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Sample records for matrix derivative emd

  1. Cathodic Polarization Coats Titanium Based Implant Materials with Enamel Matrix Derivate (EMD

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    Matthias J. Frank

    2014-03-01

    Full Text Available The idea of a bioactive surface coating that enhances bone healing and bone growth is a strong focus of on-going research for bone implant materials. Enamel matrix derivate (EMD is well documented to support bone regeneration and activates growth of mesenchymal tissues. Thus, it is a prime candidate for coating of existing implant surfaces. The aim of this study was to show that cathodic polarization can be used for coating commercially available implant surfaces with an immobilized but functional and bio-available surface layer of EMD. After coating, XPS revealed EMD-related bindings on the surface while SIMS showed incorporation of EMD into the surface. The hydride layer of the original surface could be activated for coating in an integrated one-step process that did not require any pre-treatment of the surface. SEM images showed nano-spheres and nano-rods on coated surfaces that were EMD-related. Moreover, the surface roughness remained unchanged after coating, as it was shown by optical profilometry. The mass peaks observed in the matrix-assisted laser desorption/ionization time-of-flight mass spectroscopy (MALDI-TOF MS analysis confirmed the integrity of EMD after coating. Assessment of the bioavailability suggested that the modified surfaces were active for osteoblast like MC3M3-E1 cells in showing enhanced Coll-1 gene expression and ALP activity.

  2. The Influence of Arginine on the Response of Enamel Matrix Derivative (EMD Proteins to Thermal Stress: Towards Improving the Stability of EMD-Based Products.

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    Alessandra Apicella

    Full Text Available In a current procedure for periodontal tissue regeneration, enamel matrix derivative (EMD, which is the active component, is mixed with a propylene glycol alginate (PGA gel carrier and applied directly to the periodontal defect. Exposure of EMD to physiological conditions then causes it to precipitate. However, environmental changes during manufacture and storage may result in modifications to the conformation of the EMD proteins, and eventually premature phase separation of the gel and a loss in therapeutic effectiveness. The present work relates to efforts to improve the stability of EMD-based formulations such as Emdogain™ through the incorporation of arginine, a well-known protein stabilizer, but one that to our knowledge has not so far been considered for this purpose. Representative EMD-buffer solutions with and without arginine were analyzed by 3D-dynamic light scattering, UV-Vis spectroscopy, transmission electron microscopy and Fourier transform infrared spectroscopy at different acidic pH and temperatures, T, in order to simulate the effect of pH variations and thermal stress during manufacture and storage. The results provided evidence that arginine may indeed stabilize EMD against irreversible aggregation with respect to variations in pH and T under these conditions. Moreover, stopped-flow transmittance measurements indicated arginine addition not to suppress precipitation of EMD from either the buffers or the PGA gel carrier when the pH was raised to 7, a fundamental requirement for dental applications.

  3. The Influence of Arginine on the Response of Enamel Matrix Derivative (EMD) Proteins to Thermal Stress: Towards Improving the Stability of EMD-Based Products

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    Bolisetty, Sreenath; Marascio, Matteo; Gemperli Graf, Anja; Garamszegi, Laszlo; Mezzenga, Raffaele; Fischer, Peter; Månson, Jan-Anders

    2015-01-01

    In a current procedure for periodontal tissue regeneration, enamel matrix derivative (EMD), which is the active component, is mixed with a propylene glycol alginate (PGA) gel carrier and applied directly to the periodontal defect. Exposure of EMD to physiological conditions then causes it to precipitate. However, environmental changes during manufacture and storage may result in modifications to the conformation of the EMD proteins, and eventually premature phase separation of the gel and a loss in therapeutic effectiveness. The present work relates to efforts to improve the stability of EMD-based formulations such as Emdogain™ through the incorporation of arginine, a well-known protein stabilizer, but one that to our knowledge has not so far been considered for this purpose. Representative EMD-buffer solutions with and without arginine were analyzed by 3D-dynamic light scattering, UV-Vis spectroscopy, transmission electron microscopy and Fourier transform infrared spectroscopy at different acidic pH and temperatures, T, in order to simulate the effect of pH variations and thermal stress during manufacture and storage. The results provided evidence that arginine may indeed stabilize EMD against irreversible aggregation with respect to variations in pH and T under these conditions. Moreover, stopped-flow transmittance measurements indicated arginine addition not to suppress precipitation of EMD from either the buffers or the PGA gel carrier when the pH was raised to 7, a fundamental requirement for dental applications. PMID:26670810

  4. Novel biological activity of ameloblastin in enamel matrix derivative

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    Sachiko KURAMITSU-FUJIMOTO

    2015-02-01

    Full Text Available Objective Enamel matrix derivative (EMD is used clinically to promote periodontal tissue regeneration. However, the effects of EMD on gingival epithelial cells during regeneration of periodontal tissues are unclear. In this in vitro study, we purified ameloblastin from EMD and investigated its biological effects on epithelial cells. Material and Methods Bioactive fractions were purified from EMD by reversed-phase high-performance liquid chromatography using hydrophobic support with a C18 column. The mouse gingival epithelial cell line GE-1 and human oral squamous cell carcinoma line SCC-25 were treated with purified EMD fraction, and cell survival was assessed with a WST-1 assay. To identify the proteins in bioactive fractions of EMD, we used proteome analysis with two-dimensional gel electrophoresis followed by identification with liquid chromatography-tandem mass spectrometry (LC-MS/MS analysis. Results Purified fractions from EMD suppressed proliferation of GE-1 and SCC-25. LC-MS/MS revealed that ameloblastin in EMD is the component responsible for inhibiting epithelial cell proliferation. The inhibitory effect of ameloblastin on the proliferation of GE-1 and SCC-25 was confirmed using recombinant protein. Conclusion The inhibitory effects of EMD on epithelial cell proliferation are caused by the biological activities of ameloblastin, which suggests that ameloblastin is involved in regulating epithelial downgrowth in periodontal tissues.

  5. Enamel matrix protein derivatives: role in periodontal regeneration

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    Rathva VJ

    2011-12-01

    Full Text Available Vandana J RathvaDepartment of Periodontics, KM Shah Dental College and Hospital, Sumandeep University, Gujarat, IndiaAbstract: The role of regenerative periodontal therapy is the reconstitution of lost periodontal structures, ie, new formation of root cementum, periodontal ligament, and alveolar bone. The outcome of basic research has pointed to the important role of enamel matrix protein derivative (EMD in periodontal wound healing. Histologic results from animal and human studies have shown that treatment with EMD promotes periodontal regeneration. Moreover, clinical studies have indicated that treatment with EMD positively influences periodontal wound healing in humans. The goal of this paper is to review the existing literature on EMD.Keywords: enamel matrix protein derivative, Emdogain®, periodontal regeneration

  6. The application of an enamel matrix protein derivative (Emdogain) in regenerative periodontal therapy: a review.

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    Sculean, Anton; Schwarz, Frank; Becker, Jurgen; Brecx, Michel

    2007-01-01

    Regenerative periodontal therapy aims at reconstitution of the lost periodontal structures such as new formation of root cementum, periodontal ligament and alveolar bone. Findings from basic research indicate that enamel matrix protein derivative (EMD) has a key role in periodontal wound healing. Histological results from animal and human studies have shown that treatment with EMD promotes periodontal regeneration. Moreover, clinical studies have indicated that treatment with EMD positively influences periodontal wound healing in humans. This review aims to present an overview of evidence-based clinical indications for regenerative therapy with EMD.

  7. The enamel matrix derivative (Emdogain) enhances human tongue carcinoma cells gelatinase production, migration and metastasis formation.

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    Laaksonen, Matti; Suojanen, Juho; Nurmenniemi, Sini; Läärä, Esa; Sorsa, Timo; Salo, Tuula

    2008-08-01

    Enamel matrix derivative Emdogain (EMD) is widely used in periodontal treatment to regenerate lost connective tissue and to improve the attachment of the teeth. Gelatinases (MMP-2 and -9) have an essential role in the promotion and progression of oral cancer growth and metastasis formation. We studied the effects of EMD on human tongue squamous cell carcinoma (HSC-3) cells in vitro and in vivo. In vitro, EMD (100 microg/ml and 200 microg/ml) remarkably induced the MMP-2 and -9 production from HSC-3 cells analysed by zymography and enzyme-linked immunosorbent assay. EMD also slightly induced the MMP-2 and -9 production from benign human mucosal keratinocytes (HMK). Furthermore, EMD clearly induced the transmigration of HSC-3 cells but had no effect on the HMK migration in transwell assays. The in vitro wound closure of HSC-3 cells was notably accelerated by EMD, whereas it had only minor effect on the wound closure of HMKs. The migration of both cell lines was inhibited by a selective cyclic anti-gelatinolytic peptide CTT-2. EMD had no effect on HSC-3 cell proliferation or apoptosis and only a limited effect on cell attachment to various extracellular matrix components. The in vivo mice experiment revealed that EMD substantially induced HSC-3 xenograft metastasis formation. Our results suggest that the use of EMD for patients with oral mucosal carcinomas or premalignant lesions should be carefully considered, possibly avoided.

  8. Enamel Matrix Derivative Promote Primary Human Pulp Cell Differentiation and Mineralization

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    Elisabeth Aurstad Riksen

    2014-05-01

    Full Text Available Enamel matrix derivative (EMD has been found to induce reactive dentin formation; however the molecular mechanisms involved are unclear. The effect of EMD (5–50 μg/mL on primary human pulp cells were compared to untreated cells and cells incubated with 10−8 M dexamethasone (DEX for 1, 2, 3, 7, and 14 days in culture. Expression analysis using Affymetrix microchips demonstrated that 10 μg/mL EMD regulated several hundred genes and stimulated the gene expression of proteins involved in mesenchymal proliferation and differentiation. Both EMD and DEX enhanced the expression of amelogenin (amel, and the dentinogenic markers dentin sialophosphoprotein (DSSP and dentin matrix acidic phosphoprotein 1 (DMP1, as well as the osteogenic markers osteocalcin (OC, BGLAP and collagen type 1 (COL1A1. Whereas, only EMD had effect on alkaline phosphatase (ALP mRNA expression, the stimulatory effect were verified by enhanced secretion of OC and COL1A from EMD treated cells, and increased ALP activity in cell culture medium after EMD treatment. Increased levels of interleukin-6 (IL-6, interleukin-8 (IL-8, and monocyte chemoattractant proteins (MCP-1 in the cell culture medium were also found. Consequently, the suggested effect of EMD is to promote differentiation of pulp cells and increases the potential for pulpal mineralization to favor reactive dentine formation.

  9. The effect of enamel matrix derivative on spreading, proliferation, and differentiation of osteoblasts cultured on zirconia.

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    Wada, Yoshiyuki; Mizuno, Morimichi; Nodasaka, Yoshinobu; Tamura, Masato

    2012-01-01

    This study investigated the effect of enamel matrix derivative (EMD) on spreading, proliferation, and differentiation of osteoblasts cultured on zirconia disks with smooth and rough surfaces. EMD was added to the culture medium or coated on zirconia disks that had machined (smooth) or sandblasted (rough) surfaces. The effects of EMD on cell proliferation of MC3T3-E1 osteoblastic cells were examined using a hemocytometer. Osteoblastic differentiation was examined by histologic analysis of alkaline phosphatase (ALP) activity and the degree of mineralization. ALP activity was also measured quantitatively. Scanning electron microscopic analysis was performed to observe cell morphology. Enzyme-linked immunosorbent assay of osteocalcin and reverse-transcriptase polymerase chain reaction of osteocalcin, osteopontin, and type 1 collagen were performed to investigate the expression of osteoblast-related genes. The addition of EMD to the medium enhanced the spreading, proliferation, and differentiation of osteoblasts cultured on zirconia. However, when it was coated on zirconia, EMD reduced osteoblastic spreading and adhesion in the early stage of culture, although it enhanced proliferation and differentiation of osteoblasts in later stages. A promotive effect of EMD on osteocalcin mRNA expression, mineralization, and ALP activity of osteoblasts cultured on the rough surface was observed. EMD may contribute to treatment with zirconia implants via its promotion of osteoblastic proliferation and activity. However, the procedure for application of EMD may be a crucial factor for the outcome of implants.

  10. The effect of enamel matrix derivative (Emdogain) on bone formation: a systematic review.

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    Rathe, Florian; Junker, Rüdiger; Chesnutt, Betsy M; Jansen, John A

    2009-09-01

    This systematic review focused on the question, if and to what extent enamel matrix derivative (Emdogain) [EMD]) promotes the regeneration of bone. The influence of combinations with other biomaterials was additionally evaluated. Twenty histomorphometric studies were included in this systematic review. Main results of the reviewed articles were (i) guide tissue regeneration (GTR) of infrabony defects seems to result in a higher degree of bone regeneration compared to treatment with EMD; (ii) combined therapy (GTR + EMD) of infrabony defects might not lead to better results than GTR therapy alone; (iii) there seems to be no additional benefit of combined therapy (GTR + EMD) in furcation defects over GTR therapy alone; (iv) EMD seems to lead to more bone regeneration of infrabony defects compared to open flap debridement; (v) however, EMD application might result in more bone formation when applied in supporting defects compared to nonsupporting defects; and (vi) EMD does not seem to promote external jaw/parietal bone formation in the titanium capsule model. The results of one study that suggest that EMD increases the initial growth of trabecular bone around endosseous implants by new bone induction need to be confirmed by additional research.

  11. Human periodontal ligament fibroblasts stimulated by nanocrystalline hydroxyapatite paste or enamel matrix derivative. An in vitro assessment of PDL attachment, migration, and proliferation

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    Kasaj, A.; Willershausen, B.; Junker, R.; Stratul, S.I.; Schmidt, M.

    2012-01-01

    We determined the effects of soluble or coated nanocrystalline hydroxyapatite paste (nano-HA) and enamel matrix derivative (EMD) on proliferation, adhesion, and migration of periodontal ligament fibroblasts (PDLs). Cultured PDLs were stimulated with nano-HA paste or EMD in a soluble form or were

  12. Enamel matrix derivative Emdogain as an adjuvant for a laterally-positioned flap in the treatment of gingival recession: an electron microscopic appraisal.

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    Lafzi, A; Farahani, R M; Tubbs, R S; Roushangar, L; Shoja, M M

    2007-05-01

    Enamel matrix derivative (EMD), such as Emdogain, has been suggested for the improvement of wound healing in periodontal surgical therapy. The present qualitative study seeks to illustrate the ultrastructural changes associated with a human gingival wound at 10 days after the application of EMD as an adjunct to a laterally-positioned flap in a patient with gingival recession. An otherwise healthy patient, who had been suffering from bilateral gingival recession defects on teeth #23 and #26, was studied. One defect was treated with a laterally-positioned flap, while the other was treated with a combination of EMD and a laterally-positioned flap. Ten days after the operation gingival biopsy specimens were obtained from the dentogingival region and examined using a transmission electron microscope. A considerable difference was found in both the cellular and extracellular phases of EMD and non-EMD sites. The fibroblasts of EMD site were more rounded with plump cytoplasms and euchromatic nuclei. A well-developed rough endoplasmic reticulum and numerous mitochondria could be detected. In contrast, the fibroblasts of non-EMD site were of flattened spindle-like morphology. While the signs of apoptosis could rarely be detected at EMD site, apoptotic bodies and ultra-structural evidence of apoptosis (crescent-like heterochromatic nuclei and dilated nuclear envelopes) were consistent features at non-EMD site. The extracellular matrix at EMD site mainly consisted of well-organised collagen fibres, while non-EMD site contained sparse and incompletely-formed collagen fibres. Coccoid bacteria were noted within the extracellular matrix and neutrophils at non-EMD site. It seems that EMD may enhance certain features of gingival wound healing, which may be attributable to its anti-apoptotic, anti-bacterial or anti-inflammatory properties.

  13. Effects of enamel matrix derivative and transforming growth factor-β1 on human osteoblastic cells

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    Rosa Adalberto L

    2011-07-01

    Full Text Available Abstract Background Extracellular matrix proteins are key factors that influence the regenerative capacity of tissues. The objective of the present study was to evaluate the effects of enamel matrix derivative (EMD, TGF-β1, and the combination of both factors (EMD+TGF-β1 on human osteoblastic cell cultures. Methods Cells were obtained from alveolar bone of three adult patients using enzymatic digestion. Effects of EMD, TGF-β1, or a combination of both were analyzed on cell proliferation, bone sialoprotein (BSP, osteopontin (OPN and alkaline phosphatase (ALP immunodetection, total protein synthesis, ALP activity and bone-like nodule formation. Results All treatments significantly increased cell proliferation compared to the control group at 24 h and 4 days. At day 7, EMD group showed higher cell proliferation compared to TGF-β1, EMD + TGF-β1 and the control group. OPN was detected in the majority of the cells for all groups, whereas fluorescence intensities for ALP labeling were greater in the control than in treated groups; BSP was not detected in all groups. All treatments decreased ALP levels at 7 and 14 days and bone-like nodule formation at 21 days compared to the control group. Conclusions The exposure of human osteoblastic cells to EMD, TGF-β1 and the combination of factors in vitro supports the development of a less differentiated phenotype, with enhanced proliferative activity and total cell number, and reduced ALP activity levels and matrix mineralization.

  14. Furcation Therapy With Enamel Matrix Derivative: Effects on the Subgingival Microbiome.

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    Queiroz, Lucas A; Casarin, Renato C V; Dabdoub, Shareef M; Tatakis, Dimitris N; Sallum, Enilson A; Kumar, Purnima S

    2017-07-01

    Although enamel matrix derivative (EMD) has been used to promote periodontal regeneration, little is known of its effect on the microbiome. Therefore, this investigation aims to identify changes in periodontal microbiome after treatment with EMD using a deep-sequencing approach. Thirty-nine patients with mandibular Class II buccal furcation defects were randomized to beta-tricalcium-phosphate/hydroxyapatite graft (BONE group), EMD+BONE, or EMD alone. Plaque was collected from furcation defects at baseline and 3 and 6 months post-treatment. Bacterial DNA was analyzed using terminal restriction fragment length polymorphism and 16S pyrotag sequencing, resulting in 169,000 classifiable sequences being compared with the Human Oral Microbiome Database. Statistical comparisons were made using parametric tests. At baseline, a total of 422 species were identified from the 39 defects, belonging to Fusobacterium, Pseudomonas, Streptococcus, Filifactor, and Parvimonas. All three regenerative procedures predictably altered the disease-associated microbiome, with a restitution of health-compatible species. However, EMD and BONE+EMD groups demonstrated more long-term reductions in a higher number of species than the BONE group (P <0.05), especially disease-associated species, e.g., Selenomonas noxia, F. alocis, and Fusobacterium. EMD treatment predictably alters a dysbiotic subgingival microbiome, decreasing pathogen richness and increasing commensal abundance. Further investigations are needed to investigate how this impacts regenerative outcomes.

  15. Effect of different enamel matrix derivative proteins on behavior and differentiation of endothelial cells.

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    Andrukhov, Oleh; Gemperli, Anja C; Tang, Yan; Howald, Nadia; Dard, Michel; Falkensammer, Frank; Moritz, Andreas; Rausch-Fan, Xiaohui

    2015-07-01

    Enamel matrix derivative (EMD) is an effective biomaterial for periodontal tissue regeneration and might stimulate angiogenesis. In order to clarify mechanisms underlying its biological activity, we separated two EMD fractions with different molecular weight protein components and investigated their effects on human umbilical vein endothelial cells (HUVECs) in vitro. Fraction Low-Molecular Weight (LMW) included proteins with a molecular weight (M.W.)8kDa and lower than approximately 55kDa. The effect of EMD fractions on proliferation/viability, apoptosis, migration and expression of angiopoetin-2 (ang-2), von Willebrand factor (vWF), E-selectin, intracellular adhesion molecules 1 (ICAM-1), vascular endothelial growth factor (VEGF) receptors Flt-1 and KDR was investigated. The proliferation/viability of HUVECs was inhibited by both LMW and LMW-depleted at concentrations 100μg/ml, whereas EMD slightly increased cell proliferation/viability. The expression of all investigated proteins was up-regulated by EMD. However, differences in the effect of EMD fractions on the protein expression were observed. The effect of LMW-depleted on the expression of ICAM-1 and E-selectin was markedly higher compared to LMW. In contrast, the expression of vWF and VEGF receptors Flt-1 and KDR was primarily affected LMW than by LMW depleted. The expression of ang-2 was not influenced by LMW and LMW-depleted. HUVECs migration was stimulated more strongly by LMW than by EMD and LMW-depleted. Our in vitro study shows that the proteins composing EMD have different and specific biological activities and consequently have the ability to cover different aspects of EMD's biological and clinical effects. Copyright © 2015 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  16. Effects of the enamel matrix derivative on the proliferation and odontogenic differentiation of human dental pulp cells.

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    Wang, Yuanyuan; Zhao, Yuming; Ge, Lihong

    2014-01-01

    The enamel matrix derivative (EMD) has a positive effect on the proliferation of human periodontal ligament cells and the healing of periodontal tissues. The aim of this study was to evaluate the effects of EMD on the proliferation and differentiation of human dental pulp cells (hDPCs) in vitro. hDPCs were isolated from human impacted third molars and cultured in vitro. After treatment with100μg/mL EMD, the proliferation of hDPCs was determined by a cell counting kit 8 (CCK8) assay. After incubation in EMD osteogenic induction medium for 14 days, the osteogenic differentiation of hDPCs was evaluated by alkaline phosphatase (ALP) activity, alizarin staining and the expression of osteogenesis-related genes. The EMD osteogenic induction medium enhanced the proliferation of hDPCs. After osteogenic induction, EMD increased the osteogenic potential of hDPCs, as measured by alkaline phosphatase activity and calcium accumulation; the expression levels of osteogenesis-related genes, such as ALP, DSPP, BMP, and OPN were also upregulated. In addition, the expression levels of odontogenesis-related transcription factors Osterix and Runx2 were upregulated. EMD could enhance the mineralization of hDPSCs upregulated the expression of markers for odontoblast/osteoblast-like cells. Further studies are required to determine if EMD can improve pulp tissue repair and regeneration. Copyright © 2013. Published by Elsevier Ltd.

  17. Histologic evaluation of effectiveness of Enamel Matrix Derivative in surgical defect of sheep tooth

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    Pak Nejad M.

    2001-09-01

    Full Text Available "nAbstract: The aim of the present study was the histological evaluation of Enamel Matrix Derivative (EMD effectiveness for regeneration of periodontal defects. EMD activates cementum synthesis, PDL and bone during the maturation stage of follicole. In this research, EMD was used in surgical defects of premolar teeth in four adult sheep. Muccoperiosteal flap was reflected in buccal site of teeth. The buccal bone plate was removed from mesial to distal in 4 mm depth. After eliminating the cementum by bur and its etching, EMD was applied on exposed dentine and flap was sutured. In opposite sites of those teeth (control sites the same process was performed without etching. After 100 days, sheep were sacrificed and histological study through light microscopic was performed on black sections of operation sites. The results showed that in test sites, regeneration of cementum and bone was 62/5% and 42/5-50% respectively. But in control sites regeneration of cementum and bone was 37.5% and 32/5-42/5% respectively. Also the migration of junctional epithelium in control sites was 8-10% more than test sites. The important point is that in test sites, cementum was completely attached to undermining dentine. But, in control sites, the gap between cementum and dentine was visible. As a result, this study suggests that EMD promotes periodontal regeneration, and EMD application is a successful achievement in regenerative periodontal therapy.

  18. Comparison of enamel matrix derivative versus formocresol as pulpotomy agents in the primary dentition.

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    Sabbarini, Jumana; Mohamed, Ahmed; Wahba, Nadia; El-Meligy, Omar; Dean, Jeffrey

    2008-03-01

    The purpose of this study was to compare the clinical and radiographic success rates of two different pulpotomy agents: one novel agent, the biologically active odontogenic protein enamel matrix derivative (EMD) versus formocresol (FC). A randomized, single-blind, split-mouth study was used with a sample of 15 children aged 4 to 7 years (mean age, 5 +/- 0.73 years). A total of 15 pairs of teeth, 1 pair per child, were selected for treatment. One tooth from each pair was randomly assigned to either the EMD pulpotomy group or the FC pulpotomy group. All teeth were followed up clinically and radiographically at 2, 4, and 6 months. After 6 months, the clinical success rates for the FC and EMD groups were 67% and 93%, respectively. Although most likely clinically relevant, the clinical success rate difference after 6 months was not statistically significant. After 6 months, the radiographic success rates for the FC and EMD groups were 13% and 60 %, respectively. There was a statistically significant difference at p < or = 0.05. The clinical and radiographic assessment of EMD pulpotomized teeth in this study offers preliminary evidence that EMD is a promising material which may be as successful, or more so, than other pulpotomy agents.

  19. The application of an enamel matrix protein derivative (Emdogain) in regenerative periodontal therapy: a review.

    NARCIS (Netherlands)

    Sculean, A.; Schwarz, F.; Becker, J.; Brecx, M.

    2007-01-01

    Regenerative periodontal therapy aims at reconstitution of the lost periodontal structures such as new formation of root cementum, periodontal ligament and alveolar bone. Findings from basic research indicate that enamel matrix protein derivative (EMD) has a key role in periodontal wound healing. Hi

  20. The effect of enamel matrix derivative (Emdogain) on bone formation: a systematic review.

    NARCIS (Netherlands)

    Rathe, F.; Junker, R.; Chesnutt, B.C.; Jansen, J.A.

    2009-01-01

    This systematic review focused on the question, if and to what extent enamel matrix derivative (Emdogain) [EMD]) promotes the regeneration of bone. The influence of combinations with other biomaterials was additionally evaluated. Twenty histomorphometric studies were included in this systematic revi

  1. A REVIEW ON EFFECTIVE APPLICATION OF AN ENAMEL MATRIX DERIVATIVE (EMDOGAIN® FOR PERIODONTAL SURGERY IN THE PRESENCE OF BLOOD

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    Oana M. CALUSERU

    2013-06-01

    Full Text Available Reconstructive periodontal surgery aims at predictably restoring tooth’s supporting structure lost due to perio‐ dontal disease or trauma. One such modality, which has been demonstrate to promote periodontal regeneration, is an enamel matrix derivative (EMD, consisting of a formu‐ lation of amelogenin proteins from developing porcine enamel. This review article provides a brief update on the effects of blood interaction, occurring during periodontal surgery, on the effectiveness of EMD adsorption on the root surfaces and its implications for periodontal recon‐ structive surgery.The clinical use of an enamel matrix derivative (EMD has been successfully proved in periodontal surgery, as promoting regeneration of periodontal tissues including new cementum, periodontal ligament (PDL and alveolar bone [1]. Despite its widespread use, only recently has the effect of blood, occurring during periodontal surgery, been evaluated for contamination of the effectiveness of EMD adsorption onto root surfaces. The aim of this review arti‐ cle is to provide the clinician a summary of findings from in vitro experiments testing the effects of EMD adsorption onto root surfaces in the presence and absence of blood and its effect on PDL cell behavior [2]. Until recently, the extent to which bleeding occurring during periodontal sur‐ gery affects the adsorption of EMD onto root surfaces could not be established.In summary, the teeth extracted for orthodontic reasons were subject to ex vivo scaling and root planing and expo‐ sed to 6 clinically relevant scenarios, as illustrated in figure 1. EMD application is usually performed following root surface conditioning with 24% EDTA. Findings from high resolution scanning electron microscopy (SEM demons‐ trated that the proteins found in blood (mainly albumin were able to compete with those found in EMD (Figure 2, reducing the effectiveness of EMD thereafter. No apparent effect of conditioning the surface

  2. Osteoblast response (initial adhesion and alkaline phosphatase activity following exposure to a barrier membrane/enamel matrix derivative combination

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    Thangakumaran S

    2009-01-01

    Full Text Available Background and Objective: The enamel matrix derivative (EMD has been used in combination with barrier membranes to optimize regeneration in vertical osseous defects. However, the osteoblast response when exposed to the EMD/barrier membrane combination has not yet been evaluated. The osteoblast behavior when exposed to a combination of regenerative materials must be evaluated to fully understand their effect on bone regeneration. Therefore, the present study was undertaken to estimate the initial adhesion and alkaline phosphatase (ALP activity of an osteoblast cell line (SaOS-2 when exposed to four commercially available resorbable membranes and determine if the addition of EMD had any modulatory effect on osteoblast behavior. Materials and Methods: 5 x 104 SaOS-2 cells between passages 7-10 were cultured in two 24-well culture plates. Plate A was used for the adhesion assay and Plate B was used for the ALP assay. A MTT (3-[4, 5-dimethylthiazolyl-2]-2, 5-diphenyltetrazolium bromide assay was done after 24 hours to determine the adhesion of the osteoblastic cells to four barrier membranes: 1 a non cross-linked porcine Type I and III collagen membrane (BG, 2 a weakly cross-linked Type I collagen membrane (HG, 3 a glutaraldehyde cross-linked bovine Type I collagen (BM, and 4 a resorbable polymer membrane (CP. Osteoblast differentiation was studied using an ALP assay with p-nitro phenyl phosphate as the substrate at 24 hours, 72 hours, and 1 week. A total of 50 µg/ml of EMD dissolved in 10 mM acetic acid was added into each well and the entire experimental protocol outlined above was repeated. Results: The osteoblast adhesion to collagen barriers showed a statistically insignificant reduction following the addition of EMD. Adhesion to the polymer barrier, although significantly lower when compared with collagen barriers, was unaffected by the addition of EMD. ALP activity after 1 week among the various groups was as follows: EMD alone (75.59±2

  3. Adsorption of enamel matrix proteins to a bovine-derived bone grafting material and its regulation of cell adhesion, proliferation, and differentiation.

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    Miron, Richard J; Bosshardt, Dieter D; Hedbom, Erik; Zhang, Yufeng; Haenni, Beat; Buser, Daniel; Sculean, Anton

    2012-07-01

    The use of various combinations of enamel matrix derivative (EMD) and grafting materials has been shown to promote periodontal wound healing/regeneration. However, the downstream cellular behavior of periodontal ligament (PDL) cells and osteoblasts has not yet been studied. Furthermore, it is unknown to what extent the bleeding during regenerative surgery may influence the adsorption of exogenous proteins to the surface of bone grafting materials and the subsequent cellular behavior. In the present study, the aim is to test EMD adsorption to the surface of natural bone mineral (NBM) particles in the presence of blood and determine the effect of EMD coating to NBM particles on downstream cellular pathways, such as adhesion, proliferation, and differentiation of primary human osteoblasts and PDL cells. NBM particles were precoated in various settings with EMD or human blood and analyzed for protein adsorption patterns via fluorescent imaging and high-resolution immunocytochemistry with an anti-EMD antibody. Cell attachment and cell proliferation were quantified using fluorescent double-stranded DNA-binding dye. Cell differentiation was analyzed using real-time polymerase chain reaction for genes encoding runt-related transcription factor 2, alkaline phosphatase (ALP), osteocalcin (OC), and collagen1α1 (COL1A1), and mineralization was assessed using red dye staining. Analysis of cell attachment and cell proliferation revealed significantly higher osteoblast and PDL cell attachment on EMD-coated surfaces when compared with control and blood-coated surfaces. EMD also stimulated release of growth factors and cytokines, including bone morphogenetic protein 2 and transforming growth factor β1. Moreover, there were significantly higher mRNA levels of osteoblast differentiation markers, including COL1A1, ALP, and OC, in osteoblasts and PDL cells cultured on EMD-coated NBM particles. The present results suggest that 1) EMD enhances osteoblast and PDL cell attachment

  4. Enamel Matrix Derivative Stimulates Osteogenesis-and Chondrogenesis-related Transcription Factors in C3H10T1/2 Cells

    Institute of Scientific and Technical Information of China (English)

    Masataka NARUKAWA; Naoto SUZUKI; Tadahiro TAKAYAMA; Yasuhiko YAMASHITA; Kichibee OTSUKA; Koichi ITO

    2007-01-01

    Our purpose was to determine how enamel matrix derivative (EMD) affects the expression of osteogenesis-and chondrogenesis-related transcription factors in undifferentiated mesenchymal cells.C3H10T1/2 cell line, a typical pluripotential mesenchymal cell line, was cultured with or without EMD for up to 7 d. Expression of mRNAs encoding osteogenesis-and chondrogenesis-related transcription factors(Runx2, Osterix, AJ18, Dlx5, Msx2, Sox5, Sox9 and Zfp60) was measured using real-time polymerase chain reaction. Runx2 and Sox9 protein expression and the presence of bone morphogenetic protein (BMP)-6-like molecules in EMD were determined by Western blotting. EMD substantially increased mRNA levels of osteogenesis-and chondrogenesis-related transcription factors. EMD also induced Runx2 and Sox9 protein expression. Western blotting analysis of EMD using anti-BMP-6 antibody revealed immunoreactive bands corresponding to about 14 kDa and 60 kDa. These results suggest that EMD stimulates osteogenesis-and chondrogenesis-related transcription factors, and these activities may be mediated, at least in part, by BMP-6in EMD.

  5. Efficacy of enamel matrix derivatives (Emdogain) in treatment of replanted teeth--a systematic review based on animal studies.

    Science.gov (United States)

    Wiegand, Annette; Attin, Thomas

    2008-10-01

    The objective of the current systematic review was to evaluate the efficacy of enamel matrix derivative (EMD) (Emdogain) on healing of replanted or autotransplanted permanent teeth. A review of the published literature [search term: (Emdogain OR enamel matrix derivative OR enamel matrix protein] AND [avulsion OR replantation OR autotransplantation)] was conducted by two independent investigators according to defined selection criteria. For data extraction of the identified animal studies, the following histomorphometric findings were considered: (i) healed PDL, (ii) surface resorption, (iii) inflammatory resorption and (iv) replacement resorption. The heterogeneity of data collection and the small amount of identified publications did not allow for statistical analysis. Four controlled trials (CT) conducted in animals, but no randomized controlled trials (RCT) or clinical controlled trials (CCT) could be received from the systematic search. From the selected studies, two CT gave evidence of EMD treatment to be effective in inducing healing of replanted teeth, while one CT found no differences between EMD treated teeth and controls. Finally, one CT compared EMD and sodium fluoride application, but revealed no differences between the treatments. The data of controlled trials available are limited and conflicting. No firm conclusion regarding the efficacy of EMD application on healing of replanted or autotransplanted permanent teeth can be drawn because of lack of RCT and CCT.

  6. Nine-year results following treatment of intrabony periodontal defects with an enamel matrix derivative: report of 26 cases.

    NARCIS (Netherlands)

    Sculean, A.; Schwarz, F.; Chiantella, G.C.; Arweiler, N.B.; Becker, J.

    2007-01-01

    Treatment of intrabony periodontal defects with an enamel matrix derivative (EMD) has been demonstrated, in the short term, to result in periodontal regeneration and to significantly improve clinical parameters such as probing depth (PD) and clinical attachment level (CAL). The present study evaluat

  7. A comparative study on treatment of two and three walled periodontal bony defects utilizing open flap debridement with and without enamel matrix derivatives

    Directory of Open Access Journals (Sweden)

    Soleimani Shayesteh Y.

    2006-08-01

    Full Text Available Background and Aim: Intrabony periodontal defects are important problems in periodontology and up to now several ways have been suggested for their treatment .Treatment with enamel matrix derivatives (EMD has been shown to enhance periodontal regeneration. There is limited information available from clinical trials regarding the performance of EMD in the treatment of periodontal intrabony defects. This study was designed to compare the clinical and radiographic effects of EMD treatment to that of open flap debridment (OFD for two and three walled intrabony defects. Materials and Methods: 18 patients were included in this clinical trial which have 24 two and/ or three intrabony defects. Defects were randomly divided into two groups (test and control. Defects in test group were treated with flap surgery plus EMD and in control group with open flap debridment. At baseline and at 3 and 6 months follow up, clinical and radiographic measurements were performed. Data were analyzed using Greenhouse-Geisser test with p<0.05 as the limit of significance. Results: At 3 and 6 months, mean probing pocket depth reduction was greater in the test group (EMD (4.33 mm and 4.70 mm compared to the OFD group (2.54 mm and 3.09 mm. Mean values for clinical attachment gain in the EMD group after 3 and 6 months were 4.29 mm and 4.98 mm, and in OFD group were 2.83 and 2.82 mm respectively. Radiographic bone gain measured by radiovisiography technique was greater in the EMD group compared to the OFD group (4.66 mm in EMD and 1.11 mm in OFD group after 3 months and 5.78 mm in EMD and 1.39 mm in OFD group after 6 months. Conclusion: Based on the results of this study, treatment with flap surgery and EMD compared to open flap debridment, produced more favorable clinical improvements in two and three walled intrabony defects.

  8. The effects of bone morphogenetic protein-2 and enamel matrix derivative on the bioactivity of mineral trioxide aggregate in MC3T3-E1cells

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    Youngdan Jeong

    2014-08-01

    Full Text Available Objectives The effects of bone morphogenetic protein-2 (BMP-2 and enamel matrix derivative (EMD respectively with mineral trioxide aggregate (MTA on hard tissue regeneration have been investigated in previous studies. This study aimed to compare the osteogenic effects of MTA/BMP-2 and MTA/EMD treatment in MC3T3-E1 cells. Materials and Methods MC3T3-E1 cells were treated with MTA (ProRoot, Dentsply, BMP-2 (R&D Systems, EMD (Emdogain, Straumann separately and MTA/BMP-2 or MTA/EMD combination. Mineralization was evaluated by staining the calcium deposits with alkaline phosphatase (ALP, Sigma-Aldrich and Alizarin red (Sigma-Aldrich. The effects on the osteoblast differentiation were evaluated by the expressions of osteogenic markers, including ALP, bone sialoprotein (BSP, osteocalcin (OCN, osteopontin (OPN and osteonectin (OSN, as determined by reverse-transcription polymerase chain reaction analysis (RT-PCR, AccuPower PCR, Bioneer. Results Mineralization increased in the BMP-2 and MTA/BMP-2 groups and increased to a lesser extent in the MTA/EMD group but appeared to decrease in the MTA-only group based on Alizarin red staining. ALP expression largely decreased in the EMD and MTA/EMD groups based on ALP staining. In the MTA/BMP-2 group, mRNA expression of OPN on day 3 and BSP and OCN on day 7 significantly increased. In the MTA/EMD group, OSN and OCN gene expression significantly increased on day 7, whereas ALP expression decreased on days 3 and 7 (p < 0.05. Conclusions These results suggest the MTA/BMP-2 combination promoted more rapid differentiation in MC3T3-E1 cells than did MTA/EMD during the early mineralization period.

  9. Study on GA-BP inversing modeling method of corn leaf chlorophyll content based on EMD and spectral derivative method%基于EMD-SD光谱的玉米叶片叶绿素含量GA-BP模型反演

    Institute of Scientific and Technical Information of China (English)

    张婉婉; 杨可明; 汪国平; 刘二雄; 刘聪

    2016-01-01

    The chlorophyll is the main pigment for the photosynthesis of crops. The BPNN is a novel method of inver-sing chlorophyll content. In order to study chlorophyll content inversion model with higher precision, it was used to increase the correlation between input factors and chlorophyll content by combining empirical mode decomposition (EMD) with spectral derivative (SD). And genetic algorithm(GA) was used to optimize BPNN building GA-BP model to get the best initial weights and thresholds. The spectral reflectance of corn leaf was pretreated by the meth-ods of EMD and derivative, getting the EMD-SD spectrum. It was selected as the input factors of GA-BP model that the EMD-SD values in five bands whose correlation coefficients with chlorophyll content were over 0. 6. Then the GA-BP model with seven hidden layer nodes was established, selecting the network whose fitness of the best individual was the lowest to predict the chlorophyll content of corn leaf. R2 of GA-BP model was the highest, at 0. 818, RMSE was 2. 442 and e was 5. 436%. The results showed that the predicting precision of GA-BP model using EMD-SD val-ues as input factors was higher than MLR and BP model. It was verified feasible that using GA-BP model based on EMD-SD spectrum to improve the inversion accuracy of corn leaf chlorophyll content.%叶绿素是作物进行光合作用所需的主要色素,BP神经网络( BPNN)是较为新颖的反演叶绿素含量的方法。为研究反演精度更高的叶绿素含量反演模型,将经验模态分解( EMD)与光谱微分( SD)结合来提高输入因子与叶绿素含量的相关性,并使用遗传算法( GA)优化BPNN得到GA-BP模型以获得最优初始权值阈值。将光谱数据EMD后进行一阶微分变换得到EMD-SD光谱,选择与叶绿素含量相关系数超过0.6的5个波段处的EMD-SD值作为GA-BP模型的输入因子,隐含层节点数为7,多次训练取最优个体适应度值最低的GA-BP模型来反演

  10. The effects of enamel matrix derivative and cyclic mechanical strain on human gingival fibroblasts in an in vitro defect healing model.

    Science.gov (United States)

    Sanders, Jill E; Chuang, Augustine; Swiec, Gary D; Bisch, Fredrick C; Herold, Robert W; Buxton, Thomas B; McPherson, James C

    2011-01-01

    Gingival fibroblasts (GFs) play a considerable role in the maintenance of the gingival apparatus as well as in connective tissue repair. Mobility of a periodontal wound or soft tissue graft can impair connective tissue healing from the GFs. Enamel matrix derivative (EMD) is an enamel matrix protein used clinically for periodontal regeneration of intrabony defects and furcations, as well as treatment of gingival margin recessions. The goal of this project was to compare the effects of varying concentrations of EMD, with and without cyclic mechanical strain, on cellular wound fill of human GFs using an in vitro defect healing model. GFs were seeded and cultured in six-well flexible-bottomed plates. A 3-mm wound was created in the central portion of each confluent well. Three wells were treated with each EMD concentration of 0 Μg/mL (control), 30 Μg/mL, 60 Μg/mL, or 120 Μg/mL. The plates were placed in an incubator containing a strain unit to subject test plates to cyclic strain. An identical set of control plates were not flexed. Cells were examined on days 4, 8, 12, and 16. Microphotographs were taken and wound fill measurements made using image analysis software. The percent wound fill was calculated. All nonflexed plates, regardless of EMD concentration, reached > 90% defect fill at similar rates by day 16. However, in the flexed plates, EMD had a significant negative effect on defect fill. The defect fill was 55.7% for 0 Μg/mL EMD, 48.2% for 30 Μg/mL EMD, 36.7% for 60 Μg/mL EMD, and 34.1% for 120 Μg/mL EMD on day 16 for the flexed GFs. EMD, in concentrations as high as 120 Μg/mL, did not significantly affect the amount of defect fill with nonflexed GFs. However, when the GFs were flexed, the addition of EMD had a significant negative effect on defect fill in a dose-dependent manner.

  11. The Effect of an Enamel Matrix Derivative (Emdogain Combined with Bone Ceramic on Bone Formation in Mandibular Defects: A Histomorphometric and Immunohistochemical Study in the Canine

    Directory of Open Access Journals (Sweden)

    Reza Birang

    2012-01-01

    Full Text Available Background. The purpose of this study was to evaluate the combination of an enamel matrix derivative (EMD and an osteoconductive bone ceramic (BC in improving bone regeneration. Materials and Methods. Four cylindrical cavities (6×6mm were prepared bilaterally in the mandible in three dogs. The defects were randomly assigned to four different treatments—filled with EMD/BC and covered with a nonresorbable membrane, filled with EMD/BC without membrane, membrane coverage only, or control (left untreated—and healed for 2, 4, or 6 weeks. Harvested specimens were prepared for histologic, histomorphometric, and immunohistochemical analyses. Results. Sites treated with EMD/BC with or without membrane showed more total bone formation and lamellar bone formation than membrane-only and control defects. There were no statistically significant differences in total bone formation between EMD/BC with or without membrane. Conclusion. EMD with BC might improve bone formation in osseous defects more than membrane coverage alone; the use of a membrane had no significant additive effect on total bone formation.

  12. Treatment of intrabony defects with an enamel matrix protein derivative or bioabsorbable membrane: an 8-year follow-up split-mouth study.

    NARCIS (Netherlands)

    Sculean, A.; Schwarz, F.; Miliauskaite, A.; Kiss, A.; Arweiler, N.B.; Becker, J.M.; Brecx, M.

    2006-01-01

    BACKGROUND: Treatments with either an enamel matrix protein derivative (EMD) or guided tissue regeneration (GTR) have been shown to promote periodontal regeneration. However, until recently, only limited data have been available on the long-term clinical results following these regenerative techniqu

  13. Clinical and histologic evaluation of an enamel matrix protein derivative combined with a bioactive glass for the treatment of intrabony periodontal defects in humans.

    NARCIS (Netherlands)

    Sculean, A.; Windisch, P.; Keglevich, T.; Gera, I.

    2005-01-01

    The present study clinically and histologically evaluated healing of human intrabony defects following treatment with a combination of enamel matrix derivative (EMD) and bioactive glass (BG) or BG alone. Six patients displaying either combined one- and two-walled (five patients) or three-walled (one

  14. Evaluation of the effectiveness of enamel matrix derivative, bone grafts, and membrane in the treatment of mandibular Class II furcation defects.

    Science.gov (United States)

    Jaiswal, Ritika; Deo, Vikas

    2013-01-01

    The combination of osseous graft with barrier membrane and enamel matrix protein derivative (EMD) has the potential to result in a synergistic effect. Therefore, the aim of this study was to evaluate the effectiveness of EMD in combination with demineralized freeze-dried bone allograft (BG) and bioresorbable membrane (Biomesh) in the treatment of human mandibular Class II furcation defects over a period of 12 months. Thirty patients with chronic periodontitis and a single Class II furcation defect on the buccal or lingual surface of mandibular teeth were included. The clinical parameters evaluated were probing pocket depth (PPD), horizontal probing depth (HPD), vertical relative attachment level (V-RAL), and relative gingival margin level (RGML). three groups were created based on treatment method: EMD + BG + guided tissue regeneration (GTR), BG + GTR, and open flap debridement (OFD). All three groups showed a statistically significant PPD reduction of 1.74 ± 1.00 mm, 0.81 ± 0.31 mm, and 0.46 ± 0.52 mm at 12 months postsurgery. EMD + BG + GTR showed a significantly greater PPD reduction compared with BG + GTR, as well as OFD. EMD + BG + GTR showed a statistically significant vertical clinical attachment gain of 2.12 ± 1.07 mm at 12 months compared with BG + GTR as well as OFD. Significant reductions in mean HPD were observed for EMD + BG + GTR (2.10 mm) as well as BG + GTR (1.5 mm). The number of Class II furcation defects that closed or converted to Class I was greatest for EMD + BG + GTR. It can be concluded that EMD + BG + GTR resulted in a statistically significant reduction of PPD, V-RAL gain, and a nonsignificantly greater reduction of HPD compared to BG + GTR.

  15. Effect of Emdogain enamel matrix derivative and BMP-2 on the gene expression and mineralized nodule formation of alveolar bone proper-derived stem/progenitor cells.

    Science.gov (United States)

    Fawzy El-Sayed, Karim M; Dörfer, Christof; Ungefroren, Hendrick; Kassem, Neemat; Wiltfang, Jörg; Paris, Sebastian

    2014-07-01

    The objective of this study was to evaluate the effect of Emdogain (Enamel Matrix Derivative, EMD) and Bone Morphogenetic Protein-2 (BMP-2), either solely or in combination, on the gene expression and mineralized nodule formation of alveolar bone proper-derived stem/progenitor cells. Stem/progenitor cells were isolated from human alveolar bone proper, magnetically sorted using STRO-1 antibodies, characterized flowcytometrically for their surface markers' expression, and examined for colony formation and multilineage differentiation potential. Subsequently, cells were treated over three weeks with 100 μg/ml Emdogain (EMD-Group), or 100 ng/ml BMP-2 (BMP-Group), or a combination of 100 ng/ml BMP-2 and 100 μg/ml Emdogain (BMP/EMD-Group). Unstimulated stem/progenitor cells (MACS(+)-Group) and osteoblasts (OB-Group) served as controls. Osteogenic gene expression was analyzed using RTq-PCR after 1, 2 and 3 weeks (N = 3/group). Mineralized nodule formation was evaluated by Alizarin-Red staining. BMP and EMD up-regulated the osteogenic gene expression. The BMP Group showed significantly higher expression of Collagen-I, III, and V, Alkaline phosphatase and Osteonectin compared to MACS(+)- and OB-Group (p Emdogain and BMP-2 up-regulate the osteogenic gene expression of stem/progenitor cells. The combination of BMP-2 and Emdogain showed no additive effect and would not be recommended for a combined clinical stimulation.

  16. The coronally advanced flap in combination with platelet-rich fibrin (PRF) and enamel matrix derivative in the treatment of gingival recession: a comparative study.

    Science.gov (United States)

    Jankovic, Sasha; Aleksic, Zoran; Milinkovic, Iva; Dimitrijevic, Bozidar

    2010-01-01

    The main objective of this study was to evaluate the clinical effectiveness of platelet-rich fibrin membrane used in combination with a coronally advanced flap (CAF) and to compare it with the use of an enamel matrix derivative (EMD) in combination with a coronally advanced flap in gingival recession treatment. 20 split-mouth cases of maxillary anterior teeth or bicuspids presenting with Miller Class I or II gingival recession were treated with a CAF combined with a platelet-rich fibrin membrane (PRF group) or with EMD (EMD group) placed under a CAF. The following parameters were measured at baseline and at 12 months post treatment: gingival recession (GR), apicocoronal width of the keratinized tissue (WKT), and probing depth (PD). Complete rot coverage in the PRF group was 65% (13 out of 20 recessions) and 60% in the EMD group (12 out of 20 recessions). GR was 4.10 ± 1.05 mm in the PRF group and 3.90 ± 1.00 mm in the EMD group at baseline, and 1.05 ± 0.45 mm in the PRF group and 1.15 ± 0.65 mm in the EMD group at 12 months. The difference observed between the tow groups at 12 months was statistically significant. Average root coverage was 70.5% in the EMD group and 72.1% in the PRF group. WKT was 1.30 ± 0.56 mm in the EMD group and 1.45 ± 0.86 mm in the PRF group at baseline, and 1.90 ± 0.81 mm in the EMD group and 1.62 ± 0.28 mm in the PRF group at 12 months. The difference observed between the two groups at 12 months was not statistically significant. Twelve-month changes in PD were not significantly different between the two groups. The pain intensity was statistically different between the two groups. The pain intensity was statistically different between groups for the first 5 days, favoring the PRF group. The present study did not succeed in demonstrating any clinical advantage of the use of PRF compared to EMD in the coverage of gingival recession with the CAF procedure. The EMD group showed a higher success rate in increasing WKT than did the PRF

  17. Clinical evaluation of a combined regenerative technique with enamel matrix derivative, bone grafts, and guided tissue regeneration.

    Science.gov (United States)

    Harris, Randall J; Harris, Laura E; Harris, Christopher R; Harris, Anne J

    2007-04-01

    The goal of this study was to evaluate the clinical changes obtained when intra-bony defects were treated with an enamel matrix derivative (EMD), a bone graft, and guided tissue regeneration. Fifty patients with a periodontal defect not associated with a furcation and with an attachment loss of at least 7.0 mm were included in this study. Full-thickness flaps were reflected, the roots were planed, EMD was applied, a demineralized freeze-dried bone allograft combined with EMD was placed, a bioabsorbable membrane was placed, and more EMD was applied. The defect areas were then sutured. At a mean of 5.3 months after treatment, there was a mean increase in recession of 0.7 mm, a mean reduction in probing depth of 5.7 mm, and a mean gain in attachment level of 5.0 mm. In this study there was more recession in smokers than in nonsmokers and in defects associated with anterior teeth. Additionally, the deeper defects (those with greater probing depths and attachment level loss) had the greatest reductions in probing depth and gains in attachment level. Based on this study, this technique proved itself to be an effective method to improve the clinical situation when treating periodontal defects not involving furcations.

  18. The use of enamel matrix derivative (Emdogain) for improvement of probing attachment level of the autotransplanted teeth.

    Science.gov (United States)

    Hamamoto, Yoshioki; Takahashi, Kouji; Sakurai, Hiromasa; Akiba, Katsumi; Izumi, Naoya; Kanoh, Hiroyuki; Yoshizawa, Michiko; Saito, Chikara

    2005-12-01

    The enamel matrix derivative (EMD, Emdogain) was used for the purpose to obtain the periodontal regeneration on the denuded root-surfaces of the donor teeth in two cases of the immediate tooth-transplantation. The root-surfaces at the cervical portion of the teeth were denuded because of extrusion. The healthy periodontium of each tooth remained at the apical portion of the roots. The denuded root-surfaces were cleansed before extraction. Then, the donor teeth were gently extracted with forceps, administered EMD, and transplanted so that the denuded surfaces were covered by gingival flaps. After the transplantation, the mean probing attachment level (PAL) improved 3.2 mm and 1.5 mm, respectively. The mean probing pocket depth was within normal level. The actual supporting areas of the roots of the transplanted teeth increased and the teeth worked as the abutments of prosthetic bridges.

  19. Effect of bone graft density on in vitro cell behavior with enamel matrix derivative.

    Science.gov (United States)

    Miron, Richard J; Caluseru, Oana M; Guillemette, Vincent; Zhang, Yufeng; Buser, Daniel; Chandad, Fatiha; Sculean, Anton

    2015-09-01

    Bone replacement grafting materials play an important role in regenerative dentistry. Despite a large array of tested bone-grafting materials, little information is available comparing the effects of bone graft density on in vitro cell behavior. Therefore, the aim of the present study is to compare the effects of cells seeded on bone grafts at low and high density in vitro for osteoblast adhesion, proliferation, and differentiation. The response of osteoblasts to the presence of a growth factor (enamel matrix derivative, (EMD)) in combination with low (8 mg per well) or high (100 mg per well) bone grafts (BG; natural bone mineral, Bio-Oss®) density, was studied and compared for osteoblast cell adhesion, proliferation, and differentiation as assessed by real-time PCR. Standard tissue culture plastic was used as a control with and without EMD. The present study demonstrates that in vitro testing of bone-grafting materials is largely influenced by bone graft seeding density. Osteoblast adhesion was up to 50 % lower when cells were seeded on high-density BG when compared to low-density BG and control tissue culture plastic. Furthermore, proliferation was affected in a similar manner whereby cell proliferation on high-density BG (100 mg/well) was significantly increased when compared to that on low-density BG (8 mg/well). In contrast, cell differentiation was significantly increased on high-density BG as assessed by real-time PCR for markers collagen 1 (Col 1), alkaline phosphatase (ALP), and osteocalcin (OC) as well as alizarin red staining. The effects of EMD on osteoblast adhesion, proliferation, and differentiation further demonstrated that the bone graft seeding density largely controls in vitro results. EMD significantly increased cell attachment only on high-density BG, whereas EMD was able to further stimulate cell proliferation and differentiation of osteoblasts on control culture plastic and low-density BG when compared to high-density BG. The results

  20. Enamel matrix derivative and periodontal tissue regeneration%釉基质蛋白衍生物治疗牙周组织再生进展的研究

    Institute of Scientific and Technical Information of China (English)

    吴飞俊

    2013-01-01

    Emdogain的主要成分是釉基质蛋白衍生物(enamel matrix derivative,EMD),是通过乙酸法、纯化层析法从猪恒牙胚提取获得.EMD不仅能促进无细胞性牙骨质再生,还能促进牙周膜细胞的增殖及分化,其用于牙周组织再生治疗已成为近年来牙周病领域研究的热点.文中就EMD促进牙周组织再生方面的研究及其口腔临床应用概况进行综述.%The main component of Emdogain is the enamel matrix derivative (EMD) extracted from porcine tooth buds by a— cidic extraction and purified by chromatography . EMD can not only induce the regeneration of acellular cement , but also promote the proliferation and differentiation of periodontal ligament cells . In recent years, researches on the role of EMD in periodontal tissue regen -eration have become a hot spot in periodontics . This article offers an overview on the recent studies on the effects of EMD in periodontal tissue regeneration and its application in clinical stomagology .

  1. Enamel matrix derivative (emdogain) or subepithelial connective tissue graft for the treatment of adjacent multiple gingival recessions: a pilot study.

    Science.gov (United States)

    Alkan, Eylem Ayhan; Parlar, Ates

    2013-01-01

    One treatment approach for achieving healing by regeneration is the application of enamel matrix derivative (EMD) during periodontal surgery. The aim of this randomized clinical study was to compare the efficacy of EMD with a connective tissue graft (CTG) for the treatment of adjacent Miller Class l and II multiple gingival recessions. Twelve systemically healthy subjects with at least two Miller Class I or II multiple gingival recession defects affecting adjacent teeth on both sides of the mouth were enrolled. The surgical protocol was performed for both groups. The 56 recession defects were evaluated for recession depth (RD), recession width (RW), percentage of root coverage (PRC), height of keratinized tissue (HKT), probing depth (PD), and clinical attachment level (CAL). All measurements were repeated at 6 and 12 months. The mean PRC at the final evaluation was 89% ± 17% for the coronally advanced flap (CAF) + EMD group and 93% ± 17% for the CAF + CTG group. Both treatments resulted in statistically significant decreases in RD and RW and increases in HKT at 6 and 12 months. There was also a significant CAL gain for both groups. PD remained shallow over time. The results demonstrated that both procedures were successful in treating Miller Class I and II multiple gingival recessions; however, the greater results of the CAF + CTG group did not reach a statistically significant level.

  2. Success Evaluation of Pulpotomy in Primary Molars with Enamel Matrix Derivative: a Pilot Study

    Directory of Open Access Journals (Sweden)

    Fatemeh Mazhari

    2016-06-01

    Full Text Available Aim: To investigate the effect of Emdogain gel (EMD in pulpotomized primary molars and its clinical and radiographic outcomes. Methods and Materials: In this   study, 18 lower second primary molars of nine children were treated by   pulpotomy. The teeth were randomly assigned to the EMD (experimental and Formocresol (control groups in each patient (split mouth. Following removal of the coronal pulp and haemostasis, the pulp stumps were covered with Emdogain gel in the experimental group followed by application of resin-modified glass ionomer cement over the gel. In the control group, Formocresol (FC was placed with a cotton pellet over the pulp stumps. Lastly, the teeth in both groups were restored with stainless steel crowns. Results: Nine children referred with clinical failure before/at two months follow up. The radiographic evaluation revealed furcation involvement and extensive radicular radiolucency in molars treated with Emdogain gel. Conclusion: The present study showed the failure of enamel matrix derivative in pulpotomy of primary molars; therefore, we do not recommend using Emdogain as a pulpotomy agent for treatment of cariously exposed primary teeth

  3. A survey on regenerative surgery performed by Swiss specialists in periodontology with special emphasis on the application of enamel matrix derivatives in infrabony defects.

    Science.gov (United States)

    Schröen, Ola; Sahrmann, Philipp; Roos, Malgorzata; Attin, Thomas; Schmidlin, Patrick R

    2011-01-01

    This survey aimed to evaluate the common practice of regenerative periodontal surgery with special regard to the use of enamel matrix derivatives (EMD, Emdogain® ) by board-certified specialists in periodontology and non-certified, but active members of the Swiss Society of Periodontology (SSP). A cross-sectional postal survey of 533 dentists, representing all members of the SSP practising in Switzerland, was conducted. The questionnaire consisted of three sections, assessing: 1) general personal information regarding the practice setting and education, 2) general questions regarding periodontal surgery practices and 3) specific questions regarding the use of EMD. The information obtained was compared and differences between specialists and non-specialists were calculated. P-values smaller than 5% were considered significant. Sixty-nine percent of the specialists answered the questionnaire, compared to only 37.4% of the non-specialists (overall: 42.4%). In general, specialists performed surgeries more frequently, and presented a significantly higher percentage of EMD users than the non-specialists. The application guidelines were followed in general. Some differences were observed in application and selection criteria. The subjective perception of clinical success varied greatly among clinicians. Residual pockets were reported to be present in approximately one third of the defects after therapy. In conclusion, this survey revealed that EMD was used on a regular basis by dentists performing periodontal therapy. In addition, the answers by both groups generally corresponded well with the current available literature.

  4. Clinical Outcomes after Treatment of Periodontal Intrabony Defects with Nanocrystalline Hydroxyapatite (Ostim or Enamel Matrix Derivatives (Emdogain: A Randomized Controlled Clinical Trial

    Directory of Open Access Journals (Sweden)

    Elyan Al Machot

    2014-01-01

    Full Text Available Introduction. Periodontitis is an inflammatory process in response to dental biofilm and leads to periodontal tissue destruction. The aim of this study was the comparison of outcomes using either an enamel matrix derivative (EMD or a nanocrystalline hydroxyapatite (NHA in regenerative periodontal therapy after 6 and 12 months. Methods. Using a parallel group, prospective randomized study design, we enrolled 19 patients in each group. The primary outcome was bone fill after 12 months. Attachment gain, probing pocket depth (PPD reduction, and recession were secondary variables. Additionally, early wound healing and adverse events were assessed. Data analysis included test of noninferiority of NHA group (test compared to EMD group (reference in bone fill. Differences in means of secondary variables were compared by paired t-test, frequency data by exact χ2 test. Results. Both groups showed significant bone fill, reduction of PPD, increase in recession, and gain of attachment after 6 and 12 months. No significant differences between groups were found at any time point. Adverse events were comparable between both groups with a tendency of more complaints in the NHA group. Conclusion. The clinical outcomes were similar in both groups. EMD could have some advantage compared to NHA regarding patients comfort and adverse events. The trial is registered with ClinicalTrials.gov NCT00757159.

  5. Addition of enamel matrix derivatives to bone substitutes for the treatment of intrabony defects: A systematic review, meta-analysis and trial sequential analysis.

    Science.gov (United States)

    Troiano, Giuseppe; Laino, Luigi; Zhurakivska, Khrystyna; Cicciù, Marco; Lo Muzio, Lorenzo; Lo Russo, Lucio

    2017-07-01

    In order to enhance clinical improvement of intrabony defects, the addition of enamel matrix derivatives (EMD) to bone substitues (BS) has been investigated. The aim of this systematic review is to figure out whether such a combination, in comparison to the treatment with BS alone has beneficial effects on the following outcomes: clinical attachment level (CAL) gain, probing depth (PD) reduction and recession (REC). Electronic databases (PUBMED, SCOPUS, EBSCO Host Research Databases and Web of Knowledge) were searched for randomized controlled trials in humans addressing the use of a combination of BS and EMD versus a control group with BS alone for the treatment of intrabony defects, with a minimum of 6 months of follow-up; meta-analysis and trial sequential analysis were then performed. From a total of 1,197 records screened by title and abstract, nine studies were read full-text and five out of them included in the meta-analysis. No significant differences have been demonstrated both for CAL gain, PD reduction and REC between test and control groups. In the treatment of intrabony defects, the addition of EMD to BS seems to be not beneficial in terms of CAL gain, PD reduction and REC changes. However, such results should be considered with caution because of the small number of studies included in the meta-analysis and their heterogeneity. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  6. Clinical and histologic evaluation of an enamel matrix derivative combined with a biphasic calcium phosphate for the treatment of human intrabony periodontal defects.

    Science.gov (United States)

    Sculean, Anton; Windisch, Péter; Szendröi-Kiss, Dóra; Horváth, Attila; Rosta, Péter; Becker, Jürgen; Gera, István; Schwarz, Frank

    2008-10-01

    The goal of this study was to evaluate clinically and histologically the healing of advanced intrabony defects following regenerative periodontal surgery with an enamel matrix derivative (EMD) combined with a new biphasic calcium phosphate (BCP). Ten subjects, each of them displaying advanced combined 1- and 2-wall intrabony defects around teeth scheduled for extraction because of advanced chronic periodontitis and further prosthodontic considerations, were included in the study. The defects were consecutively treated with a combination of EMD + BCP. A notch was placed at the most apical extent of the calculus present on the root surface or at the most apical part of the defect (if no calculus was present) to serve as a reference for the histologic evaluation. At 9 months after regenerative surgery, nine of 10 teeth were extracted with some of their surrounding soft and hard tissues and processed for histologic evaluation. There were no adverse effects related to EMD or the graft material used in any of the treated subjects. One tooth was not extracted because of the excellent clinical outcome. The clinical measurements at the nine biopsied teeth demonstrated a mean probing depth reduction of 3.3 +/- 1.4 mm and a mean clinical attachment level gain of 3.0 +/- 1.6 mm. The histologic findings indicated formation of cementum with inserting collagen fibers to a varying extent. A long junctional epithelium was observed in three of the nine biopsies. Mean new connective tissue attachment (i.e., new cementum with inserting collagen fibers) varied from 0.0 to 2.1 mm. The amount of newly formed bone was limited and varied from 0.0 to 0.7 mm. At 9 months, graft particles were still present and were mostly encapsulated in connective tissue, whereas formation of bone around the graft particles was observed only occasionally. Direct contact between the graft particles and the root surface (cementum or dentin) was not observed in any of the analyzed specimens. The combination of

  7. Enamel matrix proteins; old molecules for new applications.

    Science.gov (United States)

    Lyngstadaas, S P; Wohlfahrt, J C; Brookes, S J; Paine, M L; Snead, M L; Reseland, J E

    2009-08-01

    Emdogain (enamel matrix derivative, EMD) is well recognized in periodontology, where it is used as a local adjunct to periodontal surgery to stimulate regeneration of periodontal tissues lost to periodontal disease. The biological effect of EMD is through stimulation of local growth factor secretion and cytokine expression in the treated tissues, inducing a regenerative process that mimics odontogenesis. The major (>95%) component of EMD is Amelogenins (Amel). No other active components have so far been isolated from EMD, and several studies have shown that purified amelogenins can induce the same effect as the complete EMD. Amelogenins comprise a family of highly conserved extracellular matrix proteins derived from one gene. Amelogenin structure and function is evolutionary well conserved, suggesting a profound role in biomineralization and hard tissue formation. A special feature of amelogenins is that under physiological conditions the proteins self-assembles into nanospheres that constitute an extracellular matrix. In the body, this matrix is slowly digested by specific extracellular proteolytic enzymes (matrix metalloproteinase) in a controlled process, releasing bioactive peptides to the surrounding tissues for weeks after application. Based on clinical and experimental observations in periodontology indicating that amelogenins can have a significant positive influence on wound healing, bone formation and root resorption, several new applications for amelogenins have been suggested. New experiments now confirm that amelogenins have potential for being used also in the fields of endodontics, bone regeneration, implantology, traumatology, and wound care.

  8. [Treatment of localized intrabony periodontal defects with enamel matrix derivative (Emdogain). Case series].

    Science.gov (United States)

    Szatmári, Péter; Gera, István

    2014-03-01

    The solitary vertical or horisonto-vertical bone lesions are mainly characteristic of aggressive periodontitis. Only a combined conservative-surgical approach can result in predictable healing. From the early 50's basically two surgical techniques were used for correcting vertical bony defects. The so called bone resective techniques combined with apically positioned flap resulted in the flattening of the bone contour by removing substantial amount of alveolar bone but compromising the periodontal support of the neighboring teeth. The other surgical approach was the facilitation of the reformation of new periodontal attachment and bone with or without bone grafting. Since the mid 80's the gold standard in the therapy of deep vertical bony defects is the guided tissue regeneration (GTR), although an alternative approach has also been developed using different growth and differentiation factors promoting periodontal wound healing. Today in the clinical practices both in periodontal osseous and mucogingival surgeries the most widely used biological factor is the amelogenin and its commercially available product the Enamel Matrix Derivative (Emdogain). With the presented five solitary horisonto-vertical bony defects of three patients the possibilities and the late results are presented that could have been achieved with the application of EMD and thorough postoperative follow-up. The clinical results were comparable to the current data presented by articles in peer reviewed periodontal journals.

  9. Nanoscale Reinforced, Polymer Derived Ceramic Matrix Coatings

    Energy Technology Data Exchange (ETDEWEB)

    Rajendra Bordia

    2009-07-31

    The goal of this project was to explore and develop a novel class of nanoscale reinforced ceramic coatings for high temperature (600-1000 C) corrosion protection of metallic components in a coal-fired environment. It was focused on developing coatings that are easy to process and low cost. The approach was to use high-yield preceramic polymers loaded with nano-size fillers. The complex interplay of the particles in the polymer, their role in controlling shrinkage and phase evolution during thermal treatment, resulting densification and microstructural evolution, mechanical properties and effectiveness as corrosion protection coatings were investigated. Fe-and Ni-based alloys currently used in coal-fired environments do not possess the requisite corrosion and oxidation resistance for next generation of advanced power systems. One example of this is the power plants that use ultra supercritical steam as the working fluid. The increase in thermal efficiency of the plant and decrease in pollutant emissions are only possible by changing the properties of steam from supercritical to ultra supercritical. However, the conditions, 650 C and 34.5 MPa, are too severe and result in higher rate of corrosion due to higher metal temperatures. Coating the metallic components with ceramics that are resistant to corrosion, oxidation and erosion, is an economical and immediate solution to this problem. Good high temperature corrosion protection ceramic coatings for metallic structures must have a set of properties that are difficult to achieve using established processing techniques. The required properties include ease of coating complex shapes, low processing temperatures, thermal expansion match with metallic structures and good mechanical and chemical properties. Nanoscale reinforced composite coatings in which the matrix is derived from preceramic polymers have the potential to meet these requirements. The research was focused on developing suitable material systems and

  10. Porcine Collagen Matrix With And Without Enamel Matrix Derivative For The Treatment Of Gingival Recession Defects

    Science.gov (United States)

    2016-06-01

    Postgraduate Dental School Uniformed Services University of the Health Sciences In partial fulfillment of the requirements for the degree of Master of...receive CM+EMD (test), while the other will receive CM (control) alone . Methods The treatment of 30 similarly sized Miller class I, II or III recession...defects on single- rooted teeth using coronally advanced flaps with CM + EMD or CM alone will be evaluated. The subjects will be in good health, non

  11. Matrix summability of the conjugate deries of derived Fourier series

    Directory of Open Access Journals (Sweden)

    Shyam Lal

    2002-03-01

    Full Text Available In this paper, a new theorem on matrix summability of the conjugate series of a derived Fourier series is proved, which improves and generalizes all the previous known results in this line of work.

  12. Automatic generation of matrix element derivatives for tight binding models

    Science.gov (United States)

    Elena, Alin M.; Meister, Matthias

    2005-10-01

    Tight binding (TB) models are one approach to the quantum mechanical many-particle problem. An important role in TB models is played by hopping and overlap matrix elements between the orbitals on two atoms, which of course depend on the relative positions of the atoms involved. This dependence can be expressed with the help of Slater-Koster parameters, which are usually taken from tables. Recently, a way to generate these tables automatically was published. If TB approaches are applied to simulations of the dynamics of a system, also derivatives of matrix elements can appear. In this work we give general expressions for first and second derivatives of such matrix elements. Implemented in a tight binding computer program, like, for instance, DINAMO, they obviate the need to type all the required derivatives of all occurring matrix elements by hand.

  13. Antagonism of the anxiolytic action of diazepam and chlordiazepoxide by the novel imidazopyridines, EMD 39593 and EMD 41717.

    Science.gov (United States)

    Skolnick, P; Paul, S; Crawley, J; Lewin, E; Lippa, A; Clody, D; Irmscher, K; Saiko, O; Minck, K O

    1983-04-08

    The imidazopyridines EMD 35993 and EMD 41717 antagonized the anticonflict actions of diazepam and chlordiazepoxide in rodent models which are predictive for anxiolytic action in man. In contrast to other described benzodiazepine antagonists, these compounds did not antagonize either the anticonvulsant or muscle relaxant properties of either benzodiazepine. Both EMD 39593 and EMD 41717 competitively inhibit the binding of [3H]diazepam to brain membranes, but do not exhibit regional differences in potency. These observations suggest that both EMD 39593 and EMD 41717 display some selectivity in antagonizing the anxiolytic properties of benzodiazepines, and as such may be useful tools in identifying neuronal substrates of anxiety.

  14. The effect of enamel matrix proteins on the spreading, proliferation and differentiation of osteoblasts cultured on titanium surfaces.

    Science.gov (United States)

    Miron, Richard J; Oates, Christine J; Molenberg, Aart; Dard, Michel; Hamilton, Douglas W

    2010-01-01

    Modifications of implant surface topography and chemistry have proven a means to enhance osseointegration, a process that ensures the stability of bone-contacting devices, including titanium dental implants. The commercial product Emdogain is an enamel matrix derivative (EMD) extracted from porcine teeth commonly used in periodontal surgery, where it has been shown to potentiate regeneration of bone. The aim of the present study was to evaluate the effect of EMD on the attachment, proliferation and differentiation of osteoblasts on titanium surfaces in vitro. Pickled (smooth) and SLA (roughened) titanium discs were coated with EMD or left uncoated. Primary rat calvarial osteoblasts were cultured on each surface from 1h to 4 weeks. EMD significantly increased cell spreading and proliferation at time points ranging from 3 to 7 days on both topographies. Alkaline phosphatase activity was significantly increased on EMD-coated titanium compared with titanium alone. Moreover, there was a 6 fold increase in levels of mRNA encoding bone sialoprotein and osteocalcin in osteoblasts cultured on EMD-coated titanium surfaces compared with uncoated surfaces. We conclude that coating of titanium with EMD enhances the proliferation and differentiation of osteoblasts irrespective of the titanium substratum topography.

  15. Equivalence of the EMD- and NEMD-based decomposition of thermal conductivity into microscopic building blocks

    Science.gov (United States)

    Matsubara, Hiroki; Kikugawa, Gota; Ishikiriyama, Mamoru; Yamashita, Seiji; Ohara, Taku

    2017-09-01

    Thermal conductivity of a material can be comprehended as being composed of microscopic building blocks relevant to the energy transfer due to a specific microscopic process or structure. The building block is called the partial thermal conductivity (PTC). The concept of PTC is essential to evaluate the contributions of various molecular mechanisms to heat conduction and has been providing detailed knowledge of the contribution. The PTC can be evaluated by equilibrium molecular dynamics (EMD) and non-equilibrium molecular dynamics (NEMD) in different manners: the EMD evaluation utilizes the autocorrelation of spontaneous heat fluxes in an equilibrium state whereas the NEMD one is based on stationary heat fluxes in a non-equilibrium state. However, it has not been fully discussed whether the two methods give the same PTC or not. In the present study, we formulate a Green-Kubo relation, which is necessary for EMD to calculate the PTCs equivalent to those by NEMD. Unlike the existing theories, our formulation is based on the local equilibrium hypothesis to describe a clear connection between EMD and NEMD simulations. The equivalence of the two derivations of PTCs is confirmed by the numerical results for liquid methane and butane. The present establishment of the EMD-NEMD correspondence makes the MD analysis of PTCs a robust way to clarify the microscopic origins of thermal conductivity.

  16. Texture classification based on EMD and FFT

    Institute of Scientific and Technical Information of China (English)

    XIONG Chang-zhen; XU Jun-yi; ZOU Jian-cheng; QI Dong-xu

    2006-01-01

    Empirical mode decomposition (EMD) is an adaptive and approximately orthogonal filtering process that reflects human's visual mechanism of differentiating textures. In this paper, we present a modified 2D EMD algorithm using the FastRBF and an appropriate number of iterations in the shifting process (SP), then apply it to texture classification. Rotation-invariant texture feature vectors are extracted using auto-registration and circular regions of magnitude spectra of 2D fast Fourier transform(FFT). In the experiments, we employ a Bayesion classifier to classify a set of 15 distinct natural textures selected from the Brodatz album. The experimental results, based on different testing datasets for images with different orientations, show the effectiveness of the proposed classification scheme.

  17. Streptococcus mutans-derived extracellular matrix in cariogenic oral biofilms.

    Science.gov (United States)

    Klein, Marlise I; Hwang, Geelsu; Santos, Paulo H S; Campanella, Osvaldo H; Koo, Hyun

    2015-01-01

    Biofilms are highly structured microbial communities that are enmeshed in a self-produced extracellular matrix. Within the complex oral microbiome, Streptococcus mutans is a major producer of extracellular polymeric substances including exopolysaccharides (EPS), eDNA, and lipoteichoic acid (LTA). EPS produced by S. mutans-derived exoenzymes promote local accumulation of microbes on the teeth, while forming a spatially heterogeneous and diffusion-limiting matrix that protects embedded bacteria. The EPS-rich matrix provides mechanical stability/cohesiveness and facilitates the creation of highly acidic microenvironments, which are critical for the pathogenesis of dental caries. In parallel, S. mutans also releases eDNA and LTA, which can contribute with matrix development. eDNA enhances EPS (glucan) synthesis locally, increasing the adhesion of S. mutans to saliva-coated apatitic surfaces and the assembly of highly cohesive biofilms. eDNA and other extracellular substances, acting in concert with EPS, may impact the functional properties of the matrix and the virulence of cariogenic biofilms. Enhanced understanding about the assembly principles of the matrix may lead to efficacious approaches to control biofilm-related diseases.

