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Sample records for active matrix oled

  1. Active Matrix OLED Test Report

    NASA Technical Reports Server (NTRS)

    Salazar, George

    2013-01-01

    This report focuses on the limited environmental testing of the AMOLED display performed as an engineering evaluation by The NASA Johnson Space Center (JSC)-specifically. EMI. Thermal Vac, and radiation tests. The AMOLED display is an active-matrix Organic Light Emitting Diode (OLED) technology. The testing provided an initial understanding of the technology and its suitability for space applications. Relative to light emitting diode (LED) displays or liquid crystal displays (LCDs), AMOLED displays provide a superior viewing experience even though they are much lighter and smaller, produce higher contrast ratio and richer colors, and require less power to operate than LCDs. However, AMOLED technology has not been demonstrated in a space environment. Therefore, some risks with the technology must be addressed before they can be seriously considered for human spaceflight. The environmental tests provided preliminary performance data on the ability of the display technology to handle some of the simulated induced space/spacecraft environments that an AMOLED display will see during a spacecraft certification test program. This engineering evaluation is part of a Space Act Agreement (SM) between The NASA/JSC and Honeywell International (HI) as a collaborative effort to evaluate the potential use of AMOLED technology for future human spaceflight missions- both government-led and commercial. Under this SM, HI is responsible for doing optical performance evaluation, as well as temperature and touch screen studies. The NASA/JSC is responsible for performing environmental testing comprised of EMI, Thermal Vac, and radiation tests. Additionally, as part of the testing, limited optical data was acquired to assess performance as the display was subjected to the induced environments. The NASA will benefit from this engineering evaluation by understanding AMOLED suitability for future use in space as well as becoming a smarter buyer (or developer) of the technology. HI benefits

  2. Color tunability in multilayer OLED based on DCM doped in a PVK matrix

    NASA Astrophysics Data System (ADS)

    Petrova, P. K.; Ivanov, P. I.; Tomova, R. L.

    2014-12-01

    In this work, we present our achievements in color tunability in novel multilayer organic light-emitting diodes (OLEDs) based on DCM (4-(Dicyanomethylene)-2-methyl-6-[p- (dimethylamino)styryl]-4H-pyran) as red emitter doped in a composite PVK:TPD holetransporting layer, DPVBi (4,4'-Bis(2,2-diphenylvinyl)-1,1'-biphenyl) as a separate blue emitting layer, BAlq (aluminum bis(2-methyl-8-quinolinate)-4-phenylphenolate) as holeblocking layer and blue emitter at the same time, and Zn(BTz)2 (zinc bis(2-(2-hydroxyphenyl) benzothiazole)) as yellow emitter and electron transporting layer. By modification of the OLED structure and changing the DCM doped concentration in the matrix (in the range of 0 up to 5 %) the color tunability of OLED structures has been obtained. The efficiencies, luminance and chromaticity coordinates of the fabricated OLED structures have been specified.

  3. OLED study for military applications

    NASA Astrophysics Data System (ADS)

    Barre, F.; Chiquard, A.; Faure, S.; Landais, L.; Patry, P.

    2005-07-01

    The presentation deals with some applications of OLED displays in military optronic systems, which are scheduled by SAGEM DS (Defence and Security). SAGEM DS, one of the largest group in the defence and security market, is currently investigating OLED Technologies for military programs. This technology is close from being chosen for optronic equipment such as future infantry night vision goggles, rifle-sight, or, more generally, vision enhancement systems. Most of those applications requires micro-display with an active matrix size below 1". Some others, such as, for instance, ruggedized flat displays do have a need for higher active matrix size (1,5" to 15"). SAGEM DS takes advantages of this flat, high luminance and emissive technology in highly integrated systems. In any case, many requirements have to be fulfilled: ultra-low power consumption, wide viewing angle, good pixel to pixel uniformity, and satisfactory behaviour in extreme environmental conditions.... Accurate measurements have been achieved at SAGEM DS on some micro display OLEDs and will be detailed: luminance (over 2000 cd/m2 achieved), area uniformity and pixel to pixel uniformity, robustness at low and high temperature (-40°C to +60°C), lifetime. These results, which refer to military requirements, provide a valuable feedback representative of the state of the art OLED performances.

  4. Production and detailed characterization of biologically active olive pollen allergen Ole e 1 secreted by the yeast Pichia pastoris.

    PubMed

    Huecas, S; Villalba, M; González, E; Martínez-Ruiz, A; Rodríguez, R

    1999-04-01

    The glycoprotein Ole e 1 is a significant aeroallergen from the olive tree (Olea europaea) pollen, with great clinical relevance in the Mediterranean area. To produce a biologically active form of recombinant Ole e 1, heterologous expression in the methylotrophic yeast Pichia pastoris was carried out. A cDNA encoding Ole e 1, fused to a Saccharomyces cerevisiae alpha-mating factor prepropeptide using the pPIC9 vector, was inserted into the yeast genome under the control of the AOX1 promoter. After induction with methanol, the protein secreted into the extracellular medium was purified by ion-exchange and size-exclusion chromatography. The structure of the isolated recombinant Ole e 1 was determined by chemical and spectroscopic techniques, and its immunological properties analysed by blotting and ELISA inhibition with Ole e 1-specific monoclonal antibodies and IgE from sera of allergic patients. The allergen was produced at a yield of 60 mg per litre of culture as a homogeneous glycosylated protein of around 18.5 kDa. Recombinant Ole e 1 appears to be properly folded, as it displays spectroscopic properties (CD and fluorescence) and immunological reactivities (IgG binding to monoclonal antibodies sensitive to denaturation and IgE from sera of allergic patients) indistinguishable from those of the natural protein. This approach gives high-yield production of homogeneous and biologically active allergen, which should be useful for scientific and clinical purposes.

  5. Thermally activated delayed fluorescence OLEDs with fully solution processed organic layers exhibiting nearly 10% external quantum efficiency.

    PubMed

    Albrecht, Ken; Matsuoka, Kenichi; Yokoyama, Daisuke; Sakai, Yoshiya; Nakayama, Akira; Fujita, Katsuhiko; Yamamoto, Kimihisa

    2017-02-21

    New solution processable and laminatable terminally modified carbazole-triazine thermally activated delayed fluorescence (TADF) dendrimers are reported. An OLED device with fully solution processed organic layers exhibited an external quantum efficiency of up to 9.4% at 100 cd m(-2).

  6. Highly efficient fully transparent inverted OLEDs

    NASA Astrophysics Data System (ADS)

    Meyer, J.; Winkler, T.; Hamwi, S.; Schmale, S.; Kröger, M.; Görrn, P.; Johannes, H.-H.; Riedl, T.; Lang, E.; Becker, D.; Dobbertin, T.; Kowalsky, W.

    2007-09-01

    One of the unique selling propositions of OLEDs is their potential to realize highly transparent devices over the visible spectrum. This is because organic semiconductors provide a large Stokes-Shift and low intrinsic absorption losses. Hence, new areas of applications for displays and ambient lighting become accessible, for instance, the integration of OLEDs into the windshield or the ceiling of automobiles. The main challenge in the realization of fully transparent devices is the deposition of the top electrode. ITO is commonly used as transparent bottom anode in a conventional OLED. To obtain uniform light emission over the entire viewing angle and a low series resistance, a TCO such as ITO is desirable as top contact as well. However, sputter deposition of ITO on top of organic layers causes damage induced by high energetic particles and UV radiation. We have found an efficient process to protect the organic layers against the ITO rf magnetron deposition process of ITO for an inverted OLED (IOLED). The inverted structure allows the integration of OLEDs in more powerful n-channel transistors used in active matrix backplanes. Employing the green electrophosphorescent material Ir(ppy) 3 lead to IOLED with a current efficiency of 50 cd/A and power efficiency of 24 lm/W at 100 cd/m2. The average transmittance exceeds 80 % in the visible region. The on-set voltage for light emission is lower than 3 V. In addition, by vertical stacking we achieved a very high current efficiency of more than 70 cd/A for transparent IOLED.

  7. Matrix effects on the triplet state of the OLED emitter Ir(4,6-dFppy)2(pic) (FIrpic): investigations by high-resolution optical spectroscopy.

    PubMed

    Rausch, Andreas F; Thompson, Mark E; Yersin, Hartmut

    2009-03-02

    The sky-blue emitting compound Ir(4,6-dFppy)(2)(pic) (iridium(III)bis[2-(4',6'-difluorophenyl)pyridinato-N,C(2')]-picolinate), commonly referred to as FIrpic and representing a well-known emitter material for organic light emitting diodes (OLEDs), has been investigated in detail by optical spectroscopy. Studies at temperatures from T = 1.5 K to T = 300 K were carried out in CH(2)Cl(2) and tetrahydrofuran (THF). In CH(2)Cl(2), two discrete sites were observed at cryogenic temperatures and studied by site-selective, high-resolution spectroscopy. The investigations reveal that the molecules located at the two sites exhibit distinctly different photophysical properties. For example, the three substates I, II, and III of the emitting triplet state T(1) of the low-energy site A show a distinctly larger zero-field splitting (ZFS) and exhibit shorter individual decay times than observed for the high-energy site B. The vibrational satellite structures in the emission spectra of the substates I(A) and I(B) exhibit clear differences in the ranges of metal-ligand (M-L) vibrations. For the compound studied in a polycrystalline THF host, giving only strongly inhomogeneously broadened spectra, the ZFS parameters and substate decay times vary in a similar range as observed for the two discrete sites in the CH(2)Cl(2) matrix. Thus, the amount of ZFS, the emission decay times, and also the intensities of the M-L vibrational satellites are affected by the matrix cage, that is, the host environment of the emitting complex. These properties are discussed with respect to variations of spin-orbit coupling routes. In particular, changes of d-orbital admixtures, that is, differences of the metal-to-ligand charge transfer (MLCT) character in the emitting triplet, play an important role. The matrix effects are expected to be also of importance for FIrpic and other Ir(III) compounds when applied as emitters in amorphous OLED matrixes.

  8. OLED devices

    SciTech Connect

    Sapochak, Linda Susan; Burrows, Paul Edward; Bimalchandra, Asanga

    2011-02-22

    An OLED device having an emission layer formed of an ambipolar phosphine oxide host material and a dopant, a hole transport layer in electrical communication with an anode, an electron transport layer in communication with a cathode, wherein the HOMO energy of the hole transport layer is substantially the same as the HOMO energy of the ambipolar host in the emission layer, and the LUMO energy of the electron transport layer is substantially the same as the LUMO energy of the ambipolar host in the emission layer.

  9. OLED area illumination source

    DOEpatents

    Foust, Donald Franklin; Duggal, Anil Raj; Shiang, Joseph John; Nealon, William Francis; Bortscheller, Jacob Charles

    2008-03-25

    The present invention relates to an area illumination light source comprising a plurality of individual OLED panels. The individual OLED panels are configured in a physically modular fashion. Each OLED panel comprising a plurality of OLED devices. Each OLED panel comprises a first electrode and a second electrode such that the power being supplied to each individual OLED panel may be varied independently. A power supply unit capable of delivering varying levels of voltage simultaneously to the first and second electrodes of each of the individual OLED panels is also provided. The area illumination light source also comprises a mount within which the OLED panels are arrayed.

  10. An olive pollen protein with allergenic activity, Ole e 10, defines a novel family of carbohydrate-binding modules and is potentially implicated in pollen germination

    PubMed Central

    2005-01-01

    CBMs (carbohydrate-binding modules) are the most common non-catalytic modules associated with enzymes active in plant cell-wall hydrolysis. They have been frequently identified by amino acid sequence alignments, but only a few have been experimentally established to have a carbohydrate-binding activity. A small olive pollen protein, Ole e 10 (10 kDa), has been described as a major inducer of type I allergy in humans. In the present study, the ability of Ole e 10 to bind several polysaccharides has been analysed by affinity gel electrophoresis, which demonstrated that the protein bound 1,3-β-glucans preferentially. Analytical ultracentrifugation studies confirmed binding to laminarin, at a protein/ligand ratio of 1:1. The interaction of Ole e 10 with laminarin induced a conformational change in the protein, as detected by CD and fluorescence analyses, and an increase of 3.6 °C in the thermal denaturation temperature of Ole e 10 in the presence of the glycan. These results, and the absence of alignment of the sequence of Ole e 10 with that of any classified CBM, indicate that this pollen protein defines a novel family of CBMs, which we propose to name CBM43. Immunolocalization of Ole e 10 in mature and germinating pollen by transmission electron microscopy and confocal laser scanning microscopy demonstrated the co-localization of Ole e 10 and callose (1,3-β-glucan) in the growing pollen tube, suggesting a role for this protein in the metabolism of carbohydrates and in pollen tube wall re-formation during germination. PMID:15882149

  11. Virtual screening for OLED materials

    NASA Astrophysics Data System (ADS)

    Halls, Mathew D.; Giesen, David J.; Hughes, Thomas F.; Goldberg, Alexander; Cao, Yixiang; Kwak, H. Shaun; Gavartin, Jacob

    2014-10-01

    Organic light-emitting diodes (OLEDs) are under widespread investigation to displace or complement inorganic optoelectronic devices for solid-state lighting and active displays. The materials comprising the active layers in OLED devices are selected or designed to provide the required intrinsic and extrinsic electronic properties needed for efficient charge injection and transport, and desired stability and emissive properties. The chemical design space for OLED materials is enormous and there is need for the development of computational approaches to help identify the most promising chemical solutions for experimental development. In this work we present a multi-scale simulation approach to efficiently screen libraries of potential OLED molecular materials. The workflow to assess potential OLED materials is: 1) evaluation based on first-principles prediction of key intrinsic properties (EHOMO, ELUMO, λe/h, Etriplet), 2) classical simulation of thin film morphology (RDF, ρ), and 3) first-principles evaluation of electron coupling for donor-acceptor pairs (Hab) from the simulated condensed phase morphology.

  12. Driving platform for OLED lighting investigations

    NASA Astrophysics Data System (ADS)

    Vogel, Uwe; Elgner, Andreas; Kreye, Daniel; Amelung, Jörg; Scholles, Michael

    2006-08-01

    OLED technology may be excellently suitable for lighting applications by combining high efficiency, cost effective manufacturing and the use of low cost materials. Certain issues remain to be solved so far, including OLED brightness, color, lifetime, large area uniformity and encapsulation. Another aspect, that might be capable in addressing some of the mentioned issues, is OLED lighting electrical driving. We report on the design of a driving platform for OLED lighting test panels or substrates. It is intended for being a test environment for lighting substrates as well as demonstration/presentation environment. It is based on a 128-channel passive-matrix driver/controller ASIC OC2. Its key component is an MSP430-compatible 16-bit micro-controller core including embedded Flash memory (program), EEPROM (parameter), and RAM (data memory). A significant feature of the device is an electronic approach for improving the lifetime/uniformity behavior of connected OLED. The embedded micro-controller is the key to the high versatility of OC2, since by firmware modification it can be adapted to various applications and conditions. Here its application for an OLED lighting driving platform is presented. Major features of this platform are PC-control mode (via USB interface), stand-alone mode (no external control necessary, just power supply), on-board OLED panel parameter storage, flat geometry of OLED lighting panel carrier (board), AC and DC driving regimes, adjustable reverse voltage, dedicated user SW (PC/Windows-based), sub-tile patterning and single sub-tile control, combination of multiple channels for increasing driving current. This publication contains results of the project "High Brightness OLEDs for ICT & Next Generation Lighting Applications" (OLLA), funded by the European Commission.

  13. EDITORIAL: Flexible OLEDs and organic electronics Flexible OLEDs and organic electronics

    NASA Astrophysics Data System (ADS)

    Kim, Jang-Joo; Han, Min-Koo; Noh, Yong-Young

    2011-03-01

    Following the great discovery of the electrically conducting polymer, doped polyacetylene, which was honorably recognized in 2000 with the Nobel Prize in chemistry, conjugated molecules, i.e. organic semiconductors, have become an attractive class of active elements for various electronic or opto-electronic applications. Significant effort has been made in both academia and industry to investigate π-conjugated molecules for their unique electrical or opto-electrical properties over the last three decades. The discovery of electroluminescence in conjugated small molecules in 1982 and in polymers in 1989 was a major breakthrough, bringing those molecules to commercial applications within reach for the first time in (opto-)electronic devices, such as organic light-emitting diodes (OLEDs), photovoltaic cells (OPVs), and field-effect transistors (OFETs). Nowadays, we use OLED displays in everyday life in mobile devices. The potential of these devices, which have been fabricated with conjugated molecules, lies in the possibility to combine the advantages of solution processability, chemical tunability and material strength of polymers with the typical properties of plastics, to realize low-cost, large-area electronic devices on flexible substrates by solution deposition and direct-write graphic art printing techniques. The articles in the flexible OLEDs and organic electronics special issue in Semiconductor Science and Technology deal with a diversity of topics and effectively reflect the current status of research from all over the world on various organic electronic devices, including OLEDs, OPVs, and OFETs. Firstly, S Park et al describe the recent progress in thin-film encapsulation techniques for flexible AM-OLED and large-area OLED lightings, and their applications are discussed by J-W Park et al. Flexible active-matrix OLEDs on plastics require stable and flexible thin-film transistors processed at low temperature. Metal oxide thin-film transistors are proposed

  14. High Brightness OLED Lighting

    SciTech Connect

    Spindler, Jeffrey; Kondakova, Marina; Boroson, Michael; Hamer, John

    2016-05-25

    In this work we describe the technology developments behind our current and future generations of high brightness OLED lighting panels. We have developed white and amber OLEDs with excellent performance based on the stacking approach. Current products achieve 40-60 lm/W, while future developments focus on achieving 80 lm/W or higher.

  15. Release of OLe peanut

    Technology Transfer Automated Retrieval System (TEKTRAN)

    OLe is a high oleic Spanish-type peanut that has excellent yield and enhanced Sclerotinia blight and pod rot resistance when compared to other high oleic Spanish cultivars. The purpose for releasing OLe is to provide peanut producers with a true Spanish peanut that is high oleic and has enhanced yi...

  16. OLED panel with fuses

    SciTech Connect

    Levermore, Levermore; Pang, Huiqing; Rajan, Kamala

    2014-09-16

    Embodiments may provide a first device that may comprise a substrate, a plurality of conductive bus lines disposed over the substrate, and a plurality of OLED circuit elements disposed on the substrate, where each of the OLED circuit elements comprises one and only one pixel electrically connected in series with a fuse. Each pixel may further comprise a first electrode, a second electrode, and an organic electroluminescent (EL) material disposed between the first and the second electrodes. The fuse of each of the plurality of OLED circuit elements may electrically connect each of the OLED circuit elements to at least one of the plurality of bus lines. Each of the plurality of bus lines may be electrically connected to a plurality of OLED circuit elements that are commonly addressable and at least two of the bus lines may be separately addressable.

  17. Active Matrix Driving Organic Light-Emitting Diode Panel Using Organic Thin-Film Transistors

    NASA Astrophysics Data System (ADS)

    Ohta, Satoru; Chuman, Takashi; Miyaguchi, Satoshi; Satoh, Hideo; Tanabe, Takahisa; Okuda, Yoshiyuki; Tsuchida, Masami

    2005-06-01

    We developed an active matrix driving organic light-emitting diode (OLED) panel on a glass substrate using two organic thin-film transistors (OTFTs) per pixel, a switching OTFT and a driving OTFT. The OTFTs are bottom contact structures with the high-dielectric constant gate insulator tantalum oxide (Ta2O5, relative dielectric constant of 23) produced by anodization in ammonium adipate solution and with pentacene as the active layer. The W/L (where W and L are the OTFTs channel width and length, respectively) was 400 μm/10 μm for the switching OTFTs and 680 μm/10 μm for the driving OTFTs. The characteristics of the OTFTs were improved by treating the Ta2O5 surface with hexamethyldisilazane (HMDS), so that the field-effect mobility was 2.0× 10-1 cm2 V-1 s-1 and the current on/off ratio was 105. A green phosphorescent dopant, tris(2-phenylpyridine)iridium [Ir(ppy)3], was used for the OLED layer. The panel had 8× 8 pixels and the aperture ratio was 27%. We confirmed a 16-gray-scale representation and a luminance of 400 cd/m2.

  18. OLEDS FOR GENERAL LIGHTING

    SciTech Connect

    Anil Duggal; Don Foust; Chris Heller; Bill Nealon; Larry Turner; Joe Shiang; Nick Baynes; Tim Butler; Nalin Patel

    2004-02-29

    The goal of this program was to reduce the long term technical risks that were keeping the lighting industry from embracing and developing organic light-emitting diode (OLED) technology for general illumination. The specific goal was to develop OLEDs for lighting to the point where it was possible to demonstrate a large area white light panel with brightness and light quality comparable to a fluorescence source and with an efficacy comparable to that of an incandescent source. it was recognized that achieving this would require significant advances in three area: (1) the improvement of white light quality for illumination, (2) the improvement of OLED energy efficiency at high brightness, and (3) the development of cost-effective large area fabrication techniques. The program was organized such that, each year, a ''deliverable'' device would be fabricated which demonstrated progress in one or more of the three critical research areas. In the first year (2001), effort concentrated on developing an OLED capable of generating high illumination-quality white light. Ultimately, a down-conversion method where a blue OLED was coupled with various down-conversion layers was chosen. Various color and scattering models were developed to aid in material development and device optimization. The first year utilized this approach to deliver a 1 inch x 1 inch OLED with higher illumination-quality than available fluorescent sources. A picture of this device is shown and performance metrics are listed. To their knowledge, this was the first demonstration of true illumination-quality light from an OLED. During the second year, effort concentrated on developing a scalable approach to large area devices. A novel device architecture consisting of dividing the device area into smaller elements that are monolithically connected in series was developed. In the course of this development, it was realized that, in addition to being scalable, this approach made the device tolerant to the most

  19. Active Matrix Organic Light Emitting Diode (AMOLED) Environmental Test Report

    NASA Technical Reports Server (NTRS)

    Salazar, George A.

    2013-01-01

    This report focuses on the limited environmental testing of the AMOLED display performed as an engineering evaluation by The NASA Johnson Space Center (JSC)-specifically. EMI. Thermal Vac, and radiation tests. The AMOLED display is an active-matrix Organic Light Emitting Diode (OLED) technology. The testing provided an initial understanding of the technology and its suitability for space applications. Relative to light emitting diode (LED) displays or liquid crystal displays (LCDs), AMOLED displays provide a superior viewing experience even though they are much lighter and smaller, produce higher contrast ratio and richer colors, and require less power to operate than LCDs. However, AMOLED technology has not been demonstrated in a space environment. Therefore, some risks with the technology must be addressed before they can be seriously considered for human spaceflight. The environmental tests provided preliminary performance data on the ability of the display technology to handle some of the simulated induced space/spacecraft environments that an AMOLED display will see during a spacecraft certification test program. This engineering evaluation is part of a Space Act Agreement (SM) between The NASA/JSC and Honeywell International (HI) as a collaborative effort to evaluate the potential use of AMOLED technology for future human spaceflight missions- both government-led and commercial. Under this SM, HI is responsible for doing optical performance evaluation, as well as temperature and touch screen studies. The NASA/JSC is responsible for performing environmental testing comprised of EMI, Thermal Vac, and radiation tests. Additionally, as part of the testing, limited optical data was acquired to assess performance as the display was subjected to the induced environments. The NASA will benefit from this engineering evaluation by understanding AMOLED suitability for future use in space as well as becoming a smarter buyer (or developer) of the technology. HI benefits

  20. Industrialization of OLEDs for Lighting Applications and Displays

    NASA Astrophysics Data System (ADS)

    Brunner, Klemens

    2005-03-01

    Organic light emitting diodes (OLEDs) are an extremely versatile technology that can be tailored to specific applications. The flexibility and adaptability of OLED technology is a result of the variety of material systems and fabrication technologies that can be applied. In this contribution we investigate and compare several material systems and fabrication technologies from an application point of view. Applications without the need of micro-scale structuring open a new window of opportunity for evaporated small molecules. Small molecular OLEDs have the potential for high efficiencies at high brightness rendering them ideal for lighting applications . The first part of our contribution will establish the boundary conditions for lighting applications and we will introduces the current status of our industrialization program for OLEDs for lighting and present our perspective of the OLED lighting market. In the second part of the contribution we will focus on alternative OLED technologies that offer interesting perspectives for industrial fabrication. The light-emitting electrochemical cell (LEC) is a type of organic electroluminescent device that has all the attractive features of the OLED but does not have the drawbacks of reactive cathodes and thin active layers. The crucial difference with OLEDs is that the active layer of a LEC contains mobile ions. This results in two very important advantages for large-area lighting applications compared with traditional OLEDs: (i) thick electroactive layers (ii) and matching of the work function of the electrodes with the energy levels of the electroluminescent material is not required. This means that non-reactive metals such as Ag or Au can be used instead of e.g. Ba. We have studied several types of LECs with the aim to assess the above-mentioned benefits for large-area lighting . Finally to show the immense spectrum of production methods for OLEDs we will conclude the contribution with a manufacturing technique for

  1. Neutrophil activator of matrix metalloproteinase-2 (NAM).

    PubMed

    Rollo, Ellen E; Hymowitz, Michelle; Schmidt, Cathleen E; Montana, Steve; Foda, Hussein; Zucker, Stanley

    2006-01-01

    We have isolated a novel soluble factor(s), neutrophil activator of matrix metalloproteinases (NAM), secreted by unstimulated normal human peripheral blood neutrophils that causes the activation of cell secreted promatrix metalloproteinase-2 (proMMP-2). Partially purified preparations of NAM have been isolated from the conditioned media of neutrophils employing gelatin-Sepharose chromatography and differential membrane filter centrifugation. NAM activity, as assessed by exposing primary human umbilical vein endothelial cells (HUVEC) or HT1080 cells to NAM followed by gelatin zymography, was seen within one hour. Tissue inhibitor of metalloproteinase-2 (TIMP-2) and hydroxamic acid derived inhibitors of MMPs (CT1746 and BB94) abrogated the activation of proMMP-2 by NAM, while inhibitors of serine and cysteine proteases showed no effect. NAM also produced an increase in TIMP-2 binding to HUVEC and HT1080 cell surfaces that was inhibited by TIMP-2, CT1746, and BB94. Time-dependent increases in MT1-MMP protein and mRNA were seen following the addition of NAM to cells. These data support a role for NAM in cancer dissemination.

  2. The theoretical study of passive and active optical devices via planewave based transfer (scattering) matrix method and other approaches

    SciTech Connect

    Zhuo, Ye

    2011-01-01

    In this thesis, we theoretically study the electromagnetic wave propagation in several passive and active optical components and devices including 2-D photonic crystals, straight and curved waveguides, organic light emitting diodes (OLEDs), and etc. Several optical designs are also presented like organic photovoltaic (OPV) cells and solar concentrators. The first part of the thesis focuses on theoretical investigation. First, the plane-wave-based transfer (scattering) matrix method (TMM) is briefly described with a short review of photonic crystals and other numerical methods to study them (Chapter 1 and 2). Next TMM, the numerical method itself is investigated in details and developed in advance to deal with more complex optical systems. In chapter 3, TMM is extended in curvilinear coordinates to study curved nanoribbon waveguides. The problem of a curved structure is transformed into an equivalent one of a straight structure with spatially dependent tensors of dielectric constant and magnetic permeability. In chapter 4, a new set of localized basis orbitals are introduced to locally represent electromagnetic field in photonic crystals as alternative to planewave basis. The second part of the thesis focuses on the design of optical devices. First, two examples of TMM applications are given. The first example is the design of metal grating structures as replacements of ITO to enhance the optical absorption in OPV cells (chapter 6). The second one is the design of the same structure as above to enhance the light extraction of OLEDs (chapter 7). Next, two design examples by ray tracing method are given, including applying a microlens array to enhance the light extraction of OLEDs (chapter 5) and an all-angle wide-wavelength design of solar concentrator (chapter 8). In summary, this dissertation has extended TMM which makes it capable of treating complex optical systems. Several optical designs by TMM and ray tracing method are also given as a full complement of this

  3. A flexible organic active matrix circuit fabricated using novel organic thin film transistors and organic light-emitting diodes

    NASA Astrophysics Data System (ADS)

    Gutiérrez-Heredia, G.; González, L. A.; Alshareef, H. N.; Gnade, B. E.; Quevedo-López, M.

    2010-11-01

    We present an active matrix circuit fabricated on plastic (polyethylene naphthalene, PEN) and glass substrates using organic thin film transistors and organic capacitors to control organic light-emitting diodes (OLEDs). The basic circuit is fabricated using two pentacene-based transistors and a capacitor using a novel aluminum oxide/parylene stack (Al2O3/parylene) as the dielectric for both the transistor and the capacitor. We report that our circuit can deliver up to 15 µA to each OLED pixel. To achieve 200 cd m-2 of brightness a 10 µA current is needed; therefore, our approach can initially deliver 1.5× the required current to drive a single pixel. In contrast to parylene-only devices, the Al2O3/parylene stack does not fail after stressing at a field of 1.7 MV cm-1 for >10 000 s, whereas 'parylene only' devices show breakdown at approximately 1000 s. Details of the integration scheme are presented.

  4. Modifying the organic/electrode interface in Organic Solar Cells (OSCs) and improving the efficiency of solution-processed phosphorescent Organic Light-Emitting Diodes (OLEDs)

    NASA Astrophysics Data System (ADS)

    Xiao, Teng

    Organic semiconductors devices, such as, organic solar cells (OSCs), organic light-emitting diodes (OLEDs) and organic field-effect transistors (OFETs) have drawn increasing interest in recent decades. As organic materials are flexible, light weight, and potentially low-cost, organic semiconductor devices are considered to be an alternative to their inorganic counterparts. This dissertation will focus mainly on OSCs and OLEDs. As a clean and renewable energy source, the development of OSCs is very promising. Cells with 9.2% power conversion efficiency (PCE) were reported this year, compared to < 8% two years ago. OSCs belong to the so-called third generation solar cells and are still under development. While OLEDs are a more mature and better studied field, with commercial products already launched in the market, there are still several key issues: (1) the cost of OSCs/OLEDs is still high, largely due to the costly manufacturing processes; (2) the efficiency of OSCs/OLEDs needs to be improved; (3) the lifetime of OSCs/OLEDs is not sufficient compared to their inorganic counterparts; (4) the physics models of the behavior of the devices are not satisfactory. All these limitations invoke the demand for new organic materials, improved device architectures, low-cost fabrication methods, and better understanding of device physics. For OSCs, we attempted to improve the PCE by modifying the interlayer between active layer/metal. We found that ethylene glycol (EG) treated poly(3,4-ethylenedioxy-thiophene):polystyrenesulfonate (PEDOT: PSS) improves hole collection at the metal/polymer interface, furthermore it also affects the growth of the poly(3-hexylthiophene) (P3HT):phenyl-C 61-butyric acid methyl ester (PCBM) blends, making the phase segregation more favorable for charge collection. We then studied organic/inorganic tandem cells. We also investigated the effect of a thin LiF layer on the hole-collection of copper phthalocyanine (CuPc)/C70-based small molecular OSCs. A

  5. Accelerated discovery of OLED materials through atomic-scale simulation

    NASA Astrophysics Data System (ADS)

    Halls, Mathew D.; Giesen, David J.; Hughes, Thomas F.; Goldberg, Alexander; Cao, Yixiang; Kwak, H. Shaun; Mustard, Thomas J.; Gavartin, Jacob

    2016-09-01

    Organic light-emitting diode (OLED) devices are under widespread investigation to displace or complement inorganic optoelectronic devices for solid-state lighting and active displays. The materials in these devices are selected or designed according to their intrinsic and extrinsic electronic properties with concern for efficient charge injection and transport, and desired stability and light emission characteristics. The chemical design space for OLED materials is enormous and there is need for the development of computational approaches to help identify the most promising solutions for experimental development. In this work we will present examples of simulation approaches available to efficiently screen libraries of potential OLED materials; including first-principles prediction of key intrinsic properties, and classical simulation of amorphous morphology and stability. Also, an alternative to exhaustive computational screening is introduced based on a biomimetic evolutionary framework; evolving the molecular structure in the calculated OLED property design space.

  6. Integration of OLEDs in biomedical sensor systems: design and feasibility analysis

    NASA Astrophysics Data System (ADS)

    Rai, Pratyush; Kumar, Prashanth S.; Varadan, Vijay K.

    2010-04-01

    Organic (electronic) Light Emitting Diodes (OLEDs) have been shown to have applications in the field of lighting and flexible display. These devices can also be incorporated in sensors as light source for imaging/fluorescence sensing for miniaturized systems for biomedical applications and low-cost displays for sensor output. The current device capability aligns well with the aforementioned applications as low power diffuse lighting and momentary/push button dynamic display. A top emission OLED design has been proposed that can be incorporated with the sensor and peripheral electrical circuitry, also based on organic electronics. Feasibility analysis is carried out for an integrated optical imaging/sensor system, based on luminosity and spectrum band width. A similar study is also carried out for sensor output display system that functions as a pseudo active OLED matrix. A power model is presented for device power requirements and constraints. The feasibility analysis is also supplemented with the discussion about implementation of ink-jet printing and stamping techniques for possibility of roll to roll manufacturing.

  7. OLED with improved light outcoupling

    SciTech Connect

    Forrest, Stephen; Sun, Yiru

    2016-11-29

    An OLED may include regions of a material having a refractive index less than that of the substrate, or of the organic region, allowing for emitted light in a waveguide mode to be extracted into air. These regions can be placed adjacent to the emissive regions of an OLED in a direction parallel to the electrodes. The substrate may also be given a nonstandard shape to further improve the conversion of waveguide mode and/or glass mode light to air mode. The outcoupling efficiency of such a device may be up to two to three times the efficiency of a standard OLED. Methods for fabricating such a transparent or top-emitting OLED is also provided.

  8. Modifying the organic/electrode interface in Organic Solar Cells (OSCs) and improving the efficiency of solution-processed phosphorescent Organic Light-Emitting Diodes (OLEDs)

    SciTech Connect

    Xiao, Teng

    2012-01-01

    Organic semiconductors devices, such as, organic solar cells (OSCs), organic light-emitting diodes (OLEDs) and organic field-effect transistors (OFETs) have drawn increasing interest in recent decades. As organic materials are flexible, light weight, and potentially low-cost, organic semiconductor devices are considered to be an alternative to their inorganic counterparts. This dissertation will focus mainly on OSCs and OLEDs. As a clean and renewable energy source, the development of OSCs is very promising. Cells with 9.2% power conversion efficiency (PCE) were reported this year, compared to < 8% two years ago. OSCs belong to the so-called third generation solar cells and are still under development. While OLEDs are a more mature and better studied field, with commercial products already launched in the market, there are still several key issues: (1) the cost of OSCs/OLEDs is still high, largely due to the costly manufacturing processes; (2) the efficiency of OSCs/OLEDs needs to be improved; (3) the lifetime of OSCs/OLEDs is not sufficient compared to their inorganic counterparts; (4) the physics models of the behavior of the devices are not satisfactory. All these limitations invoke the demand for new organic materials, improved device architectures, low-cost fabrication methods, and better understanding of device physics. For OSCs, we attempted to improve the PCE by modifying the interlayer between active layer/metal. We found that ethylene glycol (EG) treated poly(3,4-ethylenedioxythiophene): polystyrenesulfonate (PEDOT: PSS) improves hole collection at the metal/polymer interface, furthermore it also affects the growth of the poly(3- hexylthiophene) (P3HT):phenyl-C61-butyric acid methyl ester (PCBM) blends, making the phase segregation more favorable for charge collection. We then studied organic/inorganic tandem cells. We also investigated the effect of a thin LiF layer on the hole-collection of copper phthalocyanine (CuPc)/C70-based small molecular OSCs. A

  9. Sorting of large-diameter semiconducting carbon nanotube and printed flexible driving circuit for organic light emitting diode (OLED)

    NASA Astrophysics Data System (ADS)

    Xu, Wenya; Zhao, Jianwen; Qian, Long; Han, Xianying; Wu, Liangzhuan; Wu, Weichen; Song, Minshun; Zhou, Lu; Su, Wenming; Wang, Chao; Nie, Shuhong; Cui, Zheng

    2014-01-01

    A novel approach was developed to sort a large-diameter semiconducting single-walled carbon nanotube (sc-SWCNT) based on copolyfluorene derivative with high yield. High purity sc-SWCNTs inks were obtained by wrapping arc-discharge SWCNTs with poly[2,7-(9,9-dioctylfluorene)-alt-4,7-bis(thiophen-2-yl)benzo-2,1,3-thiadiazole] (PFO-DBT) aided by sonication and centrifugation in tetrahydrofuran (THF). The sorted sc-SWCNT inks and nanosilver inks were used to print top-gated thin-film transistors (TFTs) on flexible substrates with an aerosol jet printer. The printed TFTs demonstrated low operating voltage, small hysteresis, high on-state current (up to 10-3 A), high mobility and on-off ratio. An organic light emitting diode (OLED) driving circuit was constructed based on the printed TFTs, which exhibited high on-off ratio up to 104 and output current up to 3.5 × 10-4 A at Vscan = -4.5 V and Vdd = 0.8 V. A single OLED was switched on with the driving circuit, showing the potential as backplanes for active matrix OLED applications.A novel approach was developed to sort a large-diameter semiconducting single-walled carbon nanotube (sc-SWCNT) based on copolyfluorene derivative with high yield. High purity sc-SWCNTs inks were obtained by wrapping arc-discharge SWCNTs with poly[2,7-(9,9-dioctylfluorene)-alt-4,7-bis(thiophen-2-yl)benzo-2,1,3-thiadiazole] (PFO-DBT) aided by sonication and centrifugation in tetrahydrofuran (THF). The sorted sc-SWCNT inks and nanosilver inks were used to print top-gated thin-film transistors (TFTs) on flexible substrates with an aerosol jet printer. The printed TFTs demonstrated low operating voltage, small hysteresis, high on-state current (up to 10-3 A), high mobility and on-off ratio. An organic light emitting diode (OLED) driving circuit was constructed based on the printed TFTs, which exhibited high on-off ratio up to 104 and output current up to 3.5 × 10-4 A at Vscan = -4.5 V and Vdd = 0.8 V. A single OLED was switched on with the driving

  10. Membrane type-1 matrix metalloprotease-independent activation of pro-matrix metalloprotease-2 by proprotein convertases.

    PubMed

    Koo, Bon-Hun; Kim, Hee-Hyun; Park, Michael Y; Jeon, Ok-Hee; Kim, Doo-Sik

    2009-11-01

    Matrix metalloprotease-2 is implicated in many biological processes and degrades extracellular and non-extracellular matrix molecules. Matrix metalloprotease-2 maintains a latent state through a cysteine-zinc ion pairing which, when disrupted, results in full enzyme activation. This pairing can be disrupted by a conformational change or cleavage within the propeptide. The best known activation mechanism for pro-matrix metalloprotease-2 occurs via cleavage of the propeptide by membrane type-1 matrix metalloprotease. However, significant residual activation of pro-matrix metalloprotease-2 is seen in membrane type-1 matrix metalloprotease knockout mice and in fibroblasts treated with metalloprotease inhibitors. These findings indicate the presence of a membrane type-1 matrix metalloprotease-independent activation mechanism for pro-matrix metalloprotease-2 in vivo, which prompted us to explore an alternative activation mechanism for pro-matrix metalloprotese-2. In this study, we demonstrate membrane type-1 matrix metalloprotease-independent propeptide processing of matrix metalloprotease-2 in HEK293F and various tumor cell lines, and show that proprotein convertases can mediate the processing intracellularly as well as extracellularly. Furthermore, processed matrix metalloprotease-2 exhibits enzymatic activity that is enhanced by intermolecular autolytic cleavage. Thus, our experimental data, taken together with the broad expression of proprotein convertases, suggest that the proprotein convertase-mediated processing may be a general activation mechanism for pro-matrix metalloprotease-2 in vivo.

  11. Catechol-based matrix metalloproteinase inhibitors with additional antioxidative activity.

    PubMed

    Tauro, Marilena; Laghezza, Antonio; Loiodice, Fulvio; Piemontese, Luca; Caradonna, Alessia; Capelli, Davide; Montanari, Roberta; Pochetti, Giorgio; Di Pizio, Antonella; Agamennone, Mariangela; Campestre, Cristina; Tortorella, Paolo

    2016-01-01

    New catechol-containing chemical entities have been investigated as matrix metalloproteinase inhibitors as well as antioxidant molecules. The combination of the two properties could represent a useful feature due to the potential application in all the pathological processes characterized by increased proteolytic activity and radical oxygen species (ROS) production, such as inflammation and photoaging. A series of catechol-based molecules were synthesized and tested for both proteolytic and oxidative inhibitory activity, and the detailed binding mode was assessed by crystal structure determination of the complex between a catechol derivative and the matrix metalloproteinase-8. Surprisingly, X-ray structure reveals that the catechol oxygens do not coordinates the zinc atom.

  12. Google matrix of the world network of economic activities

    NASA Astrophysics Data System (ADS)

    Kandiah, Vivek; Escaith, Hubert; Shepelyansky, Dima L.

    2015-07-01

    Using the new data from the OECD-WTO world network of economic activities we construct the Google matrix G of this directed network and perform its detailed analysis. The network contains 58 countries and 37 activity sectors for years 1995 and 2008. The construction of G, based on Markov chain transitions, treats all countries on equal democratic grounds while the contribution of activity sectors is proportional to their exchange monetary volume. The Google matrix analysis allows to obtain reliable ranking of countries and activity sectors and to determine the sensitivity of CheiRank-PageRank commercial balance of countries in respect to price variations and labor cost in various countries. We demonstrate that the developed approach takes into account multiplicity of network links with economy interactions between countries and activity sectors thus being more efficient compared to the usual export-import analysis. The spectrum and eigenstates of G are also analyzed being related to specific activity communities of countries.

  13. Organic Light-Emitting Devices (OLEDS) and Their Optically Detected Magnetic Resonance (ODMR)

    SciTech Connect

    Li, Gang

    2003-01-01

    Organic Light-Emitting Devices (OLEDs), both small molecular and polymeric have been studied extensively since the first efficient small molecule OLED was reported by Tang and VanSlyke in 1987. Burroughes' report on conjugated polymer-based OLEDs led to another track in OLED development. These developments have resulted in full color, highly efficient (up to {approx} 20% external efficiency 60 lm/W power efficiency for green emitters), and highly bright (> 140,000 Cd/m{sup 2} DC, {approx}2,000,000 Cd/m{sup 2} AC), stable (>40,000 hr at 5 mA/cm{sup 2}) devices. OLEDs are Lambertian emitters, which intrinsically eliminates the view angle problem of liquid crystal displays (LCDs). Thus OLEDs are beginning to compete with the current dominant LCDs in information display. Numerous companies are now active in this field, including large companies such as Pioneer, Toyota, Estman Kodak, Philipps, DuPont, Samsung, Sony, Toshiba, and Osram, and small companies like Cambridge Display Technology (CDT), Universal Display Corporation (UDC), and eMagin. The first small molecular display for vehicular stereos was introduced in 1998, and polymer OLED displays have begun to appear in commercial products. Although displays are the major application for OLEDs at present, they are also candidates for nest generation solid-state lighting. In this case the light source needs to be white in most cases. Organic transistors, organic solar cells, etc. are also being developed vigorously.

  14. Development of functional nano-particle layer for highly efficient OLED

    NASA Astrophysics Data System (ADS)

    Lee, Jae-Hyun; Kim, Min-Hoi; Choi, Haechul; Choi, Yoonseuk

    2015-12-01

    Organic light emitting diodes (OLEDs) are now widely commercialized in market due to many advantages such as possibility of making thin or flexible devices. Nevertheless there are still several things to obtain the high quality flexible OLEDs, one of the most important issues is the light extraction of the device. It is known that OLEDs have the typical light loss such as the waveguide loss, plasmon absorption loss and internal total reflection. In this paper, we demonstrate the one-step processed light scattering films with aluminum oxide nano-particles and polystyrene matrix composite to achieve highly efficient OLEDs. Optical characteristics and surface roughness of light scattering film was optimized by changing the mixing concentration of Al2O3 nano-particles and investigated with the atomic force microscopy and hazemeter, respectively.

  15. Evidence that the Yeast Desaturase Ole1p Exists as a Dimer In Vivo

    SciTech Connect

    Lou, Y.; Shanklin, J.

    2010-06-18

    Desaturase enzymes are composed of two classes, the structurally well characterized soluble class found predominantly in the plastids of higher plants and the more widely distributed but poorly structurally defined integral membrane class. Despite their distinct evolutionary origins, the two classes both require an iron cofactor and molecular oxygen for activity and are inhibited by azide and cyanide, suggesting strong mechanistic similarities. The fact that the soluble desaturase is active as a homodimer prompted us test the hypothesis that an archetypal integral membrane desaturase from Saccharomyces cerevisiae, the {Delta}{sup o}-acyl-Co-A desaturase Ole1p, also exhibits a dimeric organization. Ole1p was chosen because it is one of the best characterized integral membrane desaturase and because it retains activity when fused with epitope tags. FLAG-Ole1p was detected by Western blotting of immunoprecipitates in which anti-Myc antibodies were used for capture from yeast extracts co-expressing Ole1p-Myc and Ole1p-FLAG. Interaction was confirmed by two independent bimolecular complementation assays (i.e. the split ubiquitin system and the split luciferase system). Co-expression of active and inactive Ole1p subunits resulted in an {approx}75% suppression of the accumulation of palmitoleic acid, demonstrating that the physiologically active form of Ole1p in vivo is the dimer in which both protomers must be functional.

  16. OLED emission zone measurement with high accuracy

    NASA Astrophysics Data System (ADS)

    Danz, N.; MacCiarnain, R.; Michaelis, D.; Wehlus, T.; Rausch, A. F.; Wächter, C. A.; Reusch, T. C. G.

    2013-09-01

    Highly efficient state of the art organic light-emitting diodes (OLED) comprise thin emitting layers with thicknesses in the order of 10 nm. The spatial distribution of the photon generation rate, i.e. the profile of the emission zone, inside these layers is of interest for both device efficiency analysis and characterization of charge recombination processes. It can be accessed experimentally by reverse simulation of far-field emission pattern measurements. Such a far-field pattern is the sum of individual emission patterns associated with the corresponding positions inside the active layer. Based on rigorous electromagnetic theory the relation between far-field pattern and emission zone is modeled as a linear problem. This enables a mathematical analysis to be applied to the cases of single and double emitting layers in the OLED stack as well as to pattern measurements in air or inside the substrate. From the results, guidelines for optimum emitter - cathode separation and for selecting the best experimental approach are obtained. Limits for the maximum spatial resolution can be derived.

  17. Full-color OLED on silicon microdisplay

    NASA Astrophysics Data System (ADS)

    Ghosh, Amalkumar P.

    2002-02-01

    eMagin has developed numerous enhancements to organic light emitting diode (OLED) technology, including a unique, up- emitting structure for OLED-on-silicon microdisplay devices. Recently, eMagin has fabricated full color SVGA+ resolution OLED microdisplays on silicon, with over 1.5 million color elements. The display is based on white light emission from OLED followed by LCD-type red, green and blue color filters. The color filters are patterned directly on OLED devices following suitable thin film encapsulation and the drive circuits are built directly on single crystal silicon. The resultant color OLED technology, with hits high efficiency, high brightness, and low power consumption, is ideally suited for near to the eye applications such as wearable PCS, wireless Internet applications and mobile phone, portable DVD viewers, digital cameras and other emerging applications.

  18. OleD Loki as a Catalyst for Tertiary Amine and Hydroxamate Glycosylation.

    PubMed

    Hughes, Ryan R; Shaaban, Khaled A; Zhang, Jianjun; Cao, Hongnan; Phillips, George N; Thorson, Jon S

    2017-02-16

    We describe the ability of an engineered glycosyltransferase (OleD Loki) to catalyze the N-glycosylation of tertiary-amine-containing drugs and trichostatin hydroxamate glycosyl ester formation. As such, this study highlights the first bacterial model catalyst for tertiary-amine N-glycosylation and further expands the substrate scope and synthetic potential of engineered OleDs. In addition, this work could open the door to the discovery of similar capabilities among other permissive bacterial glycosyltransferases.

  19. Solid State Lighting OLED Manufacturing Roundtable Summary

    SciTech Connect

    none,

    2010-03-31

    Summary of a meeting of OLED experts to develop proposed priority tasks for the Manufacturing R&D initiative, including task descriptions, discussion points, recommendations, and presentation highlights.

  20. Series connected OLED structure and fabrication method

    SciTech Connect

    Foust, Donald Franklin; Balch, Ernest Wayne; Duggal, Anil Raj; Heller, Christian Maria; Guida, Renato; Nealon, William Francis; Faircloth, Tami Janene

    2006-05-23

    A light emitting device comprises a plurality of organic light emitting diode (OLED) modules. The OLED modules are arranged into a series group where the individual OLED modules are electrically connected in series. The device is configured to be coupled to a power supply. A display is also provided. The display includes a plurality of OLED modules arranged to depict a shape selected from the group consisting of at least one letter, at least one number, at least one image, and a combination thereof.

  1. Jet-Printed Active-Matrix Backplanes and Electrophoretic Displays

    NASA Astrophysics Data System (ADS)

    Daniel, Jurgen; Arias, Ana Claudia; Wong, William; Lujan, Rene; Ready, Steve; Krusor, Brent; Street, Robert

    2007-03-01

    The fabrication of large-area electronics, such as active-matrix pixel circuits in flat-panel displays, is becoming increasingly challenging. Particularly for applications such as electronic paper, flexibility of the display and fabrication at extremely low cost is important. Therefore, novel fabrication methods have to be explored. We have developed jet-printing technology to fabricate active-matrix backplanes for paper-like electrophoretic displays. In three approaches we implement several stages of evolution of the printing technology. First, the photolithographic patterning of photoresist used in conventional fabrication is replaced by digital printing of a wax etch mask. Second, the amorphous silicon semiconductor for the thin-film-transistors is replaced with a printed organic semiconductor. Third, the active-matrix pixel circuit is fabricated in an all-additive printing process. In order to test our backplanes we are developing electrophoretic display media. The media is based on microfabricated cell-structures which contain the electrophoretic ink. Particularly for flexible displays, the cells have to be individually sealed and several methods are being explored.

  2. Platelet activation by extracellular matrix proteins in haemostasis and thrombosis.

    PubMed

    Watson, Steve P

    2009-01-01

    The prevention of excessive blood loss to avoid fatal haemorrhage is a pivotal process for all organisms possessing a circulatory system. Increased circulating blood volume and pressure, as required in larger animals, make this process all the more important and challenging. It is essential to have a powerful and rapid system to detect damage and generate an effective seal, and which is also exquisitely regulated to prevent unwanted, excessive or systemic activation so as to avoid blockage of vessels. Thus, a highly specialised and efficient haemostatic system has evolved that consists of cellular (platelets) and protein (coagulation factors) components. Importantly, this is able to support haemostasis in both the low shear environment of the venous system and the high shear environment of the arterial system. Endothelial cells, lining the entire circulation system, play a crucial role in the delicate balance between activation and inhibition of the haemostatic system. An intact and healthy endothelium supports blood flow by preventing attachment of cells and proteins which is required for initiation of coagulation and platelet activation. Endothelial cells produce and release the two powerful soluble inhibitors of platelet activation, nitric oxide and prostacyclin, and express high levels of CD39 which rapidly metabolises the major platelet feedback agonist, ADP. This antithrombotic environment however can rapidly change following activation or removal of endothelial cells through injury or rupture of atherosclerotic plaques. Loss of endothelial cells exposes the subendothelial extracellular matrix which creates strong signals for activation of the haemostatic system including powerful platelet adhesion and activation. Quantitative and qualitative changes in the composition of the subendothelial extracellular matrix influence these prothrombotic characteristics with life threatening thrombotic and bleeding complications, as illustrated by formation of

  3. On the role of polar molecules and the barrier for charge injection in OLEDs

    NASA Astrophysics Data System (ADS)

    Altazin, S.; Züfle, S.; Knapp, E.; Kirsch, C.; Schmidt, T. D.; Jäger, L.; Brütting, W.; Ruhstaller, B.

    2016-09-01

    Many electron transport layer materials (ETL) employed in state of the art organic light emitting diodes (OLEDs) are known to be polar. We combine for the first time simulations and electrical characterization of OLEDs based on polar ETL, in order to understand the impact of such materials on the device operation. Depending on the orientation of the dipole orientation, simulations predict either a benefit or a disadvantage of the polar ETL for the device performance. We also show that OLEDs featuring a polar material are perfectly suited for extracting mobility activation energy and Injection barrier from the anode to the ETL.

  4. Recent progress in flexible OLED displays

    NASA Astrophysics Data System (ADS)

    Hack, Michael G.; Weaver, Michael S.; Mahon, Janice K.; Brown, Julie J.

    2001-09-01

    Organic light emitting device (OLED) technology has recently been shown to demonstrate excellent performance and cost characteristics for use in numerous flat panel display (FPD) applications. OLED displays emit bright, colorful light with excellent power efficiency, wide viewing angle and video response rates. OLEDs are also demonstrating the requisite environmental robustness for a wide variety of applications. OLED technology is also the first FPD technology with the potential to be highly functional and durable in a flexible format. The use of plastic and other flexible substrate materials offers numerous advantages over commonly used glass substrates, including impact resistance, light weight, thinness and conformability. Currently, OLED displays are being fabricated on rigid substrates, such as glass or silicon wafers. At Universal Display Corporation (UDC), we are developing a new class of flexible OLED displays (FOLEDs). These displays also have extremely low power consumption through the use of electrophosphorescent doped OLEDs. To commercialize FOLED technology, a number of technical issues related to packaging and display processing on flexible substrates need to be addressed. In this paper, we report on our recent results to demonstrate the key technologies that enable the manufacture of power efficient, long-life flexible OLED displays for commercial and military applications.

  5. Surface activity as a crucial factor of the biological actions of Ole e 1, the main aeroallergen of olive tree (Olea europaea) pollen.

    PubMed

    Lopez-Rodriguez, Juan Carlos; Barderas, Rodrigo; Echaide, Mercedes; Perez-Gil, Jesus; Villalba, Mayte; Batanero, Eva; Cruz, Antonio

    2016-10-10

    Aeroallergens are airborne substances -mainly proteins- capable of triggering Th2-immune responses in respiratory allergies. They enter into the body through the upper airways, reaching the mucosa afterwards. Mucosae lining at the luminal side consists of an epithelial barrier completely covered by mucus and pulmonary surfactant. Both, pulmonary surfactant and plasma membrane of the epithelial cells represent two physiological phospholipid-based barriers where allergens first impact before triggering their biological effects. The interaction of allergens with lipids at relevant physiological surfaces could promote structural changes on the molecule, resulting on a potential modification of its allergenic properties. In this work, we have firstly described the surface and phospholipid interaction capabilities of the clinically relevant aeroallergen Ole e 1, the main allergen of olive tree pollen. By using epifluorescence microscopy of Langmuir transferred films, we observed that lipid-packed ordered domains may function as a preferential location for allergen to accumulate at the air-liquid interface, an effect that is abolished in the presence of cholestenone. The possible implications of phospholipid-interfacial effects in the modification of allergen structural and functional properties will be discussed.

  6. Electrochemical Proteolytic Beacon for Detection of Matrix Metalloproteinase Activities

    SciTech Connect

    Liu, Guodong; Wang, Jun; Wunschel, David S.; Lin, Yuehe

    2006-09-27

    This communication describes a novel method for detecting of matrix metalloproteinase-7 activity using a peptide substrate labeled with a ferrocene reporter. The substrate serves as a selective ‘electrochemical proteolytic beacon’ (EPB) for this metalloproteinase. The EPB is immobilized on a gold electrode surface to enable ‘on-off’ electrochemical signaling capability for uncleaved and cleaved events. The EPB is efficiently and selectively cleaved by MMP-7 as measured by the rate of decrease in redox current of ferrocene. Direct transduction of a signal corresponding to peptide cleavage events into an electronic signal thus provides a simple, sensitive route for detecting the MMP activity. The new method allows for identification of the activity of MMP-7 in concentrations as low as 3.4 pM. The concept can be extended to design multiple peptide substrate labeled with different electroactive reporters for assaying multiple MMPs activities.

  7. Modeling mechanophore activation within a crosslinked glassy matrix

    NASA Astrophysics Data System (ADS)

    Silberstein, Meredith N.; Min, Kyoungmin; Cremar, Lee D.; Degen, Cassandra M.; Martinez, Todd J.; Aluru, Narayana R.; White, Scott R.; Sottos, Nancy R.

    2013-07-01

    Mechanically induced reactivity is a promising means for designing self-reporting materials. Mechanically sensitive chemical groups called mechanophores are covalently linked into polymers in order to trigger specific chemical reactions upon mechanical loading. These mechanophores can be linked either within the backbone or as crosslinks between backbone segments. Mechanophore response is sensitive to both the matrix properties and placement within the matrix, providing two avenues for material design. A model framework is developed to describe reactivity of mechanophores located as crosslinks in a glassy polymer matrix. Simulations are conducted at the molecular and macromolecular scales in order to develop macroscale constitutive relations. The model is developed specifically for the case of spiropyran (SP) in lightly crosslinked polymethylmethacrylate (PMMA). This optically trackable mechanophore (fluorescent when activated) allows the model to be assessed in terms of observed experimental behavior. The force modified potential energy surface (FMPES) framework is used in conjunction with ab initio steered molecular dynamics (MD) simulations of SP to determine the mechanophore kinetics. MD simulations of the crosslinked PMMA structure under shear deformation are used to determine the relationship between macroscale stress and local force on the crosslinks. A continuum model implemented in a finite element framework synthesizes these mechanochemical relations with the mechanical behavior. The continuum model with parameters taken directly from the FMPES and MD analyses under predicts stress-driven activation relative to experimental data. The continuum model, with the physically motivated modification of force fluctuations, provides an accurate prediction for monotonic loading across three decades of strain rate and creep loading, suggesting that the fundamental physics are captured.

  8. Purification and Characterization of OleA from Xanthomonas campestris and Demonstration of a Non-decarboxylative Claisen Condensation Reaction

    SciTech Connect

    Frias, JA; Richman, JE; Erickson, JS; Wackett, LP

    2011-03-25

    OleA catalyzes the condensation of fatty acyl groups in the first step of bacterial long-chain olefin biosynthesis, but the mechanism of the condensation reaction is controversial. In this study, OleA from Xanthomonas campestris was expressed in Escherichia coli and purified to homogeneity. The purified protein was shown to be active with fatty acyl-CoA substrates that ranged from C(8) to C(16) in length. With limiting myristoyl-CoA (C(14)), 1 mol of the free coenzyme A was released/mol of myristoyl-CoA consumed. Using [(14)C] myristoyl-CoA, the other products were identified as myristic acid, 2-myristoylmyristic acid, and 14-heptacosanone. 2-Myristoylmyristic acid was indicated to be the physiologically relevant product of OleA in several ways. First, 2-myristoylmyristic acid was the major condensed product in short incubations, but over time, it decreased with the concomitant increase of 14-heptacosanone. Second, synthetic 2-myristoylmyristic acid showed similar decarboxylation kinetics in the absence of OleA. Third, 2-myristoylmyristic acid was shown to be reactive with purified OleC and OleD to generate the olefin 14-heptacosene, a product seen in previous in vivo studies. The decarboxylation product, 14-heptacosanone, did not react with OleC and OleD to produce any demonstrable product. Substantial hydrolysis of fatty acyl-CoA substrates to the corresponding fatty acids was observed, but it is currently unclear if this occurs in vivo. In total, these data are consistent with OleA catalyzing a non-decarboxylative Claisen condensation reaction in the first step of the olefin biosynthetic pathway previously found to be present in at least 70 different bacterial strains.

  9. Ramiprilate inhibits functional matrix metalloproteinase activity in Crohn's disease fistulas.

    PubMed

    Efsen, Eva; Saermark, Torben; Hansen, Alastair; Bruun, Eywin; Brynskov, Jørn

    2011-09-01

    Increased expression of matrix metalloproteinase (MMP)-2, -3 and -9 has been demonstrated in Crohn's disease fistulas, but it is unknown whether these enzymes are biologically active and represent a therapeutic target. Therefore, we investigated the proteolytic activity of MMPs in fistula tissue and examined the effect of inhibitors, including clinically available drugs that beside their main action also suppress MMPs. Fistula specimens were obtained by surgical excision from 22 patients with Crohn's disease and from 10 patients with fistulas resulting from other causes. Colonic endoscopic biopsies from six controls were also included. Total functional MMP activity was measured by a high-pressure liquid chromatography (HPLC)-based, fluorogenic MMP-substrate cleavage assay, and the specific activity of MMP-2, -3 and -9 by the MMP Biotrak Activity Assay. The MMP inhibitors comprised ethylene-diamine-tetraacetic acid (EDTA), the synthetic broad-spectrum inhibitor, GM6001, the angiotensin-converting enzyme (ACE) inhibitor, ramiprilate, and the tetracycline, doxycycline. In Crohn's disease fistulas, about 50% of the total protease activity was attributable to MMP activity. The average total MMP activity was significantly higher (about 3.5-times) in Crohn's fistulas (471 FU/μg protein, range 49-2661) compared with non-Crohn's fistulas [134 FU/μg protein, range 0-495, (p < 0.05)] and normal colon [153 FU/μg protein, range 77-243, (p < 0.01)]. MMP-3 activity was increased in Crohn's fistulas (1.4 ng/ml, range 0-9.83) compared with non-Crohn's fistulas, [0.32 ng/ml, range 0-2.66, (p < 0.02)]. The same applied to MMP-9 activity [0.64 ng/ml, range 0-5.66 and 0.17 ng/ml, range 0-1.1, respectively (p < 0.04)]. Ramiprilate significantly decreased the average total MMP activity level by 42% and suppressed the specific MMP-3 activity by 72%, which is comparable to the effect of GM6001 (87%). Moreover, MMP-9 activity was completely blunted by ramiprilate. Doxycycline had no

  10. Residual matrix from different separation techniques impacts exosome biological activity

    PubMed Central

    Paolini, Lucia; Zendrini, Andrea; Noto, Giuseppe Di; Busatto, Sara; Lottini, Elisabetta; Radeghieri, Annalisa; Dossi, Alessandra; Caneschi, Andrea; Ricotta, Doris; Bergese, Paolo

    2016-01-01

    Exosomes are gaining a prominent role in research due to their intriguing biology and several therapeutic opportunities. However, their accurate purification from body fluids and detailed physicochemical characterization remain open issues. We isolated exosomes from serum of patients with Multiple Myeloma by four of the most popular purification methods and assessed the presence of residual contaminants in the preparations through an ad hoc combination of biochemical and biophysical techniques - including Western Blot, colloidal nanoplasmonics, atomic force microscopy (AFM) and scanning helium ion microscopy (HIM). The preparations obtained by iodixanol and sucrose gradients were highly pure. To the contrary, those achieved with limited processing (serial centrifugation or one step precipitation kit) resulted contaminated by a residual matrix, embedding the exosomes. The contaminated preparations showed lower ability to induce NfkB nuclear translocation in endothelial cells with respect to the pure ones, probably because the matrix prevents the interaction and fusion of the exosomes with the cell membrane. These findings suggest that exosome preparation purity must be carefully assessed since it may interfere with exosome biological activity. Contaminants can be reliably probed only by an integrated characterization approach aimed at both the molecular and the colloidal length scales. PMID:27009329

  11. Host compounds for red phosphorescent OLEDs

    DOEpatents

    Xia, Chuanjun; Cheon, Kwang -Ohk

    2015-08-25

    Novel compounds containing a triphenylene moiety linked to an .alpha..beta. connected binaphthyl ring system are provided. These compounds have surprisingly good solubility in organic solvents and are useful as host compounds in red phosphorescent OLEDs.

  12. Catalytic Determinants of Alkene Production by the Cytochrome P450 Peroxygenase OleTJE*

    PubMed Central

    Matthews, Sarah; Belcher, James D.; Tee, Kang Lan; Girvan, Hazel M.; McLean, Kirsty J.; Rigby, Stephen E. J.; Levy, Colin W.; Leys, David; Parker, David A.; Blankley, Richard T.; Munro, Andrew W.

    2017-01-01

    The Jeotgalicoccus sp. peroxygenase cytochrome P450 OleTJE (CYP152L1) is a hydrogen peroxide-driven oxidase that catalyzes oxidative decarboxylation of fatty acids, producing terminal alkenes with applications as fine chemicals and biofuels. Understanding mechanisms that favor decarboxylation over fatty acid hydroxylation in OleTJE could enable protein engineering to improve catalysis or to introduce decarboxylation activity into P450s with different substrate preferences. In this manuscript, we have focused on OleTJE active site residues Phe79, His85, and Arg245 to interrogate their roles in substrate binding and catalytic activity. His85 is a potential proton donor to reactive iron-oxo species during substrate decarboxylation. The H85Q mutant substitutes a glutamine found in several peroxygenases that favor fatty acid hydroxylation. H85Q OleTJE still favors alkene production, suggesting alternative protonation mechanisms. However, the mutant undergoes only minor substrate binding-induced heme iron spin state shift toward high spin by comparison with WT OleTJE, indicating the key role of His85 in this process. Phe79 interacts with His85, and Phe79 mutants showed diminished affinity for shorter chain (C10–C16) fatty acids and weak substrate-induced high spin conversion. F79A OleTJE is least affected in substrate oxidation, whereas the F79W/Y mutants exhibit lower stability and cysteine thiolate protonation on reduction. Finally, Arg245 is crucial for binding the substrate carboxylate, and R245E/L mutations severely compromise activity and heme content, although alkene products are formed from some substrates, including stearic acid (C18:0). The results identify crucial roles for the active site amino acid trio in determining OleTJE catalytic efficiency in alkene production and in regulating protein stability, heme iron coordination, and spin state. PMID:28053093

  13. Catalytic Determinants of Alkene Production by the Cytochrome P450 Peroxygenase OleTJE.

    PubMed

    Matthews, Sarah; Belcher, James D; Tee, Kang Lan; Girvan, Hazel M; McLean, Kirsty J; Rigby, Stephen E J; Levy, Colin W; Leys, David; Parker, David A; Blankley, Richard T; Munro, Andrew W

    2017-03-24

    The Jeotgalicoccus sp. peroxygenase cytochrome P450 OleTJE (CYP152L1) is a hydrogen peroxide-driven oxidase that catalyzes oxidative decarboxylation of fatty acids, producing terminal alkenes with applications as fine chemicals and biofuels. Understanding mechanisms that favor decarboxylation over fatty acid hydroxylation in OleTJE could enable protein engineering to improve catalysis or to introduce decarboxylation activity into P450s with different substrate preferences. In this manuscript, we have focused on OleTJE active site residues Phe(79), His(85), and Arg(245) to interrogate their roles in substrate binding and catalytic activity. His(85) is a potential proton donor to reactive iron-oxo species during substrate decarboxylation. The H85Q mutant substitutes a glutamine found in several peroxygenases that favor fatty acid hydroxylation. H85Q OleTJE still favors alkene production, suggesting alternative protonation mechanisms. However, the mutant undergoes only minor substrate binding-induced heme iron spin state shift toward high spin by comparison with WT OleTJE, indicating the key role of His(85) in this process. Phe(79) interacts with His(85), and Phe(79) mutants showed diminished affinity for shorter chain (C10-C16) fatty acids and weak substrate-induced high spin conversion. F79A OleTJE is least affected in substrate oxidation, whereas the F79W/Y mutants exhibit lower stability and cysteine thiolate protonation on reduction. Finally, Arg(245) is crucial for binding the substrate carboxylate, and R245E/L mutations severely compromise activity and heme content, although alkene products are formed from some substrates, including stearic acid (C18:0). The results identify crucial roles for the active site amino acid trio in determining OleTJE catalytic efficiency in alkene production and in regulating protein stability, heme iron coordination, and spin state.

  14. OLED microdisplay design and materials

    NASA Astrophysics Data System (ADS)

    Wacyk, Ihor; Prache, Olivier; Ali, Tariq; Khayrullin, Ilyas; Ghosh, Amalkumar

    2010-04-01

    AMOLED microdisplays from eMagin Corporation are finding growing acceptance within the military display market as a result of their excellent power efficiency, wide operating temperature range, small size and weight, good system flexibility, and ease of use. The latest designs have also demonstrated improved optical performance including better uniformity, contrast, MTF, and color gamut. eMagin's largest format display is currently the SXGA design, which includes features such as a 30-bit wide RGB digital interface, automatic luminance regulation from -45 to +70°C, variable gamma control, and a dynamic range exceeding 50:000 to 1. This paper will highlight the benefits of eMagin's latest microdisplay designs and review the roadmap for next generation devices. The ongoing development of reduced size pixels and larger format displays (up to WUXGA) as well as new OLED device architecture (e.g. high-brightness yellow) will be discussed. Approaches being explored for improved performance in next generation designs such as lowpower serial interfaces, high frame rate operation, and new operational modes for reduction of motion artifacts will also be described. These developments should continue to enhance the appeal of AMOLED microdisplays for a broad spectrum of near-to-the-eye applications such as night vision, simulation and training, situational awareness, augmented reality, medical imaging, and mobile video entertainment and gaming.

  15. OLED devices with internal outcoupling

    DOEpatents

    Liu, Jr., Jie Jerry; Sista, Srinivas Prasad; Shi, Xiaolei; Zhao, Ri-An; Chichak, Kelly Scott; Youmans, Jeffrey Michael; Janora, Kevin Henry; Turner, Larry Gene

    2016-12-06

    Optoelectronic devices with enhanced internal outcoupling include a substrate, an anode, a cathode, an electroluminescent layer, and an electron transporting layer comprising inorganic nanoparticles dispersed in an organic matrix.

  16. Readability evaluation of an active matrix electrophoric ink display

    NASA Astrophysics Data System (ADS)

    Meyer, Frederick M.; Trissell, Terry L.; Aleva, Denise L.; Longo, Sam J.; Hopper, Darrel G.

    2006-05-01

    A low-power, yet sunlight readable, display is needed for dismounted applications where the user must carry the power source. Such a display could potentially replace paper checklists and maps with electronic counterparts. A reflective active matrix electrophoretic ink display (AMEPID) was evaluated as a candidate technology for such applications. This display technology uses ambient illumination, rather than competing with it, and requires power only when rewriting the display. The device was tested for viewability under a variety of lighting conditions. Readability of displayed text, as compared to standard print on white paper, was evaluated in an indoor office environment and in outdoor lighting conditions. Viewability of the display with night vision goggles (NVGs) was evaluated under simulated full moon, starlight, and overcast illumination conditions. Objective measurements of luminance, contrast ratio and reflectance were conducted under corresponding irradiance conditions and viewing angles using state-of-the-art photometric and radiometric measurement equipment. In addition to visible spectrum measurements, infrared (IR) reflectance and contrast were measured for the extended spectrum of 720-1700 nm. Results are discussed in terms of performance criteria for military displays, which are often much more demanding than for civil applications.

  17. Matrix Metalloproteinase 9 Exerts Antiviral Activity against Respiratory Syncytial Virus

    PubMed Central

    Dabo, Abdoulaye J.; Cummins, Neville; Eden, Edward; Geraghty, Patrick

    2015-01-01

    Increased lung levels of matrix metalloproteinase 9 (MMP9) are frequently observed during respiratory syncytial virus (RSV) infection and elevated MMP9 concentrations are associated with severe disease. However little is known of the functional role of MMP9 during lung infection with RSV. To determine whether MMP9 exerted direct antiviral potential, active MMP9 was incubated with RSV, which showed that MMP9 directly prevented RSV infectivity to airway epithelial cells. Using knockout mice the effect of the loss of Mmp9 expression was examined during RSV infection to demonstrate MMP9’s role in viral clearance and disease progression. Seven days following RSV infection, Mmp9-/- mice displayed substantial weight loss, increased RSV-induced airway hyperresponsiveness (AHR) and reduced clearance of RSV from the lungs compared to wild type mice. Although total bronchoalveolar lavage fluid (BALF) cell counts were similar in both groups, neutrophil recruitment to the lungs during RSV infection was significantly reduced in Mmp9-/- mice. Reduced neutrophil recruitment coincided with diminished RANTES, IL-1β, SCF, G-CSF expression and p38 phosphorylation. Induction of p38 signaling was required for RANTES and G-CSF expression during RSV infection in airway epithelial cells. Therefore, MMP9 in RSV lung infection significantly enhances neutrophil recruitment, cytokine production and viral clearance while reducing AHR. PMID:26284919

  18. Monolithic Active Pixel Matrix with Binary Counters (MAMBO) ASIC

    SciTech Connect

    Khalid, Farah F.; Deptuch, Grzegorz; Shenai, Alpana; Yarema, Raymond J.; /Fermilab

    2010-11-01

    Monolithic Active Matrix with Binary Counters (MAMBO) is a counting ASIC designed for detecting and measuring low energy X-rays from 6-12 keV. Each pixel contains analogue functionality implemented with a charge preamplifier, CR-RC{sup 2} shaper and a baseline restorer. It also contains a window comparator which can be trimmed by 4 bit DACs to remove systematic offsets. The hits are registered by a 12 bit ripple counter which is reconfigured as a shift register to serially output the data from the entire ASIC. Each pixel can be tested individually. Two diverse approaches have been used to prevent coupling between the detector and electronics in MAMBO III and MAMBO IV. MAMBO III is a 3D ASIC, the bottom ASIC consists of diodes which are connected to the top ASIC using {mu}-bump bonds. The detector is decoupled from the electronics by physically separating them on two tiers and using several metal layers as a shield. MAMBO IV is a monolithic structure which uses a nested well approach to isolate the detector from the electronics. The ASICs are being fabricated using the SOI 0.2 {micro}m OKI process, MAMBO III is 3D bonded at T-Micro and MAMBO IV nested well structure was developed in collaboration between OKI and Fermilab.

  19. Monolithic active pixel matrix with binary counters (MAMBO III) ASIC

    SciTech Connect

    Khalid, Farah; Deptuch, Grzegorz; Shenai, Alpana; Yarema, Raymond; /Fermilab

    2010-01-01

    Monolithic Active Matrix with Binary Counters (MAMBO) is a counting ASIC designed for detecting and measuring low energy X-rays from 6-12keV. Each pixel contains analogue functionality implemented with a charge preamplifier, CR-RC{sup 2} shaper and a baseline restorer. It also contains a window comparator which can be trimmed by 4 bit DACs to remove systematic offsets. The hits are registered by a 12 bit ripple counter which is reconfigured as a shift register to serially output the data from the entire ASIC. Each pixel can be tested individually. Two diverse approaches have been used to prevent coupling between the detector and electronics in MAMBO III and MAMBO IV. MAMBO III is a 3D ASIC, the bottom ASIC consists of diodes which are connected to the top ASIC using {mu}-bump bonds. The detector is decoupled from the electronics by physically separating them on two tiers and using several metal layers as a shield. MAMBO IV is a monolithic structure which uses a nested well approach to isolate the detector from the electronics. The ASICs are being fabricated using the SOI 0.2 {micro}m OKI process, MAMBO III is 3D bonded at T-Micro and MAMBO IV nested well structure was developed in collaboration between OKI and Fermilab.

  20. Computational study of bindings of olive leaf extract (OLE) to HIV-1 fusion protein gp41.

    PubMed

    Bao, J; Zhang, D W; Zhang, J Z H; Huang, P Lee; Huang, P Lin; Lee-Huang, S

    2007-06-12

    Recent experimental study found that OLE (olive leaf extract) has anti-HIV activity by blocking the HIV virus entry to host cells [Lee-Huang, S., Zhang, L., Huang, P.L., Chang, Y. and Huang, P.L. (2003) Anti-HIV activity of olive leaf extract (OLE) and modulation of host cell gene expression by HIV-1 infection and OLE treatment. Biochem. Biophys. Res. Commun. 307, 1029; Lee-Huang, S., Huang, P.L., Zhang, D., Lee, J.W., Bao, J., Sun, Y., Chang, Y.-Tae, Zhang, J.Z.H. and Huang, P.L. (2007) Discovery of small-molecule HIV-1 fusion and integrase inhibitors oleuropein and hydroxytyrosol. Biochem. Biophys. Res. Commun. 354, 872-878, 879-884]. As part of a joint experimental and theoretical effort, we report here computational study to help identify and characterize the binding complexes of several main compounds of OLE (olive leaf extract) to HIV-1 envelop protein gp41. A number of possible binding modes are found by docking oleuropein and its metabolites, aglycone, elenolic acid and hydroxytyrosol, onto the hydrophobic pocket on gp41. Detailed OLE-gp41 binding interactions and free energies of binding are obtained through molecular dynamics simulation and MM-PBSA calculation. Specific molecular interactions in our predicted OLE/gp41 complexes are identified and hydroxytyrosol is identified to be the main moiety for binding to gp41. This computational study complements the corresponding experimental investigation and helps establish a good starting point for further refinement of OLE-based gp41 inhibitors.

  1. Collagenolytic Matrix Metalloproteinase Activities toward Peptomeric Triple-Helical Substrates.

    PubMed

    Stawikowski, Maciej J; Stawikowska, Roma; Fields, Gregg B

    2015-05-19

    Although collagenolytic matrix metalloproteinases (MMPs) possess common domain organizations, there are subtle differences in their processing of collagenous triple-helical substrates. In this study, we have incorporated peptoid residues into collagen model triple-helical peptides and examined MMP activities toward these peptomeric chimeras. Several different peptoid residues were incorporated into triple-helical substrates at subsites P3, P1, P1', and P10' individually or in combination, and the effects of the peptoid residues were evaluated on the activities of full-length MMP-1, MMP-8, MMP-13, and MMP-14/MT1-MMP. Most peptomers showed little discrimination between MMPs. However, a peptomer containing N-methyl Gly (sarcosine) in the P1' subsite and N-isobutyl Gly (NLeu) in the P10' subsite was hydrolyzed efficiently only by MMP-13 [nomenclature relative to the α1(I)772-786 sequence]. Cleavage site analysis showed hydrolysis at the Gly-Gln bond, indicating a shifted binding of the triple helix compared to the parent sequence. Favorable hydrolysis by MMP-13 was not due to sequence specificity or instability of the substrate triple helix but rather was based on the specific interactions of the P7' peptoid residue with the MMP-13 hemopexin-like domain. A fluorescence resonance energy transfer triple-helical peptomer was constructed and found to be readily processed by MMP-13, not cleaved by MMP-1 and MMP-8, and weakly hydrolyzed by MT1-MMP. The influence of the triple-helical structure containing peptoid residues on the interaction between MMP subsites and individual substrate residues may provide additional information about the mechanism of collagenolysis, the understanding of collagen specificity, and the design of selective MMP probes.

  2. Blue-hazard-free Candlelight OLED.

    PubMed

    Jou, Jwo-Huei; Singh, Meenu; Su, Yu-Ting; Liu, Shih-Hao; He, Zhe-Kai

    2017-03-19

    A candlelight-style organic light emitting diode (OLED) is a human-friendly type of lighting because it is blue-hazard-free and has a low correlated color temperature (CCT) illumination. The low CCT lighting is deprived of high-energy blue radiation, and it can be used for a longer duration before causing retinal damage. This work presents the comprehensive protocols for the fabrication of blue-hazard-free candlelight OLEDs. The emission spectrum of the OLED was characterized by the maximum exposure time limit of the retina and the melatonin suppression sensitivity. The devices can be fabricated using dry and wet processes. The dry-processed OLED resulted in a CCT of 1,940 K and exhibited a maximum retinal exposure limit of 1,287 s at a brightness of 500 lx. It showed 2.61% melatonin suppression sensitivity relative to 480 nm blue light. The wet-processed OLED, where the spin coating is used to deposit hole injection, hole transport, and emissive layers, making fabrication fast and economical, produced a CCT of 1,922 K and showed a maximum retinal exposure limit of 7,092 at a brightness of 500 lx. The achieved relative melatonin suppression sensitivity of 1.05% is 86% and 96% less than that of the light emitting diode (LED) and compact fluorescent lamp (CFL), respectively. Wet-processed blue-hazard-free candlelight OLED exhibited a power efficiency of 30 lm/W, which is 2 times that of the incandescent bulb and 300 times that of the candle.

