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Sample records for finger reactive compounds

  1. Characterization of Junín virus particles inactivated by a zinc finger-reactive compound.

    PubMed

    García, Cybele C; Ellenberg, Paula C; Artuso, María C; Scolaro, Luis A; Damonte, Elsa B

    2009-07-01

    Our previous studies reported the inhibitory action against arenaviruses of antiretroviral zinc finger-reactive compounds provided by the National Cancer Institute (USA). These compounds were able to inactivate virions as well as to reduce virus yields from infected cells. Here, the inactivation of the arenavirus Junín (JUNV), agent of Argentine hemorrhagic fever, by the aromatic disulfide NSC20625 was analyzed. The treatment of purified JUNV with this compound eliminated infectivity apparently through irreversible modifications in the matrix Z protein detected by: (a) alterations in the electrophoretic migration profile of Z under non-reducing conditions; (b) an electrodense labeling in the internal layer beneath the envelope and around the matrix Z protein, in negatively stained preparations; (c) changes in the subcellular localization of Z in cells transfected with a recombinant fusion protein JUNVZ-eGFP. The infection of Vero cells with JUNV inactivated particles was blocked at the uncoating of viral nucleocapsid from endosomes, providing new evidence for a functional role of Z in this stage of arenavirus cycle. Furthermore, the inactivated JUNV particles retained the immunoreactivity of the surface glycoprotein GP1 suggesting that this disulfide may be useful in the pursuit of an inactivating agent to obtain a vaccine antigen or diagnostic tool. PMID:19463727

  2. Arenavirus Z protein as an antiviral target: virus inactivation and protein oligomerization by zinc finger-reactive compounds

    PubMed Central

    García, Cybele C.; Djavani, Mahmoud; Topisirovic, Ivan; Borden, Katherine L. B.; Salvato, María S.; Damonte, Elsa B.

    2008-01-01

    Several disulfide-based and azoic compounds have shown antiviral and virucidal properties against arenaviruses in virus yield-inhibition and inactivation assays, respectively. The most effective virucidal agent, the aromatic disulfide NSC20625, was able to inactivate two strains of the prototype arenavirus species Lymphocytic choriomeningitis virus (LCMV). Inactivated viral particles retained the biological functions of the virion envelope glycoproteins in virus binding and uptake, but were unable to perform viral RNA replication. Furthermore, in inactivated virions, the electrophoretic profile of the Z protein was altered when analysed under non-reducing conditions, whereas the patterns of the proteins NP and GP1 remained unaffected. Treatment of a recombinant LCMV Z protein with the virucidal agents induced unfolding and oligomerization of Z to high-molecular-mass aggregates, probably due to metal-ion ejection and the formation of intermolecular disulfide bonds through the cysteine residues of the Z RING finger. NSC20625 also exhibited antiviral properties in LCMV-infected cells without affecting other cellular RING-motif proteins, such as the promyelocytic leukaemia protein PML. Altogether, the investigations described here illustrate the potential of the Z protein as a promising target for therapy and the prospects of the Z-reactive compounds to prevent arenavirus dissemination. PMID:16603524

  3. Chalcogen bonding interactions between reducible sulfur and selenium compounds and models of zinc finger proteins.

    PubMed

    Lutz, Patricia B; Bayse, Craig A

    2016-04-01

    Reducible sulfur and selenium (r-S/Se) compounds, defined as sulfur and selenium compounds not in the lowest -2 oxidation state (e.g., -1 to +6), release Zn(2+) from zinc-sulfur proteins such as zinc fingers (ZFs) and metallothionein. A series of density functional theory calculations was performed on donor-acceptor complexes between r-S/Se compounds and models of the Cys2His2, Cys3His and Cys4 ZF sites. These S⋯S/Se chalcogen bonding interactions consist of the donation of electron density from a S lone pair on the ZF model to a S/Se-X antibonding molecular orbital of the r-S/Se compound. The strength of the interaction was shown to be dependent upon the Lewis basicity of the ZF model (Cys4>Cys3His>Cys2His2) and the Lewis acidity of the r-S/Se compound as measured by the energy of the S/Se-X antibonding orbital. Interactions with the softer r-Se compounds were stronger than the r-S compounds, consistent with the greater reactivity of the former with ZF proteins. PMID:26877152

  4. Reactive spreading: Adsorption, ridging and compound formation

    SciTech Connect

    Saiz, E.; Cannon, R.M.; Tomsia, A.P.

    2000-09-11

    Reactive spreading, in which a chemically active element is added to promote wetting of noble metals on nonmetallic materials, is evaluated. Theories for the energetics and kinetics of the necessary steps involved in spreading are outlined and compared to the steps in compound formation that typically accompany reactive wetting. These include: fluid flow, active metal adsorption, including nonequilibrium effects, and triple line ridging. All of these can be faster than compound nucleation under certain conditions. Analysis and assessment of recently reported experiments on metal/ceramic systems lead to a focus on those conditions under which spreading proceeds ahead of the actual formation of a new phase at the interface. This scenario may be more typical than believed, and perhaps the most effective situation leading to enhanced spreading. A rationale for the pervasive variability and hysteresis observed during high temperature wetting also emerges.

  5. Recent changes in anthropogenic reactive nitrogen compounds

    NASA Astrophysics Data System (ADS)

    Andronache, Constantin

    2014-05-01

    Significant anthropogenic perturbations of the nitrogen cycle are the result of rapid population growth, with mounting need for food and energy production. The increase of reactive nitrogen compounds (such as NOx, HNO3, NH3, and N2O) has a significant impact on human health, environment, and climate. NOx emissions contribute to O3 chemistry, aerosol formation and acidic precipitation. Ammonia is a notable atmospheric pollutant that may deteriorate ecosystems and contribute to respiratory problems. It reacts with acidic gases to form aerosols or is deposited back to ecosystems. The application of fertilizers accounts for most of the N2O production, adding to greenhouse gas emissions. We analyze the change of some reactive nitrogen compounds based on observations, in eastern United States. Results show that the control of NOx and SO2 emissions over the last decades caused a significant decrease of acidic deposition. The nitrate deposition is highest in eastern US, while the ammonium ion concentration is highest in central US regions. Overall, the inorganic nitrogen wet deposition from nitrate and ammonium is enhanced in central, and eastern US. Research shows that sensitive ecosystems in northeastern regions exhibit a slow recovery from the accumulated effects of acidic deposition. Given the growing demand for nitrogen in agriculture and industry, we discuss possible pathways to reduce the impact of excess reactive nitrogen on the environment.

  6. Oxime-induced reactivation of carboxylesterase inhibited by organophosphorus compounds

    SciTech Connect

    Maxwell, D.M.; Lieske, C.N.; Brecht, K.M.

    1993-05-13

    A structure-activity analysis of the ability of oximes to reactivate rat plasma carboxylesterase (CaE) that was inhibited by organophosphorus (OP) compounds revealed that uncharged oximes, such as diacetylmonoxime or monoisonitrosoacetone, were better reactivators than cationic oximes. Cationic oximes that are excellent reactivators of OP-inhibited acetylcholinesteraser such as pyridinium-2-aldoxime or the bis-pyridinium oximes, HI-6 and TMB-4, produced poor reactivation of OP-inhibited CaE. The best uncharged reactivator was diacetylmonoxime which produced complete reactivation at 0.3 mM in 2 hr of CaE that was inhibited by organophosphinates, alkoxy-containing phosphates, and alkoxy-containing phosphonates. Complete reactivation of CaE could be achieved even after inhibition by phosphonates with highly branched alkoxy groups, such as sarin and soman, that undergo rapid aging with acetylcholinesterase. CaE that was inhibited by phosphonates or phosphates that contained aryloxy groups were reactivated to a lower extent. The cause of this decreased reactivation appears to be an oxime-induced aging reaction that competes with the reactivation reaction. This oxime-induced aging reaction is accelerated by electron-withdrawing substituents on the aryloxy groups of phosphonates and by the presence of multiple aryloxy groups on phosphates. Thus, reactivation and aging of OP-inhibited CaE differ from the same processes for OP-inhibited acetylcholinesterase in both their oxime specificity and inhibitor specificity and, presumably, in their underlying mechanisms.

  7. Guanidino compounds generate reactive oxygen species.

    PubMed

    Mori, A; Kohno, M; Masumizu, T; Noda, Y; Packer, L

    1996-09-01

    Methylguanidine, guanidinoacetic acid and guanidinosuccinic acid are endogenous substances in body tissues. Extremely high levels of these substances are known to be related to the pathogenesis of epilepsy and renal failure such as uremia. In this study it was demonstrated that methylguanidine, guanidinoacetic acid and guanidinosuccinic acid, and arginine generate hydroxyl radicals in aqueous solution. These findings suggest that a high level of guanidino compounds accumulating near or within cells such as neurons (in an epileptogenic focus) or nephrons (in uremic patients) may cause free radical damage leading to these clinical disorders. Arginine may have a similar role in the pathogenesis of hyperarginemia. PMID:8886279

  8. Oxime-induced reactivation of carboxylesterase inhibited by organophosphorus compounds

    SciTech Connect

    Maxwell, D.M.; Lieske, C.N.; Brecht, K.M.

    1994-06-01

    A structure-activity analysis of the ability of oximes to reactivate rat plasma carboxylesterase (CaE) that was inhibited by organophosphorus (OP) compounds revealed that uncharged oximes, such as 2,3-butanedione monoxime (diacetylmonoxime) or monoisonitrosoacetone, were better reactivators than cationic oximes. Cationic oximes that are excellent reactivators of OP-inhibited acetylcholinesterase, such as pyridine-2-aldoxime or the bis-pyridine aldoximes, HI-6 and TMB. 4, produced poor reactivation of OP-inhibited CaE. The best uncharged reactivator was 2,3. butanedione monoxime, which produced complete reactivation at 0.3 mM in 2 h of CaE that was inhibited by phosphinates, alkoxy-containing phosphates, and alkoxy-containing phosphonates. Complete reactivation of CaE could be achieved even after inhibition by phosphonates with highly branched alkoxy groups, such as sarin and soman, that undergo rapid aging with acetylcholinesterase. CaE that was inhibited by phosphonates or phosphates that contained aryloxy groups were reactivated to a lesser extent. The cause of this decreased reactivation appears to be an oxime-induced aging reaction that competes with the reactivation reaction. This oxime-induced aging reaction is accelerated by electron-withdrawing substituents on the aryloxy groups of phosphonates and by the presence of multiple aryloxy groups on phosphates. Thus, reactivation and aging of OP-inhibited CaE differ from the same processes for OP- inhibited acetylcholinesterase in both their oxime specificity and inhibitor specificity and, presumably, in their underlying mechanisms.

  9. Hydrodesulfurization reactivities of various sulfur compounds in vacuum gas oil

    SciTech Connect

    Ma, X.; Sakanishi, K.; Mochida, I.

    1996-08-01

    The hydrodesulfurization (HDS) of a vacuum gas oil (VGO) was performed at 360 C (6.9 MPa) over a commercial NiMo catalyst to examine the HDS reactivities of various sulfur compounds which exist in the VGO by means of quantitative pseudo-first-order kinetic analysis. Four representative types of aromatic-skeleton sulfur compounds were observed in the VGO: alkylbenzothiophenes (BTs), alkyldibenzothiophenes (DBTs), alkylphenanthro[4,5-b,c,d]thiophenes (PTs), and alkylbenzonaphthothiophenes (BNTs). Among these, alkyl-BTs exhibited the highest HDS reactivity, whereas alkyl-DBTs with alkyl substituents at the 4 and/or 6 positions appeared to have the least reactivity even though their aromatic-skeleton is smaller than those of both alkyl-PTs and -BNTs. Steric hindrance of alkyl groups at specific positions appears to be a major reason for the low reactivity. Quantum chemical calculations on representative sulfur compounds were carried out to compare molecular parameters with their different HDS reactivities.

  10. Exposure Profiling of Reactive Compounds in Complex Mixtures

    PubMed Central

    Georgieva, Nadia I.; Boysen, Gunnar

    2016-01-01

    Humans are constantly exposed to mixtures, such as tobacco smoke, exhaust from diesel, gasoline or new bio-fuels, containing several thousand compounds, including many known human carcinogens. Covalent binding of reactive compounds or their metabolites to DNA and formation of stable adducts is believed to be the causal link between exposure and carcinogenesis. DNA and protein adducts are well established biomarkers for the internal dose of reactive compounds or their metabolites and are an integral part of science-based risk assessment. However, technical limitations have prevented comprehensive detection of a broad spectrum of adducts simultaneously. Therefore, most studies have focused on measurement of abundant individual adducts. These studies have produced valuable insight into the metabolism of individual carcinogens, but they are insufficient for risk assessment of exposure to complex mixtures. To overcome this limitation, we present herein proof-of-principle for comprehensive exposure assessment, using N-terminal valine adduct profiles as a biomarker. The reported method is based on our previously established immunoaffinity liquid chromatography-tandem mass spectrometry (LC-MS/MS) method with modification to enrich all N-terminal valine alkylated peptides. The method was evaluated using alkylated peptide standards and globin reacted in vitro with alkylating agents (1,2-epoxy-3-butene, 1,2:3,4-diepoxybutane, propylene oxide, styrene oxide, N-ethyl-N-nitrosourea and methyl methanesulfonate), known to form N-terminal valine adducts. To demonstrate proof-of-principle, the method was successfully applied to globin from mice treated with four model compounds. The results suggest that this novel approach might be suitable for in vivo biomonitoring. PMID:23219592

  11. Quantum chemical modelling of reactivity and selectivity of 1,2-dithiolanes towards retroviral and cellular zinc fingers

    NASA Astrophysics Data System (ADS)

    Topol, Igor A.; Nemukhin, Alexander V.; Burt, Stanley K.

    Interactions of 1,2-dithiolane species with zinc-containing sites, which mimic the zinc finger domains of retroviral and the cellular zinc finger proteins, have been investigated by quantum chemistry tools. According to the calculations, the immediate domains of zinc binding sites in the cellular and retroviral zinc fingers interact differently with such agents of the disulphide family. Thus, when approaching the model cellular-type domains, the molecules of 1,2-dithiolanes experience considerable potential barriers along the reaction path. However, these species react practically barrier-less with the model retroviral-type domains at the correlated DFT level. The results of the quantum chemical modelling provide firm support to the selectivity of 1,2-dithiolanes towards retroviral and cellular zinc fingers. This can be of great practical importance for the design of therapeutics that accomplish functional inactivation of the zinc fingers of the human immunodeficiency virus (HIV-1) retroviral type nucleocapsid protein NCp7.

  12. Governing processes for reactive nitrogen compounds in the European atmosphere

    NASA Astrophysics Data System (ADS)

    Hertel, O.; Skjøth, C. A.; Reis, S.; Bleeker, A.; Harrison, R. M.; Cape, J. N.; Fowler, D.; Skiba, U.; Simpson, D.; Jickells, T.; Kulmala, M.; Gyldenkærne, S.; Sørensen, L. L.; Erisman, J. W.; Sutton, M. A.

    2012-12-01

    Reactive nitrogen (Nr) compounds have different fates in the atmosphere due to differences in the governing processes of physical transport, deposition and chemical transformation. Nr compounds addressed here include reduced nitrogen (NHx: ammonia (NH3) and its reaction product ammonium (NH4+)), oxidized nitrogen (NOy: nitrogen monoxide (NO) + nitrogen dioxide (NO2) and their reaction products) as well as organic nitrogen compounds (organic N). Pollution abatement strategies need to take into account the differences in the governing processes of these compounds when assessing their impact on ecosystem services, biodiversity, human health and climate. NOx (NO + NO2) emitted from traffic affects human health in urban areas where the presence of buildings increases the residence time in streets. In urban areas this leads to enhanced exposure of the population to NOx concentrations. NOx emissions generally have little impact on nearby ecosystems because of the small dry deposition rates of NOx. These compounds need to be converted into nitric acid (HNO3) before removal through deposition is efficient. HNO3 sticks quickly to any surface and is thereby either dry deposited or incorporated into aerosols as nitrate (NO3-). In contrast to NOx compounds, NH3 has potentially high impacts on ecosystems near the main agricultural sources of NH3 because of its large ground-level concentrations along with large dry deposition rates. Aerosol phase NH4+ and NO3- contribute significantly to background PM2.5 and PM10 (mass of aerosols with an aerodynamic diameter of less than 2.5 and 10 μm, respectively) with an impact on radiation balance as well as potentially on human health. Little is known quantitatively and qualitatively about organic N in the atmosphere, other than that it contributes a significant fraction of wet-deposited N, and is present in both gaseous and particulate forms. Further studies are needed to characterise the sources, air chemistry and

  13. Reactivity of monocyclic aromatic compounds under hydrothermal conditions

    NASA Astrophysics Data System (ADS)

    McCollom, T. M.; Seewald, J. S.; Simoneit, B. R. T.

    2001-02-01

    Monocyclic aromatic compounds (MAC) represent a significant fraction of the total organic carbon in many geologic environments such as hydrothermal systems and petroleum reservoirs, yet the factors that control their abundance in these environments remain highly uncertain. In order to evaluate whether aqueous reactions involving MAC have a significant impact on their occurrence, laboratory experiments were conducted to observe the reactivity of several simple MAC under hydrothermal conditions that included the presence of mineral redox buffers. Aqueous solutions of individual MAC were heated at 300 to 330°C and 350 bar in flexible gold reaction vessels with titanium fittings. Toluene in aqueous solution was found to gradually decompose during heating to form primarily benzene plus CO 2, indicating the decomposition proceeded by an oxidative decarboxylation pathway. The rate of this reaction was enhanced by the presence of dissolved sulfur compounds and relatively oxidizing conditions, suggesting that intermediate oxidation state sulfur compounds (such as thiosulfate or polythionates) could play a role in promoting the reaction by facilitating the transfer of electrons among reactants. Benzoic acid decomposed rapidly to benzene plus CO 2, suggesting that formation of benzoic acid is the rate-limiting step in the overall conversion of toluene to benzene. Both benzene and phenol were found to be essentially unreactive. An assessment of the reaction products was performed to evaluate whether reactions among MAC attained metastable thermodynamic equilibrium. The results of this assessment, however, were equivocal, with some observations suggesting approach to thermodynamic equilibrium while other data indicate that criteria to demonstrate equilibrium were not met. The laboratory results demonstrate that aqueous reactions can play a role in controlling the abundance of aromatic compounds in geologic environments.

  14. Electronic property and reactivity of (hydroperoxo)metal compounds.

    PubMed

    Nishida, Y; Nishino, S

    2001-01-01

    DFT calculations were done for the (hydroperoxo)metal complexes with eta1-coordination mode, where metal ions are Fe(III), Al(III), Cu(II) and Zn(II). Results shows that 1) the electron density at the two oxygen atoms of the hydroperoxide ion is highly dependent on the angle O-O-H in M-OOH species and the difference in electron density between the two oxygen atoms reaches a maximum at the angle O-O-H = 180 degrees, 2) total electron density at the two oxygen atoms of the peroxide ion increases by approach of methane to the (hydroperoxo)metal species in the cases of Fe(III) and Cu(II); on the other hand, significant decrease of the electron density on peroxide oxygen atoms was observed for the cases of Al(III) and Zn(II) compounds. These findings suggest that the (hydroperoxo)metal species acts as an electrophile in the former cases (M = Fe(III), Cu(II)) and as a nucleophile for the latter two compounds (M = Zn(II), Al(III)). The electrophilicity observed for the Fe(III) and Cu(II) complexes is attributed to the presence of unoccupied- or half-filled d-orbitals interacting with the hydroperoxide ion. 3) Two oxygen atoms of the (hydroperoxo)-compounds of Fe(III) and Cu(II) complexes exhibit quite different reactivity toward the substrate, such as methane. When methane approaches the oxygen atom which is coordinated to a metal ion, a strong decrease of electron density at the methane carbon atom occurs with concomitant increase of electron density at the peroxide oxygen atoms inducing its heterolytic O-O cleavage. When methane approaches the terminal oxygen atom, an oxidative coupling reaction occurs between peroxide ion and methane; at first a nucleophilic attack by the terminal electron-rich oxygen atom occurs at the carbon atom to induce C-O bond formation, and a subsequent oxidative electron transfer proceeds from substrate to the metal-peroxide species yielding CH3-OOH, CH3OH, or other oxidized products. These results clearly demonstrate that the (hydroperoxo

  15. Reactive Nitrogen Compounds in the Troposphere: Observations, Transport, and Photochemistry

    NASA Astrophysics Data System (ADS)

    Luke, Winston Thomas

    Oxides of nitrogen critically control the photochemical production of ozone and account for approximately 1/3 of the total acid deposition in North America. This dissertation presents the results of three studies designed to enhance our knowledge of the distribution, transport, and photochemistry of reactive (or odd) nitrogen compounds in the troposphere. Concentrations of odd nitrogen were measured in both urban and rural air advected from the polluted east coast of North America to the western Atlantic ocean as part of the 1986 Western ATlantic Ocean eXperiment. On January 9, 1986, median (NOy) rose from 0.28 ppbv in the free troposphere (FT) to 1.38 ppbv in the marine boundary layer (MBL), and ratios of peroxyacetyl nitrate (PAN) to NOy were similar to those observed at a non-urban site in Colorado during autumn. The maximum gross flux of nitrogen through the FT and MBL between 31.5-44.1^ circN was estimated to be 25.6 kg N s ^{-1}. Reactive nitrogen compounds, carbon monoxide, and ozone were measured over the central United States in 1985 and 1986 from a twin-jet aircraft. Vertical profiles of reactive nitrogen compounds show dramatic perturbations due to the effects of violent convective activity. Measurements made in stable air dominated by high pressure contrast with those made near organized, isolated convective cells, which efficiently transport odd nitrogen to the upper troposphere. The layered lifting associated with episodes of cold frontal passage efficiently mixes both the upper and middle troposphere, however. Rapid injection of boundary layer air into the upper troposphere, where colder temperatures and higher wind velocities combine to extend both the lifetimes and range of influence of a variety of primary and secondary pollutants, will increase the rate of photochemical ozone production aloft and may thus exacerbate the greenhouse effect. Finally, the photolysis rate coefficients (j) of several alkyl nitrates (RONO_2) to NO_2 and the alkoxy

  16. Novel Scaffold FingerPrint (SFP): applications in scaffold hopping and scaffold-based selection of diverse compounds.

    PubMed

    Rabal, Obdulia; Amr, Fares Ibrahim; Oyarzabal, Julen

    2015-01-26

    A novel 2D Scaffold FingerPrint (SFP) for mining ring fragments is presented. The rings are described not only by their topology, shape, and pharmacophoric features (hydrogen-bond acceptors and donors, their relative locations, sp3 carbons, and chirality) but also by the position and nature of their growing vectors because they play a critical role from the drug discovery perspective. SFP can be used (i) to identify alternative chemotypes to a reference ring either in a visual mode or by running quantitative similarity searches and (ii) in chemotype-based diversity selections. Two retrospective case studies focused on melanin concentrating hormone 1-receptor antagonists (MCH-R1) and phosphodiesterase-5 inhibitors (PDE5) demonstrate the capability of this method for identifying novel structurally different and synthetically accessible chemotypes. Good enrichment factor (155 and 219) and recall values (46% and 73%) are found within the first 100 ranked hits (0.3% of screened database). Our 2D SFP descriptor outperforms well-validated current gold-standard 2D fingerprints (ECFP_6) and 3D approaches based on shape and electrostatic similarity. Scaffold-based selection of diverse compounds has a critical impact on corporate library design and compound acquisitions; thus, a novel strategy is introduced that uses diverse scaffold selections using this SFP descriptor combined with R-group selection at the different substitution sites. Both approaches are available as part of an interactive web-based application that requires minimal input and no computational knowledge by medicinal chemists. PMID:25558803

  17. Exploratory study of reactivity in organic compounds subjected to shock loading. [Diphenylhexadiyne

    SciTech Connect

    Dodson, B.W.

    1981-01-01

    An exploratory study of chemical reactions occurring in organic compounds under shock loading has been carried out. Early results on shock reactivity of the organic compounds acrylamide, adamantane, hexamethylenetetramine, naphthalene, and 1,6-diphenyl-2,4-hexadiyne have established two points: (1) organic reactions occur under shock loading; and (2) chemical structure strongly influences shock reactivity.

  18. Finger pain

    MedlinePlus

    Pain - finger ... Nearly everyone has had finger pain at some time. You may have: Tenderness Burning Stiffness Numbness Tingling Coldness Swelling Change in skin color Redness Many conditions, such ...

  19. Gas chromatograph-mass spectrometer (GC/MS) system for quantitative analysis of reactive chemical compounds

    DOEpatents

    Grindstaff, Quirinus G.

    1992-01-01

    Described is a new gas chromatograph-mass spectrometer (GC/MS) system and method for quantitative analysis of reactive chemical compounds. All components of such a GC/MS system external to the oven of the gas chromatograph are programmably temperature controlled to operate at a volatilization temperature specific to the compound(s) sought to be separated and measured.

  20. Reactive codoping of GaAlInP compound semiconductors

    DOEpatents

    Hanna, Mark Cooper; Reedy, Robert

    2008-02-12

    A GaAlInP compound semiconductor and a method of producing a GaAlInP compound semiconductor are provided. The apparatus and method comprises a GaAs crystal substrate in a metal organic vapor deposition reactor. Al, Ga, In vapors are prepared by thermally decomposing organometallic compounds. P vapors are prepared by thermally decomposing phospine gas, group II vapors are prepared by thermally decomposing an organometallic group IIA or IIB compound. Group VIB vapors are prepared by thermally decomposing a gaseous compound of group VIB. The Al, Ga, In, P, group II, and group VIB vapors grow a GaAlInP crystal doped with group IIA or IIB and group VIB elements on the substrate wherein the group IIA or IIB and a group VIB vapors produced a codoped GaAlInP compound semiconductor with a group IIA or IIB element serving as a p-type dopant having low group II atomic diffusion.

  1. PREDICTION OF CHEMICAL REACTIVITY PARAMETERS AND PHYSICAL PROPERTIES OF ORGANIC COMPOUNDS FROM MOLECULAR STRUCTURE USING SPARC

    EPA Science Inventory

    The computer program SPARC (SPARC Performs Automated Reasoning in Chemistry) has been under development for several years to estimate physical properties and chemical reactivity parameters of organic compounds strictly from molecular structure. SPARC uses computational algorithms...

  2. ESTIMATION OF PHYSICAL PROPERTIES AND CHEMICAL REACTIVITY PARAMETERS OF ORGANIC COMPOUNDS

    EPA Science Inventory

    The computer program SPARC (Sparc Performs Automated Reasoning in Chemistry)has been under development for several years to estimate physical properties and chemical reactivity parameters of organic compounds strictly from molecular structure. SPARC uses computational algorithms ...

  3. From carbanions to organometallic compounds: quantification of metal ion effects on nucleophilic reactivities.

    PubMed

    Corral-Bautista, Francisco; Klier, Lydia; Knochel, Paul; Mayr, Herbert

    2015-10-12

    The influence of the metal on the nucleophilic reactivities of indenyl metal compounds was quantitatively determined by kinetic investigations of their reactions with benzhydrylium ions (Ar2 CH(+) ) and structurally related quinone methides. With the correlation equation log k2 =sN (N+E), it can be derived that the ionic indenyl alkali compounds are 10(18) to 10(24) times more reactive (depending on the reference electrophile) than the corresponding indenyltrimethylsilane. PMID:25951612

  4. Estimating sources, sinks and fluxes of reactive atmospheric compounds within a forest canopy

    EPA Science Inventory

    While few dispute the significance of within-canopy sources or sinks of reactive gaseous and particulate compounds, their estimation continues to be the subject of active research and debate. Reactive species undergo turbulent dispersion within an inhomogeneous flow field, and ma...

  5. Characterization of the reactivities of volatile organic compounds using a master chemical mechanism.

    PubMed

    Derwent, R G; Jenkin, M E; Saunders, S M; Pilling, M J

    2001-05-01

    A comprehensive description of the ozone-forming potentials of 101 organic compounds has been constructed under North American urban "averaged conditions" using a detailed master chemical mechanism and a simple air parcel trajectory model. This chemical mechanism describes the reactions of 3603 chemical species taking part in more than 10,500 chemical reactions. An index value has been calculated for each organic compound, which describes the increment in ozone concentrations found downwind of an urban area following the emission of a fixed increment in the mass emission of each organic compound. These indices, termed photochemical ozone creation potentials (POCPs), have been expressed on a scale relative to ethylene (ethene) = 100, and, a reactivity scale has been generated for alkanes, alkenes, and oxygenated and halogenated organic compounds. A high degree of correlation (R2 = 0.9) was found between these POCP values and the most widely accepted urban reactivity scale. While the reactivities of most of the 86 organic compounds compared fell within a consistent range, significant discrepancies were found for only 5 compounds. Single-day or multiday conditions appear to be important in establishing quantitative reactivity scales for the less reactive organic compounds. PMID:11355457

  6. Diverse reactivity of borenium cations with >N-H compounds.

    PubMed

    Devillard, Marc; Mallet-Ladeira, Sonia; Bouhadir, Ghenwa; Bourissou, Didier

    2016-07-01

    The Ph2P-stabilized borenium reacts cleanly with PhNH2, NH3 and HNTf2 to give a variety of boron compounds, namely the amino-substituted borenium (substitution reaction at B), the neutral phosphine-borane , the mixed P/N-stabilized boronium and the dicationic boron species . Remote modulation of the Lewis acidity at boron has been studied by preparing the related iPr2P-stabilized borenium and reacting it with dihydrogen. PMID:27352236

  7. Reactivity of Various Compound Classes Towards the Folin-Ciocalteu Reagent

    NASA Astrophysics Data System (ADS)

    Walker, Richard B.; Everette, Jace D.; Bryant, Quinton M.; Green, Ashlee M.; Abbey, Yvonne A.; Wangila, Grant W.

    2010-04-01

    The Folin-Ciocalteu assay has been used for over 80 years for the detection and quantitation of phenols. A modification of it, called the Lowry assay, is used for the quantitation of proteins. It has been commonly reported that the Folin-Ciocalteu reagent, which is a complex mixture containing sodium molybdate and sodium tungstate, is reactive towards other antioxidants besides phenols. However, until now, no one has done experiments to test this hypothesis. In our study, we tested the reactivity of the reagent towards over 70 compounds. Compound classes included phenols, thiols, vitamins, amino acids, proteins, nucleotide bases, unsaturated fatty acids, carbohydrates, organic acids, inorganic ions, aldehydes and ketones. All phenols, proteins and thiols tested were reactive towards the reagent. Other compounds which showed reactivity included guanine, glyceraldehyde, dihydroxyacetone, tyrosine, tryptophan, cysteine, ascorbic acid, Trolox, retinoic acid, pyridoxine, Fe+2, Mn+2, I- and SO3-2. In summary, our study showed that the Folin-Ciocalteu reagent is significantly reactive towards other compounds besides phenols. Therefore, it should be seen as a measure of total antioxidant capacity rather than phenolic content. It would be useful as a general antioxidant assay for measuring antioxidant capacities of compounds of biomedical interest.

  8. Palmate-like pentafoliata1 encodes a novel Cys(2)His(2) zinc finger transcription factor essential for compound leaf morphogenesis in Medicago truncatula

    PubMed Central

    2010-01-01

    As the primary site for photosynthetic carbon fixation and the interface between plants and the environment, plant leaves play a key role in plant growth, biomass production and survival, and global carbon and oxygen cycles. Leaves can be simple with a single blade or compound with multiple units of blades known as leaflets. In a palmate-type compound leaf, leaflets are clustered at the tip of the leaf. In a pinnate-type compound leaf, on the other hand, leaflets are placed on a rachis in distance from each other. Higher orders of complexities such as bipinnate compound leaves of the “sensitive” plant, Mimosa pudica, also occur in nature. However, how different leaf morphologies are determined is still poorly understood. Medicago truncatula is a model legume closely related to alfalfa and soybean with trifoliate compound leaves. Recently, we have shown that Palmate-like Pentafoliata1 (PALM1) encodes a putative Cys(2) His(2) zinc finger transcription factor essential for compound leaf morphogenesis in M. truncatula. Here, we present our phylogenetic relationship analysis of PALM1 homologs from different species and demonstrate that PALM1 has transcriptional activity in the transactivation assay in yeast. PMID:20724826

  9. Incremental Reactivity Effects of Anthropogenic and Biogenic Volatile Organic Compounds on Secondary Organic Aerosol Formation

    NASA Astrophysics Data System (ADS)

    Kacarab, M.; Li, L.; Carter, W. P. L.; Cocker, D. R., III

    2015-12-01

    Two surrogate reactive organic gas (ROG) mixtures were developed to create a controlled reactivity environment simulating different urban atmospheres with varying levels of anthropogenic (e.g. Los Angeles reactivity) and biogenic (e.g. Atlanta reactivity) influences. Traditional chamber experiments focus on the oxidation of one or two volatile organic compound (VOC) precursors, allowing the reactivity of the system to be dictated by those compounds. Surrogate ROG mixtures control the overall reactivity of the system, allowing for the incremental aerosol formation from an added VOC to be observed. The surrogate ROG mixtures were developed based on that used to determine maximum incremental reactivity (MIR) scales for O3 formation from VOC precursors in a Los Angeles smog environment. Environmental chamber experiments were designed to highlight the incremental aerosol formation in the simulated environment due to the addition of an added anthropogenic (aromatic) or biogenic (terpene) VOC. All experiments were conducted in the UC Riverside/CE-CERT dual 90m3 environmental chambers. It was found that the aerosol precursors behaved differently under the two altered reactivity conditions, with more incremental aerosol being formed in the anthropogenic ROG system than in the biogenic ROG system. Further, the biogenic reactivity condition inhibited the oxidation of added anthropogenic aerosol precursors, such as m-xylene. Data will be presented on aerosol properties (density, volatility, hygroscopicity) and bulk chemical composition in the gas and particle phases (from a SYFT Technologies selected ion flow tube mass spectrometer, SIFT-MS, and Aerodyne high resolution time of flight aerosol mass spectrometer, HR-ToF-AMS, respectively) comparing the two controlled reactivity systems and single precursor VOC/NOx studies. Incremental aerosol yield data at different controlled reactivities provide a novel and valuable insight in the attempt to extrapolate environmental chamber

  10. Predicting the Reactivity of Nitrile-Carrying Compounds with Cysteine: A Combined Computational and Experimental Study

    PubMed Central

    2014-01-01

    Here, we report on a mechanistic investigation based on DFT calculations and kinetic measures aimed at determining the energetics related to the cysteine nucleophilic attack on nitrile-carrying compounds. Activation energies were found to correlate well with experimental kinetic measures of reactivity with cysteine in phosphate buffer. The agreement between computations and experiments points to this DFT-based approach as a tool for predicting both nitrile reactivity toward cysteines and the toxicity of nitriles as electrophile agents. PMID:24900869

  11. Mallet finger - aftercare

    MedlinePlus

    Baseball finger - aftercare; Drop finger - aftercare; Avulsion fracture - mallet finger - aftercare ... Mallet finger occurs when you cannot straighten your finger: when you try to straighten it, the tip of your ...

  12. An Arabidopsis Zinc Finger Protein Increases Abiotic Stress Tolerance by Regulating Sodium and Potassium Homeostasis, Reactive Oxygen Species Scavenging and Osmotic Potential.

    PubMed

    Zang, Dandan; Li, Hongyan; Xu, Hongyun; Zhang, Wenhui; Zhang, Yiming; Shi, Xinxin; Wang, Yucheng

    2016-01-01

    Plant zinc finger proteins (ZFPs) comprise a large protein family and they are mainly involved in abiotic stress tolerance. Although Arabidopsis RING/FYVE/PHD ZFP At5g62460 (AtRZFP) is found to bind to zinc, whether it is involved in abiotic stress tolerance is still unknown. In the present study, we characterized the roles of AtRZFP in response to abiotic stresses. The expression of AtRZFP was induced significantly by salt and osmotic stress. AtRZFP positively mediates tolerance to salt and osmotic stress. Additionally, compared with wild-type Arabidopsis plants, plants overexpressing AtRZFP showed reduced reactive oxygen species (ROSs) accumulation, enhanced superoxide dismutase and peroxidase activity, increased soluble sugars and proline contents, reduced K(+) loss, decreased Na(+) accumulation, stomatal aperture and the water loss rate. Conversely, AtRZFP knockout plants displayed the opposite physiological changes when exposed to salt or osmotic stress conditions. These data suggested that AtRZFP enhances salt and osmotic tolerance through a series of physiological processes, including enhanced ROSs scavenging, maintaining Na(+) and K(+) homeostasis, controlling the stomatal aperture to reduce the water loss rate, and accumulating soluble sugars and proline to adjust the osmotic potential. PMID:27605931

  13. An Arabidopsis Zinc Finger Protein Increases Abiotic Stress Tolerance by Regulating Sodium and Potassium Homeostasis, Reactive Oxygen Species Scavenging and Osmotic Potential

    PubMed Central

    Zang, Dandan; Li, Hongyan; Xu, Hongyun; Zhang, Wenhui; Zhang, Yiming; Shi, Xinxin; Wang, Yucheng

    2016-01-01

    Plant zinc finger proteins (ZFPs) comprise a large protein family and they are mainly involved in abiotic stress tolerance. Although Arabidopsis RING/FYVE/PHD ZFP At5g62460 (AtRZFP) is found to bind to zinc, whether it is involved in abiotic stress tolerance is still unknown. In the present study, we characterized the roles of AtRZFP in response to abiotic stresses. The expression of AtRZFP was induced significantly by salt and osmotic stress. AtRZFP positively mediates tolerance to salt and osmotic stress. Additionally, compared with wild-type Arabidopsis plants, plants overexpressing AtRZFP showed reduced reactive oxygen species (ROSs) accumulation, enhanced superoxide dismutase and peroxidase activity, increased soluble sugars and proline contents, reduced K+ loss, decreased Na+ accumulation, stomatal aperture and the water loss rate. Conversely, AtRZFP knockout plants displayed the opposite physiological changes when exposed to salt or osmotic stress conditions. These data suggested that AtRZFP enhances salt and osmotic tolerance through a series of physiological processes, including enhanced ROSs scavenging, maintaining Na+ and K+ homeostasis, controlling the stomatal aperture to reduce the water loss rate, and accumulating soluble sugars and proline to adjust the osmotic potential. PMID:27605931

  14. Synthesis, characterization, and reactivity of sulfided hexanuclear molybdenum cluster compounds

    SciTech Connect

    Spink, D.

    1990-09-21

    Hexanuclear molybdenum clusters with mixed chloride and sulfide bridging ligands were prepared by reacting {alpha}-MoCl{sub 2} with sodium hydrosulfide in the presence of sodium butoxide. The resulting species, Mo{sub 6}Cl{sub (8-x)}S{sub x}{center dot}npy(x {congruent} 3.6, n {congruent} 4, py = pyridine), was pyrophoric and insoluble. The mixed sulfide chloride cluster species Mo{sub 6}S{sub 4}Cl{sub 4}{center dot}6OPEt{sub 3} and Mo{sub 6}S{sub {approximately}5}Cl{sub {approximately}3}{center dot}6PEt{sub 3} and Mo{sub 6}S{sub 8}{center dot}6PEt{sub 3} were isolated and characterized. Phosphorus-31 nuclear magnetic resonance, electron paramagnetic resonance, and UV/visible spectra were obtained for each fraction. The completely sulfided cluster, Mo{sub 6}S{sub 8}{center dot}6PEt{sub 3}, was prepared similarly and used in various experiments as a possible precursor to Chevrel phase materials of the type Mo{sub 6}S{sub 8}or M{sub n}Mo{sub 6}S{sub 8}. With the goal of removing all of the triethylphosphine ligands, Mo{sub 6}S{sub 8}{center dot}6PEt{sub 3} was reacted with the transition metal carbonyls molybdenum hexacarbonyl and dicobalt octacarbonyl. Reaction on the molecular sulfide cluster with copper(I) chloride in toluene gave a completely insoluble product. The reaction of Mo{sub 6}S{sub 8}{center dot}6PEt{sub 3} with propylene sulfide gave a product whose infrared spectra showed only very weak peaks associated with coordinated triethylphosphine. The elemental analysis of this product fit the formula Mo{sub 6}S{sub 8}{center dot}5SPEt{sub 3}. Reactivity of the outer ligands of the Mo{sub 6}S{sub 8}{center dot}npy and Mo{sub 6}S{sub 8}{center dot}(6{minus}x)PrNH{sub x} clusters were investigated. Crystalline Mo{sub 6}S{sub 8}{center dot}6THT was recovered from the reaction of the n-propylamine derivative with THT. A crystal structure determination was done. 87 refs., 12 fig., 15 tabs.

  15. Finger Stiffness.

    PubMed

    Oosterhoff, Thijs C H; Nota, Sjoerd P F T; Ring, David

    2015-06-01

    Background Finger stiffness varies substantially in patients with hand and upper extremity illness and can be notably more than expected for a given pathophysiology. In prior studies, pain intensity and magnitude of disability consistently correlate with coping strategies such as catastrophic thinking and kinesiophobia, which can be characterized as overprotectiveness. In this retrospective study we address the primary research question whether patients with finger stiffness are more often overprotective when the primary pathology is outside the hand (e.g. distal radius fracture) than when it is located within the hand. Methods In an orthopaedic hand surgery department 160 patients diagnosed with more finger stiffness than expected for a given pathophysiology or time point of recovery between December 2006 and September 2012 were analyzed to compare the proportion of patients characterized as overprotective for differences by site of pathology: (1) inside the hand, (2) outside the hand, and (3) psychiatric etiology (e.g. clenched fist). Results Among 160 subjects with more finger stiffness than expected, 132 (82 %) were characterized as overprotective including 88 of 108 (81 %) with pathology in the hand, 39 of 44 (89 %) with pathology outside the hand, and 5 of 8 (63 %) with psychiatric etiology. These differences were not significant. Conclusions Overprotectiveness is common in patients with more finger stiffness than expected regardless the site and type of primary pathology. It seems worthwhile to recognize and treat maladaptive coping strategies early during recovery to limit impairment, symptoms, and disability. PMID:26078497

  16. CRISPR-Cas9-based target validation for p53-reactivating model compounds

    PubMed Central

    Wanzel, Michael; Vischedyk, Jonas B; Gittler, Miriam P; Gremke, Niklas; Seiz, Julia R; Hefter, Mirjam; Noack, Magdalena; Savai, Rajkumar; Mernberger, Marco; Charles, Joël P; Schneikert, Jean; Bretz, Anne Catherine; Nist, Andrea; Stiewe, Thorsten

    2015-01-01

    Inactivation of the p53 tumor suppressor by Mdm2 is one of the most frequent events in cancer, so compounds targeting the p53-Mdm2 interaction are promising for cancer therapy. Mechanisms conferring resistance to p53-reactivating compounds are largely unknown. Here we show using CRISPR-Cas9–based target validation in lung and colorectal cancer that the activity of nutlin, which blocks the p53-binding pocket of Mdm2, strictly depends on functional p53. In contrast, sensitivity to the drug RITA, which binds the Mdm2-interacting N terminus of p53, correlates with induction of DNA damage. Cells with primary or acquired RITA resistance display cross-resistance to DNA crosslinking compounds such as cisplatin and show increased DNA cross-link repair. Inhibition of FancD2 by RNA interference or pharmacological mTOR inhibitors restores RITA sensitivity. The therapeutic response to p53-reactivating compounds is therefore limited by compound-specific resistance mechanisms that can be resolved by CRISPR-Cas9-based target validation and should be considered when allocating patients to p53-reactivating treatments. PMID:26595461

  17. Estimating sources, sinks and fluxes of reactive atmospheric compounds within a forest canopy

    NASA Astrophysics Data System (ADS)

    Ghannam, K.; Duman, T.; Walker, J. T.; Bash, J. O.; Huang, C. W.; Khlystov, A.; Katul, G. G.

    2015-12-01

    While few dispute the significance of within-canopy sources or sinks of reactive gaseous and particulate compounds, their estimation continues to be the subject of active research and debate. Reactive species undergo turbulent dispersion within an inhomogeneous flow field, and may be subjected to chemical, biological and/or physical deposition, emissions or transformations on leaves, woody elements, and the forest floor. This system involves chemical reactions and biological processes with multiple time scales and represents the terrestrial ecosystem's exposure to nutrient and acid deposition and atmospheric oxidants. The quantification of these processes is a first step in better understanding the ecological impact of air pollution and feedback to atmospheric composition. Hence, it follows that direct measurements of sources or sinks is difficult to conduct in the presence of all these processes. However, mean scalar concentration profiles measured within the canopy can be used to infer the profile distribution of effective sinks and sources if the flow field is known. This is commonly referred to as the 'inverse problem'. In-canopy and above-canopy multi-level concentration measurements of reactive nitrogen compounds (ammonia, nitric acid, nitrous acid), as well as other compounds that are highly reactive to ammonia and its secondary products (hydrochloric acid and sulfur dioxide), are presented within a deciduous second-growth 180 year old oak-hickory forest situated within the Southeastern U.S. Two different approaches are used to solve for the source-sink distribution from the measured mean scalar concentration profiles: (1) an Eulerian high-order closure model that solves the scalar flux budget equation and (2) a new Lagrangian stochastic model that estimates the dispersion matrix. As each of these methods is subject to different assumptions, the combination of the two can be used to constrain the solution to the inverse problem and permit inference on the

  18. Finger Multiplication

    ERIC Educational Resources Information Center

    Holmes, Bill

    2010-01-01

    The author has been prompted to write this article about finger multiplication for a number of reasons. Firstly there are a number of related articles in past issues of "Mathematics Teaching" ("MT") which have connections to this algorithm. Secondly, very few of his primary teaching students and professional colleagues appear to be aware of the…

  19. Porous desulfurization sorbent pellets containing a reactive metal oxide and an inert zirconium compound

    SciTech Connect

    Gardner, Todd H.; Gasper-Galvin, Lee D.

    1996-12-01

    Sorbent pellets for removing hydrogen sulfide from coal gas are prepared by combining a reactive oxide, in particular zinc oxide, with a zirconium compound such as an oxide, silicate, or aluminate of zirconium, and an inorganic binder and pelletizing and calcining the mixture. Alternately, the zinc oxide may be replaced by copper oxide or a combination of copper, molybdenum, and manganese oxides. The pellet components may be mixed in dry form, moistened to produce a paste, and converted to pellets by forming an aqueous slurry of the components and spray drying the slurry, or the reactive oxide may be formed on existing zirconium-containing catalyst-carrier pellets by infusing a solution of a salt of the active metal onto the existing pellets and firing at a high temperature to produce the oxide. Pellets made according to this invention show a high reactivity with hydrogen sulfide and durability such as to be useful over repeated cycles of sorption and regeneration.

  20. The synthesis, structure and reactivity of an imine-stabilized carboranylphosphorus(i) compound.

    PubMed

    Chan, Tek Long; Xie, Zuowei

    2016-06-01

    A new imine-stabilized carboranyl-phosphinidene has been synthesized and structurally characterized. DFT studies suggest that the imine moiety provides an electron pair to stabilize carboranyl-phosphinidene. On the other hand, the sterically demanding carboranyl ligand can prevent the dimerization, facilitating the formation of monomeric phosphinidene. These observations are supported by the reactivity studies. Such a monovalent phosphorous(i) compound can undergo reactions with Cu(OAc)2, S, Se, (TMS)CHN2 and HCl to give various phosphorus(iii) species. All compounds are fully characterized by NMR spectroscopy, elemental analyses as well as single-crystal X-ray analyses. PMID:27180610

  1. Reactive DESI-MS imaging of biological tissues with dicationic ion-pairing compounds.

    PubMed

    Lostun, Dragos; Perez, Consuelo J; Licence, Peter; Barrett, David A; Ifa, Demian R

    2015-03-17

    This work illustrates reactive desorption electrospray ionization mass spectrometry (DESI-MS) with a stable dication on biological tissues. Rat brain and zebra fish tissues were investigated with reactive DESI-MS in which the dictation forms a stable bond with biological tissue fatty acids and lipids. Tandem mass spectrometry (MS/MS) was used to characterize the dication (DC9) and to identify linked lipid-dication compounds formed. The fragment m/z 85 common to both DC9 fragmentation and DC9-lipid fragmentation was used to confirm that DC9 is indeed bonded with the lipids. Lipid signals in the range of m/z 250-350 and phosphoethanolamines (PE) m/z 700-800 observed in negative ion mode were also detected in positive ion mode with reactive DESI-MS with enhanced signal intensity. Reactive DESI-MS imaging in positive ion mode of rat brain and zebra fish tissues allowed enhanced detection of compounds commonly observed in the negative ion mode. PMID:25710577

  2. Reactivity of recently deposited organic matter: Degradation of lipid compounds near the sediment-water interface

    NASA Astrophysics Data System (ADS)

    Canuel, Elizabeth A.; Martens, Christopher S.

    1996-05-01

    The usefulness of biomarker compounds buried in marine sediments depends upon a quantita tive understanding of the effects of early diagenesis on their distribution. To address this, a new experimental approach was utilized to determine rates of degradation in a coastal sediment. Rates of degradation for solvent-extractable lipid components were quantified in four sediment horizons composed of newly accumulated organic matter (31-144 days since deposition). Sediment accumulation rate data derived from changes in the inventory of Be-7 ( t 1/2 = 53.3 days) were combined with concentration data for lipid biomarker compounds, enabling us to evaluate the reactivity of organic matter in the upper 8 cm of the rapidly accumulating sediments of Cape Lookout Bight, North Carolina, USA (CLB). Net rates of loss and rate constants were calculated for individual compounds belonging to three classes of lipids: fatty acids, sterols, and n-alkanes. Individual components showed a range in reactivity, in some cases (fatty acids), attributable to differences in their biological sources. Rates and rate constants were consistently highest in the surficial sediments (0-2.5 cm), indicating that the reactivity of a given molecule(s) decreases over time, and beginning soon after deposition. Comparison with apparent rate constants ( k') calculated over longer timescales (one and ten years) shows that steady-state diagenetic models underestimate rates of degradation at or near the sediment-water interface by an order of magnitude.

  3. Lignin model compounds as bio-based reactive diluents for liquid molding resins.

    PubMed

    Stanzione, Joseph F; Sadler, Joshua M; La Scala, John J; Wool, Richard P

    2012-07-01

    Lignin is a copious paper and pulping waste product that has the potential to yield valuable, low molecular weight, single aromatic chemicals when strategically depolymerized. The single aromatic lignin model compounds, vanillin, guaiacol, and eugenol, were methacrylated by esterification with methacrylic anhydride and a catalytic amount of 4-dimethylaminopyridine. Methacrylated guaiacol (MG) and methacrylated eugenol (ME) exhibited low viscosities at room temperature (MG: 17 cP and ME: 28 cP). When used as reactive diluents in vinyl ester resins, they produced resin viscosities higher than that of vinyl ester-styrene blends. The relative volatilities of MG (1.05 wt% loss in 18 h) and ME (0.96 wt% loss in 18 h) measured by means of thermogravimetric analysis (TGA) were considerably lower than that of styrene (93.7 wt% loss in 3 h) indicating the potential of these chemicals to be environmentally friendly reactive diluents. Bulk polymerization of MG and ME generated homopolymers with glass transition temperatures (T(g)s) of 92 and 103 °C, respectively. Blends of a standard vinyl ester resin with MG and ME (50 wt % reactive diluent) produced thermosets with T(g)s of 127 and 153 °C, respectively, which are comparable to vinyl ester-styrene resins, thus demonstrating the ability of MG and ME to completely replace styrene as reactive diluents in liquid molding resins without sacrificing cured-resin thermal performance. PMID:22517580

  4. Protection of neuronal cells against reactive oxygen species by carnosine and related compounds.

    PubMed

    Boldyrev, Alexander; Bulygina, Elena; Leinsoo, Toomas; Petrushanko, Irina; Tsubone, Shiori; Abe, Hiroki

    2004-01-01

    Carnosine and related compounds were compared in terms of their abilities to decrease the levels of reactive oxygen species (ROS) in suspensions of isolated neurons activated by N-methyl-D-aspartic acid (NMDA) using both stationary fluorescence measurements and flow cytometry. Carnosine was found to suppress the fluorescent signal induced by ROS production and decreased the proportion of highly fluorescent neurons, while histidine showed opposite effects. N-Acetylated derivatives of both carnosine and histidine demonstrated weak (statistically indistinguishable) suppressive effects on the ROS signal. N-Methylated derivatives of carnosine suppressed intracellular ROS generation to the same extent as carnosine. This rank of effectiveness is distinct from that previously obtained for the anti-radical ability of CRCs (anserine>carnosine>ophidine). These differences suggest that the similar ability of carnosine and its N-methylated derivatives to protect neuronal cells against the excitotoxic effect of NMDA is not solely related to the antioxidant properties of these compounds. PMID:14698913

  5. Finger Injuries and Disorders

    MedlinePlus

    You use your fingers and thumbs to do everything from grasping objects to playing musical instruments to typing. When there is something wrong ... the skin of your palm. It causes the fingers to stiffen and bend. Trigger finger - an irritation ...

  6. OH reactivity and concentrations of Biogenic Volatile Organic Compounds in a Mediterranean forest of downy oak trees

    NASA Astrophysics Data System (ADS)

    Zannoni, N.; Gros, V.; Lanza, M.; Sarda, R.; Bonsang, B.; Kalogridis, C.; Preunkert, S.; Legrand, M.; Jambert, C.; Boissard, C.; Lathiere, J.

    2015-08-01

    Understanding the processes between the biosphere and the atmosphere is challenged by the difficulty to determine with enough accuracy the composition of the atmosphere. Total OH reactivity, which is defined as the total loss of the hydroxyl radical in the atmosphere, has proved to be an excellent tool to identify indirectly the important reactive species in ambient air. High levels of unknown reactivity were found in several forests worldwide and were often higher than at urban sites. Such results demonstrated the importance of OH reactivity for characterizing two of the major unknowns currently present associated to forests: the set of primary emissions from the canopy to the atmosphere and biogenic compounds oxidation pathways. Previous studies also highlighted the need to quantify OH reactivity and missing OH reactivity at more forested sites. Our study presents results of a field experiment conducted during late spring 2014 at the forest site at the Observatoire de Haute Provence, OHP, France. The forest is mainly composed of downy oak trees, a deciduous tree species characteristic of the Mediterranean region. We deployed the Comparative Reactivity Method and a set of state-of-the-art techniques such as Proton Transfer Reaction-Mass Spectrometry and Gas Chromatography to measure the total OH reactivity, the concentration of volatile organic compounds and main atmospheric constituents at the site. We sampled the air masses at two heights: 2 m, i.e. inside the canopy, and 10 m, i.e. above the canopy, where the mean canopy height is 5 m. We found that the OH reactivity at the site mainly depended on the main primary biogenic species emitted by the forest, which was isoprene and to a lesser extent by its degradation products and long lived atmospheric compounds (up to 26 % during daytime). We determined that the daytime total measured reactivity equaled the calculated reactivity obtained from the concentrations of the compounds measured at the site. Hence, no

  7. Nucleophilic reactivity and electrocatalytic reduction of halogenated organic compounds by nickel o-phenylenedioxamidate complexes.

    PubMed

    Das, Siva Prasad; Ganguly, Rakesh; Li, Yongxin; Soo, Han Sen

    2016-09-14

    A growing number of halogenated organic compounds have been identified as hazardous pollutants. Although numerous advanced oxidative processes have been developed to degrade organohalide compounds, reductive and nucleophilic molecular approaches to dehalogenate organic compounds have rarely been reported. In this manuscript, we employ nickel(ii)-ate complexes bearing the o-phenylenebis(N-methyloxamide) (Me2opba) tetraanionic ligand as nucleophilic reagents that can react with alkyl halides (methyl up to the bulky isobutyl) by O-alkylation to give their respective imidate products. Four new nickel(ii) complexes have been characterized by X-ray crystallography, and the salient structural parameters and FT-IR vibrational bands (∼1655 cm(-1)) concur with their assignment as the imidate tautomeric form. To the best of our knowledge, this is the first report on the nucleophilic reactivity of Ni(II)(Me2opba) with halogenated organic compounds. The parent nickel(ii) Me2opba complex exhibits reversible electrochemical oxidation and reduction behavior. As a proof of concept, Ni(II)(Me2opba) and its alkylated congeners were utilized for the electrocatalytic reduction of chloroform, as a representative, simple polyhalogenated organic molecule that could arise from the oxidative treatment of organic compounds by chlorination. Modest turnover numbers of up to 6 were recorded, with dichloromethane identified as one of the possible products. Future efforts are directed towards bulkier -ate complexes that possess metal-centered instead of ligand-centered nucleophilic activity to create more effective electrocatalysts for the reduction of halogenated organic compounds. PMID:27506275

  8. Characteristics and reactivity of volatile organic compounds from non-coal emission sources in China

    NASA Astrophysics Data System (ADS)

    He, Qiusheng; Yan, Yulong; Li, Hongyan; Zhang, Yiqiang; Chen, Laiguo; Wang, Yuhang

    2015-08-01

    Volatile organic compounds (VOCs) were sampled from non-coal emission sources including fuel refueling, solvent use, industrial and commercial activities in China, and 62 target species were determined by gas chromatography-mass selective detector (GC-MSD). Based on the results, source profiles were developed and discussed from the aspects of composition characteristics, potential tracers, BTEX (benzene, toluene, ethylbenzene and xylene) diagnostic ratios and chemical reactivity. Compared with vehicle exhausts and liquid fuels, the major components in refueling emissions of liquefied petroleum gas (LPG), gasoline and diesel were alkenes and alkanes. Oppositely, aromatics were the most abundant group in emissions from auto-painting, book binding and plastic producing. Three groups contributed nearly equally in printing and commercial cooking emissions. Acetone in medical producing, chloroform and tetrachloroethylene in wet- and dry-cleaning, as well as TEX in plastic producing etc. were good tracers for the respective sources. BTEX ratios showed that some but not all VOCs sources could be distinguished by B/T, B/E and B/X ratios, while T/E, T/X and E/X ratios were not suitable as diagnostic indicators of different sources. The following reactivity analysis indicated that emissions from gasoline refueling, commercial cooking, auto painting and plastic producing had high atmospheric reactivity, and should be controlled emphatically to prevent ozone pollution, especially when there were large amounts of emissions for them.

  9. Emission of reactive terpene compounds from orange orchards and their removal by within-canopy processes

    NASA Astrophysics Data System (ADS)

    Ciccioli, Paolo; Brancaleoni, Enzo; Frattoni, Massimiliano; di Palo, Vincenzo; Valentini, Riccardo; Tirone, Giampiero; Seufert, Guenther; Bertin, Nadia; Hansen, Ute; Csiky, Olav; Lenz, Roman; Sharma, Meeta

    1999-04-01

    VOC emission from orange orchards was determined in the framework of two field campaigns aimed at assessing the contribution of vegetation emissions to tropospheric ozone formation in the Valencia Citrus belt. Branch emission from different varieties of Citrus sinensis and Citrus Clementi was dominated by β-caryophyllene during the summer period and by linalool during the blossoming season (April-May). Large emission of D-limonene from soil was also measured. Data collected with the enclosure technique were upscaled to determine canopy emission rates of terpene compounds. Values obtained were compared with fluxes measured by relaxed eddy accumulation. Substantial removal of β-caryophyllene and linalool was detected during transport from the canopy into the atmospheric boundary layer. While within-canopy removal of the sesquiterpene component was fully consistent with laboratory studies indicating the high reactivity of this compound with ozone, linalool losses were more difficult to explain. Although high canopy fluxes of acetone and acetaldehyde suggested linalool decomposition by gas-phase reactivity, removal by heterogeneous chemistry seems the more likely explanation for the observed losses.

  10. [Source profile and chemical reactivity of volatile organic compounds from vehicle exhaust].

    PubMed

    Qiao, Yue-Zhen; Wang, Hong-Li; Huang, Cheng; Chen, Chang-Hong; Su, Lei-Yan; Zhou, Min; Xu, Hua; Zhang, Gang-Feng; Chen, Yi-Ran; Li, Li; Chen, Ming-Hua; Huang, Hai-Ying

    2012-04-01

    Light-duty gasoline taxis (LDGT) and passenger cars (LDGV), heavy-duty diesel buses (HDDB) and trucks (HDDT), gasoline motorcycles (MC) and LPG scooters (LPGS), were selected for tailpipe volatile organic compounds (VOCs) samplings by using transient dynamometer and on road test combined with SUMMA canisters technology. The samples were tested by GC-MS to analyze the concentration and species composition of VOCs. The results indicate that light-duty gasoline automobiles have higher fractions of aromatic hydrocarbons, which account for 43.38%-44.45% of the total VOCs, the main aromatic hydrocarbons are toluene and xylenes. Heavy-duty diesel vehicles have higher fractions of alkanes, which constitute 46.86%-48.57% of the total VOCs, the main alkanes are propane, n-dodecane and n-undecane. In addition, oxy-organics account for 13.28%-15.01% of the VOCs, the main oxy-organics is acetone. The major compound from MC and LPGS exhaust is acetylene, it accounts for 39.75% and 76.67% of the total VOCs, respectively. VOCs exhaust from gasoline motorcycles and light-duty gasoline automobiles has a significantly higher chemical reactivity than those from heavy-duty diesel vehicles, which contribute 55% and 44% to the atmospheric chemical reactivity in Shanghai. The gasoline motorcycles and light-duty gasoline automobiles are the key pollution sources affecting city and region ambient oxidation, and the key active species of toluene, xylenes, propylene, and styrene make the greatest contribution. PMID:22720548

  11. Synthesis and reactivity of compounds containing ruthenium-carbon, -nitrogen, and -oxygen bonds

    SciTech Connect

    Hartwig, J.F.

    1990-12-01

    The products and mechanisms of the thermal reactions of several complexes of the general structure (PMe{sub 3}){sub 4}Ru(X)(Y) and (DMPM){sub 2}Ru(X)(Y) where X and Y are hydride, aryl, and benzyl groups, have been investigated. The mechanism of decomposition depends critically on the structure of the complex and the medium in which the thermolysis is carried out. The alkyl hydride complexes are do not react with alkane solvent, but undergo C-H activation processes with aromatic solvents by several different mechanisms. Thermolysis of (PMe{sub 3}){sub 4}Ru(Ph)(Me) or (PMe{sub 3}){sub 4}Ru(Ph){sub 2} leads to the ruthenium benzyne complex (PMe{sub 3}){sub 4}Ru({eta}{sup 2}-C{sub 6}H{sub 4}) (1) by a mechanism which involves reversible dissociation of phosphine. In many ways its chemistry is analogous to that of early rather than late organo transition metal complexes. The synthesis, structure, variable temperature NMR spectroscopy and reactivity of ruthenium complexes containing aryloxide or arylamide ligands are reported. These complexes undergo cleavage of a P-C bond in coordinated trimethylphosphine, insertion of CO and CO{sub 2} and hydrogenolysis. Mechanistic studies on these reactions are described. The generation of a series of reactive ruthenium complexes of the general formula (PMe{sub 3}){sub 4}Ru(R)(enolate) is reported. Most of these enolates have been shown to bind to the ruthenium center through the oxygen atom. Two of the enolate complexes 8 and 9 exist in equilibrium between the O- and C-bound forms. The reactions of these compounds are reported, including reactions to form oxygen-containing metallacycles. The structure and reactivity of these ruthenium metallacycles is reported, including their thermal chemistry and reactivity toward protic acids, electrophiles, carbon monoxide, hydrogen and trimethylsilane. 243 refs., 10 tabs.

  12. Synthesis and Reactivity of Oxo-Peroxo-Vanadium(V) Bipyridine Compounds

    PubMed Central

    Waidmann, Christopher R.; DiPasquale, Antonio G.

    2010-01-01

    The vanadium(IV) compound [VIVO(OH)(tBu2bpy)2]BF4 (VIVO(OH)) (tBu2bpy = 4,4′-di-tert-butylbipyridine) is slowly oxidized by O2 in ethereal solvents to give the oxo-peroxo compound [VVO(O2)(tBu2bpy)2]BF4 (VVO(O2)) in excellent yield. This and related compounds were fully characterized by NMR, IR, and optical spectroscopies, mass spectrometry, elemental analyses, and an X-ray crystal structure of the 4,4′-dimethylbipyridine analog, [VVO(O2)(Me2bpy)2]BF4. Monitoring the reaction of VIVO(OH) with O2 in THF/acetonitrile mixtures by 1H NMR and optical spectroscopies surprisingly shows that the initial product is the cis-dioxo compound [VV(O)2(tBu2bpy)2]BF4 (VVO2), which then converts to VVO(O2). Reaction of VIVO(OH) with 18O2 gives ca. 60% triply 18O labeled VVO(O2). The mechanism of formation of VVO(O2) is complex and may occur via initial reduction of O2 at vanadium(IV) to give a superoxo-vanadium(V) intermediate, autoxidation of the THF solvent, or both. That VVO2 is generated first appears to be due to the ability of VIVO(OH) to act as a hydrogen atom donor. For instance, VIVO(OH) reacts with VVO(O2) give VVO2. VVO(O2) is also slowly reduced to VIVO(OH) by the organic hydrogen atom donors hydroquinone and TEMPOH (2,2,6,6-tetramethylpiperidin-1-ol) as well as by triphenylphosphine. Notably, the peroxo complex VVO(O2) is much less reactive with these substrates than the analogous dioxo compound VVO2. PMID:20108930

  13. Noncontacting Finger Seal

    NASA Technical Reports Server (NTRS)

    Proctor, Margaret P. (Inventor); Steinetz, Bruce M. (Inventor)

    2004-01-01

    An annular finger seal is adapted to be interposed between a high pressure upstream region and a lower pressure downstream region to provide noncontact sealing along a rotatable member. The finger seal comprises axially juxtaposed downstream and upstream finger elements, each having integrally spaced fingers. The downstream fingers each have a lift pad, whereas the upstream fingers lack a pad. Each pad extends in a downstream direction. Each upstream finger is spaced from the rotating member a greater distance than each pad. Upon sufficient rotational speed of the rotating member, each pad is operative to lift and ride on a thin film of fluid intermediate the rotating member and the Pad.

  14. Exploring the Reactivity of Flavonoid Compounds with Metal-Associated Amyloid-β Species

    PubMed Central

    He, Xiaoming; Park, Hyun Min; Hyung, Suk-Joon; DeToma, Alaina S.; Kim, Cheal; Ruotolo, Brandon T.; Lim, Mi Hee

    2016-01-01

    Metal ions associated with amyloid-β (Aβ) peptides have been suggested to be involved in the development of Alzheimer’s disease (AD), but this remains unclear and controversial. Some attempts to rationally design or select small molecules with structural moieties for metal chelation and Aβ interaction (i.e., bifunctionality) have been made to gain a better understanding of the hypothesis. In order to contribute to these efforts, four synthetic flavonoid derivatives FL1 – FL4 were rationally selected according to the principles of bifunctionality and their abilities to chelate metal ions, interact with Aβ, inhibit metal-induced Aβ aggregation, scavenge radicals, and regulate the formation of reactive oxygen species (ROS) were studied using physical methods and biological assays. The compounds FL1 – FL3 were able to chelate metal ions, but showed limited solubility in aqueous buffered solutions. In the case of FL4, which was most compatible with aqueous conditions, its binding affinities for Cu2+ and Zn2+ (nM and μM, respectively) were obtained through solution speciation studies. The direct interaction between FL4 and Aβ monomer was weak, which was monitored by NMR spectroscopy and mass spectrometry. Employing FL1 – FL4, no noticeable inhibitory effect on metal-mediated Aβ aggregation was observed. Among FL1 – FL4, FL3, having 3-OH, 4-oxo, and 4′-N(CH3)2 groups, exhibited similar antioxidant activity to the vitamin E analogue, Trolox, and ca. 60% reduction in the amount of hydrogen peroxide (H2O2) generated by Cu2+-Aβ in the presence of dioxygen (O2) and a reducing agent. Overall, the studies here suggest that although four flavonoid molecules were selected based on expected bifunctionality, their properties and metal-Aβ reactivity were varied depending on the structure differences, demonstrating that bifunctionality must be well tuned to afford desirable reactivity. PMID:22437427

  15. Senescing grass crops as regional sources of reactive volatile organic compounds

    NASA Astrophysics Data System (ADS)

    Karl, T.; Harren, F.; Warneke, C.; de Gouw, J.; Grayless, C.; Fall, R.

    2005-08-01

    Grass crop species, rice and sorghum, that are widely grown in the southeastern Texas region were analyzed for release of biogenic volatile organic compounds (VOCs) in simulated leaf-drying/senescence experiments. VOC release was measured by both online proton transfer reaction mass spectrometry (PTR-MS) and proton transfer ion trap mass spectrometry (PIT-MS) methods, and it was demonstrated that these two grass crops release a large variety of oxygenated VOCs upon drying under laboratory conditions primarily from leaves and not from stems. VOC release from paddy rice varieties was much greater than from sorghum, and major VOCs identified by gas chromatography PTR-MS included methanol, acetaldehyde, acetone, n-pentanal, methyl propanal, hexenol, hexanal, cis-3-hexenal, and trans-2-hexenal. The latter four VOCs, all C6 compounds known to be formed in wounded leaves, were the major volatiles released from drying rice leaves; smaller but substantial amounts of acetaldehyde were observed in all drying experiments. Online detection of VOCs using PIT-MS gave results comparable to those obtained with PTR-MS, and use of PIT-MS with collision-induced dissociation of trapped ions allowed unambiguous determination of the ratios of cis- and trans-hexenals during different phases of drying. As rice is one of the largest harvested crops on a global scale, it is conceivable that during rice senescence releases of biogenic VOCs, especially the reactive C6 wound VOCs, may contribute to an imbalance in regional atmospheric oxidant formation during peak summer/fall ozone formation periods. A county-by-county estimate of the integrated emissions of reactive biogenic VOCs from sorghum and rice production in Texas suggests that these releases are orders of magnitude lower than anthropogenic VOCs in urban areas but also that VOC emissions from rice in southeastern coastal Texas may need to be included in regional air quality assessments during periods of extensive harvesting.

  16. Fingering dynamics driven by a precipitation reaction: Nonlinear simulations

    NASA Astrophysics Data System (ADS)

    Shukla, Priyanka; De Wit, A.

    2016-02-01

    A fingering instability can develop at the interface between two fluids when the more mobile fluid is injected into the less-mobile one. For example, viscous fingering appears when a less viscous (i.e., more mobile) fluid displaces a more viscous (and hence less mobile) one in a porous medium. Fingering can also be due to a local change in mobility arising when a precipitation reaction locally decreases the permeability. We numerically analyze the properties of the related precipitation fingering patterns occurring when an A +B →C chemical reaction takes place, where A and B are reactants in solution and C is a solid product. We show that, similarly to reactive viscous fingering patterns, the precipitation fingering structures differ depending on whether A invades B or vice versa. This asymmetry can be related to underlying asymmetric concentration profiles developing when diffusion coefficients or initial concentrations of the reactants differ. In contrast to reactive viscous fingering, however, precipitation fingering patterns appear at shorter time scales than viscous fingers because the solid product C has a diffusivity tending to zero which destabilizes the displacement. Moreover, contrary to reactive viscous fingering, the system is more unstable with regard to precipitation fingering when the high-concentrated solution is injected into the low-concentrated one or when the faster diffusing reactant displaces the slower diffusing one.

