framework for background recovery. The nuclear norm is widely used as a convex surrogate for the rank function in RPCA, which requires computing the singular value decomposition (SVD), a task that is increasingly costly as matrix sizes and ranks increase. However, matrix factorization greatly reduces the dimension of the matrix for which the SVD must be computed. Motion information has been shown to improve low-rank matrix recovery in RPCA, but this method still finds it difficult to handle original video data sets because of its batch-mode formulation and implementation. Hence, in this paper, we propose a motion-assisted RPCA model with matrix factorization (FM-RPCA) for background recovery. Moreover, an efficient linear alternating direction method of multipliers with a matrix factorization (FL-ADM) algorithm is designed for solving the proposed FM-RPCA model. Experimental results illustrate that the method provides stable results and is more efficient than the current state-of-the-art algorithms.

Lax representations for matrix short pulse equations

NASA Astrophysics Data System (ADS)

Popowicz, Z.

2017-10-01

The Lax representation for different matrix generalizations of Short Pulse Equations (SPEs) is considered. The four-dimensional Lax representations of four-component Matsuno, Feng, and Dimakis-Müller-Hoissen-Matsuno equations are obtained. The four-component Feng system is defined by generalization of the two-dimensional Lax representation to the four-component case. This system reduces to the original Feng equation, to the two-component Matsuno equation, or to the Yao-Zang equation. The three-component version of the Feng equation is presented. The four-component version of the Matsuno equation with its Lax representation is given. This equation reduces the new two-component Feng system. The two-component Dimakis-Müller-Hoissen-Matsuno equations are generalized to the four-parameter family of the four-component SPE. The bi-Hamiltonian structure of this generalization, for special values of parameters, is defined. This four-component SPE in special cases reduces to the new two-component SPE.

Development and Property Evaluation of Selected HfO2-Silicon and Rare Earth-Silicon Based Bond Coats and Environmental Barrier Coating Systems for SiC/SiC Ceramic Matrix Composites

NASA Technical Reports Server (NTRS)

Zhu, Dongming

2016-01-01

Ceramic environmental barrier coatings (EBC) and SiC/SiC ceramic matrix composites (CMCs) will play a crucial role in future aircraft propulsion systems because of their ability to significantly increase engine operating temperatures, improve component durability, reduce engine weight and cooling requirements. Advanced EBC systems for SiC/SiC CMC turbine and combustor hot section components are currently being developed to meet future turbine engine emission and performance goals. One of the significant material development challenges for the high temperature CMC components is to develop prime-reliant, high strength and high temperature capable environmental barrier coating bond coat systems, since the current silicon bond coat cannot meet the advanced EBC-CMC temperature and stability requirements. In this paper, advanced NASA HfO2-Si and rare earth Si based EBC bond coat EBC systems for SiC/SiC CMC combustor and turbine airfoil applications are investigated. High temperature properties of the advanced EBC systems, including the strength, fracture toughness, creep and oxidation resistance have been studied and summarized. The advanced NASA EBC systems showed some promise to achieve 1500C temperature capability, helping enable next generation turbine engines with significantly improved engine component temperature capability and durability.

Accumulation of worn-out GBM material substantially contributes to mesangial matrix expansion in diabetic nephropathy.

PubMed

Kriz, Wilhelm; Löwen, Jana; Federico, Giuseppina; van den Born, Jacob; Gröne, Elisabeth; Gröne, Hermann Josef

2017-06-01

Thickening of the glomerular basement membrane (GBM) and expansion of the mesangial matrix are hallmarks of diabetic nephropathy (DN), generally considered to emerge from different sites of overproduction: GBM components from podocytes and mesangial matrix from mesangial cells. Reevaluation of 918 biopsies with DN revealed strong evidence that these mechanisms are connected to each other, wherein excess GBM components fail to undergo degradation and are deposited in the mesangium. These data do not exclude that mesangial cells also synthesize components that contribute to the accumulation of matrix in the mesangium. Light, electron microscopic, immunofluorescence, and in situ hybridization studies clearly show that the thickening of the GBM is due not only to overproduction of components of the mature GBM (α3 and α5 chains of collagen IV and agrin) by podocytes but also to resumed increased synthesis of the α1 chain of collagen IV and of perlecan by endothelial cells usually seen during embryonic development. We hypothesize that these abnormal production mechanisms are caused by different processes: overproduction of mature GBM-components by the diabetic milieu and regression of endothelial cells to an embryonic production mode by decreased availability of mediators from podocytes. Copyright © 2017 the American Physiological Society.

In Spite of Indeterminacy Many Common Factor Score Estimates Yield an Identical Reproduced Covariance Matrix

ERIC Educational Resources Information Center

Beauducel, Andre

2007-01-01

It was investigated whether commonly used factor score estimates lead to the same reproduced covariance matrix of observed variables. This was achieved by means of Schonemann and Steiger's (1976) regression component analysis, since it is possible to compute the reproduced covariance matrices of the regression components corresponding to different…

A Fully Non-metallic Gas Turbine Engine Enabled by Additive Manufacturing

NASA Technical Reports Server (NTRS)

Grady, Joseph E.

2014-01-01

The Non-Metallic Gas Turbine Engine project, funded by NASA Aeronautics Research Institute (NARI), represents the first comprehensive evaluation of emerging materials and manufacturing technologies that will enable fully nonmetallic gas turbine engines. This will be achieved by assessing the feasibility of using additive manufacturing technologies for fabricating polymer matrix composite (PMC) and ceramic matrix composite (CMC) gas turbine engine components. The benefits of the proposed effort include: 50 weight reduction compared to metallic parts, reduced manufacturing costs due to less machining and no tooling requirements, reduced part count due to net shape single component fabrication, and rapid design change and production iterations. Two high payoff metallic components have been identified for replacement with PMCs and will be fabricated using fused deposition modeling (FDM) with high temperature capable polymer filaments. The first component is an acoustic panel treatment with a honeycomb structure with an integrated back sheet and perforated front sheet. The second component is a compressor inlet guide vane. The CMC effort, which is starting at a lower technology readiness level, will use a binder jet process to fabricate silicon carbide test coupons and demonstration articles. The polymer and ceramic additive manufacturing efforts will advance from monolithic materials toward silicon carbide and carbon fiber reinforced composites for improved properties. Microstructural analysis and mechanical testing will be conducted on the PMC and CMC materials. System studies will assess the benefits of fully nonmetallic gas turbine engine in terms of fuel burn, emissions, reduction of part count, and cost. The proposed effort will be focused on a small 7000 lbf gas turbine engine. However, the concepts are equally applicable to large gas turbine engines. The proposed effort includes a multidisciplinary, multiorganization NASA - industry team that includes experts in ceramic materials and CMCs, polymers and PMCs, structural engineering, additive manufacturing, engine design and analysis, and system analysis.

Modifying Matrix Materials to Increase Wetting and Adhesion

NASA Technical Reports Server (NTRS)

Zhong, Katie

2011-01-01

In an alternative approach to increasing the degrees of wetting and adhesion between the fiber and matrix components of organic-fiber/polymer matrix composite materials, the matrix resins are modified. Heretofore, it has been common practice to modify the fibers rather than the matrices: The fibers are modified by chemical and/or physical surface treatments prior to combining the fibers with matrix resins - an approach that entails considerable expense and usually results in degradation (typically, weakening) of fibers. The alternative approach of modifying the matrix resins does not entail degradation of fibers, and affords opportunities for improving the mechanical properties of the fiber composites. The alternative approach is more cost-effective, not only because it eliminates expensive fiber-surface treatments but also because it does not entail changes in procedures for manufacturing conventional composite-material structures. The alternative approach is best described by citing an example of its application to a composite of ultra-high-molecular- weight polyethylene (UHMWPE) fibers in an epoxy matrix. The epoxy matrix was modified to a chemically reactive, polarized epoxy nano-matrix to increase the degrees of wetting and adhesion between the fibers and the matrix. The modification was effected by incorporating a small proportion (0.3 weight percent) of reactive graphitic nanofibers produced from functionalized nanofibers into the epoxy matrix resin prior to combining the resin with the UHMWPE fibers. The resulting increase in fiber/matrix adhesion manifested itself in several test results, notably including an increase of 25 percent in the maximum fiber pullout force and an increase of 60-65 percent in fiber pullout energy. In addition, it was conjectured that the functionalized nanofibers became involved in the cross linking reaction of the epoxy resin, with resultant enhancement of the mechanical properties and lower viscosity of the matrix.

Proteins and saccharides of the sea urchin organic matrix of mineralization: characterization and localization in the spine skeleton.

PubMed

Ameye, L; De Becker, G; Killian, C; Wilt, F; Kemps, R; Kuypers, S; Dubois, P

2001-04-01

Properties of the echinoderm skeleton are under biological control, which is exerted in part by the organic matrix embedded in the mineralized part of the skeleton. This organic matrix consists of proteins and glycoproteins whose carbohydrate component is specifically involved in the control mechanisms. The saccharide moiety of the organic matrix of the spines of the echinoid Paracentrotus lividus was characterized using enzyme-linked lectin assays (ELLAs). O-glycoproteins, different types of complex N-glycoproteins, and terminal sialic acids were detected. Sialic acids are known to interact with Ca ions and could play an important role in the mineralization process. Some of the carbohydrate components detected by ELLAs as well as two organic matrix proteins (SM30 and SM50) were localized within different subregions of the spine skeleton using field-emission scanning electron microscopy. The mappings show that some of these components are not homogeneously distributed in the different skeletal subregions. For example, some N-glycoproteins were preferentially located in the putative amorphous subregion of the skeleton, whereas some O-glycoproteins were localized in the subregion where skeletal growth is inhibited. These results suggest that the biological control exerted on the skeletal properties can be partly modulated by local differences in the organic matrix composition. Copyright 2001 Academic Press.

Second rank direction cosine spherical tensor operators and the nuclear electric quadrupole hyperfine structure Hamiltonian of rotating molecules

NASA Astrophysics Data System (ADS)

di Lauro, C.

2018-03-01

Transformations of vector or tensor properties from a space-fixed to a molecule-fixed axis system are often required in the study of rotating molecules. Spherical components λμ,ν of a first rank irreducible tensor can be obtained from the direction cosines between the two axis systems, and a second rank tensor with spherical components λμ,ν(2) can be built from the direct product λ × λ. It is shown that the treatment of the interaction between molecular rotation and the electric quadrupole of a nucleus is greatly simplified, if the coefficients in the axis-system transformation of the gradient of the electric field of the outer charges at the coupled nucleus are arranged as spherical components λμ,ν(2). Then the reduced matrix elements of the field gradient operators in a symmetric top eigenfunction basis, including their dependence on the molecule-fixed z-angular momentum component k, can be determined from the knowledge of those of λ(2) . The hyperfine structure Hamiltonian Hq is expressed as the sum of terms characterized each by a value of the molecule-fixed index ν, whose matrix elements obey the rule Δk = ν. Some of these terms may vanish because of molecular symmetry, and the specific cases of linear and symmetric top molecules, orthorhombic molecules, and molecules with symmetry lower than orthorhombic are considered. Each ν-term consists of a contraction of the rotational tensor λ(2) and the nuclear quadrupole tensor in the space-fixed frame, and its matrix elements in the rotation-nuclear spin coupled representation can be determined by the standard spherical tensor methods.

Quantitative characterization of the carbon/carbon composites components based on video of polarized light microscope.

PubMed

Li, Yixian; Qi, Lehua; Song, Yongshan; Chao, Xujiang

2017-06-01

The components of carbon/carbon (C/C) composites have significant influence on the thermal and mechanical properties, so a quantitative characterization of component is necessary to study the microstructure of C/C composites, and further to improve the macroscopic properties of C/C composites. Considering the extinction crosses of the pyrocarbon matrix have significant moving features, the polarized light microscope (PLM) video is used to characterize C/C composites quantitatively because it contains sufficiently dynamic and structure information. Then the optical flow method is introduced to compute the optical flow field between the adjacent frames, and segment the components of C/C composites from PLM image by image processing. Meanwhile the matrix with different textures is re-segmented by the length difference of motion vectors, and then the component fraction of each component and extinction angle of pyrocarbon matrix are calculated directly. Finally, the C/C composites are successfully characterized from three aspects of carbon fiber, pyrocarbon, and pores by a series of image processing operators based on PLM video, and the errors of component fractions are less than 15%. © 2017 Wiley Periodicals, Inc.

Characteristics of global organic matrix in normal and pimpled chicken eggshells.

PubMed

Liu, Z; Song, L; Zhang, F; He, W; Linhardt, R J

2017-10-01

The organic matrix from normal and pimpled calcified chicken eggshells were dissociated into acid-insoluble, water-insoluble, and facultative-soluble (both acid- and water-soluble) components, to understand the influence of shell matrix on eggshell qualities. A linear correlation was shown among these 3 matrix components in normal eggshells but was not observed in pimpled eggshells. In pimpled eggshells, the percentage contents of all 4 groups of matrix (the total matrix, acid-insoluble matrix, water-insoluble matrix, and facultative-soluble matrix) were significantly higher than that in normal eggshells. The amounts of both total matrix and acid-insoluble matrix in individual pimpled calcified shells were high, even though their weight was much lower than a normal eggshell. In both normal and pimpled eggshells, the calcified eggshell weight and shell thickness significantly and positively correlated with the amounts of all 4 groups of matrix in an individual calcified shell. In normal eggshells, the calcified shell thickness and shell breaking strength showed no significant correlations with the percentage contents of all 4 groups of matrix. In normal eggshells, only the shell membrane weight significantly correlated with the constituent ratios of both acid-insoluble matrix and facultative-soluble matrix in the whole matrix. In pimpled eggshells, 3 variables (calcified shell weight, shell thickness, and breaking strength) were significantly correlated with the constituent proportions of both acid-insoluble matrix and facultative-matrix. This study suggests that mechanical properties of normal eggshells may not linearly depend on the organic matrix content in the calcified eggshells and that pimpled eggshells might result by the disequilibrium enrichment of some proteins with negative effects. © 2017 Poultry Science Association Inc.

Dynamic Forms. Part 1: Functions

NASA Technical Reports Server (NTRS)

Meyer, George; Smith, G. Allan

1993-01-01

The formalism of dynamic forms is developed as a means for organizing and systematizing the design control systems. The formalism allows the designer to easily compute derivatives to various orders of large composite functions that occur in flight-control design. Such functions involve many function-of-a-function calls that may be nested to many levels. The component functions may be multiaxis, nonlinear, and they may include rotation transformations. A dynamic form is defined as a variable together with its time derivatives up to some fixed but arbitrary order. The variable may be a scalar, a vector, a matrix, a direction cosine matrix, Euler angles, or Euler parameters. Algorithms for standard elementary functions and operations of scalar dynamic forms are developed first. Then vector and matrix operations and transformations between parameterization of rotations are developed in the next level in the hierarchy. Commonly occurring algorithms in control-system design, including inversion of pure feedback systems, are developed in the third level. A large-angle, three-axis attitude servo and other examples are included to illustrate the effectiveness of the developed formalism. All algorithms were implemented in FORTRAN code. Practical experience shows that the proposed formalism may significantly improve the productivity of the design and coding process.

A Candida Biofilm-Induced Pathway for Matrix Glucan Delivery: Implications for Drug Resistance

PubMed Central

Taff, Heather T.; Nett, Jeniel E.; Zarnowski, Robert; Ross, Kelly M.; Sanchez, Hiram; Cain, Mike T.; Hamaker, Jessica; Mitchell, Aaron P.; Andes, David R.

2012-01-01

Extracellular polysaccharides are key constituents of the biofilm matrix of many microorganisms. One critical carbohydrate component of Candida albicans biofilms, β-1,3 glucan, has been linked to biofilm protection from antifungal agents. In this study, we identify three glucan modification enzymes that function to deliver glucan from the cell to the extracellular matrix. These enzymes include two predicted glucan transferases and an exo-glucanase, encoded by BGL2, PHR1, and XOG1, respectively. We show that the enzymes are crucial for both delivery of β-1,3 glucan to the biofilm matrix and for accumulation of mature matrix biomass. The enzymes do not appear to impact cell wall glucan content of biofilm cells, nor are they necessary for filamentation or biofilm formation. We demonstrate that mutants lacking these genes exhibit enhanced susceptibility to the commonly used antifungal, fluconazole, during biofilm growth only. Transcriptional analysis and biofilm phenotypes of strains with multiple mutations suggest that these enzymes act in a complementary fashion to distribute matrix downstream of the primary β-1,3 glucan synthase encoded by FKS1. Furthermore, our observations suggest that this matrix delivery pathway works independently from the C. albicans ZAP1 matrix formation regulatory pathway. These glucan modification enzymes appear to play a biofilm-specific role in mediating the delivery and organization of mature biofilm matrix. We propose that the discovery of inhibitors for these enzymes would provide promising anti-biofilm therapeutics. PMID:22876186

The local matrix distribution and the functional development of tissue engineered cartilage, a finite element study.

PubMed

Sengers, B G; Van Donkelaar, C C; Oomens, C W J; Baaijens, F P T

2004-12-01

Assessment of the functionality of tissue engineered cartilage constructs is hampered by the lack of correlation between global measurements of extra cellular matrix constituents and the global mechanical properties. Based on patterns of matrix deposition around individual cells, it has been hypothesized previously, that mechanical functionality arises when contact occurs between zones of matrix associated with individual cells. The objective of this study is to determine whether the local distribution of newly synthesized extracellular matrix components contributes to the evolution of the mechanical properties of tissue engineered cartilage constructs. A computational homogenization approach was adopted, based on the concept of a periodic representative volume element. Local transport and immobilization of newly synthesized matrix components were described. Mechanical properties were taken dependent on the local matrix concentration and subsequently the global aggregate modulus and hydraulic permeability were derived. The transport parameters were varied to assess the effect of the evolving matrix distribution during culture. The results indicate that the overall stiffness and permeability are to a large extent insensitive to differences in local matrix distribution. This emphasizes the need for caution in the visual interpretation of tissue functionality from histology and underlines the importance of complementary measurements of the matrix's intrinsic molecular organization.

Rotordynamic analysis using the Complex Transfer Matrix: An application to elastomer supports using the viscoelastic correspondence principle

NASA Astrophysics Data System (ADS)

Varney, Philip; Green, Itzhak

2014-11-01

Numerous methods are available to calculate rotordynamic whirl frequencies, including analytic methods, finite element analysis, and the transfer matrix method. The typical real-valued transfer matrix (RTM) suffers from several deficiencies, including lengthy computation times and the inability to distinguish forward and backward whirl. Though application of complex coordinates in rotordynamic analysis is not novel per se, specific advantages gained from using such coordinates in a transfer matrix analysis have yet to be elucidated. The present work employs a complex coordinate redefinition of the transfer matrix to obtain reduced forms of the elemental transfer matrices in inertial and rotating reference frames, including external stiffness and damping. Application of the complex-valued state variable redefinition results in a reduction of the 8×8 RTM to the 4×4 Complex Transfer Matrix (CTM). The CTM is advantageous in that it intrinsically separates forward and backward whirl, eases symbolic manipulation by halving the transfer matrices’ dimension, and provides significant improvement in computation time. A symbolic analysis is performed on a simple overhung rotor to demonstrate the mathematical motivation for whirl frequency separation. The CTM's utility is further shown by analyzing a rotordynamic system supported by viscoelastic elastomer rings. Viscoelastic elastomer ring supports can provide significant damping while reducing the cost and complexity associated with conventional components such as squeeze film dampers. The stiffness and damping of a viscoelastic damper ring are determined herein as a function of whirl frequency using the viscoelastic correspondence principle and a constitutive fractional calculus viscoelasticity model. The CTM is then employed to obtain the characteristic equation, where the whirl frequency dependent stiffness and damping of the elastomer supports are included. The Campbell diagram is shown, demonstrating the CTM's ability to intrinsically separate synchronous whirl direction for a non-trivial rotordynamic system. Good agreement is found between the CTM results and previously obtained analytic and experimental results for the elastomer ring supported rotordynamic system.

[Fluorescence excitation-emission matrix spectroscopy of CDOM from Yundang Lagoon and its indication for organic pollution].

PubMed

Zhuo, Jian-Fu; Guo, Wei-Dong; Deng, Xun; Zhang, Zhi-Ying; Xu, Jing; Huang, Ling-Feng

2010-06-01

Fluorescence excitation-emission matrix spectroscopy (EEMs) combined with absorption spectroscopy were applied to study the optical properties of CDOM samples from highly-polluted Yundang Lagoon in Xiamen in order to demonstrate the feasibility of using these spectral properties as a tracer of the degree of organic pollution in similar polluted coastal waters. Surface water samples were collected from 13 stations 4 times during April and May, 2008. Parallel factor analysis (PARAFAC) model was used to resolve the EEMs of CDOM. Five separate fluorescent components were identified, including two humic-like components (C1: 240, 325/422 nm; C5: 260, 380/474 nm), two protein-like components (C2: 225, 275/350 nm; C4: 240, 300/354 nm) and one xenobiotic-like component (C3: 225/342 nm), which could be used as a good tracer for the input of the anthropogenic organic, pollutants. The concentrations of component C3 and dissolved organic carbon (DOC) are much higher near the inlet of sewage discharge, demonstrating that the discharge of surrounding sewage is a major source of organic pollutants in Yundang Lagoon. CDOM absorption coefficient alpha (280) and the score of humic-like component C1 showed significant linear relationships with COD(Mn), and a strong positive correlation was also found between the score of protein-like component C2 and BOD5. This suggested that the optical properties of CDOM may provide a fast in-situ way to monitor the variation of the water quality in Yundang Lagoon and that of similar polluted coastal waters.

Racial Differences in the Extracellular Matrix and Histone Acetylation of the Lamina Cribrosa and Peripapillary Sclera.

PubMed

Park, Hae-Young Lopilly; Kim, Jie Hyun; Jung, Younhea; Park, Chan Kee

2017-08-01

We investigated the extracellular matrix (ECM) of the lamina cribrosa (LC) and peripapillary sclera (PPS) and compared histone acetylation and related enzymes to identify racial differences between Korean and Caucasian donor eyes. Posterior segment tissues were obtained from 30 Caucasian donors and 42 age and axial length-matched Korean donors. Histone modification was assessed for histone deacetylase (HDAC) 2, HDAC3, and acetylated histone H3. The promoter regions of the major ECM in the LC and PPS including collagen type I and III, and elastic fiber components (elastin and fibrillin-1) and lysyl oxidase enzymes including lysyl oxidase-like 1 and 2 (LOXL2) were evaluated by chromatin immunoprecipitation (ChIP) assay. Protein and mRNA expression of major ECM components were assessed using real-time polymerase chain reaction analysis, western blot analysis, and immunohistochemical staining. HDAC2 and HDAC3 expression levels were decreased and acetylated histone H3 was increased in the LC and PPS of Korean eyes than Caucasian eyes. The promoter regions of LOXL2, elastin, and fribrillin-1 genes were highly acetylated in Korean LC. Expression of LOXL2 and elastic fiber components (elastin and fibrillin-1) were significantly increased in Korean LC and PPS than Caucasians according to the real-time polymerase chain reaction, western blot analyses, and quantification of elastic fiber staining. Histone acetylation status differed in the promoter regions of the elastic fiber components and LOXL2 in the LC and PPS according to race. Further study to reveal the association with these findings to the pathogenesis of glaucoma in Korean eyes is needed.

Tissue Engineering Using Transfected Growth-Factor Genes

NASA Technical Reports Server (NTRS)

Madry, Henning; Langer, Robert S.; Freed, Lisa E.; Trippel, Stephen; Vunjak-Novakovic, Gordana

2005-01-01

A method of growing bioengineered tissues includes, as a major component, the use of mammalian cells that have been transfected with genes for secretion of regulator and growth-factor substances. In a typical application, one either seeds the cells onto an artificial matrix made of a synthetic or natural biocompatible material, or else one cultures the cells until they secrete a desired amount of an extracellular matrix. If such a bioengineered tissue construct is to be used for surgical replacement of injured tissue, then the cells should preferably be the patient s own cells or, if not, at least cells matched to the patient s cells according to a human-leucocyteantigen (HLA) test. The bioengineered tissue construct is typically implanted in the patient's injured natural tissue, wherein the growth-factor genes enhance metabolic functions that promote the in vitro development of functional tissue constructs and their integration with native tissues. If the matrix is biodegradable, then one of the results of metabolism could be absorption of the matrix and replacement of the matrix with tissue formed at least partly by the transfected cells. The method was developed for articular chondrocytes but can (at least in principle) be extended to a variety of cell types and biocompatible matrix materials, including ones that have been exploited in prior tissue-engineering methods. Examples of cell types include chondrocytes, hepatocytes, islet cells, nerve cells, muscle cells, other organ cells, bone- and cartilage-forming cells, epithelial and endothelial cells, connective- tissue stem cells, mesodermal stem cells, and cells of the liver and the pancreas. Cells can be obtained from cell-line cultures, biopsies, and tissue banks. Genes, molecules, or nucleic acids that secrete factors that influence the growth of cells, the production of extracellular matrix material, and other cell functions can be inserted in cells by any of a variety of standard transfection techniques.

Improved Joining of Metal Components to Composite Structures

NASA Technical Reports Server (NTRS)

Semmes, Edmund

2009-01-01

Systems requirements for complex spacecraft drive design requirements that lead to structures, components, and/or enclosures of a multi-material and multifunctional design. The varying physical properties of aluminum, tungsten, Invar, or other high-grade aerospace metals when utilized in conjunction with lightweight composites multiply system level solutions. These multi-material designs are largely dependent upon effective joining techAn improved method of joining metal components to matrix/fiber composite material structures has been invented. The method is particularly applicable to equipping such thin-wall polymer-matrix composite (PMC) structures as tanks with flanges, ceramic matrix composite (CMC) liners for high heat engine nozzles, and other metallic-to-composite attachments. The method is oriented toward new architectures and distributing mechanical loads as widely as possible in the vicinities of attachment locations to prevent excessive concentrations of stresses that could give rise to delaminations, debonds, leaks, and other failures. The method in its most basic form can be summarized as follows: A metal component is to be joined to a designated attachment area on a composite-material structure. In preparation for joining, the metal component is fabricated to include multiple studs projecting from the aforementioned face. Also in preparation for joining, holes just wide enough to accept the studs are molded into, drilled, or otherwise formed in the corresponding locations in the designated attachment area of the uncured ("wet') composite structure. The metal component is brought together with the uncured composite structure so that the studs become firmly seated in the holes, thereby causing the composite material to become intertwined with the metal component in the joining area. Alternately, it is proposed to utilize other mechanical attachment schemes whereby the uncured composite and metallic parts are joined with "z-direction" fasteners. The resulting "wet" assembly is then subjected to the composite-curing heat treatment, becoming a unitary structure. It should be noted that this new art will require different techniques for CMC s versus PMC's, but the final architecture and companion curing philosophy is the same. For instance, a chemical vapor infiltration (CVI) fabrication technique may require special integration of the pre-form and

How fast will trees die? A transition matrix model of ash decline in forest stands infested by emerald ash borer

Treesearch

Kathleen S. Knight; Robert P. Long; Joanne Rebbeck; Annemarie Smith; Kamal Gandhi; Daniel A. Herms

2008-01-01

We recorded Fraxinus spp. tree health and other forest stand characteristics for 68 plots in 21 EAB-infested forest stands in Michigan and Ohio in 2005 and 2007. Fraxinus spp. were a dominant component of these stands, with more than 900 ash trees (including Fraxinus americana, Fraxinus pennsylvanica, Fraxinus profunda...

Reduction of interferences in the analysis of Children's Dimetapp using ultraviolet spectroscopy data and target factor analysis

NASA Astrophysics Data System (ADS)

Msimanga, Huggins Z.; Lam, Truong Thach Ho; Latinwo, Nathaniel; Song, Mihyang Kristy; Tavakoli, Newsha

2018-03-01

A calibration matrix has been developed and successfully applied to quantify actives in Children's Dimetapp®, a cough mixture whose active components suffer from heavy spectral interference. High-performance liquid chromatography/photodiode array instrument was used to identify the actives and any other UV-detectable excipients that might contribute to interferences. The instrument was also used to obtain reference data on the actives, instead of relying on the manufacturer's claims. Principal component analysis was used during the developmental stages of the calibration matrix to highlight any mismatch between the calibration and sample spectra, making certain that "apples" were not compared with "oranges". The prediction model was finally calculated using target factor analysis and partial least squares regression. In addition to the actives in Children's Dimetapp® (brompheniramine maleate, phenylephrine hydrogen chloride, and dextromethorphan hydrogen bromide), sodium benzoate was identified as the major and FD&C Blue #1, FD&C Red #40, and methyl anthranilate as minor spectral interferences. Model predictions were compared before and after the interferences were included into the calibration matrix. Before including interferences, the following results were obtained: brompheniramine maleate = 481.3 mg L- 1 ± 134% RE; phenylephrine hydrogen chloride = 1041 mg L- 1 ± 107% RE; dextromethorphan hydrogen bromide = 1571 mg L- 1 ± 107% RE, where % RE = percent relative error based on the reference HPLC data. After including interferences, the results were as follows: brompheniramine maleate = 196.3 mg L- 1 ± 4.4% RE; phenylephrine hydrogen chloride = 501.3 mg L- 1 ± 0.10% RE; dextromethorphan hydrogen bromide = 998.7 mg L- 1 ± 1.6% RE as detailed in Table 6.

On the multivariate total least-squares approach to empirical coordinate transformations. Three algorithms

NASA Astrophysics Data System (ADS)

Schaffrin, Burkhard; Felus, Yaron A.

2008-06-01

The multivariate total least-squares (MTLS) approach aims at estimating a matrix of parameters, Ξ, from a linear model ( Y- E Y = ( X- E X ) · Ξ) that includes an observation matrix, Y, another observation matrix, X, and matrices of randomly distributed errors, E Y and E X . Two special cases of the MTLS approach include the standard multivariate least-squares approach where only the observation matrix, Y, is perturbed by random errors and, on the other hand, the data least-squares approach where only the coefficient matrix X is affected by random errors. In a previous contribution, the authors derived an iterative algorithm to solve the MTLS problem by using the nonlinear Euler-Lagrange conditions. In this contribution, new lemmas are developed to analyze the iterative algorithm, modify it, and compare it with a new ‘closed form’ solution that is based on the singular-value decomposition. For an application, the total least-squares approach is used to estimate the affine transformation parameters that convert cadastral data from the old to the new Israeli datum. Technical aspects of this approach, such as scaling the data and fixing the columns in the coefficient matrix are investigated. This case study illuminates the issue of “symmetry” in the treatment of two sets of coordinates for identical point fields, a topic that had already been emphasized by Teunissen (1989, Festschrift to Torben Krarup, Geodetic Institute Bull no. 58, Copenhagen, Denmark, pp 335-342). The differences between the standard least-squares and the TLS approach are analyzed in terms of the estimated variance component and a first-order approximation of the dispersion matrix of the estimated parameters.

A texture-component Avrami model for predicting recrystallization textures, kinetics and grain size

NASA Astrophysics Data System (ADS)

Raabe, Dierk

2007-03-01

The study presents an analytical model for predicting crystallographic textures and the final grain size during primary static recrystallization of metals using texture components. The kinetics is formulated as a matrix variant of the Johnson-Mehl-Avrami-Kolmogorov equation. The matrix form is required since the kinetic and crystallographic evolution of the microstructure is described in terms of a limited set of growing (recrystallizing) and swept (deformed) texture components. The number of components required (5-10) defines the order of the matrix since the kinetic coupling occurs between all recrystallizing and all deformed components. Each such couple is characterized by corresponding values for the nucleation energy and grain boundary mobility. The values of these parameters can be obtained by analytical or numerical coarse graining according to a renormalization scheme which replaces many individual grains which grow via recrystallization in a deformed texture component by a single equivalent recrystallization texture component or by fitting to experimental data. Each deformed component is further characterized by an average stored deformation energy. Each element of the kinetic matrix, reflecting one of the possible couplings between a deformed and a recrystallizing texture component, is then derived in each time step by a set of two differential equations. The first equation describes the thermally activated nucleation and growth processes for the expanded (free) volume for a particular couple of a deformed and a recrystallizing texture component and the second equation is used for calculating the constrained (real) volume for that couple which corrects the free volume for those portions of the deformation component which were already swept. The new method is particularly developed for the fast and physically based process simulation of recrystallization textures with respect to processing. The present paper introduces the method and applies it to the primary recrystallization of low carbon steels.

Optical implementation of systolic array processing

NASA Technical Reports Server (NTRS)

Caulfield, H. J.; Rhodes, W. T.; Foster, M. J.; Horvitz, S.

1981-01-01

Algorithms for matrix vector multiplication are implemented using acousto-optic cells for multiplication and input data transfer and using charge coupled devices detector arrays for accumulation and output of the results. No two dimensional matrix mask is required; matrix changes are implemented electronically. A system for multiplying a 50 component nonnegative real vector by a 50 by 50 nonnegative real matrix is described. Modifications for bipolar real and complex valued processing are possible, as are extensions to matrix-matrix multiplication and multiplication of a vector by multiple matrices.

The method of trend analysis of parameters time series of gas-turbine engine state

NASA Astrophysics Data System (ADS)

Hvozdeva, I.; Myrhorod, V.; Derenh, Y.

2017-10-01

This research substantiates an approach to interval estimation of time series trend component. The well-known methods of spectral and trend analysis are used for multidimensional data arrays. The interval estimation of trend component is proposed for the time series whose autocorrelation matrix possesses a prevailing eigenvalue. The properties of time series autocorrelation matrix are identified.

Effects of Ethanol on Brain Extracellular Matrix: Implications for Alcohol Use Disorder

PubMed Central

Lasek, Amy W.

2016-01-01

The brain extracellular matrix (ECM) occupies the space between cells and is involved in cell-matrix and cell-cell adhesion. However, in addition to providing structural support to brain tissue, the ECM activates cell signaling and controls synaptic transmission. The expression and activity of brain ECM components are regulated by alcohol exposure. This review will discuss what is currently known about the effects of alcohol on the activity and expression of brain ECM components. An interpretation of how these changes might promote alcohol use disorder (AUD) will be also provided. Ethanol exposure decreases levels of structural proteins involved in the interstitial matrix and basement membrane, with a concomitant increase in proteolytic enzymes that degrade these components. In contrast, ethanol exposure generally increases perineuronal net (PN) components. Because the ECM has been shown to regulate both synaptic plasticity and behavioral responses to drugs of abuse, regulation of the brain ECM by alcohol may be relevant to the development of alcoholism. Although investigation of the function of brain ECM in alcohol abuse is still in early stages, a greater understanding of the interplay between ECM and alcohol might lead to novel therapeutic strategies for treating AUD. PMID:27581478

Extracellular matrix components in breast cancer progression and metastasis.

PubMed

Oskarsson, Thordur

2013-08-01

The extracellular matrix (ECM) is composed of highly variable and dynamic components that regulate cell behavior. The protein composition and physical properties of the ECM govern cell fate through biochemical and biomechanical mechanisms. This requires a carefully orchestrated and thorough regulation considering that a disturbed ECM can have serious consequences and lead to pathological conditions like cancer. In breast cancer, many ECM proteins are significantly deregulated and specific matrix components promote tumor progression and metastatic spread. Intriguingly, several ECM proteins that are associated with breast cancer development, overlap substantially with a group of ECM proteins induced during the state of tissue remodeling such as mammary gland involution. Fibrillar collagens, fibronectin, hyaluronan and matricellular proteins are matrix components that are common to both involution and cancer. Moreover, some of these proteins have in recent years been identified as important constituents of metastatic niches in breast cancer. In addition, specific ECM molecules, their receptors or enzymatic modifiers are significantly involved in resistance to therapeutic intervention. Further analysis of these ECM proteins and the downstream ECM mediated signaling pathways may provide a range of possibilities to identify druggable targets against advanced breast cancer. Copyright © 2013 Elsevier Ltd. All rights reserved.

Methods for the visualization and analysis of extracellular matrix protein structure and degradation.

PubMed

Leonard, Annemarie K; Loughran, Elizabeth A; Klymenko, Yuliya; Liu, Yueying; Kim, Oleg; Asem, Marwa; McAbee, Kevin; Ravosa, Matthew J; Stack, M Sharon

2018-01-01

This chapter highlights methods for visualization and analysis of extracellular matrix (ECM) proteins, with particular emphasis on collagen type I, the most abundant protein in mammals. Protocols described range from advanced imaging of complex in vivo matrices to simple biochemical analysis of individual ECM proteins. The first section of this chapter describes common methods to image ECM components and includes protocols for second harmonic generation, scanning electron microscopy, and several histological methods of ECM localization and degradation analysis, including immunohistochemistry, Trichrome staining, and in situ zymography. The second section of this chapter details both a common transwell invasion assay and a novel live imaging method to investigate cellular behavior with respect to collagen and other ECM proteins of interest. The final section consists of common electrophoresis-based biochemical methods that are used in analysis of ECM proteins. Use of the methods described herein will enable researchers to gain a greater understanding of the role of ECM structure and degradation in development and matrix-related diseases such as cancer and connective tissue disorders. © 2018 Elsevier Inc. All rights reserved.

Greater Severity of Peanut Challenge Reactions Using a High fat versus Low Fat Matrix Vehicle.

PubMed

Pettersson, M Eleonore; Koppelman, Gerard H; Schins, Afke M M; van Ginkel, C Doriene; Flokstra-de Blok, Bertine M J; Kollen, Boudewijn J; Dubois, Anthony E J

2018-06-16

Food allergy is a potentially life-threatening disease with a detrimental effect on the quality of life of caregivers and children.(1) Although many different types of food have been identified as potential elicitors of allergic reactions, only a small number of these foods cause the majority of reactions.(2) Food consists of a complex mixture of nutrient and non-nutrient components and their molecular interactions, which are known as the food matrix. Individual matrix components, or the matrix as a whole, may interact with a food allergen and may influence the clinical response to that allergen. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

The role of rapid solidification processing in the fabrication of fiber reinforced metal matrix composites

NASA Technical Reports Server (NTRS)

Locci, Ivan E.; Noebe, Ronald D.

1989-01-01

Advanced composite processing techniques for fiber reinforced metal matrix composites require the flexibility to meet several widespread objectives. The development of uniquely desired matrix microstructures and uniformly arrayed fiber spacing with sufficient bonding between fiber and matrix to transmit load between them without degradation to the fiber or matrix are the minimum requirements necessary of any fabrication process. For most applications these criteria can be met by fabricating composite monotapes which are then consolidated into composite panels or more complicated components such as fiber reinforced turbine blades. Regardless of the end component, composite monotapes are the building blocks from which near net shape composite structures can be formed. The most common methods for forming composite monotapes are the powder cloth, foil/fiber, plasma spray, and arc spray processes. These practices, however, employ rapid solidification techniques in processing of the composite matrix phase. Consequently, rapid solidification processes play a vital and yet generally overlooked role in composite fabrication. The future potential of rapid solidification processing is discussed.

Insights into the key roles of epigenetics in matrix macromolecules-associated wound healing.

PubMed

Piperigkou, Zoi; Götte, Martin; Theocharis, Achilleas D; Karamanos, Nikos K

2017-10-24

Extracellular matrix (ECM) is a dynamic network of macromolecules, playing a regulatory role in cell functions, tissue regeneration and remodeling. Wound healing is a tissue repair process necessary for the maintenance of the functionality of tissues and organs. This highly orchestrated process is divided into four temporally overlapping phases, including hemostasis, inflammation, proliferation and tissue remodeling. The dynamic interplay between ECM and resident cells exerts its critical role in many aspects of wound healing, including cell proliferation, migration, differentiation, survival, matrix degradation and biosynthesis. Several epigenetic regulatory factors, such as the endogenous non-coding microRNAs (miRNAs), are the drivers of the wound healing response. microRNAs have pivotal roles in regulating ECM composition during wound healing and dermal regeneration. Their expression is associated with the distinct phases of wound healing and they serve as target biomarkers and targets for systematic regulation of wound repair. In this article we critically present the importance of epigenetics with particular emphasis on miRNAs regulating ECM components (i.e. glycoproteins, proteoglycans and matrix proteases) that are key players in wound healing. The clinical relevance of miRNA targeting as well as the delivery strategies designed for clinical applications are also presented and discussed. Copyright © 2017 Elsevier B.V. All rights reserved.

Quantization of an electromagnetic field in two-dimensional photonic structures based on the scattering matrix formalism ( S-quantization)

NASA Astrophysics Data System (ADS)

Ivanov, K. A.; Nikolaev, V. V.; Gubaydullin, A. R.; Kaliteevski, M. A.

2017-10-01

Based on the scattering matrix formalism, we have developed a method of quantization of an electromagnetic field in two-dimensional photonic nanostructures ( S-quantization in the two-dimensional case). In this method, the fields at the boundaries of the quantization box are expanded into a Fourier series and are related with each other by the scattering matrix of the system, which is the product of matrices describing the propagation of plane waves in empty regions of the quantization box and the scattering matrix of the photonic structure (or an arbitrary inhomogeneity). The quantization condition (similarly to the onedimensional case) is formulated as follows: the eigenvalues of the scattering matrix are equal to unity, which corresponds to the fact that the set of waves that are incident on the structure (components of the expansion into the Fourier series) is equal to the set of waves that travel away from the structure (outgoing waves). The coefficients of the matrix of scattering through the inhomogeneous structure have been calculated using the following procedure: the structure is divided into parallel layers such that the permittivity in each layer varies only along the axis that is perpendicular to the layers. Using the Fourier transform, the Maxwell equations have been written in the form of a matrix that relates the Fourier components of the electric field at the boundaries of neighboring layers. The product of these matrices is the transfer matrix in the basis of the Fourier components of the electric field. Represented in a block form, it is composed by matrices that contain the reflection and transmission coefficients for the Fourier components of the field, which, in turn, constitute the scattering matrix. The developed method considerably simplifies the calculation scheme for the analysis of the behavior of the electromagnetic field in structures with a two-dimensional inhomogeneity. In addition, this method makes it possible to obviate difficulties that arise in the analysis of the Purcell effect because of the divergence of the integral describing the effective volume of the mode in open systems.

Double-Vacuum-Bag Process for Making Resin-Matrix Composites

NASA Technical Reports Server (NTRS)

Bradford, Larry J.

2007-01-01

A double-vacuum-bag process has been devised as a superior alternative to a single-vacuum-bag process used heretofore in making laminated fiber-reinforced resin-matrix composite-material structural components. This process is applicable to broad classes of high-performance matrix resins including polyimides and phenolics that emit volatile compounds (solvents and volatile by-products of resin-curing chemical reactions) during processing. The superiority of the double-vacuum-bag process lies in enhanced management of the volatile compounds. Proper management of volatiles is necessary for making composite-material components of high quality: if not removed and otherwise properly managed, volatiles can accumulate in interior pockets as resins cure, thereby forming undesired voids in the finished products. The curing cycle for manufacturing a composite laminate containing a reactive resin matrix usually consists of a two-step ramp-and-hold temperature profile and an associated single-step pressure profile as shown in Figure 1. The lower-temperature ramp-and-hold step is known in the art as the B stage. During the B stage, prepregs are heated and volatiles are generated. Because pressure is not applied at this stage, volatiles are free to escape. Pressure is applied during the higher-temperature ramp-and-hold step to consolidate the laminate and impart desired physical properties to the resin matrix. The residual volatile content and fluidity of the resin at the beginning of application of consolidation pressure are determined by the temperature and time parameters of the B stage. Once the consolidation pressure is applied, residual volatiles are locked in. In order to produce a void-free, high-quality laminate, it is necessary to design the curing cycle to obtain the required residual fluidity and the required temperature at the time of application of the consolidation pressure.

