Analyzing threshold pressure limitations in microfluidic transistors for self-regulated microfluidic circuits.

PubMed

Kim, Sung-Jin; Yokokawa, Ryuji; Takayama, Shuichi

2012-12-03

This paper reveals a critical limitation in the electro-hydraulic analogy between a microfluidic membrane-valve (μMV) and an electronic transistor. Unlike typical transistors that have similar on and off threshold voltages, in hydraulic μMVs, the threshold pressures for opening and closing are significantly different and can change, even for the same μMVs depending on overall circuit design and operation conditions. We explain, in particular, how the negative values of the closing threshold pressures significantly constrain operation of even simple hydraulic μMV circuits such as autonomously switching two-valve microfluidic oscillators. These understandings have significant implications in designing self-regulated microfluidic devices.

Second generation experiments in fault tolerant software

NASA Technical Reports Server (NTRS)

Knight, J. C.

1987-01-01

The purpose of the Multi-Version Software (MVS) experiment is to obtain empirical measurements of the performance of multi-version systems. Twenty version of a program were prepared under reasonably realistic development conditions from the same specifications. The overall structure of the testing environment for the MVS experiment and its status are described. A preliminary version of the control system is described that was implemented for the MVS experiment to allow the experimenter to have control over the details of the testing. The results of an empirical study of error detection using self checks are also presented. The analysis of the checks revealed that there are great differences in the ability of individual programmers to design effective checks.

Variation among Staphylococcus aureus membrane vesicle proteomes affects cytotoxicity of host cells.

PubMed

Jeon, Hyejin; Oh, Man Hwan; Jun, So Hyun; Kim, Seung Il; Choi, Chi Won; Kwon, Hyo Il; Na, Seok Hyeon; Kim, Yoo Jeong; Nicholas, Asiimwe; Selasi, Gati Noble; Lee, Je Chul

2016-04-01

Staphylococcus aureus secretes membrane-derived vesicles (MVs), which can deliver virulence factors to host cells and induce cytopathology. However, the cytopathology of host cells induced by MVs derived from different S. aureus strains has not yet been characterized. In the present study, the cytotoxic activity of MVs from different S. aureus isolates on host cells was compared and the proteomes of S. aureus MVs were analyzed. The MVs purified from S. aureus M060 isolated from a patient with staphylococcal scalded skin syndrome showed higher cytotoxic activity toward host cells than that shown by MVs from three other clinical S. aureus isolates. S. aureus M060 MVs induced HEp-2 cell apoptosis in a dose-dependent manner, but the cytotoxic activity of MVs was completely abolished by treatment with proteinase K. In a proteomic analysis, the MVs from three S. aureus isolates not only carry 25 common proteins, but also carry ≥60 strain-specific proteins. All S. aureus MVs contained δ-hemolysin (Hld), γ-hemolysin, leukocidin D, and exfoliative toxin C, but exfoliative toxin A (ETA) was specifically identified in S. aureus M060 MVs. ETA was delivered to HEp-2 cells via S. aureus MVs. Both rETA and rHld induced cytotoxicity in HEp-2 cells. In conclusion, MVs from clinical S. aureus isolates differ with respect to cytotoxic activity in host cells, and these differences may result from differences in the MV proteomes. Further proteogenomic analysis or mutagenesis of specific genes is necessary to identify cytotoxic factors in S. aureus MVs. Copyright © 2016 Elsevier Ltd. All rights reserved.

Analyzing threshold pressure limitations in microfluidic transistors for self-regulated microfluidic circuits

PubMed Central

Kim, Sung-Jin; Yokokawa, Ryuji; Takayama, Shuichi

2012-01-01

This paper reveals a critical limitation in the electro-hydraulic analogy between a microfluidic membrane-valve (μMV) and an electronic transistor. Unlike typical transistors that have similar on and off threshold voltages, in hydraulic μMVs, the threshold pressures for opening and closing are significantly different and can change, even for the same μMVs depending on overall circuit design and operation conditions. We explain, in particular, how the negative values of the closing threshold pressures significantly constrain operation of even simple hydraulic μMV circuits such as autonomously switching two-valve microfluidic oscillators. These understandings have significant implications in designing self-regulated microfluidic devices. PMID:23284181

Gut commensal microvesicles reproduce parent bacterial signals to host immune and enteric nervous systems.

PubMed

Al-Nedawi, Khalid; Mian, M Firoz; Hossain, Nazia; Karimi, Khalil; Mao, Yu-Kang; Forsythe, Paul; Min, Kevin K; Stanisz, Andrew M; Kunze, Wolfgang A; Bienenstock, John

2015-02-01

Ingestion of a commensal bacteria, Lactobacillus rhamnosus JB-1, has potent immunoregulatory effects, and changes nerve-dependent colon migrating motor complexes (MMCs), enteric nerve function, and behavior. How these alterations occur is unknown. JB-1 microvesicles (MVs) are enriched for heat shock protein components such as chaperonin 60 heat-shock protein isolated from Escherichia coli (GroEL) and reproduce regulatory and neuronal effects in vitro and in vivo. Ingested labeled MVs were detected in murine Peyer's patch (PP) dendritic cells (DCs) within 18 h. After 3 d, PP and mesenteric lymph node DCs assumed a regulatory phenotype and increased functional regulatory CD4(+)25(+)Foxp3+ T cells. JB-1, MVs, and GroEL similarly induced phenotypic change in cocultured DCs via multiple pathways including C-type lectin receptors specific intercellular adhesion molecule-3 grabbing non-integrin-related 1 and Dectin-1, as well as TLR-2 and -9. JB-1 and MVs also decreased the amplitude of neuronally dependent MMCs in an ex vivo model of peristalsis. Gut epithelial, but not direct neuronal application of, MVs, replicated functional effects of JB-1 on in situ patch-clamped enteric neurons. GroEL and anti-TLR-2 were without effect in this system, suggesting the importance of epithelium neuron signaling and discrimination between pathways for bacteria-neuron and -immune communication. Together these results offer a mechanistic explanation of how Gram-positive commensals and probiotics may influence the host's immune and nervous systems. © FASEB.

Circulating membrane-derived microvesicles in redox biology.

PubMed

Larson, Michael Craig; Hillery, Cheryl A; Hogg, Neil

2014-08-01

Microparticles or microvesicles (MVs) are subcellular membrane blebs shed from all cells in response to various stimuli. MVs carry a battery of signaling molecules, many of them related to redox-regulated processes. The role of MVs, either as a cause or as a result of cellular redox signaling, has been increasingly recognized over the past decade. This is in part due to advances in flow cytometry and its detection of MVs. Notably, recent studies have shown that circulating MVs from platelets and endothelial cells drive reactive species-dependent angiogenesis; circulating MVs in cancer alter the microenvironment and enhance invasion through horizontal transfer of mutated proteins and nucleic acids and harbor redox-regulated matrix metalloproteinases and procoagulative surface molecules; and circulating MVs from red blood cells and other cells modulate cell-cell interactions through scavenging or production of nitric oxide and other free radicals. Although our recognition of MVs in redox-related processes is growing, especially in the vascular biology field, much remains unknown regarding the various biologic and pathologic functions of MVs. Like reactive oxygen and nitrogen species, MVs were originally believed to have a solely pathological role in biology. And like our understanding of reactive species, it is now clear that MVs also play an important role in normal growth, development, and homeostasis. We are just beginning to understand how MVs are involved in various biological processes-developmental, homeostatic, and pathological-and the role of MVs in redox signaling is a rich and exciting area of investigation. Copyright © 2014 Elsevier Inc. All rights reserved.

Continued Development of Internet Protocols under the IBM OS/MVS operating System

DTIC Science & Technology

1986-03-10

this contract, the UCLA Office of Academic Computing (OAC) continued its participation in the Internet research effort of * DARPA. OAC’s effort has...is adapted and condensed from TR51. 1.2 NAME RESOLVER The Internet research community is installing a system of name resolvers and name servers...several attributes favoring their use within the ACP. • The "C" language is heavily used within the DARPA Internet research community, giving it an

Myeloid microvesicles are a marker and therapeutic target for neuroinflammation.

PubMed

Verderio, Claudia; Muzio, Luca; Turola, Elena; Bergami, Alessandra; Novellino, Luisa; Ruffini, Francesca; Riganti, Loredana; Corradini, Irene; Francolini, Maura; Garzetti, Livia; Maiorino, Chiara; Servida, Federica; Vercelli, Alessandro; Rocca, Mara; Dalla Libera, Dacia; Martinelli, Vittorio; Comi, Giancarlo; Martino, Gianvito; Matteoli, Michela; Furlan, Roberto

2012-10-01

Microvesicles (MVs) have been indicated as important mediators of intercellular communication and are emerging as new biomarkers of tissue damage. Our previous data indicate that reactive microglia/macrophages release MVs in vitro. The aim of the study was to evaluate whether MVs are released by microglia/macrophages in vivo and whether their number varies in brain inflammatory conditions, such as multiple sclerosis (MS). Electron and fluorescence microscopy and flow cytometry were used to detect myeloid MVs in the cerebrospinal fluid (CSF) of healthy controls, MS patients, and rodents affected by experimental autoimmune encephalomyelitis (EAE), the animal model of MS. Myeloid MVs were detected in CSF of healthy controls. In relapsing and remitting EAE mice, the concentration of myeloid MVs in the CSF was significantly increased and closely associated with disease course. Analysis of MVs in the CSF of 28 relapsing patients and 28 patients with clinical isolated syndrome from 2 independent cohorts revealed higher levels of myeloid MVs than in 13 age-matched controls, indicating a clinical value of MVs as a companion tool to capture disease activity. Myeloid MVs were found to spread inflammatory signals both in vitro and in vivo at the site of administration; mice impaired in MV shedding were protected from EAE, suggesting a pathogenic role for MVs in the disease. Finally, FTY720, the first approved oral MS drug, significantly reduced the amount of MVs in the CSF of EAE-treated mice. These findings identify myeloid MVs as a marker and therapeutic target of brain inflammation. Copyright © 2012 American Neurological Association.

Microvesicle-mediated Wnt/β-Catenin Signaling Promotes Interspecies Mammary Stem/Progenitor Cell Growth.

PubMed

Bussche, Leen; Rauner, Gat; Antonyak, Marc; Syracuse, Bethany; McDowell, Melissa; Brown, Anthony M C; Cerione, Richard A; Van de Walle, Gerlinde R

2016-11-18

Signaling mechanisms that regulate mammary stem/progenitor cell (MaSC) self-renewal are essential for developmental changes that occur in the mammary gland during pregnancy, lactation, and involution. We observed that equine MaSCs (eMaSCs) maintain their growth potential in culture for an indefinite period, whereas canine MaSCs (cMaSCs) lose their growth potential in long term cultures. We then used this system to investigate the role of microvesicles (MVs) in promoting self-renewal properties. We found that Wnt3a and Wnt1 were expressed at higher levels in MVs isolated from eMaSCs compared with those from cMaSCs. Furthermore, eMaSC-MVs were able to induce Wnt/β-catenin signaling in different target cells, including cMaSCs. Interestingly, the induction of Wnt/β-catenin signaling in cMaSCs was prolonged when using eMaSC-MVs compared with recombinant Wnt proteins, indicating that MVs are not only important for transport of Wnt proteins, but they also enhance their signaling activity. Finally, we demonstrate that the eMaSC-MVs-mediated activation of the Wnt/β-catenin signaling pathway in cMaSCs significantly improves the ability of cMaSCs to grow as mammospheres and, importantly, that this effect is abolished when eMaSC-MVs are treated with Wnt ligand inhibitors. This suggests that this novel form of intercellular communication plays an important role in self-renewal. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

Ada (Trade Name) Compiler Validation Summary Report: International Business Machines Corporation. IBM Development System for the Ada Language System, Version 1.1.0, IBM 4381 under MVS.

DTIC Science & Technology

1988-05-22

TITLE (andSubtile) 5. TYPE OF REPORT & PERIOD COVERED Ada Compler Validation Summary Report: 22 May 1987 to 22 May 1988 International Business Machines...IBM Development System for the Ada Language System, Version 1.1.0, International Business Machines Corporation, Wright-Patterson AFB. IBM 4381 under...SUMMARY REPORT: International Business Machines Corporation IBM Development System f’or the Ada Language System, Version 1.1.0 IBM 4381 under MVS

Circulating Membrane-Derived Microvesicles in Redox Biology

PubMed Central

Larson, Michael Craig; Hillery, Cheryl A.; Hogg, Neil

2015-01-01

Microparticles or microvesicles (MV) are sub-cellular membrane blebs shed from all cells in response to various stimuli. MVs carry a battery of signaling molecules, many of them related to redox-regulated processes. The role of MVs, either as a cause or result of cellular redox signaling has been increasingly recognized over the past decade. This is in part due to advances in flow cytometry and its detection of MVs. Notably, recent studies have shown circulating MVs from platelets and endothelial cells drive reactive species-dependent angiogenesis; circulating MVs in cancer alter the microenvironment and enhance invasion through horizontal transfer of mutated proteins and nucleic acids, and harbor redox-regulated matrix metalloproteinases and pro-coagulative surface molecules; and circulating MVs from RBCs and other cells modulate cell-cell interactions through scavenging or production of nitric oxide and other free radicals. While our recognition of MVs in redox-related processes is growing, especially in the vascular biology field, much remains unknown regarding the various biologic and pathologic functions of MVs. Like reactive oxygen and nitrogen species, MVs were originally believed to have a solely a pathological role in biology. And like our understanding of reactive species, it is now clear that MVs also play an important role in normal growth, development, and homeostasis. We are just beginning to understand how MVs are involved in various biological processes—developmental, homeostatic and pathological—and the role of MVs in redox signaling is an rich and exciting area of investigation. PMID:24751526

Macrophage-derived microvesicles promote proliferation and migration of Schwann cell on peripheral nerve repair

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

Zhan, Chuan, E-mail: zhchuansy@163.com; Ma, Cheng-bin; Yuan, Hong-mou

Background: Macrophages have been implicated in peripheral nerve regeneration. However, whether macrophages-derived microvesicles (MVs) are involved in this process remains unknown. In the present study, the effects of macrophages-derived MVs on proliferation and migration of Schwann cells (SCs) were evaluated in both in vitro and in vivo. Methods: Human monocytic leukaemia cell line (THP-1) was successfully driven to M1 and M2 phenotypes by delivery of either IFN-γ or IL-4, respectively. SCs incubated with M1 or M2 macrophages-derived MVs, the cell migration and proliferation were assessed, and expression levels of nerve growth factor (NGF) and Laminin were measured. A rat model of sciaticmore » nerve was established and the effects of macrophages-derived MVs on nerve regeneration were investigated. Results: M2-derived MVs elevated migration, proliferation, NFG and Laminin protein levels of SCs compared with M1-or M0-derived MVs. The relative expression levels of miR-223 were also increased in M2 macrophages and M2-derived MVs. Transfected M2 macrophages with miR-223 inhibitor then co-incubated with SCs, an inhibition of cell migration and proliferation and a down-regulated levels of NFG and Laminin protein expression were observed. In vivo, M2-derived MVs significantly increased the infiltration and axon number of SCs. Conclusion: M2-derived MVs promoted proliferation and migration of SCs in vitro and in vivo, which provided a therapeutic strategy for nerve regeneration. - Highlights: • M2 macrophages-derived MVs elevated migration and proliferation of SCs. • M2 macrophages-derived MVs up-regulated NFG and Laminin expression of SCs. • MiR-223 expression was increased in M2 macrophages-derived MVs. • MiR-223 inhibitor reduced migration and proliferation of SCs co-incubated with MVs. • MiR-223 inhibitor down-regulated NFG and Laminin levels of SCs co-incubated with MVs.« less

Ada (Tradename) Compiler Validation Summary Report. International Business Machines Corporation. IBM Development System for the Ada Language for MVS, Version 1.0. IBM 4381 (IBM System/370) under MVS.

DTIC Science & Technology

1986-05-05

AVF-VSR-36.0187 Ada" COMPILER VALIDATION SUMMARY REPORT: International Business Machines Corporation IBM Development System for the Ada Language for...withdrawn from ACVC Version 1.7 were not run. The compiler was tested using command scripts provided by International Business Machines Corporation. These...APPENDIX A COMPLIANCE STATEMENT International Business Machines Corporation has submitted the following compliance statement concerning the IBM

Magnetic vestibular stimulation modulates default mode network fluctuations.

PubMed

Boegle, Rainer; Stephan, Thomas; Ertl, Matthias; Glasauer, Stefan; Dieterich, Marianne

2016-02-15

Strong magnetic fields (>1 Tesla) can cause dizziness and it was recently shown that healthy subjects (resting in total darkness) developed a persistent nystagmus even when remaining completely motionless within a MR tomograph. Consequently, it was speculated that this magnetic vestibular stimulation (MVS) might influence fMRI results, as nystagmus is indicative of an imbalance in the vestibular system, potentially influencing other systems via multisensory vestibular interactions. The objective of our study was to investigate whether MVS does indeed modulate BOLD signal fluctuations. We recorded eye movements, as well as, resting-state fMRI of 30 volunteers in darkness at 1.5 T and 3.0 T to answer the question whether MVS modulated parts of the default mode resting-state network (DMN) in accordance with the Lorentz-force model for MVS, while distinguishing this from the known signal increase due to field strength related imaging effects. Our results showed that modulation of the default mode network occurred mainly in areas associated with vestibular and ocular motor function, and was in accordance with the Lorentz-force model, i.e., double than the expected signal scaling due to field strength alone. We discuss the implications of our findings for the interpretation of studies using resting-state fMRI, especially those concerning vestibular research. We conclude that MVS needs to be considered in vestibular research to avoid biased results, but it might also offer the possibility of manipulating network dynamics and may thus help in studying the brain as a dynamical system. Copyright © 2015 Elsevier Inc. All rights reserved.

Liquid Crystal Droplet-Based Amplification of Microvesicles that are Shed by Mammalian Cells

PubMed Central

Tan, Lie Na; Wiepz, Gregory J.; Miller, Daniel S.; Shusta, Eric V.; Abbott, Nicholas L.

2014-01-01

Membrane-derived microvesicles (MVs) shed by cells are being investigated for their role in intercellular communication and as potential biomarkers of disease, but facile and sensitive methods for their analysis do not exist. Here we demonstrate new principles for analysis of MVs that use micrometer-sized droplets of liquid crystals (LCs) to amplify MVs that are selectively captured via antibody-mediated interactions. The influence of the MVs on the micrometer-sized LC droplets is shown to be readily quantified via use of flow cytometry. The methodology was developed using MVs shed by epidermoid carcinoma A431 cells that contain epidermal growth factor receptor (EGFR) as an important and representative example of MVs containing signaling proteins that play a central role in cancer. The LC droplets were found to be sensitive to 106 MVs containing EGFR (relative to controls using isotype control antibody) and to possess a dynamic range of response across several orders of magnitude. Because the 100 nm-sized MVs captured via EGFR generate an optical response in the micrometer-sized LC droplets that can be readily detected by flow cytometry in light scattering mode, the approach possesses significant advantages over direct detection of MVs by flow cytometry. The LC droplets are also substantially more sensitive than techniques such as immunoblotting because the lipid-component of the MVs serves to amplify the antibody-mediated capture of the target proteins in the MVs. Other merits of the approach are defined and discussed in the paper. PMID:24667742

My Vocational Situation (MVS): Case Example and Psychometric Review.

PubMed

Nitsch, Kristian P; Pedersen, Jessica; Miliotto, Alexandra; Petersen, Brett; Robbins, Samantha; Garcia, Ana; Hoisington, Molly Ansel; The, Kimberly J; Smiley, Jill; Janikowski, Timothy

This case report provides an overview of the psychometric properties and clinical utility of the My Vocational Situation (MVS) instrument. The accompanying hypothetical case description illustrates how clinicians could use the MVS to evaluate vocational preferences and outcomes and how the MVS can be used to inform treatment planning and rehabilitation decision making. The information contained in this report is intended to familiarize clinicians with the administration and scoring of the MVS, the psychometric information necessary to interpret results obtained from the MVS, and how the results could be used to provide comprehensive, patient-centered care. It is important to note that the information provided represents only a sample of the available research literature on the MVS. Copyright © 2017 by the American Occupational Therapy Association, Inc.

Proteinase 3 Is a Phosphatidylserine-binding Protein That Affects the Production and Function of Microvesicles.

PubMed

Martin, Katherine R; Kantari-Mimoun, Chahrazade; Yin, Min; Pederzoli-Ribeil, Magali; Angelot-Delettre, Fanny; Ceroi, Adam; Grauffel, Cédric; Benhamou, Marc; Reuter, Nathalie; Saas, Philippe; Frachet, Philippe; Boulanger, Chantal M; Witko-Sarsat, Véronique

2016-05-13

Proteinase 3 (PR3), the autoantigen in granulomatosis with polyangiitis, is expressed at the plasma membrane of resting neutrophils, and this membrane expression increases during both activation and apoptosis. Using surface plasmon resonance and protein-lipid overlay assays, this study demonstrates that PR3 is a phosphatidylserine-binding protein and this interaction is dependent on the hydrophobic patch responsible for membrane anchorage. Molecular simulations suggest that PR3 interacts with phosphatidylserine via a small number of amino acids, which engage in long lasting interactions with the lipid heads. As phosphatidylserine is a major component of microvesicles (MVs), this study also examined the consequences of this interaction on MV production and function. PR3-expressing cells produced significantly fewer MVs during both activation and apoptosis, and this reduction was dependent on the ability of PR3 to associate with the membrane as mutating the hydrophobic patch restored MV production. Functionally, activation-evoked MVs from PR3-expressing cells induced a significantly larger respiratory burst in human neutrophils compared with control MVs. Conversely, MVs generated during apoptosis inhibited the basal respiratory burst in human neutrophils, and those generated from PR3-expressing cells hampered this inhibition. Given that membrane expression of PR3 is increased in patients with granulomatosis with polyangiitis, MVs generated from neutrophils expressing membrane PR3 may potentiate oxidative damage of endothelial cells and promote the systemic inflammation observed in this disease. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

Proteinase 3 Is a Phosphatidylserine-binding Protein That Affects the Production and Function of Microvesicles*

PubMed Central

Martin, Katherine R.; Kantari-Mimoun, Chahrazade; Yin, Min; Pederzoli-Ribeil, Magali; Angelot-Delettre, Fanny; Ceroi, Adam; Grauffel, Cédric; Benhamou, Marc; Reuter, Nathalie; Saas, Philippe; Frachet, Philippe; Boulanger, Chantal M.; Witko-Sarsat, Véronique

2016-01-01

Proteinase 3 (PR3), the autoantigen in granulomatosis with polyangiitis, is expressed at the plasma membrane of resting neutrophils, and this membrane expression increases during both activation and apoptosis. Using surface plasmon resonance and protein-lipid overlay assays, this study demonstrates that PR3 is a phosphatidylserine-binding protein and this interaction is dependent on the hydrophobic patch responsible for membrane anchorage. Molecular simulations suggest that PR3 interacts with phosphatidylserine via a small number of amino acids, which engage in long lasting interactions with the lipid heads. As phosphatidylserine is a major component of microvesicles (MVs), this study also examined the consequences of this interaction on MV production and function. PR3-expressing cells produced significantly fewer MVs during both activation and apoptosis, and this reduction was dependent on the ability of PR3 to associate with the membrane as mutating the hydrophobic patch restored MV production. Functionally, activation-evoked MVs from PR3-expressing cells induced a significantly larger respiratory burst in human neutrophils compared with control MVs. Conversely, MVs generated during apoptosis inhibited the basal respiratory burst in human neutrophils, and those generated from PR3-expressing cells hampered this inhibition. Given that membrane expression of PR3 is increased in patients with granulomatosis with polyangiitis, MVs generated from neutrophils expressing membrane PR3 may potentiate oxidative damage of endothelial cells and promote the systemic inflammation observed in this disease. PMID:26961880

Minimal access surgery for mitral valve endocarditis.

PubMed

Barbero, Cristina; Marchetto, Giovanni; Ricci, Davide; Mancuso, Samuel; Boffini, Massimo; Cecchi, Enrico; De Rosa, Francesco Giuseppe; Rinaldi, Mauro

2017-08-01

Minimal access mitral valve surgery (MVS) has already proved to be feasible and effective with low perioperative mortality and excellent long-term outcomes. However, experience in more complex valve diseases such as infective endocarditis (IE) still remains limited. The aim of this retrospective study was to evaluate early and long-term results of minimal access MVS for IE. Data were entered into a dedicated database. Analysis was performed retrospectively for the 8-year period between January 2007 and April 2015. During the study period, 35 consecutive patients underwent minimal access MVS for IE at our department. Twenty-four had diagnosis of native MV endocarditis (68.6%) and 11 of mitral prosthesis endocarditis (31.4%).Thirty patients underwent early MVS (85.7%), and 5 patients were operated after the completion of antibiotic treatment (14.3%). Seven patients underwent MV repair (20%), 17 patients underwent MV replacement (48.6%), and 11 patients underwent mitral prosthesis replacement (31.4%). Thirty-day mortality was 11.4% (4 patients). No neurological or vascular complications were reported. One patient underwent reoperation for prosthesis IE relapse after 37 days. Overall actuarial survival rate at 1 and 5 years was 83%; freedom from MV reoperation and/or recurrence of IE at 1 and 5 years was 97%. Minimally invasive MVS for IE is feasible and associated with good early and long-term results. Preoperative accurate patient selection and transoesophageal echocardiography evaluation is mandatory for surgical planning. © The Author 2017. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

Lactobacillus casei BL23 Produces Microvesicles Carrying Proteins That Have Been Associated with Its Probiotic Effect

PubMed Central

Domínguez Rubio, A. Paula; Martínez, Jimena H.; Martínez Casillas, Diana C.; Coluccio Leskow, Federico; Piuri, Mariana; Pérez, Oscar E.

2017-01-01

Archaea, bacteria, and eukarya secrete membrane microvesicles (MVs) as a mechanism for intercellular communication. We report the isolation and characterization of MVs from the probiotic strain Lactobacillus casei BL23. MVs were characterized using analytical high performance techniques, DLS, AFM and TEM. Similar to what has been described for other Gram-positive bacteria, MVs were on the nanometric size range (30–50 nm). MVs carried cytoplasmic components such as DNA, RNA and proteins. Using a proteomic approach (LC-MS), we identified a total of 103 proteins; 13 exclusively present in the MVs. The MVs content included cell envelope associated and secretory proteins, heat and cold shock proteins, several metabolic enzymes, proteases, structural components of the ribosome, membrane transporters, cell wall-associated hydrolases and phage related proteins. In particular, we identified proteins described as mediators of Lactobacillus’ probiotic effects such as p40, p75 and the product of LCABL_31160, annotated as an adhesion protein. The presence of these proteins suggests a role for the MVs in the bacteria-gastrointestinal cells interface. The expression and further encapsulation of proteins into MVs of GRAS (Generally Recognized as Safe) bacteria could represent a scientific novelty, with applications in food, nutraceuticals and clinical therapies. PMID:28979244

Farmers’ Preference for Rice Traits: Insights from Farm Surveys in Central Luzon, Philippines, 1966-2012

PubMed Central

Laborte, Alice G.; Paguirigan, Neale C.; Moya, Piedad F.; Nelson, Andrew; Sparks, Adam H.; Gregorio, Glenn B.

2015-01-01

Many modern rice varieties (MVs) have been released but only a few have been widely adopted by farmers. To understand farmers’ preferences, we characterized MVs released in the Philippines from 1966 to 2013 and identified important characteristics of the varieties that were widely adopted in Central Luzon using farm surveys conducted in 1966–2012. We found that farmers adopt MVs that are high yielding, mature faster, and have long and slender grains, high milling recovery, and intermediate amylose content. The amylose content of adopted varieties has been declining, suggesting value in developing softer rice. To have a high potential for adoption, new MVs should have characteristics within the ranges of values observed for the adopted MVs. In addition, new MVs should have higher head rice recovery, less chalky grains, and better resistance to pests and diseases. Most MVs released in 2005–2013 compared poorly in these three traits. To reduce the risk of severe outbreaks, broad spectrum resistance should be incorporated into new MVs. This analysis of five decades of farm surveys provides insights into the varietal characteristics preferred by farmers which could contribute to the establishment of a product profile for developing improved MVs that are more targeted and, hence, would have high potential for adoption by farmers in Central Luzon and similar areas. We recommend a similar analysis be done in other major rice growing regions to aid the development of MVs that are more responsive to farmers’ needs and preferences. PMID:26317505

[Discordance between mitral valve area (MVA) and pressure gradient in patients with mitral valve stenosis: mean transmitral valve gradient is a severity index or a tolerance index of severity of mitralss valve stenosis?

PubMed

Najih, Hayat; Arous, Salim; Laarje, Aziza; Baghdadi, Dalila; Benouna, Mohamed Ghali; Azzouzi, Leila; Habbal, Rachida

2016-01-01

Rheumatic mitral valve stenosis (MVS) is a frequent valvulopathy in developing countries. However, industrialized countries have seen the emergence of new etiologies of MVS in recent years, in particular drug-induced and/or toxic valvular regurgitation and stenosis. For this reason, the echocardiographic assessment of MVS and especially the definition of objective diagnostic criteria for severe MVS remains relevant. The objectives are: to determine whether there is a direct causal link between mean transmitral gradient (MTG) and severity of MVS in patients with severe MVS or true severe MVS (primary criterion); to analyze different parameters determining mean transmitral gradient (MTG) (secondary criterion). We conducted a single-center cross-sectional study including all patients with severe or true severe MVS admitted to the Department of Cardiology, University Hospital Ibn Rushd, Casablanca over a period of one year (January 2014-December 2014). We analyzed data from two groups of patients separately: those with a mean transmitral gradient<10 mmHg (group 1) and those with a gradient>10mmHg (group 2). 50 patients with severe or true severe MVS have been included in the study. The average age of our patients was 41.7 years with a female predominance (sex ratio 0,25). 64% of patients had severe MVS and 36% of patients had true severe MVS. 52% (26 patients) had MTG < 10mmHg and 48% (24 patients) had mean gradient> 10mmHg, suggesting no direct correlation between the severity of MVS and MTG (Pearson's correlation coefficient R: -0,137). With regards to dyspnea, 80% of patients of group 1 had stage II NYHA dyspnea (classification system) and 70% of patients of group 2 had stage III NYHA dyspnea (41%) or IV NYHA dyspnea (29%), which means that there was a significant correlation between MTG and the severity of dyspnea (R: 0,586 and p: 0,001). The analytical study of heart rate and the presence of cardiac decompensation compared with mean gradient transmitral showed a significant correlation. Indeed, among patients in group 1, 96% had HR between 60 and 100 bpm and no patient had decompensated heart failure. In group 2, 54% (13 patients) had a HR> 100 bpm and 7 of them (53%) had left decompensated heart failure. The analysis of systolic pulmonary artery pressure conducted in both groups of the study revealed the existence of a statistically significant correlation (R: 0,518 and P: 0,001) between systolic pulmonary artery pressure (SPAP) and MTG. Ventricular rhythm regularity and right ventricular function were not correlated with MTG (R: 0,038 and R: - 0,002 respectively). Mean transmitral gradient is a good indicator of mitral stenosis tolerance but it imperfectly reflects mitral stenosis severity as this depends on several hemodynamic parameters. True severe mitral stenosis may have mean transmitral gradient < 10mmHg, that is why the value of MTG should never be interpreted as single value.

Porphyromonas gingivalis outer membrane vesicles enter human epithelial cells via an endocytic pathway and are sorted to lysosomal compartments.

PubMed

Furuta, Nobumichi; Tsuda, Kayoko; Omori, Hiroko; Yoshimori, Tamotsu; Yoshimura, Fuminobu; Amano, Atsuo

2009-10-01

Porphyromonas gingivalis, a periodontal pathogen, secretes outer membrane vesicles (MVs) that contain major virulence factors, including major fimbriae and proteases termed gingipains, although it is not confirmed whether MVs enter host cells. In this study, we analyzed the mechanisms involved in the interactions of P. gingivalis MVs with human epithelial cells. Our results showed that MVs swiftly adhered to HeLa and immortalized human gingival epithelial cells in a fimbria-dependent manner and then entered via a lipid raft-dependent endocytic pathway. The intracellular MVs were subsequently routed to early endosome antigen 1-associated compartments and then were sorted to lysosomal compartments within 90 min, suggesting that intracellular MVs were ultimately degraded by the cellular digestive machinery. However, P. gingivalis MVs remained there for over 24 h and significantly induced acidified compartment formation after being taken up by the cellular digestive machinery. In addition, MV entry was shown to be mediated by a novel pathway for transmission of bacterial products into host cells, a Rac1-regulated pinocytic pathway that is independent of caveolin, dynamin, and clathrin. Our findings indicate that P. gingivalis MVs efficiently enter host cells via an endocytic pathway and survive within the endocyte organelles for an extended period, which provides better understanding of the role of MVs in the etiology of periodontitis.

Porphyromonas gingivalis Outer Membrane Vesicles Enter Human Epithelial Cells via an Endocytic Pathway and Are Sorted to Lysosomal Compartments ▿

PubMed Central

Furuta, Nobumichi; Tsuda, Kayoko; Omori, Hiroko; Yoshimori, Tamotsu; Yoshimura, Fuminobu; Amano, Atsuo

2009-01-01

Porphyromonas gingivalis, a periodontal pathogen, secretes outer membrane vesicles (MVs) that contain major virulence factors, including major fimbriae and proteases termed gingipains, although it is not confirmed whether MVs enter host cells. In this study, we analyzed the mechanisms involved in the interactions of P. gingivalis MVs with human epithelial cells. Our results showed that MVs swiftly adhered to HeLa and immortalized human gingival epithelial cells in a fimbria-dependent manner and then entered via a lipid raft-dependent endocytic pathway. The intracellular MVs were subsequently routed to early endosome antigen 1-associated compartments and then were sorted to lysosomal compartments within 90 min, suggesting that intracellular MVs were ultimately degraded by the cellular digestive machinery. However, P. gingivalis MVs remained there for over 24 h and significantly induced acidified compartment formation after being taken up by the cellular digestive machinery. In addition, MV entry was shown to be mediated by a novel pathway for transmission of bacterial products into host cells, a Rac1-regulated pinocytic pathway that is independent of caveolin, dynamin, and clathrin. Our findings indicate that P. gingivalis MVs efficiently enter host cells via an endocytic pathway and survive within the endocyte organelles for an extended period, which provides better understanding of the role of MVs in the etiology of periodontitis. PMID:19651865

Ada Compiler Validation Summary Report: Certificate Number: 890420W1. 10075 International Business Machines Corporation. IBM Development System, for the Ada Language CMS/MVS Ada Cross Compiler, Version 2.1.1 IBM 3083 Host and IBM 4381 Target

DTIC Science & Technology

1989-04-20

International business Machines Corporati,:i IBM Development System for the Ada Language, CMS/MVS Ada Cross Compiler, Version 2.1.1, Wright-Patterson AFB, IBM...VALIDATION SUMMARY REPORT: Certificate Number: 890420W1.10075 International Business Machines Corporation IBM Development System for the Ada Language CMS...command scripts provided by International Business Machines Corporation and reviewed by the validation team. The compiler was tested using all default

Ada Compiler Validation Summary Report: Certificate Number 880318W1. 09042, International Business Machines Corporation, IBM Development System for the Ada Language, Version 2.1.0, IBM 4381 under MVS/XA, Host and Target

DTIC Science & Technology

1988-03-28

International Business Machines Corporation IBM Development System for the Ada Language, Version 2.1.0 IBM 4381 under MVS/XA, host and target Completion...Joint Program Office, AJPO 20. ABSTRACT (Continue on reverse side if necessary and identify by block number) International Business Machines Corporation...in the compiler listed in this declaration. I declare that International Business Machines Corporation is the owner of record of the object code of

Comparison of illumina and 454 deep sequencing in participants failing raltegravir-based antiretroviral therapy.

PubMed

Li, Jonathan Z; Chapman, Brad; Charlebois, Patrick; Hofmann, Oliver; Weiner, Brian; Porter, Alyssa J; Samuel, Reshmi; Vardhanabhuti, Saran; Zheng, Lu; Eron, Joseph; Taiwo, Babafemi; Zody, Michael C; Henn, Matthew R; Kuritzkes, Daniel R; Hide, Winston; Wilson, Cara C; Berzins, Baiba I; Acosta, Edward P; Bastow, Barbara; Kim, Peter S; Read, Sarah W; Janik, Jennifer; Meres, Debra S; Lederman, Michael M; Mong-Kryspin, Lori; Shaw, Karl E; Zimmerman, Louis G; Leavitt, Randi; De La Rosa, Guy; Jennings, Amy

2014-01-01

The impact of raltegravir-resistant HIV-1 minority variants (MVs) on raltegravir treatment failure is unknown. Illumina sequencing offers greater throughput than 454, but sequence analysis tools for viral sequencing are needed. We evaluated Illumina and 454 for the detection of HIV-1 raltegravir-resistant MVs. A5262 was a single-arm study of raltegravir and darunavir/ritonavir in treatment-naïve patients. Pre-treatment plasma was obtained from 5 participants with raltegravir resistance at the time of virologic failure. A control library was created by pooling integrase clones at predefined proportions. Multiplexed sequencing was performed with Illumina and 454 platforms at comparable costs. Illumina sequence analysis was performed with the novel snp-assess tool and 454 sequencing was analyzed with V-Phaser. Illumina sequencing resulted in significantly higher sequence coverage and a 0.095% limit of detection. Illumina accurately detected all MVs in the control library at ≥0.5% and 7/10 MVs expected at 0.1%. 454 sequencing failed to detect any MVs at 0.1% with 5 false positive calls. For MVs detected in the patient samples by both 454 and Illumina, the correlation in the detected variant frequencies was high (R2 = 0.92, P<0.001). Illumina sequencing detected 2.4-fold greater nucleotide MVs and 2.9-fold greater amino acid MVs compared to 454. The only raltegravir-resistant MV detected was an E138K mutation in one participant by Illumina sequencing, but not by 454. In participants of A5262 with raltegravir resistance at virologic failure, baseline raltegravir-resistant MVs were rarely detected. At comparable costs to 454 sequencing, Illumina demonstrated greater depth of coverage, increased sensitivity for detecting HIV MVs, and fewer false positive variant calls.

Effects of Antioxidant Components of AREDS Vitamins and Zinc Ions on Endothelial Cell Activation: Implications for Macular Degeneration

PubMed Central

Zeng, Shemin; Hernández, Jasmine

2012-01-01

Purpose. To investigate whether the benefit of Age-Related Eye Disease Study (AREDS) formula multivitamins and zinc in the progression of age-related macular degeneration (AMD) may occur through inhibiting inflammatory events in the choroid. Methods. Mouse C166 endothelial cells (ECs) and, for some experiments, human retinal pigment epithelium (RPE)–choroid organ cultures were treated with AREDS multivitamin solution (MVS) or ZnCl2. The cytotoxicity of MVS was evaluated using a lactate dehydrogenase colorimetric assay. Cell motility was assessed using a scratch assay. Macrophage adhesion to EC monolayers or ICAM-1 protein was determined after MVS and zinc treatment and with or without lipopolysaccharide (LPS). Quantitative reverse transcription PCR and Western blot analysis were used to determine the effects of MVS on the expression of proinflammatory molecules in treated and untreated cells. Results. AREDS MVS and zinc did not affect C166 EC viability until the 56th hour after treatment. Scratch assays showed partial inhibition of MVS and zinc on EC migration. In cell adhesion assays, MVS and zinc decreased the number of macrophages bound to EC and to ICAM-1 protein. Quantitative PCR showed that LPS increased the expression of ICAM-1 in both C166 and human RPE-choroid cultures, which was partially offset by MVS and zinc. MVS and zinc also mitigated LPS-induced ICAM-1 protein expression on Western blot analysis. Conclusions. Treatment with AREDS MVS and zinc may affect both angiogenesis and endothelial-macrophage interactions. These results suggest that AREDS vitamins and zinc ions may slow the progression of AMD, in part through the attenuation of EC activation. PMID:22247465

Cooperative Assembly of Magneto-Nanovesicles with Tunable Wall Thickness and Permeability for MRI-Guided Drug Delivery.

PubMed

Yang, Kuikun; Liu, Yijing; Liu, Yi; Zhang, Qian; Kong, Chuncai; Yi, Chenglin; Zhou, Zijian; Wang, Zhantong; Zhang, Guofeng; Zhang, Yang; Khashab, Niveen M; Chen, Xiaoyuan; Nie, Zhihong

2018-04-04

This article describes the fabrication of nanosized magneto-vesicles (MVs) comprising tunable layers of densely packed superparamagnetic iron oxide nanoparticles (SPIONs) in membranes via cooperative assembly of polymer-tethered SPIONs and free poly(styrene)- b-poly(acrylic acid) (PS- b-PAA). The membrane thickness of MVs could be well controlled from 9.8 to 93.2 nm by varying the weight ratio of PS- b-PAA to SPIONs. The increase in membrane thickness was accompanied by the transition from monolayer MVs, to double-layered MVs and to multilayered MVs (MuMVs). This can be attributed to the variation in the hydrophobic/hydrophilic balance of polymer-grafted SPIONs upon the insertion and binding of PS- b-PAA onto the surface of nanoparticles. Therapeutic agents can be efficiently encapsulated in the hollow cavity of MVs and the release of payload can be tuned by varying the membrane thickness of nanovesicles. Due to the high packing density of SPIONs, the MuMVs showed the highest magnetization and transverse relaxivity rate ( r 2 ) in magnetic resonance imaging (MRI) among these MVs and individual SPIONs. Upon intravenous injection, doxorubicin-loaded MuMVs conjugated with RGD peptides could be effectively enriched at tumor sites due to synergetic effect of magnetic and active targeting. As a result, they exhibited drastically enhanced signal in MRI, improved tumor delivery efficiency of drugs as well as enhanced antitumor efficacy, compared with groups with only magnetic or active targeting strategy. The unique nanoplatform may find applications in effective disease control by delivering imaging and therapy to organs/tissues that are not readily accessible by conventional delivery vehicles.

Effects of antioxidant components of AREDS vitamins and zinc ions on endothelial cell activation: implications for macular degeneration.

PubMed

Zeng, Shemin; Hernández, Jasmine; Mullins, Robert F

2012-02-01

To investigate whether the benefit of Age-Related Eye Disease Study (AREDS) formula multivitamins and zinc in the progression of age-related macular degeneration (AMD) may occur through inhibiting inflammatory events in the choroid. Mouse C166 endothelial cells (ECs) and, for some experiments, human retinal pigment epithelium (RPE)-choroid organ cultures were treated with AREDS multivitamin solution (MVS) or ZnCl(2). The cytotoxicity of MVS was evaluated using a lactate dehydrogenase colorimetric assay. Cell motility was assessed using a scratch assay. Macrophage adhesion to EC monolayers or ICAM-1 protein was determined after MVS and zinc treatment and with or without lipopolysaccharide (LPS). Quantitative reverse transcription PCR and Western blot analysis were used to determine the effects of MVS on the expression of proinflammatory molecules in treated and untreated cells. AREDS MVS and zinc did not affect C166 EC viability until the 56th hour after treatment. Scratch assays showed partial inhibition of MVS and zinc on EC migration. In cell adhesion assays, MVS and zinc decreased the number of macrophages bound to EC and to ICAM-1 protein. Quantitative PCR showed that LPS increased the expression of ICAM-1 in both C166 and human RPE-choroid cultures, which was partially offset by MVS and zinc. MVS and zinc also mitigated LPS-induced ICAM-1 protein expression on Western blot analysis. Treatment with AREDS MVS and zinc may affect both angiogenesis and endothelial-macrophage interactions. These results suggest that AREDS vitamins and zinc ions may slow the progression of AMD, in part through the attenuation of EC activation.

Entry of Porphyromonas gingivalis outer membrane vesicles into epithelial cells causes cellular functional impairment.

PubMed

Furuta, Nobumichi; Takeuchi, Hiroki; Amano, Atsuo

2009-11-01

Porphyromonas gingivalis, a periodontal pathogen, secretes outer membrane vesicles (MVs) that contain major virulence factors, including proteases termed gingipains (Arg-gingipain [Rgp] and Lys-gingipain [Kgp]). We recently showed that P. gingivalis MVs swiftly enter host epithelial cells via an endocytosis pathway and are finally sorted to lytic compartments. However, it remains unknown whether MV entry impairs cellular function. Herein, we analyzed cellular functional impairment following entry of P. gingivalis into epithelial cells, including HeLa and immortalized human gingival epithelial (IHGE) cells. After being taken up by endocytic vacuoles, MVs degraded the cellular transferrin receptor (TfR) and integrin-related signaling molecules, such as paxillin and focal adhesion kinase (FAK), which resulted in depletion of intracellular transferrin and inhibition of cellular migration. Few Rgp-null MVs entered the cells, and these negligibly degraded TfR, whereas paxillin and FAK degradation was significant. In contrast, Kgp-null MVs clearly entered the cells and degraded TfR, while they scarcely degraded paxillin and FAK. In addition, both wild-type and Kgp-null MVs significantly impaired cellular migration, whereas the effect of Rgp-null MVs was limited. Our findings suggest that, following entry of P. gingivalis MVs into host cells, MV-associated gingipains degrade cellular functional molecules such as TfR and paxillin/FAK, resulting in cellular impairment, indicating that P. gingivalis MVs are potent vehicles for transmission of virulence factors into host cells and are involved in the etiology of periodontitis.

Entry of Porphyromonas gingivalis Outer Membrane Vesicles into Epithelial Cells Causes Cellular Functional Impairment▿

PubMed Central

Furuta, Nobumichi; Takeuchi, Hiroki; Amano, Atsuo

2009-01-01

Porphyromonas gingivalis, a periodontal pathogen, secretes outer membrane vesicles (MVs) that contain major virulence factors, including proteases termed gingipains (Arg-gingipain [Rgp] and Lys-gingipain [Kgp]). We recently showed that P. gingivalis MVs swiftly enter host epithelial cells via an endocytosis pathway and are finally sorted to lytic compartments. However, it remains unknown whether MV entry impairs cellular function. Herein, we analyzed cellular functional impairment following entry of P. gingivalis into epithelial cells, including HeLa and immortalized human gingival epithelial (IHGE) cells. After being taken up by endocytic vacuoles, MVs degraded the cellular transferrin receptor (TfR) and integrin-related signaling molecules, such as paxillin and focal adhesion kinase (FAK), which resulted in depletion of intracellular transferrin and inhibition of cellular migration. Few Rgp-null MVs entered the cells, and these negligibly degraded TfR, whereas paxillin and FAK degradation was significant. In contrast, Kgp-null MVs clearly entered the cells and degraded TfR, while they scarcely degraded paxillin and FAK. In addition, both wild-type and Kgp-null MVs significantly impaired cellular migration, whereas the effect of Rgp-null MVs was limited. Our findings suggest that, following entry of P. gingivalis MVs into host cells, MV-associated gingipains degrade cellular functional molecules such as TfR and paxillin/FAK, resulting in cellular impairment, indicating that P. gingivalis MVs are potent vehicles for transmission of virulence factors into host cells and are involved in the etiology of periodontitis. PMID:19737899

Microvesicles Derived from Mesenchymal Stem Cells Enhance Survival in a Lethal Model of Acute Kidney Injury

PubMed Central

Bruno, Stefania; Grange, Cristina; Collino, Federica; Deregibus, Maria Chiara; Cantaluppi, Vincenzo; Biancone, Luigi; Tetta, Ciro; Camussi, Giovanni

2012-01-01

Several studies demonstrated that treatment with mesenchymal stem cells (MSCs) reduces cisplatin mortality in mice. Microvesicles (MVs) released from MSCs were previously shown to favor renal repair in non lethal toxic and ischemic acute renal injury (AKI). In the present study we investigated the effects of MSC-derived MVs in SCID mice survival in lethal cisplatin-induced AKI. Moreover, we evaluated in vitro the effect of MVs on cisplatin-induced apoptosis of human renal tubular epithelial cells and the molecular mechanisms involved. Two different regimens of MV injection were used. The single administration of MVs ameliorated renal function and morphology, and improved survival but did not prevent chronic tubular injury and persistent increase in BUN and creatinine. Multiple injections of MVs further decreased mortality and at day 21 surviving mice showed normal histology and renal function. The mechanism of protection was mainly ascribed to an anti-apoptotic effect of MVs. In vitro studies demonstrated that MVs up-regulated in cisplatin-treated human tubular epithelial cells anti-apoptotic genes, such as Bcl-xL, Bcl2 and BIRC8 and down-regulated genes that have a central role in the execution-phase of cell apoptosis such as Casp1, Casp8 and LTA. In conclusion, MVs released from MSCs were found to exert a pro-survival effect on renal cells in vitro and in vivo, suggesting that MVs may contribute to renal protection conferred by MSCs. PMID:22431999

Characteristics of erythrocyte-derived microvesicles and its relation with atherosclerosis.

PubMed

Li, Kai-Yin; Zheng, Lei; Wang, Qian; Hu, Yan-Wei

2016-12-01

Microvesicles are formed under many circumstances, especially in atheromatous plaques. Erythrocyte-derived microvesicles (ErMVs) have been proved to promote atherosclerosis by promoting hypercoagulation, mediating inflammation and inducing cell adhesion. Several clinical studies have reported potential roles of ErMVs in cardiovascular disease diagnosis, but the current understanding of ErMVs remains insufficient. In this paper, we will review current research on the formation and degradation of ErMVs and the possible effects of ErMVs in atherosclerosis, discuss potential clinical applications in cardiovascular disease, and hope to raise awareness of the relation with atherosclerosis. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Membrane Vesicles of Group B Streptococcus Disrupt Feto-Maternal Barrier Leading to Preterm Birth

PubMed Central

Sthanam, Lakshmi Kavitha; Srivastava, Rohit; Basu, Bhakti; Dutta, Suryendu; Sen, Shamik; Modi, Deepak

2016-01-01

Infection of the genitourinary tract with Group B Streptococcus (GBS), an opportunistic gram positive pathogen, is associated with premature rupture of amniotic membrane and preterm birth. In this work, we demonstrate that GBS produces membrane vesicles (MVs) in a serotype independent manner. These MVs are loaded with virulence factors including extracellular matrix degrading proteases and pore forming toxins. Mice chorio-decidual membranes challenged with MVs ex vivo resulted in extensive collagen degradation leading to loss of stiffness and mechanical weakening. MVs when instilled vaginally are capable of anterograde transport in mouse reproductive tract. Intra-amniotic injections of GBS MVs in mice led to upregulation of pro-inflammatory cytokines and inflammation mimicking features of chorio-amnionitis; it also led to apoptosis in the chorio-decidual tissue. Instillation of MVs in the amniotic sac also resulted in intrauterine fetal death and preterm delivery. Our findings suggest that GBS MVs can independently orchestrate events at the feto-maternal interface causing chorio-amnionitis and membrane damage leading to preterm birth or fetal death. PMID:27583406

Comparative performance of multiview stereoscopic and mammographic display modalities for breast lesion detection

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

Webb, Lincoln J.; Samei, Ehsan; Lo, Joseph Y.

2011-04-15

Purpose: Mammography is known to be one of the most difficult radiographic exams to interpret. Mammography has important limitations, including the superposition of normal tissue that can obscure a mass, chance alignment of normal tissue to mimic a true lesion and the inability to derive volumetric information. It has been shown that stereomammography can overcome these deficiencies by showing that layers of normal tissue lay at different depths. If standard stereomammography (i.e., a single stereoscopic pair consisting of two projection images) can significantly improve lesion detection, how will multiview stereoscopy (MVS), where many projection images are used, compare to mammography?more » The aim of this study was to assess the relative performance of MVS compared to mammography for breast mass detection. Methods: The MVS image sets consisted of the 25 raw projection images acquired over an arc of approximately 45 deg. using a Siemens prototype breast tomosynthesis system. The mammograms were acquired using a commercial Siemens FFDM system. The raw data were taken from both of these systems for 27 cases and realistic simulated mass lesions were added to duplicates of the 27 images at the same local contrast. The images with lesions (27 mammography and 27 MVS) and the images without lesions (27 mammography and 27 MVS) were then postprocessed to provide comparable and representative image appearance across the two modalities. All 108 image sets were shown to five full-time breast imaging radiologists in random order on a state-of-the-art stereoscopic display. The observers were asked to give a confidence rating for each image (0 for lesion definitely not present, 100 for lesion definitely present). The ratings were then compiled and processed using ROC and variance analysis. Results: The mean AUC for the five observers was 0.614{+-}0.055 for mammography and 0.778{+-}0.052 for multiview stereoscopy. The difference of 0.164{+-}0.065 was statistically significant with a p-value of 0.0148. Conclusions: The differences in the AUCs and the p-value suggest that multiview stereoscopy has a statistically significant advantage over mammography in the detection of simulated breast masses. This highlights the dominance of anatomical noise compared to quantum noise for breast mass detection. It also shows that significant lesion detection can be achieved with MVS without any of the artifacts associated with tomosynthesis.« less

On-Chip Supercapacitor Electrode Based On Polypyrrole Deposited Into Nanoporous Au Scaffold

NASA Astrophysics Data System (ADS)

Lu, P.; Ohlckers, P.; Chen, X. Y.

2016-11-01

On-chip supercapacitors hold the potential promise for serving as the energy storage units in integrated circuit system, due to their much higher energy density in comparison with conventional dielectric capacitors, high power density and long-term cycling stability. In this study, nanoporous Au (NP-Au) film on-chip was employed as the electrode scaffold to help increase the electrolyte-accessible area for active material. Pseudo-capacitive polypyrrole (PPY) with high theoretical capacitance was deposited into the NP-Au scaffold, to construct the tailored NP-Au/PPY hybrid on-chip electrode with improved areal capacitance. Half cell test in three- electrode system revealed the improved capacitor performance of nanoporous Au supported PPY electrode, compared to the densely packed PPY nanowire film electrode on planer Au substrate (Au/PPY). The areal capacitance of 37 mF/cm2∼10 mV/s, 32 mF/cm2∼50 mV/s, 28 mF/cm2∼100 mV/s, 16 mF/cm2∼500 mV/s, were offered by NP-Au/PPY. Also, the cycling performance was enhanced via using NP-Au scaffold. The developed NP-Au/PPY on-chip electrode demonstrated herein paves a feasible pathway to employ dealloying derived porous metal as the scaffold for improving both the energy density and cycling performance for supercapacitor electrodes.

Characterization of Induced Pluripotent Stem Cell Microvesicle Genesis, Morphology and Pluripotent Content

PubMed Central

Zhou, Jing; Ghoroghi, Shima; Benito-Martin, Alberto; Wu, Hao; Unachukwu, Uchenna John; Einbond, Linda Saxe; Guariglia, Sara; Peinado, Hector; Redenti, Stephen

2016-01-01

Microvesicles (MVs) are lipid bilayer-covered cell fragments that range in diameter from 30 nm–1uM and are released from all cell types. An increasing number of studies reveal that MVs contain microRNA, mRNA and protein that can be detected in the extracellular space. In this study, we characterized induced pluripotent stem cell (iPSC) MV genesis, content and fusion to retinal progenitor cells (RPCs) in vitro. Nanoparticle tracking revealed that iPSCs released approximately 2200 MVs cell/hour in the first 12 hrs with an average diameter of 122 nm. Electron and light microscopic analysis of iPSCs showed MV release via lipid bilayer budding. The mRNA content of iPSC MVs was characterized and revealed the presence of the transcription factors Oct-3/4, Nanog, Klf4, and C-Myc. The protein content of iPSCs MVs, detected by immunogold electron microscopy, revealed the presence of the Oct-3/4 and Nanog. Isolated iPSC MVs were shown to fuse with RPCs in vitro at multiple points along the plasma membrane. These findings demonstrate that the mRNA and protein cargo in iPSC MVs have established roles in maintenance of pluripotency. Building on this work, iPSC derived MVs may be shown to be involved in maintaining cellular pluripotency and may have application in regenerative strategies for neural tissue. PMID:26797168

Membrane vesicles nucleate mineralo-organic nanoparticles and induce carbonate apatite precipitation in human body fluids.

PubMed

Wu, Cheng-Yeu; Martel, Jan; Cheng, Wei-Yun; He, Chao-Chih; Ojcius, David M; Young, John D

2013-10-18

Recent studies indicate that membrane vesicles (MVs) secreted by various cells are associated with human diseases, including arthritis, atherosclerosis, cancer, and chronic kidney disease. The possibility that MVs may induce the formation of mineralo-organic nanoparticles (NPs) and ectopic calcification has not been investigated so far. Here, we isolated MVs ranging in size between 20 and 400 nm from human serum and FBS using ultracentrifugation and sucrose gradient centrifugation. The MV preparations consisted of phospholipid-bound vesicles containing the serum proteins albumin, fetuin-A, and apolipoprotein A1; the mineralization-associated enzyme alkaline phosphatase; and the exosome proteins TNFR1 and CD63. Notably, we observed that MVs induced mineral precipitation following inoculation and incubation in cell culture medium. The mineral precipitates consisted of round, mineralo-organic NPs containing carbonate hydroxyapatite, similar to previous descriptions of the so-called nanobacteria. Annexin V-immunogold staining revealed that the calcium-binding lipid phosphatidylserine (PS) was exposed on the external surface of serum MVs. Treatment of MVs with an anti-PS antibody significantly decreased their mineral seeding activity, suggesting that PS may provide nucleating sites for calcium phosphate deposition on the vesicles. These results indicate that MVs may represent nucleating agents that induce the formation of mineral NPs in body fluids. Given that mineralo-organic NPs represent precursors of calcification in vivo, our results suggest that MVs may initiate ectopic calcification in the human body.

The Protease Activated Receptor2 Promotes Rab5a Mediated Generation of Pro-metastatic Microvesicles.

PubMed

Das, Kaushik; Prasad, Ramesh; Roy, Sreetama; Mukherjee, Ashis; Sen, Prosenjit

2018-05-09

Metastasis, the hallmark of cancer propagation is attributed by the modification of phenotypic/functional behavior of cells to break attachment and migrate to distant body parts. Cancer cell-secreted microvesicles (MVs) contribute immensely in disease propagation. These nano-vesicles, generated from plasma membrane outward budding are taken up by nearby healthy cells thereby inducing phenotypic alterations in those recipient cells. Protease activated receptor 2 (PAR2), activated by trypsin, also contributes to cancer progression by increasing metastasis, angiogenesis etc. Here, we report that PAR2 activation promotes pro-metastatic MVs generation from human breast cancer cell line, MDA-MB-231. Rab5a, located at the plasma membrane plays vital roles in MVs biogenesis. We show that PAR2 stimulation promotes AKT phosphorylation which activates Rab5a by converting inactive Rab5a-GDP to active Rab5a-GTP. Active Rab5a polymerizes actin which critically regulates MVs shedding. Not only MVs generation, has this Rab5a activation also promoted cell migration and invasion. We reveal that Rab5a is over-expressed in human breast tumor specimen and contributes MVs generation in those patients. The involvement of p38 MAPK in MVs-induced cell metastasis has also been highlighted in the present study. Blockade of Rab5a activation can be a potential therapeutic approach to restrict MVs shedding and associated breast cancer metastasis.

Ada Compiler Validation Summary Report: Certificate Number: 880318W1. 09043 International Business Machines Corporation IBM Development System for the Ada Language, Version 2.1.0 IBM 4381 under VM/HPO, Host IBM 4381 under MVS/XA, Target

DTIC Science & Technology

1988-03-28

International Business Machines Corporation IBM Development System for the Ada Language, Version 2.1.0 IBM 4381 under VM/HPO, host IBM 4381 under MVS/XA, target...Program Office, AJPO 20. ABSTRACT (Continue on reverse side if necessary and identify by block number) International Business Machines Corporation, IBM...Standard ANSI/MIL-STD-1815A in the compiler listed in this declaration. I declare that International Business Machines Corporation is the owner of record

Variation sweep rate cyclic voltammetry on the capacitance electrode activated carbon/PVDF with polymer electrolyte

NASA Astrophysics Data System (ADS)

Rohmawati, L.; Setyarsih, W.; Nurjannah, T.

2018-03-01

Sweep rate of the process voltammetry cyclic characterization is very influential towards the electrode capacitance value, especially on activated carbon electrodes/PVDF. A simple method of this research by use a mixing for electrode activated carbon/10 wt. % PVDF and the separator is made of a polymer electrolyte (PVA/H3PO4) by a sol gel method. The prototype supercapacitor is made in the form of a sandwich with a separator placed between two electrodes. Electrodes and separators are arranged in layers at a pressure of 1500 psi, then heated at 50°C for 10 minutes. Next done cyclic voltammetry in a potential range of -1 V to 1 V with a sweep rate of 5 mV/s, 10 mV/s, 20 mV/s, 25 mV/s and 50 mV/s. This results of curves voltammogram is reversible, the most wide curve on the sweep rate of 5 mV/s and most narrow curve on a sweep rate of 50 mV/s. Supercapacitor capacitance values obtained by 86 F/g, 43 F/g, 21 F/g, 16 F/g, and 8 F/g.

From an 'ice-see' perspective: The current use, potential and limitations of Structure-from-Motion photogrammetry for cryospheric applications

NASA Astrophysics Data System (ADS)

Westoby, Matthew; Dunning, Stuart; Allan, Mark; Smith, Mark; Quincey, Duncan; Carrivick, Jonathan; Watson, C. Scott

2016-04-01

Structure-from-Motion with Multi-View Stereo (SfM-MVS) methods are rapidly becoming the tool of choice for geoscientists who require a relatively low-cost and viable alternative to traditional surveying technologies for characterising the form and short-term evolution of Earth surface landforms and landscapes. Uptake of SfM-MVS methods by workers in the cryospheric science community has been particularly rapid. The choice to use SfM-MVS has many logistical benefits which promote its adoption in remote glacial environments, namely the requirement for little more than a digital camera and proprietary or open-source software for topographic reconstruction, and a surveyed network of ground control to transform the resultant 3D models into a real-world co-ordinate system, if desired. Optionally, a dedicated aerial photography platform (e.g. kite, blimp, multirotor or fixed-wing UAV) may be used for initial photograph acquisition, which can facilitate glacier-scale observation and analysis. To date, cryospheric applications of SfM-MVS have included: the monitoring of glacier, moraine, and rock glacier movement; the evolution of ice cliffs on debris-covered glaciers; the reconstruction of ice-marginal or deglaciated topography; patch- and moraine-scale sedimentological characterisation; and the characterisation of glacier surfaces to monitor supraglacial drainage development or to inform energy balance modelling. This contribution will showcase existing applications and original data and discuss exciting potential opportunities and current limitations of the SfM-MVS method for the cryospheric sciences.

Measured values of coal mine stopping resistance

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

Oswald, N.; Prosser, B.; Ruckman, R.

2008-12-15

As coal mines become larger, the number of stoppings in the ventilation system increases. Each stopping represents a potential leakage path which must be adequately represented in the ventilation model. Stopping resistance can be calculated using two methods, the USBM method, used to determine a resistance for a single stopping, and the MVS technique, in which an average resistance is calculated for multiple stoppings. Through MVS data collected from ventilation surveys of different subsurface coal mines, average resistances for stoppings were determined for stopping in poor, average, good, and excellent conditions. The calculated average stoppings resistance were determined for concretemore » block and Kennedy stopping. Using the average stopping resistance, measured and calculated using the MVS method, provides a ventilation modeling tool which can be used to construct more accurate and useful ventilation models. 3 refs., 3 figs.« less

Glutaminase-containing microvesicles from HIV-1-infected macrophages and immune-activated microglia induce neurotoxicity.

PubMed

Wu, Beiqing; Huang, Yunlong; Braun, Alexander L; Tong, Zenghan; Zhao, Runze; Li, Yuju; Liu, Fang; Zheng, Jialin C

2015-11-06

HIV-1-infected and/or immune-activated microglia and macrophages are pivotal in the pathogenesis of HIV-1-associated neurocognitive disorders (HAND). Glutaminase, a metabolic enzyme that facilitates glutamate generation, is upregulated and may play a pathogenic role in HAND. Our previous studies have demonstrated that glutaminase is released to the extracellular fluid during HIV-1 infection and neuroinflammation. However, key molecular mechanisms that regulate glutaminase release remain unknown. Recent advances in understanding intercellular trafficking have identified microvesicles (MVs) as a novel means of shedding cellular contents. We posit that during HIV-1 infection and immune activation, microvesicles may mediate glutaminase release, generating excessive and neurotoxic levels of glutamate. MVs isolated through differential centrifugation from cell-free supernatants of monocyte-derived macrophages (MDM) and BV2 microglia cell lines were first confirmed in electron microscopy and immunoblotting. As expected, we found elevated number of MVs, glutaminase immunoreactivities, as well as glutaminase enzyme activity in the supernatants of HIV-1 infected MDM and lipopolysaccharide (LPS)-activated microglia when compared with controls. The elevated glutaminase was blocked by GW4869, a neutral sphingomyelinase inhibitor known to inhibit MVs release, suggesting a critical role of MVs in mediating glutaminase release. More importantly, MVs from HIV-1-infected MDM and LPS-activated microglia induced significant neuronal injury in rat cortical neuron cultures. The MV neurotoxicity was blocked by a glutaminase inhibitor or GW4869, suggesting that the neurotoxic potential of HIV-1-infected MDM and LPS-activated microglia is dependent on the glutaminase-containing MVs. These findings support MVs as a potential pathway/mechanism of excessive glutamate generation and neurotoxicity in HAND and therefore MVs may serve as a novel therapeutic target.

Infrared spectroscopic characterization of monocytic microvesicles (microparticles) released upon lipopolysaccharide stimulation.

PubMed

Lee, Joonsup; Wen, Beryl; Carter, Elizabeth A; Combes, Valery; Grau, Georges E R; Lay, Peter A

2017-07-01

Microvesicles (MVs) are involved in cell-cell interactions, including disease pathogenesis. Nondestructive Fourier-transform infrared (FTIR) spectra from MVs were assessed as a technique to provide new biochemical insights into a LPS-induced monocyte model of septic shock. FTIR spectroscopy provided a quick method to investigate relative differences in biomolecular content of different MV populations that was complementary to traditional semiquantitative omics approaches, with which it is difficult to provide information on relative changes between classes (proteins, lipids, nucleic acids, carbohydrates) or protein conformations. Time-dependent changes were detected in biomolecular contents of MVs and in the monocytes from which they were released. Differences in phosphatidylcholine and phosphatidylserine contents were observed in MVs released under stimulation, and higher relative concentrations of RNA and α-helical structured proteins were present in stimulated MVs compared with MVs from resting cells. FTIR spectra of stimulated monocytes displayed changes that were consistent with those observed in the corresponding MVs they released. LPS-stimulated monocytes had reduced concentrations of nucleic acids, α-helical structured proteins, and phosphatidylcholine compared with resting monocytes but had an increase in total lipids. FTIR spectra of MV biomolecular content will be important in shedding new light on the mechanisms of MVs and the different roles they play in physiology and disease pathogenesis.-Lee, J., Wen, B., Carter, E. A., Combes, V., Grau, G. E. R., Lay, P. A. Infrared spectroscopic characterization of monocytic microvesicles (microparticles) released upon lipopolysaccharide stimulation. © FASEB.

Membrane Vesicles Nucleate Mineralo-organic Nanoparticles and Induce Carbonate Apatite Precipitation in Human Body Fluids*

PubMed Central

Wu, Cheng-Yeu; Martel, Jan; Cheng, Wei-Yun; He, Chao-Chih; Ojcius, David M.; Young, John D.

2013-01-01

Recent studies indicate that membrane vesicles (MVs) secreted by various cells are associated with human diseases, including arthritis, atherosclerosis, cancer, and chronic kidney disease. The possibility that MVs may induce the formation of mineralo-organic nanoparticles (NPs) and ectopic calcification has not been investigated so far. Here, we isolated MVs ranging in size between 20 and 400 nm from human serum and FBS using ultracentrifugation and sucrose gradient centrifugation. The MV preparations consisted of phospholipid-bound vesicles containing the serum proteins albumin, fetuin-A, and apolipoprotein A1; the mineralization-associated enzyme alkaline phosphatase; and the exosome proteins TNFR1 and CD63. Notably, we observed that MVs induced mineral precipitation following inoculation and incubation in cell culture medium. The mineral precipitates consisted of round, mineralo-organic NPs containing carbonate hydroxyapatite, similar to previous descriptions of the so-called nanobacteria. Annexin V-immunogold staining revealed that the calcium-binding lipid phosphatidylserine (PS) was exposed on the external surface of serum MVs. Treatment of MVs with an anti-PS antibody significantly decreased their mineral seeding activity, suggesting that PS may provide nucleating sites for calcium phosphate deposition on the vesicles. These results indicate that MVs may represent nucleating agents that induce the formation of mineral NPs in body fluids. Given that mineralo-organic NPs represent precursors of calcification in vivo, our results suggest that MVs may initiate ectopic calcification in the human body. PMID:23990473

Signal Factors Secreted by 2D and Spheroid Mesenchymal Stem Cells and by Cocultures of Mesenchymal Stem Cells Derived Microvesicles and Retinal Photoreceptor Neurons

PubMed Central

Mao, Mao; Zhou, Liang

2017-01-01

We aim to identify levels of signal factors secreted by MSCs cultured in 2D monolayers (2D-MSCs), spheroids (spheroids MSCs), and cocultures of microvesicles (MVs) derived from 2D-MSCs or spheroid MSCs and retinal photoreceptor neurons. We seeded 2D-MSCs, spheroid MSCs, and cells derived from spheroids MSCs at equal numbers. MVs isolated from all 3 culture conditions were incubated with 661W cells. Levels of 51 signal factors in conditioned medium from those cultured conditions were quantified with bead-based assay. We found that IL-8, IL-6, and GROα were the top three most abundant signal factors. Moreover, compared to 2D-MSCs, levels of 11 cytokines and IL-2Rα were significantly increased in conditioned medium from spheroid MSCs. Finally, to test if enhanced expression of these factors reflects altered immunomodulating activities, we assessed the effect of 2D-MSC-MVs and 3D-MSC-MVs on CD14+ cell chemoattraction. Compared to 2D-MSC-MVs, 3D-MSC-MVs significantly decreased the chemotactic index of CD14+ cells. Our results suggest that spheroid culture conditions improve the ability of MSCs to selectively secrete signal factors. Moreover, 3D-MSC-MVs also possessed an enhanced capability to promote signal factors secretion compared to 2D-MSC-MVs and may possess enhanced immunomodulating activities and might be a better regenerative therapy for retinal degenerative diseases. PMID:28194184

A second generation experiment in fault-tolerant software

NASA Technical Reports Server (NTRS)

Knight, J. C.

1986-01-01

Information was collected on the efficacy of fault-tolerant software by conducting two large-scale controlled experiments. In the first, an empirical study of multi-version software (MVS) was conducted. The second experiment is an empirical evaluation of self testing as a method of error detection (STED). The purpose ot the MVS experiment was to obtain empirical measurement of the performance of multi-version systems. Twenty versions of a program were prepared at four different sites under reasonably realistic development conditions from the same specifications. The purpose of the STED experiment was to obtain empirical measurements of the performance of assertions in error detection. Eight versions of a program were modified to include assertions at two different sites under controlled conditions. The overall structure of the testing environment for the MVS experiment and its status are described. Work to date in the STED experiment is also presented.

Formation of Orthopoxvirus Cytoplasmic A-Type Inclusion Bodies and Embedding of Virions Are Dynamic Processes Requiring Microtubules

PubMed Central

Howard, Amanda R.

2012-01-01

In cells infected with some orthopoxviruses, numerous mature virions (MVs) become embedded within large, cytoplasmic A-type inclusions (ATIs) that can protect infectivity after cell lysis. ATIs are composed of an abundant viral protein called ATIp, which is truncated in orthopoxviruses such as vaccinia virus (VACV) that do not form ATIs. To study ATI formation and occlusion of MVs within ATIs, we used recombinant VACVs that express the cowpox full-length ATIp or we transfected plasmids encoding ATIp into cells infected with VACV, enabling ATI formation. ATI enlargement and MV embedment required continued protein synthesis and an intact microtubular network. For live imaging of ATIs and MVs, plasmids expressing mCherry fluorescent protein fused to ATIp were transfected into cells infected with VACV expressing the viral core protein A4 fused to yellow fluorescent protein. ATIs appeared as dynamic, mobile bodies that enlarged by multiple coalescence events, which could be prevented by disrupting microtubules. Coalescence of ATIs was confirmed in cells infected with cowpox virus. MVs were predominantly at the periphery of ATIs early in infection. We determined that coalescence contributed to the distribution of MVs within ATIs and that microtubule-disrupting drugs abrogated coalescence-mediated MV embedment. In addition, MVs were shown to move from viral factories at speeds consistent with microtubular transport to the peripheries of ATIs, whereas disruption of microtubules prevented such trafficking. The data indicate an important role for microtubules in the coalescence of ATIs into larger structures, transport of MVs to ATIs, and embedment of MVs within the ATI matrix. PMID:22438543

The German version of the Material Values Scale

PubMed Central

Müller, Astrid; Smits, Dirk J. M.; Claes, Laurence; Gefeller, Olaf; Hinz, Andreas; de Zwaan, Martina

2013-01-01

Aim: The Material Values Scale is an instrument to assess beliefs about the importance to own material things. This instrument originally consists of the three subscales: ‘centrality’, ‘success’, and ‘happiness’. The present study investigated the psychometric properties of the German version of the MVS (G-MVS). Method: A population-based sample of 2,295 adult Germans completed the questionnaire in order to investigate the factorial structure. To test construct validity, additional samples were gathered among patients with compulsive buying (N=52) and medical students (N=347) who also answered the Compulsive Buying Scale (CBS) and the Patient Health Questionnaire depression scale (PHQ-8). Results: In the German population-based sample we could not confirm the 3-factor model but rather suggest a 2-factor solution with a first collapsed factor ‘centrality/success’, and the second factor ’happiness’. Patients with compulsive buying showed the highest scores on the G-MVS. While G-MVS scores among compulsive buyers and medical students were significantly related to compulsive buying scores, the correlation between the G-MVS and the depression measure appeared substantially lower. We did not find any gender differences regarding materialism, neither in the population-based sample nor in the students’ or compulsive buyers’ samples. However, age was negatively related to G-MVS scores. Conclusion: Confirmatory factor analyses suggest a 2-factor model of the G-MVS. Overall, the results indicate the use of the G-MVS as a brief, psychometrically sound, and potentially valid measure for the assessment of material values. PMID:23802017

High-resolution proteomic and lipidomic analysis of exosomes and microvesicles from different cell sources

PubMed Central

Haraszti, Reka A.; Didiot, Marie-Cecile; Sapp, Ellen; Leszyk, John; Shaffer, Scott A.; Rockwell, Hannah E.; Gao, Fei; Narain, Niven R.; DiFiglia, Marian; Kiebish, Michael A.; Aronin, Neil; Khvorova, Anastasia

2016-01-01

Extracellular vesicles (EVs), including exosomes and microvesicles (MVs), are explored for use in diagnostics, therapeutics and drug delivery. However, little is known about the relationship of protein and lipid composition of EVs and their source cells. Here, we report high-resolution lipidomic and proteomic analyses of exosomes and MVs derived by differential ultracentrifugation from 3 different cell types: U87 glioblastoma cells, Huh7 hepatocellular carcinoma cells and human bone marrow-derived mesenchymal stem cells (MSCs). We identified 3,532 proteins and 1,961 lipid species in the screen. Exosomes differed from MVs in several different areas: (a) The protein patterns of exosomes were more likely different from their cells of origin than were the protein patterns of MVs; (b) The proteomes of U87 and Huh7 exosomes were similar to each other but different from the proteomes of MSC exosomes, whereas the lipidomes of Huh7 and MSC exosomes were similar to each other but different from the lipidomes of U87 exosomes; (c) exosomes exhibited proteins of extracellular matrix, heparin-binding, receptors, immune response and cell adhesion functions, whereas MVs were enriched in endoplasmic reticulum, proteasome and mitochondrial proteins. Exosomes and MVs also differed in their types of lipid contents. Enrichment in glycolipids and free fatty acids characterized exosomes, whereas enrichment in ceramides and sphingomyelins characterized MVs. Furthermore, Huh7 and MSC exosomes were specifically enriched in cardiolipins; U87 exosomes were enriched in sphingomyelins. This study comprehensively analyses the protein and lipid composition of exosomes, MVs and source cells in 3 different cell types. PMID:27863537

Integrated analysis of bacterial and microeukaryotic communities from differentially active mud volcanoes in the Gulf of Cadiz

NASA Astrophysics Data System (ADS)

Coelho, Francisco J. R. C.; Louvado, António; Domingues, Patrícia M.; Cleary, Daniel F. R.; Ferreira, Marina; Almeida, Adelaide; Cunha, Marina R.; Cunha, Ângela; Gomes, Newton C. M.

2016-10-01

The present study assesses the diversity and composition of sediment bacterial and microeukaryotic communities from deep-sea mud volcanoes (MVs) associated with strike-slip faults in the South-West Iberian Margin (SWIM). We used a 16S/18S rRNA gene based pyrosequencing approach to characterize and correlate the sediment bacterial and microeukaryotic communities from MVs with differing gas seep regimes and from an additional site with no apparent seeping activity. In general, our results showed significant compositional changes of bacterial and microeukaryotic communities in sampling sites with different seepage regimes. Sediment bacterial communities were enriched with Methylococcales (putative methanotrophs) but had lower abundances of Rhodospirillales, Nitrospirales and SAR202 in the more active MVs. Within microeukaryotic communities, members of the Lobosa (lobose amoebae) were enriched in more active MVs. We also showed a strong correlation between Methylococcales populations and lobose amoeba in active MVs. This study provides baseline information on the diversity and composition of bacterial and microeukaryotic communities in deep-sea MVs associated with strike-slip faults.

Integrated analysis of bacterial and microeukaryotic communities from differentially active mud volcanoes in the Gulf of Cadiz

PubMed Central

Coelho, Francisco J. R. C.; Louvado, António; Domingues, Patrícia M.; Cleary, Daniel F. R.; Ferreira, Marina; Almeida, Adelaide; Cunha, Marina R.; Cunha, Ângela; Gomes, Newton C. M.

2016-01-01

The present study assesses the diversity and composition of sediment bacterial and microeukaryotic communities from deep-sea mud volcanoes (MVs) associated with strike-slip faults in the South-West Iberian Margin (SWIM). We used a 16S/18S rRNA gene based pyrosequencing approach to characterize and correlate the sediment bacterial and microeukaryotic communities from MVs with differing gas seep regimes and from an additional site with no apparent seeping activity. In general, our results showed significant compositional changes of bacterial and microeukaryotic communities in sampling sites with different seepage regimes. Sediment bacterial communities were enriched with Methylococcales (putative methanotrophs) but had lower abundances of Rhodospirillales, Nitrospirales and SAR202 in the more active MVs. Within microeukaryotic communities, members of the Lobosa (lobose amoebae) were enriched in more active MVs. We also showed a strong correlation between Methylococcales populations and lobose amoeba in active MVs. This study provides baseline information on the diversity and composition of bacterial and microeukaryotic communities in deep-sea MVs associated with strike-slip faults. PMID:27762306

Integrated analysis of bacterial and microeukaryotic communities from differentially active mud volcanoes in the Gulf of Cadiz.