  3. High voltage protection in active matrix flat-panel imagers

    NASA Astrophysics Data System (ADS)

    Lehnert, Joerg; Zhao, Wei

    2006-03-01

    Various direct and indirect active matrix flat-panel imagers (AMFPI) are being investigated for x-ray imaging. In both direct AMFPI and indirect AMFPI with avalanche gain, a bias potential up to several thousand volts is required to operate the photoconductor. Under the condition of a large amount of radiation exposure between subsequent readout, a potential >80 V could appear across the amorphous silicon (a-Si) thin film transistor (TFT) and cause permanent damage. The purpose of this paper is to investigate a simple pixel design for high voltage protection. The pixel electrode acts as an additional gate for the top channel of an a-Si TFT to drain excess image charge from the pixel electrode until an equilibrium is reached where the TFT channel current equals the detector signal current at a predetermined safe maximum value V Pmax for the pixel potential. This "dual-gate" TFT structure without additional protective device simplifies the TFT array design and improves yield. However special care is required to understand the characteristics of both the top and the bottom gates to ensure sufficient detector dynamic range as well as reliable high voltage protection. A physical model for dual-gate a-Si TFTs was developed and device parameters were determined by fitting the model to measured characteristics from a dual-gate TFT array. Our results showed that compared to the bottom (normal) gate, the protective gate has a shallower transfer characteristics (i.e. channel current as a function of gate voltage) due to a higher density of states in the top interface. Nevertheless it provides adequate protection of the TFT with V Pmax of ~40 V for typical radiographic exposures.

  4. OLED devices with internal outcoupling

    DOEpatents

    Liu, Jie Jerry; Sista, Srinivas Prasad; Shi, Xiaolei; Zhao, Ri-An; Chichak, Kelly Scott; Youmans, Jeffrey Michael; Janora, Kevin Henry; Turner, Larry Gene

    2015-03-03

    Optoelectronic devices that have enhanced internal outcoupling are disclosed. The devices include a substrate, an anode, a cathode, an electroluminescent layer, and a hole injecting layer. The hole injecting layer includes inorganic nanoparticles that have a bimodal particle size distribution and which are dispersed in an organic matrix.

  5. High Efficiency, Illumination Quality OLEDs for Lighting

    SciTech Connect

    Joseph Shiang; James Cella; Kelly Chichak; Anil Duggal; Kevin Janora; Chris Heller; Gautam Parthasarathy; Jeffery Youmans; Joseph Shiang

    2008-03-31

    The goal of the program was to demonstrate a 45 lumen per watt white light device based upon the use of multiple emission colors through the use of solution processing. This performance level is a dramatic extension of the team's previous 15 LPW large area illumination device. The fundamental material system was based upon commercial polymer materials. The team was largely able to achieve these goals, and was able to deliver to DOE a 90 lumen illumination source that had an average performance of 34 LPW a 1000 cd/m{sup 2} with peak performances near 40LPW. The average color temperature is 3200K and the calculated CRI 85. The device operated at a brightness of approximately 1000cd/m{sup 2}. The use of multiple emission colors particularly red and blue, provided additional degrees of design flexibility in achieving white light, but also required the use of a multilayered structure to separate the different recombination zones and prevent interconversion of blue emission to red emission. The use of commercial materials had the advantage that improvements by the chemical manufacturers in charge transport efficiency, operating life and material purity could be rapidly incorporated without the expenditure of additional effort. The program was designed to take maximum advantage of the known characteristics of these material and proceeded in seven steps. (1) Identify the most promising materials, (2) assemble them into multi-layer structures to control excitation and transport within the OLED, (3) identify materials development needs that would optimize performance within multilayer structures, (4) build a prototype that demonstrates the potential entitlement of the novel multilayer OLED architecture (5) integrate all of the developments to find the single best materials set to implement the novel multilayer architecture, (6) further optimize the best materials set, (7) make a large area high illumination quality white OLED. A photo of the final deliverable is shown. In

  6. Curved Ferroelectric Liquid Crystal Matrix Displays Driven by Field-Sequential-Color and Active-Matrix Techniques

    NASA Astrophysics Data System (ADS)

    Fujikake, Hideo; Sato, Hiroto; Murashige, Takeshi; Fujisaki, Yoshihide; Kurita, Taiichiro; Furukawa, Tadahiro; Sato, Fumio

    This paper describes a curved field-sequential-color matrix display using fast-response ferroelectric liquid crystal. Black matrix and transparent electrode patterns were formed on a thin plastic substrate by a transfer method from a glass substrate. While a composite film of liquid crystal and micro-polymers of walls and fibers was formed between the flexible substrates by printing, laminating and curing processes of a solution of monomers and liquid crystal, the mechanical stability was enhanced by use of multi-functional monomers to form large display panels. The image pixels of the matrix panel were driven by an active matrix scheme using an external switch transistor array at a frequency of 180 Hz for intermittent three-primary-color backlight illumination. The flexible A4-paper-sized color display with 24 × 16 pixels and 60 Hz field frequency was demonstrated by illuminating it with sequential three-primary-color lights from light-emitting diodes of the backlight. Our display system is useful in various information displays because of its freedom of setting and location.

  7. Donor-acceptor-structured 1,4-diazatriphenylene derivatives exhibiting thermally activated delayed fluorescence: design and synthesis, photophysical properties and OLED characteristics

    NASA Astrophysics Data System (ADS)

    Takahashi, Takehiro; Shizu, Katsuyuki; Yasuda, Takuma; Togashi, Kazunori; Adachi, Chihaya

    2014-06-01

    A new series of luminescent 1,4-diazatriphenylene (ATP) derivatives with various peripheral donor units, including phenoxazine, 9,9-dimethylacridane and 3-(diphenylamino)carbazole, is synthesized and characterized as thermally activated delayed fluorescence (TADF) emitters. The influence of the donor substituents on the electronic and photophysical properties of the materials is investigated by theoretical calculations and experimental spectroscopic measurements. These ATP-based molecules with donor-acceptor-donor (D-A-D) structures can reduce the singlet-triplet energy gap (0.04-0.26 eV) upon chemical modification of the ATP core, and thus exhibit obvious TADF characteristics in solution and doped thin films. As a demonstration of the potential of these materials, organic light-emitting diodes containing the D-A-D-structured ATP derivatives as emitters are fabricated and tested. External electroluminescence quantum efficiencies above 12% and 8% for green- and sky-blue-emitting devices, respectively, are achieved.

  8. Production of alkenes and novel secondary products by P450 OleTJE using novel H2 O2 -generating fusion protein systems.

    PubMed

    Matthews, Sarah; Tee, Kang Lan; Rattray, Nicholas J; McLean, Kirsty J; Leys, David; Parker, David A; Blankley, Richard T; Munro, Andrew W

    2017-03-01

    Jeotgalicoccus sp. 8456 OleTJE (CYP152L1) is a fatty acid decarboxylase cytochrome P450 that uses hydrogen peroxide (H2 O2 ) to catalyse production of terminal alkenes, which are industrially important chemicals with biofuel applications. We report enzyme fusion systems in which Streptomyces coelicolor alditol oxidase (AldO) is linked to OleTJE . AldO oxidizes polyols (including glycerol), generating H2 O2 as a coproduct and facilitating its use for efficient OleTJE -dependent fatty acid decarboxylation. AldO activity is regulatable by polyol substrate titration, enabling control over H2 O2 supply to minimize oxidative inactivation of OleTJE and prolong activity for increased alkene production. We also use these fusion systems to generate novel products from secondary turnover of 2-OH and 3-OH myristic acid primary products, expanding the catalytic repertoire of OleTJE .

  9. Donor–acceptor-structured 1,4-diazatriphenylene derivatives exhibiting thermally activated delayed fluorescence: design and synthesis, photophysical properties and OLED characteristics

    PubMed Central

    Takahashi, Takehiro; Shizu, Katsuyuki; Yasuda, Takuma; Togashi, Kazunori; Adachi, Chihaya

    2014-01-01

    A new series of luminescent 1,4-diazatriphenylene (ATP) derivatives with various peripheral donor units, including phenoxazine, 9,9-dimethylacridane and 3-(diphenylamino)carbazole, is synthesized and characterized as thermally activated delayed fluorescence (TADF) emitters. The influence of the donor substituents on the electronic and photophysical properties of the materials is investigated by theoretical calculations and experimental spectroscopic measurements. These ATP-based molecules with donor–acceptor–donor (D–A–D) structures can reduce the singlet–triplet energy gap (0.04–0.26 eV) upon chemical modification of the ATP core, and thus exhibit obvious TADF characteristics in solution and doped thin films. As a demonstration of the potential of these materials, organic light-emitting diodes containing the D–A–D-structured ATP derivatives as emitters are fabricated and tested. External electroluminescence quantum efficiencies above 12% and 8% for green- and sky-blue-emitting devices, respectively, are achieved. PMID:27877670

  10. Molecular cloning and expression of active Ole e 3, a major allergen from olive-tree pollen and member of a novel family of Ca2+-binding proteins (polcalcins) involved in allergy.

    PubMed

    Ledesma, A; Villalba, M; Batanero, E; Rodríguez, R

    1998-12-01

    A cDNA encoding Ole e 3, a major allergen from olive-tree pollen, has been cloned and sequenced. A strategy based on two-step PCR amplification towards the 5' end and 3' end, with an internal specific primer, has been used. The isolated cDNA contains an open reading frame coding for a polypeptide of 84 amino acids, which is in agreement with the composition and molecular mass of the natural allergen, exhibiting two 12-residue segments homologous to Ca2+-binding sites of EF-hand type. The cDNA was inserted into the pET-11b expression vector and over-expressed in Escherichia coli. The purified recombinant protein shows identical secondary structure to that of the natural allergen and is able to bind both IgE from sera of patients allergic to olive pollen and polyclonal antibodies raised against olive-pollen Ole e 3. The capacity of binding Ca2+ has been demonstrated for both natural and recombinant allergens. RNA transcripts of Ole e 3 were only detected in pollen tissue. Northern-blot and Western-blot analyses of poly(A)+ RNA and protein extracts, respectively, obtained from a variety of olive-tree-related and nonrelated mature pollens demonstrated the presence of Ole e 3 homologous proteins. This indicates a sequence conservation and widespread distribution for this family of Ca2+-binding proteins that can be responsible for allergenic cross-reactivity. We suggest the tentative generic name of polcalcins for the members of this family of Ca2+-binding proteins from pollen.

  11. Matrix viscoplasticity and its shielding by active mechanics in microtissue models: experiments and mathematical modeling

    NASA Astrophysics Data System (ADS)

    Liu, Alan S.; Wang, Hailong; Copeland, Craig R.; Chen, Christopher S.; Shenoy, Vivek B.; Reich, Daniel H.

    2016-09-01

    The biomechanical behavior of tissues under mechanical stimulation is critically important to physiological function. We report a combined experimental and modeling study of bioengineered 3D smooth muscle microtissues that reveals a previously unappreciated interaction between active cell mechanics and the viscoplastic properties of the extracellular matrix. The microtissues’ response to stretch/unstretch actuations, as probed by microcantilever force sensors, was dominated by cellular actomyosin dynamics. However, cell lysis revealed a viscoplastic response of the underlying model collagen/fibrin matrix. A model coupling Hill-type actomyosin dynamics with a plastic perfectly viscoplastic description of the matrix quantitatively accounts for the microtissue dynamics, including notably the cells’ shielding of the matrix plasticity. Stretch measurements of single cells confirmed the active cell dynamics, and were well described by a single-cell version of our model. These results reveal the need for new focus on matrix plasticity and its interactions with active cell mechanics in describing tissue dynamics.

  12. Matrix viscoplasticity and its shielding by active mechanics in microtissue models: experiments and mathematical modeling

    PubMed Central

    Liu, Alan S.; Wang, Hailong; Copeland, Craig R.; Chen, Christopher S.; Shenoy, Vivek B.; Reich, Daniel H.

    2016-01-01

    The biomechanical behavior of tissues under mechanical stimulation is critically important to physiological function. We report a combined experimental and modeling study of bioengineered 3D smooth muscle microtissues that reveals a previously unappreciated interaction between active cell mechanics and the viscoplastic properties of the extracellular matrix. The microtissues’ response to stretch/unstretch actuations, as probed by microcantilever force sensors, was dominated by cellular actomyosin dynamics. However, cell lysis revealed a viscoplastic response of the underlying model collagen/fibrin matrix. A model coupling Hill-type actomyosin dynamics with a plastic perfectly viscoplastic description of the matrix quantitatively accounts for the microtissue dynamics, including notably the cells’ shielding of the matrix plasticity. Stretch measurements of single cells confirmed the active cell dynamics, and were well described by a single-cell version of our model. These results reveal the need for new focus on matrix plasticity and its interactions with active cell mechanics in describing tissue dynamics. PMID:27671239

  13. Follow-up: Prospective compound design using the 'SAR Matrix' method and matrix-derived conditional probabilities of activity.

    PubMed

    Gupta-Ostermann, Disha; Hirose, Yoichiro; Odagami, Takenao; Kouji, Hiroyuki; Bajorath, Jürgen

    2015-01-01

    In a previous Method Article, we have presented the 'Structure-Activity Relationship (SAR) Matrix' (SARM) approach. The SARM methodology is designed to systematically extract structurally related compound series from screening or chemical optimization data and organize these series and associated SAR information in matrices reminiscent of R-group tables. SARM calculations also yield many virtual candidate compounds that form a "chemical space envelope" around related series. To further extend the SARM approach, different methods are developed to predict the activity of virtual compounds. In this follow-up contribution, we describe an activity prediction method that derives conditional probabilities of activity from SARMs and report representative results of first prospective applications of this approach.

  14. OLED lightings with optical feedback for luminance difference compensation

    NASA Astrophysics Data System (ADS)

    Shin, D. K.; Park, J. W.

    2013-12-01

    We have employed an optical feedback circuit in an organic light-emitting diode (OLED) lighting system to ensure uniform light output across large-area OLED lighting tiles. In a lighting system with several large-area OLED lighting tiles involved, the panel aging (luminance decrease) may appear differently in each, resulting in a falling-off in lighting quality. To tackle this, light output from each OLED tile is monitored by the optical feedback circuit that consists of a photodetector, I-V converter, 10-bit analogue-digital converter (ADC), and comparator. A photodetector mounted on a glass side generates a feedback signal (current) by detecting side-emitting OLED light. To monitor bottom-emitting output light by detecting side-emitting OLED light, a mapping table between the ADC value and the luminance of bottom emission has been established. If the ADC value is lower or higher than the reference one corresponding to the target luminance of OLED tiles, a micro controller unit adjusts the pulse width modulation used for the control of the power supplied to OLED tiles in such a way that the ADC value obtained from optical feedback is the same as the reference one. As a result, the target luminance of each individual OLED tile is kept unchanged. With the optical feedback circuit included in the lighting system, we have observed less than 2% difference in relative intensity of neighboring OLED tiles.

  15. Protease induced plasticity: matrix metalloproteinase-1 promotes neurostructural changes through activation of protease activated receptor 1

    PubMed Central

    Allen, Megan; Ghosh, Suhasini; Ahern, Gerard P.; Villapol, Sonia; Maguire-Zeiss, Kathleen A.; Conant, Katherine

    2016-01-01

    Matrix metalloproteinases (MMPs) are a family of secreted endopeptidases expressed by neurons and glia. Regulated MMP activity contributes to physiological synaptic plasticity, while dysregulated activity can stimulate injury. Disentangling the role individual MMPs play in synaptic plasticity is difficult due to overlapping structure and function as well as cell-type specific expression. Here, we develop a novel system to investigate the selective overexpression of a single MMP driven by GFAP expressing cells in vivo. We show that MMP-1 induces cellular and behavioral phenotypes consistent with enhanced signaling through the G-protein coupled protease activated receptor 1 (PAR1). Application of exogenous MMP-1, in vitro, stimulates PAR1 dependent increases in intracellular Ca2+ concentration and dendritic arborization. Overexpression of MMP-1, in vivo, increases dendritic complexity and induces biochemical and behavioral endpoints consistent with increased GPCR signaling. These data are exciting because we demonstrate that an astrocyte-derived protease can influence neuronal plasticity through an extracellular matrix independent mechanism. PMID:27762280

  16. Status and potential for phosphorescent OLED technology

    NASA Astrophysics Data System (ADS)

    Hack, M.; Weaver, M. S.; Adamovich, V.; Kwong, R. C.; Lu, M. H.; Brown, J. J.

    2005-07-01

    As organic light emitting device (OLED) technology is building up momentum in the commercial marketplace, phosphorescent OLEDs (PHOLEDsTM) are proving themselves to be an ideal display medium for a wide range of product applications: from small mobile displays to large area TVs. As part of this work we continue to advance PHOLED technology by new materials design and device architectures. For example a green PHOLED with 4.3 V, 70 cd/A, 50 lm/W and > 10,000 hours lifetime at 1,000 cd/m2 is reported. PHOLEDs enable very low power consumption displays with low display operating temperatures, and can be deposited by a range of different deposition techniques. Along with state-of-the-art device performance we report results on the ruggedness of PHOLED materials in high volume manufacturing environments.

  17. OLES : Online Laboratory for Environmental Sciences

    NASA Astrophysics Data System (ADS)

    Anquetin, Sandrine; Beaufil, Xavier; Chaffard, Véronique; Juen, Patrick

    2015-04-01

    One of the major scientific challenges in the 21st century is to improve our understanding on the evolution of the water cycle associated with the climate variability. Main issues concern the prediction of i) the water resource and the access to drinkable water and ii) the extreme events, both droughts and floods. Observation strategies covering a wide range of space and time scales must therefore be set up, while continuing advanced research on the involved mechanisms and developing integrated modeling approaches. Within this general context, the present work relies on three natural observatories, located in West Africa, Worldwide Glaciers, and in Mediterranean region, managed at LTHE (Laboratoire d'étude des Transferts en Hydrologie et Environnement; Grenoble, France) and gathered at OSUG (Observatoire des Sciences de l'Univers; Grenoble, France). Their scientific objectives aim at improving the understanding of the water cycle functioning, providing water and mass balances for multi-scale basin sizes, and evaluating the hydrological impacts of the evolving climate. Water cycle variables (precipitation; soil moisture; snow cover; discharge; air and river temperatures; suspended material; etc …) are observed and recorded in 3 different databases built under specific technical constraints linked to the respective partnerships of the natural observatories. Each of the observatories has its own database, and modeling tools were developed separately leading to important efforts often duplicated. Therefore, there was a need to build an integrated cyber-infrastructure to provide access to data, and to shared tools and models that enable the understanding of the water cycle. This is the project called OLES, for Online Laboratory for Environmental Sciences. Focused on the understanding of the water cycle under contrasted climates, OLES facilitates the work of the scientific community and then, help interactions between the research community and water agencies or

  18. Analytical Model of Water Flow in Coal with Active Matrix

    NASA Astrophysics Data System (ADS)

    Siemek, Jakub; Stopa, Jerzy

    2014-12-01

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

  19. Matrix formulation of the surface-enhanced Raman optical activity theory

    NASA Astrophysics Data System (ADS)

    Bouř, Petr

    2007-04-01

    The surface-enhanced Raman optical activity theory [J. Chem. Phys.125, 124704 (2006)] is formulated in a matrix form, which makes the formalism simpler and allows to extend it for more complicated colloid and molecular systems.

  20. "Click" synthesis of small molecule probes for activity-based fingerprinting of matrix metalloproteases.

    PubMed

    Wang, Jun; Uttamchandani, Mahesh; Li, Junqi; Hu, Mingyu; Yao, Shao Q

    2006-09-28

    By using "Click Chemistry", we achieved the facile synthesis of various affinity-based hydroxamate probes that enable generation of activity-based fingerprints of a variety of metalloproteases, including matrix metalloproteases (MMPs), in proteomics experiments.

  1. Multifunction Habitat Workstation/OLED Development

    NASA Technical Reports Server (NTRS)

    Schumacher, Shawn; Salazar, George; Schmidt, Oron

    2013-01-01

    This paper gives a general outline of both a multifunction habitat workstation and the research put into an Organic Light Emitting Diode (OLED) device. It first covers the tests that the OLED device will go through to become flight ready along with reasoning. Guidelines for building an apparatus to house the display and its components are given next, with the build of such following. The three tests the OLED goes through are presented (EMI, Thermal/Vac, Radiation) along with the data recovered. The second project of a multifunction workstation is then discussed in the same pattern. Reasoning for building such a workstation with telepresence in mind is offered. Build guidelines are presented first, with the build timeline following. Building the workstation will then be shown in great detail along with accompanying photos. Once the workstation has been discussed, the versatility of its functions are given. The paper concludes with future views and concepts that can added when the time or technology presents itself.

  2. Update of status of OLED technology

    NASA Astrophysics Data System (ADS)

    Saini, Gurdial S.

    1999-08-01

    Flat-panel displays are basically of two types: light valve (needs an external source of light) and emissive type (generates light at the display surface). The light emitting diode (LED) display is of the emissive type. The inorganic LED displays have been in use for more than 25 years in one form or the other. Because of certain limitations of inorganic materials (such as luminous efficiency and color), LED applications have been limited. The recent discovery (over the past 15 years) of polymer and organic materials has changed LED prospects. It now may become possible to make LED displays that are inexpensive, bright, low-power, large size, and at the same time provide full color. If present research objectives are met, LEDs, especially organic LEDs (OLEDs), may have the potential to revolutionize a certain segment of flat- panel display market. This paper discusses various types of OLED technologies with particular reference to Small Molecule and Conjugated Polymer displays. Some unique versions of these displays such as transparent displays and flexible displays will also be discussed. A part of the discussion will be devoted to various driver circuitry and full color generation schemes. A comprehensive list of various research efforts in OLED technology all over the world will be presented with their differentiating features. The strength of the underlying technology and the challenges facing these types of displays will be discussed.

  3. A Novel Lighting OLED Panel Design.

    PubMed

    Zhang, Enyang; Xia, Weigao; Yan, Xiaojian

    2016-11-25

    A novel OLED (organic light emitting diode) lighting panel, which uses a special layout design, can reduce the photolithography cycles and process costs and is more reliable. It only needs two steps of photolithography cycles, which include an ITO (InSnO compound transparent oxide) pattern and insulator pattern. There is no need for the metal bus pattern of the ordinary design. The OLED device structure is a type of red-green-blue (RGB)-stacked emitting layer that has a good color index and greater adjustability, which improves the performance of the device. This novel design has the same equipment and material requirement compared to the ordinary design, and it is very beneficial in terms of high volume and low-cost production. It uses a hyper driving method because the entire OLED lighting panel is divided into many sub-emitting units; if one of the sub-emitting units is burned out, it has no effect on the adjacent sub-emitting unit, so the reliability is markedly better than the ordinary design.

  4. Mutagenesis and redox partners analysis of the P450 fatty acid decarboxylase OleTJE

    PubMed Central

    Fang, Bo; Xu, Huifang; Liu, Yi; Qi, Fengxia; Zhang, Wei; Chen, Hui; Wang, Cong; Wang, Yilin; Yang, Wenxia; Li, Shengying

    2017-01-01

    The cytochrome P450 enzyme OleTJE from Jeotgalicoccus sp. ATCC 8456 is capable of converting free long-chain fatty acids into α-alkenes via one-step oxidative decarboxylation in presence of H2O2 as cofactor or using redox partner systems. This enzyme has attracted much attention due to its intriguing but unclear catalytic mechanism and potential application in biofuel production. Here, we investigated the functionality of a select group of residues (Arg245, Cys365, His85, and Ile170) in the active site of OleTJE through extensive mutagenesis analysis. The key roles of these residues for catalytic activity and reaction type selectivity were identified. In addition, a range of heterologous redox partners were found to be able to efficiently support the decarboxylation activity of OleTJE. The best combination turned out to be SeFdx-6 (ferredoxin) from Synechococcus elongatus PCC 7942 and CgFdR-2 (ferredoxin reductase) from Corynebacterium glutamicum ATCC 13032, which gave the highest myristic acid conversion rate of 94.4%. Moreover, Michaelis-Menton kinetic parameters of OleTJE towards myristic acid were determined. PMID:28276499

  5. Mutagenesis and redox partners analysis of the P450 fatty acid decarboxylase OleTJE.

    PubMed

    Fang, Bo; Xu, Huifang; Liu, Yi; Qi, Fengxia; Zhang, Wei; Chen, Hui; Wang, Cong; Wang, Yilin; Yang, Wenxia; Li, Shengying

    2017-03-09

    The cytochrome P450 enzyme OleTJE from Jeotgalicoccus sp. ATCC 8456 is capable of converting free long-chain fatty acids into α-alkenes via one-step oxidative decarboxylation in presence of H2O2 as cofactor or using redox partner systems. This enzyme has attracted much attention due to its intriguing but unclear catalytic mechanism and potential application in biofuel production. Here, we investigated the functionality of a select group of residues (Arg245, Cys365, His85, and Ile170) in the active site of OleTJE through extensive mutagenesis analysis. The key roles of these residues for catalytic activity and reaction type selectivity were identified. In addition, a range of heterologous redox partners were found to be able to efficiently support the decarboxylation activity of OleTJE. The best combination turned out to be SeFdx-6 (ferredoxin) from Synechococcus elongatus PCC 7942 and CgFdR-2 (ferredoxin reductase) from Corynebacterium glutamicum ATCC 13032, which gave the highest myristic acid conversion rate of 94.4%. Moreover, Michaelis-Menton kinetic parameters of OleTJE towards myristic acid were determined.

  6. Biotransformation and adsorption of pharmaceutical and personal care products by activated sludge after correcting matrix effects.

    PubMed

    Deng, Yu; Li, Bing; Yu, Ke; Zhang, Tong

    2016-02-15

    This study reported significant suppressive matrix effects in analyses of six pharmaceutical and personal care products (PPCPs) in activated sludge, sterilized activated sludge and untreated sewage by ultra-performance liquid chromatography-tandem mass spectrometry. Quantitative matrix evaluation on selected PPCPs supplemented the limited quantification data of matrix effects on mass spectrometric determination of PPCPs in complex environment samples. The observed matrix effects were chemical-specific and matrix-dependent, with the most pronounced average effect (-55%) was found on sulfadiazine in sterilized activated sludge. After correcting the matrix effects by post-spiking known amount of PPCPs, the removal mechanisms and biotransformation kinetics of selected PPCPs in activated sludge system were revealed by batch experiment. Experimental data elucidated that the removal of target PPCPs in the activated sludge process was mainly by biotransformation while contributions of adsorption, hydrolysis and volatilization could be neglected. High biotransformation efficiency (52%) was observed on diclofenac while other three compounds (sulfadiazine, sulfamethoxazole and roxithromycin) were partially biotransformed by ~40%. The other two compounds, trimethoprim and carbamazepine, showed recalcitrant to biotransformation of the activated sludge.

  7. Physical process in OLED architectures with transparent carbon nanotube sheets as electrodes

    NASA Astrophysics Data System (ADS)

    Ovalle Robles, Raquel

    There has been a great deal of activity in the development of organic light emitting diodes (OLED's) and polymeric light emitting diodes (PLED's). Research in OLEDs and PLEDs have been having a significant development over the last few years towards commercialization, extended life time, stability, efficiency and new fabrication processes suitable for mass production are some of the topics. The potential for commercialization is high due to their low operating voltage (typically between 2.5 to 5 volts), their high brightness and their ease to process. They are light weight and can be flexible. Furthermore, these devices can be easily color tune to produce red, green and blue colors. Research in this type of electroluminescence devices has advanced rapidly and device prototypes now meet realistic specifications for applications. By proper device engineering these devices can achieve high electroluminescence efficiencies and lifetimes. In this research project we present several methods and procedures that we developed and use to produce OLEDs and PLEDs. We have incorporated quantum dots into OLEDs as emissive dopants that contribute to the control of the spectral distribution of emitted light allowing the production of white OLEDs using both a multilayer structure with emission from multiple layers and a bilayer structure with emission from only the quantum dots. We have also produced PLED devices with a new family of novel PPV polymers achieving high bright efficient devices. OLED structures with transparent carbon nanotube sheets, obtained by dry drawing from a CVD-grown forest have been produced. The devices shown to be very bright and the MCNT sheets are efficient hole-injecting anodes for OLEDs Also, for flexible display applications, there is a need for high strength, flexible materials which can be deposited as transparent films and can act as hole injectors for organic films. By using a hybrid ITO/MWCNT anode onto flexible substrates an enhancement of the

  8. Steerable patterned OLED backlight for autostereoscopic display application

    NASA Astrophysics Data System (ADS)

    Vogel, Uwe; Fehse, Karsten; Wartenberg, Philipp; Knobbe, Jens; Scholles, Michael; Richter, Bernd; Hild, Olaf

    2015-09-01

    OLED can be applied as highly efficient and high-resolution patternable illumination source for controllable and steerable backlights, e.g., for use in autostereoscopic displays. To evaluate technology and approach a 3.5" 3D QVGA display prototype has been developed and combines several achievements: large-area OLED backlight, highly-efficient and fast-response OLED top-emitter, striped patterned backlight, individual electronic driving for adaptive backlight control and 3D mobile display application.

  9. Efficient, deep-blue TADF-emitters for OLED display applications (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Volz, Daniel; Baumann, Thomas

    2016-09-01

    Currently, the mobile display market is strongly shifting towards AMOLED technology, in order to enable curved and flexible displays. This leads to a growing demand for highly efficient OLED emitters to reduce the power consumption and increase display resolution at the same time. While highly efficient green and red OLEDs already found their place in commercial OLED-displays, the lack of efficient blue emitters is still an issue. Consequently, the active area for blue is considerably larger than for green and red pixels, to make up for the lower efficiency. We intend to close this efficiency-gap with novel emitters based on thermally activated delayed fluorescence (TADF) technology. Compared to state-of-the-art fluorescent dopants, the efficiency of TADF-emitters is up to four times higher. At the same time, it is possible to design them in a way to maintain deep blue emission, i.e. CIE y < 0.2. These aspects are relevant to produce efficient high resolution AMOLED displays. Apart from these direct customer benefits, our TADF technology does not contain any rare elements, which allows for the fabrication of sustainable OLED technology. In this work, we highlight one of our recently developed blue TADF materials. Basic material properties as well as first device results are discussed. In a bottom-emitting device, a CIEx/CIEy coordinate of (0.16/0.17) was achieved with efficiency values close to 20% EQE.

  10. Active matrix organic light-emitting diode (AMOLED) performance and life test results

    NASA Astrophysics Data System (ADS)

    Fellowes, David A.; Wood, Michael V.; Hastings, Arthur R., Jr.; Draper, Russell S.; Ghosh, Amalkumar; Prache, Olivier; Wacyk, Ihor; Ali, Tariq; Khayrullin, Ilyas

    2011-06-01

    The US Army and eMagin Corporation established a Cooperative Research and Development Agreement (CRADA) to characterize the ongoing improvements in the lifetime of OLED displays. This CRADA also called for the evaluation of OLED performance as the need arises, especially when new products are developed or when a previously untested parameter needs to be understood. In 2006, eMagin Corporation developed long-life OLED-XL devices for use in their AMOLED microdisplays for head-worn applications. Through research and development programs from 2007 to 2010 with the US Government, eMagin made additional improvements in OLED life and developed the first SXGA (1280 X 1024 triad pixels) OLED microdisplay. US Army RDECOM CERDEC NVESD conducted life and performance tests on these displays, publishing results at the 2007, 2008, 2009, and 2010 SPIE Defense and Security Symposia1,2,3,4. Life and performance tests have continued through 2010, and this data will be presented along with a recap of previous data. This should result in a better understanding of the applicability of AMOLEDs in military and commercial head mounted systems: where good fits are made, and where further development might be desirable.

  11. Active matrix organic light emitting diode (AMOLED) performance and life test results

    NASA Astrophysics Data System (ADS)

    Fellowes, David A.; Botkin, Michael E.; Draper, Russell S.; Coletta, Jason

    2013-05-01

    The U.S. Army and eMagin Corporation established a Cooperative Research and Development Agreement (CRADA) to characterize the ongoing improvements in the lifetime of OLED displays. This CRADA also called for the evaluation of OLED performance as the need arises, especially when new products are developed or when a previously untested parameter needs to be understood. In 2006, eMagin Corporation developed long-life OLED-XL devices for use in their AMOLED microdisplays for head-worn applications. Through Research and Development programs from 2007 to 2012 with the U.S. Government, eMagin made additional improvements in OLED life and developed the first SXGA (1280 X 1024 with triad pixels) and WUXGA (1920 X 1200 with triad pixels) OLED microdisplays. US Army RDECOM CERDEC NVESD conducted life and performance tests on these displays, publishing results at the 2012, 2011, 2010, 2009, 2008, and 2007 SPIE Defense, Security and Sensing Symposia. Life and performance tests have continued through 2013, and this data will be presented along with a comparison to previous data. This should result in a better understanding of the applicability of AMOLEDs in military and commercial head mounted systems, where good fits are made, and where further development might be desirable.

  12. pH-Sensitive Microparticles with Matrix-Dispersed Active Agent

    NASA Technical Reports Server (NTRS)

    Li, Wenyan (Inventor); Buhrow, Jerry W. (Inventor); Jolley, Scott T. (Inventor); Calle, Luz M. (Inventor)

    2014-01-01

    Methods to produce pH-sensitive microparticles that have an active agent dispersed in a polymer matrix have certain advantages over microcapsules with an active agent encapsulated in an interior compartment/core inside of a polymer wall. The current invention relates to pH-sensitive microparticles that have a corrosion-detecting or corrosion-inhibiting active agent or active agents dispersed within a polymer matrix of the microparticles. The pH-sensitive microparticles can be used in various coating compositions on metal objects for corrosion detecting and/or inhibiting.

  13. Mechanophore activation in a crosslinked polymer matrix via instrumented indentation

    NASA Astrophysics Data System (ADS)

    Davis, Chelsea; Forster, Aaron; Woodcock, Jeremiah; Wang, Muzhou; Gilman, Jeffrey; Material Measurement Laboratory Team

    Recent advances in mechanically-activated fluorophores will enable a host of unique scientific challenges and opportunities to be addressed. Several mechanophores (MPs) in polymers have been reported, yet the specific deformation required to activate these molecules in a bulk polymer network has not been sufficiently specified. In an effort to develop the mechano-activation/deformation relationship of a spirolactam-based MP, scratches were applied to a MP-functionalized glassy crosslinked material at varying normal loads and lateral displacement rates. This experimental design allowed strain and strain rate effects to be decoupled. The fluorescence activation was then observed with a laser scanning confocal microscope. Areas of elastic and plastic deformation as well as brittle fracture were observed within each scratch as the normal loading of the indenter increased. The fluorescence intensity increased with increasing strain. Contact mechanics models are employed to demonstrate that relatively high degrees of strain are required to initiate the ring-opening activation transition within the spirolactam-based MP. These self-reporting damage sensors can be incorporated within polymeric coatings to allow real time structural health monitoring for a myriad of applications.

  14. Plasma matrix metalloproteinase-9 activity in cats with lymphoma.

    PubMed

    Tamamoto, T; Ohno, K; Takahashi, M; Fukushima, K; Kanemoto, H; Fujino, Y; Tsujimoto, H

    2017-03-01

    In this study, plasma MMP-9 activity was evaluated in cats with lymphoma. Plasma samples were obtained from 26 cats with lymphoma before treatment. From 13 of the included 26 cats, plasma samples were obtained 4 weeks after the initiation of treatment. Plasma samples were also obtained from 10 healthy cats as a control. Plasma MMP-9 activity was examined by gelatin zymography and semi-quantitative value (arbitrary unit; a.u.) for each sample was calculated. Relatively high levels of MMP-9 were observed in cats with lymphoma compared with those in healthy control cats. MMP-9 quantification through zymography showed significantly higher activity in cats with lymphoma (median, 0.63 a.u.; range, 0.23-3.24 a.u.) than in healthy controls (0.22 a.u.; 0.12-0.46 a.u.; P < 0.01). MMP-9 activities were significantly different before (0.73 a.u.; 0.30-3.24 a.u.) and after treatment (0.50 a.u.; 0.14-1.32 a.u.; P = 0.017). Measuring plasma MMP-9 activity in cats with lymphoma may become an appropriate monitoring tool for feline lymphoma.

  15. Bovine dentine organic matrix down-regulates osteoclast activity.

    PubMed

    Sriarj, Wantida; Aoki, Kazuhiro; Ohya, Keiichi; Takagi, Yuzo; Shimokawa, Hitoyata

    2009-01-01

    Physiological root resorption is a phenomenon that normally takes place in deciduous teeth; root resorption of permanent teeth occurs only under pathological conditions. The molecular mechanisms underlying these processes are still unclear. Our previous study showed that osteoclasts cultured on deciduous dentine exhibited a higher degree of resorption and higher levels of cathepsin K and MMP-9 mRNA than osteoclasts cultured on permanent dentine. These results could be because of different susceptibilities to acid and the different organic matrices between deciduous and permanent dentine. Thus, the purpose of this study was to investigate the effect of dentine extracts from bovine deciduous and permanent dentine on osteoclast activity. Osteoclasts, obtained from mouse bone marrow cells co-cultured with an osteoblast-rich fraction in the presence of 1,25-(OH)(2)-vitamin D3 and PGE2, were incubated with or without 0.6 M HCl extracts from bovine deciduous or permanent dentine for 48 h. TRAP positive cell number, TRAP activity, the areas of resorption pits, and mRNA levels of TRAP, v-ATPase, calcitonin receptor, cathepsin K, and MMP-9 were examined. The results illustrated that TRAP activity, the resorbed area, and the mRNA levels of osteoclast marker genes seemed to be suppressed by both deciduous and permanent dentine extracts. These findings indicate that some factors that suppress osteoclast activity are contained in both deciduous and permanent dentine extracts. Although there was no significant difference in osteoclast activity between deciduous and permanent dentine extracts, osteoclasts incubated with permanent dentine extracts tend to exhibit less resorption activity than those incubated with deciduous dentine extracts. However, we could not clearly explain the causes of this.

  16. Immobilization of cesium in alkaline activated fly ash matrix

    NASA Astrophysics Data System (ADS)

    Fernandez-Jimenez, A.; Macphee, D. E.; Lachowski, E. E.; Palomo, A.

    2005-11-01

    The immobilization potential of alkaline activated fly ash (AAFA) matrices for cesium has been investigated. The presence of Cs in the AAFA pastes, prepared using 8M NaOH solution as activator, showed no significant adverse effects on mechanical strength or microstructure, nor were significant quantities of Cs leached following application of the Toxic Characteristic Leaching Procedure (TCLP) and American Nuclear Society (ANS) 16.1 leaching protocols. Microstructural analysis shows Cs associated with the main reaction product in the AAFA suggesting that cesium is chemically bound rather than physically encapsulated. It is proposed that cesium is incorporated into the alkaline aluminosilicate gel, a precursor for zeolite formation.

  17. Active layer solution-processed NIR-OLEDs based on ternary erbium(III) complexes with 1,1,1-trifluoro-2,4-pentanedione and different N,N-donors.

    PubMed

    Martín-Ramos, P; Coya, C; Lavín, V; Martín, I R; Silva, M Ramos; Silva, P S Pereira; García-Vélez, M; Alvarez, A L; Martín-Gil, J

    2014-12-28

    Using a fluorinated 1,1,1-trifluoro-2,4-pentanedione (Htfac) ligand and either 2,2'-bipyridine (bipy), bathophenanthroline (bath) or 5-nitro-1,10-phenanthroline (5NO2phen) as an ancillary ligand, three new ternary erbium(iii) octacoordinated complexes have been synthesized. The single crystal structures of the new complexes (namely [Er(tfac)3(bipy)], [Er(tfac)3(bath)] and [Er(tfac)3(5NO2phen)]) have been determined and their properties have been investigated by Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy and thermodynamic analysis. After ligand-mediated excitation of these complexes in the UV, they all show the characteristic near-infrared (NIR) luminescence of the corresponding Er(3+) ion at 1532 nm. The same emission in the C-band transmission window can also be obtained from the solution-processed organic light-emitting diodes (OLEDs) with structure: glass/ITO/PEDOT:PSS/[Er(tfac)3(N,N-donor)]/Ca/Al. In spite of the fact that the photoluminescence intensity of [Er(tfac)3(5NO2phen)] is stronger than those of [Er(tfac)3(bipy)] and [Er(tfac)3(bath)], the best electroluminescence results correspond to the OLED based on the [Er(tfac)3(bath)] complex, as a consequence of the superior electron transport capabilities of bathophenanthroline.

  18. Hydrogen peroxide-independent production of α-alkenes by OleTJE P450 fatty acid decarboxylase

    PubMed Central

    2014-01-01

    Background Cytochrome P450 OleTJE from Jeotgalicoccus sp. ATCC 8456, a new member of the CYP152 peroxygenase family, was recently found to catalyze the unusual decarboxylation of long-chain fatty acids to form α-alkenes using H2O2 as the sole electron and oxygen donor. Because aliphatic α-alkenes are important chemicals that can be used as biofuels to replace fossil fuels, or for making lubricants, polymers and detergents, studies on OleTJE fatty acid decarboxylase are significant and may lead to commercial production of biogenic α-alkenes in the future, which are renewable and more environmentally friendly than petroleum-derived equivalents. Results We report the H2O2-independent activity of OleTJE for the first time. In the presence of NADPH and O2, this P450 enzyme efficiently decarboxylates long-chain fatty acids (C12 to C20) in vitro when partnering with either the fused P450 reductase domain RhFRED from Rhodococcus sp. or the separate flavodoxin/flavodoxin reductase from Escherichia coli. In vivo, expression of OleTJE or OleTJE-RhFRED in different E. coli strains overproducing free fatty acids resulted in production of variant levels of multiple α-alkenes, with a highest total hydrocarbon titer of 97.6 mg·l-1. Conclusions The discovery of the H2O2-independent activity of OleTJE not only raises a number of fundamental questions on the monooxygenase-like mechanism of this peroxygenase, but also will direct the future metabolic engineering work toward improvement of O2/redox partner(s)/NADPH for overproduction of α-alkenes by OleTJE. PMID:24565055

  19. Differential metabolic activity in the striosome and matrix compartments of the rat striatum during natural behaviors.

    PubMed

    Brown, Lucy L; Feldman, Samuel M; Smith, Diane M; Cavanaugh, James R; Ackermann, Robert F; Graybiel, Ann M

    2002-01-01

    The striosome and matrix compartments of the striatum are clearly identified by their neurochemical expression patterns and anatomical connections. To determine whether these compartments are distinguishable functionally, we used [14C]deoxyglucose metabolic mapping in the rat and tested whether neutral behavioral states (free movement, gentle restraint, and focal tactile stimulation under gentle restraint) were associated with regions of high metabolic activity in the matrix, in striosomes, or in both. We identified metabolic peaks in the striatum by means of image analysis, striosome-matrix boundaries by [3H]naloxone binding, and primary somatosensory corticostriatal input clusters by injections of anterograde tracer into electrophysiologically identified sites in SI. Peak metabolic activity was primarily confined to the matrix compartment under each behavioral condition. These findings show that during relatively neutral behavioral conditions the balance of activity between the two compartments favors the matrix and suggest that this balance is present in the striatum as part of normal behavior and processing of afferent activity.

  20. Cyclical strain modulates metalloprotease and matrix gene expression in human tenocytes via activation of TGFβ.

    PubMed

    Jones, Eleanor R; Jones, Gavin C; Legerlotz, Kirsten; Riley, Graham P

    2013-12-01

    Tendinopathies are a range of diseases characterised by degeneration and chronic tendon pain and represent a significant cause of morbidity. Relatively little is known about the underlying mechanisms; however onset is often associated with physical activity. A number of molecular changes have been documented in tendinopathy such as a decrease in overall collagen content, increased extracellular matrix turnover and protease activity. Metalloproteinases are involved in the homeostasis of the extracellular matrix and expression is regulated by mechanical strain. The aims of this study were to determine the effects of strain upon matrix turnover by measuring metalloproteinase and matrix gene expression and to elucidate the mechanism of action. Primary Human Achilles tenocytes were seeded in type I rat tail collagen gels in a Flexcell™ tissue train system and subjected to 5% cyclic uniaxial strain at 1Hz for 48h. TGFβ1 and TGFβRI inhibitor were added to selected cultures. RNA was measured using qRT-PCR and TGFβ protein levels were determined using a cell based luciferase assay. We observed that mechanical strain regulated the mRNA levels of multiple protease and matrix genes anabolically, and this regulation mirrored that seen with TGFβ stimulation alone. We have also demonstrated that the inhibition of the TGFβ signalling pathway abrogated the strain induced changes in mRNA and that TGFβ activation, rather than gene expression, was increased with mechanical strain. We concluded that TGFβ activation plays an important role in mechanotransduction. Targeting this pathway may have its place in the treatment of tendinopathy.

  1. Matrix rigidity activates Wnt signaling through down-regulation of Dickkopf-1 protein.

    PubMed

    Barbolina, Maria V; Liu, Yiuying; Gurler, Hilal; Kim, Mijung; Kajdacsy-Balla, Andre A; Rooper, Lisa; Shepard, Jaclyn; Weiss, Michael; Shea, Lonnie D; Penzes, Peter; Ravosa, Matthew J; Stack, M Sharon

    2013-01-04

    Cells respond to changes in the physical properties of the extracellular matrix with altered behavior and gene expression, highlighting the important role of the microenvironment in the regulation of cell function. In the current study, culture of epithelial ovarian cancer cells on three-dimensional collagen I gels led to a dramatic down-regulation of the Wnt signaling inhibitor dickkopf-1 with a concomitant increase in nuclear β-catenin and enhanced β-catenin/Tcf/Lef transcriptional activity. Increased three-dimensional collagen gel invasion was accompanied by transcriptional up-regulation of the membrane-tethered collagenase membrane type 1 matrix metalloproteinase, and an inverse relationship between dickkopf-1 and membrane type 1 matrix metalloproteinase was observed in human epithelial ovarian cancer specimens. Similar results were obtained in other tissue-invasive cells such as vascular endothelial cells, suggesting a novel mechanism for functional coupling of matrix adhesion with Wnt signaling.

  2. Matrix Rigidity Activates Wnt Signaling through Down-regulation of Dickkopf-1 Protein*

    PubMed Central

    Barbolina, Maria V.; Liu, Yiuying; Gurler, Hilal; Kim, Mijung; Kajdacsy-Balla, Andre A.; Rooper, Lisa; Shepard, Jaclyn; Weiss, Michael; Shea, Lonnie D.; Penzes, Peter; Ravosa, Matthew J.; Stack, M. Sharon

    2013-01-01

    Cells respond to changes in the physical properties of the extracellular matrix with altered behavior and gene expression, highlighting the important role of the microenvironment in the regulation of cell function. In the current study, culture of epithelial ovarian cancer cells on three-dimensional collagen I gels led to a dramatic down-regulation of the Wnt signaling inhibitor dickkopf-1 with a concomitant increase in nuclear β-catenin and enhanced β-catenin/Tcf/Lef transcriptional activity. Increased three-dimensional collagen gel invasion was accompanied by transcriptional up-regulation of the membrane-tethered collagenase membrane type 1 matrix metalloproteinase, and an inverse relationship between dickkopf-1 and membrane type 1 matrix metalloproteinase was observed in human epithelial ovarian cancer specimens. Similar results were obtained in other tissue-invasive cells such as vascular endothelial cells, suggesting a novel mechanism for functional coupling of matrix adhesion with Wnt signaling. PMID:23152495

  3. Organic light emitting diodes (OLEDS) and OLED-based structurally integrated optical sensors

    SciTech Connect

    Cai, Yuankun

    2010-01-01

    General introduction to OLED basics and OLED-based structurally integrated sensors was provided in chapter 1 and chapter 2. As discussed in chapter 3, OLEDs were developed or improved using novel engineering methods for better charge injection (increased by over 1 order of magnitude) and efficiency. As the excitation sources, these OLEDs have preferred characteristics for sensor applications, including narrowed emission, emission at desired wavelength, and enhanced output for reduced EL background, higher absorption and improved device lifetime. In addition to OLEDs with desired performance, sensor integration requires oxidase immobilization with the sensor film for O2-based biological and chemical sensing. Nanoparticles such as ZnO have large surface area and high isoelectric point (~9.5), which favors enzyme immobilization via physical adsorption as well as Coulombic bonding. In chapter 4, it was demonstrated that ZnO could be used for this purpose, although future work is needed to further bond the ZnO to the sensor film. In chapter 5, single unit sensor was extended to multianalyte parallel sensing based on an OLED platform, which is compact and integrated with silicon photodiodes and electronics. Lactate and glucose were simultaneously monitored with a low limit of detection 0.02 mM, fast response time (~1 minute) and dynamic range from 0-8.6 ppm of dissolved oxygen. As discovered in previous work, the dynamic range covers 0-100% gas phase O2 or 0-40 ppm dissolved oxygen at room temperature. PL decay curve, which is used to extract the decay time, is usually not a simple exponential at high O2 concentration, which indicates that O2 is not equally accessible for different luminescent sites. This creates a challenge for data analysis, which however was successfully processed by stretched exponential as shown in chapter 6. This also provides an insight about the distribution of O2:dye collisional quenching

  4. The decellularized porcine heart valve matrix in tissue engineering: platelet adhesion and activation.

    PubMed

    Kasimir, Marie-Theres; Weigel, Guenter; Sharma, Jyotindra; Rieder, Erwin; Seebacher, Gernot; Wolner, Ernst; Simon, Paul

    2005-09-01

    An approach in tissue engineering of heart valves is the use of decellularized xenogeneic matrices to avoid immune response after implantation. The decellularization process must preserve the structural components of the extracellular matrix to provide a biomechanically stable scaffold. However, it is known that in vascular lesions platelet adhesion to extracellular matrix components occurs and platelet activation is induced. In the present study we examined the effects of a decellularized porcine heart valve matrix on thrombocyte activation and the influence of re-endothelialisation in vitro. Porcine pulmonary conduits were decellularized using Triton X-100, Na-deoxycholate and Igepal CA-630 followed by a ribonuclease digestion. Cryostat sections of decellularized heart valves with and without seeding with human umbilical vein endothelial cells (HUVEC) were incubated with platelet rich plasma. Samples were either stained with fluorescent antibodies for CD41 and PAC-I (recognizing the activated fibrinogen receptor) or fixed with glutaraldehyde. Thereafter, the samples were processed for laser scanning microscopy (LSM) or scanning electron microscopy (SEM). Examination by LSM showed numerous platelets with co-localized staining for CD41 and PAC-1 on the nonseeded decellularized heart valve matrix whereas after seeding with endothelial cells no platelet activation was detected. SEM revealed platelet adhesion and aggregate formation only on the surface of the non-seeded or partially denuded matrix specimens. We show in this study that the decellularized porcine matrix acts as a platelet-activating surface. Seeding with endothelial cells effectively abolishes the platelet adhesion and activation and therefore is necessary to eliminate thrombogenicity in tissue engineered heart valves.

  5. Responsibility modulates pain-matrix activation elicited by the expressions of others in pain.

    PubMed

    Cui, Fang; Abdelgabar, Abdel-Rahman; Keysers, Christian; Gazzola, Valeria

    2015-07-01

    Here we examine whether brain responses to dynamic facial expressions of pain are influenced by our responsibility for the observed pain. Participants played a flanker task with a confederate. Whenever either erred, the confederate was seen to receive a noxious shock. Using functional magnetic resonance imaging, we found that regions of the functionally localized pain-matrix of the participants (the anterior insula in particular) were activated most strongly when seeing the confederate receive a noxious shock when only the participant had erred (and hence had full responsibility). When both or only the confederate had erred (i.e. participant's shared or no responsibility), significantly weaker vicarious pain-matrix activations were measured.

  6. Polymer OLED White Light Development Program

    SciTech Connect

    Homer Antoniadis; Vi-En Choong; Stelios Choulis; Brian Cumpston; Rahul Gupta; Mathew Mathai; Michael Moyer; Franky So

    2005-12-19

    OSRAM Opto Semiconductors (OSRAM) successfully completed development, fabrication and characterization of the large area, polymer based white light OLED prototype at their OLED Research and Development (R&D) facility in San Jose, CA. The program, funded by the Department of Energy (DOE), consisted of three key objectives: (1) Develop new polymer materials and device architectures--in order to improve the performance of organic light emitters. (2) Develop processing techniques--in order to demonstrate and enable the manufacturing of large area, white light and color tunable, solid state light sources. (3) Develop new electronics and driving schemes for organic light sources, including color-tunable light sources. The key performance goals are listed. A world record efficiency of 25 lm/W was established for the solution processed white organic device from the significant improvements made during the project. However, the challenges to transfer this technology from an R&D level to a large tile format such as, the robustness of the device and the coating uniformity of large area panels, remain. In this regard, the purity and the blend nature of the materials are two factors that need to be addressed in future work. During the first year, OSRAM's Materials and Device group (M&D) worked closely with the major polymer material suppliers to develop the polymer emissive technology. M&D was successful in demonstrating a 7-8 lm/W white light source which was based on fluorescent materials. However, it became apparent that the major gains in efficiency could only be made if phosphorescent materials were utilized. Thus, in order to improve the performance of the resulting devices, the focus of the project shifted towards development of solution-processable phosphorescent light emitting diodes (PHOLEDs) and device architectures. The result is a higher efficiency than the outlined project milestone.

  7. Integration of OLE into the TACL control system

    SciTech Connect

    B. Bowling; D. Douglas; J. Kewisch; P. Kloeppel; and G. A. Krafft

    1993-12-25

    OLE, the On-Line Envelope program, is a first-order optics code which was designed to provide fast lattice transfer functions from actual accelerator magnet and cavity control values. This paper addresses the results of a successful integration of OLE into the CEBAF control system, TACL. This marriage provides the user with the ability for obtaining real-time Twiss parameters and transfer functions which reflect the current operational state of the machine. The resultant OLE calculation provides the analytical core for many control and diagnostic functions used at CEBAF, including focusing corrections, orbit corrections, emittance measurements, and beamline analysis.

  8. Recent advances in small molecule OLED-on-silicon microdisplays

    NASA Astrophysics Data System (ADS)

    Ghosh, Amalkumar P.; Ali, Tariq A.; Khayrullin, Ilyas; Vazan, Fridrich; Prache, Olivier F.; Wacyk, Ihor

    2009-08-01

    High resolution OLED-on-silicon microdisplay technology is unique and challenging since it requires very small subpixel dimensions (~ 2-5 microns). eMagin's OLED microdisplay is based on white top emitter architecture using small molecule organic materials. The devices are fabricated using high Tg materials. The devices are hermetically sealed with vacuum deposited thin film layers. LCD-type color filters are patterned using photolithography methods to generate primary R, G, B colors. Results of recent improvements in the OLED-on-silicon microdisplay technology, with emphasis on efficiencies, lifetimes, grey scale and CIE color coordinates for SVGA and SXGA resolution microdisplays is presented.

  9. Structure and Biochemical Properties of the Alkene Producing Cytochrome P450 OleTJE (CYP152L1) from the Jeotgalicoccus sp. 8456 Bacterium*

    PubMed Central

    Belcher, James; McLean, Kirsty J.; Matthews, Sarah; Woodward, Laura S.; Fisher, Karl; Rigby, Stephen E. J.; Nelson, David R.; Potts, Donna; Baynham, Michael T.; Parker, David A.; Leys, David; Munro, Andrew W.

    2014-01-01

    The production of hydrocarbons in nature has been documented for only a limited set of organisms, with many of the molecular components underpinning these processes only recently identified. There is an obvious scope for application of these catalysts and engineered variants thereof in the future production of biofuels. Here we present biochemical characterization and crystal structures of a cytochrome P450 fatty acid peroxygenase: the terminal alkene forming OleTJE (CYP152L1) from Jeotgalicoccus sp. 8456. OleTJE is stabilized at high ionic strength, but aggregation and precipitation of OleTJE in low salt buffer can be turned to advantage for purification, because resolubilized OleTJE is fully active and extensively dissociated from lipids. OleTJE binds avidly to a range of long chain fatty acids, and structures of both ligand-free and arachidic acid-bound OleTJE reveal that the P450 active site is preformed for fatty acid binding. OleTJE heme iron has an unusually positive redox potential (−103 mV versus normal hydrogen electrode), which is not significantly affected by substrate binding, despite extensive conversion of the heme iron to a high spin ferric state. Terminal alkenes are produced from a range of saturated fatty acids (C12–C20), and stopped-flow spectroscopy indicates a rapid reaction between peroxide and fatty acid-bound OleTJE (167 s−1 at 200 μm H2O2). Surprisingly, the active site is highly similar in structure to the related P450BSβ, which catalyzes hydroxylation of fatty acids as opposed to decarboxylation. Our data provide new insights into structural and mechanistic properties of a robust P450 with potential industrial applications. PMID:24443585

  10. Silicate-matrix active media for tunable solid-state lasers

    SciTech Connect

    Kuznetsova, Rimma T; Mayer, G V; Manekina, Yu A; Tel'minov, E N; Arabei, S M; Pavich, T A; Solovyov, Konstantin N

    2007-08-31

    The lasing characteristics of solid active media based on laser dyes (rhodamines, coumarin 2, paraterphenyl) doped into silicate bulk matrices and thin films of different compositions are studied upon optical excitation. The lasing efficiency, photostability, and spectral parameters of laser media are investigated as functions of the excitation wavelength and intensity. Variations in these parameters due to the interaction of organic luminophores with a silicate matrix and radiation are discussed. (active media. lasers)

  11. Bacterial lipopolysaccharides induce in vitro degradation of cartilage matrix through chondrocyte activation.

    PubMed Central

    Jasin, H E

    1983-01-01

    The present studies demonstrate that bacterial lipopolysaccharides (LPS) induce cartilage matrix degradation in live explants in organ culture. Quintuplicate bovine nasal fibrocartilage explants cultured for 8 d with three different purified LPS preparations derived from Escherichia coli and Salmonella typhosa at concentrations ranging from 1.0 to 25.0 micrograms/ml resulted in matrix proteoglycan depletion of 33.3 +/- 5.8 to 92.5 +/- 2.0% (medium control depletion 17.7 +/- 0.7 to 32.4 +/- 1.4%). Matrix degradation depended on the presence of live chondrocytes because frozen-thawed explants incubated with LPS failed to show any proteoglycan release. Moreover, the addition of Polymyxin B (25 micrograms/ml) to live explants incubated with LPS abolished matrix release, whereas Polymyxin B had no effect on the matrix-degrading activity provided by blood mononuclear cell factors. A highly purified Lipid A preparation induced matrix degradation at a concentration of 0.01 micrograms/ml. Cartilage matrix collagen and proteoglycan depletion also occurred with porcine articular cartilage explants (collagen release: 18.3 +/- 3.5%, medium control: 2.1 +/- 0.5%; proteoglycan release: 79.0 +/- 5.9%, medium control: 28.8 +/- 4.8%). Histochemical analysis of the cultured explants confirmed the results described above. Gel chromatography of the proteoglycans released in culture indicated that LPS induced significant degradation of the high molecular weight chondroitin sulfate-containing aggregates. These findings suggest that bacterial products may induce cartilage damage by direct stimulation of chondrocytes. This pathogenic mechanism may play a role in joint damage in septic arthritis and in arthropathies resulting from the presence of bacterial products derived from the gastrointestinal tract. Images PMID:6358260

  12. Increased OLED radiative efficiency using a directive optical antenna.

    PubMed

    McDaniel, S; Blair, S

    2010-08-02

    We investigate the improvement in efficiency of organic light emitting diodes/displays (OLEDs) by embedding a typical OLED structure within a metallic patch grating resonator. A patch grating resonator is similar to the more familiar Fabry-Perot resonator, except that one mirror of the resonator is a metallic patch grating with a pitch approximately lambda /2 that reduces lateral propagation of radiative emission. FDTD simulations of the proposed structure indicate a potential 71% increase in emitted power over that of a reference OLED structure, and an additional 5% gain from adding an ITO spacer adjacent to the metallic electrode layer (for a total 76% increase). Implementation of this structure requires little to no modification of the OLED manufacturing process.

  13. Synovial fluid matrix metalloproteinase-2 and -9 activities in dogs suffering from joint disorders.

    PubMed

    Murakami, Kohei; Maeda, Shingo; Yonezawa, Tomohiro; Matsuki, Naoaki

    2016-07-01

    The activity of matrix metalloproteinase (MMP)-2 and MMP-9 in synovial fluids (SF) sampled from dogs with joint disorders was investigated by gelatin zymography and densitometry. Pro-MMP-2 showed similar activity levels in dogs with idiopathic polyarthritis (IPA; n=17) or canine rheumatoid arthritis (cRA; n=4), and healthy controls (n=10). However, dogs with cranial cruciate ligament rupture (CCLR; n=5) presented significantly higher pro-MMP-2 activity than IPA and healthy dogs. Meanwhile, dogs with IPA exhibited significantly higher activity of pro- and active MMP-9 than other groups. Activity levels in pro- and active MMP-9 in cRA and CCLR dogs were not significantly different from those in healthy controls. Different patterns of MMP-2 and MMP-9 activity may reflect the differences in the underlying pathological processes.

  14. Drosophila SAF-B Links the Nuclear Matrix, Chromosomes, and Transcriptional Activity

    PubMed Central

    Alfonso-Parra, Catalina; Maggert, Keith A.

    2010-01-01

    Induction of gene expression is correlated with alterations in nuclear organization, including proximity to other active genes, to the nuclear cortex, and to cytologically distinct domains of the nucleus. Chromosomes are tethered to the insoluble nuclear scaffold/matrix through interaction with Scaffold/Matrix Attachment Region (SAR/MAR) binding proteins. Identification and characterization of proteins involved in establishing or maintaining chromosome-scaffold interactions is necessary to understand how the nucleus is organized and how dynamic changes in attachment are correlated with alterations in gene expression. We identified and characterized one such scaffold attachment factor, a Drosophila homolog of mammalian SAF-B. The large nuclei and chromosomes of Drosophila have allowed us to show that SAF-B inhabits distinct subnuclear compartments, forms weblike continua in nuclei of salivary glands, and interacts with discrete chromosomal loci in interphase nuclei. These interactions appear mediated either by DNA-protein interactions, or through RNA-protein interactions that can be altered during changes in gene expression programs. Extraction of soluble nuclear proteins and DNA leaves SAF-B intact, showing that this scaffold/matrix-attachment protein is a durable component of the nuclear matrix. Together, we have shown that SAF-B links the nuclear scaffold, chromosomes, and transcriptional activity. PMID:20422039

  15. Toll-like receptor 2 activation and serum amyloid A regulate smooth muscle cell extracellular matrix

    PubMed Central

    Bishop, Christopher A.; Best, Michael; Rich, Celeste B.; Stone, Phillip J.

    2017-01-01

    Smooth muscle cells contribute to extracellular matrix remodeling during atherogenesis. De-differentiated, synthetic smooth muscle cells are involved in processes of migration, proliferation and changes in expression of extracellular matrix components, all of which contribute to loss of homeostasis accompanying atherogenesis. Elevated levels of acute phase proteins, including serum amyloid A (SAA), are associated with an increased risk for atherosclerosis. Although infection with periodontal and respiratory pathogens via activation of inflammatory cell Toll-like receptor (TLR)2 has been linked to vascular disease, little is known about smooth muscle cell TLR2 in atherosclerosis. This study addresses the role of SAA and TLR2 activation on smooth muscle cell matrix gene expression and insoluble elastin accumulation. Cultured rat aortic smooth muscle cells were treated with SAA or TLR2 agonists and the effect on expression of matrix metallopeptidase 9 (MMP9) and tropoelastin studied. SAA up-regulated MMP9 expression. Tropoelastin is an MMP9 substrate and decreased tropoelastin levels in SAA-treated cells supported the concept of extracellular matrix remodeling. Interestingly, SAA-induced down-regulation of tropoelastin was not only evident at the protein level but at the level of gene transcription as well. Contributions of proteasomes, nuclear factor κ B and CCAAT/enhancer binding protein β on regulation of MMP9 vs. tropoleastin expression were revealed. Effects on Mmp9 and Eln mRNA expression persisted with long-term SAA treatment, resulting in decreased insoluble elastin accumulation. Interestingly, the SAA effects were TLR2-dependent and TLR2 activation by bacterial ligands also induced MMP9 expression and decreased tropoelastin expression. These data reveal a novel mechanism whereby SAA and/or infection induce changes in vascular elastin consistent with atherosclerosis. PMID:28257481

  16. Activated matrix metalloproteinase and disrupted myocardial collagen matrix in increased sympathetic activity following stimulation of dorsal medulla in the vagotomized feline model.

    PubMed

    Cheng, Ching-Chang; Tung, Kwong-Chung; Fu, Yun-Ching; Gong, Chi-Li; Chen, Ying-Tsung; Lin, Nai-Nu; Lin, James A; Chiu, Yung-Tsung

    2008-02-29

    Sympathetic hyperactivation in many kinds of neurocardiogenic injury can result in obvious heart failure. We generated a vagotomized feline model in which sympathetic hyperactivation was induced by electrical stimulation of dorsal medulla (ESDM) of brain stem to investigate the relationship between disruption of extracellular collagen matrix (ECM) and activation of matrix metalloproteinases (MMPs) in myocardium in the sympathetic hyperactivity. Mean blood pressure, heart rate and plasma norepinephrine were all significantly increased from baseline to a peak at 5 min after ESDM. Echocardiographic study showed significant left ventricular dilatation and hypokinesia (ejection fraction: from 87.7 +/- 6.3% to 39.4 +/- 7.8%) from baseline to 180 mm after ESDM. Histopathological finding revealed significant overstretching or spring-like disappearance and disruption of ECM. MMP-2 expression was significantly increased in left ventricular myocardium as compared to sham. These results suggest that ESDM-induced sympathetic hyperactivity causes the expression of MMP-2 that disrupts myocardial ECM, contributing to the development of cardiac dysfunction.

  17. Communication: Active space decomposition with multiple sites: Density matrix renormalization group algorithm

    SciTech Connect

    Parker, Shane M.; Shiozaki, Toru

    2014-12-07

    We extend the active space decomposition method, recently developed by us, to more than two active sites using the density matrix renormalization group algorithm. The fragment wave functions are described by complete or restricted active-space wave functions. Numerical results are shown on a benzene pentamer and a perylene diimide trimer. It is found that the truncation errors in our method decrease almost exponentially with respect to the number of renormalization states M, allowing for numerically exact calculations (to a few μE{sub h} or less) with M = 128 in both cases. This rapid convergence is because the renormalization steps are used only for the interfragment electron correlation.

  18. Matrix metalloproteinase expression and activity in human airway smooth muscle cells

    PubMed Central

    Elshaw, Shona R; Henderson, Neil; Knox, Alan J; Watson, Susan A; Buttle, David J; Johnson, Simon R

    2004-01-01

    Airway remodelling is a feature of chronic asthma comprising smooth muscle hypertrophy and deposition of extracellular matrix (ECM) proteins. Matrix metalloproteinases (MMPs) breakdown ECM, are involved in tissue remodelling and have been implicated in airway remodelling. Although mesenchymal cells are an important source of MMPs, little data are available on airway smooth muscle (ASM) derived MMPs. We therefore investigated MMP and tissue inhibitor of metalloproteinase (TIMP) production and activity in human ASM cells.MMPs and TIMPs were examined using quantitative real-time RT–PCR, Western blotting, zymography and a quench fluorescence (QF) assay of total MMP activity.The most abundant MMPs were pro-MMP-2, pro- MMP-3, active MMP-3 and MT1-MMP. TIMP-1 and TIMP-2 expression was low in cell lysates but high in conditioned medium. High TIMP secretion was confirmed by the ability of ASM-conditioned medium to inhibit recombinant MMP-2 in a QF assay. Thrombin increased MMP activity by activation of pro-MMP-2 independent of the conventional smooth muscle thrombin receptors PAR 1 and 4.In conclusion, ASM cells express pro-MMP-2, pro and active MMP-3, MMP-9 and MT1-MMP. Unstimulated cells secrete excess TIMP 1 and 2, preventing proteolytic activity. MMP-2 can be activated by thrombin which may contribute to airway remodelling. PMID:15265805

  19. Activation of matrix metalloproteinase-2 from hepatic stellate cells requires interactions with hepatocytes.

    PubMed Central

    Théret, N.; Musso, O.; L'Helgoualc'h, A.; Clément, B.

    1997-01-01

    Activation of matrix metalloproteinase (MMP)-2, the 72-kd collagenase IV/gelatinase A, is involved in extracellular matrix remodeling. It has been suggested that a membrane-type MMP (MT-MMP-1) and the tissue inhibitor of metalloproteinase (TIMP)-2 are involved in MMP-2 processing, but the exact mechanism(s) of its activation remains unclear. We have investigated the role of cell-cell cooperation in the activation of pro-MMP-2 in the liver, using pure cultures and co-cultures of hepatocytes and hepatic stellate cells (HSCs). Northern blot analysis and in situ hybridization showed that, in both pure and co-cultures, HSCs, but not hepatocytes, expressed MMP-2, TIMP-2, and MT-MMP-1 mRNA. Zymography analyses revealed the latent form of MMP-2 in medium from 2-day-old pure HSC cultures with higher amounts in medium from hepatocyte/HSC co-cultures. When hepatocytes were added to 10-day-old HSC cultures, the activated form of MMP-2 was detected, concomitantly with the deposition of an abundant extracellular matrix. Incubation of plasma membrane-enriched fractions from hepatocytes with conditioned medium from pure HSC cultures generated the activated species of MMP-2 (62 and 59 kd). Activation of pro-MMP-2 by hepatocyte membranes was inhibited by EDTA, heat, and trypsin but not by serine proteinase inhibitors. These data show that the co-expression of TIMP-2, MMP-2, and MT-MMP-1 by HSCs does not lead to secretion of the activated form of MMP-2. Hepatocytes, which do not express MMP-2, TIMP-2, or MT-MMP-1, induce MMP-2 activation through a plasma membrane-dependent mechanism(s), thus suggesting that cell-cell interactions are involved in this process in vivo. Images Figure 1 Figure 2 Figure 3 PMID:9006321

  20. Neural conversion of ES cells by an inductive activity on human amniotic membrane matrix

    PubMed Central

    Ueno, Morio; Matsumura, Michiru; Watanabe, Kiichi; Nakamura, Takahiro; Osakada, Fumitaka; Takahashi, Masayo; Kawasaki, Hiroshi; Kinoshita, Shigeru; Sasai, Yoshiki

    2006-01-01

    Here we report a human-derived material with potent inductive activity that selectively converts ES cells into neural tissues. Both mouse and human ES cells efficiently differentiate into neural precursors when cultured on the matrix components of the human amniotic membrane in serum-free medium [amniotic membrane matrix-based ES cell differentiation (AMED)]. AMED-induced neural tissues have regional characteristics (brainstem) similar to those induced by coculture with mouse PA6 stromal cells [a common method called stromal cell-derived inducing activity (SDIA) culture]. Like the SDIA culture, the AMED system is applicable to the in vitro generation of various CNS tissues, including dopaminergic neurons, motor neurons, and retinal pigment epithelium. In contrast to the SDIA method, which uses animal cells, the AMED culture uses a noncellular inductive material derived from an easily available human tissue; therefore, AMED should provide a more suitable and versatile system for generating a variety of neural tissues for clinical applications. PMID:16766664

  1. Flexible transistor active matrix array with all screen-printed electrodes

    NASA Astrophysics Data System (ADS)

    Peng, Boyu; Lin, Jiawei; Chan, Paddy K. L.

    2013-09-01

    Flexible transistor active matrix array is fabricated on PEN substrate using all screen-printed gate, source and drain electrodes. Parylene-C and DNTT act as gate dielectric layer and semiconductor, respectively. The transistor possesses high mobility (0.33 cm2V-1 s-1), large on/off ratio (< 106) and low leakage current (~10 pA). Active matrix array consists of 10×10 transistors were demonstrated. Transistors exhibited average mobility of 0.29 cm2V-1s-1 and on/off ratio larger than 104 in array form. In the transistor array, we achieve 75μm channel length and a size of 2 mm × 2 mm for each element in the array which indicates the current screen-printing method has large potential in large-area circuits and display applications.

  2. TOPICAL REVIEW: Organic light-emitting devices (OLEDs) and OLED-based chemical and biological sensors: an overview

    NASA Astrophysics Data System (ADS)

    Shinar, Joseph; Shinar, Ruth

    2008-07-01

    The basic photophysics, transport properties, state of the art, and challenges in OLED science and technology, and the major developments in structurally integrated OLED-based luminescent chemical and biological sensors are reviewed briefly. The dramatic advances in OLED performance have resulted in devices with projected continuous operating lifetimes of ~2 × 105 h (~23 yr) at ~150 Cd m-2 (the typical brightness of a computer monitor or TV). Consequently, commercial products incorporating OLEDs, e.g., cell phones, MP3 players, and, most recently, OLED TVs, are rapidly proliferating. The progress in elucidating the photophysics and transport properties, occurring in tandem with the development of OLEDs, has been no less dramatic. It has resulted in a detailed understanding of the dynamics of trapped and mobile negative and positive polarons (to which the electrons and holes, respectively, relax upon injection), and of singlet and triplet excitons. It has also yielded a detailed understanding of the spin dynamics of polarons and triplet excitons, which affects their overall dynamics significantly. Despite the aforementioned progress, there are outstanding challenges in OLED science and technology, notably in improving the efficiency of the devices and their stability at high brightness (>1000 Cd m-2). One of the most recent emerging OLED-based technologies is that of structurally integrated photoluminescence-based chemical and biological sensors. This sensor platform, pioneered by the authors, yields uniquely simple and potentially very low-cost sensor (micro)arrays. The second part of this review describes the recent developments in implementing this platform for gas phase oxygen, dissolved oxygen (DO), anthrax lethal factor, and hydrazine sensors, and for a DO, glucose, lactate, and ethanol multianalyte sensor.

  3. Structurally Integrated Photoluminescence-Based Lactate Sensor Using Organic Light Emitting Devices (OLEDs) as the Light Source

    SciTech Connect

    Qian, Chengliang

    2006-01-01

    Multianalyte bio(chemical) sensors are extensively researched for monitoring analytes in complex systems, such as blood serum. As a step towards developing such multianalyte sensors, we studied a novel, structurally integrated, organic light emitting device (OLED)-based sensing platform for detection of lactate. Lactate biosensors have attracted numerous research efforts, due to their wide applications in clinical diagnosis, athletic training and food industry. The OLED-based sensor is based on monitoring the oxidation reaction of lactate, which is catalyzed by the lactate oxidase (LOX) enzyme. The sensing component is based on an oxygen-sensitive dye, Platinum octaethyl porphyrin (PtOEP), whose photoluminescence (PL) lifetime τ decreases as the oxygen level increases. The PtOEP dye was embedded in a thin film polystyrene (PS) matrix; the LOX was dissolved in solution or immobilized in a sol-gel matrix. τ was measured as a function of the lactate concentration; as the lactate concentration increases, τ increases due to increased oxygen consumption. The sensors performance is discussed in terms of the detection sensitivity, dynamic range, and response time. A response time of ~32 sec was achieved when the LOX was dissolved in solution and kept in a closed cell. Steps towards development of a multianalyte sensor array using an array of individually addressable OLED pixels were also presented.

  4. Notch modulates VEGF action in endothelial cells by inducing Matrix Metalloprotease activity

    PubMed Central

    2011-01-01

    Background In the vasculature, Notch signaling functions as a downstream effecter of Vascular Endothelial Growth Factor (VEGF) signaling. VEGF regulates sprouting angiogenesis in part by inducing and activating matrix metalloproteases (MMPs). This study sought to determine if VEGF regulation of MMPs was mediated via Notch signaling and to determine how Notch regulation of MMPs influenced endothelial cell morphogenesis. Methods and Results We assessed the relationship between VEGF and Notch signaling in cultured human umbilical vein endothelial cells. Overexpression of VEGF-induced Notch4 and the Notch ligand, Dll4, activated Notch signaling, and altered endothelial cell morphology in a fashion similar to that induced by Notch activation. Expression of a secreted Notch antagonist (Notch1 decoy) suppressed VEGF-mediated activation of endothelial Notch signaling and endothelial morphogenesis. We demonstrate that Notch mediates VEGF-induced matrix metalloprotease activity via induction of MMP9 and MT1-MMP expression and activation of MMP2. Introduction of a MMP inhibitor blocked Notch-mediated endothelial morphogenesis. In mice, analysis of VEGF-induced dermal angiogenesis demonstrated that the Notch1 decoy reduced perivascular MMP9 expression. Conclusions Taken together, our data demonstrate that Notch signaling can act downstream of VEGF signaling to regulate endothelial cell morphogenesis via induction and activation of specific MMPs. In a murine model of VEGF-induced dermal angiogenesis, Notch inhibition led to reduced MMP9 expression. PMID:21349159

  5. Novel Smart Windows Based on Transparent Phosphorescent OLEDs

    SciTech Connect

    Brian D'Andrade; Stephen Forest

    2006-09-15

    In this program, Universal Display Corporation (UDC) and Princeton University developed the use of white transparent phosphorescent organic light emitting devices (PHOLEDs{trademark}) to make low-cost ''transparent OLED (TOLED) smart windows'', that switch rapidly from being a highly efficient solid-state light source to being a transparent window. PHOLEDs are ideal for large area devices, and the UDC-Princeton team has demonstrated white PHOLEDs with efficiencies of >24 lm/W at a luminance of 1,000 cd/m{sup 2}. TOLEDs have transparencies >70% over the visible wavelengths of light, but their transparency drops to less than 5% for wavelengths shorter than 350 nm, so they can also be used as ultraviolet (UV) light filters. In addition to controlling the flow of UV radiation, TOLEDs coupled with an electromechanical or electrically activated reflecting shutter on a glass window can be employed to control the flow of heat from infrared (IR) radiation by varying the reflectance/transparency of the glass for wavelengths greater than 800nm. One particularly attractive shutter technology is reversible electrochromic mirrors (REM). Our goal was therefore to integrate two innovative concepts to meet the U.S. Department of Energy goals: high power efficiency TOLEDs, plus electrically controlled reflectors to produce a ''smart window''. Our efforts during this one year program have succeeded in producing a prototype smart window shown in the Fig. I, below. The four states of the smart window are pictured: reflective with lamp on, reflective with lamp off, transparent with lamp on, and transparent with lamp off. In the transparent states, the image is an outdoor setting viewed through the window. In the reflective states, the image is an indoor setting viewed via reflection off the window. We believe that the integration of our high efficiency white phosphorescent TOLED illumination source, with electrically activated shutters represents an innovative low-cost approach to

  6. Implementation of advanced matrix corrections for active interrogation of waste drums using the CTEN instrument

    SciTech Connect

    Melton, S.; Estep, R.; Hollas, C.

    1998-12-31

    The combined thermal/epithermal neutron instrument (CTEN) was designed at Los Alamos to improve measurement accuracy and mitigate self shielding effects inherent in the differential dieaway technique (DDT). A major goal in this research effort has been the development of a calibration technique that incorporates recently developed matrix and self-shielding corrections using data generated from additional detectors and new acquisition techniques. A comprehensive data set containing both active and passive measurements was generated using 26 different matrices and comprising a total of 1,400 measurements. In all, 31 flux-and-matrix-dependent parameters, 24 positional parameters, two dieaway times, and a correlated ratio were determined from each of the over 1,400 measurements. A reduced list of matrix indicators, prioritized using the alternating conditional expectation (ACE) algorithm, was used to train a neural network using a generalized regression technique (GRNN) to determine matrix- and position-corrected calibration factors. This paper describes the experimental, analytical, and empirical techniques used to determine the corrected calibration factor for an unknown waste drum. Results from a range of cases are compared with those obtained using a mobile DDT instrument and traditional DDT algorithms.