Damage and failure behavior of metal matrix composites under biaxial loads

NASA Astrophysics Data System (ADS)

Kirkpatrick, Steven Wayne

Metal matrix composites (MMCs) are being considered for increased use in structures that require the ductility and damage tolerance of the metal matrix and the enhanced strength and creep resistance at elevated temperatures of high performance fibers. Particularly promising for advanced aerospace engines and airframes are SiC fiber/titanium matrix composites (TMCs). A large program was undertaken in the Air Force to characterize the deformation and failure behaviors of TMCs and to develop computational models that can be used for component design. The effort reported here focused on a SiC SCS-6/Timetal 21S composite under biaxial loading conditions. Biaxial loading conditions are important because multiaxial stresses have been shown to influence the strength and ductility of engineering materials and, in general, structural components are subjected to multiaxial loads. The TMC material response, including stress-strain curves and failure surfaces, was measured using a combination of off-axis uniaxial tension and compression tests and biaxial cruciform tests. The off-axis tests produce combinations of in-plane tension, compression, and shear stresses, the mix of which are controlled by the relative angle between the fiber and specimen axes. The biaxial cruciform tests allowed independent control over the tensile or compressive loads in the fiber and transverse directions. The results of these characterization tests were used to develop a microstructural constitutive model and failure criteria. The basis of the micromechanical constitutive model is a representative unit volume of the MMC with a periodic array of fibers. The representative unit volume is divided into a fiber and three matrix cells for which the microstructural equilibrium and compatibility equations can be analyzed. The resulting constitutive model and associated failure criteria can be used to predict the material behavior under general loading conditions.

Neutron absorbers and methods of forming at least a portion of a neutron absorber

DOEpatents

Guillen, Donna P; Porter, Douglas L; Swank, W David; Erickson, Arnold W

2014-12-02

Methods of forming at least a portion of a neutron absorber include combining a first material and a second material to form a compound, reducing the compound into a plurality of particles, mixing the plurality of particles with a third material, and pressing the mixture of the plurality of particles and the third material. One or more components of neutron absorbers may be formed by such methods. Neutron absorbers may include a composite material including an intermetallic compound comprising hafnium aluminide and a matrix material comprising pure aluminum.

A Framework for Integrated Component and System Analyses of Instabilities

NASA Technical Reports Server (NTRS)

Ahuja, Vineet; Erwin, James; Arunajatesan, Srinivasan; Cattafesta, Lou; Liu, Fei

2010-01-01

Instabilities associated with fluid handling and operation in liquid rocket propulsion systems and test facilities usually manifest themselves as structural vibrations or some form of structural damage. While the source of the instability is directly related to the performance of a component such as a turbopump, valve or a flow control element, the associated pressure fluctuations as they propagate through the system have the potential to amplify and resonate with natural modes of the structural elements and components of the system. In this paper, the authors have developed an innovative multi-level approach that involves analysis at the component and systems level. The primary source of the unsteadiness is modeled with a high-fidelity hybrid RANS/LES based CFD methodology that has been previously used to study instabilities in feed systems. This high fidelity approach is used to quantify the instability and understand the physics associated with the instability. System response to the driving instability is determined through a transfer matrix approach wherein the incoming and outgoing pressure and velocity fluctuations are related through a transfer (or transmission) matrix. The coefficients of the transfer matrix for each component (i.e. valve, pipe, orifice etc.) are individually derived from the flow physics associated with the component. A demonstration case representing a test loop/test facility comprised of a network of elements is constructed with the transfer matrix approach and the amplification of modes analyzed as the instability propagates through the test loop.

Reliability analysis of laminated CMC components through shell subelement techniques

NASA Technical Reports Server (NTRS)

Starlinger, Alois; Duffy, Stephen F.; Gyekenyesi, John P.

1992-01-01

An updated version of the integrated design program Composite Ceramics Analysis and Reliability Evaluation of Structures (C/CARES) was developed for the reliability evaluation of ceramic matrix composites (CMC) laminated shell components. The algorithm is now split into two modules: a finite-element data interface program and a reliability evaluation algorithm. More flexibility is achieved, allowing for easy implementation with various finite-element programs. The interface program creates a neutral data base which is then read by the reliability module. This neutral data base concept allows easy data transfer between different computer systems. The new interface program from the finite-element code Matrix Automated Reduction and Coupling (MARC) also includes the option of using hybrid laminates (a combination of plies of different materials or different layups) and allows for variations in temperature fields throughout the component. In the current version of C/CARES, a subelement technique was implemented, enabling stress gradients within an element to be taken into account. The noninteractive reliability function is now evaluated at each Gaussian integration point instead of using averaging techniques. As a result of the increased number of stress evaluation points, considerable improvements in the accuracy of reliability analyses were realized.

Combined Thermomechanical and Environmental Durability of Environmental Barrier Coating Systems on SiC/SiC Ceramic Matrix Composites

NASA Technical Reports Server (NTRS)

Zhu, Dongming; Harder, Bryan; Bhatt, Ramakrishna

2016-01-01

Environmental barrier coatings (EBCs) and SiC/SiC ceramic matrix composites (CMCs) will play a crucial role in next generation turbine engines for hot-section component applications. The development of prime-reliant environmental barrier coatings is essential to the EBC-CMC system durability, ensuring the successful implementations of the high temperature and lightweight engine component technologies for engine applications.This paper will emphasize recent NASA environmental barrier coating and CMC developments for SiC/SiC turbine airfoil components, utilizing advanced coating compositions and processing methods. The emphasis has been particularly placed on thermomechanical and environment durability evaluations of EBC-CMC systems. We have also addressed the integration of the EBCs with advanced SiC/SiC CMCs, and studied the effects of combustion environments and Calcium-Magnesium-Alumino-Silicate (CMAS) deposits on the durability of the EBC-CMC systems under thermal gradient and mechanical loading conditions. Advanced environmental barrier coating systems, including multicomponent rare earth silicate EBCs and HfO2-Si based bond coats, will be discussed for the performance improvements to achieve better temperature capability and CMAS resistance for future engine operating conditions.

Implementation of polyatomic MCTDHF capability

NASA Astrophysics Data System (ADS)

Haxton, Daniel; Jones, Jeremiah; Rescigno, Thomas; McCurdy, C. William; Ibrahim, Khaled; Williams, Sam; Vecharynski, Eugene; Rouet, Francois-Henry; Li, Xiaoye; Yang, Chao

2015-05-01

The implementation of the Multiconfiguration Time-Dependent Hartree-Fock method for poly- atomic molecules using a cartesian product grid of sinc basis functions will be discussed. The focus will be on two key components of the method: first, the use of a resolution-of-the-identity approximation; sec- ond, the use of established techniques for triple Toeplitz matrix algebra using fast Fourier transform over distributed memory architectures (MPI 3D FFT). The scaling of two-electron matrix element transformations is converted from O(N4) to O(N log N) by including these components. Here N = n3, with n the number of points on a side. We test the prelim- inary implementation by calculating absorption spectra of small hydro- carbons, using approximately 16-512 points on a side. This work is supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under the Early Career program, and by the offices of BES and Advanced Scientific Computing Research, under the SciDAC program.

The assessment of source attribution of soil pollution in a typical e-waste recycling town and its surrounding regions using the combined organic and inorganic dataset.

PubMed

Luo, Jie; Qi, Shihua; Xie, Xianming; Gu, X W Sophie; Wang, Jinji

2017-01-01

Guiyu is a well-known electronic waste dismantling and recycling town in south China. Concentrations and distribution of the 21 mineral elements and 16 polycyclic aromatic hydrocarbons (PAHs) collected there were evaluated. Principal component analyses (PCA) applied to the data matrix of PAHs in the soil extracted three major factors explaining 85.7% of the total variability identified as traffic emission, coal combustion, and an unidentified source. By using metallic or metalloid element concentrations as variables, five principal components (PCs) were identified and accounted for 70.4% of the information included in the initial data matrix, which can be denoted as e-waste dismantling-related contamination, two different geological origins, anthropogenic influenced source, and marine aerosols. Combining the 21 metallic and metalloid element datasets with the 16 PAH concentrations can narrow down the coarse source and decrease the unidentified contribution to soil in the present study and therefore effectively assists the source identification process.

High-resolution measurements of the multilayer ultra-structure of articular cartilage and their translational potential

PubMed Central

2014-01-01

Current musculoskeletal imaging techniques usually target the macro-morphology of articular cartilage or use histological analysis. These techniques are able to reveal advanced osteoarthritic changes in articular cartilage but fail to give detailed information to distinguish early osteoarthritis from healthy cartilage, and this necessitates high-resolution imaging techniques measuring cells and the extracellular matrix within the multilayer structure of articular cartilage. This review provides a comprehensive exploration of the cellular components and extracellular matrix of articular cartilage as well as high-resolution imaging techniques, including magnetic resonance image, electron microscopy, confocal laser scanning microscopy, second harmonic generation microscopy, and laser scanning confocal arthroscopy, in the measurement of multilayer ultra-structures of articular cartilage. This review also provides an overview for micro-structural analysis of the main components of normal or osteoarthritic cartilage and discusses the potential and challenges associated with developing non-invasive high-resolution imaging techniques for both research and clinical diagnosis of early to late osteoarthritis. PMID:24946278

In-situ composite formation of damage tolerant coatings utilizing laser

DOEpatents

Blue, Craig A [Knoxville, TN; Wong, Frank [Livermore, CA; Aprigliano, Louis F [Berlin, MD; Engleman, Peter G [Knoxville, TN; Peter, William H [Knoxville, TN; Rozgonyi, Tibor G [Golden, CO; Ozdemir, Levent [Golden, CO

2011-05-10

A coating steel component with a pattern of an iron based matrix with crystalline particles metallurgically bound to the surface of a steel substrate for use as disc cutters or other components with one or more abrading surfaces that can experience significant abrasive wear, high point loads, and large shear stresses during use. The coated component contains a pattern of features in the shape of freckles or stripes that are laser formed and fused to the steel substrate. The features can display an inner core that is harder than the steel substrate but generally softer than the matrix surrounding the core, providing toughness and wear resistance to the features. The features result from processing an amorphous alloy where the resulting matrix can be amorphous, partially devitrified or fully devitrified.

In-situ composite formation of damage tolerant coatings utilizing laser

DOEpatents

Blue, Craig A; Wong, Frank; Aprigliano, Louis F; Engleman, Peter G; Rozgonyi, Tibor G; Ozdemir, Levent

2014-03-18

A coating steel component with a pattern of an iron based matrix with crystalline particles metallurgically bound to the surface of a steel substrate for use as disc cutters or other components with one or more abrading surfaces that can experience significant abrasive wear, high point loads, and large shear stresses during use. The coated component contains a pattern of features in the shape of freckles or stripes that are laser formed and fused to the steel substrate. The features can display an inner core that is harder than the steel substrate but generally softer than the matrix surrounding the core, providing toughness and wear resistance to the features. The features result from processing an amorphous alloy where the resulting matrix can be amorphous, partially devitrified or fully devitrified.

Bi-Component Nanostructured Arrays of Co Dots Embedded in Ni80Fe20 Antidot Matrix: Synthesis by Self-Assembling of Polystyrene Nanospheres and Magnetic Properties.

PubMed

Coïsson, Marco; Celegato, Federica; Barrera, Gabriele; Conta, Gianluca; Magni, Alessandro; Tiberto, Paola

2017-08-23

A bi-component nanostructured system composed by a Co dot array embedded in a Ni 80 Fe 20 antidot matrix has been prepared by means of the self-assembling polystyrene nanospheres lithography technique. Reference samples constituted by the sole Co dots or Ni 80 Fe 20 antidots have also been prepared, in order to compare their properties with those of the bi-component material. The coupling between the two ferromagnetic elements has been studied by means of magnetic and magneto-transport measurements. The Ni 80 Fe 20 matrix turned out to affect the vortex nucleation field of the Co dots, which in turn modifies the magneto-resistance behaviour of the system and its spinwave properties.

In-situ composite formation of damage tolerant coatings utilizing laser

DOEpatents

Blue, Craig A.; Wong, Frank; Aprigliano, Louis F.; Engleman, Peter G.; Peter, William H.; Rozgonyi, Tibor G.; Ozdemir, Levent

2016-05-24

A coating steel component with a pattern of an iron based matrix with crystalline particles metallurgically bound to the surface of a steel substrate for use as disc cutters or other components with one or more abrading surfaces that can experience significant abrasive wear, high point loads, and large shear stresses during use. The coated component contains a pattern of features in the shape of freckles or stripes that are laser formed and fused to the steel substrate. The features can display an inner core that is harder than the steel substrate but generally softer than the matrix surrounding the core, providing toughness and wear resistance to the features. The features result from processing an amorphous alloy where the resulting matrix can be amorphous, partially devitrified or fully devitrified.

Modeling the Stress Strain Behavior of Woven Ceramic Matrix Composites

NASA Technical Reports Server (NTRS)

Morscher, Gregory N.

2006-01-01

Woven SiC fiber reinforced SiC matrix composites represent one of the most mature composite systems to date. Future components fabricated out of these woven ceramic matrix composites are expected to vary in shape, curvature, architecture, and thickness. The design of future components using woven ceramic matrix composites necessitates a modeling approach that can account for these variations which are physically controlled by local constituent contents and architecture. Research over the years supported primarily by NASA Glenn Research Center has led to the development of simple mechanistic-based models that can describe the entire stress-strain curve for composite systems fabricated with chemical vapor infiltrated matrices and melt-infiltrated matrices for a wide range of constituent content and architecture. Several examples will be presented that demonstrate the approach to modeling which incorporates a thorough understanding of the stress-dependent matrix cracking properties of the composite system.

Kinetic Monte Carlo Simulations of Oxygen Diffusion in Environmental Barrier Coating Materials

NASA Technical Reports Server (NTRS)

Good, Brian S.

2017-01-01

Ceramic Matrix Composite (CMC) materials are of interest for use in next-generation turbine engine components, offering a number of significant advantages, including reduced weight and high operating temperatures. However, in the hot environment in which such components operate, the presence of water vapor can lead to corrosion and recession, limiting the useful life of the components. Such degradation can be reduced through the use of Environmental Barrier Coatings (EBCs) that limit the amount of oxygen and water vapor reaching the component. Candidate EBC materials include Yttrium and Ytterbium silicates. In this work we present results of kinetic Monte Carlo (kMC) simulations of oxygen diffusion, via the vacancy mechanism, in Yttrium and Ytterbium disilicates, along with a brief discussion of interstitial diffusion. An EBC system typically includes a bond coat located between the EBC and the component surface. Bond coat materials are generally chosen for properties other than low oxygen diffusivity, but low oxygen diffusivity is nevertheless a desirable characteristic, as the bond coat could provide some additional component protection, particularly in the case where cracks in the coating system provide a direct path from the environment to the bond coat interface. We have therefore performed similar kMC simulations of oxygen diffusion in this material.

Self-triggering superconducting fault current limiter

DOEpatents

Yuan, Xing [Albany, NY; Tekletsadik, Kasegn [Rexford, NY

2008-10-21

A modular and scaleable Matrix Fault Current Limiter (MFCL) that functions as a "variable impedance" device in an electric power network, using components made of superconducting and non-superconducting electrically conductive materials. The matrix fault current limiter comprises a fault current limiter module that includes a superconductor which is electrically coupled in parallel with a trigger coil, wherein the trigger coil is magnetically coupled to the superconductor. The current surge doing a fault within the electrical power network will cause the superconductor to transition to its resistive state and also generate a uniform magnetic field in the trigger coil and simultaneously limit the voltage developed across the superconductor. This results in fast and uniform quenching of the superconductors, significantly reduces the burnout risk associated with non-uniformity often existing within the volume of superconductor materials. The fault current limiter modules may be electrically coupled together to form various "n" (rows).times."m" (columns) matrix configurations.

Extracellular matrix and its receptors in Drosophila neural development

PubMed Central

Broadie, Kendal; Baumgartner, Stefan; Prokop, Andreas

2011-01-01

Extracellular matrix (ECM) and matrix receptors are intimately involved in most biological processes. The ECM plays fundamental developmental and physiological roles in health and disease, including processes underlying the development, maintenance and regeneration of the nervous system. To understand the principles of ECM-mediated functions in the nervous system, genetic model organisms like Drosophila provide simple, malleable and powerful experimental platforms. This article provides an overview of ECM proteins and receptors in Drosophila. It then focuses on their roles during three progressive phases of neural development: 1) neural progenitor proliferation, 2) axonal growth and pathfinding and 3) synapse formation and function. Each section highlights known ECM and ECM-receptor components and recent studies done in mutant conditions to reveal their in vivo functions, all illustrating the enormous opportunities provided when merging work on the nervous system with systematic research into ECM-related gene functions. PMID:21688401

Fibromodulin deficiency reduces collagen structural network but not glycosaminoglycan content in a syngeneic model of colon carcinoma.

PubMed

Olsson, P Olof; Kalamajski, Sebastian; Maccarana, Marco; Oldberg, Åke; Rubin, Kristofer

2017-01-01

Tumor barrier function in carcinoma represents a major challenge to treatment and is therefore an attractive target for increasing drug delivery. Variables related to tumor barrier include aberrant blood vessels, high interstitial fluid pressure, and the composition and structure of the extracellular matrix. One of the proteins associated with dense extracellular matrices is fibromodulin, a collagen fibrillogenesis modulator expressed in tumor stroma but scarce in normal loose connective tissues. Here, we investigated the effects of fibromodulin on stroma ECM in a syngeneic murine colon carcinoma model. We show that fibromodulin deficiency decreased collagen fibril thickness but glycosaminoglycan content and composition were unchanged. Furthermore, vascular density, pericyte coverage and macrophage amount were unaffected. Fibromodulin can therefore be a unique effector of dense collagen matrix assembly in tumor stroma and, without affecting other major matrix components or the cellular composition, can function as a main agent in tumor barrier function.

PEM-PCA: a parallel expectation-maximization PCA face recognition architecture.

PubMed

Rujirakul, Kanokmon; So-In, Chakchai; Arnonkijpanich, Banchar

2014-01-01

Principal component analysis or PCA has been traditionally used as one of the feature extraction techniques in face recognition systems yielding high accuracy when requiring a small number of features. However, the covariance matrix and eigenvalue decomposition stages cause high computational complexity, especially for a large database. Thus, this research presents an alternative approach utilizing an Expectation-Maximization algorithm to reduce the determinant matrix manipulation resulting in the reduction of the stages' complexity. To improve the computational time, a novel parallel architecture was employed to utilize the benefits of parallelization of matrix computation during feature extraction and classification stages including parallel preprocessing, and their combinations, so-called a Parallel Expectation-Maximization PCA architecture. Comparing to a traditional PCA and its derivatives, the results indicate lower complexity with an insignificant difference in recognition precision leading to high speed face recognition systems, that is, the speed-up over nine and three times over PCA and Parallel PCA.

Giving structure to the biofilm matrix: an overview of individual strategies and emerging common themes.

PubMed

Hobley, Laura; Harkins, Catriona; MacPhee, Cait E; Stanley-Wall, Nicola R

2015-09-01

Biofilms are communities of microbial cells that underpin diverse processes including sewage bioremediation, plant growth promotion, chronic infections and industrial biofouling. The cells resident in the biofilm are encased within a self-produced exopolymeric matrix that commonly comprises lipids, proteins that frequently exhibit amyloid-like properties, eDNA and exopolysaccharides. This matrix fulfils a variety of functions for the community, from providing structural rigidity and protection from the external environment to controlling gene regulation and nutrient adsorption. Critical to the development of novel strategies to control biofilm infections, or the capability to capitalize on the power of biofilm formation for industrial and biotechnological uses, is an in-depth knowledge of the biofilm matrix. This is with respect to the structure of the individual components, the nature of the interactions between the molecules and the three-dimensional spatial organization. We highlight recent advances in the understanding of the structural and functional role that carbohydrates and proteins play within the biofilm matrix to provide three-dimensional architectural integrity and functionality to the biofilm community. We highlight, where relevant, experimental techniques that are allowing the boundaries of our understanding of the biofilm matrix to be extended using Escherichia coli, Staphylococcus aureus, Vibrio cholerae, and Bacillus subtilis as exemplars. © FEMS 2015.

Giving structure to the biofilm matrix: an overview of individual strategies and emerging common themes

PubMed Central

Hobley, Laura; Harkins, Catriona; MacPhee, Cait E.; Stanley-Wall, Nicola R.

2015-01-01

Biofilms are communities of microbial cells that underpin diverse processes including sewage bioremediation, plant growth promotion, chronic infections and industrial biofouling. The cells resident in the biofilm are encased within a self-produced exopolymeric matrix that commonly comprises lipids, proteins that frequently exhibit amyloid-like properties, eDNA and exopolysaccharides. This matrix fulfils a variety of functions for the community, from providing structural rigidity and protection from the external environment to controlling gene regulation and nutrient adsorption. Critical to the development of novel strategies to control biofilm infections, or the capability to capitalize on the power of biofilm formation for industrial and biotechnological uses, is an in-depth knowledge of the biofilm matrix. This is with respect to the structure of the individual components, the nature of the interactions between the molecules and the three-dimensional spatial organization. We highlight recent advances in the understanding of the structural and functional role that carbohydrates and proteins play within the biofilm matrix to provide three-dimensional architectural integrity and functionality to the biofilm community. We highlight, where relevant, experimental techniques that are allowing the boundaries of our understanding of the biofilm matrix to be extended using Escherichia coli, Staphylococcus aureus, Vibrio cholerae, and Bacillus subtilis as exemplars. PMID:25907113

Fetal brain extracellular matrix boosts neuronal network formation in 3D bioengineered model of cortical brain tissue.

PubMed

Sood, Disha; Chwalek, Karolina; Stuntz, Emily; Pouli, Dimitra; Du, Chuang; Tang-Schomer, Min; Georgakoudi, Irene; Black, Lauren D; Kaplan, David L

2016-01-01

The extracellular matrix (ECM) constituting up to 20% of the organ volume is a significant component of the brain due to its instructive role in the compartmentalization of functional microdomains in every brain structure. The composition, quantity and structure of ECM changes dramatically during the development of an organism greatly contributing to the remarkably sophisticated architecture and function of the brain. Since fetal brain is highly plastic, we hypothesize that the fetal brain ECM may contain cues promoting neural growth and differentiation, highly desired in regenerative medicine. Thus, we studied the effect of brain-derived fetal and adult ECM complemented with matricellular proteins on cortical neurons using in vitro 3D bioengineered model of cortical brain tissue. The tested parameters included neuronal network density, cell viability, calcium signaling and electrophysiology. Both, adult and fetal brain ECM as well as matricellular proteins significantly improved neural network formation as compared to single component, collagen I matrix. Additionally, the brain ECM improved cell viability and lowered glutamate release. The fetal brain ECM induced superior neural network formation, calcium signaling and spontaneous spiking activity over adult brain ECM. This study highlights the difference in the neuroinductive properties of fetal and adult brain ECM and suggests that delineating the basis for this divergence may have implications for regenerative medicine.

METCAN-PC - METAL MATRIX COMPOSITE ANALYZER

NASA Technical Reports Server (NTRS)

Murthy, P. L.

1994-01-01

High temperature metal matrix composites offer great potential for use in advanced aerospace structural applications. The realization of this potential however, requires concurrent developments in (1) a technology base for fabricating high temperature metal matrix composite structural components, (2) experimental techniques for measuring their thermal and mechanical characteristics, and (3) computational methods to predict their behavior. METCAN (METal matrix Composite ANalyzer) is a computer program developed to predict this behavior. METCAN can be used to computationally simulate the non-linear behavior of high temperature metal matrix composites (HT-MMC), thus allowing the potential payoff for the specific application to be assessed. It provides a comprehensive analysis of composite thermal and mechanical performance. METCAN treats material nonlinearity at the constituent (fiber, matrix, and interphase) level, where the behavior of each constituent is modeled accounting for time-temperature-stress dependence. The composite properties are synthesized from the constituent instantaneous properties by making use of composite micromechanics and macromechanics. Factors which affect the behavior of the composite properties include the fabrication process variables, the fiber and matrix properties, the bonding between the fiber and matrix and/or the properties of the interphase between the fiber and matrix. The METCAN simulation is performed as point-wise analysis and produces composite properties which are readily incorporated into a finite element code to perform a global structural analysis. After the global structural analysis is performed, METCAN decomposes the composite properties back into the localized response at the various levels of the simulation. At this point the constituent properties are updated and the next iteration in the analysis is initiated. This cyclic procedure is referred to as the integrated approach to metal matrix composite analysis. METCAN-PC is written in FORTRAN 77 for IBM PC series and compatible computers running MS-DOS. An 80286 machine with an 80287 math co-processor is required for execution. The executable requires at least 640K of RAM and DOS 3.1 or higher. The package includes sample executables which were compiled under Microsoft FORTRAN v. 5.1. The standard distribution medium for this program is one 5.25 inch 360K MS-DOS format diskette. The contents of the diskette are compressed using the PKWARE archiving tools. The utility to unarchive the files, PKUNZIP.EXE, is included. METCAN-PC was developed in 1992.

Large Covariance Estimation by Thresholding Principal Orthogonal Complements

PubMed Central

Fan, Jianqing; Liao, Yuan; Mincheva, Martina

2012-01-01

This paper deals with the estimation of a high-dimensional covariance with a conditional sparsity structure and fast-diverging eigenvalues. By assuming sparse error covariance matrix in an approximate factor model, we allow for the presence of some cross-sectional correlation even after taking out common but unobservable factors. We introduce the Principal Orthogonal complEment Thresholding (POET) method to explore such an approximate factor structure with sparsity. The POET estimator includes the sample covariance matrix, the factor-based covariance matrix (Fan, Fan, and Lv, 2008), the thresholding estimator (Bickel and Levina, 2008) and the adaptive thresholding estimator (Cai and Liu, 2011) as specific examples. We provide mathematical insights when the factor analysis is approximately the same as the principal component analysis for high-dimensional data. The rates of convergence of the sparse residual covariance matrix and the conditional sparse covariance matrix are studied under various norms. It is shown that the impact of estimating the unknown factors vanishes as the dimensionality increases. The uniform rates of convergence for the unobserved factors and their factor loadings are derived. The asymptotic results are also verified by extensive simulation studies. Finally, a real data application on portfolio allocation is presented. PMID:24348088

Large Covariance Estimation by Thresholding Principal Orthogonal Complements.

PubMed

Fan, Jianqing; Liao, Yuan; Mincheva, Martina

2013-09-01

This paper deals with the estimation of a high-dimensional covariance with a conditional sparsity structure and fast-diverging eigenvalues. By assuming sparse error covariance matrix in an approximate factor model, we allow for the presence of some cross-sectional correlation even after taking out common but unobservable factors. We introduce the Principal Orthogonal complEment Thresholding (POET) method to explore such an approximate factor structure with sparsity. The POET estimator includes the sample covariance matrix, the factor-based covariance matrix (Fan, Fan, and Lv, 2008), the thresholding estimator (Bickel and Levina, 2008) and the adaptive thresholding estimator (Cai and Liu, 2011) as specific examples. We provide mathematical insights when the factor analysis is approximately the same as the principal component analysis for high-dimensional data. The rates of convergence of the sparse residual covariance matrix and the conditional sparse covariance matrix are studied under various norms. It is shown that the impact of estimating the unknown factors vanishes as the dimensionality increases. The uniform rates of convergence for the unobserved factors and their factor loadings are derived. The asymptotic results are also verified by extensive simulation studies. Finally, a real data application on portfolio allocation is presented.

Efficient l1 -norm-based low-rank matrix approximations for large-scale problems using alternating rectified gradient method.

PubMed

Kim, Eunwoo; Lee, Minsik; Choi, Chong-Ho; Kwak, Nojun; Oh, Songhwai

2015-02-01

Low-rank matrix approximation plays an important role in the area of computer vision and image processing. Most of the conventional low-rank matrix approximation methods are based on the l2 -norm (Frobenius norm) with principal component analysis (PCA) being the most popular among them. However, this can give a poor approximation for data contaminated by outliers (including missing data), because the l2 -norm exaggerates the negative effect of outliers. Recently, to overcome this problem, various methods based on the l1 -norm, such as robust PCA methods, have been proposed for low-rank matrix approximation. Despite the robustness of the methods, they require heavy computational effort and substantial memory for high-dimensional data, which is impractical for real-world problems. In this paper, we propose two efficient low-rank factorization methods based on the l1 -norm that find proper projection and coefficient matrices using the alternating rectified gradient method. The proposed methods are applied to a number of low-rank matrix approximation problems to demonstrate their efficiency and robustness. The experimental results show that our proposals are efficient in both execution time and reconstruction performance unlike other state-of-the-art methods.

Disentangling giant component and finite cluster contributions in sparse random matrix spectra.

PubMed

Kühn, Reimer

2016-04-01

We describe a method for disentangling giant component and finite cluster contributions to sparse random matrix spectra, using sparse symmetric random matrices defined on Erdős-Rényi graphs as an example and test bed. Our methods apply to sparse matrices defined in terms of arbitrary graphs in the configuration model class, as long as they have finite mean degree.

The mesangial matrix in the normal and sclerotic glomerulus.

PubMed

Rosenblum, N D

1994-02-01

Mesangial sclerosis is a final common pathway to glomerular destruction in a variety of glomerular diseases. The expression of several classes of extracellular matrix (ECM) molecules has been defined in the normal and diseased mesangial matrix (MM). However, the manner in which these ECM components determine the three dimensional structure and function of the MM remains to be defined. Structural studies of the MM suggest that its constituent molecules are regionally organized into subcompartments with different three dimensional structures. The diversity of matrix molecules expressed within the MM as well as the organization of these components in nonrenal ECM's, such as the cornea, provides further support for this organizational model. The study of the cornea has also revealed that novel short chain collagenous proteins partially determine the three dimensional structure of the matrix. Recently, a novel collagen, type VIII collagen, has been described in mesangial cells and in the intact glomerulus. It is hypothesized that type VIII collagen is expressed both as a polymer and as a monomer within the glomerulus, and depending on its conformation, may serve unique functions. In the chronically diseased MM, normal MM components are overexpressed and fibrillar collagens are expressed de novo in a delayed fashion. Enhanced proteoglycan expression, observed early in disease, may determine increased volume of the mesangium. This, in turn, may stimulate the production of fibrillar collagens by mesangial cells resulting in a fibrillar noncompliant mesangial matrix.

Degradation of extracellular matrix by mouse trophoblast outgrowths: a model for implantation

PubMed Central

Glass, RH; Aggeler, J; Spindle, A; Pederson, RA; Werb, Z

1983-01-01

During implantation the embryo attaches to the endometrial surface and trophoblast traverses the uterine epithelium, anchoring in the uterine connective tissue. To determine whether trophoblast can facilitate invasion of the uterus by degrading components of normal uterine extracellular matrix, mouse blastocysts were cultured on a radio-labeled extracellular matrix that contained glycoproteins, elastin, and collagen. The embryos attached to the matrix, and trophoblast spread over the surface. Starting on day 5 of culture there was a release of labeled peptides into the medium. The radioactive peptides released from the matrix by the embryos had molecular weights ranging from more than 25,000 to more than 200. By day 7 there were areas where individual trophoblast cells had separated from one another, revealing the underlying substratum that was cleared of matrix. When trophoblast cells were lysed with NH(4)OH on day 8, it was apparent that the area underneath the trophoblast outgrowth had been cleared of matrix. Scanning electron microscopy and time-lapse cinemicrography confirmed that the digestion of matrix was highly localized, taking place only underneath the trophoblast, with no evidence of digestion of the matrix beyond the periphery of the trophoblast outgrowth. The sharp boundaries of degredation observed may be due to localized proteinase secretion by trophoblast, to membrane proteinases on the surface of trophoblast, or to endocytosis. Digestion of the matrix was not dependent on plasminogen, thus ruling out a role for plasminogen activator. Digestion was not inhibited by a variety of hormones and inhibitors, including progesterone, 17β-estradiol, leupeptin, EDTA, colchicine, NH(4)Cl, or ε-aminocaproic acid. This system of culturing embryos on extracellular matrix may be useful in determining the processes that regulate trophoblast migration and invasion into the maternal tissues during implantation.0 PMID:6339525

Proposed framework for thermomechanical life modeling of metal matrix composites

NASA Technical Reports Server (NTRS)

Halford, Gary R.; Lerch, Bradley A.; Saltsman, James F.

1993-01-01

The framework of a mechanics of materials model is proposed for thermomechanical fatigue (TMF) life prediction of unidirectional, continuous-fiber metal matrix composites (MMC's). Axially loaded MMC test samples are analyzed as structural components whose fatigue lives are governed by local stress-strain conditions resulting from combined interactions of the matrix, interfacial layer, and fiber constituents. The metallic matrix is identified as the vehicle for tracking fatigue crack initiation and propagation. The proposed framework has three major elements. First, TMF flow and failure characteristics of in situ matrix material are approximated from tests of unreinforced matrix material, and matrix TMF life prediction equations are numerically calibrated. The macrocrack initiation fatigue life of the matrix material is divided into microcrack initiation and microcrack propagation phases. Second, the influencing factors created by the presence of fibers and interfaces are analyzed, characterized, and documented in equation form. Some of the influences act on the microcrack initiation portion of the matrix fatigue life, others on the microcrack propagation life, while some affect both. Influencing factors include coefficient of thermal expansion mismatch strains, residual (mean) stresses, multiaxial stress states, off-axis fibers, internal stress concentrations, multiple initiation sites, nonuniform fiber spacing, fiber debonding, interfacial layers and cracking, fractured fibers, fiber deflections of crack fronts, fiber bridging of matrix cracks, and internal oxidation along internal interfaces. Equations exist for some, but not all, of the currently identified influencing factors. The third element is the inclusion of overriding influences such as maximum tensile strain limits of brittle fibers that could cause local fractures and ensuing catastrophic failure of surrounding matrix material. Some experimental data exist for assessing the plausibility of the proposed framework.

Stress as an order parameter for the glass transition

NASA Astrophysics Data System (ADS)

Visscher, P. B.; Logan, W. T.

1990-09-01

The stress tensor has been considered as a possible order parameter for the liquid-glass transition, and its autocorrelation matrix (elements of which are the integrands in the Green-Kubo formulas for bulk and shear viscosity) have been measured in simulations. However, only the k=0 spatial Fourier component has apparently been previously measured. We have measured four Fourier components of all matrix elements of the stress-stress correlation function, and we find that some of those with nonzero wave vector are significantly more persistent (slower decaying) than the k=0 component.

An Electrostatic Net Model for the Role of Extracellular DNA in Biofilm Formation by Staphylococcus aureus.

PubMed

Dengler, Vanina; Foulston, Lucy; DeFrancesco, Alicia S; Losick, Richard

2015-12-01

Staphylococcus aureus is an important human pathogen that can form biofilms on various surfaces. These cell communities are protected from the environment by a self-produced extracellular matrix composed of proteins, DNA, and polysaccharide. The exact compositions and roles of the different components are not fully understood. In this study, we investigated the role of extracellular DNA (eDNA) and its interaction with the recently identified cytoplasmic proteins that have a moonlighting role in the biofilm matrix. These matrix proteins associate with the cell surface upon the drop in pH that naturally occurs during biofilm formation, and we found here that this association is independent of eDNA. Conversely, the association of eDNA with the matrix was dependent on matrix proteins. Both proteinase and DNase treatments severely reduced clumping of resuspended biofilms; highlighting the importance of both proteins and eDNA in connecting cells together. By adding an excess of exogenous DNA to DNase-treated biofilm, clumping was partially restored, confirming the crucial role of eDNA in the interconnection of cells. On the basis of our results, we propose that eDNA acts as an electrostatic net, interconnecting cells surrounded by positively charged matrix proteins at a low pH. Extracellular DNA (eDNA) is an important component of the biofilm matrix of diverse bacteria, but its role in biofilm formation is not well understood. Here we report that in Staphylococcus aureus, eDNA associates with cells in a manner that depends on matrix proteins and that eDNA is required to link cells together in the biofilm. These results confirm previous studies that showed that eDNA is an important component of the S. aureus biofilm matrix and also suggest that eDNA acts as an electrostatic net that tethers cells together via the proteinaceous layer of the biofilm matrix. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Influence of different metal ions on the ultrastructure, biochemical properties, and protein localization of the K562 cell nuclear matrix.

PubMed

Neri, L M; Bortul, R; Zweyer, M; Tabellini, G; Borgatti, P; Marchisio, M; Bareggi, R; Capitani, S; Martelli, A M

1999-06-01

The higher order of chromatin organization is thought to be determined by the nuclear matrix, a mainly proteinaceous structure that would act as a nucleoskeleton. The matrix is obtained from isolated nuclei by a series of extraction steps involving the use of high salt and nonspecific nucleases, which remove chromatin and other loosely bound components. It is currently under debate whether these structures, isolated in vitro by unphysiological extraction buffers, correspond to a nucleoskeleton existing in vivo. In most cell types investigated, the nuclear matrix does not spontaneously resist these extractions steps; rather, it must be stabilized before the application of extracting agents. In this study nuclei, isolated from K562 human erythroleukemia cells, were stabilized by incubation with different metal ions (Ca2+, Cu2+, Zn2+, Cd2+), and the matrix was obtained by extraction with 2 M NaCl. By means of ultrastructural analysis of the resulting structures, we determined that, except for Ca2+, all the other metals induced a stabilization of the matrix, which retained the inner fibrogranular network and residual nucleoli. The biochemical composition, analyzed by two-dimensional gel electrophoresis separation, exhibited a distinct matrix polypeptide pattern, characteristic of each type of stabilizing ion employed. We also investigated to what extent metal ions could maintain in the final structures the original distribution of three inner matrix components, i.e. NuMA, topoisomerase IIalpha, and RNP. Confocal microscopy analysis showed that only NuMa, and, to a lesser extent, topoisomerase IIalpha, were unaffected by stabilization with divalent ions. On the contrary, the fluorescent RNP patterns detected in the resulting matrices were always disarranged, irrespective of the stabilization procedure. These results indicate that several metal ions are powerful stabilizing agents of the nuclear matrix prepared from K562 erythroleukemia cells and also strengthen the concept that NuMA and topoisomerase IIalpha may act as structural components of the nuclear matrix.

Repeated decompositions reveal the stability of infomax decomposition of fMRI data

PubMed Central

Duann, Jeng-Ren; Jung, Tzyy-Ping; Sejnowski, Terrence J.; Makeig, Scott

2010-01-01

In this study, we decomposed 12 fMRI data sets from six subjects each 101 times using the infomax algorithm. The first decomposition was taken as a reference decomposition; the others were used to form a component matrix of 100 by 100 components. Equivalence relations between components in this matrix, defined as maximum spatial correlations to the components of the reference decomposition, were found by the Hungarian sorting method and used to form 100 equivalence classes for each data set. We then tested the reproducibility of the matched components in the equivalence classes using uncertainty measures based on component distributions, time courses, and ROC curves. Infomax ICA rarely failed to derive nearly the same components in different decompositions. Very few components per data set were poorly reproduced, even using vector angle uncertainty measures stricter than correlation and detection theory measures. PMID:17281453

Advanced composite materials for optomechanical systems

NASA Astrophysics Data System (ADS)

Zweben, Carl

2013-09-01

Polymer matrix composites (PMCs) have been well established in optomechanical systems for several decades. The other three classes of composites; metal matrix composites (MMCs), ceramic matrix composites (CMCs), and carbon matrix composites (CAMCs) are making significant inroads. The latter include carbon/carbon (C/C) composites (CCCs). The success of composites has resulted in increasing use in consumer, industrial, scientific, and aerospace/defense optomechanical applications. Composites offer significant advantages over traditional materials, including high stiffnesses and strengths, near-zero and tailorable coefficients of thermal expansion (CTEs), tailorable thermal conductivities (from very low to over twice that of copper), and low densities. In addition, they lack beryllium's toxicity problems. Some manufacturing processes allow parts consolidation, reducing machining and joining operations. At present, PMCs are the most widely used composites. Optomechanical applications date from the 1970s. The second High Energy Astrophysical Observatory spacecraft, placed in orbit in 1978, had an ultrahigh-modulus carbon fiber-reinforced epoxy (carbon/epoxy) optical bench metering structure. Since then, fibers and matrix materials have advanced significantly, and use of carbon fiber-reinforced polymers (CFRPs) has increased steadily. Space system examples include the Hubble Space Telescope metering truss and instrument benches, Upper Atmosphere Research Satellite (UARS), James Webb Space Telescope and many others. Use has spread to airborne applications, such as SOFIA. Perhaps the most impressive CFRP applications are the fifty-four 12m and twelve 7m moveable ground-based ALMA antennas. The other three classes of composites have a number of significant advantages over PMCs, including no moisture absorption or outgassing of organic compounds. CCC and CMC components have flown on a variety of spacecraft. MMCs have been used in space, aircraft, military and industrial applications. In this paper, we review key PMC, MMC, CCC, and CMC optomechanical system materials, including properties, advantages, disadvantages, applications and future developments. These topics are covered in more detail in SPIE short courses SC218 and SC1078.

Three-dimensional biocompatible matrix for reconstructive surgery

NASA Astrophysics Data System (ADS)

Reshetov, I. V.; Starceva, O. I.; Istranov, A. L.; Vorona, B. N.; Lyundup, A. V.; Gulyaev, I. V.; Melnikov, D. V.; Shtansky, D. V.; Sheveyko, A. N.; Andreev, V. A.

2016-08-01

A study into the development of an original bioengineered structure for reconstruction of hollow organs is presented. The basis for the structure was the creation of a mesh matrix made from titanium nickelide (NiTi), which has sufficient elasticity and shape memory for the reconstruction of hollow tubular orgrans. In order to increase the cell adhesion on the surface of the matrix, the grid needed to be cleaned of impurities, for which we used an ionic cleaning method. Additional advantages also may enable the application of the bioactive component to grid surface. These features of the matrix may improve the biocompatibility properties of the composite material. In the first stage, a mesh structure was made from NiTi fibers. The properties of the resulting mesh matrix were studied. In the second stage, the degrees of adhesion and cell growth rates in the untreated matrix, the matrix after ionic cleaning and the matrix after ionic cleaning and the application of the bioactive component were compared. The results showed more significant biocompatibility of the titanium nickelide matrix after its ionic cleaning. The ionic cleaning ensures the removal of toxic contaminants, which are a consequence of the technological production process of the material and provide optimal adhesion properties for the fiber surface. The NiTi net matrix with TiCaPCON coating may be the optimal basis for making the hollow elastic organs.

Large-scale production and isolation of Candida biofilm extracellular matrix.

PubMed

Zarnowski, Robert; Sanchez, Hiram; Andes, David R

2016-12-01

The extracellular matrix of biofilm is unique to the biofilm lifestyle, and it has key roles in community survival. A complete understanding of the biochemical nature of the matrix is integral to the understanding of the roles of matrix components. This knowledge is a first step toward the development of novel therapeutics and diagnostics to address persistent biofilm infections. Many of the assay methods needed for refined matrix composition analysis require milligram amounts of material that is separated from the cellular components of these complex communities. The protocol described here explains the large-scale production and isolation of the Candida biofilm extracellular matrix. To our knowledge, the proposed procedure is the only currently available approach in the field that yields milligram amounts of biofilm matrix. This procedure first requires biofilms to be seeded in large-surface-area roller bottles, followed by cell adhesion and biofilm maturation during continuous movement of the medium across the surface of the rotating bottle. The formed matrix is then separated from the entire biomass using sonication, which efficiently removes the matrix without perturbing the fungal cell wall. Subsequent filtration, dialysis and lyophilization steps result in a purified matrix product sufficient for biochemical, structural and functional assays. The overall protocol takes ∼11 d to complete. This protocol has been used for Candida species, but, using the troubleshooting guide provided, it could be adapted for other fungi or bacteria.