  18. Streptococcus mutans-derived extracellular matrix in cariogenic oral biofilms

    Directory of Open Access Journals (Sweden)

    Marlise eKlein

    2015-02-01

    Full Text Available Biofilms are highly structured microbial communities that are enmeshed in a self-produced extracellular matrix. Within the complex oral microbiome, Streptococcus mutans is a major producer of extracellular polymeric substances including exopolysaccharides (EPS, eDNA and lipoteichoic acid (LTA. EPS produced by S. mutans-derived exoenzymes promote local accumulation of microbes on the teeth, while forming a spatially heterogeneous and diffusion-limiting matrix that protects embedded bacteria. The EPS-rich matrix provides mechanical stability/cohesiveness and facilitates the creation of highly acidic microenvironments, which are critical for the pathogenesis of dental caries. In parallel, S. mutans also releases eDNA and LTA, which can contribute with matrix development. eDNA enhances EPS (glucan synthesis locally, increasing the adhesion of S. mutans to saliva-coated apatitic surfaces and the assembly of highly cohesive biofilms. eDNA and other extracellular substances, acting in concert with EPS, may impact the functional properties of the matrix and the virulence of cariogenic biofilms. Enhanced understanding about the assembly principles of the matrix may lead to efficacious approaches to control biofilm-related diseases.

  19. Derivatives of eigenvalues and eigenvectors of a general complex matrix

    Science.gov (United States)

    Murthy, Durbha V.; Haftka, Raphael T.

    1988-01-01

    A survey of methods for sensitivity analysis of the algebraic eigenvalue problem for non-Hermitian matrices is presented. In addition, a modification of one method based on a better normalizing condition is proposed. Methods are classified as Direct or Adjoint and are evaluated for efficiency. Operation counts are presented in terms of matrix size, number of design variables and number of eigenvalues and eigenvectors of interest. The effect of the sparsity of the matrix and its derivatives is also considered, and typical solution times are given. General guidelines are established for the selection of the most efficient method.

  20. The novel ATP-competitive inhibitor of the MET hepatocyte growth factor receptor EMD1214063 displays inhibitory activity against selected MET-mutated variants.

    Science.gov (United States)

    Medová, Michaela; Pochon, Benoît; Streit, Bruno; Blank-Liss, Wieslawa; Francica, Paola; Stroka, Deborah; Keogh, Adrian; Aebersold, Daniel M; Blaukat, Andree; Bladt, Friedhelm; Zimmer, Yitzhak

    2013-11-01

    The receptor tyrosine kinase MET is a prime target in clinical oncology due to its aberrant activation and involvement in the pathogenesis of a broad spectrum of malignancies. Similar to other targeted kinases, primary and secondary mutations seem to represent an important resistance mechanism to MET inhibitors. Here, we report the biologic activity of a novel MET inhibitor, EMD1214063, on cells that ectopically express the mutated MET variants M1268T, Y1248H, H1112Y, L1213V, H1112L, V1110I, V1206L, and V1238I. Our results show a dose-dependent decrease in MET autophosphorylation in response to EMD1214063 in five of the eight cell lines (IC50 2-43 nmol/L). Blockade of MET by EMD1214063 was accompanied by a reduced activation of downstream effectors in cells expressing EMD1214063-sensitive mutants. In all sensitive mutant-expressing lines, EMD1214063 altered cell-cycle distribution, primarily with an increase in G1 phase. EMD1214063 strongly influenced MET-driven biologic functions, such as cellular morphology, MET-dependent cell motility, and anchorage-independent growth. To assess the in vivo efficacy of EMD1214063, we used a xenograft tumor model in immunocompromised mice bearing NIH3T3 cells expressing sensitive and resistant MET-mutated variants. Animals were randomized for the treatment with EMD1214063 (50 mg/kg/d) or vehicle only. Remarkably, five days of EMD1214063 treatment resulted in a complete regression of the sensitive H1112L-derived tumors, whereas tumor growth remained unaffected in mice with L1213V tumors and in vehicle-treated animals. Collectively, the current data identifies EMD1214063 as a potent MET small-molecule inhibitor with selective activity towards mutated MET variants. ©2013 AACR.

  1. Replacement of animal-derived collagen matrix by human fibroblast-derived dermal matrix for human skin equivalent products.

    Science.gov (United States)

    El Ghalbzouri, Abdoelwaheb; Commandeur, Suzan; Rietveld, Marion H; Mulder, Aat A; Willemze, Rein

    2009-01-01

    Reconstructed human skin equivalents (HSEs) are representative models of human skin and widely used for research purposes and clinical applications. Traditional methods to generate HSEs are based on the seeding of human keratinocytes onto three-dimensional human fibroblast-populated non-human collagen matrices. Current HSEs have a limited lifespan of approximately 8 weeks, rendering them unsuitable for long-term studies. Here we present a new generation of HSEs being fully composed of human components and which can be cultured up to 20 weeks. This model is generated on a primary human fibroblast-derived dermal matrix. Pro-collagen type I secretion by human fibroblasts stabilized during long-term culture, providing a continuous and functional human dermal matrix. In contrast to rat-tail collagen-based HSEs, the present fibroblast-derived matrix-based HSEs contain more continuity in the number of viable cell layers in long-term cultures. In addition, these new skin models exhibit normal differentiation and proliferation, based on expression of K10/K15, and K16/K17, respectively. Detection of collagen types IV and VII and laminin 332 was confined to the epidermal-dermal junction, as in native skin. The presence of hemidesmosomes and anchoring fibrils was demonstrated by electron microscopy. Finally, we show that the presented HSE contained a higher concentration of the normal moisturizing factor compared to rat-tail collagen-based skin models, providing a further representation of functional normal human skin in vitro. This study, therefore, demonstrates the role of the dermal microenvironment on epidermal regeneration and lifespan in vitro.

  2. Premature osteoblast clustering by enamel matrix proteins induces osteoblast differentiation through up-regulation of connexin 43 and N-cadherin.

    Directory of Open Access Journals (Sweden)

    Richard J Miron

    Full Text Available In recent years, enamel matrix derivative (EMD has garnered much interest in the dental field for its apparent bioactivity that stimulates regeneration of periodontal tissues including periodontal ligament, cementum and alveolar bone. Despite its widespread use, the underlying cellular mechanisms remain unclear and an understanding of its biological interactions could identify new strategies for tissue engineering. Previous in vitro research has demonstrated that EMD promotes premature osteoblast clustering at early time points. The aim of the present study was to evaluate the influence of cell clustering on vital osteoblast cell-cell communication and adhesion molecules, connexin 43 (cx43 and N-cadherin (N-cad as assessed by immunofluorescence imaging, real-time PCR and Western blot analysis. In addition, differentiation markers of osteoblasts were quantified using alkaline phosphatase, osteocalcin and von Kossa staining. EMD significantly increased the expression of connexin 43 and N-cadherin at early time points ranging from 2 to 5 days. Protein expression was localized to cell membranes when compared to control groups. Alkaline phosphatase activity was also significantly increased on EMD-coated samples at 3, 5 and 7 days post seeding. Interestingly, higher activity was localized to cell cluster regions. There was a 3 fold increase in osteocalcin and bone sialoprotein mRNA levels for osteoblasts cultured on EMD-coated culture dishes. Moreover, EMD significantly increased extracellular mineral deposition in cell clusters as assessed through von Kossa staining at 5, 7, 10 and 14 days post seeding. We conclude that EMD up-regulates the expression of vital osteoblast cell-cell communication and adhesion molecules, which enhances the differentiation and mineralization activity of osteoblasts. These findings provide further support for the clinical evidence that EMD increases the speed and quality of new bone formation in vivo.

  3. Tailoring material properties of a nanofibrous extracellular matrix derived hydrogel

    Science.gov (United States)

    Johnson, Todd D.; Lin, Stephen Y.; Christman, Karen L.

    2011-12-01

    In the native tissue, the interaction between cells and the extracellular matrix (ECM) is essential for cell migration, proliferation, differentiation, mechanical stability, and signaling. It has been shown that decellularized ECMs can be processed into injectable formulations, thereby allowing for minimally invasive delivery. Upon injection and increase in temperature, these materials self-assemble into porous gels forming a complex network of fibers with nanoscale structure. In this study we aimed to examine and tailor the material properties of a self-assembling ECM hydrogel derived from porcine myocardial tissue, which was developed as a tissue specific injectable scaffold for cardiac tissue engineering. The impact of gelation parameters on ECM hydrogels has not previously been explored. We examined how modulating pH, temperature, ionic strength, and concentration affected the nanoscale architecture, mechanical properties, and gelation kinetics. These material characteristics were assessed using scanning electron microscopy, rheometry, and spectrophotometry, respectively. Since the main component of the myocardial matrix is collagen, many similarities between the ECM hydrogel and collagen gels were observed in terms of the nanofibrous structure and modulation of properties by altering ionic strength. However, variation from collagen gels was noted for the gelation temperature along with varied times and rates of gelation. These discrepancies when compared to collagen are likely due to the presence of other ECM components in the decellularized ECM based hydrogel. These results demonstrate how the material properties of ECM hydrogels could be tailored for future in vitro and in vivo applications.

  4. Randomized Placebo-Controlled and Controlled Non-Inferiority Phase III Trials Comparing Trafermin, a Recombinant Human Fibroblast Growth Factor 2, and Enamel Matrix Derivative in Periodontal Regeneration in Intrabony Defects.

    Science.gov (United States)

    Kitamura, Masahiro; Akamatsu, Motoki; Kawanami, Masamitsu; Furuichi, Yasushi; Fujii, Takeo; Mori, Mari; Kunimatsu, Kazushi; Shimauchi, Hidetoshi; Ogata, Yorimasa; Yamamoto, Matsuo; Nakagawa, Taneaki; Sato, Shuichi; Ito, Koichi; Ogasawara, Takefumi; Izumi, Yuichi; Gomi, Kazuhiro; Yamazaki, Kazuhisa; Yoshie, Hiromasa; Fukuda, Mitsuo; Noguchi, Toshihide; Takashiba, Shogo; Kurihara, Hidemi; Nagata, Toshihiko; Hamachi, Takafumi; Maeda, Katsumasa; Yokota, Makoto; Sakagami, Ryuji; Hara, Yoshitaka; Noguchi, Kazuyuki; Furuuchi, Toshi; Sasano, Takashi; Imai, Enyu; Ohmae, Masatoshi; Koizumi, Hayuru; Watanuki, Mitsuru; Murakami, Shinya

    2016-04-01

    We investigated the efficacy, safety, and clinical significance of trafermin, a recombinant human fibroblast growth factor (rhFGF)-2, for periodontal regeneration in intrabony defects in Phase III trials. Study A, a multicenter, randomized, double-blind, placebo-controlled study, was conducted at 24 centers. Patients with periodontitis with 4-mm and 3-mm or deeper probing pocket depth and intrabony defects, respectively, were included. A total of 328 patients were randomly assigned (2:1) to receive 0.3% rhFGF-2 or placebo, and 323 patients received the assigned investigational drug during flap surgery. One of the co-primary endpoints, the percentage of bone fill at 36 weeks after drug administration, was significantly greater in the rhFGF-2 group at 37.131% (95% confidence interval [CI], 32.7502 to 41.5123; n = 208) than it was in the placebo group at 21.579% (95% CI, 16.3571 to 26.8011; n = 100; p < 0.001). The other endpoint, the clinical attachment level regained at 36 weeks, was not significantly different between groups. Study B, a multicenter, randomized, blinded (patients and evaluators of radiographs), and active-controlled study was conducted at 15 centers to clarify the clinical significance of rhFGF-2. Patients with 6-mm and 4-mm or deeper probing pocket depth and intrabony defects, respectively, were included. A total of 274 patients were randomly assigned (5:5:2) to receive rhFGF-2, enamel matrix derivative (EMD), or flap surgery alone. A total of 267 patients received the assigned treatment during flap surgery. The primary endpoint, the linear alveolar bone growth at 36 weeks, was 1.927 mm (95% CI, 1.6615 to 2.1920; n = 108) in the rhFGF-2 group and 1.359 mm (95% CI, 1.0683 to 1.6495; n = 109) in the EMD group, showing non-inferiority (a prespecified margin of 0.3 mm) and superiority of rhFGF-2 to EMD. Safety problems were not identified in either study. Therefore, trafermin is an effective and safe treatment for periodontal regeneration in intrabony

  5. Dynamic unbalance detection of cardan shaft in high-speed train based on EMD-SVD-NHT

    Institute of Scientific and Technical Information of China (English)

    丁建明; 林建辉; 何刘; 赵洁

    2015-01-01

    Contrary to the aliasing defect between the adjacent intrinsic model functions (IMFs) existing in empirical model decomposition (EMD), a new method of detecting dynamic unbalance with cardan shaft in high-speed train was proposed by applying the combination between EMD, Hankel matrix, singular value decomposition (SVD) and normalized Hilbert transform (NHT). The vibration signals of gimbal installed base were decomposed through EMD to get different IMFs. The Hankel matrix constructed through the single IMF was orthogonally executed through SVD. The critical singular values were selected to reconstruct vibration signs on the basis of the key stack of singular values. Instantaneous frequencys (IFs) of reconstructed vibration signs were applied to detect dynamic unbalance with shaft and eliminated clutter spectrum caused by the aliasing defect between the adjacent IMFs, which highlighted the failure characteristics. The method was verified by test data in the unbalance condition of dynamic cardan shaft. The results show that the method effectively detects the fault vibration characteristics caused by cardan shaft dynamic unbalance and extracts the nature vibration features. With comparison to the traditional EMD-NHT, clarity and failure characterization force are significantly improved.

  6. EMD Method Applied to Identification of Logging Sequence Strata

    Directory of Open Access Journals (Sweden)

    Zhao Ni

    2015-10-01

    Full Text Available In this work, we compare Fourier transform, wavelet transform, and empirical mode decomposition (EMD, and point out that EMD method decomposes complex signal into a series of component functions through curves of local mean value. Each of Intrinsic Mode Functions (IMFs - component functions contains all the information on the original signal. Therefore, it is more suitable for the interface identification of logging sequence strata.

  7. The effect of enamel matrix proteins and deproteinized bovine bone mineral on heterotopic bone formation.

    Science.gov (United States)

    Donos, Nikolaos; Kostopoulos, Lambros; Tonetti, Maurizio; Karring, Thorkild; Lang, Niklaus P

    2006-08-01

    To evaluate the osteoinductive potential of deproteinized bovine bone mineral (DBBM) and an enamel matrix derivative (EMD) in the muscle of rats. Sixteen rats were used in this study. The animals were divided in three groups. Group A: a pouch was created in one of the pectoralis profundis muscles of the thorax of the rats and DBBM particles (Bio-Oss) were placed into the pouch. Healing: 60 days. Group B: a small pouch was created on both pectoralis profundis muscles at each side of the thorax midline. In one side, a mixture of EMD (Emdogain) mixed with DBBM was placed into one of the pouches, whereas in the contralateral side of the thorax the pouch was implanted with DBBM mixed with the propylene glycol alginate (PGA--carrier for enamel matrix proteins of EMD). Healing: 60 days. Group C: the same procedure as group B, but with a healing period of 120 days. Qualitative histological analysis of the results was performed. At 60 days, the histological appearance of the DBBM particles implanted alone was similar to that of the particles implanted together with EMD or PGA at both 60 and 120 days. The DBBM particles were encapsulated into a connective tissue stroma and an inflammatory infiltrate. At 120 days, the DBBM particles implanted together with EMD or PGA exhibited the presence of resorption lacunae in some cases. Intramuscular bone formation was not encountered in any group. The implantation of DBBM particles alone, combined with EMD or its carrier (PGA) failed to exhibit extraskeletal, bone-inductive properties.

  8. Density matrix of two interacting particles with kinetic coupling derived in bipartite entangled state representation

    Institute of Scientific and Technical Information of China (English)

    Guo Qin

    2007-01-01

    A density matrix is usually obtained by solving the Bloch equation, however only a few Hamiltonians' density matrices can be analytically derived. The density matrix for two interacting particles with kinetic coupling is hard to derive by the usual method due to this coupling; this paper solves this problem by using the bipartite entangled state representation.

  9. The Role of Host-derived Dentinal Matrix Metalloproteinases in Reducing Dentin Bonding of Resin Adhesives

    OpenAIRE

    Zhang, Shan-chuan; Kern, Matthias

    2009-01-01

    Dentin matrix metalloproteinases (MMPs) are a family of host-derived proteolytic enzymes trapped within mineralized dentin matrix, which have the ability to hydrolyze the organic matrix of demineralized dentin. After bonding with resins to dentin there are usually some exposed collagen fibrils at the bottom of the hybrid layer owing to imperfect resin impregnation of the demineralized dentin matrix. Exposed collagen fibrils might be affected by MMPs inducing hydrolytic degradation, which migh...

  10. Enamel matrix derivative promote primary human pulp cell differentiation and mineralization

    National Research Council Canada - National Science Library

    Riksen, Elisabeth Aurstad; Landin, Maria A; Reppe, Sjur; Nakamura, Yukio; Lyngstadaas, Ståle Petter; Reseland, Janne E

    2014-01-01

    ...; however the molecular mechanisms involved are unclear. The effect of EMD (5-50 μg/mL) on primary human pulp cells were compared to untreated cells and cells incubated with 10⁻⁸ M dexamethasone (DEX...

  11. Factors Involved in Extracellular Matrix Turnover in Human Derived Cardiomyocytes

    Directory of Open Access Journals (Sweden)

    Gregori Casals

    2013-11-01

    Full Text Available Background: The molecular mechanisms by which myocardial ischemia translates into ventricular remodeling remain unclear. Methods: We investigated whether hypoxia and proinflammatory cytokines are specific inducers of remodeling signals in an in vitro model of cultured adult human ventricular myocytes (AC16 cells. Results:Hypoxia modified the ratio of matrix remodeling factors by increasing the aminoterminal propeptide of type III procollagen (PIIINP and reducing tissue inhibitor of matrix metalloproteinase type 1 (TIMP-1 secretion in AC16 cells. These effects, however, were not associated with either modifications in expression of matrix metalloproteinase type 2, collagen-I or metalloproteinase activity. Hypoxia does, actually increase the production of the cardiac antifibrogenic growth factors, Apelin and VEGF, through an Hypoxia Inducible Factor type 1-dependent mechanism. Concerning proinflammatory signaling pathways, IL1β emerged as a powerful inducer of matrix turnover, since it significantly enhanced PIIINP, TIMP-1 and hyaluronic acid production and increased metalloproteinase activity. In contrast, TNFα did not modify matrix turnover but markedly induced the production of Apelin and VEGF. Conclusion: Hypoxia and increased TNFα activity likely exert cardioprotective actions by activating the cardiac antifibrogenic factors Apelin and VEGF. In contrast, IL1β is a strong promoter of interstitial collagen remodeling that may contribute to ventricular dilation and heart failure in the ischemic myocardium.

  12. Ultrasonic flaw detection using EMD-based signal processing

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The precise detection of flaw echoes buried in backscattering noise caused by material microstructure is a problem of great importance in ultrasonic non-destructive testing (NDT). In this work, empirical mode decomposition (EMD) is proposed to deal with ultrasonic signal. A time-frequency filtering method based on EMD is designed to suppress noise and enhance flaw signals. Simulated results are presented,showing that the proposed method has an excellent performance even for a very low signal-to-noise ratio(SNR). The improvement in flaw detection was experimentally verified using stainless steel pipe sample with artificial flaws.

  13. Derivation of R-matrix from local Hamiltonian density

    CERN Document Server

    Bibikov, P N

    2000-01-01

    A computer algebra algoritm for solving the quantum Yang-Baxter equation is presented. It is based on the Taylor expansion of R-matrix which is developed up to the order \\lambda^6. As an example the classification of 4x4 R-matrices is given.

  14. The publication-citation matrix and its derived quantities

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    We give an overview of the main data of a publication-citation matrix. We show how impact factors are defined,and,in particular,point out the difference between the synchronous and the diachronous impact factor. The advantages and disadvantages of using both as tools in re-search evaluation are discussed.

  15. Derivatives of eigenvalues and eigenvectors for a general matrix

    Science.gov (United States)

    Rudisill, C. S.

    1974-01-01

    Expressions are obtained for the derivatives of the eigenvalues and eigenvectors which are expressions of only one left-hand and one right-hand eigenvector. The approach described makes use of a Choleski decomposition or some other decomposition method. The method may be extended to find any order of derivative of the eigenvalue and eigenvector. The expressions obtained for finding the derivatives of eigenvalues and eigenvectors for nonself-adjoint systems may be applied to self-adjoint systems.

  16. Derivation of stiffness matrix in constitutive modeling of magnetorheological elastomer

    Science.gov (United States)

    Leng, D.; Sun, L.; Sun, J.; Lin, Y.

    2013-02-01

    Magnetorheological elastomers (MREs) are a class of smart materials whose mechanical properties change instantly by the application of a magnetic field. Based on the specially orthotropic, transversely isotropic stress-strain relationships and effective permeability model, the stiffness matrix of constitutive equations for deformable chain-like MRE is considered. To valid the components of shear modulus in this stiffness matrix, the magnetic-structural simulations with finite element method (FEM) are presented. An acceptable agreement is illustrated between analytical equations and numerical simulations. For the specified magnetic field, sphere particle radius, distance between adjacent particles in chains and volume fractions of ferrous particles, this constitutive equation is effective to engineering application to estimate the elastic behaviour of chain-like MRE in an external magnetic field.

  17. EMD-based GPS baseline solution and validation test

    Institute of Scientific and Technical Information of China (English)

    WANG Jian; GAO Jing-xiang; WANG Jin-ling; XU Chang-hui

    2008-01-01

    A GPS baseline solution model is presented, based on the Empirical Mode Decomposition (EMD), which has the advantage of eliminating the error effects outside the model. The EMD technique is a new signal processing method for non-linear time series, which decomposes a time series into a finite and often small number of Intrinsic Mode Functions (IMFs). The decomposition procedure is adaptive and data-driven which is suitable for non-linear data series analysis. A multi-scale decomposition and reconstruction architecture is defined on the basis of the EMD theory and the error mitigation model is demonstrated as well. A standard of the scale selection for the elimination of errors, outside the model, was given in terms of the mean of the accumulated standardized modes. Thereafter, the scheme of the GPS baseline solution based on the EMD is suggested. The float solution residuals of the Double-Difference (DD) observation equation are used to extract the errors outside the model applied to modify the GPS DD measurements. Then the float solution was given again and the fixed solution was obtained by a Lambda algorithm. Three schemes are designed to test the proposed model and the experimental results show that the proposed model dramatically improves the relia- bility of ambiguity resolution after the elimination of errors outside the model.

  18. A matrix model for the topological string I: Deriving the matrix model

    CERN Document Server

    Eynard, Bertrand; Marchal, Olivier

    2010-01-01

    We construct a matrix model that reproduces the topological string partition function on arbitrary toric Calabi-Yau 3-folds. This demonstrates, in accord with the BKMP "remodeling the B-model" conjecture, that Gromov-Witten invariants of any toric Calabi-Yau 3-fold can be computed in terms of the spectral invariants of a spectral curve. Moreover, it proves that the generating function of Gromov-Witten invariants is a tau-function for an integrable hierarchy. In a follow-up paper, we will explicitly construct the spectral curve of our matrix model and argue that it equals the mirror curve of the toric Calabi-Yau manifold.

  19. Derivation of the state matrix for dynamic analysis of linear homogeneous media.

    Science.gov (United States)

    Parra Martinez, Juan Pablo; Dazel, Olivier; Göransson, Peter; Cuenca, Jacques

    2016-08-01

    A method to obtain the state matrix of an arbitrary linear homogeneous medium excited by a plane wave is proposed. The approach is based on projections on the eigenspace of the governing equations matrix. It is an alternative to manually obtaining a linearly independent set of equations by combining the governing equations. The resulting matrix has been validated against previously published derivations for an anisotropic poroelastic medium.

  20. Uso de proteínas derivadas de la matriz del esmalte en defectos infraóseos periodontales: Presentación de casos clínicos Use of proteins enamel matrix derivative in infrabony periodontal defects: Presentación de casos clínicos

    Directory of Open Access Journals (Sweden)

    Alonso A

    2006-04-01

    Full Text Available La periodontitis es una infección crónica causada por las bacterias de la placa dental. Esta condición induce la perdida de soporte del aparato de inserción. La cirugía está indicada para detener la progresión de la enfermedad y regenerar el tejido perdido. Se han utilizado diferentes técnicas quirúrgicas para regenerar los tejidos periodontales incluyendo la regeneración tisular guiada (RTG, y el uso de proteínas derivadas de la matriz del esmalte (EMD. Las EMD contienen amelogenina. Se sabe que la amelogenina está relacionada con la formación del esmalte, y también con la formación de la inserción periodontal durante la formación dentaria. A través de esta presentación de dos casos clínicos tratados con Proteínas derivadas de matriz de esmalte EMDOGAIN®, se pretende , por un lado describir paso a paso el procedimiento clínico de su uso y a la vez hacer una revisión de la literatura de la regeneración periodontal y de la regeneración utilizando Emdogain® en particular.Periodontitis is a chronic infective disease of the gums caused by bacteria present in dental plaque. This condition induces the breakdown of the tooth supporting apparatus until teeth are lost. Surgery may be indicated to arrest disease progression and regenerate lost tissues. Several surgical techniques have been developed to regenerate periodontal tissues including guided tissue regeneration (GTR, and the use of proteins enamel matrix derivative (EMD. EMD is an extract of enamel matrix and contains amelogenins. There is evidence to show that amelogenins are involved not only in enamel formation, but also in the formation of the periodontal attachment during tooth formation. Accordly to two clinicals cases treated with Endogain, the aim of this presentation is, first to describe the clinical procedure,and second to make a literature review of the differents materials to periodontal regeneration.

  1. Combination of Collagen Barrier Membrane with Enamel Matrix Derivative-Liquid Improves Osteoblast Adhesion and Differentiation.

    Science.gov (United States)

    Miron, Richard J; Fujioka-Kobayashi, Masako; Buser, Daniel; Zhang, Yufeng; Bosshardt, Dieter D; Sculean, Anton

    Collagen barrier membranes were first introduced to regenerative periodontal and oral surgery to prevent fast ingrowing soft tissues (ie, epithelium and connective tissue) into the defect space. More recent attempts have aimed at combining collagen membranes with various biologics/growth factors to speed up the healing process and improve the quality of regenerated tissues. Recently, a new formulation of enamel matrix derivative in a liquid carrier system (Osteogain) has demonstrated improved physico-chemical properties for the adsorption of enamel matrix derivative to facilitate protein adsorption to biomaterials. The aim of this pioneering study was to investigate the use of enamel matrix derivative in a liquid carrier system in combination with collagen barrier membranes for its ability to promote osteoblast cell behavior in vitro. Undifferentiated mouse ST2 stromal bone marrow cells were seeded onto porcine-derived collagen membranes alone (control) or porcine membranes + enamel matrix derivative in a liquid carrier system. Control and enamel matrix derivative-coated membranes were compared for cell recruitment and cell adhesion at 8 hours; cell proliferation at 1, 3, and 5 days; and real-time polymerase chain reaction (PCR) at 3 and 14 days for genes encoding Runx2, collagen1alpha2, alkaline phosphatase, and bone sialoprotein. Furthermore, alizarin red staining was used to investigate mineralization. A significant increase in cell adhesion was observed at 8 hours for barrier membranes coated with enamel matrix derivative in a liquid carrier system, whereas no significant difference could be observed for cell proliferation or cell recruitment. Enamel matrix derivative in a liquid carrier system significantly increased alkaline phosphatase mRNA levels 2.5-fold and collagen1alpha2 levels 1.7-fold at 3 days, as well as bone sialoprotein levels twofold at 14 days postseeding. Furthermore, collagen membranes coated with enamel matrix derivative in a liquid carrier

  2. Spine fusion using cell matrix composites enriched in bone marrow-derived cells.

    Science.gov (United States)

    Muschler, George F; Nitto, Hironori; Matsukura, Yoichi; Boehm, Cynthia; Valdevit, Antonio; Kambic, Helen; Davros, William; Powell, Kimerly; Easley, Kirk

    2003-02-01

    Bone marrow-derived cells including osteoblastic progenitors can be concentrated rapidly from bone marrow aspirates using the surface of selected implantable matrices for selective cell attachment. Concentration of cells in this way to produce an enriched cellular composite graft improves graft efficacy. The current study was designed to test the hypothesis that the biologic milieu of a bone marrow clot will significantly improve the efficacy of such a graft. An established posterior spinal fusion model and cancellous bone matrix was used to compare an enriched cellular composite bone graft alone, bone matrix plus bone marrow clot, and an enriched bone matrix composite graft plus bone marrow clot. Union score, quantitative computed tomography, and mechanical testing were used to define outcome. The union score for the enriched bone matrix plus bone marrow clot composite was superior to the enriched bone matrix alone and the bone matrix plus bone marrow clot. The enriched bone matrix plus bone marrow clot composite also was superior to the enriched bone matrix alone in fusion volume and in fusion area. These data confirm that the addition of a bone marrow clot to an enriched cell-matrix composite graft results in significant improvement in graft performance. Enriched composite grafts prepared using this strategy provide a rapid, simple, safe, and inexpensive method for intraoperative concentration and delivery of bone marrow-derived cells and connective tissue progenitors that may improve the outcome of bone grafting.

  3. Hyperscaling Violating Solutions in Generalised EMD Theory

    CERN Document Server

    Li, Li

    2016-01-01

    This short note is devoted to deriving scaling but hyperscaling violating solutions in a generalised Einstein-Maxwell-Dilaton theory with an arbitrary number of scalars and vectors. We obtain analytic solutions in some special case and discuss the physical constraints on the allowed parameter range in order to have a well-defined holographic ground-state solution.

  4. RESEARCH ON THEORETIC EVIDENCE AND REALIZATION OF DIRECTLY-MEAN EMD METHOD

    Institute of Scientific and Technical Information of China (English)

    Zhong Youming; Qin Shuren; Tang Baoping

    2004-01-01

    Emprical mode decomposition(EMD) is a method and principle of decomposing signal dealing with Hilbert-Huang transform (HHT) in signal analysis, while directly-mean EMD is an improved EMD method presented by N.E.Huang, the inventor of HHT, which is aimed at solving the problems of EMD principle. Although the directly-mean EMD method is very remarkable with its advantages and N. E. Huang has given a method to realize it, he did not find the theoretic evidence of the method so that the feasibility of the idea and correctness of realizing the directly-mean EMD method is still indeterminate. For this a deep research on the forming process of complex signal is made and the involved stationary point principle and asymptotic stationary point principle are demonstrated, thus some theoretic evidences and the correct realizing way of directly-mean EMD method is firstly presented. Some simulation examples for demonstrating the idea presented are given.

  5. Cell-derived matrix coatings for polymeric scaffolds.

    Science.gov (United States)

    Decaris, Martin L; Binder, Bernard Y; Soicher, Matthew A; Bhat, Archana; Leach, J Kent

    2012-10-01

    Cells in culture deposit a complex extracellular matrix that remains intact following decellularization and possesses the capacity to modulate cell phenotype. The direct application of such decellularized matrices (DMs) to 3D substrates is problematic, as transport issues influence the homogeneous deposition, decellularization, and modification of DM surface coatings. In an attempt to address this shortcoming, we hypothesized that DMs deposited by human mesenchymal stem cells (MSCs) could be transferred to the surface of polymeric scaffolds while maintaining their capacity to direct cell fate. The ability of the transferred DM (tDM)-coated scaffolds to enhance the osteogenic differentiation of undifferentiated and osteogenically induced MSCs under osteogenic conditions in vitro was confirmed. tDM-coated scaffolds increased MSC expression of osteogenic marker genes (BGLAP, IBSP) and intracellular alkaline phosphatase production. In addition, undifferentiated MSCs deposited significantly more calcium when seeded onto tDM-coated scaffolds compared with control scaffolds. MSC-seeded tDM-coated scaffolds subcutaneously implanted in nude rats displayed significantly higher blood vessel density after 2 weeks compared with cells on uncoated scaffolds, but we did not observe significant differences in mineral deposition after 8 weeks. These data demonstrate that DM-coatings produced in 2D culture can be successfully transferred to 3D substrates and retain their capacity to modulate cell phenotype.

  6. Directional EMD and its application to texture segmentation

    Institute of Scientific and Technical Information of China (English)

    LIU Zhongxuan; PENG Silong

    2005-01-01

    In this paper we present the definition and framework of Directional Empirical Mode Decomposition (DEMD) and use DEMD to do texture segmentation. As a new technique of time-frequency analysis, EMD decomposes signals by sifting and then analyzes the instantaneous frequency of the obtained components called Intrinsic Mode Functions (IMFs). Compared with Bidimensional EMD (BEMD) which only extracts textures by radial basis function interpolation, the virtues of DEMD include: the directional quality is considered in this framework; four features can be extracted for each point from the decomposition. The technique of selecting directions for DEMD based on texture's Wold theory is also presented. Experimental results indicate the effectiveness of the method for texture segmentation. In addition, we show the explanation for the DEMD's ability for texture classification from visual views.

  7. Cross-correlation analysis of stock markets using EMD and EEMD

    Science.gov (United States)

    Xu, Mengjia; Shang, Pengjian; Lin, Aijing

    2016-01-01

    Empirical mode decomposition (EMD) is a data-driven signal analysis method for nonlinear and nonstationary data. Since it is intuitive, direct, posterior and adaptive, EMD is widely applied to various fields of study. In this paper, EMD and ensemble empirical mode decomposition (EEMD), a modified method of EMD, are applied to financial time series. Through analyzing the intrinsic mode functions (IMFs) of EMD and EEMD, we find EEMD method performs better on the orthogonality of IMFs than EMD. With clustering the ordered frequencies of IMFs, the IMFs obtained from EEMD method are grouped into high-, medium-, and low-frequency components, representing the short-, medium-, and long-term volatilities of the index sequences, respectively. With the cross-correlation analysis of DCCA cross-correlation coefficient, our findings allow us to gain further and detailed insight into the cross-correlations of stock markets.

  8. The role of host-derived dentinal matrix metalloproteinases in reducing dentin bonding of resin adhesives.

    Science.gov (United States)

    Zhang, Shan-chuan; Kern, Matthias

    2009-12-01

    Dentin matrix metalloproteinases (MMPs) are a family of host-derived proteolytic enzymes trapped within mineralized dentin matrix, which have the ability to hydrolyze the organic matrix of demineralized dentin. After bonding with resins to dentin there are usually some exposed collagen fibrils at the bottom of the hybrid layer owing to imperfect resin impregnation of the demineralized dentin matrix. Exposed collagen fibrils might be affected by MMPs inducing hydrolytic degradation, which might result in reduced bond strength. Most MMPs are synthesized and released from odontoblasts in the form of proenzymes, requiring activation to degrade extracellular matrix components. Unfortunately, they can be activated by modem self-etch and etch-and-rinse adhesives. The aim of this review is to summarize the current knowledge of the role of dentinal host-derived MMPs in dentin matrix degradation. We also discuss various available MMP inhibitors, especially chlorhexidine, and suggest that they could provide a potential pathway for inhibiting collagen degradation in bonding interfaces thereby increasing dentin bonding durability.

  9. Yang-Mills matrix models with ghosts and derivations of the graded shuffle algebra

    CERN Document Server

    Krishnaswami, Govind S

    2007-01-01

    We consider large-N multi-matrix models that are inspired by the action of Yang-Mills theory including gauge-fixing and ghost terms. We show that the factorized Schwinger-Dyson loop equations of such matrix models have a special algebraic property not shared by generic matrix models. When expressed in terms of the generating series of gluon and ghost correlations G(xi), they are quadratic equations S^i G = G xi^i G in concatenation of correlations. We express S^i in terms of the left annihilation operator and show that it is a derivation of the graded-shuffle product of correlation tensors. A corresponding property of Yang-Mills theory was observed by Makeenko and Migdal in the Wilson loop formulation, where S^i was expressed in terms of the path and area derivatives.

  10. Derivation of many-body potential among charged particles in the S-matrix method

    Science.gov (United States)

    Ohta, Tadayuki; Kimura, Toshiei

    1992-06-01

    A general method of deriving a classical potential from the S-matrix element of particle scattering in the theory of quantized fields is applied to electrodynamics to the post-post-Coulombian approximation. To obtain the many-body potential, a consistent prescription is implemented in subtracting the contributions of the repetition of lower-order potential from the S-matrix elements of the higher-order diagrams. The result shows that the four-body potential between charged particles has a characteristic feature at a large distance and the two-body potential is identical with that given in the reduced Hamiltonian of Wheeler-Feynman electrodynamics. The advantage of the S-matrix method over the canonical formalism is to give the potential directly, without complicated treatment of the interaction with higher derivatives by a method of constrained dynamics.

  11. [EMD Time-Frequency Analysis of Raman Spectrum and NIR].

    Science.gov (United States)

    Zhao, Xiao-yu; Fang, Yi-ming; Tan, Feng; Tong, Liang; Zhai, Zhe

    2016-02-01

    This paper analyzes the Raman spectrum and Near Infrared Spectrum (NIR) with time-frequency method. The empirical mode decomposition spectrum becomes intrinsic mode functions, which the proportion calculation reveals the Raman spectral energy is uniform distributed in each component, while the NIR's low order intrinsic mode functions only undertakes fewer primary spectroscopic effective information. Both the real spectrum and numerical experiments show that the empirical mode decomposition (EMD) regard Raman spectrum as the amplitude-modulated signal, which possessed with high frequency adsorption property; and EMD regards NIR as the frequency-modulated signal, which could be preferably realized high frequency narrow-band demodulation during first-order intrinsic mode functions. The first-order intrinsic mode functions Hilbert transform reveals that during the period of empirical mode decomposes Raman spectrum, modal aliasing happened. Through further analysis of corn leaf's NIR in time-frequency domain, after EMD, the first and second orders components of low energy are cut off, and reconstruct spectral signal by using the remaining intrinsic mode functions, the root-mean-square error is 1.001 1, and the correlation coefficient is 0.981 3, both of these two indexes indicated higher accuracy in re-construction; the decomposition trend term indicates the absorbency is ascending along with the decreasing to wave length in the near-infrared light wave band; and the Hilbert transform of characteristic modal component displays, 657 cm⁻¹ is the specific frequency by the corn leaf stress spectrum, which could be regarded as characteristic frequency for identification.

  12. Applying Analytical Derivative and Sparse Matrix Techniques to Large-Scale Process Optimization Problems

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The performance of analytical derivative and sparse matrix techniques applied to a traditional densesequential quadratic programming(SQP) is studied, and the strategy utilizing those techniques is also presented. Computational results on two typicalchemical optimization problems demonstrate significant enhancement in efficiency, which shows this strategy ispromising and suitable for large-scale process optimization problems.

  13. Multipotent Stromal Cells Outperform Chondrocytes on Cartilage-Derived Matrix Scaffolds

    NARCIS (Netherlands)

    Benders, K.E.M.; Boot, W.; Cokelaere, S.M.; Weeren, van P.R.; Gawlitta, D.; Bergman, H.J.; Saris, D.B.F.; Dhert, W.J.A.; Malda, J.

    2014-01-01

    Objective. Although extracellular matrix (ECM)–derived scaffolds have been extensively studied and applied in a number of clinical applications, the use of ECM as a biomaterial for (osteo)chondral regeneration is less extensively explored. This study aimed at evaluating the chondrogenic potential of

  14. Multipotent stromal cells outperform chondrocytes on cartilage-derived matrix scaffolds

    NARCIS (Netherlands)

    Benders, K.E.M.; Boot, W.; van Weeren, René; Gawlitta, D.; Bergman, E.; Saris, D.B.F.; Dhert, Wouter; Malda, Jos

    2014-01-01

    Objective. Although extracellular matrix (ECM)–derived scaffolds have been extensively studied and applied in a number of clinical applications, the use of ECM as a biomaterial for (osteo)chondral regeneration is less extensively explored. This study aimed at evaluating the chondrogenic potential of

  15. Histological evaluation of mineral trioxide aggregate and enamel matrix derivative combination in direct pulp capping: An in vivo study

    Science.gov (United States)

    Bollu, Indira Priyadarshini; Velagula, L. Deepa; Bolla, Nagesh; Kumar, K. Kiran; Hari, Archana; Thumu, Jayaprakash

    2016-01-01

    Aim: The aim of this study is to evaluate the response of human pulp tissue to mineral trioxide aggregate (MTA), Emdogain (EMD), and combination of MTA/EMD. Materials and Methods: This study was performed on sixty intact first and second premolars of human maxillary and mandibular teeth. A standard pulpal exposure was done on all the teeth and was divided into three groups of twenty teeth each and was capped with MTA, EMD, and MTA/EMD combination. The final restoration was done with resin-modified glass ionomer cement. The teeth were then extracted on the 15th or 45th day and histological evaluation done. Results: Differences in inflammatory response and thickness of dentin bridge formation of the exposed pulp to the three different groups were statistically evaluated using Chi-square and Mann–Whitney tests and were found to be significant. No significant difference was found between MTA/EMD and MTA in terms of calcified bridge formation and pulp inflammatory response to the capping materials. Conclusions: MTA and MTA/EMD combination produced a better quality hard tissue response compared with the use of EMD. PMID:27994315

  16. Gear Crack Level Classification Based on EMD and EDT

    Directory of Open Access Journals (Sweden)

    Haiping Li

    2015-01-01

    Full Text Available Gears are the most essential parts in rotating machinery. Crack fault is one of damage modes most frequently occurring in gears. So, this paper deals with the problem of different crack levels classification. The proposed method is mainly based on empirical mode decomposition (EMD and Euclidean distance technique (EDT. First, vibration signal acquired by accelerometer is processed by EMD and intrinsic mode functions (IMFs are obtained. Then, a correlation coefficient based method is proposed to select the sensitive IMFs which contain main gear fault information. And energy of these IMFs is chosen as the fault feature by comparing with kurtosis and skewness. Finally, Euclidean distances between test sample and four classes trained samples are calculated, and on this basis, fault level classification of the test sample can be made. The proposed approach is tested and validated through a gearbox experiment, in which four crack levels and three kinds of loads are utilized. The results show that the proposed method has high accuracy rates in classifying different crack levels and may be adaptive to different conditions.

  17. Crack Diagnosis of Wind Turbine Blades Based on EMD Method

    Science.gov (United States)

    Hong-yu, CUI; Ning, DING; Ming, HONG

    2016-11-01

    Wind turbine blades are both the source of power and the core technology of wind generators. After long periods of time or in some extreme conditions, cracks or damage can occur on the surface of the blades. If the wind generators continue to work at this time, the crack will expand until the blade breaks, which can lead to incalculable losses. Therefore, a crack diagnosis method based on EMD for wind turbine blades is proposed in this paper. Based on aerodynamics and fluid-structure coupling theory, an aero-elastic analysis on wind turbine blades model is first made in ANSYS Workbench. Second, based on the aero-elastic analysis and EMD method, the blade cracks are diagnosed and identified in the time and frequency domains, respectively. Finally, the blade model, strain gauge, dynamic signal acquisition and other equipment are used in an experimental study of the aero-elastic analysis and crack damage diagnosis of wind turbine blades to verify the crack diagnosis method proposed in this paper.

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

    Science.gov (United States)

    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.

  19. Efficient EMD-based Similarity Search in Multimedia Databases via Flexible Dimensionality Reduction

    DEFF Research Database (Denmark)

    Wichterich, Marc; Assent, Ira; Philipp, Kranen

    2008-01-01

    dimensionality reduction techniques for the EMD in a filter-and-refine architecture for efficient lossless retrieval. Thorough experimental evaluation on real world data sets demonstrates a substantial reduction of the number of expensive high-dimensional EMD computations and thus remarkably faster response...

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

    Directory of Open Access Journals (Sweden)

    Kevin Dzobo

    2016-08-01

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

  1. RNS derivation of N-point disk amplitudes from the revisited S-matrix approach

    Energy Technology Data Exchange (ETDEWEB)

    Barreiro, Luiz Antonio, E-mail: luiz.a.barreiro@gmail.com [Departamento de Física, UNESP, Rio Claro, São Paulo (Brazil); Instituto de Matemática e Computação, Universidade Federal de Itajubá, Itajubá, Minas Gerais (Brazil); Medina, Ricardo, E-mail: rmedina50@gmail.com [Instituto de Matemática e Computação, Universidade Federal de Itajubá, Itajubá, Minas Gerais (Brazil)

    2014-09-15

    Recently, in [7] we proposed a revisited S-matrix approach to efficiently find the bosonic terms of the open superstring low energy effective lagrangian (OSLEEL). This approach allows to compute the α{sup ′N} terms of the OSLEEL using open superstring n-point amplitudes in which n is considerably lower than (N+2) (which is the order of the required amplitude to obtain those α{sup ′N} terms by means of the conventional S-matrix approach). In this work we use our revisited S-matrix approach to examine the structure of the scattering amplitudes, arriving at a closed form for them. This is a RNS derivation of the formula first found by Mafra, Schlotterer and Stieberger [21], using the pure spinor formalism. We have succeeded doing this for the 5, 6 and 7-point amplitudes. In order to achieve these results we have done a careful analysis of the kinematical structure of the amplitudes, finding as a by-product a purely kinematical derivation of the BCJ relations (for N=4,5,6 and 7). Also, following the spirit of the revisited S-matrix approach, we have found the α{sup ′} expansions for these amplitudes up to α{sup ′6} order in some cases, by only using the well known open superstring 4-point amplitude, cyclic symmetry and tree level unitarity: we have not needed to compute any numerical series or any integral involving polylogarithms, at any moment.

  2. Neutrophil-Derived MMP-8 Drives AMPK-Dependent Matrix Destruction in Human Pulmonary Tuberculosis.

    Directory of Open Access Journals (Sweden)

    Catherine W M Ong

    2015-05-01

    Full Text Available Pulmonary cavities, the hallmark of tuberculosis (TB, are characterized by high mycobacterial load and perpetuate the spread of M. tuberculosis. The mechanism of matrix destruction resulting in cavitation is not well defined. Neutrophils are emerging as key mediators of TB immunopathology and their influx are associated with poor outcomes. We investigated neutrophil-dependent mechanisms involved in TB-associated matrix destruction using a cellular model, a cohort of 108 patients, and in separate patient lung biopsies. Neutrophil-derived NF-kB-dependent matrix metalloproteinase-8 (MMP-8 secretion was up-regulated in TB and caused matrix destruction both in vitro and in respiratory samples of TB patients. Collagen destruction induced by TB infection was abolished by doxycycline, a licensed MMP inhibitor. Neutrophil extracellular traps (NETs contain MMP-8 and are increased in samples from TB patients. Neutrophils lined the circumference of human pulmonary TB cavities and sputum MMP-8 concentrations reflected TB radiological and clinical disease severity. AMPK, a central regulator of catabolism, drove neutrophil MMP-8 secretion and neutrophils from AMPK-deficient patients secrete lower MMP-8 concentrations. AMPK-expressing neutrophils are present in human TB lung biopsies with phospho-AMPK detected in nuclei. These data demonstrate that neutrophil-derived MMP-8 has a key role in the immunopathology of TB and is a potential target for host-directed therapy in this infectious disease.

  3. RNS derivation of N-point disk amplitudes from the revisited S-matrix approach

    Directory of Open Access Journals (Sweden)

    Luiz Antonio Barreiro

    2014-09-01

    Full Text Available Recently, in [7] we proposed a revisited S-matrix approach to efficiently find the bosonic terms of the open superstring low energy effective lagrangian (OSLEEL. This approach allows to compute the α′N terms of the OSLEEL using open superstring n-point amplitudes in which n is considerably lower than (N+2 (which is the order of the required amplitude to obtain those α′N terms by means of the conventional S-matrix approach. In this work we use our revisited S-matrix approach to examine the structure of the scattering amplitudes, arriving at a closed form for them. This is a RNS derivation of the formula first found by Mafra, Schlotterer and Stieberger [21], using the pure spinor formalism. We have succeeded doing this for the 5, 6 and 7-point amplitudes. In order to achieve these results we have done a careful analysis of the kinematical structure of the amplitudes, finding as a by-product a purely kinematical derivation of the BCJ relations (for N=4,5,6 and 7. Also, following the spirit of the revisited S-matrix approach, we have found the α′ expansions for these amplitudes up to α′6 order in some cases, by only using the well known open superstring 4-point amplitude, cyclic symmetry and tree level unitarity: we have not needed to compute any numerical series or any integral involving polylogarithms, at any moment.

  4. Matrix stiffness determines the fate of nucleus pulposus-derived stem cells.

    Science.gov (United States)

    Navaro, Yosi; Bleich-Kimelman, Nadav; Hazanov, Lena; Mironi-Harpaz, Iris; Shachaf, Yonatan; Garty, Shai; Smith, Yoav; Pelled, Gadi; Gazit, Dan; Seliktar, Dror; Gazit, Zulma

    2015-05-01

    Intervertebral disc (IVD) degeneration and consequent low-back pain present a major medical challenge. Nucleus pulposus-derived stem cells (NP-SCs) may lead to a novel therapy for this severe disease. It was recently shown that survival and function of mature NP cells are regulated in part by tissue stiffness. We hypothesized that modification of matrix stiffness will influence the ability of cultured NP-SCs to proliferate, survive, and differentiate into mature NP cells. NP-SCs were subcultured in three-dimensional matrices of varying degrees of stiffness as measured by the material's shear storage modulus. Cell survival, activity, and rate of differentiation toward the chondrogenic or osteogenic lineage were analyzed. NP-SCs were found to proliferate and differentiate in all matrices, irrespective of matrix stiffness. However, matrices with a low shear storage modulus (G' = 1 kPa) promoted significantly more proliferation and chondrogenic differentiation, whereas matrices with a high modulus (G' = 2 kPa) promoted osteogenic differentiation. Imaging performed via confocal and scanning electron microscopes validated cell survival and highlighted stiffness-dependent cell-matrix interactions. These results underscore the effect of the matrix modulus on the fate of NP-SCs. This research may facilitate elucidation of the complex cross-talk between NP-SCs and their surrounding matrix in healthy as well as pathological conditions.

  5. Derivation of Exact Eigenvalues and Eigenfunctions Based on the Analytical Transfer Matrix Method

    Institute of Scientific and Technical Information of China (English)

    HE Ying; CAO Zhuang-Qi; SHEN Qi-Shun

    2004-01-01

    @@ We extend the analytical transfer matrix method (ATMM) to calculate both the energy eigenvalues and wavefunctions for the Morse potential and the regulated Coulomb potential. Derivations of the exact eigenenergies and eigenfunctions are presented in detail by the ATMM. We compare our results with that obtained by relaxational approach and the eigenvalue moment method, and it is shown that the ATMM can produce accurate eigenvalues.The eigenfunctions by the ATMM are also proven to be correct and meaningful.

  6. Root maturation and dentin–pulp response to enamel matrix derivative in pulpotomized permanent teeth

    OpenAIRE

    Darwish, Sherif S; Shadia H Abd El Meguid; Wahba, Nadia A; Ahmed A-R Mohamed; Wojciech Chrzanowski; Abou Neel, Ensanya A.

    2014-01-01

    The success of pulpotomy of young permanent teeth depends on the proper selection of dressing materials. This study aimed to evaluate the histological and histomorphometric response of dentin–pulp complex to the enamel matrix derivative (Emdogain® gel) compared to that of calcium hydroxide when used as a pulp dressing in immature young permanent dogs’ teeth. Dentin-like tissues bridging the full width of the coronal pu...

  7. Nonlinear Maps Satisfying Derivability on the Parabolic Subalgebras of the Full Matrix Algebras

    Institute of Scientific and Technical Information of China (English)

    Zheng Xin CHEN; Yu E ZHAO

    2011-01-01

    Let F be a field of characteristic O,Mn(F) the full matrix algebra over F,t the subalgebra of Mn(F) consisting of all upper triangular matrices.Any subalgebra of Mn(F) containing t is called a parabolic subalgebra of Mn(F).Let P be a parabolic subalgebra of Mn(F).A map φ on P is said to satisfy derivability if φ(x·y) =φ(x).y+x·φ(y) for all x,y ∈ P,where φ is not necessarily linear.Note that a map satisfying derivability on P is not necessarily a derivation on P.In this paper,we prove that a map φ on P satisfies derivability if and only if φ is a sum of an inner derivation and an additive quasi-derivation on P.In particular,any derivation of parabolic subalgebras of Mn (F) is an inner derivation.

  8. Cell-Derived Extracellular Matrix: Basic Characteristics and Current Applications in Orthopedic Tissue Engineering.

    Science.gov (United States)

    Zhang, Weixiang; Zhu, Yun; Li, Jia; Guo, Quanyi; Peng, Jiang; Liu, Shichen; Yang, Jianhua; Wang, Yu

    2016-06-01

    The extracellular matrix (ECM) is a dynamic and intricate microenvironment with excellent biophysical, biomechanical, and biochemical properties, which can directly or indirectly regulate cell proliferation, adhesion, migration, and differentiation, as well as plays key roles in homeostasis and regeneration of tissues and organs. The ECM has attracted a great deal of attention with the rapid development of tissue engineering in the field of regenerative medicine. Tissue-derived ECM scaffolds (also referred to as decellularized tissues and whole organs) are considered a promising therapy for the repair of musculoskeletal defects, including those that are widely used in orthopedics, although there are a few shortcomings. Similar to tissue-derived ECM scaffolds, cell-derived ECM scaffolds also have highly advantageous biophysical and biochemical properties, in particular their ability to be produced in vitro from a number of different cell types. Furthermore, cell-derived ECM scaffolds more closely resemble native ECM microenvironments. The products of cell-derived ECM have a wide range of biomedical applications; these include reagents for cell culture substrates and biomaterials for scaffolds, hybrid scaffolds, and living cell sheet coculture systems. Although cell-derived ECM has only just begun to be investigated, it has great potential as a novel approach for cell-based tissue repair in orthopedic tissue engineering. This review summarizes and analyzes the various types of cell-derived ECM products applied in cartilage, bone, and nerve tissue engineering in vitro or in vivo and discusses future directions for investigation of cell-derived ECM.

  9. Study on Performance of Remanufactured Engine Based on EMD

    Directory of Open Access Journals (Sweden)

    ZHANG Ying-feng

    2013-07-01

    Full Text Available According to the non-stationary property of vibration signal, the vibration signal is decomposed by empirical mode decomposition (EMD. And this method is applied to study the remanufacturing level of engine. Based on the decomposition of vibration signal, correlation coefficient is introduced to study the correlation between IMF (Intrinsic Mode Function components and original signal, and dynamic structure of IMF components is analyzed by correlation dimension. In order to study the remanufacturing level of engine, correlation coefficient and correlation dimension are considered in the function of IMF, and an index of vibration intensity is proposed. A corresponding relationship is established between remanufacturing level and vibration intensity. This method has been proved that the running state of engine can be reflected by vibration intensity, and this index can be used to evaluate the remanufacturing level of engine.

  10. Genipin-crosslinked cartilage-derived matrix as a scaffold for human adipose-derived stem cell chondrogenesis.

    Science.gov (United States)

    Cheng, Nai-Chen; Estes, Bradley T; Young, Tai-Horng; Guilak, Farshid

    2013-02-01

    Autologous cell-based tissue engineering using three-dimensional scaffolds holds much promise for the repair of cartilage defects. Previously, we reported on the development of a porous scaffold derived solely from native articular cartilage, which can induce human adipose-derived stem cells (ASCs) to differentiate into a chondrogenic phenotype without exogenous growth factors. However, this ASC-seeded cartilage-derived matrix (CDM) contracts over time in culture, which may limit certain clinical applications. The present study aimed to investigate the ability of chemical crosslinking using a natural biologic crosslinker, genipin, to prevent scaffold contraction while preserving the chondrogenic potential of CDM. CDM scaffolds were crosslinked in various genipin concentrations, seeded with ASCs, and then cultured for 4 weeks to evaluate the influence of chemical crosslinking on scaffold contraction and ASC chondrogenesis. At the highest crosslinking degree of 89%, most cells failed to attach to the scaffolds and resulted in poor formation of a new extracellular matrix. Scaffolds with a low crosslinking density of 4% experienced cell-mediated contraction similar to our original report on noncrosslinked CDM. Using a 0.05% genipin solution, a crosslinking degree of 50% was achieved, and the ASC-seeded constructs exhibited no significant contraction during the culture period. Moreover, expression of cartilage-specific genes, synthesis, and accumulation of cartilage-related macromolecules and the development of mechanical properties were comparable to the original CDM. These findings support the potential use of a moderately (i.e., approximately one-half of the available lysine or hydroxylysine residues being crosslinked) crosslinked CDM as a contraction-free biomaterial for cartilage tissue engineering.

  11. Tissue engineering of rat bladder using marrow-derived mesenchymal stem cells and bladder acellular matrix.

    Directory of Open Access Journals (Sweden)

    Daniel L Coutu

    Full Text Available Bladder replacement or augmentation is required in congenital malformations or following trauma or cancer. The current surgical solution involves enterocystoplasty but is associated with high complication rates. Strategies for bladder tissue engineering are thus actively sought to address this unmet clinical need. Because of the poor efficacy of synthetic polymers, the use of bladder acellular matrix (BAM has been proposed. Indeed when cellular components are removed from xenogenic or allogeneic bladders, the extracellular matrix scaffold thus obtained can be used alone or in combination with stem cells. In this study, we propose the use of BAM seeded with marrow-derived mesenchymal stem cells (MSCs for bladder tissue engineering. We optimized a protocol for decellularization of bladder tissue from different species including rat, rabbit and swine. We demonstrate the use of non-ionic detergents followed by nuclease digestion results in efficient decellularization while preserving the extracellular matrix. When MSCs were seeded on acellular matrix scaffold, they remained viable and proliferative while adopting a cellular phenotype consistent with their microenvironment. Upon transplantation in rats after partial cystectomy, MSC-seeded BAM proved superior to unseeded BAM with animals recovering nearly 100% normal bladder capacity for up to six months. Histological analyses also demonstrated increased muscle regeneration.

  12. RNS derivation of N-point disk amplitudes from the revisited S-matrix approach

    CERN Document Server

    Barreiro, Luiz Antonio

    2014-01-01

    In the past year, in arXiv:1208.6066 we proposed a revisited S-matrix approach to efficiently find the bosonic terms of the open superstring low energy effective lagrangian (OSLEEL). This approach allows to compute the ${\\alpha'}^N$ terms of the OSLEEL using open superstring $n$-point amplitudes in which $n$ is very much lower than $(N+2)$ (which is the order of the required amplitude to obtain those ${\\alpha'}^N$ terms by means of the conventional S-matrix approach). In this work we use our revisited S-matrix approach to examine the structure of the scattering amplitudes, arriving at a closed form for them. This is a RNS derivation of the formula first found by Mafra, Schlotterer and Stieberger in arXiv:1106.2645, using the Pure Spinor formalism. We have succeeded doing this for the 5, 6 and 7-point amplitudes. In order to achieve these results we have done a careful analysis of the kinematical structure of the amplitudes, finding as a by-product a purely kinematical derivation of the BCJ relations (for N=4,...

  13. A matrix approach for partial differential equations with Riesz space fractional derivatives

    Science.gov (United States)

    Popolizio, M.

    2013-09-01

    Fractional partial differential equations are emerging in many scientific fields and their numerical solution is becoming a fundamental topic. In this paper we consider the Riesz fractional derivative operator and its discretization by fractional centered differences. The resulting matrix is studied, with an interesting result on a connection between the decay behavior of its entries and the short memory principle from fractional calculus. The Shift-and-Invert method is then applied to approximate the solution of the partial differential equation as the action of the matrix exponential on a suitable vector which mimics the given initial conditions. The numerical results confirm the good approximation quality and encourage the use of the proposed approach.

  14. Histopathological evaluation of the effects of variable extraoral dry times and enamel matrix proteins (enamel matrix derivatives) application on replanted dogs' teeth.

    Science.gov (United States)

    Barbizam, Joao V B; Massarwa, Rasha; da Silva, Lea Assed Bezerra; da Silva, Raquel Assed Bezerra; Nelson-Filho, Paulo; Consolaro, Alberto; Cohenca, Nestor

    2015-02-01

    The extra-alveolar dry period and storage medium in which the tooth was kept prior to replantation remain the critical factors affecting the survival and regeneration of the damaged periodontium. When the replantation is delayed, replacement root resorption is the most common complication following replantation of an avulsed tooth. The aim of this histological study was to evaluate the periodontal healing of replanted dogs' teeth after 20 min (short) and 60 min (long) extraoral dry time with and without the application of enamel matrix proteins. Eighty mature premolar roots (40 teeth) maxillary and mandibular premolars were extracted, the root canals were accessed, instrumented, and filled using a lateral condensation technique, and the access cavity was restored with amalgam. Each root was randomly assigned to one of experimental groups: Groups I and II: Roots were replanted after an extraoral dry time of 20 min. In group II, Emdogain(®) (Biora, Malmo, Sweden) was applied directly to the external root surface with complete coverage. Groups III and IV: Roots were replanted after an extraoral dry time of 60 min. In group IV, Emdogain(®) was applied to the whole external root surface before replantation. Roots that replanted within a total extraoral dry time of 10 min were used as negative controls, while those replanted after 90 min of extraoral dry time were assigned as positive controls. After 4 months, the dogs were euthanized, and the maxillary and mandibular processes were processed for histology and microscopically evaluated. Statistical analysis showed no significant differences (P = 0.1075) among the experimental groups. The results of this study show that 20 min of extraoral dry time is as detrimental to the PDL cells as 60 or 90 min of extraoral dry time, with avulsed dogs' teeth, even when replanted with an inductive material such as EMD. This study provides strong evidence in relation to the threshold of the extraoral dry time of avulsed teeth

  15. In vitro re-hardening of artificial enamel caries lesions using enamel matrix proteins or self-assembling peptides

    Directory of Open Access Journals (Sweden)

    Patrick Schmidlin

    2016-02-01

    Full Text Available ABSTRACT Objectives To assess the re-hardening potential of enamel matrix derivatives (EMD and self-assembling peptides in vitro, hypothesizing that these materials may increase the mineralization of artificial carious lesions and improve hardness profiles. Material and Methods Forty-eight enamel samples were prepared from extracted bovine lower central incisors. After embedding and polishing, nail varnish was applied, leaving a defined test area. One third of this area was covered with a flowable composite (non-demineralized control. The remaining area was demineralized in an acidic buffer solution for 18 d to simulate a carious lesion. Half the demineralized area was then covered with composite (demineralized control, while the last third was left open for three test and one control treatments: (A Application of enamel-matrix proteins (EMD - lyophilized protein fractions dissolved in acetic acid, Straumann, (B self-assembling peptides (SAP, Curodont, or (C amine fluoride solution (Am-F, GABA for 5 min each. Untreated samples (D served as control. After treatment, samples were immersed in artificial saliva for four weeks (remineralization phase and microhardness (Knoop depth profiles (25-300 µm were obtained at sections. Two-way ANOVA was calculated to determine differences between the areas (re-hardening or softening. Results Decalcification resulted in significant softening of the subsurface enamel in all groups (A-D. A significant re-hardening up to 125 µm was observed in the EMD and SAP groups. Conclusions This study showed that EMD and SAP were able to improve the hardness profiles when applied to deep demineralized artificial lesions. However, further research is needed to verify and improve this observed effect.

  16. Holography and hydrodynamics for EMD theory with two Maxwell fields

    CERN Document Server

    Smolic, Milena

    2013-01-01

    We use `generalized dimensional reduction' to relate a specific Einstein-Maxwell-Dilaton (EMD) theory, including two gauge fields, three neutral scalars and an axion, to higher-dimensional AdS gravity (with no higher-dimensional Maxwell field). In general, this is a dimensional reduction over compact Einstein spaces in which the dimension of the compact space is continued to non-integral values. Specifically, we perform a non-diagonal Kaluza-Klein (KK) reduction over a torus, involving two KK gauge fields. Our aim is to determine the holographic dictionary and hydrodynamic behaviour of the lower-dimensional theory by performing the generalized dimensional reduction on AdS. We study a specific example of a black brane carrying a wave, whose universal sector is described by gravity coupled to two Maxwell fields, three neutral scalars and an axion, and compute the first order transport coefficients of the dual theory. In these theories $\\hat{\\z}_s / \\hat{\\eta} < 2(1(d-1)-\\hat{c}_s^2)$, where $\\hat{c}_s$ is th...

  17. Bubaline Cholecyst Derived Extracellular Matrix for Reconstruction of Full Thickness Skin Wounds in Rats

    Directory of Open Access Journals (Sweden)

    Poonam Shakya

    2016-01-01

    Full Text Available An acellular cholecyst derived extracellular matrix (b-CEM of bubaline origin was prepared using anionic biological detergent. Healing potential of b-CEM was compared with commercially available collagen sheet (b-CS and open wound (C in full thickness skin wounds in rats. Thirty-six clinically healthy adult Sprague Dawley rats of either sex were randomly divided into three equal groups. Under general anesthesia, a full thickness skin wound (20 × 20 mm2 was created on the dorsum of each rat. The defect in group I was kept as open wound and was taken as control. In group II, the defect was repaired with commercially available collagen sheet (b-CS. In group III, the defect was repaired with cholecyst derived extracellular matrix of bovine origin (b-CEM. Planimetry, wound contracture, and immunological and histological observations were carried out to evaluate healing process. Significantly (P<0.05 increased wound contraction was observed in b-CEM (III as compared to control (I and b-CS (II on day 21. Histologically, improved epithelization, neovascularization, fibroplasia, and best arranged collagen fibers were observed in b-CEM (III as early as on postimplantation day 21. These findings indicate that b-CEM have potential for biomedical applications for full thickness skin wound repair in rats.

  18. In vitro inhibition of bovine enamel demineralization by enamel matrix derivative.

    Science.gov (United States)

    Ran, Jin Mei; Ieong, Cheng Cheng; Xiang, Chen Yang; Lv, Xue Ping; Xue, Jing; Zhou, Xue Dong; Li, Wei; Zhang, Ling Lin

    2014-01-01

    This study aimed to determine whether enamel matrix derivative (Emdogain) affects the demineralization of bovine enamel in vitro and to assess the agent's anti-caries potential. Bovine enamel blocks were prepared and randomly divided into three groups (n = 15 per group), which were treated with distilled water (negative control), NaF (positive control), or Emdogain. All three groups were pH-cycled 12 times over 6 days. The percentage of surface enamel microhardness reduction (%SMHR), calcium demineralization rate (CDR), surface roughness, lesion depth and mineral loss after demineralization were examined. Surface morphology of specimens was studied by scanning electron microscopy. The Emdogain and positive control groups showed similar surface roughness, lesion depths and mineral loss, which were significantly lower than those in the negative control group. In addition, the enamel surfaces of both the Emdogain and NaF groups showed much narrower intercrystalline spaces than the surfaces of the negative control group, which exhibited extensive microfractures along the crystal edges. %SMHR differed significantly among all three groups, with the smallest value in the Emdogain group and the greatest in the negative control group. These results indicate that enamel matrix derivative (Emdogain) can significantly inhibit demineralization of bovine enamel in vitro, suggesting that it has potential as an anti-caries agent.

  19. Crystal Structures of Al-Nd Codoped Zirconolite Derived from Glass Matrix and Powder Sintering.

    Science.gov (United States)

    Liao, Chang-Zhong; Shih, Kaimin; Lee, William E

    2015-08-03

    Zirconolite is a candidate host for immobilizing long-lived radionuclides. Zirconolite-based glass-ceramics in the CaO-SiO2-Al2O3-TiO2-ZrO2-Nd2O3-Na2O matrix are a potential waste form for immobilizing actinide radionuclides and can offer double barriers to immobilize radioactive elements. However, the X-ray diffraction patterns of the zirconolite derived from the glass matrix (glass ceramic, GC) are significantly different from those prepared by powder sintering (PS). In this Article, the crystal structures of Al-Nd codoped zirconolite grown via the glass matrix route and the powder sintering route are investigated in detail. Two samples of Al-Nd codoped zirconolite were prepared: one was grown from a CaO-SiO2-Al2O3-TiO2-ZrO2-Nd2O3-Na2O glass matrix, and the other was prepared with a Ca0.75Nd0.25ZrTi1.75Al0.25O7 composition by powder sintering. The samples were then characterized using powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), transmission electron microscopy-energy dispersive X-ray spectroscopy (TEM-EDX), and selected area electron diffraction (SAED). The chemical composition of the 100-500 nm zirconolite crystals grown from a glass matrix was determined by TEM-EDX to be Ca0.83Nd0.25Zr0.85Ti1.95Al0.11O7. PXRD and SAED results showed that these two Al-Nd codoped zirconolite phases were crystallized in space group C12/c1. The HRTEM images and SAED results showed that there were heavy stacking faults in the zirconolite crystals grown from the glass matrix. In contrast, far fewer defects were found in the zirconolite crystals prepared by powder sintering. The split-atom model was adopted for the first time to construct the Al-Nd codoped zirconolite structure grown from glass during the Rietveld refinement. The isostructural method assisted by Rietveld refinement was used to resolve the Al-Nd codoped zirconolite structures prepared by different methods. The occupancies of the cation sites were identified, and the distribution behavior of Nd

  20. Consistent schemes for non-adiabatic dynamics derived from partial linearized density matrix propagation.

    Science.gov (United States)

    Huo, Pengfei; Coker, David F

    2012-12-14

    Powerful approximate methods for propagating the density matrix of complex systems that are conveniently described in terms of electronic subsystem states and nuclear degrees of freedom have recently been developed that involve linearizing the density matrix propagator in the difference between the forward and backward paths of the nuclear degrees of freedom while keeping the interference effects between the different forward and backward paths of the electronic subsystem described in terms of the mapping Hamiltonian formalism and semi-classical mechanics. Here we demonstrate that different approaches to developing the linearized approximation to the density matrix propagator can yield a mean-field like approximate propagator in which the nuclear variables evolve classically subject to Ehrenfest-like forces that involve an average over quantum subsystem states, and by adopting an alternative approach to linearizing we obtain an algorithm that involves classical like nuclear dynamics influenced by a quantum subsystem state dependent force reminiscent of trajectory surface hopping methods. We show how these different short time approximations can be implemented iteratively to achieve accurate, stable long time propagation and explore their implementation in different representations. The merits of the different approximate quantum dynamics methods that are thus consistently derived from the density matrix propagator starting point and different partial linearization approximations are explored in various model system studies of multi-state scattering problems and dissipative non-adiabatic relaxation in condensed phase environments that demonstrate the capabilities of these different types of approximations for treating non-adiabatic electronic relaxation, bifurcation of nuclear distributions, and the passage from nonequilibrium coherent dynamics at short times to long time thermal equilibration in the presence of a model dissipative environment.

  1. In vitro cartilage production using an extracellular matrix-derived scaffold and bone marrow-derived mesenchymal stem cells

    Institute of Scientific and Technical Information of China (English)

    ZHAO Yan-hong; YANG Qiang; XIA Qun; PENG Jiang; LU Shi-bi; GUO Quan-yi; MA Xin-long

    2013-01-01

    Background Cartilage repair is a challenging research area because of the limited healing capacity of adult articular cartilage.We had previously developed a natural,human cartilage extracellular matrix (ECM)-derived scaffold for in vivo cartilage tissue engineering in nude mice.However,before these scaffolds can be used in clinical applications in vivo,the in vitro effects should be further explored.Methods We produced cartilage in vitro using a natural cartilage ECM-derived scaffold.The scaffolds were fabricated by combining a decellularization procedure with a freeze-drying technique and were characterized by scanning electron microscopy (SEM),micro-computed tomography (micro-CT),histological staining,cytotoxicity assay,biochemical and biomechanical analysis.After being chondrogenically induced,the induction results of BMSCs were analyzed by histology and Immunohisto-chemistry.The attachment and viability assessment of the cells on scaffolds were analyzed using SEM and LIVE/DEAD staining.Cell-scaffold constructs cultured in vitro for 1 week and 3 weeks were analyzed using histological and immunohistochemical methods.Results SEM and micro-CT revealed a 3-D interconnected porous structure.The majority of the cartilage ECM was found in the scaffold following the removal of cellular debris,and stained positive for safranin O and collagen Ⅱ.Viability staining indicated no cytotoxic effects of the scaffold.Biochemical analysis showed that collagen content was (708.2±44.7)μg/mg,with GAG (254.7±25.9) μg/mg.Mechanical testing showed the compression moduli (E) were (1.226±0.288) and (0.052±0.007) MPa in dry and wet conditions,respectively.Isolated canine bone marrow-derived stem cells (BMSCs) were induced down a chondrogenic pathway,labeled with PKH26,and seeded onto the scaffold.Immunofluorescent staining of the cell-scaffold constructs indicated that chondrocyte-like cells were derived from seeded BMSCs and excreted ECM.The cell-scaffold constructs contained

  2. Tissue-engineered graft constructed by self-derived cells and heterogeneous acellular matrix

    Institute of Scientific and Technical Information of China (English)

    HUANG Hui-min; WU Shao-feng; REN Hong

    2006-01-01

    : Cultured self-derived endothelial and smooth muscle cells could be used as seeding cells and heterogeneous acellularized matrix could be used as scaffold in constructing tissue-engineered graft.

  3. Does mode mixing matter in EMD-based highlight volume methods for hydrocarbon detection? Experimental evidence

    Science.gov (United States)

    Xue, Ya-juan; Cao, Jun-xing; Du, Hao-kun; Zhang, Gu-lan; Yao, Yao

    2016-09-01

    Empirical mode decomposition (EMD)-based spectral decomposition methods have been successfully used for hydrocarbon detection. However, mode mixing that occurs during the sifting process of EMD causes the 'true' intrinsic mode function (IMF) to be extracted incorrectly and blurs the physical meaning of the IMF. We address the issue of how the mode mixing influences the EMD-based methods for hydrocarbon detection by introducing mode-mixing elimination methods, specifically ensemble EMD (EEMD) and complete ensemble EMD (CEEMD)-based highlight volumes, as feasible tools that can identify the peak amplitude above average volume and the peak frequency volume. Three schemes, that is, using all IMFs, selected IMFs or weighted IMFs, are employed in the EMD-, EEMD- and CEEMD-based highlight volume methods. When these methods were applied to seismic data from a tight sandstone gas field in Central Sichuan, China, the results demonstrated that the amplitude anomaly in the peak amplitude above average volume captured by EMD, EEMD and CEEMD combined with Hilbert transforms, whether using all IMFs, selected IMFs or weighted IMFs, are almost identical to each other. However, clear distinctions can be found in the peak frequency volume when comparing results generated using all IMFs, selected IMFs, or weighted IMFs. If all IMFs are used, the influence of mode mixing on the peak frequency volume is not readily discernable. However, using selected IMFs or a weighted IMFs' scheme affects the peak frequency in relation to the reservoir thickness in the EMD-based method. Significant improvement in the peak frequency volume can be achieved in EEMD-based highlight volumes using selected IMFs. However, if the weighted IMFs' scheme is adopted (i.e., if the undesired IMFs are included with reduced weights rather than excluded from the analysis entirely), the CEEMD-based peak frequency volume provides a more accurate reservoir thickness estimate compared with the other two methods. This

  4. System and methods for determining masking signals for applying empirical mode decomposition (EMD) and for demodulating intrinsic mode functions obtained from application of EMD

    Science.gov (United States)

    Senroy, Nilanjan; Suryanarayanan, Siddharth

    2011-03-15

    A computer-implemented method of signal processing is provided. The method includes generating one or more masking signals based upon a computed Fourier transform of a received signal. The method further includes determining one or more intrinsic mode functions (IMFs) of the received signal by performing a masking-signal-based empirical mode decomposition (EMD) using the at least one masking signal.