PubMed

Coelho, Francisco J R C; Louvado, António; Domingues, Patrícia M; Cleary, Daniel F R; Ferreira, Marina; Almeida, Adelaide; Cunha, Marina R; Cunha, Ângela; Gomes, Newton C M

2016-10-20

The present study assesses the diversity and composition of sediment bacterial and microeukaryotic communities from deep-sea mud volcanoes (MVs) associated with strike-slip faults in the South-West Iberian Margin (SWIM). We used a 16S/18S rRNA gene based pyrosequencing approach to characterize and correlate the sediment bacterial and microeukaryotic communities from MVs with differing gas seep regimes and from an additional site with no apparent seeping activity. In general, our results showed significant compositional changes of bacterial and microeukaryotic communities in sampling sites with different seepage regimes. Sediment bacterial communities were enriched with Methylococcales (putative methanotrophs) but had lower abundances of Rhodospirillales, Nitrospirales and SAR202 in the more active MVs. Within microeukaryotic communities, members of the Lobosa (lobose amoebae) were enriched in more active MVs. We also showed a strong correlation between Methylococcales populations and lobose amoeba in active MVs. This study provides baseline information on the diversity and composition of bacterial and microeukaryotic communities in deep-sea MVs associated with strike-slip faults.

Cheap, High-Performance, and Wearable Mn Oxide Supercapacitors with Urea-LiClO4 Based Gel Electrolytes.

PubMed

Deng, Ming-Jay; Chen, Kai-Wen; Che, Yo-Cheng; Wang, I-Ju; Lin, Chih-Ming; Chen, Jin-Ming; Lu, Kueih-Tzu; Liao, Yen-Fa; Ishii, Hirofumi

2017-01-11

Here we report a simple, scalable, and low-cost method to enhance the electrochemical properties of Mn oxide electrodes for highly efficient and flexible symmetrical supercapacitors. The method involving printing on a printer, pencil-drawing, and electrodeposition is established to fabricate Mn oxide/Ni-nanotube/graphite/paper hybrid electrodes operating with a low-cost, novel urea-LiClO 4 /PVA as gel electrolyte for flexible solid-state supercapacitor (FSSC) devices. The Mn oxide nanofiber/Ni-nanotube/graphite/paper (MNNGP) electrodes in urea-LiClO 4 /PVA gel electrolyte show specific capacitance (C sp ) 960 F/g in voltage region 0.8 V at 5 mV/s and exhibit excellent rates of capacitance retention more than 85% after 5000 cycles. Moreover, the electrochemical behavior of the MNNGP electrodes in urea-LiClO 4 /PVA at operating temperatures 27-110 °C was investigated; the results show that the MNNGP electrodes in urea-LiClO 4 /PVA exhibit outstanding performance (1100 F/g), even at 90 °C. The assembled FSSC devices based on the MNNGP electrodes in urea-LiClO 4 /PVA exhibit great C sp (380 F/g in potential region of 2.0 V at 5 mV/s, exhibiting superior energy density 211.1 W h/kg) and great cycle stability (less than 15% loss after 5000 cycles at 25 mV/s). The oxidation-state change was examined by in situ X-ray absorption spectroscopy. FSSC devices would open new opportunities in developing novel portable, wearable, and roll-up electric devices owing to the cheap, high-performance, wide range of operating temperature, and simple procedures for large-area fabrication.

Supercapacitors based on nitrogen-doped reduced graphene oxide and borocarbonitrides

NASA Astrophysics Data System (ADS)

Gopalakrishnan, K.; Moses, Kota; Govindaraj, A.; Rao, C. N. R.

2013-12-01

Nitrogen-doped reduced graphene oxide (RGO) samples with different nitrogen content, prepared by two different methods, as well as nitrogen-doped few-layer graphene have been investigated as supercapacitor electrodes. Two electrode measurements have been carried out both in aqueous (6M KOH) and in ionic liquid media. Nitrogen-doped reduced graphene oxides exhibit satisfactory specific capacitance, the values reaching 126F/g at a scan rate of 10mV/s in aqueous medium. Besides providing supercapacitor characteristics, the study has shown the nitrogen content and surface area to be important factors. High surface-area borocarbonitrides, BxCyNz, prepared by the urea route appear to be excellent supercapacitor electrode materials. Thus, BC4.5N exhibits a specific capacitance of 169F/g at a scan rate of 10mV/s in aqueous medium. In an ionic liquid medium, nitrogen-doped RGO and BC4.5N exhibit specific capacitance values of 258F/g and 240F/g at a scan rate of 5mV/s. The ionic liquid enables a larger operating voltage range of 0.0-2.5V compared to 0.0-1V in aqueous medium.

Macrofaunal assemblages from mud volcanoes in the Gulf of Cadiz: abundance, biodiversity and diversity partitioning across spatial scales

NASA Astrophysics Data System (ADS)

Cunha, M. R.; Rodrigues, C. F.; Génio, L.; Hilário, A.; Ravara, A.; Pfannkuche, O.

2012-12-01

The Gulf of Cadiz is an extensive seepage area in the South Iberian Margin (NE Atlantic) encompassing over 40 mud volcanoes (MVs) at depths ranging from 200 to 4000 m. The area has a long geologic history and a central biogeographic location with a complex circulation assuring oceanographic connectivity with the Mediterranean Sea, Equatorial and Northern Atlantic regions. The geodynamics of the region promotes a notorious diversity in the seep regime despite the relatively low fluxes of hydrocarbon-rich gases. We analyse quantitative samples taken during the cruises TTR14, TTR15 and MSM01-03 in seven mud volcanoes grouped into Shallow MVs (Mercator: 350 m, Kidd: 500 m, Meknès: 700 m) and Deep MVs (Captain Arutyunov: 1300 m, Carlos Ribeiro: 2200 m, Bonjardim: 3000 m, Porto: 3900 m) and two additional reference sites (ca. 550 m). Macrofauna (retained by a 500 μm sieve) was identified to species level whenever possible. The samples yielded modest abundances (70-1567 ind. per 0.25 m2) but a number of species among the highest ever reported for cold seeps. Among the 366 recorded species, 22 were symbiont-hosting bivalves (Thyasiridae, Vesicomyidae, Solemyidae) and tubeworms (Siboglinidae). The multivariate analyses indicated significant differences between Shallow and Deep MVs: The environmental conditions at the Shallow MVs makes them highly permeable to the penetration of background fauna leading to high diversity of the attendant assemblages (H': 2.92-3.94; ES(100): 28.3-45.0; J': 0.685-0.881). The Deep MVs showed, in general, contrasting features but were more heterogeneous (H': 1.41-3.06; ES(100): 10.5-30.5; J': 0.340-0.852) and often dominated by one or more siboglinid species. The rarefaction curves confirmed the differences in biodiversity of Deep and Shallow MVs as well as the approximation of the latter to the reference sites. The Bray-Curtis dissimilarity demonstrated the high β-diversity of the assemblages, especially in pairwise comparisons involving samples from the deeper MVs. Diversity partitioning assessed for species richness, Hurlbert's expected number of species and Shannon-Wiener index confirmed the high β-diversity across different spatial scales (within MVs, between MVs, between Deep and Shallow MVs). We suggest that historical and contemporary factors with differential synergies at different depths contribute to the high α-, β- and γ-diversity of the mud volcano faunal assemblages in the Gulf of Cadiz.

Role of Platelet-Derived Microvesicles As Crosstalk Mediators in Atherothrombosis and Future Pharmacology Targets: A Link between Inflammation, Atherosclerosis, and Thrombosis

PubMed Central

Badimon, Lina; Suades, Rosa; Fuentes, Eduardo; Palomo, Iván; Padró, Teresa

2016-01-01

Reports in the last decade have suggested that the role of platelets in atherosclerosis and its thrombotic complications may be mediated, in part, by local secretion of platelet-derived microvesicles (pMVs), small cell blebs released during the platelet activation process. MVs are the most abundant cell-derived microvesicle subtype in the circulation. High concentrations of circulating MVs have been reported in patients with atherosclerosis, acute vascular syndromes, and/or diabetes mellitus, suggesting a potential correlation between the quantity of microvesicles and the clinical severity of the atherosclerotic disease. pMVs are considered to be biomarkers of disease but new information indicates that pMVs are also involved in signaling functions. pMVs evoke or promote haemostatic and inflammatory responses, neovascularization, cell survival, and apoptosis, processes involved in the pathophysiology of cardiovascular disease. This review is focused on the complex cross-talk between platelet-derived microvesicles, inflammatory cells and vascular elements and their relevance in the development of the atherosclerotic disease and its clinical outcomes, providing an updated state-of-the art of pMV involvement in atherothrombosis and pMV potential use as therapeutic agent influencing cardiovascular biomedicine in the future. PMID:27630570

Extracellular Vesicles as Therapeutic Tools in Cardiovascular Diseases

PubMed Central

Fleury, Audrey; Martinez, Maria Carmen; Le Lay, Soazig

2014-01-01

Extracellular vesicles (EVs), including microvesicles (MVs) and exosomes, are small vesicles secreted from a wide variety of cells. Whereas MVs are particles released by the outward budding of the plasma membrane, exosomes are derived from endocytic compartments. Secretion of EVs can be enhanced by specific stimuli, and increased plasma circulating levels of EVs have been correlated with pathophysiological situations. MVs, already present in the blood of healthy individuals, are considerably elevated in several cardiovascular diseases associated with inflammation, suggesting that they can mediate deleterious effects such as endothelial dysfunction or thrombosis. Nonetheless, very recent studies also demonstrate that MVs may act as biological information vectors transferring proteins or genetic material to maintain cell homeostasis, favor cell repair, or even promote angiogenesis. Additionally, exosomes have also been shown to have pro-angiogenic and cardio-protective properties. These beneficial effects, therefore, reveal the potential therapeutical use of EVs in the field of cardiovascular medicine and regenerative therapy. In this review, we will provide an update of cellular processes modulated by EVs of specific interest in the treatment of cardiovascular pathologies. A special focus will be made on the morphogen sonic hedgehog (Shh) associated with EVs (EVsShh+), which have been shown to mediate many pro-angiogenic effects. In addition to offer a potential source of cardiovascular markers, therapeutical potential of EVs reveal exciting opportunities to deliver specific agents by non-immunogenic means to cardiovascular system. PMID:25136343

Protective effects of circulating microvesicles derived from myocardial ischemic rats on apoptosis of cardiomyocytes in myocardial ischemia/reperfusion injury.

PubMed

Wang, Yao; Wei, Su; Wang, Yi-Lu; Liu, Miao; Shang, Man; Zhang, Qi; Wu, Yan-Na; Liu, Ming-Lin; Song, Jun-Qiu; Liu, Yan-Xia

2017-08-15

To investigate the effects of circulating microvesicles derived from myocardial ischemia (I-MVs) on apoptosis in myocardial ischemia/reperfusion (I/R) injury in rats. I-MVs from rats undergoing myocardial left anterior descending (LAD) coronary artery ligation were isolated by ultracentrifugation from circulating blood and characterized by flow cytometry. I-MVs were administered intravenously (4.8 mg/kg) at 5 min before reperfusion procedure in I/R injury model which was induced by 30-min of ischemia and 120-min of reperfusion of LAD in rats. Treatment with I-MVssignificantly reduced the size of myocardial infarction, the activities of serum CK-MB and LDH, and the number of apoptotic cardiomyocytes. The activities of caspase 3, caspase 9 and caspase 12 in myocardium were also decreased significantly with I-MVs treatment. Moreover, the expression of Bax was decreased but Bcl-2 was increased. The expression of glucose regulated protein 78 (GRP78), sarco/endoplasmic reticulum Ca 2+ -ATPase 2 (SERCA2) and phosphorylated phospholamban (p-PLB) were increased after being treated with I-MVs. I-MVs could protect hearts from I/R injury in rats through SERCA2 and p-PLB of calcium regulatory proteins to alleviate intrinsic myocardial apoptosis including mitochondrial and endoplasmic reticulum pathways.

Immunomodulatory role for membrane vesicles released by THP-1 macrophages and respiratory pathogens during macrophage infection.

PubMed

Volgers, Charlotte; Benedikter, Birke J; Grauls, Gert E; Savelkoul, Paul H M; Stassen, Frank R M

2017-11-13

During infection, inflammation is partially driven by the release of mediators which facilitate intercellular communication. Amongst these mediators are small membrane vesicles (MVs) that can be released by both host cells and Gram-negative and -positive bacteria. Bacterial membrane vesicles are known to exert immuno-modulatory and -stimulatory actions. Moreover, it has been proposed that host cell-derived vesicles, released during infection, also have immunostimulatory properties. In this study, we assessed the release and activity of host cell-derived and bacterial MVs during the first hours following infection of THP-1 macrophages with the common respiratory pathogens non-typeable Haemophilus influenzae, Moraxella catarrhalis, Streptococcus pneumoniae, and Pseudomonas aeruginosa. Using a combination of flow cytometry, tunable resistive pulse sensing (TRPS)-based analysis and electron microscopy, we demonstrated that the release of MVs occurs by both host cells and bacteria during infection. MVs released during infection and bacterial culture were found to induce a strong pro-inflammatory response by naive THP-1 macrophages. Yet, these MVs were also found to induce tolerance of host cells to secondary immunogenic stimuli and to enhance bacterial adherence and the number of intracellular bacteria. Bacterial MVs may play a dual role during infection, as they can both trigger and dampen immune responses thereby contributing to immune defence and bacterial survival.

Systematic Review of the Epidemiology and Natural History of the Metabolic Vascular Syndrome and its Coincidence with Type 2 Diabetes Mellitus and Cardiovascular Diseases in Different European Countries.

PubMed

Kwasny, Caroline; Manuwald, Ulf; Kugler, Joachim; Rothe, Ulrike

2018-03-01

The objectives of this systematic review were to estimate the incidence, prevalence and natural history of the metabolic (vascular) syndrome (MVS) among adults in different European countries. Furthermore, we assessed its co-incidence with type 2 diabetes (T2DM) and cardiovascular diseases (CVD). PubMed, MedLine, and EMBASE (via Ovid) were searched for relevant studies. After reading 116 full-text articles to find eligible ones, 66 publications met our inclusion criteria. Data for the incidence are based on a study from Portugal, in which the incidence rate for the MVS was 47.2/1000 person-years. Prevalence varied strongly depending on country and definition. The lowest was found in the United Kingdom (3%), the highest in Finland (71.7%). No article that deals with the natural history of the MVS was found. Considering the co-existence of MVS and T2DM, it ranged between 2% (United Kingdom) and 74.4% (Spain). The co-occurrence of MVS and CVD ranged from 2.8% (Italy) up to 52% (Netherlands). Coronary heart disease (CHD) varied between 1.2% and 44.2%. With regard to peripheral artery disease (PAD), values between 3.3% and 59.8% were found. Due to the many different definitions of the MVS, a comparison is very difficult. Overall prevalence ranged between 3% and 71.7% depending on definition, age, and country. An association between MVS and T2DM as well as several CVD can be assumed. © Georg Thieme Verlag KG Stuttgart · New York.

Origin of lipid biomarkers in mud volcanoes from the Alboran Sea, western Mediterranean

NASA Astrophysics Data System (ADS)

López-Rodríguez, C.; Stadnitskaia, A.; De Lange, G. J.; Martínez-Ruíz, F.; Comas, M.; Sinninghe Damsté, J. S.

2013-11-01

Mud volcanoes (MVs) are the most prominent indicators of active methane/hydrocarbon venting at the seafloor on both passive and active continental margins. Their occurrence in the Western Mediterranean is patent at the West Alboran Basin, where numerous MVs develop overlaying a major sedimentary depocenter containing overpressured shales. Although some of these MVs have been studied, the detailed biogeochemistry of expelled mud so far has not been examined in detail. This work provides the first results on the composition and origin of organic matter, Anaerobic Oxidation of Methane (AOM) processes and general characteristics on MV dynamics using lipid biomarkers as the main tool. Lipid biomarker analysis was performed on MV expelled material (mud breccias) and interbedded hemipelagic sediments from Perejil, Kalinin and Schneider's Heart MVs located in the northwest margin of the Alboran Sea. The n-alkane-distributions and n-alkane-derived indices (CPI and ACL), in combination with the epimerization degree of hopanes (22S/(22S + 22R)) indicate that all studied mud breccia have a similar biomarker composition consisting of mainly thermally immature organic matter with an admixture of petroleum-derived compounds. This concordant composition indicates that common source strata must feed all three studied MVs. The past or present AOM activity was established using lipid biomarkers specific for anaerobic methanotropic archaea (irregular isoprenoids and DGDs) and the depleted carbon isotope composition (δ13C) of crocetane/phytane. The presence of these lipid biomarkers, together with the low amounts of detected GDGTs, is consistent with the dominance of anaerobic methanotrophs of the ANME-2 over ANME-1, at least in mud breccia from Perejil MVs. In contrast, the scarce presence or lack of these AOM-related lipid biomarkers in sediments from Kalinin and Schneider's Heart MVs, suggest no recent active methane seepage has occurred at these sites. Moreover, the observed methane concentrations support the current activity of Perejil MV, and the very low methane seepage activity in Kalinin and Schneider's Heart MVs.

Hyperplasia of Pericytes Is One of the Main Characteristics of Microvascular Architecture in Malignant Glioma

PubMed Central

Sun, Huiqin; Guo, Deyu; Su, Yongping; Yu, Dongmei; Wang, Qingliang; Wang, Tao; Zhou, Qing; Ran, Xinze; Zou, Zhongmin

2014-01-01

Objectives To investigate the role of pericytes in constructing the malformed microvessels (MVs) and participating microvascular architecture heterogeneity of glioma. Methods Forty human glioma tissue samples (WHO grade II-IV) were included in present study. Observation of blood vessel patterns, quantitative analysis of endothelial cells (ECs)- and pericyte-labeled MVs and comparison between malignant grades based on single- or double-immunohistochemical staining. The MV number density (MVND), microvascular pericyte number density (MPND), and microvascular pericyte area density (MPAD) were calculated. The expression of PDGFβ was also scored after immunostaining. Results In grade II glioma, most of tumor MVs were the thin-wall CD34+ vessels with near normal morphology. In addition to thin-wall CD34+ MVs, more thick-wall MVs were found in grade III glioma, which often showed α-SMA positive. Most of MVs in grade IV glioma were in the form of plexus, curled cell cords and glomeruloid microvascular proliferation while the α-SMA+ cells were the main components. The MVs usually showed disordered arrangement, loose connection and active cell proliferation as shown by Ki67 and α-SMA coexpression. With the increase of glioma grades, the α-SMA+ MVND, CD34+ MVND and MPND were significantly augmented although the increase of CD34+ MVND but not MPAD was statistically insignificant between grade III and IV. It was interesting that some vessel-like structures only consist of α-SMA+ cells, assuming the guiding role of pericytes in angiogenesis. The expression level of PDGFβ was upregulated and directly correlated with the MPND in different glioma grades. Conclusion Hyperplasia of pericytes was one of the significant characteristics of malignant glioma and locally proliferated pericytes were the main constituent of MVs in high grade glioma. The pathological characteristics of pericytes could be used as indexes of malignant grades of glioma. PMID:25478951

Shedding of Microvesicles from Microglia Contributes to the Effects Induced by Metabotropic Glutamate Receptor 5 Activation on Neuronal Death.

PubMed

Beneventano, Martina; Spampinato, Simona F; Merlo, Sara; Chisari, Mariangela; Platania, Paola; Ragusa, Marco; Purrello, Michele; Nicoletti, Ferdinando; Sortino, Maria Angela

2017-01-01

Metabotropic glutamate (mGlu) receptor 5 is involved in neuroinflammation and has been shown to mediate reduced inflammation and neurotoxicity and to modify microglia polarization. On the other hand, blockade of mGlu5 receptor results in inhibition of microglia activation. To dissect this controversy, we investigated whether microvesicles (MVs) released from microglia BV2 cells could contribute to the communication between microglia and neurons and whether this interaction was modulated by mGlu5 receptor. Activation of purinergic ionotropic P2X7 receptor with the stable ATP analog benzoyl-ATP (100 μM) caused rapid MVs shedding from BV2 cells. Ionic currents through P2X7 receptor increased in BV2 cells pretreated for 24 h with the mGlu5 receptor agonist CHPG (200 μM) as by patch-clamp recording. This increase was blunted when microglia cells were activated by exposure to lipopolysaccharide (LPS; 0.1 μg/ml for 6 h). Accordingly, a greater amount of MVs formed after CHPG treatment, an effect prevented by the mGlu5 receptor antagonist MTEP (100 μM), as measured by expression of flotillin, a membrane protein enriched in MVs. Transferred MVs were internalized by SH-SY5Y neurons where they did not modify neuronal death induced by a low concentration of rotenone (0.1 μM for 24 h), but significantly increased rotenone neurotoxicity when shed from CHPG-treated BV2 cells. miR146a was increased in CHPG-treated MVs, an effect concealed in MVs from LPS-activated BV2 cells that showed per se an increase in miRNA146a levels. The present data support a role for microglia-shed MVs in mGlu5-mediated modulation of neuronal death and identify miRNAs as potential critical mediators of this interaction.

Shedding of Microvesicles from Microglia Contributes to the Effects Induced by Metabotropic Glutamate Receptor 5 Activation on Neuronal Death

PubMed Central

Beneventano, Martina; Spampinato, Simona F.; Merlo, Sara; Chisari, Mariangela; Platania, Paola; Ragusa, Marco; Purrello, Michele; Nicoletti, Ferdinando; Sortino, Maria Angela

2017-01-01

Metabotropic glutamate (mGlu) receptor 5 is involved in neuroinflammation and has been shown to mediate reduced inflammation and neurotoxicity and to modify microglia polarization. On the other hand, blockade of mGlu5 receptor results in inhibition of microglia activation. To dissect this controversy, we investigated whether microvesicles (MVs) released from microglia BV2 cells could contribute to the communication between microglia and neurons and whether this interaction was modulated by mGlu5 receptor. Activation of purinergic ionotropic P2X7 receptor with the stable ATP analog benzoyl-ATP (100 μM) caused rapid MVs shedding from BV2 cells. Ionic currents through P2X7 receptor increased in BV2 cells pretreated for 24 h with the mGlu5 receptor agonist CHPG (200 μM) as by patch-clamp recording. This increase was blunted when microglia cells were activated by exposure to lipopolysaccharide (LPS; 0.1 μg/ml for 6 h). Accordingly, a greater amount of MVs formed after CHPG treatment, an effect prevented by the mGlu5 receptor antagonist MTEP (100 μM), as measured by expression of flotillin, a membrane protein enriched in MVs. Transferred MVs were internalized by SH-SY5Y neurons where they did not modify neuronal death induced by a low concentration of rotenone (0.1 μM for 24 h), but significantly increased rotenone neurotoxicity when shed from CHPG-treated BV2 cells. miR146a was increased in CHPG-treated MVs, an effect concealed in MVs from LPS-activated BV2 cells that showed per se an increase in miRNA146a levels. The present data support a role for microglia-shed MVs in mGlu5-mediated modulation of neuronal death and identify miRNAs as potential critical mediators of this interaction. PMID:29170640

Low-frequency drug-resistant HIV-1 and risk of virological failure to first-line NNRTI-based ART: a multicohort European case-control study using centralized ultrasensitive 454 pyrosequencing.

PubMed

Cozzi-Lepri, Alessandro; Noguera-Julian, Marc; Di Giallonardo, Francesca; Schuurman, Rob; Däumer, Martin; Aitken, Sue; Ceccherini-Silberstein, Francesca; D'Arminio Monforte, Antonella; Geretti, Anna Maria; Booth, Clare L; Kaiser, Rolf; Michalik, Claudia; Jansen, Klaus; Masquelier, Bernard; Bellecave, Pantxika; Kouyos, Roger D; Castro, Erika; Furrer, Hansjakob; Schultze, Anna; Günthard, Huldrych F; Brun-Vezinet, Francoise; Paredes, Roger; Metzner, Karin J

2015-03-01

It is still debated if pre-existing minority drug-resistant HIV-1 variants (MVs) affect the virological outcomes of first-line NNRTI-containing ART. This Europe-wide case-control study included ART-naive subjects infected with drug-susceptible HIV-1 as revealed by population sequencing, who achieved virological suppression on first-line ART including one NNRTI. Cases experienced virological failure and controls were subjects from the same cohort whose viraemia remained suppressed at a matched time since initiation of ART. Blinded, centralized 454 pyrosequencing with parallel bioinformatic analysis in two laboratories was used to identify MVs in the 1%-25% frequency range. ORs of virological failure according to MV detection were estimated by logistic regression. Two hundred and sixty samples (76 cases and 184 controls), mostly subtype B (73.5%), were used for the analysis. Identical MVs were detected in the two laboratories. 31.6% of cases and 16.8% of controls harboured pre-existing MVs. Detection of at least one MV versus no MVs was associated with an increased risk of virological failure (OR = 2.75, 95% CI = 1.35-5.60, P = 0.005); similar associations were observed for at least one MV versus no NRTI MVs (OR = 2.27, 95% CI = 0.76-6.77, P = 0.140) and at least one MV versus no NNRTI MVs (OR = 2.41, 95% CI = 1.12-5.18, P = 0.024). A dose-effect relationship between virological failure and mutational load was found. Pre-existing MVs more than double the risk of virological failure to first-line NNRTI-based ART. © The Author 2014. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy.

Macrofaunal assemblages from mud volcanoes in the Gulf of Cadiz: abundance, biodiversity and diversity partitioning across spatial scales

NASA Astrophysics Data System (ADS)

Cunha, M. R.; Rodrigues, C. F.; Génio, L.; Hilário, A.; Ravara, A.; Pfannkuche, O.

2013-04-01

The Gulf of Cadiz is an extensive seepage area in the south Iberian margin (NE Atlantic) encompassing over 40 mud volcanoes (MVs) at depths ranging from 200 to 4000 m. The area has a long geologic history and a central biogeographic location with a complex circulation ensuring oceanographic connectivity with the Mediterranean Sea, equatorial and North Atlantic regions. The geodynamics of the region promotes a notorious diversity in the seep regime despite the relatively low fluxes of hydrocarbon-rich gases. We analyse quantitative samples taken during the cruises TTR14, TTR15 and MSM01-03 in seven mud volcanoes grouped into Shallow MVs (Mercator: 350 m, Kidd: 500 m, Meknès: 700 m) and Deep MVs (Captain Arutyunov: 1300 m, Carlos Ribeiro: 2200 m, Bonjardim: 3000 m, Porto: 3900 m) and two additional Reference sites (ca. 550 m). Macrofauna (retained by a 500 μm sieve) was identified to species level whenever possible. The samples yielded modest abundances (70-1567 individuals per 0.25 m2), but the local and regional number of species is among the highest ever reported for cold seeps. Among the 366 recorded species, 22 were symbiont-hosting bivalves (Thyasiridae, Vesicomyidae, Solemyidae) and tubeworms (Siboglinidae). The multivariate analyses supported the significant differences between Shallow and Deep MVs: The environmental conditions at the Shallow MVs make them highly permeable to the penetration of background fauna leading to high diversity of the attendant assemblages (H': 2.92-3.94; ES(100): 28.3-45.0; J': 0.685-0.881). The Deep MV assemblages showed, in general, contrasting features but were more heterogeneous (H': 1.41-3.06; ES(100): 10.5-30.5; J': 0.340-0.852) and often dominated by one or more siboglinid species. The rarefaction curves confirmed the differences in biodiversity of Deep and Shallow MVs as well as the convergence of the latter to the Reference sites. The Bray-Curtis dissimilarity demonstrated the high β-diversity of the assemblages, especially in pairwise comparisons involving samples from the Deep MVs. Diversity partitioning assessed for species richness, Hurlbert's expected number of species and Shannon-Wiener index confirmed the high β-diversity across different spatial scales (within MVs, between MVs, between Deep and Shallow MVs). We suggest that historical and contemporary factors with differential synergies at different depths contribute to the high α-, β- and γ-diversity of the mud volcano faunal assemblages in the Gulf of Cadiz.

Organic geochemical signatures controlling methane outgassing at active mud volcanoes in the Canadian Beaufort Sea

NASA Astrophysics Data System (ADS)

DongHun, Lee; YoungKeun, Jin; JungHyun, Kim; Heldge, Niemann; JongKu, Gal; BoHyung, Choi

2016-04-01

Based on the water column acoustic anomalies related to active methane (CH4) venting, numerous active Mud Volcanoes (MVs) were recently identified at ~282, ~420, and ~740 m water depths on the continental slope of the Canadian Beaufort Sea (Paull et al., 2015). While geophysical aspects such as the multibeam bathymetric mapping are thoroughly investigated, biogeochemical processes controlling outgassing CH4 at the active MVs are not well constrained. Here, we investigated three sediment cores from the active MVs and one sediment core from a non-methane influenced reference site recovered during the ARA-05C expedition with the R/V ARAON in 2014. We analyzed lipid biomarkers and their stable carbon isotopic values (δ13C) in order to determine key biogeochemical processes involved in CH4 cycling in the MV sediments. Downcore CH4 and sulphate (SO42-) concentration measurements revealed a distinct sulfate-methane transition zone (SMTZ) at the shallow sections of the cores (15 - 45 cm below seafloor (cm bsf) at 282 m MV, 420 m MV, and 740 m MV). The most abundant diagnostic lipid biomarkers in the SMTZ were sn-2-hydroxyarchaeol (-94‰) and archaeol (-66‰) with the sn-2-hydroxyarchaeol: archaeol ratio of 1.1 to 5, indicating the presence of ANME-2 or -3. However, we also found substantial amounts of monocyclic biphytane-1 (BP-1, -118‰), which is rather indicative for ANME-1. Nevertheless, the concentration of sn-2-hydroxyarchaeol was 2-fold higher than any other archaeal lipids, suggesting a predominant ANME-2 or -3 rather than ANME-1 as a driving force for the anaerobic methane oxidation (AOM) in these systems. We will further investigate the microbial community at the active MVs using nucleic acid (RNA and DNA) sequence analyses in near future. Our study provides first biogeochemical data set of the active MVs in the Canadian Beaufort Sea, which helps to better understand CH4 cycling mediated in these systems. Reference Paull, C.K., et al. (2015), Active mud volcanoes on the continental slope of the Canadian Beaufort Sea. Geochemistry, Geophysics, Geosystems 16, doi:10.1002/2015GC005928.

Adipose-derived stem cell-derived microvesicle-released miR-210 promoted proliferation, migration and invasion of endothelial cells by regulating RUNX3.

PubMed

Zheng, Zeqi; Liu, Lijuan; Zhan, Yuliang; Yu, Songping; Kang, Ting

2018-06-18

To explore the potential mechanism of miRNA released from adipose-derived stem cell (ADSC)-derived micro vesicle (MV) on the modulation of proliferation, migration and invasion of endothelial cells. miR-210 level was detected by qT-PCR. Alix, VEGF and RUNX3 expressions were detected by Western blot. The proliferation, migration and invasion of human umbilical vein endothelial cells (HUVECs) were observed by MTT assay and Transwell assay. Luciferase reporter gene assay was conducted to validate the targeting activity of MVs-released miR-210 on RUNX3. Hypoxia significantly increased the expression of MVs-released miR-210. MVs released from ADSCs in hypoxic group significantly promoted the proliferation, migration and invasion of HUVECs. Overexpression of miR-210 significantly upregulated VEGF expression, and promoted the proliferation, migration and invasion of HUVECs. Besides, RUNX3 was identified as the direct of miR-210 in HUVECs. Overexpression of miR-210 decreased RUNX3 expression and promoted the proliferation, migration and invasion of HUVECs, while overexpression of RUNX3 inhibited these promotion effects. In vivo experiment showed that MVs derived from ADSCs under hypoxia increased miR-210 level and capillary density, and inhibition of miR-210 decreased capillary density. We also found MVs downregulated RUNX3 expression, and inhibition of miR-210 upregulated RUNX3 expression. miR-210 released from ADSCs-derived MVs promoted proliferation, migration and invasion of HUVECs by targeting RUNX3, which revealed one of the mechanisms of ADSCs-derived MVs on the promotion of proliferation, migration and invasion of HUVECs.

Tumor-Derived Microvesicles Modulate Antigen Cross-Processing via Reactive Oxygen Species-Mediated Alkalinization of Phagosomal Compartment in Dendritic Cells.

PubMed

Battisti, Federico; Napoletano, Chiara; Rahimi Koshkaki, Hassan; Belleudi, Francesca; Zizzari, Ilaria Grazia; Ruscito, Ilary; Palchetti, Sara; Bellati, Filippo; Benedetti Panici, Pierluigi; Torrisi, Maria Rosaria; Caracciolo, Giulio; Altieri, Fabio; Nuti, Marianna; Rughetti, Aurelia

2017-01-01

Dendritic cells (DCs) are the only antigen-presenting cells able to prime naïve T cells and cross-prime antigen-specific CD8 + T cells. Their functionality is a requirement for the induction and maintenance of long-lasting cancer immunity. Albeit intensively investigated, the in vivo mechanisms underlying efficient antigen cross-processing and presentation are not fully understood. Several pieces of evidence indicate that antigen transfer to DCs mediated by microvesicles (MVs) enhances antigen immunogenicity. This mechanism is also relevant for cross-presentation of those tumor-associated glycoproteins such as MUC1 that are blocked in HLA class II compartment when internalized by DCs as soluble molecules. Here, we present pieces of evidence that the internalization of tumor-derived MVs modulates antigen-processing machinery of DCs. Employing MVs derived from ovarian cancer ascites fluid and established tumor cell lines, we show that MV uptake modifies DC phagosomal microenvironment, triggering reactive oxygen species (ROS) accumulation and early alkalinization. Indeed, tumor MVs carry radical species and the MV uptake by DCs counteracts the chemically mediated acidification of the phagosomal compartment. Further pieces of evidence suggest that efficacious antigen cross-priming of the MUC1 antigen carried by the tumor MVs results from the early signaling induced by MV internalization and the function of the antigen-processing machinery of DCs. These results strongly support the hypothesis that tumor-derived MVs impact antigen immunogenicity by tuning the antigen-processing machinery of DCs, besides being carrier of tumor antigens. Furthermore, these findings have important implications for the exploitation of MVs as antigenic cell-free immunogen for DC-based therapeutic strategies.

Effect of Stimulative and Sedative Music Videos on Depressive Symptoms and Physiological Relaxation in Older Adults: A Pilot Study.

PubMed

Huang, Chiung-Yu; Hsieh, Yuan-Mei; Lai, Hui-Ling

2016-09-01

Music has been found to improve depressive symptoms and relaxation. However, few studies related to this issue have been conducted using music videos (MVs). The aim was to compare the effects of stimulative and sedative MVs on depressive symptoms and physiological relaxation (i.e., electromyography, heart rate variability, and skin conductance) in older adults with depressive symptoms. Using a 2-week crossover design, interventions alternated between watching a stimulative and sedative MV and vice versa. Each intervention lasted for 30 minutes on 1 day during the first week, and was then alternated to another intervention for 1 day during the following week. Stimulative MVs were more effective in treating depressive symptoms than sedative MVs. Stimulative and sedative MVs had beneficial effects on depressive symptoms and physiological relaxation compared with baseline data. These findings add new knowledge to the literature for health care providers to improve psychophysiological health in older adults with depressive symptoms. [Res Gerontol Nurs. 2016; 9(5):233-242.]. Copyright 2016, SLACK Incorporated.

Microvesicle removal of anticancer drugs contributes to drug resistance in human pancreatic cancer cells

PubMed Central

Muralidharan-Chari, Vandhana; Kohan, Hamed Gilzad; Asimakopoulos, Alexandros G.; Sudha, Thangirala; Sell, Stewart; Kannan, Kurunthachalam; Boroujerdi, Mehdi; Davis, Paul J.; Mousa, Shaker A.

2016-01-01

High mortality in pancreatic cancer patients is partly due to resistance to chemotherapy. We describe that human pancreatic cancer cells acquire drug resistance by a novel mechanism in which they expel and remove chemotherapeutic drugs from the microenvironment via microvesicles (MVs). Using human pancreatic cancer cells that exhibit varied sensitivity to gemcitabine (GEM), we show that GEM exposure triggers the cancer cells to release MVs in an amount that correlates with that cell line's sensitivity to GEM. The importance of MV-release in gaining drug resistance in GEM-resistant pancreatic cancer cells was confirmed when the inhibition of MV-release sensitized the cells to GEM treatment, both in vitro and in vivo. Mechanistically, MVs remove drugs that are internalized into the cells and that are in the microenvironment. The differences between the drug-resistant and drug-sensitive pancreatic cancer cell lines tested here are explained based on the variable content of influx/efflux proteins present on MVs, which directly dictates the ability of MVs either to trap GEM or to allow GEM to flow back to the microenvironment. PMID:27391262

Origin of lipid biomarkers in mud volcanoes from the Alboran Sea, western Mediterranean

NASA Astrophysics Data System (ADS)

López-Rodríguez, C.; Stadnitskaia, A.; De Lange, G. J.; Martínez-Ruíz, F.; Comas, M.

2014-06-01

Mud volcanoes (MVs) are the most prominent indicators of active methane/hydrocarbon venting at the seafloor on both passive and active continental margins. Their occurrence in the western Mediterranean is patent at the West Alboran Basin, where numerous MVs develop overlaying a major sedimentary depocentre containing overpressured shales. Although some of these MVs have been studied, the detailed biogeochemistry of expelled mud so far has not been examined in detail. This work provides the first results on the composition and origin of organic matter, anaerobic oxidation of methane (AOM) processes and general characteristics on MV dynamics using lipid biomarkers as the main tool. Lipid biomarker analysis was performed on MV expelled material (mud breccias) and interbedded hemipelagic sediments from Perejil, Kalinin and Schneider's Heart MVs located in the northwest margin of the Alboran Sea. The n alkane distributions and n alkane-derived indices (CPI and ACL), in combination with the epimerization degree of hopanes (22S/(22S+22R)) indicate that all studied mud breccia have a similar biomarker composition consisting of mainly thermally immature organic matter with an admixture of petroleum-derived compounds. This concordant composition indicates that common source strata must feed all three studied MVs. The past or present AOM activity was established using lipid biomarkers specific for anaerobic methanotrophic archaea (irregular isoprenoids and dialkyl glycerol diethers) and the depleted carbon isotope composition (δ13C) of crocetane/phytane. The presence of these lipid biomarkers, together with the low amounts of detected glycerol dialkyl glycerol tetraethers, is consistent with the dominance of anaerobic methanotrophs of the ANME-2 over ANME-1, at least in mud breccia from Perejil MVs. In contrast, the scarce presence or lack of these AOM-related lipid biomarkers in sediments from Kalinin and Schneider's Heart MVs, suggests that no recent active methane seepage has occurred at these sites. Moreover, the observed methane concentrations support the current activity of Perejil MV, and the very low methane seepage activity in Kalinin and Schneider's Heart MVs.

Study of geomorphological changes by high quality DEMs, obtained from UAVs-Structure from Motion in highest continental cliffs of Europe: A Capelada (Galicia, Spain)

NASA Astrophysics Data System (ADS)

Muñoz Narciso, Efrén; García, Horacio; Sierra Pernas, Chema; Pérez-Alberti, Augusto

2017-04-01

This study analyses the geomorphological evolution of a highly dynamic coastal environment, one of the higher cliffs in Continental Europe (A Capelada, NW Spain), using Structure from Motion-Multi View Stereoscan techniques (hereafter referred to as SfM-MVS). Comparing orthoimages from the last 10 years we observed several topographical changes in one specific valley (Teixidelo). Interestingly, these changes were caused by 2 different processes: (i) heavy coastal erosion and (ii) slow complex landslides, working in opposite directions. The main challenge was obtaining high quality topographical data for quantifying the changes during the last few years using low cost-high quality techniques in remote areas. Unmanned Aerial Vehicle platforms (drones, hereafter referred to as UAVs) and SFM-MVS offer ultrahigh-density topographical data. Furthermore, the use of drones and SfM-MVS close range images requires new applications in geomorphology for understanding the workflow and limitations. In this paper we present the 2 main results: (i) a centimeter spatial resolution DEM from august 2016 was obtained using a @DJI Phantom 3 advanced model drone. The pictures were processed in Agisoft PhotoScan Pro 1.2.6 version by SfM-MVS techniques, generating a high-density point cloud (i.e. ˜2000 points/m2) with 3mm of RMSE (i.e. the point cloud was georeferenced in a geographical coordinates system using ˜40 Ground Control Points obtained from differential RTK-GPS and a Total Station network) and (ii) a DEM of Differences, which compares official freely available 2010 LiDAR data (i.e. ˜2 points/m2) with a 2016 DEM derived by UAVs-SfM, where we have observed meter-scale elevation changes (i.e. sediment and erosion processes). During this time, 75% of the sediment has been mobilized. The novel UAVs and SfM-MVS techniques prove to be great for advancing the study of geomorphological processes in remote areas.

Identification and characterization of proteins isolated from microvesicles derived from human lung cancer pleural effusions.

PubMed

Park, Jung Ok; Choi, Do-Young; Choi, Dong-Sic; Kim, Hee Joung; Kang, Jeong Won; Jung, Jae Hun; Lee, Jeong Hwa; Kim, Jayoung; Freeman, Michael R; Lee, Kye Young; Gho, Yong Song; Kim, Kwang Pyo

2013-07-01

Microvesicles (MVs, also known as exosomes, ectosomes, microparticles) are released by various cancer cells, including lung, colorectal, and prostate carcinoma cells. MVs released from tumor cells and other sources accumulate in the circulation and in pleural effusion. Although recent studies have shown that MVs play multiple roles in tumor progression, the potential pathological roles of MV in pleural effusion, and their protein composition, are still unknown. In this study, we report the first global proteomic analysis of highly purified MVs derived from human nonsmall cell lung cancer (NSCLC) pleural effusion. Using nano-LC-MS/MS following 1D SDS-PAGE separation, we identified a total of 912 MV proteins with high confidence. Three independent experiments on three patients showed that MV proteins from PE were distinct from MV obtained from other malignancies. Bioinformatics analyses of the MS data identified pathologically relevant proteins and potential diagnostic makers for NSCLC, including lung-enriched surface antigens and proteins related to epidermal growth factor receptor signaling. These findings provide new insight into the diverse functions of MVs in cancer progression and will aid in the development of novel diagnostic tools for NSCLC. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Microvesicles released from human renal cancer stem cells stimulate angiogenesis and formation of lung premetastatic niche.

PubMed

Grange, Cristina; Tapparo, Marta; Collino, Federica; Vitillo, Loriana; Damasco, Christian; Deregibus, Maria Chiara; Tetta, Ciro; Bussolati, Benedetta; Camussi, Giovanni

2011-08-01

Recent studies suggest that tumor-derived microvesicles (MV) act as a vehicle for exchange of genetic information between tumor and stromal cells, engendering a favorable microenvironment for cancer development. Within the tumor mass, all cell types may contribute to MV shedding, but specific contributions to tumor progression have yet to be established. Here we report that a subset of tumor-initiating cells expressing the mesenchymal stem cell marker CD105 in human renal cell carcinoma releases MVs that trigger angiogenesis and promote the formation of a premetastatic niche. MVs derived only from CD105-positive cancer stem cells conferred an activated angiogenic phenotype to normal human endothelial cells, stimulating their growth and vessel formation after in vivo implantation in immunocompromised severe combined immunodeficient (SCID) mice. Furthermore, treating SCID mice with MVs shed from CD105-positive cells greatly enhanced lung metastases induced by i.v. injection of renal carcinoma cells. Molecular characterization of CD105-positive MVs defines a set of proangiogenic mRNAs and microRNAs implicated in tumor progression and metastases. Our results define a specific source of cancer stem cell-derived MVs that contribute to triggering the angiogenic switch and coordinating metastatic diffusion during tumor progression.

Ultrahigh-resolution mapping of peatland microform using ground-based structure from motion with multiview stereo

NASA Astrophysics Data System (ADS)

Mercer, Jason J.; Westbrook, Cherie J.

2016-11-01

Microform is important in understanding wetland functions and processes. But collecting imagery of and mapping the physical structure of peatlands is often expensive and requires specialized equipment. We assessed the utility of coupling computer vision-based structure from motion with multiview stereo photogrammetry (SfM-MVS) and ground-based photos to map peatland topography. The SfM-MVS technique was tested on an alpine peatland in Banff National Park, Canada, and guidance was provided on minimizing errors. We found that coupling SfM-MVS with ground-based photos taken with a point and shoot camera is a viable and competitive technique for generating ultrahigh-resolution elevations (i.e., <0.01 m, mean absolute error of 0.083 m). In evaluating 100+ viable SfM-MVS data collection and processing scenarios, vegetation was found to considerably influence accuracy. Vegetation class, when accounted for, reduced absolute error by as much as 50%. The logistic flexibility of ground-based SfM-MVS paired with its high resolution, low error, and low cost makes it a research area worth developing as well as a useful addition to the wetland scientists' toolkit.

Preoperative planning of left-sided valve surgery with 3D computed tomography reconstruction models: sternotomy or a minimally invasive approach?

PubMed

Heuts, Samuel; Maessen, Jos G; Sardari Nia, Peyman

2016-05-01

With the emergence of a new concept aimed at individualization of patient care, the focus will shift from whether a minimally invasive procedure is better than conventional treatment, to the question of which patients will benefit most from which technique? The superiority of minimally invasive valve surgery (MIVS) has not yet been proved. We believe that through better patient selection advantages of this technique can become more pronounced. In our current study, we evaluate the feasibility of 3D computed tomography (CT) imaging reconstruction in the preoperative planning of patients referred for MIVS. We retrospectively analysed all consecutive patients who were referred for minimally invasive mitral valve surgery (MIMVS) and minimally invasive aortic valve replacement (MIAVR) to a single surgeon in a tertiary referral centre for MIVS between March 2014 and 2015. Prospective preoperative planning was done for all patients and was based on evaluations by a multidisciplinary heart-team, an echocardiography, conventional CT images and 3D CT reconstruction models. A total of 39 patients were included in our study; 16 for mitral valve surgery (MVS) and 23 patients for aortic valve replacement (AVR). Eleven patients (69%) within the MVS group underwent MIMVS. Five patients (31%) underwent conventional MVS. Findings leading to exclusion for MIMVS were a tortuous or slender femoro-iliac tract, calcification of the aortic bifurcation, aortic elongation and pericardial calcifications. Furthermore, 2 patients had a change of operative strategy based on preoperative planning. Seventeen (74%) patients in the AVR group underwent MIAVR. Six patients (26%) underwent conventional AVR. Indications for conventional AVR instead of MIAVR were an elongated ascending aorta, ascending aortic calcification and ascending aortic dilatation. One patient (6%) in the MIAVR group was converted to a sternotomy due to excessive intraoperative bleeding. Two mortalities were reported during conventional MVS. There were no mortalities reported in the MIMVS, MIAVR or conventional AVR group. Preoperative planning of minimally invasive left-sided valve surgery with 3D CT reconstruction models is a useful and feasible method to determine operative strategy and exclude patients ineligible for a minimally invasive approach, thus potentially preventing complications. © The Author 2016. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

NDRG2 promoted secreted miR-375 in microvesicles shed from M1 microglia, which induced neuron damage.

PubMed

Tang, Li-li; Wu, Yuan-bo; Fang, Chuan-qin; Qu, Ping; Gao, Zong-liang

2016-01-15

Microglia microvesicles (MVs) has shown to have significant biological functions under normal conditions. A diversity of miRNAs is involved in neuronal development, survival, function, and plasticity, but the exact functional role of NDRG2 and secreted miR-375 in MVs in neuron damage is poorly understood. We investigated the effect of NDRG2 and secreted miR-375 in MVs shed from M1 microglia on neuron damage. Expression of Nos2, Arg-1, miR-375, syntaxin-1A, NDRG2 and Pdk 1 were evaluated using RT-PCR or western blotting. Cell viability of N2A neuron was quantified by a MTT assay. Microglia can be polarized into different functional phenotypes. Expression of NDRG2 and Nos2 were significantly increased by LPS treatment on N9 cells, whereas treatment with IL-4 dramatically suppressed the expression of NDRG2 and remarkably elevated expression of Arg-1. Besides, MVs shed from LPS-treated N9 microglia significantly inhibited cell viability of N2A neurons and expression of syntaxin-1A, and NDRG2 interference reversed the up-regulated miR-375 in LPS-treated N9 microglia and MVs shed from LPS-treated N9 cells. Furthermore, NDRG2 could modulate miR-375 expression in N9 microglia and MVs. And miR-375 inhibitor remarkably elevated Pdk1 expression in N2A neurons. Finally, miR-375 inhibitor could reverse suppression effect of NDRG2 overexpression on cell viability of N2A neurons and expression of syntaxin-1A. Our results demonstrated that NDRG2 promoted secreted miR-375 in microvesicles shed from M1 microglia, which induced neuron damage. The suppression of NDRG2 and secreted miR-375 in MVs shed from M1 microglia may be potential targets for alleviation of neuron damage. Copyright © 2015 Elsevier Inc. All rights reserved.

Explosive cell lysis as a mechanism for the biogenesis of bacterial membrane vesicles and biofilms

PubMed Central

Turnbull, Lynne; Toyofuku, Masanori; Hynen, Amelia L.; Kurosawa, Masaharu; Pessi, Gabriella; Petty, Nicola K.; Osvath, Sarah R.; Cárcamo-Oyarce, Gerardo; Gloag, Erin S.; Shimoni, Raz; Omasits, Ulrich; Ito, Satoshi; Yap, Xinhui; Monahan, Leigh G.; Cavaliere, Rosalia; Ahrens, Christian H.; Charles, Ian G.; Nomura, Nobuhiko; Eberl, Leo; Whitchurch, Cynthia B.

2016-01-01

Many bacteria produce extracellular and surface-associated components such as membrane vesicles (MVs), extracellular DNA and moonlighting cytosolic proteins for which the biogenesis and export pathways are not fully understood. Here we show that the explosive cell lysis of a sub-population of cells accounts for the liberation of cytosolic content in Pseudomonas aeruginosa biofilms. Super-resolution microscopy reveals that explosive cell lysis also produces shattered membrane fragments that rapidly form MVs. A prophage endolysin encoded within the R- and F-pyocin gene cluster is essential for explosive cell lysis. Endolysin-deficient mutants are defective in MV production and biofilm development, consistent with a crucial role in the biogenesis of MVs and liberation of extracellular DNA and other biofilm matrix components. Our findings reveal that explosive cell lysis, mediated through the activity of a cryptic prophage endolysin, acts as a mechanism for the production of bacterial MVs. PMID:27075392

Environmental Windows Associated with Dredging Operations

DTIC Science & Technology

1998-12-01

Unspecified species Mercenaria mercenaria MVR, LRL, MVS NAN Hard Clam Soft Shell Clam Mya arenaria NAE, NAB Surf Clam Spisula solidissima NAN Eastern...nearly 100 percent. This was followed closely by the North Atlantic and South Atlantic Divisions, with approximately 85 percent of all dredging projects... Atlantic Division (NAD) South Atlantic Division (SAD) Baltimore District (NAB) Charleston District (SAC) New England District (NAE) Jacksonville District

Evidence of episodic long-lived eruptions in the Yuma, Ginsburg, Jesús Baraza and Tasyo mud volcanoes, Gulf of Cádiz

NASA Astrophysics Data System (ADS)

Toyos, María H.; Medialdea, Teresa; León, Ricardo; Somoza, Luis; González, Francisco Javier; Meléndez, Nieves

2016-06-01

High-resolution single channel and multichannel seismic reflection profiles and multibeam bathymetric and backscatter data collected during several cruises over the period 1999 to 2007 have enabled characterising not only the seabed morphology but also the subsurface structural elements of the Yuma, Ginsburg, Jesús Baraza and Tasyo mud volcanoes (MVs) in the Gulf of Cádiz at 1,050-1,250 m water depth. These MVs vary strongly in morphology and size. The data reveal elongated cone-shaped edifices, rimmed depressions, and scarps interpreted as flank failures developed by collapse, faulting, compaction and gravitational processes. MV architecture is characterised by both extrusive and intrusive complexes, comprising stacked edifices (including seabed cones and up to four buried bicones) underlain by chaotic vertical zones and downward-tapering cones suggesting feeder systems. These intrusive structures represent the upper layer of the feeder system linking the fluid mud sources with the constructional edifices. The overall architecture is interpreted to be the result of successive events of mud extrusion and outbuilding alternating with periods of dormancy. Each mud extrusion phase is connected with the development of an edifice, represented by a seabed cone or a buried bicone. In all four MVs, the stacked edifices and the intrusive complexes penetrate Late Miocene-Quaternary units and are rooted in the Gulf of Cádiz wedge emplaced during the late Tortonian. Major phases of mud extrusion and outbuilding took place since the Late Pliocene, even though in the Yuma and Jesús Baraza MVs mud volcanism started in the Late Miocene shortly after the emplacement of the Gulf of Cádiz wedge. This study shows that fluid venting in the eastern sector of the Gulf of Cádiz promoted the outbuilding of large long-lived mud volcanoes active since the Late Miocene, and which have been reactivated repeatedly until recent times.

Presence of matrix vesicles in the body of odontoblasts and in the inner third of dentinal tissue: a scanning electron microscopic study.

PubMed

Garcés-Ortíz, Maricela; Ledesma-Montes, Constantino; Reyes-Gasga, José

2013-05-01

The aim of this report is to present the results of a scanning electron microscopic study on the presence of matrix vesicles (MVs) found in human dentine. Dentin tissue from 20 human bicuspids was analyzed by means of scanning electron microscopy. MVs were found as outgrowths of the cellular membrane of the odontoblastic body, the more proximal portion of the odontoblastic process before entering the dentinal tubule and in the odontoblastic process within the inner third of the dentin. Size of MVs varied depending on location. In the inner third of dentin, they were seen in diverse positions; as membranal outgrowths, deriving from the odontoblastic process, lying free in the intratubular space and attached to the dentinal wall. Sometimes, they were seen organized forming groups of different sizes and shapes or as multivesicular chains running from the surface of the odontoblastic process to the tubular wall. MVs were present in places never considered: 1) the body of odontoblasts; 2) the most proximal part of the odontoblastic processes before entering the circumpulpal dentine and also: 3) in the inner third of dentinal tissue. According to our results, MVs not only participate during mantle dentin mineralization during early dentinogenesis, they also contribute during the mineralization process of the inner dentin.

Multilayer Membranes of Glycosaminoglycans and Collagen I Biomaterials Modulate the Function and Microvesicle Release of Endothelial Progenitor Cells.

PubMed

Dai, Bingyan; Pan, Qunwen; Li, Zhanghua; Zhao, Mingyan; Liao, Xiaorong; Wu, Keng; Ma, Xiaotang

2016-01-01

Multilayer composite membrane of biomaterials can increase the function of adipose stem cells or osteoprogenitor cells. Recent evidence indicates endothelial progenitor cells (EPCs) and EPCs released microvesicles (MVs) play important roles in angiogenesis and vascular repair. Here, we investigated the effects of biomaterial multilayer membranes of hyaluronic acid (HA) or chondroitin sulfate (CS) and Collagen I (Col I) on the functions and MVs release of EPCs. Layer-by-layer (LBL) technology was applied to construct the multilayer composite membranes. Four types of the membranes constructed by adsorbing either HA or CS and Col I alternatively with different top layers were studied. The results showed that all four types of multilayer composite membranes could promote EPCs proliferation and migration and inhibit cell senility, apoptosis, and the expression of activated caspase-3. Interestingly, these biomaterials increased the release and the miR-126 level of EPCs-MVs. Moreover, the CS-Col I membrane with CS on the top layer showed the most effects on promoting EPCs proliferation, EPCs-MV release, and miR-126 level in EPCs-MVs. In conclusion, HA/CS and Collagen I composed multilayer composite membranes can promote EPCs functions and release of miR-126 riched EPCs-MVs, which provides a novel strategy for tissue repair treatment.

Three species of Reteporella (Bryozoa: Cheilostomata) in a diapiric and mud volcano field of the Gulf of Cádiz, with the description of Reteporella victori n. sp.

PubMed

Ramalho, LaÍs V; LÓpez-fÉ, Carlos M; Rueda, JosÉ Luis

2018-01-23

Diapirs and mud volcanoes (MVs) are formed by the migration and extrusion of fluids and mud to the seafloor, respectively. In the Gulf of Cádiz there are ca. 60 MVs and several diapirs with different environmental conditions and seepage activity. Previous studies, mainly on MVs, have demonstrated that the invertebrate fauna associated with these seafloor structures can be very diverse, including chemosymbiotic species, mostly mollusks and frenulate polychaetes, as well as vulnerable suspension feeders, such as cold-water corals and sponges, among others. Previous studies of the bryozoan fauna in this area have recorded species belonging to 28 families. One of these families is Phidoloporidae, which comprises 27 genera worldwide, including the common Rhynchozoon, Reteporellina, and Reteporella. In the present study, two species belonging to Reteporella are redescribed, and a new species is described from diapirs and MVs on the shelf and slope of the Gulf of Cádiz. The samples were collected during several oceanographic expeditions carried out by the Instituto Español de Oceanografia. This genus is well represented in the NE Atlantic Ocean and the Mediterranean Sea, and our study extends its occurrence on MVs and diapirs fields of the Gulf of Cádiz.

Ocular stability and set-point adaptation

PubMed Central

Jareonsettasin, P.; Leigh, R. J.

2017-01-01

A fundamental challenge to the brain is how to prevent intrusive movements when quiet is needed. Unwanted limb movements such as tremor impair fine motor control and unwanted eye drifts such as nystagmus impair vision. A stable platform is also necessary to launch accurate movements. Accordingly, nature has designed control systems with agonist (excitation) and antagonist (inhibition) muscle pairs functioning in push–pull, around a steady level of balanced tonic activity, the set-point. Sensory information can be organized similarly, as in the vestibulo-ocular reflex, which generates eye movements that compensate for head movements. The semicircular canals, working in coplanar pairs, one in each labyrinth, are reciprocally excited and inhibited as they transduce head rotations. The relative change in activity is relayed to the vestibular nuclei, which operate around a set-point of stable balanced activity. When a pathological imbalance occurs, producing unwanted nystagmus without head movement, an adaptive mechanism restores the proper set-point and eliminates the nystagmus. Here we used 90 min of continuous 7 T magnetic field labyrinthine stimulation (MVS) in normal humans to produce sustained nystagmus simulating vestibular imbalance. We identified multiple time-scale processes towards a new zero set-point showing that MVS is an excellent paradigm to investigate the neurobiology of set-point adaptation. This article is part of the themed issue ‘Movement suppression: brain mechanisms for stopping and stillness’. PMID:28242733

Mechanical Injury Induces Brain Endothelial-Derived Microvesicle Release: Implications for Cerebral Vascular Injury during Traumatic Brain Injury.

PubMed

Andrews, Allison M; Lutton, Evan M; Merkel, Steven F; Razmpour, Roshanak; Ramirez, Servio H

2016-01-01

It is well established that the endothelium responds to mechanical forces induced by changes in shear stress and strain. However, our understanding of vascular remodeling following traumatic brain injury (TBI) remains incomplete. Recently published studies have revealed that lung and umbilical endothelial cells produce extracellular microvesicles (eMVs), such as microparticles, in response to changes in mechanical forces (blood flow and mechanical injury). Yet, to date, no studies have shown whether brain endothelial cells produce eMVs following TBI. The brain endothelium is highly specialized and forms the blood-brain barrier (BBB), which regulates diffusion and transport of solutes into the brain. This specialization is largely due to the presence of tight junction proteins (TJPs) between neighboring endothelial cells. Following TBI, a breakdown in tight junction complexes at the BBB leads to increased permeability, which greatly contributes to the secondary phase of injury. We have therefore tested the hypothesis that brain endothelium responds to mechanical injury, by producing eMVs that contain brain endothelial proteins, specifically TJPs. In our study, primary human adult brain microvascular endothelial cells (BMVEC) were subjected to rapid mechanical injury to simulate the abrupt endothelial disruption that can occur in the primary injury phase of TBI. eMVs were isolated from the media following injury at 2, 6, 24, and 48 h. Western blot analysis of eMVs demonstrated a time-dependent increase in TJP occludin, PECAM-1 and ICAM-1 following mechanical injury. In addition, activation of ARF6, a small GTPase linked to extracellular vesicle production, was increased after injury. To confirm these results in vivo, mice were subjected to sham surgery or TBI and blood plasma was collected 24 h post-injury. Isolation and analysis of eMVs from blood plasma using cryo-EM and flow cytometry revealed elevated levels of vesicles containing occludin following brain trauma. These results indicate that following TBI, the cerebral endothelium undergoes vascular remodeling through shedding of eMVs containing TJPs and endothelial markers. The detection of this shedding potentially allows for a novel methodology for real-time monitoring of cerebral vascular health (remodeling), BBB status and neuroinflammation following a TBI event.

Effects and Dose-Response Relationships of Motor Imagery Practice on Strength Development in Healthy Adult Populations: a Systematic Review and Meta-analysis.

PubMed

Paravlic, Armin H; Slimani, Maamer; Tod, David; Marusic, Uros; Milanovic, Zoran; Pisot, Rado

2018-05-01

Motor imagery (MI), a mental simulation of a movement without overt muscle contraction, has been largely used to improve general motor tasks. However, the effects of MI practice on maximal voluntary strength (MVS) remain equivocal. The aims of this meta-analysis were to (1) estimate whether MI practice intervention can meaningfully improve MVS in healthy adults; (2) compare the effects of MI practice on MVS with its combination with physical practice (MI-C), and with physical practice (PP) training alone; and (3) investigate the dose-response relationships of MI practice. Seven electronic databases were searched up to April 2017. Initially 717 studies were identified; however, after evaluation of the study characteristics, data from 13 articles involving 370 participants were extracted. The meta-analysis was completed on MVS as the primary parameter. In addition, parameters associated with training volume, training intensity, and time spent training were used to investigate dose-response relationships. MI practice moderately improved MVS. When compared to conventional PP, effects were of small benefit in favour of PP. MI-C when compared to PP showed unclear effects. MI practice produced moderate effects in both upper and lower extremities on MVS. The cortical representation area of the involved muscles did not modify the effects. Meta-regression analysis revealed that (a) a training period of 4 weeks, (b) a frequency of three times per week, (c) two to three sets per single session, (d) 25 repetitions per single set, and (e) single session duration of 15 min were associated with enhanced improvements in muscle strength following MI practice. Similar dose-response relationships were observed following MI and PP. The present meta-analysis demonstrates that compared to a no-exercise control group of healthy adults, MI practice increases MVS, but less than PP. These findings suggest that MI practice could be considered as a substitute or additional training tool to preserve muscle function when athletes are not exposed to maximal training intensities.

A novel 3D imaging system for strawberry phenotyping.

PubMed

He, Joe Q; Harrison, Richard J; Li, Bo

2017-01-01

Accurate and quantitative phenotypic data in plant breeding programmes is vital in breeding to assess the performance of genotypes and to make selections. Traditional strawberry phenotyping relies on the human eye to assess most external fruit quality attributes, which is time-consuming and subjective. 3D imaging is a promising high-throughput technique that allows multiple external fruit quality attributes to be measured simultaneously. A low cost multi-view stereo (MVS) imaging system was developed, which captured data from 360° around a target strawberry fruit. A 3D point cloud of the sample was derived and analysed with custom-developed software to estimate berry height, length, width, volume, calyx size, colour and achene number. Analysis of these traits in 100 fruits showed good concordance with manual assessment methods. This study demonstrates the feasibility of an MVS based 3D imaging system for the rapid and quantitative phenotyping of seven agronomically important external strawberry traits. With further improvement, this method could be applied in strawberry breeding programmes as a cost effective phenotyping technique.

Vascular smooth muscle cell calcification is mediated by regulated exosome secretion.

PubMed

Kapustin, Alexander N; Chatrou, Martijn L L; Drozdov, Ignat; Zheng, Ying; Davidson, Sean M; Soong, Daniel; Furmanik, Malgorzata; Sanchis, Pilar; De Rosales, Rafael Torres Martin; Alvarez-Hernandez, Daniel; Shroff, Rukshana; Yin, Xiaoke; Muller, Karin; Skepper, Jeremy N; Mayr, Manuel; Reutelingsperger, Chris P; Chester, Adrian; Bertazzo, Sergio; Schurgers, Leon J; Shanahan, Catherine M

2015-04-10

Matrix vesicles (MVs), secreted by vascular smooth muscle cells (VSMCs), form the first nidus for mineralization and fetuin-A, a potent circulating inhibitor of calcification, is specifically loaded into MVs. However, the processes of fetuin-A intracellular trafficking and MV biogenesis are poorly understood. The objective of this study is to investigate the regulation, and role, of MV biogenesis in VSMC calcification. Alexa488-labeled fetuin-A was internalized by human VSMCs, trafficked via the endosomal system, and exocytosed from multivesicular bodies via exosome release. VSMC-derived exosomes were enriched with the tetraspanins CD9, CD63, and CD81, and their release was regulated by sphingomyelin phosphodiesterase 3. Comparative proteomics showed that VSMC-derived exosomes were compositionally similar to exosomes from other cell sources but also shared components with osteoblast-derived MVs including calcium-binding and extracellular matrix proteins. Elevated extracellular calcium was found to induce sphingomyelin phosphodiesterase 3 expression and the secretion of calcifying exosomes from VSMCs in vitro, and chemical inhibition of sphingomyelin phosphodiesterase 3 prevented VSMC calcification. In vivo, multivesicular bodies containing exosomes were observed in vessels from chronic kidney disease patients on dialysis, and CD63 was found to colocalize with calcification. Importantly, factors such as tumor necrosis factor-α and platelet derived growth factor-BB were also found to increase exosome production, leading to increased calcification of VSMCs in response to calcifying conditions. This study identifies MVs as exosomes and shows that factors that can increase exosome release can promote vascular calcification in response to environmental calcium stress. Modulation of the exosome release pathway may be as a novel therapeutic target for prevention. © 2015 American Heart Association, Inc.

Effects of N-acetyl-L-cysteine on the membrane vesicle release and growth of respiratory pathogens.

PubMed

Volgers, Charlotte; Benedikter, Birke J; Grauls, Gert E; Hellebrand, Pauline H M; Savelkoul, Paul H M; Stassen, Frank R M

2017-05-01

Bacterial infections contribute to the disease progression of chronic obstructive pulmonary disease by stimulating mucus production in the airways. This increased mucus production and other symptoms are often alleviated when patients are treated with mucolytics such as N-acetyl-L-cysteine (NAC). Moreover, NAC has been suggested to inhibit bacterial growth. Bacteria can release membrane vesicles (MVs) in response to stress, and recent studies report a role for these proinflammatory MVs in the pathogenesis of airways disease. Yet, until now it is not clear whether NAC also affects the release of these MVs. This study set out to determine whether NAC, at concentrations reached during high-dose nebulization, affects bacterial growth and MV release of the respiratory pathogens non-typeable Haemophilus influenzae (NTHi), Moraxella catarrhalis (Mrc), Streptococcus pneumoniae (Spn) and Pseudomonas aeruginosa (Psa). We observed that NAC exerted a strong bacteriostatic effect, but also induced the release of proinflammatory MVs by NTHi, Mrc and Psa, but not by Spn. Interestingly, NAC also markedly blunted the release of TNF-α by naive macrophages in response to MVs. This suggests that the application of NAC by nebulization at a high dosage may be beneficial for patients with airway conditions associated with bacterial infections. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

LiDAR and Image Point Cloud Comparison

DTIC Science & Technology

2014-09-01

UAV unmanned aerial vehicle USGS United States Geological Survey UTM Universal Transverse Mercator WGS 84 World Geodetic System 1984 WSI...19  1.  Physics of LiDAR Systems ................................................................20  III.  DATA AND SOFTWARE...ground control point GPS Global Positioning System IMU inertial measurements unit LiDAR light detection and ranging MI mutual information MVS

Correlates of viral suppression among HIV-infected men who have sex with men and transgender women in Lima, Peru.

PubMed

Rich, Katherine M; Valencia Huamaní, Javier; Kiani, Sara N; Cabello, Robinson; Elish, Paul; Florez Arce, Jorge; Pizzicato, Lia N; Soria, Jaime; Wickersham, Jeffrey A; Sanchez, Jorge; Altice, Frederick L

2018-05-30

In Peru, HIV is concentrated among men who have sex with men (MSM) and transgender women (TGW). Between June 2015 and August 2016, 591 HIV-positive MSM and TGW were recruited at five clinical care sites in Lima, Peru. We found that 82.4% of the participants had achieved viral suppression (VS; VL < 200) and 73.6% had achieved maximal viral suppression (MVS; VL < 50). Multivariable modeling indicated that patients reporting transportation as a barrier to HIV care were less likely to achieve VS (aOR = 0.47; 95% CI = 0.30-0.75) and MVS (aOR = 0.56; 95% CI = 0.37-0.84). Alcohol use disorders were negatively associated with MVS (aOR = 0.62; 95% CI = 0.30-0.75) and age was positively associated with achieving MVS (aOR = 1.29; 95% CI = 1.04-1.59). These findings underscore the need for more accessible HIV care with integrated behavioral health services in Lima, Peru.

Ewing Sarcoma Cells Secrete EWS/Fli-1 Fusion mRNA via Microvesicles

PubMed Central

Tsugita, Masanori; Yamada, Nami; Noguchi, Shunsuke; Yamada, Kazunari; Moritake, Hiroshi; Shimizu, Katsuji; Akao, Yukihiro; Ohno, Takatoshi

2013-01-01

Tumours defined as Ewing sarcoma (ES) constitute a group of highly malignant neoplasms that most often affect children and young adults in the first 2 decades of life. The EWS/Fli-1 fusion gene, a product of the translocation t(11;22) (q24; 12), is detected in 95% of ES patients. Recently, it was validated that cells emit a heterogeneous mixture of vesicular, organelle-like structures (microvesicles, MVs) into their surroundings including blood and body fluids, and that these MVs contain a selected set of tumor-related proteins and high levels of mRNAs and miRNAs. In this present study, we detected the Ewing sarcoma-specific EWS/Fli-1 mRNA in MVs from the culture medium of ES cell lines carrying t(11;22) (q24; 12). Also, we detected this fusion gene in approximately 40% of the blood samples from mice inoculated with xenografts of TC135 or A673 cells. These findings indicate the EWS/Fli-1 mRNA in MVs might be a new non-invasive diagnostic marker for specific cases of Ewing sarcoma. PMID:24124617

Moral Values Congruence and Miners' Policy Following Behavior: The Role of Supervisor Morality.

PubMed

Lu, Hui; Chen, Hong; Du, Wei; Long, Ruyin

2017-06-01

Ethical culture construction is beneficial to maximize policy following behavior (PFB) and avoid accidents of coal miners in an economic downturn. This paper examines the congruence between coal mine ethical culture values (ECVs) and miners' moral values (MVs) and the relationship with PFB. To shed light on this relationship, supervisor moral values (SMVs) act as a key moderator. We build on the initial structure of values to measure ECVs, MVs, and SMVs. At the same time, available congruence was defined to describe the relationship between the two values. Drawing upon a survey of 267 miners in Chinese large state-owned coal mining enterprises, results revealed that ECVs-MVs congruence had a linear relationship with intrinsic PFB (IPFB) and a non-linear relationship with extrinsic PFB. These findings demonstrate that SMVs had a moderating effect on the relationship between ECVs-MVs congruence and extrinsic PFB. Thus, we continued to calculate the available congruence scope in tested enterprises. Furthermore, this study gives relative management proposals and suggestions to improve miners' moral standards and to reduce coal mine accidents.

Suitability of ground-based SfM-MVS for monitoring glacial and periglacial processes

NASA Astrophysics Data System (ADS)

Piermattei, Livia; Carturan, Luca; de Blasi, Fabrizio; Tarolli, Paolo; Dalla Fontana, Giancarlo; Vettore, Antonio; Pfeifer, Norbert

2016-05-01

Photo-based surface reconstruction is rapidly emerging as an alternative survey technique to lidar (light detection and ranging) in many fields of geoscience fostered by the recent development of computer vision algorithms such as structure from motion (SfM) and dense image matching such as multi-view stereo (MVS). The objectives of this work are to test the suitability of the ground-based SfM-MVS approach for calculating the geodetic mass balance of a 2.1 km2 glacier and for detecting the surface displacement of a neighbouring active rock glacier located in the eastern Italian Alps. The photos were acquired in 2013 and 2014 using a digital consumer-grade camera during single-day field surveys. Airborne laser scanning (ALS, otherwise known as airborne lidar) data were used as benchmarks to estimate the accuracy of the photogrammetric digital elevation models (DEMs) and the reliability of the method. The SfM-MVS approach enabled the reconstruction of high-quality DEMs, which provided estimates of glacial and periglacial processes similar to those achievable using ALS. In stable bedrock areas outside the glacier, the mean and the standard deviation of the elevation difference between the SfM-MVS DEM and the ALS DEM was -0.42 ± 1.72 and 0.03 ± 0.74 m in 2013 and 2014, respectively. The overall pattern of elevation loss and gain on the glacier were similar with both methods, ranging between -5.53 and + 3.48 m. In the rock glacier area, the elevation difference between the SfM-MVS DEM and the ALS DEM was 0.02 ± 0.17 m. The SfM-MVS was able to reproduce the patterns and the magnitudes of displacement of the rock glacier observed by the ALS, ranging between 0.00 and 0.48 m per year. The use of natural targets as ground control points, the occurrence of shadowed and low-contrast areas, and in particular the suboptimal camera network geometry imposed by the morphology of the study area were the main factors affecting the accuracy of photogrammetric DEMs negatively. Technical improvements such as using an aerial platform and/or placing artificial targets could significantly improve the results but run the risk of being more demanding in terms of costs and logistics.

Nonencapsidated 5' Copy-Back Defective Interfering Genomes Produced by Recombinant Measles Viruses Are Recognized by RIG-I and LGP2 but Not MDA5.

PubMed

Mura, Marie; Combredet, Chantal; Najburg, Valérie; Sanchez David, Raul Y; Tangy, Frédéric; Komarova, Anastassia V

2017-10-15

Attenuated measles virus (MV) is one of the most effective and safe vaccines available, making it an attractive candidate vector for preventing other infectious diseases. Yet the great capacity of this vaccine still needs to be understood at the molecular level. MV vaccine strains have different type I interferon (IFN)-inducing abilities that partially depend on the presence of 5' copy-back defective interfering genomes (DI-RNAs). DI-RNAs are pathogen-associated molecular patterns recognized by RIG-I-like receptors (RLRs) (RIG-I, MDA5, and LGP2) that activate innate immune signaling and shape the adaptive immune response. In this study, we characterized the DI-RNAs produced by various modified recombinant MVs (rMVs), including vaccine candidates, as well as wild-type MV. All tested rMVs produced 5' copy-back DI-RNAs that were different in length and nucleotide sequence but still respected the so-called "rule of six." We correlated the presence of DI-RNAs with a larger stimulation of the IFN-β pathway and compared their immunostimulatory potentials. Importantly, we revealed that encapsidation of DI-RNA molecules within the MV nucleocapsid abolished their immunoactive properties. Furthermore, we identified specific interactions of DI-RNAs with both RIG-I and LGP2 but not MDA5. Our results suggest that DI-RNAs produced by rMV vaccine candidates may indeed strengthen their efficiency by triggering RLR signaling. IMPORTANCE Having been administered to hundreds of millions of children, the live attenuated measles virus (MV) vaccine is the safest and most widely used human vaccine, providing high protection with long-term memory. Additionally, recombinant MVs carrying heterologous antigens are promising vectors for new vaccines. The great capacity of this vaccine still needs to be elucidated at the molecular level. Here we document that recombinant MVs produce defective interfering genomes that have high immunostimulatory properties via their binding to RIG-I and LGP2 proteins, both of which are cytosolic nonself RNA sensors of innate immunity. Defective interfering genome production during viral replication should be considered of great importance due to the immunostimulatory properties of these genomes as intrinsic adjuvants produced by the vector that increase recognition by the innate immune system. Copyright © 2017 American Society for Microbiology.

Integration of UAV and ground-based Structure from Motion with Multi-View Stereo photogrammetry and hydrological data to quantify hillslope gully erosion processes in tropical savanna

NASA Astrophysics Data System (ADS)

Koci, J.; Jarihani, B.; Sidle, R. C.; Wilkinson, S. N.; Bartley, R.

2017-12-01

Structure from Motion with Multi-View Stereo (SfM-MVS) photogrammetry provides a cost-effective method of rapidly acquiring high resolution (sub-meter) topographic data, but is rarely used in hydrogeomorphic investigations of gully erosion. This study integrates high resolution topographic and land cover data derived from an unmanned aerial vehicle (UAV) and ground-based SfM-MVS photogrammetry, with rainfall and gully discharge data, to elucidate hydrogeomorphic processes driving hillslope gully erosion. The study is located within a small (13 km2) dry-tropical savanna catchment within the Burdekin River Basin, northeast Australia, which is a major contributor sediments and nutrients to the Great Barrier Reef World Heritage Area. A pre-wet season UAV survey covered an entire hillslope gully system (0.715 km2), and is used to derive topography, ground cover and hydrological flow pathways in the gully contributing area. Ground-based surveys of a single active gully (650 m2) within the broader hillslope are compared between pre- and post-wet season conditions to quantify gully geomorphic change. Rainfall, recorded near to the head of the gully, is related to gully discharge during sporadic storm events. The study provides valuable insights into the relationships among hydrological flow pathways, ground cover, rainfall and runoff, and spatial patterns of gully morphologic change. We demonstrate how UAV and ground-based SfM-MVS photogrammetry can be used to improve hydrogeomorphic process understanding and aid in the modelling and management of hillslope gully systems.

Isolation of vaccine-derived measles viruses from children with acute respiratory infection.