  17. OH reactivity and concentrations of biogenic volatile organic compounds in a Mediterranean forest of downy oak trees

    NASA Astrophysics Data System (ADS)

    Zannoni, N.; Gros, V.; Lanza, M.; Sarda, R.; Bonsang, B.; Kalogridis, C.; Preunkert, S.; Legrand, M.; Jambert, C.; Boissard, C.; Lathiere, J.

    2016-02-01

    Total OH reactivity, defined as the total loss frequency of the hydroxyl radical in the atmosphere, has proved to be an excellent tool to identify the total loading of reactive species in ambient air. High levels of unknown reactivity were found in several forests worldwide and were often higher than at urban sites.Our study presents atmospheric mixing ratios of biogenic compounds and total OH reactivity measured during late spring 2014 at the forest of downy oak trees of the Observatoire de Haute Provence (OHP), France. Air masses were sampled at two heights: 2 m, i.e., inside the canopy, and 10 m, i.e., above the canopy, where the mean canopy height is 5 m.We found that the OH reactivity at the site mainly depended on the main primary biogenic species emitted by the forest, which was isoprene and to a lesser extent by its degradation products and long-lived atmospheric compounds (up to 26 % during daytime). During daytime, no significant missing OH reactivity was reported at the site, either inside or above the canopy. However, during two nights we determined a missing fraction of OH reactivity up to 50 %, possibly due to unmeasured oxidation products. We confirmed that no significant oxidation of the primary species occurred within the canopy; primary compounds emitted by the forest were fast transported to the atmosphere. Finally, the OH reactivity at this site was maximum 69 s-1, which is a high value for a forest characterized by a temperate climate. Observations in various and diverse forests in the Mediterranean region are therefore needed to better constrain the impact of reactive gases over this area.

  18. Reactive and recoverable sorbents for halogenated organic compound remediation in sediments

    NASA Astrophysics Data System (ADS)

    Werner, David; Taggalou, Villy; Kordulis, Christos; Dolfing, Jan; Karapanagioti, Hrissi K.

    2013-04-01

    Activated carbon (AC) has been proposed as a sediment amendment for aquatic systems polluted with hydrophobic organic compounds. AC acts as a strong binding agent that lowers the pollutant concentration and thus, its toxicity. A draw back of this in-situ remediation method is that although the pollutant will remain non-bioavailable for many years being sorbed into AC, it actually stays in the system. A reactive sorbent, a sorbent that would, at the same time, facilitate the degradation of the pollutant, would be better accepted by the public or the regulators than AC amendment. So far, catalysts supported on AC with zero valent iron and a reactive metal have been proposed for the dechlorination of chlorinated organic compounds. These reactive metals are usually expensive or toxic and thus, their addition to the environment is not desirable. In the present study, activated carbon modified with reduced iron(AC/Fe) is tested in batch systems in the presence of sediment and DDT sorbed on polyethylene sheets. The batch systems are equilibrated for different contact times. Then, the DDT remaining in the polyethylene sheets is quantified along with DDD produced due to the dechlorination of DDT. A small percentage of DDT is degraded to DDD in the systems containing the AC/Fe material. No degradation of DDT is observed in the control systems containing the pollutant and the sediment or the pollutant, the sediment and AC. Thus, the addition of AC/Fe to the sediment with the DDT is enough to cause the dechlorination of DDT. At the end of the experiments, a magnet rod is used to recover the AC/Fe material from the batches with the sediment. An average recovery of 83% is achieved. This is a high percentage suggesting that the material can be easily recovered. Some drawbacks of the material preparation method are identified after the composite material characterization. For example, the AC/Fe surface area is decreased with the material preparation compared to the initial surface

  19. Synthesis and reactivity of oxo-peroxo-vanadium(V) bipyridine compounds.

    PubMed

    Waidmann, Christopher R; DiPasquale, Antonio G; Mayer, James M

    2010-03-01

    The vanadium(IV) compound [V(IV)O(OH)((t)Bu(2)bpy)(2)]BF(4) (V(IV)O(OH)) ((t)Bu(2)bpy = 4,4'-di-tert-butylbipyridine) is slowly oxidized by O(2) in ethereal solvents to give the oxo-peroxo compound [V(V)O(O(2))((t)Bu(2)bpy)(2)]BF(4) (V(V)O(O(2))) in excellent yield. This and related compounds were fully characterized by NMR, IR, and optical spectroscopies; mass spectrometry; elemental analyses; and an X-ray crystal structure of the 4,4'-dimethylbipyridine analog, [V(V)O(O(2))(Me(2)bpy)(2)]BF(4). Monitoring the reaction of V(IV)O(OH) with O(2) in THF/acetonitrile mixtures by (1)H NMR and optical spectroscopies surprisingly shows that the initial product is the cis-dioxo compound [V(V)(O)(2)((t)Bu(2)bpy)(2)]BF(4) (V(V)O(2)), which then converts to V(V)O(O(2)). Reaction of V(IV)O(OH) with (18)O(2) gives ca. 60% triply (18)O labeled V(V)O(O(2)). The mechanism of formation of V(V)O(O(2)) is complex and may occur via initial reduction of O(2) at vanadium(IV) to give a superoxo-vanadium(V) intermediate, autoxidation of the THF solvent, or both. That V(V)O(2) is generated first appears to be due to the ability of V(IV)O(OH) to act as a hydrogen atom donor. For instance, V(IV)O(OH) reacts with V(V)O(O(2)) to give V(V)O(2). V(V)O(O(2)) is also slowly reduced to V(IV)O(OH) by the organic hydrogen atom donors hydroquinone and TEMPOH (2,2,6,6-tetramethylpiperidin-1-ol) as well as by triphenylphosphine. Notably, the peroxo complex V(V)O(O(2)) is much less reactive with these substrates than the analogous dioxo compound V(V)O(2). PMID:20108930

  20. Hand and Finger Exercises

    MedlinePlus

    Hand and Finger Exercises  Place your palm flat on a table. Raise and lower your fingers one ... times for ____ seconds.  Pick up objects with your hand. Start out with larger objects. Repeat ____ times for ____ ...

  1. New insight into the photophysics and reactivity of trigonal and tetrahedral arylboron compounds.

    PubMed

    Santos, Willy G; Pina, João; Burrows, Douglas H; Forbes, Malcolm D E; Cardoso, Daniel R

    The photophysics and reactivity of two tetraphenylborate salts and triphenylborane have been studied using ultrafast transient absorption, steady-state fluorescence, electron paramagnetic resonance with spin trapping, and DFT calculations. The singlet excited state of tetraarylborates exhibit extended π-orbital coupling between two adjacent aryl groups. The maximum fluorescence band, as well as the transient absorption bands centered at 560 nm (τ = 1.05 ns) and 680 nm (τ = 4.35 ns) are influenced by solvent viscosity and polarity, indicative of a twisted intramolecular charge transfer (TICT) state. Orbital contour plots of the HOMO and LUMO orbitals of the tetraarylboron compounds support the existence of electron delocalization between two aryl groups in the LUMO. This TICT-state and aryl-aryl electron extension is not observed for the trigonal arylboron compound, in which excited π-orbital coupling only occurs between the boron atom and one aryl group, which restricts the twist motion of the aryl-boron bond. The excited triplet state is deactivated primarily through aryl-boron bond cleavage, yielding aryl and diphenylboryl radicals. In the presence of oxygen, this photochemistry results in phenoxyl and diphenylboroxyl radicals, as confirmed by EPR spectroscopy of spin trapped radical adducts. The TICT transition and radical generation is not expected for BoDIPY molecules where the rotational vibration of the B-aryl bond is rigid, restricting changes in the geometric structure. In this sense, this work contributes to the development of new BoDIPY derivatives where the TICT transition may be observed for aryl ligands with free rotational vibrations in the BoDIPY structure. PMID:27529675

  2. Flux measurements of reactive nitrogen compounds using a chemiluminescence analyser with different converter types

    NASA Astrophysics Data System (ADS)

    Ammann, Christof; Wolff, Veronika

    2015-04-01

    The availability of reactive nitrogen (Nr) is a key limiting factors for the productivity and the competition success of individual species. On the other hand, certain nitrogenous compounds can also be emitted from natural or managed ecosystems. Thus the quantification of the Nr exchange can be essential for the interpretation of ecosystem behavior. For the observation of Nr dry deposition and emission the eddy covariance (EC) method is preferable since it does not modify the environmental conditions of the ecosystem, is less prone to wall effects than chamber methods, and is less affected by gas phase chemical reactions than gradient methods. Since the various Nr compounds can undergo fast chemical reactions and have differing chemical and physical characteristics, a variety of detection techniques is usually necessary that often cannot meet the fast response requirements of the EC technique. Here we show applications of a fast response 2-channel NO analyzer suitable for EC measurements. In combination with different inlet converters (photolytic converter, gold catalyst converter, and high-temperature steel converter), the system could alternatively be used for flux measurements of NO2, NOy, and total Nr. The quantification of By combining the 2-channel analyzer with the NOy and total Nr converter simultaneously, the NH3 flux could be determined from the difference between the two channels. Concentration and flux measurements of the system were verified by inter-comparison with other methods. Potential problems include the damping of high-frequency fluctuations in the inlet system. It is therefore important to place the converter close to the sampling inlet and to quantify and correct the damping effects. Moreover, like most other flux measurement techniques, the system is susceptible to non-stationary trace gas concentrations that often occur near pollution sources.

  3. Induction of caspase 8 and reactive oxygen species by ruthenium-derived anticancer compounds with improved water solubility and cytotoxicity.

    PubMed

    Vidimar, Vania; Meng, Xiangjun; Klajner, Marcelina; Licona, Cynthia; Fetzer, Ludivine; Harlepp, Sébastien; Hébraud, Pascal; Sidhoum, Marjorie; Sirlin, Claude; Loeffler, Jean-Philippe; Mellitzer, Georg; Sava, Gianni; Pfeffer, Michel; Gaiddon, Christian

    2012-12-01

    Organometallic compounds which contain metals, such as ruthenium or gold, have been investigated as a replacement for platinum-derived anticancer drugs. They often show good antitumor effects, but the identification of their precise mode of action or their pharmacological optimization is still challenging. We have previously described a class of ruthenium(II) compounds with interesting anticancer properties. In comparison to cisplatin, these molecules have lower side effects, a reduced ability to interact with DNA, and they induce cell death in absence of p53 through CHOP/DDIT3. We have now optimized these molecules by improving their cytotoxicity and their water solubility. In this article, we demonstrate that by changing the ligands around the ruthenium we modify the ability of the compounds to interact with DNA. We show that these optimized molecules reduce tumor growth in different mouse models and retain their ability to induce CHOP/DDIT3. However, they are more potent inducers of cancer cell death and trigger the production of reactive oxygen species and the activation of caspase 8. More importantly, we show that blocking reactive oxygen species production or caspase 8 activity reduces significantly the activity of the compounds. Altogether our data suggest that water-soluble ruthenium(II)-derived compounds represent an interesting class of molecules that, depending on their structures, can target several pro-apoptotic signaling pathways leading to reactive oxygen species production and caspase 8 activation. PMID:22964219

  4. Estimation of Physical Properties and Chemical Reactivity Parameters of Organic Compounds for Environmental Modeling by SPARC

    EPA Science Inventory

    Mathematical models for predicting the transport and fate of pollutants in the environment require reactivity parameter values that is value of the physical and chemical constants that govern reactivity. Although empirical structure activity relationships have been developed th...

  5. Anthropogenic Emissions of Highly Reactive Volatile Organic Compounds (HRVOCs) Inferred from Oversampling of OMI HCHO Columns

    NASA Technical Reports Server (NTRS)

    Zhu, Lei; Jacob, Daniel; Mickley, Loretta; Marais, Eloise; Zhang, Aoxing; Cohan, Daniel; Yoshida, Yasuko; Duncan, Bryan; Abad, Gonzalo Gonzalez; Chance, Kelly; DeSmedt, Isabelle

    2014-01-01

    Satellite observations of formaldehyde (HCHO) columns provide top-down constraints on emissions of highly reactive volatile organic compounds (HRVOCs). This approach has been used previously to constrain emissions of isoprene from vegetation, but application to US anthropogenic emissions has been stymied by lack of a discernable HCHO signal. Here we show that oversampling of HCHO data from the Ozone Monitoring Instrument (OMI) for 2005 - 2008 enables quantitative detection of urban and industrial plumes in eastern Texas including Houston, Port Arthur, and Dallas-Fort Worth. By spatially integrating the individual urban-industrial HCHO plumes observed by OMI we can constrain the corresponding HCHO-weighted HRVOC emissions. Application to the Houston plume indicates a HCHO source of 260 plus or minus 110 kmol h-1 and implies a factor of 5.5 plus or minus 2.4 underestimate of anthropogenic HRVOC emissions in the US Environmental Protection Agency inventory. With this approach we are able to monitor the trend in HRVOC emissions over the US, in particular from the oil-gas industry, over the past decade.

  6. Lung function and bronchial reactivity in asthmatics during exposure to volatile organic compounds

    SciTech Connect

    Harving, H.; Dahl, R.; Molhave, L. )

    1991-04-01

    The purpose of the present study was to investigate whether vapors of organic solvents at low concentrations could exert an adverse effect in the lower airways. Under controlled conditions in a climate chamber, 11 persons with bronchial hyperreactivity to histamine and bronchial asthma were exposed for 90 min to a mixture of organic solvents at levels of zero, 2.5, and 25 mg/m3. During exposure to 25 mg/m3 a decrease in FEV1 to 90.7% of baseline value was measured. This was significantly different from the initial value (p less than 0.05), but not significantly different from the value found after sham exposure (FEV1, 97.4% of initial value). The decline in FEV1 during exposure to 25 mg/m3 was most pronounced in persons with high bronchial sensitivity. No changes were found in histamine reactivity after exposure, and no late reactions were registered. Ratings of discomfort showed different individual patterns ranging from no response to reactions towards both of the concentrations. The ratings indicated development of tolerance during exposure. Volatile organic compounds in concentrations found in both the work and the home environments may influence lung function and are probably of importance as bronchial irritants.

  7. Effect of reactive core mat application on bioavailability of hydrophobic organic compounds

    PubMed Central

    Meric, Dogus; Barbuto, Sara M.; Alshawabkeh, Akram N.; Shine, James P.; Sheahan, Thomas C.

    2014-01-01

    Sediment remediation techniques to limit the bioavailability of contaminants are of special interest due to related acute or chronic toxicities associated with sediment contaminants. Bioavailability in aquatic sediments can be particularly problematic due to their accessibility to food chain biota, and interactions with surface and ground water. The effect of a reactive core mat (RCM) containing organoclay on the bioavailability of hydrophobic organic compounds (HOCs) (i.e., PCBs and naphthalene) was studied using oligochaete worms (Lumbriculus variegatus). Sediment sampled from the Neponset River (Milton, MA) with 10 ppm background PCB contamination was used in the experimental study. The objective of this study is to investigate the difference in HOC concentration of worms exposed to: a) a grab sample of contaminated sediment (10.4% total organic carbon); and b) an initially clean mixture of sand and organic matter (the so-called biouptake layer), placed on top of the RCM-capped sediment during consolidation coupled solute transport experiments. In addition to the experimental data, the U.S. Army Corps of Engineers (USACE) biota-sediment accumulation factor (BSAF) database was validated and used to model biouptake of contaminants for certain cases. Results indicate that RCM capping reduced the average bioavailability of both PCBs and naphthalene by a factor of about 50. In fact, worms exposed to the RCM-protected biouptake layer show virtually the same HOC concentrations as those measured in the control worm samples. PMID:22386995

  8. Neutrophil myeloperoxidase and its substrates: formation of specific markers and reactive compounds during inflammation.

    PubMed

    Kato, Yoji

    2016-03-01

    Myeloperoxidase is an inflammatory enzyme that generates reactive hypochlorous acid in the presence of hydrogen peroxide and chloride ion. However, this enzyme also uses bromide ion or thiocyanate as a substrate to form hypobromous or hypothiocyanous acid, respectively. These species play important roles in host defense against the invasion of microorganisms. In contrast, these enzyme products modify biomolecules in hosts during excess inflammation, indicating that the action of myeloperoxidase is both beneficial and harmful. Myeloperoxidase uses other endogenous compounds, such as serotonin, urate, and l-tyrosine, as substrates. This broad-range specificity may have some biological implications. Target molecules of this enzyme and its products vary, including low-molecular weight thiols, proteins, nucleic acids, and lipids. The modified products represent biomarkers of myeloperoxidase action. Moderate inhibition of this enzyme might be critical for the prevention/modulation of excess, uncontrolled inflammatory events. Some phytochemicals inhibit myeloperoxidase, which might explain the reductive effect caused by the intake of vegetables and fruits on cardiovascular diseases. PMID:27013775

  9. Anthropogenic emissions of highly reactive volatile organic compounds inferred from oversampling of OMI HCHO columns

    NASA Astrophysics Data System (ADS)

    Zhu, L.; Jacob, D. J.; Mickley, L. J.; Marais, E. A.; Cohan, D. S.; Yoshida, Y.; Duncan, B. N.; Gonzalez Abad, G.; Chance, K.

    2014-12-01

    Satellite observations of formaldehyde (HCHO) columns provide top-down constraints on emissions of highly reactive volatile organic compounds (HRVOCs). This approach has been used previously to constrain emissions of isoprene from vegetation, but application to US anthropogenic emissions has been stymied by lack of a discernable HCHO signal. Here we show that oversampling of HCHO data from the Ozone Monitoring Instrument (OMI) for 2005-2008 enables quantitative detection of urban and industrial plumes in eastern Texas including Houston, Port Arthur, and Dallas/Fort Worth. By spatially integrating the individual urban/industrial HCHO plumes observed by OMI we can constrain the corresponding HCHO-weighted HRVOC emissions. Application to the Houston plume indicates a HCHO source of 260±110 kmol h-1 and implies a factor of 5.5±2.4 underestimate of anthropogenic HRVOC emissions in the US Environmental Protection Agency inventory. This approach allows us to monitor trends in HRVOC emissions over the US, in particular from the urban areas and oil/gas industry.

  10. Neutrophil myeloperoxidase and its substrates: formation of specific markers and reactive compounds during inflammation

    PubMed Central

    Kato, Yoji

    2016-01-01

    Myeloperoxidase is an inflammatory enzyme that generates reactive hypochlorous acid in the presence of hydrogen peroxide and chloride ion. However, this enzyme also uses bromide ion or thiocyanate as a substrate to form hypobromous or hypothiocyanous acid, respectively. These species play important roles in host defense against the invasion of microorganisms. In contrast, these enzyme products modify biomolecules in hosts during excess inflammation, indicating that the action of myeloperoxidase is both beneficial and harmful. Myeloperoxidase uses other endogenous compounds, such as serotonin, urate, and l-tyrosine, as substrates. This broad-range specificity may have some biological implications. Target molecules of this enzyme and its products vary, including low-molecular weight thiols, proteins, nucleic acids, and lipids. The modified products represent biomarkers of myeloperoxidase action. Moderate inhibition of this enzyme might be critical for the prevention/modulation of excess, uncontrolled inflammatory events. Some phytochemicals inhibit myeloperoxidase, which might explain the reductive effect caused by the intake of vegetables and fruits on cardiovascular diseases. PMID:27013775

  11. Reactivity of bis(organoamino)phosphanes with magnesium(II) compounds.

    PubMed

    Vrána, Jan; Jambor, Roman; Růžička, Aleš; Alonso, Mercedes; De Proft, Frank; Lyčka, Antonín; Dostál, Libor

    2015-03-14

    The reactivity of three phosphanes (PhP(NHR)2 [R = t-Bu (1), Ph (2)] and PhP(NEt2)(NHDip) (3) (where Dip = 2,6-i-Pr2C6H3)) with n-Bu2Mg and MeMgBr is presented. In the case of 1, the reaction with n-Bu2Mg gave [PhP(NHt-Bu)(Nt-Bu)]Mg(n-Bu) (4) or [PhP(NHt-Bu)(Nt-Bu)]2Mg (5) depending on the stoichiometry. The treatment of 1 with MeMgBr led to the phosphinate [Ph(H)P(Nt-Bu)2]2Mg (7) as a result of both the NH→PH tautomeric transformation and elimination of MgBr2 from the non-isolable intermediate [PhP(NHt-Bu)(Nt-Bu)]MgBr(THF) (6). Phosphane 2 reacted with n-Bu2Mg in a 1:1 molar ratio resulting in the formation of {[PhP(NPh)2]2Mg(THF)2}2 (8), but the analogous reaction in a 2:1 molar ratio yielded phosphinate [Ph(H)P(NPh)2]2Mg(THF) (9). The heteroleptic compound [Ph(H)P(NPh)2]MgBr(THF)2 (10) was obtained by the reaction of 2 with MeMgBr. Finally, the reaction of 3 with n-Bu2Mg and MeMgBr produced compounds [PhP(NEt2)(NDip)]2Mg (11) and {[PhP(NEt2)(NDip)2]Mg(μ-Br)(THF)}2 (12), respectively. All products were characterized using (1)H, (13)C{(1)H} and (31)P NMR spectroscopy and, except for compounds 4 and 6, their molecular structures were determined using single-crystal X-ray diffraction analysis. In addition, a theoretical study on plausible isomers of 10 was performed to provide additional evidence for the presence of a syn- and anti-isomer in dynamic equilibrium in a solution of 10. PMID:25652308

  12. Phase I Metabolic Stability and Electrophilic Reactivity of 2-Phenylaminophenylacetic Acid Derived Compounds.

    PubMed

    Pang, Yi Yun; Tan, Yee Min; Chan, Eric Chun Yong; Ho, Han Kiat

    2016-07-18

    Diclofenac and lumiracoxib are two highly analogous 2-phenylaminophenylacetic acid anti-inflammatory drugs exhibiting occasional dose-limiting hepatotoxicities. Prior data indicate that bioactivation and reactive metabolite formation play roles in the observed toxicity, but the exact chemical influence of the substituents remains elusive. In order to elucidate the role of chemical influence on metabolism related toxicity, metabolic stability and electrophilic reactivity were investigated for a series of structurally related analogues and their resulting metabolites. The resulting analogues embody progressive physiochemical changes through varying halogeno- and aliphatic substituents at two positions and were subjected to in vitro human liver microsomal metabolic stability and cell-based GSH depletion assays (to measure electrophilic reactivity). LC-MS/MS analysis of the GSH trapped reactive intermediates derived from the analogues was then used to identify the putative structures of reactive metabolites. We found that chemical modifications of the structural backbone led to noticeable perturbations of metabolic stability, electrophilic reactivity, and structures and composition of reactive metabolites. With the acquired data, the relationships between stability, reactivity, and toxicity were investigated in an attempt to correlate between Phase I metabolism and in vitro toxicity. A positive correlation was identified between reactivity and in vitro toxicity, indicating that electrophilic reactivity can be an indicator for in vitro toxicity. All in all, the effect of substituents on the structures and reactivity of the metabolites, however subtle the changes, should be taken into consideration during future drug design involving similar chemical features. PMID:27245204

  13. On the reactive adsorption of ammonia on activated carbons modified by impregnation with inorganic compounds.

    PubMed

    Bandosz, Teresa J; Petit, Camille

    2009-10-15

    Ammonia adsorption was studied under dynamic conditions, at room temperature, on activated carbons of different origins (coal-based, wood-based and coconut-shell-based carbons) before and after their impregnation with various inorganic compounds including metal chlorides, metal oxides and polycations. The role of humidity was evaluated by running tests in both dry and moist conditions. Adsorbents were analyzed before and after exposure to ammonia by thermal analyses, sorption of nitrogen, potentiometric titration, X-ray diffraction and FTIR spectroscopy. Results of breakthrough tests show significant differences in terms of adsorption capacity depending on the parent carbon, the impregnates and the experimental conditions. It is found that surface chemistry governs ammonia adsorption on the impregnated carbons. More precisely, it was demonstrated that a proper combination of the surface pH, the strength, type and amount of functional groups present on the adsorbents' surface is a key point in ammonia uptake. Water can have either positive or negative effects on the performance of adsorbents. It can enhance NH(3) adsorption capacity since it favors ammonia dissolution and thus enables reaction between ammonium ions and carboxylic groups from the carbons' surface. On the other hand, water can also reduce the performance from the strength of adsorption standpoint. It promotes dissolution of ammonia and that ammonia is first removed from the system when the adsorbent bed is purged with air. Ammonia, besides adsorption by van der Waals forces and dissolution in water, is also retained on the surface via reactive mechanisms such as acid-base reactions (Brønsted and Lewis) or complexation. Depending on the materials used and the experimental conditions, 6-47% ammonia adsorbed is strongly retained on the surface even when the bed is purged with air. PMID:19615690

  14. On the reactive adsorption of ammonia on activated carbons modified by impregnation with inorganic compounds

    SciTech Connect

    Bandosz, T.J.; Petit, C.

    2009-10-15

    Ammonia adsorption was studied under dynamic conditions, at room temperature, on activated carbons of different origins (coal-based, wood-based and coconut-shell-based carbons) before and after their impregnation with various inorganic compounds including metal chlorides, metal oxides and polycations. The role of humidity was evaluated by running tests in both dry and moist conditions. Adsorbents were analyzed before and after exposure to ammonia by thermal analyses, sorption of nitrogen, potentiometric titration, X-ray diffraction and FTIR spectroscopy. Results of breakthrough tests show significant differences in terms of adsorption capacity depending on the parent carbon, the impregnates and the experimental conditions. It is found that surface chemistry governs ammonia adsorption on the impregnated carbons. More precisely, it was demonstrated that a proper combination of the surface pH, the strength, type and amount of functional groups present on the adsorbents' surface is a key point in ammonia uptake. Water can have either positive or negative effects on the performance of adsorbents. It can enhance NH{sub 3} adsorption capacity since it favors ammonia dissolution and thus enables reaction between ammonium ions and carboxylic groups from the carbons' surface. On the other hand, water can also reduce the performance from the strength of adsorption standpoint. It promotes dissolution of ammonia and that ammonia is first removed from the system when the adsorbent bed is purged with air. Ammonia, besides adsorption by van der Waals forces and dissolution in water, is also retained on the surface via reactive mechanisms such as acid-base reactions (Bronsted and Lewis) or complexation. Depending on the materials used and the experimental conditions, 6-47% ammonia adsorbed is strongly retained on the surface even when the bed is purged with air.

  15. Antagonism between lipid-derived reactive carbonyls and phenolic compounds in the Strecker degradation of amino acids.

    PubMed

    Delgado, Rosa M; Hidalgo, Francisco J; Zamora, Rosario

    2016-03-01

    The Strecker-type degradation of phenylalanine in the presence of 2-pentanal and phenolic compounds was studied to investigate possible interactions that either promote or inhibit the formation of Strecker aldehydes in food products. Phenylacetaldehyde formation was promoted by 2-pentenal and also by o- and p-diphenols, but not by m-diphenols. This is consequence of the ability of phenolic compounds to be converted into reactive carbonyls and produce the Strecker degradation of the amino acid. When 2-pentenal and phenolic compounds were simultaneously present, an antagonism among them was observed. This antagonism is suggested to be a consequence of the ability of phenolic compounds to either react with both 2-pentenal and phenylacetaldehyde, or compete with other carbonyl compounds for the amino acids, a function that is determined by their structure. All these results suggest that carbonyl-phenol reactions may be used to modulate flavor formation produced in food products by lipid-derived reactive carbonyls. PMID:26471665

  16. Scale up tools in reactive extrusion and compounding processes. Could 1D-computer modeling be helpful?

    NASA Astrophysics Data System (ADS)

    Pradel, J.-L.; David, C.; Quinebèche, S.; Blondel, P.

    2014-05-01

    Industrial scale-up (or scale down) in Compounding and Reactive Extrusion processes is one of the most critical R&D challenges. Indeed, most of High Performances Polymers are obtained within a reactive compounding involving chemistry: free radical grafting, in situ compatibilization, rheology control... but also side reactions: oxidation, branching, chain scission... As described by basic Arrhenius and kinetics laws, the competition between all chemical reactions depends on residence time distribution and temperature. Then, to ensure the best possible scale up methodology, we need tools to match thermal history of the formulation along the screws from a lab scale twin screw extruder to an industrial one. This paper proposes a comparison between standard scale-up laws and the use of Computer modeling Software such as Ludovic® applied and compared to experimental data. Scaling data from a compounding line to another one, applying general rules (for example at constant specific mechanical energy), shows differences between experimental and computed data, and error depends on the screw speed range. For more accurate prediction, 1D-Computer Modeling could be used to optimize the process conditions to ensure the best scale-up product, especially in temperature sensitive reactive extrusion processes. When the product temperature along the screws is the key, Ludovic® software could help to compute the temperature profile along the screws and extrapolate conditions, even screw profile, on industrial extruders.

  17. Finger snapping during seizures.

    PubMed

    Overdijk, M J; Zijlmans, M; Gosselaar, P H; Olivier, A; Leijten, F S S; Dubeau, F

    2014-01-01

    We describe two patients who showed snapping of the right hand fingers during invasive intracranial EEG evaluation for epilepsy surgery. We correlated the EEG changes with the finger-snapping movements in both patients to determine the underlying pathophysiology of this phenomenon. At the time of finger snapping, EEG spread from the supplementary motor area towards the temporal region was seen, suggesting involvement of these sites. PMID:25667884

  18. Modulation of growth performance in disease: reactive nitrogen compounds and their impact on cell proteins.

    PubMed

    Elsasser, T H; Kahl, S; Rumsey, T S; Blum, J W

    2000-08-01

    During life, all animals encounter situations that challenge their capability for optimal growth. In reacting to immune challenges in the form of disease, homeostatic mechanisms attempt to overcome disharmony of the body's internal environment, or simply put, stress. The overall impact of stress revolves around a dynamic relationship between the level of challenge imparted on physiological systems and the degree of host response that is mounted in the process of detecting and reacting to the stress. In growing animals, the majority of milder stress encounters are manifest in terms of energetic inefficiencies and periods of reduced anabolism. In contrast, severe stress is often characterized by frank catabolism and tissue wasting. In some instances a level of stress (that might be termed a "stress breakpoint") is reached at which time the host response itself contributes to the cascade of negative effectors that further cause illness. These "breakpoint" responses are characterized by more intense acute responses to stress or a much more protracted duration of the response than would be expected given the nature of the stress. Key to understanding how growth in the young animal responds to infectious stresses is the recognition that (a) when immune responses that normally maintain health go awry, the reporters and effectors of the immune system (cytokines and the nitric oxide cascade) can contribute to stress disease processes and (b) reactive nitrogen compounds derived from the nitric oxide, as well as super oxide anion can modify intracellular proteins and block otherwise normal biochemical processes that regulate cell function. A key example of this is the loss of regulation of IGF-I by GH. As animals react more severely to disease stress, IGF-I concentrations in plasma decline progressively. Recent data derived from (LPS) challenges performed on young calves suggest that the prolonged decline in IGF-I is associated with the development of hepatic cytotoxicity

  19. Species profiles and normalized reactivity of volatile organic compounds from gasoline evaporation in China

    NASA Astrophysics Data System (ADS)

    Zhang, Yanli; Wang, Xinming; Zhang, Zhou; Lü, Sujun; Shao, Min; Lee, Frank S. C.; Yu, Jianzhen

    2013-11-01

    In China, fast increase in passenger cars and gasoline consumption with yet quite limited vapor recovery during gasoline distribution has procured growing concern about gasoline evaporation as an important emission source of volatile organic compounds (VOCs), particularly in megacities hard-hit by air quality problems. This study presents VOC species profiles related to major pathways of gasoline evaporative loss in China, including headspace displacement, refueling operations and spillage/leakage. Apart from liquid gasoline and headspace vapors, gasoline vapors emitted when refueling cars in service stations or tank trucks in oil marketing depots were also sampled in situ with vapor recovery units (VRUs) turning on/off. Alkanes, alkenes and aromatic hydrocarbons accounted for 55-66, 21-35 and 4-8% in refueling vapors, 59-72, 18-28 and 4-10% in headspace vapors and 33-51, 8-15 and 38-48% in liquid gasoline samples, respectively. During refueling with VRUs turning on, total VOCs in vapors were less than one fifth of that with VRUs turning off, and aromatic hydrocarbons had higher weight percentages of about 8% in contrast with that of about 4% during refueling with VRUs turning off. Refueling vapors, especially for that with VRUs turning off, showed a larger fraction of light hydrocarbons including C3-C5 light alkenes when compared to headspace vapors, probably due to splashing and disturbance during filling operation. In refueling or headspace vapors the ratios of i-pentane/benzene, i-pentane/toluene, and MTBE (methyl tert-butyl ether)/benzene ranged 8.7-57, 2.7-4.8, and 1.9-6.6, respectively; and they are distinctively much higher than those previously reported in vehicle exhausts. Calculated normalized reactivity or ozone formation potential of the gasoline vapors in China ranged 3.3-4.4 g O3 g-1 VOC, about twice that of gasoline headspace vapors reported in USA as a result of larger fractions of alkenes in China's gasoline vapors. The results suggested that

  20. Fingers that change color

    MedlinePlus

    ... conditions can cause fingers or toes to change color: Buerger disease Chilblains. Painful inflammation of small blood vessels. Cryoglobulinemia Frostbite Necrotizing vasculitis Peripheral artery disease ...

  1. Phenotypic assays to identify agents that induce reactive gliosis: a counter-screen to prioritize compounds for preclinical animal studies.

    PubMed

    Beckerman, Samuel R; Jimenez, Joaquin E; Shi, Yan; Al-Ali, Hassan; Bixby, John L; Lemmon, Vance P

    2015-09-01

    Astrocyte phenotypes change in a process called reactive gliosis after traumatic central nervous system (CNS) injury. Astrogliosis is characterized by expansion of the glial fibrillary acidic protein (GFAP) cytoskeleton, adoption of stellate morphologies, and differential expression of some extracellular matrix molecules. The astrocytic response immediately after injury is beneficial, but in the chronic injury phase, reactive astrocytes produce inhibitory factors (i.e., chondroitin sulfate proteoglycans [CSPGs]) that limit the regrowth of injured axons. There are no drugs that promote axon regeneration or functional recovery after CNS trauma in humans. To develop novel therapeutics for the injured CNS, we screened various libraries in a phenotypic assay to identify compounds that promote neurite outgrowth. However, the effects these compounds have on astrocytes are unknown. Specifically, we were interested in whether compounds could alter astrocytes in a manner that mimics the glial reaction to injury. To test this hypothesis, we developed cell-based phenotypic bioassays to measure changes in (1) GFAP morphology/localization and (2) CSPG expression/immunoreactivity from primary astrocyte cultures. These assays were optimized for six-point dose-response experiments in 96-well plates. The GFAP morphology assay is suitable for counter-screening with a Z-factor of 0.44±0.03 (mean±standard error of the mean; N=3 biological replicates). The CSPG assay is reproducible and informative, but does not satisfy common metrics for a "screenable" assay. As proof of principle, we tested a small set of hit compounds from our neurite outgrowth bioassay and identified one that can enhance axon growth without exacerbating the deleterious characteristics of reactive gliosis. PMID:26230074

  2. OH Reactivity and Potential SOA Yields from Volatile Organic Compounds and Other Trace Gases Measured in Controlled Laboratory Biomass Burns

    NASA Astrophysics Data System (ADS)

    Gilman, J. B.; Warneke, C.; Kuster, W. C.; Goldan, P. D.; Veres, P. R.; Roberts, J. M.; de Gouw, J. A.; Burling, I. R.; Yokelson, R. J.

    2010-12-01

    A comprehensive suite of instruments were used to characterize volatile organic compounds (VOCs) and other trace gases (e.g., CO, CH4, NO2, etc.) emitted from controlled burns of various fuel types common to the Southeastern and Southwestern United States. These laboratory-based measurements were conducted in February 2009 at the U.S. Department of Agriculture’s Fire Sciences Laboratory in Missoula, Montana. An on-line GC-MS provided highly speciated VOC measurements of alkenes, alkanes, oxygenates, aromatics, biogenics, and nitrogen-containing compounds during the flaming or smoldering phases of replicate burns. The speciated GC-MS “grab” samples were integrated with fast-response gas-phase measurements (e.g., PTR-MS, PTR-IT-MS, NI-PT-CIMS, and FTIR) in order to determine VOC emission ratios and the fraction of identified vs. unidentifiable mass detected by PTR-MS. Emission ratios were used to calculate OH reactivity, which is a measure of potential ozone formation, as well as potential secondary organic aerosol (SOA) yields from the various fuel types. Small oxygenated VOCs had the highest emission ratios of the compounds observed. Alkenes dominated the VOC OH reactivity, which occasionally exceeded 1000 s-1. Calculated SOA yields from known precursors were dominated by aromatic VOCs, such as toluene, naphthalene (C10H8), and 1,3-benzenediol (C6H6O2, resorcinol). The contribution of several compounds not typically reported in ambient air measurements, such as substituted furans (C4H4O), pyrroles (C4H5N), and unsaturated C9 aromatics (C9H10), on OH reactivity and SOA yields will be discussed.

  3. Ozone reactivity of biogenic volatile organic compound (BVOC) emissions during the Southeast Oxidant and Aerosol Study (SOAS)

    NASA Astrophysics Data System (ADS)

    Park, J.; Guenther, A. B.; Helmig, D.

    2013-12-01

    Recent studies on atmospheric chemistry in the forest environment showed that the total reactivity by biogenic volatile organic compound (BVOC) emission is still not well understood. During summer 2013, an intensive field campaign (Southeast Oxidant and Aerosol Study - SOAS) took place in Alabama, U.S.A. In this study, an ozone reactivity measurement system (ORMS) was deployed for the direct determination of the reactivity of foliage emissions. The ORMS is a newly developed measurement approach, in which a known amount of ozone is added to the ozone-free air sample stream, with the ORMS measuring ozone concentration difference between before and after a glass flask flow tube reaction vessel (2-3 minutes of residence time). Emissions were also collected onto adsorbent cartridges to investigate the discrepancy between total ozone reactivity observation and reactivity calculated from identified BVOC. Leaf and canopy level experiments were conducted by deploying branch enclosures on the three dominant tree species at the site (i.e. liquidambar, white oak, loblolly pine) and by sampling ambient air above the forest canopy. For the branch enclosure experiments, BVOC emissions were sampled from a 70 L Teflon bag enclosure, purged with air scrubbed for ozone, nitrogen oxides. Each branch experiment was performed for 3-5 days to collect at least two full diurnal cycle data. In addition, BVOCs were sampled using glass tube cartridges for 2 hours during daytime and 3 - 4 hours at night. During the last week of campaign, the inlet for the ORMS was installed on the top of scaffolding tower (~30m height). The ozone loss in the reactor showed distinct diurnal cycle for all three tree species investigated, and ozone reactivity followed patterns of temperature and light intensity.

  4. Rolling friction robot fingers

    NASA Technical Reports Server (NTRS)

    Vranish, John M. (Inventor)

    1992-01-01

    A low friction, object guidance, and gripping finger device for a robotic end effector on a robotic arm is disclosed, having a pair of robotic fingers each having a finger shaft slideably located on a gripper housing attached to the end effector. Each of the robotic fingers has a roller housing attached to the finger shaft. The roller housing has a ball bearing mounted centering roller located at the center, and a pair of ball bearing mounted clamping rollers located on either side of the centering roller. The object has a recess to engage the centering roller and a number of seating ramps for engaging the clamping rollers. The centering roller acts to position and hold the object symmetrically about the centering roller with respect to the X axis and the clamping rollers act to position and hold the object with respect to the Y and Z axis.

  5. Reactivity of polycyclic aromatic compounds (PAHs, NPAHs and OPAHs) adsorbed on natural aerosol particles exposed to atmospheric oxidants

    NASA Astrophysics Data System (ADS)

    Ringuet, Johany; Albinet, Alexandre; Leoz-Garziandia, Eva; Budzinski, Hélène; Villenave, Eric

    2012-12-01

    Reactivity of polycyclic aromatic compounds (PACs) adsorbed on natural aerosol particles exposed to different atmospheric oxidants (O3, OH and NO2/O3 mixture) was studied. Decay of polycyclic aromatic hydrocarbons (PAHs) and formation/decay of oxygenated PAHs (OPAHs) and nitrated PAHs (NPAHs) were monitored. Overall, benzo[a]pyrene appeared to be the most reactive PAH (degradation of 50%). Only its nitrated derivative, 6-nitrobenzo[a]pyrene, was significantly formed explaining just 0.4% of reacted benzo[a]pyrene. No other nitrated or oxygenated benzo[a]pyrene derivatives were detected. Interestingly, B[e]P and In[1,2,3,c,d]P, which are usually considered as quite stable PAHs, also underwent decay in all experiments. In presence of O3, ketones were significantly formed but their amount was not totally explained by decay of parent PAH. These results suggest that PAH derivatives could be formed from the reaction of other compounds than their direct parent PAHs and raise the question to know if the oxidation of methyl-PAHs, identified in vehicle-exhausts, could constitute this missing source of OPAHs. NPAHs were significantly formed in presence of O3/NO2 and OH. Surprisingly, NPAH formation was clearly observed during O3 experiments. Nitrated species, already associated with aerosol particles (NO3-, NO2-) or formed by ozonation of particulate nitrogen organic matter, could react with PAHs to form NPAHs. Heterogeneous formation of 2-nitropyrene from pyrene oxidation was for the first time observed, questioning its use as an indicator of NPAH formation in gaseous phase. Equally, formation of 2-nitrofluoranthene by heterogeneous reaction of fluoranthene with O3/NO2 was clearly shown, while only its formation by homogeneous processes (gaseous phase) is reported in the literature. Finally, results obtained highlighted the dependence of heterogeneous PAH reactivity with the substrate nature and the importance to focus reactivity studies on natural particles, whatever the

  6. Finger and toenail onycholysis.

    PubMed

    Zaias, N; Escovar, S X; Zaiac, M N

    2015-05-01

    Onycholysis - the separation of the nail plate from the nail bed occurs in fingers and toenails. It is diagnosed by the whitish appearance of the separated nail plate from the nail bed. In fingers, the majority is caused by trauma, manicuring, occupational or self-induced behavior. The most common disease producing fingernail onycholysis is psoriasis and pustular psoriasis. Phototoxic dermatitis, due to drugs can also produce finger onycholysis. Once the separation occurs, the environmental flora sets up temporary colonization in the available space. Finger onycholysis is most common in women. Candida albicans is often recovered from the onycholytic space. Many reports, want to associate the yeast as cause and effect, but the data are lacking and the treatment of the candida does not improve finger onycholysis. A reasonable explanation for the frequent isolation of Candida and Pseudomonas in fingernail onycholysis in women, is the close proximity the fingers have to the vaginal and gastrointestinal tract. Fifty per cent of humans harbour C. albicans in the GI tract and it is frequently carried to the vagina during hygienic practices. Finger onycholysis is best treated by drying the nail 'lytic' area with a hair blower, since all colonizing biota are moisture loving and perish in a dry environment. Toenail onycholysis has a very different etiology. It is mechanical, the result of pressure on the toes from the closed shoes, while walking, because of the ubiquitous uneven flat feet producing an asymmetric gait with more pressure on the foot with the flatter sole. PMID:25512134

  7. Multiple Fingers - One Gestalt.

    PubMed

    Lezkan, Alexandra; Manuel, Steven G; Colgate, J Edward; Klatzky, Roberta L; Peshkin, Michael A; Drewing, Knut

    2016-01-01

    The Gestalt theory of perception offered principles by which distributed visual sensations are combined into a structured experience ("Gestalt"). We demonstrate conditions whereby haptic sensations at two fingertips are integrated in the perception of a single object. When virtual bumps were presented simultaneously to the right hand's thumb and index finger during lateral arm movements, participants reported perceiving a single bump. A discrimination task measured the bump's perceived location and perceptual reliability (assessed by differential thresholds) for four finger configurations, which varied in their adherence to the Gestalt principles of proximity (small versus large finger separation) and synchrony (virtual spring to link movements of the two fingers versus no spring). According to models of integration, reliability should increase with the degree to which multi-finger cues integrate into a unified percept. Differential thresholds were smaller in the virtual-spring condition (synchrony) than when fingers were unlinked. Additionally, in the condition with reduced synchrony, greater proximity led to lower differential thresholds. Thus, with greater adherence to Gestalt principles, thresholds approached values predicted for optimal integration. We conclude that the Gestalt principles of synchrony and proximity apply to haptic perception of surface properties and that these principles can interact to promote multi-finger integration. PMID:26863671

  8. The pKa of Brønsted acids controls their reactivity with diazo compounds.

    PubMed

    Fei, Na; Sauter, Basilius; Gillingham, Dennis

    2016-06-14

    We study the O-alkylation of phosphate groups by alkyl diazo compounds in a range of small molecules and biopolymers. We show that the relatively high pKa of phosphate in comparison to the other naturally occurring Brønsted acids can be exploited to control alkylation selectivity. We provide a simple protocol for chemical modification of some of the most important instances of phosphates in natural compounds including in small molecule metabolites, nucleic acids, and peptides. PMID:27212133

  9. Governing processes for reactive nitrogen compounds in the atmosphere in relation to ecosystem, climatic and human health impacts

    NASA Astrophysics Data System (ADS)

    Hertel, O.; Skjøth, C. A.; Reis, S.; Bleeker, A.; Harrison, R.; Cape, J. N.; Fowler, D.; Skiba, U.; Simpson, D.; Jickells, T.; Kulmala, M.; Gyldenkærne, S.; Sørensen, L. L.; Erisman, J. W.; Sutton, M. A.

    2012-07-01

    Reactive nitrogen (Nr) compounds have different fates in the atmosphere due to differences in governing processes of physical transport, deposition and chemical transformation. Nr compounds addressed here include reduced nitrogen (NHx: ammonia (NH3) and its reaction product ammonium (NH4+)), oxidized nitrogen (NOy: nitrogen monoxide (NO) + nitrogen dioxide (NO2) and their reaction products) as well as organic nitrogen compounds (organic N). Pollution abatement strategies need to take into account these differences in the governing processes of these compounds when assessing their impact on ecosystem services, biodiversity, human health and climate. NOx (NO + NO2) emitted from traffic affects human health in urban areas where the presence of buildings increases the residence time in streets. In urban areas this leads to enhanced exposure of the population to NOx concentrations. NOx emissions have little impact on nearby ecosystems because of the small dry deposition rates of NOx. These compounds need to be converted into nitric acid (HNO3) before removal through deposition is efficient. HNO3 sticks quickly to any surface and is thereby either dry deposited or incorporated into aerosols as nitrate (NO3-). In contrast to NOx compounds, NH3 has potentially high impacts on ecosystems near the main agricultural sources of NH3 because of its large ground-level concentrations along with large dry deposition rates. Aerosol phase NH4+ and NO3- contribute significantly to background PM2.5 and PM10 (mass of aerosols with a diameter of less than 2.5 and 10 μm, respectively) with an impact on radiation balance as well as potentially on human health. Little is known quantitatively and qualitatively about organic N in the atmosphere, other than that it contributes a significant fraction of wet-deposited N, and is present in both gaseous and particulate forms in the atmosphere. Further studies are needed to characterize the sources, air chemistry and removal rates of organic N

  10. Evaluation of a horizontal permeable reactive barrier for preventing upward diffusion of volatile organic compounds through the unsaturated zone.

    PubMed

    Mahmoodlu, Mojtaba G; Hassanizadeh, S Majid; Hartog, Niels; Raoof, Amir; van Genuchten, Martinus Th

    2015-11-01

    Permeable reactive barriers are commonly used to treat contaminant plumes in the saturated zone. However, no known applications of horizontal permeable reactive barriers (HPRBs) exist for oxidizing volatile organic compounds (VOCs) in the unsaturated zone. In this study, laboratory column experiments were carried out to investigate the ability of a HPRB containing solid potassium permanganate, to oxidize the vapors of trichloroethylene (TCE), toluene, and ethanol migrating upward from a contaminated saturated zone. Results revealed that an increase in initial water saturation and HPRB thickness strongly affected the removal efficiency of the HPRB. Installing the HPRB relatively close to the water table was more effective due to the high background water content and enhanced diffusion of protons and/or hydroxides away from the HPRB. Inserting the HPRB far above the water table caused rapid changes in pH within the HPRB, leading to lower oxidation rates. The pH effects were included in a reactive transport model, which successfully simulated the TCE and toluene experimental observations. Simulations for ethanol were not affected by pH due to condensation of water during ethanol oxidation, which caused some dilution in the HRPB. PMID:26321530

  11. Growth behavior of intermetallic compounds during reactive diffusion between aluminum alloy 1060 and magnesium at 573-673 K

    NASA Astrophysics Data System (ADS)

    Xiao, Lin; Wang, Ning

    2015-01-01

    A potential new research reactor fuel design proposes to use U-Mo fuel in a Mg matrix clad with Al. Interdiffusion between the Mg containing fuel core and Al cladding can result in the formation of intermetallic compounds that can be detrimental to fuel element performance. The kinetics of the reactive diffusion in the binary Al-Mg system was experimentally studied. Layers of the intermetallic compounds, β (Al3Mg2) and γ (Al12Mg17) phases, were formed between the Al alloy 1060 and Mg during annealing. The β layer was observed to grow faster than the γ phase. The thickness of each layer can be expressed by a power function of the annealing time with the exponent n close to 0.5 for the β phase and less than 0.5 for the γ phase. The results suggest that the growth of β phase is controlled by lattice diffusion and that of the γ phase by grain boundary and lattice diffusion. Metallographic examination showed the grain boundary diffusion in the form of columnar growth of γ phase during annealing. Based on the reactive diffusion equation developed in this work, in the absence of irradiation effects, it will take more than 110 h to consume a half thickness of 400 μm of the cladding.

  12. Flux estimates and OH reaction potential of reactive biogenic volatile organic compounds (BVOCs) from a mixed northern hardwood forest

    NASA Astrophysics Data System (ADS)

    Ortega, John; Helmig, Detlev; Guenther, Alex; Harley, Peter; Pressley, Shelley; Vogel, Christoph

    Diurnal branch-level emission rates of biogenic volatile organic compounds (BVOC) including isoprene, monoterpenes (MT), and sesquiterpenes (SQT) were determined at the University of Michigan Biological Station for the tree species red maple ( Acer rubrum), red oak ( Quercus rubra), paper birch ( Betula papyrifera), white pine ( Pinus strobus), and big tooth aspen ( Populus grandidentata). These emission rates were combined with detailed biomass distribution and meteorological data and incorporated into the canopy model, model of emissions of gasses and aerosols from nature (MEGAN), for estimating whole-canopy fluxes of isoprene. The modeled half-hour fluxes (mgCm-2h-1) and cumulative seasonal fluxes (mgCm-2) compared favorably with results from direct, canopy-level eddy covariance (EC) isoprene measurements; modeled cumulative seasonal flux deviated less than 30% from the EC results. Significant MT emissions were found from four of the five tree species. MT emissions from three of these were both light- and temperature-dependent and were approximately one order of magnitude greater than light-independent MT emissions. SQT emissions were identified from three of the five tree species. The model was modified to incorporate SQT and both light-dependent and light-independent MT emissions for determining fluxes. Isoprene comprised >95% of the total terpenoid flux with MT and SQT comprising 4% and 0.3%, respectively. The average cumulative fluxes (in mgCm-2) from June through September were 2490 for isoprene, 105 for MT, and 7 for SQT. A simple box model analysis was used to estimate the contribution of the isoprene, MT, and SQT emissions to the total OH reactivity. These results confirm that isoprene dominates OH reactions especially during daytime hours. Emissions of reactive MT and SQT increase the BVOC+OH reactivity, but are still lower than estimates of BVOC fluxes at this site necessary for affecting OH reactivity to the significant degree suggested by recent

  13. Fingering in Confined Elastic Layers

    NASA Astrophysics Data System (ADS)

    Biggins, John; Mahadevan, L.; Wei, Z.; Saintyves, Baudouin; Bouchaud, Elizabeth

    2015-03-01

    Fingering has recently been observed in soft highly elastic layers that are confined between and bonded to two rigid bodies. In one case an injected fluid invades the layer in finger-like protrusions at the layer's perimeter, a solid analogue of Saffman-Taylor viscous fingering. In a second case, separation of the rigid bodies (with maintained adhesion to the layer) leads air to the formation of similar fingers at the layer's perimeter. In both cases the finger formation is reversible: if the fluid is removed or the separation reduced, the fingers vanish. In this talk I will discuss a theoretical model for such elastic fingers that shows that the origin of the fingers is large-strain geometric non-linearity in the elasticity of soft solids. Our simplified elastic model unifies the two types of fingering and accurately estimates the thresholds and wavelengths of the fingers.

  14. Correlations between chemical reactivity and mutagenic activity against S. typhimurium TA100 for alpha-dicarbonyl compounds as a proof of the mutagenic mechanism.

    PubMed

    Rodríguez Mellado, J M; Ruiz Montoya, M

    1994-01-16

    The mutagenic activities in the Ames test against S. typhimurium TA100 for a series of alpha-dicarbonyl compounds are examined together with the formation constants of the adducts formed between such compounds and guanine and guanosine. Correlations between the equilibrium constants, the apparent reaction enthalpies, and the mutagenic activity are presented. These correlations imply that the mutagenic activity is related to the chemical reactivity of the dicarbonyl compounds with the puric bases. PMID:7506369

  15. Tendon Driven Finger Actuation System

    NASA Technical Reports Server (NTRS)

    Ihrke, Chris A. (Inventor); Reich, David M. (Inventor); Bridgwater, Lyndon (Inventor); Linn, Douglas Martin (Inventor); Askew, Scott R. (Inventor); Diftler, Myron A. (Inventor); Platt, Robert (Inventor); Hargrave, Brian (Inventor); Valvo, Michael C. (Inventor); Abdallah, Muhammad E. (Inventor); Permenter, Frank Noble (Inventor); Mehling, Joshua S. (Inventor)

    2013-01-01

    A humanoid robot includes a robotic hand having at least one finger. An actuation system for the robotic finger includes an actuator assembly which is supported by the robot and is spaced apart from the finger. A tendon extends from the actuator assembly to the at least one finger and ends in a tendon terminator. The actuator assembly is operable to actuate the tendon to move the tendon terminator and, thus, the finger.

  16. Interactions between volatile organic compounds and reactive halogen in the tropical marine atmosphere using WRF-Chem

    NASA Astrophysics Data System (ADS)

    Badia, Alba; Reeves, Claire E.; Baker, Alex; Volkamer, Rainer; von Glasow, Roland

    2016-04-01

    Halogen species (chlorine, bromine and iodine) are known to play an important role in the chemistry and oxidizing capacity of the troposphere, particularly in the marine boundary layer (MBL). Reactive halogens cause ozone (O3) destruction, change the HOx and NOX partitioning, affect the oxidation of volatile organic compounds (VOCs) and mercury, reduce the lifetime of methane, and take part in new particle formation. Numerical models predicted that reactive halogen compounds account for 30% of O3 destruction in the MBL and 5-20% globally. There are indications that the chemistry of reactive halogens and oxygenated VOCs (OVOCs) in the tropics are inter-related. Moreover, the presence of aldehydes, such as glyoxal (CHOCHO), has a potential impact on radical cycling and secondary organic aerosol (SOA) formation in the MBL and free troposphere (FT). Model calculations suggest aldehydes to be an important sink for bromine atoms and hence competition for their reaction with O3 forming BrO and so illustrating a link between the cycles of halogens and OVOCs in the marine atmosphere. The main objective of this contribution is to investigate the atmospheric chemistry in the tropical East Pacific with a focus on reactive halogens and OVOCs and their links using the latest version of the Weather Research and Forecasting (WRF) model coupled with Chemistry (WRF-Chem) and field data from the TORERO campaign. WRF-Chem is a highly flexible community model for atmospheric research where aerosol-radiation-cloud feedback processes are taken into account. Our current reaction mechanism in WRF-Chem is based on the MOZART mechanism and has been extended to include bromine, chlorine and iodine chemistry. The MOZART mechanism includes detailed gas-phase chemistry of CHOCHO formation as well as state-of-the-science pathways to form SOA. Oceanic emissions of aldehydes, including CHOCHO, and of organic halogens based on measurements from the TORERO campaign have been added into the model. Sea

  17. Development of a QSAR for worst case estimates of acute toxicity of chemically reactive compounds.

    PubMed

    Freidig, A P; Dekkers, S; Verwei, M; Zvinavashe, E; Bessems, J G M; van de Sandt, J J M

    2007-05-15

    Future EU legislations enforce a fast hazard and risk assessment of thousands of existing chemicals. If conducted by means of present data requirements, this assessment will use a huge number of test animals and will be neither cost nor time effective. The purpose of the current research was to develop methods to increase the acceptability of in vitro data for classification and labelling regarding acute toxicity. For this purpose, a large existing database containing in vitro and in vivo data was analysed. For more than 300 compounds in the database, relations between in vitro cytotoxicity and rat or mouse intravenous and oral in vivo LD50 values were re-evaluated and the possibilities for definition of mechanism based chemical subclasses were investigated. A high in vitro-in vivo correlation was found for chemicals classified as irritants. This can be explained by a shared unspecific cytotoxicity of these compounds which will act as the predominant mode of action for both endpoints, irritation and acute toxicity. For this subclass, which covered almost 40% of all compounds in the database, the LD50 values after intravenous dosing could be predicted with high accuracy. A somewhat lower accuracy was found for the prediction of oral LD50 values based on in vitro cytotoxicity data. Based on this successful correlation, a classification and labelling scheme was developed, that includes a hazard based definition of the applicability domain (irritants) and a prediction of the labelling of compounds for their acute iv and oral toxicity. The scheme was tested by an external validation. PMID:17462838

  18. Marine and terrestrial sources of reactive volatile organic compounds and their impact on the tropospheric ozone chemistry of the earth

    NASA Astrophysics Data System (ADS)

    Riemer, Daniel David

    Two areas integral to the global cycle of tropospheric ozone were studied. The first segment of this investigation involved the study of marine ecosystems to define the sources of nonmethane hydrocarbons (NMHCs) in the surface ocean. This included laboratory and field investigations conducted to determine the function and importance of dissolved organic matter (DOM) in the abiotic photochemical production of nonmethane hydrocarbons (NMHCs) in surface seawater. Concurrently, phytoplankton were investigated as a biogenic source of NMHCs in the surface ocean. Low molecular weight alkenes, compounds observed in the greatest quantities in the surface ocean, are formed almost exclusively as a result of DOM-mediated photochemistry. Isoprene was found to be produced by all phytoplankton species investigated. The primary sink for NMHCs found in surface seawater was gas exchange. The second segment of this study focused on the prevalence of NMHCs and oxygenated volatile organic compounds (OVOCs) in the rural southeastern United States. To characterize the importance of NMHCs and OVOCs to the process of atmospheric reactivity and tropospheric ozone chemistry, mixing ratios for a number of NMHCs and OVOCs were determined. Isoprene and its primary oxidation products, methacrolein and methyl vinyl ketone, were observed to be the dominant hydroxyl radical (OH) sink in the rural atmosphere. Certain OVOCs, namely methanol, acetone and acetaldehyde-although not as important on a reactivity basis-were the most prevalent in terms of mass. Methanol was the dominant OVOC measured in the rural atmosphere and serves as an important source of formaldehyde in the rural atmosphere. On the basis of the mixing ratio patterns exhibited by many of the OVOCs present in the rural atmosphere, considerable biogenic sources are likely.

  19. Isoprene Epoxydiols as Precursors to Secondary Organic Aerosol Formation: Acid-Catalyzed Reactive Uptake Studies with Authentic Compounds

    PubMed Central

    Lin, Ying-Hsuan; Zhang, Zhenfa; Docherty, Kenneth S.; Zhang, Haofei; Budisulistiorini, Sri Hapsari; Rubitschun, Caitlin L.; Shaw, Stephanie L.; Knipping, Eladio M.; Edgerton, Eric S.; Kleindienst, Tadeusz E.; Gold, Avram; Surratt, Jason D.

    2011-01-01

    Isoprene epoxydiols (IEPOX), formed from the photooxidation of isoprene under low-NOx conditions, have recently been proposed as precursors of secondary organic aerosol (SOA) on the basis of mass spectrometric evidence. In the present study, IEPOX isomers were synthesized in high purity (> 99%) to investigate their potential to form SOA via reactive uptake in a series of controlled dark chamber studies followed by reaction product analyses. IEPOX-derived SOA was substantially observed only in the presence of acidic aerosols, with conservative lower-bound yields of 4.7–6.4% for β-IEPOX and 3.4–5.5% for δ-IEPOX, providing direct evidence for IEPOX isomers as precursors to isoprene SOA. These chamber studies demonstrate that IEPOX uptake explains the formation of known isoprene SOA tracers found in ambient aerosols, including 2-methyltetrols, C5-alkene triols, dimers, and IEPOX-derived organosulfates. Additionally, we show reactive uptake on the acidified sulfate aerosols supports a previously unreported acid-catalyzed intramolecular rearrangement of IEPOX to cis- and trans-3-methyltetrahydrofuran-3,4-diols (3-MeTHF-3,4-diols) in the particle phase. Analysis of these novel tracer compounds by aerosol mass spectrometry (AMS) suggests that they contribute to a unique factor resolved from positive matrix factorization (PMF) of AMS organic aerosol spectra collected from low-NOx, isoprene-dominated regions influenced by the presence of acidic aerosols. PMID:22103348

  20. 2-Hydrazinoquinoline: a reactive matrix for matrix-assisted laser desorption/ionization mass spectrometry to detect gaseous carbonyl compounds.

    PubMed

    Shigeri, Yasushi; Kamimura, Takuya; Ando, Masanori; Uegaki, Koichi; Sato, Hiroaki; Tani, Fumito; Arakawa, Ryuichi; Kinumi, Tomoya

    2016-01-01

    The sensitivity, range of applications, and reaction mechanism of 2-hydrazinoquinoline as a reactive matrix for matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) were examined. Using a reaction chamber (125L) equipped with a stirring fan and a window for moving the MALDI-MS plate and volatile samples in and out, the sensitivities of 2-hydrazinoquinoline to gaseous aldehydes (formaldehyde, acetaldehyde, propionaldehyde, and n-butyraldehyde) and ketones (acetone, methyl ethyl ketone, and methyl isobutyl ketone) were determined to be at least parts per million (ppm) levels. On the other hand, carboxylic acids (formic acid, acetic acid, propionic acid, and butyric acid) and esters (ethyl acetate, pentyl acetate, isoamyl acetate, and methyl salicylate) could not be detected by 2-hydrazinoquinoline in MALDI-MS. In addition to 2,4-dinitrophenylhydrazine, a common derivatization reagent for analyzing carbonyl compounds quantitatively in gas chromatography and liquid chromatography, the dissolution of 2-hydrazinoquinoline in an acidic solution, such as trifluoroacetic acid, was essential for its function as a reactive matrix for MALDI- MS. PMID:27419901

  1. Photosensitized Production of Atmospherically Reactive Organic Compounds at the Air/Aqueous Interface

    PubMed Central

    2015-01-01

    We report on experiments that probe photosensitized chemistry at the air/water interface, a region that does not just connect the two phases but displays its own specific chemistry. Here, we follow reactions of octanol, a proxy for environmentally relevant soluble surfactants, initiated by an attack by triplet-state carbonyl compounds, which are themselves concentrated at the interface by the presence of this surfactant. Gas-phase products are determined using PTR-ToF-MS, and those remaining in the organic layer are determined by ATR-FTIR spectroscopy and HPLC-HRMS. We observe the photosensitized production of carboxylic acids as well as unsaturated and branched-chain oxygenated products, compounds that act as organic aerosol precursors and had been thought to be produced solely by biological activity. A mechanism that is consistent with the observations is detailed here, and the energetics of several key reactions are calculated using quantum chemical methods. The results suggest that the concentrating nature of the interface leads to its being a favorable venue for radical reactions yielding complex and functionalized products that themselves could initiate further secondary chemistry and new particle formation in the atmospheric environment. PMID:26068588

  2. Photosensitized Production of Atmospherically Reactive Organic Compounds at the Air/Aqueous Interface.

    PubMed

    Fu, Hongbo; Ciuraru, Raluca; Dupart, Yoan; Passananti, Monica; Tinel, Liselotte; Rossignol, Stéphanie; Perrier, Sebastien; Donaldson, D James; Chen, Jianmin; George, Christian

    2015-07-01

    We report on experiments that probe photosensitized chemistry at the air/water interface, a region that does not just connect the two phases but displays its own specific chemistry. Here, we follow reactions of octanol, a proxy for environmentally relevant soluble surfactants, initiated by an attack by triplet-state carbonyl compounds, which are themselves concentrated at the interface by the presence of this surfactant. Gas-phase products are determined using PTR-ToF-MS, and those remaining in the organic layer are determined by ATR-FTIR spectroscopy and HPLC-HRMS. We observe the photosensitized production of carboxylic acids as well as unsaturated and branched-chain oxygenated products, compounds that act as organic aerosol precursors and had been thought to be produced solely by biological activity. A mechanism that is consistent with the observations is detailed here, and the energetics of several key reactions are calculated using quantum chemical methods. The results suggest that the concentrating nature of the interface leads to its being a favorable venue for radical reactions yielding complex and functionalized products that themselves could initiate further secondary chemistry and new particle formation in the atmospheric environment. PMID:26068588

  3. Temporal distribution, behaviour and reactivities of BTEX compounds in a suburban Atlantic area during a year.

    PubMed

    Pérez-Rial, Débora; López-Mahía, Purificación; Muniategui-Lorenzo, Soledad; Prada-Rodríguez, Darío

    2009-06-01

    The temporal distribution of BTEX compounds (benzene, toluene, ethylbenzene and xylene isomers) in ambient air was studied in a suburban Atlantic area in the northwest of Spain. These compounds mean serious risks for public and occupational health and for biological and physical environments. A total of 1200 samples were analysed during a year, and in most of the samples toluene was the most abundant VOC followed by benzene or m+p-xylene. The average concentrations were 1.62, 2.15, 0.60, 0.94 and 0.47 microg m(-3) for benzene, toluene, ethylbenzene, m+p-xylenes and o-xylene respectively, although they reached values as high as 50.53, 28.57, 21.33, 46.13 and 22.74 microg m(-3) for the compounds in the same order. An exhaustive study was carried out to establish how both emission sources and the climatic conditions affected the BTEX levels measured in the outskirts of a small city. Wind directions and speeds, daily and seasonal BTEX profiles, ratios among the concentrations measured in the sampling site, in the city centre and in the fuels commonly used by the cars in the city were studied. The pollution roses revealed the presence of diffuse BTEX sources affecting the sampling point, although all the compounds reached their highest levels when the wind blew from an industrial area in the SW of the city. The daily BTEX profiles were well-correlated with the traffic pattern in the accesses to the city and the seasonal profile showed that the highest concentrations were reported in summertime. The ratios T/B, m+p-X/B and o-X/B were 1.32, 0.58 and 0.29 respectively; these values were lower than the ones reported in previous studies carried out in the centre of the same city. This could be caused by the major distance from the sampling point to the city centre and by the changes in the fuels and in the kind of vehicles used in the city. The correlation coefficients among the TEX fraction were always higher than 0.72 but benzene only showed a good correlation with these

  4. Osseointegrated finger prostheses.

    PubMed

    Doppen, P; Solomons, M; Kritzinger, S

    2009-02-01

    Amputation of a digit can lead to functional and psychological problems and patients can benefit from digital prostheses. Unfortunately, standard prostheses are often unstable, particularly when fitted over short amputation stumps. Prosthesis fixation by osseointegration is widely used in oral and extraoral applications and may help avoid the problem of instability. This paper reports the results of four patients with five finger amputations who were treated with osseointegrated implants to attach finger prostheses. One implant failed to osseointegrate and the procedure was abandoned. Three patients were successfully treated to completion of three finger prostheses and are extremely satisfied with their outcomes, both cosmetically and functionally, with osseoperception reported by all three patients. PMID:19091736

  5. Oxidation of sulfur compounds in petroleum residues: reactivity-structural relationships

    SciTech Connect

    Petersen, J.C.; Dorrence, S.M.; Nazir, M.; Plancher, H.; Barbour, F.A.

    1981-09-01

    Studies have been made on the reactivity of sulfur entities in oxidized asphalts and oxidized petroleum distillation residues during air oxidation. Asphalts are referred to as residues. The oxidation of these materials includes the rapid formation of an unsymmetrical ir band at ca 1030/cm. Sulfoxides are not normally found in unoxidized petroleum residues, but develop rapidly during air aging. Their presence in these residues has been inferred from their specific bands in ir spectra. Confirmation of sulfoxides was obtained from deoxygenation with chlorocarbenes and decomposition with bromine and peracetic acid. Hydroperoxides in amounts that might interfere with sulfoxide determination were not found in oxidated residues. The concentration of sulfoxides formed during air oxidation was found to rapidly reach a maximum value and to remain constant on further oxidation of the residue. Model studies indicate that hydroperoxides play a role in sulfoxide formation. The data show that both alkyl and aryl sulfides were present in aliphatic residues, that predominantly alkyl types were oxidized during oxidative aging in air and that concentrations of the alkyl and aryl types vary with crude source. Peracetic acid oxidation of the residues indicated that most of the sulfur present was in the form of sulfides. 2 figures, 6 tables.

  6. Multi-fingered robotic hand

    NASA Technical Reports Server (NTRS)

    Ruoff, Carl F. (Inventor); Salisbury, Kenneth, Jr. (Inventor)

    1990-01-01

    A robotic hand is presented having a plurality of fingers, each having a plurality of joints pivotally connected one to the other. Actuators are connected at one end to an actuating and control mechanism mounted remotely from the hand and at the other end to the joints of the fingers for manipulating the fingers and passing externally of the robot manipulating arm in between the hand and the actuating and control mechanism. The fingers include pulleys to route the actuators within the fingers. Cable tension sensing structure mounted on a portion of the hand are disclosed, as is covering of the tip of each finger with a resilient and pliable friction enhancing surface.

  7. Basalt Reactivity in the Presence of H2O-Saturated Supercritical CO2 Containing Gaseous Sulfur Compounds

    NASA Astrophysics Data System (ADS)

    Schaef, H. T.; McGrail, P.; Owen, A. T.

    2009-12-01

    Future impacts of climate change may be minimized by capture of emissions, primarily CO2 from fossil-fueled electric generating stations and subsequent sequestration in deep geologic formations. Injection of dry liquid CO2 into porous geologic reservoirs for long term storage is expected to eventually form a buoyant water-saturated bubble of supercritical fluid. Depending on purification processes and underground injection control regulations, the injected CO2 also could contain trace compounds associated with flue gas streams (SO2, N2, and O2). Once injected, the scCO2 will absorb water (1500 to 3000 ppmw) until becoming immobilized by reservoir trapping mechanisms. Reactivity of the water-bearing scCO2 with silicate minerals is relatively unknown and could have impacts on long term reservoir seal integrity and trapping by mineralization. To examine the reactivity of H2O-saturated scCO2, basalt experiments were conducted at pressures and temperatures relevant to geologic sequestration. Reaction products differed considerably depending on the gas mixtures used and type of basalt. In the presence of H2O-saturated CO2, the Newark Basin basalt reacted to produce secondary mineralization with needle-like morphologies and chemistries similar to aragonite. Exposing the same basalt to a CO2-H2S mixture (H2O saturated) produced two types of reaction products: carbonates in the form of small discrete nodules or needles and metallic-like circular areas similar in chemistry to pyrite and marcarsite. Tests conducted in the presence of CO2-SO2 produced the most extensive surface reaction products observed during the experiments. Some basalts were completely coated in white precipitate identified as a mixture of gypsum, sulfate bearing minerals (rozenite and melanterite), and a magnesium sulfate compound (MgSO4 ●5H2O). Hawaiian flow top basalts contained extensive reaction products including magnesium sulfate (MgSO4●6H2O), which formed on the large olivine crystals present

  8. Reactivity of tracheal smooth muscles in albino rats with experimental diabetes mellitus treated with a new complex compound of oxovanadium (IV) and isonicotinic acid hydrazide.