  5. Identification of acceleration pulses in near-fault ground motion using the EMD method

    Institute of Scientific and Technical Information of China (English)

    Zhang Yushan; Hu Yuxian; Zhao Fengxin; Liang Jianwen; Yang Caihong

    2005-01-01

    In this paper, response spectral characteristics of one-, two-, and three-lobe sinusoidal acceleration pulses are investigated, and some of their basic properties are derived. Furthermore, the empirical mode decomposition (EMD) method is utilized as an adaptive filter to decompose the near-fault pulse-like ground motions, which were recorded during the September 20, 1999, Chi-Chi earthquake. These ground motions contain distinct velocity pulses, and were decomposed into high-frequency (HF) and low-frequency (LF) components, from which the corresponding HF acceleration pulse (if existing)and LF acceleration pulse could be easily identified and detected. Finally, the identified acceleration pulses are modeled by simplified sinusoidal approximations, whose dynamic behaviors are compared to those of the original acceleration pulses as well as to those of the original HF and LF acceleration components in the context of elastic response spectra. It was demonstrated that it is just the acceleration pulses contained in the near-fault pulse-like ground motion that fundamentally dominate the special impulsive dynamic behaviors of such motion in an engineering sense. The motion thus has a greater potential to cause severe damage than the far-field ground motions, i.e. they impose high base shear demands on engineering structures as well as placing very high deformation demands on long-period structures.

  6. Processing and Material Characterization of Continuous Basalt Fiber Reinforced Ceramic Matrix Composites Using Polymer Derived Ceramics.

    Science.gov (United States)

    Cox, Sarah B.

    2014-01-01

    The need for high performance vehicles in the aerospace industry requires materials which can withstand high loads and high temperatures. New developments in launch pads and infrastructure must also be made to handle this intense environment with lightweight, reusable, structural materials. By using more functional materials, better performance can be seen in the launch environment, and launch vehicle designs which have not been previously used can be considered. The development of high temperature structural composite materials has been very limited due to the high cost of the materials and the processing needed. Polymer matrix composites can be used for temperatures up to 260C. Ceramics can take much higher temperatures, but they are difficult to produce and form in bulk volumes. Polymer Derived Ceramics (PDCs) begin as a polymer matrix, allowing a shape to be formed and cured and then to be pyrolized in order to obtain a ceramic with the associated thermal and mechanical properties. The use of basalt in structural and high temperature applications has been under development for over 50 years, yet there has been little published research on the incorporation of basalt fibers as a reinforcement in the composites. In this study, continuous basalt fiber reinforced PDCs have been fabricated and tested for the applicability of this composite system as a high temperature structural composite material. The oxyacetylene torch testing and three point bend testing have been performed on test panels and the test results are presented.

  7. Amino Acid Derivatives as New Zinc Binding Groups for the Design of Selective Matrix Metalloproteinase Inhibitors

    Directory of Open Access Journals (Sweden)

    Mariateresa Giustiniano

    2013-01-01

    Full Text Available A number of matrix metalloproteinases (MMPs are important medicinal targets for conditions ranging from rheumatoid arthritis to cardiomyopathy, periodontal disease, liver cirrhosis, multiple sclerosis, and cancer invasion and metastasis, where they showed to have a dual role, inhibiting or promoting important processes involved in the pathology. MMPs contain a zinc (II ion in the protein active site. Small-molecule inhibitors of these metalloproteins are designed to bind directly to the active site metal ions. In an effort to devise new approaches to selective inhibitors, in this paper, we describe the synthesis and preliminary biological evaluation of amino acid derivatives as new zinc binding groups (ZBGs. The incorporation of selected metal-binding functions in more complex biphenyl sulfonamide moieties allowed the identification of one compound able to interact selectively with different MMP enzymatic isoforms.

  8. Best linear unbiased prediction of genomic breeding values using a trait-specific marker-derived relationship matrix.

    Directory of Open Access Journals (Sweden)

    Zhe Zhang

    Full Text Available BACKGROUND: With the availability of high density whole-genome single nucleotide polymorphism chips, genomic selection has become a promising method to estimate genetic merit with potentially high accuracy for animal, plant and aquaculture species of economic importance. With markers covering the entire genome, genetic merit of genotyped individuals can be predicted directly within the framework of mixed model equations, by using a matrix of relationships among individuals that is derived from the markers. Here we extend that approach by deriving a marker-based relationship matrix specifically for the trait of interest. METHODOLOGY/PRINCIPAL FINDINGS: In the framework of mixed model equations, a new best linear unbiased prediction (BLUP method including a trait-specific relationship matrix (TA was presented and termed TABLUP. The TA matrix was constructed on the basis of marker genotypes and their weights in relation to the trait of interest. A simulation study with 1,000 individuals as the training population and five successive generations as candidate population was carried out to validate the proposed method. The proposed TABLUP method outperformed the ridge regression BLUP (RRBLUP and BLUP with realized relationship matrix (GBLUP. It performed slightly worse than BayesB with an accuracy of 0.79 in the standard scenario. CONCLUSIONS/SIGNIFICANCE: The proposed TABLUP method is an improvement of the RRBLUP and GBLUP method. It might be equivalent to the BayesB method but it has additional benefits like the calculation of accuracies for individual breeding values. The results also showed that the TA-matrix performs better in predicting ability than the classical numerator relationship matrix and the realized relationship matrix which are derived solely from pedigree or markers without regard to the trait. This is because the TA-matrix not only accounts for the Mendelian sampling term, but also puts the greater emphasis on those markers that

  9. Function of cancer cell-derived extracellular matrix in tumor progression

    Institute of Scientific and Technical Information of China (English)

    Gao-Feng Xiong; Ren Xu

    2016-01-01

    Extracellular matrix (ECM) is an essential component of the tumor microenvironment. Cancer development and progression are associated with increased ECM deposition and crosslink. The chemical and physical signals elicited from ECM are necessary for cancer cell proliferation and invasion. It is well recognized that stromal cells are a major source of ECM proteins. However, recent studies showed that cancer cells are also an active and important component in ECM remodeling. Cancer cells deposit a signiifcant amount of collagen, ifbronectin, and tenascin C (TNC). Recent studies demonstrate that these cancer cell-derived ECM proteins enhance cancer cell survival and promote cancer cell colonization at distant sites. ECM-related enzymes and chaperone proteins, such as prolyl-4-hydroxylase, lysyl-hydroxylase, lysyl oxidase, and heat shock protein 47, are also highly expressed in cancer cells. Inhibition of these enzymes signiifcantly reduces cancer growth, invasion, and metastasis. These factors suggest that the cancer cell-derived ECM is crucial for cancer progression and metastasis. Therefore, targeting these ECM proteins and ECM-related enzymes is a potential strategy for cancer treatment.

  10. Bone marrow derived cell-seeded extracellular matrix: A novel biomaterial in the field of wound management

    Directory of Open Access Journals (Sweden)

    V. Remya

    2014-11-01

    Full Text Available Aim: Extensive or irreversible damage to the skin often requires additional skin substitutes for reconstruction. Biomaterials have become critical components in the development of effective new medical therapies for wound care. Materials and Methods: In the present study, a cell matrix construct (bone marrow-derived cells (BMdc seeded extracellular matrix [ECM] was used as a biological substitute for the repair of full-thickness skin wound. ECM was developed by decellularizing fish swim bladder (FSB. Goat bone marrow-derived cells (G-BMdc were seeded over this decellularized matrix. Efficacy of this cell matrix construct in wound repair was tested by implanting it over 20 mm2 × 20 mm2 size fullthickness skin wound created over the dorsum of rat. The study was conducted in 16 clinically healthy adult rats of either sex. The animals were randomly divided into 2 equal groups of 8 animals each. In Group I, animal’s wounds were repaired with a cellular FSB matrix. In Group II, wounds were repaired with G-BMdc seeded a cellular FSB matrix. Immune response and efficacy of healing were analyzed. Results: Quality of healing and immuno tolerance to the biological substitute was significantly better in Group II than Group I. Conclusion: Seeding with BMdc increases the wound healing potency and modulates the immune response to a significantly negligible level. The BMdc seeded acellular FSB matrix was found to be a novel biomaterial for wound management.

  11. clickECM: Development of a cell-derived extracellular matrix with azide functionalities.

    Science.gov (United States)

    Ruff, S M; Keller, S; Wieland, D E; Wittmann, V; Tovar, G E M; Bach, M; Kluger, P J

    2016-12-10

    In vitro cultured cells produce a complex extracellular matrix (ECM) that remains intact after decellularization. The biological complexity derived from the variety of distinct ECM molecules makes these matrices ideal candidates for biomaterials. Biomaterials with the ability to guide cell function are a topic of high interest in biomaterial development. However, these matrices lack specific addressable functional groups, which are often required for their use as a biomaterial. Due to the biological complexity of the cell-derived ECM, it is a challenge to incorporate such functional groups without affecting the integrity of the biomolecules within the ECM. The azide-alkyne cycloaddition (click reaction, Huisgen-reaction) is an efficient and specific ligation reaction that is known to be biocompatible when strained alkynes are used to avoid the use of copper (I) as a catalyst. In our work, the ubiquitous modification of a fibroblast cell-derived ECM with azides was achieved through metabolic oligosaccharide engineering by adding the azide-modified monosaccharide Ac4GalNAz (1,3,4,6-tetra-O-acetyl-N-azidoacetylgalactosamine) to the cell culture medium. The resulting azide-modified network remained intact after removing the cells by lysis and the molecular structure of the ECM proteins was unimpaired after a gentle homogenization process. The biological composition was characterized in order to show that the functionalization does not impair the complexity and integrity of the ECM. The azides within this "clickECM" could be accessed by small molecules (such as an alkyne-modified fluorophore) or by surface-bound cyclooctynes to achieve a covalent coating with clickECM.

  12. Research of fractal diagnosis method for gearbox based on EMD and SVD%基于EMD与SVD的齿轮箱分形诊断方法研究

    Institute of Scientific and Technical Information of China (English)

    闫鹏程; 孙华刚; 毛向东; 冯广斌

    2012-01-01

    提出了一种基于经验模态分解(EMD)与奇异值分解(SVD)的机械振动系统故障分形诊断方法.该方法首先将EMD和SVD相结合,对信号进行分解和特征筛选,通过重组所得轨道矩阵,实现对机械系统振动信号不同特征信息的提取.然后利用Kolmogorov熵、多重分形等动力学分析方法,对降噪振动信号进行分形诊断.在直齿轮减速箱故障识别中的应用表明,该方法不仅有效提取出了系统的特征信息,而且可实现对系统状态和细微故障差别的有效识别,并可给出定量判据.%A fractal diagnosis method for the mechanical vibration system based on empirical mode decomposition (EMD) and singular value decomposition (SVD) is proposed. Firstly, with EMD and SVD, the signal is decomposed. The orbit matrix can be obtained through characteristic selection. And the different diagnostic information of the vibration signal can be extracted with the orbit matrix recombination. Then the denoising signal can be analyzed by the dynamistic analysis methods, such as Kolmogorov entropy, multi-fractal, and so on. The application to the failure recognition of the spur gearbox shows that the method not only effectively extracts the characteristics of the system, but also achieves the effective recognition of the system state. And the quantitative criterion can be presented. It can provide the difference identification of imperceptible fault for the system.

  13. Tailoring the properties of cholecyst-derived extracellular matrix using carbodiimide cross-linking.

    LENUS (Irish Health Repository)

    Burugapalli, Krishna

    2009-01-01

    Modulation of properties of extracellular matrix (ECM) based scaffolds is key for their application in the clinical setting. In the present study, cross-linking was used as a tool for tailoring the properties of cholecyst-derived extracellular matrix (CEM). CEM was cross-linked with varying cross-linking concentrations of N,N-(3-dimethyl aminopropyl)-N\\'-ethyl carbodiimide (EDC) in the presence of N-hydroxysuccinimide (NHS). Shrink temperature measurements and ATR-FT-IR spectra were used to determine the degree of cross-linking. The effect of cross-linking on degradation was tested using the collagenase assay. Uniaxial tensile properties and the ability to support fibroblasts were also evaluated as a function of cross-linking. Shrink temperature increased from 59 degrees C for non-cross-linked CEM to 78 degrees C for the highest EDC cross-linking concentration, while IR peak area ratios for the free -NH(2) group at 3290 cm(-1) to that of the amide I band at 1635 cm(-1) decreased with increasing EDC cross-linking concentration. Collagenase assay demonstrated that degradation rates for CEM can be tailored. EDC concentrations 0 to 0.0033 mmol\\/mg CEM were the cross-linking concentration range in which CEM showed varied susceptibility to collagenase degradation. Furthermore, cross-linking concentrations up to 0.1 mmol EDC\\/mg CEM did not have statistically significant effect on the uniaxial tensile strength, as well as morphology, viability and proliferation of fibroblasts on CEM. In conclusion, the degradation rates of CEM can be tailored using EDC-cross-linking, while maintaining the mechanical properties and the ability of CEM to support cells.

  14. Derivation of an amino acid similarity matrix for peptide:MHC binding and its application as a Bayesian prior

    Directory of Open Access Journals (Sweden)

    Sette Alessandro

    2009-11-01

    Full Text Available Abstract Background Experts in peptide:MHC binding studies are often able to estimate the impact of a single residue substitution based on a heuristic understanding of amino acid similarity in an experimental context. Our aim is to quantify this measure of similarity to improve peptide:MHC binding prediction methods. This should help compensate for holes and bias in the sequence space coverage of existing peptide binding datasets. Results Here, a novel amino acid similarity matrix (PMBEC is directly derived from the binding affinity data of combinatorial peptide mixtures. Like BLOSUM62, this matrix captures well-known physicochemical properties of amino acid residues. However, PMBEC differs markedly from existing matrices in cases where residue substitution involves a reversal of electrostatic charge. To demonstrate its usefulness, we have developed a new peptide:MHC class I binding prediction method, using the matrix as a Bayesian prior. We show that the new method can compensate for missing information on specific residues in the training data. We also carried out a large-scale benchmark, and its results indicate that prediction performance of the new method is comparable to that of the best neural network based approaches for peptide:MHC class I binding. Conclusion A novel amino acid similarity matrix has been derived for peptide:MHC binding interactions. One prominent feature of the matrix is that it disfavors substitution of residues with opposite charges. Given that the matrix was derived from experimentally determined peptide:MHC binding affinity measurements, this feature is likely shared by all peptide:protein interactions. In addition, we have demonstrated the usefulness of the matrix as a Bayesian prior in an improved scoring-matrix based peptide:MHC class I prediction method. A software implementation of the method is available at: http://www.mhc-pathway.net/smmpmbec.

  15. A method for extracting fetal ECG based on EMD-NMF single channel blind source separation algorithm.

    Science.gov (United States)

    He, Pengju; Chen, Xiaomeng

    2015-01-01

    Nowadays, detecting fetal ECG using abdominal signal is a commonly used method, but fetal ECG signal will be affected by maternal ECG. Current FECG extraction algorithms are mainly aiming at multiple channels signal. They often assume there is only one fetus and did not consider multiple births. This paper proposed a single channel blind source separation algorithm to process single abdominal acquired signal. This algorithm decomposed single abdominal signal into multiple intrinsic mode function (IMF) utilizing empirical mode decomposition (EMD). Correlation matrix of IMF was calculated and independent ECG signal number was estimated using eigenvalue method. Nonnegative matrix was constructed according to determined number and decomposed IMF. Separation of MECG and FECG was achieved utilizing nonnegative matrix factorization (NMF). Experiments selected four channels man-made signal and two channels ECG to verify correctness and feasibility of proposed algorithm. Results showed that the proposed algorithm could determine number of independent signal in single acquired signal. FECG could be extracted from single channel observed signal and the algorithm can be used to solve separation of MECG and FECG.

  16. A Fault Diagnosis Approach for Broken Rotor Bars Based on EMD and Envelope Analysis

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jian-wen; ZHU Ning-hui; YANG Li; YAO Qi; LU Qing

    2007-01-01

    Empirical Mode Decomposition (EMD) used to deal with non-linear and non-stable signals, is a time-frequency analytical method that has been developed recently. In this paper the EMD method is used to filter the noise from the stator current signal that arises when rotor bars break. Then a Hilbert Transform is used to extract the envelope from the filtered signal. With the EMD method again, the frequency band containing the fault characteristic-frequency components, 2sf, can be extracted from the signal's envelope. The last step is to use a Fast Fourier Transform (FFT) method to extract the fault characteristic frequency. This frequency can be detected in actual data from a faulty motor, as shown by example. Compared to the Extend Park Vector method this method is proved to be more sensitive under light motor load.

  17. Emotion Recognition from EEG Signals Using Multidimensional Information in EMD Domain

    Directory of Open Access Journals (Sweden)

    Ning Zhuang

    2017-01-01

    Full Text Available This paper introduces a method for feature extraction and emotion recognition based on empirical mode decomposition (EMD. By using EMD, EEG signals are decomposed into Intrinsic Mode Functions (IMFs automatically. Multidimensional information of IMF is utilized as features, the first difference of time series, the first difference of phase, and the normalized energy. The performance of the proposed method is verified on a publicly available emotional database. The results show that the three features are effective for emotion recognition. The role of each IMF is inquired and we find that high frequency component IMF1 has significant effect on different emotional states detection. The informative electrodes based on EMD strategy are analyzed. In addition, the classification accuracy of the proposed method is compared with several classical techniques, including fractal dimension (FD, sample entropy, differential entropy, and discrete wavelet transform (DWT. Experiment results on DEAP datasets demonstrate that our method can improve emotion recognition performance.

  18. An Improved EMD and Its Applications to Find the Basis Functions of EMI Signals

    Directory of Open Access Journals (Sweden)

    Hongyi Li

    2015-01-01

    Full Text Available A B-spline empirical mode decomposition (BEMD method is proposed to improve the celebrated empirical mode decomposition (EMD method. The improvement of BEMD on EMD mainly concentrates on the sifting process. First, instead of the curve that resulted from computing the average of upper and lower envelopes, the curve interpolated by the midpoints of local maximal and minimal points is used as the mean curve, which can reduce the cost of computation. Second, the cubic spline interpolation is replaced with cubic B-spline interpolation on account of the advantages of B-spline over polynomial spline. The effectiveness of BEMD compared with EMD is validated by numerical simulations and an application to find the basis functions of EMI signals.

  19. Emotion Recognition from EEG Signals Using Multidimensional Information in EMD Domain

    Science.gov (United States)

    Zhuang, Ning; Zeng, Ying; Tong, Li; Zhang, Hanming

    2017-01-01

    This paper introduces a method for feature extraction and emotion recognition based on empirical mode decomposition (EMD). By using EMD, EEG signals are decomposed into Intrinsic Mode Functions (IMFs) automatically. Multidimensional information of IMF is utilized as features, the first difference of time series, the first difference of phase, and the normalized energy. The performance of the proposed method is verified on a publicly available emotional database. The results show that the three features are effective for emotion recognition. The role of each IMF is inquired and we find that high frequency component IMF1 has significant effect on different emotional states detection. The informative electrodes based on EMD strategy are analyzed. In addition, the classification accuracy of the proposed method is compared with several classical techniques, including fractal dimension (FD), sample entropy, differential entropy, and discrete wavelet transform (DWT). Experiment results on DEAP datasets demonstrate that our method can improve emotion recognition performance. PMID:28900626

  20. Expressions for the second-order mixed partial derivatives of Slater-Koster matrix elements at spherical coordinate singularities

    Science.gov (United States)

    Meister, Matthias

    2005-10-01

    In a recent publication it has been shown how to generate derivatives with respect to atom coordinates of Slater-Koster matrix elements for the tight binding modeling of a system. For the special case of a mixed second partial derivative at coordinate singularities only the results were stated in that publication. In this work, the derivation of these results is given in detail. Though it may seem rather technical and only applicable to a very special case, atomic configurations where the connecting vector between the two atoms involved in a two-center matrix element is aligned along the z axis (in the usual approach) require results for precisely this case. The expressions derived in this work have been implemented in the DINAMO code.

  1. Influence of cellulose derivatives and natural polymers on in vitro release kinetics of metoprolol succinate from extended release matrix tablets

    OpenAIRE

    Sunil, R.; Somagoni, Jagan M.; Panakanti, Pavan K.; Ega, Chandra M.; Yamsani, Madhusudan R.

    2011-01-01

    In the present investigation, extended release tablets of metoprolol succinate were developed using cellulose derivatives and natural gums as matrix formers and were evaluated for its extended release characteristics. The optimized formulation (F7) was obtained using cellulose derivatives in the ratio of 1:0.5:1drug, HPMC K 100M and Na CMC, respectively. Prepared tablets were subjected to all the Pharmacopeial quality tests and found to be in the limits. The in vitro release studies of prepar...

  2. Suspension Culture Alters Insulin Secretion in Induced Human Umbilical Cord Matrix-Derived Mesenchymal Cells

    Directory of Open Access Journals (Sweden)

    Fatemeh Seyedi

    2016-04-01

    Full Text Available Objective: Worldwide, diabetes mellitus (DM is an ever-increasing metabolic disorder. A promising approach to the treatment of DM is the implantation of insulin producing cells (IPC that have been derived from various stem cells. Culture conditions play a pivotal role in the quality and quantity of the differentiated cells. In this experimental study, we have applied various culture conditions to differentiate human umbilical cord matrix-derived mesenchymal cells (hUCMs into IPCs and measured insulin production. Materials and Methods: In this experimental study, we exposed hUCMs cells to pancreatic medium and differentiated them into IPCs in monolayer and suspension cultures. Pancreatic medium consisted of serum-free Dulbecco’s modified eagle’s medium Nutrient mixture F12 (DMEM/F12 medium with 17.5 mM glucose supplemented by 10 mM nicotinamide, 10 nM exendin-4, 10 nM pentagastrin, 100 pM hepatocyte growth factor, and B-27 serum-free supplement. After differentiation, insulin content was analyzed by gene expression, immunocytochemistry (IHC and the chemiluminesence immunoassay (CLIA. Results: Reverse transcription-polymerase chain reaction (RT-PCR showed efficient expressions of NKX2.2, PDX1 and INSULIN genes in both groups. IHC analysis showed higher expression of insulin protein in the hanging drop group, and CLIA revealed a significant higher insulin production in hanging drops compared with the monolayer group following the glucose challenge test. Conclusion: We showed by this novel, simple technique that the suspension culture played an important role in differentiation of hUCMs into IPC. This culture was more efficient than the conventional culture method commonly used in IPC differentiation and cultivation.

  3. Root maturation and dentin-pulp response to enamel matrix derivative in pulpotomized permanent teeth.

    Science.gov (United States)

    Darwish, Sherif S; Abd El Meguid, Shadia H; Wahba, Nadia A; Mohamed, Ahmed A-R; Chrzanowski, Wojciech; Abou Neel, Ensanya A

    2014-01-01

    The success of pulpotomy of young permanent teeth depends on the proper selection of dressing materials. This study aimed to evaluate the histological and histomorphometric response of dentin-pulp complex to the enamel matrix derivative (Emdogain(®) gel) compared to that of calcium hydroxide when used as a pulp dressing in immature young permanent dogs' teeth. Dentin-like tissues bridging the full width of the coronal pulp at the interface between the injured and healthy pulp tissues were seen after 1 month in both groups. With time, the dentin bridge increased in thickness for calcium hydroxide but disintegrated and fully disappeared for Emdogain-treated group. Progressive inflammation and total pulp degeneration were only evident with Emdogain-treated group. The root apices of Emdogain-treated teeth became matured and closed by cementum that attached to new alveolar bone by a well-oriented periodontal ligament. In young permanent dentition, Emdogain could be a good candidate for periodontium but not dentino-pulpal complex regeneration.

  4. Biocompatibility of pure titanium modified by human endothelial cell-derived extracellular matrix

    Energy Technology Data Exchange (ETDEWEB)

    Xue Xiaoqing [Key Laboratory of Advanced Technology for Materials of Education Ministry, Southwest Jiaotong University, Chengdu 610031 (China); Wang Jin, E-mail: jinxxwang@263.net [Key Laboratory of Advanced Technology for Materials of Education Ministry, Southwest Jiaotong University, Chengdu 610031 (China); Zhu Ying; Tu Qiufen; Huang Nan [Key Laboratory of Advanced Technology for Materials of Education Ministry, Southwest Jiaotong University, Chengdu 610031 (China)

    2010-04-01

    Extracellular matrix (ECM) used to modify biomaterial surface is a promising method for improving cardiovascular material hemocompatibility. In the present work, human umbilical vein endothelial cells (HUVECs) are cultured and native ECM is obtained on pure titanium surface. Fourier infrared spectrum (FTIR) test proves the existence of amide I and amide II band on the modified titanium surface. X-ray photoelectron spectroscopy (XPS) further confirms the chemical composition and binding types of the ECM proteins on the titanium substrate. The results of light microscopy and atomic force microscopy (AFM) exhibit the morphology of HUVEC derived ECM. There are higher water contact angles on the ECM modified samples. Furthermore, some ECM components, including fibronectin (FN), laminin (LN) and type IV collagen (IV-COL) are presented on ECM-covered titanium surface by immunofluorescence staining. The biological behavior of cultured HUVECs and adherent platelets on different samples are investigated by in vitro HUVECs culture and platelet adhesion. Cells exhibit better morphology and their proliferation ability greatly improve on the ECM-covered titanium. At the same time, the platelet adhesion and spreading are inhibited on ECM-covered titanium surface. These investigations demonstrate that ECM produced by HUVECs cannot only improve adhesion and proliferation ability of endothelial cell but also inhibit adhesion and activation of platelets. Thus, the approach described here may provide a basis for preparation of modified surface in cardiovascular implants application.

  5. Effect of enamel matrix derivative (Emdogain) on bone defects in rabbit tibias.

    Science.gov (United States)

    Cornelini, Roberto; Scarano, Antonio; Piattelli, Maurizio; Andreana, Sebastiano; Covani, Ugo; Quaranta, Alessandro; Piattelli, Adriano

    2004-01-01

    The aim of this study was to assess the effect of an enamel matrix derivative (Emdogain, Biora, AB, Malmö, Sweden) on bone healing. Ten New Zealand rabbits, weighing about 2.5 kg, were used. One 8-mm bone defect was created in each tibia. The defect on the right leg was filled with Emdogain, whereas the defect on the opposite leg was left unfilled as control. A total of 20 defects were created. Five rabbits each were killed at 4 and 8 weeks with an overdose of Tanax. Block sections containing the defects were retrieved and the specimens processed for light microscopy examination. The slides were stained with acid and basic fuchsin and toluidine blue. Histologically, no differences were noted in both groups at each observation period; in the test group, remnants of the implanted Emdogain were not present at 4 weeks. Newly formed bone was detectable in both groups at all observation times. At 8 weeks, both groups showed mature bone, and in the test group the material implanted was not visible. No inflammatory cells were visible in both groups. In conclusion, our results indicate that Emdogain implanted in bone defects is fully resorbed after 4 to 8 weeks and does not adversely affect bone formation.

  6. Root maturation and dentin–pulp response to enamel matrix derivative in pulpotomized permanent teeth

    Directory of Open Access Journals (Sweden)

    Sherif S Darwish

    2014-01-01

    Full Text Available The success of pulpotomy of young permanent teeth depends on the proper selection of dressing materials. This study aimed to evaluate the histological and histomorphometric response of dentin–pulp complex to the enamel matrix derivative (Emdogain® gel compared to that of calcium hydroxide when used as a pulp dressing in immature young permanent dogs’ teeth. Dentin-like tissues bridging the full width of the coronal pulp at the interface between the injured and healthy pulp tissues were seen after 1 month in both groups. With time, the dentin bridge increased in thickness for calcium hydroxide but disintegrated and fully disappeared for Emdogain-treated group. Progressive inflammation and total pulp degeneration were only evident with Emdogain-treated group. The root apices of Emdogain-treated teeth became matured and closed by cementum that attached to new alveolar bone by a well-oriented periodontal ligament. In young permanent dentition, Emdogain could be a good candidate for periodontium but not dentino–pulpal complex regeneration.

  7. Process Extension from Embryonic Stem Cell-Derived Motor Neurons through Synthetic Extracellular Matrix Mimics

    Science.gov (United States)

    McKinnon, Daniel Devaud

    This thesis focuses on studying the extension of motor axons through synthetic poly(ethylene glycol) PEG hydrogels that have been modified with biochemical functionalities to render them more biologically relevant. Specifically, the research strategy is to encapsulate embryonic stem cell-derived motor neurons (ESMNs) in synthetic PEG hydrogels crosslinked through three different chemistries providing three mechanisms for dynamically tuning material properties. First, a covalently crosslinked, enzymatically degradable hydrogel is developed and exploited to study the biophysical dynamics of axon extension and matrix remodeling. It is demonstrated that dispersed motor neurons require a battery of adhesive peptides and growth factors to maintain viability and extend axons while those in contact with supportive neuroglial cells do not. Additionally, cell-degradable crosslinker peptides and a soft modulus mimicking that of the spinal cord are requirements for axon extension. However, because local degradation of the hydrogel results in a cellular environment significantly different than that of the bulk, enzymatically degradable peptide crosslinkers were replaced with reversible covalent hydrazone bonds to study the effect of hydrogel modulus on axon extension. This material is characterized in detail and used to measure forces involved in axon extension. Finally, a hydrogel with photocleavable linkers incorporated into the network structure is exploited to explore motor axon response to physical channels. This system is used to direct the growth of motor axons towards co-cultured myotubes, resulting in the formation of an in vitro neural circuit.

  8. Nitric oxide regulates cell behavior on an interactive cell-derived extracellular matrix scaffold.

    Science.gov (United States)

    Xing, Qi; Zhang, Lijun; Redman, Travis; Qi, Shaohai; Zhao, Feng

    2015-12-01

    During tissue injury and wound healing process, there are dynamic reciprocal interactions among cells, extracellular matrix (ECM), and mediating molecules which are crucial for functional tissue repair. Nitric oxide (NO) is one of the key mediating molecules that can positively regulate various biological activities involved in wound healing. Various ECM components serve as binding sites for cells and mediating molecules, and the interactions further stimulate cellular activities. Human mesenchymal stem cells (hMSCs) can migrate to the wound site and contribute to tissue regeneration through differentiation and paracrine signaling. The objective of this work was to investigate the regulatory effect of NO on hMSCs in an interactive ECM-rich microenvironment. In order to mimic the in vivo stromal environment in wound site, a cell-derived ECM scaffold that was able to release NO within the range of in vivo wound fluid NO level was fabricated. Results showed that the micro-molar level of NO released from the ECM scaffold had an inhibitory effect on cellular activities of hMSCs. The NO impaired cell growth, altered cell morphology, disrupted the F-actin organization, also decreased the expression of focal adhesion related molecules integrin α5 and paxillin. These results may contribute to the elucidation of how NO acts on hMSCs in wound healing process.

  9. Amine functionalization of cholecyst-derived extracellular matrix with generation 1 PAMAM dendrimer.

    LENUS (Irish Health Repository)

    Chan, Jeffrey C Y

    2008-02-01

    A method to functionalize cholecyst-derived extracellular matrix (CEM) with free amine groups was established in an attempt to improve its potential for tethering of bioactive molecules. CEM was incorporated with Generation-1 polyamidoamine (G1 PAMAM) dendrimer by using N-(3-dimethylaminopropyl)-N\\'-ethylcarbodiimide and N-hydroxysuccinimide cross-linking system. The nature of incorporation of PAMAM dendrimer was evaluated using shrink temperature measurements, Fourier transform infrared (FTIR) assessment, ninhydrin assay, and swellability. The effects of PAMAM incorporation on mechanical and degradation properties of CEM were evaluated using a uniaxial mechanical test and collagenase degradation assay, respectively. Ninhydrin assay and FTIR assessment confirmed the presence of increasing free amine groups with increasing quantity of PAMAM in dendrimer-incorporated CEM (DENCEM) scaffolds. The amount of dendrimer used was found to be critical in controlling scaffold degradation, shrink temperature, and free amine content. Cell culture studies showed that fibroblasts seeded on DENCEM maintained their metabolic activity and ability to proliferate in vitro. In addition, fluorescence cell staining and scanning electron microscopy analysis of cell-seeded DENCEM showed preservation of normal fibroblast morphology and phenotype.

  10. Influence of porcine-derived collagen matrix on endothelial progenitor cells: an in vitro study.

    Science.gov (United States)

    Pabst, Andreas Max; Lehmann, Karl-Martin; Walter, Christian; Krüger, Maximilian; Stratul, Stefan-Ioan; Kasaj, Adrian

    2016-01-01

    Porcine-derived collagen matrix (PDCM) has been reported as a promising alternative to autogenous soft tissue grafts in periodontal plastic surgery. The aim of this study was to analyze the influence of a novel PDCM on endothelial progenitor cells (EPC) in vitro. EPC were isolated from human peripheral blood, cultured and transferred on the PDCM (mucoderm®). Tissue culture polystyrene surface (TCPS) served as control. Cell viability of EPC on PDCM was measured by a MTT and PrestoBlue® assay. Migration ability was tested using a Boyden migration assay. A ToxiLight® assay was performed to analyze the influence of PDCM on adenylate kinase (ADK) release and apoptosis rate of EPC. Using the MTT assay, EPC cultured on PDCM demonstrated a significantly increased cell viability compared to the control group at days 3, 6 and 12 (p each 0.05). Overall, our results suggest a good biocompatibility of PDCM without any cytotoxic effects on EPC, which might support a rapid revascularization and therefore a sufficient ingrowth of the PDCM.

  11. A hybrid approach EMD-HW for short-term forecasting of daily stock market time series data

    Science.gov (United States)

    Awajan, Ahmad Mohd; Ismail, Mohd Tahir

    2017-08-01

    Recently, forecasting time series has attracted considerable attention in the field of analyzing financial time series data, specifically within the stock market index. Moreover, stock market forecasting is a challenging area of financial time-series forecasting. In this study, a hybrid methodology between Empirical Mode Decomposition with the Holt-Winter method (EMD-HW) is used to improve forecasting performances in financial time series. The strength of this EMD-HW lies in its ability to forecast non-stationary and non-linear time series without a need to use any transformation method. Moreover, EMD-HW has a relatively high accuracy and offers a new forecasting method in time series. The daily stock market time series data of 11 countries is applied to show the forecasting performance of the proposed EMD-HW. Based on the three forecast accuracy measures, the results indicate that EMD-HW forecasting performance is superior to traditional Holt-Winter forecasting method.

  12. A New Derivation of the Time-Dependent Schr\\"odinger Equation from Wave and Matrix Mechanics

    CERN Document Server

    Nanni, Luca

    2015-01-01

    An alternative method is proposed for deriving the time dependent Schroedinger equation from the pictures of wave and matrix mechanics. The derivation is of a mixed classical quantum character, since time is treated as a classical variable, thus avoiding any controversy over its meaning in quantum mechanics. The derivation method proposed in this paper requires no ad hoc assumption and avoids going through a second-order differential equation that can be reduced to the well known time-dependent Schroedinger equation only postulating a complex wavefunction with an exponential time dependence, as did by Schroedinger in its original paper of 1926.

  13. Generalized Derivations of Formal Triangular Matrix Rings%形式三角矩阵环的广义导子

    Institute of Scientific and Technical Information of China (English)

    谢乐平

    2011-01-01

    利用代数方法,得到了形式三角矩阵环Tri(A,M,B)的广义导子可以由环A,B的广义导子和(A,B)-双模M的广义拟线性映射表示的结论,同时由此结论推得形式三角矩阵环Tri(A,M,B)的导子的结构.%Generalized derivations of the formal triangular matrix ring Tri(A, M, B) are obtained by generalized derivations of A,B and a generalized fitting-linear mapping of M by using algebraic method. Using this result, the structure form of the derivations of the formal triangular'matrix ring Tri(A, M, B) is obtained.

  14. 基于 EMD-Hankel-SVD 的高速列车万向轴动不平衡检测%Detection of dynamic imbalance due to cardan shaft in high-speed train based on EMD-Hankel-SVD method

    Institute of Scientific and Technical Information of China (English)

    丁建明; 王晗; 林建辉; 黄晨光

    2015-01-01

    针对EMD(Empirical Model Decomposition)存在模式频率混叠带来的频谱杂乱的根本缺陷,提出一种高速列车万向轴动不平衡动态检测的新方法。该方法的核心是:对万向节安装机座的振动信号进行 EMD 分解得到基本模式分量,应用基本模式分量信号来构造 Hankel 矩阵,对该矩阵进行奇异值正交化分解,以奇异值关键叠层作为奇异值的选择准则对信号进行重构,应用重构信号的傅里叶谱来检测高速列车万向轴的动不平衡,消除 EMD 分解模式频率混叠带来频谱杂乱,提高了谱的清晰度,凸显了故障特征。应用万向轴动不平衡试验数据对该方法进行试验验证,结果表明:该方法能够有效检测万向轴动不平衡引起故障特征和万向轴的固有振动特性,与纯 EMD 方法相比,该方法在谱的清晰度和故障表征力上得到了显著提高。%A new method of detecting dynamic imbalance due to cardan shaft in high-speed train was proposed applying a synthesized method of EMD (Empirical Modal Decomposition),Hankel matrix and SVD (singular value decomposition)against the aliasing defect between adjacent intrinsic model functions existing in EMD.The vibration signals of gimbal installed base were decomposed through EMD to get the different intrinsic model components.The Hankel matrix,constructed of the single decomposition model components,was orthogonally decomposed through SVD and the key singular values were selected to reconstruct the vibration signal on the base of the key stack of singular values.The Fourier spectrum of the reconstructed signal was applied to detect dynamic imbalance of shaft and the clutter spectrum caused by the aliasing defect between adjacent intrinsic model functions was eliminated so as to highlight the failure characteristics.The method was verified by test data in the condition of dynamic imbalance.The results show the method can effectively detect the

  15. Intervertebral Disc Tissue Engineering with Natural Extracellular Matrix-Derived Biphasic Composite Scaffolds.

    Directory of Open Access Journals (Sweden)

    Baoshan Xu

    Full Text Available Tissue engineering has provided an alternative therapeutic possibility for degenerative disc diseases. However, we lack an ideal scaffold for IVD tissue engineering. The goal of this study is to fabricate a novel biomimetic biphasic scaffold for IVD tissue engineering and evaluate the feasibility of developing tissue-engineered IVD in vitro and in vivo. In present study we developed a novel integrated biphasic IVD scaffold using a simple freeze-drying and cross-linking technique of pig bone matrix gelatin (BMG for the outer annulus fibrosus (AF phase and pig acellular cartilage ECM (ACECM for the inner nucleus pulposus (NP phase. Histology and SEM results indicated no residual cells remaining in the scaffold that featured an interconnected porous microstructure (pore size of AF and NP phase 401.4 ± 13.1 μm and 231.6 ± 57.2 μm, respectively. PKH26-labeled AF and NP cells were seeded into the scaffold and cultured in vitro. SEM confirmed that seeded cells could anchor onto the scaffold. Live/dead staining showed that live cells (green fluorescence were distributed in the scaffold, with no dead cells (red fluorescence being found. The cell-scaffold constructs were implanted subcutaneously into nude mice and cultured for 6 weeks in vivo. IVD-like tissue formed in nude mice as confirmed by histology. Cells in hybrid constructs originated from PKH26-labeled cells, as confirmed by in vivo fluorescence imaging system. In conclusion, the study demonstrates the feasibility of developing a tissue-engineered IVD in vivo with a BMG- and ACECM-derived integrated AF-NP biphasic scaffold. As well, PKH26 fluorescent labeling with in vivo fluorescent imaging can be used to track cells and analyse cell--scaffold constructs in vivo.

  16. Application of UVA-riboflavin crosslinking to enhance the mechanical properties of extracellular matrix derived hydrogels.

    Science.gov (United States)

    Ahearne, Mark; Coyle, Aron

    2016-02-01

    Hydrogels derived from extracellular matrix (ECM) have become increasing popular in recent years, particularly for use in tissue engineering. One limitation with ECM hydrogels is that they tend to have poor mechanical properties compared to native tissues they are trying to replicate. To address this problem, a UVA (ultraviolet-A) riboflavin crosslinking technique was applied to ECM hydrogels to determine if it could be used to improve their elastic modulus. Hydrogels fabricated from corneal, cardiac and liver ECM were used in this study. The mechanical properties of the hydrogels were characterized using a spherical indentation technique. The microstructure of the hydrogels and the cytotoxic effect of crosslinking on cell seeded hydrogels were also evaluated. The combination of UVA light and riboflavin solution led to a significant increase in elastic modulus from 6.8kPa to 24.7kPa, 1.4kPa to 6.9kPa and 0.9kPa to 1.6kPa for corneal, cardiac and liver ECM hydrogels respectively. The extent of this increase was dependent on a number of factors including the UVA exposure time and the initial hydrogel concentration. There were also a high percentage of viable cells within the cell seeded hydrogels with 94% of cells remaining viable after 90min exposure to UVA light. These results suggest that UVA-riboflavin crosslinking is an effective approach for improving the mechanical properties of ECM hydrogels without resulting in a significant reduction of cell viability.

  17. Vitamin D decreases the secretion of matrix metalloproteinase-2 and matrix metalloproteinase-9 in fibroblasts derived from Taiwanese patients with chronic rhinosinusitis with nasal polyposis.

    Science.gov (United States)

    Wang, Ling-Feng; Tai, Chih-Feng; Chien, Chen-Yu; Chiang, Feng-Yu; Chen, Jeff Yi-Fu

    2015-05-01

    Vitamin D and its derivatives have modulatory effects in immunological and inflammatory responses. Such properties suggest that they might have an impact on chronic inflammatory airway diseases, including nasal polyposis. The aim of this study was to understand the role of vitamin D in chronic rhinosinusitis with nasal polyps (CRSwNP) by investigating its effect on the secretion of matrix metalloproteinase-2 (MMP-2) and MMP-9 in nasal polyp-derived fibroblasts. Two primary fibroblast cultures were established from nasal polyp tissues obtained during surgery. The nasal polyp-derived fibroblasts were stimulated with tumor necrosis factor-α (TNF-α; 10 ng/mL) for 24 hours, followed by replacement with media alone or with vitamin D derivatives (calcitriol or tacalcitol; 10μM) and incubated for another 24 hours. After the treatments, the levels of MMP-2 and MMP-9 secreted were evaluated by both enzyme-linked immunosorbent assay (ELISA) and Western blot analysis. ELISA results revealed that TNF-α could substantially stimulate the secretion of MMP-2 (p MMP-2 and p MMP-2 and MMP-9). The ELISA results were also confirmed by Western blot analysis. The inhibitory effect of vitamin D derivatives on MMP-2 and MMP-9 secretion could potentiate their application in pharmacotherapy of Taiwanese CRSwNP patients.

  18. Efficient EMD-based Similarity Search in Multimedia Databases via Flexible Dimensionality Reduction

    DEFF Research Database (Denmark)

    Wichterich, Marc; Assent, Ira; Philipp, Kranen

    2008-01-01

    The Earth Mover's Distance (EMD) was developed in computer vision as a flexible similarity model that utilizes similarities in feature space to define a high quality similarity measure in feature representation space. It has been successfully adopted in a multitude of applications with low to med...

  19. 75 FR 17939 - EMD Chemicals, Inc.; Withdrawal of Color Additive Petition

    Science.gov (United States)

    2010-04-08

    ... pigments prepared from combinations of synthetic iron oxide, titanium dioxide, and mica to color food. FDA... HUMAN SERVICES Food and Drug Administration (formerly Docket No. 1998C-0790) EMD Chemicals, Inc.; Withdrawal of Color Additive Petition AGENCY: Food and Drug Administration, HHS. ACTION: Notice. SUMMARY:...

  20. Fishery landing forecasting using EMD-based least square support vector machine models

    Science.gov (United States)

    Shabri, Ani

    2015-05-01

    In this paper, the novel hybrid ensemble learning paradigm integrating ensemble empirical mode decomposition (EMD) and least square support machine (LSSVM) is proposed to improve the accuracy of fishery landing forecasting. This hybrid is formulated specifically to address in modeling fishery landing, which has high nonlinear, non-stationary and seasonality time series which can hardly be properly modelled and accurately forecasted by traditional statistical models. In the hybrid model, EMD is used to decompose original data into a finite and often small number of sub-series. The each sub-series is modeled and forecasted by a LSSVM model. Finally the forecast of fishery landing is obtained by aggregating all forecasting results of sub-series. To assess the effectiveness and predictability of EMD-LSSVM, monthly fishery landing record data from East Johor of Peninsular Malaysia, have been used as a case study. The result shows that proposed model yield better forecasts than Autoregressive Integrated Moving Average (ARIMA), LSSVM and EMD-ARIMA models on several criteria..

  1. Using the EMD method to determine fault criterion for medium-low pressure gas regulators

    Science.gov (United States)

    Hao, Xuejun; Liu, Qiang; Yang, Guobin; Du, Yi

    2015-11-01

    By extracting the outlet pressure data of gas regulators, this paper uses the EMD toolbox of the MATLAB software, which can perform data decomposition and the Hilbert-Huang Transform to find the rules with fault data. Eventually, the medium-low pressure gas regulator fault criterion can be established.

  2. Friction Signal Denoising Using Complete Ensemble EMD with Adaptive Noise and Mutual Information

    Directory of Open Access Journals (Sweden)

    Chengwei Li

    2015-08-01

    Full Text Available During the measurement of friction force, the measured signal generally contains noise. To remove the noise and preserve the important features of the signal, a hybrid filtering method is introduced that uses the mutual information and a new waveform. This new waveform is the difference between the original signal and the sum of intrinsic mode functions (IMFs, which are obtained by empirical mode decomposition (EMD or its improved versions. To evaluate the filter performance for the friction signal, ensemble EMD (EEMD, complementary ensemble EMD (CEEMD, and complete ensemble EMD with adaptive noise (CEEMDAN are employed in combination with the proposed filtering method. The combination is used to filter the synthesizing signals at first. For the filtering of the simulation signal, the filtering effect is compared under conditions of different ensemble number, sampling frequency, and the input signal-noise ratio, respectively. Results show that CEEMDAN outperforms other signal filtering methods. In particular, this method is successful in filtering the friction signal as evaluated by the de-trended fluctuation analysis (DFA algorithm.

  3. Mean-field Approach to the Derivation of Baryon Superpotential from Matrix Model

    CERN Document Server

    Suzuki, H

    2003-01-01

    We discuss how to obtain the superpotential of the baryons and mesons for SU(N) gauge theories with N flavour matter fields from matrix integral. We apply the mean-field approximation for the matrix integral. Assuming the planar limit of the self-consistency equation, we show that the result almost agrees with the field theoretical result.

  4. Elasticity Modulation of Fibroblast-Derived Matrix for Endothelial Cell Vascular Morphogenesis and Mesenchymal Stem Cell Differentiation.

    Science.gov (United States)

    Du, Ping; Suhaeri, Muhammad; Subbiah, Ramesh; Van, Se Young; Park, Jimin; Kim, Sang Heon; Park, Kwideok; Lee, Kangwon

    2016-03-01

    Biophysical properties of the microenvironment, including matrix elasticity and topography, are known to affect various cell behaviors; however, the specific role of each factor is unclear. In this study, fibroblast-derived matrix (FDM) was used as cell culture substrate and physically modified to investigate the influence of its biophysical property changes on human umbilical vein endothelial cells (HUVECs) and human mesenchymal stem cells (hMSCs) behavior in vitro. These FDMs were physically modified by simply storing them at different temperatures: the one stored at 4°C, maintained its original properties, was considered natural FDM, whereas the ones stored at -20°C or -80°C, exhibited a distinct surface morphology, were considered physically modified FDM. Physical modification induced matrix fiber rearrangement in FDM, forming different microstructures on the surface as characterized by focused ion beam (FIB)-cryoSEM. A significant increase of matrix elasticity was found with physically modified FDMs as determined by atomic force microscopy. HUVEC and hMSC behaviors on these natural and physically modified FDMs were observed and compared with each other and with gelatin-coated coverslips. HUVECs showed a similar adhesion level on these substrates at 3 h, but exhibited different proliferation rates and morphologies at 24 h; HUVECs on natural FDM proliferated relatively slower and assembled to capillary-like structures (CLSs). It is observed that HUVECs assembled to CLSs on natural FDMs are independent on the exogenous growth factors and yet dependent on nonmuscle myosin II activity. This result indicates the important role of matrix mechanical properties in regulating HUVECs vascular morphogenesis. As for hMSCs multilineage differentiation, adipogenesis is improved on natural FDM that with lower matrix elasticity, while osteogenesis is accelerated on physically modified FDMs that with higher matrix elasticity, these results further confirm the crucial

  5. Chondrogenic differentiation of adipose-derived stromal cells in combinatorial hydrogels containing cartilage matrix proteins with decoupled mechanical stiffness.

    Science.gov (United States)

    Wang, Tianyi; Lai, Janice H; Han, Li-Hsin; Tong, Xinming; Yang, Fan

    2014-08-01

    Adipose-derived stromal cells (ADSCs) are attractive autologous cell sources for cartilage repair given their relative abundance and ease of isolation. Previous studies have demonstrated the potential of extracellular matrix (ECM) molecules as three-dimensional (3D) scaffolds for promoting chondrogenesis. However, few studies have compared the effects of varying types or doses of ECM molecules on chondrogenesis of ADSCs in 3D. Furthermore, increasing ECM molecule concentrations often result in simultaneous changes in the matrix stiffness, which makes it difficult to elucidate the relative contribution of biochemical cues or matrix stiffness on stem cell fate. Here we report the development of an ECM-containing hydrogel platform with largely decoupled biochemical and mechanical cues by modulating the degree of methacrylation of ECM molecules. Specifically, we incorporated three types of ECM molecules that are commonly found in the cartilage matrix, including chondroitin sulfate (CS), hyaluronic acid (HA), and heparan sulfate (HS). To elucidate the effects of interactive biochemical and mechanical signaling on chondrogenesis, ADSCs were encapsulated in 39 combinatorial hydrogel compositions with independently tunable ECM types (CS, HA, and HS), concentrations (0.5%, 1.25%, 2.5%, and 5% [w/v]), and matrix stiffness (3, 30, and 90 kPa). Our results show that the effect of ECM composition on chondrogenesis is dependent on the matrix stiffness of hydrogels, suggesting that matrix stiffness and biochemical cues interact in a nonlinear manner to regulate chondrogenesis of ADSCs in 3D. In soft hydrogels (~3 kPa), increasing HA concentrations resulted in substantial upregulation of aggrecan and collagen type II expression in a dose-dependent manner. This trend was reversed in HA-containing hydrogels with higher stiffness (~90 kPa). The platform reported herein could provide a useful tool for elucidating how ECM biochemical cues and matrix stiffness interact together to

  6. Specific D-Admissibility and Design Issues for Uncertain Descriptor Systems with Parametric Uncertainty in the Derivative Matrix

    Directory of Open Access Journals (Sweden)

    Chih-Peng Huang

    2016-01-01

    Full Text Available Stability analysis issues and controller synthesis for descriptor systems with parametric uncertainty in the derivative matrix are discussed in this paper. The proposed descriptor system can extend the system’s modeling extent of physical and engineering systems from the traditional state-space model. First, based on the extended D-stability definitions for the descriptor model, necessary and sufficient admissibility and D-admissibility conditions for the unforced nominal descriptor system are derived and formulated by compact forms with strict linear matrix inequality (LMI manner. In contrast, existing results need to involve nonstrict LMIs, which cannot be evaluated by current LMI solvers and need some extra treatments. Deducing from the obtained distinct results, the roust admissibility and D-admissibility of the descriptor system with uncertainties in both the derivative matrix and the system’s matrices thus can be coped. Furthermore, by involving a proportional and derivative state feedback (PDSF control law, we further address the controller design for the resulting closed-loop systems. Since all the proposed criteria are explicitly expressed in terms of the strict LMIs, we can use applicable LMI solvers for evaluating the feasible solutions. Finally, the efficiency and practicability of the proposed approach are demonstrated by two illustrative examples.

  7. PET image reconstruction with system matrix based on point spread function derived from single photon incidence response

    CERN Document Server

    Xin, Fan; Ming-Kai, Yun; Xiao-Li, Sun; Xue-Xiang, Cao; Shuang-Quanm, Liu; Pei, Chai; Dao-Wu, Li; Long, Wei

    2014-01-01

    In positron emission tomography (PET) imaging, statistical iterative reconstruction (IR) techniques appear particularly promising since they can provide accurate physical model and geometric system description. The reconstructed image quality mainly depends on the system matrix model which describes the relationship between image space and projection space for the IR method. The system matrix can contain some physics factors of detection such as geometrical component and blurring component. Point spread function (PSF) is generally used to describe the blurring component. This paper proposes an IR method based on the PSF system matrix, which is derived from the single photon incidence response function. More specifically, the gamma photon incidence on a crystal array is simulated by the Monte Carlo (MC) simulation, and then the single photon incidence response functions are obtained. Subsequently, using the single photon incidence response functions, the coincidence blurring factor is acquired according to the...

  8. Brain-derived neurotrophic factor inducing angiogenesis through modulation of matrix-degrading proteases

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Background Recent studies have proved that brain-derived neurotrophic factor (BDNF) possesses angiogenic activity in vitro and in vivo. However, the proangiogenic mechanism of BDNF has not yet been provided with enough information. To explore the proangiogenic mechanism of BDNF, we investigated the effects of BDNF on extracellular proteolytic enzymes, including matrix metalloproteinases (MMPs) and serine proteases, particularly the urokinase-type plasminogen activator (uPA)-plasmin system in human umbilical vein endothelial cells (HUVECs) model. Methods Tube formation assay was performed in vitro to evaluate the effects of BDNF on angiogenesis. The HUVECs were treated with various concentrations of BDNF (25-400 ng/ml) for different (6-48 hours), reverse transcriptase-polymerase chain reaction (RT-PCR) was used to assay MMP-2, MMP-9, TIMP-1, and TIMP-2 mRNA in HUVECs, and the conditioned medium was analyzed for MMP and uPA activity by gelatin zymography and fibrin zymography, respectively. uPA, plasminogen activator inhibitor (PAI)-1, tissue inhibitors of metalloproteinase (TIMP)-1, and TIMP-2 were quantified by western blotting analysis. Results BDNF elicited robust and elongated angiogeneis in two-dimensional cultures of HUVECs in comparison with control. The stimulation of serum-starved HUVECs with BDNF caused obvious increase in MMP-2 and MMP-9 mRNA expression and induced the pro-MMP-2 and pro-MMP-9 activation without significant differences in proliferation. However, BDNF had no effect on TIMP-1 and TIMP-2 production. BDNF increased uPA and PAI-1 production in a dose-dependent manner. Maximal activation of uPA and PAI-1 expression in HUVECs was induced by 100 ng/ml BDNF, while effects of 200 ng/ml and 400 ng/ml BDNF were slightly reduced in comparison with with those of 100 ng/ml. Protease activity for uPA was also increased by BDNF in a dose-dependent manner. BDNF also stimulated uPA and PAI-1 production beyond that in control cultures in a time

  9. Polymer-Derived In- Situ Metal Matrix Composites Created by Direct Injection of a Liquid Polymer into Molten Magnesium

    Science.gov (United States)

    Sudarshan; Terauds, Kalvis; Anilchandra, A. R.; Raj, Rishi

    2014-02-01

    We show that a liquid organic precursor can be injected directly into molten magnesium to produce nanoscale ceramic dispersions within the melt. The castings made in this way possess good resistance to tensile deformation at 673 K (400 °C), confirming the non-coarsening nature of these dispersions. Direct liquid injection into molten metals is a significant step toward inserting different chemistries of liquid precursors to generate a variety of polymer-derived metal matrix composites.

  10. Matrix-derived combination effect and risk assessment for estragole from basil-containing plant food supplements (PFS).

    Science.gov (United States)

    van den Berg, Suzanne J P L; Klaus, Verena; Alhusainy, Wasma; Rietjens, Ivonne M C M

    2013-12-01

    Basil-containing plant food supplements (PFS) can contain estragole which can be metabolised into a genotoxic and carcinogenic 1'-sulfoxymetabolite. This study describes the inhibition of sulfotransferase (SULT)-mediated bioactivation of estragole by compounds present in basil-containing PFS. Results reveal that PFS consisting of powdered basil material contain other compounds with considerable in vitro SULT-inhibiting activity, whereas the presence of such compounds in PFS consisting of basil essential oil was limited. The inhibitor in powdered basil PFS was identified as nevadensin. Physiologically based kinetic (PBK) modeling was performed to elucidate if the observed inhibitory effects can occur in vivo. Subsequently, risk assessment was performed using the Margin of Exposure (MOE) approach. Results suggest that the consequences of the in vivo matrix-derived combination effect are significant when estragole would be tested in rodent bioassays with nevadensin at ratios detected in PFS, thereby increasing MOE values. However, matrix-derived combination effects may be limited at lower dose levels, indicating that the importance of matrix-derived combination effects for risk assessment of individual compounds should be done on a case-by-case basis considering dose-dependent effects. Furthermore, this study illustrates how PBK modeling can be used in risk assessment of PFS, contributing to further reduction in the use of experimental animals.

  11. Extracellular Matrix Hydrogel Derived from Human Umbilical Cord as a Scaffold for Neural Tissue Repair and Its Comparison with Extracellular Matrix from Porcine Tissues.

    Science.gov (United States)

    Kočí, Zuzana; Výborný, Karel; Dubišová, Jana; Vacková, Irena; Jäger, Aleš; Lunov, Oleg; Jiráková, Klára; Kubinová, Šárka

    2017-06-01

    Extracellular matrix (ECM) hydrogels prepared by tissue decellularization have been reported as natural injectable materials suitable for neural tissue repair. In this study, we prepared ECM hydrogel derived from human umbilical cord (UC) and evaluated its composition and mechanical and biological properties in comparison with the previously described ECM hydrogels derived from porcine urinary bladder (UB), brain, and spinal cord. The ECM hydrogels did not differ from each other in the concentration of collagen, while the highest content of glycosaminoglycans as well as the shortest gelation time was found for UC-ECM. The elastic modulus was then found to be the highest for UB-ECM. In spite of a different origin, topography, and composition, all ECM hydrogels similarly promoted the migration of human mesenchymal stem cells (MSCs) and differentiation of neural stem cells, as well as axonal outgrowth in vitro. However, only UC-ECM significantly improved proliferation of tissue-specific UC-derived MSCs when compared with the other ECMs. Injection of UC-ECM hydrogels into a photothrombotic cortical ischemic lesion in rats proved its in vivo gelation and infiltration with host macrophages. In summary, this study proposes UC-ECM hydrogel as an easily accessible biomaterial of human origin, which has the potential for neural as well as other soft tissue reconstruction.

  12. 基于EMD-SVD-BIC的机械振动源数估计方法%Mechanical Vibration Source Number Estimation Based on EMD-SVD-BIC

    Institute of Scientific and Technical Information of China (English)

    叶红仙; 杨世锡; 杨将新

    2010-01-01

    提出了一种复合EMD-SVD-BIC(经验模态分解,empirical mode decomposition,简称EMD;奇异值分解,singular value decomposition,简称SVD;贝叶斯信息准则,bayesian information criterion,简称BIC)的机械振动源信号数量估计方法,解决卷积混合的机械振动源在观测数小于振动源数情况下的源数估计问题.应用EMD方法获得信号的本征模函数,对两观测信号的本征模函数复合矩阵的相关矩阵进行奇异值分解,获得反映源数信息的特征值分布;再采用BIC信息准则,判断源信号的数目.仿真和试验结果表明,该方法可以在观测数小于振动源数的情况下正确获取信号源数,为机械振动故障诊断中的振动源分析及其源信号的正确分离提供了方法保障.

  13. EMD-Based Symbolic Dynamic Analysis for the Recognition of Human and Nonhuman Pyroelectric Infrared Signals

    Directory of Open Access Journals (Sweden)

    Jiaduo Zhao

    2016-01-01

    Full Text Available In this paper, we propose an effective human and nonhuman pyroelectric infrared (PIR signal recognition method to reduce PIR detector false alarms. First, using the mathematical model of the PIR detector, we analyze the physical characteristics of the human and nonhuman PIR signals; second, based on the analysis results, we propose an empirical mode decomposition (EMD-based symbolic dynamic analysis method for the recognition of human and nonhuman PIR signals. In the proposed method, first, we extract the detailed features of a PIR signal into five symbol sequences using an EMD-based symbolization method, then, we generate five feature descriptors for each PIR signal through constructing five probabilistic finite state automata with the symbol sequences. Finally, we use a weighted voting classification strategy to classify the PIR signals with their feature descriptors. Comparative experiments show that the proposed method can effectively classify the human and nonhuman PIR signals and reduce PIR detector’s false alarms.

  14. EMD and Wavelet Transform Based Fault Diagnosis for Wind Turbine Gear Box

    Directory of Open Access Journals (Sweden)

    Qingyu Yang

    2013-01-01

    Full Text Available Wind turbines are mainly located in harsh environment, and the maintenance is therefore very difficult. The wind turbine faults are mostly from the gear box, and the fault signal is generally nonlinear and nonstationary. The traditional fault diagnosis methods such as Fast Fourier transform (FFT and the inverted frequency spectrum identification method based on FFT are not satisfactory in processing this kind of signal. This paper proposes a hybrid fault diagnosis method which combines the empirical mode decomposition (EMD and wavelet transform. The vibration signal is analyzed through wavelet transform, and the aliasing in high-frequency signals is then addressed by conducting EMD to the original signals. The experimental results based on a specific wind turbine gear box demonstrate that this method can diagnose the faults and locate their positions accurately.

  15. Partial deficiency of emerin caused by a splice site mutation in EMD.

    Science.gov (United States)

    Yuan, Junhui; Ando, Masahiro; Higuchi, Itsuro; Sakiyama, Yusuke; Matsuura, Eiji; Michizono, Kumiko; Watanabe, Osamu; Nagano, Shinjiro; Inamori, Yukie; Hashiguchi, Akihiro; Higuchi, Yujiro; Yoshimura, Akiko; Takashima, Hiroshi

    2014-01-01

    Emery-Dreifuss muscular dystrophy (EDMD) is caused by mutations in the EMD gene on the X chromosome, which codes for emerin, an inner nuclear membrane protein. Monoclonal antibodies against the N-terminus of emerin protein are used to screen for emerin deficiency in clinical practice. However, these tests may not accurately reflect the disease in some cases. We herein describe the identification of a splice site mutation in the EMD gene in a Japanese patient who suffered from complete atrioventricular conduction block, mild muscle weakness and joint contracture, and a persistently elevated serum creatine kinase level. We used multiple antibodies to confirm the presence of a novel truncating mutation in emerin without the transmembrane region and C-terminus in the skeletal muscle.

  16. Long-Term Sunspot Number Prediction based on EMD Analysis and AR Model

    Institute of Scientific and Technical Information of China (English)

    Tong Xu; Jian Wu; Zhen-Sen Wu; Qiang Li

    2008-01-01

    The Empirical Mode Decomposition (EMD) and Auto-Regressive model (AR) are applied to a long-term prediction of sunspot numbers. With the sample data of sunspot numbers from 1848 to 1992, the method is evaluated by examining the measured data of the solar cycle 23 with the prediction: different time scale components are obtained by the EMD method and multi-step predicted values are combined to reconstruct the sunspot number time series. The result is remarkably good in comparison to the predictions made by the solar dynamo and precursor approaches for cycle 23. Sunspot numbers of the coming solar cycle 24 are obtained with the data from 1848 to 2007, the maximum amplitude of the next solar cycle is predicted to be about 112 in 2011-2012.

  17. EMD-Based Symbolic Dynamic Analysis for the Recognition of Human and Nonhuman Pyroelectric Infrared Signals.

    Science.gov (United States)

    Zhao, Jiaduo; Gong, Weiguo; Tang, Yuzhen; Li, Weihong

    2016-01-20

    In this paper, we propose an effective human and nonhuman pyroelectric infrared (PIR) signal recognition method to reduce PIR detector false alarms. First, using the mathematical model of the PIR detector, we analyze the physical characteristics of the human and nonhuman PIR signals; second, based on the analysis results, we propose an empirical mode decomposition (EMD)-based symbolic dynamic analysis method for the recognition of human and nonhuman PIR signals. In the proposed method, first, we extract the detailed features of a PIR signal into five symbol sequences using an EMD-based symbolization method, then, we generate five feature descriptors for each PIR signal through constructing five probabilistic finite state automata with the symbol sequences. Finally, we use a weighted voting classification strategy to classify the PIR signals with their feature descriptors. Comparative experiments show that the proposed method can effectively classify the human and nonhuman PIR signals and reduce PIR detector's false alarms.

  18. A Hybrid Approach for Fault Diagnosis of Railway Rolling Bearings Using STWD-EMD-GA-LSSVM

    Directory of Open Access Journals (Sweden)

    Dechen Yao

    2016-01-01

    Full Text Available Vibration signals resulting from railway rolling bearings are nonstationary by nature; this paper proposes a hybrid approach for the fault diagnosis of railway rolling bearings using segment threshold wavelet denoising (STWD, empirical mode decomposition (EMD, genetic algorithm (GA, and least squares support vector machine (LSSVM. The original signal is first denoised using STWD as a prefilter, which improves the subsequent decomposition into a number of intrinsic mode functions (IMFs using EMD. Secondly, the IMF energy-torques are extracted as feature parameters. Concurrently, a GA is employed to optimize the LSSVM to improve the classification accuracy. Finally, the extracted features are used as inputs for classification by the GA-LSSVM. Actual railway rolling bearing vibration signals are used to experimentally verify the effectiveness of the proposed method. The results show that the novel method is effective and accurate for fault diagnosis of railway rolling bearings.

  19. Three-Dimensional In Vitro Skin and Skin Cancer Models Based on Human Fibroblast-Derived Matrix.

    Science.gov (United States)

    Berning, Manuel; Prätzel-Wunder, Silke; Bickenbach, Jackie R; Boukamp, Petra

    2015-09-01

    Three-dimensional in vitro skin and skin cancer models help to dissect epidermal-dermal and tumor-stroma interactions. In the model presented here, normal human dermal fibroblasts isolated from adult skin self-assembled into dermal equivalents with their specific fibroblast-derived matrix (fdmDE) over 4 weeks. The fdmDE represented a complex human extracellular matrix that was stabilized by its own heterogeneous collagen fiber meshwork, largely resembling a human dermal in vivo architecture. Complemented with normal human epidermal keratinocytes, the skin equivalent (fdmSE) thereof favored the establishment of a well-stratified and differentiated epidermis and importantly allowed epidermal regeneration in vitro for at least 24 weeks. Moreover, the fdmDE could be used to study the features of cutaneous skin cancer. Complementing fdmDE with HaCaT cells in different stages of malignancy or tumor-derived cutaneous squamous cell carcinoma cell lines, the resulting skin cancer equivalents (fdmSCEs) recapitulated the respective degree of tumorigenicity. In addition, the fdmSCE invasion phenotypes correlated with their individual degree of tissue organization, disturbance in basement membrane organization, and presence of matrix metalloproteinases. Together, fdmDE-based models are well suited for long-term regeneration of normal human epidermis and, as they recapitulate tumor-specific growth, differentiation, and invasion profiles of cutaneous skin cancer cells, also provide an excellent human in vitro skin cancer model.

  20. Beneficial effects of the Ca2+ sensitizer EMD 57033 in exercising pigs with infarction-induced chronic left ventricular dysfunction.

    NARCIS (Netherlands)

    D.J.G.M. Duncker (Dirk); D.B. Haitsma; D. Liem (Djien); N. Heins; R. Stubenitsky (René); P.D. Verdouw (Pieter)

    2001-01-01

    textabstract1. It is unknown how cardiac stimulation by Ca(2+) sensitization modulates the cardiovascular response to exercise when left ventricular (LV) function is chronically depressed following a myocardial infarction. We therefore investigated the effects of EMD 57033 at rest

  1. EMD-Based Temporal and Spectral Features for the Classification of EEG Signals Using Supervised Learning.

    Science.gov (United States)

    Riaz, Farhan; Hassan, Ali; Rehman, Saad; Niazi, Imran Khan; Dremstrup, Kim

    2016-01-01

    This paper presents a novel method for feature extraction from electroencephalogram (EEG) signals using empirical mode decomposition (EMD). Its use is motivated by the fact that the EMD gives an effective time-frequency analysis of nonstationary signals. The intrinsic mode functions (IMF) obtained as a result of EMD give the decomposition of a signal according to its frequency components. We present the usage of upto third order temporal moments, and spectral features including spectral centroid, coefficient of variation and the spectral skew of the IMFs for feature extraction from EEG signals. These features are physiologically relevant given that the normal EEG signals have different temporal and spectral centroids, dispersions and symmetries when compared with the pathological EEG signals. The calculated features are fed into the standard support vector machine (SVM) for classification purposes. The performance of the proposed method is studied on a publicly available dataset which is designed to handle various classification problems including the identification of epilepsy patients and detection of seizures. Experiments show that good classification results are obtained using the proposed methodology for the classification of EEG signals. Our proposed method also compares favorably to other state-of-the-art feature extraction methods.

  2. Rosin and rosin derivatives as hydrophobic matrix materials for controlled release of drugs.

    Science.gov (United States)

    Pathak, Y V; Dorle, A K

    1990-09-01

    The evaluation of rosin, a rosin hard paraffin adduct, and four rosin esters as hydrophobic matrix materials for the controlled release of drugs is reported, using aspirin as a drug model. Aspirin matrix tablets were prepared using a wet granulation (nonaqueous) method, and were evaluated for various pharmaceutical parameters. Dissolution studies in pH 7.2 phosphate buffer showed that all formulations had hardness greater than 6 kg/cm2 and disintegration time greater than 150 min. Release of aspirin from the formulations obeyed a diffusion controlled first order kinetic and linear to the square root of time function. Two of the resin ester formulations had a T80% of more than 4 hr. The results suggest that these esters may find application in the development of sustained release formulations for the local treatment of dental diseases, or--as tablet matrices suitably coated with acid resistant material--in the development of oral sustained release drug delivery systems.

  3. Derivation of the density matrix of a single photon produced in parametric down-conversion

    Science.gov (United States)

    Kolenderski, Piotr; Wasilewski, Wojciech

    2009-07-01

    We discuss an effective numerical method of density matrix determination of fiber coupled single photon generated in process of spontaneous parametric down conversion in type I noncollinear configuration. The presented theory has been successfully applied in case of source utilized to demonstrate the experimental characterization of spectral state of single photon, what was reported in Wasilewski, Kolenderski, and Frankowski [Phys. Rev. Lett. 99, 123601 (2007)].

  4. Use of Knowledge Base Systems (EMDS) in Strategic and Tactical Forest Planning

    Science.gov (United States)

    Jensen, M. E.; Reynolds, K.; Stockmann, K.

    2008-12-01

    The USDA Forest Service 2008 Planning Rule requires Forest plans to provide a strategic vision for maintaining the sustainability of ecological, economic, and social systems across USFS lands through the identification of desired conditions and objectives. In this paper we show how knowledge-based systems can be efficiently used to evaluate disparate natural resource information to assess desired conditions and related objectives in Forest planning. We use the Ecosystem Management Decision Support (EMDS) system (http://www.institute.redlands.edu/emds/), which facilitates development of both logic-based models for evaluating ecosystem sustainability (desired conditions) and decision models to identify priority areas for integrated landscape restoration (objectives). The study area for our analysis spans 1,057 subwatersheds within western Montana and northern Idaho. Results of our study suggest that knowledge-based systems such as EMDS are well suited to both strategic and tactical planning and that the following points merit consideration in future National Forest (and other land management) planning efforts: 1) Logic models provide a consistent, transparent, and reproducible method for evaluating broad propositions about ecosystem sustainability such as: are watershed integrity, ecosystem and species diversity, social opportunities, and economic integrity in good shape across a planning area? The ability to evaluate such propositions in a formal logic framework also allows users the opportunity to evaluate statistical changes in outcomes over time, which could be very useful for regional and national reporting purposes and for addressing litigation; 2) The use of logic and decision models in strategic and tactical Forest planning provides a repository for expert knowledge (corporate memory) that is critical to the evaluation and management of ecosystem sustainability over time. This is especially true for the USFS and other federal resource agencies, which are

  5. A Novel Operational Matrix of Caputo Fractional Derivatives of Fibonacci Polynomials: Spectral Solutions of Fractional Differential Equations

    Directory of Open Access Journals (Sweden)

    Waleed M. Abd-Elhameed

    2016-09-01

    Full Text Available Herein, two numerical algorithms for solving some linear and nonlinear fractional-order differential equations are presented and analyzed. For this purpose, a novel operational matrix of fractional-order derivatives of Fibonacci polynomials was constructed and employed along with the application of the tau and collocation spectral methods. The convergence and error analysis of the suggested Fibonacci expansion were carefully investigated. Some numerical examples with comparisons are presented to ensure the efficiency, applicability and high accuracy of the proposed algorithms. Two accurate semi-analytic polynomial solutions for linear and nonlinear fractional differential equations are the result.

  6. Buttressing staples with cholecyst-derived extracellular matrix (CEM) reinforces staple lines in an ex vivo peristaltic inflation model.

    LENUS (Irish Health Repository)

    Burugapalli, Krishna

    2008-11-01

    Staple line leakage and bleeding are the most common problems associated with the use of surgical staplers for gastrointestinal resection and anastomotic procedures. These complications can be reduced by reinforcing the staple lines with buttressing materials. The current study reports the potential use of cholecyst-derived extracellular matrix (CEM) in non-crosslinked (NCEM) and crosslinked (XCEM) forms, and compares their mechanical performance with clinically available buttress materials [small intestinal submucosa (SIS) and bovine pericardium (BP)] in an ex vivo small intestine model.

  7. Long-term clinical observation of treatment of infrabony defects with enamel matrix derivative (Emdogain): surgical reentry.

    Science.gov (United States)

    Rasperini, Giulio; Silvestri, Maurizio; Ricci, Giano

    2005-04-01

    A surgical protocol for the placement of Emdogain during new attachment procedures was published in this journal in 1999. Three cases with infrabony defects were treated, and significant periodontal attachment level gain, probing depth reduction, and bone fill were evident upon clinical probing and reentry procedures after 1 year. The patients were enrolled in a maintenance protocol with 3-month recall visits. After 7 years, the clinical parameters were stable, as was the radiographic evaluation. Surgical reentry after 7 years in two cases and 5 years in one case demonstrated the stability of the previous findings. These data show the long-term efficacy of enamel matrix derivative in new attachment procedures.

  8. Ascorbate-dependent impact on cell-derived matrix in modulation of stiffness and rejuvenation of infrapatellar fat derived stem cells toward chondrogenesis.

    Science.gov (United States)

    Pizzute, Tyler; Zhang, Ying; He, Fan; Pei, Ming

    2016-08-10

    Developing an in vitro microenvironment using cell-derived decellularized extracellular matrix (dECM) is a promising approach to efficiently expand adult stem cells for cartilage engineering and regeneration. Ascorbic acid serves as a critical stimulus for cells to synthesize collagens, which constitute the major component of dECM. In this study, we hypothesized that optimization of ascorbate treatment would maximize the rejuvenation effect of dECM on expanded stem cells from human infrapatellar fat pad in both proliferation and chondrogenic differentiation. In the duration regimen study, we found that dECM without L-ascorbic acid phosphate (AA) treatment, exhibiting lower stiffness measured by atomic force microscopy, yielded expanded cells with higher proliferation capacity but lower chondrogenic potential when compared to those with varied durations of AA treatment. dECM with 250 µM of AA treatment for 10 d had better rejuvenation in chondrogenic capacity if the deposited cells were from passage 2 rather than passage 5, despite no significant difference in matrix stiffness. In the dose regimen study, we found that dECMs deposited by varied concentrations of AA yielded expanded cells with higher proliferation capacity despite lower expression levels of stem cell related surface markers. Compared to cells expanded on tissue culture polystyrene, those on dECM exhibited greater chondrogenic potential, particularly for the dECMs with 50 µM and 250 µM of AA treatment. With the supplementation of ethyl-3,4-dihydroxybenzoate (EDHB), an inhibitor targeting procollagen synthesis, the dECM with 50 µM of AA treatment exhibited a dramatic decrease in the rejuvenation effect of expanded cell chondrogenic potential at both mRNA and protein levels despite no significant difference in matrix stiffness. Defined AA treatments during matrix preparation will benefit dECM-mediated stem cell engineering and future treatments for cartilage defects.