PubMed

Aoki, Yoko; Mizuta, Katsumi; Ikeda, Tatsuya; Abiko, Chieko; Itagaki, Tsutomu; Ahiko, Tadayuki

2013-06-01

The measles elimination project led by the World Health Organization (WHO) has been moving toward the target of eliminating measles in the WHO Western Pacific Region. In Japan, prefectural public health institutes play a key role for the laboratory diagnosis of measles virus (MV) infection, which is based on PCR, virus isolation, and genotyping. Microscopic examination of viral-sensitive cell lines during routine virus isolation from nasopharyngeal specimens has been used to detect the morphological changes typical for the growth of respiratory viruses. Here, we describe the unexpected isolation of vaccine-derived MVs from the two unrelated 1-year-old boys with acute respiratory infection. The nasopharyngeal specimens were obtained from one patient in February 2007 and from another in December 2012. Incidentally, the two children had received measles-rubella vaccination 9 or 11 days before the sampling. The isolates from two children induced morphological changes of the viral-sensitive cell lines, such as syncythia formation (cell fusion). We finally identified the isolates as vaccine-derived MVs by sequence analysis and immunological methods with anti-measles nucleoprotein antibodies. As no typical symptoms of MV infection were observed in either patient, the vaccine-derived MVs were isolated not as causative pathogens but by chance. In fact, there was no suspected case of secondary MV infection in either patient, thereby excluding the possibility that vaccine-derived MVs spread from human to human. Our experiences suggest the possibility of vaccine-derived MV isolation by cell cultures and the difficulty in identifying MVs in specimens from patients other than clinically suspected measles cases.

IBM NJE protocol emulator for VAX/VMS

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

Engert, D.E.

1981-01-01

Communications software has been written at Argonne National Laboratory to enable a VAX/VMS system to participate as an end-node in a standard IBM network by emulating the Network Job Entry (NJE) protocol. NJE is actually a collection of programs that support job networking for the operating systems used on most large IBM-compatible computers (e.g., VM/370, MVS with JES2 or JES3, SVS, MVT with ASP or HASP). Files received by the VAX can be printed or saved in user-selected disk files. Files sent to the network can be routed to any node in the network for printing, punching, or job submission,more » as well as to a VM/370 user's virtual reader. Files sent from the VAX are queued and transmitted asynchronously to allow users to perform other work while files are awaiting transmission. No changes are required to the IBM software.« less

Skeletal mineralization deficits and impaired biogenesis and function of chondrocyte-derived matrix vesicles in Phospho1−/− and Phospho1/Pit1 double knockout mice

PubMed Central

Yadav, Manisha C.; Bottini, Massimo; Cory, Esther; Bhattacharya, Kunal; Kuss, Pia; Narisawa, Sonoko; Sah, Robert L.; Beck, Laurent; Fadeel, Bengt; Farquharson, Colin; Millán, José Luis

2016-01-01

We have previously shown that ablation of either the Phospho1 or Alpl gene, encoding PHOSPHO1 and tissue-nonspecific alkaline phosphatase (TNAP) respectively, lead to hyperosteoidosis but that their chondrocyte- and osteoblast-derived matrix vesicles (MVs) are able to initiate mineralization. In contrast, the double ablation of Phospho1 and Alpl completely abolish initiation and progression of skeletal mineralization. We argued that MVs initiate mineralization by a dual mechanism: PHOSPHO1-mediated intravesicular generation of Pi and phosphate transporter-mediated influx of Pi. To test this hypothesis, we generated mice with col2a1-driven cre-mediated ablation of Slc20a1, hereafter referred to as Pit1, alone or in combination with a Phospho1 gene deletion. Pit1col2/col2 mice did not show any major phenotypic abnormalities, while severe skeletal deformities were observed in the [Phospho1−/−; Pit1col2/col2] double knockout mice that were more pronounced than those observed in the Phospho1−/− mice. Histological analysis of [Phospho1−/−; Pit1col2/col2] bones showed growth plate abnormalities with a shorter hypertrophic chondrocyte zone and extensive hyperosteoidosis. The [Phospho1−/−; Pit1col2/col2] skeleton displayed significantly decreases in BV/TV%, trabecular number and bone mineral density, as well as decreased stiffness, decreased strength, and increased post-yield deflection compared to Phospho1−/− mice. Using atomic force microscopy we found that ~80% of [Phospho1−/−; Pit1col2/col2] MVs were devoid of mineral in comparison to ~50 % for the Phospho1−/− MVs and ~25% for the WT and Pit1col2/col2 MVs. We also found a significant decrease in the number of MVs produced by both Phospho1−/− and [Phospho1−/−; Pit1col2/col2] chondrocytes. These data support the involvement of PiT-1 in the initiation of skeletal mineralization and provide compelling evidence that PHOSPHO1 function is involved in MV biogenesis. PMID:26773408

Acoustic and gravity features of mud volcanoes along the seaward part of the Kumano forearc basin, Nankai region, central Japan

NASA Astrophysics Data System (ADS)

Asada, M.

2017-12-01

Mud volcanoes (MV) are geological features that are observed all over the world, especially along plate convergent margins. MVs bring fluid and sediment to the surface from depth. MVs around Japan are expected to transport of information from the shallow portions of the seismogenic zone. The Kumano forearc basin (FAB) in the Nankai region is the most studied area in Japan. It is bounded by a shelf on the north, and the Kumano Basin edge fault zone (KBEFZ) on the south. The Kumano FAB has 1-2 km of sediment and overlies the accretionary prism. There are at least 14 MVs in the Kumano Basin. Most of them are found over the northern basin floor, and at least one MV is at the KBEFZ. The MV at the KBEFZ is imaged on a 3D seismic data set as a small topographic feature on seafloor with a disrupted BSR below it. On high-resolution acoustic imagery, it is an 80 100m-high hill with a crater-like depression. It is characterized by a negative ph anomaly detected just above it. High-backscatter seafloor recognized around the MV suggests that harder seafloor exists in that area. To determine whether large subseafloor diapirs exist below active MVs, we try to detect the gravity contrast between the allochthonous materials and basin sediment. Gravity data were collected by research vessels over the area in 2012 2017. After corrections of drift and Etovos effects, absolute gravity, free-air and Bouguer gravity anomalies were calculated. The gravity data do not always show anomalies directly on MVs over the northern basin, thus suggesting that larger diapirs which have gravity contrast over a few milli-Gals do not exist below most of MVs in this basin. Instead, a large negative gravity anomaly is found at the northeastern end of the Kumano Basin. Localized positive anomalies exist along the KBEFZ in the area of theMV. The positive anomaly may suggest that an allochthonous high-density sediment body intrudes along the highly deformed, weak, fault zone.

Evaluation of amniotic mesenchymal cell derivatives on cytokine production in equine alveolar macrophages: an in vitro approach to lung inflammation.

PubMed

Zucca, Enrica; Corsini, Emanuela; Galbiati, Valentina; Lange-Consiglio, Anna; Ferrucci, Francesco

2016-09-20

Data obtained in both animal models and clinical trials suggest that cell-based therapies represent a potential therapeutic strategy for lung repair and remodeling. Recently, new therapeutic approaches based on the use of stem cell derivatives (e.g., conditioned medium (CM) and microvesicles (MVs)) to regenerate tissues and improve their functions were proposed. The aim of this study was to investigate the immunomodulatory effects of equine amniotic mesenchymal cell derivatives on lipopolysaccharide (LPS)-induced cytokine production in equine alveolar macrophages, which may be beneficial in lung inflammatory disorders such as recurrent airway obstruction (RAO) in horses. RAO shares many features with human asthma, including an increased number of cells expressing mRNA for interleukin (IL)-4 and IL-5 and a decreased expression of IFN-γ in bronchoalveolar lavage fluid (BALF) of affected horses. The release of TNF-α, IL-6, and TGF-β1 at different time points (1, 24, 48, and 72 h) was measured in equine alveolar macrophages stimulated or not with LPS (10 and 100 ng/mL) in the presence or absence of 10 % CM or 50 × 10(6) MVs/mL. Cytokines were measured using commercially available ELISA kits. For multiple comparisons, analysis of variance was used with Tukey post-hoc test. Differences were considered significant at p ≤ 0.05. Significant modulatory effects of CM on LPS-induced TNF-α release at 24 h, and of both CM and MVs on TNF-α release at 48 h were observed. A trend toward a modulatory effect of both CM and MVs on the release of TGF-β and possibly IL-6 was visible over time. Results support the potential use of CM and MVs in lung regenerative medicine, especially in situations in which TGF-β may be detrimental, such as respiratory allergy. Further studies should evaluate the potential clinical applications of CM and MVs in equine lung diseases, such as RAO and other inflammatory disorders.

Closed form unsupervised registration of multi-temporal structure from motion-multiview stereo data using non-linearly weighted image features

NASA Astrophysics Data System (ADS)

Seers, T. D.; Hodgetts, D.

2013-12-01

Seers, T. D. & Hodgetts, D. School of Earth, Atmospheric and Environmental Sciences, University of Manchester, UK. M13 9PL. The detection of topological change at the Earth's surface is of considerable scholarly interest, allowing the quantification of the rates of geomorphic processes whilst providing lucid insights into the underlying mechanisms driving landscape evolution. In this regard, the past decade has witnessed the ever increasing proliferation of studies employing multi-temporal topographic data in within the geosciences, bolstered by continuing technical advancements in the acquisition and processing of prerequisite datasets. Provided by workers within the field of Computer Vision, multiview stereo (MVS) dense surface reconstructions, primed by structure-from-motion (SfM) based camera pose estimation represents one such development. Providing a cost effective, operationally efficient data capture medium, the modest requirement of a consumer grade camera for data collection coupled with the minimal user intervention required during post-processing makes SfM-MVS an attractive alternative to terrestrial laser scanners for collecting multi-temporal topographic datasets. However, in similitude to terrestrial scanner derived data, the co-registration of spatially coincident or partially overlapping scans produced by SfM-MVS presents a major technical challenge, particularly in the case of semi non-rigid scenes produced during topographic change detection studies. Moreover, the arbitrary scaling resulting from SfM ambiguity requires that a scale matrix must be estimated during the transformation, introducing further complexity into its formulation. Here, we present a novel, fully unsupervised algorithm which utilises non-linearly weighted image features for the solving the similarity transform (scale, translation rotation) between partially overlapping scans produced by SfM-MVS image processing. With the only initialization condition being partial intersection between input image sets, our method has major advantages over conventional iterative least squares minimization based methods (e.g. Iterative Closest Point variants), acting only on rigid areas of target scenes, being capable of reliably estimating the scaling factor and requiring no incipient estimation of the transformation to initialize (i.e. manual rough alignment). Moreover, because the solution is closed form, convergence is considerably more expedient that most iterative methods. It is hoped that the availability of improved co-registration routines, such as the one presented here, will facilitate the routine collection of multi-temporal topographic datasets by a wider range of geoscience practitioners.

Enhanced lysis by bispecific oncolytic measles viruses simultaneously using HER2/neu or EpCAM as target receptors

PubMed Central

Hanauer, Jan RH; Gottschlich, Lisa; Riehl, Dennis; Rusch, Tillmann; Koch, Vivian; Friedrich, Katrin; Hutzler, Stefan; Prüfer, Steffen; Friedel, Thorsten; Hanschmann, Kay-Martin; Münch, Robert C; Jost, Christian; Plückthun, Andreas; Cichutek, Klaus; Buchholz, Christian J; Mühlebach, Michael D

2016-01-01

To target oncolytic measles viruses (MV) to tumors, we exploit the binding specificity of designed ankyrin repeat proteins (DARPins). These DARPin-MVs have high tumor selectivity while maintaining excellent oncolytic potency. Stability, small size, and efficacy of DARPins allowed the generation of MVs simultaneously targeted to tumor marker HER2/neu and cancer stem cell (CSC) marker EpCAM. For optimization, the linker connecting both DARPins was varied in flexibility and length. Flexibility had no impact on fusion helper activity whereas length had. MVs with bispecific MV-H are genetically stable and revealed the desired double-target specificity. In vitro, the cytolytic activity of bispecific MVs was superior or comparable to mono-targeted viruses depending on the target cells. In vivo, therapeutic efficacy of the bispecific viruses was validated in an orthotopic ovarian carcinoma model revealing an effective reduction of tumor mass. Finally, the power of bispecific targeting was demonstrated on cocultures of different tumor cells thereby mimicking tumor heterogeneity in vitro, more closely reflecting real tumors. Here, bispecific excelled monospecific viruses in efficacy. DARPin-based targeting domains thus allow the generation of efficacious oncolytic viruses with double specificity, with the potential to handle intratumoral variation of antigen expression and to simultaneously target CSCs and the bulk tumor mass. PMID:27119117

Is compulsive buying related to materialism, depression or temperament? Findings from a sample of treatment-seeking patients with CB.

PubMed

Müller, Astrid; Claes, Laurence; Georgiadou, Ekaterini; Möllenkamp, Maike; Voth, Eva M; Faber, Ron J; Mitchell, James E; de Zwaan, Martina

2014-04-30

The aim of the present work was to examine the influence of reactive and regulatory temperament on compulsive buying (CB) in a sample of 102 patients (79 women, 23 men) with clinical CB. All participants answered the Compulsive Buying Scale (CBS), the Behavioral Inhibition System and Behavioral Activation System Scales (BIS/BAS), and the Effortful Control subscale (ATQ-EC) of the Adult Temperament Questionnaire-Short Form. Based on previous studies demonstrating that depression and materialism are linked with CB, in addition, the Patient Health Questionnaire depression scale (PHQ-9) and the Materialistic Values Scale (MVS) were administered. CBS scores were significantly correlated with the MVS, PHQ-9, and BAS scores. The findings of the hierarchical regression analysis, however, indicated that in the present sample of treatment-seeking patients the only significant association was found between CB and depression. The results highlight the prominent role of depression in CB. There is a need for longitudinal studies in order to answer the question whether depression is the cause or the consequence of CB. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

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

Stratton, Dan; Lange, Sigrun; Kholia, Sharad

Highlights: • Microvesiculating cells record loss of mass on a Quartz Crystal Microbalance. • Using the Quartz Crystal Microbalance microvesicles are measured at 0.24 pg. • The QCM-D reveals loss in viscoelastic properties in microvesiculating cells. - Abstract: Using a Quartz Crystal Microbalance with dissipation monitoring, QCM-D (label-free system) measuring changes in resonant frequency (Δf) that equate to mass deposited on a sensor, we showed the attachment, over a 60 min period, of a monolayer of PC3 cells to the gold electrodes of the quartz crystal sensor, which had been rendered hydrophilic. That MVs were released upon BzATP stimulation ofmore » cells was confirmed by NTA analysis (average 250 nm diameter), flow cytometry, showing high phosphatidylserine exposition and by fluorescent (Annexin V Alexa Fluor® 488-positive) and electron microscopy. Over a period of 1000s (16.7 min) during which early apoptosis increased from 4% plateauing at 10% and late apoptosis rose to 2%, the Δf increased 20 Hz, thereupon remaining constant for the last 1000s of the experiment. Using the Sauerbrey equation, the loss in mass, which corresponded to the release of 2.36 × 10{sup 6} MVs, was calculated to be 23 ng. We therefore estimated the mass of an MV to be 0.24 pg. With the deposition on the QCM-D of 3.5 × 10{sup 7} MVs over 200s, the decrease in Δf (Hz) gave an estimate of 0.235 pg per MV.« less

Multifunctional Ultra-Light Mg-Li Alloy Nanocomposites

DTIC Science & Technology

2012-08-20

unmanned or aerospace vehicles [1-4], tents and outdoor special clothing for turists going for long trips, professionals going to expiditions and...solders going for missions. Flexible Li-ion batteries with load bearing abilities could be attractive candidates for these applications due to their...from cyclic voltametry studies. Scans were done starting at open circuit potential and going to 0.01 V vs Li at scan rates of 0.5 mV/s, 0.1 mV/s, and

Benefit of a 360-degree horizontal turn following premedication with simethicone on image quality during gastroendoscopy: a randomized controlled trial

PubMed Central

Wang, Chunhua; Liu, Haiyan; Wang, Xiuming; Shen, Xiaochun; Yang, Yingying; Sun, Wenjing; Yan, Qingjun; Cao, Yan; Wang, Xueqin; Lan, Chunhui; Chen, Dongfeng

2015-01-01

Objectives: To investigate whether a 360-degree horizontal turn after oral premedication with simethicone improves the mucosal visibility during gastroendoscopic examination, and to determine the proper time to turn over the patient. Methods: This study involved 993 patients scheduled for gastroendoscopy. Just before gastroendoscopy, after oral premedication with simethicone, patients were randomly assigned to three groups: in Group A, patients waited for 20 min before gastroendoscopy; in Group B, patients were separately waited for 5/10/15/20 min and were then turned 360 degrees just before gastroendoscopy; in Group C, patients were immediately turned 360 degrees and then separately waited for 5/10/15/20 min before examination. The sum of the gastric mucosal visibility scores (MVS) was calculated after the examination. The MVS and proportion of images with higher visibility scores for the mucosal surface. Lower scores indicate better visibility of the mucosal surface. Results: In Groups B and Groups C, when waiting time more than 10 min had lower mean total MVS than Group A. The MVS of four subgroups of Group B were not different from those of Group C. Conclusion: Oral premedication with simethicone and immediately make a body posture change (turning over 360 degrees) then waiting for 10min can increase the image quality during gastroendoscopy and effectively decrease the premedication time. PMID:26064342

Benefit of a 360-degree horizontal turn following premedication with simethicone on image quality during gastroendoscopy: a randomized controlled trial.

PubMed

Wang, Chunhua; Liu, Haiyan; Wang, Xiuming; Shen, Xiaochun; Yang, Yingying; Sun, Wenjing; Yan, Qingjun; Cao, Yan; Wang, Xueqin; Lan, Chunhui; Chen, Dongfeng

2015-01-01

To investigate whether a 360-degree horizontal turn after oral premedication with simethicone improves the mucosal visibility during gastroendoscopic examination, and to determine the proper time to turn over the patient. This study involved 993 patients scheduled for gastroendoscopy. Just before gastroendoscopy, after oral premedication with simethicone, patients were randomly assigned to three groups: in Group A, patients waited for 20 min before gastroendoscopy; in Group B, patients were separately waited for 5/10/15/20 min and were then turned 360 degrees just before gastroendoscopy; in Group C, patients were immediately turned 360 degrees and then separately waited for 5/10/15/20 min before examination. The sum of the gastric mucosal visibility scores (MVS) was calculated after the examination. The MVS and proportion of images with higher visibility scores for the mucosal surface. Lower scores indicate better visibility of the mucosal surface. In Groups B and Groups C, when waiting time more than 10 min had lower mean total MVS than Group A. The MVS of four subgroups of Group B were not different from those of Group C. Oral premedication with simethicone and immediately make a body posture change (turning over 360 degrees) then waiting for 10min can increase the image quality during gastroendoscopy and effectively decrease the premedication time.

From picture to porosity of river bed material using Structure-from-Motion with Multi-View-Stereo

NASA Astrophysics Data System (ADS)

Seitz, Lydia; Haas, Christian; Noack, Markus; Wieprecht, Silke

2018-04-01

Common methods for in-situ determination of porosity of river bed material are time- and effort-consuming. Although mathematical predictors can be used for estimation, they do not adequately represent porosities. The objective of this study was to assess a new approach for the determination of porosity of frozen sediment samples. The method is based on volume determination by applying Structure-from-Motion with Multi View Stereo (SfM-MVS) to estimate a 3D volumetric model based on overlapping imagery. The method was applied on artificial sediment mixtures as well as field samples. In addition, the commonly used water replacement method was applied to determine porosities in comparison with the SfM-MVS method. We examined a range of porosities from 0.16 to 0.46 that are representative of the wide range of porosities found in rivers. SfM-MVS performed well in determining volumes of the sediment samples. A very good correlation (r = 0.998, p < 0.0001) was observed between the SfM-MVS and the water replacement method. Results further show that the water replacement method underestimated total sample volumes. A comparison with several mathematical predictors showed that for non-uniform samples the calculated porosity based on the standard deviation performed better than porosities based on the median grain size. None of the predictors were effective at estimating the porosity of the field samples.

Electron acceptors for anaerobic oxidation of methane drive microbial community structure and diversity in mud volcanoes.

PubMed

Ren, Ge; Ma, Anzhou; Zhang, Yanfen; Deng, Ye; Zheng, Guodong; Zhuang, Xuliang; Zhuang, Guoqiang; Fortin, Danielle

2018-04-06

Mud volcanoes (MVs) emit globally significant quantities of methane into the atmosphere, however, methane cycling in such environments is not yet fully understood, as the roles of microbes and their associated biogeochemical processes have been largely overlooked. Here, we used data from high-throughput sequencing of microbial 16S rRNA gene amplicons from six MVs in the Junggar Basin in northwest China to quantify patterns of diversity and characterize the community structure of archaea and bacteria. We found anaerobic methanotrophs and diverse sulfate- and iron-reducing microbes in all of the samples, and the diversity of both archaeal and bacterial communities was strongly linked to the concentrations of sulfate, iron and nitrate, which could act as electron acceptors in anaerobic oxidation of methane (AOM). The impacts of sulfate/iron/nitrate on AOM in the MVs were verified by microcosm experiments. Further, two representative MVs were selected to explore the microbial interactions based on phylogenetic molecular ecological networks. The sites showed distinct network structures, key species and microbial interactions, with more complex and numerous linkages between methane-cycling microbes and their partners being observed in the iron/sulfate-rich MV. These findings suggest that electron acceptors are important factors driving the structure of microbial communities in these methane-rich environments. © 2018 The Authors. Environmental Microbiology published by Society for Applied Microbiology and John Wiley & Sons Ltd.

Using the genome aggregation database, computational pathogenicity prediction tools, and patch clamp heterologous expression studies to demote previously published long QT syndrome type 1 mutations from pathogenic to benign.

PubMed

Clemens, Daniel J; Lentino, Anne R; Kapplinger, Jamie D; Ye, Dan; Zhou, Wei; Tester, David J; Ackerman, Michael J

2018-04-01

Mutations in the KCNQ1-encoded Kv7.1 potassium channel cause long QT syndrome (LQTS) type 1 (LQT1). It has been suggested that ∼10%-20% of rare LQTS case-derived variants in the literature may have been published erroneously as LQT1-causative mutations and may be "false positives." The purpose of this study was to determine which previously published KCNQ1 case variants are likely false positives. A list of all published, case-derived KCNQ1 missense variants (MVs) was compiled. The occurrence of each MV within the Genome Aggregation Database (gnomAD) was assessed. Eight in silico tools were used to predict each variant's pathogenicity. Case-derived variants that were either (1) too frequently found in gnomAD or (2) absent in gnomAD but predicted to be pathogenic by ≤2 tools were considered potential false positives. Three of these variants were characterized functionally using whole-cell patch clamp technique. Overall, there were 244 KCNQ1 case-derived MVs. Of these, 29 (12%) were seen in ≥10 individuals in gnomAD and are demotable. However, 157 of 244 MVs (64%) were absent in gnomAD. Of these, 7 (4%) were predicted to be pathogenic by ≤2 tools, 3 of which we characterized functionally. There was no significant difference in current density between heterozygous KCNQ1-F127L, -P477L, or -L619M variant-containing channels compared to KCNQ1-WT. This study offers preliminary evidence for the demotion of 32 (13%) previously published LQT1 MVs. Of these, 29 were demoted because of their frequent sighting in gnomAD. Additionally, in silico analysis and in vitro functional studies have facilitated the demotion of 3 ultra-rare MVs (F127L, P477L, L619M). Copyright © 2017 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

NJE; VAX-VMS IBM NJE network protocol emulator. [DEC VAX11/780; VAX-11 FORTRAN 77 (99%) and MACRO-11 (1%)

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

Engert, D.E.; Raffenetti, C.

NJE is communications software developed to enable a VAX VMS system to participate as an end-node in a standard IBM network by emulating the Network Job Entry (NJE) protocol. NJE supports job networking for the operating systems used on most large IBM-compatible computers (e.g., VM/370, MVS with JES2 or JES3, SVS, MVT with ASP or HASP). Files received by the VAX can be printed or saved in user-selected disk files. Files sent to the network can be routed to any network node for printing, punching, or job submission, or to a VM/370 user's virtual reader. Files sent from the VAXmore » are queued and transmitted asynchronously. No changes are required to the IBM software.DEC VAX11/780; VAX-11 FORTRAN 77 (99%) and MACRO-11 (1%); VMS 2.5; VAX11/780 with DUP-11 UNIBUS interface and 9600 baud synchronous modem..« less

Microvesicles derived from human umbilical cord mesenchymal stem cells facilitate tubular epithelial cell dedifferentiation and growth via hepatocyte growth factor induction.

PubMed

Ju, Guan-qun; Cheng, Jun; Zhong, Liang; Wu, Shuai; Zou, Xiang-yu; Zhang, Guang-yuan; Gu, Di; Miao, Shuai; Zhu, Ying-jian; Sun, Jie; Du, Tao

2015-01-01

During acute kidney injury (AKI), tubular cell dedifferentiation initiates cell regeneration; hepatocyte growth factor (HGF) is involved in modulating cell dedifferentiation. Mesenchymal stem cell (MSC)-derived microvesicles (MVs) deliver RNA into injured tubular cells and alter their gene expression, thus regenerating these cells. We boldly speculated that MVs might induce HGF synthesis via RNA transfer, thereby facilitating tubular cell dedifferentiation and regeneration. In a rat model of unilateral AKI, the administration of MVs promoted kidney recovery. One of the mechanisms of action is the acceleration of tubular cell dedifferentiation and growth. Both in vivo and in vitro, rat HGF expression in damaged rat tubular cells was greatly enhanced by MV treatment. In addition, human HGF mRNA present in MVs was delivered into rat tubular cells and translated into the HGF protein as another mechanism of HGF induction. RNase treatment abrogated all MV effects. In the in vitro experimental setting, the conditioned medium of MV-treated injured tubular cells, which contains a higher concentration of HGF, strongly stimulated cell dedifferentiation and growth, as well as Erk1/2 signaling activation. Intriguingly, these effects were completely abrogated by either c-Met inhibitor or MEK inhibitor, suggesting that HGF induction is a crucial contributor to the acceleration of cell dedifferentiation and growth. All these findings indicate that MV-induced HGF synthesis in damaged tubular cells via RNA transfer facilitates cell dedifferentiation and growth, which are important regenerative mechanisms.

Proteoliposomes as matrix vesicles’ biomimetics to study the initiation of skeletal mineralization

PubMed Central

Simão, A.M.S.; Yadav, M.C.; Ciancaglini, P.; Millán, J.L.

2017-01-01

During the process of endochondral bone formation, chondrocytes and osteoblasts mineralize their extracellular matrix by promoting the formation of hydroxyapatite (HA) seed crystals in the sheltered interior of membrane-limited matrix vesicles (MVs). Ion transporters control the availability of phosphate and calcium needed for HA deposition. The lipidic microenvironment in which MV-associated enzymes and transporters function plays a crucial physiological role and must be taken into account when attempting to elucidate their interplay during the initiation of biomineralization. In this short mini-review, we discuss the potential use of proteoliposome systems as chondrocyte- and osteoblast-derived MVs biomimetics, as a means of reconstituting a phospholipid microenvironment in a manner that recapitulates the native functional MV microenvironment. Such a system can be used to elucidate the interplay of MV enzymes during catalysis of biomineralization substrates and in modulating in vitro calcification. As such, the enzymatic defects associated with disease-causing mutations in MV enzymes could be studied in an artificial vesicular environment that better mimics their in vivo biological milieu. These artificial systems could also be used for the screening of small molecule compounds able to modulate the activity of MV enzymes for potential therapeutic uses. Such a nanovesicular system could also prove useful for the repair/treatment of craniofacial and other skeletal defects and to facilitate the mineralization of titanium-based tooth implants. PMID:20401430

Proteoliposomes as matrix vesicles' biomimetics to study the initiation of skeletal mineralization.

PubMed

Simão, A M S; Yadav, M C; Ciancaglini, P; Millán, J L

2010-03-01

During the process of endochondral bone formation, chondrocytes and osteoblasts mineralize their extracellular matrix by promoting the formation of hydroxyapatite (HA) seed crystals in the sheltered interior of membrane-limited matrix vesicles (MVs). Ion transporters control the availability of phosphate and calcium needed for HA deposition. The lipidic microenvironment in which MV-associated enzymes and transporters function plays a crucial physiological role and must be taken into account when attempting to elucidate their interplay during the initiation of biomineralization. In this short mini-review, we discuss the potential use of proteoliposome systems as chondrocyte- and osteoblast-derived MVs biomimetics, as a means of reconstituting a phospholipid microenvironment in a manner that recapitulates the native functional MV microenvironment. Such a system can be used to elucidate the interplay of MV enzymes during catalysis of biomineralization substrates and in modulating in vitro calcification. As such, the enzymatic defects associated with disease-causing mutations in MV enzymes could be studied in an artificial vesicular environment that better mimics their in vivo biological milieu. These artificial systems could also be used for the screening of small molecule compounds able to modulate the activity of MV enzymes for potential therapeutic uses. Such a nanovesicular system could also prove useful for the repair/treatment of craniofacial and other skeletal defects and to facilitate the mineralization of titanium-based tooth implants.

A new theory of phylogeny inference through construction of multidimensional vector space.

PubMed

Kitazoe, Y; Kurihara, Y; Narita, Y; Okuhara, Y; Tominaga, A; Suzuki, T

2001-05-01

Here, a new theory of molecular phylogeny is developed in a multidimensional vector space (MVS). The molecular evolution is represented as a successive splitting of branch vectors in the MVS. The end points of these vectors are the extant species and indicate the specific directions reflected by their individual histories of evolution in the past. This representation makes it possible to infer the phylogeny (evolutionary histories) from the spatial positions of the end points. Search vectors are introduced to draw out the groups of species distributed around them. These groups are classified according to the nearby order of branches with them. A law of physics is applied to determine the species positions in the MVS. The species are regarded as the particles moving in time according to the equation of motion, finally falling into the lowest-energy state in spite of their randomly distributed initial condition. This falling into the ground state results in the construction of an MVS in which the relative distances between two particles are equal to the substitution distances. The species positions are obtained prior to the phylogeny inference. Therefore, as the number of species increases, the species vectors can be more specific in an MVS of a larger size, such that the vector analysis gives a more stable and reliable topology. The efficacy of the present method was examined by using computer simulations of molecular evolution in which all the branch- and end-point sequences of the trees are known in advance. In the phylogeny inference from the end points with 100 multiple data sets, the present method consistently reconstructed the correct topologies, in contrast to standard methods. In applications to 185 vertebrates in the alpha-hemoglobin, the vector analysis drew out the two lineage groups of birds and mammals. A core member of the mammalian radiation appeared at the base of the mammalian lineage. Squamates were isolated from the bird lineage to compose the outgroup, while the other living reptilians were directly coupled with birds without forming any sister groups. This result is in contrast to the morphological phylogeny and is also different from those of recent molecular analyses.

Pro-angiogenic capacities of microvesicles produced by skin wound myofibroblasts.

PubMed

Merjaneh, Mays; Langlois, Amélie; Larochelle, Sébastien; Cloutier, Chanel Beaudoin; Ricard-Blum, Sylvie; Moulin, Véronique J

2017-08-01

Wound healing is a very highly organized process where numerous cell types are tightly regulated to restore injured tissue. Myofibroblasts are cells that produce new extracellular matrix and contract wound edges. We previously reported that the human myofibroblasts isolated from normal wound (WMyos) produced microvesicles (MVs) in the presence of the serum. In this study, MVs were further characterized using a proteomic strategy and potential functions of the MVs were determined. MV proteins isolated from six WMyo populations were separated using two-dimensional differential gel electrophoresis. Highly conserved spots were selected and analyzed using mass spectrometry resulting in the identification of 381 different human proteins. Using the DAVID database, clusters of proteins involved in cell motion, apoptosis and adhesion, but also in extracellular matrix production (21 proteins, enrichment score: 3.32) and in blood vessel development/angiogenesis (19 proteins, enrichment score: 2.66) were identified. Another analysis using the functional enrichment analysis tool FunRich was consistent with these results. While the action of the myofibroblasts on extracellular matrix formation is well known, their angiogenic potential is less studied. To further characterize the angiogenic activity of the MVs, they were added to cultured microvascular endothelial cells to evaluate their influence on cell growth and migration using scratch test and capillary-like structure formation in Matrigel ® . The addition of a MV-enriched preparation significantly increased endothelial cell growth, migration and capillary formation compared with controls. The release of microvesicles by the wound myofibroblasts brings new perspectives to the field of communication between cells during the normal healing process.

Hierarchical Regularization of Polygons for Photogrammetric Point Clouds of Oblique Images

NASA Astrophysics Data System (ADS)

Xie, L.; Hu, H.; Zhu, Q.; Wu, B.; Zhang, Y.

2017-05-01

Despite the success of multi-view stereo (MVS) reconstruction from massive oblique images in city scale, only point clouds and triangulated meshes are available from existing MVS pipelines, which are topologically defect laden, free of semantical information and hard to edit and manipulate interactively in further applications. On the other hand, 2D polygons and polygonal models are still the industrial standard. However, extraction of the 2D polygons from MVS point clouds is still a non-trivial task, given the fact that the boundaries of the detected planes are zigzagged and regularities, such as parallel and orthogonal, cannot preserve. Aiming to solve these issues, this paper proposes a hierarchical polygon regularization method for the photogrammetric point clouds from existing MVS pipelines, which comprises of local and global levels. After boundary points extraction, e.g. using alpha shapes, the local level is used to consolidate the original points, by refining the orientation and position of the points using linear priors. The points are then grouped into local segments by forward searching. In the global level, regularities are enforced through a labeling process, which encourage the segments share the same label and the same label represents segments are parallel or orthogonal. This is formulated as Markov Random Field and solved efficiently. Preliminary results are made with point clouds from aerial oblique images and compared with two classical regularization methods, which have revealed that the proposed method are more powerful in abstracting a single building and is promising for further 3D polygonal model reconstruction and GIS applications.

Novel true-motion estimation algorithm and its application to motion-compensated temporal frame interpolation.

PubMed

Dikbas, Salih; Altunbasak, Yucel

2013-08-01

In this paper, a new low-complexity true-motion estimation (TME) algorithm is proposed for video processing applications, such as motion-compensated temporal frame interpolation (MCTFI) or motion-compensated frame rate up-conversion (MCFRUC). Regular motion estimation, which is often used in video coding, aims to find the motion vectors (MVs) to reduce the temporal redundancy, whereas TME aims to track the projected object motion as closely as possible. TME is obtained by imposing implicit and/or explicit smoothness constraints on the block-matching algorithm. To produce better quality-interpolated frames, the dense motion field at interpolation time is obtained for both forward and backward MVs; then, bidirectional motion compensation using forward and backward MVs is applied by mixing both elegantly. Finally, the performance of the proposed algorithm for MCTFI is demonstrated against recently proposed methods and smoothness constraint optical flow employed by a professional video production suite. Experimental results show that the quality of the interpolated frames using the proposed method is better when compared with the MCFRUC techniques.

New discoveries of mud volcanoes on the Moroccan Atlantic continental margin (Gulf of Cádiz): morpho-structural characterization

NASA Astrophysics Data System (ADS)

León, Ricardo; Somoza, Luis; Medialdea, Teresa; Vázquez, Juan Tomás; González, Francisco Javier; López-González, Nieves; Casas, David; del Pilar Mata, María; del Fernández-Puga, María Carmen; Giménez-Moreno, Carmen Julia; Díaz-del-Río, Víctor

2012-12-01

During the MVSEIS-08 cruise of 2008, ten new mud volcanoes (MVs) were discovered on the offshore Moroccan continental margin (Gulf of Cádiz) at water depths between 750 and 1,600 m, using multibeam bathymetry, backscatter imagery, high-resolution seismic and gravity core data. Mud breccias were recovered in all cases, attesting to the nature of extrusion of these cones. The mud volcanoes are located in two fields: the MVSEIS, Moundforce, Pixie, Las Negras, Madrid, Guadix, Almanzor and El Cid MVs in the western Moroccan field, where mud volcanoes have long been suspected but to date not identified, and the Boabdil and Al Gacel MVs in the middle Moroccan field. Three main morphologies were observed: asymmetric, sub-circular and flat-topped cone-shaped types, this being the first report of asymmetric morphologies in the Gulf of Cádiz. Based on morpho-structural analysis, the features are interpreted to result from (1) repeated constructive (expulsion of fluid mud mixtures) and destructive (gravity-induced collapse and submarine landsliding) episodes and (2) interaction with bottom currents.

Microvesicles as mediators of intercellular communication in cancer.

PubMed

Antonyak, Marc A; Cerione, Richard A

2014-01-01

The discovery that cancer cells generate large membrane-enclosed packets of epigenetic information, known as microvesicles (MVs), that can be transferred to other cells and influence their behavior (Antonyak et al., Small GTPases 3:219-224, 2012; Cocucci et al., Trends Cell Biol 19:43-51, 2009; Rak, Semin Thromb Hemost 36:888-906, 2010; Skog et al., Nat Cell Biol 10:1470-1476, 2008) has added a unique perspective to the classical paracrine signaling paradigm. This is largely because, in addition to growth factors and cytokines, MVs contain a variety of components that are not usually thought to be released into the extracellular environment by viable cells including plasma membrane-associated proteins, cytosolic- and nuclear-localized proteins, as well as nucleic acids, particularly RNA transcripts and micro-RNAs (Skog et al., Nat Cell Biol 10:1470-1476, 2008; Al-Nedawi et al., Nat Cell Biol 10:619-624, 2008; Antonyak et al., Proc Natl Acad Sci U S A 108:4852-4857, 2011; Balaj et al., Nat Commun 2:180, 2011; Choi et al., J Proteome Res 6:4646-4655, 2007; Del Conde et al., Blood 106:1604-1611, 2005; Gallo et al., PLoS One 7:e30679, 2012; Graner et al., FASEB J 23:1541-1557, 2009; Grange et al., Cancer Res 71:5346-5356, 2011; Hosseini-Beheshti et al., Mol Cell Proteomics 11:863-885, 2012; Martins et al., Curr Opin Oncol 25:66-75, 2013; Noerholm et al., BMC Cancer 12:22, 2012; Zhuang et al., EMBO J 31:3513-3523, 2012). When transferred between cancer cells, MVs have been shown to stimulate signaling events that promote cell growth and survival (Al-Nedawi et al., Nat Cell Biol 10:619-624, 2008). Cancer cell-derived MVs can also be taken up by normal cell types that surround the tumor, an outcome that helps shape the tumor microenvironment, trigger tumor vascularization, and even confer upon normal recipient cells the transformed characteristics of a cancer cell (Antonyak et al., Proc Natl Acad Sci U S A 108:4852-4857, 2011; Martins et al., Curr Opin Oncol 25:66-75, 2013; Al-Nedawi et al., Proc Natl Acad Sci U S A 106:3794-3799, 2009; Ge et al., Cancer Microenviron 5:323-332, 2012). Thus, the production of MVs by cancer cells plays crucial roles in driving the expansion of the primary tumor. However, it is now becoming increasingly clear that MVs are also stable in the circulation of cancer patients, where they can mediate long-range effects and contribute to the formation of the pre-metastatic niche, an essential step in metastasis (Skog et al., Nat Cell Biol 10:1470-1476, 2008; Noerholm et al., BMC Cancer 12:22, 2012; Peinado et al., Nat Med 18:883-891, 2012; Piccin et al., Blood Rev 21:157-171, 2007; van der Vos et al., Cell Mol Neurobiol 31:949-959, 2011). These findings, when taken together with the fact that MVs are being aggressively pursued as diagnostic markers, as well as being considered as potential targets for intervention against cancer (Antonyak et al., Small GTPases 3:219-224, 2012; Hosseini-Beheshti et al., Mol Cell Proteomics 11:863-885, 2012; Martins et al., Curr Opin Oncol 25:66-75, 2013; Ge et al., Cancer Microenviron 5:323-332, 2012; Peinado et al., Nat Med 18:883-891, 2012; Piccin et al., Blood Rev 21:157-171, 2007; Al-Nedawi et al., Cell Cycle 8:2014-2018, 2009; Cocucci and Meldolesi, Curr Biol 21:R940-R941, 2011; D'Souza-Schorey and Clancy, Genes Dev 26:1287-1299, 2012; Shao et al., Nat Med 18:1835-1840, 2012), point to critically important roles for MVs in human cancer progression that can potentially be exploited to develop new targeted approaches for treating this disease.

Metal vapor vacuum arc switching - Applications and results. [for launchers

NASA Technical Reports Server (NTRS)

Cope, D.; Mongeau, P.

1984-01-01

The design of metal-vapor vacuum-arc switches (MVSs) for electromagnetic launchers is discussed, and preliminary results are presented for an experimental MVS. The general principles of triggered-vacuum-gap and vacuum-interrupter MVSs are reviewed, and the requirements of electromagnetic launchers are analyzed. High-current design problems such as electrode erosion, current sharing, magnetic effects, and thermal effects are examined. The experimental MVS employs stainless-steel flanges, a glass vacuum vessel, an adjustable electrode gap, autonomous internal magnetic-field coils, and a tungsten-pin trigger assembly. Some results from tests without magnetic augmentation are presented graphically.

Electrochemistry and Spectroelectrochemistry of 1,8-Naphthalene and 1,8- Anthracene-Linked Cofacial Binuclear Metallophthalocynanines. New Mixed Valence Metallopthalocyanines

DTIC Science & Technology

1990-05-10

slope of a plot of peak current vs. sweep rate to the charge should be equal to nF/4RT, where n is the number of electrons per adsorbed species and...overlapping waves. b) Values ofAEp : (Ep. - Epe) are given at a potential sweep rate of 50 mV/s. c) data fom ref.8g. d) Potentials are approximate because...cyclic voltametry at 200, 100, 50 and 20 mV/s, Average data being E : (Eps + Epc)/2 are reported. Data in parenthesis are estimated from overlapping

A Meta-Analysis of Circulating Microvesicles in Patients with Myocardial Infarction.

PubMed

Wang, Zhida; Cai, Wang; Hu, Shaolan; Xia, Yufei; Wang, Yao; Zhang, Qi; Chen, Liming

2017-07-10

Cell-derived microvesicles (MVs) are vesicles released from activated or apoptotic cells. However, the levels of MVs in myocardial infarction have been found inconsistent in researches. To assess the association between MVs and myocardial infarction by conducting a meta-analysis. A systematic literature search on PubMed, Embase, Cochran, Google Scholar electronic database was conducted. Comparison of the MVs levels between myocardial infarction patients and healthy persons were included in our study. Standard Mean Difference (SMD) and 95% confidence interval (CI) in groups were calculated and meta-analyzed. 11 studies with a total of 436 participants were included. Compared with the health persons, AMVs [SMD = 3.65, 95% CI (1.03, 6.27)], PMVs [SMD = 2.88, 95% CI (1.82, 3.93),] and EMVs [SMD = 2.73, 95% CI (1.13, 4.34)], levels were higher in patients with myocardial infarction. However, LMVs levels [SMD = 0.73, 95% CI (-0.57, 2.03)] were not changed significantly in patients with myocardial infarction. AMVs, PMVs and EMVs might be potential biomarkers for myocardial infarction. As microvesículas derivadas de células (MVs) são vesículas liberadas de células ativadas ou apoptóticas. No entanto, os níveis de MVs no infarto do miocárdio foram encontrados inconsistentes nas pesquisas. Avaliar a associação entre MV e infarto do miocárdio por meio de uma meta-análise. Foi realizada uma pesquisa sistemática na literatura em PubMed, Embase, Cochran e no banco de dados eletrônico do Google Scholar. Uma comparação dos níveis de MV entre pacientes com infarto do miocárdio e pessoas saudáveis foi incluída no nosso estudo. A Diferença Média Padrão (DMP) e o intervalo de confiança (IC) de 95% nos grupos foram calculadas e meta-analisadas. Foram incluídos 11 estudos com um total de 436 participantes. Em comparação com as pessoas saudáveis, as MVA [DMP = 3,65, IC 95% (1,03, 6,27)], MVPs [DMP = 2,88, IC 95% (1,82, 3,93)] e MVEs [DMP = 2,73, IC 95% (1,13, 4.34)], foram maiores em pacientes com infarto do miocárdio. No entanto, os níveis de MVL [DMP = 0,73, IC 95% (-0,57, 2,03)] não foram alterados significativamente em pacientes com infarto do miocárdio. MVAs, MVPs e MVEs podem ser biomarcadores potenciais para o infarto do miocárdio.

Real-time three-dimensional transesophageal echocardiography in valve disease: comparison with surgical findings and evaluation of prosthetic valves.

PubMed

Sugeng, Lissa; Shernan, Stanton K; Weinert, Lynn; Shook, Doug; Raman, Jai; Jeevanandam, Valluvan; DuPont, Frank; Fox, John; Mor-Avi, Victor; Lang, Roberto M

2008-12-01

Recently, a novel real-time 3-dimensional (3D) matrix-array transesophageal echocardiographic (3D-MTEE) probe was found to be highly effective in the evaluation of native mitral valves (MVs) and other intracardiac structures, including the interatrial septum and left atrial appendage. However, the ability to visualize prosthetic valves using this transducer has not been evaluated. Moreover, the diagnostic accuracy of this new technology has never been validated against surgical findings. This study was designed to (1) assess the quality of 3D-MTEE images of prosthetic valves and (2) determine the potential value of 3D-MTEE imaging in the preoperative assessment of valvular pathology by comparing images with surgical findings. Eighty-seven patients undergoing clinically indicated transesophageal echocardiography were studied. In 40 patients, 3D-MTEE images of prosthetic MVs, aortic valves (AVs), and tricuspid valves (TVs) were scored for the quality of visualization. For both MVs and AVs, mechanical and bioprosthetic valves, the rings and leaflets were scored individually. In 47 additional patients, intraoperative 3D-MTEE diagnoses of MV pathology obtained before initiating cardiopulmonary bypass were compared with surgical findings. For the visualization of prosthetic MVs and annuloplasty rings, quality was superior compared with AV and TV prostheses. In addition, 3D-MTEE imaging had 96% agreement with surgical findings. Three-dimensional matrix-array transesophageal echocardiographic imaging provides superb imaging and accurate presurgical evaluation of native MV pathology and prostheses. However, the current technology is less accurate for the clinical assessment of AVs and TVs. Fast acquisition and immediate online display will make this the modality of choice for MV surgical planning and postsurgical follow-up.

Match and mismatch between opening area and resistance in mild and moderate rheumatic mitral stenosis.

PubMed

El-Dosouky, Ibtesam Ibrahim

2016-12-01

Mitral valve resistance (MVR) is a hemodynamic consequence of mitral stenosis (MS), but it has no clear threshold with a shortage of data to be reliable. We aimed to investigate match and mismatch between opening area and resistance especially in patients with moderate and mild MS. This study comprised 88 patients with moderate and mild rheumatic MS. Transthoracic echocardiographic study estimated the following: mitral valve area (MVA) by both planimetry (2D) and pressure half-time (PHT), mitral valve score (MVS), mean transmitral pressure gradient (MPG), diastolic filling time (DFT), left ventricular out flow tract diameter (LVOTd) and velocity-time integral (LVOTvti), and MVR = MPG/aortic flow ratio [(LVOTd) (LVOTvti)/DFT] in dynes·s/cm 5 . Patients were classified into two groups: group 1 (51 patients) with matched MVR and group 2 (37 patients) with mismatched higher MVR. In the matched group, moderate MS showed MVR <105 dynes·s/cm 5 and <76dynes·s/cm 5 with mild MS. Group 2 compared to group 1 had higher NYHA class (1.4±0.6 vs 1.2±0.4, P<.05) and higher MVS (8.1±1.8 vs 7±0.9, P<.05). MVR showed positive correlation with MVS (r=.5, P<.05), and logistic regression analysis showed that MVS is the only independent predictor of the MVR severity in the mismatched group (i.e., with higher MVR compared to the ROC analysis results) (B±SE=6.997±2.826, t=2.476, 95% CI 1.241±12.752 with an odds ratio=0.412, P<.05). On investigating match and mismatch between opening area and resistance, the only independent predictor of mismatch is the mitral valve score. © 2016, Wiley Periodicals, Inc.

Fluorescent Immortalized Human Adipose Derived Stromal Cells (hASCs-TS/GFP+) for Studying Cell Drug Delivery Mediated by Microvesicles.

PubMed

Cocce, Valentina; Balducci, Luigi; Falchetti, Maria L; Pascucci, Luisa; Ciusani, Emilio; Brini, Anna T; Sisto, Francesca; Piovani, Giovanna; Alessandri, Giulio; Parati, Eugenio; Cabeza, Laura; Pessina, Augusto

2017-11-24

A new tool for the drug delivery is based on the use of Mesenchymal Stromal Cells (MSCs) loaded in vitro with anti-cancer drugs. Unfortunately, the restricted lifespan of MSCs represents a significant limitation to produce them in high amounts and for long time studies. Immortalized MSCs from adipose tissue (hASCs) have been generated as good source of cells with stable features. These cells could improve the development of standardized procedures for both in vitro and preclinical studies. Furthermore they facilitate procedures for preparing large amounts of secretome containing microvesicles (MVs). We used human adipose tissue derived MSCs immortalized with hTERT+SV40 (TS) genes and transfected with GFP (hASCs-TS/GFP+). This line was investigated for its ability to uptake and release anticancer drugs. Microvesicles associated to paclitaxel (MVs/PTX) were isolated, quantified, and tested on pancreatic cancer cells. The line hASCs-TS/GFP+ maintained the main mesenchymal characters and was able to uptake and release, in active form, both paclitaxel and gemcitabine. From paclitaxel loaded hASCs-TS/GFP+ cells were isolated microvesicles in sufficient amount to inhibit "in vitro" the proliferation of pancreatic tumor cells. Our study suggests that human immortalized MSCs could be used for a large scale production of cells for mediated drug delivery. Moreover, the secretion of drug-associated MVs could represent a new way for producing new drug formulation by "biogenesis". In the context of the "advanced cell therapy procedure", the MVs/PTX production would use less resource and time and it could possibly contribute to simplification of GMP procedures. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Application of structure from motion to digitized historical airphotos to document geomorphic change over the past century

NASA Astrophysics Data System (ADS)

Roberti, Gioachino; Ward, Brent; van Wyk de Vries, Benjamin; Perotti, Luigi; Giardino, Marco; Friele, Pierre; Clague, John

2017-04-01

Topographic modeling is becoming more accessible due to the development of structure from motion (SFM), and multi-view stereo (MVS) image matching algorithms in digital photogrammetry. Many studies are utilizing SFM-MVS with either UAV or hand-held consumer-grade digital cameras. However, little work has been done in using SFM-MVS with digitized historical air photos. Large databases of historical airphotos are available in university, public, and government libraries, commonly as paper copies. In many instances, the photos are in poor condition (i.e. deformed by humidity, scratched, or annotated). In addition, the negatives, as well as metadata on the camera and the flight mission, may be missing. Processing such photos using classic stereo-photogrammetry is difficult and in many instances impossible. Yet these photos can provide a valuable archive of geomorphic changes. In this study, we digitized over 1000 vertical air photos of the Mount Meager massif (British Columbia, Canada), acquired during flights between 1947 and 2006. We processed the scans using the commercial SFM-MVS software package PhotoScan. PhotoScan provided high-quality orthophotos (0.42-1.13 m/pixel) and DTMs (1-5 m/pixel). We used the orthophotos to document glacier retreat and deep-seated gravitational deformation over the 60-year photo period. Notably, we reconstructed geomorphic changes that led to the very large (˜50 x 106 m 3) 2010 failure of the south flank of Meager Peak and also documented other unstable areas that might fail catastrophically in the future. This technique can be applied to other photosets to provide rapid high-quality cartographic products that allow researchers to track landscape changes over large areas over the past century.

A study of Japanese landscapes using structure from motion derived DSMs and DEMs based on historical aerial photographs: New opportunities for vegetation monitoring and diachronic geomorphology

NASA Astrophysics Data System (ADS)

Gomez, Christopher; Hayakawa, Yuichi; Obanawa, Hiroyuki

2015-08-01

SfM-MVS (Structure from Motion and Multiple-View Stereophotogrammetry) is part of a series of technological progresses brought to the field of earth-sciences during the last decade or so, which has allowed geoscientists to collect unprecedented precise and extensive DSMs (Digital Surface Model) for virtually no cost, rivaling LiDAR (Light Detection and Ranging) technology. Previous work on SfM-MVS in geosciences has been solely exploring data acquired for the purpose of SfM-MVS, but no research has been done in the exploration of photographic archives for geomorphological purposes. Therefore, the present publications aims to present the usage of SfM-MVS applied to historical aerial photographs in Japan, in order to (1) demonstrate the potentials to extract topographical and vegetation data and (2) to present the potential for chronological analysis of landscape evolution. SfM-MVS was implemented on black-and-white and colour aerial photographs of 1966, 1976, 1996, 2006 and 2013, using the commercial software Photoscanpro®. Firstly, the photographs were masked, tied to GPS points; secondly the positions of the cameras and the 3D pointcloud were calculated; and thirdly the 3D surface was created. Data were then exported in the GIS software ArcGIS for analysis. Results also proved satisfactory for the reconstruction of 3D past-geomorphological landscapes in coastal areas, riverine areas, and in hilly and volcanic areas. They also prove that the height of trees and large vegetation features can also be calculated from aerial photographs alone. Diachronic analysis of the evolution in 3D landforms presented more difficulties, because the resolution of the early photographs was lower than the recent ones. Volume and surface calculations should therefore be conducted carefully. Although the method holds merit and great promise in the exploration of active landscapes that have widely changed during the 20th century; the authors have also reflected on the issues linked to large datasets, mostly because the processing of these large datasets is still in need of improvement. Moreover there is no proof that an ever increasing resolution brings any major advance to the geomorphological paradigms.

Ada Compiler Validation Summary Report: Certificate Number: 890420W1. 10074 International Business Machines Corporation, IBM Development System for the Ada Language MVS Ada Compiler, Version 2.1.1 IBM 4381 (Host and Target)

DTIC Science & Technology

1989-04-20

20. ARS1AAI . (Contimne on reverse side olnetessary *rwenPtif) by bfoci nur~be’) International Business Machines Corporation, IBM Development System...Number: AVF-VSR-261.0789 89-01-26-TEL Ada COMPILER VALIDATION SUMMARY REPORT: Certificate Number: 890420W1.10074 International Business Machines...computer. The compiler was tested using command scripts provided by International Business Machines Corporation and reviewed by the validation team. The

A recent Cleanroom success story: The Redwing project

NASA Technical Reports Server (NTRS)

Hausler, Philip A.

1992-01-01

Redwing is the largest completed Cleanroom software engineering project in IBM, both in terms of lines of code and project staffing. The product provides a decision-support facility that utilizes artificial intelligence (AI) technology for predicting and preventing complex operating problems in an MVS environment. The project used the Cleanroom process for development and realized a defect rate of 2.6 errors/KLOC, measured from first execution. This represents the total amount of errors that were found in testing and installation at three field test sites. Development productivity was 486 LOC/PM, which included all development labor expended in design specification through completion of incremental testing. In short, the Redwing team produced a complex systems software product with an extraordinarily low error rate, while maintaining high productivity. All of this was accomplished by a project team using Cleanroom for the first time. An 'introductory implementation' of Cleanroom was defined and used on Redwing. This paper describes the quality and productivity results, the Redwing project, and how Cleanroom was implemented.

Enhancements to the IBM version of COSMIC/NASTRAN

NASA Technical Reports Server (NTRS)

Brown, W. Keith

1989-01-01

Major improvements were made to the IBM version of COSMIC/NASTRAN by RPK Corporation under contract to IBM Corporation. These improvements will become part of COSMIC's IBM version and will be available in the second quarter of 1989. The first improvement is the inclusion of code to take advantage of IBM's new Vector Facility (VF) on its 3090 machines. The remaining improvements are modifications that will benefit all users as a result of the extended addressing capability provided by the MVS/XA operating system. These improvements include the availability of an in-memory data base that potentially eliminates the need for I/O to the PRIxx disk files. Another improvement is the elimination of multiple load modules that have to be loaded for every link switch within NASTRAN. The last improvement allows for NASTRAN to execute above the 16 mega-byte line. This improvement allows for NASTRAN to have access to 2 giga-bytes of memory for open core and the in-memory data base.

Ex Vivo Methods for Informing Computational Models of the Mitral Valve

PubMed Central

Bloodworth, Charles H.; Pierce, Eric L.; Easley, Thomas F.; Drach, Andrew; Khalighi, Amir H.; Toma, Milan; Jensen, Morten O.; Sacks, Michael S.; Yoganathan, Ajit P.

2016-01-01

Computational modeling of the mitral valve (MV) has potential applications for determining optimal MV repair techniques and risk of recurrent mitral regurgitation. Two key concerns for informing these models are (1) sensitivity of model performance to the accuracy of the input geometry, and, (2) acquisition of comprehensive data sets against which the simulation can be validated across clinically relevant geometries. Addressing the first concern, ex vivo micro-computed tomography (microCT) was used to image MVs at high resolution (~40 micron voxel size). Because MVs distorted substantially during static imaging, glutaraldehyde fixation was used prior to microCT. After fixation, MV leaflet distortions were significantly smaller (p<0.005), and detail of the chordal tree was appreciably greater. Addressing the second concern, a left heart simulator was designed to reproduce MV geometric perturbations seen in vivo in functional mitral regurgitation and after subsequent repair, and maintain compatibility with microCT. By permuting individual excised ovine MVs (n=5) through each state (healthy, diseased and repaired), and imaging with microCT in each state, a comprehensive data set was produced. Using this data set, work is ongoing to construct and validate high-fidelity MV biomechanical models. These models will seek to link MV function across clinically relevant states. PMID:27699507

EMMPRIN/CD147-encriched membrane vesicles released from malignant human testicular germ cells increase MMP production through tumor-stroma interaction.

PubMed

Milia-Argeiti, Eleni; Mourah, Samia; Vallée, Benoit; Huet, Eric; Karamanos, Nikos K; Theocharis, Achilleas D; Menashi, Suzanne

2014-08-01

Elevated levels of EMMPRIN/CD147 in cancer tissues have been correlated with tumor progression but the regulation of its expression is not yet understood. Here, the regulation of EMMPRIN expression was investigated in testicular germ cell tumor (TGCTs) cell lines. EMMPRIN expression in seminoma JKT-1 and embryonal carcinoma NT2/D1 cell lines was determined by Western blot, immunofluorescence and qRT-PCR. Membrane vesicles (MVs) secreted from these cells, treated or not with EMMPRIN siRNA, were isolated by differential centrifugations of their conditioned medium. MMP-2 was analyzed by zymography and qRT-PCR. The more aggressive embryonic carcinoma NT2/D1 cells expressed more EMMPRIN mRNA than the seminoma JKT-1 cells, but surprisingly contained less EMMPRIN protein, as determined by immunoblotting and immunostaining. The protein/mRNA discrepancy was not due to accelerated protein degradation in NT2/D1 cells, but by the secretion of EMMPRIN within MVs, as the vesicles released from NT2/D1 contained considerably more EMMPRIN than those released from JKT-1. EMMPRIN-containing MVs obtained from NT2/D1, but not from EMMPRIN-siRNA treated NT2/D1, increased MMP-2 production in fibroblasts to a greater extent than those from JKT-1 cells. The data presented show that the more aggressive embryonic carcinoma cells synthesize more EMMPRIN than seminoma cells, but which they preferentially target to secreted MVs, unlike seminoma cells which retain EMMPRIN within the cell membrane. This cellular event points to a mechanism by which EMMPRIN expressed by malignant testicular cells can exert its MMP inducing effect on distant cells within the tumor microenvironment to promote tumor invasion. This article is part of a Special Issue entitled Matrix-mediated cell behaviour and properties. Copyright © 2014 Elsevier B.V. All rights reserved.

Macrovoid Defect Growth during Evaporative Casting of Polymeric Membranes

NASA Technical Reports Server (NTRS)

Greenberg, A. R.; Khare, V. P.; Zartman, J.; Krantz, W. B.; Todd, P.

2003-01-01

Macrovoid (MV) formation is a significant problem in evaporatively cast polymeric membranes. MVs are large, elongated or teardrop-shaped pores (10-50 micron) that can impair membrane structural integrity. Although MVs have been extensively studied, there is no general agreement on the mechanisms governing MV growth. Recently, our research group has formulated the solutocapillary convection (SC) hypothesis, which contends that MV growth involves three principal forces: a Marangoni force generated by surface tension gradients within the MV interface, a viscous drag force, and a gravitationally induced body force. Two sets of complementary experiments were conducted to test the SC hypothesis. Ground-based videomicroscopy flow-visualization (VMFV) was utilized to measure the flow velocities at the MV-casting solution interface and deep within the casting solution. The measurements were performed with casting solutions containing 10 wt% cellulose acetate (CA), 30 wt% H2O, 60 wt% acetone, and 200- ppm TiO2 particles for flow visualization, and the surface tension was controlled by surfactant addition. Qualitatively, the experiments indicated that MV growth occurs in three distinct phases: (1) a very rapid initial growth period, (2) a much slower growth phase, and (3) absorption of selected MVs into the expanding demixed region. The presence of tracer particles inside the MVs suggests the presence of a convective flow, which transfers the particles from the bulk solution to the MV interior. Although the VMFV experiments did not establish any surfactant effect on the interfacial velocities, a statistically significant effect on the MV number density was observed. In the second set of experiments, membranes were cast aboard a KC-135 aircraft under 0-g and 2-g conditions. Despite careful attention to the design and fabrication of the membrane casting apparatus (MCA), several problems were encountered, the most significant of which was the contamination of the casting solution by the activated carbon particles used for solvent absorption.

P1088Match and mismatch between opening area and resistance in mild and moderate rheumatic mitral stenosis.

PubMed

El-Dosouky, I

2016-12-01

Mitral valve resistance (MVR) is a hemodynamic consequence of mitral stenosis but it has no clear threshold and it has a shortage of data to be reliable. is to investigate match and mismatch between opening area and resistance especially in patients with moderate and mild mitral stenosis. This cross section case control study comprised 88 patients with moderate and mild rheumatic mitral stenosis. Transthorathic echocardiographic study estimated: mitral valve area (MVA) both by planimerty (2D) and pressure half time (PHT), mitral valve score (MVS), mean transmitral pressure gradient (MPG), diastolic filling time(DFT), left ventricular out flow tract diameter (LVOTd) and velocity time integral (LVOT vti) , the MVR was calculated as: MPG/aortic flow ratio [(LVOTd) (LVOTvti)/ DFT] in dynes.sec.cm5, NYHA function class of all patients was estimated. We classified our patients into 2 groups, group 1 (51 patients) with matched MVR and group 2 (37 patients) with unmatched MVR (unexpected high MVR in relation to valve area). Patients with moderate mitral stenosis have MVR less than 105 dynes.sec/cm5, while patient with mild mitral stenosis have MVR less than 76 dynes.sec/cm5 this is in the matched group, but there are patients with unmatched higher MVR. Group 2 compared to group 1; had higher NYHA function class (1.4±0.6 vs. 1.2±0.4, P < 0.05), MVS (8.1±1.8 vs 7±0.9, P < 0.05), MPG (11,3±3.7 vs.7.8±2.5 mmHg, P < 0.01) and higher MVR (122.37±29.87 vs. 67.18±20.12 dynes.sec/cm5 , P < 0.01), MVR showed positive correlation with MVS (r=0.5, P < 0.05), Step wise logistic regression analysis showed that MVS is the only independent predictor of the MVR severity in the mismatched (unexpected high) group , so the higher the MVS the higher the expected MVR whatever the MVA is ; (B±SE=6.997±2.826, t=2.476, 95% CI 1.241±12.752 with an odds ratio=0.412, P < 0.05). It would make much more sense to investigate match and mismatch between opening area and resistance in rheumatic mitral stenosis, the only independent predictor of mismatch is the mitral valve score. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2016. For permissions please email: Journals.permissions@oup.com.

Novel High Speed Devices and Heterostructures Prepared by Molecular Beam Epitaxy

DTIC Science & Technology

1989-02-13

GaSb/GaAs system was reported from the results of photoreflectance measurements : w ereport a heavy-hole band offset s5; 1.7 for GaAs.g9bd.,, establishing...studied by variable temperature Hall measurements . For the GaA# 1_hb# material grown on InP, a two-acceptor model was forwarded to describe the Hall...Meanwhile, from Hall measurements , room temperature electron mobilities as high as 57000 m./Vs were reported in a 4.6 & thick unintentionally-doped InSb

Analyzing soil erosion using a multi-temporal UAV data set after one year of active agriculture in Navarra, Spain

NASA Astrophysics Data System (ADS)

Anders, Niels; Keesstra, Saskia; Masselink, Rens

2014-05-01

Unmanned Aerial System (UAS) are becoming popular tools in the geosciences due to improving technology and processing/analysis techniques. They can potentially fill the gap between spaceborne or manned aircraft remote sensing and terrestrial remote sensing, both in terms of spatial and temporal resolution. In this study we analyze a multi-temporal data set that was acquired with a fixed-wing UAS in an agricultural catchment (2 sq. km) in Navarra, Spain. The goal of this study is to register soil erosion activity after one year of agricultural activity. The aircraft was equipped with a Panasonic GX1 16MP pocket camera with a 20 mm lens to capture normal JPEG RGB images. The data set consisted of two sets of imagery acquired in the end of February in 2013 and 2014 after harvesting. The raw images were processed using Agisoft Photoscan Pro which includes the structure-from-motion (SfM) and multi-view stereopsis (MVS) algorithms producing digital surface models and orthophotos of both data sets. A discussion is presented that is focused on the suitability of multi-temporal UAS data and SfM/MVS processing for quantifying soil loss, mapping the distribution of eroded materials and analyzing re-occurrences of rill patterns after plowing.

ARC2D - EFFICIENT SOLUTION METHODS FOR THE NAVIER-STOKES EQUATIONS (DEC RISC ULTRIX VERSION)

NASA Technical Reports Server (NTRS)

Biyabani, S. R.

1994-01-01

ARC2D is a computational fluid dynamics program developed at the NASA Ames Research Center specifically for airfoil computations. The program uses implicit finite-difference techniques to solve two-dimensional Euler equations and thin layer Navier-Stokes equations. It is based on the Beam and Warming implicit approximate factorization algorithm in generalized coordinates. The methods are either time accurate or accelerated non-time accurate steady state schemes. The evolution of the solution through time is physically realistic; good solution accuracy is dependent on mesh spacing and boundary conditions. The mathematical development of ARC2D begins with the strong conservation law form of the two-dimensional Navier-Stokes equations in Cartesian coordinates, which admits shock capturing. The Navier-Stokes equations can be transformed from Cartesian coordinates to generalized curvilinear coordinates in a manner that permits one computational code to serve a wide variety of physical geometries and grid systems. ARC2D includes an algebraic mixing length model to approximate the effect of turbulence. In cases of high Reynolds number viscous flows, thin layer approximation can be applied. ARC2D allows for a variety of solutions to stability boundaries, such as those encountered in flows with shocks. The user has considerable flexibility in assigning geometry and developing grid patterns, as well as in assigning boundary conditions. However, the ARC2D model is most appropriate for attached and mildly separated boundary layers; no attempt is made to model wake regions and widely separated flows. The techniques have been successfully used for a variety of inviscid and viscous flowfield calculations. The Cray version of ARC2D is written in FORTRAN 77 for use on Cray series computers and requires approximately 5Mb memory. The program is fully vectorized. The tape includes variations for the COS and UNICOS operating systems. Also included is a sample routine for CONVEX computers to emulate Cray system time calls, which should be easy to modify for other machines as well. The standard distribution media for this version is a 9-track 1600 BPI ASCII Card Image format magnetic tape. The Cray version was developed in 1987. The IBM ES/3090 version is an IBM port of the Cray version. It is written in IBM VS FORTRAN and has the capability of executing in both vector and parallel modes on the MVS/XA operating system and in vector mode on the VM/XA operating system. Various options of the IBM VS FORTRAN compiler provide new features for the ES/3090 version, including 64-bit arithmetic and up to 2 GB of virtual addressability. The IBM ES/3090 version is available only as a 9-track, 1600 BPI IBM IEBCOPY format magnetic tape. The IBM ES/3090 version was developed in 1989. The DEC RISC ULTRIX version is a DEC port of the Cray version. It is written in FORTRAN 77 for RISC-based Digital Equipment platforms. The memory requirement is approximately 7Mb of main memory. It is available in UNIX tar format on TK50 tape cartridge. The port to DEC RISC ULTRIX was done in 1990. COS and UNICOS are trademarks and Cray is a registered trademark of Cray Research, Inc. IBM, ES/3090, VS FORTRAN, MVS/XA, and VM/XA are registered trademarks of International Business Machines. DEC and ULTRIX are registered trademarks of Digital Equipment Corporation.

ARC2D - EFFICIENT SOLUTION METHODS FOR THE NAVIER-STOKES EQUATIONS (CRAY VERSION)

NASA Technical Reports Server (NTRS)

Pulliam, T. H.

1994-01-01

ARC2D is a computational fluid dynamics program developed at the NASA Ames Research Center specifically for airfoil computations. The program uses implicit finite-difference techniques to solve two-dimensional Euler equations and thin layer Navier-Stokes equations. It is based on the Beam and Warming implicit approximate factorization algorithm in generalized coordinates. The methods are either time accurate or accelerated non-time accurate steady state schemes. The evolution of the solution through time is physically realistic; good solution accuracy is dependent on mesh spacing and boundary conditions. The mathematical development of ARC2D begins with the strong conservation law form of the two-dimensional Navier-Stokes equations in Cartesian coordinates, which admits shock capturing. The Navier-Stokes equations can be transformed from Cartesian coordinates to generalized curvilinear coordinates in a manner that permits one computational code to serve a wide variety of physical geometries and grid systems. ARC2D includes an algebraic mixing length model to approximate the effect of turbulence. In cases of high Reynolds number viscous flows, thin layer approximation can be applied. ARC2D allows for a variety of solutions to stability boundaries, such as those encountered in flows with shocks. The user has considerable flexibility in assigning geometry and developing grid patterns, as well as in assigning boundary conditions. However, the ARC2D model is most appropriate for attached and mildly separated boundary layers; no attempt is made to model wake regions and widely separated flows. The techniques have been successfully used for a variety of inviscid and viscous flowfield calculations. The Cray version of ARC2D is written in FORTRAN 77 for use on Cray series computers and requires approximately 5Mb memory. The program is fully vectorized. The tape includes variations for the COS and UNICOS operating systems. Also included is a sample routine for CONVEX computers to emulate Cray system time calls, which should be easy to modify for other machines as well. The standard distribution media for this version is a 9-track 1600 BPI ASCII Card Image format magnetic tape. The Cray version was developed in 1987. The IBM ES/3090 version is an IBM port of the Cray version. It is written in IBM VS FORTRAN and has the capability of executing in both vector and parallel modes on the MVS/XA operating system and in vector mode on the VM/XA operating system. Various options of the IBM VS FORTRAN compiler provide new features for the ES/3090 version, including 64-bit arithmetic and up to 2 GB of virtual addressability. The IBM ES/3090 version is available only as a 9-track, 1600 BPI IBM IEBCOPY format magnetic tape. The IBM ES/3090 version was developed in 1989. The DEC RISC ULTRIX version is a DEC port of the Cray version. It is written in FORTRAN 77 for RISC-based Digital Equipment platforms. The memory requirement is approximately 7Mb of main memory. It is available in UNIX tar format on TK50 tape cartridge. The port to DEC RISC ULTRIX was done in 1990. COS and UNICOS are trademarks and Cray is a registered trademark of Cray Research, Inc. IBM, ES/3090, VS FORTRAN, MVS/XA, and VM/XA are registered trademarks of International Business Machines. DEC and ULTRIX are registered trademarks of Digital Equipment Corporation.

Rheumatic mitral valve stenosis mimicking advanced lung cancer.

PubMed

von Lueder, Thomas; Steine, Kjetil; Nerdrum, Tone; Steen, Torkel; Bay, Dag; Humerfelt, Sjur; Atar, Dan

2007-09-01

This report describes a patient with a perihilar mass and mediastinal lymphadenopathy mimicking advanced lung cancer. The patient, a 45-year old regular smoker, was admitted to hospital for dyspnea and tachyarrhythmia, and during hospitalization he was diagnosed with severe rheumatic mitral valve stenosis (MVS) and aortic regurgitation as well as pulmonary venous hypertension. Surgical valve replacement and removal of an atrial thrombus was delayed considerably by diagnostic work-up for suspected malignancy. After cardiac surgery had been performed, recovery was uneventful. On follow-up 1 year later, echocardiography showed well-functioning prosthetic mitral and aortic valves, and normal findings on chest X-ray. Perihilar masses and mediastinal lymphadenopathy presented in this case constitute infrequent yet established findings in MVS, resulting from pulmonary venous congestion and hypertension, and focal lymphedema.

Organic Geochemistry of Sediments, Interstitial Fluids and Light Volatile Hydrocarbon Gases from Giza and North Alex Mud Volcanoes, Western Nile Deep-Sea Fan

NASA Astrophysics Data System (ADS)

Nuzzo, Marianne; Elvert, Marcus; Heuer, Verena; Schmidt, Mark; Hinrichs, Kai-Uwe; Scholz, Florian; Reitz, Anja; Hensen, Christian

2010-05-01

The West Nile Delta Project is a multi-disciplinary research project lead at IFM-GEOMAR (Kiel, Germany) and funded by RWE-DEA (Hamburg, Germany). It aims at investigating the sources and transport mechanisms of fluids and hydrocarbon gases seeping at two mud volcanoes (MVs) of the western Nile Deep-Sea Fan: North Alex and Giza MVs, and at the long-term monitoring of the seepage activity at these sites [1,2]. A comparative study of the organic geochemistry of sediments, gases and fluids was carried out in order to constrain (i) the sources of fluids, mud and gases erupted at these cold seeps, and (ii) the microbial hydrocarbon-oxidation processes associated with the extrusion of mud and gases. The molecular and stable isotope composition of light volatile hydrocarbon gases stripped from pore fluids reveal a clear thermogenic origin at the less active Giza MV and at the active centre of N. Alex MV. However, they probably originate from different sources, as shown by the distinct 13C-CH4 values of ~ -45‰ and -37‰VPDB at North Alex and Giza MVs, respectively, while 2H-CH4 values are similar (~ -228‰VSMOW). Away from the centre at North Alex MV the gases have variable compositions and are mainly produced by Archaea microbes. The microbial production of CH4 is probably sustained by the high content of the mud breccia sediments in labile organic matter. Indeed Total Organic Carbon content values are high (~ 1 and 2%weight) in MV sediments from both sites as well as at the reference site away from Giza MV, suggesting a main shallow (Plio-Pleistocene) sedimentary source. Consistently, the sedimentary lipids contain high amounts of compounds typically issued from terrestrial plants such as -amyrin and nC26:0 to nC30:0 fatty acids & alkenols. The hypothesis that labile terrestrial organic matter sustains intense microbial activity in the mud volcano sediments is supported by the extreme enrichment of pore fluids in a suite of Volatile Fatty Acids, in particular in acetic acid with values as high as 1 to 2mM at and near the centre of N. Alex MV. Additionally, the lipids extracted from MV sediments contain long-chain n-alkanes and biomarker compounds typically related to the presence of petroleum or bitumen as well as compounds associated with microbial communities living from the Anaerobic Oxidation of Methane. A large variety of these compounds have however been observed at the MVs, and their concentrations are quite variable as well. Here we present the results of multivariate statistical analyses applied to an extensive data set. Complementarily, Compound-Specific-Isotope-Analysis techniques have been used to study the origin of pore water Volatile Fatty Acids and of selected lipid biomarkers at Giza and North Alex MVs. Last, the information provided by geophysical imaging and heat flux measurements performed in the context of the West Nile Delta Project [1] has been taken into account to interpret the complex biogeochemical processes taking place at the MVs. [1] Feseker et al. (2008) RV Poseidon cruise report ISSN 1614-6298, IFM-GEOMAR, Kiel (Germany). [2] Bialas & Brϋckmann (2008) RV Pelagia 64PE298 WND Project cruise report, IFM-GEOMAR, Kiel (Germany), 52p.

Implementation of an advanced clinical and administrative hospital information system.

PubMed

Vegoda, P R; Dyro, J F

1986-01-01

Over the last six years since University Hospital opened, the University Hospital Information System (UHIS) has continued to evolve to what is today an advanced administrative and clinical information system. At University Hospital UHIS is the way of conducting business. A wide range of patient care applications are operational including Patient Registration, ADT for Inpatient/Outpatient/Emergency Room visits, Advanced Order Entry/Result Reporting, Medical Records, Lab Automated Data Acquisition/Quality Control, Pharmacy, Radiology, Dietary, Respiratory Therapy, ECG, EEG, Cardiology, Physical/Occupational Therapy and Nursing. These systems and numerous financial systems have been installed in a highly tuned, efficient computer system. All applications are real-time, on-line, and data base oriented. Each system is provided with multiple data security levels, forward file recovery, and dynamic transaction backout of in-flight tasks. Sensitive medical information is safeguarded by job function passwords, identification codes, need-to-know master screens and terminal keylocks. University Hospital has an IBM 3083 CPU with five 3380 disk drives, four dual density tape drives, and a 3705 network controller. The network of 300 terminals and 100 printers is connected to the computer center by an RF broadband cable. The software is configured around the IBM/MVS operating system using CICS as the telecommunication monitor, IMS as the data base management system and PCS/ADS as the application enabling tool. The most extensive clinical system added to UHIS is the Physiological Monitoring/Patient Data Management System with serves 92 critical care beds. In keeping with the Hospital's philosophy of integrated computing, the PMS/PDMS with its network of minicomputers was linked to the UHIS system. In a pilot program, remote access to UHIS through the IBM personal computer has been implemented in several physician offices in the local community, further extending the communications horizons of University Hospital's Information System. The implications of remote access to PDMS through the IBM PC emulating a Siemens Model 420 Patient Data Management Terminal are being examined.

Capacitive behavior of highly-oxidized graphite

NASA Astrophysics Data System (ADS)

Ciszewski, Mateusz; Mianowski, Andrzej

2014-09-01

Capacitive behavior of a highly-oxidized graphite is presented in this paper. The graphite oxide was synthesized using an oxidizing mixture of potassium chlorate and concentrated fuming nitric acid. As-oxidized graphite was quantitatively and qualitatively analyzed with respect to the oxygen content and the species of oxygen-containing groups. Electrochemical measurements were performed in a two-electrode symmetric cell using KOH electrolyte. It was shown that prolonged oxidation causes an increase in the oxygen content while the interlayer distance remains constant. Specific capacitance increased with oxygen content in the electrode as a result of pseudo-capacitive effects, from 0.47 to 0.54 F/g for a scan rate of 20 mV/s and 0.67 to 1.15 F/g for a scan rate of 5 mV/s. Better cyclability was observed for the electrode with a higher oxygen amount.