    PubMed

    Khafiz'yanova, R Kh; Minnebaev, M M; Gallyamov, R M; Latypov, R S; Gosmanov, A R; Aleeva, G N

    2003-06-01

    We studied functional properties of tracheal smooth muscle cells in rats with diabetes mellitus. Reactivity of tracheal smooth muscles increased in rats with experimental alloxan-induced diabetes mellitus. A new complex compound of oxovanadium (IV) and isonicotinic acid hydrazide affected reactivity of tracheal smooth muscles in albino rats with experimental type I diabetes mellitus. This new organic vanadium-containing compound reduced contractility of tracheal smooth muscles in rats and potentiated relaxation of smooth muscle cells in the trachea in response to exogenous nitric oxide. PMID:12937677

  9. Influence of coffee genotype on bioactive compounds and the in vitro capacity to scavenge reactive oxygen and nitrogen species.

    PubMed

    Rodrigues, Naira Poerner; Salva, Terezinha de Jesus Garcia; Bragagnolo, Neura

    2015-05-20

    The influence of green coffee genotype on the bioactive compounds and the in vitro antioxidant capacity against the principal reactive oxygen (ROO(•), H2O2, HO(•), and HOCl) and nitrogen (NO(•) and ONOO(-)) species of biological relevance was investigated. This is the first report on the capacity of green coffee to scavenge H2O2, HOCl, and NO(•). Variations in the contents of total chlorogenic acids (22.9-37.9 g/100 g), cinnamoyl-amino acid conjugates (0.03-1.12 g/100 g), trigonelline (3.1-6.7 g/100 g), and caffeine (3.9-11.8 g/100 g) were found. Hydrophilic extracts of Coffea canephora and Coffea kapakata were the most potent scavengers of ROO(•), H2O2, HO(•), NO(•), and ONOO(-) due to their chlorogenic acid contents, which were, on average, 30% higher than those found in Coffea arabica and Coffea racemosa. The results showed that genotype is a determinant characteristic in the bioactive compound contents and consequently in the antioxidant capacity of green coffee. PMID:25910038

  10. Near-Roadway Emission of Reactive Nitrogen Compounds and Other Non-Criteria Pollutants at a Southern California Freeway Site

    NASA Astrophysics Data System (ADS)

    Moss, J. A.; Baum, M.; Castonguay, A. E.; Aguirre, V., Jr.; Pesta, A.; Fanter, R. K.; Anderson, M.

    2015-12-01

    Emission control systems in light-duty motor vehicles (LDMVs) have played an important role in improving regional air quality by dramatically reducing the concentration of criteria pollutants (carbon monoxide, hydrocarbons, and nitrogen oxides) in exhaust emissions. Unintended side-reactions occurring on the surface of three-way catalysts may lead to emission of a number of non-criteria pollutants whose identity and emission rates are poorly understood. A series of near-roadway field studies conducted between 2009-2015 has investigated LDMV emissions of these pollutants with unprecedented depth of coverage, including reactive nitrogen compounds (NH3, amines, HCN, HONO, and HNO3), organic peroxides, and carbonyl compounds (aldehydes, ketones, and carboxylic acids). Methods to collect these pollutants using mist chambers, annular denuders, impingers, and solid-phase cartridges and quantify their concentration using GC-MS, LC-MS/MS, IC, and colorimetry were developed and validated in the laboratory and field. These methods were subsequently used in near-roadway field studies where the concentrations of the target compounds integrated over 1-4 hour blocks were measured at the edge of a freeway and at a background site 140 m from the roadway. Concentrations followed a steep decreasing gradient from the freeway to the background site. Emission factors (pollutant mass emitted per mass fuel consumed) were calculated by carbon mass balance using the difference in concentration measured between the freeway and background sites for the emitted pollutant and CO2 as a measure of carbon mass in the vehicle exhaust. The significance of these results will be discussed in terms of emissions inventories in the South Coast Air Basin of California, emission trends at this site over the period of 2009-2015, and for NH3, emission measurements conducted by our group and others over the period 2000-2015.

  11. Electrochemical and theoretical analysis of the reactivity of shikonin derivatives: dissociative electron transfer in esterified compounds.

    PubMed

    Armendáriz-Vidales, Georgina; Frontana, Carlos

    2014-09-01

    An electrochemical and theoretical analysis of a series of shikonin derivatives in aprotic media is presented. Results showed that the first electrochemical reduction signal is a reversible monoelectronic transfer, generating a stable semiquinone intermediate; the corresponding E(I)⁰ values were correlated with calculated values of electroaccepting power (ω(+)) and adiabatic electron affinities (A(Ad)), obtained with BH and HLYP/6-311++G(2d,2p) and considering the solvent effect, revealing the influence of intramolecular hydrogen bonding and the substituting group at position C-2 in the experimental reduction potential. For the second reduction step, esterified compounds isobutyryl and isovalerylshikonin presented a coupled chemical reaction following dianion formation. Analysis of the variation of the dimensionless cathodic peak potential values (ξ(p)) as a function of the scan rate (v) functions and complementary experiments in benzonitrile suggested that this process follows a dissociative electron transfer, in which the rate of heterogeneous electron transfer is slow (~0.2 cm s(-1)), and the rate constant of the chemical process is at least 10(5) larger. PMID:25007856

  12. Reactivity of thiosemicarbazides with redox active metal ions: controlled formation of coordination complexes versus heterocyclic compounds.

    PubMed

    López-Torres, Elena; Dilworth, Jonathan R

    2009-01-01

    The reactions of 1,1-dimethyl-4-phenylthiosemicarbazide (LH) with Cu(II) and Sn(IV) have been investigated. If THF or methanol is used as solvent with Cu(II), oxidative cyclisation and coupling are observed, yielding a 1,2,4-thiadiazole or a 1,3,4-thiadiazolium salt. SnI(4) is also able to induce oxidative coupling of two thiosemicarbazide ligands, yielding 1,2,4-thiadiazolium or 1,2,4-triazolium salts, with I(3)(-) as the counterion, depending on the reaction conditions. By contrast, reaction of LH with SnI(4) in acetone yields a 1,3-thiazolium salt, with I(-) as counterion. Reaction with Cu(II) salts or SnI(4) in basic media leads to the formation of metal complexes containing two deprotonated thiosemicarbazide ligands. In the reaction of CuCl(2) in water in the presence of acid a complex containing two neutral ligands is obtained. Reactions with SnCl(4) are not able to induce ligand cyclisation, although a coordination compound with two neutral ligands was isolated from methanol. PMID:19180593

  13. Repair of webbed fingers - slideshow

    MedlinePlus

    ... gov/ency/presentations/100096.htm Repair of webbed fingers - series—Normal anatomy To use the sharing features ... Health Solutions, Ebix, Inc. Related MedlinePlus Health Topics Finger Injuries and Disorders A.D.A.M., Inc. ...

  14. Three-Fingered Robot Hand

    NASA Technical Reports Server (NTRS)

    Ruoff, C. F.; Salisbury, J. K.

    1984-01-01

    Mechanical joints and tendons resemble human hand. Robot hand has three "human-like" fingers. "Thumb" at top. Rounded tips of fingers covered with resilient material provides high friction for griping. Hand potential as prosthesis for humans.

  15. Spiral viscous fingering.

    NASA Astrophysics Data System (ADS)

    Nagatsu, Yuichiro; Hayashi, Atsushi; Kato, Yoshihito; Tada, Yutaka

    2006-11-01

    When a less-viscous fluid displaces a more-viscous fluid in a radial Hele-Shaw cell, viscous fingering pattern is believed to develop in a radial direction. We performed experiments on viscous fingering in a radial Hele-Shaw cell when a polymer solution, a sodium polyacrylate (SPA) solution is used as the more-viscous fluid and the trivalent iron (Fe^3+) solution is as the less-viscous fluid. The experiment was done by varying the concentration of Fe^3+, cFe3+. We have found that viscous fingering pattern develops spirally when cFe3+ is larger than a threshold value, while the pattern develops in a radial direction for small cFe3+. We confirmed from different experiments that an instantaneous chemical reaction takes place between SPA solution and Fe^3+ solution. The chemical reaction produces precipitation and significantly reduces the viscosity of the SPA solution. The quantity of the precipitation is increased with cFe3+. We will make a discussion on the relationship between the formation of spiral viscous fingering and the chemical reaction taking place between the two fluids.

  16. Contributions of individual reactive biogenic volatile organic compounds to organic nitrates above a mixed forest

    NASA Astrophysics Data System (ADS)

    Pratt, K. A.; Mielke, L. H.; Shepson, P. B.; Bryan, A. M.; Steiner, A. L.; Ortega, J.; Daly, R.; Helmig, D.; Vogel, C. S.; Griffith, S.; Dusanter, S.; Stevens, P. S.; Alaghmand, M.

    2012-11-01

    Biogenic volatile organic compounds (BVOCs) can react in the atmosphere to form organic nitrates, which serve as NOx (NO + NO2) reservoirs, impacting ozone and secondary organic aerosol production, the oxidative capacity of the atmosphere, and nitrogen availability to ecosystems. To examine the contributions of biogenic emissions and the formation and fate of organic nitrates in a forest environment, we simulated the oxidation of 57 individual BVOCs emitted from a rural mixed forest in northern Michigan. Key BVOC-oxidant reactions were identified for future laboratory and field investigations into reaction rate constants, yields, and speciation of oxidation products. Of the total simulated organic nitrates, monoterpenes contributed ~70% in the early morning at ~12 m above the forest canopy when isoprene emissions were low. In the afternoon, when vertical mixing and isoprene nitrate production were highest, the simulated contribution of isoprene-derived organic nitrates was greater than 90% at all altitudes, with the concentration of secondary isoprene nitrates increasing with altitude. Notably, reaction of isoprene with NO3 leading to isoprene nitrate formation was found to be significant (~8% of primary organic nitrate production) during the daytime, and monoterpene reactions with NO3 were simulated to comprise up to ~83% of primary organic nitrate production at night. Lastly, forest succession, wherein aspen trees are being replaced by pine and maple trees, was predicted to lead to increased afternoon concentrations of monoterpene-derived organic nitrates. This further underscores the need to understand the formation and fate of these species, which have different chemical pathways and oxidation products compared to isoprene-derived organic nitrates and can lead to secondary organic aerosol formation.

  17. Effects of a combined Diesel particle filter-DeNOx system (DPN) on reactive nitrogen compounds emissions: a parameter study.

    PubMed

    Heeb, Norbert V; Haag, Regula; Seiler, Cornelia; Schmid, Peter; Zennegg, Markus; Wichser, Adrian; Ulrich, Andrea; Honegger, Peter; Zeyer, Kerstin; Emmenegger, Lukas; Zimmerli, Yan; Czerwinski, Jan; Kasper, Markus; Mayer, Andreas

    2012-12-18

    The impact of a combined diesel particle filter-deNO(x) system (DPN) on emissions of reactive nitrogen compounds (RNCs) was studied varying the urea feed factor (α), temperature, and residence time, which are key parameters of the deNO(x) process. The DPN consisted of a platinum-coated cordierite filter and a vanadia-based deNO(x) catalyst supporting selective catalytic reduction (SCR) chemistry. Ammonia (NH₃) is produced in situ from thermolysis of urea and hydrolysis of isocyanic acid (HNCO). HNCO and NH₃ are both toxic and highly reactive intermediates. The deNO(x) system was only part-time active in the ISO8178/4 C1cycle. Urea injection was stopped and restarted twice. Mean NO and NO₂ conversion efficiencies were 80%, 95%, 97% and 43%, 87%, 99%, respectively, for α = 0.8, 1.0, and 1.2. HNCO emissions increased from 0.028 g/h engine-out to 0.18, 0.25, and 0.26 g/h at α = 0.8, 1.0, and 1.2, whereas NH₃ emissions increased from <0.045 to 0.12, 1.82, and 12.8 g/h with maxima at highest temperatures and shortest residence times. Most HNCO is released at intermediate residence times (0.2-0.3 s) and temperatures (300-400 °C). Total RNC efficiencies are highest at α = 1.0, when comparable amounts of reduced and oxidized compounds are released. The DPN represents the most advanced system studied so far under the VERT protocol achieving high conversion efficiencies for particles, NO, NO₂, CO, and hydrocarbons. However, we observed a trade-off between deNO(x) efficiency and secondary emissions. Therefore, it is important to adopt such DPN technology to specific application conditions to take advantage of reduced NO(x) and particle emissions while avoiding NH₃ and HNCO slip. PMID:23214996

  18. Safe Finger Tourniquet--Ideas.

    PubMed

    Wei, Lin-Gwei; Chen, Chieh-Feng; Hwang, Chun-Yuan; Chang, Chiung-Wen; Chiu, Wen-Kuan; Li, Chun-Chang; Wang, Hsian-Jenn

    2016-03-01

    Tourniquets are often needed for optimized phalangeal surgeries. However, few surgeons forget to remove them and caused ischemic injuries. We have a modified method to create a safe finger tourniquet for short duration finger surgeries, which can avoid such tragedy. It is done by donning a glove, cutting the tip of the glove over the finger of interest, and rolling the glove finger to the base. From 2010 to 2013, approximately 54 patients underwent digital surgical procedures with our safe finger tourniquet. Because the glove cannot be forgotten to be removed, the tourniquet must be released and removed. This is a simple and efficient way to apply a safe finger tourniquet by using hand rubber glove for a short-term bloodless finger surgery and can achieve an excellent surgical result. PMID:26855166

  19. New Class of Hydrido Iron(II) Compounds with cis-Reactive Sites: Combination of Iron and Diphosphinodithio Ligand.

    PubMed

    Liu, Jianguo; Zhang, Fanjun; Zhang, Ailing; Tong, Qingxiao; Tung, Chen-Ho; Wang, Wenguang

    2016-08-19

    The cationic complex [Fe(P2 S2 )(NCMe)2 ](2+) (P2 S2 =(Ph2 PC6 H4 CH2 S)2 (C2 H4 ) ([1(NCMe)2 ](2+) )), with two MeCN ligands in a cis orientation, was synthesized and characterized. The MeCN ligand in [1(NCMe)2 ](2+) undergoes further substitution by a hydride ligand or CO to give iron(II) hydrides [H1(NCMe)](+) , [H1H](0) , and [H1(CO)](+) . The order of reactivity of the hydrides was [H1H](0) >[H1(NCMe)](+) >[H1(CO)](+) , and was illustrated by their reactions toward protic acids, the organic cation of 10-methylacridinium (MeAcr(+) ) as a hydride acceptor, and intermolecular hydride transfer reactions among these ferrous compounds. For example, MeAcr(+) was reduced initially by a one-electron transfer process from [H1H](0) , resulting in competing reactions of MeAcr(.) dimerization, hydrogen atom transfer from [H1H](+) to MeAcr(.) , and decomposition of [H1H](+) . MeAcrH was produced in excellent yields through a single-step H(-) transfer from [H1(NCMe)](+) to MeAcr(+) , but [H1(CO)](+) was inactive toward MeAcr(+) . PMID:27362661

  20. An automated analyzer to measure surface-atmosphere exchange fluxes of water soluble inorganic aerosol compounds and reactive trace gases.

    PubMed

    Thomas, Rick M; Trebs, Ivonne; Otjes, René; Jongejan, Piet A C; Ten Brink, Harry; Phillips, Gavin; Kortner, Michael; Meixner, Franz X; Nemitz, Eiko

    2009-03-01

    Here, we present a new automated instrument for semicontinuous gradient measurements of water-soluble reactive trace gas species (NH3, HNO3, HONO, HCl, and SO2) and their related aerosol compounds (NH4+, NO3-, Cl-, SO4(2-)). Gas and aerosol samples are collected simultaneously at two heights using rotating wet-annular denuders and steam-jet aerosol collectors, respectively. Online (real-time) analysis using ion chromatography (IC) for anions and flow injection analysis (FIA) for NH4+ and NH3 provide a half-hourly averaged gas and aerosol gradients within each hour. Through the use of syringe pumps, IC preconcentration columns, and high-quality purified water, the system achieves detection limits (3sigma-definition) under field conditions of typically: 136/207,135/114, 29/ 22,119/92, and 189/159 ng m(-3) for NH3/NH4+, HNO3/NO3-, HONO/ NO2-, HCl/Cl- and SO2/SO4(2-), respectively. The instrument demonstrates very good linearity and accuracy for liquid and selected gas phase calibrations over typical ambient concentration ranges. As shown by examples from field experiments, the instrument provides sufficient precision (3-9%), even at low ambient concentrations, to resolve vertical gradients and calculate surface-atmosphere exchange fluxes undertypical meteorological conditions of the atmospheric surface layer using the aerodynamic gradient technique. PMID:19350912

  1. Newly synthesized bis-benzimidazole compound 8 induces apoptosis, autophagy and reactive oxygen species generation in HeLa cells.

    PubMed

    Chu, Naying; Yao, Guodong; Liu, Yuan; Cheng, Maosheng; Ikejima, Takashi

    2016-09-01

    Compound 8 (C8) is a newly synthesized bis-benzimidazole derivative and exerts significant anti-tumor activity in vitro. Previous studies demonstrated that C8 induced apoptosis and autophagy in human promyelocytic leukemia HL60 cells. However, cytotoxicity study on human peripheral blood mononuclear cells (hPBMC) showed that C8 exhibited less toxicity in normal cells. In this study, the molecular mechanism of C8 on human cervical carcinoma HeLa cells was investigated. The results showed that C8 inhibited the growth of HeLa cells and triggered both apoptotic and autophagic cell death. Subsequent experiment also indicated that reactive oxygen species (ROS) generation was induced in C8-treated HeLa cells. Since ROS scavenger decreased the ratio of apoptotic and autophagic cells, ROS generation contributed to C8-induced apoptosis and autophagy. Furthermore, inhibitors of apoptosis and autophagy also reduced ROS generation, respectively. Autophagy inhibition increased cell growth compared to C8-treated group and attenuated apoptotic cell death, indicating that C8-induced autophagy promoted apoptosis for cell death. However, the percentage of autophagic cells was enhanced when limiting apoptosis process. Taken together, C8 induced ROS-mediated apoptosis and autophagy in HeLa cells, autophagy promoted apoptosis but the former was antagonized by the latter. The data also gave us a new perspective on the anti-tumor effect of C8. PMID:27497983

  2. Viscous fingering with chemical reaction: effect of in-situ production of surfactants

    NASA Astrophysics Data System (ADS)

    Fernandez, Juan; Homsy, G. M.

    2003-04-01

    Viscous fingering experiments are performed in a radial Hele-Shaw cell for a liquid liquid system in the presence of a well-characterized interfacial reaction capable of changing the surface tension on the time scale of the experiments. The reaction is a neutralization of a fatty acid by an alkaline material to form a surfactant, which exhibits first-order kinetics for the surface tension as a function of time. The experiments are carried out for capillary numbers, Ca, high enough for the fingering to always be in the fractal regime, and for a wide range of Damköhler numbers, Da. The fingers are typically wider in the presence of the chemical reaction than the non-reactive case. We observe two different-behaviours of the reactive fingering patterns. For intermediate values of Da, 0.5 < Da < 4, the fractal dimension d_{f} is higher than the classical value measured for the non-reactive fingering patterns and reaches a maximum of about 1.9. For both small (Da < 0.5) and high Da (Da > 4), the reactive fingering patterns are similar to the fingers with no reaction: the fractal dimension is found to be the same for both systems. These effects are consistent with the hypothesis that Marangoni stresses are present and produce wider fingers.

  3. Reactive nitrogen compounds (RNCs) in exhaust of advanced PM-NO x abatement technologies for future diesel applications

    NASA Astrophysics Data System (ADS)

    Heeb, Norbert V.; Zimmerli, Yan; Czerwinski, Jan; Schmid, Peter; Zennegg, Markus; Haag, Regula; Seiler, Cornelia; Wichser, Adrian; Ulrich, Andrea; Honegger, Peter; Zeyer, Kerstin; Emmenegger, Lukas; Mosimann, Thomas; Kasper, Markus; Mayer, Andreas

    2011-06-01

    Long-term exposure to increased levels of reactive nitrogen compounds (RNCs) and particulate matter (PM) affect human health. Many cities are currently not able to fulfill European air quality standards for these critical pollutants. Meanwhile, promising new abatement technologies such as diesel particle filters (DPFs) and selective catalytic reduction (SCR) catalysts are developed to reduce PM and RNC emissions. Herein, effects of a urea-based SCR system on RNC emissions are discussed and we quantified the highly reactive intermediates isocyanic acid (HNCO) and ammonia (NH 3), both potential secondary pollutants of the urea-based SCR chemistry. A diesel engine (3.0 L, 100 kW), operated in the ISO 8178/4 C1, cycle was used as test platform. A V 2O 5-based SCR catalyst was either applied as such or down-stream of a high oxidation potential-DPF (hox-DPF). With active SCR, nitric oxide (NO) and nitrogen dioxide (NO 2) conversion efficiencies of 0.86-0.94 and 0.86-0.99 were obtained. On the other hand, mean HNCO and NH 3 emissions increased to 240-280 and 1800-1900 mg h -1. On a molar basis, HNCO accounted for 0.8-1.4% and NH 3 for 14-25% of the emitted RNCs. On roads, SCR systems will partly be inactive when exhaust temperatures drop below 220 °C. The system was active only during 75% of the test cycle, and urea dosing was stopped and restarted several times. Consequently, NO conversion stopped but interestingly, NO 2 was still converted. Such light-off and shutdown events are frequent in urban driving, compromising the overall deNO x efficiency. Another important effect of the SCR technology is illustrated by the NH 3/NO 2 ratio, which was >1 with active SCR, indicating that exhaust is basic rather than acidic after the SCR catalyst. Under these conditions, isocyanic acid is stable. The widespread use of various converter technologies already affected RNC release. Diesel oxidation catalysts (DOCs) and hox-DPFs increased NO 2 emissions, three-way catalysts (TWCs

  4. Reactivity of selenium-containing compounds with myeloperoxidase-derived chlorinating oxidants: Second-order rate constants and implications for biological damage.

    PubMed

    Carroll, Luke; Pattison, David I; Fu, Shanlin; Schiesser, Carl H; Davies, Michael J; Hawkins, Clare L

    2015-07-01

    Hypochlorous acid (HOCl) and N-chloramines are produced by myeloperoxidase (MPO) as part of the immune response to destroy invading pathogens. However, MPO also plays a detrimental role in inflammatory pathologies, including atherosclerosis, as inappropriate production of oxidants, including HOCl and N-chloramines, causes damage to host tissue. Low molecular mass thiol compounds, including glutathione (GSH) and methionine (Met), have demonstrated efficacy in scavenging MPO-derived oxidants, which prevents oxidative damage in vitro and ex vivo. Selenium species typically have greater reactivity toward oxidants compared to the analogous sulfur compounds, and are known to be efficient scavengers of HOCl and other hypohalous acids produced by MPO. In this study, we examined the efficacy of a number of sulfur and selenium compounds to scavenge a range of biologically relevant N-chloramines and oxidants produced by both isolated MPO and activated neutrophils and characterized the resulting selenium-derived oxidation products in each case. A dose-dependent decrease in the concentration of each N-chloramine was observed on addition of the sulfur compounds (cysteine, methionine) and selenium compounds (selenomethionine, methylselenocysteine, 1,4-anhydro-4-seleno-L-talitol, 1,5-anhydro-5-selenogulitol) studied. In general, selenomethionine was the most reactive with N-chloramines (k2 0.8-3.4×10(3)M(-1) s(-1)) with 1,5-anhydro-5-selenogulitol and 1,4-anhydro-4-seleno-L-talitol (k2 1.1-6.8×10(2)M(-1) s(-1)) showing lower reactivity. This resulted in the formation of the respective selenoxides as the primary oxidation products. The selenium compounds demonstrated greater ability to remove protein N-chloramines compared to the analogous sulfur compounds. These reactions may have implications for preventing cellular damage in vivo, particularly under chronic inflammatory conditions. PMID:25841785

  5. Cross-reactivity of antibodies with phenolic compounds in pistachios during quantification of ochratoxin A by commercial enzyme-linked immunosorbent assay kits.

    PubMed

    Lee, Hyun Jung; Meldrum, Alexander D; Rivera, Nicholas; Ryu, Dojin

    2014-10-01

    Ochratoxin A (OTA), a nephrotoxic mycotoxin, naturally occurs in wide range of agricultural commodities. Typical screening of OTA involves various enzyme-linked immunosorbent assay (ELISA) methods. Pistachio (Pistacia vera L.) is a rich source of phenolic compounds that may result in a false positive due to structural similarities to OTA. The present study investigated the cross-reactivity profiles of phenolic compounds using two commercial ELISA test kits. High-performance liquid chromatography was used to confirm the concentration of OTA in the pistachio samples and compared with the results obtained from ELISA. When the degree of interaction and 50 % inhibitory concentration of phenolic compounds were determined, the cross-reactivity showed a pattern similar to that observed with the commercial ELSIA kits, although quantitatively different. In addition, the degree of interaction increased with the increasing concentration of phenolic compounds. The ELISA value had stronger correlations with the content of total phenolic compound, gallic acid, and catechin (R(2) = 0.757, 0.732, and 0.729, respectively) compared with epicatechin (R(2) = 0.590). These results suggest that phenolic compounds in pistachio skins may cross-react with the OTA antibody and lead to a false positive or to an overestimation of OTA concentration in ELISA-based tests. PMID:25285493

  6. Finger Forces in Clarinet Playing

    PubMed Central

    Hofmann, Alex; Goebl, Werner

    2016-01-01

    Clarinettists close and open multiple tone holes to alter the pitch of the tones. Their fingering technique must be fast, precise, and coordinated with the tongue articulation. In this empirical study, finger force profiles and tongue techniques of clarinet students (N = 17) and professional clarinettists (N = 6) were investigated under controlled performance conditions. First, in an expressive-performance task, eight selected excerpts from the first Weber Concerto were performed. These excerpts were chosen to fit in a 2 × 2 × 2 design (register: low–high; tempo: slow–fast, dynamics: soft–loud). There was an additional condition controlled by the experimenter, which determined the expression levels (low–high) of the performers. Second, a technical-exercise task, an isochronous 23-tone melody was designed that required different effectors to produce the sequence (finger-only, tongue-only, combined tongue-finger actions). The melody was performed in three tempo conditions (slow, medium, fast) in a synchronization-continuation paradigm. Participants played on a sensor-equipped Viennese clarinet, which tracked finger forces and reed oscillations simultaneously. From the data, average finger force (Fmean) and peak force (Fmax) were calculated. The overall finger forces were low (Fmean = 1.17 N, Fmax = 3.05 N) compared to those on other musical instruments (e.g., guitar). Participants applied the largest finger forces during the high expression level performance conditions (Fmean = 1.21 N). For the technical exercise task, timing and articulation information were extracted from the reed signal. Here, the timing precision of the fingers deteriorated the timing precision of the tongue for combined tongue-finger actions, especially for faster tempi. Although individual finger force profiles were overlapping, the group of professional players applied less finger force overall (Fmean = 0.54 N). Such sensor instruments provide useful insights into player

  7. Robotic Finger Assembly

    NASA Technical Reports Server (NTRS)

    Ihrke, Chris A. (Inventor); Bridgwater, Lyndon (Inventor); Diftler, Myron A. (Inventor); Linn, Douglas M. (Inventor); Platt, Robert (Inventor); Hargrave, Brian (Inventor); Askew, Scott R. (Inventor); Valvo, Michael C. (Inventor)

    2013-01-01

    A robotic hand includes a finger with first, second, and third phalanges. A first joint rotatably connects the first phalange to a base structure. A second joint rotatably connects the first phalange to the second phalange. A third joint rotatably connects the third phalange to the second phalange. The second joint and the third joint are kinematically linked such that the position of the third phalange with respect to the second phalange is determined by the position of the second phalange with respect to the first phalange.

  8. Robotic Finger Assembly

    NASA Technical Reports Server (NTRS)

    Ihrke, Chris A. (Inventor); Bridgwater, Lyndon (Inventor); Diftler, Myron A. (Inventor); Linn, Douglas Martin (Inventor); Platt, Robert J., Jr. (Inventor); Hargrave, Brian (Inventor); Askew, Scott R. (Inventor); Valvo, Michael C. (Inventor)

    2014-01-01

    A robotic hand includes a finger with first, second, and third phalanges. A first joint rotatably connects the first phalange to a base structure. A second joint rotatably connects the first phalange to the second phalange. A third joint rotatably connects the third phalange to the second phalange. The second joint and the third joint are kinematically linked such that the position of the third phalange with respect to the second phalange is determined by the position of the second phalange with respect to the first phalange.

  9. Gert Finger Becomes Emeritus Physicist

    NASA Astrophysics Data System (ADS)

    de Zeeuw, T.; Lucuix, C.; Péron, M.

    2016-03-01

    Gert Finger has retired after almost 33 years service and he has been made the first Emeritus Physicist at ESO. An appreciation of some of his many achievements in the development of infrared instrumentation and detector controllers is given. A retirement party for Gert Finger was held in February 2016.

  10. Prototype Systems Containing Human Cytochrome P450 for High-Throughput Real-Time Detection of DNA Damage by Compounds That Form DNA-Reactive Metabolites.

    PubMed

    Brito Palma, Bernardo; Fisher, Charles W; Rueff, José; Kranendonk, Michel

    2016-05-16

    The formation of reactive metabolites through biotransformation is the suspected cause of many adverse drug reactions. Testing for the propensity of a drug to form reactive metabolites has increasingly become an integral part of lead-optimization strategy in drug discovery. DNA reactivity is one undesirable facet of a drug or its metabolites and can lead to increased risk of cancer and reproductive toxicity. Many drugs are metabolized by cytochromes P450 in the liver and other tissues, and these reactions can generate hard electrophiles. These hard electrophilic reactive metabolites may react with DNA and may be detected in standard in vitro genotoxicity assays; however, the majority of these assays fall short due to the use of animal-derived organ extracts that inadequately represent human metabolism. The current study describes the development of bacterial systems that efficiently detect DNA-damaging electrophilic reactive metabolites generated by human P450 biotransformation. These assays use a GFP reporter system that detects DNA damage through induction of the SOS response and a GFP reporter to control for cytotoxicity. Two human CYP1A2-competent prototypes presented here have appropriate characteristics for the detection of DNA-damaging reactive metabolites in a high-throughput manner. The advantages of this approach include a short assay time (120-180 min) with real-time measurement, sensitivity to small amounts of compound, and adaptability to a microplate format. These systems are suitable for high-throughput assays and can serve as prototypes for the development of future enhanced versions. PMID:27031942

  11. Comparing the potency of chemicals with multiple modes of action in aquatic toxicology: Acute toxicity due to narcosis versus reactive toxicity of acrylic compounds

    SciTech Connect

    Freidig, A.P.; Verhaar, H.J.M.; Hermens, J.L.M.

    1999-09-01

    A series of acrylates and methacrylates was used to illustrate a strategy to compare the importance of two modes of action (MOA) and thereby identify the predominant cause of acute fish toxicity. Acrylic compounds are known to be Michael acceptors and may therefore react with glutathione (GSH), causing GSH-depletion in vivo (reactive mechanism). On the other hand, acrylates may also act by a nonspecific mechanism (narcosis). The following two, physiologically meaningful parameters were calculated in order to estimate the contribution of these two mechanisms to the overall acute toxicity: (i) a lipid normalized body burden for narcosis and (ii) the potential degree of GSH depletion by chemical reactivity. The degree of GSH depletion was found to be related to the product of the reactivity toward GSH and the exposure concentration. This model was validated with four model compounds and an in vivo study. For both MOA, toxic ratios were calculated and compared for all chemicals in the series. The approach enables the comparison of the contribution to toxicity of chemicals with more than on MOA.

  12. Ozone reactivity of biogenic volatile organic compounds emitted from the four dominant tree species at PROPHET - CABINEX

    NASA Astrophysics Data System (ADS)

    Helmig, D.; Daly, R.; Bertman, S. B.

    2010-12-01

    A number of recent studies on biogenic volatile organic emissions (BVOC) released in the forest atmosphere have pointed out that identified emissions can not account for the entire chemical reactivity seen in the forest atmosphere. During the 2009 and 2010 Community Atmosphere-Biosphere Interactions Experiment (CABINEX) at the University of Michigan Biological Station (UMBS) PROPHET site BVOC emissions and their reactivity with ozone were studied with a newly developed ozone reactivity instrument. Experiments were conducted on the tree species red oak, white pine, quaking aspen, and red maple, representing ~ 87% of the canopy leaf area index at this site. BVOC emissions were sampled from a branch bag enclosure, mixed with ozone-enriched air, and directed through a series of reaction vessels. A differential ozone monitor was used to determine the reaction rate with ozone while emissions were being purged through the reaction vessel. BVOC in the outflow of the bag enclosure were also determined with a field gas chromatography-mass spectrometry instrument, and by collection on adsorbent cartridges with subsequent analysis in our Boulder laboratory. Experiments were performed over several days to capture emission changes under varying ambient temperature and light conditions. The ozone reactivity showed distinct diurnal cycles and a tight correlation with leaf temperature, typically maximizing during mid day to afternoon. Furthermore, the four tree species investigated displayed a distinctly different behavior, with emissions from the one coniferous tree species (white pine) exhibiting the overall highest ozone reactivity signal.

  13. Fingering Instabilities in Dewetting Nanofluids

    NASA Astrophysics Data System (ADS)

    Pauliac-Vaujour, E.; Stannard, A.; Martin, C. P.; Blunt, M. O.; Notingher, I.; Moriarty, P. J.; Vancea, I.; Thiele, U.

    2008-05-01

    The growth of fingering patterns in dewetting nanofluids (colloidal solutions of thiol-passivated gold nanoparticles) has been followed in real time using contrast-enhanced video microscopy. The fingering instability on which we focus here arises from evaporatively driven nucleation and growth in a nanoscopically thin precursor solvent film behind the macroscopic contact line. We find that well-developed isotropic fingering structures only form for a narrow range of experimental parameters. Numerical simulations, based on a modification of the Monte Carlo approach introduced by Rabani et al. [Nature (London)NATUAS0028-0836 426, 271 (2003)10.1038/nature02087], reproduce the patterns we observe experimentally.

  14. Fingering instabilities in dewetting nanofluids.

    PubMed

    Pauliac-Vaujour, E; Stannard, A; Martin, C P; Blunt, M O; Notingher, I; Moriarty, P J; Vancea, I; Thiele, U

    2008-05-01

    The growth of fingering patterns in dewetting nanofluids (colloidal solutions of thiol-passivated gold nanoparticles) has been followed in real time using contrast-enhanced video microscopy. The fingering instability on which we focus here arises from evaporatively driven nucleation and growth in a nanoscopically thin precursor solvent film behind the macroscopic contact line. We find that well-developed isotropic fingering structures only form for a narrow range of experimental parameters. Numerical simulations, based on a modification of the Monte Carlo approach introduced by Rabani et al. [Nature (London) 426, 271 (2003)10.1038/nature02087], reproduce the patterns we observe experimentally. PMID:18518311

  15. Finger-Circumference-Measuring Device

    NASA Technical Reports Server (NTRS)

    Le, Suy

    1995-01-01

    Easy-to-use device quickly measures circumference of finger (including thumb) on human hand. Includes polytetrafluoroethylene band 1/8 in. wide, bent into loop and attached to tab that slides on scale graduated in millimeters. Sliding tab preloaded with constant-force tension spring, which pulls tab toward closure of loop. Designed to facilitate measurements at various points along fingers to obtain data for studies of volumetric changes of fingers in microgravity. Also used in normal Earth gravity studies of growth and in assessment of diseases like arthritis.

  16. Finger Forces in Clarinet Playing.

    PubMed

    Hofmann, Alex; Goebl, Werner

    2016-01-01

    Clarinettists close and open multiple tone holes to alter the pitch of the tones. Their fingering technique must be fast, precise, and coordinated with the tongue articulation. In this empirical study, finger force profiles and tongue techniques of clarinet students (N = 17) and professional clarinettists (N = 6) were investigated under controlled performance conditions. First, in an expressive-performance task, eight selected excerpts from the first Weber Concerto were performed. These excerpts were chosen to fit in a 2 × 2 × 2 design (register: low-high; tempo: slow-fast, dynamics: soft-loud). There was an additional condition controlled by the experimenter, which determined the expression levels (low-high) of the performers. Second, a technical-exercise task, an isochronous 23-tone melody was designed that required different effectors to produce the sequence (finger-only, tongue-only, combined tongue-finger actions). The melody was performed in three tempo conditions (slow, medium, fast) in a synchronization-continuation paradigm. Participants played on a sensor-equipped Viennese clarinet, which tracked finger forces and reed oscillations simultaneously. From the data, average finger force (F mean ) and peak force (F max ) were calculated. The overall finger forces were low (F mean = 1.17 N, F max = 3.05 N) compared to those on other musical instruments (e.g., guitar). Participants applied the largest finger forces during the high expression level performance conditions (F mean = 1.21 N). For the technical exercise task, timing and articulation information were extracted from the reed signal. Here, the timing precision of the fingers deteriorated the timing precision of the tongue for combined tongue-finger actions, especially for faster tempi. Although individual finger force profiles were overlapping, the group of professional players applied less finger force overall (F mean = 0.54 N). Such sensor instruments provide useful insights into player

  17. Effects of crystal orientation and ferroelastic domain structure on the photochemical reactivity of BiVO4 and related compounds

    NASA Astrophysics Data System (ADS)

    Munprom, Ratiporn

    Bismuth vanadate, BiVO4, has been recognized for its high efficiency as a photoanode for water splitting. However, its performance is limited by photogenerated electron--hole recombination. Thus, researchers have attempted to modify BiVO4 to improve its performance. One strategy to improve charge separation is to utilize an internal field arising from surface termination differences. Previous studies concentrated on polygonal single crystals of BiVO4, providing limited information about the orientation-reactivity relationship. The current research focuses on polycrystalline BiVO4, which makes it possible to study the photochemical reactivity of all possible orientations and determine the complete orientation dependence of the photochemical reactivity of BiVO4. (Abstract shortened by UMI.).

  18. Rapid Diminution in the Level and Activity of DNA-Dependent Protein Kinase in Cancer Cells by a Reactive Nitro-Benzoxadiazole Compound

    PubMed Central

    Silva, Viviane A. O.; Lafont, Florian; Benhelli-Mokrani, Houda; Breton, Magali Le; Hulin, Philippe; Chabot, Thomas; Paris, François; Sakanyan, Vehary; Fleury, Fabrice

    2016-01-01

    The expression and activity of DNA-dependent protein kinase (DNA-PK) is related to DNA repair status in the response of cells to exogenous and endogenous factors. Recent studies indicate that Epidermal Growth Factor Receptor (EGFR) is involved in modulating DNA-PK. It has been shown that a compound 4-nitro-7-[(1-oxidopyridin-2-yl)sulfanyl]-2,1,3-benzoxadiazole (NSC), bearing a nitro-benzoxadiazole (NBD) scaffold, enhances tyrosine phosphorylation of EGFR and triggers downstream signaling pathways. Here, we studied the behavior of DNA-PK and other DNA repair proteins in prostate cancer cells exposed to compound NSC. We showed that both the expression and activity of DNA-PKcs (catalytic subunit of DNA-PK) rapidly decreased upon exposure of cells to the compound. The decline in DNA-PKcs was associated with enhanced protein ubiquitination, indicating the activation of cellular proteasome. However, pretreatment of cells with thioglycerol abolished the action of compound NSC and restored the level of DNA-PKcs. Moreover, the decreased level of DNA-PKcs was associated with the production of intracellular hydrogen peroxide by stable dimeric forms of Cu/Zn SOD1 induced by NSC. Our findings indicate that reactive oxygen species and electrophilic intermediates, generated and accumulated during the redox transformation of NBD compounds, are primarily responsible for the rapid modulation of DNA-PKcs functions in cancer cells. PMID:27187356

  19. Neural correlates of finger gnosis.

    PubMed

    Rusconi, Elena; Tamè, Luigi; Furlan, Michele; Haggard, Patrick; Demarchi, Gianpaolo; Adriani, Michela; Ferrari, Paolo; Braun, Christoph; Schwarzbach, Jens

    2014-07-01

    Neuropsychological studies have described patients with a selective impairment of finger identification in association with posterior parietal lesions. However, evidence of the role of these areas in finger gnosis from studies of the healthy human brain is still scarce. Here we used functional magnetic resonance imaging to identify the brain network engaged in a novel finger gnosis task, the intermanual in-between task (IIBT), in healthy participants. Several brain regions exhibited a stronger blood oxygenation level-dependent (BOLD) response in IIBT than in a control task that did not explicitly rely on finger gnosis but used identical stimuli and motor responses as the IIBT. The IIBT involved stronger signal in the left inferior parietal lobule (IPL), bilateral precuneus (PCN), bilateral premotor cortex, and left inferior frontal gyrus. In all regions, stimulation of nonhomologous fingers of the two hands elicited higher BOLD signal than stimulation of homologous fingers. Only in the left anteromedial IPL (a-mIPL) and left PCN did signal strength decrease parametrically from nonhomology, through partial homology, to total homology with stimulation delivered synchronously to the two hands. With asynchronous stimulation, the signal was stronger in the left a-mIPL than in any other region, possibly indicating retention of task-relevant information. We suggest that the left PCN may contribute a supporting visuospatial representation via its functional connection to the right PCN. The a-mIPL may instead provide the core substrate of an explicit bilateral body structure representation for the fingers that when disrupted can produce the typical symptoms of finger agnosia. PMID:24990921

  20. Reactivity of target compounds for chemical coal desulfurization. Technical report, 1 December 1993--28 February 1994

    SciTech Connect

    Buchanan, D.H.; Amin, M.; Cunningham, R.; Galyen, J.

    1994-06-01

    This project seeks to identify representative organosulfur compounds which are removed by coal desulfurization reactions. Demineralized coals from the Illinois Basin Coal Sample Program are solvent extracted and the extracts fractionated to separate and concentrate organosulfur compounds for analysis by Gas Chromatography/Mass Spectroscopy. After sulfur compounds are characterized, the parent extracts will be subjected to reactions previously shown to reduce the organic sulfur content of Illinois coals, fractionated and again analyzed for organosulfur content to determine which compounds reacted during the chemical treatment. The original coal will be subjected to chemical desulfurization, extraction, fractionation and analysis in order to correlate changes in organic sulfur content of the coal with reactions of specific sulfur compounds. These compounds can thus be reliably considered as target molecules for the next generation of desulfurization processes. During this quarter, work continued on developing efficient methods to isolate and analyze sulfur-rich coal extract fractions by GC/MS. Since only relatively non-polar compounds can be analyzed, pyridine extracts must be fractionated. Direct extraction of several coals with toluene is quicker but did not give as much toluene soluble material as fractionation of pyridine extracts and is thus not suitable for preparation of representative analytical samples. The authors observe that most IBC sample program coals contain elemental sulfur due to oxidation of pyrite. There is less elemental sulfur in IBC-101 than in other Herrin coals. This coal was washed in a preparation plant to reduce pyrite concentration. Since elemental sulfur slowly reacts to produce organosulfur compounds in coal during storage or handling, this suggests that early removal of pyrite can reduce formation of these hard to remove compounds.

  1. LGIT In Vitro Latency Model in Primary and T Cell Lines to Test HIV-1 Reactivation Compounds.

    PubMed

    Jung, Ulrike; Takahashi, Mayumi; Rossi, John J; Burnett, John C

    2016-01-01

    Persistent latent HIV-1 reservoirs pose a major barrier for combinatorial antiretroviral therapy (cART) to achieve eradication of the virus. A variety of mechanisms likely contribute to HIV-1 persistence, including establishment of post-integration latency in resting CD4+ T-lymphocytes, the proliferation of these latently infected cells, and the induced or spontaneous reactivation of latent virus. To elucidate the mechanisms of latency and to investigate therapeutic strategies for reactivating and purging the latent reservoir, investigators have developed in vitro models of HIV-1 latency using primary CD4+ T-lymphocytes and CD4+ T-cell lines. Several types of in vitro latency models range from replication-competent to single-round, replication-deficient viruses exhibiting different degrees of viral genomic deletion. Working under the hypothesis that HIV-1 post-integration latency is directly linked to HIV-1 promoter activity, which can be obscured by additional proteins expressed during replication, we focus here on the creation of latently infected primary human T-cells and cell lines through the single-round, replication deficient HIV-1 LGIT model. In this model the long terminal repeat (LTR) of the HIV-1 virus drives a cassette of GFP-IRES-Tat that allows testing of reactivating components and initiates a positive feedback loop through Tat expression. PMID:26714717

  2. Multi-finger interaction during involuntary and voluntary single finger force changes

    PubMed Central

    Martin, J.R.; Zatsiorsky, V.M.; Latash, M.L.

    2011-01-01

    Two types of finger interaction are characterized by positive co-variation (enslaving) or negative co-variation (error compensation) of finger forces. Enslaving reflects mechanical and neural connections among fingers, while error compensation results from synergic control of fingers to stabilize their net output. Involuntary and voluntary force changes by a finger were used to explore these patterns. We hypothesized that synergic mechanisms will dominate during involuntary force changes, while enslaving will dominate during voluntary finger force changes. Subjects pressed with all four fingers to match a target force that was 10% of their maximum voluntary contraction (MVC). One of the fingers was unexpectedly raised 5.0 mm at a speed of 30.0 mm/s. During finger raising the subject was instructed “not to intervene voluntarily”. After the finger was passively lifted and a new steady-state achieved, subjects pressed down with the lifted finger, producing a pulse of force voluntarily. The data were analyzed in terms of finger forces and finger modes (hypothetical commands to fingers reflecting their intended involvement). The target finger showed an increase in force during both phases. In the involuntary phase, the target finger force changes ranged between 10.71 ± 1.89% MVC (I-finger) and 16.60 ± 2.26% MVC (L-finger). Generally, non-target fingers displayed a force decrease with a maximum amplitude of −1.49 ± 0.43% MVC (L-finger). Thus, during the involuntary phase, error compensation was observed – non-lifted fingers showed a decrease in force (as well as in mode magnitude). During the voluntary phase, enslaving was observed – non-target fingers showed an increase in force and only minor changes in mode magnitude. The average change in force of non-target fingers ranged from 21.83 ± 4.47% MVC for R-finger (M-finger task) to 0.71 ± 1.10 % MVC for L-finger (I-finger task). The average change in mode of non-target fingers was between −7.34 ± 19

  3. Clay for Little Fingers.

    ERIC Educational Resources Information Center

    Koster, Joan Bouza

    1999-01-01

    Discusses the renewed interest in clay as a modeling compound in early childhood programs; describes the nature of clay and presents a working vocabulary. Suggests methods of working with clay, including introducing clay to children, discovering its uses, clean up, firing clay, and finishing baked clay. Includes activity suggestions and…

  4. Stability, Reactivity, and Constituent Interaction in TiSe2-Based Metastable Misfit Layer Compounds Synthesized from Designed Amorphous Precursors

    NASA Astrophysics Data System (ADS)

    Merrill, Devin R.

    A series of intergrowth compounds with the basic formula [(MSe) 1+delta]m(TiSe2)n are reported. The compounds are prepared from modulated elemental reactants and display interesting structural and electronic behavior. Section 1 of this dissertation outlines initial attempts to characterize constituent interaction. The first member of the SnSe based subclass is reported and displays the highest Seebeck coefficient of any m = n = 1 compound reported to date, and a surprising amount of order is observed, compared to previously reported compounds. With properly established deposition parameters, the synthesis was extended to included the m = 2-4 compounds. These compounds display interesting electronic behavior that suggests the band structure shifts considerably as the SnSe block is expanded, affecting the interaction between the constituent layers. The first compound based on BiSe is then reported, suggesting that the Bi structure donates more conduction electrons to the band structure. Targeted substitution through kinetic control is the focus of Section 2, and a family of (PbxSn1-xSe)1+deltaTiSe 2 is reported over the entire range of x, even though a miscibility gap exists in the bulk PbxSn1-xSe system. The resulting alloyed intergrowth compounds also display equal or higher mobility than the end members, suggesting modulation doping could be used to affect transport properties. As a proof of principle, the analogous system based on a Bi xSn1-xSe constituent was prepared to attempt to systematically affect carrier concentration. It was found that while carrier concentration can be controlled, the evolving structure affects the doping efficiency of the Bi atoms and mobility in the structure. Section 3 outlines attempts to form higher order TiSe2-based heterostructures and the important chemical considerations observed during the preparation of these materials. The 3 component systems in the Pb-Sn-Ti-Se system can be formed at low temperature, with SnSe2 rather than

  5. Experimental Evaluation of Gas-Phase Transport and Reactivity of Two Organophosphate Compounds in Unsaturated Porous Media

    NASA Astrophysics Data System (ADS)

    Rockhold, M.; Johnson, T.; Szecsody, J.; McKinley, J.; Blake, T.; Wietsma, T.; Covert, M.; Oostrom, M.

    2008-12-01

    An experimental study was undertaken to evaluate the feasibility of using organophosphate compounds that can be transported in the gas phase as a source of phosphorus for mineral formation (e.g. apatite) and contaminant sequestration in deep unsaturated zones. Previous work by others with gaseous phosphate compounds utilized triethyl phosphate (TEP) for bioremediation. In the current study we used both TEP and another chemically similar compound, dimethyl methylphosphonate (DMMP) that has a higher saturation vapor pressure. Batch abiotic degradation experiments in aqueous solutions with and without sediment (in both oxic and reducing conditions) indicate that both TEP and DMMP are very recalcitrant. Slow conversion from organic-to inorganic-P forms occurred (<5% in 3 months) under high temperature (80° C) and highly alkaline pH conditions. TEP and DMMP biodegradation to PO4 was found to be minimal over a similar time period using concentrated solutions of in situ microbes with no other growth substrates present. Gas transport studies using FTIR spectroscopy show that these compounds also adsorb very strongly to unsaturated sediments from the Hanford Site, to the extent that no breakthrough was observed even after >1000 pore volumes of gas exchange and complete dessication of the sediments. Methanol production was observed during the gas transport experiments, indicating that the lack of observed breakthrough of the original organophosphate compounds was attributable to both adsorption and reaction processes. FTIR reflection spectroscopy and microprobe analyses were performed to identify and quantify adsorbed species and possible mineral formation.

  6. Evaluation of nutraceutical and antinutritional properties in barnyard and finger millet varieties grown in Himalayan region.

    PubMed

    Panwar, Priyankar; Dubey, Ashutosh; Verma, A K

    2016-06-01

    Five elite varieties of barnyard (Echinochloa frumentacea) and finger (Eleusine coracana) growing at northwestern Himalaya were investigated for nutraceutical and antinutritional properties. Barnyard millet contained higher amount of crude fiber, total dietary fiber, tryptophan content, total carotenoids, α-tocopherol compared to the finger millet whereas the finger millet contains higher amount of methionine and ascorbic acid as compared to the barnyard millet. The secondary metabolites of biological functions were analyzed and found that barnyard millet contained the higher amount of polyphenols, tannins and ortho-dihydroxy phenol content compared to finger millet. Among antinutitional compounds barnyard millet contained lower phytic acid content compare to finger millet whereas no significant difference in trypsin inhibition activity of barnyard millet and finger millet varieties were found. Barnyard millet contained higher acid phosphatase, α-galactosidase and α-amylase inhibitor activity compared to finger millet. Finger millet seeds contained about 10-13 folds higher calcium content and double amount of manganese content in comparison to barnyard millet seeds. Present study suggests that barnyard millet varieties studied under present investigation were found nutritionally superior compared to finger millet varieties. PMID:27478234

  7. 6-Methyl 3-chromonyl 2,4-thiazolidinedione/2,4-imidazolidinedione/2-thioxo-imidazolidine-4-one compounds: novel scavengers of reactive oxygen species.

    PubMed

    Berczyński, Paweł; Duchnik, Ewa; Kruk, Irena; Piechowska, Teresa; Aboul-Enein, Hassan Y; Bozdağ-Dündar, Oya; Ceylan-Unlusoy, Meltem

    2014-06-01

    The benefits of antioxidants on human health are usually ascribed to their potential ability to remove reactive oxygen species providing protection against oxidative stress. In this paper the free radicals scavenging activities of nine 6-methyl 3-chromonyl derivatives (CMs) were evaluated for the first time by the chemiluminescence, electron paramagnetic resonance, spin trapping and 2,2-diphenyl-1-picrylhydrazyl (DPPH(•)) methods. The total antioxidant capacity was also measured using a ferric-ferrozine reagent. Compounds having a hydrogen atom at the N3-position of the β-ring were effective in quenching CL resulted from the KO2 /18-crown-6-ether system (a source of superoxide anion radical, O2•¯) in a dose-dependent manner over the range of 0.05-1 mmol/L [IC50 ranged from 0.353 (0.04) to 0.668 (0.05) mmol/L]. The examined compounds exhibited a significant scavenging effect towards hydroxyl radicals (HO(•) HO(•)), produced by the Fenton reaction, and this ranged from 24.0% to 61.0%, at the concentration of 2.5 mmol/L. Furthermore, the compounds examined were also found to inhibit DPPH(•) and this ranged from 51.9% to 97.4% at the same concentration. In addition, the use of the total antioxidant capacity assay confirmed that CM compounds are able to act as reductants. According to the present study, CM compounds showed effective in vitro free radical scavenging activity and may be considered as potential therapeutics to control diseases of oxidative stress-related etiology. PMID:23843284

  8. Disruption of focal adhesion kinase and p53 interaction with small molecule compound R2 reactivated p53 and blocked tumor growth

    PubMed Central

    2013-01-01

    Background Focal Adhesion Kinase (FAK) is a 125 kDa non-receptor kinase that plays a major role in cancer cell survival and metastasis. Methods We performed computer modeling of the p53 peptide containing the site of interaction with FAK, predicted the peptide structure and docked it into the three-dimensional structure of the N-terminal domain of FAK involved in the complex with p53. We screened small molecule compounds that targeted the site of the FAK-p53 interaction and identified compounds (called Roslins, or R compounds) docked in silico to this site. Results By different assays in isogenic HCT116p53+/+ and HCT116 p53-/- cells we identified a small molecule compound called Roslin 2 (R2) that bound FAK, disrupted the binding of FAK and p53 and decreased cancer cell viability and clonogenicity in a p53-dependent manner. In addition, dual-luciferase assays demonstrated that the R2 compound increased p53 transcriptional activity that was inhibited by FAK using p21, Mdm-2, and Bax-promoter targets. R2 also caused increased expression of p53 targets: p21, Mdm-2 and Bax proteins. Furthermore, R2 significantly decreased tumor growth, disrupted the complex of FAK and p53, and up-regulated p21 in HCT116 p53+/+ but not in HCT116 p53-/- xenografts in vivo. In addition, R2 sensitized HCT116p53+/+ cells to doxorubicin and 5-fluorouracil. Conclusions Thus, disruption of the FAK and p53 interaction with a novel small molecule reactivated p53 in cancer cells in vitro and in vivo and can be effectively used for development of FAK-p53 targeted cancer therapy approaches. PMID:23841915

  9. Fluid mixing from viscous fingering.

    PubMed

    Jha, Birendra; Cueto-Felgueroso, Luis; Juanes, Ruben

    2011-05-13

    Mixing efficiency at low Reynolds numbers can be enhanced by exploiting hydrodynamic instabilities that induce heterogeneity and disorder in the flow. The unstable displacement of fluids with different viscosities, or viscous fingering, provides a powerful mechanism to increase fluid-fluid interfacial area and enhance mixing. Here we describe the dissipative structure of miscible viscous fingering, and propose a two-equation model for the scalar variance and its dissipation rate. Our analysis predicts the optimum range of viscosity contrasts that, for a given Péclet number, maximizes interfacial area and minimizes mixing time. In the spirit of turbulence modeling, the proposed two-equation model permits upscaling dissipation due to fingering at unresolved scales. PMID:21668165

  10. Mesofluidic controlled robotic or prosthetic finger

    SciTech Connect

    Lind, Randall F; Jansen, John F; Love, Lonnie J

    2013-11-19

    A mesofluidic powered robotic and/or prosthetic finger joint includes a first finger section having at least one mesofluidic actuator in fluid communication with a first actuator, a second mesofluidic actuator in fluid communication with a second actuator and a second prosthetic finger section pivotally connected to the first finger section by a joint pivot, wherein the first actuator pivotally cooperates with the second finger to provide a first mechanical advantage relative to the joint point and wherein the second actuator pivotally cooperates with the second finger section to provide a second mechanical advantage relative to the joint point.

  11. Finger flexion does not contribute to ball speed in overarm throws.

    PubMed

    Hore, J; Watts, S; Martin, J

    1996-08-01

    The aim of this study was to determine whether, in overarm throws made by recreational ball players, the fingers undergo flexion movement before ball release and thereby contribute to the generation of ball speed. To obtain the high resolution needed to answer this question, the magnetic-field search-coil technique was used and the data were sampled at 1000 Hz. The subjects, who were either seated or were standing, threw tennis balls at different speeds at a target 3 m away. Angular positions in three dimensions were simultaneously recorded of the distal phalanx of the middle finger and hand and, in additional experiments to determine the mechanism of ball release in more detail, three middle finger phalanges and the hand. Different phases of ball release were determined by pressure-sensitive microswitches on the proximal and distal phalanges of the middle finger. Irrespective of whether the subjects were seated or were standing, for all throws at all speeds, finger flexion did not occur before ball release. That is, up until final release of the ball, the fingers only underwent extension associated with hand opening. For fast throws, at the instant of final ball release the fingers began to flex, presumably as a result of reactive forces associated with release of the ball. Thus, in overarm throws made by recreational ball players, finger flexion movement does not appear to contribute to the generation of ball speed. PMID:8887213

  12. Anthropogenic emissions of highly reactive volatile organic compounds in eastern Texas inferred from oversampling of satellite (OMI) measurements of HCHO columns

    NASA Astrophysics Data System (ADS)

    Zhu, Lei; Jacob, Daniel J.; Mickley, Loretta J.; Marais, Eloïse A.; Cohan, Daniel S.; Yoshida, Yasuko; Duncan, Bryan N.; González Abad, Gonzalo; Chance, Kelly V.

    2014-11-01

    Satellite observations of formaldehyde (HCHO) columns provide top-down constraints on emissions of highly reactive volatile organic compounds (HRVOCs). This approach has been used previously in the US to estimate isoprene emissions from vegetation, but application to anthropogenic emissions has been stymied by lack of a discernable HCHO signal. Here we show that temporal oversampling of HCHO data from the Ozone Monitoring Instrument (OMI) for 2005-2008 enables detection of urban and industrial plumes in eastern Texas including Houston, Port Arthur, and Dallas/Fort Worth. By spatially integrating the HCHO enhancement in the Houston plume observed by OMI we estimate an anthropogenic HCHO source of 250 ± 140 kmol h-1. This implies that anthropogenic HRVOC emissions in Houston are 4.8 ± 2.7 times higher than reported by the US Environmental Protection Agency inventory, and is consistent with field studies identifying large ethene and propene emissions from petrochemical industrial sources.

  13. Thiobarbituric acid reactive substances and volatile compounds in chicken breast meat infused with plant extracts and subjected to electron beam irradiation.

    PubMed

    Rababah, T; Hettiarachchy, N S; Horax, R; Cho, M J; Davis, B; Dickson, J

    2006-06-01

    The effect of irradiation on thiobarbituric acid reactive substances (TBARS) and volatile compounds in raw and cooked nonirradiated and irradiated chicken breast meat infused with green tea and grape seed extracts was investigated. Chicken breast meat was vacuum infused with green tea extract (3,000 ppm), grape seed extract (3,000 ppm), or their combination (at a total of 6,000 ppm), irradiated with an electron beam, and stored at 5 degrees C for 12 d. The targeted irradiation dosage was 3.0 kGy and the average absorbed dosage was 3.12 kGy. Values of TBARS and volatile compound contents of raw and cooked chicken meat were determined during the 12-d storage period. Thiobarbituric acid reactive substances values ranged from 15.5 to 71.4 mg of malondialdehyde/kg for nonirradiated raw chicken and 17.3 to 80.1 mg of malondialdehyde/kg for irradiated raw chicken. Values for cooked chicken ranged from 31.4 to 386.2 and 38.4 to 504.1 mg of malondialdehyde/kg for nonirradiated and irradiated chicken, respectively. Irradiation increased TBARS and hexanal values of controls and meat infused with plant extracts. Hexanal had the highest intensity of volatiles followed by pentanal and other volatiles. Cooking the samples significantly (P < 0.05) increased the amounts of TBARS and volatiles. Addition of plant extracts decreased the amount of TBARS as well as hexanal and pentanal values. Although irradiation increases lipid oxidation, infusion of chicken meat with plant extracts could reduce lipid oxidation caused by irradiation. PMID:16776483

  14. Aerobic biodegradation of chlorinated ethenes in a fractured bedrock aquifer: quantitative assessment by compound-specific isotope analysis (CSIA) and reactive transport modeling.

    PubMed

    Pooley, Kathryn E; Blessing, Michaela; Schmidt, Torsten C; Haderlein, Stefan B; Macquarrie, Kerry T B; Prommer, Henning

    2009-10-01

    A model-based analysis of concentration and isotope data was carried out to assess natural attenuation of chlorinated ethenes in an aerobic fractured bedrock aquifer. Tetrachloroethene (PCE) concentrations decreased downgradient of the source, but constant delta13C signatures indicated the absence of PCE degradation. In contrast, geochemical and isotopic data demonstrated degradation of trichloroethene (TCE) and cis-1,2-dichloroethene (DCE) under the prevailing oxic conditions. Numerical modeling was employed to simulate isotopic enrichment of chlorinated ethenes and to evaluate alternative degradation pathway scenarios. Existing field information on groundwater flow, solute transport, geochemistry, and delta13C signatures of the chlorinated ethenes was integrated via reactive transport simulations. The results provided strong evidence for the occurrence of aerobic TCE and DCE degradation. The chlorinated ethene concentrations together with stable carbon isotope data allowed us to reliably constrain the assessment of the extent of biodegradation at the site and plume simulations quantitatively linked aerobic biodegradation with isotope signatures in the field. Our investigation provides the first quantitative assessment of aerobic biodegradation of chlorinated ethenes in a fractured rock aquifer based on compound specific stable isotope measurements and reactive transport modeling. PMID:19848161

  15. Recent advances in high performance poly(lactide): From ``green'' plasticization to super-tough materials via (reactive) compounding

    NASA Astrophysics Data System (ADS)

    Kfoury, Georgio; Raquez, Jean-Marie; Hassouna, Fatima; Odent, Jérémy; Toniazzo, Valérie; Ruch, David; Dubois, Philippe

    2013-12-01

    Due to its origin from renewable resources, its biodegradability, and recently, its industrial implementation at low costs, poly(lactide) (PLA) is considered as one of the most promising ecological, bio-sourced and biodegradable plastic materials to potentially and increasingly replace traditional petroleum derived polymers in many commodity and engineering applications. Beside its relatively high rigidity (high tensile strength and modulus compared with many common thermoplastics such as poly(ethylene terephthalate) (PET), high impact poly(styrene) (HIPS) and poly(propylene) (PP)), PLA suffers from an inherent brittleness, which can limit its applications especially where mechanical toughness such as plastic deformation at high impact rates or elongation is required. Therefore, the curve plotting stiffness vs. impact resistance and ductility must be shifted to higher values for PLA-based materials, while being preferably fully bio-based and biodegradable upon the application. This review aims to establish a state of the art focused on the recent progresses and preferably economically viable strategies developed in the literature for significantly improve the mechanical performances of PLA. A particular attention is given to plasticization as well as to impact resistance modification of PLA in the case of (reactive) blending PLA-based systems.

  16. Long-finger pollicization for macrodactyly of the thumb and index finger.

    PubMed

    Donohue, Kenneth W; Zlotolow, Dan A; Kozin, Scott H

    2014-01-01

    Pollicization of the long finger is rarely performed, and previously described for treating traumatic thumb and index finger loss. Because the long finger lacks the independence of motion and muscular attachments of the index finger, pollicization of the long finger requires modifications of the technique. We present the case of a 3-year-old girl with progressive macrodactyly of the thumb and index finger associated with a lipofibromatous hamartoma of the median nerve. The involved digits were severely enlarged, stiff, and nonfunctional. The child was treated with first and second ray resection followed by long-finger pollicization. Surgical pearls and pitfalls are discussed. PMID:24919138

  17. Evidence of the impact of deep convection on reactive Volatile Organic Compounds in the upper tropical troposphere during the AMMA experiment in West Africa

    NASA Astrophysics Data System (ADS)

    Bechara, J.; Borbon, A.; Jambert, C.; Colomb, A.; Perros, P. E.

    2010-11-01

    A large dataset of reactive trace gases was collected for the first time over West Africa during the African Monsoon Multidisciplinary Analysis (AMMA) field experiment in August 2006. Volatile Organic Compounds (VOC from C5-C9) were measured onboard the two French aircrafts the ATR-42 and the Falcon-20 by a new instrument AMOVOC (Airborne Measurement Of Volatile Organic Compounds). The goal of this study is (i) to characterize VOC distribution in the tropical region of West Africa (ii) to determine the impact of deep convection on VOC distribution and chemistry in the tropical upper troposphere (UT) and (iii) to characterize its spatial and temporal extensions. Experimental strategy consisted in sampling at altitudes between 0 and 12 km downwind of Mesoscale Convective Systems (MCS) and at cloud base. Biogenic and anthropogenic VOC distribution in West Africa is clearly affected by North to South emission gradient. Isoprene, the most abundant VOC, is at maximum level over the forest (1.26 ppb) while benzene reaches its maximum over the urban areas (0.11 ppb). First, a multiple physical and chemical tracers approach using CO, O3 and relative humidity was implemented to distinguish between convective and non-convective air masses. Then, additional tools based on VOC observations (tracer ratios, proxy of emissions and photochemical clocks) were adapted to characterize deep convection on a chemical, spatial and temporal basis. VOC vertical profiles show a "C-shaped" trend indicating that VOC-rich air masses are transported from the surface to the UT by deep convective systems. VOC mixing ratios in convective outflow are up to two times higher than background levels even for reactive and short-lived VOC (e.g. isoprene up to 0.19 ppb at 12 km-altitude) and are dependent on surface emission type. As a consequence, UT air mass reactivity increases from 0.52 s-1 in non-convective conditions to 0.95 s-1 in convective conditions. Fractions of boundary layer air contained in

  18. Combined experimental and theoretical study on the reactivity of compounds I and II in horseradish peroxidase biomimetics.

    PubMed

    Ji, Li; Franke, Alicja; Brindell, Małgorzata; Oszajca, Maria; Zahl, Achim; van Eldik, Rudi

    2014-10-27

    For the exploration of the intrinsic reactivity of two key active species in the catalytic cycle of horseradish peroxidase (HRP), Compound I (HRP-I) and Compound II (HRP-II), we generated in situ [Fe(IV) O(TMP(+.) )(2-MeIm)](+) and [Fe(IV) O(TMP)(2-MeIm)](0) (TMP=5,10,15,20-tetramesitylporphyrin; 2-MeIm=2-methylimidazole) as biomimetics for HRP-I and HRP-II, respectively. Their catalytic activities in epoxidation, hydrogen abstraction, and heteroatom oxidation reactions were studied in acetonitrile at -15 °C by utilizing rapid-scan UV/Vis spectroscopy. Comparison of the second-order rate constants measured for the direct reactions of the HRP-I and HRP-II mimics with the selected substrates clearly confirmed the outstanding oxidizing capability of the HRP-I mimic, which is significantly higher than that of HRP-II. The experimental study was supported by computational modeling (DFT calculations) of the oxidation mechanism of the selected substrates with the involvement of quartet and doublet HRP-I mimics ((2,4) Cpd I) and the closed-shell triplet spin HRP-II model ((3) Cpd II) as oxidizing species. The significantly lower activation barriers calculated for the oxidation systems involving (2,4) Cpd I than those found for (3) Cpd II are in line with the much higher oxidizing efficiency of the HRP-I mimic proven in the experimental part of the study. In addition, the DFT calculations show that all three reaction types catalyzed by HRP-I occur on the doublet spin surface in an effectively concerted manner, whereas these reactions may proceed in a stepwise mechanism with the HRP-II mimic as oxidant. However, the high desaturation or oxygen rebound barriers during CH bond activation processes by the HRP-II mimic predict a sufficient lifetime for the substrate radical formed through hydrogen abstraction. Thus, the theoretical calculations suggest that the dissociation of the substrate radical may be a more favorable pathway than desaturation or

  19. Quinoline-Based Compound BPIQ Exerts Anti-Proliferative Effects on Human Retinoblastoma Cells via Modulating Intracellular Reactive Oxygen Species.

    PubMed

    Cheng, Kai-Chun; Hung, Chun-Tzu; Chen, Kuo-Jen; Wu, Wen-Chuan; Suen, Jau-Ling; Chang, Cheng-Hsien; Lu, Chi-Yu; Tseng, Chih-Hua; Chen, Yeh-Long; Chiu, Chien-Chih

    2016-04-01

    Retinoblastoma (Rb) is the most common primary intraocular malignant tumor of childhood. It is important to develop the strategy for Rb treatment. We have tested a quinolone derivative 2,9-bis[2-(pyrrolidin-1-yl)ethoxy]-6-{4-[2-(pyrrolidin-1-yl)ethoxy]phenyl}-11H-indeno[1,2-c]quinolin-11-one (BPIQ) for its anti-cancer effects against Rb via cultured human Rb cell line Y79. Our results showed that BPIQ significantly inhibits cell growth of Y79. Furthermore, the flow cytometer-based assays and Western blotting showed that BPIQ induces the apoptosis of Y79 via increasing the level of reactive oxygen species (ROS). Besides, the activation of γH2AX, a DNA damage sensor in human Y79 cells was also observed, indicating the potential of BPIQ for causing DNA damage of Rb cells. On the contrary, BPIQ-induced apoptosis of Y79 cells was attenuated significantly by N-acetyl-L-cysteine (NAC), an ROS scavenger. The results of Western blot showed that BPIQ down-regulates the levels of anti-apoptotic proteins Bcl-2, survivin and XIAP while up-regulates the pro-apoptotic proteins Bad, Bax and Bid. Our present study demonstrated the anti-proliferative effect of BPIQ in human Y79 cells. The inhibitory effect of BPIQ on the proliferation of Y79 cells is, at least, partly mediated by the regulation of ROS and DNA damage pathway. In conclusion, BPIQ may provide an alternative option in the chemotherapeutics or chemoprevention on the Rb therapy in the future. PMID:26564153

  20. From viscous fingering to bulk elastic fingering in soft materials

    NASA Astrophysics Data System (ADS)

    Saintyves, Baudouin; Biggins, John; Wei, Zhiyan; Mora, Serge; Dauchot, Olivier; Mahadevan, L.; Bouchaud, Elisabeth

    2014-03-01

    Systematic experiments have been performed in purely elastic polyacrylamide gels in Hele-Shaw cells. We have shown that a bulk fingering instability arises in the highly deformable confined elastomers. It shares some similarities with the famous Saffman-Taylor instability, but a systematic study shows that surface tension is not relevant. This instability is sub-critical, with a clear hysteretic behavior. Our experimental observations have been compared very favorably to theoretical and finite element simulations results. In particular, the instability wavelength and the critical front advance have been shown to be proportional to the distance between the two glass plates constituting the cell. We have also shown that in Maxwell viscoelastic fluids, one crosses over continuously from a viscous to an elastic fingering instability.