  9. Analysis of chlorophylls and their derivatives by matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry.

    Science.gov (United States)

    Suzuki, Toshiyuki; Midonoya, Hitoshi; Shioi, Yuzo

    2009-07-01

    The analysis of chlorophylls and their derivatives by matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry is described. Four matrices-sinapinic acid, a-cyano-4-hydroxycinnnamic acid, terthiophene, and 3-aminoquinoline-were examined to determine optimal conditions for analysis of the molecular mass and structure of chlorophyll a as a representative chlorophyll. Among them, terthiophene was the most efficient without releasing metal ions, although it caused fragmentation of the phytol-ester linkage. Terthiophene was useful for the analyses of chlorophyll derivatives as well as porphyrin products such as 8-deethyl-8-vinyl-chlorophyll a, pheophorbide a, pyropheophorbide a, bacteriochlorophyll a esterified phytol, and protoporphyrin IX. The current method is suitable for rapid and accurate determination of the molecular mass and structure of chlorophylls and porphyrins.

  10. Effects of matrix metalloproteinase-1 on the myogenic differentiation of bone marrow-derived mesenchymal stem cells in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Zhenyang [Department of Neurology, The First Affiliated Hospital, Sun Yat-sen University, No. 58, Zhongshan 2nd Road, Guangzhou 510080, Guangdong Province (China); Leng, Yan [Department of Rehabilitation, The First Affiliated Hospital, Sun Yat-sen University, No. 58, Zhongshan 2nd Road, Guangzhou 510080, Guangdong Province (China); Zhou, Chen; Ma, Zhenyu; Zhong, Zhigang [Department of Neurology, The First Affiliated Hospital, Sun Yat-sen University, No. 58, Zhongshan 2nd Road, Guangzhou 510080, Guangdong Province (China); Shi, Xing-Ming [Institute of Molecular Medicine and Genetics, Georgia Health Sciences University, Augusta, GA 30912 (United States); Zhang, Weixi, E-mail: weixizhang@qq.com [Department of Neurology, The First Affiliated Hospital, Sun Yat-sen University, No. 58, Zhongshan 2nd Road, Guangzhou 510080, Guangdong Province (China)

    2012-11-16

    Highlights: Black-Right-Pointing-Pointer MMP-1 is a member of the zinc-dependent endopeptidase family. Black-Right-Pointing-Pointer MMP-1 has no cytotoxic effects on BMSCs. Black-Right-Pointing-Pointer MMP-1 can promote the myogenic differentiation of BMSCs. Black-Right-Pointing-Pointer MyoD and desmin were chosen as myogenic markers in this study. -- Abstract: Matrix metalloproteinase-1 (MMP-1) is a member of the family of zinc-dependent endopeptidases that are capable of degrading extracellular matrix (ECM) and certain non-matrix proteins. It has been shown that MMP-1 can enhance muscle regeneration by improving the differentiation and migration of myoblasts. However, it is still not known whether MMP-1 can promote the myogenesis of bone marrow-derived mesenchymal stem cells (BMSCs). To address this question, we isolated BMSCs from C57BL/6J mice and investigated the effects of MMP-1 on their proliferation and myogenic differentiation. Our results showed that MMP-1 treatment, which had no cytotoxic effects on BMSCs, increased the mRNA and protein levels of MyoD and desmin in a dose-dependent manner, indicating that MMP-1 promoted myogenic differentiation of BMSCs in vitro. These results suggest that BMSCs may have a therapeutic potential for treating muscular disorders.

  11. The influence of physiological matrix conditions on permanent culture of induced pluripotent stem cell-derived cardiomyocytes.

    Science.gov (United States)

    Heras-Bautista, Carlos O; Katsen-Globa, Alisa; Schloerer, Nils E; Dieluweit, Sabine; Abd El Aziz, Osama M; Peinkofer, Gabriel; Attia, Wael A; Khalil, Markus; Brockmeier, Konrad; Hescheler, Jürgen; Pfannkuche, Kurt

    2014-08-01

    Cardiomyocytes (CMs) from induced pluripotent stem (iPS) cells mark an important achievement in the development of in vitro pharmacological, toxicological and developmental assays and in the establishment of protocols for cardiac cell replacement therapy. Using CMs generated from murine embryonic stem cells and iPS cells we found increased cell-matrix interaction and more matured embryoid body (EB) structures in iPS cell-derived EBs. However, neither suspension-culture in form of purified cardiac clusters nor adherence-culture on traditional cell culture plastic allowed for extended culture of CMs. CMs grown for five weeks on polystyrene exhibit signs of massive mechanical stress as indicated by α-smooth muscle actin expression and loss of sarcomere integrity. Hydrogels from polyacrylamide allow adapting of the matrix stiffness to that of cardiac tissue. We were able to eliminate the bottleneck of low cell adhesion using 2,5-Dioxopyrrolidin-1-yl-6-acrylamidohexanoate as a crosslinker to immobilize matrix proteins on the gels surface. Finally we present an easy method to generate polyacrylamide gels with a physiological Young's modulus of 55 kPa and defined surface ligand, facilitating the culture of murine and human iPS-CMs, removing excess mechanical stresses and reducing the risk of tissue culture artifacts exerted by stiff substrates.

  12. Host-Parasite Interaction: Parasite-Derived and -Induced Proteases That Degrade Human Extracellular Matrix

    Directory of Open Access Journals (Sweden)

    Carolina Piña-Vázquez

    2012-01-01

    Full Text Available Parasitic protozoa are among the most important pathogens worldwide. Diseases such as malaria, leishmaniasis, amoebiasis, giardiasis, trichomoniasis, and trypanosomiasis affect millions of people. Humans are constantly threatened by infections caused by these pathogens. Parasites engage a plethora of surface and secreted molecules to attach to and enter mammalian cells. The secretion of lytic enzymes by parasites into host organs mediates critical interactions because of the invasion and destruction of interstitial tissues, enabling parasite migration to other sites within the hosts. Extracellular matrix is a complex, cross-linked structure that holds cells together in an organized assembly and that forms the basement membrane lining (basal lamina. The extracellular matrix represents a major barrier to parasites. Therefore, the evolution of mechanisms for connective-tissue degradation may be of great importance for parasite survival. Recent advances have been achieved in our understanding of the biochemistry and molecular biology of proteases from parasitic protozoa. The focus of this paper is to discuss the role of protozoan parasitic proteases in the degradation of host ECM proteins and the participation of these molecules as virulence factors. We divide the paper into two sections, extracellular and intracellular protozoa.

  13. Growth factor priming differentially modulates components of the extracellular matrix proteome in chondrocytes and synovium-derived stem cells.

    Directory of Open Access Journals (Sweden)

    Elena Alegre-Aguarón

    Full Text Available To make progress in cartilage repair it is essential to optimize protocols for two-dimensional cell expansion. Chondrocytes and SDSCs are promising cell sources for cartilage repair. We previously observed that priming with a specific growth factor cocktail (1 ng/mL transforming growth factor-β1, 5 ng/mL basic fibroblast growth factor, and 10 ng/mL platelet-derived growth factor-BB in two-dimensional culture, led to significant improvement in mechanical and biochemical properties of synovium-derived stem cell (SDSC-seeded constructs. The current study assessed the effect of growth factor priming on the proteome of canine chondrocytes and SDSCs. In particular, growth factor priming modulated the proteins associated with the extracellular matrix in two-dimensional cultures of chondrocytes and SDSCs, inducing a partial dedifferentiation of chondrocytes (most proteins associated with cartilage were down-regulated in primed chondrocytes and a partial differentiation of SDSCs (some collagen-related proteins were up-regulated in primed SDSCs. However, when chondrocytes and SDSCs were grown in pellet culture, growth factor-primed cells maintained their chondrogenic potential with respect to glycosaminoglycan and collagen production. In conclusion, the strength of the label-free proteomics technique is that it allows for the determination of changes in components of the extracellular matrix proteome in chondrocytes and SDSCs in response to growth factor priming, which could help in future tissue engineering strategies.

  14. Generation and periodontal differentiation of human gingival fibroblasts-derived integration-free induced pluripotent stem cells

    Energy Technology Data Exchange (ETDEWEB)

    Yin, Xiaohui [Department of Periodontology, School and Hospital of Stomatology, Peking University, 22 South Avenue Zhong-Guan-Cun, Beijing 100081 (China); Peking University Stem Cell Research Center and Department of Cell Biology, School of Basic Medical Sciences, Peking University, 38 Xueyuan Road, Beijing 100191 (China); Li, Yang [Peking University Stem Cell Research Center and Department of Cell Biology, School of Basic Medical Sciences, Peking University, 38 Xueyuan Road, Beijing 100191 (China); Li, Jingwen [Department of Periodontology, School and Hospital of Stomatology, Peking University, 22 South Avenue Zhong-Guan-Cun, Beijing 100081 (China); Li, Peng [Faculty of Dentistry, The University of Hong Kong, 34 Hospital Road, Hong Kong SAR (China); Liu, Yinan [Peking University Stem Cell Research Center and Department of Cell Biology, School of Basic Medical Sciences, Peking University, 38 Xueyuan Road, Beijing 100191 (China); Wen, Jinhua, E-mail: jhwen@bjmu.edu.cn [Peking University Stem Cell Research Center and Department of Cell Biology, School of Basic Medical Sciences, Peking University, 38 Xueyuan Road, Beijing 100191 (China); Luan, Qingxian, E-mail: kqluanqx@126.com [Department of Periodontology, School and Hospital of Stomatology, Peking University, 22 South Avenue Zhong-Guan-Cun, Beijing 100081 (China)

    2016-05-06

    Induced pluripotent stem cells (iPSCs) have been recognized as a promising cell source for periodontal tissue regeneration. However, the conventional virus-based reprogramming approach is associated with a high risk of genetic mutation and limits their therapeutic utility. Here, we successfully generated iPSCs from readily accessible human gingival fibroblasts (hGFs) through an integration-free and feeder-free approach via delivery of reprogramming factors of Oct4, Sox2, Klf4, L-myc, Lin28 and TP53 shRNA with episomal plasmid vectors. The iPSCs presented similar morphology and proliferation characteristics as embryonic stem cells (ESCs), and expressed pluripotent markers including Oct4, Tra181, Nanog and SSEA-4. Additionally, these cells maintained a normal karyotype and showed decreased CpG methylation ratio in the promoter regions of Oct4 and Nanog. In vivo teratoma formation assay revealed the development of tissues representative of three germ layers, confirming the acquisition of pluripotency. Furthermore, treatment of the iPSCs in vitro with enamel matrix derivative (EMD) or growth/differentiation factor-5 (GDF-5) significantly up-regulated the expression of periodontal tissue markers associated with bone, periodontal ligament and cementum respectively. Taken together, our data demonstrate that hGFs are a valuable cell source for generating integration-free iPSCs, which could be sequentially induced toward periodontal cells under the treatment of EMD and GDF-5. - Highlights: • Integration-free iPSCs are successfully generated from hGFs via an episomal approach. • EMD promotes differentiation of the hGFs-derived iPSCs toward periodontal cells. • GDF-5 promotes differentiation of the hGFs-derived iPSCs toward periodontal cells. • hGFs-derived iPSCs could be a promising cell source for periodontal regeneration.

  15. Pigment epithelium derived factor suppresses expression of Sost/Sclerostin by osteocytes: implication for its role in bone matrix mineralization.

    Science.gov (United States)

    Li, Feng; Song, Na; Tombran-Tink, Joyce; Niyibizi, Christopher

    2015-06-01

    Mutations in Serpinf1 gene which encodes pigment epithelium derived factor (PEDF) lead to osteogenesis imperfecta type VI whose hallmark is defective mineralization. Mechanisms by which PEDF regulates matrix mineralization remain unknown. We examined effect of exogenous PEDF on expression of osteoblastic and osteocytic related genes and proteins in mineralizing osteoblast culture. Mineralizing human osteoblasts supplemented with exogenous PEDF for 14 days deposited 47% more mineral than cells cultured without PEDF. Analysis of selected gene expression by cells in mineralizing cultures supplemented with exogenous PEDF showed reduction in expression of Sclerostin (Sost) by 70%, matrix extracellular phosphoglycoprotein (MEPE) by 75% and dentin matrix protein (DMP-1) by 20% at day 14 of culture. Phosphate-regulating gene with homologies to endopeptidases on the X chromosome (PHEX) expression was not affected. Western blotting and immunoprecipitation showed that sclerostin and MEPE synthesis by osteocytes were reduced by 50% and 60% respectively in mineralizing osteoblasts containing exogenous PEDF. Primary osteocytes exposed to PEDF also reduced synthesis of Sost/sclerostin by 50% within 24 h. For osteoblastic genes, Bone sialoprotein (BSP) was expressed at 75% higher by day 7 in cultures containing exogenous PEDF while Col1A1 expression remained high at all-time points. Total beta-catenin was increased in mineralizing osteoblastic cells suggesting increased Wnt activity. Taken together, the data indicate that PEDF suppressed expression of factors that inhibit mineralization while enhancing those that promote mineralization. The findings also suggest that PEDF may regulate Sost expression by osteocytes leading to enhanced osteoblastic differentiation and increased matrix mineralization.

  16. Perturbative Derivation of Exact Superpotential for Meson Fields from Matrix Theories with One Flavour

    CERN Document Server

    Suzuki, H

    2003-01-01

    We derive the superpotential of gauge theories having matter fields in the fundamental representation of gauge fields by using the method of Dijkgraaf and Vafa. We treat the theories with one flavour and reproduce a well-known non-perturbative superpotential for meson field.

  17. A Detailed Derivation of Gaussian Orbital-Based Matrix Elements in Electron Structure Calculations

    Science.gov (United States)

    Petersson, T.; Hellsing, B.

    2010-01-01

    A detailed derivation of analytic solutions is presented for overlap, kinetic, nuclear attraction and electron repulsion integrals involving Cartesian Gaussian-type orbitals. It is demonstrated how s-type orbitals can be used to evaluate integrals with higher angular momentum via the properties of Hermite polynomials and differentiation with…

  18. A Detailed Derivation of Gaussian Orbital-Based Matrix Elements in Electron Structure Calculations

    Science.gov (United States)

    Petersson, T.; Hellsing, B.

    2010-01-01

    A detailed derivation of analytic solutions is presented for overlap, kinetic, nuclear attraction and electron repulsion integrals involving Cartesian Gaussian-type orbitals. It is demonstrated how s-type orbitals can be used to evaluate integrals with higher angular momentum via the properties of Hermite polynomials and differentiation with…

  19. Enamel matrix proteins associated with GTR and bioactive glass in the treatment of class III furcation in dogs Proteína da matriz do esmalte associada a R.T.G. e vidro bioativo no tratamento de furca grau III em cães

    Directory of Open Access Journals (Sweden)

    José Marcos Alves Fernandes

    2005-09-01

    Full Text Available This study investigated, both histologically and histometrically, the efficacy of enamel matrix derived proteins (EMD associated with bioactive glass (BG and an absorbable membrane in the treatment of class III furcation defects in mongrel dogs. After surgical defect creation and chronification, the lesions were randomly divided into three groups according to the treatment employed: Test Group 1 - EMD + BG + membrane, Test Group 2 - EMD + membrane and Control Group - BG + membrane. After a 90-day healing period, the dogs were sacrificed. The descriptive analysis and the histometric data showed similar results for the experimental groups in all studied parameters (MANOVA, p > 0.05. The association of Emdogain® with bioglass and GTR, or with GTR only, showed similar results when compared with the ones obtained with bioglass associated with membrane in the treatment of class III furcation defects in dogs. The three modalities of treatment showed partial filling of the furcations, with bone and cementum regeneration limited to the apical portion of the defects.Este estudo investigou, histológica e histometricamente, a eficácia da proteína derivada da matriz de esmalte (EMD associada com vidro bioativo (BG e membrana absorvível, no tratamento de defeitos de furcas classe III em cães. Após criação cirúrgica e cronificação dos defeitos, as lesões foram divididas aleatoriamente em três grupos de acordo com o tratamento proposto: Grupo Teste 1 - EMD + BG + membrana, Grupo Teste 2 - EMD + membrana e Grupo Controle - BG + membrana. Após 90 dias do período de cicatrização, os cães foram sacrificados. A análise descritiva e os dados histométricos mostraram resultados similares para os grupos experimentais em todos os parâmetros estudados (MANOVA, p > 0,05. As associações de Emdogain com vidro bioativo e RTG, ou somente com RTG, mostraram resultados similares quando comparadas ao vidro bioativo associado à membrana no tratamento de

  20. Cell migration in schizophrenia: Patient-derived cells do not regulate motility in response to extracellular matrix.

    Science.gov (United States)

    Tee, Jing Yang; Sutharsan, Ratneswary; Fan, Yongjun; Mackay-Sim, Alan

    2017-03-09

    Schizophrenia is a highly heritable psychiatric disorder linked to a large number of risk genes. The function of these genes in disease etiology is not fully understood but pathway analyses of genomic data suggest developmental dysregulation of cellular processes such as neuronal migration and axon guidance. Previous studies of patient-derived olfactory cells show them to be more motile than control-derived cells when grown on a fibronectin substrate, motility that is dependent on focal adhesion kinase signaling. The aim of this study was to investigate whether schizophrenia patient-derived cells are responsive to other extracellular matrix (ECM) proteins that bind integrin receptors. Olfactory neurosphere-derived cells from nine patients and nine matched controls were grown on ECM protein substrates at increasing concentrations and their movement was tracked for 24h using automated high-throughput imaging. Control-derived cells increased their motility as the ECM substrate concentration increased, whereas patient-derived cell motility was little affected by ECM proteins. Patient and control cells had appropriate integrin receptors for these ECM substrates and detected them as shown by increases in focal adhesion number and size in response to ECM proteins, which also induced changes in cell morphology and cytoskeleton. These observations indicate that patient cells failed to translate the detection of ECM proteins into appropriate changes in cell motility. In a sense, patient cells act like a moving car whose accelerator is jammed, moving at the same speed without regard to the external environment. This focuses attention on cell motility regulation rather than speed as key to impairment of neuronal migration in the developing brain in schizophrenia.

  1. Human lung fibroblast-derived matrix facilitates vascular morphogenesis in 3D environment and enhances skin wound healing.

    Science.gov (United States)

    Du, Ping; Suhaeri, Muhammad; Ha, Sang Su; Oh, Seung Ja; Kim, Sang-Heon; Park, Kwideok

    2017-05-01

    Extracellular matrix (ECM) is crucial to many aspects of vascular morphogenesis and maintenance of vasculature function. Currently the recapitulation of angiogenic ECM microenvironment is still challenging, due mainly to its diverse components and complex organization. Here we investigate the angiogenic potential of human lung fibroblast-derived matrix (hFDM) in creating a three-dimensional (3D) vascular construct. hFDM was obtained via decellularization of in vitro cultured human lung fibroblasts and analyzed via immunofluorescence staining and ELISA, which detect multiple ECM macromolecules and angiogenic growth factors (GFs). Human umbilical vein endothelial cells (HUVECs) morphology was more elongated and better proliferative on hFDM than on gelatin-coated substrate. To prepare 3D construct, hFDM is collected, quantitatively analyzed, and incorporated in collagen hydrogel (Col) with HUVECs. Capillary-like structure (CLS) formation at 7day was significantly better with the groups containing higher doses of hFDM compared to the Col group (control). Moreover, the group (Col/hFDM/GFs) with both hFDM and angiogenic GFs (VEGF, bFGF, SDF-1) showed the synergistic activity on CLS formation and found much larger capillary lumen diameters with time. Further analysis of hFDM via angiogenesis antibody array kit reveals abundant biochemical cues, such as angiogenesis-related cytokines, GFs, and proteolytic enzymes. Significantly up-regulated expression of VE-cadherin and ECM-specific integrin subunits was also noticed in Col/hFDM/GFs. In addition, transplantation of Col/hFMD/GFs with HUVECs in skin wound model presents more effective re-epithelialization, many regenerated hair follicles, better transplanted cells viability, and advanced neovascularization. We believe that current system is a very promising platform for 3D vasculature construction in vitro and for cell delivery toward therapeutic applications in vivo. Functional 3D vasculature construction in vitro is still

  2. Feature Abstracting and Identification of Acoustic Target in the Battle Field Based on EMD

    Institute of Scientific and Technical Information of China (English)

    CAI Shao-chuan; ZHANG Guo-wei

    2007-01-01

    The method of empirical mode decomposition(EMD) was used for the signal processing and feature abstracting of acoustic target of battle field.According to the signal's characteristics of different targets, some feature vectors in token of the target properties were constructed and abstracted.In the basis of feature abstracting and statistic analysis for large amount of sample signal of the targets, using the maximum subjection classification method based on the fuzzy synthesis judgment, the three typical acoustic target helicopter, tank and traffic vehicle were recognized.

  3. Boundary-processing-techni- que in EMD method and Hil-bert transform

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    By virtue of neural network, a series of signals is extended forward and backward, as a result, two additional maxima and two additional minima are obtained at both ends of the original data set, with which the EMD decomposition can be exactly achieved with cubic spline interpolation. Meanwhile, by using of neural network every IMF component can also be extended forward and backward, which effectively restrains the end effect, thus the veracious Hilbert spectra are achieved. Verifications of the sample signals and the actual surface elevation of sea waves show that the present extension method is relatively accurate.

  4. Host-derived Loss of Dentin Matrix Stiffness Associated with Solubilization of Collagen

    Science.gov (United States)

    Carrilho, Marcela R.; Tay, Franklin R.; Donnelly, Adam M.; Agee, Kelli A.; Tjäderhane, Leo; Mazzoni, Annalisa; Breschi, Lorenzo; Foulger, Stephen; Pashley, David H.

    2009-01-01

    Matrix metalloproteinases (MMPs) bound to dentin matrices are activated during adhesive bonding procedures and are thought to contribute to the progressive degradation of resin-dentin bonds over time. The purpose of this study was to evaluate the changes in mechanical, biochemical and structural properties of demineralized dentin treated with or without chlorhexidine (CHX), a known MMP-inhibitor. After demineralizing dentin beams in EDTA or phosphoric acid (PA), the baseline modulus of elasticity (E) of each beam was measured by 3-point flexure. Specimens were pretreated with water (control) or with 2% CHX (experimental) and then incubated in artificial saliva (AS) at 37°C for 4 weeks. The E of each specimen was remeasured weekly and, the media was analyzed for solubilized dentin collagen at first and fourth week of incubation. Some specimens were processed for electron microscopy (TEM) immediately after demineralization and after 4 weeks of incubation. In EDTA and PA-demineralized specimens, the E of the control specimens fell (p<0.05) after incubation in AS, while there were no changes in E in the CHX-pretreated specimens over time. More collagen was solubilized from PA-demineralized controls (p<0.05) than from EDTA-demineralized matrices after 1 or 4 weeks. Less collagen (p<0.05) was solubilized from CHX-pretreated specimens demineralized in EDTA compared to PA. TEM examination of control beams revealed that prolonged demineralization of dentin in 10% PA (12 h) did not denature the collagen fibrils. PMID:19090493

  5. Host-derived loss of dentin matrix stiffness associated with solubilization of collagen.

    Science.gov (United States)

    Carrilho, Marcela R; Tay, Franklin R; Donnelly, Adam M; Agee, Kelli A; Tjäderhane, Leo; Mazzoni, Annalisa; Breschi, Lorenzo; Foulger, Stephen; Pashley, David H

    2009-07-01

    Matrix metalloproteinases (MMPs) bound to dentin matrices are activated during adhesive bonding procedures and are thought to contribute to the progressive degradation of resin-dentin bonds over time. The purpose of this study was to evaluate the changes in mechanical, biochemical, and structural properties of demineralized dentin treated with or without chlorhexidine (CHX), a known MMP-inhibitor. After demineralizing dentin beams in EDTA or phosphoric acid (PA), the baseline modulus of elasticity (E) of each beam was measured by three-point flexure. Specimens were pretreated with water (control) or with 2% CHX (experimental) and then incubated in artificial saliva (AS) at 37 degrees C for 4 weeks. The E of each specimen was remeasured weekly and, the media was analyzed for solubilized dentin collagen at first and fourth week of incubation. Some specimens were processed for electron microscopy (TEM) immediately after demineralization and after 4 weeks of incubation. In EDTA and PA-demineralized specimens, the E of the control specimens fell (p < 0.05) after incubation in AS, whereas there were no changes in E of the CHX-pretreated specimens over time. More collagen was solubilized from PA-demineralized controls (p < 0.05) than from EDTA-demineralized matrices after 1 or 4 weeks. Less collagen (p < 0.05) was solubilized from CHX-pretreated specimens demineralized in EDTA compared with PA. TEM examination of control beams revealed that prolonged demineralization of dentin in 10% PA (12 h) did not denature the collagen fibrils.

  6. Cluster structure of EU-15 countries derived from the correlation matrix analysis of macroeconomic index fluctuations

    CERN Document Server

    Gligor, M

    2006-01-01

    The statistical distances between countries, calculated for various moving average time windows, are mapped into the ultrametric subdominant space as in classical Minimal Spanning Tree methods. The Moving Average Minimal Length Path (MAMLP) algorithm allows a decoupling of fluctuations with respect to the mass center of the system from the movement of the mass center itself. A Hamiltonian representation given by a factor graph is used and plays the role of cost function. The present analysis pertains to 11 macroeconomic (ME) indicators, namely the GDP (x1), Final Consumption Expenditure (x2), Gross Capital Formation (x3), Net Exports (x4), Consumer Price Index (y1), Rates of Interest of the Central Banks (y2), Labour Force (z1), Unemployment (z2), GDP/hour worked (z3), GDP/capita (w1) and Gini coefficient (w2). The target group of countries is composed of 15 EU countries, data taken between 1995 and 2004. By two different methods (the Bipartite Factor Graph Analysis and the Correlation Matrix Eigensystem Anal...

  7. A potential role for glia-derived extracellular matrix remodeling in postinjury epilepsy.

    Science.gov (United States)

    Kim, Soo Young; Porter, Brenda E; Friedman, Alon; Kaufer, Daniela

    2016-09-01

    Head trauma and vascular injuries are known risk factors for acquired epilepsy. The sequence of events that lead from the initial injury to the development of epilepsy involves complex plastic changes and circuit rewiring. In-depth, comprehensive understanding of the epileptogenic process is critical for the identification of disease-modifying targets. Here we review the complex interactions of cellular and extracellular components that may promote epileptogenesis, with an emphasis on the role of astrocytes. Emerging evidence demonstrates that astrocytes promptly respond to brain damage and play a critical role in the development of postinjury epilepsy. Astrocytes have been shown to regulate extracellular matrix (ECM) remodeling, which can affect plasticity and stability of synapses and, in turn, contribute to the epileptogenic process. From these separate lines of evidence, we present a hypothesis suggesting a possible role for astrocyte-regulated remodeling of ECM and perineuronal nets, a specialized ECM structure around fast-spiking inhibitory interneurons, in the development and progression of posttraumatic epilepsies. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  8. Cluster structure of EU-15 countries derived from the correlation matrix analysis of macroeconomic index fluctuations

    Science.gov (United States)

    Gligor, M.; Ausloos, M.

    2007-05-01

    The statistical distances between countries, calculated for various moving average time windows, are mapped into the ultrametric subdominant space as in classical Minimal Spanning Tree methods. The Moving Average Minimal Length Path (MAMLP) algorithm allows a decoupling of fluctuations with respect to the mass center of the system from the movement of the mass center itself. A Hamiltonian representation given by a factor graph is used and plays the role of cost function. The present analysis pertains to 11 macroeconomic (ME) indicators, namely the GDP (x1), Final Consumption Expenditure (x2), Gross Capital Formation (x3), Net Exports (x4), Consumer Price Index (y1), Rates of Interest of the Central Banks (y2), Labour Force (z1), Unemployment (z2), GDP/hour worked (z3), GDP/capita (w1) and Gini coefficient (w2). The target group of countries is composed of 15 EU countries, data taken between 1995 and 2004. By two different methods (the Bipartite Factor Graph Analysis and the Correlation Matrix Eigensystem Analysis) it is found that the strongly correlated countries with respect to the macroeconomic indicators fluctuations can be partitioned into stable clusters.

  9. Effects of extracellular matrix proteins in chondrocyte-derived matrices on chondrocyte functions.

    Science.gov (United States)

    Hoshiba, Takashi; Lu, Hongxu; Kawazoe, Naoki; Yamada, Tomoe; Chen, Guoping

    2013-01-01

    Loss of cartilaginous phenotype during in vitro expansion culture of chondrocytes is a major barrier to the application of chondrocytes for tissue engineering. In previous study, we showed that dedifferentiation of chondrocytes during the passage culture was delayed by matrices formed by primary chondrocytes (P0-ECM). In this study, we investigated bovine chondrocyte functions when being cultured on isolated extracellular matrix (ECM) protein-coated substrata and P0-ECM. Low chondrocyte attachment was observed on aggrecan-coated substratum and P0-ECM. Cell proliferation on aggrecan- and type II collagen/aggrecan-coated substrata and P0-ECM was lower than that on the other ECM protein (type I collagen and type II collagen)-coated substrata. When chondrocytes were subcultured on aggrecan-coated substratum, decline of cartilaginous gene expression was delayed, which was similar to the cells subcultured on P0-ECM. These results indicate that aggrecan plays an important role in the regulation of chondrocyte functions and P0-ECM may be a good experimental control for investigating the role of each ECM protein in cartilage ECM.

  10. Prediction of biopore- and matrix-dominated flow from X-ray CT-derived macropore network characteristics

    Science.gov (United States)

    Naveed, Muhammad; Moldrup, Per; Schaap, Marcel G.; Tuller, Markus; Kulkarni, Ramaprasad; Vogel, Hans-Jörg; Wollesen de Jonge, Lis

    2016-10-01

    conductivity, air permeability, and gas diffusivity performed reasonably well when parameterized with novel, X-ray CT-derived parameters such as effective percolating macroporosity for biopore-dominated flow and total macroporosity for matrix-dominated flow. The obtained results further indicate that it is crucially important to discern between matrix-dominated and biopore-dominated flow for accurate prediction of macropore flow from X-ray CT-derived macropore network characteristics.

  11. Derivation of a new parametric impulse response matrix utilized for nodal wind load identification by response measurement.

    Science.gov (United States)

    Kazemi Amiri, A; Bucher, C

    2015-05-26

    This paper provides new formulations to derive the impulse response matrix, which is then used in the problem of load identification with application to wind induced vibration. The applied loads are inversely identified based on the measured structural responses by solving the associated discrete ill-posed problem. To this end - based on an existing parametric structural model - the impulse response functions of acceleration, velocity and displacement have been computed. Time discretization of convolution integral has been implemented according to an existing and a newly proposed procedure, which differ in the numerical integration methods. The former was evaluated based on a constant rectangular approximation of the sampled data and impulse response function in a number of steps corresponding to the sampling rate, while the latter interpolates the sampled data in an arbitrary number of sub-steps and then integrates over the sub-steps and steps. The identification procedure was implemented for a simulation example as well as an experimental laboratory case. The ill-conditioning of the impulse response matrix made it necessary to use Tikhonov regularization to recover the applied force from noise polluted measured response. The optimal regularization parameter has been obtained by L-curve and GCV method. The results of simulation represent good agreement between identified and measured force. In the experiments the identification results based on the measured displacement as well as acceleration are provided. Further it is shown that the accuracy of experimentally identified load depends on the sensitivity of measurement instruments over the different frequency ranges.

  12. Cultivation of corneal endothelial cells on a pericellular matrix prepared from human decidua-derived mesenchymal cells.

    Directory of Open Access Journals (Sweden)

    Ryohei Numata

    Full Text Available The barrier and pump functions of the corneal endothelium are essential for the maintenance of corneal transparency. Although corneal transplantation is the only current therapy for treating corneal endothelial dysfunction, the potential of tissue-engineering techniques to provide highly efficient and less invasive therapy in comparison to corneal transplantation has been highly anticipated. However, culturing human corneal endothelial cells (HCECs is technically difficult, and there is no established culture protocol. The aim of this study was to investigate the feasibility of using a pericellular matrix prepared from human decidua-derived mesenchymal cells (PCM-DM as an animal-free substrate for HCEC culture for future clinical applications. PCM-DM enhanced the adhesion of monkey CECs (MCECs via integrin, promoted cell proliferation, and suppressed apoptosis. The HCECs cultured on the PCM-DM showed a hexagonal morphology and a staining profile characteristic of Na⁺/K⁺-ATPase and ZO-1 at the plasma membrane in vivo, whereas the control HCECs showed a fibroblastic phenotype. The cell density of the cultured HCECs on the PCM-DM was significantly higher than that of the control cells. These results indicate that PCM-DM provides a feasible xeno-free matrix substrate and that it offers a viable in vitro expansion protocol for HCECs while maintaining cellular functions for use as a subsequent clinical intervention for tissue-engineered based therapy of corneal endothelial dysfunction.

  13. The effect of enamel matrix derivative (Emdogain®) on gene expression profiles of human primary alveolar bone cells.

    Science.gov (United States)

    Yan, X Z; Rathe, F; Gilissen, C; van der Zande, M; Veltman, J; Junker, R; Yang, F; Jansen, J A; Walboomers, X F

    2014-06-01

    Emdogain® is frequently used in regenerative periodontal treatment. Understanding its effect on gene expression of bone cells would enable new products and pathways promoting bone formation to be established. The aim of the study was to analyse the effect of Emdogain® on expression profiles of human-derived bone cells with the help of the micro-array, and subsequent validation. Bone was harvested from non-smoking patients during dental implant surgery. After outgrowth, cells were cultured until subconfluence, treated for 24 h with either Emdogain® (100 µg/ml) or control medium, and subsequently RNA was isolated and micro-array was performed. The most important genes demonstrated by micro-array data were confirmed by qPCR and ELISA tests. Emdogain tipped the balance between genes expressed for bone formation and bone resorption towards a more anabolic effect, by interaction of the PGE2 pathway and inhibition of IL-7 production. In addition the results of the present study indicate that Emdogain possibly has an effect on gene expression for extracellular matrix formation of human bone cells, in particular on bone matrix formation and on proliferation and differentiation. With the micro-array and the subsequent validation, the genes possibly involved in Emdogain action on bone cells were identified. These results can contribute to establishing new products and pathways promoting bone formation.

  14. Cultivation of corneal endothelial cells on a pericellular matrix prepared from human decidua-derived mesenchymal cells.

    Science.gov (United States)

    Numata, Ryohei; Okumura, Naoki; Nakahara, Makiko; Ueno, Morio; Kinoshita, Shigeru; Kanematsu, Daisuke; Kanemura, Yonehiro; Sasai, Yoshiki; Koizumi, Noriko

    2014-01-01

    The barrier and pump functions of the corneal endothelium are essential for the maintenance of corneal transparency. Although corneal transplantation is the only current therapy for treating corneal endothelial dysfunction, the potential of tissue-engineering techniques to provide highly efficient and less invasive therapy in comparison to corneal transplantation has been highly anticipated. However, culturing human corneal endothelial cells (HCECs) is technically difficult, and there is no established culture protocol. The aim of this study was to investigate the feasibility of using a pericellular matrix prepared from human decidua-derived mesenchymal cells (PCM-DM) as an animal-free substrate for HCEC culture for future clinical applications. PCM-DM enhanced the adhesion of monkey CECs (MCECs) via integrin, promoted cell proliferation, and suppressed apoptosis. The HCECs cultured on the PCM-DM showed a hexagonal morphology and a staining profile characteristic of Na⁺/K⁺-ATPase and ZO-1 at the plasma membrane in vivo, whereas the control HCECs showed a fibroblastic phenotype. The cell density of the cultured HCECs on the PCM-DM was significantly higher than that of the control cells. These results indicate that PCM-DM provides a feasible xeno-free matrix substrate and that it offers a viable in vitro expansion protocol for HCECs while maintaining cellular functions for use as a subsequent clinical intervention for tissue-engineered based therapy of corneal endothelial dysfunction.

  15. Extracellular matrix derived from periodontal ligament cells maintains their stemness and enhances redifferentiation via the Wnt pathway.

    Science.gov (United States)

    Zhang, Ji-Chun; Song, Zhong-Chen; Xia, Yi-Ru; Shu, Rong

    2017-09-07

    Large numbers of viable cells cannot be obtained from periodontal ligament tissues of patients with periodontitis. Therefore, it is imperative to establish an ex vivo environment that can support cell proliferation and delay senescence. Here, we have successfully reconstructed a native extracellular matrix (ECM), derived from early-passage human periodontal ligament cells (PDLCs) using the NH4 OH/Triton X-100 protocol. The ECM was investigated by scanning electron microscopy and immunostaining for specific ECM proteins (collagen I and fibronectin). Late-passage ECM-expanded PDLCs exhibited a much higher proliferation index and lower levels of reactive oxygen species (ROS), confirmed by the increased expression of pluripotent markers. and enhanced osteogenic capacity. Interestingly, the Wnt pathway was suppressed during the ECM expansion-mediated increase in pluripotency, but was activated in an osteogenic differentiation environment, as confirmed by treatment with the XAV-939 β-catenin inhibitor or the SP600125 c-Jun N-terminal kinase (JNK) inhibitor. Cell sheets formed by ECM-expanded PDLCs exhibited an enhanced periodontal tissue regeneration capacity compared to those formed on tissue culture polystyrene (TCP) surfaces in vivo. Taken together, the cell-free ECM provides a tissue-specific cell niche for the ex vivo expansion of PDLCs while retaining stemness and osteogenic potential, partially via the Wnt pathway. This represents a promising matrix for future applications in periodontal tissue regeneration therapy. This article is protected by copyright. All rights reserved. © 2017 Wiley Periodicals, Inc.

  16. Tb3+ sensitization in a deoxycholate organogel matrix, and selective quenching of luminescence by an aromatic nitro derivative.

    Science.gov (United States)

    Kandanelli, Ramesh; Sarkar, Anindya; Maitra, Uday

    2013-11-21

    In this article, we present the discovery of a metallo-organogel derived from a Tb(3+) salt and sodium deoxycholate (NaDCh) in methanol. The gel was made luminescent through sensitization of Tb(3+) by doping with 2,3-dihydroxynaphthalene (DHN) in micromolar concentrations. Rheological measurements of the mechanical properties of the organogel confirmed the characteristics of a true gel. Significant quenching of Tb(3+) luminescence was observed in the deoxycholate gel matrix by 2,4,7-trinitrofluorenone (TNF), but not by several other polynitro aromatics. Microscopic studies (AFM, TEM and SEM) revealed a highly entangled fibrous network. The xerogels retained luminescent properties suggesting the possibility for application in coatings, etc.

  17. Effects of CT Number-Derived Matrix Density on Preferential Flow and Transport in Macroporous Agricultural Soil

    DEFF Research Database (Denmark)

    Katuwal, Sheela; Møldrup, Per; Lamande, Mathieu André Maurice;

    2015-01-01

    permeability, saturated hydraulic conductivity, and solute transport. This was due to the limited CT scan resolution and large structural variability below this resolution. However, CTmatrix, a new parameter derived from the CT number of the matrix excluding stones and large mostly air-filled macropores...... risks to public health. This study focused on establishing links between the structural pore space and preferential transport using a combination of standard physical measurement methods for air and water permeabilities, breakthrough experiments, and X-ray computed tomography (CT) on large soil columns....... Substantial structural heterogeneity that resulted in significant variations in flow and tracer transport was observed, despite the textural similarity of the investigated samples. Quantification of macropore characteristics with X-ray CT was useful but not sufficient to explain the variability in air...

  18. The short-term forecasting of wind speed based on EMD and ARMA%基于 HP-EMD 和 ARMA 的短期风速预测

    Institute of Scientific and Technical Information of China (English)

    喻敏; 常毓婵; 袁浩; 赵颖; 周文梦

    2016-01-01

    针对风速为非线性非平稳序列的特点,提出一种基于经验模态分解(empirical mode decomposition ,EMD)和自回归滑动平均模型(auto-regressive moving average model,ARMA)的预测方法。EMD 在对风速序列进行分解时,可能存在模态混叠现象,会影响风速预测精度,为此,提出一种加入高频谐波来抑制模态混叠的方法。首先对风速序列加入高频谐波进行 EMD 分解,获得比原始序列较平稳的子序列,即固有模态函数(intrinsic mode function,IMF),然后利用 ARMA 模型对子序列进行建模预测分析,最后将子序列的预测结果相加得到风速的预测值。和 EMD-ARMA 及直接利用 ARMA 模型进行预测的结果相比,本文所提的方法预测精度更高。%To forecast wind speed within shot-term,this paper proposes a prediction method based on Empirical Mode Decomposi-tion (EMD)and Auto-Regressive Moving Average model (ARMA)for the characteristics of the wind speed as the nonlinear and non-stationary sequence.When wind speed sequence is decomposed by EMD,there may be a mode mixing phenomenon,which will affect the accuracy of wind speed forecasting.Therefore,a method of adding high frequency harmonics to suppress the mode mixing is proposed in this paper.Firstly,high frequency harmonic is added to the wind speed series,then the method uses EMD to decompose it into a series of Intrinsic Mode Functions (IMFS)which are smoother than the original sequence.Secondly,the ARMA model is used to predict the subsequences.Finally,the prediction result of the wind speed is obtained by adding the pre-dicted results of the subsequences.The proposed method is more accurate than the result obtained by directly using EMD-ARMA and ARMA for wind speed sequence.

  19. Prediction Model for Short-term Wind Speed Based on Improved EMD and RBFNN%基于改进EMD 和RBFNN的短期风速预测模型

    Institute of Scientific and Technical Information of China (English)

    尹子中; 陈众; 黄健; 俞晓鹏; 邱强杰; 文亮

    2016-01-01

    In order to improve precision of prediction on short-term wind speed,a prediction model for short-term wind speed combining improved empirical model decomposition (EMD)and radial basis function neural network (RBFNN)is pro-posed.Firstly,extreme point symmetric extension is used for processing on preprocessed wind speed sequences so as to re-strain fringe effect in decomposition caused by traditional EMD,and piecewise cubic Hermite interpolation method is used to solve overshoot or undershoot of traditional EMD envelope lines.Then,improved EMD is used to decompose wind speed se-quences into different intrinsic mode function (IMF)components and respective RBFNN model is constructed for predic-tion.Finally,prediction results of various components are reconstructed and overlayed to get final predicted value of original wind speed.Experimental results indicate that the improved EMD-RBFNN prediction model is able to effectively improve precision of prediction on wind speed and has certain application value.%为提高短期风速预测精度,提出改进经验模态分解法(empirical mode decomposition,EMD)与径向基函数神经网络(radial basis function neural network,RBFNN)相结合的短期风速预测模型。首先,利用极值点对称延拓法对预处理过的风速序列进行处理,以抑制传统EMD在分解过程中所引起的边缘效应,并引用分段三次埃米特插值法解决传统EMD包络线的过冲或欠冲问题;然后,利用改进 EMD 将风速序列分解成各本征模态(in-trinsic mode function,IMF)分量,再针对各分量分别构建各自的 RBFNN 模型进行预测;最后,将各分量的预测结果进行重构、叠加,得到最终的原始风速预测值。实验结果表明,改进的 EMD-RBFNN 预测模型能有效地提高风速预测精度,并具有一定的应用价值。

  20. Polyphosphate induces matrix metalloproteinase-3-mediated proliferation of odontoblast-like cells derived from induced pluripotent stem cells

    Energy Technology Data Exchange (ETDEWEB)

    Ozeki, Nobuaki; Hase, Naoko; Yamaguchi, Hideyuki; Hiyama, Taiki; Kawai, Rie [Department of Endodontics, School of Dentistry, Aichi Gakuin University, 2-11 Suemori-dori, Chikusa-ku, Nagoya, Aichi 464-8651 (Japan); Kondo, Ayami [Department of Medicinal Biochemistry, School of Pharmacy, Aichi Gakuin University, 1-100 Kusumoto, Chikusa-ku, Nagoya 464-8650 (Japan); Nakata, Kazuhiko [Department of Endodontics, School of Dentistry, Aichi Gakuin University, 2-11 Suemori-dori, Chikusa-ku, Nagoya, Aichi 464-8651 (Japan); Mogi, Makio, E-mail: makio@dpc.agu.ac.jp [Department of Medicinal Biochemistry, School of Pharmacy, Aichi Gakuin University, 1-100 Kusumoto, Chikusa-ku, Nagoya 464-8650 (Japan)

    2015-05-01

    Inorganic polyphosphate [Poly(P)] may represent a physiological source of phosphate and has the ability to induce bone differentiation in osteoblasts. We previously reported that cytokine-induced matrix metalloproteinase (MMP)-3 accelerates the proliferation of purified odontoblast-like cells. In this study, MMP-3 small interfering RNA (siRNA) was transfected into odontoblast-like cells derived from induced pluripotent stem cells to investigate whether MMP-3 activity is induced by Poly(P) and/or is associated with cell proliferation and differentiation into odontoblast-like cells. Treatment with Poly(P) led to an increase in both cell proliferation and additional odontoblastic differentiation. Poly(P)-treated cells showed a small but significant increase in dentin sialophosphoprotein (DSPP) and dentin matrix protein-1 (DMP-1) mRNA expression, which are markers of mature odontoblasts. The cells also acquired additional odontoblast-specific properties including adoption of an odontoblastic phenotype typified by high alkaline phosphatase (ALP) activity and a calcification capacity. In addition, Poly(P) induced expression of MMP-3 mRNA and protein, and increased MMP-3 activity. MMP-3 siRNA-mediated disruption of the expression of these effectors potently suppressed the expression of odontoblastic biomarkers ALP, DSPP, and DMP-1, and blocked calcification. Interestingly, upon siRNA-mediated silencing of MMP-3, we noted a potent and significant decrease in cell proliferation. Using specific siRNAs, we revealed that a unique signaling cascade, Poly(P)→MMP-3→DSPP and/or DMP-1, was intimately involved in the proliferation of odontoblast-like cells. - Highlights: • Polyphosphate increases proliferation of iPS cell-derived odontoblast-like cells. • Polyphosphate-induced MMP-3 results in an increase of cell proliferation. • Induced cell proliferation involves MMP-3, DSPP, and/or DMP-1 sequentially. • Induced MMP-3 also results in an increase of odontoblastic

  1. Application of SVM and SVD Technique Based on EMD to the Fault Diagnosis of the Rotating Machinery

    Directory of Open Access Journals (Sweden)

    Junsheng Cheng

    2009-01-01

    Full Text Available Targeting the characteristics that periodic impulses usually occur whilst the rotating machinery exhibits local faults and the limitations of singular value decomposition (SVD techniques, the SVD technique based on empirical mode decomposition (EMD is applied to the fault feature extraction of the rotating machinery vibration signals. The EMD method is used to decompose the vibration signal into a number of intrinsic mode functions (IMFs by which the initial feature vector matrices could be formed automatically. By applying the SVD technique to the initial feature vector matrices, the singular values of matrices could be obtained, which could be used as the fault feature vectors of support vector machines (SVMs classifier. The analysis results from the gear and roller bearing vibration signals show that the fault diagnosis method based on EMD, SVD and SVM can extract fault features effectively and classify working conditions and fault patterns of gears and roller bearings accurately even when the number of samples is small.

  2. Application of EMD-Based SVD and SVM to Coal-Gangue Interface Detection

    Directory of Open Access Journals (Sweden)

    Wei Liu

    2014-01-01

    Full Text Available Coal-gangue interface detection during top-coal caving mining is a challenging problem. This paper proposes a new vibration signal analysis approach to detecting the coal-gangue interface based on singular value decomposition (SVD techniques and support vector machines (SVMs. Due to the nonstationary characteristics in vibration signals of the tail boom support of the longwall mining machine in this complicated environment, the empirical mode decomposition (EMD is used to decompose the raw vibration signals into a number of intrinsic mode functions (IMFs by which the initial feature vector matrices can be formed automatically. By applying the SVD algorithm to the initial feature vector matrices, the singular values of matrices can be obtained and used as the input feature vectors of SVMs classifier. The analysis results of vibration signals from the tail boom support of a longwall mining machine show that the method based on EMD, SVD, and SVM is effective for coal-gangue interface detection even when the number of samples is small.

  3. Earth Mover's Distance (EMD: A True Metric for Comparing Biomarker Expression Levels in Cell Populations.

    Directory of Open Access Journals (Sweden)

    Darya Y Orlova

    Full Text Available Changes in the frequencies of cell subsets that (coexpress characteristic biomarkers, or levels of the biomarkers on the subsets, are widely used as indices of drug response, disease prognosis, stem cell reconstitution, etc. However, although the currently available computational "gating" tools accurately reveal subset frequencies and marker expression levels, they fail to enable statistically reliable judgements as to whether these frequencies and expression levels differ significantly between/among subject groups. Here we introduce flow cytometry data analysis pipeline which includes the Earth Mover's Distance (EMD metric as solution to this problem. Well known as an informative quantitative measure of differences between distributions, we present three exemplary studies showing that EMD 1 reveals clinically-relevant shifts in two markers on blood basophils responding to an offending allergen; 2 shows that ablative tumor radiation induces significant changes in the murine colon cancer tumor microenvironment; and, 3 ranks immunological differences in mouse peritoneal cavity cells harvested from three genetically distinct mouse strains.

  4. The Fault Feature Extraction of Rolling Bearing Based on EMD and Difference Spectrum of Singular Value

    Directory of Open Access Journals (Sweden)

    Te Han

    2016-01-01

    Full Text Available Nowadays, the fault diagnosis of rolling bearing in aeroengines is based on the vibration signal measured on casing, instead of bearing block. However, the vibration signal of the bearing is often covered by a series of complex components caused by other structures (rotor, gears. Therefore, when bearings cause failure, it is still not certain that the fault feature can be extracted from the vibration signal on casing. In order to solve this problem, a novel fault feature extraction method for rolling bearing based on empirical mode decomposition (EMD and the difference spectrum of singular value is proposed in this paper. Firstly, the vibration signal is decomposed by EMD. Next, the difference spectrum of singular value method is applied. The study finds that each peak on the difference spectrum corresponds to each component in the original signal. According to the peaks on the difference spectrum, the component signal of the bearing fault can be reconstructed. To validate the proposed method, the bearing fault data collected on the casing are analyzed. The results indicate that the proposed rolling bearing diagnosis method can accurately extract the fault feature that is submerged in other component signals and noise.

  5. EMDS 3.0: A modeling framework for coping with complexity in environmental assessment and planning

    Institute of Scientific and Technical Information of China (English)

    Keith M. Reynolds

    2006-01-01

    The Ecosystem Management Decision Support (EMDS) system is an application framework for knowledge-based decision support of ecological assessments at any geographic scale. The system integrates state-of-the-art geographic information system(GIS) as well as knowledge-based reasoning and decision modeling technologies to provide decision support for a substantial portion of the adaptive management process of ecosystem management. EMDS 3.0 is implemented as an ArcMap(R) extension and integrates the logic engine of NetWeaver(R) to perform landscape evaluations, and the decision modeling engine of Criterium DecisionPlus(R) for evaluating management priorities. Key features of the system's evaluation component include abilities to (1) reason about large, abstract, multi-faceted ecosystem management problems, (2) perform useful evaluations with incomplete information, (3) evaluate the influence of missing information, and (4)determine priorities for missing information. A key feature of the planning component is the ability to determine priorities for management activities, taking into account not only ecosystem condition, but also criteria that account for the feasibility and efficacy of potential management actions. Both components include powerful and intuitive diagnostic features that facilitate communicating the explanation of modeling results to a broad audience.

  6. Localization of brain activities using multiway analysis of EEG tensor via EMD and reassigned TF representation.

    Science.gov (United States)

    Pouryazdian, Saeed; Beheshti, Soosan; Krishnan, Sridhar

    2015-01-01

    Electroencephalogram (EEG) is widely used for monitoring, diagnosis purposes and also for study of brain's physiological, mental and functional abnormalities. Processing of information by the brain is reflected in dynamical changes of the electrical activity in time, frequency, and space. EEG signal processing tends to describe and quantify these variations in such a way that they are localized in temporal, spectral and spatial domain. Here we use multi-way (Tensor) analysis for localizing the EEG events. We used EMD process for decomposing EEG into distinct oscillatory modes, which are then mapped to TF plane using the near optimal Reassigned Spectrogram. Temporal, Spatial and Spectral information of the Multichannel EEG are then used to generate a three-way Frequency-Time-Space EEG tensor. Exploiting EMD also enables us to detrend the EEG recordings. Simulation results on both synthetic and real EEG data show that tensor analysis greatly improve separation and localization of overlapping events in EEG and it could be effectively exploited for detecting and characterizing the evoked potentials.

  7. Detection of seizure and epilepsy using higher order statistics in the EMD domain.

    Science.gov (United States)

    Alam, S M Shafiul; Bhuiyan, M I H

    2013-03-01

    In this paper, a method using higher order statistical moments of EEG signals calculated in the empirical mode decomposition (EMD) domain is proposed for detecting seizure and epilepsy. The appropriateness of these moments in distinguishing the EEG signals is investigated through an extensive analysis in the EMD domain. An artificial neural network is employed as the classifier of the EEG signals wherein these moments are used as features. The performance of the proposed method is studied using a publicly available benchmark database for various classification cases that include healthy, interictal (seizure-free interval) and ictal (seizure), healthy and seizure, nonseizure and seizure, and interictal and ictal, and compared with that of several recent methods based on time-frequency analysis and statistical moments. It is shown that the proposed method can provide, in almost all the cases, 100% accuracy, sensitivity, and specificity, especially in the case of discriminating seizure activities from the nonseizure ones for patients with epilepsy while being much faster as compared to the time-frequency analysis-based techniques.

  8. The imperatorin derivative OW1, a new vasoactive compound, inhibits VSMC proliferation and extracellular matrix hyperplasia

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Nan; Zhang, Yu; Wang, Tao; He, Jianyu; He, Huaizhen; He, Langchong, E-mail: helc@mail.xjtu.edu.cn

    2015-04-15

    Chronic hypertension induces vascular remodeling. The most important factor for hypertension treatment is reducing the risk of cardiovascular disease. OW1 is a novel imperatorin derivative that exhibits vasodilative activity and antihypertensive effects in two-kidney one-clip (2K1C) renovascular hypertensive rats. It also inhibited vascular remodeling of the thoracic aorta in a previous study. Here, the inhibitory effects and mechanisms of OW1 on arterial vascular remodeling were investigated in vitro and in 2K1C hypertensive rats in vivo. OW1 (20 μM, 10 μM, 5 μM) inhibited Ang II-induced vascular smooth muscle cells (VSMCs) proliferation and ROS generation in vitro. OW1 also reversed the Ang II-mediated inhibition of α-SMA levels and stimulation of OPN levels. Histology results showed that treatment of 2K1C hypertensive rats with OW1 (20, 40, and 80 mg/kg per day, respectively for 5 weeks) in vivo significantly decreased the number of VSMCs, the aortic cross-sectional area (CSA), the media to lumen (M/L) ratio, and the content of collagen I and III in the mesenteric artery. Western blot results also revealed that OW1 stimulated the expression of α-SMA and inhibited the expression of collagen I and III on the thoracic aorta of 2K1C hypertensive rats. In mechanistic studies, OW1 acted as an ACE inhibitor and affected calcium channels. The suppression of MMP expression and the MAPK pathway may account for the effects of OW1 on vascular remodeling. OW1 attenuated vascular remodeling in vitro and in vivo. It could be a novel candidate for hypertension intervention. - Highlights: • OW1, an imperatorin derivative, attenuates vascular remodeling caused by hypertension. • OW1 inhibits VSMC proliferation and media layer hypertrophy. • OW1 acts as an ACE inhibitor and affects calcium channels. • Suppression of MMPs expression and MAPK pathway may account for the effects of OW1 on vascular remodeling.

  9. Speleogenetic effects of interaction between deeply derived fracture-conduit flow and intrastratal matrix flow in hypogene karst settings

    Directory of Open Access Journals (Sweden)

    Tymokhina Elizaveta

    2012-07-01

    Full Text Available In carbonate rocks, especially in those with high primary porosity such as most Cenozoic carbonates, the interaction between deeply derived rising flow through sub-vertical fracture-controlled conduits and intrastratal matrix flow of shallower systems can invoke mixing cor- rosion and result in prominent speleogenetic effects. This paper outlines a conceptual model of such interaction and provides instructive field examples of relevant morphological effects from two different regions within the Prichernomorsky (north Black Sea basin, where karst features are developed in lower Pliocene, Eocene and Paleocene limestones. In the Crimean fore-mountain region, extensive steep to ver- tical limestone scarps formed through recent exposure of hypogenic fracture-controlled conduits provide outstanding possibilities to directly examine details of the original karstic porosity. The morphological effects of the conduit/matrix interaction, documented in both caves and exposed scarps, include lateral widening of sub-vertical conduits within the interaction intervals (formation of lateral notches and niches and the development of side bedding-parallel conduits, pockets and vuggy-spongework zones. Natural convection circulation, invoked by interaction of the two flow systems, spreads the morphological effects throughout the conduit space above the interaction interval. Where the interaction of the two flow systems is particularly strongly localized, such as along junctions of two vertical fracture sets, the resultant morphological effect can take the form of isolated chambers. The variety of speleogenetic features developed through the conduit/matrix interaction, can be broadly grouped into two categories: 1 variously shaped swells of the major fracture conduit itself (morphological fea- tures of its walls – niches and pockets, and 2 features of the vuggy-spongework halo surrounding the conduit. This halo includes clustered and stratiform cavities, spongework

  10. Artifact reduction in multichannel pervasive EEG using hybrid WPT-ICA and WPT-EMD signal decomposition techniques

    CERN Document Server

    Bono, Valentina; Das, Saptarshi; Maharatna, Koushik

    2014-01-01

    In order to reduce the muscle artifacts in multi-channel pervasive Electroencephalogram (EEG) signals, we here propose and compare two hybrid algorithms by combining the concept of wavelet packet transform (WPT), empirical mode decomposition (EMD) and Independent Component Analysis (ICA). The signal cleaning performances of WPT-EMD and WPT-ICA algorithms have been compared using a signal-to-noise ratio (SNR)-like criterion for artifacts. The algorithms have been tested on multiple trials of four different artifact cases viz. eye-blinking and muscle artifacts including left and right hand movement and head-shaking.

  11. Schwinger-Dyson operator of Yang-Mills matrix models with ghosts and derivations of the graded shuffle algebra

    Energy Technology Data Exchange (ETDEWEB)

    Krishnaswami, Govind S [Institute for Theoretical Physics and Spinoza Institute, Utrecht University, Postbus 80.195, 3508 TD, Utrecht (Netherlands)], E-mail: govind.krishnaswami@durham.ac.uk

    2008-04-11

    We consider large-N multi-matrix models whose action closely mimics that of Yang-Mills theory, including gauge-fixing and ghost terms. We show that the factorized Schwinger-Dyson loop equations, expressed in terms of the generating series of gluon and ghost correlations G({xi}), are quadratic equations S{sup i}G=G{xi}{sup i}G in concatenation of correlations. The Schwinger-Dyson operator S{sup i} is built from the left annihilation operator, which does not satisfy the Leibnitz rule with respect to concatenation. So the loop equations are not differential equations. We show that left annihilation is a derivation of the graded shuffle product of gluon and ghost correlations. The shuffle product is the point-wise product of Wilson loops, expressed in terms of correlations. So in the limit where concatenation is approximated by shuffle products, the loop equations become differential equations. Remarkably, the Schwinger-Dyson operator as a whole is also a derivation of the graded shuffle product. This allows us to turn the loop equations into linear equations for the shuffle reciprocal, which might serve as a starting point for an approximation scheme.

  12. The generation of hybrid electrospun nanofiber layer with extracellular matrix derived from human pluripotent stem cells, for regenerative medicine applications.

    Science.gov (United States)

    Shtrichman, Ronit; Zeevi-Levin, Naama; Zaid, Rinat; Barak, Efrat; Fishman, Bettina; Ziskind, Anna; Shulman, Rita; Novak, Atara; Avrahami, Ron; Livne, Erella; Lowenstein, Lior; Zussman, Eyal; Itskovitz-Eldor, Joseph

    2014-10-01

    Extracellular matrix (ECM) has been utilized as a biological scaffold for tissue engineering applications in a variety of body systems, due to its bioactivity and biocompatibility. In the current study we developed a modified protocol for the efficient and reproducible derivation of mesenchymal progenitor cells (MPCs) from human embryonic stem cells as well as human induced pluripotent stem cells (hiPSCs) originating from hair follicle keratinocytes (HFKTs). ECM was produced from these MPCs and characterized in comparison to adipose mesenchymal stem cell ECM, demonstrating robust ECM generation by the excised HFKT-iPSC-MPCs. Exploiting the advantages of electrospinning we generated two types of electrospun biodegradable nanofiber layers (NFLs), fabricated from polycaprolactone (PCL) and poly(lactic-co-glycolic acid) (PLGA), which provide mechanical support for cell seeding and ECM generation. Elucidating the optimized decellularization treatment we were able to generate an available "off-the-shelf" implantable product (NFL-ECM). Using rat subcutaneous transplantation model we demonstrate that this stem-cell-derived construct is biocompatible and biodegradable and holds great potential for tissue regeneration applications.

  13. TCDD induces dermal accumulation of keratinocyte-derived matrix metalloproteinase-10 in an organotypic model of human skin.

    Science.gov (United States)

    De Abrew, K Nadira; Thomas-Virnig, Christina L; Rasmussen, Cathy A; Bolterstein, Elyse A; Schlosser, Sandy J; Allen-Hoffmann, B Lynn

    2014-05-01

    The epidermis of skin is the first line of defense against the environment. A three dimensional model of human skin was used to investigate tissue-specific phenotypes induced by the environmental contaminant, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Continuous treatment of organotypic cultures of human keratinocytes with TCDD resulted in intracellular spaces between keratinocytes of the basal and immediately suprabasal layers as well as thinning of the basement membrane, in addition to the previously reported hyperkeratinization. These tissue remodeling events were preceded temporally by changes in expression of the extracellular matrix degrading enzyme, matrix metalloproteinase-10 (MMP-10). In organotypic cultures MMP-10 mRNA and protein were highly induced following TCDD treatment. Q-PCR and immunoblot results from TCDD-treated monolayer cultures, as well as indirect immunofluorescence and immunoblot analysis of TCDD-treated organotypic cultures, showed that MMP-10 was specifically contributed by the epidermal keratinocytes but not the dermal fibroblasts. Keratinocyte-derived MMP-10 protein accumulated over time in the dermal compartment of organotypic cultures. TCDD-induced epidermal phenotypes in organotypic cultures were attenuated by the keratinocyte-specific expression of tissue inhibitor of metalloproteinase-1, a known inhibitor of MMP-10. These studies suggest that MMP-10 and possibly other MMP-10-activated MMPs are responsible for the phenotypes exhibited in the basement membrane, the basal keratinocyte layer, and the cornified layer of TCDD-treated organotypic cultures. Our studies reveal a novel mechanism by which the epithelial-stromal microenvironment is altered in a tissue-specific manner thereby inducing structural and functional pathology in the interfollicular epidermis of human skin.

  14. Cooperative effects in differentiation and proliferation between PDGF-BB and matrix derived synthetic peptides in human osteoblasts

    Directory of Open Access Journals (Sweden)

    Vordemvenne Thomas

    2011-11-01

    Full Text Available Abstract Background Enhancing osteogenic capabilities of bone matrix for the treatment of fractures and segmental defects using growth factors is an active area of research. Recently, synthetic peptides like AC- 100, TP508 or p-15 corresponding to biologically active sequences of matrix proteins have been proven to stimulate bone formation. The platelet-derived growth factor (PDGF BB has been identified as an important paracrine factor in early bone healing. We hypothesized that the combined use of PDGF-BB with synthetic peptides could result in an increase in proliferation and calcification of osteoblast-like cells. Methods Osteoblast-like cell cultures were treated with PDGF and synthetic peptides, singly and as combinations, and compared to non-treated control cell cultures. The cultures were evaluated at days 2, 5, and 10 in terms of cell proliferation, calcification and gene expression of alkaline phosphate, collagen I and osteocalcin. Results Experimental findings revealed that the addition of PDGF, p-15 and TP508 and combinations of PDGF/AC-100, PDGF/p-15 and PDGF/TP508 resulted in an increase in proliferating osteoblasts, especially in the first 5 days of cultivation. Proliferation did not significantly differ between single factors and factor combinations (p > 0.05. The onset of calcification in osteoblasts occurred earlier and was more distinct compared to the corresponding control or PDGF stimulation alone. Significant difference was found for the combined use of PDGF/p-15 and PDGF/AC-100 (p Conclusions Our findings indicate that PDGF exhibits cooperative effects with synthetic peptides in differentiation and proliferation. These cooperative effects cause a significant early calcification of osteoblast-like cells (p

  15. TCDD induces dermal accumulation of keratinocyte-derived matrix metalloproteinase-10 in an organotypic model of human skin

    Energy Technology Data Exchange (ETDEWEB)

    De Abrew, K. Nadira [Molecular and Environmental Toxicology Center, University of Wisconsin—Madison, Madison, WI 53706 (United States); Thomas-Virnig, Christina L.; Rasmussen, Cathy A. [Department of Pathology, University of Wisconsin—Madison, Madison, WI 53706 (United States); Bolterstein, Elyse A. [Molecular and Environmental Toxicology Center, University of Wisconsin—Madison, Madison, WI 53706 (United States); Schlosser, Sandy J. [Department of Pathology, University of Wisconsin—Madison, Madison, WI 53706 (United States); Allen-Hoffmann, B. Lynn, E-mail: blallenh@wisc.edu [Molecular and Environmental Toxicology Center, University of Wisconsin—Madison, Madison, WI 53706 (United States); Department of Pathology, University of Wisconsin—Madison, Madison, WI 53706 (United States)

    2014-05-01

    The epidermis of skin is the first line of defense against the environment. A three dimensional model of human skin was used to investigate tissue-specific phenotypes induced by the environmental contaminant, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Continuous treatment of organotypic cultures of human keratinocytes with TCDD resulted in intracellular spaces between keratinocytes of the basal and immediately suprabasal layers as well as thinning of the basement membrane, in addition to the previously reported hyperkeratinization. These tissue remodeling events were preceded temporally by changes in expression of the extracellular matrix degrading enzyme, matrix metalloproteinase-10 (MMP-10). In organotypic cultures MMP-10 mRNA and protein were highly induced following TCDD treatment. Q-PCR and immunoblot results from TCDD-treated monolayer cultures, as well as indirect immunofluorescence and immunoblot analysis of TCDD-treated organotypic cultures, showed that MMP-10 was specifically contributed by the epidermal keratinocytes but not the dermal fibroblasts. Keratinocyte-derived MMP-10 protein accumulated over time in the dermal compartment of organotypic cultures. TCDD-induced epidermal phenotypes in organotypic cultures were attenuated by the keratinocyte-specific expression of tissue inhibitor of metalloproteinase-1, a known inhibitor of MMP-10. These studies suggest that MMP-10 and possibly other MMP-10-activated MMPs are responsible for the phenotypes exhibited in the basement membrane, the basal keratinocyte layer, and the cornified layer of TCDD-treated organotypic cultures. Our studies reveal a novel mechanism by which the epithelial–stromal microenvironment is altered in a tissue-specific manner thereby inducing structural and functional pathology in the interfollicular epidermis of human skin. - Highlights: • TCDD causes hyperkeratosis and basement membrane changes in a model of human skin. • TCDD induces MMP-10 expression in organotypic cultures

  16. Culturing on decellularized extracellular matrix enhances antioxidant properties of human umbilical cord-derived mesenchymal stem cells

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Xiaozhen [School of Engineering, Sun Yat-sen University, Guangzhou 510006 (China); Zhou, Long; Chen, Xi [Orthopaedic Institute, Soochow University, Suzhou 215007 (China); Department of Orthopaedics, The First Affiliated Hospital of Soochow University, Suzhou 215006 (China); Liu, Tao [Department of Orthopaedics, The First Affiliated Hospital of Soochow University, Suzhou 215006 (China); Pan, Guoqing; Cui, Wenguo; Li, Mao; Luo, Zong-Ping [Orthopaedic Institute, Soochow University, Suzhou 215007 (China); Department of Orthopaedics, The First Affiliated Hospital of Soochow University, Suzhou 215006 (China); Pei, Ming [Stem Cell and Tissue Engineering Laboratory, Department of Orthopaedics, West Virginia University, Morgantown, WV 26506 (United States); Yang, Huilin [Orthopaedic Institute, Soochow University, Suzhou 215007 (China); Department of Orthopaedics, The First Affiliated Hospital of Soochow University, Suzhou 215006 (China); Gong, Yihong, E-mail: gongyih@mail.sysu.edu.cn [School of Engineering, Sun Yat-sen University, Guangzhou 510006 (China); He, Fan, E-mail: fanhe@suda.edu.cn [Orthopaedic Institute, Soochow University, Suzhou 215007 (China); Department of Orthopaedics, The First Affiliated Hospital of Soochow University, Suzhou 215006 (China)

    2016-04-01

    Human umbilical cord-derived mesenchymal stem cells (UC-MSCs) have attracted great interest in clinical application because of their regenerative potential and their lack of ethical issues. Our previous studies showed that decellularized cell-deposited extracellular matrix (ECM) provided an in vivo-mimicking microenvironment for MSCs and facilitated in vitro cell expansion. This study was conducted to analyze the cellular response of UC-MSCs when culturing on the ECM, including reactive oxygen species (ROS), intracellular antioxidative enzymes, and the resistance to exogenous oxidative stress. After decellularization, the architecture of cell-deposited ECM was characterized as nanofibrous, collagen fibrils and the matrix components were identified as type I and III collagens, fibronectin, and laminin. Compared to tissue culture polystyrene (TCPS) plates, culturing on ECM yielded a 2-fold increase of UC-MSC proliferation and improved the percentage of cells in the S phase by 2.4-fold. The levels of intracellular ROS and hydrogen peroxide (H{sub 2}O{sub 2}) in ECM-cultured cells were reduced by 41.7% and 82.9%, respectively. More importantly, ECM-cultured UC-MSCs showed enhanced expression and activity of intracellular antioxidative enzymes such as superoxide dismutase and catalase, up-regulated expression of silent information regulator type 1, and suppressed phosphorylation of p38 mitogen-activated protein kinase. Furthermore, a continuous treatment with exogenous 100 μM H{sub 2}O{sub 2} dramatically inhibited osteogenic differentiation of UC-MSCs cultured on TCPS, but culturing on ECM retained the differentiation capacity for matrix mineralization and osteoblast-specific marker gene expression. Collectively, by providing sufficient cell amounts and enhancing antioxidant capacity, decellularized ECM can be a promising cell culture platform for in vitro expansion of UC-MSCs. - Highlights: • Decellularization preserved the architecture and components of cell

  17. The recognition of ocean red tide with hyper-spectral-image based on EMD

    Institute of Scientific and Technical Information of China (English)

    ZHAO Wencang; WEI Hongli; SHI Changjiang; JI Guangrong

    2008-01-01

    A new technique is introduced in this paper regarding red tide recognition with remotely sensed hyper-spectral images based on empirical mode decomposition (EMD),from an artificial red tide experiment in the East China Sea in 2002.A set of characteristic parameters that describe absorbing crest and reflecting crest of the red tide and its recognition methods are put forward based on general picture data,with which the spectral information of certain non-dominant alga species of a red tide occurrence is analyzed for establishing the foundation to estimate the species.Comparative experiments have proved that the method is effective.Meanwhile,the transitional area between red-tide zone and non-red-tide zone can be detected with the information of thickness of algae influence,with which a red tide can be forecast.

  18. Feature Identification and Filtering for Engine Misfire Detection (EMD) Using Zirconia Oxygen Sensor

    Science.gov (United States)

    Pauzi, Muhammad Zaim Mohamed; Abu Bakar, Elmi; Fauzi Ismail, Mohd

    2016-02-01

    Vehicles as transportation are popular and mainly use among peoples around the world for various kind of purpose either personal or not. Over hundreds of year internal combustion engines widely used because of high efficiency and low maintenance compare to new technology which are using cells of battery. Nevertheless, emission cause of incomplete combustion such engine misfire normally occurs as well. For instances, some mechanical, sensors or actuators failure and environmental condition contribute to the engine misfire. The importance of engine misfire detection (EMD) is to ensure engine emissions not harmful to the environments and avoid damage of catalytic converter. By using low cost narrowband oxygen sensor to acquire air to fuel ratio (AFR) signal behavior under misfire condition and analyst by digital signal processing method using Discrete Fourier Transform (DFT) algorithm for Digital Butterworth Filter designation is discussed in this paper.

  19. Unique proliferation response in odontoblastic cells derived from human skeletal muscle stem cells by cytokine-induced matrix metalloproteinase-3

    Energy Technology Data Exchange (ETDEWEB)

    Ozeki, Nobuaki; Hase, Naoko; Kawai, Rie; Yamaguchi, Hideyuki; Hiyama, Taiki [Department of Endodontics, School of Dentistry, Aichi Gakuin University, 2-11 Suemori-dori, Chikusa-ku, Nagoya 464-8651, Aichi (Japan); Kondo, Ayami [Department of Medicinal Biochemistry, School of Pharmacy, Aichi Gakuin University, 1-100 Kusumoto, Chikusa-ku, Nagoya 464-8650 (Japan); Nakata, Kazuhiko [Department of Endodontics, School of Dentistry, Aichi Gakuin University, 2-11 Suemori-dori, Chikusa-ku, Nagoya 464-8651, Aichi (Japan); Mogi, Makio, E-mail: makio@dpc.agu.ac.jp [Department of Medicinal Biochemistry, School of Pharmacy, Aichi Gakuin University, 1-100 Kusumoto, Chikusa-ku, Nagoya 464-8650 (Japan)

    2015-02-01

    A pro-inflammatory cytokine mixture (CM: interleukin (IL)-1β, tumor necrosis factor-α and interferon-γ) and IL-1β-induced matrix metalloproteinase (MMP)-3 activity have been shown to increase the proliferation of rat dental pulp cells and murine stem cell-derived odontoblast-like cells. This suggests that MMP-3 may regulate wound healing and regeneration in the odontoblast-rich dental pulp. Here, we determined whether these results can be extrapolated to human dental pulp by investigating the effects of CM-induced MMP-3 up-regulation on the proliferation and apoptosis of purified odontoblast-like cells derived from human skeletal muscle stem cells. We used siRNA to specifically reduce MMP-3 expression. We found that CM treatment increased MMP-3 mRNA and protein levels as well as MMP-3 activity. Cell proliferation was also markedly increased, with no changes in apoptosis, upon treatment with CM and following the application of exogenous MMP-3. Endogenous tissue inhibitors of metalloproteinases were constitutively expressed during all experiments and unaffected by MMP-3. Although treatment with MMP-3 siRNA suppressed cell proliferation, it also unexpectedly increased apoptosis. This siRNA-mediated increase in apoptosis could be reversed by exogenous MMP-3. These results demonstrate that cytokine-induced MMP-3 activity regulates cell proliferation and suppresses apoptosis in human odontoblast-like cells. - Highlights: • Pro-inflammatory cytokines induce MMP-3 activity in human odontoblast-like cells. • Increased MMP-3 activity can promote cell proliferation in odontoblasts. • Specific loss of MMP-3 increases apoptosis in odontoblasts. • MMP-3 has potential as a promising new target for pupal repair and regeneration.