  7. Matrix stiffness modulates formation and activity of neuronal networks of controlled architectures.

    PubMed

    Lantoine, Joséphine; Grevesse, Thomas; Villers, Agnès; Delhaye, Geoffrey; Mestdagh, Camille; Versaevel, Marie; Mohammed, Danahe; Bruyère, Céline; Alaimo, Laura; Lacour, Stéphanie P; Ris, Laurence; Gabriele, Sylvain

    2016-05-01

    The ability to construct easily in vitro networks of primary neurons organized with imposed topologies is required for neural tissue engineering as well as for the development of neuronal interfaces with desirable characteristics. However, accumulating evidence suggests that the mechanical properties of the culture matrix can modulate important neuronal functions such as growth, extension, branching and activity. Here we designed robust and reproducible laminin-polylysine grid micropatterns on cell culture substrates that have similar biochemical properties but a 100-fold difference in Young's modulus to investigate the role of the matrix rigidity on the formation and activity of cortical neuronal networks. We found that cell bodies of primary cortical neurons gradually accumulate in circular islands, whereas axonal extensions spread on linear tracks to connect circular islands. Our findings indicate that migration of cortical neurons is enhanced on soft substrates, leading to a faster formation of neuronal networks. Furthermore, the pre-synaptic density was two times higher on stiff substrates and consistently the number of action potentials and miniature synaptic currents was enhanced on stiff substrates. Taken together, our results provide compelling evidence to indicate that matrix stiffness is a key parameter to modulate the growth dynamics, synaptic density and electrophysiological activity of cortical neuronal networks, thus providing useful information on scaffold design for neural tissue engineering.

  8. NMR solution structure of Ole e 6, a major allergen from olive tree pollen.

    PubMed

    Treviño, Miguel Angel; García-Mayoral, María Flor; Barral, Patricia; Villalba, Mayte; Santoro, Jorge; Rico, Manuel; Rodríguez, Rosalía; Bruix, Marta

    2004-09-10

    Ole e 6 is a pollen protein from the olive tree (Olea europaea) that exhibits allergenic activity with a high prevalence among olive-allergic individuals. The three-dimensional structure of Ole e 6 has been determined in solution by NMR methods. This is the first experimentally determined structure of an olive tree pollen allergen. The structure of this 50-residue protein is based on 486 upper limit distance constraints derived from nuclear Overhauser effects and 24 torsion angle restraints. The global fold of Ole e 6 consists of two nearly antiparallel alpha-helices, spanning residues 3-19 and 23-33, that are connected by a short loop and followed by a long, unstructured C-terminal tail. Viewed edge-on, the structured N terminus has a dumbbell-like shape with the two helices on the outside and with the hydrophobic core, mainly composed of 3 aromatic and 6 cysteine residues, on the inside. All the aromatic rings lie on top of and pack against the three disulfide bonds. The lack of thermal unfolding, even at 85 degrees C, indicates a high conformational stability. Based on the analysis of the molecular surface, we propose five plausible epitopes for IgE recognition. The results presented here provide the structural foundation for future experiments to verify the antigenicity of the proposed epitopes, as well as to design novel hypoallergenic forms of the protein suitable for diagnosis and treatment of type-I allergies. In addition, three-dimensional structure features of Ole e 6 are discussed to provide a basis for future functional studies.

  9. Ole e 3, an olive-tree allergen, belongs to a widespread family of pollen proteins.

    PubMed

    Batanero, E; Villalba, M; Ledesma, A; Puente, X S; Rodríguez, R

    1996-11-01

    An allergen has been isolated from a saline extract of olive tree (Olea europaea) pollen. The protein consists of a single polypeptide chain of 9.2-kDa, as determined by mass spectrometry. It contains neither tryptophan nor tyrosine residues, and displays an acidic isoelectric point. The secondary structure of the protein, estimated from the analysis of the circular-dichroism spectrum in the peptide-bond region, is composed of 52% alpha-helix, 10% beta-strand, 29% beta-turn and 9% non-regular conformation. The N-terminal end of the protein is blocked. Amino-acid-sequence data have been obtained from peptides produced by CNBr treatment of the native allergen. A partial sequence of 36 amino acids has thus been elucidated. The protein exhibits sequence similarity with pollen allergens from Brassica species and contains a Ca(2+)-binding motif. The isolated protein displays IgE-binding activity against sera of patients allergic to olive-tree pollen. It has been named Ole e 3, according to the recommendations of the IUIS Nomenclature Committee. IgG ELISA inhibition assays with polyclonal antibodies specific for Ole e 3 reveal the presence of proteins similar to Ole e 3 in the pollen from non-related plant species, which may explain allergic cross-reactivity processes.

  10. Investigation on a short circuit of large-area OLED lighting panels

    NASA Astrophysics Data System (ADS)

    Park, J. W.; Kim, T. W.; Park, J. B.

    2013-04-01

    A short circuit often arises from large-area organic light-emitting device (OLED) lighting panels due to particles (i.e. dust, organic or metal debris) or the spike-like surface of the indium-tin-oxide (ITO) anode. On the emergence of a short circuit, an instant current crowding occurs, thereby reducing substantially the resistance of the panels and causing a failure of a dimming control. In this paper, we investigate the effect of the surface morphology of ITO on the resistance and dimmability of the panels. We have demonstrated that the peak-to-valley roughness of ITO should be much less than 20 nm or the resistance of the panels should be much higher than 1 MΩ in order to avoid an unwanted short-circuit phenomenon and thus achieve the high-yield fabrication of OLED lighting panels. It is also addressed that much care is taken to ensure a dimming control of OLED lighting panels with a larger active area because the resistance of those panels varies depending more sensitively on the surface roughness of ITO.

  11. Ulex europaeus I lectin induces activation of matrix-metalloproteinase-2 in endothelial cells.

    PubMed

    Gomez, D E; Yoshiji, H; Kim, J C; Thorgeirsson, U P

    1995-11-02

    In this report, we show that the lectin Ulex europaeus agglutinin I (UEA I), which binds to alpha-linked fucose residues on the surface of endothelial cells, mediates activation of the 72-kDa matrix metalloproteinase-2 (MMP-2). A dose-dependent increase in the active 62-kDa form of MMP-2 was observed in conditioned medium from monkey aortic endothelial cells (MAEC) following incubation with concentrations of UEA I ranging from 2 to 100 micrograms/ml. The increase in the 62-kDa MMP-2 gelatinolytic activity was not reflected by a rise in MMP-2 gene expression. The UEA I-mediated activation of MMP-2 was blocked by L-fucose, which competes with UEA I for binding to alpha-fucose. These findings may suggest that a similar in vivo mechanism exists, whereby adhesive interactions between tumor cell lectins and endothelial cells can mediate MMP-2 activation.

  12. Functionalized mesoporous silica films as a matrix for anchoring electrochemically active guests.

    PubMed

    Fattakhova Rohlfing, Dina; Rathouský, Jirí; Rohlfing, Yven; Bartels, Oliver; Wark, Michael

    2005-11-22

    Mesoporous silica thin films were shown to be an appropriate matrix for immobilization of discrete electroactive moieties, yielding uniform transparent thin film electrodes with defined texture and enhanced electrochemical activity. The mesoporous silica films prepared on conducting FTO-coated glass substrate were postsynthetically functionalized. Alkoxysilanes were used as precursors for subsequent grafting via ionic or covalent bonds of representative electroactive species, such as polyoxometalate PMo12O(40)3-, hexacyanoferrate(III), and ferrocene. The electrochemically active concentration within the silica-based composite electrodes achieves 90, 260, and 60 micromol cm(-3) for polyoxometalate, hexacyanoferrate(III), and ferrocene, respectively. The amount of molecules involved in the charge-transfer sequence is proportional to the film thickness and comparable to the total amount of embedded guests. Thus, eventually the whole bulk volume of the modified silica films is electrochemically accessible. Immobilization in the chemically modified silica matrix alters the redox potential of the electroactive molecules. Electron exchange between the adjacent redox centers (electron hopping) is proposed as a possible charge propagation pathway through the insulating silica matrix, which is supported by the fact that the high charge uptake is observed also for the hybrid electrodes with the covalently anchored redox guests.

  13. Near Infrared Optical Proteolytic Beacons for In Vivo Imaging of Matrix Metalloproteinase Activity

    PubMed Central

    McIntyre, J. Oliver; Scherer, Randy L.; Matrisian, Lynn M.

    2010-01-01

    The exuberant expression of proteinases by tumor cells has long been associated with the breakdown of the extracellular matrix, tumor invasion, and metastasis to distant organs. There is both epidemiological and experimental data that support a causative role for proteinases of the matrix metalloproteinase (MMP) family in tumor progression. Optical imaging techniques provide an extraordinary opportunity for non-invasive “molecular imaging” of tumor-associated proteolytic activity. The application of optical proteolytic beacons for the detection of specific proteinase activities associated with tumors has several potential purposes: 1) Detection of small, early-stage tumors with increased sensitivity due to the catalytic nature of proteolytic activity, 2) Diagnosis and Prognosis to distinguished tumors that require particularly aggressive therapy or those that will not benefit from therapy, 3) Identification of tumors appropriate for specific anti-proteinase therapeutics and optimization of drug and dose based on determination of target modulation, and 4) as an indicator of efficacy of proteolytically-activated pro-drugs. This chapter describes the synthesis, characterization, and application of reagents that use visible and near infrared fluorescence resonance energy transfer (FRET) fluorophore pairs to detect and measure MMP-referable proteolytic activity in tumors in mouse models of cancer. PMID:20135290

  14. RNase L Suppresses Androgen Receptor Signaling, Cell Migration and Matrix Metalloproteinase Activity in Prostate Cancer Cells.

    PubMed

    Dayal, Shubham; Zhou, Jun; Manivannan, Praveen; Siddiqui, Mohammad Adnan; Ahmad, Omaima Farid; Clark, Matthew; Awadia, Sahezeel; Garcia-Mata, Rafael; Shemshedini, Lirim; Malathi, Krishnamurthy

    2017-03-01

    The interferon antiviral pathways and prostate cancer genetics converge on a regulated endoribonuclease, RNase L. Positional cloning and linkage studies mapped Hereditary Prostate Cancer 1 (HPC1) to RNASEL. To date, there is no correlation of viral infections with prostate cancer, suggesting that RNase L may play additional roles in tumor suppression. Here, we demonstrate a role of RNase L as a suppressor of androgen receptor (AR) signaling, cell migration and matrix metalloproteinase activity. Using RNase L mutants, we show that its nucleolytic activity is dispensable for both AR signaling and migration. The most prevalent HPC1-associated mutations in RNase L, R462Q and E265X, enhance AR signaling and cell migration. RNase L negatively regulates cell migration and attachment on various extracellular matrices. We demonstrate that RNase L knockdown cells promote increased cell surface expression of integrin β1 which activates Focal Adhesion Kinase-Sarcoma (FAK-Src) pathway and Ras-related C3 botulinum toxin substrate 1-guanosine triphosphatase (Rac1-GTPase) activity to increase cell migration. Activity of matrix metalloproteinase (MMP)-2 and -9 is significantly increased in cells where RNase L levels are ablated. We show that mutations in RNase L found in HPC patients may promote prostate cancer by increasing expression of AR-responsive genes and cell motility and identify novel roles of RNase L as a prostate cancer susceptibility gene.

  15. The inhibition of matrix metalloproteinase activity in chronic wounds by a polyacrylate superabsorber.

    PubMed

    Eming, Sabine; Smola, Hans; Hartmann, Berenike; Malchau, Gebhart; Wegner, Ronny; Krieg, Thomas; Smola-Hess, Sigrun

    2008-07-01

    Excessive matrix metalloproteinase (MMP) levels have been observed in wound fluid of impaired healing wounds. This is thought to interfere with granulation tissue formation as newly formed extracellular matrix and cytokines are degraded and the wound becomes deadlocked, unable to progress to the next healing stages. In the cleansing phase, associated with high MMP activity levels, hydroactive wound dressings containing polyacrylate superabsorber particles are particularly effective. We tested whether these particles can block MMP activity in wound fluid obtained from chronic venous leg ulcers. Polyacrylate superabsorber particles inhibited MMP activity by more than 87% in a fluorogenic peptide substrate assay. Further analysis revealed two underlying molecular mechanisms. First, experiments showed direct binding of MMPs to the particles. Secondly, polyacrylate superabsorber particles can bind Ca2+ and Zn2+ ions competing with MMPs for divalent ions required for enzymatic activity. Furthermore, we provide the first evidence in vivo that MMPs bind effectively to polyacrylate superabsorber particles within the hostile environment of chronic wounds. We conclude that polyacrylate superabsorber particles can rescue the highly proteolytic microenvironment of non-healing wounds from MMP activity so that more conductive conditions allow healing to proceed.

  16. RNase L Suppresses Androgen Receptor Signaling, Cell Migration and Matrix Metalloproteinase Activity in Prostate Cancer Cells

    PubMed Central

    Dayal, Shubham; Zhou, Jun; Manivannan, Praveen; Siddiqui, Mohammad Adnan; Ahmad, Omaima Farid; Clark, Matthew; Awadia, Sahezeel; Garcia-Mata, Rafael; Shemshedini, Lirim; Malathi, Krishnamurthy

    2017-01-01

    The interferon antiviral pathways and prostate cancer genetics converge on a regulated endoribonuclease, RNase L. Positional cloning and linkage studies mapped Hereditary Prostate Cancer 1 (HPC1) to RNASEL. To date, there is no correlation of viral infections with prostate cancer, suggesting that RNase L may play additional roles in tumor suppression. Here, we demonstrate a role of RNase L as a suppressor of androgen receptor (AR) signaling, cell migration and matrix metalloproteinase activity. Using RNase L mutants, we show that its nucleolytic activity is dispensable for both AR signaling and migration. The most prevalent HPC1-associated mutations in RNase L, R462Q and E265X, enhance AR signaling and cell migration. RNase L negatively regulates cell migration and attachment on various extracellular matrices. We demonstrate that RNase L knockdown cells promote increased cell surface expression of integrin β1 which activates Focal Adhesion Kinase-Sarcoma (FAK-Src) pathway and Ras-related C3 botulinum toxin substrate 1-guanosine triphosphatase (Rac1-GTPase) activity to increase cell migration. Activity of matrix metalloproteinase (MMP)-2 and -9 is significantly increased in cells where RNase L levels are ablated. We show that mutations in RNase L found in HPC patients may promote prostate cancer by increasing expression of AR-responsive genes and cell motility and identify novel roles of RNase L as a prostate cancer susceptibility gene. PMID:28257035

  17. New matrix polymers for photo-activated resin composites using di-alpha-fluoroacrylic acid derivatives.

    PubMed

    Kurata, Shigeaki; Yamazaki, Noboru

    2008-07-01

    A novel matrix resin for photo-activated resin composites was developed using alpha-fluoroacrylic acid derivatives. To render resin composites with improved mechanical properties, silica fillers were also used. It was found that the newly developed fluorine-substituted monomer was polymerized quite easily not only by free radical chemical initiators, but also by photoirradiation using free radical photoinitiator system. In particular, the photopolymerization rate of the novel monomer was more than two times faster than that of corresponding methacrylate-based monomer. Composite based on the newly developed matrix resin had higher micro-Vickers hardness and compressive strength values than the methacrylate-based composite, and that it contained only trace residual monomers compared with the methacrylate-based material. The high polymerization conversion of the fluorine-substituted monomer could be attributed to the polar effect or the small steric hindrance of fluorine at the alpha-position.

  18. High Quantum Efficiency OLED Lighting Systems

    SciTech Connect

    Shiang, Joseph

    2011-09-30

    The overall goal of the program was to apply improvements in light outcoupling technology to a practical large area plastic luminaire, and thus enable the product vision of an extremely thin form factor high efficiency large area light source. The target substrate was plastic and the baseline device was operating at 35 LPW at the start of the program. The target LPW of the program was a >2x improvement in the LPW efficacy and the overall amount of light to be delivered was relatively high 900 lumens. Despite the extremely difficult challenges associated with scaling up a wet solution process on plastic substrates, the program was able to make substantial progress. A small molecule wet solution process was successfully implemented on plastic substrates with almost no loss in efficiency in transitioning from the laboratory scale glass to large area plastic substrates. By transitioning to a small molecule based process, the LPW entitlement increased from 35 LPW to 60 LPW. A further 10% improvement in outcoupling efficiency was demonstrated via the use of a highly reflecting cathode, which reduced absorptive loss in the OLED device. The calculated potential improvement in some cases is even larger, ~30%, and thus there is considerable room for optimism in improving the net light coupling efficacy, provided absorptive loss mechanisms are eliminated. Further improvements are possible if scattering schemes such as the silver nanowire based hard coat structure are fully developed. The wet coating processes were successfully scaled to large area plastic substrate and resulted in the construction of a 900 lumens luminaire device.

  19. Synthesis of hydroxypyrone- and hydroxythiopyrone-based matrix metalloproteinase inhibitors: Developing a structure–activity relationship

    PubMed Central

    Yan, Yi-Long; Miller, Melissa T.; Cao, Yuchen; Cohen, Seth M.

    2010-01-01

    The zinc(II)-dependent matrix metalloproteinases (MMPs) are associated with a variety of diseases. Development of inhibitors to modulate MMP activity has been an active area of investigation for therapeutic development. Hydroxypyrones and hydroxythiopyrones are alternative zinc-binding groups (ZBGs) that, when combined with peptidomimetic backbones, comprise a novel class of MMP inhibitors (MMPi). In this report, a series of hydroxypyrone- and hydroxythiopyrone-based MMPi with aryl backbones at the 2-, 5-, and 6-positions of the hydroxypyrone ring have been synthesized. Synthetic routes for developing inhibitors with substituents at two of these positions (so-called double-handed inhibitors) are also explored. The MMP inhibition profiles and structure–activity relationship of synthesized hydroxypyrones and hydroxythiopyrones have been analyzed. The results here show that the ZBG, the position of the backbone on the ZBG, and the nature of the linker between the ZBG and backbone are critical for MMPi activities. PMID:19261472

  20. AMPK activity regulates trafficking of mitochondria to the leading edge during cell migration and matrix invasion

    PubMed Central

    Cunniff, Brian; McKenzie, Andrew J.; Heintz, Nicholas H.; Howe, Alan K.

    2016-01-01

    Cell migration is a complex behavior involving many energy-expensive biochemical events that iteratively alter cell shape and location. Mitochondria, the principal producers of cellular ATP, are dynamic organelles that fuse, divide, and relocate to respond to cellular metabolic demands. Using ovarian cancer cells as a model, we show that mitochondria actively infiltrate leading edge lamellipodia, thereby increasing local mitochondrial mass and relative ATP concentration and supporting a localized reversal of the Warburg shift toward aerobic glycolysis. This correlates with increased pseudopodial activity of the AMP-activated protein kinase (AMPK), a critically important cellular energy sensor and metabolic regulator. Furthermore, localized pharmacological activation of AMPK increases leading edge mitochondrial flux, ATP content, and cytoskeletal dynamics, whereas optogenetic inhibition of AMPK halts mitochondrial trafficking during both migration and the invasion of three-dimensional extracellular matrix. These observations indicate that AMPK couples local energy demands to subcellular targeting of mitochondria during cell migration and invasion. PMID:27385336

  1. Heart failure alters matrix metalloproteinase gene expression and activity in rat skeletal muscle.

    PubMed

    Carvalho, Robson Francisco; Dariolli, Rafael; Justulin Junior, Luis Antonio; Sugizaki, Mário Mateus; Politi Okoshi, Marina; Cicogna, Antonio Carlos; Felisbino, Sérgio Luis; Dal Pai-Silva, Maeli

    2006-12-01

    Heart failure is associated with a skeletal muscle myopathy with cellular and extracellular alterations. The hypothesis of this investigation is that extracellular changes may be associated with enhanced mRNA expression and activity of matrix metalloproteinases (MMP). We examined MMP mRNA expression and MMP activity in Soleus (SOL), extensor digitorum longus (EDL), and diaphragm (DIA) muscles of young Wistar rat with monocrotaline-induced heart failure. Rats injected with saline served as age-matched controls. MMP2 and MMP9 mRNA contents were determined by RT-PCR and MMP activity by electrophoresis in gelatin-containing polyacrylamide gels in the presence of SDS under non-reducing conditions. Heart failure increased MMP9 mRNA expression and activity in SOL, EDL and DIA and MMP2 mRNA expression in DIA. These results suggest that MMP changes may contribute to the skeletal muscle myopathy during heart failure.

  2. OLED lighting: light where it never has been before

    NASA Astrophysics Data System (ADS)

    Klein, M.; Heuser, K.; Schindler, F.; Krummacher, B.; Dobbertin, T.; Pätzold, R.; Gärditz, C.

    2007-02-01

    "Optical Technologies have conquered the world" - their economic key data showed an impressive growth in the past couple of years, and the predictions for the up-coming years keep the expectations high 1, 2. In the case of OLED (Organic Light Emitting Diode) lighting, e.g. IDTechEx is predicting a worldwide market growth from 50 million USD in 2009 to 3.3 billion USD in 2012 3. LED and OLED technology, although both being referred to as solid state lighting, are rather complementary in their characteristics. Whereas LEDs are high efficient point light sources, OLEDs cover large area, diffuse lighting applications which can follow the increased awareness for creation of personalized atmosphere. Ambience and mood lighting can be perfectly realized by the means of OLED large area illumination which will pave the way for applications that up to now could not have been realized. OLED lighting technology rests on three pillars at the same time, the basic performance like efficiency and lifetime, the unique features, and costs. These key challenges and their impact on various applications will be discussed.

  3. Analysis of current driving capability of pentacene TFTs for OLEDs

    NASA Astrophysics Data System (ADS)

    Ryu, Gi Seong; Byun, Hyun Sook; Xu, Yong Xian; Pyo, Kyung Soo; Choe, Ki Beom; Song, Chung Kun

    2005-01-01

    The flexible display and the application of Roll-To-Roll process is difficult because high temperature process of a-Si;H TFT and poly-Si TFT limited the use of plastic substrate. We proposed AMOLED using Pentacene TFT (OTFT) to fabricate flexible display. The first stage for OTFT application to OLED, we analyzed OTFT as driving device of OLED. The process performed on glass and plastic (PET) substrate that is coated ITO and PVP is used for gate insulator. The field effect mobility of the fabricated OTFT is 0.1~0.3cm2/V"sec and Ion/Ioff current ratio is 103~105. OLED is fabricated with two stories structure of TPD and Alq3, and we can observe the light at 5V by the naked eye. The wavelength of observed lights is 530nm ~550nm. We can confirm the driving of OLED due to OTFT using Test panel and observe OLED control by gate voltage of OTFT. Also, we verify designed structure and process, and make a demonstration fabricating 64 by 64 backplane based on Test panel.

  4. Thin Film Packaging Solutions for High Efficiency OLED Lighting Products

    SciTech Connect

    2008-06-30

    The objective of the 'Thin Film Packaging Solutions for High Efficiency OLED Lighting Products' project is to demonstrate thin film packaging solutions based on SiC hermetic coatings that, when applied to glass and plastic substrates, support OLED lighting devices by providing longer life with greater efficiency at lower cost than is currently available. Phase I Objective: Demonstrate thin film encapsulated working phosphorescent OLED devices on optical glass with lifetime of 1,000 hour life, CRI greater than 75, and 15 lm/W. Phase II Objective: Demonstrate thin film encapsulated working phosphorescent OLED devices on plastic or glass composite with 25 lm/W, 5,000 hours life, and CRI greater than 80. Phase III Objective: Demonstrate 2 x 2 ft{sup 2} thin film encapsulated working phosphorescent OLED with 40 lm/W, 10,000 hour life, and CRI greater than 85. This report details the efforts of Phase III (Budget Period Three), a fourteen month collaborative effort that focused on optimization of high-efficiency phosphorescent OLED devices and thin-film encapsulation of said devices. The report further details the conclusions and recommendations of the project team that have foundation in all three budget periods for the program. During the conduct of the Thin Film Packaging Solutions for High Efficiency OLED Lighting Products program, including budget period three, the project team completed and delivered the following achievements: (1) a three-year marketing effort that characterized the near-term and longer-term OLED market, identified customer and consumer lighting needs, and suggested prototype product concepts and niche OLED applications lighting that will give rise to broader market acceptance as a source for wide area illumination and energy conservation; (2) a thin film encapsulation technology with a lifetime of nearly 15,000 hours, tested by calcium coupons, while stored at 16 C and 40% relative humidity ('RH'). This encapsulation technology was characterized

  5. Substrate Trapping in Crystals of the Thiolase OleA Identifies Three Channels That Enable Long Chain Olefin Biosynthesis.

    PubMed

    Goblirsch, Brandon R; Jensen, Matthew R; Mohamed, Fatuma A; Wackett, Lawrence P; Wilmot, Carrie M

    2016-12-23

    Phylogenetically diverse microbes that produce long chain, olefinic hydrocarbons have received much attention as possible sources of renewable energy biocatalysts. One enzyme that is critical for this process is OleA, a thiolase superfamily enzyme that condenses two fatty acyl-CoA substrates to produce a β-ketoacid product and initiates the biosynthesis of long chain olefins in bacteria. Thiolases typically utilize a ping-pong mechanism centered on an active site cysteine residue. Reaction with the first substrate produces a covalent cysteine-thioester tethered acyl group that is transferred to the second substrate through formation of a carbon-carbon bond. Although the basics of thiolase chemistry are precedented, the mechanism by which OleA accommodates two substrates with extended carbon chains and a coenzyme moiety-unusual for a thiolase-are unknown. Gaining insights into this process could enable manipulation of the system for large scale olefin production with hydrocarbon chains lengths equivalent to those of fossil fuels. In this study, mutagenesis of the active site cysteine in Xanthomonas campestris OleA (Cys(143)) enabled trapping of two catalytically relevant species in crystals. In the resulting structures, long chain alkyl groups (C12 and C14) and phosphopantetheinate define three substrate channels in a T-shaped configuration, explaining how OleA coordinates its two substrates and product. The C143A OleA co-crystal structure possesses a single bound acyl-CoA representing the Michaelis complex with the first substrate, whereas the C143S co-crystal structure contains both acyl-CoA and fatty acid, defining how a second substrate binds to the acyl-enzyme intermediate. An active site glutamate (Gluβ(117)) is positioned to deprotonate bound acyl-CoA and initiate carbon-carbon bond formation.

  6. Substrate Trapping in Crystals of the Thiolase OleA Identifies Three Channels That Enable Long Chain Olefin Biosynthesis

    SciTech Connect

    Goblirsch, Brandon R.; Jensen, Matthew R.; Mohamed, Fatuma A.; Wackett, Lawrence P.; Wilmot, Carrie M.

    2016-11-04

    Phylogenetically diverse microbes that produce long chain, olefinic hydrocarbons have received much attention as possible sources of renewable energy biocatalysts. One enzyme that is critical for this process is OleA, a thiolase superfamily enzyme that condenses two fatty acyl-CoA substrates to produce a β-ketoacid product and initiates the biosynthesis of long chain olefins in bacteria. Thiolases typically utilize a ping-pong mechanism centered on an active site cysteine residue. Reaction with the first substrate produces a covalent cysteine-thioester tethered acyl group that is transferred to the second substrate through formation of a carbon-carbon bond. Although the basics of thiolase chemistry are precedented, the mechanism by which OleA accommodates two substrates with extended carbon chains and a coenzyme moiety—unusual for a thiolase—are unknown. Gaining insights into this process could enable manipulation of the system for large scale olefin production with hydrocarbon chains lengths equivalent to those of fossil fuels. In this study, mutagenesis of the active site cysteine in Xanthomonas campestris OleA (Cys143) enabled trapping of two catalytically relevant species in crystals. In the resulting structures, long chain alkyl groups (C12 and C14) and phosphopantetheinate define three substrate channels in a T-shaped configuration, explaining how OleA coordinates its two substrates and product. The C143A OleA co-crystal structure possesses a single bound acyl-CoA representing the Michaelis complex with the first substrate, whereas the C143S co-crystal structure contains both acyl-CoA and fatty acid, defining how a second substrate binds to the acyl-enzyme intermediate. An active site glutamate (Gluβ117) is positioned to deprotonate bound acyl-CoA and initiate carbon-carbon bond formation.

  7. Short-term disruption in regional left ventricular electrical conduction patterns increases interstitial matrix metalloproteinase activity

    PubMed Central

    Zavadzkas, Juozas A.; Rivers, William T.; McLean, Julie E.; Chang, Eileen I.; Bouges, Shenikqua; Matthews, Robert G.; Koval, Christine N.; Stroud, Robert E.; Spinale, Francis G.

    2010-01-01

    Increased matrix metalloproteinase (MMP) abundance occurs with adverse left ventricular (LV) remodeling in a number of cardiac disease states, including those induced by long-standing arrhythmias. However, whether regionally contained aberrant electrical activation of the LV, with consequent dyskinesia, alters interstitial MMP activation remained unknown. Electrical activation of the LV of pigs (n = 10, 30–35 kg) was achieved by pacing (150 beats/min) at left atrial and LV sites such that normal atrioventricular activation (60 min) was followed by regional early LV activation for 60 min within 1.5 cm of the paced site and restoration of normal atrioventricular pacing for 120 min. Regional shortening (piezoelectric crystals) and interstitial MMP activity (microdialysis with MMP fluorogenic substrate) at the LV pacing site and a remote LV site were monitored at 30-min intervals. During aberrant electrical stimulation, interstitial MMP activity at the paced site was increased (122 ± 4%) compared with the remote region (100%, P < 0.05). Restoration of atrioventricular pacing after the 60-min period of aberrant electrical activation normalized segmental shortening (8.5 ± 0.4%), but MMP activity remained elevated (121 ± 6%, P < 0.05). This study demonstrates that despite the restoration of mechanical function, disturbances in electrical conduction, in and of itself, can cause acute increases in regional in vivo MMP activation and, therefore, contribute to myocardial remodeling. PMID:20472759

  8. Short-term disruption in regional left ventricular electrical conduction patterns increases interstitial matrix metalloproteinase activity.

    PubMed

    Mukherjee, Rupak; Zavadzkas, Juozas A; Rivers, William T; McLean, Julie E; Chang, Eileen I; Bouges, Shenikqua; Matthews, Robert G; Koval, Christine N; Stroud, Robert E; Spinale, Francis G

    2010-07-01

    Increased matrix metalloproteinase (MMP) abundance occurs with adverse left ventricular (LV) remodeling in a number of cardiac disease states, including those induced by long-standing arrhythmias. However, whether regionally contained aberrant electrical activation of the LV, with consequent dyskinesia, alters interstitial MMP activation remained unknown. Electrical activation of the LV of pigs (n = 10, 30-35 kg) was achieved by pacing (150 beats/min) at left atrial and LV sites such that normal atrioventricular activation (60 min) was followed by regional early LV activation for 60 min within 1.5 cm of the paced site and restoration of normal atrioventricular pacing for 120 min. Regional shortening (piezoelectric crystals) and interstitial MMP activity (microdialysis with MMP fluorogenic substrate) at the LV pacing site and a remote LV site were monitored at 30-min intervals. During aberrant electrical stimulation, interstitial MMP activity at the paced site was increased (122 +/- 4%) compared with the remote region (100%, P < 0.05). Restoration of atrioventricular pacing after the 60-min period of aberrant electrical activation normalized segmental shortening (8.5 +/- 0.4%), but MMP activity remained elevated (121 +/- 6%, P < 0.05). This study demonstrates that despite the restoration of mechanical function, disturbances in electrical conduction, in and of itself, can cause acute increases in regional in vivo MMP activation and, therefore, contribute to myocardial remodeling.

  9. The parasite Entamoeba histolytica exploits the activities of human matrix metalloproteinases to invade colonic tissue.

    PubMed

    Thibeaux, Roman; Avé, Patrick; Bernier, Michèle; Morcelet, Marie; Frileux, Pascal; Guillén, Nancy; Labruyère, Elisabeth

    2014-10-07

    Intestinal invasion by the protozoan parasite Entamoeba histolytica is characterized by remodelling of the extracellular matrix (ECM). The parasite cysteine proteinase A5 (CP-A5) is thought to cooperate with human matrix metalloproteinases (MMPs) involved in ECM degradation. Here, we investigate the role CP-A5 plays in the regulation of MMPs upon mucosal invasion. We use human colon explants to determine whether CP-A5 activates human MMPs. Inhibition of the MMPs' proteolytic activities abolishes remodelling of the fibrillar collagen structure and prevents trophozoite invasion of the mucosa. In the presence of trophozoites, MMPs-1 and -3 are overexpressed and are associated with fibrillar collagen remodelling. In vitro, CP-A5 performs the catalytic cleavage needed to activate pro-MMP-3, which in turn activates pro-MMP-1. Ex vivo, incubation with recombinant CP-A5 was enough to rescue CP-A5-defective trophozoites. Our results suggest that MMP-3 and/or CP-A5 inhibitors may be of value in further studies aiming to treat intestinal amoebiasis.

  10. Active metal-matrix composites with embedded smart materials by ultrasonic additive manufacturing

    NASA Astrophysics Data System (ADS)

    Hahnlen, Ryan; Dapino, Marcelo J.

    2010-04-01

    This paper presents the development of active aluminum-matrix composites manufactured by Ultrasonic Additive Manufacturing (UAM), an emerging rapid prototyping process based on ultrasonic metal welding. Composites created through this process experience temperatures as low as 25 °C during fabrication, in contrast to current metal-matrix fabrication processes which require temperatures of 500 °C and above. UAM thus provides unprecedented opportunities to develop adaptive structures with seamlessly embedded smart materials and electronic components without degrading the properties that make these materials and components attractive. This research focuses on developing UAM composites with aluminum matrices and embedded shape memory NiTi, magnetostrictive Galfenol, and electroactive PVDF phases. The research on these composites will focus on: (i) electrical insulation between NiTi and Al phases for strain sensors, investigation and modeling of NiTi-Al composites as tunable stiffness materials and thermally invariant structures based on the shape memory effect; (ii) process development and composite testing for Galfenol-Al composites; and (iii) development of PVDF-Al composites for embedded sensing applications. We demonstrate a method to electrically insulate embedded materials from the UAM matrix, the ability create composites containing up to 22.3% NiTi, and their resulting dimensional stability and thermal actuation characteristics. Also demonstrated is Galfenol-Al composite magnetic actuation of up to 54 μ(see manuscript), and creation of a PVDF-Al composite sensor.

  11. Solution structure of the C-terminal domain of Ole e 9, a major allergen of olive pollen

    PubMed Central

    Treviño, Miguel Á.; Palomares, Oscar; Castrillo, Inés; Villalba, Mayte; Rodríguez, Rosalía; Rico, Manuel; Santoro, Jorge; Bruix, Marta

    2008-01-01

    Ole e 9 is an olive pollen allergen belonging to group 2 of pathogenesis-related proteins. The protein is composed of two immunological independent domains: an N-terminal domain (NtD) with 1,3-β-glucanase activity, and a C-terminal domain (CtD) that binds 1,3-β-glucans. We have determined the three-dimensional structure of CtD-Ole e 9 (101 amino acids), which consists of two parallel α-helices forming an angle of ∼55°, a small antiparallel β-sheet with two short strands, and a 3–10 helix turn, all connected by long coil segments, resembling a novel type of folding among allergens. Two regions surrounded by aromatic residues (F49, Y60, F96, Y91 and Y31, H68, Y65, F78) have been localized on the protein surface, and a role for sugar binding is suggested. The epitope mapping of CtD-Ole e 9 shows that B-cell epitopes are mainly located on loops, although some of them are contained in secondary structural elements. Interestingly, the IgG and IgE epitopes are contiguous or overlapped, rather than coincident. The three-dimensional structure of CtD-Ole e 9 might help to understand the underlying mechanism of its biochemical function and to determine possible structure–allergenicity relationships. PMID:18096638

  12. ["The Society for letters and natural science" The young Ole H. Mynster and the chemical revolution around 1800].

    PubMed

    Hansen, Sven Erik

    2015-01-01

    Ole H. Mynster (1772-1818) was a stepson of the leading physician at the Royal Frederik Hospital in Copenhagen. At an early age he became fond of zoology and mineralogy. He created "societies" in Enlightenment-style for boys and young people with lectures and collections. Later on a circle of talented young students, scientists and poets met in his small room at the hospital. Some of them with Ole Mynster as the head set up a modern scientific journal, Physicalsk, oeconomisk og medicochirurgisk Bibliotek for Danmark og Norge which encouraged the introduction of antiphlogistic chemistry. Ole Mynster became physician at the Royal Frederik Hospital and lecturer in clinical pharmacology. He wrote the first book in Danish on pharmacology based upon chemistry. In their memoirs, prominent members of his circle have told about him, and his son F.L. Mynster has written a draft for a biography. An overview of the activities within natural science and medicine of the young Ole Hieronymus Mynster is presented.

  13. Inhibition of matrix metalloproteinase activity in human dentin via novel antibacterial monomer

    PubMed Central

    Li, Fang; Majd, Hessam; Weir, Michael D.; Arola, Dwayne D.; Xu, Hockin H.K.

    2015-01-01

    Objectives Dentin-composite bond failure is caused by factors including hybrid layer degradation, which in turn can be caused by hydrolysis and enzymatic degradation of the exposed collagen in the dentin. The objectives of this study were to investigate a new antibacterial monomer (dimethylaminododecyl methacrylate, DMADDM) as an inhibitor for matrix metalloproteinases (MMPs), and to determine the effects of DMADDM on both soluble recombinant human MMPs (rhMMPs) and dentin matrix-bound endogenous MMPs. Methods Inhibitory effects of DMADDM at six mass% (0.1% to 10%) on soluble rhMMP-8 and rhMMP-9 were measured using a colorimetic assay. Matrix-bound endogenous MMP activity was evaluated in demineralized human dentin. Dentin beams were divided into four groups (n = 10) and incubated in calcium- and zinc-containing media (control medium); or control medium + 0.2% chlorhexidine (CHX); 5% 12-methacryloyloxydodecylpyridinium bromide (MDPB); or 5% DMADDM. Dissolution of dentin collagen peptides was evaluated by mechanical testing in three-point flexure, loss of dentin mass, and a hydroxyproline assay. Results Use of 0.1% to 10% DMADDM exhibited a strong concentration-dependent anti-MMP effect, reaching 90% of inhibition on rhMMP-8 and rhMMP-9 at 5% DMADDM concentration. Dentin beams in medium with 5% DMADDM showed 34% decrease in elastic modulus (vs. 73% decrease for control), 3% loss of dry dentin mass (vs. 28% loss for control), and significantly less solubilized hydroxyproline when compared with control (p < 0.05). Significance The new antibacterial monomer DMADDM was effective in inhibiting both soluble rhMMPs and matrix-bound human dentin MMPs. These results, together with previous studies showing that adhesives containing DMADDM inhibited biofilms without compromising dentin bond strength, suggest that DMADDM is promising for use in adhesives to prevent collagen degradation in hybrid layer and protect the resin-dentin bond. PMID:25595564

  14. HL7 with CORBA and OLE: software components for healthcare.

    PubMed

    Rishel, W

    1996-01-01

    Componentized software promises easier, more fine-grained integration of disparate software systems. Variations of the technology can help to achieve tight coupling among disparate programs on the clinical workstation or across wide area networks. HL7 members have been designing extensions to the protocol for the exchange of healthcare information using Microsoft OLE and CORBA technologies. Extensive prototyping has been performed, including the simultaneous interconnection of sixteen different vendor systems exchanging demographic data and lab results. The first release of this standard will be notable in that the specifications for OLE and CORBA will be entirely isomorphic, they will be based directly, on HL7 version 2.3, and they may easily be implemented in systems that are not written using object-oriented programming tools. As HL7 version 3 is developed on an object-oriented model of healthcare information, the same approach will be used so information about the objects may be shared using CORBA and OLE.

  15. Evaluation of OLED and edge-lit LED lighting panels

    NASA Astrophysics Data System (ADS)

    Mou, Xi; Narendran, Nadarajah; Zhu, Yiting; Freyssinier, Jean Paul

    2016-09-01

    Solid-state lighting (SSL) offers a new technology platform for lighting designers and end-users to illuminate spaces with low energy demand. Two types of SSL sources include organic light-emitting diodes (OLEDs) and light-emitting diodes (LEDs). OLED is an area light source, and its primary competing technology is the edge-lit LED panel. Generally, both of these technologies are considered similar in shape and appearance, but there is little understanding of how people perceive discomfort glare from large area light sources. The objective of this study was to evaluate discomfort glare for the two lighting technologies under similar operating conditions by gathering observers' reactions. The human factors study results showed no statistically significant difference in human response to discomfort glare between OLED and edge-lit LED panels when the two light sources produced the same lighting stimulus. This means both technologies appeared equally glary beyond a certain luminance.

  16. High efficiency deep-blue and white phosphorescent OLEDs

    NASA Astrophysics Data System (ADS)

    Xue, Jiangeng; Eom, Sang-Hyun; Zheng, Ying; Wrzesniewski, Edward; Chopra, Neetu; Lee, Jaewon; So, Franky

    2009-08-01

    We report studies on blue and white organic light-emitting devices (OLEDs) based on the deep-blue electrophosphorescent dye iridium(III) bis(4',6'-difluorophenylpyridinato)tetrakis(1-pyrazolyl)borate (FIr6). Using high triplet energy charge transport layers and a dual-emissive-layer structure as well as the p-i-n device structure, we have achieved external quantum efficiencies of 20% and maximum power efficiency of 36 lm/W in these deep-blue OLEDs. White OLEDs with a CRI of 79 and a maximum power efficiency of 40 lm/W were also demonstrated by incorporating red and green phosphorescent dopants together with FIr6.

  17. Materials and architectures for efficient harvesting of singlet and triplet excitons for white light emitting OLEDs

    SciTech Connect

    Thompson, Mark E; Forrest, Stephen

    2015-02-03

    The present invention relates to organic light emitting devices (OLEDs), and more specifically to OLEDS that emit light using a combination of fluorescent emitters and phosphorescent emitters for the efficient utilization of all of the electrically generated excitons.

  18. PIASxbeta is a key regulator of osterix transcriptional activity and matrix mineralization in osteoblasts.

    PubMed

    Ali, Md Moksed; Yoshizawa, Tatsuya; Ishibashi, Osamu; Matsuda, Akio; Ikegame, Mika; Shimomura, Junko; Mera, Hisashi; Nakashima, Kazuhisa; Kawashima, Hiroyuki

    2007-08-01

    We recently reported that tensile stress induces osteoblast differentiation and osteogenesis in the mouse calvarial suture in vitro. Using this experimental system, we identified PIASxbeta, a splice isoform of Pias2, as one of the genes most highly upregulated by tensile stress. Further study using cell culture revealed that this upregulation was transient and was accompanied by upregulation of other differentiation markers, including osterix, whereas expression of Runx2 was unaffected. Runx2 and osterix are the two master proteins controlling osteoblast differentiation, with Runx2 being upstream of osterix. Targeted knockdown of PIASxbeta by small interfering RNA (siRNA) markedly suppressed osteoblastic differentiation and matrix mineralization, whereas transient overexpression of PIASxbeta caused the exact opposite effects. Regardless of PIASxbeta expression level, Runx2 expression remained constant. Reporter assays demonstrated that osterix enhanced its own promoter activity, which was further stimulated by PIASxbeta but not by its sumoylation-defective mutant. NFATc1 and NFATc3 additionally increased osterix transcriptional activity when co-transfected with PIASxbeta. Because osterix has no consensus motif for sumoylation, other proteins are probably involved in the PIASxbeta-mediated activation and NFAT proteins may be among such targets. This study provides the first line of evidence that PIASxbeta is indispensable for osteoblast differentiation and matrix mineralization, and that this signaling molecule is located between Runx2 and osterix.

  19. The dynamic interaction between matrix metalloproteinase activity and adverse myocardial remodeling.

    PubMed

    Janicki, Joseph S; Brower, Gregory L; Gardner, Jason D; Chancey, Amanda L; Stewart, James A

    2004-01-01

    The process of cardiac remodeling in response to cardiac injury and/or persistent elevations in wall stress generally relates to the progressive changes that occur in ventricular chamber dimensions and the various components of the myocardium, in particular the cardiomyocytes and the extracellular matrix. Volume overload, pressure overload or myocardial injury produces a sustained abnormal elevation in myocardial wall stress which initiates cardiac remodeling that frequently results in ventricular decompensation and heart failure. Regardless of the inciting cause, there appear to be three distinct phases to this process. In the initial phase, fibrillar collagen is partially degraded secondary to increased matrix metalloproteinase (MMP) activity. Following this, there is a chronic compensatory phase during which MMP activity and collagen concentration return to normal while cardiomyocyte size continues to progressively increase. The final phase is attained once the compensatory hypertrophic mechanisms are exhausted and is characterized by elevated MMP activity, marked ventricular dilatation and prominent fibrosis. Details of this progressive, dynamic remodeling process and its effect on ventricular function during chronic volume overload, chronic pressure overload and following myocardial infarction will be the focus of this article.

  20. Proteolytic degradation of intestinal mucosal extracellular matrix after lamina propria T cell activation.

    PubMed Central

    Pender, S L; Lionetti, P; Murch, S H; Wathan, N; MacDonald, T T

    1996-01-01

    BACKGROUND: Proteoglycans, consisting of glycosaminoglycan (GAG) side chains covalently linked to a protein core, are a major component of the extracellular matrix of the intestinal lamina propria. AIMS: This study investigated the effects of lamina propria T cell activation on the proteoglycan component of the matrix. METHODS: The high degree of sulphation of GAGs means that they are polyanionic and thus can be visualised in tissue sections by means of colloidal-gold labelled cationic probes. RESULTS: In human fetal small intestine there is a dense meshwork of anionic residues in the lamina propria and basement membrane. When explants of human fetal small intestine are cultured ex vivo, and resident lamina propria T cells are activated with pokeweed mitogen, mucosal destruction occurs within three days. This is associated with the rapid loss of anionic sites from the lamina propria. Dermatan sulphate proteoglycan is lost from the tissue and is present at increased concentrations in the organ culture supernatants, indicating that T cell activation has led to solubilisation of lamina propria proteoglycans. Tissue destruction and loss of anionic residues are inhibited in a dose dependent fashion by dexamethasone, and by the protease inhibitor, alpha 2 macroglobulin. CONCLUSIONS: Proteolytic degradation of the lamina propria may therefore be a mechanism by which T cell hypersensitivity injures the intestinal mucosa. Images Figure 1 Figure 4 Figure 5 PMID:8977345

  1. Activity of matrix metalloproteinase-2 (MMP-2) in canine oronasal tumors.

    PubMed

    Nakaichi, Munekazu; Yunuki, Toshi; Okuda, Masaru; Une, Satoshi; Taura, Yasuho

    2007-04-01

    Activity of matrix metalloprotease-2 (MMP-2) and the expression of its related molecules were examined in spontaneous canine oronasal tumors. Tissue samples from melanoma and squamous cell carcinoma possessed higher MMP-2 activity, as shown in gelatin zymography, in comparison with acanthomatous epulis and nasal adenocarcinoma. Regional lymph node invasion and distant metastases were more frequently observed in the MMP-2 positive cases. There were no significant differences by RT-PCR examination in the expression of the genes encoding MMP-2, MT1-MMP and TIMP-2 among the tumor histological types. However, the MMP-2/TIMP-2 ratio showed a significantly higher level of the genes in the malignant oral melanoma and squamous cell carcinoma. The MMP-2/TIMP-2 ratio was also positively correlated with MMP-2 activity in gelatin zymography. These results indicate that the MMP-2/TIMP-2 ratio may be of value in evaluating the prognosis in canine oronasal cavity tumors.

  2. Stimulation of Periodontal Ligament Stem Cells by Dentin Matrix Protein 1 Activates Mitogen-Activated Protein Kinase and Osteoblast Differentiation

    PubMed Central

    Chandrasekaran, Sangeetha; Ramachandran, Amsaveni; Eapen, Asha; George, Anne

    2013-01-01

    Background Periodontitis can ultimately result in tooth loss. Many natural and synthetic materials have been tried to achieve periodontal regeneration, but the results remain variable and unpredictable. We hypothesized that exogenous treatment with dentin matrix protein 1 (DMP1) activates specific genes and results in phenotypic and functional changes in human periodontal ligament stem cells (hPDLSCs). Methods hPDLSCs were isolated from extracted teeth and cultured in the presence or absence of DMP1. Quantitative polymerase chain reactions were performed to analyze the expression of several genes involved in periodontal regeneration. hPDLSCs were also processed for immunocytochemical and Western blot analysis using phosphorylated extracellular signal-regulated kinase (pERK) and ERK antibodies. Alkaline phosphatase and von Kossa staining were performed to characterize the differentiation of hPDLSCs into osteoblasts. Field emission scanning electron microscopic analysis of the treated and control cell cultures were also performed. Results Treatment with DMP1 resulted in the upregulation of genes, such as matrix metalloproteinase-2, alkaline phosphatase, and transforming growth factor β1. Activation of ERK mitogen-activated protein kinase signaling pathway and translocation of pERK from the cytoplasm to the nucleus was observed. Overall, DMP1-treated cells showed increased expression of alkaline phosphatase, increased matrix, and mineralized nodule formation when compared with untreated controls. Conclusion DMP1 can orchestrate a coordinated expression of genes and phenotypic changes in hPDLSCs by activation of the ERK signaling pathway, which may provide a valuable strategy for tissue engineering approaches in periodontal regeneration. PMID:22612367

  3. Increased Serum Activity of Matrix Metalloproteinase-9 in Patients with Acute Variceal Bleeding

    PubMed Central

    Kwon, Oh Sang; Jung, Hyuk Sang; Bae, Kyung Sook; Jung, Young Kul; Kim, Yeon Suk; Choi, Duck Joo; Kim, Yun Soo

    2012-01-01

    Background/Aims Matrix metalloproteinases (MMP)-2 and -9 can degrade essential components of vascular integrity. The aim of this study was to investigate the association between those MMPs and variceal bleeding (VB). Methods Fifteen controls, 12 patients with acute ulcer bleeding (UB) group, 37 patients with varix (V group), and 35 patients with acute VB group were enrolled. Serum was obtained to measure MMP-2 and -9 activity by zymogram protease assays. Results The activity levels of these compounds were compared with the controls' median value. The median MMP-9 activity was 1.0 in controls, 1.05 in the UB group, 0.43 in the V group, and 0.96 in the VB group. The level of MMP-9 activity was higher in the VB group than in the V group (p<0.001). In the VB group, there was a signifi cant decrease in MMP-9 activity over time after bleeding (p<0.001). The median MMP-2 activity level was 1.0 in controls, 1.01 in the UB group, 1.50 in the V group, and 1.55 in the VB group. The level of MMP-2 activity was similar in the VB and V groups. Conclusions The level of MMP-9 activity increased in association with VB. The role of MMP-9 in the pathogenesis of VB should be verified. PMID:22570756

  4. 1alpha,25(OH)2D3 is an autocrine regulator of extracellular matrix turnover and growth factor release via ERp60 activated matrix vesicle metalloproteinases.

    PubMed

    Boyan, Barbara D; Wong, Kevin L; Fang, Mimi; Schwartz, Zvi

    2007-03-01

    Growth plate chondrocytes produce proteoglycan-rich type II collagen extracellular matrix (ECM). During cell maturation and hypertrophy, ECM is reorganized via a process regulated by 1alpha,25(OH)(2)D(3) and involving matrix metalloproteinases (MMPs), including MMP-3 and MMP-2. 1alpha,25(OH)(2)D(3) regulates MMP incorporation into matrix vesicles (MVs), where they are stored until released. Like plasma membranes (PM), MVs contain the 1alpha,25(OH)(2)D(3)-binding protein ERp60, phospholipase A(2) (PLA(2)), and caveolin-1, but appear to lack nuclear Vitamin D receptors (VDRs). Chondrocytes produce 1alpha,25(OH)(2)D(3) (10(-8)M), which binds ERp60, activating PLA(2), and resulting lysophospholipids lead to MV membrane disorganization, releasing active MMPs. MV MMP-3 activates TGF-beta1 stored in the ECM as large latent TGF-beta1 complexes, consisting of latent TGF-beta1 binding protein, latency associated peptide, and latent TGF-beta1. Others have shown that MMP-2 specifically activates TGF-beta2. TGF-beta1 regulates 1alpha,25(OH)(2)D(3)-production, providing a mechanism for local control of growth factor activation. 1alpha,25(OH)(2)D(3) activates PKCalpha in the PM via ERp60-signaling through PLA(2), lysophospholipid production, and PLCbeta. It also regulates distribution of phospholipids and PKC isoforms between MVs and PMs, enriching the MVs in PKCzeta. Direct activation of MMP-3 in MVs requires ERp60. However, when MVs are treated with 1alpha,25(OH)(2)D(3), PKCzeta activity is decreased and PKCalpha is unaffected, suggesting a more complex feedback mechanism, potentially involving MV lipid signaling.

  5. Tissue inhibitors of matrix metalloproteinases 1 and 2 and matrix metalloproteinase activity in the serum and lungs of mice with lewis lung carcinoma.

    PubMed

    Kisarova, Ya A; Korolenko, T A

    2012-10-01

    We studied the content of tissue inhibitors of matrix metalloproteinases 1 and 2 (TIMP-1 and TIMP-2) and activities of matrix metalloproteinases (MMP) in the serum and lungs of mice with Lewis lung carcinoma metastasizing into the lung. Metastasizing was associated with increased serum content of TIMP-1 and TIMP-2 (only on day 20 at the terminal stage of the tumor process). These data confirm the hypothesis on pro-tumorigenic role of TIMP-1 in the serum. Locally, the development of metastases was associated with a decrease in TIPM-1 concentration (day 7), an increase in TIMP-2 concentration (days 7 and 20), and elevated activity of MMP at all terms of the study (days 7, 15, and 20). Increased concentration of TIMP-2 in the lungs (but not in the serum) can be regarded as an indicator of Lewis lung carcinoma metastasizing.

  6. Dielectric nanoparticles for the enhancement of OLED light extraction efficiency

    NASA Astrophysics Data System (ADS)

    Mann, Vidhi; Rastogi, Vipul

    2017-03-01

    This work reports the use of dielectric nanoparticles placed at glass substrate in the improvement of light extraction efficiency of organic light emitting diode (OLED). The nanoparticles will act as scattering medium for the light trapped in the waveguiding modes of the device. The scattering efficiency of dielectric nanoparticles has been calculated by Mie Theory. The finite difference time domain (FDTD) analysis and simulation estimate the effect of dielectric nanoparticles on the light extraction efficiency of OLED. The efficiency depends upon the diameter, interparticle separation and refractive index of dielectric nanoparticles. It is shown that the dielectric nanoparticles layer can enhance the light extraction efficiency by a factor of 1.7.

  7. Collagen-binding VEGF mimetic peptide: Structure, matrix interaction, and endothelial cell activation

    NASA Astrophysics Data System (ADS)

    Chan, Tania R.

    Long term survival of artificial tissue constructs depends greatly on proper vascularization. In nature, differentiation of endothelial cells and formation of vasculature are directed by dynamic spatio-temporal cues in the extracellular matrix that are difficult to reproduce in vitro. In this dissertation, we present a novel bifunctional peptide that mimics matrix-bound vascular endothelial growth factor (VEGF), which can be used to encode spatially controlled angiogenic signals in collagen-based scaffolds. The peptide, QKCMP, contains a collagen mimetic domain (CMP) that binds to type I collagen by a unique triple helix hybridization mechanism and a VEGF mimetic domain (QK) with pro-angiogenic activity. We demonstrate QKCMP's ability to hybridize with native and heat denatured collagens through a series of binding studies on collagen and gelatin substrates. Circular dichroism experiments show that the peptide retains the triple helical structure vital for collagen binding, and surface plasmon resonance study confirms the molecular interaction between the peptide and collagen strands. Cell culture studies demonstrate QKCMP's ability to induce endothelial cell morphogenesis and network formation as a matrix-bound factor in 2D and 3D collagen scaffolds. We also show that the peptide can be used to spatially modify collagen-based substrates to promote localized endothelial cell activation and network formation. To probe the biological events that govern these angiogenic cellular responses, we investigated the cell signaling pathways activated by collagen-bound QKCMP and determined short and long-term endothelial cell response profiles for p38, ERK1/2, and Akt signal transduction cascades. Finally, we present our efforts to translate the peptide's in vitro bioactivity to an in vivo burn injury animal model. When implanted at the wound site, QKCMP functionalized biodegradable hydrogels induce enhanced neovascularization in the granulation tissue. The results show QKCMP

  8. Chromium liquid waste inertization in an inorganic alkali activated matrix: leaching and NMR multinuclear approach.

    PubMed

    Ponzoni, Chiara; Lancellotti, Isabella; Barbieri, Luisa; Spinella, Alberto; Saladino, Maria Luisa; Martino, Delia Chillura; Caponetti, Eugenio; Armetta, Francesco; Leonelli, Cristina

    2015-04-09

    A class of inorganic binders, also known as geopolymers, can be obtained by alkali activation of aluminosilicate powders at room temperature. The process is affected by many parameters (curing time, curing temperature, relative humidity etc.) and leads to a resistant matrix usable for inertization of hazardous waste. In this study an industrial liquid waste containing a high amount of chromium (≈ 2.3 wt%) in the form of metalorganic salts is inertized into a metakaolin based geopolymer matrix. One of the innovative aspects is the exploitation of the water contained in the waste for the geopolymerization process. This avoided any drying treatment, a common step in the management of liquid hazardous waste. The evolution of the process--from the precursor dissolution to the final geopolymer matrix hardening--of different geopolymers containing a waste amount ranging from 3 to 20%wt and their capability to inertize chromium cations were studied by: i) the leaching tests, according to the EN 12,457 regulation, at different curing times (15, 28, 90 and 540 days) monitoring releases of chromium ions (Cr(III) and Cr(VI)) and the cations constituting the aluminosilicate matrix (Na, Si, Al); ii) the humidity variation for different curing times (15 and 540 days); iii) SEM characterization at different curing times (28 and 540 days); iv) the trend of the solution conductivity and pH during the leaching test; v) the characterization of the short-range ordering in terms of TOT bonds (where T is Al or Si) by (29)Si and (27)Al solid state magic-angle spinning nuclear magnetic resonance (ss MAS NMR) for geopolymers containing high amounts of waste (10-20%wt). The results show the formation of a stable matrix after only 15 days independently on the waste amount introduced; the longer curing times increase the matrices stabilities and their ability to immobilize chromium cations. The maximum amount of waste that can be inertized is around 10 wt% after a curing time of 28 days.

  9. Aryl hydrocarbon receptor activation impairs extracellular matrix remodeling during zebra fish fin regeneration.

    PubMed

    Andreasen, Eric A; Mathew, Lijoy K; Löhr, Christiane V; Hasson, Rachelle; Tanguay, Robert L

    2007-01-01

    Adult zebra fish completely regenerate their caudal (tail) fin following partial amputation. Exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) inhibits this regenerative process. Proper regulation of transcription, innervation, vascularization, and extracellular matrix (ECM) composition is essential for complete fin regeneration. Previous microarray studies suggest that genes involved in ECM regulation are misexpressed following activation of the aryl hydrocarbon receptor. To investigate whether TCDD blocks regeneration by impairing ECM remodeling, male zebra fish were i.p. injected with 50 ng/g TCDD or vehicle, and caudal fins were amputated. By 3 days postamputation (dpa), the vascular network in the regenerating fin of TCDD-exposed fish was disorganized compared to vehicle-exposed animals. Furthermore, immunohistochemical staining revealed that axonal outgrowth was impacted by TCDD as early as 3 dpa. Histological analysis demonstrated that TCDD exposure leads to an accumulation of collagen at the end of the fin ray just distal to the amputation site by 3 dpa. Mature lepidotrichial-forming cells (fin ray-forming cells) were not observed in the fins of TCDD-treated fish. The capacity to metabolize ECM was also altered by TCDD exposure. Quantitative real-time PCR studies revealed that the aryl hydrocarbon pathway is active and that matrix-remodeling genes are expressed in the regenerate following TCDD exposure.

  10. High Efficancy Integrated Under-Cabinet Phosphorescent OLED

    SciTech Connect

    Michael Hack

    2001-10-31

    In this two year program Universal Display Corporation (UDC) together with the University of Michigan, Teknokon, developed and delivered an energy efficient phosphorescent OLED under cabinet illumination system. Specifically the UDC team goal was in 2011 to deliver five (5) Beta level OLED under cabinet lighting fixtures each consisting of five 6-inch x 6-inch OLED lighting panels, delivering over 420 lumens, at an overall system efficacy of >60 lm/W, a CRI of >85, and a projected lifetime to 70% of initial luminance to exceed 20,000 hours. During the course of this program, the Team pursued the commercialization of these OLED based under cabinet lighting fixtures, to enable the launch of commercial OLED lighting products. The UDC team was ideally suited to develop these novel and efficient solid state lighting fixtures, having both the technical experience and commercial distribution mechanisms to leverage work performed under this contract. UDC's business strategy is to non-exclusively license its PHOLED technology to lighting manufacturers, and also supply them with our proprietary PHOLED materials. UDC is currently working with several licensees who are manufacturing OLED lighting panels using our technology. During this 2 year program, we further developed our high efficiency white Phosphorescent OLEDs from the first milestone, achieving a 80 lm/W single pixel to the final milestone, achieving an under-cabinet PHOLED lighting system that operates at 56 lm/W at 420 lumens. Each luminaire was comprised of ten 15cm x 7.5cm lighting modules mounted in outcoupling enhancement lenses and a control module. The lamps modules are connected together using either plugs or wires with plugs on each end, allowing for unlimited configurations. The lamps are driven by an OLED driver mounted in an enclosure which includes the AC plug. As a result of advancements gained under this program, the path to move OLED lighting panels from development into manufacturing has been

  11. Advances in OLED-based oxygen sensors with structurally integrated OLED, sensor film, and thin-film Si photodetector

    NASA Astrophysics Data System (ADS)

    Ghosh, Debju; Shinar, Ruth; Cai, Yuankun; Zhou, Zhaoqun; Dalal, Vikram L.; Shinar, Joseph

    2007-09-01

    Steps towards the improvement of a compact photoluminescence (PL)-based sensor array that is fully structurally integrated are described. The approach is demonstrated for oxygen sensing, which can be monitored via its effect on the PL intensity I or decay time τ of oxygen-sensitive dyes such as Pt octaethylporphryn (PtOEP) and its Pd analog (PdOEP). The integrated components include (1) an organic light emitting device (OLED) excitation source, which is an array of coumarin-doped tris(quinolinolate) Al (Alq 3) pixels, (2) the sensor film, i.e., PdOEP embedded in polystyrene, and (3) the photodetector (PD), which is a plasma-enhanced CVD-grown p-i-n or n-i-p structure, based on amorphous or nanocrystalline (Si,Ge):H. These components are fabricated on common or separate substrates that are attached back-to-back, resulting in sensors with a thickness largely determined by that of the substrates. The fully integrated oxygen sensor is demonstrated first by fabricating each of the three components on a separate substrate. The PD was placed in front of a flow cell containing the sensor film, while the OLED array was "behind" the sensor film. This design showed the expected trend in monitoring different concentration of O II via their effect on I, with improved detection sensitivity achieved by shielding the electromagnetic noise synchronous with the pulsed OLED. The detection sensitivity using the I monitoring mode is expected to further increase by reducing the OLED tail emission. The issue of the OLED background can be eliminated by monitoring the oxygen concentration via its effect on τ, where the OLED is pulsed and τ is measured while the OLED is off. Steps therefore focused also on shortening the response time of the PDs, and understanding the factors affecting their speed. Development of a sensor array, where the PD pixels are fabricated between the OLED pixels on the same side of a common substrate, is also discussed.

  12. Low level laser therapy modulates viability, alkaline phosphatase and matrix metalloproteinase-2 activities of osteoblasts.

    PubMed

    Oliveira, Flávia Amadeu de; Matos, Adriana Arruda; Matsuda, Sandra Satiko; Buzalaf, Marília Afonso Rabelo; Bagnato, Vanderley Salvador; Machado, Maria Aparecida de Andrade Moreira; Damante, Carla Andreotti; Oliveira, Rodrigo Cardoso de; Peres-Buzalaf, Camila

    2017-04-01

    Low level laser therapy (LLLT) has been shown to stimulate bone cell metabolism but their impact on the matrix metalloproteinase (MMP) expression and activity is little explored. This study evaluated the influence of LLLT at two different wavelengths, red and infrared, on MC3T3-E1 preosteoblast viability, alkaline phosphatase (ALP) and MMP-2 and -9 activities. To accomplish this, MC3T3-E1 cells were irradiated with a punctual application of either red (660nm; InGaAIP active medium) or infrared (780nm; GaAlAs active medium) lasers both at a potency of 20mW, energy dose of 0.08 or 0.16J, and energy density of 1.9J/cm(2) or 3.8J/cm(2), respectively. The control group received no irradiation. Cellular viability, ALP and MMP-2 and -9 activities were assessed by MTT assay, enzymatic activity and zymography, respectively, at 24, 48 and 72h. The treatment of cells with both red and infrared lasers significantly increased the cellular viability compared to the non-irradiated control group at 24 and 48h. The ALP activity was also up modulated in infrared groups at 24 and 72h, depending on the energy densities. In addition, the irradiation with red laser at the energy density of 1.9J/cm(2) promoted an enhancement of MMP-2 activity at 48 and 72h. However, no differences were observed for the MMP-9 activity. In conclusion, when used at these specific parameters, LLL modulates both preosteoblast viability and differentiation highlighted by the increased ALP and MMP-2 activities induced by irradiation.

  13. Prospects for treating osteoarthritis: enzyme–protein interactions regulating matrix metalloproteinase activity

    PubMed Central

    Meszaros, Evan

    2012-01-01

    Primary osteoarthritis (OA) is a musculoskeletal disorder of unknown etiology. OA is characterized by an imbalance between anabolism and catabolism in, and altered homeostasis of articular cartilage. Matrix metalloproteinases (MMPs) and a disintegrin and metalloproteinase with thrombospondin motif are upregulated in OA joints. Extracellular matrix (ECM) proteins are critical for resistance to compressive forces and for maintaining the tensile properties of the tissue. Tissue inhibitor of metalloproteinases (TIMPs) is the endogenous inhibitor of MMPs, but in OA, TIMPs do not effectively neutralize MMP activity. Upregulation of MMP gene expression occurs in OA in a milieu of proinflammatory cytokines such as interleukin (IL)-1, IL-6 and tumor necrosis factor α. Presently, the medical therapy of OA includes mainly nonsteroidal anti-inflammatory drugs and corticosteroids which dampen pain and inflammation but appear to have little effect on restoring joint function. Experimental interventions to restore the imbalance between anabolism and catabolism include small molecule inhibitors of MMP subtypes or inhibitors of the interaction between IL-1 and its receptor. Although these agents have some positive effects on reducing MMP subtype activity they have little efficacy at the clinical level. MMP-9 is one MMP subtype implicated in the degradation of articular cartilage ECM proteins. MMP-9 was found in OA synovial fluid as a complex with neutrophil gelatinase-associated lipocalin (NGAL) which protected MMP-9 from autodegradation. Suppressing NGAL synthesis or promoting NGAL degradation may result in reducing the activity of MMP-9. We also propose initiating a search for enzyme–protein interactions to dampen other MMP subtype activity which could suppress ECM protein breakdown. PMID:23342237

  14. Enhanced performance of organic light-emitting diodes (OLEDs) and OLED-based photoluminescent sensing platforms by novel microstructures and device architectures

    SciTech Connect

    Liu, Rui

    2012-01-01

    After a general introduction to OLEDs and OLED-based PL sensors, the transient emission mechanism of guest-host OLEDs is described both experimentally and theoretically. A monolithic and easy-to-apply process is demonstrated for fabricating multicolor microcavity OLEDs (that improve the sensor platform). The outcoupling issues of OLEDs at the substrate/air interface are addressed by using a microstructured polymer film resulting from a PS and polyethylene glycol (PEG) mixture. Based on the understanding of OLEDs and their improvement, research was done in order to realize integrated all organic-based O2 and pH sensors with improved signal intensity and sensitivity. The sensor design modification and optimization are summarized

  15. Ole Ivar Lovaas--His Life, Merits and Legacy

    ERIC Educational Resources Information Center

    Özerk, Kamil; Vea, Gunvor Dalby; Eikeseth, Svein; Özerk, Meral

    2016-01-01

    Ole Ivar Lovaas (1927-2010) is known worldwide for his research within the field of Applied Behavior Analysis, and is probably the most influential researcher within the field of treatment of children with autism. In the first part of this biographically oriented paper, we inform the readers about his family background, childhood, elementary and…

  16. Differential expression and activity of matrix metalloproteinases 2 and 9 in canine early placenta.

    PubMed

    Diessler, M; Ventureira, M; Hernandez, R; Sobarzo, C; Casas, L; Barbeito, C; Cebral, E

    2017-02-01

    The zonary and endotheliochorial dog placenta is the most invasive placenta of carnivores. The importance of matrix metalloproteinases (MMP) in placenta invasiveness has been determined in several mammals including species with haemochorial, epitheliochorial and endotheliochorial placentation. Regarding the latter, the expression of MMP enzymes has been studied in the cat and the mature canine placenta. The aim of this study was to analyse the expression and activity of MMP-2 and MMP-9 in the early dog placenta. Placentae from 18 to 30 days of pregnancy were collected from four bitches. Two placentae from each bitch were analysed. Placental tissue from one uterine horn was fixed in formaldehyde for immunohistochemistry, while marginal haematoma, labyrinth, non-implantative and implantative endometrium from the contralateral horn were immediately frozen in dry ice for the analysis of MMP expression (Western blot [WB]) and activity (zymography). MMP-2 and MMP-9 were evidenced in the labyrinth, maternal glands and marginal haematoma; this finding was directly correlated with levels of MMP expression by WB, and with the activity of MMP-2, mainly in the haematoma (the area of major remodelling of tissues). Thus, although MMP-9 is well expressed in the early canine placenta, it is not active. Given the important role of MMPs for invasiveness, maternal-foetal angiogenesis and the establishment of a correct foetal nutrition, the results are consistent with the findings in other species in which the MMP-2 activation precedes the MMP-9 one in early placentation.

  17. 8-Iso-prostaglandin f(2alpha) reduces trophoblast invasion and matrix metalloproteinase activity.

    PubMed

    Staff, A C; Ranheim, T; Henriksen, T; Halvorsen, B

    2000-06-01

    Preeclampsia is a common pregnancy complication in the latter half of gestation diagnosed by hypertension and proteinuria. A key feature of preeclampsia is an altered placentation with reduced trophoblast invasion. Normal placentation requires controlled invasion of trophoblasts into the maternal uterine wall, with secretion of specific proteolytic enzymes able to degrade basement membranes and extracellular matrix, such as the matrix metalloproteinases (MMPs). 8-Iso-prostaglandin F(2alpha) (8-iso-PGF(2alpha)) is a marker of oxidative stress in vivo and is biologically active. We have recently reported an elevated content of free 8-iso-PGF(2alpha) in preeclamptic gestational tissue at delivery. Assuming an elevated level of 8-iso-PGF(2alpha) during the invasion period of the pregnancy, we hypothesized that 8-iso-PGF(2alpha) could reduce invasion of JAR cells, a choriocarcinoma cell line. We investigated JAR cell invasion with 2 types of Transwell assays and demonstrated that 8-iso-PGF(2alpha) (10 micromol/L) resulted in reduced cell invasion in both the colorimetric and radioactivity Transwell assays (P<0.01). Zymograms revealed reduced MMP-2 and MMP-9 activity in conditioned media from JAR cells incubated with 8-iso-PGF(2alpha) (10 micromol/L) (P<0.02). 8-Iso-PGF(2alpha) (10 micromol/L) also reduced the collagenase type IV activity in the conditioned media of JAR cells (P=0.04). No effects on MMP-2 and MMP-9 mRNA levels were observed after incubation with 8-iso-PGF(2alpha) (10 micromol/L), whereas protein levels were significantly decreased (P<0.02), suggesting a posttranscriptional regulation. We hypothesize a potential role for 8-iso-PGF(2alpha) in the reduced trophoblast invasion in preeclampsia.

  18. Detecting seismic activity with a covariance matrix analysis of data recorded on seismic arrays

    NASA Astrophysics Data System (ADS)

    Seydoux, L.; Shapiro, N. M.; de Rosny, J.; Brenguier, F.; Landès, M.

    2016-03-01

    Modern seismic networks are recording the ground motion continuously at the Earth's surface, providing dense spatial samples of the seismic wavefield. The aim of our study is to analyse these records with statistical array-based approaches to identify coherent time-series as a function of time and frequency. Using ideas mainly brought from the random matrix theory, we analyse the spatial coherence of the seismic wavefield from the width of the covariance matrix eigenvalue distribution. We propose a robust detection method that could be used for the analysis of weak and emergent signals embedded in background noise, such as the volcanic or tectonic tremors and local microseismicity, without any prior knowledge about the studied wavefields. We apply our algorithm to the records of the seismic monitoring network of the Piton de la Fournaise volcano located at La Réunion Island and composed of 21 receivers with an aperture of ˜15 km. This array recorded many teleseismic earthquakes as well as seismovolcanic events during the year 2010. We show that the analysis of the wavefield at frequencies smaller than ˜0.1 Hz results in detection of the majority of teleseismic events from the Global Centroid Moment Tensor database. The seismic activity related to the Piton de la Fournaise volcano is well detected at frequencies above 1 Hz.

  19. Performance and modeling of active metal-matrix composites manufactured by ultrasonic additive manufacturing

    NASA Astrophysics Data System (ADS)

    Hahnlen, Ryan; Dapino, Marcelo J.

    2011-04-01

    This paper presents the development and characterization of active aluminum-matrix composites manufactured by Ultrasonic Additive Manufacturing (UAM), an emerging rapid prototyping process based on ultrasonic metal welding. The primary benefit of UAM over other metal-matrix fabrication processes is the low process temperatures, as low as 25 °C. UAM thus provides unprecedented opportunities to develop adaptive structures with seamlessly embedded smart materials and electronic components without degrading the properties that make these materials and components attractive. The objective of this research is to develop UAM composites with aluminum matrices and embedded shape memory NiTi, magnetostrictive Galfenol (FeGa), and polyvinylidene fluoride (PVDF) phases. The paper is focused on the thermally induced strain response and stiffness behavior of NiTi-Al composites, the actuation properties of FeGa-Al composites, and the embedded sensing capabilities of PVDF-Al composites. We observe up to a 10% increase over room temperature stiffness for NiTi-Al composites and a magnetomechanical response in the FeGa-Al composite up to 52.4 μɛ. The response of the PVDF-Al composite to harmonic loads is observed over a frequency range of 10 to 1000 Hz.

  20. 92-kd type IV collagenase (matrix metalloproteinase-9) activity in human amniochorion increases with labor.

    PubMed Central

    Vadillo-Ortega, F.; González-Avila, G.; Furth, E. E.; Lei, H.; Muschel, R. J.; Stetler-Stevenson, W. G.; Strauss, J. F.

    1995-01-01

    To determine whether specific collagenolytic enzymes are expressed in human fetal membranes with labor, we examined gelatinase activity in extracts of amniochorion by zymography. The 92-kd gelatinase (MMP-9) was barely detectable in extracts of fetal membranes before the onset of labor but was readily demonstrable in extracts prepared from membranes isolated from laboring women or membranes collected immediately after delivery. In contrast, the 72-kd gelatinase (MMP-2) was detectable in extracts from pre- and post-labor membranes. Ethylenediaminetetracetic acid and the tissue inhibitor of metalloproteinases, TIMP-1, inhibited the gelatinase activities detected by zymography, confirming that the enzymes are metalloproteinase. Assay of amniochorion gelatinase activity using a radiolabeled denatured collagen substrate revealed a more than twofold increase in activity comparing pre-labor with post-labor fetal membrane extracts. A function-blocking anti-MMP-9 monoclonal antibody inhibited pre-labor membrane gelatinase activity by approximately 11.5%, which was only slightly greater inhibition than observed with irrelevant monoclonal antibodies. However, post-labor membrane gelatinase activity was reduced by 53% by the function-blocking antibody, indicating that MMP-9 is a major contributor to the increased gelatinase activity extractable from post-labor membranes. Western blot analyses demonstrated increased MMP-9 protein in amniochorion extracts after onset of labor. MMP-9 protein and mRNA were co-localized in amnion epithelium, underlying macrophages and chorion laeve trophoblast and decidual cells after labor. We conclude that 1) MMP-9 activity and protein in human amniochorion increases with labor and 2) MMP-9 is expressed by amnion epithelium, macrophages and chorion laeve trophoblast and decidual cells. The increased expression of MMP-9 may result in degradation of the extracellular matrix of the fetal membranes and facilitate their rupture under both

  1. Toward Active-Matrix Lab-On-A-Chip: Programmable Electrofluidic control Enaled by Arrayed Oxide Thin Film Transistors

    SciTech Connect

    Noh, Joo Hyon; Noh, Jiyong; Kreit, Eric; Heikenfeld, Jason; Rack, Philip D

    2012-01-01

    Agile micro- and nano-fluidic control is critical to numerous life science and chemical science synthesis as well as kinetic and thermodynamic studies. To this end, we have demonstrated the use of thin film transistor arrays as an active matrix addressing method to control an electrofluidic array. Because the active matrix method minimizes the number of control lines necessary (m + n lines for the m x n element array), the active matrix addressing method integrated with an electrofluidic platform can be a significant breakthrough for complex electrofluidic arrays (increased size or resolution) with enhanced function, agility and programmability. An amorphous indium gallium zinc oxide (a-IGZO) semiconductor active layer is used because of its high mobility of 1-15 cm{sup 2} V{sup -1} s{sup -1}, low-temperature processing and transparency for potential spectroscopy and imaging. Several electrofluidic functionalities are demonstrated using a simple 2 x 5 electrode array connected to a 2 x 5 IGZO thin film transistor array with the semiconductor channel width of 50 {mu}m and mobility of 6.3 cm{sup 2} V{sup -1} s{sup -1}. Additionally, using the TFT device characteristics, active matrix addressing schemes are discussed as the geometry of the electrode array can be tailored to act as a storage capacitor element. Finally, requisite material and device parameters are discussed in context with a VGA scale active matrix addressed electrofluidic platform.

  2. Toward active-matrix lab-on-a-chip: programmable electrofluidic control enabled by arrayed oxide thin film transistors.

    PubMed

    Noh, Joo Hyon; Noh, Jiyong; Kreit, Eric; Heikenfeld, Jason; Rack, Philip D

    2012-01-21

    Agile micro- and nano-fluidic control is critical to numerous life science and chemical science synthesis as well as kinetic and thermodynamic studies. To this end, we have demonstrated the use of thin film transistor arrays as an active matrix addressing method to control an electrofluidic array. Because the active matrix method minimizes the number of control lines necessary (m + n lines for the m×n element array), the active matrix addressing method integrated with an electrofluidic platform can be a significant breakthrough for complex electrofluidic arrays (increased size or resolution) with enhanced function, agility and programmability. An amorphous indium gallium zinc oxide (a-IGZO) semiconductor active layer is used because of its high mobility of 1-15 cm(2) V(-1) s(-1), low-temperature processing and transparency for potential spectroscopy and imaging. Several electrofluidic functionalities are demonstrated using a simple 2 × 5 electrode array connected to a 2 × 5 IGZO thin film transistor array with the semiconductor channel width of 50 μm and mobility of 6.3 cm(2) V(-1) s(-1). Additionally, using the TFT device characteristics, active matrix addressing schemes are discussed as the geometry of the electrode array can be tailored to act as a storage capacitor element. Finally, requisite material and device parameters are discussed in context with a VGA scale active matrix addressed electrofluidic platform.