Controlling Microbial Safety Challenges of Meat Using High Voltage Atmospheric Cold Plasma

PubMed Central

Han, Lu; Ziuzina, Dana; Heslin, Caitlin; Boehm, Daniela; Patange, Apurva; Sango, David M.; Valdramidis, Vasilis P.; Cullen, Patrick J.; Bourke, Paula

2016-01-01

Atmospheric cold plasma (ACP) is a non-thermal technology, effective against a wide range of pathogenic microorganisms. Inactivation efficacy results from plasma generated reactive species. These may interact with any organic components in a test matrix including the target microorganism, thus food components may exert a protective effect against the antimicrobial mode of action. The effect of an in-package high voltage ACP process applied in conjunction with common meat processing MAP gas compositions as well as bacteria type and meat model media composition have been investigated to determine the applicability of this technology for decontamination of safety challenges associated with meat products. E. coli, L. monocytogenes, and S. aureus in PBS were undetectable after 60 s of treatment at 80 kVRMS in air, while ACP treatment of the contaminated meat model required post-treatment refrigeration to retain antimicrobial effect. The nutritive components in the meat model exerted a protective effect during treatment, where 300 s ACP exposure yielded a maximum reduction of 1.5 log using a high oxygen atmosphere, whilst using air and high nitrogen atmospheres yielded lower antimicrobial efficacy. Furthermore, an ROS assay was performed to understand the protective effects observed using the meat model. This revealed that nutritive components inhibited penetration of ROS into bacterial cells. This knowledge can assist the optimization of meat decontamination using ACP technology where interactions with all components of the food matrix require evaluation. PMID:27446018

Extracellular Matrix Remodeling: The Common Denominator in Connective Tissue DiseasesPossibilities for Evaluation and Current Understanding of the Matrix as More Than a Passive Architecture, but a Key Player in Tissue Failure

PubMed Central

Nielsen, Mette J.; Sand, Jannie M.; Henriksen, Kim; Genovese, Federica; Bay-Jensen, Anne-Christine; Smith, Victoria; Adamkewicz, Joanne I.; Christiansen, Claus; Leeming, Diana J.

2013-01-01

Abstract Increased attention is paid to the structural components of tissues. These components are mostly collagens and various proteoglycans. Emerging evidence suggests that altered components and noncoded modifications of the matrix may be both initiators and drivers of disease, exemplified by excessive tissue remodeling leading to tissue stiffness, as well as by changes in the signaling potential of both intact matrix and fragments thereof. Although tissue structure until recently was viewed as a simple architecture anchoring cells and proteins, this complex grid may contain essential information enabling the maintenance of the structure and normal functioning of tissue. The aims of this review are to (1) discuss the structural components of the matrix and the relevance of their mutations to the pathology of diseases such as fibrosis and cancer, (2) introduce the possibility that post-translational modifications (PTMs), such as protease cleavage, citrullination, cross-linking, nitrosylation, glycosylation, and isomerization, generated during pathology, may be unique, disease-specific biochemical markers, (3) list and review the range of simple enzyme-linked immunosorbent assays (ELISAs) that have been developed for assessing the extracellular matrix (ECM) and detecting abnormal ECM remodeling, and (4) discuss whether some PTMs are the cause or consequence of disease. New evidence clearly suggests that the ECM at some point in the pathogenesis becomes a driver of disease. These pathological modified ECM proteins may allow insights into complicated pathologies in which the end stage is excessive tissue remodeling, and provide unique and more pathology-specific biochemical markers. PMID:23046407

Synthesis and Characterisation of ETS-10/Acetate-based Ionic Liquid/Chitosan Mixed Matrix Membranes for CO2/N2 Permeation.

PubMed

Casado-Coterillo, Clara; Del Mar López-Guerrero, María; Irabien, Angel

2014-06-19

Mixed matrix membranes (MMMs) were prepared by incorporating organic surfactant-free hydrothermally synthesised ETS-10 and 1-ethyl-3-methylimidazolium acetate ionic liquid (IL) to chitosan (CS) polymer matrix. The membrane material characteristics and permselectivity performance of the two-component membranes were compared with the three-component membrane and the pure CS membrane. The addition of IL increased CO2 solubility of the polymer, and, thus, the CO2 affinity was maintained for the MMMs, which can be correlated with the crystallinity, measured by FT-IR, and void fraction calculations from differences between theoretical and experimental densities. The mechanical resistance was enhanced by the ETS-10 nanoparticles, and flexibility decreased in the two-component ETS-10/CS MMMs, but the flexibility imparted by the IL remained in three-component ETS-10/IL/CS MMMs. The results of this work provide insight into another way of facing the adhesion challenge in MMMs and obtain CO2 selective MMMs from renewable or green chemistry materials.

Effective thermoelastic properties of discrete-fiber reinforced materials with transversally-isotropic components

NASA Astrophysics Data System (ADS)

Nazarenko, Lidiya; Khoroshun, Leonid; Müller, Wolfgang H.; Wille, Ralf

2009-02-01

In the present paper, we will illustrate the application of the method of conditional moments by constructing the algorithm for determination of the effective elastic properties of composites from the given elastic constants of the components and geometrical parameters of inclusions. A special case of two-component matrix composite with randomly distributed unidirectional spheroidal inclusions is considered. To this end it is assumed that the components of the composite show transversally isotropic symmetry of thermoelastic properties and that the axes of symmetry of the thermoelastic properties of the matrix and inclusions coincide with the coordinate axis x 3. As a numerical example a composite based on carbon inclusions and epoxide matrix is investigated. The dependencies of Young’s moduli, Poisson’s ratios and shear modulus from the concentration of inclusions and for certain values which characterize the shape of inclusions are analyzed. The results are compared and discussed in context with other theoretical predictions and experimental data.

Comparative Study of Biological Activities of Venom from Colubrid Snakes Rhabdophis tigrinus (Yamakagashi) and Rhabdophis lateralis

PubMed Central

Komori, Yumiko; Hifumi, Toru; Yamamoto, Akihiko; Sakai, Atsushi; Sawabe, Kyoko; Nikai, Toshiaki

2017-01-01

Rhabdophis lateralis, a colubrid snake distributed throughout the continent of Asia, has recently undergone taxonomic revisions. Previously, Rhabdophis lateralis was classified as a subspecies of R. tigrinus (Yamakagashi) until 2012, when several genetic differences were discovered which classified this snake as its own species. To elucidate the toxicity of venom from this poorly studied colubrid, various biological activities were compared between the venom from the two snake species. The components of their venom were compared by the elution profiles of reversed-phase HPLC and SDS-PAGE, and gel filtrated fractions were tested for effects on blood coagulation. Proteolytic activities of these fractions were also assayed by using synthetic substrates, fibrinogen, and matrix proteins. Similar to the R. tigrinus venom, the higher molecular weight fraction of R. lateralis venom contained a prothrombin activator. Both prothrombin time (PT) and activated partial thromboplastin time (APTT) of human plasma were shortened by the addition of R. lateralis and R. tigrinus venom. The thrombin formation was estimated by the uses of SDS-PAGE and chromogenic substrates. These venom fractions also possessed very specific proteinase activity on human fibrinogen, but the substrates for matrix metalloproteinase, such as collagen and laminin, were not hydrolyzed. However, there were some notable differences in reactivity to synthetic substrates for matrix metalloproteinase, and R. tigrinus venom possessed relatively higher activity. Our chemical investigation indicates that the components included in both venoms resemble each other closely. However, the ratio of components and proteolytic activity of some ingredients are slightly different, indicating differences between two closely-related snakes. PMID:29149042

The involvement of heparan sulfate proteoglycans in stem cell differentiation and in malignant glioma

NASA Astrophysics Data System (ADS)

Kundu, Soumi; Xiong, Anqi; Forsberg-Nilsson, Karin

2016-04-01

Heparan sulfate (HS) proteoglycans (HSPG) are major components of the extracellular matrix. They interact with a plethora of macromolecules that are of physiological importance. The pattern of sulfation of the HS chain determines the specificity of these interactions. The enzymes that synthesize and degrade HS are thus key regulators of processes ranging from embryonic development to tissue homeostasis and tumor development. Formation of the nervous system is also critically dependent on appropriate HSPGs as shown by several studies on the role of HS in neural induction from embryonic stem cells. High-grade glioma is the most common primary malignant brain tumor among adults, and the prognosis is poor. Neural and glioma stem cells share several traits, including sustained proliferation and highly efficient migration in the brain. There are also similarities between the neurogenic niche where adult neural stem cells reside and the tumorigenic niche, including their interactions with components of the extracellular matrix (ECM). The levels of many of these components, for example HSPGs and enzymes involved in the biosynthesis and modification of HS are attenuated in gliomas. In this paper, HS regulation of pathways involved in neural differentiation and how these may be of importance for brain development are discussed. The literature suggesting that modifications of HS could regulate glioma growth and invasion is reviewed. Targeting the invasiveness of glioma cells by modulating HS may improve upon present therapeutic options, which only marginally enhance the survival of glioma patients.

Monitoring Damage Accumulation in Ceramic Matrix Composites Using Electrical Resistivity

NASA Technical Reports Server (NTRS)

Smith, Craig E.; Morscher, Gregory N.; Xia, Zhenhai H.

2008-01-01

The electric resistance of woven SiC fiber reinforced SiC matrix composites were measured under tensile loading conditions. The results show that the electrical resistance is closely related to damage and that real-time information about the damage state can be obtained through monitoring of the resistance. Such self-sensing capability provides the possibility of on-board/in-situ damage detection and accurate life prediction for high-temperature ceramic matrix composites. Woven silicon carbide fiber-reinforced silicon carbide (SiC/SiC) ceramic matrix composites (CMC) possess unique properties such as high thermal conductivity, excellent creep resistance, improved toughness, and good environmental stability (oxidation resistance), making them particularly suitable for hot structure applications. In specific, CMCs could be applied to hot section components of gas turbines [1], aerojet engines [2], thermal protection systems [3], and hot control surfaces [4]. The benefits of implementing these materials include reduced cooling air requirements, lower weight, simpler component design, longer service life, and higher thrust [5]. It has been identified in NASA High Speed Research (HSR) program that the SiC/SiC CMC has the most promise for high temperature, high oxidation applications [6]. One of the critical issues in the successful application of CMCs is on-board or insitu assessment of the damage state and an accurate prediction of the remaining service life of a particular component. This is of great concern, since most CMC components envisioned for aerospace applications will be exposed to harsh environments and play a key role in the vehicle s safety. On-line health monitoring can enable prediction of remaining life; thus resulting in improved safety and reliability of structural components. Monitoring can also allow for appropriate corrections to be made in real time, therefore leading to the prevention of catastrophic failures. Most conventional nondestructive evaluation (NDE) techniques such as ultrasonic C-scan, x-ray, thermography, and eddy current are limited since they require structural components of complex geometry to be taken out of service for a substantial length of time for post-damage inspection and assessment. Furthermore, the typical NDE techniques are useful for identifying large interlaminar flaws, but insensitive to CMC materials flaws developed perpendicular to the surface under tensile creep conditions. There are techniques such as piezoelectric sensor [7,8], and optical fiber [9,10] that could be used for on-line health monitoring of CMC structures. However, these systems involve attaching an external sensor or putting special fibers in CMC composites, which would be problematic at high temperature applications.

Skeletal biology: Where matrix meets mineral

PubMed Central

Young, Marian F.

2017-01-01

The skeleton is unique from all other tissues in the body because of its ability to mineralize. The incorporation of mineral into bones and teeth is essential to give them strength and structure for body support and function. For years, researchers have wondered how mineralized tissues form and repair. A major focus in this context has been on the role of the extracellular matrix, which harbors key regulators of the mineralization process. In this introductory minireview, we will review some key concepts of matrix biology as it related to mineralized tissues. Concurrently, we will highlight the subject of this special issue covering many aspects of mineralized tissues, including bones and teeth and their associated structures cartilage and tendon. Areas of emphasis are on the generation and analysis of new animal models with permutations of matrix components as well as the development of new approaches for tissue engineering for repair of damaged hard tissue. In assembling key topics on mineralized tissues written by leaders in our field, we hope the reader will get a broad view of the topic and all of its fascinating complexities. PMID:27131884

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

PubMed

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

2016-04-01

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

A Glimpse of Matrix Metalloproteinases in Diabetic Nephropathy

PubMed Central

Xu, X.; Xiao, L.; Xiao, P.; Yang, S.; Chen, G.; Liu, F.; Kanwar, Y.Y.; Sun, L.

2014-01-01

Matrix metalloproteinases (MMPs) are proteolytic enzymes belonging to the family of zinc-dependent endopeptidases that are capable of degrading almost all the proteinaceous components of the extracellular matrix (ECM). It is known that MMPs play a role in a number of renal diseases, such as, various forms of glomerulonephritis and tubular diseases, including some of the inherited kidney diseases. In this regard, ECM accumulation is considered to be a hallmark morphologic finding of diabetic nephropathy, which not only is related to the excessive synthesis of matrix proteins, but also to their decreased degradation by the MMPs. In recent years, increasing evidence suggest that there is a good correlation between the activity or expression of MMPs and progression of renal disease in patients with diabetic nephropathy in humans and in various experimental animal models. In such a diabetic milieu, the expression of MMPs is modulated by high glucose, advanced glycation end products (AGEs), TGF-β, reactive oxygen species (ROS), transcription factors and some of the microRNAs. In this review, we focused on the structure and functions of MMPs, and their role in the pathogenesis of diabetic nephropathy. PMID:25039784

BIREFRINGENT FILTER MODEL

NASA Technical Reports Server (NTRS)

Cross, P. L.

1994-01-01

Birefringent filters are often used as line-narrowing components in solid state lasers. The Birefringent Filter Model program generates a stand-alone model of a birefringent filter for use in designing and analyzing a birefringent filter. It was originally developed to aid in the design of solid state lasers to be used on aircraft or spacecraft to perform remote sensing of the atmosphere. The model is general enough to allow the user to address problems such as temperature stability requirements, manufacturing tolerances, and alignment tolerances. The input parameters for the program are divided into 7 groups: 1) general parameters which refer to all elements of the filter; 2) wavelength related parameters; 3) filter, coating and orientation parameters; 4) input ray parameters; 5) output device specifications; 6) component related parameters; and 7) transmission profile parameters. The program can analyze a birefringent filter with up to 12 different components, and can calculate the transmission and summary parameters for multiple passes as well as a single pass through the filter. The Jones matrix, which is calculated from the input parameters of Groups 1 through 4, is used to calculate the transmission. Output files containing the calculated transmission or the calculated Jones' matrix as a function of wavelength can be created. These output files can then be used as inputs for user written programs. For example, to plot the transmission or to calculate the eigen-transmittances and the corresponding eigen-polarizations for the Jones' matrix, write the appropriate data to a file. The Birefringent Filter Model is written in Microsoft FORTRAN 2.0. The program format is interactive. It was developed on an IBM PC XT equipped with an 8087 math coprocessor, and has a central memory requirement of approximately 154K. Since Microsoft FORTRAN 2.0 does not support complex arithmetic, matrix routines for addition, subtraction, and multiplication of complex, double precision variables are included. The Birefringent Filter Model was written in 1987.

WALLY 1 ...A large, principal components regression program with varimax rotation of the factor weight matrix

Treesearch

James R. Wallis

1965-01-01

Written in Fortran IV and MAP, this computer program can handle up to 120 variables, and retain 40 principal components. It can perform simultaneous regression of up to 40 criterion variables upon the varimax rotated factor weight matrix. The columns and rows of all output matrices are labeled by six-character alphanumeric names. Data input can be from punch cards or...

Effects of Ethanol on Brain Extracellular Matrix: Implications for Alcohol Use Disorder.

PubMed

Lasek, Amy W

2016-10-01

The brain extracellular matrix (ECM) occupies the space between cells and is involved in cell-matrix and cell-cell adhesion. However, in addition to providing structural support to brain tissue, the ECM activates cell signaling and controls synaptic transmission. The expression and activity of brain ECM components are regulated by alcohol exposure. This review will discuss what is currently known about the effects of alcohol on the activity and expression of brain ECM components. An interpretation of how these changes might promote alcohol use disorder (AUD) will be also provided. Ethanol (EtOH) exposure decreases levels of structural proteins involved in the interstitial matrix and basement membrane, with a concomitant increase in proteolytic enzymes that degrade these components. In contrast, EtOH exposure generally increases perineuronal net components. Because the ECM has been shown to regulate both synaptic plasticity and behavioral responses to drugs of abuse, regulation of the brain ECM by alcohol may be relevant to the development of alcoholism. Although investigation of the function of brain ECM in alcohol abuse is still in early stages, a greater understanding of the interplay between ECM and alcohol might lead to novel therapeutic strategies for treating AUD. Copyright © 2016 by the Research Society on Alcoholism.

Effect of Binding Components in Complex Sample Matrices on Recovery in Direct Immersion Solid-Phase Microextraction: Friends or Foe?

PubMed

Alam, Md Nazmul; Pawliszyn, Janusz

2018-02-20

The development of matrix compatible coatings for solid-phase microextraction (SPME) has enabled direct extraction of analytes from complex sample matrices. The direct immersion (DI) mode of SPME when utilized in conjunction with such extraction phases facilitates extraction of a wide range of analytes from complex matrices without the incurrence of fouling or coating saturation. In this work, mathematical models and computational simulations were employed to investigate the effect of binding components present in complex samples on the recovery of small molecules varying in logP for extractions carried out using the direct immersion approach. The presented findings corroborate that the studied approach indeed enables the extraction of both polar and nonpolar analytes from complex matrices, provided a suitable sorbent is employed. Further results indicated that, in certain cases, the kinetics of extraction of a given analyte in its free form might be dependent on the desorption kinetics of their bound form from matrix components, which might lower total recoveries of analytes with high affinity for the matrix. However, the binding of analytes to matrix components also enables SPME to extract a balanced quantity of different logP analytes, facilitated by multiphase equilibria, with a single extraction device.

Rheological principles of development hetero-modulus and hetero-viscous complex materials with extreme dynamic strength

NASA Astrophysics Data System (ADS)

Gömze, L. A.; Gömze, L. N.

2017-02-01

Materials with different crystalline and morphological compositions have different chemical, physical, mechanical and rheological properties, including wear protection, melting temperature, module of elasticity and viscosity. Examining the material structures and behaviors of differentceramic bodies and CMCs under high speed collisions in several years the authors have understood the advantages of hetero-modulus and hetero-viscous complex material systems to absorb and dissipate the kinetic energy of objects during high speed collisions. Applying the rheo-mechanical principles the authors successfully developed a new family of hetero-modulus and hetero-viscous alumina matrix composite materials with extreme mechanical properties including dynamic strength. These new corundum-matrix composite materials reinforced with Si2ON 2, Si3N4 , SiAlON and AlN submicron and nanoparticles have excellent dynamic strength during collisions with high density metallic bodies with speeds about 1000 m/sec or more. At the same time in the alumina matrix composites can be observed a phase transformation of submicron and nanoparticles of alpha and beta silicone-nitride crystals into cubicc-Si3N4 diamond-like particles can be observed, when the high speed collision processes are taken place in vacuum or oxygen-free atmosphere. Using the rheological principles and the energy engorgement by fractures, heating and melting of components the authors successfully developed several new hetero-modulus, hetero-viscous and hetero-plastic complex materials. These materials generally are based on ceramic matrixes and components having different melting temperatures and modules of elasticity from low values like carbon and light metals (Mg, Al, Ti, Si) up to very high values like boride, nitride and carbide ceramics. Analytical methods applied in this research were scanning electron microscopy, X-ray diffractions and energy dispersive spectrometry. Digital image analysis was applied to microscopy results to enhance the results of transformations.

Development Status and Performance Comparisons of Environmental Barrier Coating Systems for SiCSiC Ceramic Matrix Composites

NASA Technical Reports Server (NTRS)

Zhu, Dongming; Harder, Bryan

2016-01-01

Environmental barrier coatings (EBC) and SiCSiC ceramic matrix composites (CMCs) will play a crucial role in future aircraft turbine engine systems, because of their ability to significantly increase engine operating temperatures, reduce engine weight and cooling requirements. This paper presents current NASA EBC-CMC development emphases including: the coating composition and processing improvements, laser high heat flux-thermal gradient thermo-mechanical fatigue - environmental testing methodology development, and property evaluations for next generation EBC-CMC systems. EBCs processed with various deposition techniques including Plasma Spray, Electron Beam - Physical Vapor Deposition, and Plasma Spray Physical Vapor Deposition (PS-PVD) will be particularly discussed. The testing results and demonstrations of advanced EBCs-CMCs in complex simulated engine thermal gradient cyclic fatigue, oxidizing-steam and CMAS environments will help provide insights into the coating development strategies to meet long-term engine component durability goals.

Development of a pericardial acellular matrix biomaterial: biochemical and mechanical effects of cell extraction.

PubMed

Courtman, D W; Pereira, C A; Kashef, V; McComb, D; Lee, J M; Wilson, G J

1994-06-01

There is evidence to suggest that the cellular components of homografts and bioprosthetic xenografts may contribute to calcification or immunogenic reactions. A four-step detergent and enzymatic extraction process has been developed to remove cellular components from bovine pericardial tissue. The process results in an acellular matrix material consisting primarily of elastin, insoluble collagen, and tightly bound glycosaminoglycans. Light and electron microscopy confirmed that nearly all cellular constituents are removed without ultrastructural evidence of damage to fibrous components. Collagen denaturation temperatures remained unaltered. Biochemical analysis confirmed the retention of collagen and elastin and some differential extraction of glycosaminoglycans. Low strain rate fracture testing and high strain rate viscoelastic characterization showed that, with the exception of slightly increased stress relaxation, the mechanical properties of the fresh tissue were preserved in the pericardial acellular matrix. Crosslinking of the material in glutaraldehyde or poly(glycidyl ether) produced mechanical changes consistent with the same treatments of fresh tissue. The pericardial acellular matrix is a promising approach to the production of biomaterials for heart valve or cardiovascular patching applications.

Preparation of monotectic alloys having a controlled microstructure by directional solidification under dopant-induced interface breakdown

NASA Technical Reports Server (NTRS)

Parr, R. A.; Johnston, M. H.; Mcclure, J. C.

1980-01-01

Monotectic alloys having aligned spherical particles of rods of the minor component dispersed in a matrix of the major component are prepared by forming a melt containing predetermined amounts of the major and minor components of a chosen monotectic system, providing in the melt a dopant capable of breaking down the liquid solid interface for the chosen alloy, and directionally solidfying the melt at a selected temperature gradient and a selected rate of movement of the liquid-solid interface (growth rate). Shaping of the minor component into spheres or rods and the spacing between them are controlled by the amount of dopant and the temperature gradient and growth rate values. Specific alloy systems include Al Bi, Al Pb and Zn Bi, using a transition element such as iron.

Research on criticality analysis method of CNC machine tools components under fault rate correlation

NASA Astrophysics Data System (ADS)

Gui-xiang, Shen; Xian-zhuo, Zhao; Zhang, Ying-zhi; Chen-yu, Han

2018-02-01

In order to determine the key components of CNC machine tools under fault rate correlation, a system component criticality analysis method is proposed. Based on the fault mechanism analysis, the component fault relation is determined, and the adjacency matrix is introduced to describe it. Then, the fault structure relation is hierarchical by using the interpretive structure model (ISM). Assuming that the impact of the fault obeys the Markov process, the fault association matrix is described and transformed, and the Pagerank algorithm is used to determine the relative influence values, combined component fault rate under time correlation can obtain comprehensive fault rate. Based on the fault mode frequency and fault influence, the criticality of the components under the fault rate correlation is determined, and the key components are determined to provide the correct basis for equationting the reliability assurance measures. Finally, taking machining centers as an example, the effectiveness of the method is verified.

An Alternative Method for Computing Mean and Covariance Matrix of Some Multivariate Distributions

ERIC Educational Resources Information Center

Radhakrishnan, R.; Choudhury, Askar

2009-01-01

Computing the mean and covariance matrix of some multivariate distributions, in particular, multivariate normal distribution and Wishart distribution are considered in this article. It involves a matrix transformation of the normal random vector into a random vector whose components are independent normal random variables, and then integrating…

Perturbative approach to covariance matrix of the matter power spectrum

NASA Astrophysics Data System (ADS)

Mohammed, Irshad; Seljak, Uroš; Vlah, Zvonimir

2017-04-01

We evaluate the covariance matrix of the matter power spectrum using perturbation theory up to dominant terms at 1-loop order and compare it to numerical simulations. We decompose the covariance matrix into the disconnected (Gaussian) part, trispectrum from the modes outside the survey (supersample variance) and trispectrum from the modes inside the survey, and show how the different components contribute to the overall covariance matrix. We find the agreement with the simulations is at a 10 per cent level up to k ˜ 1 h Mpc-1. We show that all the connected components are dominated by the large-scale modes (k < 0.1 h Mpc-1), regardless of the value of the wave vectors k, k΄ of the covariance matrix, suggesting that one must be careful in applying the jackknife or bootstrap methods to the covariance matrix. We perform an eigenmode decomposition of the connected part of the covariance matrix, showing that at higher k, it is dominated by a single eigenmode. The full covariance matrix can be approximated as the disconnected part only, with the connected part being treated as an external nuisance parameter with a known scale dependence, and a known prior on its variance for a given survey volume. Finally, we provide a prescription for how to evaluate the covariance matrix from small box simulations without the need to simulate large volumes.

Normal and Fibrotic Rat Livers Demonstrate Shear Strain Softening and Compression Stiffening: A Model for Soft Tissue Mechanics

PubMed Central

Cao, Xuan; van Oosten, Anne; Shenoy, Vivek B.; Janmey, Paul A.; Wells, Rebecca G.

2016-01-01

Tissues including liver stiffen and acquire more extracellular matrix with fibrosis. The relationship between matrix content and stiffness, however, is non-linear, and stiffness is only one component of tissue mechanics. The mechanical response of tissues such as liver to physiological stresses is not well described, and models of tissue mechanics are limited. To better understand the mechanics of the normal and fibrotic rat liver, we carried out a series of studies using parallel plate rheometry, measuring the response to compressive, extensional, and shear strains. We found that the shear storage and loss moduli G’ and G” and the apparent Young's moduli measured by uniaxial strain orthogonal to the shear direction increased markedly with both progressive fibrosis and increasing compression, that livers shear strain softened, and that significant increases in shear modulus with compressional stress occurred within a range consistent with increased sinusoidal pressures in liver disease. Proteoglycan content and integrin-matrix interactions were significant determinants of liver mechanics, particularly in compression. We propose a new non-linear constitutive model of the liver. A key feature of this model is that, while it assumes overall liver incompressibility, it takes into account water flow and solid phase compressibility. In sum, we report a detailed study of non-linear liver mechanics under physiological strains in the normal state, early fibrosis, and late fibrosis. We propose a constitutive model that captures compression stiffening, tension softening, and shear softening, and can be understood in terms of the cellular and matrix components of the liver. PMID:26735954

Losing the sugar coating: potential impact of perineuronal net abnormalities on interneurons in schizophrenia.

PubMed

Berretta, Sabina; Pantazopoulos, Harry; Markota, Matej; Brown, Christopher; Batzianouli, Eleni T

2015-09-01

Perineuronal nets (PNNs) were shown to be markedly altered in subjects with schizophrenia. In particular, decreases of PNNs have been detected in the amygdala, entorhinal cortex and prefrontal cortex. The formation of these specialized extracellular matrix (ECM) aggregates during postnatal development, their functions, and association with distinct populations of GABAergic interneurons, bear great relevance to the pathophysiology of schizophrenia. PNNs gradually mature in an experience-dependent manner during late stages of postnatal development, overlapping with the prodromal period/age of onset of schizophrenia. Throughout adulthood, PNNs regulate neuronal properties, including synaptic remodeling, cell membrane compartmentalization and subsequent regulation of glutamate receptors and calcium channels, and susceptibility to oxidative stress. With the present paper, we discuss evidence for PNN abnormalities in schizophrenia, the potential functional impact of such abnormalities on inhibitory circuits and, in turn, cognitive and emotion processing. We integrate these considerations with results from recent genetic studies showing genetic susceptibility for schizophrenia associated with genes encoding for PNN components, matrix-regulating molecules and immune system factors. Notably, the composition of PNNs is regulated dynamically in response to factors such as fear, reward, stress, and immune response. This regulation occurs through families of matrix metalloproteinases that cleave ECM components, altering their functions and affecting plasticity. Several metalloproteinases have been proposed as vulnerability factors for schizophrenia. We speculate that the physiological process of PNN remodeling may be disrupted in schizophrenia as a result of interactions between matrix remodeling processes and immune system dysregulation. In turn, these mechanisms may contribute to the dysfunction of GABAergic neurons. Copyright © 2015. Published by Elsevier B.V.

The structure and function of the pericellular matrix of articular cartilage.

PubMed

Wilusz, Rebecca E; Sanchez-Adams, Johannah; Guilak, Farshid

2014-10-01

Chondrocytes in articular cartilage are surrounded by a narrow pericellular matrix (PCM) that is both biochemically and biomechanically distinct from the extracellular matrix (ECM) of the tissue. While the PCM was first observed nearly a century ago, its role is still under investigation. In support of early hypotheses regarding its function, increasing evidence indicates that the PCM serves as a transducer of biochemical and biomechanical signals to the chondrocyte. Work over the past two decades has established that the PCM in adult tissue is defined biochemically by several molecular components, including type VI collagen and perlecan. On the other hand, the biomechanical properties of this structure have only recently been measured. Techniques such as micropipette aspiration, in situ imaging, computational modeling, and atomic force microscopy have determined that the PCM exhibits distinct mechanical properties as compared to the ECM, and that these properties are influenced by specific PCM components as well as disease state. Importantly, the unique relationships among the mechanical properties of the chondrocyte, PCM, and ECM in different zones of cartilage suggest that this region significantly influences the stress-strain environment of the chondrocyte. In this review, we discuss recent advances in the measurement of PCM mechanical properties and structure that further increase our understanding of PCM function. Taken together, these studies suggest that the PCM plays a critical role in controlling the mechanical environment and mechanobiology of cells in cartilage and other cartilaginous tissues, such as the meniscus or intervertebral disc. Copyright © 2014 International Society of Matrix Biology. Published by Elsevier B.V. All rights reserved.

Simultaneous determination and qualitative analysis of six types of components in Naoxintong capsule by miniaturized matrix solid-phase dispersion extraction coupled with ultra high-performance liquid chromatography with photodiode array detection and quadrupole time-of-flight mass spectrometry.

PubMed

Wang, Huilin; Jiang, Yan; Ding, Mingya; Li, Jin; Hao, Jia; He, Jun; Wang, Hui; Gao, Xiu-Mei; Chang, Yan-Xu

2018-02-03

A simple and effective sample preparation process based on miniaturized matrix solid-phase dispersion was developed for simultaneous determination of phenolic acids (gallic acid, chlorogenic acid, ferulic acid, 3,5-dicaffeoylqunic acid, 1,5-dicaffeoylqunic acid, rosmarinic acid, lithospermic acid, and salvianolic acid B), flavonoids (kaempferol-3-O-rutinoside, calycosin, and formononetin), lactones (ligustilide and butyllidephthalide), monoterpenoids (paeoniflorin), phenanthraquinones (cryptotanshinone), and furans (5-hydroxymethylfurfural) in Naoxintong capsule by ultra high-performance liquid chromatography. The optimized condition was that 25 mg Naoxintong powder was blended homogeneously with 100 mg Florisil PR for 4 min. One milliliter of methanol/water (75:25, v/v) acidified by 0.05% formic acid was selected to elute all components. It was found that the recoveries of the six types of components ranged from 61.36 to 96.94%. The proposed miniaturized matrix solid-phase dispersion coupled with ultra high-performance liquid chromatography was successfully applied to simultaneous determination of the six types of components in Naoxintong capsules. The results demonstrated that the proposed miniaturized matrix solid-phase dispersion coupled with ultra high-performance liquid chromatography could be used as an environmentally friendly tool for the extraction and determination of multiple bioactive components in natural products. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Multicomponent diffusion in basaltic melts at 1350 °C

NASA Astrophysics Data System (ADS)

Guo, Chenghuan; Zhang, Youxue

2018-05-01

Nine successful diffusion couple experiments were conducted in an 8-component SiO2-TiO2-Al2O3-FeO-MgO-CaO-Na2O-K2O system at ∼1350 °C and at 1 GPa, to study multicomponent diffusion in basaltic melts. At least 3 traverses were measured to obtain diffusion profiles for each experiment. Multicomponent diffusion matrix at 1350 °C was obtained by simultaneously fitting diffusion profiles of diffusion couple experiments. Furthermore, in order to better constrain the diffusion matrix and reconcile mineral dissolution data, mineral dissolution experiments in the literature and diffusion couple experiments from this study, were fit together. All features of diffusion profiles in both diffusion couple and mineral dissolution experiments were well reproduced by the diffusion matrix. Diffusion mechanism is inferred from eigenvectors of the diffusion matrix, and it shows that the diffusive exchange between network-formers SiO2 and Al2O3 is the slowest, the exchange of SiO2 with other oxide components is the second slowest with an eigenvalue that is only ∼10% larger, then the exchange between divalent oxide components and all the other oxide components is the third slowest with an eigenvalue that is twice the smallest eigenvalue, then the exchange of FeO + K2O with all the other oxide components is the fourth slowest with an eigenvalue that is 5 times the smallest eigenvalue, then the exchange of MgO with FeO + CaO is the third fastest with an eigenvalue that is 6.3 times the smallest eigenvalue, then the exchange of CaO + K2O with all the other oxide components is the second fastest with an eigenvalue that is 7.5 times the smallest eigenvalue, and the exchange of Na2O with all other oxide components is the fastest with an eigenvalue that is 31 times the smallest eigenvalue. The slowest and fastest eigenvectors are consistent with those for simpler systems in most literature. The obtained diffusion matrix was successfully applied to predict diffusion profiles during mineral dissolution in basaltic melts.

Basic components of connective tissues and extracellular matrix: elastin, fibrillin, fibulins, fibrinogen, fibronectin, laminin, tenascins and thrombospondins.

PubMed

Halper, Jaroslava; Kjaer, Michael

2014-01-01

Collagens are the most abundant components of the extracellular matrix and many types of soft tissues. Elastin is another major component of certain soft tissues, such as arterial walls and ligaments. Many other molecules, though lower in quantity, function as essential components of the extracellular matrix in soft tissues. Some of these are reviewed in this chapter. Besides their basic structure, biochemistry and physiology, their roles in disorders of soft tissues are discussed only briefly as most chapters in this volume deal with relevant individual compounds. Fibronectin with its muldomain structure plays a role of "master organizer" in matrix assembly as it forms a bridge between cell surface receptors, e.g., integrins, and compounds such collagen, proteoglycans and other focal adhesion molecules. It also plays an essential role in the assembly of fibrillin-1 into a structured network. Laminins contribute to the structure of the extracellular matrix (ECM) and modulate cellular functions such as adhesion, differentiation, migration, stability of phenotype, and resistance towards apoptosis. Though the primary role of fibrinogen is in clot formation, after conversion to fibrin by thrombin, it also binds to a variety of compounds, particularly to various growth factors, and as such fibrinogen is a player in cardiovascular and extracellular matrix physiology. Elastin, an insoluble polymer of the monomeric soluble precursor tropoelastin, is the main component of elastic fibers in matrix tissue where it provides elastic recoil and resilience to a variety of connective tissues, e.g., aorta and ligaments. Elastic fibers regulate activity of TGFβs through their association with fibrillin microfibrils. Elastin also plays a role in cell adhesion, cell migration, and has the ability to participate in cell signaling. Mutations in the elastin gene lead to cutis laxa. Fibrillins represent the predominant core of the microfibrils in elastic as well as non-elastic extracellular matrixes, and interact closely with tropoelastin and integrins. Not only do microfibrils provide structural integrity of specific organ systems, but they also provide a scaffold for elastogenesis in elastic tissues. Fibrillin is important for the assembly of elastin into elastic fibers. Mutations in the fibrillin-1 gene are closely associated with Marfan syndrome. Fibulins are tightly connected with basement membranes, elastic fibers and other components of extracellular matrix and participate in formation of elastic fibers. Tenascins are ECM polymorphic glycoproteins found in many connective tissues in the body. Their expression is regulated by mechanical stress both during development and in adulthood. Tenascins mediate both inflammatory and fibrotic processes to enable effective tissue repair and play roles in pathogenesis of Ehlers-Danlos, heart disease, and regeneration and recovery of musculo-tendinous tissue. One of the roles of thrombospondin 1 is activation of TGFβ. Increased expression of thrombospondin and TGFβ activity was observed in fibrotic skin disorders such as keloids and scleroderma. Cartilage oligomeric matrix protein (COMP) or thrombospondin-5 is primarily present in the cartilage. High levels of COMP are present in fibrotic scars and systemic sclerosis of the skin, and in tendon, especially with physical activity, loading and post-injury. It plays a role in vascular wall remodeling and has been found in atherosclerotic plaques as well.

Colonization of bone matrices by cellular components

NASA Astrophysics Data System (ADS)

Shchelkunova, E. I.; Voropaeva, A. A.; Korel, A. V.; Mayer, D. A.; Podorognaya, V. T.; Kirilova, I. A.

2017-09-01

Practical surgery, traumatology, orthopedics, and oncology require bioengineered constructs suitable for replacement of large-area bone defects. Only rigid/elastic matrix containing recipient's bone cells capable of mitosis, differentiation, and synthesizing extracellular matrix that supports cell viability can comply with these requirements. Therefore, the development of the techniques to produce structural and functional substitutes, whose three-dimensional structure corresponds to the recipient's damaged tissues, is the main objective of tissue engineering. This is achieved by developing tissue-engineering constructs represented by cells placed on the matrices. Low effectiveness of carrier matrix colonization with cells and their uneven distribution is one of the major problems in cell culture on various matrixes. In vitro studies of the interactions between cells and material, as well as the development of new techniques for scaffold colonization by cellular components are required to solve this problem.

HIGH DIMENSIONAL COVARIANCE MATRIX ESTIMATION IN APPROXIMATE FACTOR MODELS.

PubMed

Fan, Jianqing; Liao, Yuan; Mincheva, Martina

2011-01-01

The variance covariance matrix plays a central role in the inferential theories of high dimensional factor models in finance and economics. Popular regularization methods of directly exploiting sparsity are not directly applicable to many financial problems. Classical methods of estimating the covariance matrices are based on the strict factor models, assuming independent idiosyncratic components. This assumption, however, is restrictive in practical applications. By assuming sparse error covariance matrix, we allow the presence of the cross-sectional correlation even after taking out common factors, and it enables us to combine the merits of both methods. We estimate the sparse covariance using the adaptive thresholding technique as in Cai and Liu (2011), taking into account the fact that direct observations of the idiosyncratic components are unavailable. The impact of high dimensionality on the covariance matrix estimation based on the factor structure is then studied.

Assembly and Development of the Pseudomonas aeruginosa Biofilm Matrix

PubMed Central

Ma, Luyan; Conover, Matthew; Lu, Haiping; Parsek, Matthew R.; Bayles, Kenneth; Wozniak, Daniel J.

2009-01-01

Virtually all cells living in multicellular structures such as tissues and organs are encased in an extracellular matrix. One of the most important features of a biofilm is the extracellular polymeric substance that functions as a matrix, holding bacterial cells together. Yet very little is known about how the matrix forms or how matrix components encase bacteria during biofilm development. Pseudomonas aeruginosa forms environmentally and clinically relevant biofilms and is a paradigm organism for the study of biofilms. The extracellular polymeric substance of P. aeruginosa biofilms is an ill-defined mix of polysaccharides, nucleic acids, and proteins. Here, we directly visualize the product of the polysaccharide synthesis locus (Psl exopolysaccharide) at different stages of biofilm development. During attachment, Psl is anchored on the cell surface in a helical pattern. This promotes cell–cell interactions and assembly of a matrix, which holds bacteria in the biofilm and on the surface. Chemical dissociation of Psl from the bacterial surface disrupted the Psl matrix as well as the biofilm structure. During biofilm maturation, Psl accumulates on the periphery of 3-D-structured microcolonies, resulting in a Psl matrix-free cavity in the microcolony center. At the dispersion stage, swimming cells appear in this matrix cavity. Dead cells and extracellular DNA (eDNA) are also concentrated in the Psl matrix-free area. Deletion of genes that control cell death and autolysis affects the formation of the matrix cavity and microcolony dispersion. These data provide a mechanism for how P. aeruginosa builds a matrix and subsequently a cavity to free a portion of cells for seeding dispersal. Direct visualization reveals that Psl is a key scaffolding matrix component and opens up avenues for therapeutics of biofilm-related complications. PMID:19325879

Assembly and development of the Pseudomonas aeruginosa biofilm matrix.

PubMed

Ma, Luyan; Conover, Matthew; Lu, Haiping; Parsek, Matthew R; Bayles, Kenneth; Wozniak, Daniel J

2009-03-01

Virtually all cells living in multicellular structures such as tissues and organs are encased in an extracellular matrix. One of the most important features of a biofilm is the extracellular polymeric substance that functions as a matrix, holding bacterial cells together. Yet very little is known about how the matrix forms or how matrix components encase bacteria during biofilm development. Pseudomonas aeruginosa forms environmentally and clinically relevant biofilms and is a paradigm organism for the study of biofilms. The extracellular polymeric substance of P. aeruginosa biofilms is an ill-defined mix of polysaccharides, nucleic acids, and proteins. Here, we directly visualize the product of the polysaccharide synthesis locus (Psl exopolysaccharide) at different stages of biofilm development. During attachment, Psl is anchored on the cell surface in a helical pattern. This promotes cell-cell interactions and assembly of a matrix, which holds bacteria in the biofilm and on the surface. Chemical dissociation of Psl from the bacterial surface disrupted the Psl matrix as well as the biofilm structure. During biofilm maturation, Psl accumulates on the periphery of 3-D-structured microcolonies, resulting in a Psl matrix-free cavity in the microcolony center. At the dispersion stage, swimming cells appear in this matrix cavity. Dead cells and extracellular DNA (eDNA) are also concentrated in the Psl matrix-free area. Deletion of genes that control cell death and autolysis affects the formation of the matrix cavity and microcolony dispersion. These data provide a mechanism for how P. aeruginosa builds a matrix and subsequently a cavity to free a portion of cells for seeding dispersal. Direct visualization reveals that Psl is a key scaffolding matrix component and opens up avenues for therapeutics of biofilm-related complications.

CPDES3: A preconditioned conjugate gradient solver for linear asymmetric matrix equations arising from coupled partial differential equations in three dimensions

NASA Astrophysics Data System (ADS)

Anderson, D. V.; Koniges, A. E.; Shumaker, D. E.

1988-11-01

Many physical problems require the solution of coupled partial differential equations on three-dimensional domains. When the time scales of interest dictate an implicit discretization of the equations a rather complicated global matrix system needs solution. The exact form of the matrix depends on the choice of spatial grids and on the finite element or finite difference approximations employed. CPDES3 allows each spatial operator to have 7, 15, 19, or 27 point stencils and allows for general couplings between all of the component PDE's and it automatically generates the matrix structures needed to perform the algorithm. The resulting sparse matrix equation is solved by either the preconditioned conjugate gradient (CG) method or by the preconditioned biconjugate gradient (BCG) algorithm. An arbitrary number of component equations are permitted only limited by available memory. In the sub-band representation used, we generate an algorithm that is written compactly in terms of indirect induces which is vectorizable on some of the newer scientific computers.