  20. An Autologous Bone Marrow Mesenchymal Stem Cell–Derived Extracellular Matrix Scaffold Applied with Bone Marrow Stimulation for Cartilage Repair

    Science.gov (United States)

    Tang, Cheng; Jin, Chengzhe; Du, Xiaotao; Yan, Chao; Min, Byoung-Hyun; Xu, Yan

    2014-01-01

    Purpose: It is well known that implanting a bioactive scaffold into a cartilage defect site can enhance cartilage repair after bone marrow stimulation (BMS). However, most of the current scaffolds are derived from xenogenous tissue and/or artificial polymers. The implantation of these scaffolds adds risks of pathogen transmission, undesirable inflammation, and other immunological reactions, as well as ethical issues in clinical practice. The current study was undertaken to evaluate the effectiveness of implanting autologous bone marrow mesenchymal stem cell–derived extracellular matrix (aBMSC-dECM) scaffolds after BMS for cartilage repair. Methods: Full osteochondral defects were performed on the trochlear groove of both knees in 24 rabbits. One group underwent BMS only in the right knee (the BMS group), and the other group was treated by implantation of the aBMSC-dECM scaffold after BMS in the left knee (the aBMSC-dECM scaffold group). Results: Better repair of cartilage defects was observed in the aBMSC-dECM scaffold group than in the BMS group according to gross observation, histological assessments, immunohistochemistry, and chemical assay. The glycosaminoglycan and DNA content, the distribution of proteoglycan, and the distribution and arrangement of type II and I collagen fibers in the repaired tissue in the aBMSC-dECM scaffold group at 12 weeks after surgery were similar to that surrounding normal hyaline cartilage. Conclusions: Implanting aBMSC-dECM scaffolds can enhance the therapeutic effect of BMS on articular cartilage repair, and this combination treatment is a potential method for successful articular cartilage repair. PMID:24666429

  1. Regeneration of Cartilage in Human Knee Osteoarthritis with Autologous Adipose Tissue-Derived Stem Cells and Autologous Extracellular Matrix

    Directory of Open Access Journals (Sweden)

    Jaewoo Pak

    2016-08-01

    Full Text Available This clinical case series demonstrates that percutaneous injections of autologous adipose tissue-derived stem cells (ADSCs and homogenized extracellular matrix (ECM in the form of adipose stromal vascular fraction (SVF, along with hyaluronic acid (HA and platelet-rich plasma (PRP activated by calcium chloride, could regenerate cartilage-like tissue in human knee osteoarthritis (OA patients. Autologous lipoaspirates were obtained from adipose tissue of the abdominal origin. Afterward, the lipoaspirates were minced to homogenize the ECM. These homogenized lipoaspirates were then mixed with collagenase and incubated. The resulting mixture of ADSCs and ECM in the form of SVF was injected, along with HA and PRP activated by calcium chloride, into knees of three Korean patients with OA. The same affected knees were reinjected weekly with additional PRP activated by calcium chloride for 3 weeks. Pretreatment and post-treatment magnetic resonance imaging (MRI data, functional rating index, range of motion (ROM, and pain score data were then analyzed. All patients' MRI data showed cartilage-like tissue regeneration. Along with MRI evidence, the measured physical therapy outcomes in terms of ROM, subjective pain, and functional status were all improved. This study demonstrates that percutaneous injection of ADSCs with ECM contained in autologous adipose SVF, in conjunction with HA and PRP activated by calcium chloride, is a safe and potentially effective minimally invasive therapy for OA of human knees.

  2. The Promoting Effect of the Extracellular Matrix Peptide TNIIIA2 Derived from Tenascin-C in Colon Cancer Cell Infiltration

    Science.gov (United States)

    Suzuki, Hideo; Sasada, Manabu; Kamiya, Sadahiro; Ito, Yuka; Watanabe, Hikaru; Okada, Yuko; Ishibashi, Kazuma; Iyoda, Takuya; Yanaka, Akinori; Fukai, Fumio

    2017-01-01

    The extracellular matrix (ECM) molecule tenascin C (TNC) is known to be highly expressed under various pathological conditions such as inflammation and cancer. It has been reported that the expression of TNC is correlated with the malignant potential of cancer. In our laboratory, it was found that the peptide derived from the alternative splicing domain A2 in TNC, termed TNIIIA2, has been shown to influence a variety of cellular processes, such as survival, proliferation, migration, and differentiation. In this study, we investigated the effect of TNC/TNIIIA2 on the invasion and metastasis of colon cancer cells, Colon26-M3.1, or PMF-Ko14, using an in vitro and in vivo experimental system. The degree of cell invasion was increased by the addition of TNC and TNIIIA2 in a dose-dependent manner. The invasion by TNC and TNIIIA2 were suppressed by an MMP inhibitor or TNIIIA2-blocking antibody. In an in vivo experiment, pulmonary metastasis was promoted conspicuously by the addition of TNIIIA2. In this study, we found that colon cancer cell invasion and metastasis was accelerated by TNC/TNIIIA2 via MMP induction. This result suggests the possibility of a new strategy targeting TNC/TNIIIA2 for colon cancer. PMID:28106752

  3. Tissue Inhibitor of Matrix Metalloproteinases-1 Knockdown Suppresses the Proliferation of Human Adipose-Derived Stem Cells

    Directory of Open Access Journals (Sweden)

    Peihua Zhang

    2016-01-01

    Full Text Available Tissue inhibitor of metalloproteinases-1 (TIMP-1 is a multifunctional matrix metalloproteinase, and it is involved in the regulation of cell proliferation and apoptosis in various cell types. However, little is known about the effect of TIMP-1 expression on the proliferation of adipose-derived stem cells (ADSCs. Therefore, TIMP-1 expression in the ADSCs was firstly detected by western blotting, and TIMP-1 gene was knocked down by lentivirus-mediated shRNA. Cell proliferation was then evaluated by MTT assay and Ki67 staining, respectively. Cell cycle progression was determined by flow cytometry. The changes of p51, p21, cyclin E, cyclin-dependent kinase 2 (CDK2, and P-CDK2 caused by TIMP-1 knockdown were detected by western blotting. The results indicated that ADSCs highly expressed TIMP-1 protein, and the knockdown of TIMP-1 inhibited cell proliferation and arrested cell cycle progression at G1 phase in the ADSCs possibly through the upregulation of p53, p21, and P-CDK2 protein levels and concurrent downregulation of cyclin E and CDK2 protein levels. These findings suggest that TIMP-1 works as a positive regulator of cell proliferation in ADSCs.

  4. The ginsenoside derivative 20(S)-protopanaxadiol inhibits solar ultraviolet light-induced matrix metalloproteinase-1 expression.

    Science.gov (United States)

    Han, Eungmin; Lim, Tae-Gyu; Kim, Jong-Eun; Yang, Hee; Oh, Deok-Kun; Yoon Park, Jung Han; Yoon Park, Dalius; Kim, Hee Jung; Rhee, Young Kyoung; Lee, Ki Won

    2017-04-05

    Ginsenosides are major pharmacologically active compounds present in ginseng (Panax ginseng). Among the ginsenosides, 20-O-β-D-glucopyranosyl-20(S)-protopanaxadiol (GPPD) and ginsenoside Rb1 (Rb1) have previously been reported to exhibit anti-wrinkle effects. In this study, 20(S)-protopanaxadiol (20(S)-PPD), an aglycone derivative of the Rb1 metabolite was investigated for its anti-wrinkle benefit and compared to GPPD and Rb1. The anti-wrinkle effect of 20(S)-PPD during solar UV light was investigated using a human skin equivalent model and human keratinocytes. 20(S)-PPD attenuated solar UV-induced matrix metalloproteinase (MMP)-1 expression to a greater extent than GPPD and Rb1. 20(S)-PPD treatment modulated MMP-1 mRNA expression and the transcriptional activity of activator protein (AP)-1, a major transcription factor of MMP-1. Two upstream signaling pathways for AP-1, the MEK1/2-ERK1/2-p90(RSK) and MEK3/6-p38 pathways, were also suppressed. Taken together, these findings highlight the potential of 20(S)-PPD for further development as a preventative agent for sunlight-induced skin wrinkle. This article is protected by copyright. All rights reserved.

  5. 基于EMD-SVD模型和SVM滚动轴承故障模式识别%Fault Pattern Recognition of Rolling Bearing Based on EMD-SVD Model and SVM

    Institute of Scientific and Technical Information of China (English)

    吴虎胜; 吕建新; 来凌红; 吴庐山; 朱玉荣

    2011-01-01

    针对滚动轴承振动信号的非平稳特性和在现实条件下难以获取大量故障样本的实际情况,提出一种经验模态分解、奇异值分解、Renyi熵和支持向量机相结合的故障诊断方法.运用经验模态分解方法对其去噪信号进行分析,利用互相关系数准则对固有模式分量进行筛选,再对所选分量重构相空间得到吸引子轨道矩阵;对矩阵进行奇异值分解求取奇异值,再计算这些奇异值的Renyi熵以组成故障特征向量,并将其作为支持向量机的输入以识别滚动轴承的故障类型.最后,利用实际滚动轴承试验数据的诊断与对比试验验证了该方法的有效性和泛化能力.%According to the non-stationarity characteristics of the vibration signals from rolling bearing and the difficulty for obtaining enough fault samples, a comprehensive fault diagnosis method based on Empirical Mode Decomposition (EMD),Singularity Value Decomposition (SVD), Renyi-entropy and Support Sector Machine (SVM) is proposed.Firstly, the denoised vibration signals are decomposed into a finite number of Intrinsic Mode Functions (IMF).Secondly, some IMF components are selected according to the criterion of mutual correlation coefficient between IMF components and denoised signal.Thirdly, the phase space of the selected IMF components is reconstructed so as to obtain the attractor orbit matrix.Fourthly, with the SVD method, singular value sequences are obtained, and then Renyi-entropies of these sequences are calculated as faulty eigenvector.Finally, the eigenvector serves as input of SVM classifier so that the faults of rolling bearing are recognized.Practical rolling bearing experiment data is used to verify this method, and the diagnosis results and comparative tests fully validate its effectiveness and generalization ability.

  6. Matrix-derived combination effects influencing absorption, distribution, metabolism and excretion (ADME) of food-borne toxic compounds: implications for risk assessment

    NARCIS (Netherlands)

    Rietjens, I.; Tyrakowska, B.; Berg, van den S.J.P.L.; Soffers, A.E.M.F.; Punt, A.

    2015-01-01

    Absorption, distribution, metabolism and excretion (ADME) of food-borne toxic compounds may be influenced by other compounds or constituents present in the food. The present review presents an overview of evidence currently available on food matrix-derived combination effects influencing the ADME ch

  7. Cytocompatibility of novel extracellular matrix protein analogs of biodegradable polyester polymers derived from α-hydroxy amino acids.

    Science.gov (United States)

    Lecht, Shimon; Cohen-Arazi, Naomi; Cohen, Gadi; Ettinger, Keren; Momic, Tatjana; Kolitz, Michal; Naamneh, Majdi; Katzhendler, Jehoshua; Domb, Abraham J; Lazarovici, Philip; Lelkes, Peter I

    2014-01-01

    One of the challenges in regenerative medicine is the development of novel biodegradable materials to build scaffolds that will support multiple cell types for tissue engineering. Here we describe the preparation, characterization, and cytocompatibility of homo- and hetero-polyesters of α-hydroxy amino acid derivatives with or without lactic acid conjugation. The polymers were prepared by a direct condensation method and characterized using gel permeation chromatography, (1)H-nuclear magnetic resonance spectroscopy, Fourier transform infrared spectroscopy, differential scanning calorimetry, optical activity, and solubility. The surface charge of the polymers was evaluated using zeta potential measurements. The polymers were coated onto glass cover slips followed by characterization using nano-surface profiler, thin film reflectometry, and atomic force microscopy (AFM). Their interaction with endothelial and neuronal cells was assessed using adhesion, proliferation, and differentiation assays. Of the characterized polymers, Poly-HOVal-LA, but not Poly-(D)HOPhe, significantly augmented nerve growth factor (NGF)-induced neuronal differentiation of the PC12 pheochromcytoma cells. In contrast, Poly-HOLeu increased by 20% the adhesion of endothelial cells, but did not affect PC12 cell differentiation. NGF-induced Erk1/2 phosphorylation in PC12 cells grown on the different polymers was similar to the effect observed for cells cultured on collagen type I. While no significant association could be established between charge and the differentiative/proliferative properties of the polymers, AFM analysis indicated augmentation of NGF-induced neuronal differentiation on smooth polymer surfaces. We conclude that overall selective cytocompatibility and bioactivity might render α-hydroxy amino acid polymers useful as extracellular matrix-mimicking materials for tissue engineering.

  8. Structural basis for matrix metalloproteinase-2 (MMP-2)-selective inhibitory action of β-amyloid precursor protein-derived inhibitor.

    Science.gov (United States)

    Hashimoto, Hiroshi; Takeuchi, Tomoka; Komatsu, Kyoko; Miyazaki, Kaoru; Sato, Mamoru; Higashi, Shouichi

    2011-09-23

    Unlike other synthetic or physiological inhibitors for matrix metalloproteinases (MMPs), the β-amyloid precursor protein-derived inhibitory peptide (APP-IP) having an ISYGNDALMP sequence has a high selectivity toward MMP-2. Our previous study identified amino acid residues of MMP-2 essential for its selective inhibition by APP-IP and demonstrated that the N to C direction of the decapeptide inhibitor relative to the substrate-binding cleft of MMP-2 is opposite that of substrate. However, detailed interactions between the two molecules remained to be clarified. Here, we determined the crystal structure of the catalytic domain of MMP-2 in complex with APP-IP. We found that APP-IP in the complex is indeed embedded into the substrate-binding cleft of the catalytic domain in the N to C direction opposite that of substrate. With the crystal structure, it was first clarified that the aromatic side chain of Tyr(3) of the inhibitor is accommodated into the S1' pocket of the protease, and the carboxylate group of Asp(6) of APP-IP coordinates bidentately to the catalytic zinc of the enzyme. The Ala(7) to Pro(10) and Tyr(3) to Ile(1) strands of the inhibitor extend into the nonprime and the prime sides of the cleft, respectively. Therefore, the decapeptide inhibitor has long range contact with the substrate-binding cleft of the protease. This mode of interaction is probably essential for the high MMP-2 selectivity of the inhibitor because MMPs share a common architecture in the vicinity of the catalytic center, but whole structures of their substrate-binding clefts have sufficient variety for the inhibitor to distinguish MMP-2 from other MMPs.

  9. Tendon tissue engineering: adipose-derived stem cell and GDF-5 mediated regeneration using electrospun matrix systems

    Energy Technology Data Exchange (ETDEWEB)

    James, R [Department of Biomedical Engineering, University of Virginia, Charlottesville, VA 22908 (United States); Kumbar, S G; Laurencin, C T [Department of Orthopaedic Surgery, University of Connecticut Health Center, Farmington, CT 06030 (United States); Balian, G; Chhabra, A B, E-mail: ac2h@hscmail.mcc.virginia.edu [Department of Orthopaedic Surgery, University of Virginia, Charlottesville, VA 22908 (United States)

    2011-04-15

    Tendon tissue engineering with a biomaterial scaffold that mimics the tendon extracellular matrix (ECM) and is biomechanically suitable, and when combined with readily available autologous cells, may provide successful regeneration of defects in tendon. Current repair strategies using suitable autografts and freeze-dried allografts lead to a slow repair process that is sub-optimal and fails to restore function, particularly in difficult clinical situations such as zone II flexor tendon injuries of the hand. We have investigated the effect of GDF-5 on cell proliferation and gene expression by primary rat adipose-derived stem cells (ADSCs) that were cultured on a poly(dl-lactide-co-glycolide) PLAGA fiber scaffold and compared to a PLAGA 2D film scaffold. The electrospun scaffold mimics the collagen fiber bundles present in native tendon tissue, and supports the adhesion and proliferation of multipotent ADSCs. Gene expression of scleraxis, the neotendon marker, was upregulated seven- to eightfold at 1 week with GDF-5 treatment when cultured on a 3D electrospun scaffold, and was significantly higher at 2 weeks compared to 2D films with or without GDF-5 treatment. Expression of the genes that encode the major tendon ECM protein, collagen type I, was increased by fourfold starting at 1 week on treatment with 100 ng mL{sup -1} GDF-5, and at all time points the expression was significantly higher compared to 2D films irrespective of GDF-5 treatment. Thus stimulation with GDF-5 can modulate primary ADSCs on a PLAGA fiber scaffold to produce a soft, collagenous musculoskeletal tissue that fulfills the need for tendon regeneration.

  10. Human umbilical cord matrix-derived stem cells expressing interferon-β gene inhibit breast cancer cells via apoptosis

    Science.gov (United States)

    Shen, Ching-Ju; Chan, Te-Fu; Chen, Chien-Chung; Hsu, Yi-Chiang; Long, Cheng-Yu; Lai, Chung-Sheng

    2016-01-01

    Human umbilical cord mesenchymal stem cells (hUCMSCs) derived from the umbilical cord matrix have been reported to be used as anti-tumor gene carrier for attenuation of tumor growth, which extends the half-life and lowers the unexpected cytotoxicity of the gene in vivo. Interferon-β (IFNβ) is known to possess robust antitumor effects on different types of cancer cell lines in vitro. The present study was aimed to investigate the anti-tumor effect of IFNβ gene-transfected hUCMSCs (IFNβ-hUCMSCs) on breast cancer cells with emphasis on triple negative breast carcinoma. Our findings revealed that the co-culture of IFNβ-hUCMSCs with the human triple negative breast carcinoma cell lines MDA-MB-231 or Hs578T significantly inhibited growth of both carcinoma cells. In addition, the culture medium conditioned by these cells also significantly suppressed the growth and induced apoptosis of both carcinoma cells. Further investigation showed that the suppressed growth and the apoptosis induced by co-culture of IFNβ-hUCMSCs or conditioned medium were abolished by pretreating anti-IFNβ neutralizing antibody. These findings indicate that IFNβ-hUCMSCs triggered cell death of breast carcinoma cells through IFN-β production, thereby induced apoptosis and suppressed tumor cell growth. In conclusion, we demonstrated that IFNβ-hUCMSCs inhibited the growth of breast cancer cells through apoptosis. with potent anti-cancer activity, it represents as an anti-cancer cytotherapeutic modality against breast cancer. PMID:27129156

  11. Fuzzy Entropy Relevance Analysis in DWT and EMD for BCI Motor Imagery ApplicationsAnálisis de Relevancia con Entropía Difusa en Aplicaciones BCI con Imaginación Motora mediante Descomposiciones DWT y EMD

    Directory of Open Access Journals (Sweden)

    Boris Medina Salgado

    2015-02-01

    Full Text Available Rhythm analysis in advanced signal processing methods has long of interest in application areas such as diagnosis of brain disorders, epilepsy, sleep or anesthesia analysis, and more recently in brain computer interfaces. In this paper the Discrete Wavelet Transform (DWT and Empirical Mode Decomposition (EMD techniques are applied to extract the brain rhythms from electroencephalographic (EEG signals in motor imagination tasks, of left-and right hand, using public dataset BCI Competition 2003. Then the brain rhythms are characterized by statistical features. Additionally, fuzzy entropy algorithm was used to perform the relevance analysis to determine the most important features in the training set. Classification stage was performed using K-NN classifiers and SVM, obtaining classification accuracy up to 100% with EMD. Classification results allow us to infer that the techniques used are appropriate to generate solutions in BCI applications for recognizing motor imagination in people with motor disabilities.

  12. Epithelial expression of extracellular matrix metalloproteinase inducer/CD147 and matrix metalloproteinase-2 in neoplasms and precursor lesions derived from cutaneous squamous cells: An immunohistochemical study.

    Science.gov (United States)

    Ayva, Sebnem Kupana; Karabulut, Ayse Anil; Akatli, Ayşe Nur; Atasoy, Pinar; Bozdogan, Onder

    2013-10-01

    Extracellular matrix metalloproteinase inducer (CD147) is a transmembrane glycoprotein involved in the regulation of matrix metalloproteinases (MMPs). The study investigated CD147 and MMP-2 expression in epidermis of cutaneous squamous lesions. CD147 and MMP-2 expressions were evaluated immunohistochemically in 44 specimens: 18 actinic keratoses (AK), 6 squamous cell carcinomas in situ (SCCIS), 13 squamous cell carcinomas (SCC; peritumoral and invasive portions assessed), and 7 normal skins. Patterns of expression were assessed, with MMP-2 in nuclei (MMP-2n) and cytoplasm (MMP-2c) evaluated separately. The expression of each marker was quantified using a calculated immunohistochemical/histologic score (H-score). Correlations were analyzed for the marker H-scores in each study group. Associations between H-scores and histopathologic parameters were also evaluated. CD147 H-score was the highest in SCC (invasive islands), followed by AK, SCCIS, and control specimens, respectively. MMP-2n and MMP-2c H-scores were the highest in AK, followed by SCCIS, SCC, and control specimens, respectively. MMP-2c and MMP-2n H-scores were significantly higher in peritumoral epidermis than in invasive islands of SCC. MMP-2c and CD147 H-scores were positively correlated in the peritumoral SCCs. CD147 H-score was positively correlated with tumor differentiation in SCC. The findings suggest that overexpression of CD147 plays a role in the development of SCC.

  13. EMD-ISMO算法在电力负荷预测中的应用

    Institute of Scientific and Technical Information of China (English)

    翟永杰; 周倩; 韩璞

    2010-01-01

    电力负荷是受多种因素影响的复杂非线性系统,具有明显的周期波动性和趋势性。利用集平稳化和层次化处理能力于一体的经验模态分解(EMD)方法处理非线性非平稳信号的有效性,对电力负荷数据进行平稳化处理,分离出12组IMF数据,包含若干个不同频率的平稳分量,能更明显地看出原负荷序列的周期项、随机项和趋势项;结合对负荷数据具有很好预测能力的改进SMO算法(ISMO),对IMF数据进行分别预测和组合预测,提出了一种EMD-ISMO算法。实验结果表明,该方法无论在预测精度还是收敛速度上都比单纯的SMO算法有了很大改进,取得了很好的预测效果。

  14. EMD self-adaptive selecting relevant modes algorithm for FBG spectrum signal

    Science.gov (United States)

    Chen, Yong; Wu, Chun-ting; Liu, Huan-lin

    2017-07-01

    Noise may reduce the demodulation accuracy of fiber Bragg grating (FBG) sensing signal so as to affect the quality of sensing detection. Thus, the recovery of a signal from observed noisy data is necessary. In this paper, a precise self-adaptive algorithm of selecting relevant modes is proposed to remove the noise of signal. Empirical mode decomposition (EMD) is first used to decompose a signal into a set of modes. The pseudo modes cancellation is introduced to identify and eliminate false modes, and then the Mutual Information (MI) of partial modes is calculated. MI is used to estimate the critical point of high and low frequency components. Simulation results show that the proposed algorithm estimates the critical point more accurately than the traditional algorithms for FBG spectral signal. While, compared to the similar algorithms, the signal noise ratio of the signal can be improved more than 10 dB after processing by the proposed algorithm, and correlation coefficient can be increased by 0.5, so it demonstrates better de-noising effect.

  15. Muscle-derived Decellularised Extracellular Matrix Improves Functional Recovery in a Rat Latissimus Dorsi Muscle Defect Model

    Science.gov (United States)

    2013-12-01

    Piccolo R, et al. Experimental abdominal wall defect repaired with acellular matrix. Pediatr Surg Int 2002;18:327e31. 28. Willett NJ, Li MT, Uhrig BA...matrix (M-ECM). Methods: Ten percent of the mass of the latissimus dorsi (LD) was excised. Three groups were examined: 1) no repair of defect (DEF), 2...to develop therapies for ex- tremity10,11 or abdominal muscle repair.16 For the devel- opment of potential therapies for craniofacial muscle repair

  16. Pulse shape analysis of a two fold clover detector with an EMD based new algorithm: A comparison

    Energy Technology Data Exchange (ETDEWEB)

    Siwal, Davinder, E-mail: dev84sonu@gmail.com [Department of Physics and Astrophysics, University of Delhi, Delhi 110007 (India); Mandal, S. [Department of Physics and Astrophysics, University of Delhi, Delhi 110007 (India); Palit, R.; Sethi, J. [Department of Nuclear and Atomic Physics, Tata Institute of Fundamental Research, Mumbai 400005 (India); Garg, R. [Department of Physics and Astrophysics, University of Delhi, Delhi 110007 (India); Saha, S. [Department of Nuclear and Atomic Physics, Tata Institute of Fundamental Research, Mumbai 400005 (India); Prasad, Awadhesh [Department of Physics and Astrophysics, University of Delhi, Delhi 110007 (India); Chavan, P.B.; Naidu, B.S.; Jadhav, S.; Donthi, R. [Department of Nuclear and Atomic Physics, Tata Institute of Fundamental Research, Mumbai 400005 (India); Schaffner, H.; Adamczewski-Musch, J.; Kurz, N.; Wollersheim, H.J. [GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt (Germany); Singh, R. [Amity Institute of Nuclear Science and Technology, Amity University, Noida 201303 (India)

    2014-03-21

    An investigation of Empirical Mode Decomposition (EMD) based noise filtering algorithm has been carried out on a mirror signal from a two fold germanium clover detector. EMD technique can decompose linear as well as nonlinear and chaotic signals with a precise frequency resolution. It allows to decompose the preamplifier signal (charge pulse) on an event-by-event basis. The filtering algorithm provides the information about the Intrinsic Mode Functions (IMFs) mainly dominated by the noise. It preserves the signal information and separates the overriding noise oscillations from the signals. The identification of noise structure is based on the frequency distributions of different IMFs. The preamplifier noise components which distort the azimuthal co-ordinates information have been extracted on the basis of the correlation between the different IMFs and the mirror signal. The correlation studies have been carried out both in frequency and time domain. The extracted correlation coefficient provides an important information regarding the pulse shape of the γ-ray interaction in the detector. A comparison between the EMD based and state-of-the-art wavelet based denoising techniques has also been made and discussed. It has been observed that the fractional noise strength distribution varies with the position of the collimated gamma-ray source. Above trend has been reproduced by both the denoising techniques.

  17. Clinical and Radiographic Evaluation of the Effectiveness of Formocresol, Mineral Trioxide Aggregate, Portland Cement, and Enamel Matrix Derivative in Primary Teeth Pulpotomies: A Two Year Follow-Up.

    Science.gov (United States)

    Yildirim, Ceren; Basak, Feridun; Akgun, Ozlem Marti; Polat, Gunseli Guven; Altun, Ceyhan

    2016-01-01

    The aim of this study was to evaluate and to compare clinical and radiographic outcomes of 4 materials (formocresol, mineral trioxide aggregate (MTA), Portland cement and enamel matrix derivative) using in primary teeth pulpotomies. Sixty-five patients aged 5-9 years (32 female, 33 male) were included in this study. A total of 140 primary first and second molars with deep caries were treated with pulpotomy. All teeth were then restored with stainless steel crowns. The treated teeth were evaluated clinically and radiographically at 3, 6, 12, 18 and 24 months. At 24 months, the clinical success rates of formocresol, MTA, Portland cement, and enamel matrix derivative were 96.9%, 100%, 93.9%, and 93.3%, respectively. The corresponding radiographic success rates were 84.4%, 93.9%, 86.7% and 78.1%, respectively. Although there were no statistically significant differences in clinical and radiographic success rates among the 4 groups, MTA appears to be superior to formocresol, Portland cement, and enamel matrix derivative as a pulpotomy agent in primary teeth.

  18. A hybrid AR-EMD-SVR model for the short-term prediction of nonlinear and non-stationary ship motion

    Institute of Scientific and Technical Information of China (English)

    Wen-yang DUAN; Li-min HUANG; Yang HAN; Ya-hui ZHANG; Shuo HUANG

    2015-01-01

    题目:用于非线性非平稳船舶运动极短期预报的一种复合自回归经验模态分解支持向量机回归模型  目的:基于支持向量机回归(SVR)模型在非线时间序列的预测能力及经验模态分解(EMD)方法在处理非线性非平稳性的优势,提出一种复合自回归经验模态分解支持向量机回归(AR-EMD-SVR)模型,提高非线性非平稳船舶运动极短期预报精度。  创新点:1.研究非线性非平稳船舶运动的极短期预报问题,提出一种复合的预报方法;2.基于不同层次的预报模型和模型试验数据,分析非线性非平稳性对极短期预报精度的影响。  方法:1.在SVR模型中引入基于自回归(AR)预报端点延拓的 EMD 方法,形成复合的 AR-EMD-SVR 预报模型;2.基于集装箱船模水池试验运动数据将 AR-EMD-SVR 模型与 AR、SVR 和EMD-AR 三种模型进行比较,分析非线性非平稳性对极短期预报的影响以及不同模型的预报性能。  结论:1. AR-EMD 方法能够有效的克服非平稳对极短期预报模型(AR和 SVR)在精度上所带来的不良影响;2.基于船模试验数据的预报结果表明:相较于 AR、SVR 和 EMD-AR 三种预报模型,基于 AR-EMD-SVR模型的非线性非平稳船舶运动极短期预报结果具有更高的精度。%Accurate and reliable short-term prediction of ship motions offers improvements in both safety and control quality in ship motion sensitive maritime operations. Inspired by the satisfactory nonlinear learning capability of a support vector re-gression (SVR) model and the strong non-stationary processing ability of empirical mode decomposition (EMD), this paper develops a hybrid autoregressive (AR)-EMD-SVR model for the short-term forecast of nonlinear and non-stationary ship motion. The proposed hybrid model is designed by coupling the SVR model with an AR-EMD technique, which employs an AR model in ends

  19. Removal of BCG artefact from concurrent fMRI-EEG recordings based on EMD and PCA.

    Science.gov (United States)

    Javed, Ehtasham; Faye, Ibrahima; Malik, Aamir Saeed; Abdullah, Jafri Malin

    2017-08-24

    Simultaneous electroencephalography (EEG) and functional magnetic resonance image (fMRI) acquisitions provide better insight into brain dynamics. Some artefacts due to simultaneous acquisition pose a threat to the quality of the data. One such problematic artefact is the ballistocardiogram (BCG) artefact. We developed a hybrid algorithm that combines features of empirical mode decomposition (EMD) with principal component analysis (PCA) to reduce the BCG artefact. The algorithm does not require extra electrocardiogram (ECG) or electrooculogram (EOG) recordings to extract the BCG artefact. The method was tested with both simulated and real EEG data of 11 participants. From the simulated data, the similarity index between the extracted BCG and the simulated BCG showed the effectiveness of the proposed method in BCG removal. On the other hand, real data were recorded with two conditions, i.e. resting state (eyes closed dataset) and task influenced (event-related potentials (ERPs) dataset). Using qualitative (visual inspection) and quantitative (similarity index, improved normalized power spectrum (INPS) ratio, power spectrum, sample entropy (SE)) evaluation parameters, the assessment results showed that the proposed method can efficiently reduce the BCG artefact while preserving the neuronal signals. Compared with conventional methods, namely, average artefact subtraction (AAS), optimal basis set (OBS) and combined independent component analysis and principal component analysis (ICA-PCA), the statistical analyses of the results showed that the proposed method has better performance, and the differences were significant for all quantitative parameters except for the power and sample entropy. The proposed method does not require any reference signal, prior information or assumption to extract the BCG artefact. It will be very useful in circumstances where the reference signal is not available. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Schwinger-Dyson operator of Yang-Mills matrix models with ghosts and derivations of the graded shuffle algebra

    NARCIS (Netherlands)

    Krishnaswami, G.S.

    2008-01-01

    We consider large-N multi-matrix models whose action closely mimics that of Yang-Mills theory, including gauge-fixing and ghost terms. We show that the factorized Schwinger-Dyson loop equations, expressed in terms of the generating series of gluon and ghost correlations G( ), are quadratic equations

  1. Repair of Traumatic Skeletal Muscle Injury with Bone-Marrow-Derived Mesenchymal Stem Cells Seeded on Extracellular Matrix

    Science.gov (United States)

    2010-06-02

    Hammers D. W., Le L. N., Gokhale R., Sarathy A., Song T. J., Tierney M. T., Suggs L. J., Walters T. J., Farrar R. P., 5d. PROJECT NUMBER 5e. TASK...vivo. Bioma terials 30, 2393, 2009. 65. Beattie, A.J., et al. Chemoattraction of Progenitor Cells by Remodeling Extracellular Matrix Scaffolds

  2. Cardiac fibroblast-derived extracellular matrix (biomatrix) as a model for the studies of cardiac primitive cell biological properties in normal and pathological adult human heart.

    Science.gov (United States)

    Castaldo, Clotilde; Di Meglio, Franca; Miraglia, Rita; Sacco, Anna Maria; Romano, Veronica; Bancone, Ciro; Della Corte, Alessandro; Montagnani, Stefania; Nurzynska, Daria

    2013-01-01

    Cardiac tissue regeneration is guided by stem cells and their microenvironment. It has been recently described that both cardiac stem/primitive cells and extracellular matrix (ECM) change in pathological conditions. This study describes the method for the production of ECM typical of adult human heart in the normal and pathological conditions (ischemic heart disease) and highlights the potential use of cardiac fibroblast-derived ECM for in vitro studies of the interactions between ECM components and cardiac primitive cells responsible for tissue regeneration. Fibroblasts isolated from adult human normal and pathological heart with ischemic cardiomyopathy were cultured to obtain extracellular matrix (biomatrix), composed of typical extracellular matrix proteins, such as collagen and fibronectin, and matricellular proteins, laminin, and tenascin. After decellularization, this substrate was used to assess biological properties of cardiac primitive cells: proliferation and migration were stimulated by biomatrix from normal heart, while both types of biomatrix protected cardiac primitive cells from apoptosis. Our model can be used for studies of cell-matrix interactions and help to determine the biochemical cues that regulate cardiac primitive cell biological properties and guide cardiac tissue regeneration.

  3. Slow-release of methanogenic inhibitors derived from encapsulated calcium carbide using paraffin wax and/or rosin: matrix optimization and diffusion characteristics.

    Science.gov (United States)

    Tiantao, Zhao; Youcai, Zhao; Lijie, Zhang; Haoquan, Chen; Feng, Shi; Haiyan, Zhou

    2011-11-01

    Acetylene has been found to significantly inhibit biological activity of methanogens and thus might be applicable for reducing the generation and emission of methane from municipal solid waste landfills. However, acetylene is gaseous and so it is considered physically infeasible to directly apply this gas to waste in landfill conditions. In the present study, a novel acetylene release mechanism was tested, using a matrix of acetylene entrapped in high hydrophobic paraffin wax and/or rosin and calcium carbide capsules with a ratio of 1.0 g g(-1) matrix and a diameter of 10 mm to facilitate the gradual release of acetylene. A diffusion mechanism model (Q = &b.gamma; × t (0.5)) for the matrix was derived based on the T. Higuchi equation, and the effective diffusion coefficients (D(e)) were acquired by linear fitting. Additionally, it was found that D(e) remained constant when the rosin content was up to more than 20% g g(-1) matrix.

  4. Cardiac Fibroblast-Derived Extracellular Matrix (Biomatrix as a Model for the Studies of Cardiac Primitive Cell Biological Properties in Normal and Pathological Adult Human Heart

    Directory of Open Access Journals (Sweden)

    Clotilde Castaldo

    2013-01-01

    Full Text Available Cardiac tissue regeneration is guided by stem cells and their microenvironment. It has been recently described that both cardiac stem/primitive cells and extracellular matrix (ECM change in pathological conditions. This study describes the method for the production of ECM typical of adult human heart in the normal and pathological conditions (ischemic heart disease and highlights the potential use of cardiac fibroblast-derived ECM for in vitro studies of the interactions between ECM components and cardiac primitive cells responsible for tissue regeneration. Fibroblasts isolated from adult human normal and pathological heart with ischemic cardiomyopathy were cultured to obtain extracellular matrix (biomatrix, composed of typical extracellular matrix proteins, such as collagen and fibronectin, and matricellular proteins, laminin, and tenascin. After decellularization, this substrate was used to assess biological properties of cardiac primitive cells: proliferation and migration were stimulated by biomatrix from normal heart, while both types of biomatrix protected cardiac primitive cells from apoptosis. Our model can be used for studies of cell-matrix interactions and help to determine the biochemical cues that regulate cardiac primitive cell biological properties and guide cardiac tissue regeneration.

  5. Prophylactic and therapeutic effects of acute systemic injections of EMD 281014, a selective serotonin 2A receptor antagonist on anxiety induced by predator stress in rats.

    Science.gov (United States)

    Adamec, Robert; Creamer, Katherine; Bartoszyk, Gerd D; Burton, Paul

    2004-11-03

    We examined the effect of the selective serotonin 2A (5-HT(2A)) receptor antagonist 7-[4-[2-(4-fluoro-phenyl)-ethyl]-piperazine-1-carbonyl]-1H-indole-3-carbon itrile HCl (EMD 281014) [Bartoszyk, G.D., van Amsterdam, C., Bottcher, H., Seyfried, C.A., 2003. EMD 281014, a new selective serotonin 5-HT2A receptor antagonist. Eur. J. Pharmacol. 473, 229-230.] on change in affect following predator stress. Predator stress involved a 5 min unprotected exposure of rats to a domestic cat. Behavioral effects of stress were evaluated with hole board, plus maze, light/dark box and acoustic startle tests 1 week after stress. Predator stress increased anxiety-like behavior in the plus maze, light/dark box, and elevated response to acoustic startle. EMD 281014 (0.001, 0.01, 0.1, 1 or 10 mg/kg) and vehicle injection (ip) occurred either 10 min after predator stress (prophylactic testing), or 90 min prior to behavioral testing for the effects of predator stress (therapeutic testing 1 week after predator stress). In prophylactic testing, EMD 281014 prevented stress potentiation of startle in a dose dependent manner, though the most effective doses were midrange (0.01 and 0.1 mg/kg). Prophylactic administration of EMD 281014 also prevented stress-induced increase of open arm avoidance in the plus maze in a clear dose dependent manner (from 0.01 mg/kg onward). In therapeutic testing, EMD 281014 had no clear drug dependent effects on stress elevation of startle or on behavior of stressed rats in the elevated plus maze. Finally, EMD 281014 did not block the effects of stress on behavior in the light/dark box when given prophylactically or therapeutically. Findings implicate 5-HT(2A) receptors in initiation of some but not all lasting changes in anxiety-like behavior following predator stress. Potential clinical significance of findings are discussed.

  6. Platelet-derived growth factor type BB and collagen matrix for soft tissue reconstruction after muco-epidermoid carcinoma removal: A possible therapeutic option

    Directory of Open Access Journals (Sweden)

    Marco Cicciù

    2015-01-01

    Full Text Available Muco-epidermoid carcinoma (MEC is a rare malignant tumor occurring in major and minor salivary glands. The described case shows a patient undergoing tumor resection without neck dissection. A quick diagnosis performed through clinical investigation and incisional biopsy revealed the nature of the tumor. A porcine collagen matrix was applied after the surgery in order to improve soft tissue healing. The matrix was saturated with platelet-derived growth factor type BB in order to favorite healing process and then fixed on the palate with a dental support device. Follow-up visit performed at first, second, and third weeks highlighted a quick healing of oral mucosa. Here reported is a case of a 34-year-old man who developed a muco-epidermoid oral carcinoma localized in the left upper jaw palatal side. The clinical, radiographic, and histopathologic findings, plus differential diagnoses of the case and reconstructive treatment options are also presented.

  7. EMD-SDC方法在机载连接词语音识别系统中的应用%Application of EMD-SDC in airplane conjunction speech recognition system

    Institute of Scientific and Technical Information of China (English)

    严家明; 李永恒

    2012-01-01

    机载连接词语音识别系统与传统语音识别系统相比,具有背景噪声大,系统识别率要求高等特点.依据这些特点,提出了一种基于经验模态分解增强和位移差分倒谱特征的EMD-SDC连接词语音识别方法.经验模态分解的调频调幅特性,可以有效提高机载复杂噪声背景下的端点检测准确度,位移差分倒谱特征由语音帧的一阶差分谱连接扩展而成,能够更好地提取依赖于语言结构的时序信息.该方法对机载交通预警避撞系统提示语音库进行测试,实验结果表明,采用EMD-SDC方法的机载连接词语音识别系统,能够很好地克服机舱背景噪声干扰,在低信噪比条件下实现较高的识别率.%Compared with traditional speech recognition system, airplane conjunction speech recognition system has background noise, and requires a high recognition rate and so on. According to these features, this paper proposes a EMD-SDC method with empirical mode decomposition and shifted delta cepstral features. Empirical mode decomposition with characteristics of AM FM can substantially increase endpoint detection accuracy under complex airplane noise environment. Shifted delta cepstral which is composed of first-order differential spectral of the speech frames, can capture the time sequence information depending on the structure of the language well. This method is tested for airplane traffic collision avoidance system database, experimental result shows that the airplane conjunction speech recognition system with EMD-SDC method can overcome cabin background noise and achieve a higher recognition rate in the low SNR.

  8. Exhaustive derivation of static self-consistent multi-soliton solutions in the matrix Bogoliubov-de Gennes systems

    CERN Document Server

    Takahashi, Daisuke A

    2015-01-01

    The matrix-generalized Bogoliubov-de Gennes systems are recently considered by the present author [arXiv:1509.04242], and the time-dependent and self-consistent multi-soliton solutions are constructed based on the ansatz method. In this paper, restricting the problem to the static case, we exhaustively determine the self-consistent solutions using the inverse scattering theory. Solving the gap equation, we rigorously prove that the self-consistent potential must be reflectionless. As a supplementary topic, we elucidate the relation between the stationary self-consistent potentials and the soliton solutions in the matrix nonlinear Schr\\"odinger equation. The asymptotic formulae of multi-soliton solutions for sufficiently isolated solitons are also presented.

  9. Hypoxia Affects the Structure of Breast Cancer Cell-Derived Matrix to Support Angiogenic Responses of Endothelial Cells.

    Science.gov (United States)

    Hielscher, Abigail; Qiu, Connie; Porterfield, Josh; Smith, Quinton; Gerecht, Sharon

    2013-01-01

    Hypoxia, a common feature of the tumor environment and participant in tumor progression, is known to alter gene and protein expression of several Extracellular Matrix (ECM) proteins, many of which have roles in angiogenesis. Previously, we reported that ECM deposited from co-cultures of Neonatal Fibroblasts (NuFF) with breast cancer cells, supported 3-dimensional vascular morphogenesis. Here, we sought to characterize the hypoxic ECM and to identify whether the deposited ECM induce angiogenic responses in Endothelial Cells (ECs). NuFF and MDA-MB-231 breast cancer cells were co-cultured, subjected to alternating cycles of 24 hours of 1% (hypoxia) and 21% (atmospheric) oxygen and de-cellularized for analyses of deposited ECM. We report differences in mRNA expression profiles of matrix proteins and crosslinking enzymes relevant to angiogenesis in hypoxia-exposed co-cultures. Interestingly, overt differences in the expression of ECM proteins were not detected in the de-cellularized ECM; however, up-regulation of the cell-binding fragment of fibronecin was observed in the conditioned media of hypoxic co-cultures. Ultrastructure analyses of the de-cellularized ECM revealed differences in fiber morphology with hypoxic fibers more compact and aligned, occupying a greater percent area and having larger diameter fibers than atmospheric ECM. Examining the effect of hypoxic ECM on angiogenic responses of ECs, morphological differences in Capillary-Like Structures (CLS) formed atop de-cellularized hypoxic and atmospheric ECM were not evident. Interestingly, we found that hypoxic ECM regulated the expression of angiogenic factors and matrix metalloproteinases in CLS. Overall, we report that in vitro, hypoxia does not alter the composition of the ECM deposited by co-cultures of NuFF/MDA-MB-231, but rather alters fiber morphology, and induces vascular expression of angiogenic growth factors and metalloproteinases. Taken together, these results have important implications for

  10. Skeletal Muscle Regeneration in a Rat (Rattus norvegicus) Model with CorMatrix and Adipose Derived Stem Cells

    Science.gov (United States)

    2015-07-16

    not provide a regenerative scaffold for growth of skeletal muscle after volumetric muscle loss. 12. PROTOCOL OUTCOME SUMMARY: (Please provide, in...additional pages if necessary.) PROTOCOL #: FDG20130044A DATE: 16 July 2015 PROTOCOL TITLE: "Skeletal Muscle Regeneration in a Rat (Rattus no1Vegicus...volumetric muscle loss, with a clinical need for enhanced repair. Extracellular matrix (ECM) shows promise to regenerate skeletal muscle , opening a

  11. Impact of extracellular matrix derived from osteoarthritis subchondral bone osteoblasts on osteocytes: role of integrinβ1 and focal adhesion kinase signaling cues.

    Science.gov (United States)

    Prasadam, Indira; Farnaghi, Saba; Feng, Jian Q; Gu, Wenyi; Perry, Samuel; Crawford, Ross; Xiao, Yin

    2013-10-09

    Our recent study indicated that subchondral bone pathogenesis in osteoarthritis (OA) is associated with osteocyte morphology and phenotypic abnormalities. However, the mechanism underlying this abnormality needs to be identified. In this study we investigated the effect of extracellular matrix (ECM) produced from normal and OA bone on osteocytic cells function. De-cellularized matrices, resembling the bone provisional ECM secreted from primary human subchondral bone osteoblasts (SBOs) of normal and OA patients were used as a model to study the effect on osteocytic cells. Osteocytic cells (MLOY4 osteocyte cell line) cultured on normal and OA derived ECMs were analyzed by confocal microscopy, scanning electron microscopy (SEM), cell attachment assays, zymography, apoptosis assays, qRT-PCR and western blotting. The role of integrinβ1 and focal adhesion kinase (FAK) signaling pathways during these interactions were monitored using appropriate blocking antibodies. The ECM produced by OA SBOs contained less mineral content, showed altered organization of matrix proteins and matrix structure compared with the matrices produced by normal SBOs. Culture of osteocytic cells on these defective OA ECM resulted in a decrease of integrinβ1 expression and the de-activation of FAK cell signaling pathway, which subsequently affected the initial osteocytic cell's attachment and functions including morphological abnormalities of cytoskeletal structures, focal adhesions, increased apoptosis, altered osteocyte specific gene expression and increased Matrix metalloproteinases (MMP-2) and -9 expression. This study provides new insights in understanding how altered OA bone matrix can lead to the abnormal osteocyte phenotypic changes, which is typical in OA pathogenesis.

  12. Synoviocyte Derived-Extracellular Matrix Enhances Human Articular Chondrocyte Proliferation and Maintains Re-Differentiation Capacity at Both Low and Atmospheric Oxygen Tensions.

    Directory of Open Access Journals (Sweden)

    Thomas J Kean

    Full Text Available Current tissue engineering methods are insufficient for total joint resurfacing, and chondrocytes undergo de-differentiation when expanded on tissue culture plastic. De-differentiated chondrocytes show poor re-differentiation in culture, giving reduced glycosaminoglycan (GAG and collagen matrix accumulation. To address this, porcine synoviocyte-derived extracellular matrix and low (5% oxygen tension were assessed for their ability to enhance human articular chondrocyte expansion and maintain re-differentiation potential.Porcine synoviocyte matrices were devitalized using 3 non-detergent methods. These devitalized synoviocyte matrices were compared against tissue culture plastic for their ability to support human chondrocyte expansion. Expansion was further compared at both low (5%, and atmospheric (20% oxygen tension on all surfaces. Expanded cells then underwent chondrogenic re-differentiation in aggregate culture at both low and atmospheric oxygen tension. Aggregates were assessed for their GAG and collagen content both biochemically and histologically.Human chondrocytes expanded twice as fast on devitalized synoviocyte matrix vs. tissue culture plastic, and cells retained their re-differentiation capacity for twice the number of population doublings. There was no significant difference in growth rate between low and atmospheric oxygen tension. There was significantly less collagen type I, collagen type II, aggrecan and more MMP13 expression in cells expanded on synoviocyte matrix vs. tissue culture plastic. There were also significant effects due to oxygen tension on gene expression, wherein there was greater collagen type I, collagen type II, SOX9 and less MMP13 expression on tissue culture plastic compared to synoviocyte matrix. There was a significant increase in GAG, but not collagen, accumulation in chondrocyte aggregates re-differentiated at low oxygen tension over that achieved in atmospheric oxygen conditions.Synoviocyte-derived

  13. EMD-Based Emotion Computing for Speech Sign%语音信号中基于EMD法的情感计算

    Institute of Scientific and Technical Information of China (English)

    秦宇强; 张雪英

    2011-01-01

    情感计算是情感语音识别的关键.经验模态分解(EMD)算法是Hilbert-Huang变换(HHT)的核心算法,采用分段幂函数插值算法求情感包络线,能达到更好的情感识别效果.利用软件MATLAB仿真了情感语音信号的经验模态分解(EMD)特性,把情感语音信号进行EMD分解后IMF做频谱变换,便能得到一个情感包络线,根据情感包络线的不同而达到情感识别的目的.%Emotion computing is the key to emotional 8peech recognition. Empirical mode decomposition (EMD)is the core of Hilbert-Huang transformation. Using the piecewise power function in emotional envelope, has a better effect in emotion identification. MATLAB is used to calculate the characteristic of emotional speech signal using empirical mode decomposition (EMD), we obtain an emotional envelope by transforming the IMF of emotional speech signal,and obtain a new method of emotion recognition using EMD.

  14. Synthesis and characterization of sol–gel derived ZnS : Mn2+ nanocrystallites embedded in a silica matrix

    Indian Academy of Sciences (India)

    B Bhattacharjee; D Ganguli; K Iakoubovskii; A Stesmans; S Chaudhuri

    2002-06-01

    Synthesis and characterization of undoped and Mn2+ doped ZnS nanocrystallites (radius 2–3 nm) embedded in a partially densified silica gel matrix are presented. Optical transmittance, photoluminescence (PL), ellipsometric and electron spin resonance measurements revealed manifestation of quantum size effect. PL spectra recorded at room temperature revealed broad blue emission signal centred at ∼ 420 nm and Mn2+ related yellow–orange band centred at ∼ 590 nm while ESR indicated that Mn in ZnS was present as dispersed impurity rather than Mn cluster.

  15. Identification and Characterization of Novel Matrix-Derived Bioactive Peptides: A Role for Collagenase from Santyl® Ointment in Post-Debridement Wound Healing?

    Science.gov (United States)

    Sheets, Anthony R; Demidova-Rice, Tatiana N; Shi, Lei; Ronfard, Vincent; Grover, Komel V; Herman, Ira M

    2016-01-01

    Debridement, the removal of diseased, nonviable tissue, is critical for clinicians to readily assess wound status and prepare the wound bed for advanced therapeutics or downstream active healing. Removing necrotic slough and eschar through surgical or mechanical methods is less specific and may be painful for patients. Enzymatic debridement agents, such as Clostridial collagenase, selectively and painlessly degrade devitalized tissue. In addition to its debriding activities, highly-purified Clostridial collagenase actively promotes healing, and our past studies reveal that extracellular matrices digested with this enzyme yield peptides that activate cellular migratory, proliferative and angiogenic responses to injury in vitro, and promote wound closure in vivo. Intriguingly, while collagenase Santyl® ointment, a sterile preparation containing Clostridial collagenases and other non-specific proteases, is a well-accepted enzymatic debridement agent, its role as an active healing entity has never been established. Based on our previous studies of pure Clostridial collagenase, we now ask whether the mixture of enzymes contained within Santyl® produces matrix-derived peptides that promote cellular injury responses in vitro and stimulate wound closure in vivo. Here, we identify novel collagen fragments, along with collagen-associated peptides derived from thrombospondin-1, multimerin-1, fibronectin, TGFβ-induced protein ig-h3 and tenascin-C, generated from Santyl® collagenase-digested human dermal capillary endothelial and fibroblastic matrices, which increase cell proliferation and angiogenic remodeling in vitro by 50-100% over controls. Using an established model of impaired healing, we further demonstrate a specific dose of collagenase from Santyl® ointment, as well as the newly-identified and chemically-synthesized ECM-derived peptides significantly increase wound re-epithelialization by 60-100% over saline-treated controls. These results not only confirm and

  16. Explaining Air and Water Transport in Undisturbed Soils By X-Ray CT Derived Macroporosity and CT- Number-Derived Matrix Density

    DEFF Research Database (Denmark)

    Paradelo Pérez, Marcos; Katuwal, Sheela; Møldrup, Per

    The characterization of soil pore space geometry is important to predict the fluxes of air, water and solutes through soil and understand soil hydrogeochemical functions. X-ray computed tomography (CT) -derived parameters were evaluated as predictors of water, air and solute transport through soil....... Forty five soil columns (20-cm × 20-cm) were collected at an agricultural field in Estrup, Denmark. The soil columns were scanned in a medical CT-scanner. Subsequent to this, non-reactive tracer leaching experiments were performed in the laboratory together with measurements of air permeability (Ka...... is considered a robust indicator of preferential flow. Meanwhile, CT-derived limiting macro-porosity was the best predictor for Ka and log10Ksat. A best subsets regression analysis was performed combining macroporosity, limiting macroporosity and CTmatrix. The predictions of water and air flow improved using...

  17. The effect of the fibre orientation of electrospun scaffolds on the matrix production of rabbit annulus fibrosus-derived stem cells

    Institute of Scientific and Technical Information of China (English)

    Chen Liu; Caihong Zhu; Jun Li; Pinghui Zhou; Min Chen; Huilin Yang; Bin Li

    2015-01-01

    Annulus fibrosus (AF) tissue engineering has recently received increasing attention as a treatment for intervertebral disc (IVD) degeneration;however, such engineering remains challenging because of the remarkable complexity of AF tissue. In order to engineer a functional AF replacement, the fabrication of cell-scaffold constructs that mimic the cellular, biochemical and structural features of native AF tissue is critical. In this study, we fabricated aligned fibrous polyurethane scaffolds using an electrospinning technique and used them for culturing AF-derived stem/progenitor cells (AFSCs). Random fibrous scaffolds, also prepared via electrospinning, were used as a control. We compared the morphology, proliferation, gene expression and matrix production of AFSCs on aligned scaffolds and random scaffolds. There was no apparent difference in the attachment or proliferation of cells cultured on aligned scaffolds and random scaffolds. However, compared to cells on random scaffolds, the AFSCs on aligned scaffolds were more elongated and better aligned, and they exhibited higher gene expression and matrix production of collagen-I and aggrecan. The gene expression and protein production of collagen-II did not appear to differ between the two groups. Together, these findings indicate that aligned fibrous scaffolds may provide a favourable microenvironment for the differentiation of AFSCs into cells similar to outer AF cells, which predominantly produce collagen-I matrix.

  18. Bone marrow-derived myofibroblasts are the providers of pro-invasive matrix metalloproteinase 13 in primary tumor

    DEFF Research Database (Denmark)

    Lecomte, Julie; Masset, Anne; Blacher, Silvia

    2012-01-01

    provide evidence that one third of BM-derived GFP(+) cells infiltrating the tumor expressed the chondroitin sulfate proteoglycan NG2 (pericytic marker) or α-smooth muscle actin (α-SMA, myofibroblast marker), whereas almost 90% of Thy1(+) fibroblasts were originating from resident GFP-negative cells. MMP13......producing cells were exclusively α-SMA(+) cells and derived from GFP(+) BM cells. To investigate their impact on tumor invasion, we isolated mesenchymal stem cells (MSCs) from the BM of wild-type and MMP13-deficient mice. Wild-type MSC promoted cancer cell invasion in a spheroid assay, whereas MSCs obtained...... from MMP13-deficient mice failed to. Our data support the concept of fibroblast subset specialization with BM-derived α-SMA(+) cells being the main source of MMP13, a stromal mediator of cancer cell invasion....

  19. Bone marrow-derived myofibroblasts are the providers of pro-invasive matrix metalloproteinase 13 in primary tumor

    DEFF Research Database (Denmark)

    Lecomte, Julie; Masset, Anne; Blacher, Silvia

    2012-01-01

    producing cells were exclusively α-SMA(+) cells and derived from GFP(+) BM cells. To investigate their impact on tumor invasion, we isolated mesenchymal stem cells (MSCs) from the BM of wild-type and MMP13-deficient mice. Wild-type MSC promoted cancer cell invasion in a spheroid assay, whereas MSCs obtained...... from MMP13-deficient mice failed to. Our data support the concept of fibroblast subset specialization with BM-derived α-SMA(+) cells being the main source of MMP13, a stromal mediator of cancer cell invasion....

  20. COMPUTATION OF EIGENPAIRS AND THEIR DERIVATIVES OF LARGE-SCALE MATRIX BASED ON LANCZOS METHOD%基于Lanczos方法的大型矩阵特征对及其导数的计算

    Institute of Scientific and Technical Information of China (English)

    胡亚萍; 解惠青

    2012-01-01

    A new method is presented for synchro calculation of eigenpairs and their derivatives of large-scale eigenvalue problems based on Lanczos method. The convergence theory of the proposed method is established. Eigenpairs and their derivatives are computed simultaneously. The systems of equations that are solved for eigenvector derivatives can be greatly reduced from the original matrix size, thus the efficiency of computing eigenvector derivatives is improved. Numerical results show the efficiency.

  1. Noise Reduction of Steel Cord Conveyor Belt Defect Electromagnetic Signal by Combined Use of Improved Wavelet and EMD

    Directory of Open Access Journals (Sweden)

    Hong-Wei Ma

    2016-09-01

    Full Text Available In order to reduce the noise of a defect electromagnetic signal of the steel cord conveyor belt used in coal mines, a new signal noise reduction method by combined use of the improved threshold wavelet and Empirical Mode Decomposition (EMD is proposed. Firstly, the denoising method based on the improved threshold wavelet is applied to reduce the noise of a defect electromagnetic signal obtained by an electromagnetic testing system. Then, the EMD is used to decompose the denoised signal and then the effective Intrinsic Mode Function (IMF is extracted by the dominant eigenvalue strategy. Finally, the signal reconstruction is carried out by utilizing the obtained IMF. In order to verify the proposed noise reduction method, the experiments are carried out in two cases including the defective joint and steel wire rope break. The experimental results show that the proposed method in this paper obtains the higher Signal to Noise Ratio (SNR for the defect electromagnetic signal noise reduction of steel cord conveyor belts.

  2. Reversal of TGF-β1 stimulation of α-smooth muscle actin and extracellular matrix components by cyclic AMP in Dupuytren's - derived fibroblasts

    Directory of Open Access Journals (Sweden)

    Johnson Sandra

    2011-05-01

    Full Text Available Abstract Background Myofibroblasts, a derived subset of fibroblasts especially important in scar formation and wound contraction, have been found at elevated levels in affected Dupuytren's tissues. Transformation of fibroblasts to myofibroblasts is characterized by expression of alpha- smooth muscle actin (α-SMA and increased production of extracellular matrix (ECM components, both events of relevance to connective tissue remodeling. We propose that increasing the activation of the cyclic AMP (cAMP/protein kinase A signaling pathway will inhibit transforming growth factor-beta1 (TGF-β1-induced ECM synthesis and myofibroblast formation and may provide a means to blunt fibrosis. Methods Fibroblasts derived from areas of Dupuytren's contracture cord (DC, from adjacent and phenotypically normal palmar fascia (PF, and from palmar fascia from patients undergoing carpal tunnel release (CTR; CT were treated with TGF-β1 (2 ng/ml and/or forskolin (10 μM (a known stimulator of cAMP. Total RNA and protein extracted was subjected to real time RT-PCR and Western blot analysis. Results The basal mRNA expression levels of fibronectin- extra domain A (FN1-EDA, type I (COL1A2 and type III collagen (COL3A1, and connective tissue growth factor (CTGF were all significantly increased in DC- and in PF-derived cells compared to CT-derived fibroblasts. The TGF-β1 stimulation of α-SMA, CTGF, COL1A2 and COL3A1 was greatly inhibited by concomitant treatment with forskolin, especially in DC-derived cells. In contrast, TGF-β1 stimulation of FN1-EDA showed similar levels of reduction with the addition of forskolin in all three cell types. Conclusion In sum, increasing cAMP levels show potential to inhibit the formation of myofibroblasts and accumulation of ECM components. Molecular agents that increase cAMP may therefore prove useful in mitigating DC progression or recurrence.

  3. Fat-Derived Stromal Vascular Fraction Cells Enhance the Bone-Forming Capacity of Devitalized Engineered Hypertrophic Cartilage Matrix.

    Science.gov (United States)

    Todorov, Atanas; Kreutz, Matthias; Haumer, Alexander; Scotti, Celeste; Barbero, Andrea; Bourgine, Paul E; Scherberich, Arnaud; Jaquiery, Claude; Martin, Ivan

    2016-12-01

    : Engineered and devitalized hypertrophic cartilage (HC) has been proposed as bone substitute material, potentially combining the features of osteoinductivity, resistance to hypoxia, capacity to attract blood vessels, and customization potential for specific indications. However, in comparison with vital tissues, devitalized HC grafts have reduced efficiency of bone formation and longer remodeling times. We tested the hypothesis that freshly harvested stromal vascular fraction (SVF) cells from human adipose tissue-which include mesenchymal, endothelial, and osteoclastic progenitors-enhance devitalized HC remodeling into bone tissue. Human SVF cells isolated from abdominal lipoaspirates were characterized cytofluorimetrically. HC pellets, previously generated by human bone marrow-derived stromal cells and devitalized by freeze/thaw, were embedded in fibrin gel with or without different amounts of SVF cells and implanted either ectopically in nude mice or in 4-mm-diameter calvarial defects in nude rats. In the ectopic model, SVF cells added to devitalized HC directly contributed to endothelial, osteoblastic, and osteoclastic populations. After 12 weeks, the extent of graft vascularization and amount of bone formation increased in a cell-number-dependent fashion (up to, respectively, 2.0-fold and 2.9-fold using 12 million cells per milliliter of gel). Mineralized tissue volume correlated with the number of implanted, SVF-derived endothelial cells (CD31+ CD34+ CD146+). In the calvarial model, SVF activation of HC using 12 million cells per milliliter of gel induced efficient merging among implanted pellets and strongly enhanced (7.3-fold) de novo bone tissue formation within the defects. Our findings outline a bone augmentation strategy based on off-the-shelf devitalized allogeneic HC, intraoperatively activated with autologous SVF cells. This study validates an innovative bone substitute material based on allogeneic hypertrophic cartilage that is engineered

  4. Effect of low-temperature ethylene oxide and electron beam sterilization on the in vitro and in vivo function of reconstituted extracellular matrix-derived scaffolds.

    Science.gov (United States)

    Proffen, Benedikt L; Perrone, Gabriel S; Fleming, Braden C; Sieker, Jakob T; Kramer, Joshua; Hawes, Michael L; Murray, Martha M

    2015-10-01

    Reconstituted extracellular matrix (ECM)-derived scaffolds are commonly utilized in preclinical tissue engineering studies as delivery vehicles for cells and growth factors. Translation into clinical use requires identifying a sterilization method that effectively removes bacteria but does not harm scaffold function. To determine effectiveness of sterilization and impact on ECM scaffold integrity and function, low-temperature ethylene oxide and 15 kGy electron beam irradiation techniques were evaluated. Scaffold sterility was assessed in accordance to United States Pharmacopeia Chapter 71. Scaffold matrix degradation was determined in vitro using enzymatic resistance tests and gel electrophoresis. Scaffold mechanics including elastic modulus, yield stress and collapse modulus were tested. Lastly, 14 Yorkshire pigs underwent ACL transection and bio-enhanced ACL repair using sterilized scaffolds. Histologic response of ligament, synovium, and lymph nodes was compared at 4, 6, and 8 weeks. Ethylene oxide as well as electron beam irradiation yielded sterile scaffolds. Scaffold resistance to enzymatic digestion and protein integrity slightly decreased after electron beam irradiation while ethylene oxide altered scaffold matrix. Scaffold elastic modulus and yield stress were increased after electron beam treatment, while collapse modulus was increased after ethylene oxide treatment. No significant changes in ACL dimensions, in vivo scaffold resorption rate, or histologic response of synovium, ligament, and lymph nodes with either terminal sterilization technique were detectable. In conclusion, this study identifies two methods to terminally sterilize an ECM scaffold. In vitro scaffold properties were slightly changed without significantly influencing the biologic responses of the surrounding tissues in vivo. This is a critical step toward translating new tissue engineering strategies to clinical trials. © The Author(s) 2015.

  5. Galactosylated collagen matrix enhanced in vitro maturation of human embryonic stem cell-derived hepatocyte-like cells.

    Science.gov (United States)

    Ghodsizadeh, Arefeh; Hosseinkhani, Hossein; Piryaei, Abbas; Pournasr, Behshad; Najarasl, Mostafa; Hiraoka, Yosuke; Baharvand, Hossein

    2014-05-01

    Due to their important biomedical applications, functional human embryonic stem cell-derived hepatocyte-like cells (hESC-HLCs) are an attractive topic in the field of stem cell differentiation. Here, we have initially differentiated hESCs into functional hepatic endoderm (HE) and continued the differentiation by replating them onto galactosylated collagen (GC) and collagen matrices. The differentiation of hESC-HE cells into HLCs on GC substrate showed significant up-regulation of hepatic-specific genes such as ALB, HNF4α, CYP3A4, G6P, and ASGR1. There was more albumin secretion and urea synthesis, as well as more cytochrome p450 activity, in differentiated HLCs on GC compared to the collagen-coated substrate. These results suggested that GC substrate has the potential to be used for in vitro maturation of hESC-HLCs.

  6. Fault Diagnosis for Reciprocating Compressor Bearings based on EMD-information Entropy and SVM%基于 EMD 信息熵和支持向量机的往复压缩机轴承故障诊断

    Institute of Scientific and Technical Information of China (English)

    王金东; 代梅; 夏法锋; 赵海峰

    2014-01-01

    往复压缩机工况恶劣、结构复杂、易损件多等特点,增加了压缩机故障诊断难度。将EMD信息熵和支持向量机(SVM)技术相结合,应用于压缩机轴承故障诊断。通过EMD对压缩机轴承信号进行分解,计算其信息熵值,并提取出能反映轴承工作状态的信息熵,将其作为特征向量训练SVM网络。结果表明,EMD信息熵和支持向量机相结合的方法,可以准确识别压缩机轴承故障。%The bad work conditions ,complicated structure and more easy-wearied parts,etc.,which add to the difficulties of fault diagnosis for reciprocating compressor .A compound fault diagnosis technique based on EMD-Information Entropy and Sup-port Vector Machine (SVM)are applied to fault diagnosis of reciprocating compressor bearings .The signals of reciprocating com-pressor bearings were divided by the method of Empirical Mode Decomposition .The Information Entropy was calculated and the characteristics which represent the compressor working condition were extracted .The Information Entropy can be as a vector to train Support Vector Machine Network .The results show that the method of combining EMD-Information Entropy and Support Vec-tor Machine can accurately identify failure of compressor bearings .

  7. Development and validation of UHPLC-MS/MS method for determination of eight naturally occurring catechin derivatives in various tea samples and the role of matrix effects.

    Science.gov (United States)

    Svoboda, Pavel; Vlčková, Hana; Nováková, Lucie

    2015-10-10

    A complete analytical procedure combining optimized tea infusion preparation and validated UHPLC-MS/MS method was developed for routine quantification of eight naturally occurring catechin derivatives in various tea samples. The preparation of tea infusions was optimized in terms of temperature, time and water-to-tea ratio in green, white and black teas. The catechins were analyzed using ultra-high performance liquid chromatography coupled with triple quadrupole mass spectrometry in a run of only 4 min including equilibration of the system. The UHPLC-MS/MS method was fully validated in terms of inter/intra-day precision, accuracy, linearity (r(2)>0.9991), range (50-5000 ng/ml), LOD (1.5-7.5 ng/ml) and LOQ (5-25 ng/ml). Validation of the method included also the determination of the matrix effects that were evaluated in both flavored and unflavored green, white and black teas. Dilution of the resulting tea infusions appeared to be crucial for the matrix effects and also for subsequent catechin quantification in real tea samples in order to fit into the linear range of the UHPLC-MS/MS method. This complete procedure for catechin quantification was finally applied to real sample analysis represented by 70 commercial tea samples.

  8. Structural determination of the conjugate of human serum albumin with a mitomycin C derivative, KW-2149, by matrix-assisted laser desorption/ionization mass spectrometry.

    Science.gov (United States)

    Yasuzawa, T; Tomer, K B

    1997-01-01

    A new mitomycin C derivative, KW-2149, is known to form a covalent conjugate with human serum albumin (HSA). This conjugate exhibits 1/20 of the anticellular activity of unconjugated KW-2149. Structural studies of this conjugate were carried out using a combination of enzymatic digestion, high-performance liquid chromatography (HPLC), and matrix-assisted laser desorption/ionization (MALDI) mass spectrometry. The tryptic peptide T5 (residues 21-41) was the only peptide found to be modified by KW-2149 moieties, the [(gamma-L-glutamylamino)ethyl]thio group or the (2-aminoethyl)thio group, through a disulfide bond. Although the latter peptide lost its mitomycin C moiety in the course of tryptic digestion, these data strongly suggest that KW-2149 was bound to Cys-34, the only free cysteine on HSA.

  9. Probing the microenvironment of an oligo-(p-phenylene vinylene) derivative encapsulated in polymer-impregnated sol-gel silica matrix

    Institute of Scientific and Technical Information of China (English)

    TANG Jun; DU Chuang; YU Xiaoqiang; ZHANG Guo; WANG Ce

    2004-01-01

    Polymer-impregnated silica sol-gel composite materials are hosts for organics in advanced optics application. An oligo-phenylene vinylene derivative 4,4'-(1,4-phenylene dithenylene)-bis-(N-methyl pyridinium iodide)(OPVD) was introduced to poly(hydroxyethyl methacrylate)(PHEMA)-impregnated silica composite film by the sol-gel process. By comparing the X-ray diffraction, UV-visible spectra, steady-state and time-resolved fluorescence spectra of OPVD in three solid matrices (PHEMA/silica composite film, pure PHEMA film, and pure silica film), the similar results of PHEMA/silica composite film and pure PHEMA film demonstrate that the OPVD is primarily surrounded by a PHEMA-like environment in the composite matrix. The model of such structure is presented, which is useful for further understanding and optimizing of properties of doped sol-gel materials.

  10. Integration of Stem Cell to Chondrocyte-Derived Cartilage Matrix in Healthy and Osteoarthritic States in the Presence of Hydroxyapatite Nanoparticles.

    Directory of Open Access Journals (Sweden)

    Rupak Dua

    Full Text Available We investigated the effectiveness of integrating tissue engineered cartilage derived from human bone marrow derived stem cells (HBMSCs to healthy as well as osteoarthritic cartilage mimics using hydroxyapatite (HA nanoparticles immersed within a hydrogel substrate. Healthy and diseased engineered cartilage from human chondrocytes (cultured in agar gels were integrated with human bone marrow stem cell (HBMSC-derived cartilaginous engineered matrix with and without HA, and evaluated after 28 days of growth. HBMSCs were seeded within photopolymerizable poly (ethylene glycol diacrylate (PEGDA hydrogels. In addition, we also conducted a preliminary in vivo evaluation of cartilage repair in rabbit knee chondral defects treated with subchondral bone microfracture and cell-free PEGDA with and without HA. Under in vitro conditions, the interfacial shear strength between tissue engineered cartilage derived from HBMSCs and osteoarthritic chondrocytes was significantly higher (p < 0.05 when HA nanoparticles were incorporated within the HBMSC culture system. Histological evidence confirmed a distinct spatial transition zone, rich in calcium phosphate deposits. Assessment of explanted rabbit knees by histology demonstrated that cellularity within the repair tissues that had filled the defects were of significantly higher number (p < 0.05 when HA was used. HA nanoparticles play an important role in treating chondral defects when osteoarthritis is a co-morbidity. We speculate that the calcified layer formation at the interface in the osteoarthritic environment in the presence of HA is likely to have attributed to higher interfacial strength found in vitro. From an in vivo standpoint, the presence of HA promoted cellularity in the tissues that subsequently filled the chondral defects. This higher presence of cells can be considered important in the context of accelerating long-term cartilage remodeling. We conclude that HA nanoparticles play an important role in

  11. Chondroinduction from Naturally Derived Cartilage Matrix: A Comparison Between Devitalized and Decellularized Cartilage Encapsulated in Hydrogel Pastes.

    Science.gov (United States)

    Beck, Emily C; Barragan, Marilyn; Libeer, Tony B; Kieweg, Sarah L; Converse, Gabriel L; Hopkins, Richard A; Berkland, Cory J; Detamore, Michael S

    2016-04-01

    Hydrogel precursors are liquid solutions that are prone to leaking after surgical placement. This problem was overcome by incorporating either decellularized cartilage (DCC) or devitalized cartilage (DVC) microparticles into traditional photocrosslinkable hydrogel precursors in an effort to achieve a paste-like hydrogel precursor. DCC and DVC were selected specifically for their potential to induce chondrogenesis of stem cells, given that materials that are chondroinductive on their own without growth factors are a revolutionary goal in orthopedic medicine. We hypothesized that DVC, lacking the additional chemical processing steps in DCC to remove cell content, would lead to a more chondroinductive hydrogel with rat bone marrow-derived mesenchymal stem cells. Hydrogels composed of methacrylated hyaluronic acid (MeHA) and either DCC or DVC microparticles were tested with and without exposure to transforming growth factor (TGF)-β3 over a 6 week culture period, where swelling, mechanical analysis, and gene expression were observed. For collagen II, Sox-9, and aggrecan expression, MeHA precursors containing DVC consistently outperformed the DCC-containing groups, even when the DCC groups were exposed to TGF-β3. DVC consistently outperformed all TGF-β3-exposed groups in aggrecan and collagen II gene expression as well. In addition, when the same concentrations of MeHA with DCC or DVC microparticles were evaluated for yield stress, the yield stress with the DVC microparticles was 2.7 times greater. Furthermore, the only MeHA-containing group that exhibited shape retention was the group containing DVC microparticles. DVC appeared to be superior to DCC in both chondroinductivity and rheological performance of hydrogel precursors, and therefore DVC microparticles may hold translational potential for cartilage regeneration.

  12. The effects of the 5-HT(6) receptor agonist EMD and the 5-HT(7) receptor agonist AS19 on memory formation.

    Science.gov (United States)

    Meneses, A; Perez-Garcia, G; Liy-Salmeron, G; Flores-Galvez, D; Castillo, C; Castillo, E

    2008-12-16

    Growing evidence indicates that 5-hydrohytryptamine (5-HT) receptors mediate learning and memory. Particularly interesting are 5-HT(6) and 5-HT(7) receptors, which are localized in brain areas involved in memory formation. Interestingly, recently selective 5-HT(6) and 5-HT(7) receptor agonists and antagonists have become available. Previous evidence indicates that 5-HT(6) or 5-HT(7) receptors antagonists had no effects, improved memory formation and/or reversed amnesia. Herein, the effects of EMD (a 5-HT(6) receptor agonist) and AS19 (a 5-HT(7) receptor agonist) in the associative learning task of autoshaping were studied. Post-training systemic administration of EMD (1-10 mg/kg) or AS19 (1-10 mg/kg) were tested in short-term memory (STM) and long-term memory (LTM). Results showed that only EMD 5.0mg/kg impaired both STM and LTM. AS19 at 1-10 mg/kg significantly impaired STM but not LTM. In those groups used to test only LTM, EMD impaired it; while AS19 improved LTM. Moreover, in the interaction experiments, the STM EMD-impairment effect was partially reversed by the selective 5-HT(6) receptor antagonist SB-399885 (10 mg/kg). The STM AS19-impairment effect (5.0 mg/kg) was not altered by the selective 5-HT(1A) antagonist WAY 100635 (0.3 mg/kg) but reversed by the selective 5-HT(7) receptor antagonist SB-269970 (10.0 mg/kg). The AS19-SB-269970 combination impaired LTM. Taken together these data suggest that the stimulation of 5-HT(6) impaired both STM and LTM. 5-HT(7) receptors stimulation impaired STM but improved LTM. And these results are discussed in the context of their possible neural bases.

  13. The combined effects of matrix stiffness and growth factor immobilization on the bioactivity and differentiation capabilities of adipose-derived stem cells.

    Science.gov (United States)

    Banks, Jessica M; Mozdzen, Laura C; Harley, Brendan A C; Bailey, Ryan C

    2014-10-01

    Biomaterial designs are increasingly incorporating multiple instructive signals to induce a desired cell response. However, many approaches do not allow orthogonal manipulation of immobilized growth factor signals and matrix stiffness. Further, few methods support patterning of biomolecular signals across a biomaterial in a spatially-selective manner. Here, we report a sequential approach employing carbodiimide crosslinking and benzophenone photoimmobilization chemistries to orthogonally modify the stiffness and immobilized growth factor content of a model collagen-GAG (CG) biomaterial. We subsequently examined the singular and combined effects of bone morphogenetic protein (BMP-2), platelet derived growth factor (PDGF-BB), and CG membrane stiffness on the bioactivity and osteogenic/adipogenic lineage-specific gene expression of adipose derived stem cells, an increasingly popular cell source for regenerative medicine studies. We found that the stiffest substrates direct osteogenic lineage commitment of ASCs regardless of the presence or absence of growth factors, while softer substrates require biochemical cues to direct cell fate. We subsequently describe the use of this approach to create overlapping patterns of growth factors across a single substrate. These results highlight the need for versatile approaches to selectively manipulate the biomaterial microenvironment to identify synergies between biochemical and mechanical cues for a range of regenerative medicine applications.

  14. Cuttlebone-derived organic matrix as a scaffold for assembly of silver nanoparticles and application of the composite films in surface-enhanced Raman scattering.