  1. Quantification of reactive carbonyl compounds in icodextrin-based peritoneal dialysis fluids by combined UHPLC-DAD and -MS/MS detection.

    PubMed

    Gensberger-Reigl, Sabrina; Huppert, Jochen; Pischetsrieder, Monika

    2016-01-25

    During heat sterilization of peritoneal dialysis (PD) fluids, the glucose component is partially degraded. The formed glucose degradation products impair biocompatibility and limit the long-term application of PD fluids. As an alternative to glucose, icodextrin, a polyglucose, is used as osmotic agent in PD fluids. After targeted screening for reactive carbonyl compounds, NMR- and MS-analyses very recently revealed 4-deoxyglucosone (4-DG), 3-deoxyglucosone (3-DG), 3-deoxygalactosone (3-DGal), 3,4-dideoxypentosone (3,4-DDPS), and 5-hydroxymethylfurfural (5-HMF) as main polyglucose degradation products (pGDPs) in icodextrin-based PD fluids. Now, the present study established and validated a UHPLC method with DAD as well as a UHPLC-MS/MS method for the first-time quantification of those five major pGDPs in commercial icodextrin PD fluids after derivatization with o-phenylenediamine. Thus, 4-DG was identified to be the main degradation product (in concentrations up to 20 μM). In contrast to the values measured in glucose-based products, the concentration of 3-DGal (≤ 16 μM) was higher than the concentration of 3-DG (≤ 7 μM) indicating different reaction pathways starting from polyglucose compared to glucose. The compounds 3,4-DDPS and 5-HMF were present in minor quantities (≤ 0.3 μM each). PMID:26540628

  2. Mechanical model of a single tendon finger

    NASA Astrophysics Data System (ADS)

    Rossi, Cesare; Savino, Sergio

    2013-10-01

    The mechanical model of a single tendon three phalanxes finger is presented. By means of the model both kinematic and dynamical behavior of the finger itself can be studied. This finger is a part of a more complex mechanical system that consists in a four finger grasping device for robots or in a five finger human hand prosthesis. A first prototype has been realized in our department in order to verify the real behavior of the model. Some results of both kinematic and dynamical behavior are presented.

  3. Characteristics, source apportionment and reactivity of ambient volatile organic compounds at Dinghu Mountain in Guangdong Province, China.

    PubMed

    Wu, Fangkun; Yu, Ye; Sun, Jie; Zhang, Junke; Wang, Jian; Tang, Guiqian; Wang, Yuesi

    2016-04-01

    Volatile organic compounds (VOCs) play a very important role in the formation of ozone and secondary organic aerosols. The concentrations, compositions, and variability of VOCs were measured from 2005 to 2008 at Dinghu Mountain Forest Ecosystem Research Station, a remote station in Southeast China. Weekly samples were collected in the Dinghu Mountain area and were analysed via gas chromatography-mass spectrometry. The results revealed that the total VOC concentrations decreased continuously and that the dominant VOC components were alkanes (43%) and aromatics (33%), followed by halo-hydrocarbons (12%) and alkenes (12%). The general trend of seasonal variation indicated higher concentrations in spring and lower concentrations in summer. The positive matrix factorization model was used to identify the sources of the VOCs. Seven sources were resolved by the PMF model: (1) vehicular emissions, which contributed 25% of the total VOC concentration; (2) industrial sources and regional transportation, contributing 17%; (3) paint solvent use, contributing 17%; (4) fuel evaporation, contributing 13%; (5) stationary combustion sources, contributing 12%; (6) biogenic emissions, contributing 10%; and aged VOCs, contributing only 6%. The HYSPLIT model was used to analyse the effect of pollutant transport, and the results indicated that the transport of pollutants from cities cannot be ignored. Finally, the OH radical loss rates and ozone formation potentials (OFPs) were calculated, and the results indicated isoprene to have the highest OH radical loss rate and toluene to be the largest contributor to the OFP at the Dinghu Mountain site. PMID:26803733

  4. Impact of Finger Type in Fingerprint Authentication

    NASA Astrophysics Data System (ADS)

    Gafurov, Davrondzhon; Bours, Patrick; Yang, Bian; Busch, Christoph

    Nowadays fingerprint verification system is the most widespread and accepted biometric technology that explores various features of the human fingers for this purpose. In general, every normal person has 10 fingers with different size. Although it is claimed that recognition performance with little fingers can be less accurate compared to other finger types, to our best knowledge, this has not been investigated yet. This paper presents our study on the topic of influence of the finger type into fingerprint recognition performance. For analysis we employ two fingerprint verification software packages (one public and one commercial). We conduct test on GUC100 multi sensor fingerprint database which contains fingerprint images of all 10 fingers from 100 subjects. Our analysis indeed confirms that performance with small fingers is less accurate than performance with the others fingers of the hand. It also appears that best performance is being obtained with thumb or index fingers. For example, performance deterioration from the best finger (i.e. index or thumb) to the worst fingers (i.e. small ones) can be in the range of 184%-1352%.

  5. Does finger sense predict addition performance?

    PubMed

    Newman, Sharlene D

    2016-05-01

    The impact of fingers on numerical and mathematical cognition has received a great deal of attention recently. However, the precise role that fingers play in numerical cognition is unknown. The current study explores the relationship between finger sense, arithmetic and general cognitive ability. Seventy-six children between the ages of 5 and 12 participated in the study. The results of stepwise multiple regression analyses demonstrated that while general cognitive ability including language processing was a predictor of addition performance, finger sense was not. The impact of age on the relationship between finger sense, and addition was further examined. The participants were separated into two groups based on age. The results showed that finger gnosia score impacted addition performance in the older group but not the younger group. These results appear to support the hypothesis that fingers provide a scaffold for calculation and that if that scaffold is not properly built, it has continued differential consequences to mathematical cognition. PMID:26993292

  6. Environmental chamber studies of atmospheric reactivities of volatile organic compounds: Effects of varying chamber and light source

    SciTech Connect

    Carter, W.; Luo, D.; Malkina, I.; Pierce, J.

    1995-05-01

    Photochemical oxidant models are essential tools for assessing effects of emissions changes on ground-level ozone formation. Such models are needed for predicting the ozone impacts of increased alternative fuel use. The gas-phase photochemical mechanism is an important component of these models because ozone is not emitted directly, but is formed from the gas-phase photochemical reactions of the emitted volatile organic compounds (VOCs) and oxides of nitrogen (NO{sub x}) in air. The chemistry of ground level ozone formation is complex; hundreds of types of VOCs being emitted into the atmosphere, and most of their atmospheric reactions are not completely understood. Because of this, no chemical model can be relied upon to give even approximately accurate predictions unless it has been evaluated by comparing its predictions with experimental data. Therefore an experimental and modeling study was conducted to assess how chemical mechanism evaluations using environmental chamber data are affected by the light source and other chamber characteristics. Xenon arc lights appear to give the best artificial representation of sunlight currently available, and experiments were conducted in a new Teflon chamber constructed using such a light source. Experiments were also conducted in an outdoor Teflon Chamber using new procedures to improve the light characterization, and in Teflon chambers using blacklights. These results, and results of previous runs other chambers, were compared with model predictions using an updated detailed chemical mechanism. The magnitude of the chamber radical source assumed when modeling the previous runs were found to be too high; this has implications in previous mechanism evaluations. Temperature dependencies of chamber effects can explain temperature dependencies in chamber experiments when Ta-300{degree}K, but not at temperatures below that.

  7. Prooxidant action of furanone compounds: implication of reactive oxygen species in the metal-dependent strand breaks and the formation of 8-hydroxy-2'-deoxyguanosine in DNA.

    PubMed

    Murakami, K; Haneda, M; Makino, T; Yoshino, M

    2007-07-01

    Prooxidant properties of furanone compounds including 2,5-furanone (furaneol, 4-hydroxy-2,5-dimethyl-furan-3-one), 4,5-furanone (4,5-dimethyl-3-hydroxy-2(5H)-furanone) (sotolone) and cyclotene (2-hydroxy-3-methyl-2-cyclopenten-1-one) were analyzed in relation to the metal-reducing activity. Only 2.5-furanone known as a "strawberry or pineapple furanone" inactivated aconitase the most sensitive enzyme to active oxygen in the presence of ferrous sulfate, suggesting the furaneol/iron-mediated generation of reactive oxygen species. 2,5-Furanone caused strand scission of pBR322 DNA in the presence of copper. Treatment of calf thymus DNA with 2,5-furanone plus copper produced 8-hydroxy-2'-deoxyguanosine in DNA. 2,5-Furanone showed a potent copper-reducing activity, and thus, DNA strand breaks and the formation of 8-hydroxy-2'-deoxyguanosine by 2,5-furanone can be initiated by the production of superoxide radical through the reduction of cupric ion to cuprous ion, resulting in the conversion to hydrogen peroxide and hydroxyl radical. However, an isomer and analog of 2,5-furanone, 4,5-furanone and cyclotene, respectively, did not show an inactivation of aconitase, DNA injuries including strand breakage and the formation of 8-hydroxy-2'-deoxyguanosine, and copper-reducing activity. Cytotoxic effect of 2,5-furanone with hydroxyketone structure can be explained by its prooxidant properties: furaneol/transition metal complex generates reactive oxygen species causing the inactivation of aconitase and the formation of DNA base damage by hydroxyl radical. PMID:17316945

  8. Concentrations and Fluxes of Water-Soluble Reactive Nitrogen Gases and Aerosol Compounds Above a Forest Canopy

    NASA Astrophysics Data System (ADS)

    Wolff, V.; Trebs, I.; Moravek, A.; Zhu, Z.; Meixner, F. X.

    2008-12-01

    HNO3 gradients are indicating net deposition. These gradients may be biased by micrometeorology and chemistry. For example, gradients in NH3 and HNO3 may be product of a phase change in the thermodynamic equilibrium between NH3, HNO3 and particulate NH4NO3, induced by a temperature and/or humidity gradient above the forest canopy. The equilibrium will be investigated for the pure NH3- HNO3- NH4NO3 triad as well as for more complex inorganic aerosol mixtures and chemical timescales will be compared to turbulent timescales, to estimate the potential of chemical interferences affecting the gradient. If compounds react sufficiently slow and may therefore be treated as passive tracers, prerequisites for the application of micrometeorological methods to derive fluxes from gradients will be investigated.

  9. Regional biogenic emissions of reactive volatile organic compounds (BVOC) from forests: First results on process studies, modelling and validation experiments (BEWA2000)

    NASA Astrophysics Data System (ADS)

    Rappenglück, B.; Bewa2000 Team

    2003-04-01

    The overall objective of the research consortia is to develop for a forest canopy a prognostic, validated emission model for primary and secondary volatile organic compounds (VOC) to be used for estimating regional biogenic emissions with a higher spatial and temporal resolution than present. To achieve this objective requires a better description of biosynthetic processes as well as chemical degradation mechanisms for reactive biogenic VOC in combination with a process-based model and latest vegetation specific land use information. Up to now several highlights were achieved within the different key activities. In the section model development a process-based isoprenoid emission model was supplemented with new differential equations especially taking into account the influence of transport-resistances for leaf gas-exchange. In biochemical process-studies related to the formation of isoprene in leaves it turned out that during daytime about 20-70% of the total carbon delivered to poplar leaves (photosynthesis + other sources) was derived from xylem-transported sugars. This finding indicates that xylem-delivered carbon may indeed act as a significant alternative carbon source for isoprenoid biosynthesis. First chemical process studies on the reaction of limonene with NO3 radicals (observed in the night and under low light conditions) in the EUPHORE (European Photoreactor) demonstrated a secondary particle formation. At the field site Waldstein (Fichtelgebirge) this reaction may result in maximum pinonealdhyde concentrations in the air and on particles observed in night periods. A first analysis of particle size distributions over the Norway spruce canopy showed the appearance of small particles (< 10nm) during early daytime. The first results demonstrate that the proposed approach of combining interdisciplinary field, laboratory and modelling exercises to address the complexity of the biosphere/atmosphere exchange of reactive trace gases will contribute

  10. Evidence of the impact of deep convection on reactive volatile organic compounds in the upper tropical troposphere during the AMMA experiment in West Africa

    NASA Astrophysics Data System (ADS)

    Bechara, J.; Borbon, A.; Jambert, C.; Colomb, A.; Perros, P. E.

    2009-09-01

    A large dataset of reactive trace gases was collected for the first time over West Africa during the African Monsoon Multidisciplinary Analysis (AMMA) field experiment in August 2006. Volatile Organic Compounds (VOC from C5-C9) were measured onboard the two French aircrafts the ATR-42 and the Falcon-20 by a new instrument AMOVOC. The goal of this study is (i) to characterize VOC distribution in the tropical region of West Africa (ii) to determine the impact of deep convection on VOC distribution and chemistry in the tropical upper troposphere (UT) and (iii) to characterize its spatial and temporal extensions. Experimental strategy consisted in sampling at altitudes between 0 and 12 km downwind of Mesoscale Convective Systems (MCS) and at cloud base. Biogenic and anthropogenic VOC distribution in West Africa is clearly affected by North to South emission gradient. Isoprene, the most abundant VOC, is at maximum level over the forest (1.26 ppb) while benzene reaches its maximum over the urban areas (0.11 ppb). First, a multiple physical and chemical tracers approach using CO, O3 and relative humidity was implemented to distinguish between convective and non-convective air masses. Then, additional tools based on VOC observations (tracer ratios, proxy of emissions and photochemical clocks) were adapted to characterize deep convection on a chemical, spatial and temporal basis. VOC vertical profiles show a "C-shaped" trend indicating that VOC-rich air masses are transported from the surface to the UT by deep convective systems. VOC mixing ratios in convective outflow are up to two times higher than background levels even for reactive and short-lived VOC (e.g. isoprene up to 0.19 ppb at 12 km-altitude) and are dependent on surface emission type. As a consequence, UT air mass reactivity increases from 0.52 s-1 in non-convective conditions to 0.95 s-1 in convective conditions. Fractions of boundary layer air contained in convective outflow are estimated to be 40±15

  11. 1-Boraadamantane: reactivity towards di(1-alkynyl)silicon and -tin compounds: first access to 7-metalla-2,5-diboranorbornane derivatives.

    PubMed

    Wrackmeyer, B; Milius, W; Klimkina, E V; Bubnov, Y N

    2001-01-01

    1-Boraadamantane (1) reacts with di(1-alkynyl)silicon and -tin compounds 2 (Me2M(C...CR)2: M=Si; R=Me (a), tBu (b), SiMe3 (c); M=Sn, R=SiMe3 (e)) in a 1:1 ratio by intermolecular 1,1-alkylboration, followed by intramolecular 1,1-vinylboration, to give siloles 5a-c and the stannole 5e, respectively, in which the tricyclic 1-boraadamantane system is enlarged by two carbon atoms. Owing to the high reactivity of 1, a second fast intermolecular 1,1-alkylboration competes with the intramolecular 1,1-vinylboration as the second major step in the reaction if the substituent R at the C...C bond is small (2a) and/or if the M-C... bond is also highly reactive, as in 2d (M=Sn, R= Me) and 2e (M=Sn, R=SiMe3). This leads finally to the novel octacyclic 7-metalla-2,5-diboranorbornane derivatives 8a, 8d, and 8e, of which 8e was characterized by X-ray analysis in the solid state. 1,1,2,2-Tetramethyldi(1-propynyl)disilane, MeC...C-SiMe2SiMe2-C...CMe (3), reacts with 1 to give mainly a 1,2-dihydro-1,2,5-disilaborepine derivative 9 and the octacyclic compound 11, which is analogous to 8a but with an Me4Si2 bridge. All new products were characterized in solution by 1H, 11B, 13C, 29Si, and 119Sn NMR spectroscopy. For 8 and 11, highly resolved 29Si and 119Sn NMR spectra revealed the first two-bond isotope-induced chemical shifts, 2delta10/11B(29Si) and 2delta10/11B(119Sn) respectively, to be reported. PMID:11288867

  12. Removal of ammonium-nitrogen from groundwater using a fully passive permeable reactive barrier with oxygen-releasing compound and clinoptilolite.

    PubMed

    Huang, Guoxin; Liu, Fei; Yang, Yingzhao; Deng, Wei; Li, Shengpin; Huang, Yuanying; Kong, Xiangke

    2015-05-01

    A novel fully passive permeable reactive barrier (PRB) with oxygen-releasing compound (ORC) and clinoptilolite was proposed for the removal of ammonium-nitrogen from groundwater. The PRB involves a combination of oxygen release, biological nitrification, ion exchange, and bioregeneration. A pilot-scale performance comparison experiment was carried out employing three parallel columns to assess the proposed PRB. The results showed that the PRB achieved nearly complete [Formula: see text] depletion (>99%). [Formula: see text] of 5.23-10.88 mg/L was removed, and [Formula: see text] of <1.93 mg/L and [Formula: see text] of 2.03-19.67 mg/L were generated. Ion exchange and biological nitrification both contributed to [Formula: see text] removal, and the latter played a dominant role under the condition of sufficient oxygen. Biological nitrification favored a delay in sorption saturation and a release of exchange sites. The ORC could sufficiently, efficiently supply oxygen for approximately 120 pore volumes. The clinoptilolite ensured a robust [Formula: see text] removal in case of temporary insufficient biological activities. No external alkalinity sources had to be supplied and no inhibition of aerobic metabolism occurred. The ceramicite had a negligible effect on the biomass growth. Based on the research findings, a full-scale continuous wall PRB was installed in Shenyang, China in 2012. PMID:25700350

  13. Current status of ultrasonography of the finger

    PubMed Central

    2016-01-01

    The recent development of advanced high-resolution transducers has enabled the fast, easy, and dynamic ultrasonographic evaluation of small, superficial structures such as the finger. In order to best exploit these advances, it is important to understand the normal anatomy and the basic pathologies of the finger, as exemplified by the following conditions involving the dorsal, volar, and lateral sections of the finger: sagittal band injuries, mallet finger, and Boutonnière deformity (dorsal aspect); flexor tendon tears, trigger finger, and volar plate injuries (volar aspect); gamekeeper’s thumb (Stener lesions) and other collateral ligament tears (lateral aspect); and other lesions. This review provides a basis for understanding the ultrasonography of the finger and will therefore be useful for radiologists. PMID:26753604

  14. On the fly finger knuckle print authentication

    NASA Astrophysics Data System (ADS)

    Abe, Narishige; Shinzaki, Takashi

    2014-05-01

    Finger knuckle print authentication has been researched not only as a supplemental authentication modality to fingerprint recognition but also as a method for logging into a PC or entering a building. However, in previous works, some specific devices were necessary to capture a finger knuckle print and users had to keep their fingers perfectly still to capture their finger knuckle. In this paper, we propose a new on the fly finger knuckle print authentication system using a general web camera. In our proposed authentication system, users can input their finger knuckle prints without needing their hand to remain motionless during image capture. We also evaluate the authentication accuracy of the proposed system, achieving an 7% EER under best conditions.

  15. Piezoelectric Actuators On A Cold Finger

    NASA Technical Reports Server (NTRS)

    Kuo, Chin-Po; Garba, John A.; Glaser, Robert J.

    1995-01-01

    Developmental system for active suppression of vibrations of cold finger includes three piezoelectric actuators bonded to outer surface. Actuators used to suppress longitudinal and lateral vibrations of upper end of cold finger by applying opposing vibrations. Cold finger in question is part of a cryogenic system associated with an infrared imaging detector. When fully developed, system would be feedback sensor/control/actuator system automatically adapting to changing vibrational environment and suppresses pressure-induced vibrations by imposing compensatory vibrations via actuators.

  16. Prosthetic Hand With Two Gripping Fingers

    NASA Technical Reports Server (NTRS)

    Norton, William E.; Belcher, Jewell B.; Vest, Thomas W.; Carden, James R.

    1993-01-01

    Prosthetic hand developed for amputee who retains significant portion of forearm. Outer end of device is end effector including two fingers, one moved by rotating remaining part of forearm about its longitudinal axis. Main body of end effector is end member supporting fingers, roller bearing assembly, and rack-and-pinion mechanism. Advantage of rack-and-pinion mechanism enables user to open or close gap between fingers with precision and force.

  17. An endophytic fungus isolated from finger millet (Eleusine coracana) produces anti-fungal natural products

    PubMed Central

    Mousa, Walaa K.; Schwan, Adrian; Davidson, Jeffrey; Strange, Philip; Liu, Huaizhi; Zhou, Ting; Auzanneau, France-Isabelle; Raizada, Manish N.

    2015-01-01

    Finger millet is an ancient African cereal crop, domesticated 7000 years ago in Ethiopia, reaching India at 3000 BC. Finger millet is reported to be resistant to various fungal pathogens including Fusarium sp. We hypothesized that finger millet may host beneficial endophytes (plant-colonizing microbes) that contribute to the antifungal activity. Here we report the first isolation of endophyte(s) from finger millet. Five distinct fungal species were isolated from roots and predicted taxonomically based on 18S rDNA sequencing. Extracts from three putative endophytes inhibited growth of F. graminearum and three other pathogenic Fusarium species. The most potent anti-Fusarium strain (WF4, predicted to be a Phoma sp.) was confirmed to behave as an endophyte using pathogenicity and confocal microscopy experiments. Bioassay-guided fractionation of the WF4 extract identified four anti-fungal compounds, viridicatol, tenuazonic acid, alternariol, and alternariol monomethyl ether. All the purified compounds caused dramatic breakage of F. graminearum hyphae in vitro. These compounds have not previously been reported to have anti-Fusarium activity. None of the compounds, except for tenuazonic acid, have previously been reported to be produced by Phoma. We conclude that the ancient, disease-tolerant crop, finger millet, is a novel source of endophytic anti-fungal natural products. This paper suggests the value of the crops grown by subsistence farmers as sources of endophytes and their natural products. Application of these natural chemicals to solve real world problems will require further validation. PMID:26539183

  18. An endophytic fungus isolated from finger millet (Eleusine coracana) produces anti-fungal natural products.

    PubMed

    Mousa, Walaa K; Schwan, Adrian; Davidson, Jeffrey; Strange, Philip; Liu, Huaizhi; Zhou, Ting; Auzanneau, France-Isabelle; Raizada, Manish N

    2015-01-01

    Finger millet is an ancient African cereal crop, domesticated 7000 years ago in Ethiopia, reaching India at 3000 BC. Finger millet is reported to be resistant to various fungal pathogens including Fusarium sp. We hypothesized that finger millet may host beneficial endophytes (plant-colonizing microbes) that contribute to the antifungal activity. Here we report the first isolation of endophyte(s) from finger millet. Five distinct fungal species were isolated from roots and predicted taxonomically based on 18S rDNA sequencing. Extracts from three putative endophytes inhibited growth of F. graminearum and three other pathogenic Fusarium species. The most potent anti-Fusarium strain (WF4, predicted to be a Phoma sp.) was confirmed to behave as an endophyte using pathogenicity and confocal microscopy experiments. Bioassay-guided fractionation of the WF4 extract identified four anti-fungal compounds, viridicatol, tenuazonic acid, alternariol, and alternariol monomethyl ether. All the purified compounds caused dramatic breakage of F. graminearum hyphae in vitro. These compounds have not previously been reported to have anti-Fusarium activity. None of the compounds, except for tenuazonic acid, have previously been reported to be produced by Phoma. We conclude that the ancient, disease-tolerant crop, finger millet, is a novel source of endophytic anti-fungal natural products. This paper suggests the value of the crops grown by subsistence farmers as sources of endophytes and their natural products. Application of these natural chemicals to solve real world problems will require further validation. PMID:26539183

  19. Bonding of silicon scanning mirror having vertical comb fingers

    NASA Astrophysics Data System (ADS)

    Lee, Jin-Ho; Ko, Young-Chul; Choi, Byoung-So; Kim, Jong-Min; Jeon, Duk Young

    2002-09-01

    A 1500 μm × 1200 μm silicon scanning mirror has been fabricated by using anodic bonding and flip chip bonding. This scanning mirror is mainly composed of two structures having vertical comb fingers. By anodic bonding between the silicon wafer and the Pyrex glass substrate, and following deep inductively coupled plasma reactive ion etching (ICPRIE), isolated comb electrodes were fabricated at the lower structure. However, gold signal lines for electrical connection to the electrodes, which were inserted between silicon and Pyrex glass, were damaged during anodic bonding. This problem was solved by using the proposed processes and signal lines were successfully fabricated with the contact resistance below several tens of ohms. By flip chip bonding, the upper and lower structures having vertical comb fingers were assembled. Vertical comb fingers of two structures were aligned with a microscope and the frames of two structures were bonded at 300 °C for 20 s using the eutectic bonding material - electroplated AuSn. Finally, the scanning mirror was successfully fabricated and could be used for laser display as a galvanometric vertical scanner.

  20. Error compensation during finger force production after one- and four-finger voluntarily fatiguing exercise.

    PubMed

    Kruger, Eric S; Hoopes, Josh A; Cordial, Rory J; Li, Sheng

    2007-08-01

    The effect of muscle fatigue on error compensation strategies during multi-finger ramp force production tasks was investigated. Thirteen young, healthy subjects were instructed to produce a total force with four fingers of the right hand to accurately match a visually displayed template. The template consisted of a 3-s waiting period, a 3-s ramp force production [from 0 to 30% maximal voluntary contraction (MVC)], and a 3-s constant force production. A series of 12 ramp trials was performed before and after fatigue. Fatigue was induced by a 60-s maximal isometric force production with either the index-finger only or with all four fingers during two separate testing sessions. The average percent of drop was 38.2% in the MVC of the index finger after index-finger fatiguing exercise and 38.3% in the MVC of all fingers after four-finger fatiguing exercise. The ability of individual fingers to compensate for each other's errors in order for the total force to match the preset template was quantified as the error compensation index (ECI), i.e., the ratio of the sum of variances of individual finger forces and the variance of the total force. By comparing pre- and post-fatigue performance during four-finger ramp force production, we observed that the variance of the total force was not significantly changed after one- or four-finger fatiguing exercise. The ECI significantly decreased after four-finger fatiguing exercise, especially during the last second of the ramp; while the ECI remained unchanged after index finger single-finger fatiguing exercise. These results suggest that the central nervous system is able to utilize the abundant degrees of freedom to compensate for partial impairment of the motor apparatus induced by muscle fatigue to maintain the desired performance. However, this ability is significantly decreased when all elements of the motor apparatus are impaired. PMID:17443316

  1. Invariantly propagating dissolution fingers in finite-width systems

    NASA Astrophysics Data System (ADS)

    Dutka, Filip; Szymczak, Piotr

    2016-04-01

    Dissolution fingers are formed in porous medium due to positive feedback between transport of reactant and chemical reactions [1-4]. We investigate two-dimensional semi-infinite systems, with constant width W in one direction. In numerical simulations we solve the Darcy flow problem combined with advection-dispersion-reaction equation for the solute transport to track the evolving shapes of the fingers and concentration of reactant in the system. We find the stationary, invariantly propagating finger shapes for different widths of the system, flow and reaction rates. Shape of the reaction front, turns out to be controlled by two dimensionless numbers - the (width-based) Péclet number PeW = vW/Dφ0 and Damköhler number DaW = ksW/v, where k is the reaction rate, s - specific reactive surface area, v - characteristic flow rate, D - diffusion coefficient of the solute, and φ0 - initial porosity of the rock matrix. Depending on PeW and DaW stationary shapes can be divided into seperate classes, e.g. parabolic-like and needle-like structures, which can be inferred from theoretical predictions. In addition we determine velocity of propagating fingers in time and concentration of reagent in the system. Our simulations are compared with natural forms (solution pipes). P. Ortoleva, J. Chadam, E. Merino, and A. Sen, Geochemical self-organization II: the reactive-infiltration instability, Am. J. Sci, 287, 1008-1040 (1987). M. L. Hoefner, and H. S. Fogler. Pore evolution and channel formation during flow and reaction in porous media, AIChE Journal 34, 45-54 (1988). C. E. Cohen, D. Ding, M. Quintard, and B. Bazin, From pore scale to wellbore scale: impact of geometry on wormhole growth in carbonate acidization, Chemical Engineering Science 63, 3088-3099 (2008). P. Szymczak and A. J. C. Ladd, Reactive-infiltration nstabilities in rocks. Part II: Dissolution of a porous matrix, J. Fluid Mech. 738, 591-630 (2014).

  2. Atmospheric reactivity of hydroxyl radicals with guaiacol (2-methoxyphenol), a biomass burning emitted compound: Secondary organic aerosol formation and gas-phase oxidation products

    NASA Astrophysics Data System (ADS)

    Lauraguais, Amélie; Coeur-Tourneur, Cécile; Cassez, Andy; Deboudt, Karine; Fourmentin, Marc; Choël, Marie

    2014-04-01

    Methoxyphenols are low molecular weight semi-volatile polar aromatic compounds produced from the pyrolysis of wood lignin. The reaction of guaiacol (2-methoxyphenol) with hydroxyl radicals has been studied in the LPCA simulation chamber at (294 ± 2) K, atmospheric pressure, low relative humidity (RH < 1%) and under high-NOx conditions using CH3ONO as OH source. The aerosol production was monitored using a SMPS (Scanning Mobility Particle Sizer); the SOA yields were in the range from 0.003 to 0.87 and the organic aerosol formation can be expressed by a one-product gas/particle partitioning absorption model. Transmission (TEM) and Scanning (SEM) Electron Microscopy observations were performed to characterize the physical state of SOA produced from the OH reaction with guaiacol; they display both liquid and solid particles (in an amorphous state). GC-FID (Gas Chromatography - Flame Ionization Detection) and GC-MS (Gas Chromatography - Mass Spectrometry) analysis show the formation of nitroguaiacol isomers as main oxidation products in the gas- and aerosol-phases. In the gas-phase, the formation yields were (10 ± 2) % for 4-nitroguaiacol (1-hydroxy-2-methoxy-4-nitrobenzene; 4-NG) and (6 ± 2) % for 3- or 6-nitroguaiacol (1-hydroxy-2-methoxy-3-nitrobenzene or 1-hydroxy-2-methoxy-6-nitrobenzene; 3/6-NG; the standards are not commercially available so both isomers cannot be distinguished) whereas in SOA their yield were much lower (≤0.1%). To our knowledge, this work represents the first identification of nitroguaiacols as gaseous oxidation products of the OH reaction with guaiacol. As the reactivity of nitroguaiacols with atmospheric oxidants is probably low, we suggest using them as biomass burning emission gas tracers. The atmospheric implications of the guaiacol + OH reaction are also discussed.

  3. Ammonium-nitrogen-contaminated groundwater remediation by a sequential three-zone permeable reactive barrier (multibarrier) with oxygen-releasing compound (ORC)/clinoptilolite/spongy iron: column studies.

    PubMed

    Huang, Guoxin; Liu, Fei; Yang, Yingzhao; Kong, Xiangke; Li, Shengpin; Zhang, Ying; Cao, Dejun

    2015-03-01

    A novel sequential permeable reactive barrier (multibarrier), composed of oxygen-releasing compound (ORC)/clinoptilolite/spongy iron zones in series, was proposed for ammonium-nitrogen-contaminated groundwater remediation. Column experiments were performed to: (1) evaluate the overall NH4(+)-N removal performance of the proposed multibarrier, (2) investigate nitrogen transformation in the three zones, (3) determine the reaction front progress, and (4) explore cleanup mechanisms for inorganic nitrogens. The results showed that NH4 (+)-N percent removal by the multibarrier increased up to 90.43 % after 21 pore volumes (PVs) at the influent dissolved oxygen of 0.68∼2.45 mg/L and pH of 6.76∼7.42. NH4(+)-N of 4.06∼10.49 mg/L was depleted and NOx(-)-N (i.e., NO3 (-)-N + NO2(-)-N) of 4.26∼9.63 mg/L was formed before 98 PVs in the ORC zone. NH4(+)-N of ≤4.76 mg/L was eliminated in the clinoptilolite zone. NOx(-)-N of 10.44∼12.80 mg/L was lost before 21 PVs in the spongy iron zone. The clinoptilolite zone length should be reduced to 30 cm. Microbial nitrification played a dominant role in NH4(+)-N removal in the ORC zone. Ion exchange was majorly responsible for NH4(+)-N elimination in the clinoptilolite zone. Chemical reduction and hydrogenotrophic denitrification both contributed to NOx(-)-N transformation, but the chemical reduction capacity decreased after 21 PVs in the spongy iron. PMID:25256584

  4. Distribution, magnitudes, reactivities, ratios and diurnal patterns of volatile organic compounds in the Valley of Mexico during the MCMA 2002 & 2003 field campaigns

    NASA Astrophysics Data System (ADS)

    Velasco, E.; Lamb, B.; Westberg, H.; Allwine, E.; Sosa, G.; Arriaga-Colina, J. L.; Jobson, B. T.; Alexander, M. L.; Prazeller, P.; Knighton, W. B.; Rogers, T. M.; Grutter, M.; Herndon, S. C.; Kolb, C. E.; Zavala, M.; de Foy, B.; Volkamer, R.; Molina, L. T.; Molina, M. J.

    2007-01-01

    A wide array of volatile organic compound (VOC) measurements was conducted in the Valley of Mexico during the MCMA-2002 and 2003 field campaigns. Study sites included locations in the urban core, in a heavily industrial area and at boundary sites in rural landscapes. In addition, a novel mobile-laboratory-based conditional sampling method was used to collect samples dominated by fresh on-road vehicle exhaust to identify those VOCs whose ambient concentrations were primarily due to vehicle emissions. Four distinct analytical techniques were used: whole air canister samples with Gas Chromatography/Flame Ionization Detection (GC-FID), on-line chemical ionization using a Proton Transfer Reaction Mass Spectrometer (PTR-MS), continuous real-time detection of olefins using a Fast Olefin Sensor (FOS), and long path measurements using UV Differential Optical Absorption Spectrometers (DOAS). The simultaneous use of these techniques provided a wide range of individual VOC measurements with different spatial and temporal scales. The VOC data were analyzed to understand concentration and spatial distributions, diurnal patterns, origin and reactivity in the atmosphere of Mexico City. The VOC burden (in ppbC) was dominated by alkanes (60%), followed by aromatics (15%) and olefins (5%). The remaining 20% was a mix of alkynes, halogenated hydrocarbons, oxygenated species (esters, ethers, etc.) and other unidentified VOCs. However, in terms of ozone production, olefins were the most relevant hydrocarbons. Elevated levels of toxic hydrocarbons, such as 1,3-butadiene, benzene, toluene and xylenes, were also observed. Results from these various analytical techniques showed that vehicle exhaust is the main source of VOCs in Mexico City and that diurnal patterns depend on vehicular traffic in addition to meteorological processes. Finally, examination of the VOC data in terms of lumped modeling VOC classes and its comparison to the VOC lumped emissions reported in other photochemical air

  5. Distribution, magnitudes, reactivities, ratios and diurnal patterns of volatile organic compounds in the Valley of Mexico during the MCMA 2002 and 2003 field campaigns

    NASA Astrophysics Data System (ADS)

    Velasco, E.; Lamb, B.; Westberg, H.; Allwine, E.; Sosa, G.; Arriaga-Colina, J. L.; Jobson, B. T.; Alexander, M.; Prazeller, P.; Knighton, W. B.; Rogers, T. M.; Grutter, M.; Herndon, S. C.; Kolb, C. E.; Zavala, M.; de Foy, B.; Volkamer, R.; Molina, L. T.; Molina, M. J.

    2006-08-01

    A wide array of volatile organic compound (VOC) measurements was conducted in the Valley of Mexico during the MCMA-2002 and 2003 field campaigns. Study sites included locations in the urban core, in a heavily industrial area and at boundary sites in rural landscapes. In addition, a novel mobile-laboratory-based conditional sampling method was used to collect samples dominated by fresh on-road vehicle exhaust to identify those VOCs whose ambient concentrations were primarily due to vehicle emissions. Five distinct analytical techniques were used: whole air canister samples with Gas Chromatography/Flame Ionization Detection (GC-FID), on-line chemical ionization using a Proton Transfer Reaction Mass Spectrometer (PTR-MS), continuous real-time detection of olefins using a Fast Olefin Sensor (FOS), and long path measurements using UV Differential Optical Absorption Spectrometers (DOAS). The simultaneous use of these techniques provided a wide range of individual VOC measurements with different spatial and temporal scales. The VOC data were analyzed to understand concentration and spatial distributions, diurnal patterns, origin and reactivity in the atmosphere of Mexico City. The VOC burden (in ppbC) was dominated by alkanes (60%), followed by aromatics (15%) and olefins (5%). The remaining 20% was a mix of alkynes, halogenated hydrocarbons, oxygenated species (esters, ethers, etc.) and other unidentified VOCs. However, in terms of ozone production, olefins were the most relevant hydrocarbons. Elevated levels of toxic hydrocarbons, such as 1,3-butadiene, benzene, toluene and xylenes were also observed. Results from these various analytical techniques showed that vehicle exhaust is the main source of VOCs in Mexico City and that diurnal patterns depend on vehicular traffic. Finally, examination of the VOC data in terms of lumped modeling VOC classes and its comparison to the VOC lumped emissions reported in other photochemical air quality modeling studies suggests that

  6. Creating Number Semantics through Finger Movement Perception

    ERIC Educational Resources Information Center

    Badets, Arnaud; Pesenti, Mauro

    2010-01-01

    Communication, language and conceptual knowledge related to concrete objects may rely on the sensory-motor systems from which they emerge. How abstract concepts can emerge from these systems is however still unknown. Here we report a functional interaction between a specific meaningful finger movement, such as a finger grip closing, and a concept…

  7. Analysis and treatment of finger sucking.

    PubMed Central

    Ellingson, S A; Miltenberger, R G; Stricker, J M; Garlinghouse, M A; Roberts, J; Galensky, T L; Rapp, J T

    2000-01-01

    We analyzed and treated the finger sucking of 2 developmentally typical children aged 7 and 10 years. The functional analysis revealed that the finger sucking of both children was exhibited primarily during alone conditions, suggesting that the behavior was maintained by automatic reinforcement. An extended analysis provided support for this hypothesis and demonstrated that attenuation of stimulation produced by the finger sucking resulted in behavior reductions for both children. Treatment consisted of having each child wear a glove on the relevant hand during periods when he or she was alone. Use of the glove produced zero levels of finger sucking for 1 participant, whereas only moderate reductions were obtained for the other. Subsequently, an awareness enhancement device was used that produced an immediate reduction in finger sucking. PMID:10738951

  8. Feasibility of novel (H3C)nX(SiH3)3-n compounds (X = B, Al, Ga, In): structure, stability, reactivity, and Raman characterization from ab initio calculations.

    PubMed

    Dos Santos, Renato B; Rivelino, R; Mota, F de Brito; Kakanakova-Georgieva, A; Gueorguiev, G K

    2015-02-21

    We employ ab initio calculations to predict the equilibrium structure, stability, reactivity, and Raman scattering properties of sixteen different (H3C)nX(SiH3)3-n compounds (X = B, Al, Ga, In) with n = 0-3. Among this methylsilylmetal family, only the (H3C)3X members, i.e., trimethylboron (TMB), trimethylaluminum (TMA), trimethylgallium (TMG), and trimethylindium (TMI), are currently well-studied. The remaining twelve compounds proposed here open up a two-dimensional array of new possibilities for precursors in various deposition processes, and evoke potential applications in the chemical synthesis of other compounds. We infer that within the (H3C)nX(SiH3)3-n family, the compounds with fewer silyl groups (and consequently with more methyl groups) are less reactive and more stable. This trend is verified from the calculated cohesive energy, Gibbs free energy of formation, bond strength, and global chemical indices. Furthermore, we propose sequential reaction routes for the synthesis of (H3C)nX(SiH3)3-n by substitution of methyl by silyl groups, where the silicon source is the silane gas. The corresponding reaction barriers for these chemical transformations lie in the usual energy range typical for MOCVD processes. We also report the Raman spectra and light scattering properties of the newly proposed (H3C)nX(SiH3)3-n compounds, in comparison with available data of known members of this family. Thus, our computational experiment provides useful information for a systematic understanding of the stability/reactivity and for the identification of these compounds. PMID:25599815

  9. Fingering in Stochastic Growth Models

    PubMed Central

    Aristotelous, Andreas C.; Durrett, Richard

    2015-01-01

    Motivated by the widespread use of hybrid-discrete cellular automata in modeling cancer, two simple growth models are studied on the two dimensional lattice that incorporate a nutrient, assumed to be oxygen. In the first model the oxygen concentration u(x, t) is computed based on the geometry of the growing blob, while in the second one u(x, t) satisfies a reaction-diffusion equation. A threshold θ value exists such that cells give birth at rate β(u(x, t) − θ)+ and die at rate δ(θ − u(x, t)+. In the first model, a phase transition was found between growth as a solid blob and “fingering” at a threshold θc = 0.5, while in the second case fingering always occurs, i.e., θc = 0. PMID:26430353

  10. Differing Dynamics of Intrapersonal and Interpersonal Coordination: Two-finger and Four-Finger Tapping Experiments

    PubMed Central

    Kodama, Kentaro; Furuyama, Nobuhiro; Inamura, Tetsunari

    2015-01-01

    Finger-tapping experiments were conducted to examine whether the dynamics of intrapersonal and interpersonal coordination systems can be described equally by the Haken—Kelso—Bunz model, which describes inter-limb coordination dynamics. This article reports the results of finger-tapping experiments conducted in both systems. Two within-subject factors were investigated: the phase mode and the number of fingers. In the intrapersonal experiment (Experiment 1), the participants were asked to tap, paced by a gradually hastening auditory metronome, looking at their fingers moving, using the index finger in the two finger condition, or the index and middle finger in the four-finger condition. In the interpersonal experiment (Experiment 2), pairs of participants performed the task while each participant used the outside hand, tapping with the index finger in the two finger condition, or the index and middle finger in the four-finger condition. Some results did not agree with the HKB model predictions. First, from Experiment 1, no significant difference was observed in the movement stability between the in-phase and anti-phase modes in the two finger condition. Second, from Experiment 2, no significant difference was found in the movement stability between the in-phase and anti-phase mode in the four-finger condition. From these findings, different coordination dynamics were inferred between intrapersonal and interpersonal coordination systems against prediction from the previous studies. Results were discussed according to differences between intrapersonal and interpersonal coordination systems in the availability of perceptual information and the complexity in the interaction between limbs derived from a nested structure. PMID:26070119

  11. Finger wear detection for production line battery tester

    DOEpatents

    Depiante, Eduardo V.

    1997-01-01

    A method for detecting wear in a battery tester probe. The method includes providing a battery tester unit having at least one tester finger, generating a tester signal using the tester fingers and battery tester unit with the signal characteristic of the electrochemical condition of the battery and the tester finger, applying wavelet transformation to the tester signal including computing a mother wavelet to produce finger wear indicator signals, analyzing the signals to create a finger wear index, comparing the wear index for the tester finger with the index for a new tester finger and generating a tester finger signal change signal to indicate achieving a threshold wear change.

  12. Finger wear detection for production line battery tester

    DOEpatents

    Depiante, E.V.

    1997-11-18

    A method is described for detecting wear in a battery tester probe. The method includes providing a battery tester unit having at least one tester finger, generating a tester signal using the tester fingers and battery tester unit with the signal characteristic of the electrochemical condition of the battery and the tester finger, applying wavelet transformation to the tester signal including computing a mother wavelet to produce finger wear indicator signals, analyzing the signals to create a finger wear index, comparing the wear index for the tester finger with the index for a new tester finger and generating a tester finger signal change signal to indicate achieving a threshold wear change. 9 figs.

  13. Trigger finger, tendinosis, and intratendinous gene expression.

    PubMed

    Lundin, A-C; Aspenberg, P; Eliasson, P

    2014-04-01

    The pathogenesis of trigger finger has generally been ascribed to primary changes in the first annular ligament. In contrast, we recently found histological changes in the tendons, similar to the findings in Achilles tendinosis or tendinopathy. We therefore hypothesized that trigger finger tendons would show differences in gene expression in comparison to normal tendons in a pattern similar to what is published for Achilles tendinosis. We performed quantitative real-time polymerase chain reaction on biopsies from finger flexor tendons, 13 trigger fingers and 13 apparently healthy control tendons, to assess the expression of 10 genes which have been described to be differently expressed in tendinosis (collagen type 1a1, collagen 3a1, MMP-2, MMP-3, ADAMTS-5, TIMP-3, aggrecan, biglycan, decorin, and versican). In trigger finger tendons, collagen types 1a1 and 3a1, aggrecan and biglycan were all up-regulated, and MMP-3and TIMP-3 were down-regulated. These changes were statistically significant and have been previously described for Achilles tendinosis. The remaining four genes were not significantly altered. The changes in gene expression support the hypothesis that trigger finger is a form of tendinosis. Because trigger finger is a common condition, often treated surgically, it could provide opportunities for clinical research on tendinosis. PMID:22882155

  14. Fingered core structure of nematic boojums

    NASA Astrophysics Data System (ADS)

    Kralj, Samo; Rosso, Riccardo; Virga, Epifanio G.

    2008-09-01

    Using the Landau-de Gennes phenomenological approach, we study the fine biaxial core structure of a boojum residing on the surface of a nematic liquid crystal phase. The core is formed by a negatively uniaxial finger, surrounded by a shell with maximal biaxiality. The characteristic finger’s length and the shell’s width are comparable to the biaxial correlation length. The finger tip is melted for topological reasons. Upon decreasing the surface anchoring strength below a critical value, the finger gradually leaves the bulk and it is expelled through the surface.

  15. Aesthetic finger prosthesis with silicone biomaterial

    PubMed Central

    Raghu, K M; Gururaju, C R; Sundaresh, K J; Mallikarjuna, Rachappa

    2013-01-01

    The fabrication of finger prosthesis is as much an art as it is science. The ideally constructed prosthesis must duplicate the missing structures so precisely that patients can appear in public without fear of attracting unwanted attraction. A 65-years-old patient reported with loss of his right index finger up to the second phalanx and wanted to get it replaced. An impression of the amputated finger and donor were made. A wax pattern of the prosthesis was fabricated using the donor impression; a trial was performed and flasked. Medical grade silicone was intrinsically stained to match the skin tone, following which it was packed, processed and finished. This clinical report describes a method of attaining retention by selective scoring of the master cast of partially amputated finger to enhance the vacuum effect at par with the proportional distribution of the positive forces on the tissues exerted by the prosthesis. PMID:23975917

  16. Finger Cooling During Cold Air Exposure.

    NASA Astrophysics Data System (ADS)

    Tikuisis, Peter

    2004-05-01

    This paper presents a method for predicting the onset of finger freezing. It is an extension of a tissue-cooling model originally developed to predict the onset of cheek freezing. The extension to the finger is presented as a more conservative warning of wind chill. Indeed, guidance on the risk of finger freezing is important not only to safeguard the finger, but also because it pertains more closely to susceptible facial features, such as the nose, than if only the risk of cheek freezing was provided. The importance of blood flow to the finger and the modeling of vaso-constriction are demonstrated through cooling predictions that agree reasonably well with several reported observations. Differences in the prediction between the present physiologic-based model and the engineering model used to develop the wind chill index are also discussed. New wind chill charts are presented that tabulate the mean cooling rates and corresponding onset times to freezing of the finger for various combinations of air temperature and wind speed. Results indicate that the surface of the finger cools to its freezing point in approximately one-eighth of the time predicted for the cheek. For combinations that result in the same wind chill temperature (WCT), the rate of finger cooling is faster at the higher wind speed. This asymmetry was previously disclosed through the application of the model to cheek cooling, and it reiterates the ambiguity associated with the reporting of WCT. It is further emphasized that the reporting of onset times to freezing, or safe exposure limits, is a more logical and meaningful alternative to the WCT.

  17. New Finger Biometric Method Using Near Infrared Imaging

    PubMed Central

    Lee, Eui Chul; Jung, Hyunwoo; Kim, Daeyeoul

    2011-01-01

    In this paper, we propose a new finger biometric method. Infrared finger images are first captured, and then feature extraction is performed using a modified Gaussian high-pass filter through binarization, local binary pattern (LBP), and local derivative pattern (LDP) methods. Infrared finger images include the multimodal features of finger veins and finger geometries. Instead of extracting each feature using different methods, the modified Gaussian high-pass filter is fully convolved. Therefore, the extracted binary patterns of finger images include the multimodal features of veins and finger geometries. Experimental results show that the proposed method has an error rate of 0.13%. PMID:22163741

  18. Finger multibiometric cryptosystems: fusion strategy and template security

    NASA Astrophysics Data System (ADS)

    Peng, Jialiang; Li, Qiong; Abd El-Latif, Ahmed A.; Niu, Xiamu

    2014-03-01

    We address two critical issues in the design of a finger multibiometric system, i.e., fusion strategy and template security. First, three fusion strategies (feature-level, score-level, and decision-level fusions) with the corresponding template protection technique are proposed as the finger multibiometric cryptosystems to protect multiple finger biometric templates of fingerprint, finger vein, finger knuckle print, and finger shape modalities. Second, we theoretically analyze different fusion strategies for finger multibiometric cryptosystems with respect to their impact on security and recognition accuracy. Finally, the performance of finger multibiometric cryptosystems at different fusion levels is investigated on a merged finger multimodal biometric database. The comparative results suggest that the proposed finger multibiometric cryptosystem at feature-level fusion outperforms other approaches in terms of verification performance and template security.

  19. Scattering Removal for Finger-Vein Image Restoration

    PubMed Central

    Yang, Jinfeng; Zhang, Ben; Shi, Yihua

    2012-01-01

    Finger-vein recognition has received increased attention recently. However, the finger-vein images are always captured in poor quality. This certainly makes finger-vein feature representation unreliable, and further impairs the accuracy of finger-vein recognition. In this paper, we first give an analysis of the intrinsic factors causing finger-vein image degradation, and then propose a simple but effective image restoration method based on scattering removal. To give a proper description of finger-vein image degradation, a biological optical model (BOM) specific to finger-vein imaging is proposed according to the principle of light propagation in biological tissues. Based on BOM, the light scattering component is sensibly estimated and properly removed for finger-vein image restoration. Finally, experimental results demonstrate that the proposed method is powerful in enhancing the finger-vein image contrast and in improving the finger-vein image matching accuracy. PMID:22737028

  20. Scattering removal for finger-vein image restoration.

    PubMed

    Yang, Jinfeng; Zhang, Ben; Shi, Yihua

    2012-01-01

    Finger-vein recognition has received increased attention recently. However, the finger-vein images are always captured in poor quality. This certainly makes finger-vein feature representation unreliable, and further impairs the accuracy of finger-vein recognition. In this paper, we first give an analysis of the intrinsic factors causing finger-vein image degradation, and then propose a simple but effective image restoration method based on scattering removal. To give a proper description of finger-vein image degradation, a biological optical model (BOM) specific to finger-vein imaging is proposed according to the principle of light propagation in biological tissues. Based on BOM, the light scattering component is sensibly estimated and properly removed for finger-vein image restoration. Finally, experimental results demonstrate that the proposed method is powerful in enhancing the finger-vein image contrast and in improving the finger-vein image matching accuracy. PMID:22737028

  1. Characterization of Antifungal Natural Products Isolated from Endophytic Fungi of Finger Millet (Eleusine coracana).

    PubMed

    Mousa, Walaa Kamel; Schwan, Adrian L; Raizada, Manish N

    2016-01-01

    Finger millet is an ancient African-Indian crop that is resistant to many pathogens including the fungus, Fusarium graminearum. We previously reported the first isolation of putative fungal endophytes from finger millet and showed that the crude extracts of four strains had anti-Fusarium activity. However, active compounds were isolated from only one strain. The objectives of this study were to confirm the endophytic lifestyle of the three remaining anti-Fusarium isolates, to identify the major underlying antifungal compounds, and to initially characterize the mode(s) of action of each compound. Results of confocal microscopy and a plant disease assay were consistent with the three fungal strains behaving as endophytes. Using bio-assay guided fractionation and spectroscopic structural elucidation, three anti-Fusarium secondary metabolites were purified and characterized. These molecules were not previously reported to derive from fungi nor have antifungal activity. The purified antifungal compounds were: 5-hydroxy 2(3H)-benzofuranone, dehydrocostus lactone (guaianolide sesquiterpene lactone), and harpagoside (an iridoide glycoside). Light microscopy and vitality staining were used to visualize the in vitro interactions between each compound and Fusarium; the results suggested a mixed fungicidal/fungistatic mode of action. We conclude that finger millet possesses fungal endophytes that can synthesize anti-fungal compounds not previously reported as bio-fungicides against F. graminearum. PMID:27598120

  2. Anthropomorphic finger antagonistically actuated by SMA plates.

    PubMed

    Engeberg, Erik D; Dilibal, Savas; Vatani, Morteza; Choi, Jae-Won; Lavery, John

    2015-10-01

    Most robotic applications that contain shape memory alloy (SMA) actuators use the SMA in a linear or spring shape. In contrast, a novel robotic finger was designed in this paper using SMA plates that were thermomechanically trained to take the shape of a flexed human finger when Joule heated. This flexor actuator was placed in parallel with an extensor actuator that was designed to straighten when Joule heated. Thus, alternately heating and cooling the flexor and extensor actuators caused the finger to flex and extend. Three different NiTi based SMA plates were evaluated for their ability to apply forces to a rigid and compliant object. The best of these three SMAs was able to apply a maximum fingertip force of 9.01N on average. A 3D CAD model of a human finger was used to create a solid model for the mold of the finger covering skin. Using a 3D printer, inner and outer molds were fabricated to house the actuators and a position sensor, which were assembled using a multi-stage casting process. Next, a nonlinear antagonistic controller was developed using an outer position control loop with two inner MOSFET current control loops. Sine and square wave tracking experiments demonstrated minimal errors within the operational bounds of the finger. The ability of the finger to recover from unexpected disturbances was also shown along with the frequency response up to 7 rad s(-1). The closed loop bandwidth of the system was 6.4 rad s(-1) when operated intermittently and 1.8 rad s(-1) when operated continuously. PMID:26292164

  3. Design and preliminary evaluation of the FINGER rehabilitation robot: controlling challenge and quantifying finger individuation during musical computer game play

    PubMed Central

    2014-01-01

    Background This paper describes the design and preliminary testing of FINGER (Finger Individuating Grasp Exercise Robot), a device for assisting in finger rehabilitation after neurologic injury. We developed FINGER to assist stroke patients in moving their fingers individually in a naturalistic curling motion while playing a game similar to Guitar Hero®a. The goal was to make FINGER capable of assisting with motions where precise timing is important. Methods FINGER consists of a pair of stacked single degree-of-freedom 8-bar mechanisms, one for the index and one for the middle finger. Each 8-bar mechanism was designed to control the angle and position of the proximal phalanx and the position of the middle phalanx. Target positions for the mechanism optimization were determined from trajectory data collected from 7 healthy subjects using color-based motion capture. The resulting robotic device was built to accommodate multiple finger sizes and finger-to-finger widths. For initial evaluation, we asked individuals with a stroke (n = 16) and without impairment (n = 4) to play a game similar to Guitar Hero® while connected to FINGER. Results Precision design, low friction bearings, and separate high speed linear actuators allowed FINGER to individually actuate the fingers with a high bandwidth of control (−3 dB at approximately 8 Hz). During the tests, we were able to modulate the subject’s success rate at the game by automatically adjusting the controller gains of FINGER. We also used FINGER to measure subjects’ effort and finger individuation while playing the game. Conclusions Test results demonstrate the ability of FINGER to motivate subjects with an engaging game environment that challenges individuated control of the fingers, automatically control assistance levels, and quantify finger individuation after stroke. PMID:24495432

  4. Ultrafast High-Resolution Mass Spectrometric Finger Pore Imaging in Latent Finger Prints

    NASA Astrophysics Data System (ADS)

    Elsner, Christian; Abel, Bernd

    2014-11-01

    Latent finger prints (LFPs) are deposits of sweat components in ridge and groove patterns, left after human fingers contact with a surface. Being important targets in biometry and forensic investigations they contain more information than topological patterns. With laser desorption mass spectrometry imaging (LD-MSI) we record `three-dimensional' finger prints with additional chemical information as the third dimension. Here we show the potential of fast finger pore imaging (FPI) in latent finger prints employing LD-MSI without a classical matrix in a high- spatial resolution mode. Thin films of gold rapidly sputtered on top of the sample are used for desorption. FPI employing an optical image for rapid spatial orientation and guiding of the desorption laser enables the rapid analysis of individual finger pores, and the chemical composition of their excretions. With this approach we rapidly detect metabolites, drugs, and characteristic excretions from the inside of the human organism by a minimally-invasive strategy, and distinguish them from chemicals in contact with fingers without any labeling. The fast finger pore imaging, analysis, and screening approach opens the door for a vast number of novel applications in such different fields as forensics, doping and medication control, therapy, as well as rapid profiling of individuals.

  5. Ultrafast High-Resolution Mass Spectrometric Finger Pore Imaging in Latent Finger Prints

    PubMed Central

    Elsner, Christian; Abel, Bernd

    2014-01-01

    Latent finger prints (LFPs) are deposits of sweat components in ridge and groove patterns, left after human fingers contact with a surface. Being important targets in biometry and forensic investigations they contain more information than topological patterns. With laser desorption mass spectrometry imaging (LD-MSI) we record ‘three-dimensional' finger prints with additional chemical information as the third dimension. Here we show the potential of fast finger pore imaging (FPI) in latent finger prints employing LD-MSI without a classical matrix in a high- spatial resolution mode. Thin films of gold rapidly sputtered on top of the sample are used for desorption. FPI employing an optical image for rapid spatial orientation and guiding of the desorption laser enables the rapid analysis of individual finger pores, and the chemical composition of their excretions. With this approach we rapidly detect metabolites, drugs, and characteristic excretions from the inside of the human organism by a minimally-invasive strategy, and distinguish them from chemicals in contact with fingers without any labeling. The fast finger pore imaging, analysis, and screening approach opens the door for a vast number of novel applications in such different fields as forensics, doping and medication control, therapy, as well as rapid profiling of individuals. PMID:25366032

  6. Ultrafast high-resolution mass spectrometric finger pore imaging in latent finger prints.

    PubMed

    Elsner, Christian; Abel, Bernd

    2014-01-01

    Latent finger prints (LFPs) are deposits of sweat components in ridge and groove patterns, left after human fingers contact with a surface. Being important targets in biometry and forensic investigations they contain more information than topological patterns. With laser desorption mass spectrometry imaging (LD-MSI) we record 'three-dimensional' finger prints with additional chemical information as the third dimension. Here we show the potential of fast finger pore imaging (FPI) in latent finger prints employing LD-MSI without a classical matrix in a high- spatial resolution mode. Thin films of gold rapidly sputtered on top of the sample are used for desorption. FPI employing an optical image for rapid spatial orientation and guiding of the desorption laser enables the rapid analysis of individual finger pores, and the chemical composition of their excretions. With this approach we rapidly detect metabolites, drugs, and characteristic excretions from the inside of the human organism by a minimally-invasive strategy, and distinguish them from chemicals in contact with fingers without any labeling. The fast finger pore imaging, analysis, and screening approach opens the door for a vast number of novel applications in such different fields as forensics, doping and medication control, therapy, as well as rapid profiling of individuals. PMID:25366032

  7. Miscible viscous fingering involving production of gel by chemical reactions

    NASA Astrophysics Data System (ADS)

    Nagatsu, Yuichiro; Hoshino, Kenichi

    2015-11-01

    We have experimentally investigated miscible viscous fingering with chemical reactions producing gel. Here, two systems were employed. In one system, sodium polyacrylate (SPA) solution and aluminum ion (Al3 +) solution were used as the more and less viscous liquids, respectively. In another system, SPA solution and ferric ion (Fe3 +) solution were used as the more and less viscous liquids, respectively. In the case of Al3 +, displacement efficiency was smaller than that in the non-reactive case, whereas in the case of Fe3 +, the displacement efficiency was larger. We consider that the difference in change of the patterns in the two systems will be caused by the difference in the properties of the gels. Therefore, we have measured the rheological properties of the gels by means of a rheometer. We discuss relationship between the VF patterns and the rheological measurement.

  8. Reconstruction of Extensive Volar Finger Defects with Double Cross-Finger Flaps

    PubMed Central

    Buehrer, Gregor; Arkudas, Andreas; Ludolph, Ingo; Horch, Raymund E.

    2016-01-01

    Summary: Cross-finger flaps still represent a viable option to reconstruct small- to medium-sized full-thickness finger defects but they are not commonly used if larger areas have to be covered. We present 2 cases showing a simple and pragmatic approach with homodigital double cross-finger flaps to reconstruct extensive volar finger soft-tissue defects. We observed very low donor-site morbidity and excellent functional and aesthetic outcomes. Furthermore, there is no need for microsurgical techniques or equipment when using this method. Although this case report only addresses volar defects, one might also think of applying this concept to dorsal defects using reversed double cross-finger flaps. PMID:27200255

  9. Perceiving fingers in single-digit arithmetic problems.

    PubMed

    Berteletti, Ilaria; Booth, James R

    2015-01-01

    In this study, we investigate in children the neural underpinnings of finger representation and finger movement involved in single-digit arithmetic problems. Evidence suggests that finger representation and finger-based strategies play an important role in learning and understanding arithmetic. Because different operations rely on different networks, we compared activation for subtraction and multiplication problems in independently localized finger somatosensory and motor areas and tested whether activation was related to skill. Brain activations from children between 8 and 13 years of age revealed that only subtraction problems significantly activated finger motor areas, suggesting reliance on finger-based strategies. In addition, larger subtraction problems yielded greater somatosensory activation than smaller problems, suggesting a greater reliance on finger representation for larger numerical values. Interestingly, better performance in subtraction problems was associated with lower activation in the finger somatosensory area. Our results support the importance of fine-grained finger representation in arithmetical skill and are the first neurological evidence for a functional role of the somatosensory finger area in proficient arithmetical problem solving, in particular for those problems requiring quantity manipulation. From an educational perspective, these results encourage investigating whether different finger-based strategies facilitate arithmetical understanding and encourage educational practices aiming at integrating finger representation and finger-based strategies as a tool for instilling stronger numerical sense. PMID:25852582

  10. Solid-state Forensic Finger sensor for integrated sampling and detection of gunshot residue and explosives: towards 'Lab-on-a-finger'.

    PubMed

    Bandodkar, Amay J; O'Mahony, Aoife M; Ramírez, Julian; Samek, Izabela A; Anderson, Sean M; Windmiller, Joshua R; Wang, Joseph

    2013-09-21

    Increasing security needs require field-deployable, on-the-spot detection tools for the rapid and reliable identification of gunshot residue (GSR) and nitroaromatic explosive compounds. This manuscript presents a simple, all-solid-state, wearable fingertip sensor for the rapid on-site voltammetric screening of GSR and explosive surface residues. To fabricate the new Forensic Fingers, we screen-print a three-electrode setup onto a nitrile finger cot, and coat another finger cot with an ionogel electrolyte layer. The new integrated sampling/detection methodology relies on 'voltammetry of microparticles' (VMP) and involves an initial mechanical transfer of trace amounts of surface-confined analytes directly onto the fingertip-based electrode contingent. Voltammetric measurements of the sample residues are carried out upon bringing the working electrode (printed on the index finger cot) in direct contact with a second finger cot coated with an ionogel electrolyte (worn on the thumb), thus completing the solid-state electrochemical cell. Sampling and screening are performed in less than four minutes and generate distinct voltammetric fingerprints which are specific to both GSR and explosives. The use of the solid, flexible ionogel electrolyte eliminates any liquid handling which can resolve problems associated with leakage, portability and contamination. A detailed study reveals that the fingertip detection system can rapidly identify residues of GSR and nitroaromatic compounds with high specificity, without compromising its attractive behavior even after undergoing repeated mechanical stress. This new integrated sampling/detection fingertip strategy holds considerable promise as a rapid, effective and low-cost approach for on-site crime scene investigations in various forensic scenarios. PMID:23865089

  11. Tide-induced fingering flow during submarine groundwater discharge

    NASA Astrophysics Data System (ADS)

    Greskowiak, Janek

    2013-04-01

    range of 2 m initiates fingering flow. Flatter beach slope, higher hydraulic conductivity and increasing tidal range support this behavior. In the cases of fingering flow, freshwater is squeezed upward and pinches out within the inter-tidal zone. Once pinched out, the discharge point slowly moves along at the beach surface towards the low-tide mark. Overall, the fingering process further complicates the flow pattern and the mixing of salt and freshwater in the inter-tidal zone compared to the cases where the saline recirculation cell remains stable. This may have an important implication for the hydrogeochemical processes in this zone and thus the mass flux of reactive chemicals from the land to the ocean. Boufadel, M. C. (2000). A mechanistic study of nonlinear solute transport in a groundwater-surface water system under steady state and transient hydraulic conditions, Water Resour. Res., 36(9), 2549 2565. Bratton, J.F. (2010). The Three Scales of Submarine Groundwater Flow and Discharge across Passive Continental Margins, The Journal of Geology, 2010, 118, 565-575. Kuan, W. K., G. Jin, P. Xin, C. Robinson, B. Gibbes, and L. Li (2012). Tidal influence on seawater intrusion in unconfined coastal aquifers, Water Resour. Res., 48, W02502, doi:10.1029/2011WR010678. Langevin, C.D., D.T. Thorne, Jr., A.M. Dausman, M.C. Sukop, and G. Weixing (2007). Seawat version 4: a computer program for simulation of multi-species solute and heat transport, Technical Report, U.S. Geological Survey Techniques and Methods Book 6, Chapter A22, 39 pp. Robinson, C., L. Li, and H. Prommer (2007). Tide-induced recirculation across the aquifer-ocean interface, Water Resour. Res., 43, W07428, doi:10.1029/2006WR005679. Moore, W.S. (2010). The Effect of Submarine Groundwater Discharge on the Ocean, Annu. Rev. Mar. Sci., 2, 59-88.

  12. Finger millet [Eleusine coracana (L.) Gaertn].

    PubMed

    Ceasar, Stanislaus Antony; Ignacimuthu, Savarimuthu

    2015-01-01

    Millets are the primary food source for millions of people in tropical regions of the world supplying mineral nutrition and protein. In this chapter, we describe an optimized protocol for the Agrobacterium-mediated transformation of finger millet variety GPU 45. Agrobacterium strain LBA4404 harboring plasmid pCAMBIA1301 which contains hygromycin phosphotransferase (hph) as selectable marker gene and β-glucuronidase (GUS) as reporter gene has been used. This protocol utilizes the shoot apex explants for the somatic embryogenesis and regeneration of finger millet after the transformation by Agrobacterium. Desiccation of explants during cocultivation helps for the better recovery of transgenic plants. This protocol is very useful for the efficient production of transgenic plants in finger millet through Agrobacterium-mediated transformation. PMID:25300836

  13. Axon reflexes in human cold exposed fingers.

    PubMed

    Daanen, H A; Ducharme, M B

    2000-02-01

    Exposure of fingers to severe cold induces cold induced vasodilatation (CIVD). The mechanism of CIVD is still debated. The original theory states that an axon reflex causes CIVD. To test this hypothesis, axon reflexes were evoked by electrical stimulation of the middle fingers of hands immersed in water at either 5 degrees C or 35 degrees C. Axon reflexes were pronounced in the middle finger of the hand in warm water, but absent from the hand in cold water, even though the stimulation was rated as "rather painful" to "painful". These results showed that axon reflexes do not occur in a cold-exposed hand and thus are unlikely to explain the CIVD phenomenon. PMID:10638384

  14. Reactive Leidenfrost droplets

    NASA Astrophysics Data System (ADS)

    Raufaste, C.; Bouret, Y.; Celestini, F.

    2016-05-01

    We experimentally investigate the reactivity of Leidenfrost droplets with their supporting substrates. Several organic liquids are put into contact with a copper substrate heated above their Leidenfrost temperature. As the liquid evaporates, the gaseous flow cleans the superficial copper oxide formed at the substrate surface and the reaction maintains a native copper spot below the evaporating droplet. The copper spot can reach several times the droplet size for the most reactive organic compounds. This study shows an interesting coupling between the physics of the Leidenfrost effect and the mechanics of reactive flows. Different applications are proposed such as drop motion tracking and vapor flow monitoring.

  15. A reverse flow cross finger pedicle skin flap from hemidorsum of finger.

    PubMed

    Mishra, Satyanarayan; Manisundaram, S

    2010-04-01

    A reverse-flow cross-finger pedicle skin flap raised from the hemidorsum has been used, which is a modification of the distally based dorsal cross-finger flap. The flap is raised from the hemidorsum at a plane above the paratenon, the distal-most location of the base being at the level of the distal interphalangeal joint. Thirty-two flaps were used from as many fingers of as many patients. Of these, 31 (97%) flaps survived fully; there was stiffness of finger in one (3%) patient and the two-point discrimination was 4-8mm (n=14). Follow-up period was 2 months to 3 years, the median being 1 year and 3 months. The advantages of this flap are that there is less disruption of veins and less visible disfigurement of the dorsum of the finger when compared to other pedicled cross-finger skin flaps. The disadvantage of this flap is its restricted width. It is recommended as the cross-finger pedicle skin flap of choice when the defect is not wide. PMID:19386561

  16. Thermoregulatory control of finger blood flow

    NASA Technical Reports Server (NTRS)

    Wenger, C. B.; Roberts, M. F.; Nadel, E. R.; Stolwijk, J. A. J.

    1975-01-01

    In the present experiment, exercise was used to vary internal temperature and ambient air heat control was used to vary skin temperature. Finger temperature was fixed at about 35.7 C. Esophageal temperature was measured with a thermocouple at the level of the left atrium, and mean skin temperature was calculated from a weighted mean of thermocouple temperatures at different skin sites. Finger blood flow was measured by electrocapacitance plethysmography. An equation in these quantities is given which accounts for the data garnered.

  17. Sensitivity-Based VOC Reactivity Calculation

    EPA Science Inventory

    Volatile Organic Compound (VOC) reactivity scales are used to compare the ozone-forming potentials of various compounds. The comparison allows for substitution of compounds to lessen formation of ozone from paints, solvents, and other products. Current reactivity scales for VOC c...

  18. Interaction of finger enslaving and error compensation in multiple finger force production

    PubMed Central

    Martin, Joel R.; Latash, Mark L.; Zatsiorsky, Vladimir M.