Semilocal density functional obeying a strongly tightened bound for exchange

PubMed Central

Sun, Jianwei; Perdew, John P.; Ruzsinszky, Adrienn

2015-01-01

Because of its useful accuracy and efficiency, density functional theory (DFT) is one of the most widely used electronic structure theories in physics, materials science, and chemistry. Only the exchange-correlation energy is unknown, and needs to be approximated in practice. Exact constraints provide useful information about this functional. The local spin-density approximation (LSDA) was the first constraint-based density functional. The Lieb–Oxford lower bound on the exchange-correlation energy for any density is another constraint that plays an important role in the development of generalized gradient approximations (GGAs) and meta-GGAs. Recently, a strongly and optimally tightened lower bound on the exchange energy was proved for one- and two-electron densities, and conjectured for all densities. In this article, we present a realistic “meta-GGA made very simple” (MGGA-MVS) for exchange that respects this optimal bound, which no previous beyond-LSDA approximation satisfies. This constraint might have been expected to worsen predicted thermochemical properties, but in fact they are improved over those of the Perdew–Burke–Ernzerhof GGA, which has nearly the same correlation part. MVS exchange is however radically different from that of other GGAs and meta-GGAs. Its exchange enhancement factor has a very strong dependence upon the orbital kinetic energy density, which permits accurate energies even with the drastically tightened bound. When this nonempirical MVS meta-GGA is hybridized with 25% of exact exchange, the resulting global hybrid gives excellent predictions for atomization energies, reaction barriers, and weak interactions of molecules. PMID:25561554

Hierarchically porous MnO2 microspheres doped with homogeneously distributed Fe3O4 nanoparticles for supercapacitors.

PubMed

Zhu, Jian; Tang, Shaochun; Xie, Hao; Dai, Yuming; Meng, Xiangkang

2014-10-22

Hierarchically porous yet densely packed MnO2 microspheres doped with Fe3O4 nanoparticles are synthesized via a one-step and low-cost ultrasound assisted method. The scalable synthesis is based on Fe(2+) and ultrasound assisted nucleation and growth at a constant temperature in a range of 25-70 °C. Single-crystalline Fe3O4 particles of 3-5 nm in diameter are homogeneously distributed throughout the spheres and none are on the surface. A systematic optimization of reaction parameters results in isolated, porous, and uniform Fe3O4-MnO2 composite spheres. The spheres' average diameter is dependent on the temperature, and thus is controllable in a range of 0.7-1.28 μm. The involved growth mechanism is discussed. The specific capacitance is optimized at an Fe/Mn atomic ratio of r = 0.075 to be 448 F/g at a scan rate of 5 mV/s, which is nearly 1.5 times that of the extremely high reported value for MnO2 nanostructures (309 F/g). Especially, such a structure allows significantly improved stability at high charging rates. The composite has a capacitance of 367.4 F/g at a high scan rate of 100 mV/s, which is 82% of that at 5 mV/s. Also, it has an excellent cycling performance with a capacitance retention of 76% after 5000 charge/discharge cycles at 5 A/g.

Semilocal density functional obeying a strongly tightened bound for exchange.

PubMed

Sun, Jianwei; Perdew, John P; Ruzsinszky, Adrienn

2015-01-20

Because of its useful accuracy and efficiency, density functional theory (DFT) is one of the most widely used electronic structure theories in physics, materials science, and chemistry. Only the exchange-correlation energy is unknown, and needs to be approximated in practice. Exact constraints provide useful information about this functional. The local spin-density approximation (LSDA) was the first constraint-based density functional. The Lieb-Oxford lower bound on the exchange-correlation energy for any density is another constraint that plays an important role in the development of generalized gradient approximations (GGAs) and meta-GGAs. Recently, a strongly and optimally tightened lower bound on the exchange energy was proved for one- and two-electron densities, and conjectured for all densities. In this article, we present a realistic "meta-GGA made very simple" (MGGA-MVS) for exchange that respects this optimal bound, which no previous beyond-LSDA approximation satisfies. This constraint might have been expected to worsen predicted thermochemical properties, but in fact they are improved over those of the Perdew-Burke-Ernzerhof GGA, which has nearly the same correlation part. MVS exchange is however radically different from that of other GGAs and meta-GGAs. Its exchange enhancement factor has a very strong dependence upon the orbital kinetic energy density, which permits accurate energies even with the drastically tightened bound. When this nonempirical MVS meta-GGA is hybridized with 25% of exact exchange, the resulting global hybrid gives excellent predictions for atomization energies, reaction barriers, and weak interactions of molecules.

Mesenteric lymph node stromal cell‐derived extracellular vesicles contribute to peripheral de novo induction of Foxp3+ regulatory T cells

PubMed Central

Pasztoi, Maria; Pezoldt, Joern; Beckstette, Michael; Lipps, Christoph; Wirth, Dagmar; Rohde, Manfred; Paloczi, Krisztina; Buzas, Edit Iren

2017-01-01

Abstract Intestinal regulatory T cells (Tregs) are fundamental in peripheral tolerance toward commensals and food‐borne antigens. Accordingly, gut‐draining mesenteric lymph nodes (mLNs) represent a site of efficient peripheral de novo Treg induction when compared to skin‐draining peripheral LNs (pLNs), and we had recently shown that LN stromal cells substantially contribute to this process. Here, we aimed to unravel the underlying molecular mechanisms and generated immortalized fibroblastic reticular cell lines (iFRCs) from mLNs and pLNs, allowing unlimited investigation of this rare stromal cell subset. In line with our previous findings, mLN‐iFRCs showed a higher Treg‐inducing capacity when compared to pLN‐iFRCs. RNA‐seq analysis focusing on secreted molecules revealed a more tolerogenic phenotype of mLN‐ as compared to pLN‐iFRCs. Remarkably, mLN‐iFRCs produced substantial numbers of microvesicles (MVs) that carried elevated levels of TGF‐β when compared to pLN‐iFRC‐derived MVs, and these novel players of intercellular communication were shown to be responsible for the tolerogenic properties of mLN‐iFRCs. Thus, stromal cells originating from mLNs contribute to peripheral tolerance by fostering de novo Treg induction using TGF‐β‐carrying MVs. This finding provides novel insights into the subcellular/molecular mechanisms of de novo Treg induction and might serve as promising tool for future therapeutic applications to treat inflammatory disorders. PMID:28833065

Membrane-shed vesicles from the parasite Trichomonas vaginalis: characterization and their association with cell interaction.

PubMed

Nievas, Yesica R; Coceres, Veronica M; Midlej, Victor; de Souza, Wanderley; Benchimol, Marlene; Pereira-Neves, Antonio; Vashisht, Ajay A; Wohlschlegel, James A; Johnson, Patricia J; de Miguel, Natalia

2018-06-01

Trichomonas vaginalis is a common sexually transmitted parasite that colonizes the human urogenital tract, where it remains extracellular and adheres to epithelial cells. Infections range from asymptomatic to highly inflammatory, depending on the host and the parasite strain. Despite the serious consequences associated with trichomoniasis disease, little is known about parasite or host factors involved in attachment of the parasite-to-host epithelial cells. Here, we report the identification of microvesicle-like structures (MVs) released by T. vaginalis. MVs are considered universal transport vehicles for intercellular communication as they can incorporate peptides, proteins, lipids, miRNA, and mRNA, all of which can be transferred to target cells through receptor-ligand interactions, fusion with the cell membrane, and delivery of a functional cargo to the cytoplasm of the target cell. In the present study, we demonstrated that T. vaginalis release MVs from the plasma and the flagellar membranes of the parasite. We performed proteomic profiling of these structures demonstrating that they possess physical characteristics similar to mammalian extracellular vesicles and might be selectively charged with specific protein content. In addition, we demonstrated that viable T. vaginalis parasites release large vesicles (LVs), membrane structures larger than 1 µm that are able to interact with other parasites and with the host cell. Finally, we show that both populations of vesicles present on the surface of T vaginalis are induced in the presence of host cells, consistent with a role in modulating cell interactions.

Experimental demonstration of plasma startup by coaxial helicity injection

NASA Astrophysics Data System (ADS)

Raman, R.; Jarboe, T. R.; Nelson, B. A.; Hamp, W. T.; Izzo, V. A.; O'Neill, R. G.; Redd, A. J.; Sieck, P. E.; Smith, R. J.

2004-05-01

Experimental results on the transfer of a coaxial-helicity-injection (CHI) produced discharge to inductive operation are reported. CHI assisted plasma startup is more robust than inductive only operation and reduces volt-seconds consumption. After handoff to inductive operation, the initial 100 kA of CHI produced current drops to 50 kA, then ramps up to 180 kA, using only 30 mVs, about 40% higher than that produced by induction alone. Results show that initiation of CHI discharges at lower densities produce higher levels of coupling current. Coupling a CHI produced discharge to induction from a precharged central solenoid has produced record currents of 290 kA using only 52 mWb of central solenoid flux. CHI discharges can also be generated while the central transformer is in the process of being precharged, during which period it induces a negative loop voltage on the CHI discharge. These significant results were obtained on the Helicity Injected Torus-II (HIT-II) [T.R. Jarboe, Fusion Technol. 15, 7 (1989)] spherical torus experiment (major/minor radius of 0.3/0.2 m and elongation of 1.5).

Theory of planned behavior and multivitamin supplement use in Caucasian college females.

PubMed

Pawlak, Roman; Brown, Denise; Meyer, Mary Kay; Connell, Carol; Yadrick, Kathleen; Johnson, J T; Blackwell, Ann

2008-01-01

The objective of this study was to identify predictors of the use of multivitamin supplements (MVS) among Caucasian college females utilizing the Theory of Planned Behavior (TPB). Variables of the TPB and the self-reported use of multivitamin supplements were measured by two separate surveys within 1 week with a convenience sample of 96 Caucasian college student females. Two attitudinal beliefs and one control belief significantly predicted behavioral intention to use multivitamin. A belief that taking multivitamin supplements helps to feel and look good was the most important predictor of the use of multivitamin supplements. EDITORS' STRATEGIC IMPLICATIONS: Findings from this study, although in need of replication, suggest that prevention campaigns would be more successful if messages used to reach these females were consistent with perceived beliefs regarding benefits of using MVS. More broadly, TPB appears to offer a useful framework for understanding or predicting behavior based on psychological constructs theorized to influence behavior.

Integrated studies for automobile wastes management in developing countries; in the concept of environmentally friendly mechanic village.

PubMed

Nwachukwu, Michael Amamechi; Feng, Huan; Achilike, Kennedy

2011-07-01

More cities in developing countries now consider mechanic village (MV) as superior to the city wide auto-workshop practice following the increasing influx of used or waste automobile from industrialized nations. This is because of the numerous advantages of the mechanic village concept as a capacity building, and in poverty alleviation. Nevertheless, mechanic villages are poorly developed with no waste management plan. They are now identified with severe to excessive heavy metal soil pollution, causing ecological and public health hazards. This paper has a wider explanation of what it takes for a mechanic village to be environmentally friendly based on spectroscopic analysis and physical measurements conducted in three MVs. Heavy metal concentrations (mg kg( -1)) above background levels in the upper 100 cm soil profiles of the Okigwe, the Orji, and the Nekede MVs in the Imo River basin collectively range 748-70,606 for Fe; 99-1,090 for Pb; 186-600 for Mn; 102-1,001 for Cu; 8-23 for Cd; 4-27 for Cr; and 3-10 for Ni. The most abundant metals of environmental concerns are Pb, Mn, and Cu, in the order of Pb > Mn > Cu. Three-phase storm water treatment, emission testing, minimum safe farming distance (350 m), extended producer responsibility for disposal or recycling of used motor oil, phyto-remediation using local plants, groundwater monitoring wells, and continuous education of mechanics are recommended. Exporters of waste automobiles to developing countries and the United Nations may assist developing countries in establishing environmentally friendly MVs.

Ground-based structure from motion - multi view stereo (SFM-MVS) for upland soil erosion assessment.

NASA Astrophysics Data System (ADS)

McShane, Gareth; James, Mike; Quniton, John; Farrow, Luke; Glendell, Miriam; Jones, Lee; Kirkham, Matthew; Morgan, David; Evans, Martin; Anderson, Karen; Lark, Murray; Rawlins, Barry; Rickson, Jane; Quine, Timothy; Benaud, Pia; Brazier, Richard

2016-04-01

In upland environments, quantifying soil loss through erosion processes at a high resolution can be time consuming, costly and logistically difficult. In this pilot study 'A cost effective framework for monitoring soil erosion in England and Wales', funded by the UK Department for Environment, Food and Rural Affairs (Defra), we evaluate the use of annually repeated ground-based photography surveys, processed using structure-from-motion and multi-view stereo (SfM-MVS) 3-D reconstruction software (Agisoft Photoscan). The aim is to enable efficient but detailed site-scale studies of erosion forms in inaccessible UK upland environments, in order to quantify dynamic processes, such as erosion and mass movement. The evaluation of the SfM-MVS technique is particularly relevant in upland landscapes, where the remoteness and inaccessibility of field sites may render some of the more established survey techniques impractical. We present results from 5 upland sites across the UK, acquired over a 2-year period. Erosion features of varying width (3 m to 35 m) and length (20 m to 60 m), representing a range of spatial scales (from 100 m2 to 1000 m2) were surveyed, in upland habitats including bogs, peatland, upland grassland and moorland. For each feature, around 150 to 600 ground-based photographs were taken at oblique angles over a 10 to 20 minute period, using an uncalibrated Canon 600D SLR camera with a 28 mm lens (focal length set to infinity). Camera settings varied based upon light conditions (exposure 100-400 ISO, aperture F4.5 to F8, shutter speed 1/100 to 1/250 second). For inter-survey comparisons, models were geo-referenced using 20 to 30 ground control points (numbered black markers with a white target) placed around and within the feature, with their co-ordinates measured by survey-grade differential GNSS (Trimble R4). Volumetric estimates of soil loss were quantified using digital surface models (DSMs) derived from the repeat survey data and subtracted from a modelled pre-erosion surface (CloudCompare, Golden Software Surfer). We discuss the survey performance achieved in terms of the time required and the precisions delivered, and consider the practical application of SfM-MVS for long-term upland erosion monitoring.

Multi-objective optimization for model predictive control.

PubMed

Wojsznis, Willy; Mehta, Ashish; Wojsznis, Peter; Thiele, Dirk; Blevins, Terry

2007-06-01

This paper presents a technique of multi-objective optimization for Model Predictive Control (MPC) where the optimization has three levels of the objective function, in order of priority: handling constraints, maximizing economics, and maintaining control. The greatest weights are assigned dynamically to control or constraint variables that are predicted to be out of their limits. The weights assigned for economics have to out-weigh those assigned for control objectives. Control variables (CV) can be controlled at fixed targets or within one- or two-sided ranges around the targets. Manipulated Variables (MV) can have assigned targets too, which may be predefined values or current actual values. This MV functionality is extremely useful when economic objectives are not defined for some or all the MVs. To achieve this complex operation, handle process outputs predicted to go out of limits, and have a guaranteed solution for any condition, the technique makes use of the priority structure, penalties on slack variables, and redefinition of the constraint and control model. An engineering implementation of this approach is shown in the MPC embedded in an industrial control system. The optimization and control of a distillation column, the standard Shell heavy oil fractionator (HOF) problem, is adequately achieved with this MPC.

Estimating rates of coastal cliff erosion in a small island using terrestrial laser scanning and RPAS-based SfM-MVS photogrammetry

NASA Astrophysics Data System (ADS)

Hayakawa, Yuichi S.; Obanawa, Hiroyuki

2017-04-01

Rapid erosion of coastal cliffs has been historically observed to be more than 1 m/y in the outer Boso Peninsula area, eastern Japan. However, due to the modern work of coastal protection, the erosion rates of the coastal cliffs have significantly decreased. This caused coastal erosion in the nearby sand beach, to which sands had been supplied from the formerly eroded rocky coast. In order to assess the relationships between erosion and protection in both rocky and sandy coasts, quantitative evaluation of erosion rates by natural processes would be necessary. The Suzume-jima Island, a small coastal island in the outer Boso Peninsula area, is an ideal site, which is located outside of the coastal protection and natural processes of erosion can still be observed. Here we carried out multiple measurements of the entire shape of the island using remotely piloted aerial system (RPAS) and structure-from-motion multi-view stereo (SfM-MVS) photogrammetry. Terrestrial laser scanning is also performed for the accuracy assessment. The high-frequency (3 times a year) and high-resolution (cm) measurements of the small island for 3 years revealed spatially variable rockfalls and wave erosion, whose volume of mass has been quantitatively revealed from the 3-D point cloud obtained. The relatively short-term measurements are also compared with the long-term 2-D topographic changes in the island by aerial photographs for 50 years.

Dynamic, nonlinear feedback regulation of slow pacemaking by A-type potassium current in ventral tegmental area neurons.

PubMed

Khaliq, Zayd M; Bean, Bruce P

2008-10-22

We analyzed ionic currents that regulate pacemaking in dopaminergic neurons of the mouse ventral tegmental area by comparing voltage trajectories during spontaneous firing with ramp-evoked currents in voltage clamp. Most recordings were made in brain slice, with key experiments repeated using acutely dissociated neurons, which gave identical results. During spontaneous firing, net ionic current flowing between spikes was calculated from the time derivative of voltage multiplied by cell capacitance, signal-averaged over many firing cycles to enhance resolution. Net inward interspike current had a distinctive nonmonotonic shape, reaching a minimum (generally <1 pA) between -60 and -55 mV. Under voltage clamp, ramps over subthreshold voltages elicited a time- and voltage-dependent outward current that peaked near -55 mV. This current was undetectable with 5 mV/s ramps and increased steeply with depolarization rate over the range (10-50 mV/s) typical of natural pacemaking. Ramp-evoked subthreshold current was resistant to alpha-dendrotoxin, paxilline, apamin, and tetraethylammonium but sensitive to 4-aminopyridine and 0.5 mM Ba2+, consistent with A-type potassium current (I(A)). Same-cell comparison of currents elicited by various ramp speeds with natural spontaneous depolarization showed how the steep dependence of I(A) on depolarization rate results in small net inward currents during pacemaking. These results reveal a mechanism in which subthreshold I(A) is near zero at steady state, but is engaged at depolarization rates >10 mV/s to act as a powerful, supralinear feedback element. This feedback mechanism explains how net ionic current can be constrained to <1-2 pA but reliably inward, thus enabling slow, regular firing.

Analysis of Industry Responses to Federal Regulations in Safety Requirements for New Automobiles

DOT National Transportation Integrated Search

1978-03-01

This report presents findings of an initial study of how the automobile industry has responded to the promulgation of motor vehicle standards by the U.S. goverment. The report examines three safety standards as evaluative cases: MVS 203--Steering col...

Assessment of tools for modeling aircraft noise in national parks

DOT National Transportation Integrated Search

2005-03-18

The first objective of this study was to evaluate the series of model enhancements that were included in : INM as a result of the recommendations from the GCNP MVS. Specifically, there was a desire to : evaluate the performance of the latest versions...

Electrochemical studies of biocatalytic anode of sulfonated graphene/ferritin/glucose oxidase layer-by-layer biocomposite films for mediated electron transfer.

PubMed

Inamuddin; Haque, Sufia Ul; Naushad, Mu

2016-06-01

In this study, a bioanode was developed by using layer-by-layer (LBL) assembly of sulfonated graphene (SG)/ferritin (Frt)/glucose oxidase (GOx). The SG/Frt biocomposite was used as an electron transfer elevator and mediator, respectively. Glucose oxidase (GOx) from Aspergillus niger was applied as a glucose oxidation biocatalyst. The electrocatalytic oxidation of glucose using GOx modified electrode increases with an increase in the concentration of glucose in the range of 10-50mM. The electrochemical measurements of the electrode was carried out by using cyclic voltammetry (CV) at different scan rates (20-100mVs(-1)) in 30mM of glucose solution prepared in 0.3M potassium ferrocyanide (K4Fe(CN)6) and linear sweep voltammetry (LSV). A saturation current density of 50±2mAcm(-2) at a scan rate of 100mVs(-1) for the oxidation of 30Mm glucose is achieved. Copyright © 2016 Elsevier Inc. All rights reserved.

The Effect of Underwater Imagery Radiometry on 3d Reconstruction and Orthoimagery

NASA Astrophysics Data System (ADS)

Agrafiotis, P.; Drakonakis, G. I.; Georgopoulos, A.; Skarlatos, D.

2017-02-01

The work presented in this paper investigates the effect of the radiometry of the underwater imagery on automating the 3D reconstruction and the produced orthoimagery. Main aim is to investigate whether pre-processing of the underwater imagery improves the 3D reconstruction using automated SfM - MVS software or not. Since the processing of images either separately or in batch is a time-consuming procedure, it is critical to determine the necessity of implementing colour correction and enhancement before the SfM - MVS procedure or directly to the final orthoimage when the orthoimagery is the deliverable. Two different test sites were used to capture imagery ensuring different environmental conditions, depth and complexity. Three different image correction methods are applied: A very simple automated method using Adobe Photoshop, a developed colour correction algorithm using the CLAHE (Zuiderveld, 1994) method and an implementation of the algorithm described in Bianco et al., (2015). The produced point clouds using the initial and the corrected imagery are then being compared and evaluated.

Hierarchical and Multifunctional Three-dimensional Network of Carbon Nanotubes for Supercapacitor and Strain Sensor Applications

DTIC Science & Technology

2016-05-19

cycles at 100 mV/s scan rate. 15. SUBJECT TERMS Carbon nano tubes, Nanotechnology , supercapacitor 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF...5. Lee, H., Hierarchical and Multifunctional Three-dimensional Network of Carbon Nanotubes of Sensor Applications, College of Engineering Forum on

Role of Interaction in Enhancing the Epistemic Utility of 3D Mathematical Visualizations

ERIC Educational Resources Information Center

Liang, Hai-Ning; Sedig, Kamran

2010-01-01

Many epistemic activities, such as spatial reasoning, sense-making, problem solving, and learning, are information-based. In the context of epistemic activities involving mathematical information, learners often use interactive 3D mathematical visualizations (MVs). However, performing such activities is not always easy. Although it is generally…

Role of Microvesicles in the Spread of Herpes Simplex Virus 1 in Oligodendrocytic Cells.

PubMed

Bello-Morales, Raquel; Praena, Beatriz; de la Nuez, Carmen; Rejas, María Teresa; Guerra, Milagros; Galán-Ganga, Marcos; Izquierdo, Manuel; Calvo, Víctor; Krummenacher, Claude; López-Guerrero, José Antonio

2018-05-15

Herpes simplex virus 1 (HSV-1) is a neurotropic pathogen that can infect many types of cells and establishes latent infections in the neurons of sensory ganglia. In some cases, the virus spreads into the central nervous system, causing encephalitis or meningitis. Cells infected with several different types of viruses may secrete microvesicles (MVs) containing viral proteins and RNAs. In some instances, extracellular microvesicles harboring infectious virus have been found. Here we describe the features of shedding microvesicles released by the human oligodendroglial HOG cell line infected with HSV-1 and their participation in the viral cycle. Using transmission electron microscopy, we detected for the first time microvesicles containing HSV-1 virions. Interestingly, the Chinese hamster ovary (CHO) cell line, which is resistant to infection by free HSV-1 virions, was susceptible to HSV-1 infection after being exposed to virus-containing microvesicles. Therefore, our results indicate for the first time that MVs released by infected cells contain virions, are endocytosed by naive cells, and lead to a productive infection. Furthermore, infection of CHO cells was not completely neutralized when virus-containing microvesicles were preincubated with neutralizing anti-HSV-1 antibodies. The lack of complete neutralization and the ability of MVs to infect nectin-1/HVEM-negative CHO-K1 cells suggest a novel way for HSV-1 to spread to and enter target cells. Taken together, our results suggest that HSV-1 could spread through microvesicles to expand its tropism and that microvesicles could shield the virus from neutralizing antibodies as a possible mechanism to escape the host immune response. IMPORTANCE Herpes simplex virus 1 (HSV-1) is a neurotropic pathogen that can infect many types of cells and establishes latent infections in neurons. Extracellular vesicles are a heterogeneous group of membrane vesicles secreted by most cell types. Microvesicles, which are extracellular vesicles which derive from the shedding of the plasma membrane, isolated from the supernatant of HSV-1-infected HOG cells were analyzed to find out whether they were involved in the viral cycle. The importance of our investigation lies in the detection, for the first time, of microvesicles containing HSV-1 virions. In addition, virus-containing microvesicles were endocytosed into CHO-K1 cells and were able to actively infect these otherwise nonpermissive cells. Finally, the infection of CHO cells with these virus-containing microvesicles was not completely neutralized by anti-HSV-1 antibodies, suggesting that these extracellular vesicles might shield the virus from neutralizing antibodies as a possible mechanism of immune evasion. Copyright © 2018 Bello-Morales et al.

Searching for Better Photorefractive Materials

DTIC Science & Technology

2005-07-13

tetrabutylammonium hexafluorophosphate (0.1 M in methylene chloride). The scan rate was adjusted to 25 mV/s. All potentials were calibrated with a...Synthesis of MO. Thiophene (5.25g, 62.5mmol) was refluxed in 20ml hexane with TMEDA (21.77g, 187.4mmol), followed by dropwise adding n-butyl lithium

40 CFR Appendix A to Subpart II of... - VOC Data Sheet 1

Code of Federal Regulations, 2014 CFR

2014-07-01

... (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES (CONTINUED) National Emission Standards for Shipbuilding and Ship Repair (Surface Coating) Pt. 63, Subpt. II, App. A...: (Dc)s __ g/L [] ASTM D1475-90 *[] Other 3 B. Total Volatiles: (mv)s __ Mass Percent [] ASTM D2369-93...

Nitrogen-Doped Banana Peel–Derived Porous Carbon Foam as Binder-Free Electrode for Supercapacitors

PubMed Central

Liu, Bingzhi; Zhang, Lili; Qi, Peirong; Zhu, Mingyuan; Wang, Gang; Ma, Yanqing; Guo, Xuhong; Chen, Hui; Zhang, Boya; Zhao, Zhuangzhi; Dai, Bin; Yu, Feng

2016-01-01

Nitrogen-doped banana peel–derived porous carbon foam (N-BPPCF) successfully prepared from banana peels is used as a binder-free electrode for supercapacitors. The N-BPPCF exhibits superior performance including high specific surface areas of 1357.6 m2/g, large pore volume of 0.77 cm3/g, suitable mesopore size distributions around 3.9 nm, and super hydrophilicity with nitrogen-containing functional groups. It can easily be brought into contact with an electrolyte to facilitate electron and ion diffusion. A comparative analysis on the electrochemical properties of BPPCF electrodes is also conducted under similar conditions. The N-BPPCF electrode offers high specific capacitance of 185.8 F/g at 5 mV/s and 210.6 F/g at 0.5 A/g in 6 M KOH aqueous electrolyte versus 125.5 F/g at 5 mV/s and 173.1 F/g at 0.5 A/g for the BPPCF electrode. The results indicate that the N-BPPCF is a binder-free electrode that can be used for high performance supercapacitors. PMID:28344275

Nitrogen-Doped Banana Peel-Derived Porous Carbon Foam as Binder-Free Electrode for Supercapacitors.

PubMed

Liu, Bingzhi; Zhang, Lili; Qi, Peirong; Zhu, Mingyuan; Wang, Gang; Ma, Yanqing; Guo, Xuhong; Chen, Hui; Zhang, Boya; Zhao, Zhuangzhi; Dai, Bin; Yu, Feng

2016-01-15

Nitrogen-doped banana peel-derived porous carbon foam (N-BPPCF) successfully prepared from banana peels is used as a binder-free electrode for supercapacitors. The N-BPPCF exhibits superior performance including high specific surface areas of 1357.6 m²/g, large pore volume of 0.77 cm³/g, suitable mesopore size distributions around 3.9 nm, and super hydrophilicity with nitrogen-containing functional groups. It can easily be brought into contact with an electrolyte to facilitate electron and ion diffusion. A comparative analysis on the electrochemical properties of BPPCF electrodes is also conducted under similar conditions. The N-BPPCF electrode offers high specific capacitance of 185.8 F/g at 5 mV/s and 210.6 F/g at 0.5 A/g in 6 M KOH aqueous electrolyte versus 125.5 F/g at 5 mV/s and 173.1 F/g at 0.5 A/g for the BPPCF electrode. The results indicate that the N-BPPCF is a binder-free electrode that can be used for high performance supercapacitors.

Immobilization of nanobeads on a surface to control the size, shape and distribution of pores in electrochemically generated sol-gel films.

PubMed

Ciabocco, Michela; Berrettoni, Mario; Zamponi, Silvia; Cox, James A

2015-07-01

Electrochemically assisted deposition of an ormosil film at a potential where hydrogen ion is generated as the catalyst yields insulating films on electrodes. When the base electrode is modified with 20-nm poly(styrene sulfonate), PSS, beads bound to the surface with 3-aminopropyltriethoxysilane (APTES) and using (CH 3 ) 3 SiOCH 3 as the precursor, the resulting film of organically modified silica (ormosil) has cylindrical channels that reflect both the diameter of the PSS and the distribution of the APTES-PSS on the electrode. At an electrode modified by a 20-min immersion in 0.5 mmol dm -3 APTES followed by a 30-s immersion in PSS, a 20-min electrolysis at 1.5 V in acidified (CH 3 ) 3 SiOCH 3 resulted in an ormosil film with 20-nm pores separated by 100 nm. Cyclic voltammetry of Ru(CN) 6 4- at scan rates above 5 mVs -1 yielded currents controlled primarily by linear diffusion. Below 5 mVs -1 , convection rather than the expected factor, radial diffusion, apparently limited the current.

Explaining reduction of pedestrian-motor vehicle crashes in Arkhangelsk, Russia, in 2005-2010.

PubMed

Kudryavtsev, Alexander V; Nilssen, Odd; Lund, Johan; Grjibovski, Andrej M; Ytterstad, Børge

2012-01-01

To explain a reduction in pedestrian-motor vehicle crashes in Arkhangelsk, Russia, in 2005-2010. Retrospective ecological study. For 2005-2010, police data on pedestrian-motor vehicle crashes, traffic violations, and total motor vehicles (MVs) were combined with data on changes in national road traffic legislation and municipal road infrastructure. Negative binomial regression was used to investigate trends in monthly rates of pedestrian-motor vehicle crashes per total MVs and estimate changes in these rates per unit changes in the safety measures. During the 6 years, the police registered 2,565 pedestrian-motor vehicle crashes: 1,597 (62%) outside crosswalks, 766 (30%) on non-signalized crosswalks, and 202 (8%) on signalized crosswalks. Crash rates outside crosswalks and on signalized crosswalks decreased on average by 1.1% per month, whereas the crash rate on non-signalized crosswalks remained unchanged. Numbers of signalized and non-signalized crosswalks increased by 14 and 19%, respectively. Also, 10% of non-signalized crosswalks were combined with speed humps, and 4% with light-reflecting vertical signs. Pedestrian penalties for traffic violations increased 4-fold. Driver penalties for ignoring prohibiting signal and failure to give way to pedestrian on non-signalized crosswalk increased 7- and 8-fold, respectively. The rate of total registered drivers' traffic violations per total MVs decreased on average by 0.3% per month. All studied infrastructure and legislative measures had inverse associations with the rate of crashes outside crosswalks. The rate of crashes on signalized crosswalks showed inverse associations with related monetary penalties. The introduction of infrastructure and legislative measures is the most probable explanation of the reduction of pedestrian-motor vehicle crashes in Arkhangelsk. The overall reduction is due to decreases in rates of crashes outside crosswalks and on signalized crosswalks. No change was observed in the rate of crashes on non-signalized crosswalks.

Adding Biotin to Parenteral Nutrition Solutions Without Lipid Accelerates the Growth of Candida albicans.

PubMed

Kuwahara, Takashi; Kaneda, Shinya; Shimono, Kazuyuki

2016-01-01

We have previously demonstrated that Candida albicans requires multivitamins (MVs) or lipid to increase rapidly in parenteral nutrition (PN) solutions. In this study, in detail, the effects of vitamins on the growth of C. albicans in PN solutions without lipid were investigated. In the 1st experiment, a commercial PN solution without lipid was supplemented with water-soluble vitamins (SVs: vitamins B1, B2, B6, B12 and C, folic acid, nicotinamide, biotin and panthenol), water-insoluble vitamins (IVs: vitamins A, D, E and K) or both (MVs). In the 2nd experiment, the test solutions were prepared by supplementing the PN solution with one of each or all of the SVs. In the 3rd experiment, another commercial peripheral PN (PPN) solution without lipid was supplemented with SVs, nicotinic acid, biotin or both nicotinic acid and biotin. In each of the experiments, a specified number of C. albicans organisms was added to each test solution, and all of the test solutions were allowed to stand at room temperature (23-26ºC). The number of C. albicans was counted at 0, 24, 48 and 72 hours after the addition of the organism. In the 1st experiment, the C. albicans increased rapidly in the PN solution supplemented with the SVs, but increased slowly without the SVs, regardless of the addition of the IVs. In the 2nd experiment, the C. albicans increased rapidly in the PN solution supplemented with the SVs or biotin, but increased slowly with each of the other water-soluble vitamins. In the 3rd experiment, the C. albicans increased rapidly in the PPN solution supplemented with the SVs or biotin, but increased slowly with the addition of nicotinic acid. These results suggested that adding MVs or SVs to PN solutions without lipid promotes the growth of C. albicans, and that this effect is mostly attributable to biotin.

Vocational Interests and Needs of Unemployed, Low-Education Adults with Severe Substance Abuse Problems in Anchorage, Alaska

ERIC Educational Resources Information Center

Johnson, Mark E.; Reynolds, Grace; Fisher, Dennis G.; Harbke, Colin R.

2011-01-01

Vocational assessment data were collected from 94 low-education adults with severe substance abuse problems not currently in treatment. Participants completed the My Vocational Situation (MVS), Self-Directed Search (SDS), and Reading-Free Vocational Interest Inventory (R-FVII). Lower scores than the normative sample were revealed on all MVS…

Layer Structured Bismuth Selenides of Bi₂Se₃ and Bi₃Se₄ for High Energy and Flexible All-Solid-State Micro-Supercapacitors.

PubMed

Hao, Chunxue; Wang, Lidan; Wen, Fusheng; Xiang, Jianyong; Li, Lei; Hu, Wentao; Liu, Zhongyuan

2017-12-20

Bismuth selenides (Bi2Se3 and Bi3Se4), both of which have the layered rhombohedral crystal structure, and found to be useful as electrode materials for supercapacitor application in this work. Bi2Se3 nanoplates as electrode material exhibit much better performance than that of Bi3Se4 nanoparticles in liquid electrolyte system (6 M KOH), which delivers a higher specific capacitance (272.9 F/g) than that of Bi3Se4 (193.6 F/g) at 5 mV/s. This result would may be attributed to that Bi2Se3 nanoplates possess more active electrochemical surfaces for the reversible surface redox reactions owing to its planar quintuple stacked layers (septuple layers for Bi3Se4). For the demand of electronic skin, we used a novel flexible annular interdigital structure electrode applying for all-solid-state micro-supercapacitors (AMSCs). Bi2Se3 AMSCs device delivers a much more excellent supercapacitor performance, exhibits a large stack capacitance 89.5 F/cm3 (Bi3Se4: 79.1 F/cm3) at 20 mV/s, a high energy density 17.9 mWh/cm3 and high power density 18.9 W/cm3. The bismuth selenides also exhibit good cycle stability, retention 95.5% (90.3%) after 1000 c for Bi2Se3 (Bi3Se4). Obviously, Bi2Se3 nanoplates can be promising electrode materials for flexible annular interdigital all-solid-sate supercapacitor. © 2017 IOP Publishing Ltd.

Landslides triggered by an earthquake and heavy rainfalls at Aso volcano, Japan, detected by UAS and SfM-MVS photogrammetry

NASA Astrophysics Data System (ADS)

Saito, Hitoshi; Uchiyama, Shoichiro; Hayakawa, Yuichi S.; Obanawa, Hiroyuki

2018-12-01

Unmanned aerial systems (UASs) and structure-from-motion multi-view stereo (SfM-MVS) photogrammetry have attracted a tremendous amount of interest for use in the creation of high-definition topographic data for geoscientific studies. By using these techniques, this study examined the topographic characteristics of coseismic landslides triggered by the 2016 Kumamoto earthquake (Mw 7.1) in the Sensuikyo area (1.0 km2) at Aso volcano, Japan. The study area has frequently experienced rainfall-induced landslide events, such as those in 1990, 2001, and 2012. We obtained orthorectified images and digital surface models (DSMs) with a spatial resolution of 0.06 m before and after the 2016 Kumamoto earthquake. By using these high-definition images and DSMs, we detected a total of 54 coseismic landslides with volumes of 9.1-3994.6 m3. These landslides, many of which initiated near topographic ridges, were typically located on upside hillslopes of previous rainfall-induced landslide scars that formed in 2012. This result suggests that the topographic effect on seismic waves, i.e., amplification of ground acceleration, was important for coseismic landslide initiation in the study area. The average depth of the coseismic landslides was 1.5 m, which is deeper than the depth of the rainfall-induced landslides prior to these. The total sediment production of the coseismic landslides reached 2.5 × 104 m3/km2, which is of the same order as the sediment production triggered by the previous single heavy rainfall event. This result indicates that the effects of the 2016 Kumamoto earthquake in terms of sediment production and topographic changes were similar to those of the rainfall-induced landslide event in the study area.

Redox-Active Star Molecules Incorporating the 4-Benzolypyridinium Cation: Implications for the Charge Transfer Efficiency Along Branches versus Across the Perimeter in Dendrimers

NASA Technical Reports Server (NTRS)

Yang, Jin-Hua; Rawashdeh, Abdel Monem M.; Oh, Woon Su; Sotiriou-Leventis, Chariklia; Leventis, Nicholas

2003-01-01

We report the redox properties of four star systems incorporating the 4-benzoyl-N-alkylpyridinium cation; the redox potential varies along the branches, but remains constant at fixed radii. Voltammetric analysis (cyclic voltammetry and differential pulse voltammetry) shows that only two of the three redox-active centers in the perimeter are electrochemically accessible during potential sweeps as slow as 20 mV/s and as fast as 10 V/s. On the contrary, both redox centers of a branch are accessible electrochemically within the same time frame. These results are discussed in terms of slow through-space charge transfer and the globular 3-D folding of the molecules.

The Role of Extracellular Vesicles in Metastasis

DTIC Science & Technology

2017-10-01

quantitative characterization of each cancerous ESV subpopulation’s role in cargo transfer. Specifically, we aim to (1) optimize an existing...the first quantitative data on which ESV subpopulations (exosomes, MVs, or oncosomes) manipulate the tumor microenvironment, the ESV cargo transferred...without cellular contaminants or without damaging the cargo. A second hindrance has been the lack of quantitative methods for measuring very small

Direct laser writing of micro-supercapacitors on thick graphite oxide films and their electrochemical properties in different liquid inorganic electrolytes.

PubMed

Kumar, Rajesh; Joanni, Ednan; Singh, Rajesh K; da Silva, Everson T S G; Savu, Raluca; Kubota, Lauro T; Moshkalev, Stanislav A

2017-12-01

In this article we demonstrate a simple approach to fabricate interdigitated in-plane electrodes for flexible micro-supercapacitors (MSCs). A nanosecond ultraviolet laser treatment is used to reduce and pattern the electrodes on thick graphite oxide (GO) freestanding films. These laser-treated regions obtained by direct writing provide the conducting channels for electrons in the capacitors. The electrochemical performance of the MSCs was evaluated in the presence of two different electrolytes and they exhibit characteristics of nearly electrical double layer capacitors. The MSCs have areal capacitances as 2.40, 2.23 and 1.62μF/cm 2 for NaOH, Na 2 SO 4 and KCl electrolytes respectively, for measurements performed at the scan rate of 50mV/s. They retain ∼93.1% of their initial capacitances after 3500 cycles (scan rate=80mV/s) in NaOH electrolyte. The proposed laser treatment approach enables facile and fast fabrication of flexible MSCs without the need for tedious processing methods such as photolithographic micro-patterning and deposition of porous carbon or metallic current collectors. Copyright © 2017 Elsevier Inc. All rights reserved.

The mature virion of ectromelia virus, a pathogenic poxvirus, is capable of intrahepatic spread and can serve as a target for delayed therapy.

PubMed

Ma, Xueying; Xu, Ren-Huan; Roscoe, Felicia; Whitbeck, J Charles; Eisenberg, Roselyn J; Cohen, Gary H; Sigal, Luis J

2013-06-01

Orthopoxviruses (OPVs), which include the agent of smallpox (variola virus), the zoonotic monkeypox virus, the vaccine and zoonotic species vaccinia virus, and the mouse pathogen ectromelia virus (ECTV), form two types of infectious viral particles: the mature virus (MV), which is cytosolic, and the enveloped virus (EV), which is extracellular. It is believed that MVs are required for viral entry into the host, while EVs are responsible for spread within the host. Following footpad infection of susceptible mice, ECTV spreads lymphohematogenously, entering the liver at 3 to 4 days postinfection (dpi). Afterwards, ECTV spreads intrahepatically, killing the host. We found that antibodies to an MV protein were highly effective at curing mice from ECTV infection when administered after the virus reached the liver. Moreover, a mutant ECTV that does not make EV was able to spread intrahepatically and kill immunodeficient mice. Together, these findings indicate that MVs are sufficient for the spread of ECTV within the liver and could have implications regarding the pathogenesis of other OPVs, the treatment of emerging OPV infections, as well as strategies for preparedness in case of accidental or intentional release of pathogenic OPVs.

A reduced graphene oxide/Co 3O 4 composite for supercapacitor electrode

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

Xiang, Chengcheng; Li, Ming; Zhi, Mingjia

2013-03-01

20 nm sized Co 3O 4 nanoparticles are in-situ grown on the chemically reduced graphene oxide (rGO) sheets to form a rGO-Co 3O 4 composite during hydrothermal processing. The rGO-Co 3O 4 composite is employed as the pseudocapacitor electrode in the 2 M KOH aqueous electrolyte solution. The rGOCo 3O 4 composite electrode exhibits a specific capacitance of 472 F/g at a scan rate of 2 mV/s in a two-electrode cell. 82.6% of capacitance is retained when the scan rate increases to 100 mV/s. The rGOCo 3O 4 composite electrode shows high rate capability and excellent long-term stability. It alsomore » exhibits high energy density at relatively high power density. The energy density reaches 39.0 Wh/kg at a power density of 8.3 kW/kg. The super performance of the composite electrode is attributed to the synergistic effects of small size and good redox activity of the Co 3O 4 particles combined with high electronic conductivity of the rGO sheets.« less

Spectrum Orbit Utilization Program Documentation: SOUP5 Version 3.8 User's Manual, Volume 2, Appendices a Through G

NASA Technical Reports Server (NTRS)

Davidson, J.; Ottey, H. R.; Sawitz, P.; Zusman, F. S.

1985-01-01

The appendixes of the user manual are presented. Input forms which may be used to prepare data for the SOUP5V3.4 of the R2BCSAT-83 data base are given. The IBM job control language which can be used to run the SOUP5 system from a magnetic tape is described. Copies of a run using the delivered tape and IBM OS/MVS Job Control Language card deck are illustrated. Numerical limits on scenario data requests are listed. Error handling, error messages and editing procedures are also listed. Instructions as to how to enter a protection ratio template are given. And relation between PARC prameter, channelization, channel families, and interference categories are also listed.

40 CFR Appendix A to Subpart II of... - VOC Data Sheet 1

Code of Federal Regulations, 2010 CFR

2010-07-01

...: (Dc)s __ g/L [] ASTM D1475-90 *[] Other 3 B. Total Volatiles: (mv)s __ Mass Percent [] ASTM D2369-93....14. 3 Explain the other method used under “Remarks.” [] ASTM D3792-91 *[] ASTM D4017-81, 90, or 96a... (nonvolatiles) 2. __ g/L coating (less water and exempt compounds) G. Thinner Density: Dth __ g/L ASTM...

Circadian force and EMG activity in hindlimb muscles of rhesus monkeys

NASA Technical Reports Server (NTRS)

Hodgson, J. A.; Wichayanuparp, S.; Recktenwald, M. R.; Roy, R. R.; McCall, G.; Day, M. K.; Washburn, D.; Fanton, J. W.; Kozlovskaya, I.; Edgerton, V. R.;

The POIS (Parkland On-Line Information System) Implementation of the IBM Health Care Support/Patient Care System

PubMed Central

Mishelevich, David J.; Hudson, Betty G.; Van Slyke, Donald; Mize, Elaine I.; Robinson, Anna L.; Brieden, Helen C.; Atkinson, Jack; Robertson, James

1980-01-01

The installation of major components of a comprehensive Hospital Information System (HIS) called POIS, the Parkland On-line Information System, including identified success factors is described for the Dallas County Hospital District (DCHD) known also as the Parkland Memorial Hospital. Installation of the on-line IBM Health Care Support (HCS) Registration and Admissions Packages occurred in 1976 and implementation of the HCS Patient Care System (PCS) began in 1977 which includes on-line support of health care areas such as nursing stations and ancillary areas. The Duke Hospital Information System (DHIS) is marketed as the IBM HCS/Patient Care System (PCS). DCHD was the validation site. POIS has order entry, result reporting and work management components. While most of the patient care components are currently installed for the inpatient service, the Laboratories are being installed for the outpatient and Emergency areas as well. The Clinic Appointment System developed at the University of Michigan is also installed. The HCS family of programs use DL/1 and CICS and were installed in the OS versions, currently running under MVS on an IBM 370/168 Model 3 with 8 megabytes of main memory. ImagesFigure 1-AFigure 1-B

Kinetics of nickel electrodeposition from low electrolyte concentration and at a narrow interelectrode gap

NASA Astrophysics Data System (ADS)

Widayatno, Tri

2015-12-01

Electrodeposition of nickel onto copper in a system of low Ni2+ concentration and at a narrow interelectrode gap has been carried out. This electrochemical system was required for maskless pattern transfer through electroplating (Enface technique). Kinetics of Electrochemical reaction of Nickel is relatively slow, where such electrochemical system has never been used in this technology. Study on the kinetics of the electrochemical reaction of nickel in such system is essential due to the fact that the quality of an electrodeposited nickel is affected by kinetics. Analytical and graphical methods were utilised to determine kinetic parameters. The kinetic model was approximated by Butler-Volmer and j-η equation. Kinetic parameters such as exchange current density (j0) and charge transfer coefficient (α) were also graphically determined using the plot of η vs. log|j| known as Tafel plot. The polarisation data for an unstirred 0.19 M nickel sulfamate solution at 0.5 mV/s scan rate and RDE system was used. The results indicate that both methods are fairly accurate. For the analytical, the Tafel slope, the exchange current density, and charge transfer coefficient were found to be 149 mV/dec, 1.60 × 10-4 mA/cm2, and 0.39 respectively, whilst for the graphical method were 159 mV/dec, 3.16 × 10-4 mA/cm2, and 0.37. The kinetics parameters in this current study were also compared to those in literature. Significant differences were observed which might be due to the effect of composition and concentration of the electrolytes, operating temperature, and pH leading to the different reaction mechanism. However, the results obtained in this work are in the range of acceptable values. These kinetic parameters will then be used in further study of nickel deposition by modelling and simulation

Direct Reprogramming of Human Amniotic Fluid Stem Cells by OCT4 and Application in Repairing of Cerebral Ischemia Damage

PubMed Central

Qin, Mingde; Chen, Ruihua; Li, Hong; Liang, Hansi; Xue, Qun; Li, Fang; Chen, Ying; Zhang, Xueguang

2016-01-01

Amniotic fluid stem cells (AFSCs) are a type of fetal stem cell whose stemness encompasses both embryonic and adult stem cells, suggesting that they may be easily and efficiently reprogrammed into induced pluripotent stem cells (iPSCs). To further simplify the reprogramming process, the creation of AFSC-derived iPSCs using a single factor is desirable. Here we report the generation of one-factor human AFSC-iPSCs (AiPSCs) from human AFSCs by ectopic expression of the transcription factor OCT4. Just like human embryonic stem cells, AiPSCs exhibited similar epigenetic status, global gene expression profiles, teratoma formation and in vitro & in vivo pluripotency. Our results indicate that the OCT4 is necessary and sufficient to directly reprogram human AFSCs into pluripotent AiPSCs. Moreover, reflecting the similar memory characteristics of AFSCs and neural stem cells, we show that AiPSC membrane-derived vesicles (MVs) repair cerebral ischemia damage. We anticipate that the successful generation of one-factor AiPSCs will facilitate the creation of patient-specific pluripotent stem cells without the need for transgenic expression of oncogenes. Moreover, MVs from tissue-specific AiPSCs have potential in tissue repair, representing a novel application of iPSCs. PMID:27019637

Fabrication and characterization of electrochemically prepared bioanode (polyaniline/ferritin/glucose oxidase) for biofuel cell application

NASA Astrophysics Data System (ADS)

ul Haque, Sufia; Inamuddin; Nasar, Abu; Asiri, Abdullah M.

2018-01-01

Porous matrix of polyaniline (PANI) has been electrodeposited along with the entrapment of biocompatible redox mediator ferritin (Frt) and glucose oxidase (GOx) on the surface of glassy carbon (GC) electrode. The characterizations have been carried out by X-ray Diffraction (XRD) and Transmission electron microscopy (TEM). The enhanced electrochemical signal transfer rate from enzyme to the electrode surface was due to the intimate contact of the enzyme with the electrochemically polymerized conducting PANI matrix. The PANI/Frt/GOx modified GC bioanode was used to investigate the electrocatalytic activity as a function of the concentration of glucose in the range of 10-60 mM. It was confirmed by the electrochemical impedance spectroscopy (EIS), the thick deposition of PANI layer becomes more compact due to which the charge transfer resistance of PANI matrix becomes higher. All the electrochemical measurements of the electrode were carried out by using cyclic voltammetry (CV) and linear sweep voltammetry (LSV). CV curves were recorded at different scan rates (20-100 mV/s) at 50 mM of glucose in 0.3 M potassium ferrocyanide. A normalized saturation current density of 22.3 ± 2 mA/cm2 was observed for the oxidation of 50 mM glucose at a scan rate of 100 mV/s.

Investigation on Electrochemical Properties of Polythiophene Nanocomposite with Graphite Derivatives as Supercapacitor Material on Breath Figure-Decorated PMMA Electrode

NASA Astrophysics Data System (ADS)

Azimi, Mona; Abbaspour, Mohsen; Fazli, Ali; Setoodeh, Hamideh; Pourabbas, Behzad

2018-03-01

Breath figures have been formed by the direct breath figure method on polymethyl methacrylate electrode sand hexagonal oriented holes with 0.5- to 10- μm2 surface area have been created. Deposition of materials on the electrodes has been performed by the spray-coating method. polythiophene (PTh) nanoparticles, polythiophene-graphene oxide (PTh-GO) and polythiophene-reduced graphene oxide (PTh-G) nanocomposites were synthesized by emulsion polymerization, while characterization of synthetic materials have been carried out by Fourier transform infrared, Χ-ray diffraction, transmission electron microscopy, UV-Vis spectroscopy and field emission scanning electron microscopy techniques. Also, the electrochemical properties of the designed electrodes were investigated by cyclic voltammetry, galvanostatic charge-discharge and electrochemical impedance spectroscopy techniques. Specific capacitance of porous electrodes coated by PTh nanoparticles, PTh-GO and PTh-G nanocomposites were calculated from cyclic voltammetry curves at 5 mV/s scan rate, andthe values are 3.5 F/g, 16.39 F/g, and 28.68 F/g, respectively. Also, the energy density of each electrode at 5 mV/s scan rate has been calculated and the results show that incorporation of GO and G nanolayers with PTh nanoparticles enhances the electrochemical properties of electrodes.

Improving cluster-based missing value estimation of DNA microarray data.

PubMed

Brás, Lígia P; Menezes, José C

2007-06-01

We present a modification of the weighted K-nearest neighbours imputation method (KNNimpute) for missing values (MVs) estimation in microarray data based on the reuse of estimated data. The method was called iterative KNN imputation (IKNNimpute) as the estimation is performed iteratively using the recently estimated values. The estimation efficiency of IKNNimpute was assessed under different conditions (data type, fraction and structure of missing data) by the normalized root mean squared error (NRMSE) and the correlation coefficients between estimated and true values, and compared with that of other cluster-based estimation methods (KNNimpute and sequential KNN). We further investigated the influence of imputation on the detection of differentially expressed genes using SAM by examining the differentially expressed genes that are lost after MV estimation. The performance measures give consistent results, indicating that the iterative procedure of IKNNimpute can enhance the prediction ability of cluster-based methods in the presence of high missing rates, in non-time series experiments and in data sets comprising both time series and non-time series data, because the information of the genes having MVs is used more efficiently and the iterative procedure allows refining the MV estimates. More importantly, IKNN has a smaller detrimental effect on the detection of differentially expressed genes.

[Morbility at the Instituto Nacional de Neurología y Neurocirugía Manuel Velasco Suárez, 1995-2001].

PubMed

Jiménez-Marcial, María Esther; Velásquez-Pérez, Leora

2004-01-01

Hospital statistics are very important as tools that help to define research objectives and design health programs. To determine the main causes of hospital morbility at the Manuel Velasco Suárez National Institute of Neurology and Neurosurgery (MVS-NINN) between 1995 and 2001. Data were taken from the electronic database of morbidity and mortality of MVS-NINN. All outpatient records between 1995 and 2001 were considered. We calculated trends and specific rates of morbidity per 100 discharged patients. The main causes of morbility were brain tumors, schizophrenic illness, neurocysticercosis, and stroke. We found a statistically significant declining time-trend of schizophrenic illness and in non-traumatic brain hemorrhage in males. In the case of females, we observed an increasing time-trend of benign meningeal tumors. The age groups more affected in both genders were those < 51 years of age. This study is not a population study, but it helps to increase knowledge of the main causes of hospitalization at one of the most important neurologic institutions in the world, which provides care for thinsured population throughout Mexico. These findings facilitate analysis and decision-making to undertake specifications to improve the quality of neurologic medical attention.

Classification of Strawberry Fruit Shape by Machine Learning

NASA Astrophysics Data System (ADS)

Ishikawa, T.; Hayashi, A.; Nagamatsu, S.; Kyutoku, Y.; Dan, I.; Wada, T.; Oku, K.; Saeki, Y.; Uto, T.; Tanabata, T.; Isobe, S.; Kochi, N.

2018-05-01

Shape is one of the most important traits of agricultural products due to its relationships with the quality, quantity, and value of the products. For strawberries, the nine types of fruit shape were defined and classified by humans based on the sampler patterns of the nine types. In this study, we tested the classification of strawberry shapes by machine learning in order to increase the accuracy of the classification, and we introduce the concept of computerization into this field. Four types of descriptors were extracted from the digital images of strawberries: (1) the Measured Values (MVs) including the length of the contour line, the area, the fruit length and width, and the fruit width/length ratio; (2) the Ellipse Similarity Index (ESI); (3) Elliptic Fourier Descriptors (EFDs), and (4) Chain Code Subtraction (CCS). We used these descriptors for the classification test along with the random forest approach, and eight of the nine shape types were classified with combinations of MVs + CCS + EFDs. CCS is a descriptor that adds human knowledge to the chain codes, and it showed higher robustness in classification than the other descriptors. Our results suggest machine learning's high ability to classify fruit shapes accurately. We will attempt to increase the classification accuracy and apply the machine learning methods to other plant species.

Region of interest extraction based on multiscale visual saliency analysis for remote sensing images

NASA Astrophysics Data System (ADS)

Zhang, Yinggang; Zhang, Libao; Yu, Xianchuan

2015-01-01

Region of interest (ROI) extraction is an important component of remote sensing image processing. However, traditional ROI extraction methods are usually prior knowledge-based and depend on classification, segmentation, and a global searching solution, which are time-consuming and computationally complex. We propose a more efficient ROI extraction model for remote sensing images based on multiscale visual saliency analysis (MVS), implemented in the CIE L*a*b* color space, which is similar to visual perception of the human eye. We first extract the intensity, orientation, and color feature of the image using different methods: the visual attention mechanism is used to eliminate the intensity feature using a difference of Gaussian template; the integer wavelet transform is used to extract the orientation feature; and color information content analysis is used to obtain the color feature. Then, a new feature-competition method is proposed that addresses the different contributions of each feature map to calculate the weight of each feature image for combining them into the final saliency map. Qualitative and quantitative experimental results of the MVS model as compared with those of other models show that it is more effective and provides more accurate ROI extraction results with fewer holes inside the ROI.

Synergic effect studies of the bi-enzymatic system laccase-peroxidase in a voltammetric biosensor for catecholamines.

PubMed

Leite, Oldair D; Lupetti, Karina O; Fatibello-Filho, Orlando; Vieira, Iolanda C; Barbosa, Aneli de M

2003-04-10

Several bi-enzymatic carbon paste biosensors modified with enzymes laccase from Pleurotus ostreatus fungi and peroxidase from zucchini (Cucurbita pepo) were constructed for evaluating the synergic effect of the two enzymes on the voltammetric biosensor response for various catecholamines. Initially was investigated the effect of pH from 5.0 to 7.5, temperature from 25 to 50 degrees C, initial stirring time from 30 to 150 s, scan rate from 10 to 60 mVs(-1) and potential pulse amplitude from 10 to 60 mV on the biosensor response for several catecholamines such as dopamine, adrenaline, isoprenaline and l-dopa. It was observed a biosensor signal increase employing both enzymes, indicating thus there is a synergic effect between laccase and peroxidase, verified also in spectrophotometric studies, in the determination of these catecholamines.

Oxygen Activation and Photoelectrochemical Oxidation on Oxide Surfaces

DTIC Science & Technology

2013-12-04

electrolysis followed by product determination from mass spectroscopy showed that acetophenone was produced with a 95% Faradaic efficiency. The H/D kinetic...vs. NHE) 10 electrode: scan rate, 100mV/s. (b) Plot of catalytic currents during electrolysis at −1.38 V, icat (background subtracted), vs...controlled potential electrolysis at 3.0 V at two boron doped diamond electrodes (~0.85 cm2). Red line: background current without added catalyst

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

Finnerty, W.R.

We have sought the structural elucidation of the glycolipid biosurfactant. The extracellular glycolipid consists of 1 major component (>90%) plus 6--7 minor molecular species. The deacylated water-soluble backbone is common to all molecular species of the glycolipid. A complex fatty acid composition characterizes the glycolipid and contributes to its surface active character. The water soluble backbone consists of glycerol, trehalose and 3--5 glucose residues. FTIR spectroscopy has confirmed the presence of these polyhydric components. The next major objective has been to clone the genes for glycolipid biosynthesis in Rhodococcus sp. H13-A. Improvements in the E. coli-Rhodococcus shuttle vector, pMVS301, weremore » made prior to the construction and screening of a genomic library in Rhodococcus. A system is being developed for transpositional mutagenesis in Rhodococcus, using Tn917 containing plasmids used successfully in Bacillus sp. for the isolation and analysis of sporulation and developmental genes. We are also actively assessing the utility of this cloning and transformation system which we have developed for Rhodococcus, for use in mycobacterium, a related Actinomycete for which there exists no systems for plasmid transformation or molecular cloning. 8 refs., 1 fig.« less

Excimer laser assisted very fast exfoliation and reduction of graphite oxide at room temperature under air ambient for Supercapacitors electrode

NASA Astrophysics Data System (ADS)

Malek Hosseini, S. M. B.; Baizaee, S. M.; Naderi, Hamid Reza; Dare Kordi, Ali

2018-01-01

Excimer laser was used for reduction and exfoliation of graphite oxide (GO) at room temperature under air ambient. The prepared excimer laser reduced graphite oxide (XLRGO) is characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), nitrogen adsorption/desorption (BET method), X-ray diffraction (XRD), X-ray photoemission spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR) and UV-vis absorption techniques for surface, structural functional groups and band gap analysis. Electrochemical properties are investigated using cyclic voltammetry, galvanostatic charge-discharge, electrochemical impedance spectroscopy (EIS) and continues cyclic voltammetry (CCV) in 0.5 M Na2SO4 as electrolyte. Electrochemical investigations revealed that XLRGO electrode has enhanced supercapacitive performance including specific capacitance of 299 F/g at a scan rate of 2 mV/s. Furthermore, CCV measurement showed that XLRGO electrode kept 97.8% of its initial capacitance/capacity after 4000 cycles. The obtained results from electrochemical investigations confirm that the reduction of GO by using an excimer laser produces high-quality graphene for supercapacitor applications without the need for additional operations.

Chemical synthesis and supercapacitive properties of lanthanum telluride thin film.

PubMed

Patil, S J; Lokhande, A C; Lee, D-W; Kim, J H; Lokhande, C D

2017-03-15

Lanthanum telluride (La 2 Te 3 ) thin films are synthesized via a successive ionic layer adsorption and reaction (SILAR) method. The crystal structure, surface morphology and surface wettability properties are investigated using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Field emission scanning electron microscopy (FE-SEM) and contact angle goniometer techniques, respectively. The La 2 Te 3 material exhibits a specific surface area of 51m 2 g -1 determined by Brunauer-Emmett-Teller (BET) method. La 2 Te 3 thin film electrode has a hydrophilic surface which consists of interconnected pine leaf-like flaky arrays that affect the performance of the supercapacitor. The supercapacitive performance of La 2 Te 3 film electrode is evaluated in 1M LiClO 4 /PC electrolyte using cyclic voltammetry, galvanostatic charge-discharge, and electrochemical impedance spectroscopy techniques. La 2 Te 3 film electrode exhibits a specific capacitance of 194Fg -1 at a scan rate of 5mVs -1 and stored energy density of 60Whkg -1 with delivering power density of 7.22kWkg -1 . La 2 Te 3 film electrode showed capacitive retention of 82% over 1000cycles at a scan rate of 100mVs -1 . Further, flexible La 2 Te 3 |LiClO 4 -PVA|La 2 Te 3 supercapacitor cell is fabricated. Copyright © 2016 Elsevier Inc. All rights reserved.

Fabrication and electrochemical properties of activated CNF/Cu x Mn1- x Fe2O4 composite nanostructures

NASA Astrophysics Data System (ADS)

Nilmoung, Sukanya; Sonsupap, Somchai; Sawangphruk, Montree; Maensiri, Santi

2018-06-01

This work reports the fabrication and electrochemical properties of activated carbon nanofibers composited with copper manganese ferrite (ACNF/Cu x Mn1- x Fe2O4: x = 0.0, 0.2, 0.4, 0.6, 0.8) nanostructures. The obtained samples were characterized by means of X-ray diffraction, field emission scanning electron microscopy, Brunauer-Emmett-Teller analyzer, thermal gravimetric analysis, X-ray photoemission spectroscopy, and X-ray absorption spectroscopy. The supercapacitive behavior of the electrodes is tested using cyclic voltammetery, galvanostatic charge-discharge and electrochemical impedance spectroscopy. By varying ` x', the highest specific capacitance of 384 F/g at 2 mV/s using CV and 314 F/g at 2 A/g using GCD are obtained for the x = 0.2 electrode. The second one of 235 F/g at 2 mV/s using CV and 172 F/g at 2 A/g using GCD are observed for x = 0.8 electrode. The corresponding energy densities are 74 and 41 Wh/kg, respectively. It is observed that the cyclic stability of the prepared samples strongly depend on the amount of carbon, while the specific capacitance was enhanced by the sample with nearly proportional amount between carbon and CuMnFe2O4. Such results may arise from the synergetic effect between CuMnFe2O4 and ACNF.

Stress-Induced Resistive Switching in Pt/HfO2/Ti Devices

NASA Astrophysics Data System (ADS)

Zeevi, Gilad; Katsman, Alexander; Yaish, Yuval E.

2018-02-01

In the present work, we study the initial SET mechanism of resistive switching (RS) in Pt/HfO2/Ti devices under a static electrical stress and the RS mechanism under a bias sweeping mode with rates of 100 mV/s-300 mV/s. We characterize the thin HfO2 dielectric layer by x-ray photoelectron spectroscopy and x-ray diffraction. These findings show that the layer structure is stoichiometric and nanocrystalline with a crystal diameter of ˜ 14 Å. We measure the temporal dependence of the conductive filament growth at different temperatures and for various biases. Furthermore, these devices present stable bipolar resistive switching with a high-to-low resistive state (HRS/LRS) ratio of more than three orders of magnitude. Activation energy E RS ≈ 0.56 eV and drift current parameter V 0 ≈ 0.07 V were determined from the temporal dependence of the initial `SET' process, first HRS to LRS transition [for static electrical stress of V DS = (4.7-5.0 V)]. We analyze the results according to our model suggesting generation of double-charge oxygen vacancies at the anode and their diffusion across the dielectric layer. The double-charge vacancies transform to a single charge and then to neutral vacancies by capturing hot electrons, and form a conductive filament as soon as a critical neutral-vacancy cluster is formed across the dielectric layer.

Exosomes: the ideal nanovectors for biodelivery.

PubMed

Fais, Stefano; Logozzi, Mariantonia; Lugini, Luana; Federici, Cristina; Azzarito, Tommaso; Zarovni, Natasa; Chiesi, Antonio

2013-01-01

Nanomedicine aims to exploit the improved and often novel physical, chemical, and biological properties of materials at the nanometric scale, possibly with the highest level of biomimetism, an approach that simulates what occurs in nature. Although extracellularly released vesicles include both microvesicles (MVs) and exosomes, only exosomes have the size that may be considered suitable for potential use in nanomedicine. In fact, recent reports have shown that exosomes are able to interact with target cells within an organ or at a distance using different mechanisms. Much is yet to be understood about exosomes, and currently, we are looking at the visible top of an iceberg, with most of what we have to understand on these nanovesicles still under the sea. In fact, we know that exosomes released by normal cells always trigger positive effects, whereas those released by cells in pathological condition, such as tumor or infected cells, may induce undesired, dangerous, and mostly unknown effects, but we cannot exclude the possibility that exosomes may also be detrimental for the body in normal conditions. However, whether we consider extracellular vesicles as a whole, thus including MVs, it appears that even in normal conditions, extracellular vesicles may lead to unwanted effects, depending on gender and age. This review aims to critically emphasize existing data in the literature that support the possible roles of exosomes in both diagnostic and therapeutic scopes.

Broadly Neutralizing Immune Responses against Hepatitis C Virus Induced by Vectored Measles Viruses and a Recombinant Envelope Protein Booster

PubMed Central

Reyes-del Valle, Jorge; de la Fuente, Cynthia; Turner, Mallory A.; Springfeld, Christoph; Apte-Sengupta, Swapna; Frenzke, Marie E.; Forest, Amelie; Whidby, Jillian; Marcotrigiano, Joseph; Rice, Charles M.

2012-01-01

Hepatitis C virus (HCV) infection remains a serious public health problem worldwide. Treatments are limited, and no preventive vaccine is available. Toward developing an HCV vaccine, we engineered two recombinant measles viruses (MVs) expressing structural proteins from the prototypic HCV subtype 1a strain H77. One virus directs the synthesis of the HCV capsid (C) protein and envelope glycoproteins (E1 and E2), which fold properly and form a heterodimer. The other virus expresses the E1 and E2 glycoproteins separately, with each one fused to the cytoplasmic tail of the MV fusion protein. Although these hybrid glycoproteins were transported to the plasma membrane, they were not incorporated into MV particles. Immunization of MV-susceptible, genetically modified mice with either vector induced neutralizing antibodies to MV and HCV. A boost with soluble E2 protein enhanced titers of neutralizing antibody against the homologous HCV envelope. In animals primed with MV expressing properly folded HCV C-E1-E2, boosting also induced cross-neutralizating antibodies against two heterologous HCV strains. These results show that recombinant MVs retain the ability to induce MV-specific humoral immunity while also eliciting HCV neutralizing antibodies, and that anti-HCV immunity can be boosted with a single dose of purified E2 protein. The use of MV vectors could have advantages for pediatric HCV vaccination. PMID:22896607

Effects of high intensity exercise on isoelectric profiles and SDS-PAGE mobility of erythropoietin.

PubMed

Voss, S; Lüdke, A; Romberg, S; Schänzer, E; Flenker, U; deMarees, M; Achtzehn, S; Mester, J; Schänzer, W

2010-06-01

Exercise induced proteinuria is a common phenomenon in high performance sports. Based on the appearance of so called "effort urines" in routine doping analysis the purpose of this study was to investigate the influence of exercise induced proteinuria on IEF profiles and SDS-PAGE relative mobility values (rMVs) of endogenous human erythropoietin (EPO). Twenty healthy subjects performed cycle-ergometer exercise until exhaustion. VO (2)max, blood lactate, urinary proteins and urinary creatinine were analysed to evaluate the exercise performance and proteinuria. IEF and SDS-PAGE analyses were performed to test for differences in electrophoretic behaviour of the endogenous EPO before and after exercise. All subjects showed increased levels of protein/creatinine ratio after performance (8.8+/-5.2-26.1+/-14.4). IEF analysis demonstrated an elevation of the relative amount of basic band areas (13.9+/-11.3-36.4+/-12.6). Using SDS-PAGE analysis we observed a decrease in rMVs after exercise and no shift in direction of the recombinant human EPO (rhEPO) region (0.543+/-0.013-0.535+/-0.012). Following identification criteria of the World Anti Doping Agency (WADA) all samples were negative. The implementation of the SDS-PAGE method represents a good solution to distinguish between results influenced by so called effort urines and results of rhEPO abuse. Thus this method can be used to confirm adverse analytical findings.

Mesoporous carbon synthesized from different pore sizes of SBA-15 for high density electrode supercapacitor application

NASA Astrophysics Data System (ADS)

Jamil, Farinaa Md; Sulaiman, Mohd Ali; Ibrahim, Suhaina Mohd; Masrom, Abdul Kadir; Yahya, Muhd Zu Azhan

2017-12-01

A series of mesoporous carbon sample was synthesized using silica template, SBA-15 with two different pore sizes. Impregnation method was applied using glucose as a precursor for converting it into carbon. An appropriate carbonization and silica removal process were carried out to produce a series of mesoporous carbon with different pore sizes and surface areas. Mesoporous carbon sample was then assembled as electrode and its performance was tested using cyclic voltammetry and impedance spectroscopy to study the effect of ion transportation into several pore sizes on electric double layer capacitor (EDLC) system. 6M KOH was used as electrolyte at various scan rates of 10, 20, 30 and 50 mVs-1. The results showed that the pore size of carbon increased as the pore size of template increased and the specific capacitance improved as the increasing of the pore size of carbon.

Microwave assisted synthesis of graphene oxide - MnO2 nanocomposites for electrochemical supercapacitors

NASA Astrophysics Data System (ADS)

Vimuna, V. M.; Athira, A. R.; Xavier, T. S.

2018-05-01

Grapheneoxide-MnO2 nanocomposite was successfully synthesized through the self-limiting deposition of nano scale MnO2 on the surface of graphene oxide under microwave- irradiation in a water- isopropyl alcohol system. The structural and morphological properties of as synthesized samples have been studied. These nanostructured graphene oxide-MnO2 (GMC) hybrid materials are used for investigation of electrochemical behaviours. It was found that the electrochemical performance of as prepared nanocomposite could be enhanced by chemical interaction between GO and MnO2. Cyclic voltammetry is employed to assess the properties of these nanocomposites for use in supercapacitors. The specific capacitance of the synthesized sample corresponding to scan rate of 20mV/s is calculated to be 280 Fg-1. Furthermore, we emphasize the fabrication challenges and future perspectives of such materials for energy storage.

ZMOTTO- MODELING THE INTERNAL COMBUSTION ENGINE

NASA Technical Reports Server (NTRS)

Zeleznik, F. J.

1994-01-01

The ZMOTTO program was developed to model mathematically a spark-ignited internal combustion engine. ZMOTTO is a large, general purpose program whose calculations can be established at five levels of sophistication. These five models range from an ideal cycle requiring only thermodynamic properties, to a very complex representation demanding full combustion kinetics, transport properties, and poppet valve flow characteristics. ZMOTTO is a flexible and computationally economical program based on a system of ordinary differential equations for cylinder-averaged properties. The calculations assume that heat transfer is expressed in terms of a heat transfer coefficient and that the cylinder average of kinetic plus potential energies remains constant. During combustion, the pressures of burned and unburned gases are assumed equal and their heat transfer areas are assumed proportional to their respective mass fractions. Even the simplest ZMOTTO model provides for residual gas effects, spark advance, exhaust gas recirculation, supercharging, and throttling. In the more complex models, 1) finite rate chemistry replaces equilibrium chemistry in descriptions of both the flame and the burned gases, 2) poppet valve formulas represent fluid flow instead of a zero pressure drop flow, and 3) flame propagation is modeled by mass burning equations instead of as an instantaneous process. Input to ZMOTTO is determined by the model chosen. Thermodynamic data is required for all models. Transport properties and chemical kinetics data are required only as the model complexity grows. Other input includes engine geometry, working fluid composition, operating characteristics, and intake/exhaust data. ZMOTTO accommodates a broad spectrum of reactants. The program will calculate many Otto cycle performance parameters for a number of consecutive cycles (a cycle being an interval of 720 crankangle degrees). A typical case will have a number of initial ideal cycles and progress through levels of nonideal cycles. ZMOTTO has restart capabilities and permits multicycle calculations with parameters varying from cycle to cycle. ZMOTTO is written in FORTRAN IV (IBM Level H) but has also been compiled with IBM VSFORTRAN (1977 standard). It was developed on an IBM 3033 under the TSS operating system and has also been implemented under MVS. Approximately 412K of 8 bit bytes of central memory are required in a nonpaging environment. ZMOTTO was developed in 1985.

Magnetic field measurements of a clinical MR imager at 1.5 tesla

NASA Astrophysics Data System (ADS)

Muhech, A.; Tellez, I.; Esteva, M.; Marrufo, O.; Jimenez, L.; Vazquez, F.; Taboada, J.; Rodriguez, A. O.

2012-10-01

In the clinical environment is mandatory to run periodically measurements of uniformity of the magnetic field produced by the magnet to assure good image quality. The phase difference method was used to measure the magnetic field uniformity of the 1.5 T scanner of the Instituto Nacional de Neurologia y Neurocirugia MVS. The uniformity field values showed that the imager performance is reasonably good for clinical imaging. Some concern was raised since results may not be good enough for magnetic resonance spectroscopy runs.

Electrochemical way of molybdenum extraction from the Bimetallic systems of Mo-W

NASA Astrophysics Data System (ADS)

Kudreeva, L. K.; Nauryzbaev, M. K.; Kurbatov, A. P.; Kamysbaev, D. H.; Adilbekova, A. O.; Mukataeva, Z. S.

2015-12-01

Electrochemical dissolution of molybdenum and tungsten was investigated in water- dimethylsulfoxide (DMSO) media at different concentrations of lithium chloride and magnesium perchlorate. The terms of efficient extraction of molybdenum from bimetallic systems of Mo-W have been determined. The polarization curves of the electrooxidation of molybdenum in the solution of 0.25 M LiCl in the DMSO at the different rates of rotations and the scan rate equal to 50 mV/s were obtained. In the presence of the addition of water at the potential of 0.1-0.75 V the small area of polarizability occurs, then with increasing potentials above 1.5 V there is a sharp increase of the oxidation current. Comparison of the current values of anodic dissolution of molybdenum and tungsten showed that the rate of anodic dissolution of molybdenum significantly exceeds the rate of anodic dissolution of tungsten. In the case of molybdenum, the dissolution process is limited by diffusion, in the case of tungsten - by the passive film formation on the electrode surface.

Transparent, flexible, and high-performance supercapacitor based on ultrafine nickel cobaltite nanospheres

NASA Astrophysics Data System (ADS)

Liu, Xinyue; Wang, Jianxing; Yang, Guowei

2017-07-01

There has been growing interest in transparent and flexible electronic devices such as wrist watch, cell phone, and so on. These devices need the power sources which also have transparent and flexible features. Here, we demonstrate a transparent and flexible energy storage device with outstanding electrochemical performance, high energy density, and super-long life based on ultrafine NiCo2O4 nanospheres which are synthesized by an innovative method concerning laser ablation in liquid and hydrothermal process. The ultrafine NiCo2O4 nanospheres provide high electrochemical activity and the synthesized colloidal solution is suitable for transparent devices. The transparent and flexible device shows a high specific capacitance of 299.7 F/g at the scan rate of 1 mV/s and a long cycling life of 90.4% retention rate after 10,000 cycles at a scan rate of 10 mV/s, which is superior to that of previously reported transparent and flexible energy storage device. In addition, an optical transmittance up to 55% at the wavelength of 550 nm is obtained, and the bending test shows that the bending angle makes no difference to the specific capacitance of the device. In addition, it shows an outstanding energy density of 10.41 Wh/kg. The integrated electrochemical performances of the device are good based on NiCo2O4 nanospheres. These findings make the ultrafine NiCo2O4 nanospheres being promising electrode materials for transparent and flexible energy storage devices.

Microstructure and pseudocapacitive properties of electrodes constructed of oriented NiO-TiO2 nanotube arrays.

PubMed

Kim, Jae-Hun; Zhu, Kai; Yan, Yanfa; Perkins, Craig L; Frank, Arthur J

2010-10-13

We report on the synthesis and electrochemical properties of oriented NiO-TiO(2) nanotube (NT) arrays as electrodes for supercapacitors. The morphology of the films prepared by electrochemically anodizing Ni-Ti alloy foils was characterized by scanning and transmission electron microscopies, X-ray diffraction, and photoelectron spectroscopies. The morphology, crystal structure, and composition of the NT films were found to depend on the preparation conditions (anodization voltage and postgrowth annealing temperature). Annealing the as-grown NT arrays to a temperature of 600 °C transformed them from an amorphous phase to a mixture of crystalline rock salt NiO and rutile TiO(2). Changes in the morphology and crystal structure strongly influenced the electrochemical properties of the NT electrodes. Electrodes composed of NT films annealed at 600 °C displayed pseudocapacitor (redox-capacitor) behavior, including rapid charge/discharge kinetics and stable long-term cycling performance. At similar film thicknesses and surface areas, the NT-based electrodes showed a higher rate capability than the randomly packed nanoparticle-based electrodes. Even at the highest scan rate (500 mV/s), the capacitance of the NT electrodes was not much smaller (within 12%) than the capacitance measured at the slowest scan rate (5 mV/s). The faster charge/discharge kinetics of NT electrodes at high scan rates is attributed to the more ordered NT film architecture, which is expected to facilitate electron and ion transport during the charge-discharge reactions.

Assessment of a new silicone tri-leaflet valve seamlessly assembled with blood chamber for a low-cost ventricular assist device.

PubMed

Hirai, S; Fukunaga, S; Sueshiro, M; Watari, M; Sueda, T; Matsuura, Y

1998-06-01

We have developed a practical, low-cost ventricular assist device (VAD) comprising a newly designed blood chamber with a silicone lenticular sac and two silicone tri-leaflet valves (STV), made en bloc. This new VAD is seamless, can be made cost-effectively and assembled with the blood chamber and valve as one body. This novel design should reduce the incident of thrombus formation because of the absence of a junction at the connecting ring and because of the use of flexible silicone materials which have both antithrombogenecity and biocompatibility. In in vitro hemodynamics testing, a batch of 3 consecutively manufactured VADs with STVs underwent hydrodynamic functional testing. These showed less regurgitation, a lower value of water hammer phenomenon, and a slightly greater pressure gradient across the valves than a mechanical valve (MV) [Björk-Shiley monostrut valve]. The flow and pulsatile efficiency were adequate and similar to that of a VAD with MVs. In in vitro durability and hemolysis tests, a VAD with STV functioned well for 54 days and showed similar hemolytic profiles to a VAD with MVs. In an in vivo acute experiment using an adult sheep, our device was problem-free providing sufficient output as a left ventricular assist device (LVAD). Although it will be necessary to decrease the pressure gradient across this STV in the future, our device showed efficient performance as a practical land cost-effective VAD for short term use.