  3. Development of High Efficacy, Low Cost Phosphorescent Oled Lightning Luminaire

    SciTech Connect

    Michael Hack

    2010-07-09

    In this two year program, UDC together with Armstrong World Industries, Professor Stephen Forrest (University of Michigan) and Professor Mark Thompson (University of Southern California) planned to develop and deliver high efficiency OLED lighting luminaires as part of an integrated ceiling illumination system that exceed the Department of Energy (DOE) 2010 performance projections. Specifically the UDC team in 2010 delivered two prototype OLED ceiling illumination systems, each consisting of four individual OLED lighting panels on glass integrated into Armstrong's novel TechZone open architecture ceiling systems, at an overall system efficacy of 51 lm/W, a CRI = 85 and a projected lifetime to 70% of initial luminance to exceed 10,000 hours. This accomplishment represents a 50% increase in luminaire efficacy and a factor of two in lifetime over that outlined in the solicitation. In addition, the team has also delivered one 15cm x 15cm lighting panel fabricated on a flexible metal foil substrate, demonstrating the possibility using OLEDs in a range of form factors. During this program, our Team has pursued the commercialization of these OLED based ceiling luminaires, with a goal to launch commercial products within the next three years. We have proven that our team is ideally suited to develop these highly novel and efficient solid state lighting luminaires, having both the technical experience and commercial strategy to leverage work performed under this contract. Our calculations show that the success of our program could lead to energy savings of more than 0.5 quads or 8 MMTC (million metric tons of carbon) per year by 2016.

  4. Roll-to-Roll Solution-Processible Small-Molecule OLEDs

    SciTech Connect

    Liu, Jie Jerry

    2012-07-31

    The objective of this program is to develop key knowledge and make critical connections between technologies needed to enable low-cost manufacturing of OLED lighting products. In particular, the program was intended to demonstrate the feasibility of making high performance Small-Molecule OLEDs (SM-OLED) using a roll-to-roll (R2R) wet-coating technique by addressing the following technical risks (1) Whether the wet-coating technique can provide high performance OLEDs, (2) Whether SM-OLED can be made in a R2R manner, (3) What are the requirements for coating equipment, and (4) Whether R2R OLEDs can have the same performance as the lab controls. The program has been managed and executed according to the Program Management Plan (PMP) that was first developed at the beginning of the program and further revised accordingly as the program progressed. Significant progress and risk reductions have been accomplished by the end of the program. Specific achievements include: (1) Demonstrated that wet-coating can provide OLEDs with high LPW and long lifetime; (2) Demonstrated R2R OLEDs can be as efficient as batch controls (Figure 1) (3) Developed & validated basic designs for key equipment necessary for R2R SM-OLEDs; (4) Developed know-hows & specifications on materials & ink formulations critical to wetcoating; (5) Developed key R2R processes for each OLED layer (6) Identified key materials and components such as flexible barrier substrates necessary for R2R OLEDs.

  5. Gelatinolytic activity of matrix metalloproteinase in lung cancer studied using film in situ zymography stamp method.

    PubMed

    Kaji, Masahiro; Moriyama, Satoru; Sasaki, Hidefumi; Saitoh, Yushi; Kiriyama, Masanobu; Fukai, Ichiro; Yamakawa, Yosuke; Mitsui, Akira; Toyama, Tatsuya; Nemori, Ryoichi; Fujii, Yoshitaka

    2003-02-01

    In this study, we investigated activity of matrix metalloproteinase (MMP) of lung cancer by newly developed film in situ zymography (FIZ) stamp method, which allows visual localization of gelatinolytic activity within the cut surface of a tumor. We performed FIZ stamp method and conventional gelatin zymography in 39 resected specimen of lung cancer. The degree of gelatinolytic activity was scored (FIZ score) and correlated with the clinicopathological factors of the tumor. FIZ score of normal lung was very low. Lung cancer tissue had consistently higher FIZ score than the matched normal lung tissue. There were statistically significant differences in the FIZ score according to the pathological stage (P = 0.0015), nodal status (P = 0.0007) and lymphatic invasion (P = 0.0004). Direct correlation was observed between the FIZ score and MMP-2 activity (rho = 0.568, P = 0.0030) as quantitated using conventional gelatin zymography. MMP-2 may play an important role in the lymphatic invasion of lung cancer. FIZ stamp method may be a simple and useful diagnostic aid for the presence of cancer cells in the resected specimen.

  6. ZnO:H indium-free transparent conductive electrodes for active-matrix display applications

    SciTech Connect

    Chen, Shuming Wang, Sisi

    2014-12-01

    Transparent conductive electrodes based on hydrogen (H)-doped zinc oxide (ZnO) have been proposed for active-matrix (AM) display applications. When fabricated with optimal H plasma power and optimal plasma treatment time, the resulting ZnO:H films exhibit low sheet resistance of 200 Ω/◻ and high average transmission of 85% at a film thickness of 150 nm. The demonstrated transparent conductive ZnO:H films can potentially replace indium-tin-oxide and serve as pixel electrodes for organic light-emitting diodes as well as source/drain electrodes for ZnO-based thin-film transistors. Use of the proposed ZnO:H electrodes means that two photomask stages can be removed from the fabrication process flow for ZnO-based AM backplanes.

  7. DP-b99 Modulates Matrix Metalloproteinase Activity and Neuronal Plasticity

    PubMed Central

    Yeghiazaryan, Marine; Rutkowska-Wlodarczyk, Izabela; Konopka, Anna; Wilczyński, Grzegorz M.; Melikyan, Armenuhi; Korkotian, Eduard; Kaczmarek, Leszek; Figiel, Izabela

    2014-01-01

    DP-b99 is a membrane-activated chelator of zinc and calcium ions, recently proposed as a therapeutic agent. Matrix metalloproteinases (MMPs) are zinc-dependent extracellularly operating proteases that might contribute to synaptic plasticity, learning and memory under physiological conditions. In excessive amounts these enzymes contribute to a number of neuronal pathologies ranging from the stroke to neurodegeneration and epileptogenesis. In the present study, we report that DP-b99 delays onset and severity of PTZ-induced seizures in mice, as well as displays neuroprotective effect on kainate excitotoxicity in hippocampal organotypic slices and furthermore blocks morphological reorganization of the dendritic spines evoked by a major neuronal MMP, MMP-9. Taken together, our findings suggest that DP-b99 may inhibit neuronal plasticity driven by MMPs, in particular MMP-9, and thus may be considered as a therapeutic agent under conditions of aberrant plasticity, such as those subserving epileptogenesis. PMID:24918931

  8. Carbon nanotube active-matrix backplanes for conformal electronics and sensors.

    PubMed

    Takahashi, Toshitake; Takei, Kuniharu; Gillies, Andrew G; Fearing, Ronald S; Javey, Ali

    2011-12-14

    In this paper, we report a promising approach for fabricating large-scale flexible and stretchable electronics using a semiconductor-enriched carbon nanotube solution. Uniform semiconducting nanotube networks with superb electrical properties (mobility of ∼20 cm2 V(-1) s(-1) and ION/IOFF of ∼10(4)) are obtained on polyimide substrates. The substrate is made stretchable by laser cutting a honeycomb mesh structure, which combined with nanotube-network transistors enables highly robust conformal electronic devices with minimal device-to-device stochastic variations. The utility of this device concept is demonstrated by fabricating an active-matrix backplane (12×8 pixels, physical size of 6×4 cm2) for pressure mapping using a pressure sensitive rubber as the sensor element.

  9. High performance organic transistor active-matrix driver developed on paper substrate

    NASA Astrophysics Data System (ADS)

    Peng, Boyu; Ren, Xiaochen; Wang, Zongrong; Wang, Xinyu; Roberts, Robert C.; Chan, Paddy K. L.

    2014-09-01

    The fabrication of electronic circuits on unconventional substrates largely broadens their application areas. For example, green electronics achieved through utilization of biodegradable or recyclable substrates, can mitigate the solid waste problems that arise at the end of their lifespan. Here, we combine screen-printing, high precision laser drilling and thermal evaporation, to fabricate organic field effect transistor (OFET) active-matrix (AM) arrays onto standard printer paper. The devices show a mobility and on/off ratio as high as 0.56 cm2V-1s-1 and 109 respectively. Small electrode overlap gives rise to a cut-off frequency of 39 kHz, which supports that our AM array is suitable for novel practical applications. We demonstrate an 8 × 8 AM light emitting diode (LED) driver with programmable scanning and information display functions. The AM array structure has excellent potential for scaling up.

  10. Matrix metalloproteinase 13 mediates nitric oxide activation of endothelial cell migration

    PubMed Central

    López-Rivera, Esther; Lizarbe, Tania R.; Martínez-Moreno, Mónica; López-Novoa, José Miguel; Rodríguez-Barbero, Alicia; Rodrigo, José; Fernández, Ana Patricia; Álvarez-Barrientos, Alberto; Lamas, Santiago; Zaragoza, Carlos

    2005-01-01

    To explore the mechanisms by which NO elicits endothelial cell (EC) migration we used murine and bovine aortic ECs in an in vitro wound-healing model. We found that exogenous or endogenous NO stimulated EC migration. Moreover, migration was significantly delayed in ECs derived from endothelial NO synthase-deficient mice compared with WT murine aortic EC. To assess the contribution of matrix metalloproteinase (MMP)-13 to NO-mediated EC migration, we used RNA interference to silence MMP-13 expression in ECs. Migration was delayed in cells in which MMP-13 was silenced. In untreated cells MMP-13 was localized to caveolae, forming a complex with caveolin-1. Stimulation with NO disrupted this complex and significantly increased extracellular MMP-13 abundance, leading to collagen breakdown. Our findings show that MMP-13 is an important effector of NO-activated endothelial migration. PMID:15728377

  11. MONOLITHIC ACTIVE PIXEL MATRIX WITH BINARY COUNTERS IN AN SOI PROCESS.

    SciTech Connect

    DUPTUCH,G.; YAREMA, R.

    2007-06-07

    The design of a Prototype monolithic active pixel matrix, designed in a 0.15 {micro}m CMOS SOI Process, is presented. The process allowed connection between the electronics and the silicon volume under the layer of buried oxide (BOX). The small size vias traversing through the BOX and implantation of small p-type islands in the n-type bulk result in a monolithic imager. During the acquisition time, all pixels register individual radiation events incrementing the counters. The counting rate is up to 1 MHz per pixel. The contents of counters are shifted out during the readout phase. The designed prototype is an array of 64 x 64 pixels and the pixel size is 26 x 26 {micro}m{sup 2}.

  12. DP-b99 modulates matrix metalloproteinase activity and neuronal plasticity.

    PubMed

    Yeghiazaryan, Marine; Rutkowska-Wlodarczyk, Izabela; Konopka, Anna; Wilczyński, Grzegorz M; Melikyan, Armenuhi; Korkotian, Eduard; Kaczmarek, Leszek; Figiel, Izabela

    2014-01-01

    DP-b99 is a membrane-activated chelator of zinc and calcium ions, recently proposed as a therapeutic agent. Matrix metalloproteinases (MMPs) are zinc-dependent extracellularly operating proteases that might contribute to synaptic plasticity, learning and memory under physiological conditions. In excessive amounts these enzymes contribute to a number of neuronal pathologies ranging from the stroke to neurodegeneration and epileptogenesis. In the present study, we report that DP-b99 delays onset and severity of PTZ-induced seizures in mice, as well as displays neuroprotective effect on kainate excitotoxicity in hippocampal organotypic slices and furthermore blocks morphological reorganization of the dendritic spines evoked by a major neuronal MMP, MMP-9. Taken together, our findings suggest that DP-b99 may inhibit neuronal plasticity driven by MMPs, in particular MMP-9, and thus may be considered as a therapeutic agent under conditions of aberrant plasticity, such as those subserving epileptogenesis.

  13. High performance organic transistor active-matrix driver developed on paper substrate

    PubMed Central

    Peng, Boyu; Ren, Xiaochen; Wang, Zongrong; Wang, Xinyu; Roberts, Robert C.; Chan, Paddy K. L.

    2014-01-01

    The fabrication of electronic circuits on unconventional substrates largely broadens their application areas. For example, green electronics achieved through utilization of biodegradable or recyclable substrates, can mitigate the solid waste problems that arise at the end of their lifespan. Here, we combine screen-printing, high precision laser drilling and thermal evaporation, to fabricate organic field effect transistor (OFET) active-matrix (AM) arrays onto standard printer paper. The devices show a mobility and on/off ratio as high as 0.56 cm2V−1s−1 and 109 respectively. Small electrode overlap gives rise to a cut-off frequency of 39 kHz, which supports that our AM array is suitable for novel practical applications. We demonstrate an 8 × 8 AM light emitting diode (LED) driver with programmable scanning and information display functions. The AM array structure has excellent potential for scaling up. PMID:25234244

  14. Expression and activity of matrix metalloproteinases in the uterus of bitches after spontaneous and induced abortion.

    PubMed

    Kanca, H; Walter, I; Miller, I; Schäfer-Somi, S; Izgur, H; Aslan, S

    2011-04-01

    Aim of this study was to determine the intrauterine activity of matrix metalloproteinases (MMP)-2 and -9 after cessation of the local effect of progesterone. For this purpose, pregnancy was terminated in 10 bitches at mid-gestation with the progesterone receptor antagonist aglepristone (10 mg/kg body weight, sc, Alizine®; Virbac, France) at two subsequent days (group IRA = induced resorption/abortion). The IRA group was divided into two subgroups (Group I, n = 5, days 25-35 of pregnancy; group II, n = 5, days 36-45). Five further bitches were introduced with beginning abortion (group SRA = spontaneous resorption/abortion). Seven healthy bitches between day 25 and 45 of gestation served as controls. After ovariohysterectomy at the end of abortion and between days 25 and 45 of gestation, respectively, the distribution and activity of collagenases were investigated by immunohistochemistry and gelatin zymography. At placental sites, MMP-2 activity in the endometrium was significantly lower in IRA groups than in the SRA group (33.7 ± 11.8% and 39.3 ± 5.4% vs 52.2 ± 10.2%, p < 0.05); however, MMP-2 expression was lowest in the control group (control: 21.4 ± 6.3%; p < 0.01) and similarly in the myometrium (controls: 13.1 ± 2.5%; p < 0.05). MMP-9 activity was also lower in the endometrium and myometrium of the control group in comparison to SRA and IRA groups (11.8 ± 3.2%; p < 0.01 and 28.4 ± 32.8%; p < 0.05). At interplacental sites, the amount of active collagenases in the myometrium was significantly lower in the control group. It is concluded that the blockade of the biological progesterone effect was associated with an increase in activity of both collagenases.

  15. Real-time monitoring of matrix metalloproteinase-9 collagenolytic activity with a surface plasmon resonance biosensor.

    PubMed

    Shoji, Atsushi; Kabeya, Mitsutaka; Sugawara, Masao

    2011-12-01

    We describe a simple method for real-time monitoring of matrix metalloproteinase-9 (MMP-9) collagenolytic activity for native triple helical collagen IV with a surface plasmon resonance (SPR) biosensor. The proteolytic activity of MMP-9 is measured as a decrease in the SPR signal resulting from the cleavage of collagen IV immobilized on the sensor surface. The kinetic parameters of full-length MMP-9 and its catalytic domain-catalytic constant (k(cat)), association rate constant (k(a)), and dissociation rate constant (k(d))-were estimated by the SPR method. The presence of sodium chloride and a nonionic detergent Brij-35 in a reaction solution led to the lower collagenolytic activity of MMP-9, whereas they suppressed the nonspecific interaction between MMP-9 and a cysteamine-modified chip. The comparison of kinetic parameters between MMP-9 and its catalytic domain revealed that the association constant of MMP-9 is much larger than that of the catalytic domain, suggesting that the interplay among hemopexin-like domain, fibronectin type II repeats motif, and linker region (O-glycosylated domain) plays an important role in recognizing collagen IV.

  16. Pyrophosphate Stimulates Differentiation, Matrix Gene Expression and Alkaline Phosphatase Activity in Osteoblasts

    PubMed Central

    Pujari-Palmer, Michael; Pujari-Palmer, Shiuli; Lu, Xi; Lind, Thomas; Melhus, Håkan; Engstrand, Thomas; Karlsson-Ott, Marjam; Engqvist, Hakan

    2016-01-01

    Pyrophosphate is a potent mitogen, capable of stimulating proliferation in multiple cell types, and a critical participant in bone mineralization. Pyrophosphate can also affect the resorption rate and bioactivity of orthopedic ceramics. The present study investigated whether calcium pyrophosphate affected proliferation, differentiation and gene expression in early (MC3T3 pre-osteoblast) and late stage (SAOS-2 osteosarcoma) osteoblasts. Pyrophosphate stimulated peak alkaline phosphatase activity by 50% and 150% at 100μM and 0.1μM in MC3T3, and by 40% in SAOS-2. The expression of differentiation markers collagen 1 (COL1), alkaline phosphatase (ALP), osteopontin (OPN), and osteocalcin (OCN) were increased by an average of 1.5, 2, 2 and 3 fold, by high concentrations of sodium pyrophosphate (100μM) after 7 days of exposure in MC3T3. COX-2 and ANK expression did not differ significantly from controls in either treatment group. Though both high and low concentrations of pyrophosphate stimulate ALP activity, only high concentrations (100μM) stimulated osteogenic gene expression. Pyrophosphate did not affect proliferation in either cell type. The results of this study confirm that chronic exposure to pyrophosphate exerts a physiological effect upon osteoblast differentiation and ALP activity, specifically by stimulating osteoblast differentiation markers and extracellular matrix gene expression. PMID:27701417

  17. Proliferative effects of apical, but not basal, matrix metalloproteinase-7 activity in polarized MDCK cells

    SciTech Connect

    Harrell, Permila C.; McCawley, Lisa J.; Fingleton, Barbara; McIntyre, J. Oliver; Matrisian, Lynn M. . E-mail: lynn.matrisian@vanderbilt.edu

    2005-02-15

    Matrix metalloproteinase-7 (MMP-7) is primarily expressed in glandular epithelium. Therefore, its mechanism of action may be influenced by its regulated vectorial release to either the apical and/or basolateral compartments, where it would act on its various substrates. To gain a better understanding of where MMP-7 is released in polarized epithelium, we have analyzed its pattern of secretion in polarized MDCK cells expressing stably transfected human MMP-7 (MDCK-MMP-7), and HCA-7 and Caco2 human colon cancer cell lines. In all cell lines, latent MMP-7 was secreted to both cellular compartments, but was 1.5- to 3-fold more abundant in the basolateral compartment as compared to the apical. However, studies in the MDCK system demonstrated that MMP-7 activity was 2-fold greater in the apical compartment of MDCK-MMP-7{sup HIGH}-polarized monolayers, which suggests the apical co-release of an MMP-7 activator. In functional assays, MMP-7 over-expression increased cell saturation density as a result of increased cell proliferation with no effect on apoptosis. Apical MMP-7 activity was shown to be responsible for the proliferative effect, which occurred, as demonstrated by media transfer experiments, through cleavage of an apical substrate and not through the generation of a soluble factor. Taken together, our findings demonstrate the importance of MMP-7 secretion in relation to its mechanism of action when expressed in a polarized epithelium.

  18. Osteoblast-released Matrix Vesicles, Regulation of Activity and Composition by Sulfated and Non-sulfated Glycosaminoglycans*

    PubMed Central

    Schmidt, Johannes R.; Kliemt, Stefanie; Preissler, Carolin; Moeller, Stephanie; von Bergen, Martin; Hempel, Ute; Kalkhof, Stefan

    2016-01-01

    Our aging population has to deal with the increasing threat of age-related diseases that impair bone healing. One promising therapeutic approach involves the coating of implants with modified glycosaminoglycans (GAGs) that mimic the native bone environment and actively facilitate skeletogenesis. In previous studies, we reported that coatings containing GAGs, such as hyaluronic acid (HA) and its synthetically sulfated derivative (sHA1) as well as the naturally low-sulfated GAG chondroitin sulfate (CS1), reduce the activity of bone-resorbing osteoclasts, but they also induce functions of the bone-forming cells, the osteoblasts. However, it remained open whether GAGs influence the osteoblasts alone or whether they also directly affect the formation, composition, activity, and distribution of osteoblast-released matrix vesicles (MV), which are supposed to be the active machinery for bone formation. Here, we studied the molecular effects of sHA1, HA, and CS1 on MV activity and on the distribution of marker proteins. Furthermore, we used comparative proteomic methods to study the relative protein compositions of isolated MVs and MV-releasing osteoblasts. The MV proteome is much more strongly regulated by GAGs than the cellular proteome. GAGs, especially sHA1, were found to severely impact vesicle-extracellular matrix interaction and matrix vesicle activity, leading to stronger extracellular matrix formation and mineralization. This study shows that the regulation of MV activity is one important mode of action of GAGs and provides information on underlying molecular mechanisms. PMID:26598647

  19. Matrix metalloproteinase-driven endochondral fracture union proceeds independently of osteoclast activity.

    PubMed

    McDonald, Michelle M; Morse, Alyson; Mikulec, Kathy; Peacock, Lauren; Baldock, Paul A; Kostenuik, Paul J; Little, David G

    2013-07-01

    As new insights into the complexities of endochondral fracture repair emerge, the temporal role of osteoclast activity remains ambiguous. With numerous antiresorptive agents available to treat bone disease, understanding their impact on bone repair is vital. Further, in light of recent work suggesting osteoclast activity may not be necessary during early endochondral fracture union, we hypothesize instead a pivotal role of matrix metalloproteinase (MMP) secreting cells in driving this process. Although the role of MMPs in fracture healing has been examined, no directly comparative experiments exist. We examined a number of antiresorptive treatments to either block osteoclast activity, including the potent bisphosphonates zoledronic acid (ZA) and clodronate (CLOD), which work via differing mechanisms, or antagonize osteoclastogenesis with recombinant OPG (HuOPG-Fc), comparing these directly to an inhibitor of MMP activity (MMI270). Endochondral ossification to union occurred normally in all antiresorptive groups. In contrast, MMP inhibition greatly impaired endochondral union, significantly delaying cartilage callus removal. MMP inhibition also produced smaller, denser hard calluses. Hard callus remodeling was, as expected, delayed with ZA, CLOD, and OPG treatment at 4 and 6 weeks, resulting in larger, more mineralized calluses at 6 weeks. As a result of reduced hard callus turnover, bone formation was reduced with antiresorptive agents at these time points. These results confirm that the achievement of endochondral fracture union occurs independently of osteoclast activity. Alternatively, MMP secretion by invading cells is obligatory to endochondral union. This study provides new insight into cellular contributions to bone repair and may abate concerns regarding antiresorptive therapies impeding initial fracture union.

  20. Distribution and relative activity of matrix metalloproteinase-2 in human coronal dentin

    PubMed Central

    Boushell, Lee W; Kaku, Masaru; Mochida, Yoshiyuki; Yamauchi, Mitsuo

    2011-01-01

    The presence of matrix metalloproteinase-2 (MMP-2) in dentin has been reported, but its distribution and activity level in mature human coronal dentin are not well understood. The purpose of this study was to determine the MMP-2 distribution and relative activity in demineralized dentin. Crowns of twenty eight human molars were sectioned into inner (ID), middle (MD), and outer dentin (OD) regions and demineralized. MMP-2 was extracted with 0.33 mol·L−1 EDTA/2 mol·L−1 guanidine-HCl, pH 7.4, and MMP-2 concentration was estimated with enzyme-linked immunoabsorbant assay (ELISA). Further characterization was accomplished by Western blotting analysis and gelatin zymography. The mean concentrations of MMP-2 per mg dentin protein in the dentin regions were significantly different (P=0.043): 0.9 ng (ID), 0.4 ng (MD), and 2.2 ng (OD), respectively. The pattern of MMP-2 concentration was OD>ID>MD. Western blotting analysis detected ∼66 and ∼72 kDa immunopositive proteins corresponding to pro- and mature MMP-2, respectively, in the ID and MD, and a ∼66 kDa protein in the OD. Gelatinolytic activity consistent with MMP-2 was detected in all regions. Interestingly, the pattern of levels of Western blot immunodetection and gelatinolytic activity was MD>ID>OD. The concentration of MMP-2 in human coronal dentin was highest in the region of dentin that contains the dentinoenamel junction and least in the middle region of dentin. However, levels of Western blot immunodetection and gelatinolytic activity did not correlate with the estimated regional concentrations of MMP-2, potentially indicating region specific protein interactions. PMID:22010577

  1. Expression of matrix metalloproteinases during rat skin wound healing: evidence that membrane type-1 matrix metalloproteinase is a stromal activator of pro-gelatinase A.

    PubMed

    Okada, A; Tomasetto, C; Lutz, Y; Bellocq, J P; Rio, M C; Basset, P

    1997-04-07

    Skin wound healing depends on cell migration and extracellular matrix remodeling. Both processes, which are necessary for reepithelization and restoration of the underlying connective tissue, are believed to involve the action of extracellular proteinases. We screened cDNA libraries and we found that six matrix metalloproteinase genes were highly expressed during rat skin wound healing. They were namely those of stromelysin 1, stromelysin 3, collagenase 3, gelatinase A (GelA), gelatinase B, and membrane type-1 matrix metalloproteinase (MT1-MMP). The expression kinetics of these MMP genes, the tissue distribution of their transcripts, the results of cotransfection experiments in COS-1 cells, and zymographic analyses performed using microdissected rat wound tissues support the possibility that during cutaneous wound healing pro-GelA and pro-gelatinase B are activated by MT1-MMP and stromelysin 1, respectively. Since MT1-MMP has been demonstrated to be a membrane-associated protein (Sato, H., T. Takino, Y. Okada, J. Cao, A. Shinagawa, E. Yamamoto, and M. Seiki. 1994. Nature (Lond.). 370: 61-65), our finding that GelA and MT1-MMP transcripts were expressed in stromal cells exhibiting a similar tissue distribution suggests that MT1-MMP activates pro-GelA at the stromal cell surface. This possibility is further supported by our observation that the processing of pro-GelA to its mature form correlated to the detection of MT1-MMP in cell membranes of rat fibroblasts expressing the MT1-MMP and GelA genes. These observations, together with the detection of high levels of the mature GelA form in the granulation tissue but not in the regenerating epidermis, suggest that MT1-MMP and GelA contribute to the restoration of connective tissue during rat skin wound healing.

  2. Human retinal pigment epithelial lysis of extracellular matrix: functional urokinase plasminogen activator receptor, collagenase, and elastase.

    PubMed Central

    Elner, Susan G

    2002-01-01

    PURPOSE: To show (1) human retinal pigment epithelial (HRPE) expression of functional urokinase plasminogen activator receptor (uPAR; CD87), (2) HRPE secretion of collagenase and elastase, (3) uPAR-dependent HRPE migration, and (4) uPAR expression in diseased human retinal tissue. METHODS: Immunohistochemistry for uPAR was performed on cultured HRPE cells and in sections of human retina. Double-immunofluorescent staining of live human RPE cells with anti-CR3 antibody (CD11b) was performed to demonstrate the physical proximity of this beta 2 integrin with uPAR and determine whether associations were dependent on RPE confluence and polarity. Extracellular proteolysis by HRPE uPAR was evaluated using fluorescent bodipy-BSA and assessed for specificity by plasminogen activator inhibitor-1 (PAI-1) inhibition. The effect of interleukin-1 beta (IL-1 beta) on uPAR expression was assessed. Collagenase and elastase secretion by unstimulated and IL-1-stimulated HRPE cells was measured by 3H-labelled collagen and elastin cleavage. HRPE-associated collagenase was also assessed by cleavage of fluorescent DQ-collagen and inhibited by phenanthroline. Using an extracellular matrix assay, the roles of uPAR and collagenase in HRPE migration were assessed. RESULTS: Immunoreactive uPAR was detected on cultured HRPE cells and increased by IL-1. On elongated, live HRPE cells, uPAR dissociated from CD11b (CR3) and translocated to anterior poles of migrating cells. Extracellular proteolysis was concentrated at sites of uPAR expression and specifically inhibited by PAI-1. Cultured HRPE cells secreted substantial, functional collagenase and elastase. IL-1 upregulated uPAR, collagenase, and elastase activities. Specific inhibition of uPAR, and to a lesser degree collagenase, reduced HRPE migration in matrix/gel assays. Immunoreactive uPAR was present along the HRPE basolateral membrane in retinal sections and in sections of diseased retinal tissue. CONCLUSIONS: HRPE cells express functional u

  3. Bilayer Membrane Modulation of Membrane Type 1 Matrix Metalloproteinase (MT1-MMP) Structure and Proteolytic Activity

    PubMed Central

    Cerofolini, Linda; Amar, Sabrina; Lauer, Janelle L.; Martelli, Tommaso; Fragai, Marco; Luchinat, Claudio; Fields, Gregg B.

    2016-01-01

    Cell surface proteolysis is an integral yet poorly understood physiological process. The present study has examined how the pericellular collagenase membrane-type 1 matrix metalloproteinase (MT1-MMP) and membrane-mimicking environments interplay in substrate binding and processing. NMR derived structural models indicate that MT1-MMP transiently associates with bicelles and cells through distinct residues in blades III and IV of its hemopexin-like domain, while binding of collagen-like triple-helices occurs within blades I and II of this domain. Examination of simultaneous membrane interaction and triple-helix binding revealed a possible regulation of proteolysis due to steric effects of the membrane. At bicelle concentrations of 1%, enzymatic activity towards triple-helices was increased 1.5-fold. A single mutation in the putative membrane interaction region of MT1-MMP (Ser466Pro) resulted in lower enzyme activation by bicelles. An initial structural framework has thus been developed to define the role(s) of cell membranes in modulating proteolysis. PMID:27405411

  4. Cellular aspartyl proteases promote the unconventional secretion of biologically active HIV-1 matrix protein p17

    PubMed Central

    Caccuri, Francesca; Iaria, Maria Luisa; Campilongo, Federica; Varney, Kristen; Rossi, Alessandro; Mitola, Stefania; Schiarea, Silvia; Bugatti, Antonella; Mazzuca, Pietro; Giagulli, Cinzia; Fiorentini, Simona; Lu, Wuyuan; Salmona, Mario; Caruso, Arnaldo

    2016-01-01

    The human immune deficiency virus type 1 (HIV-1) matrix protein p17 (p17), although devoid of a signal sequence, is released by infected cells and detected in blood and in different organs and tissues even in HIV-1-infected patients undergoing successful combined antiretroviral therapy (cART). Extracellularly, p17 deregulates the function of different cells involved in AIDS pathogenesis. The mechanism of p17 secretion, particularly during HIV-1 latency, still remains to be elucidated. A recent study showed that HIV-1-infected cells can produce Gag without spreading infection in a model of viral latency. Here we show that in Gag-expressing cells, secretion of biologically active p17 takes place at the plasma membrane and occurs following its interaction with phosphatidylinositol-(4,5)-bisphosphate and its subsequent cleavage from the precursor Gag (Pr55Gag) operated by cellular aspartyl proteases. These enzymes operate a more complex Gag polypeptide proteolysis than the HIV-1 protease, thus hypothetically generating slightly truncated or elongated p17s in their C-terminus. A 17 C-terminal residues excised p17 was found to be structurally and functionally identical to the full-length p17 demonstrating that the final C-terminal region of p17 is irrelevant for the protein’s biological activity. These findings offer new opportunities to identify treatment strategies for inhibiting p17 release in the extracellular microenvironment. PMID:27905556

  5. Cell-mediated degradation of type IV collagen and gelatin films is dependent on the activation of matrix metalloproteinases.

    PubMed Central

    Atkinson, S J; Ward, R V; Reynolds, J J; Murphy, G

    1992-01-01

    The ability of normal rabbit dermal fibroblasts to degrade films of type IV collagen and gelatin when stimulated by phorbol ester was shown to be dependent on the induction, secretion and activation of 95 kDa gelatinase B and the secretion and activation of 72 kDa gelatinase A and stromelysin. Degradation was inhibited by exogenous human recombinant tissue inhibitor of metalloproteinases-1, specific antibodies to gelatinase and stromelysin and by the reactive-oxygen-metabolite inhibitor catalase. We discuss the various pathways for activation of matrix metalloproteinases in this model system and conclude that, although plasmin may play a key role in the activation of gelatinase B and stromelysin, gelatinase A is activated by a mechanism which has yet to be elucidated. The involvement of oxygen radicals in the direct activation of matrix metalloproteinases in this model is thought to be unlikely. Images Fig. 2. Fig. 3. Fig. 4. PMID:1463464

  6. Withaferin A inhibits matrix metalloproteinase-9 activity by suppressing the Akt signaling pathway.

    PubMed

    Lee, Dae Hyung; Lim, In-Hye; Sung, Eon-Gi; Kim, Joo-Young; Song, In-Hwan; Park, Yoon Ki; Lee, Tae-Jin

    2013-08-01

    Withaferin A (Wit A), a steroidal lactone isolated from Withania somnifera, exhibits anti-inflammatory, immuno-modulatory and anti-angiogenic properties and antitumor activities. In the present study, we investigated the effects of Wit A on protease-mediated invasiveness of the human metastatic cancer cell lines Caski and SK-Hep1. We found that treatment with Wit A resulted in marked inhibition of the TGF‑β‑induced increase in expression and activity of matrix metalloproteinase (MMP)‑9 in Caski cell line. These effects of Wit A were dose-dependent and showed a correlation with suppression of MMP‑9 mRNA expression levels. Treatment with Wit A resulted in an ~1.6-fold induction of MMP-9 promoter activity, which was also suppressed by treatment with Wit A in Caski cells. We found that treatment with Wit A resulted in inhibition of TGF‑β‑induced phosphorylation of Akt, which was involved in the downregulation of expression of MMP-9 at the protein level. Introduction with constitutively active (CA)‑Akt resulted in a partial increase in the secretion of TGF-β-induced MMP-9 blocked by treatment with Wit A in Caski cells. According to these results, Wit A may inhibit the invasive and migratory abilities of Caski cells through a reduction in MMP-9 expression through suppression of the pAkt signaling pathway. These findings indicate that use of Wit A may be an effective strategy for control of metastasis and invasiveness of tumors.

  7. Acrolein activates matrix metalloproteinases by increasing reactive oxygen species in macrophages

    SciTech Connect

    O'Toole, Timothy E. Zheng Yuting; Hellmann, Jason; Conklin, Daniel J.; Barski, Oleg; Bhatnagar, Aruni

    2009-04-15

    Acrolein is a ubiquitous component of environmental pollutants such as automobile exhaust, cigarette, wood, and coal smoke. It is also a natural constituent of several foods and is generated endogenously during inflammation or oxidation of unsaturated lipids. Because increased inflammation and episodic exposure to acrolein-rich pollutants such as traffic emissions or cigarette smoke have been linked to acute myocardial infarction, we examined the effects of acrolein on matrix metalloproteinases (MMPs), which destabilize atherosclerotic plaques. Our studies show that exposure to acrolein resulted in the secretion of MMP-9 from differentiated THP-1 macrophages. Acrolein-treatment of macrophages also led to an increase in reactive oxygen species (ROS), free intracellular calcium ([Ca{sup 2+}]{sub i}), and xanthine oxidase (XO) activity. ROS production was prevented by allopurinol, but not by rotenone or apocynin and by buffering changes in [Ca{sup 2+}]{sub I} with BAPTA-AM. The increase in MMP production was abolished by pre-treatment with the antioxidants Tiron and N-acetyl cysteine (NAC) or with the xanthine oxidase inhibitors allopurinol or oxypurinol. Finally, MMP activity was significantly stimulated in aortic sections from apoE-null mice containing advanced atherosclerotic lesions after exposure to acrolein ex vivo. These observations suggest that acrolein exposure results in MMP secretion from macrophages via a mechanism that involves an increase in [Ca{sup 2+}]{sub I}, leading to xanthine oxidase activation and an increase in ROS production. ROS-dependent activation of MMPs by acrolein could destabilize atherosclerotic lesions during brief episodes of inflammation or pollutant exposure.

  8. Sync Matrix

    SciTech Connect

    Metz, William C.; Metz, W. Chris; Mitrani, Jacques E.; Hewett, Jr., Paul L.; Jones, Christopher A.

    2004-12-31

    Sync Matrix provides a graphic display of the relationships among all of the response activities of each jurisdiction. This is accomplished through software that organizes and displays the activities by jurisdiction, function, and time for easy review and analysis. The software can also integrate the displays of multiple jurisdictions to allow examination of the total response.

  9. INK-JET PRINTING OF PF6 FOR OLED APPLICATIONS

    SciTech Connect

    Burrasca, G.; Fasolino, T.; Miscioscia, R.; Nenna, G.; Vacca, P.; Villani, F.; Minarini, C.; Della Sala, D.

    2008-08-28

    In the last years there has been much interest in applying ink-jet printing (IJP) technology to the deposition of several materials for organic electronics applications, including metals, polymers and nanoparticles dispersions on flexible substrates. The aim of this work is to study the effect of ink-jet deposition of polymer films in the manufacturing of OLED devices comparing their performances to standard technologies. The ink-jet printed polymer is introduced in an hybrid structure in which other layers are deposited by vacuum thermal evaporation. The electrical and optical properties of the obtained devices are investigated.OLEDs with the same structure were fabricated by spin-coating a polymer film by the same solution used as ink. Results have been compared to the above ones to determine how the deposition method affects the device optoelectronic properties.

  10. High efficiency and stable white OLED using a single emitter

    SciTech Connect

    Li, Jian

    2016-01-18

    The ultimate objective of this project was to demonstrate an efficient and stable white OLED using a single emitter on a planar glass substrate. The focus of the project is on the development of efficient and stable square planar phosphorescent emitters and evaluation of such class of materials in the device settings. Key challenges included improving the emission efficiency of molecular dopants and excimers, controlling emission color of emitters and their excimers, and improving optical and electrical stability of emissive dopants. At the end of this research program, the PI has made enough progress to demonstrate the potential of excimer-based white OLED as a cost-effective solution for WOLED panel in the solid state lighting applications.

  11. Novel bipolar bathophenanthroline containing hosts for highly efficient phosphorescent OLEDs.

    PubMed

    Ge, Ziyi; Hayakawa, Teruaki; Ando, Shinji; Ueda, Mitsuru; Akiike, Toshiyuki; Miyamoto, Hidetoshi; Kajita, Toru; Kakimoto, Masa-aki

    2008-02-07

    The electronic structures of eight bathophenanthroline derivatives were elucidated by DFT calculations, and four representatives of which CZBP, m-CZBP, m-TPAP, and BPABP were synthesized and employed as the hosts to afford highly efficient phosphorescent OLEDs. The calculated molecular orbital energies agree well with the experimental results, which further demonstrates that the localization of HOMO and LUMO at the respective hole- and electron-transporting moieties is desirable in bipolar molecular designs.

  12. Atmospheric-Pressure Cold Plasmas Used to Embed Bioactive Compounds in Matrix Material for Active Packaging of Fruits and Vegetables

    NASA Astrophysics Data System (ADS)

    Fernandez, Sulmer; Pedrow, Patrick; Powers, Joseph; Pitts, Marvin

    2009-10-01

    Active thin film packaging is a technology with the potential to provide consumers with new fruit and vegetable products-if the film can be applied without deactivating bioactive compounds.Atmospheric pressure cold plasma (APCP) processing can be used to activate monomer with concomitant deposition of an organic plasma polymerized matrix material and to immobilize a bioactive compound all at or below room temperature.Aims of this work include: 1) immobilize an antimicrobial in the matrix; 2) determine if the antimicrobial retains its functionality and 3) optimize the reactor design.The plasma zone will be obtained by increasing the voltage on an electrode structure until the electric field in the feed material (argon + monomer) yields electron avalanches. Results will be described using Red Delicious apples.Prospective matrix precursors are vanillin and cinnamic acid.A prospective bioactive compound is benzoic acid.

  13. Improvement of OLED properties with anti-reflection coatings

    NASA Astrophysics Data System (ADS)

    Liu, Chunling; Wang, Dongmei; Zhao, Lei; Jiang, Wenlong; Qin, Zhengkun; Wang, Chunwu

    2010-11-01

    An anti-reflection (AR) coating system was inserted between the anode (ITO) and the glass substrate in the red light organic electroluminescent devices (OLED) for the structure being K9/ITO/NPB (60nm)/DCJTB (0.3nm)/Alq3 (60nm)/ LiF(0.3nm)/Al. The AR film system structure was K9/TiO2/Al2O3/2-ITO, and the optical thicknesses of TiO2 and Al2O3 coatings were also quarter wave length. The results indicated that the maximum transmissivity of AR coating was by 95 %( 610nm); it increased by 8% compared with only using ITO as AR coating. The average luminance increased by about 30%, the average energy efficiency increased by about 60%, while reducing the threshold voltage of the devices. The processing is simple and high efficient, and can change AR coating structure according to the OLED device different emission wavelength, therefore, can be widely applied to the OLED devices.

  14. Modulation of CD147-induced matrix metalloproteinase activity: role of CD147 N-glycosylation.

    PubMed

    Huang, Wan; Luo, Wen-Juan; Zhu, Ping; Tang, Juan; Yu, Xiao-Ling; Cui, Hong-Yong; Wang, Bin; Zhang, Yang; Jiang, Jian-Li; Chen, Zhi-Nan

    2013-01-15

    Degradation of the basement membrane by MMPs (matrix metalloproteinases) is one of the most critical steps in tumour progression. CD147 is a tumour-associated antigen that plays a key regulatory role for MMP activities. In the present study, mass spectrum analysis demonstrated that the purified native CD147 from human lung cancer tissue was N-glycosylated and contained a series of high-mannose and complex-type N-linked glycan structures. Moreover, native glycosylated CD147 existed exclusively as oligomers in solution and directly stimulated MMP production more efficiently than non-glycosylated prokaryotic CD147. The glycosylation site mutation results indicated that, among three N-glycan attachment sites, the N152Q mutants were retained in the endoplasmic reticulum and unfolded protein response signalling was activated. This improper intracellular accumulation impaired its MMP-inducing activity. Increased β1,6-branching of N-glycans as a result of overexpression of GnT-V (N-acetylglucosaminyltransferase V) plays an important role in tumour metastasis. In the present study, we identified CD147 as a target protein of GnT-V and found that overexpression of GnT-V resulted in an elevated level of CD147 at the plasma membrane and in cell-conditioned medium, thereby increasing the induction of MMPs. The present study reveals the important role of N-glycosylation of CD147 in its biological function and implied that targeting aberrant β1,6-branching of N-glycans on CD147 would be valuable for the development of novel therapeutic modalities against carcinoma.

  15. Matrix immobilization enhances the tissue repair activity of growth factor gene therapy vectors.

    PubMed

    Doukas, J; Chandler, L A; Gonzalez, A M; Gu, D; Hoganson, D K; Ma, C; Nguyen, T; Printz, M A; Nesbit, M; Herlyn, M; Crombleholme, T M; Aukerman, S L; Sosnowski, B A; Pierce, G F

    2001-05-01

    Although growth factor proteins display potent tissue repair activities, difficulty in sustaining localized therapeutic concentrations limits their therapeutic activity. We reasoned that enhanced histogenesis might be achieved by combining growth factor genes with biocompatible matrices capable of immobilizing vectors at delivery sites. When delivered to subcutaneously implanted sponges, a platelet-derived growth factor B-encoding adenovirus (AdPDGF-B) formulated in a collagen matrix enhanced granulation tissue deposition 3- to 4-fold (p < or = 0.0002), whereas vectors encoding fibroblast growth factor 2 or vascular endothelial growth factor promoted primarily angiogenic responses. By day 8 posttreatment of ischemic excisional wounds, collagen-formulated AdPDGF-B enhanced granulation tissue and epithelial areas up to 13- and 6-fold (p < 0.009), respectively, and wound closure up to 2-fold (p < 0.05). At longer times, complete healing without excessive scar formation was achieved. Collagen matrices were shown to retain both vector and transgene products within delivery sites, enabling the transduction and stimulation of infiltrating repair cells. Quantitative PCR and RT-PCR demonstrated both vector DNA and transgene mRNA within wound beds as late as 28 days posttreatment. By contrast, aqueous formulations allowed vector seepage from application sites, leading to PDGF-induced hyperplasia in surrounding tissues but not wound beds. Finally, repeated applications of PDGF-BB protein were required for neotissue induction approaching equivalence to a single application of collagen-immobilized AdPDGF-B, confirming the utility of this gene transfer approach. Overall, these studies demonstrate that immobilizing matrices enable the controlled delivery and activity of tissue promoting genes for the effective regeneration of injured tissues.

  16. Phenotypic differences in matrix metalloproteinase 2 activity between fibroblasts from 3 bovine muscles.

    PubMed

    Archile-Contreras, A C; Mandell, I B; Purslow, P P

    2010-12-01

    Different muscles in a beef carcass are known to respond differently to the same stimulus or animal growth pattern or both. This may complicate the search by the meat industry for production methods to render meat tender. One of the major differences between muscles in the same carcass is in the expression of intramuscular connective tissue. Current study investigates the existence of a phenotypic difference among fibroblasts from 3 bovine skeletal muscles as exemplified by the expression of matrix metalloproteinases (MMP) the main enzymes responsible for connective tissue turnover. The sensitivity of phenotypic differences to cell culture conditions (passage number, presence of growth factors from fetal serum) was also examined. Fibroblasts, the main cells responsible for the production and turnover of collagen were isolated from LM, semitendinosus (STN), and sternomandibularis (SMD) muscles from a bull calf and grown in DMEM, 10% fetal bovine serum, and 5% CO(2). Cell doubling times, survival time, resting expression, and activity of MMP and the effect of serum withdrawal in the culture media on MMP expression and activity were determined for each cell line during 15 passages. Fibroblasts isolated from the 3 muscles had different growth potentials. The shortest (P < 0.0001) cell doubling times for almost every passage were found in cells from STN muscle. Cells from the LM had a shorter (P < 0.0001) survival time in comparison with STN and SMD. Cells derived from the STN had greater values (P > 0.05) of MMP-2 activity in comparison with LM and SMD cells until passage 4. At passage 15, no activity was detected for any cell line. Serum withdrawal generally reduced MMP-2 activation but did not eliminate differences in activity between fibroblasts from the 3 muscles. These results suggest that fibroblasts from different locations are phenotypically different and may respond differently to the same growth or nutritional stimulus in vitro. This may be related to in vivo

  17. Vitamin D Inhibits Expression and Activity of Matrix Metalloproteinase in Human Lung Fibroblasts (HFL-1) Cells

    PubMed Central

    Kim, Seo Hwa; Baek, Moon Seong; Yoon, Dong Sik; Park, Jong Seol; Yoon, Byoung Wook; Oh, Byoung Su; Park, Jinkyeong

    2014-01-01

    Background Low levels of serum vitamin D is associated with several lung diseases. The production and activation of matrix metalloproteinases (MMPs) may play an important role in the pathogenesis of emphysema. The aim of the current study therefore is to investigate if vitamin D modulates the expression and activation of MMP-2 and MMP-9 in human lung fibroblasts (HFL-1) cells. Methods HFL-1 cells were cast into three-dimensional collagen gels and stimulated with or without interleukin-1β (IL-1β) in the presence or absence of 100 nM 25-hydroxyvitamin D (25(OH)D) or 1,25-dihydroxyvitamin D (1,25(OH)2D) for 48 hours. Trypsin was then added into the culture medium in order to activate MMPs. To investigate the activity of MMP-2 and MMP-9, gelatin zymography was performed. The expression of the tissue inhibitor of metalloproteinase (TIMP-1, TIMP-2) was measured by enzyme-linked immunosorbent assay. Expression of MMP-9 mRNA and TIMP-1, TIMP-2 mRNA was quantified by real time reverse transcription polymerase chain reaction. Results IL-1β significantly stimulated MMP-9 production and mRNA expression. Trypsin converted latent MMP-2 and MMP-9 into their active forms of MMP-2 (66 kDa) and MMP-9 (82 kDa) within 24 hours. This conversion was significantly inhibited by 25(OH)D (100 nM) and 1,25(OH)2D (100 nM). The expression of MMP-9 mRNA was also significantly inhibited by 25(OH)D and 1,25(OH)2D. Conclusion Vitamin D, 25(OH)D, and 1,25(OH)2D play a role in regulating human lung fibroblast functions in wound repair and tissue remodeling through not only inhibiting IL-1β stimulated MMP-9 production and conversion to its active form but also inhibiting IL-1β inhibition on TIMP-1 and TIMP-2 production. PMID:25237378

  18. Transparent amorphous oxide semiconductors for organic electronics: Application to inverted OLEDs

    PubMed Central

    Hosono, Hideo; Toda, Yoshitake; Kamiya, Toshio; Watanabe, Satoru

    2017-01-01

    Efficient electron transfer between a cathode and an active organic layer is one key to realizing high-performance organic devices, which require electron injection/transport materials with very low work functions. We developed two wide-bandgap amorphous (a-) oxide semiconductors, a-calcium aluminate electride (a-C12A7:e) and a-zinc silicate (a-ZSO). A-ZSO exhibits a low work function of 3.5 eV and high electron mobility of 1 cm2/(V · s); furthermore, it also forms an ohmic contact with not only conventional cathode materials but also anode materials. A-C12A7:e has an exceptionally low work function of 3.0 eV and is used to enhance the electron injection property from a-ZSO to an emission layer. The inverted electron-only and organic light-emitting diode (OLED) devices fabricated with these two materials exhibit excellent performance compared with the normal type with LiF/Al. This approach provides a solution to the problem of fabricating oxide thin-film transistor-driven OLEDs with both large size and high stability. PMID:28028243

  19. Probing matrix and tumor mechanics with in situ calibrated optical trap based active microrheology

    NASA Astrophysics Data System (ADS)

    Staunton, Jack Rory; Vieira, Wilfred; Tanner, Kandice; Tissue Morphodynamics Unit Team

    Aberrant extracellular matrix deposition and vascularization, concomitant with proliferation and phenotypic changes undergone by cancer cells, alter mechanical properties in the tumor microenvironment during cancer progression. Tumor mechanics conversely influence progression, and the identification of physical biomarkers promise improved diagnostic and prognostic power. Optical trap based active microrheology enables measurement of forces up to 0.5 mm within a sample, allowing interrogation of in vitro biomaterials, ex vivo tissue sections, and small organisms in vivo. We fabricated collagen I hydrogels exhibiting distinct structural properties by tuning polymerization temperature Tp, and measured their shear storage and loss moduli at frequencies 1-15k Hz at multiple amplitudes. Lower Tp gels, with larger pore size but thicker, longer fibers, were stiffer than higher Tp gels; decreasing strain increased loss moduli and decreased storage moduli at low frequencies. We subcutanously injected probes with metastatic murine melanoma cells into mice. The excised tumors displayed storage and loss moduli 40 Pa and 10 Pa at 1 Hz, increasing to 500 Pa and 1 kPa at 15 kHz, respectively.

  20. Design and feasibility of active matrix flat panel detector using avalanche amorphous selenium for protein crystallography.

    PubMed

    Sultana, Afrin; Reznik, Alla; Karim, Karim S; Rowlands, J A

    2008-10-01

    Protein crystallography is the most important technique for resolving the three-dimensional atomic structure of protein by measuring the intensity of its x-ray diffraction pattern. This work proposes a large area flat panel detector for protein crystallography based on direct conversion x-ray detection technique using avalanche amorphous selenium (a-Se) as the high gain photoconductor, and active matrix readout using amorphous silicon (a-Si:H) thin film transistors. The detector employs avalanche multiplication phenomenon of a-Se to make the detector sensitive to each incident x ray. The advantages of the proposed detector over the existing imaging plate and charge coupled device detectors are large area, high dynamic range coupled to single x-ray detection capability, fast readout, high spatial resolution, and inexpensive manufacturing process. The optimal detector design parameters (such as detector size, pixel size, and thickness of a-Se layer), and operating parameters (such as electric field across the a-Se layer) are determined based on the requirements for protein crystallography application. The performance of the detector is evaluated in terms of readout time (<1 s), dynamic range (approximately 10(5)), and sensitivity (approximately 1 x-ray photon), thus validating the detector's efficacy for protein crystallography.

  1. Full-order Mueller matrix polarimeter using liquid-crystal phase retarders and active illumination

    NASA Astrophysics Data System (ADS)

    Dayton, David C.; Hoover, Brian G.; Gonglewski, John D.

    2003-03-01

    Full order Stokes polarimeters are often composed of an analyzer consisting of a rotating quarter wave plate in front of a horizontal polarizer. A number of measurements are then made with the wave-plate oriented at different angle. The four-element Stokes vector is then computed from a linear combination of these measurements. A disadvantage of this device is that only a limited range of analyzer states can be generated. As a result a large number of measurements may be required to reduce the noise gain in the Stokes vector reconstructor. In this paper we describe a polarimeter based on a linear polarizer and two variable wave plates. It can be shown that such a device can produce an arbitrary polarization state. An active polarimeter consists of a generator stage, which transmits a laser illuminator with different polarization states and a receiver with a polarization analyzer stage. In our system both generator and analyzer stages consist of a horizontal polarizer and two variable wave-plates. A sixteen element Mueller matrix of resolved images is then formed for target characterization.

  2. Piezoelectric properties of the new generation active matrix hybrid (micro-nano) composites

    NASA Astrophysics Data System (ADS)

    Parali, Levent; Şabikoğlu, İsrafil; Kurbanov, Mirza A.

    2014-11-01

    A hybrid piezoelectric composite structure is obtained by addition of nano-sized BaTiO3, SiO2 to the micro-sized PZT and polymers composition. Although the PZT material itself has excellent piezoelectric properties, PZT-based composite variety is limited. Piezoelectric properties of PZT materials can be varied with an acceptor or a donor added to the material. In addition, varieties of PZT-based sensors can be increased with doping polymers which have physical-mechanical, electrophysical, thermophysical and photoelectrical properties. The active matrix hybrid structure occurs when bringing together the unique piezoelectric properties of micro-sized PZT with electron trapping properties of nano-sized insulators (BaTiO3 or SiO2), and their piezoelectric, mechanic and electromechanic properties significantly change. In this study, the relationship between the piezoelectric constant and the coupling factor values of microstructure (PZT-PVDF) and the hybrid structure (PZT-PVDF-BaTiO3) composite are compared. The d33 value and the coupling factor of the hybrid structure have shown an average of 54 and 62% increase according to microstructure composite, respectively. In addition, the d33 value and the coupling factor of the hybrid structure (PZT-HDPE-SiO2) have exhibited about 68 and 52% increase according to microstructure composite (PZT-HDPE), respectively.

  3. Ole e 13 is the unique food allergen in olive: Structure-functional, substrates docking, and molecular allergenicity comparative analysis.

    PubMed

    Jimenez-Lopez, J C; Robles-Bolivar, P; Lopez-Valverde, F J; Lima-Cabello, E; Kotchoni, S O; Alché, J D

    2016-05-01

    Thaumatin-like proteins (TLPs) are enzymes with important functions in pathogens defense and in the response to biotic and abiotic stresses. Last identified olive allergen (Ole e 13) is a TLP, which may also importantly contribute to food allergy and cross-allergenicity to pollen allergen proteins. The goals of this study are the characterization of the structural-functionality of Ole e 13 with a focus in its catalytic mechanism, and its molecular allergenicity by extensive analysis using different molecular computer-aided approaches covering a) functional-regulatory motifs, b) comparative study of linear sequence, 2-D and 3D structural homology modeling, c) molecular docking with two different β-D-glucans, d) conservational and evolutionary analysis, e) catalytic mechanism modeling, and f) IgE-binding, B- and T-cell epitopes identification and comparison to other allergenic TLPs. Sequence comparison, structure-based features, and phylogenetic analysis identified Ole e 13 as a thaumatin-like protein. 3D structural characterization revealed a conserved overall folding among plants TLPs, with mayor differences in the acidic (catalytic) cleft. Molecular docking analysis using two β-(1,3)-glucans allowed to identify fundamental residues involved in the endo-1,3-β-glucanase activity, and defining E84 as one of the conserved residues of the TLPs responsible of the nucleophilic attack to initiate the enzymatic reaction and D107 as proton donor, thus proposing a catalytic mechanism for Ole e 13. Identification of IgE-binding, B- and T-cell epitopes may help designing strategies to improve diagnosis and immunotherapy to food allergy and cross-allergenic pollen TLPs.

  4. EGF AND TGF-{alpha} motogenic activities are mediated by the EGF receptor via distinct matrix-dependent mechanisms

    SciTech Connect

    Ellis, Ian R.; Schor, Ana M.; Schor, Seth L. . E-mail: s.l.schor@dundee.ac.uk

    2007-02-15

    EGF and TGF-{alpha} induce an equipotent stimulation of fibroblast migration and proliferation. In spite of their homologous structure and ligation by the same receptor (EGFR), we report that their respective motogenic activities are mediated by different signal transduction intermediates, with p70{sup S6K} participating in EGF signalling and phospholipase C{gamma} in TGF-{alpha} signalling. We additionally demonstrate that EGF and TGF-{alpha} motogenic activities may be resolved into two stages: (a) cell 'activation' by a transient exposure to either cytokine, and (b) the subsequent 'manifestation' of an enhanced migratory phenotype in the absence of cytokine. The cell activation and manifestation stages for each cytokine are mediated by distinct matrix-dependent mechanisms: motogenetic activation by EGF requires the concomitant functionality of EGFR and the hyaluronan receptor CD44, whereas activation by TGF-{alpha} requires EGFR and integrin {alpha}v{beta}3. Manifestation of elevated migration no longer requires the continued presence of exogenous cytokine and functional EGFR but does require the above mentioned matrix receptors, as well as their respective ligands, i.e., hyaluronan in the case of EGF, and vitronectin in the case of TGF-{alpha}. In contrast, the mitogenic activities of EGF and TGF-{alpha} are independent of CD44 and {alpha}v{beta}3 functionality. These results demonstrate clear qualitative differences between EGF and TGF-{alpha} pathways and highlight the importance of the extracellular matrix in regulating cytokine bioactivity.

  5. Biosensing of matrix metalloproteinase activity with Cd-free quantum dots

    NASA Astrophysics Data System (ADS)

    Plumley, John Bryan

    Quantum dots (QDs) have become attractive in the biomedical field on account of their superior optical properties and stability, in comparison to traditional fluorophores. QDs also have properties which make them ideal for complex in vivo conditions. However, toxicity has been a chief concern in the eventual implementation of QDs for in vivo applications such as biosensing and tumor imaging. Commercially available QDs contain a notoriously noxious Cd component and therefore continuous research has gone into developing QDs without toxic heavy metals, generally Cd, that would still yield comparable performance in terms of their optical properties. Nonetheless, even in the case of Cd-free QDs, toxicity should be evaluated on a case by case basis, as other properties such as size, coating, stability, and charge can affect toxicity of nanomaterials as well, making it a very complex issue. With the high promise of QDs in the field of biomedical development as a motivation, this work strives to develop the efficient and repeatable synthesis of Cd-free QDs with high stability and luminescence, with proven low toxicity, and the ability to detect active matrix metalloproteinase (MMP) in a biosensing system, designed to identify direct biomarkers for pathological conditions, which in turn would enable early disease diagnosis and better treatment development. In this work, highly luminescent ZnSe:Mn/ZnS QDs have been synthesized, characterized, and modified with peptides with a bioconjugation procedure that utilized thiol-metal affinity. Experiments aiming at MMP detection were conducted using the peptide/QD conjugates. In addition, the ApoTox-Glo(TM) Triplex assay was utilized to evaluate cytotoxicity, and a safe concentration below 0.125 microM was identified for peptide-coated ZnSe:Mn/ZnS QDs in water. Finally, in contribution to developing an in vivo fiberoptic system for sensing MMP activity, the QDs were successfully tethered to silica and MMP detection was demonstrated

  6. Captopril and lisinopril only inhibit matrix metalloproteinase-2 (MMP-2) activity at millimolar concentrations.

    PubMed

    Kuntze, Luciana B; Antonio, Raquel C; Izidoro-Toledo, Tatiane C; Meschiari, Cesar A; Tanus-Santos, Jose E; Gerlach, Raquel F

    2014-03-01

    Matrix metalloproteinase-2 (MMP-2) shares structural similarities with the angiotensin-converting enzyme (ACE). ACE inhibitors have been described to inhibit MMP-2, but this inhibitory potential was not shown using a highly purified MMP-2. This study aimed to investigate the inhibitory potential of captopril and lisinopril regarding MMP-2 activity. The first objective was to test the potential of captopril to change the pH of the buffer solution. The second objective was to test the direct inhibitory effect of captopril and lisinopril on plasma MMP-2 and on recombinant human MMP-2 (rhMMP-2). The in vitro activity assays included gelatin zymography and a fluorimetric assay. Captopril solubilization significantly decreased the pH of the 50 mM Tris buffer solution at the following concentrations: 2 mM (p < 0.05), 4 mM and 8 mM (p < 0.01), while only the 8 mM lisinopril induced a drop in pH (p < 0.05). Thus, only 200 mM buffer solutions were used. Zymography results of plasma MMP-2 and rhMMP-2 showed that inhibition only happened at captopril concentrations ≥ 4 and 1 mM, respectively (p < 0.05), while only the higher concentration of lisinopril (8 mM) inhibited plasma MMP-2 (p < 0.05). In the fluorimetric assay, captopril led to significant inhibition of the rhMMP-2 activity at concentrations ≥2 mM (p < 0.01), whereas aminophenylmercuric acetate-activated rhMMP-2 was inhibited by 0.5 mM captopril (p < 0.01). The captopril and lisinopril concentrations found to inhibit MMP-2 are 3 orders of magnitude higher than those present in vivo after drug administration. We also discuss possible pitfalls for gelatinase inhibitory assays (besides the obvious pH problem already cited). In conclusion, this study's data show that captopril and lisinopril did not inhibit MMP-2 directly at the concentrations reached in vivo.

  7. Matrix Vesicle Enzyme Activity and Phospholipid Content in Endosteal Bone Following Implantation of Osseointegrating and Non-Osseointegrating Implant Materials.

    DTIC Science & Technology

    1992-01-01

    vesicles are an initial locus for calcification in most calcified matrices. b. The studies to be performed include: alkaline phosphatase specific activity...Treatment and Contralateral Tibias .............................. 23 Figure 6. Alkaline Phosphatase Specific Activity of Matrix Vesicle-Enriched Membranes...endosteal tissue removed from treated tibias, as well as the contralateral control. There was an increase at six days in MVEM alkaline phosphatase and

  8. Recent advances in AM OLED technologies for application to aerospace and military systems

    NASA Astrophysics Data System (ADS)

    Sarma, Kalluri R.; Roush, Jerry; Chanley, Charles

    2012-06-01

    While initial AM OLED products have been introduced in the market about a decade ago, truly successful commercialization of OLEDs has started only a couple of years ago, by Samsung Mobile Display (SMD), with small high performance displays for smart phone applications. This success by Samsung has catalyzed significant interest in AM OLED technology advancement and commercialization by other display manufacturers. Currently, significant manufacturing capacity for AM OLED displays is being established by the industry to serve the growing demand for these displays. The current development in the AM OLED industry are now focused on the development and commercialization of medium size (~10") AM OLED panels for Tablet PC applications and large size (~55") panels for TV applications. This significant progress in commercialization of AM OLED technology is enabled by major advances in various enabling technologies that include TFT backplanes, OLED materials and device structures and manufacturing know-how. In this paper we will discuss these recent advances, particularly as they relate to supporting high performance applications such as aerospace and military systems, and then discuss the results of the OLED testing for aerospace applications.

  9. MATERIALS DEGRADATION ANALYSIS AND DEVELOPMENT TO ENABLE ULTRA LOW COST, WEB-PROCESSED WHITE P-OLED FOR SSL

    SciTech Connect

    DR. DEVIN MACKENZIE

    2011-12-13

    Progress over Phase II of DE-FG02-07ER86293 'Materials Degradation Analysis and Development to Enable Ultra Low Cost, Web-Processed White P-OLED for SSL' was initially rapid in terms of device performance improvements. We exceeded our device luminance lifetime goals for printed flexible white OLEDs as laid out in our project proposal. Our Phase II performance target was to demonstrate >1500 hours luminance lifetime at 100 Cd/m2 from a printed flexible device. We now have R&D devices well in excess of 8000 hrs lifetime at 100 Cd/m2, tested in air. We also were able to produce devices which met the voltage target of >1500 hours below 15V operation. After completing the initial performance milestones, we went on to focus on color-related degradation issues which were cited as important to commercialization of the technology by our manufacturing partners. We also put additional focus on cathode work as the active material development that occurred over the STTR time period required an adaptation of the cathode from the original cathode formulations which were developed based on previous generation active layer materials. We were able to improve compatibility of the cathode with some of the newer generation active layer materials and improve device yield and voltage behavior. An additional objective of the initial Phase II was to further develop the underlying manufacturing technology and real-life product specifications. This is a key requirement that must be met to ensure eventual commercialization of this DOE-funded technology. The link between commercial investment for full commercialization and R&D efforts in OLED solid State Lighting is often a large one. Add-Vision's lower cost, printed OLED manufacturing approach is an attraction, but close engagement with manufacturing partners and addressing customer specifications is a very important link. Manufacturing technology encompasses development of moisture reduction encapsulation technology, improved cost

  10. The Role of Collagen Charge Clusters in the Modulation of Matrix Metalloproteinase Activity*

    PubMed Central

    Lauer, Janelle L.; Bhowmick, Manishabrata; Tokmina-Roszyk, Dorota; Lin, Yan; Van Doren, Steven R.; Fields, Gregg B.

    2014-01-01

    Members of the matrix metalloproteinase (MMP) family selectively cleave collagens in vivo. Several substrate structural features that direct MMP collagenolysis have been identified. The present study evaluated the role of charged residue clusters in the regulation of MMP collagenolysis. A series of 10 triple-helical peptide (THP) substrates were constructed in which either Lys-Gly-Asp or Gly-Asp-Lys motifs replaced Gly-Pro-Hyp (where Hyp is 4-hydroxy-l-proline) repeats. The stabilities of THPs containing the two different motifs were analyzed, and kinetic parameters for substrate hydrolysis by six MMPs were determined. A general trend for virtually all enzymes was that, as Gly-Asp-Lys motifs were moved from the extreme N and C termini to the interior next to the cleavage site sequence, kcat/Km values increased. Additionally, all Gly-Asp-Lys THPs were as good or better substrates than the parent THP in which Gly-Asp-Lys was not present. In turn, the Lys-Gly-Asp THPs were also always better substrates than the parent THP, but the magnitude of the difference was considerably less compared with the Gly-Asp-Lys series. Of the MMPs tested, MMP-2 and MMP-9 most greatly favored the presence of charged residues with preference for the Gly-Asp-Lys series. Lys-Gly-(Asp/Glu) motifs are more commonly found near potential MMP cleavage sites than Gly-(Asp/Glu)-Lys motifs. As Lys-Gly-Asp is not as favored by MMPs as Gly-Asp-Lys, the Lys-Gly-Asp motif appears advantageous over the Gly-Asp-Lys motif by preventing unwanted MMP hydrolysis. More specifically, the lack of Gly-Asp-Lys clusters may diminish potential MMP-2 and MMP-9 collagenolytic activity. The present study indicates that MMPs have interactions spanning the P23–P23′ subsites of collagenous substrates. PMID:24297171

  11. The role of collagen charge clusters in the modulation of matrix metalloproteinase activity.

    PubMed

    Lauer, Janelle L; Bhowmick, Manishabrata; Tokmina-Roszyk, Dorota; Lin, Yan; Van Doren, Steven R; Fields, Gregg B

    2014-01-24

    Members of the matrix metalloproteinase (MMP) family selectively cleave collagens in vivo. Several substrate structural features that direct MMP collagenolysis have been identified. The present study evaluated the role of charged residue clusters in the regulation of MMP collagenolysis. A series of 10 triple-helical peptide (THP) substrates were constructed in which either Lys-Gly-Asp or Gly-Asp-Lys motifs replaced Gly-Pro-Hyp (where Hyp is 4-hydroxy-L-proline) repeats. The stabilities of THPs containing the two different motifs were analyzed, and kinetic parameters for substrate hydrolysis by six MMPs were determined. A general trend for virtually all enzymes was that, as Gly-Asp-Lys motifs were moved from the extreme N and C termini to the interior next to the cleavage site sequence, kcat/Km values increased. Additionally, all Gly-Asp-Lys THPs were as good or better substrates than the parent THP in which Gly-Asp-Lys was not present. In turn, the Lys-Gly-Asp THPs were also always better substrates than the parent THP, but the magnitude of the difference was considerably less compared with the Gly-Asp-Lys series. Of the MMPs tested, MMP-2 and MMP-9 most greatly favored the presence of charged residues with preference for the Gly-Asp-Lys series. Lys-Gly-(Asp/Glu) motifs are more commonly found near potential MMP cleavage sites than Gly-(Asp/Glu)-Lys motifs. As Lys-Gly-Asp is not as favored by MMPs as Gly-Asp-Lys, the Lys-Gly-Asp motif appears advantageous over the Gly-Asp-Lys motif by preventing unwanted MMP hydrolysis. More specifically, the lack of Gly-Asp-Lys clusters may diminish potential MMP-2 and MMP-9 collagenolytic activity. The present study indicates that MMPs have interactions spanning the P23-P23' subsites of collagenous substrates.

  12. Extracellular matrix-specific focal adhesions in vascular smooth muscle produce mechanically active adhesion sites

    PubMed Central

    Sun, Zhe; Martinez-Lemus, Luis A.; Hill, Michael A.; Meininger, Gerald A.

    2008-01-01

    Integrin-mediated mechanotransduction in vascular smooth muscle cells (VSMCs) plays an important role in the physiological control of tissue blood flow and vascular resistance. To test whether force applied to specific extracellular matrix (ECM)-integrin interactions could induce myogenic-like mechanical activity at focal adhesion sites, we used atomic force microscopy (AFM) to apply controlled forces to specific ECM adhesion sites on arteriolar VSMCs. The tip of AFM probes were fused with a borosilicate bead (2∼5 μm) coated with fibronectin (FN), collagen type I (CNI), laminin (LN), or vitronectin (VN). ECM-coated beads induced clustering of α5- and β3-integrins and actin filaments at sites of bead-cell contact indicative of focal adhesion formation. Step increases of an upward (z-axis) pulling force (800∼1,600 pN) applied to the bead-cell contact site for FN-specific focal adhesions induced a myogenic-like, force-generating response from the VSMC, resulting in a counteracting downward pull by the cell. This micromechanical event was blocked by cytochalasin D but was enhanced by jasplakinolide. Function-blocking antibodies to α5β1- and αvβ3-integrins also blocked the micromechanical cell event in a concentration-dependent manner. Similar pulling experiments with CNI, VN, or LN failed to induce myogenic-like micromechanical events. Collectively, these results demonstrate that mechanical force applied to integrin-FN adhesion sites induces an actin-dependent, myogenic-like, micromechanical event. Focal adhesions formed by different ECM proteins exhibit different mechanical characteristics, and FN appears of particular relevance in its ability to strongly attach to VSMCs and to induce myogenic-like, force-generating reactions from sites of focal adhesion in response to externally applied forces. PMID:18495809

  13. Performance of a direct-detection active matrix flat panel dosimeter (AMFPD) for IMRT measurements.

    PubMed

    Chen, Yu; Moran, Jean M; Roberts, Donald A; El-Mohri, Youcef; Antonuk, Larry E; Fraass, Benedick A

    2007-12-01

    The dosimetric performance of a direct-detection active matrix flat panel dosimeter (AMFPD) is reported for intensity modulated radiation therapy (IMRT) measurements. The AMFPD consists of a-Si : H photodiodes and thin-film transistors deposited on a glass substrate with no overlying scintillator screen or metal plate. The device is operated at 0.8 frames per second in a continuous acquisition or fluoroscopic mode. The effect of the applied bias voltage across the photodiodes on the response of the AMFPD was evaluated because this parameter affects dark signal, lag contributions, and pixel sensitivity. In addition, the AMPFD response was evaluated as a function of dose, dose rate, and energy, for static fields at 10 cm depth. In continuous acquisition mode, the AMFPD maintained a linear dose response (r2 > 0.99999) up to at least 1040 cGy. In order to obtain reliable integrated dose results for IMRT fields, the effects of lag on the radiation signal were minimized by operating the system at the highest frame rate and at an appropriate reverse bias voltage. Segmental MLC and dynamic MLC IMRT fields were measured with the AMFPD, and the results were compared to film, using standard methods for reliable film dosimetry. Both AMFPD and film measurements were independently converted to dose in cGy. Gamma and chi values were calculated as indices of agreement. The results from the AMFPD were in excellent agreement with those from film. When 2% of D(max) and 2 mm of distance to agreement were used as the criteria, 98% of the region of interest (defined as the region where dose is greater than 5% of D(max)) satisfied [chi] < or = 1 on average across the cases that were tested.

  14. Relative dosimetry using active matrix flat-panel imager (AMFPI) technology.

    PubMed

    El-Mohri, Y; Antonuk, L E; Yorkston, J; Jee, K W; Maolinbay, M; Lam, K L; Siewerdsen, J H

    1999-08-01

    The first examination of the use of active matrix flat-panel arrays for dosimetry in radiotherapy is reported. Such arrays are under widespread development for diagnostic and radiotherapy imaging. In the current study, an array consisting of 512 x 512 pixels with a pixel pitch of 508 microm giving an area of 26 x 26 cm2 has been used. Each pixel consists of a light sensitive amorphous silicon (a-Si:H) photodiode coupled to an a-Si:H thin-film transistor. Data was obtained from the array using a dedicated electronics system allowing real-time data acquisition. In order to examine the potential of such arrays as quality assurance devices for radiotherapy beams, field profile data at photon energies of 6 and 15 MV were obtained as a function of field size and thickness of overlying absorbing material (solid water). Two detection configurations using the array were considered: a configuration (similar to the imaging configuration) in which an overlying phosphor screen is used to convert incident radiation to visible light photons which are detected by the photodiodes; and a configuration without the screen where radiation is directly sensed by the photodiodes. Compared to relative dosimetry data obtained with an ion chamber, data taken using the former configuration exhibited significant differences whereas data obtained using the latter configuration was generally found to be in close agreement. Basic signal properties, which are pertinent to dosimetry, have been investigated through measurements of individual pixel response for fluoroscopic and radiographic array operation. For signal levels acquired within the first 25% of pixel charge capacity, the degree of linear response with dose was found to be better than 99%. The independence of signal on dose rate was demonstrated by means of stability of pixel response over the range of dose rates allowed by the radiation source (80-400 MU/min). Finally, excellent long-term stability in pixel response, extending over a 2

  15. Proanthocyanidins from the American Cranberry (Vaccinium macrocarpon) inhibit matrix metalloproteinase-2 and matrix metalloproteinase-9 activity in human prostate cancer cells via alterations in multiple cellular signalling pathways.

    PubMed

    Déziel, Bob A; Patel, Kunal; Neto, Catherine; Gottschall-Pass, Katherine; Hurta, Robert A R

    2010-10-15

    Prostate cancer is one of the most common cancers in the Western world, and it is believed that an individual's diet affects his risk of developing cancer. There has been an interest in examining phytochemicals, the secondary metabolites of plants, in order to determine their potential anti-cancer activities in vitro and in vivo. In this study we document the effects of proanthocyanidins (PACs) from the American Cranberry (Vaccinium macrocarpon) on matrix metalloproteinase (MMP) activity in DU145 human prostate cancer cells. Cranberry PACs decreased cellular viability of DU145 cells at a concentration of 25 µg/ml by 30% after 6 h of treatment. Treatment of DU145 cells with PACs resulted in an inhibition of both MMPs 2 and 9 activity. PACs increased the expression of TIMP-2, a known inhibitor of MMP activity, and decreased the expression of EMMPRIN, an inducer of MMP expression. PACs decreased the expression of PI-3 kinase and AKT proteins, and increased the phosphorylation of both p38 and ERK1/2. Cranberry PACs also decreased the translocation of the NF-κB p65 protein to the nucleus. Cranberry PACs increased c-jun and decreased c-fos protein levels. These results suggest that cranberry PACs decreases MMP activity through the induction and/or inhibition of specific temporal MMP regulators, and by affecting either the phosphorylation status and/or expression of MAP kinase, PI-3 kinase, NF-κB and AP-1 pathway proteins. This study further demonstrates that cranberry PACs are a strong candidate for further research as novel anti-cancer agents.

  16. 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

  17. Food matrix and processing influence on carotenoid bioaccessibility and lipophilic antioxidant activity of fruit juice-based beverages.

    PubMed

    Rodríguez-Roque, María Janeth; de Ancos, Begoña; Sánchez-Vega, Rogelio; Sánchez-Moreno, Concepción; Cano, M Pilar; Elez-Martínez, Pedro; Martín-Belloso, Olga

    2016-01-01

    The biological activity of carotenoids depends on their bioaccessibility and solubilization in the gastrointestinal tract. These compounds are poorly dispersed in the aqueous media of the digestive tract due to their lipophilic nature. Thus, it is important to analyze the extent to which some factors, such as the food matrix and food processing, may improve their bioaccessibility. Beverages formulated with a blend of fruit juices and water (WB), milk (MB) or soymilk (SB) were treated by high-intensity pulsed electric fields (HIPEF) (35 kV cm(-1) with 4 μs bipolar pulses at 200 Hz for 1800 μs), high-pressure processing (HPP) (400 MPa at 40 °C for 5 min) or thermal treatment (TT) (90 °C for 1 min) in order to evaluate the influence of food matrix and processing on the bioaccessibility of carotenoids and on the lipophilic antioxidant activity (LAA). The bioaccessibility of these compounds diminished after applying any treatment (HIPEF, HPP and TT), with the exception of cis-violaxanthin + neoxanthin, which increased by 79% in HIPEF and HPP beverages. The lowest carotenoid bioaccessibility was always obtained in TT beverages (losses up to 63%). MB was the best food matrix for improving the bioaccessibility of carotenoids, as well as the LAA. The results demonstrate that treatment and food matrix modulated the bioaccessibility of carotenoids as well as the lipophilic antioxidant potential of beverages. Additionally, HIPEF and HPP could be considered as promising technologies to obtain highly nutritional and functional beverages.

  18. Trimer Enhancement Mutation Effects on HIV-1 Matrix Protein Binding Activities

    PubMed Central

    Alfadhli, Ayna; Mack, Andrew; Ritchie, Christopher; Cylinder, Isabel; Harper, Logan; Tedbury, Philip R.; Freed, Eric O.