    2009-01-01

    Previous studies have documented two patterns of finger interaction during multi-finger pressing tasks, enslaving and error compensation, which do not agree with each other. Enslaving is characterized by positive correlation between instructed (master) and non-instructed (slave) finger(s) while error compensation can be described as a pattern of negative correlation between master and slave fingers. We hypothesize that pattern of finger interaction, enslaving or compensation, depends on the initial force level and the magnitude of the targeted force change. Subjects were instructed to press with four fingers (I - index, M - middle, R - ring, and L - little) from a specified initial force to a target forces following a ramp target line. Force-force relations between master and each of three slave fingers were analyzed during the ramp phase of trials by calculating correlation coefficients within each master-slave pair and then 2-factor ANOVA was performed to determine effect of initial force and force increase on the correlation coefficients. It was found that, as initial force increased, the value of the correlation coefficient decreased and in some cases became negative, i.e. the enslaving transformed into error compensation. Force increase magnitude had a smaller effect on the correlation coefficients. The observations support the hypothesis that the pattern of inter-finger interaction—enslaving or compensation—depends on the initial force level and, to a smaller degree, on the targeted magnitude of the force increase. They suggest that the controller views tasks with higher steady-state forces and smaller force changes as implying a requirement to avoid large changes in the total force. PMID:18985331

  19. Compilation and evaluation of gas-phase diffusion coefficients of reactive trace gases in the atmosphere: volume 2. Organic compounds and Knudsen numbers for gas uptake calculations

    NASA Astrophysics Data System (ADS)

    Tang, M. J.; Shiraiwa, M.; Pöschl, U.; Cox, R. A.; Kalberer, M.

    2015-02-01

    Diffusion of organic vapours to the surface of aerosol or cloud particles is an important step for the formation and transformation of atmospheric particles. So far, however, a database of gas phase diffusion coefficients for organic compounds of atmospheric interest has not been available. In this work we have compiled and evaluated gas phase diffusivities (pressure-independent diffusion coefficients) of organic compounds reported by previous experimental studies, and we compare the measurement data to estimates obtained with Fuller's semi-empirical method. The difference between measured and estimated diffusivities are mostly < 10%. With regard to gas-particle interactions, different gas molecules, including both organic and inorganic compounds, exhibit similar Knudsen numbers (Kn) although their gas phase diffusivities may vary over a wide range. Knudsen numbers of gases with unknown diffusivity can be approximated by a simple function of particle diameter and pressure and can be used to characterize the influence of diffusion on gas uptake by aerosol or cloud particles. We use a kinetic multi-layer model of gas-particle interaction to illustrate the effects of gas phase diffusion on the condensation of organic compounds with different volatilities. The results show that gas-phase diffusion can play a major role in determining the growth of secondary organic aerosol particles by condensation of low-volatility organic vapours.

  20. Probing the Reactivity of Dimethylsulfoxonium Methylide with Conjugated and Nonconjugated Carbonyl Compounds: An Undergraduate Experiment Combining Synthesis, Spectral Analysis, and Mechanistic Discovery

    ERIC Educational Resources Information Center

    Ciaccio, James A.; Guevara, Elena L.; Alam, Rabeka; D'agrosa, Christina D.

    2010-01-01

    We introduce students to dimethylsulfoxonium methylide (DMSY) epoxidation of aryl and nonconjugated aliphatic aldehydes and ketones without revealing that DMSY cyclopropanates enones by Michael-initiated ring closure (MIRC). Each student performs the reaction of DMSY with one of nine carbonyl compounds, including four enones, and then analyzes the…

  1. Fingerspell: Let Your Fingers Do the Talking

    ERIC Educational Resources Information Center

    Scarlatos, Tony; Nesterenko, Dmitri

    2004-01-01

    In this article we discuss an application that translates hand gestures of the American Sign Language (ASL) alphabet and converts them to text. The FingerSpell application addresses the communication barrier of the deaf and the hearing-impaired by eliminating the need for a third party with knowledge of the American Sign Language, allowing a user…

  2. Fingers Make a Comeback in Math

    ERIC Educational Resources Information Center

    Brooks, Andree

    1978-01-01

    Describes a new idea in finger-counting developed by 31 year old Hang Young Pai, a Korean teacher living in New York. It is called Chisanbop and it comes from a more advanced hand-calculation system used in the Orient in conjunction with the abacus. It is applicable for both elementary students and for more advanced mathematical applications, such…

  3. Finger arterial pressure measurement with Finapres.

    PubMed

    Wesseling, K H

    1996-01-01

    Finger arterial pressure measurement with Finapres has been available since a decade. Its availability has promoted at least 300 methodological and research papers over these years, outlining the usefulness and the limitations of the method and the device. Finapres is based on the volume clamp method of Peñáz and the Physiocal criteria of Wesseling. Tracking of intraarterial pressure is usually satisfactory even under conditions of strongly changing hemodynamics and high and very low blood pressures. Finapres accuracy is similar to that of other non-invasive methods. Systolic pressure levels scatter more than mean and diastolic levels. One source of error is physiologic and determined by the peripheral measurement site of the finger, causing pulse waveform distortion and a pressure gradient. The Finapres waveform can be filtered, however, to obtain a brachial pressure wave. This decreases systolic scatter under vaso-constrictive drug infusion and dynamic exercise to exhaustion, conditions where precision of systolic tracking has been criticized in the literature. Recently, level correction techniques were found which shift finger pressure up or down based on a regression equation with finger systolic and diastolic pressures. This procedure requires no additional measurements yet improves systolic, diastolic and mean level accuracy and precision remarkably. Finally, we show how to judge the quality of a Finapres recording from the behavior of Physiocal. PMID:8896298

  4. Viscous fingering with partial miscible fluids

    NASA Astrophysics Data System (ADS)

    Fu, Xiaojing; Cueto-Felgueroso, Luis; Juanes, Ruben

    2015-11-01

    When a less viscous fluid displaces a more viscous fluid, the contrast in viscosity destabilizes the interface between the two fluids, leading to the formation of fingers. Studies of viscous fingering have focused on fluids that are either fully miscible or perfectly immiscible. In practice, however, the miscibility of two fluids can change appreciably with temperature and pressure, and often falls into the case of partial miscibility, where two fluids have limited solubility in each other. Following our recent work for miscible (Jha et al., PRL 2011, 2013) and immiscible systems (Cueto-Felgueroso and Juanes, PRL 2012, JFM 2014), here we propose a phase-field model for fluid-fluid displacements in a Hele-Shaw cell, when the two fluids have limited (but nonzero) solubility in one another. Partial miscibility is characterized through the design of thermodynamic free energy of the two-fluid system. We elucidate the key dimensionless groups that control the behavior of the system. We present high-resolution numerical simulations of the model applied to the viscous fingering problem. On one hand, we demonstrate the effect of partial miscibility on the hydrodynamic instability. On the other, we elucidate the role of the degree of fingering on the rate of mutual fluid dissolution.

  5. Fjord geometry observed in viscous fingering*

    NASA Astrophysics Data System (ADS)

    Thrasher, Matt; Ristroph, Leif; Swinney, Harry L.; Mineev-Weinstein, Mark

    2004-11-01

    Injecting a less viscous fluid (air) into a more viscous fluid (oil) produces an unstable finger of air penetrating into the oil. For sufficiently large forcing, the tip of a finger splits. The region of oil left between adjacent fingers is called a fjord. We characterize the width, widening, and bending of fjords in experiments in a rectangular Hele-Shaw cell. The channel confines air and 50 cS silicone oil between two glass plates, which are 2500 mm long and 250 mm wide with a separation of 0.5 mm. The width of the base of a fjord is found to be approximately one-half of the capillary length scale. From this base, the fjords open with a distribution of angles having a mean of about 9 ^rc, which contradicts theoretical predictions of an opening angle of 0 ^rc (parallel sides). Finally, the centerline of a fjord bends. Lajeunesse and Couder [1] account for the bending of a fjord on a single, one-half width finger. We test the validity of their idea on the tip-splitting of more complicated interfaces and on the widening of fjords. *Supported by ONR [1] E. Lajeunesse and Y. Couder, J. Fluid. Mech. 419, 125 (2000).

  6. Fingering phenomena during grain-grain displacement

    NASA Astrophysics Data System (ADS)

    Mello, Nathália M. P.; Paiva, Humberto A.; Combe, G.; Atman, A. P. F.

    2016-05-01

    Spontaneous formation of fingered patterns during the displacement of dense granular assemblies was experimentally reported few years ago, in a radial Hele-Shaw cell. Here, by means of discrete element simulations, we have recovered the experimental findings and extended the original study to explore the control parameters space. In particular, using assemblies of grains with different geometries (monodisperse, bidisperse, or polydisperse), we measured the macroscopic stress tensor in the samples in order to confirm some conjectures proposed in analogy with Saffman-Taylor viscous fingering phenomena for immiscible fluids. Considering an axial setup which allows to control the discharge of grains and to follow the trajectory and the pressure gradient along the displacing interface, we have applied the Darcy law for laminar flow in fluids in order to measure an "effective viscosity" for each assembly combination, in an attempt to mimic variation of the viscosity ratio between the injected/displaced fluids in the Saffman-Taylor experiment. The results corroborate the analogy with the viscous fluids displacement, with the bidisperse assembly corresponding to the less viscous geometry. But, differently to fluid case, granular fingers only develop for a specific combination of displaced/injected geometries, and we have demonstrated that it is always related with the formation of a force chain network along the finger direction.

  7. Compact Tactile Sensors for Robot Fingers

    NASA Technical Reports Server (NTRS)

    Martin, Toby B.; Lussy, David; Gaudiano, Frank; Hulse, Aaron; Diftler, Myron A.; Rodriguez, Dagoberto; Bielski, Paul; Butzer, Melisa

    2004-01-01

    Compact transducer arrays that measure spatial distributions of force or pressure have been demonstrated as prototypes of tactile sensors to be mounted on fingers and palms of dexterous robot hands. The pressure- or force-distribution feedback provided by these sensors is essential for the further development and implementation of robot-control capabilities for humanlike grasping and manipulation.

  8. Sticky fingers: Adhesive properties of human fingertips.

    PubMed

    Spinner, Marlene; Wiechert, Anke B; Gorb, Stanislav N

    2016-02-29

    Fingertip friction is a rather well studied subject. Although the phenomenon of finger stickiness is known as well, the pull-off force and the adhesive strength of human finger tips have never been previously quantified. For the first time, we provided here characterization of adhesive properties of human fingers under natural conditions. Human fingers can generate a maximum adhesive force of 15mN on a smooth surface of epoxy resin. A weak correlation of the adhesive force and the normal force was found on all test surfaces. Up to 300mN load, an increase of the normal force leads to an increase of the adhesive force. On rough surfaces, the adhesive strength is significantly reduced. Our data collected from untreated hands give also an impression of an enormous scattering of digital adhesion depending on a large set of inter-subject variability and time-dependent individual factors (skin texture, moisture level, perspiration). The wide inter- and intra-individual range of digital adhesion should be considered in developing of technical and medical products. PMID:26892897

  9. Finger force perception during ipsilateral and contralateral force matching tasks

    PubMed Central

    Park, Woo-Hyung; Leonard, Charles T.; Li, Sheng

    2010-01-01

    The aims of the present study were to compare matching performance between ipsilateral and contralateral finger force matching tasks and to examine the effect of handedness on finger force perception. Eleven subjects were instructed to produce reference forces by an instructed finger (index – I or little – L finger) and to reproduce the same amount force by the same or a different finger within the hand (i.e., ipsilateral matching task), or by a finger of the other hand (i.e., contralateral matching task). The results of the ipsilateral and contralateral tasks in the present study commonly showed that 1) the reference and matching forces were matched closely when the two forces were produced by the same or homologous finger(s) such as I/I task; 2) the weaker little finger underestimated the magnitude of reference force of the index finger (I/L task), even with the higher level of effort (relative force), but the two forces were matched when considering total finger forces; 3) the stronger index finger closely matched the reference force of the little finger with the lower level of relative force (i.e., L/I task); 4) when considering the constant errors, I/L tasks showed an underestimation and L/I tasks showed an overestimation compared to I/I tasks. There was no handedness effect during ipsilateral tasks. During the contralateral task, the dominant hand overestimated the force of the non-dominant hand, while the non-dominant hand attempted to match the absolute force of the dominant hand. The overall results support the notion that the absolute, rather than relative, finger force is perceived and reproduced during ipsilateral and contralateral finger force matching tasks, indicating the uniqueness of finger force perception. PMID:18488212

  10. Effect of olive mill wastewater phenol compounds on reactive carbonyl species and Maillard reaction end-products in ultrahigh-temperature-treated milk.

    PubMed

    Troise, Antonio Dario; Fiore, Alberto; Colantuono, Antonio; Kokkinidou, Smaro; Peterson, Devin G; Fogliano, Vincenzo

    2014-10-15

    Thermal processing and Maillard reaction (MR) affect the nutritional and sensorial qualities of milk. In this paper an olive mill wastewater phenolic powder (OMW) was tested as a functional ingredient for inhibiting MR development in ultrahigh-temperature (UHT)-treated milk. OMW was added to milk at 0.1 and 0.05% w/v before UHT treatment, and the concentration of MR products was monitored to verify the effect of OMW phenols in controlling the MR. Results revealed that OMW is able to trap the reactive carbonyl species such as hydroxycarbonyls and dicarbonyls, which in turn led to the increase of Maillard-derived off-flavor development. The effect of OMW on the formation of Amadori products and N-ε-(carboxymethyl)-lysine (CML) showed that oxidative cleavage, C2-C6 cyclization, and the consequent reactive carbonyl species formation were also inhibited by OMW. Data indicated that OMW is a functional ingredient able to control the MR and to improve the nutritional and sensorial attributes of milk. PMID:25280240

  11. Setting tool with retractable torque fingers

    SciTech Connect

    Nevels, D.L.; Baugh, J.L.

    1986-07-08

    A method is described of setting a liner in a well bore using a setting tool of the type adapted to be made up in a pipe string for releasably engaging a setting sleeve in a well bore, comprising the steps of: connecting a mandrel in the pipe string which has a setting nut with external connecting threads for engaging mating connecting threads located on the interior of a setting sleeve disposed about the mandrel, the mandrel being slidably disposed within the setting nut when the setting nut is engaging the setting sleeve, the mandrel being slidable between an extended, running-in position and a weight set-down position; mounting a torque collar on the mandrel exterior, the torque collar having at least one torque finger mounted thereon which is axially slidable on an external surface of the torque collar in a plane which is parallel to the longitudinal axis of the tool, the setting sleeve having at least one end notch adapted to receive the axially slidable torque finger; initially latching the mandrel to the setting sleeve with each torque finger received within its respective end notch; setting weight down on the pipe string from the well surface to release the latch and allow relative movement between the connecting threads of the setting nut and setting sleeve; applying right hand torque to the pipe string to release the connecting threads of the setting nut from the setting sleeve; temporarily lifting the pipe string and setting tool to test the disengagement of the setting nut; again resting the setting tool on the setting sleeve; rotating the pipe string to realign the torque finger and the setting sleeve end notch and reengage the torque finger with the end notch; and continuing to rotate to the right to rotate the setting sleeve during subsequent well bore operations.

  12. 21 CFR 888.3230 - Finger joint polymer constrained prosthesis.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Finger joint polymer constrained prosthesis. 888... SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3230 Finger joint polymer constrained prosthesis. (a) Identification. A finger joint polymer constrained prosthesis is a device...

  13. 21 CFR 888.3230 - Finger joint polymer constrained prosthesis.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Finger joint polymer constrained prosthesis. 888... SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3230 Finger joint polymer constrained prosthesis. (a) Identification. A finger joint polymer constrained prosthesis is a device...

  14. A dowel exercise tool to improve finger range of motion.

    PubMed

    Zavala, Paul

    2014-01-01

    A new clinical and home dowel exercise tool to reduce joint stiffness of the fingers is introduced, along with the fabrication and the exercises that are used with it. Patients may utilize it to improve their finger joint range of motion, and facilitate tendon glide by isolating the targeted stiff joints of the fingers. PMID:24044953

  15. Robot-assisted Guitar Hero for finger rehabilitation after stroke.

    PubMed

    Taheri, Hossein; Rowe, Justin B; Gardner, David; Chan, Vicky; Reinkensmeyer, David J; Wolbrecht, Eric T

    2012-01-01

    This paper describes the design and testing of a robotic device for finger therapy after stroke: FINGER (Finger Individuating Grasp Exercise Robot). FINGER makes use of stacked single degree-of-freedom mechanisms to assist subjects in moving individual fingers in a naturalistic grasping pattern through much of their full range of motion. The device has a high bandwidth of control (-3dB at approximately 8 Hz) and is backdriveable. These characteristics make it capable of assisting in grasping tasks that require precise timing. We therefore used FINGER to assist individuals with a stroke (n= 8) and without impairment (n= 4) in playing a game similar to Guitar Hero©. The subjects attempted to move their fingers to target positions at times specified by notes that were graphically streamed to popular music. We show here that by automatically adjusting the robot gains, it is possible to use FINGER to modulate the subject's success rate at the game, across a range of impairment levels. Modulating success rates did not alter the stroke subject's effort, although the unimpaired subjects exerted more force when they were made less successful. We also present a novel measure of finger individuation that can be assessed as individuals play Guitar Hero with FINGER. The results demonstrate the ability of FINGER to provide controlled levels of assistance during an engaging computer game, and to quantify finger individuation after stroke. PMID:23366783

  16. Pressure Balanced, Low Hysteresis Finger Seal Test Results

    NASA Technical Reports Server (NTRS)

    Arora, Gul K.; Proctor, Margaret; Steinetz, Bruce M.; Delgado, Irebert R.

    2000-01-01

    The purpose of this presentation is to demonstrate: low cost photoetching fabrication technique; pressure balanced finger seal design; and finger seal operation. The tests and analyses includes: finger seal air leakage analysis; rotor-run out and endurance tests; and extensive analytical work and rig testing.

  17. 21 CFR 888.3230 - Finger joint polymer constrained prosthesis.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Finger joint polymer constrained prosthesis. 888... SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3230 Finger joint polymer constrained prosthesis. (a) Identification. A finger joint polymer constrained prosthesis is a device...

  18. 21 CFR 888.3230 - Finger joint polymer constrained prosthesis.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Finger joint polymer constrained prosthesis. 888... SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3230 Finger joint polymer constrained prosthesis. (a) Identification. A finger joint polymer constrained prosthesis is a device...

  19. Left hand finger force in violin playing: tempo, loudness, and finger differences.

    PubMed

    Kinoshita, Hiroshi; Obata, Satoshi

    2009-07-01

    A three-dimensional force transducer was installed in the neck of a violin under the A string at the D5 position in order to study the force with which the violinist clamps the string against the fingerboard under normal playing conditions. Violinists performed repetitive sequences of open A- and fingered D-tones using the ring finger at tempi of 1, 2, 4, 8, and 16 notes/s at mezzo-forte. At selected tempi, the effects of dynamic level and the use of different fingers were investigated as well. The force profiles were clearly dependent on tempo and dynamic level. At slow tempi, the force profiles were characterized by an initial pulse followed by a level force to the end of the finger contact period. At tempi higher than 2 Hz, only pulsed profiles were observed. The peak force exceeded 4.5 N at 1 and 2 Hz and decreased to 1.7 N at 16 Hz. All force and impulse values were lower at softer dynamic levels, and when using the ring or little finger compared to the index finger. PMID:19603895

  20. The influence of radiation-induced vacancy on the formation of thin-film of compound layer during a reactive diffusion process

    NASA Astrophysics Data System (ADS)

    Akintunde, S. O.; Selyshchev, P. A.

    2016-05-01

    A theoretical approach is developed that describes the formation of a thin-film of AB-compound layer under the influence of radiation-induced vacancy. The AB-compound layer is formed as a result of a chemical reaction between the atomic species of A and B immiscible layers. The two layers are irradiated with a beam of energetic particles and this process leads to several vacant lattice sites creation in both layers due to the displacement of lattice atoms by irradiating particles. A- and B-atoms diffuse via these lattice sites by means of a vacancy mechanism in considerable amount to reaction interfaces A/AB and AB/B. The reaction interfaces increase in thickness as a result of chemical transformation between the diffusing species and surface atoms (near both layers). The compound layer formation occurs in two stages. The first stage begins as an interfacial reaction controlled process, and the second as a diffusion controlled process. The critical thickness and time are determined at a transition point between the two stages. The influence of radiation-induced vacancy on layer thickness, speed of growth, and reaction rate is investigated under irradiation within the framework of the model presented here. The result obtained shows that the layer thickness, speed of growth, and reaction rate increase strongly as the defect generation rate rises in the irradiated layers. It also shows the feasibility of producing a compound layer (especially in near-noble metal silicide considered in this study) at a temperature below their normal formation temperature under the influence of radiation.

  1. Synthesis, Reactivity Investigation, and X-ray Diffraction Structures of New Platinum(II) Compounds Containing Redox-Active Diphosphine Ligands

    SciTech Connect

    Wang, Xiaoping; Richmond, Michael G.; Hunt, Sean W

    2009-01-01

    Substitution of the 1,5-cyclooctadiene (cod) ligand in PtCl2(cod) (1) by the diphosphine ligand 4,5-bis(diphenylphosphino)-4-cyclopenten-1,3-dione (bpcd) yields PtCl2(bpcd) (2). Knoevenagel condensation of 2 with 9-anthracenecarboxaldehyde leads to the functionalization of the bpcd ligand and formation of the corresponding 2-(9-anthracenylidene)-4,5-bis(diphenylphosphino)-4-cyclopenten-1,3-dione (abpcd) substituted compound PtCl2(abpcd) (3), which is also obtained from the direct reaction of 1 with the abpcd ligand in near quantitative yield. The reaction of 3 with disodium maleonitriledithiolate (Na2mnt) affords the chelating dithiolate compound Pt(mnt)(abpcd) (4). Compounds 2 C4 have been fully characterized in solution by IR and NMR spectroscopies (1H and 31P), and their molecular structures established by X-ray crystallography. The electrochemical properties of 2 C4 have examined by cyclic voltammetry, and the nature of the HOMO and LUMO levels in these systems has been established by MO calculations at the extended H ckel level, the results of which are discussed with respect to electrochemical data and related diphosphine derivatives.

  2. Determination of direct photolysis rate constants and OH radical reactivity of representative odour compounds in brewery broth using a continuous flow-stirred photoreactor

    NASA Astrophysics Data System (ADS)

    Jürgens, Marion; Jacob, Fritz; Ekici, Perihan; Friess, Albrecht; Parlar, Harun

    A method based on photolysis was developed for the appropriate treatment of organic pollutants in air exhausting from breweries upon wort decoction, and thereby causing smell nuisance. A continuous flow stirred photoreactor was built-up exclusively, allowing OH radicals to react with selected odorous compounds contained in exhaust vapours, such as: 2-methylpropanal, 3-methylbutanal, 2-methylbutanal, 3-methyl-1-butanol, n-hexanal, 2-methylbutyl isobutyrate, 2-undecanone, phenyl acetaldehyde, myrcene, limonene, linalool, humulene, dimethylsulphide, and dimethyltrisulphide. These substances were quantified in brewery broth before and after UV irradiation using high-resolution gas chromatography-mass spectrometry (HRGC-MS). For odour analysis, high-resolution gas chromatography-flame ionisation detection (HRGC-FID) coupled with sensory methods was used. Determined quantum yields of about 10 -3 for phenyl acetaldehyde, myrcene, and humulene pointed out that direct photolysis contributed to their decay. Quantum yields of below 10 -4 for the other substances indicated that UV irradiation did not contribute significantly to their degradation processes. Hydroxyl radical reaction rate constants and Henry constants of organic compounds were also measured. Substances accompanied with low Henry constants converted rapidly, whereas those with higher ones, relatively slowly. Determined aroma values concluded that after UV-H 2O 2 treatment, only dimethylsulphide and myrcene remained as important odorous compounds, but in significantly reduced concentrations. The UV-H 2O 2 treatment of brewery broth has been proved effective to reduce smell-irritating substances formed upon wort decoction.

  3. Involvement of 5f-orbitals in the bonding and reactivity of organoactinide compounds: thorium(IV) and uranium(IV) bis (hydrazonato) complexes

    SciTech Connect

    Cantat, Thibault; Graves, Christopher R; Morris, David E; Kiplinger, Jaqueline L

    2008-01-01

    Migratory insertion of diphenyldiazomethane into both metal-carbon bonds of the bis(alkyl) and bis(aryl) complexes (C5Me5)2AnR2 yields the first f-element bis(hydrazonato) complexes (C5Me5)2An[2-(N,N')-R-N-NCPh2]2 [An = Th, R = CH3 (18), PhCH2 (15), Ph (16); An = U, R = CH3 (17), PhCH2 (14)], which have been characterized by a combination of spectroscopy, electrochemistry, and X-ray crystallography. The two hydrazonato ligands adopt an 2-coordination mode leading to 20-electron (for Th) and 22-electron (for U) complexes that have no transition-metal analogues. In fact, reaction of (C5H5)2Zr(CH3)2 or (C5Me5)2Hf(CH3)2 with diphenyldiazomethane is limited to the formation of the corresponding mono(hydrazonato) complex (C5R5)2M[2-(N,N')-CH3-N-NCPh2](CH3) (M = Zr, R = H or M = Hf, R = CH3). The difference in the reactivities of the group 4 metal complexes and the actinides was used as a unique platform for investigating in depth the role of 5f orbitals on the reactivity and bonding in actinide organometallic complexes. The electronic structure of the (C5H5)2M[2-(N,N')-CH3-N-NCH2]2 (M = Zr, Th, U) model complexes was studied using density functional theory (DFT) calculations and compared to experimental structural, electrochemical, and spectroscopic results. Whereas transition-metal bis(cyclopentadienyl) complexes are known to stabilize three ligands in the metallocene girdle to form saturated (C5H5)2ML3 species, in a bis(hydrazonato) system, a fourth ligand is coordinated to the metal center to give (C5H5)2ML4. DFT calculations have shown that 5f orbitals in the actinide complexes play a crucial role in stabilizing this fourth ligand by stabilizing both the s and p electrons of the two 2-coordinated hydrazonato ligands. In contrast, the stabilization of the hydrazonato ligands was found to be significantly less effective for the putative bis(hydrazonato) zirconium(IV) complex, yielding a higher energy structure. However, the difference in the reactivities of the group 4

  4. Chicken Fetal Liver DNA Damage and Adduct Formation by Activation-Dependent DNA-Reactive Carcinogens and Related Compounds of Several Structural Classes

    PubMed Central

    Williams, Gary M.; Duan, Jian-Dong; Brunnemann, Klaus D.; Iatropoulos, Michael J.; Vock, Esther; Deschl, Ulrich

    2014-01-01

    The chicken egg genotoxicity assay (CEGA), which utilizes the liver of an intact and aseptic embryo-fetal test organism, was evaluated using four activation-dependent DNA-reactive carcinogens and four structurally related less potent carcinogens or non-carcinogens. In the assay, three daily doses of test substances were administered to eggs containing 9–11-day-old fetuses and the fetal livers were assessed for two endpoints, DNA breaks using the alkaline single cell gel electrophoresis (comet) assay and DNA adducts using the 32P-nucleotide postlabeling (NPL) assay. The effects of four carcinogens of different structures requiring distinct pathways of bioactivation, i.e., 2-acetylaminofluorene (AAF), aflatoxin B1 (AFB1), benzo[a]pyrene (B[a]P), and diethylnitrosamine (DEN), were compared with structurally related non-carcinogens fluorene (FLU) and benzo[e]pyrene (B[e]P) or weak carcinogens, aflatoxin B2 (AFB2) and N-nitrosodiethanolamine (NDELA). The four carcinogens all produced DNA breaks at microgram or low milligram total doses, whereas less potent carcinogens and non-carcinogens yielded borderline or negative results, respectively, at higher doses. AAF and B[a]P produced DNA adducts, whereas none was found with the related comparators FLU or B[e]P, consistent with comet results. DEN and NDELA were also negative for adducts, as expected in the case of DEN for an alkylating agent in the standard NPL assay. Also, AFB1 and AFB2 were negative in NPL, as expected, due to the nature of ring opened aflatoxin adducts, which are resistant to enzymatic digestion. Thus, the CEGA, using comet and NPL, is capable of detection of the genotoxicity of diverse DNA-reactive carcinogens, while not yielding false positives for non-carcinogens. PMID:24973097

  5. Assessment of the roles of reactive oxygen species in the UV and visible light photocatalytic degradation of cyanotoxins and water taste and odor compounds using C-TiO2.

    PubMed

    Fotiou, Theodora; Triantis, Theodoros M; Kaloudis, Triantafyllos; O'Shea, Kevin E; Dionysiou, Dionysios D; Hiskia, Anastasia

    2016-03-01

    Visible light (VIS) photocatalysis has large potential as a sustainable water treatment process, however the reaction pathways and degradation processes of organic pollutants are not yet clearly defined. The presence of cyanobacteria cause water quality problems since several genera can produce potent cyanotoxins, harmful to human health. In addition, cyanobacteria produce taste and odor compounds, which pose serious aesthetic problems in drinking water. Although photocatalytic degradation of cyanotoxins and taste and odor compounds have been reported under UV-A light in the presence of TiO2, limited studies have been reported on their degradation pathways by VIS photocatalysis of these problematic compounds. The main objectives of this work were to study the VIS photocatalytic degradation process, define the reactive oxygen species (ROS) involved and elucidate the reaction mechanisms. We report carbon doped TiO2 (C-TiO2) under VIS leads to the slow degradation of cyanotoxins, microcystin-LR (MC-LR) and cylindrospermopsin (CYN), while taste and odor compounds, geosmin and 2-methylisoborneol, were not appreciably degraded. Further studies were carried-out employing several specific radical scavengers (potassium bromide, isopropyl alcohol, sodium azide, superoxide dismutase and catalase) and probes (coumarin) to assess the role of different ROS (hydroxyl radical OH, singlet oxygen (1)O2, superoxide radical anion [Formula: see text] ) in the degradation processes. Reaction pathways of MC-LR and CYN were defined through identification and monitoring of intermediates using liquid chromatography tandem mass spectrometry (LC-MS/MS) for VIS in comparison with UV-A photocatalytic treatment. The effects of scavengers and probes on the degradation process under VIS, as well as the differences in product distributions under VIS and UV-A, suggested that the main species in VIS photocatalysis is [Formula: see text] , with OH and (1)O2 playing minor roles in the degradation. PMID

  6. The Shape of a Gravity Finger

    SciTech Connect

    Zhan, Lang; Yortsos, Yanis

    2000-09-11

    A new gravity finger model was proposed in this report in the absence of interfacial tension but in the presence of gravities. This model considered differences in density and viscosity of the two fluids. Thus, it was able to represent both stable and unstable displacements, and the finger development along either the upper or the bottom walls of a channel. This solution recovers the Saffman - Taylar solution if gravity is neglected. The results of the solution are very similar to the solutions proposed by Brener et al. for the gravity number up to 10. The solution provided in this work only has one free parameter while the solution of Brener et al. has three.

  7. Nylon-muscle-actuated robotic finger

    NASA Astrophysics Data System (ADS)

    Wu, Lianjun; Jung de Andrade, Monica; Rome, Richard S.; Haines, Carter; Lima, Marcio D.; Baughman, Ray H.; Tadesse, Yonas

    2015-04-01

    This paper describes the design and experimental analysis of novel artificial muscles, made of twisted and coiled nylon fibers, for powering a biomimetic robotic hand. The design is based on circulating hot and cold water to actuate the artificial muscles and obtain fast finger movements. The actuation system consists of a spring and a coiled muscle within a compliant silicone tube. The silicone tube provides a watertight, expansible compartment within which the coiled muscle contracts when heated and expands when cooled. The fabrication and characterization of the actuating system are discussed in detail. The performance of the coiled muscle fiber in embedded conditions and the related characteristics of the actuated robotic finger are described.

  8. Articular synovial chondromatosis of the finger.

    PubMed

    Sano, Kazufumi; Hashimoto, Tomohisa; Kimura, Kazumasa; Ozeki, Satoru

    2014-10-01

    A 40-year-old woman presented with a six-month history of synovial chondromatosis of the metacarpophalangeal joint of the right ring finger, which was resected through both dorsal and volar incisions. To our knowledge there have been only 17 reported cases of articular synovial chondromatosis of the digital joint so far. We present a case affecting the metacarpophalangeal joint with a review of scattered information found in other 17 reports. PMID:23596991

  9. Low-Friction Joint for Robot Fingers

    NASA Technical Reports Server (NTRS)

    Ruoff, C. F.

    1985-01-01

    Mechanical linkage allows adjacent parts to move relative to each other with low friction and with no chatter, slipping, or backlash. Low-friction joint of two surfaces in rolling contact, held in alinement by taut flexible bands. No sliding friction or "stick-slip" motion: Only rolling-contact and bending friction within bands. Proposed linkage intended for finger joints in mechanical hands for robots and manipulators.

  10. The reaction of pristane (2,6,10,14-tetramethylpentadecane) with radiolytically generated reactive oxygen intermediates results in a stable genotoxic compound as assessed by the SOS chromotest.

    PubMed

    Janz, S; Brede, O; Müller, J

    1991-07-01

    The most widely studied model of plasmacytomagenesis is the induction of plasmacytomas in BALB/c mice by i.p. injections of the isoalkane pristane (2,6,10,14-tetramethylpentadecane). Employing a simple quantitative and well-established short-term bacterial genotoxicity assay, the SOS chromotest, as a model system, we have investigated whether pristane may potentially be involved in causing or modulating the genotoxic events thought to induce plasma cell tumorigenesis. We found that incorporation of pristane into the cell membranes enhance the SOS response in Escherichia coli PQ37 and PQ300 induced by gamma-radiation under hyperoxic conditions. Moreover, the oxidation of pristane by radiolytically generated reactive oxygen intermediates yielded a stable, genotoxic product active on E. coli PQ300, a SOS tester strain designed to detect oxidative genotoxins. We discuss these findings in relation to the tumor-promoting role of the chronic i.p. inflammation that accompanies plasmacytomagenesis and conclude that, under these specific conditions, pristane may possess a previously unrecognized genotoxic activity in its tumorigenic potential. PMID:2070489

  11. Recent advances in high performance poly(lactide): from “green” plasticization to super-tough materials via (reactive) compounding

    PubMed Central

    Kfoury, Georgio; Raquez, Jean-Marie; Hassouna, Fatima; Odent, Jérémy; Toniazzo, Valérie; Ruch, David; Dubois, Philippe

    2013-01-01

    Due to its origin from renewable resources, its biodegradability, and recently, its industrial implementation at low costs, poly(lactide) (PLA) is considered as one of the most promising ecological, bio-sourced and biodegradable plastic materials to potentially and increasingly replace traditional petroleum derived polymers in many commodity and engineering applications. Beside its relatively high rigidity [high tensile strength and modulus compared with many common thermoplastics such as poly(ethylene terephthalate) (PET), high impact poly(styrene) (HIPS) and poly(propylene) (PP)], PLA suffers from an inherent brittleness, which can limit its applications especially where mechanical toughness such as plastic deformation at high impact rates or elongation is required. Therefore, the curve plotting stiffness vs. impact resistance and ductility must be shifted to higher values for PLA-based materials, while being preferably fully bio-based and biodegradable upon the application. This review aims to establish a state of the art focused on the recent progresses and preferably economically viable strategies developed in the literature for significantly improve the mechanical performances of PLA. A particular attention is given to plasticization as well as to impact resistance modification of PLA in the case of (reactive) blending PLA-based systems. PMID:24790960

  12. Vibration white finger: a follow up study.

    PubMed Central

    Ekenvall, L; Carlsson, A

    1987-01-01

    To study the course of vibration white finger (VWF) 55 men were re-examined three and a half to six years after the first examination. The patients were interviewed and finger systolic pressure after general body and local finger cooling was measured. The test results at the two examinations were compared. At the follow up examination some patients experienced a subjective improvement of VWF symptoms but not until more than three years had passed after they had stopped working with vibrating tools. To study the effect of diminished cold exposure on subjective symptoms, vibration exposed outdoor workers who changed to unexposed indoor work were studied separately. In this subgroup also improvement was reported only when more than three years has passed after the change of work, indicating that diminished cold exposure is not the primary explanation for the improvement. The cold provocation test, however, showed no tendency towards a diminished reaction of the vessels to cooling. Patients who continue to work with vibrating tools report a subjective increase in symptoms. This subjective impairment was reflected in an increased reaction to cold as measured in the cold provocation test. PMID:3620371

  13. Visual Foraging With Fingers and Eye Gaze

    PubMed Central

    Thornton, Ian M.; Smith, Irene J.; Chetverikov, Andrey; Kristjánsson, Árni

    2016-01-01

    A popular model of the function of selective visual attention involves search where a single target is to be found among distractors. For many scenarios, a more realistic model involves search for multiple targets of various types, since natural tasks typically do not involve a single target. Here we present results from a novel multiple-target foraging paradigm. We compare finger foraging where observers cancel a set of predesignated targets by tapping them, to gaze foraging where observers cancel items by fixating them for 100 ms. During finger foraging, for most observers, there was a large difference between foraging based on a single feature, where observers switch easily between target types, and foraging based on a conjunction of features where observers tended to stick to one target type. The pattern was notably different during gaze foraging where these condition differences were smaller. Two conclusions follow: (a) The fact that a sizeable number of observers (in particular during gaze foraging) had little trouble switching between different target types raises challenges for many prominent theoretical accounts of visual attention and working memory. (b) While caveats must be noted for the comparison of gaze and finger foraging, the results suggest that selection mechanisms for gaze and pointing have different operational constraints. PMID:27433323

  14. Pacifier Use, Finger Sucking, and Infant Sleep.

    PubMed

    Butler, Rachel; Moore, Melisa; Mindell, Jodi A

    2016-01-01

    Few studies to date have investigated the relationship between pacifier use or finger sucking and infant sleep. One hundred and four mothers of infants (ages 0-11 months) completed the Brief Infant Sleep Questionnaire (BISQ). Infants who engaged in finger sucking had fewer night wakings and longer stretches of nighttime sleep, although less daytime sleep. There were no significant differences in sleep patterns between pacifier users and infants who did not engage in nonnutritive sucking. Furthermore, no significant differences were found across groups for sleep ecology, including parental involvement at bedtime and following night wakings. Finally, infants were consistently able to retrieve their pacifiers independently by 7 months of age, although this did not appear to be associated with sleep outcomes. Results suggest that when parents are deciding whether to give their infant a pacifier, sleep may not be a critical factor. In contrast, parents of finger and thumb suckers should be reassured that this nonnutritive sucking is beneficial to sleep, at least in the first year of life. PMID:26548755

  15. Multi-finger Prehension: An overview

    PubMed Central

    Zatsiorsky, Vladimir M.; Latash, Mark L.

    2009-01-01

    This paper reviews the available experimental evidence on what people do when they grasp an object with several digits and then manipulate it. In addition to the Introduction, the paper includes three parts each addressing a specific aspect of multi-finger prehension. Part II discusses manipulation forces, i.e. the resultant force and moment of force exerted on the object, and the digits contribution to such force production. Part III deals with internal forces defined as forces that cancel each other and do not disturb object equilibrium. The role of the internal forces in maintaining the object stability is discussed with respect to such issues as slip prevention, tilt prevention and resistance to perturbations. Part IV is devoted to the motor control of prehension. It covers such topics as prehension synergies, chain effects, the principle of superposition, inter-finger connection matrices and reconstruction of neural commands, mechanical advantage of the fingers, and the simultaneous digit adjustment to several mutually reinforcing or conflicting demands. PMID:18782719

  16. Palm to Finger Ulnar Sensory Nerve Conduction

    PubMed Central

    Davidowich, Eduardo; Orsini, Marco; Pupe, Camila; Pessoa, Bruno; Bittar, Caroline; Pires, Karina Lebeis; Bruno, Carlos; Coutinho, Bruno Mattos; de Souza, Olivia Gameiro; Ribeiro, Pedro; Velasques, Bruna; Bittencourt, Juliana; Teixeira, Silmar; Bastos, Victor Hugo

    2015-01-01

    Ulnar neuropathy at the wrist (UNW) is rare, and always challenging to localize. To increase the sensitivity and specificity of the diagnosis of UNW many authors advocate the stimulation of the ulnar nerve (UN) in the segment of the wrist and palm. The focus of this paper is to present a modified and simplified technique of sensory nerve conduction (SNC) of the UN in the wrist and palm segments and demonstrate the validity of this technique in the study of five cases of type III UNW. The SNC of UN was performed antidromically with fifth finger ring recording electrodes. The UN was stimulated 14 cm proximal to the active electrode (the standard way) and 7 cm proximal to the active electrode. The normal data from amplitude and conduction velocity (CV) ratios between the palm to finger and wrist to finger segments were obtained. Normal amplitude ratio was 1.4 to 0.76. Normal CV ratio was 0.8 to 1.23.We found evidences of abnormal SNAP amplitude ratio or substantial slowing of UN sensory fibers across the wrist in 5 of the 5 patients with electrophysiological-definite type III UNW. PMID:26788268

  17. Development of Prediction Models for the Reactivity of Organic Compounds with Ozone in Aqueous Solution by Quantum Chemical Calculations: The Role of Delocalized and Localized Molecular Orbitals.

    PubMed

    Lee, Minju; Zimmermann-Steffens, Saskia G; Arey, J Samuel; Fenner, Kathrin; von Gunten, Urs

    2015-08-18

    Second-order rate constants (kO3) for the reaction of ozone with micropollutants are essential parameters for the assessment of micropollutant elimination efficiency during ozonation in water and wastewater treatment. Prediction models for kO3 were developed for aromatic compounds, olefins, and amines by quantum chemical molecular orbital calculations employing ab initio Hartree-Fock (HF) and density functional theory (B3LYP) methods. The kO3 values for aromatic compounds correlated well with the energy of a delocalized molecular orbital first appearing on an aromatic ring (i.e., the highest occupied molecular orbital (HOMO) or HOMO-n (n ≥ 0) when the HOMO is not located on the aromatic ring); the number of compounds tested (N) was 112, and the correlation coefficient (R(2)) values were 0.82-1.00. The kO3 values for olefins and amines correlated well with the energy of a localized molecular orbital (i.e., the natural bond orbital (NBO)) energy of the carbon-carbon π bond of olefins (N = 45, R(2) values of 0.82-0.85) and the NBO energy of the nitrogen lone-pair electrons of amines (N = 59, R(2) values of 0.81-0.83), respectively. Considering the performance of the kO3 prediction model and the computational costs, the HF/6-31G method is recommended for all aromatic groups and olefins investigated herein, whereas the HF/MIDI!, HF/6-31G*, or HF/6-311++G** methods are recommended for amines. Based on their mean absolute errors, the above models could predict kO3 within a factor of 4, on average, relative to the experimentally determined values. Overall, good correlations were also observed (R(2) values of 0.77-0.96) between kO3 predictions by quantum molecular orbital descriptors in this study and by the Hammett (σ) and Taft (σ*) constants from previously developed quantitative structure-activity relationship (QSAR) models. Hence, the quantum molecular orbital descriptors are an alternative to σ and σ*-values in QSAR applications and can also be utilized to

  18. The creation of the artificial RING finger from the cross-brace zinc finger by {alpha}-helical region substitution

    SciTech Connect

    Miyamoto, Kazuhide; Togiya, Kayo

    2010-04-16

    The creation of the artificial RING finger as ubiquitin-ligating enzyme (E3) has been demonstrated. In this study, by the {alpha}-helical region substitution between the EL5 RING finger and the Williams-Beuren syndrome transcription factor (WSTF) PHD finger, the artificial E3 (WSTF PHD{sub R}ING finger) was newly created. The experiments of the chemical modification of residues Cys and the circular dichroism spectra revealed that the WSTF PHD{sub R}ING finger binds two zinc atoms and adopts the zinc-dependent ordered-structure. In the substrate-independent ubiquitination assay, the WSTF PHD{sub R}ING finger functions as E3 and was poly- or mono-ubiquitinated. The present strategy is very simple and convenient, and consequently it might be widely applicable to the creation of various artificial E3 RING fingers with the specific ubiquitin-conjugating enzyme (E2)-binding capability.

  19. Viscous fingering with partially miscible fluids

    NASA Astrophysics Data System (ADS)

    Fu, X.; Cueto-Felgueroso, L.; Juanes, R.

    2015-12-01

    When a less viscous fluid displaces a more viscous fluid, the contrast in viscosity destabilizes the interface between the two fluids, leading to the formation of fingers. Experimental and numerical studies of viscous fingering have focused on fluids that are either fully miscible (e.g. water and glycerol) or perfectly immiscible (e.g. water and oil). In practice, however, the miscibility of two fluids can change appreciably with temperature and pressure, and often falls into the case of partial miscibility, where two fluids have limited solubility in each other (e.g. CO2 and water). Following our recent work for miscible systems (Jha et al., PRL 2011, 2013) and immiscible systems (Cueto-Felgueroso and Juanes, PRL 2012, JFM 2014), here we propose a phase-field model for fluid-fluid displacements in a porous medium, when the two fluids have limited (but nonzero) solubility in one another. In our model, partial miscibility is characterized through the design of the thermodynamic free energy of the two-fluid system. We express the model in dimensionless form and elucidate the key dimensionless groups that control the behavior of the system. We present high-resolution numerical simulations of the model applied to the viscous fingering problem. On one hand, we demonstrate the effect of partial miscibility on the hydrodynamic instability. On the other, we elucidate the role of the degree of fingering on the rate of mutual fluid dissolution. Figure caption: final snapshots in simulations of viscous fingering with a two-fluid system mimicking that of CO2 and water. The colormap corresponds to the concentration of CO2. A band of less viscous gas phase rich in CO2 (red) displaces through the more viscous liquid phase that is undersaturated with CO2 (blue). At the fluid interface, an exchange of CO2 occurs as a result of local chemical potentials that drives the system towards thermodynamic equilibrium. This results in a shrinkage of gas phase as well as a local increase in

  20. Versatile Reactivity and Theoretical Evaluation of Mono- and Dinuclear Oxidovanadium(V) Compounds of Aroylazines: Electrogeneration of Mixed-Valence Divanadium(IV,V) Complexes.

    PubMed

    Dash, Subhashree P; Roy, Satabdi; Mohanty, Monalisa; Carvalho, M Fernanda N N; Kuznetsov, Maxim L; Pessoa, João Costa; Kumar, Amit; Patil, Yogesh P; Crochet, Aurélien; Dinda, Rupam

    2016-09-01

    The substituted hydrazones H2L(1-4) (L(1-4) = dibasic tridentate ONO(2-) donor ligands) obtained by the condensation of 2-hydroxy-1-naphthaldehyde and 2-aminobenzoylhydrazine (H2hnal-abhz) (H2L(1)) , 2-hydroxy-1-naphthaldehyde and 2-hydroxybenzoylhydrazine (H2hnal-hbhz) (H2L(2)), 2-hydroxy-1-acetonaphthone and benzoylhydrazine (H2han-bhz) (H2L(3)), or 2-hydroxy-1-acetonaphthone and 2-aminobenzoylhydrazine (H2han-abhz) (H2L(4)) are prepared and characterized. Reaction of ammonium vanadate with the appropriate H2L(1-4) results in the formation of oxidoethoxidovanadium(V) [V(V)O(OEt)(L(1-4))] (1-4) complexes. All compounds are characterized in the solid state and in solution by spectroscopic techniques (IR, UV-vis, (1)H, (13)C, and (51)V NMR, and electrospray ionization mass spectrometry). Single-crystal X-ray diffraction analysis of 1, 3, and 4 confirms the coordination of the corresponding ligands in the dianionic (ONO(2-)) enolate tautomeric form. In solution, the structurally characterized [V(V)O(OEt)(L)] compounds transform into the monooxido-bridged divanadium(V,V) [(V(V)OL)2-μ-O] complexes, with the processes being studied by IR and (1)H, (13)C, and (51)V NMR. The density functional theory (DFT) calculated Gibbs free energy of reaction 2[V(V)O(OEt)(L(4))] + H2O ⇆ [(V(V)OL(4))2-μ-O] + 2EtOH is only 2-3 kcal mol(-1), indicating that the dinuclear complexes may form in a significant amount. The electrochemical behavior of the complexes is investigated by cyclic voltammetry, with the V(V)-V(IV) E1/2(red) values being in the range 0.27-0.44 V (vs SCE). Upon controlled potential electrolysis, the corresponding (L)(O)V(IV)-O-V(V)(O)(L) mixed-valence species are obtained upon partial reduction of the [(V(V)OL)2-μ-O] complexes formed in solution, and some spectroscopic characteristics of these dinuclear mixed-valence complexes are investigated using DFT calculations and by electron paramagnetic resonance (EPR), with the formation of V(IV)-O-V(V) species being

  1. Speed invariance of independent control of finger movements in pianists

    PubMed Central

    Soechting, John F.

    2012-01-01

    Independent control of finger movements characterizes skilled motor behaviors such as tool use and musical performance. The purpose of the present study was to identify the effect of movement frequency (tempo) on individuated finger movements in piano playing. Joint motion at the digits was recorded while 5 expert pianists were playing 30 excerpts from musical pieces with different fingering and key locations either at a predetermined normal tempo or as fast as possible. Principal component analysis and cluster analysis using an expectation-maximization algorithm determined three distinct patterns of finger movement coordination for a keypress with each of the index, middle, ring, and little fingers at each of the two tempi. The finger kinematics of each coordination pattern was overall similar across the tempi. Tone sequences assigned into each cluster were also similar for both tempi. A linear regression analysis determined no apparent difference in the amount of movement covariation between the striking and nonstriking fingers at both metacarpo-phalangeal and proximal-interphalangeal joints across the two tempi, which indicated no effect of tempo on independent finger movements in piano playing. In addition, the standard deviation of interkeystroke interval across strokes did not differ between the two tempi, indicating maintenance of rhythmic accuracy of keystrokes. Strong temporal constraints on finger movements during piano playing may underlie the maintained independent control of fingers over a wider range of tempi, a feature being likely to be specific to skilled pianists. PMID:22815403

  2. Investigation on a three-cold-finger pulse tube cryocooler

    NASA Astrophysics Data System (ADS)

    Tang, Qingjun; Chen, Houlei; Cai, Jinghui

    2015-09-01

    This paper introduces a new type of pulse tube cryocooler, three-cold-finger pulse tube cryocooler (TCFPTC), which consists of one linear compressor and three cold fingers, i.e., CFA, CFB and CFC. Those three cold fingers are driven by the linear compressor simultaneously. This paper investigates two aspects. First, it studies the mass flow distribution among the three cold fingers by varying the input electrical power. The cooling powers of the three cold fingers at constant cooling temperatures and the cooling temperatures of the three cold fingers at constant cooling powers with various input electrical powers are investigated. Secondly, the interaction among the three cold fingers is investigated by varying the heating power of any one cold finger. Generally, if the heating power applied on one cold finger increases, with its cold head temperature rising up, the cold head temperatures of the others will decrease. But, when the cooling power of CFC has been 4 W, the cold head temperature of whichever cold finger increases, the cold head temperature of CFA or CFB will seldom change if its heating power keeps constant.

  3. Does finger training increase young children's numerical performance?

    PubMed

    Gracia-Bafalluy, Maria; Noël, Marie-Pascale

    2008-04-01

    Butterworth (1999) suggested that fingers are important in representing numerosities. Furthermore, scores on a finger gnosis test are a better predictor of numerical performance up to 3 years later than intellectual measures (Marinthe et al., 2001; Noël, 2005). We hypothesised that training in finger differentiation would increase finger gnosis and might also improve numerical performance. Accordingly, 47 first-grade children were selected and divided into 3 groups: children with poor finger gnosis who followed the finger-differentiation training programme (G1), a control-intervention who were trained in story comprehension (G2), and a group with high finger gnosis scores who just continued with normal school lessons (G3). The finger training consisted of 2 weekly sessions of half an hour each, for 8 weeks. Before the training period, children in G3 performed better in finger gnosis and enumeration than children in the two other groups. After the training period this pattern remained for the children in G2 and G3, but the children in G1 were significantly better than those in G2 at finger gnosis, representation of numerosities with fingers, and quantification tasks; they also tended to be better at the processing of Arabic digits. These results indicate that improving finger gnosis in young children is possible and that it can provide a useful support to learning mathematics. Such an approach could be particularly appropriate for children with a developmental Gerstmann syndrome. Theoretically, these results are important because they suggest a functional link between finger gnosis and number skills. PMID:18387567

  4. Finger synergies during multi-finger cyclic production of moment of force

    PubMed Central

    Zhang, Wei; Zatsiorsky, Vladimir M.

    2010-01-01

    We investigated multi-finger synergies stabilizing the total moment of force and the total force when the subjects produced a quick cyclic change in the total moment of force. The seated subjects performed the task with the fingers of the dominant arm while paced by the metronome at 1.33 Hz. They were required to produce a rhythmic, sine-like change in the total pronation–supination moment of force computed with respect to the midpoint between the middle and ring fingers. The framework of the uncontrolled manifold hypothesis was used to compute indices of stabilization of the total moment and of the total force across 20 cycles. Variance of the total moment showed a cyclic pattern with peaks close to the peak rate of the moment change. Variance of the total force was maximal close to peak moment into supination. Higher magnitudes of the moment directed against the required moment direction (antagonist moment) were produced by individual fingers during supination efforts as compared to pronation efforts. Indices of multi-finger synergies showed across-trials stabilization of the total moment over the whole cycle but not of the total force. These indices were smaller during supination efforts. We conclude that the central nervous system facilitates multi-finger synergies stabilizing the total rotational action across a variety of tasks. Synergies stabilizing the total force are not seen in tasks that do not explicitly require accurate force control. Pronation efforts are performed more efficiently and with better stabilization of the action. PMID:16944107

  5. Low-energy reactive ion scattering as a probe of surface femtochemical reaction: H+ and H- formation on ionic compound surfaces

    NASA Astrophysics Data System (ADS)

    Souda, R.; Suzuki, T.; Kawanowa, H.; Asari, E.

    1999-01-01

    Capture and loss of valence electrons during low-energy (50-500 eV) proton scattering from some alkali-halide surfaces such as LiCl, NaCl, and KF have been investigated in comparison with those from the TiO2(110) and Cs-adsorbed Si(100) surfaces. The primary H+ ion survives neutralization when scattered from the highly ionized target species existing on the surface. For H- ion formation, a close atomic encounter with individual target ions is found to be important; the H- ion is formed more efficiently on the cationic site than on the anionic site despite the fact that the valence electron is spacially localized on the latter. This is because the charge state of scattered hydrogen is determined during a transient chemisorption state and amphoteric hydrogen tends to be coordinated negatively (positively) on the cationic site (the anionic site). The final charge state of scattered hydrogen is fixed at a certain bond-breaking distance (˜5.0 a.u.) from the surface where the well-defined atomic orbital of hydrogen evolves. The competing nonlocal resonance tunneling is suppressed at the ionic-compound surfaces due to the existence of a large band gap, so that hydrogen is scattered without losing the memory of such a transient chemisorption state.

  6. The Role of Vision in the Development of Finger-Number Interactions: Finger-Counting and Finger-Montring in Blind Children

    ERIC Educational Resources Information Center

    Crollen, Virginie; Mahe, Rachel; Collignon, Olivier; Seron, Xavier

    2011-01-01

    Previous research has suggested that the use of the fingers may play a functional role in the development of a mature counting system. However, the role of developmental vision in the elaboration of a finger numeral representation remains unexplored. In the current study, 14 congenitally blind children and 14 matched sighted controls undertook…

  7. X-231A demonstration of in-situ remediation of DNAPL compounds in low permeability media by soil fracturing with thermally enhanced mass recovery or reactive barrier destruction

    SciTech Connect

    Siegrist, R.L. |; Lowe, K.S.; Murdoch, L.D. |; Slack, W.W.; Houk, T.C.

    1998-03-01

    The overall goal of the program of activities is to demonstrate robust and cost-effective technologies for in situ remediation of DNAPL compounds in low permeability media (LPM), including adaptations and enhancements of conventional technologies to achieve improved performance for DNAPLs in LPM. The technologies sought should be potential for application at simple, small sites (e.g., gasoline underground storage tanks) as well as at complex, larger sites (e.g., DOE land treatment units). The technologies involved in the X-231A demonstration at Portsmouth Gaseous Diffusion Plant (PORTS) utilized subsurface manipulation of the LPM through soil fracturing with thermally enhanced mass recovery or horizontal barrier in place destruction. To enable field evaluation of these approaches, a set of four test cells was established at the X-231A land treatment unit at the DOE PORTS plant in August 1996 and a series of demonstration field activities occurred through December 1997. The principal objectives of the PORTS X-231A demonstration were to: determine and compare the operational features of hydraulic fractures as an enabling technology for steam and hot air enhanced soil vapor extraction and mass recovery, in situ interception and reductive destruction by zero valent iron, and in situ interception and oxidative destruction by potassium permanganate; determine the interaction of the delivered agents with the LPM matrix adjacent to the fracture and within the fractured zone and assess the beneficial modifications to the transport and/or reaction properties of the LPM deposit; and determine the remediation efficiency achieved by each of the technology strategies.

  8. Reactivity of C,N-chelated organoboron compounds with lithium anilides--formation of unexpected 1,2,3-trisubstituted 1H-2,1-benzazaboroles.

    PubMed

    Hejda, Martin; Lyčka, Antonín; Jambor, Roman; Růžička, Aleš; Dostál, Libor

    2013-05-14

    A set of C,N-intramolecularly coordinated boranes containing various C,N-chelating ligands L(1-3) (where L(1) = [o-(CH=NtBu)C6H4], L(2) = [o-(CH=N-2,6-iPr2C6H3)C6H4], L(3) = [o-(CH2NMe2)C6H4]); L(1-3)BCl2 (for 1 L = L(1), for 2 L = L(2), for 5 L = L(3)), L(1)BPhCl (3) and L(1)BCy2 (4) (where Cy = cyclohexyl) were synthesized and fully characterized by multinuclear NMR spectroscopy and in cases of 1 and 3-5 by the single crystal X-ray diffraction analysis. The reaction of with the anilides ArNHLi (Ar = 2,6-Me2C6H3 or 2,6-iPr2C6H3) proceeded via unexpected addition of anilide across the C=N bond yielding 1,2,3-trisubstituted 1H-2,1-benzazaboroles 6-11, whose structures were unambiguously established by single crystal X-ray diffraction analysis (except for 11) and multinuclear NMR spectroscopy. In contrast, compounds 4 and 5 were inert towards ArNHLi. The investigation dealing with the reaction mechanism between the parent boranes 1-3 and ArNHLi revealed that amidolithiation of the C=N double bond involved in the ligand backbones is the crucial step of the whole reaction. The C=N double bond in 1-3 is activated by its coordination to the ortho bonded Lewis acidic boron center, which was also proven by the fact that the non-substituted ligand L(1)H did not react with ArNHLi under the same reaction conditions in an analogous reaction. PMID:23361168

  9. Reactive arthritis

    MedlinePlus

    Reactive arthritis is a group of conditions that may involve the joints, eyes, and urinary and genital systems. ... The exact cause of reactive arthritis is unknown. It occurs most often in men younger than age 40. It may follow an infection in the urethra ...

  10. Torque Control of Underactuated Tendon-driven Robotic Fingers

    NASA Technical Reports Server (NTRS)

    Abdallah, Muhammad E. (Inventor); Ihrke, Chris A. (Inventor); Reiland, Matthew J. (Inventor); Wampler, Charles W. (Inventor); Diftler, Myron A. (Inventor); Platt, Robert (Inventor); Bridgwater, Lyndon (Inventor)

    2013-01-01

    A robotic system includes a robot having a total number of degrees of freedom (DOF) equal to at least n, an underactuated tendon-driven finger driven by n tendons and n DOF, the finger having at least two joints, being characterized by an asymmetrical joint radius in one embodiment. A controller is in communication with the robot, and controls actuation of the tendon-driven finger using force control. Operating the finger with force control on the tendons, rather than position control, eliminates the unconstrained slack-space that would have otherwise existed. The controller may utilize the asymmetrical joint radii to independently command joint torques. A method of controlling the finger includes commanding either independent or parameterized joint torques to the controller to actuate the fingers via force control on the tendons.

  11. Visualization and Quantification of Fingering Flow Using Light Transmission Method

    NASA Astrophysics Data System (ADS)

    Rezanezhad, F.; Roth, K.

    2007-12-01

    With the aim of studying the physical process concerning the unstable fingering phenomena in two dimensions, experiments of vertical infiltration through layered sand were carried out in the laboratory using Hele-Shaw cells. We developed a light transmission method to measure the dynamics of water saturation within flow fingers in great detail with high spatial and temporal resolution. The method was calibrated using X-ray absorption. We improved the measured light transmission with correction for scattering effects through deconvolution with a point spread function which allows us to obtain quantitative high spatial resolution measurements. After fingers had fully developed, we added a dye tracer in order to distinguish mobile and immobile water fractions. Fully developed fingers consist of a tip, a core with mobile water, and a hull with immobile water. We analyzed the dynamics of water saturation within the finger tip, along the finger core behind the tip, and within the fringe of the fingers during radial growth. Our results confirm previous findings of saturation overshoot in the finger tips and revealed a saturation minimum behind the tip as a new feature. The finger development was characterized by a gradual increase in water content within the core of the finger behind this minimum and a gradual widening of the fingers to a quasi-stable state which evolves at time scales that are orders of magnitude longer than those of fingers' evolution. In this state, a sharp separation into a core with fast convective flow and a fringe with exceedingly slow flow was detected. All observed phenomena, with the exception of saturation overshoot, could be consistently explained based on the hysteretic behavior of the soil-water characteristic.

  12. Experimental study of fingered flow through initially dry sand

    NASA Astrophysics Data System (ADS)

    Rezanezhad, F.; Vogel, H.-J.; Roth, K.

    2006-08-01

    Water infiltration into coarse textured dry porous media becomes instable depending on flow conditions characterized through dimensionless quantities, i.e. the Bond number and the Capillary number. Instable infiltration fronts break into flow fingers which we investigate experimentally using Hele-Shaw cells. We further developed a light transmission method to measure the dynamics of water within flow fingers in great detail with high spatial and temporal resolution. The method was calibrated using x-ray absorption and the measured light transmission was corrected for scattering effects through deconvolution with a point spread function. Additionally we applied a dye tracer to visualize the velocity field within flow fingers. We analyzed the dynamics of water within the finger tips, along the finger core behind the tip, and within the fringe of the fingers during radial growth. Our results confirm previous findings of saturation overshoot in the finger tips and revealed a saturation minimum behind the tip as a new feature. The finger development was characterized by a gradual increase in water content within the core of the finger behind this minimum and a gradual widening of the fingers to a quasi-stable state which evolves on time scales that are orders of magnitudes longer than those of fingers' evolution. In this state, a sharp separation into a core with fast convective flow and a fringe with exceedingly slow flow was detected. All observed phenomena could by consistently explained based on the hysteretic behavior of the soil- water characteristic and on the positive pressure induced at the finger tip by the high flow velocity.

  13. Fingering instabilities in Newtonian and non-Newtonian fluids

    NASA Astrophysics Data System (ADS)

    Kennedy, Kristi E.

    Fingering has been studied in different fluid systems. Viscous fingering, which is driven by a difference in viscosity between fluids, has been studied by both experiments and numerical simulations. We used a single fluid with a temperature-dependent viscosity and studied the instability for a range of inlet pressures and viscosity ratios. The spreading and fingering of a fluid drop subjected to a centrifugal force, known as spin coating, has also been studied for a range of drop volumes and rotation speeds, both for a Newtonian and a non-Newtonian fluid. Experiments on viscous fingering with a single fluid, glycerine, show that an instability occurs at the boundary separating hot and cold fluid. The results indicate that the instability is similar to that which occurs between two miscible fluids. Fingering only occurs for high enough values of the inlet pressure and viscosity ratio. The wavelength of the fingering pattern is found to be proportional to the cell width for the two smallest cell widths used. The fingering patterns seen in the simulations are very similar to the experimental patterns, although there are some quantitative differences. In particular, the wavelength of the instability is seen to depend only weakly on the cell width. The spreading of silicone oil, a Newtonian fluid, during spin coating follows the time dependence predicted theoretically, although with a shift in the scaled time variable. Once the radius of the spreading silicone oil drop becomes large enough, fingers form around the perimeter of the drop for all experimental conditions studied. The number of fingers and the growth rate of the fingers are in agreement with theoretical predictions. Fingers are also observed to form for high enough drop volumes and rotation speeds during the spinning of a non-Newtonian fluid drop, Carbopol, which possesses a yield stress. In this case the fingering is a localized effect, occuring once the stress on the drop exceeds the yield stress, rather

  14. Simultaneous dislocation of both interphalangeal joints in the middle finger.

    PubMed

    Hester, Thomas; Mahmood, Shoib; Morar, Yateen; Singh, Ravi

    2015-01-01

    Simultaneous dorsal dislocation of both interphalangeal joints (IPJs) in one finger is an uncommon injury. This injury usually occurs on the ulnar side of the hand involving ring and little fingers. We report a case of simultaneous dislocation of both IPJs in the middle finger. Closed reduction and splinting with the IPJs in extension provided a good result with full range of motion at the patient's final follow-up. PMID:25979959

  15. Bilateral Volleyball-Related Deformity of the Little Fingers: Mallet Finger and Clinodactyly Mimic

    PubMed Central

    Uslu, Mustafa; Solak, Kazim; Ozsahin, Mustafa; Uzun, Hakan

    2011-01-01

    A 14-year-old male high school volleyball player was seen to evaluate right- and left-hand little-finger distal interphalangeal joint deformity and pain. His symptoms began during his second season of competitive play. The distal interphalangeal (DIP) joints of the little fingers flexed 20-30°, and a 10-15° valgus deformity was seen at the same joints. Pain was relieved with rest but returned immediately after playing volleyball, so plain radiographs were obtained. The flexion and valgus deformity was obvious on plain radiographs and through a clinical examination. Thus, a bilateral little-finger distal phalanx base epiphysis injury was seen. This injury is characterized by a biplanar Salter Harris physeal injury; type 5 on anteroposterior radiographs and type 2 on lateral plain radiographs. The deformity occurred as a result of competitive volleyball play. To our knowledge, this is the first reported case of a bilateral biplanar physial injury of the base of distal phalanges of the little fingers. Flexion and valgus deformities of DIP joints are a result of repeated micro traumas around the physis. Key points As a result of repeated micro traumas to the physial region, flexion and valgus deformities of the distal interphalangeal (DIP) joints should be occurred. Sports injuries to the hand often require treatment in orthopedic departments to avoid permanent deformities. Short- or long-term functional results can be gained by simple splinting procedures and abstention from play. PMID:24149318

  16. Stick-slip instability for viscous fingering in a gel

    NASA Astrophysics Data System (ADS)

    Puff, N.; Debrégeas, G.; di Meglio, J.-M.; Higgins, D.; Bonn, D.; Wagner, C.

    2002-05-01

    The growth dynamics of an air finger injected in a visco-elastic gel (a PVA/borax aqueous solution) is studied in a linear Hele-Shaw cell. Besides the standard Saffman-Taylor instability, we observe—with increasing finger velocities—the existence of two new regimes: (a) a stick-slip regime for which the finger tip velocity oscillates between 2 different values, producing local pinching of the finger at regular intervals; (b) a "tadpole" regime where a fracture-type propagation is observed. A scaling argument is proposed to interpret the dependence of the stick-slip frequency with the measured rheological properties of the gel.

  17. Multiple trigger fingers in a musician: a case report.

    PubMed

    Yavari, Masoud; Hassanpour, Seyed Esmail; Mosavizadeh, Seyed Mehdi

    2010-05-01

    Trigger finger is a common disease which particularly occurs in middle-aged women. We present a rare case of a male musician with six trigger fingers (five in the left hand and one in the right hand). Mostly these fingers had been used for playing the guitar. The patient had previously been treated with local steroid injections in his fingers, however no response was seen. Therefore, we performed a surgical procedure. Four weeks after surgery, the patient could play the guitar without discomfort in his hands. PMID:20433233

  18. Vibration white finger and digital systolic pressure during cooling.

    PubMed Central

    Ekenvall, L; Lindblad, L E

    1986-01-01

    A cold provocation test (measurement of finger systolic pressure during combined body and local finger cooling) was performed on 111 male patients exposed to vibration and with a typical history of cold induced white finger. A new method of calculating the test result is described--namely, digital systolic blood pressure in the cooled test finger as a percentage of the systolic pressure in the arm (DP%). The conventional way of calculating the result, the systolic pressure in the cooled test finger as a percentage of the systolic pressure in the test finger when heated to 30 degrees C, corrected for changes in systemic pressure by the use of a reference finger (FSP%), requires the measurement of the systolic pressure in a reference finger. The two ways of calculating the test results give a similar sensitivity (74% for FSP%, 79% for DP% if all histories are regarded as true) but the new method does not require pressure measurements in a reference finger. This makes the test easier to perform and the result easier to understand. PMID:3964577

  19. Numerical Simulations and an Experimental Investigation of a Finger Seal

    NASA Technical Reports Server (NTRS)

    Braun, Minel; Pierson, Hazel; Li, H.; Dong, Dingeng

    2006-01-01

    Besides sealing, the other main goal of a successful finger seal design is to exhibit appropriate compliance to outside forces. The ability of the seal to ride or float along the rotor without rubbing or excessive heating is essential to the successful operation of the seal. The compliance of the finger must only occur in the radial plane; The seal needs to be as sturdy as possible in the axial direction. The compliant finger that moves radially outward with rotor growth and motion has to be able to ride the rotor back down as the rotor diameter recovers or the rotor moves "away". Thus there is an optimum stiffness for the finger.

  20. Extrinsic versus intrinsic hand muscle dominance in finger flexion.

    PubMed

    Al-Sukaini, A; Singh, H P; Dias, J J

    2016-05-01

    This study aims to identify the patterns of dominance of extrinsic or intrinsic muscles in finger flexion during initiation of finger curl and mid-finger flexion. We recorded 82 hands of healthy individuals (18-74 years) while flexing their fingers and tracked the finger joint angles of the little finger using video motion tracking. A total of 57 hands (69.5%) were classified as extrinsic dominant, where the finger flexion was initiated and maintained at proximal interphalangeal and distal interphalangeal joints. A total of 25 (30.5%) were classified as intrinsic dominant, where the finger flexion was initiated and maintained at the metacarpophalangeal joint. The distribution of age, sex, dominance, handedness and body mass index was similar in the two groups. This knowledge may allow clinicians to develop more efficient rehabilitation regimes, since intrinsic dominant individuals would not initiate extrinsic muscle contraction till later in finger flexion, and might therefore be allowed limited early active motion. For extrinsic dominant individuals, by contrast, initial contraction of extrinsic muscles would place increased stress on the tendon repair site if early motion were permitted. PMID:26744509

  1. Impact of artificial "gummy" fingers on fingerprint systems

    NASA Astrophysics Data System (ADS)

    Matsumoto, Tsutomu; Matsumoto, Hiroyuki; Yamada, Koji; Hoshino, Satoshi

    2002-04-01

    Potential threats caused by something like real fingers, which are called fake or artificial fingers, should be crucial for authentication based on fingerprint systems. Security evaluation against attacks using such artificial fingers has been rarely disclosed. Only in patent literature, measures, such as live and well detection, against fake fingers have been proposed. However, the providers of fingerprint systems usually do not mention whether or not these measures are actually implemented in emerging fingerprint systems for PCs or smart cards or portable terminals, which are expected to enhance the grade of personal authentication necessary for digital transactions. As researchers who are pursuing secure systems, we would like to discuss attacks using artificial fingers and conduct experimental research to clarify the reality. This paper reports that gummy fingers, namely artificial fingers that are easily made of cheap and readily available gelatin, were accepted by extremely high rates by 11 particular fingerprint devices with optical or capacitive sensors. We have used the molds, which we made by pressing our live fingers against them or by processing fingerprint images from prints on glass surfaces, etc. We describe how to make the molds, and then show that the gummy fingers, which are made with these molds, can fool the fingerprint devices.