Real-time database drawn from an electronic health record for a thoracic surgery unit: high-quality clinical data saving time and human resources.

PubMed

Salati, Michele; Pompili, Cecilia; Refai, Majed; Xiumè, Francesco; Sabbatini, Armando; Brunelli, Alessandro

2014-06-01

The aim of the present study was to verify whether the implementation of an electronic health record (EHR) in our thoracic surgery unit allows creation of a high-quality clinical database saving time and costs. Before August 2011, multiple individuals compiled the on-paper documents/records and a single data manager inputted selected data into the database (traditional database, tDB). Since the adoption of an EHR in August 2011, multiple individuals have been responsible for compiling the EHR, which automatically generates a real-time database (EHR-based database, eDB), without the need for a data manager. During the initial period of implementation of the EHR, periodic meetings were held with all physicians involved in the use of the EHR in order to monitor and standardize the data registration process. Data quality of the first 100 anatomical lung resections recorded in the eDB was assessed by measuring the total number of missing values (MVs: existing non-reported value) and inaccurate values (wrong data) occurring in 95 core variables. The average MV of the eDB was compared with the one occurring in the same variables of the last 100 records registered in the tDB. A learning curve was constructed by plotting the number of MVs in the electronic database and tDB with the patients arranged by the date of registration. The tDB and eDB had similar MVs (0.74 vs 1, P = 0.13). The learning curve showed an initial phase including about 35 records, where MV in the eDB was higher than that in the tDB (1.9 vs 0.74, P = 0.03), and a subsequent phase, where the MV was similar in the two databases (0.7 vs 0.74, P = 0.6). The inaccuracy rate of these two phases in the eDB was stable (0.5 vs 0.3, P = 0.3). Using EHR saved an average of 9 min per patient, totalling 15 h saved for obtaining a dataset of 100 patients with respect to the tDB. The implementation of EHR allowed streamlining the process of clinical data recording. It saved time and human resource costs, without compromising the quality of data. © The Author 2014. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

Development of Waterfall Cliff Face: An Implication from Multitemporal High-definition Topographic Data

NASA Astrophysics Data System (ADS)

Hayakawa, Y. S.; Obanawa, H.

2015-12-01

Bedrock knickpoints (waterfalls) often act as erosional front in bedrock rivers, whose geomorphological processes are various. In waterfalls with vertical cliffs, both fluvial erosion and mass movement are feasible to form the landscape. Although morphological changes of such steep cliffs are sometimes visually observed, quantitative and precise measurements of their spatiotemporal distribution have been limited due to poor accessibility to such cliffs. For the clarification of geomorphological processes in such cliffs, multi-temporal mapping of the cliff face at a high resolution can be advantaged by short-range remote sensing approaches. Here we carry out multi-temporal terrestrial laser scanning (TLS), as well as structure-from-motion multi-view stereo (SfM-MVS) photogrammetry based on unmanned aerial system (UAS) for accurate topographic mapping of cliffs around a waterfall. The study site is Kegon Falls in central Japan, having a vertical drop of surface water from top of its overhanging cliff and groundwater outflows from its lower portions. The bedrock consists of alternate layers of jointed andesite lava and conglomerates. The latest major rockfall in 1986 caused approximately 8-m recession of the waterfall lip. Three-dimensional changes of the rock surface were detected by multi-temporal measurements by TLS over years, showing the portions of small rockfalls and surface lowering in the bedrock. Erosion was frequently observed in relatively weak the conglomerates layer, whereas small rockfalls were often found in the andesite layers. Wider areas of the waterfall and cliff were also measured by UAS-based SfM-MVS photogrammetry, improving the mapping quality of the cliff morphology. Point clouds are also projected on a vertical plane to generate a digital elevation model (DEM), and cross-sectional profiles extracted from the DEM indicate the presence of a distinct, 5-10-m deep depression in the cliff face. This appears to have been formed by freeze-thaw and/or wet-dry weathering following the recession in 1986. The long-term development of the waterfall cliff face is then discussed comprising various processes of rockfalls, water pressure and weathering.

Three-Dimensional Modeling of Weed Plants Using Low-Cost Photogrammetry

PubMed Central

Andújar, Dionisio; Fernández-Quintanilla, César; Dorado, José

2018-01-01

Sensing advances in plant phenotyping are of vital importance in basic and applied plant research. Plant phenotyping enables the modeling of complex shapes, which is useful, for example, in decision-making for agronomic management. In this sense, 3D processing algorithms for plant modeling is expanding rapidly with the emergence of new sensors and techniques designed to morphologically characterize. However, there are still some technical aspects to be improved, such as an accurate reconstruction of end-details. This study adapted low-cost techniques, Structure from Motion (SfM) and MultiView Stereo (MVS), to create 3D models for reconstructing plants of three weed species with contrasting shape and plant structures. Plant reconstruction was developed by applying SfM algorithms to an input set of digital images acquired sequentially following a track that was concentric and equidistant with respect to the plant axis and using three different angles, from a perpendicular to top view, which guaranteed the necessary overlap between images to obtain high precision 3D models. With this information, a dense point cloud was created using MVS, from which a 3D polygon mesh representing every plants’ shape and geometry was generated. These 3D models were validated with ground truth values (e.g., plant height, leaf area (LA) and plant dry biomass) using regression methods. The results showed, in general, a good consistency in the correlation equations between the estimated values in the models and the actual values measured in the weed plants. Indeed, 3D modeling using SfM algorithms proved to be a valuable methodology for weed phenotyping, since it accurately estimated the actual values of plant height and LA. Additionally, image processing using the SfM method was relatively fast. Consequently, our results indicate the potential of this budget system for plant reconstruction at high detail, which may be usable in several scenarios, including outdoor conditions. Future research should address other issues, such as the time-cost relationship and the need for detail in the different approaches. PMID:29614039

Estimating 3D Leaf and Stem Shape of Nursery Paprika Plants by a Novel Multi-Camera Photography System

PubMed Central

Zhang, Yu; Teng, Poching; Shimizu, Yo; Hosoi, Fumiki; Omasa, Kenji

2016-01-01

For plant breeding and growth monitoring, accurate measurements of plant structure parameters are very crucial. We have, therefore, developed a high efficiency Multi-Camera Photography (MCP) system combining Multi-View Stereovision (MVS) with the Structure from Motion (SfM) algorithm. In this paper, we measured six variables of nursery paprika plants and investigated the accuracy of 3D models reconstructed from photos taken by four lens types at four different positions. The results demonstrated that error between the estimated and measured values was small, and the root-mean-square errors (RMSE) for leaf width/length and stem height/diameter were 1.65 mm (R2 = 0.98) and 0.57 mm (R2 = 0.99), respectively. The accuracies of the 3D model reconstruction of leaf and stem by a 28-mm lens at the first and third camera positions were the highest, and the number of reconstructed fine-scale 3D model shape surfaces of leaf and stem is the most. The results confirmed the practicability of our new method for the reconstruction of fine-scale plant model and accurate estimation of the plant parameters. They also displayed that our system is a good system for capturing high-resolution 3D images of nursery plants with high efficiency. PMID:27314348

Neural networks for data compression and invariant image recognition

NASA Technical Reports Server (NTRS)

Gardner, Sheldon

1989-01-01

An approach to invariant image recognition (I2R), based upon a model of biological vision in the mammalian visual system (MVS), is described. The complete I2R model incorporates several biologically inspired features: exponential mapping of retinal images, Gabor spatial filtering, and a neural network associative memory. In the I2R model, exponentially mapped retinal images are filtered by a hierarchical set of Gabor spatial filters (GSF) which provide compression of the information contained within a pixel-based image. A neural network associative memory (AM) is used to process the GSF coded images. We describe a 1-D shape function method for coding of scale and rotationally invariant shape information. This method reduces image shape information to a periodic waveform suitable for coding as an input vector to a neural network AM. The shape function method is suitable for near term applications on conventional computing architectures equipped with VLSI FFT chips to provide a rapid image search capability.

Ginsenoside Rb1 inhibits autophagy through regulation of Rho/ROCK and PI3K/mTOR pathways in a pressure-overload heart failure rat model.

PubMed

Yang, Tianrui; Miao, Yunbo; Zhang, Tong; Mu, Ninghui; Ruan, Libo; Duan, Jinlan; Zhu, Ying; Zhang, Rongping

2018-06-01

This study was designed to explore the relationship between ginsenoside Rb1 (Grb1) and high-load heart failure (HF) in rats. The parameters of cardiac systolic function (left ventricular posterior wall thickness (LVPWT), left ventricular internal diastolic diameter (LVID), fraction shortening (FS) and mitral valves (MVs)) of rat hearts in each group were inspected by echocardiogram. The expressions of rat myocardial contractile proteins, autophagy-related proteins and the activation of Rho/ROCK and PI3K/mTOR pathways were detected by Western blot. LVPWT, FS, MVs and the expression of myocardial contractile proteins α-MHC, apoptosis-related proteins Bcl-2 and signalling pathway involved proteins pAkt and mTOR were significantly reduced in the HF, HF+5 mg/kg Grb1 (HF+Grb1-5) and HF+Grb1+arachidonic acid (AA) groups with LVID, β-MHC, cell apoptosis, cell autophagy and Rho/ROCK significantly increased compared with the control group, of which the tendency was contrary to the HF+20 mg/kg Grb1 (HF+Grb1-20) group compared with the HF group (P < 0.05). In the HF+Grb1+AA group, there was no significant change in the above indexes compared with the HF group. The results indicated that Grb1 can exert anti-HF function by inhibiting cardiomyocyte autophagy of rats through regulation of Rho/ROCK and PI3K/mTOR pathways. © 2018 Royal Pharmaceutical Society.

Optimizing Land and Water Use at the Local Level to Enhance Global Food Security through Virtual Resources Trade in the World

NASA Astrophysics Data System (ADS)

Cai, X.; Zhang, X.; Zhu, T.

2014-12-01

Global food security is constrained by local and regional land and water availability, as well as other agricultural input limitations and inappropriate national and global regulations. In a theoretical context, this study assumes that optimal water and land uses in local food production to maximize food security and social welfare at the global level can be driven by global trade. It follows the context of "virtual resources trade", i.e., utilizing international trade of agricultural commodities to reduce dependency on local resources, and achieves land and water savings in the world. An optimization model based on the partial equilibrium of agriculture is developed for the analysis, including local commodity production and land and water resources constraints, demand by country, and global food market. Through the model, the marginal values (MVs) of social welfare for water and land at the level of so-called food production units (i.e., sub-basins with similar agricultural production conditions) are derived and mapped in the world. In this personation, we will introduce the model structure, explain the meaning of MVs at the local level and their distribution around the world, and discuss the policy implications for global communities to enhance global food security. In particular, we will examine the economic values of water and land under different world targets of food security (e.g., number of malnourished population or children in a future year). In addition, we will also discuss the opportunities on data to improve such global modeling exercises.

Hexagonal nanorods of tungsten trioxide: Synthesis, structure, electrochemical properties and activity as supporting material in electrocatalysis

NASA Astrophysics Data System (ADS)

Salmaoui, Samiha; Sediri, Faouzi; Gharbi, Néji; Perruchot, Christian; Aeiyach, Salah; Rutkowska, Iwona A.; Kulesza, Pawel J.; Jouini, Mohamed

2011-07-01

Tungsten trioxide, unhydrated with hexagonal structure (h-WO 3), has been prepared by hydrothermal method at a temperature of 180 °C in acidified sodium tungstate solution. Thus prepared h-WO 3 has been characterized by X-ray diffraction (XRD) method and using electrochemical techniques. The morphology has been examined by scanning and transmission electron microscopies (SEM and TEM) and it is consistent with existence of nanorods of 50-70 nm diameter and up to 5 μm length. Cyclic voltammetric characterization of thin films of h-WO 3 nanorods has revealed reversible redox behaviour with charge-discharge cycling corresponding to the reversible lithium intercalation/deintercalation into the crystal lattice of the h-WO 3 nanorods. In propylene carbonate containing LiClO 4, two successive redox processes of hexagonal WO 3 nanorods are observed at the scan rate of 50 mV/s. Such behaviour shall be attributed to the presence of at least two W atoms of different surroundings in the lattice structure of h-WO 3 nanorods. On the other hand, in aqueous LiClO 4 solution, only one redox process is observed at the scan rate of 10 mV/s. The above observations can be explained in terms of differences in the diffusion of ions inside two types of channel cavities existing in the structure of the h-WO 3 nanorods. Moreover, the material can be applied as active support for the catalytic bi-metallic Pt-Ru nanoparticles during electrooxidation of ethanol in acid medium (0.5 mol dm -3 H 2SO 4).

A sparse matrix-vector multiplication based algorithm for accurate density matrix computations on systems of millions of atoms

NASA Astrophysics Data System (ADS)

Ghale, Purnima; Johnson, Harley T.

2018-06-01

We present an efficient sparse matrix-vector (SpMV) based method to compute the density matrix P from a given Hamiltonian in electronic structure computations. Our method is a hybrid approach based on Chebyshev-Jackson approximation theory and matrix purification methods like the second order spectral projection purification (SP2). Recent methods to compute the density matrix scale as O(N) in the number of floating point operations but are accompanied by large memory and communication overhead, and they are based on iterative use of the sparse matrix-matrix multiplication kernel (SpGEMM), which is known to be computationally irregular. In addition to irregularity in the sparse Hamiltonian H, the nonzero structure of intermediate estimates of P depends on products of H and evolves over the course of computation. On the other hand, an expansion of the density matrix P in terms of Chebyshev polynomials is straightforward and SpMV based; however, the resulting density matrix may not satisfy the required constraints exactly. In this paper, we analyze the strengths and weaknesses of the Chebyshev-Jackson polynomials and the second order spectral projection purification (SP2) method, and propose to combine them so that the accurate density matrix can be computed using the SpMV computational kernel only, and without having to store the density matrix P. Our method accomplishes these objectives by using the Chebyshev polynomial estimate as the initial guess for SP2, which is followed by using sparse matrix-vector multiplications (SpMVs) to replicate the behavior of the SP2 algorithm for purification. We demonstrate the method on a tight-binding model system of an oxide material containing more than 3 million atoms. In addition, we also present the predicted behavior of our method when applied to near-metallic Hamiltonians with a wide energy spectrum.

Development of an off bypass mitral valve repair.

PubMed

Morales, D L; Madigan, J D; Choudhri, A F; Williams, M R; Helman, D N; Elder, J B; Naka, Y; Oz, M C

1999-01-01

The Bow Tie Repair (BTR), a single edge-to-edge suture opposing the anterior and posterior leaflets of the mitral valve (MV), has led to satisfactory reduction of mitral regurgitation (MR) with few re-operations and excellent hemodynamic results. The simplicity of the repair lends itself to minimally invasive approaches. A MV grasper has been developed that will coapt both leaflets and fasten the structures with a graduated spiral screw. Eleven explanted adult human MVs were mounted in a mock circulatory loop created for simulating a variety of hemodynamic conditions. The MV grasper was used to place a screw in each valve, which was then continuously run for 300,000 to 1,000,000 cycles with a fixed transvalvular pressure gradient. At the completion of these studies, the valves were stressed to a maximal transvalvular gradient for ten minutes. In seven cases, MR was induced and subsequently repaired using the MV screw. In vivo, the MV screw was tested in nine male canines. Through a subcostal incision, the MV grasper entered the left ventricle, approximated the mitral leaflets and deployed the MV screw under direct visualization via an atriotomy. Follow-up transthoracic echocardiograms were done at postoperative week 1, 6, and 12 to identify screw migration, MV regurgitation/stenosis or clot formation. Dogs were sacrificed up to postoperative week 12 to allow gross and histologic assessment. In vitro, no MV screw detached from the valve leaflets or migrated during the durability testing period of 6.8 million cycles, including periods of stress load testing up to 350 mm Hg. The percent regurgitant flow used to assess MR statistically decreased with the placement of the screw from 72 +/- 7% to 34 +/- 17%; p = 0.0025. In vivo, seven dogs whose valves were examined within the first 48 hours revealed leaflet coaptation with an intact MV screw and no evidence of MR. Two dogs, followed for a prolonged period, had serial postoperative echocardiograms demonstrating consistent coaptation, no screw migration, no clot, and no regurgitation or stenosis. In the animal sacrificed at 12 weeks, the MV screw was integrated into the tissue of both leaflets. The MV screw has provided durable leaflet coaptation and has reduced regurgitation in human MVs. Initial data on the MV screw's biocompatibility and interactions with living valve tissue is promising. Our early success supports further efforts towards the maturation of this prototype into off bypass mitral valve repair technology.

Detection of morphological changes in cliff face surrounding a waterfall using terrestrial laser scanning and unmanned aerial system

NASA Astrophysics Data System (ADS)

Hayakawa, Yuichi S.; Obanawa, Hiroyuki

2015-04-01

Waterfall or bedrock knickpoint appears as an erosional front in bedrock rivers forming deep v-shaped valley downstream. Following the rapid fluvial erosion of waterfall, rockfalls and gravita-tional collapses often occur in surrounding steep cliffs. Although morphological changes of such steep cliffs are sometimes visually observed, quantitative and precise measurements of their spatio-temporal distribution have been limited due to the difficulties in direct access to such cliffs if with classical measurement methods. However, for the clarification of geomorphological processes oc-curring in the cliffs, multi-temporal mapping of the cliff face at a high resolution is necessary. Re-mote sensing approaches are therefore suitable for the topographic measurements and detection of changes in such inaccessible cliffs. To achieve accurate topographic mapping of cliffs around a wa-terfall, here we perform multi-temporal terrestrial laser scanning (TLS), as well as structure-from-motion multi-view stereo (SfM-MVS) photogrammetry based on unmanned aerial system (UAS). The study site is Kegon Falls in central Japan, having a vertical drop of surface water from top of its overhanging cliff, as well as groundwater outflows from its lower portions. The bedrock is composed of alternate layers of andesite lava and conglomerates. Minor rockfalls in the cliffs are often ob-served by local people. The latest major rockfall occurred in 1986, causing ca. 8-m upstream propa-gation of the waterfall lip. This provides a good opportunity to examine the changes in the surround-ing cliffs following the waterfall recession. Multi-time point clouds were obtained by TLS measure-ment over years, and the three-dimensional changes of the rock surface were detected, uncovering the locus of small rockfalls and gully developments. Erosion seems particularly frequent in relatively weak the conglomerates layer, whereas small rockfalls seems to have occurred in the andesite layers. Also, shadows in the TLS point clouds are effectively filled by complementary data of UAS-based SfM-MVS photogrammetry, which can improve the mapping quality of the cliff morphology. The point clouds are also projected on a vertical plane to generate a digital elevation model (DEM). Cross-sectional profiles extracted from the DEM show the presence of a distinct, 5-10-m depression at the mid of the cliff (bottom of the upper andesite layer), which appears to have been formed by freeze-thaw and/or wet-dry weathering following the waterfall recession in 1986.

Role of Additives in Minimizing Zinc Electrode Shape Change: The Effect of Lead on the Kinetics of Zn(II) Reduction in Concentrated Alkaline Media.

DTIC Science & Technology

1985-07-01

adherent, and showed excellent physical stability. U -12- 4. RESULTS AND DISCUSSION 4.1 CYCLIC VOLTAMETRY AT A SILVER DISK ELECTRODE Silver screens are...45% KOH containing 5.5% ZnO is shown in Figure 17A. Several sweeps are recorded at scan rates of 10, 20, 50, 100, 200, and 500 mV/s with the highest...voltammetry curves is difficult since the anodic peak depends on the amount of metal deposition in the previous cathodic sweep (16).) The peak currents versus

Guidance, Navigation and Control Digital Emulation Technology Laboratory. Volume 1. Part 3. Task 1: Digital Emulation Technology Laboratory

DTIC Science & Technology

1991-09-27

ISTT IEXIT IGO MAGV TGII ROLLERI YAWER LA !10 TRMTGO TGE 1 TGE2ALI IBURNI ACQD UVs MVS CMMD VCMD IFTAB TFTAB ACSLEV DTOFFV IVTAB TB URNM TI MONVI TVTAB...Volume 1, Part 3 C b inertdfatal loup ndxjust compu ed . Missile states must not CI C transition has occurred since the last C C integration step . The...SUBROUTINE RESP2R ( DT,WD,ZD,CILL,CIL,CI., COLL ,COL,CO) C C SUBROUTINE NAME : RESP2R C C AUTHOR(S) :D. F. SMITH C C FUNCTION Given a second

Improving pH sensitivity by field-induced charge regulation in flexible biopolymer electrolyte gated oxide transistors

NASA Astrophysics Data System (ADS)

Liu, Ning; Gan, Lu; Liu, Yu; Gui, Weijun; Li, Wei; Zhang, Xiaohang

2017-10-01

Electrical manipulation of charged ions in electrolyte-gated transistors is crucial for enhancing the electric-double-layer (EDL) gating effect, thereby improving their sensing abilities. Here, indium-zinc-oxide (IZO) based thin-film-transistors (TFTs) are fabricated on flexible plastic substrate. Acid doped chitosan-based biopolymer electrolyte is used as the gate dielectric, exhibiting an extremely high EDL capacitance. By regulating the dynamic EDL charging process with special gate potential profiles, the EDL gating effect of the chitosan-gated TFT is enhanced, and then resulting in higher pH sensitivities. An extremely high sensitivity of ∼57.8 mV/pH close to Nernst limit is achieved when the gate bias of the TFT sensor sweeps at a rate of 10 mV/s. Additionally, an enhanced sensitivity of 2630% in terms of current variation with pH range from 11 to 3 is realized when the device is operated in the ion depletion mode with a negative gate bias of -0.7 V. Robust ionic modulation is demonstrated in such chitosan-gated sensors. Efficiently driving the charged ions in the chitosan-gated IZO-TFT provides a new route for ultrasensitive, low voltage, and low-cost biochemical sensing technologies.

Glucose biosensor based on the immobilization of glucose oxidase on electrochemically synthesized polypyrrole-poly(vinyl sulphonate) composite film by cross-linking with glutaraldehyde.

PubMed

Colak, Ozlem; Yaşar, Ahmet; Cete, Servet; Arslan, Fatma

2012-10-01

In this study, a novel amperometric glucose biosensor was developed by immobilizing glucose oxidase (GOX) by cross-linking via glutaraldehyde on electrochemically polymerized polypyrrole-poly(vinyl sulphonate) (PPy-PVS) films on the surface of a platinum (Pt) electrode. Electropolymerization of pyrrole and poly(vinyl sulphonate) on the Pt surface was carried out with an electrochemical cell containing pyrrole and poly(vinyl sulphonate) by cyclic voltammetry between -1.0 and + 2.0 V (vs.Ag/AgCl) at a scan rate of 50 mV/s upon the Pt electrode. The amperometric determination was based on the electrochemical detection of H(2)O(2) generated in enzymatic reaction of glucose. Determination of glucose was carried out by the oxidation of enzymatically produced H(2)O(2) at 0.4 V vs. Ag/AgCl. The effects of pH and temperature were investigated and optimum parameters were found to be 7.5 and 65°C, respectively. The effect of working potential was investigated and optimum potential was determined to be 0.4 V. The operational stability of the enzyme electrode was also studied. The response of the PPy/PVS-GOX glucose biosensor exhibited good reproducibility with a relative standard deviation (RSD) of 2.48%. The glucose biosensor retained 63% of initial activity after 93 days when stored in 0.1 M phosphate buffer solution of pH 7.5 at 4°C. With the low operating potential, the biosensor demonstrated little interference from the possible interferants.

Synthesis and Microstructural Characterization of Manganese Oxide Electrodes for Application as Electrochemical Supercapacitors

NASA Astrophysics Data System (ADS)

Babakhani, Banafsheh

The aim of this thesis work was to synthesize Mn-based oxide electrodes with high surface area structures by anodic electrodeposition for application as electrochemical capacitors. Rod-like structures provide large surface areas leading to high specific capacitances. Since templated electrosynthesis of rods is not easy to use in practical applications, it is more desirable to form rod-like structures without using any templates. In this work, Mn oxide electrodes with rod-like structures (˜1.5 µm in diameter) were synthesized from a solution of 0.01 M Mn acetate under galvanostatic control without any templates, on Au coated Si substrates. The electrochemical properties of the synthesized nanocrystalline electrodes were investigated to determine the effect of morphology, chemistry and crystal structure on the corresponding electrochemical behavior of Mn oxide electrodes. Mn oxides prepared at different current densities showed a defective antifluoritetype crystal structure. The rod-like Mn oxide electrodes synthesized at low current densities (5 mAcm.2) exhibited a high specific capacitance due to their large surface areas. Also, specific capacity retention after 250 cycles in an aqueous solution of 0.5 M Na2SO4 at 100 mVs -1 was about 78% of the initial capacity (203 Fg-1 ). To improve the electrochemical capacitive behavior of Mn oxide electrodes, a sequential approach and a one-step method were adopted to synthesize Mn oxide/PEDOT electrodes through anodic deposition on Au coated Si substrates from aqueous solutions. In the former case, free standing Mn oxide rods (about 10 µm long and less than 1.5 µm in diameter) were first synthesized, then coated by electro-polymerization of a conducting polymer (PEDOT) giving coaxial rods. The one-step, co-electrodeposition method produced agglomerated Mn oxide/PEDOT particles. The electrochemical behavior of the deposits depended on the morphology and crystal structure of the fabricated electrodes, which were affected by the composition and pH of the electrolyte, temperature, current density and polymer deposition time. Mn oxide/PEDOT coaxial core/shell rods consisted of MnO2 with an antifluorite-type structure coated with amorphous PEDOT. The Mn oxide/PEDOT coaxial core/shell electrodes prepared by the sequential method showed significantly better specific capacity and redox performance properties relative to both uncoated Mn oxide rods and co- electrodeposited Mn oxide/PEDOT electrodes. The best specific capacitance for Mn oxide/PEDOT rods produced sequentially was ˜295 F g-1 with ˜92% retention after 250 cycles in 0.5 M Na2SO4 at 100 mV s-1. To further improve the electrochemical capacitive behavior of Mn oxide electrodes, Co-doped and Fe-doped Mn oxide electrodes with a rod-like morphology and antifluorite-type crystal structure were synthesized by anodic electrodeposition, on Au coated Si substrates, from dilute solutions of Mn acetate and Co sulphate and Mn acetate and Fe chloride. Also, Mn-Co oxide/PEDOT coaxial core/shell rods were synthesized by applying a shell of PEDOT on Mn-Co oxide electrodes. Mn-Co oxide/PEDOT electrodes consisted of MnO2, with partial Co 2+ and Co3+ ion substitution for Mn4+, and amorphous PEDOT. Mn-Fe oxide electrodes consisted of MnO2, with partial Fe2+ and Fe3+ ion substitution for Mn4+. Electrochemical analysis showed that the capacitance values for all deposits increased with increasing scan rate to 100 mVs -1, and then decreased after 100 mVs-1. The Mn-Co oxide/PEDOT electrodes showed improved specific capacity and electrochemical cyclability relative to uncoated Mn-Co oxides and Mn-Fe oxides. Mn-Co oxide/PEDOT electrodes with rod-like structures had high capacitances (up to 310 Fg -1) at a scan rate of 100 mVs-1 and maintained their capacitance after 500 cycles in 0.5 M Na2SO4 (91% retention). Capacitance reduction for the deposits was mainly due to the loss of Mn ions by dissolution in the electrolyte solution. To better understand the nucleation and growth mechanisms of Mn oxide electrodes, the effects of supersaturation ratio on the morphology and crystal structure of electrodeposited Mn oxide were studied. By changing deposition parameters, including deposition current density, electrolyte composition, pH and temperature, a series of nanocrystalline Mn oxide electrodes with various morphologies (continuous coatings, rod-like structures, aggregated rods and thin sheets) and an antifluorite-type crystal structure was obtained. Mn oxide thin sheets showed instantaneous nucleation and single crystalline growth; rods had a mix of instantaneous/progressive nucleation and polycrystalline growth and continuous coatings formed by progressive nucleation and polycrystalline growth. Electrochemical analysis revealed the best capacitance behaviour obtained for Mn oxide thin sheets followed by Mn oxide rods, with dimensions on the microscale, and then continuous coatings. The highest specific capacitance (˜230 Fg-1) and capacitance retention rates (˜88%) were obtained for Mn oxide thin sheets after 250 cycles in 0.5 M Na2 SO4 at 20 mVs-1.

Effects of pH on the Production of Phosphate and Pyrophosphate by Matrix Vesicles' Biomimetics

PubMed Central

Simão, Ana Maria S.; Bolean, Maytê; Hoylaerts, Marc F.; Millán, José Luis; Ciancaglini, Pietro

2013-01-01

During endochondral bone formation, chondrocytes and osteoblasts synthesize and mineralize the extracellular matrix through a process that initiates within matrix vesicles (MVs) and ends with bone mineral propagation onto the collagenous scaffold. pH gradients have been identified in the growth plate of long bones, but how pH changes affect the initiation of skeletal mineralization is not known. Tissue-nonspecific alkaline phosphatase (TNAP) degrades extracellular inorganic pyrophosphate (ePPi), a mineralization inhibitor produced by ectonucleotide pyrophosphatase/ phosphodiesterase-1 (NPP1), while contributing Pi from ATP to initiate mineralization. TNAP and NPP1, alone or combined, were reconstituted in dipalmitoylphosphatidylcholine (DPPC) liposomes to mimic the microenvironment of MVs. The hydrolysis of ATP, ADP, AMP and PPi was studied at pH 8 and 9 and compared to the data determined at pH 7.4. While catalytic efficiencies in general were higher at alkaline pH, PPi hydrolysis was maximal at pH 8 and indicated a preferential utilization of PPi over ATP, at pH 8 versus 9. In addition, all proteoliposomes induced mineral formation when incubated in a synthetic cartilage lymph (SCL) containing 1 mM ATP as substrate and amorphous calcium phosphate (ACP) or calciumphosphate- phosphatidylserine complexes (PS-CPLX) as nucleators. Propagation of mineralization was significantly more efficient at pHs 7.5 and 8 than at pH 9. Since a slight pH elevation from 7.4 to 8 promotes considerably more hydrolysis of ATP, ADP and AMP primarily by TNAP, this small pH change facilitates mineralization, especially via upregulated PPi hydrolysis by both NPP1 and TNAP, further elevating the Pi/PPi ratio, thus enhancing bone mineralization. PMID:23942722

Effects of pH on the production of phosphate and pyrophosphate by matrix vesicles' biomimetics.

PubMed

Simão, Ana Maria S; Bolean, Maytê; Hoylaerts, Marc F; Millán, José Luis; Ciancaglini, Pietro

2013-09-01

During endochondral bone formation, chondrocytes and osteoblasts synthesize and mineralize the extracellular matrix through a process that initiates within matrix vesicles (MVs) and ends with bone mineral propagation onto the collagenous scaffold. pH gradients have been identified in the growth plate of long bones, but how pH changes affect the initiation of skeletal mineralization is not known. Tissue-nonspecific alkaline phosphatase (TNAP) degrades extracellular inorganic pyrophosphate (PPi), a mineralization inhibitor produced by ectonucleotide pyrophosphatase/phosphodiesterase-1 (NPP1), while contributing Pi from ATP to initiate mineralization. TNAP and NPP1, alone or combined, were reconstituted in dipalmitoylphosphatidylcholine liposomes to mimic the microenvironment of MVs. The hydrolysis of ATP, ADP, AMP, and PPi was studied at pH 8 and 9 and compared to the data determined at pH 7.4. While catalytic efficiencies in general were higher at alkaline pH, PPi hydrolysis was maximal at pH 8 and indicated a preferential utilization of PPi over ATP at pH 8 versus 9. In addition, all proteoliposomes induced mineral formation when incubated in a synthetic cartilage lymph containing 1 mM ATP as substrate and amorphous calcium phosphate or calcium-phosphate-phosphatidylserine complexes as nucleators. Propagation of mineralization was significantly more efficient at pH 7.5 and 8 than at pH 9. Since a slight pH elevation from 7.4 to 8 promotes considerably more hydrolysis of ATP, ADP, and AMP primarily by TNAP, this small pH change facilitates mineralization, especially via upregulated PPi hydrolysis by both NPP1 and TNAP, further elevating the Pi/PPi ratio, thus enhancing bone mineralization.

The thermodynamic and transport properties of GdCl3 in molten eutectic LiCl-KCl derived from the analysis of cyclic voltammetry signals

NASA Astrophysics Data System (ADS)

Samin, Adib; Wu, Evan; Zhang, Jinsuo

2017-02-01

Pyroprocessing technology is a promising tool for recycling nuclear fuel and producing high purity gadolinium for industrial applications. An efficient implementation of pyroprocessing entails a careful characterization of the electrochemical and transport properties of lanthanides in high temperature molten salts. In this work, the cyclic voltammetry signals of Gd in molten LiCl-KCl salt were recorded for a combination of three temperatures (723 K, 773 K, and 823 K) and three concentration levels (3 wt. %, 6 wt. %, and 9 wt. %) including concentration levels higher than previously reported and relevant for a realistic application of pyroprocessing for molten salt recycle, and the concentration effects were investigated. Four scan rates (200 mV/s to 500 mV/s) were used for each condition, and the signals were examined using conventional Cyclic Voltammetry (CV) analysis equations and by utilizing a two-plate Brunauer, Emmett, and Teller (BET) model accounting for mass diffusion, kinetics, adsorption, and the evolution of electrode morphology via a nonlinear least squares procedure for fitting the model to the experimental signals. It was determined that the redox process is quasi-reversible for the scan rates being used. Furthermore, the applicability of the conventional equations for CV analysis was shown to be problematic for the conditions used, and this is thought to be due to the fact that these equations were derived under the assumption of reversible conditions. The model-derived values for diffusivity are consistent with the literature and are shown to decrease with increasing concentration. This may be due to increased interactions at higher concentration levels. It was also shown that the formal redox potential increased with a concentration and was slightly more positive on the covered electrode.

Morphology Effect of Vertical Graphene on the High Performance of Supercapacitor Electrode.

PubMed

Zhang, Yu; Zou, Qionghui; Hsu, Hua Shao; Raina, Supil; Xu, Yuxi; Kang, Joyce B; Chen, Jun; Deng, Shaozhi; Xu, Ningsheng; Kang, Weng P

2016-03-23

Graphene and its composites are widely investigated as supercapacitor electrodes due to their large specific surface area. However, the severe aggregation and disordered alignment of graphene sheets hamper the maximum utilization of its surface area. Here we report an optimized structure for supercapacitor electrode, i.e., the vertical graphene sheets, which have a vertical structure and open architecture for ion transport pathway. The effect of morphology and orientation of vertical graphene on the performance of supercapacitor is examined using a combination of model calculation and experimental study. Both results consistently demonstrate that the vertical graphene electrode has a much superior performance than that of lateral graphene electrode. Typically, the areal capacitances of a vertical graphene electrode reach 8.4 mF/cm(2) at scan rate of 100 mV/s; this is about 38% higher than that of a lateral graphene electrode and about 6 times higher than that of graphite paper. To further improve its performance, a MnO2 nanoflake layer is coated on the surface of graphene to provide a high pseudocapacitive contribution to the overall areal capacitance which increases to 500 mF/cm(2) at scan rate of 5 mV/s. The reasons for these significant improvements are studied in detail and are attributed to the fast ion diffusion and enhanced charge storage capacity. The microscopic manipulation of graphene electrode configuration could greatly improve its specific capacitance, and furthermore, boost the energy density of supercapacitor. Our results demonstrate that the vertical graphene electrode is more efficient and practical for the high performance energy storage device with high power and energy densities.

Prestroke Proteomic Changes in Cerebral Microvessels in Stroke-Prone, Transgenic[hCETP]-Hyperlipidemic, Dahl Salt-Sensitive Hypertensive Rats

PubMed Central

Bergerat, Agnes; Decano, Julius; Wu, Chang-Jiun; Choi, Hyungwon; Nesvizhskii, Alexey I; Moran, Ann Marie; Ruiz-Opazo, Nelson; Steffen, Martin; Herrera, Victoria LM

2011-01-01

Stroke is the third leading cause of death in the United States with high rates of morbidity among survivors. The search to fill the unequivocal need for new therapeutic approaches would benefit from unbiased proteomic analyses of animal models of spontaneous stroke in the prestroke stage. Since brain microvessels play key roles in neurovascular coupling, we investigated prestroke microvascular proteome changes. Proteomic analysis of cerebral cortical microvessels (cMVs) was done by tandem mass spectrometry comparing two prestroke time points. Metaprotein-pathway analyses of proteomic spectral count data were done to identify risk factor–induced changes, followed by QSPEC-analyses of individual protein changes associated with increased stroke susceptibility. We report 26 cMV proteome profiles from male and female stroke-prone and non–stroke-prone rats at 2 months and 4.5 months of age prior to overt stroke events. We identified 1,934 proteins by two or more peptides. Metaprotein pathway analysis detected age-associated changes in energy metabolism and cell-to-microenvironment interactions, as well as sex-specific changes in energy metabolism and endothelial leukocyte transmigration pathways. Stroke susceptibility was associated independently with multiple protein changes associated with ischemia, angiogenesis or involved in blood brain barrier (BBB) integrity. Immunohistochemical analysis confirmed aquaporin-4 and laminin-α1 induction in cMVs, representative of proteomic changes with >65 Bayes factor (BF), associated with stroke susceptibility. Altogether, proteomic analysis demonstrates significant molecular changes in ischemic cerebral microvasculature in the prestroke stage, which could contribute to the observed model phenotype of microhemorrhages and postischemic hemorrhagic transformation. These pathways comprise putative targets for translational research of much needed novel diagnostic and therapeutic approaches for stroke. PMID:21519634

Post-thrombotic syndrome after central venous catheter removal in childhood cancer survivors: A prospective cohort study.

PubMed

Polen, E; Weintraub, M; Stoffer, C; Jaffe, D H; Burger, A; Revel-Vilk, S

2015-02-01

Although the use of central venous catheters (CVCs) has greatly improved the quality of care of children with cancer, these catheters increase the risk of deep vein thrombosis (DVT) and the potential long-term complication of post-thrombotic syndrome (PTS). We aimed to study PTS post-CVC removal using physical, functional and health related quality of life (HRQoL) domains in childhood cancer and bone marrow transplantation (BMT) survivors. We conducted a prospective study in a cohort of childhood cancer and BMT survivors post-CVC use. Participants were evaluated for PTS with the Modified Villalta Score (MVS) and the Manco-Johnson Instrument (MJI). HRQoL was assessed using the PedsQL™ questionnaire. A total of 158 children were enrolled at a median of 41 (4-149) months from CVC removal. Signs and symptoms of PTS were present in 34% (95% confidence interval [CI] 27-43%) (MVS criteria) and 30.5% (95% CI 23.1-37.8%) (MJI criteria). Diagnosis of PTS was associated with history of CVC occlusion, history of CVC-related DVT and the use of ≥2 CVCs. The presence of signs and symptoms of PTS was a predictor for low HRQoL tested by the PedsQL™ Total Scale scores and Physical Health Summary scores. PTS post-CVC removal in pediatric cancer survivors is not a rare event. The association between PTS and the history of CVC occlusion confirms earlier findings, and suggests that CVC occlusion may indicate asymptomatic DVT. PTS is also associated with lower HRQoL scores highlighting the need to study preventive measures, especially for high risk groups. Pediatr Blood Cancer 2015;62:285-290. © 2014 Wiley Periodicals, Inc. © 2014 Wiley Periodicals, Inc.

A Study of Carbon Nanofibers and Active Carbon as Symmetric Supercapacitor in Aqueous Electrolyte: A Comparative Study

NASA Astrophysics Data System (ADS)

Daraghmeh, Allan; Hussain, Shahzad; Saadeddin, Iyad; Servera, Llorenç; Xuriguera, Elena; Cornet, Albert; Cirera, Albert

2017-12-01

Symmetric supercapacitors are fabricated by carbon nanofibers (CNF) and activated carbon (AC) using similar proportions of 7 wt% polyvinylidene fluoride (PVDF) polymer binder in an aqueous electrolyte. In this study, a comparison of porous texture and electrochemical performances between CNFs and AC based supercapacitors was carried out. Electrodes were assembled in the cell without a current collector. The prepared electrodes of CNFs and AC present Brunauer-Emmett-Teller (BET) surface area of 83 and 1042 m2/g, respectively. The dominant pore structure for CNFs is mesoporous while for AC is micropore. The results showed that AC provided higher specific capacitance retention up to very fast scan rate of 500 mV/s. AC carbon had a specific capacitance of 334 F/g, and CNFs had 52 F/g at scan rate 5 mV/s in aqueous solution. Also, the results indicate the superior conductivity of CNFs in contrast to AC counterparts. The measured equivalent series resistance (ESR) showed a very small value for CNFs (0.28 Ω) in comparison to AC that has an ESR resistance of (3.72 Ω). Moreover, CNF delivered higher specific power (1860 W/kg) than that for AC (450 W/kg). On the other hand, AC gave higher specific energy (18.1 Wh/kg) than that for CNFs (2 Wh/kg).This indicates that the AC is good for energy applications. Whereas, CNF is good for power application. Indeed, the higher surface area will lead to higher specific capacitance and hence higher energy density for AC. For CNF, lower ESR is responsible for having higher power density. Both CNF and AC supercapacitor exhibit an excellent charge-discharge stability up to 2500 cycles.

Microvesicles derived from Alde-Low EPCs support the wound healing capacity of AT-MSCs.

PubMed

Tu, Tran Cam; Yamashita, Toshiharu; Kato, Toshiki; Nagano, Masumi; Trinh, Nhu Thuy; Hamada, Hiromi; Sato, Fujio; Ohneda, Kinuko; Matsuo-Takasaki, Mami; Ohneda, Osamu

2016-08-12

Mesenchymal stem cells (MSCs) are defined as multipotent cells that can give rise to various kinds of differentiated mesenchymal cells, and are thus considered to be useful for clinical therapy. However, the big hurdles of MSC therapy are the inability of MSCs to reach the appropriate tissues or sites with high efficiency and engraftment after transplantation. In this study, we investigated how adipose tissue-derived MSCs (AT-MSCs) improve their homing ability after intravenous injection. We previously found that human endothelial progenitor cells with low aldehyde dehydrogenase activity (Alde-Low EPCs) are suitable for the treatment of ischemic tissues. In addition, we demonstrated that microvesicles (MVs) derived from Alde-Low EPCs possessed the ability to improve the homing ability of non-functional Alde-High EPCs, resulting in wound healing. We initially transfected MVs derived from Alde-Low EPCs (EMVs) to human AT-MSCs, which were originally unable to cure ischemic tissues by intravenous transplantation. Remarkably, AT-MSC transfected EMVs dramatically repaired the ischemic skin flap compared with AT-MSC derived-MV (MMVs) transfected AT-MSCs or control AT-MSCs. We then found that the expression of CXCR4, an important chemokine receptor for cell migration, was highly elevated in EMV-transfected AT-MSCs. Moreover, AT-MSCs transfected with EMVs, but not control AT-MSCs, migrated to wound sites after intravenous injection. Consequently, CD45(+) inflammatory cells were successfully recruited at the wound sites after the injection of EMV-transfected AT-MSCs. These results demonstrate that EMVs are a useful source to improve the homing ability and wound healing ability of MSCs at the wound sites. Copyright © 2016 Elsevier Inc. All rights reserved.

Nanostructuring effect of multi-walled carbon nanotubes on electrochemical properties of carbon foam as constructive electrode for lead acid battery

NASA Astrophysics Data System (ADS)

Kumar, Rajeev; Kumari, Saroj; Mathur, Rakesh B.; Dhakate, Sanjay R.

2015-01-01

In the present study, nanostructuring effect of multi-walled carbon nanotubes (MWCNTs) on electrochemical properties of coal tar pitch (CTP) based carbon foam (CFoam) was investigated. The different weight fractions of MWCNTs were mixed with CTP and foam was developed from the mixture of CTP and MWCNTs by sacrificial template technique and heat treated at 1,400 and 2,500 °C in inert atmosphere. These foams were characterized by scanning electron microscopy, X-ray diffraction, and potentiostat PARSTAT for cyclic voltammetry. It was observed that, bulk density of CFoam increases with increasing MWCNTs content and decreases after certain amount. The MWCNTs influence the morphology of CFoam and increase the width of ligaments as well as surface area. During the heat treatment, stresses exerting at MWCNTs/carbon interface accelerate ordering of the graphene layer which have positive effect on the electrochemical properties of CFoam. The current density increases from 475 to 675 mA/cm2 of 1,400 °C heat treated and 95 to 210 mA/cm2 of 2,500 °C heat-treated CFoam with 1 wt% MWCNTs. The specific capacitance was decreases with increasing the scan rate from 100 to 1,000 mV/s. In case of 1 % MWCNTs content CFoam the specific capacitance at the scan rate 100 mV/s was increased from 850 to 1,250 μF/cm2 and 48 to 340 μF/cm2 of CFoam heat treated at 1,400 °C and 2,500 °C respectively. Thus, the higher value surface area and current density of MWCNTs-incorporated CFoam heat treated to 1,400 °C can be suitable for lead acid battery electrode with improved charging capability.

Facial synthesis of nanostructured ZnCo2O4 on carbon cloth for supercapacitor application

NASA Astrophysics Data System (ADS)

Patil, Swati J.; Park, Jungsung; Lee, Dong-Weon

2017-12-01

In this work, we have synthesized the ZnCo2O4 electrode by a facial one-step hydrothermal method on a carbon cloth for the supercapacitor application. The structural and phase purity of the prepared electrode material was confirmed by X-ray diffraction (XRD) technique. The surface morphology and elemental stoichiometry were studied using field emission scanning electron microscopy (FE-SEM). The FE-SEM micrograph illustrates that the ZnCo2O4 material is composed of microstrips with a ~0.5 μm width and length in micron uniformly covered the carbon cloth surface. The ZnCo2O4 electrode material further investigated for electrochemical analyses. The cyclic voltammetry results showed that the ZnCo2O4 microstrips electrode exhibited the highest specific capacitance of 1084 F/g at 2 mV/s scan rate. Remarkably, a maximum energy density of 12.5 Wh/kg was attained at a current density of 2 mA/cm2 with the power density of 3.6 kW/kg for the ZnCo2O4 microstrips electrode. Furthermore, the 96.2 % capacitive retention is obtained at a higher scan rate of 100 mV/s after 1000 CV cycles, indicating excellent cycling stability of the ZnCo2O4 microstrips electrode. The frequency-dependent rate capability and an ideal capacitive behaviour of the ZnCo2O4 microstrips electrode were analyzed using impedance analyses; a representing the ion diffusion structure of the material. These results show that the ZnCo2O4 microstrips electrode could be a promising material for supercapacitor application.

Supervised Outlier Detection in Large-Scale Mvs Point Clouds for 3d City Modeling Applications

NASA Astrophysics Data System (ADS)

Stucker, C.; Richard, A.; Wegner, J. D.; Schindler, K.

2018-05-01

We propose to use a discriminative classifier for outlier detection in large-scale point clouds of cities generated via multi-view stereo (MVS) from densely acquired images. What makes outlier removal hard are varying distributions of inliers and outliers across a scene. Heuristic outlier removal using a specific feature that encodes point distribution often delivers unsatisfying results. Although most outliers can be identified correctly (high recall), many inliers are erroneously removed (low precision), too. This aggravates object 3D reconstruction due to missing data. We thus propose to discriminatively learn class-specific distributions directly from the data to achieve high precision. We apply a standard Random Forest classifier that infers a binary label (inlier or outlier) for each 3D point in the raw, unfiltered point cloud and test two approaches for training. In the first, non-semantic approach, features are extracted without considering the semantic interpretation of the 3D points. The trained model approximates the average distribution of inliers and outliers across all semantic classes. Second, semantic interpretation is incorporated into the learning process, i.e. we train separate inlieroutlier classifiers per semantic class (building facades, roof, ground, vegetation, fields, and water). Performance of learned filtering is evaluated on several large SfM point clouds of cities. We find that results confirm our underlying assumption that discriminatively learning inlier-outlier distributions does improve precision over global heuristics by up to ≍ 12 percent points. Moreover, semantically informed filtering that models class-specific distributions further improves precision by up to ≍ 10 percent points, being able to remove very isolated building, roof, and water points while preserving inliers on building facades and vegetation.

Design, fabrication, and evaluation of on-chip micro-supercapacitors

NASA Astrophysics Data System (ADS)

Beidaghi, Majid

Due to the increasing demand for high power and reliable miniaturized energy storage devices, the development of micro-supercapacitors or electrochemical micro-capacitors have attracted much attention in recent years. This dissertation investigates several strategies to develop on-chip micro-supercapacitors with high power and energy density. Micro-supercapacitors based on interdigitated carbon micro-electrode arrays are fabricated through carbon microelectromechanical systems (C-MEMS) technique which is based on carbonization of patterned photoresist. To improve the capacitive behavior, electrochemical activation is performed on carbon micro-electrode arrays. The developed micro-supercapacitors show specific capacitances as high as 75 mFcm-2 at a scan rate of 5 mVs -1 after electrochemical activation for 30 minutes. The capacitance loss is less than 13% after 1000 cyclic voltammetry (CV) cycles. These results indicate that electrochemically activated C-MEMS micro-electrode arrays are promising candidates for on-chip electrochemical micro-capacitor applications. The energy density of micro-supercapacitors was further improved by conformal coating of polypyrrole (PPy) on C-MEMS structures. In these types of micro-devices the three dimensional (3D) carbon microstructures serve as current collectors for high energy density PPy electrodes. The electrochemical characterizations of these micro-supercapacitors show that they can deliver a specific capacitance of about 162.07 mFcm-2 and a specific power of 1.62mWcm -2 at a 20 mVs-1 scan rate. Addressing the need for high power micro-supercapacitors, the application of graphene as electrode materials for micro-supercapacitor was also investigated. The present study suggests a novel method to fabricate graphene-based micro-supercapacitors with thin film or in-plane interdigital electrodes. The fabricated micro-supercapacitors show exceptional frequency response and power handling performance and could effectively charge and discharge at rates as high as 50 Vs-1. CV measurements show that the specific capacitance of the micro-supercapacitor based on reduced graphene oxide and carbon nanotube composites is 6.1 mFcm -2 at scan rate of 0.01Vs-1. At a very high scan rate of 50 Vs-1, a specific capacitance of 2.8 mFcm-2 (stack capacitance of 3.1 Fcm-3) is recorded. This unprecedented performance can potentially broaden the future applications of micro-supercapacitors.

Critical infrastructure monitoring using UAV imagery

NASA Astrophysics Data System (ADS)

Maltezos, Evangelos; Skitsas, Michael; Charalambous, Elisavet; Koutras, Nikolaos; Bliziotis, Dimitris; Themistocleous, Kyriacos

2016-08-01

The constant technological evolution in Computer Vision enabled the development of new techniques which in conjunction with the use of Unmanned Aerial Vehicles (UAVs) may extract high quality photogrammetric products for several applications. Dense Image Matching (DIM) is a Computer Vision technique that can generate a dense 3D point cloud of an area or object. The use of UAV systems and DIM techniques is not only a flexible and attractive solution to produce accurate and high qualitative photogrammetric results but also is a major contribution to cost effectiveness. In this context, this study aims to highlight the benefits of the use of the UAVs in critical infrastructure monitoring applying DIM. A Multi-View Stereo (MVS) approach using multiple images (RGB digital aerial and oblique images), to fully cover the area of interest, is implemented. The application area is an Olympic venue in Attica, Greece, at an area of 400 acres. The results of our study indicate that the UAV+DIM approach respond very well to the increasingly greater demands for accurate and cost effective applications when provided with, a 3D point cloud and orthomosaic.

An automated 3D reconstruction method of UAV images

NASA Astrophysics Data System (ADS)

Liu, Jun; Wang, He; Liu, Xiaoyang; Li, Feng; Sun, Guangtong; Song, Ping

2015-10-01

In this paper a novel fully automated 3D reconstruction approach based on low-altitude unmanned aerial vehicle system (UAVs) images will be presented, which does not require previous camera calibration or any other external prior knowledge. Dense 3D point clouds are generated by integrating orderly feature extraction, image matching, structure from motion (SfM) and multi-view stereo (MVS) algorithms, overcoming many of the cost, time limitations of rigorous photogrammetry techniques. An image topology analysis strategy is introduced to speed up large scene reconstruction by taking advantage of the flight-control data acquired by UAV. Image topology map can significantly reduce the running time of feature matching by limiting the combination of images. A high-resolution digital surface model of the study area is produced base on UAV point clouds by constructing the triangular irregular network. Experimental results show that the proposed approach is robust and feasible for automatic 3D reconstruction of low-altitude UAV images, and has great potential for the acquisition of spatial information at large scales mapping, especially suitable for rapid response and precise modelling in disaster emergency.

Electrochemical Synthesis of Graphene/MnO2 Nano-Composite for Application to Supercapacitor Electrode.

PubMed

Jeong, Kwang Ho; Lee, Hyeon Jeong; Simpson, Michael F; Jeong, Mun

2016-05-01

Graphene/MnO2 nano-composite was electrochemically synthesized for application to an electrode material for electrochemical supercapacitors. The nanosized needle-like MnO2 was obtained by use of a graphene substrate. The prepared composite exhibited an ideal supercapacitive behavior. A capacitance retention of 94% was achieved with a 4 h deposition time (an initial capacitance of 574 mF/cm2 at a scan rate of 20 mV/s) and the retention declined with further deposition time. The results demonstrate enhanced contact between the electrode and electrolyte and improved power density as an electrochemical capacitor.

Enhanced optical and electrochemical properties of polyaniline/cobalt oxide nano composite

NASA Astrophysics Data System (ADS)

Niranjana, M.; Yesappa, L.; Ashokkumar, S. P.; Vijeth, H.; Basappa, M.; Devendrappa, H.

2018-05-01

Polyaniline and its composites at different wt. % of Cobalt oxide nano (PDC1, PDC2 and PDC5) were prepared by in-situ chemical reaction method The optical property was carried out using UV-Vis. Absorption Spectroscopy. The electrochemical property like cyclic voltammetry and galvonostatic charging-discharging was carried out for PANI and PDC nanocomposite electrode materials. A specific capacitance of 212.08 F/g and 336.41 F/g with scan rates 100 and 200 mV/s at 0.4 A/g current density respectively. These results are suggesting PDC composite is a prominent candidate for supercapacitor properties applications.

Spectroscopic and Electrochemical Studies of the Transition Metal Tetrasulfonated Phthalocyanines. Part 5. Voltammetric Studies of Adsorbed Tetrasulfonated Phthalocyanines (MTsPc) in Aqueous Solutions.

DTIC Science & Technology

1985-10-01

atmosphere Immediately after addition of M-TsPc to the supporting electrolyte, the first potential sweep over the given range (e.g., -0.8 to 0.3 V vs. SCE...vs. a-Pd/H electrode) at a sweep rate of 100 mV/s, voltammetric peaks of the hydrogen adsorption/desorption and oxide forma- tion/reduction processes...high sweep rates, e.g., 20 V/s. An OPG electrode standing at open-circuit potential in a Fe(III)-TsPc at potentials between peaks 3 and 4 in Fig. 1

Bioactive films of zein/magnetite magnetically stimuli-responsive for controlled drug release

NASA Astrophysics Data System (ADS)

Marín, Tíffany; Montoya, Paula; Arnache, Oscar; Pinal, Rodolfo; Calderón, Jorge

2018-07-01

The Zein films in two configurations with magnetite nanoparticles (zein/NPs) and magnetite-acetaminophen (zein/NPs/Drug) were used as magnetically stimuli-responsive systems to propose a model of controlled release by dissolution and diffusion mechanism. Composite material films of zein/NPs and zein/NPs/Drug were made by dispersion of magnetite nanoparticles into zein solution then solvent casting of the solution on a flat Teflon substrate. The properties of composite films were analyzed by magnetization curves of (MvsH) and measurements of magnetic force microscopy (MFM). Drug release from the zein/NPs/Drug composite films was determined using a type II dissolution apparatus for a period of 2 h under applied magnetic field conditions. In addition, the diffusion mechanism was tested with zein/NPs films into diffusion cell containing acetaminophen solution for 24 h and using a permanent magnet as a remote trigger device. The results showed that the magnetite nanoparticles contained in the zein/NPs and zein/NPs/Drug composite films are stable, i.e., they do not undergo sufficiently high levels of oxidation as to alter their magnetic properties. Furthermore, the dissolution and diffusion results lead us to conclude that zein composite films effectively behave as stimuli-responsive systems triggered by an external magnetic field applied. The result is a model controlled release system whereby drug release can be controlled by adjusting the magnitude of the applied magnetic field.

The optimization of CMC concentration as graphite binder on the anode of LiFePO4 battery

NASA Astrophysics Data System (ADS)

Hidayat, S.; Cahyono, T.; Mindara, J. Y.; Riveli, N.; Alamsyah, W.; Rahayu, I.

2017-05-01

Recently, the most dominating power supply on the mobile electronics market are rechargeable Lithium-ion batteries. This is because of a higher energy density and a longer lifetime compared to similar rechargeable battery systems. Graphite is commonly used as anode material in the Lithium-ion batteries, because of its excellent electrochemical characteristics and low cost fabrication. In this paper, we reported the optimization of the concentration of the CMC (carboxymethyl cellulose), that acts as the binder for graphite anode. Based on our experimental results, the best composition of graphite : C : CMC is 90 : 8 : 2 in weight %. Anode with such composition has, based on SEM measurement, a relatively good surface morphology, while it also has relatively high conductivity, about 2.68 S/cm. The result of cyclic voltammogram with a scan rate of 10 mV/s in the voltage range of 0 to 1 Volt, shows the peak of reduction voltage at 0.85 Volts and the peak voltage of oxidation is at -1.5 Volt. The performance of the battery system with LiFePO4 set as the cathode, shows that the working voltage is about 2.67 Volts at 1 mA current-loading, with the efficiency around 47%.

Demonstration of plasma start-up by Coaxial Helicity Injection

NASA Astrophysics Data System (ADS)

Raman, Roger

2003-10-01

Experimental results on the first successful transfer of a Coaxial-Helicity-Injection- (CHI)-produced discharge to inductive operation are reported. CHI assisted plasma start-up is more robust than inductive-only operation and reduces volt-seconds consumption. After hand-off for inductive operation, the initial 100 kA of CHI-produced current drops to 44 kA, then ramps up to 180 kA, using only 30 mVs, more than 30induction alone. Coupling a CHI-produced discharge to induction from a pre-charged central solenoid has produced record plasma currents of 265kA in HIT-II. CHI discharges can also be generated while the central transformer is in the process of being pre-charged, during which period it induces a negative loop voltage on the CHI discharge. Such capability is believed to be important for a short pulse burning plasma experiment that could contain a solenoid. In the latest results, which improve upon the earlier work (Raman et. al., Phys. Rev. Lett., 90, (2003) 075005-1), no transient coil currents are necessary for the CHI produced closed flux generation. This is particularly important for a reactor in which the poloidal field coils would be located outside blanket structures. Three important results are reported. First, CHI is shown to produce closed flux plasma. Second, it is shown that electrode-based CHI plasmas can be sufficiently clean for fusion research purposes. Finally, it is shown that CHI discharges, in addition to generating useful startup current, improve the performance of inductive discharges. This work was motivated by earlier experiments on HIT-II and NSTX that showed coupling of the inductive drive to the external CHI power supply circuit, instead of to the main plasma discharge. These important results were obtained on the HIT-II spherical torus experiment (R/a of 0.3/0.2m, elongation of 1.5).

SILAR deposited Bi2S3 thin film towards electrochemical supercapacitor

NASA Astrophysics Data System (ADS)

Raut, Shrikant S.; Dhobale, Jyotsna A.; Sankapal, Babasaheb R.

2017-03-01

Bi2S3 thin film electrode has been synthesized by simple and low cost successive ionic layer adsorption and reaction (SILAR) method on stainless steel (SS) substrate at room temperature. The formation of interconnected nanoparticles with nanoporous surface morphology has been achieved and which is favourable to the supercapacitor applications. Electrochemical supercapacitive performance of Bi2S3 thin film electrode has been performed through cyclic voltammetry, charge-discharge and stability studies in aqueous Na2SO4 electrolyte. The Bi2S3 thin film electrode exhibits the specific capacitance of 289 Fg-1 at 5 mVs-1 scan rate in 1 M Na2SO4 electrolyte.

In-situ microwave irradiation synthesis of ZnO-graphene nanocomposite for high-performance supercapacitor applications

NASA Astrophysics Data System (ADS)

Gunaseelan, R.; Venkatachalam, V.; Raj, A. Antony

2018-04-01

In this paper, the ZnO/G nanocomposite was synthesized by facile in-situ microwave irradiation method. The as-prepared ZnO/G composite has been characterized with X-ray powder diffraction. The electrochemical properties of the obtained composite electrode for supercapacitor have been studied by cyclic voltammetry and electrochemical impedance spectra analyses. The ZnO/G nanocomposites showed a good capacitive behavior with a higher specific capacitance of 140.4 F/g at a scan rate of 5 mV/s scan rate in 1M KOH electrolyte. Based on the electrochemical results revealed that the composite electrode is a suitable candidate for supercapacitor applications.

Microbial Community Composition and Functional Capacity in a Terrestrial Ferruginous, Sulfate-Depleted Mud Volcano

PubMed Central

Tu, Tzu-Hsuan; Wu, Li-Wei; Lin, Yu-Shih; Imachi, Hiroyuki; Lin, Li-Hung; Wang, Pei-Ling

2017-01-01

Terrestrial mud volcanoes (MVs) are an important natural source of methane emission. The role of microbial processes in methane cycling and organic transformation in such environments remains largely unexplored. In this study, we aim to uncover functional potentials and community assemblages across geochemical transitions in a ferruginous, sulfate-depleted MV of eastern Taiwan. Geochemical profiles combined with 16S rRNA gene abundances indicated that anaerobic oxidation of methane (AOM) mediated by ANME-2a group coincided with iron/manganese reduction by Desulfuromonadales at shallow depths deprived of sulfate. The activity of AOM was stimulated either by methane alone or by methane and a range of electron acceptors, such as sulfate, ferrihydrite, and artificial humic acid. Metagenomic analyses revealed that functional genes for AOM and metal reduction were more abundant at shallow intervals. In particular, genes encoding pili expression and electron transport through multi-heme cytochromes were prevalent, suggesting potential intercellular interactions for electron transport involved in AOM. For comparison, genes responsible for methanogenesis and degradation of chitin and plant-derived molecules were more abundant at depth. The gene distribution combined with the enhanced proportions of 16S rRNA genes related to methanogens and heterotrophs, and geochemical characteristics suggest that particulate organic matter was degraded into various organic entities that could further fuel in situ methanogenesis. Finally, genes responsible for aerobic methane oxidation were more abundant in the bubbling pool and near-surface sediments. These methane oxidizers account for the ultimate attenuation of methane discharge into the atmosphere. Overall, our results demonstrated that various community members were compartmentalized into stratified niches along geochemical gradients. These community members form a metabolic network that cascades the carbon transformation from the upstream degradation of recalcitrant organic carbon with fermentative production of labile organic entities and methane to downstream methane oxidation and metal reduction near the surface. Such a metabolic architecture enables effective methane removal under ferruginous, sulfate-depleted conditions in terrestrial MVs. PMID:29163423

Multivitamin-mineral use is associated with reduced risk of cardiovascular disease mortality among women in the United States.

PubMed

Bailey, Regan L; Fakhouri, Tala H; Park, Yikyung; Dwyer, Johanna T; Thomas, Paul R; Gahche, Jaime J; Miller, Paige E; Dodd, Kevin W; Sempos, Christopher T; Murray, David M

2015-03-01

Multivitamin-mineral (MVM) products are the most commonly used supplements in the United States, followed by multivitamin (MV) products. Two randomized clinical trials (RCTs) did not show an effect of MVMs or MVs on cardiovascular disease (CVD) mortality; however, no clinical trial data are available for women with MVM supplement use and CVD mortality. The objective of this research was to examine the association between MVM and MV use and CVD-specific mortality among US adults without CVD. A nationally representative sample of adults from the restricted data NHANES III (1988-1994; n = 8678; age ≥40 y) were matched with mortality data reported by the National Death Index through 2011 to examine associations between MVM and MV use and CVD mortality by using Cox proportional hazards models, adjusting for multiple potential confounders. We observed no significant association between CVD mortality and users of MVMs or MVs compared with nonusers; however, when users were classified by the reported length of time products were used, a significant association was found with MVM use of >3 y compared with nonusers (HR: 0.65; 95% CI: 0.49, 0.85). This finding was largely driven by the significant association among women (HR: 0.56; 95% CI: 0.37, 0.85) but not men (HR: 0.79; 95% CI: 0.44, 1.42). No significant association was observed for MV products and CVD mortality in fully adjusted models. In this nationally representative data set with detailed information on supplement use and CVD mortality data ∼20 y later, we found an association between MVM use of >3 y and reduced CVD mortality risk for women when models controlled for age, race, education, body mass index, alcohol, aspirin use, serum lipids, blood pressure, and blood glucose/glycated hemoglobin. Our results are consistent with the 1 available RCT in men, indicating no relation with MVM use and CVD mortality. © 2015 American Society for Nutrition.

Genetic variability of wild-type measles viruses, circulating in the Russian Federation during the implementation of the National Measles Elimination Program, 2003-2007.

PubMed

Shulga, S V; Rota, P A; Kremer, J R; Naumova, M A; Muller, C P; Tikhonova, N T; Lopareva, E N; Mamaeva, T A; Tsvirkun, O V; Mulders, M N; Lipskaya, G Y; Gerasimova, A G

2009-06-01

Genetic characterization of wild-type measles viruses (MVs) is an important component of laboratory surveillance of measles. In this study, a phylogenetic analysis was performed of the nucleoprotein gene sequences of 228 MVs isolated in the Russian Federation between 2003 and 2007. Five genotypes, D4, D5, D6, D8, and H1, were detected. From 1999 through the first 6 months of 2003, the most prevalent genotype in the European part of Russia was D4. All genotype D4-type viruses were closely related to each other (with overall sequence diversity of

Microbial Community Composition and Functional Capacity in a Terrestrial Ferruginous, Sulfate-Depleted Mud Volcano.

PubMed

Tu, Tzu-Hsuan; Wu, Li-Wei; Lin, Yu-Shih; Imachi, Hiroyuki; Lin, Li-Hung; Wang, Pei-Ling

2017-01-01

Terrestrial mud volcanoes (MVs) are an important natural source of methane emission. The role of microbial processes in methane cycling and organic transformation in such environments remains largely unexplored. In this study, we aim to uncover functional potentials and community assemblages across geochemical transitions in a ferruginous, sulfate-depleted MV of eastern Taiwan. Geochemical profiles combined with 16S rRNA gene abundances indicated that anaerobic oxidation of methane (AOM) mediated by ANME-2a group coincided with iron/manganese reduction by Desulfuromonadales at shallow depths deprived of sulfate. The activity of AOM was stimulated either by methane alone or by methane and a range of electron acceptors, such as sulfate, ferrihydrite, and artificial humic acid. Metagenomic analyses revealed that functional genes for AOM and metal reduction were more abundant at shallow intervals. In particular, genes encoding pili expression and electron transport through multi-heme cytochromes were prevalent, suggesting potential intercellular interactions for electron transport involved in AOM. For comparison, genes responsible for methanogenesis and degradation of chitin and plant-derived molecules were more abundant at depth. The gene distribution combined with the enhanced proportions of 16S rRNA genes related to methanogens and heterotrophs, and geochemical characteristics suggest that particulate organic matter was degraded into various organic entities that could further fuel in situ methanogenesis. Finally, genes responsible for aerobic methane oxidation were more abundant in the bubbling pool and near-surface sediments. These methane oxidizers account for the ultimate attenuation of methane discharge into the atmosphere. Overall, our results demonstrated that various community members were compartmentalized into stratified niches along geochemical gradients. These community members form a metabolic network that cascades the carbon transformation from the upstream degradation of recalcitrant organic carbon with fermentative production of labile organic entities and methane to downstream methane oxidation and metal reduction near the surface. Such a metabolic architecture enables effective methane removal under ferruginous, sulfate-depleted conditions in terrestrial MVs.

Influence of Solutocapillary Convection on Macrovoid Defect Formation in Polymeric Membranes

NASA Technical Reports Server (NTRS)

Pekny, M. R.; Zartman, J.; Greenberg, A. R.; Todd, P.; Krantz, W. B.

2001-01-01

Macrovoids (MVs) are large (10-50 micrometers) pores often found in polymeric membranes prepared via phase-inversion techniques. They are generally considered undesirable, as they adversely affect the permeability properties and performance of polymeric membranes for microfiltration, ultrafiltration, and reverse osmosis. However, MVs can be useful in certain thin-film applications in which vapor transmission is necessary, or for use as reservoirs for enzymes or liquid membrane material. If more could be learned about the nature and causes of MV formation, it might be possible to devise techniques to control and/or prevent MV formation that are more effective than those currently employed. Two hypotheses for the MV growth mechanism have been advanced. Reuvers proposed that once initiated, MV growth can be attributed to diffusion of (primarily) solvent to the MV nuclei. Because this mechanism does not involve gross movement of the MV, the presence or absence of body forces such as buoyancy should not significantly affect MV growth. On the other hand, Shojaie et al. proposed that solutocapillary convection induced by a steep surface-tension gradient along the MV/bulk solution interface enhances mass transfer to the growing MV. This interfacial convection exerts a force that pulls the growing MV downward into the casting solution. Both buoyancy and viscous drag hinder MV growth by inhibiting this motion. Thus, removing the buoyancy force by casting in microgravity should augment MV growth according to this hypothesis. Whereas neither surface tension nor gravity has a significant effect on MV growth according to the first hypothesis, buoyancy forces should be important if the second hypothesis is correct. The overall goal of this research is to test these two hypotheses in order to improve our understanding of the MV growth processing solvent-cast polymeric membranes. Studying MV growth in low-gravity conditions is pivotal to our ability to discriminate between these two hypotheses.

A randomized controlled trial of pre-procedure simethicone and N-acetylcysteine to improve mucosal visibility during gastroscopy – NICEVIS

PubMed Central

Basford, Peter John; Brown, James; Gadeke, Lisa; Fogg, Carole; Haysom-Newport, Ben; Ogollah, Reuben; Bhattacharyya, Rupam; Longcroft-Wheaton, Gaius; Thursby-Pelham, Fergus; Neale, James R.; Bhandari, Pradeep

2016-01-01

Background and study aims: Mucosal views can be impaired by residual bubbles and mucus during gastroscopy. This study aimed to determine whether a pre-gastroscopy drink containing simethicone and N-acetylcysteine improves mucosal visualisation. Patients and methods: We conducted a randomized controlled trial recruiting 126 subjects undergoing routine gastroscopy. Subjects were randomized 1:1:1 to receive: A—pre-procedure drink of water, simethicone and N-acetylcysteine (NAC); B—water alone; or C—no preparation. Study endoscopists were blinded to group allocation. Digital images were taken at 4 locations (lower esophagus/upper gastric body/antrum/fundus), and rated for mucosal visibility (MV) using a 4-point scale (1 = best, 4 = worst) by 4 separate experienced endoscopists. The primary outcome measure was mean mucosal visibility score (MVS). Secondary outcome measures were procedure duration and volume of fluid flush required to achieve adequate mucosal views. Results: Mean MVS for Group A was significantly better than for Group B (1.35 vs 2.11, P < 0.001) and Group C (1.35 vs 2.21, P < 0.001). Mean flush volume required to achieve adequate mucosal views was significantly lower in Group A than Group B (2.0 mL vs 31.5 mL, P = 0.001) and Group C (2.0 mL vs 39.2 mL P < 0.001). Procedure duration did not differ significantly between any of the 3 groups. MV scores at each of the 4 locations demonstrated significantly better mucosal visibility in Group A compared to Group B and Group C (P < 0.0025 for all comparisons). Conclusions: A pre-procedure drink containing simethicone and NAC significantly improves mucosal visibility during gastroscopy and reduces the need for flushes during the procedure. Effectiveness in the lower esophagus demonstrates potential benefit in Barrett’s oesophagus surveillance gastroscopy. PMID:27853746

A randomized controlled trial of pre-procedure simethicone and N-acetylcysteine to improve mucosal visibility during gastroscopy - NICEVIS.

PubMed

Basford, Peter John; Brown, James; Gadeke, Lisa; Fogg, Carole; Haysom-Newport, Ben; Ogollah, Reuben; Bhattacharyya, Rupam; Longcroft-Wheaton, Gaius; Thursby-Pelham, Fergus; Neale, James R; Bhandari, Pradeep

2016-11-01

Background and study aims: Mucosal views can be impaired by residual bubbles and mucus during gastroscopy. This study aimed to determine whether a pre-gastroscopy drink containing simethicone and N-acetylcysteine improves mucosal visualisation. Patients and methods: We conducted a randomized controlled trial recruiting 126 subjects undergoing routine gastroscopy. Subjects were randomized 1:1:1 to receive: A-pre-procedure drink of water, simethicone and N-acetylcysteine (NAC); B-water alone; or C-no preparation. Study endoscopists were blinded to group allocation. Digital images were taken at 4 locations (lower esophagus/upper gastric body/antrum/fundus), and rated for mucosal visibility (MV) using a 4-point scale (1 = best, 4 = worst) by 4 separate experienced endoscopists. The primary outcome measure was mean mucosal visibility score (MVS). Secondary outcome measures were procedure duration and volume of fluid flush required to achieve adequate mucosal views. Results: Mean MVS for Group A was significantly better than for Group B (1.35 vs 2.11, P  < 0.001) and Group C (1.35 vs 2.21, P  < 0.001). Mean flush volume required to achieve adequate mucosal views was significantly lower in Group A than Group B (2.0 mL vs 31.5 mL, P  = 0.001) and Group C (2.0 mL vs 39.2 mL P  < 0.001). Procedure duration did not differ significantly between any of the 3 groups. MV scores at each of the 4 locations demonstrated significantly better mucosal visibility in Group A compared to Group B and Group C ( P  < 0.0025 for all comparisons). Conclusions: A pre-procedure drink containing simethicone and NAC significantly improves mucosal visibility during gastroscopy and reduces the need for flushes during the procedure. Effectiveness in the lower esophagus demonstrates potential benefit in Barrett's oesophagus surveillance gastroscopy.

Overview of Current Drive Experiment-Upgrade (CDX-U)

NASA Astrophysics Data System (ADS)

Hwang, Y. S.; Choe, W.; Stutman, D.; Lo, E.; Menard, J.; Ono, M.; Jones, T. G.; Armstrong, R.

1996-11-01

The CDX-U tokamak is a spherical tokamak (ST) facility with R ≈ 32 cm, R/a >= 1.4, and B_TF ≈ 1 kG. With an OH power supply of 60 mV-S capability, experiments were conducted with Ip up to ~ 100 kA and q(a) >= 3.5. The ST plasma performance has been studied along with various MHD-related activities. By appropriate discharge programing, it was possible to obtain MHD-quiescent discharges with a factor of 2 - 3 improvement in the electron energy confinement. Recently, the outer vacuum vessel was replaced with a toroidally continuous stainless steel chamber to accomodate the fast wave antenna. With the newly installed antenna, preliminary heating experiments using high harmonic fast waves have been pursued. The success of fast wave heating is a crucial element for achieving high beta plasmas in ST devices such as NSTX. Also, preliminary electron ripple injection (ERI) experiments were performed in CDX-U to examine the feasibility of this technique for improving ST tokamak confinement. To support the ST physics investigation, various novel plasma profile diagnostics such as the multi-pass Thomson scattering, soft x-ray tomography, and tangential-phase-contrast-imaging systems are under development on CDX-U.

Signed, Sealed, Delivered: Microenvironmental Modulation of Extracellular Vesicle-Dependent Immunoregulation in the Lung.

PubMed

Schneider, Daniel J; Speth, Jennifer M; Peters-Golden, Marc

2016-01-01

Unconventional secretion and subsequent uptake of molecular cargo via extracellular vesicles (EVs) is an important mechanism by which cells can exert paracrine effects. While this phenomenon has been widely characterized in the context of their ability to promote inflammation, less is known about the ability of EVs to transfer immunosuppressive cargo. Maintenance of normal physiology in the lung requires suppression of potentially damaging inflammatory responses to the myriad of insults to which it is continually exposed. Recently, our laboratory has reported the ability of alveolar macrophages (AMs) to secrete suppressors of cytokine signaling (SOCS) proteins within microvesicles (MVs) and exosomes (Exos). Uptake of these EVs by alveolar epithelial cells (AECs) resulted in inhibition of pro-inflammatory STAT activation in response to cytokines. Moreover, AM packaging of SOCS within EVs could be rapidly tuned in response to exogenous or AEC-derived substances. In this article we will highlight gaps in knowledge regarding microenvironmental modulation of cargo packaging and utilization as well as EV secretion and uptake. Advances in these areas are critical for improving understanding of intercellular communication in the immune system and for therapeutic application of artificial vesicles aimed at treatment of diseases characterized by dysregulated inflammation.