CPDES2: A preconditioned conjugate gradient solver for linear asymmetric matrix equations arising from coupled partial differential equations in two dimensions

NASA Astrophysics Data System (ADS)

Anderson, D. V.; Koniges, A. E.; Shumaker, D. E.

1988-11-01

Many physical problems require the solution of coupled partial differential equations on two-dimensional domains. When the time scales of interest dictate an implicit discretization of the equations a rather complicated global matrix system needs solution. The exact form of the matrix depends on the choice of spatial grids and on the finite element or finite difference approximations employed. CPDES2 allows each spatial operator to have 5 or 9 point stencils and allows for general couplings between all of the component PDE's and it automatically generates the matrix structures needed to perform the algorithm. The resulting sparse matrix equation is solved by either the preconditioned conjugate gradient (CG) method or by the preconditioned biconjugate gradient (BCG) algorithm. An arbitrary number of component equations are permitted only limited by available memory. In the sub-band representation used, we generate an algorithm that is written compactly in terms of indirect indices which is vectorizable on some of the newer scientific computers.

Material selection and assembly method of battery pack for compact electric vehicle

NASA Astrophysics Data System (ADS)

Lewchalermwong, N.; Masomtob, M.; Lailuck, V.; Charoenphonphanich, C.

2018-01-01

Battery packs become the key component in electric vehicles (EVs). The main costs of which are battery cells and assembling processes. The battery cell is indeed priced from battery manufacturers while the assembling cost is dependent on battery pack designs. Battery pack designers need overall cost as cheap as possible, but it still requires high performance and more safety. Material selection and assembly method as well as component design are very important to determine the cost-effectiveness of battery modules and battery packs. Therefore, this work presents Decision Matrix, which can aid in the decision-making process of component materials and assembly methods for a battery module design and a battery pack design. The aim of this study is to take the advantage of incorporating Architecture Analysis method into decision matrix methods by capturing best practices for conducting design architecture analysis in full account of key design components critical to ensure efficient and effective development of the designs. The methodology also considers the impacts of choice-alternatives along multiple dimensions. Various alternatives for materials and assembly techniques of battery pack are evaluated, and some sample costs are presented. Due to many components in the battery pack, only seven components which are positive busbar and Z busbar are represented in this paper for using decision matrix methods.

Science-Economy-Technology Concordance Matrix for Development and Implementation of Regional Smart Specializations in the Silesian Voivodeship, Poland

PubMed Central

Smoliński, Adam; Bondaruk, Jan; Pichlak, Magdalena; Trząski, Leszek; Uszok, Elżbieta

2015-01-01

The regional smart specializations include the innovative activities within a common science-economy-technology sector, which open the opportunities to gain a competitive advantage. The original procedure of science-economy-technology concordance matrix development on an example of smart specializations of the Silesian Voivodeship was presented in the paper. The procedure developed includes recognition of the research and economic components of the regional smart specialization and the connection between the economic components of the regional specialization and the technological innovation through the international patent classification. It also comprises recognition of key enabling technologies (KETs) and high technologies (of high R&D intensity) other than KET in the economic and technological dimensions of innovation as well as the high R&D intensity services in the economic dimension of innovation. The in-depth expert analyses with the application of the Delphi method were also taken into account. The methodological approach developed and the visualization method applied are both of cognitive and practical importance since they contribute significantly to the creation of efficient development policies, to the enhancement and facilitation of cross-sectoral cooperation, and to the focusing on the fields of key importance in terms of the competitive advantage of a region. PMID:26697528

Science-Economy-Technology Concordance Matrix for Development and Implementation of Regional Smart Specializations in the Silesian Voivodeship, Poland.

PubMed

Smoliński, Adam; Bondaruk, Jan; Pichlak, Magdalena; Trząski, Leszek; Uszok, Elżbieta

2015-01-01

The regional smart specializations include the innovative activities within a common science-economy-technology sector, which open the opportunities to gain a competitive advantage. The original procedure of science-economy-technology concordance matrix development on an example of smart specializations of the Silesian Voivodeship was presented in the paper. The procedure developed includes recognition of the research and economic components of the regional smart specialization and the connection between the economic components of the regional specialization and the technological innovation through the international patent classification. It also comprises recognition of key enabling technologies (KETs) and high technologies (of high R&D intensity) other than KET in the economic and technological dimensions of innovation as well as the high R&D intensity services in the economic dimension of innovation. The in-depth expert analyses with the application of the Delphi method were also taken into account. The methodological approach developed and the visualization method applied are both of cognitive and practical importance since they contribute significantly to the creation of efficient development policies, to the enhancement and facilitation of cross-sectoral cooperation, and to the focusing on the fields of key importance in terms of the competitive advantage of a region.

ControlShell: A real-time software framework

NASA Technical Reports Server (NTRS)

Schneider, Stanley A.; Chen, Vincent W.; Pardo-Castellote, Gerardo

1994-01-01

The ControlShell system is a programming environment that enables the development and implementation of complex real-time software. It includes many building tools for complex systems, such as a graphical finite state machine (FSM) tool to provide strategic control. ControlShell has a component-based design, providing interface definitions and mechanisms for building real-time code modules along with providing basic data management. Some of the system-building tools incorporated in ControlShell are a graphical data flow editor, a component data requirement editor, and a state-machine editor. It also includes a distributed data flow package, an execution configuration manager, a matrix package, and an object database and dynamic binding facility. This paper presents an overview of ControlShell's architecture and examines the functions of several of its tools.

Integrated Droplet-Based Microextraction with ESI-MS for Removal of Matrix Interference in Single-Cell Analysis.

PubMed

Zhang, Xiao-Chao; Wei, Zhen-Wei; Gong, Xiao-Yun; Si, Xing-Yu; Zhao, Yao-Yao; Yang, Cheng-Dui; Zhang, Si-Chun; Zhang, Xin-Rong

2016-04-29

Integrating droplet-based microfluidics with mass spectrometry is essential to high-throughput and multiple analysis of single cells. Nevertheless, matrix effects such as the interference of culture medium and intracellular components influence the sensitivity and the accuracy of results in single-cell analysis. To resolve this problem, we developed a method that integrated droplet-based microextraction with single-cell mass spectrometry. Specific extraction solvent was used to selectively obtain intracellular components of interest and remove interference of other components. Using this method, UDP-Glc-NAc, GSH, GSSG, AMP, ADP and ATP were successfully detected in single MCF-7 cells. We also applied the method to study the change of unicellular metabolites in the biological process of dysfunctional oxidative phosphorylation. The method could not only realize matrix-free, selective and sensitive detection of metabolites in single cells, but also have the capability for reliable and high-throughput single-cell analysis.

Methods and apparatuses for the development of microstructured nuclear fuels

DOEpatents

Jarvinen, Gordon D [Los Alamos, NM; Carroll, David W [Los Alamos, NM; Devlin, David J [Santa Fe, NM

2009-04-21

Microstructured nuclear fuel adapted for nuclear power system use includes fissile material structures of micrometer-scale dimension dispersed in a matrix material. In one method of production, fissile material particles are processed in a chemical vapor deposition (CVD) fluidized-bed reactor including a gas inlet for providing controlled gas flow into a particle coating chamber, a lower bed hot zone region to contain powder, and an upper bed region to enable powder expansion. At least one pneumatic or electric vibrator is operationally coupled to the particle coating chamber for causing vibration of the particle coater to promote uniform powder coating within the particle coater during fuel processing. An exhaust associated with the particle coating chamber and can provide a port for placement and removal of particles and powder. During use of the fuel in a nuclear power reactor, fission products escape from the fissile material structures and come to rest in the matrix material. After a period of use in a nuclear power reactor and subsequent cooling, separation of the fissile material from the matrix containing the embedded fission products will provide an efficient partitioning of the bulk of the fissile material from the fission products. The fissile material can be reused by incorporating it into new microstructured fuel. The fission products and matrix material can be incorporated into a waste form for disposal or processed to separate valuable components from the fission products mixture.

Kindler surprise: mutations in a novel actin-associated protein cause Kindler syndrome.

PubMed

White, Sharon J; McLean, W H Irwin

2005-06-01

Kindler syndrome is an autosomal recessive genodermatosis characterized by acral blistering in neonates and diffuse, progressive poikiloderma in later life. Other clinical features include photosensitivity, premature skin ageing and severe periodontal disease. Two groups have recently shown that the molecular basis of Kindler syndrome is loss of a novel epidermal protein, kindlin-1, encoded by the gene KIND1. Two additional kindlin proteins, kindlin-2 and kindlin-3, have also been described. Kindlin-1 is considered to be a component in the linkage of the actin cytoskeleton to the extracellular matrix and as such is proposed to have both structural and cell-signalling functions. Kindler syndrome is therefore the first skin fragility syndrome due to disruption of the actin-extracellular matrix system.

Pyrolysis and Matrix-Isolation FTIR of Acetoin

NASA Astrophysics Data System (ADS)

Cole, Sarah; Ellis, Martha; Sowards, John; McCunn, Laura R.

2017-06-01

Acetoin, CH_3C(O)CH(OH)CH_3, is an additive used in foods and cigarettes as well as a common component of biomass pyrolysate during the production of biofuels, yet little is known about its thermal decomposition mechanism. In order to identify thermal decomposition products of acetoin, a gas-phase mixture of approximately 0.3% acetoin in argon was subject to pyrolysis in a resistively heated SiC microtubular reactor at 1100-1500 K. Matrix-isolation FTIR spectroscopy was used to identify pyrolysis products. Many products were observed in analysis of the spectra, including acetylene, propyne, ethylene, and vinyl alcohol. These results provide clues to the overall mechanism of thermal decomposition and are important for predicting emissions from many industrial and residential processes.

Down the Rabbit Hole: Using "The Matrix" to Reflect on Teacher Education

ERIC Educational Resources Information Center

Batchelor, Katherine; Sander, Scott A.

2017-01-01

In this article we use "The Matrix" movie as a heuristic device that offers two possibilities for conceptualizing teacher education: as a mirror (looking at ourselves) and as a window (looking at teacher education). We begin by sharing our interests and reason for using self-study while examining the components of "The Matrix,"…

User and technical documentation

NASA Astrophysics Data System (ADS)

1988-09-01

The program LIBRATE calculates velocities for trajectories from low earth orbit (LEO) to four of the five libration points (L2, L3, L4, and L5), and from low lunar orbit (LLO) to libration points L1 and L2. The flight to be analyzed departs from a circular orbit of any altitude and inclination about the Earth or Moon and finishes in a circular orbit about the Earth at the desired libration point within a specified flight time. This program produces a matrix of the delta V's needed to complete the desired flight. The user specifies the departure orbit, and the maximum flight time. A matrix is then developed with 10 inclinations, ranging from 0 to 90 degrees, forming the columns, and 19 possible flight times, ranging from the flight time (input) to 36 hours less than the input value, in decrements of 2 hours, forming the rows. This matrix is presented in three different reports including the total delta V's, and both of the delta V components discussed. The input required from the user to define the flight is discussed. The contents of the three reports that are produced as outputs are also described. The instructions are also included which are needed to execute the program.

Immunohistochemical expression of matrix metalloproteinase 13 in chronic periodontitis.

PubMed

Nagasupriya, Alapati; Rao, Donimukkala Bheemalingeswara; Ravikanth, Manyam; Kumar, Nalabolu Govind; Ramachandran, Cinnamanoor Rajmani; Saraswathi, Thillai Rajashekaran

2014-01-01

The extracellular matrix is a complex integrated system responsible for the physiologic properties of connective tissue. Collagen is the major extracellular component that is altered in pathologic conditions, mainly periodontitis. The destruction involves proteolytic enzymes, primarily matrix metalloproteinases (MMPs), which play a key role in mediating and regulating the connective tissue destruction in periodontitis. The study group included 40 patients with clinically diagnosed chronic periodontitis. The control group included 20 patients with clinically normal gingiva covering impacted third molars undergoing extraction or in areas where crown-lengthening procedures were performed. MMP-13 expression was demonstrated using immunohistochemistry in all the gingival biopsies, and the data were analyzed statistically. MMP-13 expression was observed more in chronic periodontitis when compared with normal gingiva. MMP-13 expression was expressed by fibroblasts, lymphocytes, macrophages, plasma cells, and basal cells of the sulcular epithelium. Comparative evaluation of all the clinical and histologic parameters with MMP-13 expression showed high statistical significance with Spearman correlation coefficient. Elevated levels of MMP-13 may play a role in the pathogenesis of chronic periodontitis. There is a direct correlation of increased expression of MMP-13 with various clinical and histologic parameters in disease severity.

Ceramic matrix composite article and process of fabricating a ceramic matrix composite article

DOEpatents

Cairo, Ronald Robert; DiMascio, Paul Stephen; Parolini, Jason Robert

2016-01-12

A ceramic matrix composite article and a process of fabricating a ceramic matrix composite are disclosed. The ceramic matrix composite article includes a matrix distribution pattern formed by a manifold and ceramic matrix composite plies laid up on the matrix distribution pattern, includes the manifold, or a combination thereof. The manifold includes one or more matrix distribution channels operably connected to a delivery interface, the delivery interface configured for providing matrix material to one or more of the ceramic matrix composite plies. The process includes providing the manifold, forming the matrix distribution pattern by transporting the matrix material through the manifold, and contacting the ceramic matrix composite plies with the matrix material.

Statistics of partially-polarized fields: beyond the Stokes vector and coherence matrix

NASA Astrophysics Data System (ADS)

Charnotskii, Mikhail

2017-08-01

Traditionally, the partially-polarized light is characterized by the four Stokes parameters. Equivalent description is also provided by correlation tensor of the optical field. These statistics specify only the second moments of the complex amplitudes of the narrow-band two-dimensional electric field of the optical wave. Electric field vector of the random quasi monochromatic wave is a nonstationary oscillating two-dimensional real random variable. We introduce a novel statistical description of these partially polarized waves: the Period-Averaged Probability Density Function (PA-PDF) of the field. PA-PDF contains more information on the polarization state of the field than the Stokes vector. In particular, in addition to the conventional distinction between the polarized and depolarized components of the field PA-PDF allows to separate the coherent and fluctuating components of the field. We present several model examples of the fields with identical Stokes vectors and very distinct shapes of PA-PDF. In the simplest case of the nonstationary, oscillating normal 2-D probability distribution of the real electrical field and stationary 4-D probability distribution of the complex amplitudes, the newly-introduced PA-PDF is determined by 13 parameters that include the first moments and covariance matrix of the quadrature components of the oscillating vector field.

Mechanics of a fiber network within a non-fibrillar matrix: model and comparison with collagen-agarose co-gels

PubMed Central

Lake, Spencer P.; Hadi, Mohammad F.; Lai, Victor K.; Barocas, Victor H.

2013-01-01

While collagen is recognized as the predominant mechanical component of soft connective tissues, the role of the non-fibrillar matrix (NFM) is less well understood. Even model systems, such as the collagen-agarose co-gel, can exhibit complex behavior, making it difficult to identify relative contributions of specific tissue constituents. In the present study, we developed a two-component microscale model of collagen-agarose tissue analogs and used it to elucidate the interaction between collagen and NFM in uniaxial tension. Collagen fibers were represented with Voronoi networks, and the NFM was modeled as a neo-Hookean solid. Model predictions of total normal stress and Poisson’s ratio matched experimental observations well (including high Poisson’s values of ~3), and the addition of NFM led to composition-dependent decreases in volume change and increases in fiber stretch. Because the NFM was more resistant to volume change than the fiber network, extension of the composite led to pressurization of the NFM. Within a specific range of parameter values (low shear modulus and moderate Poisson’s ratio), the magnitude of the reaction force decreased relative to this pressurization component resulting in a negative (compressive) NFM stress in the loading direction, even though the composite tissue was in tension. PMID:22565816

Sparse representation of whole-brain fMRI signals for identification of functional networks.

PubMed

Lv, Jinglei; Jiang, Xi; Li, Xiang; Zhu, Dajiang; Chen, Hanbo; Zhang, Tuo; Zhang, Shu; Hu, Xintao; Han, Junwei; Huang, Heng; Zhang, Jing; Guo, Lei; Liu, Tianming

2015-02-01

There have been several recent studies that used sparse representation for fMRI signal analysis and activation detection based on the assumption that each voxel's fMRI signal is linearly composed of sparse components. Previous studies have employed sparse coding to model functional networks in various modalities and scales. These prior contributions inspired the exploration of whether/how sparse representation can be used to identify functional networks in a voxel-wise way and on the whole brain scale. This paper presents a novel, alternative methodology of identifying multiple functional networks via sparse representation of whole-brain task-based fMRI signals. Our basic idea is that all fMRI signals within the whole brain of one subject are aggregated into a big data matrix, which is then factorized into an over-complete dictionary basis matrix and a reference weight matrix via an effective online dictionary learning algorithm. Our extensive experimental results have shown that this novel methodology can uncover multiple functional networks that can be well characterized and interpreted in spatial, temporal and frequency domains based on current brain science knowledge. Importantly, these well-characterized functional network components are quite reproducible in different brains. In general, our methods offer a novel, effective and unified solution to multiple fMRI data analysis tasks including activation detection, de-activation detection, and functional network identification. Copyright © 2014 Elsevier B.V. All rights reserved.

Prepreg and Melt Infiltration Technology Developed for Affordable, Robust Manufacturing of Ceramic Matrix Composites

NASA Technical Reports Server (NTRS)

Singh, Mrityunjay; Petko, Jeannie F.

2004-01-01

Affordable fiber-reinforced ceramic matrix composites with multifunctional properties are critically needed for high-temperature aerospace and space transportation applications. These materials have various applications in advanced high-efficiency and high-performance engines, airframe and propulsion components for next-generation launch vehicles, and components for land-based systems. A number of these applications require materials with specific functional characteristics: for example, thick component, hybrid layups for environmental durability and stress management, and self-healing and smart composite matrices. At present, with limited success and very high cost, traditional composite fabrication technologies have been utilized to manufacture some large, complex-shape components of these materials. However, many challenges still remain in developing affordable, robust, and flexible manufacturing technologies for large, complex-shape components with multifunctional properties. The prepreg and melt infiltration (PREMI) technology provides an affordable and robust manufacturing route for low-cost, large-scale production of multifunctional ceramic composite components.

Casting of weldable graphite/magnesium metal matrix composites with built-in metallic inserts

NASA Technical Reports Server (NTRS)

Lee, Jonathan A.; Kashalikar, Uday; Majkowski, Patricia

1994-01-01

Technology innovations directed at the advanced development of a potentially low cost and weldable graphite/magnesium metal matrix composites (MMC) through near net shape pressure casting are described. These MMC components uniquely have built-in metallic inserts to provide an innovative approach for joining or connecting other MMC components through conventional joining techniques such as welding, brazing, mechanical fasteners, etc. Moreover, the metallic inserts trapped within the MMC components can be made to transfer the imposed load efficiently to the continuous graphite fiber reinforcement thus producing stronger, stiffer, and more reliable MMC components. The use of low pressure near net shape casting is economical compared to other MMC fabrication processes. These castable and potentially weldable MMC components can provide great payoffs in terms of high strength, high stiffness, low thermal expansion, lightweight, and easily joinable MMC components for several future NASA space structural, industrial, and commercial applications.

Direct S -matrix calculation for diffractive structures and metasurfaces

NASA Astrophysics Data System (ADS)

Shcherbakov, Alexey A.; Stebunov, Yury V.; Baidin, Denis F.; Kämpfe, Thomas; Jourlin, Yves

2018-06-01

The paper presents a derivation of analytical components of S matrices for arbitrary planar diffractive structures and metasurfaces in the Fourier domain. The attained general formulas for S -matrix components can be applied within both formulations in the Cartesian and curvilinear metric. A numerical method based on these results can benefit from all previous improvements of the Fourier domain methods. In addition, we provide expressions for S -matrix calculation in the case of periodically corrugated layers of two-dimensional materials, which are valid for arbitrary corrugation depth-to-period ratios. As an example, the derived equations are used to simulate resonant grating excitation of graphene plasmons and the impact of a silica interlayer on corresponding reflection curves.

Iris recognition based on robust principal component analysis

NASA Astrophysics Data System (ADS)

Karn, Pradeep; He, Xiao Hai; Yang, Shuai; Wu, Xiao Hong

2014-11-01

Iris images acquired under different conditions often suffer from blur, occlusion due to eyelids and eyelashes, specular reflection, and other artifacts. Existing iris recognition systems do not perform well on these types of images. To overcome these problems, we propose an iris recognition method based on robust principal component analysis. The proposed method decomposes all training images into a low-rank matrix and a sparse error matrix, where the low-rank matrix is used for feature extraction. The sparsity concentration index approach is then applied to validate the recognition result. Experimental results using CASIA V4 and IIT Delhi V1iris image databases showed that the proposed method achieved competitive performances in both recognition accuracy and computational efficiency.

Identification of Novel Components Influencing Colonization Factor Antigen I Expression in Enterotoxigenic Escherichia coli

PubMed Central

Haines, Sara; Gautheron, Sylviane; Nasser, William; Renauld-Mongénie, Geneviève

2015-01-01

Colonization factors (CFs) mediate early adhesion of Enterotoxigenic Escherichia coli (ETEC) in the small intestine. Environmental signals including bile, glucose, and contact with epithelial cells have previously been shown to modulate CF expression in a strain dependent manner. To identify novel components modulating CF surface expression, 20 components relevant to the intestinal environment were selected for evaluation. These included mucin, bicarbonate, norepinephrine, lincomycin, carbon sources, and cations. Effects of individual components on surface expression of the archetype CF, CFA/I, were screened using a fractional factorial Hadamard matrix incorporating 24 growth conditions. As most CFs agglutinate erythrocytes, surface expression was evaluated by mannose resistant hemagglutination. Seven components, including porcine gastric mucin, lincomycin, glutamine, and glucose were found to induce CFA/I surface expression in vitro in a minimal media while five others were inhibitory, including leucine and 1,10-phenanthroline. To further explore the effect of components positively influencing CFA/I surface expression, a response surface methodology (RSM) was designed incorporating 36 growth conditions. The optimum concentration for each component was identified, thereby generating a novel culture media, SP1, for CFA/I expression. CFs closely related to CFA/I, including CS4 and CS14 were similarly induced in SP1 media. Other epidemiologically relevant CFs were also induced when compared to the level obtained in minimal media. These results indicate that although CF surface expression is complex and highly variable among strains, the CF response can be predicted for closely related strains. A novel culture media inducing CFs in the CF5a group was successfully identified. In addition, mucin was found to positively influence CF expression in strains expressing either CFA/I or CS1 and CS3, and may function as a common environmental cue. PMID:26517723

Identification of Novel Components Influencing Colonization Factor Antigen I Expression in Enterotoxigenic Escherichia coli.

PubMed

Haines, Sara; Gautheron, Sylviane; Nasser, William; Renauld-Mongénie, Geneviève

2015-01-01

Colonization factors (CFs) mediate early adhesion of Enterotoxigenic Escherichia coli (ETEC) in the small intestine. Environmental signals including bile, glucose, and contact with epithelial cells have previously been shown to modulate CF expression in a strain dependent manner. To identify novel components modulating CF surface expression, 20 components relevant to the intestinal environment were selected for evaluation. These included mucin, bicarbonate, norepinephrine, lincomycin, carbon sources, and cations. Effects of individual components on surface expression of the archetype CF, CFA/I, were screened using a fractional factorial Hadamard matrix incorporating 24 growth conditions. As most CFs agglutinate erythrocytes, surface expression was evaluated by mannose resistant hemagglutination. Seven components, including porcine gastric mucin, lincomycin, glutamine, and glucose were found to induce CFA/I surface expression in vitro in a minimal media while five others were inhibitory, including leucine and 1,10-phenanthroline. To further explore the effect of components positively influencing CFA/I surface expression, a response surface methodology (RSM) was designed incorporating 36 growth conditions. The optimum concentration for each component was identified, thereby generating a novel culture media, SP1, for CFA/I expression. CFs closely related to CFA/I, including CS4 and CS14 were similarly induced in SP1 media. Other epidemiologically relevant CFs were also induced when compared to the level obtained in minimal media. These results indicate that although CF surface expression is complex and highly variable among strains, the CF response can be predicted for closely related strains. A novel culture media inducing CFs in the CF5a group was successfully identified. In addition, mucin was found to positively influence CF expression in strains expressing either CFA/I or CS1 and CS3, and may function as a common environmental cue.

Synthesis and Characterisation of ETS-10/Acetate-based Ionic Liquid/Chitosan Mixed Matrix Membranes for CO2/N2 Permeation

PubMed Central

Casado-Coterillo, Clara; López-Guerrero, María del Mar; Irabien, Ángel

2014-01-01

Mixed matrix membranes (MMMs) were prepared by incorporating organic surfactant-free hydrothermally synthesised ETS-10 and 1-ethyl-3-methylimidazolium acetate ionic liquid (IL) to chitosan (CS) polymer matrix. The membrane material characteristics and permselectivity performance of the two-component membranes were compared with the three-component membrane and the pure CS membrane. The addition of IL increased CO2 solubility of the polymer, and, thus, the CO2 affinity was maintained for the MMMs, which can be correlated with the crystallinity, measured by FT-IR, and void fraction calculations from differences between theoretical and experimental densities. The mechanical resistance was enhanced by the ETS-10 nanoparticles, and flexibility decreased in the two-component ETS-10/CS MMMs, but the flexibility imparted by the IL remained in three-component ETS-10/IL/CS MMMs. The results of this work provide insight into another way of facing the adhesion challenge in MMMs and obtain CO2 selective MMMs from renewable or green chemistry materials. PMID:24957178

Mechanical intermixing of components in (CoMoNi)-based systems and the formation of (CoMoNi)/WC nanocomposite layers on Ti sheets under ball collisions

NASA Astrophysics Data System (ADS)

Romankov, S.; Park, Y. C.; Shchetinin, I. V.

2017-11-01

Cobalt (Co), molybdenum (Mo), and nickel (Ni) components were simultaneously introduced onto titanium (Ti) surfaces from a composed target using ball collisions. Tungsten carbide (WC) balls were selected for processing as the source of a cemented carbide reinforcement phase. During processing, ball collisions continuously introduced components from the target and the grinding media onto the Ti surface and induced mechanical intermixing of the elements, resulting in formation of a complex nanocomposite structure onto the Ti surface. The as-fabricated microstructure consisted of uniformly dispersed WC particles embedded within an integrated metallic matrix composed of an amorphous phase with nanocrystalline grains. The phase composition of the alloyed layers, atomic reactions, and the matrix grain sizes depended on the combination of components introduced onto the Ti surface during milling. The as-fabricated layer exhibited a very high hardness compared to industrial metallic alloys and tool steel materials. This approach could be used for the manufacture of both cemented carbides and amorphous matrix composite layers.

The loss of essential oil components induced by the Purge Time in the Pressurized Liquid Extraction (PLE) procedure of Cupressus sempervirens.

PubMed

Dawidowicz, Andrzej L; Czapczyńska, Natalia B; Wianowska, Dorota

2012-05-30

The influence of different Purge Times on the effectiveness of Pressurized Liquid Extraction (PLE) of volatile oil components from cypress plant matrix (Cupressus sempervirens) was investigated, applying solvents of diverse extraction efficiencies. The obtained results show the decrease of the mass yields of essential oil components as a result of increased Purge Time. The loss of extracted components depends on the extrahent type - the greatest mass yield loss occurred in the case of non-polar solvents, whereas the smallest was found in polar extracts. Comparisons of the PLE method with Sea Sand Disruption Method (SSDM), Matrix Solid-Phase Dispersion Method (MSPD) and Steam Distillation (SD) were performed to assess the method's accuracy. Independent of the solvent and Purge Time applied in the PLE process, the total mass yield was lower than the one obtained for simple, short and relatively cheap low-temperature matrix disruption procedures - MSPD and SSDM. Thus, in the case of volatile oils analysis, the application of these methods is advisable. Copyright © 2012 Elsevier B.V. All rights reserved.

Pixel-level multisensor image fusion based on matrix completion and robust principal component analysis

NASA Astrophysics Data System (ADS)

Wang, Zhuozheng; Deller, J. R.; Fleet, Blair D.

2016-01-01

Acquired digital images are often corrupted by a lack of camera focus, faulty illumination, or missing data. An algorithm is presented for fusion of multiple corrupted images of a scene using the lifting wavelet transform. The method employs adaptive fusion arithmetic based on matrix completion and self-adaptive regional variance estimation. Characteristics of the wavelet coefficients are used to adaptively select fusion rules. Robust principal component analysis is applied to low-frequency image components, and regional variance estimation is applied to high-frequency components. Experiments reveal that the method is effective for multifocus, visible-light, and infrared image fusion. Compared with traditional algorithms, the new algorithm not only increases the amount of preserved information and clarity but also improves robustness.

Effect of the carbonyl iron particles on acoustic absorption properties of magnetic polyurethane foam

NASA Astrophysics Data System (ADS)

Geng, Jialu; Wang, Caiping; Zhu, Honglang; Wang, Xiaojie

2018-03-01

Elastomeric matrix embedded with magnetic micro-sized particles has magnetically controllable properties, which has been investigated extensively in the last decades. In this study we develop a new magnetically controllable elastomeric material for acoustic applications at lower frequencies. The soft polyurethane foam is used as matrix material due to its extraordinary elastic and acoustic absorption properties. One-step method is used to synthesize polyurethane foam, in which all components including polyether polyols 330N, MDI, deionized water, silicone oil, carbonyl iron particle (CIP) and catalyst are put into one container for curing. Changing any component can induce the change of polyurethane foam's properties, such as physical and acoustic properties. The effect of the content of MDI on acoustic absorption is studied. The CIPs are aligned under extra magnetic field during the foaming process. And the property of polyurethane foam with aligned CIPs is also investigated. Scanning electron microscope (SEM) is used to observe the structure of pore and particle-chain. The two-microphone impedance tube and the transfer function method are used to test acoustic absorption property of the magnetic foams.

The Comparison Between Nmf and Ica in Pigment Mixture Identification of Ancient Chinese Paintings

NASA Astrophysics Data System (ADS)

Liu, Y.; Lyu, S.; Hou, M.; Yin, Q.

2018-04-01

Since the colour in painting cultural relics observed by our naked eyes or hyperspectral cameras is usually a mixture of several kinds of pigments, the mixed pigments analysis will be an important subject in the field of ancient painting conservation and restoration. This paper aims to find a more effective method to confirm the types of every pure pigment from mixture on the surface of paintings. Firstly, we adopted two kinds of blind source separation algorithms, which are independent component analysis and non-negative matrix factorization, to extract the pure pigment component from mixed spectrum respectively. Moreover, we matched the separated pure spectrum with the pigments spectra library built by our team to determine the pigment type. Furthermore, three kinds of data including simulation data, mixed pigments spectral data measured in laboratory, and the spectral data of an ancient painting were chosen to evaluate the performance of the different algorithms. And the accuracy was compared between the two algorithms. Finally, the experimental results show that non-negative matrix factorization method is more suitable for endmember extraction in the field of ancient painting conservation and restoration.

Advanced Environmental Barrier Coating Development for SiC-SiC Ceramic Matrix Composite Components

NASA Technical Reports Server (NTRS)

Zhu, Dongming; Harder, Bryan; Hurst, Janet B.; Halbig, Michael Charles; Puleo, Bernadette J.; Costa, Gustavo; Mccue, Terry R.

2017-01-01

This presentation reviews the NASA advanced environmental barrier coating (EBC) system development for SiC-SiC Ceramic Matrix Composite (CMC) combustors particularly under the NASA Environmentally Responsible Aviation, Fundamental Aeronautics and Transformative Aeronautics Concepts Programs. The emphases have been placed on the current design challenges of the 2700-3000F capable environmental barrier coatings for low NOX emission combustors for next generation turbine engines by using advanced plasma spray based processes, and the coating processing and integration with SiC-SiC CMCs and component systems. The developments also have included candidate coating composition system designs, degradation mechanisms, performance evaluation and down-selects; the processing optimizations using TriplexPro Air Plasma Spray Low Pressure Plasma Spray (LPPS), Plasma Spray Physical Vapor Deposition and demonstration of EBC-CMC systems. This presentation also highlights the EBC-CMC system temperature capability and durability improvements under the NASA development programs, as demonstrated in the simulated engine high heat flux, combustion environments, in conjunction with high heat flux, mechanical creep and fatigue loading testing conditions.

Fast radiative transfer models for retrieval of cloud properties in the back-scattering region: application to DSCOVR-EPIC sensor

NASA Astrophysics Data System (ADS)

Molina Garcia, Victor; Sasi, Sruthy; Efremenko, Dmitry; Doicu, Adrian; Loyola, Diego

2017-04-01

In this work, the requirements for the retrieval of cloud properties in the back-scattering region are described, and their application to the measurements taken by the Earth Polychromatic Imaging Camera (EPIC) on board the Deep Space Climate Observatory (DSCOVR) is shown. Various radiative transfer models and their linearizations are implemented, and their advantages and issues are analyzed. As radiative transfer calculations in the back-scattering region are computationally time-consuming, several acceleration techniques are also studied. The radiative transfer models analyzed include the exact Discrete Ordinate method with Matrix Exponential (DOME), the Matrix Operator method with Matrix Exponential (MOME), and the approximate asymptotic and equivalent Lambertian cloud models. To reduce the computational cost of the line-by-line (LBL) calculations, the k-distribution method, the Principal Component Analysis (PCA) and a combination of the k-distribution method plus PCA are used. The linearized radiative transfer models for retrieval of cloud properties include the Linearized Discrete Ordinate method with Matrix Exponential (LDOME), the Linearized Matrix Operator method with Matrix Exponential (LMOME) and the Forward-Adjoint Discrete Ordinate method with Matrix Exponential (FADOME). These models were applied to the EPIC oxygen-A band absorption channel at 764 nm. It is shown that the approximate asymptotic and equivalent Lambertian cloud models give inaccurate results, so an offline processor for the retrieval of cloud properties in the back-scattering region requires the use of exact models such as DOME and MOME, which behave similarly. The combination of the k-distribution method plus PCA presents similar accuracy to the LBL calculations, but it is up to 360 times faster, and the relative errors for the computed radiances are less than 1.5% compared to the results when the exact phase function is used. Finally, the linearized models studied show similar behavior, with relative errors less than 1% for the radiance derivatives, but FADOME is 2 times faster than LDOME and 2.5 times faster than LMOME.

Orchestin, a calcium-binding phosphoprotein, is a matrix component of two successive transitory calcified biomineralizations cyclically elaborated by a terrestrial crustacean.

PubMed

Hecker, Arnaud; Quennedey, Brigitte; Testenière, Olivier; Quennedey, André; Graf, François; Luquet, Gilles

2004-06-01

Orchestia cavimana is a crustacean that cyclically replaces its calcified cuticle during molting cycles in order to grow. Its terrestrial way of life requires storage of calcium during each premolt period, as calcareous concretions, in tubular diverticula of the midgut. During the postmolt period the stored calcium is reabsorbed and is translocated through the storage organ epithelium as calcified small spherules. In a previous study, we sequenced and characterized a remarkable component of the organic matrix of the premolt storage structures, Orchestin, which is a calcium-binding phosphoprotein. In this paper, we analyzed the spatiotemporal expression of the orchestin gene by Northern blotting and in situ hybridization, and its translated product by immunocytochemistry. We found evidence that the gene and the protein are expressed specifically during premolt in the storage organs. More interestingly, we demonstrated that the protein is synthesized also during the postmolt period, as a component of the organic matrix of the calcium resorption spherules. Thus, Orchestin is a matrix component that is synthesized by the same cells to contribute alternately to the elaboration of two different calcifications. These results, in addition to the physical and chemical features of the protein, suggest that Orchestin is probably a key molecule in the calcium carbonate precipitation process leading to the cyclic elaboration of two transitory calcified mineralizations by the crustacean Orchestia.

HIGH DIMENSIONAL COVARIANCE MATRIX ESTIMATION IN APPROXIMATE FACTOR MODELS

PubMed Central

Fan, Jianqing; Liao, Yuan; Mincheva, Martina

2012-01-01

The variance covariance matrix plays a central role in the inferential theories of high dimensional factor models in finance and economics. Popular regularization methods of directly exploiting sparsity are not directly applicable to many financial problems. Classical methods of estimating the covariance matrices are based on the strict factor models, assuming independent idiosyncratic components. This assumption, however, is restrictive in practical applications. By assuming sparse error covariance matrix, we allow the presence of the cross-sectional correlation even after taking out common factors, and it enables us to combine the merits of both methods. We estimate the sparse covariance using the adaptive thresholding technique as in Cai and Liu (2011), taking into account the fact that direct observations of the idiosyncratic components are unavailable. The impact of high dimensionality on the covariance matrix estimation based on the factor structure is then studied. PMID:22661790

Characterization of DOM adsorption of CNTs by using excitation-emission matrix fluorescence spectroscopy and multiway analysis.

PubMed

Peng, Mingguo; Li, Huajie; Li, Dongdong; Du, Erdeng; Li, Zhihong

2017-06-01

Carbon nanotubes (CNTs) were utilized to adsorb DOM in micro-polluted water. The characteristics of DOM adsorption on CNTs were investigated based on UV 254 , TOC, and fluorescence spectrum measurements. Based on PARAFAC (parallel factor) analysis, four fluorescent components were extracted, including one protein-like component (C4) and three humic acid-like components (C1, C2, and C3). The adsorption isotherms, kinetics, and thermodynamics of DOM adsorption on CNTs were further investigated. A Freundlich isotherm model fit the adsorption data well with high values of correlation. As a type of macro-porous and meso-porous adsorbent, CNTs preferably adsorb humic acid-like substances rather than protein-like substances. The increasing temperature will speed up the adsorption process. The self-organizing map (SOM) analysis further explains the fluorescent properties of water samples. The results provide a new insight into the adsorption behaviour of DOM fluorescent components on CNTs.

Perturbative approach to covariance matrix of the matter power spectrum

DOE PAGES

Mohammed, Irshad; Seljak, Uros; Vlah, Zvonimir

2016-12-14

Here, we evaluate the covariance matrix of the matter power spectrum using perturbation theory up to dominant terms at 1-loop order and compare it to numerical simulations. We decompose the covariance matrix into the disconnected (Gaussian) part, trispectrum from the modes outside the survey (beat coupling or super-sample variance), and trispectrum from the modes inside the survey, and show how the different components contribute to the overall covariance matrix. We find the agreement with the simulations is at a 10\\% level up tomore » $$k \\sim 1 h {\\rm Mpc^{-1}}$$. We also show that all the connected components are dominated by the large-scale modes ($$k<0.1 h {\\rm Mpc^{-1}}$$), regardless of the value of the wavevectors $$k,\\, k'$$ of the covariance matrix, suggesting that one must be careful in applying the jackknife or bootstrap methods to the covariance matrix. We perform an eigenmode decomposition of the connected part of the covariance matrix, showing that at higher $k$ it is dominated by a single eigenmode. Furthermore, the full covariance matrix can be approximated as the disconnected part only, with the connected part being treated as an external nuisance parameter with a known scale dependence, and a known prior on its variance for a given survey volume. Finally, we provide a prescription for how to evaluate the covariance matrix from small box simulations without the need to simulate large volumes.« less

Collagen type I as a ligand for receptor-mediated signaling

NASA Astrophysics Data System (ADS)

Boraschi-Diaz, Iris; Wang, Jennifer; Mort, John S.; Komarova, Svetlana V.

2017-05-01

Collagens form the fibrous component of the extracellular matrix in all multi-cellular animals. Collagen type I is the most abundant collagen present in skin, tendons, vasculature, as well as the organic portion of the calcified tissue of bone and teeth. This review focuses on numerous receptors for which collagen acts as a ligand, including integrins, discoidin domain receptors DDR1 and 2, OSCAR, GPVI, G6b-B and Lair-1 of the leukocyte receptor complex and mannose family receptor uPARAP/Endo 180. We explore the process of collagen production and self-assembly, as well as its degradation by collagenases and gelatinases in order to predict potential temporal and spatial sites of action of different collagen receptors. While the interactions of the mature collagen matrix with integrins and DDR are well-appreciated, potential signals from immature matrix as well as collagen degradation products are possible but not yet described. The role of multiple collagen receptors in physiological processes and their contribution to pathophysiology of diseases affecting collagen homeostasis require further studies.

Inhibition of Neutrophil Collagenase/MMP-8 and Gelatinase B/MMP-9 and Protection against Endotoxin Shock

PubMed Central

Qiu, Zheng; Chen, Jianghai; Xu, Hanmei; Van den Steen, Philippe E.; Opdenakker, Ghislain; Wang, Min

2014-01-01

Endotoxin shock is a life-threatening disorder, associated with the rapid release of neutrophil enzymes, including neutrophil collagenase/matrix metalloproteinase-8 (MMP-8) and gelatinase B/matrix metalloproteinase-9 (MMP-9). After activation, these enzymes cleave extracellular matrix components and cytokines and thus may contribute to shock syndrome development. MMP inhibitors have been suggested as immunotherapy of endotoxin shock. However, little is known about the therapeutic time window of MMP inhibition. Here, a sublethal endotoxin shock mouse model was used to evaluate the effect of an MMP inhibiting peptide (P2) after intravenous or intraperitoneal injection and to study the time window between LPS and inhibitor injections. With the use of a specific ELISA the plasma P2 concentrations were monitored. Whereas we corroborated the treatment strategy of MMP targeting in endotoxin shock with a new inhibitor, we also demonstrated that the time window, within which effective MMP inhibition increased the survival rates, is rather limited. PMID:25762310

Orthorhombic Titanium Matrix Composite Subjected to Simulated Engine Mission Cycles

NASA Technical Reports Server (NTRS)

Gabb, Timothy P.

1997-01-01

Titanium matrix composites (TMC's) are commonly made up of a titanium alloy matrix reinforced by silicon carbide fibers that are oriented parallel to the loading axis. These composites can provide high strength at lower densities than monolithic titanium alloys and superalloys in selected gas turbine engine applications. The use of TMC rings with unidirectional SiC fibers as reinforcing rings within compressor rotors could significantly reduce the weight of these components. In service, these TMC reinforcing rings would be subjected to complex service mission loading cycles, including fatigue and dwell excursions. Orthorhombic titanium aluminide alloys are of particular interest for such TMC applications because their tensile and creep strengths are high in comparison to those of other titanium alloys. The objective of this investigation was to assess, in simulated mission tests at the NASA Lewis Research Center, the durability of a SiC (SCS-6)/Ti-22Al-23Nb (at.%) TMC for compressor ring applications, in cooperation with the Allison Engine Company.

Plastic substrates for active matrix liquid crystal display incapable of withstanding processing temperature of over 200 C and method of fabrication

DOEpatents

Carey, P.G.; Smith, P.M.; Havens, J.H.; Jones, P.

1999-01-05

Bright-polarizer-free, active-matrix liquid crystal displays (AMLCDs) are formed on plastic substrates. The primary components of the display are a pixel circuit fabricated on one plastic substrate, an intervening liquid-crystal material, and a counter electrode on a second plastic substrate. The-pixel circuit contains one or more thin-film transistors (TFTs) and either a transparent or reflective pixel electrode manufactured at sufficiently low temperatures to avoid damage to the plastic substrate. Fabrication of the TFTs can be carried out at temperatures less than 100 C. The liquid crystal material is a commercially made nematic curvilinear aligned phase (NCAP) film. The counter electrode is comprised of a plastic substrate coated with a transparent conductor, such as indium-doped tin oxide (ITO). By coupling the active matrix with NCAP, a high-information content can be provided in a bright, fully plastic package. Applications include any low cost portable electronics containing flat displays where ruggedization of the display is desired. 12 figs.