  2. The design and development of a finger joint simulator.

    PubMed

    Joyce, Thomas J

    2016-05-01

    Artificial finger joints lack the long-term clinical success seen with hip and knee prostheses. In part, this can be explained by the challenges of rheumatoid arthritis, a progressive disease which attacks surrounding tissues as well as the joint itself. Therefore, the natural finger joints' biomechanics are adversely affected, and consequently, this imbalance due to subluxing forces further challenges any prosthesis. Many different designs of finger prosthesis have been offered over a period of greater than 50 years. Most of these designs have failed, and it is likely that many of these failures could have been identified had the prostheses been appropriately tested prior to implantation into patients. While finger joint simulators have been designed, arguably only those from a single centre have been able to reproduce clinical-type failures of the finger prostheses tested in them. This article describes the design and development of a finger simulator at Durham University, UK. It explains and justifies the engineering decisions made and thus the evolution of the finger simulator. In vitro results and their linkage to clinical-type failures are outlined to help to show the effectiveness of the simulator. Failures of finger implants in vivo continue to occur, and the need for appropriate in vitro testing of finger prostheses remains strong. PMID:26833697

  3. Finger-Vein Verification Based on Multi-Features Fusion

    PubMed Central

    Qin, Huafeng; Qin, Lan; Xue, Lian; He, Xiping; Yu, Chengbo; Liang, Xinyuan

    2013-01-01

    This paper presents a new scheme to improve the performance of finger-vein identification systems. Firstly, a vein pattern extraction method to extract the finger-vein shape and orientation features is proposed. Secondly, to accommodate the potential local and global variations at the same time, a region-based matching scheme is investigated by employing the Scale Invariant Feature Transform (SIFT) matching method. Finally, the finger-vein shape, orientation and SIFT features are combined to further enhance the performance. The experimental results on databases of 426 and 170 fingers demonstrate the consistent superiority of the proposed approach. PMID:24196433

  4. Teleoperation of Robonaut Using Finger Tracking

    NASA Technical Reports Server (NTRS)

    Champoux, Rachel G.; Luo, Victor

    2012-01-01

    With the advent of new finger tracking systems, the idea of a more expressive and intuitive user interface is being explored and implemented. One practical application for this new kind of interface is that of teleoperating a robot. For humanoid robots, a finger tracking interface is required due to the level of complexity in a human-like hand, where a joystick isn't accurate. Moreover, for some tasks, using one's own hands allows the user to communicate their intentions more effectively than other input. The purpose of this project was to develop a natural user interface for someone to teleoperate a robot that is elsewhere. Specifically, this was designed to control Robonaut on the international space station to do tasks too dangerous and/or too trivial for human astronauts. This interface was developed by integrating and modifying 3Gear's software, which includes a library of gestures and the ability to track hands. The end result is an interface in which the user can manipulate objects in real time in the user interface. then, the information is relayed to a simulator, the stand in for Robonaut, at a slight delay.

  5. Rehabilitation for bilateral amputation of fingers

    USGS Publications Warehouse

    Stapanian, Martin A.; Stapanian, Adrienne M.P.; Staley, Keith E.

    2010-01-01

    We describe reconstructive surgeries, therapy, prostheses, and adaptations for a patient who experienced bilateral amputation of all five fingers of both hands through the proximal phalanges in January 1992. The patient made considerable progress in the use of his hands in the 10 mo after amputation, including nearly a 120% increase in the active range of flexion of metacarpophalangeal joints. In late 1992 and early 1993, the patient had "on-top plasty" surgeries, in which the index finger remnants were transferred onto the thumb stumps, performed on both hands. The increased web space and functional pinch resulting from these procedures made many tasks much easier. The patient and occupational therapists set challenging goals at all times. Moreover, the patient was actively involved in the design and fabrication of all prostheses and adaptations or he developed them himself. Although he was discharged from occupational therapy in 1997, the patient continues to actively find new solutions for prehension and grip strength 18 yr after amputation.

  6. Lipid Gymnastics: Tethers and Fingers in membrane

    NASA Astrophysics Data System (ADS)

    Tayebi, Lobat; Miller, Gregory; Parikh, Atul

    2009-03-01

    A significant body of evidence now links local mesoscopic structure (e.g., shape and composition) of the cell membrane with its function; the mechanisms by which cellular membranes adopt the specific shapes remain poorly understood. Among all the different structures adopted by cellular membranes, the tubular shape is one of the most surprising one. While their formation is typically attributed to the reorganization of membrane cytoskeleton, many exceptions exist. We report the instantaneous formation of tubular membrane mesophases following the hydration under specific thermal conditions. The shapes emerge in a bimodal way where we have two distinct diameter ranges for tubes, ˜20μm and ˜1μm, namely fat fingers and narrow tethers. We study the roughening of hydrated drops of 3 lipids in 3 different spontaneous curvatures at various temp. and ionic strength to figure out the dominant effect in selection of tethers and fingers. Dynamics of the tubes are of particular interest where we observe four distinct steps of birth, coiling, uncoiling and retraction with different lifetime on different thermal condition. These dynamics appear to reflect interplay between membrane elasticity, surface adhesion, and thermal or hydrodynamic gradient.

  7. Reactive Arthritis

    MedlinePlus

    ... with treatment and may cause joint damage. What Research Is Being Conducted on Reactive Arthritis? Researchers continue ... such as methotrexate and sulfasalazine. More information on research is available from the following websites: National Institutes ...

  8. [Primary Study on Noninvasive Detection of Vascular Function Based on Finger Temperature Change].

    PubMed

    Dong, Qing; Li, Xia; Wan, Yungao; Lu, Gaoquan; Wang, Xinxin; Zhang, Kuan

    2016-02-01

    By studying the relationship between fingertip temperature changes and arterial function during vascular reactivity test, we established a new non-invasive method for detecting vascular function, in order to provide an assistance for early diagnosis and prevention of cardiovascular diseases. We customized three modules respectively for blood occlusion, measurement of finger temperature and blood oxygen acquisition, and then we established the hardware of data acquisition system. And the software was programmed with Labview. Healthy subjects [group A, n = 24, (44.6 ± 9.0) years] and subjects with cardiovascular diseases [group B, n = 33, (57.2 ± 9.9) years)] were chosen for the study. Subject's finger temperature, blood oxygen and occlusion pressure of block side during and after unilateral arm brachial artery occlusion were recorded, as well as some other regular physiological indexes. By time-domain analysis, we extracted 12 parameters from fingertip temperature signal, including the initial temperature (Ti), temperature rebound (TR), the time of the temperature recovering to initial status (RIt) and other parameters from the finger temperature signal. We in the experiment also measured other regular physiological body mass index (BMI), systolic blood pressure (SBP), diastiolic blood pressure (DBP) and so on. Results showed that 8 parameters difference between the two group of data were significant. based on the statistical results. A discriminant function of vascular function status was established afterwards. We found in the study that the changes of finger temperature during unilateral arms brachial artery occlusion and open were closely related to vascular function. We hope that the method presented in this article could lay a foundation of early detection of vascular function. PMID:27382755

  9. 21 CFR 888.3230 - Finger joint polymer constrained prosthesis.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Finger joint polymer constrained prosthesis. 888.3230 Section 888.3230 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3230 Finger joint polymer constrained prosthesis. (a) Identification....

  10. Handedness and index finger movements performed on a small touchscreen.

    PubMed

    Aoki, Tomoko; Rivlis, Gil; Schieber, Marc H

    2016-02-01

    Many studies of right/left differences in motor performance related to handedness have employed tasks that use arm movements or combined arm and hand movements rather than movements of the fingers per se, the well-known exception being rhythmic finger tapping. We therefore explored four simple tasks performed on a small touchscreen with relatively isolated movements of the index finger. Each task revealed a different right/left performance asymmetry. In a step-tracking Target Task, left-handed subjects showed greater accuracy with the index finger of the dominant left hand than with the nondominant right hand. In a Center-Out Task, right-handed subjects produced trajectories with the nondominant left hand that had greater curvature than those produced with the dominant right hand. In a continuous Circle Tracking Task, slips of the nondominant left index finger showed higher jerk than slips of the dominant right index finger. And in a continuous Complex Tracking Task, the nondominant left index finger showed shorter time lags in tracking the relatively unpredictable target than the dominant right index finger. Our findings are broadly consistent with previous studies indicating left hemisphere specialization for dynamic control and predictable situations vs. right hemisphere specialization for impedance control and unpredictable situations, the specialized contributions of the two hemispheres being combined to different degrees in the right vs. left hands of right-handed vs. left-handed individuals. PMID:26683065

  11. Toward a Phonetic Representation of Hand Configuration: The Fingers

    ERIC Educational Resources Information Center

    Johnson, Robert E.; Liddell, Scott K.

    2011-01-01

    In this article we describe a componential, articulatory approach to the phonetic description of the configuration of the four fingers. Abandoning the traditional holistic, perceptual approach, we propose a system of notational devices and distinctive features for the description of the four fingers proper (index, middle, ring, and pinky).…

  12. Rediscovering Ruth Faison Shaw and Her Finger-Painting Method

    ERIC Educational Resources Information Center

    Mayer, Veronica

    2005-01-01

    Ruth Faison Shaw was an art educator who developed a nontraditional educational perspective of teaching and a different vision about children's art. As such, she is considered by some to be the initiator of finger-painting in America (The History of Art Education Timeline 1930-1939, 2002.) Shaw developed the technique of finger-painting and a…

  13. Robust Finger Vein ROI Localization Based on Flexible Segmentation

    PubMed Central

    Lu, Yu; Xie, Shan Juan; Yoon, Sook; Yang, Jucheng; Park, Dong Sun

    2013-01-01

    Finger veins have been proved to be an effective biometric for personal identification in the recent years. However, finger vein images are easily affected by influences such as image translation, orientation, scale, scattering, finger structure, complicated background, uneven illumination, and collection posture. All these factors may contribute to inaccurate region of interest (ROI) definition, and so degrade the performance of finger vein identification system. To improve this problem, in this paper, we propose a finger vein ROI localization method that has high effectiveness and robustness against the above factors. The proposed method consists of a set of steps to localize ROIs accurately, namely segmentation, orientation correction, and ROI detection. Accurate finger region segmentation and correct calculated orientation can support each other to produce higher accuracy in localizing ROIs. Extensive experiments have been performed on the finger vein image database, MMCBNU_6000, to verify the robustness of the proposed method. The proposed method shows the segmentation accuracy of 100%. Furthermore, the average processing time of the proposed method is 22 ms for an acquired image, which satisfies the criterion of a real-time finger vein identification system. PMID:24284769

  14. Population Structure and Diversity in Finger Millet (Eleusine coracana) Germplasm.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A genotypic analysis of 79 finger millet accessions (E. coracana subsp. coracana) from 11 African and 5 Asian countries, plus 14 wild E. coracana subsp. africana lines collected in Uganda and Kenya was conducted with 45 SSR markers distributed across the finger millet genome. Phylogenetic and popula...

  15. Finger vein extraction using gradient normalization and principal curvature

    NASA Astrophysics Data System (ADS)

    Choi, Joon Hwan; Song, Wonseok; Kim, Taejeong; Lee, Seung-Rae; Kim, Hee Chan

    2009-02-01

    Finger vein authentication is a personal identification technology using finger vein images acquired by infrared imaging. It is one of the newest technologies in biometrics. Its main advantage over other biometrics is the low risk of forgery or theft, due to the fact that finger veins are not normally visible to others. Extracting finger vein patterns from infrared images is the most difficult part in finger vein authentication. Uneven illumination, varying tissues and bones, and changes in the physical conditions and the blood flow make the thickness and brightness of the same vein different in each acquisition. Accordingly, extracting finger veins at their accurate positions regardless of their thickness and brightness is necessary for accurate personal identification. For this purpose, we propose a new finger vein extraction method which is composed of gradient normalization, principal curvature calculation, and binarization. As local brightness variation has little effect on the curvature and as gradient normalization makes the curvature fairly uniform at vein pixels, our method effectively extracts finger vein patterns regardless of the vein thickness or brightness. In our experiment, the proposed method showed notable improvement as compared with the existing methods.

  16. Coordination of bowing and fingering in violin playing.

    PubMed

    Baader, Andreas P; Kazennikov, Oleg; Wiesendanger, Mario

    2005-05-01

    Playing string instruments implies motor skills including asymmetrical interlimb coordination. How special is musical skill as compared to other bimanually coordinated, non-musical skillful performances? We succeeded for the first time to measure quantitatively bimanual coordination in violinists playing repeatedly a simple tone sequence. A motion analysis system was used to record finger and bow trajectories for assessing the temporal structure of finger-press, finger-lift (left hand), and bow stroke reversals (right arm). The main results were: (1) fingering consisted of serial and parallel (anticipatory) mechanisms; (2) synchronization between finger and bow actions varied from -12 ms to 60 ms, but these 'errors' were not perceived. The results suggest that (1) bow-finger synchronization varied by about 50 ms from perfect simultaneity, but without impairing auditory perception; (2) the temporal structure depends on a number of combinatorial mechanisms of bowing and fingering. These basic mechanisms were observed in all players, including all amateurs. The successful biomechanical measures of fingering and bowing open a vast practical field of assessing motor skills. Thus, objective assessment of larger groups of string players with varying musical proficiency, or of professional string players developing movement disorders, may be helpful in music education. PMID:15820650

  17. [The mallet finger in children and adolescents].

    PubMed

    Schmidt, B; Weinberg, A; Friedrich, H

    2008-06-01

    The "mallet finger" in childhood and adolescence differs from the "mallet finger" in adults because of an open or gradually closing epiphysial plate. Thus, our results of conservative and operative treatment were evaluated particularly in consideration of an open growth plate. We analysed retrospectively the data of all patients who suffered a lesion at the extensor tendon insertion between 1996 and 2005 and were treated at our hospital. The coding was done according to age, sex, localisation, typing by Doyle, therapy and functional outcome. The typing by Doyle was extended through dividing type IV A into A1 (=Aitken I) and A2 (=Aitken II). Depending on extension deficits, the results were evaluated as very good (0 degrees ), medium (<15 degrees) and bad (>15 degrees). 76 patients, 45 boys and 31 girls aged 1 to 17 years (average age: 11.3) were studied. In consideration of the modified typing by Doyle, following distribution arose: type I (n=16), type II (n=14), type III (n=0), type IV A1 (n=17), type IV A2 (n=6), type IV B (n=21) and type IV C (n=2). A total of 50 patients was treated conservatively. Out of 26 operatively treated patients, 4 could be classified as type I, 12 as type II, 1 as type IV A1, 2 as type IV A2, 5 as type IV B, and 2 as type IV C. In 81.5 % of all patients no functional extension deficit was seen at the end of treatment; in patients treated conservatively, the percentage rate was 94 %. 6 patients, who were treated primarily operatively, showed poor functional outcome. 2 of these developed a suture track infection, in 2 cases chondral and osseous damage in the joint existed additionally, in one patient there was a comminuted fracture and in one patient a technical operative problem. Even in adolescence, conservative treatment of types I, IV A1 and A2, as well as IV B injuries is promising. A prerequisite is a consequent splint treatment and strict regular lateral X-ray control of the fracture fragment. At the beginning of treatment, we

  18. Generation of albino Xenopus tropicalis using zinc-finger nucleases.

    PubMed

    Nakajima, Keisuke; Nakajima, Taeko; Takase, Minoru; Yaoita, Yoshio

    2012-12-01

    To generate albino lines of Xenopus tropicalis, we injected fertilized eggs with mRNAs encoding zinc-finger nucleases (ZFNs) targeting the tyrosinase coding region. Surprisingly, vitiligo was observed on the skin of F0 frogs that had been injected with ZFN mRNAs, indicating that both tyrosinase genes in the genome were disrupted in all melanocytes within the vitiligo patches. Mutation analysis using genomic DNA from the skin revealed that two mosaic F0 frogs underwent spatially complex tyrosinase gene mutations. The data implies that the ZFN-induced tyrosinase gene ablations occurred randomly over space and time throughout the entire body, possibly until the young tadpole stage, and that melanocyte precursors lacking functional tyrosinase proliferated and formed vitiligo patches. Several albino X. tropicalis, which are compound heterozygotes for biallelic tyrosinase mutations, were obtained by mating the mosaic F0 frogs. To our knowledge, this is the first report of the albino vertebrates generated by the targeted gene knockout. PMID:23106502

  19. Finger vein image quality evaluation using support vector machines

    NASA Astrophysics Data System (ADS)

    Yang, Lu; Yang, Gongping; Yin, Yilong; Xiao, Rongyang

    2013-02-01

    In an automatic finger-vein recognition system, finger-vein image quality is significant for segmentation, enhancement, and matching processes. In this paper, we propose a finger-vein image quality evaluation method using support vector machines (SVMs). We extract three features including the gradient, image contrast, and information capacity from the input image. An SVM model is built on the training images with annotated quality labels (i.e., high/low) and then applied to unseen images for quality evaluation. To resolve the class-imbalance problem in the training data, we perform oversampling for the minority class with random-synthetic minority oversampling technique. Cross-validation is also employed to verify the reliability and stability of the learned model. Our experimental results show the effectiveness of our method in evaluating the quality of finger-vein images, and by discarding low-quality images detected by our method, the overall finger-vein recognition performance is considerably improved.

  20. A new algorithmic approach for fingers detection and identification

    NASA Astrophysics Data System (ADS)

    Mubashar Khan, Arslan; Umar, Waqas; Choudhary, Taimoor; Hussain, Fawad; Haroon Yousaf, Muhammad

    2013-03-01

    Gesture recognition is concerned with the goal of interpreting human gestures through mathematical algorithms. Gestures can originate from any bodily motion or state but commonly originate from the face or hand. Hand gesture detection in a real time environment, where the time and memory are important issues, is a critical operation. Hand gesture recognition largely depends on the accurate detection of the fingers. This paper presents a new algorithmic approach to detect and identify fingers of human hand. The proposed algorithm does not depend upon the prior knowledge of the scene. It detects the active fingers and Metacarpophalangeal (MCP) of the inactive fingers from an already detected hand. Dynamic thresholding technique and connected component labeling scheme are employed for background elimination and hand detection respectively. Algorithm proposed a new approach for finger identification in real time environment keeping the memory and time constraint as low as possible.

  1. Bulk elastic fingering in soft materials

    NASA Astrophysics Data System (ADS)

    Saintyves, Baudouin; Biggins, John; Wei, Zhiyan; Bouchaud, Elisabeth; Mahadevan, L.; Harvard University Team; Ec2M/Espci Collaboration; Cambridge University Collaboration

    2014-11-01

    Systematic experiments have been performed in purely elastic polyacrylamide gels in Hele-Shaw cells. We have shown that a bulk fingering instability arises in the highly deformable confined elastomers. A systematic study shows that surface tension is not relevant. This instability is sub-critical, with a clear hysteretic behavior. Our experimental observations have been compared very favorably to theoretical and finite element simulations results. In particular, the instability wavelength and the critical front advance have been shown to be proportional to the distance between the two glass plates constituting the cell. A very important feature is that elasticity doesn't influence this lengthscale, making this instability very generic. We will also show some new results about an elastic counterpart experiment of the famous Saffman-Taylor experiment, where we push a soft gel in a stiff one.

  2. Task specificity of finger dexterity tests.

    PubMed

    Berger, Monique A M; Krul, Arno J; Daanen, Hein A M

    2009-01-01

    Finger dexterity tests are generally used to assess performance decrease due to gloves, cold and pathology. It is generally assumed that the O'Connor and Purdue Pegboard test yield similar results. In this experiment we compared these two tests for dry conditions without gloves, and for dry and wet conditions with two types of Nytril gloves. In line with previous observations, wearing gloves caused a decrease in performance of about 12% for the O'Connor test and 9% for the Purdue test. Wetting the gloves prior to the test had no effect on the Purdue score. However, wetting the gloves increased the O'Connor performance significantly by 11%. The results show that the O'Connor and Purdue tests do not yield similar results and should be used selectively for specific tasks. PMID:18339353

  3. Bulk Elastic Fingering in Soft Materials

    NASA Astrophysics Data System (ADS)

    Saintyves, Baudouin; Biggins, John; Wei, Zhiyan; Mora, Serge; Mahadevan, L.; Bouchaud, Elisabeth; Harvard University Team; Espci-Paristech Collaboration; Cambridge University Collaboration; Montpellier 2 University Collaboration

    2015-03-01

    Systematic experiments have been performed in purely elastic polyacrylamide gels in Hele-Shaw cells. We have shown that a bulk fingering instability arises in the highly deformable confined elastomers. A systematic study shows that surface tension is not relevant. This instability is sub-critical, with a clear hysteretic behavior. Our experimental observations have been compared very favorably to theoretical and finite element simulations results. In particular, the instability wavelength and the critical front advance have been shown to be proportional to the distance between the two glass plates constituting the cell. A very important feature is that elasticity doesn't influence this lengthscale, making this instability very generic. We will also show some new results about an elastic counterpart experiment of the famous Saffman-Taylor experiment, where we push a soft gel in a stiff one.

  4. Mechanics of finger-tip electronics

    NASA Astrophysics Data System (ADS)

    Su, Yewang; Li, Rui; Cheng, Huanyu; Ying, Ming; Bonifas, Andrew P.; Hwang, Keh-Chih; Rogers, John A.; Huang, Yonggang

    2013-10-01

    Tactile sensors and electrotactile stimulators can provide important links between humans and virtual environments, through the sensation of touch. Soft materials, such as low modulus silicones, are attractive as platforms and support matrices for arrays sensors and actuators that laminate directly onto the fingertips. Analytic models for the mechanics of three dimensional, form-fitting finger cuffs based on such designs are presented here, along with quantitative validation using the finite element method. The results indicate that the maximum strains in the silicone and the embedded devices are inversely proportional to the square root of radius of curvature of the cuff. These and other findings can be useful in formulating designs for these and related classes of body-worn, three dimensional devices.

  5. Surface Tension and Fingering of Miscible Interfaces

    NASA Technical Reports Server (NTRS)

    Abib, Mohammed; Liu, Jian-Bang; Ronney, Paul D.

    1999-01-01

    Experiments on miscible, buoyantly unstable reaction-diffusion fronts and non-reacting displacement fronts in Hele-Shaw cells show a fingering-type instability whose wavelengths (lambda*) are consistent with an interfacial tension (sigma) at the front caused by the change in chemical composition, even though the solutions are miscible in all proportions. In conjunction with the Saffman-Taylor model, the relation sigma = K/tau, where tau is the interface thickness and K approximately equal 4 +/- 2 x 10(exp -6) dyne, enables prediction of our measured values of lambda* as well as results from prior experiments on miscible interfaces. These results indicate that even for miscible fluids, surface tension is generally a more significant factor than diffusion in interfacial stability and flow characteristics.

  6. Intervarietal variations in various oxidative stress markers and antioxidant potential of finger millet (Eleusine coracana) subjected to drought stress.

    PubMed

    Bartwal, Arti; Pande, Anjali; Sharma, Priyadarshini; Arora, Sandeep

    2016-07-01

    Drought is a major form of abiotic stress leading to lower crop productivity. Experiment was carried out for selecting the most tolerant genotype among six different genotypes of finger millet under drought stress. Seeds of six finger millet genotypes were sown in pots and grown for 35 days. After this period, drought was induced by withholding watering for stressed plants while control plants were watered regularly for comparison. Among all six different varieties of finger millet screened (PR202, PES400, PRM6107, VL283, VL328 and VL149) under varying intensities of drought stress,PRM6107 and PR202 showed highest stress tolerance by limiting excessive accumulation of reactive oxygen species (ROS) through activation of ROS scavenging antioxidative enzymes. A 200% increase in ascorbate content was recorded in PRM6107 and PR202, while in other varieties limited increase in ascorbate content was observed. Maximum decrease in chlorophyll content was observed in VL328 (83%) while least drop was observed in VL149 (65%). Relative water content indicated that PR202 was able to retain maximum water content under stress, as it recorded least drop in relative water content (55%), contributing to its better survival under stress. In conclusion finger millet genotypes PRM6107 and PR202 possessed maximum drought tolerance potential and thus may be used for allele mining of drought tolerant genes, which can further be employed for the development of more drought stress tolerant staple crops using biotechnological approach. PMID:27498495

  7. Metabolite Identification through Machine Learning — Tackling CASMI Challenge Using FingerID

    PubMed Central

    Shen, Huibin; Zamboni, Nicola; Heinonen, Markus; Rousu, Juho

    2013-01-01

    Metabolite identification is a major bottleneck in metabolomics due to the number and diversity of the molecules. To alleviate this bottleneck, computational methods and tools that reliably filter the set of candidates are needed for further analysis by human experts. Recent efforts in assembling large public mass spectral databases such as MassBank have opened the door for developing a new genre of metabolite identification methods that rely on machine learning as the primary vehicle for identification. In this paper we describe the machine learning approach used in FingerID, its application to the CASMI challenges and some results that were not part of our challenge submission. In short, FingerID learns to predict molecular fingerprints from a large collection of MS/MS spectra, and uses the predicted fingerprints to retrieve and rank candidate molecules from a given large molecular database. Furthermore, we introduce a web server for FingerID, which was applied for the first time to the CASMI challenges. The challenge results show that the new machine learning framework produces competitive results on those challenge molecules that were found within the relatively restricted KEGG compound database. Additional experiments on the PubChem database confirm the feasibility of the approach even on a much larger database, although room for improvement still remains. PMID:24958002

  8. Reactive arthritis.

    PubMed

    Keat, A

    1999-01-01

    Reactive arthritis is one of the spondyloarthropathy family of clinical syndromes. The clinical features are those shared by other members of the spondyloarthritis family, though it is distinguished by a clear relationship with a precipitating infection. Susceptibility to reactive arthritis is closely linked with the class 1 HLA allele B27; it is likely that all sub-types pre-dispose to this condition. The link between HLA B27 and infection is mirrored by the development of arthritis in HLA B27-transgenic rats. In this model, arthritis does not develop in animals maintained in a germ-free environment. Infections of the gastrointestinal, genitourinary and respiratory tract appear to provoke reactive arthritis and a wide range of pathogens has now been implicated. Although mechanistic parallels may exist, reactive arthritis is distinguished from Lyme disease, rheumatic fever and Whipple's disease by virtue of the distinct clinical features and the link with HLA B27. As in these conditions both antigens and DNA of several micro-organisms have been detected in joint material from patients with reactive arthritis. The role of such disseminated microbial elements in the provocation or maintenance of arthritis remains unclear. HLA B27-restricted T-cell responses to microbial antigens have been demonstrated and these may be important in disease pathogenesis. The importance of dissemination of bacteria from sites of mucosal infection and their deposition in joints has yet to be fully understood. The role of antibiotic therapy in the treatment of reactive arthritis is being explored; in some circumstances, both the anti-inflammatory and anti-microbial effects of certain antibiotics appear to be valuable. The term reactive arthritis should be seen as a transitory one, reflecting a concept which may itself be on the verge of replacement, as our understanding of the condition develops. Nevertheless it appropriately describes arthritis that is associated with demonstrable

  9. Finger movements and fingers postures in pre-term infants are not a good indicator of brain damage.

    PubMed

    Konishi, Y; Prechtl, H F

    1994-02-01

    The aim of the study was to analyse, with a more detailed classification the occurrence of movements and postures of the fingers in normal and brain damaged pre-term infants. To this end the same videorecordings of normal subjects of the study described by Cioni and Prechtl and those with defined brain lesions from the investigation by Ferrari et al. have been reanalysed. In three general movements, selected randomly from each infant, we assessed the finger movement. There was no systematic trend with age and the repertoire of finger patterns per observation varied between different individuals. Only one or two finger(s) move (pattern B) and synchronized finger opening-closing (pattern D) and the complex and variable movement of three or more fingers (pattern E) are all more often or even only seen during arm movements. Fisting without arm movement (pattern A-) was only seen less frequently in the control cases, in the infants with flares and one-sided lesions. On the other hand, the two latter groups had more often pattern C+ (opening of all fingers with arm movement) while B+ (only one or two fingers move with arm movement) and E+ (three or more fingers move variably with arm movement) was less frequent in the severely damaged infants. Albeit significant differences, the plotted data immediately show the large overlap of the findings between the groups. There was no difference in the fisting between low-risk and neurologically abnormal pre-term infants. These findings corroborate the conclusions that abnormal movements and postures are not useful in the diagnosis of pre-term infants with confirmed brain lesions because of the wide overlap between the values for normal and brain damaged infants. PMID:8200324

  10. Exploration of the Zinc Finger Motif in Controlling Activity of Matrix Metalloproteinases

    PubMed Central

    2015-01-01

    Discovering ways to control the activity of matrix metalloproteinases (MMPs), zinc-dependent enzymes capable of degrading extracellular matrix proteins, is an important field of cancer research. We report here a novel strategy for assembling MMP inhibitors on the basis of oligopeptide ligands by exploring the pattern known as the zinc finger motif. Advanced molecular modeling tools were used to characterize the structural binding motifs of experimentally tested MMP inhibitors, as well as those of newly proposed peptidomimetics, in their zinc-containing active sites. The results of simulations based on the quantum mechanics/molecular mechanics (QM/MM) approach and Car–Parrinello molecular dynamics with QM/MM potentials demonstrate that, upon binding of Regasepin1, a known MMP-9 inhibitor, the Zn2+(His3) structural element is rearranged to the Zn2+(Cys2His2) zinc finger motif, in which two Cys residues are borrowed from the ligand. Following consideration of the crystal structure of MMP-2 with its inhibitor, the oligopeptide APP-IP, we proposed a new peptidomimetic with two replacements in the substrate, Tyr3Cys and Asp6Cys. Simulations show that this peptide variant blocks an enzyme active site by the Zn2+(Cys2His2) zinc finger construct. Similarly, a natural substrate of MMP-2, Ace-Gln-Gly ∼ Ile-Ala-Gly-Nme, can be converted to an inhibiting compound by two replacements, Ile by Cys and Gly by the d isomer of Cys, favoring formation of the zinc finger motif. PMID:25375834

  11. Chemistry of peroxide compounds

    NASA Technical Reports Server (NTRS)

    Volnov, I. I.

    1981-01-01

    The history of Soviet research from 1866 to 1967 on peroxide compounds is reviewed. This research dealt mainly with peroxide kinetics, reactivity and characteristics, peroxide production processes, and more recently with superoxides and ozonides and emphasis on the higher oxides of group 1 and 2 elements. Solid state fluidized bed synthesis and production of high purity products based on the relative solubilities of the initial, intermediate, and final compounds and elements in liquid ammonia are discussed.

  12. Fluctuations in Saffman-Taylor fingers with quenched disorder

    NASA Astrophysics Data System (ADS)

    Torralba, M.; Ortín, J.; Hernández-Machado, A.; Corvera Poiré, E.

    2006-04-01

    We make an experimental characterization of the effect that static disorder has on the shape of a normal Saffman-Taylor finger. We find that static noise induces a small amplitude and long wavelength instability on the sides of the finger. Fluctuations on the finger sides have a dominant wavelength, indicating that the system acts as a selective amplifier of static noise. The dominant wavelength does not seem to be very sensitive to the intensity of static noise present in the system. On the other hand, at a given flow rate, rms fluctuations of the finger width, decrease with decreasing intensity of static noise. This might explain why the sides of the fingers are flat for typical Saffman-Taylor experiments. Comparison with previous numerical studies of the effect that temporal noise has on the Saffman-Taylor finger, leads to conclude that the effect of temporal noise and static noise are similar. The behavior of fluctuations of the finger width found in our experiments, is qualitatively similar to one recently reported, in the sense that, the magnitude of the width fluctuations decays as a power law of the capillary number, at low flow rates, and increases with capillary number for larger flow rates.

  13. Response to reflected-force feedback to fingers in teleoperations

    NASA Technical Reports Server (NTRS)

    Sutter, P. H.; Iatridis, J. C.; Thakor, N. V.

    1989-01-01

    Reflected-force feedback is an important aspect of teleoperations. The objective is to determine the ability of the human operator to respond to that force. Telerobotics operation is simulated by computer control of a motor-driven device with capabilities for programmable force feedback and force measurement. A computer-controlled motor drive is developed that provides forces against the fingers as well as (angular) position control. A load cell moves in a circular arc as it is pushed by a finger and measures reaction forces on the finger. The force exerted by the finger on the load cell and the angular position are digitized and recorded as a function of time by the computer. Flexure forces of the index, long and ring fingers of the human hand in opposition to the motor driven load cell are investigated. Results of the following experiments are presented: (1) Exertion of maximum finger force as a function of angle; (2) Exertion of target finger force against a computer controlled force; and (3) Test of the ability to move to a target force against a force that is a function of position. Averaged over ten individuals, the maximum force that could be exerted by the index or long finger is about 50 Newtons, while that of the ring finger is about 40 Newtons. From the tests of the ability of a subject to exert a target force, it was concluded that reflected-force feedback can be achieved with the direct kinesthetic perception of force without the use of tactile or visual clues.

  14. Dendrites, viscous fingers, and the theory of pattern formation

    NASA Technical Reports Server (NTRS)

    Langer, J. S.

    1989-01-01

    Recent developments in the theory of pattern formation in dendritic crystal growth and viscous fingering in fluids are reviewed. Consideration is given to the discovery that weak capillary forces act as singular perturbations which lead to selection mechanisms in dendritic crystal growth and fingering patterns. Other topics include the conventional thermodynamic model of the solidification of a pure substance from its melt, fingering instability, pattern selection, the solvability theory, dendritic growth rates, the bubble effect discovered by Couder et al. (1986), the dynamics of pattern-forming systems, and snowflake formation.

  15. Narrow fingers in the Saffman-Taylor instability

    NASA Astrophysics Data System (ADS)

    Couder, Y.; Gerard, N.; Rabaud, M.

    1986-12-01

    Saffman-Taylor fingers with a relative width much smaller than the classical limit lambda = 0.5 are found when a small isolated bubble is located at their tip. These solutions are members of a family found by Saffman and Taylor (1958) neglecting superficial tension. Recent theories have shown that when capillary forces are taken into account an unphysical cusplike singularity would appear at the tip of all the fingers with lambda less than 0.5. Conversely, here the replacement of the tip by a small bubble makes these solutions possible. At large velocity these fingers show dendritic instability.

  16. Plasmonic "nano-fingers on nanowires" as SERS substrates.

    PubMed

    Sharma, Yashna; Dhawan, Anuj

    2016-05-01

    A surface-enhanced Raman scattering (SERS) substrate based on plasmonics-active metallic nano-finger arrays grown on arrays of triangular-shaped metal-coated silicon nanowire arrays is proposed. Finite-difference time-domain modeling is employed to numerically calculate the effect of the inter-finger gap and the growth angle of the nano-fingers on the magnitude of SERS enhancement and the plasmon resonance wavelength. Additionally, the polarization dependence of the SERS signals from these novel substrates has been studied. A protocol for the fabrication of the proposed SERS substrate is also discussed. PMID:27128080

  17. Finger rafting: a generic instability of floating elastic sheets.

    PubMed

    Vella, Dominic; Wettlaufer, J S

    2007-02-23

    Colliding ice floes are often observed to form a series of interlocking fingers. We show that this striking phenomenon is not a result of some peculiar property of ice but rather a general and robust mechanical phenomenon reproducible in the laboratory with other floating materials. We determine the theoretical relationship between the width of the resulting fingers and the material's mechanical properties and present experimental results along with field observations to support the theory. The generality of this "finger rafting" suggests that analogous processes may be responsible for creating the large-scale structures observed at the boundaries between Earth's convergent tectonic plates. PMID:17359135

  18. A hierarchical classification method for finger knuckle print recognition

    NASA Astrophysics Data System (ADS)

    Kong, Tao; Yang, Gongping; Yang, Lu

    2014-12-01

    Finger knuckle print has recently been seen as an effective biometric technique. In this paper, we propose a hierarchical classification method for finger knuckle print recognition, which is rooted in traditional score-level fusion methods. In the proposed method, we firstly take Gabor feature as the basic feature for finger knuckle print recognition and then a new decision rule is defined based on the predefined threshold. Finally, the minor feature speeded-up robust feature is conducted for these users, who cannot be recognized by the basic feature. Extensive experiments are performed to evaluate the proposed method, and experimental results show that it can achieve a promising performance.

  19. Examiner's finger-mounted fetal tissue oximetry

    NASA Astrophysics Data System (ADS)

    Kanayama, Naohiro; Niwayama, Masatsugu

    2014-06-01

    The best way to assess fetal condition is to observe the oxygen status of the fetus (as well as to assess the condition of infants, children, and adults). Previously, several fetal oximeters have been developed; however, no instrument has been utilized in clinical practice because of the low-capturing rate of the fetal oxygen saturation. To overcome the problem, we developed a doctor's finger-mounted fetal tissue oximeter, whose sensor volume is one hundredth of the conventional one. Additionally, we prepared transparent gloves. The calculation algorithm of the hemoglobin concentration was derived from the light propagation analysis based on the transport theory. We measured neonatal and fetal oxygen saturation (StO2) with the new tissue oximeter. Neonatal StO was measured at any position of the head regardless of amount of hair. Neonatal StO was found to be around 77%. Fetal StO was detected in every position of the fetal head during labor regardless of the presence of labor pain. Fetal StO without labor pain was around 70% in the first stage of labor and around 60% in the second stage of labor. We concluded that our new concept of fetal tissue oximetry would be useful for detecting fetal StO in any condition of the fetus.

  20. Finger cold-induced vasodilation: a review.

    PubMed

    Daanen, H A M

    2003-06-01

    Cold-induced vasodilation (CIVD) in the finger tips generally occurs 5-10 min after the start of local cold exposure of the extremities. This phenomenon is believed to reduce the risk of local cold injuries. However, CIVD is almost absent during hypothermia, when survival of the organism takes precedence over the survival of peripheral tissue. Subjects that are often exposed to local cold (e.g. fish filleters) develop an enhanced CIVD response. Also, differences between ethnic groups are obvious, with black people having the weakest CIVD response. Many other factors affect CIVD, such as diet, alcohol consumption, altitude, age and stress. CIVD is probably caused by a sudden decrease in the release of neurotransmitters from the sympathetic nerves to the muscular coat of the arterio-venous anastomoses (AVAs) due to local cold. AVAs are specific thermoregulatory organs that regulate blood flow in the cold and heat. Their relatively large diameter enables large amounts of blood to pass and convey heat to the surrounding tissue. Unfortunately, information on the quantity of AVAs is lacking, which makes it difficult to estimate the full impact on peripheral blood flow. This review illustrates the thermospecificity of the AVAs and the close link to CIVD. CIVD is influenced by many parameters, but controlled experiments yield information on how CIVD protects the extremities against cold injuries. PMID:12712346

  1. Finger Length Ratios in Serbian Transsexuals

    PubMed Central

    Vujović, Svetlana; Popović, Srdjan; Mrvošević Marojević, Ljiljana; Ivović, Miomira; Tančić-Gajić, Milina; Stojanović, Miloš; Marina, Ljiljana V.; Barać, Marija; Barać, Branko; Kovačević, Milena; Duišin, Dragana; Barišić, Jasmina; Djordjević, Miroslav L.; Micić, Dragan

    2014-01-01

    Atypical prenatal hormone exposure could be a factor in the development of transsexualism. There is evidence that the 2nd and 4th digit ratio (2D : 4D) associates negatively with prenatal testosterone and positively with estrogens. The aim was to assess the difference in 2D : 4D between female to male transsexuals (FMT) and male to female transsexuals (MFT) and controls. We examined 42 MFT, 38 FMT, and 45 control males and 48 control females. Precise measurements were made by X-rays at the ventral surface of both hands from the basal crease of the digit to the tip using vernier calliper. Control male and female patients had larger 2D : 4D of the right hand when compared to the left hand. Control male's left hand ratio was lower than in control female's left hand. There was no difference in 2D : 4D between MFT and control males. MFT showed similar 2D : 4D of the right hand with control women indicating possible influencing factor in embryogenesis and consequently finger length changes. FMT showed the lowest 2D : 4D of the left hand when compared to the control males and females. Results of our study go in favour of the biological aetiology of transsexualism. PMID:24982993

  2. Ubiquitin interactions of NZF zinc fingers

    PubMed Central

    Alam, Steven L; Sun, Ji; Payne, Marielle; Welch, Brett D; Blake, B Kelly; Davis, Darrell R; Meyer, Hemmo H; Emr, Scott D; Sundquist, Wesley I

    2004-01-01

    Ubiquitin (Ub) functions in many different biological pathways, where it typically interacts with proteins that contain modular Ub recognition domains. One such recognition domain is the Npl4 zinc finger (NZF), a compact zinc-binding module found in many proteins that function in Ub-dependent processes. We now report the solution structure of the NZF domain from Npl4 in complex with Ub. The structure reveals that three key NZF residues (13TF14/M25) surrounding the zinc coordination site bind the hydrophobic ‘Ile44' surface of Ub. Mutations in the 13TF14/M25 motif inhibit Ub binding, and naturally occurring NZF domains that lack the motif do not bind Ub. However, substitution of the 13TF14/M25 motif into the nonbinding NZF domain from RanBP2 creates Ub-binding activity, demonstrating the versatility of the NZF scaffold. Finally, NZF mutations that inhibit Ub binding by the NZF domain of Vps36/ESCRT-II also inhibit sorting of ubiquitylated proteins into the yeast vacuole. Thus, the NZF is a versatile protein recognition domain that is used to bind ubiquitylated proteins during vacuolar protein sorting, and probably many other biological processes. PMID:15029239

  3. From frictional fingers to stick slip bubbles

    NASA Astrophysics Data System (ADS)

    Sandnes, Bjørnar; Jørgen Måløy, Knut; Flekkøy, Eirik; Eriksen, Jon

    2014-05-01

    Gas intrusion into wet porous/deformable/granular media occurs in a wide range of natural and engineered settings. Examples include hydrocarbon recovery, carbon dioxide geo-sequestration, gas venting in sediments and volcanic eruptions. In the case where the intruding gas is able to displace particles and grains, local changes in granular packing fraction govern the evolution of flow paths, resulting in complex pattern formation of the displacement flow. Here we investigate flow patterning as a compressed gas displaces a granular mixture confined in the narrow gap of a Hele-Shaw cell. We find a surprising variety of different pattern formation dynamics, and present a unified phase diagram of the flow morphologies we observe. This talk will focus on one particular transition the system undergoes: from frictional fingers to stick slip bubbles. We show that the frictional fluid flow patterns depend on granular mass loading and system elasticity, analogous to the behaviour of the well-known spring-block sliding friction problem.

  4. Development of Functional Recovery Training Device for Hemiplegic Fingers with Finger-expansion Facilitation Exercise by Stretch Reflex

    NASA Astrophysics Data System (ADS)

    Yu, Yong; Iwashita, Hisashi; Kawahira, Kazumi; Hayashi, Ryota

    This paper develops a functional recovery training device to perform repetition facilitating exercise for hemiplegic finger rehabilitation. On the facilitation exercise, automatic finger expansion can be realized and facilitated by stretch reflex, where a stimulation forces is applied instantaneously on flexion finger for making strech reflex and resistance forces are applied for maintaining the strech reflex. In this paper, novel parallel mechanisms, force sensing system with high sensitivity and resistance accompanying cooperation control method are proposed for sensing, controlling and realizing the stimulation force, resistance forces, strech reflex and repetition facilitating exercise. The effectivities and performances of the device are shown by some experiments.

  5. The generation of zinc finger proteins by modular assembly

    PubMed Central

    Bhakta, Mital; Segal, David J.

    2015-01-01

    The modular assembly (MA) method of generating engineered zinc finger proteins (ZFPs) was the first practical method for creating custom DNA-binding proteins. As such, MA has enabled a vast exploration of sequence-specific methods and reagents, ushering in the modern era of zinc finger-based applications that are described in this volume. The first zinc finger nuclease to cleave an endogenous site was created using MA, as was the first artificial transcription factor to enter phase II clinical trials. In recent years, other excellent methods have been developed that improved the affinity and specificity of the engineered ZFPs. However, MA is still used widely for many applications. This chapter will describe methods and give guidance for the creation of ZFPs using MA. Such ZFPs might be useful as starting materials to perform other methods described in this volume. Here, we also describe a single-strand annealing recombination assay for the initial testing of zinc finger nucleases. PMID:20680825

  6. L'index significant (The Pointed Index Finger).

    ERIC Educational Resources Information Center

    Calbris, G.

    1979-01-01

    In the framework of a study of nonverbal communication, the various meanings attached to the pointed index finger are analyzed. The question is raised as to what extent the findings hold for cultures other than French. (AMH)

  7. Seal finger: A case report and review of the literature

    PubMed Central

    White, Colin P; Jewer, David D

    2009-01-01

    A recent case of seal finger which was misdiagnosed and hence mistreated at the patient’s first presentation is described. The patient was eventually referred to a hand specialist and after the correct treatment with tetracycline, responded well without any long-term sequelae. Seal finger is an occupational injury that occurs to those who work directly or indirectly with seals. The disease entity has been described in both Scandinavian and Canadian literature. The causative microorganism was unknown until 1991, when Mycoplasma phocacerebrale was isolated from both the finger of a patient with seal finger and from the mouth of a seal that bit the patient. Although rare, the disease is not uncommon in marine workers, biologists and veterinarians. Prompt identification based on patient history and treatment with oral tetracycline is pendant to a favourable patient outcome. PMID:21119845

  8. Finger vein recognition based on local directional code.

    PubMed

    Meng, Xianjing; Yang, Gongping; Yin, Yilong; Xiao, Rongyang

    2012-01-01

    Finger vein patterns are considered as one of the most promising biometric authentication methods for its security and convenience. Most of the current available finger vein recognition methods utilize features from a segmented blood vessel network. As an improperly segmented network may degrade the recognition accuracy, binary pattern based methods are proposed, such as Local Binary Pattern (LBP), Local Derivative Pattern (LDP) and Local Line Binary Pattern (LLBP). However, the rich directional information hidden in the finger vein pattern has not been fully exploited by the existing local patterns. Inspired by the Webber Local Descriptor (WLD), this paper represents a new direction based local descriptor called Local Directional Code (LDC) and applies it to finger vein recognition. In LDC, the local gradient orientation information is coded as an octonary decimal number. Experimental results show that the proposed method using LDC achieves better performance than methods using LLBP. PMID:23202194

  9. Finger Vein Recognition Based on Local Directional Code

    PubMed Central

    Meng, Xianjing; Yang, Gongping; Yin, Yilong; Xiao, Rongyang

    2012-01-01

    Finger vein patterns are considered as one of the most promising biometric authentication methods for its security and convenience. Most of the current available finger vein recognition methods utilize features from a segmented blood vessel network. As an improperly segmented network may degrade the recognition accuracy, binary pattern based methods are proposed, such as Local Binary Pattern (LBP), Local Derivative Pattern (LDP) and Local Line Binary Pattern (LLBP). However, the rich directional information hidden in the finger vein pattern has not been fully exploited by the existing local patterns. Inspired by the Webber Local Descriptor (WLD), this paper represents a new direction based local descriptor called Local Directional Code (LDC) and applies it to finger vein recognition. In LDC, the local gradient orientation information is coded as an octonary decimal number. Experimental results show that the proposed method using LDC achieves better performance than methods using LLBP. PMID:23202194

  10. Finger Growth in Surfactant Solution in Hele-Shaw Cells

    NASA Astrophysics Data System (ADS)

    Yamamoto, Takehiro; Yamashita, Atsushi; Nakamura, Yousuke; Hashimoto, Takamasa; Mori, Noriyasu

    2006-05-01

    Viscous fingering in surfactant solutions was experimentally studied. Aqueous solutions of cetyltrimethylammonium bromide (CTAB) with sodium salicylate (NaSal) as a counter ion were used as test fluids. Excess of counter ion was added into a surfactant solution of CTAB to configure network structures of wormlike micelles. The experiments were mainly carried out using a square Hele-Shaw cell. The structure of fingering pattern was dimensionally analyzed to classify the patterns into three types. In addition, growth phenomena distinguishing for the viscous finger in the CTAB/NaSal solutions were observed: surface instabilities with dendrites, and a sudden protrusion from a cuspidate shaped finger tip. The dependence of the sudden protrusion on the shear rate was confirmed by the experiment using a rectangular cell.

  11. Tension Distribution in a Tendon-Driven Robotic Finger

    NASA Technical Reports Server (NTRS)

    Abdallah, Muhammad E. (Inventor); Platt, Robert (Inventor); Wampler, II, Charles W. (Inventor)

    2013-01-01

    A method is provided for distributing tension among tendons of a tendon-driven finger in a robotic system, wherein the finger characterized by n degrees of freedom and n+1 tendons. The method includes determining a maximum functional tension and a minimum functional tension of each tendon of the finger, and then using a controller to distribute tension among the tendons, such that each tendon is assigned a tension value less than the maximum functional tension and greater than or equal to the minimum functional tension. The method satisfies the minimum functional tension while minimizing the internal tension in the robotic system, and satisfies the maximum functional tension without introducing a coupled disturbance to the joint torques. A robotic system includes a robot having at least one tendon-driven finger characterized by n degrees of freedom and n+1 tendons, and a controller having an algorithm for controlling the tendons as set forth above.

  12. Suppression of viscous fingering in nonflat Hele-Shaw cells.

    PubMed

    Brandão, Rodolfo; Fontana, João V; Miranda, José A

    2014-11-01

    Viscous fingering formation in flat Hele-Shaw cells is a classical and widely studied fluid mechanical problem. Recently, instead of focusing on the development of the fingering instability, researchers have devised different strategies aiming to suppress its appearance. In this work, we study a protocol that intends to inhibit the occurrence of fingering instabilities in nonflat (spherical and conical) Hele-Shaw cell geometries. By using a mode-coupling theory to describe interfacial evolution, plus a variational controlling technique, we show that viscous fingering phenomena can be minimized in such a confined, curved environment by properly manipulating a time-dependent injection flow rate Q(t). Explicit expressions for Q(t) are derived for the specific cases of spherical and conical cells. The suitability of the controlling method is verified for linear and weakly nonlinear stages of the flow. PMID:25493877

  13. The effects of vibration-reducing gloves on finger vibration

    PubMed Central

    Welcome, Daniel E.; Dong, Ren G.; Xu, Xueyan S.; Warren, Christopher; McDowell, Thomas W.

    2015-01-01

    Vibration-reducing (VR) gloves have been used to reduce the hand-transmitted vibration exposures from machines and powered hand tools but their effectiveness remains unclear, especially for finger protection. The objectives of this study are to determine whether VR gloves can attenuate the vibration transmitted to the fingers and to enhance the understanding of the mechanisms of how these gloves work. Seven adult male subjects participated in the experiment. The fixed factors evaluated include hand force (four levels), glove condition (gel-filled, air bladder, no gloves), and location of the finger vibration measurement. A 3-D laser vibrometer was used to measure the vibrations on the fingers with and without wearing a glove on a 3-D hand-arm vibration test system. This study finds that the effect of VR gloves on the finger vibration depends on not only the gloves but also their influence on the distribution of the finger contact stiffness and the grip effort. As a result, the gloves increase the vibration in the fingertip area but marginally reduce the vibration in the proximal area at some frequencies below 100 Hz. On average, the gloves reduce the vibration of the entire fingers by less than 3% at frequencies below 80 Hz but increase at frequencies from 80 to 400 Hz. At higher frequencies, the gel-filled glove is more effective at reducing the finger vibration than the air bladder-filled glove. The implications of these findings are discussed. Relevance to industry Prolonged, intensive exposure to hand-transmitted vibration can cause hand-arm vibration syndrome. Vibration-reducing gloves have been used as an alternative approach to reduce the vibration exposure. However, their effectiveness for reducing finger-transmitted vibrations remains unclear. This study enhanced the understanding of the glove effects on finger vibration and provided useful information on the effectiveness of typical VR gloves at reducing the vibration transmitted to the fingers. The new

  14. Fingered bola body, bola with same, and methods of use

    NASA Technical Reports Server (NTRS)

    Dzenitis, John M. (Inventor); Billica, Linda W. (Inventor)

    1994-01-01

    The present invention discloses bola bodies, bolas, and a snaring method which makes use such devices. A bola body, according to the present invention, is nonspherical or irregular in shape rather than a smooth sphere or ovoid body. One or more fingers extends from the bola body. These fingers may be relatively straight or they may have crooked or bent portions to enhance entanglement with a bola line or lines or with each other. Two or more of such fingers may be used and may be regularly or irregularly spaced apart on a bola body. A bola with such bodies includes lines which are connected to the other bodies. In one particular embodiment of a bola body, according to the present invention, the body has an irregular shape with a bottom rectangular portion and a top pyramid portion forming a nose. A plurality of fingers is extended from the pyramidal top portion with one finger extended up and away from each of four corners of the top portion. Such a bola body tends to be initially oriented with its nose and fingers against an object being snared since the body is pulled nose first when a bola line is secured at the tip of the pyramidal portion of the bola body. With such a bola, an unwrapping bola body can slip around a target member so that two of the rod-shaped fingers catch a bola line and guide it into an area or crook between the fingers and a side of the top pyramidal portion of the bola body. Tension on the bola line maintains the line in the crook and tends to press the fingers against the unwrapped target member to stabilize the wrapping of the line about the target member. With such a bola, it is difficult for two or more lines unwrapping in different directions to move past one another without being forced together by line tension. Also, the fingers of such bola bodies may hook and hold each other. The fingers may also hook or entangle some object on or portion of the target member. A probable known target member has known dimensions and shapes so that

  15. Finger blood content, light transmission, and pulse oximetry errors.

    PubMed

    Craft, T M; Lawson, R A; Young, J D

    1992-01-01

    The changes in light emitting diode current necessary to maintain a constant level of light incident upon a photodetector were measured in 20 volunteers at the two wavelengths employed by pulse oximeters. Three states of finger blood content were assessed; exsanguinated, hyperaemic, and normal. The changes in light emitting diode current with changes in finger blood content were small and are not thought to represent a significant source of error in saturation as measured by pulse oximetry. PMID:1536406

  16. Detecting overblown flute fingerings from the residual noise spectrum.

    PubMed

    Verfaille, Vincent; Depalle, Philippe; Wanderley, Marcelo M

    2010-01-01

    Producing a tone by increasing the blowing pressure to excite a higher frequency impedance minimum, or overblowing, is widely used in standard flute technique. In this paper, the effect of overblowing a fingering is explored with spectral analysis, and a fingering detector is designed based on acoustical knowledge and pattern classification techniques. The detector performs signal analysis of the strong broadband signal, that is, spectrally shaped by the pipe impedance, and measures the spectral energy during the attack around multiples of the fundamental frequency sub-multiples over the first octave and a half. It is trained and evaluated on sounds recorded with four expert performers. They played six series of tones from overblown and regular fingerings, with frequencies that are octave- and non-octave-related to the playing frequency. The best of the four proposed sound descriptors allows for a detection error below 1.3% for notes with two and three fingerings (C(5), D(5), C(6), and Cmusical sharp(6)) and below 14% for four (E(6)) or five fingerings (G(6)). The error is shown to dramatically increase when two fingerings' impedance become too similar (E(6) and A(4) and G(6) and C(5)). PMID:20058998

  17. Biomechanical Analysis of Force Distribution in Human Finger Extensor Mechanisms

    PubMed Central

    Hu, Dan; Ren, Lei; Howard, David; Zong, Changfu

    2014-01-01

    The complexities of the function and structure of human fingers have long been recognised. The in vivo forces in the human finger tendon network during different activities are critical information for clinical diagnosis, surgical treatment, prosthetic finger design, and biomimetic hand development. In this study, we propose a novel method for in vivo force estimation for the finger tendon network by combining a three-dimensional motion analysis technique and a novel biomechanical tendon network model. The extensor mechanism of a human index finger is represented by an interconnected tendinous network moving around the phalanx's dorsum. A novel analytical approach based on the “Principle of Minimum Total Potential Energy” is used to calculate the forces and deformations throughout the tendon network of the extensor mechanism when subjected to an external load and with the finger posture defined by measurement data. The predicted deformations and forces in the tendon network are in broad agreement with the results obtained by previous experimental in vitro studies. The proposed methodology provides a promising tool for investigating the biomechanical function of complex interconnected tendon networks in vivo. PMID:25126576

  18. Fluidic Channels Produced by Electro Hydrodynamic Viscous Fingering

    NASA Astrophysics Data System (ADS)

    Behler, Kristopher; Wetzel, Eric

    2010-03-01

    Viscous fingering is a term describing fingerlike extensions of liquid from a column of low viscosity liquid that has been injected into a more viscous liquid. The modification of viscous fingering, known as electro hydrodynamic viscous fingering (EHVF), utilizes large electrical potentials of 10-60 kV. The fingers see a reduction in size and increase in branching behavior due to the potential applied to the system. The resulting finely structured patterns are analogous to biological systems such as blood vessels and the lymphatic system. In this study silicone oils and water were studied in thin channel Hele-Shaw cells. The interfacial tension was optimized by altering the surfactant concentration in the silicone oils. EHVF of liquid filled packed beds consisting of beads and silicone oils showed retardation of the relaxation of the fingers after the voltage was turned off. Decreased relaxation provides a means to solidify patterns into a curable material, such as polydimethylsiloxane (PDMS). After the water is evacuated from the fingers, the cured materials then possess hollow channels that can be refilled and emptied, thus creating an artificial circulatory system.

  19. Integrating optical finger motion tracking with surface touch events.

    PubMed

    MacRitchie, Jennifer; McPherson, Andrew P

    2015-01-01

    This paper presents a method of integrating two contrasting sensor systems for studying human interaction with a mechanical system, using piano performance as the case study. Piano technique requires both precise small-scale motion of fingers on the key surfaces and planned large-scale movement of the hands and arms. Where studies of performance often focus on one of these scales in isolation, this paper investigates the relationship between them. Two sensor systems were installed on an acoustic grand piano: a monocular high-speed camera tracking the position of painted markers on the hands, and capacitive touch sensors attach to the key surfaces which measure the location of finger-key contacts. This paper highlights a method of fusing the data from these systems, including temporal and spatial alignment, segmentation into notes and automatic fingering annotation. Three case studies demonstrate the utility of the multi-sensor data: analysis of finger flexion or extension based on touch and camera marker location, timing analysis of finger-key contact preceding and following key presses, and characterization of individual finger movements in the transitions between successive key presses. Piano performance is the focus of this paper, but the sensor method could equally apply to other fine motor control scenarios, with applications to human-computer interaction. PMID:26082732

  20. Integrating optical finger motion tracking with surface touch events

    PubMed Central

    MacRitchie, Jennifer; McPherson, Andrew P.

    2015-01-01

    This paper presents a method of integrating two contrasting sensor systems for studying human interaction with a mechanical system, using piano performance as the case study. Piano technique requires both precise small-scale motion of fingers on the key surfaces and planned large-scale movement of the hands and arms. Where studies of performance often focus on one of these scales in isolation, this paper investigates the relationship between them. Two sensor systems were installed on an acoustic grand piano: a monocular high-speed camera tracking the position of painted markers on the hands, and capacitive touch sensors attach to the key surfaces which measure the location of finger-key contacts. This paper highlights a method of fusing the data from these systems, including temporal and spatial alignment, segmentation into notes and automatic fingering annotation. Three case studies demonstrate the utility of the multi-sensor data: analysis of finger flexion or extension based on touch and camera marker location, timing analysis of finger-key contact preceding and following key presses, and characterization of individual finger movements in the transitions between successive key presses. Piano performance is the focus of this paper, but the sensor method could equally apply to other fine motor control scenarios, with applications to human-computer interaction. PMID:26082732

  1. Biomechanical analysis of force distribution in human finger extensor mechanisms.

    PubMed

    Hu, Dan; Ren, Lei; Howard, David; Zong, Changfu

    2014-01-01

    The complexities of the function and structure of human fingers have long been recognised. The in vivo forces in the human finger tendon network during different activities are critical information for clinical diagnosis, surgical treatment, prosthetic finger design, and biomimetic hand development. In this study, we propose a novel method for in vivo force estimation for the finger tendon network by combining a three-dimensional motion analysis technique and a novel biomechanical tendon network model. The extensor mechanism of a human index finger is represented by an interconnected tendinous network moving around the phalanx's dorsum. A novel analytical approach based on the "Principle of Minimum Total Potential Energy" is used to calculate the forces and deformations throughout the tendon network of the extensor mechanism when subjected to an external load and with the finger posture defined by measurement data. The predicted deformations and forces in the tendon network are in broad agreement with the results obtained by previous experimental in vitro studies. The proposed methodology provides a promising tool for investigating the biomechanical function of complex interconnected tendon networks in vivo. PMID:25126576

  2. Viscous Fingering Induced Flow Instability in Multidimensional Liquid Chromatography

    SciTech Connect

    Mayfield, Kirsty; Shalliker, R. Andrew; Catchpoole, Heather J.; Sweeney, Alan P.; Wong, Victor; Guiochon, Georges A

    2005-07-01

    Viscous fingering is a flow instability phenomenon that results in the destabilisation of the interface between two fluids of differing viscosities. The destabilised interface results in a complex mixing of the two fluids in a pattern that resembles fingers. The conditions that enhance this type of flow instability can be found in coupled chromatographic separation systems, even when the solvents used in each of the separation stages have seemingly similar chemical and physical properties (other than viscosity). For example, the viscosities of acetonitrile and methanol are sufficiently different that instability at the interface between these two solvents can be established and viscous fingering results. In coupled chromatographic systems, the volume of solvent transported from one separation dimension to the second often exceeds the injection volume by two or more orders of magnitude. As a consequence, viscous fingering may occur, when otherwise following the injection of normal analytical size injection plugs viscous fingering would not occur. The findings in this study illustrate the onset of viscous fingering in emulated coupled chromatographic systems and show the importance of correct solvent selection for optimum separation performance.

  3. Enhancement of finger motion range with compliant anthropomorphic joint design.

    PubMed

    Çulha, Utku; Iida, Fumiya

    2016-04-01

    Robotic researchers have been greatly inspired by the human hand in the search to design and build adaptive robotic hands. Especially, joints have received a lot of attention upon their role in maintaining the passive compliance that gives the fingers flexibility and extendible motion ranges. Passive compliance, which is the tendency to be employed in motion under the influence of an external force, is the result of the stiffness and the geometrical constraints of the joints that define the direction of the motion. Based on its building elements, human finger joints have multi-directional passive compliance which means that they can move in multiple axis of motion under external force. However, due to their complex anatomy, only simplified biomechanical designs based on physiological analysis are preferred in present day robotics. To imitate the human joints, these designs either use fixed degree of freedom mechanisms which substantially limit the motion axes of compliance, or soft materials that can deform in many directions but hinder the fingers' force exertion capacities. In order to find a solution that lies between these two design approaches, we are using anatomically correct finger bones, elastic ligaments and antagonistic tendons to build anthropomorphic joints with multi-directional passive compliance and strong force exertion capabilities. We use interactions between an index finger and a thumb to show that our joints allow the extension of the range of motion of the fingers up to 245% and gripping size to 63% which can be beneficial for mechanical adaptation in gripping larger objects. PMID:26891473

  4. Rapid functional plasticity of the somatosensory cortex after finger amputation.

    PubMed

    Weiss, T; Miltner, W H; Huonker, R; Friedel, R; Schmidt, I; Taub, E

    2000-09-01

    Recent research indicates that areas of the primary somatosensory (SI) and primary motor cortex show massive cortical reorganization after amputation of the upper arm, forearm or fingers. Most of these studies were carried out months or several years after amputation. In the present study, we describe cortical reorganization of areas in the SI of a patient who underwent amputation of the traumatized middle and ring fingers of his right hand 10 days before cortical magnetic source imaging data were obtained. Somatosensory-evoked magnetic fields (SEF) to mechanical stimuli to the finger tips were recorded and single moving dipoles were calculated using a realistic volume conductor model. Results reveal that the dipoles representing the second and fifth fingers of the affected hand were closer together than the comparable dipoles of the unaffected hand. Our findings demonstrate that neural cell assemblies in SI which formerly represented the right middle and ring fingers of this amputee became reorganized and invaded by neighbouring cell assemblies of the index and little finger of the same hand. These results indicate that functional plasticity occurs within a period of 10 days after amputation. PMID:11037286

  5. ATMOSPHERIC FREONS AND HALOGENATED COMPOUNDS

    EPA Science Inventory

    Ambient levels of atmospheric Freons, halogenated hydrocarbons, and SF6 were measured at various locations in the U.S.A. Compounds such as CCl3F, CCl2F2, CH3-CCl3, and CCl4 were ubiquitious and generally measured at sub ppb levels. Tropospherically reactive compounds such as C2Cl...

  6. What Is Reactive Arthritis?

    MedlinePlus

    ... Arthritis PDF Version Size: 69 KB November 2014 What is Reactive Arthritis? Fast Facts: An Easy-to- ... Information About Reactive Arthritis and Other Related Conditions What Causes Reactive Arthritis? Sometimes, reactive arthritis is set ...

  7. Schlieren Imaging of Viscous-Fingering in a Horizontal Hele-Shaw Cell

    NASA Astrophysics Data System (ADS)

    Bunton, Patrick; Brooks, Gabrielle; Stewart, Simone; de Wit, Anne

    2014-11-01

    Viscous fingering (VF) occurs when a fluid of high mobility displaces a fluid of lower mobility. Recent increased interest is motivated by applications to enhanced petroleum recover, pollutant dispersal, and climatological issues along with increased computational capability. Most often VF is observed in a Hele-Shaw (HS) cell consisting of two transparent plates separated by a narrow gap. For the typical case of transparent fluids, dyes are used for observation. Chemical indicators are used for reactive studies. Other techniques have been used such as interferometry, Schlieren, shadowgraph, fluorescence, and MRI. Here is reported a modification of Schlieren for use in imaging horizontal flows in a HS cell. The technique requires no dyes or chemical indicators that might complicate interpretation or even alter the dynamics. It is exquisitely sensitive, readily yielding information about 3D flows in gaps under a mm. Schlieren imaging is particularly useful in that it allows one to image flows within the fingers, rather than merely imaging the boundary. Following a description of the technique, data for water-glycerol systems are presented revealing previously unobserved internal detail. This detail is interpreted in terms of recently published 3D models of VF. Supported by the National Science Foundation CBET 1335739.

  8. Schlieren imaging of viscous fingering in a horizontal Hele-Shaw cell

    NASA Astrophysics Data System (ADS)

    Bunton, P.; Marin, D.; Stewart, S.; Meiburg, E.; De Wit, A.

    2016-02-01

    Interfaces between different fluids can be unstable with regard to hydrodynamic instabilities such as viscous fingering or buoyancy-driven convection. To study such instabilities experimentally for transparent fluids, dyes or chemical indicators are most often used to track the dynamics. While the interfacial deformation can easily be tracked by color changes, it is difficult to have access to the internal flow structure for comparison with theoretical predictions. To overcome this problem, a modification of a Schlieren technique is introduced to image 3D flows during viscously driven instabilities in a horizontal Hele-Shaw cell without using any dye or chemical indicator. The method is exquisitely sensitive, readily yielding information about 3D flows in gaps under a millimeter and allowing imaging of the flow structure internal to the fingers, rather than merely imaging the flow boundary. Following a description of the technique, visualization of dynamics for nonreactive water-glycerol and reactive displacements is presented revealing previously unobserved internal flows. These flows are tentatively interpreted in terms of known theoretical predictions.

  9. Making fingers and words count in a cognitive robot

    PubMed Central

    De La Cruz, Vivian M.; Di Nuovo, Alessandro; Di Nuovo, Santo; Cangelosi, Angelo

    2013-01-01

    Evidence from developmental as well as neuroscientific studies suggest that finger counting activity plays an important role in the acquisition of numerical skills in children. It has been claimed that this skill helps in building motor-based representations of number that continue to influence number processing well into adulthood, facilitating the emergence of number concepts from sensorimotor experience through a bottom-up process. The act of counting also involves the acquisition and use of a verbal number system of which number words are the basic building blocks. Using a Cognitive Developmental Robotics paradigm we present results of a modeling experiment on whether finger counting and the association of number words (or tags) to fingers, could serve to bootstrap the representation of number in a cognitive robot, enabling it to perform basic numerical operations such as addition. The cognitive architecture of the robot is based on artificial neural networks, which enable the robot to learn both sensorimotor skills (finger counting) and linguistic skills (using number words). The results obtained in our experiments show that learning the number words in sequence along with finger configurations helps the fast building of the initial representation of number in the robot. Number knowledge, is instead, not as efficiently developed when number words are learned out of sequence without finger counting. Furthermore, the internal representations of the finger configurations themselves, developed by the robot as a result of the experiments, sustain the execution of basic arithmetic operations, something consistent with evidence coming from developmental research with children. The model and experiments demonstrate the importance of sensorimotor skill learning in robots for the acquisition of abstract knowledge such as numbers. PMID:24550795

  10. The Use of an MEG/fMRI-Compatible Finger Motion Sensor in Detecting Different Finger Actions

    PubMed Central

    Yong, Xinyi; Li, Yasong; Menon, Carlo

    2016-01-01

    This paper explores the use of a novel device in detecting different finger actions among healthy individuals and individuals with stroke. The device is magnetoencephalography (MEG) and functional magnetic resonance imaging (fMRI) compatible. It was prototyped to have four air-filled chambers that are made of silicone elastomer, which contains low magnetizing materials. When an individual compresses the device with his/her fingers, each chamber experiences a change in pressure, which is detected by a pressure sensor. In a previous recent work, our device was shown to be MEG/fMRI compatible. In this study, our research effort focuses on using the device to detect different finger actions (e.g., grasping and pinching) in non-shielded rooms. This is achieved by applying a support vector machine to the sensor data collected from the device when participants are resting and executing the different finger actions. The total number of possible finger actions that can be executed using the device is 31. The healthy participants could perform all the 31 different finger actions and the average classification accuracy achieved is 95.53 ± 2.63%. The stroke participants could perform all the 31 different finger actions with their healthy hand and the average classification accuracy achieved is 83.13 ± 6.69%. Unfortunately, the functions of their affected hands are compromised due to stroke. Thus, the number of finger actions they could perform ranges from 2 to 24, depending on the level of impairments. The average classification accuracy for the affected hand is 83.99 ± 16.38%. The ability to identify different finger actions using the device can provide a mean to researchers to label the data automatically in MEG/fMRI studies. In addition, the sensor data acquired from the device provide sensorimotor-­related information, such as speed and force, when the device is compressed. Thus, brain activations can be correlated with this information during different

  11. Extrinsic Finger and Thumb Muscles Command a Virtual Hand to Allow Individual Finger and Grasp Control

    PubMed Central

    Hargrove, Levi J.; Weir, Richard F. ff.; Kuiken, Todd A.