    2016-01-01

    ABSTRACT The HIV-1 matrix (MA) protein is the amino-terminal domain of the HIV-1 precursor Gag (Pr55Gag) protein. MA binds to membranes and RNAs, helps transport Pr55Gag proteins to virus assembly sites at the plasma membranes of infected cells, and facilitates the incorporation of HIV-1 envelope (Env) proteins into virions by virtue of an interaction with the Env protein cytoplasmic tails (CTs). MA has been shown to crystallize as a trimer and to organize on membranes in hexamer lattices. MA mutations that localize to residues near the ends of trimer spokes have been observed to impair Env protein assembly into virus particles, and several of these are suppressed by the 62QR mutation at the hubs of trimer interfaces. We have examined the binding activities of wild-type (WT) MA and 62QR MA variants and found that the 62QR mutation stabilized MA trimers but did not alter the way MA proteins organized on membranes. Relative to WT MA, the 62QR protein showed small effects on membrane and RNA binding. However, 62QR proteins bound significantly better to Env CTs than their WT counterparts, and CT binding efficiencies correlated with trimerization efficiencies. Our data suggest a model in which multivalent binding of trimeric HIV-1 Env proteins to MA trimers contributes to the process of Env virion incorporation. IMPORTANCE The HIV-1 Env proteins assemble as trimers, and incorporation of the proteins into virus particles requires an interaction of Env CT domains with the MA domains of the viral precursor Gag proteins. Despite this knowledge, little is known about the mechanisms by which MA facilitates the virion incorporation of Env proteins. To help elucidate this process, we examined the binding activities of an MA mutant that stabilizes MA trimers. We found that the mutant proteins organized similarly to WT proteins on membranes, and that mutant and WT proteins revealed only slight differences in their binding to RNAs or lipids. However, the mutant proteins showed

  19. Tris-(8-hydroxyquinoline)aluminum thin film as ETL in efficient green phosphorescent OLEDs

    NASA Astrophysics Data System (ADS)

    Thangaraju, K.; Kim, Yun-Hi; Kwon, Soon-Ki

    2013-02-01

    Tris-(8-hydroxyquinoline)aluminum thin film as ETL in green phosphorescent OLEDs improves the device performances to a maximum of 34.2 cd/A, 11.3% with the maximum brightness of 63,150 cd/m2 and broadens the device emission in yellow-green region suitable in the white OLEDs for the lighting applications.

  20. Novel carbazole/fluorene hybrids: host materials for blue phosphorescent OLEDs.

    PubMed

    Shih, Ping-I; Chiang, Chih-Long; Dixit, Ajay Kumar; Chen, Ching-Kun; Yuan, Mao-Chuan; Lee, Rei-Yuen; Chen, Chin-Ti; Diau, Eric Wei-Guang; Shu, Ching-Fong

    2006-06-22

    [reaction: see text] A series of carbazole/fluorene (CBZm-Fn) hybrids were effectively synthesized through Friedel-Crafts-type substitution of the carbazole rings. These compounds were thermally and morphologically stable host materials for OLED applications. Efficient blue phosphorescent OLEDs were obtained when employing CBZ1-F2 as the host and FIrpic as the guest.

  1. Stacked white OLED having separate red, green and blue sub-elements

    DOEpatents

    Forrest, Stephen; Qi, Xiangfei; Slootsky, Michael

    2015-06-23

    The present invention relates to efficient organic light emitting devices (OLEDs). More specifically, the present invention relates to white-emitting OLEDs, or WOLEDs. The devices of the present invention employ three emissive sub-elements, typically emitting red, green and blue, to sufficiently cover the visible spectrum. The sub-elements are separated by charge generating layers.

  2. Stacked white OLED having separate red, green and blue sub-elements

    SciTech Connect

    Forrest, Stephen; Qi, Xiangfei; Slootsky, Michael

    2016-06-28

    The present invention relates to efficient organic light emitting devices (OLEDs). More specifically, the present invention relates to white-emitting OLEDs, or WOLEDs. The devices of the present invention employ three emissive sub-elements, typically emitting red, green and blue, to sufficiently cover the visible spectrum. The sub-elements are separated by charge generating layers.

  3. Gelatinolytic activity of matrix metalloproteinase-2 and matrix metalloproteinase-9 in rat brain after implantation of 9L rat glioma cells.

    PubMed

    Zhao, J X; Yang, L P; Wang, Y F; Qin, L P; Liu, D Q; Bai, C X; Nan, X; Shi, S S; Pei, X J

    2007-05-01

    The matrix metalloproteinases (MMPs) have come to be highlighted by their close relation to the cell invasion of gliomas. The inhibitors of MMPs have undergone extensive development because of its effectiveness against tumor invasion and angiogenesis. Therefore, a suitable animal model is necessary for searching new MMPs inhibitors against gliomas. In this study, we established an experimental model by implanting 9L glioma cells stereotactically into Fisher344 (F344) rat's brain, and the expression and enzymatic activity of MMP-2 and MMP-9 in 9L glioma cells and in tumor tissue was determined by means of reverse transcription polymerase chain reaction (RT-PCR), sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) zymography, in situ film zymography and immunostaining. The results of RT-PCR showed that the mRNA level of MMP-2 in 9L glioma cells was higher than that of MMP-9, and the mRNA expression of MMP-9 was increased along with the growth of malignant gliomas. SDS-PAGE zymography revealed that the expression of MMP-2 and MMP-9 were significantly increased in tumor tissues, and the MMP-9 wasn't detected in normal tissue. The positive stain of MMP-2 and MMP-9 was enhanced with the growth of malignant gliomas, especially for MMP-9. The expression of active gelatinase was found in tumor tissue. In conclusion, the expression of active MMP-2 and MMP-9 was increased in 9L/F344 rat brain during the growth of malignant gliomas at different time intervals, which indicate that 9L/F344 animal model may be a prospective animal model to test new MMPs inhibitors.

  4. Molybdenum metallization, and step-induced defects in active-matrix liquid crystal displays

    NASA Astrophysics Data System (ADS)

    Quli, Farhat Abbas

    The objective of this work was to identify the causes of the step-induced preferential etching which occurs during the patterning of molybdenum (Mo) interconnects for the source/drain line metallization of the thin-film transistor array of active matrix liquid crystal displays. The morphology of Mo films deposited on steps under various conditions using sputtering and electron beam physical vapor deposition (EB-PVD) was studied to identify the causes of preferential etching, and determine processing conditions leading to defect-free interconnects. It was found that columnar growth domains grown from the steps were misaligned with the columnar growth from the substrate, causing the creation of high-angle grain boundaries where the columns impinged upon one another. This boundary region is believed to be responsible for the preferential etching in the Mo films. Columnar growth of silicon dioxide, an amorphous film, did not result in preferential etching due to the lack of grain boundaries. Neon (Ne) sputtering of Mo did not lead to amorphous films due to higher film bombardment during Ne sputtering, as reported by other researchers. Instead, the low rate of deposition during Ne sputtering was found to cause the incorporation of high amounts of impurities that lead to amorphization of the growing film. At extremely low rates and high impurity concentrations, it was found that the film grew in a fcc rather than bcc structure. Mo deposited under high levels of argon ion bombardment was found to have an isotropic rather than columnar morphology which led to interconnects that were free from preferential etching. The maximum ratio of depositing atoms to bombarding ions necessary to modify the microstructure was found to be 1.5 for Mo deposited by EB-PVD at 400°C substrate temperature and --600 volts substrate bias. The processing window for bias sputtering conditions leading to an isotropic morphology was also identified. Thermally induced grain growth in metal films was

  5. X-RAY ACTIVE MATRIX PIXEL SENSORS BASEDON J-FET TECHNOLOGY DEVELOPED FOR THE LINAC COHERENT LIGHT SOURCE.

    SciTech Connect

    CARINI,G.A.; CHEN, W.; LI, Z.; REHAK, P.; SIDDONS, D.P.

    2007-10-29

    An X-ray Active Matrix Pixel Sensor (XAMPS) is being developed for recording data for the X-ray Pump Probe experiment at the Linac Coherent Light Source (LCLS). Special attention has to be paid to some technological challenges that this design presents. New processes were developed and refined to address problems encountered during previous productions of XAMPS. The development of these critical steps and corresponding tests results are reported here.

  6. Planarization coating for polyimide substrates used in roll-to-roll fabrication of active matrix backplanes for flexible displays

    NASA Astrophysics Data System (ADS)

    Almanza-Workman, A. Marcia; Jeans, Albert; Braymen, Steve; Elder, Richard E.; Garcia, Robert A.; de la Fuente Vornbrock, Alejandro; Hauschildt, Jason; Holland, Edward; Jackson, Warren; Jam, Mehrban; Jeffrey, Frank; Junge, Kelly; Kim, Han-Jun; Kwon, Ohseung; Larson, Don; Luo, Hao; Maltabes, John; Mei, Ping; Perlov, Craig; Smith, Mark; Stieler, Dan; Taussig, Carl P.; Trovinger, Steve; Zhao, Lihua

    2012-03-01

    Good surface quality of plastic substrates is essential to reduce pixel defects during roll-to-roll fabrication of flexible display active matrix backplanes. Standard polyimide substrates have a high density of "bumps" from fillers and belt marks and other defects from dust and surface scratching. Some of these defects could be the source of shunts in dielectrics. The gate dielectric must prevent shorts between the source/drain and the gate in the transistors, resist shorts in the hold capacitor and stop shorts in the data/gate line crossovers in active matrix backplanes fabricated by self-aligned imprint lithography (SAIL) roll-to-roll processes. Otherwise data and gate lines will become shorted creating line or pixel defects. In this paper, we discuss the development of a proprietary UV curable planarization material that can be coated by roll-to-roll processes. This material was engineered to have low shrinkage, excellent adhesion to polyimide, high dry etch resistance, and great chemical and thermal stability. Results from PECVD deposition of an amorphous silicon stack on the planarized polyimide and compatibility with roll-to-roll processes to fabricate active matrix backplanes are also discussed. The effect of the planarization on defects in the stack, shunts in the dielectric and curvature of finished arrays will also be described.

  7. Digital radiology using active matrix readout of amorphous selenium: radiation hardness of cadmium selenide thin film transistors.

    PubMed

    Zhao, W; Waechter, D; Rowlands, J A

    1998-04-01

    A flat-panel x-ray imaging detector using active matrix readout of amorphous selenium (a-Se) is being investigated for digital radiography and fluoroscopy. The active matrix consists of a two-dimensional array of thin film transistors (TFTs). Radiation penetrating through the a-Se layer will interact with the TFTs and it is important to ensure that radiation induced changes will not affect the operation of the x-ray imaging detector. The methodology of the present work is to investigate the effects of radiation on the characteristic curves of the TFTs using individual TFT samples made with cadmium selenide (CdSe) semiconductor. Four characteristic parameters, i.e., threshold voltage, subthreshold swing, field effect mobility, and leakage current, were examined. This choice of parameters was based on the well established radiation damage mechanisms for crystalline silicon metal-oxide-semiconductor field-effect transistors (MOSFETs), which have a similar principle of operation as CdSe TFTs. It was found that radiation had no measurable effect on the leakage current and the field effect mobility. However, radiation shifted the threshold voltage and increased the subthreshold swing. But even the estimated lifetime dose (50 Gy) of a diagnostic radiation detector will not affect the normal operation of an active matrix x-ray detector made with CdSe TFTs. The mechanisms of the effects of radiation will be discussed and compared with those for MOSFETs and hydrogenated amorphous silicon (a-Si:H) TFTs.

  8. Light diffusing effects of nano and micro-structures on OLED with microcavity.

    PubMed

    Cho, Doo-Hee; Shin, Jin-Wook; Joo, Chul Woong; Lee, Jonghee; Park, Seung Koo; Moon, Jaehyun; Cho, Nam Sung; Chu, Hye Yong; Lee, Jeong-Ik

    2014-10-20

    We examined the light diffusing effects of nano and micro-structures on microcavity designed OLEDs. The results of FDTD simulations and experiments showed that the pillar shaped nano-structure was more effective than the concave micro-structure for light diffusing of microcavity OLEDs. The sharp luminance distribution of the microcavity OLED was changed to near Lambertian luminance distribution by the nano-structure, and light diffusing effects increased with the height of the nano-structure. Furthermore, the nano-structure has advantages including light extraction of the substrate mode, reproducibility of manufacturing process, and minimizing pixel blur problems in an OLED display panel. The nano-structure is a promising candidate for a light diffuser, resolving the viewing angle problems in microcavity OLEDs.

  9. Near independence of OLED operating voltage on transport layer thickness

    SciTech Connect

    Swensen, James S.; Wang, Liang; Polikarpov, Evgueni; Rainbolt, James E.; Koech, Phillip K.; Cosimbescu, Lelia; Padmaperuma, Asanga B.

    2013-01-01

    We report organic light emitting devices (OLEDs) with weak drive voltage dependence on the thickness of the hole transport layer (HTL) for thicknesses up to 1150 Å using the N,N'-Bis(naphthalen-1-yl)-N,N'-bis(phenyl)-benzidine (α-NPD) and N,N'-bis(3-methyl phenyl)-N,N'-diphenyl-[1,1'-biphenyl]-4,4'diamine (TPD), both of which have hole mobilities in the range of 2 × 10-3 cm2V-1s-1. Lower mobility HTL materials show larger operating voltage dependence on thickness. The near independence of the operating voltage for high mobility transport material thickness was only observed when the energy barrier for charge injection into the transport material was minimized. To ensure low injection barriers, a thin film of 2-(3-(adamantan-1-yl)propyl)-3,5,6-trifluorotetracyanoquinodimethane (F3TCNQ-Adl) was cast from solution onto the ITO surface. These results indicate that thick transport layers can be integrated into OLED stacks without the need for bulk conductivity doping.

  10. Aryl Hydrocarbon Receptor Activation by TCDD Modulates Expression of Extracellular Matrix Remodeling Genes during Experimental Liver Fibrosis

    PubMed Central

    Lamb, Cheri L.; Cholico, Giovan N.; Perkins, Daniel E.; Fewkes, Michael T.; Oxford, Julia Thom; Lujan, Trevor J.; Morrill, Erica E.

    2016-01-01

    The aryl hydrocarbon receptor (AhR) is a soluble, ligand-activated transcription factor that mediates the toxicity of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Increasing evidence implicates the AhR in regulating extracellular matrix (ECM) homeostasis. We recently reported that TCDD increased necroinflammation and myofibroblast activation during liver injury elicited by carbon tetrachloride (CCl4). However, TCDD did not increase collagen deposition or exacerbate fibrosis in CCl4-treated mice, which raises the possibility that TCDD may enhance ECM turnover. The goal of this study was to determine how TCDD impacts ECM remodeling gene expression in the liver. Male C57BL/6 mice were treated for 8 weeks with 0.5 mL/kg CCl4, and TCDD (20 μg/kg) was administered during the last two weeks. Results indicate that TCDD increased mRNA levels of procollagen types I, III, IV, and VI and the collagen processing molecules HSP47 and lysyl oxidase. TCDD also increased gelatinase activity and mRNA levels of matrix metalloproteinase- (MMP-) 3, MMP-8, MMP-9, and MMP-13. Furthermore, TCDD modulated expression of genes in the plasminogen activator/plasmin system, which regulates MMP activation, and it also increased TIMP1 gene expression. These findings support the notion that AhR activation by TCDD dysregulates ECM remodeling gene expression and may facilitate ECM metabolism despite increased liver injury. PMID:27672655

  11. Relationship between activation volume and polymer matrix effects on photochromic performance: bridging molecular parameter to macroscale effect.

    PubMed

    Shima, Kentaro; Mutoh, Katsuya; Kobayashi, Yoichi; Abe, Jiro

    2015-02-19

    Photochromic compounds have attracted attention as ophthalmic lenses because of their reversible color modulation upon irradiation with light. However, the efficiency of the photochromism is strongly affected by their surrounding because of the structural changes concomitant with the photochromism, which causes the decrease in the photochromic performance in the polymer matrix. Therefore, the clarification of the degree of the structural changes is necessary to apply to the ophthalmic lenses. Bridged imidazole dimers are one of the fast photoswitch molecules possessing high photochromic quantum yield and durability. Although the enhancement of the photochromic properties of bridged imidazole dimers has been vigorously studied, the quantitative information about the structural changes has not been revealed in detail. In this study, we investigated the pressure effects on the photochromic properties of bridged imidazole dimers. The activation volume for the thermal back-reaction of the photogenerated biradical species becomes an effective measure to predict the degree of the structural change during the photochromic reaction. We revealed that the smaller activation volume is suitable for keeping the efficient photochromic reaction in the polymer matrix because the photochromic reaction is not affected by the surroundings. These fundamental insights into the molecular dynamics provide valuable information to develop fast photochromic compounds that are suitable for the use in the polymer matrix and pressure sensitive photochromic materials.

  12. Ciglitazone ameliorates homocysteine-mediated mitochondrial translocation and matrix metalloproteinase-9 activation in endothelial cells by inducing peroxisome proliferator activated receptor-gamma activity.

    PubMed

    Tyagi, N; Moshal, K S; Sen, U; Lominadze, D; Ovechkin, A V; Tyagi, S C

    2006-12-31

    The activation of peroxisome proliferator activated receptor-gamma (PPARgamma) ameliorates the homocysteine (Hcy)-induced matrix metalloproteinase (MMP) by decreasing reactive oxygen species (ROS) production. However, the mechanism by which Hcy induces ROS generation and MMP activation is unclear. We hypothesize that Hcy increases NADH oxidase (Nox-4) and decreases thioredoxin (Trx). This leads to translocation of Nox-4 into the mitochondria and decrease in Trx. In addition, activation of PPARgamma ameliorates the translocation of Nox-4 into mitochondria and MMP-9 activation. Mouse aortic vascular endothelial cells (MVEC) were cultured in the presence or absence of 100 microM Hcy. The cells were pre-treated with ciglitazone (CZ, 150 microM). Activity of PPARgamma activity was measured by electrophoretic mobility shift assay (EMSA) and antibody super shift assay. In situ generation of ROS was measured using 2,7-dichlorofluorescin (DCF) as a probe. The expression of Nox-4 and Trx were measured by quantitative real-time polymerase chain reaction (Q-RT-PCR). The translocation of Nox-4 was measured by 2-D gel analysis. To determine the levels of Nox-4 and Trx, the mitochondria and cytosol were separated and Western blot analysis was preformed. The MMP-9 activity was measured by gelatin-zymography. The results suggested that CZ activated endothelial PPARgamma in the presence of Hcy. Production of ROS was ameliorated by PPARgamma activation. Expression of Nox-4 was increased, while production of Trx was decreased by Hcy. However, the treatment with CZ normalized the levels of Nox-4 and Trx. Nox-4 was translocated into mitochondria in Hcy-treated endothelial cells. This translocation was associated with decreased production of Trx in mitochondria. The treatment with CZ blocked this translocation and increased Trx levels in mitochondria. Hcy-mediated MMP-9 activity was decreased in cells pre-treated with CZ. These results suggest that Hcy increases NADH oxidase and

  13. Wild-type amyloid beta 1-40 peptide induces vascular smooth muscle cell death independently from matrix metalloprotease activity.

    PubMed

    Blaise, Régis; Mateo, Véronique; Rouxel, Clotilde; Zaccarini, François; Glorian, Martine; Béréziat, Gilbert; Golubkov, Vladislav S; Limon, Isabelle

    2012-06-01

    Cerebral amyloid angiopathy (CAA) is an important cause of intracerebral hemorrhages in the elderly, characterized by amyloid-β (Aβ) peptide accumulating in central nervous system blood vessels. Within the vessel walls, Aβ-peptide deposits [composed mainly of wild-type (WT) Aβ(1-40) peptide in sporadic forms] induce impaired adhesion of vascular smooth muscle cells (VSMCs) to the extracellular matrix (ECM) associated with their degeneration. This process often results in a loss of blood vessel wall integrity and ultimately translates into cerebral ischemia and microhemorrhages, both clinical features of CAA. In this study, we decipher the molecular mechanism of matrix metalloprotease (MMP)-2 activation in WT-Aβ(1-40) -treated VSMC and provide evidence that MMP activity, although playing a critical role in cell detachment disrupting ECM components, is not involved in the WT-Aβ(1-40) -induced degeneration of VSMCs. Indeed, whereas this peptide clearly induced VSMC apoptosis, neither preventing MMP-2 activity nor hampering the expression of membrane type1-MMP, or preventing tissue inhibitors of MMPs-2 (TIMP-2) recruitment (two proteins evidenced here as involved in MMP-2 activation), reduced the number of dead cells. Even the use of broad-range MMP inhibitors (GM6001 and Batimastat) did not affect WT-Aβ(1-40) -induced cell apoptosis. Our results, in contrast to those obtained using the Aβ(1-40) Dutch variant suggesting a link between MMP-2 activity, VSMC mortality and degradation of specific matrix components, indicate that the ontogenesis of the Dutch familial and sporadic forms of CAAs is different. ECM degradation and VSMC degeneration would be tightly connected in the Dutch familial form while being two independent processes in sporadic forms of CAA.

  14. Platelet hyaluronidase-2: an enzyme that translocates to the surface upon activation to function in extracellular matrix degradation

    PubMed Central

    Albeiroti, Sami; Ayasoufi, Katayoun; Hill, David R.; Shen, Bo

    2015-01-01

    Following injury, platelets rapidly interact with the exposed extracellular matrix (ECM) of the vessel wall and the surrounding tissues. Hyaluronan (HA) is a major glycosaminoglycan component of the ECM and plays a significant role in regulating inflammation. We have recently reported that human platelets degrade HA from the surfaces of activated endothelial cells into fragments capable of inducing immune responses by monocytes. We also showed that human platelets contain the enzyme hyaluronidase-2 (HYAL2), one of two major hyaluronidases that digest HA in somatic tissues. The deposition of HA increases in inflamed tissues in several inflammatory diseases, including inflammatory bowel disease (IBD). We therefore wanted to define the mechanism by which platelets degrade HA in the inflamed tissues. In this study, we show that human platelets degrade the proinflammatory matrix HA through the activity of HYAL2 and that platelet activation causes the immediate translocation of HYAL2 from a distinct population of α-granules to platelet surfaces where it exerts its catalytic activity. Finally, we show that patients with IBD have lower platelet HYAL2 levels and activity than healthy controls. PMID:25411425

  15. How, with whom and when: an overview of CD147-mediated regulatory networks influencing matrix metalloproteinase activity

    PubMed Central

    Grass, G. Daniel; Toole, Bryan P.

    2015-01-01

    Matrix metalloproteinases (MMPs) comprise a family of 23 zinc-dependent enzymes involved in various pathologic and physiologic processes. In cancer, MMPs contribute to processes from tumour initiation to establishment of distant metastases. Complex signalling and protein transport networks regulate MMP synthesis, cell surface presentation and release. Earlier attempts to disrupt MMP activity in patients have proven to be intolerable and with underwhelming clinical efficacy; thus targeting ancillary proteins that regulate MMP activity may be a useful therapeutic approach. Extracellular matrix metalloproteinase inducer (EMMPRIN) was originally characterized as a factor present on lung cancer cells, which stimulated collagenase (MMP-1) production in fibroblasts. Subsequent studies demonstrated that EMMPRIN was identical with several other protein factors, including basigin (Bsg), all of which are now commonly termed CD147. CD147 modulates the synthesis and activity of soluble and membrane-bound [membrane-type MMPs (MT-MMPs)] in various contexts via homophilic/heterophilic cell interactions, vesicular shedding or cell-autonomous processes. CD147 also participates in inflammation, nutrient and drug transporter activity, microbial pathology and developmental processes. Despite the hundreds of manuscripts demonstrating CD147-mediated MMP regulation, the molecular underpinnings governing this process have not been fully elucidated. The present review summarizes our present knowledge of the complex regulatory systems influencing CD147 biology and provides a framework to understand how CD147 may influence MMP activity. PMID:26604323

  16. How, with whom and when: an overview of CD147-mediated regulatory networks influencing matrix metalloproteinase activity.

    PubMed

    Grass, G Daniel; Toole, Bryan P

    2015-11-24

    Matrix metalloproteinases (MMPs) comprise a family of 23 zinc-dependent enzymes involved in various pathologic and physiologic processes. In cancer, MMPs contribute to processes from tumour initiation to establishment of distant metastases. Complex signalling and protein transport networks regulate MMP synthesis, cell surface presentation and release. Earlier attempts to disrupt MMP activity in patients have proven to be intolerable and with underwhelming clinical efficacy; thus targeting ancillary proteins that regulate MMP activity may be a useful therapeutic approach. Extracellular matrix metalloproteinase inducer (EMMPRIN) was originally characterized as a factor present on lung cancer cells, which stimulated collagenase (MMP-1) production in fibroblasts. Subsequent studies demonstrated that EMMPRIN was identical with several other protein factors, including basigin (Bsg), all of which are now commonly termed CD147. CD147 modulates the synthesis and activity of soluble and membrane-bound [membrane-type MMPs (MT-MMPs)] in various contexts via homophilic/heterophilic cell interactions, vesicular shedding or cell-autonomous processes. CD147 also participates in inflammation, nutrient and drug transporter activity, microbial pathology and developmental processes. Despite the hundreds of manuscripts demonstrating CD147-mediated MMP regulation, the molecular underpinnings governing this process have not been fully elucidated. The present review summarizes our present knowledge of the complex regulatory systems influencing CD147 biology and provides a framework to understand how CD147 may influence MMP activity.

  17. Platelet hyaluronidase-2: an enzyme that translocates to the surface upon activation to function in extracellular matrix degradation.

    PubMed

    Albeiroti, Sami; Ayasoufi, Katayoun; Hill, David R; Shen, Bo; de la Motte, Carol A

    2015-02-26

    Following injury, platelets rapidly interact with the exposed extracellular matrix (ECM) of the vessel wall and the surrounding tissues. Hyaluronan (HA) is a major glycosaminoglycan component of the ECM and plays a significant role in regulating inflammation. We have recently reported that human platelets degrade HA from the surfaces of activated endothelial cells into fragments capable of inducing immune responses by monocytes. We also showed that human platelets contain the enzyme hyaluronidase-2 (HYAL2), one of two major hyaluronidases that digest HA in somatic tissues. The deposition of HA increases in inflamed tissues in several inflammatory diseases, including inflammatory bowel disease (IBD). We therefore wanted to define the mechanism by which platelets degrade HA in the inflamed tissues. In this study, we show that human platelets degrade the proinflammatory matrix HA through the activity of HYAL2 and that platelet activation causes the immediate translocation of HYAL2 from a distinct population of α-granules to platelet surfaces where it exerts its catalytic activity. Finally, we show that patients with IBD have lower platelet HYAL2 levels and activity than healthy controls.

  18. Biochemical and toxicological evaluation of nano-heparins in cell functional properties, proteasome activation and expression of key matrix molecules.

    PubMed

    Piperigkou, Zoi; Karamanou, Konstantina; Afratis, Nikolaos A; Bouris, Panagiotis; Gialeli, Chrysostomi; Belmiro, Celso L R; Pavão, Mauro S G; Vynios, Dimitrios H; Tsatsakis, Aristidis M

    2016-01-05

    The glycosaminoglycan heparin and its derivatives act strongly on blood coagulation, controlling the activity of serine protease inhibitors in plasma. Nonetheless, there is accumulating evidence highlighting different anticancer activities of these molecules in numerous types of cancer. Nano-heparins may have great biological significance since they can inhibit cell proliferation and invasion as well as inhibiting proteasome activation. Moreover, they can cause alterations in the expression of major modulators of the tumor microenvironment, regulating cancer cell behavior. In the present study, we evaluated the effects of two nano-heparin formulations: one isolated from porcine intestine and the other from the sea squirt Styela plicata, on a breast cancer cell model. We determined whether these nano-heparins are able to affect cell proliferation, apoptosis and invasion, as well as proteasome activity and the expression of extracellular matrix molecules. Specifically, we observed that nano-Styela compared to nano-Mammalian analogue has higher inhibitory role on cell proliferation, invasion and proteasome activity. Moreover, nano-Styela regulates cell apoptosis, expression of inflammatory molecules, such as IL-6 and IL-8 and reduces the expression levels of extracellular matrix macromolecules, such as the proteolytic enzymes MT1-MMP, uPA and the cell surface proteoglycans syndecan-1 and -2, but not on syndecan-4. The observations reported in the present article indicate that nano-heparins and especially ascidian heparin are effective agents for heparin-induced effects in critical cancer cell functions, providing an important possibility in pharmacological targeting.

  19. Degradation of HTL layers during device operation in PhOLEDs

    NASA Astrophysics Data System (ADS)

    Sivasubramaniam, Varatharajan; Brodkorb, Florian; Hanning, Stephanie; Buttler, Oliver; Loebl, Hans Peter; van Elsbergen, Volker; Boerner, Herbert; Scherf, Ullrich; Kreyenschmidt, Martin

    2009-11-01

    Different analytical tools and methodologies are currently employed to determine degradation products of organic blue light emitting devices in order to identify the failure mechanisms which determine the lifetime of these devices. This article provides a deeper understanding of degradation mechanisms of organic light emitting diodes (OLEDs) during device operation. Degradation products of blue emitting devices containing 8% of the phosphorescent emitter iridium(III)bis(4,6-difluorophenyl)-pyridinato-N,C 2' picolinate (FIrpic) in a matrix containing bis(2-methyl-8-quinolinolato)(4-phenylphenolato)aluminium (BAlq) as electron transport layer (ETL), 4,4',4″-tri( N-carbazolyl)triphenylamine (TCTA) and N, N'-diphenyl- N, N'-bis(1-naphthyl)-1,1'-biphenyl-4,4″-diamine (α-NPD) were investigated using laser desorption ionization (LDI) coupled with a time of flight mass spectrometry (TOF/MS). Especially chemical degradation pathways of the hole transport materials TCTA and α-NPD were investigated. The comparison of experimental data of unstressed and stressed device revealed that new reaction products are formed during the device operation. The linkage of TCTA fragments to the α-NPD core in an interfacial reaction as well as a dimerization of TCTA itself was observed. Ten new reaction products could be characterized via LDI-TOF-MS. Some of these compounds might possess a negative influence on the drop of efficiency and lifetime of blue light emitting devices based on FIrpic.

  20. Bright coppertunities: efficient OLED devices with copper(I)iodide-NHetPHOS-emitters

    NASA Astrophysics Data System (ADS)

    Wallesch, Manuela; Volz, Daniel; Fléchon, Charlotte; Zink, Daniel M.; Bräse, Stefan; Baumann, Thomas

    2014-10-01

    The mass market application of OLEDs is currently hindered because i) the materials are too expensive and contain rare metals such as iridium and ii) current processing techniques are elaborate and cannot easily be up-scaled. Solution processable Cu(I)-complexes promise to solve both problems with one blow: Copper is an abundant metal, which offers new opportunities to develop materials for OLEDs. Due to their structural diversity, Cu(I) emitters allow for the design of materials with tunable properties. Beside this, it is also possible to adjust solution properties and introduce functionalities for cross-linking. The new materials feature exciting photophysical properties such as PLQY values close to unity and a tunable emission. The emission decay times are in the range of common emitters or lower, which is expected to reduce efficiency roll-off at high driving voltages. Cu(I)-complexes often feature thermally-activated delayed fluorescence (TADF). As a consequence, they can make use of triplet and singlet excitons in a process called Singlet Harvesting, which paves the way for high efficiencies. Unlike Ir(III)-complexes such as Irppy3, triplet-triplet annihilation does not occur when using Cu(I), even in very high doping concentrations. The feasibility of NHetPHOS-type Cu(I)-complexes is demonstrated as well as strategies that enable a smart crosslinking process, where the Cu(I) emitters themselves play an important role. In addition, high-brightness devices, which were operated at medium voltages, yielding 50.000 cd m-2 are shown. In a showcase example, we recently presented a device with an external quantum efficiency greater than 20% with a solution processed Cu(I)-PyrPHOS-device without using outcoupling techniques.

  1. Supplemental Immobilization of Hanford Low-Activity Waste: Cast Stone Augmented Formulation Matrix Tests

    SciTech Connect

    Cozzi, A.; Crawford, C.; Fox, K.; Hansen, E.; Roberts, K.

    2015-07-20

    More than 56 million gallons of radioactive and hazardous waste are stored in 177 underground storage tanks at the U.S. Department of Energy’s (DOE’s) Hanford Site in Washington State. The HLW will be vitrified in the HLW facility for ultimate disposal at an offsite federal repository. A portion (~35%) of the LAW will be vitrified in the LAW vitrification facility for disposal onsite at the Integrated Disposal Facility (IDF). The pretreatment and HLW vitrification facilities will have the capacity to treat and immobilize all of the wastes destined for those facilities. However, a second facility will be needed for the expected volume of LAW requiring immobilization. Cast Stone, a cementitious waste form, is being considered to provide the required additional LAW immobilization capacity. The Cast Stone waste form must be acceptable for disposal in the IDF. The Cast Stone waste form and immobilization process must be tested to demonstrate that the final Cast Stone waste form can comply with the waste acceptance criteria for the disposal facility and that the immobilization processes can be controlled to consistently provide an acceptable waste form product. A testing program was developed in fiscal year (FY) 2012 describing in detail the work needed to develop and qualify Cast Stone as a waste form for the solidification of Hanford LAW. A statistically designed test matrix was used to evaluate the effects of key parameters on the properties of the Cast Stone as it is initially prepared and after curing. For the processing properties, the water-to-dry-blend mix ratio was the most significant parameter in affecting the range of values observed for each property. The single shell tank (SST) Blend simulant also showed differences in measured properties compared to the other three simulants tested. A review of the testing matrix and results indicated that an additional set of tests would be beneficial to improve the understanding of the impacts noted in the Screening

  2. Recovery Act: Low Cost Integrated Substrate for OLED Lighting Development

    SciTech Connect

    Benton, Scott; Bhandari, Abhinav

    2012-12-26

    PPG pursued the development of an integrated substrate, including the anode, external, and internal extraction layers. The objective of PPG's program was to achieve cost reductions by displacing the existing expensive borosilicate or double-side polished float glass substrates and developing alternative electrodes and scalable light extraction layer technologies through focused and short-term applied research. One of the key highlights of the project was proving the feasibility of using PPG's high transmission Solarphire® float glass as a substrate to consistently achieve organic lightemitting diode (OLED) devices with good performance and high yields. Under this program, four low-cost alternatives to the Indium Tin Oxide (ITO) anode were investigated using pilot-scale magnetron sputtered vacuum deposition (MSVD) and chemical vapor deposition (CVD) technologies. The anodes were evaluated by fabricating small and large phosphorescent organic lightemitting diode (PHOLED) devices at Universal Display Corporation (UDC). The device performance and life-times comparable to commercially available ITO anodes were demonstrated. A cost-benefit analysis was performed to down-select two anodes for further low-cost process development. Additionally, PPG developed and evaluated a number of scalable and compatible internal and external extraction layer concepts such as scattering layers on the outside of the glass substrate or between the transparent anode and the glass interface. In one external extraction layer (EEL) approach, sol-gel sprayed pyrolytic coatings were deposited using lab scale equipment by hand or automated spraying of sol-gel solutions on hot glass, followed by optimizing of scattering with minimal absorption. In another EEL approach, PPG tested large-area glass texturing by scratching a glass surface with an abrasive roller and acid etching. Efficacy enhancements of 1.27x were demonstrated using white PHOLED devices for 2.0mm substrates which are at par with

  3. Modulation of Active Site Electronic Structure by the Protein Matrix to Control [NiFe] Hydrogenase Reactivity

    SciTech Connect

    Smith, Dayle MA; Raugei, Simone; Squier, Thomas C.

    2014-09-30

    Control of the reactivity of the nickel center of the [NiFe] hydrogenase and other metalloproteins commonly involves outer coordination sphere ligands that act to modify the geometry and physical properties of the active site metal centers. We carried out a combined set of classical molecular dynamics and quantum/classical mechanics calculations to provide quantitative estimates of how dynamic fluctuations of the active site within the protein matrix modulate the electronic structure at the catalytic center. Specifically we focused on the dynamics of the inner and outer coordination spheres of the cysteinate-bound Ni–Fe cluster in the catalytically active Ni-C state. There are correlated movements of the cysteinate ligands and the surrounding hydrogen-bonding network, which modulate the electron affinity at the active site and the proton affinity of a terminal cysteinate. On the basis of these findings, we hypothesize a coupling between protein dynamics and electron and proton transfer reactions critical to dihydrogen production.

  4. Variance of matrix metalloproteinase (MMP) and tissue inhibitor of metalloproteinase (TIMP) concentrations in activated, concentrated platelets from healthy male donors

    PubMed Central

    2014-01-01

    Background The use of autologous blood concentrates, such as activated, concentrated platelets, in orthopaedic clinical applications has had mixed results. Research on this topic has focused on growth factors and cytokines, with little directed towards matrix metalloproteinases (MMPs) which are involved in post-wound tissue remodeling. Methods In this study, the authors measured the levels of MMP-2, MMP-9 and a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13 (ADAMTS13), in activated platelets derived from blood of healthy, male volunteers (n = 92), 19 to 60 years old. The levels of the natural inhibitors of these proteases, tissue inhibitor of metalloproteinase 1 (TIMP-1), TIMP-2 and TIMP-4 were also assessed. Results Notably, there was no significant change in concentration with age in four of six targets tested. However, TIMP-2 and TIMP-4 demonstrated a statistically significant increase in concentration for subjects older than 30 years of age compared to those 30 years and younger (P = 0.04 and P = 0.04, respectively). Conclusion TIMP-2 and TIMP-4 are global inhibitors of MMPs, including MMP-2 (Gelatinase A). MMP-2 targets native collagens, gelatin and elastin to remodel the extracellular matrix during wound healing. A decreased availability of pharmacologically active MMP-2 may diminish the effectiveness of the use of activated, concentrated platelets from older patients, and may also contribute to longer healing times in this population. PMID:24766991

  5. Quantum Dot Light Enhancement Substrate for OLED Solid-State Lighting

    SciTech Connect

    James Perkins; Matthew Stevenson; Gagan Mahan; Seth Coe-Sullivan; Peter Kazlas

    2011-01-21

    With DOE Award No. DE-EE00000628, QD Vision developed and demonstrated a cost-competitive solution for increasing the light extraction efficiency of OLEDs with efficient and stable color rendering index (CRI) for solid state lighting (SSL). Solution processable quantum dot (QD) films were integrated into OLED ITO-glass substrates to generate tunable white emission from blue emitting OLED) devices as well as outcouple light from the ITO film. This QD light-enhancement substrate (QD-LED) technology demonstrated a 60% increase in OLED forward light out-coupling, a value which increases to 76% when considering total increase in multi-directional light output. The objective for the first year was an 80% increase in light output. This project seeks to develop and demonstrate a cost-competitive solution for realizing increased extraction efficiency organic light emitting devices (OLEDs) with efficient and stable color rendering index (CRI) for SSL. Solution processible quantum dot (QD) films will be utilized to generate tunable white emission from blue emitting phosphorescent OLED (Ph-OLED) devices.

  6. Effect of thermal annealing Super Yellow emissive layer on efficiency of OLEDs

    NASA Astrophysics Data System (ADS)

    Burns, Samantha; MacLeod, Jennifer; Trang Do, Thu; Sonar, Prashant; Yambem, Soniya D.

    2017-01-01

    Thermal annealing of the emissive layer of an organic light emitting diode (OLED) is a common practice for solution processable emissive layers and reported annealing temperatures varies across a wide range of temperatures. We have investigated the influence of thermal annealing of the emissive layer at different temperatures on the performance of OLEDs. Solution processed polymer Super Yellow emissive layers were annealed at different temperatures and their performances were compared against OLEDs with a non-annealed emissive layer. We found a significant difference in the efficiency of OLEDs with different annealing temperatures. The external quantum efficiency (EQE) reached a maximum of 4.09% with the emissive layer annealed at 50 °C. The EQE dropped by ~35% (to 2.72%) for OLEDs with the emissive layers annealed at 200 °C. The observed performances of OLEDs were found to be closely related to thermal properties of polymer Super Yellow. The results reported here provide an important guideline for processing emissive layers and are significant for OLED and other organic electronics research communities.

  7. Effect of thermal annealing Super Yellow emissive layer on efficiency of OLEDs

    PubMed Central

    Burns, Samantha; MacLeod, Jennifer; Trang Do, Thu; Sonar, Prashant; Yambem, Soniya D.

    2017-01-01

    Thermal annealing of the emissive layer of an organic light emitting diode (OLED) is a common practice for solution processable emissive layers and reported annealing temperatures varies across a wide range of temperatures. We have investigated the influence of thermal annealing of the emissive layer at different temperatures on the performance of OLEDs. Solution processed polymer Super Yellow emissive layers were annealed at different temperatures and their performances were compared against OLEDs with a non-annealed emissive layer. We found a significant difference in the efficiency of OLEDs with different annealing temperatures. The external quantum efficiency (EQE) reached a maximum of 4.09% with the emissive layer annealed at 50 °C. The EQE dropped by ~35% (to 2.72%) for OLEDs with the emissive layers annealed at 200 °C. The observed performances of OLEDs were found to be closely related to thermal properties of polymer Super Yellow. The results reported here provide an important guideline for processing emissive layers and are significant for OLED and other organic electronics research communities. PMID:28106082

  8. Electroluminescence property of organic light emitting diode (OLED)

    SciTech Connect

    Özdemir, Orhan; Kavak, Pelin; Saatci, A. Evrim; Gökdemir, F. Pınar; Menda, U. Deneb; Can, Nursel; Kutlu, Kubilay; Tekin, Emine; Pravadalı, Selin

    2013-12-16

    Transport properties of electrons and holes were investigated not only in a anthracene-containing poly(p-phenylene-ethynylene)- alt - poly(p-phenylene-vinylene) (PPE-PPV) polymer (AnE-PVstat) light emitting diodes (OLED) but also in an ITO/Ag/polymer/Ag electron and ITO/PEDOT:PSS/polymer/Au hole only devices. Mobility of injected carriers followed the Poole-Frenkel type conduction mechanism and distinguished in the frequency range due to the difference of transit times in admittance measurement. Beginning of light output took place at the turn-on voltage (or flat band voltage), 1.8 V, which was the difference of energy band gap of polymer and two barrier offsets between metals and polymer.

  9. Recent progress in OLED and flexible displays and their potential for application to aerospace and military display systems

    NASA Astrophysics Data System (ADS)

    Sarma, Kalluri

    2015-05-01

    Organic light emitting diode (OLED) display technology has advanced significantly in recent years and it is increasingly being adapted in consumer electronics products with premium performance, such as high resolution smart phones, Tablet PCs and TVs. Even flexible OLED displays are beginning to be commercialized in consumer electronic devices such as smart phones and smart watches. In addition to the advances in OLED emitters, successful development and adoption of OLED displays for premium performance applications relies on the advances in several enabling technologies including TFT backplanes, pixel drive electronics, pixel patterning technologies, encapsulation technologies and system level engineering. In this paper we will discuss the impact of the recent advances in LTPS and AOS TFTs, R, G, B and White OLED with color filter pixel architectures, and encapsulation, on the success of the OLEDs in consumer electronic devices. We will then discuss potential of these advances in addressing the requirements of OLED and flexible displays for the military and avionics applications.

  10. Vascular smooth muscle cells from injured rat aortas display elevated matrix production associated with transforming growth factor-beta activity.

    PubMed Central

    Rasmussen, L. M.; Wolf, Y. G.; Ruoslahti, E.

    1995-01-01

    The arterial response to injury is characterized by a short period of increased proliferation and migration of vascular smooth muscle cells, followed by an extended period of extracellular matrix accumulation in the intima. Transforming growth factor-beta (TGF-beta) has been implicated as a causative factor in the formation of extracellular matrix in this process, which leads to progressive thickening of the intima, known as intimal hyperplasia. In vitro analysis of vascular smooth muscle cells harvested from normal rat aortas and from aortas injured 14 days earlier showed that both types of cells attached equally well to culture dishes but that the initial spreading of the cells was increased in cells derived from injured vessels. Cells from the injured arteries produced more fibronectin and proteoglycans into the culture medium than the cells from normal arteries and contained more TGF-beta 1 mRNA. TGF-beta 1 increased proteoglycan synthesis by normal smooth muscle cells, and the presence of a neutralizing anti-TGF-beta 1 antibody reduced proteoglycan synthesis by the cells from injured arteries in culture. Fibronectin synthesis was not altered by these treatments. These results indicate that the accumulation of extracellular matrix components in neointimal lesions is at least partially caused by autocrine TGF-beta activity in vascular smooth muscle cells. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 PMID:7573349

  11. Sunlight activated lanthanide complex for luminescent solar collector applications: effect of waveguide matrix

    NASA Astrophysics Data System (ADS)

    Shahi, Praveen Kumar; Singh, Priyam; Bahadur Rai, Shyam

    2017-02-01

    The performance of Eu(DBM)3Phen complex (EDP) dispersed in PMMA poly-(methyl methacrylate) polymer matrix, as simple planner luminescent solar collectors (LSCs) is demonstrated using spectroscopic and photovoltaic (PV) measurements. The organic ligands absorb ultra-violet-blue (UV-blue) radiation (220–450 nm) very efficiently and transfer its energy to the Eu3+ ion, which gives an intense red emission even in sunlight exposure. The excellent optical properties of EDP in PMMA permit its coating on the front surface of c-Si solar cell (10  ×  10 cm2) for PV measurements. The PV characterizations reveal the improvement in the short circuit current density (J sc) of PV cell and maximum improvement is found to be 4.6% for 2.5 wt% EDP concentration in PMMA matrix. The efficiency of solar cell increases from 17.22% to 18.33% for bare and 2.5% EDP in PMMA. At a higher concentration of EDP, the thin film starts losing its transparency and hence PV efficiency decreases. These results illustrate that a EDP complex combined with a PV cell could work as a prototype of a new generation solar cell.

  12. A relevant enzyme in granulomatous reaction, active matrix metalloproteinase-9, found in bovine Echinococcus granulosus hydatid cyst wall and fluid.

    PubMed

    Marco, M; Baz, A; Fernandez, C; Gonzalez, G; Hellman, U; Salinas, G; Nieto, A

    2006-12-01

    In addition to the ability of matrix metalloproteinases (MMP) to degrade components of the extracellular matrix and their involvement in pathology-related processes of tissue remodeling, they were recently reported to enhance inflammation by activation of proinflammatory cytokines, or their release from the cell surface. In the work reported here, proteolytic activity previously found for hydatid cysts was further characterized as MMP-9. Active host MMP-9 was found in walls and fluids of bovine hydatid cysts of Echinococcus granulosus in the environment of granulomatous reaction. Pooled walls and fluids of hydatid cysts obtained from infected cattle were processed. Strong proteolytic activity was detected by zymography. The proteolytic fraction was purified by anion exchange and gelatin-agarose affinity chromatography. Major proteinases of the purified fraction were subjected to mass spectrometry and their identities were further confirmed by Western blotting using commercial anti-human MMP-9 monoclonal antibodies. Two proteinases were characterized as latent and active forms of host MMP-9. Using the same antibody for immunoblot, activity was localized, in paraffin-embedded sections of the parasite and the local host environment, to epithelioid and giant multinucleated cells. It is proposed here that MMP-9 is secreted by specialized host cells of monocytic lineage (epithelioid/giant cells) as an effector, in an attempt to digest the persistent foreign body. In vivo activation of MMP-9 suggests its involvement in inflammatory reaction and in the chemotaxis of inflammatory cells to the cyst. However, E. granulosus can deal efficiently with MMP-9. Research is suggested into possible immune evasion mechanisms, including the secretion of an inhibitory molecule.

  13. Next Generation Hole Injection/Transport Nano-Composites for High Efficiency OLED Development

    SciTech Connect

    King Wang

    2009-07-31

    The objective of this program is to use a novel nano-composite material system for the OLED anode coating/hole transport layer. The novel anode coating is intended to significantly increase not only hole injection/transport efficiency, but the device energy efficiency as well. Another goal of the Core Technologies Program is the optimization and scale-up of air-stable and cross-linkable novel HTL nano-composite materials synthesis and the development of low-cost, large-scale mist deposition processes for polymer OLED fabrication. This proposed technology holds the promise to substantially improve OLED energy efficiency and lifetime.

  14. Broccoli and watercress suppress matrix metalloproteinase-9 activity and invasiveness of human MDA-MB-231 breast cancer cells

    SciTech Connect

    Rose, Peter . E-mail: bchpcr@nus.edu.sg; Huang, Qing; Ong, Choon Nam; Whiteman, Matt

    2005-12-01

    A high dietary intake of cruciferous vegetables has been associated with a reduction in numerous human pathologies particularly cancer. In the current study, we examined the inhibitory effects of broccoli (Brassica oleracea var. italica) and watercress (Rorripa nasturtium aquaticum) extracts on 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced cancer cell invasion and matrix metalloproteinase-9 activity using human MDA-MB-231 breast cancer cells. Aberrant overexpression of matrix metalloproteinases, including metalloproteinase-9, is associated with increased invasive potential in cancer cell lines. Our results demonstrate that extracts of broccoli and Rorripa suppressed TPA-induced MMP-9 activity and invasiveness in a concentration dependant manner as determined by zymographic analysis. Furthermore, fractionation of individual extracts followed by liquid chromatography mass spectroscopy analysis (LC-MS) revealed that the inhibitory effects of each vegetable were associated with the presence of 4-methysulfinylbutyl (sulforaphane) and 7-methylsulphinylheptyl isothiocyanates. Taken together, our data indicate that isothiocyanates derived form broccoli and Rorripa inhibit metalloproteinase 9 activities and also suppress the invasive potential of human MDA-MB-231 breast cancer cells in vitro. The inhibitory effects observed in the current study may contribute to the suppression of carcinogenesis by diets high in cruciferous vegetables.

  15. Broccoli and watercress suppress matrix metalloproteinase-9 activity and invasiveness of human MDA-MB-231 breast cancer cells.

    PubMed

    Rose, Peter; Huang, Qing; Ong, Choon Nam; Whiteman, Matt

    2005-12-01

    A high dietary intake of cruciferous vegetables has been associated with a reduction in numerous human pathologies particularly cancer. In the current study, we examined the inhibitory effects of broccoli (Brassica oleracea var. italica) and watercress (Rorripa nasturtium aquaticum) extracts on 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced cancer cell invasion and matrix metalloproteinase-9 activity using human MDA-MB-231 breast cancer cells. Aberrant overexpression of matrix metalloproteinases, including metalloproteinase-9, is associated with increased invasive potential in cancer cell lines. Our results demonstrate that extracts of broccoli and Rorripa suppressed TPA-induced MMP-9 activity and invasiveness in a concentration dependent manner as determined by zymographic analysis. Furthermore, fractionation of individual extracts followed by liquid chromatography mass spectroscopy analysis (LC-MS) revealed that the inhibitory effects of each vegetable were associated with the presence of 4-methysulfinylbutyl (sulforaphane) and 7-methylsulphinylheptyl isothiocyanates. Taken together, our data indicate that isothiocyanates derived form broccoli and Rorripa inhibit metalloproteinase 9 activities and also suppress the invasive potential of human MDA-MB-231 breast cancer cells in vitro. The inhibitory effects observed in the current study may contribute to the suppression of carcinogenesis by diets high in cruciferous vegetables.

  16. Components of the Human SWI/SNF Complex Are Enriched in Active Chromatin and Are Associated with the Nuclear Matrix

    PubMed Central

    Reyes, Jose C.; Muchardt, Christian; Yaniv, Moshe

    1997-01-01

    Biochemical and genetic evidence suggest that the SWI/SNF complex is involved in the remodeling of chromatin during gene activation. We have used antibodies specific against three human subunits of this complex to study its subnuclear localization, as well as its potential association with active chromatin and the nuclear skeleton. Immunofluorescence studies revealed a punctate nuclear labeling pattern that was excluded from the nucleoli and from regions of condensed chromatin. Dual labeling failed to reveal significant colocalization of BRG1 or hBRM proteins with RNA polymerase II or with nuclear speckles involved in splicing. Chromatin fractionation experiments showed that both soluble and insoluble active chromatin are enriched in the hSWI/SNF proteins as compared with bulk chromatin. hSWI/SNF proteins were also found to be associated with the nuclear matrix or nuclear scaffold, suggesting that a fraction of the hSWI/SNF complex could be involved in the chromatin organization properties associated with matrix attachment regions. PMID:9128241

  17. Novel inhibitors of urokinase-type plasminogen activator and matrix metalloproteinase expression in metastatic cancer cell lines.

    PubMed

    Cakarovski, Kristina; Leung, Jenny Y; Restall, Christina; Carin-Carlson, Anna; Yang, Eunice; Perlmutter, Patrick; Anderson, Robin; Medcalf, Robert; Dear, Anthony E

    2004-07-01

    The plasminogen-activating (PA) and matrix metalloproteinase (MMP) enzyme systems are implicated in proteolytic turnover of the extracellular matrix (ECM) associated with biologic processes including wound healing, inflammation and angiogenesis. Aberrant expression of components of the PA and MMP enzyme systems occurs in the pathogenesis of metastatic cancer. Oxamflatin (Ox), a novel hydroxamic acid derivative, inhibits u-PA mRNA expression and proteolytic activity while simultaneously upregulating the expression of the natural inhibitor of u-PA, plasminogen activator inhibitor type 2 (PAI-2) in metastatic cancer cells. We have characterized the effects of Ox and a novel derivative, Metacept-1 (MCT-1), on PA and MMP-mediated proteolysis and invasion in several metastatic tumor lines. Both compounds are able to inhibit u-PA-, MMP-2- and MMP-9-mediated gene expression at low micromolar concentrations as well as u-PA- and MMP-mediated proteolysis as assessed by zymography, with MCT-1 being the more effective of the 2 agents in some assays. Cellular invasion assays correlate with gene expression and zymography experiments identifying both Ox and MCT-1 as able to inhibit invasion of metastatic cancer cell lines through matrigel at nanomolar concentrations, with MCT-1 more effective than Ox in 2 of the 3 cancer cell lines assessed.

  18. The matrix metalloproteinase gene GmMMP2 is activated in response to pathogenic infections in soybean.

    PubMed

    Liu, Y; Dammann, C; Bhattacharyya, M K

    2001-12-01

    Matrix metalloproteinases (MMPs) play an important role in host defense responses against pathogens in mammals where their activities lead to the production of antimicrobial peptides. We have identified a novel soybean (Glycine max) metalloproteinase gene, GmMMP2, that is transcriptionally up-regulated in infected tissues. The deduced amino acid sequence indicates that this gene belongs to the MMP family. It is a preproprotein containing an N-terminal signal peptide, a cysteine switch, a zinc-binding catalytic motif, and a C-terminal transmembrane domain. The GmMMP2 expressed in and purified from Escherichia coli exhibited an in vitro enzymatic activity in digesting myelin basic protein. All plant metalloproteinases reported so far have no known functions. However, they have been suggested to be involved in extracellular cell matrix degradation during development or senescence. Our investigations demonstrate that the GmMMP2 transcript levels were rapidly increased in compatible and incompatible interactions of soybean tissues with the oomycete pathogen Phytophthora sojae or the bacterial pathogen Pseudomonas syringae pv. glycinea. In agreement with the GmMMP2 activation, a metalloproteinase activity was gradually increased in suspension-cultured cells following the bacterial infection. GmMMP2 was also activated in response to wounding and dehydration. However, GmMMP2 activation did not correlate with the oxidative burst leading to the hypersensitive response cell death or the tissue senescence progress that involves programmed cell death. Our investigations suggest that GmMMP2 may be involved in a novel defense response of soybean against pathogenic infections.

  19. Targeted SPECT/CT Imaging of Matrix Metalloproteinase Activity in the Evaluation of Remodeling Tissue-Engineered Vascular Grafts Implanted in a Growing Lamb Model

    PubMed Central

    Stacy, Mitchel R.; Naito, Yuji; Maxfield, Mark W.; Kurobe, Hirotsugu; Tara, Shuhei; Chan, Chung; Rocco, Kevin A.; Shinoka, Toshiharu; Sinusas, Albert J.; Breuer, Christopher K.

    2014-01-01

    Objective(s) The clinical translation of tissue-engineered vascular grafts has been demonstrated in children. The remodeling of biodegradable, cell-seeded scaffolds to functional neovessels is partially attributed to matrix metalloproteinases. Noninvasive assessment of matrix metalloproteinase activity may indicate graft remodeling and elucidate the progression of neovessel formation. Therefore, matrix metalloproteinase activity was evaluated in grafts implanted in lambs using in vivo and ex vivo hybrid imaging. Graft growth and remodeling was quantified using in vivo X-ray computed tomography angiography. Methods Cell-seeded and unseeded scaffolds were implanted in lambs (n=5) as inferior vena cava interposition grafts. At 2 and 6 months post-implantation, in vivo angiography assessed graft morphology. In vivo and ex vivo single photon emission tomography/X-ray computed tomography imaging was performed with a radiolabeled compound targeting matrix metalloproteinase activity at 6 months. Neotissue was examined at 6 months using qualitative histologic and immunohistochemical staining and quantitative biochemical analysis. Results Seeded grafts demonstrated significant luminal and longitudinal growth from 2 to 6 months. In vivo imaging revealed subjectively higher matrix metalloproteinase activity in grafts vs. native tissue. Ex vivo imaging confirmed a quantitative increase in matrix metalloproteinase activity and demonstrated higher activity in unseeded vs. seeded grafts. Glycosaminoglycan content was increased in seeded grafts vs. unseeded grafts, without significant differences in collagen content. Conclusions Matrix metalloproteinase activity remains elevated in tissue-engineered grafts 6 months post-implantation and may indicate remodeling. Optimization of in vivo imaging to noninvasively evaluate matrix metalloproteinase activity may assist in serial assessment of vascular graft remodeling. PMID:24952823

  20. Mueller-matrix ellipsometry studies of optically active structures in scarab beetles

    NASA Astrophysics Data System (ADS)

    Järrendahl, K.; Landin, J.; Arwin, H.

    2010-06-01

    The complexity of multilayers, photonic crystals, metamaterials and other artificial materials has promoted the use of spectroscopic, variable angle, generalized and Mueller-matrix ellipsometry. Naturally occurring structures may show even higher complexity than artificial structures but with a more narrow range of constituent materials. Fascinating reflection properties result from intricate photonic structures in, for instance, the wing scales and cuticles of insects. Currently there is a large interest to explore such functional supramolecular architectures for exploitation in nanotechnology. In this study, Mueller-matrix spectroscopic ellipsometry is applied in the spectral range of 250 to 1000 nm to investigate optical response and structures of the cuticle of Scarab beetles of the Cetoniinae subfamily. The cuticle of Cetonia aurata (the rose chafer, la cétoine dorée) is green with a metallic appearance and reflects left-handed circular/elliptically polarized light. It has been suggested that the polarization of this metallic gloss is caused by a helical structure in the chitinous cuticle. We find that the polarization effect is limited to the narrow spectral range 470-550 nm whereas for shorter or longer wavelengths the reflection properties are similar to those from a near-dielectric material. Model calculations and parameterization of the nanostructure employing a heliocoidal structure are discussed. As a comparison the polarization effects from light reflected from two other beetles will be presented. Coptomia laevis has a similar appearance as Cetonia aurata but has very different polarization properties. The golden Plusiotis argentiola has very interesting properties showing both left and right-handed polarization depending on incidence angle and wavelength.

  1. Wnt-3a-activated human fibroblasts promote human keratinocyte proliferation and matrix destruction.

    PubMed

    Sobel, Katrin; Tham, Marius; Stark, Hans-Jürgen; Stammer, Hermann; Prätzel-Wunder, Silke; Bickenbach, Jackie R; Boukamp, Petra

    2015-06-15

    Aberrant Wnt regulation, detectable by nuclear translocation of beta-catenin, is a hallmark of many cancers including skin squamous cell carcinomas (SCCs). By analyzing primary human skin SCCs, we demonstrate that nuclear beta-catenin is not restricted to SCC cells but also detected in stromal fibroblasts, suggesting an important role for aberrant Wnt regulation also in the tumor microenvironment. When human keratinocytes and fibroblasts were treated with Wnt-3a, fibroblasts proved to be more responsive. Accordingly, Wnt-3a did not alter HaCaT cell functions in a cell-autonomous manner. However, when organotypic cultures (OTCs) were treated with Wnt-3a, HaCaT keratinocytes responded with increased proliferation. As nuclear beta-catenin was induced only in the fibroblasts, this argued for a Wnt-dependent, paracrine keratinocyte stimulation. Global gene expression analysis of Wnt-3a-stimulated fibroblasts identified genes encoding interleukin-8 (IL-8) and C-C motif chemokine 2 (CCL-2) as well as matrix metalloproteinase-1 (MMP-1) as Wnt-3a targets. In agreement, we show that IL-8 and CCL-2 were secreted in high amounts by Wnt-3a-stimulated fibroblasts also in OTCs. The functional role of IL-8 and CCL-2 as keratinocyte growth regulators was confirmed by directly stimulating HaCaT cell proliferation in conventional cultures. Most important, neutralizing antibodies against IL-8 and CCL-2 abolished the Wnt-dependent HaCaT cell hyperproliferation in OTCs. Additionally, MMP-1 was expressed in high amounts in Wnt-3a-stimulated OTCs and degraded the stromal matrix. Thus, our data show that Wnt-3a stimulates fibroblasts to secrete both keratinocyte proliferation-inducing cytokines and stroma-degrading metalloproteinases, thereby providing evidence for a novel Wnt deregulation in the tumor-stroma directly contributing to skin cancer progression.

  2. Novel nuclear matrix protein HET binds to and influences activity of the HSP27 promoter in human breast cancer cells.

    PubMed

    Oesterreich, S; Lee, A V; Sullivan, T M; Samuel, S K; Davie, J R; Fuqua, S A

    1997-11-01

    Since the small heat shock protein hsp27 enhances both growth and drug resistance in breast cancer cells, and is a bad prognostic factor in certain subsets of breast cancer patients, we have characterized the transcriptional regulation of hsp27, with the long-term goal of targeting its expression clinically. The majority of the promoter activity resides in the most proximal 200 bp. This region contains an imperfect estrogen response element (ERE) that is separated by a 13-bp spacer that contains a TATA box. Gel-shift analysis revealed the binding of a protein (termed HET for Hsp27-ERE-TATA-binding protein) to this region that was neither the estrogen receptor nor TATA-binding protein. We cloned a complete cDNA (2.9 kb) for HET from an MCF-7 cDNA library. To confirm the identity of the HET clone, we expressed a partial HET clone as a glutathione S-transferase fusion protein, and showed binding to the hsp27 promoter fragment in gel-retardation assays. The HET clone is almost identical to a recently published scaffold attachment factor (SAF-B) cloned from a HeLa cell cDNA library. Scaffold attachment factors are a subset of nuclear matrix proteins (NMP) that interact with matrix attachment regions. Analyzing how HET could act as a regulator of hsp27 transcription and as a SAF/NMP, we studied its subnuclear localization and its effect on hsp27 transcription in human breast cancer cells. We were able to show that HET is localized in the nuclear matrix in various breast cancer cell lines. Furthermore, in transient transfection assays using hsp27 promoter-luciferase reporter constructs, HET overexpression resulted in a dose-dependent decrease of hsp27 promoter activity in several cell lines.

  3. PPARα and PPARγ attenuate HIV-induced dysregulation of tight junction proteins by modulations of matrix metalloproteinase and proteasome activities

    PubMed Central

    Huang, Wen; Eum, Sung Yong; András, Ibolya E; Hennig, Bernhard; Toborek, Michal

    2009-01-01

    The blood-brain barrier (BBB) plays an important role in HIV trafficking into the brain and the development of the central nervous system complications in HIV infection. Tight junctions are the main structural and functional elements that regulate the BBB integrity. Exposure of human brain microvascular endothelial cells (hCMEC/D3 cell line) to HIV-infected monocytes resulted in decreased expression of tight junction proteins, such as junctional adhesion molecule-A (JAM)-A, occludin, and zonula occludens (ZO)-1. Control experiments involved exposure to uninfected monocytes. Alterations of tight junction protein expression were associated with increased endothelial permeability and elevated transendothelial migration of HIV-infected monocytes across an in vitro model of the BBB. Notably, overexpression of the peroxisome proliferator-activated receptor (PPAR)α or PPARγ attenuated HIV-mediated dysregulation of tight junction proteins. With the use of exogenous PPARγ agonists and silencing of PPARα or PPARγ, these protective effects were connected to down-regulation of matrix metalloproteinase (MMP) and proteasome activities. Indeed, the HIV-induced decrease in the expression of JAM-A and occludin was restored by inhibition of MMP activity. Moreover, both MMP and proteasome inhibitors attenuated HIV-mediated altered expression of ZO-1. The present data indicate that down-regulation of MMP and proteasome activities constitutes a novel mechanism of PPAR-induced protections against HIV-induced disruption of brain endothelial cells.—Huang, W., Eum, S. Y., András, I. E., Hennig, B., Toborek, M. PPARα and PPARγ attenuate HIV-induced dysregulation of tight junction proteins by modulations of matrix metalloproteinase and proteasome activities. PMID:19141539

  4. Expression of membrane-type 1 matrix metalloproteinase and activation of progelatinase A in human osteoarthritic cartilage.

    PubMed Central

    Imai, K.; Ohta, S.; Matsumoto, T.; Fujimoto, N.; Sato, H.; Seiki, M.; Okada, Y.

    1997-01-01

    Matrix metalloproteinases (MMPs) are expressed in osteoarthritic (OA) cartilage and are thought to be involved in the degradation of cartilage extracellular matrix (ECM). Among these proteinases, MMP-2 (gelatinase A) demonstrates a wide range of substrate specificity against the ECM present in cartilage. Although MMP-2 expression increases in OA cartilage, the activation mechanism of the corresponding zymogen (pro-MMP-2) in cartilage is unknown. In this study, we examined the expression pattern of membrane-type 1 MMP (MT1-MMP) in human OA articular cartilage and its correlation with the activation of pro-MMP-2. Immunohistochemical studies demonstrate that MT1-MMP localizes to the chondrocytes in the superficial and transitional zones in all of the samples examined directly correlating with cartilage degradation. Reverse transcription polymerase chain reaction confirmed the predominant expression of MT1-MMP mRNA in the OA cartilage. In situ hybridization revealed the site of expression of MT1-MMP in OA cartilage to be the chondrocytes. Through gelatin zymography and a sandwich enzyme immunoassay it was demonstrated that OA cartilage explants secrete significantly higher levels of pro-MMP-2 than normal samples. Pro-MMP-2 activation was enhanced in the OA cartilage samples and correlated with MT1-MMP expression in the cartilage. Plasma membranes prepared from cultured chondrocytes with MT1-MMP expression and those directly isolated from OA cartilage could activate pro-MMP-2. MT1-MMP gene expression in cultured chondrocytes was induced by treatment with interleukin-1 alpha and/or tumor necrosis factor-alpha. These data suggest that cytokine-induced MT1-MMP in the chondrocytes may play a key role in the activation of pro-MMP-2 in the OA articular cartilage, leading to cartilage destruction through ECM degradation. Images Figure 1 Figure 3 Figure 4 Figure 5 Figure 7 Figure 8 PMID:9212749

  5. Approach to In- Situ Producing Reinforcing Phase Within an Active-Transient Liquid Phase Bond Seam for Aluminum Matrix Composite

    NASA Astrophysics Data System (ADS)

    Zhang, Guifeng; Liao, Xianjin; Chen, Bo; Zhang, Linjie; Zhang, Jianxun

    2015-06-01

    To optimize the braze composition design route for aluminum matrix composite, the feasibility of in situ producing reinforcing phase within the transient liquid phase bond seam matrix, by adding active melting point increaser (MPI, e.g., Ti) together with general melting point depressant (MPD, e.g., Cu) into the interlayer, was demonstrated. For SiC p /A356 composite, by comparing the wettability, joint microstructure, joint shear strength, and fracture path for the developed Al-19Cu-1Ti, Al-19Cu, Al-33Cu-1Ti, Al-33Cu (wt pct), and commercial Cu foils as interlayer, the feasibility of in situ producing reinforcing phase within the bond seam by adding Ti was demonstrated. Especially for Al-19Cu-1Ti active braze, small and dispersed ternary aluminide of Al-Si-Ti phase was obtained within the bond seam as in situ reinforcement, leading to a favorable fracture path within SiC p /A356, not along the initial interface or within the bond seam. For the formation mechanism of the in situ reinforcing phase of MPI-containing intermetallic compound within the bond seam, a model of repeating concentration-precipitation-termination-engulfment during isothermal solidification is proposed.

  6. The influence of opioid peptides on matrix metalloproteinase-9 and urokinase plasminogen activator expression in three cancer cell lines.

    PubMed

    Gach, K; Wyrebska, A; Szemraj, J; Janecka, A

    2012-01-01

    Matrix metalloproteinases (MMPs) and urokinase plasminogen activator (uPA) regulate proteolysis of the extracellular matrix (ECM) and as a consequence are involved in a number of physiological and pathological states, including cancer. A crucial feature of cancer progression and metastasis is the disruption of the ECM and spreading of proliferating cancer cells. Over-expression of MMPs and uPA is common for most types of cancers and correlates well with the adverse prognosis. Compounds able to modulate the activity of these proteolytic enzymes may become important agents in cancer therapy. In the present study, we examined the effect of the mu-opioid receptor selective peptide, morphiceptin, and its two synthetic analogs on mRNA and protein levels of MMP-9 and uPA in three human cancer cell lines: MCF-7, HT-29, and SH-SY5Y. Our findings indicate that in all three cell lines morphiceptin and its analogs attenuated MMP-9 expression and secretion and that this effect is not mediated by opioid receptors but is under control of the nitric oxide system. On the other hand, tested opioids up-regulated uPA levels through a mechanism that involved opioid-receptors. Different pathways by which opioid peptides exert their actionin cancer cells can explain their contradictory influence on the level of cancer markers.

  7. Soft lithography microlens fabrication and array for enhanced light extraction from organic light emitting diodes (OLEDs)

    DOEpatents

    Leung, Wai Y.; Park, Joong-Mok; Gan, Zhengqing; Constant, Kristen P.; Shinar, Joseph; Shinar, Ruth; ho, Kai-Ming

    2014-06-03

    Provided are microlens arrays for use on the substrate of OLEDs to extract more light that is trapped in waveguided modes inside the devices and methods of manufacturing same. Light extraction with microlens arrays is not limited to the light emitting area, but is also efficient in extracting light from the whole microlens patterned area where waveguiding occurs. Large microlens array, compared to the size of the light emitting area, extract more light and result in over 100% enhancement. Such a microlens array is not limited to (O)LEDs of specific emission, configuration, pixel size, or pixel shape. It is suitable for all colors, including white, for microcavity OLEDs, and OLEDs fabricated directly on the (modified) microlens array.

  8. Crystal Structures of Xanthomonas campestris OleA Reveal Features That Promote Head-to-Head Condensation of Two Long-Chain Fatty Acids

    SciTech Connect

    Goblirsch, BR; Frias, JA; Wackett, LP; Wilmot, CM

    2012-05-22

    OleA is a thiolase superfamily enzyme that has been shown to catalyze the condensation of two long-chain fatty acylcoenzyme A (CoA) substrates. The enzyme is part of a larger gene cluster responsible for generating long-chain olefin products, a potential biofuel precursor. In thiolase superfamily enzymes, catalysis is achieved via a ping-pong mechanism. The first substrate forms a covalent intermediate with an active site cysteine that is followed by reaction with the second substrate. For OleA, this conjugation proceeds by a nondecarboxylative Claisen condensation. The OleA from Xanthomonas campestris has been crystallized and its structure determined, along with inhibitor-bound and xenon-derivatized structures, to improve our understanding of substrate positioning in the context of enzyme turnover. OleA is the first characterized thiolase superfamily member that has two long-chain alkyl substrates that need to be bound simultaneously and therefore uniquely requires an additional alkyl binding channel. The location of the fatty acid biosynthesis inhibitor, cerulenin, that possesses an alkyl chain length in the range of known OleA substrates, in conjunction with a single xenon binding site, leads to the putative assignment of this novel alkyl binding channel. Structural overlays between the OleA homologues, 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) synthase and the fatty acid biosynthesis enzyme FabH, allow assignment of the two remaining channels: one for the thioester-containing pantetheinate arm and the second for the alkyl group of one substrate. A short beta-hairpin region is ordered in only one of the crystal forms, and that may suggest open and closed states relevant for substrate binding. Cys143 is the conserved catalytic cysteine within the superfamily, and the site of alkylation by cerulenin. The alkylated structure suggests that a glutamic acid residue (Glu117 beta) likely promotes Claisen condensation by acting as the catalytic base. Unexpectedly, Glu117

  9. Crystal Structures of Xanthomonas campestris OleA Reveal Features That Promote Head-to-Head Condensation of Two Long-Chain Fatty Acids

    SciTech Connect

    Goblirsch, Brandon R.; Frias, Janice A.; Wackett, Lawrence P.; Wilmot, Carrie M.

    2012-10-25

    OleA is a thiolase superfamily enzyme that has been shown to catalyze the condensation of two long-chain fatty acyl-coenzyme A (CoA) substrates. The enzyme is part of a larger gene cluster responsible for generating long-chain olefin products, a potential biofuel precursor. In thiolase superfamily enzymes, catalysis is achieved via a ping-pong mechanism. The first substrate forms a covalent intermediate with an active site cysteine that is followed by reaction with the second substrate. For OleA, this conjugation proceeds by a nondecarboxylative Claisen condensation. The OleA from Xanthomonas campestris has been crystallized and its structure determined, along with inhibitor-bound and xenon-derivatized structures, to improve our understanding of substrate positioning in the context of enzyme turnover. OleA is the first characterized thiolase superfamily member that has two long-chain alkyl substrates that need to be bound simultaneously and therefore uniquely requires an additional alkyl binding channel. The location of the fatty acid biosynthesis inhibitor, cerulenin, that possesses an alkyl chain length in the range of known OleA substrates, in conjunction with a single xenon binding site, leads to the putative assignment of this novel alkyl binding channel. Structural overlays between the OleA homologues, 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) synthase and the fatty acid biosynthesis enzyme FabH, allow assignment of the two remaining channels: one for the thioester-containing pantetheinate arm and the second for the alkyl group of one substrate. A short {beta}-hairpin region is ordered in only one of the crystal forms, and that may suggest open and closed states relevant for substrate binding. Cys143 is the conserved catalytic cysteine within the superfamily, and the site of alkylation by cerulenin. The alkylated structure suggests that a glutamic acid residue (Glu117{beta}) likely promotes Claisen condensation by acting as the catalytic base. Unexpectedly

  10. Hydrogen sulfide inhibits high glucose-induced matrix protein synthesis by activating AMP-activated protein kinase in renal epithelial cells.

    PubMed

    Lee, Hak Joo; Mariappan, Meenalakshmi M; Feliers, Denis; Cavaglieri, Rita C; Sataranatarajan, Kavithalakshmi; Abboud, Hanna E; Choudhury, Goutam Ghosh; Kasinath, Balakuntalam S

    2012-02-10

    Hydrogen sulfide, a signaling gas, affects several cell functions. We hypothesized that hydrogen sulfide modulates high glucose (30 mm) stimulation of matrix protein synthesis in glomerular epithelial cells. High glucose stimulation of global protein synthesis, cellular hypertrophy, and matrix laminin and type IV collagen content was inhibited by sodium hydrosulfide (NaHS), an H(2)S donor. High glucose activation of mammalian target of rapamycin (mTOR) complex 1 (mTORC1), shown by phosphorylation of p70S6 kinase and 4E-BP1, was inhibited by NaHS. High glucose stimulated mTORC1 to promote key events in the initiation and elongation phases of mRNA translation: binding of eIF4A to eIF4G, reduction in PDCD4 expression and inhibition of its binding to eIF4A, eEF2 kinase phosphorylation, and dephosphorylation of eEF2; these events were inhibited by NaHS. The role of AMP-activated protein kinase (AMPK), an inhibitor of protein synthesis, was examined. NaHS dose-dependently stimulated AMPK phosphorylation and restored AMPK phosphorylation reduced by high glucose. Compound C, an AMPK inhibitor, abolished NaHS modulation of high glucose effect on events in mRNA translation as well as global and matrix protein synthesis. NaHS induction of AMPK phosphorylation was inhibited by siRNA for calmodulin kinase kinase β, but not LKB1, upstream kinases for AMPK; STO-609, a calmodulin kinase kinase β inhibitor, had the same effect. Renal cortical content of cystathionine β-synthase and cystathionine γ-lyase, hydrogen sulfide-generating enzymes, was significantly reduced in mice with type 1 diabetes or type 2 diabetes, coinciding with renal hypertrophy and matrix accumulation. Hydrogen sulfide is a newly identified modulator of protein synthesis in the kidney, and reduction in its generation may contribute to kidney injury in diabetes.

  11. Modulation of matrix metalloproteinase-9 activity by hyaluronan is dependent on NF-kappaB activity in lymphoma cell lines with dissimilar invasive behavior.

    PubMed

    Alaniz, Laura; García, Mariana; Cabrera, Paula; Arnaiz, María; Cavaliere, Victoria; Blanco, Guillermo; Alvarez, Elida; Hajos, Silvia

    2004-11-12

    Expression and activity of matrix metalloproteinase-9 (MMP-9) as well as its relationship with hyaluronan (HA) and NF-kappaB activity were analyzed in two murine lymphoma cell lines with dissimilar migration and invasive behavior. MMP activity was evaluated by zymograms in supernatants, membrane extracts of tumor cells, and in the organs invaded by these cells. The more aggressive LBLa cell line showed MMP-9 activity in vitro, which increased after HA treatment and was blocked by anti-CD44 mAb. Such activity was not found in the less aggressive LBLc. MMP-9 and MMP-2 activity was found in organs invaded by both cell lines, although differential MMP-9 activity was observed in lung infiltrated only by LBLa cell line. NF-kappaB activation was evaluated to determine whether differential activity of MMP-9 was dependent on downstream signaling pathway, showing higher NF-kappaB activity in the more aggressive LBLa cell line. Our results showed that MMP-9 activity modulated by HA through NF-kappaB signaling pathway may be involved in the aggressive behavior of LBLa.

  12. A matrix-focused structure-activity and binding site flexibility study of quinolinol inhibitors of botulinum neurotoxin serotype A.

    PubMed

    Harrell, William A; Vieira, Rebecca C; Ensel, Susan M; Montgomery, Vicki; Guernieri, Rebecca; Eccard, Vanessa S; Campbell, Yvette; Roxas-Duncan, Virginia; Cardellina, John H; Webb, Robert P; Smith, Leonard A

    2017-02-01

    Our initial discovery of 8-hydroxyquinoline inhibitors of BoNT/A and separation/testing of enantiomers of one of the more active leads indicated considerable flexibility in the binding site. We designed a limited study to investigate this flexibility and probe structure-activity relationships; utilizing the Betti reaction, a 36 compound matrix of quinolinol BoNT/A LC inhibitors was developed using three 8-hydroxyquinolines, three heteroaromatic amines, and four substituted benzaldehydes. This study has revealed some of the most effective quinolinol-based BoNT/A inhibitors to date, with 7 compounds displaying IC50 values ⩽1μM and 11 effective at ⩽2μM in an ex vivo assay.

  13. Testing the toxicity of influents to activated sludge plants with the Vibrio fischeri bioassay utilising a sludge matrix.

    PubMed

    Hoffmann, C; Christofi, N

    2001-10-01

    To protect the bioceonosis within activated sludge, a method of predicting the toxic effect of influents to the biological treatment stage of waste water treatment plants, based on DIN method 38412 L 34, has been developed. A population of the luminescent marine bacterium Vibrio fischeri was incorporated into a sludge testing matrix derived from a model laboratory and real activated sludge plants. The sludge was challenged with different concentrations of pure toxicants and complex aqueous samples, and light output by V. fischeri monitored. The results were compared to toxicant testing in the absence of sludge (standard test). The modified method was found to be less sensitive for some toxicants tested than the standard DIN and other bioluminescent tests, but considered more realistic as it provides buffering and takes into account sorption which can affect the sensitivity of the test towards some compounds. The method is comparable in terms of ease of use, speed, reproducibility and cost effectiveness to standard V. fischeri luminescence methods.

  14. Dual side transparent OLED 3D display using Gabor super-lens

    NASA Astrophysics Data System (ADS)

    Chestak, Sergey; Kim, Dae-Sik; Cho, Sung-Woo

    2015-03-01

    We devised dual side transparent 3D display using transparent OLED panel and two lenticular arrays. The OLED panel is sandwiched between two parallel confocal lenticular arrays, forming Gabor super-lens. The display provides dual side stereoscopic 3D imaging and floating image of the object, placed behind it. The floating image can be superimposed with the displayed 3D image. The displayed autostereoscopic 3D images are composed of 4 views, each with resolution 64x90 pix.