Plastic substrates for active matrix liquid crystal display incapable of withstanding processing temperature of over 200.degree. C and method of fabrication

DOEpatents

Carey, Paul G.; Smith, Patrick M.; Havens, John; Jones, Phil

1999-01-01

Bright-polarizer-free, active-matrix liquid crystal displays (AMLCDs) are formed on plastic substrates. The primary components of the display are a pixel circuit fabricated on one plastic substrate, an intervening liquid-crystal material, and a counter electrode on a second plastic substrate. The-pixel circuit contains one or more thin-film transistors (TFTs) and either a transparent or reflective pixel electrode manufactured at sufficiently low temperatures to avoid damage to the plastic substrate. Fabrication of the TFTs can be carried out at temperatures less than 100.degree. C. The liquid crystal material is a commercially made nematic curvilinear aligned phase (NCAP) film. The counter electrode is comprised of a plastic substrate coated with a transparent conductor, such as indium-doped tin oxide (ITO). By coupling the active matrix with NCAP, a high-information content can be provided in a bright, fully plastic package. Applications include any low cost portable electronics containing flat displays where ruggedization of the display is desired.

Substrate-protecting antiproteolytic agents for the prevention of pathological degradation of connective tissues. A review.

PubMed

Robert, A-M

2012-02-01

Connective tissues play an important role in the physiological functions of the organism. The integrity of the macromolecular components of these tissues, also called extracellular matrix, is necessary for their functional efficiency. A number of proteinases present in the organism, and the activity of which increases with age and with several pathologies, specifically degrade the components of the extracellular matrix. For a long time, tentatives for the protection of the matrix-components against degradation were made with low molecular weight inhibitors, not very efficient in vivo and not devoid of inconveniencies. We initiated a different approach for the preservation of the macromolecules of the extracellular matrix against proteolytic degradation with substances which exert an intense antiproteolytic activity not only in vitro, but also in vivo. The particularity of these substances is the fact that they do not act on the enzymes, but combine with the macromolecules. This is the type of combination of substances with the macromolecules of the matrix that prevents their degradation by the proteinases. Because of this affinity of such antiproteolytic agents not for the enzymes but for the substrates, we called them "substrate protectors" (Robert et al., 1979). The aim of the present review is to summarise the essential of our experiments which led to the description of substrate protectors. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

Molybdenum disilicide alloy matrix composite

DOEpatents

Petrovic, John J.; Honnell, Richard E.; Gibbs, W. Scott

1990-01-01

Compositions of matter consisting of matrix matrials having silicon carbide dispersed throughout them and methods of making the compositions. A matrix material is an alloy of an intermetallic compound, molybdenum disilicide, and at least one secondary component which is a refractory silicide. The silicon carbide dispersant may be in the form of VLS whiskers, VS whiskers, or submicron powder or a mixture of these forms.

Molybdenum disilicide alloy matrix composite

DOEpatents

Petrovic, John J.; Honnell, Richard E.; Gibbs, W. Scott

1991-01-01

Compositions of matter consisting of matrix materials having silicon carbide dispersed throughout them and methods of making the compositions. A matrix material is an alloy of an intermetallic compound, molybdenum disilicide, and at least one secondary component which is a refractory silicide. The silicon carbide dispersant may be in the form of VLS whiskers, VS whiskers, or submicron powder or a mixture of these forms.

Experimental Detection and Visualization of the Extracellular Matrix in Macrocolony Biofilms.

PubMed

Serra, Diego O; Hengge, Regine

2017-01-01

By adopting elaborate three-dimensional morphologies that vary according to their extracellular matrix composition, macrocolony biofilms offer a unique opportunity to interrogate about the roles of specific matrix components in shaping biofilm architecture. Here, we describe two methods optimized for Escherichia coli that profit from morphology and the high level of structural organization of macrocolonies to gain insight into the production and assembly of amyloid curli and cellulose-the two major biofilm matrix elements of E. coli-in biofilms. The first method, the macrocolony morphology assay, is based on the ability of curli and cellulose-either alone or in combination-to generate specific morphological and Congo Red-staining patterns in E. coli macrocolonies, which can then be used as a direct visual readout for the production of these matrix components. The second method involves thin sectioning of macrocolonies, which along with in situ staining of amyloid curli and cellulose and microscopic imaging allows gaining fine details of the spatial arrangement of both matrix elements inside macrocolonies. Beyond their current use with E. coli and related curli and cellulose-producing Enterobacteriaceae, both the methods offer the potential to be adapted to other bacterial species.

Fibrinogen inhibits fibroblast-mediated contraction of collagen

PubMed Central

Nien, Yih-Dar; Han, Yuan-Ping; Tawil, Bill; Chan, Linda S.; Tuan, Tai-Lan; Garner, Warren L.

2008-01-01

Extracellular matrix changes in composition and organization as it transitions from the provisional matrix of the fibrin/platelet plug to collagen scar in healed wounds. The manner in which individual matrix proteins affect these activities is not well established. In this article we describe the interactions of two important extracellular matrix components, fibrin and collagen, using an in vitro model of wound contraction, the fibroblast-populated collagen lattice. We utilized different fibrinogen sources and measured tissue reorganization in floating and tensioned collagen lattices. Our results showed that both fibrin and fibrinogen decreased the contraction of fibroblast populated collagen lattices in a dose-dependent manner. Polymerization of fibrinogen to fibrin using thrombin had no effect on this inhibition. Further, there was no effect due to changes in protein concentration, alternate components of the fibrin sealant, or the enzymatic action of thrombin. These results suggest that the initial stability of the fibrin provisional matrix is due to the fibrin, because this protein appears to inhibit contraction of the matrix. This may be important in the early phases of wound healing when clot stability is vital for hemostasis. Later, as fibrin is replaced by collagen, wound contraction can occur. PMID:12950643

Interactions between Skeletal Muscle Myoblasts and their Extracellular Matrix Revealed by a Serum Free Culture System.

PubMed

Chaturvedi, Vishal; Dye, Danielle E; Kinnear, Beverley F; van Kuppevelt, Toin H; Grounds, Miranda D; Coombe, Deirdre R

2015-01-01

Decellularisation of skeletal muscle provides a system to study the interactions of myoblasts with muscle extracellular matrix (ECM). This study describes the efficient decellularisation of quadriceps muscle with the retention of matrix components and the use of this matrix for myoblast proliferation and differentiation under serum free culture conditions. Three decellularisation approaches were examined; the most effective was phospholipase A2 treatment, which removed cellular material while maximizing the retention of ECM components. Decellularised muscle matrices were then solubilized and used as substrates for C2C12 mouse myoblast serum free cultures. The muscle matrix supported myoblast proliferation and differentiation equally as well as collagen and fibronectin. Immunofluorescence analyses revealed that myoblasts seeded on muscle matrix and fibronectin differentiated to form long, well-aligned myotubes, while myoblasts seeded on collagen were less organized. qPCR analyses showed a time dependent increase in genes involved in skeletal muscle differentiation and suggested that muscle-derived matrix may stimulate an increased rate of differentiation compared to collagen and fibronectin. Decellularized whole muscle three-dimensional scaffolds also supported cell adhesion and spreading, with myoblasts aligning along specific tracts of matrix proteins within the scaffolds. Thus, under serum free conditions, intact acellular muscle matrices provided cues to direct myoblast adhesion and migration. In addition, myoblasts were shown to rapidly secrete and organise their own matrix glycoproteins to create a localized ECM microenvironment. This serum free culture system has revealed that the correct muscle ECM facilitates more rapid cell organisation and differentiation than single matrix glycoprotein substrates.

Microstructures, Mechanical Properties, and Wear Resistances of Thixoextruded SiCp/WE43 Magnesium Matrix Composites

NASA Astrophysics Data System (ADS)

Chen, Qiang; Chen, Gang; Han, Fei; Xia, Xiangsheng; Wu, Yang

2017-07-01

Near-net shaping of Mg-RE alloy matrix composites has received increasing attention. In this work, stir casting followed by extrusion was adopted to fabricate Mg-RE alloy (WE43) matrix composites reinforced by micron-sized SiC particles. The microstructural evolutions of SiCp/WE43 composites partially remelted from as-cast and extruded states were studied. Furthermore, the thixoformability of SiCp/WE43 composites in different states was evaluated by thixoextruding a type of double-cup component. The microstructures of as-cast SiCp/WE43 composites were optimized under the comprehensive effects of SiC particles and RE elements. The SiCp/WE43 composite was fully recrystallized during hot extrusion, and the α-Mg matrix consisted of fine equiaxed grains. Although the as-cast SiCp/WE43 composite consisted of satisfactory structures and can be successfully thixoextruded into the final component with good surface quality and no evidence of internal defects, the microstructures, Vickers hardness, tensile mechanical properties, and wear resistance were still inferior to those of the component thixoextruded from extruded composite. Moreover, the thixoextrusion process was analyzed schematically, and an ideal thixoforming process that should contain two stages was proposed.

A component prediction method for flue gas of natural gas combustion based on nonlinear partial least squares method.

PubMed

Cao, Hui; Yan, Xingyu; Li, Yaojiang; Wang, Yanxia; Zhou, Yan; Yang, Sanchun

2014-01-01

Quantitative analysis for the flue gas of natural gas-fired generator is significant for energy conservation and emission reduction. The traditional partial least squares method may not deal with the nonlinear problems effectively. In the paper, a nonlinear partial least squares method with extended input based on radial basis function neural network (RBFNN) is used for components prediction of flue gas. For the proposed method, the original independent input matrix is the input of RBFNN and the outputs of hidden layer nodes of RBFNN are the extension term of the original independent input matrix. Then, the partial least squares regression is performed on the extended input matrix and the output matrix to establish the components prediction model of flue gas. A near-infrared spectral dataset of flue gas of natural gas combustion is used for estimating the effectiveness of the proposed method compared with PLS. The experiments results show that the root-mean-square errors of prediction values of the proposed method for methane, carbon monoxide, and carbon dioxide are, respectively, reduced by 4.74%, 21.76%, and 5.32% compared to those of PLS. Hence, the proposed method has higher predictive capabilities and better robustness.

Collagen in the spicule organic matrix of the gorgonian Leptogorgia virgulata

NASA Technical Reports Server (NTRS)

Kingsley, R. J.; Tsuzaki, M.; Watabe, N.; Mechanic, G. L.

1990-01-01

Decalcification of the calcareous spicules from the gorgonian Leptogorgia virgulata reveals an organic matrix that may be divided into water insoluble and soluble fractions. The insoluble fraction displays characteristics typical of collagen, which is an unusual component of an invertebrate calcium carbonate structure. This matrix fraction exhibits a collagenous amino acid profile and behavior upon SDS-PAGE. Furthermore, the reducible crosslink, dihydroxylysinonorleucine (DHLNL), is detected in this fraction. The composition of the matrix varies seasonally; i.e., the collagenous composition is most prevalent in the summer. These results indicate that the insoluble matrix is a dynamic structure. Potential roles of this matrix in spicule calcification are discussed.

A novel color image encryption scheme using alternate chaotic mapping structure

NASA Astrophysics Data System (ADS)

Wang, Xingyuan; Zhao, Yuanyuan; Zhang, Huili; Guo, Kang

2016-07-01

This paper proposes an color image encryption algorithm using alternate chaotic mapping structure. Initially, we use the R, G and B components to form a matrix. Then one-dimension logistic and two-dimension logistic mapping is used to generate a chaotic matrix, then iterate two chaotic mappings alternately to permute the matrix. For every iteration, XOR operation is adopted to encrypt plain-image matrix, then make further transformation to diffuse the matrix. At last, the encrypted color image is obtained from the confused matrix. Theoretical analysis and experimental results has proved the cryptosystem is secure and practical, and it is suitable for encrypting color images.

Quasi-periodic solutions to the hierarchy of four-component Toda lattices

NASA Astrophysics Data System (ADS)

Wei, Jiao; Geng, Xianguo; Zeng, Xin

2016-08-01

Starting from a discrete 3×3 matrix spectral problem, the hierarchy of four-component Toda lattices is derived by using the stationary discrete zero-curvature equation. Resorting to the characteristic polynomial of the Lax matrix for the hierarchy, we introduce a trigonal curve Km-2 of genus m - 2 and present the related Baker-Akhiezer function and meromorphic function on it. Asymptotic expansions for the Baker-Akhiezer function and meromorphic function are given near three infinite points on the trigonal curve, from which explicit quasi-periodic solutions for the hierarchy of four-component Toda lattices are obtained in terms of the Riemann theta function.

Advanced Environmental Barrier Coating Development for SiC-SiC Ceramic Matrix Composite Components

NASA Technical Reports Server (NTRS)

Zhu, Dongming; Harder, Bryan; Bhatt, Ramakrishna; Kiser, Doug; Wiesner, Valerie L.

2016-01-01

This presentation reviews the NASA advanced environmental barrier coating (EBC) system development for SiCSiC Ceramic Matrix Composite (CMC) components for next generation turbine engines. The emphasis has been placed on the current design challenges of the 2700F environmental barrier coatings; coating processing and integration with SiCSiC CMCs and component systems; and performance evaluation and demonstration of EBC-CMC systems. This presentation also highlights the EBC-CMC system temperature capability and durability improvements through advanced compositions and architecture designs, as shown in recent simulated engine high heat flux, combustion environment, in conjunction with mechanical creep and fatigue loading testing conditions.

A comparison of likelihood ratio tests and Rao's score test for three separable covariance matrix structures.

PubMed

Filipiak, Katarzyna; Klein, Daniel; Roy, Anuradha

2017-01-01

The problem of testing the separability of a covariance matrix against an unstructured variance-covariance matrix is studied in the context of multivariate repeated measures data using Rao's score test (RST). The RST statistic is developed with the first component of the separable structure as a first-order autoregressive (AR(1)) correlation matrix or an unstructured (UN) covariance matrix under the assumption of multivariate normality. It is shown that the distribution of the RST statistic under the null hypothesis of any separability does not depend on the true values of the mean or the unstructured components of the separable structure. A significant advantage of the RST is that it can be performed for small samples, even smaller than the dimension of the data, where the likelihood ratio test (LRT) cannot be used, and it outperforms the standard LRT in a number of contexts. Monte Carlo simulations are then used to study the comparative behavior of the null distribution of the RST statistic, as well as that of the LRT statistic, in terms of sample size considerations, and for the estimation of the empirical percentiles. Our findings are compared with existing results where the first component of the separable structure is a compound symmetry (CS) correlation matrix. It is also shown by simulations that the empirical null distribution of the RST statistic converges faster than the empirical null distribution of the LRT statistic to the limiting χ 2 distribution. The tests are implemented on a real dataset from medical studies. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Anti-oxidative and photo-protective effects of coumarins isolated from Fraxinus chinensis.

PubMed

Lee, Bum-Chun; Lee, So Yong; Lee, Hwa Jeong; Sim, Gwan-Sub; Kim, Jin-Hui; Kim, Jin-Hwa; Cho, Young-Ho; Lee, Dong-Hwan; Pyo, Hyeong-Bae; Choe, Tae-Boo; Moon, Dong Cheul; Yun, Yeo Pyo; Hong, Jin Tae

2007-10-01

Free radicals and reactive oxygen species (ROS), which are generated by UV irradiation, may cause serious injury to skin cell membranes, DNA and functional proteins. In addition, these agents stimulate the expressions of matrix metalloproteinases (MMPs), which can degrade most components of the extracellular matrix (ECM), including collagen. In order to develop new anti-photoaging agents, five major components from the extract of Fraxinus chinensis extract (FCE) were identified. Two of the major components of FCE were found to be esculin (11.2%) and esculetin (1.9%). FCE (IC50: 50.0 microg/mL 1, 1-diphenyl-2-picrylhydrazyl (DPPH); 19.8 microg/mL, superoxide anion radical) and esculetin (IC50: 2.1 microg/mL DPPH; 0.6 microg/mL, superoxide anion radical) showed strong antioxidative activities. Of the compounds tested, esculetin showed the strongest scavenging activity against DPPH radicals, followed by superoxide anions from the xanthine/xanthine oxidase system. The intracellular ROS scavenging activity showed that oxidation of 5-(6-)-chloromethyl-2', 7'-dichlorodihydrofluorescein diacetate (CM-H2DCFDA) was effectively inhibited by esculetin, with potent free radical scavenging activity was also shown in UVB-irradiated human dermal fibroblasts (HDFs). Moreover, treatment of UVA-irradiated HDFs with esculetin resulted in dose-dependent decreases in the expression levels of MMP-1 mRNA and protein. From these results, FCE and one of its components, esculetin, were predicted to be potentially useful as ingredients in cosmetics for protecting against photoaging.

Extracellular Matrix and the Mechanics of Large Artery Development

PubMed Central

Cheng, Jeffrey K.; Wagenseil, Jessica E.

2012-01-01

The large, elastic arteries, as their name suggests, provide elastic distention and recoil during the cardiac cycle in vertebrate animals. The arteries are distended from the pressure of ejecting blood during active contraction of the left ventricle (LV) during systole, and recoil to their original dimensions during relaxation of the LV during diastole. The cyclic distension occurs with minimal energy loss, due to the elastic properties of one of the major structural extracellular matrix (ECM) components, elastin. The maximum distension is limited to prevent damage to the artery by another major ECM component, collagen. The mix of ECM components in the wall largely determines the passive mechanical behavior of the arteries and the subsequent load on the heart during systole. While much research has focused on initial artery formation, there has been less attention on the continuing development of the artery to produce the mature composite wall complete with endothelial cells (ECs), smooth muscle cells (SMCs), and the necessary mix of ECM components for proper cardiovascular function. This review focuses on the physiology of large artery development, including SMC differentiation and ECM production. The effects of hemodynamic forces and ECM deposition on the evolving arterial structure and function are discussed. Human diseases and mouse models with genetic mutations in ECM proteins that affect large artery development are summarized. A review of constitutive models and growth and remodeling theories is presented, along with future directions to improve understanding of ECM and the mechanics of large artery development. PMID:22584609

Web-based tailored intervention for preparation of parents and children for outpatient surgery (WebTIPS): development.

PubMed

Kain, Zeev N; Fortier, Michelle A; Chorney, Jill MacLaren; Mayes, Linda

2015-04-01

As a result of cost-containment efforts, preparation programs for outpatient surgery are currently not available to the majority of children and parents. The recent dramatic growth in the Internet presents a unique opportunity to transform how children and their parents are prepared for surgery. In this article, we describe the development of a Web-based Tailored Intervention for Preparation of parents and children undergoing Surgery (WebTIPS). A multidisciplinary taskforce agreed that a Web-based tailored intervention consisting of intake, matrix, and output modules was the preferred approach. Next, the content of the various intake variables, the matrix logic, and the output content was developed. The output product has a parent component and a child component and is described in http://surgerywebtips.com/about.php. The child component makes use of preparation strategies such as information provision, modeling, play, and coping skills training. The parent component of WebTIPS includes strategies such as information provision, coping skills training, and relaxation and distraction techniques. A reputable animation and Web design company developed a secured Web-based product based on the above description. In this article, we describe the development of a Web-based tailored preoperative preparation program that can be accessed by children and parents multiple times before and after surgery. A follow-up article in this issue of Anesthesia & Analgesia describes formative evaluation and preliminary efficacy testing of this Web-based tailored preoperative preparation program.

Web-based Tailored Intervention for Preparation of Parents and Children for Outpatient Surgery (WebTIPS): Development

PubMed Central

Kain, Zeev N.; Fortier, Michelle A.; Chorney, Jill MacLaren; Mayes, Linda

2014-01-01

Background Due to cost-containment efforts, preparation programs for outpatient surgery are currently not available to the majority of children and parents. The recent dramatic growth in the Internet presents a unique opportunity to transform how children and their parents are prepared for surgery. In this article we describe the development of a Web-based tailored preparation program for children and parents undergoing surgery (WebTIPS). Development of Program A multidisciplinary taskforce agreed that a Web-based tailored intervention comprised of intake, matrix and output modules was the preferred approach. Next, the content of the various intake variables, the matrix logic and the output content was developed. The output product has a parent component and a child component and is described in http://surgerywebtips.com/about.php. The child component makes use of preparation strategies such as information provision, modeling, play and coping skills training. The parent component of WebTIPS includes strategies such as information provision, coping skills training, relaxation and distraction techniques. A reputable animation and Web-design company developed a secured Web-based product based on the above description. Conclusions In this article we describe the development of a Web-based tailored preoperative preparation program that can be accessed by children and parents multiple times before and after surgery. A follow-up article in this issue of Anesthesia & Analgesia describes formative evaluation and preliminary efficacy testing of this Web-based tailored preoperative preparation program. PMID:25790212

Multivariate Analysis of Mixed Lipid Aggregate Phase Transitions Monitored Using Raman Spectroscopy.

PubMed

Neal, Sharon L

2018-01-01

The phase behavior of aqueous 1,2-dimyristoyl-sn-glycero-3-phosphorylcholine (DMPC)/1,2-dihexanoyl-sn-glycero-3-phosphocholine (DHPC) mixtures between 8.0 ℃ and 41.0 ℃ were monitored using Raman spectroscopy. Temperature-dependent Raman matrices were assembled from series of spectra and subjected to multivariate analysis. The consensus of pseudo-rank estimation results is that seven to eight components account for the temperature-dependent changes observed in the spectra. The spectra and temperature response profiles of the mixture components were resolved by applying a variant of the non-negative matrix factorization (NMF) algorithm described by Lee and Seung (1999). The rotational ambiguity of the data matrix was reduced by augmenting the original temperature-dependent spectral matrix with its cumulative counterpart, i.e., the matrix formed by successive integration of the spectra across the temperature index (columns). Successive rounds of constrained NMF were used to isolate component spectra from a significant fluorescence background. Five major components exhibiting varying degrees of gel and liquid crystalline lipid character were resolved. Hydrogen-bonded water networks exhibiting varying degrees of organization are associated with the lipid components. Spectral parameters were computed to compare the chain conformation, packing, and hydration indicated by the resolved spectra. Based on spectral features and relative amounts of the components observed, four components reflect long chain lipid response. The fifth component could reflect the response of the short chain lipid, DHPC, but there were no definitive spectral features confirming this assignment. A minor component of uncertain assignment that exhibits a striking response to the DMPC pre-transition and chain melting transition also was recovered. While none of the spectra resolved exhibit features unequivocally attributable to a specific aggregate morphology or step in the gelation process, the results are consistent with the evolution of mixed phase bicelles (nanodisks) and small amounts of worm-like DMPC/DHPC aggregates, and perhaps DHPC micelles, at low temperature to suspensions of branched and entangled worm-like aggregates above the DMPC gel phase transition and perforated multi-lamellar aggregates at high temperature.

The symmetries of the system matrix and propagator matrix for anisotropic media and of the system matrix forperiodically layered media

NASA Astrophysics Data System (ADS)

Xu, Guo-Ming; Ni, Si-Dao

1998-11-01

The `auxiliary' symmetry properties of the system matrix (symmetry with respect to the trailing diagonal) for a general anisotropic dissipative medium and the special form for a monoclinic medium are revealed by rearranging the motion-stress vector. The propagator matrix of a single-layer general anisotropic dissipative medium is also shown to have auxiliary symmetry. For the multilayered case, a relatively simple matrix method is utilized to obtain the inverse of the propagator matrix. Further, Woodhouse's inverse of the propagator matrix for a transversely isotropic medium is extended in a clearer form to handle the monoclinic symmetric medium. The properties of a periodic layer system are studied through its system matrix Aly , which is computed from the propagator matrix P. The matrix Aly is then compared with Aeq , the system matrix for the long-wavelength equivalent medium of the periodic isotropic layers. Then we can find how the periodic layered medium departs from its long-wavelength equivalent medium when the wavelength decreases. In our numerical example, the results show that, when λ/D decreases to 6-8, the components of the two matrices will depart from each other. The component ratio of these two matrices increases to its maximum (more than 15 in our numerical test) when λ/D is reduced to 2.3, and then oscillates with λ/D when it is further reduced. The eigenvalues of the system matrix Aly show that the velocities of P and S waves decrease when λ/D is reduced from 6-8 and reach their minimum values when λ/D is reduced to 2.3 and then oscillate afterwards. We compute the time shifts between the peaks of the transmitted waves and the incident waves. The resulting velocity curves show a similar variation to those computed from the eigenvalues of the system matrix Aly , but on a smaller scale. This can be explained by the spectrum width of the incident waves.

Molecularly Imprinted Sol-Gel-Based QCM Sensor Arrays for the Detection and Recognition of Volatile Aldehydes.

PubMed

Liu, Chuanjun; Wyszynski, Bartosz; Yatabe, Rui; Hayashi, Kenshi; Toko, Kiyoshi

2017-02-16

The detection and recognition of metabolically derived aldehydes, which have been identified as important products of oxidative stress and biomarkers of cancers; are considered as an effective approach for early cancer detection as well as health status monitoring. Quartz crystal microbalance (QCM) sensor arrays based on molecularly imprinted sol-gel (MISG) materials were developed in this work for highly sensitive detection and highly selective recognition of typical aldehyde vapors including hexanal (HAL); nonanal (NAL) and bezaldehyde (BAL). The MISGs were prepared by a sol-gel procedure using two matrix precursors: tetraethyl orthosilicate (TEOS) and tetrabutoxytitanium (TBOT). Aminopropyltriethoxysilane (APT); diethylaminopropyltrimethoxysilane (EAP) and trimethoxy-phenylsilane (TMP) were added as functional monomers to adjust the imprinting effect of the matrix. Hexanoic acid (HA); nonanoic acid (NA) and benzoic acid (BA) were used as psuedotemplates in view of their analogous structure to the target molecules as well as the strong hydrogen-bonding interaction with the matrix. Totally 13 types of MISGs with different components were prepared and coated on QCM electrodes by spin coating. Their sensing characters towards the three aldehyde vapors with different concentrations were investigated qualitatively. The results demonstrated that the response of individual sensors to each target strongly depended on the matrix precursors; functional monomers and template molecules. An optimization of the 13 MISG materials was carried out based on statistical analysis such as principle component analysis (PCA); multivariate analysis of covariance (MANCOVA) and hierarchical cluster analysis (HCA). The optimized sensor array consisting of five channels showed a high discrimination ability on the aldehyde vapors; which was confirmed by quantitative comparison with a randomly selected array. It was suggested that both the molecularly imprinting (MIP) effect and the matrix effect contributed to the sensitivity and selectivity of the optimized sensor array. The developed MISGs were expected to be promising materials for the detection and recognition of volatile aldehydes contained in exhaled breath or human body odor.

Molecularly Imprinted Sol-Gel-Based QCM Sensor Arrays for the Detection and Recognition of Volatile Aldehydes

PubMed Central

Liu, Chuanjun; Wyszynski, Bartosz; Yatabe, Rui; Hayashi, Kenshi; Toko, Kiyoshi

2017-01-01

The detection and recognition of metabolically derived aldehydes, which have been identified as important products of oxidative stress and biomarkers of cancers; are considered as an effective approach for early cancer detection as well as health status monitoring. Quartz crystal microbalance (QCM) sensor arrays based on molecularly imprinted sol-gel (MISG) materials were developed in this work for highly sensitive detection and highly selective recognition of typical aldehyde vapors including hexanal (HAL); nonanal (NAL) and bezaldehyde (BAL). The MISGs were prepared by a sol-gel procedure using two matrix precursors: tetraethyl orthosilicate (TEOS) and tetrabutoxytitanium (TBOT). Aminopropyltriethoxysilane (APT); diethylaminopropyltrimethoxysilane (EAP) and trimethoxy-phenylsilane (TMP) were added as functional monomers to adjust the imprinting effect of the matrix. Hexanoic acid (HA); nonanoic acid (NA) and benzoic acid (BA) were used as psuedotemplates in view of their analogous structure to the target molecules as well as the strong hydrogen-bonding interaction with the matrix. Totally 13 types of MISGs with different components were prepared and coated on QCM electrodes by spin coating. Their sensing characters towards the three aldehyde vapors with different concentrations were investigated qualitatively. The results demonstrated that the response of individual sensors to each target strongly depended on the matrix precursors; functional monomers and template molecules. An optimization of the 13 MISG materials was carried out based on statistical analysis such as principle component analysis (PCA); multivariate analysis of covariance (MANCOVA) and hierarchical cluster analysis (HCA). The optimized sensor array consisting of five channels showed a high discrimination ability on the aldehyde vapors; which was confirmed by quantitative comparison with a randomly selected array. It was suggested that both the molecularly imprinting (MIP) effect and the matrix effect contributed to the sensitivity and selectivity of the optimized sensor array. The developed MISGs were expected to be promising materials for the detection and recognition of volatile aldehydes contained in exhaled breath or human body odor. PMID:28212347

Experimental and Computational Study of Interphase Properties and Mechanics in Titanium Metal Matrix Composites at Elevated Temperatures

DTIC Science & Technology

2005-03-01

size of the interphase [22-24]. Yang and Jeng [45], in a study of the titanium aluminides Ti-24-11 and Ti-25-10, and a metastable beta titanium Ti-15-3... Titanium Aluminide Matrix Composites," Workshop proceedings on Titanium Matrix Components, P.R. Smith and W.C. Revelos, eds., Wright-Patterson AFB...Experimental and Computational Study of Interphase Properties and Mechanics in Titanium Metal Matrix Composites at Elevated Temperatures Final Report

Characterization of extracellular polymeric substances in biofilms under long-term exposure to ciprofloxacin antibiotic using fluorescence excitation-emission matrix and parallel factor analysis.

PubMed

Gu, Chaochao; Gao, Pin; Yang, Fan; An, Dongxuan; Munir, Mariya; Jia, Hanzhong; Xue, Gang; Ma, Chunyan

2017-05-01

The presence of antibiotic residues in the environment has been regarded as an emerging concern due to their potential adverse environmental consequences such as antibiotic resistance. However, the interaction between antibiotics and extracellular polymeric substances (EPSs) of biofilms in wastewater treatment systems is not entirely clear. In this study, the effect of ciprofloxacin (CIP) antibiotic on biofilm EPS matrix was investigated and characterized using fluorescence excitation-emission matrix (EEM) and parallel factor (PARAFAC) analysis. Physicochemical analysis showed that the proteins were the major EPS fraction, and their contents increased gradually with an increase in CIP concentration (0-300 μg/L). Based on the characterization of biofilm tightly bound EPS (TB-EPS) by EEM, three fluorescent components were identified by PARAFAC analysis. Component C1 was associated with protein-like substances, and components C2 and C3 belonged to humic-like substances. Component C1 exhibited an increasing trend as the CIP addition increased. Pearson's correlation results showed that CIP correlated significantly with the protein contents and component C1, while strong correlations were also found among UV 254 , dissolved organic carbon, humic acids, and component C3. A combined use of EEM-PARAFAC analysis and chemical measurements was demonstrated as a favorable approach for the characterization of variations in biofilm EPS in the presence of CIP antibiotic.

A new pre-loaded beam geometric stiffness matrix with full rigid body capabilities

NASA Astrophysics Data System (ADS)

Bosela, P. A.; Fertis, D. G.; Shaker, F. J.

1992-09-01

Space structures, such as the Space Station solar arrays, must be extremely light-weight, flexible structures. Accurate prediction of the natural frequencies and mode shapes is essential for determining the structural adequacy of components, and designing a controls system. The tension pre-load in the 'blanket' of photovoltaic solar collectors, and the free/free boundary conditions of a structure in space, causes serious reservations on the use of standard finite element techniques of solution. In particular, a phenomenon known as 'grounding', or false stiffening, of the stiffness matrix occurs during rigid body rotation. The authors have previously shown that the grounding phenomenon is caused by a lack of rigid body rotational capability, and is typical in beam geometric stiffness matrices formulated by others, including those which contain higher order effects. The cause of the problem was identified as the force imbalance inherent in the formulations. In this paper, the authors develop a beam geometric stiffness matrix for a directed force problem, and show that the resultant global stiffness matrix contains complete rigid body mode capabilities, and performs very well in the diagonalization methodology customarily used in dynamic analysis.

The pearl oyster Pinctada fucata martensii genome and multi-omic analyses provide insights into biomineralization

PubMed Central

Fan, Guangyi; Jiao, Yu; Zhang, He; Huang, Ronglian; Zheng, Zhe; Bian, Chao; Deng, Yuewen; Wang, Qingheng; Wang, Zhongduo; Liang, Xinming; Liang, Haiying; Shi, Chengcheng; Zhao, Xiaoxia; Sun, Fengming; Hao, Ruijuan; Bai, Jie; Liu, Jialiang; Chen, Wenbin; Liang, Jinlian; Liu, Weiqing; Xu, Zhe; Shi, Qiong; Xu, Xun

2017-01-01

Abstract Nacre, the iridescent material found in pearls and shells of molluscs, is formed through an extraordinary process of matrix-assisted biomineralization. Despite recent advances, many aspects of the biomineralization process and its evolutionary origin remain unknown. The pearl oyster Pinctada fucata martensii is a well-known master of biomineralization, but the molecular mechanisms that underlie its production of shells and pearls are not fully understood. We sequenced the highly polymorphic genome of the pearl oyster and conducted multi-omic and biochemical studies to probe nacre formation. We identified a large set of novel proteins participating in matrix-framework formation, many in expanded families, including components similar to that found in vertebrate bones such as collagen-related VWA-containing proteins, chondroitin sulfotransferases, and regulatory elements. Considering that there are only collagen-based matrices in vertebrate bones and chitin-based matrices in most invertebrate skeletons, the presence of both chitin and elements of collagen-based matrices in nacre suggests that elements of chitin- and collagen-based matrices have deep roots and might be part of an ancient biomineralizing matrix. Our results expand the current shell matrix-framework model and provide new insights into the evolution of diverse biomineralization systems. PMID:28873964

Deterministic control of broadband light through a multiply scattering medium via the multispectral transmission matrix

PubMed Central

Andreoli, Daria; Volpe, Giorgio; Popoff, Sébastien; Katz, Ori; Grésillon, Samuel; Gigan, Sylvain

2015-01-01

We present a method to measure the spectrally-resolved transmission matrix of a multiply scattering medium, thus allowing for the deterministic spatiospectral control of a broadband light source by means of wavefront shaping. As a demonstration, we show how the medium can be used to selectively focus one or many spectral components of a femtosecond pulse, and how it can be turned into a controllable dispersive optical element to spatially separate different spectral components to arbitrary positions. PMID:25965944

The development of control and monitoring system on marine current renewable energy Case study: strait of Toyapakeh - Nusa Penida, Bali

NASA Astrophysics Data System (ADS)

Arief, I. S.; Suherman, I. H.; Wardani, A. Y.; Baidowi, A.

2017-05-01

Control and monitoring system is a continuous process of securing the asset in the Marine Current Renewable Energy. A control and monitoring system is existed each critical components which is embedded in Failure Mode Effect Analysis (FMEA) method. As the result, the process in this paper developed through a matrix sensor. The matrix correlated to critical components and monitoring system which supported by sensors to conduct decision-making.

The Extracellular Matrix in Photosynthetic Mats: A Cyanobacterial Gingerbread House

NASA Astrophysics Data System (ADS)

Stuart, R.; Stannard, W.; Bebout, B.; Pett-Ridge, J.; Mayali, X.; Weber, P. K.; Lipton, M. S.; Lee, J.; Everroad, R. C.; Thelen, M.

2014-12-01

Hypersaline laminated cyanobacterial mats are excellent model systems for investigating photoautotrophic contributions to biogeochemical cycling on a millimeter scale. These self-sustaining ecosystems are characterized by steep physiochemical gradients that fluctuate dramatically on hour timescales, providing a dynamic environment to study microbial response. However, elucidating the distribution of energy from light absorption into biomass requires a complete understanding of the various constituents of the mat. Extracellular polymeric substances (EPS), which can be composed of proteins, polysaccharides, lipids and DNA are a major component of these mats and may function in the redistribution of nutrients and metabolites within the community. To test this notion, we established a model mat-building culture for comparison with the phylogenetically diverse natural mat communities. In these two systems we determined how proteins and glycans in the matrix changed as a function of light and tracked nutrient flow from the matrix. Using mass spectrometry metaproteomics analysis, we found homologous proteins in both field and culture extracellular matrix that point to cyanobacterial turnover of amino acids, inorganic nutrients, carbohydrates and nucleic acids from the EPS. Other abundant functions identified included oxidative stress response from both the cyanobacteria and heterotrophs and cyanobacterial structural proteins that may play a role in mat cohesion. Several degradative enzymes also varied in abundance in the EPS in response to light availability, suggesting active secretion. To further test cyanobacterial EPS turnover, we generated isotopically-labeled EPS and used NanoSIMS to trace uptake of this labeled EPS. Our findings suggest Cyanobacteria may facilitate nutrient transfer to other groups, as well as uptake of their own products through degradation of EPS components. This work provides evidence for the essential roles of EPS for storage, structural cohesion and protection, with active light-dependent turnover by both Cyanobacteria and the heterotrophic community.

Implementation and Assessment of Advanced Analog Vector-Matrix Processor

NASA Technical Reports Server (NTRS)

Gary, Charles K.; Bualat, Maria G.; Lum, Henry, Jr. (Technical Monitor)

1994-01-01

This paper discusses the design and implementation of an analog optical vecto-rmatrix coprocessor with a throughput of 128 Mops for a personal computer. Vector matrix calculations are inherently parallel, providing a promising domain for the use of optical calculators. However, to date, digital optical systems have proven too cumbersome to replace electronics, and analog processors have not demonstrated sufficient accuracy in large scale systems. The goal of the work described in this paper is to demonstrate a viable optical coprocessor for linear operations. The analog optical processor presented has been integrated with a personal computer to provide full functionality and is the first demonstration of an optical linear algebra processor with a throughput greater than 100 Mops. The optical vector matrix processor consists of a laser diode source, an acoustooptical modulator array to input the vector information, a liquid crystal spatial light modulator to input the matrix information, an avalanche photodiode array to read out the result vector of the vector matrix multiplication, as well as transport optics and the electronics necessary to drive the optical modulators and interface to the computer. The intent of this research is to provide a low cost, highly energy efficient coprocessor for linear operations. Measurements of the analog accuracy of the processor performing 128 Mops are presented along with an assessment of the implications for future systems. A range of noise sources, including cross-talk, source amplitude fluctuations, shot noise at the detector, and non-linearities of the optoelectronic components are measured and compared to determine the most significant source of error. The possibilities for reducing these sources of error are discussed. Also, the total error is compared with that expected from a statistical analysis of the individual components and their relation to the vector-matrix operation. The sufficiency of the measured accuracy of the processor is compared with that required for a range of typical problems. Calculations resolving alloy concentrations from spectral plume data of rocket engines are implemented on the optical processor, demonstrating its sufficiency for this problem. We also show how this technology can be easily extended to a 100 x 100 10 MHz (200 Cops) processor.

Gene Expression Profiling of the Intact Dermal Sheath Cup of Human Hair Follicles.

PubMed

Niiyama, Shiro; Ishimatsu-Tsuji, Yumiko; Nakazawa, Yosuke; Yoshida, Yuzo; Soma, Tsutomu; Ideta, Ritsuro; Mukai, Hideki; Kishimoto, Jiro

2018-04-24

Cells that constitute the dermal papillae of hair follicles might be derived from the dermal sheath, the peribulbar component of which is the dermal sheath cup. The dermal sheath cup is thought to include the progenitor cells of the dermal papillae and possesses hair inductive potential; however, it has not yet been well characterized. This study investigated the gene expression profile of the intact dermal sheath cup, and identified dermal sheath cup signature genes, including extracellular matrix components and BMP-binding molecules, as well as TGF-b1 as an upstream regulator. Among these, GREM2, a member of the BMP antagonists, was found by in situ hybridization to be highly specific to the dermal sheath cup, implying that GREM2 is a key molecule contributing to maintenance of the properties of the dermal sheath cup.

Random matrix theory and fund of funds portfolio optimisation

NASA Astrophysics Data System (ADS)

Conlon, T.; Ruskin, H. J.; Crane, M.

2007-08-01

The proprietary nature of Hedge Fund investing means that it is common practise for managers to release minimal information about their returns. The construction of a fund of hedge funds portfolio requires a correlation matrix which often has to be estimated using a relatively small sample of monthly returns data which induces noise. In this paper, random matrix theory (RMT) is applied to a cross-correlation matrix C, constructed using hedge fund returns data. The analysis reveals a number of eigenvalues that deviate from the spectrum suggested by RMT. The components of the deviating eigenvectors are found to correspond to distinct groups of strategies that are applied by hedge fund managers. The inverse participation ratio is used to quantify the number of components that participate in each eigenvector. Finally, the correlation matrix is cleaned by separating the noisy part from the non-noisy part of C. This technique is found to greatly reduce the difference between the predicted and realised risk of a portfolio, leading to an improved risk profile for a fund of hedge funds.

Altered Liver Proteoglycan/Glycosaminoglycan Structure as a Manifestation of Extracellular Matrix Remodeling upon BCG-induced Granulomatosis in Mice.

PubMed

Kim, L B; Shkurupy, V A; Putyatina, A N

2017-01-01

Experimental BCG-induced granulomatosis in mice was used to study changes in the dynamics of individual liver proteoglycan components reflecting phasic extracellular matrix remodeling, determined by the host-parasite interaction and associated with granuloma development. In the early BCG-granulomatosis period, the increase in individual proteoglycan components promotes granuloma formation, providing conditions for mycobacteria adhesion to host cells, migration of phagocytic cells from circulation, and cell-cell interaction leading to granuloma development and fibrosis. Later, reduced reserve capacity of the extracellular matrix, development of interstitial fibrosis and granuloma fibrosis can lead to trophic shortage for cells within the granulomas, migration of macrophages out of them, and development of spontaneous necrosis and apoptosis typical of tuberculosis.

Characterization of Cell Surface and EPS Remodeling of Azospirillum brasilense Chemotaxis-like 1 Signal Transduction Pathway mutants by Atomic Force Microscopy

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

Billings, Amanda N; Siuti, Piro; Bible, Amber

2011-01-01

To compete in complex microbial communities, bacteria must quickly sense environmental changes and adjust cellular functions for optimal growth. Chemotaxis-like signal transduction pathways are implicated in the modulation of multiple cellular responses, including motility, EPS production, and cell-to-cell interactions. Recently, the Che1 chemotaxis-like pathway from Azospirillum brasilense was shown to modulate flocculation. In A. brasilense, cell surface properties, including EPS production, are thought to play a direct role in promoting flocculation. Using atomic force microscopy (AFM), we have detected distinct changes in the surface morphology of flocculating A. brasilense Che1 mutant strains that are absent in the wild type strain.more » Whereas the wild type strain produces a smooth mucosal extracellular matrix, the flocculating Che1 mutant strains produce distinctive extracellular fibril structures. Further analyses using flocculation inhibition and lectin-binding assays suggest that the composition of EPS components in the extracellular matrix differs between the cheA1 and cheY1 mutants, despite an apparent similarity in the macroscopic floc structures. Collectively, these data indicate that mutations in the Che1 pathway that result in increased flocculation are correlated with distinctive changes in the extracellular matrix structure produced by the mutants, including likely changes in the EPS structure and/or composition.« less

Oxidation modifies the structure and function of the extracellular matrix generated by human coronary artery endothelial cells.