    2015-01-01

    Fine-wire intramuscular electrodes were used to obtain EMG signals from six extrinsic hand muscles associated with the thumb, index, and middle fingers. Subjects’ EMG activity was used to control a virtual three-DOF hand as they conformed the hand to a sequence of hand postures testing two controllers: direct EMG control and pattern recognition control. Subjects tested two conditions using each controller: starting the hand from a pre-defined neutral posture before each new posture and starting the hand from the previous posture in the sequence. Subjects demonstrated their ability to simultaneously, yet individually, move all three DOFs during the direct EMG control trials, however results showed subjects did not often utilize this feature. Performance metrics such as failure rate and completion time showed no significant difference between the two controllers. PMID:25099395

  12. Magic Ring: A Finger-Worn Device for Multiple Appliances Control Using Static Finger Gestures

    PubMed Central

    Jing, Lei; Zhou, Yinghui; Cheng, Zixue; Huang, Tongjun

    2012-01-01

    An ultimate goal for Ubiquitous Computing is to enable people to interact with the surrounding electrical devices using their habitual body gestures as they communicate with each other. The feasibility of such an idea is demonstrated through a wearable gestural device named Magic Ring (MR), which is an original compact wireless sensing mote in a ring shape that can recognize various finger gestures. A scenario of wireless multiple appliances control is selected as a case study to evaluate the usability of such a gestural interface. Experiments comparing the MR and a Remote Controller (RC) were performed to evaluate the usability. From the results, only with 10 minutes practice, the proposed paradigm of gestural-based control can achieve a performance of completing about six tasks per minute, which is in the same level of the RC-based method. PMID:22778612

  13. A study of white finger in the gas industry.

    PubMed Central

    Walker, D D; Jones, B; Ogston, S; Tasker, E G; Robinson, A J

    1985-01-01

    Men engaged in breaking or reinstating road surfaces are exposed to vibration from mechanical tools. In view of the lack of epidemiological information on vibration white finger in such a population, a survey was carried out to identify the prevalence of symptoms of white finger in a sample of men using these tools in the gas industry and to compare the prevalence with that found in a control group not occupationally exposed to vibration. Altogether 905 men (97%) in the gas industry and 552 men (92%) in the control group were interviewed, using a questionnaire from which the presence or absence of white finger symptoms from all causes was noted. The prevalence of white finger was 9.6% in the group exposed to vibration at work compared with 9.5% in the control group. The prevalence in the former group when adjusted for age differences between the survey and control populations was 12.2%, but this difference did not reach statistical significance. In case the approach of comparing prevalences of white finger from all causes might have obscured any contributory effect of vibration, the prevalence of white finger was examined in relation to the number of years vibrating tools had been used, this being the only measure of exposure to vibration available. No direct association was found between the prevalence of symptoms and number of years vibrating tools had been used. In view of this and the absence of a significant excess of white finger symptoms in the group using vibratory tools, the authors conclude that vibration white finger is not a special problem in the gas industry. Nevertheless, experimental tests carried out on the different types of roadbreakers used in the industry and on different road surfaces indicate that the vibration levels exceed the standards advocated in the draft international standard DIS 5349 (1979) at the lower end of the frequency spectrum. That no particular problem has been found may be due to the relatively short exposures to vibration

  14. High-Speed, High-Temperature Finger Seal Test Evaluated

    NASA Technical Reports Server (NTRS)

    Proctor, Margaret P.

    2003-01-01

    A finger seal, designed and fabricated by Honeywell Engines, Systems and Services, was tested at the NASA Glenn Research Center at surface speeds up to 1200 ft/s, air temperatures up to 1200 F, and pressures across the seal of 75 psid. These are the first test results obtained with NASA s new High-Temperature, High-Speed Turbine Seal Test Rig (see the photograph). The finger seal is an innovative design recently patented by AlliedSignal Engines, which has demonstrated considerably lower leakage than commonly used labyrinth seals and is considerably cheaper than brush seals. The cost to produce finger seals is estimated to be about half of the cost to produce brush seals. Replacing labyrinth seals with fingers seals at locations that have high-pressure drops in gas turbine engines, typically main engine and thrust seals, can reduce air leakage at each location by 50 percent or more. This directly results in a 0.7- to 1.4-percent reduction in specific fuel consumption and a 0.35- to 0.7-percent reduction in direct operating costs . Because the finger seal is a contacting seal, this testing was conducted to address concerns about its heat generation and life capability at the higher speeds and temperatures required for advanced engines. The test results showed that the seal leakage and wear performance are acceptable for advanced engines.

  15. Fluid-driven fingering instability of a confined elastic meniscus

    NASA Astrophysics Data System (ADS)

    Biggins, John S.; Wei, Z.; Mahadevan, L.

    2015-05-01

    When a fluid is pumped into a cavity in a confined elastic layer, at a critical pressure, destabilizing fingers of fluid invade the elastic solid along its meniscus (Saintyves B. et al., Phys. Rev. Lett., 111 (2013) 047801). These fingers occur without fracture or loss of adhesion and are reversible, disappearing when the pressure is decreased. We develop an asymptotic theory of pressurized highly elastic layers trapped between rigid bodies in both rectilinear and circular geometries, with predictions for the critical fluid pressure for fingering, and the finger wavelength. Our results are in good agreement with recent experimental observations of this elastic interfacial instability in a radial geometry. Our theory also shows that, perhaps surprisingly, this lateral-pressure-driven instability is analogous to a transverse-displacement-driven instability of the elastic layer. We verify these predictions by using non-linear finite-element simulations on the two systems which show that in both cases the fingering transition is first order (sudden) and hence has a region of bistability.

  16. Traumatic Finger Injuries: What the Orthopedic Surgeon Wants to Know.

    PubMed

    Wieschhoff, Ged G; Sheehan, Scott E; Wortman, Jeremy R; Dyer, George S M; Sodickson, Aaron D; Patel, Ketan I; Khurana, Bharti

    2016-01-01

    Traumatic finger injuries account for a substantial number of emergency visits every year. Imaging plays an important role in diagnosis and in directing management of these injuries. Although many injuries can be managed conservatively, some require more invasive interventions to prevent complications and loss of function. Accurate diagnosis of finger injuries can often be difficult, given the complicated soft-tissue anatomy of the hand and the diverse spectrum of injuries that can occur. To best serve the patient and the treating physician, radiologists must have a working knowledge of finger anatomy, the wide array of injury patterns that can occur, the characteristic imaging findings of different finger injuries, and the most appropriate treatment options for each type of injury. This article details the intricate anatomy of the hand as it relates to common finger injuries, illustrates the imaging findings of a range of injuries, presents optimal imaging modalities and imaging parameters for the diagnosis of different injury types, and addresses which findings have important management implications for the patient and the orthopedic surgeon. With this fund of knowledge, radiologists will be able to recommend the most appropriate imaging studies, make accurate diagnoses, convey clinically relevant imaging findings to the referring physician, and suggest appropriate follow-up examinations. In this way, the radiologist will help improve patient care and outcomes. Online supplemental material is available for this article. (©)RSNA, 2016. PMID:27399238

  17. RNA binding by the Wilms tumor suppressor zinc finger proteins.

    PubMed Central

    Caricasole, A; Duarte, A; Larsson, S H; Hastie, N D; Little, M; Holmes, G; Todorov, I; Ward, A

    1996-01-01

    The Wilms tumor suppressor gene WT1 is implicated in the ontogeny of genito-urinary abnormalities, including Denys-Drash syndrome and Wilms tumor of the kidney. WT1 encodes Kruppel-type zinc finger proteins that can regulate the expression of several growth-related genes, apparently by binding to specific DNA sites located within 5' untranslated leader regions as well as 5' promoter sequences. Both WT1 and a closely related early growth response factor, EGR1, can bind the same DNA sequences from the mouse gene encoding insulin-like growth factor 2 (Igf-2). We report that WT1, but not EGR1, can bind specific Igf-2 exonic RNA sequences, and that the zinc fingers are required for this interaction. WT1 zinc finger 1, which is not represented in EGR1, plays a more significant role in RNA binding than zinc finger 4, which does have a counterpart in EGR1. Furthermore, the normal subnuclear localization of WT1 proteins is shown to be RNase, but not DNase, sensitive. Therefore, WT1 might, like the Kruppel-type zinc finger protein TFIIIA, regulate gene expression by both transcriptional and posttranscriptional mechanisms. Images Fig. 1 Fig. 2 Fig. 3 PMID:8755514

  18. Finger Vein Recognition Based on Personalized Weight Maps

    PubMed Central

    Yang, Gongping; Xiao, Rongyang; Yin, Yilong; Yang, Lu

    2013-01-01

    Finger vein recognition is a promising biometric recognition technology, which verifies identities via the vein patterns in the fingers. Binary pattern based methods were thoroughly studied in order to cope with the difficulties of extracting the blood vessel network. However, current binary pattern based finger vein matching methods treat every bit of feature codes derived from different image of various individuals as equally important and assign the same weight value to them. In this paper, we propose a finger vein recognition method based on personalized weight maps (PWMs). The different bits have different weight values according to their stabilities in a certain number of training samples from an individual. Firstly we present the concept of PWM, and then propose the finger vein recognition framework, which mainly consists of preprocessing, feature extraction, and matching. Finally, we design extensive experiments to evaluate the effectiveness of our proposal. Experimental results show that PWM achieves not only better performance, but also high robustness and reliability. In addition, PWM can be used as a general framework for binary pattern based recognition. PMID:24025556

  19. The biometric recognition on contactless multi-spectrum finger images

    NASA Astrophysics Data System (ADS)

    Kang, Wenxiong; Chen, Xiaopeng; Wu, Qiuxia

    2015-01-01

    This paper presents a novel multimodal biometric system based on contactless multi-spectrum finger images, which aims to deal with the limitations of unimodal biometrics. The chief merits of the system are the richness of the permissible texture and the ease of data access. We constructed a multi-spectrum instrument to simultaneously acquire three different types of biometrics from a finger: contactless fingerprint, finger vein, and knuckleprint. On the basis of the samples with these characteristics, a moderate database was built for the evaluation of our system. Considering the real-time requirements and the respective characteristics of the three biometrics, the block local binary patterns algorithm was used to extract features and match for the fingerprints and finger veins, while the Oriented FAST and Rotated BRIEF algorithm was applied for knuckleprints. Finally, score-level fusion was performed on the matching results from the aforementioned three types of biometrics. The experiments showed that our proposed multimodal biometric recognition system achieves an equal error rate of 0.109%, which is 88.9%, 94.6%, and 89.7% lower than the individual fingerprint, knuckleprint, and finger vein recognitions, respectively. Nevertheless, our proposed system also satisfies the real-time requirements of the applications.

  20. Prior Knowledge Improves Decoding of Finger Flexion from Electrocorticographic Signals

    PubMed Central

    Wang, Z.; Ji, Q.; Miller, K. J.; Schalk, Gerwin

    2011-01-01

    Brain–computer interfaces (BCIs) use brain signals to convey a user’s intent. Some BCI approaches begin by decoding kinematic parameters of movements from brain signals, and then proceed to using these signals, in absence of movements, to allow a user to control an output. Recent results have shown that electrocorticographic (ECoG) recordings from the surface of the brain in humans can give information about kinematic parameters (e.g., hand velocity or finger flexion). The decoding approaches in these studies usually employed classical classification/regression algorithms that derive a linear mapping between brain signals and outputs. However, they typically only incorporate little prior information about the target movement parameter. In this paper, we incorporate prior knowledge using a Bayesian decoding method, and use it to decode finger flexion from ECoG signals. Specifically, we exploit the constraints that govern finger flexion and incorporate these constraints in the construction, structure, and the probabilistic functions of the prior model of a switched non-parametric dynamic system (SNDS). Given a measurement model resulting from a traditional linear regression method, we decoded finger flexion using posterior estimation that combined the prior and measurement models. Our results show that the application of the Bayesian decoding model, which incorporates prior knowledge, improves decoding performance compared to the application of a linear regression model, which does not incorporate prior knowledge. Thus, the results presented in this paper may ultimately lead to neurally controlled hand prostheses with full fine-grained finger articulation. PMID:22144944

  1. Review of Acute Traumatic Closed Mallet Finger Injuries in Adults

    PubMed Central

    Salazar Botero, Santiago; Hidalgo Diaz, Juan Jose; Benaïda, Anissa; Collon, Sylvie; Facca, Sybille

    2016-01-01

    In adults, mallet finger is a traumatic zone I lesion of the extensor tendon with either tendon rupture or bony avulsion at the base of the distal phalanx. High-energy mechanisms of injury generally occur in young men, whereas lower energy mechanisms are observed in elderly women. The mechanism of injury is an axial load applied to a straight digit tip, which is then followed by passive extreme distal interphalangeal joint (DIPJ) hyperextension or hyperflexion. Mallet finger is diagnosed clinically, but an X-ray should always be performed. Tubiana's classification takes into account the size of the bony articular fragment and DIPJ subluxation. We propose to stage subluxated fractures as stage III if the subluxation is reducible with a splint and as stage IV if not. Left untreated, mallet finger becomes chronic and leads to a swan-neck deformity and DIPJ osteoarthritis. The goal of treatment is to restore active DIPJ extension. The results of a six- to eight-week conservative course of treatment with a DIPJ splint in slight hyperextension for tendon lesions or straight for bony avulsions depends on patient compliance. Surgical treatments vary in terms of the approach, the reduction technique, and the means of fixation. The risks involved are stiffness, septic arthritis, and osteoarthritis. Given the lack of consensus regarding indications for treatment, we propose to treat all cases of mallet finger with a dorsal glued splint except for stage IV mallet finger, which we treat with extra-articular pinning. PMID:27019806

  2. Prediction of contact forces of underactuated finger by adaptive neuro fuzzy approach

    NASA Astrophysics Data System (ADS)

    Petković, Dalibor; Shamshirband, Shahaboddin; Abbasi, Almas; Kiani, Kourosh; Al-Shammari, Eiman Tamah

    2015-12-01

    To obtain adaptive finger passive underactuation can be used. Underactuation principle can be used to adapt shapes of the fingers for grasping objects. The fingers with underactuation do not require control algorithm. In this study a kinetostatic model of the underactuated finger mechanism was analyzed. The underactuation is achieved by adding the compliance in every finger joint. Since the contact forces of the finger depend on contact position of the finger and object, it is suitable to make a prediction model for the contact forces in function of contact positions of the finger and grasping objects. In this study prediction of the contact forces was established by a soft computing approach. Adaptive neuro-fuzzy inference system (ANFIS) was applied as the soft computing method to perform the prediction of the finger contact forces.

  3. Development of cylindrical-type finger force measuring system using force sensors and its characteristics evaluation

    NASA Astrophysics Data System (ADS)

    Kim, Hyeon-Min; Yoon, Joungwon; Shin, Hee-Suk; Kim, Gab-Soon

    2012-02-01

    Some patients cannot use their hands because of the paralysis of their fingers. Their fingers can recover with rehabilitative training, and the extent of rehabilitation can be judged by grasping a cylindrical-object with their fingers. At present, the cylindrical-object used in hospitals is only a plastic cylinder, which cannot measure grasping force of the fingers. Therefore, doctors must judge the extent of rehabilitation by watching patients' fingers as they grasp the plastic cylinder. In this paper, the development of two cylindrical-type finger force measuring systems with four force sensors for left hand and right hand were developed. The developed finger force measuring system can measure the grasping force of patients' each finger (forefinger, middle finger, ring finger and little finger), and the measured results could be used to judge the rehabilitation extent of a finger patient. The grasping force tests of men and women were performed using the developed cylindrical-type finger force measuring systems. The tests confirm that the average finger forces of right hand and left hand for men were about 194 N and 179 N, and for women, 108 N and 95 N.

  4. Index and ring finger ratio--a morphologic sex determinant in South-Indian children.

    PubMed

    Kanchan, Tanuj; Pradeep Kumar, G

    2010-12-01

    To investigate the sexual dimorphism of index and ring finger ratio in South Indian children. The index finger length (IFL) and the ring finger length (RFL) were measured in 350 subjects aged between 2 and 12 years using a steel measuring tape. The index and ring finger ratio was computed by dividing index finger length by ring finger length. The data obtained were analyzed statistically using SPSS, version 11.0. Mean RFL was greater than mean IFL in both males and females. The mean ring finger length was longer in males than females and mean index finger length longer in females than males. However, these sex differences observed for index and ring finger length were not significant in both hands. Statistically significant sex differences were observed from the derived index and ring finger ratio. The mean index and ring finger ratio was found to be higher in females than males. Significant correlation was found between age and index and ring finger lengths. Index and ring finger ratio however, did not show any significant correlation with age. This study suggests that among South-Indian children, the index and ring finger ratio of 0.97 and less is indicative of male, and a ratio of more than 0.97 is indicative of female sex. The ratio can be a useful sex indicator irrespective of the age of the individual. PMID:20369311

  5. Relative contributions of neural mechanisms versus muscle mechanics in promoting finger extension deficits following stroke.

    PubMed

    Kamper, D G; Harvey, R L; Suresh, S; Rymer, W Z

    2003-09-01

    The origins of impaired finger and hand function were examined in 10 stroke survivors with chronic spastic hemiparesis, with the intent of assessing whether mechanical restraint or altered neurophysiological control mechanisms are responsible for the well-known impairment of finger extension. Simultaneous extension of all four metacarpophalangeal (MCP) joints of the impaired hand was either externally imposed using a rotary actuator or attempted voluntarily by the subject. Trials were conducted both before and after administration of a local anesthetic, blocking the median and ulnar nerves at the elbow. The anesthetic was administered to reduce the activity of the muscles flexing the MCP joints, in order to distinguish mechanical from neuronal resistance to imposed MCP rotation. We found that the nerve blockade resulted in a reduction in velocity-dependent torque (P = 0.01), thereby indicating significant joint impedance due to spasticity. Blockade also produced a posture-dependent reduction in static torque in declaratively relaxed subjects (P = 0.04), suggesting some tonic flexor activity for specific hand postures. No change in either extensor isometric (P = 0.33) or isokinetic (0.53) torque was apparent, but 3 of the 10 subjects did exhibit substantial (>10 degrees ) improvement in voluntary MCP extension following the blockade. This improvement seemed largely due to a decrease in inappropriate flexor activity during the movement, rather than an increase in extensor activity. We argue that persistent and inappropriate flexor activation plays a role in limiting voluntary finger extension, and that this activation is potentially a reflection of altered supraspinal control of key spinal pathways. In all cases, this inappropriate activation was compounded by weakness, apparent in both the extensor and flexor muscles. PMID:12929190

  6. Targeted Mutagenesis in Zebrafish Using Customized Zinc Finger Nucleases

    PubMed Central

    Foley, Jonathan E.; Maeder, Morgan L.; Pearlberg, Joseph; Joung, J. Keith; Peterson, Randall T.; Yeh, Jing-Ruey J.

    2009-01-01

    Zebrafish mutants have traditionally been obtained using random mutagenesis or retroviral insertions, methods that cannot be targeted to a specific gene and require laborious gene mapping and sequencing. Recently, we and others have shown that customized zinc finger nucleases (ZFNs) can introduce targeted frame-shift mutations with high efficiency, thereby enabling directed creation of zebrafish gene mutations. Here we describe a detailed protocol for constructing ZFN expression vectors, for generating and introducing ZFN-encoding RNAs into zebrafish embryos, and for identifying ZFN-generated mutations in targeted genomic sites. All of our vectors and methods are compatible with previously described Zinc Finger Consortium reagents for constructing engineered zinc finger arrays. Using these methods, zebrafish founders carrying targeted mutations can be identified within four months. PMID:20010934

  7. Initial results of finger imaging using photoacoustic computed tomography

    NASA Astrophysics Data System (ADS)

    van Es, Peter; Biswas, Samir K.; Moens, Hein J. Bernelot; Steenbergen, Wiendelt; Manohar, Srirang

    2014-06-01

    We present a photoacoustic computed tomography investigation on a healthy human finger, to image blood vessels with a focus on vascularity across the interphalangeal joints. The cross-sectional images were acquired using an imager specifically developed for this purpose. The images show rich detail of the digital blood vessels with diameters between 100 μm and 1.5 mm in various orientations and at various depths. Different vascular layers in the skin including the subpapillary plexus could also be visualized. Acoustic reflections on the finger bone of photoacoustic signals from skin were visible in sequential slice images along the finger except at the location of the joint gaps. Not unexpectedly, the healthy synovial membrane at the joint gaps was not detected due to its small size and normal vascularization. Future research will concentrate on studying digits afflicted with rheumatoid arthritis to detect the inflamed synovium with its heightened vascularization, whose characteristics are potential markers for disease activity.

  8. Prognostic factors on survival rate of fingers replantation

    PubMed Central

    Lima, José Queiroz; Carli, Alberto De; Nakamoto, Hugo Alberto; Bersani, Gustavo; Crepaldi, Bruno Eiras; de Rezende, Marcelo Rosa

    2015-01-01

    Objective: To evaluate the factors that influence the survival rate of replantation and revascularization of the thumb and/or fingers. Methods: We included fifty cases treated in our department from May 2012 to October 2013 with total or partial finger amputations, which had blood perfusion deficit and underwent vascular anastomosis. The parameters evaluated were: age, gender, comorbidities, trauma, time and type of ischemia, mechanism, the injured area, number of anastomosed vessels and use of vein grafts. The results were statistically analyzed and type I error value was set at p <0.05 . Results: Fifty four percent of the 50 performed replantation survived. Of 15 revascularizations performed, the survival rate was 93.3%. The only factor that affected the survival of the amputated limb was the necessity of venous anastomosis. Conclusion: We could not establish contraindications or absolute indications for the replantation and revascularization of finger amputations in this study. Level of Evidence III, Retropective Study. PMID:26327788

  9. Arthropathy, ankylosing spondylitis, and clubbing of fingers in ulcerative colitis

    PubMed Central

    Jalan, K. N.; Prescott, R. J.; Walker, R. J.; Sircus, W.; McManus, J. P. A.; Card, W. I.

    1970-01-01

    In a retrospective study of 399 patients with ulcerative colitis, 27 patients had colitic arthritis, 17 had ankylosing spondylitis, and 20 had clubbing of the fingers. Colitic arthritis and ankylosing spondylitis were not related to severity, extent of involvement, or duration of colitis. A significant association between colitic arthropathy and other complications of ulcerative colitis, such as pseudopolyposis, perianal disease, eye lesions, skin eruptions, aphthous ulceration, and liver disease has been demonstrated. The outcome of the first referred attack of colitis in the presence of colitic arthritis and ankylosing spondylitis remained uninfluenced. Clubbing of fingers was related to severity, extent of involvement, and length of the history of colitis. A significant association between clubbing of the fingers and carcinoma of the colon, pseudopolyposis, toxic dilatation, and arthropathy has been shown. The frequency of surgical intervention in patients with clubbing was higher but the overall mortality was not significantly different from the patients without clubbing. PMID:5473606

  10. High-Speed, High-Temperature Finger Seal Test Results

    NASA Technical Reports Server (NTRS)

    Proctor, Margaret P.; Kumar, Arun; Delgado, Irebert R.

    2002-01-01

    Finger seals have significantly lower leakage rates than conventional labyrinth seals used in gas turbine engines and are expected to decrease specific fuel consumption by over 1 percent and to decrease direct operating cost by over 0.5 percent. Their compliant design accommodates shaft growth and motion due to thermal and dynamic loads with minimal wear. The cost to fabricate these finger seals is estimated to be about half the cost to fabricate brush seals. A finger seal has been tested in NASA's High Temperature, High Speed Turbine Seal Test Rig at operating conditions up to 1200 F, 1200 ft/s, and 75 psid. Static, performance and endurance test results are presented. While seal leakage and wear performance are acceptable, further design improvements are needed to reduce the seal power loss.

  11. Regulation of cancer stem cells by RING finger ubiquitin ligases

    PubMed Central

    Sun, Xiao-Hong

    2014-01-01

    Like normal stem cells, cancer stem cells (CSCs) are capable of self-renewal, either by symmetric or asymmetric cell division. They have the exclusive ability to reproduce malignant tumors indefinitely, and to confer resistance in response to radiation or chemotherapy. The ubiquitin modification system plays various roles in physiology and pathology. The key component for the specificity of this system is ubiquitin ligases (E3s). Of these E3s, the majority are RING finger proteins. Many RING finger E3s, such as the Cullin1-Skp1-F-box protein (SCF) E3s, CBL, BRCA1, MDM2 and von Hippel-Lindau tumour suppressor (VHL), are crucial in the regulation of cell-cycle progression and cell differentiation. As a result, many RING finger E3s are implicated in the positive and negative regulation of CSC maintenance. This review summarizes current knowledge in this research field. PMID:27358852

  12. Finger Pricking and Pain: A Never Ending Story

    PubMed Central

    Heinemann, Lutz

    2008-01-01

    Without finger pricking, no self-measurement of blood glucose (SMBG) is possible. However, the number of scientific studies dealing with this topic, which is highly relevant for patients, is surprisingly small. This is in sharp contrast to the number of papers about blood glucose meters and SMBG in general. This article highlights a number of aspects that are relevant when it comes to finger pricking and pain. There is a clear improvement in the technology employed in the many different lancing devices that are on the market nowadays; however, no good head-to-head comparison study has been performed to date. The invention of novel devices for finger pricking will most likely bring more attention to this topic. PMID:19885279

  13. Finger sudorometry and assessment of the sudomotor drive.

    PubMed

    Satchell, P; Ware, S; Barron, J; Tuck, R

    1994-08-01

    Sudorometry of the finger was carried out using the ventilated capsule method, the aim being to use the level of relative humidity within the sudorometer as an indirect measure of the sudomotor drive. Subjects inserted a finger through a diaphragm of a finger-shaped, temperature-controlled chamber which also contained the humidity sensor. Manoeuvres known to alter the sudomotor drive produced changes in chamber humidity. The relative humidity within the sudorometer became constant after local anaesthesia of the digital nerves and after upper limb sympathectomy, suggesting that fluctuations in the sudorometer output were dependent upon an intact autonomic nervous system. In an environment in which temperature was controlled and arousal effects from the process of measurement were minimised, chamber humidity always increased during a Stroop test, providing a rapid means of indirectly assessing sudomotor drive mechanisms. PMID:7823624

  14. Effect of transcranial magnetic stimulation on force of finger pinch

    NASA Astrophysics Data System (ADS)

    Odagaki, Masato; Fukuda, Hiroshi; Hiwaki, Osamu

    2009-04-01

    Transcranial magnetic stimulation (TMS) is used to explore many aspects of brain function, and to treat neurological disorders. Cortical motor neuronal activation by TMS over the primary motor cortex (M1) produces efferent signals that pass through the corticospinal tracts. Motor-evoked potentials (MEPs) are observed in muscles innervated by the stimulated motor cortex. TMS can cause a silent period (SP) following MEP in voluntary electromyography (EMG). The present study examined the effects of TMS eliciting MEP and SP on the force of pinching using two fingers. Subjects pinched a wooden block with the thumb and index finger. TMS was applied to M1 during the pinch task. EMG of first dorsal interosseous muscles and pinch forces were measured. Force output increased after the TMS, and then oscillated. The results indicated that the motor control system to keep isotonic forces of the muscles participated in the finger pinch was disrupted by the TMS.

  15. Finger Vein Recognition Based on a Personalized Best Bit Map

    PubMed Central

    Yang, Gongping; Xi, Xiaoming; Yin, Yilong

    2012-01-01

    Finger vein patterns have recently been recognized as an effective biometric identifier. In this paper, we propose a finger vein recognition method based on a personalized best bit map (PBBM). Our method is rooted in a local binary pattern based method and then inclined to use the best bits only for matching. We first present the concept of PBBM and the generating algorithm. Then we propose the finger vein recognition framework, which consists of preprocessing, feature extraction, and matching. Finally, we design extensive experiments to evaluate the effectiveness of our proposal. Experimental results show that PBBM achieves not only better performance, but also high robustness and reliability. In addition, PBBM can be used as a general framework for binary pattern based recognition. PMID:22438735

  16. Interfacial instabilities and fingering formation in Hele-Shaw flow

    NASA Astrophysics Data System (ADS)

    Xu, Jian-Jun

    1996-10-01

    The interfacial instability of Hele-Shaw flow has been a crucial issue for the understanding of the pattern formation of viscous fingers in a Hele-Shaw cell. By using a unified asymptotic approach, we derive two different types of instability mechanisms for slightly' time-dependent finger solutions; namely, (i) the global-trapped-wave (GTW) instability; and (ii) the zero-frequency (null-f) instability. On the basis of these instability mechanisms, the selection of viscous finger formation is clarified; the apparent contradiction between the previous linearstability analysis by Tanveer (1987, Phys. Fluid 30, 1589) and others and the numerical simulations by DeGregoria & Schwartz (1986, J. Fluid Mech. 164, 383)and the experimental evidence is reconciled.

  17. First OH reactivity measurements in Harvard Forest

    NASA Astrophysics Data System (ADS)

    Herdlinger-Blatt, I. S.; Martin, S. T.; Hansel, A.; McKinney, K. A.

    2013-12-01

    The OH reactivity provides critical insight into the HOx budget under actual atmospheric conditions, and has implications for the production of ozone and the formation of secondary organic material. Previous studies have indicated that the OH reactivity measured at field sites often exceeds model estimations, but current experiments remain inconclusive about the origin of the discrepancy between the modeled and measured OH reactivity (Lou et al., 2010). As of now there are only a limited number of atmospheric studies of total OH reactivity available, so to improve understanding of the OH reactivity more studies are needed. The first OH reactivity measurements in the northeastern United States are being performed during the summer of 2013 at Harvard Forest. Harvard forest, is located about 100 km west of the Boston metropolitan area, is one of the most intensively studied forests in North America. The main biogenic VOC emitted from Harvard Forest is isoprene followed by monoterpenes and methanol. Sampling for the OH reactivity measurements will be conducted from a 30m tall meteorological tower at the Harvard Forest site. The air is drawn into a reaction cell where the OH reactivity is determined using the Comparative Reactivity Method (Sinha et al., 2008) employing a High-Sensitivity Proton Transfer Reaction Mass Spectrometer (Lindinger et al., 1998, Hansel et al., 1998). In addition to the OH reactivity measurements, the most abundant compounds present in the air sample will be quantified using PTR-MS. The quantification of these compounds is needed to compare the theoretical calculated OH reactivity with the measured OH reactivity data. The measurements will be used to evaluate our understanding of the OH budget at Harvard Forest. References: A. Hansel, A. Jordan, C. Warneke, R. Holzinger, and W. Lindinger.: Improved Detection Limit of the Proton-transfer Reaction Mass Spectrometer: On-line Monitoring of Volatile Organic Compounds at Mixing Ratios of a Few PPTV

  18. Custom-Made Finger Guard to Prevent Wire-Stick Injury to the Operator's Finger while Performing Intermaxillary Fixation

    PubMed Central

    Kumaresan, Ramesh; Ponnusami, Karthikeyan; Karthikeyan, Priyadarshini

    2014-01-01

    The treatment of maxillofacial fractures involves different methods from bandages and splinting to methods of open reduction and internal fixation and usually requires control of the dental occlusion with the help of intermaxillary fixation (IMF). Different wiring techniques have been used to aid in IMF including placement of custom-made arch bars, eyelet etc. However, these wiring techniques are with a constant danger of trauma to the surgeon's fingers by their sharp ends. Though there exist a variety of commercially available barrier products and customized techniques to prevent wire-stick injury, cost factor, touch sensitivity, and comfort aspect restrain their acquirement and exploit. This technical note describes the construction of a simple and economical finger guard made of soft thermoplastic material that provides an added protection to fingers from wire-stick type injuries, and its flexible nature permits a comfortable finger flexion movement and acceptable touch sensitivity. This is a simple, economical, reusable puncture, and cut-resistance figure guard by which we can avoid wire-stick type injury to the operator's fingers during wiring technique. PMID:25383158

  19. Computing with liquid crystal fingers: models of geometric and logical computation.

    PubMed

    Adamatzky, Andrew; Kitson, Stephen; Costello, Ben De Lacy; Matranga, Mario Ariosto; Younger, Daniel

    2011-12-01

    When a voltage is applied across a thin layer of cholesteric liquid crystal, fingers of cholesteric alignment can form and propagate in the layer. In computer simulation, based on experimental laboratory results, we demonstrate that these cholesteric fingers can solve selected problems of computational geometry, logic, and arithmetics. We show that branching fingers approximate a planar Voronoi diagram, and nonbranching fingers produce a convex subdivision of concave polygons. We also provide a detailed blueprint and simulation of a one-bit half-adder functioning on the principles of collision-based computing, where the implementation is via collision of liquid crystal fingers with obstacles and other fingers. PMID:22304104

  20. Continuous non-invasive finger blood pressure monitoring in children.

    PubMed

    Tanaka, H; Thulesius, O; Yamaguchi, H; Mino, M; Konishi, K

    1994-06-01

    We evaluated the performance of continuous non-invasive finger arterial pressure measurement using the volume-clamp technique (Finapres). This study was designed to compare finger arterial pressure with brachial blood pressure estimated by the auscultatory method in 217 children (90 boys and 127 girls) aged 4-16 years and in 38 adults (aged 18-45 years). Finger and brachial artery pressure readings were obtained consecutively from the ipsilateral side in the supine position. Finger arterial pressure waveforms were recorded in all children except 4 with small and thin fingers. There was good agreement for systolic pressure with only a slight underestimation of 1.9 mmHg and 5.1 mmHg lower for diastolic pressure. This difference most probably reflects inaccuracy of the auscultatory cuff method rather than an error in the Finapres. There was large inter-individual variability in Finapres recordings which might be due to differences in vasomotor tone, as demonstrated by systolic amplification in 5 patients with anorexia. However, Finapres showed a small within-subject variability (3.8 mmHg for systolic and 4.1 mmHg for diastolic pressure) determined in 5 patients during phenylephrine infusion, and as good reproducibility as the auscultatory method. These results suggest that finger arterial pressure measurement in children older than 6 years of age has similar accuracy as that in adults, and that this method is useful for clinical applications in children, especially for the non-invasive evaluation of autonomic control and cardiovascular reflexes involving transient and rapid blood pressure changes. PMID:7919764

  1. Finger Tendon Travel Associated with Sequential Trigger Nail Gun Use

    PubMed Central

    Lowe, Brian; Albers, James; Hudock, Stephen; Krieg, Edward

    2015-01-01

    TECHNICAL ABSTRACT Background Pneumatic nail guns used in wood framing are equipped with one of two triggering mechanisms. Sequential actuation triggers have been shown to be a safer alternative to contact actuation triggers because they reduce traumatic injury risk. However, the sequential actuation trigger must be depressed for each individual nail fired as opposed to the contact actuation trigger, which allows the trigger to be held depressed as nails are fired repeatedly by bumping the safety tip against the workpiece. As such, concerns have been raised about risks for cumulative trauma injury, and reduced productivity, due to repetitive finger motion with the sequential actuation trigger. Purpose This study developed a method to predict cumulative finger flexor tendon travel associated with the sequential actuation trigger nail gun from finger joint kinematics measured in the trigger actuation and productivity standards for wood-frame construction tasks. Methods Finger motions were measured from six users wearing an instrumented electrogoniometer glove in a simulation of two common framing tasks–wall building and flat nailing of material. Flexor tendon travel was calculated from the ensemble average kinematics for an individual nail fired. Results Finger flexor tendon travel was attributable mostly to proximal interphalangeal and distal interphalangeal joint motion. Tendon travel per nail fired appeared to be slightly greater for a wall-building task than a flat nailing task. The present study data, in combination with construction industry productivity standards, suggest that a high-production workday would be associated with less than 60 m/day cumulative tendon travel per worker (based on 1700 trigger presses/day). Conclusion and Applications These results suggest that exposure to finger tendon travel from sequential actuation trigger nail gun use may be below levels that have been previously associated with high musculoskeletal disorder risk. PMID

  2. Motor equivalence during multi-finger accurate force production

    PubMed Central

    Mattos, Daniela; Schöner, Gregor; Zatsiorsky, Vladimir M.; Latash, Mark L.

    2014-01-01

    We explored stability of multi-finger cyclical accurate force production action by analysis of responses to small perturbations applied to one of the fingers and inter-cycle analysis of variance. Healthy subjects performed two versions of the cyclical task, with and without an explicit target. The “inverse piano” apparatus was used to lift/lower a finger by 1 cm over 0.5 s; the subjects were always instructed to perform the task as accurate as they could at all times. Deviations in the spaces of finger forces and modes (hypothetical commands to individual fingers) were quantified in directions that did not change total force (motor equivalent) and in directions that changed the total force (non-motor equivalent). Motor equivalent deviations started immediately with the perturbation and increased progressively with time. After a sequence of lifting-lowering perturbations leading to the initial conditions, motor equivalent deviations were dominating. These phenomena were less pronounced for analysis performed with respect to the total moment of force with respect to an axis parallel to the forearm/hand. Analysis of inter-cycle variance showed consistently higher variance in a subspace that did not change the total force as compared to the variance that affected total force. We interpret the results as reflections of task-specific stability of the redundant multi-finger system. Large motor equivalent deviations suggest that reactions of the neuromotor system to a perturbation involve large changes of neural commands that do not affect salient performance variables, even during actions with the purpose to correct those salient variables. Consistency of the analyses of motor equivalence and variance analysis provides additional support for the idea of task-specific stability ensured at a neural level. PMID:25344311

  3. Phenylethynyl endcapping reagents and reactive diluents

    NASA Technical Reports Server (NTRS)

    Jensen, Brian J. (Inventor); Bryant, Robert G. (Inventor); Hergenrother, Paul M. (Inventor)

    1994-01-01

    A phenylethynyl composition which can be used to endcap nucleophilic species is employed in the production of phenylethynyl terminated reactive oligomers exclusively. These phenylethynyl terminated reactive oligomers display unique thermal characteristics, as exemplified by the model compound, 4-phenoxy 4'-phenylethynylbenzophenone, which is relatively stable at 200 C, but reacts at 350 C. In addition, a reactive diluent was prepared which decreases the melt viscosity of the phenylethynyl terminated oligomers and subsequently reacts therewith to increase density of the resulting thermoset. The novelty of this invention resides in the phenylethynyl composition used to terminate a nucleophilic reagent, resulting in the exclusive production of phenylethynyl terminated reactive oligomers which display unique thermal characteristics. A reactive diluent was also employed to decrease the melt viscosity of a phenylethynyl terminated reactive oligomer and to subsequently react therewith to increase the crosslink density of the resulting thermoset. These materials have features which make them attractive candidates for use as composite matrices and adhesives.

  4. [Seal finger in Denmark diagnosed by PCR-technique].

    PubMed

    Jansen, Louise Charlotte; Justesen, Ulrik Stenz; Roos, Signe Moeslund; Dargis, Rimtas; Jensen, Jørgen Skov; Christensen, Jens Jørgen; Kemp, Michael

    2012-02-13

    Seal finger is an unusual infection in Denmark but is seen quite often in Greenland. A 69 year-old Danish man developed severe infection after cutting his finger on a sea urchin while handling a fishing net. Treatment with beta-lactam antibiotics had no effect. Standard culture from the lesion was negative. A Mycoplasma species was detected by PCR and DNA sequencing and subsequently cultured on special media. Specifically asked about exposure to sea mammals the patient could inform that a dead seal had also been trapped in the fishing net. PMID:22331047

  5. Fjords in viscous fingering: selection of width and opening scale

    SciTech Connect

    Mineev-weinstein, Mark; Ristroph, Leif; Thrasher, Matthew; Swinney, Harry

    2008-01-01

    Our experiments on viscous fingering of air into oil contained between closely spaced plates reveal two selection rules for the fjords of oil that separate fingers of air. (Fjords are the building blocks of solutions of the zero-surface-tension Laplacian growth equation.) Experiments in rectangular and circular geometries yield fjords with base widths {lambda}{sub c}/2, where {lambda}{sub c} is the most unstable wavelength from a linear stability analysis. Further, fjords open at an angle of 8.0{sup o}{+-}1.0{sup o}. These selection rules hold for a wide range of pumping rates and fjord lengths, widths, and directions.

  6. GCT of proximal phalanx of ring finger: a case report.

    PubMed

    Khare, Pratima; Kishore, Bimal; Gupta, Rashmi Jain; Vanita; Dhal, Anil

    2012-08-01

    Giant-cell tumor (GCT) of bone arising from phalanx of a finger is extremely rare. Rizzoli Orthopedic Institute in their study on 900 treated cases of GCT from 1947-1997 reported only 0.9% incidence of GCT in bones of the hand. There was no case of GCT of the phalanges in that series. We report here a case of GCT of bone arising from phalanx of finger because of its very unusual location. The tumor was diagnosed on the basis of fine-needle aspiration cytology and confirmed by histopathology. PMID:21656700

  7. Controlling and minimizing fingering instabilities in non-Newtonian fluids

    NASA Astrophysics Data System (ADS)

    Fontana, João V.; Dias, Eduardo O.; Miranda, José A.

    2014-01-01

    The development of the viscous fingering instability in Hele-Shaw cells has great practical and scientific importance. Recently, researchers have proposed different strategies to control the number of interfacial fingering structures, or to minimize as much as possible the amplitude of interfacial disturbances. Most existing studies address the situation in which an inviscid fluid displaces a viscous Newtonian fluid. In this work, we report on controlling and minimizing protocols considering the situation in which the displaced fluid is a non-Newtonian, power-law fluid. The necessary changes on the controlling schemes due to the shear-thinning and shear thickening nature of the displaced fluid are calculated analytically and discussed.

  8. Finger Vein Recognition Using Local Line Binary Pattern

    PubMed Central

    Rosdi, Bakhtiar Affendi; Shing, Chai Wuh; Suandi, Shahrel Azmin

    2011-01-01

    In this paper, a personal verification method using finger vein is presented. Finger vein can be considered more secured compared to other hands based biometric traits such as fingerprint and palm print because the features are inside the human body. In the proposed method, a new texture descriptor called local line binary pattern (LLBP) is utilized as feature extraction technique. The neighbourhood shape in LLBP is a straight line, unlike in local binary pattern (LBP) which is a square shape. Experimental results show that the proposed method using LLBP has better performance than the previous methods using LBP and local derivative pattern (LDP). PMID:22247670

  9. Simultaneous closed dislocation of both interphalangeal joints in one finger.

    PubMed

    Ron, D; Alkalay, D; Torok, G

    1983-01-01

    A rare case of simultaneous dislocation of both interphalangeal joints in one finger in a table-tennis player is presented. The second dislocation took place when the first dislocated joint became the fixed part of the finger as it hit a wall. Treatment was, first, hyperextension to unlock the base of the phalanx, then traction along the phalanx: its base was then pushed into contact with the head of the proximal phalanx. Splinting was applied with the joint in slight flexion. PMID:6823005

  10. The 'reactive

    NASA Astrophysics Data System (ADS)

    Battista Piccardo, Giovanni; Guarnieri, Luisa

    2010-05-01

    The Ligurian ophiolitic peridotites [South Lanzo, Erro-Tobbio, Internal Ligurides and Corsica] are characterized by the abundance of spinel(Sp) peridotites showing depleted compositions and ranging from Cpx-poor Sp lherzolites to Sp harzburgites. They were recognized in the last decades as refractory residua by MORB-forming partial melting of the asthenosphere, and were similar to abyssal peridotites. Recent structural and compositional studies promoted a better understanding of their structural and compositional features and their genetic processes. In the field these depleted peridotites replace with primary contacts pyroxenite-bearing fertile Sp lherzolites that have been recognized as sub-continental lithospheric mantle. Field relationships evidence that decametric-hectometric bodies of pristine pyroxenite-veined lithospheric Sp lherzolites are preserved as structural remnants within the km-scale masses of depleted peridotites. The depleted peridotites show coarse-grained recrystallized textures and reaction micro-structures indicating pyroxene dissolution and olivine precipitation that have been considered as records of melt/peridotite interaction during reactive diffuse porous flow of undersaturated melts. They show, moreover, contrasting bulk and mineral chemistries that cannot be produced by simple partial melting and melt extraction. In particular, their bulk compositions are depleted in SiO2 and enriched in FeO with respect to refractory residua after any kind of partial melting, as calculated by Niu (1997), indicating that they cannot be formed by simple partial melting and melt extraction processes. Moreover, TiO2 content in Sp is usually significantly higher (up to 0.8-1.0 wt%) than typical TiO2 contents of spinels (usually < 0.1-0.2 wt %) in fertile mantle peridotites and melting refractory residua, indicating that spinel attained element equilibration with a Ti-bearing basaltic melt. The depleted peridotites usually show strongly variable Cpx modal

  11. Deleterious effects of reactive metabolites

    PubMed Central

    2010-01-01

    A number of drugs have been withdrawn from the market or severely restricted in their use because of unexpected toxicities that become apparent only after the launch of new drug entities. Circumstantial evidence suggests that, in most cases, reactive metabolites are responsible for these unexpected toxicities. In this review, a general overview of the types of reactive metabolites and the consequences of their formation are presented. The current approaches to evaluate bioactivation potential of new compounds with particular emphasis on the advantages and limitation of these procedures will be discussed. Reasonable reasons for the excellent safety record of certain drugs susceptible to bioactivation will also be explored and should provide valuable guidance in the use of reactive-metabolite assessments when nominating drug candidates for development. This will, in turn, help us to design and bring safer drugs to the market. PMID:20972370

  12. Health benefits of finger millet (Eleusine coracana L.) polyphenols and dietary fiber: a review.

    PubMed

    Devi, Palanisamy Bruntha; Vijayabharathi, Rajendran; Sathyabama, Sathyaseelan; Malleshi, Nagappa Gurusiddappa; Priyadarisini, Venkatesan Brindha

    2014-06-01

    The growing public awareness of nutrition and health care research substantiates the potential of phytochemicals such as polyphenols and dietary fiber on their health beneficial properties. Hence, there is in need to identify newer sources of neutraceuticals and other natural and nutritional materials with the desirable functional characteristics. Finger millet (Eleusine coracana), one of the minor cereals, is known for several health benefits and some of the health benefits are attributed to its polyphenol and dietary fiber contents. It is an important staple food in India for people of low income groups. Nutritionally, its importance is well recognised because of its high content of calcium (0.38%), dietary fiber (18%) and phenolic compounds (0.3-3%). They are also recognized for their health beneficial effects, such as anti-diabetic, anti-tumerogenic, atherosclerogenic effects, antioxidant and antimicrobial properties. This review deals with the nature of polyphenols and dietary fiber of finger millet and their role with respect to the health benefits associated with millet. PMID:24876635

  13. Load-induced changes in older individual's hand-finger tremor are ameliorated with targeting.

    PubMed

    Kavanagh, Justin J; Cross, Troy J; Newell, Karl M; Morrison, Steven

    2014-04-15

    The purpose of this study was to investigate hand-finger tremor dynamics when a load was applied to the finger in a group of healthy older adults. Moreover, we sought to determine if projecting a representation of the subject's finger tremor on a target was capable of overcoming the effects of loading so that hand-finger interactions returned to a state that was similar to normal tremor. Eight healthy older males (67 ± 1 year) performed a postural pointing task, where tremor was assessed using lightweight accelerometers attached to the hand and finger. Tremor was then assessed when a laser pointer was attached to the finger and switched off (the load), and then with the laser pointer attached and switched on pointing at targets of 40 mm and 20mm in diameter. The main findings of this study were that 1) loading the finger resulted in a reduction in finger tremor amplitude and increased finger tremor regularity, but no change in hand tremor, 2) loading caused increased hand-finger 8-12 Hz cross wavelet coherence and phase synchrony, and 3) pointing at different targets while the finger was loaded resulted in an increase in finger tremor amplitude, and changes in inter-segmental coupling to the extent that hand-finger dynamics reflected normal unloaded conditions. Overall, these results illustrate that the damping effects of limb loading can be offset, in part, by altering the accuracy demands of the task to make the pointing action more challenging. PMID:24503237

  14. Zn-, Cd-, and Pb-transcription factor IIIA: properties, DNA binding, and comparison with TFIIIA-finger 3 metal complexes

    PubMed Central

    Huang, Meilin; Krepkiy, Dmitriy; Hu, Weining; Petering, David H.

    2012-01-01

    Properties of the metal ion binding sites of Zn-transcription factor IIIA (TFIIIA) were investigated to understand the potential of this type of zinc finger to undergo reactions that remove Zn2+ from the protein. Zn–TFIIIA was purified from E. coli containing the cloned sequence for Xenopus laevis oocyte TFIIIA and its stoichiometry of bound Zn2+ was shown to depend on the details of the isolation process. The average dissociation constant of Zn2+ in Zn-TFIIIIA was 10−7. The dissociation constant for Zn-F3, the third finger from the N-terminus of TFIIIA, was 1.0 × 10−8. The reactivity of Zn–TFIIIA with a series of metal binding ligands, including 2-carboxy-2′-hydroxy-5′-sulfoformazylbenzene (zincon), 4-(2-pyridylazo)-resorcinol (PAR), and 3-ethoxy-2-oxo-butyraldehyde-bis-(N4-dimethylthiosemicarbazone) (H2KTSM2) revealed similar kinetics. The reactivity of PAR with Zn–TFIIIA declined substantially when the protein was bound to the internal control region (ICR) of the 5S ribosomal DNA. Both Cd2+ and Pb2+ disrupt TFIIIA binding to its cognate DNA sequence. The Pb2+ dissociation constant of Pb-F3 was measured as 2.5 × 10−8. According to NMR spectroscopy, F3 does not fold into a regular conformation in the presence of Pb2+. PMID:15134923

  15. Intensity Variation Normalization for Finger Vein Recognition Using Guided Filter Based Singe Scale Retinex

    PubMed Central

    Xie, Shan Juan; Lu, Yu; Yoon, Sook; Yang, Jucheng; Park, Dong Sun

    2015-01-01

    Finger vein recognition has been considered one of the most promising biometrics for personal authentication. However, the capacities and percentages of finger tissues (e.g., bone, muscle, ligament, water, fat, etc.) vary person by person. This usually causes poor quality of finger vein images, therefore degrading the performance of finger vein recognition systems (FVRSs). In this paper, the intrinsic factors of finger tissue causing poor quality of finger vein images are analyzed, and an intensity variation (IV) normalization method using guided filter based single scale retinex (GFSSR) is proposed for finger vein image enhancement. The experimental results on two public datasets demonstrate the effectiveness of the proposed method in enhancing the image quality and finger vein recognition accuracy. PMID:26184226

  16. An Annotated Bibliography of the Chisanbop Method of Finger Calculation.

    ERIC Educational Resources Information Center

    Dougherty, Mary K.

    The term Chisanbop is the trademark for the finger calculation method originally developed by a Korean, Sung Jin Pai. It was refined and simplified by his son, Hang Young Pai, who introduced the technique to the United States in 1976. This annotated bibliography has been organized in five categories. Readings in the first category, Historical…

  17. 21 CFR 890.5410 - Powered finger exerciser.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Powered finger exerciser. 890.5410 Section 890.5410 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Therapeutic Devices § 890.5410 Powered...

  18. 21 CFR 890.5410 - Powered finger exerciser.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Powered finger exerciser. 890.5410 Section 890.5410 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Therapeutic Devices § 890.5410 Powered...

  19. 21 CFR 890.5410 - Powered finger exerciser.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Powered finger exerciser. 890.5410 Section 890.5410 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Therapeutic Devices § 890.5410 Powered...

  20. 21 CFR 890.5410 - Powered finger exerciser.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Powered finger exerciser. 890.5410 Section 890.5410 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Therapeutic Devices § 890.5410 Powered...

  1. Singing Greeting Card Beeper as a Finger Pulse Sensor

    ERIC Educational Resources Information Center

    Belusic, Gregor; Zupancic, Gregor

    2010-01-01

    We constructed a robust and low-priced finger pulse sensor from a singing greeting card beeper. The beeper outputs the plethysmographic signal, which is indistinguishable from that of commercial grade sensors. The sensor can be used in school for a number of experiments in human cardiovascular physiology.

  2. Movement Kinematics of the Braille-Reading Finger

    ERIC Educational Resources Information Center

    Hughes, Barry

    2011-01-01

    A new means of measuring the movement properties of the braille-reading finger is described and exemplified in an experiment in which experienced readers of braille encountered sentences comprised of keywords in which word and orthographic frequencies were manipulated. These new data are considered in theoretical and practical terms. (Contains 2…

  3. Some Numerical Simulations and an Experimental Investigation of Finger Seals

    NASA Technical Reports Server (NTRS)

    Braun, Minel J.; Smith, Ian; Marie, Hazel

    2007-01-01

    All seal types have been shown to lift effectively, and experience only minor wear during startup. .. The double pad design outperforms previous seals, providing lower operating temperatures, and less leakage at higher pressures. .. Future experimentation at higher pressures, temperatures, and operating speeds will show the full potential of finger sealing technology.

  4. 21 CFR 890.5410 - Powered finger exerciser.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Powered finger exerciser. 890.5410 Section 890.5410 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Therapeutic Devices § 890.5410 Powered...

  5. Finger stiffness or edema as presenting symptoms of eosinophilic fasciitis.

    PubMed

    Suzuki, Shingo; Noda, Kazutaka; Ohira, Yoshiyuki; Shikino, Kiyoshi; Ikusaka, Masatomi

    2015-10-01

    To investigate the clinical features and finger symptoms of eosinophilic fasciitis (EF), we reviewed five patients with EF. The chief complaint was pain, edema and/or stiffness of the extremities. The distal extremities were affected in all patients, and there was also proximal involvement in one patient. One patient had asymmetrical symptoms. All four patients with upper limb involvement had limited range of motion of the wrist joints, and three of them complained of finger symptoms. Two of these three patients showed slight non-pitting edema of the hands, and the other one had subcutaneous induration of the forearm. All four patients with lower limb symptoms had limited range of motion of the ankle joints, and two showed edema or induration of the legs. Inflammatory changes in the joints were not detected in any of the patients. Two patients displayed neither objective induration nor edema, and two patients had muscle tenderness. In conclusion, finger symptoms of patients with EF might be caused by fasciitis of the forearms, which leads to dysfunction of the long finger flexors and extensors as well as slight edema of hands. Limited range of motion of wrist and/or ankle joints indicates sensitively distal muscle dysfunction caused by fasciitis. PMID:26248532

  6. The Three-Fingers Technique: Does It Reduce Test Anxiety?

    ERIC Educational Resources Information Center

    Maycock, George

    The utility of brief exposure to a mental focusing aid, the Three-Fingers Technique (TFT), in reducing test anxiety was studied for 15 college students. One week before their final examination, the students were given a 15-minute classroom introduction to the TFT, part of the Silva Mental Training Method (1983). After the introduction to this…

  7. Viscous and gravitational fingering in multiphase compositional and compressible flow

    NASA Astrophysics Data System (ADS)

    Moortgat, Joachim

    2016-03-01

    Viscous and gravitational fingering refer to flow instabilities in porous media that are triggered by adverse mobility or density ratios, respectively. These instabilities have been studied extensively in the past for (1) single-phase flow (e.g., contaminant transport in groundwater, first-contact-miscible displacement of oil by gas in hydrocarbon production), and (2) multi-phase immiscible and incompressible flow (e.g., water-alternating-gas (WAG) injection in oil reservoirs). Fingering in multiphase compositional and compressible flow has received much less attention, perhaps due to its high computational complexity. However, many important subsurface processes involve multiple phases that exchange species. Examples are carbon sequestration in saline aquifers and enhanced oil recovery (EOR) by gas or WAG injection below the minimum miscibility pressure. In multiphase flow, relative permeabilities affect the mobility contrast for a given viscosity ratio. Phase behavior can also change local fluid properties, which can either enhance or mitigate viscous and gravitational instabilities. This work presents a detailed study of fingering behavior in compositional multiphase flow in two and three dimensions and considers the effects of (1) Fickian diffusion, (2) mechanical dispersion, (3) flow rates, (4) domain size and geometry, (5) formation heterogeneities, (6) gravity, and (7) relative permeabilities. Results show that fingering in compositional multiphase flow is profoundly different from miscible conditions and upscaling techniques used for the latter case are unlikely to be generalizable to the former.

  8. Moving Fingers under a Stick: A Laboratory Activity

    ERIC Educational Resources Information Center

    Massalha, Taha; Lanir, Yuval; Gluck, Paul

    2011-01-01

    We consider a demonstration in which pupils alternately slide and stop their fingers under a long horizontal rod which they support. The changeover is described in terms of the relevant kinetic and static friction. We present a model calculation, performed on a spreadsheet, which clarifies the process and describes graphically the stepwise…

  9. Modification of the Internal Suture Technique for Mallet Finger

    PubMed Central

    Jiang, Bo; Wang, Peiji; Zhang, Yong; Zhao, Jiaju; Dong, Qirong

    2015-01-01

    Abstract This article describes a treatment of tendinous mallet finger deformities using a modified internal suture technique for the stable fixation of the terminal extensor tendon and bone. Between March 2011 and July 2013, 15 patients with mallet fingers who had been treated using this modification were included in this study. The patients included 10 men and 5 women with a mean age of 33 years (range, 19–50 years). Of these patients, 9 had chronic mallet fingers, 3 were unable to comply with a splinting regimen, and 3 had a history of unsuccessful splinting therapy. The mean time between the injury and surgery was 5.5 months (range, 1–15 months). We graded the results using Crawford criteria. The mean follow-up period was 12 months (range, 9–16 months). The mean final active range of motion of the distal interphalangeal joint flexion was 73° (range, 60°–90°). Based on Crawford evaluation criteria, 8 patients were graded as excellent, 6 were graded as good, and 1 was graded as fair. Apart from 2 documented mild nail deformities, no complications were encountered. This modified technique should be considered for the management of a tendinous mallet finger deformity when the internal suture technique is planned. PMID:25674757

  10. Science Fair Report: Flight of the Split-Fingered Fastball.

    ERIC Educational Resources Information Center

    Mitchell, Richard J.

    1991-01-01

    Reports on the results of an eighth grade student's experiments, conducted with a moving car, concerning the aerodynamics of a baseball in flight. Describes the peculiar diving ability of the split-fingered fastball, as well as the dancing and weaving effect of the knuckleball. (JJK)

  11. Dorsal finger joint soft tissue loss: two case reports.

    PubMed

    Bervar, M

    2003-01-01

    This article brings our experience, standpoints and management guidelines for early reconstruction of traumatic soft tissue loss on the dorsal aspect of the finger joints, with the aim of preserving acceptable late functional ability of the hand. Two interesting and unusual cases of reconstruction are presented. PMID:14989334

  12. Trainability of cold induced vasodilatation in fingers and toes.

    PubMed

    Daanen, Hein A M; Koedam, Jens; Cheung, Stephen S

    2012-07-01

    Subjects that repeatedly have to expose the extremities to cold may benefit from a high peripheral temperature to maintain dexterity and tissue integrity. Therefore, we investigated if repeated immersions of a hand and a foot in cold water resulted in increased skin temperatures. Nine male and seven female subjects (mean 20.4; SD 2.2 years) immersed their right (trained) hand and foot simultaneously in 8°C water, 30 min daily for 15 days. During the pre and post-test (days 1 and 15, respectively) the left (untrained) hand and foot were immersed as well. Pain, tactile sensitivity and skin temperatures were measured every day. Mean (SD) toe temperature of the trained foot increased from 9.49°C (0.89) to 10.03°C (1.38) (p < 0.05). The trained hand, however, showed a drop in mean finger temperature from 9.28°C (0.54) to 8.91°C (0.44) (p < 0.001) and the number of cold induced vasodilation (CIVD) reactions decreased from 52% during the first test to 24% during the last test. No significant differences occurred in the untrained extremities. Pain diminished over time and tactile sensitivity decreased with skin temperature. The combination of less CIVD responses in the fingers after training, reduced finger skin temperatures in subjects that did show CIVD and the reduced pain and tactile sensitivity over time may lead to an increased risk for finger cold injuries. It is concluded that repeated cold exposure of the fingers does not lead to favorable adaptations, but may instead increase the injury risk. PMID:22081047

  13. Finger Seal: A Novel Approach to Air to Air Sealing

    NASA Technical Reports Server (NTRS)

    Arora, Gul; Steinetz, Bruce; Proctor, Margaret

    2006-01-01

    The gas turbine industry used a variety of sealing mechanisms to contain and direct secondary flows into and around components for cooling, and to limit leakage into and from bearing and disk cavities. The function of these seals is very important to the component efficiencies and attendant engine performance. Most of these seals are labyrinth seals, which are high-leakage seals that are costly to manufacture. In recent years, brush seals have been introduced which have demonstrated significantly reduced leakage, although they are still expensive and have exhibited wear and hysteresis difficulties. A new innovative concept called finger seal, patented by AlliedSignal, has demonstrated leakage similar to brush seals and is cheaper. The finger seal is comprised of a stack of precision photo-etched sheet metal elements, which allows intricate features to be made at very low cost and with the potential to resist wear and provide the compliance necessary to accomodate rotor excursions. Initial testing in the high-speed/high-temperature seal test facility, at the NASA Lewis Research Center, has corroborated the finger seal performance. The testing also revealed hysteresis problems with the current design. A NASA funded research project is in progress to correct the functional deficiencies of the finger seal and to refine its features to provide sufficient seal life for commercial transport engines and other long-life applications. This research will benefit the aeronautical gas turbine industry as a whole in terms of fuel consumption, operational characteristics, and cost. The first phase of this research to reduce finger seal hysteresis has been in progress for the last one year. This paper presents the results of this research to date. In future the research program will address seal performance, manufacturing, cost and life issues. The research program is expected to be completed by December 1998.

  14. Improving Finger Coordination in Young and Elderly Persons

    PubMed Central

    Wu, Yen-Hsun; Pazin, Nemanja; Zatsiorsky, Vladimir M.; Latash, Mark L.

    2013-01-01

    We studied the effects of a single practice session of a variable task with subject specific adjustments of task difficulty (instability) on indices of multi-finger coordination in young and elderly persons. The main hypothesis was that practicing such a task would lead to contrasting changes in the amounts of two components of variance estimated across repetitive trials within the uncontrolled manifold (UCM) hypothesis: VUCM that had no effect on total force and VORT that affected total force. In addition, we also expected to see strong transfer effects to a different task. A variable task with graded instability was designed to encourage use of variable solutions during the accurate production of total force with two fingers. The subjects practiced with the index and middle fingers pressing on individual force sensors. Overall, the older subjects showed lower indices of performance and higher indices of both VUCM and VORT. After about one hour of practice, both groups showed an increase in the index of involuntary force production by non-task fingers (enslaving). Both groups improved the indices of performance. The two variance indices showed opposite effects of practice: VORT dropped with practice while VUCM increased leading to an increase in the total amount of variance in the space of commands to fingers and in the index of force-stabilizing synergy. Performance in a simpler, non-practiced task improved, but there was no transfer of the changes in the structure of variance. Specifically, both variance components, VORT and VUCM, dropped in the non-practiced task. The results show that the neural system responsible for synergies stabilizing important features of performance is highly adaptable to practice of tasks designed to encourage use of variable solutions. We view the results as highly promising for future use in populations with impaired coordination characterized by low synergy indices. PMID:23411675

  15. Multi-finger prehension: control of a redundant mechanical system.

    PubMed

    Latash, Mark L; Zatsiorsky, Vladimir M

    2009-01-01

    The human hand has been a fascinating object of study for researchers in both biomechanics and motor control. Studies of human prehension have contributed significantly to the progress in addressing the famous problem of motor redundancy. After a brief review of the hand mechanics, we present results of recent studies that support a general view that the apparently redundant design of the hand is not a source of computational problems but a rich apparatus that allows performing a variety of tasks in a reliable and flexible way (the principle of abundance). Multi-digit synergies have been analyzed at two levels of a hypothetical hierarchy involved in the control of prehensile actions. At the upper level, forces and moments produced by the thumb and virtual finger (an imagined finger with a mechanical action equal to the combined mechanical action of all four fingers of the hand) co-vary to stabilize the gripping action and the orientation of the hand-held object. These results support the principle of superposition suggested earlier in robotics with respect to the control of artificial grippers. At the lower level of the hierarchy, forces and moments produced by individual fingers co-vary to stabilize the magnitude and direction of the force vector and the moment of force produced by the virtual finger. Adjustments to changes in task constraints (such as, for example, friction under individual digits) may be local and synergic. The latter reflect multi-digit prehension synergies and may be analyzed with the so-called chain effects: Sequences of relatively straightforward cause-effect links directly related to mechanical constraints leading to non-trivial strong co-variation between pairs of elemental variables. Analysis of grip force adjustments during motion of hand-held objects suggests that the central nervous system adjusts to gravitational and inertial loads differently. The human hand is a gold mine for researchers interested in the control of natural human

  16. Preliminary Test Results of a Non-Contacting Finger Seal on a Herringbone-Grooved Rotor

    NASA Technical Reports Server (NTRS)

    Proctor, Margaret P.; Delgado, Irebert R.

    2009-01-01

    The baseline non-contacting finger seal is a NASA patented design. The primary difference between it and Gul Aroras design patented by AlliedSignal is that there are no lift pads on the high pressure fingers. The baseline non-contacting finger seal is comprised of a back plate, aft spacer, aft (or low pressure) finger element, forward (or high pressure) finger element, forward spacer, and front plate. The components are held together with 20 flat head screws. A typical seal would have a back plate of approximately the same thickness as the front plate and would be riveted together. The thicker back plate allows use of threaded fasteners so that different finger elements can be tested without having to replace all the individual seal components. The finger elements are essentially washers made of thin sheet stock with multiple curved slots machined around the inner diameter to form the fingers. They are clocked so that the fingers of one cover the slots of the other. The aft finger element fingers have axial extensions or "lift pads" at the seal id that are concentric to the rotor. The fingers act as cantilever beams and flex in response to rotor dynamic motion and radial growth of the rotor due to centrifugal or thermal forces.

  17. 21 CFR 888.3200 - Finger joint metal/metal constrained uncemented prosthesis.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Finger joint metal/metal constrained uncemented... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3200 Finger joint metal/metal constrained uncemented prosthesis. (a) Identification. A finger joint...

  18. 21 CFR 888.3220 - Finger joint metal/polymer constrained cemented prosthesis.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Finger joint metal/polymer constrained cemented... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3220 Finger joint metal/polymer constrained cemented prosthesis. (a) Identification. A finger joint...

  19. 21 CFR 888.3220 - Finger joint metal/polymer constrained cemented prosthesis.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Finger joint metal/polymer constrained cemented... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3220 Finger joint metal/polymer constrained cemented prosthesis. (a) Identification. A finger joint...

  20. 40 CFR 81.128 - Genesee-Finger Lakes Intrastate Air Quality Control Region.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 18 2012-07-01 2012-07-01 false Genesee-Finger Lakes Intrastate Air... Air Quality Control Regions § 81.128 Genesee-Finger Lakes Intrastate Air Quality Control Region. The Genesee-Finger Lakes Intrastate Air Quality Control Region (New York) consists of the territorial...

  1. 40 CFR 81.128 - Genesee-Finger Lakes Intrastate Air Quality Control Region.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 18 2014-07-01 2014-07-01 false Genesee-Finger Lakes Intrastate Air... Air Quality Control Regions § 81.128 Genesee-Finger Lakes Intrastate Air Quality Control Region. The Genesee-Finger Lakes Intrastate Air Quality Control Region (New York) consists of the territorial...

  2. 21 CFR 888.3200 - Finger joint metal/metal constrained uncemented prosthesis.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Finger joint metal/metal constrained uncemented... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3200 Finger joint metal/metal constrained uncemented prosthesis. (a) Identification. A finger joint...

  3. 21 CFR 888.3200 - Finger joint metal/metal constrained uncemented prosthesis.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Finger joint metal/metal constrained uncemented... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3200 Finger joint metal/metal constrained uncemented prosthesis. (a) Identification. A finger joint...

  4. 21 CFR 888.3210 - Finger joint metal/metal constrained cemented prosthesis.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Finger joint metal/metal constrained cemented... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3210 Finger joint metal/metal constrained cemented prosthesis. (a) Identification. A finger joint metal/metal...

  5. 21 CFR 888.3220 - Finger joint metal/polymer constrained cemented prosthesis.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Finger joint metal/polymer constrained cemented... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3220 Finger joint metal/polymer constrained cemented prosthesis. (a) Identification. A finger joint...

  6. An Experimental Study on Preventing First Graders from Finger Counting in Basic Calculations

    ERIC Educational Resources Information Center

    Albayrak, Mustafa

    2010-01-01

    Introduction: When counting is taught to students at primary stage of schooling, they are generally allowed to use their fingers as a counting tool. Therefore, some students continue using their fingers to count, while others stop this habit later. The students who have the habit of using their fingers to count have difficulty when their fingers…

  7. 40 CFR 81.128 - Genesee-Finger Lakes Intrastate Air Quality Control Region.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 17 2010-07-01 2010-07-01 false Genesee-Finger Lakes Intrastate Air... Air Quality Control Regions § 81.128 Genesee-Finger Lakes Intrastate Air Quality Control Region. The Genesee-Finger Lakes Intrastate Air Quality Control Region (New York) consists of the territorial...

  8. 76 FR 77769 - North Finger Grazing Authorization Project, Malheur National Forest, Grant County, OR

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-14

    ... Forest Service North Finger Grazing Authorization Project, Malheur National Forest, Grant County, OR... North Finger Landscape. These allotments are within the Upper Deer Creek, Basin Creek, Upper Long Creek, Lower Fox Creek, Upper Fox Creek, and Upper Cottonwood Creek subwatersheds. The North Finger...

  9. 21 CFR 888.3210 - Finger joint metal/metal constrained cemented prosthesis.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Finger joint metal/metal constrained cemented... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3210 Finger joint metal/metal constrained cemented prosthesis. (a) Identification. A finger joint metal/metal...

  10. 40 CFR 81.128 - Genesee-Finger Lakes Intrastate Air Quality Control Region.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 18 2013-07-01 2013-07-01 false Genesee-Finger Lakes Intrastate Air... Air Quality Control Regions § 81.128 Genesee-Finger Lakes Intrastate Air Quality Control Region. The Genesee-Finger Lakes Intrastate Air Quality Control Region (New York) consists of the territorial...

  11. 21 CFR 888.3210 - Finger joint metal/metal constrained cemented prosthesis.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Finger joint metal/metal constrained cemented... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3210 Finger joint metal/metal constrained cemented prosthesis. (a) Identification. A finger joint metal/metal...

  12. 40 CFR 81.128 - Genesee-Finger Lakes Intrastate Air Quality Control Region.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 17 2011-07-01 2011-07-01 false Genesee-Finger Lakes Intrastate Air... Air Quality Control Regions § 81.128 Genesee-Finger Lakes Intrastate Air Quality Control Region. The Genesee-Finger Lakes Intrastate Air Quality Control Region (New York) consists of the territorial...