Signed, Sealed, Delivered: Microenvironmental Modulation of Extracellular Vesicle-Dependent Immunoregulation in the Lung

PubMed Central

Schneider, Daniel J.; Speth, Jennifer M.; Peters-Golden, Marc

2016-01-01

Unconventional secretion and subsequent uptake of molecular cargo via extracellular vesicles (EVs) is an important mechanism by which cells can exert paracrine effects. While this phenomenon has been widely characterized in the context of their ability to promote inflammation, less is known about the ability of EVs to transfer immunosuppressive cargo. Maintenance of normal physiology in the lung requires suppression of potentially damaging inflammatory responses to the myriad of insults to which it is continually exposed. Recently, our laboratory has reported the ability of alveolar macrophages (AMs) to secrete suppressors of cytokine signaling (SOCS) proteins within microvesicles (MVs) and exosomes (Exos). Uptake of these EVs by alveolar epithelial cells (AECs) resulted in inhibition of pro-inflammatory STAT activation in response to cytokines. Moreover, AM packaging of SOCS within EVs could be rapidly tuned in response to exogenous or AEC-derived substances. In this article we will highlight gaps in knowledge regarding microenvironmental modulation of cargo packaging and utilization as well as EV secretion and uptake. Advances in these areas are critical for improving understanding of intercellular communication in the immune system and for therapeutic application of artificial vesicles aimed at treatment of diseases characterized by dysregulated inflammation. PMID:27626032

Redox-Active Star Molecules Incorporating the 4-Benzoylpyridinium Cation - Implications for the Charge Transfer Along Branches vs. Across the Perimeter in Dendrimer

NASA Technical Reports Server (NTRS)

Leventis, Nicholas; Yang, Jinua; Fabrizio,Even F.; Rawashdeh, Abdel-Monem M.; Oh, Woon Su; Sotiriou-Leventis, Chariklia

2004-01-01

Dendrimers are self-repeating globular branched star molecules, whose fractal structure continues to fascinate, challenge, and inspire. Functional dendrimers may incorporate redox centers, and potential applications include antennae molecules for light harvesting, sensors, mediators, and artificial biomolecules. We report the synthesis and redox properties of four star systems incorporating the 4-benzoyl-N-alkylpyridinium cation; the redox potential varies along the branches but remains constant at fixed radii. Bulk electrolysis shows that at a semi-infinite time scale all redox centers are electrochemically accessible. However, voltammetric analysis (cyclic voltammetry and differential pulse voltammetry) shows that on1y two of the three redox-active centers in the perimeter are electrochemically accessible during potential sweeps as slow as 20 mV/s and as fast as 10 V/s. On the contrary, both redox centers along branches are accessible electrochemically within the same time frame. These results are explained in terms of slow through-space charge transfer and the globular 3-D folding of the molecules and are discussed in terms of their implications on the design of efficient redox functional dendrimers.

Resting lymphocyte transduction with measles virus glycoprotein pseudotyped lentiviral vectors relies on CD46 and SLAM

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

Zhou Qi; Schneider, Irene C.; Gallet, Manuela

2011-05-10

The measles virus (MV) glycoproteins hemagglutinin (H) and fusion (F) were recently shown to mediate transduction of resting lymphocytes by lentiviral vectors. MV vaccine strains use CD46 or signaling lymphocyte activation molecule (SLAM) as receptor for cell entry. A panel of H protein mutants derived from vaccine strain or wild-type MVs that lost or gained CD46 or SLAM receptor usage were investigated for their ability to mediate gene transfer into unstimulated T lymphocytes. The results demonstrate that CD46 is sufficient for efficient vector particle association with unstimulated lymphocytes. For stable gene transfer into these cells, however, both MV receptors weremore » found to be essential.« less

Multilayered nano-architecture of variable sized graphene nanosheets for enhanced supercapacitor electrode performance.

PubMed

Biswas, Sanjib; Drzal, Lawrence T

2010-08-01

The diverse physical and chemical aspects of graphene nanosheets such as particle size surface area and edge chemistry were combined to fabricate a new supercapacitor electrode architecture consisting of a highly aligned network of large-sized nanosheets as a series of current collectors within a multilayer configuration of bulk electrode. Capillary driven self-assembly of monolayers of graphene nanosheets was employed to create a flexible, multilayer, free-standing film of highly hydrophobic nanosheets over large macroscopic areas. This nanoarchitecture exhibits a high-frequency capacitative response and a nearly rectangular cyclic voltammogram at 1000 mV/s scanning rate and possesses a rapid current response, small equivalent series resistance (ESR), and fast ionic diffusion for high-power electrical double-layer capacitor (EDLC) application.

Corrosion Properties of SAC305 Solder in Different Solution of HCl and NaCl

NASA Astrophysics Data System (ADS)

Nurwahida, M. Z.; Mukridz, M. M.; Ahmad, A. M.; Muhammad, F. M. N.

2018-03-01

Potentiodynamic polarization was used to studied the corrosion properties of SAC305 solder in different solution of 1.0 M HCl and 3.5 wt.% NaCl using the same scanning rate of 1.0 mV/s. The polarization curves indicated that corrosion in NaCl was less severe than in HCl solution based on corrosion current and passivation behavior obtained. Morphology and phases obtained after corrosion using SEM and XRD were analyzed. Microstructure analysis shows the present of compact corrosion product with presence of larger flake for polarization in NaCl compared to HCl. Phases present in XRD analysis confirmed the present of SnO and SnO2 corrosion product for sample from both solutions.

Low-Temperature-Annealed Reduced Graphene Oxide-Polyaniline Nanocomposites for Supercapacitor Applications

NASA Astrophysics Data System (ADS)

Liao, Chen-Yu; Chien, Hung-Hua; Hao, Yu-Chuan; Chen, Chieh-Wen; Yu, Ing-Song; Chen, Jian-Zhang

2018-04-01

Screen-printed reduced graphene oxide (rGO)-polyaniline (PANI) nanocomposites with/without post-annealing were used as the electrode of a supercapacitor with a polyvinyl alcohol/H2SO4 quasi-solid-state gel electrolyte. Annealing can remove part of the ineffective organic binders and thus enhance the supercapacitive performance. However, too high an annealing temperature may damage PANI, thus reducing the pseudocapacitance. Annealing at 100°C for 10 min results in the best achieved areal capacitance of 102.73 mF/cm2, as evaluated by cyclic voltammetry (CV) under a potential scan rate of 2 mV/s. The capacitance retention rate is 88% after 1000 CV cycles under bending with a bending radius of 0.55 cm.

One-Step Electrochemical Fabrication of Reduced Graphene Oxide/Gold Nanoparticles Nanocomposite-Modified Electrode for Simultaneous Detection of Dopamine, Ascorbic Acid, and Uric Acid

PubMed Central

Lee, Chang-Seuk; Yu, Su Hwan; Kim, Tae Hyun

2017-01-01

Here, we introduce the preparation of the hybrid nanocomposite-modified electrode consisting of reduced graphene oxide (RGO) and gold nanoparticles (AuNPs) using the one-step electrochemical method, allowing for the simultaneous and individual detection of dopamine (DA), ascorbic acid (AA), and uric acid (UA). RGO/AuNPs nanocomposite was formed on a glassy carbon electrode by the co-reduction of GO and Au3+ using the potentiodynamic method. The RGO/AuNPs nanocomposite-modified electrode was produced by subjecting a mixed solution of GO and Au3+ to cyclic sweeping from −1.5 V to 0.8 V (vs. Ag/AgCl) at a scan rate 10 mV/s for 3 cycles. The modified electrode was characterized by scanning electron microscopy, Raman spectroscopy, contact angle measurement, electrochemical impedance spectroscopy, and cyclic voltammetry. Voltammetry results confirm that the RGO/AuNPs nanocomposite-modified electrode has high catalytic activity and good resolution for the detection of DA, AA, and UA. The RGO/AuNPs nanocomposite-modified electrode exhibits stable amperometric responses for DA, AA, and UA, respectively, and its detection limits were estimated to be 0.14, 9.5, and 25 μM. The modified electrode shows high selectivity towards the determination of DA, AA, or UA in the presence of potentially active bioelements. In addition, the resulting sensor exhibits many advantages such as fast amperometric response, excellent operational stability, and appropriate practicality. PMID:29301209

A 176×144 148dB adaptive tone-mapping imager

NASA Astrophysics Data System (ADS)

Vargas-Sierra, S.; Liñán-Cembrano, G.; Rodríguez-Vázquez, A.

2012-03-01

This paper presents a 176x144 (QCIF) HDR image sensor where visual information is simultaneously captured and adaptively compressed by means of an in-pixel tone mapping scheme. The tone mapping curve (TMC) is calculated from the histogram of a Time Stamp image captured in the previous frame, which serves as a probability indicator of the distribution of illuminations within the present frame. The chip produces 7-bit/pixel images that can map illuminations from 311μlux to 55.3 klux in a single frame in a way that each pixel decides when to stop observing photocurrent integration -with extreme values captured at 8s and 2.34μs respectively. Pixels size is 33x33μm2, which includes a 3x3μm2 Nwell- Psubstrate photodiode and an autozeroing technique for establishing the reset voltage, which cancels most of the offset contributions created by the analog processing circuitry. Dark signal (10.8 mV/s ) effects in the final image are attenuated by an automatic programming of the DAC top voltage. Measured characteristics are Sensitivity 5.79 V/lux.s , FWC 12.2ke-, Conversion Factor 129(e-/DN), and Read Noise 25e-. The chip has been designed in the 0.35μm OPTO technology from Austriamicrosystems (AMS). Due to the focal plane operation, this architecture is especially well suited to be implemented in a 3D (vertical stacking) technology using per-pixel TSVs.

Endoscopic laser-urethroplasty

NASA Astrophysics Data System (ADS)

Gilbert, Peter

2006-02-01

The objective was to prove the advantage of endoscopic laser-urethroplasty over internal urethrotomy in acquired urethral strictures. Patients and Method: From January, 1996 to June, 2005, 35 patients with a mean age of 66 years were submitted to endoscopic laser-urethroplasty for strictures of either the bulbar (30) or membranous (5) urethra. The operations were carried out under general anesthesia. First of all, the strictures were incised at the 4, 8 and 12 o'clock position by means of a Sachse-urethrotom. Then the scar flap between the 4 and 8 o'clock position was vaporized using a Nd:YAG laser, wavelength 1060 nm and a 600 pm bare fiber, the latter always being in contact with the tissue. The laser worked at 40W power in continuous mode. The total energy averaged 2574 J. An indwelling catheter was kept in place overnight and the patients were discharged the following day. Urinalysis, uroflowmetry and clinical examination were performed at two months after surgery and from then on every six months. Results: No serious complications were encountered. Considering a mean follow-up of 18 months, the average peak flow improved from 7.3 ml/s preoperatively to 18.7 mVs postoperatively. The treatment faded in 5 patients ( 14.3% ) who finally underwent open urethroplasty. Conclusions: Endoscopic laser-urethroplasty yields better short-term results than internal visual urethrotomy. Long-term follow-up has yet to confirm its superiority in the treatment of acquired urethral strictures.

Spatiotemporal Characteristics of QRS Complexes Enable the Diagnosis of Brugada Syndrome Regardless of the Appearance of a Type 1 ECG.

PubMed

Guillem, Maria S; Climent, Andreu M; Millet, José; Berne, Paola; Ramos, Rafael; Brugada, Josep; Brugada, Ramon

2016-05-01

The diagnosis of Brugada syndrome based on the ECG is hampered by the dynamic nature of its ECG manifestations. Brugada syndrome patients are only 25% likely to present a type 1 ECG. The objective of this study is to provide an ECG diagnostic criterion for Brugada syndrome patients that can be applied consistently even in the absence of a type 1 ECG. We recorded 67-lead body surface potential maps from 94 Brugada syndrome patients and 82 controls (including right bundle branch block patients and healthy individuals). The spatial propagation direction during the last r' wave and the slope at the end of the QRS complex were measured and compared between patients groups. Receiver-operating characteristic curves were constructed for half of the database to identify optimal cutoff values; sensitivity and specificity for these cutoff values were measured in the other half of the database. A spontaneous type 1 ECG was present in only 30% of BrS patients. An orientation in the sagittal plane < 101º during the last r' wave and a descending slope < 9.65 mV/s enables the diagnosis of the syndrome with a sensitivity of 69% and a specificity of 97% in non-type 1 Brugada syndrome patients. Spatiotemporal characteristics of surface ECG recordings can enable a robust identification of BrS even without the presence of a type 1 ECG. © 2016 Wiley Periodicals, Inc.

Flexible carbon micro-supercapacitors prepared by direct cw-laser writing

NASA Astrophysics Data System (ADS)

Cai, Jinguang; Watanabe, Akira

2016-03-01

Micro-/nano-scale power supply units with high energy and high power densities are critical components for the development of compact miniaturized portable electronic devices. Supercapacitors have attracted many research attentions due to their high power density, robust cycle performance, pollution-free operation, and maintenance-free features. Besides, the properties of small size, light weight, and flexibility are also required. On-chip microsupercapacitors (MSCs) have the potential acting as power supply units in portable devices, due to their simplified packaging processes and compatibility to the integrated circuits. However, the fabrication methods and materials should be cost-effective, scalable, and compatible to current electronic industry. Carbon materials own high specific surface areas, electrochemical stability, and high electrical conductivity, which are critical parameters for high-power supercapacitors. Moreover, the high mechanical tolerance makes them good candidates for flexible wearable devices. Therefore, MSCs based on carbon materials would satisfy the requirements of portable electronics. In this work, we demonstrated the fabrication of carbon MSCs by laser direct writing on commercial polyimide sheets in Ar with lowcost semiconductor cw-laser with a wavelength of 405nm. The obtained structures are macro-nanostructures comprising graphitized and amorphous carbon with relatively smooth surfaces and low resistance, in compared with the structures obtained by laser writing in air. As-prepared micro-supercapacitors show a high capacitance of about 14.9 mF/cm2 at a scanning rate of 10 mV/s, which is comparable to the reported highest capacitance of carbon-based supercapacitors fabricated by pulse-laser writing.

Evaluation by the Double Loop Electrochemical Potentiokinetic Reactivation Test of Aged Ferritic Stainless Steel Intergranular Corrosion Susceptibility

NASA Astrophysics Data System (ADS)

Sidhom, H.; Amadou, T.; Braham, C.

2010-12-01

An experimental design method was used to determine the effect of factors that significantly affect the response of the double loop-electrochemical potentiokinetic reactivation (DL-EPR) test in controlling the susceptibility to intergranular corrosion (IGC) of UNS S43000 (AISI 430) ferritic stainless steel. The test response is expressed in terms of the reactivation/activation current ratio ( I r / I a pct). Test results analysed by the analysis of variance (ANOVA) method show that the molarity of the H2SO4 electrolyte and the potential scanning rate have a more significant effect on the DL-EPR test response than the temperature and the depassivator agent concentration. On the basis of these results, a study was conducted in order to determine the optimal operating conditions of the test as a nondestructive technique for evaluating IGC resistance of ferritic stainless steel components. Three different heat treatments are considered in this study: solution annealing (nonsensitized), aging during 3 hours at 773 K (500 °C) (slightly sensitized), and aging during 2 hours at 873 K (600 °C) (highly sensitized). The aim is to find the operating conditions that simultaneously ensure the selectivity of the attack (intergranular and chromium depleted zone) and are able to detect the effect of low dechromization. It is found that a potential scanning rate of 2.5 mV/s in an electrolyte composed of H2SO4 3 M solution without depassivator, at a temperature around 293 K (20 °C), is the optimal operating condition for the DL-EPR test. Using this condition, it is possible to assess the degree of sensitization (DOS) to the IGC of products manufactured in ferritic stainless steels rapidly, reliably, and quantitatively. A time-temperature-start of sensitization (TTS) diagram for the UNS S43000 (France Inox, Villepinte, France) stainless steel was obtained with acceptable accuracy by this method when the IGC sensitization criterion was set to I r / I a > 1 pct. This diagram is in good agreement with the time-temperature-start of precipitation (TTP) diagram that delineates the domain of low dechromization consecutive to chromium carbide precipitation.

Design, Fabrication, and Characterization of Hematite (α-Fe2O3) Nanostructures

NASA Astrophysics Data System (ADS)

Jansi Rani, B.; Mageswari, R.; Ravi, G.; Ganesh, V.; Yuvakkumar, R.

2017-12-01

The influence of processing parameters on the physicochemical properties of hematite α-Fe2O3 nanostructures was investigated. X-ray diffraction results revealed the hematite phase rhombohedral structure. Scanning electron microscope results explored nanospheres, nanohexagonal platelets, nanoellipsoids, distorted nanocubes, and interconnected platelets nanostructures. Rhombohedral single-phase hematite was confirmed through five Raman active modes. 2 P 3/2 (1) → 2 P 1/2 transition in photoluminescence spectra and Fourier-transform infrared spectroscopy band observed at 555 cm-1 revealed the hematite formation. The highest specific capacitance value of 151.09 F/g for scan rate of 10 mV/s was obtained for the hydrothermal-assisted product using an Fe(NO3)2·9H2O precursor in KOH electrolyte solutions.

Role of annealing duration on the microstructure and electrochemical performance of β-V2O5 thin films

NASA Astrophysics Data System (ADS)

Jeyalakshmi, K.; Muralidharan, G.

2014-03-01

Vanadium pentoxide thin films have been prepared by sol-gel spin coating method. The eight-layered films coated on fluorine-doped tin oxide substrate and glass substrate were subjected to different durations of annealing under a constant annealing temperature of 300 °C from 30 to 120 min. The X-ray diffraction spectrum reveals crystallinity along (2 0 0) direction. The SEM images of these films show the variation in the surface morphology with increase in annealing duration. The supercapacitor behaviour has been studied using cyclic voltammetry technique and electrochemical impedance spectroscopy. The film annealed for 60 min exhibits a maximum specific capacitance of 346 F/g at a scan rate of 5 mV/s with a charge transfer resistance of 172 Ω.

High-performance solid-state supercapacitors based on graphene-ZnO hybrid nanocomposites

NASA Astrophysics Data System (ADS)

Li, Zijiong; Zhou, Zhihua; Yun, Gaoqian; Shi, Kai; Lv, Xiaowei; Yang, Baocheng

2013-11-01

In this paper, we report a facile low-cost synthesis of the graphene-ZnO hybrid nanocomposites for solid-state supercapacitors. Structural analysis revealed a homogeneous distribution of ZnO nanorods that are inserted in graphene nanosheets, forming a sandwiched architecture. The material exhibited a high specific capacitance of 156 F g-1 at a scan rate of 5 mV.s-1. The fabricated solid-state supercapacitor device using these graphene-ZnO hybrid nanocomposites exhibits good supercapacitive performance and long-term cycle stability. The improved supercapacitance property of these materials could be ascribed to the increased conductivity of ZnO and better utilization of graphene. These results demonstrate the potential of the graphene-ZnO hybrid nanocomposites as an electrode in high-performance supercapacitors.

Crosslinked Carbon Nanotubes/Polyaniline Composites as a Pseudocapacitive Material with High Cycling Stability

PubMed Central

Liu, Dong; Wang, Xue; Deng, Jinxing; Zhou, Chenglong; Guo, Jinshan; Liu, Peng

2015-01-01

The poor cycling stability of polyaniline (PANI) limits its practical application as a pseudocapacitive material due to the volume change during the charge-discharge procedure. Herein, crosslinked carbon nanotubes/polyaniline (C-CNTs/PANI) composites had been designed by the in situ chemical oxidative polymerization of aniline in the presence of crosslinked carbon nanotubes (C-CNTs), which were obtained by coupling of the functionalized carbon nanotubes with 1,4-benzoquinone. The composite showed a specific capacitance of 294 F/g at the scan rate of 10 mV/s, and could retain 95% of its initial specific capacitance after 1000 CV cycles. Such high electrochemical cycling stability resulting from the crosslinked skeleton of the C-CNTs makes them potential electrode materials for a supercapacitor. PMID:28347050

Lignin-based Biochar/graphene Oxide Composites as Supercapacitor Electrode Materials

NASA Astrophysics Data System (ADS)

Cai, Z.; Jiang, C.; Xiao, X. F.; Zhang, Y. S.; Liang, L.

2018-05-01

The lignin-based biochar/graphene composites were effectively obtained via an easy and rapid co-precipitation method. The chemical structure, microstructure, electrochemical properties of lignin/graphene oxide composites before and after carbonization were investigated by Fourier transformation infrared spectrum (FTIR), Scanning electron microscope (SEM), x-ray diffraction (XRD) and cyclic voltammetry (CV). FTIR results confirmed that the oxygen-containing groups of lignin, GO and their composites were partly removed after 800 °C carbonization and GO had a positive impact on the formation of graphitic structure for lignin. XRD results showed that lignin could completely block the restacking of GO sheets. The electrochemical test presented that lignin/graphene oxide composites exhibited a typical CV curve and the specific capacitance reached ∼103F/g at a scan rate of 20mv/s.

Nanotubular polyaniline electrode for supercapacitor application

NASA Astrophysics Data System (ADS)

Athira, A. R.; Vimuna, V. M.; Vidya, K.; Xavier, T. S.

2018-05-01

Polyaniline(PANI) nanotubes have been successfully synthesised at room temperature by the chemical oxidative polymerization of aniline with Ammoniumpersulphate(APS) in aqueous acetic acid. Chemically synthesised PANI nanotubes were characterized using Field emission scanning electron microscopy(FESEM), Brunauer - Emmett-Teller (BET) analysis, X ray diffraction analysis (XRD) and Fourier transform infrared spectroscopy (FTIR). The super capacitive performance of the synthesised PANI nanotubes was tested using cyclic voltammetry (CV) technique in H2SO4 electrolyte with in potential range of -0.2 to 0.8V. The effect of scan rates on specific capacitance of PANI electrode was studied. The highest specific capacitance of 232.2Fg-1 was obtained for the scan rate of 5mVs-1. This study suggests that the synthesized PANI nanotubes are excellent candidate for developing electrode materials for supercapacitors.

A Facile Synthesis of a Palladium-Doped Polyaniline-Modified Carbon Nanotube Composites for Supercapacitors

NASA Astrophysics Data System (ADS)

Giri, Soumen; Ghosh, Debasis; Malas, Asish; Das, Chapal Kumar

2013-08-01

Supercapacitors have evolved as the premier choice of the era for storing huge amounts of charge in the field of energy storage devices, but it is still necessary to enhance their performance to meet the increasing requirements of future systems. This could be achieved either through advancing the interfaces of the material at the nanoscale or by using novel material compositions. We report a high-performance material composition prepared by combining a transition metal (palladium)-doped conductive polymer with multiwalled carbon nanotubes (MWCNTs). MWCNTs/palladium-doped polyaniline (MWCNTs/Pd/PANI) composites and multiwalled carbon nanotube/polyaniline (MWCNTs/PANI) composites (for comparison) were prepared via in situ oxidative polymerization of aniline monomer. The reported composites were characterized by Fourier-transform infrared (FTIR), x-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), and transmission electron microscopy (TEM) studies. FESEM and TEM studies indicated the narrow size distribution of the π-conjugated polymer-protected palladium nanoparticles on the surface of the carbon nanotubes. All the electrochemical characterizations were executed using a three-electrode system in 1 M H2SO4 electrolyte. Cyclic voltammetry (CV) analysis was performed to observe the capacitive performance and redox behavior of the composites. The ion transfer behavior and cyclic stability of the composites were investigated by electrochemical impedance spectroscopy (EIS) analysis and cyclic charge-discharge (CCD) testing, respectively. The MWCNTs/Pd/PANI composite was found to exhibit an especially high specific capacitance value of 920 F/g at scan rate of 2 mV/s.

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

Betancourt, Luis E.; Guzman-Blas, Rolando; Luo, Si

A robust electrodeposition method consisting of the rotating disk slurry electrode (RoDSE) technique to obtain Au nanoparticles highly dispersed on a conductive carbonaceous support, i.e., Vulcan XC-72R, for ethanol electrooxidation reaction in alkaline media was developed. Ceria was used as a cocatalyst using a Ce(III)-EDTA impregnation method in order to enhance the catalytic activity and improve the catalyst’s overall stability. Furthermore, the RoDSE method used to obtain highly dispersed Au nanoparticles does not require the use of a reducing agent or stabilizing agent, and the noble-metal loading was controlled by the addition and tuning of the metal precursor concentration. Inductivelymore » coupled plasma and thermogravimetric analysis indicated that the Au loading in the catalyst was 9 %. We determined the particle size and characteristic Au fcc crystal facets by X-ray diffraction. The morphology of the catalyst was also investigated using electron microscopy techniques. In addition, X-ray absorption spectroscopy was used to corroborate the presence and identify the oxidation state of Ce in the system and to observe if there are any electronic interactions within the 8 % Au/CeO x/C system. Cyclic voltammetry of electrodeposited 9 % Au/C and Ce-promoted 8 % Au/C showed a higher catalytic current density for ethanol oxidation when compared with commercially available catalysts (20 % Au/C) of a higher precious metal loading. Additionally, we report a higher stability toward the ethanol electrooxidation process, which was corroborated by 1 mV/s linear sweep voltammetry and chronoamperometric studies.« less

Image-Based Modeling Techniques for Architectural Heritage 3d Digitalization: Limits and Potentialities

NASA Astrophysics Data System (ADS)

Santagati, C.; Inzerillo, L.; Di Paola, F.

2013-07-01

3D reconstruction from images has undergone a revolution in the last few years. Computer vision techniques use photographs from data set collection to rapidly build detailed 3D models. The simultaneous applications of different algorithms (MVS), the different techniques of image matching, feature extracting and mesh optimization are inside an active field of research in computer vision. The results are promising: the obtained models are beginning to challenge the precision of laser-based reconstructions. Among all the possibilities we can mainly distinguish desktop and web-based packages. Those last ones offer the opportunity to exploit the power of cloud computing in order to carry out a semi-automatic data processing, thus allowing the user to fulfill other tasks on its computer; whereas desktop systems employ too much processing time and hard heavy approaches. Computer vision researchers have explored many applications to verify the visual accuracy of 3D model but the approaches to verify metric accuracy are few and no one is on Autodesk 123D Catch applied on Architectural Heritage Documentation. Our approach to this challenging problem is to compare the 3Dmodels by Autodesk 123D Catch and 3D models by terrestrial LIDAR considering different object size, from the detail (capitals, moldings, bases) to large scale buildings for practitioner purpose.

Avoiding Resistance Limitations in High-Performance Transparent Supercapacitor Electrodes Based on Large-Area, High-Conductivity PEDOT:PSS Films.

PubMed

Higgins, Thomas M; Coleman, Jonathan N

2015-08-05

This work describes the potential of thin, spray-deposited, large-area poly(3,4-ethylenedioxythiophene)/poly(styrene-4-sulfonate) ( PSS) conducting polymer films for use as transparent supercapacitor electrodes. To facilitate this, we provide a detailed explanation of the factors limiting the performance of such electrodes. These films have a very low optical conductivity of σop = 24 S/cm (at 550 nm), crucial for this application, and a reasonable volumetric capacitance of CV = 41 F/cm(3). Secondary doping with formic acid gives these films a DC conductivity of σDC = 936 S/cm, allowing them to perform both as a transparent conductor/current collector and transparent supercapacitor electrode. Small-area films (A ∼ 1 cm(2)) display measured areal capacitance as high as 1 mF/cm(2), even for reasonably transparent electrodes (T ∼ 80%). However, in real devices, the absolute capacitance will be maximized by increasing the device area. As such, here, we measure the electrode performance as a function of its length and width. We find that the measured areal capacitance falls dramatically with scan rate and sample length but is independent of width. We show that this is because the measured areal capacitance is limited by the electrical resistance of the electrode. We have derived an equation for the measured areal capacitance as a function of scan rate and electrode lateral dimensions that fits the data extremely well up to scan rates of ∼1000 mV/s (corresponding to charge/discharge times > 0.6 s). These results are self-consistent with independent analysis of the electrical and impedance properties of the electrodes. These results can be used to find limiting combinations of electrode length and scan rate, beyond which electrode performance falls dramatically. We use these insights to build large-area (∼100 cm(2)) supercapacitors using electrodes that are 95% transparent, providing a capacitance of ∼12 mF (at 50 mV/s), significantly higher than that of any previously reported transparent supercapacitor.

Terrestrial multi-view photogrammetry for landslide monitoring

NASA Astrophysics Data System (ADS)

Stumpf, A.; Malet, J.; Allemand, P.; Skupinski, G.; Pierrot-Deseilligny, M.

2013-12-01

Multi-view stereo (MVS) surface reconstruction from large photo collections is being increasingly used for geoscience applications, and a number of different software solution and processing streamlines have been suggested. Open source libraries to perform feature point extraction, pose estimation, bundle adjustment and dense matching are available providing high quality results at low costs, and transparency of the implemented algorithms. Within the computer vision community benchmark datasets with toy examples and architectural scenes are frequently used to evaluate dense matching algorithms but relatively few studies have addressed the evaluation of complete processing pipelines for complex natural landscapes such as landslides developed in high mountain terrains. In order to obtain surface displacement maps of an active landslide (Super-Sauze, Southern French Alps) from multi-temporal terrestrial photographs over a period of three years, this work targeted the evaluation of three different non-commercial processing pipelines. The tested packages include VisualSfM[1], CMVS-PMVS [2], Apero and MicMac [URL]. The image acquisition focused on either subparts of the landslide (toe, main scarp) or targeted the reconstruction of a global model of the entire landslide. All images were processed with three different pipelines namely VisualSfM + CMVS-PMVS, Apero + CMVS-PMVS and Apero + MicMac and the resulting point clouds were evaluated with terrestrial and airborne LiDAR. Our results show that all multi-view stereo pipelines provide useful results to quantify surface displacement at accuracies between 1-10 cm depending on the acquisition geometry and the object distance. For pose estimation and bundle adjustment, Apero is the more accurate and versatile tool allowing the use of more sophisticated lens models and the direct integration of ground control points in the bundle adjustment. The dense matching algorithms with MicMac enables the reconstruction of denser point clouds, with fewer outliers, better spatial coverage and at lower computational costs, whereas CMVS-PMVS requires less manual tuning and produces fewer artifacts at discontinuities and areas with very low incidence angles. Change detection among the multi-temporal photogrammetric point clouds allowed to measure surface displacement rates greater than 1 m.yr-1 at the landslide toe, and greater than 3 m.yr-1 in the upper most active landslide part, indicating and important mass-accumulation in the central part. Large low frequency rockfall dominate the mass wasting process at the main scarp when compared to erosive retrogression. The study demonstrates that MVS has a great potential to replace LiDAR surveys for operational landslide monitoring providing comparable accuracies at significantly lower logistic and material costs. However, an optimal acquisition geometry and parameterization of the processing algorithms are important factors for its successful application and some recommendations, potential pitfalls and limitations are highlighted. [1] C. Wu, Towards Linear-time Incremental Structure from Motion, Internat. Conf. on 3D Vision, University of Washington, Seattle, USA, 2013. [2] Y. Furukawa and J. Ponce, "Accurate, Dense, and Robust Multiview Stereopsis," Pattern Analysis and Machine Intelligence, IEEE Transactions on, 32, pp. 1362-1376, 2010.

Application of quality by design concept to develop a dual gradient elution stability-indicating method for cloxacillin forced degradation studies using combined mixture-process variable models.

PubMed

Zhang, Xia; Hu, Changqin

2017-09-08

Penicillins are typical of complex ionic samples which likely contain large number of degradation-related impurities (DRIs) with different polarities and charge properties. It is often a challenge to develop selective and robust high performance liquid chromatography (HPLC) methods for the efficient separation of all DRIs. In this study, an analytical quality by design (AQbD) approach was proposed for stability-indicating method development of cloxacillin. The structures, retention and UV characteristics rules of penicillins and their impurities were summarized and served as useful prior knowledge. Through quality risk assessment and screen design, 3 critical process parameters (CPPs) were defined, including 2 mixture variables (MVs) and 1 process variable (PV). A combined mixture-process variable (MPV) design was conducted to evaluate the 3 CPPs simultaneously and a response surface methodology (RSM) was used to achieve the optimal experiment parameters. A dual gradient elution was performed to change buffer pH, mobile-phase type and strength simultaneously. The design spaces (DSs) was evaluated using Monte Carlo simulation to give their possibility of meeting the specifications of CQAs. A Plackett-Burman design was performed to test the robustness around the working points and to decide the normal operating ranges (NORs). Finally, validation was performed following International Conference on Harmonisation (ICH) guidelines. To our knowledge, this is the first study of using MPV design and dual gradient elution to develop HPLC methods and improve separations for complex ionic samples. Copyright © 2017 Elsevier B.V. All rights reserved.

An improved amperometric L-lactate biosensor based on covalent immobilization of microbial lactate oxidase onto carboxylated multiwalled carbon nanotubes/copper nanoparticles/polyaniline modified pencil graphite electrode.

PubMed

Dagar, Kusum; Pundir, C S

2017-01-01

An improved amperometric l-lactate biosensor was constructed based on covalent immobilization of lactate oxidase (LOx) from Pediococcus species onto carboxylated multiwalled carbon nanotubes (cMWCNT)/copper nanoparticles (CuNPs)/polyaniline (PANI) hybrid film electrodeposited on the surface of a pencil graphite electrode (PGE). The enzyme electrode was characterized by cyclic voltammetry (CV), scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy and electrochemical impedance spectroscopy (EIS), while CuNPs synthesized by chemical reduction method, were characterized by transmission electron microscopy (TEM), UV spectrascopy and X-ray diffraction (XRD). The biosensor showed maximum response within 5s at pH 8.0 in 0.05M sodium phosphate buffer and 37°C, when operated at 20mVs -1 . The biosensor had a detection limit of 0.25μM with a wide working range between 1μM-2500μM. The biosensor was employed for measurement of l-lactic acid level in plasma of apparently healthy and diseased persons. Analytical recovery of added lactic acid in plasma was 95.5%. Within- and between-batch coefficients of variations were 6.24% and 4.19% respectively. There was a good correlation (R 2 =0.97) between plasma lactate values as measured by standard enzymatic spectrophotometric method and the present biosensor. The working enzyme electrode was used 180 times over a period of 140 days, when stored at 4°C. Copyright © 2016. Published by Elsevier Inc.

Graphene/Poly(aniline-co-pyrrole) Nanocomposite: Potential Candidate for Supercapacitor and Microwave Absorbing Applications.

PubMed

Sahoo, Sumanta; Bhattacharya, Pallab; Dhibar, Saptarshi; Hatui, Goutam; Das, Tanya; Das, Chapal Kumar

2015-09-01

A simple and cost-effective in-situ chemical route to prepare the nanocomposites based on graphene and Poly(aniline-co-pyrrole) [PPP] has been proposed. Introduction of graphene changes the morphology of copolymer from spherical to fiber like. Graphene/Poly(aniline-co-pyrrole) [GPPP] nanocomposite achieved highest specific capacitance of 351 F/g and energy density of 124.8 Wh/Kg at 10 mV/s scan rate. The composite also obtained moderate specific capacitance retention of 66% after 500 cycles, which establish its potentiality as supercapacitor electrode materials. The composite also exhibited high electrical conductivity and superior microwave absorbing properties (maximum reflection loss is -29.97 dB). The absorption range corresponding to ≥ 90% absorption (or -10 dB) is 2.72 GHz which is excellent for the microwave absorbing applications.

Wet Chemical Synthesis of SnS/Graphene Nanocomposites for High Performance Supercapacitor Electrodes

NASA Astrophysics Data System (ADS)

Ravuri, Syamsai; Pandey, Chandan Abhishek; Ramchandran, R.; Jeon, Soon Kwan; Grace, Andrews Nirmala

A series of SnS/Graphene (SnS/G) nanocomposites at various concentrations of graphene were synthesized by a wet chemical route and the prepared composites were analyzed by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), High Resolution Transmission Electron Microscopy (HRTEM) for its structural and morphological investigation. Results show that the prepared SnS nanoparticles in the composite are ˜30nm sized and uniformly dispersed on graphene sheets. To test the supercapacitance behavior, electrochemical measurements were carried out in 6M KOH electrolyte. A maximum specific capacitance of 984F/g was observed for SnS/G-c at 5mVs-1 scan rate. Galvanostatic charge/discharge curves showed an excellent cyclic stability with higher charge/discharge duration, and hence could be used for high performance supercapacitor applications.

MnO2-Graphene Oxide-PEDOT:PSS Nanocomposite for an Electrochemical Supercapacitor

NASA Astrophysics Data System (ADS)

Patil, Dipali S.; Pawar, Sachin A.; Shin, Jae Cheol; Kim, Hyo Jin

2018-04-01

A ternary nanocomposite with poly (3,4 ethylene dioxythiophene:poly(styrene sulfonate) (PEDOT:PSS)-MnO2 nanowires-graphene oxide (PMn-GO) was synthesized by using simple chemical route. The formation of the nanocomposite was analyzed by using X-ray diffraction and X-ray photoelectron spectroscopy. Field-emission scanning microscopy (FESEM) revealed the formation of MnO2 nanowires and graphene oxide nanosheets. The highest specific capacitance (areal capacitance) of 841 Fg -1 (177 mFcm -2) at 10 mVs -1 and energy density of 0.593 kWhkg -1 at 0.5 mA were observed for PMn-GO, indicating a constructive synergistic effect of PEDOT:PSS, MnO2 nanowires and graphene oxide. The achieved promising electrochemical characteristics showed that this ternary nanocomposite is a good alternative as an electrode material for supercapacitor.

Space tug geosynchronous mission simulation

NASA Technical Reports Server (NTRS)

Lang, T. J.

1973-01-01

Near-optimal three dimensional trajectories from a low earth park orbit inclined at 28.5 deg to a synchronous-equatorial mission orbit were developed for both the storable (thrust = 28,912 N (6,500 lbs), I sub sp = 339 sec) and cryogenic (thrust = 44,480 N (10,000 lbs), I sub sp = 470 sec) space tug using the iterative cost function minimization technique contained within the modularized vehicle simulation (MVS) program. The finite burn times, due to low thrust-to-weight ratios, and the associated gravity losses are accounted for in the trajectory simulation and optimization. The use of an ascent phasing orbit to achieve burnout in synchronous orbit at any longitude is investigated. The ascent phasing orbit is found to offer the additional advantage of significantly reducing the overall delta velocity by splitting the low altitude burn into two parts and thereby reducing gravity losses.

Cloak and Dagger: Alternative Immune Evasion and Modulation Strategies of Poxviruses

PubMed Central

Bidgood, Susanna R.; Mercer, Jason

2015-01-01

As all viruses rely on cellular factors throughout their replication cycle, to be successful they must evolve strategies to evade and/or manipulate the defence mechanisms employed by the host cell. In addition to their expression of a wide array of host modulatory factors, several recent studies have suggested that poxviruses may have evolved unique mechanisms to shunt or evade host detection. These potential mechanisms include mimicry of apoptotic bodies by mature virions (MVs), the use of viral sub-structures termed lateral bodies for the packaging and delivery of host modulators, and the formation of a second, “cloaked” form of infectious extracellular virus (EVs). Here we discuss these various strategies and how they may facilitate poxvirus immune evasion. Finally we propose a model for the exploitation of the cellular exosome pathway for the formation of EVs. PMID:26308043

The Structure of the Chinese Material Value Scale: An Eastern Cultural View

PubMed Central

Liao, Jiangqun; Wang, Lei

2017-01-01

This study investigated the structure of the Chinese Material Value Scale (MVS). A two-factor structure, rather than the original three-factor structure, was proposed for China by means of confirmatory factor analysis. Direct evidence showed that the dimensions of success and happiness could be merged together. Both explicit and implicit methods were used to examine the relationship between success and happiness based on possession. In particular, as an implicit method, the dot-probe paradigm recording participants’ response time supported the idea that the two-factors could be merged together. The results also showed that for Chinese people, success to an extent means happiness, while the converse is not necessarily true. Chinese are much more concerned about social evaluation than their own feelings, and this cultural characteristic is reflected in our findings. PMID:29163258

Diazonium-functionalized horseradish peroxidase immobilized via addressable electrodeposition: direct electron transfer and electrochemical detection.

PubMed

Polsky, Ronen; Harper, Jason C; Dirk, Shawn M; Arango, Dulce C; Wheeler, David R; Brozik, Susan M

2007-01-16

A simple one-step procedure is introduced for the preparation of diazonium-enzyme adducts. The direct electrically addressable deposition of diazonium-modified enzymes is examined for electrochemical sensor applications. The deposition of diazonium-horseradish peroxidase leads to the direct electron transfer between the enzyme and electrode exhibiting a heterogeneous rate constant, ks, of 10.3 +/- 0.7 s-1 and a DeltaEp of 8 mV (v = 150 mV/s). The large ks and low DeltaEp are attributed to the intimate contact between enzyme and electrode attached by one to three phenyl molecules. Such an electrode shows high nonmediated catalytic activity toward H2O2 reduction. Future generations of arrayed electrochemical sensors and studies of direct electron transfer of enzymes can benefit from protein electrodes prepared by this method.

Rotating Disk Slurry Au Electrodeposition at Unsupported Carbon Vulcan XC-72 and Ce 3+ Impregnation for Ethanol Oxidation in Alkaline Media

DOE PAGES

Betancourt, Luis E.; Guzman-Blas, Rolando; Luo, Si; ...

2016-11-19

A robust electrodeposition method consisting of the rotating disk slurry electrode (RoDSE) technique to obtain Au nanoparticles highly dispersed on a conductive carbonaceous support, i.e., Vulcan XC-72R, for ethanol electrooxidation reaction in alkaline media was developed. Ceria was used as a cocatalyst using a Ce(III)-EDTA impregnation method in order to enhance the catalytic activity and improve the catalyst’s overall stability. Furthermore, the RoDSE method used to obtain highly dispersed Au nanoparticles does not require the use of a reducing agent or stabilizing agent, and the noble-metal loading was controlled by the addition and tuning of the metal precursor concentration. Inductivelymore » coupled plasma and thermogravimetric analysis indicated that the Au loading in the catalyst was 9 %. We determined the particle size and characteristic Au fcc crystal facets by X-ray diffraction. The morphology of the catalyst was also investigated using electron microscopy techniques. In addition, X-ray absorption spectroscopy was used to corroborate the presence and identify the oxidation state of Ce in the system and to observe if there are any electronic interactions within the 8 % Au/CeO x/C system. Cyclic voltammetry of electrodeposited 9 % Au/C and Ce-promoted 8 % Au/C showed a higher catalytic current density for ethanol oxidation when compared with commercially available catalysts (20 % Au/C) of a higher precious metal loading. Additionally, we report a higher stability toward the ethanol electrooxidation process, which was corroborated by 1 mV/s linear sweep voltammetry and chronoamperometric studies.« less

An Introduced Hybrid Graphene/Polyaniline Composites for Improvement of Supercapacitor

NASA Astrophysics Data System (ADS)

Tayel, Mazhar B.; Soliman, Moataz M.; Ebrahim, Shaker; Harb, Mohamed E.

2016-01-01

Supercapacitors represent an attractive alternative for portable electronics and automotive applications due to their high capacitance, specific power and extended life. In fact, the growing demand of portable systems and hybrid electric vehicles, memory protection in complementary metal-oxide-semiconductor (CMOS), logic circuit, videocassette recorders (VCRs), compact disc (CD) players, personal computers (PCs), uninterruptible power supply (UPS) in security alarm systems, remote sensing, smoke detectors, etc. require high power in short-term pulses. Therefore, in the last 20 years, supercapacitors have been required for the development of large and small devices driven by electrical power. In this paper, graphene oxide (GO) was synthesized by improved Hummers method. Two polyaniline (PANI)/graphene oxide nanocomposites electrode materials were prepared from aniline, GO and ammoniumpersulfate (APS) by in situ chemical polymerization with the mass ratios (mGO:mAniline) 10:90 and 30: 70 in ice bath. The crystal structure and the surface topography of all materials were characterized by means of x-ray diffraction (XRD), Fourier transform infrared spectrum (FTIR), Raman spectroscopy and scanning electron microscopy (SEM). The electrochemical properties of the composites were evaluated by cyclic voltammetry (CV), charge-discharge measurements and electrical impedance spectroscopy (EIS), respectively. The results show that the composites have similar and enhanced cyclic voltammetry performance compared with pure PANI based electrode material. The graphene/PANI composite synthesized with the mass ratio (mANI:mGO) 90:10 possessed good capacitive behavior with a specific capacitance as high as 1509.35 F/g at scan rate of 1 mV/s in scanning potential window from -0.8 V to 0.8 V.

An Approach to Solid-State Electrical Double Layer Capacitors Fabricated with Graphene Oxide-Doped, Ionic Liquid-Based Solid Copolymer Electrolytes

PubMed Central

Fattah, N. F. A.; Ng, H. M.; Mahipal, Y. K.; Numan, Arshid; Ramesh, S.; Ramesh, K.

2016-01-01

Solid polymer electrolyte (SPE) composed of semi-crystalline poly (vinylidene fluoride-hexafluoropropylene) [P(VdF-HFP)] copolymer, 1-ethyl-3-methylimidazolium bis (trifluoromethyl sulphonyl) imide [EMI-BTI] and graphene oxide (GO) was prepared and its performance evaluated. The effects of GO nano-filler were investigated in terms of enhancement in ionic conductivity along with the electrochemical properties of its electrical double layer capacitors (EDLC). The GO-doped SPE shows improvement in ionic conductivity compared to the P(VdF-HFP)-[EMI-BTI] SPE system due to the existence of the abundant oxygen-containing functional group in GO that assists in the improvement of the ion mobility in the polymer matrix. The complexation of the materials in the SPE is confirmed in X-ray diffraction (XRD) and thermogravimetric analysis (TGA) studies. The electrochemical performance of EDLC fabricated with GO-doped SPE is examined using cyclic voltammetry and charge–discharge techniques. The maximum specific capacitance obtained is 29.6 F∙g−1, which is observed at a scan rate of 3 mV/s in 6 wt % GO-doped, SPE-based EDLC. It also has excellent cyclic retention as it is able keep the performance of the EDLC at 94% even after 3000 cycles. These results suggest GO doped SPE plays a significant role in energy storage application. PMID:28773573

An Approach to Solid-State Electrical Double Layer Capacitors Fabricated with Graphene Oxide-Doped, Ionic Liquid-Based Solid Copolymer Electrolytes.

PubMed

Fattah, N F A; Ng, H M; Mahipal, Y K; Numan, Arshid; Ramesh, S; Ramesh, K

2016-06-06

Solid polymer electrolyte (SPE) composed of semi-crystalline poly (vinylidene fluoride-hexafluoropropylene) [P(VdF-HFP)] copolymer, 1-ethyl-3-methylimidazolium bis (trifluoromethyl sulphonyl) imide [EMI-BTI] and graphene oxide (GO) was prepared and its performance evaluated. The effects of GO nano-filler were investigated in terms of enhancement in ionic conductivity along with the electrochemical properties of its electrical double layer capacitors (EDLC). The GO-doped SPE shows improvement in ionic conductivity compared to the P(VdF-HFP)-[EMI-BTI] SPE system due to the existence of the abundant oxygen-containing functional group in GO that assists in the improvement of the ion mobility in the polymer matrix. The complexation of the materials in the SPE is confirmed in X-ray diffraction (XRD) and thermogravimetric analysis (TGA) studies. The electrochemical performance of EDLC fabricated with GO-doped SPE is examined using cyclic voltammetry and charge-discharge techniques. The maximum specific capacitance obtained is 29.6 F∙g -1 , which is observed at a scan rate of 3 mV/s in 6 wt % GO-doped, SPE-based EDLC. It also has excellent cyclic retention as it is able keep the performance of the EDLC at 94% even after 3000 cycles. These results suggest GO doped SPE plays a significant role in energy storage application.

Development of a rapid low cost fluorescent biosensor for the detection of food contaminants.

PubMed

McGrath, Terry F; Andersson, Karl; Campbell, Katrina; Fodey, Terry L; Elliott, Christopher T

2013-03-15

A prototype fluorescent based biosensor has been developed for the antibody based detection of food related contaminants. Its performance was characterised and showed a typical antibody binding signal of 200-2000 mV, a short term noise of 9.1 mV, and baseline slope of -0.016 mV/s over 4h. Bulk signal detection repeatability (n=23) and reproducibility (n=3) were less than 2.4%CV. The biosensor detection unit was evaluated using two food related model systems proving its ability to monitor both binding using commercial products and inhibition through the development of an assay. This assay development potential was evaluated by observing the biosensor's performance whilst appraising several labelled antibody and glass slide configurations. The molecular interaction between biotin and an anti-biotin antibody was shown to be inhibited by 41% due to the presence of biotin in a sample. A food toxin (domoic acid) calibration curve was produced, with %CVs ranging from 2.7 to 7.8%, and a midpoint of approximately 17 ng/ml with further optimisation possible. The ultimate aim of this study was to demonstrate the working principles of this innovative biosensor as a potential portable tool with the opportunity of interchangeable assays. The biosensor design is applicable for the requirements of routine food contaminant analysis, with respect to performance, functionality and cost. Copyright © 2012 Elsevier B.V. All rights reserved.

Two-Dimensional Vanadium Carbide (MXene) as Positive Electrode for Sodium-Ion Capacitors.

PubMed

Dall'Agnese, Yohan; Taberna, Pierre-Louis; Gogotsi, Yury; Simon, Patrice

2015-06-18

Ion capacitors store energy through intercalation of cations into an electrode at a faster rate than in batteries and within a larger potential window. These devices reach a higher energy density compared to electrochemical double layer capacitor. Li-ion capacitors are already produced commercially, but the development of Na-ion capacitors is hindered by lack of materials that would allow fast intercalation of Na-ions. Here we investigated the electrochemical behavior of 2D vanadium carbide, V2C, from the MXene family. We investigated the mechanism of Na intercalation by XRD and achieved capacitance of ∼100 F/g at 0.2 mV/s. We assembled a full cell with hard carbon as negative electrode, a known anode material for Na ion batteries, and achieved capacity of 50 mAh/g with a maximum cell voltage of 3.5 V.

Preparation of Shape-Controlled Graphene/Co3O4 Composites for Supercapacitors

NASA Astrophysics Data System (ADS)

Chen, Jun; Chen, Ningna; Feng, Xiaomiao; Hou, Wenhua

2016-09-01

Graphene/Co3O4 nanocomposites with different morphologies were fabricated by hydrothermal method. The morphology of nanocomposites was characterized by scanning electron microscopy. These composites could be used as the electrode materials for supercapacitors. The eletrochemical behavior of the composite was tested by cyclic voltammetry and galvanostatic charge-discharge measurements in 1.0 mol/L KOH solution. The results showed that the graphene/Co3O4 nanopetal composite exhibited excellent electrochemical performance. The specific capacitance value could reach up to 714 F/g at a scan rate of 2 mV/s. Besides, the capacitance of the graphene/Co3O4 nanopetal composite was 841 F/g at a current density of 0.1 A/g. After galvanostatic charge-discharge 1000 laps at the current density of 0.4 A/g, the specific capacitance could keep 96.7% of original capacitive value, demonstrating its good cycling stability.

High performance supercapacitor using porous carbon nanomaterial from corn cob

NASA Astrophysics Data System (ADS)

Sharma, Nallin; Mishra, Neeraj; Sharon, Madhuri; Sharon, Maheshwar

2013-06-01

Carbon synthesized from corn-cob has been used as an electrode in Electrochemical Double Layer Capacitor (EDLC). Dried Corn Cobs, soaked in 1N KOH, 1N HCl or 5% ZnCl2 at 10 0°C for 24 hr, were pyrolyzed in presence of Ar using Co as catalyst at 700-900 °C having dwell time of 60-180 min. The morphology of thus obtained carbon was studied under SEM that showed it to be porous carbon. All the carbon samples synthesized using different parameters were used as electrode for EDLC. Cyclic Voltammetry was used to measure the capacitance. Carbon synthesized from corn cobs pre-treated with 5% ZnCl2 using Co as catalyst pyrolyzed at 700°C for a dwell time of 120 min gave higher Specific capacitance of 270 F/g at scan rate of 5 mV/s. Moreover, this carbon, as observed under SEM, exhibited larger pore size.

Electrochemical capacitance of nanostructured ruthenium-doped tin oxide Sn1- x Ru x O2 by the microemulsion method

NASA Astrophysics Data System (ADS)

Saraswathy, Ramanathan

2017-12-01

Synthesis of nanostructured Ru-doped SnO2 was successfully carried out using the reverse microemulsion method. The phase purity and the crystallite size were analyzed by XRD. The surface morphology and the microstructure of synthesized nanoparticles were analyzed by SEM and TEM. The vibration mode of nanoparticles was investigated using FTIR and Raman studies. The electrochemical behavior of the Ru-doped SnO2 electrode was evaluated in a 0.1 mol/L Na2SO4 solution using cyclic voltammetry. The 5% Ru-doped SnO2 electrode exhibited a high specific capacitance of 535.6 F/g at a scan rate 20 mV/s, possessing good conductivity as well as the electrocycling stability. The Ru-doped SnO2 composite shows excellent electrochemical properties, suggesting that this composite is a promising material for supercapacitors.

Achieving direct electrochemistry of glucose oxidase by one step electrochemical reduction of graphene oxide and its use in glucose sensing.

PubMed

Shamsipur, Mojtaba; Tabrizi, Mahmoud Amouzadeh

2014-12-01

In this paper, the direct electrochemistry of glucose oxidase (GOD) was accomplished at a glassy carbon electrode modified with electrochemically reduced graphene oxide/sodium dodecyl sulfate (GCE/ERGO/SDS). A pair of reversible peaks is exhibited on GCE/ERGO/SDS/GOD by cyclic voltammetry. The peak-to-peak potential separation of immobilized GOD is 28 mV in 0.1 M phosphate buffer solution (pH7.0) with a scan rate of 50 mV/s. The average surface coverage is 2.62×10(-10) mol cm(-2). The resulting biosensor exhibited a good response to glucose with linear range from 1 to 8 mM (R(2)=0.9878), good reproducibility and detection limit of 40.8 μM. The results from the biosensor were similar (±5%) to those obtained from the clinical analyzer. Copyright © 2014 Elsevier B.V. All rights reserved.

Hexagonal VS2 Anchored MWCNTs: First Approach to Design Flexible Solid-State Symmetric Supercapacitor Device.

PubMed

Pandit, Bidhan; Karade, Swapnil S; Sankapal, Babasaheb R

2017-12-27

Transition metal chalcogenides (TMCs) embedded with a carbon network are gaining much attention because of their high power capability, which can be easily integrated to portable electronic devices. Facile chemical route has been explored to synthesize hexagonal structured VS 2 nanoparticles onto multiwalled carbon nanotubes (MWCNTs) matrix. Such surface-modified VS 2 /MWCNTs electrode has boosted the electrochemical performance to reach high capacitance to 830 F/g and excellent stability to 95.9% over 10 000 cycles. Designed flexible solid-state symmetric supercapacitor device (FSSD) with a wide voltage window of 1.6 V exhibited maximum gain in specific capacitance value of 182 F/g at scan rate of 2 mV/s along with specific energy of 42 Wh/kg and a superb stability of 93.2% over 5000 cycles. As a practical approach, FSSD has lightened up "VNIT" panel consisting of 21 red LEDs.

Structure of mono- and bimetallic heterogeneous catalysts based on noble metals obtained by means of fluid technology and metal-vapor synthesis

NASA Astrophysics Data System (ADS)

Said-Galiev, E. E.; Vasil'kov, A. Yu.; Nikolaev, A. Yu.; Lisitsyn, A. I.; Naumkin, A. V.; Volkov, I. O.; Abramchuk, S. S.; Lependina, O. L.; Khokhlov, A. R.; Shtykova, E. V.; Dembo, K. A.; Erkey, C.

2012-10-01

Monometallic nanocomposites are obtained with the use of supercritical carbon dioxide (fluid technique) and metal-vapor synthesis (MVS), while bimetallic nanocomposites of Pt and Au noble metals and γ-Al2O3 oxide matrix are synthesized by a combination of these two methods. The structures, concentrations, and chemical states of metal atoms in composites are studied by means of small-angle X-ray scattering (SAXS), transparent electron microscopy (TEM), X-ray fluorescent analysis (XFA), and X-ray photoelectron spectroscopy (XPS). The neutral state of metal atoms in clusters is shown by XPS and their size distribution is found according to SAXS; as is shown, it is determined by the pore sizes of the oxide matrices and lies in the range of 1 to 50 nm. The obtained composites manifest themselves as effective catalysts in the oxidation of CO to CO2.

VizieR Online Data Catalog: Identifications of Sonneberg variables (Kinnunen+, 1999-2000)

NASA Astrophysics Data System (ADS)

Kinnunen, T.; Skiff, B. A.

2002-09-01

The list below is a continuation of a series providing accurate positions and identifications for variables appearing on the MVS charts (Hoffmeister, 1957, Mitt. Verdander. Sterne, No. 245). The variables here were first described by Hoffmeister (1949, Astron. Abh. Ergaenzungshefte z.d. Astron. Nach., 12, no. 1, A3) in the difficult-to-find ``Ergaenzungshefte'' to the Astronomische Nachrichten, and are the first group from a collection of some 1440 variables from this publication. Details about the identification procedure and table layout are contained in the first report of our series (Kinnunen & Skiff, 2000IBVS.4862....1K). We are grateful to librarians Antoinette Beiser (Lowell) and Brenda Corbin (U. S. Naval Observatory, Washington) for providing a photocopy of the Hoffmeister survey; ``bibliothecaire extraordinaire'' Suzanne Laloe (Obs. Paris-Meudon) advised on how this obscure journal should be cited. (3 data files).

Antibody neutralization of retargeted measles viruses

PubMed Central

Lech, Patrycja J.; Pappoe, Roland; Nakamura, Takafumi; Tobin, Gregory J.; Nara, Peter L.; Russell, Stephen J.

2014-01-01

The measles virus (MV) vaccine lineage is a promising oncolytic but prior exposure to the measles vaccine or wild-type MV strains limits treatment utility due to the presence of anti-measles antibodies. MV entry can be redirected by displaying a polypeptide ligand on the Hemagglutinin (H) C-terminus. We hypothesized that retargeted MV would escape neutralization by monoclonal antibodies (mAbs) recognizing the H receptor-binding surface and be less susceptible to neutralization by human antisera. Using chimeric H proteins, with and without mutations that ablate MV receptor binding, we show that retargeted MVs escape mAbs that target the H receptor-binding surface by virtue of mutations that ablate infection via SLAM and CD46. However, C-terminally displayed domains do not mediate virus entry in the presence of human antibodies that bind to the underlying H domain. In conclusion, utility of retargeted oncolytic measles viruses does not extend to evasion of human serum neutralization. PMID:24725950

Computer vision research with new imaging technology

NASA Astrophysics Data System (ADS)

Hou, Guangqi; Liu, Fei; Sun, Zhenan

2015-12-01

Light field imaging is capable of capturing dense multi-view 2D images in one snapshot, which record both intensity values and directions of rays simultaneously. As an emerging 3D device, the light field camera has been widely used in digital refocusing, depth estimation, stereoscopic display, etc. Traditional multi-view stereo (MVS) methods only perform well on strongly texture surfaces, but the depth map contains numerous holes and large ambiguities on textureless or low-textured regions. In this paper, we exploit the light field imaging technology on 3D face modeling in computer vision. Based on a 3D morphable model, we estimate the pose parameters from facial feature points. Then the depth map is estimated through the epipolar plane images (EPIs) method. At last, the high quality 3D face model is exactly recovered via the fusing strategy. We evaluate the effectiveness and robustness on face images captured by a light field camera with different poses.

Building Facade Modeling Under Line Feature Constraint Based on Close-Range Images

NASA Astrophysics Data System (ADS)

Liang, Y.; Sheng, Y. H.

2018-04-01

To solve existing problems in modeling facade of building merely with point feature based on close-range images , a new method for modeling building facade under line feature constraint is proposed in this paper. Firstly, Camera parameters and sparse spatial point clouds data were restored using the SFM , and 3D dense point clouds were generated with MVS; Secondly, the line features were detected based on the gradient direction , those detected line features were fit considering directions and lengths , then line features were matched under multiple types of constraints and extracted from multi-image sequence. At last, final facade mesh of a building was triangulated with point cloud and line features. The experiment shows that this method can effectively reconstruct the geometric facade of buildings using the advantages of combining point and line features of the close - range image sequence, especially in restoring the contour information of the facade of buildings.

Mycobacterial Cultures Contain Cell Size and Density Specific Sub-populations of Cells with Significant Differential Susceptibility to Antibiotics, Oxidative and Nitrite Stress

PubMed Central

Vijay, Srinivasan; Nair, Rashmi Ravindran; Sharan, Deepti; Jakkala, Kishor; Mukkayyan, Nagaraja; Swaminath, Sharmada; Pradhan, Atul; Joshi, Niranjan V.; Ajitkumar, Parthasarathi

2017-01-01

The present study shows the existence of two specific sub-populations of Mycobacterium smegmatis and Mycobacterium tuberculosis cells differing in size and density, in the mid-log phase (MLP) cultures, with significant differential susceptibility to antibiotic, oxidative, and nitrite stress. One of these sub-populations (~10% of the total population), contained short-sized cells (SCs) generated through highly-deviated asymmetric cell division (ACD) of normal/long-sized mother cells and symmetric cell divisions (SCD) of short-sized mother cells. The other sub-population (~90% of the total population) contained normal/long-sized cells (NCs). The SCs were acid-fast stainable and heat-susceptible, and contained high density of membrane vesicles (MVs, known to be lipid-rich) on their surface, while the NCs possessed negligible density of MVs on the surface, as revealed by scanning and transmission electron microscopy. Percoll density gradient fractionation of MLP cultures showed the SCs-enriched fraction (SCF) at lower density (probably indicating lipid-richness) and the NCs-enriched fraction (NCF) at higher density of percoll fractions. While live cell imaging showed that the SCs and the NCs could grow and divide to form colony on agarose pads, the SCF, and NCF cells could independently regenerate MLP populations in liquid and solid media, indicating their full genomic content and population regeneration potential. CFU based assays showed the SCF cells to be significantly more susceptible than NCF cells to a range of concentrations of rifampicin and isoniazid (antibiotic stress), H2O2 (oxidative stress),and acidified NaNO2 (nitrite stress). Live cell imaging showed significantly higher susceptibility of the SCs of SC-NC sister daughter cell pairs, formed from highly-deviated ACD of normal/long-sized mother cells, to rifampicin and H2O2, as compared to the sister daughter NCs, irrespective of their comparable growth rates. The SC-SC sister daughter cell pairs, formed from the SCDs of short-sized mother cells and having comparable growth rates, always showed comparable stress-susceptibility. These observations and the presence of M. tuberculosis SCs and NCs in pulmonary tuberculosis patients' sputum earlier reported by us imply a physiological role for the SCs and the NCs under the stress conditions. The plausible reasons for the higher stress susceptibility of SCs and lower stress susceptibility of NCs are discussed. PMID:28377757

Effect of Particle Size and Operating Conditions on Pt 3Co PEMFC Cathode Catalyst Durability

DOE PAGES

Gummalla, Mallika; Ball, Sarah; Condit, David; ...

2015-05-29

The initial performance and decay trends of polymer electrolyte membrane fuel cells (PEMFC) cathodes with Pt 3Co catalysts of three mean particle sizes (4.9 nm, 8.1 nm, and 14.8 nm) with identical Pt loadings are compared. Even though the cathode based on 4.9 nm catalyst exhibited the highest initial electrochemical surface area (ECA) and mass activity, the cathode based on 8.1 nm catalyst showed better initial performance at high currents. Owing to the low mass activity of the large particles, the initial performance of the 14.8 nm Pt3Co-based electrode was the lowest. The performance decay rate of the electrodes withmore » the smallest Pt 3Co particle size was the highest and that of the largest Pt 3Co particle size was lowest. Interestingly, with increasing number of decay cycles (0.6 to 1.0 V, 50 mV/s), the relative improvement in performance of the cathode based on 8.1 nm Pt 3Co over the 4.9 nm Pt 3Co increased, owing to better stability of the 8.1 nm catalyst. The electron microprobe analysis (EMPA) of the decayed membrane-electrode assembly (MEA) showed that the amount of Co in the membrane was lower for the larger particles, and the platinum loss into the membrane also decreased with increasing particle size. This suggests that the higher initial performance at high currents with 8.1 nm Pt 3Co could be due to lower contamination of the ionomer in the electrode. Furthermore, lower loss of Co from the catalyst with increased particle size could be one of the factors contributing to the stability of ECA and mass activity of electrodes with larger cathode catalyst particles. To delineate the impact of particle size and alloy effects, these results are compared with prior work from our research group on size effects of pure platinum catalysts. The impact of PEMFC operating conditions, including upper potential, relative humidity, and temperature on the alloy catalyst decay trends, along with the EMPA analysis of the decayed MEAs, are reported.« less

;Green; carbon with hierarchical three dimensional porous structure derived from - Pongamia pinnata seed oil extract cake and NiCo2O4-Ni(OH)2/Multiwall carbon nanotubes nanocomposite as electrode materials for high performance asymmetric supercapacitor

NASA Astrophysics Data System (ADS)

Chaitra, K.; Narendra, Reddy; Venkatesh, Krishna; Nagaraju, N.; Kathyayini, Nagaraju

2017-07-01

Herein, we report for the first time synthesis and electrochemical supercapacitance performance of 3-D hierarchical porous "Green" carbon derived from Pongamia pinnata seed oil extract cake and its activation using different amounts of KOH. Also, nanocomposites of multiwalled carbon nanotubes (MWCNT) with various weight percentages of Ni and Co were prepared by hydrothermal method. Physico-chemical properties of "Green" carbon and nanocomposites were analyzed by Powder X-ray Diffraction, Brunner Emmett Teller surface area, Scanning Electron Microscopy-Elemental Dispersive Spectrum, Transmission Electron Microscopy and Raman techniques. KOH activated carbon was found associated with combination of micropores & mesopores while the nanocomposite with mixture of spinel NiCo2O4 and Ni(OH)2. Porous carbon activated with 2:1::KOH:C (KC2) and the nanocomposite with 1:1 Ni & Co (NC1) exhibited excellent electrochemical performance in three electrode system. Further, fabricated asymmetric supercapacitor (AS) device Ni-Co-MWCNT (NC1)//KC2 exhibited specific capacitance (Cs) of 177 F/g as determined by cyclic voltammetry at 10 mV/s and retained 90% even at 3000th cycle in life cycle test conducted at high current density of 50 A/g. In order to evaluate its practical performance, the AS device was charged to 1.8 V at 5 A/g and used successfully to power a calculator for more than 1 h.

Biomass derived hierarchically porous and heteroatom-doped carbons for supercapacitors.

PubMed

Kang, Xiaonan; Zhu, Hui; Wang, Chuanyi; Sun, Kang; Yin, Jiao

2018-01-01

In this research, Rapeseed dregs (RDs), as a byproduct of agriculture (derived from processing of rapeseed for oil production), were originally employed asa new carbonaceous precursor to synthesize hierarchically porous and heteroatom-doped activated carbons (ACs) with the activation of ZnCl 2 at various high temperatures. A variety of measurements have been adopted to systemically characterize the RD-derived ACs. The micro-morphology, pore structures and surface chemistry property were fully investigated by SEM, TEM, XRD, Raman, N 2 adsorption-desorption analysis, XPS and IR, respectively. The RD-derived ACs possess as large specific surface area as up to 1416.966m 2 g -1 and the pore size distribution concentrates on 1-2, 2-5, 5-15 and 25-35nm, indicating their hierarchically porous structures. Furthermore, electrochemical measurements including electrochemical impedance spectroscopy (EIS), galvanostatic charge/discharge (GCD) and cyclic voltammetry (CV) were conducted to estimate RDAC's supercapacitive performance and rate capability. The investigations illustrated that RD derived ACs reached as high specific capacitance as 170.5 and 153.2Fg -1 at a scan rate of 5mVs -1 in 1M H 2 SO 4 and 1M Et 4 NBF 4 /AN, respectively. In addition, the RD-derived ACs demonstrated good long-term cycling stability and more than 90% initial capacity have been retained after 6400 cycles at a large current density of 1Ag -1 . Copyright © 2017 Elsevier Inc. All rights reserved.

Structural Analysis of the Pärvie Fault in Northern Scandinavia

NASA Astrophysics Data System (ADS)

Baeckstroem, A.; Rantakokko, N.; Ask, M. V.

2011-12-01

The Pärvie fault is the largest known postglacial fault in the world with a length of about 160 km. The structure has a dominating fault scarp as its western perimeter but in several locations it is rather a system of several faults. The current fault scarps, mainly caused by reverse faulting, are on average, 10-15 m in height and are thought to have been formed during one momentous event near the end of the latest glaciation (the Weichselian, 9,500-115,000 BP ) (Lagerbäck & Sundh, 2008). This information has been learnt from studying deformation features in sediments from the latest glaciation. However, the fault is believed to have been formed as early as the Precambrian, and it has been reactivated repeatedly throughout its history. The earlier history of this fault zone is still largely unknown. Here we present a pre-study to the scientific drilling project "Drilling Active Faults in Northern Europe", that was submitted to the International Continental Scientific Drilling Program (ICDP) in 2009 (Kukkonen et al. 2010) with an ICDP-sponsored workshop in 2010 (Kukkonen et al. 2011). During this workshop a major issue to be addressed before the start of drilling was to reveal whether the fault scarps were formed by one big earthquake or by several small ones (Kukkonen et al. 2011). Initial results from a structural analysis by Riad (1990) have produced information of the latest kinematic event where it is suggested that the latest event coincides with the recent stress field, causing a transpressional effect. The geometrical model suggested for an extensive area of several fault scarps along the structure is the compressive tulip structure. In the southern part, where the fault dips steeply E, the structure is parallel to the foliation of the country rock and earlier breccias, thus indicating a dependence of earlier structures. Modelling of the stress field during the latest glaciation show that a reverse background stress field together with excess pore pressure governs the destabilization of a structure, such as the Pärvie fault, rather than the induced stresses from the weight of ice-sheet (Lund, 2005). This is a presentation of the first part of the structural analysis of the brittle structures around the Pärvie fault in order to evaluate its brittle deformation history and to attempt to constrain the paleostress fields causing these deformations. References Kukkonen, I.T., Olesen, O., Ask, M.V.S., and the PFDP Working Group, 2010. Postglacial faults in Fennoscandia: targets for scientific drilling. GFF, 132:71-81. Kukkonen, I.T., Ask, M.V.S., Olesen, O., 2011. Postglacial Fault Drilling in Northern Europe: Workshop in Skokloster, Sweden. Scientific Drilling, 11, doi:10.2204/iodp.sd.11.08.2011. Lagerbäck, R. & Sundh, M., 2008. Early Holocene faulting and paleoseismicity in northern Sweden. Geological survey of Sweden. Research paper, C 836. 80 p. Lund, B., Schmidt, P., Hieronymus, C., 2009. Stress evolution and fault stability during the Weichselian glacial cycle. Swedish Nuclear Fuel and Waste Management Co., Stockholm. TR-09-15. 106 p. Riad, L., 1990. The Pärvie fault, Northern Sweden, Uppsala University. Research report 63. 48 p

Fabrication of free-standing hierarchical carbon nanofiber/graphene oxide/polyaniline films for supercapacitors.

PubMed

Xu, Dongdong; Xu, Qun; Wang, Kaixi; Chen, Jun; Chen, Zhimin

2014-01-08

A hierarchical high-performance electrode with nanoacanthine-style polyaniline (PANI) deposited onto a carbon nanofiber/graphene oxide (CNF/GO) template was successfully prepared via an in situ polymerization process. The morphology analysis shows that introducing one-dimensional (1D) CNF could significantly decrease/inhibit the staking of laminated GO to form an open-porous CNF/GO architecture. Followed with in situ facial deposition of PANI, the as-synthesized PANI modified CNF/GO exhibits three-dimensional (3D) hierarchical layered nanoarchitecture, which favors the diffusion of the electrolyte ions into the inner region of active materials. The hierarchical free-standing electrodes were directly fabricated into sandwich structured supercapacitors using 1 M H2SO4 as the electrolyte showing a significant specific capacitance of 450.2 F/g at the voltage scan rate of 10 mV/s. The electrochemical properties of the hierarchical structure can be further improved by a reduction procedure of GO before the deposition of PANI.

Well-defined flake-like polypyrrole grafted graphene nanosheets composites as electrode materials for supercapacitors with enhanced cycling stability

NASA Astrophysics Data System (ADS)

Wang, Xue; Wang, Tingmei; Yang, Chao; Li, Haidong; Liu, Peng

2013-12-01

Well-defined flake-like polypyrrole grafted graphene nanosheets composites (PPy-g-GNS) were fabricated by the in-situ chemical oxidative grafting polymerization of pyrrole in the presence of the 4-aminophenyl modified graphene nanosheets (AP-GNS), which were prepared via the coupling reaction of the graphene nanosheets (GNS) with diazonium salt. The flake-like PPy-g-GNS composite showed the high conductivity at room temperature. A maximum discharge capacitance of 191.2 F/g at the scan rate of 10 mV/s could be achieved in the three-electrode cell electrochemical testing in 1.0 mol/L NaNO3 electrolyte solution. It is higher than those of the AP-GNS, pure PPy, and the GNS/PPy composite prepared with the unmodified graphene nanosheets (GNS). The flake-like PPy-g-GNS composites also exhibited the excellent electrochemical stability even after 1000 cycles. It revealed the synergistic effect between the conducting polymer and the carbon-based support.

MnO2 nanotubes assembled on conductive graphene/polyester composite fabric as a three-dimensional porous textile electrode for flexible electrochemical capacitors.

PubMed

Jin, Chun; Jin, Li-Na; Guo, Mei-Xia; Liu, Ping; Zhang, Jia-Nan; Bian, Shao-Wei

2017-12-15

A three-dimensional (3D) electrode material was successfully synthesized through a facile ZnO-assisted hydrothermal process in which vertical MnO 2 nanotube arrays were in situ grown on the conductive graphene/polyester composite fabric. The morphology and structure of MnO 2 nanotubes/graphene/polyester textile electrode were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The 3D electrode structure facilitates to achieve the maximum number of active sites for the pesudocapacitance redox reaction, fast electrolyte ion transportation and short ion diffusion path. The electrochemical measurements showed that the electrode possesses good capacitance capacity which reached 498F/g at a scan rate of 2mV/s in Na 2 SO 4 electrolyte solution. The electrode also showed stable electrochemical performances under the conditions of long-term cycling, and mechanical bending and twisting. Copyright © 2017 Elsevier Inc. All rights reserved.

Few layered MoO3 nano sheets-SWCNT composite thin film as supercapacitor electrode

NASA Astrophysics Data System (ADS)

Dutta, Shibsankar; Akther, Jasim; De, Sukanta

2017-05-01

The increasing demands for clean and renewable energy, the advantages of high power density, long lasting and high efficiency have made Supercapacitor as one of the major emerging energy storage device.The 2D layered metal oxide nanocomposite with SWCNT is the promising candidate for energy storage and conversion. In this work we exfoliate the crystalline bulk MoO3 by simple liquid phase exfoliation to give multi-layer MoO3 dispersed in a suitable solvent. As the electrical conductivity of MoO3 is very low so, the dispersion was used to make hybrid material with SWCNT dispersion by vacuum filtration. The SWCNT-MoO3 composite showed an areal capacitance value of 1290 µF/cm2 at 10 mV/s in PVA-H2 SO4 solid gel electrolyte. This composite based electrode provides an energy density of 0.092 µWh/cm2 and a power density of 9.54 µW/cm2 at 0.01 mA/cm2

Preparation of Titanium nitride nanomaterials for electrode and application in energy storage

NASA Astrophysics Data System (ADS)

Tang, Shun; Cheng, Qi; Zhao, Jinxing; Liang, Jiyuan; Liu, Chang; Lan, Qian; Cao, Yuan-Cheng; Liu, Jiyan

The Titanium nitride was made by the carbamide and titanic chloride precursors. XRD results indicate that the precursor ratio N:Ti 3:1 leads to higher crystallinity. SEM and EDX demonstrated that Ti and N elements were distributed uniformly with the ratio of 1:1. The TiN used as the electrode material for supercapacitor was also studied. The specific capacities were changed from 407 F.g-1 to 385 F.g-1, 364 F.g-1 and 312 F.g-1, when the current densities were changed from 1 A.g-1 to 2 A.g-1, 5 A.g-1 and 10 A.g-1, respectively. Chronopotentiometry tests showed high coulombic efficiency. Cycling performance of the TiN electrode was evaluated by CV at a scanning rate of 50 mV.s-1 for 20,000 cycles and there was about 9.8% loss. These results indicate that TiN is a promising electrode material for the supercapacitors.

Detection of vitamin b1 (thiamine) using modified carbon paste electrodes with polypyrrole

NASA Astrophysics Data System (ADS)

Muppariqoh, N. M.; Wahyuni, W. T.; Putra, B. R.

2017-03-01

Vitamin B1 (thiamine) is oxidized in alkaline medium and can be detected by cyclic voltammetry technique using carbon paste electrode (CPE) as a working electrode. polypyrrole-modified CPE were used in this study to increase sensitivity and selectivity measurement of thiamine. Molecularly imprinted polymers (MIP) of the modified CPE was prepared through electrodeposition of pyrrole. Measurement of thiamine performed in KCl 0.05 M (pH 10, tris buffer) using CPE and the modified CPE gave an optimum condition anodic current of thiamine at 0.3 V, potential range (-1.6_1 V), and scan rate of 100 mV/s. Measurement of thiamine using polypyrrole modified CPE (CPE-MIPpy) showed better result than CPE itself with detection limit of 6.9×10-5 M and quantitation limit 2.1×10-4 M. CPE-MIPpy is selective to vita min B1. In conclusion, CPE-MIPpy as a working electrode showed better performance of thiamine measurement than that of CPE.

Copper oxide nanowires as better performance electrode material for supercapacitor application

NASA Astrophysics Data System (ADS)

Yar, A.; Dennis, J. O.; Mohamed, N. M.; Mian, M. U.; Irshad, M. I.; Mumtaz, A.

2016-11-01

Supercapacitors are highly attractive energy storage devices which are capable of delivering high power, with fast charging and long cycle life. Carbon based material rely on physical charging with less capacitance while metal oxide store charge by fast redox reaction with increased capacitance. Among metal oxide, copper oxide compounds are widely use in the form of nano and micro structures with no definite control over structure. In this work we utilized the well-controlled structure copper wires, originated from AAO template. Such well controlled structure offer better capacitance values due to easily excess of ions to the surface of wires. Performance of material was check in 3 M of potassium hydroxide (KOH). Specific capacitance (Cs) was calculated by using cyclic voltammetry (CV) and Charge discharge (CDC) test. The capacitance calculate on base on CV at 25 mV/s was 101.37 F/g while CDC showed the capacitance of 90 F/g at 2 A/g.

Nanostructured Electrode Materials Derived from Metal-Organic Framework Xerogels for High-Energy-Density Asymmetric Supercapacitor.

PubMed

Mahmood, Asif; Zou, Ruqiang; Wang, Qingfei; Xia, Wei; Tabassum, Hassina; Qiu, Bin; Zhao, Ruo

2016-01-27

This work successfully demonstrates metal-organic framework (MOF) derived strategy to prepare nanoporous carbon (NPC) with or without Fe3O4/Fe nanoparticles by the optimization of calcination temperature as highly active electrode materials for asymmetric supercapacitors (ASC). The nanostructured Fe3O4/Fe/C hybrid shows high specific capacitance of 600 F/g at a current density of 1 A/g and excellent capacitance retention up to 500 F/g at 8 A/g. Furthermore, hierarchically NPC with high surface area also obtained from MOF gels displays excellent electrochemical performance of 272 F/g at 2 mV/s. Considering practical applications, aqueous ASC (aASC) was also assembled, which shows high energy density of 17.496 Wh/kg at the power density of 388.8 W/kg. The high energy density and excellent capacity retention of the developed materials show great promise for the practical utilization of these energy storage devices.

User's guide: Programs for processing altimeter data over inland seas

NASA Technical Reports Server (NTRS)

Au, A. Y.; Brown, R. D.; Welker, J. E.