  15. Matrix metalloproteinase 13 modulates intestinal epithelial barrier integrity in inflammatory diseases by activating TNF

    PubMed Central

    Vandenbroucke, Roosmarijn E; Dejonckheere, Eline; Van Hauwermeiren, Filip; Lodens, Sofie; De Rycke, Riet; Van Wonterghem, Elien; Staes, An; Gevaert, Kris; López-Otin, Carlos; Libert, Claude

    2013-01-01

    Several pathological processes, such as sepsis and inflammatory bowel disease (IBD), are associated with impairment of intestinal epithelial barrier. Here, we investigated the role of matrix metalloproteinase MMP13 in these diseases. We observed that MMP13−/− mice display a strong protection in LPS- and caecal ligation and puncture-induced sepsis. We could attribute this protection to reduced LPS-induced goblet cell depletion, endoplasmic reticulum stress, permeability and tight junction destabilization in the gut of MMP13−/− mice compared to MMP13+/+ mice. Both in vitro and in vivo, we found that MMP13 is able to cleave pro-TNF into bioactive TNF. By LC-MS/MS, we identified three MMP13 cleavage sites, which proves that MMP13 is an alternative TNF sheddase next to the TNF converting enzyme TACE. Similarly, we found that the same mechanism was responsible for the observed protection of the MMP13−/− mice in a mouse model of DSS-induced colitis. We identified MMP13 as an important mediator in sepsis and IBD via the shedding of TNF. Hence, we propose MMP13 as a novel drug target for diseases in which damage to the gut is essential. PMID:23723167

  16. Accelerated biodegradation of silk sutures through matrix metalloproteinase activation by incorporating 4-hexylresorcinol

    PubMed Central

    Jo, You-Young; Kweon, HaeYong; Kim, Dae-Won; Kim, Min-Keun; Kim, Seong-Gon; Kim, Jwa-Young; Chae, Weon-Sik; Hong, Sam-Pyo; Park, Young-Hwan; Lee, Si Young; Choi, Je-Yong

    2017-01-01

    Silk suture material is primarily composed of silk fibroin and regarded as a non-resorbable material. It is slowly degraded by proteolysis when it is implanted into the body. 4-Hexylresorcinol (4HR) is a well-known antiseptic. In this study, the biodegradability of 4HR-incorporated silk sutures were compared to that of untreated silk sutures and polyglactin 910 sutures, a commercially available resorbable suture. 4HR-incorporated silk sutures exhibited anti-microbial properties. Matrix metalloproteinase (MMP) can digest a wide spectrum of proteins. 4HR increased MMP-2, -3, and -9 expression in RAW264.7 cells. MMP-2, -3, and -9 were able to digest not only silk fibroin but also silk sutures. Consequently, 59.5% of the 4HR-incorporated silk suture material remained at 11 weeks after grafting, which was similar to that of polyglactin 910 degradation (56.4% remained). The residual amount of bare silk suture material at 11 weeks after grafting was 91.5%. The expression levels of MMP-2, -3 and -9 were high in the 4HR-incorporated silk suture-implanted site 12 weeks after implantation. In conclusion, 4HR-treated silk sutures exhibited anti-microbial properties and a similar level of bio-degradation to polyglactin 910 sutures and induced higher expression of MMP-2, -3, and -9 in macrophages. PMID:28205580

  17. Matrix Producing Cells in Chronic Kidney Disease: Origin, Regulation, and Activation.

    PubMed

    Kramann, Rafael; Dirocco, Derek P; Maarouf, Omar H; Humphreys, Benjamin D

    2013-12-01

    Chronic injury to the kidney causes kidney fibrosis with irreversible loss of functional renal parenchyma and leads to the clinical syndromes of chronic kidney disease (CKD) and end-stage renal disease (ESRD). Regardless of the type of initial injury, kidney disease progression follows the same pathophysiologic processes characterized by interstitial fibrosis, capillary rarefaction and tubular atrophy. Myofibroblasts play a pivotal role in fibrosis by driving excessive extracellular matrix (ECM) deposition. Targeting these cells in order to prevent the progression of CKD is a promising therapeutic strategy, however, the cellular source of these cells is still controversial. In recent years, a growing amount of evidence points to resident mesenchymal cells such as pericytes and perivascular fibroblasts, which form extensive networks around the renal vasculature, as major contributors to the pool of myofibroblasts in renal fibrogenesis. Identifying the cellular origin of myofibroblasts and the key regulatory pathways that drive myofibroblast proliferation and transdifferentiation as well as capillary rarefaction is the first step to developing novel anti-fibrotic therapeutics to slow or even reverse CKD progression and ultimately reduce the prevalence of ESRD. This review will summarize recent findings concerning the cellular source of myofibroblasts and highlight recent discoveries concerning the key regulatory signaling pathways that drive their expansion and progression in CKD.

  18. The electrodeposition of multilayers on a polymeric substrate in Flexible Organic Light Emitting Diode (OLED)

    NASA Astrophysics Data System (ADS)

    Guedes, Andre F. S.; Guedes, Vilmar P.; Tartari, Simone; Cunha, Idaulo Jose

    2016-09-01

    The development of Organic Light Emitting Diode (OLED), using an optically transparent substrate material and organic semiconductor materials, has been widely utilized by the electronic industry when producing new technological products. The OLED are the base Poly(3,4-ethylenedioxythiophene), PEDOT, Poly(p-phenylenevinylene), PPV, and Polyaniline, PANI, were deposited in Indium Tin Oxide, ITO, and characterized by UV-Visible Spectroscopy (UV-Vis), Optical Parameters (OP) and Scanning Electron Microscopy (SEM). In addition, the thin film obtained by the deposition of PANI, prepared in perchloric acid solution, was identified through PANI-X1. The result obtained by UV-Vis has demonstrated that the PET/ITO/PEDOT/PPV/PANI-X1/Al layer does not have displacement of absorption for wavelengths greaters after spin-coating and electrodeposition. Thus, the spectral irradiance of the OLED informed the irradiance of 100 W/m2, and this result, compared with the standard Light Emitting Diode (LED), has indicated that the OLED has higher irradiance. After 1200 hours of electrical OLED tests, the appearance of nanoparticles visible for images by SEM, to the migration process of organic semiconductor materials, was present, then. Still, similar to the phenomenon of electromigration observed in connections and interconnections of microelectronic devices, the results have revealed a new mechanism of migration, which raises the passage of electric current in OLED.

  19. Flexible low-power-consumption OLED displays for a universal communication device

    NASA Astrophysics Data System (ADS)

    Hack, Michael G.; Chwang, Anna B.; Lu, Min-Hao M.; Kwong, Raymond C.; Weaver, Michael S.; Tung, Yeh-Jiun; Brown, Julie J.

    2003-09-01

    In this paper we will outline the technical challenges and progress towards enabling a novel communication device based on a roll-out, low power consumption, OLED display. Advanced mobile communication devices require a bright, high information content display in a small, light-weight, low power consumption package. We believe that phosphorescent OLED (PHOLED) technology fabricated on a truly flexible substrate, enables a mobile Universal Communication Device (UCD) to offer a high information content display in an extendable form, while rolling up into a small form factor when not in use. This communication device is of great interest for a range of both consumer and military applications. From the display perspective, the key component is achieving a long-lived, low power consumption display. We believe the OLEDs are the preferred display media, and in this talk we will outline our flexible phosphorescent OLED technology. The key to reliable operation is to ensure that the organic materials are fully encapsulated in a package designed for repetitive flexing. UDC has been developing long-lived flexible OLED (FOLED) displays based on plastic substrates and multi-layer monolithic encapsulation. Recent progress in this area will also be reported. Finally, we will outline the backplane requirements for flexible OLED displays and compare the various technology options that can be used to fabricate the UCD.

  20. Detection of active matrix metalloproteinase-3 in serum and fibroblast-like synoviocytes of collagen-induced arthritis mice.

    PubMed

    Lee, Aeju; Choi, Sung-Jae; Park, Kyeongsoon; Park, Jong Woong; Kim, Kwangmeyung; Choi, Kuiwon; Yoon, Soo-Young; Youn, Inchan

    2013-06-19

    The activity of rheumatoid arthritis (RA) correlates with the expression of proteases. Among several proteases, matrix metalloproteinase-3 (MMP-3) is one of the biological markers used to diagnose RA. The active form of MMP-3 is a key enzyme involved in RA-associated destruction of cartilage and bone. Thus, detection of active MMP-3 in serum or in vivo is very important for early diagnosis of RA. In this study, a soluble MMP-3 probe was prepared to monitor RA progression by detecting expression of active MMP-3 in collagen-induced arthritis (CIA) mice in vivo in both serum and fibroblast-like synoviocytes (FLSs). The MMP-3 probe exhibited strong sensitivity to MMP-3 and moderate sensitivity to MMP-7 at nanomolecular concentrations, but was not sensitive to other MMPs such as MMP-2, MMP-9, and MMP-13. In an optical imaging study, the MMP-3 probe produced early and strong NIR fluorescence signals prior to observation of erythema and swelling in CIA mice. The MMP-3 probe was able to rapidly and selectively detect and monitor active MMP-3 in diluted serum from CIA mice. Furthermore, histological data demonstrated that activated FLSs in arthritic knee joints expressed active MMP-3. Together, our results demonstrated that the MMP-3 probe may be useful for detecting active MMP-3 for diagnosis of RA. More importantly, the MMP-3 probe was able to detect active MMP-3 in diluted serum with high sensitivity. Therefore, the MMP-3 probe developed in this study may be a very promising probe, useful as a biomarker for early detection and diagnosis of RA.

  1. Molecular structures and dynamics of the stepwise activation mechanism of a matrix metalloproteinase zymogen: challenging the cysteine switch dogma.

    PubMed

    Rosenblum, Gabriel; Meroueh, Samy; Toth, Marta; Fisher, Jed F; Fridman, Rafael; Mobashery, Shahriar; Sagi, Irit

    2007-11-07

    Activation of matrix metalloproteinase zymogen (pro-MMP) is a vital homeostatic process, yet its molecular basis remains unresolved. Using stopped-flow X-ray spectroscopy of the active site zinc ion, we determined the temporal sequence of pro-MMP-9 activation catalyzed by tissue kallikrein protease in milliseconds to several minutes. The identity of three intermediates seen by X-ray spectroscopy was corroborated by molecular dynamics simulations and quantum mechanics/molecular mechanics calculations. The cysteine-zinc interaction that maintains enzyme latency is disrupted via active-site proton transfers that mediate transient metal-protein coordination events and eventual binding of water. Unexpectedly, these events ensue as a direct result of complexation of pro-MMP-9 and kallikrein and occur before proteolysis and eventual dissociation of the pro-peptide from the catalytic site. Here we demonstrate the synergism among long-range protein conformational transitions, local structural rearrangements, and fine atomic events in the process of zymogen activation.

  2. Hydrogen sulfide mitigates matrix metalloproteinase-9 activity and neurovascular permeability in hyperhomocysteinemic mice.

    PubMed

    Tyagi, Neetu; Givvimani, Srikanth; Qipshidze, Natia; Kundu, Soumi; Kapoor, Shray; Vacek, Jonathan C; Tyagi, Suresh C

    2010-01-01

    An elevated level of homocysteine (Hcy), known as hyperhomocysteinemia (HHcy), was associated with neurovascular diseases. At physiological levels, hydrogen sulfide (H(2)S) protected the neurovascular system. Because Hcy was also a precursor of hydrogen sulfide (H(2)S), we sought to test whether the H(2)S protected the brain during HHcy. Cystathionine-beta-synthase heterozygous (CBS+/-) and wild type (WT) mice were supplemented with or without NaHS (30 microM/L, H(2)S donor) in drinking water. Blood flow and cerebral microvascular permeability in pial vessels were measured by intravital microscopy in WT, WT+NaHS, CBS-/+ and (CBS-/+)+NaHS-treated mice. The brain tissues were analyzed for matrix metalloproteinase (MMP) and tissue inhibitor of metalloproteinase (TIMP) by Western blot and RT-PCR. The mRNA levels of CBS and cystathionine gamma lyase (CSE, enzyme responsible for conversion of Hcy to H(2)S) genes were measured by RT-PCR. The results showed a significant increase in MMP-2, MMP-9, TIMP-3 protein and mRNA in CBS (-/+) mice, while H(2)S treatment mitigated this increase. Interstitial localization of MMPs was also apparent through immunohistochemistry. A decrease in protein and mRNA expression of TIMP-4 was observed in CBS (-/+) mice. Microscopy data revealed increase in permeability in CBS (-/+) mice. These effects were ameliorated by H(2)S and suggested that physiological levels of H(2)S supplementation may have therapeutic potential against HHcy-induced microvascular permeability, in part, by normalizing the MMP/TIMP ratio in the brain.

  3. Ag@AgI, core@shell structure in agarose matrix as hybrid: synthesis, characterization, and antimicrobial activity.

    PubMed

    Ghosh, Somnath; Saraswathi, A; Indi, S S; Hoti, S L; Vasan, H N

    2012-06-05

    A novel in situ core@shell structure consisting of nanoparticles of Ag (Ag Nps) and AgI in agarose matrix (Ag@AgI/agarose) has been synthesized as a hybrid, in order to have an efficient antibacterial agent for repetitive usage with no toxicity. The synthesized core@shell structure is very well characterized by XRD, UV-visible, photoluminescence, and TEM. A detailed antibacterial studies including repetitive cycles are carried out on Gram-negative Escherichia coli (E. coli) and Gram-positive Staphylococcus aureus (S. aureus) bacteria in saline water, both in dark and on exposure to visible light. The hybrid could be recycled for the antibacterial activity and is nontoxic toward human cervical cancer cells (HeLa cells). The water insoluble Ag@AgI in agarose matrix forms a good coating on quartz, having good mechanical strength. EPR and TEM studies are carried out on the Ag@AgI/agarose and the bacteria, respectively, to elucidate a possible mechanism for killing of the bacteria.

  4. Transcriptional activation by a matrix associating region-binding protein. contextual requirements for the function of bright.

    PubMed

    Kaplan, M H; Zong, R T; Herrscher, R F; Scheuermann, R H; Tucker, P W

    2001-06-15

    Bright (B cell regulator of IgH transcription) is a B cell-specific, matrix associating region-binding protein that transactivates gene expression from the IgH intronic enhancer (E mu). We show here that Bright has multiple contextual requirements to function as a transcriptional activator. Bright cannot transactivate via out of context, concatenated binding sites. Transactivation is maximal on integrated substrates. Two of the three previously identified binding sites in E mu are required for full Bright transactivation. The Bright DNA binding domain defined a new family, which includes SWI1, a component of the SWI.SNF complex shown to have high mobility group-like DNA binding characteristics. Similar to one group of high mobility group box proteins, Bright distorts E mu binding site-containing DNA on binding, supporting the concept that it mediates E mu remodeling. Transfection studies further implicate Bright in facilitating spatially separated promoter-enhancer interactions in both transient and stable assays. Finally, we show that overexpression of Bright leads to enhanced DNase I sensitivity of the endogenous E mu matrix associating regions. These data further suggest that Bright may contribute to increased gene expression by remodeling the immunoglobulin locus during B cell development.

  5. Turbocharged molecular discovery of OLED emitters: from high-throughput quantum simulation to highly efficient TADF devices

    NASA Astrophysics Data System (ADS)

    Gómez-Bombarelli, Rafael; Aguilera-Iparraguirre, Jorge; Hirzel, Timothy D.; Ha, Dong-Gwang; Einzinger, Markus; Wu, Tony; Baldo, Marc A.; Aspuru-Guzik, Alán.

    2016-09-01

    Discovering new OLED emitters requires many experiments to synthesize candidates and test performance in devices. Large scale computer simulation can greatly speed this search process but the problem remains challenging enough that brute force application of massive computing power is not enough to successfully identify novel structures. We report a successful High Throughput Virtual Screening study that leveraged a range of methods to optimize the search process. The generation of candidate structures was constrained to contain combinatorial explosion. Simulations were tuned to the specific problem and calibrated with experimental results. Experimentalists and theorists actively collaborated such that experimental feedback was regularly utilized to update and shape the computational search. Supervised machine learning methods prioritized candidate structures prior to quantum chemistry simulation to prevent wasting compute on likely poor performers. With this combination of techniques, each multiplying the strength of the search, this effort managed to navigate an area of molecular space and identify hundreds of promising OLED candidate structures. An experimentally validated selection of this set shows emitters with external quantum efficiencies as high as 22%.

  6. Regulation of Matrix Metalloproteinase-2 Activity by COX-2-PGE2-pAKT Axis Promotes Angiogenesis in Endometriosis

    PubMed Central

    Ray, Amlan K.; DasMahapatra, Pramathes; Swarnakar, Snehasikta

    2016-01-01

    Endometriosis is characterized by the ectopic development of the endometrium which relies on angiogenesis. Although studies have identified the involvement of different matrix metalloproteinases (MMPs) in endometriosis, no study has yet investigated the role of MMP-2 in endometriosis-associated angiogenesis. The present study aims to understand the regulation of MMP-2 activity in endothelial cells and on angiogenesis during progression of ovarian endometriosis. Histological and biochemical data showed increased expressions of vascular endothelial growth factor (VEGF), VEGF receptor-2, cycloxygenase (COX)-2, von Willebrand factor along with angiogenesis during endometriosis progression. Women with endometriosis showed decreased MMP-2 activity in eutopic endometrium as compared to women without endometriosis. However, ectopic ovarian endometrioma showed significantly elevated MMP-2 activity with disease severity. In addition, increased MT1MMP and decreased tissue inhibitors of metalloproteinases (TIMP)-2 expressions were found in the late stages of endometriosis indicating more MMP-2 activation with disease progression. In vitro study using human endothelial cells showed that prostaglandin E2 (PGE2) significantly increased MMP-2 activity as well as tube formation. Inhibition of COX-2 and/or phosphorylated AKT suppressed MMP-2 activity and endothelial tube formation suggesting involvement of PGE2 in regulation of MMP-2 activity during angiogenesis. Moreover, specific inhibition of MMP-2 by chemical inhibitor significantly reduced cellular migration, invasion and tube formation. In ovo assay showed decreased angiogenic branching upon MMP-2 inhibition. Furthermore, a significant reduction of lesion numbers was observed upon inhibition of MMP-2 and COX-2 in mouse model of endometriosis. In conclusion, our study establishes the involvement of MMP-2 activity via COX-2-PGE2-pAKT axis in promoting angiogenesis during endometriosis progression. PMID:27695098

  7. Conformable, flexible, large-area networks of pressure and thermal sensors with organic transistor active matrixes

    NASA Astrophysics Data System (ADS)

    Someya, Takao; Kato, Yusaku; Sekitani, Tsuyoshi; Iba, Shingo; Noguchi, Yoshiaki; Murase, Yousuke; Kawaguchi, Hiroshi; Sakurai, Takayasu

    2005-08-01

    Skin-like sensitivity, or the capability to recognize tactile information, will be an essential feature of future generations of robots, enabling them to operate in unstructured environments. Recently developed large-area pressure sensors made with organic transistors have been proposed for electronic artificial skin (E-skin) applications. These sensors are bendable down to a 2-mm radius, a size that is sufficiently small for the fabrication of human-sized robot fingers. Natural human skin, however, is far more complex than the transistor-based imitations demonstrated so far. It performs other functions, including thermal sensing. Furthermore, without conformability, the application of E-skin on three-dimensional surfaces is impossible. In this work, we have successfully developed conformable, flexible, large-area networks of thermal and pressure sensors based on an organic semiconductor. A plastic film with organic transistor-based electronic circuits is processed to form a net-shaped structure, which allows the E-skin films to be extended by 25%. The net-shaped pressure sensor matrix was attached to the surface of an egg, and pressure images were successfully obtained in this configuration. Then, a similar network of thermal sensors was developed with organic semiconductors. Next, the possible implementation of both pressure and thermal sensors on the surfaces is presented, and, by means of laminated sensor networks, the distributions of pressure and temperature are simultaneously obtained. Author contributions: T. Someya designed research; T. Someya, Y.K., T. Sekitani, S.I., Y.N., Y.M., H.K., and T. Sakurai performed research; and T. Someya wrote the paper.This paper was submitted directly (Track II) to the PNAS office.Freely available online through the PNAS open access option.Abbreviations: E-skin, electronic artificial skin; IDS, source-drain current; PTCDI, 3,4,9,10-perylene-tetracarboxylic-diimide; parylene, polychloro-para-xylylene; CuPc, copper

  8. New concept for in-line OLED manufacturing

    NASA Astrophysics Data System (ADS)

    Hoffmann, U.; Landgraf, H.; Campo, M.; Keller, S.; Koening, M.

    2011-03-01

    A new concept of a vertical In-Line deposition machine for large area white OLED production has been developed. The concept targets manufacturing on large substrates (>= Gen 4, 750 x 920 mm2) using linear deposition source achieving a total material utilization of >= 50 % and tact time down to 80 seconds. The continuously improved linear evaporation sources for the organic material achieve thickness uniformity on Gen 4 substrate of better than +/- 3 % and stable deposition rates down to less than 0.1 nm m/min and up to more than 100 nm m/min. For Lithium-Fluoride but also for other high evaporation temperature materials like Magnesium or Silver a linear source with uniformity better than +/- 3 % has been developed. For Aluminum we integrated a vertical oriented point source using wire feed to achieve high (> 150 nm m/min) and stable deposition rates. The machine concept includes a new vertical vacuum handling and alignment system for Gen 4 shadow masks. A complete alignment cycle for the mask can be done in less than one minute achieving alignment accuracy in the range of several 10 μm.

  9. Hole-Rich Host Materials for Blue Phosphorescent OLEDs

    SciTech Connect

    Cosimbescu, Lelia; Polikarpov, Evgueni; Swensen, James S.; Darsell, Jens T.; Padmaperuma, Asanga B.

    2011-04-01

    Stable and efficient organic light emitting devices (OLEDs) are an integral part of the future of lighting and displays. The hole accumulation at the hole transport/emissive layer interface in such devices is considered to be a major pathway for degradation and efficiency loss. Here we report the design and synthesis of two charge-transporting host materials, based on the phosphine oxide (PO) moiety, engineered to improve hole transport of the emissive layer. The compounds are an extension of a molecular design strategy already explored and reported by our team which incorporates a hole transporting moiety and an electron transporting moiety. These novel materials were designed with two hole transport moieties (HTms) to further improve hole transport, compared to the first generation host materials that were designed with one hole transport functional group. The triplet exciton energy was maintained at a level greater than that of FIrpic (2.7 eV) to prevent exciton quenching. The EHOMO and ELUMO of the two classes of molecules (i.e., one HTm vs. 2 HTms) were similar, however their device performance varied greatly. Emission zone experiments were conducted to further understand the differences between molecules.

  10. Surface treatment on polyethylenimine interlayer to improve inverted OLED performance

    NASA Astrophysics Data System (ADS)

    Wei, Chang-Ting; Zhuang, Jin-Yong; Chen, Ya-Li; Zhang, Dong-Yu; Su, Wen-Ming; Cui, Zheng

    2016-10-01

    Polyethylenimine (PEI) interlayer rinsing with different solvents for inverted organic light emitting diodes (OLEDs) is systematically studied in this paper. In comparison with the pristine one, the maximum current efficiency (CE max) and power efficiency (PE max) are enhanced by 21% and 22% for the device rinsing by ethylene glycol monomethyl ether (EEA). Little effect is found on the work function of the PEI interlayer rinsed by deionized water (DI), ethanol (EtOH), and EEA. On the other hand, the surface morphologies of PEI through different solvent treatments are quite different. Our results indicates that the surface morphology is the key to improving the device performance for IOLED as the work function of PEI keeps stable. Project supported by the National Key Basic Research Project of China (Grant No. 2015CB351901), the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No. XDA09020201), the Youth Innovation Promotion Association of Chinese Academy of Sciences (Grant No. 2013206), the National Natural Science Foundation of China (Grant No. 21402233), and the Natural Science Foundation of Jiangsu Province, China (Grant Nos. BK2012631 and BK20140387).

  11. Density matrix renormalization group (DMRG) method as a common tool for large active-space CASSCF/CASPT2 calculations

    NASA Astrophysics Data System (ADS)

    Nakatani, Naoki; Guo, Sheng

    2017-03-01

    This paper describes an interface between the density matrix renormalization group (DMRG) method and the complete active-space self-consistent field (CASSCF) method and its analytical gradient, as well as an extension to the second-order perturbation theory (CASPT2) method. This interfacing allows large active-space multi-reference computations to be easily performed. The interface and its extension are both implemented in terms of reduced density matrices (RDMs) which can be efficiently computed via the DMRG sweep algorithm. We also present benchmark results showing that, in practice, the DMRG-CASSCF calculations scale with active-space size in a polynomial manner in the case of quasi-1D systems. Geometry optimization of a binuclear iron-sulfur cluster using the DMRG-CASSCF analytical gradient is demonstrated, indicating that the inclusion of the valence p-orbitals of sulfur and double-shell d-orbitals of iron lead to non-negligible changes in the geometry compared to the results of small active-space calculations. With the exception of the selection of M values, many computational settings in these practical DMRG calculations have been tuned and black-boxed in our interface, and so the resulting DMRG-CASSCF and DMRG-CASPT2 calculations are now available to novice users as a common tool to compute strongly correlated electronic wavefunctions.

  12. Performance evaluation of nonnegative matrix factorization algorithms to estimate task-related neuronal activities from fMRI data.

    PubMed

    Ding, Xiaoyu; Lee, Jong-Hwan; Lee, Seong-Whan

    2013-04-01

    Nonnegative matrix factorization (NMF) is a blind source separation (BSS) algorithm which is based on the distinct constraint of nonnegativity of the estimated parameters as well as on the measured data. In this study, according to the potential feasibility of NMF for fMRI data, the four most popular NMF algorithms, corresponding to the following two types of (1) least-squares based update [i.e., alternating least-squares NMF (ALSNMF) and projected gradient descent NMF] and (2) multiplicative update (i.e., NMF based on Euclidean distance and NMF based on divergence cost function), were investigated by using them to estimate task-related neuronal activities. These algorithms were applied firstly to individual data from a single subject and, subsequently, to group data sets from multiple subjects. On the single-subject level, although all four algorithms detected task-related activation from simulated data, the performance of multiplicative update NMFs was significantly deteriorated when evaluated using visuomotor task fMRI data, for which they failed in estimating any task-related neuronal activities. In group-level analysis on both simulated data and real fMRI data, ALSNMF outperformed the other three algorithms. The presented findings may suggest that ALSNMF appears to be the most promising option among the tested NMF algorithms to extract task-related neuronal activities from fMRI data.

  13. α-Solanine inhibits human melanoma cell migration and invasion by reducing matrix metalloproteinase-2/9 activities.

    PubMed

    Lu, Ming-Kun; Shih, Yuan-Wei; Chang Chien, Tzu-Tsung; Fang, Li-Heng; Huang, Hsiang-Ching; Chen, Pin-Shern

    2010-01-01

    α-Solanine, a naturally occurring steroidal glycoalkaloid in potato sprouts, was found to possess anti-carcinogenic properties, such as inhibiting proliferation and inducing apoptosis of tumor cells. However, the effect of α-solanine on cancer metastasis remains unclear. In the present study, we examined the effect of α-solanine on metastasis in vitro. Data demonstrated that α-solanine inhibited proliferation of human melanoma cell line A2058 in a dose-dependent manner. When treated with non-toxic doses of α-solanine, cell migration and invasion were markedly suppressed. Furthermore, α-solanine reduced the activity of matrix metalloproteinase-2 (MMP-2) and MMP-9, which are involved in the migration and invasion of cancer cells. Our biochemical assays indicated that α-solanine potently suppressed the phosphorylation of c-Jun N-terminal kinase (JNK), phosphatidylinositide-3 kinase (PI3K) and Akt, while it did not affect phosphorylation of extracellular signal regulating kinase (ERK). In addition, α-solanine significantly decreased the nuclear level of nuclear factor kappa B (NF-κB), suggesting that α-solanine inhibited NF-κB activity. Taken together, the results suggested that α-solanine inhibited migration and invasion of A2058 cells by reducing MMP-2/9 activities. It also inhibited JNK and PI3K/Akt signaling pathways as well as NF-κB activity. These findings reveal new therapeutic potential for α-solanine in anti-metastatic therapy.

  14. AMPK Activation by Metformin Suppresses Abnormal Extracellular Matrix Remodeling in Adipose Tissue and Ameliorates Insulin Resistance in Obesity.

    PubMed

    Luo, Ting; Nocon, Allison; Fry, Jessica; Sherban, Alex; Rui, Xianliang; Jiang, Bingbing; Xu, X Julia; Han, Jingyan; Yan, Yun; Yang, Qin; Li, Qifu; Zang, Mengwei

    2016-08-01

    Fibrosis is emerging as a hallmark of metabolically dysregulated white adipose tissue (WAT) in obesity. Although adipose tissue fibrosis impairs adipocyte plasticity, little is known about how aberrant extracellular matrix (ECM) remodeling of WAT is initiated during the development of obesity. Here we show that treatment with the antidiabetic drug metformin inhibits excessive ECM deposition in WAT of ob/ob mice and mice with diet-induced obesity, as evidenced by decreased collagen deposition surrounding adipocytes and expression of fibrotic genes including the collagen cross-linking regulator LOX Inhibition of interstitial fibrosis by metformin is likely attributable to the activation of AMPK and the suppression of transforming growth factor-β1 (TGF-β1)/Smad3 signaling, leading to enhanced systemic insulin sensitivity. The ability of metformin to repress TGF-β1-induced fibrogenesis is abolished by the dominant negative AMPK in primary cells from the stromal vascular fraction. TGF-β1-induced insulin resistance is suppressed by AMPK agonists and the constitutively active AMPK in 3T3L1 adipocytes. In omental fat depots of obese humans, interstitial fibrosis is also associated with AMPK inactivation, TGF-β1/Smad3 induction, aberrant ECM production, myofibroblast activation, and adipocyte apoptosis. Collectively, integrated AMPK activation and TGF-β1/Smad3 inhibition may provide a potential therapeutic approach to maintain ECM flexibility and combat chronically uncontrolled adipose tissue expansion in obesity.

  15. A strategy to establish a gene-activated matrix on titanium using gene vectors protected in a polylactide coating.

    PubMed

    Kolk, Andreas; Haczek, Cornelia; Koch, Christian; Vogt, Stephan; Kullmer, Martin; Pautke, Christoph; Deppe, Herbert; Plank, Christian

    2011-10-01

    Bioactive implants are promising tools in regenerative medicine. Here we describe a versatile procedure for preparing a gene-activated matrix on titanium. Lyophilized copolymer-protected gene vectors (COPROGs) suspended in poly(d,l-lactide) (PDLLA) solutions in ethyl acetate were used to varnish solid surfaces. The gene-activated PDLLA surfaces were first established on polypropylene 96-well plates. Vector release from these surfaces in aqueous buffer, cell viability and gene transfer efficiency to NIH 3T3 fibroblasts was strongly dependent on the vector dose and its ratio to PDLLA film thickness. A detailed analysis of these relationships allowed establishing correlations which can be used to calculate suitable combinations of COPROGs and PDLLA yielding optimal gene transfer efficiency. This was verified with COPROG-activated PDLLA coatings on titanium foils. HEK 293 and mesenchymal stem cells expressed the BMP-2 gene comprised in the gene-activated surface in a manner that was consistent with the predicted dose-response and toxicity profiles found in NIH 3T3 cells. The systematic procedure presented here for identifying optimal coating compositions can be applied to any combination of vector type and coating material.

  16. An Antifungal Combination Matrix Identifies a Rich Pool of Adjuvant Molecules that Enhance Drug Activity Against Diverse Fungal Pathogens

    PubMed Central

    Robbins, Nicole; Spitzer, Michaela; Yu, Tennison; Cerone, Robert P.; Averette, Anna K.; Bahn, Yong-Sun; Heitman, Joseph; Sheppard, Donald C.; Tyers, Mike; Wright, Gerard D.

    2015-01-01

    SUMMARY There is an urgent need to identify new treatments for fungal infections. By combining sub-lethal concentrations of the known antifungals fluconazole, caspofungin, amphotericin B, terbinafine, benomyl and cyprodinil with ~3600 compounds in diverse fungal species, we generated a deep reservoir of chemical-chemical interactions termed the Antifungal Combinations Matrix (ACM). Follow-up susceptibility testing against a fluconazole resistant isolate of C. albicans unveiled ACM combinations capable of potentiating fluconazole in this clinical strain. We used chemical genetics to elucidate the mode-of-action of the antimycobacterial drug clofazimine, a compound with unreported antifungal activity that synergized with several antifungals. Clofazimine induces a cell membrane stress for which the Pkc1 signaling pathway is required for tolerance. Further tests against additional fungal pathogens, including Aspergillus fumigatus, highlighted that clofazimine exhibits efficacy as a combination agent against multiple fungi. Thus, the ACM is a rich reservoir of chemical combinations with therapeutic potential against diverse fungal pathogens. PMID:26549450

  17. Inhibitory effect of acetylsalicylic acid on matrix metalloproteinase - 2 activity in human endothelial cells exposed to high glucose.

    PubMed

    Nicolae, Manuela; Tircol, Magdalena; Alexandru, Dorin

    2005-01-01

    Matrix metalloproteinases play a major role in the process of angiogenesis, an important feature of diabetes complications, cancer or rheumatoid arthritis. High glucose concentrations were reported to augment metalloproteinase-2 secretion in some cell types. In the present study we investigated the influence of acetylsalicylic acid on metalloproteinase- 2 secretion and expression in endothelial cells cultured for one week in high glucose conditions (25 mM and 33 mM). Metalloproteinase-2 activity was evidenced by gel zymography, the protein was identified by Western blotting, and the gene expression was quantitated by RT-PCR. The results indicated a marked inhibitory effect of acetylsalicylic acid at gene expression level (approximately 43%) and also at secretion level in samples of conditioned media (approximately 30%) and cellular homogenates (approximately 70%). This may suggest that acetylsalicylic acid could have a beneficial effect in preventing the angiogenic process that appears in diabetes complications.

  18. Separating DDTs in edible animal fats using matrix solid-phase dispersion extraction with activated carbon filter, Toyobo-KF.

    PubMed

    Furusawa, Naoto

    2006-09-01

    A technique is presented for the economical, routine, and quantitative analysis of contamination by dichloro-diphenyl-trichloroethanes (DDTs) [pp'-DDT, pp'-dichlorodiphenyl dichloroethylene, and pp'-dichlorodiphenyl dichloreothane in beef tallow and chicken fat samples, based on their separation using matrix solid-phase dispersion (MSPD) extraction with Toyobo-KF, an activated carbon fiber. Toyobo-KF is a newly applied MSPD sorbent, and it is followed by reversed-phase high-performance liquid chromatography (HPLC) with a photodiode array detector. The resulting analytical performance parameters [recoveries of spiked DDTs (0.1, 0.2, and 0.4 microg/g) > or = 81%, with relative standard deviations of < or = 8% (n = 5), and quantitation limits < or = 0.03 microg/g], with minimal handling and cost-efficiency, indicate that the present MSPD-HPLC method may be a useful tool for routine monitoring of DDT contamination in meat.

  19. A signal processing approach for enhanced Acoustic Emission data analysis in high activity systems: Application to organic matrix composites

    NASA Astrophysics Data System (ADS)

    Kharrat, M.; Ramasso, E.; Placet, V.; Boubakar, M. L.

    2016-03-01

    Structural elements made of Organic Matrix Composites (OMC) under complex loading may suffer from high Acoustic Emission (AE) activity caused by the emergence of different emission sources at high rates with high noise level, which finally engender continuous emissions. The detection of hits in this situation becomes a challenge particularly during fatigue tests. This work suggests an approach based on the Discrete Wavelet Transform (DWT) denoising applied on signal segments. A particular attention is paid to the adjustment of the denoising parameters based on pencil lead breaks and their influence on the quality of the denoised AE signals. The validation of the proposed approach is performed on a ring-shaped Carbon Fiber Reinforced Plastics (CFRP) under in-service-like conditions involving continuous emissions with superimposed damage-related transients. It is demonstrated that errors in hit detection are greatly reduced leading to a better identification of the natural damage scenario based on AE signals.

  20. Correlating In Vitro Target-Oriented Screening and Docking: Inhibition of Matrix Metalloproteinases Activities by Flavonoids.

    PubMed

    Crascì, Lucia; Basile, Livia; Panico, Annamaria; Puglia, Carmelo; Bonina, Francesco P; Basile, Pierluigi Maria; Rizza, Luisa; Guccione, Salvatore

    2017-03-13

    Metalloproteases are a family of zinc-containing endopeptidases involved in a variety of pathological disorders. The use of flavonoid derivatives as potential metalloprotease inhibitors has recently increased.Particular plants growing in Sicily are an excellent yielder of the flavonoids luteolin, apigenin, and their respective glycoside derivatives (7-O-rutinoside, 7-O-glucoside, and 7-O-glucuronide).The inhibitory activity of luteolin, apigenin, and their respective glycoside derivatives on the metalloproteases MMP-1, MMP-3, MMP-13, MMP-8, and MMP-9 was assessed and rationalized correlating in vitro target-oriented screening and in silico docking.The flavones apigenin, luteolin, and their respective glucosides have good ability to interact with metalloproteases and can also be lead compounds for further development. Glycones are more active on MMP-1, -3, -8, and -13 than MMP-9. Collagenases MMP-1, MMP-8, and MMP-13 are inhibited by compounds having rutinoside glycones. Apigenin and luteolin are inactive on MMP-1, -3, and -8, which can be interpreted as a better selectivity for both -9 and -13 peptidases. The more active compounds are apigenin-7-O-rutinoside on MMP-1 and luteolin-7-O-rutinoside on MMP-3. The lowest IC50 values were also found for apigenin-7-O-glucuronide, apigenin-7-O-rutinoside, and luteolin-7-O-glucuronide. The glycoside moiety might allow for a better anchoring to the active site of MMP-1, -3, -8, -9, and -13. Overall, the in silico data are substantially in agreement with the in vitro ones (fluorimetric assay).

  1. Sequestration of nanoparticles by an EPS matrix reduces the particle-specific bactericidal activity

    NASA Astrophysics Data System (ADS)

    Wang, Qian; Kang, Fuxing; Gao, Yanzheng; Mao, Xuewei; Hu, Xiaojie

    2016-02-01

    Most artificial nanomaterials are known to exhibit broad-spectrum bactericidal activity; however, the defence mechanisms that bacteria use based on extracellular polymeric substances (EPS) to detoxify nanoparticles (NPs) are not well known. We ruled out the possibility of ion-specific bactericidal activity by showing the lack of equivalent dissolved zinc and silicon toxicity and determined the particle-specific toxicity of ZnO and SiO2 nanoparticles (ZnONPs/SiO2NPs) through dialysis isolation experiments. Surprisingly, the manipulation of the E. coli EPS (i.e., no EPS manipulation or EPS removal by sonication/centrifugation) showed that their particle-specific bactericidal activity could be antagonized by NP-EPS sequestration. The survival rates of pristine E. coli (no EPS manipulation) reached 65% (ZnONPs, 500 mg L‑1) and 79% (SiO2NPs, 500 mg L‑1), whereas survival rates following EPS removal by sonication/centrifugation were 11% and 63%, respectively. Transmission electron microscopy (TEM) combined with fluorescence micro-titration analysis and Fourier-transform infrared spectroscopy (FTIR) showed that protein-like substances (N-H and C-N in amide II) and secondary carbonyl groups (C=O) in the carboxylic acids of EPS acted as important binding sites that were involved in NP sequestration. Accordingly, the amount and composition of EPS produced by bacteria have important implications for the bactericidal efficacy and potential environmental effects of NPs.

  2. Sequestration of nanoparticles by an EPS matrix reduces the particle-specific bactericidal activity

    PubMed Central

    Wang, Qian; Kang, Fuxing; Gao, Yanzheng; Mao, Xuewei; Hu, Xiaojie

    2016-01-01

    Most artificial nanomaterials are known to exhibit broad-spectrum bactericidal activity; however, the defence mechanisms that bacteria use based on extracellular polymeric substances (EPS) to detoxify nanoparticles (NPs) are not well known. We ruled out the possibility of ion-specific bactericidal activity by showing the lack of equivalent dissolved zinc and silicon toxicity and determined the particle-specific toxicity of ZnO and SiO2 nanoparticles (ZnONPs/SiO2NPs) through dialysis isolation experiments. Surprisingly, the manipulation of the E. coli EPS (i.e., no EPS manipulation or EPS removal by sonication/centrifugation) showed that their particle-specific bactericidal activity could be antagonized by NP-EPS sequestration. The survival rates of pristine E. coli (no EPS manipulation) reached 65% (ZnONPs, 500 mg L−1) and 79% (SiO2NPs, 500 mg L−1), whereas survival rates following EPS removal by sonication/centrifugation were 11% and 63%, respectively. Transmission electron microscopy (TEM) combined with fluorescence micro-titration analysis and Fourier-transform infrared spectroscopy (FTIR) showed that protein-like substances (N-H and C-N in amide II) and secondary carbonyl groups (C=O) in the carboxylic acids of EPS acted as important binding sites that were involved in NP sequestration. Accordingly, the amount and composition of EPS produced by bacteria have important implications for the bactericidal efficacy and potential environmental effects of NPs. PMID:26856606

  3. Creation of a U.S. Phosphorescent OLED Lighting Panel Manufacturing Facility

    SciTech Connect

    Hack, Michael

    2013-09-30

    Universal Display Corporation (UDC) has pioneered high efficacy phosphorescent OLED (PHOLED™) technology to enable the realization of an exciting new form of high quality, energy saving solid-date lighting. In laboratory test devices, we have demonstrated greater than 100 lm/W conversion efficacy. In this program, Universal Display will demonstrate the scalability of its proprietary UniversalPHOLED technology and materials for the manufacture of white OLED lighting panels that meet commercial lighting targets. Moser Baer Technologies will design and build a U.S.- based pilot facility. The objective of this project is to establish a pilot phosphorescent OLED (PHOLED) manufacturing line in the U.S. Our goal is that at the end of the project, prototype lighting panels could be provided to U.S. luminaire manufacturers for incorporation into products to facilitate the testing of design concepts and to gauge customer acceptance, so as to facilitate the growth of the embryonic U.S. OLED lighting industry. In addition, the team will provide a cost of ownership analysis to quantify production costs including OLED performance metrics which relate to OLED cost such as yield, materials usage, cycle time, substrate area, and capital depreciation. This project was part of a new DOE initiative designed to help establish and maintain U.S. leadership in this program will support key DOE objectives by showing a path to meet Department of Energy Solid-State Lighting Manufacturing Roadmap cost targets, as well as meeting its efficiency targets by demonstrating the energy saving potential of our technology through the realization of greater than 76 lm/W OLED lighting panels by 2012.

  4. Synthesis of derivatives of methyl rosmarinate and their inhibitory activities against matrix metalloproteinase-1 (MMP-1).

    PubMed

    Yuan, Hu; Lu, Weiqiang; Wang, Liyan; Shan, Lei; Li, Honglin; Huang, Jin; Sun, Qingyan; Zhang, Weidong

    2013-04-01

    A series of MMP-1 inhibitors have been identified based upon a methyl rosmarinate scaffold using structure-based drug design methods. The best compound in the series showed an IC50 value of 0.4 μM. A docking study was conducted for compound (S)-10n in order to investigate its binding interactions with MMP-1. The structure-activity relationships (SAR) were also briefly discussed. Useful SAR was established which provides important guidelines for the design of future generations of potent inhibitors against MMP-1.

  5. Anti-photoaging activity and inhibition of matrix metalloproteinase (MMP) by marine red alga, Corallina pilulifera methanol extract

    NASA Astrophysics Data System (ADS)

    Ryu, BoMi; Qian, Zhong-Ji; Kim, Moon-Moo; Nam, Ki Wan; Kim, Se-Kwon

    2009-02-01

    Matrix metalloproteinases (MMPs), a key component in photoaging of the skin due to exposure to ultraviolet A, appear to be increased by UV-irradiation-associated generation of reactive oxygen species (ROS). In this study, the alga Corallina pilulifera methanol (CPM) extract has been shown to exert a potent antioxidant activity and protective effect on UVA-induced oxidative stress of human dermal fibroblast (HDF) cell. Antioxidant evaluated by various antioxidant assays. These include reducing power, total antioxidant, DPPH radical scavenging, hydroxyl radical scavenging and protective effect on DNA damage caused by hydroxyl radicals generated. Further, the ROS level was detected using a fluorescence probe, 2',7'-dichlorofluorescein diacetate (DCFH-DA), which could be converted to highly fluorescent dichlorofluorescein (DCF) with the presence of intracellular ROS on HT-1080 cells. Those various antioxidant activities were compared to standard antioxidants such as α-tocopherol. In addition, the in vitro activities of MMP-2 and MMP-9 in HDF cell were inhibited by C. pilulifera methanol extract dose dependently by using gelatin zymography method. The results obtained in the present study suggested that the C. pilulifera methanol extract may be a potential source of natural anti-photoaging.

  6. SIGMAR1 Regulates Membrane Electrical Activity in Response to Extracellular Matrix Stimulation to Drive Cancer Cell Invasiveness.

    PubMed

    Crottès, David; Rapetti-Mauss, Raphael; Alcaraz-Perez, Francisca; Tichet, Mélanie; Gariano, Giuseppina; Martial, Sonia; Guizouarn, Hélène; Pellissier, Bernard; Loubat, Agnès; Popa, Alexandra; Paquet, Agnès; Presta, Marco; Tartare-Deckert, Sophie; Cayuela, Maria Luisa; Martin, Patrick; Borgese, Franck; Soriani, Olivier

    2016-02-01

    The sigma 1 receptor (Sig1R) is a stress-activated chaperone that regulates ion channels and is associated with pathologic conditions, such as stroke, neurodegenerative diseases, and addiction. Aberrant expression levels of ion channels and Sig1R have been detected in tumors and cancer cells, such as myeloid leukemia and colorectal cancer, but the link between ion channel regulation and Sig1R overexpression during malignancy has not been established. In this study, we found that Sig1R dynamically controls the membrane expression of the human voltage-dependent K(+) channel human ether-à-go-go-related gene (hERG) in myeloid leukemia and colorectal cancer cell lines. Sig1R promoted the formation of hERG/β1-integrin signaling complexes upon extracellular matrix stimulation, triggering the activation of the PI3K/AKT pathway. Consequently, the presence of Sig1R in cancer cells increased motility and VEGF secretion. In vivo, Sig1R expression enhanced the aggressiveness of tumor cells by potentiating invasion and angiogenesis, leading to poor survival. Collectively, our findings highlight a novel function for Sig1R in mediating cross-talk between cancer cells and their microenvironment, thus driving oncogenesis by shaping cellular electrical activity in response to extracellular signals. Given the involvement of ion channels in promoting several hallmarks of cancer, our study also offers a potential strategy to therapeutically target ion channel function through Sig1R inhibition.

  7. Minocycline Attenuates Neonatal Germinal-Matrix-Hemorrhage-Induced Neuroinflammation and Brain Edema by Activating Cannabinoid Receptor 2.

    PubMed

    Tang, Jun; Chen, Qianwei; Guo, Jing; Yang, Liming; Tao, Yihao; Li, Lin; Miao, Hongping; Feng, Hua; Chen, Zhi; Zhu, Gang

    2016-04-01

    Germinal matrix hemorrhage (GMH) is the most common neurological disease of premature newborns leading to detrimental neurological sequelae. Minocycline has been reported to play a key role in neurological inflammatory diseases by controlling some mechanisms that involve cannabinoid receptor 2 (CB2R). The current study investigated whether minocycline reduces neuroinflammation and protects the brain from injury in a rat model of collagenase-induced GMH by regulating CB2R activity. To test this hypothesis, the effects of minocycline and a CB2R antagonist (AM630) were evaluated in male rat pups that were post-natal day 7 (P7) after GMH. We found that minocycline can lead to increased CB2R mRNA expression and protein expression in microglia. Minocycline significantly reduced GMH-induced brain edema, microglial activation, and lateral ventricular volume. Additionally, minocycline enhanced cortical thickness after injury. All of these neuroprotective effects of minocycline were prevented by AM630. A cannabinoid CB2 agonist (JWH133) was used to strengthen the hypothesis, which showed the identical neuroprotective effects of minocycline. Our study demonstrates, for the first time, that minocycline attenuates neuroinflammation and brain injury in a rat model of GMH, and activation of CBR2 was partially involved in these processes.

  8. Optimal level activity of matrix metalloproteinases is critical for adult visual plasticity in the healthy and stroke-affected brain.

    PubMed

    Pielecka-Fortuna, Justyna; Kalogeraki, Evgenia; Fortuna, Michal G; Löwel, Siegrid

    2015-11-26

    The ability of the adult brain to undergo plastic changes is of particular interest in medicine, especially regarding recovery from injuries or improving learning and cognition. Matrix metalloproteinases (MMPs) have been associated with juvenile experience-dependent primary visual cortex (V1) plasticity, yet little is known about their role in this process in the adult V1. Activation of MMPs is a crucial step facilitating structural changes in a healthy brain; however, upon brain injury, upregulated MMPs promote the spread of a lesion and impair recovery. To clarify these seemingly opposing outcomes of MMP-activation, we examined the effects of MMP-inhibition on experience-induced plasticity in healthy and stoke-affected adult mice. In healthy animals, 7-day application of MMP-inhibitor prevented visual plasticity. Additionally, treatment with MMP-inhibitor once but not twice following stroke rescued plasticity, normally lost under these conditions. Our data imply that an optimal level of MMP-activity is crucial for adult visual plasticity to occur.

  9. Optimal level activity of matrix metalloproteinases is critical for adult visual plasticity in the healthy and stroke-affected brain

    PubMed Central

    Pielecka-Fortuna, Justyna; Kalogeraki, Evgenia; Fortuna, Michal G; Löwel, Siegrid

    2015-01-01

    The ability of the adult brain to undergo plastic changes is of particular interest in medicine, especially regarding recovery from injuries or improving learning and cognition. Matrix metalloproteinases (MMPs) have been associated with juvenile experience-dependent primary visual cortex (V1) plasticity, yet little is known about their role in this process in the adult V1. Activation of MMPs is a crucial step facilitating structural changes in a healthy brain; however, upon brain injury, upregulated MMPs promote the spread of a lesion and impair recovery. To clarify these seemingly opposing outcomes of MMP-activation, we examined the effects of MMP-inhibition on experience-induced plasticity in healthy and stoke-affected adult mice. In healthy animals, 7-day application of MMP-inhibitor prevented visual plasticity. Additionally, treatment with MMP-inhibitor once but not twice following stroke rescued plasticity, normally lost under these conditions. Our data imply that an optimal level of MMP-activity is crucial for adult visual plasticity to occur. DOI: http://dx.doi.org/10.7554/eLife.11290.001 PMID:26609811

  10. Fluid shear promotes chondrosarcoma cell invasion by activating matrix metalloproteinase 12 via IGF-2 and VEGF signaling pathways

    PubMed Central

    Wang, P; Chen, S-H; Hung, W-C; Paul, C; Zhu, F; Guan, P-P; Huso, DL; Kontrogianni-Konstantopoulos, A; Konstantopoulos, K

    2015-01-01

    Interstitial fluid flow in and around the tumor tissue is a physiologically relevant mechanical signal that regulates intracellular signaling pathways throughout the tumor. Yet, the effects of interstitial flow and associated fluid shear stress on the tumor cell function have been largely overlooked. Using in vitro bioengineering models in conjunction with molecular cell biology tools, we found that fluid shear (2 dyn/cm2) markedly upregulates matrix metalloproteinase 12 (MMP-12) expression and its activity in human chondrosarcoma cells. MMP-12 expression is induced in human chondrocytes during malignant transformation. However, the signaling pathway regulating MMP-12 expression and its potential role in human chondrosarcoma cell invasion and metastasis have yet to be delineated. We discovered that fluid shear stress induces the synthesis of insulin growth factor-2 (IGF-2) and vascular endothelial growth factor (VEGF) B and D, which in turn transactivate MMP-12 via PI3-K, p38 and JNK signaling pathways. IGF-2-, VEGF-B- or VEGF-D-stimulated chondrosarcoma cells display markedly higher migratory and invasive potentials in vitro, which are blocked by inhibiting MMP-12, PI3-K, p38 or JNK activity. Moreover, recombinant human MMP-12 or MMP-12 overexpression can potentiate chondrosarcoma cell invasion in vitro and the lung colonization in vivo. By reconstructing and delineating the signaling pathway regulating MMP-12 activation, potential therapeutic strategies that interfere with chondrosarcoma cell invasion may be identified. PMID:25435370

  11. Melatonin inhibits TPA-induced oral cancer cell migration by suppressing matrix metalloproteinase-9 activation through the histone acetylation

    PubMed Central

    Yeh, Chia-Ming; Lin, Chiao-Wen; Yang, Jia-Sin; Yang, Wei-En; Su, Shih-Chi; Yang, Shun-Fa

    2016-01-01

    Melatonin exerts antimetastatic effects on liver and breast cancer and also inhibits matrix metalloproteinase (MMP) activity. However, the detailed impacts and underlying mechanisms of melatonin on oral cancer cell metastasis are still unclear. This study showed that melatonin attenuated the 12-O-tetradecanoylphorbol-13-acetate-induced migration of oral cancer cell lines, HSC-3 and OECM-1. Zymography, quantitative real-time PCR, and Western blotting analyses revealed that melatonin lessened MMP-9 enzyme activity as well as the expression of MMP-9 mRNA and protein. Furthermore, melatonin suppressed the phosphorylation of the ERK1/2 signalling pathway, which dampened MMP-9 gene transcription by affecting the expression of transcriptional coactivators, such as CREB-binding protein (CREBBP) and E1A binding protein p300 (EP300), and decreasing histone acetylation in HSC-3 and OECM-1 cells. Examinations on clinical samples exhibited that MMP-9, CREBBP, and EP300 were significantly increased in oral cancer tissues. Moreover, the relative level of CREBBP was positively correlated with the expression of MMP-9 and EP300. In conclusion, we demonstrated that melatonin inhibits the motility of HSC-3 and OECM-1 cells in vitro through a molecular mechanism that involves attenuation of MMP-9 expression and activity mediated by decreased histone acetylation. PMID:26980735

  12. Structure activity relationship of antioxidative property of flavonoids and inhibitory effect on matrix metalloproteinase activity in UVA-irradiated human dermal fibroblast.

    PubMed

    Sim, Gwan-Sub; Lee, Bum-Chun; Cho, Ho Seung; Lee, Jae Woong; Kim, Jin-Hwa; Lee, Dong-Hwan; Kim, Jin-Hui; Pyo, Hyeong-Bae; Moon, Dong Cheul; Oh, Ki-Wan; Yun, Yeo Pyo; Hong, Jin Tae

    2007-03-01

    Collagenase, a matrix metalloproteinases (MMPs), is a key regulator in the photoaging process of skin due to the reactive oxygen species generated after exposure to ultraviolet A (UVA). Flavonoid compounds have been demonstrated to possess antioxidant properties, and could be useful in the prevention of photoaging. In this study, to investigate the structure-activity relationship of flavonoid compounds on their antioxidant property and inhibitory effects against the MMP activity, the effects of several flavonoids; myricetin, quercetin, kaempferol, luteolin, apigenin and chrysin, on the reactive oxygen species scavengering activity and inhibitory effect against the MMP activity were examined in vitro and in human dermal fibroblasts induced by UVA. The relative order of antioxidative efficacy, as determined using the 1, 1-diphenyl-2-picrylhydrazyl (DPPH) method and the xanthine/xanthine oxidase system, was as follows; flavones: luteolin > apigenin > chrysin, flavonols: myricetin > quercetin > kaempferol, and correlated with the respective number of OH group on their B-ring. In good correlation with the antioxidant properties, the flavonoids inhibited the collagenase activities, in a dose-dependent manner, and the MMP expression. These results suggested the UVA induced antioxidative activity and inhibitory effects of flavonoids on the collagenase in human dermal fibroblasts depends on the number of OH group in the flavonoid structure, and those with a higher number of OH group may be more useful in the prevention of UV stressed skin aging.

  13. Iron sensitizes keratinocytes and fibroblasts to UVA-mediated matrix metalloproteinase-1 through TNF-α and ERK activation.

    PubMed

    Jian, Jinlong; Pelle, Edward; Yang, Qing; Pernodet, Nadine; Maes, Daniel; Huang, Xi

    2011-03-01

    Oestrogen deficiency is regarded as the main causative factor in postmenopausal skin ageing and photoageing. While women after menopause experience low levels of oestrogen because of cease of ovarian function, they are also exposed to high levels of iron as a result of cessation of menstruation. In this study, we investigated whether this increase in iron presents a risk to the postmenopausal skin. Because of the lack of appropriate animal models to closely mimic the low oestrogen and high iron conditions, we tested the hypothesis in a high iron and low oestrogen culture model. Here, we showed that primary human dermal fibroblasts exposed to iron did not affect the baseline levels of matrix metalloproteinase-1 (MMP-1) activity. However, the iron-exposed fibroblasts were sensitized to UVA exposure, which resulted in a synergistic increase in MMP-1. UVA activated the three members of MAPK family: ERKs, p38, and JNKs. Additional activation of ERKs by iron contributed to the synergistic increases. Primary normal human epidermal keratinocytes (NHEK) did not respond to iron or UVA exposure as measured by MMP-1, but produced tumor necrosis factor-alpha (TNF-α) in the media, which then stimulated MMP-1 in fibroblasts. Our results indicate that iron and UVA increase MMP-1 activity in dermal fibroblasts not only directly through ERK activation but also by an indirect paracrine loop through TNF-α released by NHEK. We conclude that in addition to oestrogen deficiency, increased iron as a result of menopause could be a novel risk factor by sensitizing postmenopausal skin to solar irradiation.

  14. Cleavage of extracellular matrix in periodontitis: gingipains differentially affect cell adhesion activities of fibronectin and tenascin-C

    PubMed Central

    Ruggiero, Sabrina; Cosgarea, Raluca; Potempa, Jan; Potempa, Barbara; Eick, Sigrun; Chiquet, Matthias

    2014-01-01

    Gingipains are cysteine proteases that represent major virulence factors of the periodontopathogenic bacterium Porphyromonas gingivalis. Gingipains are reported to degrade extracellular matrix (ECM) of periodontal tissues, leading to tissue destruction and apoptosis. The exact mechanism is not known, however. Fibronectin and tenascin-C are pericellular ECM glycoproteins present in periodontal tissues. Whereas fibronectin mediates fibroblast adhesion, tenascin-C binds to fibronectin and inhibits its cell-spreading activity. Using purified proteins in vitro, we asked whether fibronectin and tenascin-C are cleaved by gingipains at clinically relevant concentrations, and how fragmentation by the bacterial proteases affects their biological activity in cell adhesion. Fibronectin was cleaved into distinct fragments by all three gingipains; however, only arginine-specific HRgpA and RgpB but not lysine-specific Kgp destroyed its cell-spreading activity. This result was confirmed with recombinant cell-binding domain of fibronectin. Of the two major tenascin-C splice variants, the large but not the small was a substrate for gingipains, indicating that cleavage occurred primarily in the alternatively spliced domain. Surprisingly, cleavage of large tenascin-C variant by all three gingipains generated fragments with increased anti-adhesive activity towards intact fibronectin. Fibronectin and tenascin-C fragments were detected in gingival crevicular fluid of a subset of periodontitis patients. We conclude that cleavage by gingipains directly affects the biological activity of both fibronectin and tenascin-C in a manner that might lead to increased cell detachment and loss during periodontal disease. PMID:23313574

  15. Iron sensitizes keratinocytes and fibroblasts to UVA-mediated matrix metalloproteinase-1 through TNF-α and ERK activation

    PubMed Central

    Jian, Jinlong; Pelle, Edward; Yang, Qing; Pernodet, Nadine; Maes, Daniel; Huang, Xi

    2010-01-01

    Oestrogen deficiency is regarded as the main causative factor in postmenopausal skin ageing and photoageing. While women after menopause experience low levels of oestrogen because of cease of ovarian function, they are also exposed to high levels of iron as a result of cessation of menstruation. In this study, we investigated whether this increase in iron presents a risk to the postmenopausal skin. Because of the lack of appropriate animal models to closely mimic the low oestrogen and high iron conditions, we tested the hypothesis in a high iron and low oestrogen culture model. Here, we showed that primary human dermal fibroblasts exposed to iron did not affect the baseline levels of matrix metalloproteinase-1 (MMP-1) activity. However, the iron-exposed fibroblasts were sensitized to UVA exposure, which resulted in a synergistic increase in MMP-1. UVA activated the three members of MAPK family: ERKs, p38, and JNKs. Additional activation of ERKs by iron contributed to the synergistic increases. Primary normal human epidermal keratinocytes (NHEK) did not respond to iron or UVA exposure as measured by MMP-1, but produced tumor necrosis factor-alpha (TNF-α) in the media, which then stimulated MMP-1 in fibroblasts. Our results indicate that iron and UVA increase MMP-1 activity in dermal fibroblasts not only directly through ERK activation but also by an indirect paracrine loop through TNF-α released by NHEK. We conclude that in addition to oestrogen deficiency, increased iron as a result of menopause could be a novel risk factor by sensitizing postmenopausal skin to solar irradiation. PMID:20701626

  16. Application of Developed APCVD Transparent Conducting Oxides and Undercoat Technologies for Economical OLED Lighting

    SciTech Connect

    Martin Bluhm; James Coffey; Roman Korotkov; Craig Polsz; Alexandre Salemi; Robert Smith; Ryan Smith; Jeff Stricker; Chen Xu; Jasmine Shirazi; George Papakonstantopulous; Steve Carson; Claudia Goldman; Soren Hartmann; Frank Jessen; Bianca Krogmann; Christoph Rickers; Manfred Ruske; Holger Schwab; Dietrich Bertram

    2011-01-02

    Economics is a key factor for application of organic light emitting diodes (OLED) in general lighting relative to OLED flat panel displays that can handle high cost materials such as indium tin oxide (ITO) or Indium zinc oxide (IZO) as the transparent conducting oxide (TCO) on display glass. However, for OLED lighting to penetrate into general illumination, economics and sustainable materials are critical. The issues with ITO have been documented at the DOE SSL R&D and Manufacturing workshops for the last 5 years and the issue is being exacerbated by export controls from China (one of the major sources of elemental indium). Therefore, ITO is not sustainable because of the fluctuating costs and the United States (US) dependency on other nations such as China. Numerous alternatives to ITO/IZO are being evaluated such as Ag nanoparticles/nanowires, carbon nanotubes, graphene, and other metal oxides. Of these other metal oxides, doped zinc oxide has attracted a lot of attention over the last 10 years. The volume of zinc mined is a factor of 80,000 greater than indium and the US has significant volumes of zinc mined domestically, resulting in the ability for the US to be self-sufficient for this element that can be used in optoelectronic applications. The costs of elemental zinc is over 2 orders of magnitude less than indium, reflecting the relative abundance and availability of the elements. Arkema Inc. and an international primary glass manufacturing company, which is located in the United States, have developed doped zinc oxide technology for solar control windows. The genesis of this DOE SSL project was to determine if doped zinc oxide technology can be taken from the commodity based window market and translate the technology to OLED lighting. Thus, Arkema Inc. sought out experts, Philips Lighting, Pacific Northwest National Laboratories (PNNL) and National Renewable Research Laboratories (NREL), in OLED devices and brought them into the project. This project had a

  17. Tunable white light emission in Parallel Tandem OLEDs made with silver metal as interlayer

    NASA Astrophysics Data System (ADS)

    Oliva, Jorge; Papadimitratos, Alexios; Zakhidov, Anvar; UT Dallas Team

    Parallel tandem organic light emitting diodes (OLEDs) which consisted in a top and bottom subunits, and joined with a thin layer of silver (interlayer) were fabricated. In this parallel tandem architecture the Ag metal is an active common anode, which permitted to inject holes into top and bottom subunits. Both subunits of the tandem can thus be connected functionally in a new geometry and addressed separately. Those Tandems had a yellow emitter (a mixture of MEH-PPV and TFB polymers) in the bottom subunit and a blue emitting molecule in the top subunit. The simultaneous combination of the emitted yellow and blue light when both subunits are operating produced white light. We could tune the white light from cool (CIE: 0.33, 0.25) to warm (CIE: 0.38, 0.39) by changing the intensity of the yellow light, that in turn depends on the ratio of MEH-PPV/TFB mixture used to make the emitting layer in the bottom subunit. We also compared the performance of the parallel tandem with these in series and we found additional advantages of the parallel architecture over the configuration for the series tandems such as: tunable chromaticity, lower turn on voltage (4V compared to 7V in the in-series tandem) and higher brightness. The best CIE coordinate we obtained for white light was (0.35, 0.35) which is near the ideal coordinate of (0.33,0.33).

  18. Reactivity and activation of dioxygen-derived species in aprotic media (a model matrix for biomembranes).

    PubMed

    Sawyer, D T; Roberts, J L; Calderwood, T S; Sugimoto, H; McDowell, M S

    1985-12-17

    In aprotic media the electrochemical reduction of dioxygen yields superoxide ion (O2-), which is an effective Brønsted base, nucleophile, one-electron reductant, and one-electron oxidant of reduced transition metal ions. With electrophilic substrates (organic halides and carbonyl carbons) O2- displaces a leaving group to form a peroxy radical (ROO.) in the primary process. Superoxide ion oxidizes the activated hydrogen atoms of ascorbic acid, catechols, hydrophenazines and hydroflavins. Combination of O2- with 1,2-diphenylhydrazine yields the anion radical of azobenzene, which reacts with O2 to give azobenzene and O2- (an example of O2--induced autoxidation). With phenylhydrazine, O2- produces phenyl radicals. The in situ formation of HO2. (O2- plus a proton source) results in H-atom abstraction from allylic and other groups with weak heteroatom--H bonds (binding energy (b.e.) less than 335 kJ). This is a competitive process with the facile second-order disproportionation of HO2. to H2O2 and O2 (kbi approximately equal to 10(4) mol-1 s-1 in Me2SO). Addition of [FeII(MeCN)4] (ClO4)2 to solutions of hydrogen peroxide in dry acetonitrile catalyses a rapid disproportionation of H2O2 via the initial formation of an adduct [FeII(H2O2)2+----Fe(O)(H2O)2+], which oxidizes a second H2O2 to oxygen. In the presence of organic substrates such as 1,4-cyclohexadiene, 1,2-diphenylhydrazine, catechols and thiols the FeII-H2O2/MeCN system yields dehydrogenated products; with alcohols, aldehydes, methylstyrene, thioethers, sulphoxides, and phosphines, the FeII(H2O2)2+ adduct promotes their monoxygenation. The product from the FeO2+-H2O2 reaction, [FeII(H2O2)22+], exhibits chemistry that is closely similar to that for singlet oxygen (1O2), which has been confirmed by the stoichiometric dioxygenation of diphenylisobenzofuran, 9,10-diphenylanthracene, rubrene and electron-rich unsaturated carbon-carbon bonds (Ph2C = CPh2, PhC = CPh and cis-PhCH = CHPh). In dry ligand-free acetonitrile

  19. Transcript-activated collagen matrix as sustained mRNA delivery system for bone regeneration.

    PubMed

    Badieyan, Zohreh Sadat; Berezhanskyy, Taras; Utzinger, Maximilian; Aneja, Manish Kumar; Emrich, Daniela; Erben, Reinhold; Schüler, Christiane; Altpeter, Philipp; Ferizi, Mehrije; Hasenpusch, Günther; Rudolph, Carsten; Plank, Christian

    2016-10-10

    Transcript therapies using chemically modified messenger RNAs (cmRNAs) are emerging as safe and promising alternatives for gene and recombinant protein therapies. However, their applications have been limited due to transient translation and relatively low stability of cmRNAs compared to DNA. Here we show that vacuum-dried cmRNA-loaded collagen sponges, termed transcript activated matrices (TAMs), can serve as depots for sustained delivery of cmRNA. TAMs provide steady state protein production for up to six days, and substantial residual expression until 11days post transfection. Another advantage of this technology was nearly 100% transfection efficiency as well as low toxicity in vitro. TAMs were stable for at least 6months at room temperature. Human BMP-2-encoding TAMs induced osteogenic differentiation of MC3T3-E1 cells in vitro and bone regeneration in a non-critical rat femoral bone defect model in vivo. In summary, TAMs are a promising tool for bone regeneration and potentially also for other applications in regenerative medicine and tissue engineering.

  20. Applications of snake venom components to modulate integrin activities in cell-matrix interactions

    PubMed Central

    Marcinkiewicz, Cezary

    2013-01-01

    Snake venom proteins are broadly investigated in the different areas of life science. Direct interaction of these compounds with cells may involve a variety of mechanisms that result in diverse cellular responses leading to the activation or blocking of physiological functions of the cell. In this review, the snake venom components interacting with integrins will be characterized in context of their effect on cellular response. Currently, two major families of snake venom proteins are considered as integrin-binding molecules. The most attention has been devoted to the disintegrin family, which binds certain types of integrins through specific motifs recognized as a tri-peptide structurally localized on an integrin-binding loop. Other snake venom integrin-binding proteins belong to the C-type lectin family. Snake venom molecules bind to the cellular integrins resulting in a modulation of cell signaling and in consequence, the regulation of cell proliferation, migration and apoptosis. Therefore, snake venom research on the integrin-binding molecules may have significance in biomedicine and basic cell biology. PMID:23811033

  1. Olive cultivar origin is a major cause of polymorphism for Ole e 1 pollen allergen

    PubMed Central

    Hamman-Khalifa, AbdelMounim; Castro, Antonio Jesús; Jiménez-López, José Carlos; Rodríguez-García, María Isabel; Alché, Juan de Dios

    2008-01-01

    Background Pollens from different olive (Olea europaea L.) cultivars have been shown to differ significantly in their content in Ole e 1 and in their overall allergenicity. This allergen is, in addition, characterized by a high degree of polymorphism in its sequence. The purpose of this study is to evaluate the putative presence of divergences in Ole e 1 sequences from different olive cultivars. Results RNA from pollen individually collected from 10 olive cultivars was used to amplify Ole e 1 sequences by RT-PCR, and the sequences were analyzed by using different bioinformatics tools. Numerous nucleotide substitutions were detected throughout the sequences, many of which resulted in amino acid substitutions in the deduced protein sequences. In most cases variability within a single variety was much lower than among varieties. Key amino acid changes in comparison with "canonical" sequences previously described in the literature included: a) the substitution of C19-relevant to the disulphide bond structure of the protein-, b) the presence of an additional N-glycosylation motif, and c) point substitutions affecting regions of Ole e 1 already described like relevant for the immunogenicity/allergenicity of the protein. Conclusion Varietal origin of olive pollen is a major factor determining the diversity of Ole e 1 variants. We consider this information of capital importance for the optimal design of efficient and safe allergen formulations, and useful for the genetic engineering of modified forms of the allergen among other applications. PMID:18218146

  2. Efficient, inkjet-printed TADF-OLEDs with an ultra-soluble NHetPHOS complex

    NASA Astrophysics Data System (ADS)

    Verma, Anand; Zink, Daniel M.; Fléchon, Charlotte; Leganés Carballo, Jaime; Flügge, Harald; Navarro, José M.; Baumann, Thomas; Volz, Daniel

    2016-03-01

    Using printed organic light-emitting diodes (OLEDs) for lighting, smart-packaging and other mass-market applications has remained a dream since the first working OLED devices were demonstrated in the late 1980s. The realization of this long-term goal is hindered by the very low abundance of iridium and problems when using low-cost wet chemical production processes. Abundant, solution-processable Cu(I) complexes promise to lower the cost of OLEDs. A new copper iodide NHetPHOS emitter was prepared and characterized in solid state with photoluminescence spectroscopy and UV photoelectron spectroscopy under ambient conditions. The photoluminescence quantum efficiency was determined as 92 ± 5 % in a thin film with yellowish-green emission centered around 550 nm. This puts the material on par with the most efficient copper complexes known so far. The new compound showed superior solubility in non-polar solvents, which allowed for the fabrication of an inkjet-printed OLED device from a decalin-based ink formulation. The emission layer could be processed under ambient conditions and was annealed under air. In a very simple stack architecture, efficiency values up to 45 cd A-1 corresponding to 13.9 ± 1.9 % EQE were achieved. These promising results open the door to printed, large-scale OLED devices with abundant copper emitters.

  3. FDTD analysis of the light extraction efficiency of OLEDs with a random scattering layer.

    PubMed

    Kim, Jun-Whee; Jang, Ji-Hyang; Oh, Min-Cheol; Shin, Jin-Wook; Cho, Doo-Hee; Moon, Jae-Hyun; Lee, Jeong-Ik

    2014-01-13

    The light extraction efficiency of OLEDs with a nano-sized random scattering layer (RSL-OLEDs) was analyzed using the Finite Difference Time Domain (FDTD) method. In contrast to periodic diffraction patterns, the presence of an RSL suppresses the spectral shift with respect to the viewing angle. For FDTD simulation of RSL-OLEDs, a planar light source with a certain spatial and temporal coherence was incorporated, and the light extraction efficiency with respect to the fill factor of the RSL and the absorption coefficient of the material was investigated. The design results were compared to the experimental results of the RSL-OLEDs in order to confirm the usefulness of FDTD in predicting experimental results. According to our FDTD simulations, the light confined within the ITO-organic waveguide was quickly absorbed, and the absorption coefficients of ITO and RSL materials should be reduced in order to obtain significant improvement in the external quantum efficiency (EQE). When the extinction coefficient of ITO was 0.01, the EQE in the RSL-OLED was simulated to be enhanced by a factor of 1.8.

  4. Organic Light-Emitting Diodes (OLEDs) and Optically-Detected Magnetic Resonance (ODMR) studies on organic materials

    NASA Astrophysics Data System (ADS)

    Cai, Min

    Organic semiconductors have evolved rapidly over the last decades and currently are considered as the next-generation technology for many applications, such as organic light-emitting diodes (OLEDs) in flat-panel displays (FPDs) and solid state lighting (SSL), and organic solar cells (OSCs) in clean renewable energy. This dissertation focuses mainly on OLEDs. Although the commercialization of the OLED technology in FPDs is growing and appears to be just around the corner for SSL, there are still several key issues that need to be addressed: (1) the cost of OLEDs is very high, largely due to the costly current manufacturing process; (2) the efficiency of OLEDs needs to be improved. This is vital to the success of OLEDs in the FPD and SSL industries; (3) the lifetime of OLEDs, especially blue OLEDs, is the biggest technical challenge. All these issues raise the demand for new organic materials, new device structures, and continued lower-cost fabrication methods. In an attempt to address these issues, we used solution-processing methods to fabricate highly efficient small molecule OLEDs (SMOLEDs); this approach is cost-effective in comparison to the more common thermal vacuum evaporation. We also successfully made efficient indium tin oxide (ITO)-free SMOLEDs to further improve the efficiency of the OLEDs. We employed the spin-dependent optically-detected magnetic resonance (ODMR) technique to study the luminescence quenching processes in OLEDs and organic materials in order to understand the intrinsic degradation mechanisms. We also fabricated polymer LEDs (PLEDs) based on a new electron-accepting blue-emitting polymer and studied the effect of molecular weight on the efficiency of PLEDs. All these studies helped us to better understand the underlying relationship between the organic semiconductor materials and the OLEDs' performance, and will subsequently assist in further enhancing the efficiency of OLEDs. With strongly improved device performance (in addition to

  5. Matrix metalloproteinase-1 inhibitory activities of Morinda citrifolia seed extract and its constituents in UVA-irradiated human dermal fibroblasts.

    PubMed

    Masuda, Megumi; Murata, Kazuya; Naruto, Shunsuke; Uwaya, Akemi; Isami, Fumiyuki; Matsuda, Hideaki

    2012-01-01

    The objective of this study was to examine whether a 50% ethanolic extract (MCS-ext) of the seeds of Morinda citrifolia (noni) and its constituents have matrix metalloproteinase-1 (MMP-1) inhibitory activity in UVA-irradiated normal human dermal fibroblasts (NHDFs). The MCS-ext (10 μg/mL) inhibited MMP-1 secretion from UVA-irradiated NHDFs, without cytotoxic effects, at 48 h after UV exposure. The ethyl acetate-soluble fraction of MCS-ext was the most potent inhibitor of MMP-1 secretion. Among the constituents of the fraction, a lignan, 3,3'-bisdemethylpinoresinol (1), inhibited the MMP-1 secretion at a concentration of 0.3 μM without cytotoxic effects. Furthermore, 1 (0.3 μM) reduced the level of intracellular MMP-1 expression. Other constituents, namely americanin A (2), quercetin (3) and ursolic acid (4), were inactive. To elucidate inhibition mechanisms of MMP-1 expression and secretion, the effect of 1 on mitogen-activated protein kinases (MAPKs) phosphorylation was examined. Western blot analysis revealed that 1 (0.3 μM) reduced the phosphorylations of p38 and c-Jun-N-terminal kinase (JNK). These results suggested that 1 suppresses intracellular MMP-1 expression, and consequent secretion from UVA-irradiated NHDFs, by down-regulation of MAPKs phosphorylation.

  6. Environmental Topology and Water Availability Modulates the Catalytic Activity of β-Galactosidase Entrapped in a Nanosporous Silicate Matrix

    PubMed Central

    Burgos, M. Ines; Velasco, Manuel I.; Acosta, Rodolfo H.; Perillo, María A.

    2016-01-01

    In the present work we studied the catalytic activity of E. coli β-Gal confined in a nanoporous silicate matrix (Eβ-Gal) at different times after the beginning of the sol-gel polymerization process. Enzyme kinetic experiments with two substrates (ONPG and PNPG) that differed in the rate-limiting steps of the reaction mechanism for their β-Gal-catalyzed hydrolysis, measurements of transverse relaxation times (T2) of water protons through 1H-NMR, and scanning electron microscopy analysis of the gel nanostructure, were performed. In conjunction, results provided evidence that water availability is crucial for the modulation observed in the catalytic activity of β-Gal as long as water participate in the rate limiting step of the reaction (only with ONPG). In this case, a biphasic rate vs. substrate concentration was obtained exhibiting one phase with catalytic rate constant (kcA), similar to that observed in solution, and another phase with a higher and aging-dependent catalytic rate constant (kcB). More structured water populations (lower T2) correlates with higher catalytic rate constants (kcB). The T2-kcB negative correlation observed along the aging of gels within the 15-days period assayed reinforces the coupling between water structure and the hydrolysis catalysis inside gels. PMID:27811995

  7. Environmental Topology and Water Availability Modulates the Catalytic Activity of β-Galactosidase Entrapped in a Nanosporous Silicate Matrix.

    PubMed

    Burgos, M Ines; Velasco, Manuel I; Acosta, Rodolfo H; Perillo, María A

    2016-11-04

    In the present work we studied the catalytic activity of E. coli β-Gal confined in a nanoporous silicate matrix (Eβ-Gal) at different times after the beginning of the sol-gel polymerization process. Enzyme kinetic experiments with two substrates (ONPG and PNPG) that differed in the rate-limiting steps of the reaction mechanism for their β-Gal-catalyzed hydrolysis, measurements of transverse relaxation times (T2) of water protons through (1)H-NMR, and scanning electron microscopy analysis of the gel nanostructure, were performed. In conjunction, results provided evidence that water availability is crucial for the modulation observed in the catalytic activity of β-Gal as long as water participate in the rate limiting step of the reaction (only with ONPG). In this case, a biphasic rate vs. substrate concentration was obtained exhibiting one phase with catalytic rate constant (kcA), similar to that observed in solution, and another phase with a higher and aging-dependent catalytic rate constant (kcB). More structured water populations (lower T2) correlates with higher catalytic rate constants (kcB). The T2-kcB negative correlation observed along the aging of gels within the 15-days period assayed reinforces the coupling between water structure and the hydrolysis catalysis inside gels.