PubMed

Chuang, Christine Y; Degendorfer, Georg; Hammer, Astrid; Whitelock, John M; Malle, Ernst; Davies, Michael J

2014-04-15

ECM (extracellular matrix) materials, such as laminin, perlecan, type IV collagen and fibronectin, play a key role in determining the structure of the arterial wall and the properties of cells that interact with the ECM. The aim of the present study was to investigate the effect of peroxynitrous acid, an oxidant generated by activated macrophages, on the structure and function of the ECM laid down by HCAECs (human coronary artery endothelial cells) in vitro and in vivo. We show that exposure of HCAEC-derived native matrix components to peroxynitrous acid (but not decomposed oxidant) at concentrations >1 μM results in a loss of antibody recognition of perlecan, collagen IV, and cell-binding sites on laminin and fibronectin. Loss of recognition was accompanied by decreased HCAEC adhesion. Real-time PCR showed up-regulation of inflammation-associated genes, including MMP7 (matrix metalloproteinase 7) and MMP13, as well as down-regulation of the laminin α2 chain, in HCAECs cultured on peroxynitrous acid-treated matrix compared with native matrix. Immunohistochemical studies provided evidence of co-localization of laminin with 3-nitrotyrosine, a biomarker of peroxynitrous acid damage, in type II-III/IV human atherosclerotic lesions, consistent with matrix damage occurring during disease development in vivo. The results of the present study suggest a mechanism through which peroxynitrous acid modifies endothelial cell-derived native ECM proteins of the arterial basement membrane in atherosclerotic lesions. These changes to ECM and particularly perlecan and laminin may be important in inducing cellular dysfunction and contribute to atherogenesis.

Fourier decomposition of payoff matrix for symmetric three-strategy games.

PubMed

Szabó, György; Bodó, Kinga S; Allen, Benjamin; Nowak, Martin A

2014-10-01

In spatial evolutionary games the payoff matrices are used to describe pair interactions among neighboring players located on a lattice. Now we introduce a way how the payoff matrices can be built up as a sum of payoff components reflecting basic symmetries. For the two-strategy games this decomposition reproduces interactions characteristic to the Ising model. For the three-strategy symmetric games the Fourier components can be classified into four types representing games with self-dependent and cross-dependent payoffs, variants of three-strategy coordinations, and the rock-scissors-paper (RSP) game. In the absence of the RSP component the game is a potential game. The resultant potential matrix has been evaluated. The general features of these systems are analyzed when the game is expressed by the linear combinations of these components.

Molybdenum disilicide alloy matrix composite

DOEpatents

Petrovic, J.J.; Honnell, R.E.; Gibbs, W.S.

1991-12-03

Compositions of matter consisting of matrix materials having silicon carbide dispersed throughout them and methods of making the compositions are disclosed. A matrix material is an alloy of an intermetallic compound, molybdenum disilicide, and at least one secondary component which is a refractory silicide. The silicon carbide dispersant may be in the form of VLS whiskers, VS whiskers, or submicron powder or a mixture of these forms. 3 figures.

Integrity of Narrow Epithelial Tubes in the C. elegans Excretory System Requires a Transient Luminal Matrix

PubMed Central

Ayala-Figueroa, Jesus; Parry, Jean M.; Pu, Pu; Hall, David H.

2016-01-01

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 this matrix component in supporting lumen integrity within narrow bore tubes such as those found in the mammalian microvasculature, and reveal functional importance of the evolutionarily conserved ZP domain in this tube protecting activity. PMID:27482894

The role of serum hyaluronic acid determination in the diagnosis of liver fibrosis.

PubMed

Gudowska, Monika; Cylwik, Bogdan; Chrostek, Lech

2017-01-01

The common pathway leading to liver fibrosis and cirrhosis is growing deposition of extracellular matrix (ECM). It results from molecular and histological rearrangement of collagens, glycoproteins and hyaluronans. Hyaluronic acid is a chief component of the extracellular matrix of connective tissues and plays the main structural role in the formation of ECM. The most important organ involved in the synthesis of hyaluronic acid is the liver. In this paper the meaning of hyaluronic acid in the diagnostics of liver diseases is discussed. Here, we focus on the described changes of hyaluronic acid concentration in the pathological processes of the liver, including alcoholic and non-alcoholic liver diseases. The results of published clinical studies have shown its high diagnostic sensitivity, which probably enables its application in laboratory diagnosis.

Nuclear Magnetic Resonance Used to Quantify the Effect of Pyrolysis Conditions on the Oxidative Stability of Silicon Oxycarbide Ceramics

NASA Technical Reports Server (NTRS)

1996-01-01

This work was undertaken in support of the Low Cost Ceramic Composite Virtual Company, (LC^3), whose members include Northrop Grumman Corporation, AlliedSignal Inc., and Allison Advanced Development Company. LC^3 is a cost-shared effort funded by the Advanced Research Projects Agency (ARPA) and the LC^3 participants to develop a low-cost fabrication methodology for manufacturing ceramic matrix composite structural components. The program, which is being administered by the U.S. Air Force Wright Laboratory Materials Directorate, is focused on demonstrating a ceramic matrix composite turbine seal for a regional aircraft engine. This part is to be fabricated by resin transfer molding of a siloxane polymer into a fiber preform that will be transformed into a ceramic by pyrolytic conversion.

Fabrication and Testing of Ceramic Matrix Composite Rocket Propulsion Components

NASA Technical Reports Server (NTRS)

Effinger, M. R.; Clinton, R. C., Jr.; Dennis, J.; Elam, S.; Genge, G.; Eckel, A.; Jaskowiak, M. H.; Kiser, J. D.; Lang, J.

2001-01-01

NASA has established goals for Second and Third Generation Reusable Launch Vehicles. Emphasis has been placed on significantly improving safety and decreasing the cost of transporting payloads to orbit. Ceramic matrix composites (CMC) components are being developed by NASA to enable significant increases in safety and engineer performance, while reducing costs. The development of the following CMC components are being pursued by NASA: (1) Simplex CMC Blisk; (2) Cooled CMC Nozzle Ramps; (3) Cooled CMC Thrust Chambers; and (4) CMC Gas Generator. These development efforts are application oriented, but have a strong underpinning of fundamental understanding of processing-microstructure-property relationships relative to structural analyses, nondestructive characterization, and material behavior analysis at the coupon and component and system operation levels. As each effort matures, emphasis will be placed on optimizing and demonstrating material/component durability, ideally using a combined Building Block Approach and Build and Bust Approach.

Therapeutic Strategies for Modulating the Extracellular Matrix to Improve Pancreatic Islet Function and Survival After Transplantation.

PubMed

Smink, Alexandra M; de Vos, Paul

2018-05-19

Extracellular matrix (ECM) components modulate the interaction between pancreatic islet cells. During the islet isolation prior to transplantation as treatment for type 1 diabetes, the ECM is disrupted impacting functional graft survival. Recently, strategies for restoring ECM have shown to improve transplantation outcomes. This review discusses the current therapeutic strategies to modulate ECM components to improve islet engraftment. Approaches applied are seeding islets in ECM of decellularized organs, supplementation of specific ECM components in polymeric scaffolds or immunoisolating capsules, and stimulating islet ECM production with specific growth factors or ECM-producing cells. These strategies have shown success in improving functional islet survival. However, the same experiments show that caution should be taken as some ECM components may negatively impact islet function and engraftment. ECM restoration resulted in improved transplantation outcomes, but careful selection of beneficial ECM components and strategies is warranted.

The Effects of Extracellular Matrix Proteins on Neutrophil-Endothelial Interaction ― A Roadway To Multiple Therapeutic Opportunities

PubMed Central

Padmanabhan, Jagannath; Gonzalez, Anjelica L.

2012-01-01

Polymorphoneuclear leukocytes or neutrophils, a major component of white blood cells, contribute to the innate immune response in humans. Upon sensing changes in the microenvironment, neutrophils adhere to the vascular wall, migrate through the endothelial cell (EC)-pericyte bilayer, and subsequently through the extracellular matrix to reach the site of inflammation. These cells are capable of destroying microbes, cell debris, and foreign proteins by oxidative and non-oxidative processes. While primarily mediators of tissue homeostasis, there are an increasing number of studies indicating that neutrophil recruitment and transmigration can also lead to host-tissue injury and subsequently inflammation-related diseases. Neutrophil-induced tissue injury is highly regulated by the microenvironment of the infiltrated tissue, which includes cytokines, chemokines, and the provisional extracellular matrix, remodeled through increased vascular permeability and other cellular infiltrates. Thus, investigation of the effects of matrix proteins on neutrophil-EC interaction and neutrophil transmigration may help identify the proteins that induce pro- or anti-inflammatory responses. This area of research presents an opportunity to identify therapeutic targets in inflammation-related diseases. This review will summarize recent literature on the role of neutrophils and the effects of matrix proteins on neutrophil-EC interactions, with focus on three different disease models: 1) atherosclerosis, 2) COPD, and 3) tumor growth and progression. For each disease model, inflammatory molecules released by neutrophils, important regulatory matrix proteins, current anti-inflammatory treatments, and the scope for further research will be summarized. PMID:22737047

Maribo—A new CM fall from Denmark

NASA Astrophysics Data System (ADS)

Haack, Henning; Grau, Thomas; Bischoff, Addi; Horstmann, Marian; Wasson, John; Sørensen, Anton; Laubenstein, Matthias; Ott, Ulrich; Palme, Herbert; Gellissen, Marko; Greenwood, Richard C.; Pearson, Victoria K.; Franchi, Ian A.; Gabelica, Zelimir; Schmitt-Kopplin, Philippe

2012-01-01

Maribo is a new Danish CM chondrite, which fell on January 17, 2009, at 19:08:28 CET. The fall was observed by many eye witnesses and recorded by a surveillance camera, an all sky camera, a few seismic stations, and by meteor radar observatories in Germany. A single fragment of Maribo with a dry weight of 25.8 g was found on March 4, 2009. The coarse-grained components in Maribo include chondrules, fine-grained olivine aggregates, large isolated lithic clasts, metals, and mineral fragments (often olivine), and rare Ca,Al-rich inclusions. The components are typically rimmed by fine-grained dust mantles. The matrix includes abundant dust rimmed fragments of tochilinite with a layered, fishbone-like texture, tochilinite-cronstedtite intergrowths, sulfides, metals, and carbonates often intergrown with tochilinite. The oxygen isotopic composition: (δ17O = -1.27‰; δ18O = 4.96‰; Δ17O = -3.85‰) plots at the edge of the CM field, close to the CCAM line. The very low Δ17O and the presence of unaltered components suggest that Maribo is among the least altered CM chondrites. The bulk chemistry of Maribo is typical of CM chondrites. Trapped noble gases are similar in abundance and isotopic composition to other CM chondrites, stepwise heating data indicating the presence of gas components hosted by presolar diamond and silicon carbide. The organics in Maribo include components also seen in Murchison as well as nitrogen-rich components unique to Maribo.

Basement Membrane Defects in Genetic Kidney Diseases

PubMed Central

Chew, Christine; Lennon, Rachel

2018-01-01

The glomerular basement membrane (GBM) is a specialized structure with a significant role in maintaining the glomerular filtration barrier. This GBM is formed from the fusion of two basement membranes during development and its function in the filtration barrier is achieved by key extracellular matrix components including type IV collagen, laminins, nidogens, and heparan sulfate proteoglycans. The characteristics of specific matrix isoforms such as laminin-521 (α5β2γ1) and the α3α4α5 chain of type IV collagen are essential for the formation of a mature GBM and the restricted tissue distribution of these isoforms makes the GBM a unique structure. Detailed investigation of the GBM has been driven by the identification of inherited abnormalities in matrix proteins and the need to understand pathogenic mechanisms causing severe glomerular disease. A well-described hereditary GBM disease is Alport syndrome, associated with a progressive glomerular disease, hearing loss, and lens defects due to mutations in the genes COL4A3, COL4A4, or COL4A5. Other proteins associated with inherited diseases of the GBM include laminin β2 in Pierson syndrome and LMX1B in nail patella syndrome. The knowledge of these genetic mutations associated with GBM defects has enhanced our understanding of cell–matrix signaling pathways affected in glomerular disease. This review will address current knowledge of GBM-associated abnormalities and related signaling pathways, as well as discussing the advances toward disease-targeted therapies for patients with glomerular disease. PMID:29435440

Spindle pole body component 25 homolog expressed by ECM stiffening is required for lung cancer cell proliferation.

PubMed

Jeong, Jangho; Keum, Seula; Kim, Daehwan; You, Eunae; Ko, Panseon; Lee, Jieun; Kim, Jaegu; Kim, Jung-Woong; Rhee, Sangmyung

2018-06-12

Accumulating evidence has shown that matrix stiffening in cancer tissue by the deposition of extracellular matrix (ECM) is closely related with severe tumor progression. However, much less is known about the genes affected by matrix stiffness and its signaling for cancer progression. In the current research, we investigated the differential gene expression of a non-small lung adenocarcinoma cell line, H1299, cultured under the conditions of soft (∼0.5 kPa) and stiff (∼40 kPa) matrices, mimicking the mechanical environments of normal and cancerous tissues, respectively. For integrated transcriptome analysis, the genes identified by ECM stiffening were compared with 8248 genes retrieved from The Cancer Genome Atlas Lung Adenocarcinoma (TCGA). In stiff matrix, 29 genes were significantly upregulated, while 75 genes were downregulated. The screening of hazard ratios for these genes using the Kaplan-Meier Plotter identified 8 genes most closely associated with cancer progression under the condition of matrix stiffening. Among these genes, spindle pole body component 25 homolog (SPC25) was one of the most up-regulated genes in stiff matrix and tumor tissue. Knockdown of SPC25 in H1299 cells using shRNA significantly inhibited cell proliferation with downregulation of the expression of checkpoint protein, Cyclin B1, under the condition of stiff matrix whereas the proliferation rate in soft matrix was not affected by SPC25 silencing. Thus, our findings provide novel key molecules for studying the relationship of extracellular matrix stiffening and cancer progression. Copyright © 2018 Elsevier Inc. All rights reserved.

The provisional matrix: setting the stage for tissue repair outcomes.

PubMed

Barker, Thomas H; Engler, Adam J

2017-07-01

Since its conceptualization in the 1980s, the provisional matrix has often been characterized as a simple fibrin-containing scaffold for wound healing that supports the nascent blood clot and is functionally distinct from the basement membrane. However subsequent advances have shown that this matrix is far from passive, with distinct compositional differences as the wound matures, and providing an active role for wound remodeling. Here we review the stages of this matrix, provide an update on the state of our understanding of provisional matrix, and present some of the outstanding issues related to the provisional matrix, its components, and their assembly and use in vivo. Copyright © 2017. Published by Elsevier B.V.

Molecular Diagnosis in Autoimmune Skin Blistering Conditions

PubMed Central

Otten, J.V.; Hashimoto, T.; Hertl, M.; Payne, A.S.; Sitaru, C.

2014-01-01

Blister formation in skin and mucous membranes results from a loss of cell-cell or cell-matrix adhesion and is a common outcome of pathological events in a variety of conditions, including autoimmune and genetic diseases, viral and bacterial infections, or injury by physical and chemical factors. Autoantibodies against structural components maintaining cell-cell and cell-matrix adhesion induce tissue damage in autoimmune blistering diseases. Detection of these autoantibodies either tissue-bound or circulating in serum is essential to diagnose the autoimmune nature of disease. Various immunofluorescence methods as well as molecular immunoassays, including enzyme-linked immunosorbent assay and immunoblotting, belong to the modern diagnostic algorithms for these disorders. There is still a considerable need to increase awareness of the rare autoimmune blistering diseases, which often show a severe, chronic-relapsing course, among physicians and the public. This review article describes the immunopathological features of autoimmune bullous diseases and the molecular immunoassays currently available for their diagnosis and monitoring. PMID:24160488

Structural reliability analysis of laminated CMC components

NASA Technical Reports Server (NTRS)

Duffy, Stephen F.; Palko, Joseph L.; Gyekenyesi, John P.

1991-01-01

For laminated ceramic matrix composite (CMC) materials to realize their full potential in aerospace applications, design methods and protocols are a necessity. The time independent failure response of these materials is focussed on and a reliability analysis is presented associated with the initiation of matrix cracking. A public domain computer algorithm is highlighted that was coupled with the laminate analysis of a finite element code and which serves as a design aid to analyze structural components made from laminated CMC materials. Issues relevant to the effect of the size of the component are discussed, and a parameter estimation procedure is presented. The estimation procedure allows three parameters to be calculated from a failure population that has an underlying Weibull distribution.

An optimized protocol for handling and processing fragile acini cultured with the hanging drop technique.

PubMed

Snyman, Celia; Elliott, Edith

2011-12-15

The hanging drop three-dimensional culture technique allows cultivation of functional three-dimensional mammary constructs without exogenous extracellular matrix. The fragile acini are, however, difficult to preserve during processing steps for advanced microscopic investigation. We describe adaptations to the protocol for handling of hanging drop cultures to include investigation using confocal, scanning, and electron microscopy, with minimal loss of cell culture components. Copyright © 2011 Elsevier Inc. All rights reserved.

Three dimensional empirical mode decomposition analysis apparatus, method and article manufacture

NASA Technical Reports Server (NTRS)

Gloersen, Per (Inventor)

2004-01-01

An apparatus and method of analysis for three-dimensional (3D) physical phenomena. The physical phenomena may include any varying 3D phenomena such as time varying polar ice flows. A repesentation of the 3D phenomena is passed through a Hilbert transform to convert the data into complex form. A spatial variable is separated from the complex representation by producing a time based covariance matrix. The temporal parts of the principal components are produced by applying Singular Value Decomposition (SVD). Based on the rapidity with which the eigenvalues decay, the first 3-10 complex principal components (CPC) are selected for Empirical Mode Decomposition into intrinsic modes. The intrinsic modes produced are filtered in order to reconstruct the spatial part of the CPC. Finally, a filtered time series may be reconstructed from the first 3-10 filtered complex principal components.

Dissection of the Human Multipotent Adult Progenitor Cell Secretome by Proteomic Analysis

PubMed Central

van't Hof, Wouter; Newell, Laura F.; Reddy, Ashok; Wilmarth, Phillip A.; David, Larry L.; Raber, Amy; Bogaerts, Annelies; Pinxteren, Jef; Deans, Robert J.; Maziarz, Richard T.

2013-01-01

Multipotent adult progenitor cells (MAPCs) are adult adherent stromal stem cells currently being assessed in acute graft versus host disease clinical trials with demonstrated immunomodulatory capabilities and the potential to ameliorate detrimental autoimmune and inflammation-related processes. Our previous studies documented that MAPCs secrete factors that play a role in regulating T-cell activity. Here we expand our studies using a proteomics approach to characterize and quantify MAPC secretome components secreted over 72 hours in vitro under steady-state conditions and in the presence of the inflammatory triggers interferon-γ and lipopolysaccharide, or a tolerogenic CD74 ligand, RTL1000. MAPCs differentially responded to each of the tested stimuli, secreting molecules that regulate the biological activity of the extracellular matrix (ECM), including proteins that make up the ECM itself, proteins that regulate its construction/deconstruction, and proteins that serve to attach and detach growth factors from ECM components for redistribution upon appropriate stimulation. MAPCs secreted a wide array of proteases, some detectable in their zymogen forms. MAPCs also secreted protease inhibitors that would regulate protease activity. MAPCs secreted chemokines and cytokines that could provide molecular guidance cues to various cell types, including neutrophils, macrophages, and T cells. In addition, MAPCs secreted factors involved in maintenance of a homeostatic environment, regulating such diverse programs as innate immunity, angiogenesis/angiostasis, targeted delivery of growth factors, and the matrix-metalloprotease cascade. PMID:23981727

Handheld SFDI/polarimetric imaging device for objective evaluation of hypertrophic scars (Conference Presentation)

NASA Astrophysics Data System (ADS)

Ramella-Roman, Jessica C.; Montejo, Karla; Sevilla, Nicole; Stoff, Susan; Gonzalez, Mariacarla; Chue-Sang, Joseph

2017-02-01

Scars can be debilitating and cause serious functional limitations, significantly reduced physical function and loss of ability to perform normal daily activities. Scar formation is not fully understood and the treatment options have been hampered by the lack of an objective diagnostic tool to assess scars. Presently, assessment of hypertrophic scars has been based on subjective clinician rankings using a four-parameter scale called the Vancouver Scar Scale (VSS) or the Patient Observer Scar Assessment Scale (POSAS) but no objective, standardized tool for quantifying scar severity is available, despite known inadequacies of the subjective scales. We have developed a hand-held multi modal system consisting of a combined Spatial Frequency Domain Imager (SFDI) used for the assessment of tissue molecular components and a polarimeter for structural measurements. The SFDI capability is provided by an Arduino board controlled spectrally and polarimetric diverse Light Emitting Diodes (LED) ring illuminator. For SFDI imagery, the LEDs are combined with sinusoidal patterns. A single pattern snapshot SFDI approach is used to observe and quantify the biological components in the scar tissue including: oxygenated and de oxygenated hemoglobin, water, and melanin. The SFDI system is integrated with a reduced Mueller Matrix polarimetric system, whose illumination is also included in the LED's ring, and providing for the assessment of collagen orientation through Mueller Matrix decomposition. The design of the system and experimental work on phantoms will be presented.

Evidence for the Activation of Shallow Preferential Flow Paths in a Tropical Panama Watershed Using Germanium and Silicon

NASA Astrophysics Data System (ADS)

Gardner, Christopher B.; Litt, Guy F.; Lyons, W. Berry; Ogden, Fred L.

2017-10-01

In humid tropical watersheds, the hydrologic flow paths taken by rain event waters and how they interact with groundwater and soil matrix water to form streamflow are poorly understood. Preferential flow paths (PFPs) confound storm infiltration processes, especially in the humid tropics where PFPs are common. This work applies germanium (Ge) and silicon (Si) as natural flow path tracers in conjunction with water stable isotopes and electrical conductivity to examine the rapid delivery of shallow soil water, the activation of PFPs, and event water partitioning in an experimental catchment in central Panama. We employed a three-component mixing model for hydrograph separation using the following end-member waters: (i) base flow (high [Si], low [Ge], and low Ge/Si ratio), (ii) dilute canopy throughfall (low [Si] and low [Ge]), and (iii) shallow (<15 cm) soil matrix water (low [Si], high [Ge], and high Ge/Si ratio). These three end-members bounded all observed Ge/Si streamflow ratios. During small rain events (<˜24 mm), base flow and dilute canopy throughfall components dominated stormflow. During larger precipitation events (>˜35 mm), we detected the third shallow soil water component with an elevated [Ge] and Ge/Si ratio. This component reached its maximum during the hydrograph's receding limb coincident with the maximum event fraction, and increased proportionally to the total storm rainfall exceeding ˜35 mm. Only shallow (<15 cm) soil matrix water exhibited elevated Ge concentrations and high Ge/Si ratios. This third component represents rapidly delivered soil matrix water combined with shallow lateral PFP activation through which event waters interact with soil minerals.

Correlation, Cost Risk, and Geometry

NASA Technical Reports Server (NTRS)

Dean, Edwin B.

1992-01-01

The geometric viewpoint identifies the choice of a correlation matrix for the simulation of cost risk with the pairwise choice of data vectors corresponding to the parameters used to obtain cost risk. The correlation coefficient is the cosine of the angle between the data vectors after translation to an origin at the mean and normalization for magnitude. Thus correlation is equivalent to expressing the data in terms of a non orthogonal basis. To understand the many resulting phenomena requires the use of the tensor concept of raising the index to transform the measured and observed covariant components into contravariant components before vector addition can be applied. The geometric viewpoint also demonstrates that correlation and covariance are geometric properties, as opposed to purely statistical properties, of the variates. Thus, variates from different distributions may be correlated, as desired, after selection from independent distributions. By determining the principal components of the correlation matrix, variates with the desired mean, magnitude, and correlation can be generated through linear transforms which include the eigenvalues and the eigenvectors of the correlation matrix. The conversion of the data to a non orthogonal basis uses a compound linear transformation which distorts or stretches the data space. Hence, the correlated data does not have the same properties as the uncorrelated data used to generate it. This phenomena is responsible for seemingly strange observations such as the fact that the marginal distributions of the correlated data can be quite different from the distributions used to generate the data. The joint effect of statistical distributions and correlation remains a fertile area for further research. In terms of application to cost estimating, the geometric approach demonstrates that the estimator must have data and must understand that data in order to properly choose the correlation matrix appropriate for a given estimate. There is a general feeling by employers and managers that the field of cost requires little technical or mathematical background. Contrary to that opinion, this paper demonstrates that a background in mathematics equivalent to that needed for typical engineering and scientific disciplines at the masters or doctorate level is appropriate within the field of cost risk.

Laminates and reinforced metals

NASA Technical Reports Server (NTRS)

Chamis, C. C.

1980-01-01

A selective review is presented of the state of the art of metallic laminates and fiber reinforced metals called metallic matrix laminates (MMLs). Design and analysis procedures that are used for, and typical structural components that have been made from MMLs are emphasized. Selected MMLs, constituent materials, typical material properties and fabrication procedures are briefly described, including hybrids and superhybrids. Advantages, disadvantages, and special considerations required during design, analysis, and fabrication of MMLs are examined. Tabular and graphical data are included to illustrate key aspects of MMLs. Appropriate references are cited to provide a selective bibliography of a rapidly expanding and very promising research and development field.

Extracellular matrix remodeling and matrix metalloproteinases (ajMMP-2 like and ajMMP-16 like) characterization during intestine regeneration of sea cucumber Apostichopus japonicus.

PubMed

Miao, Ting; Wan, Zixuan; Sun, Lina; Li, Xiaoni; Xing, Lili; Bai, Yucen; Wang, Fang; Yang, Hongsheng

2017-10-01

Remodeling of extracellular matrix (ECM) regulated by matrix metalloproteinases (MMPs) is essential for tissue regeneration. In the present study, we used immunohistochemistry (IHC) techniques against ECM components to reveal changes of ECM during intestine regeneration of Apostichopus japonicus. The expression of collagen I and laminin reduced apparently from the eviscerated intestine, while fibronectin exhibited continuous expression in all regeneration stages observed. Meanwhile, we cloned two MMP genes from A. japonicus by RACE PCR. The full-length cDNA of ajMMP-2 like is 2733bp and contains a predicted open reading frame (ORF) of 1716bp encoding 572 amino acids. The full-length cDNA of ajMMP-16 like is 2705bp and contains an ORF of 1452bp encoding 484 amino acids. The predicted protein sequences of each MMP contain two conserved domains, ZnMc_MMP and HX. Homology and phylogenetic analysis revealed that ajMMP-2 like and ajMMP-16 like share high sequence similarity with MMP-2 and MMP-16 from Strongylocentrotus purpuratus, respectively. Then we investigated spatio-temporal expression of ajMMP-2 like and ajMMP-16 like during different regeneration stages by qRT-PCR and IHC. The expression pattern of them showed a roughly opposite trend from that of ECM components. According to our results, a fibronectin-dominate temporary matrix is created in intestine regeneration, and it might provide structural integrity for matrix and promote cell movement. We also hypothesize that ajMMP-2 like and ajMMP-16 like could accelerate cell migration and regulate interaction between ECM components and growth factors. This work provides new evidence of ECM and MMPs involvement in sea cucumber regeneration. Copyright © 2017 Elsevier Inc. All rights reserved.

Diffusion relaxation times of nonequilibrium isolated small bodies and their solid phase ensembles to equilibrium states

NASA Astrophysics Data System (ADS)

Tovbin, Yu. K.

2017-08-01

The possibility of obtaining analytical estimates in a diffusion approximation of the times needed by nonequilibrium small bodies to relax to their equilibrium states based on knowledge of the mass transfer coefficient is considered. This coefficient is expressed as the product of the self-diffusion coefficient and the thermodynamic factor. A set of equations for the diffusion transport of mixture components is formulated, characteristic scales of the size of microheterogeneous phases are identified, and effective mass transfer coefficients are constructed for them. Allowing for the developed interface of coexisting and immiscible phases along with the porosity of solid phases is discussed. This approach can be applied to the diffusion equalization of concentrations of solid mixture components in many physicochemical systems: the mutual diffusion of components in multicomponent systems (alloys, semiconductors, solid mixtures of inert gases) and the mass transfer of an absorbed mobile component in the voids of a matrix consisting of slow components or a mixed composition of mobile and slow components (e.g., hydrogen in metals, oxygen in oxides, and the transfer of molecules through membranes of different natures, including polymeric).

Mathematical Modeling of Cancer Invasion: The Role of Membrane-Bound Matrix Metalloproteinases

PubMed Central

Deakin, Niall E.; Chaplain, Mark A. J.

2013-01-01

One of the hallmarks of cancer growth and metastatic spread is the process of local invasion of the surrounding tissue. Cancer cells achieve protease-dependent invasion by the secretion of enzymes involved in proteolysis. These overly expressed proteolytic enzymes then proceed to degrade the host tissue allowing the cancer cells to disseminate throughout the microenvironment by active migration and interaction with components of the extracellular matrix (ECM) such as collagen. In this paper we develop a mathematical model of cancer invasion which consider the role of matrix metalloproteinases (MMPs). Specifically our model will focus on two distinct types of MMP, i.e., soluble, diffusible MMPs (e.g., MMP-2) and membrane-bound MMPs (e.g., MT1-MMP), and the roles each of these plays in cancer invasion. The implications of MMP-2 activation by MMP-14 and the tissue inhibitor of metalloproteinases-2 are considered alongside the effect the architecture of the matrix may have when applied to a model of cancer invasion. Elements of the ECM architecture investigated include pore size of the matrix, since in some highly dense collagen structures such as breast tissue, the cancer cells are unable to physically fit through a porous region, and the crosslinking of collagen fibers. In this scenario, cancer cells rely on membrane-bound MMPs to forge a path through which degradation by other MMPs and movement of cancer cells becomes possible. PMID:23565505

A network view on psychiatric disorders: network clusters of symptoms as elementary syndromes of psychopathology.

PubMed

Goekoop, Rutger; Goekoop, Jaap G

2014-01-01

The vast number of psychopathological syndromes that can be observed in clinical practice can be described in terms of a limited number of elementary syndromes that are differentially expressed. Previous attempts to identify elementary syndromes have shown limitations that have slowed progress in the taxonomy of psychiatric disorders. To examine the ability of network community detection (NCD) to identify elementary syndromes of psychopathology and move beyond the limitations of current classification methods in psychiatry. 192 patients with unselected mental disorders were tested on the Comprehensive Psychopathological Rating Scale (CPRS). Principal component analysis (PCA) was performed on the bootstrapped correlation matrix of symptom scores to extract the principal component structure (PCS). An undirected and weighted network graph was constructed from the same matrix. Network community structure (NCS) was optimized using a previously published technique. In the optimal network structure, network clusters showed a 89% match with principal components of psychopathology. Some 6 network clusters were found, including "Depression", "Mania", "Anxiety", "Psychosis", "Retardation", and "Behavioral Disorganization". Network metrics were used to quantify the continuities between the elementary syndromes. We present the first comprehensive network graph of psychopathology that is free from the biases of previous classifications: a 'Psychopathology Web'. Clusters within this network represent elementary syndromes that are connected via a limited number of bridge symptoms. Many problems of previous classifications can be overcome by using a network approach to psychopathology.

Limitations in Bonding to Dentin and Experimental Strategies to Prevent Bond Degradation

PubMed Central

Liu, Y.; Tjäderhane, L.; Breschi, L.; Mazzoni, A.; Li, N.; Mao, J.; Pashley, D.H.; Tay, F.R.

2011-01-01

The limited durability of resin-dentin bonds severely compromises the lifetime of tooth-colored restorations. Bond degradation occurs via hydrolysis of suboptimally polymerized hydrophilic resin components and degradation of water-rich, resin-sparse collagen matrices by matrix metalloproteinases (MMPs) and cysteine cathepsins. This review examined data generated over the past three years on five experimental strategies developed by different research groups for extending the longevity of resin-dentin bonds. They include: (1) increasing the degree of conversion and esterase resistance of hydrophilic adhesives; (2) the use of broad-spectrum inhibitors of collagenolytic enzymes, including novel inhibitor functional groups grafted to methacrylate resins monomers to produce anti-MMP adhesives; (3) the use of cross-linking agents for silencing the activities of MMP and cathepsins that irreversibly alter the 3-D structures of their catalytic/allosteric domains; (4) ethanol wet-bonding with hydrophobic resins to completely replace water from the extrafibrillar and intrafibrillar collagen compartments and immobilize the collagenolytic enzymes; and (5) biomimetic remineralization of the water-filled collagen matrix using analogs of matrix proteins to progressively replace water with intrafibrillar and extrafibrillar apatites to exclude exogenous collagenolytic enzymes and fossilize endogenous collagenolytic enzymes. A combination of several of these strategies should result in overcoming the critical barriers to progress currently encountered in dentin bonding. PMID:21220360

Quantification of collagen contraction in three-dimensional cell culture.

PubMed

Kopanska, Katarzyna S; Bussonnier, Matthias; Geraldo, Sara; Simon, Anthony; Vignjevic, Danijela; Betz, Timo

2015-01-01

Many different cell types including fibroblasts, smooth muscle cells, endothelial cells, and cancer cells exert traction forces on the fibrous components of the extracellular matrix. This can be observed as matrix contraction both macro- and microscopically in three-dimensional (3D) tissues models such as collagen type I gels. The quantification of local contraction at the micron scale, including its directionality and speed, in correlation with other parameters such as cell invasion, local protein or gene expression, can provide useful information to study wound healing, organism development, and cancer metastasis. In this article, we present a set of tools to quantify the flow dynamics of collagen contraction, induced by cells migrating out of a multicellular cancer spheroid into a three-dimensional (3D) collagen matrix. We adapted a pseudo-speckle technique that can be applied to bright-field and fluorescent microscopy time series. The image analysis presented here is based on an in-house written software developed in the Matlab (Mathworks) programming environment. The analysis program is freely available from GitHub following the link: http://dx.doi.org/10.5281/zenodo.10116. This tool provides an automatized technique to measure collagen contraction that can be utilized in different 3D cellular systems. Copyright © 2015 Elsevier Inc. All rights reserved.

Kinetics and thermodynamics of irreversible inhibition of matrix metalloproteinase 2 by a Co(III) Schiff base complex

PubMed Central

Harney, Allison S.; Sole, Laura B.

2012-01-01

Cobalt(III) Schiff base complexes have been used as potent inhibitors of protein function through the coordination to histidine residues essential for activity. The kinetics and thermodynamics of the binding mechanism of Co(acacen)(NH3)2Cl [Co(acacen); where H2acacen is bis(acetylacetone)ethylenediimine] enzyme inhibition has been examined through the inactivation of matrix metalloproteinase 2 (MMP-2) protease activity. Co(acacen) is an irreversible inhibitor that exhibits time- and concentration-dependent inactivation of MMP-2. Co(acacen) inhibition of MMP-2 is temperature-dependent, with the inactivation increasing with temperature. Examination of the formation of the transition state for the MMP-2/Co(acacen) complex was determined to have a positive entropy component indicative of greater disorder in the MMP-2/Co(acacen) complex than in the reactants. With further insight into the mechanism of Co(acacen) complexes, Co(III) Schiff base complex protein inactivators can be designed to include features regulating activity and protein specificity. This approach is widely applicable to protein targets that have been identified to have clinical significance, including matrix metalloproteinases. The mechanistic information elucidated here further emphasizes the versatility and utility of Co(III) Schiff base complexes as customizable protein inhibitors. PMID:22729838

Minimum number of measurements for evaluating soursop (Annona muricata L.) yield.

PubMed

Sánchez, C F B; Teodoro, P E; Londoño, S; Silva, L A; Peixoto, L A; Bhering, L L

2017-05-31

Repeatability studies on fruit species are of great importance to identify the minimum number of measurements necessary to accurately select superior genotypes. This study aimed to identify the most efficient method to estimate the repeatability coefficient (r) and predict the minimum number of measurements needed for a more accurate evaluation of soursop (Annona muricata L.) genotypes based on fruit yield. Sixteen measurements of fruit yield from 71 soursop genotypes were carried out between 2000 and 2016. In order to estimate r with the best accuracy, four procedures were used: analysis of variance, principal component analysis based on the correlation matrix, principal component analysis based on the phenotypic variance and covariance matrix, and structural analysis based on the correlation matrix. The minimum number of measurements needed to predict the actual value of individuals was estimated. Principal component analysis using the phenotypic variance and covariance matrix provided the most accurate estimates of both r and the number of measurements required for accurate evaluation of fruit yield in soursop. Our results indicate that selection of soursop genotypes with high fruit yield can be performed based on the third and fourth measurements in the early years and/or based on the eighth and ninth measurements at more advanced stages.

Robust Principal Component Analysis Regularized by Truncated Nuclear Norm for Identifying Differentially Expressed Genes.

PubMed

Wang, Ya-Xuan; Gao, Ying-Lian; Liu, Jin-Xing; Kong, Xiang-Zhen; Li, Hai-Jun

2017-09-01

Identifying differentially expressed genes from the thousands of genes is a challenging task. Robust principal component analysis (RPCA) is an efficient method in the identification of differentially expressed genes. RPCA method uses nuclear norm to approximate the rank function. However, theoretical studies showed that the nuclear norm minimizes all singular values, so it may not be the best solution to approximate the rank function. The truncated nuclear norm is defined as the sum of some smaller singular values, which may achieve a better approximation of the rank function than nuclear norm. In this paper, a novel method is proposed by replacing nuclear norm of RPCA with the truncated nuclear norm, which is named robust principal component analysis regularized by truncated nuclear norm (TRPCA). The method decomposes the observation matrix of genomic data into a low-rank matrix and a sparse matrix. Because the significant genes can be considered as sparse signals, the differentially expressed genes are viewed as the sparse perturbation signals. Thus, the differentially expressed genes can be identified according to the sparse matrix. The experimental results on The Cancer Genome Atlas data illustrate that the TRPCA method outperforms other state-of-the-art methods in the identification of differentially expressed genes.

Flax Fiber Hydrophobic Extract Inhibits Human Skin Cells Inflammation and Causes Remodeling of Extracellular Matrix and Wound Closure Activation

PubMed Central

Styrczewska, Monika; Kostyn, Anna; Kulma, Anna; Majkowska-Skrobek, Grazyna; Augustyniak, Daria; Prescha, Anna; Czuj, Tadeusz; Szopa, Jan

2015-01-01

Inflammation is the basis of many diseases, with chronic wounds amongst them, limiting cell proliferation and tissue regeneration. Our previous preclinical study of flax fiber applied as a wound dressing and analysis of its components impact on the fibroblast transcriptome suggested flax fiber hydrophobic extract use as an anti-inflammatory and wound healing preparation. The extract contains cannabidiol (CBD), phytosterols, and unsaturated fatty acids, showing great promise in wound healing. In in vitro proliferation and wound closure tests the extract activated cell migration and proliferation. The activity of matrix metalloproteinases in skin cells was increased, suggesting activation of extracellular components remodeling. The expression of cytokines was diminished by the extract in a cannabidiol-dependent manner, but β-sitosterol can act synergistically with CBD in inflammation inhibition. Extracellular matrix related genes were also analyzed, considering their importance in further stages of wound healing. The extract activated skin cell matrix remodeling, but the changes were only partially cannabidiol- and β-sitosterol-dependent. The possible role of fatty acids also present in the extract is suggested. The study shows the hydrophobic flax fiber components as wound healing activators, with anti-inflammatory cannabidiol acting in synergy with sterols, and migration and proliferation promoting agents, some of which still require experimental identification. PMID:26347154

Elasticity-mediated nematiclike bacterial organization in model extracellular DNA matrix.

PubMed

Smalyukh, Ivan I; Butler, John; Shrout, Joshua D; Parsek, Matthew R; Wong, Gerard C L

2008-09-01

DNA is a common extracellular matrix component of bacterial biofilms. We find that bacteria can spontaneously order in a matrix of aligned concentrated DNA, in which rod-shaped cells of Pseudomonas aeruginosa follow the orientation of extended DNA chains. The alignment of bacteria is ensured by elasticity and liquid crystalline properties of the DNA matrix. These findings show how behavior of planktonic bacteria may be modified in extracellular polymeric substances of biofilms and illustrate the potential of using complex fluids to manipulate embedded nanosized and microsized active particles.

In situ localization of nucleolin in the plant nucleolar matrix.

PubMed

Minguez, A; Moreno Diaz de la Espina, S

1996-01-10

The analysis of isolated nucleolar matrices from onion cells by light and electron microscopy, 2-D separation of proteins, and confocal microscopy has confirmed the existence of an organized nucleolar matrix with a complex protein composition to which are attached the insoluble processing complexes. In the present work, we present evidence from immunoblotting, immunofluorescence, immunogold labeling, and preferential cytochemical staining with bismuth salts that an insoluble fraction of the multifunctional protein nucleolin, is a component of the onion nucleolar matrix, and analyse its ultrastructural distribution in the described domains of the matrix.

A Matrix for Processing Descriptive and Judgmental Data for Use with the Learning Area Sections of the "Evaluative Criteria," Sixth Edition.

ERIC Educational Resources Information Center

Pace, Vernon D.; Buser, Robert L.

1990-01-01

Presents a matrix that can be used by accreditation team members to gather, organize, analyze, and report descriptive and evaluative information about instructional support components, teacher observations/interviews, and curriculum evaluation. (DMM)

Poisoning of mixed matrix membranes by fermentation components in pervaporation of ethanol

USDA-ARS?s Scientific Manuscript database

Pervaporation is an alternative to distillation for recovering ethanol produced by fermentation of grains and biomass. Ethanol-selective mixed matrix membranes of the hydrophobic zeolite ZSM-5 in polydimethylsiloxane (PDMS) have superior performance compared to pure PDMS membranes in pervaporation o...

The Candida albicans Biofilm Matrix: Composition, Structure and Function.

PubMed

Pierce, Christopher G; Vila, Taissa; Romo, Jesus A; Montelongo-Jauregui, Daniel; Wall, Gina; Ramasubramanian, Anand; Lopez-Ribot, Jose L

2017-03-01

A majority of infections caused by Candida albicans -the most frequent fungal pathogen-are associated with biofilm formation. A salient feature of C. albicans biofilms is the presence of the biofilm matrix. This matrix is composed of exopolymeric materials secreted by sessile cells within the biofilm, in which all classes of macromolecules are represented, and provides protection against environmental challenges. In this review, we summarize the knowledge accumulated during the last two decades on the composition, structure, and function of the C. albicans biofilm matrix. Knowledge of the matrix components, its structure, and function will help pave the way to novel strategies to combat C. albicans biofilm infections.

The Candida albicans Biofilm Matrix: Composition, Structure and Function

PubMed Central

Pierce, Christopher G.; Vila, Taissa; Romo, Jesus A.; Montelongo-Jauregui, Daniel; Wall, Gina; Ramasubramanian, Anand; Lopez-Ribot, Jose L.

2017-01-01

A majority of infections caused by Candida albicans—the most frequent fungal pathogen—are associated with biofilm formation. A salient feature of C. albicans biofilms is the presence of the biofilm matrix. This matrix is composed of exopolymeric materials secreted by sessile cells within the biofilm, in which all classes of macromolecules are represented, and provides protection against environmental challenges. In this review, we summarize the knowledge accumulated during the last two decades on the composition, structure, and function of the C. albicans biofilm matrix. Knowledge of the matrix components, its structure, and function will help pave the way to novel strategies to combat C. albicans biofilm infections. PMID:28516088

An Application of Semi-parametric Estimator with Weighted Matrix of Data Depth in Variance Component Estimation

NASA Astrophysics Data System (ADS)

Pan, X. G.; Wang, J. Q.; Zhou, H. Y.