    Science.gov (United States)

    Jia, Xueping; Qian, Weiping; Wu, Dajian; Wei, Dongwei; Xu, Guilan; Liu, Xiaojun

    2009-02-01

    Biologically derived materials provide a rich variety of approaches toward new functional materials because of their fascinating structures and environment-friendly features, which is currently a topic of research interest. In this paper, we show that the cuttlebone-derived organic matrix (CDOM) is an excellent scaffold for the one-step synthesis and assembly of silver nanoparticles (AgNPs), which can be further used as substrate for surface-enhanced Raman scattering (SERS). Formation of AgNPs-CDOM composite was accomplished by the reaction of CDOM with AgNO(3) and NH(3).H(2)O solution at 80 degrees C without using any other stabilizer and reducing agents. UV-vis spectra and TEM were utilized to characterize the AgNPs and investigate their formation process. Results demonstrate that the size and distribution of AgNPs can be partly regulated by changing incubation time; the concentration of NH(3).H(2)O is critical to the formation rate of AgNPs. As a proof of principle, we show that the AgNPs-CDOM composite can be employed in trace analysis using SERS.

  15. Regulating Drug Release Behavior and Kinetics from Matrix Tablets Based on Fine Particle-Sized Ethyl Cellulose Ether Derivatives: An In Vitro and In Vivo Evaluation

    Directory of Open Access Journals (Sweden)

    Kifayat Ullah Shah

    2012-01-01

    Full Text Available The design and fabrication of sustained/controlled release dosage forms, employing new excipients capable of extending/controlling the release of drugs from the dosage forms over prolonged periods, has worked well in achieving optimally enhanced therapeutic levels of the drugs. In this sense, the objective of this study was to investigate the suitability of selected cellulose ether derivatives for use in direct compression (DC and as efficient drug release controlling agents. Controlled release matrix tablets of ciprofloxacin were prepared at different drug-to-polymer (D : P ratios by direct compression using a fine particle sized ethylcellulose ether derivative (ETHOCEL Standard Premium 7FP as rate controlling polymer. The tablets obtained were evaluated for various physico-chemical characteristics and in-vitro drug release studies were conducted in phosphate buffer (pH 7.4 using PharmaTest dissolution apparatus at constant temperature of 37∘C±0.1. Similarity factor 2 was employed to the release profiles of test formulations and were compared with marketed ciprofloxacin conventional tablets. Drug release mechanism and the kinetics involved were investigated by fitting the release profile data to various kinetic models. It was found that with increasing the proportion of ethylcellulose ether derivative in the matrix, the drug release was significantly extended up to 24 hours. The tablets exhibited zero order or nearly zero order drug transport mechanism. In vivo drug release performance of the developed controlled release tablets and reference conventional tablets containing ciprofloxacin were determined in rabbit serum according to randomized two-way crossover study design using High Performance Liquid Chromatography. Several bioavailability parameters of both the test tablets and conventional tablets including max, max and AUC0- were compared which showed an optimized max and max (<0.05. A good correlation was obtained between in vitro

  16. Regulating drug release behavior and kinetics from matrix tablets based on fine particle-sized ethyl cellulose ether derivatives: an in vitro and in vivo evaluation.

    Science.gov (United States)

    Shah, Kifayat Ullah; Khan, Gul Majid

    2012-01-01

    The design and fabrication of sustained/controlled release dosage forms, employing new excipients capable of extending/controlling the release of drugs from the dosage forms over prolonged periods, has worked well in achieving optimally enhanced therapeutic levels of the drugs. In this sense, the objective of this study was to investigate the suitability of selected cellulose ether derivatives for use in direct compression (DC) and as efficient drug release controlling agents. Controlled release matrix tablets of ciprofloxacin were prepared at different drug-to-polymer (D : P) ratios by direct compression using a fine particle sized ethylcellulose ether derivative (ETHOCEL Standard Premium 7FP) as rate controlling polymer. The tablets obtained were evaluated for various physico-chemical characteristics and in-vitro drug release studies were conducted in phosphate buffer (pH 7.4) using PharmaTest dissolution apparatus at constant temperature of 37 °C ± 0.1. Similarity factor f(2) was employed to the release profiles of test formulations and were compared with marketed ciprofloxacin conventional tablets. Drug release mechanism and the kinetics involved were investigated by fitting the release profile data to various kinetic models. It was found that with increasing the proportion of ethylcellulose ether derivative in the matrix, the drug release was significantly extended up to 24 hours. The tablets exhibited zero order or nearly zero order drug transport mechanism. In vivo drug release performance of the developed controlled release tablets and reference conventional tablets containing ciprofloxacin were determined in rabbit serum according to randomized two-way crossover study design using High Performance Liquid Chromatography. Several bioavailability parameters of both the test tablets and conventional tablets including C(max⁡), T(max⁡) and AUC(0-t) were compared which showed an optimized C(max⁡) and T(max⁡) (P < 0.05). A good correlation was obtained

  17. The effectiveness of enamel matrix protein (Emdogain® in combination with coronally advanced flap in the treatment of multiple marginal tissue recession: A clinical study

    Directory of Open Access Journals (Sweden)

    Gagan R Jaiswal

    2012-01-01

    Full Text Available Background: Gingival recession resulting in root exposure is a common problem faced by clinicians. This clinical study compared the results obtained by treating gingival recession using enamel matrix derivative (Emdogain gel® along with coronally positioned flap and coronally positioned flap alone. Materials and Methods: Twenty patients with a total of 46 gingival recession defects, each patient with a minimum of two recession defects, were included in the study. The test group, which consisted of 10 patients with 22 recession defects, was treated by enamel matrix derivatives (Emdogain gel in combination with a coronally positioned flap, while the control group, which consisted of 10 patients with 24 gingival recession defects, was treated with 24% ethylenediaminetetraacetic acid (EDTA; Prefgel® in combination with coronally positioned flap. Results: Student′s paired and unpaired t-test was used for statistical analysis. If the probability value (P was less than 0.05, it was considered significant. Data from this study demonstrated that application of (EMD Emdogain gel resulted in a statistically significant increase in root coverage, gain in the clinical attachment level (CAL, and probing pocket depth (PPD reduction when compared with coronally advanced flap (CAF alone, but there was no statistically significant difference in the width of keratinized gingiva (WKG between the two groups.

  18. Derivation, parameterization and validation of a creep deformation/rupture material constitutive model for SiC/SiC ceramic-matrix composites (CMCs

    Directory of Open Access Journals (Sweden)

    Mica Grujicic

    2016-05-01

    Full Text Available The present work deals with the development of material constitutive models for creep-deformation and creep-rupture of SiC/SiC ceramic-matrix composites (CMCs under general three-dimensional stress states. The models derived are aimed for use in finite element analyses of the performance, durability and reliability of CMC turbine blades used in gas-turbine engines. Towards that end, one set of available experimental data pertaining to the effect of stress magnitude and temperature on the time-dependent creep deformation and rupture, available in the open literature, is used to derive and parameterize material constitutive models for creep-deformation and creep-rupture. The two models derived are validated by using additional experimental data, also available in the open literature. To enable the use of the newly-developed CMC creep-deformation and creep-rupture models within a structural finite-element framework, the models are implemented in a user-material subroutine which can be readily linked with a finite-element program/solver. In this way, the performance and reliability of CMC components used in high-temperature high-stress applications, such as those encountered in gas-turbine engines can be investigated computationally. Results of a preliminary finite-element analysis concerning the creep-deformation-induced contact between a gas-turbine engine blade and the shroud are presented and briefly discussed in the last portion of the paper. In this analysis, it is assumed that: (a the blade is made of the SiC/SiC CMC; and (b the creep-deformation behavior of the SiC/SiC CMC can be represented by the creep-deformation model developed in the present work.

  19. The biomechanical behavior and host response to porcine-derived small intestine submucosa, pericardium and dermal matrix acellular grafts in a rat abdominal defect model.

    Science.gov (United States)

    Zhang, Jian; Wang, Guan Yu; Xiao, Yi Pin; Fan, Lie Ying; Wang, Qiang

    2011-10-01

    Several porcine-derived acellular biologic grafts are increasingly used in abdominal wall reconstruction due to the limitations of synthetic meshes in many clinical situations. However, relatively little is known so far about their comparative mechanical characteristics and performance after defect repair. We therefore investigated three most commonly used porcine-derived acellular biomaterials, small intestine submucosa (P-SIS), pericardium (P-PC) and acellular dermal matrix (P-ADM) immediately after prepared, and their effectiveness, biomechanical and histological characteristics in repairing full-thickness abdominal defect in a rat model. P-PC had the best native performance in the burst strength, tensile strength and ball burst among the three porcine-derived scaffolds. P-SIS showed a significantly higher water vapor transmission in comparison with P-PC or P-ADM. Abdominal wall defects in rats were all satisfied repaired with P-SIS, P-PC or P-ADM. No laxity or fistula was observed in the repaired abdominal wall in the P-SIS group up to 8 weeks after surgery. However, there was a tendency for high postoperative abdominal eventration in the P-ADM and P-PC groups as compared with the P-SIS group. With regard to overall aspects of the postoperative laxity, intra-abdominal adhesion formation, tensile stress, stretchability, and degree of tissue ingrowth in terms of collagen deposition and neovascularization, P-SIS exhibits clear advantages over P-PC as well as P-ADM after large abdominal wall defect reconstruction.

  20. Three-dimensional culture of single embryonic stem-derived neural/stem progenitor cells in fibrin hydrogels: neuronal network formation and matrix remodelling.

    Science.gov (United States)

    Bento, Ana R; Quelhas, Pedro; Oliveira, Maria J; Pêgo, Ana P; Amaral, Isabel F

    2016-12-29

    In an attempt to improve the efficacy of neural stem/progenitor cell (NSPC) based therapies, fibrin hydrogels are being explored to provide a favourable microenvironment for cell survival and differentiation following transplantation. In the present work, the ability of fibrin to support the survival, proliferation, and neuronal differentiation of NSPCs derived from embryonic stem (ES) cells under monolayer culture was explored. Single mouse ES-NSPCs were cultured within fibrin (fibrinogen concentration: 6 mg/ml) under neuronal differentiation conditions up to 14 days. The ES-NSPCs retained high cell viability and proliferated within small-sized spheroids. Neuronal differentiation was confirmed by an increase in the levels of βIII-tubulin and NF200 over time. At day 14, cell-matrix constructs mainly comprised NSPCs and neurons (46.5% βIII-tubulin(+) cells). Gamma-aminobutyric acid (GABA)ergic and dopaminergic/noradrenergic neurons were also observed, along with a network of synaptic proteins. The ES-NSPCs expressed matriptase and secreted MMP-2/9, with MMP-2 activity increasing along time. Fibronectin, laminin and collagen type IV deposition was also detected. Fibrin gels prepared with higher fibrinogen concentrations (8/10 mg/ml) were less permissive to neurite extension and neuronal differentiation, possibly owing to their smaller pore area and higher rigidity. Overall, it is shown that ES-NSPCs within fibrin are able to establish neuronal networks and to remodel fibrin through MMP secretion and extracellular matrix (ECM) deposition. This three-dimensional (3D) culture system was also shown to support cell viability, neuronal differentiation and ECM deposition of human ES-NSPCs. The settled 3D platform is expected to constitute a valuable tool to develop fibrin-based hydrogels for ES-NSPC delivery into the injured central nervous system. Copyright © 2016 John Wiley & Sons, Ltd.

  1. Adaptive Denoising Algorithm Based on the Variance Characteristics of EMD%基于 EMD 方差特性的混沌信号自适应去噪算法

    Institute of Scientific and Technical Information of China (English)

    张强; 行鸿彦

    2015-01-01

    本文利用经验模态分解算法(EMD ),研究了不同状态下混沌信号的方差特性,提出了一种EMD分解层数自适应的去噪算法.该算法根据固有模态函数(IMF)方差最大值对应层数与总分解层数的关系,能够自适应选择需处理的IMF层数,并结合提升小波在更新和预测方面的优势综合去噪,分别以Lorenz、Chen系统(加入10%-100%的高斯白噪声)和实测的IPIX雷达数据作为混沌背景噪声进行了实验研究.结果表明:在不同程度的低噪声(≤30%)环境下,与传统小波阈值去噪等方法相比,其均方误差降低了30%以上,信噪比提高了1.5 db-3.5 db ,并能有效地去除海杂波噪声,提高混沌背景下的微弱信号检测效果.%This paper studies the variance characteristics of chaotic signal in different conditions and puts forward an adaptive denoising algorithm on account of EMD decomposition layers ,by using the Empirical Mode Decomposition (EMD ) .The arithmetic can adaptively select the IMF layer which needs to be processed ,based on the relationship between the maximum variance corre-sponding layers and the total number of decomposition layers of intrinsic mode function (IMF ) ,and it also can make intergrated denosing by making use of the lifting wavelet’ s advantages in the field of updating and predicting .It carried out the experimental study ,based on the chaotic background noise from Lorenz and Chen System (adding 10% -100% white gaussian noise ) and the measured IPIX radar data .The result shows that:under varying degrees of low noise (≤30% ) ,it decreases the error of mean square by at least 30% compared with the methods such as traditional wavelet threshold denoising ,and the signal to noise ratio has increased by 1 .5db-3 .5db ,and can effectively reduce the sea clutter noise to increase the detection effect under the background of chaos .

  2. Wharton’s Jelly-Derived Mesenchymal Stromal Cells and Fibroblast-Derived Extracellular Matrix Synergistically Activate Apoptosis in a p21-Dependent Mechanism in WHCO1 and MDA MB 231 Cancer Cells In Vitro

    Directory of Open Access Journals (Sweden)

    Kevin Dzobo

    2016-01-01

    Full Text Available The tumour microenvironment plays a crucial role in tumour progression and comprises tumour stroma which is made up of different cell types and the extracellular matrix (ECM. Mesenchymal stromal cells (MSCs are part of the tumour stroma and may have conflicting effects on tumour growth. In this study we investigated the effect of Wharton’s Jelly-derived MSCs (WJ-MSCs and a fibroblast-derived ECM (fd-ECM on esophageal (WHCO1 and breast (MDA MB 231 cancer cells in vitro. Both WJ-MSCs and the fd-ECM, alone or in combination, downregulate PCNA, cyclin D1, Bcl-2, Bcl-xL, and MMPs and upregulate p53 and p21. p21 induction resulted in G2 phase cell cycle arrest and induced apoptosis in vitro. Our data suggest that p21 induction is via p53-dependent and p53-independent mechanisms in WHCO1 and MDA MB 231 cells, respectively. Vascular endothelial growth factor, Akt, and Nodal pathways were downregulated in cancer cells cocultured with WJ-MSCs. We also demonstrate that WJ-MSCs effects on cancer cells appear to be short-lived whilst the fd-ECM effect is long-lived. This study shows the influence of tumour microenvironment on cancer cell behaviour and provides alternative therapeutic targets for potential regulation of tumour cells.

  3. Wharton's Jelly-Derived Mesenchymal Stromal Cells and Fibroblast-Derived Extracellular Matrix Synergistically Activate Apoptosis in a p21-Dependent Mechanism in WHCO1 and MDA MB 231 Cancer Cells In Vitro.

    Science.gov (United States)

    Dzobo, Kevin; Vogelsang, Matjaz; Thomford, Nicholas E; Dandara, Collet; Kallmeyer, Karlien; Pepper, Michael S; Parker, M Iqbal

    2016-01-01

    The tumour microenvironment plays a crucial role in tumour progression and comprises tumour stroma which is made up of different cell types and the extracellular matrix (ECM). Mesenchymal stromal cells (MSCs) are part of the tumour stroma and may have conflicting effects on tumour growth. In this study we investigated the effect of Wharton's Jelly-derived MSCs (WJ-MSCs) and a fibroblast-derived ECM (fd-ECM) on esophageal (WHCO1) and breast (MDA MB 231) cancer cells in vitro. Both WJ-MSCs and the fd-ECM, alone or in combination, downregulate PCNA, cyclin D1, Bcl-2, Bcl-xL, and MMPs and upregulate p53 and p21. p21 induction resulted in G2 phase cell cycle arrest and induced apoptosis in vitro. Our data suggest that p21 induction is via p53-dependent and p53-independent mechanisms in WHCO1 and MDA MB 231 cells, respectively. Vascular endothelial growth factor, Akt, and Nodal pathways were downregulated in cancer cells cocultured with WJ-MSCs. We also demonstrate that WJ-MSCs effects on cancer cells appear to be short-lived whilst the fd-ECM effect is long-lived. This study shows the influence of tumour microenvironment on cancer cell behaviour and provides alternative therapeutic targets for potential regulation of tumour cells.

  4. The highly selective 5-hydroxytryptamine (5-HT)2A receptor antagonist, EMD 281014, significantly increases swimming and decreases immobility in male congenital learned helpless rats in the forced swim test.

    Science.gov (United States)

    Patel, Jignesh G; Bartoszyk, Gerd D; Edwards, Emmeline; Ashby, Charles R

    2004-04-01

    We examined the effect of the highly selective 5-hydroxytryptamine (5-HT)(2A) receptor antagonist 7-[4-[2-(4-fluoro-phenyl)-ethyl]-piperazine-1-carbonyl]-1H-indole-3-carbonitrile HCl (EMD 281014) in congenital learned helpless male rats in the forced swim test. The administration of EMD-281014 (0.3-30 mg/kg i.p.) to congenital learned helpless rats dose-dependently and significantly (at 10 and 30 mg/kg) decreased immobility and increased swimming compared to vehicle-treated animals. Thus, EMD 281014 produces effects in the forced swim test resembling those of antidepressants.

  5. Matrix metalloproteinase-9 and stromal cell-derived factor-1 act synergistically to support migration of blood-borne monocytes into the injured spinal cord.

    Science.gov (United States)

    Zhang, Haoqian; Trivedi, Alpa; Lee, Jung-Uek; Lohela, Marja; Lee, Sang Mi; Fandel, Thomas M; Werb, Zena; Noble-Haeusslein, Linda J

    2011-11-01

    The infiltration of monocytes into the lesioned site is a key event in the inflammatory response after spinal cord injury (SCI). We hypothesized that the molecular events governing the infiltration of monocytes into the injured cord involve cooperativity between the upregulation of the chemoattractant stromal cell-derived factor-1 (SDF-1)/CXCL12 in the injured cord and matrix metalloproteinase-9 (MMP-9/gelatinase B), expressed by infiltrating monocytes. SDF-1 and its receptor CXCR4 mRNAs were upregulated in the injured cord, while macrophages immunoexpressed CXCR4. When mice, transplanted with bone marrow cells from green fluorescent protein (GFP) transgenic mice, were subjected to SCI, GFP+ monocytes infiltrated the cord and displayed gelatinolytic activity. In vitro studies confirmed that SDF-1α, acting through CXCR4, expressed on bone marrow-derived macrophages, upregulated MMP-9 and stimulated MMP-9-dependent transmigration across endothelial cell monolayers by 2.6-fold. There was a reduction in F4/80+ macrophages in spinal cord-injured MMP-9 knock-out mice (by 36%) or wild-type mice, treated with the broad-spectrum MMP inhibitor GM6001 (by 30%). Mice were adoptively transferred with myeloid cells and treated with the MMP-9/-2 inhibitor SB-3CT, the CXCR4 antagonist AMD3100, or a combination of both drugs. While either drug resulted in a 28-30% reduction of infiltrated myeloid cells, the combined treatment resulted in a 45% reduction, suggesting that SDF-1 and MMP-9 function independently to promote the trafficking of myeloid cells into the injured cord. Collectively, these observations suggest a synergistic partnership between MMP-9 and SDF-1 in facilitating transmigration of monocytes into the injured spinal cord.

  6. IL-1β-induced, matrix metalloproteinase-3-regulated proliferation of embryonic stem cell-derived odontoblastic cells is mediated by the Wnt5 signaling pathway

    Energy Technology Data Exchange (ETDEWEB)

    Ozeki, Nobuaki; Hase, Naoko; Hiyama, Taiki; Yamaguchi, Hideyuki; Kawai, Rie [Department of Endodontics, School of Dentistry, Aichi Gakuin University, Nagoya, Aichi 464-8651 (Japan); Kondo, Ayami [Department of Medicinal Biochemistry, School of Pharmacy, Aichi Gakuin University, Nagoya 464-8650 (Japan); Nakata, Kazuhiko [Department of Endodontics, School of Dentistry, Aichi Gakuin University, Nagoya, Aichi 464-8651 (Japan); Mogi, Makio, E-mail: makio@dpc.agu.ac.jp [Department of Medicinal Biochemistry, School of Pharmacy, Aichi Gakuin University, Nagoya 464-8650 (Japan)

    2014-10-15

    We previously established a method for differentiating induced pluripotent stem cells and embryonic stem (ES) cells into α2 integrin-positive odontoblast-like cells. We also reported that interleukin (IL)-1β induces matrix metalloproteinase (MMP)-3-regulated cell proliferation and suppresses apoptosis in these cells, suggesting that MMP-3 plays a potentially unique physiological role in the regeneration of odontoblast-like cells. Here, we examined whether up-regulation of MMP-3 activity by IL-1β was mediated by Wnt signaling and led to increased proliferation of odontoblast-like cells. IL-1β increased mRNA and protein levels of Wnt5a, Wnt5b and the Wnt receptor Lrp5. Exogenous Wnt5a and Wnt5b were found to increase MMP-3 mRNA, protein and activity, and interestingly the rate of proliferation in these cells. Treatment with siRNAs against Wnt5a, Wnt5b and Lrp5 suppressed the IL-1β-induced increase in MMP-3 expression and suppressed cell proliferation, an effect rescued by application of exogenous Wnt5. These results demonstrate the sequential involvement of Wnt5, Lrp5 and MMP-3 in effecting IL-1β-induced proliferation of ES cell-derived odontoblast-like cells. - Highlights: • IL-1β induces Wnt5, Lrp5/Fzd9 and MMP-3 in ES cell-derived odontoblast-like cells. • IL-1β-induced Wnt5 expression results in increased cell proliferation. • Exogenous Wnt5 increases MMP-3 activity and cell proliferation. • Exogenous Wnt5 rescues IL-1β-driven proliferation with anti-Wnt5 siRNA suppression. • IL-1β-induced cell proliferation involves Wnt5, Lrp5, and MMP-3 sequentially.

  7. Human umbilical cord matrix-derived stem cells exert trophic effects on β-cell survival in diabetic rats and isolated islets

    Directory of Open Access Journals (Sweden)

    Yunting Zhou

    2015-12-01

    Full Text Available Human umbilical cord matrix-derived stem cells (uMSCs, owing to their cellular and procurement advantages compared with mesenchymal stem cells derived from other tissue sources, are in clinical trials to treat type 1 (T1D and type 2 diabetes (T2D. However, the therapeutic basis remains to be fully understood. The immunomodulatory property of uMSCs could explain the use in treating T1D; however, the mere immune modulation might not be sufficient to support the use in T2D. We thus tested whether uMSCs could exert direct trophic effects on β-cells. Infusion of uMSCs into chemically induced diabetic rats prevented hyperglycemic progression with a parallel preservation of islet size and cellularity, demonstrating the protective effect of uMSCs on β-cells. Mechanistic analyses revealed that uMSCs engrafted long-term in the injured pancreas and the engraftment markedly activated the pancreatic PI3K pathway and its downstream anti-apoptotic machinery. The pro-survival pathway activation was associated with the expression and secretion of β-cell growth factors by uMSCs, among which insulin-like growth factor 1 (IGF1 was highly abundant. To establish the causal relationship between the uMSC-secreted factors and β-cell survival, isolated rat islets were co-cultured with uMSCs in the transwell system. Co-culturing improved the islet viability and insulin secretion. Furthermore, reduction of uMSC-secreted IGF1 via siRNA knockdown diminished the protective effects on islets in the co-culture. Thus, our data support a model whereby uMSCs exert trophic effects on islets by secreting β-cell growth factors such as IGF1. The study reveals a novel therapeutic role of uMSCs and suggests that multiple mechanisms are employed by uMSCs to treat diabetes.

  8. Xeno-free culture condition for human bone marrow and umbilical cord matrix-derived mesenchymal stem/stromal cells using human umbilical cord blood serum

    Science.gov (United States)

    Esmaeli, Azadeh; Moshrefi, Mojgan; Shamsara, Ali; Eftekhar-vaghefi, Seyed Hasan; Nematollahi-mahani, Seyed Noureddin

    2016-01-01

    Background: Fetal bovine serum (FBS) is widely used in cell culture laboratories, risk of zoonotic infections and allergic side effects create obstacles for its use in clinical trials. Therefore, an alternative supplement with proper inherent growth-promoting activities is demanded. Objective: To find FBS substitute, we tested human umbilical cord blood serum (hUCS) for proliferation of human umbilical cord matrix derived mesenchymal stem cells (hUC-MSCs) and human bone marrow-derived mesenchymal cells (hBM-MSCs). Materials and Methods: Umbilical cord blood of healthy neonates, delivered by Caesarian section, was collected and the serum was separated. hUC-MSCs and hBM-MSCs were isolated and characterized by assessment of cell surface antigens by flow cytometry, alkaline phosphatase activity and osteogenic/adipogenic differentiation potential. The cells were then cultured in Iscove's Modified Dulbecco's Medium (IMDM) by conventional methods in three preparations: 1- with hUCS, 2- with FBS, and 3- without serum supplements. Cell proliferation was measured using WST-1 assay, and cell viability was assessed by trypan blue staining. Results: The cells cultured in hUCS and FBS exhibited similar morphology and mesenchymal stem cells properties. WST-1 proliferation assay data showed no significant difference between the proliferation rate of either cells following hUCS and FBS supplementation. Trypan blue exclusion dye test also revealed no significant difference for viability between hUCS and FBS groups. A significant difference was detected between the proliferation rate of stem cells cultured in serum-supplemented medium compared with serum-free medium. Conclusion: Our results indicate that human umbilical cord serum can effectively support proliferation of hBM-MSCS and hUC-MSCs in vitro and can be used as an appropriate substitute for FBS, especially in clinical studies. PMID:27738658

  9. [Effect of laminar shear stress on the expression of matrix metalloproteinases-9 in rat bone marrow-derived mesenchymal stem cells].

    Science.gov (United States)

    Chen, Longju; Sun, Xiaodong; Tang, Jie; Ding, Yan; Li, Jing; Li, Wenchun; Gong, Jian; Wang, Hanqin

    2010-12-01

    This paper was designed to investigate the effect of laminar shear stress on matrix metalloproteinase -9 (MMP-9) expression in rat bone marrow-derived mesenchymal stem cells (MSCs), and the possible signal transduction mechanism involved. Rat bone marrow MSCs were isolated and cultured, then, exposed to laminar shear stress at indicated strengths such as low (5dyne/cm2), medium (15 dyne/cm2) and high (30 dyne/cm2) via parallel plate flow chamber. RT-PCR was used to analyze the expression of MMP-9. The signaling inhibitors such as Wortmannin (PI3K specific inhabitor), SB202190 (p38MAPK specific inhabitor), and PD98059 (ERK1/2 specific inhabitor) were used to investigate the possible mechanical signal transduction pathway. The results showed: (1) The expression of MMP-9 was weak in static state, however, MMP-9 expression increased when MSCs were exposed to 15 dyne/cm2 shear stress for 2 hours, and MMP-9 expression increased with the extension of stimulating time, and it reached the peak at 24 h; (2) MSCs were stimulated by shear stress for 2 hours at different strengths (5 dyne/cm2, 15 dyne/cm2, 30 dyne/cm2), and under all these conditions, the expression of MMP-9 increased, and reached the peak at 15 dyne/cm2; (3) After MSCs were pretreated by three kinds of signal pathway inhibitors, the expression of MMP-9 did not change obviously in Wortmannin group and PD98059 group, but it was significantly inhibited in SB202190 group. This study demonstrated that shear stress could induce the expression of MMP-9 in rat bone marrow-derived mesenchymal stem cells; the amount of MMP-9 expression was closely related to stimulating time and the strengths of shear stress; and p38MAPK signal pathway played a critical role during the process.

  10. Enhancement of Matrix Metalloproteinase-2 (MMP-2) as a Potential Chondrogenic Marker during Chondrogenic Differentiation of Human Adipose-Derived Stem Cells.

    Science.gov (United States)

    Arai, Yoshie; Park, Sunghyun; Choi, Bogyu; Ko, Kyoung-Won; Choi, Won Chul; Lee, Joong-Myung; Han, Dong-Wook; Park, Hun-Kuk; Han, Inbo; Lee, Jong Hun; Lee, Soo-Hong

    2016-06-17

    Human adipose-derived stem cells (hASCs) have a capacity to undergo adipogenic, chondrogenic, and osteogenic differentiation. Recently, hASCs were applied to various fields including cell therapy for tissue regeneration. However, it is hard to predict the direction of differentiation of hASCs in real-time. Matrix metalloproteinases (MMPs) are one family of proteolytic enzymes that plays a pivotal role in regulating the biology of stem cells. MMPs secreted by hASCs are expected to show different expression patterns depending on the differentiation state of hASCs because biological functions exhibit different patterns during the differentiation of stem cells. Here, we investigated proteolytic enzyme activity, especially MMP-2 activity, in hASCs during their differentiation. The activities of proteolytic enzymes and MMP-2 were higher during chondrogenic differentiation than during adipogenic and osteogenic differentiation. During chondrogenic differentiation, mRNA expression of MMP-2 and the level of the active form of MMP-2 were increased, which also correlated with Col II. It is concluded that proteolytic enzyme activity and the level of the active form of MMP-2 were increased during chondrogenic differentiation, which was accelerated in the presence of Col II protein. According to our findings, MMP-2 could be a candidate maker for real-time detection of chondrogenic differentiation of hASCs.

  11. Plasma levels of mature brain-derived neurotrophic factor (BDNF) and matrix metalloproteinase-9 (MMP-9) in treatment-resistant schizophrenia treated with clozapine.

    Science.gov (United States)

    Yamamori, Hidenaga; Hashimoto, Ryota; Ishima, Tamaki; Kishi, Fukuko; Yasuda, Yuka; Ohi, Kazutaka; Fujimoto, Michiko; Umeda-Yano, Satomi; Ito, Akira; Hashimoto, Kenji; Takeda, Masatoshi

    2013-11-27

    Brain-derived neurotrophic factor (BDNF) regulates the survival and growth of neurons, and influences synaptic efficiency and plasticity. Peripheral BDNF levels in patients with schizophrenia have been widely reported in the literature. However, it is still controversial whether peripheral levels of BDNF are altered in patients with schizophrenia. The peripheral BDNF levels previously reported in patients with schizophrenia were total BDNF (proBDNF and mature BDNF) as it was unable to specifically measure mature BDNF due to limited BDNF antibody specificity. In this study, we examined whether peripheral levels of mature BDNF were altered in patients with treatment-resistant schizophrenia. Matrix metalloproteinase-9 (MMP-9) levels were also measured, as MMP-9 plays a role in the conversion of proBDNF to mature BDNF. Twenty-two patients with treatment-resistant schizophrenia treated with clozapine and 22 age- and sex-matched healthy controls were enrolled. The plasma levels of mature BDNF and MMP-9 were measured using ELISA kits. No significant difference was observed for mature BDNF however, MMP-9 was significantly increased in patients with schizophrenia. The significant correlation was observed between mature BDNF and MMP-9 plasma levels. Neither mature BDNF nor MMP-9 plasma levels were associated clinical variables. Our results do not support the view that peripheral BDNF levels are associated with schizophrenia. MMP-9 may play a role in the pathophysiology of schizophrenia and serve as a biomarker for schizophrenia.

  12. Apoptosis signal-regulating kinase 1 is involved in brain-derived neurotrophic factor (BDNF)-enhanced cell motility and matrix metalloproteinase 1 expression in human chondrosarcoma cells.

    Science.gov (United States)

    Lin, Chih-Yang; Chang, Sunny Li-Yun; Fong, Yi-Chin; Hsu, Chin-Jung; Tang, Chih-Hsin

    2013-07-25

    Chondrosarcoma is the primary malignancy of bone that is characterized by a potent capacity to invade locally and cause distant metastasis, and is therefore associated with poor prognoses. Chondrosarcoma further shows a predilection for metastasis to the lungs. The brain-derived neurotrophic factor (BDNF) is a small molecule in the neurotrophin family of growth factors that is associated with the disease status and outcome of cancers. However, the effect of BDNF on cell motility in human chondrosarcoma cells is mostly unknown. Here, we found that human chondrosarcoma cell lines had significantly higher cell motility and BDNF expression compared to normal chondrocytes. We also found that BDNF increased cell motility and expression of matrix metalloproteinase-1 (MMP-1) in human chondrosarcoma cells. BDNF-mediated cell motility and MMP-1 up-regulation were attenuated by Trk inhibitor (K252a), ASK1 inhibitor (thioredoxin), JNK inhibitor (SP600125), and p38 inhibitor (SB203580). Furthermore, BDNF also promoted Sp1 activation. Our results indicate that BDNF enhances the migration and invasion activity of chondrosarcoma cells by increasing MMP-1 expression through a signal transduction pathway that involves the TrkB receptor, ASK1, JNK/p38, and Sp1. BDNF thus represents a promising new target for treating chondrosarcoma metastasis.

  13. Healthy and adverse effects of plant-derived functional metabolites: the need of revealing their content and bioactivity in a complex food matrix.

    Science.gov (United States)

    Lavecchia, Teresa; Rea, Giuseppina; Antonacci, Amina; Giardi, Maria T

    2013-01-01

    In recent years, both food quality and its effect on human health have become a fundamental issue all over the world. As a consequence of this new and increased awareness, American, European, and Asian policymakers have strongly encouraged the research programs on food quality and safety thematic. Attempts to improve human health and to satisfy people's desire for healthcare without intake of pharmaceuticals, has led the food industry to focus attention on functional or nutraceutical food. For a long time, compounds with nutraceutical activity have been produced chemically, but the new demands for a sustainable life have gradually led the food industry to move towards natural compounds, mainly those derived from plants. Many phytochemicals are known to promote good health, but, sometimes, undesirable effects are also reported. Furthermore, several products present on the market show few benefits and sometimes even the reverse - unhealthy effects; the evidence of efficacy is often unconvincing and epidemiological studies are necessary to prove the truth of their claims. Therefore, there is a need for reliable analytical control systems to measure the bioactivity, content, and quality of these additives in the complex food matrix. This review describes the most widespread nutraceutics and an analytical control of the same using recently developed biosensors which are promising candidates for routine control of functional foods.

  14. Wnt16 Signaling Is Required for IL-1β-Induced Matrix Metalloproteinase-13-Regulated Proliferation of Human Stem Cell-Derived Osteoblastic Cells

    Directory of Open Access Journals (Sweden)

    Nobuaki Ozeki

    2016-02-01

    Full Text Available We established a differentiation method for homogeneous α7 integrin-positive human skeletal muscle stem cell (α7+hSMSC-derived osteoblast-like (α7+hSMSC-OB cells, and found that interleukin (IL-1β induces matrix metalloproteinase (MMP-13-regulated proliferation of these cells. These data suggest that MMP-13 plays a potentially unique physiological role in the regeneration of osteoblast-like cells. Here, we examined whether up-regulation of MMP-13 activity by IL-1β was mediated by Wingless/int1 (Wnt signaling and increased the proliferation of osteoblast-like cells. IL-1β increased the mRNA and protein levels of Wnt16 and the Wnt receptor Lrp5/Fzd2. Exogenous Wnt16 was found to increase MMP-13 mRNA, protein and activity, and interestingly, the proliferation rate of these cells. Treatment with small interfering RNAs against Wnt16 and Lrp5 suppressed the IL-1β-induced increase in cell proliferation. We revealed that a unique signaling cascade IL-1β→Wnt16→Lrp5→MMP-13, was intimately involved in the proliferation of osteoblast-like cells, and suggest that IL-1β-induced MMP-13 expression and changes in cell proliferation are regulated by Wnt16.

  15. Enhancement of Matrix Metalloproteinase-2 (MMP-2 as a Potential Chondrogenic Marker during Chondrogenic Differentiation of Human Adipose-Derived Stem Cells

    Directory of Open Access Journals (Sweden)

    Yoshie Arai

    2016-06-01

    Full Text Available Human adipose-derived stem cells (hASCs have a capacity to undergo adipogenic, chondrogenic, and osteogenic differentiation. Recently, hASCs were applied to various fields including cell therapy for tissue regeneration. However, it is hard to predict the direction of differentiation of hASCs in real-time. Matrix metalloproteinases (MMPs are one family of proteolytic enzymes that plays a pivotal role in regulating the biology of stem cells. MMPs secreted by hASCs are expected to show different expression patterns depending on the differentiation state of hASCs because biological functions exhibit different patterns during the differentiation of stem cells. Here, we investigated proteolytic enzyme activity, especially MMP-2 activity, in hASCs during their differentiation. The activities of proteolytic enzymes and MMP-2 were higher during chondrogenic differentiation than during adipogenic and osteogenic differentiation. During chondrogenic differentiation, mRNA expression of MMP-2 and the level of the active form of MMP-2 were increased, which also correlated with Col II. It is concluded that proteolytic enzyme activity and the level of the active form of MMP-2 were increased during chondrogenic differentiation, which was accelerated in the presence of Col II protein. According to our findings, MMP-2 could be a candidate maker for real-time detection of chondrogenic differentiation of hASCs.

  16. Delivery of an engineered HGF fragment in an extracellular matrix-derived hydrogel prevents negative LV remodeling post-myocardial infarction.

    Science.gov (United States)

    Sonnenberg, Sonya B; Rane, Aboli A; Liu, Cassie J; Rao, Nikhil; Agmon, Gillie; Suarez, Sophia; Wang, Raymond; Munoz, Adam; Bajaj, Vaibhav; Zhang, Shirley; Braden, Rebecca; Schup-Magoffin, Pamela J; Kwan, Oi Ling; DeMaria, Anthony N; Cochran, Jennifer R; Christman, Karen L

    2015-03-01

    Hepatocyte growth factor (HGF) has been shown to have anti-fibrotic, pro-angiogenic, and cardioprotective effects; however, it is highly unstable and expensive to manufacture, hindering its clinical translation. Recently, a HGF fragment (HGF-f), an alternative c-MET agonist, was engineered to possess increased stability and recombinant expression yields. In this study, we assessed the potential of HGF-f, delivered in an extracellular matrix (ECM)-derived hydrogel, as a potential treatment for myocardial infarction (MI). HGF-f protected cardiomyocytes from serum-starvation and induced down-regulation of fibrotic markers in whole cardiac cell isolate compared to the untreated control. The ECM hydrogel prolonged release of HGF-f compared to collagen gels, and in vivo delivery of HGF-f from ECM hydrogels mitigated negative left ventricular (LV) remodeling, improved fractional area change (FAC), and increased arteriole density in a rat myocardial infarction model. These results indicate that HGF-f may be a viable alternative to using recombinant HGF, and that an ECM hydrogel can be employed to increase growth factor retention and efficacy.

  17. Different effects of energy dependent irradiation of red and green lights on proliferation of human umbilical cord matrix-derived mesenchymal cells.

    Science.gov (United States)

    Dehghani Soltani, Samereh; Babaee, Abdolreza; Shojaei, Mohammad; Salehinejad, Parvin; Seyedi, Fatemeh; JalalKamali, Mahshid; Nematollahi-Mahani, Seyed Noureddin

    2016-02-01

    Light-emitting diodes (LED) have recently been introduced as a potential factor for proliferation of various cell types in vitro. Nowadays, stem cells are widely used in regenerative medicine. Human umbilical cord matrix-derived mesenchymal (hUCM) cells can be more easily isolated and cultured than adult mesenchymal stem cells. The aim of this study was to evaluate the effect of red and green lights produced by LED on the proliferation of hUCM cells. hUCM cells were isolated from the umbilical cord, and light irradiation was applied at radiation energies of 0.318, 0.636, 0.954, 1.59, 3.18, 6.36, 9.54, and 12.72 J/cm(2). Irradiation of the hUCM cells shows a significant (p cell number as compared to controls after 40 h. In addition, cell proliferation on days 7, 14, and 21 in irradiated groups were significantly (p red and green lights irradiation to promote proliferation of hUCM cells in vitro. The energy applied to the cells through LED irradiation is an effective factor with paradoxical alterations. Green light inserted a much profound effect at special dosages than red light.

  18. Maturation of human embryonic stem cell-derived cardiomyocytes (hESC-CMs) in 3D collagen matrix: Effects of niche cell supplementation and mechanical stimulation.

    Science.gov (United States)

    Zhang, W; Kong, C W; Tong, M H; Chooi, W H; Huang, N; Li, R A; Chan, B P

    2017-02-01

    Cardiomyocytes derived from human embryonic stem cells (hESC-CMs) are regarded as a promising source for regenerative medicine, drug testing and disease modeling. Nevertheless, cardiomyocytes are immature in terms of their contractile structure, metabolism and electrophysiological properties. Here, we fabricate cardiac muscle strips by encapsulating hESC-CMs in collagen-based biomaterials. Supplementation of niche cells at 3% to the number of hESC-CMs enhance the maturation of the hESC-CMs in 3D tissue matrix. The benefits of adding mesenchymal stem cells (MSCs) are comparable to that of adding fibroblasts. These two cell types demonstrate similar effects in promoting the compaction and cell spreading, as well as expression of maturation markers at both gene and protein levels. Mechanical loading, particularly cyclic stretch, produces engineered cardiac tissues with higher maturity in terms of twitch force, elastic modulus, sarcomere length and molecular signature, when comparing to static stretch or non-stretched controls. The current study demonstrates that the application of niche cells and mechanical stretch both stimulate the maturation of hESC-CMs in 3D architecture. Our results therefore suggest that this 3D model can be used for in vitro cardiac maturation study.

  19. Joint application of feature extraction based on EMD-AR strategy and multi-class classifier based on LS-SVM in EMG motion classification

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    This paper presents an effective and efficient combination of feature extraction and multi-class classifier for motion classification by analyzing the surface electromyografic (sEMG) signals. In contrast to the existing methods, considering the non-stationary and nonlinear characteristics of EMG signals, to get the more separable feature set, we introduce the empirical mode decomposition (EMD) to decompose the original EMG signals into several intrinsic mode functions (IMFs) and then compute the coefficients of autoregressive models of each IMF to form the feature set. Based on the least squares support vector machines (LS-SVMs), the multi-class classifier is designed and constructed to classify various motions. The results of contrastive experiments showed that the accuracy of motion recognition is improved with the described classification scheme. Furthermore,compared with other classifiers using different features, the excellent performance indicated the potential of the SVM techniques embedding the EMD-AR kernel in motion classification.

  20. Diagnostic value of platelet derived growth factor-BB, transforming growth factor-β1,matrix metalloproteinase-1, and tissue inhibitor of matrix metalloproteinase-1 in serum and peripheral blood mononuclear cells for hepatic fibrosis

    Institute of Scientific and Technical Information of China (English)

    Bin-Bin Zhang; Wei-Min Cai; Hong-Lei Weng; Zhong-Rong Hu; Jun Lu; Min Zheng; Rong-Hua Liu

    2003-01-01

    AIM: Noninvasive diagnosis of hepatic fibrosis has become the focus because of the limited biopsy, especially in the surveillance of treatment and in screening hepatic fibrosis.Recently, regulatory elements involved in liver fibrosis, such as platelet derived growth factor-BB (PDGF-BB), transforming growth factor-β1 (TGF-β1), matrix metalloproteinase-1 (MMP-1), and tissue inhibitor of matrix metalloproteinase-1 (TIMP-1), have been studied extensively. To determine whether these factors or enzymes could be used as the indices for the diagnosis of hepatic fibrosis, we investigated them by means of receiver operating characteristic (ROC) curve.METHODS: Serum samples from sixty patients with chronic viral hepatitis B and twenty healthy blood donors were assayed to determine the level of PDGF-BB, TGF-β1, MMP-1, and TIMP-1 with ELISA, and HA, PCIII, C-IV, and LN level with RIA. The message RNA (mRNA) expression of TIMP-1 and MMP-1 in peripheral blood mononuclear cells (PBMCs) was detected by RT-PCR and Northern blot hybridization. Liver biopsy was performed in all patients.The biopsy samples were histopathologically examined. The trial was double-blind controlled.RESULTS: The serum level of PDGF-BB, TIMP-1, the ratio of TIMP-1 and MMP-1 (TIMP-1/MMP-1), mRNA expression of TIMP-1 (TIMP-1mRNA), and the ratio of TIMP-1mRNA and MMP-1mRNA (TIMP-1mRNA/MMP-1mRNA) in patients was significantly higher than those in the healthy blood donors (t=2.514-11.435, P=0.000-0.016). The serum level of PDGF-BB, TIMP-1, TIMP-1/MMP-1, and TIMP-1mRNA was positively correlated with fibrosis stage and inflammation grade (r=0.239-0.565, P=0.000-0.033), while the serum level of MMP-1 was negatively correlated with fibrosis stage and inflammation grade, and TIMP-1mRNA/MMP-1mRNA was positively correlated with inflammation grade. Through the analysis by ROC curve, serum PDGF-BB was the most valuable marker, and its sensitivity was the highest among the nine indices. The markers with the highest

  1. The Multi-Frequency Correlation Between Eua and sCER Futures Prices: Evidence from the Emd Approach

    Science.gov (United States)

    Zhang, Yue-Jun; Huang, Yi-Song

    2015-05-01

    Currently European Union Allowances (EUA) and secondary Certified Emission Reduction (sCER) have become two dominant carbon trading assets for investors and their linkage attracts much attention from academia and practitioners in recent years. Under this circumstance, we use the empirical mode decomposition (EMD) approach to decompose the two carbon futures contract prices and discuss their correlation from the multi-frequency perspective. The empirical results indicate that, first, the EUA and sCER futures price movements can be divided into those triggered by the long-term, medium-term and short-term market impacts. Second, the price movements in the EUA and sCER futures markets are primarily caused by the long-term impact, while the short-term impact can only explain a small fraction. Finally, the long-term (short-term) effect on EUA prices is statistically uncorrelated with the short-term (long-term) effect of sCER prices, and there is a medium or strong lead-and-lag correlation between the EUA and sCER price components with the same time scales. These results may provide some important insights of price forecast and arbitraging activities for carbon futures market investors, analysts and regulators.

  2. Fault diagnostic tests research of ball screw based on inner servo information and EMD-PNN network%基于内部伺服信息和EMD-PNN网络的滚珠丝杠副故障诊断试验研

    Institute of Scientific and Technical Information of China (English)

    杜兴苗; 谭继文; 徐卫晓; 孙显彬

    2015-01-01

    提出了一种利用光栅尺和编码器采集丝杠内部伺服信息的方法;针对滚珠丝杠副故障信号的非线性、非平稳性特征,引入经验模态分解法(EMD),对丝杠4种故障状态下的内部伺服信息进行时频域分析,并将峰度、频率、方差等时、频域特征组成原始特征集,以该特征集为输入,建立概率神经网络(PNN)模型,对滚珠丝杠副的故障状态进行模式识别.通过分析比较EMD-PNN与EMD-BP两种网络模型的性能和诊断结果,验证了EMD-PNN网络模型对滚珠丝杠副故障诊断的优越性及可行性.

  3. 2010年电解二氧化锰市场回顾和展望%The Review and Forecast of 2010 EMD Market

    Institute of Scientific and Technical Information of China (English)

    李同庆

    2011-01-01

    简要评述了2010年全球电解二氧化锰的市场,指出在欧盟、美国和日本实施反倾销措施的形势下,电解二氧化锰市场形成了新的格局.展望了未来的发展趋势,指出电动汽车的迅速发展,正有力地推动着锂离子动力电池产业的发展和壮大,为EMD开辟了极具重要意义的新应用领域,其市场前景将无可限量.%The global market situation of Electrolytic Manganese Dioxide in 2010 is reviewed. The author points out that a new pattern of global EMD market emerges in the following the anti-dumping measures imposed by the EU, America and Japan. The prospect of EMD in the future is reviewed. The author points out that the rapid development in EV field is strongly pushing forward the development of Li ion battery industry, strategically expanding the new application for EMD with unlimited market potential.

  4. EMD Based Multi-scale Model for High Resolution Image Fusion%基于经验模态分解的高分辨率影像融合

    Institute of Scientific and Technical Information of China (English)

    王坚; 张继贤; 刘正军

    2008-01-01

    High resolution image fusion is a significant focus in the field of image processing. A new image fusion model is presented based on the characteristic level of empirical mode decomposition (EMD). The intensity hue saturation (IHS) trans- form of the multi-spectral image first gives the intensity image. Thereafter, the 2D EMD in terms of row-column extension of the 1D EMD model is used to decompose the detailed scale image and coarse scale image from the high-resolution band image and the intensity image. Finally, a fused intensity image is obtained by reconstruction with high frequency of the high-resolution image and low frequency of the intensity image and IHS inverse transform result in the fused image. After pre- senting the EMD principle, a multi-scale decomposition and reconstruction algorithm of 2D EMD is defined and a fusion tech- nique scheme is advanced based on EMD. Panchromatic band and multi-spectral band 3,2,1 of Quickbird are used to assess the quality of the fusion algorithm. After selecting the appropriate intrinsic mode function (IMF) for the merger on the basis of EMD analysis on specific row (column) pixel gray value series, the fusion scheme gives a fused image, which is compared with generally used fusion algorithms (wavelet, IHS, Brovey). The objectives of image fusion include enhancing the visibility of the image and improving the spatial resolution and the spectral information of the original images. To assess quality of an image after fusion, information entropy and standard deviation are applied to assess spatial details of the fused images and correlation coefficient, bias index and warping degree for measuring distortion between the original image and fused image in terms of spectral information. For the proposed fusion algorithm, better results are obtained when EMD algorithm is used to perform the fusion experience.

  5. Extracellular matrix gel is necessary for in vitro cultivation of insulin producing cells from human umbilical cord blood derived mesenchymal stem cells

    Institute of Scientific and Technical Information of China (English)

    GAO Feng; WU De-quan; HU Yan-hua; JIN Guang-xin

    2008-01-01

    Background Pancreatic islet cell transplantation is an effective approach to treat type 1 diabetes. However, this therapy is not widely used because of the severe shortage of transplantable donor islets. This study investigated whether mesenchymal stem cells (MSCs) derived from human umbilical cord blood (UCB) could be transdifferentiated into insulin producing cells in vitro and the role of extracellular matrix (ECM) gel in this procedure.Methods Human UCB samples were collected and MSCs were isolated. MSCs specific marker proteins were analyzed by a flow cytometer. The capacities of osteoblast and adipocyte to differentiate were tested. Differentiation into islet like cell was induced by a 15-day protocol with or without ECM gel. Pancreatic characteristics were evaluated with immunofluorescence, reverse transcription polymerase chain reaction (RT-PCR) and flow cytometry. Insulin content and release in response to glucose stimulation were detected with chemiluminescent immunoassay system.Results Sixteen MSCs were isolated from 42 term human UCB units (38%). Human UCB-MSCs expressed MSCs specific markers and could be induced in vitro into osteoblast and adipocyte. Islet like cell clusters appeared about 9 days after pancreatic differentiation in the inducing system with ECM gel. The insulin positive cells accounted for (25.2±3.4)% of the induced cells. The induced cells expressed islet related genes and hormones, but were not very responsive to glucose challenge. When MSCs were induced without ECM gel, clusters formation and secretion of functional islet proteins could not be observed.Conclusions Human UCB-MSCs can differentiate into islet like cells in vitro and ECM gel plays an important role in pancreatic endocrine cell maturation and formation of three dimensional structures.

  6. Influence of enamel matrix derivative (Emdogain) and sodium fluoride on the healing process in delayed tooth replantation: histologic and histometric analysis in rats.

    Science.gov (United States)

    Poi, Wilson Roberto; Carvalho, Roberta Martinelli; Panzarini, Sônia Regina; Sonoda, Celso Koogi; Manfrin, Thais Mara; Rodrigues, Thais da Silveira

    2007-02-01

    Although it has already been shown that enamel matrix derivative (Emdogain) promotes periodontal regeneration in the treatment of intrabony periodontal defects, there is little information concerning its regenerative capacity in cases of delayed tooth replantation. To evaluate the alterations in the periodontal healing of replanted teeth after use of Emdogain, the central incisors of 24 Wistar rats (Rattus norvegicus albinus) were extracted and left on the bench for 6 h. Thereafter, the dental papilla and the enamel organ of each tooth were sectioned for pulp removal by a retrograde way and the canal was irrigated with 1% sodium hypochlorite. The teeth were assigned to two groups: in group I, root surface was treated with 1% sodium hypochlorite for 10 min (changing the solution every 5 min), rinsed with saline for 10 min and immersed in 2% acidulated-phosphate sodium fluoride for 10 min; in group II, root surfaces were treated in the same way as described above, except for the application of Emdogain instead of sodium fluoride. The teeth were filled with calcium hydroxide (in group II right before Emdogain was applied) and replanted. All animals received antibiotic therapy. The rats were killed by anesthetic overdose 10 and 60 days after replantation. The pieces containing the replanted teeth were removed, fixated, decalcified and paraffin-embedded. Semi-serial 6-microm-thick sections were obtained and stained with hematoxylin and eosin for histologic and histometric analyses. The use of 2% acidulated-phosphate sodium fluoride provided more areas of replacement resorption. The use of Emdogain resulted in more areas of ankylosis and was therefore not able to avoid dentoalveolar ankylosis. It may be concluded that neither 2% acidulated-phosphate sodium fluoride nor Emdogain were able to prevent root resorption in delayed tooth replantation in rats.

  7. Organ heterogeneity of host-derived matrix metalloproteinase expression and its involvement in multiple-organ metastasis by lung cancer cell lines.

    Science.gov (United States)

    Shiraga, Minoru; Yano, Seiji; Yamamoto, Akihiko; Ogawa, Hirohisa; Goto, Hisatsugu; Miki, Toyokazu; Miki, Keisuke; Zhang, Helong; Sone, Saburo

    2002-10-15

    Cancer metastasis is tightly regulated by the interaction of tumor cells and host organ microenvironments. Matrix metalloproteinases (MMPs), produced by both tumor cells and host stromal cells, play a central role in tumor invasion and angiogenesis. We determined whether metastatic potential of lung cancer to multiple organs is dependent solely on the expression of MMPs by tumor cells, using two metastasis models of human lung cancer cell lines expressing various levels of MMPs and a MMP inhibitor (ONO-4817). In the lung metastasis model, tumor cells (PC14, PC14PE6, H226, A549) inoculated i.v. into nude or SCID mice metastasized only in the lung. In the multiple-organ metastasis model, tumor cells (RERF-LC-AI, SBC-3/DOX, H69/VP, which express low levels of MMPs) inoculated i.v. into natural killer cell-depleted SCID mice metastasized into the liver, kidneys, and systemic lymph nodes. Film in situ zymography analysis revealed that the nontumor parenchyma of the lung had no gelatinolytic activity, whereas gelatinolytic activity of the liver and kidney was high and low, respectively. In the lung metastasis model, gelatinolytic activity of lung nodules directly correlated with the in vitro expression of MMP-2 and MMP-9 by tumor cells. Inhibition of MMP activity by ONO-4817 suppressed lung metastasis by the cell lines that expressed MMPs, but not those that did not express MMP, via the inhibition of MMP activity of lung tumors. In the multiple-organ metastasis model, liver parenchyma, but not liver nodules, showed gelatinolytic activity. The MMP inhibition reduced metastasis to the liver, but not to the kidney or lymph nodes, via inhibition of MMP activity of liver parenchyma. These findings suggest that MMP expression varies among the host organ microenvironments and that stromal MMPs may promote metastasis of lung cancer. Therefore, antimetastatic effects based on MMP inhibition may be dependent on MMPs derived not only from tumor cells but also from organ

  8. Structure and barrier properties of human embryonic stem cell-derived retinal pigment epithelial cells are affected by extracellular matrix protein coating.

    Science.gov (United States)

    Sorkio, Anni; Hongisto, Heidi; Kaarniranta, Kai; Uusitalo, Hannu; Juuti-Uusitalo, Kati; Skottman, Heli

    2014-02-01

    Extracellular matrix (ECM) interactions play a vital role in cell morphology, migration, proliferation, and differentiation of cells. We investigated the role of ECM proteins on the structure and function of human embryonic stem cell-derived retinal pigment epithelial (hESC-RPE) cells during their differentiation and maturation from hESCs into RPE cells in adherent differentiation cultures on several human ECM proteins found in native human Bruch's membrane, namely, collagen I, collagen IV, laminin, fibronectin, and vitronectin, as well as on commercial substrates of xeno-free CELLstart™ and Matrigel™. Cell pigmentation, expression of RPE-specific proteins, fine structure, as well as the production of basal lamina by hESC-RPE on different protein coatings were evaluated after 140 days of differentiation. The integrity of hESC-RPE epithelium and barrier properties on different coatings were investigated by measuring transepithelial resistance. All coatings supported the differentiation of hESC-RPE cells as demonstrated by early onset of cell pigmentation and further maturation to RPE monolayers after enrichment. Mature RPE phenotype was verified by RPE-specific gene and protein expression, correct epithelial polarization, and phagocytic activity. Significant differences were found in the degree of RPE cell pigmentation and tightness of epithelial barrier between different coatings. Further, the thickness of self-assembled basal lamina and secretion of the key ECM proteins found in the basement membrane of the native RPE varied between hESC-RPE cultured on compared protein coatings. In conclusion, this study shows that the cell culture substrate has a major effect on the structure and basal lamina production during the differentiation and maturation of hESC-RPE potentially influencing the success of cell integrations and survival after cell transplantation.

  9. Enamel matrix derivative in propylene glycol alginate for treatment of infrabony defects with or without systemic doxycycline: 12- and 24-month results.

    Science.gov (United States)

    Eickholz, Peter; Röllke, Lasse; Schacher, Beate; Wohlfeil, Martin; Dannewitz, Bettina; Kaltschmitt, Jens; Krieger, Jörg K; Krigar, Diana M; Reitmeir, Peter; Kim, Ti-Sun

    2014-05-01

    This aim of this study is to compare regenerative therapy of infrabony defects with and without administration of post-surgical systemic doxycycline (DOXY) 12 and 24 months after therapy. In each of 57 patients, one infrabony defect (depth ≥ 4 mm) was treated regeneratively using enamel matrix derivative at two centers (Frankfurt am Main and Heidelberg). By random assignment, patients received either 200 mg DOXY per day or placebo (PLAC) for 7 days after surgery. Twelve and 24 months after surgery, clinical parameters (probing depths [PDs] and vertical clinical attachment level [CAL-V]) and standardized radiographs were obtained. Missing data were managed according to the last observation carried forward. Data of 57 patients (DOXY: 28; PLAC: 29) were analyzed (26 males and 31 females; mean age: 52 ± 10.2 years; 13 smokers). In both groups, significant (P DOXY: 3.7 ± 2.2 mm; PLAC: 3.4 ± 1.7 mm), CAL-V gain (DOXY: 2.7 ± 1.9 mm; PLAC: 3.0 ± 1.9 mm), and bone fill (DOXY: 1.6 ± 2.7 mm; PLAC: 1.8 ± 3.0 mm) were observed 24 months after surgery. However, the differences between both groups failed to be statistically significant (PD: P = 0.574; CAL-V: P = 0.696; bone fill: P = 0.318). Systemic DOXY, 200 mg/day for 7 days, after regenerative therapy of infrabony defects did not result in better PD reduction, CAL-V gain, or radiographic bone fill compared with PLAC 12 and 24 months after surgery, which may be attributable to low power and, thus, random chance.

  10. Matrix analysis

    CERN Document Server

    Bhatia, Rajendra

    1997-01-01

    A good part of matrix theory is functional analytic in spirit. This statement can be turned around. There are many problems in operator theory, where most of the complexities and subtleties are present in the finite-dimensional case. My purpose in writing this book is to present a systematic treatment of methods that are useful in the study of such problems. This book is intended for use as a text for upper division and gradu­ ate courses. Courses based on parts of the material have been given by me at the Indian Statistical Institute and at the University of Toronto (in collaboration with Chandler Davis). The book should also be useful as a reference for research workers in linear algebra, operator theory, mathe­ matical physics and numerical analysis. A possible subtitle of this book could be Matrix Inequalities. A reader who works through the book should expect to become proficient in the art of deriving such inequalities. Other authors have compared this art to that of cutting diamonds. One first has to...

  11. [Co(salen)] derived Co/Co3O4 nanoparticle@carbon matrix as high-performance electrode for energy storage applications

    Science.gov (United States)

    Duraisamy, E.; Gurunathan, P.; Das, Himadri T.; Ramesha, K.; Elumalai, P.

    2017-03-01

    Cobalt/cobalt oxide nanoparticle-embedded in a carbon matrix was synthesized by one spot pyrolysis of cobalt salen complex [Co(salen)] at 800 °C in an argon atmosphere. The X-ray diffraction studies confirmed the presence of Co and Co3O4 in the carbon matrix. The SEM and TEM observations showed the homogeneous distribution of the Co/Co3O4 grains on the carbon matrix. Cyclic voltammograms and galvanostatic charge-discharge studies done on the CR2032 coin cell confirmed that the Co/Co3O4@carbon matrix was electrochemically active. A stable specific capacity as high as 1000 mA h g-1 has been observed over 50 charge-discharge cycles at C/5 rate. It is believed that the carbon matrix acted both as a spacer to accommodate volume changes during Li intercalation-deintercalation process and also as conductive network leading to the excellent electrochemical performance of the Co/Co3O4@carbon matrix. Further, supercapacitor studies revealed that a specific capacitance of 615 F g-1 at 1 A g-1 has been exhibited by the Co/Co3O4@carbon matrix electrode in 1 M KOH with high Coulombic efficiency (92%) as well as excellent cycling stability for 5000 cycles.

  12. On the Matrix Formulation of Kaiser's Varimax Criterion.

    Science.gov (United States)

    Neudecker, H.

    1981-01-01

    A full-fledged matrix derivation of Sherin's matrix formulation of Kaiser's varimax criterion is provided. Matrix differential calculus is used in conjunction with the Hadamard (or Schur) matrix product. Two results on Hadamard products are presented. (Author/JKS)

  13. Platelet-derived growth factor-D modulates extracellular matrix homeostasis and remodeling through TIMP-1 induction and attenuation of MMP-2 and MMP-9 gelatinase activities

    Energy Technology Data Exchange (ETDEWEB)

    Borkham-Kamphorst, Erawan, E-mail: ekamphorst@ukaachen.de; Alexi, Pascal; Tihaa, Lidia; Haas, Ute; Weiskirchen, Ralf, E-mail: rweiskirchen@ukaachen.de

    2015-02-13

    Platelet-derived growth factor-D (PDGF-D) is a more recent recognized growth factor involved in the regulation of several cellular processes, including cell proliferation, transformation, invasion, and angiogenesis by binding to and activating its cognate receptor PDGFR-β. After bile duct ligation or in the carbon tetrachloride-induced hepatic fibrosis model{sub ,} PDGF-D showed upregulation comparable to PDGF-B. Moreover, adenoviral PDGF-D gene transfer induced hepatic stellate cell proliferation and liver fibrosis. We here investigated the molecular mechanism of PDGF-D involvement in liver fibrogenesis. Therefore, the GRX mouse cell line was stimulated with PDGF-D and evaluated for fibrotic markers and PDGF-D signaling pathways in comparison to the other PDGF isoforms. We found that PDGF-D failed to enhance Col I and α-smooth muscle actin (α-SMA) production but has capacity to upregulate expression of the tissue inhibitor of metalloprotease 1 (TIMP-1) resulting in attenuation of MMP-2 and MMP-9 gelatinase activity as indicated by gelatinase zymography. This phenomenon was restored through application of a PDGF-D neutralizing antibody. Unexpectedly, PDGF-D incubation decreased both PDGFR-α and -β in mRNA and protein levels, and PDGF-D phosphorylated typrosines specific for PDGFR-α and -β. We conclude that PDGF-D intensifies fibrogenesis by interfering with the fibrolytic activity of the TIMP-1/MMP system and that PDGF-D signaling is mediated through both PDGF-α and -β receptors. - Highlights: • PDGF-D signals through PDGF receptor type α and β. • PDGF-D modulates extracellular matrix homeostasis and remodeling. • Like PDGF-B, PDGF-D triggers phosphorylation of PLC-γ, Akt/PKB, JNK, ERK1/2, and p38. • PDGF-D induces TIMP-1 expression through ERK and p38 MAPK. • PDGF-D attenuates MMP-2 and MMP-9 gelatinase activities.

  14. Rapid Chondrocyte Isolation for Tissue Engineering Applications: The Effect of Enzyme Concentration and Temporal Exposure on the Matrix Forming Capacity of Nasal Derived Chondrocytes

    Directory of Open Access Journals (Sweden)

    Srujana Vedicherla

    2017-01-01

    Full Text Available Laboratory based processing and expansion to yield adequate cell numbers had been the standard in Autologous Disc Chondrocyte Transplantation (ADCT, Allogeneic Juvenile Chondrocyte Implantation (NuQu®, and Matrix-Induced Autologous Chondrocyte Implantation (MACI. Optimizing cell isolation is a key challenge in terms of obtaining adequate cell numbers while maintaining a vibrant cell population capable of subsequent proliferation and matrix elaboration. However, typical cell yields from a cartilage digest are highly variable between donors and based on user competency. The overall objective of this study was to optimize chondrocyte isolation from cartilaginous nasal tissue through modulation of enzyme concentration exposure (750 and 3000 U/ml and incubation time (1 and 12 h, combined with physical agitation cycles, and to assess subsequent cell viability and matrix forming capacity. Overall, increasing enzyme exposure time was found to be more detrimental than collagenase concentration for subsequent viability, proliferation, and matrix forming capacity (sGAG and collagen of these cells resulting in nonuniform cartilaginous matrix deposition. Taken together, consolidating a 3000 U/ml collagenase digest of 1 h at a ratio of 10 ml/g of cartilage tissue with physical agitation cycles can improve efficiency of chondrocyte isolation, yielding robust, more uniform matrix formation.

  15. Mixed Fibronectin-Derived Peptides Conjugated to a Chitosan Matrix Effectively Promotes Biological Activities through Integrins, α4β1, α5β1, αvβ3, and Syndecan

    Directory of Open Access Journals (Sweden)

    Hozumi Kentaro

    2016-11-01

    Full Text Available Mimicking the biological function of the extracellular matrix is an approach to developing cell adhesive biomaterials. The RGD peptide, derived from fibronectin (Fn, mainly binds to integrin αvβ3 and has been widely used as a cell adhesive peptide on various biomaterials. However, cell adhesion to Fn is thought to be mediated by several integrin subtypes and syndecans. In this study, we synthesized an RGD-containing peptide (FIB1 and four integrin α4β1-binding-related motif-containing peptides (LDV, IDAPS, KLDAPT, and PRARI and constructed peptide-chitosan matrices. The FIB1-chitosan matrix promoted human dermal fibroblast (HDF attachment, and the C-terminal elongated PRARI (ePRARI-C-conjugated chitosan matrix significantly promoted HDF attachment through integrin α4β1 and syndecan binding. Next, we constructed a mixed ePRARI-C- and FIB1-chitosan matrix to develop a Fn mimetic biomaterial. The mixed ePRARI-C/FIB1-chitosan matrix promoted significantly better cell attachment and neurite outgrowth compared to those of either ePRARI-C- or FIB1-chitosan matrices. HDF adhesion to the ePRARI-C/FIB1-chitosan matrix was mediated by integrin, α4β1, α5β1, and αvβ3, similar to HDF adhesion to Fn. These data suggest that an ePRARI-C/FIB1-chitosan matrix can be used as a tool to analyze the multiple functions of Fn and can serve as a Fn-mimetic biomaterial.

  16. Matrix theory

    CERN Document Server

    Franklin, Joel N

    2003-01-01

    Mathematically rigorous introduction covers vector and matrix norms, the condition-number of a matrix, positive and irreducible matrices, much more. Only elementary algebra and calculus required. Includes problem-solving exercises. 1968 edition.

  17. The first of a series of high efficiency, high bmep, turbocharged two-stroke cycle diesel engines; the general motors EMD 645FB engine

    Energy Technology Data Exchange (ETDEWEB)

    Kotlin, J.J.; Dunteman, N.R.; Scott, D.I.; Williams, H.A. Jr.

    1983-01-01

    The current Electro-Motive Division 645 Series turbocharged engines are the Model FB and EC. The FB engine combines the highest thermal efficiency with the highest specific output of any EMD engine to date. The FB Series incorporates 16:1 compression ratio with a fire ring piston and an improved turbocharger design. Engine components included in the FB engine provide very high output levels with exceptional reliability. This paper also describes the performance of the lower rated Model EC engine series which feature high thermal efficiency and utilize many engine components well proven in service and basic to the Model FB Series.

  18. Removal of muscle artifact from EEG data: comparison between stochastic (ICA and CCA) and deterministic (EMD and wavelet-based) approaches

    Science.gov (United States)

    Safieddine, Doha; Kachenoura, Amar; Albera, Laurent; Birot, Gwénaël; Karfoul, Ahmad; Pasnicu, Anca; Biraben, Arnaud; Wendling, Fabrice; Senhadji, Lotfi; Merlet, Isabelle

    2012-12-01

    Electroencephalographic (EEG) recordings are often contaminated with muscle artifacts. This disturbing myogenic activity not only strongly affects the visual analysis of EEG, but also most surely impairs the results of EEG signal processing tools such as source localization. This article focuses on the particular context of the contamination epileptic signals (interictal spikes) by muscle artifact, as EEG is a key diagnosis tool for this pathology. In this context, our aim was to compare the ability of two stochastic approaches of blind source separation, namely independent component analysis (ICA) and canonical correlation analysis (CCA), and of two deterministic approaches namely empirical mode decomposition (EMD) and wavelet transform (WT) to remove muscle artifacts from EEG signals. To quantitatively compare the performance of these four algorithms, epileptic spike-like EEG signals were simulated from two different source configurations and artificially contaminated with different levels of real EEG-recorded myogenic activity. The efficiency of CCA, ICA, EMD, and WT to correct the muscular artifact was evaluated both by calculating the normalized mean-squared error between denoised and original signals and by comparing the results of source localization obtained from artifact-free as well as noisy signals, before and after artifact correction. Tests on real data recorded in an epileptic patient are also presented. The results obtained in the context of simulations and real data show that EMD outperformed the three other algorithms for the denoising of data highly contaminated by muscular activity. For less noisy data, and when spikes arose from a single cortical source, the myogenic artifact was best corrected with CCA and ICA. Otherwise when spikes originated from two distinct sources, either EMD or ICA offered the most reliable denoising result for highly noisy data, while WT offered the better denoising result for less noisy data. These results suggest that

  19. 一种基于改进EMD的语音去噪方法%Speech De -Noising Method Based on Improved EMD

    Institute of Scientific and Technical Information of China (English)

    张君昌; 赵莉

    2011-01-01

    Speech signal is corrupted inevitably by noise which results in speech distortion during generation, transmission and reception process. In this paper, Empirical Mode Decomposition (EMD) for non -stationary and nonlinear signal analysis is applied to speech de - noising. Moreover, focusing on the problems of envelopes fitting and interpolation selection in conventional EMD, an improved EMD is proposed, which uses cubic Hermite interpola-tion instead of cubic spline for signal envelopes fitting, and doubly - iterative sifting method instead of local extrema for interpolation points selection. Thus, the errors of algorithm can be reduced, and overshoots or undershoots be a-voided. Simulation shows that the proposed method decreases speech distortion and increases output SNR, compared with speech de - noising based on wavelet and conventional EMD.%语音信号在产生、传输及接收过程中,不可避免会受到噪声干扰从而引起失真.针对传统经验模态分解算法存在的包络线拟合和插值点选择问题,为减少语音失真,提高语音质量,提出了一种改进的经验模态分解算法.采用分段三次埃尔米特插值代替三次样条来计算信号包络,并结合内、外双迭代法代替局部极值来求插值点,从而降低了算法的分解误差,避免了拟合时的过冲欠冲现象.仿真结果表明,与小波变换和传统经验模态分解的语音去噪相比,提出的算法减少了语音的失真,提高了输出信噪比.

  20. EMD-DWT based transform domain feature reduction approach for quantitative multi-class classification of breast lesions.

    Science.gov (United States)

    Ara, Sharmin R; Bashar, Syed Khairul; Alam, Farzana; Hasan, Md Kamrul

    2017-09-01

    Using a large set of ultrasound features does not necessarily ensure improved quantitative classification of breast tumors; rather, it often degrades the performance of a classifier. In this paper, we propose an effective feature reduction approach in the transform domain for improved multi-class classification of breast tumors. Feature transformation methods, such as empirical mode decomposition (EMD) and discrete wavelet transform (DWT), followed by a filter- or wrapper-based subset selection scheme are used to extract a set of non-redundant and more potential transform domain features through decorrelation of an optimally ordered sequence of N ultrasonic bi-modal (i.e., quantitative ultrasound and elastography) features. The proposed transform domain bi-modal reduced feature set with different conventional classifiers will classify 201 breast tumors into benign-malignant as well as BI-RADS⩽3, 4, and 5 categories. For the latter case, an inadmissible error probability is defined for the subset selection using a wrapper/filter. The classifiers use train truth from histopathology/cytology for binary (i.e., benign-malignant) separation of tumors and then bi-modal BI-RADS scores from the radiologists for separating malignant tumors into BI-RADS category 4 and 5. A comparative performance analysis of several widely used conventional classifiers is also presented to assess their efficacy for the proposed transform domain reduced feature set for classification of breast tumors. The results show that our transform domain bimodal reduced feature set achieves improvement of 5.35%, 3.45%, and 3.98%, respectively, in sensitivity, specificity, and accuracy as compared to that of the original domain optimal feature set for benign-malignant classification of breast tumors. In quantitative classification of breast tumors into BI-RADS categories⩽3, 4, and 5, the proposed transform domain reduced feature set attains improvement of 3.49%, 9.07%, and 3.06%, respectively, in

  1. SVD row or column symmetric matrix

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A new architecture for row or column symmetric matrix called extended matrix is defined, and a precise correspondence of the singular values and singular vectors between the extended matrix and its original (namely, the mother matrix) is derived. As an illustration of potential, we show that, for a class of extended matrices, the singular value decomposition using the mother matrix rather than the extended matrix per se can save the CPU time and memory without loss of numerical precision.

  2. Embedding nano-Li{sub 4}Ti{sub 5}O{sub 12} in hierarchical porous carbon matrixes derived from water soluble polymers for ultra-fast lithium ion batteries anodic materials

    Energy Technology Data Exchange (ETDEWEB)

    Lan, Chun-Kai; Bao, Qi; Huang, Yao-Hui; Duh, Jenq-Gong, E-mail: jgd@mx.nthu.edu.tw

    2016-07-15

    Li{sub 4}Ti{sub 5}O{sub 12}/hierarchical porous carbon matrixes composites are successfully prepared by a facile and fast polymers assisted sol–gel method, aiming to promote both electronic and ionic conductivity. As indicated by Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy analysis, three less expensive cost and available water soluble polymers (e.g. PAA, CMC, and SA) can homogeneously react with Li–Ti–O precursor to incorporate into interior of nano-scale lithium titanate and provide a continues conductive network after pyrolysis. In addition, the results of scanning electron microscopy and transmission electron microscopy also prove that the Li{sub 4}Ti{sub 5}O{sub 12} nanoparticles are firmly embedded in porous carbon matrix with no obvious agglomeration. EIS measurement and cyclic voltammetry further reveal that the facilitated electrode kinetics and better ionic transport of Li{sub 4}Ti{sub 5}O{sub 12}/hierarchical porous carbon matrixes composites than that of Li{sub 4}Ti{sub 5}O{sub 12}. The c-CMC-LTO exhibits a superior capacity of 92 mAh g{sup −1} and retains its initial value with no obviously capacity decay over 200 cycles under an ultra-high C rate (50 C). - Graphical abstract: Schematic illustrations of the formation process of embedding LTO into Carbon matrixes derived from water soluable polymers (upper) and the electrochemical reaction paths in LTO/Carbon composites during charging/discharging processes (lower). - Highlights: • Hierarchical porous carbon matrixes were used to improve the Li{sub 4}Ti{sub 5}O{sub 12} anodes. • Carbon matrixes could suppress the agglomeration of Li{sub 4}Ti{sub 5}O{sub 12} nanoparticles. • meso-nanoporous carbon structure was beneficial for filtration of electrolyte. • The c-CMC-LTO exhibited superior high rate capability and cycling durability.