  8. Inhibition of Histone Deacetylase Activity in Human Endometrial Stromal Cells Promotes Extracellular Matrix Remodelling and Limits Embryo Invasion

    PubMed Central

    Atkinson, Stuart P.; Quiñonero, Alicia; Martínez, Sebastián; Pellicer, Antonio; Simón, Carlos

    2012-01-01

    Invasion of the trophoblast into the maternal decidua is regulated by both the trophoectoderm and the endometrial stroma, and entails the action of tissue remodeling enzymes. Trophoblast invasion requires the action of metalloproteinases (MMPs) to degrade extracellular matrix (ECM) proteins and in turn, decidual cells express tissue inhibitors of MMPs (TIMPs). The balance between these promoting and restraining factors is a key event for the successful outcome of pregnancy. Gene expression is post-transcriptionally regulated by histone deacetylases (HDACs) that unpacks condensed chromatin activating gene expression. In this study we analyze the effect of histone acetylation on the expression of tissue remodeling enzymes and activity of human endometrial stromal cells (hESCs) related to trophoblast invasion control. Treatment of hESCs with the HDAC inhibitor trichostatin A (TSA) increased the expression of TIMP-1 and TIMP-3 while decreased MMP-2, MMP-9 and uPA and have an inhibitory effect on trophoblast invasion. Moreover, histone acetylation is detected at the promoters of TIMP-1 and TIMP-3 genes in TSA-treated. In addition, in an in vitro decidualized hESCs model, the increase of TIMP-1 and TIMP-3 expression is associated with histone acetylation at the promoters of these genes. Our results demonstrate that histone acetylation disrupt the balance of ECM modulators provoking a restrain of trophoblast invasion. These findings are important as an epigenetic mechanism that can be used to control trophoblast invasion. PMID:22291969

  9. Extracellular Vesicle-functionalized Decalcified Bone Matrix Scaffolds with Enhanced Pro-angiogenic and Pro-bone Regeneration Activities

    PubMed Central

    Xie, Hui; Wang, Zhenxing; Zhang, Liming; Lei, Qian; Zhao, Aiqi; Wang, Hongxiang; Li, Qiubai; Cao, Yilin; Jie Zhang, Wen; Chen, Zhichao

    2017-01-01

    Vascularization is crucial for bone regeneration after the transplantation of tissue-engineered bone grafts in the clinical setting. Growing evidence suggests that mesenchymal stem cell (MSC)-derived extracellular vesicles (EVs) are potently pro-angiogenic both in vitro and in vivo. In the current study, we fabricated a novel EV-functionalized scaffold with enhanced pro-angiogenic and pro-bone regeneration activities by coating decalcified bone matrix (DBM) with MSC-derived EVs. EVs were harvested from rat bone marrow-derived MSCs and the pro-angiogenic potential of EVs was investigated in vitro. DBM scaffolds were then coated with EVs, and the modification was verified by scanning electron microscopy and confocal microscopy. Next, the pro-angiogenic and pro-bone regeneration activities of EV-modified scaffolds were evaluated in a subcutaneous bone formation model in nude mice. Micro-computed tomography scanning analysis showed that EV-modified scaffolds with seeded cells enhanced bone formation. Enhanced bone formation was confirmed by histological analysis. Immunohistochemical staining for CD31 proved that EV-modified scaffolds promoted vascularization in the grafts, thereby enhancing bone regeneration. This novel scaffold modification method provides a promising way to promote vascularization, which is essential for bone tissue engineering. PMID:28367979

  10. Inhibition of matrix metalloproteinase activities and tightening of tight junctions by diallyl disulfide in AGS human gastric carcinoma cells.

    PubMed

    Park, Hyun Soo; Kim, Gi-Young; Choi, Il-Whan; Kim, Nam Deuk; Hwang, Hye Jin; Choi, Young-Whan; Choi, Yung Hyun

    2011-05-01

    The effect of diallyl disulfide (DADS), a major component of an oil-soluble allyl sulfide garlic (Allium sativum) derivative, on the correlation between anti-invasive activity and tightening of tight junctions (TJs) was investigated in human gastric adenocarcinoma AGS cells. Our data indicated that the inhibitory effects of DADS on cell motility and invasiveness were found to be associated with increased tightness of the TJs, which was demonstrated by an increase in transepithelial electrical resistance. Activities of matrix metalloprotease (MMP)-2 and -9 in AGS cells were dose-dependently inhibited by treatment with DADS, and this was also correlated with a decrease in expression of their mRNA and proteins; however, tissue inhibitor of metalloproteinase (TIMP)-1 and -2 mRNA levels and proteins were increased. Additionally, immunoblotting results indicated that DADS repressed the levels of claudin proteins (claudin-2, -3, and -4), major components of TJs that play key roles in control and selectivity of paracellular transport. Although further studies are needed, these results suggest that DADS treatment may inhibit tumor cell motility and invasion and, therefore, act as a dietary source to decrease the risk of cancer metastasis.

  11. Mechanical Strain Induced Expression of Matrix Metalloproteinase-9 via Stretch-Activated Channels in Rat Abdominal Aortic Dissection

    PubMed Central

    Qiu, ZhiHuang; Chen, LiangWan; Cao, Hua; Chen, Qiang; Peng, Hua

    2017-01-01

    Background The aim of the study was to investigate the expression of matrix metalloproteinase-9 (MMP-9) in rat abdominal aortic dissection (AD) induced by mechanical strain, so as to offer a better understanding of the possible mechanisms of AD. Material/Methods Experimental AD in rats was achieved by the injection of porcine pancreatic elastase. At days 0, 1, 3, 5, 7, 14, 21, and 30 after the establishment of AD model, serum MMP-9 levels were measured by enzyme-linked immunosorbent assay (ELISA). Four groups of vascular rings were stretched in vitro with a mechanical strength of 0 g, 1 g, 3 g, or 5 g for 30 min. Another four groups were pretreated with GdCl3, streptomycin, SN50, and SN50M, followed by stretching with 3 g for 30 min. The messenger RNA and the protein of MMP-9 were analyzed by real-time RT-PCR and Western blotting, and NF-κB p65 was detected by ELISA. Results After the establishment of rat abdominal AD model, the serum MMP-9 levels of AD groups increased significantly. The results showed increased expression of MMP-9 in rat AD vessels stretched with mechanical strength of 1 g, 3 g, and 5 g, but this effect was mostly blocked by Gd Cl3 and streptomycin. The NF-κB activity in aortic rings was activated by stretching with a mechanical strength of 3 g and was blocked by SN50, but not by SN50M. Conclusions The expression of MMP-9 in serum was increased significantly after rat abdominal AD formation. Mechanical strain induced MMP-9 expression in AD vessels, which was mediated through the activation of the stretch-activated channel-induced NF-κB pathway. PMID:28286334

  12. Discoidin Domain Receptor 2 Mediates Collagen-Induced Activation of Membrane-Type 1 Matrix Metalloproteinase in Human Fibroblasts.

    PubMed

    Majkowska, Iwona; Shitomi, Yasuyuki; Ito, Noriko; Gray, Nathanael S; Itoh, Yoshifumi

    2017-03-07

    Membrane-Type 1 Matrix Metalloproteinase (MT1-MMP) is a membrane-bound MMP that is highly expressed in cells with invading capacity including fibroblasts and invasive cancer cell. A potential physiological stimulus for MT1-MMP expression is fibrillar collagen, and it has been shown that it upregulates both MT1-MMP gene and functions in various cell types. However, the mechanisms of collagen-mediated MT1-MMP activation is not clearly understood. In this study we identified discoidin domain receptor 2 (DDR2) as a crucial receptor that mediates this process in human fibroblasts. Knocking down DDR2, but not β1 integrin subunit, a common subunit for all collagen-binding integrins, inhibited collagen-induced activation of proMMP-2 and upregulation of MT1-MMP at the gene and protein level. Interestingly DDR2 knockdown or pharmacological inhibition of DDR2 also inhibited MT1-MMP-dependent cellular degradation of collagen film, suggesting that cell surface collagen degradation by MT1-MMP involves DDR2-mediated collagen signalling. This DDR2-mediated mechanism is only present in non-transformed mesenchymal cells, as collagen-induced MT1-MMP activation in HT1080 fibrosarcoma cells and MT1-MMP function in MDA-MB231 breast cancer cells were not affected by DDR kinase inhibition. DDR2 activation was found to be noticeably more effective when cells were stimulated by collagen without non-helical telopeptides region compared to intact collagen fibrils. Those data suggest that DDR2 is a microenvironmental sensor that regulates fibroblasts migration in collagen-rich environment.

  13. Fluid Shear Stress Regulates the Invasive Potential of Glioma Cells via Modulation of Migratory Activity and Matrix Metalloproteinase Expression

    PubMed Central

    Qazi, Henry; Shi, Zhong-Dong; Tarbell, John M.

    2011-01-01

    Background Glioma cells are exposed to elevated interstitial fluid flow during the onset of angiogenesis, at the tumor periphery while invading normal parenchyma, within white matter tracts, and during vascular normalization therapy. Glioma cell lines that have been exposed to fluid flow forces in vivo have much lower invasive potentials than in vitro cell motility assays without flow would indicate. Methodology/Principal Findings A 3D Modified Boyden chamber (Darcy flow through collagen/cell suspension) model was designed to mimic the fluid dynamic microenvironment to study the effects of fluid shear stress on the migratory activity of glioma cells. Novel methods for gel compaction and isolation of chemotactic migration from flow stimulation were utilized for three glioma cell lines: U87, CNS-1, and U251. All physiologic levels of fluid shear stress suppressed the migratory activity of U87 and CNS-1 cell lines. U251 motility remained unaltered within the 3D interstitial flow model. Matrix Metalloproteinase (MMP) inhibition experiments and assays demonstrated that the glioma cells depended on MMP activity to invade, and suppression in motility correlated with downregulation of MMP-1 and MMP-2 levels. This was confirmed by RT-PCR and with the aid of MMP-1 and MMP-2 shRNA constructs. Conclusions/Significance Fluid shear stress in the tumor microenvironment may explain reduced glioma invasion through modulation of cell motility and MMP levels. The flow-induced migration trends were consistent with reported invasive potentials of implanted gliomas. The models developed for this study imply that flow-modulated motility involves mechanotransduction of fluid shear stress affecting MMP activation and expression. These models should be useful for the continued study of interstitial flow effects on processes that affect tumor progression. PMID:21637818

  14. Hybrid matrix amplifier

    DOEpatents

    Martens, J.S.; Hietala, V.M.; Plut, T.A.

    1995-01-03

    The present invention comprises a novel matrix amplifier. The matrix amplifier includes an active superconducting power divider (ASPD) having N output ports; N distributed amplifiers each operatively connected to one of the N output ports of the ASPD; and a power combiner having N input ports each operatively connected to one of the N distributed amplifiers. The distributed amplifier can included M stages of amplification by cascading superconducting active devices. The power combiner can include N active elements. The resulting (N[times]M) matrix amplifier can produce signals of high output power, large bandwidth, and low noise. 6 figures.

  15. Hybrid matrix amplifier

    DOEpatents

    Martens, Jon S.; Hietala, Vincent M.; Plut, Thomas A.

    1995-01-01

    The present invention comprises a novel matrix amplifier. The matrix amplifier includes an active superconducting power divider (ASPD) having N output ports; N distributed amplifiers each operatively connected to one of the N output ports of the ASPD; and a power combiner having N input ports each operatively connected to one of the N distributed amplifiers. The distributed amplifier can included M stages of amplification by cascading superconducting active devices. The power combiner can include N active elements. The resulting (N.times.M) matrix amplifier can produce signals of high output power, large bandwidth, and low noise.

  16. A single amino acid deletion in the matrix protein of porcine reproductive and respiratory syndrome virus confers resistance to a polyclonal swine antibody with broadly neutralizing activity.

    PubMed

    Trible, Benjamin R; Popescu, Luca N; Monday, Nicholas; Calvert, Jay G; Rowland, Raymond R R

    2015-06-01

    Assessment of virus neutralization (VN) activity in 176 pigs infected with porcine reproductive and respiratory syndrome virus (PRRSV) identified one pig with broadly neutralizing activity. A Tyr-10 deletion in the matrix protein provided escape from broad neutralization without affecting homologous neutralizing activity. The role of the Tyr-10 deletion was confirmed through an infectious clone with a Tyr-10 deletion. The results demonstrate differences in the properties and specificities of VN responses elicited during PRRSV infection.

  17. Causes of difficulty in duration judgments: comment on Francuz and Oleś (2011).

    PubMed

    Okazaki, Yoshihiro S; Matsuda, Fumiko; Fumiko, Matsuda

    2012-12-01

    In 2011, Okazaki and Matsuda showed in studies that college students could not correctly estimate the duration of movement of two objects. Fancuz and Oleś (2011) proposed two explanations of the observed task difficulty. First, they suggested that the cause of the difficulty for the duration judgments involved the experimental procedure, which may have overloaded the cognitive capacities of these students. This study presents results that indicate there was no overload. Second, because the training was intended to improve response accuracy, but it failed to significantly increase accuracy rates, Fancuz and Oleś (2011) suggested there was insufficient time for learning about the task. With respect to these results, Fancuz and Oleś (2011) are correct in pointing out that the training duration could be an issue.

  18. OLED Fundamentals: Materials, Devices, and Processing of Organic Light-Emitting Diodes

    SciTech Connect

    Blochwitz-Nimoth, Jan; Bhandari, Abhinav; Boesch, Damien; Fincher, Curtis R.; Gaspar, Daniel J.; Gotthold, David W.; Greiner, Mark T.; Kido, Junji; Kondakov, Denis; Korotkov, Roman; Krylova, Valentina A.; Loeser, Falk; Lu, Min-Hao; Lu, Zheng-Hong; Lussem, Bjorn; Moro, Lorenza; Padmaperuma, Asanga B.; Polikarpov, Evgueni; Rostovtsev, Vsevolod V.; Sasabe, Hisahiro; Silverman, Gary; Thompson, Mark E.; Tietze, Max; Tyan, Yuan-Sheng; Weaver, Michael; Xin , Xu; Zeng, Xianghui

    2015-05-26

    What is an organic light emitting diode (OLED)? Why should we care? What are they made of? How are they made? What are the challenges in seeing these devices enter the marketplace in various applications? These are the questions we hope to answer in this book, at a level suitable for knowledgeable non-experts, graduate students and scientists and engineers working in the field who want to understand the broader context of their work. At the most basic level, an OLED is a promising new technology composed of some organic material sandwiched between two electrodes. When current is passed through the device, light is emitted. The stack of layers can be very thin and has many variations, including flexible and/or transparent. The organic material can be polymeric or composed small molecules, and may include inorganic components. The electrodes may consist of metals, metal oxides, carbon nanomaterials, or other species, though of course for light to be emitted, one electrode must be transparent. OLEDs may be fabricated on glass, metal foils, or polymer sheets (though polymeric substrates must be modified to protect the organic material from moisture or oxygen). In any event, the organic material must be protected from moisture during storage and operation. A control circuit, the exact nature of which depends on the application, drives the OLED. Nevertheless, the control circuit should have very stable current control to generate uniform light emission. OLEDs can be designed to emit a single color of light, white light, or even tunable colors. The devices can be switched on and off very rapidly, which makes them suitable for displays or for general lighting. Given the amazing complexity of the technical and design challenges for practical OLED applications, it is not surprising that applications are still somewhat limited. Although organic electroluminescence is more than 50 years old, the modern OLED field is really only about half that age – with the first high

  19. Differences between vacuum-deposited and spin-coated amorphous films of OLED materials (presentation video)

    NASA Astrophysics Data System (ADS)

    Yokoyama, Daisuke; Shibata, Maki

    2014-10-01

    To realize low-cost fabrication processes for high-performance OLED displays and lighting panels, the understanding of solution-processed films and devices is becoming more important nowadays. However, differences between vacuum- and solution-processed films have not been sufficiently discussed, and they are sometimes regarded as identical. In this presentation, we show and discuss the important differences between physical properties of vacuum-deposited and spin-coated films of small-molecule OLED materials, especially focusing on the differences in film densities and molecular orientation. Since they are fundamental factors affecting both electrical and optical properties of amorphous films used in OLEDs, we should consider their differences carefully when discussing device performances in detail.

  20. Activated Hepatic Stellate Cells Are Dependent on Self-collagen, Cleaved by Membrane Type 1 Matrix Metalloproteinase for Their Growth

    PubMed Central

    Birukawa, Naoko Kubo; Murase, Kazuyuki; Sato, Yasushi; Kosaka, Akemi; Yoneda, Akihiro; Nishita, Hiroki; Fujita, Ryosuke; Nishimura, Miyuki; Ninomiya, Takafumi; Kajiwara, Keiko; Miyazaki, Miyono; Nakashima, Yusuke; Ota, Sigenori; Murakami, Yuya; Tanaka, Yasunobu; Minomi, Kenjiro; Tamura, Yasuaki; Niitsu, Yoshiro

    2014-01-01

    Stellate cells are distributed throughout organs, where, upon chronic damage, they become activated and proliferate to secrete collagen, which results in organ fibrosis. An intriguing property of hepatic stellate cells (HSCs) is that they undergo apoptosis when collagen is resolved by stopping tissue damage or by treatment, even though the mechanisms are unknown. Here we disclose the fact that HSCs, normal diploid cells, acquired dependence on collagen for their growth during the transition from quiescent to active states. The intramolecular RGD motifs of collagen were exposed by cleavage with their own membrane type 1 matrix metalloproteinase (MT1-MMP). The following evidence supports this conclusion. When rat activated HSCs (aHSCs) were transduced with siRNA against the collagen-specific chaperone gp46 to inhibit collagen secretion, the cells underwent autophagy followed by apoptosis. Concomitantly, the growth of aHSCs was suppressed, whereas that of quiescent HSCs was not. These in vitro results are compatible with the in vivo observation that apoptosis of aHSCs was induced in cirrhotic livers of rats treated with siRNAgp46. siRNA against MT1-MMP and addition of tissue inhibitor of metalloproteinase 2 (TIMP-2), which mainly inhibits MT1-MMP, also significantly suppressed the growth of aHSCs in vitro. The RGD inhibitors echistatin and GRGDS peptide and siRNA against the RGD receptor αVβ1 resulted in the inhibition of aHSCs growth. Transduction of siRNAs against gp46, αVβ1, and MT1-MMP to aHSCs inhibited the survival signal of PI3K/AKT/IκB. These results could provide novel antifibrosis strategies. PMID:24867951

  1. Modulation of F0F1-ATP synthase activity by cyclophilin D regulates matrix adenine nucleotide levels

    PubMed Central

    Chinopoulos, Christos; Konràd, Csaba; Kiss, Gergely; Metelkin, Eugeniy; Töröcsik, Beata; Zhang, Steven F.; Starkov, Anatoly A.

    2011-01-01

    Cyclophilin D was recently shown to bind to and decrease the activity of F0F1-ATP synthase in submitochondrial particles and permeabilized mitochondria (Giorgio et al. 2009, J Biol Chem, 284:33982). Cyclophilin D binding decreased both the ATP synthesis and hydrolysis rates. Here, we reaffirm these findings by demonstrating that in intact mouse liver mitochondria energized by ATP, absence of cyclophilin D or presence of cyclosporin A led to a decrease in the extent of uncoupler-induced depolarization. Accordingly, in substrate-energized mitochondria an increase in F0F1-ATP synthase activity mediated by a relief of inhibition by cyclophilin D was evident as slightly increased respiration rates during arsenolysis. However, the modulation of F0F1-ATP synthase by cyclophilin D did not increase the ANT-mediated ATP efflux rate in energized mitochondria or the ATP influx rate in de-energized mitochondria. The lack of effect of cyclophilin D on the ANT-mediated adenine nucleotide exchange rate was attributed to the ~2.2 times lower flux control coefficient of the F0F1-ATP synthase than that of ANT, deduced from measurements of adenine nucleotide flux rates in intact mitochondria. These findings were further supported by a recent kinetic model of the mitochondrial phosphorylation system, suggesting that a ~30% change in F0F1-ATP synthase activity in fully energized or fully deenergized mitochondria affects ADP-ATP exchange rate mediated by the ANT in the range of 1.38-1.7%. We conclude that in mitochondria exhibiting intact inner membranes, the absence of cyclophilin D or inhibition of its binding to F0F1-ATP synthase by cyclosporin A will affect only matrix adenine nucleotides levels. PMID:21281446

  2. Activated hepatic stellate cells are dependent on self-collagen, cleaved by membrane type 1 matrix metalloproteinase for their growth.

    PubMed

    Birukawa, Naoko Kubo; Murase, Kazuyuki; Sato, Yasushi; Kosaka, Akemi; Yoneda, Akihiro; Nishita, Hiroki; Fujita, Ryosuke; Nishimura, Miyuki; Ninomiya, Takafumi; Kajiwara, Keiko; Miyazaki, Miyono; Nakashima, Yusuke; Ota, Sigenori; Murakami, Yuya; Tanaka, Yasunobu; Minomi, Kenjiro; Tamura, Yasuaki; Niitsu, Yoshiro

    2014-07-18

    Stellate cells are distributed throughout organs, where, upon chronic damage, they become activated and proliferate to secrete collagen, which results in organ fibrosis. An intriguing property of hepatic stellate cells (HSCs) is that they undergo apoptosis when collagen is resolved by stopping tissue damage or by treatment, even though the mechanisms are unknown. Here we disclose the fact that HSCs, normal diploid cells, acquired dependence on collagen for their growth during the transition from quiescent to active states. The intramolecular RGD motifs of collagen were exposed by cleavage with their own membrane type 1 matrix metalloproteinase (MT1-MMP). The following evidence supports this conclusion. When rat activated HSCs (aHSCs) were transduced with siRNA against the collagen-specific chaperone gp46 to inhibit collagen secretion, the cells underwent autophagy followed by apoptosis. Concomitantly, the growth of aHSCs was suppressed, whereas that of quiescent HSCs was not. These in vitro results are compatible with the in vivo observation that apoptosis of aHSCs was induced in cirrhotic livers of rats treated with siRNAgp46. siRNA against MT1-MMP and addition of tissue inhibitor of metalloproteinase 2 (TIMP-2), which mainly inhibits MT1-MMP, also significantly suppressed the growth of aHSCs in vitro. The RGD inhibitors echistatin and GRGDS peptide and siRNA against the RGD receptor αVβ1 resulted in the inhibition of aHSCs growth. Transduction of siRNAs against gp46, αVβ1, and MT1-MMP to aHSCs inhibited the survival signal of PI3K/AKT/IκB. These results could provide novel antifibrosis strategies.

  3. Interleukin-1{beta} regulates cell proliferation and activity of extracellular matrix remodelling enzymes in cultured primary pig heart cells

    SciTech Connect

    Zitta, Karina; Brandt, Berenice; Wuensch, Annegret; Meybohm, Patrick; Bein, Berthold; Steinfath, Markus; Scholz, Jens; Albrecht, Martin

    2010-09-03

    Research highlights: {yields} Levels of IL-1{beta} are increased in the pig myocardium after infarction. {yields} Cultured pig heart cells possess IL-1 receptors. {yields} IL-1{beta} increases cell proliferation of pig heart cells in-vitro. {yields} IL-1{beta} increases MMP-2 and MMP-9 activity in pig heart cells in-vitro. {yields} IL-1{beta} may be important for tissue remodelling events after myocardial infarction. -- Abstract: After myocardial infarction, elevated levels of interleukins (ILs) are found within the myocardial tissue and IL-1{beta} is considered to play a major role in tissue remodelling events throughout the body. In the study presented, we have established a cell culture model of primary pig heart cells to evaluate the effects of different concentrations of IL-1{beta} on cell proliferation as well as expression and activity of enzymes typically involved in tissue remodelling. Primary pig heart cell cultures were derived from three different animals and stimulated with recombinant pig IL-1{beta}. RNA expression was detected by RT-PCR, protein levels were evaluated by Western blotting, activity of matrix metalloproteinases (MMPs) was quantified by gelatine zymography and cell proliferation was measured using colorimetric MTS assays. Pig heart cells express receptors for IL-1 and application of IL-1{beta} resulted in a dose-dependent increase of cell proliferation (P < 0.05 vs. control; 100 ng/ml; 24 h). Gene expression of caspase-3 was increased by IL-1{beta} (P < 0.05 vs. control; 100 ng/ml; 3 h), and pro-caspase-3 but not active caspase was detected in lysates of pig heart cells by Western blotting. MMP-2 gene expression as well as enzymatic activities of MMP-2 and MMP-9 were increased by IL-1{beta} (P < 0.05 vs. control; 100 ng/ml; 3 h for gene expression, 48 and 72 h for enzymatic activities of MMP-2 and MMP-9, respectively). Our in vitro data suggest that IL-1{beta} plays a major role in the events of tissue remodelling in the heart. Combined

  4. Advances in OLED/OPD-based spectrometer on-a-chip

    NASA Astrophysics Data System (ADS)

    Manna, Eeshita; Fungura, Fadzai; Shinar, Joseph; Shinar, Ruth

    2015-08-01

    We describe ongoing advances toward achieving an integrated all-organic spectrometer on a chip. To this end, 2-dimensional combinatorial arrays of microcavity (μc) organic light emitting diodes (OLEDs) with systematically varying optical cavity lengths were fabricated on a single chip by changing the thickness of different organic and/or spacer layers sandwiched between the two metal electrodes. The latter, one of which is semitransparent, form the cavity. The tunable and narrower emissions from the μcOLEDs serve as excitation sources of varying wavelength for monitoring light absorption or emission. For each wavelength, the light from the μcOLED is partially absorbed by the sample under study and the transmitted light (or the light emitted by an electronically excited sample) is detected by a photodetector (PD). To obtain a compact monitor, an organic PD (OPD) is fabricated and integrated with the μcOLED array. We show the potential of encompassing a broader wavelength range by using μcOLEDs based on different emitting layers. The OPD used to realize the first all-organic integrated spectrometer described here is based on P3HT:PCBM, though more sensitive OPDs we utilized in sensing applications are expected to improve the spectrometers' performance. The utility of this all-organic μcOLED/OPD spectrometer is shown for monitoring the absorption spectra of P3HT and Alexa Fluor 405 films. The results show excellent agreement with the absorption spectra obtained with a commercial Ocean Optics spectrometer.

  5. Color tunability in multilayer OLEDs based on DCM and DPVBi as emitting materials

    NASA Astrophysics Data System (ADS)

    Petrova, P. K.; Ivanov, P. I.; Tomova, R. L.

    2014-05-01

    We report studies on the color tunability of a novel type of multilayer organic light-emitting diodes (OLEDs) based on three emitting materials: DCM (4-(Dicyanomethylene)-2-methyl-6-[p-(dimethylamino)styryl]-4H-pyran) as a red emitter, DPVBi [4,4'-Bis(2,2-diphenylvinyl)-1,1'-biphenyl] as a blue emitter and zinc bis(2-(2-hydroxyphenyl) benzothiazole) (Zn(BTz)2) as a yellow emitter, and an electron transporting layer. We established that the positions and thicknesses of the different emitting layers determine the efficiencies, luminance and color of the light emitted by the OLEDs.

  6. Enhanced color purity of blue OLEDs based on well-design structure

    NASA Astrophysics Data System (ADS)

    Du, Qianqian; Wang, Wenjun; Li, Shuhong; Wang, Qingru; Xia, Shuzhen; Zhang, Bingyuan; Wang, Minghong; Fan, Quli

    2016-09-01

    We have fabricated blue organic light-emitting devices (OLEDs) with higher color purity and stability by optimizing the structure of the Glass/ITO/NPB(50 nm)/ BCzVBi (30 nm)/ TPBi (x nm)/Alq3(20 nm)/LiF/Al. The results show that the introducing of hole blocking layer(HBL) TPBi greatly can improve not only the color purity but the color stability, which owe to its higher the Highest Occupied Molecular Orbital (HOMO) energy levels of 6.2 eV. We expect our work will be useful to optimizing the blue OLEDs structure to enhancing the color property.

  7. Organic Light-Emitting Diodes (OLEDs) and Optically-Detected Magnetic Resonance (ODMR) studies on organic materials

    SciTech Connect

    Cai, Min

    2011-01-01

    Organic semiconductors have evolved rapidly over the last decades and currently are considered as the next-generation technology for many applications, such as organic light-emitting diodes (OLEDs) in flat-panel displays (FPDs) and solid state lighting (SSL), and organic solar cells (OSCs) in clean renewable energy. This dissertation focuses mainly on OLEDs. Although the commercialization of the OLED technology in FPDs is growing and appears to be just around the corner for SSL, there are still several key issues that need to be addressed: (1) the cost of OLEDs is very high, largely due to the costly current manufacturing process; (2) the efficiency of OLEDs needs to be improved. This is vital to the success of OLEDs in the FPD and SSL industries; (3) the lifetime of OLEDs, especially blue OLEDs, is the biggest technical challenge. All these issues raise the demand for new organic materials, new device structures, and continued lower-cost fabrication methods. In an attempt to address these issues, we used solution-processing methods to fabricate highly efficient small molecule OLEDs (SMOLEDs); this approach is costeffective in comparison to the more common thermal vacuum evaporation. We also successfully made efficient indium tin oxide (ITO)-free SMOLEDs to further improve the efficiency of the OLEDs. We employed the spin-dependent optically-detected magnetic resonance (ODMR) technique to study the luminescence quenching processes in OLEDs and organic materials in order to understand the intrinsic degradation mechanisms. We also fabricated polymer LEDs (PLEDs) based on a new electron-accepting blue-emitting polymer and studied the effect of molecular weight on the efficiency of PLEDs. All these studies helped us to better understand the underlying relationship between the organic semiconductor materials and the OLEDs’ performance, and will subsequently assist in further enhancing the efficiency of OLEDs. With strongly improved device performance (in addition to

  8. Active site specificity profiling datasets of matrix metalloproteinases (MMPs) 1, 2, 3, 7, 8, 9, 12, 13 and 14

    PubMed Central

    Eckhard, Ulrich; Huesgen, Pitter F.; Schilling, Oliver; Bellac, Caroline L.; Butler, Georgina S.; Cox, Jennifer H.; Dufour, Antoine; Goebeler, Verena; Kappelhoff, Reinhild; auf dem Keller, Ulrich; Klein, Theo; Lange, Philipp F.; Marino, Giada; Morrison, Charlotte J.; Prudova, Anna; Rodriguez, David; Starr, Amanda E.; Wang, Yili; Overall, Christopher M.

    2016-01-01

    The data described provide a comprehensive resource for the family-wide active site specificity portrayal of the human matrix metalloproteinase family. We used the high-throughput proteomic technique PICS (Proteomic Identification of protease Cleavage Sites) to comprehensively assay 9 different MMPs. We identified more than 4300 peptide cleavage sites, spanning both the prime and non-prime sides of the scissile peptide bond allowing detailed subsite cooperativity analysis. The proteomic cleavage data were expanded by kinetic analysis using a set of 6 quenched-fluorescent peptide substrates designed using these results. These datasets represent one of the largest specificity profiling efforts with subsequent structural follow up for any protease family and put the spotlight on the specificity similarities and differences of the MMP family. A detailed analysis of this data may be found in Eckhard et al. (2015) [1]. The raw mass spectrometry data and the corresponding metadata have been deposited in PRIDE/ProteomeXchange with the accession number PXD002265. PMID:26981551

  9. Image quality affected by diffraction of aperture structure arrangement in transparent active-matrix organic light-emitting diode displays.

    PubMed

    Tsai, Yu-Hsiang; Huang, Mao-Hsiu; Jeng, Wei-de; Huang, Ting-Wei; Lo, Kuo-Lung; Ou-Yang, Mang

    2015-10-01

    Transparent display is one of the main technologies in next-generation displays, especially for augmented reality applications. An aperture structure is attached on each display pixel to partition them into transparent and black regions. However, diffraction blurs caused by the aperture structure typically degrade the transparent image when the light from a background object passes through finite aperture window. In this paper, the diffraction effect of an active-matrix organic light-emitting diode display (AMOLED) is studied. Several aperture structures have been proposed and implemented. Based on theoretical analysis and simulation, the appropriate aperture structure will effectively reduce the blur. The analysis data are also consistent with the experimental results. Compared with the various transparent aperture structure on AMOLED, diffraction width (zero energy position of diffraction pattern) of the optimize aperture structure can be reduced 63% and 31% in the x and y directions in CASE 3. Associated with a lenticular lens on the aperture structure, the improvement could reach to 77% and 54% of diffraction width in the x and y directions. Modulation transfer function and practical images are provided to evaluate the improvement of image blurs.

  10. Effect of transparent film desiccant on the lifetime of top-emitting active matrix organic light emitting diodes

    NASA Astrophysics Data System (ADS)

    Lee, Byoung Duk; Cho, Yoon-Hyung; Kim, Won-Jong; Oh, Min Ho; Lee, Jong Hyuk; Zang, Dong Sik

    2007-03-01

    The effects of a transparent film desiccant on the lifetime of top-emitting active matrix organic light emitting diodes (AMOLEDs) were investigated. The transparent film desiccants were prepared by mixing solutions dispersed with calcium oxide powders and ultraviolet-curable resins. As the solid content in the solutions increased from 15to30wt%, the average particle size increased from 107to240nm, whereas the transmittance of the films decreased from 98% to 80% in the visible range. The devices encapsulated with the transparent film desiccants which contained 20wt% CaO exhibited no dark spots and 97% of the initial luminance, even after being stored for over 500h at 70°C and 90% relative humidity. Also, the operational lifetime of these devices was 1850h, ten times longer than that of a device without desiccant. These results confirmed that the transparent film desiccants, which absorbed the moisture that penetrated into the devices, could be applied to the encapsulation of top-emitting AMOLEDs.

  11. Optimal Topology and Experimental Evaluation of Piezoelectric Materials for Actively Shunted General Electric Polymer Matrix Fiber Composite Blades

    NASA Technical Reports Server (NTRS)

    Choi, Benjamin B.; Duffy, Kirsten; Kauffman, Jeffrey L.; Kray, Nicholas

    2012-01-01

    NASA Glenn Research Center, in collaboration with GE Aviation, has begun the development of a smart adaptive structure system with piezoelectric (PE) transducers to improve composite fan blade damping at resonances. Traditional resonant damping approaches may not be realistic for rotating frame applications such as engine blades. The limited space in which the blades reside in the engine makes it impossible to accommodate the circuit size required to implement passive resonant damping. Thus, a novel digital shunt scheme has been developed to replace the conventional electric passive shunt circuits. The digital shunt dissipates strain energy through the load resistor on a power amplifier. General Electric (GE) designed and fabricated a variety of polymer matrix fiber composite (PMFC) test specimens. Investigating the optimal topology of PE sensors and actuators for each test specimen has revealed the best PE transducer location for each target mode. Also a variety of flexible patches, which can conform to the blade surface, have been tested to identify the best performing PE patch. The active damping control achieved significant performance at target modes. This work has been highlighted by successful spin testing up to 5000 rpm of subscale GEnx composite blades in Glenn s Dynamic Spin Rig.

  12. Activated matrix metalloproteinase-8 in saliva as diagnostic test for periodontal disease? A case-control study.

    PubMed

    Izadi Borujeni, Susan; Mayer, Matthias; Eickholz, Peter

    2015-12-01

    Untreated periodontal disease may influence general health. However, how may a physician, who is not trained in periodontal probing, detect untreated periodontitis? Activated matrix metalloproteinase-8 (aMMP-8) in saliva correlates with periodontal probing parameters. Thus, sensitivity and specificity of a chair-side test for aMMP-8 to detect periodontitis were evaluated. Thirty cases [untreated chronic periodontitis (ChP); 15 generalized moderate and 15 generalized severe] and 30 controls [probing depths (PD) ≤3 mm, vertical probing attachment level (PAL-V) ≤2 mm at <30 % of sites) were examined periodontally (PD, PAL-V, bleeding on probing). Subsequently, the aMMP-8 test was performed. The test kit becomes positive with ≥25 ng/ml aMMP-8 in the sample. The aMMP-8 test was positive in 87 % of ChP and in 40 % of controls. That corresponds to a sensitivity of 87 % and a specificity of 60 %. The sensitivity to detect generalized severe ChP was 93 % (60 % specificity). Backward stepwise logistic regression analysis to explain positive aMMP-8 tests identified exclusively ChP with an odds ratio of 9.8 (p < 0.001). Positive results of the aMMP-8 test significantly correlate with generalized ChP. The aMMP-8 test may be used by physicians to detect periodontitis in their patients.

  13. Optimal topology and experimental evaluation of PE materials for actively shunted GE polymer matrix fiber composite blades

    NASA Astrophysics Data System (ADS)

    Choi, Benjamin B.; Duffy, Kirsten; Kauffman, Jeffrey L.; Kray, Nicholas

    2012-04-01

    NASA Glenn Research Center (GRC), in collaboration with GE Aviation, has begun the development of a smart adaptive structure system with piezoelectric transducers to improve composite fan blade damping at resonances. Traditional resonant damping approaches may not be realistic for rotating frame applications such as engine blades. The limited space in which the blades reside in the engine makes it impossible to accommodate the circuit size required to implement passive resonant damping. Thus, we have developed a novel digital shunt scheme to replace the conventional electric passive shunt circuits. The digital shunt dissipates strain energy through the load capacitor on a power amplifier. GE designed and fabricated a variety of polymer matrix fiber composite (PMFC) test specimens. We investigated the optimal topology of PE sensors and actuators for each test specimen to discover the best PE transducer location for each target mode. Also a variety of flexible patches, which can conform to the blade surface, have been tested to identify the best performing piezoelectric patch. The active damping control achieved significant performance at target modes. This work has been highlighted by successful spin testing up to 5,000 rpm of subscale GEnx composite blades in GRC's Dynamic Spin Rig.

  14. Orally administered betaine reduces photodamage caused by UVB irradiation through the regulation of matrix metalloproteinase-9 activity in hairless mice.

    PubMed

    Im, A-Rang; Lee, Hee Jeong; Youn, Ui Joung; Hyun, Jin Won; Chae, Sungwook

    2016-01-01

    Betaine is widely distributed in plants, microorganisms, in several types of food and in medical herbs, including Lycium chinense. The administration of 100 mg betaine/kg body weight/day is an effective strategy for preventing ultraviolet irradiation‑induced skin damage. The present study aimed to determine the preventive effects of betaine on ultraviolet B (UVB) irradiation‑induced skin damage in hairless mice. The mice were divided into three groups: Control (n=5), UVB‑treated vehicle (n=5) and UVB‑treated betaine (n=5) groups. The level of irradiation was progressively increased between 60 mJ/cm2 per exposure at week 1 (one minimal erythematous dose = 60 mJ/cm2) and 90 mJ/cm2 per exposure at week 7. The formation of wrinkles significantly increased following UVB exposure in the UVB‑treated vehicle group. However, treatment with betaine suppressed UVB‑induced wrinkle formation, as determined by the mean length, mean depth, number, epidermal thickness and collagen damage. Furthermore, oral administration of betaine also inhibited the UVB‑induced expression of mitogen‑activated protein kinase kinase (MEK), extracellular signal‑regulated kinase (ERK), and matrix metalloproteinase‑9 (MMP‑9). These findings suggested that betaine inhibits UVB‑induced skin damage by suppressing increased expression of MMP‑9 through the inhibition of MEK and ERK.

  15. Pesticide-Exposure Matrix

    Cancer.gov

    The "Pesticide-exposure Matrix" was developed to help epidemiologists and other researchers identify the active ingredients to which people were likely exposed when their homes and gardens were treated for pests in past years.

  16. Anti-invasive activity of diallyl disulfide through tightening of tight junctions and inhibition of matrix metalloproteinase activities in LNCaP prostate cancer cells.

    PubMed

    Shin, Dong Yeok; Kim, Gi-Young; Kim, Jung-In; Yoon, Moo Kyoung; Kwon, Taeg Kyu; Lee, Su Jae; Choi, Young-Whan; Kang, Ho Sung; Yoo, Young Hyun; Choi, Yung Hyun

    2010-09-01

    Diallyl disulfide (DADS) is a major component of an oil-soluble allyl sulfide garlic (Allium sativum) derivative, which has been shown to exert a potential for anti-cancer activity. However, the biochemical mechanisms underlying DADS-induced anti-invasiveness and anti-metastasis have not been thoroughly studied. In this study, we investigated the effect of DADS on the correlation between tightening of tight junctions (TJs) and anti-invasive activity in human prostate carcinoma LNCaP cells. Inhibitory effects of DADS on cell motility and invasiveness were found to be associated with increased tightness of the TJ, which was demonstrated by an increase in transepithelial electrical resistance (TER). Additionally, immunoblotting results indicated that DADS repressed the levels of the claudin proteins, which are major components of TJs that play a key role in control and selectivity of paracellular transport. Furthermore, the activities of matrix metalloproteinase (MMP)-2 and -9 in LNCaP cells were dose-dependently inhibited by treatment with DADS, and this was also correlated with a decrease in expression of their mRNA and proteins. Although further studies are needed, the present study indicates that TJs and MMPs are critical targets of DADS-induced anti-invasiveness in human prostate cancer LNCaP cells.

  17. Transdermal delivery of Diltiazem HCl from matrix film: Effect of penetration enhancers and study of antihypertensive activity in rabbit model

    PubMed Central

    Parhi, Rabinarayan; Suresh, Padilam

    2015-01-01

    The present investigation focused on the development of Diltiazem HCl (DTH) matrix film and its characterization by in-vitro, ex-vivo and in-vivo methods. Films were prepared by solvent casting method by taking different ratios of hydroxypropyl methylcellulose K4M (HPMC K4M) and Eudragit RS100. Various parameters of the films were analyzed such as mechanical property using tensile tester, interaction study by Fourier transform infrared spectroscopy (FTIR) and Thermogravimetric analysis (TGA), in-vitro drug release through cellulose acetate membrane, ex-vivo permeation study using abdominal skin of rat employing Franz diffusion cell, and in-vivo antihypertensive activity using rabbit model. The FTIR studies confirmed the absence of interaction between DTH and selected polymers. Thermal analysis showed the shifting of endothermic peak of DTH in film, indicating the dispersion of DTH in molecular form throughout the film. Incorporation of 1,8-cineole showed highest flux (89.7 μg/cm2/h) of DTH compared to other penetration enhancers such as capsaicin, dimethyl sulfoxide (DMSO), and N-methyl pyrrolidone (NMP). Photomicrographs of histology study on optimized formulation (DF9) illustrated disruption of stratum corneum (SC) supporting the ex-vivo results. The in-vivo antihypertensive activity results demonstrated that formulation DF9 was effective in reducing arterial blood pressure in normotensive rabbits. SEM analysis of films kept for stability study (40 ± 2 °C/75% ± 5%RH for 3 months) revealed the formation of drug crystals which may be due to higher temperature. The findings of the study provide a better alternative dosage form of DTH for the effective treatment of hypertension with enhanced patient compliance. PMID:27222758

  18. Determination of the detective quantum efficiency of a prototype, megavoltage indirect detection, active matrix flat-panel imager.

    PubMed

    El-Mohri, Y; Jee, K W; Antonuk, L E; Maolinbay, M; Zhao, Q

    2001-12-01

    After years of aggressive development, active matrix flat-panel imagers (AMFPIs) have recently become commercially available for radiotherapy imaging. In this paper we report on a comprehensive evaluation of the signal and noise performance of a large-area prototype AMFPI specifically developed for this application. The imager is based on an array of 512 x 512 pixels incorporating amorphous silicon photodiodes and thin-film transistors offering a 26 x 26 cm2 active area at a pixel pitch of 508 microm. This indirect detection array was coupled to various x-ray converters consisting of a commercial phosphor screen (Lanex Fast B, Lanex Regular, or Lanex Fine) and a 1 mm thick copper plate. Performance of the imager in terms of measured sensitivity, modulation transfer function (MTF), noise power spectra (NPS), and detective quantum efficiency (DQE) is reported at beam energies of 6 and 15 MV and at doses of 1 and 2 monitor units (MU). In addition, calculations of system performance (NPS, DQE) based on cascaded-system formalism were reported and compared to empirical results. In these calculations, the Swank factor and spatial energy distributions of secondary electrons within the converter were modeled by means of EGS4 Monte Carlo simulations. Measured MTFs of the system show a weak dependence on screen type (i.e., thickness), which is partially due to the spreading of secondary radiation. Measured DQE was found to be independent of dose for the Fast B screen, implying that the imager is input-quantum-limited at 1 MU, even at an extended source-to-detector distance of 200 cm. The maximum DQE obtained is around 1%--a limit imposed by the low detection efficiency of the converter. For thinner phosphor screens, the DQE is lower due to their lower detection efficiencies. Finally, for the Fast B screen, good agreement between calculated and measured DQE was observed.

  19. Robust-adaptive active vibration control of alloy and flexible matrix composite rotorcraft drivelines via magnetic bearings: Theory and experiment

    NASA Astrophysics Data System (ADS)

    Desmidt, Hans A.

    This thesis explores the use of Active Magnetic Bearing (AMB) technology and newly emerging Flexible Matrix Composite (FMC) materials to advance the state-of-the-art of rotorcraft and other high performance driveline systems. Specifically, two actively controlled tailrotor driveline configurations are explored. The first driveline configuration (Configuration I) consists of a multi-segment alloy driveline connected by Non-Constant-Velocity (NCV) flexible couplings and mounted on non-contact AMB devices. The second configuration (Configuration II) consists of a single piece, rigidly coupled, FMC shaft supported by AMBs. For each driveline configuration, a novel hybrid robust-adaptive vibration control strategy is theoretically developed and experimentally validated based on the specific driveline characteristics and uncertainties. In the case of Configuration I, the control strategy is based on a hybrid design consisting of a PID feedback controller augmented with a slowly adapting, Multi-Harmonic Adaptive Vibration Control (MHAVC) input. Here, the control is developed to ensure robustness with respect to the driveline operating conditions e.g. driveline misalignment, load-torque, shaft speed and shaft imbalance. The analysis shows that the hybrid PID/MHAVC control strategy achieves multi-harmonic suppression of the imbalance, misalignment and load-torque induced driveline vibration over a range of operating conditions. Furthermore, the control law developed for Configuration II is based on a hybrid robust Hinfinity feedback/Synchronous Adaptive Vibration Control (SAVC) strategy. Here, the effects of temperature dependent FMC material properties, rotating-frame damping and shaft imbalance are considered in the control design. The analysis shows that the hybrid Hinfinity/SAVC control strategy guarantees stability, convergence and imbalance vibration suppression under the conditions of bounded temperature deviations and unknown imbalance. Finally, the robustness and

  20. Investigation of cross-linking characteristics of novel hole-transporting materials for solution-processed phosphorescent OLEDs

    NASA Astrophysics Data System (ADS)

    Lee, Jaemin; Ameen, Shahid; Lee, Changjin

    2016-04-01

    After the success of commercialization of the vacuum-evaporated organic light-emitting diodes (OLEDs), solutionprocessing or printing of OLEDs are currently attracting much research interests. However, contrary to various kinds of readily available vacuum-evaporable OLED materials, the solution-processable OLED materials are still relatively rare. Hole-transporting layer (HTL) materials for solution-processed OLEDs are especially limited, because they need additional characteristics such as cross-linking to realize multilayer structures in solution-processed OLEDs, as well as their own electrically hole-transporting characteristics. The presence of such cross-linking characteristics of solutionprocessable HTL materials therefore makes them more challenging in the development stage, and also makes them essence of solution-processable OLED materials. In this work, the structure-property relationships of thermally crosslinkable HTL materials were systematically investigated by changing styrene-based cross-linking functionalities and modifying the carbazole-based hole-transporting core structures. The temperature dependency of the cross-linking characteristics of the HTL materials was systematically investigated by the UV-vis. absorption spectroscopy. The new HTL materials were also applied to green phosphorescent OLEDs, and their device characteristics were also investigated based on the chemical structures of the HTL materials. The device configuration was [ITO / PEDOT:PSS / HTL / EML / ETL / CsF / Al]. We found out that the chemical structures of the cross-linking functionalities greatly affect not only the cross-linking characteristics of the resultant HTL materials, but also the resultant OLED device characteristics. The increase of the maximum luminance and efficiency of OLEDs was evident as the cross-linking temperature decreases from higher than 200°C to at around 150°C.

  1. Permanent polarization and charge distribution in organic light-emitting diodes (OLEDs): Insights from near-infrared charge-modulation spectroscopy of an operating OLED

    SciTech Connect

    Marchetti, Alfred P.; Haskins, Terri L.; Young, Ralph H.; Rothberg, Lewis J.

    2014-03-21

    Vapor-deposited Alq{sub 3} layers typically possess a strong permanent electrical polarization, whereas NPB layers do not. (Alq{sub 3} is tris(8-quinolinolato)aluminum(III); NPB is 4,4′-bis[N-(1-naphthyl)-N-phenylamino]biphenyl.) The cause is a net orientation of the Alq{sub 3} molecules with their large dipole moments. Here we report on consequences for an organic light-emitting diode (OLED) with an NPB hole-transport layer and Alq{sub 3} electron-transport layer. The discontinuous polarization at the NPB|Alq{sub 3} interface has the same effect as a sheet of immobile negative charge there. It is more than compensated by a large concentration of injected holes (NPB{sup +}) when the OLED is running. We discuss the implications and consequences for the quantum efficiency and the drive voltage of this OLED and others. We also speculate on possible consequences of permanent polarization in organic photovoltaic devices. The concentration of NPB{sup +} was measured by charge-modulation spectroscopy (CMS) in the near infrared, where the NPB{sup +} has a strong absorption band, supplemented by differential-capacitance and current-voltage measurements. Unlike CMS in the visible, this method avoids complications from modulation of the electroluminescence and electroabsorption.

  2. Efficient solution-processed double-layer red OLEDs based on a new europium complex with a carbazole group.

    PubMed

    Liu, Jian; Miao, Jing-Sheng; Wu, Hong-Bin

    2015-06-01

    A new europium complex EuL3 (Phen) was used as guest dopant, and a blend of Polyvinylcarbazole and 2-(biphenyl-4-yl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (PVK and PBD) as host matrix. Efficient red organic light-emitting devices (OLEDs) with double-layer structures were manufactured via a solution-processed technique. The guest-doped levels were 1, 3 and 5 wt% relative to the blend mass, respectively. For the 1 wt% doping-level device, the luminous efficiency and luminance were up to 2.96 cd/A and 635.78 cd/m(2) with emissions from both EuL3 (Phen) and from the host; for the 3 wt% doping-level device, the maximum luminous efficiency and luminance were 1.01 cd/A and 370.91 cd/m(2) for the single emission from EuL3 (Phen) only.

  3. Immunoproteomic tools are used to identify masked allergens: Ole e 12, an allergenic isoflavone reductase from olive (Olea europaea) pollen.

    PubMed

    Castro, Lourdes; Crespo, Jesús F; Rodríguez, Julia; Rodríguez, Rosalía; Villalba, Mayte

    2015-12-01

    Proteins performing important biochemical activities in the olive tree (Olea europaea) pollen have been identified as allergens. One novel 37-kDa protein seems to be associated to the IgE-binding profile of a group of patients suffering allergy to peach and olive pollen. Three previously described olive pollen allergens exhibit very similar molecular mass. Our objective was to identify this allergen by using immunoproteomic approaches. After 2D-electrophoresis and mass spectrometry, peptide sequences from several IgE-binding spots, allowed identifying this new allergen, as well as cloning and DNA sequencing of the corresponding gene. The allergen, named Ole e 12, is a polymorphic isoflavone reductase-like protein of 308 amino acids showing 80% and 74% identity with birch and pear allergens, Bet v 6 and Pyr c 5, respectively. A prevalence of 33% in the selected population is in contrast to 4%-10% in groups of subjects suffering from pollinosis. Recombinant allergen was produced in Escherichia coli, and deeply characterised. Immunoblotting and ELISA detection as well as inhibition experiments were performed with polyclonal antisera and allergic patients' sera. The recombinant allergen retains the IgE reactivity of its natural counterpart. Close structural and immunological relationships between members of this protein family were supported by their IgG recognition in vegetable species. In summary, Ole e 12 is a minor olive pollen allergen, which gains relevance in patients allergic to peach with olive pollinosis. Proteomic approaches used to analyse this allergen provide useful tools to identify hidden allergens, relevant for several allergic populations and thus complete allergenic panels.

  4. Inverse SORS for detecting a low Raman-active turbid sample placed inside a highly Raman-active diffusely scattering matrix - A feasibility study.

    PubMed

    Khan, Khan Mohd; Dutta, Surjendu B; Krishna, Hemant; Majumder, Shovan K

    2016-09-01

    The broad range of applications of spatially-offset Raman spectroscopy (SORS) were found to involve samples having only marginal differences in Raman cross-sections between the surface and subsurface targets. We report the results of a feasibility study to evaluate the potential of the approach to identify the presence of a very low Raman-active turbid sample placed inside a highly Raman-active diffusely scattering matrix. Paraffin sandwiched tissue blocks prepared by embedding slices of chicken muscle tissue into solid paraffin blocks were employed as representative samples for the study. It was found that in contrast to the several millimetres of probing depth reported in the earlier applications, the Raman signatures of tissue were best recovered when it was located beneath the surface of the paraffin block at a depth of around a millimetre, beyond which the quality of recovery was increasingly poorer. However, the probing depth could be further increased by increasing the thickness of the embedded tissue sections. The results clearly suggest that though the probing depth achievable under the current condition is less than that found in previous applications, nevertheless it is sufficient for various other applications that would not require probing as deep as was required earlier.

  5. Parathyroid hormone activation of matrix metalloproteinase-13 transcription requires the histone acetyltransferase activity of p300 and PCAF and p300-dependent acetylation of PCAF.

    PubMed

    Lee, Minnkyong; Partridge, Nicola C

    2010-12-03

    Parathyroid hormone (PTH) regulates the transcription of many genes involved in bone remodeling in osteoblasts. One of these genes is matrix metalloproteinase-13 (MMP-13), which is involved in bone remodeling and early stages of endochondral bone formation. We have previously shown that Mmp-13 gene expression is highly induced by PTH treatment in osteoblastic UMR 106-01 cells, as well as primary osteoblasts. Here, we show that p300/CBP-associated factor (PCAF), in addition to p300 and Runx2, is required for PTH activation of Mmp-13 transcription. PCAF was increasingly recruited to the MMP-13 proximal promoter region after PTH treatment, and this was associated with an increase in RNA polymerase II recruitment and histone acetylation. In addition, PTH treatment increased the acetylation of PCAF, a process that required p300. Knockdown of PCAF, p300, or Runx2 by siRNA decreased Mmp-13 mRNA expression after PTH treatment in both UMR 106-01 cells and primary osteoblasts. We found that there is a mutual dependence between p300 and PCAF to be recruited to the Mmp-13 promoter after PTH treatment. In promoter-reporter assays, p300 and PCAF had an additive effect on PTH stimulation of MMP-13 promoter activity, and this required their histone acetyltransferase activity. Our findings demonstrate that PCAF acts downstream of PTH signaling as a transcriptional coactivator that is required for PTH stimulation of MMP-13 transcription. PCAF cooperates with p300 and Runx2 to mediate PTH activation of MMP-13 transcription.

  6. Catalytic strategy for carbon−carbon bond scission by the cytochrome P450 OleT

    PubMed Central

    Grant, Job L.; Mitchell, Megan E.; Makris, Thomas Michael

    2016-01-01

    OleT is a cytochrome P450 that catalyzes the hydrogen peroxide-dependent metabolism of Cn chain-length fatty acids to synthesize Cn-1 1-alkenes. The decarboxylation reaction provides a route for the production of drop-in hydrocarbon fuels from a renewable and abundant natural resource. This transformation is highly unusual for a P450, which typically uses an Fe4+−oxo intermediate known as compound I for the insertion of oxygen into organic substrates. OleT, previously shown to form compound I, catalyzes a different reaction. A large substrate kinetic isotope effect (≥8) for OleT compound I decay confirms that, like monooxygenation, alkene formation is initiated by substrate C−H bond abstraction. Rather than finalizing the reaction through rapid oxygen rebound, alkene synthesis proceeds through the formation of a reaction cycle intermediate with kinetics, optical properties, and reactivity indicative of an Fe4+−OH species, compound II. The direct observation of this intermediate, normally fleeting in hydroxylases, provides a rationale for the carbon−carbon scission reaction catalyzed by OleT. PMID:27555591

  7. Improving the viewing angle properties of microcavity OLEDs by using dispersive gratings.

    PubMed

    Choy, Wallace C H; Ho, C Y

    2007-10-01

    The changes of emission peak wavelength and angular intensity with viewing angles have been issues for the use of microcavity OLEDs. We will investigate Distributed Bragg Gratings (DBRs) constructed from largely dispersive index materials for reducing the viewing angle dependence. A DBR stack mirror, aiming at a symmetric structure and less number of grating period for a practical fabrication, is studied to achieve a chirp-featured grating for OLEDs with blue emission peak of 450nm. For maximizing the compensation of the viewing angle dependence, the effects of dispersive index, grating structure, thickness of each layer of the grating, grating period and chirp will be comprehensively investigated. The contributions of TE and TM modes to the angular emission power will be analyzed for the grating optimization, which have not been expressed in detail. In studying the light emission of OLEDs, we will investigate the Purcell effect which is important but has not been properly considered. Our results show that with a proper design of the DBR, not only a wider viewing angle can be achieved but also the color purity of OLEDs can be improved.

  8. Luminescent properties of a di-hydrazone derived from the antituberculosis agent isoniazid: Potentiality as an emitting layer constituent for OLED fabrication

    NASA Astrophysics Data System (ADS)

    Moraes, Rafaela S.; Aderne, Rian E.; Cremona, Marco; Rey, Nicolás A.

    2016-02-01

    Hydrazones constitute a class of compounds presenting azomethine R‧R″Nsbnd Ndbnd CHsbnd R hydrogens, which show diverse properties and a wide range of applications. A hydrazone derived from the antituberculosis drug isoniazid, namely, N,N‧-diisonicotinoyl-2-hydroxy-5-methylisophthalaldehyde hydrazone (DMD) was synthesized and chemically characterized. Its luminescent properties were also investigated, as well as the possibility of using this compound as a constituent of the emitting layer for the fabrication of OLEDs. Co-deposited devices were fabricated using the organic molecule BSBF as matrix and DMD as dopant. All the devices presented a broad electroluminescence band, in which it was possible to recognize the DMD emission along with emissions of some of the other organic layers. The best results were obtained with 35% DMD doping, achieving a luminance of about 35 cd/m2.

  9. Piwil2 modulates the proliferation and metastasis of colon cancer via regulation of matrix metallopeptidase 9 transcriptional activity.

    PubMed

    Li, Dawei; Sun, Xing; Yan, Dongwang; Huang, Jianfeng; Luo, Qiongzhen; Tang, Huamei; Peng, Zhihai

    2012-10-01

    Piwi-like protein 2 (Piwil2) has recently emerged as a putative oncogene which is amplified in several human malignancies. However, the role of Piwil2 in colon cancer remains poorly understood. The aim of this study was to investigate the clinical and pathological significance of Piwil2, and the possible role in the proliferation and metastasis of colon cancer. Primary colon cancer paired with adjacent normal colon tissue and lymph node metastasis (LNM) lesions in 66 patients' tissue microarrays (TMA) were used to determine the expression of Piwil2. Knocked down Piwil2 expression in SW620 and SW480 colon cancer cell lines was performed to evaluate the role of Piwil2 in cell proliferation, invasion, metastasis in vitro and tumorigenicity in vivo. The possible roles of Piwil2 in the regulation of a 2 kb matrix metallopeptidase 9 (MMP9) promoter fragment and on the regulation of apoptotic pathways were evaluated by using a luciferase reporter construct and Western blots, respectively. Significantly higher expression levels of Piwil2 were observed in primary colon cancer tissue and in LNM in comparison with normal colon mucosa. Piwil2 expression significantly correlated with more aggressive clinical and pathological parameters with poorer five-year metastasis-free survival and overall survival. Piwil2 silencing significantly reduced cancer cell proliferation, colony formation ability and increased apoptosis in vitro and inhibited tumor growth in vivo. Piwil2 knockdown also attenuated migration and invasion of colon cancer cells via modulation of MMP9 transcriptional activities. Our results indicate that Piwil2 moderates the proliferation and metastasis potential of colon cancer.

  10. Visible-light driven photocatalytic activity of β-indium sulfide (In2S3) quantum dots embedded in Nafion matrix

    NASA Astrophysics Data System (ADS)

    Sumi, R.; Warrier, Anita R.; Vijayan, C.

    2014-03-01

    We report on the visible-light-driven photocatalytic activity of highly stable β-indium sulfide (In2S3) quantum dots embedded in Nafion matrix. β-indium sulfide (In2S3) quantum dots (6-10 nm) embedded in Nafion matrix with strong quantum confinement were synthesized by a simple chemical route. The UV-Vis absorption spectrum shows a large blue shift (˜1 eV) which can be controlled by the reaction temperature and time. Strong broadband photoluminescence is observed in the blue, green and red regions of the emission spectrum with variation in particle size and stoichiometry of the quantum dots. Photocatalytic activity measurements show that these hybrid membranes synthesized with equimolar precursors of In and S show paramount photocatalytic activity under visible-light irradiation, with the degradation of Rhodamine-6G dyes up to 95% within 90 min. The photocatalytic membranes are tested for reusable and stable operation.

  11. Regulation of proteinases during mouse peri-implantation development: urokinase-type plasminogen activator expression and cross talk with matrix metalloproteinase 9.

    PubMed

    Martínez-Hernández, M G; Baiza-Gutman, L A; Castillo-Trápala, A; Armant, D Randall

    2011-02-01

    Trophoblast cells express urokinase-type plasminogen activator (PLAU) and may depend on its activity for endometrial invasion and tissue remodeling during peri-implantation development. However, the developmental regulation, tissue distribution, and function of PLAU are not completely understood. In this study, the expression of PLAU and its regulation by extracellular matrix proteins was examined by RT-PCR, immunocytochemistry, and plasminogen-casein zymography in cultured mouse embryos. There was a progressive increase in Plau mRNA expression in blastocysts cultured on gestation days 4-8. Tissue-type plasminogen activator (55 kDa) and PLAU (a triplet of 40, 37, and 31 kDa) were present in conditioned medium and embryo lysates, and were adsorbed to the culture plate surface. The temporal expression pattern of PLAU, according to semi-quantitative gel zymography, was similar in non-adhering embryos and embryos cultured on fibronectin, laminin, or type IV collagen, although type IV collagen and laminin upregulated Plau mRNA expression. Immunofluorescence revealed PLAU on the surface of the mural trophectoderm and in non-spreading giant trophoblast cells. Exogenous human plasminogen was transformed to plasmin by cultured embryos and activated endogenous matrix metalloproteinase 9 (MMP9). Indeed, the developmental expression profile of MMP9 was similar to that of PLAU. Our data suggest that the intrinsic developmental program predominantly regulates PLAU expression during implantation, and that PLAU could be responsible for activation of MMP9, leading to localized matrix proteolysis as trophoblast invasion commences.

  12. Spectrally narrowed leaky waveguide edge emission and transient electrluminescent dynamics of OLEDs

    SciTech Connect

    Zhengqing, Gan

    2010-01-01

    In summary, there are two major research works presented in this dissertation. The first research project (Chapter 4) is spectrally narrowed edge emission from Organic Light Emitting Diodes. The second project (Chapter 5) is about transient electroluminescent dynamics in OLEDs. Chapter 1 is a general introduction of OLEDs. Chapter 2 is a general introduction of organic semiconductor lasers. Chapter 3 is a description of the thermal evaporation method for OLED fabrication. The detail of the first project was presented in Chapter 4. Extremely narrowed spectrum was observed from the edge of OLED devices. A threshold thickness exists, above which the spectrum is narrow, and below which the spectrum is broad. The FWHM of spectrum depends on the material of the organic thin films, the thickness of the organic layers, and length of the OLED device. A superlinear relationship between the output intensity of the edge emission and the length of the device was observed, which is probably due to the misalignment of the device edge and the optical fiber detector. The original motivation of this research is for organic semiconductor laser that hasn't been realized due to the extremely high photon absorption in OLED devices. Although we didn't succeed in fabricating an electrically pumped organic laser diode, we made a comprehensive research in edge emission of OLEDs which provides valuable results in understanding light distribution and propagation in OLED devices. Chapter 5 focuses on the second project. A strong spike was observed at the falling edge of a pulse, and a long tail followed. The spike was due to the recombination of correlated charge pair (CCP) created by trapped carriers in guest molecules of the recombination zone. When the bias was turned off, along with the decreasing of electric field in the device, the electric field induced quenching decreases and the recombination rate of the CCP increases which result in the spike. This research project provides a

  13. Application of Developed APCVD Transparent Conducting Oxides and Undercoat Technologies for Economical OLED Lighting

    SciTech Connect

    Silverman, Gary S.; Bluhm, Martin; Coffey, James; Korotkov, Roman; Polsz, Craig; Salemi, Alexandre; Smith, Robert; Smith, Ryan; Stricker, Jeff; Xu, Chen; Shirazi, Jasmine; Papakonstantopulous, George; Carson, Steve; Hartmann, Sören; Jessen, Frank; Krogmann, Bianaca; Rickers, Christoph; Ruske, Manfred; Schwab, Holger; Bertram, Dietrich

    2011-01-02

    Economics is a key factor for application of organic light emitting diodes (OLED) in general lighting relative to OLED flat panel displays that can handle high cost materials such as indium tin oxide (ITO) or Indium zinc oxide (IZO) as the transparent conducting oxide (TCO) on display glass. However, for OLED lighting to penetrate into general illumination, economics and sustainable materials are critical. The issues with ITO have been documented at the DOE SSL R&D and Manufacturing workshops for the last 5 years and the issue is being exaserbated by export controls from China (one of the major sources of elemental indium). Therefore, ITO is not sustainable because of the fluctuating costs and the United States (US) dependency on other nations such as China. Numerous alternatives to ITO/IZO are being evaluated such as Ag nanoparticles/nanowires, carbon nanotubes, graphene, and other metal oxides. Of these other metal oxides, doped zinc oxide has attracted a lot of attention over the last 10 years. The volume of zinc mined is a factor of 80,000 greater than indium and the US has significant volumes of zinc mined domestically, resulting in the ability for the US to be self-sufficient for this element that can be used in optoelectonic applications. The costs of elemental zinc is over 2 orders of magnitude less than indium, reflecting the relative abundance and availablility of the elements. Arkema Inc. and an international primary glass manufacturing company, which is located in the United States, have developed doped zinc oxide technology for solar control windows. The genesis of this DOE SSL project was to determine if doped zinc oxide technology can be taken from the commodity based window market and translate the technology to OLED lighting. Thus, Arkema Inc. sought out experts, Philips Lighting, Pacific Northwest National Laboratories (PNNL) and National Renewable Research Laboratories (NREL), in OLED devices and brought them into the project. This project had a

  14. OLED-based physiologically-friendly very low-color temperature illumination for night

    NASA Astrophysics Data System (ADS)

    Jou, Jwo-Huei; Shen, Shih-Ming; Tang, Ming-Chun; Chen, Pin-Chu; Chen, Szu-Hao; Wang, Yi-Shan; Chen, Chien-Chih; Wang, Ching-Chun; Hsieh, Chun-Yu; Lin, Chin-Chiao; Chen, Chien-Tien

    2012-09-01

    Numerous medical research studies reveal intense white or blue light to drastically suppress at night the secretion of melatonin (MLT), a protective oncostatic hormone. Lighting devices with lower color-temperature (CT) possess lesser MLT suppression effect based on the same luminance, explaining why physicians have long been calling for the development of lighting sources with low CT or free from blue emission for use at night to safeguard human health. We will demonstrate in the presentation the fabrication of OLED devices with very-low CT, especially those with CT much lower than that of incandescent bulbs (2500K) or even candles (2000K). Without any light extraction method, OLEDs with an around 1800K CT are easily obtainable with an efficacy of 30 lm/W at 1,000 nits. To also ensure high color-rendering to provide visual comfort, low CT OLEDs composing long wavelength dominant 5-spectrum emission have been fabricated. While keeping the color-rendering index as high as 85 and CT as low as 2100K, the resulting efficacy can also be much greater than that of incandescent bulbs (15 lm/W), proving these low CT OLED devices to be also capable of being energy-saving and high quality. The color-temperature can be further decreased to 1700K or lower upon removing the undesired short wavelength emission but on the cost of losing some color rendering index. It is hoped that the devised energy-saving, high quality low CT OLED could properly echo the call for a physiologically-friendly illumination for night, and more attention could be drawn to the development of MLT suppression-less non-white light.

  15. Improved designs for p-i-n OLEDs towards the minimal power loss of devices

    NASA Astrophysics Data System (ADS)

    Qin, Dashan

    2014-05-01

    Currently, the low yield, high power loss, and poor stability of organic light emitting diodes (OLEDs) panels are remaining as the obstacles to the fast growth of the OLED industry, especially for the lighting application. The p-i-n OLEDs have been widely recognized as the promising method to circumvent these bottleneck factors, due to the unique merit of the electrical doping to enable low power loss. In p-i-n OLEDs, the frequently used n-doped electron transport layers (n-ETL1) such as n-BCP, n-Alq3 possess markedly lower conductivities but better capabilities of injecting electrons into ETL such as BCP, Alq3, as compared to another class of n-doped ETLs (n-ETL2), e.g., n-NTCDA, n-PTCDA, n-C60. Thus, in order to minimize the electron loss, we provide the structure of uniting two n-doped layers, cathode/ n-ETL2/ n-ETL1/ ETL. In p-i-n OLEDs, the hole current injected from the single p-doped hole transport layer (p-HTL) into the neat HTL must be limited, because the higher conductivity p-HTL has the higher lying highest occupied molecular orbital (HOMO) level, leading to a larger hole transport energy barrier (φB) at the interface with the neat HTL. Therefore, in order to minimize the hole loss, we suggest the structure of uniting two p-HTLs, anode/ p-HTL2/ p-HTL1/ HTL. The p-HTL2 possesses high-lying HOMO level and thereby high conductivity, decreasing the ohmic loss in the hole conduction; the p-HTL1 features a low-lying HOMO level, reducing the φB.

  16. Electron mobility characterization in OLEDs from ac small signal optical modulation

    NASA Astrophysics Data System (ADS)

    Mu, Haichuan; Reddy, Indrani; Hunt, John; Severs, Phillip; Patil, Shirish

    2010-05-01

    This paper investigates the field dependence of electron mobility in tris(8-hydroxyquinolinato)aluminium (Alq3) and bathocuproine (BCP) through ac small signal optical modulation on green light (ITO/PEDOT/NPD/Alq3/Ba/Ag) and blue light (ITO/PEDOT/NPD/BCP/Alq3/Ba/Ag) OLED. The electroluminescence (EL) transient time delay for the blue light OLED is much longer than for the green one. The electron mobility in BCP was extracted based on a Poole-Frenkel-like equation and EL transient time delay measurement, which is in the range (7-9) × 10-8 cm2 V-1 s-1 at an external electric field of 1530-1830 (V cm-1)1/2, comparable to the results from other published reports (Muckl et al 2000 Synth. Met. 111-112 91; Barth et al 2001 J. Appl. Phys. 89 3711; Nakamura H et al 1996 Int. Symp. on Inorganic and Organic Electroluminescence ed R H Mauch and H-E Gumlich (Berlin: Wissenschaft und Technik) p 95; Xie et al 2002 Appl. Phys. Lett. 80 1477). The difference in EL transient time delay and electron mobility for green and blue light OLEDs was demonstrated by the results of direct modulation. The electron transit time shows similar field dependence in both Alq3 layers in green and blue OLEDs. Unlike Alq3, the field dependence of electron mobility in BCP did not fit the conventional organic semiconductor characteristics μ∞exp(βE1/2), and the excitons formation at the NPD/BCP interface for the blue OLEDs was demonstrated through the EL spectrum.

  17. The effect of drugs commonly used in the treatment of equine articular disorders on the activity of equine matrix metalloproteinase-2 and 9.

    PubMed

    Clegg, P D; Jones, M D; Carter, S D

    1998-10-01

    Loss of articular cartilage, which is the most important pathological lesion occurring in osteoarthritis, has been shown to be enzymatically mediated. The matrix metalloproteinases (MMPs) are a group of enzymes which have been implicated in this degradation of articular cartilage matrix. The use of pharmacological agents to inhibit this catabolic process in the joint is a potential route for therapeutic intervention. The gelatinase MMPs, MMPs-2 and 9, were purified by affinity chromatography from equine cell cultures. The ability of phenylbutazone, flunixin, betamethasone, dexamethasone, methylprednisolone acetate (MPA), hyaluronan, pentosan polysulphate and polysulphated glycosaminoglycan (PSGAG) to inhibit equine MMPs-2 and 9 were assessed by two degradation assays. Whilst some agents did have direct effects on MMP activity, these effects were only obtained at concentrations which were unlikely to be achieved for any length of time in vivo. It is improbable that any pharmacological agent, currently used in the horse, has a significant effect on gelatinase MMP activity.

  18. Occurrence of matrix-bound phosphine in polar ornithogenic tundra ecosystems: effects of alkaline phosphatase activity and environmental variables.

    PubMed

    Zhu, Renbin; Ma, Dawei; Ding, Wei; Bai, Bo; Liu, Yashu; Sun, Jianjun

    2011-09-01

    Phosphine (PH(3)), a reduced phosphorus compound, is a highly toxic and reactive atmospheric trace gas. In this study, a total of ten ornithogenic soil/sediment profiles were collected from tundra ecosystems of east Antarctica and Arctic, and matrix-bound phosphine (MBP), the phosphorus fractions and alkaline phosphatase activity (APA) were analyzed. High MBP concentrations were found in these profiles with the range from 39.59 ng kg(-1) dw to 11.77 μg kg(-1) dw. MBP showed a consistent vertical distribution pattern in almost all the soil profiles, and its concentrations increased at soil surface layers and then decreased with depths. MBP levels in the ornithogenic soils were two to three orders of magnitude lower than those in ornithogenic sediments. The yield of PH(3) as a fraction of total P in all the profiles ranged from 10(-5) to 10(-9) mgPH(3) mg(-1)P with higher mean PH(3) yield in the ornithogenic sediments. The ornithogenic soils showed high concentrations of total phosphorus (TP), organic phosphorus (OP), inorganic phosphorus (IP) and metal elements (Cu, Zn, Mn, Fe, Al and Ca) but low MBP levels, vice versa for the ornithogenic sediments. No correlation had been obtained between MBP concentrations and IP, OP and TP. There existed an exponential correlation (r=0.67, p<0.01) between MBP and soil/sediment moisture. MBP concentrations showed a significant positive correlation with APA (r=0.668, p<0.0001), total organic carbon (r=0.501, p<0.0001), total hydrogen (r=0.483, p<0.0001) and total sulfur (r=0.398, p<0.001), indicating that the production of MBP is associated with microbially mediated factors rather than the contents of TP, IP and OP in the P-enriched ornithogenic soils/sediments. Our results indicated that MBP is an important gaseous link in the phosphorus biogeochemical cycles of ornithogenic tundra ecosystems in Antarctica and Arctic.

  19. Non-selective distribution of isomeric cholesterol hydroperoxides to microdomains in cell membranes and activation of matrix metalloproteinase activity in a model of dermal cells.

    PubMed

    Nakamura, Toshiyuki; Noma, Ayako; Shimada, Sachiko; Ishii, Nanase; Bando, Noriko; Kawai, Yoshichika; Terao, Junji

    2013-09-01

    Cholesterol hydroperoxides (ChOOHs) are included as lipid peroxidation products in the skin exposed to ultraviolet (UV) light irradiation. They may exert physicochemical actions affecting biomembrane rigidity because cholesterol is one of the major components of cell membranes. We investigated the distribution of isomeric ChOOHs in heterogeneous cell membranes with different lipid profiles using mouse fibroblast NIH-3T3 cells as a model of the dermis. Before and after UVA irradiation in the presence of hematoporphyrin, cell membranes were partitioned to microdomains (lipid rafts and caveolae) containing a higher amount of cholesterol and non-microdomains (containing a lower amount of cholesterol) by ultracentrifugation. By a combination of diphenylpyrenylphosphine-thin-layer chromatography blotting analyses and gas chromatography-electron ionization-mass spectrometry/selected ion monitoring analyses, ChOOH isomers were determined as their trimethylsilyloxyl derivatives. Cholesterol 5α-, 7α- and 7β-hydroperoxide were found as isomeric ChOOHs before irradiation. The amounts of the three ChOOH isomers increased significantly after photoirradiation for 2h. No difference was observed between microdomains and non-microdomains with regard to the ratio of the amounts of isomeric ChOOHs to that of cholesterol, suggesting that these ChOOH isomers were distributed equally in both parts depending on cholesterol content. When cells were treated with a purified mixture of ChOOH isomers, cell membranes incorporated ChOOHs into microdomains as well as non-microdomains evenly. Cellular matrix metalloproteinase-9 (MMP-9) activity was elevated by treatment with the purified mixture of ChOOH isomers. These results strongly suggest that ChOOHs accumulate in cell membranes irrespective of the heterogeneous microstructure and promote MMP activity if dermal cells are exposed to photodynamic actions.

  20. Capillary-induced Homogenization of Matrix in Paper: A Powerful Approach for the Quantification of Active Pharmaceutical Ingredients Using Mass Spectrometry Imaging

    NASA Astrophysics Data System (ADS)

    de Menezes, Maico; de Oliveira, Diogo Noin; Catharino, Rodrigo Ramos

    2016-07-01

    Herein we present a novel approach for the quantification of active pharmaceutical ingredients (APIs) using mass spectrometry imaging. This strategy uses a filter paper previously “eluted” with a MALDI matrix solution as a support for analyte application. Samples are submitted to mass spectrometry imaging (MSI) and quantification through characteristic fingerprints is ultimately performed. Results for the content of rosuvastatin from a known formulation are comparable to those obtained with a validated HPLC method.

  1. MT1-MMP promotes cell growth and ERK activation through c-Src and paxillin in three-dimensional collagen matrix

    SciTech Connect

    Takino, Takahisa; Tsuge, Hisashi; Ozawa, Terumasa; Sato, Hiroshi

    2010-06-11

    Membrane-type 1 matrix metalloproteinase (MT1-MMP) is essential for tumor invasion and growth. We show here that MT1-MMP induces extracellular signal-regulated kinase (ERK) activation in cancer cells cultured in collagen gel, which is indispensable for their proliferation. Inhibition of MT1-MMP by MMP inhibitor or small interfering RNA suppressed activation of focal adhesion kinase (FAK) and ERK in MT1-MMP-expressing cancer cells, which resulted in up-regulation of p21{sup WAF1} and suppression of cell growth in collagen gel. Cell proliferation was also abrogated by the inhibitor against ERK pathway without affecting FAK phosphorylation. MT1-MMP and integrin {alpha}{sub v}{beta}{sub 3} were shown to be involved in c-Src activation, which induced FAK and ERK activation in collagen gel. These MT1-MMP-mediated signal transductions were paxillin dependent, as knockdown of paxillin reduced cell growth and ERK activation, and co-expression of MT1-MMP with paxillin induced ERK activation. The results suggest that MT1-MMP contributes to proliferation of cancer cells in the extracellular matrix by activating ERK through c-Src and paxillin.

  2. Metal-organic framework-derived bamboo-like nitrogen-doped graphene tubes as an active matrix for hybrid oxygen-reduction electrocatalysts.