2013-05-01

The variance component estimation (VCE) based on semi-parametric estimator with weighted matrix of data depth has been proposed, because the coupling system model error and gross error exist in the multi-source heterogeneous measurement data of space and ground combined TT&C (Telemetry, Tracking and Command) technology. The uncertain model error has been estimated with the semi-parametric estimator model, and the outlier has been restrained with the weighted matrix of data depth. On the basis of the restriction of the model error and outlier, the VCE can be improved and used to estimate weighted matrix for the observation data with uncertain model error or outlier. Simulation experiment has been carried out under the circumstance of space and ground combined TT&C. The results show that the new VCE based on the model error compensation can determine the rational weight of the multi-source heterogeneous data, and restrain the outlier data.

Combined effect of matrix cracking and stress-free edge on delamination

NASA Technical Reports Server (NTRS)

Salpekar, S. A.; Obrien, T. K.

1990-01-01

The effect of the stress-free edge on the growth of local delaminations initiating from a matrix crack in (0 sub 2/90 sub 4) sub s and (+ or - 45.90 sub 4) sub s glass epoxy laminates is investigated using 3-D finite element analysis. The presence of high interlaminar normal stresses at the intersection (corner) of the matrix crack with the stress-free edge, suggests that a mode I delamination may initiate at the corners. The strain energy release rates (G) were calculated by modeling a uniform through-width delamination and two inclined delaminations at 10.6 deg and 45 deg to the matrix crack. All components of G have high values near the free edges. The mode I component of G is high at small delamination length and becomes zero for a delamination length of one-ply thickness. The total G values near the free edge agreed well with previously derived closed form solution. The quasi-3D solutions agreed well with the 3-D interior solutions.

Combined effect of matrix cracking and stress-free edge on delamination

NASA Technical Reports Server (NTRS)

Salpekar, Satish A.; O'Brien, T. K.

1991-01-01

The effect of the stress-free edge on the growth of local delaminations initiating from a matrix crack in (O sub 2/90 sub 4) sub s and (+/- 45.90 sub 4) sub s glass epoxy laminates is investigated using 3D finite element analysis. The presence of high interlaminar normal stresses at the intersection (corner) of the matrix crack with the stress-free edge, suggests that a mode I delamination may initiate at the corners. The strain energy release rates (G) were calculated by modeling a uniform through-width delamination and two inclined delaminations at 10.6 deg and 45 deg to the matrix crack. All components of G have high values near the free edges. The mode I component of G is high at small delamination length and becomes zero for a delamination length of one-ply thickness. The total G values near the free edge agreed well with previously derived closed form solution. The quasi-3D solutions agreed well with the 3D interior solutions.

The roles of biofilm matrix polysaccharide Psl in mucoid Pseudomonas aeruginosa biofilms.

PubMed

Ma, Luyan; Wang, Shiwei; Wang, Di; Parsek, Matthew R; Wozniak, Daniel J

2012-07-01

The opportunistic pathogen Pseudomonas aeruginosa causes life-threatening, persistent infections in patients with cystic fibrosis (CF). Persistence is attributed to the ability of these bacteria to form structured communities (biofilms). Biofilms rely on an extracellular polymeric substances matrix to maintain structure. Psl exopolysaccharide is a key matrix component of nonmucoid biofilms, yet the role of Psl in mucoid biofilms is unknown. In this report, using a variety of mutants in a mucoid P. aeruginosa background, we found that deletion of Psl-encoding genes dramatically decreased their biofilm formation ability, indicating that Psl is also a critical matrix component of mucoid biofilms. Our data also suggest that the overproduction of alginate leads to mucoid biofilms, which occupy more space, whereas Psl-dependent biofilms are densely packed. These data suggest that Psl polysaccharide may have significant contributions in biofilm persistence in patients with CF and may be helpful for designing therapies for P. aeruginosa CF infection. © 2012 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

Escherichia coli Biofilms Have an Organized and Complex Extracellular Matrix Structure

PubMed Central

Hung, Chia; Zhou, Yizhou; Pinkner, Jerome S.; Dodson, Karen W.; Crowley, Jan R.; Heuser, John; Chapman, Matthew R.; Hadjifrangiskou, Maria; Henderson, Jeffrey P.; Hultgren, Scott J.

2013-01-01

ABSTRACT Bacterial biofilms are ubiquitous in nature, and their resilience is derived in part from a complex extracellular matrix that can be tailored to meet environmental demands. Although common developmental stages leading to biofilm formation have been described, how the extracellular components are organized to allow three-dimensional biofilm development is not well understood. Here we show that uropathogenic Escherichia coli (UPEC) strains produce a biofilm with a highly ordered and complex extracellular matrix (ECM). We used electron microscopy (EM) techniques to image floating biofilms (pellicles) formed by UPEC. EM revealed intricately constructed substructures within the ECM that encase individual, spatially segregated bacteria with a distinctive morphology. Mutational and biochemical analyses of these biofilms confirmed curli as a major matrix component and revealed important roles for cellulose, flagella, and type 1 pili in pellicle integrity and ECM infrastructure. Collectively, the findings of this study elucidated that UPEC pellicles have a highly organized ultrastructure that varies spatially across the multicellular community. PMID:24023384

Hydrogel derived from porcine decellularized nerve tissue as a promising biomaterial for repairing peripheral nerve defects.

PubMed

Lin, Tao; Liu, Sheng; Chen, Shihao; Qiu, Shuai; Rao, Zilong; Liu, Jianghui; Zhu, Shuang; Yan, Liwei; Mao, Haiquan; Zhu, Qingtang; Quan, Daping; Liu, Xiaolin

2018-06-01

Decellularized matrix hydrogels derived from tissues or organs have been used for tissue repair due to their biocompatibility, tunability, and tissue-specific extracellular matrix (ECM) components. However, the preparation of decellularized peripheral nerve matrix hydrogels and their use to repair nerve defects have not been reported. Here, we developed a hydrogel from porcine decellularized nerve matrix (pDNM-G), which was confirmed to have minimal DNA content and retain collagen and glycosaminoglycans content, thereby allowing gelatinization. The pDNM-G exhibited a nanofibrous structure similar to that of natural ECM, and a ∼280-Pa storage modulus at 10 mg/mL similar to that of native neural tissues. Western blot and liquid chromatography tandem mass spectrometry analysis revealed that the pDNM-G consisted mostly of ECM proteins and contained primary ECM-related proteins, including fibronectin and collagen I and IV). In vitro experiments showed that pDNM-G supported Schwann cell proliferation and preserved cell morphology. Additionally, in a 15-mm rat sciatic nerve defect model, pDNM-G was combined with electrospun poly(lactic-acid)-co-poly(trimethylene-carbonate)conduits to bridge the defect, which did not elicit an adverse immune response and promoted the activation of M2 macrophages associated with a constructive remodeling response. Morphological analyses and electrophysiological and functional examinations revealed that the regenerative outcomes achieved by pDNM-G were superior to those by empty conduits and closed to those using rat decellularized nerve matrix allograft scaffolds. These findings indicated that pDNM-G, with its preserved ECM composition and nanofibrous structure, represents a promising biomaterial for peripheral nerve regeneration. Decellularized nerve allografts have been widely used to treat peripheral nerve injury. However, given their limited availability and lack of bioactive factors, efforts have been made to improve the efficacy of decellularized nerve allograft for nerve regeneration, with limited success. Xenogeneic decellularized tissue matrices or hydrogels have been widely used for surgical applications owing to their ease of harvesting and low immunogenicity. Moreover, decellularized tissue matrix hydrogels show good biocompatibility and are highly tunable. In this study, we prepared a porcine decellularized nerve matrix (pDNM-G) and evaluated its potential for promoting nerve regeneration. Our results demonstrate that pDNM-G can support Schwann cell proliferation and peripheral nerve regeneration by means of residual primary extracellular matrix components and nano-fibrous structure features. Copyright © 2018 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Advanced Constituents and Processes for Ceramic Composite Engine Components

NASA Technical Reports Server (NTRS)

Yun, H. M.; DiCarlo, J. A.; Bhatt, R. T.

2004-01-01

The successful replacement of metal alloys by ceramic matrix composites (CMC) in hot-section engine components will depend strongly on optimizing the processes and properties of the CMC microstructural constituents so that they can synergistically provide the total CMC system with improved temperature capability and with the key properties required by the components for long-term structural service. This presentation provides the results of recent activities at NASA aimed at developing advanced silicon carbide (Sic) fiber-reinforced hybrid Sic matrix composite systems that can operate under mechanical loading and oxidizing conditions for hundreds of hours at 2400 and 2600 F, temperatures well above current metal capability. These SiC/SiC composite systems are lightweight (-30% metal density) and, in comparison to monolithic ceramics and carbon fiber-reinforced ceramic composites, are able to reliably retain their structural properties for long times under aggressive engine environments. It is shown that the improved temperature capability of the SiC/SiC systems is related first to the NASA development of the Sylramic-iBN Sic fiber, which displays high thermal stability, creep resistance, rupture resistance, and thermal conductivity, and possesses an in-situ grown BN surface layer for added environmental durability. This fiber is simply derived from Sylramic Sic fiber type that is currently produced at ATK COI Ceramics. Further capability is then derived by using chemical vapor infiltration (CVI) to form the initial portion of the hybrid Sic matrix. Because of its high creep resistance and thermal conductivity, the CVI Sic matrix is a required base constituent for all the high temperature SiC/SiC systems. By subsequently thermo- mechanical-treating the CMC preform, which consists of the S ylramic-iBN fibers and CVI Sic matrix, process-related defects in the matrix are removed, further improving matrix and CMC creep resistance and conductivity.

Matrix metalloproteinases and epidermal wound repair.

PubMed

Martins, Vera L; Caley, Matthew; O'Toole, Edel A

2013-02-01

Epidermal wound healing is a complex and highly coordinated process where several different cell types and molecules, such as growth factors and extracellular matrix (ECM) components, play an important role. Among the many proteins that are essential for the restoration of tissue integrity is the metalloproteinase (MMP) family. MMPs can act on ECM and non-ECM components affecting degradation and modulation of the ECM, growth-factor activation and cell-cell and cell-matrix signalling. MMPs are secreted by different cell types such as keratinocytes, fibroblasts and inflammatory cells at different stages and locations during wound healing, thereby regulating this process in a very coordinated and controlled way. In this article, we review the role of MMPs and their inhibitors (TIMPs), as well as the disintegrin and metalloproteinase with the thrombospondin motifs (ADAMs) family, in epithelial wound repair.

Temporal evolution of financial-market correlations.

PubMed

Fenn, Daniel J; Porter, Mason A; Williams, Stacy; McDonald, Mark; Johnson, Neil F; Jones, Nick S

2011-08-01

We investigate financial market correlations using random matrix theory and principal component analysis. We use random matrix theory to demonstrate that correlation matrices of asset price changes contain structure that is incompatible with uncorrelated random price changes. We then identify the principal components of these correlation matrices and demonstrate that a small number of components accounts for a large proportion of the variability of the markets that we consider. We characterize the time-evolving relationships between the different assets by investigating the correlations between the asset price time series and principal components. Using this approach, we uncover notable changes that occurred in financial markets and identify the assets that were significantly affected by these changes. We show in particular that there was an increase in the strength of the relationships between several different markets following the 2007-2008 credit and liquidity crisis.

Temporal evolution of financial-market correlations

NASA Astrophysics Data System (ADS)

Fenn, Daniel J.; Porter, Mason A.; Williams, Stacy; McDonald, Mark; Johnson, Neil F.; Jones, Nick S.

2011-08-01

We investigate financial market correlations using random matrix theory and principal component analysis. We use random matrix theory to demonstrate that correlation matrices of asset price changes contain structure that is incompatible with uncorrelated random price changes. We then identify the principal components of these correlation matrices and demonstrate that a small number of components accounts for a large proportion of the variability of the markets that we consider. We characterize the time-evolving relationships between the different assets by investigating the correlations between the asset price time series and principal components. Using this approach, we uncover notable changes that occurred in financial markets and identify the assets that were significantly affected by these changes. We show in particular that there was an increase in the strength of the relationships between several different markets following the 2007-2008 credit and liquidity crisis.

Extracellular Matrix and Dermal Fibroblast Function in the Healing Wound

PubMed Central

Tracy, Lauren E.; Minasian, Raquel A.; Caterson, E.J.

2016-01-01

Significance: Fibroblasts play a critical role in normal wound healing. Various extracellular matrix (ECM) components, including collagens, fibrin, fibronectin, proteoglycans, glycosaminoglycans, and matricellular proteins, can be considered potent protagonists of fibroblast survival, migration, and metabolism. Recent Advances: Advances in tissue culture, tissue engineering, and ex vivo models have made the examination and precise measurements of ECM components in wound healing possible. Likewise, the development of specific transgenic animal models has created the opportunity to characterize the role of various ECM molecules in healing wounds. In addition, the recent characterization of new ECM molecules, including matricellular proteins, dermatopontin, and FACIT collagens (Fibril-Associated Collagens with Interrupted Triple helices), further demonstrates our cursory knowledge of the ECM in coordinated wound healing. Critical Issues: The manipulation and augmentation of ECM components in the healing wound is emerging in patient care, as demonstrated by the use of acellular dermal matrices, tissue scaffolds, and wound dressings or topical products bearing ECM proteins such as collagen, hyaluronan (HA), or elastin. Once thought of as neutral structural proteins, these molecules are now known to directly influence many aspects of cellular wound healing. Future Directions: The role that ECM molecules, such as CCN2, osteopontin, and secreted protein, acidic and rich in cysteine, play in signaling homing of fibroblast progenitor cells to sites of injury invites future research as we continue investigating the heterotopic origin of certain populations of fibroblasts in a healing wound. Likewise, research into differently sized fragments of the same polymeric ECM molecule is warranted as we learn that fragments of molecules such as HA and tenascin-C can have opposing effects on dermal fibroblasts. PMID:26989578

Self-interaction of NPM1 modulates multiple mechanisms of liquid-liquid phase separation.

PubMed

Mitrea, Diana M; Cika, Jaclyn A; Stanley, Christopher B; Nourse, Amanda; Onuchic, Paulo L; Banerjee, Priya R; Phillips, Aaron H; Park, Cheon-Gil; Deniz, Ashok A; Kriwacki, Richard W

2018-02-26

Nucleophosmin (NPM1) is an abundant, oligomeric protein in the granular component of the nucleolus with roles in ribosome biogenesis. Pentameric NPM1 undergoes liquid-liquid phase separation (LLPS) via heterotypic interactions with nucleolar components, including ribosomal RNA (rRNA) and proteins which display multivalent arginine-rich linear motifs (R-motifs), and is integral to the liquid-like nucleolar matrix. Here we show that NPM1 can also undergo LLPS via homotypic interactions between its polyampholytic intrinsically disordered regions, a mechanism that opposes LLPS via heterotypic interactions. Using a combination of biophysical techniques, including confocal microscopy, SAXS, analytical ultracentrifugation, and single-molecule fluorescence, we describe how conformational changes within NPM1 control valency and switching between the different LLPS mechanisms. We propose that this newly discovered interplay between multiple LLPS mechanisms may influence the direction of vectorial pre-ribosomal particle assembly within, and exit from the nucleolus as part of the ribosome biogenesis process.

Saccharide sensing molecules having enhanced fluorescent properties

DOEpatents

Satcher Jr., Joe H.; Lane, Stephen M.; Darrow, Christopher B.; Cary, Douglas R.; Tran, Joe Anh

2004-01-06

The present invention provides formulae for fluorescent compounds that have a number of properties which make them uniquely suited for use in sensors of analytes such as saccharides. The advantageous fluorescent properties include favorable excitation wavelengths, emission wavelengths, fluorescence lifetimes, and photostability. Additional advantageous properties include enhanced aqueous solubility, as well as temperature and pH sensitivity. The compound comprises an aryl or a substituted phenyl botonic acid that acts as a substrate recognition component, a fluorescence switch component, and a fluorophore. Fluorescent compounds are described that are excited at wavelengths greater than 400 nm and emit at wavelengths greater than 450 nm, which is advantageous for optical transmission through skin. The fluorophore is typically selected from transition metal-ligand complexes and thiazine, oxazine, oxazone, or oxazine-one as well as anthracene compounds. The fluorescent compound can be immobilized in a glucose permeable biocompatible polymer matrix that is implantable below the skin.

Spatial variation analyses of Thematic Mapper data for the identification of linear features in agricultural landscapes

NASA Technical Reports Server (NTRS)

Pelletier, R. E.

1984-01-01

A need exists for digitized information pertaining to linear features such as roads, streams, water bodies and agricultural field boundaries as component parts of a data base. For many areas where this data may not yet exist or is in need of updating, these features may be extracted from remotely sensed digital data. This paper examines two approaches for identifying linear features, one utilizing raw data and the other classified data. Each approach uses a series of data enhancement procedures including derivation of standard deviation values, principal component analysis and filtering procedures using a high-pass window matrix. Just as certain bands better classify different land covers, so too do these bands exhibit high spectral contrast by which boundaries between land covers can be delineated. A few applications for this kind of data are briefly discussed, including its potential in a Universal Soil Loss Equation Model.

Attachment of Actinobacillus suis H91-0380 and Its Isogenic Adhesin Mutants to Extracellular Matrix Components of the Tonsils of the Soft Palate of Swine

PubMed Central

Bujold, Adina R.

2016-01-01

Tonsils conduct immune surveillance of antigens entering the upper respiratory tract. Despite their immunological function, they are also sites of persistence and invasion of bacterial pathogens. Actinobacillus suis is a common resident of the tonsils of the soft palate in pigs, but under certain circumstances it can invade, causing septicemia and related sequelae. Twenty-four putative adhesins are predicted in the A. suis genome, but to date, little is known about how they might participate in colonization or invasion. To better understand these processes, swine tonsil lysates were characterized by mass spectrometry. Fifty-nine extracellular matrix (ECM) proteins were identified, including small leucine-rich proteoglycans, integrins, and other cell surface receptors. Additionally, attachment of the wild type and 3 adhesin mutants to 5 ECM components was evaluated. Exponential cultures of wild-type A. suis adhered significantly more than stationary cultures to all ECM components studied except collagen I. During exponential growth, the A. suis Δflp1 mutant attached less to collagen IV while the ΔompA mutant attached less to all ECMs. The ΔcomE1 strain attached less to collagen IV, fibronectin, and vitronectin during exponential growth and exhibited differential attachment to collagen I over short adherence time points. These results suggest that Flp1, OmpA, and ComE1 are important during early stages of attachment to ECM components found in tonsils, which supports the notion that other adhesins have compensatory effects during later stages of attachment. PMID:27481253

Visual perception of landscape: sex and personality differences

Treesearch

A. Macia

1979-01-01

The present study established relationships between individual differences and subjective evaluation of different kinds of landscapes. These were the first three principle components of the five components obtained from a matrix of coincidences. The three components used were: 1) natural versus humanized landscapes; 2) pleasant versus rough landscapes; 3) straight and...

Cracking evolution behaviors of lightweight materials based on in situ synchrotron X-ray tomography: A review

NASA Astrophysics Data System (ADS)

Luo, Y.; Wu, S. C.; Hu, Y. N.; Fu, Y. N.

2018-03-01

Damage accumulation and failure behaviors are crucial concerns during the design and service of a critical component, leading researchers and engineers to thoroughly identifying the crack evolution. Third-generation synchrotron radiation X-ray computed microtomography can be used to detect the inner damage evolution of a large-density material or component. This paper provides a brief review of studying the crack initiation and propagation inside lightweight materials with advanced synchrotron three-dimensional (3D) X-ray imaging, such as aluminum materials. Various damage modes under both static and dynamic loading are elucidated for pure aluminum, aluminum alloy matrix, aluminum alloy metal matrix composite, and aluminum alloy welded joint. For aluminum alloy matrix, metallurgical defects (porosity, void, inclusion, precipitate, etc.) or artificial defects (notch, scratch, pit, etc.) strongly affect the crack initiation and propagation. For aluminum alloy metal matrix composites, the fracture occurs either from the particle debonding or voids at the particle/matrix interface, and the void evolution is closely related with fatigued cycles. For the hybrid laser welded aluminum alloy, fatigue cracks usually initiate from gas pores located at the surface or sub-surface and gradually propagate to a quarter ellipse or a typical semi-ellipse profile.

The Development of Multicultural Counselling Competencies (MCC) Training Module Based on MCC Matrix Model by Sue et al. (1992)

ERIC Educational Resources Information Center

Anuar, Azad Athahiri; Rozubi, Norsayyidatina Che; Abdullah, Haslee Sharil

2015-01-01

The aims of this study were to develop and validate a MCC training module for trainee counselor based on MCC matrix model by Sue et al. (1992). This module encompassed five sub modules and 11 activities developed along the concepts and components of the MCC matrix model developed by Sue, Arredondo dan McDavis (1992). The design method used in this…

Scaffolds for peripheral nerve repair and reconstruction.

PubMed

Yi, Sheng; Xu, Lai; Gu, Xiaosong

2018-06-02

Trauma-associated peripheral nerve defect is a widespread clinical problem. Autologous nerve grafting, the current gold standard technique for the treatment of peripheral nerve injury, has many internal disadvantages. Emerging studies showed that tissue engineered nerve graft is an effective substitute to autologous nerves. Tissue engineered nerve graft is generally composed of neural scaffolds and incorporating cells and molecules. A variety of biomaterials have been used to construct neural scaffolds, the main component of tissue engineered nerve graft. Synthetic polymers (e.g. silicone, polyglycolic acid, and poly(lactic-co-glycolic acid)) and natural materials (e.g. chitosan, silk fibroin, and extracellular matrix components) are commonly used along or together to build neural scaffolds. Many other materials, including the extracellular matrix, glass fabrics, ceramics, and metallic materials, have also been used to construct neural scaffolds. These biomaterials are fabricated to create specific structures and surface features. Seeding supporting cells and/or incorporating neurotrophic factors to neural scaffolds further improve restoration effects. Preliminary studies demonstrate that clinical applications of these neural scaffolds achieve satisfactory functional recovery. Therefore, tissue engineered nerve graft provides a good alternative to autologous nerve graft and represents a promising frontier in neural tissue engineering. Copyright © 2018 Elsevier Inc. All rights reserved.

The synthesis, characterisation and in vivo study of a bioceramic for potential tissue regeneration applications

PubMed Central

Poinern, Gérrard Eddy Jai; Brundavanam, Ravi Krishna; Thi Le, Xuan; Nicholls, Philip K.; Cake, Martin A.; Fawcett, Derek

2014-01-01

Hydroxyapatite (HAP) is a biocompatible ceramic that is currently used in a number of current biomedical applications. Recently, nanometre scale forms of HAP have attracted considerable interest due to their close similarity to the inorganic mineral component of the bone matrix found in humans. In this study ultrafine nanometre scale HAP powders were prepared via a wet precipitation method under the influence of ultrasonic irradiation. The resulting powders were compacted and sintered to form a series of ceramic pellets with a sponge-like structure with varying density and porosity. The crystalline structure, size and morphology of the powders and the porous ceramic pellets were investigated using advanced characterization techniques. The pellets demonstrated good biocompatibility, including mixed cell colonisation and matrix deposition, in vivo following surgical implantation into sheep M. latissimus dorsi. PMID:25168046

A Novel Technique to Follow Consequences of Exogenous Factors, Including Therapeutic Drugs, on Living Human Breast Epithelial Cells

DTIC Science & Technology

1999-07-01

and lipid vectors, are being tested. Concurrent with the development of procedures for live - cell imaging , we are examining the distribution of proteins...dimensional matrix. These studies have not yet begun. There are a number of procedures that must be developed and perfected in the live - cell imaging , as...components of the Wnt signaling pathway are too preliminary and require additional research prior to publication. (9) CONCLUSIONS Live cell imaging of

The Development of Environmental Barrier Coating Systems for SiC-SiC Ceramic Matrix Composites: Environment Effects on the Creep and Fatigue Resistance

NASA Technical Reports Server (NTRS)

Zhu, Dongming; Ghosn, Louis J.

2014-01-01

Topics covered include: Environmental barrier coating system development: needs, challenges and limitations; Advanced environmental barrier coating systems (EBCs) for CMC airfoils and combustors; NASA EBC systems and material system evolutions, Current turbine and combustor EBC coating emphases, Advanced development, processing, testing and modeling, EBC and EBC bond coats: recent advances; Design tool and life prediction of coated CMC components; Advanced CMC-EBC rig demonstrations; Summary and future directions.

Matrix partitioning and EOF/principal component analysis of Antarctic Sea ice brightness temperatures

NASA Technical Reports Server (NTRS)

Murray, C. W., Jr.; Mueller, J. L.; Zwally, H. J.

1984-01-01

A field of measured anomalies of some physical variable relative to their time averages, is partitioned in either the space domain or the time domain. Eigenvectors and corresponding principal components of the smaller dimensioned covariance matrices associated with the partitioned data sets are calculated independently, then joined to approximate the eigenstructure of the larger covariance matrix associated with the unpartitioned data set. The accuracy of the approximation (fraction of the total variance in the field) and the magnitudes of the largest eigenvalues from the partitioned covariance matrices together determine the number of local EOF's and principal components to be joined by any particular level. The space-time distribution of Nimbus-5 ESMR sea ice measurement is analyzed.

Distance matrix-based approach to protein structure prediction.

PubMed

Kloczkowski, Andrzej; Jernigan, Robert L; Wu, Zhijun; Song, Guang; Yang, Lei; Kolinski, Andrzej; Pokarowski, Piotr

2009-03-01

Much structural information is encoded in the internal distances; a distance matrix-based approach can be used to predict protein structure and dynamics, and for structural refinement. Our approach is based on the square distance matrix D = [r(ij)(2)] containing all square distances between residues in proteins. This distance matrix contains more information than the contact matrix C, that has elements of either 0 or 1 depending on whether the distance r (ij) is greater or less than a cutoff value r (cutoff). We have performed spectral decomposition of the distance matrices D = sigma lambda(k)V(k)V(kT), in terms of eigenvalues lambda kappa and the corresponding eigenvectors v kappa and found that it contains at most five nonzero terms. A dominant eigenvector is proportional to r (2)--the square distance of points from the center of mass, with the next three being the principal components of the system of points. By predicting r (2) from the sequence we can approximate a distance matrix of a protein with an expected RMSD value of about 7.3 A, and by combining it with the prediction of the first principal component we can improve this approximation to 4.0 A. We can also explain the role of hydrophobic interactions for the protein structure, because r is highly correlated with the hydrophobic profile of the sequence. Moreover, r is highly correlated with several sequence profiles which are useful in protein structure prediction, such as contact number, the residue-wise contact order (RWCO) or mean square fluctuations (i.e. crystallographic temperature factors). We have also shown that the next three components are related to spatial directionality of the secondary structure elements, and they may be also predicted from the sequence, improving overall structure prediction. We have also shown that the large number of available HIV-1 protease structures provides a remarkable sampling of conformations, which can be viewed as direct structural information about the dynamics. After structure matching, we apply principal component analysis (PCA) to obtain the important apparent motions for both bound and unbound structures. There are significant similarities between the first few key motions and the first few low-frequency normal modes calculated from a static representative structure with an elastic network model (ENM) that is based on the contact matrix C (related to D), strongly suggesting that the variations among the observed structures and the corresponding conformational changes are facilitated by the low-frequency, global motions intrinsic to the structure. Similarities are also found when the approach is applied to an NMR ensemble, as well as to atomic molecular dynamics (MD) trajectories. Thus, a sufficiently large number of experimental structures can directly provide important information about protein dynamics, but ENM can also provide a similar sampling of conformations. Finally, we use distance constraints from databases of known protein structures for structure refinement. We use the distributions of distances of various types in known protein structures to obtain the most probable ranges or the mean-force potentials for the distances. We then impose these constraints on structures to be refined or include the mean-force potentials directly in the energy minimization so that more plausible structural models can be built. This approach has been successfully used by us in 2006 in the CASPR structure refinement (http://predictioncenter.org/caspR).

A design of experiments test to define critical spray cleaning parameters for Brulin 815 GD and Jettacin cleaners

NASA Technical Reports Server (NTRS)

Keen, Jill M.; Evans, Kurt B.; Schiffman, Robert L.; Deweese, C. Darrell; Prince, Michael E.

1995-01-01

Experimental design testing was conducted to identify critical parameters of an aqueous spray process intended for cleaning solid rocket motor metal components (steel and aluminum). A two-level, six-parameter, fractional factorial matrix was constructed and conducted for two cleaners, Brulin 815 GD and Diversey Jettacin. The matrix parameters included cleaner temperature and concentration, wash density, wash pressure, rinse pressure, and dishwasher type. Other spray parameters: nozzle stand-off, rinse water temperature, wash and rinse time, dry conditions, and type of rinse water (deionized) were held constant. Matrix response testing utilized discriminating bond specimens (fracture energy and tensile adhesion strength) which represent critical production bond lines. Overall, Jettacin spray cleaning was insensitive to the range of conditions tested for all parameters and exhibited bond strengths significantly above the TCA test baseline for all bond lines tested. Brulin 815 was sensitive to cleaning temperature, but produced bond strengths above the TCA test baseline even at the lower temperatures. Ultimately, the experimental design database was utilized to recommend process parameter settings for future aqueous spray cleaning characterization work.

Contributions of Raman spectroscopy to the understanding of bone strength.

PubMed

Mandair, Gurjit S; Morris, Michael D

2015-01-01

Raman spectroscopy is increasingly commonly used to understand how changes in bone composition and structure influence tissue-level bone mechanical properties. The spectroscopic technique provides information on bone mineral and matrix collagen components and on the effects of various matrix proteins on bone material properties as well. The Raman spectrum of bone not only contains information on bone mineral crystallinity that is related to bone hardness but also provides information on the orientation of mineral crystallites with respect to the collagen fibril axis. Indirect information on collagen cross-links is also available and will be discussed. After a short introduction to bone Raman spectroscopic parameters and collection methodologies, advances in in vivo Raman spectroscopic measurements for animal and human subject studies will be reviewed. A discussion on the effects of aging, osteogenesis imperfecta, osteoporosis and therapeutic agents on bone composition and mechanical properties will be highlighted, including genetic mouse models in which structure-function and exercise effects are explored. Similarly, extracellular matrix proteins, proteases and transcriptional proteins implicated in the regulation of bone material properties will be reviewed.

Rapid, in Situ Synthesis of High Capacity Battery Anodes through High Temperature Radiation-Based Thermal Shock.

PubMed

Chen, Yanan; Li, Yiju; Wang, Yanbin; Fu, Kun; Danner, Valencia A; Dai, Jiaqi; Lacey, Steven D; Yao, Yonggang; Hu, Liangbing

2016-09-14

High capacity battery electrodes require nanosized components to avoid pulverization associated with volume changes during the charge-discharge process. Additionally, these nanosized electrodes need an electronically conductive matrix to facilitate electron transport. Here, for the first time, we report a rapid thermal shock process using high-temperature radiative heating to fabricate a conductive reduced graphene oxide (RGO) composite with silicon nanoparticles. Silicon (Si) particles on the order of a few micrometers are initially embedded in the RGO host and in situ transformed into 10-15 nm nanoparticles in less than a minute through radiative heating. The as-prepared composites of ultrafine Si nanoparticles embedded in a RGO matrix show great performance as a Li-ion battery (LIB) anode. The in situ nanoparticle synthesis method can also be adopted for other high capacity battery anode materials including tin (Sn) and aluminum (Al). This method for synthesizing high capacity anodes in a RGO matrix can be envisioned for roll-to-roll nanomanufacturing due to the ease and scalability of this high-temperature radiative heating process.

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

PubMed

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

2006-06-01

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

Solid-State NMR Study of the Cicada Wing.

PubMed

Gullion, John D; Gullion, Terry

2017-08-17

Wings of flying insects are part of the cuticle which forms the exoskeleton. The primary molecular components of cuticle are protein, chitin, and lipid. How these components interact with one another to form the exoskeleton is not completely understood. The difficulty in characterizing the cuticle arises because it is insoluble and noncrystalline. These properties severely limit the experimental tools that can be used for molecular characterization. Solid-state nuclear magnetic resonance experiments have been used in the past to characterize the exoskeleton of beetles and have found that chitin and protein make comparable contributions to the molecular matrix. However, little work has been done to characterize the components of the wing, which includes vein and membrane. In this work, solid-state NMR was used to characterize the wing of the 17-year cycle cicada (Magicicada cassini) that appeared in northern West Virginia during the summer of 2016. The NMR results show noticeable differences between the molecular components of the vein and membrane.

Calculations of atomic magnetic nuclear shielding constants based on the two-component normalized elimination of the small component method

NASA Astrophysics Data System (ADS)

Yoshizawa, Terutaka; Zou, Wenli; Cremer, Dieter

2017-04-01

A new method for calculating nuclear magnetic resonance shielding constants of relativistic atoms based on the two-component (2c), spin-orbit coupling including Dirac-exact NESC (Normalized Elimination of the Small Component) approach is developed where each term of the diamagnetic and paramagnetic contribution to the isotropic shielding constant σi s o is expressed in terms of analytical energy derivatives with regard to the magnetic field B and the nuclear magnetic moment 𝝁 . The picture change caused by renormalization of the wave function is correctly described. 2c-NESC/HF (Hartree-Fock) results for the σiso values of 13 atoms with a closed shell ground state reveal a deviation from 4c-DHF (Dirac-HF) values by 0.01%-0.76%. Since the 2-electron part is effectively calculated using a modified screened nuclear shielding approach, the calculation is efficient and based on a series of matrix manipulations scaling with (2M)3 (M: number of basis functions).

Implementation of an Associative Flow Rule Including Hydrostatic Stress Effects Into the High Strain Rate Deformation Analysis of Polymer Matrix Composites

NASA Technical Reports Server (NTRS)

Goldberg, Robert K.; Roberts, Gary D.; Gilat, Amos

2003-01-01

A previously developed analytical formulation has been modified in order to more accurately account for the effects of hydrostatic stresses on the nonlinear, strain rate dependent deformation of polymer matrix composites. State variable constitutive equations originally developed for metals have been modified in order to model the nonlinear, strain rate dependent deformation of polymeric materials. To account for the effects of hydrostatic stresses, which are significant in polymers, the classical J2 plasticity theory definitions of effective stress and effective inelastic strain, along with the equations used to compute the components of the inelastic strain rate tensor, are appropriately modified. To verify the revised formulation, the shear and tensile deformation of two representative polymers are computed across a wide range of strain rates. Results computed using the developed constitutive equations correlate well with experimental data. The polymer constitutive equations are implemented within a strength of materials based micromechanics method to predict the nonlinear, strain rate dependent deformation of polymer matrix composites. The composite mechanics are verified by analyzing the deformation of a representative polymer matrix composite for several fiber orientation angles across a variety of strain rates. The computed values compare well to experimentally obtained results.

Targeting the extracellular matrix of ovarian cancer using functionalized, drug loaded lyophilisomes.

PubMed

van der Steen, Sophieke C H A; Raavé, René; Langerak, Sjoerd; van Houdt, Laurens; van Duijnhoven, Sander M J; van Lith, Sanne A M; Massuger, Leon F A G; Daamen, Willeke F; Leenders, William P; van Kuppevelt, Toin H

2017-04-01

Epithelial ovarian cancer is characterized by a high mortality rate and is in need for novel therapeutic avenues to improve patient outcome. The tumor's extracellular matrix ("stroma") offers new possibilities for targeted drug-delivery. Recently we identified highly sulfated chondroitin sulfate (CS-E) as a component abundantly present in the ovarian cancer extracellular matrix, and as a novel target for anti-cancer therapy. Here, we report on the functionalization of drug-loaded lyophilisomes (albumin-based biocapsules) to specifically target the stroma of ovarian carcinomas with the potential to eliminate cancer cells. To achieve specific targeting, we conjugated single chain antibodies reactive with CS-E to lyophilisomes using a two-step approach comprising sortase-mediated ligation and bioorthogonal click chemistry. Antibody-functionalized lyophilisomes specifically targeted the ovarian cancer stroma through CS-E. In a CS-E rich micro-environment in vitro lyophilisomes induced cell death by extracellular release of doxorubicin which localized to the nucleus. Immunohistochemistry identified CS-E rich stroma in a variety of solid tumors other than ovarian cancer, including breast, lung and colon cancer indicating the potential versatility of matrix therapy and the use of highly sulfated chondroitin sulfates in cancer stroma as a micro-environmental hook for targeted drug delivery. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

EVALUATION OF SPIKING PROCEDURES FOR RECOVERY OF CRYPTOSPORIDIUM IN STREAM WATERS USING USEPA METHOD 1623

EPA Science Inventory

U.S. Environmental Protection Agency Method 1623 is widely used to monitor source waters and drinking water supplies for Cryptosporidium oocysts. Analyzing matrix spikes is an important component of Method 1623. Matrix spikes are used to determine the effect of the environmental...

Vitamins E and C - effects on matrix components in the vascular system

USDA-ARS?s Scientific Manuscript database

The connective tissue in the vascular system, consisting mainly of vascular smooth muscle cells (VSMC) and the interstitial extracellular matrix (ECM), plays important roles in the maintenance of an intact vascular wall as well as in the repair of atherosclerotic lesions during disease development. ...

Rotations with Rodrigues' Vector

ERIC Educational Resources Information Center

Pina, E.

2011-01-01

The rotational dynamics was studied from the point of view of Rodrigues' vector. This vector is defined here by its connection with other forms of parametrization of the rotation matrix. The rotation matrix was expressed in terms of this vector. The angular velocity was computed using the components of Rodrigues' vector as coordinates. It appears…

Indicating disturbance content and context for preserved areas

Treesearch

N. Zaccarelli; K.H. Riitters; I. Petrosillo; G. Zurlini

2007-01-01

An accepted goal of conservation is to build a conservation network that is resilient to environmental change. The conceptual patch-corridor-matrix model views individual conservation areas as connected components of a regional network capable of sustaining metapopulations and biodiversity, and assessment of contextual conditions in the matrix surrounding conservation...

Spectroscopic Characteristics of Dissolved Organic Matter in Afforestation Forest Soil of Miyun District, Beijing

PubMed Central

Zhao, Chen; Shi, Zong-Hai; Zhong, Jun; Liu, Jian-Guo; Li, Jun-Qing

2016-01-01

In this study, soil samples collected from different plain afforestation time (1 year, 4 years, 10 years, 15 years, and 20 years) in Miyun were characterized, including total organic carbon (TOC), total nitrogen (TN), total phosphorus (TP), available K (K+), microbial biomass carbon (MBC), and dissolved organic carbon (DOC). The DOM in the soil samples with different afforestation time was further characterized via DOC, UV-Visible spectroscopy, excitation-emission matrix (EEM) fluorescence spectroscopy, and 1H NMR spectroscopy. The results suggested that the texture of soil sample was sandy. The extracted DOM from soil consisted mainly of aliphatic chains and only a minor aromatic component. It can be included that afforestation can improve the soil quality to some extent, which can be partly reflected from the indexes like TOC, TN, TP, K+, MBC, and DOC. And the characterization of DOM implied that UV humic-like substances were the major fluorophores components in the DOM of the soil samples, which consisted of aliphatic chains and aromatic components with carbonyl, carboxyl, and hydroxyl groups. PMID:27433371

Sterilization of Lung Matrices by Supercritical Carbon Dioxide

PubMed Central

Balestrini, Jenna L.; Liu, Angela; Gard, Ashley L.; Huie, Janet; Blatt, Kelly M.S.; Schwan, Jonas; Zhao, Liping; Broekelmann, Tom J.; Mecham, Robert P.; Wilcox, Elise C.

2016-01-01

Lung engineering is a potential alternative to transplantation for patients with end-stage pulmonary failure. Two challenges critical to the successful development of an engineered lung developed from a decellularized scaffold include (i) the suppression of resident infectious bioburden in the lung matrix, and (ii) the ability to sterilize decellularized tissues while preserving the essential biological and mechanical features intact. To date, the majority of lungs are sterilized using high concentrations of peracetic acid (PAA) resulting in extracellular matrix (ECM) depletion. These mechanically altered tissues have little to no storage potential. In this study, we report a sterilizing technique using supercritical carbon dioxide (ScCO2) that can achieve a sterility assurance level 10−6 in decellularized lung matrix. The effects of ScCO2 treatment on the histological, mechanical, and biochemical properties of the sterile decellularized lung were evaluated and compared with those of freshly decellularized lung matrix and with PAA-treated acellular lung. Exposure of the decellularized tissue to ScCO2 did not significantly alter tissue architecture, ECM content or organization (glycosaminoglycans, elastin, collagen, and laminin), observations of cell engraftment, or mechanical integrity of the tissue. Furthermore, these attributes of lung matrix did not change after 6 months in sterile buffer following sterilization with ScCO2, indicating that ScCO2 produces a matrix that is stable during storage. The current study's results indicate that ScCO2 can be used to sterilize acellular lung tissue while simultaneously preserving key biological components required for the function of the scaffold for regenerative medicine purposes. PMID:26697757

Therapeutic Potential of Matrix Metalloproteinase Inhibition in Breast Cancer

PubMed Central

Raeeszadeh‐Sarmazdeh, Maryam; Radisky, Derek C.

2017-01-01

ABSTRACT Matrix metalloproteinases (MMPs) are a family of zinc endopeptidases that cleave nearly all components of the extracellular matrix as well as many other soluble and cell‐associated proteins. MMPs have been implicated in normal physiological processes, including development, and in the acquisition and progression of the malignant phenotype. Disappointing results from a series of clinical trials testing small molecule, broad spectrum MMP inhibitors as cancer therapeutics led to a re‐evaluation of how MMPs function in the tumor microenvironment, and ongoing research continues to reveal that these proteins play complex roles in cancer development and progression. It is now clear that effective targeting of MMPs for therapeutic benefit will require selective inhibition of specific MMPs. Here, we provide an overview of the MMP family and its biological regulators, the tissue inhibitors of metalloproteinases (TIMPs). We then summarize recent research from model systems that elucidate how specific MMPs drive the malignant phenotype of breast cancer cells, including acquisition of cancer stem cell features and induction of the epithelial–mesenchymal transition, and we also outline clinical studies that implicate specific MMPs in breast cancer outcomes. We conclude by discussing ongoing strategies for development of inhibitors with therapeutic potential that are capable of selectively targeting the MMPs most responsible for tumor promotion, with special consideration of the potential of biologics including antibodies and engineered proteins based on the TIMP scaffold. J. Cell. Biochem. 118: 3531–3548, 2017. © 2017 The Authors. Journal of Cellular Biochemistry Published by Wiley Periodicals, Inc. PMID:28585723

Hierarchical nonlinear behavior of hot composite structures

NASA Technical Reports Server (NTRS)

Murthy, P. L. N.; Chamis, C. C.; Singhal, S. N.

1993-01-01

Hierarchical computational procedures are described to simulate the multiple scale thermal/mechanical behavior of high temperature metal matrix composites (HT-MMC) in the following three broad areas: (1) behavior of HT-MMC's from micromechanics to laminate via METCAN (Metal Matrix Composite Analyzer), (2) tailoring of HT-MMC behavior for optimum specific performance via MMLT (Metal Matrix Laminate Tailoring), and (3) HT-MMC structural response for hot structural components via HITCAN (High Temperature Composite Analyzer). Representative results from each area are presented to illustrate the effectiveness of computational simulation procedures and accompanying computer codes. The sample case results show that METCAN can be used to simulate material behavior such as the entire creep span; MMLT can be used to concurrently tailor the fabrication process and the interphase layer for optimum performance such as minimum residual stresses; and HITCAN can be used to predict the structural behavior such as the deformed shape due to component fabrication. These codes constitute virtual portable desk-top test laboratories for characterizing HT-MMC laminates, tailoring the fabrication process, and qualifying structural components made from them.