  3. Properties of the matrix A-XY

    NARCIS (Netherlands)

    Steerneman, A.G.M.; van Perlo -ten Kleij, Frederieke

    2005-01-01

    The main topic of this paper is the matrix V = A - XY*, where A is a nonsingular complex k x k matrix and X and Y are k x p complex matrices of full column rank. Because properties of the matrix V can be derived from those of the matrix Q = I - XY*, we will consider in particular the case where A =

  4. EEG Signal Processing Method Based on EMD and SVM%基于EMD和SVM的脑电信号处理方法

    Institute of Scientific and Technical Information of China (English)

    余炜; 韩强; 马晶晶; 谢培

    2012-01-01

    脑电信号的特征提取对于脑—机接口(BCI)技术来说非常重要.本文使用经验模式分解(EMD)算法对脑电信号进行分解,提取主要IMF分量的特征值,之后使用支持向量机进行分类,并采用启发算法(POS)进行参数寻优.对2003年第二届BCI大赛的想象左右手运动脑电信号分类正确率达到87.6%,验证了本方法的可行性.%EEG feature extraction is of vital significance for the brain - computer interface ( BCI) technology. In this paper, empirical mode decomposition (EMD) algorithm is adopted to decompose the EEG and to extract the characteristic values of the major IMF component. Then the SVM is employed for the classification and the heuristic algorithm (POS) is used for parameter optimization. The feasibility of the method is verified by the classification of EEG signal of imagining the right and left hands movement in the second BCI competition in 2003, with an accuracy of 87. 6%.

  5. Mixed lineage kinase 3 inhibits platelet-derived growth factor-stimulated DNA synthesis and matrix mRNA expression in mesangial cells.

    Science.gov (United States)

    Parameswaran, Narayanan; Hall, Carolyn S; Böck, Barbara C; Sparks, Harvey V; Gallo, Kathleen A; Spielman, William S

    2002-01-01

    Mixed lineage kinase 3 (MLK 3) is a recently described member of the MLK subfamily of Ser/Thr protein kinases that interacts with MAPK pathways. The aim of this study was to test the potential interaction of MLK 3 with signaling pathways stimulated by PDGF in rat mesangial cells. We have established a stable cell line expressing human MLK 3 in rat glomerular mesangial cells. The effects of PDGF on proliferation and matrix mRNA expression were examined. In control (vector-transfected) mesangial cells PDGF increased [(3)H]-thymidine incorporation significantly in a concentration-dependent manner. In mesangial cells expressing MLK 3, PDGF-induced increase in DNA synthesis was significantly reduced. PDGF also induced fibronectin and collagen I mRNA expression in control cells, the effects of which were also significantly blocked in MLK 3-transfected cells. To understand the potential interaction of MLK 3 over expression with the MAPK pathways and to examine the potential mechanism of the effects of MLK 3 over expression on proliferation and matrix expression, activation of ERK2, JNK1 and p38 were examined. ERK2 activation was increased several fold by PDGF in control cells but was attenuated significantly in MLK 3 expressing cells. PDGF did not have any effect on JNK and p38 activation, in either cell types. Using the same stable-transfected cell line, identical results were obtained on proliferation and matrix expression with sarafotoxin-s6b (endothelin receptor agonist) another potent mitogenic and sclerotic agent for mesangial cells. These results indicate an important role for MLK 3 in the regulation of growth and matrix expression in mesangial cells.

  6. Matrix theory of gravitation

    CERN Document Server

    Koehler, Wolfgang

    2011-01-01

    A new classical theory of gravitation within the framework of general relativity is presented. It is based on a matrix formulation of four-dimensional Riemann-spaces and uses no artificial fields or adjustable parameters. The geometrical stress-energy tensor is derived from a matrix-trace Lagrangian, which is not equivalent to the curvature scalar R. To enable a direct comparison with the Einstein-theory a tetrad formalism is utilized, which shows similarities to teleparallel gravitation theories, but uses complex tetrads. Matrix theory might solve a 27-year-old, fundamental problem of those theories (sec. 4.1). For the standard test cases (PPN scheme, Schwarzschild-solution) no differences to the Einstein-theory are found. However, the matrix theory exhibits novel, interesting vacuum solutions.

  7. Matrix Factorization and Matrix Concentration

    OpenAIRE

    Mackey, Lester

    2012-01-01

    Motivated by the constrained factorization problems of sparse principal components analysis (PCA) for gene expression modeling, low-rank matrix completion for recommender systems, and robust matrix factorization for video surveillance, this dissertation explores the modeling, methodology, and theory of matrix factorization.We begin by exposing the theoretical and empirical shortcomings of standard deflation techniques for sparse PCA and developing alternative methodology more suitable for def...

  8. "On some definitions in matrix algebra"

    OpenAIRE

    Magnus, Jan R.; Karim M. Abadir

    2007-01-01

    Many definitions in matrix algebra are not standardized. This notediscusses some of thepitfalls associated with undesirable orwrong definitions, anddealswith central conceptslikesymmetry, orthogonality, square root, Hermitian and quadratic forms, and matrix derivatives.

  9. Matrix elements of unstable states

    CERN Document Server

    Bernard, V; Meißner, U -G; Rusetsky, A

    2012-01-01

    Using the language of non-relativistic effective Lagrangians, we formulate a systematic framework for the calculation of resonance matrix elements in lattice QCD. The generalization of the L\\"uscher-Lellouch formula for these matrix elements is derived. We further discuss in detail the procedure of the analytic continuation of the resonance matrix elements into the complex energy plane and investigate the infinite-volume limit.

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

    Science.gov (United States)

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

    2010-03-01

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

  11. Paracrine Effects of Adipose-Derived Stem Cells on Matrix Stiffness-Induced Cardiac Myofibroblast Differentiation via Angiotensin II Type 1 Receptor and Smad7

    Science.gov (United States)

    Yong, Kar Wey; Li, Yuhui; Liu, Fusheng; Bin Gao; Lu, Tian Jian; Wan Abas, Wan Abu Bakar; Wan Safwani, Wan Kamarul Zaman; Pingguan-Murphy, Belinda; Ma, Yufei; Xu, Feng; Huang, Guoyou

    2016-01-01

    Human mesenchymal stem cells (hMSCs) hold great promise in cardiac fibrosis therapy, due to their potential ability of inhibiting cardiac myofibroblast differentiation (a hallmark of cardiac fibrosis). However, the mechanism involved in their effects remains elusive. To explore this, it is necessary to develop an in vitro cardiac fibrosis model that incorporates pore size and native tissue-mimicking matrix stiffness, which may regulate cardiac myofibroblast differentiation. In the present study, collagen coated polyacrylamide hydrogel substrates were fabricated, in which the pore size was adjusted without altering the matrix stiffness. Stiffness is shown to regulate cardiac myofibroblast differentiation independently of pore size. Substrate at a stiffness of 30 kPa, which mimics the stiffness of native fibrotic cardiac tissue, was found to induce cardiac myofibroblast differentiation to create in vitro cardiac fibrosis model. Conditioned medium of hMSCs was applied to the model to determine its role and inhibitory mechanism on cardiac myofibroblast differentiation. It was found that hMSCs secrete hepatocyte growth factor (HGF) to inhibit cardiac myofibroblast differentiation via downregulation of angiotensin II type 1 receptor (AT1R) and upregulation of Smad7. These findings would aid in establishment of the therapeutic use of hMSCs in cardiac fibrosis therapy in future. PMID:27703175

  12. Active noise control system based on EMD and loudness%基于EMD与响度的有源噪声控制系统

    Institute of Scientific and Technical Information of China (English)

    聂永红; 程军圣; 张亢; 陈建国

    2012-01-01

    In order to improve the noise reduction effect of the control system, an active noise control system based on EMD(empirical mode decomposition) and loudness is proposed. The noise source is decomposed adaptively using EMD at first and the loudness of all IMFs is calculated in such a system. Then a shaping filter of the error signal is designed according to the amplitudes of the IMF loudness. The filter designed with this method can restrain the components of noise source with small loudness better than A-weighting shaping filter. The noise reduction effect of the active noise control system is simulated. The results show that the control system proposed in this paper can improve the noise reduction effect compared with the system based on filtered-X LMS (filtered-X least mean square) and A-weighting shaping filter.%为了提高有源噪声控制系统的降噪效果,提出了基于经验模态分解( empirical mode decomposition,EMD)和响度的控制系统.该系统首先采用EMD方法对噪声源进行自适应分解,并对分解后的各个固有模态函数(intrinsic mode function,IMF)分量的响度进行计算,然后根据各个分量的响度大小进行残差滤波器的设计.与基于A计权曲线设计的残差滤波器相比,该方法所设计滤波器能更好地抑制响度较小的信号频率成分.对有源噪声控制系统的降噪效果进行了仿真,结果表明,所提出的控制系统比传统滤波-X LMS(filtered-X least mean square)方法和采用基于A计权残差滤波器的系统降噪效果更好.

  13. Matrix calculus

    CERN Document Server

    Bodewig, E

    1959-01-01

    Matrix Calculus, Second Revised and Enlarged Edition focuses on systematic calculation with the building blocks of a matrix and rows and columns, shunning the use of individual elements. The publication first offers information on vectors, matrices, further applications, measures of the magnitude of a matrix, and forms. The text then examines eigenvalues and exact solutions, including the characteristic equation, eigenrows, extremum properties of the eigenvalues, bounds for the eigenvalues, elementary divisors, and bounds for the determinant. The text ponders on approximate solutions, as well

  14. Design of decentralized proportional–integral–derivative controller based on decoupler matrix for two-input/two-output process with active disturbance rejection structure

    Directory of Open Access Journals (Sweden)

    Qibing Jin

    2016-06-01

    Full Text Available The framework of the active disturbance rejection internal model control is proposed to solve the problem of the model reduced-order error in the process of the controller design for two-input/two-output system with time delay. In the controller design process of the two-input/two-output system, the decoupler matrix method is used to decompose a multi-loop control system into a set of equivalent independent single loops. Then, a complex equivalent model is obtained, and its order should be reduced for each individual loop. Maclaurin series method is used to reduce the order of the decoupling model. After reducing model order, the proposed method is applied to lessen the effect of the reduced-order error and improve the anti-interference ability and robustness for the control system. Simulation results show that the proposed method possesses a good disturbance rejection performance.

  15. Large molecular mass materials in coal derived liquids by {sup 252}Cf-plasma and matrix assisted laser desorption mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Domin, M. [School of Pharmacy, London (United Kingdom). Dept. of Pharmaceutical and Biological Chemistry; Li, S.; Herod, A.A.; Larsen, J.W. [Lehigh Univ., Bethlehem, PA (United States). Dept. of Chemistry; Lazaro, M.J.; Kandiyoti, R. [Imperial College, London (United Kingdom). Dept. of Chemical Engineering and Chemical Technology

    1997-12-31

    A Point of Ayr coal extract, its hydrocracked product and the pyridine solubles/insolubles of a coal tar pitch have been examined using {sup 252}Cf-plasma desorption-mass spectrometry (PDMS) and matrix assisted laser desorption-mass spectrometry (MALDI-MS). Comparison of molecular masses (MMs) between the coal extract and its hydrocracked product by PDMS indicated ranges of masses in the product to be considerably smaller, with number and weight average MMs reduced by approximately a factor of two. MALDI-mass spectra of the same samples indicated a greater reduction in mass. Similar comparison of the pyridine soluble/insoluble fractions of the coal tar pitch showed smaller differences by PD-MS than by MALDI-MS. (orig.)

  16. Uso de proteínas derivadas de la matriz del esmalte en defectos infraóseos periodontales: Presentación de casos clínicos Use of proteins enamel matrix derivative in infrabony periodontal defects: Presentación de casos clínicos

    OpenAIRE

    Alonso A.; L Aracil; Blanco, J; D Rodrigo; A. Bascones

    2006-01-01

    La periodontitis es una infección crónica causada por las bacterias de la placa dental. Esta condición induce la perdida de soporte del aparato de inserción. La cirugía está indicada para detener la progresión de la enfermedad y regenerar el tejido perdido. Se han utilizado diferentes técnicas quirúrgicas para regenerar los tejidos periodontales incluyendo la regeneración tisular guiada (RTG), y el uso de proteínas derivadas de la matriz del esmalte (EMD). Las EMD contienen amelogenina. Se sa...

  17. Uso de proteínas derivadas de la matriz del esmalte en defectos infraóseos periodontales: Presentación de casos clínicos Use of proteins enamel matrix derivative in infrabony periodontal defects: Presentación de casos clínicos

    OpenAIRE

    Alonso A; L Aracil; Blanco, J; Rodrigo, D.; A Bascones

    2006-01-01

    La periodontitis es una infección crónica causada por las bacterias de la placa dental. Esta condición induce la perdida de soporte del aparato de inserción. La cirugía está indicada para detener la progresión de la enfermedad y regenerar el tejido perdido. Se han utilizado diferentes técnicas quirúrgicas para regenerar los tejidos periodontales incluyendo la regeneración tisular guiada (RTG), y el uso de proteínas derivadas de la matriz del esmalte (EMD). Las EMD contienen amelogenina. Se sa...

  18. The comparative effectiveness of demineralized bone matrix, beta-tricalcium phosphate, and bovine-derived anorganic bone matrix on inflammation and bone formation using a paired calvarial defect model in rats

    Directory of Open Access Journals (Sweden)

    Khoshzaban A

    2011-09-01

    Full Text Available Ahad Khoshzaban1,2,3, Shahram Mehrzad1, Vida Tavakoli2, Saeed Heidari Keshel2, Gholam Reza Behrouzi2, Maryam Bashtar2 1Iranian Tissue Bank Research and Preparation Center, Imam Khomeini Hospital Complex, 2Stem Cells Preparation Unit, Eye Research Center, Farabi Hospital, Tehran University of Medical Science, 3Dental Bio Material Department, Tehran University of Medical Science, Faculty of Dentistry, Tehran, Iran Background: In this study, the effectiveness of Iranian Tissue Bank–produced demineralized bone matrix (ITB-DBM, beta-tricalcium phosphate (ßTCP, and Bio-Oss® (Geistlich Pharma AG, Wolhusen, Switzerland were evaluated and compared with double controls. The main goal was to measure the amount of new bone formation in the center of defects created in rat calvaria. Another goal was to compare the controls and evaluate the effects of each treatment material on their adjacent untreated (control defects. Methods: In this study, 40 male Wistar rats were selected and divided into four groups, In each group, there were ten rats with two defects in their calvarias; one of them is considered as control and the other one was treated with ITB-DBM (group 1, BIO-OSS (group2, and ßTCP (group 3, respectively. But in group 4, both defects were considered as control. The amount of inflammation and new bone formation were evaluated at 4 and 10 weeks. In the first group, one defect was filled with ITB-DBM; in the second group, one defect was filled with Bio-Oss; in the third group, one defect was filled with ßTCP; and in the fourth group, both defects were left unfilled. Zeiss microscope (Carl Zeiss AG, Oberkochen, Germany and Image Tool® (version 3.0; University of Texas Health Science Center at San Antonio, San Antonio, TX software were used for evaluation. SPSS Statistics (IBM Corp, Somers, NY was used for statistical analysis. Results: Maximum bone formation at 4 and 10 weeks were observed in the ITB-DBM group (46.960% ± 4.366%, 94.970% ± 0

  19. A heteroskedastic error covariance matrix estimator using a first-order conditional autoregressive Markov simulation for deriving asympotical efficient estimates from ecological sampled Anopheles arabiensis aquatic habitat covariates

    Directory of Open Access Journals (Sweden)

    Githure John I

    2009-09-01

    Full Text Available Abstract Background Autoregressive regression coefficients for Anopheles arabiensis aquatic habitat models are usually assessed using global error techniques and are reported as error covariance matrices. A global statistic, however, will summarize error estimates from multiple habitat locations. This makes it difficult to identify where there are clusters of An. arabiensis aquatic habitats of acceptable prediction. It is therefore useful to conduct some form of spatial error analysis to detect clusters of An. arabiensis aquatic habitats based on uncertainty residuals from individual sampled habitats. In this research, a method of error estimation for spatial simulation models was demonstrated using autocorrelation indices and eigenfunction spatial filters to distinguish among the effects of parameter uncertainty on a stochastic simulation of ecological sampled Anopheles aquatic habitat covariates. A test for diagnostic checking error residuals in an An. arabiensis aquatic habitat model may enable intervention efforts targeting productive habitats clusters, based on larval/pupal productivity, by using the asymptotic distribution of parameter estimates from a residual autocovariance matrix. The models considered in this research extends a normal regression analysis previously considered in the literature. Methods Field and remote-sampled data were collected during July 2006 to December 2007 in Karima rice-village complex in Mwea, Kenya. SAS 9.1.4® was used to explore univariate statistics, correlations, distributions, and to generate global autocorrelation statistics from the ecological sampled datasets. A local autocorrelation index was also generated using spatial covariance parameters (i.e., Moran's Indices in a SAS/GIS® database. The Moran's statistic was decomposed into orthogonal and uncorrelated synthetic map pattern components using a Poisson model with a gamma-distributed mean (i.e. negative binomial regression. The eigenfunction

  20. Deriving Accurate Interproton Distances from ROESY Spectra with Limited Knowledge of Scalar Coupling Constants via the CARNIVAL Algorithm. An Iterative Complete-Relaxation-Matrix Approach

    Science.gov (United States)

    Liu, H.; Banville, D. L.; Basus, V. J.; James, T. L.

    A method (termed CARNIVAL) for accurately determining distances from proton homonuclear rotating-frame Overhauser effect spectroscopy (ROESY) is described. The method entails an iterative calculation of the relaxation matrix using methodology introduced with the MARDIGRAS algorithm for analysis of two-dimensional nuclear Overhauser effect spectra (B. A. Borgias and T. L. James, J. Magn. Reson.87, 475, 1990). The situation is complicated in the case of ROESY as spectral peak intensities are influenced by resonance offset and contributions from homonuclear Hartmann-Hahn (HOHAHA) transfer if the nuclear spins are related by scalar coupling. The effects of spin-locking field strength on distance determinations and the ensuing distance errors incurred when HOHAHA corrections are made with limited knowledge of scalar ( J) coupling information have been evaluated using simulated ROESY intensities with a model peptide structure. It has been demonstrated that accurate distances can be obtained with little or no explicit knowledge of the homonuclear coupling constants over a moderate range of spin-locking field strengths. The CARNIVAL algorithm has been utilized to determine distances in a decapeptide using experimental ROESY data without measured coupling constants.

  1. Emdogain in regenerative periodontal therapy. A review of the literature.

    Science.gov (United States)

    Sculean, Anton; Windisch, Péter; Döri, Ferenc; Keglevich, Tibor; Molnár, Balint; Gera, István

    2007-10-01

    The goal of regenerative periodontal therapy is the reconstitution of the lost periodontal structures (i.e. the new formation of root cementum, periodontal ligament and alveolar bone). Results from basic research have pointed to the important role of the enamel matrix protein derivative (EMD) in the periodontal wound healing. Histological results from animal and human studies have shown that treatment with EMD promotes periodontal regeneration. Moreover, clinical studies have indicated that treatment with EMD positively influences periodontal wound healing in humans. The goal of the current overview is to present, based on the existing evidence, the clinical indications for regenerative therapy with EMD. Surgical periodontal treatment of deep intrabony defects with EMD promotes periodontal regeneration. The application of EMD in the context of non-surgical periodontal therapy has failed to result in periodontal regeneration. Surgical periodontal therapy of deep intrabony defects with EMD may lead to significantly higher improvements of the clinical parameters than open flap debridement alone. The results obtained following treatment with EMD are comparable to those following treatment with GTR and can be maintained over a longer period. Treatment of intrabony defects with a combination of EMD + GTR does not seem to additionally improve the results compared to treatment with EMD alone or GTR alone. The combination of EMD and some types of bone grafts/bone substitutes may result in certain improvements in the soft and hard tissue parameters compared to treatment with EMD alone. Treatment of recession-type defects with coronally repositioned flaps and EMD may promote formation of cementum, periodontal ligament and bone, and may significantly increase the width of the keratinized tissue. Application of EMD seems to provide better long-term results than coronally repositioned flaps alone. Application of EMD may enhance periodontal regeneration in mandibular Class II

  2. COAL DERIVED MATRIX PITCHES FOR CARBON-CARBON COMPOSITE MANUFACTURE/PRODUCTION OF FIBERS AND COMPOSITES FROM COAL-BASED PRECURSORS

    Energy Technology Data Exchange (ETDEWEB)

    Peter G. Stansberry; John W. Zondlo

    2001-07-01

    The Consortium for premium Carbon Products from Coal, with funding from the US Department of Energy, National Energy Technology Laboratory continue with the development of innovative technologies that will allow coal or coal-derived feedstocks to be used in the production of value-added carbon materials. In addition to supporting eleven independent projects during budget period 3, three meetings were held at two separate locations for the membership. The first was held at Nemacolin Woodlands Resort on May 15-16, 2000. This was followed by two meetings at Penn State, a tutorial on August 11, 2000 and a technical progress meeting on October 26-27.

  3. Refractory damage pattern recognition based on EDM and multi-fractal spectrum parameters%基于 EMD 和多重分形谱参数的耐火材料损伤模式识别

    Institute of Scientific and Technical Information of China (English)

    苏涛; 王志刚; 刘昌明; 徐增丙; 但斌斌

    2015-01-01

    考虑到耐火材料损伤声发射信号模式识别困难,提出一种结合经验模态分解(EM D )、多重分形谱参数和支持向量机的耐火材料损伤形式分类方法。首先对耐火材料损伤声发射信号进行ED M 分解得到若干本征模态函数(IM F )分量,并取前4个分量作为研究对象,然后将整个信号的多重分形谱宽及各IM F分量的多重分形谱宽组成的特征向量输入支持向量机进行学习训练,最后实现耐火材料损伤模式识别。研究结果表明,采用由原信号及各IM F分量的多重分形谱宽值组成的特征向量能够有效进行损伤信号的特征提取。该方法对耐火材料界面相损伤的分类准确率为99%,对其基质相损伤的分类准确率为89%。%Considering the difficulty of pattern recognition of the acoustic emission signals of refractory damage ,this paper proposes a classification method for refractory damage pattern based on empirical mode decomposition (EMD) ,multi‐fractal spectrum parameters and support vector machine .First , the acoustic emission signals are decomposed into several intrinsic mode function (IM F) components by EDM ,and the first four components are taken as the research objects .Second ,a feature vector formed by multi‐fractal spectrum width values of the entire signal and IMF components is used in learning and training of support vector machine (SVM ) .Then the refractory damage pattern classifi‐cation is completed by SVM .The results show that the constructed feature vector is efficient in fea‐ture extraction of damage signals .The classification accuracy of this method for interface damage and matrix damage of refractory can reach up to 99% and 89% ,respectively .

  4. Large molecular mass materials in coal-derived liquids by {sup 252}Cf-plasma and matrix-assisted laser desorption mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Domin, M.; Li, S.; Lazaro, M.-J.; Herod, A.A.; Larsen, J.W.; Kandiyoti, R. [School of Pharmacy, London (United Kingdom). Dept. of Parmaceutical and Biological Chemistry

    1998-05-01

    The paper compares responses of {sup 252}Cf-plasma desorption MS (PD-MS) and matrix-assisted laser desorption (MALDI) MS to identical samples. The two pairs of samples selected for the comparison were known from previous work to differ significantly in their high mass contents. MALDI-MS showed large differences in MM distributions within both pairs of samples. The PD-MS data showed a degree of similarity between one pair of samples (pyridine soluble/insoluble fractions of a coal tar pitch); for the second pair (a coal extract and its hydrocracked product), trends from the two MS techniques agreed closely. The MM range observed by PD-MS was somewhat narrower, extending to between 3000 and 5000 u. Significant differences within pairs of samples were observed by SEC and by UV-fluorescence spectroscopy, providing somewhat closer agreement with the MALDI spectra. The two MS instruments differ in two important respects: the ionization system (i.e., plasma vs laser desorption) and the maximum available ion extraction voltage: 30 kV for the MALDI-MS instrument and 15 kV for the PD-MS. The comparison of plasma vs laser desorption mass spectroscopy could not therefore take place at high ion extraction voltages. Work at up to 30 kV in the MALDI instrument indicated better sensitivity to high-mass materials at higher ion extraction voltages. The qualitative similarity of results from the two MS techniques is nevertheless apparent; the range of MMs observed in PD-MS as well as in MALDI-MS were, furthermore, far larger than those reported by any MS technique, to date. 38 refs., 6 figs., 1 tab.

  5. Spherical membranes in Matrix theory

    CERN Document Server

    Kabat, D; Kabat, Daniel; Taylor, Washington

    1998-01-01

    We consider membranes of spherical topology in uncompactified Matrix theory. In general for large membranes Matrix theory reproduces the classical membrane dynamics up to 1/N corrections; for certain simple membrane configurations, the equations of motion agree exactly at finite N. We derive a general formula for the one-loop Matrix potential between two finite-sized objects at large separations. Applied to a graviton interacting with a round spherical membrane, we show that the Matrix potential agrees with the naive supergravity potential for large N, but differs at subleading orders in N. The result is quite general: we prove a pair of theorems showing that for large N, after removing the effects of gravitational radiation, the one-loop potential between classical Matrix configurations agrees with the long-distance potential expected from supergravity. As a spherical membrane shrinks, it eventually becomes a black hole. This provides a natural framework to study Schwarzschild black holes in Matrix theory.

  6. Matrix Thermalization

    CERN Document Server

    Craps, Ben; Nguyen, Kévin

    2016-01-01

    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.

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

    Science.gov (United States)

    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. PMID:25949808

  8. Experimental and computational investigation of the effect of hydrophobicity on aggregation and osteoinductive potential of BMP-2-derived peptide in a hydrogel matrix.

    Science.gov (United States)

    Moeinzadeh, Seyedsina; Barati, Danial; Sarvestani, Samaneh K; Karimi, Tahereh; Jabbari, Esmaiel

    2015-01-01

    An attractive approach to reduce the undesired side effects of bone morphogenetic proteins (BMPs) in regenerative medicine is to use osteoinductive peptide sequences derived from BMPs. Although the structure and function of BMPs have been studied extensively, there is limited data on structure and activity of BMP-derived peptides immobilized in hydrogels. The objective of this work was to investigate the effect of concentration and hydrophobicity of the BMP-2 peptide, corresponding to residues 73-92 of the knuckle epitope of BMP-2 protein, on peptide aggregation and osteogenic differentiation of human mesenchymal stem cells encapsulated in a polyethylene glycol (PEG) hydrogel. The peptide hydrophobicity was varied by capping PEG chain ends with short lactide segments. The BMP-2 peptide with a positive index of hydrophobicity had a critical micelle concentration (CMC) and formed aggregates in aqueous solution. Based on simulation results, there was a slight increase in the concentration of free peptide in solution with 1000-fold increase in peptide concentration. The dose-osteogenic response curve of the BMP-2 peptide was in the 0.0005-0.005 mM range, and osteoinductive potential of the BMP-2 peptide was significantly less than that of BMP-2 protein even at 1000-fold higher concentrations, which was attributed to peptide aggregation. Further, the peptide or PEG-peptide aggregates had significantly higher interaction energy with the cell membrane compared with the free peptide, which led to a higher nonspecific interaction with the cell membrane and loss of osteoinductive potential. Conjugation of the BMP-2 peptide to PEG increased CMC and osteoinductive potential of the peptide whereas conjugation to lactide-capped PEG reduced CMC and osteoinductive potential of the peptide. Experimental and simulation results revealed that osteoinductive potential of the BMP-2 peptide is correlated with its CMC and the free peptide concentration in aqueous medium and not the

  9. Random matrix theory

    CERN Document Server

    Deift, Percy

    2009-01-01

    This book features a unified derivation of the mathematical theory of the three classical types of invariant random matrix ensembles-orthogonal, unitary, and symplectic. The authors follow the approach of Tracy and Widom, but the exposition here contains a substantial amount of additional material, in particular, facts from functional analysis and the theory of Pfaffians. The main result in the book is a proof of universality for orthogonal and symplectic ensembles corresponding to generalized Gaussian type weights following the authors' prior work. New, quantitative error estimates are derive

  10. Riemann--Hilbert problems, matrix orthogonal polynomials and discrete matrix equations with singularity confinement

    CERN Document Server

    Cassatella-Contra, Giovanni A

    2011-01-01

    In this paper matrix orthogonal polynomials in the real line are described in terms of a Riemann--Hilbert problem. This approach provides an easy derivation of discrete equations for the corresponding matrix recursion coefficients. The discrete equation is explicitly derived in the matrix Freud case, associated with matrix quartic potentials. It is shown that, when the initial condition and the measure are simultaneously triangularizable, this matrix discrete equation possesses the singularity confinement property, independently if the solution under consideration is given by recursion coefficients to quartic Freud matrix orthogonal polynomials or not.

  11. A matrix clustering method to explore patterns of land-cover transitions in satellite-derived maps of the Brazilian Amazon

    Science.gov (United States)

    Müller-Hansen, Finn; Cardoso, Manoel F.; Dalla-Nora, Eloi L.; Donges, Jonathan F.; Heitzig, Jobst; Kurths, Jürgen; Thonicke, Kirsten

    2017-02-01

    Changes in land-use systems in tropical regions, including deforestation, are a key challenge for global sustainability because of their huge impacts on green-house gas emissions, local climate and biodiversity. However, the dynamics of land-use and land-cover change in regions of frontier expansion such as the Brazilian Amazon are not yet well understood because of the complex interplay of ecological and socioeconomic drivers. In this paper, we combine Markov chain analysis and complex network methods to identify regimes of land-cover dynamics from land-cover maps (TerraClass) derived from high-resolution (30 m) satellite imagery. We estimate regional transition probabilities between different land-cover types and use clustering analysis and community detection algorithms on similarity networks to explore patterns of dominant land-cover transitions. We find that land-cover transition probabilities in the Brazilian Amazon are heterogeneous in space, and adjacent subregions tend to be assigned to the same clusters. When focusing on transitions from single land-cover types, we uncover patterns that reflect major regional differences in land-cover dynamics. Our method is able to summarize regional patterns and thus complements studies performed at the local scale.

  12. Matrix inequalities

    CERN Document Server

    Zhan, Xingzhi

    2002-01-01

    The main purpose of this monograph is to report on recent developments in the field of matrix inequalities, with emphasis on useful techniques and ingenious ideas. Among other results this book contains the affirmative solutions of eight conjectures. Many theorems unify or sharpen previous inequalities. The author's aim is to streamline the ideas in the literature. The book can be read by research workers, graduate students and advanced undergraduates.

  13. Evaluation of an extracellular matrix-derived acellular biphasic scaffold/cell construct in the repair of a large articular high-load-bearing osteochondral defect in a canine model

    Institute of Scientific and Technical Information of China (English)

    YANG Qiang; MA Xin-long; HU Yong-cheng; XU Bao-shan; PENG Jiang; LU Shi-bi; GUO Quan-yi; ZHAO Bin; ZHANG Li; WANG Ai-yuan; XU Weng-jing; XIA Qun

    2011-01-01

    Background Osteochondral lesion repair is a challenging area of orthopedic surgery.Here we aimed to develop an extraceliular matrix-derived,integrated,biphasic scaffold and to investigate the regeneration potential of the scaffold loaded with chondrogenically-induced bone marrow-derived mesenchymal stem cells (BMSCs) in the repair of a large,high-load-bearing,osteochondral defect in a canine model.Methods The biphasic scaffolds were fabricated by combining a decellularization procedure with a freeze-drying technique and characterized by scanning electron microscopy (SEM) and micro-computed tomography (micro-CT).Osteochondral constructs were fabricated in vitro using chondrogenically-induced BMSCs and a biphasic scaffold,then assessed by SEM for cell attachment.Osteochondral defects (4.2 mm (diameter) x 6 mm (depth)) were created in canine femoral condyles and treated with a construct of the biphasic scaffold/chondrogenically-induced BMSCs or with a cell-free scaffold (control group).The repaired defects were evaluated for gross morphology and by histological,biochemical,biomechanical and micro-CT analyses at 3 and 6 months post-implantation.Results The osteochondral defects of the experimental group showed better repair than those of the control group.Statistical analysis demonstrated that the macroscopic and histologic grading scores of the experimental group were always higher than those of the control group,and that the scores for the experimental group at 6 months were significantly higher than those at 3 months.The cartilage stiffness in the experimental group (6 months) was (6.95±0.79)N/mm,70.77% of normal cartilage; osteochondral bone stiffness in the experimental group was (158.16±94.30) N/mm,74.95% of normal tissue; glycosaminoglycan content of tissue-engineered neocartilage was (218±21.6) μg/mg (dry weight),84.82% of native cartilage.Micro-CT analysis of the subchondral bone showed mature trabecular bone regularly formed at 3 and 6 months

  14. [The use of Emdogain in periodontal and osseous regeneration].

    Science.gov (United States)

    Sculean, Anton; Rathe, Florian; Junker, Rüdiger; Becker, Jürgen; Schwarz, Frank; Arweiler, Nicole

    2007-01-01

    The goal of regenerative periodontal therapy is the reconstitution of the lost periodontal structures (i. e. the new formation of root cementum, periodontal ligament and alveolar bone). Results from basic research have pointed to the important role of an enamel matrix protein derivative (EMD) in periodontal wound healing. Histological results from experiments in animals and from human case reports have shown that treatment with EMD promotes periodontal regeneration. Moreover, clinical studies have indicated that treatment with EMD positively influences periodontal wound healing in humans. The goal of the current overview is to present the clinical indications for regenerative therapy with EMD based on the existing evidence.

  15. EMD样本熵在滚动轴承信号复杂性度量中的应用%Application of EMD sample entropy in rolling bearing signal complexity measure

    Institute of Scientific and Technical Information of China (English)

    王季; 楼军伟; 李贵子; 朱琳

    2014-01-01

    针对常用的傅里叶变换、小波变换等在分析滚动轴承信号时存在难以度量复杂性的局限,采用经验模态分解(EMD)结合样本熵来改进。通过对不同故障程度的滚动轴承信号应用样本熵和EMD样本熵的实际效果进行比较,同时对EMD样本熵大的分量进行包络谱分析。结果发现:样本熵值过于接近不易区分,而EMD样本熵值差别明显准确性更高,并且其变化趋势与信号随故障变化的趋势一致,包络谱中存在故障频率及其倍频。该方法可用于轴承运行状态监测和预判。%Aiming at commonly used Fourier Transform, Wavelet Transform etc were difficult to measure the complexity in analysising the rolling bearing signal,using EMD combined with sample entropy to improve.By comparing the actual effect of sample entropy and EMD sample entropy used in different fault levels of rolling bearing singal and analyzing the large EMD sample entropy component,by using time envelope spectrum at the same time,the authors found that the sample entropy values were too close to distinguish, but the EMD sample entropy values were obviously different with higher exact, and the changing trend consistented with the signal changing trend, beside fault frequency and it’s frequency doubling existed in the envelope spectrum. This method can be used to monitore and anticipate bearing condition.

  16. 基于EMD的网络舆情演化分析与建模方法%Evolution Analysis and Modeling Method of Internet Public Opinions Based on EMD

    Institute of Scientific and Technical Information of China (English)

    周耀明; 王波; 张慧成

    2012-01-01

    The existing methods ignore multicomponent characteristics of evolution process of Internet public opinions, which leads to an unsatisfactory performance of analysis and modeling. To deal with the problem, this paper presents an evolution analysis and modeling method of Internet public opinions based on Empirical Mode Decomposition(EMD). It decomposes the evolution process of Internet public opinions by EMD, to form trend component, period component, mutation component and random component. Then it analyzes and models the evolution process of Internet public op.nions by analyzing and modeling the above-mentioned components. Experiments show that the components decomposed by EMD have clear physical meanings, which can help to analyze the evolution patterns of Internet public opinions; at the same time, the method has good forecasting performance, thus is more suitable.%现有研究忽略网络舆情演化过程的多成分特性,导致演化分析与建模效果较差.为此,提出一种基于经验模态分解(EMD)的网络舆情演化分析与建模方法.对演化过程进行EMD分解,形成演化过程的趋势成分、周期成分、突发成分和随机成分,通过对各成分进行分析与建模,实现网络舆情的演化分析与建模.实验结果表明,该方法通过EMD分解得到的各成分物理含义明显,有助于分析网络舆情的演化规律,同时具有较好的趋势预测效果,适合进行演化建模.

  17. 基于LMD EMD故障诊断分析及其研究%Fault diagnosis analysis and research based on LMD EMD

    Institute of Scientific and Technical Information of China (English)

    张辛林; 焦卫东

    2012-01-01

    经验模态分解(EMD)及局域均值分解(LMD)都是转子故障诊断领域时频分析的有效方法.EMD为非平稳信号进行有意义的Hilbert变换起到了桥梁的作用,但是却会因此而产生了不能解释的负频率.而LMD将一个复杂的多分量信号分解为若干个瞬时频率有物理意义的乘积函数(Production Function PF),并且其局部均值函数与包络估计函数都是采用平滑处理的方法形成的避免了EMD方法中的过包络与欠包络现象.实验通过采用LMD与EMD方法对两类常见的转子故障信号的分析比对,得出LMD在高频和频率变化波动大的故障信号中比EMD效果更佳明显.

  18. The Power Quality Disturbance Detection and Classification Method Based on EMD%基于EMD的电能质量扰动检测与分类方法

    Institute of Scientific and Technical Information of China (English)

    武荣华; 王天施; 侯宝明

    2013-01-01

    In view of the signal detection and classification of power quality disturbance problem,the power quality disturbances detection and classification methods based on EMD were proposed,and the common several kinds of disturbance signal were simulated.The time of disturbance occurrence and duration,the frequency and amplitude of disturbance can be detected accurately by this method.Such as voltage sags,voltage swells,voltage interruptions and other disturbances raised the signal amplitude and frequency changes can be estimated.The results of MATLAB simulation show that the proposed method is simple and effective.%针对电能质量扰动信号的检测和分类问题,提出了一种基于EMD的电能质量扰动检测与分类方法,并对常见的几种扰动信号进行仿真.应用该方法检测扰动发生时间、持续时间以及扰动的频率与幅值.仿真结果表明,所提算法简洁有效,能够准确分析电能质量扰动信号,可以估计电压凹陷、电压凸起以及电压中断等扰动信号的变化幅度和频率.

  19. On Exchange Rate Forecasting Method Based on EMD and NARX Neural Network%基于EMD与NARX网络的汇率预测方法研究

    Institute of Scientific and Technical Information of China (English)

    马超; 徐瑾辉; 蓝斌; 侯天诚; 欧阳泽拯

    2015-01-01

    探索构建对汇率进行直接预测的高精度组合预测算法.采用NARX神经网络作为基础模型,并结合经验模态分解模型进行混合预测,提高模型精度.为研究不同时间间隔对预测结果的影响,采用美元兑日元汇率的时间间隔为5分钟与1天的数据进行预测.实验结果显示,时间间隔较短时,模型的预测精度更高.此外,通过对汇率改革前后的人民币汇率的预测发现,汇率改革对EMD-NARX模型的预测结果影响不大,说明模型稳定性较高.

  20. Epileptic Seizure Detection based on Wavelet Transform Statistics Map and EMD Method for Hilbert-Huang Spectral Analyzing in Gamma Frequency Band of EEG Signals

    Directory of Open Access Journals (Sweden)

    Morteza Behnam

    2015-08-01

    Full Text Available Seizure detection using brain signal (EEG analysis is the important clinical methods in drug therapy and the decisions before brain surgery. In this paper, after signal conditioning using suitable filtering, the Gamma frequency band has been extracted and the other brain rhythms, ambient noises and the other bio-signal are canceled. Then, the wavelet transform of brain signal and the map of wavelet transform in multi levels are computed. By dividing the color map to different epochs, the histogram of each sub-image is obtained and the statistics of it based on statistical momentums and Negentropy values are calculated. Statistical feature vector using Principle Component Analysis (PCA is reduced to one dimension. By EMD algorithm and sifting procedure for analyzing the data by Intrinsic Mode Function (IMF and computing the residues of brain signal using spectrum of Hilbert transform and Hilbert – Huang spectrum forming, one spatial feature based on the Euclidian distance for signal classification is obtained. By K-Nearest Neighbor (KNN classifier and by considering the optimal neighbor parameter, EEG signals are classified in two classes, seizure and non-seizure signal, with the rate of accuracy 76.54% and with variance of error 0.3685 in the different tests.

  1. Acupuncture combined with curcumin disrupts platelet-derived growth factor β receptor/extracellular signal-regulated kinase signalling and stimulates extracellular matrix degradation in carbon tetrachloride-induced hepatic fibrosis in rats.

    Science.gov (United States)

    Zhang, Xiao-Ping; Zhang, Feng; Zhang, Zi-Li; Ma, Jin; Kong, De-Song; Ni, Guang-Xia; Wang, Ai-Yun; Chen, Wen-Xing; Lu, Yin; Zheng, Shi-Zhong

    2012-12-01

    Acupuncture treatment has been increasingly used to treat chronic liver diseases. We previously reported that acupuncture combined with curcumin, a natural antifibrotic compound, could remarkably attenuate liver fibrosis in chemically intoxicated rats, but the underlying molecular mechanisms are poorly understood. The present study was aimed at investigating the effects of acupuncture combined with curcumin on platelet-derived growth factor (PDGF) signalling and extracellular matrix (ECM) regulation in the fibrotic liver. A total of 60 Sprague-Dawley male rats were randomly divided into control, model, sham, acupuncture, curcumin and combination treatment groups. During the establishment of fibrosis using carbon tetrachloride (CCl(4)), acupuncture at LR3, LR14, BL18 and ST36 and/or curcumin treatment by mouth were performed simultaneously. After treatment, serum PDGF levels were measured. Protein and mRNA expression of key effectors in PDGF pathway and fibrinolysis in the liver was determined. Acupuncture combined with curcumin potently reduced serum PDGF levels and selectively disrupted the PDGF-βR/extracellular signal-regulated kinase (ERK) cascade. Combination treatment also significantly repressed expression of connective tissue growth factor and upregulated expression of matrix metalloproteinase-9, promoting fibrinolysis in the fibrotic liver. The beneficial effects of acupuncture and its combination with curcumin could be attributed to the disruption of PDGF-βR/ERK pathway and stimulated ECM degradation in the fibrotic liver. Acupuncture treatment significantly enhanced curcumin effects at the molecular level. These findings may provide molecular insights into the potential of acupuncture combined with curcumin for prevention of hepatic fibrosis.

  2. Matrix pentagons

    CERN Document Server

    Belitsky, A V

    2016-01-01

    The Operator Product Expansion for null polygonal Wilson loop in planar maximally supersymmetric Yang-Mills theory runs systematically in terms of multiparticle pentagon transitions which encode the physics of excitations propagating on the color flux tube ending on the sides of the four-dimensional contour. Their dynamics was unravelled in the past several years and culminated in a complete description of pentagons as an exact function of the 't Hooft coupling. In this paper we provide a solution for the last building block in this program, the SU(4) matrix structure arising from internal symmetry indices of scalars and fermions. This is achieved by a recursive solution of the Mirror and Watson equations obeyed by the so-called singlet pentagons and fixing the form of the twisted component in their tensor decomposition. The non-singlet, or charged, pentagons are deduced from these by a limiting procedure.

  3. Singular Value Decomposition for Unitary Symmetric Matrix

    Institute of Scientific and Technical Information of China (English)

    ZOUHongxing; WANGDianjun; DAIQionghai; LIYanda

    2003-01-01

    A special architecture called unitary sym-metric matrix which embodies orthogonal, Givens, House-holder, permutation, and row (or column) symmetric ma-trices as its special cases, is proposed, and a precise corre-spondence of singular values and singular vectors between the unitary symmetric matrix and its mother matrix is de-rived. As an illustration of potential, it is shown that, for a class of unitary symmetric matrices, the singular value decomposition (SVD) using the mother matrix rather than the unitary symmetric matrix per se can save dramatically the CPU time and memory without loss of any numerical precision.

  4. The R-matrix theory

    Energy Technology Data Exchange (ETDEWEB)

    Descouvemont, P; Baye, D [Physique Nucleaire Theorique et Physique Mathematique, C.P. 229, Universite Libre de Bruxelles (ULB), B 1050 Brussels (Belgium)], E-mail: pdesc@ulb.ac.be, E-mail: dbaye@ulb.ac.be

    2010-03-15

    The different facets of the R-matrix method are presented pedagogically in a general framework. Two variants have been developed over the years: (i) The 'calculable' R-matrix method is a calculational tool to derive scattering properties from the Schroedinger equation in a large variety of physical problems. It was developed rather independently in atomic and nuclear physics with too little mutual influence. (ii) The 'phenomenological' R-matrix method is a technique to parametrize various types of cross sections. It was mainly (or uniquely) used in nuclear physics. Both directions are explained by starting from the simple problem of scattering by a potential. They are illustrated by simple examples in nuclear and atomic physics. In addition to elastic scattering, the R-matrix formalism is applied to inelastic and radiative-capture reactions. We also present more recent and more ambitious applications of the theory in nuclear physics.

  5. The Derivation and Analysis of Spherical Panorama Epipolar Line Based on Essential Matrix%利用本质矩阵对球形全景核线进行推导与分析

    Institute of Scientific and Technical Information of China (English)

    刘帅; 陈军; 孙敏; 赵伶俐

    2016-01-01

    针对立体全景构模中缺乏核线特性规律分布研究及其可靠性检验的问题,通过对球形全景影像的投影几何进行深入分析,利用计算机多视几何的本质矩阵建立该类影像的核线几何模型,推导出数学方程及轨迹特性,并对其分布规律进行了统计分析,为核线在球形全景影像中的应用提供了理论基础.实验结果证明,文中推导的球形全景核线方程是正确的,在实际应用中是可行的.%The epipolar geometry is a core issue in computer vision and close-range digital photogrammetry, which could limit the search range to improve calculation efficiency and reliability of the matching. Cur-rently, epipolar constraint has achieved a wide range of applications in the traditional center of the projected images and satellite images. However, it made greater difficulties for panorama because of the different geometric modeling and projection transformation, especially lacking research on the distribution and reli-ability test of the epipolar line. So the paper constructs the panoramic epipolar geometry based on essential matrix, deriving the mathematical equations and its property, and analyzes spherical panoramic epipolar line distribution statistically, thus providing a theoretical basis for the spherical panoramic epipolar line used in computer vision and close-range digital photogrammetry. The experimental results show that the epipolar line is much validated, which can decrease search range, and something useful is obtained.

  6. Matrix subordinators and related Upsilon transformations

    DEFF Research Database (Denmark)

    Barndorff-Nielsen, Ole Eiler; Pérez-Abreu, V.

    2008-01-01

    A class of upsilon transformations of Lévy measures for matrix subordinators is introduced. Some regularizing properties of these transformations are derived, such as absolute continuity and complete monotonicity. The class of Lévy measures with completely monotone matrix densities is characterized....... Examples of infinitely divisible nonnegative definite random matrices are constructed using an upsilon transformation....

  7. Drought Forecast Application of BP Prediction Models Based on EMD in Ling River Basin%基于EMD的BP神经网络在凌河流域旱灾预测中的应用

    Institute of Scientific and Technical Information of China (English)

    于洋; 迟道才; 陈涛涛; 孙淼; 栾策

    2014-01-01

    为提高旱灾预测模型预测精度,利用EMD(经验模态分解法)处理非平稳信号的优势,将其应用到BP神经网络预测模型中,建立基于EMD的BP神经网络旱灾预测模型,对凌河流域44个观测站(小凌河流域11站、大凌河流域33站)共51年(1960~2010)的降水资料进行旱灾预测应用,同时将基于EMD的BP神经网络旱灾预测模型结果与BP神经网络预测模型结果进行对比。结果表明:小凌河流域基于EMD的BP神经网络预测模型、BP神经网络预测模型的年均降水量预测值均方误差(MSE)分别为0.0011和0.0076,决定系数(R2)分别为0.95和0.83;大凌河流域基于EMD的BP神经网络预测模型、BP神经网络模型的年均降水量预测值均方误差(MSE)分别为0.0032和0.0092,决定系数(R2)分别为0.93和0.79。基于EMD的BP神经网络预测值均方误差(MSE)较小且决定系数(R2)较高,均优于BP神经网络预测值,提高了BP神经网络旱灾预测模型预测精度,具有一定的可行性。%To improve the accuracy of drought prediction, the EMD (Empirical Mode Decomposition) in processing non-stationary single was used to establish BP neural network forecast model. A drought prediction model was established to conduct a drought prediction for precipitation data from 44 stations (11 stations in Xiaoling River Basin, 33 stations in Daling River Basin) in a total of 51 years (1960-2010) in Ling River Basin and compare the forecast results obtaining from BP neural network prediction model and results from EMD of BP neural network. Results showed that the annual average rainfall prediction mean square error (MSE) based on EMD of BP neural network prediction model and BP neural network prediction model in Xiaoling River Basin were 0.0011 and 0.0076, determination coefficient (R2) were 0.95 and 0.83, The annual average rainfall prediction mean square error(MSE) based on EMD of BP neural network prediction model and BP neural

  8. Riemann Zeta Matrix Function

    OpenAIRE

    Kargın, Levent; Kurt, Veli

    2015-01-01

    In this study, obtaining the matrix analog of the Euler's reflection formula for the classical gamma function we expand the domain of the gamma matrix function and give a infinite product expansion of sinπxP.  Furthermore we define Riemann zeta matrix function and evaluate some other matrix integrals. We prove a functional equation for Riemann zeta matrix function.

  9. Uniqueness of the differential Mueller matrix of uniform homogeneous media.

    Science.gov (United States)

    Devlaminck, Vincent; Ossikovski, Razvigor

    2014-06-01

    We show that the differential matrix of a uniform homogeneous medium containing birefringence may not be uniquely determined from its Mueller matrix, resulting in the potential existence of an infinite set of elementary polarization properties parameterized by an integer parameter. The uniqueness depends on the symmetry properties of a special differential matrix derived from the eigenvalue decomposition of the Mueller matrix. The conditions for the uniqueness of the differential matrix are identified, physically discussed, and illustrated in examples from the literature.

  10. A note on combined generalized Sylvester matrix equations

    Institute of Scientific and Technical Information of China (English)

    Guangren DUAN

    2004-01-01

    The solution of two combined generalized Sylvester matrix equations is studied.It is first shown that the two combined generalized Sylvester matrix equations can be converted into a normal Sylvester matrix equation through extension,and then with the help of a result for solution to normal Sylvester matrix equations,the complete solution to the two combined generalized Sylvester matrix equations is derived.A demonstrative example shows the effect of the proposed approach.

  11. EMD与CWD结合在暂态电能质量扰动检测中的应用%Application of united EMD and CWD to detection of disturbance to transient power quality

    Institute of Scientific and Technical Information of China (English)

    郭晓婷; 刘伟; 李建

    2012-01-01

    In order to suppress the cross term interference in the Cohen-class quadratic time-frequency distribution, a method was proposed based on empirical mode decomposition (EMD) and Choi-Williams distribution. In this method, several intrinsic mode functions (IMFs) of the signals were separated from the frequency domain by using EMD. The time-frequency transformation of Cohen-class distribution was carried out after deleting the false components generated by EMD, and then the Cohen-class time-frequency distribution of original signal was reconstructed by means of linear superposition of the IMFs Cohen-class distribution results. Simulation results showed that the method could be used to suppress effectively the cross terms of Cohen-class distribution, ensure Cohen-class distribution time-frequency concentration, and extract disturbance features.%针对Cohen类二次型时频分布存在的交叉项,提出一种基于EMD与Choi-Williams分布相结合的方法,利用经验模态分解将信号从频域上分离若干个固有模态函数经过去伪后进行Cohen分布的时频变换,将得到的结果叠加重构出原始信号的Cohen类时频分布.仿真结果表明,该方法能有效抑制时频分布的交叉项,保证Cohen分布的时频聚集性,提取扰动特征.

  12. Phase I/II open-label study of the biologic effects of the interleukin-2 immunocytokine EMD 273063 (hu14.18-IL2 in patients with metastatic malignant melanoma

    Directory of Open Access Journals (Sweden)

    Gillies Stephen D

    2009-07-01

    Full Text Available Abstract Background To explore the biological activity of EMD 273063 (hu14.18-IL2, a humanized anti-GD2 monoclonal antibody fused to interleukin-2 (IL2, in patients with unresectable, stage IV cutaneous melanoma as measured by induction of immune activation at the tumor site and in peripheral blood. Methods Nine patients were treated with 4 mg/m2 per day of EMD 273063 given as a 4-h intravenous infusion on days 1, 2, and 3 every four weeks (one cycle. Peripheral blood was analyzed for T cell and natural killer cell phenotype and frequency, as well as levels of soluble IL2 receptor (sIL2R, IL10, IL6, tumor necrosis factor alpha and neopterin. Biopsies of tumor metastasis were performed prior to therapy and at day 10 of the first 2 cycles to study lymphocyte accumulation by immunohistochemistry. Results Treatment was generally well tolerated and there were no study drug-related grade 4 adverse events. Grade 3 events were mainly those associated with IL2, most commonly rigors (3 patients and pyrexia (2 patients. Best response on therapy was stable disease in 2 patients. There were no objective tumor regressions by standard response criteria. Systemic immune activation was demonstrated by increases in serum levels of sIL2R, IL10, and neopterin. There was evidence of increased tumor infiltration by T cells, but not NK cells, in most post-dosing biopsies, suggesting recruitment of immune cells to the tumor site. Conclusion EMD 273063 demonstrated biologic activity with increased immune-related cytokines and intratumoral changes in some patients consistent with the suspected mechanism of action of this immunocytokine.

  13. 基于EMD与三阶累积量的水声瞬态信号检测%Detection of underwater acoustic transient signal based on EMD and third-order cumulant

    Institute of Scientific and Technical Information of China (English)

    何光进; 程锦房; 许杰; 李楠; 张炜

    2012-01-01

    提出了基于经验模态分解(EMD)与三阶累积量的水声瞬态信号检测方法.首先根据EMD方法的滤波器特性将待检信号在频域内分成一系列的本征模态函数(IMF)分量,并根据能量法选择信号占主导地位的IMF;然后运用高阶累积量抑制高斯信号的特性,计算IMF分量三阶累积量对角切片的短时估计,并构造检测函数,对检测函数时行包络检波,作为检测标准;最后用仿真数据对该方法进行了验证,结果表明能在较低信噪比下检测出目标信号的出现时刻和大致频率,具有一定的工程应用价值.%A detection method of underwater acoustic transient signals based on EMD and third order cumulant was presented in the paper. First, EMD method was employed to decompose the signal into a group of IMFs according to their frequencies. The IMF with bigger energy power was chosen as the useful component. Then third-order cumulant was used to depress the white Gaussian noise and the short-time estimation of third-order cumulant diagonal slice can be received during the process. A detection function which is based on short-time estimation and its envelope were recognized as the detection statistic to determine whether there are transient signals. At last, simulated data were used to test the effect of the method. The results illustrate that the detection method based on EMD and third-order cumulant can detect the underwater acoustic transient signals at lower SNRs, which is very valuable in the engineering application.

  14. 氧阴极节能环保制备电解二氧化锰新方法%New Energy-saving and Green Method of Preparation of EMD in Using Oxygen Cathode

    Institute of Scientific and Technical Information of China (English)

    张慧; 孟惠民; 郭琳; 俞宏英; 孙冬柏

    2013-01-01

    The electrolytic manganese dioxide (EMD) production in using graphite or copper hydrogen evolution cathode is high energy consumption, pollution and risks. To keep anodic reaction unchanged, a theoretically cell voltage cut of 1. 229 V can be obtained through the introduction of the electrolysis cell based on a gas diffusion cathode (GDE) of the green oxygen reduction reaction. Meanwhile, the acid mist will be reduced on the cathode. Studying the new synthetic method of EMD in using oxygen cathode for energy saving and environment friendly, it is confirmed that the cell voltage and energy consumption of new method by using GDE ( Pt/C type) will be 1/3 ~ 1/2 of that by using Cu and Pt cathode, compared with the traditional Cu and Pt hydrogen evolution cathode, at the current density of 20 ~ 140 A o m-2. XRD analysis shows that the anodic deposition of the powder belongs to γ -MnO2. The new method has obtained patent licenses.%采用石墨、铜等析氢阴极进行电解二氧化锰(EMD)生产时存在高耗能、环境污染、安全隐患等问题,用高电位的气体扩散电极(GDE)等氧阴极代替传统的析氢阴极,在阳极反应不变的情况下,可以使传统EMD方法的理论槽电压降低1.229 V,同时阴极不会析出氢气也可减少酸雾的产生.对此“节能环保型氧阴极电解二氧化锰新方法”的研究证实:阴极用GDE后,在电流密度范围20 ~ 140 A/m2,与传统Cu和电催化活性特别好的Pt析氢阴极反应电解槽相比,使用Pt/C型GDE氧还原阴极反应EMD新方法的槽电压和能耗仅为他们的1/3 ~ 1/2.对阳极沉积出的粉末进行XRD分析也表明是所要求的EMD(γ-MnO2).新方法已取得专利授权.

  15. Supersymmetry in random matrix theory

    Energy Technology Data Exchange (ETDEWEB)

    Kieburg, Mario

    2010-05-04

    I study the applications of supersymmetry in random matrix theory. I generalize the supersymmetry method and develop three new approaches to calculate eigenvalue correlation functions. These correlation functions are averages over ratios of characteristic polynomials. In the first part of this thesis, I derive a relation between integrals over anti-commuting variables (Grassmann variables) and differential operators with respect to commuting variables. With this relation I rederive Cauchy- like integral theorems. As a new application I trace the supermatrix Bessel function back to a product of two ordinary matrix Bessel functions. In the second part, I apply the generalized Hubbard-Stratonovich transformation to arbitrary rotation invariant ensembles of real symmetric and Hermitian self-dual matrices. This extends the approach for unitarily rotation invariant matrix ensembles. For the k-point correlation functions I derive supersymmetric integral expressions in a unifying way. I prove the equivalence between the generalized Hubbard-Stratonovich transformation and the superbosonization formula. Moreover, I develop an alternative mapping from ordinary space to superspace. After comparing the results of this approach with the other two supersymmetry methods, I obtain explicit functional expressions for the probability densities in superspace. If the probability density of the matrix ensemble factorizes, then the generating functions exhibit determinantal and Pfaffian structures. For some matrix ensembles this was already shown with help of other approaches. I show that these structures appear by a purely algebraic manipulation. In this new approach I use structures naturally appearing in superspace. I derive determinantal and Pfaffian structures for three types of integrals without actually mapping onto superspace. These three types of integrals are quite general and, thus, they are applicable to a broad class of matrix ensembles. (orig.)

  16. The effect of Emdogain and platelet-derived growth factor on the osteoinductive potential of hydroxyapatite tricalcium phosphate.

    Science.gov (United States)

    Chan, R C; Marino, V; Bartold, P M

    2012-08-01

    The aim of this study was to determine whether hydroxyapatite β-tricalcium phosphate (HA-TCP) either alone or coated with Emdogain (EMD) or recombinant human platelet-derived growth factor-BB (rhPDGF-BB) becomes osteoinductive in the murine thigh muscle model for osteoinduction. Twenty CD1 adult male mice had gelatin capsules implanted into the thigh muscle of both hind limbs. The capsules were either empty or contained one of the following: uncoated particulate HA-TCP, EMD-coated HA-TCP or rhPDGF-BB-coated HA-TCP. The implant sites were assessed histologically at 4 and 8 weeks. A semi-quantitative histological examination was performed to assess the inflammatory changes, reparative processes and osteoinduction within the graft site. At both 4 and 8 weeks, histological analysis failed to demonstrate any osteoinductive activity in any of the specimens from the experimental groups. A minimal chronic inflammatory response and foreign body reaction around the implanted materials was seen which reduced over time. The HA-TCP particles were embedded within fibrous connective tissue and were encapsulated by a dense cellular layer consisting of active fibroblasts and occasional macrophages with the thickness of this layer decreasing over time. The results of this study suggest that the use of commercially available HA-TCP alone or in combination with EMD or rhPDGF-BB is biocompatible but not osteoinductive in the murine thigh muscle model of osteoinduction. Coating HA-TCP with EMD or rhPDGF-BB does not enhance its osteoinductive potential.

  17. New recursive algorithm for matrix inversion

    Institute of Scientific and Technical Information of China (English)

    Cao Jianshu; Wang Xuegang

    2008-01-01

    To reduce the computational complexity of matrix inversion, which is the majority of processing in many practical applications, two numerically efficient recursive algorithms (called algorithms Ⅰ and Ⅱ, respectively)are presented. Algorithm Ⅰ is used to calculate the inverse of such a matrix, whose leading principal minors are all nonzero. Algorithm Ⅱ, whereby, the inverse of an arbitrary nonsingular matrix can be evaluated is derived via improving the algorithm Ⅰ. The implementation, for algorithm Ⅱ or Ⅰ, involves matrix-vector multiplications and vector outer products. These operations are computationally fast and highly parallelizable. MATLAB simulations show that both recursive algorithms are valid.

  18. Acupuncture combined with curcumin disrupts platelet-derived growth factor β receptor/extracellular signal-regulated kinase signalling and stimulates extracellular matrix degradation in carbon tetrachloride-induced hepatic fibrosis in rats

    National Research Council Canada - National Science Library

    Zhang, Xiao-Ping; Zhang, Feng; Zhang, Zi-Li; Ma, Jin; Kong, De-Song; Ni, Guang-Xia; Wang, Ai-Yun; Chen, Wen-Xing; Lu, Yin; Zheng, Shi-Zhong

    2012-01-01

    ...) signalling and extracellular matrix (ECM) regulation in the fibrotic liver. A total of 60 Sprague-Dawley male rats were randomly divided into control, model, sham, acupuncture, curcumin and combination treatment groups...

  19. Components of enamel matrix derivative and cyto-differentiation induction effects: A literature review%釉基质蛋白组成及诱导细胞分化研究进展

    Institute of Scientific and Technical Information of China (English)

    邹慧儒; 张兰成; 秦宗长; 杨学斌; Steven Brookes

    2012-01-01

    背景:研究表明,釉基质蛋白不仅能够诱导牙周组织再生,还对其他类型的细胞也有不同程度的作用效果.目的:综述釉基质蛋白的组成成分及其在诱导干细胞分化方面的研究进展,深入解析釉基质蛋白的生物模拟作用及其可能的机制.方法:应用计算机检索中国生物医学文献数据库,中国知网,万方、维普数据库1997-01/2011-12相关文献,检索词"釉基质蛋白,分化"限定文献语言种类为中文.同时计算机检索PubMed,EBSCO HOST数据库1997-01/2011-12相关文献,检索词"Enamel matrix derivative,Emdogain?,differentiation",限定文献种类为英文.手工检索美国化学文摘数据库,荷兰医学文摘,进行文献初检.筛选后纳入38篇文章进行综述.结果与结论:釉基质蛋白组成成分复杂,包含有多种蛋白和类生长因子物质.釉基质蛋白具有生物模拟效果,对不同类型的干细胞具有不同程度的促进或抑制分化作用.提示釉基质蛋白将有可能不仅应用于牙周疾病的治疗,还可能应用于其他组织再生领域.

  20. Tame-wild dichotomy for derived categories

    OpenAIRE

    Bekkert, Viktor I.; Drozd, Yuriy A.

    2003-01-01

    We prove that every finite dimensional algebra over an algebraically closed field is either derived tame or derived wild. The proof is based on the technique of matrix problems (boxes and reduction algorithm). It implies, in particular, that any degeneration of a derived wild algebra is derived wild; respectively, any deformation of a derived tame algebra is derived tame.

  1. 液态Co物性的平衡及非平衡分子动力学模拟%Physical properties of liquid Co by EMD and NEMD method

    Institute of Scientific and Technical Information of China (English)

    韩秀峰; 王伟民; 彭传校

    2006-01-01

    The equilibrium molecular dynamics (EMD) simulation has been performed to calculate physical properties such as self-diffusion coefficient and shear viscosity of Co melt using embedded atom method (EAM). By contrast, we calculate the shear viscosity of Co via Nonequilibrium molecular dynamics (NEMD) method subjected to a planar Couette shear flow. This study shows that computations of these transport properties are feasible and reliable and can give a representative dynamics property of liquid Co.%本文采用EAM作用势,通过平衡分子动力学(EMD)模拟的方法计算了Co熔体的自扩散系数、剪切粘度等物理性质.同时采用非平衡分子动力学(NEMD)方法计算了Co的剪切粘度.研究表明有关传输性质的计算是可与实验比较的,能够反映出液态Co典型的动力学特性.

  2. 利用各向异性高斯方向导数相关矩阵的角点检测方法%A Corner Detection Algorithm Using Anisotropic Gaussian Directional Derivatives Autocorrelation Matrix on Edge Contours

    Institute of Scientific and Technical Information of China (English)

    章为川; 水鹏朗; 朱磊

    2012-01-01

    为了抑制图像边缘上的局部变化和噪声对角点检测的影响,提出了利用各向异性高斯方向导数自相关矩阵的角点检测算法.该算法首先利用Canny边缘检测器提取图像的边缘映射;然后用各向异性高斯方向导数滤波器对输入图像进行平滑,对每个边缘像素,利用它与相邻像素之间方向导数的相关性构造自相关矩阵;若边缘像素点的自相关矩阵所对应的归一化特征值的和是局部极大值,则标记该点为角点.与传统的基于轮廓的角点检测方法不同,文中提出的方法利用的是邻近像素的方向导数的相关信息,而不是轮廓曲线的曲率,因而具有更好的稳健性.实验结果表明:在无噪声和含噪声的条件下,该检测方法与已有的3种算法相比,平均配准角点数分别提高了7.4%和9.3%左右,平均定位误差分别降低了10%和15.2%左右.%A new corner detection algorithm based on the anisotropic Gaussian directional derivatives (ANDDs) autocorrelation matrix on edge contours is proposed to suppress noise and local variation, and to detect corners effectively. Firstly, the edge map of an image is extracted by the Canny edge detector. Secondly, the input image is smoothed by the ANDD filters; autocorrelation matrices are constructed for each edge pixel by the directional derivatives correlation of the pixel and its surrounding pixels. Finally, the contour pixels with local maxima of the sum of the normalized eigenvalues are labeled as corners. The proposed algorithm is different from the traditional contour-based detectors, and it uses the intensity variation auto-information on contours and their surrounding pixels rather than the curvatures of the planar curves, hence has better robustness to noise. Experimental results and comparisons with several state-of-art algorithms in both the noise-free and noise cases show that the average matched corner numbers of the proposed algorithm increase by

  3. Model Reduction via Reducibility Matrix

    Institute of Scientific and Technical Information of China (English)

    Musa Abdalla; Othman Alsmadi

    2006-01-01

    In this work, a new model reduction technique is introduced. The proposed technique is derived using the matrix reducibility concept. The eigenvalues of the reduced model are preserved; that is, the reduced model eigenvalues are a subset of the full order model eigenvalues. This preservation of the eigenvalues makes the mathematical model closer to the physical model. Finally, the outcomes of this method are fully illustrated using simulations of two numeric examples.

  4. Enhanced proliferation, attachment and osteopontin expression by porcine periodontal cells exposed to Emdogain.

    Science.gov (United States)

    Rincon, J C; Xiao, Y; Young, W G; Bartold, P M

    2005-12-01

    Emdogain (EMD) is an enamel matrix derivative extracted from developing porcine teeth with demonstrated periodontal regenerative potential. EMD has been shown to influence a number of properties of periodontal ligament cells including proliferation, cell attachment and matrix synthesis. To date, the effect of EMD on the epithelial cell rests of Malassez (ERM) is unknown. In this study, periodontal ligament fibroblasts, ERM, alveolar bone cells and gingival fibroblasts were obtained from porcine periodontal ligament, alveolar bone and gingiva. This study investigated, in vitro, the effect of EMD at three concentrations on proliferation, cell attachment and expression of mRNA for two mineralised tissue-related proteins (osteopontin and bone sialoprotein). As for other periodontal cells, the ERM proliferative response was enhanced by EMD. Attachment assays revealed a highly significant increase for ERM and gingival fibroblasts after EMD treatment at all concentrations. This study has also shown that EMD stimulated expression of osteopontin mRNA by ERM and alveolar bone cells. The results from this study provide evidence that EMD enhanced cellular events related with proliferation, attachment and osteopontin mRNA expression by porcine periodontal cells, in a manner consistent with its role in periodontal regenerative therapy.

  5. Detection of ship shaft-rate electric field signal based on EMD and fourth-order mixed cumulant%基于EMD和四阶混合累积量的船舶轴频电场检测

    Institute of Scientific and Technical Information of China (English)

    程锐; 姜润翔; 龚沈光

    2015-01-01

    为实现低信噪比情况下微弱的船舶轴频电场信号的有效检测 ,提出了一种结合经验模态分解(empiri-cal mode decomposition ,EMD)和四阶混合累积量对角切片滑动功率谱的方法.首先 ,利用EMD将信号自适应地进行子带分解 ,对得到的本征模态函数(intrinsic mode functions ,IM F)采用相关系数准则进行筛选 ;然后 ,利用高阶累积量可抑制高斯色噪声的特性 ,计算各有效IM F分量的四阶混合累积量对角切片的功率谱 ,并进行了多子带中的滑动检测.实测数据处理结果表明 :该方法具有较好的应用价值.%In order to implement effective detection of weak ship shaft-rate electric field signal under low signal to noise ratio (SNR) ,a method combining empirical mode decomposition (EMD) with sli-ding power spectrum of fourth-order mixed cumulant diagonal slice is proposed .Firstly ,EMD method is employed to adaptively decompose the signal into a set of intrinsic mode functions (IMFs) ,from which the valid ones are selected according to correlation coefficient criterion .Then ,by exploiting the property of higher order cumulant which can suppress Gaussian colored noise ,power spectrum of fourth-order mixed cumulant diagonal slice of selected IM Fs is calculated ,w hich is then used for slid-ing detection in multiple sub-bands .The result of processing practical data illustrates that this method is of great value in application .

  6. Repair of calvarial defects with human umbilical cord blood derived mesenchymal stem cells and demineralized bone matrix in athymic rats%人脐血间充质干细胞修复颅骨缺损的实验研究

    Institute of Scientific and Technical Information of China (English)

    刘广鹏; 李宇琳; 孙剑; 崔磊; 张文杰; 曹谊林

    2010-01-01

    Objective To investigate the feasibility of using human umbilical cord blood derived mesenchymal stem cells (UCB-MSCs) and demineralized bone matrix (DBM) scaffolds to repair critical-sized calvarial defects in athymic rats. Methods Human UCB-MSCs were isolated, expanded and osteogenically induced in vitro. Osteogenic differentiation of UCB-MSCs was evaluated by Alizarin Red staining and measurement of calcium content respectively, and then the cells were seeded onto DBM scaffolds. Bilateral full-thickness defects (5 mm in diameter) of parietal bone were created in an athymic rat model. The defects were either repaired with UCB-MSC/DBM constructs (experimental group) or with DBM scaffolds alone (control group). Animals were harvested at 6 and 12 weeks post-implantation respectively, and defect repair was evaluated with gross observation, micro-CT measurement and histological analysis. Results Micro-CT showed that new bone was formed in the experimental group at 6 weeks post-implantation, while no sign of new bone formation was observed in the control group. At 12 weeks post-transplantation, scaffolds had been degraded almost completely in both sides. It was shown that an average of (78.19±6.45)% of each defect volume had been repaired in experimental side; while in the control side, only limited bone formed at the periphery of the defect. Histological examination revealed that the defect was repaired by trabecular bone tissue in experimental side at 12 weeks, while only fibrous connection was observed in the control group. Conclusions Tissue-engineered bone composed of osteogenically-induced human UCB-MSCs on DBM scaffolds could successfully repair the critical-sized calvarial defects in athymic rat models.%目的 应用人脐血间充质干细胞(umbilical cord blood derived mesenchymal stem cells,UCB-MSCs)复合脱钙骨材料构建组织工程化骨,修复裸大鼠颅骨标准缺损.方法 体外扩增培养、成骨诱导人UCB-MSCs,采用Alizarin Red染色

  7. The Matrix Cookbook

    DEFF Research Database (Denmark)

    Petersen, Kaare Brandt; Pedersen, Michael Syskind

    Matrix identities, relations and approximations. A desktop reference for quick overview of mathematics of matrices.......Matrix identities, relations and approximations. A desktop reference for quick overview of mathematics of matrices....

  8. Matrix with Prescribed Eigenvectors

    Science.gov (United States)

    Ahmad, Faiz

    2011-01-01

    It is a routine matter for undergraduates to find eigenvalues and eigenvectors of a given matrix. But the converse problem of finding a matrix with prescribed eigenvalues and eigenvectors is rarely discussed in elementary texts on linear algebra. This problem is related to the "spectral" decomposition of a matrix and has important technical…

  9. Correlation matrix for quartet codon usage

    CERN Document Server

    Frappat, L; Sorba, Paul

    2005-01-01

    It has been argued that the sum of usage probabilities for codons, belonging to quartets, that have as third nucleotide C or A, is independent of the biological species for vertebrates. The comparison between the theoretical correlation matrix derived from these sum rules and the experimentally computed matrix for 26 species shows a satisfactory agreement. The Shannon entropy, weakly depending on the biological species, gives further support. Suppression of codons containing the dinucleotides CG or AU is put in evidence.

  10. Matrix parameters and storage conditions of manure

    Energy Technology Data Exchange (ETDEWEB)

    Weinfurtner, Karlheinz [Fraunhofer Institute for Molecular Biology and Applied Ecology (IME), Schmallenberg (Germany)

    2011-01-15

    The literature study presents an overview of storage conditions for manure and information about important matrix parameters of manure such as dry matter content, pH value, total organic carbon, total nitrogen and ammonium nitrogen. The presented results show that for matrix parameters a dissimilarity of cattle and pig manure can be observed but no difference within the species for different production types occurred with exception of calves. A scenario for western and central European countries is derived. (orig.)

  11. Matrix Coherence and the Nystrom Method

    CERN Document Server

    Talwalkar, Ameet

    2010-01-01

    The Nystrom method is an efficient technique to speed up large-scale learning applications by generating low-rank approximations. Crucial to the performance of this technique is the assumption that a matrix can be well approximated by working exclusively with a subset of its columns. In this work we relate this assumption to the concept of matrix coherence and connect matrix coherence to the performance of the Nystrom method. Making use of related work in the compressed sensing and the matrix completion literature, we derive novel coherence-based bounds for the Nystrom method in the low-rank setting. We then present empirical results that corroborate these theoretical bounds. Finally, we present more general empirical results for the full-rank setting that convincingly demonstrate the ability of matrix coherence to measure the degree to which information can be extracted from a subset of columns.

  12. Spectral clustering based on matrix perturbation theory

    Institute of Scientific and Technical Information of China (English)

    TIAN Zheng; LI XiaoBin; JU YanWei

    2007-01-01

    This paper exposes some intrinsic characteristics of the spectral clustering method by using the tools from the matrix perturbation theory. We construct a weight matrix of a graph and study its eigenvalues and eigenvectors. It shows that the number of clusters is equal to the number of eigenvalues that are larger than 1, and the number of points in each of the clusters can be approximated by the associated eigenvalue. It also shows that the eigenvector of the weight matrix can be used directly to perform clustering; that is, the directional angle between the two-row vectors of the matrix derived from the eigenvectors is a suitable distance measure for clustering. As a result, an unsupervised spectral clustering algorithm based on weight matrix (USCAWM) is developed. The experimental results on a number of artificial and real-world data sets show the correctness of the theoretical analysis.

  13. EMD与LMD在BCI脑电信号分析中的比较研究%Research on the Comparison between EMD and LMD in Feature Extraction of EEG in Brain Computer Interface

    Institute of Scientific and Technical Information of China (English)

    朱晓琳; 刘建平

    2014-01-01

    经验模态分解(EMD)和局域均值分解(LMD)作为近年来新兴的时频分析方法,在处理非线性、非平稳的脑电信号方面具有独特的优势.本文从多个角度对EMD和LMD在BCI脑电信号分析中的特点进行了比较研究,分析了两种方法在对BCI脑电信号进行不同时频尺度分解时的优缺点,为更好的使用和完善两种方法提供依据.