    PubMed

    Li, Qing; Pan, Hengyu; Higgins, Drew; Cao, Ruiguo; Zhang, Guoqi; Lv, Haifeng; Wu, Kangbing; Cho, Jaephil; Wu, Gang

    2015-03-25

    In this work, large size (i.e., diameter > 100 nm) graphene tubes with nitrogen-doping are prepared through a high-temperature graphitization process of dicyandiamide (DCDA) and Iron(II) acetate templated by a novel metal-organic framework (MIL-100(Fe)). The nitrogen-doped graphene tube (N-GT)-rich iron-nitrogen-carbon (Fe-N-C) catalysts exhibit inherently high activity towards the oxygen reduction reaction (ORR) in more challenging acidic media. Furthermore, aiming to improve the activity and stability of conventional Pt catalysts, the ORR active N-GT is used as a matrix to disperse Pt nanoparticles in order to build a unique hybrid Pt cathode catalyst. This is the first demonstration of the integration of a highly active Fe-N-C catalyst with Pt nanoparticles. The synthesized 20% Pt/N-GT composite catalysts demonstrate significantly enhanced ORR activity and H(2) -air fuel cell performance relative to those of 20% Pt/C, which is mainly attributed to the intrinsically active N-GT matrix along with possible synergistic effects between the non-precious metal active sites and the Pt nanoparticles. Unlike traditional Pt/C, the hybrid catalysts exhibit excellent stability during the accelerated durability testing, likely due to the unique highly graphitized graphene tube morphologies, capable of providing strong interaction with Pt nanoparticles and then preventing their agglomeration.

  3. Induction of tissue inhibitor of matrix metalloproteinase-2 by cholesterol depletion leads to the conversion of proMMP-2 into active MMP-2 in human dermal fibroblasts

    PubMed Central

    Kim, Sangmin; Oh, Jang-Hee; Lee, Youngae; Lee, Jeongyoon; Cho, Kwang Hyun

    2010-01-01

    Cholesterol is one of major components of cell membrane and plays a role in vesicular trafficking and cellular signaling. We investigated the effects of cholesterol on matrix metalloproteinase-2 (MMP-2) activation in human dermal fibroblasts. We found that tissue inhibitor of matrix metalloproteinase-2 (TIMP-2) expression and active form MMP-2 (64 kD) were dose-dependently increased by methyl-β-cyclodextrin (MβCD), a cholesterol depletion agent. In contrast, cholesterol depletion-induced TIMP-2 expression and MMP-2 activation were suppressed by cholesterol repletion. Then we investigated the regulatory mechanism of TIMP-2 expression by cholesterol depletion. We found that the phosphorylation of JNK as well as ERK was significantly increased by cholesterol depletion. Moreover, cholesterol depletion-induced TIMP-2 expression and MMP-2 activation was significantly decreased by MEK inhibitor U0126, and JNK inhibitor SP600125, respectively. While a low dose of recombinant TIMP-2 (100 ng/ml) increased the level of active MMP-2 (64 kD), the high dose of TIMP-2 (≥ 200 ng/ml) decreased the level of active MMP-2 (64 kD). Taken together, we suggest that the induction of TIMP-2 by cholesterol depletion leads to the conversion of proMMP-2 (72 kD) into active MMP-2 (64 kD) in human dermal fibroblasts. PMID:19887895

  4. The Extracellular Protease Matrix Metalloproteinase-9 Is Activated by Inhibitory Avoidance Learning and Required for Long-Term Memory

    ERIC Educational Resources Information Center

    Nagy, Vanja; Bozdagi, Ozlem; Huntley, George W.

    2007-01-01

    Matrix metalloproteinases (MMPs) are a family of extracellularly acting proteolytic enzymes with well-recognized roles in plasticity and remodeling of synaptic circuits during brain development and following brain injury. However, it is now becoming increasingly apparent that MMPs also function in normal, nonpathological synaptic plasticity of the…

  5. A Cannabinoid Receptor 2 Agonist Prevents Thrombin-Induced Blood-Brain Barrier Damage via the Inhibition of Microglial Activation and Matrix Metalloproteinase Expression in Rats.

    PubMed

    Li, Lin; Tao, Yihao; Tang, Jun; Chen, Qianwei; Yang, Yang; Feng, Zhou; Chen, Yujie; Yang, Liming; Yang, Yunfeng; Zhu, Gang; Feng, Hua; Chen, Zhi

    2015-12-01

    Thrombin mediates the life-threatening cerebral edema and blood-brain barrier (BBB) damage that occurs after intracerebral hemorrhage (ICH). We previously found that the selective cannabinoid receptor 2 (CB2R) agonist JWH-133 reduced brain edema and neurological deficits following germinal matrix hemorrhage (GMH). We explored whether CB2R stimulation ameliorated thrombin-induced brain edema and BBB permeability as well as the possible molecular mechanism involved. A total of 144 Sprague-Dawley (S-D) rats received a thrombin (20 U) injection in the right basal ganglia. JWH-133 (1.5 mg/kg) or SR-144528 (3.0 mg/kg) and vehicle were intraperitoneally (i.p.) injected 1 h after surgery. Brain water content measurement, Evans blue (EB) extravasation, Western blot, and immunofluorescence were used to study the effects of a CB2R agonist 24 h after surgery. The results demonstrated that JWH-133 administration significantly decreased thrombin-induced brain edema and reduced the number of Iba-1-positive microglia. JWH-133 also decreased the number of P44/P42(+)/Iba-1(+) microglia, lowered Evans blue extravasation, and inhibited the elevated matrix metallopeptidase (MMP)-9 and matrix metallopeptidase (MMP)-12 activities. However, a selective CB2R antagonist (SR-144528) reversed these effects. We demonstrated that CB2R stimulation reduced thrombin-induced brain edema and alleviated BBB damage. We also found that matrix metalloproteinase suppression may be partially involved in these processes.

  6. Fully Screen-Printed, Large-Area, and Flexible Active-Matrix Electrochromic Displays Using Carbon Nanotube Thin-Film Transistors.

    PubMed

    Cao, Xuan; Lau, Christian; Liu, Yihang; Wu, Fanqi; Gui, Hui; Liu, Qingzhou; Ma, Yuqiang; Wan, Haochuan; Amer, Moh R; Zhou, Chongwu

    2016-11-22

    Semiconducting single-wall carbon nanotubes are ideal semiconductors for printed electronics due to their advantageous electrical and mechanical properties, intrinsic printability in solution, and desirable stability in air. However, fully printed, large-area, high-performance, and flexible carbon nanotube active-matrix backplanes are still difficult to realize for future displays and sensing applications. Here, we report fully screen-printed active-matrix electrochromic displays employing carbon nanotube thin-film transistors. Our fully printed backplane shows high electrical performance with mobility of 3.92 ± 1.08 cm(2) V(-1) s(-1), on-off current ratio Ion/Ioff ∼ 10(4), and good uniformity. The printed backplane was then monolithically integrated with an array of printed electrochromic pixels, resulting in an entirely screen-printed active-matrix electrochromic display (AMECD) with good switching characteristics, facile manufacturing, and long-term stability. Overall, our fully screen-printed AMECD is promising for the mass production of large-area and low-cost flexible displays for applications such as disposable tags, medical electronics, and smart home appliances.

  7. Solution-Processable Transparent Conductive Hole Injection Electrode for OLED SSL

    SciTech Connect

    Pschenitzka, Florian; Mathai, Mathew; Torke, Terri

    2012-07-15

    An interconnected network of silver nanowires has been used as transparent anode in OLED devices. This layer was deposited by spin-coating and slot-die coating from an aqueous nanowire suspension. The sheet resistance of the film was 10ohms/sq with a transmission (including the glass substrate) of higher than 85%. The first phase of the project focused on the implementation of this nanowire layer with a hole-injection-layer (HIL) which has been developed at Plextronics and has been shown to provide good stability and efficiency in conventional OLED devices. We modified the HIL solution such that it coated reasonably well with suitable surface morphology so that actual devices can be manufactured. During the second phase we investigated the hole-injection and stability of hole-onlydevices. We determined that the use of the nanowire network as anode does not introduce an additional degradation mechanism since the observed device characteristics did not differ from those made with ITO anode. We then proceeded to make actual OLED devices with this nanowire / HIL stack and achieved device characteristics similar state-of-the-art OLED devices with a single junction. In order to gain traction with potential OLED manufacturers, we decided to contract Novaled to prepare large-area demonstrators for us. For these devices, we used an allevaporated stack, i.e. we did use Novaled's HIL material instead of Plextronics. We successfully fabricated demonstrators with an area of 25cm2 with a double or triple junction stack. Minor stack optimizations were necessary to achieve efficacies and lifetime equivalent with ITO devices made with the same devices stack. Due to the reduced microcavity effect, the color of the emitted light is significantly more stable with respect to the viewing angle compared to ITO devices. This fact in conjunction with the promise of lower production cost due to the elimination of the ITO sputtering process and the direct patterning of the anode layer are

  8. Betulin suppressed interleukin-1β-induced gene expression, secretion and proteolytic activity of matrix metalloproteinase in cultured articular chondrocytes and production of matrix metalloproteinase in the knee joint of rat

    PubMed Central

    Ra, Ho Jong; Lee, Hyun Jae; Jo, Ho Seung; Nam, Dae Cheol; Lee, Young Bok; Kang, Byeong Hun; Moon, Dong Kyu; Kim, Dong Hee

    2017-01-01

    We investigated whether betulin affects the gene expression, secretion and proteolytic activity of matrix metalloproteinase-3 (MMP-3) in primary cultured rabbit articular chondrocytes, as well as in vivo production of MMP-3 in the rat knee joint to evaluate the potential chondroprotective effect of betulin. Rabbit articular chondrocytes were cultured and reverse transcription-polymerase chain reaction (RT-PCR) was used to measure interleukin-1β (IL-1β)-induced gene expression of MMP-3, MMP-1, MMP-13, a disintegrin and metalloproteinase with thrombospondin motifs-4 (ADAMTS-4), ADAMTS-5 and type II collagen. Effect of betulin on IL-1β-induced secretion and proteolytic activity of MMP-3 was investigated using western blot analysis and casein zymography, respectively. Effect of betulin on MMP-3 protein production was also examined in vivo. The results were as follows: (1) betulin inhibited the gene expression of MMP-3, MMP-1, MMP-13, ADAMTS-4, and ADAMTS-5, but increased the gene expression of type II collagen; (2) betulin inhibited the secretion and proteolytic activity of MMP-3; (3) betulin suppressed the production of MMP-3 protein in vivo. These results suggest that betulin can regulate the gene expression, secretion, and proteolytic activity of MMP-3, by directly acting on articular chondrocytes. PMID:28066137

  9. Effect of oleanolic acid on the activity, secretion and gene expression of matrix metalloproteinase-3 in articular chondrocytes in vitro and the production of matrix metalloproteinase-3 in vivo

    PubMed Central

    Kang, Dong-Geun; Lee, Hyun Jae; Kim, Kun Tae; Hwang, Sun-Chul

    2017-01-01

    In the present study, we tried to examine whether oleanolic acid regulates the activity, secretion and gene expression of matrix metalloproteinase-3 (MMP-3) in primary cultured rabbit articular chondrocytes, as well as the production of MMP-3 in the knee joint of rat to evaluate the potential chondroprotective effect of oleanolic acid. Rabbit articular chondrocytes were cultured in a monolayer, and reverse transcription-polymerase chain reaction (RT-PCR) was used to measure interleukin-1β (IL-1β)-induced gene expression of MMP-3, MMP-1, MMP-13, a disintegrin and metalloproteinase with thrombospondin motifs-4 (ADAMTS-4), ADAMTS-5 and type II collagen. In rabbit articular chondrocytes, the effects of oleanolic acid on IL-1β-induced secretion and proteolytic activity of MMP-3 were investigated using western blot analysis and casein zymography, respectively. The effect of oleanolic acid on in vivo MMP-3 protein production was also examined, after intra-articular injection to the knee joint of rat. The results were as follows: (1) oleanolic acid inhibited the gene expression of MMP-3, MMP-1, MMP-13, ADAMTS-4, and ADAMTS-5, but increased the gene expression of type II collagen; (2) oleanolic acid reduced the secretion and proteolytic activity of MMP-3; (3) oleanolic acid suppressed the production of MMP-3 protein in vivo. These results suggest that oleanolic acid can regulate the activity, secretion and gene expression of MMP-3, by directly acting on articular chondrocytes. PMID:28280413

  10. Betulin suppressed interleukin-1β-induced gene expression, secretion and proteolytic activity of matrix metalloproteinase in cultured articular chondrocytes and production of matrix metalloproteinase in the knee joint of rat.

    PubMed

    Ra, Ho Jong; Lee, Hyun Jae; Jo, Ho Seung; Nam, Dae Cheol; Lee, Young Bok; Kang, Byeong Hun; Moon, Dong Kyu; Kim, Dong Hee; Lee, Choong Jae; Hwang, Sun-Chul

    2017-01-01

    We investigated whether betulin affects the gene expression, secretion and proteolytic activity of matrix metalloproteinase-3 (MMP-3) in primary cultured rabbit articular chondrocytes, as well as in vivo production of MMP-3 in the rat knee joint to evaluate the potential chondroprotective effect of betulin. Rabbit articular chondrocytes were cultured and reverse transcription-polymerase chain reaction (RT-PCR) was used to measure interleukin-1β (IL-1β)-induced gene expression of MMP-3, MMP-1, MMP-13, a disintegrin and metalloproteinase with thrombospondin motifs-4 (ADAMTS-4), ADAMTS-5 and type II collagen. Effect of betulin on IL-1β-induced secretion and proteolytic activity of MMP-3 was investigated using western blot analysis and casein zymography, respectively. Effect of betulin on MMP-3 protein production was also examined in vivo. The results were as follows: (1) betulin inhibited the gene expression of MMP-3, MMP-1, MMP-13, ADAMTS-4, and ADAMTS-5, but increased the gene expression of type II collagen; (2) betulin inhibited the secretion and proteolytic activity of MMP-3; (3) betulin suppressed the production of MMP-3 protein in vivo. These results suggest that betulin can regulate the gene expression, secretion, and proteolytic activity of MMP-3, by directly acting on articular chondrocytes.

  11. Electrical features of an amorphous indium-gallium-zinc-oxide film transistor using a double active matrix with different oxygen contents

    NASA Astrophysics Data System (ADS)

    Koo, Ja Hyun; Kang, Tae Sung; Hong, Jin Pyo

    2012-05-01

    The electrical characteristics of amorphous indium-gallium-zinc-oxide (a-IGZO) thin film transistors (TFTs) are systematically studied using a double a-IGZO active layer that is composed of a-IGZO x (oxygen-ion-poor region) and a-IGZO y (oxygen-ion-rich-region). An active layer is designed to have a serially-stacked bi-layer matrix with different oxygen contents, providing the formation of different electron conduction channels. Two different oxygen contents in the active layer are obtained by varying the O2 partial pressure during sputtering. The a-IGZO TFT based on a double active layer exhibits a high mobility of 9.1 cm2/Vsec, a threshold voltage (V T ) of 16.5 V, and ΔV T shifts of less than 1.5 V under gate voltage stress. A possible electrical sketch for the double active layer channel is also discussed.

  12. Matrix thermalization

    NASA Astrophysics Data System (ADS)

    Craps, Ben; Evnin, Oleg; Nguyen, Kévin

    2017-02-01

    Matrix quantum mechanics offers an attractive environment for discussing gravitational holography, in which both sides of the holographic duality are well-defined. Similarly to higher-dimensional implementations of holography, collapsing shell solutions in the gravitational bulk correspond in this setting to thermalization processes in the dual quantum mechanical theory. We construct an explicit, fully nonlinear supergravity solution describing a generic collapsing dilaton shell, specify the holographic renormalization prescriptions necessary for computing the relevant boundary observables, and apply them to evaluating thermalizing two-point correlation functions in the dual matrix theory.

  13. Gel structure has an impact on pericellular and extracellular matrix deposition, which subsequently alters metabolic activities in chondrocyte-laden PEG hydrogels.

    PubMed

    Nicodemus, G D; Skaalure, S C; Bryant, S J

    2011-02-01

    While designing poly(ethylene glycol) hydrogels with high moduli suitable for in situ placement is attractive for cartilage regeneration, the impact of a tighter crosslinked structure on the organization and deposition of the matrix is not fully understood. The objectives of this study were to characterize the composition and spatial organization of new matrix as a function of gel crosslinking and study its impact on chondrocytes in terms of anabolic and catabolic gene expression and catabolic activity. Bovine articular chondrocytes were encapsulated in hydrogels with three crosslinking densities (compressive moduli 60, 320 and 590 kPa) and cultured for 25 days. Glycosaminoglycan production increased with culture time and was greatest in the gels with lowest crosslinking. Collagens II and VI, aggrecan, link protein and decorin were localized to pericellular regions in all gels, but their presence decreased with increasing gel crosslinking. Collagen II and aggrecan expression were initially up-regulated in gels with higher crosslinking, but increased similarly up to day 15. Matrix metalloproteinase (MMP)-1 and MMP-13 expression were elevated (∼25-fold) in gels with higher crosslinking throughout the study, while MMP-3 was unaffected by gel crosslinking. The presence of aggrecan and collagen degradation products confirmed MMP activity. These findings indicate that chondrocytes synthesized the major cartilage components within PEG hydrogels, however, gel structure had a significant impact on the composition and spatial organization of the new tissue and on how chondrocytes responded to their environment, particularly with respect to their catabolic expression.

  14. Activity concentration measurements of 137Cs, 90Sr and 40K in a wild food matrix reference material (Wild Berries) CCRI(II)-S8

    NASA Astrophysics Data System (ADS)

    Wätjen, U.; Altzitzogloa, T.; Ceccatelli, A.; Dikmen, H.; Ferreux, L.; Frechou, C.; García, L.; Gündogdu, G.; Kis-Benedek, G.; La Rosa, J.; Luca, A.; Moreno, Y.; Oropesa, P.; Pierre, S.; Schmiedel, M.; Spasova, Y.; Szücs, L.; Vasile, M.; Wershofen, H.; Yücel, Ü.

    2014-01-01

    In 2009, the CCRI approved a supplementary comparison to be organized by the IRMM as pilot laboratory for the activity concentrations of 137Cs, 90Sr and 40K in a matrix material of dried bilberries. The organization of this comparison and the material and measurement methods used are described. The supplementary comparison reference values (SCRV) for each of the three radionuclides are given together with the degrees of equivalence of each participating laboratory with the SCRV for the specific radionuclide. The results of this supplementary comparison allow the participating NMIs/designated institutes to declare calibration and measurement capabilities (CMCs) for the given radionuclides in a similar type of food matrix, an important aspect given the relatively few supplementary comparisons for activity in matrix materials organized so far. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCRI, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

  15. Metal Ion-dependent Heavy Chain Transfer Activity of TSG-6 Mediates Assembly of the Cumulus-Oocyte Matrix*

    PubMed Central

    Briggs, David C.; Birchenough, Holly L.; Ali, Tariq; Rugg, Marilyn S.; Waltho, Jon P.; Ievoli, Elena; Jowitt, Thomas A.; Enghild, Jan J.; Richter, Ralf P.; Salustri, Antonietta; Milner, Caroline M.; Day, Anthony J.

    2015-01-01

    The matrix polysaccharide hyaluronan (HA) has a critical role in the expansion of the cumulus cell-oocyte complex (COC), a process that is necessary for ovulation and fertilization in most mammals. Hyaluronan is organized into a cross-linked network by the cooperative action of three proteins, inter-α-inhibitor (IαI), pentraxin-3, and TNF-stimulated gene-6 (TSG-6), driving the expansion of the COC and providing the cumulus matrix with its required viscoelastic properties. Although it is known that matrix stabilization involves the TSG-6-mediated transfer of IαI heavy chains (HCs) onto hyaluronan (to form covalent HC·HA complexes that are cross-linked by pentraxin-3) and that this occurs via the formation of covalent HC·TSG-6 intermediates, the underlying molecular mechanisms are not well understood. Here, we have determined the tertiary structure of the CUB module from human TSG-6, identifying a calcium ion-binding site and chelating glutamic acid residue that mediate the formation of HC·TSG-6. This occurs via an initial metal ion-dependent, non-covalent, interaction between TSG-6 and HCs that also requires the presence of an HC-associated magnesium ion. In addition, we have found that the well characterized hyaluronan-binding site in the TSG-6 Link module is not used for recognition during transfer of HCs onto HA. Analysis of TSG-6 mutants (with impaired transferase and/or hyaluronan-binding functions) revealed that although the TSG-6-mediated formation of HC·HA complexes is essential for the expansion of mouse COCs in vitro, the hyaluronan-binding function of TSG-6 does not play a major role in the stabilization of the murine cumulus matrix. PMID:26468290

  16. Benzobisoxazole cruciforms: A tunable, cross-conjugated platform for the generation of deep blue OLED materials

    SciTech Connect

    Chavez, III, Ramiro; Cai, Min; Tlach, Brian; Wheeler, David L.; Kaudal, Rajiv; Tsyrenova, Ayuna; Tomlinson, Aimee L.; Shinar, Ruth; Shinar, Joseph; Jeffries-EL, Malika

    2016-01-20

    Four new cross-conjugated small molecules based on a central benzo[1,2-d:4,5-d']bisoxazole moiety possessing semi-independently tunable HOMO and LUMO levels were synthesized and the properties of these materials were evaluated experimentally and theoretically. The molecules were thermally stable with 5% weight loss occurring well above 350 °C. The cruciforms all exhibited blue emission in solution ranging from 433–450 nm. Host–guest OLEDs fabricated from various concentrations of these materials using the small molecule host 4,4'-bis(9-carbazolyl)-biphenyl (CBP) exhibited deep blue-emission with Commission Internationale de L'Eclairage (CIE) coordinates of (0.15 ≤ x ≤ 0.17, 0.05 ≤ y ≤ 0.11), and maximum luminance efficiencies as high as ~2 cd A–1. Lastly, these results demonstrate the potential of benzobisoxazole cruciforms as emitters for developing high-performance deep blue OLEDs.

  17. High-throughput quantum chemistry and virtual screening for OLED material components

    NASA Astrophysics Data System (ADS)

    Halls, Mathew D.; Giesen, David J.; Hughes, Thomas F.; Goldberg, Alexander; Cao, Yixiang

    2013-09-01

    Computational structure enumeration, analysis using an automated simulation workflow and filtering of large chemical structure libraries to identify lead systems, has become a central paradigm in drug discovery research. Transferring this paradigm to challenges in materials science is now possible due to advances in the speed of computational resources and the efficiency and stability of chemical simulation packages. State-of-the-art software tools that have been developed for drug discovery can be applied to efficiently explore the chemical design space to identify solutions for problems such as organic light-emitting diode material components. In this work, virtual screening for OLED materials based on intrinsic quantum mechanical properties is illustrated. Also, a new approach to more reliably identify candidate systems is introduced that is based on the chemical reaction energetics of defect pathways for OLED materials.

  18. Stacked white OLED having separate red, green and blue sub-elements

    DOEpatents

    Forrest, Stephen; Qi, Xiangfei; Slootsky, Michael

    2014-07-01

    The present invention relates to efficient organic light emitting devices (OLEDs). The devices employ three emissive sub-elements, typically emitting red, green and blue, to sufficiently cover the visible spectrum. Thus, the devices may be white-emitting OLEDs, or WOLEDs. Each sub-element comprises at least one organic layer which is an emissive layer--i.e., the layer is capable of emitting light when a voltage is applied across the stacked device. The sub-elements are vertically stacked and are separated by charge generating layers. The charge-generating layers are layers that inject charge carriers into the adjacent layer(s) but do not have a direct external connection.

  19. Spontaneous Fluctuations of Transition Dipole Moment Orientation in OLED Triplet Emitters.

    PubMed

    Steiner, Florian; Bange, Sebastian; Vogelsang, Jan; Lupton, John M

    2015-03-19

    The efficiency of an organic light-emitting diode (OLED) depends on the microscopic orientation of transition dipole moments of the molecular emitters. The most effective materials used for light generation have 3-fold symmetry, which prohibits a priori determination of dipole orientation due to the degeneracy of the fundamental transition. Single-molecule spectroscopy reveals that the model triplet emitter tris(1-phenylisoquinoline)iridium(III) (Ir(piq)3) does not behave as a linear dipole, radiating with lower polarization anisotropy than expected. Spontaneous symmetry breaking occurs in the excited state, leading to a random selection of one of the three ligands to form a charge-transfer state with the metal. This nondeterministic localization is revealed in switching of the degree of linear polarization of phosphorescence. Polarization scrambling likely raises out-coupling efficiency and should be taken into account when deriving molecular orientation of the guest emitter within the OLED host from ensemble angular emission profiles.

  20. An inconvenient influence of iridium(III) isomer on OLED efficiency.

    PubMed

    Baranoff, Etienne; Bolink, Henk J; De Angelis, Filippo; Fantacci, Simona; Di Censo, Davide; Djellab, Karim; Grätzel, Michael; Nazeeruddin, Md Khaja

    2010-10-14

    The recently reported heteroleptic cyclometallated iridium(III) complex [Ir(2-phenylpyridine)(2)(2-carboxy-4-dimethylaminopyridine)] N984 and its isomer N984b have been studied more in detail. While photo- and electrochemical properties are very similar, DFT/TDDFT calculations show that the two isomers have different HOMO orbital characteristics. As a consequence, solution processed OLEDs made using a mixture of N984 and isomer N984b similar to vacuum processed devices show that the isomer has a dramatic detrimental effect on the performances of the device. In addition, commonly used thermogravimetric analysis is not suitable for showing the isomerization process. The isomer could impact performances of vacuum processed OLEDs using heteroleptic cyclometallated iridium(III) complexes as dopant.

  1. Solution-Procesed Small-Molecule OLED Luminaire for Interior Illumination

    SciTech Connect

    Parker, Ian

    2012-02-29

    Prototype lighting panels and luminaires were fabricated using DuPont Displays solution-processed small-molecule OLED technology. These lighting panels were based on a spatially-patterned, 3-color design, similar in concept to an OLED display panel, with materials chosen to maximize device efficacy. The majority of the processing steps take place in air (rather than high vacuum). Optimization of device architecture, processing and construction was undertaken, with a final prototype design of 50 cm{sup 2} being fabricated and tested. Performance of these panels reached 35 lm/W at illuminant-A. A unique feature of this technology is the ability to color tune the emission, and color temperatures ranging from 2700 to > 6,500K were attained in the final build. Significant attention was paid to low-cost fabrication techniques.

  2. Inhibitory Effects of Isorhamnetin on the Invasion of Human Breast Carcinoma Cells by Downregulating the Expression and Activity of Matrix Metalloproteinase-2/9.

    PubMed

    Li, Chenglin; Yang, Dan; Zhao, Yuanwei; Qiu, Yu; Cao, Xin; Yu, Yanyan; Guo, Hao; Gu, Xiaoke; Yin, Xiaoxing

    2015-01-01

    Matrix metalloproteinases (MMPs) play an active role in facilitating the invasion of cancer cells with excessive extracellular matrix (ECM) degradation. In the present study, we investigated the antiinvasive effects of isorhamnetin, a naturally occurring flavonoid, on MDA-MB-231 human breast carcinoma cells. The results indicated that isorhamnetin significantly inhibited the adhesion, migration, and invasion of the cells in vitro. Moreover, isorhamnetin suppressed the activity and expression of MMP-2 and MMP-9, which were determined by gelatin zymography, real-time PCR, and Western blot analysis, respectively. Besides, isorhamnetin had little effect on the secretion of urokinase plasminogen activator. Further elucidation of the mechanism revealed that isorhamnetin exerted an inhibitory effect on the phosphorylation of p38 and STAT3, although it had no effect on ERK1/2 and JNK. Taken together, these data demonstrated that isorhamnetin could significantly inhibit the invasion of MDA-MB-231 cells by downregulating the expression and activity of MMP-2 and MMP-9, which was potentially associated with the suppression of p38 MAPK and STAT3. Therefore, the findings provide new evidence for the anti-cancer activity of isorhamnetin.

  3. Non-invasive dual fluorescence in vivo imaging for detection of macrophage infiltration and matrix metalloproteinase (MMP) activity in inflammatory arthritic joints.

    PubMed

    Cho, Hongsik; Bhatti, Fazal-Ur-Rehman; Yoon, Tae Won; Hasty, Karen A; Stuart, John M; Yi, Ae-Kyung

    2016-05-01

    Detection and intervention at an early stage is a critical factor to impede arthritis progress. Here we present a non-invasive method to detect inflammatory changes in joints of arthritic mice. Inflammation was monitored by dual fluorescence optical imaging for near-infrared fluorescent (750F) matrix-metalloproteinase activatable agent and allophycocyanin-conjugated anti-mouse CD11b. Increased intensity of allophycocyanin (indication of macrophage accumulation) and 750F (indication of matrix-metalloproteinase activity) showed a biological relationship with the arthritis severity score and the histopathology score of arthritic joints. Our results demonstrate that this method can be used to detect early stages of arthritis with minimum intervention in small animal models.

  4. Multi-layer printing of OLEDs as a tool for the creation of security features.

    PubMed

    Fischer, Bert; Kreissl, Stefanie; Boeffel, Christine; Wedel, Armin

    2012-03-12

    The combined deposition of structured and homogenous layers for the device setup of OLEDs results in a structured display visible with a gray scale impression. These permanently imprinted structures are only visible during the application of an electrical field and almost invisible in the off state. Most intriguing applications of such devices are security marks, electronic watermarks but also for advertising and design applications the creation of gray scale structures might have interesting applications.

  5. Roll-To-Roll Process for Transparent Metal Electrodes in OLED Manufacturing

    SciTech Connect

    Slafer, W. Dennis

    2010-06-02

    This program will develop and demonstrate a new manufacturing technology that can help to improve the efficiency and reduce the cost of producing the next generation solid-state lighting (OLEDs)for a broad range of commercial applications. This will not only improve US competitiveness in the manufacturing sector but will also result in a positive impact in meeting the Department of Energy’s goal of developing high efficiency lighting while reducing the environmental impact.

  6. Fabrication of a three-dimensional nanoporous polymer film as a diffuser for microcavity OLEDs

    NASA Astrophysics Data System (ADS)

    Pyo, Beom; Cho, Ye Ram; Suh, Min Chul

    2015-09-01

    We used a nanoporous polymer film prepared by cellulose acetate butyrate with ~40% of optical haze value as a diffuser. It was fabricated by a simple spin-coating process during continuous water mist supply by a humidifier. The pores were created by the elastic bouncing mechanism (rather than the thermocapillary convection mechanism) of the supplied water droplets. The shapes and sizes of the caves formed near the polymer surface are randomly distributed, with a relatively narrow pore size distribution (300-500 nm). Specifically, we focused on controlling the surface morphology to give a three-dimensional (3D) multi-stacked nanocave structure because we had already learnt that two-dimensional nanoporous structures showed serious loss of luminance in the forward direction. Using this approach, we found that the 3D nanoporous polymer film can effectively reduce the viewing angle dependency of strong microcavity OLEDs without any considerable decrease in the total intensity of the out-coupled light. We applied this nanoporous polymer film to microcavity OLEDs to investigate the possibility of using it as a diffuser layer. The resulting nanoporous polymer film effectively reduced the viewing angle dependency of the microcavity OLEDs, although a pixel blurring phenomenon occurred. Despite its negative effects, such as the drop in efficiency in the forward direction and the pixel blurring, the introduction of a nanoporous polymer film as a scattering medium on the back side of the glass substrate eliminated the viewing angle dependency. Thus, this approach is a promising method to overcome the serious drawbacks of microcavity OLEDs.

  7. Organic/Organic Heterointerface Engineering to Boost Carrier Injection in OLEDs

    NASA Astrophysics Data System (ADS)

    Fathollahi, Mohammadreza; Ameri, Mohsen; Mohajerani, Ezeddin; Mehrparvar, Ebrahim; Babaei, Mohammadrasoul

    2017-02-01

    We investigate dynamic formation of nanosheet charge accumulations by heterointerface engineering in double injection layer (DIL) based organic light emitting diodes (OLEDs). Our experimental results show that the device performance is considerably improved for the DIL device as the result of heterointerface injection layer (HIIL) formation, in comparison to reference devices, namely, the current density is doubled and even quadrupled and the turn-on voltage is favorably halved, to 3.7 V, which is promising for simple small-molecule OLEDs. The simulation reveals the (i) formation of dynamic p-type doping (DPD) region which treats the quasi Fermi level at the organic/electrode interface, and (ii) formation of dynamic dipole layer (DDL) and the associated electric field at the organic/organic interface which accelerates the ejection of the carriers and their transference to the successive layer. HIIL formation proposes alternate scenarios for device design. For instance, no prerequisite for plasma treatment of transparent anode electrode, our freedom in varying the thicknesses of the organic layers between 10 nm and 60 nm for the first layer and between 6 nm and 24 nm for the second layer. The implications of the present work give insight into the dynamic phenomena in OLEDs and facilitates the development of their inexpensive fabrication for lighting applications.

  8. Improvement of OLED properties with the AlN insulated layer

    NASA Astrophysics Data System (ADS)

    Liu, Chunling; Wang, Jin; Wang, Chunwu; Zhao, Lei; Jiang, Wenlong

    2010-11-01

    The thin aluminum nitride(AlN) film using as an insulating layer was inserted between the anode (ITO) and the NPB organic film in the organic light-emitting devices(OLED) for the structure being K9/ITO/AlN/NPB/Alq3/LiF/Al.The effect of the different thickness AlN film on the device performance was investigated. After optimization, improvement of OLEDs properties is biggest when the AlN film thickness is about 0.4nm.Such a structure with AlN layer facilitates the increase of current density and decrease of threshold voltage, resulting in an improved luminance and energy efficiency. The average luminance increased by about 30% and an improvement of 21.8% on the average current density. The lifetime experiment of the devices has proved an improvement on stability because of inserted AlN film. This phenomenon is mainly because of the insulating capability of the aluminum nitride coating and the passivation role of AlN film to the ITO surface. The processing is simple and high efficient, can be widely applied to the OLED devices.

  9. Organic/Organic Heterointerface Engineering to Boost Carrier Injection in OLEDs

    PubMed Central

    Fathollahi, Mohammadreza; Ameri, Mohsen; Mohajerani, Ezeddin; Mehrparvar, Ebrahim; Babaei, Mohammadrasoul

    2017-01-01

    We investigate dynamic formation of nanosheet charge accumulations by heterointerface engineering in double injection layer (DIL) based organic light emitting diodes (OLEDs). Our experimental results show that the device performance is considerably improved for the DIL device as the result of heterointerface injection layer (HIIL) formation, in comparison to reference devices, namely, the current density is doubled and even quadrupled and the turn-on voltage is favorably halved, to 3.7 V, which is promising for simple small-molecule OLEDs. The simulation reveals the (i) formation of dynamic p-type doping (DPD) region which treats the quasi Fermi level at the organic/electrode interface, and (ii) formation of dynamic dipole layer (DDL) and the associated electric field at the organic/organic interface which accelerates the ejection of the carriers and their transference to the successive layer. HIIL formation proposes alternate scenarios for device design. For instance, no prerequisite for plasma treatment of transparent anode electrode, our freedom in varying the thicknesses of the organic layers between 10 nm and 60 nm for the first layer and between 6 nm and 24 nm for the second layer. The implications of the present work give insight into the dynamic phenomena in OLEDs and facilitates the development of their inexpensive fabrication for lighting applications. PMID:28218246

  10. Candle light-style OLED: a plausibly human-friendly safe night light

    NASA Astrophysics Data System (ADS)

    Jou, Jwo-Huei; Chen, Po-Wei; Hsieh, Chun-Yu; Wang, Ching-Chiun; Chen, Chien-Chih; Tung, F.-C.; Chen, Szu-Hao; Wang, Yi-Shan

    2013-09-01

    Candles emit sensationally-warm light with a very-low color-temperature, comparatively most suitable for use at night. In response to the need for such a human-friendly night light, we demonstrate the employment of a high number of candle light complementary organic emitters to generate mimic candle light based on organic light emitting diode (OLED). One resultant candle light-style OLED shows a very-high color rendering index, with an efficacy at least 300 times that of candles or twice that of an incandescent bulb. The device can be fabricated, for example, by using four candle light complementary emitters, namely: red, yellow, green, and sky-blue phosphorescent dyes, vacuum-deposited into two emission layers, separated by a nano-layer of carrier modulation material to maximize both the desirable very-high color rendering index and energy efficiency, while keeping the blue emission very low and red emission high to obtain the desirable low color temperature. With different layer structures, the OLEDs can also show color tunable between that of candle light and dusk-hue. Importantly, a romantic sensation giving and supposedly physiologically-friendly candle light-style emission can hence be driven by electricity in lieu of the hydrocarbon-burning and greenhouse gas releasing candles that were invented 5,000 years ago.

  11. Multiview three-dimensional display with continuous motion parallax through planar aligned OLED microdisplays.

    PubMed

    Teng, Dongdong; Xiong, Yi; Liu, Lilin; Wang, Biao

    2015-03-09

    Existing multiview three-dimensional (3D) display technologies encounter discontinuous motion parallax problem, due to a limited number of stereo-images which are presented to corresponding sub-viewing zones (SVZs). This paper proposes a novel multiview 3D display system to obtain continuous motion parallax by using a group of planar aligned OLED microdisplays. Through blocking partial light-rays by baffles inserted between adjacent OLED microdisplays, transitional stereo-image assembled by two spatially complementary segments from adjacent stereo-images is presented to a complementary fusing zone (CFZ) which locates between two adjacent SVZs. For a moving observation point, the spatial ratio of the two complementary segments evolves gradually, resulting in continuously changing transitional stereo-images and thus overcoming the problem of discontinuous motion parallax. The proposed display system employs projection-type architecture, taking the merit of full display resolution, but at the same time having a thin optical structure, offering great potentials for portable or mobile 3D display applications. Experimentally, a prototype display system is demonstrated by 9 OLED microdisplays.

  12. Generation of 360° three-dimensional display using circular-aligned OLED microdisplays.

    PubMed

    Teng, Dongdong; Liu, Lilin; Wang, Biao

    2015-02-09

    A 360° all-around multiview three-dimensional (3D) display system is proposed by using coarse-pitch circular-aligned OLED microdisplays. The magnified virtual color images projected from microdisplays serve as stereo images, which can create separate eyeboxes for the viewer. Through inserting baffles, a transitional stereo image assembled by two spatially complementary segments from adjacent stereo images is presented to a complementary fusing zone (CFZ) which locates between adjacent eyeboxes. For a moving observation point, the spatial ratio of the two complementary segments evolves gradually, resulting in continuously changing transitional stereo images and thus overcoming the problem of discontinuous moving parallax. Such a controllable light-ray fusing technology, assured by the inherent large divergent angle of OLED pixels, decreases the required number of display panels for 360° multiview 3D display greatly. A prototype display system with only 67 full-color OLED microdisplays is set up to demonstrate the 360° 3D color display. The develop system is freed from the dependence on mechanical moving elements, high-speed components and diffusion screens.

  13. Phase Differential Enhancement of FLIM to Distinguish FRET Components of a Biosensor for Monitoring Molecular Activity of Membrane Type 1 Matrix Metalloproteinase in Live Cells

    PubMed Central

    Eichorst, John Paul; Huang, He

    2012-01-01

    Fluorescence lifetime-resolved imaging microscopy (FLIM) has been used to monitor the enzymatic activity of a proteolytic enzyme, Membrane Type 1 Matrix Metalloproteinase (MT1-MMP), with a recently developed FRET-based biosensor in vitro and in live HeLa and HT1080 cells. MT1-MMP is a collagenaise that is involved in the destruction of extra-cellular matrix (ECM) proteins, as well as in various cellular functions including migration. The increased expression of MT1-MMP has been positively correlated with the invasive potential of tumor cells. However, the precise spatiotemporal activation patterns of MT1-MMP in live cells are still not well-established. The activity of MT1-MMP was examined with our biosensor in live cells. Imaging of live cells was performed with full-field frequency-domain FLIM. Image analysis was carried out both with polar plots and phase differential enhancement. Phase differential enhancement, which is similar to phase suppression, is shown to facilitate the differentiation between different conformations of the MT1-MMP biosensor in live cells when the lifetime differences are small. FLIM carried out in differential enhancement or phase suppression modes, requires only two acquired phase images, and permits rapid imaging of the activity of MT1-MMP in live cells. PMID:21519891

  14. The relative roles of collagen adhesive receptor DDR2 activation and matrix stiffness on the downregulation of focal adhesion kinase in vascular smooth muscle cells.

    PubMed

    Bhadriraju, Kiran; Chung, Koo-Hyun; Spurlin, Tighe A; Haynes, Ross J; Elliott, John T; Plant, Anne L

    2009-12-01

    Cells within tissues derive mechanical anchorage and specific molecular signals from the insoluble extracellular matrix (ECM) that surrounds them. Understanding the role of different cues that extracellular matrices provide cells is critical for controlling and predicting cell response to scaffolding materials. Using an engineered extracellular matrix of Type I collagen we examined how the stiffness, supramolecular structure, and glycosylation of collagen matrices influence the protein levels of cellular FAK and the activation of myosin II. Our results show that (1) cellular FAK is downregulated on collagen fibrils, but not on a non-fibrillar monolayer of collagen, (2) the downregulation of FAK is independent of the stiffness of the collagen fibrils, and (3) FAK levels are correlated with levels of tyrosine phosphorylation of the collagen adhesion receptor DDR2. Further, siRNA depletion of DDR2 blocks FAK downregulation. Our results suggest that the collagen receptor DDR2 is involved in the regulation of FAK levels in vSMC adhered to Type I collagen matrices, and that regulation of FAK levels in these cells appears to be independent of matrix stiffness.

  15. Analysis and experimental verification of neutron-activated LiF as a stable matrix for tritium beta sources

    NASA Astrophysics Data System (ADS)

    Nullmeyer, Bradley R.; Kwon, Jae W.; Gahl, John M.; Dobey, Ronald J.; Gunn, Gregory; Flagg, Michael; Herbold, Carl

    2017-03-01

    Tritium (3H) has long been considered a useful radioisotope for many purposes due to its low-energy and pure beta decay. However, due to its aggressive migration, solid-state retention of tritium for use as a beta radiation source is challenging. Bulk-level infusion of tritium in a solid is often employed as a solution to effusion and outgassing but limits the beta radiation output due to the use of high-Z materials. This letter presents experimental and simulated analysis regarding the production and efficacy of a low-Z, solid-state tritium beta source. Single-crystal lithium fluoride (LiF) is used as a host matrix for tritium radionuclides, which are generated by the 6Li(n,α)3H reaction when the crystal is exposed to thermal neutron irradiation. The experimental findings present negligible outgassing of tritium from the material, while the simulation results suggest thickness optimization of the LiF/3H beta source. Moreover, the simulation results indicate significantly enhanced beta output efficiency compared to palladium tritide, which is a state-of-the-art tritium host. With proper thickness, the tritium-filled LiF matrix is a stable low energy beta source, which can be easily produced and incorporated into a variety of applications.

  16. High glucose enhances microRNA-26a to activate mTORC1 for mesangial cell hypertrophy and matrix protein expression

    PubMed Central

    Dey, Nirmalya; Bera, Amit; Das, Falguni; Ghosh-Choudhury, Nandini; Kasinath, Balakuntalam S.; Choudhury, Goutam Ghosh

    2015-01-01

    High glucose milieu inhibits PTEN expression to activate Akt kinase and induces glomerular mesangial cell hypertrophy and matrix protein expression in diabetic nephropathy. Specific mechanism by which high glucose inhibits PTEN expression is not clear. We found that high glucose increased the expression of the microRNA-26a (miR-26a) in mesangial cells. Using a sensor plasmid with 3’UTR-driven luciferase, we showed PTEN as a target of miR-26a in response to high glucose. Overexpression of miR-26a reduced the PTEN protein levels resulting in increased Akt kinase activity similar to high glucose treatment. In contrast, anti-miR-26a reversed high glucose-induced suppression of PTEN with concomitant inhibition of Akt kinase activity. Akt-mediated phosphorylation of tuberin and PRAS40 regulates mTORC1, which is necessary for mesangial cell hypertrophy and matrix protein expression. Inhibition of high glucose-induced miR-26a blocked phosphorylation of tuberin and PRAS40, which lead to suppression of phosphorylation of S6 kinase and 4EBP-1, two substrates of mTORC1. Furthermore, we show that expression of miR-26a induced mesangial cell hypertrophy and increased fibronectin and collagen I (α2) expression similar to that observed with the cells incubated with high glucose. Anti-miR-26a inhibited these phenomena in response to high glucose. Together our results provide the first evidence for the involvement of miR-26a in high glucose-induced mesangial cell hypertrophy and matrix protein expression. These data indicate the potential therapeutic utility of anti-miR-26a for the complications of diabetic kidney disease. PMID:25797045

  17. The significance of matrix effects on the measurement of lactate dehydrogenase (LD) activity using Kodak dry slide technology in the Ontario Laboratory Proficiency Testing Program.

    PubMed

    Hill, S A; Heathcote, J C; McQueen, M J

    1990-04-01

    A recent lactate dehydrogenase (LD) survey of the Laboratory Proficiency Testing Program (LPTP) of Ontario showed interlaboratory coefficients of variation ranging from 6.5% to 40% for five lyophilized vials on the 12 Kodak analyzers. All the LPTP survey samples had similar protein and LD isoenzyme electrophoretic patterns which remained unchanged after reconstitution and storage for 5 days at 4 degrees C, although the total LD activities fell. Four Ektachem 700 analyzers were subsequently tested using LPTP material and no difference in LD activity between instruments or between two LD slide lot numbers was shown. Generation 9 slides gave higher LD activities than generation 10 on all the reconstituted lyophilized proficiency testing samples. There was no significant difference between slide generations when 19 liquid human sera were analyzed, indicating that the variability on LPTP samples was due to a matrix effect. Definition of the matrix effect of lyophilized proficiency testing material is essential before any proficiency testing program can use such material to reflect analytical performance on patient specimens.

  18. Co-Culture of Tumor Spheroids and Fibroblasts in a Collagen Matrix-Incorporated Microfluidic Chip Mimics Reciprocal Activation in Solid Tumor Microenvironment

    PubMed Central

    Jeong, Su-Yeong; Lee, Ji-Hyun; Shin, Yoojin; Chung, Seok; Kuh, Hyo-Jeong

    2016-01-01

    Multicellular 3D culture and interaction with stromal components are considered essential elements in establishing a ‘more clinically relevant’ tumor model. Matrix-embedded 3D cultures using a microfluidic chip platform can recapitulate the microscale interaction within tumor microenvironments. As a major component of tumor microenvironment, cancer-associated fibroblasts (CAFs) play a role in cancer progression and drug resistance. Here, we present a microfluidic chip-based tumor tissue culture model that integrates 3D tumor spheroids (TSs) with CAF in proximity within a hydrogel scaffold. HT-29 human colorectal carcinoma cells grew into 3D TSs and the growth was stimulated when co-cultured with fibroblasts as shown by 1.5-folds increase of % changes in diameter over 5 days. TS cultured for 6 days showed a reduced expression of Ki-67 along with increased expression of fibronectin when co-cultured with fibroblasts compared to mono-cultured TSs. Fibroblasts were activated under co-culture conditions, as demonstrated by increases in α-SMA expression and migratory activity. When exposed to paclitaxel, a survival advantage was observed in TSs co-cultured with activated fibroblasts. Overall, we demonstrated the reciprocal interaction between TSs and fibroblasts in our 7-channel microfluidic chip. The co-culture of 3D TS-CAF in a collagen matrix-incorporated microfluidic chip may be useful to study the tumor microenvironment and for evaluation of drug screening and evaluation. PMID:27391808

  19. Degradation of fibrin and elastin by intact human alveolar macrophages in vitro. Characterization of a plasminogen activator and its role in matrix degradation.

    PubMed Central

    Chapman, H A; Stone, O L; Vavrin, Z

    1984-01-01

    Fibrin deposition is prominent in the histopathology of a number of inflammatory lung diseases. Plasmin, activated locally in the lung, can degrade not only this fibrin but potentially structural proteins important to normal lung architecture. Because alveolar macrophages are prominent in inflammatory processes of the lung, we examined the plasminogen activator (PA) activity of human alveolar macrophages. Intact alveolar macrophages from each of 10 healthy subjects expressed PA activity. There was no difference in activity between smoking and nonsmoking individuals. The activator activity was largely cell-associated, but under certain culture conditions, macrophages released a soluble activator into the culture medium. The membrane-bound activator had an apparent molecular mass of 52-55 kD in nonreduced sodium dodecyl sulfate (SDS) gels, and monospecific antibody to urokinase neutralized the enzyme activity. Immunoprecipitation of [35S]methionine-labeled cells showed that human alveolar macrophages actually synthesize the PA in vitro. SDS-gel analysis of the immunoprecipitated material revealed the predominant species of PA to be structurally similar to reduced, active urokinase. We also examined the role of PA in the degradation of both insoluble fibrin and elastin matrices by live macrophages. Cells degraded an insoluble fibrin matrix in the presence of plasminogen whether or not the macrophages contacted the fibrin as long as proteinase inhibitors were not in the culture medium. In the presence of serum proteinase inhibitors, macrophages still degraded a fibrin matrix, but only if they were in contact with the fibrin. Live macrophages also degraded insoluble elastin only when in contact with the elastin but could do so even in the presence of serum proteinase inhibitors. In matrices containing a mixture of fibrin and elastin, cells did not degrade elastin unless plasminogen was added to the medium. These results indicate that normal alveolar macrophages

  20. A new nano-optical sensor thin film cadmium sulfide doped in sol-gel matrix for assessment of α-amylase activity in human saliva.

    PubMed

    Attia, M S; Zoulghena, H; Abdel-Mottaleb, M S A

    2014-02-21

    A novel, simple, sensitive and precise spectrofluorimetric method is developed for measuring the activity of the α-amylase enzyme in human saliva. The remarkable quenching of the luminescence intensity at 634 nm of nano CdS doped in a sol-gel matrix by various concentrations of maltose (produced from the reaction of the enzyme with the starch substrate) was successfully used as an optical sensor for the assessment of α-amylase activity. The calibration plot was achieved over the concentration range 4.8 × 10(-10) to 1.2 × 10(-5) mol L(-1) maltose with a correlation coefficient of 0.999 and a detection limit of 5.7 × 10(-11) mol L(-1). The method was used satisfactorily for assessment of the α-amylase activity in a number of human saliva samples collected from various healthy volunteers.

  1. Anti-elastase, anti-tyrosinase and matrix metalloproteinase-1 inhibitory activity of earthworm extracts as potential new anti-aging agent

    PubMed Central

    Azmi, Nurhazirah; Hashim, Puziah; Hashim, Dzulkifly M; Halimoon, Normala; Majid, Nik Muhamad Nik

    2014-01-01

    Objective To examine whether earthworms of Eisenia fetida, Lumbricus rubellus and Eudrilus eugeniae extracts have elastase, tyrosinase and matrix metalloproteinase-1 (MMP-1) inhibitory activity. Methods The earthworms extract was screened for elastase, tyrosinase and MMP-1 inhibitory activity and compared with the positive controls. It was also evaluated for whitening and anti-wrinkle capacity. Results The extract showed significantly (P<0.05) good elastase and tyrosinase inhibition and excellent MMP-1 inhibition compared to N-Isobutyl-N-(4-methoxyphenylsulfonyl)-glycylhydroxamic acid. Conclusions Earthworms extract showed effective inhibition of tyrosinase, elastase and MMP-1 activities. Therefore, this experiment further rationalizes the traditional use of this worm extracts which may be useful as an anti-wrinkle agent. PMID:25183109

  2. Extracellular matrix metalloproteinase inducer (CD147) is a novel receptor on platelets, activates platelets, and augments nuclear factor kappaB-dependent inflammation in monocytes.

    PubMed

    Schmidt, Roland; Bültmann, Andreas; Fischel, Sina; Gillitzer, Angelika; Cullen, Paul; Walch, Axel; Jost, Philipp; Ungerer, Martin; Tolley, Neal D; Lindemann, Stephan; Gawaz, Meinrad; Schömig, Albert; May, Andreas E

    2008-02-15

    In atherosclerosis, circulating platelets interact with endothelial cells and monocytes, leading to cell activation and enhanced recruitment of leukocytes into the vascular wall. The invasion of monocytes is accompanied by overexpression of matrix metalloproteinases (MMPs), which are thought to promote atherosclerosis and trigger plaque rupture. Following interaction with itself, the extracellular matrix metalloproteinase inducer (EMMPRIN) induces MMP synthesis via a little-known intracellular pathway. Recently, we showed upregulation of EMMPRIN on monocytes during acute myocardial infarction. EMMPRIN also stimulates secretion of MMP-9 by monocytes and of MMP-2 by smooth muscle cells, indicating that it may be an important regulator of MMP activity. Expression of EMMPRIN on platelets has not been described until now. Here, we demonstrate that resting platelets show low surface expression of EMMPRIN, which is upregulated by various platelet stimulators (flow cytometry). EMMPRIN is located in the open canalicular system and in alpha granules of platelets (according to electron microscopy and sucrose gradient ultracentrifugation). Platelet stimulation with recombinant EMMPRIN-Fc induced surface expression of CD40L and P-selectin (according to flow cytometry), suggesting that EMMPRIN-EMMPRIN interaction activates platelets. Coincubation of platelets with monocytes induced EMMPRIN-mediated nuclear factor kappaB activation (according to Western blot) in monocytes with increased MMP-9 (zymography), interleukin-6, and tumor necrosis factor-alpha secretion (according to ELISA) by monocytes. In conclusion, EMMPRIN displays a new platelet receptor that is upregulated on activated platelets. Binding of EMMPRIN to platelets fosters platelet degranulation. Platelet-monocyte interactions via EMMPRIN stimulate nuclear factor kappaB-driven inflammatory pathways in monocytes, such as MMP and cytokine induction. Thus, EMMPRIN may represent a novel target to diminish the burden of

  3. Matrix Metalloproteinase-3 (MMP-3) Is an Endogenous Activator of the MMP-9 Secreted by Placental Leukocytes: Implication in Human Labor

    PubMed Central

    Flores-Pliego, Arturo; Espejel-Nuñez, Aurora; Castillo-Castrejon, Marisol; Meraz-Cruz, Noemi; Beltran-Montoya, Jorge; Zaga-Clavellina, Veronica; Nava-Salazar, Sonia; Sanchez-Martinez, Maribel; Vadillo-Ortega, Felipe; Estrada-Gutierrez, Guadalupe

    2015-01-01

    Background The activity of matrix degrading enzymes plays a leading role in the rupture of the fetal membranes under normal and pathological human labor, and matrix metalloproteinase-9 (MMP-9) it is considered a biomarker of this event. To gain further insight into local MMP-9 origin and activation, in this study we analyzed the contribution of human placental leukocytes to MMP-9 secretion and explored the local mechanisms of the pro-enzyme activation. Methods Placental blood leukocytes were obtained from women at term gestation without labor and maintained in culture up to 72 h. MMP-9 activity in the culture supernatants was determined by zymography and using a specific substrate. The presence of a potential pro-MMP-9 activator in the culture supernatants was monitored using a recombinant biotin-labeled human pro-MMP-9. To characterize the endogenous pro-MMP-9 activator, MMP-1, -3, -7 and -9 were measured by multiplex assay in the supernatants, and an inhibition assay of MMP-9 activation was performed using an anti-human MMP-3 and a specific MMP-3 inhibitor. Finally, production of MMP-9 and MMP-3 in placental leukocytes obtained from term pregnancies with and without labor was assessed by immunofluorescence. Results Placental leukocytes spontaneously secreted pro-MMP-9 after 24 h of culture, increasing significantly at 48 h (P≤0.05), when the active form of MMP-9 was detected. Culture supernatants activated the recombinant pro-MMP-9 showing that placental leukocytes secrete the activator. A significant increase in MMP-3 secretion by placental leukocytes was observed since 48 h in culture (P≤0.05) and up to 72 h (P≤0.001), when concentration reached its maximum value. Specific activity of MMP-9 decreased significantly (P≤0.005) when an anti-MMP-3 antibody or a specific MMP-3 inhibitor were added to the culture media. Placental leukocytes from term labor produced more MMP-9 and MMP-3 compared to term non-labor cells. Conclusions In this work we confirm that

  4. An inhibitor of thrombin activated fibrinolysis inhibitor (TAFI) can reduce extracellular matrix accumulation in an in vitro model of glucose induced ECM expansion.

    PubMed

    Atkinson, J M; Pullen, N; Johnson, T S

    2013-06-24

    Chronic kidney disease (CKD) is characterised by the pathological accumulation of extracellular matrix (ECM) proteins leading to progressive kidney scarring via glomerular and tubular basement membrane expansion. Increased ECM synthesis and deposition, coupled with reduced ECM breakdown contribute to the elevated ECM level in CKD. Previous pre-clinical studies have demonstrated that increased plasmin activity has a beneficial effect in the protein overload model of CKD. As plasmin activation is downregulated by the action of the thrombin activated fibrinolytic inhibitor (TAFI), we tested the hypothesis that inhibition of TAFI might increase plasmin activity and reduce ECM accumulation in an in vitro model of glucose induced ECM expansion. Treatment of NRK52E tubular epithelial cells with increasing concentrations of glucose resulted in a 40% increase in TAFI activity, a 38% reduction in plasmin activity and a subsequent increase in ECM accumulation. In this model system, application of the previously reported TAFI inhibitor UK-396082 [(2S)-5-amino-2-[(1-n-propyl-1H-imidazol-4-yl)methyl]pentanoic acid] caused a reduction in TAFI activity, increased plasmin activity and induced a parallel decrease in ECM levels. In contrast, RNAi knockdown of plasmin resulted in an increase in ECM levels. The data presented here indicate that high glucose induces TAFI activity, inhibiting plasmin activation which results in elevated ECM levels in tubular epithelial cells. The results support the hypothesis that UK-396082 is able to reduce TAFI activity, normalising plasmin activity and preventing excess ECM accumulation suggesting that TAFI inhibition may have potential as an anti-scarring strategy in CKD.

  5. The HIV Matrix Protein p17 Promotes the Activation of Human Hepatic Stellate Cells through Interactions with CXCR2 and Syndecan-2

    PubMed Central

    Renga, Barbara; Francisci, Daniela; Schiaroli, Elisabetta; Carino, Adriana; Cipriani, Sabrina; D'Amore, Claudio; Sidoni, Angelo; Sordo, Rachele Del; Ferri, Ivana; Lucattelli, Monica; Lunghi, Benedetta; Baldelli, Franco; Fiorucci, Stefano

    2014-01-01

    Background The human immunodeficiency virus type 1 (HIV-1) p17 is a matrix protein involved in virus life's cycle. CXCR2 and Syndecan-2, the two major coreceptors for the p17 protein, are expressed in hepatic stellate cells (HSCs), a key cell type involved in matrix deposition in liver fibrotic disorders. Aim In this report we have investigated the in vitro impact of p17 on HSCs transdifferentiation and function and underlying signaling pathways involved in these processes. Methods LX-2 cells, a human HSC line, and primary HSC were challenged with p17 and expressions of fibrogenic markers and of p17 receptors were assessed by qRT-PCR and Western blot. Downstream intracellular signaling pathways were evaluated with qRT-PCR and Western blot as well as after pre-treatment with specific pathway inhibitors. Results Exposure of LX2 cells to p17 increases their contractile force, reshapes the cytoskeleton fibers and upregulates the expression of transdifferentiation markers including αSMA, COL1α1 and endothelin-1 through the activation of Jak/STAT and Rho signaling pathways. These effects are lost in HSCs pre-incubated with a serum from HIV positive person who underwent a vaccination with a p17 peptide. Confocal laser microscopy studies demonstrates that CXCR2 and syndecan-2 co-associate at the plasma membrane after exposure to p17. Immunostaining of HIV/HCV liver biopsies from co-infected patients reveals that the progression of liver fibrosis correlates with a reduced expression of CXCR2. Conclusions The HIV matrix protein p17 is pro-fibrogenic through its interactions both with CXCR2 and syndecan-2 on activated HSCs. PMID:24736615

  6. In-situ growth of antimony sulfide in carbon nanoparticle matrix: Enhanced electrocatalytic activity as counter electrode in dye-sensitized solar cells

    NASA Astrophysics Data System (ADS)

    Sun, Panpan; Zhang, Ming; Ai, Changzhi; Wu, Zhixin; Lu, Shuang; Zhang, Xintong; Huang, Niu; Sun, Yihua; Sun, Xiaohua

    2016-07-01

    Considering the undesirable electrocatalytic activity toward I-/I3- redox system of prinstine antimony sulfide (Sb2S3) fabricated with the existing conditions, a mesoporous carbon nanoparticle film (CNP) is introduced here for in-situ growth of Sb2S3 to construct a Sb2S3@CNP hybrid catalyst. Based on a Sb-thiourea precursor solution, in-situ growth of Sb2S3 can be achieved via solution deposition (denoted as Sb2S3@CNP-S) as well as atmospheric pressure thermal evaporation (denoted as Sb2S3@CNP-T) in CNP matrix. Structural characterizations indicate that Sb2S3 particles have well dispersed in the pores of CNP matrix. Because of the introduction of porous and conductive CNP matrix to support Sb2S3, the hybrid catalyst exhibits lower charge transfer resistance at the catalyst/electrolyte interface and higher electrocatalytic activity. When used as counter electrode (CE) for dye-sensitized solar cells (DSSCs), devices using Sb2S3@CNP hybrid catalyst as CE produce fill factor of 67.6% and 66.3%, which is significantly higher than that using pristine Sb2S3 fabricated in our previous work (52.8%). Finally, the corresponding power conversion efficiencies reach 6.69% (Sb2S3@CNP-S) and 6.24% (Sb2S3@CNP-T), respectively, which are comparable to that using Pt CE measured under the same conditions (6.74%).

  7. C-Cl activation by group IV metal oxides in solid argon matrixes: matrix isolation infrared spectroscopy and theoretical investigations of the reactions of MOx (M = Ti, Zr; x = 1, 2) with CH3Cl.

    PubMed

    Zhao, Yanying

    2013-07-11

    Reactions of the ground-state titanium and zirconium monoxide and dioxide molecules with monochloromethane in excess argon matrixes have been investigated in solid argon by infrared absorption spectroscopy and density functional theoretical calculations. The results show that the ground-state MOx (M = Ti, Zr; x = 1, 2) molecules react with CH3Cl to first form the weakly bound MO(CH3Cl) and MO2(CH3Cl) complexes. The MO(CH3Cl) complexes can rearrange to the CH3M(O)Cl isomers with the Cl atom of CH3Cl coordination to the metal center of MO upon UV light irradiation (λ < 300 nm). Theoretical calculations indicate that the electronic state crossings exist from the MO + CH3Cl reaction to the more stable CH3M(O)Cl molecules via the MO(CH3Cl) complexes traversing their corresponding transition states. The MO2(CH3Cl) complexes can isomerize to the more stable CH3OM(O)Cl molecules with the addition of the C-Cl bond of CH3Cl to one of the O═M bonds of MO2 upon annealing after broad-band light irradiation. The C-Cl activation by the MOx mechanism was interpreted by the calculated potential energy profiles.

  8. Inhibitory effect of berberine on the invasion of human lung cancer cells via decreased productions of urokinase-plasminogen activator and matrix metalloproteinase-2

    SciTech Connect

    Peng, P.-L.; Hsieh, Y.-S.; Wang, C.-J.; Hsu, J.-L.; Chou, F.-P. . E-mail: fpchou@csmu.edu.tw

    2006-07-01

    Berberine, a compound isolated from medicinal herbs, has been reported with many pharmacological effects related to anti-cancer and anti-inflammation capabilities. In this study, we observed that berberine exerted a dose- and time-dependent inhibitory effect on the motility and invasion ability of a highly metastatic A549 cells under non-cytotoxic concentrations. In cancer cell migration and invasion process, matrix-degrading proteinases are required. A549 cell treated with berberine at various concentrations showed reduced ECM proteinases including matrix metalloproteinase-2 (MMP2) and urokinase-plasminogen activator (u-PA) by gelatin and casein zymography analysis. The inhibitory effect is likely to be at the transcriptional level, since the reduction in the transcripts levels was corresponding to the proteins. Moreover, berberine also exerted its action via regulating tissue inhibitor of metalloproteinase-2 (TIMP-2) and urokinase-plasminogen activator inhibitor (PAI). The upstream mediators of the effect involved c-jun, c-fos and NF-{kappa}B, as evidenced by reduced phosphorylation of the proteins. These findings suggest that berberine possesses an anti-metastatic effect in non-small lung cancer cell and may, therefore, be helpful in clinical treatment.

  9. 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.

  10. 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.

  11. A nuclear matrix attachment site in the 4q35 locus has an enhancer-blocking activity in vivo: implications for the facio-scapulo-humeral dystrophy.

    PubMed

    Petrov, Andrei; Allinne, Jeanne; Pirozhkova, Iryna; Laoudj, Dalila; Lipinski, Marc; Vassetzky, Yegor S

    2008-01-01

    Facio-scapulo-humeral dystrophy (FSHD), a muscular hereditary disease with a prevalence of 1 in 20,000, is caused by a partial deletion of a subtelomeric repeat array on chromosome 4q. Earlier, we demonstrated the existence in the vicinity of the D4Z4 repeat of a nuclear matrix attachment site, FR-MAR, efficient in normal human myoblasts and nonmuscular human cells but much weaker in muscle cells from FSHD patients. We now report that the D4Z4 repeat contains an exceptionally strong transcriptional enhancer at its 5'-end. This enhancer up-regulates transcription from the promoter of the neighboring FRG1 gene. However, an enhancer blocking activity was found present in FR-MAR that in vitro could protect transcription from the enhancer activity of the D4Z4 array. In vivo, transcription from the FRG1 and FRG2 genes could be down- or up-regulated depending on whether or not FR-MAR is associated with the nuclear matrix. We propose a model for an etiological role of the delocalization of FR-MAR in the genesis of FSHD.

  12. Interleukin-1β activates focal adhesion kinase and Src to induce matrix metalloproteinase-9 production and invasion of MCF-7 breast cancer cells

    PubMed Central

    Mon, Naing Naing; Senga, Takeshi; Ito, Satoko

    2017-01-01

    Interleukin-1β (IL-1b) is a pleiotropic cytokine that is important in tumor progression and invasion. Matrix metalloproteinase-9 (MMP-9), which is a secreted matrix-degrading enzyme, is one of the key regulators of tumor invasion and metastasis. The current report indicated that IL-1b promotes MMP-9 production and cell invasion in non-metastatic MCF-7 breast cancer cells. IL-1b activated focal adhesion kinase (FAK) and proto-oncogene tyrosine-protein kinase Src (Src). Moreover, inhibiting the Src/FAK pathway reduced the IL-1b-induced production of MMP-9 and cell invasion. To investigate the functional role of FAK in MMP-9 production cell lines expressing mutant FAK in FAK knock-out mouse fibroblasts were generated. In wild-type FAK-expressing cells, MMP-9 production was induced by IL-1b stimulation. By contrast, IL-1b-induced MMP-9 production was abrogated in FAK knock-out, FAK Y397F, FAK Y925F, and kinase dead mutant-expressing cells. Therefore the results of the current study indicate that FAK and Src kinases are activated by IL-1b and play a critical role in MMP-9 production and tumor cell invasion. PMID:28356984

  13. High efficient OLED displays prepared with the air-gapped bridges on quantum dot patterns for optical recycling.

    PubMed

    Kim, Hyo-Jun; Shin, Min-Ho; Kim, Joo-Suc; Kim, Se-Eun; Kim, Young-Joo

    2017-02-17

    An optically efficient structure was proposed and fabricated to realize high brightness organic light emitting diode (OLED) displays based on a white OLED prepared with the air-gapped bridges on the quantum dot (QD) patterns. Compared with a conventional white OLED display, in our experiments, the optical intensity of the proposed OLED display shows the enhancement of 58.2% in the red color and 16.8% in the green color after applying the air-gapped bridge structure on QD patterns of 20 wt% concentration. This enhancement comes from the two facts that the QD patterns downconvert unnecessary blue or blue/green light to the required green or red light and the air-gapped bridges increase the color conversion efficiency of QDs by optical recycling using total internal reflection (TIR) at the interface. In addition, the color gamut of the proposed OLED display increases from 65.5 to 75.9% (NTSC x, y ratio) due to the narrow emission spectra of QDs.

  14. High efficient OLED displays prepared with the air-gapped bridges on quantum dot patterns for optical recycling

    PubMed Central

    Kim, Hyo-Jun; Shin, Min-Ho; Kim, Joo-Suc; Kim, Se-Eun; Kim, Young-Joo

    2017-01-01

    An optically efficient structure was proposed and fabricated to realize high brightness organic light emitting diode (OLED) displays based on a white OLED prepared with the air-gapped bridges on the quantum dot (QD) patterns. Compared with a conventional white OLED display, in our experiments, the optical intensity of the proposed OLED display shows the enhancement of 58.2% in the red color and 16.8% in the green color after applying the air-gapped bridge structure on QD patterns of 20 wt% concentration. This enhancement comes from the two facts that the QD patterns downconvert unnecessary blue or blue/green light to the required green or red light and the air-gapped bridges increase the color conversion efficiency of QDs by optical recycling using total internal reflection (TIR) at the interface. In addition, the color gamut of the proposed OLED display increases from 65.5 to 75.9% (NTSC x, y ratio) due to the narrow emission spectra of QDs. PMID:28211516

  15. High efficient OLED displays prepared with the air-gapped bridges on quantum dot patterns for optical recycling

    NASA Astrophysics Data System (ADS)

    Kim, Hyo-Jun; Shin, Min-Ho; Kim, Joo-Suc; Kim, Se-Eun; Kim, Young-Joo

    2017-02-01

    An optically efficient structure was proposed and fabricated to realize high brightness organic light emitting diode (OLED) displays based on a white OLED prepared with the air-gapped bridges on the quantum dot (QD) patterns. Compared with a conventional white OLED display, in our experiments, the optical intensity of the proposed OLED display shows the enhancement of 58.2% in the red color and 16.8% in the green color after applying the air-gapped bridge structure on QD patterns of 20 wt% concentration. This enhancement comes from the two facts that the QD patterns downconvert unnecessary blue or blue/green light to the required green or red light and the air-gapped bridges increase the color conversion efficiency of QDs by optical recycling using total internal reflection (TIR) at the interface. In addition, the color gamut of the proposed OLED display increases from 65.5 to 75.9% (NTSC x, y ratio) due to the narrow emission spectra of QDs.

  16. Device reflectivity as a simple rule for predicting the suitability of scattering foils for improved OLED light extraction

    NASA Astrophysics Data System (ADS)

    Levell, Jack W.; Harkema, Stephan; Pendyala, Raghu K.; Rensing, Peter A.; Senes, Alessia; Bollen, Dirk; MacKerron, Duncan; Wilson, Joanne S.

    2013-09-01

    A general challenge in Organic Light Emitting Diodes (OLEDs) is to extract the light efficiently from waveguided modes within the device structure. This can be accomplished by applying an additional scattering layer to the substrate which results in outcoupling increases between 0% to <100% in external quantum efficiency. In this work, we aim to address this large variation and show that the reflectivity of the OLED is a simple and useful predictor of the efficiency of substrate scattering techniques without the need for detailed modeling. We show that by optimizing the cathode and anode structure of glass based OLEDs by using silver and an ITO free high conductive Agfa Orgacon™ PEDOT:PSS we are able to increase the external quantum efficiency of OLEDs with the same outcoupling substrates from 2.4% to 5.6%, an increase of 130%. In addition, Holst Centre and partners are developing flexible substrates with integrated light extraction features and roll to roll compatible processing techniques to enable this next step in OLED development both for lighting and display applications. These devices show promise as they are shatterproof substrates and facilitate low cost manufacture.

  17. Influence of bilayer resist processing on p-i-n OLEDs: towards multicolor photolithographic structuring of organic displays

    NASA Astrophysics Data System (ADS)

    Krotkus, Simonas; Nehm, Frederik; Janneck, Robby; Kalkura, Shrujan; Zakhidov, Alex A.; Schober, Matthias; Hild, Olaf R.; Kasemann, Daniel; Hofmann, Simone; Leo, Karl; Reineke, Sebastian

    2015-03-01

    Recently, bilayer resist processing combined with development in hydrofluoroether (HFE) solvents has been shown to enable single color structuring of vacuum-deposited state-of-the-art organic light-emitting diodes (OLED). In this work, we focus on further steps required to achieve multicolor structuring of p-i-n OLEDs using a bilayer resist approach. We show that the green phosphorescent OLED stack is undamaged after lift-off in HFEs, which is a necessary step in order to achieve RGB pixel array structured by means of photolithography. Furthermore, we investigate the influence of both, double resist processing on red OLEDs and exposure of the devices to ambient conditions, on the basis of the electrical, optical and lifetime parameters of the devices. Additionally, water vapor transmission rates of single and bilayer system are evaluated with thin Ca film conductance test. We conclude that diffusion of propylene glycol methyl ether acetate (PGMEA) through the fluoropolymer film is the main mechanism behind OLED degradation observed after bilayer processing.

  18. The use of a diode matrix in commissioning activities for electron energies > or = 9 MeV: a feasibility study.

    PubMed

    Borca, Valeria Casanova; Pasquino, Massimo; Ozzello, Franca; Tofani, Santi

    2009-04-01

    The contribution of a commercially available diode matrix (MapCHECK, provided by Sun Nuclear, Melbourne, FL) for the commissioning procedures of the voxel based Monte Carlo (VMC++) algorithm for electron beams of MasterPlan treatment planning system was investigated. The attention is mainly focused on the calculation in homogeneous and heterogeneous phantoms. With this aim, following a data set similar to that proposed by Electron Collaborative Working Group (ECWG), the dose profiles and two-dimensional (2D) dose distributions measured by the diode matrix were compared with the calculated ones using the gamma analysis method with acceptance criteria for the dose difference and the distance to agreement equal to 4% and 4 mm, respectively. The average and standard deviation of the percentage of points satisfying the constraint gamma < or = 1 are 98.3 +/- 4.1% and 99.3 +/- 1.7% for the 9 and 12 MeV electron beam, respectively, showing that the accuracy of MasterPlan electron beam algorithm is good for simple two-dimensional geometries as well as for more complicated three-dimensional ones. The results are in agreement with those reported in literature by Cygler et al. ["Evaluation of the first commercial Monte Carlo dose calculation engine for electron beam treatment planning," Med. Phys. 31, 142-153 (2004)]. In addition, the authors have also analyzed the response of the 2D array in terms of dose profiles at different depths, comparing the results with those obtained in water phantom using an electron diode. The results show that in the low gradient regions there were no deviations larger than the criteria of acceptability set by Van Dyk et al. ["Commissioning and quality assurance of treatment planning computers," Int. J. Radiat. Oncol. Biol. Phys. 26, 261-273 (1993)]; in the high gradient region, the maximum deviations are less than 2 mm with most of the values less than 1 mm. The present article shows that MapCHECK can play a useful role in the commissioning of

  19. The use of a diode matrix in commissioning activities for electron energies {>=}9 MeV: A feasibility study

    SciTech Connect

    Casanova Borca, Valeria; Pasquino, Massimo; Ozzello, Franca; Tofani, Santi

    2009-04-15

    The contribution of a commercially available diode matrix (MapCHECK trade mark sign , provided by Sun Nuclear, Melbourne, FL) for the commissioning procedures of the voxel based Monte Carlo (VMC++) algorithm for electron beams of MasterPlan treatment planning system was investigated. The attention is mainly focused on the calculation in homogeneous and heterogeneous phantoms. With this aim, following a data set similar to that proposed by Electron Collaborative Working Group (ECWG), the dose profiles and two-dimensional (2D) dose distributions measured by the diode matrix were compared with the calculated ones using the gamma analysis method with acceptance criteria for the dose difference and the distance to agreement equal to 4% and 4 mm, respectively. The average and standard deviation of the percentage of points satisfying the constraint {gamma}{<=}1 are 98.3{+-}4.1% and 99.3{+-}1.7% for the 9 and 12 MeV electron beam, respectively, showing that the accuracy of MasterPlan electron beam algorithm is good for simple two-dimensional geometries as well as for more complicated three-dimensional ones. The results are in agreement with those reported in literature by Cygler et al. [''Evaluation of the first commercial Monte Carlo dose calculation engine for electron beam treatment planning,'' Med. Phys. 31, 142-153 (2004)]. In addition, the authors have also analyzed the response of the 2D array in terms of dose profiles at different depths, comparing the results with those obtained in water phantom using an electron diode. The results show that in the low gradient regions there were no deviations larger than the criteria of acceptability set by Van Dyk et al. [''Commissioning and quality assurance of treatment planning computers,'' Int. J. Radiat. Oncol. Biol. Phys. 26, 261-273 (1993)]; in the high gradient region, the maximum deviations are less than 2 mm with most of the values less than 1 mm. The present article shows that MapCHECK trade mark sign can play a

  20. Novel Low Cost Organic Vapor Jet Printing of Striped High Efficiency Phosphorescent OLEDs for White Lighting

    SciTech Connect

    Mike Hack

    2008-12-31

    In this program, Universal Display Corporation and University of Michigan proposed to integrate three innovative concepts to meet the DOE's Solid State Lighting (SSL) goals: (1) high-efficiency phosphorescent organic light emitting device (PHOLED{trademark}) technology, (2) a white lighting design that is based on a series of red, green and blue OLED stripes, and (3) the use of a novel cost-effective, high rate, mask-less deposition process called organic vapor jet printing (OVJP). Our PHOLED technology offers up to four-times higher power efficiency than other OLED approaches for general lighting. We believe that one of the most promising approaches to maximizing the efficiency of OLED lighting sources is to produce stripes of the three primary colors at such a pitch (200-500 {mu}m) that they appear as a uniform white light to an observer greater than 1 meter (m) away from the illumination source. Earlier work from a SBIR Phase 1 entitled 'White Illumination Sources Using Striped Phosphorescent OLEDs' suggests that stripe widths of less than 500 {mu}m appear uniform from a distance of 1m without the need for an external diffuser. In this program, we intend to combine continued advances in this PHOLED technology with the striped RGB lighting design to demonstrate a high-efficiency, white lighting source. Using this background technology, the team has focused on developing and demonstrating the novel cost-effective OVJP process to fabricate these high-efficiency white PHOLED light sources. Because this groundbreaking OVJP process is a direct printing approach that enables the OLED stripes to be printed without a shadow mask, OVJP offers very high material utilization and high throughput without the costs and wastage associated with a shadow mask (i.e. the waste of material that deposits on the shadow mask itself). As a direct printing technique, OVJP also has the potential to offer ultra-high deposition rates (> 1,000 Angstroms/second) for any size or shaped

  1. Charge retention characteristics of silicide-induced crystallized polycrystalline silicon floating gate thin-film transistors for active matrix organic light-emitting diode.

    PubMed

    Park, Jae Hyo; Son, Se Wan; Byun, Chang Woo; Kim, Hyung Yoon; Joo, So Na; Lee, Yong Woo; Yun, Seung Jae; Joo, Seung Ki

    2013-10-01

    In this work, non-volatile memory thin-film transistor (NVM-TFT) was fabricated by nickel silicide-induced laterally crystallized (SILC) polycrystalline silicon (poly-Si) as the active layer. The nickel seed silicide-induced crystallized (SIC) poly-Si was used as storage layer which is embedded in the gate insulator. The novel unit pixel of active matrix organic light-emitting diode (AMOLED) using NVM-TFT is proposed and investigated the electrical and optical performance. The threshold voltage shift showed 17.2 V and the high reliability of retention characteristic was demonstrated until 10 years. The retention t