  13. 78 FR 35098 - Proposed Information Collection (Hand and Finger Disability Benefits Questionnaire) Activity...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-11

    ... AFFAIRS Proposed Information Collection (Hand and Finger Disability Benefits Questionnaire) Activity... . Please refer to ``OMB Control No. 2900-NEW (Hand or Finger Disability Benefits Questionnaire)'' in any.... Title: Hand and Finger Disability Benefits Questionnaire, VA Form 21-0960M-7. OMB Control Number:...

  14. 21 CFR 888.3220 - Finger joint metal/polymer constrained cemented prosthesis.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Finger joint metal/polymer constrained cemented... metal/polymer constrained cemented prosthesis. (a) Identification. A finger joint metal/polymer..., 1996 for any finger joint metal/polymer constrained cemented prosthesis that was in...

  15. 21 CFR 888.3220 - Finger joint metal/polymer constrained cemented prosthesis.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Finger joint metal/polymer constrained cemented... metal/polymer constrained cemented prosthesis. (a) Identification. A finger joint metal/polymer..., 1996 for any finger joint metal/polymer constrained cemented prosthesis that was in...

  16. Method for reactivating solid catalysts used in alkylation reactions

    DOEpatents

    Ginosar, Daniel M.; Thompson, David N.; Coates, Kyle; Zalewski, David J.; Fox, Robert V.

    2003-06-17

    A method for reactivating a solid alkylation catalyst is provided which can be performed within a reactor that contains the alkylation catalyst or outside the reactor. Effective catalyst reactivation is achieved whether the catalyst is completely deactivated or partially deactivated. A fluid reactivating agent is employed to dissolve catalyst fouling agents and also to react with such agents and carry away the reaction products. The deactivated catalyst is contacted with the fluid reactivating agent under pressure and temperature conditions such that the fluid reactivating agent is dense enough to effectively dissolve the fouling agents and any reaction products of the fouling agents and the reactivating agent. Useful pressures and temperatures for reactivation include near-critical, critical, and supercritical pressures and temperatures for the reactivating agent. The fluid reactivating agent can include, for example, a branched paraffin containing at least one tertiary carbon atom, or a compound that can be isomerized to a molecule containing at least one tertiary carbon atom.

  17. Method For Reactivating Solid Catalysts Used For Alklation Reactions

    DOEpatents

    Ginosar, Daniel M.; Thompson, David N.; Coates, Kyle; Zalewski, David J.; Fox, Robert V.

    2005-05-03

    A method for reactivating a solid alkylation catalyst is provided which can be performed within a reactor that contains the alkylation catalyst or outside the reactor. Effective catalyst reactivation is achieved whether the catalyst is completely deactivated or partially deactivated. A fluid reactivating agent is employed to dissolve catalyst fouling agents and also to react with such agents and carry away the reaction products. The deactivated catalyst is contacted with the fluid reactivating agent under pressure and temperature conditions such that the fluid reactivating agent is dense enough to effectively dissolve the fouling agents and any reaction products of the fouling agents and the reactivating agent. Useful pressures and temperatures for reactivation include near-critical, critical, and supercritical pressures and temperatures for the reactivating agent. The fluid reactivating agent can include, for example, a branched paraffin containing at least one tertiary carbon atom, or a compound that can be isomerized to a molecule containing at least one tertiary carbon atom.

  18. An antiviral disulfide compound blocks interaction between arenavirus Z protein and cellular promyelocytic leukemia protein

    SciTech Connect

    Garcia, C.C.; Topisirovic, I.; Djavani, M.; Borden, K.L.B.; Damonte, E.B.; Salvato, M.S.

    2010-03-19

    The promyelocytic leukemia protein (PML) forms nuclear bodies (NB) that can be redistributed by virus infection. In particular, lymphocytic choriomeningitis virus (LCMV) influences disruption of PML NB through the interaction of PML with the arenaviral Z protein. In a previous report, we have shown that the disulfide compound NSC20625 has antiviral and virucidal properties against arenaviruses, inducing unfolding and oligomerization of Z without affecting cellular RING-containing proteins such as the PML. Here, we further studied the effect of the zinc-finger-reactive disulfide NSC20625 on PML-Z interaction. In HepG2 cells infected with LCMV or transiently transfected with Z protein constructs, treatment with NSC20625 restored PML distribution from a diffuse-cytoplasmic pattern to punctate, discrete NB which appeared identical to NB found in control, uninfected cells. Similar results were obtained in cells transfected with a construct expressing a Z mutant in zinc-binding site 2 of the RING domain, confirming that this Z-PML interaction requires the integrity of only one zinc-binding site. Altogether, these results show that the compound NSC20625 suppressed Z-mediated PML NB disruption and may be used as a tool for designing novel antiviral strategies against arenavirus infection.

  19. Surface passivation process of compound semiconductor material using UV photosulfidation

    DOEpatents

    Ashby, Carol I. H.

    1995-01-01

    A method for passivating compound semiconductor surfaces by photolytically disrupting molecular sulfur vapor with ultraviolet radiation to form reactive sulfur which then reacts with and passivates the surface of compound semiconductors.

  20. GLOBAL INVENTORY OF VOLATILE COMPOUND EMISSIONS FROM ANTHROPOGENIC SOURCES

    EPA Science Inventory

    The report describes a global inventory anthropogenic volatile organic compound (VOC) emissions that includes a separate inventory for each of seven pollutant groups--paraffins, olefins, aromatics, formaldehyde, other aldehydes, other aromatics, and marginally reactive compounds....

  1. GLOBAL INVENTORY OF VOLATILE ORGANIC COMPOUND EMISSIONS FORM ANTHROPOGENIC SOURCES

    EPA Science Inventory

    The report describes a global inventory anthropogenic volatile organic compound (VOC) emissions that includes a separate inventory for each of seven pollutant groups--paraffins, olefins, aromatics, formaldehyde, other aldehydes, other aromatics, and marginally reactive compounds....

  2. Total OH reactivity emissions from Norway spruce

    NASA Astrophysics Data System (ADS)

    Nölscher, Anke; Bourtsoukidis, Efstratios; Bonn, Boris; Kesselmeier, Jürgen; Lelieveld, Jos; Williams, Jonathan

    2013-04-01

    Forest emissions represent a strong potential sink for the main tropospheric oxidant, the hydroxyl radical (OH). In forested environments, the comparison of the directly determined overall sink of OH radicals, the total OH reactivity, and the individually measured OH sink compounds often exposes a significant gap. This "missing" OH reactivity can be high and influenced by both direct biogenic emissions and secondary photo-oxidation products. To investigate the source of the missing OH sinks in forests, total OH reactivity emission rates were determined for the first time from a Norway spruce (Picea abies) throughout spring, summer and autumn 2011. The total OH reactivity was measured inside a branch enclosure using the Comparative Reactivity Method (CRM) with a Proton Transfer Reaction-Mass Spectrometer (PTR-MS) as the detector. In parallel, separate volatile organic compounds (VOC) emission rates were monitored by a second PTR-MS, including the signal of isoprene, acetaldehyde, total monoterpenes and total sesquiterpenes. The comparison of known and PTR-MS detected OH sink compounds and the directly measured total OH reactivity emitted from Norway spruce revealed unmeasured and possibly unknown primary biogenic emissions. These were found to be highest in late summer during daytime coincident with highest temperatures and ozone levels.

  3. Transfer of tactile perceptual learning to untrained neighboring fingers reflects natural use relationships

    PubMed Central

    Harrar, Vanessa; Oliver, Jonathan; Johansen-Berg, Heidi; Spence, Charles

    2015-01-01

    Tactile learning transfers from trained to untrained fingers in a pattern that reflects overlap between the representations of fingers in the somatosensory system (e.g., neurons with multifinger receptive fields). While physical proximity on the body is known to determine the topography of somatosensory representations, tactile coactivation is also an established organizing principle of somatosensory topography. In this study we investigated whether tactile coactivation, induced by habitual inter-finger cooperative use (use pattern), shapes inter-finger overlap. To this end, we used psychophysics to compare the transfer of tactile learning from the middle finger to its adjacent fingers. This allowed us to compare transfer to two fingers that are both physically and cortically adjacent to the middle finger but have differing use patterns. Specifically, the middle finger is used more frequently with the ring than with the index finger. We predicted this should lead to greater representational overlap between the former than the latter pair. Furthermore, this difference in overlap should be reflected in differential learning transfer from the middle to index vs. ring fingers. Subsequently, we predicted temporary learning-related changes in the middle finger's representation (e.g., cortical magnification) would cause transient interference in perceptual thresholds of the ring, but not the index, finger. Supporting this, longitudinal analysis revealed a divergence where learning transfer was fast to the index finger but relatively delayed to the ring finger. Our results support the theory that tactile coactivation patterns between digits affect their topographic relationships. Our findings emphasize how action shapes perception and somatosensory organization. PMID:26631145

  4. Transfer of tactile perceptual learning to untrained neighboring fingers reflects natural use relationships.

    PubMed

    Dempsey-Jones, Harriet; Harrar, Vanessa; Oliver, Jonathan; Johansen-Berg, Heidi; Spence, Charles; Makin, Tamar R

    2016-03-01

    Tactile learning transfers from trained to untrained fingers in a pattern that reflects overlap between the representations of fingers in the somatosensory system (e.g., neurons with multifinger receptive fields). While physical proximity on the body is known to determine the topography of somatosensory representations, tactile coactivation is also an established organizing principle of somatosensory topography. In this study we investigated whether tactile coactivation, induced by habitual inter-finger cooperative use (use pattern), shapes inter-finger overlap. To this end, we used psychophysics to compare the transfer of tactile learning from the middle finger to its adjacent fingers. This allowed us to compare transfer to two fingers that are both physically and cortically adjacent to the middle finger but have differing use patterns. Specifically, the middle finger is used more frequently with the ring than with the index finger. We predicted this should lead to greater representational overlap between the former than the latter pair. Furthermore, this difference in overlap should be reflected in differential learning transfer from the middle to index vs. ring fingers. Subsequently, we predicted temporary learning-related changes in the middle finger's representation (e.g., cortical magnification) would cause transient interference in perceptual thresholds of the ring, but not the index, finger. Supporting this, longitudinal analysis revealed a divergence where learning transfer was fast to the index finger but relatively delayed to the ring finger. Our results support the theory that tactile coactivation patterns between digits affect their topographic relationships. Our findings emphasize how action shapes perception and somatosensory organization. PMID:26631145

  5. Analysis and optimal design of an underactuated finger mechanism for LARM hand

    NASA Astrophysics Data System (ADS)

    Yao, Shuangji; Ceccarelli, Marco; Carbone, Giuseppe; Zhan, Qiang; Lu, Zhen

    2011-09-01

    This paper aims to present general design considerations and optimality criteria for underactuated mechanisms in finger designs. Design issues related to grasping task of robotic fingers are discussed. Performance characteristics are outlined as referring to several aspects of finger mechanisms. Optimality criteria of the finger performances are formulated after careful analysis. A general design algorithm is summarized and formulated as a suitable multi-objective optimization problem. A numerical case of an underactuated robot finger design for Laboratory of Robotics and Mechatronics (LARM) hand is illustrated with the aim to show the practical feasibility of the proposed concepts and computations.

  6. Finger-vein and fingerprint recognition based on a feature-level fusion method

    NASA Astrophysics Data System (ADS)

    Yang, Jinfeng; Hong, Bofeng

    2013-07-01

    Multimodal biometrics based on the finger identification is a hot topic in recent years. In this paper, a novel fingerprint-vein based biometric method is proposed to improve the reliability and accuracy of the finger recognition system. First, the second order steerable filters are used here to enhance and extract the minutiae features of the fingerprint (FP) and finger-vein (FV). Second, the texture features of fingerprint and finger-vein are extracted by a bank of Gabor filter. Third, a new triangle-region fusion method is proposed to integrate all the fingerprint and finger-vein features in feature-level. Thus, the fusion features contain both the finger texture-information and the minutiae triangular geometry structure. Finally, experimental results performed on the self-constructed finger-vein and fingerprint databases are shown that the proposed method is reliable and precise in personal identification.

  7. Development of a finger biomechanical model and its considerations.

    PubMed

    Fok, Kim Seng; Chou, Siaw Meng

    2010-03-01

    The development of a biomechanical model for a human finger is faced with many challenges, such as extensor mechanism complexity, statistical indeterminacy and suitability of computational processes. Motivation for this work was to develop a computer model that is able to predict the internal loading patterns of tendons and joint surfaces experienced by the human finger, while mitigating these challenges. Proposed methodology was based on a non-linear optimising mathematical technique with a criterion of boundary conditions and equality equations, maximised against unknown parameters to reduce statistical indeterminacy. Initial validation was performed via the simulation of one dynamic and two static postures case studies. Past models and experiments were used, based on published literature, to verify the proposed model's methodology and results. The feasibility of the proposed methodology was deemed satisfactory as the simulated results were concordant with in-vivo results for the extrinsic flexors. PMID:19962148

  8. Light-Inducible Gene Regulation with Engineered Zinc Finger Proteins

    PubMed Central

    Polstein, Lauren R.; Gersbach, Charles A.

    2014-01-01

    The coupling of light-inducible protein-protein interactions with gene regulation systems has enabled the control of gene expression with light. In particular, heterodimer protein pairs from plants can be used to engineer a gene regulation system in mammalian cells that is reversible, repeatable, tunable, controllable in a spatiotemporal manner, and targetable to any DNA sequence. This system, Light-Inducible Transcription using Engineered Zinc finger proteins (LITEZ), is based on the blue light-induced interaction of GIGANTEA and the LOV domain of FKF1 that drives the localization of a transcriptional activator to the DNA-binding site of a highly customizable engineered zinc finger protein. This chapter provides methods for modifying LITEZ to target new DNA sequences, engineering a programmable LED array to illuminate cell cultures, and using the modified LITEZ system to achieve spatiotemporal control of transgene expression in mammalian cells. PMID:24718797

  9. Automatic finger joint synovitis localization in ultrasound images

    NASA Astrophysics Data System (ADS)

    Nurzynska, Karolina; Smolka, Bogdan

    2016-04-01

    A long-lasting inflammation of joints results between others in many arthritis diseases. When not cured, it may influence other organs and general patients' health. Therefore, early detection and running proper medical treatment are of big value. The patients' organs are scanned with high frequency acoustic waves, which enable visualization of interior body structures through an ultrasound sonography (USG) image. However, the procedure is standardized, different projections result in a variety of possible data, which should be analyzed in short period of time by a physician, who is using medical atlases as a guidance. This work introduces an efficient framework based on statistical approach to the finger joint USG image, which enables automatic localization of skin and bone regions, which are then used for localization of the finger joint synovitis area. The processing pipeline realizes the task in real-time and proves high accuracy when compared to annotation prepared by the expert.

  10. Hamiltonian formulation towards minimization of viscous fluid fingering

    NASA Astrophysics Data System (ADS)

    Batista, Carlos; Dias, Eduardo O.; Miranda, José A.

    2016-07-01

    A variational approach has been recently employed to determine the ideal time-dependent injection rate Q (t ) that minimizes fingering formation when a fluid is injected in a Hele-Shaw cell filled with another fluid of much greater viscosity. However, such a calculation is approximate in nature, since it has been performed by assuming a high capillary number regime. In this work, we go one step further, and utilize a Hamiltonian formulation to obtain an analytical exact solution for Q (t ) , now valid for arbitrary values of the capillary number. Moreover, this Hamiltonian scheme is applied to calculate the corresponding injection rate that minimizes fingering formation in a uniform three-dimensional porous media. An analysis of the improvement offered by these exact injection rate expressions in comparison with previous approximate results is also provided.

  11. Hamiltonian formulation towards minimization of viscous fluid fingering.

    PubMed

    Batista, Carlos; Dias, Eduardo O; Miranda, José A

    2016-07-01

    A variational approach has been recently employed to determine the ideal time-dependent injection rate Q(t) that minimizes fingering formation when a fluid is injected in a Hele-Shaw cell filled with another fluid of much greater viscosity. However, such a calculation is approximate in nature, since it has been performed by assuming a high capillary number regime. In this work, we go one step further, and utilize a Hamiltonian formulation to obtain an analytical exact solution for Q(t), now valid for arbitrary values of the capillary number. Moreover, this Hamiltonian scheme is applied to calculate the corresponding injection rate that minimizes fingering formation in a uniform three-dimensional porous media. An analysis of the improvement offered by these exact injection rate expressions in comparison with previous approximate results is also provided. PMID:27575219

  12. Novel titanium-aluminum joints for cryogenic cold finger structures

    NASA Astrophysics Data System (ADS)

    Meehan, H. M.; Sweet, R. C.

    For optimum performance, the sensors employed in airborne detection and surveillance systems must be maintained at low temperatures. The containing wall of the expansion volume of a Stirling cycle cooler may provide the low temperature surface for mounting the sensors. IR detectors are commonly mounted on copper heat exchanger surfaces. A stainless steel member is employed to thermally isolate and structurally stabilize such surfaces. It is pointed out that the use of an aluminum-titanium cold finger results in a considerable weight reduction. The present investigation is concerned with an attempt to obtain such structures with the aid of a technique involving the casting of molten aluminum onto an appropriately dimensioned and positioned titanium member, taking into account the fact that aluminum readily wets and bonds to clean titanium surfaces. The casting is then machined to provide the form and structure desired. It is concluded that aluminum-titanium cast structures offer good potential for use as cryogenic cold finger assemblies.

  13. Emerging roles of zinc finger proteins in regulating adipogenesis

    PubMed Central

    Wei, Shengjuan; Zhang, Lifan; Zhou, Xiang; Du, Min; Jiang, Zhihua; Hausman, Gary J.; Bergen, Werner G.; Zan, Linsen; Dodson, Michael V.

    2014-01-01

    Proteins containing the zinc finger domain(s) are named zinc finger proteins (ZFPs), which are one of the largest classes of transcription factors in eukaryotic genomes. A large number of ZFPs have been studied and many of them were found to be involved regulating normal growth and development of cells and tissues through diverse signal transduction pathways. Recent studies revealed that a small but increasing number of ZFPs could function as key transcriptional regulators involved in adipogenesis. As the prevalence of obesity and metabolic disorders, the investigation of molecular regulatory mechanisms of adipocyte development must be more completely understood to develop novel and long term impact strategies for ameliorating obesity. In this review, we discuss recent work which has documented that ZFPs are important functional contributors to the regulation of adipogenesis. Taken altogether these data lead to the conclusion that ZFPs may become promising targets to combat human obesity. PMID:23760207

  14. Controlling and minimizing fingering instabilities in non-Newtonian fluids.

    PubMed

    Fontana, João V; Dias, Eduardo O; Miranda, José A

    2014-01-01

    The development of the viscous fingering instability in Hele-Shaw cells has great practical and scientific importance. Recently, researchers have proposed different strategies to control the number of interfacial fingering structures, or to minimize as much as possible the amplitude of interfacial disturbances. Most existing studies address the situation in which an inviscid fluid displaces a viscous Newtonian fluid. In this work, we report on controlling and minimizing protocols considering the situation in which the displaced fluid is a non-Newtonian, power-law fluid. The necessary changes on the controlling schemes due to the shear-thinning and shear thickening nature of the displaced fluid are calculated analytically and discussed. PMID:24580329

  15. New Optical Methods for Liveness Detection on Fingers

    PubMed Central

    Dolezel, Michal; Vana, Jan; Brezinova, Eva; Yim, Jaegeol; Shim, Kyubark

    2013-01-01

    This paper is devoted to new optical methods, which are supposed to be used for liveness detection on fingers. First we describe the basics about fake finger use in fingerprint recognition process and the possibilities of liveness detection. Then we continue with introducing three new liveness detection methods, which we developed and tested in the scope of our research activities—the first one is based on measurement of the pulse, the second one on variations of optical characteristics caused by pressure change, and the last one is based on reaction of skin to illumination with different wavelengths. The last part deals with the influence of skin diseases on fingerprint recognition, especially on liveness detection. PMID:24151584

  16. Finger tips detection for two handed gesture recognition

    NASA Astrophysics Data System (ADS)

    Bhuyan, M. K.; Kar, Mithun Kumar; Neog, Debanga Raj

    2011-10-01

    In this paper, a novel algorithm is proposed for fingertips detection in view of two-handed static hand pose recognition. In our method, finger tips of both hands are detected after detecting hand regions by skin color-based segmentation. At first, the face is removed in the image by using Haar classifier and subsequently, the regions corresponding to the gesturing hands are isolated by a region labeling technique. Next, the key geometric features characterizing gesturing hands are extracted for two hands. Finally, for all possible/allowable finger movements, a probabilistic model is developed for pose recognition. Proposed method can be employed in a variety of applications like sign language recognition and human-robot-interactions etc.

  17. [Congenital Fibrosarcoma of the Left Index Finger - An Unusual Case].

    PubMed

    Mailänder, L; Piza-Katzer, H

    2016-02-01

    Congenital fibrosarcoma is a rare mesenchymal soft tissue tumour, which most commonly develops in the peripheral extremities during infancy. Diagnostic work-up is a challenge for clinicians and pathologists alike, because in many cases the lesion initially resembles a haemangioma on macroscopic inspection. A 4-month-old boy presented with a strongly vascularised tumour of the left index finger, which had been diagnosed as a capillary haemangioma by means of a biopsy performed in another facility. The lesion had been treated with systemic and intralesional cortisone injections. Due to ulceration and the risk of infection, the tumour mass was resected with the index finger being preserved. The histological appearance was inconclusive. PCR revealed a congenital fibrosarcoma. 2 years after surgery, the boy is free from recurrence. PMID:26895521

  18. When pliers become fingers in the monkey motor system

    PubMed Central

    Umiltà, M. A.; Escola, L.; Intskirveli, I.; Grammont, F.; Rochat, M.; Caruana, F.; Jezzini, A.; Gallese, V.; Rizzolatti, G.

    2008-01-01

    The capacity to use tools is a fundamental evolutionary achievement. Its essence stands in the capacity to transfer a proximal goal (grasp a tool) to a distal goal (e.g., grasp food). Where and how does this goal transfer occur? Here, we show that, in monkeys trained to use tools, cortical motor neurons, active during hand grasping, also become active during grasping with pliers, as if the pliers were now the hand fingers. This motor embodiment occurs both for normal pliers and for “reverse pliers,” an implement that requires finger opening, instead of their closing, to grasp an object. We conclude that the capacity to use tools is based on an inherently goal-centered functional organization of primate cortical motor areas. PMID:18238904

  19. Computer-based automatic finger- and speech-tracking system.

    PubMed

    Breidegard, Björn

    2007-11-01

    This article presents the first technology ever for online registration and interactive and automatic analysis of finger movements during tactile reading (Braille and tactile pictures). Interactive software has been developed for registration (with two cameras and a microphone), MPEG-2 video compression and storage on disk or DVD as well as an interactive analysis program to aid human analysis. An automatic finger-tracking system has been implemented which also semiautomatically tracks the reading aloud speech on the syllable level. This set of tools opens the way for large scale studies of blind people reading Braille or tactile images. It has been tested in a pilot project involving congenitally blind subjects reading texts and pictures. PMID:18183897

  20. Compound matrices

    NASA Astrophysics Data System (ADS)

    Kravvaritis, Christos; Mitrouli, Marilena

    2009-02-01

    This paper studies the possibility to calculate efficiently compounds of real matrices which have a special form or structure. The usefulness of such an effort lies in the fact that the computation of compound matrices, which is generally noneffective due to its high complexity, is encountered in several applications. A new approach for computing the Singular Value Decompositions (SVD's) of the compounds of a matrix is proposed by establishing the equality (up to a permutation) between the compounds of the SVD of a matrix and the SVD's of the compounds of the matrix. The superiority of the new idea over the standard method is demonstrated. Similar approaches with some limitations can be adopted for other matrix factorizations, too. Furthermore, formulas for the n - 1 compounds of Hadamard matrices are derived, which dodge the strenuous computations of the respective numerous large determinants. Finally, a combinatorial counting technique for finding the compounds of diagonal matrices is illustrated.

  1. Connective tissue adaptations in the fingers of performance sport climbers.

    PubMed

    Schreiber, Tonja; Allenspach, Philippe; Seifert, Burkhardt; Schweizer, Andreas

    2015-01-01

    This study investigates the changes of the connective tissue in the fingers of performance sport climbers resulting after a minimum of 15 years of climbing. Evaluation was performed by ultrasonography on the palmar side of the fingers (Dig) II-V to measure the thickness of the A2 and A4 annular pulleys, the flexor digitorum superficialis (FDS) and profundus (FDP) tendons and the palmar plates (PP's) of the proximal interphalangeal (PIP) as well as distal interphalangeal (DIP) joint in sagittal and axial direction. Totally, 31 experienced male sport climbers (mean age 37y, 30-48y grade French scale median 8b, range 7b+ to 9a+) participated in the study. The control-group consisted of 20 male non-climbers (age 37y, 30-51y). The A2 and A4 pulleys in climbers were all significantly thicker (A2 Dig III 62%, Dig IV 69%; A4 Dig III 69%, Dig IV 76%) as compared to non-climbers pulleys. All PP's of the DIP joints were also significantly thicker, particularly at Dig III and IV (76 and 67%), whereas the PP's at PIP joints were only scarce significant for three joints. Differences of the diameter of the flexor tendons were less distinct (1-21%) being significant only over the middle phalanx. High load to the fingers of rock climbers after a minimum of 15 years of climbing years induced considerable connective tissue adaptions in the fingers, most distinct at the flexor tendon pulleys and joint capsule (PP) of the DIP joints and well detectable by ultrasound. PMID:26267120

  2. Mechanism of Hot Finger Formation in Mantle Wedge

    NASA Astrophysics Data System (ADS)

    Matsuo, M. Y.; Tamura, Y.; Sakaguchi, H.

    2013-12-01

    Processes of mantle melting and volcanic eruptions along subduction zones are often illustrated by the use of two-dimensional cross-section models of convergent margins. However, Quaternary volcanoes in the NE Japan arc could be grouped into ten volcano clusters striking transverse to the arc; these have an average width of ~ 50 km, and are separated by parallel gaps 30-75 km wide (Tamura et al., 2002). Moreover, the structure of the mantle wedge and arc crust beneath the NE Japan arc and the Izu-Bonin-Mariana arc, respectively, suggest that the third dimension, lying along the strike of the arc, is necessary to understand the actual production of magmas in subduction zones (e.g., Nakajima et al., 2001; Hasegawa & Nakajima, 2004; Kodaira et al., 2007; Kodaira et al., 2008). Common periodic structural variations, having wavelengths of 80-100 km, can be observed in both areas. This grouping of volcanoes and the structural variations may be related to locally developed hot regions within the mantle wedge that have the form of inclined, 50 km-wide fingers (hot fingers). The 'hot fingers' models (Tamura et al., 2002) may play an important role in linking the 3D structures within the mantle wedge and overlying arc crust to volcanic eruptions at the surface. To explore a physical and mathematical mechanism to produce a hot finger pattern, we develop a hydrodynamic model of mantle convection in mantle wedge. A hypothesis incorporated in our model is a double diffusive mechanism of mantle materials; diffusion of composition of mantle materials is much weaker than temperature diffusion. We show that our model shows a spatiotemporal pattern in a mantle material composition, temperature, and velocity that are similar to the spatiotemporal patterns observed in the NE Japan arc.

  3. The EpiPen and the ischaemic finger.

    PubMed

    Singh, Talvinder; Randhawa, Susheelwant; Khanna, Rakesh

    2007-08-01

    We present a case of a 24-year-old with a history of accidental injection of adrenaline from an EpiPen into the proximal aspect of her left index finger. Various methods were advocated to treat digital ischaemia but were of no benefit. Topical infiltration of phentolamine in 1 ml of lignocaine 2% was given at the puncture site with immediate results of resolution of digital ischaemia. PMID:17620915

  4. Fingering in a driven hele-shaw cell

    PubMed

    Rauseo

    2000-12-01

    A modified Hele-Shaw cell in which the plate gap can be modulated in time was constructed. Highly nonlinear fingers on the interface between air and water in the cell were observed as the plate gap was driven at a variety of frequencies, but typically near 60 Hz. Modified equations to describe the flow in a periodically driven cell were derived and the linear stability analysis of waves on a circular fluid-fluid interface was performed. PMID:11138089

  5. Numerical simulation of immiscible viscous fingering using adaptive unstructured meshes

    NASA Astrophysics Data System (ADS)

    Adam, A.; Salinas, P.; Percival, J. R.; Pavlidis, D.; Pain, C.; Muggeridge, A. H.; Jackson, M.

    2015-12-01

    Displacement of one fluid by another in porous media occurs in various settings including hydrocarbon recovery, CO2 storage and water purification. When the invading fluid is of lower viscosity than the resident fluid, the displacement front is subject to a Saffman-Taylor instability and is unstable to transverse perturbations. These instabilities can grow, leading to fingering of the invading fluid. Numerical simulation of viscous fingering is challenging. The physics is controlled by a complex interplay of viscous and diffusive forces and it is necessary to ensure physical diffusion dominates numerical diffusion to obtain converged solutions. This typically requires the use of high mesh resolution and high order numerical methods. This is computationally expensive. We demonstrate here the use of a novel control volume - finite element (CVFE) method along with dynamic unstructured mesh adaptivity to simulate viscous fingering with higher accuracy and lower computational cost than conventional methods. Our CVFE method employs a discontinuous representation for both pressure and velocity, allowing the use of smaller control volumes (CVs). This yields higher resolution of the saturation field which is represented CV-wise. Moreover, dynamic mesh adaptivity allows high mesh resolution to be employed where it is required to resolve the fingers and lower resolution elsewhere. We use our results to re-examine the existing criteria that have been proposed to govern the onset of instability.Mesh adaptivity requires the mapping of data from one mesh to another. Conventional methods such as consistent interpolation do not readily generalise to discontinuous fields and are non-conservative. We further contribute a general framework for interpolation of CV fields by Galerkin projection. The method is conservative, higher order and yields improved results, particularly with higher order or discontinuous elements where existing approaches are often excessively diffusive.

  6. Finger pad friction and its role in grip and touch

    PubMed Central

    Adams, Michael J.; Johnson, Simon A.; Lefèvre, Philippe; Lévesque, Vincent; Hayward, Vincent; André, Thibaut; Thonnard, Jean-Louis

    2013-01-01

    Many aspects of both grip function and tactile perception depend on complex frictional interactions occurring in the contact zone of the finger pad, which is the subject of the current review. While it is well established that friction plays a crucial role in grip function, its exact contribution for discriminatory touch involving the sliding of a finger pad is more elusive. For texture discrimination, it is clear that vibrotaction plays an important role in the discriminatory mechanisms. Among other factors, friction impacts the nature of the vibrations generated by the relative movement of the fingertip skin against a probed object. Friction also has a major influence on the perceived tactile pleasantness of a surface. The contact mechanics of a finger pad is governed by the fingerprint ridges and the sweat that is exuded from pores located on these ridges. Counterintuitively, the coefficient of friction can increase by an order of magnitude in a period of tens of seconds when in contact with an impermeably smooth surface, such as glass. In contrast, the value will decrease for a porous surface, such as paper. The increase in friction is attributed to an occlusion mechanism and can be described by first-order kinetics. Surprisingly, the sensitivity of the coefficient of friction to the normal load and sliding velocity is comparatively of second order, yet these dependencies provide the main basis of theoretical models which, to-date, largely ignore the time evolution of the frictional dynamics. One well-known effect on taction is the possibility of inducing stick–slip if the friction decreases with increasing sliding velocity. Moreover, the initial slip of a finger pad occurs by the propagation of an annulus of failure from the perimeter of the contact zone and this phenomenon could be important in tactile perception and grip function. PMID:23256185

  7. Which Fingers Should We Perform Two-Finger Chest Compression Technique with When Performing Cardiopulmonary Resuscitation on an Infant in Cardiac Arrest?

    PubMed

    Kim, Young Sinn; Oh, Je Hyeok; Kim, Chan Woong; Kim, Sung Eun; Lee, Dong Hoon; Hong, Jun Young

    2016-06-01

    This study compared the effectiveness two-finger chest compression technique (TFCC) performed using the right vs. left hand and the index-middle vs. middle-ring fingers. Four different finger/hand combinations were tested randomly in 30 healthcare providers performing TFCC (Test 1: the right index-middle fingers; Test 2: the left index-middle fingers; Test 3: the right middle-ring fingers; Test 4: the left middle-ring fingers) using two cross-over trials. The "patient" was a 3-month-old-infant-sized manikin. Each experiment consisted of cardiopulmonary resuscitation (CPR) consisting of 2 minutes of 30:2 compression: ventilation performed by one rescuer on a manikin lying on the floor as if in cardiac arrest. Ventilations were performed using the mouth-to-mouth method. Compression and ventilation data were collected during the tests. The mean compression depth (MCD) was significantly greater in TFCC performed with the index-middle fingers than with the middle-ring fingers regardless of the hand (95% confidence intervals; right hand: 37.8-40.2 vs. 35.2-38.6 mm, P = 0.002; left hand: 36.9-39.2 vs. 35.5-38.1 mm, P = 0.003). A deeper MCD was achieved with the index-middle fingers of the right versus the left hand (P = 0.004). The ratio of sufficiently deep compressions showed the same patterns. There were no significant differences in the other data. The best performance of TFCC in simulated 30:2 compression: ventilation CPR performed by one rescuer on an infant in cardiac arrest lying on the floor was obtained using the index-middle fingers of the right hand. Clinical Trial Registry at the Clinical Research Information Service (KCT0001515). PMID:27247512

  8. Which Fingers Should We Perform Two-Finger Chest Compression Technique with When Performing Cardiopulmonary Resuscitation on an Infant in Cardiac Arrest?

    PubMed Central

    2016-01-01

    This study compared the effectiveness two-finger chest compression technique (TFCC) performed using the right vs. left hand and the index-middle vs. middle-ring fingers. Four different finger/hand combinations were tested randomly in 30 healthcare providers performing TFCC (Test 1: the right index-middle fingers; Test 2: the left index-middle fingers; Test 3: the right middle-ring fingers; Test 4: the left middle-ring fingers) using two cross-over trials. The “patient” was a 3-month-old-infant-sized manikin. Each experiment consisted of cardiopulmonary resuscitation (CPR) consisting of 2 minutes of 30:2 compression: ventilation performed by one rescuer on a manikin lying on the floor as if in cardiac arrest. Ventilations were performed using the mouth-to-mouth method. Compression and ventilation data were collected during the tests. The mean compression depth (MCD) was significantly greater in TFCC performed with the index-middle fingers than with the middle-ring fingers regardless of the hand (95% confidence intervals; right hand: 37.8–40.2 vs. 35.2–38.6 mm, P = 0.002; left hand: 36.9–39.2 vs. 35.5–38.1 mm, P = 0.003). A deeper MCD was achieved with the index-middle fingers of the right versus the left hand (P = 0.004). The ratio of sufficiently deep compressions showed the same patterns. There were no significant differences in the other data. The best performance of TFCC in simulated 30:2 compression: ventilation CPR performed by one rescuer on an infant in cardiac arrest lying on the floor was obtained using the index-middle fingers of the right hand. Clinical Trial Registry at the Clinical Research Information Service (KCT0001515). PMID:27247512

  9. Finger vein recognition based on the hyperinformation feature

    NASA Astrophysics Data System (ADS)

    Xi, Xiaoming; Yang, Gongping; Yin, Yilong; Yang, Lu

    2014-01-01

    The finger vein is a promising biometric pattern for personal identification due to its advantages over other existing biometrics. In finger vein recognition, feature extraction is a critical step, and many feature extraction methods have been proposed to extract the gray, texture, or shape of the finger vein. We treat them as low-level features and present a high-level feature extraction framework. Under this framework, base attribute is first defined to represent the characteristics of a certain subcategory of a subject. Then, for an image, the correlation coefficient is used for constructing the high-level feature, which reflects the correlation between this image and all base attributes. Since the high-level feature can reveal characteristics of more subcategories and contain more discriminative information, we call it hyperinformation feature (HIF). Compared with low-level features, which only represent the characteristics of one subcategory, HIF is more powerful and robust. In order to demonstrate the potential of the proposed framework, we provide a case study to extract HIF. We conduct comprehensive experiments to show the generality of the proposed framework and the efficiency of HIF on our databases, respectively. Experimental results show that HIF significantly outperforms the low-level features.

  10. Two-Finger EKG Method of Detecting Evasive Responses

    NASA Technical Reports Server (NTRS)

    Oldham, Daniel

    2004-01-01

    A system based on acquisition and processing of electrocardiographic (EKG) signals from two fingers has been proposed as a means of determining whether a person is answering questions evasively. The system -- in effect, a "lie detector" of sorts, would be used to gauge prospective passengers responses to questions at airport security checkpoints. The person to be interrogated would be required to put one finger from each hand onto two metal strips on a counter and would be instructed to relax and wait for the system to indicate that it is ready. Then a security person would ask the passenger a set of standard security questions. EKG signals acquired through contact with the fingers would be processed by an algorithm that would extract a single-value measure of the level of stress in the interrogated person. This measure would be used to determine whether the system should display a green or a red light to signify that the person is or is not, respectively, telling the truth. It has also been conjectured that the system may be useful for communicating with a person who is in a coma and, hence, unable to speak.

  11. Numerical simulation of double-diffusive finger convection

    USGS Publications Warehouse

    Hughes, J.D.; Sanford, W.E.; Vacher, H.L.

    2005-01-01

    A hybrid finite element, integrated finite difference numerical model is developed for the simulation of double-diffusive and multicomponent flow in two and three dimensions. The model is based on a multidimensional, density-dependent, saturated-unsaturated transport model (SUTRA), which uses one governing equation for fluid flow and another for solute transport. The solute-transport equation is applied sequentially to each simulated species. Density coupling of the flow and solute-transport equations is accounted for and handled using a sequential implicit Picard iterative scheme. High-resolution data from a double-diffusive Hele-Shaw experiment, initially in a density-stable configuration, is used to verify the numerical model. The temporal and spatial evolution of simulated double-diffusive convection is in good agreement with experimental results. Numerical results are very sensitive to discretization and correspond closest to experimental results when element sizes adequately define the spatial resolution of observed fingering. Numerical results also indicate that differences in the molecular diffusivity of sodium chloride and the dye used to visualize experimental sodium chloride concentrations are significant and cause inaccurate mapping of sodium chloride concentrations by the dye, especially at late times. As a result of reduced diffusion, simulated dye fingers are better defined than simulated sodium chloride fingers and exhibit more vertical mass transfer. Copyright 2005 by the American Geophysical Union.

  12. The Impact of Miscible Viscous Fingering on Mixing

    NASA Astrophysics Data System (ADS)

    Chui, J.; De Anna, P.; Juanes, R.

    2013-12-01

    Viscous fingering is a hydrodynamic instability that occurs when a less viscous fluid displaces a more viscous one. Instead of progressing as a uniform front, the less viscous fluid forms fingers that vary in size and shape to create complex patterns. The interface created from these patterns affects mixing between the two fluids, and therefore is of critical importance in applications such as enhanced oil recovery and microfluidics. This work focuses on how the evolution of the fingering interface affects mixing between two miscible fluids, specifically in a radial configuration. We measure the local concentration field temporally and spatially with the use of a fluorescent tracer in the injected fluid, and with this high resolution information are able to calculate various measures of mixing, such as mixing efficiency, scalar dissipation rate, and the areal mixing zone for different fluid injection rates and various viscosity ratios. We propose a scaling theory based on experimental observations for the growth of the mixing zone and the overall rate of mixing. This is a snapshot of the concentration field. In this experiment, water with a fluorescent tracer at a concentration of 250mg/L is displacing fluid ten times more viscous from a point injection. The inset shows an enlarged section of the concentration field.

  13. The Impact of Miscible Viscous Fingering on Mixing

    NASA Astrophysics Data System (ADS)

    Chui, Jane; de Anna, Pietro; Juanes, Ruben

    2013-11-01

    Viscous fingering is a hydrodynamic instability that occurs when a less viscous fluid displaces a more viscous one. Instead of progressing as a uniform front, the less viscous fluid forms fingers that vary in size and shape to create complex patterns. The interface created from these patterns affects mixing between the two fluids, and therefore is of critical importance in applications such as enhanced oil recovery and microfluidics. This work focuses on how the evolution of the fingering interface affects mixing between two miscible fluids, specifically in a radial configuration. We measure the local concentration field temporally and spatially with the use of a fluorescent tracer in the injected fluid, and with this high resolution information are able to calculate various measures of mixing, such as mixing efficiency, scalar dissipation rate, and the areal mixing zone for different fluid injection rates and various viscosity ratios. We propose a scaling theory based on experimental observations for the growth of the mixing zone and the overall rate of mixing.

  14. Coordination between breathing and mental grouping of pianistic finger movements.

    PubMed

    Ebert, Dietrich; Hefter, Harald; Binkofski, Ferdinand; Freund, Hans-Joachim

    2002-10-01

    6 pianists (age 22 to 43 years) performed a simple finger exercise at a spontaneously chosen most comfortable tempo on a Yamaha-Disklavier piano. Five versions of the exercise, notated in quarter notes, were presented with different types of meters: (1) 3/4, (2) 4/4, (3) 5/4, (4) 6/4, and (5) 7/4. The onsets of finger strokes were measured while respiration was recorded in parallel by means of a thermistor placed at the front of the dominant nostril. The chosen tempo (finger-beat-rate) was about 3 Hz on all trials but not exactly constant. Correspondingly, the meter-rate chosen was faster for 3/4 and 4/4 meter (around 1 Hz), slower for 5/4, 6/4, and 7/4 meter (around 0.5 Hz). Mean breathing rate while playing the piano (0.38 Hz) was significantly higher than while resting (0.22 Hz, p<.05). Pooling the data of all subjects, the ratios of instantaneous meter and breathing rates clustered around different integer values, depending on the type of meter. Also the individual data indicated integer ratios between instantaneous meter and breathing rates. Even periods of constant phase relations between onsets of the meter and of inspiration could be observed. Thus, the mental process of grouping the same piece of music by various musical meters interacts with unconscious breathing rhythm. PMID:12434824

  15. Compilation and evaluation of gas phase diffusion coefficients of reactive trace gases in the atmosphere: Volume 2. Diffusivities of organic compounds, pressure-normalised mean free paths, and average Knudsen numbers for gas uptake calculations

    NASA Astrophysics Data System (ADS)

    Tang, M. J.; Shiraiwa, M.; Poschl, U.; Cox, R. A.; Kalberer, M.

    2015-05-01

    Diffusion of organic vapours to the surface of aerosol or cloud particles is an important step for the formation and transformation of atmospheric particles. So far, however, a database of gas phase diffusion coefficients for organic compounds of atmospheric interest has not been available. In this work we have compiled and evaluated gas phase diffusivities (pressure-independent diffusion coefficients) of organic compounds reported by previous experimental studies, and we compare the measurement data to estimates obtained with Fuller's semi-empirical method. The difference between measured and estimated diffusivities are mostly < 10%. With regard to gas-particle interactions, different gas molecules, including both organic and inorganic compounds, exhibit similar Knudsen numbers (Kn) although their gas phase diffusivities may vary over a wide range. This is because different trace gas molecules have similar mean free paths in air at a given pressure. Thus, we introduce the pressure-normalised mean free path, λP ~ 100 nm atm, as a near-constant generic parameter that can be used for approximate calculation of Knudsen numbers as a simple function of gas pressure and particle diameter to characterise the influence of gas phase diffusion on the uptake of gases by aerosol or cloud particles. We use a kinetic multilayer model of gas-particle interaction to illustrate the effects of gas phase diffusion on the condensation of organic compounds with different volatilities. The results show that gas phase diffusion can play a major role in determining the growth of secondary organic aerosol particles by condensation of low-volatility organic vapours.

  16. New syntheses of diazo compounds.

    PubMed

    Maas, Gerhard

    2009-01-01

    Diazo compounds (R1R2C=N2) are known as versatile and useful substrates for an array of chemical transformations and, therefore, diazo chemistry is still far from losing anything of its long-standing fascination. In addition to many studies on the subsequent chemistry of the diazo group, the inventory of methods for the preparation of diazo compounds is continuously supplemented by new methods and novel variations of established procedures. Several of these synthetic approaches take into account the lability and remarkable chemical reactivity of certain classes of diazo compounds, and environmentally more benign procedures also continue to be developed. PMID:19790217

  17. Numerical Simulation of Flow, Pressure and Motion of Front Back Fingers in a Two Rows Finger Seal

    NASA Technical Reports Server (NTRS)

    Braun, M. Jack; Kudriavtsev, V. V.; Choy, Fred K.; Proctor, Margaret P.; Steinetz, Bruce M.

    2002-01-01

    This proposal fits within the programmatic long-term development direction for turbine engine seals of the Seal Team of the Mechanical Component Branch. The intended work concerns the further development of the Finger Seal concept which is a compliant passive-adaptive seal meant to mitigate (and eventually replace) the shortcomings of the entire class of rigid seals used today (labyrinth, honeycomb, mechanical face seals) in the gas turbines and compressors,

  18. Numerical Simulation of Flow, Pressure and Motion of Front Back Fingers in a Two Rows Finger Seal

    NASA Astrophysics Data System (ADS)

    Braun, M. Jack; Kudriavtsev, V. V.; Choy, Fred K.; Proctor, Margaret P.; Steinetz, Bruce M.

    2002-10-01

    This proposal fits within the programmatic long-term development direction for turbine engine seals of the Seal Team of the Mechanical Component Branch. The intended work concerns the further development of the Finger Seal concept which is a compliant passive-adaptive seal meant to mitigate (and eventually replace) the shortcomings of the entire class of rigid seals used today (labyrinth, honeycomb, mechanical face seals) in the gas turbines and compressors,

  19. Flexible Arm Splints in the Control of a Lesch-Nyhan Victim's Finger Biting and a Profoundly Retarded Client's Finger Sucking.

    ERIC Educational Resources Information Center

    Ball, Thomas S.; And Others

    1985-01-01

    Flexible arm splints permitting the control of hand-to-mouth contacts without restricting range of motion effectively suppressed the self-injurious finger biting of a child with Lesch-Nyhan disease and a profoundly retarded adult's stereotypic finger sucking. They offered an easily applied and much less restrictive alternative to soft-tie and…

  20. Polymers containing borane or carborane cage compounds and related applications

    DOEpatents

    Bowen, III, Daniel E; Eastwood, Eric A

    2013-04-23

    Polymers comprising residues of cage compound monomers having at least one polyalkoxy silyl substituent are provided. The cage compound monomers are selected from borane cage compound monomers comprising at least 7 cage atoms and/or carborane cage compound monomers comprising 7 to 11 cage compound monomers. Such polymers can further comprise one or more reactive matrices and/or co-monomers covalently bound with the cage compound monomer residues. Articles of manufacture comprising such polymers are also disclosed.

  1. Finger Counting and (2D:4D) Digit Ratio in Spatial-Numerical Association.

    PubMed

    Fabbri, Marco; Natale, Vincenzo

    2016-01-01

    It is reported that a canonical and cultural finger counting habit influences the spatial-numerical association. The digit ratio (the ratio between the lengths of the index and ring fingers as a putative indicator of prenatal androgen exposure) also plays an effect on space-number representation, reflecting a stronger left-to-right number representation in people with a short index finger and longer ring finger (i.e., 2D:4D ratio). It is unknown whether the finger counting habit and digit ratio have an effect on spatial-numerical association independently from each other or whether they interact with each other. In Study 1, the digit ratio and finger counting mapping were recorded in right handers. The participants performed number-to-position, digit string bisection, and physical line bisection tasks. In the number-to-position task, a finger counting effect was found, as well as a significant interaction between factors. A digit ratio effect was observed in the digit string bisection task. In Study 2, digit ratio and finger counting mapping were recorded in right and left handers. The results showed that the finger counting habit influenced the spatial biases in both numerical tasks. A significant interaction between finger counting and digit ratio was found in both numerical tasks when only the left hand was considered. The results are discussed considering the embodied nature of the spatial-numerical association. PMID:26562848

  2. Transcriptional cofactors of the FOG family interact with GATA proteins by means of multiple zinc fingers.

    PubMed Central

    Fox, A H; Liew, C; Holmes, M; Kowalski, K; Mackay, J; Crossley, M

    1999-01-01

    Friend of GATA-1 (FOG-1) is a zinc finger protein that has been shown to interact physically with the erythroid DNA-binding protein GATA-1 and modulate its transcriptional activity. Recently, two new members of the FOG family have been identified: a mammalian protein, FOG-2, that also associates with GATA-1 and other mammalian GATA factors; and U-shaped, a Drosophila protein that interacts with the Drosophila GATA protein Pannier. FOG proteins contain multiple zinc fingers and it has been shown previously that the sixth finger of FOG-1 interacts specifically with the N-finger but not the C-finger of GATA-1. Here we show that fingers 1, 5 and 9 of FOG-1 also interact with the N-finger of GATA-1 and that FOG-2 and U-shaped also contain multiple GATA-interacting fingers. We define the key contact residues and show that these residues are highly conserved in GATA-interacting fingers. We examine the effect of selectively mutating the four interacting fingers of FOG-1 and show that each contributes to FOG-1's ability to modulate GATA-1 activity. Finally, we show that FOG-1 can repress GATA-1-mediated activation and present evidence that this ability involves the recently described CtBP co-repressor proteins that recognize all known FOG proteins. PMID:10329627

  3. The effect of conservative management in extensor plus finger after partial amputation to the ulnar digits--a case report.

    PubMed

    Sudhakar, Gangatharam; Le blanc, Monique

    2012-03-01

    The extensor plus finger after partial amputation of ulnar digits can affect the functions of the hand. The therapist intricate knowledge of intrinsic and extrinsic mechanism of fingers and creative approach in therapy would solve the puzzle when managing complex problem (extensor plus finger). Here we study a case of extensor plus finger after partial amputation of ulnar digits, its mechanism, and our experience with conservative management in managing extensor plus finger. PMID:22411113

  4. System for reactivating catalysts

    SciTech Connect

    Ginosar, Daniel M.; Thompson, David N.; Anderson, Raymond P.

    2010-03-02

    A method of reactivating a catalyst, such as a solid catalyst or a liquid catalyst is provided. The method comprises providing a catalyst that is at least partially deactivated by fouling agents. The catalyst is contacted with a fluid reactivating agent that is at or above a critical point of the fluid reactivating agent and is of sufficient density to dissolve impurities. The fluid reactivating agent reacts with at least one fouling agent, releasing the at least one fouling agent from the catalyst. The at least one fouling agent becomes dissolved in the fluid reactivating agent and is subsequently separated or removed from the fluid reactivating agent so that the fluid reactivating agent may be reused. A system for reactivating a catalyst is also disclosed.

  5. Reactive-infiltration instability in radial geometry

    NASA Astrophysics Data System (ADS)

    Grodzki, Piotr; Szymczak, Piotr

    2015-04-01

    the instability growth rate depends on the Peclet number (Pe) and permeability contrast between the undissolved and dissolved phase (Γ) and find the region in the (Pe,Γ) space when the system is absolutely stable. This behaviour is in contrast to the viscous fingering problem in radial geometry [2], where for a given flow rate the front always becomes eventually unstable, after reaching a certain critical radius R. [1] J. Chadam, D. Ho , E. Merino, P. Ortoleva, A. Sen, Reactive In ltration Instabilities, IMA J. Appl. Math. 36, 207-221 (1986) [2] L. Paterson, Radial fingering in a Hele Shaw cell, J. Fluid Mech. 113, 513-529 (1981)

  6. Safe Disposal of Highly Reactive Chemicals.

    ERIC Educational Resources Information Center

    Lunn, George; Sansone, Eric B.

    1994-01-01

    Provides specific procedures for the disposal of a variety of highly reactive chemicals and reports the results of a study of their safe disposal. Disposal of some problematic sulfur-containing compounds are included. Procedures are based on a combination of literature review and author development. (LZ)

  7. Snail-type zinc finger proteins prevent neurogenesis in Scutoid and transgenic animals of Drosophila.

    PubMed

    Fuse, N; Matakatsu, H; Taniguchi, M; Hayashi, S

    1999-10-01

    Scutoid is a classical dominant gain-of-function mutation of Drosophila, causing a loss of bristles and roughening of the compound eye. Previous genetic and molecular analyses have shown that Scutoid is associated with a chromosomal transposition resulting in a fusion of no-oceli and snail genes. How this gene fusion event leads to the defects in neurogenesis was not known until now. Here have found that snail is ectopically expressed in the eye-antennal and wing imaginal discs in Scutoid larvae, and that this expression is reduced in Scutoid revertants. We have also shown that the expressivity of Scutoid is enhanced by zeste mutations. snail and escargot encode evolutionarily conserved zinc-finger proteins involved in the development of mesoderm and limbs. Snail and Escargot proteins share a common target DNA sequence with the basic helix-loop-helix (bHLH) type proneural gene products. When expressed in the developing external sense organ precursors of the thorax and the eye, these proteins cause a loss of mechanosensory bristles in the thorax and perturbed the development of the compound eye. Such phenotypes resemble those associated with Scutoid. Furthermore, the effect of ectopic Escargot on bristle development is antagonized by coexpression of the bHLH gene asense. Thus, our results suggest that the Scutoid phenotype is due to an ectopic snail expression under the control of no-oceli enhancer, antagonizing neurogenesis through its inhibitory interaction with bHLH proteins. PMID:10552298

  8. Fracture Reactivation in Chemically Reactive Rock Systems

    NASA Astrophysics Data System (ADS)

    Eichhubl, P.; Hooker, J. N.

    2013-12-01

    Reactivation of existing fractures is a fundamental process of brittle failure that controls the nucleation of earthquake ruptures, propagation and linkage of hydraulic fractures in oil and gas production, and the evolution of fault and fracture networks and thus of fluid and heat transport in the upper crust. At depths below 2-3 km, and frequently shallower, brittle processes of fracture growth, linkage, and reactivation compete with chemical processes of fracture sealing by mineral precipitation, with precipitation rates similar to fracture opening rates. We recently found rates of fracture opening in tectonically quiescent settings of 10-20 μm/m.y., rates similar to euhedral quartz precipitation under these conditions. The tendency of existing partially or completely cemented fractures to reactivate will vary depending on strain rate, mineral precipitation kinetics, strength contrast between host rock and fracture cement, stress conditions, degree of fracture infill, and fracture network geometry. Natural fractures in quartzite of the Cambrian Eriboll Formation, NW Scotland, exhibit a complex history of fracture formation and reactivation, with reactivation involving both repeated crack-seal opening-mode failure and shear failure of fractures that formed in opening mode. Fractures are partially to completely sealed with crack-seal or euhedral quartz cement or quartz cement fragmented by shear reactivation. Degree of cementation controls the tendency of fractures for later shear reactivation, to interact elastically with adjacent open fractures, and their intersection behavior. Using kinematic, dynamic, and diagenetic criteria, we determine the sequence of opening-mode fracture formation and later shear reactivation. We find that sheared fracture systems of similar orientation display spatially varying sense of slip We attribute these inconsistent directions of shear reactivation to 1) a heterogeneous stress field in this highly fractured rock unit and 2

  9. Reactive Intermediates in Cytochrome P450 Catalysis*

    PubMed Central

    Krest, Courtney M.; Onderko, Elizabeth L.; Yosca, Timothy H.; Calixto, Julio C.; Karp, Richard F.; Livada, Jovan; Rittle, Jonathan; Green, Michael T.

    2013-01-01

    Recently, we reported the spectroscopic and kinetic characterizations of cytochrome P450 compound I in CYP119A1, effectively closing the catalytic cycle of cytochrome P450-mediated hydroxylations. In this minireview, we focus on the developments that made this breakthrough possible. We examine the importance of enzyme purification in the quest for reactive intermediates and report the preparation of compound I in a second P450 (P450ST). In an effort to bring clarity to the field, we also examine the validity of controversial reports claiming the production of P450 compound I through the use of peroxynitrite and laser flash photolysis. PMID:23632017

  10. OH reactivity measurements within a boreal forest: evidence for unknown reactive emissions.

    PubMed

    Sinha, Vinayak; Williams, J; Lelieveld, J; Ruuskanen, T M; Kajos, M K; Patokoski, J; Hellen, H; Hakola, H; Mogensen, D; Boy, M; Rinne, J; Kulmala, M

    2010-09-01

    Boreal forests emit large amounts of volatile organic compounds (VOCs) which react with the hydroxyl radical (OH) to influence regional ozone levels and form secondary organic aerosol. Using OH reactivity measurements within a boreal forest in Finland, we investigated the budget of reactive VOCs. OH reactivity was measured using the comparative reactivity method, whereas 30 individual VOCs were measured using proton transfer reaction mass spectrometry, thermal-desorption gas chromatography mass spectrometry, and liquid chromatography mass spectrometry, in August 2008. The measured OH reactivity ranged from below detection limit (3.5 s(-1)), to approximately 60 s(-1) in a single pollution event. The average OH reactivity was approximately 9 s(-1) and no diel variation was observed in the profiles. The measured OH sinks (approximately 30 species) accounted for only 50% of the total measured OH reactivity, implying unknown reactive VOCs within the forest. The five highest measured OH sinks were: monoterpenes (1 s(-1)), CO (0.7 s(-1)), isoprene (0.5 s(-1)), propanal and acetone (0.3 s(-1)), and methane (0.3 s(-1)). We suggest that models be constrained by direct OH reactivity measurements to accurately assess the impact of boreal forest emissions on regional atmospheric chemistry and climate. PMID:20687598

  11. Width of a ferrofluid finger: hysteresis and a double energy minimum.

    PubMed

    Hillier, Narelle J; Jackson, David P

    2007-03-01

    We study a ferrofluid in a horizontal Hele-Shaw geometry subjected to a vertical magnetic field. Specifically, we calculate the energy of a single ferrofluid finger using an idealized model for the finger. By minimizing this energy, we find the preferred finger width as a function of the applied field. Our model predicts a first order transition as the fluid abruptly transforms from a circular drop to a finite finger. This behavior arises because of a double energy minimum that yields two different stable configurations for the system. Interestingly, this system exhibits hysteresis as the circle-to-finger (increasing field) transition occurs at a different applied field than the finger-to-circle (decreasing field) transition. We carry out a simple experiment and observe good overall agreement with the theoretical predictions. PMID:17500798

  12. New Species of Fire Discovered: Fingering Flamelets Form a Dynamic Population

    NASA Technical Reports Server (NTRS)

    Olson, Sandra L.; Miller, Fletcher J.; Wichman, Indrek S.

    2005-01-01

    Poets and artists have long used fire as a metaphor for life. At the NASA Glenn Research Center, recent experiments in a subcritical Rayleigh number flow channel demonstrated that this analogy holds up surprisingly well when tools developed to characterize a biological population are applied to a class of fire that occurs in near-extinction, weakly convective environments (such as microgravity) or in vertically confined spaces (such as our apparatus). Under these conditions, the flame breaks into numerous 'flamelets" that form a Turing-type reaction-diffusion fingering pattern as they spread across the fuel. It is standard practice on U.S. spacecraft for the astronaut crew to turn off the ventilation to help extinguish a fire, both to eliminate the fresh oxygen supply and to reduce the distribution of the smoke. When crew members think that the fire is fully extinguished, they reactivate the ventilation system to clear the smoke. However, some flamelets can survive, and our experiments have demonstrated that flamelets quickly grow into a large fire when ventilation increases.

  13. Epigenetic regulation of puberty via Zinc finger protein-mediated transcriptional repression

    PubMed Central

    Lomniczi, Alejandro; Wright, Hollis; Castellano, Juan Manuel; Matagne, Valerie; Toro, Carlos A.; Ramaswamy, Suresh; Plant, Tony M.; Ojeda, Sergio R.

    2015-01-01

    In primates, puberty is unleashed by increased GnRH release from the hypothalamus following an interval of juvenile quiescence. GWAS implicates Zinc finger (ZNF) genes in timing human puberty. Here we show that hypothalamic expression of several ZNFs decreased in agonadal male monkeys in association with the pubertal reactivation of gonadotropin secretion. Expression of two of these ZNFs, GATAD1 and ZNF573, also decreases in peripubertal female monkeys. However, only GATAD1 abundance increases when gonadotropin secretion is suppressed during late infancy. Targeted delivery of GATAD1 or ZNF573 to the rat hypothalamus delays puberty by impairing the transition of a transcriptional network from an immature repressive epigenetic configuration to one of activation. GATAD1 represses transcription of two key puberty-related genes, KISS1 and TAC3, directly, and reduces the activating histone mark H3K4me2 at each promoter via recruitment of histone demethylase KDM1A. We conclude that GATAD1 epitomizes a subset of ZNFs involved in epigenetic repression of primate puberty. PMID:26671628

  14. Editing T cell specificity towards leukemia by zinc-finger nucleases and lentiviral gene transfer

    PubMed Central

    Lombardo, Angelo; Magnani, Zulma; Liu, Pei-Qi; Reik, Andreas; Chu, Victoria; Paschon, David E.; Zhang, Lei; Kuball, Jurgen; Camisa, Barbara; Bondanza, Attilio; Casorati, Giulia; Ponzoni, Maurilio; Ciceri, Fabio; Bordignon, Claudio; Greenberg, Philip D.; Holmes, Michael C.; Gregory, Philip D.; Naldini, Luigi; Bonini, Chiara

    2016-01-01

    The transfer of high-avidity T-cell receptor (TCR) genes isolated from rare tumor-specific lymphocytes into polyclonal T cells is an attractive cancer immunotherapy strategy. However, TCR gene transfer results in competition for surface expression and inappropriate pairing between the exogenous and endogenous TCR chains, resulting in suboptimal activity and potentially harmful unpredicted specificities. We designed zinc-finger nucleases (ZFNs) promoting the disruption of endogenous TCR β and α chain genes. ZFN-treated lymphocytes lacked CD3/TCR surface expression and expanded with IL-7 and IL-15. Upon lentiviral transfer of a TCR for the WT1 tumor antigen, these TCR-edited cells expressed the new TCR at high levels, were easily expanded to near-purity, and proved superior in specific antigen recognition to matched TCR-transferred cells. In contrast to TCR-transferred cells, TCR edited lymphocytes did not mediate off-target reactivity while maintaining anti-tumor activity in vivo, thus demonstrating that complete editing of T-cell specificity generate tumor-specific lymphocytes with improved biosafety profile. PMID:22466705

  15. Somatosensory evoked potentials following proprioceptive stimulation of finger in man.

    PubMed

    Mima, T; Terada, K; Maekawa, M; Nagamine, T; Ikeda, A; Shibasaki, H

    1996-09-01

    Brisk passive flexion of the proximal interphalangeal joint of the middle finger, produced by using a newly devised instrument, elicited evoked potentials on the scalp. The present study carefully excluded the possible contribution of sensory modalities other than proprioception. The initial part of cortical response was a positive deflexion at the contralateral central area (P1 at 34.6 ms after the stimulus). This was followed by a midfrontal negative wave (N1 at 44.8 ms) and a clear positivity at the contralateral centroparietal area (P2 at 48.0 ms). The evoked responses persisted in spite of the abolition of cutaneous and joint afferents of the finger caused by ischemic anesthesia, but they were lost by ischemic anesthesia of the forearm. Thus, the cortical evoked responses obtained in this study most probably reflect muscle afferent inputs. The scalp distribution of P1 suggested that its cortical generator source was different from that of the N20-P20 components of evoked potentials to electrical median nerve stimulation. Brodmann areas 2 and 3a of human brain, which are known to receive deep receptor inputs, are the most plausible generator sites for the early components of the proprioception-related evoked responses. The amplitude of P2 was related to the velocity but not to the magnitude of movement. In conclusion, the present study established a method for recording the evoked responses to the brisk passive movement of the finger joint, which mainly reflect the dynamic aspects of proprioception mediated through muscle afferent. PMID:8891653

  16. Optical Myography: Detecting Finger Movements by Looking at the Forearm.

    PubMed

    Nissler, Christian; Mouriki, Nikoleta; Castellini, Claudio

    2016-01-01

    One of the crucial problems found in the scientific community of assistive/rehabilitation robotics nowadays is that of automatically detecting what a disabled subject (for instance, a hand amputee) wants to do, exactly when she wants to do it, and strictly for the time she wants to do it. This problem, commonly called "intent detection," has traditionally been tackled using surface electromyography, a technique which suffers from a number of drawbacks, including the changes in the signal induced by sweat and muscle fatigue. With the advent of realistic, physically plausible augmented- and virtual-reality environments for rehabilitation, this approach does not suffice anymore. In this paper, we explore a novel method to solve the problem, which we call Optical Myography (OMG). The idea is to visually inspect the human forearm (or stump) to reconstruct what fingers are moving and to what extent. In a psychophysical experiment involving ten intact subjects, we used visual fiducial markers (AprilTags) and a standard web camera to visualize the deformations of the surface of the forearm, which then were mapped to the intended finger motions. As ground truth, a visual stimulus was used, avoiding the need for finger sensors (force/position sensors, datagloves, etc.). Two machine-learning approaches, a linear and a non-linear one, were comparatively tested in settings of increasing realism. The results indicate an average error in the range of 0.05-0.22 (root mean square error normalized over the signal range), in line with similar results obtained with more mature techniques such as electromyography. If further successfully tested in the large, this approach could lead to vision-based intent detection of amputees, with the main application of letting such disabled persons dexterously and reliably interact in an augmented-/virtual-reality setup. PMID:27148039

  17. Finger coordination during moment production on a mechanically fixed object

    PubMed Central

    Shim, Jae Kun; Latash, Mark L.

    2010-01-01

    The moment production by several fingers on a mechanically fixed vertically oriented handle was studied under the systematic variations of task parameters such as (a) moment magnitude (1.0 Nm and 2.0 Nm) and (b) direction of moment production (into pronation and supination), as well as (c) vertical position of the handle from the moment axis, P (0, 2.0, 4.0, and 6.0 cm in both directions). The purpose of this study was twofold: to investigate the dependences between the task parameters and the performance variables and to test the mechanical advantage hypothesis. The performance variables changed symmetrically with P. In particular, magnitudes of the net horizontal and vertical forces both showed an S-shape change. The position of the point of zero free moment (PZFM) was determined. In the intermediate grasp locations (when 0

    fingers, the ratio of finger force to its moment arm was not constant. The mechanical advantage hypothesis was successful in explaining some of the data but could not cope with other findings. We assume, therefore, that this hypothesis is limited in its applicability and may be task and effector specific. PMID:15024540

  18. Inspiration-induced vascular responses in finger dorsum skin.

    PubMed

    Mayrovitz, Harvey N; Groseclose, Edye E

    2002-03-01

    A rapid and deep inspiration triggers a sympathetically mediated transient vasoconstriction of skin arterioles (inspiratory gasp vascular response, IGVR). Because the IGVR has been most often measured and studied in skin that is rich in arteriovenous anastomoses (AVAs), such as the palmar aspect of the distal phalanx or plantar aspect of the toes, there is little information on its features in skin areas not dominated by thermoregulatory AVAs. Thus, the dependence of the magnitude of the IGVR on AVAs is unclear. We reasoned that if responses in a region of low AVA density, such as the finger dorsum distal phalanx, were comparable to those in AVA-rich skin, this would clarify the issue. Further, it might then be possible to use such areas to provide a useful complementary target for future study of sympathetically induced vasoconstriction. To test this, we determined the features of the finger dorsum IGVR in 28 healthy volunteers (age 19-57 years, 14 males) in whom distal phalanx skin blood perfusion (SBF) was monitored by laser-Doppler during 21 sequential IGVRs, each separated by 2 min. IGVR was quantified as the minimum SBF during each IGVR, expressed as a percentage of each immediately preceding 2-min SBF average. Results (mean +/- SD) revealed an overall IGVR of 72.2 +/- 16.7%, which is very near that reported from studies on the AVA-rich palmar finger pad. We therefore conclude that the IGVR does not depend on the presence of AVAs and that the dorsal distal phalanx is a viable alternative for the study of sympathetically related neurovascular responses. PMID:11866546

  19. Optical Myography: Detecting Finger Movements by Looking at the Forearm

    PubMed Central

    Nissler, Christian; Mouriki, Nikoleta; Castellini, Claudio

    2016-01-01

    One of the crucial problems found in the scientific community of assistive/rehabilitation robotics nowadays is that of automatically detecting what a disabled subject (for instance, a hand amputee) wants to do, exactly when she wants to do it, and strictly for the time she wants to do it. This problem, commonly called “intent detection,” has traditionally been tackled using surface electromyography, a technique which suffers from a number of drawbacks, including the changes in the signal induced by sweat and muscle fatigue. With the advent of realistic, physically plausible augmented- and virtual-reality environments for rehabilitation, this approach does not suffice anymore. In this paper, we explore a novel method to solve the problem, which we call Optical Myography (OMG). The idea is to visually inspect the human forearm (or stump) to reconstruct what fingers are moving and to what extent. In a psychophysical experiment involving ten intact subjects, we used visual fiducial markers (AprilTags) and a standard web camera to visualize the deformations of the surface of the forearm, which then were mapped to the intended finger motions. As ground truth, a visual stimulus was used, avoiding the need for finger sensors (force/position sensors, datagloves, etc.). Two machine-learning approaches, a linear and a non-linear one, were comparatively tested in settings of increasing realism. The results indicate an average error in the range of 0.05–0.22 (root mean square error normalized over the signal range), in line with similar results obtained with more mature techniques such as electromyography. If further successfully tested in the large, this approach could lead to vision-based intent detection of amputees, with the main application of letting such disabled persons dexterously and reliably interact in an augmented-/virtual-reality setup. PMID:27148039

  20. Reactivity of dicoordinated stannylones (Sn0) versus stannylenes (SnII): an investigation using DFT-based reactivity indices.

    PubMed

    Broeckaert, Lies; Frenking, Gernot; Geerlings, Paul; De Proft, Frank

    2013-10-01

    The reactivity of dicoordinated Sn(0) compounds, stannylones, is probed using density functional theory (DFT)-based reactivity indices and compared with the reactivity of dicoordinated Sn(II) compounds, stannylenes. For the former compounds, the influence of different types of electron-donating ligands, such as cyclic and acyclic carbenes, stannylenes and phosphines, on the reactivity of the central Sn atom is analyzed in detail. Sn(0) compounds are found to be relatively soft systems with a high nucleophilicity, and the plots of the Fukui function f(-) for an electrophilic attack consistently predict the highest reactivity on the Sn atom. Next, complexes of dicoordinated Sn compounds with different Lewis acids of variable hardness are computed. In a first part, the double-base character of stannylones is demonstrated in interactions with the hardest Lewis acid H(+). Both the first and second proton affinities (PAs) are high and are well correlated with the atomic charge on the Sn atom, probing its local hardness. These observations are also in line with electrostatic potential plots that demonstrate that the tin atom in Sn(0) compounds bears a higher negative charge in comparison to Sn(II) compounds. Stannylones and stannylenes can be distinguished from each other by the partial charges at Sn and by various reactivity indices. It also becomes clear that there is a smooth transition between the two classes of compounds. We furthermore demonstrate both from DFT-based reactivity indices and from energy decomposition analysis, combined with natural orbitals for chemical valence (EDA-NOCV), that the monocomplexed stannylones are still nucleophilic and as reactive towards a second Lewis acid as towards the first one. The dominating interaction is a strong σ-type interaction from the Sn atom towards the Lewis acid. The interaction energy is higher for complexes with the cation Ag(+) than with the non-charged electrophiles BH(3), BF(3), and AlCl(3). PMID:23946256