  14. 基于EMD分解和共振解调的滚动轴承故障诊断研究%Research on Rolling Bearing Fault Diagnosis Based on EMD Decomposition and Resonance Demodulation

    Institute of Scientific and Technical Information of China (English)

    左庆林; 马怀祥

    2014-01-01

    This paper introduces the fault mechanism of the rolling bearing , uses the vibration signal analy-sis method to research rolling bearing condition monitoring and fault diagnosis .Through the LabVIEW program-ming , combining the EMD decomposition and resonance demodulation , the vibration signal is analyzed , and use-ful fault features are obtained to confirm the fault types .%在介绍滚动轴承的故障机理的前提下,采用振动信号分析法对滚动轴承状态监测和故障诊断进行研究。通过LabVIEW编程,应用EMD分解和共振解调相结合的方法,对振动信号进行分析,获取有用故障特征,进而确定故障类型。

  15. The Impact of the Monetary Policy on the Asset Price in Different Periods——Based on EMD%货币政策在不同时期对资产价格的EMD分析

    Institute of Scientific and Technical Information of China (English)

    张青蕾; 李倩; 彭晓晖; 张峰

    2012-01-01

    研究致力于将一种新的信号分解方法,即经验模态分解(EMD)方法,运用于分析央行货币政策对资产价格波动的影响,对资产价格进行分解,对所得到的各个本征模函数进行平均周期计算和统计学分析,分析了剔除短期市场因素对分析信号的影响,找出其中反应货币政策影响关系的分量部分.认为货币政策确实对我国的资产市场产生影响,并且在不同时期的影响效果是不同的,政府应该充分发挥货币政策的调节作用促进我国经济的健康发展.%By using a new method of signal analysis called Empirical Mode Decomposition (EMD) ,the impact of the monetary policy on the asset price is analysed. First we break down the signs of the asset price to get several IMFs. Then we calculate the mean periods of the IMFs and do some statistical analysis about these IMFs. We try to remove the short-term elements which affect the asset price,and distinguish the parts which present the impact of the monetary policy. After the study,it is shown that the impact of the monetary policy on the asset price exists and the result changes in different periods. It is believed that the government should make full use of the monetary policy to promote the healthy development of the economy.

  16. 基于EMD小波包和ANFIS的滚动轴承故障诊断%Application of EMD-wavelet packet and ANFIS for rolling bearing fault diagnosis

    Institute of Scientific and Technical Information of China (English)

    张霆; 张友鹏

    2013-01-01

    为了有效识别出滚动轴承的内圈故障、外圈故障、滚动体故障三种故障类型,提出一种基于经验模态分解EMD的小波包去噪和自适应神经模糊推理系统ANFIS的诊断方法。对故障信号进行去噪预处理,对已处理的信号利用ANFIS进行故障识别。结果表明,采用基于EMD的小波包去噪方法能有效地提高信噪比,在去噪的基础上,采用ANFIS进行故障诊断,诊断结果的误差低,能很好地识别出上述三种故障类型。%In order to diagnose rolling bearing’s three fault types more effectively, such as inner race fault, outer race fault and balls fault, a method that Adaptive Neuro-Fuzzy Inference Systems(ANFIS)and wavelet packet de-noising based on Empirical Mode Decomposition(EMD)is proposed. As the signals are often corrupted by noise, so they are de-noised, and preprocessed signals are investigated using ANFIS analysis. The results show that the wavelet packet de-noising based on EMD can improve the Signal-to-Noise Ratio(SNR)effectively. After signals are preprocessed, the result of ANFIS analysis shows that average error is low. It can diagnose the three fault types above-mentioned better.

  17. A matrix model from string field theory

    Directory of Open Access Journals (Sweden)

    Syoji Zeze

    2016-09-01

    Full Text Available We demonstrate that a Hermitian matrix model can be derived from level truncated open string field theory with Chan-Paton factors. The Hermitian matrix is coupled with a scalar and U(N vectors which are responsible for the D-brane at the tachyon vacuum. Effective potential for the scalar is evaluated both for finite and large N. Increase of potential height is observed in both cases. The large $N$ matrix integral is identified with a system of N ZZ branes and a ghost FZZT brane.

  18. Partial chord diagrams and matrix models

    DEFF Research Database (Denmark)

    Andersen, Jørgen Ellegaard; Fuji, Hiroyuki; Manabe, Masahide

    spectrum. Furthermore, we consider the boundary length and point spectrum that unifies the last two types of spectra. We introduce matrix models that encode generating functions of partial chord diagrams filtered by each of these spectra. Using these matrix models, we derive partial differential equations......In this article, the enumeration of partial chord diagrams is discussed via matrix model techniques. In addition to the basic data such as the number of backbones and chords, we also consider the Euler characteristic, the backbone spectrum, the boundary point spectrum, and the boundary length...... – obtained independently by cut-and-join arguments in an earlier work – for the corresponding generating functions....

  19. A matrix model from string field theory

    Science.gov (United States)

    Zeze, Syoji

    2016-09-01

    We demonstrate that a Hermitian matrix model can be derived from level truncated open string field theory with Chan-Paton factors. The Hermitian matrix is coupled with a scalar and U(N) vectors which are responsible for the D-brane at the tachyon vacuum. Effective potential for the scalar is evaluated both for finite and large N. Increase of potential height is observed in both cases. The large N matrix integral is identified with a system of N ZZ branes and a ghost FZZT brane.

  20. Matrix elements from moments of correlation functions

    CERN Document Server

    Bouchard, Chris; Orginos, Kostas; Richards, David

    2016-01-01

    Momentum-space derivatives of matrix elements can be related to their coordinate-space moments through the Fourier transform. We derive these expressions as a function of momentum transfer $Q^2$ for asymptotic in/out states consisting of a single hadron. We calculate corrections to the finite volume moments by studying the spatial dependence of the lattice correlation functions. This method permits the computation of not only the values of matrix elements at momenta accessible on the lattice, but also the momentum-space derivatives, providing {\\it a priori} information about the $Q^2$ dependence of form factors. As a specific application we use the method, at a single lattice spacing and with unphysically heavy quarks, to directly obtain the slope of the isovector form factor at various $Q^2$, whence the isovector charge radius. The method has potential application in the calculation of any hadronic matrix element with momentum transfer, including those relevant to hadronic weak decays.

  1. Matrix elements from moments of correlation functions

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Chia Cheng [SLAC National Accelerator Lab., Menlo Park, CA (United States); Bouchard, Chris [College of William and Mary, Williamsburg, VA (United States); Orginos, Konstantinos [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); College of William and Mary, Williamsburg, VA (United States); Richards, David G. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)

    2016-10-01

    Momentum-space derivatives of matrix elements can be related to their coordinate-space moments through the Fourier transform. We derive these expressions as a function of momentum transfer Q2 for asymptotic in/out states consisting of a single hadron. We calculate corrections to the finite volume moments by studying the spatial dependence of the lattice correlation functions. This method permits the computation of not only the values of matrix elements at momenta accessible on the lattice, but also the momentum-space derivatives, providing {\\it a priori} information about the Q2 dependence of form factors. As a specific application we use the method, at a single lattice spacing and with unphysically heavy quarks, to directly obtain the slope of the isovector form factor at various Q2, whence the isovector charge radius. The method has potential application in the calculation of any hadronic matrix element with momentum transfer, including those relevant to hadronic weak decays.

  2. Experimental study on adipose tissue engineering with human adipose-derived stem cells and adipose tissue extracellular matrix scaffold%人细胞外基质支架联合脂肪干细胞构建脂肪组织

    Institute of Scientific and Technical Information of China (English)

    察鹏飞; 高建华; 陈阳; 鲁峰

    2012-01-01

    目的 探讨人脂肪组织细胞外基质(ECM)支架联合人脂肪来源干细胞(ADSCs)构建工程化脂肪组织的可行性.方法 以酶消化法从人抽脂术抽吸物脂质部分获取人ADSCs,体外进行多向分化诱导鉴定,并行DiI荧光标记.从抽脂术的脂质部分分离提取人脂肪组织细胞外基质,经过低温冻干、粉碎、灭菌等处理,制备成粉末状,电镜扫描观察表面特征并将其与ADSCs进行黏附实验,探讨其作为支架材料的可行性.收集人ADSCs,以2×109/L的细胞密度与提取的细胞外基质支架复合后移植于裸鼠背部皮下,同鼠对侧背部皮下移植ECM支架和细胞培养液作为对照,每侧移植0.5 ml,共6只实验鼠.8周后取材,称量标本湿重.取出的标本行苏木素-伊红(HE)染色和油红O染色进行定性判断,分析人脂肪组织ECM支架联合人ADSCs构建工程化脂肪组织的能力.结果 从脂肪组织中分离得到人ADSCs和ECM支架.ADSCs在相应的诱导环境下能够分化成为脂肪细胞、骨细胞和软骨细胞.ECM支架电镜扫描和大体观察具有疏松、多孔的结构特征,适合ADSCs的黏附生长.ADSCs与支架相容性良好,黏附率达(89.87±2.59)%,细胞在支架表面可充分伸展生长.体内移植8周后,实验组和对照组都能够形成新生物,湿重比较实验组较对照组重(P<0.05).经HE切片及油红O染色均证实实验组形成成熟的脂肪组织,对照组不能形成脂肪组织.结论 人脂肪组织ECM支架联合人ADSCs在体内能够成功构建成熟的脂肪组织,8周后支架并无明显吸收.%Objective To explore the possibility of building tissue-engineered adipose tissue with human adipose-derived stem cells (ADSCs) and adipose tissue extracellular matrix (ECM) scaffold,and provide experimental basis for clinical application of tissue-engineered adipose tissue for the repair of soft tissue defects.Methods ADSCs were isolated from adipose tissue by liposuction with the

  3. Triminimal parametrization of quark mixing matrix

    Science.gov (United States)

    He, Xiao-Gang; Li, Shi-Wen; Ma, Bo-Qiang

    2008-12-01

    Starting from a new zeroth order basis for quark mixing (CKM) matrix based on the quark-lepton complementarity and the tribimaximal pattern of lepton mixing, we derive a triminimal parametrization of a CKM matrix with three small angles and a CP-violating phase as its parameters. This new triminimal parametrization has the merits of fast convergence and simplicity in application. With the quark-lepton complementary relations, we derive relations between the two unified triminimal parametrizations for quark mixing obtained in this work and for lepton mixing obtained by Pakvasa-Rodejohann-Weiler. Parametrization deviating from quark-lepton complementarity is also discussed.

  4. Bioengineering Human Myocardium on Native Extracellular Matrix

    Science.gov (United States)

    Guyette, Jacques P.; Charest, Jonathan M; Mills, Robert W; Jank, Bernhard J.; Moser, Philipp T.; Gilpin, Sarah E.; Gershlak, Joshua R.; Okamoto, Tatsuya; Gonzalez, Gabriel; Milan, David J.; Gaudette, Glenn R.; Ott, Harald C.

    2015-01-01

    Rationale More than 25 million individuals suffer from heart failure worldwide, with nearly 4,000 patients currently awaiting heart transplantation in the United States. Donor organ shortage and allograft rejection remain major limitations with only about 2,500 hearts transplanted each year. As a theoretical alternative to allotransplantation, patient-derived bioartificial myocardium could provide functional support and ultimately impact the treatment of heart failure. Objective The objective of this study is to translate previous work to human scale and clinically relevant cells, for the bioengineering of functional myocardial tissue based on the combination of human cardiac matrix and human iPS-derived cardiac myocytes. Methods and Results To provide a clinically relevant tissue scaffold, we translated perfusion-decellularization to human scale and obtained biocompatible human acellular cardiac scaffolds with preserved extracellular matrix composition, architecture, and perfusable coronary vasculature. We then repopulated this native human cardiac matrix with cardiac myocytes derived from non-transgenic human induced pluripotent stem cells (iPSCs) and generated tissues of increasing three-dimensional complexity. We maintained such cardiac tissue constructs in culture for 120 days to demonstrate definitive sarcomeric structure, cell and matrix deformation, contractile force, and electrical conduction. To show that functional myocardial tissue of human scale can be built on this platform, we then partially recellularized human whole heart scaffolds with human iPSC-derived cardiac myocytes. Under biomimetic culture, the seeded constructs developed force-generating human myocardial tissue, showed electrical conductivity, left ventricular pressure development, and metabolic function. Conclusions Native cardiac extracellular matrix scaffolds maintain matrix components and structure to support the seeding and engraftment of human iPS-derived cardiac myocytes, and enable

  5. Parallelism in matrix computations

    CERN Document Server

    Gallopoulos, Efstratios; Sameh, Ahmed H

    2016-01-01

    This book is primarily intended as a research monograph that could also be used in graduate courses for the design of parallel algorithms in matrix computations. It assumes general but not extensive knowledge of numerical linear algebra, parallel architectures, and parallel programming paradigms. The book consists of four parts: (I) Basics; (II) Dense and Special Matrix Computations; (III) Sparse Matrix Computations; and (IV) Matrix functions and characteristics. Part I deals with parallel programming paradigms and fundamental kernels, including reordering schemes for sparse matrices. Part II is devoted to dense matrix computations such as parallel algorithms for solving linear systems, linear least squares, the symmetric algebraic eigenvalue problem, and the singular-value decomposition. It also deals with the development of parallel algorithms for special linear systems such as banded ,Vandermonde ,Toeplitz ,and block Toeplitz systems. Part III addresses sparse matrix computations: (a) the development of pa...

  6. Integrable matrix theory: Level statistics

    OpenAIRE

    2016-01-01

    We study level statistics in ensembles of integrable $N\\times N$ matrices linear in a real parameter $x$. The matrix $H(x)$ is considered integrable if it has a prescribed number $n>1$ of linearly independent commuting partners $H^i(x)$ (integrals of motion) $\\left[H(x),H^i(x)\\right] = 0$, $\\left[H^i(x), H^j(x)\\right]$ = 0, for all $x$. In a recent work, we developed a basis-independent construction of $H(x)$ for any $n$ from which we derived the probability density function, thereby determin...

  7. Phosphine in various matrixes

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Matrix-bound phosphine was determined in the Jiaozhou Bay coastal sediment, in prawn-pond bottom soil, in the eutrophic lake Wulongtan, in the sewage sludge and in paddy soil as well. Results showed that matrix-bound phosphine levels in freshwater and coastal sediment, as well as in sewage sludge, are significantly higher than that in paddy soil. The correlation between matrix bound phosphine concentrations and organic phosphorus contents in sediment samples is discussed.

  8. Polynomial Solutions to the Matrix Equation X−AXTB=C

    Directory of Open Access Journals (Sweden)

    Caiqin Song

    2014-01-01

    Full Text Available Solutions are constructed for the Kalman-Yakubovich-transpose equation X−AXTB=C. The solutions are stated as a polynomial of parameters of the matrix equation. One of the polynomial solutions is expressed by the symmetric operator matrix, controllability matrix, and observability matrix. Moreover, the explicit solution is proposed when the Kalman-Yakubovich-transpose matrix equation has a unique solution. The provided approach does not require the coefficient matrices to be in canonical form. In addition, the numerical example is given to illustrate the effectiveness of the derived method. Some applications in control theory are discussed at the end of this paper.

  9. Diagonally loaded SMI algorithm based on inverse matrix recursion

    Institute of Scientific and Technical Information of China (English)

    Cao Jianshu; Wang Xuegang

    2007-01-01

    The derivation of a diagonally loaded sample-matrix inversion (LSMI) algorithm on the busis of inverse matrix recursion (i.e. LSMI-IMR algorithm) is conducted by reconstructing the recursive formulation of covariance matrix. For the new algorithm, diagonal loading is by setting initial inverse matrix without any addition of computation. In addition, acorresponding improved recursive algorithm is presented, which is low computational complexity. This eliminates the complex multiplications of the scalar coefficient and updating matrix, resulting in significant computational savings.Simulations show that the LSMI-IMR algorithm is valid.

  10. Integrable matrix theory: Level statistics.

    Science.gov (United States)

    Scaramazza, Jasen A; Shastry, B Sriram; Yuzbashyan, Emil A

    2016-09-01

    We study level statistics in ensembles of integrable N×N matrices linear in a real parameter x. The matrix H(x) is considered integrable if it has a prescribed number n>1 of linearly independent commuting partners H^{i}(x) (integrals of motion) [H(x),H^{i}(x)]=0, [H^{i}(x),H^{j}(x)]=0, for all x. In a recent work [Phys. Rev. E 93, 052114 (2016)2470-004510.1103/PhysRevE.93.052114], we developed a basis-independent construction of H(x) for any n from which we derived the probability density function, thereby determining how to choose a typical integrable matrix from the ensemble. Here, we find that typical integrable matrices have Poisson statistics in the N→∞ limit provided n scales at least as logN; otherwise, they exhibit level repulsion. Exceptions to the Poisson case occur at isolated coupling values x=x_{0} or when correlations are introduced between typically independent matrix parameters. However, level statistics cross over to Poisson at O(N^{-0.5}) deviations from these exceptions, indicating that non-Poissonian statistics characterize only subsets of measure zero in the parameter space. Furthermore, we present strong numerical evidence that ensembles of integrable matrices are stationary and ergodic with respect to nearest-neighbor level statistics.

  11. Integrable matrix theory: Level statistics

    Science.gov (United States)

    Scaramazza, Jasen A.; Shastry, B. Sriram; Yuzbashyan, Emil A.

    2016-09-01

    We study level statistics in ensembles of integrable N ×N matrices linear in a real parameter x . The matrix H (x ) is considered integrable if it has a prescribed number n >1 of linearly independent commuting partners Hi(x ) (integrals of motion) "]Hi(x ) ,Hj(x ) ]">H (x ) ,Hi(x ) =0 , for all x . In a recent work [Phys. Rev. E 93, 052114 (2016), 10.1103/PhysRevE.93.052114], we developed a basis-independent construction of H (x ) for any n from which we derived the probability density function, thereby determining how to choose a typical integrable matrix from the ensemble. Here, we find that typical integrable matrices have Poisson statistics in the N →∞ limit provided n scales at least as logN ; otherwise, they exhibit level repulsion. Exceptions to the Poisson case occur at isolated coupling values x =x0 or when correlations are introduced between typically independent matrix parameters. However, level statistics cross over to Poisson at O (N-0.5) deviations from these exceptions, indicating that non-Poissonian statistics characterize only subsets of measure zero in the parameter space. Furthermore, we present strong numerical evidence that ensembles of integrable matrices are stationary and ergodic with respect to nearest-neighbor level statistics.

  12. Matrix-exponential distributions in applied probability

    CERN Document Server

    Bladt, Mogens

    2017-01-01

    This book contains an in-depth treatment of matrix-exponential (ME) distributions and their sub-class of phase-type (PH) distributions. Loosely speaking, an ME distribution is obtained through replacing the intensity parameter in an exponential distribution by a matrix. The ME distributions can also be identified as the class of non-negative distributions with rational Laplace transforms. If the matrix has the structure of a sub-intensity matrix for a Markov jump process we obtain a PH distribution which allows for nice probabilistic interpretations facilitating the derivation of exact solutions and closed form formulas. The full potential of ME and PH unfolds in their use in stochastic modelling. Several chapters on generic applications, like renewal theory, random walks and regenerative processes, are included together with some specific examples from queueing theory and insurance risk. We emphasize our intention towards applications by including an extensive treatment on statistical methods for PH distribu...

  13. [Modern polymers in matrix tablets technology].

    Science.gov (United States)

    Zimmer, Łukasz; Kasperek, Regina; Poleszak, Ewa

    2014-01-01

    Matrix tablets are the most popular method of oral drug administration, and polymeric materials have been used broadly in matrix formulations to modify and modulate drug release rate. The main goal of the system is to extend drug release profiles to maintain a constant in vivo plasma drug concentration and a consistent pharmacological effect. Polymeric matrix tablets offer a great potential as oral controlled drug delivery systems. Cellulose derivatives, like hydroxypropyl methylcellulose (HPMC) are often used as matrix formers. However, also other types of polymers can be used for this purpose including: Kollidon SR, acrylic acid polymers such as Eudragits and Carbopols. Nevertheless, polymers of natural origin like: carragens, chitosan and alginates widely used in the food and cosmetics industry are now coming to the fore of pharmaceutical research and are used in matrix tablets technology. Modern polymers allow to obtain matrix tablets by 3D printing, which enables to develop new formulation types. In this paper, the polymers used in matrix tablets technology and examples of their applications were described.

  14. 5D Black Holes and Matrix Strings

    CERN Document Server

    Dijkgraaf, R; Verlinde, Herman L

    1997-01-01

    We derive the world-volume theory, the (non)-extremal entropy and background geometry of black holes and black strings constructed out of the NS IIA fivebrane within the framework of matrix theory. The CFT description of strings propagating in the black hole geometry arises as an effective field theory.

  15. 5D black holes and matrix strings

    Energy Technology Data Exchange (ETDEWEB)

    Dijkgraaf, R. [Amsterdam Univ. (Netherlands). Dept. of Mathematics; Verlinde, E. [TH-Division, CERN, CH-1211 Geneva 23 (Switzerland)]|[Institute for Theoretical Physics, University of Utrecht, 3508 TA Utrecht (Netherlands); Verlinde, H. [Institute for Theoretical Physics, University of Amsterdam, 1018 XE Amsterdam (Netherlands)

    1997-11-24

    We derive the world-volume theory, the (non)-extremal entropy and background geometry of black holes and black strings constructed out of the NS IIA 5-brane within the framework of matrix theory. The CFT description of strings propagating in the black hole geometry arises as an effective field theory. (orig.). 38 refs.

  16. 5D black holes and matrix strings

    Science.gov (United States)

    Dijkgraaf, Robbert; Verlinde, Erik; Verlinde, Herman

    1997-02-01

    We derive the world-volume theory, the (non)-extremal entropy and background geometry of black holes and black strings constructed out of the NS IIA 5-brane within the framework of matrix theory. The CFT description of strings propagating in the black hole geometry arises as an effective field theory.

  17. Non-Hermitian Euclidean random matrix theory.

    Science.gov (United States)

    Goetschy, A; Skipetrov, S E

    2011-07-01

    We develop a theory for the eigenvalue density of arbitrary non-Hermitian Euclidean matrices. Closed equations for the resolvent and the eigenvector correlator are derived. The theory is applied to the random Green's matrix relevant to wave propagation in an ensemble of pointlike scattering centers. This opens a new perspective in the study of wave diffusion, Anderson localization, and random lasing.

  18. Intelligent fault diagnosis method for rolling bearings based on EMD and MLEM2%基于EMD和MLEM2的滚动轴承智能故障诊断方法

    Institute of Scientific and Technical Information of China (English)

    窦东阳; 杨建国; 李丽娟; 赵英凯

    2011-01-01

    To solve the problems of automatic fault diagnosis of rotating machinery, an intelligent method based on EMD and MLEM2 was presented. EMD was used to preprocess the original vibration signal, after that, six time-domain characteristic indices and five frequency-domain indices were calculated on the most appropriate IMF to form the dimensionless fault eigenvector of rolling bearings. According to the characteristic vector, fault decision table could be acquired by the data collected from the running machine. The MLEM2 algorithm was then applied to mine diagnostic rules from the data table. By these rules and an improved rule matching strategy, the final fault classification was carried out. EMD could discover the fault essence of the signal, and enhance the signal-to-noise rate of the selected IMF, while MLEM2 algorithm could be operated without attribute discretization, so the result rules were more complete and accurate. It was proved by the experiment of SKF6203 rolling bearings that the accuracy of this method reached 93.75%.It works like an expert system with the ability of acquiring knowledge itself, and does not need any artificial interference once the initialization is made. It is a valid method for intelligent fault diagnosis of rolling bearings.%针对旋转机械的自主故障诊断,提出一种基于EMD和MLEM2的智能解决方法.利用EMD预处理振动信号,在最适合的IMF分量上提取6个时域指标和5个频域指标构成无量纲的轴承故障特征向量.根据设备运行数据形成决策表,使用改进的MLEM2算法挖掘诊断规则,再结合改进的规则匹配策略进行状态识别.EMD能够剥离故障最本质的信息,提高所选分量的信噪比,而MLEM2算法无需对连续属性事先离散化,获得的诊断规则更完备、准确.SKF6203轴承试验表明,该方法诊断精度达到93.75%,相当于能够自主获取知识的专家系统,且只要一次初始设定,无需后续人工干预,是一种有效的智能诊断方法.

  19. 基于EMD-PCA-LSSVM方法的滚动轴承安全域估计和状态辨识%Safety region estimation and state identification of rolling bearings based on LMD-PCA-LSSVM method

    Institute of Scientific and Technical Information of China (English)

    张媛; 秦勇; 邢宗义; 贾利民; 廖贵玲

    2013-01-01

    将安全域的思想引入滚动轴承的状态监测中,综合利用经验模式分解(EMD)、主成分分析(PCA)和最小二乘支持向量机(LSSVM),进行了滚动轴承运行状态的安全域估计以及正常和各种故障状态的辨识.首先,按一定的时间间隔将采集的振动数据分段,每段数据进行EMD后获得各本征模函数(IMF)分量;其次,基于各段数据的本征模函数分量,利用主成分分析方法提取出每段数据的T2统计量和平方预估误差(SPE)统计量控制限值作为滚动轴承的状态特征量;最后,利用二分类的LSSVM进行滚动轴承运行状态的安全域估计,利用多分类的LSSVM进行滚动轴承的正常以及滚动体故障、内圈故障、外圈故障四种状态的辨识.试验结果显示安全域估计准确率和多种状态辨识正确率均大于95%,验证了上述方法的有效性.%The idea of safety region was introduced into the condition monitoring of rolling bearings,and the research on estimation of a rolling bearing' s safe operating region and identification of a rolling bearing' s operating state (normal or at fault) was performed by combinative use of empirical mode decomposition (EMD),principal component analysis (PCA) and least square support vector machine (LSSVM).Firstly,the vibration data of a rolling bearing was collected and it was segmented at regular intervals,and intrinsic mode functions (IMFs) of each segment' s data were obtained by using EMD.Then two statistical variables' control limits as the state characteristics of the rolling bearing were calculated based on PCA.At last,the boundary of the safety region was estimated by a twoclassification LSSVM,and the normal condition and three fault conditions were identified by a multi-classification LSSVM.The experimental results indicated that the accuracy of safety region estimation and that of state identification were both more than 95 %,so the effectiveness of the above method was verified.

  20. Patience of matrix games

    DEFF Research Database (Denmark)

    Hansen, Kristoffer Arnsfelt; Ibsen-Jensen, Rasmus; Podolskii, Vladimir V.;

    2013-01-01

    For matrix games we study how small nonzero probability must be used in optimal strategies. We show that for image win–lose–draw games (i.e. image matrix games) nonzero probabilities smaller than image are never needed. We also construct an explicit image win–lose game such that the unique optimal...

  1. Patience of matrix games

    DEFF Research Database (Denmark)

    Hansen, Kristoffer Arnsfelt; Ibsen-Jensen, Rasmus; Podolskii, Vladimir V.

    2013-01-01

    For matrix games we study how small nonzero probability must be used in optimal strategies. We show that for image win–lose–draw games (i.e. image matrix games) nonzero probabilities smaller than image are never needed. We also construct an explicit image win–lose game such that the unique optimal...

  2. Transfer function matrix

    Science.gov (United States)

    Seraji, H.

    1987-01-01

    Given a multivariable system, it is proved that the numerator matrix N(s) of the transfer function evaluated at any system pole either has unity rank or is a null matrix. It is also shown that N(s) evaluated at any transmission zero of the system has rank deficiency. Examples are given for illustration.

  3. A novel assay for extracellular matrix remodeling associated with liver fibrosis

    DEFF Research Database (Denmark)

    Barascuk, N; Veidal, S S; Larsen, L

    2010-01-01

    Accumulation of extracellular matrix (ECM) components and increased matrix-metalloprotease (MMPs) activity are hallmarks of fibrosis. We developed an ELISA for quantification of MMP-9 derived collagen type III (CO3) degradation....

  4. Study on Sleep Stages Based on EMD and Sample Entropy of EEG Rhythm%基于EMD和样本熵的脑电信号睡眠分期研究

    Institute of Scientific and Technical Information of China (English)

    李怀胜; 杨芳; 钟清华

    2016-01-01

    对于睡眠脑电的人工分期仍有不足的问题,提出一种基于脑电节律经验模态分解和样本熵结合的睡眠分期方法。首先利用经验模态分解对睡眠脑电信号进行去噪和基本节律提取,获得针对不同睡眠状态下脑电节律的样本熵,通过统计其样本熵均值,发现脑电节律δ波和θ波于不同睡眠状态下,样本熵均值不相等且方差较小,能有效表示不同睡眠阶段的特征,说明样本熵方法能较好的实现脑电信号的特征提取,用来区分睡眠各分期,为利用睡眠进行监护与医学治疗提供了一种可行的方法。%A method of sleep stages,based on EMD and sample entropy of EEG rhythm,is put forward to solve the shortage of artificial staging of sleep EEG.Firstly,EMD is used to denoise sleeping EEG and extract the basic rhythm.Secondly,the sample entropy of EEG rhythm under different sleep states is computed.Finally,after the statistics of mean and variance of the sample entropy,the mean of sample entropy of wave δand wave θis different under different sleeping stages of EEG rhythm,which indicates that the sample entropy analysis of sleep EEG rhythm can be used to effectively characterize different sleeping stages and extract feature of EEG.It provides a new way to make use of sleeping EEG for care and treatment.

  5. Dirac matrices as elements of a superalgebraic matrix algebra

    Science.gov (United States)

    Monakhov, V. V.

    2016-08-01

    The paper considers a Clifford extension of the Grassmann algebra, in which operators are built from Grassmann variables and by the derivatives with respect to them. It is shown that a subalgebra which is isomorphic to the usual matrix algebra exists in this algebra, the Clifford exten-sion of the Grassmann algebra is a generalization of the matrix algebra and contains superalgebraic operators expanding matrix algebra and produces supersymmetric transformations.

  6. One-Step Catalytic Synthesis of CuO/Cu2O in a Graphitized Porous C Matrix Derived from the Cu-Based Metal-Organic Framework for Li- and Na-Ion Batteries.

    Science.gov (United States)

    Kim, A-Young; Kim, Min Kyu; Cho, Keumnam; Woo, Jae-Young; Lee, Yongho; Han, Sung-Hwan; Byun, Dongjin; Choi, Wonchang; Lee, Joong Kee

    2016-08-03

    The hybrid composite electrode comprising CuO and Cu2O micronanoparticles in a highly graphitized porous C matrix (CuO/Cu2O-GPC) has a rational design and is a favorable approach to increasing the rate capability and reversible capacity of metal oxide negative materials for Li- and Na-ion batteries. CuO/Cu2O-GPC is synthesized through a Cu-based metal-organic framework via a one-step thermal transformation process. The electrochemical performances of the CuO/Cu2O-GPC negative electrode in Li- and Na-ion batteries are systematically studied and exhibit excellent capacities of 887.3 mAh g(-1) at 60 mA g(-1) after 200 cycles in a Li-ion battery and 302.9 mAh g(-1) at 50 mA g(-1) after 200 cycles in a Na-ion battery. The high electrochemical stability was obtained via the rational strategy, mainly owing to the synergy effect of the CuO and Cu2O micronanoparticles and highly graphitized porous C formed by catalytic graphitization of Cu nanoparticles. Owing to the simple one-step thermal transformation process and resulting high electrochemical performance, CuO/Cu2O-GPC is one of the prospective negative active materials for rechargeable Li- and Na-ion batteries.

  7. Improved Matrix Uncertainty Selector

    CERN Document Server

    Rosenbaum, Mathieu

    2011-01-01

    We consider the regression model with observation error in the design: y=X\\theta* + e, Z=X+N. Here the random vector y in R^n and the random n*p matrix Z are observed, the n*p matrix X is unknown, N is an n*p random noise matrix, e in R^n is a random noise vector, and \\theta* is a vector of unknown parameters to be estimated. We consider the setting where the dimension p can be much larger than the sample size n and \\theta* is sparse. Because of the presence of the noise matrix N, the commonly used Lasso and Dantzig selector are unstable. An alternative procedure called the Matrix Uncertainty (MU) selector has been proposed in Rosenbaum and Tsybakov (2010) in order to account for the noise. The properties of the MU selector have been studied in Rosenbaum and Tsybakov (2010) for sparse \\theta* under the assumption that the noise matrix N is deterministic and its values are small. In this paper, we propose a modification of the MU selector when N is a random matrix with zero-mean entries having the variances th...

  8. Matrix Representation of Symmetry Operators in Elementary Crystallography

    Science.gov (United States)

    Cody, R. D.

    1972-01-01

    Presents the derivation of rotation and reflection matrix representation of symmetry operators as used in the initial discussion of crystal symmetry in elementary mineralogy at Iowa State University. Includes references and an appended list of matrix representations of the important crystallographic symmetry operators, excluding the trigonal and…

  9. A New Test for a Normal Covariance Matrix

    Institute of Scientific and Technical Information of China (English)

    禹建奇

    2015-01-01

    The problem of testing the normal covariance matrix equal to a specified matrix is considered.A new Chi-Square test statistic is derived for multivariate normal population.Unlike the likelihood ratio test,the new test is an exact one.

  10. The matrix reloaded: the evolution of regenerative hydrogels

    Directory of Open Access Journals (Sweden)

    Esmaiel Jabbari

    2016-05-01

    Full Text Available Cell-laden hydrogels can regenerate lost, damaged or malfunctioning tissues. Clinical success of such hydrogels is strongly dependent on the ability to tune their chemical, physico-mechanical, and biological properties to a specific application. In particular, mimicking the intricate arrangement of cell-interactive ligands of natural tissues is crucial to proper tissue function. Natural extracellular matrix elements represent a unique source for generating such interactions. A plethora of extracellular matrix-based approaches have been explored to augment the regenerative potential of hydrogels. These efforts include the development of matrix-like hydrogels, hydrogels containing matrix-like molecules, hydrogels containing decellularized matrix, hydrogels derived from decellularized matrix, and decellularized tissues as reimplantable matrix hydrogels. Here we review the evolution, strengths and weaknesses of these developments from the perspective of creating tissue regenerating hydrogels.

  11. Elementary matrix theory

    CERN Document Server

    Eves, Howard

    1980-01-01

    The usefulness of matrix theory as a tool in disciplines ranging from quantum mechanics to psychometrics is widely recognized, and courses in matrix theory are increasingly a standard part of the undergraduate curriculum.This outstanding text offers an unusual introduction to matrix theory at the undergraduate level. Unlike most texts dealing with the topic, which tend to remain on an abstract level, Dr. Eves' book employs a concrete elementary approach, avoiding abstraction until the final chapter. This practical method renders the text especially accessible to students of physics, engineeri

  12. Rheocasting Al matrix composites

    Energy Technology Data Exchange (ETDEWEB)

    Girot, F.A.; Albingre, L.; Quenisset, J.M.; Naslain, R.

    1987-11-01

    A development status account is given for the rheocasting method of Al-alloy matrix/SiC-whisker composites, which involves the incorporation and homogeneous distribution of 8-15 vol pct of whiskers through the stirring of the semisolid matrix melt while retaining sufficient fluidity for casting. Both 1-, 3-, and 6-mm fibers of Nicalon SiC and and SiC whisker reinforcements have been experimentally investigated, with attention to the characterization of the resulting microstructures and the effects of fiber-matrix interactions. A thin silica layer is found at the whisker surface. 7 references.

  13. Mueller matrix differential decomposition.

    Science.gov (United States)

    Ortega-Quijano, Noé; Arce-Diego, José Luis

    2011-05-15

    We present a Mueller matrix decomposition based on the differential formulation of the Mueller calculus. The differential Mueller matrix is obtained from the macroscopic matrix through an eigenanalysis. It is subsequently resolved into the complete set of 16 differential matrices that correspond to the basic types of optical behavior for depolarizing anisotropic media. The method is successfully applied to the polarimetric analysis of several samples. The differential parameters enable one to perform an exhaustive characterization of anisotropy and depolarization. This decomposition is particularly appropriate for studying media in which several polarization effects take place simultaneously. © 2011 Optical Society of America

  14. Construction of the exact Fisher information matrix of Gaussian time series models by means of matrix differential rules

    NARCIS (Netherlands)

    Klein, A.A.B.; Melard, G.; Zahaf, T.

    2000-01-01

    The Fisher information matrix is of fundamental importance for the analysis of parameter estimation of time series models. In this paper the exact information matrix of a multivariate Gaussian time series model expressed in state space form is derived. A computationally efficient procedure is used b

  15. Construction of the exact Fisher information matrix of Gaussian time series models by means of matrix differential rules

    NARCIS (Netherlands)

    Klein, A.A.B.; Melard, G.; Zahaf, T.

    2000-01-01

    The Fisher information matrix is of fundamental importance for the analysis of parameter estimation of time series models. In this paper the exact information matrix of a multivariate Gaussian time series model expressed in state space form is derived. A computationally efficient procedure is used b

  16. 汽轮机转子故障诊断中LMD法和EMD法的性能对比研究%Performance Contrast Between LMD and EMD in Fault Diagnosis of Turbine Rotors

    Institute of Scientific and Technical Information of China (English)

    向玲; 鄢小安

    2014-01-01

    针对仿真信号和实验转子故障信号,对局部均值分解(LMD)法和经验模态分解(EMD)法的性能进行了对比研究,提出端点效应的评价指标和基于LMD法的转子不平衡、转子碰摩和转子油膜涡动的故障诊断方法,对基于EMD法和基于LMD法的信号分解结果进行对比分析.结果表明:LMD法分解转子振动信号时的模态混叠现象较EMD法分解时的模态混叠现象不明显;LMD法抑制端点效应的能力强于EMD法;LMD法的诊断结果更精确,能有效应用于汽轮机转子故障诊断中.

  17. Research of the CRH5 Cardan Shaft Roll Frequency Energy by EMD Method%基于EMD的CRH5动车组万向轴转频能量研究

    Institute of Scientific and Technical Information of China (English)

    阮腾达; 林建辉

    2014-01-01

    通过监测CRH5动车组齿轮箱振动,计算万向轴特征频率能量对评估万向轴状态具有现实意义。本文简述了经验模态分解(EMD)的基本方法,对实测200km/h下齿轮箱振动信号进行EMD分解,提取万向轴特征频率成分,并计算其能量。研究结果标明该方法可以有效对万向轴动不平衡进行评估。%Calculate CRH5 cardan characteristic frequency energy by monitoring the vibration of gearbox is meaningful to assess the state of the cardan shaft .This paper described the EMD method used to decompose the signal of gearbox vibration when the speed of train is 200km/h, extract characteristic frequency of the cardan shaft and calculate the energy .Research results show this method can evaluate the unbalance of cardan shaft ef-fectively.

  18. A Phishing Web Pages Detection Algorithm Based on Nested Structure of Earth Mover's Distance (Nested-EMD)%基于嵌套EMD的钓鱼网页检测算法

    Institute of Scientific and Technical Information of China (English)

    曹玖新; 毛波; 罗军舟; 刘波

    2009-01-01

    网络钓鱼(Web phishing)以相似网站欺诈用户、骗取个人机密信息,已成为电子金融活动的重大威胁.对此,文中提出了一个钓鱼网页检测架构.在具体检测机制方面,提出了一个基于嵌套EMD(Nested Earth Mover's Distance)的网页相似度判定算法,对Web图像进行分割,抽取子图特征并构建网页的ARG (Attributed Relational Graph),在计算不同ARG属性距离的基础上,采用嵌套EMD方法计算网页的相似度,实现了对钓鱼网站的检测.实验结果表明,与国际现有研究成果相比,该算法具有较高的精度和较强的适应性.

  19. Application of Recurrence Plot Analysis Method to Fault Diagnosis Based on EMD%基于EMD降噪的递归图分析方法在齿轮故障诊断中的应用

    Institute of Scientific and Technical Information of China (English)

    蒲晓川; 肖涵

    2015-01-01

    为从齿轮振动信号中提取包含故障信息的特征量,提出了一种基于经验模态分解(EMD)降噪的递归图分析方法.该方法用EMD方法将振动信号分解为有限个固有模式函数(IMF)分量,选取包含故障信息的IMF分量建立递归图,从递归图中提取特征向量,运用高斯混合模型进行模式识别.将该方法运用于故障齿轮振动信号的识别,结果表明该方法具有较高的识别率,对齿轮故障能够有效地进行分类与诊断.

  20. 基于EMD和Hilbert变换的脑磁信号特征提取和分类%Feature extraction and classification of magnetoencephalography based on EMD and Hilbert transform

    Institute of Scientific and Technical Information of China (English)

    王健锋; 黄晓霞

    2014-01-01

    为研究通过脑机接口(Brain-Computer Interface,BCI)处理非线性、非稳定性信号问题,针对基于脑磁信号(magnetoencephalography,MEG)的BCI,提出一种基于经验模式分解(Empirical Mode Decomposition,EMD)和Hilbert变换的MEG特征提取和分类方法.该方法首先对MEG数据进行预处理;其次用EMD和Hilbert变换方法提取特征向量;然后用主成分分析法对提取到的特征向量进行降维处理;最后把处理过的特征向量作为支持向量机(Support Vector Machine,SVM)的一个输入向量实现MEG的分类.使用该方法对第4届国际BCI竞赛提供的MEG数据进行分类,实验结果表明可以获得较高的分类准确率.

  1. 基于EMD和Elman网络的人民币汇率时间序列预测%Research on the Forecasting of RMB Exchange Rate Time Series Based on EMD and Elman Network

    Institute of Scientific and Technical Information of China (English)

    谢赤; 郑林林; 孙柏; 张在美

    2009-01-01

    为了改进神经网络的预测性能,更精确地预测人民币汇率,提出一种新的汇率时间序列预测方法,即利用基于经验模态分解(EMD)的Elman网络进行预测.首先对人民币兑美元的汇率序列做了非线性检验和非平稳性检验,然后对该序列进行经验模态分解,将得到的固有模态函数作为神经网络的输入变量,并在确定神经网络的关键参数后进行预测.实证结果表明,利用基于EMD的Elman网络进行人民币汇率预测能够取得更好的效果.

  2. One New Scheme to Discriminate Inrush Current from Internal Fault of Power Transformer Based on EMD Decomposition%基于EMD分解的变压器励磁涌流鉴别

    Institute of Scientific and Technical Information of China (English)

    罗伟强; 边铁

    2009-01-01

    针对励磁涌流波形畸变严重且会出现尖顶波,而故障电流基本保持基频正弦波特征的特点,提出了一种利用HHT(Hilbert-Huang Transform)的EMD(Empirical Mode Decomposition)分解来识别变压器励磁涌流的新方法.该方法利用EMD将数据分解成有限个IMF(Intrinsic Mode Function),定义并计算各个IMF在X轴上的投影面积Sc、Simf的比重系数Kc及其最大值Kmax.在比较励磁涌流和故障电流Kmax不同特点的基础上,提出了一种变压器保护新方案.理论分析及动模实验结果表明,该方法能够正确区分励磁涌流及故障电流,其判断时间约20ms;方法实现方便,不受非周期分量等影响.

  3. Baecklund transformations for a matrix second Painleve equation

    Energy Technology Data Exchange (ETDEWEB)

    Gordoa, P.R. [Departamento de Matematica Aplicada, ESCET, Universidad Rey Juan Carlos, C/ Tulipan s/n, 28933 Mostoles, Madrid (Spain); Pickering, A., E-mail: andrew.pickering@urjc.e [Departamento de Matematica Aplicada, ESCET, Universidad Rey Juan Carlos, C/ Tulipan s/n, 28933 Mostoles, Madrid (Spain); Zhu, Z.N. [Department of Mathematics, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240 (China)

    2010-07-26

    Higher-order Painleve equations are a topic of much current interest. Here we are interested in deriving auto-Baecklund transformations for one particular kind of higher-order Painleve equation, namely, a matrix Painleve equation. The extension of a recently derived approach to deal with the matrix second Painleve equation considered here represents a further demonstration of that approach's efficacy.

  4. Pesticide-Exposure Matrix

    Science.gov (United States)

    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.

  5. Matrix comparison, Part 2

    DEFF Research Database (Denmark)

    Schneider, Jesper Wiborg; Borlund, Pia

    2007-01-01

    The present two-part article introduces matrix comparison as a formal means for evaluation purposes in informetric studies such as cocitation analysis. In the first part, the motivation behind introducing matrix comparison to informetric studies, as well as two important issues influencing...... such comparisons, matrix generation, and the composition of proximity measures, are introduced and discussed. In this second part, the authors introduce and thoroughly demonstrate two related matrix comparison techniques the Mantel test and Procrustes analysis, respectively. These techniques can compare...... important. Alternatively, or as a supplement, Procrustes analysis compares the actual ordination results without investigating the underlying proximity measures, by matching two configurations of the same objects in a multidimensional space. An advantage of the Procrustes analysis though, is the graphical...

  6. The Matrix Organization Revisited

    DEFF Research Database (Denmark)

    Gattiker, Urs E.; Ulhøi, John Parm

    1999-01-01

    This paper gives a short overview of matrix structure and technology management. It outlines some of the characteristics and also points out that many organizations may actualy be hybrids (i.e. mix several ways of organizing to allocate resorces effectively).......This paper gives a short overview of matrix structure and technology management. It outlines some of the characteristics and also points out that many organizations may actualy be hybrids (i.e. mix several ways of organizing to allocate resorces effectively)....

  7. Optical Coherency Matrix Tomography

    Science.gov (United States)

    2015-10-19

    optics has been studied theoretically11, but has not been demonstrated experimentally heretofore. Even in the simplest case of two binary DoFs6 (e.g...coherency matrix G spanning these DoFs. This optical coherency matrix has not been measured in its entirety to date—even in the simplest case of two...dense coding, etc. CREOL, The College of Optics & Photonics, University of Central Florida, Orlando , Florida 32816, USA. Correspondence and requests

  8. Matrix fractional systems

    Science.gov (United States)

    Tenreiro Machado, J. A.

    2015-08-01

    This paper addresses the matrix representation of dynamical systems in the perspective of fractional calculus. Fractional elements and fractional systems are interpreted under the light of the classical Cole-Cole, Davidson-Cole, and Havriliak-Negami heuristic models. Numerical simulations for an electrical circuit enlighten the results for matrix based models and high fractional orders. The conclusions clarify the distinction between fractional elements and fractional systems.

  9. Hacking the Matrix.

    Science.gov (United States)

    Czerwinski, Michael; Spence, Jason R

    2017-01-05

    Recently in Nature, Gjorevski et al. (2016) describe a fully defined synthetic hydrogel that mimics the extracellular matrix to support in vitro growth of intestinal stem cells and organoids. The hydrogel allows exquisite control over the chemical and physical in vitro niche and enables identification of regulatory properties of the matrix. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. The Matrix Organization Revisited

    DEFF Research Database (Denmark)

    Gattiker, Urs E.; Ulhøi, John Parm

    1999-01-01

    This paper gives a short overview of matrix structure and technology management. It outlines some of the characteristics and also points out that many organizations may actualy be hybrids (i.e. mix several ways of organizing to allocate resorces effectively).......This paper gives a short overview of matrix structure and technology management. It outlines some of the characteristics and also points out that many organizations may actualy be hybrids (i.e. mix several ways of organizing to allocate resorces effectively)....

  11. Follow-up: Prospective compound design using the ‘SAR Matrix’ method and matrix-derived conditional probabilities of activity [v1; ref status: indexed, http://f1000r.es/56v

    Directory of Open Access Journals (Sweden)

    Disha Gupta-Ostermann

    2015-03-01

    Full Text Available 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.

  12. Follow-up: Prospective compound design using the ‘SAR Matrix’ method and matrix-derived conditional probabilities of activity [v2; ref status: indexed, http://f1000r.es/59v

    Directory of Open Access Journals (Sweden)

    Disha Gupta-Ostermann

    2015-04-01

    Full Text Available 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.

  13. Study of compatibility of acellular cartilage extracellular matrix-derived porous scaffolds with sheep nucleus pulposus cells%软骨脱细胞细胞外基质多孔支架与山羊髓核细胞生物相容性研究

    Institute of Scientific and Technical Information of China (English)

    伍耀宏; 徐宝山; 杨强; 李秀兰; 张杨; 夏群; 张春秋; 许海委

    2013-01-01

    Objective To study the compatibility of acellular cartilage extracellular matrix-derived porous scaffolds with sheep nucleus pulposus cells.Methods Articular cartilage derived from pigs was physically shattered and decellularized,and then made into porous scaffolds with freeze-drying techniques.Nucleus pulposus cells were isolated from the goat lumbar intervertebral disc,and P1 generation were obtained after culturing.The toxicity of leaching liquor from scaffolds was tested by MTT assay.The cells were seeded onto scaffolds with a density of 5 x 106/ml and cultured for 48h in vitro,activity and adhesion for cells on scaffolds were evaluated by inverted microscope,HE staining,LIVE/DEAD staining and scanning electron microscopy.Results Acellular cartilage extracellular matrix-derived porous scaffolds were smooth and transparent,isolated nucleus pulposus cells showed typical chondrocyte-like morphology.MTT assay demonstrated that proliferation among the groups has no significant difference(P>0.05).Cells showed spherical or short-spindle morphology and attached to the scaffolds evenly under the inverted microscope and scanning electron microscopy,and HE staining confirmed the even attachment of the cells.All the cells showed green fluorescence (live cells) while no red fluorescence (dead cells) was observed after staining with LIVE/DEAD dye.Conclusion The acellular cartilage extracellular matrix-derived porous scaffolds can be used as the nucleus pulposus tissue for sharing similar extracellular matrix composition with nucleus pulposus tissue and possess good cell compatibility with the sheep nucleus pulposus cells.%目的 制备软骨脱细胞细胞外基质多孔支架,并探讨其与山羊髓核细胞的生物相容性.方法 猪关节软骨经研磨、脱细胞、冷冻干燥技术等处理制成三维多孔支架;从山羊腰椎间盘中分离出髓核细胞,培养后获取P1代细胞;四甲基偶氮唑蓝(MTT)检测支架浸提

  14. Fluctuations of Matrix Entries of Regular Functions of Wigner Matrices

    CERN Document Server

    Pizzo, Alessandro; Soshnikov, Alexander

    2011-01-01

    We study the fluctuations of the matrix entries of regular functions of Wigner random matrices in the limit when the matrix size goes to infinity. In the case of the Gaussian ensembles (GOE and GUE) this problem was considered by A.Lytova and L.Pastur in J. Stat. Phys., v.134, 147-159 (2009). Our results are valid provided the off-diagonal matrix entries have finite fourth moment, the diagonal matrix entries have finite third moment, and the test functions have four continuous derivatives in a neighborhood of the support of the Wigner semicircle law.

  15. Quantum Mechanical Time-Delay Matrix in Chaotic Scattering

    Energy Technology Data Exchange (ETDEWEB)

    Brouwer, P.W.; Frahm, K.M.; Beenakker, C.W. [Instituut-Lorentz, Leiden University, P.O. Box 9506, 2300 RA Leiden (The Netherlands)

    1997-06-01

    We calculate the probability distribution of the matrix Q=-i{h_bar}S{sup -1}{partial_derivative}S/{partial_derivative}E for a chaotic system with scattering matrix S at energy E . The eigenvalues {tau}{sub j} of Q are the so-called proper delay times, introduced by Wigner and Smith to describe the time dependence of a scattering process. The distribution of the inverse delay times turns out to be given by the Laguerre ensemble from random-matrix theory. {copyright} {ital 1997} {ital The American Physical Society}

  16. 双氧水-氢氧化钠结合对脱细胞猪真皮基质材料高度纯化的作用%Effects of H2 O2-NaOH on highly-purification of porcine-derived acellular dermal matrix

    Institute of Scientific and Technical Information of China (English)

    肖世维; 但年华; 但卫华

    2015-01-01

    Using traceable pigskin as raw material,by observing the change of thickness,area,collagen content, non-collagen content in effluent and the histological morphology,the optimum alkali swelling scheme,H 2 O 2 4%-NaOH 6%,of preparing acellular dermal matrix has been harvested.After the preparation of highly-puri-fied porcine-derived acellular dermal matrix,a series of tests have been carried out.The tensile strength of the material was 7.2 MPa.It has good water absorption ability and no heavy metal.Animal experiments demonstra-ted no obvious acute peroral toxicity and the cytotoxicity was only 1 grade.These results lay the foundation for the application of the highly-purified porcine-derived acellular dermal matrix in biomedical materials area in the future with further research.%以可溯源性猪皮为原料,采用特殊的化学、物理及生化方法对猪皮进行高度纯化处理,通过观察实验中皮块厚度、面积、废液中胶原蛋白与非胶原蛋白含量及组织学形貌变化,得出脱细胞猪真皮基质碱膨胀的最佳方案为双氧水4%-氢氧化钠6%.并制备了高纯度脱细胞猪真皮基质,检测其抗张强度为7.2 MPa,吸湿性能好,不含重金属,无经口急毒,细胞除去干净且细胞毒性1级,为今后脱细胞猪真皮基质在生物医用材料领域的应用奠定基础.

  17. Matrix Information Geometry

    CERN Document Server

    Bhatia, Rajendra

    2013-01-01

    This book is an outcome of the Indo-French Workshop on Matrix Information Geometries (MIG): Applications in Sensor and Cognitive Systems Engineering, which was held in Ecole Polytechnique and Thales Research and Technology Center, Palaiseau, France, in February 23-25, 2011. The workshop was generously funded by the Indo-French Centre for the Promotion of Advanced Research (IFCPAR).  During the event, 22 renowned invited french or indian speakers gave lectures on their areas of expertise within the field of matrix analysis or processing. From these talks, a total of 17 original contribution or state-of-the-art chapters have been assembled in this volume. All articles were thoroughly peer-reviewed and improved, according to the suggestions of the international referees. The 17 contributions presented  are organized in three parts: (1) State-of-the-art surveys & original matrix theory work, (2) Advanced matrix theory for radar processing, and (3) Matrix-based signal processing applications.  

  18. Algorithm for deriving explicitly the analytical expression of geometric stiffness matrix of the 4-node,24 degrees of f reedom flat shell element%四节点二十四自由度平板壳单元几何刚度矩阵显式解析式的推演算法研究

    Institute of Scientific and Technical Information of China (English)

    文颖; 曾庆元

    2013-01-01

    几何刚度矩阵的推演是结构几何非线性有限元分析的重点和难点之一。推导几何刚度矩阵显式解析表达式成为简化非线性有限元列式,提高分析效率的关键。本文在协同转动法框架下,基于刚体运动法则对四节点二十四自由度的平板壳单元几何刚度矩阵显式解析式进行了推导和讨论;分析了悬臂梁大转动、不同壁厚条件下简支圆柱形屋顶空间大变位两个经典算例。研究结果表明:(1)几何刚度矩阵的显式计算公式不仅为板壳结构几何非线性列式提供了方便而且具有良好的精度;(2)推导的几何刚度矩阵适用于各类型四边形二十四自由度平板壳单元模型;(3)与数值积分相比,采用解析形式的几何刚度矩阵可以显著提高非线性响应计算效率。%The derivation of geometric stiffness matrix is an essential and difficult stage in conducting the finite element analysis of geometrically nonlinear structural problems .Any attempt to obtaining explicit-ly the analytical expression of geometric stiffness matrix is of great importance for simplifying the for-mulation ,and in particular for improving efficiency and effectiveness of the overall procedure .In the con-text of co-rotational formulation ,an algorithm analytically leading to the geometric stiffness matrix of the 4-node quadrilateral flat shell element with a total of 24 degrees of freedom was presented based on the rigid body motion rule and consecutively subject to discussion .Two benchmark problems ,namely the large rotation problem of a cantilever beam and the large deflection behaviour of a hinged semi-cylindrical roof with two typical thicknesses subjected to a central pinching force ,were analyzed for demonstrating the reliability and robustness of the proposed procedure .The results of numerical study reveal that :(1) The explicit formula derived herein provides a great deal of convenience while

  19. Global unitary fixing and matrix-valued correlations in matrix models

    CERN Document Server

    Adler, S L; Horwitz, Lawrence P.

    2003-01-01

    We consider the partition function for a matrix model with a global unitary invariant energy function. We show that the averages over the partition function of global unitary invariant trace polynomials of the matrix variables are the same when calculated with any choice of a global unitary fixing, while averages of such polynomials without a trace define matrix-valued correlation functions, that depend on the choice of unitary fixing. The unitary fixing is formulated within the standard Faddeev-Popov framework, in which the squared Vandermonde determinant emerges as a factor of the complete Faddeev-Popov determinant. We give the ghost representation for the FP determinant, and the corresponding BRST invariance of the unitary-fixed partition function. The formalism is relevant for deriving Ward identities obeyed by matrix-valued correlation functions.

  20. Dentin matrix degradation by host Matrix Metalloproteinases: inhibition and clinical perspectives towards regeneration.

    Directory of Open Access Journals (Sweden)

    Catherine eChaussain

    2013-11-01

    Full Text Available Bacterial enzymes have long been considered solely accountable for the degradation of the dentin matrix during the carious process. However, the emerging literature suggests that host-derived enzymes, and in particular the matrix metalloproteinases (MMPs contained in dentin and saliva can play a major role in this process by their ability to degrade the dentin matrix from within. These findings are important since they open new therapeutic options for caries prevention and treatment. The possibility of using MMP inhibitors to interfere with dentin caries progression is discussed. Furthermore, the potential release of bioactive peptides by the enzymatic cleavage of dentin matrix proteins by MMPs during the carious process is discussed. These peptides, once identified, may constitute promising therapeutical tools for tooth and bone regeneration.

  1. Determining a 'safe' high-mass limit in matrix-assisted laser desorption/ionisation time-of-flight mass spectra of coal derived materials with reference to instrument noise

    Science.gov (United States)

    Lazaro; Herod; Domin; Zhuo; Islas; Kandiyoti

    1999-01-01

    Three methods for determining a 'safe' estimate for high-mass limits of MALDI spectra of coal derived liquids were explored, using a sample of coal-tar pitch and its pyridine-insoluble fraction. Co-addition of increasing numbers of single-shot spectra (10, 30, 50 and 100 pulses) showed visually observable reductions in noise levels, consistent with robust and statistically meaningful signals. Three separate types of post-acquisition calculation were used to identify high-mass limits of the spectra. (i) A literature method indicated high-mass limits similar to those observed visually-as a shift from baseline at the highest masses, nearly 350 000 u for the coal tar pitch and about 390 000 u for its pyridine insoluble fraction. (ii) Comparing instrument signal with pre-selected multiples of the standard deviation, upper mass estimates of between 40-60 000 u for the coal-tar pitch and about 95 000 u for its pyridine-insoluble fraction were found. (iii) Calculation of the slope was used to identify 'lift-off' of the spectrum from baseline. The angle between the smoothed spectrum and the baseline was matched to a pre-selected value (e.g. 0.5 degrees and 1 degrees ). However, the arbitrary specification of the key parameter did not establish this last method on a firm basis. The choice of a criterion for estimating high-mass limits of MALDI spectra remains a semi-quantitative procedure; a reasonably conservative high-mass limit may be estimated by comparison of signal with five times the standard deviation. However, evaluation of size exclusion chromatograms of the present samples using polystyrene standards suggests that molecular mass distributions of pitch samples arrived at by MALDI mass spectrometry are, at least partly, determined by the limitations of available instruments. Copyright 1999 John Wiley & Sons, Ltd.

  2. Ceramic Matrix Composites .

    Directory of Open Access Journals (Sweden)

    J. Mukerji

    1993-10-01

    Full Text Available The present state of the knowledge of ceramic-matrix composites have been reviewed. The fracture toughness of present structural ceramics are not enough to permit design of high performance machines with ceramic parts. They also fail by catastrophic brittle fracture. It is generally believed that further improvement of fracture toughness is only possible by making composites of ceramics with ceramic fibre, particulate or platelets. Only ceramic-matrix composites capable of working above 1000 degree centigrade has been dealt with keeping reinforced plastics and metal-reinforced ceramics outside the purview. The author has discussed the basic mechanisms of toughening and fabrication of composites and the difficulties involved. Properties of available fibres and whiskers have been given. The best results obtained so far have been indicated. The limitations of improvement in properties of ceramic-matrix composites have been discussed.

  3. Matrix interdiction problem

    Energy Technology Data Exchange (ETDEWEB)

    Pan, Feng [Los Alamos National Laboratory; Kasiviswanathan, Shiva [Los Alamos National Laboratory

    2010-01-01

    In the matrix interdiction problem, a real-valued matrix and an integer k is given. The objective is to remove k columns such that the sum over all rows of the maximum entry in each row is minimized. This combinatorial problem is closely related to bipartite network interdiction problem which can be applied to prioritize the border checkpoints in order to minimize the probability that an adversary can successfully cross the border. After introducing the matrix interdiction problem, we will prove the problem is NP-hard, and even NP-hard to approximate with an additive n{gamma} factor for a fixed constant {gamma}. We also present an algorithm for this problem that achieves a factor of (n-k) mUltiplicative approximation ratio.

  4. Extracellular matrix structure.

    Science.gov (United States)

    Theocharis, Achilleas D; Skandalis, Spyros S; Gialeli, Chrysostomi; Karamanos, Nikos K

    2016-02-01

    Extracellular matrix (ECM) is a non-cellular three-dimensional macromolecular network composed of collagens, proteoglycans/glycosaminoglycans, elastin, fibronectin, laminins, and several other glycoproteins. Matrix components bind each other as well as cell adhesion receptors forming a complex network into which cells reside in all tissues and organs. Cell surface receptors transduce signals into cells from ECM, which regulate diverse cellular functions, such as survival, growth, migration, and differentiation, and are vital for maintaining normal homeostasis. ECM is a highly dynamic structural network that continuously undergoes remodeling mediated by several matrix-degrading enzymes during normal and pathological conditions. Deregulation of ECM composition and structure is associated with the development and progression of several pathologic conditions. This article emphasizes in the complex ECM structure as to provide a better understanding of its dynamic structural and functional multipotency. Where relevant, the implication of the various families of ECM macromolecules in health and disease is also presented.

  5. Finite Temperature Matrix Theory

    CERN Document Server

    Meana, M L; Peñalba, J P; Meana, Marco Laucelli; Peñalba, Jesús Puente

    1998-01-01

    We present the way the Lorentz invariant canonical partition function for Matrix Theory as a light-cone formulation of M-theory can be computed. We explicitly show how when the eleventh dimension is decompactified, the N=1 eleven dimensional SUGRA partition function appears. From this particular analysis we also clarify the question about the discernibility problem when making statistics with supergravitons (the N! problem) in Matrix black hole configurations. We also provide a high temperature expansion which captures some structure of the canonical partition function when interactions amongst D-particles are on. The connection with the semi-classical computations thermalizing the open superstrings attached to a D-particle is also clarified through a Born-Oppenheimer approximation. Some ideas about how Matrix Theory would describe the complementary degrees of freedom of the massless content of eleven dimensional SUGRA are also discussed.

  6. Matrixed business support comparison study.

    Energy Technology Data Exchange (ETDEWEB)

    Parsons, Josh D.

    2004-11-01

    The Matrixed Business Support Comparison Study reviewed the current matrixed Chief Financial Officer (CFO) division staff models at Sandia National Laboratories. There were two primary drivers of this analysis: (1) the increasing number of financial staff matrixed to mission customers and (2) the desire to further understand the matrix process and the opportunities and challenges it creates.

  7. IIB Matrix Model

    CERN Document Server

    Aoki, H; Kawai, H; Kitazawa, Y; Tada, T; Tsuchiya, A

    1999-01-01

    We review our proposal for a constructive definition of superstring, type IIB matrix model. The IIB matrix model is a manifestly covariant model for space-time and matter which possesses N=2 supersymmetry in ten dimensions. We refine our arguments to reproduce string perturbation theory based on the loop equations. We emphasize that the space-time is dynamically determined from the eigenvalue distributions of the matrices. We also explain how matter, gauge fields and gravitation appear as fluctuations around dynamically determined space-time.

  8. Little IIB Matrix Model

    CERN Document Server

    Kitazawa, Y; Saito, O; Kitazawa, Yoshihisa; Mizoguchi, Shun'ya; Saito, Osamu

    2006-01-01

    We study the zero-dimensional reduced model of D=6 pure super Yang-Mills theory and argue that the large N limit describes the (2,0) Little String Theory. The one-loop effective action shows that the force exerted between two diagonal blocks of matrices behaves as 1/r^4, implying a six-dimensional spacetime. We also observe that it is due to non-gravitational interactions. We construct wave functions and vertex operators which realize the D=6, (2,0) tensor representation. We also comment on other "little" analogues of the IIB matrix model and Matrix Theory with less supercharges.

  9. Elementary matrix algebra

    CERN Document Server

    Hohn, Franz E

    2012-01-01

    This complete and coherent exposition, complemented by numerous illustrative examples, offers readers a text that can teach by itself. Fully rigorous in its treatment, it offers a mathematically sound sequencing of topics. The work starts with the most basic laws of matrix algebra and progresses to the sweep-out process for obtaining the complete solution of any given system of linear equations - homogeneous or nonhomogeneous - and the role of matrix algebra in the presentation of useful geometric ideas, techniques, and terminology.Other subjects include the complete treatment of the structur

  10. Rheocasting Al Matrix Composites

    Science.gov (United States)

    Girot, F. A.; Albingre, L.; Quenisset, J. M.; Naslain, R.

    1987-11-01

    Aluminum alloy matrix composites reinforced by SiC short fibers (or whiskers) can be prepared by rheocasting, a process which consists of the incorporation and homogeneous distribution of the reinforcement by stirring within a semi-solid alloy. Using this technique, composites containing fiber volume fractions in the range of 8-15%, have been obtained for various fibers lengths (i.e., 1 mm, 3 mm and 6 mm for SiC fibers). This paper attempts to delineate the best compocasting conditions for aluminum matrix composites reinforced by short SiC (e.g Nicalon) or SiC whiskers (e.g., Tokamax) and characterize the resulting microstructures.

  11. Reduced Google matrix

    CERN Document Server

    Frahm, K M

    2016-01-01

    Using parallels with the quantum scattering theory, developed for processes in nuclear and mesoscopic physics and quantum chaos, we construct a reduced Google matrix $G_R$ which describes the properties and interactions of a certain subset of selected nodes belonging to a much larger directed network. The matrix $G_R$ takes into account effective interactions between subset nodes by all their indirect links via the whole network. We argue that this approach gives new possibilities to analyze effective interactions in a group of nodes embedded in a large directed networks. Possible efficient numerical methods for the practical computation of $G_R$ are also described.

  12. Density matrix perturbation theory.

    Science.gov (United States)

    Niklasson, Anders M N; Challacombe, Matt

    2004-05-14

    An orbital-free quantum perturbation theory is proposed. It gives the response of the density matrix upon variation of the Hamiltonian by quadratically convergent recursions based on perturbed projections. The technique allows treatment of embedded quantum subsystems with a computational cost scaling linearly with the size of the perturbed region, O(N(pert.)), and as O(1) with the total system size. The method allows efficient high order perturbation expansions, as demonstrated with an example involving a 10th order expansion. Density matrix analogs of Wigner's 2n+1 rule are also presented.

  13. Complex matrix model duality

    Energy Technology Data Exchange (ETDEWEB)

    Brown, T.W.

    2010-11-15

    The same complex matrix model calculates both tachyon scattering for the c=1 non-critical string at the self-dual radius and certain correlation functions of half-BPS operators in N=4 super- Yang-Mills. It is dual to another complex matrix model where the couplings of the first model are encoded in the Kontsevich-like variables of the second. The duality between the theories is mirrored by the duality of their Feynman diagrams. Analogously to the Hermitian Kontsevich- Penner model, the correlation functions of the second model can be written as sums over discrete points in subspaces of the moduli space of punctured Riemann surfaces. (orig.)

  14. 基于改进的EMD的运城市持续极端气温的初步分析%Preliminary Analysis of Sustained Extreme Temperature Events in Yuncheng Using Improved EMD

    Institute of Scientific and Technical Information of China (English)

    秦旭; 张讲社; 延晓冬

    2009-01-01

    In recent years, extreme weather events have caused the widespread concern of the Whole world,but sustained extreme temperature events have been seldom researched up to now.The extreme threshold of temperature is defined in this paper by the percentile value of time series of daily maximum or minimum temperature,and the annual frequency of sustained(greater than two successive days)ex-treme high(FSEHT)and low temperature(FSELT)events during 1971-2005 in Yuncheng are alia.1yzed with the improved Empirical Mode Decomposition(EMD)method presented by Deering.The re-suits show that during the 35 years,the FSEHT and FSELT series both exhibit a linear decreasing trend in Yuncheng;the negative linear correlation between the FSELT series and the annual mean temperature series is statistically significant at the 0.05 confidence level, while changes in FSEHT are almost not af-fected by the annual mean temperature. Besides there are also oscillations of different periods in the two frequency series;and in view of principle periods,the oscillations of the two series are consistent with those of El Nino events.%采用每日最高(最低)气温的历史同期序列的分位数作为该日的极端阈值,运用改进的经验模态分解(empirical mode decomposition,EMD)方法对山西省运城市1971-2005年每年发生的持续(3 d及3 d以上)极端气温频数进行了初步分析.结果表明,1971-2005年运城市每年的持续极端高温频数(frequency of sustained extreme-high temperature,FSEHT)和持续极端低温频数(fre-quency of sustained extreme-low temperature,FSELT)序列均存在线性下降趋势;在0.05的水平下, 运城市的FSEHT序列与该地区的年平均气温序列的线性相关性不显著,而该地区的FSELT序列与年平均气温序列的负线性相关关系是显著的;此外,这两个频数序列分别存在不同的周期振荡.从主要周期看,运城市的FSEHT和FSELT序列与厄尔尼诺现象的周期相一致.

  15. Relativistic recursion relations for transition matrix elements

    CERN Document Server

    Martínez y Romero, R P; Salas-Brito, A L

    2004-01-01

    We review some recent results on recursion relations which help evaluating arbitrary non-diagonal, radial hydrogenic matrix elements of $r^\\lambda$ and of $\\beta r^\\lambda$ ($\\beta$ a Dirac matrix) derived in the context of Dirac relativistic quantum mechanics. Similar recursion relations were derived some years ago by Blanchard in the non relativistic limit. Our approach is based on a generalization of the second hypervirial method previously employed in the non-relativistic Schr\\"odinger case. An extension of the relations to the case of two potentials in the so-called unshifted case, but using an arbitrary radial function instead of a power one, is also given. Several important results are obtained as special instances of our recurrence relations, such as a generalization to the relativistic case of the Pasternack-Sternheimer rule. Our results are useful in any atomic or molecular calculation which take into account relativistic corrections.

  16. 在一台EMD 16-645E型机车柴油机上对各种动力组的机油消耗率排序

    Institute of Scientific and Technical Information of China (English)

    Kent Froelund; 蔡毓国

    2005-01-01

    在一台1500kW的EMD 16-645E型调车机车柴油机上进行了实时机油消耗(RTOC-111)测量,以评价各种商用动力组(气缸盖、活塞、气缸套和活塞环)在降低机油消耗和因而减少排气中的颗粒物质排放量方面的潜力.传统的容积式机油消耗测量技术不适用于测量单个动力组的机油消耗.通过使用超低硫含量(15 ppm)的柴油和以矿物质为基本成分的商用机油,RTOC-111技术将排气中的二氧化硫作为机油消耗的示踪物质.可利用机油中的硫含量和排气中的瞬时SO2浓度以及空气与燃油流量对实时机油消耗率逐秒进行计算.在该项研究中,对7种商用动力组的机油消耗率进行了排序,试验条件为北美货运机车典型的稳定运行状态.从最高到最低,机油消耗率约相差40%.选出了机油消耗率最低的商用动力组以用于下一步评估柴油机应用排气颗粒过滤器的可行性的发动机试验.

  17. Cross-Correlation Delay Estimation Method Based on EMD Decomposition and Reconstruction Algorithm%基于EMD分解重构的互相关时延估计方法

    Institute of Scientific and Technical Information of China (English)

    路晓妹; 寇文珍; 段渭军

    2013-01-01

    Under the background of the application for anti-sniper acoustic detection positioning system,tosolve the problems of low accuracy of delay estimation and large relative errors which appears when using the common correlation method,IMF reconstruction and noise elimination are applied in the estimation of acoustic detection positioning system of TDOA(time delay of arrival).For the selection of IMF components in reconstruction,a selection method based on Pearson correlation coefficient is designed.A cross-correlation delay estimation method based on EMD decomposition and reconstruction algorithm is put forward by selecting IMF components for reconstructing and denoising,and combining with the cross-correlation time delay estimation method.The validity of this method is proved by simulation experiment on the actual collected acoustic signal.%在反狙击手声探测定位系统应用背景下,针对常用相关法时延估计精度不高、相对误差较大等问题,将IMF重构消噪的思想应用于声探测定位系统TDOA(time delay of arrival)的估计中.针对重构过程中IMF分量的选取问题,设计了一种基于皮尔逊(Pearson)相关系数的选取方法,选取IMF分量进行重构消噪并结合互相关的时延估计方法,构成了基于EMD分解重构的互相关时延估计方法.通过对实际采集的声信号进行仿真实验,验证了该方法的有效性.

  18. ANNUAL FORECASTING OF WIND SPEED AND POWER IN WIND FARM BASED ON EMD%基于EMD分解的风电场风速和输出功率年度预测

    Institute of Scientific and Technical Information of China (English)

    王晓兰; 李辉

    2011-01-01

    In order to forecast monthly wind speed and wind power of the next year, the data of average wind speed per hour of the history can be used in this paper.The wind speed can be decomposed into several intrinsic mode functions (IMF) and trend term by empirical mode decomposition (EMD) method, different recursive least square (RLS) models to forecast each IMF and trend term are built up, these forecasting results of each IMF and trend term are combined to obtain the final forecasting results.The simulation experiment shown the average value of the MAPE is 16.25 % about wind speed forecasting and the prediction accuracy is improved considerably.Considering power characteristic of wind power generator, unit efficiency and operating conditions, the output power of the wind farm can be obtained.%应用历史年份的小时平均风速数据,预测下一年度逐月的风速和风电功率.对历史年份的逐月风速数据进行经验模式分解,采用递推最小二乘法建市各分量的二元线性回归预测模型,将各分量预测模型等权求和得到次年度对应月份的预测模型.对实测数据的仿真计算表明,提前一年的风速月度预测的平均MAPE为16.25%,提高了此类预测的精度.考虑具体风力发电机组的功率特性、机组效率和设备运行情况,可得出次年风电场的输出功率值.

  19. EMD and morphology based voltage disturbance detection method for power system connected with wind turbine generation%基于经验模态分解和形态学的风电并网电压故障检测

    Institute of Scientific and Technical Information of China (English)

    包广清; 宋泽; 吴国栋; 徐海龙

    2016-01-01

    针对风电场并网点电压故障引起的风机大规模脱网问题,提出了基于柔性形态算子和经验模态分解(empirical mode decomposition,EMD)去噪技术的电网电压故障检测方法。首先,利用EMD对采样信号进行时频自适应预处理,从而确定噪声主导模态;然后,通过柔性形态学变换加阈值输出,有效放大信号奇异点,避免了因电网电压信号周期性变化和噪声引起的背景梯度对检测结果的影响,实现故障定位检测。通过对不同噪声强度的电压暂降故障信号进行检测对比分析发现,随着信号信噪比下降,标准形态学方法的检测误差进一步增大,当信噪比达到25db时,甚至出现了误检现象,而柔性形态EMD检测方法仍然可以有效检测故障扰动的起止时间,表明该方法与标准形态学和小波阈值方法相比,在简化运算过程的同时可以获得更高的检测精度。最后,对某风电场并网点故障电压的分析结果与实测数据的一致性,验证了该方法可以有效检测电网电压的瞬态故障信息,从而为风电场无功补偿装置的投切控制提供了依据。%As the penetration of wind power has become significant, one of the important challenges of power distribution network with wind power integration is the risk of large-scale wind turbine tripping accidents caused by over/under voltage faults in farms and systems, which also leads to unexpected variations in frequency parameters and thereby power quality issues. Aiming at the difficulty to extract early weak fault feature for the voltage influenced by white noise and transient disturbance noise, a method combining empirical mode decomposition (EMD) with soft mathematical morphology (MM) was put forward in this paper. It was crucial for the requirements of fault ride-through devices, fault component extraction and reclose scheme on voltage detection accuracy and real-time performance

  20. A Cellular Potts Model simulating cell migration on and in matrix environments

    NARCIS (Netherlands)

    Scianna, M.; Preziosi, L.; Wolf, K.A.

    2013-01-01

    Cell migration on and through extracellular matrix is fundamental in a wide variety of physiological and pathological phenomena, and is exploited in scaffold-based tissue engineering. Migration is regulated by a number of extracellular matrix- or cell-derived biophysical parameters, such as matrix f