1989-01-01

The programs described were developed to process GEODYN-formatted satellite altimeter data, and to apply the processed results to predict geoid undulations and gravity anomalies of inland sea areas. These programs are written in standard FORTRAN 77 and are designed to run on the NSESCC IBM 3081(MVS) computer. Because of the experimental nature of these programs they are tailored to the geographical area analyzed. The attached program listings are customized for processing the altimeter data over the Black Sea. Users interested in the Caspian Sea data are expected to modify each program, although the required modifications are generally minor. Program control parameters are defined in the programs via PARAMETER statements and/or DATA statements. Other auxiliary parameters, such as labels, are hard-wired into the programs. Large data files are read in or written out through different input or output units. The program listings of these programs are accompanied by sample IBM job control language (JCL) images. Familiarity with IBM JCL and the TEMPLATE graphic package is assumed.

The Investigation of Electrochemistry Behaviors of Tyrosinase Based on Directly-Electrodeposited Grapheneon Choline-Gold Nanoparticles.

PubMed

He, Yaping; Yang, Xiaohui; Han, Quan; Zheng, Jianbin

2017-06-23

A novel catechol (CA) biosensor was developed by embedding tyrosinase (Tyr) onto in situ electrochemical reduction graphene (EGR) on choline-functionalized gold nanoparticle (AuNPs-Ch) film. The results of UV-Vis spectra indicated that Tyr retained its original structure in the film, and an electrochemical investigation of the biosensor showed a pair of well-defined, quasi-reversible redox peaks with E pa = -0.0744 V and E pc = -0.114 V (vs. SCE) in 0.1 M, pH 7.0 sodium phosphate-buffered saline at a scan rate of 100 mV/s. The transfer rate constant k s is 0.66 s -1 . The Tyr-EGR/AuNPs-Ch showed a good electrochemical catalytic response for the reduction of CA, with the linear range from 0.2 to 270 μM and a detection limit of 0.1 μM (S/N = 3). The apparent Michaelis-Menten constant was estimated to be 109 μM.

Effect of Fe doping on the electrochemical capacitor behavior of MnO2 nanocrystals

NASA Astrophysics Data System (ADS)

Poonguzhali, R.; Shanmugam, N.; Gobi, R.; Senthilkumar, A.; Viruthagiri, G.; Kannadasan, N.

2015-10-01

In this work, the influence of Fe doping on the capacitance behavior of MnO2 nanoparticles synthesized by chemical precipitation was investigated. During the doping process the concentration of Fe was increased from 0.025 M to 0.125 M in steps of 0.025 M. The products obtained were characterized by X-ray diffraction, Fourier infrared spectroscopy, scanning electron microscopy and N2 adsorption-desorption isotherms. To demonstrate the suitability of Fe-doped MnO2 for capacitor applications, cyclic voltammetry, galvanostatic charge-discharge and electrochemical impedance were recorded. Among the different levels of doping, the specific capacitance of 912 F/g was delivered by 0.075 M of Fe-doped MnO2 at a scan rate of 10 mV/s, which is almost more than fourfold that of the bare MnO2 electrode (210 F/g). Moreover, for the same concentration the charge, discharge studies revealed the highest specific capacitance of 1084 F/g at a current density of 10 A/g.

Antibody neutralization of retargeted measles viruses.

PubMed

Lech, Patrycja J; Pappoe, Roland; Nakamura, Takafumi; Tobin, Gregory J; Nara, Peter L; Russell, Stephen J

2014-04-01

The measles virus (MV) vaccine lineage is a promising oncolytic but prior exposure to the measles vaccine or wild-type MV strains limits treatment utility due to the presence of anti-measles antibodies. MV entry can be redirected by displaying a polypeptide ligand on the Hemagglutinin (H) C-terminus. We hypothesized that retargeted MV would escape neutralization by monoclonal antibodies (mAbs) recognizing the H receptor-binding surface and be less susceptible to neutralization by human antisera. Using chimeric H proteins, with and without mutations that ablate MV receptor binding, we show that retargeted MVs escape mAbs that target the H receptor-binding surface by virtue of mutations that ablate infection via SLAM and CD46. However, C-terminally displayed domains do not mediate virus entry in the presence of human antibodies that bind to the underlying H domain. In conclusion, utility of retargeted oncolytic measles viruses does not extend to evasion of human serum neutralization. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

A field evaluation of real-life motor vehicle accidents: presence of unrestrained objects and their association with distribution and severity of patient injuries.

PubMed

Staff, Trine; Eken, Torsten; Hansen, Trond Boye; Steen, Petter Andreas; Søvik, Signe

2012-03-01

Moving objects may pose an added threat to car occupants in motor vehicle accidents (MVAs). However, to our knowledge, there have only been two case studies published on the subject. For the present study, accident reports and photo documentation from MVAs were collected on-scene by dedicated paramedics. Emergency medical service personnel on-scene were interviewed as necessary. Potentially harmful unrestrained objects in the involved motor vehicles (MVs) were identified and categorised by type, weight and hardness. Seatback offset by unrestrained objects was noted. The patient injury distribution (Abbreviated Injury Scale (AIS) body regions) and severity (AIS severity scores and New Injury Severity Score (NISS) scores) were retrospectively determined from hospital and autopsy records, and their potential relationship to unrestrained objects was explored. A total of 190 accidents involving 338 MVs and 618 individuals were included. In total, 327 individuals (53%) were injured, and 61 (10%) died. 37 of 61 were not autopsied. The mean NISS was 17 (median 8, interquartile range (IQR) 1-27). Unrestrained objects were reported for 133 motor vehicles (39%) involving 293 individuals. 35% of the unrestrained objects found in the passenger compartment weighed >2 kg. In the boot, 32% of objects weighed >20 kg. Seatback offset associated with unrestrained objects was found for 45 individuals (15%). Unrestrained objects originally located in the boot (heavy luggage, groceries and tyres were the most frequently reported) had moved into the passenger compartment on impact in 27 cases, 24 of which were associated with seatback offset. An in-depth analysis was performed on 24 patients whose injuries were highly likely to be associated with unrestrained objects, as indicated by accident reports and medical documentation. Nineteen (79%) were involved in frontal collisions, and 12 (50%) died on-scene. The mean NISS was 51.7 (median 51, IQR 27-75) in the 17 (71%) patients with seatback offset and 37.2 (median 41, IQR 22.5-50) in the 7 (29%) without seatback offset. Seatback offset was associated with more severe head and thoracic injuries and an increased incidence of abdominal and pelvic injuries. Patients injured by unrestrained objects while sitting in unharmed car seats predominantly suffered head, cervical spine and thoracic injuries. Our results indicate a need for public information campaigns. The development of car backseats that can better sustain hits from heavy objects in the cargo boot is an important area for the motor vehicle production industry to explore. Copyright © 2011 Elsevier Ltd. All rights reserved.

Potentiodynamic polarization study of the in vitro corrosion behavior of 3 high-palladium alloys and a gold-palladium alloy in 5 media.

PubMed

Sun, Desheng; Monaghan, Peter; Brantley, William A; Johnston, William M

2002-01-01

Corrosion of cast alloy restorations may lead to their failure or adversely affect their biocompatibility. Although some documentation of the corrosion behavior of the high-palladium dental alloys exists, questions remain about their corrosion resistance and mechanisms. This study compared the in vitro corrosion characteristics of 3 high-palladium alloys and 1 gold-palladium alloy in simulated body fluid and oral environments. Two Pd-Cu-Ga alloys and 1 Pd-Ga alloy were selected; an Au-Pd alloy served as the control. The corrosion behavior for the as-cast and simulated porcelain-firing (heat-treated) conditions of each alloy (N = 5) was evaluated in 0.9% NaCl, 0.09% NaCl, and Fusayama solutions. Heat-treated specimens of each alloy (N = 5) were also tested in N(2)-deaerated 0.09% NaCl and Fusayama solutions (pH 4). After immersion in the electrolyte for 24 hours, the open-circuit potential (OCP) was measured, and linear polarization was performed from -20 mV to +20 mV (vs. OCP) at a scanning rate of 0.125 mV/s. Cyclic polarization was performed from -300 mV to +1000 mV and back to -300 mV (vs. OCP) at a scanning rate of 1 mV/s. Data were evaluated with analysis of variance and the Ryan-Einot-Gabriel-Welsch multiple-range test (alpha=.05). The OCP of each alloy varied with the condition (as-cast or heat-treated) and electrolyte used. Corrosion resistance was similar for the 4 alloys tested. For cyclic polarization, all alloys showed active-passive or spontaneous passive behavior in nearly all electrolytes. During some reverse scans, the 3 high-palladium alloys displayed 3 or 5 anodic peaks. No positive hysteresis was observed for any of the alloy/electrolyte combinations evaluated. The corrosion resistances of the 3 high-palladium alloys in simulated body fluid and oral environments were comparable to that of the gold-palladium alloy. The similar corrosion resistance for the 3 high-palladium alloys was attributed to their high noble metal content and theorized stable structure at the submicron level. Selective corrosion of different phases and elements, surface enrichment of palladium, and adsorption of species are possible corrosion mechanisms. The cyclic polarization results suggest that none of the 4 alloys would be prone to pitting or crevice corrosion under in vivo conditions, but crevice conditions should nonetheless be avoided for these alloys in the oral environment.

Mapping snow depth in complex alpine terrain with close range aerial imagery - estimating the spatial uncertainties of repeat autonomous aerial surveys over an active rock glacier

NASA Astrophysics Data System (ADS)

Goetz, Jason; Marcer, Marco; Bodin, Xavier; Brenning, Alexander

2017-04-01

Snow depth mapping in open areas using close range aerial imagery is just one of the many cases where developments in structure-from-motion and multi-view-stereo (SfM-MVS) 3D reconstruction techniques have been applied for geosciences - and with good reason. Our ability to increase the spatial resolution and frequency of observations may allow us to improve our understanding of how snow depth distribution varies through space and time. However, to ensure accurate snow depth observations from close range sensing we must adequately characterize the uncertainty related to our measurement techniques. In this study, we explore the spatial uncertainties of snow elevation models for estimation of snow depth in a complex alpine terrain from close range aerial imagery. We accomplish this by conducting repeat autonomous aerial surveys over a snow-covered active-rock glacier located in the French Alps. The imagery obtained from each flight of an unmanned aerial vehicle (UAV) is used to create an individual digital elevation model (DEM) of the snow surface. As result, we obtain multiple DEMs of the snow surface for the same site. These DEMs are obtained from processing the imagery with the photogrammetry software Agisoft Photoscan. The elevation models are also georeferenced within Photoscan using the geotagged imagery from an onboard GNSS in combination with ground targets placed around the rock glacier, which have been surveyed with highly accurate RTK-GNSS equipment. The random error associated with multi-temporal DEMs of the snow surface is estimated from the repeat aerial survey data. The multiple flights are designed to follow the same flight path and altitude above the ground to simulate the optimal conditions of repeat survey of the site, and thus try to estimate the maximum precision associated with our snow-elevation measurement technique. The bias of the DEMs is assessed with RTK-GNSS survey observations of the snow surface elevation of the area on and surrounding the rock glacier. Additionally, one of the challenges with processing snow cover imagery with SfM-MVS is dealing with the general homogeneity of the surface, which makes is difficult for automated-feature detection algorithms to identify key features for point matching. This challenge depends on the snow cover surface conditions, such as scale, lighting conditions (high vs. low contrast), and availability of snow-free features within a scene, among others. We attempt to explore this aspect by spatial modelling the factors influencing the precision and bias of the DEMs from image, flight, and terrain attributes.

Proteoliposomes harboring alkaline phosphatase and nucleotide pyrophosphatase as matrix vesicle biomimetics.

PubMed

Simão, Ana Maria S; Yadav, Manisha C; Narisawa, Sonoko; Bolean, Mayte; Pizauro, Joao Martins; Hoylaerts, Marc F; Ciancaglini, Pietro; Millán, José Luis

2010-03-05

We have established a proteoliposome system as an osteoblast-derived matrix vesicle (MV) biomimetic to facilitate the study of the interplay of tissue-nonspecific alkaline phosphatase (TNAP) and NPP1 (nucleotide pyrophosphatase/phosphodiesterase-1) during catalysis of biomineralization substrates. First, we studied the incorporation of TNAP into liposomes of various lipid compositions (i.e. in pure dipalmitoyl phosphatidylcholine (DPPC), DPPC/dipalmitoyl phosphatidylserine (9:1 and 8:2), and DPPC/dioctadecyl-dimethylammonium bromide (9:1 and 8:2) mixtures. TNAP reconstitution proved virtually complete in DPPC liposomes. Next, proteoliposomes containing either recombinant TNAP, recombinant NPP1, or both together were reconstituted in DPPC, and the hydrolysis of ATP, ADP, AMP, pyridoxal-5'-phosphate (PLP), p-nitrophenyl phosphate, p-nitrophenylthymidine 5'-monophosphate, and PP(i) by these proteoliposomes was studied at physiological pH. p-Nitrophenylthymidine 5'-monophosphate and PLP were exclusively hydrolyzed by NPP1-containing and TNAP-containing proteoliposomes, respectively. In contrast, ATP, ADP, AMP, PLP, p-nitrophenyl phosphate, and PP(i) were hydrolyzed by TNAP-, NPP1-, and TNAP plus NPP1-containing proteoliposomes. NPP1 plus TNAP additively hydrolyzed ATP, but TNAP appeared more active in AMP formation than NPP1. Hydrolysis of PP(i) by TNAP-, and TNAP plus NPP1-containing proteoliposomes occurred with catalytic efficiencies and mild cooperativity, effects comparable with those manifested by murine osteoblast-derived MVs. The reconstitution of TNAP and NPP1 into proteoliposome membranes generates a phospholipid microenvironment that allows the kinetic study of phosphosubstrate catabolism in a manner that recapitulates the native MV microenvironment.

Proteoliposomes Harboring Alkaline Phosphatase and Nucleotide Pyrophosphatase as Matrix Vesicle Biomimetics*

PubMed Central

Simão, Ana Maria S.; Yadav, Manisha C.; Narisawa, Sonoko; Bolean, Mayte; Pizauro, Joao Martins; Hoylaerts, Marc F.; Ciancaglini, Pietro; Millán, José Luis

2010-01-01

We have established a proteoliposome system as an osteoblast-derived matrix vesicle (MV) biomimetic to facilitate the study of the interplay of tissue-nonspecific alkaline phosphatase (TNAP) and NPP1 (nucleotide pyrophosphatase/phosphodiesterase-1) during catalysis of biomineralization substrates. First, we studied the incorporation of TNAP into liposomes of various lipid compositions (i.e. in pure dipalmitoyl phosphatidylcholine (DPPC), DPPC/dipalmitoyl phosphatidylserine (9:1 and 8:2), and DPPC/dioctadecyl-dimethylammonium bromide (9:1 and 8:2) mixtures. TNAP reconstitution proved virtually complete in DPPC liposomes. Next, proteoliposomes containing either recombinant TNAP, recombinant NPP1, or both together were reconstituted in DPPC, and the hydrolysis of ATP, ADP, AMP, pyridoxal-5′-phosphate (PLP), p-nitrophenyl phosphate, p-nitrophenylthymidine 5′-monophosphate, and PPi by these proteoliposomes was studied at physiological pH. p-Nitrophenylthymidine 5′-monophosphate and PLP were exclusively hydrolyzed by NPP1-containing and TNAP-containing proteoliposomes, respectively. In contrast, ATP, ADP, AMP, PLP, p-nitrophenyl phosphate, and PPi were hydrolyzed by TNAP-, NPP1-, and TNAP plus NPP1-containing proteoliposomes. NPP1 plus TNAP additively hydrolyzed ATP, but TNAP appeared more active in AMP formation than NPP1. Hydrolysis of PPi by TNAP-, and TNAP plus NPP1-containing proteoliposomes occurred with catalytic efficiencies and mild cooperativity, effects comparable with those manifested by murine osteoblast-derived MVs. The reconstitution of TNAP and NPP1 into proteoliposome membranes generates a phospholipid microenvironment that allows the kinetic study of phosphosubstrate catabolism in a manner that recapitulates the native MV microenvironment. PMID:20048161

Freestanding three-dimensional graphene/MnO2 composite networks as ultralight and flexible supercapacitor electrodes.

PubMed

He, Yongmin; Chen, Wanjun; Li, Xiaodong; Zhang, Zhenxing; Fu, Jiecai; Zhao, Changhui; Xie, Erqing

2013-01-22

A lightweight, flexible, and highly efficient energy management strategy is needed for flexible energy-storage devices to meet a rapidly growing demand. Graphene-based flexible supercapacitors are one of the most promising candidates because of their intriguing features. In this report, we describe the use of freestanding, lightweight (0.75 mg/cm(2)), ultrathin (<200 μm), highly conductive (55 S/cm), and flexible three-dimensional (3D) graphene networks, loaded with MnO(2) by electrodeposition, as the electrodes of a flexible supercapacitor. It was found that the 3D graphene networks showed an ideal supporter for active materials and permitted a large MnO(2) mass loading of 9.8 mg/cm(2) (~92.9% of the mass of the entire electrode), leading to a high area capacitance of 1.42 F/cm(2) at a scan rate of 2 mV/s. With a view to practical applications, we have further optimized the MnO(2) content with respect to the entire electrode and achieved a maximum specific capacitance of 130 F/g. In addition, we have also explored the excellent electrochemical performance of a symmetrical supercapacitor (of weight less than 10 mg and thickness ~0.8 mm) consisting of a sandwich structure of two pieces of 3D graphene/MnO(2) composite network separated by a membrane and encapsulated in polyethylene terephthalate (PET) membranes. This research might provide a method for flexible, lightweight, high-performance, low-cost, and environmentally friendly materials used in energy conversion and storage systems for the effective use of renewable energy.

Erosion rates of a small coastal island revealed by repeated measurements using TLS and UAS-SfM photogrammetry

NASA Astrophysics Data System (ADS)

Hayakawa, Y. S.; Obanawa, H.

2016-12-01

Due to the weak bedrock and constant wave erosion, sea cliffs along the outer Boso Peninsula, central Japan, have been eroded at ca. 1 m per year for centuries. Modern coastal protection work had significantly reduced the erosion rate, while this became a cause of limited supply of sands along beaches in this area. Among the almost complete protection, a small coastal island, so-called Suzume-Jima Island (70 km southeast of Tokyo), has not been protected, in which we can still observe processes of coastal cliff erosion at the original rate. We have performed multi-temporal (3 times a year), high-resolution (centimeters) topographic measurements of the small island for 3 years, using terrestrial laser scanning (TLS) and structure-from-motion multi-view stereo (SfM-MVS) photogrammetry with an unmanned aerial system (UAS). Landside of the island can be measured by both TLS and UAS, but the seaside could only be captured by UAS, therefore these data are combined to analyze the entire island morphology with a reasonable accuracy. Frequent, spatially variable wave erosion and rockfalls were observed during the measurement period. The dominant wave direction and geologic structure (joint location and orientation) may account for these differences. A severe notch development in the cliff suggests a possible formation of a sea cave through the island in the near future. The measured, short-term results were also compared with the longer-term development of the island shape, obtained by historical aerial photographs for 50 years.

Electrochemical sensor for catechol and dopamine based on a catalytic molecularly imprinted polymer-conducting polymer hybrid recognition element.

PubMed

Lakshmi, Dhana; Bossi, Alessandra; Whitcombe, Michael J; Chianella, Iva; Fowler, Steven A; Subrahmanyam, Sreenath; Piletska, Elena V; Piletsky, Sergey A

2009-05-01

One of the difficulties with using molecularly imprinted polymers (MIPs) and other electrically insulating materials as the recognition element in electrochemical sensors is the lack of a direct path for the conduction of electrons from the active sites to the electrode. We have sought to address this problem through the preparation and characterization of novel hybrid materials combining a catalytic MIP, capable of oxidizing the template, catechol, with an electrically conducting polymer. In this way a network of "molecular wires" assists in the conduction of electrons from the active sites within the MIP to the electrode surface. This was made possible by the design of a new monomer that combines orthogonal polymerizable functionality; comprising an aniline group and a methacrylamide. Conducting films were prepared on the surface of electrodes (Au on glass) by electropolymerization of the aniline moiety. A layer of MIP was photochemically grafted over the polyaniline, via N,N'-diethyldithiocarbamic acid benzyl ester (iniferter) activation of the methacrylamide groups. Detection of catechol by the hybrid-MIP sensor was found to be specific, and catechol oxidation was detected by cyclic voltammetry at the optimized operating conditions: potential range -0.6 V to +0.8 V (vs Ag/AgCl), scan rate 50 mV/s, PBS pH 7.4. The calibration curve for catechol was found to be linear to 144 microM, with a limit of detection of 228 nM. Catechol and dopamine were detected by the sensor, whereas analogues and potentially interfering compounds, including phenol, resorcinol, hydroquinone, serotonin, and ascorbic acid, had minimal effect (< or = 3%) on the detection of either analyte. Non-imprinted hybrid electrodes and bare gold electrodes failed to give any response to catechol at concentrations below 0.5 mM. Finally, the catalytic properties of the sensor were characterized by chronoamperometry and were found to be consistent with Michaelis-Menten kinetics.

Anodic Stripping Voltammetry with Pencil Graphite Electrode for Determination of Chromium (III)

NASA Astrophysics Data System (ADS)

Wyantuti, S.; Hafidza, R. A.; Ishmayana, S.; Hartati, Y. W.

2017-02-01

Chromium is required as micronutrient that has roles in insulin metabolism and blood glucose level regulation. Chromium (III) deficiency can cause hyperglycemia and glycosuria. However, a high amount of chromium in body can cause allergic reaction, organ damage, and even death because of its toxicity. Chromium is commonly used in steel industries. Simultaneously with the development of industry, the waste disposal that can endanger environment also increased. Therefore, a sensitive and specific analysis method for chromium detection is required. Stripping voltammetry is one of the voltammetric methods that is commonly used for heavy metal analysis due to the very low limit of detection (sub ppb). The present study was conducted to develop an analysis method for chromium (III) determination using pencil graphite electrode. Quantitative determination was performed for chromium (III) which measured at -0.8 to +1.0 V with deposition time for 60 s and 50 mV/s scan rate. Stripping voltammetric analysis of chromium (III) using pencil graphite electrode gave linear range at 12.5 to 75 ppm with limit of detection of 0.31 ppm.

Optimization of PEDOT films in ionic liquid supercapacitors: demonstration as a power source for polymer electrochromic devices.

PubMed

Österholm, Anna M; Shen, D Eric; Dyer, Aubrey L; Reynolds, John R

2013-12-26

We report on the optimization of the capacitive behavior of poly(3,4-ethylenedioxythiophene) (PEDOT) films as polymeric electrodes in flexible, Type I electrochemical supercapacitors (ESCs) utilizing ionic liquid (IL) and organic gel electrolytes. The device performance was assessed based on figures of merit that are critical to evaluating the practical utility of electroactive polymer ESCs. PEDOT/IL devices were found to be highly stable over hundreds of thousands of cycles and could be reversibly charged/discharged at scan rates between 500 mV/s and 2 V/s depending on the polymer loading. Furthermore, these devices exhibit leakage currents and self-discharge rates that are comparable to state of the art electrochemical double-layer ESCs. Using an IL as device electrolyte allowed an extension of the voltage window of Type I ESCs by 60%, resulting in a 2.5-fold increase in the energy density obtained. The efficacies of tjese PEDOT ESCs were assessed by using them as a power source for a high-contrast and fast-switching electrochromic device, demonstrating their applicability in small organic electronic-based devices.

Boron doped ZnO embedded into reduced graphene oxide for electrochemical supercapacitors

NASA Astrophysics Data System (ADS)

Alver, Ü.; Tanrıverdi, A.

2016-08-01

In this work, reduced graphene oxide/boron doped zinc oxide (RGO/ZnO:B) composites were fabricated by a hydrothermal process and their electrochemical properties were investigated as a function of dopant concentration. First, boron doped ZnO (ZnO:B) particles was fabricated with different boron concentrations (5, 10, 15 and 20 wt%) and then ZnO:B particles were embedded into RGO sheets. The physical properties of sensitized composites were characterized by XRD and SEM. Characterization indicated that the ZnO:B particles with plate-like structure in the composite were dispersed on graphene sheets. The electrochemical properties of the RGO/ZnO:B composite were investigated through cyclic voltammetry, galvanostatic charge/discharge measurements in a 6 M KOH electrolyte. Electrochemical measurements show that the specific capacitance values of RGO/ZnO:B electrodes increase with increasing boron concentration. RGO/ZnO:B composite electrodes (20 wt% B) display the specific capacitance as high as 230.50 F/g at 5 mV/s, which is almost five times higher than that of RGO/ZnO (52.71 F/g).

Achieving an adequate minute volume through a 2 mm transtracheal catheter in simulated upper airway obstruction using a modified industrial ejector.

PubMed

Hamaekers, A E W; Götz, T; Borg, P A J; Enk, D

2010-03-01

Needle cricothyrotomy and subsequent transtracheal jet ventilation (TTJV) is one of the last options to restore oxygenation while managing an airway emergency. However, in cases of complete upper airway obstruction, conventional TTJV is ineffective and dangerous. We transformed a small, industrial ejector into a simple, manual ventilator providing expiratory ventilation assistance (EVA). An ejector pump was modified to allow both insufflation of oxygen and jet-assisted expiration through an attached 75 mm long transtracheal catheter (TTC) with an inner diameter (ID) of 2 mm by alternately occluding and releasing the gas outlet of the ejector pump. In a lung simulator, the modified ejector pump was tested at different compliances and resistances. Inspiration and expiration times were measured and achievable minute volumes (MVs) were calculated to determine the effect of EVA. The modified ejector pump shortened the expiration time and an MV up to 6.6 litre min(-1) could be achieved through a 2 mm ID TTC in a simulated obstructed airway. The principle of ejector-based EVA seems promising and deserves further evaluation.

Archaeological Feature Detection from Archive Aerial Photography with a Sfm-Mvs and Image Enhancement Pipeline

NASA Astrophysics Data System (ADS)

Peppa, M. V.; Mills, J. P.; Fieber, K. D.; Haynes, I.; Turner, S.; Turner, A.; Douglas, M.; Bryan, P. G.

2018-05-01

Understanding and protecting cultural heritage involves the detection and long-term documentation of archaeological remains alongside the spatio-temporal analysis of their landscape evolution. Archive aerial photography can illuminate traces of ancient features which typically appear with different brightness values from their surrounding environment, but are not always well defined. This research investigates the implementation of the Structure-from-Motion - Multi-View Stereo image matching approach with an image enhancement algorithm to derive three epochs of orthomosaics and digital surface models from visible and near infrared historic aerial photography. The enhancement algorithm uses decorrelation stretching to improve the contrast of the orthomosaics so as archaeological features are better detected. Results include 2D / 3D locations of detected archaeological traces stored into a geodatabase for further archaeological interpretation and correlation with benchmark observations. The study also discusses the merits and difficulties of the process involved. This research is based on a European-wide project, entitled "Cultural Heritage Through Time", and the case study research was carried out as a component of the project in the UK.

Porous WO3/graphene/polyester textile electrode materials with enhanced electrochemical performance for flexible solid-state supercapacitors.

PubMed

Jin, Li-Na; Liu, Ping; Jin, Chun; Zhang, Jia-Nan; Bian, Shao-Wei

2018-01-15

In this work, a flexible and porous WO 3 /grapheme/polyester (WO 3 /G/PT) textile electrode was successfully prepared by in situ growing WO 3 on the fiber surface inside G/PT composite fabrics. The unique electrode structure facilitates to enhance the energy storage performance because the 3D conductive network constructed by the G/PT increase the electron transportation rate, nanotructured WO 3 exposed enhanced electrochemically active surface area and the hierarchically porous structure improved the electrolyte ion diffusion rate. The optimized WO 3 /G/PT textile electrode exhibited good electrochemical performance with a high areal capacitance of 308.2mFcm -2 at a scan rate of 2mVs -1 and excellent cycling stability. A flexible asymmetric supercapacitor (ASC) device was further fabricated by using the WO 3 /G/PT electrode and G/PT electrode, which exhibited a good specific capacitance of 167.6mFcm -3 and high energy density of 60μWhcm -3 at the power density of 2320 μWcm -3 . Copyright © 2017 Elsevier Inc. All rights reserved.

Activation of blood coagulation in cancer: implications for tumour progression

PubMed Central

Lima, Luize G.; Monteiro, Robson Q.

2013-01-01

Several studies have suggested a role for blood coagulation proteins in tumour progression. Herein, we discuss (1) the activation of the blood clotting cascade in the tumour microenvironment and its impact on primary tumour growth; (2) the intravascular activation of blood coagulation and its impact on tumour metastasis and cancer-associated thrombosis; and (3) antitumour therapies that target blood-coagulation-associated proteins. Expression levels of the clotting initiator protein TF (tissue factor) have been correlated with tumour cell aggressiveness. Simultaneous TF expression and PS (phosphatidylserine) exposure by tumour cells promote the extravascular activation of blood coagulation. The generation of blood coagulation enzymes in the tumour microenvironment may trigger the activation of PARs (protease-activated receptors). In particular, PAR1 and PAR2 have been associated with many aspects of tumour biology. The procoagulant activity of circulating tumour cells favours metastasis, whereas the release of TF-bearing MVs (microvesicles) into the circulation has been correlated with cancer-associated thrombosis. Given the role of coagulation proteins in tumour progression, it has been proposed that they could be targets for the development of new antitumour therapies. PMID:23889169

Rockfalls in cliffs surrounding waterfall revealed by high-definition topographic measurements

NASA Astrophysics Data System (ADS)

Hayakawa, Y. S.; Obanawa, H.

2017-12-01

Bedrock rivers of volcanic terrain often comprise numerous knickpoints. Erosion of bedrock at knickpoints is an essential process of fluvial dissection of volcanic landforms, which also affects the deformations of surrounding slopes. However, short term (less than decadal) changes in bedrock landforms have often been limited to examine in a spatiotemporal framework. Here we use terrestrial laser scanning and SfM-MVS photogrammetry to detect recent annual changes in the morphology of cliffs surrounding a waterfall (Kegon Falls) on jointed andesite lava and conglomerates. The amount of bedrock deformation caused by small rockfalls and surface lowering are assessed in volume, which often appears in a relatively lower portion of the cliff. Such the changes are supposed to be affected by the enhanced supply of water and weathering following the latest major rockfall in 1986 which caused 8-m recession of the waterfall lip. The three-dimensional point cloud data is also utilized to construct a 3D model using cardboards, which is useful for understanding the topography and its changes of the waterfall as educational resources.

Molecular Characterization of Wild Type Measles Virus from Adult Patients in Northern China, 2014.

PubMed

Xu, Wen; Zhang, Ming-Xiang; Qin, En-Qiang; Yan, Ying-Chun; Li, Feng-Yi; Xu, Zhe; Tian, Xia; Fan, Rong; Tu, Bo; Chen, Wei-Wei; Zhao, Min

2016-04-01

In this study, we studied the N and H genes from wild type measles viruses (MeVs) isolated during the 2013-2014 outbreak. Clinical samples were collected, and the genotyping, phylogenetic analysis were performed. The vaccination rate of the study population was 4%. Genotype H1a was the predominant genotype. Wild type viruses were classified into clusters A and B, C and may have different origins. N-450 sequences from wild type viruses were highly homologous with, and likely evolved from MeVs circulating in Tianjing and Henan in 2012. MVs/Shenyang.CHN/18.14/3 could have evolved from MeVs from Liaoning, Beijing, Hebei, Heilongjiang, Henan, Jilin, and Tianjin. Our data suggested that one or more of the same viruses circulated between Beijing, Shenyang, Hong Kong, Taiwan and Berlin. Important factors contributing to outbreaks could include weak vaccination coverage, poor vaccination strategies, and migration of adult workers between cities, countries, and from rural areas to urban areas. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Tumor-secreted miR-214 induces regulatory T cells: a major link between immune evasion and tumor growth

PubMed Central

Yin, Yuan; Cai, Xing; Chen, Xi; Liang, Hongwei; Zhang, Yujing; Li, Jing; Wang, Zuoyun; Chen, Xiulan; Zhang, Wen; Yokoyama, Seiji; Wang, Cheng; Li, Liang; Li, Limin; Hou, Dongxia; Dong, Lei; Xu, Tao; Hiroi, Takachika; Yang, Fuquan; Ji, Hongbin; Zhang, Junfeng; Zen, Ke; Zhang, Chen-Yu

2014-01-01

An increased population of CD4+CD25highFoxp3+ regulatory T cells (Tregs) in the tumor-associated microenvironment plays an important role in cancer immune evasion. However, the underlying mechanism remains unclear. Here we observed an increased secretion of miR-214 in various types of human cancers and mouse tumor models. Tumor-secreted miR-214 was sufficiently delivered into recipient T cells by microvesicles (MVs). In targeted mouse peripheral CD4+ T cells, tumor-derived miR-214 efficiently downregulated phosphatase and tensin homolog (PTEN) and promoted Treg expansion. The miR-214-induced Tregs secreted higher levels of IL-10 and promoted tumor growth in nude mice. Furthermore, in vivo studies indicated that Treg expansion mediated by cancer cell-secreted miR-214 resulted in enhanced immune suppression and tumor implantation/growth in mice. The MV delivery of anti-miR-214 antisense oligonucleotides (ASOs) into mice implanted with tumors blocked Treg expansion and tumor growth. Our study reveals a novel mechanism through which cancer cell actively manipulates immune response via promoting Treg expansion. PMID:25223704

Association of Focal Radiation Dose Adjusted on Cross Sections with Subsolid Nodule Visibility and Quantification on Computed Tomography Images Using AIDR 3D: Comparison Among Scanning at 84, 42, and 7 mAs.

PubMed

Nagatani, Yukihiro; Moriya, Hiroshi; Noma, Satoshi; Sato, Shigetaka; Tsukagoshi, Shinsuke; Yamashiro, Tsuneo; Koyama, Mitsuhiro; Tomiyama, Noriyuki; Ono, Yoshiharu; Murayama, Sadayuki; Murata, Kiyoshi

2018-05-04

The objectives of this study were to compare the visibility and quantification of subsolid nodules (SSNs) on computed tomography (CT) using adaptive iterative dose reduction using three-dimensional processing between 7 and 42 mAs and to assess the association of size-specific dose estimate (SSDE) with relative measured value change between 7 and 84 mAs (RMVC 7-84 ) and relative measured value change between 42 and 84 mAs (RMVC 42-84 ). As a Japanese multicenter research project (Area-detector Computed Tomography for the Investigation of Thoracic Diseases [ACTIve] study), 50 subjects underwent chest CT with 120 kV, 0.35 second per location and three tube currents: 240 mA (84 mAs), 120 mA (42 mAs), and 20 mA (7 mAs). Axial CT images were reconstructed using adaptive iterative dose reduction using three-dimensional processing. SSN visibility was assessed with three grades (1, obscure, to 3, definitely visible) using CT at 84 mAs as reference standard and compared between 7 and 42 mAs using t test. Dimension, mean CT density, and particular SSDE to the nodular center of 71 SSNs and volume of 58 SSNs (diameter >5 mm) were measured. Measured values (MVs) were compared using Wilcoxon signed-rank tests among CTs at three doses. Pearson correlation analyses were performed to assess the association of SSDE with RMVC 7-84 : 100 × (MV at 7 mAs - MV at 84 mAs)/MV at 84 mAs and RMVC 42-84 . SSN visibilities were similar between 7 and 42 mAs (2.76 ± 0.45 vs 2.78 ± 0.40) (P = .67). For larger SSNs (>8 mm), MVs were similar among CTs at three doses (P > .05). For smaller SSNs (<8 mm), dimensions and volumes on CT at 7 mAs were larger and the mean CT density was smaller than 42 and 84 mAs, and SSDE had mild negative correlations with RMVC 7-84 (P < .05). Comparable quantification was demonstrated irrespective of doses for larger SSNs. For smaller SSNs, nodular exaggerating effect associated with decreased SSDE on CT at 7 mAs compared to 84 mAs could result in comparable visibilities to CT at 42 mAs. Copyright © 2018 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.

One-pot hydrothermal synthesis, characterization, and electrochemical properties of rGO/MnFe2O4 nanocomposites

NASA Astrophysics Data System (ADS)

Kotutha, Isara; Swatsitang, Ekaphan; Meewassana, Worawat; Maensiri, Santi

2015-06-01

In this work, a simple facile route for preparing an rGO/MnFe2O4 nanocomposite through a one-pot hydrothermal approach was demonstrated. Graphite oxide (GO) was prepared from graphite powder by a modified Hummers method. Fe(NO3)2 • 9H2O and Mn(NO3)2 • H2O were used as the precursors for the preparation of the rGO/MnFe2O4 nanocomposite. The formation of the rGO/MnFe2O4 nanocomposite was confirmed by X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), and Rama spectroscopy (Raman). The specific surface area of the prepared composite obtained by Brunauer-Emmett-Teller (BET) analysis was lower than that of pure rGO but higher than that of pure MnFe2O4. Consequently, the electrochemical performance was investigated by using a three-electrode cell system in 6.0 M KOH. The results show that the specific capacitance was determined to be 190.3, 276.9, and 144.5 F/g at a scan rate of 10 mV/s, and 194.9, 274.6, and 134.4 F/g at a current density of 5.0 A/g for rGO, rGO/(5 mmol) MnFe2O4, and rGO/(10 mmol) MnFe2O4, respectively. These results suggest that the composite of MnFe2O4 nanoparticles on an rGO nanosheet can improve the capacitive behavior of the fabricated electrode, but the electrochemical properties are reduced when the MnFe2O4 concentration ratio is high.

Morphogen Electrochemically Triggered Self-Construction of Polymeric Films Based on Mussel-Inspired Chemistry.

PubMed

Maerten, Clément; Garnier, Tony; Lupattelli, Paolo; Chau, Nguyet Trang Thanh; Schaaf, Pierre; Jierry, Loïc; Boulmedais, Fouzia

2015-12-15

Inspired by the strong chemical adhesion mechanism of mussels, we designed a catechol-based electrochemically triggered self-assembly of films based on ethylene glycol molecules bearing catechol groups on both sides and denoted as bis-catechol molecules. These molecules play the role of morphogens and, in contrast to previously investigated systems, they are also one of the constituents, after reaction, of the film. Unable to interact together, commercially available poly(allylamine hydrochloride) (PAH) chains and bis-catechol molecules are mixed in an aqueous solution and brought in contact with an electrode. By application of defined potential cycles, bis-catechol molecules undergo oxidation leading to molecules bearing "reactive" quinone groups which diffuse toward the solution. In this active state, the quinones react with amino groups of PAH through Michael addition and Schiff's base condensation reaction. The application of cyclic voltammetry (CV) between 0 and 500 mV (vs Ag/AgCl, scan rate of 50 mV/s) of a PAH/bis-catechol solution results in a fast self-construction of a film that reaches a thickness of 40 nm after 60 min. The films present a spiky structure which is attributed to the use of bis-functionalized molecules as one component of the films. XPS measurements show the presence of both PAH and bis-catechol cross-linked together in a covalent way. We show that the amine/catechol ratio is an important parameter which governs the film buildup. For a given amine/catechol ratio, it does exist an optimum CV scan rate leading to a maximum of the film thickness as a function of the scan rate.

RF Magnetron Sputtering Deposited W/Ti Thin Film For Smart Window Applications

NASA Astrophysics Data System (ADS)

Oksuz, Lutfi; Kiristi, Melek; Bozduman, Ferhat; Uygun Oksuz, Aysegul

2014-10-01

Electrochromic (EC) devices can change reversible and persistent their optical properties in the visible region (400-800 nm) upon charge insertion/extraction according to the applied voltage. A complementary type EC is a device containing two electrochromic layers, one of which is anodically colored such as vanadium oxide (V2 O5) while the other cathodically colored such as tungsten oxide (WO3) which is separated by an ionic conduction layer (electrolyte). The use of a solid electrolyte such as Nafion eliminates the need for containment of the liquid electrolyte, which simplifies the cell design, as well as improves safety and durability. In this work, the EC device was fabricated on a ITO/glass slide. The WO3-TiO2 thin film was deposited by reactive RF magnetron sputtering using a 2-in W/Ti (9:1%wt) target with purity of 99.9% in a mixture gas of argon and oxygen. As a counter electrode layer, V2O5 film was deposited on an ITO/glass substrate using V2O3 target with the same conditions of reactive RF magnetron sputtering. Modified Nafion was used as an electrolyte to complete EC device. The transmittance spectra of the complementary EC device was measured by optical spectrophotometry when a voltage of +/-3 V was applied to the EC device by computer controlled system. The surface morphology of the films was characterized by scanning electron microscopy (SEM) and atomic force microscopy (AFM) (Fig. 2). The cyclic voltammetry (CV) for EC device was performed by sweeping the potential between +/-3 V at a scan rate of 50 mV/s.

Epitope Dampening Monotypic Measles Virus Hemagglutinin Glycoprotein Results in Resistance to Cocktail of Monoclonal Antibodies

PubMed Central

Lech, Patrycja J.; Tobin, Gregory J.; Bushnell, Ruth; Gutschenritter, Emily; Pham, Linh D.; Nace, Rebecca; Verhoeyen, Els; Cosset, François-Loïc; Muller, Claude P.; Russell, Stephen J.; Nara, Peter L.

2013-01-01

The measles virus (MV) is serologically monotypic. Life-long immunity is conferred by a single attack of measles or following vaccination with the MV vaccine. This is contrary to viruses such as influenza, which readily develop resistance to the immune system and recur. A better understanding of factors that restrain MV to one serotype may allow us to predict if MV will remain monotypic in the future and influence the design of novel MV vaccines and therapeutics. MV hemagglutinin (H) glycoprotein, binds to cellular receptors and subsequently triggers the fusion (F) glycoprotein to fuse the virus into the cell. H is also the major target for neutralizing antibodies. To explore if MV remains monotypic due to a lack of plasticity of the H glycoprotein, we used the technology of Immune Dampening to generate viruses with rationally designed N-linked glycosylation sites and mutations in different epitopes and screened for viruses that escaped monoclonal antibodies (mAbs). We then combined rationally designed mutations with naturally selected mutations to generate a virus resistant to a cocktail of neutralizing mAbs targeting four different epitopes simultaneously. Two epitopes were protected by engineered N-linked glycosylations and two epitopes acquired escape mutations via two consecutive rounds of artificial selection in the presence of mAbs. Three of these epitopes were targeted by mAbs known to interfere with receptor binding. Results demonstrate that, within the epitopes analyzed, H can tolerate mutations in different residues and additional N-linked glycosylations to escape mAbs. Understanding the degree of change that H can tolerate is important as we follow its evolution in a host whose immunity is vaccine induced by genotype A strains instead of multiple genetically distinct wild-type MVs. PMID:23300970

Morphological analysis of hummocks in debris avalanche deposits using UAS-derived high-definition topographic data

NASA Astrophysics Data System (ADS)

Hayakawa, Yuichi S.; Obanawa, Hiroyuki; Yoshida, Hidetsugu; Naruhashi, Ryutaro; Okumura, Koji; Zaiki, Masumi

2016-04-01

Debris avalanche caused by sector collapse of a volcanic mountain often forms depositional landforms with characteristic surface morphology comprising hummocks. Geomorphological and sedimentological analyses of debris avalanche deposits (DAD) at the northeastern face of Mt. Erciyes in central Turkey have been performed to investigate the mechanisms and processes of the debris avalanche. The morphometry of hummocks provides an opportunity to examine the volumetric and kinematic characteristics of the DAD. Although the exact age has been unknown, the sector collapse of this DAD was supposed to have occurred in the late Pleistocene (sometime during 90-20 ka), and subsequent sediment supply from the DAD could have affected ancient human activities in the downstream basin areas. In order to measure detailed surface morphology and depositional structures of the DAD, we apply structure-from-motion multi-view stereo (SfM-MVS) photogrammetry using unmanned aerial system (UAS) and a handheld camera. The UAS, including small unmanned aerial vehicle (sUAV) and a digital camera, provides low-altitude aerial photographs to capture surface morphology for an area of several square kilometers. A high-resolution topographic data, as well as an orthorectified image, of the hummocks were then obtained from the digital elevation model (DEM), and the geometric features of the hummocks were examined. A handheld camera is also used to obtain photographs of outcrop face of the DAD along a road to support the seimentological investigation. The three-dimensional topographic models of the outcrop, with a panoramic orthorectified image projected on a vertical plane, were obtained. This data enables to effectively describe sedimentological structure of the hummock in DAD. The detailed map of the DAD is also further examined with a regional geomorphological map to be compared with other geomorphological features including fluvial valleys, terraces, lakes and active faults.

Highly Durable Supportless Pt Hollow Spheres Designed for Enhanced Oxygen Transport in Cathode Catalyst Layers of Proton Exchange Membrane Fuel Cells.

PubMed

Dogan, Didem C; Cho, Seonghun; Hwang, Sun-Mi; Kim, Young-Min; Guim, Hwanuk; Yang, Tae-Hyun; Park, Seok-Hee; Park, Gu-Gon; Yim, Sung-Dae

2016-10-10

Supportless Pt catalysts have several advantages over conventional carbon-supported Pt catalysts in that they are not susceptible to carbon corrosion. However, the need for high Pt loadings in membrane electrode assemblies (MEAs) to achieve state-of-the-art fuel cell performance has limited their application in proton exchange membrane fuel cells. Herein, we report a new approach to the design of a supportless Pt catalyst in terms of catalyst layer architecture, which is crucial for fuel cell performance as it affects water management and oxygen transport in the catalyst layers. Large Pt hollow spheres (PtHSs) 100 nm in size were designed and prepared using a carbon template method. Despite their large size, the unique structure of the PtHSs, which are composed of a thin-layered shell of Pt nanoparticles (ca. 7 nm thick), exhibited a high surface area comparable to that of commercial Pt black (PtB). The PtHS structure also exhibited twice the durability of PtB after 2000 potential cycles (0-1.3 V, 50 mV/s). A MEA fabricated with PtHSs showed significant improvement in fuel cell performance compared to PtB-based MEAs at high current densities (>800 mA/cm 2 ). This was mainly due to the 2.7 times lower mass transport resistance in the PtHS-based catalyst layers compared to that in PtB, owing to the formation of macropores between the PtHSs and high porosity (90%) in the PtHS catalyst layers. The present study demonstrates a successful example of catalyst design in terms of catalyst layer architecture, which may be applied to a real fuel cell system.

Lung assist devices influence cardio-energetic parameters: Numerical simulation study.

PubMed

De Lazzari, C; Quatember, B; Recheis, W; Mayr, M; Demertzis, S; Allasia, G; De Rossi, A; Cavoretto, R; Venturino, E; Genuini, I

2015-08-01

We aim at an analysis of the effects mechanical ventilators (MVs) and thoracic artificial lungs (TALs) will have on the cardiovascular system, especially on important quantities, such as left and right ventricular external work (EW), pressure-volume area (PVA) and cardiac mechanical efficiency (CME). Our analyses are based on simulation studies which were carried out by using our CARDIOSIM(©) software simulator. At first, we carried out simulation studies of patients undergoing mechanical ventilation (MV) without a thoracic artificial lung (TAL). Subsequently, we conducted simulation studies of patients who had been provided with a TAL, but did not undergo MV. We aimed at describing the patient's physiological characteristics and their variations with time, such as EW, PVA, CME, cardiac output (CO) and mean pulmonary arterial/venous pressure (PAP/PVP). We were starting with a simulation run under well-defined initial conditions which was followed by simulation runs for a wide range of mean intrathoracic pressure settings. Our simulations of MV without TAL showed that for mean intrathoracic pressure settings from negative (-4 mmHg) to positive (+5 mmHg) values, the left and right ventricular EW and PVA, right ventricular CME and CO decreased, whereas left ventricular CME and the PAP increased. The simulation studies of patients with a TAL, comprised all the usual TAL arrangements, viz. configurations "in series" and in parallel with the natural lung and, moreover, hybrid configurations. The main objective of the simulation studies was, as before, the assessment of the hemodynamic response to the application of a TAL. We could for instance show that, in case of an "in series" configuration, a reduction (an increase) in left (right) ventricular EW and PVA values occurred, whereas the best performance in terms of CO can be achieved in the case of an in parallel configuration.

Pathological consequences of systemic measles virus infection.

PubMed

Ludlow, Martin; McQuaid, Stephen; Milner, Dan; de Swart, Rik L; Duprex, W Paul

2015-01-01

The identification of poliovirus receptor-like 4 (PVRL4) as the second natural receptor for measles virus (MV) has closed a major gap in our understanding of measles pathogenesis, and explains how this predominantly lymphotropic virus breaks through epithelial barriers to transmit to a susceptible host. Advances in the development of wild-type, recombinant MVs which express fluorescent proteins making infected cells readily detectable in living tissues and animals, has also increased our understanding of this important and highly transmissible human disease. Thus, it is timely to review how these advances have provided new insights into MV infection of immune, epithelial and neural cells. This demands access to primate samples that help us understand the early and acute stages of the disease, which are challenging to dissect due to the mild/self-limiting nature of the infection. It also requires well-characterized and rather rare human tissue samples from patients who succumb to neurological sequelae to help study the consequences of the long-term persistence of this RNA virus in vivo. Collectively, these studies have provided unique insights into how the use of two cellular receptors, CD150 and PVRL4, governs the in vivo tissue-specific temporal patterns of virus spread and resulting pathological lesions. Analysis of tissue samples has also demonstrated the importance of differing mechanisms of virus cell-to-cell spread within lymphoid, epithelial and neural tissues in the dissemination of MV during acute and long-term persistent infections. Given the incentive to eradicate MV globally, and the inevitable question as to whether or not vaccination should cease in light of the existence of closely related morbilliviruses, a thorough understanding of measles pathological lesions is essential. Copyright © 2014 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

INS3D - NUMERICAL SOLUTION OF THE INCOMPRESSIBLE NAVIER-STOKES EQUATIONS IN THREE-DIMENSIONAL GENERALIZED CURVILINEAR COORDINATES (DEC RISC ULTRIX VERSION)

NASA Technical Reports Server (NTRS)

Biyabani, S. R.

1994-01-01

INS3D computes steady-state solutions to the incompressible Navier-Stokes equations. The INS3D approach utilizes pseudo-compressibility combined with an approximate factorization scheme. This computational fluid dynamics (CFD) code has been verified on problems such as flow through a channel, flow over a backwardfacing step and flow over a circular cylinder. Three dimensional cases include flow over an ogive cylinder, flow through a rectangular duct, wind tunnel inlet flow, cylinder-wall juncture flow and flow through multiple posts mounted between two plates. INS3D uses a pseudo-compressibility approach in which a time derivative of pressure is added to the continuity equation, which together with the momentum equations form a set of four equations with pressure and velocity as the dependent variables. The equations' coordinates are transformed for general three dimensional applications. The equations are advanced in time by the implicit, non-iterative, approximately-factored, finite-difference scheme of Beam and Warming. The numerical stability of the scheme depends on the use of higher-order smoothing terms to damp out higher-frequency oscillations caused by second-order central differencing. The artificial compressibility introduces pressure (sound) waves of finite speed (whereas the speed of sound would be infinite in an incompressible fluid). As the solution converges, these pressure waves die out, causing the derivation of pressure with respect to time to approach zero. Thus, continuity is satisfied for the incompressible fluid in the steady state. Computational efficiency is achieved using a diagonal algorithm. A block tri-diagonal option is also available. When a steady-state solution is reached, the modified continuity equation will satisfy the divergence-free velocity field condition. INS3D is capable of handling several different types of boundaries encountered in numerical simulations, including solid-surface, inflow and outflow, and far-field boundaries. Three machine versions of INS3D are available. INS3D for the CRAY is written in CRAY FORTRAN for execution on a CRAY X-MP under COS, INS3D for the IBM is written in FORTRAN 77 for execution on an IBM 3090 under the VM or MVS operating system, and INS3D for DEC RISC-based systems is written in RISC FORTRAN for execution on a DEC workstation running RISC ULTRIX 3.1 or later. The CRAY version has a central memory requirement of 730279 words. The central memory requirement for the IBM is 150Mb. The memory requirement for the DEC RISC ULTRIX version is 3Mb of main memory. INS3D was developed in 1987. The port to the IBM was done in 1990. The port to the DECstation 3100 was done in 1991. CRAY is a registered trademark of Cray Research Inc. IBM is a registered trademark of International Business Machines. DEC, DECstation, and ULTRIX are trademarks of the Digital Equipment Corporation.

INS3D - NUMERICAL SOLUTION OF THE INCOMPRESSIBLE NAVIER-STOKES EQUATIONS IN THREE-DIMENSIONAL GENERALIZED CURVILINEAR COORDINATES (CRAY VERSION)

NASA Technical Reports Server (NTRS)

Rogers, S. E.

1994-01-01

INS3D computes steady-state solutions to the incompressible Navier-Stokes equations. The INS3D approach utilizes pseudo-compressibility combined with an approximate factorization scheme. This computational fluid dynamics (CFD) code has been verified on problems such as flow through a channel, flow over a backwardfacing step and flow over a circular cylinder. Three dimensional cases include flow over an ogive cylinder, flow through a rectangular duct, wind tunnel inlet flow, cylinder-wall juncture flow and flow through multiple posts mounted between two plates. INS3D uses a pseudo-compressibility approach in which a time derivative of pressure is added to the continuity equation, which together with the momentum equations form a set of four equations with pressure and velocity as the dependent variables. The equations' coordinates are transformed for general three dimensional applications. The equations are advanced in time by the implicit, non-iterative, approximately-factored, finite-difference scheme of Beam and Warming. The numerical stability of the scheme depends on the use of higher-order smoothing terms to damp out higher-frequency oscillations caused by second-order central differencing. The artificial compressibility introduces pressure (sound) waves of finite speed (whereas the speed of sound would be infinite in an incompressible fluid). As the solution converges, these pressure waves die out, causing the derivation of pressure with respect to time to approach zero. Thus, continuity is satisfied for the incompressible fluid in the steady state. Computational efficiency is achieved using a diagonal algorithm. A block tri-diagonal option is also available. When a steady-state solution is reached, the modified continuity equation will satisfy the divergence-free velocity field condition. INS3D is capable of handling several different types of boundaries encountered in numerical simulations, including solid-surface, inflow and outflow, and far-field boundaries. Three machine versions of INS3D are available. INS3D for the CRAY is written in CRAY FORTRAN for execution on a CRAY X-MP under COS, INS3D for the IBM is written in FORTRAN 77 for execution on an IBM 3090 under the VM or MVS operating system, and INS3D for DEC RISC-based systems is written in RISC FORTRAN for execution on a DEC workstation running RISC ULTRIX 3.1 or later. The CRAY version has a central memory requirement of 730279 words. The central memory requirement for the IBM is 150Mb. The memory requirement for the DEC RISC ULTRIX version is 3Mb of main memory. INS3D was developed in 1987. The port to the IBM was done in 1990. The port to the DECstation 3100 was done in 1991. CRAY is a registered trademark of Cray Research Inc. IBM is a registered trademark of International Business Machines. DEC, DECstation, and ULTRIX are trademarks of the Digital Equipment Corporation.

Synthesis and characterization of Co3O4 prepared from atmospheric pressure acid leach liquors of nickel laterite ores

NASA Astrophysics Data System (ADS)

Meng, Long; Guo, Zhan-cheng; Qu, Jing-kui; Qi, Tao; Guo, Qiang; Hou, Gui-hua; Dong, Peng-yu; Xi, Xin-guo

2018-01-01

A chemical precipitation-thermal decomposition method was developed to synthesize Co3O4 nanoparticles using cobalt liquor obtained from the atmospheric pressure acid leaching process of nickel laterite ores. The effects of the precursor reaction temperature, the concentration of Co2+, and the calcination temperature on the specific surface area, morphology, and the electrochemical behavior of the obtained Co3O4 particles were investigated. The precursor basic cobaltous carbonate and cobaltosic oxide products were characterized and analyzed by Fourier transform infrared spectroscopy, thermogravimetric differential thermal analysis, X-ray diffraction, field-emission scanning electron microscopy, specific surface area analysis, and electrochemical analysis. The results indicate that the specific surface area of the Co3O4 particles with a diameter of 30 nm, which were obtained under the optimum conditions of a precursor reaction temperature of 30°C, 0.25 mol/L Co2+, and a calcination temperature of 350°C, was 48.89 m2/g. Electrodes fabricated using Co3O4 nanoparticles exhibited good electrochemical properties, with a specific capacitance of 216.3 F/g at a scan rate of 100 mV/s.

Direct electrochemical reduction of solid uranium oxide in molten fluoride salts

NASA Astrophysics Data System (ADS)

Gibilaro, Mathieu; Cassayre, Laurent; Lemoine, Olivier; Massot, Laurent; Dugne, Olivier; Malmbeck, Rikard; Chamelot, Pierre

2011-07-01

The direct electrochemical reduction of UO 2 solid pellets was carried out in LiF-CaF 2 (+2 mass.% Li 2O) at 850 °C. An inert gold anode was used instead of the usual reactive sacrificial carbon anode. In this case, oxidation of oxide ions present in the melt yields O 2 gas evolution on the anode. Electrochemical characterisations of UO 2 pellets were performed by linear sweep voltammetry at 10 mV/s and reduction waves associated to oxide direct reduction were observed at a potential 150 mV more positive in comparison to the solvent reduction. Subsequent, galvanostatic electrolyses runs were carried out and products were characterised by SEM-EDX, EPMA/WDS, XRD and microhardness measurements. In one of the runs, uranium oxide was partially reduced and three phases were observed: nonreduced UO 2 in the centre, pure metallic uranium on the external layer and an intermediate phase representing the initial stage of reduction taking place at the grain boundaries. In another run, the UO 2 sample was fully reduced. Due to oxygen removal, the U matrix had a typical coral-like structure which is characteristic of the pattern observed after the electroreduction of solid oxides.

Flexible Asymmetrical Solid-State Supercapacitors Based on Laboratory Filter Paper.

PubMed

Zhang, Leicong; Zhu, Pengli; Zhou, Fengrui; Zeng, Wenjin; Su, Haibo; Li, Gang; Gao, Jihua; Sun, Rong; Wong, Ching-Ping

2016-01-26

In this study, a flexible asymmetrical all-solid-state supercapacitor with high electrochemical performance was fabricated with Ni/MnO2-filter paper (FP) as the positive electrode and Ni/active carbon (AC)-filter paper as negative electrode, separated with poly(vinyl alcohol) (PVA)-Na2SO4 electrolyte. A simple procedure, such as electroless plating, was introduced to prepare the Ni/MnO2-FP electrode on the conventional laboratory FP, combined with the subsequent step of electrodeposition. Electrochemical results show that the as-prepared electrodes display outstanding areal specific capacitance (1900 mF/cm(2) at 5 mV/s) and excellent cycling performance (85.1% retention after 1000 cycles at 20 mA/cm(2)). Such a flexible supercapacitor assembled asymmetrically in the solid state exhibits a large volume energy density (0.78 mWh/cm(3)) and superior flexibility under different bending conditions. It has been demonstrated that the supercapacitors could be used as a power source to drive a 3 V light-emitting diode indicator. This study may provide an available method for designing and fabricating flexible supercapacitors with high performance in the application of wearable and portable electronics based on easily available materials.

Comparative study on polyvinyl chloride film as flexible substrate for preparing free-standing polyaniline-based composite electrodes for supercapacitors.

PubMed

Wang, Hongxing; Liu, Dong; Du, Pengcheng; Wei, Wenli; Wang, Qi; Liu, Peng

2017-11-15

The free-standing polyaniline (PANI)-based composite film electrodes were prepared with polyvinyl chloride (PVC) and the aniline modified PVC (PVC-An) films as flexible substrates for supercapacitors, via facile in-situ chemical oxidative polymerization of aniline, with conventional chemical oxidative polymerization or rapid-mixing chemical oxidative polymerization technique. Owing to the grafting of PANI from the PVC-An film as substrate and the suppression of the secondary growth of the primary PANI particles in the rapid-mixing chemical oxidative polymerization, the PVC-g-PANI-2 composite film with loose surface possessed better comprehensive performance, accompanying the high specific capacitance (645.3F/g at a current density of 1A/g), good rate capacitance (retaining 63.2% of original value at a current density of 10A/g and 52.0% at a scan rate of 100mV/s), good cycle stability (retaining 83.1% after 1000 cycles) and the improved internal resistance. Besides its excellent flexibility, it could retain 61.2% of its original specific capacitance under the stress of 8.66MPa for 1h, demonstrating a good tensile-resistance. Copyright © 2017 Elsevier Inc. All rights reserved.

Waste tire derived carbon-polymer composite paper as pseudocapacitive electrode with long cycle life

DOE PAGES

Boota, M.; Paranthaman, Mariappan Parans; Naskar, Amit K.; ...

2015-09-25

Recycling hazardous wastes to produce value-added products is becoming essential for the sustainable progress of our society. Herein, highly porous carbon (1625 m 2/g –1) is synthesized using waste tires as the precursor and used as supercapacitor electrode. The narrow pore size distribution (PSD) and high surface area led to a good charge storage capacity, especially when used as a three-dimensional nanoscaffold to polymerize polyaniline (PANI/TC). The composite film was highly flexible, conductive and exhibited a capacitance of 480 F/g –1 at 1 mV/s –1 with excellent capacitance retention up to 98% after 10,000 charge/discharge cycles. The high capacitance andmore » long cycle life were ascribed to the short diffusional paths, uniform PANI coating and tight confinement of the PANI in the inner pores of the tire-derived carbon via - interactions, which minimized the degradation of the PANI upon cycling. Here, we anticipate that the same strategy can be applied to deposit other pseudocapacitive materials with low-cost TC to achieve even higher electrochemical performance and longer cycle life, a key challenge for redox active polymers.« less

Facile One-Pot Synthesis of Flower Like Cobalt Oxide Nanostructures on Nickel Plate and Its Supercapacitance Properties.

PubMed

Kandasamy, N; Venugopal, T; Kannan, K

2018-06-01

A flower like cobalt oxide nanostructured thin film (Co2O3) on Nickel (Ni) plate as have been successfully developed via alcoholic Seed Layer assisted chemical bath Deposition (SLD) process. Through the controlled alkaline electrolytes, the flower and paddles like Co2O3 nanoarchitectures were formed. The prepared thin film was characterized by X-ray diffraction (XRD), scanning electron microscope with energy dispersive X-ray (SEM and EDX), Atomic Force Microscope (AFM), Raman spectroscopy techniques. Electron micrograph reveals the flower and paddles like nanostructured Co2O3 thin film deposited on Ni plates. The electrochemical characteristics were investigated using cyclic voltammetry (CV), charge-discharge and AC impedance spectroscopy in different aqueous electrolytes such as NaOH, KOH, and LiOH. The maximum specific capacitance of 856 Fg-1 was attained with 2 M KOH electrolyte with 2 mVs-1 of the Co2O3 thin film coated Ni plate at 80 °C using SLD method. The capacitance values obtained with various electrolytes are in the order of KOH > NaOH > LiOH. The results indicate that the present method is economical and the material is ecofriendly with enhanced capacitance property.

Study of the voltammetric behaviour of the ethalfluralin and methalpropalin and its determination in environmental matrices at hanging mercury drop electrode.

PubMed

Thriveni, T; Kumar, J Rajesh; Lee, Jin Young; Sreedhar, N Y

2009-04-01

An electroanalytical method has been developed for the determination of the herbicides ethalfluralin[N-ethyl-N-(2-methyl-2-propenyl)-2,6-dinitro-4-(trifluoromethyl) bezenamine] and methalpropalin [N-(2-methyl-2-propenyl)-2, 6-dinitro-N-propyl-4 (trifluoromethyl) benzenamine] by differential pulse adsorptive stripping voltammetry (DP-AdSV) on a hanging mercury drop electrode (HMDE) with universal buffer as supporting electrolyte. The optimum adsorption conditions were found to be pH 6.0, an accumulation potential of -0.6 V (HMDE vs SCE), an accumulation time of 80 s. and scan rate 45 mVs(-1). Calibration curve is linear in the range 1.30 x 10(-9) to 1.32 x 10(-5) M of ethalfluralin and 1.13 x 10(-5) to 2.0 x 10(-8) M of methalpropalin with detection limits of 1.08 x 10(-9) and 1.87 x 10(-8) M, respectively. The relative SD and correlation coefficients were found to be 1.24%, 0.998 and 1.34%, 0.995, respectively for ten replicates. The method is applied to the determination of the ethalfluralin and methalpropalin in formulations and environmental matrices.

Conductivity enhancement of carbon aerogel by modified gelation using self additive

NASA Astrophysics Data System (ADS)

Singh, Ashish; Kohli, D. K.; Bhartiya, Sushmita; Singh, Rashmi; Rajak, Gaurav; Singh, M. K.; Karnal, A. K.

2018-04-01

Carbon aerogels having high surface area and open pore structure are being studied for many electrochemical applications such as fuel cells and super capacitors. Moderate electrical conductivity of resorcinol - formaldehyde (R-F) derived carbon aerogel limits its utility in these applications. The current manuscript briefs about the synthesis of composite carbon aerogel using carbon aerogel itself as additive during gelation of water based carbon aerogel and study the effect on its conductivity and surface properties. The additive carbon aerogel was synthesized and pre-treated at higher temperature to achieve enhancement in conductivity. The composite carbon aerogel (CCA) samples were characterized for surface area properties, morphology, electrical conductivity and specific capacitance. The surface area properties of CCA showed improvement and specific surface area of ˜1798 m2/g with total pore volume of 1.7 cm3/g. was obtained. The electrical conductivity of the composite carbon aerogel with 5 wt % additive showed improvement over the plain carbon aerogel with respective values of 144 S/m and 128 S/m. The specific capacitance evaluated for CA and CCA are 102 and 118 F/g at scan rate of 10mV/s with improvement of ˜16%.

Combustion Synthesis of Graphene from Waste Paper for High Performance Supercapacitor Electrodes

NASA Astrophysics Data System (ADS)

Singu, Dayakar Chowdary; Joseph, B.; Velmurugan, V.; Ravuri, Syamsai; Grace, A. Nirmala

Incessant streak of unsuccessful attempts to synthesize low cost graphene with larger flake size and purity is frequently reported. Any reported methods that result in few layers of graphene with minimal contamination are definitive to exist. In this work, graphene was prepared economically from source of “paper” and detailed investigation was done on the effect of synthesizing parameters like paper source, temperature and amount of urea in the formation of graphene. This is a cost effective method, in which the paper that we use in our daily life was carbonized with the help of urea at a temperature of 850∘C under N2 atmosphere. The paper source was varied, shape of the paper was altered and the graphene paper with large surface area was synthesized without smudging and the prepared graphene paper was analyzed by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) for its structural, morphological investigation. To test the supercapacitance performance, electrochemical behavior was investigated in 6M KOH electrolyte. The specific capacitance of 1122F/g was obtained at 5mV/s scan rate. Chronopotentiometry curves showed an excellent cyclic stability with higher charge/discharge duration and hence could be used for electrochemical supercapacitor applications.

Preparation of Pt/polypyrrole-para toluene sulfonate hydrogen peroxide sensitive electrode for the utilizing as a biosensor.

PubMed

Çete, Servet; Bal, Özgür

2013-12-01

A film electrode with electropolymerization of pyrrole (Py) and para-toluene sulfonate (pTS) as a anionic dopant is prepared and its sensitivity to hydrogen peroxide is investigated. The polypyrrole is deposited on a 0.5 cm(2) Pt plate an electrochemically prepared pTS ion-doped polypyrrole film by scanning the electrode potential between - 0.8 and + 0.8 V at a scan rate of 20 mV/s. The electrode's sensitivity to hydrogen peroxide is investigated at room temperature using 0.1 M phosphate buffer at pH 7.5. The working potential is found as a 0.3 V. The concentrations of pyrrole and pTS are 50mM M and 25 mM. Polypyrrole was coated on the electrode surface within 10 cycles. İmmobilization of glucose oxidase carried out on Pt/polypyrrole-para toluene sulfonate (Pt/PPy-pTS) film by cross-linking with glutaraldehyde. The morphology of electrodes was characterized by SEM and AFM. Moreover, contact angle measurements were made with 1 μL water of polymer film and enzyme electrode. It has shown that enzyme electrode is very sensitive against to glucose.

Morphology evaluation of ZrO2 dip coating on mild steel and its corrosion performance in NaOH solution

NASA Astrophysics Data System (ADS)

Anwar, M. A.; Kurniawan, T.; Asmara, Y. P.; Harun, W. S. W.; Oumar, A. N.; Nandyanto, A. B. D.

2017-10-01

In this work, the morphology of ZrO2 thin film from dip coating process on mild steel has been investigated. Mild steel was dip-coated on solution made of zirconium butoxide as a precursor, ethanol as solvent, acetylacetone as chelating agent and water for hydrolysis. Number of dipping was adjusted at 3, 5 and 7 times. The dipped sample then annealed at 350°C for two hours by adjusting the heating rate at 1°C/min respectively. The optical microscope showed that micro-cracks were observed on the surface of the coating with its concentration reduced as dipping sequence increased. The XRD result showed that annealing process can produce polycrystalline tetragonal-ZrO2. Meanwhile, SEM image showed that the thicknesses of the ZrO2 coatings were in between 400-600 nm. The corrosion resistance of uncoated and coated substrates was studied by polarization test through potentio-dynamic polarization curve at 1mV/s immersed in with 3.5% NaCl. The coating efficiency was improved as the number of layer dip coated increased, which showed improvement in corrosion protection.

In Situ Raman Microscopy of a Single Graphite Microflake Electrode in a Li(+)-containing Electrolyte

NASA Technical Reports Server (NTRS)

Shi, Qing-Fang; Dokko, Kaoru; Scherson, Daniel A.

2003-01-01

Highly detailed Raman spectra from a single KS-44 graphite microflake electrode as a function of the applied potential have been collected in situ using a Raman microscope and a sealed spectroelectrochemical cell isolated from the laboratory environment. Correlations were found between the Raman spectral features and the various Li(+) intercalation stages while recording in real time Raman spectra during a linear potential scan from 0.7 down ca. 0.0V vs Li/Li(+) at a rate of 0.1 mV/s in a 1M LiClO4 solution in a 1:l (by volume) ethylene carbonate (EC):diethyl carbonate (DEC) mixture. In particular, clearly defined isosbestic points were observed for data collected in the potential range where the transition between dilute phase 1 and phase 4 of lithiated graphite is known to occur, i.e. 0.157 < E < 0.215 vs Li/Li(+). Statistical analysis of the spectroscopic data within this region made it possible to determine independently the fraction of each of the two phases present as a function of potential without relying on coulometric information and then predict, based on the proposed stoichiometry for the transition, a spectrally-derived voltammetric feature.

A novel nitrite biosensor based on gold dendrites with egg white as template.

PubMed

He, Yaping; Zhang, Dawei; Dong, Sheying; Zheng, Jianbin

2012-01-01

Gold dendrites (AuD) were synthesized with egg white as the soft template and a novel nitrite (NO(2)(-)) biosensor was fabricated by assembly of a myoglobin (Mb)-L-cysteamine (Cys)-AuD biological hybrid. The results of Fourier transform infrared spectra and UV-visible spectra indicated that Mb retained its original structure in the resulting Mb-Cys-AuD. Electrochemical investigation of the biosensor showed a pair of well-defined, quasi-reversible redox peaks with E(pa) = -0.314 V and E(pc) = -0.344 V (vs. SCE) in 0.1 M, pH 7.0 sodium phosphate buffered saline at the scan rate of 200 mV/s. The transfer rate constant (k(s)) was 1.49 s(-1). The Mb-Cys-AuD showed a good electrochemical catalytic response for the reduction of NO(2)(-), with the linear range from 0.5 to 400 µM and the detection limit of 0.3 µM (S/N = 3). The apparent Michaelis-Menten constant (K(M)(app)) was estimated to be 0.2 mM. Therefore, the assembled bio-hybrid as a novel matrix opened up a further possibility for study on the design of enzymatic biosensors with potential applications.

Quantifying the morphodynamics of river restoration schemes using Unmanned Aerial Vehicles (UAVs)

NASA Astrophysics Data System (ADS)

Williams, Richard; Byrne, Patrick; Gilles, Eric; Hart, John; Hoey, Trevor; Maniatis, George; Moir, Hamish; Reid, Helen; Ves, Nikolas

2017-04-01

River restoration schemes are particularly sensitive to morphological adjustment during the first set of high-flow events that they are subjected to. Quantifying elevation change associated with morphological adjustment can contribute to improved adaptive decision making to ensure river restoration scheme objectives are achieved. To date the relatively high cost, technical demands and challenging logistics associated with acquiring repeat, high-resolution topographic surveys has resulted in a significant barrier to monitoring the three-dimensional morphodynamics of river restoration schemes. The availability of low-cost, consumer grade Unmanned Aerial Vehicles that are capable of acquiring imagery for processing using Structure-from-Motion Multi-View Stereo (SfM MVS) photogrammetry has the potential to transform the survey the morphodynamics of river restoration schemes. Application guidance does, however, need to be developed to fully exploit the advances of UAV technology and SfM MVS processing techniques. In particular, there is a need to quantify the effect of the number and spatial distribution of ground targets on vertical error. This is particularly significant because vertical errors propagate when mapping morphological change, and thus determine the evidence that is available for decision making. This presentation presents results from a study that investigated how the number and spatial distribution of targets influenced vertical error, and then used the findings to determine survey protocols for a monitoring campaign that has quantified morphological change across a number of restoration schemes. At the Swindale river restoration scheme, Cumbria, England, 31 targets were distributed across a 700 m long reach and the centre of each target was surveyed using RTK-GPS. Using the targets as General Control Points (GCPs) or checkpoints, they were divided into three different spatial patterns (centre, edge and random) and used for processing images acquired from a SenseFly Swinglet CAM UAV with a Canon IXUS 240 HS camera. Results indicate that if targets were distributed centrally then vertical distortions would be most notable in outer region of the processing domain; if an edge pattern was used then vertical errors were greatest in the central region of the processing domain; if targets were distributed randomly then errors were more evenly distributed. For this optimal random layout, vertical errors were lowest when 15 to 23 targets were used as GCPs. The best solution achieved planimetric (XY) errors of 0.006 m and vertical (Z) errors of 0.05 m. This result was used to determine target density and distribution for repeat surveys on two other restoration schemes, Whit Beck (Cumbria, England) and Allt Lorgy (Highlands, Scotland). These repeat surveys have been processed to produce DEMs of Difference (DoDs). The DoDs have been used to quantify the spatial distribution of erosion and deposition of these schemes due to high-flow events. Broader interpretation enables insight into patterns of morphological sensitivity that are related to scheme design.

Measles Virus Defective Interfering RNAs Are Generated Frequently and Early in the Absence of C Protein and Can Be Destabilized by Adenosine Deaminase Acting on RNA-1-Like Hypermutations.

PubMed

Pfaller, Christian K; Mastorakos, George M; Matchett, William E; Ma, Xiao; Samuel, Charles E; Cattaneo, Roberto

2015-08-01

Defective interfering RNAs (DI-RNAs) of the viral genome can form during infections of negative-strand RNA viruses and outgrow full-length viral genomes, thereby modulating the severity and duration of infection. Here we document the frequent de novo generation of copy-back DI-RNAs from independent rescue events both for a vaccine measles virus (vac2) and for a wild-type measles virus (IC323) as early as passage 1 after virus rescue. Moreover, vaccine and wild-type C-protein-deficient (C-protein-knockout [CKO]) measles viruses generated about 10 times more DI-RNAs than parental virus, suggesting that C enhances the processivity of the viral polymerase. We obtained the nucleotide sequences of 65 individual DI-RNAs, identified breakpoints and reinitiation sites, and predicted their structural features. Several DI-RNAs possessed clusters of A-to-G or U-to-C transitions. Sequences flanking these mutation sites were characteristic of those favored by adenosine deaminase acting on RNA-1 (ADAR1), which catalyzes in double-stranded RNA the C-6 deamination of adenosine to produce inosine, which is recognized as guanosine, a process known as A-to-I RNA editing. In individual DI-RNAs the transitions were of the same type and occurred on both sides of the breakpoint. These patterns of mutations suggest that ADAR1 edits unencapsidated DI-RNAs that form double-strand RNA structures. Encapsidated DI-RNAs were incorporated into virus particles, which reduced the infectivity of virus stocks. The CKO phenotype was dominant: DI-RNAs derived from vac2 with a CKO suppressed the replication of vac2, as shown by coinfections of interferon-incompetent lymphatic cells with viruses expressing different fluorescent reporter proteins. In contrast, coinfection with a C-protein-expressing virus did not counteract the suppressive phenotype of DI-RNAs. Recombinant measles viruses (MVs) are in clinical trials as cancer therapeutics and as vectored vaccines for HIV-AIDS and other infectious diseases. The efficacy of MV-based vectors depends on their replication proficiency and immune activation capacity. Here we document that copy-back defective interfering RNAs (DI-RNAs) are generated by recombinant vaccine and wild-type MVs immediately after rescue. The MV C protein interferes with DI-RNA generation and may enhance the processivity of the viral polymerase. We frequently detected clusters of A-to-G or U-to-C transitions and noted that sequences flanking individual mutations contain motifs favoring recognition by the adenosine deaminase acting on RNA-1 (ADAR1). The consistent type of transitions on the DI-RNAs indicates that these are direct substrates for editing by ADAR1. The ADAR1-mediated biased hypermutation events are consistent with the protein kinase R (PKR)-ADAR1 balancing model of innate immunity activation. We show by coinfection that the C-defective phenotype is dominant. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

A Highly Immunogenic and Protective Middle East Respiratory Syndrome Coronavirus Vaccine Based on a Recombinant Measles Virus Vaccine Platform

PubMed Central

Malczyk, Anna H.; Kupke, Alexandra; Prüfer, Steffen; Scheuplein, Vivian A.; Hutzler, Stefan; Kreuz, Dorothea; Beissert, Tim; Bauer, Stefanie; Hubich-Rau, Stefanie; Tondera, Christiane; Eldin, Hosam Shams; Schmidt, Jörg; Vergara-Alert, Júlia; Süzer, Yasemin; Seifried, Janna; Hanschmann, Kay-Martin; Kalinke, Ulrich; Herold, Susanne; Sahin, Ugur; Cichutek, Klaus; Waibler, Zoe; Eickmann, Markus; Becker, Stephan

2015-01-01

ABSTRACT In 2012, the first cases of infection with the Middle East respiratory syndrome coronavirus (MERS-CoV) were identified. Since then, more than 1,000 cases of MERS-CoV infection have been confirmed; infection is typically associated with considerable morbidity and, in approximately 30% of cases, mortality. Currently, there is no protective vaccine available. Replication-competent recombinant measles virus (MV) expressing foreign antigens constitutes a promising tool to induce protective immunity against corresponding pathogens. Therefore, we generated MVs expressing the spike glycoprotein of MERS-CoV in its full-length (MERS-S) or a truncated, soluble variant of MERS-S (MERS-solS). The genes encoding MERS-S and MERS-solS were cloned into the vaccine strain MVvac2 genome, and the respective viruses were rescued (MVvac2-CoV-S and MVvac2-CoV-solS). These recombinant MVs were amplified and characterized at passages 3 and 10. The replication of MVvac2-CoV-S in Vero cells turned out to be comparable to that of the control virus MVvac2-GFP (encoding green fluorescent protein), while titers of MVvac2-CoV-solS were impaired approximately 3-fold. The genomic stability and expression of the inserted antigens were confirmed via sequencing of viral cDNA and immunoblot analysis. In vivo, immunization of type I interferon receptor-deficient (IFNAR−/−)-CD46Ge mice with 2 × 105 50% tissue culture infective doses of MVvac2-CoV-S(H) or MVvac2-CoV-solS(H) in a prime-boost regimen induced robust levels of both MV- and MERS-CoV-neutralizing antibodies. Additionally, induction of specific T cells was demonstrated by T cell proliferation, antigen-specific T cell cytotoxicity, and gamma interferon secretion after stimulation of splenocytes with MERS-CoV-S presented by murine dendritic cells. MERS-CoV challenge experiments indicated the protective capacity of these immune responses in vaccinated mice. IMPORTANCE Although MERS-CoV has not yet acquired extensive distribution, being mainly confined to the Arabic and Korean peninsulas, it could adapt to spread more readily among humans and thereby become pandemic. Therefore, the development of a vaccine is mandatory. The integration of antigen-coding genes into recombinant MV resulting in coexpression of MV and foreign antigens can efficiently be achieved. Thus, in combination with the excellent safety profile of the MV vaccine, recombinant MV seems to constitute an ideal vaccine platform. The present study shows that a recombinant MV expressing MERS-S is genetically stable and induces strong humoral and cellular immunity against MERS-CoV in vaccinated mice. Subsequent challenge experiments indicated protection of vaccinated animals, illustrating the potential of MV as a vaccine platform with the potential to target emerging infections, such as MERS-CoV. PMID:26355094

Measles Virus Defective Interfering RNAs Are Generated Frequently and Early in the Absence of C Protein and Can Be Destabilized by Adenosine Deaminase Acting on RNA-1-Like Hypermutations

PubMed Central

Pfaller, Christian K.; Mastorakos, George M.; Matchett, William E.; Ma, Xiao; Samuel, Charles E.