Development of methods to monitor ionization modification from dosing vehicles and phospholipids in study samples.

PubMed

Chang, Min; Li, Yongchao; Angeles, Reginald; Khan, Samina; Chen, Lian; Kaplan, Julia; Yang, Liyu

2011-08-01

Two approaches to monitor the matrix effect on ionization in study samples were described. One approach is the addition of multiple reaction monitoring transitions to the bioanalytical methods to monitor the presence of known ionization modification-causing components of the matrix, for example, m/z 184→125 (or m/z 184→184) and m/z 133→89 may be used for phospholipids and polyethylene oxide containing surfactants, respectively. This approach requires no additional equipment and can be readily adapted for most method. The approach detects only the intended interfering compounds and provides little quantitative indication if the matrix effect is within the tolerable range (±15%). The other approach requires the addition of an infusion pump and identifies an appropriate surrogate of the analyte to be infused for the determination of modification on the ionization of the analyte. The second approach detects interferences in the sample regardless of the sources (i.e., dosing vehicle components, co-administrated drugs, their metabolites, phospholipids, plasticizers and endogenous components introduced due to disease stage).

Finger crease pattern recognition using Legendre moments and principal component analysis

NASA Astrophysics Data System (ADS)

Luo, Rongfang; Lin, Tusheng

2007-03-01

The finger joint lines defined as finger creases and its distribution can identify a person. In this paper, we propose a new finger crease pattern recognition method based on Legendre moments and principal component analysis (PCA). After obtaining the region of interest (ROI) for each finger image in the pre-processing stage, Legendre moments under Radon transform are applied to construct a moment feature matrix from the ROI, which greatly decreases the dimensionality of ROI and can represent principal components of the finger creases quite well. Then, an approach to finger crease pattern recognition is designed based on Karhunen-Loeve (K-L) transform. The method applies PCA to a moment feature matrix rather than the original image matrix to achieve the feature vector. The proposed method has been tested on a database of 824 images from 103 individuals using the nearest neighbor classifier. The accuracy up to 98.584% has been obtained when using 4 samples per class for training. The experimental results demonstrate that our proposed approach is feasible and effective in biometrics.

Gram scale synthesis of Fe/Fe xO y core–shell nanoparticles and their incorporation into matrix-free superparamagnetic nanocomposites

DOE PAGES

Watt, John Daniel; Bleier, Grant C.; Romero, Zachary William; ...

2018-05-15

In this paper, significant reductions recently seen in the size of wide-bandgap power electronics have not been accompanied by a relative decrease in the size of the corresponding magnetic components. To achieve this, a new generation of materials with high magnetic saturation and permeability are needed. Here, we develop gram-scale syntheses of superparamagnetic Fe/Fe xO y core–shell nanoparticles and incorporate them as the magnetic component in a strongly magnetic nanocomposite. Nanocomposites are typically formed by the organization of nanoparticles within a polymeric matrix. However, this approach can lead to high organic fractions and phase separation; reducing the performance of themore » resulting material. Here, we form aminated nanoparticles that are then cross-linked using epoxy chemistry. The result is a magnetic nanoparticle component that is covalently linked and well separated. By using this ‘matrix-free’ approach, we can substantially increase the magnetic nanoparticle fraction, while still maintaining good separation, leading to a superparamagnetic nanocomposite with strong magnetic properties.« less

Gram scale synthesis of Fe/Fe xO y core–shell nanoparticles and their incorporation into matrix-free superparamagnetic nanocomposites

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

Watt, John Daniel; Bleier, Grant C.; Romero, Zachary William

In this paper, significant reductions recently seen in the size of wide-bandgap power electronics have not been accompanied by a relative decrease in the size of the corresponding magnetic components. To achieve this, a new generation of materials with high magnetic saturation and permeability are needed. Here, we develop gram-scale syntheses of superparamagnetic Fe/Fe xO y core–shell nanoparticles and incorporate them as the magnetic component in a strongly magnetic nanocomposite. Nanocomposites are typically formed by the organization of nanoparticles within a polymeric matrix. However, this approach can lead to high organic fractions and phase separation; reducing the performance of themore » resulting material. Here, we form aminated nanoparticles that are then cross-linked using epoxy chemistry. The result is a magnetic nanoparticle component that is covalently linked and well separated. By using this ‘matrix-free’ approach, we can substantially increase the magnetic nanoparticle fraction, while still maintaining good separation, leading to a superparamagnetic nanocomposite with strong magnetic properties.« less

Niche Extracellular Matrix Components and Their Influence on HSC.

PubMed

Domingues, Mélanie J; Cao, Huimin; Heazlewood, Shen Y; Cao, Benjamin; Nilsson, Susan K

2017-08-01

Maintenance of hematopoietic stem cells (HSC) takes place in a highly specialized microenvironment within the bone marrow. Technological improvements, especially in the field of in vivo imaging, have helped unravel the complexity of the niche microenvironment and have completely changed the classical concept from what was previously believed to be a static supportive platform, to a dynamic microenvironment tightly regulating HSC homeostasis through the complex interplay between diverse cell types, secreted factors, extracellular matrix molecules, and the expression of different transmembrane receptors. To add to the complexity, non-protein based metabolites have also been recognized as a component of the bone marrow niche. The objective of this review is to discuss the current understanding on how the different extracellular matrix components of the niche regulate HSC fate, both during embryonic development and in adulthood. Special attention will be provided to the description of non-protein metabolites, such as lipids and metal ions, which contribute to the regulation of HSC behavior. J. Cell. Biochem. 118: 1984-1993, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Quiet-Time Spectra and Abundances of Energetic Particles During the 1996 Solar Minimum

NASA Technical Reports Server (NTRS)

Reames, Donald V.

1999-01-01

We report the energy spectra and abundances of ions with atomic number, Z, in the interval Z is greater than or equal to 2 and Z is less than or equal to 36 and energies approximately 3-20 MeV/amu for solar and interplanetary quiet periods between 1994 November and 1998 April as measured by the large-geometry Low Energy Matrix Telescope (LEMT) telescope on the Wind spacecraft near Earth. The energy spectra show the presence of galactic (GCR) and "anomalous" cosmic ray (ACR) components, depending on the element. ACR components are reported for Mg and Si for the first time at 1 AU and the previous observation of S and Ar is confirmed. However, only GCR components are clearly apparent for the elements Ca, Ti, Cr, Fe, as well as for C. New limits are placed on a possible ACR contribution for other elements, including Kr.

Remote activation of a microactuator using a photo-responsive nanoparticle-polymer composite

NASA Astrophysics Data System (ADS)

Zeberoff, Anthony

Stimulus response materials are a class of novel materials that are currently being explored in various technologies, including biomedical devices and components, food packaging, fabrics, energy harvesting and conversion, and other elementary components such as sensors and actuators. Hybrid organic-inorganic materials such as nanoparticle-polymer composites are attractive candidates as their properties can be significantly tuned for particular applications where selectivity and localized responses are critical factors. In this work we developed and optimized a photo-responsive microactuator that can operate selectively to a specific wavelength of light. The photo-responsive microactuator is comprised of monodispersed microspheres that contain gold nanoparticles. Upon irradiation, these microspheres transduce optical energy to thermal energy, driving a localized phase change in the matrix in which they are embedded. Our remotely powered microactuator can be further realized in applications where decoupling the physical connection of the energy/control source from the actuating component is necessary.

New dynamic variables for rotating spacecraft

NASA Technical Reports Server (NTRS)

Markley, F. Landis

1993-01-01

This paper introduces two new seven-parameter representations for spacecraft attitude dynamics modeling. The seven parameters are the three components of the total system angular momentum in the spacecraft body frame; the three components of the angular momentum in the inertial reference frame; and an angle variable. These obey a single constraint as do parameterizations that include a quaternion; in this case the constraint is the equality of the sum of the squares of the angular momentum components in the two frames. The two representations are nonsingular if the system angular momentum is non-zero and obeys certain orientation constraints. The new parameterizations of the attitude matrix, the equations of motion, and the relation of the solution of these equations to Euler angles for torque-free motion are developed and analyzed. The superiority of the new parameterizations for numerical integration is shown in a specific example.

Safety biocompatibility of gelatin hemostatic matrix (Floseal and Surgiflo) in neurosurgical procedures.

PubMed

Gazzeri, Roberto; Galarza, Marcelo; Alfier, Alex

2012-12-01

Adequate hemostasis in cranial and spinal surgery is of paramount importance in a neurosurgeon's daily practice. Generalized ooze bleeding from the surgical wall cavities, coming from the dura mater or nervous tissue may be troublesome and may limit visualization in minimally invasive neurosurgery. Hemostatic matrix is a mixture of a flowable gelatin matrix (bovine or porcine) and a thrombin component mixed together. A total of 318 patients undergoing cranial, craniospinal, and spinal procedure with the use of gelatin hemostatic matrix (Floseal and Surgiflo) were enrolled in this clinical study. We compared the different hemostatic techniques using the gelatin hemostatic matrix, and investigated indications, time to bleeding control, and its efficacy and safety in neurosurgery.

Characterization of matrix effects in developing rugged high-throughput LC-MS/MS methods for bioanalysis.

PubMed

Li, Fumin; Wang, Jun; Jenkins, Rand

2016-05-01

There is an ever-increasing demand for high-throughput LC-MS/MS bioanalytical assays to support drug discovery and development. Matrix effects of sofosbuvir (protonated) and paclitaxel (sodiated) were thoroughly evaluated using high-throughput chromatography (defined as having a run time ≤1 min) under 14 elution conditions with extracts from protein precipitation, liquid-liquid extraction and solid-phase extraction. A slight separation, in terms of retention time, between underlying matrix components and sofosbuvir/paclitaxel can greatly alleviate matrix effects. High-throughput chromatography, with proper optimization, can provide rapid and effective chromatographic separation under 1 min to alleviate matrix effects and enhance assay ruggedness for regulated bioanalysis.

Visualization of predentine matrix components and endocytic structures in rat incisor odontoblasts with tannic acid.

PubMed

Goldberg, M; Septier, D

1989-12-01

Rat incisor odontoblasts and predentine fixed with tannic acid-glutaraldehyde-osmium tetroxide (Tago) were compared with those obtained by prior incubation in tannic acid-Ringer before conventional fixation with glutaraldehyde-osmium-tetroxide (Tari) The Tago method allowed visualization of complex glycoconjugates along the plasma membrane, in the pericellular spaces and in the intercellular predentine matrix. The non-collagenous proteins, proteoglycans and lipids were seen as granules and thin filaments located between the collagen fibers and at their surface. The collagen fibers themselves were also stained. The Tari method which was used to visualize exocytosis, mainly revealed endocytosis in the form of large intracellular vacuoles containing tannic acid and stained proteoglycans. It is suggested that tannic acid-Ringer incubation prior to fixation increases the endocytosis of the matrix components, which acculumates in these large vesicles.

Assessment of hyaline cartilage matrix composition using near infrared spectroscopy.

PubMed

Palukuru, Uday P; McGoverin, Cushla M; Pleshko, Nancy

2014-09-01

Changes in the composition of the extracellular matrix (ECM) are characteristic of injury or disease in cartilage tissue. Various imaging modalities and biochemical techniques have been used to assess the changes in cartilage tissue but lack adequate sensitivity, or in the case of biochemical techniques, result in destruction of the sample. Fourier transform near infrared (FT-NIR) spectroscopy has shown promise for the study of cartilage composition. In the current study NIR spectroscopy was used to identify the contributions of individual components of cartilage in the NIR spectra by assessment of the major cartilage components, collagen and chondroitin sulfate, in pure component mixtures. The NIR spectra were obtained using homogenous pellets made by dilution with potassium bromide. A partial least squares (PLS) model was calculated to predict composition in bovine cartilage samples. Characteristic absorbance peaks between 4000 and 5000 cm(-1) could be attributed to components of cartilage, i.e. collagen and chondroitin sulfate. Prediction of the amount of collagen and chondroitin sulfate in tissues was possible within 8% (w/dw) of values obtained by gold standard biochemical assessment. These results support the use of NIR spectroscopy for in vitro and in vivo applications to assess matrix composition of cartilage tissues, especially when tissue destruction should be avoided. Copyright © 2014. Published by Elsevier B.V.

Bioaccessible nutrients and bioactive components from fortified products prepared using finger millet (Eleusine coracana).

PubMed

Oghbaei, Morteza; Prakash, Jamuna

2012-08-30

Finger millet (Eleusine coracana), a staple food in semi-arid parts of the world, is a rich source of nutrients and bioactive components comparable to rice and wheat but with higher fibre content. Unprocessed and processed finger millet (whole flour (WFM), sieved flour (SFM), wafers and vermicelli with altered matrices (added Fe or Zn or reduced fibre)) were analysed for chemical composition, bioaccessible Fe, Zn and Ca, in vitro digestible starch (IVSD) and protein (IVPD) and bioactive components (polyphenols and flavonoids). WFM and SFM flours differed significantly in their composition. Sieving decreased the content of both nutrients and antinutrients in WFM but increased their digestibility/bioaccessibility. WFM products with Zn and Fe showed highest IVPD, whereas SFM products with Fe showed highest IVSD. Products with externally added Fe and Zn showed maximum bioaccessibility of Fe and Zn respectively. WFM had the highest levels of total polyphenols and flavonoids, 4.18 and 15.85 g kg⁻¹ respectively; however, bioaccessibility was highest in SFM vermicelli. The availability of nutrients and bioactive components was influenced by both processing methods and compositional alterations of the food matrix in finger millet products, and bioaccessibility of all constituents was higher in vermicelli (wet matrix) than in wafers (dry matrix). Copyright © 2012 Society of Chemical Industry.

Computational model for the analysis of cartilage and cartilage tissue constructs

PubMed Central

Smith, David W.; Gardiner, Bruce S.; Davidson, John B.; Grodzinsky, Alan J.

2013-01-01

We propose a new non-linear poroelastic model that is suited to the analysis of soft tissues. In this paper the model is tailored to the analysis of cartilage and the engineering design of cartilage constructs. The proposed continuum formulation of the governing equations enables the strain of the individual material components within the extracellular matrix (ECM) to be followed over time, as the individual material components are synthesized, assembled and incorporated within the ECM or lost through passive transport or degradation. The material component analysis developed here naturally captures the effect of time-dependent changes of ECM composition on the deformation and internal stress states of the ECM. For example, it is shown that increased synthesis of aggrecan by chondrocytes embedded within a decellularized cartilage matrix initially devoid of aggrecan results in osmotic expansion of the newly synthesized proteoglycan matrix and tension within the structural collagen network. Specifically, we predict that the collagen network experiences a tensile strain, with a maximum of ~2% at the fixed base of the cartilage. The analysis of an example problem demonstrates the temporal and spatial evolution of the stresses and strains in each component of a self-equilibrating composite tissue construct, and the role played by the flux of water through the tissue. PMID:23784936

Loss of laminin alpha 1 results in multiple structural defects and divergent effects on adhesion during vertebrate optic cup morphogenesis

PubMed Central

Bryan, Chase D.; Chien, Chi-Bin; Kwan, Kristen M.

2016-01-01

The vertebrate eye forms via a complex set of morphogenetic events. The optic vesicle evaginates and undergoes transformative shape changes to form the optic cup, in which neural retina and retinal pigmented epithelium enwrap the lens. It has long been known that a complex, glycoprotein-rich extracellular matrix layer surrounds the developing optic cup throughout the process, yet the functions of the matrix and its specific molecular components have remained unclear. Previous work established a role for laminin extracellular matrix in particular steps of eye development, including optic vesicle evagination, lens differentiation, and retinal ganglion cell polarization, yet it is unknown what role laminin might play in the early process of optic cup formation subsequent to the initial step of optic vesicle evagination. Here, we use the zebrafish lama1 mutant (lama1UW1) to determine the function of laminin during optic cup morphogenesis. Using live imaging, we find, surprisingly, that loss of laminin leads to divergent effects on focal adhesion assembly in a spatiotemporally-specific manner, and that laminin is required for multiple steps of optic cup morphogenesis, including optic stalk constriction, invagination, and formation of a spherical lens. Laminin is not required for single cell behaviors and changes in cell shape. Rather, in lama1UW1 mutants, loss of epithelial polarity and altered adhesion lead to defective tissue architecture and formation of a disorganized retina. These results demonstrate that the laminin extracellular matrix plays multiple critical roles regulating adhesion and polarity to establish and maintain tissue structure during optic cup morphogenesis. PMID:27339294

Components of Torpedo electric organ and muscle that cause aggregation of acetylcholine receptors on cultured muscle cells

PubMed Central

1984-01-01

The synaptic portion of a muscle fiber's basal lamina sheath has molecules tightly bound to it that cause aggregation of acetylcholine receptors (AChRs) on regenerating myofibers. Since basal lamina and other extracellular matrix constituents are insoluble in isotonic saline and detergent solutions, insoluble detergent-extracted fractions of tissues receiving cholinergic input may provide an enriched source of the AChR-aggregating molecules for detailed characterization. Here we demonstrate that such an insoluble fraction from Torpedo electric organ, a tissue with a high concentration of cholinergic synapses, causes AChRs on cultured chick muscle cells to aggregate. We have partially characterized the insoluble fraction, examined the response of muscle cells to it, and devised ways of extracting the active components with a view toward purifying them and learning whether they are similar to those in the basal lamina at the neuromuscular junction. The insoluble fraction from the electric organ was rich in extracellular matrix constituents; it contained structures resembling basal lamina sheaths and had a high density of collagen fibrils. It caused a 3- to 20-fold increase in the number of AChR clusters on cultured myotubes without significantly affecting the number or size of the myotubes. The increase was first seen 2-4 h after the fraction was added to cultures and it was maximal by 24 h. The AChR-aggregating effect was dose dependent and was due, at least in part, to lateral migration of AChRs present in the muscle cell plasma membrane at the time the fraction was applied. Activity was destroyed by heat and by trypsin. The active component(s) was extracted from the insoluble fraction with high ionic strength or pH 5.5 buffers. The extracts increased the number of AChR clusters on cultured myotubes without affecting the number or degradation rate of surface AChRs. Antiserum against the solubilized material blocked its effect on AChR distribution and bound to the active component. Insoluble fractions of Torpedo muscle and liver did not cause AChR aggregation on cultured myotubes. However a low level of activity was detected in pH 5.5 extracts from the muscle fraction. The active component(s) in the muscle extract was immunoprecipitated by the antiserum against the material extracted from the electric organ insoluble fraction. This antiserum also bound to extracellular matrix in frog muscles, including the myofiber basal lamina sheath. Thus the insoluble fraction of Torpedo electric organ is rich in AChR-aggregating molecules that are also found in muscle and has components antigenically similar to those in myofiber basal lamina. PMID:6746740

Postconcussive Symptoms in OEF-OIF Veterans: Factor Structure and Impact of Posttraumatic Stress

DTIC Science & Technology

2009-06-03

correlations between NSI full items are presented in Appendix A. Visual inspection of the correlation matrix, the Kaiser - Meyer - Olkin coefficient of .92, and...Spearman rho correlations between NSI residuals are pre- sented in Appendix B. Again, visual inspection of the correla- tion matrix, the Kaiser - Meyer ... Olkin coefficient of .83, and Bartlett’s test of sphericity (x2 5 1,936.0, p , .01) suggested that the matrix could be factored. Principal-components

Molecular Orientation in Two Component Vapor-Deposited Glasses: Effect of Substrate Temperature and Molecular Shape

NASA Astrophysics Data System (ADS)

Powell, Charles; Jiang, Jing; Walters, Diane; Ediger, Mark

Vapor-deposited glasses are widely investigated for use in organic electronics including the emitting layers of OLED devices. These materials, while macroscopically homogenous, have anisotropic packing and molecular orientation. By controlling this orientation, outcoupling efficiency can be increased by aligning the transition dipole moment of the light-emitting molecules parallel to the substrate. Light-emitting molecules are typically dispersed in a host matrix, as such, it is imperative to understand molecular orientation in two-component systems. In this study we examine two-component vapor-deposited films and the orientations of the constituent molecules using spectroscopic ellipsometry, UV-vis and IR spectroscopy. The role of temperature, composition and molecular shape as it effects molecular orientation is examined for mixtures of DSA-Ph in Alq3 and in TPD. Deposition temperature relative to the glass transition temperature of the two-component mixture is the primary controlling factor for molecular orientation. In mixtures of DSA-Ph in Alq3, the linear DSA-Ph has a horizontal orientation at low temperatures and slight vertical orientation maximized at 0.96Tg,mixture, analogous to one-component films.

Efficient system modeling for a small animal PET scanner with tapered DOI detectors.

PubMed

Zhang, Mengxi; Zhou, Jian; Yang, Yongfeng; Rodríguez-Villafuerte, Mercedes; Qi, Jinyi

2016-01-21

A prototype small animal positron emission tomography (PET) scanner for mouse brain imaging has been developed at UC Davis. The new scanner uses tapered detector arrays with depth of interaction (DOI) measurement. In this paper, we present an efficient system model for the tapered PET scanner using matrix factorization and a virtual scanner geometry. The factored system matrix mainly consists of two components: a sinogram blurring matrix and a geometrical matrix. The geometric matrix is based on a virtual scanner geometry. The sinogram blurring matrix is estimated by matrix factorization. We investigate the performance of different virtual scanner geometries. Both simulation study and real data experiments are performed in the fully 3D mode to study the image quality under different system models. The results indicate that the proposed matrix factorization can maintain image quality while substantially reduce the image reconstruction time and system matrix storage cost. The proposed method can be also applied to other PET scanners with DOI measurement.

ASTM and VAMAS activities in titanium matrix composites test methods development

NASA Technical Reports Server (NTRS)

Johnson, W. S.; Harmon, D. M.; Bartolotta, P. A.; Russ, S. M.

1994-01-01

Titanium matrix composites (TMC's) are being considered for a number of aerospace applications ranging from high performance engine components to airframe structures in areas that require high stiffness to weight ratios at temperatures up to 400 C. TMC's exhibit unique mechanical behavior due to fiber-matrix interface failures, matrix cracks bridged by fibers, thermo-viscoplastic behavior of the matrix at elevated temperatures, and the development of significant thermal residual stresses in the composite due to fabrication. Standard testing methodology must be developed to reflect the uniqueness of this type of material systems. The purpose of this paper is to review the current activities in ASTM and Versailles Project on Advanced Materials and Standards (VAMAS) that are directed toward the development of standard test methodology for titanium matrix composites.

The controversial nuclear matrix: a balanced point of view.

PubMed

Martelli, A M; Falcieri, E; Zweyer, M; Bortul, R; Tabellini, G; Cappellini, A; Cocco, L; Manzoli, L

2002-10-01

The nuclear matrix is defined as the residual framework after the removal of the nuclear envelope, chromatin, and soluble components by sequential extractions. According to several investigators the nuclear matrix provides the structural basis for intranuclear order. However, the existence itself and the nature of this structure is still uncertain. Although the techniques used for the visualization of the nuclear matrix have improved over the years, it is still unclear to what extent the isolated nuclear matrix corresponds to an in vivo existing structure. Therefore, considerable skepticism continues to surround the nuclear matrix fraction as an accurate representation of the situation in living cells. Here, we summarize the experimental evidence in favor of, or against, the presence of a diffuse nucleoskeleton as a facilitating organizational nonchromatin structure of the nucleus.

Fast Component Pursuit for Large-Scale Inverse Covariance Estimation.

PubMed

Han, Lei; Zhang, Yu; Zhang, Tong

2016-08-01

The maximum likelihood estimation (MLE) for the Gaussian graphical model, which is also known as the inverse covariance estimation problem, has gained increasing interest recently. Most existing works assume that inverse covariance estimators contain sparse structure and then construct models with the ℓ 1 regularization. In this paper, different from existing works, we study the inverse covariance estimation problem from another perspective by efficiently modeling the low-rank structure in the inverse covariance, which is assumed to be a combination of a low-rank part and a diagonal matrix. One motivation for this assumption is that the low-rank structure is common in many applications including the climate and financial analysis, and another one is that such assumption can reduce the computational complexity when computing its inverse. Specifically, we propose an efficient COmponent Pursuit (COP) method to obtain the low-rank part, where each component can be sparse. For optimization, the COP method greedily learns a rank-one component in each iteration by maximizing the log-likelihood. Moreover, the COP algorithm enjoys several appealing properties including the existence of an efficient solution in each iteration and the theoretical guarantee on the convergence of this greedy approach. Experiments on large-scale synthetic and real-world datasets including thousands of millions variables show that the COP method is faster than the state-of-the-art techniques for the inverse covariance estimation problem when achieving comparable log-likelihood on test data.

Applicability of the "Emotiv EEG Neuroheadset" as a user-friendly input interface.

PubMed

Boutani, Hidenori; Ohsuga, Mieko

2013-01-01

We aimed to develop an input interface by using the P3 component of visual event-related potentials (ERPs). When using electroencephalography (EEG) in daily applications, coping with ocular-motor artifacts and ensuring that the equipment is user-friendly are both important. To address the first issue, we applied a previously proposed method that applies an unmixing matrix to acquire independent components (ICs) obtained from another dataset. For the second issue, we introduced a 14-channel EEG commercial headset called the "Emotiv EEG Neuroheadset". An advantage of the Emotiv headset is that users can put it on by themselves within 1 min without any specific skills. However, only a few studies have investigated whether EEG and ERP signals are accurately measured by Emotiv. Additionally, no electrodes of the Emotiv headset are located over the centroparietal area of the head where P3 components are reported to show large amplitudes. Therefore, we first demonstrated that the P3 components obtained by the headset and by commercial plate electrodes and a multipurpose bioelectric amplifier during an oddball task were comparable. Next, we confirmed that eye-blink and ocular movement components could be decomposed by independent component analysis (ICA) using the 14-channel signals measured by the headset. We also demonstrated that artifacts could be removed with an unmixing matrix, as long as the matrix was obtained from the same person, even if they were measured on different days. Finally, we confirmed that the fluctuation of the sampling frequency of the Emotiv headset was not a major problem.

Assessment of the State-of-the-Art in the Design and Manufacturing of Large Composite Structure

NASA Technical Reports Server (NTRS)

Harris, C. E.

2001-01-01

This viewgraph presentation gives an assessment of the state-of-the-art in the design and manufacturing of large component structures, including details on the use of continuous fiber reinforced polymer matrix composites (CFRP) in commercial and military aircraft and in space launch vehicles. Project risk mitigation plans must include a building-block test approach to structural design development, manufacturing process scale-up development tests, and pre-flight ground tests to verify structural integrity. The potential benefits of composite structures justifies NASA's investment in developing the technology. Advanced composite structures technology is enabling to virtually every Aero-Space Technology Enterprise Goal.

Analysis of the Aspergillus fumigatus Biofilm Extracellular Matrix by Solid-State Nuclear Magnetic Resonance Spectroscopy.

PubMed

Reichhardt, Courtney; Ferreira, Jose A G; Joubert, Lydia-Marie; Clemons, Karl V; Stevens, David A; Cegelski, Lynette

2015-11-01

Aspergillus fumigatus is commonly responsible for lethal fungal infections among immunosuppressed individuals. A. fumigatus forms biofilm communities that are of increasing biomedical interest due to the association of biofilms with chronic infections and their increased resistance to antifungal agents and host immune factors. Understanding the composition of microbial biofilms and the extracellular matrix is important to understanding function and, ultimately, to developing strategies to inhibit biofilm formation. We implemented a solid-state nuclear magnetic resonance (NMR) approach to define compositional parameters of the A. fumigatus extracellular matrix (ECM) when biofilms are formed in RPMI 1640 nutrient medium. Whole biofilm and isolated matrix networks were also characterized by electron microscopy, and matrix proteins were identified through protein gel analysis. The (13)C NMR results defined and quantified the carbon contributions in the insoluble ECM, including carbonyls, aromatic carbons, polysaccharide carbons (anomeric and nonanomerics), aliphatics, etc. Additional (15)N and (31)P NMR spectra permitted more specific annotation of the carbon pools according to C-N and C-P couplings. Together these data show that the A. fumigatus ECM produced under these growth conditions contains approximately 40% protein, 43% polysaccharide, 3% aromatic-containing components, and up to 14% lipid. These fundamental chemical parameters are needed to consider the relationships between composition and function in the A. fumigatus ECM and will enable future comparisons with other organisms and with A. fumigatus grown under alternate conditions. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

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

PubMed

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

1998-01-15

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

Extracellular Matrix Reorganization During Wound Healing and Its Impact on Abnormal Scarring

PubMed Central

Xue, Meilang; Jackson, Christopher J.

2015-01-01

Significance: When a cutaneous injury occurs, the wound heals via a dynamic series of physiological events, including coagulation, granulation tissue formation, re-epithelialization, and extracellular matrix (ECM) remodeling. The final stage can take many months, yet the new ECM forms a scar that never achieves the flexibility or strength of the original tissue. In certain circumstances, the normal scar is replaced by pathological fibrotic tissue, which results in hypertrophic or keloid scars. These scars cause significant morbidity through physical dysfunction and psychological stress. Recent Advances and Critical Issues: The cutaneous ECM comprises a complex assortment of proteins that was traditionally thought to simply provide structural integrity and scaffolding characteristics. However, recent findings show that the ECM has multiple functions, including, storage and delivery of growth factors and cytokines, tissue repair and various physiological functions. Abnormal ECM reconstruction during wound healing contributes to the formation of hypertrophic and keloid scars. Whereas adult wounds heal with scarring, the developing foetus has the ability to heal wounds in a scarless fashion by regenerating skin and restoring the normal ECM architecture, strength, and function. Recent studies show that the lack of inflammation in fetal wounds contributes to this perfect healing. Future Directions: Better understanding of the exact roles of ECM components in scarring will allow us to produce therapeutic agents to prevent hypertrophic and keloid scars. This review will focus on the components of the ECM and their role in both physiological and pathological (hypertrophic and keloid) cutaneous scar formation. PMID:25785236

The Strategy Selection Matrix--A Guide for Individualizing Instruction.

ERIC Educational Resources Information Center

Bell, Steven

The Strategy Selection Matrix (SSM) is offered as a means for matching teaching technique to the individual special needs student. Three steps in the SSM are described: development of an intra-individual learning style profile based on 14 learning components; review of the individualizing teaching strategies (such as tutoring, continuous progress…

HYDROPHOBIC ZEOLITE-SILICONE RUBBER MIXED MATRIX MEMBRANES FOR ETHANOL-WATER SEPARATION: EFFECT OF ZEOLITE AND SILICONE COMPONENT SELECTION ON PERVAPORATION PERFORMANCE

EPA Science Inventory

High-silica ZSM 5 zeolites were incorporated into poly(dimethyl siloxane) (PDMS) polymers to form mixed matrix membranes for ethanol removal from water via pervaporation. Membrane formulation and preparation parameters were varied to determine the effect on pervaporation perform...

Calculating the permeability coefficients of mixed matrix membranes of polydimethylsiloxane and silicalite crystals to various ethanol-water solutions using molecular simulations.

EPA Science Inventory

The permeability coefficients of mixed matrix membranes of polydimethylsiloxane (PDMS) and silicalite crystal are taken as the sum of the permeability coefficients of membrane components each weighted by their associated mass fraction. The permeability coefficient of a membrane c...

A Familiar Pattern? Semantic Memory Contributes to the Enhancement of Visuo-Spatial Memories

ERIC Educational Resources Information Center

Riby, Leigh M.; Orme, Elizabeth

2013-01-01

In this study we quantify for the first time electrophysiological components associated with incorporating long-term semantic knowledge with visuo-spatial information using two variants of a traditional matrix patterns task. Results indicated that the matrix task with greater semantic content was associated with enhanced accuracy and RTs in a…

Some observations on the fracture of austempered ductile iron

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

Fan, Z.K.; Smallman, R.E.

1994-07-15

There is extensive work on the fracture of steel with ferrite or/and austenite structure, but little on crack propagation in austempered ductile iron (ADI) whose microstructure also comprises austenite and ferrite (in the form of bainitic ferrite) but with graphite nodules in the matrix. Because of its good combination of wear resistance and toughness, and its low density and low cost (compared with forge steel), ADI has been widely used for various kinds of engineering components, such as gears, crankshafts, vehicle components, sprockets, cutting and digging tools etc. The matrix of ADI can withstand a certain amount of deformation beforemore » fracture during tensile or impact testing; for example, the elongation of ADI (grade 1050/700/7 to ASTM Standard) can reach 7--10% during tensile testing. However, the graphite nodules in the matrix cannot deform and hence are barriers to matrix deformation and give rise to crack initiation. In addition, carbides may precipitate in the bainitic ferrite laths or at the ferrite/austenite interfaces and these may also influence the fracture of ADI and produce characteristic features.« less

Carbon matrix based magnetic nanocomposites for potential biomedical applications.

PubMed

Izydorzak-Wozniak, M; Leonowicz, M

2014-03-01

It was found that by varying the pyrolysis temperature of the polymeric precursor, carbon matrix magnetic nanocomposites with different constitution and fractions of magnetic component were made. X-ray diffraction, transmission electron microscopy and Raman spectroscopy revealed the presence of nanocrystallites (NCs) of Co, Fe3C and Ni embedded in porous, partially-graphitized carbon matrix. Vibrating sample magnetometer measurements enabled to determine the correlation between NCs size distribution and magnetic properties. The magnetic studies confirmed that the coercivity, saturation and remanent magnetizations, as well as fraction of the magnetic component depend on the pyrolysis temperature. The Co#C and Fe3C#C composites exhibited ferromagnetic behavior with a remanent to saturation magnetization (M(R)/M(S)) ratio ranging from 0.25 to 0.3, whereas in the Ni containing samples a relatively small M(R)/M(S) ratio point to significant contribution of superparamagnetic interactions. As the carbon matrix magnetic nanocomposites are proposed for biomedical application the basic cytotoxicity test were performed to evaluate a potential toxic effect of the materials on MG-63 cells line.

Matrix Gelatinases in Atherosclerosis and Diabetic Nephropathy: Progress and Challenges.

PubMed

Dimas, Grigorios G; Didangelos, Triantafyllos P; Grekas, Dimitrios M

2017-01-01

Matrix metalloproteinases (MMPs) are zinc-dependent proteases that degrade components of the extracellular matrix (ECM). In glomerular disease, MMPs are major regulators of ECM degradation as well as structural and functional integrity in the glomerulus. In altered matrix composition diseases, glomerular damage is due to increased degradation of kidney and vessel basement membranes (BMs) by MMPs. MMP -2 and -9 are both considered as the main enzymes that degrade collagen type-IV (coll-IV), which represents the key collagenous component of ECM and constitutes the architectural structure of vessels and glomerular BM. There is growing evidence implicating MMPs in atherosclerosis as well as in cardiovascular disease (CVD) and chronic kidney disease (CKD). Specific endogenous tissue inhibitors of MMPs (TIMPs) are also implicated in CKD, CVD and diabetic nephropathy (DN). The present review discusses the role of MMPs -2 and -9 in DN, as a leading cause of endstage renal disease and as a model of the link between progressive glomerulosclerosis and MMP expression. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Extracellular DNA and lipoteichoic acids interact with exopolysaccharides in the extracellular matrix of Streptococcus mutans biofilms.

PubMed

Castillo Pedraza, Midian C; Novais, Tatiana F; Faustoferri, Roberta C; Quivey, Robert G; Terekhov, Anton; Hamaker, Bruce R; Klein, Marlise I

2017-10-01

Streptococcus mutans-derived exopolysaccharides are virulence determinants in the matrix of biofilms that cause caries. Extracellular DNA (eDNA) and lipoteichoic acid (LTA) are found in cariogenic biofilms, but their functions are unclear. Therefore, strains of S. mutans carrying single deletions that would modulate matrix components were used: eDNA - ∆lytS and ∆lytT; LTA - ∆dltA and ∆dltD; and insoluble exopolysaccharide - ΔgtfB. Single-species (parental strain S. mutans UA159 or individual mutant strains) and mixed-species (UA159 or mutant strain, Actinomyces naeslundii and Streptococcus gordonii) biofilms were evaluated. Distinct amounts of matrix components were detected, depending on the inactivated gene. eDNA was found to be cooperative with exopolysaccharide in early phases, while LTA played a larger role in the later phases of biofilm development. The architecture of mutant strains biofilms was distinct (vs UA159), demonstrating that eDNA and LTA influence exopolysaccharide distribution and microcolony organization. Thus, eDNA and LTA may shape exopolysaccharide structure, affecting strategies for controlling pathogenic biofilms.

Hyperunstable matrix proteins in the byssus of Mytilus galloprovincialis.

PubMed

Sagert, Jason; Waite, J Herbert

2009-07-01

The marine mussel Mytilus galloprovincialis is tethered to rocks in the intertidal zone by a holdfast known as the byssus. Functioning as a shock absorber, the byssus is composed of threads, the primary molecular components of which are collagen-containing proteins (preCOLs) that largely dictate the higher order self-assembly and mechanical properties of byssal threads. The threads contain additional matrix components that separate and perhaps lubricate the collagenous microfibrils during deformation in tension. In this study, the thread matrix proteins (TMPs), a glycine-, tyrosine- and asparagine-rich protein family, were shown to possess unique repeated sequence motifs, significant transcriptional heterogeneity and were distributed throughout the byssal thread. Deamidation was shown to occur at a significant rate in a recombinant TMP and in the byssal thread as a function of time. Furthermore, charge heterogeneity presumably due to deamidation was observed in TMPs extracted from threads. The TMPs were localized to the preCOL-containing secretory granules in the collagen gland of the foot and are assumed to provide a viscoelastic matrix around the collagenous fibers in byssal threads.

Effect of ECM2 expression on bovine skeletal muscle-derived satellite cell differentiation.

PubMed

Liu, Chang; Tong, Huili; Li, Shufeng; Yan, Yunqin

2018-05-01

Extracellular matrix components have important regulatory functions during cell proliferation and differentiation. In recent study, extracellular matrix were shown to have a strong effect on skeletal muscle differentiation. Here, we aimed to elucidate the effects of extracellular matrix protein 2 (ECM2), an extracellular matrix component, on the differentiation of bovine skeletal muscle-derived satellite cells (MDSCs). Western blot and immunofluorescence analyses were used to elucidate the ECM2 expression pattern in bovine MDSCs during differentiation in vitro. CRISPR/Cas9 technology was used to activate or inhibit ECM2 expression to study its effects on the in vitro differentiation of bovine MDSCs. ECM2 expression was shown to increase gradually during bovine MDSC differentiation, and the levels of this protein were higher in more highly differentiated myotubes. ECM2 activation promoted MDSC differentiation, whereas its suppression inhibited the differentiation of these cells. Here, for the first time, we demonstrated the importance of ECM2 expression during bovine MDSC differentiation; these results could lead to treatments that help to increase beef cattle muscularity. © 2018 International Federation for Cell Biology.

Extracellular DNA and lipoteichoic acids interact with exopolysaccharides in the extracellular matrix of Streptococcus mutans biofilms

PubMed Central

Castillo Pedraza, Midian C.; Novais, Tatiana F.; Faustoferri, Roberta C.; Quivey, Robert G.; Terekhov, Anton; Hamaker, Bruce R.; Klein, Marlise I.

2018-01-01

Streptococcus mutans -derived exopolysaccharides are virulence determinants in the matrix of biofilms that cause caries. Extracellular DNA (eDNA) and lipoteichoic acid (LTA) are found in cariogenic biofilms, but their functions are unclear. Therefore, strains of S. mutans carrying single deletions that would modulate matrix components were used: eDNA – ΔlytS and ΔlytT; LTA – ΔdltA and ΔdltD; and insoluble exopolysaccharide – ΔgtfB. Single-species (parental strain S. mutans UA159 or individual mutant strains) and mixed-species (UA159 or mutant strain, Actinomyces naeslundii and Streptococcus gordonii) biofilms were evaluated. Distinct amounts of matrix components were detected, depending on the inactivated gene. eDNA was found to be cooperative with exopolysaccharide in early phases, while LTA played a larger role in the later phases of biofilm development. The architecture of mutant strains biofilms was distinct (vs UA159), demonstrating that eDNA and LTA influence exopolysaccharide distribution and microcolony organization. Thus, eDNA and LTA may shape exopolysaccharide structure, affecting strategies for controlling pathogenic biofilms. PMID:28946780

Fourier transform infrared spectroscopy to quantify collagen and elastin in an in vitro model of extracellular matrix degradation in aorta.

PubMed

Cheheltani, Rabee; McGoverin, Cushla M; Rao, Jayashree; Vorp, David A; Kiani, Mohammad F; Pleshko, Nancy

2014-06-21

Extracellular matrix (ECM) is a key component and regulator of many biological tissues including aorta. Several aortic pathologies are associated with significant changes in the composition of the matrix, especially in the content, quality and type of aortic structural proteins, collagen and elastin. The purpose of this study was to develop an infrared spectroscopic methodology that is comparable to biochemical assays to quantify collagen and elastin in aorta. Enzymatically degraded porcine aorta samples were used as a model of ECM degradation in abdominal aortic aneurysm (AAA). After enzymatic treatment, Fourier transform infrared (FTIR) spectra of the aortic tissue were acquired by an infrared fiber optic probe (IFOP) and FTIR imaging spectroscopy (FT-IRIS). Collagen and elastin content were quantified biochemically and partial least squares (PLS) models were developed to predict collagen and elastin content in aorta based on FTIR spectra. PLS models developed from FT-IRIS spectra were able to predict elastin and collagen content of the samples with strong correlations (RMSE of validation = 8.4% and 11.1% of the range respectively), and IFOP spectra were successfully used to predict elastin content (RMSE = 11.3% of the range). The PLS regression coefficients from the FT-IRIS models were used to map collagen and elastin in tissue sections of degraded porcine aortic tissue as well as a human AAA biopsy tissue, creating a similar map of each component compared to histology. These results support further application of FTIR spectroscopic techniques for evaluation of AAA tissues.

Fourier Transform Infrared Spectroscopy to Quantify Collagen and Elastin in an In Vitro Model of Extracellular Matrix Degradation in Aorta

PubMed Central

Cheheltani, Rabee; McGoverin, Cushla M.; Rao, Jayashree; Vorp, David A.; Kiani, Mohammad F.; Pleshko, N.

2014-01-01

Extracellular matrix (ECM) is a key component and regulator of many biological tissues including aorta. Several aortic pathologies are associated with significant changes in the composition of the matrix, especially in the content, quality and type of aortic structural proteins, collagen and elastin. The purpose of this study was to develop an infrared spectroscopic methodology that is comparable to biochemical assays to quantify collagen and elastin in aorta. Enzymatically degraded porcine aorta samples were used as a model of ECM degradation in abdominal aortic aneurysm (AAA). After enzymatic treatment, Fourier transform infrared (FTIR) spectra of the aortic tissue were acquired by an infrared fiber optic probe (IFOP) and FTIR imaging spectroscopy (FT-IRIS). Collagen and elastin content were quantified biochemically and partial least squares (PLS) models were developed to predict collagen and elastin content in aorta based on FTIR spectra. PLS models developed from FT-IRIS spectra were able to predict elastin and collagen content of the samples with strong correlations (RMSE of validation = 8.4% and 11.1% of the range respectively), and IFOP spectra were successfully used to predict elastin content (RMSE = 11.3% of the range). The PLS regression coefficients from the FT-IRIS models were used to map collagen and elastin in tissue sections of degraded porcine aortic tissue as well as a human AAA biopsy tissue, creating a similar map of each component compared to histology. These results support further application of FTIR spectroscopic techniques for evaluation of AAA tissues. PMID:24761431