2015-01-01

ABSTRACT Defective interfering RNAs (DI-RNAs) of the viral genome can form during infections of negative-strand RNA viruses and outgrow full-length viral genomes, thereby modulating the severity and duration of infection. Here we document the frequent de novo generation of copy-back DI-RNAs from independent rescue events both for a vaccine measles virus (vac2) and for a wild-type measles virus (IC323) as early as passage 1 after virus rescue. Moreover, vaccine and wild-type C-protein-deficient (C-protein-knockout [CKO]) measles viruses generated about 10 times more DI-RNAs than parental virus, suggesting that C enhances the processivity of the viral polymerase. We obtained the nucleotide sequences of 65 individual DI-RNAs, identified breakpoints and reinitiation sites, and predicted their structural features. Several DI-RNAs possessed clusters of A-to-G or U-to-C transitions. Sequences flanking these mutation sites were characteristic of those favored by adenosine deaminase acting on RNA-1 (ADAR1), which catalyzes in double-stranded RNA the C-6 deamination of adenosine to produce inosine, which is recognized as guanosine, a process known as A-to-I RNA editing. In individual DI-RNAs the transitions were of the same type and occurred on both sides of the breakpoint. These patterns of mutations suggest that ADAR1 edits unencapsidated DI-RNAs that form double-strand RNA structures. Encapsidated DI-RNAs were incorporated into virus particles, which reduced the infectivity of virus stocks. The CKO phenotype was dominant: DI-RNAs derived from vac2 with a CKO suppressed the replication of vac2, as shown by coinfections of interferon-incompetent lymphatic cells with viruses expressing different fluorescent reporter proteins. In contrast, coinfection with a C-protein-expressing virus did not counteract the suppressive phenotype of DI-RNAs. IMPORTANCE Recombinant measles viruses (MVs) are in clinical trials as cancer therapeutics and as vectored vaccines for HIV-AIDS and other infectious diseases. The efficacy of MV-based vectors depends on their replication proficiency and immune activation capacity. Here we document that copy-back defective interfering RNAs (DI-RNAs) are generated by recombinant vaccine and wild-type MVs immediately after rescue. The MV C protein interferes with DI-RNA generation and may enhance the processivity of the viral polymerase. We frequently detected clusters of A-to-G or U-to-C transitions and noted that sequences flanking individual mutations contain motifs favoring recognition by the adenosine deaminase acting on RNA-1 (ADAR1). The consistent type of transitions on the DI-RNAs indicates that these are direct substrates for editing by ADAR1. The ADAR1-mediated biased hypermutation events are consistent with the protein kinase R (PKR)-ADAR1 balancing model of innate immunity activation. We show by coinfection that the C-defective phenotype is dominant. PMID:25972541

System to provide 3D information on geological anomaly zone in deep subsea

NASA Astrophysics Data System (ADS)

Kim, W.; Kwon, O.; Kim, D.

2017-12-01

The study on building the ultra long and deep subsea tunnel of which length is 50km and depth is 200m at least, respectively, is underway in Korea. To analyze the geotechnical information required for designing and building subsea tunnel, topographic/geologiccal information analysis using 2D seabed geophysical prospecting and topographic, geologic, exploration and boring data were analyzed comprehensively and as a result, automation method to identify the geological structure zone under seabed which is needed to design the deep and long seabed tunnel was developed using geostatistical analysis. In addition, software using 3D visualized ground information to provide the information includes Gocad, MVS, Vulcan and DIMINE. This study is intended to analyze the geological anomaly zone for ultra deep seabed l and visualize the geological investigation result so as to develop the exclusive system for processing the ground investigation information which is convenient for the users. Particularly it's compatible depending on file of geophysical prospecting result and is realizable in Layer form and for 3D view as well. The data to be processed by 3D seabed information system includes (1) deep seabed topographic information, (2) geological anomaly zone, (3) geophysical prospecting, (4) boring investigation result and (5) 3D visualization of the section on seabed tunnel route. Each data has own characteristics depending on data and interface to allow interlocking with other data is granted. In each detail function, input data is displayed in a single space and each element is selectable to identify the further information as a project. Program creates the project when initially implemented and all output from detail information is stored by project unit. Each element representing detail information is stored in image file and is supported to store in text file as well. It also has the function to transfer, expand/reduce and rotate the model. To represent the all elements in 3D visualized platform, coordinate and time information are added to the data or data group to establish the conceptual model as a whole. This research was supported by the Korea Agency for Infrastructure Technology Advancement under the Ministry of Land, Infrastructure and Transport of the Korean government(Project Number: 13 Construction Research T01).

Preparation and electrochemical characterization of polyaniline/activated carbon composites as an electrode material for supercapacitors.

PubMed

Oh, Misoon; Kim, Seok

2012-01-01

Polyaniline (PANI)/activated carbon (AC) composites were prepared by a chemical oxidation polymerization. To find an optimum ratio between PANI and AC which shows superior electrochemical properties, the preparation was carried out in changing the amount of added aniline monomers. The morphology of prepared composites was investigated by scanning electron microscopy (SEM) and transmission electron microscope (TEM). The structural and thermal properties were investigated by Fourier transform infrared spectra (FT-IR) and thermal gravimetric analysis (TGA), respectively. The electrochemical properties were characterized by cyclic voltammetry (CV). Composites showed a summation of capacitances that consisted of two origins. One is double-layer capacitance by ACs and the other is faradic capacitance by redox reaction of PANI. Fiber-like PANIs are coated on the surface of ACs and they contribute to the large surface for redox reaction. The vacancy among fibers provided the better diffusion and accessibility of ion. High capacitances of composites were originated from the network structure having vacancy made by PANI fibers. It was found that the composite prepared with 5 ml of aniline monomer and 0.25 g of AC showed the highest capacitance. Capacitance of 771 F/g was obtained at a scan rate of 5 mV/s.

Fluorination effect of activated carbons on performance of asymmetric capacitive deionization

NASA Astrophysics Data System (ADS)

Jo, Hanjoo; Kim, Kyung Hoon; Jung, Min-Jung; Park, Jae Hyun; Lee, Young-Seak

2017-07-01

Activated carbons (ACs) were fluorinated and fabricated into electrodes to investigate the effect of fluorination on asymmetric capacitive deionization (CDI). Fluorine functional groups were introduced on the AC surfaces via fluorination. The specific capacitance of the fluorinated AC (Fsbnd AC) electrode increased drastically from 261 to 337 F/g compared with the untreated AC (Rsbnd AC) electrode at a scan rate of 5 mV/s, despite a decrease in the specific surface area and total pore volume after fluorination. The desalination behavior of asymmetric CDI cells assembled with an Rsbnd AC electrode as the counter electrode and an Fsbnd AC electrode as the cathode (R || F-) or anode (R || F +) was studied. For R || F-, the salt adsorption capacity and charge efficiency increased from 10.6 mg/g and 0.58-12.4 mg/g and 0.75, respectively, compared with the CDI cell assembled with identical Rsbnd AC electrodes at 1 V. This CDI cell exhibited consistently better salt adsorption capacity and charge efficiency at different applied voltages because Fsbnd AC electrodes have a cation attractive effect originating from the partially negatively charged fluorine functional groups on the AC surface. Therefore, co-ion expulsion in the Fsbnd AC electrode as the cathode is effectively diminished, leading to enhanced CDI performance.

Good mates retain us right: investigating the relationship between mate retention strategies, mate value, and relationship satisfaction.

PubMed

Salkicevic, Svjetlana; Stanic, Ajana L; Grabovac, Masa T

2014-12-07

Mate retention strategies are an important tool in keeping a partner, and their use is determined by the mate value (MV) of the partner one is trying to keep. The type of strategy used is also dependent on one's own MV: mates of lower MV are more prone to exhibiting strategies that are cost-inflicting for their partners, whereas partner-benefiting strategies are used by mates of higher value. The type of strategies used affects relationship satisfaction (RS), and is also affected by the perceived difference in MVs. However, it is unclear how someone's perception of their partner's MV is related to that partner's behavior and their own RS. To this aim, we investigated the relationship between these variables on a sample of 178 couples. Our results showed that benefit-inducing strategies were used more by--and towards--partners of higher MV, and were positively connected with RS. Cost-inflicting strategies were more used by--and towards--partners of lower MV, and were negatively connected with RS. Less MV difference was positively correlated with RS and benefiting strategies, and negatively correlated with cost-inflicting strategies. It seems that good mates use strategies that benefit their partners, which, in turn, make them more valuable and, consequently, their partner more satisfied.

NiCoO2 flowers grown on the aligned-flakes coated Ni foam for application in hybrid energy storage

NASA Astrophysics Data System (ADS)

Xu, Xiaoyang; Zhao, Huilin; Zhou, JingKuo; Xue, Ruinan; Gao, Jianping

2016-10-01

Many NiCoO2 flowers with an average diameter of about 4 μm were grown on the NiCoO2 flakes coated Ni foam (denoted as NiCoO2/Ni foam) through a simple hydrothermal method and confirmed by scanning and transmission electron microscopies, X-ray diffraction and X-ray photoelectron spectrum measurements. The NiCoO2/Ni foam with high specific area and porosity was directly used as the working electrode without any binders. The measured specific capacitance of NiCoO2 grown on Ni foam is 756 F/g at 0.75 A/g using a three-electrode setup in 1 M KOH. Considering the high capacity of NiCoO2 and the good stability of rGO, the NiCoO2/Ni foam//rGO hybrid supercapacitor combining NiCoO2/Ni foam and rGO shows very good properties, such as high specific capacitance (82 F/g at 2 A/g based on the total mass of active materials), high energy density (25.7 Wh/kg at 1500 W/kg based on the total mass of active materials), good stability (about 90% capacitance retention after 2000-cycle at 100 mV/s), and low charge ion transfer resistance.

Effect of the nanosized TiO2 particles in Pd/C catalysts as cathode materials in direct methanol fuel cells.

PubMed

Choi, Mahnsoo; Han, Choonsoo; Kim, In-Tae; Lee, Ji-Jung; Lee, Hong-Ki; Shim, Joongpyo

2011-07-01

Pd-TiO2/C catalysts were prepared by impregnating titanium dioxide (TiO2) on carbon-supported Pd (Pd/C) for use as the catalyst for the oxygen reduction reaction (ORR) in direct methanol fuel cells (DMFCs). Transmission electron microscope (TEM), scanning electron microscope (SEM) and X-ray diffraction (XRD) analyses were carried to confirm the distribution, morphology and structure of Pd and TiO2 on the carbon support. In fuel cell test, we confirmed that the addition of TiO2 nanoparticles make the improved catalytic activity of oxygen reduction. The electrochemical characterization of the Pd-TiO2/C catalyst for the ORR was carried out by cyclic voltammetry (CV) in the voltage window of 0.04 V to 1.2 V with scan rate of 25 mV/s. With the increase in the crystallite size of TiO2, the peak potential for OH(ads) desorption on the surface of Pd particle shifted to higher potential. This implies that TiO2 might affect the adsorption and desorption of oxygen molecules on Pd catalyst. The performance of Pd-TiO2/C as a cathode material was found to be similar to or better performance than that of Pt/C.

Nitrated carbon nanoblisters for high-performance glucose dehydrogenase bioanodes.

PubMed

de Souza, João C P; Iost, Rodrigo M; Crespilho, Frank N

2016-03-15

Recently, many strategies are being explored for efficiently wiring glucose dehydrogenase (GDh) enzymes capable of glucose (fuel) oxidation. For instance, the use of GDh NAD(+)-dependent for glucose oxidation is of great interest in biofuel cell technology because the enzyme are unaffected by the presence of molecular oxygen commonly present in electrolyte. Here we present the fabrication of flexible carbon fibers modified with nitrated carbon nanoblisters and their application as high-performance GDh bioanodes. These bioelectrodes could electro-oxidize glucose at -360 mV (vs. Ag/AgClsat) in the presence of a molecular oxygen saturated electrolyte with current densities higher than 1.0 mAcm(-2) at 0.0 V. It is corroborated by open circuit potential, where a potential stabilization occurs at -150 mV in a long term stability current-transient experiment. This value is in agreement with the quasi-steady current obtained at very low scan rate (0.1 mVs(-1)), where the onset potential for glucose oxidation is -180 mV. X-ray photoelectron spectroscopy and scanning electron microscopy revealed that the nitrated blisters and edge-like carbon structures, enabling highly efficient enzyme immobilization and low overpotential for electron transfer, allowing for glucose oxidation with potential values close to the thermodynamic cofactor. Copyright © 2015 Elsevier B.V. All rights reserved.

Core-Shell Composite Fibers for High-Performance Flexible Supercapacitor Electrodes.

PubMed

Lu, Xiaoyan; Shen, Chen; Zhang, Zeyang; Barrios, Elizabeth; Zhai, Lei

2018-01-31

Core-shell nanofibers containing poly(acrylic acid) (PAA) and manganese oxide nanoparticles as the core and polypyrrole (PPy) as the shell were fabricated through electrospinning the solution of PAA and manganese ions (PAA/Mn 2+ ). The obtained nanofibers were stabilized by Fe 3+ through the interaction between Fe 3+ ions and carboxylate groups. Subsequent oxidation of Mn 2+ by KMnO 4 produced uniform manganese dioxide (MnO 2 ) nanoparticles in the fibers. A PPy shell was created on the fibers by immersing the fibers in a pyrrole solution where the Fe 3+ ions in the fiber polymerized the pyrrole on the fiber surfaces. In the MnO 2 @PAA/PPy core-shell composite fibers, MnO 2 nanoparticles function as high-capacity materials, while the PPy shell prevents the loss of MnO 2 during the charge/discharge process. Such a unique structure makes the composite fibers efficient electrode materials for supercapacitors. The gravimetric specific capacity of the MnO 2 @PAA/PPy core-shell composite fibers was 564 F/g based on cyclic voltammetry curves at 10 mV/s and 580 F/g based on galvanostatic charge/discharge studies at 5 A/g. The MnO 2 @PAA/PPy core-shell composite fibers also present stable cycling performance with 100% capacitance retention after 5000 cycles.

SAP- FORTRAN STATIC SOURCE CODE ANALYZER PROGRAM (IBM VERSION)

NASA Technical Reports Server (NTRS)

Manteufel, R.

1994-01-01

The FORTRAN Static Source Code Analyzer program, SAP, was developed to automatically gather statistics on the occurrences of statements and structures within a FORTRAN program and to provide for the reporting of those statistics. Provisions have been made for weighting each statistic and to provide an overall figure of complexity. Statistics, as well as figures of complexity, are gathered on a module by module basis. Overall summed statistics are also accumulated for the complete input source file. SAP accepts as input syntactically correct FORTRAN source code written in the FORTRAN 77 standard language. In addition, code written using features in the following languages is also accepted: VAX-11 FORTRAN, IBM S/360 FORTRAN IV Level H Extended; and Structured FORTRAN. The SAP program utilizes two external files in its analysis procedure. A keyword file allows flexibility in classifying statements and in marking a statement as either executable or non-executable. A statistical weight file allows the user to assign weights to all output statistics, thus allowing the user flexibility in defining the figure of complexity. The SAP program is written in FORTRAN IV for batch execution and has been implemented on a DEC VAX series computer under VMS and on an IBM 370 series computer under MVS. The SAP program was developed in 1978 and last updated in 1985.

SAP- FORTRAN STATIC SOURCE CODE ANALYZER PROGRAM (DEC VAX VERSION)

NASA Technical Reports Server (NTRS)

Merwarth, P. D.

1994-01-01

The FORTRAN Static Source Code Analyzer program, SAP, was developed to automatically gather statistics on the occurrences of statements and structures within a FORTRAN program and to provide for the reporting of those statistics. Provisions have been made for weighting each statistic and to provide an overall figure of complexity. Statistics, as well as figures of complexity, are gathered on a module by module basis. Overall summed statistics are also accumulated for the complete input source file. SAP accepts as input syntactically correct FORTRAN source code written in the FORTRAN 77 standard language. In addition, code written using features in the following languages is also accepted: VAX-11 FORTRAN, IBM S/360 FORTRAN IV Level H Extended; and Structured FORTRAN. The SAP program utilizes two external files in its analysis procedure. A keyword file allows flexibility in classifying statements and in marking a statement as either executable or non-executable. A statistical weight file allows the user to assign weights to all output statistics, thus allowing the user flexibility in defining the figure of complexity. The SAP program is written in FORTRAN IV for batch execution and has been implemented on a DEC VAX series computer under VMS and on an IBM 370 series computer under MVS. The SAP program was developed in 1978 and last updated in 1985.

Construction of novel electrochemical immunosensor for detection of prostate specific antigen using ferrocene-PAMAM dendrimers.

PubMed

Çevik, Emre; Bahar, Özlem; Şenel, Mehmet; Abasıyanık, M Fatih

2016-12-15

In this study, an immunosensor was designed to utilize for the detection of prostate specific antigen (PSA) based on three different generations (G1, G2 and G3) of ferrocene (Fc) cored polyamidiamine dendrimers (Fc-PAMAM) gold (Au) electrode. The self-assembled monolayer principle (SAM) was used to fabricate the sensitive, selective and disposable immunosensor electrodes. In electrode fabrication cysteamine (Cys) was the first agent covalently linked on the Au electrode surface. Immobilized redox center (ferrocene) cored PAMAM dendrimers served as a layer for the further binding of biological components. The monoclonal antibody of PSA (anti-PSA) was covalently immobilized on dendrimers which were attached onto the modified Au surface (Au/Cys/Fc-PAMAMs/anti-PSA). PSA levels were quantitatively analyzed by using electrochemical differential pulse voltammetry (DPV) whose lowest detection limit was calculated as 0.001ngmL(-1). The Au/Cys/FcPAMAM/anti-PSA immunosensor showed excellent performance for PSA at the pulse amplitude; 50mV and the scan rate; 10mV/s in a wide linear concentration range of 0.01ng-100ngmL(-1). Analytical performance and specificity assays were carried out using human serum and different proteins. Copyright © 2016 Elsevier B.V. All rights reserved.

Application of atmospheric-pressure plasma jet processed carbon nanotubes to liquid and quasi-solid-state gel electrolyte supercapacitors

NASA Astrophysics Data System (ADS)

Kuok, Fei-Hong; Kan, Ken-Yuan; Yu, Ing-Song; Chen, Chieh-Wen; Hsu, Cheng-Che; Cheng, I.-Chun; Chen, Jian-Zhang

2017-12-01

We use a dc-pulse nitrogen atmospheric-pressure plasma jet (APPJ) to calcine carbon nanotubes (CNTs) pastes that are screen-printed on carbon cloth. 30-s APPJ treatment can efficiently oxidize and vaporize the organic binders, thereby forming porous structures. As indicated by X-ray photoelectron spectroscopy (XPS) and electron probe microanalysis (EPMA), the oxygen content decreases after APPJ treatment owing to the oxidation and vaporization of ethyl cellulose, terpineol, and ethanol. Nitrogen doping was introduced to the materials by the nitrogen APPJ. APPJ-calcination improves the wettability of the CNTs printed on carbon cloth, as evidenced by water contact angle measurement. Raman spectroscopy indicates that reactive species of nitrogen APPJ react violently with CNTs in only 30-s APPJ processing time and introduce defects and/or surface functional groups on CNTs. Carbon cloths with calcined CNT layers are used as electrodes for liquid and quasi-solid-state electrolyte supercapacitors. Under a cyclic voltammetry test with a 2 mV/s potential scan rate, the specific capacitance is 73.84 F/g (areal capacitance = 5.89 mF/cm2) with a 2 M KCl electrolyte and 66.47 F/g (areal capacitance = 6.10 mF/cm2) with a H2SO4/polyvinyl alcohol (PVA) gel electrolyte.

Enhancing the performance of green solid-state electric double-layer capacitor incorporated with fumed silica nanoparticles

NASA Astrophysics Data System (ADS)

Chong, Mee Yoke; Numan, Arshid; Liew, Chiam-Wen; Ng, H. M.; Ramesh, K.; Ramesh, S.

2018-06-01

Solid polymer electrolyte (SPE) based on fumed silica nanoparticles as nanofillers, hydroxylethyl cellulose (HEC) as host polymer, magnesium trifluoromethanesulfonate salt and 1-ethyl-3-methylimidazolium trifluoromethanesulfonate ionic liquid is prepared by solution casting technique. The ionic conductivity, interactions of adsorbed ions on the host polymer, structural crystallinity and thermal stability are evaluated by electrochemical impedance spectroscopy (EIS), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and thermogravimetric analysis (TGA), respectively. Ionic conductivity studies at room temperature reveals that the SPE with 2 wt. % of fumed silica nanoparticles gives the highest conductivity compared to its counterpart. The XRD and FTIR studies confirm the dissolution of salt, ionic liquid and successful incorporation of fumed silica nanoparticles with host polymer. In order to examine the performance of SPEs, electric double-layer capacitor (EDLC) are fabricated by using activated carbon electrodes. EDLC studies demonstrate that SPE incorporated with 2 wt. % fumed silica nanoparticles gives high specific capacitance (25.0 F/g) at a scan rate of 5 mV/s compared to SPE without fumed silica. Additionally, it is able to withstand 71.3% of capacitance from its initial capacitance value over 1600 cycles at a current density of 0.4 A/g.

Porous MnO2 prepared by sol-gel method for electrochemical supercapacitor

NASA Astrophysics Data System (ADS)

Bazzi, K.; Kumar, A.; Jayakumar, O. D.; Nazri, G. A.; Naik, V. M.; Naik, R.

2015-03-01

MnO2 has attracted great attention as material for electrochemical pseudocapacitor due to its high theoretical specific faradic capacitance (~ 1370 F .g-1) , environmental friendliness and wide potential window in both aqueous and nonaqueous electrolytes. However, the MnO2 has a low surface area which depresses its electrochemical performance. The amorphous α-MnO2 composite was synthesized by sol gel method in the presence of the tri-block copolymer P123. Our aim is to investigate the role of P123 on the electrochemical performance of MnO2. The samples with and without P123 were prepared and characterized by x-ray diffraction (XRD), SEM, TEM and Brunauer-Emmett-Teller (BET) method. The electrochemical performances of the amorphous MnO2 composites as the electrode materials for supercapacitors were evaluated by cyclic voltammetry and AC impedance measurements in a 1M Na2SO4 solution. The results show that the sample prepared without P123 exhibited a relatively low specific capacitance of 28F .g-1, whereas the porous MnO2 prepared with P123 exhibited 117 F .g-1at 5 mV/s. The results of crystalline MnO2 composites will also be presented. The authors acknowledge the support from the Richard J. Barber Foundation for Interdisciplinary Research.

Parametric Optimization of Some Critical Operating System Functions--An Alternative Approach to the Study of Operating Systems Design

ERIC Educational Resources Information Center

Sobh, Tarek M.; Tibrewal, Abhilasha

2006-01-01

Operating systems theory primarily concentrates on the optimal use of computing resources. This paper presents an alternative approach to teaching and studying operating systems design and concepts by way of parametrically optimizing critical operating system functions. Detailed examples of two critical operating systems functions using the…

Simple fabrication of reduced graphene oxide -few layer MoS2 nanocomposite for enhanced electrochemical performance in supercapacitors and water purification

NASA Astrophysics Data System (ADS)

Raghu, M. S.; Yogesh Kumar, K.; Rao, Srilatha; Aravinda, T.; Sharma, S. C.; Prashanth, M. K.

2018-05-01

Expelling of heavy metal ions into water resource systems is extremely hazardous to the environment. Adsorption is one of the most cost effective and potential methods to remove the heavy metal ions from the effluents. Therefore, an attempt has been made to study the adsorption of metal particles of Cd and Hg from aqueous solution by using reduced graphene oxide-molybdenum disulphide (rGO-MoS2) nanocomposites as adsorbents. The rGO-MoS2 composites were synthesized by following simple physical methods; which involve the mixing of dispersions of MoS2 and graphene oxide (GO) by sonication, followed by subsequent reduction with hydrazine hydrate. Characterization of the nanocomposites was performed by FESEM, TEM, EDAX, raman spectroscopy, XRD and BET surface area analysis. Electron microscopic images validate the presence of homogeneity in the synthesized nanocomposite. Batch adsorption experiments were used to scrutinizethe effect of an array of parameters like effect of pH, initial concentration of the metal ions, adsorbent dose, and contact time on the adsorption capacity of metal ions on rGO-MoS2 nanocomposites. The thorough examination of adsorbed isotherm and energy demonstrates the best fitting of the adsorption data with the 'Langmuir adsorption isotherm model' and follows the pseudo-second-order kinetic in active condition. The synthesized materials havealso been tested against Gram-positive and Gram-negative bacterial strains and have showcased promising antimicrobial activities. At the same time, the nanocomposites were evaluated for electrochemical performance in supercapacitors. The rGO-MoS2 nanocomposite demonstrates better capacitance (440 Fg-1) at 5 mvs-1 scan rate. The inimitable surface property of MoS2 and good electrical conductivity of rGO results show versatile usage and formidable performance as an adsorbent, antibacterial agent and electrode material for supercapacitors.

3D printed mitral valve models: affordable simulation for robotic mitral valve repair.

PubMed

Premyodhin, Ned; Mandair, Divneet; Ferng, Alice S; Leach, Timothy S; Palsma, Ryan P; Albanna, Mohammad Z; Khalpey, Zain I

2018-01-01

3D printed mitral valve (MV) models that capture the suture response of real tissue may be utilized as surgical training tools. Leveraging clinical imaging modalities, 3D computerized modelling and 3D printing technology to produce affordable models complements currently available virtual simulators and paves the way for patient- and pathology-specific preoperative rehearsal. We used polyvinyl alcohol, a dissolvable thermoplastic, to 3D print moulds that were casted with liquid platinum-cure silicone yielding flexible, low-cost MV models capable of simulating valvular tissue. Silicone-moulded MV models were fabricated for 2 morphologies: the normal MV and the P2 flail. The moulded valves were plication and suture tested in a laparoscopic trainer box with a da Vinci Si robotic surgical system. One cardiothoracic surgery fellow and 1 attending surgeon qualitatively evaluated the ability of the valves to recapitulate tissue feel through surveys utilizing the 5-point Likert-type scale to grade impressions of the valves. Valves produced with the moulding and casting method maintained anatomical dimensions within 3% of directly 3D printed acrylonitrile butadiene styrene controls for both morphologies. Likert-type scale mean scores corresponded with a realistic material response to sutures (5.0/5), tensile strength that is similar to real MV tissue (5.0/5) and anatomical appearance resembling real MVs (5.0/5), indicating that evaluators 'agreed' that these aspects of the model were appropriate for training. Evaluators 'somewhat agreed' that the overall model durability was appropriate for training (4.0/5) due to the mounting design. Qualitative differences in repair quality were notable between fellow and attending surgeon. 3D computer-aided design, 3D printing and fabrication techniques can be applied to fabricate affordable, high-quality educational models for technical training that are capable of differentiating proficiency levels among users. © The Author 2017. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

Operational Characteristics of an Accelerator Driven Fissile Solution System

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

Kimpland, Robert Herbert

Operational characteristics represent the set of responses that a nuclear system exhibits during normal operation. Operators rely on this behavior to assess the status of the system and to predict the consequences of off-normal events. These characteristics largely refer to the relationship between power and system operating conditions. The static and dynamic behavior of a chain-reacting system, operating at sufficient power, is primarily governed by reactivity effects. The science of reactor physics has identified and evaluated a number of such effects, including Doppler broadening and shifts in the thermal neutron spectrum. Often these reactivity effects are quantified in the formmore » of feedback coefficients that serve as coupling coefficients relating the neutron population and the physical mechanisms that drive reactivity effects, such as fissile material temperature and density changes. The operational characteristics of such nuclear systems usually manifest themselves when perturbations between system power (neutron population) and system operating conditions arise. Successful operation of such systems requires the establishment of steady equilibrium conditions. However, prior to obtaining the desired equilibrium (steady-state) conditions, an approach from zero-power (startup) must occur. This operational regime may possess certain limiting system conditions that must be maintained to achieve effective startup. Once steady-state is achieved, a key characteristic of this operational regime is the level of stability that the system possesses. Finally, a third operational regime, shutdown, may also possess limiting conditions of operation that must be maintained. This report documents the operational characteristics of a “generic” Accelerator Driven Fissile Solution (ADFS) system during the various operational regimes of startup, steady-state operation, and shutdown. Typical time-dependent behavior for each operational regime will be illustrated, and key system parameters, such as response times, will be quantified. A generalized linear systems analysis of steady-state operations will be performed to evaluate the level of stability of ADFS systems. This information should provide a basic understanding of typical ADFS system operational behavior, and facilitate the development of monitoring procedures and operator aids.« less

Unresolved clinical aspects and safety hazards of blood derived- EV/MV in stored blood components: From personal memory lanes to newer perspectives on the roles of EV/MV in various biological phenomena.

PubMed

Seghatchian, Jerard; Amiral, Jean

2016-08-01

Blood cells generate heterogeneous populations of vesicles that are delivered, as small-specialized packages of highly active cell fragments in blood circulation, having almost similar functional activities, as the mother cells. These so called extracellular vesicles are the essential part of an energy-dependent natural apoptotic process; hence their beneficial and harmful biological functions cannot be ignored. Evidence is accumulating, that cellular derived vesicles, originate from all viable cells including: megakaryocytes, platelets, red blood cells, white blood cells and endothelial cells, the highest in proportions from platelets. Shedding can also be triggered by pathological activation of inflammatory processes and activation of coagulation or complement pathways, or even by shear stress in the circulation. Structurally, so called MV/EV appear to be, sometimes inside-out and sometimes outside-in cell fragments having a bilayered phospholipid structure exposing coagulant-active phosphatidylserine, expressing various membrane receptors, and they serve as cell-to-cell shuttles for bioactive molecules such as lipids, growth factors, microRNAs, and mitochondria. Ex vivo processing of blood into its components, embodying centrifugation, processing by various apheresis procedures, leukoreduction, pathogen reduction, and finally storage in different media and different types of blood bags, also have major impacts on the generation and retention of MV content. These artificially generated small, but highly liable packages, together with the original pool of MVs collected from the donor, do exhibit differing biological activities, and are not inert elements and should be considered as a parameter of blood safety in haemovigilance programmes. Harmonization and consensus in sampling protocols, sample handling, processing, and assessment methods, in particular converting to full automation, are needed to achieve consensual interpretations. This review focuses on some of our past personal studies on the role of MV/EV focusing on characterization of platelet storage lesion and platelet therapy that shows the highest transfusion hazards [up to 25%], and loss of 25% platelet efficacy after various leukoreduction and validated platelet pathogen reduction treatments. The planned paths for the future of EV/MV involvement in immunological and viral/ non-viral transfusion hazards are also discussed. Whilst considerable advances made on the characterization of EV/MV, but disparity still exists between various surrogate markers, showing some subtle differences in the levels of MV/ EV & BRMs in platelet preparations, and the clinical outcome showing platelets derived by all current technologies are equivalents in vivo. One possible reason for such a disparity may be relatedto the fact that MVs, being the end products of apoptotic cells, have little specificity and clear rapidly from circulation [<6 h in thrombocytopoenia]. This makes their clinical usefulness rather short lived. The recent findings that pegylating smaller subsets of EV increases its circulatory life from <15 minutes to approximately about one hour is highly promising, in particular, for drug delivery on specific sides. Hence a promising clinical utility of EV/MV continues, as a journey without end, indeed. This manuscript is based mainly on the selected key readings listed below. Copyright © 2016. Published by Elsevier Ltd.

Evaluation of Microcomputer-Based Operation and Maintenance Management Systems for Army Water/Wastewater Treatment Plant Operation.

DTIC Science & Technology

1986-07-01

COMPUTER-AIDED OPERATION MANAGEMENT SYSTEM ................. 29 Functions of an Off-Line Computer-Aided Operation Management System Applications of...System Comparisons 85 DISTRIBUTION 5V J. • 0. FIGURES Number Page 1 Hardware Components 21 2 Basic Functions of a Computer-Aided Operation Management System...Plant Visits 26 4 Computer-Aided Operation Management Systems Reviewed for Analysis of Basic Functions 29 5 Progress of Software System Installation and

Cognitive engineering models in space systems

NASA Technical Reports Server (NTRS)

Mitchell, Christine M.

1992-01-01

NASA space systems, including mission operations on the ground and in space, are complex, dynamic, predominantly automated systems in which the human operator is a supervisory controller. The human operator monitors and fine-tunes computer-based control systems and is responsible for ensuring safe and efficient system operation. In such systems, the potential consequences of human mistakes and errors may be very large, and low probability of such events is likely. Thus, models of cognitive functions in complex systems are needed to describe human performance and form the theoretical basis of operator workstation design, including displays, controls, and decision support aids. The operator function model represents normative operator behavior-expected operator activities given current system state. The extension of the theoretical structure of the operator function model and its application to NASA Johnson mission operations and space station applications is discussed.

Operationally Efficient Propulsion System Study (OEPSS) data book. Volume 3: Operations technology

NASA Technical Reports Server (NTRS)

Vilja, John O.

1990-01-01

The study was initiated to identify operational problems and cost drivers for current propulsion systems and to identify technology and design approaches to increase the operational efficiency and reduce operations costs for future propulsion systems. To provide readily usable data for the Advanced Launch System (ALS) program, the results of the OEPSS study were organized into a series of OEPSS Data Books. This volume describes operations technologies that will enhance operational efficiency of propulsion systems. A total of 15 operations technologies were identified that will eliminate or mitigate operations problems described in Volume 2. A recommended development plan is presented for eight promising technologies that will simplify the propulsion system and reduce operational requirements.

High-Performance Computing Systems and Operations | Computational Science |

Science.gov Websites

NREL Systems and Operations High-Performance Computing Systems and Operations NREL operates high-performance computing (HPC) systems dedicated to advancing energy efficiency and renewable energy technologies. Capabilities NREL's HPC capabilities include: High-Performance Computing Systems We operate

Systems Operations Studies for Automated Guideway Transit Systems : Quantitative Analysis of Alternative AGT Operational Control Strategies

DOT National Transportation Integrated Search

1981-10-01

The objectives of the Systems Operation Studies (SOS) for automated guideway transit (AGT) systems are to develop models for the analysis of system operations, to evaluate performance and cost, and to establish guidelines for the design and operation...

49 CFR 234.205 - Operating characteristics of warning system apparatus.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 4 2014-10-01 2014-10-01 false Operating characteristics of warning system... Maintenance Standards § 234.205 Operating characteristics of warning system apparatus. Operating... system shall be maintained in accordance with the limits within which the system is designed to operate. ...

49 CFR 234.205 - Operating characteristics of warning system apparatus.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 4 2012-10-01 2012-10-01 false Operating characteristics of warning system... Maintenance Standards § 234.205 Operating characteristics of warning system apparatus. Operating... system shall be maintained in accordance with the limits within which the system is designed to operate. ...

49 CFR 234.205 - Operating characteristics of warning system apparatus.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 4 2013-10-01 2013-10-01 false Operating characteristics of warning system... Maintenance Standards § 234.205 Operating characteristics of warning system apparatus. Operating... system shall be maintained in accordance with the limits within which the system is designed to operate. ...

A Consideration of Stable Operating Power Limits of HVDC System Composed of Voltage Source Converters

NASA Astrophysics Data System (ADS)

Konishi, Hiroo; Takahashi, Choei; Kishibe, Hideto; Sato, Hiromichi

The stable operating power limits of a small scale HVDC system composed of voltage source converters (VSC-HVDC system) are analyzed with a simple model. The VSC-HVDC system could operate where the AC system must be somewhat larger in capacity than the VSC-HVDC system capacity. The stable operating power limits were between one and two times the SCR (short circuit ratio). When the inverter of the VSC-HVDC system was operated with lead reactive (capacitive) power control conditions, the stable operating limits were increased through AC voltage stabilization. When the inverter was a STATCOM operation, it could operate regardless of the SCR but regions within allowable AC voltage variations.

Implementation of NASTRAN on the IBM/370 CMS operating system

NASA Technical Reports Server (NTRS)

Britten, S. S.; Schumacker, B.

1980-01-01

The NASA Structural Analysis (NASTRAN) computer program is operational on the IBM 360/370 series computers. While execution of NASTRAN has been described and implemented under the virtual storage operating systems of the IBM 370 models, the IBM 370/168 computer can also operate in a time-sharing mode under the virtual machine operating system using the Conversational Monitor System (CMS) subset. The changes required to make NASTRAN operational under the CMS operating system are described.

Operator Support System Design forthe Operation of RSG-GAS Research Reactor

NASA Astrophysics Data System (ADS)

Santoso, S.; Situmorang, J.; Bakhri, S.; Subekti, M.; Sunaryo, G. R.

2018-02-01

The components of RSG-GAS main control room are facing the problem of material ageing and technology obsolescence as well, and therefore the need for modernization and refurbishment are essential. The modernization in control room can be applied on the operator support system which bears the function in providing information for assisting the operator in conducting diagnosis and actions. The research purpose is to design an operator support system for RSG-GAS control room. The design was developed based on the operator requirement in conducting task operation scenarios and the reactor operation characteristics. These scenarios include power operation, low power operation and shutdown/scram reactor. The operator support system design is presented in a single computer display which contains structure and support system elements e.g. operation procedure, status of safety related components and operational requirements, operation limit condition of parameters, alarm information, and prognosis function. The prototype was developed using LabView software and consisted of components structure and features of the operator support system. Information of each component in the operator support system need to be completed before it can be applied and integrated in the RSG-GAS main control room.

Formal Integrals and Noether Operators of Nonlinear Hyperbolic Partial Differential Systems Admitting a Rich Set of Symmetries

NASA Astrophysics Data System (ADS)

Startsev, Sergey Ya.

2017-05-01

The paper is devoted to hyperbolic (generally speaking, non-Lagrangian and nonlinear) partial differential systems possessing a full set of differential operators that map any function of one independent variable into a symmetry of the corresponding system. We demonstrate that a system has the above property if and only if this system admits a full set of formal integrals (i.e., differential operators which map symmetries into integrals of the system). As a consequence, such systems possess both direct and inverse Noether operators (in the terminology of a work by B. Fuchssteiner and A.S. Fokas who have used these terms for operators that map cosymmetries into symmetries and perform transformations in the opposite direction). Systems admitting Noether operators are not exhausted by Euler-Lagrange systems and the systems with formal integrals. In particular, a hyperbolic system admits an inverse Noether operator if a differential substitution maps this system into a system possessing an inverse Noether operator.

49 CFR 37.33 - Airport transportation systems.

Code of Federal Regulations, 2010 CFR

2010-10-01

... systems operated by public airport operators, which provide designated public transportation and connect.... Public airports which operate fixed route transportation systems are subject to the requirements of this... part. (b) Fixed-route transportation systems operated by public airport operators between the airport...

9 CFR 205.201 - System operator.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 9 Animals and Animal Products 2 2014-01-01 2014-01-01 false System operator. 205.201 Section 205... Interpretive Opinions § 205.201 System operator. The system operator can be the Secretary of State of a State... system refers to operation by the Secretary of State of a State, but the definition in (c)(11) of...

9 CFR 205.201 - System operator.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 9 Animals and Animal Products 2 2011-01-01 2011-01-01 false System operator. 205.201 Section 205... Interpretive Opinions § 205.201 System operator. The system operator can be the Secretary of State of a State... system refers to operation by the Secretary of State of a State, but the definition in (c)(11) of...

9 CFR 205.201 - System operator.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 9 Animals and Animal Products 2 2012-01-01 2012-01-01 false System operator. 205.201 Section 205... Interpretive Opinions § 205.201 System operator. The system operator can be the Secretary of State of a State... system refers to operation by the Secretary of State of a State, but the definition in (c)(11) of...

9 CFR 205.201 - System operator.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false System operator. 205.201 Section 205... Interpretive Opinions § 205.201 System operator. The system operator can be the Secretary of State of a State... system refers to operation by the Secretary of State of a State, but the definition in (c)(11) of...

Operator function modeling: Cognitive task analysis, modeling and intelligent aiding in supervisory control systems

NASA Technical Reports Server (NTRS)

Mitchell, Christine M.

1990-01-01

The design, implementation, and empirical evaluation of task-analytic models and intelligent aids for operators in the control of complex dynamic systems, specifically aerospace systems, are studied. Three related activities are included: (1) the models of operator decision making in complex and predominantly automated space systems were used and developed; (2) the Operator Function Model (OFM) was used to represent operator activities; and (3) Operator Function Model Expert System (OFMspert), a stand-alone knowledge-based system was developed, that interacts with a human operator in a manner similar to a human assistant in the control of aerospace systems. OFMspert is an architecture for an operator's assistant that uses the OFM as its system and operator knowledge base and a blackboard paradigm of problem solving to dynamically generate expectations about upcoming operator activities and interpreting actual operator actions. An experiment validated the OFMspert's intent inferencing capability and showed that it inferred the intentions of operators in ways comparable to both a human expert and operators themselves. OFMspert was also augmented with control capabilities. An interface allowed the operator to interact with OFMspert, delegating as much or as little control responsibility as the operator chose. With its design based on the OFM, OFMspert's control capabilities were available at multiple levels of abstraction and allowed the operator a great deal of discretion over the amount and level of delegated control. An experiment showed that overall system performance was comparable for teams consisting of two human operators versus a human operator and OFMspert team.

Electronic Performance Support for Operational Systems: A Case Study of the Link Monitor and Control Operator Assistant

NASA Technical Reports Server (NTRS)

Hill, Randall W., Jr.; Cooper, Lynne P.

1993-01-01

For complex operational systems, help needs to come from the inside out. It is often not realistic to call a help desk for problems that need immediate attention, especially for tasks that put a heavy cognitive load on the system operator. This session addresses the issues associated with providing electronic performance support for operational systems, including situations where the system is already fielded and can only change through evolution rather than revolution. We present a case study based on our experiences in developing the Link Monitor and Control Operator Assistant for NASA's Deep Space Network (DSN). The goals of the Operator Assistant are to improve the operability of the system and increase the efficiency of mission operations.

Automated Instructional Management Systems (AIMS) Version III, Operator's Guide.

ERIC Educational Resources Information Center

New York Inst. of Tech., Old Westbury.

This manual gives the instructions necessary to understand and operate the Automated Instructional Management System (AIMS), utilizing IBM System 360, Model 30/Release 20 Disk Operating System, and the OpScan 100 System Reader and Tape Unit. It covers the AIMS III system initialization, system and operational input, requirements, master response…

49 CFR 1580.5 - Inspection authority.

Code of Federal Regulations, 2010 CFR

2010-10-01

... railroad carrier that operates rolling equipment on track that is part of the general railroad system of... rail operator, whether operating on or off the general railroad system of transportation. (7) Each... railroad system of transportation. (8) Each operator of a rail transit system that is not operating on...

Method and Apparatus Providing Deception and/or Altered Operation in an Information System Operating System

DOEpatents

Cohen, Fred; Rogers, Deanna T.; Neagoe, Vicentiu

2008-10-14

A method and/or system and/or apparatus providing deception and/or execution alteration in an information system. In specific embodiments, deceptions and/or protections are provided by intercepting and/or modifying operation of one or more system calls of an operating system.

14 CFR 25.1333 - Instrument systems.

Code of Federal Regulations, 2012 CFR

2012-01-01

.... For systems that operate the instruments required by § 25.1303(b) which are located at each pilot's... operating systems which are independent of the operating systems at other flight crew stations, or other...) Additional instruments, systems, or equipment may not be connected to the operating systems for the required...

14 CFR 25.1333 - Instrument systems.

Code of Federal Regulations, 2014 CFR

2014-01-01

.... For systems that operate the instruments required by § 25.1303(b) which are located at each pilot's... operating systems which are independent of the operating systems at other flight crew stations, or other...) Additional instruments, systems, or equipment may not be connected to the operating systems for the required...

14 CFR 25.1333 - Instrument systems.

Code of Federal Regulations, 2011 CFR

2011-01-01

.... For systems that operate the instruments required by § 25.1303(b) which are located at each pilot's... operating systems which are independent of the operating systems at other flight crew stations, or other...) Additional instruments, systems, or equipment may not be connected to the operating systems for the required...

14 CFR 25.1333 - Instrument systems.

Code of Federal Regulations, 2013 CFR

2013-01-01

.... For systems that operate the instruments required by § 25.1303(b) which are located at each pilot's... operating systems which are independent of the operating systems at other flight crew stations, or other...) Additional instruments, systems, or equipment may not be connected to the operating systems for the required...

14 CFR 25.1333 - Instrument systems.

Code of Federal Regulations, 2010 CFR

2010-01-01

.... For systems that operate the instruments required by § 25.1303(b) which are located at each pilot's... operating systems which are independent of the operating systems at other flight crew stations, or other...) Additional instruments, systems, or equipment may not be connected to the operating systems for the required...

Multiple operating system rotation environment moving target defense

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

Evans, Nathaniel; Thompson, Michael

Systems and methods for providing a multiple operating system rotation environment ("MORE") moving target defense ("MTD") computing system are described. The MORE-MTD system provides enhanced computer system security through a rotation of multiple operating systems. The MORE-MTD system increases attacker uncertainty, increases the cost of attacking the system, reduces the likelihood of an attacker locating a vulnerability, and reduces the exposure time of any located vulnerability. The MORE-MTD environment is effectuated by rotation of the operating systems at a given interval. The rotating operating systems create a consistently changing attack surface for remote attackers.

Influence of System Operation Method on CO2 Emissions of PV/Solar Heat/Cogeneration System

NASA Astrophysics Data System (ADS)

Oke, Shinichiro; Kemmoku, Yoshishige; Takikawa, Hirofumi; Sakakibara, Tateki

A PV/solar heat/cogeneration system is assumed to be installed in a hotel. The system is operated with various operation methods: CO2 minimum operation, fees minimum operation, seasonal operation, daytime operation and heat demand following operation. Of these five operations, the former two are virtual operations that are operated with the dynamic programming method, and the latter three are actual operations. Computer simulation is implemented using hourly data of solar radiation intensity, atmospheric temperature, electric, cooling, heating and hot water supply demands for one year, and the life-cycle CO2 emission and the total cost are calculated for every operations. The calculation results show that the virtual two and the actual three operations reduce the life-cycle CO2 emission by 21% and 13% compared with the conventional system, respectively. In regard to both the CO2 emission and the cost, there is no significant difference between the virtual two operation methods or among actual three operation methods.

Measurement of SIFT operating system overhead

NASA Technical Reports Server (NTRS)

Palumbo, D. L.; Butler, R. W.

1985-01-01

The overhead of the software implemented fault tolerance (SIFT) operating system was measured. Several versions of the operating system evolved. Each version represents different strategies employed to improve the measured performance. Three of these versions are analyzed. The internal data structures of the operating systems are discussed. The overhead of the SIFT operating system was found to be of two types: vote overhead and executive task overhead. Both types of overhead were found to be significant in all versions of the system. Improvements substantially reduced this overhead; even with these improvements, the operating system consumed well over 50% of the available processing time.

Multitasking operating systems for microprocessors

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

Cramer, T.

1981-01-01

Microprocessors, because of their low cost, low power consumption, and small size, have caused an explosion in the number of innovative computer applications. Although there is a great deal of variation in microprocessor applications software, there is relatively little variation in the operating-system-level software from one application to the next. Nonetheless, operating system software, especially when multitasking is involved, can be very time consuming and expensive to develop. The major microprocessor manufacturers have acknowledged the need for operating systems in microprocessor applications and are now supplying real-time multitasking operating system software that is adaptable to a wide variety of usermore » systems. Use of this existing operating system software will decrease the number of redundant operating system development efforts, thus freeing programmers to work on more creative and productive problems. This paper discusses the basic terminology and concepts involved with multitasking operating systems. It is intended to provide a general understanding of the subject, so that the reader will be prepared to evaluate specific operating system software according to his or her needs. 2 references.« less

Characteristics of Operational Space Weather Forecasting: Observations and Models

NASA Astrophysics Data System (ADS)

Berger, Thomas; Viereck, Rodney; Singer, Howard; Onsager, Terry; Biesecker, Doug; Rutledge, Robert; Hill, Steven; Akmaev, Rashid; Milward, George; Fuller-Rowell, Tim

2015-04-01

In contrast to research observations, models and ground support systems, operational systems are characterized by real-time data streams and run schedules, with redundant backup systems for most elements of the system. We review the characteristics of operational space weather forecasting, concentrating on the key aspects of ground- and space-based observations that feed models of the coupled Sun-Earth system at the NOAA/Space Weather Prediction Center (SWPC). Building on the infrastructure of the National Weather Service, SWPC is working toward a fully operational system based on the GOES weather satellite system (constant real-time operation with back-up satellites), the newly launched DSCOVR satellite at L1 (constant real-time data network with AFSCN backup), and operational models of the heliosphere, magnetosphere, and ionosphere/thermosphere/mesophere systems run on the Weather and Climate Operational Super-computing System (WCOSS), one of the worlds largest and fastest operational computer systems that will be upgraded to a dual 2.5 Pflop system in 2016. We review plans for further operational space weather observing platforms being developed in the context of the Space Weather Operations Research and Mitigation (SWORM) task force in the Office of Science and Technology Policy (OSTP) at the White House. We also review the current operational model developments at SWPC, concentrating on the differences between the research codes and the modified real-time versions that must run with zero fault tolerance on the WCOSS systems. Understanding the characteristics and needs of the operational forecasting community is key to producing research into the coupled Sun-Earth system with maximal societal benefit.

75 FR 11918 - Hewlett Pachard Company, Business Critical Systems, Mission Critical Business Software Division...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-12

... Pachard Company, Business Critical Systems, Mission Critical Business Software Division, Openvms Operating... Business Software Division, Openvms Operating System Development Group, Including an Employee Operating Out... Company, Business Critical Systems, Mission Critical Business Software Division, OpenVMS Operating System...

Transitioning to Integrated Modular Avionics with a Mission Management System

DTIC Science & Technology

2000-10-01

software structure, which is based on the use of a of interchangeable processing modules of a limited COTS Real - Time Operating System . number of...open standardised interfaces system hardware or the Real - Time Operating System directly supports the use of COTS components, which implementation, to...System RTOS Real - Time Operating System SMBP System Management Blueprint Interface SMOS System Management to Operating System Interface Figure 2: The ASAAC

20 CFR 662.430 - Under what conditions may One-Stop operators designated to operate in a One-Stop delivery system...

Code of Federal Regulations, 2011 CFR

2011-04-01

... designated to operate in a One-Stop delivery system established prior to the enactment of WIA be designated... DESCRIPTION OF THE ONE-STOP SYSTEM UNDER TITLE I OF THE WORKFORCE INVESTMENT ACT One-Stop Operators § 662.430 Under what conditions may One-Stop operators designated to operate in a One-Stop delivery system...

20 CFR 662.430 - Under what conditions may One-Stop operators designated to operate in a One-Stop delivery system...

Code of Federal Regulations, 2010 CFR

2010-04-01

... designated to operate in a One-Stop delivery system established prior to the enactment of WIA be designated... DESCRIPTION OF THE ONE-STOP SYSTEM UNDER TITLE I OF THE WORKFORCE INVESTMENT ACT One-Stop Operators § 662.430 Under what conditions may One-Stop operators designated to operate in a One-Stop delivery system...

A Multiprocessor Operating System Simulator

NASA Technical Reports Server (NTRS)

Johnston, Gary M.; Campbell, Roy H.

1988-01-01

This paper describes a multiprocessor operating system simulator that was developed by the authors in the Fall semester of 1987. The simulator was built in response to the need to provide students with an environment in which to build and test operating system concepts as part of the coursework of a third-year undergraduate operating systems course. Written in C++, the simulator uses the co-routine style task package that is distributed with the AT&T C++ Translator to provide a hierarchy of classes that represents a broad range of operating system software and hardware components. The class hierarchy closely follows that of the 'Choices' family of operating systems for loosely- and tightly-coupled multiprocessors. During an operating system course, these classes are refined and specialized by students in homework assignments to facilitate experimentation with different aspects of operating system design and policy decisions. The current implementation runs on the IBM RT PC under 4.3bsd UNIX.

14 CFR 29.672 - Stability augmentation, automatic, and power-operated systems.

Code of Federal Regulations, 2011 CFR

2011-01-01

... power-operated systems. 29.672 Section 29.672 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION... Construction Control Systems § 29.672 Stability augmentation, automatic, and power-operated systems. If the functioning of stability augmentation or other automatic or power-operated system is necessary to show...

14 CFR 29.672 - Stability augmentation, automatic, and power-operated systems.

Code of Federal Regulations, 2014 CFR

2014-01-01

... power-operated systems. 29.672 Section 29.672 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION... Construction Control Systems § 29.672 Stability augmentation, automatic, and power-operated systems. If the functioning of stability augmentation or other automatic or power-operated system is necessary to show...

14 CFR 27.672 - Stability augmentation, automatic, and power-operated systems.

Code of Federal Regulations, 2014 CFR

2014-01-01

... power-operated systems. 27.672 Section 27.672 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION... Construction Control Systems § 27.672 Stability augmentation, automatic, and power-operated systems. If the functioning of stability augmentation or other automatic or power-operated systems is necessary to show...

14 CFR 29.672 - Stability augmentation, automatic, and power-operated systems.

Code of Federal Regulations, 2010 CFR

2010-01-01

... power-operated systems. 29.672 Section 29.672 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION... Construction Control Systems § 29.672 Stability augmentation, automatic, and power-operated systems. If the functioning of stability augmentation or other automatic or power-operated system is necessary to show...

14 CFR 27.672 - Stability augmentation, automatic, and power-operated systems.

Code of Federal Regulations, 2011 CFR

2011-01-01

... power-operated systems. 27.672 Section 27.672 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION... Construction Control Systems § 27.672 Stability augmentation, automatic, and power-operated systems. If the functioning of stability augmentation or other automatic or power-operated systems is necessary to show...

14 CFR 29.672 - Stability augmentation, automatic, and power-operated systems.

Code of Federal Regulations, 2012 CFR

2012-01-01

... power-operated systems. 29.672 Section 29.672 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION... Construction Control Systems § 29.672 Stability augmentation, automatic, and power-operated systems. If the functioning of stability augmentation or other automatic or power-operated system is necessary to show...

14 CFR 27.672 - Stability augmentation, automatic, and power-operated systems.

Code of Federal Regulations, 2010 CFR

2010-01-01

... power-operated systems. 27.672 Section 27.672 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION... Construction Control Systems § 27.672 Stability augmentation, automatic, and power-operated systems. If the functioning of stability augmentation or other automatic or power-operated systems is necessary to show...

14 CFR 27.672 - Stability augmentation, automatic, and power-operated systems.

Code of Federal Regulations, 2012 CFR

2012-01-01

... power-operated systems. 27.672 Section 27.672 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION... Construction Control Systems § 27.672 Stability augmentation, automatic, and power-operated systems. If the functioning of stability augmentation or other automatic or power-operated systems is necessary to show...

OFMTutor: An operator function model intelligent tutoring system

NASA Technical Reports Server (NTRS)

Jones, Patricia M.

1989-01-01

The design, implementation, and evaluation of an Operator Function Model intelligent tutoring system (OFMTutor) is presented. OFMTutor is intended to provide intelligent tutoring in the context of complex dynamic systems for which an operator function model (OFM) can be constructed. The human operator's role in such complex, dynamic, and highly automated systems is that of a supervisory controller whose primary responsibilities are routine monitoring and fine-tuning of system parameters and occasional compensation for system abnormalities. The automated systems must support the human operator. One potentially useful form of support is the use of intelligent tutoring systems to teach the operator about the system and how to function within that system. Previous research on intelligent tutoring systems (ITS) is considered. The proposed design for OFMTutor is presented, and an experimental evaluation is described.

Autonomous Operations System: Development and Application

NASA Technical Reports Server (NTRS)

Toro Medina, Jaime A.; Wilkins, Kim N.; Walker, Mark; Stahl, Gerald M.

2016-01-01

Autonomous control systems provides the ability of self-governance beyond the conventional control system. As the complexity of mechanical and electrical systems increases, there develops a natural drive for developing robust control systems to manage complicated operations. By closing the bridge between conventional automated systems to knowledge based self-awareness systems, nominal control of operations can evolve into relying on safe critical mitigation processes to support any off-nominal behavior. Current research and development efforts lead by the Autonomous Propellant Loading (APL) group at NASA Kennedy Space Center aims to improve cryogenic propellant transfer operations by developing an automated control and health monitoring system. As an integrated systems, the center aims to produce an Autonomous Operations System (AOS) capable of integrating health management operations with automated control to produce a fully autonomous system.

EOS: A project to investigate the design and construction of real-time distributed Embedded Operating Systems

NASA Technical Reports Server (NTRS)

Campbell, R. H.; Essick, Ray B.; Johnston, Gary; Kenny, Kevin; Russo, Vince

1987-01-01

Project EOS is studying the problems of building adaptable real-time embedded operating systems for the scientific missions of NASA. Choices (A Class Hierarchical Open Interface for Custom Embedded Systems) is an operating system designed and built by Project EOS to address the following specific issues: the software architecture for adaptable embedded parallel operating systems, the achievement of high-performance and real-time operation, the simplification of interprocess communications, the isolation of operating system mechanisms from one another, and the separation of mechanisms from policy decisions. Choices is written in C++ and runs on a ten processor Encore Multimax. The system is intended for use in constructing specialized computer applications and research on advanced operating system features including fault tolerance and parallelism.

Water Distribution System Operation and Maintenance. A Field Study Training Program. Second Edition.

ERIC Educational Resources Information Center

Kerri, Kenneth D.; And Others

Proper installation, inspection, operation, maintenance, repair and management of water distribution systems have a significant impact on the operation and maintenance cost and effectiveness of the systems. The objective of this manual is to provide water distribution system operators with the knowledge and skills required to operate and maintain…

Clearing a Path: The 16-Bit Operating System Jungle Offers Confusion, Not Standardization.

ERIC Educational Resources Information Center

Pournelle, Jerry

1984-01-01

Discusses the design and limited uses of the Pascal, MS-DOS, CP/M, and PC-DOS operating systems as standard operating systems for 16-bit microprocessors, especially with the more sophisticated microcomputers currently being developed. Advantages and disadvantages of Unix--a multitasking, multiuser operating system--as a standard operating system…

49 CFR 1544.211 - Use of X-ray systems.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 9 2012-10-01 2012-10-01 false Use of X-ray systems. 1544.211 Section 1544.211... COMMERCIAL OPERATORS Operations § 1544.211 Use of X-ray systems. (a) TSA authorization required. No aircraft operator may use any X-ray system within the United States or under the aircraft operator's operational...

Comparing Two Tools for Mobile-Device Forensics

DTIC Science & Technology

2017-09-01

baseline standard. 2.4 Mobile Operating Systems "A mobile operating system is an operating system that is specifically designed to run on mobile devices... run on mobile devices" [7]. There are many different types of mobile operating systems and they are constantly changing, which means an operating...to this is that the security features make forensic analysis more difficult [11]. 2.4.2 iPhone "The iPhone runs an operating system called iOS. It is a

Operations management system

NASA Technical Reports Server (NTRS)

Brandli, A. E.; Eckelkamp, R. E.; Kelly, C. M.; Mccandless, W.; Rue, D. L.

1990-01-01

The objective of an operations management system is to provide an orderly and efficient method to operate and maintain aerospace vehicles. Concepts are described for an operations management system and the key technologies are highlighted which will be required if this capability is brought to fruition. Without this automation and decision aiding capability, the growing complexity of avionics will result in an unmanageable workload for the operator, ultimately threatening mission success or survivability of the aircraft or space system. The key technologies include expert system application to operational tasks such as replanning, equipment diagnostics and checkout, global system management, and advanced man machine interfaces. The economical development of operations management systems, which are largely software, will require advancements in other technological areas such as software engineering and computer hardware.

21 CFR 111.110 - What quality control operations are required for laboratory operations associated with the...

Code of Federal Regulations, 2010 CFR

2010-04-01

... laboratory operations associated with the production and process control system? 111.110 Section 111.110 Food... OPERATIONS FOR DIETARY SUPPLEMENTS Production and Process Control System: Requirements for Quality Control... production and process control system? Quality control operations for laboratory operations associated with...

49 CFR 325.37 - Location and operation of sound level measurement system; highway operations.

Code of Federal Regulations, 2013 CFR

2013-10-01

... system; highway operations. 325.37 Section 325.37 Transportation Other Regulations Relating to...; Highway Operations § 325.37 Location and operation of sound level measurement system; highway operations..., the holder must orient himself/herself relative to the highway in a manner consistent with the...

49 CFR 325.37 - Location and operation of sound level measurement system; highway operations.

Code of Federal Regulations, 2012 CFR

2012-10-01

... system; highway operations. 325.37 Section 325.37 Transportation Other Regulations Relating to...; Highway Operations § 325.37 Location and operation of sound level measurement system; highway operations..., the holder must orient himself/herself relative to the highway in a manner consistent with the...

49 CFR 325.37 - Location and operation of sound level measurement system; highway operations.

Code of Federal Regulations, 2014 CFR

2014-10-01

... system; highway operations. 325.37 Section 325.37 Transportation Other Regulations Relating to...; Highway Operations § 325.37 Location and operation of sound level measurement system; highway operations..., the holder must orient himself/herself relative to the highway in a manner consistent with the...

14 CFR 25.961 - Fuel system hot weather operation.

Code of Federal Regulations, 2010 CFR

2010-01-01

... AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant Fuel System § 25.961 Fuel system hot weather operation. (a) The fuel system must perform satisfactorily in hot weather operation. This... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Fuel system hot weather operation. 25.961...

14 CFR 25.961 - Fuel system hot weather operation.

Code of Federal Regulations, 2013 CFR

2013-01-01

... AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant Fuel System § 25.961 Fuel system hot weather operation. (a) The fuel system must perform satisfactorily in hot weather operation. This... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Fuel system hot weather operation. 25.961...

14 CFR 25.961 - Fuel system hot weather operation.

Code of Federal Regulations, 2012 CFR

2012-01-01

... AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant Fuel System § 25.961 Fuel system hot weather operation. (a) The fuel system must perform satisfactorily in hot weather operation. This... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Fuel system hot weather operation. 25.961...

14 CFR 25.961 - Fuel system hot weather operation.

Code of Federal Regulations, 2011 CFR

2011-01-01

... AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant Fuel System § 25.961 Fuel system hot weather operation. (a) The fuel system must perform satisfactorily in hot weather operation. This... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Fuel system hot weather operation. 25.961...

14 CFR 25.961 - Fuel system hot weather operation.

Code of Federal Regulations, 2014 CFR

2014-01-01

... AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant Fuel System § 25.961 Fuel system hot weather operation. (a) The fuel system must perform satisfactorily in hot weather operation. This... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Fuel system hot weather operation. 25.961...

46 CFR 113.35-13 - Mechanical engine order telegraph systems; operation.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 4 2014-10-01 2014-10-01 false Mechanical engine order telegraph systems; operation...) ELECTRICAL ENGINEERING COMMUNICATION AND ALARM SYSTEMS AND EQUIPMENT Engine Order Telegraph Systems § 113.35-13 Mechanical engine order telegraph systems; operation. If more than one transmitter operates a...

46 CFR 113.35-13 - Mechanical engine order telegraph systems; operation.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 4 2012-10-01 2012-10-01 false Mechanical engine order telegraph systems; operation...) ELECTRICAL ENGINEERING COMMUNICATION AND ALARM SYSTEMS AND EQUIPMENT Engine Order Telegraph Systems § 113.35-13 Mechanical engine order telegraph systems; operation. If more than one transmitter operates a...

46 CFR 113.35-13 - Mechanical engine order telegraph systems; operation.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 4 2011-10-01 2011-10-01 false Mechanical engine order telegraph systems; operation...) ELECTRICAL ENGINEERING COMMUNICATION AND ALARM SYSTEMS AND EQUIPMENT Engine Order Telegraph Systems § 113.35-13 Mechanical engine order telegraph systems; operation. If more than one transmitter operates a...

46 CFR 113.35-13 - Mechanical engine order telegraph systems; operation.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 4 2013-10-01 2013-10-01 false Mechanical engine order telegraph systems; operation...) ELECTRICAL ENGINEERING COMMUNICATION AND ALARM SYSTEMS AND EQUIPMENT Engine Order Telegraph Systems § 113.35-13 Mechanical engine order telegraph systems; operation. If more than one transmitter operates a...

14 CFR 25.672 - Stability augmentation and automatic and power-operated systems.

Code of Federal Regulations, 2013 CFR

2013-01-01

... power-operated systems. 25.672 Section 25.672 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION... Construction Control Systems § 25.672 Stability augmentation and automatic and power-operated systems. If the functioning of stability augmentation or other automatic or power-operated systems is necessary to show...

Operationally efficient propulsion system study (OEPSS) data book. Volume 7; Launch Operations Index (LOI) Design Features and Options

NASA Technical Reports Server (NTRS)

Ziese, James M.

1992-01-01

A design tool of figure of merit was developed that allows the operability of a propulsion system design to be measured. This Launch Operations Index (LOI) relates Operations Efficiency to System Complexity. The figure of Merit can be used by conceptual designers to compare different propulsion system designs based on their impact on launch operations. The LOI will improve the design process by making sure direct launch operations experience is a necessary feedback to the design process.

GRAM 88 - 4D GLOBAL REFERENCE ATMOSPHERE MODEL-1988

NASA Technical Reports Server (NTRS)

Johnson, D. L.

1994-01-01

The Four-D Global Reference Atmosphere program was developed from an empirical atmospheric model which generates values for pressure, density, temperature, and winds from surface level to orbital altitudes. This program can generate altitude profiles of atmospheric parameters along any simulated trajectory through the atmosphere. The program was developed for design applications in the Space Shuttle program, such as the simulation of external tank re-entry trajectories. Other potential applications are global circulation and diffusion studies; also the generation of profiles for comparison with other atmospheric measurement techniques such as satellite measured temperature profiles and infrasonic measurement of wind profiles. GRAM-88 is the latest version of the software GRAM. The software GRAM-88 contains a number of changes that have improved the model statistics, in particular, the small scale density perturbation statistics. It also corrected a low latitude grid problem as well as the SCIDAT data base. Furthermore, GRAM-88 now uses the U.S. Standard Atmosphere 1976 as a comparison standard rather than the US62 used in other versions. The program is an amalgamation of two empirical atmospheric models for the low (25km) and the high (90km) atmosphere, with a newly developed latitude-longitude dependent model for the middle atmosphere. The Jacchia (1970) model simulates the high atmospheric region above 115km. The Jacchia program sections are in separate subroutines so that other thermosphericexospheric models could easily be adapted if required for special applications. The improved code eliminated the calculation of geostrophic winds above 125 km altitude from the model. The atmospheric region between 30km and 90km is simulated by a latitude-longitude dependent empirical model modification of the latitude dependent empirical model of Groves (1971). A fairing technique between 90km and 115km accomplished a smooth transition between the modified Groves values and the Jacchia values. Below 25km the atmospheric parameters are computed by the 4-D worldwide atmospheric model of Spiegler and Fowler (1972). This data set is not included. GRAM-88 incorporates a hydrostatic/gas law check in the 0-30 km altitude range to flag and change any bad data points. Between 5km and 30km, an interpolation scheme is used between the 4-D results and the modified Groves values. The output parameters consist of components for: (1) latitude, longitude, and altitude dependent monthly and annual means, (2) quasi-biennial oscillations (QBO), and (3) random perturbations to partially simulate the variability due to synoptic, diurnal, planetary wave, and gravity wave variations. Quasi-biennial and random variation perturbations are computed from parameters determined by various empirical studies and are added to the monthly mean values. The GRAM-88 program is for batch execution on the IBM 3084. It is written in STANDARD FORTRAN 77 under the MVS/XA operating system. The IBM DISPLA graphics routines are necessary for graphical output. The program was developed in 1988.

From Operating-System Correctness to Pervasively Verified Applications

NASA Astrophysics Data System (ADS)

Daum, Matthias; Schirmer, Norbert W.; Schmidt, Mareike

Though program verification is known and has been used for decades, the verification of a complete computer system still remains a grand challenge. Part of this challenge is the interaction of application programs with the operating system, which is usually entrusted with retrieving input data from and transferring output data to peripheral devices. In this scenario, the correct operation of the applications inherently relies on operating-system correctness. Based on the formal correctness of our real-time operating system Olos, this paper describes an approach to pervasively verify applications running on top of the operating system.

Use of artificial intelligence in supervisory control

NASA Technical Reports Server (NTRS)

Cohen, Aaron; Erickson, Jon D.

1989-01-01

Viewgraphs describing the design and testing of an intelligent decision support system called OFMspert are presented. In this expert system, knowledge about the human operator is represented through an operator/system model referred to as the OFM (Operator Function Model). OFMspert uses the blackboard model of problem solving to maintain a dynamic representation of operator goals, plans, tasks, and actions given previous operator actions and current system state. Results of an experiment to assess OFMspert's intent inferencing capability are outlined. Finally, the overall design philosophy for an intelligent tutoring system (OFMTutor) for operators of complex dynamic systems is summarized.

Making adaptable systems work for mission operations: A case study

NASA Technical Reports Server (NTRS)

Holder, Barbara E.; Levesque, Michael E.

1993-01-01

The Advanced Multimission Operations System (AMMOS) at NASA's Jet Propulsion Laboratory is based on a highly adaptable multimission ground data system (MGDS) for mission operations. The goal for MGDS is to support current flight project science and engineering personnel and to meet the demands of future missions while reducing associated operations and software development costs. MGDS has become a powerful and flexible mission operations system by using a network of heterogeneous workstations, emerging open system standards, and selecting an adaptable tools-based architecture. Challenges in developing adaptable systems for mission operations and the benefits of this approach are described.

Small Water System Operations and Maintenance. A Field Study Training Program. Second Edition.

ERIC Educational Resources Information Center

Kerri, Kenneth D.; And Others

Proper installation, inspection, operation, maintenance, repair and management of small water systems have a significant impact on the operation and maintenance cost and effectiveness of the systems. The objective of this manual is to provide small water system operators with the knowledge and skills required to operate and maintain these systems…

49 CFR 192.621 - Maximum allowable operating pressure: High-pressure distribution systems.

Code of Federal Regulations, 2012 CFR

2012-10-01

... STANDARDS Operations § 192.621 Maximum allowable operating pressure: High-pressure distribution systems. (a) No person may operate a segment of a high pressure distribution system at a pressure that exceeds the... segment of a distribution system otherwise designed to operate at over 60 p.s.i. (414 kPa) gage, unless...

40 CFR 63.3556 - How do I establish the emission capture system and add-on control device operating limits during...

Code of Federal Regulations, 2014 CFR

2014-07-01

... capture system and add-on control device operating limits during the performance test? 63.3556 Section 63... system and add-on control device operating limits during the performance test? During the performance... of key parameters of the valve operating system (e.g., solenoid valve operation, air pressure...

49 CFR 192.621 - Maximum allowable operating pressure: High-pressure distribution systems.

Code of Federal Regulations, 2011 CFR

2011-10-01

... STANDARDS Operations § 192.621 Maximum allowable operating pressure: High-pressure distribution systems. (a) No person may operate a segment of a high pressure distribution system at a pressure that exceeds the... segment of a distribution system otherwise designed to operate at over 60 p.s.i. (414 kPa) gage, unless...

14 CFR 27.695 - Power boost and power-operated control system.

Code of Federal Regulations, 2014 CFR

2014-01-01

... Systems § 27.695 Power boost and power-operated control system. (a) If a power boost or power-operated... failure of all engines. (b) Each alternate system may be a duplicate power portion or a manually operated... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Power boost and power-operated control...

14 CFR 29.695 - Power boost and power-operated control system.

Code of Federal Regulations, 2012 CFR

2012-01-01

... Systems § 29.695 Power boost and power-operated control system. (a) If a power boost or power-operated... failure of all engines. (b) Each alternate system may be a duplicate power portion or a manually operated... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Power boost and power-operated control...

40 CFR 63.3546 - How do I establish the emission capture system and add-on control device operating limits during...

Code of Federal Regulations, 2013 CFR

2013-07-01

... system and add-on control device operating limits during the performance test? 63.3546 Section 63.3546... of key parameters of the valve operating system (e.g., solenoid valve operation, air pressure... minimum operating limit for that specific capture device or system of multiple capture devices. The...

40 CFR 63.3546 - How do I establish the emission capture system and add-on control device operating limits during...

Code of Federal Regulations, 2014 CFR

2014-07-01

... capture system and add-on control device operating limits during the performance test? 63.3546 Section 63... of key parameters of the valve operating system (e.g., solenoid valve operation, air pressure... minimum operating limit for that specific capture device or system of multiple capture devices. The...

49 CFR 192.621 - Maximum allowable operating pressure: High-pressure distribution systems.

Code of Federal Regulations, 2010 CFR

2010-10-01

... STANDARDS Operations § 192.621 Maximum allowable operating pressure: High-pressure distribution systems. (a) No person may operate a segment of a high pressure distribution system at a pressure that exceeds the... segment of a distribution system otherwise designed to operate at over 60 p.s.i. (414 kPa) gage, unless...

49 CFR 192.621 - Maximum allowable operating pressure: High-pressure distribution systems.

Code of Federal Regulations, 2014 CFR

2014-10-01

... STANDARDS Operations § 192.621 Maximum allowable operating pressure: High-pressure distribution systems. (a) No person may operate a segment of a high pressure distribution system at a pressure that exceeds the... segment of a distribution system otherwise designed to operate at over 60 p.s.i. (414 kPa) gage, unless...

14 CFR 29.695 - Power boost and power-operated control system.

Code of Federal Regulations, 2014 CFR

2014-01-01

... Systems § 29.695 Power boost and power-operated control system. (a) If a power boost or power-operated... failure of all engines. (b) Each alternate system may be a duplicate power portion or a manually operated... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Power boost and power-operated control...

14 CFR 27.695 - Power boost and power-operated control system.

Code of Federal Regulations, 2011 CFR

2011-01-01

... Systems § 27.695 Power boost and power-operated control system. (a) If a power boost or power-operated... failure of all engines. (b) Each alternate system may be a duplicate power portion or a manually operated... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Power boost and power-operated control...

40 CFR 63.3546 - How do I establish the emission capture system and add-on control device operating limits during...

Code of Federal Regulations, 2012 CFR

2012-07-01

... capture system and add-on control device operating limits during the performance test? 63.3546 Section 63... of key parameters of the valve operating system (e.g., solenoid valve operation, air pressure... minimum operating limit for that specific capture device or system of multiple capture devices. The...

14 CFR 29.695 - Power boost and power-operated control system.

Code of Federal Regulations, 2011 CFR

2011-01-01

... Systems § 29.695 Power boost and power-operated control system. (a) If a power boost or power-operated... failure of all engines. (b) Each alternate system may be a duplicate power portion or a manually operated... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Power boost and power-operated control...

14 CFR 29.695 - Power boost and power-operated control system.

Code of Federal Regulations, 2010 CFR

2010-01-01

... Systems § 29.695 Power boost and power-operated control system. (a) If a power boost or power-operated... failure of all engines. (b) Each alternate system may be a duplicate power portion or a manually operated... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Power boost and power-operated control...

40 CFR 63.3556 - How do I establish the emission capture system and add-on control device operating limits during...

Code of Federal Regulations, 2012 CFR

2012-07-01

... capture system and add-on control device operating limits during the performance test? 63.3556 Section 63... system and add-on control device operating limits during the performance test? During the performance... of key parameters of the valve operating system (e.g., solenoid valve operation, air pressure...

49 CFR 192.621 - Maximum allowable operating pressure: High-pressure distribution systems.

Code of Federal Regulations, 2013 CFR

2013-10-01

... STANDARDS Operations § 192.621 Maximum allowable operating pressure: High-pressure distribution systems. (a) No person may operate a segment of a high pressure distribution system at a pressure that exceeds the... segment of a distribution system otherwise designed to operate at over 60 p.s.i. (414 kPa) gage, unless...

14 CFR 27.695 - Power boost and power-operated control system.

Code of Federal Regulations, 2012 CFR

2012-01-01

... Systems § 27.695 Power boost and power-operated control system. (a) If a power boost or power-operated... failure of all engines. (b) Each alternate system may be a duplicate power portion or a manually operated... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Power boost and power-operated control...

14 CFR 27.695 - Power boost and power-operated control system.

Code of Federal Regulations, 2010 CFR

2010-01-01

... Systems § 27.695 Power boost and power-operated control system. (a) If a power boost or power-operated... failure of all engines. (b) Each alternate system may be a duplicate power portion or a manually operated... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Power boost and power-operated control...